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Kovacevic A, Smith DRM, Rahbé E, Novelli S, Henriot P, Varon E, Cohen R, Levy C, Temime L, Opatowski L. Exploring factors shaping antibiotic resistance patterns in Streptococcus pneumoniae during the 2020 COVID-19 pandemic. eLife 2024; 13:e85701. [PMID: 38451256 PMCID: PMC10923560 DOI: 10.7554/elife.85701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/12/2024] [Indexed: 03/08/2024] Open
Abstract
Non-pharmaceutical interventions implemented to block SARS-CoV-2 transmission in early 2020 led to global reductions in the incidence of invasive pneumococcal disease (IPD). By contrast, most European countries reported an increase in antibiotic resistance among invasive Streptococcus pneumoniae isolates from 2019 to 2020, while an increasing number of studies reported stable pneumococcal carriage prevalence over the same period. To disentangle the impacts of the COVID-19 pandemic on pneumococcal epidemiology in the community setting, we propose a mathematical model formalizing simultaneous transmission of SARS-CoV-2 and antibiotic-sensitive and -resistant strains of S. pneumoniae. To test hypotheses underlying these trends five mechanisms were built into the model and examined: (1) a population-wide reduction of antibiotic prescriptions in the community, (2) lockdown effect on pneumococcal transmission, (3) a reduced risk of developing an IPD due to the absence of common respiratory viruses, (4) community azithromycin use in COVID-19 infected individuals, (5) and a longer carriage duration of antibiotic-resistant pneumococcal strains. Among 31 possible pandemic scenarios involving mechanisms individually or in combination, model simulations surprisingly identified only two scenarios that reproduced the reported trends in the general population. They included factors (1), (3), and (4). These scenarios replicated a nearly 50% reduction in annual IPD, and an increase in antibiotic resistance from 20% to 22%, all while maintaining a relatively stable pneumococcal carriage. Exploring further, higher SARS-CoV-2 R0 values and synergistic within-host virus-bacteria interaction mechanisms could have additionally contributed to the observed antibiotic resistance increase. Our work demonstrates the utility of the mathematical modeling approach in unraveling the complex effects of the COVID-19 pandemic responses on AMR dynamics.
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Affiliation(s)
- Aleksandra Kovacevic
- Institut Pasteur, Université Paris Cité, Epidemiology and Modelling of Antibiotic Evasion (EMAE) unitParisFrance
- Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Inserm U1018, CESP, Anti-infective evasion and pharmacoepidemiology teamMontigny-Le-BretonneuxFrance
| | - David RM Smith
- Institut Pasteur, Université Paris Cité, Epidemiology and Modelling of Antibiotic Evasion (EMAE) unitParisFrance
- Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Inserm U1018, CESP, Anti-infective evasion and pharmacoepidemiology teamMontigny-Le-BretonneuxFrance
- Modélisation, épidémiologie et surveillance des risques sanitaires (MESuRS), Conservatoire national des arts et métiersParisFrance
- Health Economics Research Centre, Nuffield Department of Health, University of OxfordOxfordUnited Kingdom
| | - Eve Rahbé
- Institut Pasteur, Université Paris Cité, Epidemiology and Modelling of Antibiotic Evasion (EMAE) unitParisFrance
- Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Inserm U1018, CESP, Anti-infective evasion and pharmacoepidemiology teamMontigny-Le-BretonneuxFrance
| | - Sophie Novelli
- Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Inserm U1018, CESP, Anti-infective evasion and pharmacoepidemiology teamMontigny-Le-BretonneuxFrance
| | - Paul Henriot
- Modélisation, épidémiologie et surveillance des risques sanitaires (MESuRS), Conservatoire national des arts et métiersParisFrance
- PACRI unit, Institut Pasteur, Conservatoire national des arts et métiersParisFrance
| | - Emmanuelle Varon
- Centre National de Référence des Pneumocoques, Centre Hospitalier Intercommunal de CréteilCréteilFrance
| | - Robert Cohen
- Institut Mondor de Recherche Biomédicale-Groupe de Recherche Clinique Groupe d’Etude des Maladies Infectieuses Néonatales et Infantiles (IMRB-GRC GEMINI), Université Paris Est, 94000CréteilFrance
- Groupe de Pathologie Infectieuse Pédiatrique (GPIP), 06200NiceFrance
- Unité Court Séjour, Petits Nourrissons, Service de Néonatologie, Centre Hospitalier, Intercommunal de CréteilCréteilFrance
- Association Clinique et Thérapeutique Infantile du Val-de-Marne (ACTIV), 94000CréteilFrance
- Association Française de Pédiatrie Ambulatoire (AFPA), 45000OrléansFrance
| | - Corinne Levy
- Institut Mondor de Recherche Biomédicale-Groupe de Recherche Clinique Groupe d’Etude des Maladies Infectieuses Néonatales et Infantiles (IMRB-GRC GEMINI), Université Paris Est, 94000CréteilFrance
- Groupe de Pathologie Infectieuse Pédiatrique (GPIP), 06200NiceFrance
- Association Clinique et Thérapeutique Infantile du Val-de-Marne (ACTIV), 94000CréteilFrance
- Association Française de Pédiatrie Ambulatoire (AFPA), 45000OrléansFrance
| | - Laura Temime
- Modélisation, épidémiologie et surveillance des risques sanitaires (MESuRS), Conservatoire national des arts et métiersParisFrance
- PACRI unit, Institut Pasteur, Conservatoire national des arts et métiersParisFrance
| | - Lulla Opatowski
- Institut Pasteur, Université Paris Cité, Epidemiology and Modelling of Antibiotic Evasion (EMAE) unitParisFrance
- Université Paris-Saclay, Université de Versailles Saint-Quentin-en-Yvelines, Inserm U1018, CESP, Anti-infective evasion and pharmacoepidemiology teamMontigny-Le-BretonneuxFrance
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Santiago NA, He B, Howard SL, Beaudin S, Strupp BJ, Smith DR. Developmental Manganese Exposure Causes Lasting Attention Deficits Accompanied by Dysregulation of mTOR Signaling and Catecholaminergic Gene Expression in Brain Prefrontal Cortex. bioRxiv 2023:2023.07.16.549215. [PMID: 37503220 PMCID: PMC10370122 DOI: 10.1101/2023.07.16.549215] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Elevated manganese (Mn) exposure is associated with attentional deficits in children, and is an environmental risk factor for attention deficit hyperactivity disorder (ADHD). We have shown that developmental Mn exposure causes lasting attention and sensorimotor deficits in a rat model of early childhood Mn exposure, and that these deficits are associated with a hypofunctioning catecholaminergic system in the prefrontal cortex (PFC), though the mechanistic basis for these deficits is not well understood. To address this, male Long-Evans rats were exposed orally to Mn (50 mg/kg/d) over PND 1-21 and attentional function was assessed in adulthood using the 5-Choice Serial Reaction Time Task. Targeted catecholaminergic system and epigenetic gene expression, followed by unbiased differential DNA methylation and gene regulation expression transcriptomics in the PFC, were performed in young adult littermates. Results show that developmental Mn exposure causes lasting focused attention deficits that are associated with reduced gene expression of tyrosine hydroxylase, dopamine transporter, and DNA methyltransferase 3a. Further, developmental Mn exposure causes broader lasting methylation and gene expression dysregulation associated with epigenetic regulation, inflammation, cell development, and hypofunctioning catecholaminergic neuronal systems. Pathway enrichment analyses uncovered mTOR and Wnt signaling pathway genes as significant transcriptomic regulators of the Mn altered transcriptome, and Western blot of total, C1 and C2 phospho-mTOR confirmed mTOR pathway dysregulation. Our findings deepen our understanding of the mechanistic basis of how developmental Mn exposure leads to lasting catecholaminergic dysfunction and attention deficits, which may aid future therapeutic interventions of environmental exposure associated disorders. Significance Statement Attention deficit hyperactivity disorder (ADHD) is associated with environmental risk factors, including exposure to neurotoxic agents. Here we used a rodent model of developmental manganese (Mn) exposure producing lasting attention deficits to show broad epigenetic and gene expression changes in the prefrontal cortex, and to identify disrupted mTOR and Wnt signaling pathways as a novel mechanism for how developmental Mn exposure may induce lasting attention and catecholaminergic system impairments. Importantly, our findings establish early development as a critical period of susceptibility to lasting deficits in attentional function caused by elevated environmental toxicant exposure. Given that environmental health threats disproportionately impact communities of color and low socioeconomic status, our findings can aid future studies to assess therapeutic interventions for vulnerable populations.
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Welikhe P, Williams MR, King K, Bos J, Akland M, Baffaut C, Beck EG, Bierer A, Bosch DD, Brooks ES, Buda AR, Cavigelli M, Faulkner J, Feyereisen GW, Fortuna A, Gamble J, Hanrahan BR, Hussain MZ, Kovar JL, Lee B, Leytem AB, Liebig MA, Line D, Macrae ML, Moorman TB, Moriasi D, Mumbi R, Nelson N, Ortega-Pieck A, Osmond D, Penn C, Pisani O, Reba ML, Smith DR, Unrine J, Webb P, White KE, Wilson H, Witthaus LM. Uncertainty in phosphorus fluxes and budgets across the U.S. long-term agroecosystem research network. J Environ Qual 2023. [PMID: 37145888 DOI: 10.1002/jeq2.20485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/28/2023] [Accepted: 04/21/2023] [Indexed: 05/07/2023]
Abstract
Phosphorus (P) budgets can be useful tools for understanding nutrient cycling and quantifying the effectiveness of nutrient management planning and policies; however, uncertainties in agricultural nutrient budgets are not often quantitatively assessed. The objective of this study was to evaluate uncertainty in P fluxes (fertilizer/manure application, atmospheric deposition, irrigation, crop removal, surface runoff, leachate) and the propagation of these uncertainties to annual P budgets. Data from 56 cropping systems in the P-FLUX database, which spans diverse rotations and landscapes across the U.S. and Canada, were evaluated. Results showed that across cropping systems, average annual P budget was 22.4 kg P ha-1 (range = -32.7 to 340.6 kg P ha-1 ), with an average uncertainty of 13.1 kg P ha-1 (range = 1.0 to 87.1 kg P ha-1 ). Fertilizer/manure application and crop removal were the largest P fluxes across cropping systems and, as a result, accounted for the largest fraction of uncertainty in annual budgets (61 and 37%, respectively). Remaining fluxes individually accounted for <2% of the budget uncertainty. Uncertainties were large enough that determining whether P was increasing, decreasing, or not changing was inconclusive in 39% of the budgets evaluated. Findings indicate that more careful and/or direct measurements of inputs, outputs, and stocks are needed. Recommendations for minimizing uncertainty in P budgets based on the results of the study were developed. Quantifying, communicating, and constraining uncertainty in budgets among production systems and multiple geographies is critical for engaging stakeholders, developing local and national strategies for P reduction, and informing policy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- P Welikhe
- Department of Agronomy, Purdue University
- National Soil Erosion Research Laboratory, USDA-ARS
| | - M R Williams
- National Soil Erosion Research Laboratory, USDA-ARS
| | - K King
- Soil Drainage Research Unit, USDA-ARS
| | - J Bos
- National Soil Erosion Research Laboratory, USDA-ARS
| | - M Akland
- Department of Plant and Soil Sciences, University of Kentucky
| | - C Baffaut
- Cropping Systems and Water Quality Research Unit, USDA-ARS
| | | | - A Bierer
- Northwest Irrigation and Soils Research Lab, USDA-ARS
| | - D D Bosch
- Southeast Watershed Research Laboratory, USDA-ARS
| | - E S Brooks
- Department of Soil and Water Resources, University of Idaho
| | - A R Buda
- Pasture Systems and Watershed Management Research Unit, USDA-ARS
| | - M Cavigelli
- Sustainable Agricultural Systems Lab, USDA-ARS
| | - J Faulkner
- Department of Plant and Soil Science, University of Vermont
| | | | - A Fortuna
- Grazinglands Research Laboratory, USDA-ARS
| | - J Gamble
- Plant Science Research Unit, USDA-ARS
| | | | - M Z Hussain
- W.K. Kellogg Biological Station, Michigan State University
| | - J L Kovar
- National Laboratory for Agriculture and the Environment, USDA-ARS
| | - B Lee
- Department of Plant and Soil Sciences, University of Kentucky
| | - A B Leytem
- Northwest Irrigation and Soils Research Lab, USDA-ARS
| | - M A Liebig
- Northern Great Plains Research Laboratory, USDA-ARS
| | - D Line
- Department of Crop and Soil Sciences, North Carolina State University
| | - M L Macrae
- Department of Geography and Environmental Management, University of Waterloo
| | - T B Moorman
- National Laboratory for Agriculture and the Environment, USDA-ARS
| | - D Moriasi
- Grazinglands Research Laboratory, USDA-ARS
| | - R Mumbi
- Department of Agronomy, Purdue University
- National Soil Erosion Research Laboratory, USDA-ARS
| | - N Nelson
- Department of Agronomy, Kansas State University
| | - A Ortega-Pieck
- Department of Soil and Water Resources, University of Idaho
| | - D Osmond
- Department of Crop and Soil Sciences, North Carolina State University
| | - C Penn
- National Soil Erosion Research Laboratory, USDA-ARS
| | - O Pisani
- Southeast Watershed Research Laboratory, USDA-ARS
| | - M L Reba
- Delta Water Management Research Unit, USDA-ARS
| | - D R Smith
- Grassland, Soil and Water Research Laboratory, USDA-ARS
| | - J Unrine
- Department of Plant and Soil Sciences, University of Kentucky
- Kentucky Water Resources Research Institute
| | - P Webb
- Department of Crop, Soil, and Environmental Sciences, University of Arkansas
| | - K E White
- Sustainable Agricultural Systems Lab, USDA-ARS
| | - H Wilson
- Agriculture and Agri-Food Canada, Science and Technology Branch, Brandon Research and Development Centre
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Morrill JC, Peters CJ, Bettinger GE, Palermo PM, Smith DR, Watts DM. Rift Valley fever MP-12 vaccine elicits an early protective immune response in mice. Vaccine 2022; 40:7255-7261. [PMID: 36333222 DOI: 10.1016/j.vaccine.2022.10.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022]
Abstract
Rift Valley fever virus (RVFV) is an important mosquito-borne pathogen that causes outbreaks of severe disease in people and livestock throughout Africa and the Arabian Peninsula. The development of an effective veterinary and human vaccine to protect against Rift Valley fever (RVF) disease remains a high priority. The live attenuated RVFV MP-12 is a promising vaccine candidate for the prevention of RVF in both human and domestic ruminants. The aim of this study was to determine the onset of protective immunity elicted in mice by a single dose of this vaccine. Groups of CD-1 mice were vaccinated intraperitoneally with RVFV MP-12 vaccine and challenged on days 2, 5, 6 and 7 post-vaccination (PV) with a lethal dose of virulent RVFV. The mice were observed once daily for terminal morbidity and blood samples were obtained from the retro-orbital sinus complex on days 23 and 28 PV of surviving mice to determine RVFV neutralizing antibody titers. In one test, 2 of 3 mice challenged on day 2 PV survived and all 3 mice challenged at days 5 and 7 PV also survived. A second test of 10 mice per group was performed, and half (5) of those challenged at day 2 PV survived while all (10) survived challenge at day 4 and 6 PV. All surviving animals develop antibody that ranged from 1:80 to 1:1,280 PV. In a separate experiment, RVFV MP-12 vaccinated CD-1 mice, but not challenged developed a low viremia for the first 3 days PV and neutralzing antibody was detected on days 5 through day 28 PV. These findings demonstrated that the RVFV MP-12 vaccine elicited a rapid protective immune response in mice as early as 2 days PV, thus further supporting the effectiveness of this vaccine candidate for preventing RVF among humans and domestic ruminants.
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Affiliation(s)
- J C Morrill
- Departmentof Microbiology and Immunology, University of Texas Medical Branch at Galveston, TX 77555, United States.
| | - C J Peters
- Departments of Microbiology & Immunology and Pathology, University of Texas Medical Branch at Galveston, TX 77555, United States.
| | - G E Bettinger
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States
| | - P M Palermo
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States.
| | - D R Smith
- Department of Microbiology and Immunology, Naval Medical Research Center, Biological Defense Research Directorate, Fort Detrick, MD 21702, United States.
| | - D M Watts
- Dept. of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States.
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5
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Major MR, McKee GR, Geiger B, Hartog DJD, Jaehnig K, Seyfert C, Smith DR, Stewart SD, Yan Z. Pedestal fluctuation measurements with charge exchange imaging at the DIII-D tokamak. Rev Sci Instrum 2022; 93:113503. [PMID: 36461537 DOI: 10.1063/5.0101844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/20/2022] [Indexed: 06/17/2023]
Abstract
A new high radial resolution 2D multichannel Charge eXchange Imaging (CXI) diagnostic is under development for deployment at DIII-D. The diagnostic system will measure low-to-intermediate radial wavenumber carbon density fluctuations by observing the n = 8 - 7 (λ = 529.06 nm) C-VI emission line, resulting from charge exchange collisions between heating neutral beam atoms and the intrinsic carbon ion density. The new CXI diagnostic will provide measurements with ΔR ∼ 0.4 cm to access higher kr instabilities (kr < 8 cm-1) predicted to arise in the steep-gradient region of the H-mode pedestal. The CXI system will feature 60 fiber bundles in a 12 × 5 arrangement, with each bundle consisting of four 1 mm fibers. A custom optical system has been designed to filter and image incoming signals onto an 8 × 8 avalanche photodiode array. Additionally, a novel electronics suite has been designed and commissioned to amplify and digitize the relatively low-intensity carbon signal at a 2 MHz bandwidth. Forward modeling results of the active C-VI emission suggest sufficient signal to noise ratios to resolve turbulent fluctuations. Prototype measurements demonstrate the ability to perform high frequency pedestal measurements.
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Affiliation(s)
- M R Major
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - G R McKee
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - B Geiger
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - D J Den Hartog
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - K Jaehnig
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - C Seyfert
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - D R Smith
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - S D Stewart
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
| | - Z Yan
- University of Wisconsin-Madison, Madison, Wisconsin 53707, USA
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6
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Offiah C, Tierney S, Egan B, Collins DR, Ryan DJ, McCarthy AJ, Smith DR, Boyle E, Delaney H, McCabe DJH. 202 Frequency of inter-specialty consensus decisions and adherence to advice following a weekly neurovascular multidisciplinary meeting. J Neurol Psychiatry 2022. [DOI: 10.1136/jnnp-2022-abn2.246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background/AimsData are limited on the frequency of ‘consensus’ between sub-specialists attending a neurovascular multidisciplinary meeting (MDM) regarding management of patients with extracranial carotid/vertebral stenoses, and post-MDM ‘adherence’ to advice. This prospective audit/quality improve- ment project collated data at a Neurovascular/Stroke Centre.MethodsData from a weekly MDM were prospectively-recorded to document the proportion of extrac- ranial carotid/vertebral stenosis patients in whom ‘consensus management decisions’ were reached by Neurologists/Vascular Surgeons/Stroke Physicians-Geriatricians. Adherence to MDM advice was analysed in patients with asymptomatic, symptomatic and ‘indeterminate symptomatic status [ISS]’ stenoses, including intervals between symptom onset-MDM discussion +/- intervention.Results115 patients were discussed (September/2017-February/2020). Consensus regarding manage- ment was 96.5% (111/115) overall; 100% (29/29) with asymptomatic carotid stenosis [ACS], 96.5% (55/57) with symptomatic carotid stenosis [SCS], and 93.1% (27/29) with ISS. Overall adherence to MDM advice was 93% (107/115); 100% (29/29) with ACS, 89.5% (51/57) with SCS, 93.1% (27/29) with ISS. Median interval from index TIA/stroke to intervention was 12.5 days (IQR:9-18d), and MDM discussion-to-intervention was 5.5d (IQR:1-7d) in patients with 50-99% SCS.ConclusionsHigh-frequency inter-specialty consensus regarding management/adherence to proposed treatment supports a collaborative, multidisciplinary model-of-care in patients with extracranial arterial stenosis. Service development should shorten intervals between symptoms-MDT discussion-intervention to optimise secondary prevention.
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Smith DR, McKee G, Den Hartog D, Geiger B, Grulke O, Han X, Jaehnig K, Seyfert C, Windisch T. Conceptual design and performance predictions for 2D beam emission spectroscopy turbulence measurements at Wendelstein 7-X. Rev Sci Instrum 2022; 93:073506. [PMID: 35922327 DOI: 10.1063/5.0101355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
A conceptual design for a 2D beam emission spectroscopy diagnostic system to measure ion gyro-scale plasma turbulence at Wendeslstein 7-X is described. The conceptual design identifies field-aligned viewing geometries and ports for cross-field turbulence measurements in the neutral beam volume. A 2D sightline grid covers the outer plasma region, and the grid configuration provides sufficient k-space coverage in radial and poloidal directions for ion temperature gradient and trapped-electron mode turbulence measurements. Emission intensity estimates, optical transmission losses, and detector noise levels indicate that the measurements will be sensitive to plasma density fluctuations as small as δn/n ≈ 0.5% with a bandwidth of 1 MHz. Implementation challenges include a small beam emission Doppler shift due to nearly radial heating beams and reduced optical throughput due to collection aperture limitations.
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Affiliation(s)
- D R Smith
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - G McKee
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - D Den Hartog
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - B Geiger
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - O Grulke
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - X Han
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - K Jaehnig
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C Seyfert
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - T Windisch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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8
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Lim ST, Tobin WO, Murphy S, Kinsella JA, Smith DR, Lim SY, Murphy SM, Coughlan T, Collins DR, O'Neill D, Egan B, Tierney S, McCabe D. Profile of reticulated platelets in the early, subacute and late phases after transient ischemic attack or ischemic stroke. Platelets 2020; 33:89-97. [PMID: 33347340 DOI: 10.1080/09537104.2020.1850670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Information regarding the profile of reticulated platelets (RP) in ischemic cerebrovascular disease (CVD) patients is limited. Data from two prospective, observational, case-control studies were combined to compare the %RP using whole blood flow cytometry in patients ≤ 4 weeks of TIA/stroke onset (baseline, N = 210), and 14 ±7 days (14d, N = 182) and ≥ 90 days (90d, N = 145) after starting or changing antiplatelet therapy with healthy controls (N = 34). There were no differences in median %RP between the overall CVD patient population at baseline or 14d vs. controls (P ≥ 0.2). However, the median %RP was significantly higher in CVD patients overall at 90d (P = .036), and in the subgroup of patients with "lacunar" TIA/ischemic stroke at baseline (P = .04) and at 90d (P = .01), but not at 14d (P = .06) vs. controls. There were no significant differences in the median %RP between other TIA/stroke subgroups and controls (P ≥ 0.05). Elevated circulating reticulated platelets, as a marker of increased platelet production/turnover, may occur following an ischemic event in a well-phenotyped TIA/ischemic stroke population overall, but may precede symptom onset at least in the subgroup with small vessel occlusion. These data improve our understanding of the profile of reticulated platelets in CVD patients.
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Affiliation(s)
- S T Lim
- Department of Neurology, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Department of Clinical Neurosciences, Royal Free Campus, UCL Queen Square Institute of Neurology, London, UK
| | - W O Tobin
- Department of Neurology, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Sjx Murphy
- Department of Neurology, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - J A Kinsella
- Department of Neurology, St Vincent's University Hospital, University College, Dublin, Ireland
| | - D R Smith
- Department of Neurology, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Vascular Neurology Research Foundation, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - S Y Lim
- Faculty of Health and Medical Sciences, Taylors University School of Medicine, Selangor, Malaysia
| | - S M Murphy
- Department of Neurology, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Academic Unit of Neurology, School of Medicine, Trinity College, Dublin, Ireland
| | - T Coughlan
- Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - D R Collins
- Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - D O'Neill
- Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - B Egan
- Department of Vascular Surgery, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - S Tierney
- Department of Vascular Surgery, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland
| | - Djh McCabe
- Department of Neurology, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Stroke Service, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Department of Clinical Neurosciences, Royal Free Campus, UCL Queen Square Institute of Neurology, London, UK.,Vascular Neurology Research Foundation, The Adelaide and Meath Hospital, Dublin, Incorporating the National Children's Hospital (AMNCH)/Tallaght University Hospital, Dublin, Ireland.,Academic Unit of Neurology, School of Medicine, Trinity College, Dublin, Ireland.,Stroke Clinical Trials Network Ireland, Dublin, Ireland.,Irish Centre for Vascular Biology, Dublin, Ireland
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Peli M, Bostick BC, Barontini S, Placidi D, Giorgino A, Ranzi R, Smith DR, Conversano M, Lucchini RG. Distribution of Manganese-Substituted Magnetites in Dusts from Taranto, Italy. Eur J Public Health 2020. [DOI: 10.1093/eurpub/ckaa166.139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Elevated exposure to manganese (Mn) in environmental dusts and airborne particulates, particular from ferromanganese alloy steel production and metal working, is associated with a number of negative health outcomes, including Parkinsonism and other nervous system diseases. Manganese contamination and exposure from industrial sources is difficult to identify or quantify, as manganese is naturally abundant in the environment, and means to distinctly identify or fingerprint Mn arising from different industrial and environmental sources are limited. Here, the chemical and mineralogical properties of Mn in dusts from an active steel production facility in Taranto, Italy, were compared with those of indoor and outdoor deposited dust samples and surface soils collected in a series of schools in the nearby town. X-ray absorption spectroscopy revealed distinct chemical forms of Mn in industrial sources from those in typical background soils. Manganese ore from the facility contained abundant Mn(III, IV) oxides, while Mn-substituted magnetites were the most abundant mineral phase in dusts found in areas of the plant where metal was produced or combustion occurred. All school dusts were primarily composed of Mn-substituted magnetites, while most of the soils contained abundant manganese(IV) oxides. Source apportionment of Mn in regional dust and soil samples was estimated using linear combination fitting with representative industrial source materials. Manganese in dusts from the Taranto area community adjacent to the plant was derived primarily from industrially-sourced dusts produced during high temperature coke or steel production rather than re-suspended local soils or ore source material. Soils contained smaller proportion of industrially-derived Mn and are distinct from dusts, indicating that soil is a minor contributor of dust Mn in this area.
Key messages
Manganese speciation gives useful information in investigating Mn toxicology to humans in urban areas. Manganese-substituted magnetites may represent the target compound useful to distinguish toxic and non-toxic Mn-containing elements.
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Affiliation(s)
- M Peli
- Department of Civil, Environmental, Architectural Engineering, Università degli Studi di Brescia, Brescia, Italy
| | - B C Bostick
- Lamont-Doherty Earth Observatory, Columbia University, New York, USA
| | - S Barontini
- Department of Civil, Environmental, Architectural Engineering, Università degli Studi di Brescia, Brescia, Italy
| | - D Placidi
- Department of Medical and Surgical Specialties, Radiological, Università degli Studi di Brescia, Brescia, Italy
| | - A Giorgino
- Department of Prevention, Local Health Authority of Taranto, Taranto, Italy
| | - R Ranzi
- Department of Civil, Environmental, Architectural Engineering, Università degli Studi di Brescia, Brescia, Italy
| | - D R Smith
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, USA
| | - M Conversano
- Department of Prevention, Local Health Authority of Taranto, Taranto, Italy
| | - R G Lucchini
- Department of Medical and Surgical Specialties, Radiological, Università degli Studi di Brescia, Brescia, Italy
- Department of Environmental Medicine & Public Health, Icahn School of Medicine at Mount Sinai, New York, USA
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Smith DR, Macrae ML, Kleinman PJA, Jarvie HP, King KW, Bryant RB. The Latitudes, Attitudes, and Platitudes of Watershed Phosphorus Management in North America. J Environ Qual 2019; 48:1176-1190. [PMID: 31589709 DOI: 10.2134/jeq2019.03.0136] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phosphorus (P) plays a crucial role in agriculture as a primary fertilizer nutrient-and as a cause of the eutrophication of surface waters. Despite decades of efforts to keep P on agricultural fields and reduce losses to waterways, frequent algal blooms persist, triggering not only ecological disruption but also economic, social, and political consequences. We investigate historical and persistent factors affecting agricultural P mitigation in a transect of major watersheds across North America: Lake Winnipeg, Lake Erie, the Chesapeake Bay, and Lake Okeechobee/Everglades. These water bodies span 26 degrees of latitude, from the cold climate of central Canada to the subtropics of the southeastern United States. These water bodies and their associated watersheds have tracked trajectories of P mitigation that manifest remarkable similarities, and all have faced challenges in the application of science to agricultural management that continue to this day. An evolution of knowledge and experience in watershed P mitigation calls into question uniform solutions as well as efforts to transfer strategies from other arenas. As a result, there is a need to admit to shortcomings of past approaches, plotting a future for watershed P mitigation that accepts the sometimes two-sided nature of Hennig Brandt's "Devil's Element."
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11
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Mayes DM, Bhatta CP, Shi D, Brown JC, Smith DR. Body Size Influences Stingless Bee (Hymenoptera: Apidae) Communities Across a Range of Deforestation Levels in Rondônia, Brazil. J Insect Sci 2019; 19:5475280. [PMID: 31222324 PMCID: PMC6474196 DOI: 10.1093/jisesa/iez032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Developments in understanding bee responses to habitat loss indicate that body size is a trait with important consequences for conservation. Stingless bees (Hymenoptera, Apidae, Meliponini) are a diverse group of eusocial bees providing pollination services in tropical landscapes, exhibiting a large range in body size across species. We tested the effects of deforestation on the body sizes of stingless bee communities by using museum specimens and revisiting a previous effort that sampled stingless bee communities across varying levels of deforestation at 183 sites in Rondônia, Brazil, in 1996-1997. Body size measurements (intertegular distance) from 72 species collected were included as dependent variables in response to forest area, forest edge, and connectivity of forest patches at several spatial scales. We find that stingless bee body size is negatively related to forest cover: mean community body size was larger in areas with greater amounts of deforestation, and smaller in areas with less deforestation. Second, stingless bee species richness was positively associated with forest edge regardless of body size. Lastly, we find that as forest patch isolation increased, the stingless bee community body size also increased. These findings support hypotheses that small stingless bee species might be more negatively affected by deforestation, adding to the growing body of evidence that stingless bees require areas of intact forest in near proximity to other forest patches to conserve these diverse pollinator communities.
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Affiliation(s)
- D M Mayes
- Department of Ecology & Evolutionary Biology, University of Kansas, Haworth Hall, Lawrence, KS
| | - C P Bhatta
- Department of Ecology & Evolutionary Biology, University of Kansas, Haworth Hall, Lawrence, KS
| | - D Shi
- Department of Geography & Atmospheric Science, University of Kansas, Lawrence, KS
| | - J C Brown
- Department of Geography & Atmospheric Science, University of Kansas, Lawrence, KS
| | - D R Smith
- Department of Ecology & Evolutionary Biology, University of Kansas, Haworth Hall, Lawrence, KS
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12
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Abstract
Background Although stigma and discrimination by nurses against patients infected with human immunodeficiency virus (HIV) or hepatitis C virus (HCV) have been reported, potential determinants of nurses' willingness to care for these patients have not been well studied in Thailand. Aims To identify factors associated with Thai nurses' willingness to care for patients infected with HIV or HCV. Methods Multivariable logistic regression analysis of data from a questionnaire completed by nurses at a large hospital in Bangkok, Thailand. Results Of 626 nurses, 546 (87%) nurses participated. Eleven per cent (59) and 6% (34) had previously experienced HIV- or HCV-infected blood contamination incidents, respectively. Forty-four per cent (240) and 38% (208) reported unwillingness to care for HIV- or HCV-infected patients, respectively. Willingness to care was less common [adjusted odds ratios 0.51 (0.34-0.74) for HIV and 0.62 (0.42-0.89) for HCV] in nurses aged ≥ 40 years and in those who feared HCV [0.63 (0.37-0.99)], but not HIV [0.84 (0.5-1.26)] transmission. Nurses who had confidence in protecting themselves against infection with HIV [1.84 (1.52-2.04)] and HCV [1.87 (1.45-2.18)], and accepting attitudes towards HIV-infected co-workers [1.39 (1.08-1.66)] but not HCV-infected co-workers [1.16 (0.83-1.5)], were more willing to care for HIV- and HCV-infected patients. Conclusions Around 4 in 10 Thai nurses in our sample were unwilling to care for HIV- or HCV-infected patients. Minimizing the risk of nosocomial transmission and improving the public perception of infected individuals may help improve nurses' willingness to care for such patients, in Thailand or elsewhere.
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Affiliation(s)
- T Ishimaru
- Department of Health Management, Nishinihon Occupational Health Service Center, Kitakyushu, Japan
- Department of Occupational Health Practice and Management, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - K Wada
- Bureau of International Health Cooperation, National Center for Global Health and Medicine, Tokyo, Japan
| | - S Arphorn
- Department of Occupational Health and Safety, Faculty of Public Health, Mahidol University, Bangkok, Thail
| | - D R Smith
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
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Iwanowicz LR, Pinkney AE, Guy CP, Major AM, Munney K, Blazer VS, Alvarez DA, Walsh HL, Sperry A, Braham R, Sanders LR, Smith DR. Temporal evaluation of estrogenic endocrine disruption markers in smallmouth bass (Micropterus dolomieu) reveals seasonal variability in intersex. Sci Total Environ 2019; 646:245-256. [PMID: 30055487 DOI: 10.1016/j.scitotenv.2018.07.167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
A reconnaissance project completed in 2009 identified intersex and elevated plasma vitellogenin in male smallmouth bass inhabiting the Missisquoi River, VT. In an attempt to identify the presence and seasonality of putative endocrine disrupting chemicals or other factors associated with these observations, a comprehensive reevaluation was conducted between September 2012 and June 2014. Here, we collected smallmouth bass from three physically partitioned reaches along the river to measure biomarkers of estrogenic endocrine disruption in smallmouth bass. In addition, polar organic chemical integrative samples (POCIS) were deployed to identify specific chemicals associated with biological observations. We did not observe biological differences across reaches indicating the absence of clear point source contributions to the observation of intersex. Interestingly, intersex prevalence and severity decreased in a stepwise manner over the timespan of the project. Intersex decreased from 92.8% to 28.1%. The only significant predictor of intersex prevalence was year of capture, based on logistic regression analysis. The mixed model of fish length and year-of-capture best predicted intersex severity. Intersex severity was also significantly different across late summer and early spring collections indicating seasonal changes in this metric. Plasma vitellogenin and liver vitellogenin Aa transcript abundance in males did not indicate exposure to estrogenic endocrine disrupting chemicals at any of the four sample collections. Analysis of chemicals captured by the POCIS as well as results of screening discrete water samples or POCIS extracts did not indicate the contribution of appreciable estrogenic chemicals. It is possible that unreported changes in land-use activity have ameliorated the problem, and our observations indicate recovery. Regardless, this work clearly emphasizes that single, snap shot sampling for intersex may not yield representative data given that the manifestation of this condition within a population can change dramatically over time.
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Affiliation(s)
- Luke R Iwanowicz
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA.
| | - A E Pinkney
- U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, Annapolis, MD, USA
| | - C P Guy
- U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, Annapolis, MD, USA
| | - A M Major
- U.S. Fish and Wildlife Service, New England Field Office, Concord, NH, USA
| | - K Munney
- U.S. Fish and Wildlife Service, New England Field Office, Concord, NH, USA
| | - V S Blazer
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
| | - D A Alvarez
- US Geological Survey, Columbia Environmental Research Center, Columbia, MO, USA
| | - H L Walsh
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
| | - A Sperry
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
| | - R Braham
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
| | - L R Sanders
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
| | - D R Smith
- U.S. Geological Survey, Leetown Science Center, Kearneysville, WV, USA
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14
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Kriete DM, McKee GR, Fonck RJ, Smith DR, Whelan GG, Yan Z. Extracting the turbulent flow-field from beam emission spectroscopy images using velocimetry. Rev Sci Instrum 2018; 89:10E107. [PMID: 30399767 DOI: 10.1063/1.5036535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/15/2018] [Indexed: 06/08/2023]
Abstract
The 2D turbulent E × B flow-field is inferred from density fluctuation images obtained with the beam emission spectroscopy diagnostic on DIII-D using the orthogonal dynamic programming velocimetry algorithm. A synthetic turbulence model is used to test the algorithm and optimize it for measuring zonal flows. Zonal flow measurements are found to require a signal-to-noise ratio above ∼10 and a zonal flow wavelength longer than ∼2 cm. Comparison between the velocimetry-estimated flow-field and the E × B flow-field using a nonlinear gyrokinetic GENE simulation finds that the flow-fields have identical spatial structure and differ only by the mean turbulence phase velocity, which is spatially uniform in this flux tube simulation.
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Affiliation(s)
- D M Kriete
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - G R McKee
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - R J Fonck
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - D R Smith
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - G G Whelan
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Z Yan
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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15
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Schneider LG, Lewis GL, Moxley RA, Smith DR. A four-season longitudinal study of enterohaemorrhagic Escherichia coli in beef cow-calf herds in Mississippi and Nebraska. Zoonoses Public Health 2018; 65:552-559. [PMID: 29573177 DOI: 10.1111/zph.12465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Indexed: 11/28/2022]
Abstract
Our objective was to describe the probability of detecting seven serogroups of enterohaemorrhagic Escherichia coli (EHEC-7) of public health importance in faecal samples from beef cow-calf herds and to test for factors associated with their detection. Fresh faecal samples (n = 85) from two Mississippi and two Nebraska herds were collected in each of four seasons. Samples were tested for each EHEC-7 serogroup by a molecular screening assay. Separate management groups within herds were sampled, and group-level factors were recorded. To measure the effects of factors on faecal shedding of EHEC-7, separate multivariable logistic regression models were used, accounting for the random effect of clustering by group within farm. Statistical significance was set α = 0.05. Fifty-nine samples (4.3%) were positive for EHEC O26, and Nebraska samples were more likely to be positive than Mississippi samples (OR = 12.4, 95% CI: 1.1, 139.2). Forty-four samples (3.2%) were positive for EHEC O45. Odds for detection were greater in the summer than all other seasons combined (OR = 4.2, 95% CI: 1.3, 14.0), and odds decreased if a precipitation event occurred (OR = 0.07, 95% CI: 0.006, 0.8). EHEC O103 was detected in 66 samples (4.9%) with increased probability to be detected at increased temperature. EHEC O111 was detected in 71 samples (5.2%), and 43 samples (3.2%) were positive for EHEC O145. Both EHEC O111 and O145 were associated separately with season, with greater probability for detection in the summer. Eighteen (1.3%) and 68 (5.0%) samples were positive for EHEC O121 and EHEC O157, respectively. We failed to detect significant explanatory factors associated with probability to detect EHEC O121 or O157. Factors that vary by time and place, such as precipitation, ambient temperature, region and season, are uniquely associated with the probability to detect EHEC-7 in fresh faeces collected from cow-calf herds.
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Affiliation(s)
- L G Schneider
- Department of Animal Science, University of Tennessee, Knoxville, TN, USA
| | - G L Lewis
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - R A Moxley
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - D R Smith
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
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16
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Wagner RT, Karisch BB, Blanton JR, Woolums A, Smith DR, Kaplan R. 95 Assessment of on-Arrival Vaccination and Deworming on Stocker Cattle Health and Growth Performance. J Anim Sci 2018. [DOI: 10.1093/jas/sky027.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- R T Wagner
- Mississippi State University, Mississippi State, MS
| | - B B Karisch
- Mississippi State University, Mississippi State, MS
| | - J R Blanton
- Mississippi State University, Mississippi State, MS
| | - A Woolums
- Mississippi State University, Mississippi State, MS
| | - D R Smith
- Mississippi State University, Mississippi State, MS
| | - R Kaplan
- Univeristy of Georgia, Athens, GA
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17
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Thomson PJ, Goodson ML, Smith DR. Treatment resistance in potentially malignant disorders-'Nature' or 'Nurture'…? J Oral Pathol Med 2017; 46:902-910. [PMID: 28891106 DOI: 10.1111/jop.12641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2017] [Indexed: 01/21/2023]
Abstract
BACKGROUND Contemporary potentially malignant disorder management is based upon provisional histological diagnosis followed by interventional surgery to excise or ablate 'high-risk' mucosal lesions. Although the majority of patients achieve disease-free status post-treatment, others develop further or persistent disease unresponsive to intervention. METHODS A detailed, retrospective clinico-pathological review of treatment resistant potentially malignant lesions, from a 590 patient cohort treated by CO2 laser surgery and followed for a mean of 7.3 years, was undertaken. Clinical outcome was determined at study census date (31 December 2014). RESULTS A total of 87 patients (15%) exhibited PMD disease resistant to treatment: 34 (6%) became disease free following further treatment, whilst 53 (9%) had persistent disease despite intervention. Disease-free patients were younger, changed lesion appearance from erythroleukoplakia to leukoplakia (P = .004), developed further lesions at new sites, demonstrated reduction in dysplasia severity with time and required multiple treatments to achieve disease-free status (P = .0005). In contrast, persistent disease patients were older, male, often presented with proliferative verrucous leukoplakia (PVL) on gingival and alveolar sites, displayed less severe dysplasia initially and underwent laser ablation rather than excision (P = .027). CONCLUSION Despite clinico-pathological profiling of treatment resistant patients, the precise inter-relationship between the inherent nature of potentially malignant disease and the external influence of treatment intervention remains obscure.
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Affiliation(s)
- P J Thomson
- Oral & Maxillofacial Surgery, School of Dentistry, Oral Health Centre, University of Queensland, Brisbane, QLD, Australia
| | - M L Goodson
- Oral & Maxillofacial Surgery, School of Dentistry, Oral Health Centre, University of Queensland, Brisbane, QLD, Australia.,Newcastle University Medicine Malaysia, Iskandar Puteri, Malaysia
| | - D R Smith
- Newcastle University Medicine Malaysia, Iskandar Puteri, Malaysia
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18
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Thomson PJ, Goodson ML, Smith DR. Profiling cancer risk in oral potentially malignant disorders-A patient cohort study. J Oral Pathol Med 2017; 46:888-895. [PMID: 28833670 DOI: 10.1111/jop.12625] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Oral potentially malignant disorders harbour variable and unpredictable risk for squamous carcinoma development. Whilst current management strategies utilise histopathological diagnoses, dysplasia grading and targeted intervention for "high-risk" lesions, clinicians are unable to predict malignant potential. METHODS Detailed, retrospective clinico-pathological analysis of potentially malignant lesions undergoing malignant transformation, from a 590 patient cohort treated by interventional laser surgery and followed for a mean of 7.3 years, was undertaken. Clinical outcome was documented at study census date (31 December 2014). RESULTS A total of 99 patients (16.8%) developed cancer: 71 (12%) seen "unexpectedly" upon excision and 28 (4.8%) progressing to malignancy at a median of 87.3 months post-surgery. Thirty "unexpected" excisions were micro-invasive (42.3%) arising primarily in severely dysplastic precursors (75%) at ventro-lateral tongue and floor of mouth sites (54.5%); 1 patient (1.4%) had a cancer-related death, whilst 58 (81.7%) were disease free. A total of 19 of 28 "progressive" cancers (67.9%) arose at new sites, with erythroleukoplakia a significant predictor of malignancy (P = .0019). Nine (32.1%) developed at the same precursor site, with 6 (77.7%) on the ventro-lateral tongue and floor of mouth. Three (10.7%) were micro-invasive, 9 patients (32.1%) died from metastatic disease and 12 (42.9%) were disease free (P < .001). CONCLUSION Squamous carcinoma may arise at the site of a precursor lesion as transformation or new-site development via field cancerisation. Whilst interventional surgery facilitates early diagnosis and treatment of occult disease, thus reducing risk from same-site transformation, new-site cancer is a significant long-term risk for patients with potentially malignant disorder.
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Affiliation(s)
- P J Thomson
- Oral & Maxillofacial Surgery, School of Dentistry, Oral Health Centre, University of Queensland, Brisbane, QLD, Australia
| | - M L Goodson
- Oral & Maxillofacial Surgery, School of Dentistry, Oral Health Centre, University of Queensland, Brisbane, QLD, Australia.,Newcastle University Medicine Malaysia, Iskandar Puteri, Malaysia
| | - D R Smith
- Newcastle University Medicine Malaysia, Iskandar Puteri, Malaysia
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19
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Goodson ML, Smith DR, Thomson PJ. Efficacy of oral brush biopsy in potentially malignant disorder management. J Oral Pathol Med 2017; 46:896-901. [PMID: 28833675 DOI: 10.1111/jop.12627] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Oral potentially malignant disorders (PMD) harbour unpredictable risk for squamous cell carcinoma development. Current management requires tissue biopsy for histopathology characterisation, dysplasia grading and targeted intervention to "high-risk" lesions, although evidence-based guidelines are limited and diagnoses subjective. This study investigated the use of adjunctive oral brush biopsy techniques during the management of PMD in a UK hospital population. METHODS Retrospective review of a 310 PMD patient cohort presenting to Maxillofacial Surgery in Newcastle upon Tyne with new, single-site lesions between December 2009 and May 2014. Patients underwent Orcellex® brush biopsy and liquid-based cytology examination in addition to conventional biopsy techniques, with management proceeding along established care pathways. Patient demographics, cytology data, most significant histopathology diagnoses and clinical outcome were all documented at the study census date (31.12.15). RESULTS A total of 170 male & 140 female patients (age range 18-91 years), exhibiting primarily leukoplakia (86.5%) at floor of mouth and ventrolateral tongue sites (44.9%), were identified. Management comprised: observation (49.7%), laser surgery (44.9%), antifungal treatment (3.5%) and Head & Neck clinic referral following cancer diagnosis (1.9%). Clinical outcomes were as follows: disease free (51.3%), persistent PMD (42.3%) and malignant transformation (6.4%). Histology and cytology diagnoses strongly correlated (r = .305). Treatment modality, lesion site, histology and cytology diagnoses were the best predictors of clinical outcome. CONCLUSIONS Orcellex® brush cytology provides reliable diagnoses consistent with conventional histopathology and offers less invasive, adjunctive assessment appropriate for long-term monitoring of patients in specialist clinics.
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Affiliation(s)
- M L Goodson
- Oral & Maxillofacial Surgery, Oral Health Centre, School of Dentistry, University of Queensland, Brisbane, QLD, Australia.,Newcastle University Medicine Malaysia, Johor, Malaysia
| | - D R Smith
- Newcastle University Medicine Malaysia, Johor, Malaysia
| | - P J Thomson
- Oral & Maxillofacial Surgery, Oral Health Centre, School of Dentistry, University of Queensland, Brisbane, QLD, Australia
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20
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Schneider LG, Klopfenstein TJ, Stromberg ZR, Lewis GL, Erickson GE, Moxley RA, Smith DR. A randomized controlled trial to evaluate the effects of dietary fibre from distillers grains on enterohemorrhagic Escherichia coli detection from the rectoanal mucosa and hides of feedlot steers. Zoonoses Public Health 2017; 65:124-133. [PMID: 28755469 DOI: 10.1111/zph.12379] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Indexed: 11/26/2022]
Abstract
Feeding high levels (≥40% dry matter) of distillers grains may increase the risk for cattle to carry enterohemorrhagic Escherichia coli (EHEC) O157. The mechanism for the increased risk is not known nor whether non-O157 EHEC are similarly affected. Our objective was to test whether the fibre content or other components of modified distillers grains plus solubles (MDGS) affects the probability for cattle to carry EHEC serogroups of public health importance. A 2 × 2 plus 1 factorial treatment arrangement within a randomized block design was utilized. Within each of four blocks, 25 feedlot pens (n = 8 steers/pen) were assigned randomly to (i) corn-based control diet; (ii) 20% dry matter (DM) MDGS; (iii) 40% DM MDGS; (iv) corn bran added to corn-based diet to match fibre of 20% MDGS or (v) 40% MDGS. Rectoanal mucosa swabs (RAMS) were collected on day (d)0, d35, d70 and d105; hide swabs were collected on the last feeding day. Samples were tested for EHEC by a molecular screening assay. The effects of fibre source and fibre level on EHEC carriage were tested using multilevel logistic regression (generalized linear mixed models; α = 0.05). EHEC O45 RAMS detection was associated with fibre level, source and sampling day. EHEC O103 RAMS detection increased by feeding 40% MDGS but not the corresponding corn bran diet. Hide contamination by EHEC O45 or O103 was less likely in cattle fed MDGS compared to corn bran diets. EHEC O111 RAMS detection decreased by feeding 40% MDGS but not by feeding the corresponding corn bran diet. Detection of EHEC O157 or O145 was not associated with dietary factors. Feeding 40% MDGS increased the probability for carriage of some EHEC serogroups but decreased probability of others, which indicated that EHEC serogroups have different risk factors associated with feeding MDGS and little association with dietary fibre.
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Affiliation(s)
- L G Schneider
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - T J Klopfenstein
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Z R Stromberg
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - G L Lewis
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - G E Erickson
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - R A Moxley
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - D R Smith
- College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
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Gollub JN, Yurduseven O, Trofatter KP, Arnitz D, F Imani M, Sleasman T, Boyarsky M, Rose A, Pedross-Engel A, Odabasi H, Zvolensky T, Lipworth G, Brady D, Marks DL, Reynolds MS, Smith DR. Large Metasurface Aperture for Millimeter Wave Computational Imaging at the Human-Scale. Sci Rep 2017; 7:42650. [PMID: 28218254 PMCID: PMC5316995 DOI: 10.1038/srep42650] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/11/2017] [Indexed: 01/29/2023] Open
Abstract
We demonstrate a low-profile holographic imaging system at millimeter wavelengths based on an aperture composed of frequency-diverse metasurfaces. Utilizing measurements of spatially-diverse field patterns, diffraction-limited images of human-sized subjects are reconstructed. The system is driven by a single microwave source swept over a band of frequencies (17.5–26.5 GHz) and switched between a collection of transmit and receive metasurface panels. High fidelity image reconstruction requires a precise model for each field pattern generated by the aperture, as well as the manner in which the field scatters from objects in the scene. This constraint makes scaling of computational imaging systems inherently challenging for electrically large, coherent apertures. To meet the demanding requirements, we introduce computational methods and calibration approaches that enable rapid and accurate imaging performance.
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Affiliation(s)
- J N Gollub
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - O Yurduseven
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - K P Trofatter
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - D Arnitz
- Department of Electrical Engineering, University of Washington, Seattle, 98195, USA
| | - M F Imani
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - T Sleasman
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - M Boyarsky
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - A Rose
- Evolv Technology, 200 West Street, Waltham, MA 02451, USA
| | - A Pedross-Engel
- Department of Electrical Engineering, University of Washington, Seattle, 98195, USA
| | - H Odabasi
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - T Zvolensky
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - G Lipworth
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - D Brady
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - D L Marks
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - M S Reynolds
- Department of Electrical Engineering, University of Washington, Seattle, 98195, USA.,Department of Computer Science and Engineering University of Washington, Seattle, WA 98195, USA
| | - D R Smith
- Center for Metamaterials and Integrated Plasmonics. Duke University, Box 90291, Durham, NC 27708, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
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22
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Martins AL, Smith DR. Records of Plaumanniana trigemmis (Konow) (Hymenoptera: Tenthredinidae) in South America. BRAZ J BIOL 2016; 77:424-425. [PMID: 27533722 DOI: 10.1590/1519-6984.00116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 04/09/2016] [Indexed: 11/22/2022] Open
Affiliation(s)
- A L Martins
- Laboratório de Biologia Comparada de Hymenoptera, Departamento de Zoologia, Universidade Federal do Paraná - UFPR, Avenida Cel. Francisco Heráclito dos Santos, s/n, Jardim das Américas, CP 19020, CEP 81530-980, Curitiba, PR, Brazil
| | - D R Smith
- Systematic Entomology Laboratory, Agricultural Research Service, United States Department of Agriculture, c/o National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 168, Washington, D.C., 20013-7012, USA
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23
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Hiolski EM, Ito S, Beggs JM, Lefebvre KA, Litke AM, Smith DR. Domoic acid disrupts the activity and connectivity of neuronal networks in organotypic brain slice cultures. Neurotoxicology 2016; 56:215-224. [PMID: 27506300 DOI: 10.1016/j.neuro.2016.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 12/22/2022]
Abstract
Domoic acid is a neurotoxin produced by algae and is found in seafood during harmful algal blooms. As a glutamate agonist, domoic acid inappropriately stimulates excitatory activity in neurons. At high doses, this leads to seizures and brain lesions, but it is unclear how lower, asymptomatic exposures disrupt neuronal activity. Domoic acid has been detected in an increasing variety of species across a greater geographical range than ever before, making it critical to understand the potential health impacts of low-level exposure on vulnerable marine mammal and human populations. To determine whether prolonged domoic acid exposure altered neuronal activity in hippocampal networks, we used a custom-made 512 multi-electrode array with high spatial and temporal resolution to record extracellular potentials (spikes) in mouse organotypic brain slice cultures. We identified individual neurons based on spike waveform and location, and measured the activity and functional connectivity within the neuronal networks of brain slice cultures. Domoic acid exposure significantly altered neuronal spiking activity patterns, and increased functional connectivity within exposed cultures, in the absence of overt cellular or neuronal toxicity. While the overall spiking activity of neurons in domoic acid-exposed cultures was comparable to controls, exposed neurons spiked significantly more often in bursts. We also identified a subset of neurons that were electrophysiologically silenced in exposed cultures, and putatively identified those neurons as fast-spiking inhibitory neurons. These results provide evidence that domoic acid affects neuronal activity in the absence of cytotoxicity, and suggest that neurodevelopmental exposure to domoic acid may alter neurological function in the absence of clinical symptoms.
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Affiliation(s)
- E M Hiolski
- Department of Microbiology & Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - S Ito
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA, USA
| | - J M Beggs
- Department of Physics, Indiana University, Bloomington, IN, USA
| | - K A Lefebvre
- Northwest Fisheries Science Center, NOAA Fisheries, Seattle, WA, USA
| | - A M Litke
- Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA, USA
| | - D R Smith
- Department of Microbiology & Environmental Toxicology, University of California, Santa Cruz, CA, USA
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24
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Weiner HL, Balashov KE, Smith DR, Khoury SJ, Hafler DA. Increased IL-12 production in progressive multiple sclerosis: Induction by activated CD4+ T cells via CD40 ligand. Mult Scler 2016. [DOI: 10.1177/135245859600200519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- H L Weiner
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - K E Balashov
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - D R Smith
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - S J Khoury
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - D A Hafler
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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25
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Moore DA, Smith DR, Sischo WM, Heaton K, Besser TE. Escherichia coli O157:H7--Discerning Facts from Fiction: An Integrated Research and Extension Project for Multiple Audiences. Zoonoses Public Health 2015; 63:72-81. [PMID: 26032584 DOI: 10.1111/zph.12206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Indexed: 11/27/2022]
Abstract
The O157:H7 (EcO157) epidemiology of Shiga-toxin-producing Escherichia coli (STEC) in cattle is complex, and myths about pre-harvest control are perpetuated. The objectives of this project were to identify perpetuated misinformation and inform four audiences about evidence-based risks and pre-harvest control of EcO157 by addressing: (i) EcO157 epidemiology and pre-harvest control; (ii) how food safety policy is created; and (iii) how to present accurate information about EcO157. An environmental scan using a daily Internet search helped identify themes for education. A literature review of pre-harvest control measures contributed to the development of educational materials (fact sheets, website, web presentations and conferences). Conference 1 was a webinar with 315 registrants, 10 countries including 41 US states and four Canadian provinces. Most participants felt confident in using their new knowledge, more than half felt confident enough to answer EcO157 questions from the public and many would recommend the recorded version of the webinar to colleagues. Conference 2 was live in the Washington, DC, area with most participants employed by the US government. All agreed that they better understood pre-harvest control, how food safety policy was made, and were confident they could create an effective message about STEC pre-harvest control. Videos were posted and received 348 Internet visitors within 2 months. Conference 3 was a webinar with a live audience and Twitter feeds, targeting people who give nutrition advice. Almost all ranked the programme good to excellent and relevant to their work. About 25% indicated that they would share: 'grass-fed beef is not safer than grain-fed', 25% would share information on effectiveness of cattle vaccines, and 14% would share information on message mapping. Across all conferences, major changes in knowledge included the following: there is no additional risk of EcO157 shedding from grain-fed versus grass-fed cattle, pre-harvest vaccination is efficacious, and production systems (pasture versus confinement) do not affect EcO157 shedding rates.
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Affiliation(s)
- D A Moore
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - D R Smith
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Starkville, MS, USA
| | - W M Sischo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - K Heaton
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - T E Besser
- Department of Veterinary Pathology and Microbiology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
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26
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Lucas EL, Bertrand P, Guazzetti S, Donna F, Peli M, Jursa TP, Lucchini R, Smith DR. Impact of ferromanganese alloy plants on household dust manganese levels: implications for childhood exposure. Environ Res 2015; 138:279-90. [PMID: 25747819 PMCID: PMC4385503 DOI: 10.1016/j.envres.2015.01.019] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/05/2015] [Accepted: 01/15/2015] [Indexed: 05/20/2023]
Abstract
Adolescents living in communities with ferromanganese alloy plant activity have been shown to exhibit deficits in olfactory and fine motor function. Household dust may serve as an important manganese (Mn) exposure pathway to children, though dust Mn concentrations have not previously been measured to assess household contamination from ferromanganese alloy plant emissions. Here we determined the association between dust concentrations and surface loadings of Mn and other metals (Al, Cd, Cr, Cu, Fe, Pb, and Zn) in indoor and outdoor household dust from three Italian communities that differ by history of ferromanganese alloy plant activity: Bagnolo Mella, with an active ferromanganese alloy plant (n=178 households); Valcamonica, with historically active plants (n=166); and Garda Lake, with no history of ferromanganese plant activity (n=99). We also evaluated Mn levels in other environmental (soil, airborne particulates) and candidate biomarker (blood, hair, saliva, fingernails) samples from children within the households. Household dust Mn concentrations and surface loadings were significantly different between the three sites, with levels highest in Bagnolo Mella (outdoor median Mn concentration=4620, range 487-183,000µg/g), intermediate in Valcamonica (median=876, range 407-8240µg/g), and lowest in Garda Lake (median=407, range 258-7240µg/g). Outdoor dust Mn concentrations in Bagnolo Mella, but not the other communities, were significantly inversely related with distance from the plant (R(2)=0.6630, P<0.0001). Moreover, outdoor dust Mn concentrations and loadings were highly predictive of but significantly higher than indoor dust Mn concentrations and loadings by ~2 to ~7-fold (Mn concentrations) and ~7 to ~20-fold (Mn loadings). Finally, both indoor and outdoor dust Mn concentrations and outdoor dust Mn loading values were highly significantly correlated with both soil and air Mn concentrations, and with children's hair and fingernail Mn concentrations, but weakly or not associated with saliva or blood Mn levels. Given the evidence associating elevated Mn exposure with neurological impairments in children, these data support that dust Mn levels should be reduced in contaminated environments to protect the health of resident children.
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Affiliation(s)
- E L Lucas
- University of California, Santa Cruz, CA 95064, USA
| | - P Bertrand
- University of California, Santa Cruz, CA 95064, USA
| | | | - F Donna
- University of Brescia, Brescia, Italy
| | - M Peli
- University of Brescia, Brescia, Italy
| | - T P Jursa
- University of California, Santa Cruz, CA 95064, USA
| | - R Lucchini
- University of California, Santa Cruz, CA 95064, USA; University of Brescia, Brescia, Italy; Ichan School of Medicine at Mount Sinai, New York, NY, USA
| | - D R Smith
- University of California, Santa Cruz, CA 95064, USA
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27
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Hayes MJ, Taylor JA, Smith DR. Introducing loupes to clinical practice: dental hygienists experiences and opinions. Int J Dent Hyg 2015; 14:226-30. [PMID: 25690424 DOI: 10.1111/idh.12128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Recent literature has identified a number of potential advantages in wearing loupes for dental hygienists, including improved quality of care and ergonomics. The aim of the study was to determine dental hygienists' opinions about wearing loupes. METHODS A short online survey was distributed to all dental hygienists who had recently participated in a study investigating the efficacy of loupes on musculoskeletal disorders; all had only worn loupes for a 6-month period, and prior to the study had not worn loupes. All of those invited completed the survey (n = 12), achieving a 100% response rate. RESULTS The majority of respondents noted that the loupes were adaptable to wear; however, only one-quarter of hygienists surveyed were wearing them often following the study. Respondents identified that the biggest advantage to loupes was calculus removal (91.7%), and most indicated that they felt the quality of their work increased when wearing loupes (75%). The biggest disadvantage to wearing loupes was the adjustment period (50%), with limited depth of vision, headache, vertigo and infection control noted by at least one-third of respondents. CONCLUSIONS This study revealed that hygienists identify both benefits and limitations to wearing loupes, and therefore, ongoing support may be required for hygienists adopting their use in clinical practice.
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Affiliation(s)
- M J Hayes
- School of Health Sciences, Faculty of Health, University of Newcastle, Ourimbah, NSW, Australia
| | - J A Taylor
- School of Health Sciences, Faculty of Health, University of Newcastle, Ourimbah, NSW, Australia
| | - D R Smith
- School of Health Sciences, Faculty of Health, University of Newcastle, Ourimbah, NSW, Australia
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28
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Gunier RB, Jerrett M, Smith DR, Jursa T, Yousefi P, Camacho J, Hubbard A, Eskenazi B, Bradman A. Determinants of manganese levels in house dust samples from the CHAMACOS cohort. Sci Total Environ 2014; 497-498:360-368. [PMID: 25146905 PMCID: PMC4177311 DOI: 10.1016/j.scitotenv.2014.08.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 07/02/2014] [Accepted: 08/04/2014] [Indexed: 05/21/2023]
Abstract
INTRODUCTION Manganese (Mn) is an essential nutrient, but at high exposure levels Mn is a neurotoxicant. The fungicides maneb and mancozeb are approximately 21% Mn by weight and more than 150,000 kg are applied each year to crops in the Salinas Valley, California. It is not clear, however, whether agricultural use of these fungicides increases Mn levels in homes. MATERIALS AND METHODS We collected house dust samples from 378 residences enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study with a second sample collected approximately nine months later from 90 of the residences. House dust samples were analyzed for Mn using inductively coupled plasma optical emission spectroscopy. Information from interviews, home inspections, and pesticide use reports was used to identify potential predictors of Mn dust concentrations and loadings. RESULTS Mn was detectable in all dust samples. The median Mn concentration was 171 μg/g and median Mn loading was 1,910 μg/m(2) at first visit. In multivariable models, Mn dust concentrations and loadings increased with the number of farmworkers in the home and the amount of agricultural Mn fungicides applied within three kilometers of the residence during the month prior to dust sample collection. Dust concentrations of Mn and other metals (lead, cadmium and chromium) were higher in residences located in the southern Salinas Valley compared those located in other areas of the Salinas Valley. Dust loadings of Mn and other metals were also higher in residences located on Antioch Loam soil than other soil types, and in homes with poor or average housekeeping practices. CONCLUSIONS Agricultural use of Mn containing fungicides was associated with Mn dust concentrations and loadings in nearby residences and farmworker homes. Housekeeping practices and soil type at residence were also important factors related to dust metal concentrations and loadings.
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Affiliation(s)
- R B Gunier
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA.
| | - M Jerrett
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - D R Smith
- Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - T Jursa
- Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
| | - P Yousefi
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - J Camacho
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - A Hubbard
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - B Eskenazi
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
| | - A Bradman
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
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29
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Degiron A, Smith DR. One-way glass for microwaves using nonreciprocal metamaterials. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 89:053203. [PMID: 25353908 DOI: 10.1103/physreve.89.053203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Indexed: 06/04/2023]
Abstract
We introduce a class of nonreciprocal metamaterials based on composite assemblies of metallic and biased ferrimagnetic elements. We show that such structures act as ultrathin one-way glasses due to the competition between two modes at the surface of the ferrimagnetic elements--a low-loss surface wave that transmits the signal on the other side of the structure and a surface spin-wave resonance that produces strong isolation levels. These findings can be adapted to existing metamaterial geometries, offering a blueprint to achieve unidirectional propagation in a variety of artificial media at radio, microwave, and millimeter wave frequencies.
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Affiliation(s)
- A Degiron
- Institut d'Electronique Fondamentale, Univ. Paris-Sud and CNRS, UMR 8622, Orsay F-91405, France
| | - D R Smith
- Center for Metamaterials and Integrated Plasmonics and Department of Electrical and Computer Engineering, Duke University, Box 90291, Durham, North Carolina 27708, USA
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Hayes MJ, Osmotherly PG, Taylor JA, Smith DR, Ho A. The effect of wearing loupes on upper extremity musculoskeletal disorders among dental hygienists. Int J Dent Hyg 2013; 12:174-9. [PMID: 23890467 DOI: 10.1111/idh.12048] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2013] [Indexed: 11/27/2022]
Abstract
OBJECTIVES It is well established that musculoskeletal disorders (MSD) are a significant occupational health issue for dentists and hygienists. Despite this, there has been little advancement in the application of ergonomic principles in the dental profession. While the use of loupes is often promoted as an ergonomic solution, there is little published research to robustly support this claim. The aim of the present study was to investigate the effect of the use of loupes on upper extremity MSD among dental hygienists. METHODS The study was conducted using an exploratory pretest and post-test design, comparing musculoskeletal measures in practising dental hygienists wearing loupes with final-year dental hygiene students who did not wear loupes. Pre- and post-test measures included valid self-reported and objective outcome measures and were measured at baseline and 6 months following the intervention. Statistical analysis was conducted as a series of mixed anovas with time and treatment as the independent variables. RESULTS The analysis revealed a significant interaction between time and treatment for the Disabilities of the Shoulder, Arm and Hand (DASH) scores (P < 0.04), indicating an improvement in symptoms for the treatment group but a reversed trend for the controls. There was also a significant mean increase in scapular position measures; however, this finding was evident in both groups, indicating that these were not a result of the intervention. CONCLUSIONS Overall, this study suggests that wearing loupes appears to have both positive and negative effects on upper extremity MSD among dental hygienists. Ongoing research is required to determine the long-term effects of loupes wear, over an extended period of time.
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Affiliation(s)
- M J Hayes
- School of Health Sciences, Faculty of Health, University of Newcastle, Ourimbah, NSW, Australia
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31
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Vogstad AR, Moxley RA, Erickson GE, Klopfenstein TJ, Smith DR. Stochastic simulation model comparing distributions of STEC O157 faecal shedding prevalence between cattle vaccinated with type III secreted protein vaccines and non-vaccinated cattle. Zoonoses Public Health 2013; 61:283-9. [PMID: 23826923 DOI: 10.1111/zph.12069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Indexed: 11/26/2022]
Abstract
Pens of cattle with high Escherichia coli O157:H7 (STEC O157) prevalence at harvest may present a greater risk to food safety than pens of lower prevalence. Vaccination of live cattle against STEC O157 has been proposed as an approach to reduce STEC O157 prevalence in live cattle. Our objective was to create a stochastic simulation model to evaluate the effectiveness of pre-harvest interventions. We used the model to compare STEC O157 prevalence distributions for summer- and winter-fed cattle to summer-fed cattle immunized with a type III secreted protein (TTSP) vaccine. Model inputs were an estimate of vaccine efficacy, observed frequency distributions for number of animals within a pen, and pen-level faecal shedding prevalence for summer and winter. Uncertainty about vaccine efficacy was simulated using a log-normal distribution (mean = 58%, SE = 0.14). Model outputs were distributions of STEC O157 faecal pen prevalence of summer-fed cattle unvaccinated and vaccinated, and winter-fed cattle unvaccinated. The simulation was performed 5000 times. Summer faecal prevalence ranged from 0% to 80% (average = 30%). Thirty-six per cent of summer-fed pens had STEC O157 prevalence >40%. Winter faecal prevalence ranged from 0% to 60% (average = 10%). Seven per cent of winter-fed pens had STEC O157 prevalence >40%. Faecal prevalence for summer-fed pens vaccinated with a 58% efficacious vaccine product ranged from 0% to 52% (average = 13%). Less than one per cent of vaccinated pens had STEC O157 prevalence >40%. In this simulation, vaccination mitigated the risk of STEC O157 faecal shedding to levels comparable to winter, with the major effects being reduced average shedding prevalence, reduced variability in prevalence distribution, and a reduction in the occurrence of the highest prevalence pens. Food safety decision-makers may find this modelling approach useful for evaluating the value of pre-harvest interventions.
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Affiliation(s)
- A R Vogstad
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
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32
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Smith DR, Ponce CH, Dilorenzo N, Quinn MJ, May ML, MacDonald JC, Luebbe MK, Bondurant RG, Galyean ML. Effects of dietary concentration of wet distillers grains on performance by newly received beef cattle, in vitro gas production and volatile fatty acid concentrations, and in vitro dry matter disappearance. J Anim Sci 2013; 91:2836-45. [PMID: 23482571 DOI: 10.2527/jas.2012-5619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Three studies were designed to evaluate effects of wet distillers grains with solubles (WDGS) on health and performance of newly received beef cattle, in vitro gas production, molar proportions and total concentrations of VFA, and IVDMD. In Exp. 1 and 2, 219 (BW = 209 kg, SE = 2.2 kg; Exp. 1) and 200 beef steers (BW = 186 kg, SE = 3.2 kg; Exp. 2) were used in randomized complete block design receiving studies. The 4 dietary treatments (DM basis) were a 65% concentrate, steam-flaked corn (SFC)-based receiving diet without WDGS (CON) or diets that contained 12.5, 25.0, or 37.5% WDGS. There were no differences among the 4 receiving diets in BW (P ≥ 0.61), ADG (P ≥ 0.75), DMI (P ≥ 0.27), and G:F (P ≥ 0.35), or in the proportion of cattle treated for morbidity from bovine respiratory disease in either of the 2 experiments. In Exp. 3, in vitro methods were used to determine the effects of WDGS on IVDMD, total gas production, and molar proportions and total concentrations of VFA. Substrates used for the incubations contained the same major components as the diets used in Exp. 1, with ruminal fluid obtained from steers fed a 60% concentrate diet. Total gas production was less (P = 0.03) for the average of the 3 WDGS substrates than for CON, with a linear decrease (P = 0.01) in total gas production as WDGS concentration increased in the substrates. In contrast to gas production, IVDMD was greater for the average of the 3 WDGS concentrations vs. CON (P ≤ 0.05) at 6 and 12 h and increased (P ≤ 0.02) with increasing WDGS concentration at 6 (linear and quadratic) and 12 h (linear) of incubation. At 48 h, there was a quadratic effect (P = 0.05) on IVDMD, with the greatest value for 25% WDGS. Molar proportion of butyrate increased linearly (P < 0.01) as the concentration of WDGS increased in the substrate, and the average of the 3 substrates containing WDGS had a greater proportion of butyrate (P = 0.03) than CON. Performance data from Exp. 1 and 2 indicate that including WDGS in the SFC-based diets for newly received cattle can be an effective at concentrations up to 37.5% of the DM. In vivo measurements are needed to corroborate the in vitro fermentation changes noted with addition of WDGS.
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Affiliation(s)
- D R Smith
- Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409, USA
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Trindade OSN, Azevedo GG, Smith DR, Silva-Júnior JC. Occurrence of the parasitoid Seminota marginata (Westwood, 1874) (Hymenoptera: Trigonalidae) in a nest of the social wasp, Apoica (Apoica) flavissima (Van der Vecht, 1973) (Hymenoptera: Vespidae). BRAZ J BIOL 2013; 72:967-8. [PMID: 23295530 DOI: 10.1590/s1519-69842012000500027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- O S N Trindade
- Departamento de Ciências Biológicas, Universidade Estadual do Sudoeste da Bahia - UESB, Av. José Moreira Sobrinho, s/n, Jequiezinho, CEP 45206-190, Jequié, BA, Brazil.
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Saleh A, Schapansky J, Smith DR, Young N, Odero GL, Aulston B, Fernyhough P, Glazner GW. Normalization of NF-κB activity in dorsal root ganglia neurons cultured from diabetic rats reverses neuropathy-linked markers of cellular pathology. Exp Neurol 2012; 241:169-78. [PMID: 23159890 DOI: 10.1016/j.expneurol.2012.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 10/05/2012] [Accepted: 11/06/2012] [Indexed: 01/12/2023]
Abstract
AIMS/HYPOTHESIS Dorsal root ganglia (DRG) sensory neurons cultured from 3 to 5 month streptozotocin (STZ)-induced diabetic rats exhibit structural and biochemical changes seen in peripheral nerve fibers in vivo, including axonal swellings, oxidative damage, reduced axonal sprouting, and decreased NF-κB activity. NF-κB is a transcription factor required by DRG neurons for survival and plasticity, and regulates transcription of antioxidant proteins (e.g. MnSOD). We hypothesized that the diabetes-induced decrease in NF-κB activity in DRG contributes to pathological phenomena observed in cultured DRG neurons from diabetic rats. METHODS NF-κB localization was assessed in intact DRG and neuron cultures using immunostaining. NF-κB activity was manipulated in sensory neuron cultures derived from age-matched normal or 3-5 month STZ-diabetic rats using pharmacological means and lentiviral expression of shRNA. The impact of diabetes and altered NF-κB activity on neuronal phenotype involved analysis of neurite outgrowth, neurite morphology, oxidative stress (lipid peroxidation) and expression of MnSOD. RESULTS STZ-induced diabetes caused a significant decrease in nuclear localization of NF-κB subunits p50 and c-rel, but no change in p65 in intact DRG. Inhibition of NF-κB in normal neuron cultures significantly increased axonal swellings and oxidative stress, and reduced both neurite outgrowth and expression of MnSOD. These phenomena mimicked markers of pathology in cultured DRG neurons from diabetic rats. Enhancement of NF-κB activity in cultured diabetic DRG neurons ameliorated the sub-optimal neurite outgrowth and MnSOD levels triggered by diabetes. Exogenous insulin enhanced nuclear localization of p50 and c-rel but not p65 in diabetic neuronal cultures. CONCLUSION/INTERPRETATION The diabetes-induced decrease of nuclear localization of NF-κB subunits p50 and c-rel in DRG contributes to development of in vitro markers of peripheral neuropathy, possibly through impaired mitochondrial ROS scavenging by deficient MnSOD.
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Affiliation(s)
- A Saleh
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB, Canada
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Abstract
The spread of African honey bees in South and Central America is one of the most remarkable and certainly among the most highly publicized instances of biological invasion. Their aggressive nest defense has led to numerous stinging incidents and even deaths; aggressiveness, coupled with a tendency to abandon the nest when disturbed, has also caused serious disruption of beekeeping and pollination industries in regions that they have invaded. The rapid spread of African bees in the Americas and their recent arrival in the United States have sparked interest in development of genetic tools for identification of honeybee populations. This in turn has renewed interest in honeybee biogeography.
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Affiliation(s)
- D R Smith
- Museum of Zoology, Insect Division, and Laboratory for Molecular Systematics, University of Michigan, Ann Arbor, MI 48109, USA
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Smith DR, Fonck RJ, McKee GR, Thompson DS. Diagnostic performance of the beam emission spectroscopy system on the National Spherical Torus Experiment. Rev Sci Instrum 2012; 83:10D502. [PMID: 23126846 DOI: 10.1063/1.4728094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The beam emission spectroscopy system on the National Spherical Torus Experiment measures localized density fluctuations on the ion gyroscale. Optical sightlines provide core to edge radial coverage, and the sightlines are aligned to typical pitch angles to maximize cross-field spatial resolution. Sightline images are 2-3 cm, and point spread function calculations indicate image distortion from pitch angle misalignment and atomic state finite lifetimes is minor with a 15% increase in the image size. New generation photodetectors achieve photon noise limited measurements at frequencies up to 400 kHz with refrigerant cooling at -20 °C. Measurements near the pedestal show broadband turbulence up to 100 kHz, and poloidal correlation lengths are about 10 cm. Plasma turbulence signals can be 2-3 orders of magnitude above photon noise and amplifier thermal noise.
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Affiliation(s)
- D R Smith
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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Ciracì C, Hill RT, Mock JJ, Urzhumov Y, Fernández-Domínguez AI, Maier SA, Pendry JB, Chilkoti A, Smith DR. Probing the ultimate limits of plasmonic enhancement. Science 2012; 337:1072-4. [PMID: 22936772 DOI: 10.1126/science.1224823] [Citation(s) in RCA: 439] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Metals support surface plasmons at optical wavelengths and have the ability to localize light to subwavelength regions. The field enhancements that occur in these regions set the ultimate limitations on a wide range of nonlinear and quantum optical phenomena. We found that the dominant limiting factor is not the resistive loss of the metal, but rather the intrinsic nonlocality of its dielectric response. A semiclassical model of the electronic response of a metal places strict bounds on the ultimate field enhancement. To demonstrate the accuracy of this model, we studied optical scattering from gold nanoparticles spaced a few angstroms from a gold film. The bounds derived from the models and experiments impose limitations on all nanophotonic systems.
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Affiliation(s)
- C Ciracì
- Center for Metamaterials and Integrated Plasmonics and Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA.
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Abstract
Our intuitive understanding of light has its foundation in the ray approximation and is intimately connected with our vision. As far as our eyes are concerned, light behaves like a stream of particles. We look inside the wavelength and study the properties of plasmonic structures with dimensions of just a few nanometers, where at a tenth or even a hundredth of the wavelength of visible light the ray picture fails. We review the concept of transformation optics that manipulates electric and magnetic field lines, rather than rays; can provide an equally intuitive understanding of subwavelength phenomena; and at the same time can be an exact description at the level of Maxwell's equations.
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Affiliation(s)
- J B Pendry
- The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, UK.
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Whankaew S, Sraphet S, Thaikert R, Smith DR, Triwitayakorn K. Characterization of microsatellite markers in cassava based on microsatellite-AFLP technique. Genet Mol Res 2012; 11:1319-26. [PMID: 22653578 DOI: 10.4238/2012.may.15.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We developed molecular markers for cassava based on the microsatellite-amplified fragment length polymorphism (M-AFLP) technique. Twenty primer pairs were developed and used for the analysis of 48 samples of Manihot species, consisting of M. esculenta (33), M. esculenta ssp flabellifolia (3), M. chlorosticta (3), M. carthaginensis (3), M. filamentosa (3), and M. tristis (3). Nine microsatellite loci that were polymorphic among these Manihot species were identified, giving 32 polymorphic alleles and from two to seven alleles per locus. Unbiased and direct count heterozygosity varied from 0.0233 to 0.7924 and 0.0000 to 0.7083, respectively. There was significant deviation (P < 0.05) from Hardy-Weinberg equilibrium at five loci. Genotypic data from the Manihot species were subjected to genetic diversity analysis. We found that M. chlorosticta and M. esculenta ssp flabellifolia were the closest populations, while M. filamentosa and M. esculenta ssp flabellifolia were the most divergent. Considering within M. esculenta, the samples from Nigeria and Fiji were the most closely related, while those from Venezuela and of unknown origin were the most divergent. We conclude that the M-AFLP technique is an effective method for generating microsatellite markers that are useful for genetic diversity analysis in Manihot species.
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Affiliation(s)
- S Whankaew
- Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
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Gheuens S, Smith DR, Wang X, Alsop DC, Lenkinski RE, Koralnik IJ. Simultaneous PML-IRIS after discontinuation of natalizumab in a patient with MS. Neurology 2012; 78:1390-3. [PMID: 22517104 DOI: 10.1212/wnl.0b013e318253d61e] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE Progressive multifocal leukoencephalopathy (PML) is a severe complication of natalizumab therapy in patients with multiple sclerosis (MS), which is often accompanied by an immune reconstitution inflammatory syndrome (IRIS) after removal of the drug. We describe a patient with MS who presented with simultaneous PML-IRIS 2 months after stopping natalizumab for other reasons. CASE REPORT AND RESULTS The patient had widespread PML and severe IRIS. He received corticosteroids and displayed a vigorous JC virus-specific cellular immune response. Elevated myoinositol and lipid/creatine peaks measured in PML lesions by proton magnetic resonance spectroscopy ((1)H-MRS) corresponded to episodes of contrast enhancement on MRI scans and persisted after the enhancement subsided. He demonstrated steady clinical improvement, but developed marked residual atrophy in areas affected by PML and inflammation, as well as seizures. CONCLUSIONS New enhancing white matter lesions, occurring after discontinuation of natalizumab, can be the manifestation of PML-IRIS rather than an MS exacerbation. Elevated myoinositol and lipid/creatine peaks appear to be more sensitive markers of inflammation in PML lesions than contrast enhancement. (1)H-MRS may become useful as a biomarker for PML-IRIS by helping clinicians determine the need for corticosteroid administration and anticipate continuing clinical recovery.
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Affiliation(s)
- S Gheuens
- Division of NeuroVirology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Riva MA, Smith DR, Cesana G. Carlo Moreschi (1876-1921): co-founder of the journal "La Medicina del Lavoro" and often forgotten pioneer of modern medicine. Med Lav 2011; 102:467-472. [PMID: 22332482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Carlo Moreschi (1876-1921) was founding co-editor of the journal "Il Lavoro" (now known as "La Medicina del Lavoro"), together with Luigi Devoto in 1901. Despite this fact, many of his pioneering contributions to 20th century scientific debate are not well known outside Italy. OBJECTIVES The aim of this paper therefore was to recall Moreschi' achievements and the groundbreaking work of this remarkable Italian physician. METHODS A comprehensive analysis was conducted on scientific papers written by Carlo Moreschi between 1901 and 1920, extending the investigation to his original manuscripts and private correspondence with family and colleagues. RESULTS Careful examination of Moreschi's work reveals several studies in the field of social medicine, epidemiology of infectious diseases, general pathology and oncology. In particular, his main interest in haematology and immunology enabled Moreschi to be one of the first to understand the mechanisms of complement fixation and the formation pathways ofantiglobulin sera. In this manner, Moreschi significantly contributed to the work of Wassermann regarding the diagnosis of syphilis, as well as contributing to the discovery of the "antiglobulin test", first described by Coombs in 1945. Furthermore, Moreschi co-founded "Il Lavoro" and "Haematologica", the oldest journals in their respective fields. CONCLUSIONS According to Devoto, Moreschi can be remembered as the archetype modern researcher and clinician. His role in the 20th century scientific debate and his pioneering work in the field of immunology and haematology, that are often forgotten due to his premature death, deserve to be reconsidered and re-assessed by the Italian and international scientific community.
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Affiliation(s)
- M A Riva
- Research Centre on Public Health, University ofMilano Bicocca, Monza, Italy.
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Stanosz GR, Smith DR, Sullivan JP, Mech AM, Gandhi KJK, Dalusky MJ, Mayfield AE, Fraedrich SW. Shoot Blight Caused by Sirococcus tsugae on Eastern Hemlock (Tsuga canadensis) in Georgia. Plant Dis 2011; 95:612. [PMID: 30731965 DOI: 10.1094/pdis-11-10-0833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Eastern hemlock (Tsuga canadensis) is an ecologically and economically important conifer from the north-central United States to the east coast of North America to the southern Appalachian Mountains. In early spring 2010, blighted shoot tips of eastern hemlock were observed at widely separated locations in the Chattahoochee National Forest in north Georgia. Damage did not appear to be directly related to hemlock woolly adelgid (Adelges tsugae) activity, which was sporadic or absent in some areas where symptoms were observed. A preliminary survey in March 2010 revealed that incidence of blighted shoots on individual trees varied, but was as high as 70%. Stems of shoots produced the previous year were frequently necrotic, had lost needles, and bore pycnidia with hyaline, two-celled conidia consistent with those of Sirococcus tsugae (2,3). Later in the spring and summer, shoots of the current year's growth became blighted, with sporulation of S. tsugae also on dead and dying needles. While S. tsugae previously has been reported on T. heterophylla, T. mertensiana, Cedrus atlantica, and C. deodara in western North America, it has only recently been reported on eastern hemlock (1), and its ability to induce shoot blight has not been proven. Pure cultures (2,3) were obtained on streptomycin-amended potato dextrose agar (PDA) and their identity was confirmed by species-specific PCR primers (4). Nuclear rDNA internal transcribed spacer sequence (554 nucleotides) also was obtained for isolate 10-05 and deposited in GenBank (Accession No. HQ256769). This sequence was found to be identical to sequences previously deposited for S. tsugae isolates. Isolate 10-05 and a second isolate (10-06) were used to inoculate potted 2-year-old eastern hemlock seedlings in a growth chamber at 20°C with a 16-h photoperiod. Conidia were collected by flooding 1-month-old colonies on PDA with sterile water. Expanding shoots on one branch of each seedling were wounded using scissors to cut the tips off needles and stems, while another branch remained nonwounded. Ten seedlings per isolate were inoculated by spraying to runoff with a suspension of 5 × 106 conidia ml-1 in sterile water, and five similarly treated control seedlings were sprayed with sterile water. Seedlings were covered with plastic bags to maintain high humidity for 4 days. Germination of conidia of each isolate incubated on water agar in this growth chamber was >80% after 24 h. Symptoms were evaluated and reisolation was attempted on streptomycin-amended PDA 2 months after inoculation. Symptoms of seedlings inoculated with either isolate included chlorotic and necrotic needle spots, browning of cut edges of needles, browning and death of needle tips and entire needles, death of stem tips with retention of dead needles, and needle loss. Symptoms of control seedlings were limited to slight browning of cut edges of needles. The fungus was reisolated from wounded shoots of 17 of 20 inoculated seedlings and nonwounded shoots of 5 of 20 inoculated seedlings and was not cultured from control seedlings. To our knowledge, this is the first report of S. tsugae in Georgia and also the first demonstration of its ability to produce symptoms that have been attributed to it on any tree species. References: (1) M. Miller-Weeks and W. Ostrofsky. USDA. Forest Service. Online publication. NA-PR-01-10, 2010. (2) A. Y. Rossman et al. For. Pathol. 38:47. (3) D. R. Smith et al. For. Pathol. 33:141, 2003. (4) D. R. Smith and G. R. Stanosz. For. Pathol. 38:156, 2008.
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Affiliation(s)
- G R Stanosz
- Department of Plant Pathology, University of Wisconsin-Madison 53706
| | - D R Smith
- Department of Plant Pathology, University of Wisconsin-Madison 53706
| | | | - A M Mech
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens 30602
| | - K J K Gandhi
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens 30602
| | - M J Dalusky
- Department of Entomology, University of Georgia, Athens 30602
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Abstract
We verify numerically and experimentally the accuracy of an analytical model used to derive the effective nonlinear susceptibilities of a varactor-loaded split ring resonator (VLSRR) magnetic medium. For the numerical validation, a nonlinear oscillator model for the effective magnetization of the metamaterial is applied in conjunction with Maxwell equations and the two sets of equations solved numerically in the time-domain. The computed second harmonic generation (SHG) from a slab of a nonlinear material is then compared with the analytical model. The computed SHG is in excellent agreement with that predicted by the analytical model, both in terms of magnitude and spectral characteristics. Moreover, experimental measurements of the power transmitted through a fabricated VLSRR metamaterial at several power levels are also in agreement with the model, illustrating that the effective medium techniques associated with metamaterials can accurately be transitioned to nonlinear systems.
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Affiliation(s)
- E Poutrina
- Center of Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708, USA.
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Ren Y, Kaye SM, Mazzucato E, Guttenfelder W, Bell RE, Domier CW, LeBlanc BP, Lee KC, Luhmann NC, Smith DR, Yuh H. Density gradient stabilization of electron temperature gradient driven turbulence in a spherical tokamak. Phys Rev Lett 2011; 106:165005. [PMID: 21599377 DOI: 10.1103/physrevlett.106.165005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Indexed: 05/30/2023]
Abstract
In this Letter we report the first clear experimental observation of density gradient stabilization of electron temperature gradient driven turbulence in a fusion plasma. It is observed that longer wavelength modes, k(⊥)ρ(s) ≲ 10, are most stabilized by density gradient, and the stabilization is accompanied by about a factor of 2 decrease in the plasma effective thermal diffusivity.
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Affiliation(s)
- Y Ren
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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Abstract
Sphaeropsis sapinea sensu lato is a conifer fungal pathogen that causes shoot blight and stem cankers. Recently, the former S. sapinea has been divided into two species, Diplodia pinea and D. scrobiculata. The aims of the study were to determine the contribution of each species in disease development on red and jack pines by means of co-inoculations and molecular identifications, and to evaluate how the presence of each species affects the development and aggressiveness of the other. Symptom severity (distance below the inoculation site at which necrotic needles were observed) and identification length (the maximum distance from inoculation site from which either D. pinea or D. scrobiculata was identified using molecular methods) were recorded 4 weeks after inoculating wounded seedlings with agar plugs colonized by these pathogens. The results suggested that D. pinea was much more aggressive on both hosts than D. scrobiculata. When a seedling was co-inoculated with these pathogens, the symptom development appeared to be mainly due to D. pinea. The presence of D. pinea also interfered with the establishment of D. scrobiculata in the plant tissue. However, D. scrobiculata showed antagonism toward D. pinea. When both pathogens co-occurred in a single seedling, symptom severity caused by D. pinea was less than when D. pinea alone was present.
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Affiliation(s)
- O Santamaría
- Department of Ingenieria del Medio Agronomico, Universidad de Extremadura, Badajoz, Spain.
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Johnson AW, Crombag HS, Smith DR, Ramanan N. Effects of serum response factor (SRF) deletion on conditioned reinforcement. Behav Brain Res 2011; 220:312-8. [PMID: 21329726 DOI: 10.1016/j.bbr.2011.02.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 02/08/2011] [Accepted: 02/08/2011] [Indexed: 01/06/2023]
Abstract
Serum response factor (SRF) is a ubiquitously expressed stimulus-dependent transcription factor that regulates gene expression by binding to serum response element in the promoter region of target genes. Recent studies in mice have shown that SRF is important for activity-dependent gene expression and synaptic plasticity in the adult brain but is dispensable for neuronal survival. Given these important functions of SRF in the CNS, it is expected to play a critical role in several aspects of learning and memory. Here we evaluated the role of SRF in conditioned reinforcement using two lines of conditional SRF mutant mice. These SRF mutant mice exhibited different spatial patterns of SRF deletion in the post-natal forebrain and notably within the hippocampus. SRF deletion was more widespread in SRF-CKCre mutants than in SRF-SynCre mutants, particularly in areas of the cortex and striatum. Mutant and wild-type mice were trained to associate one auditory cue (CS+) with reward, whereas a second cue remained relatively neutral (CS-). All mice readily acquired this discrimination, entering the food cup during CS+ but not during CS-. In a subsequent test of conditioned reinforcement, in the absence of food, wild-type control mice and SRF-SynCre mice learned to selectively perform an instrumental response that yielded CS+ presentation rather than another response that produced CS-. SRF-CKCre mutants failed to show this preferential responding for CS+. These results suggest a role for SRF in conditioned reinforcement, a manifestation of incentive learning that has been implicated in many aspects of adaptive and maladaptive behavior, such as substance abuse and eating disorders.
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Affiliation(s)
- A W Johnson
- Neurogenetics and Behavior Center, Department of Psychological & Brain Sciences, The Johns Hopkins University, Baltimore, MD, USA.
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Yuh HY, Kaye SM, Levinton FM, Mazzucato E, Mikkelsen DR, Smith DR, Bell RE, Hosea JC, LeBlanc BP, Peterson JL, Park HK, Lee W. Suppression of electron temperature gradient turbulence via negative magnetic shear in NSTX. Phys Rev Lett 2011; 106:055003. [PMID: 21405404 DOI: 10.1103/physrevlett.106.055003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Indexed: 05/30/2023]
Abstract
Negative magnetic shear is found to suppress electron turbulence and improve electron thermal transport for plasmas in the National Spherical Torus Experiment (NSTX). Sufficiently negative magnetic shear results in a transition out of a stiff profile regime. Density fluctuation measurements from high-k microwave scattering are verified to be the electron temperature gradient (ETG) mode by matching measured rest frequency and linear growth rate to gyrokinetic calculations. Fluctuation suppression under negligible E×B shear conditions confirm that negative magnetic shear alone is sufficient for ETG suppression. Measured electron temperature gradients can significantly exceed ETG critical gradients with ETG mode activity reduced to intermittent bursts, while electron thermal diffusivity improves to below 0.1 electron gyro-Bohms.
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Affiliation(s)
- H Y Yuh
- Nova Photonics Inc., Princeton, New Jersey 08540, USA.
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Landy NI, Kundtz N, Smith DR. Designing three-dimensional transformation optical media using quasiconformal coordinate transformations. Phys Rev Lett 2010; 105:193902. [PMID: 21231170 DOI: 10.1103/physrevlett.105.193902] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 09/29/2010] [Indexed: 05/30/2023]
Abstract
We introduce an approach to the design of three-dimensional transformation optical (TO) media based on a generalized quasiconformal mapping approach. The generalized quasiconformal TO (QCTO) approach enables the design of media that can, in principle, be broadband and low loss, while controlling the propagation of waves with arbitrary angles of incidence and polarization. We illustrate the method in the design of a three-dimensional carpet ground plane cloak and of a flattened Luneburg lens. Ray-trace studies provide a confirmation of the performance of the QCTO media, while also revealing the limited performance of index-only versions of these devices.
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Affiliation(s)
- N I Landy
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
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May ML, Quinn MJ, Dilorenzo N, Smith DR, Galyean ML. Effects of roughage concentration in steam-flaked corn-based diets containing wet distillers grains with solubles on feedlot cattle performance, carcass characteristics, and in vitro fermentation. J Anim Sci 2010; 89:549-59. [PMID: 21036933 DOI: 10.2527/jas.2010-3049] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two studies were conducted to evaluate effects of wet distillers grains with solubles (WDG) and dietary concentration of alfalfa hay (AH) on performance of finishing beef cattle and in vitro fermentation. In both studies, 7 treatments were arranged in a 2 × 3 + 1 factorial; factors were dietary concentrations (DM basis) of WDG (15 or 30%) and AH (7.5, 10, or 12.5%) plus a non-WDG control diet that contained 10% AH. In Exp. 1, 224 beef steers were used in a randomized complete block (initial BW 342 kg ± 9.03) finishing trial. No WDG × AH interactions were observed (P > 0.12). There were no differences among treatments in final shrunk BW or ADG (P > 0.15), and DMI did not differ with WDG concentration for the overall feeding period (P = 0.38). Increasing dietary AH concentration tended (P < 0.079) to linearly increase DMI, and linearly decreased (P < 0.05) G:F and calculated dietary NE(m) and NE(g) concentrations. Carcasses from cattle fed 15% WDG had greater yield grades (P = 0.014), with tendencies for greater 12th-rib fat (P = 0.054) and marbling score (P = 0.053) than those from cattle fed 30% WDG. There were no differences among treatments (P > 0.15) in HCW, dressing percent, LM area, KPH, proportions of cattle grading USDA Choice, and incidence of liver abscesses. In Exp. 2, ruminal fluid was collected from 2 ruminally cannulated Jersey steers adapted to a 60% concentrate diet to evaluate in vitro gas production kinetics, H(2)S production, IVDMD, and VFA. Relative to the control substrate, including WDG in substrates increased (P < 0.01) H(2)S production and decreased total gas production (P = 0.01) and rate of gas production (P = 0.03). Increasing substrate WDG from 15 to 30% increased (P < 0.05) H(2)S production and decreased (P < 0.001) total gas production, with a tendency (P = 0.073) to decrease IVDMD and fractional rate of gas production (P = 0.063). Treatments did not significantly affect (P > 0.09) molar proportions or total concentration of VFA. Results indicate that including 15 or 30% WDG in steam-flaked corn-based diets did not result in major changes in feedlot performance or carcass characteristics, but increasing AH concentration from 7.5 to 12.5% in diets containing WDG decreased G:F. Including WDG in substrates decreased rate and extent of gas production and increased H(2)S production. Changes in various measures of in vitro fermentation associated with AH concentrations were not large.
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Affiliation(s)
- M L May
- Department of Animal and Food Sciences, Texas Tech University, Box 42141, Lubbock 79409, USA.
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