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Applebaum AJ, Sannes T, Mitchell HR, McAndrew NS, Wiener L, Knight JM, Nelson AJ, Gray TF, Fank PM, Lahijani SC, Pozo-Kaderman C, Rueda-Lara M, Miran DM, Landau H, Amonoo HL. Fit for Duty: Lessons Learned from Outpatient and Homebound Hematopoietic Cell Transplantation to Prepare Family Caregivers for Home-Based Care. Transplant Cell Ther 2023; 29:143-150. [PMID: 36572386 PMCID: PMC9780643 DOI: 10.1016/j.jtct.2022.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
In the past decade, the demand for home-based care has been amplified by the Coronavirus disease 2019 pandemic. Home-based care has significant benefits for patients, their families, and healthcare systems, but it relies on the often-invisible workforce of family and friend caregivers who shoulder essential health care responsibilities, frequently with inadequate training and support. Hematopoietic cell transplantation (HCT), a potentially curative but intensive treatment for many patients with blood disorders, is being increasingly offered in home-based care settings and necessitates the involvement of family caregivers for significant patient care responsibilities. However, guidelines for supporting and preparing HCT caregivers to effectively care for their loved ones at home have not yet been established. Here, informed by the literature and our collective experience as clinicians and researchers who care for diverse patients with hematologic malignancies undergoing HCT, we provide considerations and recommendations to better support and prepare family caregivers in home-based HCT and, by extension, family caregivers supporting patients with other serious illnesses at home. We suggest tangible ways to screen family caregivers for distress and care delivery challenges, educate and train them to prepare for their caregiving role, and create an infrastructure of support for family caregivers within this emerging care delivery model.
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Affiliation(s)
- A J Applebaum
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - T Sannes
- Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - H R Mitchell
- Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, New York
| | - N S McAndrew
- College of Nursing, University of Wisconsin-Milwaukee, Milwaukee, WI, USA; Froedtert & the Medical College of Wisconsin, Froedtert Hospital, Patient Care Research, Milwaukee, Wisconsin
| | - L Wiener
- Pediatric Oncology Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD
| | - J M Knight
- Departments of Psychiatry, Medicine, and Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - A J Nelson
- Department of Psychiatry, Harvard Medical School/Massachusetts General Hospital, Boston, Massachusetts
| | - T F Gray
- Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - P M Fank
- Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, Illinois
| | - S C Lahijani
- Department of Psychiatry & Behavioral Sciences, Division of Medical Psychiatry, Stanford University School of Medicine, Palo Alto, California
| | - C Pozo-Kaderman
- Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - M Rueda-Lara
- University of Miami/Leonard Miller School of Medicine, Department of Psychiatry and Behavioral Sciences, Sylvester Comprehensive Cancer Center, Miami, Florida
| | - D M Miran
- Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - H Landau
- Adult Bone Marrow Transplant Service, Memorial Sloan Kettering Cancer Center, New York, New York
| | - H L Amonoo
- Department of Psychosocial Oncology and Palliative Care, Dana-Farber Cancer Institute, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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2
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Nelson AJ, Mehta NS, Ochoa JR, Luo C, Moussa K. Transvitreal and subretinal fibrinoid reaction following diabetic vitrectomy. Am J Ophthalmol Case Rep 2022; 27:101594. [PMID: 35664448 PMCID: PMC9157369 DOI: 10.1016/j.ajoc.2022.101594] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/12/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Andrew J. Nelson
- UC Davis Eye Center, University of California Davis, Sacramento, CA, USA
| | - Neesurg S. Mehta
- UC Davis Eye Center, University of California Davis, Sacramento, CA, USA
| | - Jorge R. Ochoa
- UC Davis Eye Center, University of California Davis, Sacramento, CA, USA
| | - Caesar Luo
- Bay Area Retina Associates, Oakland, CA, USA
| | - Kareem Moussa
- UC Davis Eye Center, University of California Davis, Sacramento, CA, USA
- Corresponding author. Department of Ophthalmology & Vision Science, 4860 Y St, Suite 2400, Sacramento, CA, 95817, USA.
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3
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Al-Bazz DY, Nelson AJ, Burgess J, Petropoulos IN, Nizza J, Marshall A, Brown E, Cuthbertson DJ, Marshall AG, Malik RA, Alam U. Is Nerve Electrophysiology a Robust Primary Endpoint in Clinical Trials of Treatments for Diabetic Peripheral Neuropathy? Diagnostics (Basel) 2022; 12:diagnostics12030731. [PMID: 35328284 PMCID: PMC8947384 DOI: 10.3390/diagnostics12030731] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 12/10/2022] Open
Abstract
There is currently no FDA-approved disease-modifying therapy for diabetic peripheral neuropathy (DPN). Nerve conduction velocity (NCV) is an established primary endpoint of disease-modifying therapies in DPN and clinical trials have been powered with an assumed decline of 0.5 m/s/year. This paper sought to establish the time-dependent change in NCV associated with a placebo, compared to that observed in the active intervention group. A literature search identified twenty-one double-blind, randomised controlled trials in DPN of ≥1 year duration conducted between 1971 and 2021. We evaluated changes in neurophysiology, with a focus on peroneal motor and sural sensory NCV and amplitude in the placebo and treatment groups. There was significant variability in the change and direction of change (reduction/increase) in NCV in the placebo arm, as well as variability influenced by the anatomical site of neurophysiological measurement within a given clinical trial. A critical re-evaluation of efficacy trials should consider placebo-adjusted effects and present the placebo-subtracted change in NCV rather than assume a universal annual decline of 0.5 m/s/year. Importantly, endpoints such as corneal confocal microscopy (CCM) have demonstrated early nerve repair, whilst symptoms and NCV have not changed, and should thus be considered as a viable alternative.
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Affiliation(s)
- Dalal Y. Al-Bazz
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
- Correspondence: (D.Y.A.-B.); or (U.A.); Tel.: +44-151-529-5920 (U.A.)
| | - Andrew J. Nelson
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
| | - Jamie Burgess
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
| | - Ioannis N. Petropoulos
- Research Division, Weill Cornell Medicine-Qatar, Qatar Foundation, Education City, Doha 24144, Qatar; (I.N.P.); (R.A.M.)
| | - Jael Nizza
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
| | - Anne Marshall
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
| | - Emily Brown
- Obesity and Endocrinology Research Group, Institute of Life Course and Medical Sciences, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (E.B.); (D.J.C.)
| | - Daniel J. Cuthbertson
- Obesity and Endocrinology Research Group, Institute of Life Course and Medical Sciences, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (E.B.); (D.J.C.)
| | - Andrew G. Marshall
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
- Institute of Cardiovascular Sciences, Cardiac Centre, Faculty of Medical and Human Sciences, University of Manchester and NIHR/Wellcome Trust Clinical Research Facility, Manchester M13 9WL, UK
| | - Rayaz A. Malik
- Research Division, Weill Cornell Medicine-Qatar, Qatar Foundation, Education City, Doha 24144, Qatar; (I.N.P.); (R.A.M.)
- Institute of Cardiovascular Sciences, Cardiac Centre, Faculty of Medical and Human Sciences, University of Manchester and NIHR/Wellcome Trust Clinical Research Facility, Manchester M13 9WL, UK
| | - Uazman Alam
- Institute of Life Course and Medical Sciences and the Pain Research Institute, University of Liverpool and Liverpool University Hospital NHS Foundation Trust, Liverpool L9 7AL, UK; (A.J.N.); (J.B.); (J.N.); (A.M.); (A.G.M.)
- Division of Diabetes, Endocrinology and Gastroenterology, Institute of Human Development, University of Manchester, Manchester M13 9PL, UK
- Correspondence: (D.Y.A.-B.); or (U.A.); Tel.: +44-151-529-5920 (U.A.)
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Nelson AJ, Zheng Q, Lavis LD, Ryan TA. Molecular cartography: charting the sea of molecular organization in live synapses with nanoscale precision. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Shen YI, Nelson AJ, Oberlin BG. Virtual reality intervention effects on future self-continuity and delayed reward preference in substance use disorder recovery: pilot study results. Discov Ment Health 2022; 2:19. [PMID: 36128578 PMCID: PMC9477176 DOI: 10.1007/s44192-022-00022-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 08/17/2022] [Indexed: 02/02/2023]
Abstract
Sustained remission from substance use disorder (SUD) is challenged by high relapse rates, which provides opportunities for novel clinical interventions. Immersive virtual reality (VR) permits delivering synthetic experiences that feel real and actualizes otherwise impossible scenarios for therapeutic benefit. We report on the feasibility of an immersive VR intervention designed to increase valuation of the future by enhancing future self-continuity and leveraging future self-discrepancy with personalized future selves as SUD recovery support. Twenty-one adults in early SUD recovery (< 1 year) interacted with versions of themselves age-progressed fifteen years from two different behavioral trajectories: an SUD Future Self and a Recovery Future Self. The future selves' interactive monologs include personalized details and voice for a lifelike interaction within a time travel vignette. Before and following the intervention, participants rated future self-continuity and performed delay discounting. Following the intervention, daily images of the Recovery Future Self were sent to participants' smartphones for thirty days. The VR intervention generated no adverse events, was well tolerated (presence, liking, and comfort), and significantly increased future self-continuity and delayed reward preference (doubling delay tolerance). The intervention also reduced craving, ps < 0.05. Thirty days later, n = 18 remained abstinent; importantly, increased future self-similarity persisted. Abstainers' future self-similarity increased following VR. All individual participants showing increased future self-similarity post-VR remained abstinent, and all participants who relapsed showed either reduced or zero effect on future self-similarity. Post-intervention semi-structured interviews revealed emotional engagement with the experience. VR simulation of imagined realities reifies novel clinical interventions that are practicable and personalized. The current study demonstrates an implementation readily applied in the clinic and shows promise for facilitating SUD recovery. Creative collaboration between researchers, clinicians, and VR developers has great potential to revolutionize mental health interventions and expand the range of tools for clinicians targeting SUD and other disorders. Supplementary Information The online version contains supplementary material available at 10.1007/s44192-022-00022-1.
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Affiliation(s)
- Yitong I. Shen
- Department of Psychiatry, Indiana University School of Medicine, 355 W 16th St. Ste 4800, Indianapolis, IN 46202 USA ,Department of Psychology, Indiana University Purdue University Indianapolis, Indianapolis, IN USA
| | | | - Brandon G. Oberlin
- Department of Psychiatry, Indiana University School of Medicine, 355 W 16th St. Ste 4800, Indianapolis, IN 46202 USA ,Department of Psychology, Indiana University Purdue University Indianapolis, Indianapolis, IN USA ,Department of Neurology, Indiana University School of Medicine, Indianapolis, IN USA ,Stark Neurosciences Research Institute, Indianapolis, IN USA
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6
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Aggleton JP, Yanakieva S, Sengpiel F, Nelson AJ. The separate and combined properties of the granular (area 29) and dysgranular (area 30) retrosplenial cortex. Neurobiol Learn Mem 2021; 185:107516. [PMID: 34481970 DOI: 10.1016/j.nlm.2021.107516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/27/2021] [Accepted: 08/30/2021] [Indexed: 12/31/2022]
Abstract
Retrosplenial cortex contains two principal subdivisions, area 29 (granular) and area 30 (dysgranular). Their respective anatomical connections in the rat brain reveal that area 29 is the primary recipient of hippocampal and parahippocampal spatial and contextual information while area 30 is the primary interactor with current visual information. Lesion studies and measures of neuronal activity in rodents indicate that retrosplenial cortex helps to integrate space from different perspectives, e.g., egocentric and allocentric, providing landmark and heading cues for navigation and spatial learning. It provides a repository of scene information that, over time, becomes increasingly independent of the hippocampus. These processes, reflect the interactive actions between areas 29 and 30, along with their convergent influences on cortical and thalamic targets. Consequently, despite their differences, both areas 29 and 30 are necessary for an array of spatial and learning problems.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff, Wales CF10 3AT, UK.
| | - Steliana Yanakieva
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff, Wales CF10 3AT, UK
| | - Frank Sengpiel
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, Wales CF10 3AX, UK
| | - Andrew J Nelson
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff, Wales CF10 3AT, UK
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7
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Wyatt TA, Nemecek M, Chandra D, DeVasure JM, Nelson AJ, Romberger DJ, Poole JA. Organic dust-induced lung injury and repair: Bi-directional regulation by TNFα and IL-10. J Immunotoxicol 2020; 17:153-162. [PMID: 32634062 DOI: 10.1080/1547691x.2020.1776428] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 12/15/2022] Open
Abstract
Exposure to organic dust increases chronic airway inflammatory disorders. Effective treatment strategies are lacking. It has been reported that hog barn dust extracts (HDE) induce TNFα through protein kinase C (PKC) activation and that lung inflammation is enhanced in scavenger receptor A (SRA/CD204) knockout (KO) mice following HDE. Because interleukin (IL)-10 production can limit excessive inflammation, it was hypothesized here that HDE-induced IL-10 would require CD204 to effect inflammatory responses. C57BL/6 wild-type (WT), SRA KO, and IL-10 KO mice were intranasally challenged daily for 8 days with HDE and subsequently rested for 3 days with/without recombinant IL-10 (rIL-10) treatment. Primary peritoneal macrophages (PM) and murine alveolar macrophages (MH-S cells) were treated in vitro with HDE, SRA ligand (fucoidan), rIL-10, and/or PKC isoform inhibitors. HDE induced in vivo lung IL-10 in WT, but not SRA KO mice, and similar trends were demonstrated in isolated PM from same treated mice. Lung lymphocyte aggregates and neutrophils were elevated in in vivo HDE-treated SRA and IL-10 KO mice after a 3-d recovery, and treatment during recovery with rIL-10 abrogated these responses. In vitro rIL-10 treatment reduced HDE-stimulated TNFα release in MH-S and WT PM. In SRA KO macrophages, there was reduced IL-10 and PKC zeta (ζ) activity and increased TNFα following in vitro HDE stimulation. Similarly, blocking SRA (24 hr fucoidan pre-treatment) resulted in enhanced HDE-stimulated macrophage TNFα and decreased IL-10 and PKCζ activation. PKCζ inhibitors blocked HDE-stimulated IL-10, but not TNFα. Collectively, HDE stimulates IL-10 by an SRA- and PKCζ-dependent mechanism to regulate TNFα. Enhancing resolution of dust-mediated lung inflammation through targeting IL-10 and/or SRA may represent new approaches to therapeutic interventions.
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Affiliation(s)
- T A Wyatt
- Pulmonary, Critical Care, and Sleep, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE, USA.,Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - M Nemecek
- Pulmonary, Critical Care, and Sleep, University of Nebraska Medical Center, Omaha, NE, USA.,Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE, USA
| | - D Chandra
- Pulmonary, Critical Care, and Sleep, University of Nebraska Medical Center, Omaha, NE, USA
| | - J M DeVasure
- Pulmonary, Critical Care, and Sleep, University of Nebraska Medical Center, Omaha, NE, USA
| | - A J Nelson
- Allergy and Immunology Divisions, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - D J Romberger
- Pulmonary, Critical Care, and Sleep, University of Nebraska Medical Center, Omaha, NE, USA.,Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - J A Poole
- Allergy and Immunology Divisions, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
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8
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Welsh H, Nelson AJ, van der Merwe AE, de Boer HH, Brickley MB. An Investigation of Micro-CT Analysis of Bone as a New Diagnostic Method for Paleopathological Cases of Osteomalacia. Int J Paleopathol 2020; 31:23-33. [PMID: 32927328 DOI: 10.1016/j.ijpp.2020.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 06/04/2020] [Revised: 08/03/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVE This paper looks to broaden the methodological possibilities for diagnosing osteomalacia in archaeological bone using micro-CT analysis. Increasing the identification of osteomalacia in paleopathology will provide support for important interpretive frameworks. MATERIALS Nine embedded and two unembedded rib fragments were sourced from St. Martin's Birmingham and Ancaster, UK, and Lisieux Michelet, France. Of the 11 samples, nine were previously confirmed as osteomalacic, and presented with varying levels of diagenesis and two were non-osteomalacic controls, one of which exhibits diagenetic change. METHODS Micro-CT, backscattered scanning electron microscopy, and light microscopy were employed. Micro-CT images were evaluated for osteomalacic features using corresponding microscopic images. RESULTS Micro-CT images from osteomalacic samples demonstrated the presence of defective mineralization adjacent to cement lines, areas of incomplete mineralization, and resorptive bays/borders, three key diagnostic features of osteomalacia. Diagenetic change was also detectable in micro-CT images, but did not prevent the diagnosis of osteomalacia. CONCLUSIONS Micro-CT analysis is a non-destructive method capable of providing microstructural images of osteomalacic features in embedded and unembedded samples. When enough of these features are present, micro-CT images are capable of confirming a diagnosis of osteomalacia. SIGNIFICANCE Vitamin D deficiency has important health consequences which operate throughout the life course. Increasing the ability to detect cases of vitamin D deficiency provides researchers with a greater understanding of health and disease in past communities. LIMITATIONS Only adult rib samples were used. SUGGESTIONS FOR FURTHER RESEARCH Paleopathologists should look to test the utility of micro-CT analysis in diagnosing active rickets in subadult individuals.
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Affiliation(s)
- H Welsh
- Department of Anthropology, McMaster University, Hamilton, ON, L8S 4L9, Canada.
| | - A J Nelson
- Departments of Anthropology and Chemistry, Bone and Joint Institute, The University of Western Ontario, London, ON, N6A 5C3, Canada
| | - A E van der Merwe
- Department of Medical Biology, Section Clinical Anatomy and Embryology, Amsterdam University Medical Centres, Location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H H de Boer
- Department of Pathology, Amsterdam University Medical Centers, location AMC, Amsterdam, The Netherlands; Department of Forensic Medicine, Netherlands Forensic Institute, The Hague, The Netherlands
| | - M B Brickley
- Department of Anthropology, McMaster University, Hamilton, ON, L8S 4L9, Canada
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9
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Abstract
The relationship between regionally tied institutional logics and the location of organizations is an important issue in organization theory. Recent work highlights how supportive regional logics can give rise to products or organizations that resonate with these logics and how the geographic patterns that underlie industries may be understood by examining such relationships. This literature has not, however, offered deep attention to the ways in which features of technology—specifically, its inherent uncertainty—may interact with such dynamics. In this paper, we tackle the challenge. Our work examines how the level of support for an environmental-conservation logic within a region is associated with the number of wind and solar equipment manufacturers in that region in the years 1978–2006. By simultaneously exploring the effects of this logic on two similar technologies, our work not only reinforces how logics may interact with organizational activity but also shows how the magnitude and mechanisms of this effect depend on the technology in question. We build on these findings to discuss the importance of examining technologies in detail, including their dimensions of uncertainty, the role of timing in examining the effect of regionally tied logics, and the links between public policy and logics.
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Affiliation(s)
| | - Michael V. Russo
- Lundquist College of Business, University of Oregon, Eugene, Oregon 97403
| | - Andrew J. Nelson
- Lundquist College of Business, University of Oregon, Eugene, Oregon 97403
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Chang R, Nelson AJ, LeTran V, Vu B, Burkemper B, Chu Z, Fard A, Kashani AH, Xu BY, Wang RK, Varma R, Richter GM. Systemic Determinants of Peripapillary Vessel Density in Healthy African Americans: The African American Eye Disease Study. Am J Ophthalmol 2019; 207:240-247. [PMID: 31229463 DOI: 10.1016/j.ajo.2019.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE To determine the relationship between systemic factors and radial peripapillary capillary (RPC) vessel density (VD) in healthy African American (AA) participants of the African American Eye Disease Study. DESIGN A population-based, cross-sectional study. METHODS A total of 4135 eyes from 2127 AA participants aged 40 years and older in Inglewood, California, were imaged for 6×6-mm optic disc scans on a spectral-domain optical coherence tomography angiography (OCTA) device. Of these, 1029 eyes from 1029 participants who met the inclusion and exclusion criteria were analyzed, including only 1 eye per participant. Custom software was used to quantify RPC VD. Multivariate linear regression was used to identify systemic factors associated with RPC VD with a significance level set at 0.05. The contribution of each variable to the final model was estimated with the magnitude of standardized regression coefficients (SRCs). The fit of the final model was measured by R2. RESULTS The average RPC VD was 0.346±0.045. Controlling for signal strength, the systemic variables in the final multivariate model associated with reduced RPC VD were older age (β = -0.0123 per decade; SRC = -0.2733; P < .0001), male sex (β = -0.0067; SRC = -0.0716; P = .0060), and longer diabetes duration (β = -0.0022 per 5 years; SRC = -0.0527; P = .0427). The model R2 was 0.3689. CONCLUSIONS Age, sex, and systemic influences, such as diabetes duration, need to be considered when assessing changes in RPC VD in glaucoma and other ocular diseases. Longitudinal studies are needed to investigate whether reduced RPC VD and the factors that affect it are associated with an increased risk of developing glaucomatous nerve damage.
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Affiliation(s)
- Ryuna Chang
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Andrew J Nelson
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Vivian LeTran
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Brian Vu
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Bruce Burkemper
- Southern California Eyecare and Vision Research Institute, Los Angeles, California, USA
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Ali Fard
- Carl Zeiss Meditec, Inc, Dublin, California, USA
| | - Amir H Kashani
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Benjamin Y Xu
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Rohit Varma
- Southern California Eyecare and Vision Research Institute, Los Angeles, California, USA
| | - Grace M Richter
- USC Roski Eye Institute, Keck Medicine of University of Southern California, Los Angeles, California, USA.
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I. Eyeing the past: synchrotron µ-XANES and XRF imaging of tarnish distribution on 19th century daguerreotypes. J Synchrotron Radiat 2019; 26:1679-1686. [PMID: 31490159 DOI: 10.1107/s1600577519006313] [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] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/03/2019] [Indexed: 06/10/2023]
Abstract
Louis-Jacques-Mandé Daguerre introduced the first successful photographic process, the daguerreotype, in 1839. Tarnished regions on daguerreotypes supplied by the National Gallery of Canada were examined using scanning electron microscopy energy-dispersive X-ray spectroscopy and synchrotron-radiation analysis. Synchrotron X-ray fluorescence imaging visualized the distribution of sulfur and chlorine, two primary tarnish contributors, and showed that they were associated with the distribution of image particles on the surface. X-ray absorption near-edge structure spectroscopy determined the tarnish to be primarily composed of AgCl and Ag2S. Au2S, Au2SO4, HAuCl4 and HgSO4 were also observed to be minor contributors. Environmental contamination may be a source of these degradation compounds. Implications of these findings will be discussed.
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Affiliation(s)
- M S Kozachuk
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - T K Sham
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - R R Martin
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - A J Nelson
- The Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - I Coulthard
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
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Nelson AJ, Chang R, LeTran V, Vu B, Burkemper B, Chu Z, Fard A, Kashani A, Xu B, Wang R, Varma R, Richter GM. Ocular Determinants of Peripapillary Vessel Density in Healthy African Americans: The African American Eye Disease Study. Invest Ophthalmol Vis Sci 2019; 60:3368-3373. [PMID: 31917454 PMCID: PMC6681862 DOI: 10.1167/iovs.19-27035] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/03/2019] [Indexed: 01/01/2023] Open
Abstract
Purpose The African American (AA) population has unique ocular anatomic characteristics and a disproportionately high incidence of glaucoma, which is associated with lower peripapillary vessel density (VD). This study aimed to identify ocular determinants of peripapillary VD in healthy AAs. Methods This was a cross-sectional, population-based study of 1029 AAs, ages 40 and older. Participants underwent examination to obtain axial length (AL), IOP, central corneal thickness (CCT), mean retinal nerve fiber layer (RNFL) thickness, visual field mean deviation (MD), and 6 × 6-mm optical coherence tomography angiography scans of the optic nerve. Participants with glaucoma, vision-threatening diabetic retinopathy, or other relevant ocular disease were excluded. Prototype software was used to quantify VD. A multivariable regression model, controlling for age and signal strength, identified the ocular variables that predicted peripapillary VD. The contribution of each variable was assessed with the magnitude of standardized regression coefficients (SRC). Results Based on univariate regressions, AL, RNFL thickness, and MD had significant associations with peripapillary VD (all P < 0.001). In the final multivariate model, lower mean RNFL thickness (β = 0.0022, P < 0.001, SRC = 0.542) and longer AL (β = -0.0055, P < 0.001, SRC = -0.118) were associated with lower peripapillary VD, controlling for age and signal strength, with model R2 of 0.69. Conclusions Thinner RNFL and longer AL were the most influential ocular determinants of lower peripapillary perfusion in healthy AA eyes. Additional research is needed to clarify whether longer AL increases risk of glaucoma by affecting capillary perfusion.
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Affiliation(s)
- Andrew J. Nelson
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
| | - Ryuna Chang
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
| | - Vivian LeTran
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
| | - Brian Vu
- University of Colorado School of Medicine, Aurora, Colorado, United States
| | - Bruce Burkemper
- Departments of Preventive Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Washington, United States
| | - Ali Fard
- Carl Zeiss Meditec, Dublin, California, United States
| | - Amir Kashani
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
| | - Benjamin Xu
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
| | - Ruikang Wang
- Department of Bioengineering, University of Washington, Washington, United States
| | - Rohit Varma
- Southern California Eye Institute, CHA Hollywood Presbyterian Medical Center, Los Angeles, California, United States
| | - Grace M. Richter
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of the University of Southern California, California, United States
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Jewlal E, Barr K, Nelson AJ, Laird DW, Willmore KE. Relationship of Phenotypic Variation with Mechanisms of Craniofacial Development in Two Connexin‐43 Mutant Mouse Models. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.774.19] [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: 11/11/2022]
Affiliation(s)
- Elizabeth Jewlal
- Anatomy & Cell BiologyWestern UniversityLondonONCanada
- Bone & Joint InstituteWestern UniversityLondonONCanada
| | - Kevin Barr
- Anatomy & Cell BiologyWestern UniversityLondonONCanada
| | | | - Dale W Laird
- Anatomy & Cell BiologyWestern UniversityLondonONCanada
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Knowles NK, Langohr GDG, Faieghi M, Nelson AJ, Ferreira LM. A comparison of density-modulus relationships used in finite element modeling of the shoulder. Med Eng Phys 2019; 66:40-46. [PMID: 30833224 DOI: 10.1016/j.medengphy.2019.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 04/06/2018] [Revised: 11/29/2018] [Accepted: 02/10/2019] [Indexed: 10/27/2022]
Abstract
Subject- and site-specific modeling techniques greatly improve the accuracy of computational models derived from clinical-resolution quantitative computed tomography (QCT) data. The majority of shoulder finite element (FE) studies use density-modulus relationships developed for alternative anatomical locations. As such, the objectives of this study were to compare the six most commonly used density-modulus relationships in shoulder finite element (FE) studies. To achieve this, ninety-eight (98) virtual trabecular bone cores were extracted from uCT scans of scapulae from 14 cadaveric specimens (7 male; 7 female). Homogeneous tissue moduli of 20 GPa, and heterogeneous tissue moduli scaled by CT-intensity were considered. Micro finite element models (µ-FEMs) of each virtual core were compressively loaded to 0.5% apparent strain and apparent strain energy density (SEDapp) was collected. Each uCT virtual core was then co-registered to clinical QCT images, QCT-FEMs created, and each of the 6 density-modulus relationships applied (6 × 98 = 588 QCT-FEMs). The loading and boundary conditions were replicated and SEDapp was collected and compared to µ-FEM SEDapp. When a homogeneous tissue modulus was considered in the µ-FEMs, SEDapp was best predicted in QCT-FEMs with the density-modulus relationship developed from pooled anatomical locations (QCT-FEM SEDapp = 0.979µ-FEM SEDapp + 0.0066, r2 = 0.933). A different density-modulus relationship best predicted SEDapp (QCT-FEM SEDapp = 1.014µ-FEM SEDapp + 0.0034, r2 = 0.935) when a heterogeneous tissue modulus was considered. This study compared density-modulus relationships used in shoulder FE studies using an independent computational methodology for comparing these relationships.
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Affiliation(s)
- Nikolas K Knowles
- School of Biomedical Engineering, The University of Western Ontario, London, ON, Canada; Roth
- McFarlane Hand and Upper Limb Centre, Bioengineering Laboratory, Surgical Mechatronics Laboratory, St. Josephs Health Care, 268 Grosvenor St., London, ON, Canada; Collaborative Training Program in MSK Health Research, and Bone and Joint Institute, The University of Western Ontario, London, ON, Canada
| | - G Daniel G Langohr
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, ON, Canada; Roth
- McFarlane Hand and Upper Limb Centre, Bioengineering Laboratory, Surgical Mechatronics Laboratory, St. Josephs Health Care, 268 Grosvenor St., London, ON, Canada; Collaborative Training Program in MSK Health Research, and Bone and Joint Institute, The University of Western Ontario, London, ON, Canada
| | - Mohammadreza Faieghi
- School of Biomedical Engineering, The University of Western Ontario, London, ON, Canada
| | - Andrew J Nelson
- Department of Anthropology, The University of Western Ontario, London, ON, Canada; Collaborative Training Program in MSK Health Research, and Bone and Joint Institute, The University of Western Ontario, London, ON, Canada; Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Louis M Ferreira
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, ON, Canada; Roth
- McFarlane Hand and Upper Limb Centre, Bioengineering Laboratory, Surgical Mechatronics Laboratory, St. Josephs Health Care, 268 Grosvenor St., London, ON, Canada; Collaborative Training Program in MSK Health Research, and Bone and Joint Institute, The University of Western Ontario, London, ON, Canada.
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Affiliation(s)
- Andrew J. Nelson
- Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Lower Lane, Liverpool, UK
| | - Rasheed Zakaria
- Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Lower Lane, Liverpool, UK
| | | | - Andrew R. Brodbelt
- Department of Neurosurgery, The Walton Centre NHS Foundation Trust, Lower Lane, Liverpool, UK
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Srivastava K, Bozic KJ, Silverton C, Nelson AJ, Makhni EC, Davis JJ. Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision. J Bone Joint Surg Am 2019; 101:14-24. [PMID: 30601412 DOI: 10.2106/jbjs.17.00874] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Periprosthetic joint infection (PJI) following total knee arthroplasty is a growing concern, as the demand for total knee arthroplasty (TKA) expands annually. Although 2-stage revision is considered the gold standard in management, there is substantial morbidity and mortality associated with this strategy. One-stage revision is associated with lower mortality rates and better quality of life, and there has been increased interest in utilizing the 1-stage strategy. However, surgeons are faced with a difficult decision regarding which strategy to use to treat these infections, considering uncertainty with respect to eradication of infection, quality of life, and societal costs with each strategy. The purpose of the current study was to use decision analysis to determine the optimal decision for the management of PJI following TKA. METHODS An expected-value decision tree was constructed to estimate the quality-adjusted life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created: Decision Tree 1 was constructed for all pathogens, and Decision Tree 2 was constructed solely for difficult-to-treat infections, including methicillin-resistant infections. Values for parameters in the decision model, such as mortality rate, reinfection rate, and need for additional surgeries, were derived from the literature. Medical costs were derived from Medicare data. Sensitivity analysis determined which parameters in the decision model had the most influence on the optimal strategy. RESULTS In both decision trees, the 1-stage strategy produced greater health utility while also being more cost-effective. In the Monte Carlo simulation for Decision Trees 1 and 2, 1-stage was the dominant strategy in about 85% and 69% of the trials, respectively. Sensitivity analysis showed that the reinfection and 1-year mortality rates were the most sensitive parameters influencing the optimal decision. CONCLUSIONS Despite 2-stage revision being considered the current gold standard for infection eradication in patients with PJI following TKA, the optimal decision that produced the highest quality of life was 1-stage revision. These results should be considered in shared decision-making with patients who experience PJI following TKA. LEVEL OF EVIDENCE Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Karan Srivastava
- Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan
| | - Kevin J Bozic
- Department of Orthopaedic Surgery, University of Texas at Austin Dell Medical School, Austin, Texas
| | - Craig Silverton
- Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan
| | - Andrew J Nelson
- Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan
| | - Eric C Makhni
- Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan
| | - Jason J Davis
- Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I, McElhone JP. Author Correction: Recovery of Degraded-Beyond-Recognition 19th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission. Sci Rep 2018; 8:12158. [PMID: 30089846 PMCID: PMC6082915 DOI: 10.1038/s41598-018-30576-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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18
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Alam U, Nelson AJ, Cuthbertson DJ, Malik RA. An update on vitamin D and B deficiency in the pathogenesis and treatment of diabetic neuropathy: a narrative review. Future Neurology 2018. [DOI: 10.2217/fnl-2017-0034] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diabetic peripheral neuropathy (DPN) is highly prevalent and affects up to 50% of patients with diabetes. Painful neuropathic symptoms may occur in a third of patients with diabetes and is a major cause of sleep disturbance, morbidity and poor quality of life. Effective treatment of DPN remains a major challenge as current therapeutic options have a number of undesirable side effects and only provide a partial response to neuropathic pain. Furthermore, there are a lack of treatments that modulate the natural history of DPN. A growing body of evidence suggests that vitamin B and vitamin D may have analgesic effects and neuroprotective benefits in DPN. This narrative review explores the role of these vitamins in DPN. Given their limited side effects, further mechanistic studies and good quality randomized controlled trials of their putative analgesic ability are required to define the role of vitamin B and D in DPN.
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Affiliation(s)
- Uazman Alam
- Department of Eye & Vision Sciences, Diabetes & Endocrinology Research & the Pain Research Institute, Institute of Ageing & Chronic Disease, University of Liverpool & Aintree University Hospital NHS Foundation Trust, Liverpool, L9 7AL, United Kingdom
- Department of Diabetes & Endocrinology, Royal Liverpool & Broadgreen University NHS Hospital Trust, Liverpool, L7 8XP, United Kingdom
- Division of Endocrinology, Diabetes & Gastroenterology, University of Manchester, Manchester, M13 9MT, United Kingdom
| | - Andrew J Nelson
- Department of Eye & Vision Sciences, Diabetes & Endocrinology Research & the Pain Research Institute, Institute of Ageing & Chronic Disease, University of Liverpool & Aintree University Hospital NHS Foundation Trust, Liverpool, L9 7AL, United Kingdom
| | - Daniel J Cuthbertson
- Department of Eye & Vision Sciences, Diabetes & Endocrinology Research & the Pain Research Institute, Institute of Ageing & Chronic Disease, University of Liverpool & Aintree University Hospital NHS Foundation Trust, Liverpool, L9 7AL, United Kingdom
| | - Rayaz A Malik
- Weill Cornell Medicine – Qatar, Qatar Foundation – Education City, P.O. Box 24144, Doha, Qatar
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, M13 9MT, United Kingdom
- School of Healthcare Science, Manchester Metropolitan University, Manchester, M15 6BH, United Kingdom
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Kozachuk MS, Sham TK, Martin RR, Nelson AJ, Coulthard I, McElhone JP. Recovery of Degraded-Beyond-Recognition 19 th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission. Sci Rep 2018; 8:9565. [PMID: 29934565 PMCID: PMC6015064 DOI: 10.1038/s41598-018-27714-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 10/10/2017] [Accepted: 06/05/2018] [Indexed: 11/22/2022] Open
Abstract
A daguerreotype image, the first commercialized photographic process, is composed of silver-mercury, and often silver-mercury-gold amalgam particles on the surface of a silver-coated copper plate. Specular and diffuse reflectance of light from these image particles produces the range of gray tones that typify these 19th century images. By mapping the mercury distribution with rapid-scanning, synchrotron-based micro-X-ray fluorescence (μ-XRF) imaging, full portraits, which to the naked eye are obscured entirely by extensive corrosion, can be retrieved in a non-invasive, non-contact, and non-destructive manner. This work furthers the chemical understanding regarding the production of these images and suggests that mercury is retained in the image particles despite surface degradation. Most importantly, μ-XRF imaging provides curators with an image recovery method for degraded daguerreotypes, even if the artifact’s condition is beyond traditional conservation treatments.
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Affiliation(s)
- Madalena S Kozachuk
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Tsun-Kong Sham
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.
| | - Ronald R Martin
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Andrew J Nelson
- The University of Western Ontario, The Department of Chemistry, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.,The University of Western Ontario, The Department of Anthropology, 1151 Richmond Street, London, Ontario, N6A 5C2, Canada
| | - Ian Coulthard
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, SK, S7N 2V3, Canada.
| | - John P McElhone
- National Gallery of Canada, Musée des beaux-arts du Canada, 380 Sussex Drive, P.O. Box 427, Station A, Ottawa, Ontario, K1N 9N4, Canada
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Weatherly LM, Nelson AJ, Shim J, Riitano AM, Gerson ED, Hart AJ, de Juan-Sanz J, Ryan TA, Sher R, Hess ST, Gosse JA. Antimicrobial agent triclosan disrupts mitochondrial structure, revealed by super-resolution microscopy, and inhibits mast cell signaling via calcium modulation. Toxicol Appl Pharmacol 2018; 349:39-54. [PMID: 29630968 DOI: 10.1016/j.taap.2018.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/22/2018] [Accepted: 04/04/2018] [Indexed: 01/15/2023]
Abstract
The antimicrobial agent triclosan (TCS) is used in products such as toothpaste and surgical soaps and is readily absorbed into oral mucosa and human skin. These and many other tissues contain mast cells, which are involved in numerous physiologies and diseases. Mast cells release chemical mediators through a process termed degranulation, which is inhibited by TCS. Investigation into the underlying mechanisms led to the finding that TCS is a mitochondrial uncoupler at non-cytotoxic, low-micromolar doses in several cell types and live zebrafish. Our aim was to determine the mechanisms underlying TCS disruption of mitochondrial function and of mast cell signaling. We combined super-resolution (fluorescence photoactivation localization) microscopy and multiple fluorescence-based assays to detail triclosan's effects in living mast cells, fibroblasts, and primary human keratinocytes. TCS disrupts mitochondrial nanostructure, causing mitochondria to undergo fission and to form a toroidal, "donut" shape. TCS increases reactive oxygen species production, decreases mitochondrial membrane potential, and disrupts ER and mitochondrial Ca2+ levels, processes that cause mitochondrial fission. TCS is 60 × more potent than the banned uncoupler 2,4-dinitrophenol. TCS inhibits mast cell degranulation by decreasing mitochondrial membrane potential, disrupting microtubule polymerization, and inhibiting mitochondrial translocation, which reduces Ca2+ influx into the cell. Our findings provide mechanisms for both triclosan's inhibition of mast cell signaling and its universal disruption of mitochondria. These mechanisms provide partial explanations for triclosan's adverse effects on human reproduction, immunology, and development. This study is the first to utilize super-resolution microscopy in the field of toxicology.
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Affiliation(s)
- Lisa M Weatherly
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA; Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Andrew J Nelson
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Juyoung Shim
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Abigail M Riitano
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Erik D Gerson
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA
| | - Andrew J Hart
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA
| | | | - Timothy A Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Roger Sher
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Samuel T Hess
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA; Department of Physics and Astronomy, University of Maine, Orono, ME, USA.
| | - Julie A Gosse
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA; Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME, USA.
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Anthony C, Nelson AJ, Tripsas M. “Who Are You?…I Really Wanna Know”: Product Meaning and Competitive Positioning in the Nascent Synthesizer Industry. Strategy Science 2016. [DOI: 10.1287/stsc.2016.0015] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Nelson AJ. How to Share “A Really Good Secret”: Managing Sharing/Secrecy Tensions Around Scientific Knowledge Disclosure. Organization Science 2016. [DOI: 10.1287/orsc.2015.1040] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Asmussen MJ, Bailey AZ, Nelson AJ. Cortical and corticospinal output modulations during reaching movements with varying directions and magnitudes of interaction torques. Neuroscience 2015; 311:268-83. [PMID: 26525892 DOI: 10.1016/j.neuroscience.2015.10.032] [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: 09/11/2015] [Revised: 10/14/2015] [Accepted: 10/16/2015] [Indexed: 10/22/2022]
Abstract
The neural command required to coordinate a multi-joint movement is inherently complex. During multi-joint movement of the limb, the force created from movement at one joint may create a torque at a second joint known as an interaction torque. Interaction torques may be assistive or resistive thereby aiding or opposing the motion of the second joint, respectively. For movement to be effectively controlled, the central nervous system should modulate neural output to the muscles to appropriately account for interaction torques. The present study examined the neural output from the primary motor cortex before and during reaching movements that required different combinations of assistive and resistive interaction torques occurring at the shoulder and elbow joints. Using transcranial magnetic stimulation to probe neural output from the primary motor cortex, results indicate that corticospinal output controlling the upper arm is related to resistive interaction torques occurring at the shoulder joint. Further, cortical output to bi-articular muscles is associated with interaction torque and this may be driven by the fact that these muscles are in an advantageous position to control torques produced between inter-connection segments. Humans have a tendency to avoid reaching movements that involve resistive interaction torques and this may be driven by the requirement of increased neural output associated with these movements.
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Affiliation(s)
- M J Asmussen
- Department of Kinesiology, McMaster University, Hamilton L8S 4K1, Canada.
| | - A Z Bailey
- Department of Kinesiology, McMaster University, Hamilton L8S 4K1, Canada.
| | - A J Nelson
- Department of Kinesiology, McMaster University, Hamilton L8S 4K1, Canada.
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Crowhurst JC, Jeffries JR, Åberg D, Zaug JM, Dai ZR, Siekhaus WJ, Teslich NE, Holliday KS, Knight KB, Nelson AJ, Hutcheon ID. A combined theoretical and experimental investigation of uranium dioxide under high static pressure. J Phys Condens Matter 2015; 27:265401. [PMID: 26053594 DOI: 10.1088/0953-8984/27/26/265401] [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] [Indexed: 06/04/2023]
Abstract
We have investigated the behavior of uranium dioxide (UO2) under high static pressure using a combination of experimental and theoretical techniques. We have made Raman spectroscopic measurements up to 87 GPa, electrical transport measurements up to 50 GPa from 10 K to room temperature, and optical transmission measurements up to 28 GPa. We have also carried out theoretical calculations within the GGA + U framework. We find that Raman frequencies match to a large extent, theoretical predictions for the cotunnite (Pnma) structure above 30 GPa, but at higher pressures some behavior is not captured theoretically. The Raman measurements also imply that the low-pressure fluorite phase coexists with the cotunnite phase up to high pressures, consistent with earlier reports. Electrical transport measurements show that the resistivity decreases by more than six orders of magnitude with increasing pressure up to 50 GPa but that the material never adopts archetypal metallic behavior. Optical transmission spectra show that while UO2 becomes increasingly opaque with increasing pressure, a likely direct optical band gap of more than 1 eV exists up to at least 28 GPa. Together with the electrical transport measurements, we conclude that the high pressure electrical conductivity of UO2 is mediated by variable-range hopping.
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Affiliation(s)
- J C Crowhurst
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA 94551, USA
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Beckett RG, Nelson AJ. Mummy Restoration Project Among the Anga of Papua New Guinea. Anat Rec (Hoboken) 2015; 298:1013-25. [DOI: 10.1002/ar.23139] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 01/30/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Ronald G. Beckett
- Bioanthropology Research Institute; College of Health Sciences, Quinnipiac University; Tucson Arizona USA
| | - Andrew J. Nelson
- Office of the Dean, Faculty of Social Science, Department of Anthropology; The University of Western Ontario; London Canada
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Curthoys NM, Parent M, Mlodzianoski M, Nelson AJ, Lilieholm J, Butler MB, Valles M, Hess ST. Dances with Membranes: Breakthroughs from Super-resolution Imaging. Curr Top Membr 2015; 75:59-123. [PMID: 26015281 PMCID: PMC5584789 DOI: 10.1016/bs.ctm.2015.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Biological membrane organization mediates numerous cellular functions and has also been connected with an immense number of human diseases. However, until recently, experimental methodologies have been unable to directly visualize the nanoscale details of biological membranes, particularly in intact living cells. Numerous models explaining membrane organization have been proposed, but testing those models has required indirect methods; the desire to directly image proteins and lipids in living cell membranes is a strong motivation for the advancement of technology. The development of super-resolution microscopy has provided powerful tools for quantification of membrane organization at the level of individual proteins and lipids, and many of these tools are compatible with living cells. Previously inaccessible questions are now being addressed, and the field of membrane biology is developing rapidly. This chapter discusses how the development of super-resolution microscopy has led to fundamental advances in the field of biological membrane organization. We summarize the history and some models explaining how proteins are organized in cell membranes, and give an overview of various super-resolution techniques and methods of quantifying super-resolution data. We discuss the application of super-resolution techniques to membrane biology in general, and also with specific reference to the fields of actin and actin-binding proteins, virus infection, mitochondria, immune cell biology, and phosphoinositide signaling. Finally, we present our hopes and expectations for the future of super-resolution microscopy in the field of membrane biology.
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Affiliation(s)
- Nikki M. Curthoys
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Matthew Parent
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | | | - Andrew J. Nelson
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Jennifer Lilieholm
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Michael B. Butler
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Matthew Valles
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Samuel T. Hess
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
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Stephen AJ, Wegscheider PK, Nelson AJ, Dickey JP. Quantifying the precision and accuracy of the MicroScribe G2X three-dimensional digitizer. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.daach.2015.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Styron JD, Cooper GW, Ruiz CL, Hahn KD, Chandler GA, Nelson AJ, Torres JA, McWatters BR, Carpenter K, Bonura MA. Predicting the sensitivity of the beryllium/scintillator layer neutron detector using Monte Carlo and experimental response functions. Rev Sci Instrum 2014; 85:11E617. [PMID: 25430363 DOI: 10.1063/1.4896176] [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: 06/04/2023]
Abstract
A methodology for obtaining empirical curves relating absolute measured scintillation light output to beta energy deposited is presented. Output signals were measured from thin plastic scintillator using NIST traceable beta and gamma sources and MCNP5 was used to model the energy deposition from each source. Combining the experimental and calculated results gives the desired empirical relationships. To validate, the sensitivity of a beryllium/scintillator-layer neutron activation detector was predicted and then exposed to a known neutron fluence from a Deuterium-Deuterium fusion plasma (DD). The predicted and the measured sensitivity were in statistical agreement.
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Affiliation(s)
- J D Styron
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - G W Cooper
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - C L Ruiz
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - K D Hahn
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G A Chandler
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - A J Nelson
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J A Torres
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - B R McWatters
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Ken Carpenter
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - M A Bonura
- Department of Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
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Bonura MA, Ruiz CL, Fehl DL, Cooper GW, Chandler G, Hahn KD, Nelson AJ, Styron JD, Torres JA. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic rays. Rev Sci Instrum 2014; 85:11D633. [PMID: 25430209 DOI: 10.1063/1.4896958] [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: 06/04/2023]
Abstract
An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF's) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.
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Affiliation(s)
- M A Bonura
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - C L Ruiz
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA
| | - D L Fehl
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA
| | - G W Cooper
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - G Chandler
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA
| | - K D Hahn
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA
| | - A J Nelson
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - J D Styron
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - J A Torres
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA
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Nguyen N, Mulla A, Nelson AJ, Wilson TD. Visuospatial anatomy comprehension: the role of spatial visualization ability and problem-solving strategies. Anat Sci Educ 2014; 7:280-288. [PMID: 24124041 DOI: 10.1002/ase.1415] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [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: 04/03/2013] [Revised: 07/12/2013] [Accepted: 09/10/2013] [Indexed: 06/02/2023]
Abstract
The present study explored the problem-solving strategies of high- and low-spatial visualization ability learners on a novel spatial anatomy task to determine whether differences in strategies contribute to differences in task performance. The results of this study provide further insights into the processing commonalities and differences among learners beyond the classification of spatial visualization ability alone, and help elucidate what, if anything, high- and low-spatial visualization ability learners do differently while solving spatial anatomy task problems. Forty-two students completed a standardized measure of spatial visualization ability, a novel spatial anatomy task, and a questionnaire involving personal self-analysis of the processes and strategies used while performing the spatial anatomy task. Strategy reports revealed that there were different ways students approached answering the spatial anatomy task problems. However, chi-square test analyses established that differences in problem-solving strategies did not contribute to differences in task performance. Therefore, underlying spatial visualization ability is the main source of variation in spatial anatomy task performance, irrespective of strategy. In addition to scoring higher and spending less time on the anatomy task, participants with high spatial visualization ability were also more accurate when solving the task problems.
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Affiliation(s)
- Ngan Nguyen
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada
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Hahn KD, Cooper GW, Ruiz CL, Fehl DL, Chandler GA, Knapp PF, Leeper RJ, Nelson AJ, Smelser RM, Torres JA. Fusion-neutron-yield, activation measurements at the Z accelerator: design, analysis, and sensitivity. Rev Sci Instrum 2014; 85:043507. [PMID: 24784607 DOI: 10.1063/1.4870779] [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] [Indexed: 06/03/2023]
Abstract
We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r(2) decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm(2) and is ∼ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.
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Affiliation(s)
- K D Hahn
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - G W Cooper
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - C L Ruiz
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - D L Fehl
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - G A Chandler
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - P F Knapp
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - R J Leeper
- Los Alamos National Laboratories, Plasma Physics Group, Los Alamos, New Mexico 87545, USA
| | - A J Nelson
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - R M Smelser
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
| | - J A Torres
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123, USA
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Abstract
Resolution describes the smallest details within a sample that can be recovered by a microscope lens system. For optical microscopes detecting visible light, diffraction limits the resolution to ∼200-250 nm. In contrast, localization measures the position of an isolated object using its image. Single fluorescent molecules can be localized with an uncertainty of a few tens of nanometres, and in some cases less than one nanometre. Superresolution fluorescence localization microscopy (SRFLM) images and localizes fluorescent molecules in a sample. By controlling the visibility of the fluorescent molecules with light, it is possible to cause a sparse subset of the tags to fluoresce and be spatially separated from each other. A movie is acquired with a camera, capturing images of many sets of visible fluorescent tags over a period of time. The movie is then analysed by a computer whereby all of the single molecules are independently measured, and their positions are recorded. When the coordinates of a sufficient number of molecules are collected, an image can be rendered by plotting the coordinates of the localized molecules. The spatial resolution of these rendered images can be better than 20 nm, roughly an order of magnitude better than the diffraction limited resolution. The invention of SRFLM has led to an explosion of related techniques. Through the use of specialized optics, the fluorescent signal can be split into multiple detection channels. These channels can capture additional information such as colour (emission wavelength), orientation and three-dimensional position of the detected molecules. Measurement of the colour of the detected fluorescence can allow researchers to distinguish multiple types of fluorescent tags and to study the interaction between multiple molecules of interest. Three-dimensional imaging and determination of molecular orientations offer insight into structural organization of the sample. SRFLM is compatible with living samples and has helped to illuminate many dynamic biological processes, such as the trajectories of molecules within living cells. This review discusses the concept and process of SRFLM imaging and investigates recent advances in SRFLM functionality. Since its announcement in 2006, SRFLM has been quickly adopted and modified by many researchers to help investigate questions whose answers lie below the diffraction limit. The versatility of the SRFLM technique has great promise for improving our understanding of cell biology at the molecular level.
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Affiliation(s)
- A J Nelson
- Department of Physics and Astronomy and Institute for Molecular Biophysics, University of Maine, Orono, Maine, U.S.A
| | - S T Hess
- Department of Physics and Astronomy and Institute for Molecular Biophysics, University of Maine, Orono, Maine, U.S.A
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Sikdar S, Rangwala H, Eastlake EB, Hunt IA, Nelson AJ, Devanathan J, Shin A, Pancrazio JJ. Novel Method for Predicting Dexterous Individual Finger Movements by Imaging Muscle Activity Using a Wearable Ultrasonic System. IEEE Trans Neural Syst Rehabil Eng 2013; 22:69-76. [PMID: 23996580 DOI: 10.1109/tnsre.2013.2274657] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recently there have been major advances in the electro-mechanical design of upper extremity prosthetics. However, the development of control strategies for such prosthetics has lagged significantly behind. Conventional noninvasive myoelectric control strategies rely on the amplitude of electromyography (EMG) signals from flexor and extensor muscles in the forearm. Surface EMG has limited specificity for deep contiguous muscles because of cross talk and cannot reliably differentiate between individual digit and joint motions. We present a novel ultrasound imaging based control strategy for upper arm prosthetics that can overcome many of the limitations of myoelectric control. Real time ultrasound images of the forearm muscles were obtained using a wearable mechanically scanned single element ultrasound system, and analyzed to create maps of muscle activity based on changes in the ultrasound echogenicity of the muscle during contraction. Individual digit movements were associated with unique maps of activity. These maps were correlated with previously acquired training data to classify individual digit movements. Preliminary results using ten healthy volunteers demonstrated this approach could provide robust classification of individual finger movements with 98% accuracy (precision 96%-100% and recall 97%-100% for individual finger flexions). The change in ultrasound echogenicity was found to be proportional to the digit flexion speed (R(2)=0.9), and thus our proposed strategy provided a proportional signal that can be used for fine control. We anticipate that ultrasound imaging based control strategies could be a significant improvement over conventional myoelectric control of prosthetics.
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Richardson JD, Bertaso AG, Frost L, Psaltis PJ, Carbone A, Koschade B, Wong DT, Nelson AJ, Paton S, Williams K, Azarisman S, Worthley MI, Teo KS, Gronthos S, Zannettino ACW, Worthley SG. Cardiac magnetic resonance, transthoracic and transoesophageal echocardiography: a comparison of in vivo assessment of ventricular function in rats. Lab Anim 2013; 47:291-300. [PMID: 23836849 DOI: 10.1177/0023677213494373] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In vivo assessment of ventricular function in rodents has largely been restricted to transthoracic echocardiography (TTE). However 1.5 T cardiac magnetic resonance (CMR) and transoesophageal echocardiography (TOE) have emerged as possible alternatives. Yet, to date, no study has systematically assessed these three imaging modalities in determining ejection fraction (EF) in rats. Twenty rats underwent imaging four weeks after surgically-induced myocardial infarction. CMR was performed on a 1.5 T scanner, TTE was conducted using a 9.2 MHz transducer and TOE was performed with a 10 MHz intracardiac echo catheter. Correlation between the three techniques for EF determination and analysis reproducibility was assessed. Moderate-strong correlation was observed between the three modalities; the greatest between CMR and TOE (intraclass correlation coefficient (ICC) = 0.89), followed by TOE and TTE (ICC = 0.70) and CMR and TTE (ICC = 0.63). Intra- and inter-observer variations were excellent with CMR (ICC = 0.99 and 0.98 respectively), very good with TTE (0.90 and 0.89) and TOE (0.87 and 0.84). Each modality is a viable option for evaluating ventricular function in rats, however the high image quality and excellent reproducibility of CMR offers distinct advantages even at 1.5 T with conventional coils and software.
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Affiliation(s)
- J D Richardson
- Cardiovascular Research Centre, Royal Adelaide Hospital and Department of Medicine, University of Adelaide, South Australia, Australia
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Duncan RF, Dundon BK, Nelson AJ, Williams K, Carbone A, Worthley MI, Zaman A, Worthley SG. 1029“MRI phase-encoded tissue velocity mapping for the
non-invasive estimation of left ventricular diastolic filling pressure: A
MRI-cardiac catheterisation comparison study”. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet070ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ruiz CL, Chandler GA, Cooper GW, Fehl DL, Hahn KD, Leeper RJ, McWatters BR, Nelson AJ, Smelser RM, Snow CS, Torres JA. Progress in obtaining an absolute calibration of a total deuterium-tritium neutron yield diagnostic based on copper activation. Rev Sci Instrum 2012; 83:10D913. [PMID: 23126916 DOI: 10.1063/1.4729495] [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 350-keV Cockroft-Walton accelerator at Sandia National laboratory's Ion Beam facility is being used to calibrate absolutely a total DT neutron yield diagnostic based on the (63)Cu(n,2n)(62)Cu(β+) reaction. These investigations have led to first-order uncertainties approaching 5% or better. The experiments employ the associated-particle technique. Deuterons at 175 keV impinge a 2.6 μm thick erbium tritide target producing 14.1 MeV neutrons from the T(d,n)(4)He reaction. The alpha particles emitted are measured at two angles relative to the beam direction and used to infer the neutron flux on a copper sample. The induced (62)Cu activity is then measured and related to the neutron flux. This method is known as the F-factor technique. Description of the associated-particle method, copper sample geometries employed, and the present estimates of the uncertainties to the F-factor obtained are given.
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Affiliation(s)
- C L Ruiz
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
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Gatu Johnson M, Frenje JA, Casey DT, Li CK, Séguin FH, Petrasso R, Ashabranner R, Bionta RM, Bleuel DL, Bond EJ, Caggiano JA, Carpenter A, Cerjan CJ, Clancy TJ, Doeppner T, Eckart MJ, Edwards MJ, Friedrich S, Glenzer SH, Haan SW, Hartouni EP, Hatarik R, Hatchett SP, Jones OS, Kyrala G, Le Pape S, Lerche RA, Landen OL, Ma T, MacKinnon AJ, McKernan MA, Moran MJ, Moses E, Munro DH, McNaney J, Park HS, Ralph J, Remington B, Rygg JR, Sepke SM, Smalyuk V, Spears B, Springer PT, Yeamans CB, Farrell M, Jasion D, Kilkenny JD, Nikroo A, Paguio R, Knauer JP, Glebov VY, Sangster TC, Betti R, Stoeckl C, Magoon J, Shoup MJ, Grim GP, Kline J, Morgan GL, Murphy TJ, Leeper RJ, Ruiz CL, Cooper GW, Nelson AJ. Neutron spectrometry--an essential tool for diagnosing implosions at the National Ignition Facility (invited). Rev Sci Instrum 2012; 83:10D308. [PMID: 23126835 DOI: 10.1063/1.4728095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [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
DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Y(n), T(i), and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρR(tot) (g∕cm(2)) = (20.4 ± 0.6) × dsr(10-12 MeV). The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Y(n), has improved almost two orders of magnitude since the first shot in September, 2010.
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Affiliation(s)
- M Gatu Johnson
- Massachusetts Institute of Technology Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
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Nelson AJ, Ruiz CL, Cooper GW, Chandler GA, Fehl DL, Hahn KD, Leeper RJ, Smelser R, Torres JA. A novel method for modeling the neutron time of flight detector response in current mode to inertial confinement fusion experiments (invited). Rev Sci Instrum 2012; 83:10D915. [PMID: 23126918 DOI: 10.1063/1.4742140] [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
A novel method for modeling the neutron time of flight (nTOF) detector response in current mode for inertial confinement fusion experiments has been applied to the on-axis nTOF detectors located in the basement of the Z-Facility. It will be shown that this method can identify sources of neutron scattering, and is useful for predicting detector responses in future experimental configurations, and for identifying potential sources of neutron scattering when experimental set-ups change. This method can also provide insight on how much broadening neutron scattering contributes to the primary signals, which is then subtracted from them. Detector time responses are deconvolved from the signals, allowing a transformation from dN/dt to dN/dE, extracting neutron spectra at each detector location; these spectra are proportional to the absolute yield.
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Affiliation(s)
- A J Nelson
- Department of Chemical & Nuclear Engineering, University of New Mexico, Albuquerque, 87131, USA.
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Cooper GW, Ruiz CL, Leeper RJ, Chandler GA, Hahn KD, Nelson AJ, Torres JA, Smelser RM, McWatters BR, Bleuel DL, Yeamans CB, Knittel KM, Casey DT, Frenje JA, Gatu Johnson M, Petrasso RD, Styron JD. Copper activation deuterium-tritium neutron yield measurements at the National Ignition Facility. Rev Sci Instrum 2012; 83:10D918. [PMID: 23126920 DOI: 10.1063/1.4746999] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A DT neutron yield diagnostic based on the reactions, (63)Cu(n,2n)(62)Cu(β(+)) and (65)Cu(n,2n)( 64) Cu(β(+)), has been fielded at the National Ignition Facility (NIF). The induced copper activity is measured using a NaI γ-γ coincidence system. Uncertainties in the 14-MeV DT yield measurements are on the order of 7% to 8%. In addition to measuring yield, the ratio of activities induced in two, well-separated copper samples are used to measure the relative anisotropy of the fuel ρR to uncertainties as low as 5%.
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Affiliation(s)
- G W Cooper
- Chemical and Nuclear Engineering Department, University of New Mexico, Albuquerque, 87131, USA.
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Casey DT, Frenje JA, Gatu Johnson M, Séguin FH, Li CK, Petrasso RD, Glebov VY, Katz J, Knauer JP, Meyerhofer DD, Sangster TC, Bionta RM, Bleuel DL, Döppner T, Glenzer S, Hartouni E, Hatchett SP, Le Pape S, Ma T, MacKinnon A, McKernan MA, Moran M, Moses E, Park HS, Ralph J, Remington BA, Smalyuk V, Yeamans CB, Kline J, Kyrala G, Chandler GA, Leeper RJ, Ruiz CL, Cooper GW, Nelson AJ, Fletcher K, Kilkenny J, Farrell M, Jasion D, Paguio R. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF. Rev Sci Instrum 2012; 83:10D912. [PMID: 23126915 DOI: 10.1063/1.4738657] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.
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Affiliation(s)
- D T Casey
- Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139, USA.
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Hahn KD, Ruiz CL, Cooper GW, Nelson AJ, Chandler GA, Leeper RJ, McWatters BR, Smelser RM, Torres JA. Calibration of neutron-yield diagnostics in attenuating and scattering environments. Rev Sci Instrum 2012; 83:10D914. [PMID: 23126917 DOI: 10.1063/1.4732067] [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
We have performed absolute calibrations of a fusion-neutron-yield copper-activation diagnostic in environments that significantly attenuate and scatter neutrons. We have measured attenuation and scattering effects and have compared the measurements to Monte Carlo simulations using the Monte Carlo N-Particle code. We find that measurements and simulations are consistent within 10%.
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Affiliation(s)
- K D Hahn
- Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87111, USA.
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Wade AD, Garvin GJ, Hurnanen JH, Williams LL, Lawson B, Nelson AJ, Tampieri D. Scenes from the Past: Multidetector CT of Egyptian Mummies of the Redpath Museum. Radiographics 2012; 32:1235-50. [PMID: 22787004 DOI: 10.1148/rg.324125704] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andrew D Wade
- Department of Anthropology, Social Science Centre, University of Western Ontario, 1151 Richmond St N, London, ON, Canada N6A 5C2.
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Nguyen N, Mulla A, Nelson AJ, Wilson TD. Problem solving strategies and the relationship between visualization ability and spatial anatomy task performance. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.12.2] [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: 11/11/2022]
Affiliation(s)
- Ngan Nguyen
- Anatomy and Cell BiologyThe University of Western OntarioLondonONCanada
| | - Ali Mulla
- School of KinesiologyThe University of Western OntarioLondonONCanada
| | | | - Timothy D Wilson
- Anatomy and Cell BiologyThe University of Western OntarioLondonONCanada
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Nguyen N, Nelson AJ, Wilson TD. Computer visualizations: factors that influence spatial anatomy comprehension. Anat Sci Educ 2012; 5:98-108. [PMID: 22232125 DOI: 10.1002/ase.1258] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 11/21/2011] [Accepted: 12/09/2011] [Indexed: 05/31/2023]
Abstract
Computer visualizations are increasingly common in education across a range of subject disciplines, including anatomy. Despite optimism about their educational potential, students sometime have difficulty learning from these visualizations. The purpose of this study was to explore a range of factors that influence spatial anatomy comprehension before and after instruction with different computer visualizations. Three major factors were considered: (1) visualization ability (VZ) of learners, (2) dynamism of the visual display, and (3) interactivity of the system. Participants (N = 60) of differing VZs (high, low) studied a group of anatomical structures in one of three visual conditions (control, static, dynamic) and one of two interactive conditions (interactive, non-interactive). Before and after the study phase, participants' comprehension of spatial anatomical information was assessed using a multiple-choice spatial anatomy task (SAT) involving the mental rotation of the anatomical structures, identification of the structures in 2D cross-sections, and localization of planes corresponding to given cross-sections. Results indicate that VZ had a positive influence on SAT performance but instruction with different computer visualizations could modulate the effect of VZ on task performance.
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Affiliation(s)
- Ngan Nguyen
- Department of Anatomy and Cell Biology, Corps for Research of Instructional and Perceptual Technologies (CRIPT), Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
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Rai N, Premji A, Tommerdahl M, Nelson AJ. Continuous theta-burst rTMS over primary somatosensory cortex modulates tactile perception on the hand. Clin Neurophysiol 2011; 123:1226-33. [PMID: 22100859 DOI: 10.1016/j.clinph.2011.09.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/21/2011] [Accepted: 09/24/2011] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Theta-burst stimulation (TBS) over the primary somatosensory cortex (SI) alters cortical excitability, and in its intermittent form (iTBS) improves tactile spatial acuity. The effects of continuous TBS (cTBS) on tactile acuity remain unknown. The present study examined the influence of cTBS over SI on temporal and spatial tactile acuity on the contralateral hand. METHODS In separate experiments, temporal discrimination threshold (TDT) and spatial amplitude discrimination threshold (SDT) were obtained from the right hand before and for up to 34 min following real and sham cTBS (600 pulses) over left-hemisphere SI. RESULTS CTBS reduced temporal and spatial tactile acuity for up to 18 min following real cTBS. Tactile acuity was unaltered in the groups receiving sham cTBS. CONCLUSIONS CTBS over SI impairs both temporal and spatial domains of tactile acuity for a similar duration. SIGNIFICANCE CTBS over SI appears to decrease neural activity within targeted cortex and has potential utility in reducing excessive sensory processing.
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Affiliation(s)
- N Rai
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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Richardson JD, Nelson AJ, Worthley SG, Teo KSL, Baillie T, Worthley MI. Multivessel coronary artery spasm. Heart Lung Circ 2011; 21:113-6. [PMID: 21852191 DOI: 10.1016/j.hlc.2011.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 07/22/2011] [Indexed: 11/29/2022]
Abstract
Coronary spasm is increasingly recognised as an important aetiological mechanism causing myocardial ischaemia. Occasionally cases present with evidence of ST segment elevation myocardial infarction, usually secondary to spasm confined to a solitary coronary artery. We present the rare and life-threatening case of severe coronary spasm afflicting all three major epicardial arteries simultaneously. It describes the difficult emergency scenario and ongoing management dilemmas encountered by physicians confronted with multivessel coronary spasm. Moreover we discuss the malignant prognosis associated with this ailment and describe the potential insights provided by cardiac magnetic resonance imaging that might identify those at greatest risk after the index event.
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Affiliation(s)
- J D Richardson
- Cardiovascular Research Centre, Royal Adelaide Hospital, Australia
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Wade AD, Nelson AJ, Garvin GJ. A synthetic radiological study of brain treatment in ancient Egyptian mummies. HOMO 2011; 62:248-69. [DOI: 10.1016/j.jchb.2011.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 01/16/2011] [Indexed: 10/18/2022]
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Cho BI, Engelhorn K, Correa AA, Ogitsu T, Weber CP, Lee HJ, Feng J, Ni PA, Ping Y, Nelson AJ, Prendergast D, Lee RW, Falcone RW, Heimann PA. Electronic structure of warm dense copper studied by ultrafast x-ray absorption spectroscopy. Phys Rev Lett 2011; 106:167601. [PMID: 21599412 DOI: 10.1103/physrevlett.106.167601] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 02/21/2011] [Indexed: 05/30/2023]
Abstract
We use time-resolved x-ray absorption spectroscopy to investigate the unoccupied electronic density of states of warm dense copper that is produced isochorically through the absorption of an ultrafast optical pulse. The temperature of the superheated electron-hole plasma, which ranges from 4000 to 10 000 K, was determined by comparing the measured x-ray absorption spectrum with a simulation. The electronic structure of warm dense copper is adequately described with the high temperature electronic density of state calculated by the density functional theory. The dynamics of the electron temperature is consistent with a two-temperature model, while a temperature-dependent electron-phonon coupling parameter is necessary.
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Affiliation(s)
- B I Cho
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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