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Ellis AR, Duffy DA, Marko IP, Acharya S, Du W, Yu SQ, Sweeney SJ. Challenges for room temperature operation of electrically pumped GeSn lasers. Sci Rep 2024; 14:10318. [PMID: 38705884 DOI: 10.1038/s41598-024-60686-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/26/2024] [Indexed: 05/07/2024] Open
Abstract
Recent demonstrations of room-temperature lasing in optically pumped GeSn show promise for future CMOS compatible lasers for Si-photonics applications. However, challenges remain for electrically pumped devices. Investigation of the processes that limit device performance is therefore vital in aiding the production of future commercial devices. In this work, a combined experimental and modelling approach is utilised to explore the dominant loss processes in current devices. By manipulating the band structure of functioning devices using high hydrostatic pressure techniques at low temperature, the dominant carrier recombination pathways are identified. This reveals that 93± 5% of the threshold current is attributable to defect-related recombination at a temperature, T = 85 K. Furthermore, carrier occupation of L-valley states (carrier leakage) is responsible for 1.1± 0.3% of the threshold current, but this sharply increases to 50% with a decrease of just 30 meV in the L- Γ separation energy. This indicates that thermal broadening of a similar order may reproduce these adverse effects, limiting device performance at higher temperatures. Temperature dependent calculations show that carrier occupation of indirect valley L-states strongly affects the transparency carrier density and is therefore very sensitive to the Sn composition, leading to an effective operational temperature range for given Sn compositions and strain values. Recommendations for future device designs are proposed based on band structure and growth optimisations.
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Affiliation(s)
- A R Ellis
- James Watt School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - D A Duffy
- James Watt School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - I P Marko
- James Watt School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - S Acharya
- Material Science and Engineering Program, University of Arkansas, Fayetteville, AR, 72701, USA
- Department of Electrical Engineering and Computer Science, University of Arkansas, Fayetteville, AR, 72701, USA
| | - W Du
- Department of Electrical Engineering and Computer Science, University of Arkansas, Fayetteville, AR, 72701, USA
- Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - S Q- Yu
- Department of Electrical Engineering and Computer Science, University of Arkansas, Fayetteville, AR, 72701, USA
- Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - S J Sweeney
- James Watt School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK.
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Smith JB, Keiter DA, Sweeney SJ, Miller RS, Schlichting PE, Beasley JC. Habitat quality influences trade-offs in animal movement along the exploration-exploitation continuum. Sci Rep 2023; 13:4814. [PMID: 36964167 PMCID: PMC10039022 DOI: 10.1038/s41598-023-31457-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 03/13/2023] [Indexed: 03/26/2023] Open
Abstract
To successfully establish itself in a novel environment, an animal must make an inherent trade-off between knowledge accumulation and exploitation of knowledge gained (i.e., the exploration-exploitation dilemma). To evaluate how habitat quality affects the spatio-temporal scale of switching between exploration and exploitation during home range establishment, we conducted experimental trials comparing resource selection and space-use of translocated animals to those of reference individuals using reciprocal translocations between habitat types of differing quality. We selected wild pigs (Sus scrofa) as a model species to investigate hypotheses related to the movement behavior of translocated individuals because they are globally distributed large mammals that are often translocated within their introduced range to facilitate recreational hunting. Individuals translocated to higher quality habitat (i.e. higher proportions of bottomland hardwood habitats) exhibited smaller exploratory movements and began exploiting resources more quickly than those introduced to lower quality areas, although those in lower-quality areas demonstrated an increased rate of selection for preferred habitat as they gained knowledge of the landscape. Our data demonstrate that habitat quality mediates the spatial and temporal scale at which animals respond behaviorally to novel environments, and how these processes may determine the success of population establishment.
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Affiliation(s)
- Joshua B Smith
- Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E., Aiken, SC, 29802, USA
- Oregon Department of Fish and Wildlife, 1401 Gekeler Ln, La Grande, OR, 97850, USA
| | - David A Keiter
- Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E., Aiken, SC, 29802, USA
- D.B. Warnell School of Forestry and Natural Resources, University of Georgia, 180 East Green St., Athens, GA, 30602, USA
| | - Steven J Sweeney
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, 2150 Centre Avenue, Fort Collins, CO, 80526, USA
| | - Ryan S Miller
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, 2150 Centre Avenue, Fort Collins, CO, 80526, USA
| | - Peter E Schlichting
- Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E., Aiken, SC, 29802, USA
| | - James C Beasley
- Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E., Aiken, SC, 29802, USA.
- D.B. Warnell School of Forestry and Natural Resources, University of Georgia, 180 East Green St., Athens, GA, 30602, USA.
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Register KB, Parker M, Patyk KA, Sweeney SJ, Boatwright WD, Jones LC, Woodbury M, Hunter DL, Treanor J, Kohr M, Hamilton RG, Shury TK, Nol P. Serological evidence for historical and present-day exposure of North American bison to Mycoplasma bovis. BMC Vet Res 2021; 17:18. [PMID: 33413373 PMCID: PMC7791819 DOI: 10.1186/s12917-020-02717-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/09/2020] [Indexed: 11/12/2022] Open
Abstract
Background Mycoplasma bovis causes mastitis, otitis, pneumonia and arthritis in cattle and is a major contributor to bovine respiratory disease complex. Around the year 2000, it emerged as a significant threat to the health of North American bison. Whether healthy bison are carriers of M. bovis and when they were first exposed is not known. To investigate these questions we used a commercially available ELISA that detects antibodies to M. bovis to test 3295 sera collected from 1984 through 2019 from bison in the United States and Canada. Results We identified moderately to strongly seropositive bison from as long ago as the late 1980s. Average seroprevalence over the past 36 years is similar in the United States and Canada, but country-specific differences are evident when data are sorted by the era of collection. Seroprevalence in the United States during the pre-disease era (1999 and prior) was significantly higher than in Canada, but was significantly lower than in Canada during the years 2000–2019. Considering individual countries, seroprevalence in the United States since the year 2000 dropped significantly as compared to the years 1985–1999. In Canada the trend is reversed, with seroprevalence increasing significantly since the year 2000. ELISA scores for sera collected from free-ranging bison do not differ significantly from scores for sera from more intensively managed animals, regardless of the era in which they were collected. However, seroprevalence among intensively raised Canadian bison has nearly doubled since the year 2000 and average ELISA scores rose significantly. Conclusions Our data provide the first evidence that North American bison were exposed to M. bovis many years prior to the emergence of M. bovis-related disease. Patterns of exposure inferred from these results differ in the United States and Canada, depending on the era under consideration. Our data further suggest that M. bovis may colonize healthy bison at a level sufficient to trigger antibody responses but without causing overt disease. These findings provide novel insights as to the history of M. bovis in bison and will be of value in formulating strategies to minimize the impact of mycoplasmosis on bison health and production.
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Affiliation(s)
- Karen B Register
- Ruminant Diseases and Immunology Research Unit, USDA/Agricultural Research Service/National Animal Disease Center, Ames, IA, USA.
| | - Margaret Parker
- Center for Epidemiology and Animal Health, USDA:APHIS:Veterinary Services, Fort Collins, CO, USA
| | - Kelly A Patyk
- Center for Epidemiology and Animal Health, USDA:APHIS:Veterinary Services, Fort Collins, CO, USA
| | - Steven J Sweeney
- Center for Epidemiology and Animal Health, USDA:APHIS:Veterinary Services, Fort Collins, CO, USA
| | - William D Boatwright
- Ruminant Diseases and Immunology Research Unit, USDA/Agricultural Research Service/National Animal Disease Center, Ames, IA, USA
| | - Lee C Jones
- US Fish and Wildlife Service, Wildlife Health Office, Bozeman, MT, USA
| | - Murray Woodbury
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - John Treanor
- Yellowstone Center for Resources, Yellowstone National Park, WY, USA
| | - Marshall Kohr
- Animal Medical Center of Wyoming, LLC, Gillette, WY, USA
| | | | | | - Pauline Nol
- Wildlife Livestock Disease Investigations Team, USDA:APHIS:Veterinary Services, Fort Collins, CO, USA.,Present address: Colorado Division of Parks and Wildlife, Wildlife Health Program, Fort Collins, CO, USA
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McClure ML, Burdett CL, Farnsworth ML, Sweeney SJ, Miller RS. Publisher Correction: A globally-distributed alien invasive species poses risks to United States imperiled species. Sci Rep 2018; 8:11153. [PMID: 30026511 PMCID: PMC6053441 DOI: 10.1038/s41598-018-26014-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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Tabak MA, Norouzzadeh MS, Wolfson DW, Sweeney SJ, Vercauteren KC, Snow NP, Halseth JM, Di Salvo PA, Lewis JS, White MD, Teton B, Beasley JC, Schlichting PE, Boughton RK, Wight B, Newkirk ES, Ivan JS, Odell EA, Brook RK, Lukacs PM, Moeller AK, Mandeville EG, Clune J, Miller RS. Machine learning to classify animal species in camera trap images: Applications in ecology. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.13120] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael A. Tabak
- Center for Epidemiology and Animal Health United States Department of Agriculture Fort Collins Colorado
- Department of Zoology and Physiology University of Wyoming Laramie Wyoming
| | | | - David W. Wolfson
- Center for Epidemiology and Animal Health United States Department of Agriculture Fort Collins Colorado
| | - Steven J. Sweeney
- Center for Epidemiology and Animal Health United States Department of Agriculture Fort Collins Colorado
| | - Kurt C. Vercauteren
- National Wildlife Research Center United States Department of Agriculture Fort Collins Colorado
| | - Nathan P. Snow
- National Wildlife Research Center United States Department of Agriculture Fort Collins Colorado
| | - Joseph M. Halseth
- National Wildlife Research Center United States Department of Agriculture Fort Collins Colorado
| | - Paul A. Di Salvo
- Center for Epidemiology and Animal Health United States Department of Agriculture Fort Collins Colorado
| | - Jesse S. Lewis
- College of Integrative Sciences and Arts Arizona State University Mesa Arizona
| | | | - Ben Teton
- Tejon Ranch Conservancy Lebec California
| | - James C. Beasley
- Savannah River Ecology Laboratory Warnell School of Forestry and Natural Resources University of Georgia Aiken South Carolina
| | - Peter E. Schlichting
- Savannah River Ecology Laboratory Warnell School of Forestry and Natural Resources University of Georgia Aiken South Carolina
| | - Raoul K. Boughton
- Range Cattle Research and Education Center Wildlife Ecology and Conservation University of Florida Ona Florida
| | - Bethany Wight
- Range Cattle Research and Education Center Wildlife Ecology and Conservation University of Florida Ona Florida
| | | | | | | | - Ryan K. Brook
- Department of Animal and Poultry Science University of Saskatchewan Saskatoon SK Canada
| | - Paul M. Lukacs
- Wildlife Biology Program Department of Ecosystem and Conservation Sciences W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana
| | - Anna K. Moeller
- Wildlife Biology Program Department of Ecosystem and Conservation Sciences W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana
| | - Elizabeth G. Mandeville
- Department of Zoology and Physiology University of Wyoming Laramie Wyoming
- Department of Botany University of Wyoming Laramie Wyoming
| | - Jeff Clune
- Computer Science Department University of Wyoming Laramie Wyoming
| | - Ryan S. Miller
- Center for Epidemiology and Animal Health United States Department of Agriculture Fort Collins Colorado
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Miller RS, Sweeney SJ, Slootmaker C, Grear DA, Di Salvo PA, Kiser D, Shwiff SA. Cross-species transmission potential between wild pigs, livestock, poultry, wildlife, and humans: implications for disease risk management in North America. Sci Rep 2017; 7:7821. [PMID: 28798293 PMCID: PMC5552697 DOI: 10.1038/s41598-017-07336-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/28/2017] [Indexed: 01/21/2023] Open
Abstract
Cross-species disease transmission between wildlife, domestic animals and humans is an increasing threat to public and veterinary health. Wild pigs are increasingly a potential veterinary and public health threat. Here we investigate 84 pathogens and the host species most at risk for transmission with wild pigs using a network approach. We assess the risk to agricultural and human health by evaluating the status of these pathogens and the co-occurrence of wild pigs, agriculture and humans. We identified 34 (87%) OIE listed swine pathogens that cause clinical disease in livestock, poultry, wildlife, and humans. On average 73% of bacterial, 39% of viral, and 63% of parasitic pathogens caused clinical disease in other species. Non-porcine livestock in the family Bovidae shared the most pathogens with swine (82%). Only 49% of currently listed OIE domestic swine diseases had published wild pig surveillance studies. The co-occurrence of wild pigs and farms increased annually at a rate of 1.2% with as much as 57% of all farms and 77% of all agricultural animals co-occurring with wild pigs. The increasing co-occurrence of wild pigs with livestock and humans along with the large number of pathogens shared is a growing risk for cross-species transmission.
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Affiliation(s)
- Ryan S Miller
- Center for Epidemiology and Animal Health, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States.
| | - Steven J Sweeney
- Center for Epidemiology and Animal Health, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States
| | - Chris Slootmaker
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States
| | - Daniel A Grear
- National Wildlife Health Center, United States Geological Survey, Madison, Wisconsin, United States
| | - Paul A Di Salvo
- Center for Epidemiology and Animal Health, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States
| | - Deborah Kiser
- Center for Epidemiology and Animal Health, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States
| | - Stephanie A Shwiff
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, United States
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Abstract
Typical supercell approaches used to investigate the electronic properties of GaAs(1-x)Bi(x) produce highly accurate, but folded, band structures. Using a highly optimized algorithm, we unfold the band structure to an approximate [Formula: see text] relation associated with an effective Brillouin zone. The dispersion relations we generate correlate strongly with experimental results, confirming that a regime of band gap energy greater than the spin-orbit-splitting energy is reached at around 10% bismuth fraction. We also demonstrate the effectiveness of the unfolding algorithm throughout the Brillouin zone (BZ), which is key to enabling transition rate calculations, such as Auger recombination rates. Finally, we show the effect of disorder on the effective masses and identify approximate values for the effective mass of the conduction band and valence bands for bismuth concentrations from 0-12%.
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Affiliation(s)
- R Maspero
- Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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Miller RS, Sweeney SJ, Akkina JE, Saito EK. Potential Intercontinental Movement of Influenza A(H7N9) Virus into North America by Wild Birds: Application of a Rapid Assessment Framework. Transbound Emerg Dis 2014; 62:650-68. [PMID: 24589158 DOI: 10.1111/tbed.12213] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Indexed: 11/28/2022]
Abstract
A critical question surrounding emergence of novel strains of avian influenza viruses (AIV) is the ability for wild migratory birds to translocate a complete (unreassorted whole genome) AIV intercontinentally. Virus translocation via migratory birds is suspected in outbreaks of highly pathogenic strain A(H5N1) in Asia, Africa and Europe. As a result, the potential intercontinental translocation of newly emerging AIV such as A(H7N9) from Eurasia to North America via migratory movements of birds remains a concern. An estimated 2.91 million aquatic birds move annually between Eurasia and North America with an estimated AIV prevalence as high as 32.2%. Here, we present a rapid assessment to address the likelihood of whole (unreassorted)-genome translocation of Eurasian strain AIV into North America. The scope of this assessment was limited specifically to assess the weight of evidence to support the movement of an unreassorted AIV intercontinentally by migratory aquatic birds. We developed a rapid assessment framework to assess the potential for intercontinental movement of avian influenzas by aquatic birds. This framework was iteratively reviewed by a multidisciplinary panel of scientific experts until a consensus was established. Our assessment framework identified four factors that may contribute to the potential for introduction of any AIV intercontinentally into North America by wild aquatic birds. These factors, in aggregate, provide a framework for evaluating the likelihood of new forms of AIV from Eurasia to be introduced by aquatic birds into North America. Based on our assessment, we determined that the potential for introduction of A(H7N9) into North America through aquatic migratory birds is possible, but the likelihood ranges from extremely low to low.
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Affiliation(s)
- R S Miller
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, CO, USA
| | - S J Sweeney
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, CO, USA
| | - J E Akkina
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, CO, USA
| | - E K Saito
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health, Fort Collins, CO, USA
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Lever L, Hu Y, Myronov M, Liu X, Owens N, Gardes FY, Marko IP, Sweeney SJ, Ikonić Z, Leadley DR, Reed GT, Kelsall RW. Modulation of the absorption coefficient at 1.3 μm in Ge/SiGe multiple quantum well heterostructures on silicon. Opt Lett 2011; 36:4158-4160. [PMID: 22048350 DOI: 10.1364/ol.36.004158] [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: 05/31/2023]
Abstract
We report modulation of the absorption coefficient at 1.3 μm in Ge/SiGe multiple quantum well heterostructures on silicon via the quantum-confined Stark effect. Strain engineering was exploited to increase the direct optical bandgap in the Ge quantum wells. We grew 9 nm-thick Ge quantum wells on a relaxed Si0.22Ge0.78 buffer and a contrast in the absorption coefficient of a factor of greater than 3.2 was achieved in the spectral range 1290-1315 nm.
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Affiliation(s)
- L Lever
- Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
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Abstract
Eradication of Mycobacterium bovis relies on accurate detection of infected animals, including potential domestic and wildlife reservoirs. Available diagnostic tests lack the sensitivity and specificity necessary for accurate detection, particularly in infected wildlife populations. Recently, an in vitro diagnostic test for cattle which measures plasma interferon-gamma (IFN-gamma) levels in blood following in vitro incubation with M. bovis purified protein derivative has been enveloped. This test appears to have increased sensitivity over traditional testing. Unfortunately, it does not detect IFN-gamma from Cervidae. To begin to address this problem, the IFN-gamma gene from elk (Cervus elaphus) was cloned, sequenced, expressed, and characterized. cDNA was cloned from mitogen stimulated peripheral blood mononuclear cells. The predicted amino acid (aa) sequence was compared to known sequences from cattle, sheep, goats, red deer (Cervus elaphus), humans, and mice. Biological activity of the recombinant elk IFN-gamma (rElkIFN-gamma) was confirmed in a vesicular stomatitis virus cytopathic effect reduction assay. Production of monoclonal antibodies to IFN-gamma epitopes conserved between ruminant species could provide an important tool for the development of reliable, practical diagnostic assays for detection of a delayed type hypersensitivity response to a variety of persistent infectious agents in ruminants, including M. bovis and Brucella abortus. Moreover, development of these reagents will aid investigators in studies to explore immunological responses of elk that are associated with resistance to infectious diseases.
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Affiliation(s)
- S J Sweeney
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman 99164-7040, USA
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Sweeney SJ, Silflow RM, Foreyt WJ. Comparative leukotoxicities of Pasteurella haemolytica isolates from domestic sheep and free-ranging bighorn sheep (Ovis canadensis). J Wildl Dis 1994; 30:523-8. [PMID: 7760481 DOI: 10.7589/0090-3558-30.4.523] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Twenty-eight isolates of Pasteurella haemolytica from domestic sheep (n = 14 isolates) and bighorn sheep (n = 14 isolates) were evaluated for leucotoxicity against peripheral blood neutrophils of bighorn sheep by adding bacterial culture supernatants to bighorn sheep neutrophils in vitro. Leukotoxic isolates of P. haemolytica, defined as causing > 50% neutrophil death as measured by release of lactate dehydrogenase into culture supernatants, were identified from eight of 14 domestic sheep isolates and from 0 of 14 bighorn sheep isolates. The in vitro assay of isolates of P. haemolytica may provide a valid predictive measure of strain virulence of P. haemolytica, and of potential pneumonic episodes in bighorn sheep populations.
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Affiliation(s)
- S J Sweeney
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040
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