Novel insights into the marine phase and river fidelity of anadromous twaite shad Alosa fallax in the UK and Ireland     

Peter Davies  Robert J. Britton  Andrew D. Nunn  Jamie R. Dodd  Charles Crundwell  Randolph Velterop  Niall &#x;Maoilidigh  Ross O'Neill  Emma V. Sheehan  Thomas Stamp  Jonathan D. Bolland 《水产资源保护:海洋与淡水生态系统》2020,30(7):1291-1298

1. Most research on anadromous fishes has been invested in their freshwater life‐phases, resulting in a relatively sparse understanding of their spatial ecology during marine life‐phases. However, understanding the marine dispersal of anadromous fishes is essential to identify threats and to implement conservation measures that fully encompass their lifecycle.
2. The twaite shad Alosa fallax is an anadromous fish increasingly imperilled across its range due to pollution, harvesting, and impediments to freshwater migration, but little is known about its distribution and movements during its marine life‐phase. Here, the application of acoustic telemetry provided novel insights into the coastal dispersal of twaite shad in the UK and Ireland during 2018–2019, and the freshwater entry of individuals during the 2019 spawning season.
3. Of 73 twaite shad acoustic‐tagged during their upstream migration in the River Severn in May 2018, 58 emigrated from the river. Twelve were subsequently detected 200 km to the south‐west at the Taw–Torridge Estuary between July 2018 and April 2019, where estuarine movements up to 5.8 km inland occurred in summer, winter, and spring. One was subsequently detected in the Munster Blackwater Estuary (Ireland) and then in the River Severn, indicating a minimum movement distance of 950 km. Thirty‐four (59%) of the emigrating individuals from 2018 re‐entered fresh water in the rivers Severn (n = 33) and Wye (n = 2) in April and May 2019.
4. These results suggest year‐round use of estuarine and nearshore habitats by at least a subset of the twaite shad population during their marine phase, providing evidence of potential range overlap between populations that spawn in different areas in the UK and Ireland, which may be facilitated by substantial dispersal. The results also highlight the potential of telemetry for estimating freshwater and marine mortality, and the benefits of sharing detection data across networks.

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A Biomechanical Comparison of Headless Tapered Variable Pitch and AO Cortical Bone Screws for Fixation of a Simulated Lateral Condylar Fracture in Equine Third Metacarpal Bones     

Larry D. Galuppo  DVM  Diplomate ACVS    Susan M. Stover  DVM  PhD  Diplomate ACVS    David G. Jensen  BS    Neil H. Willits  PhD 《Veterinary surgery : VS》2001,30(4):332-340

OBJECTIVE: To compare drilling, tapping, and screw-insertion torque, force, and time for the 4.5-mm AO and 6.5-mm Acutrak Plus (AP) bone screws, and to compare the mechanical shear strength and stiffness of a simulated complete lateral condylar fracture of the equine third metacarpal bone (MC3) stabilized with either an AO or AP screw. STUDY DESIGN: In vitro biomechanical assessment of screw-insertion variables, and shear failure tests of a bone-screw-stabilized simulated lateral condylar fracture. SAMPLE POPULATION: Eight pairs of cadaveric equine MC3s METHODS: Metacarpi were placed in a fixture and centered on a biaxial load cell in a materials-testing system to measure torque, compressive force, and time for drilling, tapping, and screw insertion. Standardized simulated lateral condylar fractures were stabilized by either an AO or AP screw and tested in shear until failure. A paired t test was used to assess differences between screws, with significance set at P < .05. RESULTS: Insertion and mechanical shear testing variables were comparable for AO and AP insertion equipment and screws. CONCLUSION: The 6.5-mm tapered AP screw can be inserted in equine third metacarpal condyles and is mechanically comparable with the 4.5-mm AO screw for fixation of a simulated lateral condylar fracture. CLINICAL RELEVANCE: Considering the comparable mechanical behavior, the potential for less-persistent soft-tissue irritation with the headless design, and the ability to achieve interfragmentary compression by inserting the screw in one hole drilled perpendicular to the fracture plane, the 6.5-mm tapered AP screw may be an attractive alternative for repair of incomplete lateral condylar fractures in horses.  相似文献   

APPLICATION OF THE PIN-HOLE COLLIMATOR IN SMALL ANIMAL NUCLEAR SCINTIGRAPHY: A REVIEW   总被引：1，自引：0，他引：1  

Karen  Young  BS  Gfregotry B.  Daniel  DVM MS  Anne  Bahr  DVM 《Veterinary radiology & ultrasound》1997,38(2):83-93

The pin-hole collimator is used to improve spatial resolution and magnify areas of interest. The pin-hole collimator has many applications in small animal veterinary scintigraphy. The principles of image formation for the pin-hole and parallel hole collimators are reviewed. The effects of distance on resolution and sensitivity are presented for the pin-hole and parallel hole collimators. Specific application of the pin-hole and parallel hole collimators. Specific application of the pin-hole collimator in veternary scintigraphy are discussed.  相似文献   

Epoxy Putty for Free-Form External Skeletal Fixators     

SIMON C. ROE BVSC  PhD  Dipiomate ACVS  THEARAYOUK KEO BS 《Veterinary surgery : VS》1997,26(6):472-477

Objective —To evaluate the suitability of epoxy putty for use as a connecting beam material in a free-form external skeletal fixator.
Design —Mechanical evaluation of beams and the pin-material interface of commonly used methacrylates and the proposed epoxy putty.
Procedure —The apparent modulus, bending strength, and toughness of 10 beams of three methacrylates (Technovit, APEF System, Bone Cement) and three epoxy putties (Oatey Epoxy Putty, All-Metals PowerPoxy, and Plumber's PowerPoxy) were determined in three-point bending. The shear strength of smooth and roughened-shaft pins embedded in the three methacrylates and the Oatey Epoxy Putty was determined by pull-out testing.
Results —The epoxy putties had similar strength, greater apparent modulus, and reduced toughness when compared with the methacrylates. The shear strength of the smooth pin interface with the Oatey Epoxy putty was greater than that with the methacrylates. The interface with roughened pins was much stronger than that with smooth pins for all materials tested.
Clinical Relevance —Epoxy putty is a suitable material for free-form external fixators. It is easy to handle, inexpensive, and has suitable setting times and mechanical properties.  相似文献   

Detection of Bacteria in Equine Synovial Fluid by Use of the Polymerase Chain Reaction   总被引：1，自引：0，他引：1  

M.R. CRABILL DVM    N.D. COHEN VMD  PhD  Diplomate ACVIM    L.J. MARTIN BS    R.B. SIMPSON DVM  MS  N. BURNEY MS 《Veterinary surgery : VS》1996,25(3):195-198

Equine synovial fluid aliquots were inoculated with Salmonella enteritidis, Escherichia coli, Actinobacillus equuli, Staphylococcus aureus , and Streptococcus zooepidemicus to obtain approximate concentrations of 1000, 100, 10, and 1 colony forming U/mL. Synovial fluid aliquots were also inoculated with an unquantitated inoculum of Bacteroides fragilis and Clostridium perfringens. Inoculated synovial fluid was incubated in trypticase-soy broth or Columbia broth for approximately 12 hours. Then aliquots were removed for DNA extraction and polymerase chain reaction (PCR) analysis for detection of a 531 base-pair segment of bacterial DNA corresponding to a region of the 16S ribosomal gene. Duplicate samples of inoculated synovial fluid were prepared for microbial culture. Bacteria were detected in all samples inoculated with bacteria but not in control synovial fluid samples. Under experimental conditions there was no difference between microbial culture and PCR analyses for detection of bacteria. Experimentally, PCR was able to detect bacteria in synovial fluid within 24 hours of inoculation.  相似文献   

Flavonoids from Theobroma cacao down-regulate inflammatory mediators     

Ramiro E  Franch A  Castellote C  Pérez-Cano F  Permanyer J  Izquierdo-Pulido M  Castell M 《Journal of agricultural and food chemistry》2005,53(22):8506-8511

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Quantitative extraction of macro-invertebrates from temperate and tropical leaf litter and soil: efficiency and time-dependent taxonomic biases of the Winkler extraction   总被引：2，自引：0，他引：2  

Frank-Thorsten Krell  Arthur Y.C. Chung  Emma DeBoise  Paul Eggleton  Alessandro Giusti  Kelly Inward  Sylvia Krell-Westerwalbesloh 《Pedobiologia》2005,49(2):175-186

Winkler extractors, a simple device presumed to extract macro-invertebrates efficiently from soil and litter samples, is being used increasingly in ecological surveys and functional studies of soil macro-invertebrate communities. In this study the extraction efficiency and taxonomic bias of the Winkler extraction are evaluated for extraction periods of 3 h up to 7 weeks, calibrated by hand-sorting after 7 weeks. The method extracts most macro-invertebrates completely or to a proportion of over 90% except Isopoda, Diplopoda and Mollusca. However, for an exhaustive result, a long extraction period of several weeks is necessary. For the most speciose group (adult beetles) and for the commonly most abundant group (ants), a short extraction of 3 days was sufficient to get 70% of the individuals and nearly all species. Three days was also sufficient to recover the rank abundance order of beetle families, while for ‘higher taxa’ and for Chilopoda species, 4 and 3 weeks were necessary, respectively. Optimum extraction times for the abundant macro-invertebrate groups and possible adjustment factors for the soil macro-invertebrates of temperate woodlands are proposed to compensate the taxonomic bias caused by short extraction periods. However, for recording an accurate snapshot of the soil and litter fauna at a particular time, shorter extraction periods are advisable because of the short life cycle of many soil invertebrates causing emergence of later stages or a second generation during longer extraction periods. The problem of contamination of samples is also discussed.  相似文献   

A molecular phylogeny for bats illuminates biogeography and the fossil record     

Teeling EC  Springer MS  Madsen O  Bates P  O'brien SJ  Murphy WJ 《Science (New York, N.Y.)》2005,307(5709):580-584

Bats make up more than 20% of extant mammals, yet their evolutionary history is largely unknown because of a limited fossil record and conflicting or incomplete phylogenies. Here, we present a highly resolved molecular phylogeny for all extant bat families. Our results support the hypothesis that megabats are nested among four major microbat lineages, which originated in the early Eocene [52 to 50 million years ago (Mya)], coincident with a significant global rise in temperature, increase in plant diversity and abundance, and the zenith of Tertiary insect diversity. Our data suggest that bats originated in Laurasia, possibly in North America, and that three of the major microbat lineages are Laurasian in origin, whereas the fourth is Gondwanan. Combining principles of ghost lineage analysis with molecular divergence dates, we estimate that the bat fossil record underestimates (unrepresented basal branch length, UBBL) first occurrences by, on average, 73% and that the sum of missing fossil history is 61%.  相似文献   

The unusual nature of recent snowpack declines in the North American cordillera     

Pederson GT  Gray ST  Woodhouse CA  Betancourt JL  Fagre DB  Littell JS  Watson E  Luckman BH  Graumlich LJ 《Science (New York, N.Y.)》2011,333(6040):332-335

In western North America, snowpack has declined in recent decades, and further losses are projected through the 21st century. Here, we evaluate the uniqueness of recent declines using snowpack reconstructions from 66 tree-ring chronologies in key runoff-generating areas of the Colorado, Columbia, and Missouri River drainages. Over the past millennium, late 20th century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains and in their north-south synchrony across the cordillera. Both the snowpack declines and their synchrony result from unparalleled springtime warming that is due to positive reinforcement of the anthropogenic warming by decadal variability. The increasing role of warming on large-scale snowpack variability and trends foreshadows fundamental impacts on streamflow and water supplies across the western United States.  相似文献   

Hydroxylysyl pyridinoline cross-link concentration affects the textural properties of fresh and smoked Atlantic salmon (Salmo salar L.) flesh     

Li X  Bickerdike R  Lindsay E  Campbell P  Nickell D  Dingwall A  Johnston IA 《Journal of agricultural and food chemistry》2005,53(17):6844-6850

A simple HPLC method is presented to quantify the low concentration of hydroxylysyl pyridinoline (PYD) cross-links in Atlantic salmon (Salmo salar L.) muscle. The method involved the extraction of tissue with NaOH prior to hydrolysis, which greatly reduced the amount of protein to be hydrolyzed and made downstream operations easier and more reproducible. The concentration of PYD was 426 pmol g(-)(1) dry mass muscle in post-rigor muscle stored at 0 degrees C and sampled 3 d after death. Hydroxproline (HYP) concentration was determined following NaOH extraction as a measure of collagen content. In post-rigor samples, the alkaline-insoluble HYP fraction comprised 18.3% of the total HYP. Scanning electron microscopy revealed shrinkage of muscle fibers and a retraction of the connective tissue matrix in smoked salmon. PYD concentration was relatively resistant to processing to the smoked product, decreasing by around 11.7%, as compared to a 22.2% decrease in HYP. There was a positive correlation between PYD concentration and the firmness of post-rigor muscle samples as measured by an instrumental texture analyzer, explaining 25% of the total variation. A weaker but still significant correlation was found between PYD concentration and firmness in the smoked product. There was no relationship between fillet firmness and total collagen concentration, although the correlation with HYP in the alkaline-insoluble fraction was significant at the 6% level (P = 0.057). Our results indicate that only 1-3% of collagen molecules are linked by nonreducible mature cross-links in harvest size farmed Atlantic salmon and that PYD concentration is an important raw material characteristic for flesh quality.  相似文献