993 research outputs found
It’s raining sturgeons: a likely occurrence of avian predation or scavenging of Atlantic Sturgeon (Acipenser oxyrinchus Mitchell, 1815)
Predation on the federally-endangered Atlantic Sturgeon (Acipenser oxyrinchus), and sturgeons generally is understudied. Most predation is presumed to occur on eggs and larvae, and bethe result of interactions with other aquatic organisms, primarily other fishes. Predation on larger juvenile sturgeon by terrestrial and avian predators remains largely unknown. Here we document the recovery of a juvenile Atlantic Sturgeon carcass (512 mm total length) approximately 120 m inland from the shore of the York River in Gloucester County, Virginia. This individual showed signs of predation by a bird of prey, most likely an Osprey (Pandion haliaetus), although a Bald Eagle (Haliaeetus leucocephalus) cannot be ruled out, as they are also residents in this area. The purpose of this note is to document this occurrence and suggest further study of predation on Atlantic Sturgeon in the Chesapeake Bay
Temperature selectivity and movement patterns of speckled trout
Speckled trout (Cynoscion nebulosus) is the focus of an important recreational fishery in the southeastern United States. Speckled trout in Virginia has been cited as both a transitional population and as a mostly non-migratory population. The degree of residency is important to understand for the effective management of the species. Management of speckled trout has also been marred by cold-stun events which can kill a significant portion of the stock and have detrimental localized effects. Virginia is the northern extent of speckled trout populations and is the most likely portion of its range to experience cold-stun events. Virginia water temperatures can reach 0 °C during some winters, well below lethal temperatures for speckled trout. The primary objective of this project was to provide managers and recreational fishermen with information regarding speckled trout movements. more..
Trends, microbiology, and outcomes of infective endocarditis in children during 2000–2010 in the United States
BackgroundWe studied the incidence, trend, underlying conditions, microbiology, and outcomes of infective endocarditis (IE) in children during 11 years using Nationwide Inpatient Sample (NIS) database. This is the largest all‐payer inpatient care database in the United States containing data for more than 8 million hospital stays from over 1000 hospitals.MethodsNIS data from 2000 to 2010 of primary discharge diagnosis of IE in children aged ≤19 years old were studied. Children with underlying congenital heart defects and acquired heart conditions were identified. Microbiological causative agents were recorded. Linear regression was used to assess trend of incidence over time.ResultsAn estimated 3,840 (95% CI: 3,395‐4,285) children had a discharge diagnosis of IE. The overall incidence was 0.43 per 100 000 children. The incidence was stable over the study period (P = .4 for trend). The majority of patients 56.2% were ≥11 years old and 15.4% were ≤ 1 year. Underlying cardiac conditions were present in 53.5% of patients. Overall 30.2% of cases were culture‐negative. Among those with identified pathogens, Staphylococcus species were most common (43.1%) followed by Streptococcus species (39.5%). Viridans Streptococcus group was most common in those with underlying heart disease (32.7%) and S. aureus was most common in those without heart disease (46.9%). Among culture‐positive patients, there was a decline in proportion of Staphylococcal IE (P = .03) and an increase in proportion of Streptococcal IE (P = .04). Overall mortality was 2.8%. Patients with Staphylococcal IE had longer median length of stay (12 vs. 9 days; P < .01) and the highest mortality (4.7%).ConclusionThe incidence of IE in children has remained unchanged in the United States during the 11‐year study period. Among culture‐positive patients there was a significant decrease in Staphylococcal IE and a significant increase of Streptococcal IE. Staphylococcal IE was associated with increased LOS and highest mortality.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136489/1/chd12425_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136489/2/chd12425.pd
Seasonal Distributions and Movements of Longnose Gar (Lepisosteus osseus) within the York River System, Virginia
The seasonal movements of Lepisosteus osseus (Longnose Gar) are largely unknown. The goal of this project was to characterize spawning movements and seasonal distributions by using acoustic tagging methods and examining historical catch records from a trawl survey. This is the first time that movements have been studied for an estuarine population of Longnose Gar. Two individuals moved greater minimum distances (69 and 74 km) than found in the only other report on movement in this species. Spawning-ground residency time, collected from two tagged Longnose Gar, was approximately one month, and tidal periodicity was observed for one of the two fish. Data from a fisheries independent trawl survey were used to examine seasonal catch distributions in Longnose Gar and represents the first report of winter distributions for this species. Winter locations occurred both alongshore and mid-channel, and the distributions were similar to those in the summer and fal
Patterns of Hatchery-Produced Returns of American Shad in the James River, Virginia
American Shad Alosa sapidissima is an anadromous clupeid that once supported a robust fishery but has declined drastically throughout its native range due to overfishing, dam proliferation, and poor water quality. A hatchery program on the James River in Virginia was introduced in 1992 to support the recovery of stocks. Following a moratorium of the fishery enacted in 1994, a fisheries-independent survey was initiated in 1998 to monitor the population recovery efforts and status of American Shad stocks in Virginia. This paper examined 22 years of monitoring data for the James River and determined the effect of hatchery inputs on the James River stock of American Shad. The spawning stock index increased from 2.57 in 1998 to a peak of 9.33 in 2003 but has generally been declining since and has been at very low levels in most recent years. The hatchery prevalence for female American Shad (i.e., the percentage of fish derived from the hatchery) ranged between 3.6% and 60.5%. Years with higher spawning stock index values were significantly correlated to higher percentages of hatchery fish returning to spawn. The stock–recruitment relationship was best explained by the Ricker model, which had the lowest residual standard error and Akaike information criterion value. A threshold level of hatchery-released individuals (approximately 4 million larvae) was necessary to achieve the highest numbers of returning spawners, but stocking above 7 million larvae correlated with declining returns. Long-term monitoring of the James River American Shad spawning population allowed for the critical examination of the contribution of hatchery individuals to the yearly spawning run and the relative success rate of each hatchery year-class. From these data, we consider that the James River spawning stock of American Shad was dependent upon hatchery inputs, with ideal hatchery returns occurring during years of moderate levels of hatchery stocking
Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2021 Annual Report
This report describes the results of the twenty-fourth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2021, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007, ASMFC 2020).
We also report on two fishery independent monitoring programs using anchor gillnets in the Rappahannock River (year 4) and the Chickahominy River (year 7; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis).
Further, we report on the year 6 of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and present an index of juvenile abundance from this survey. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries
Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2022 Annual Report
This report describes the results of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2022, evaluating hatchery programs and contributing to coast-wide assessments (ASMFC 2007a; ASMFC 2020). We also report on a fishery-independent monitoring program to determine abundance and stock structure of river herring (A. pseudoharengus, and A. aestivalis) in Virginia by evaluating the adult spawning runs in the Chickahominy River, a major tributary of the James River, and the Rappahannock River. Further, a recently added objective of this study was to complement the monitoring of the adult spawning population of American shad and river herring in the James River system by monitoring juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gillnet fishery and American shad and river herring in pound net fisheries
Monitoring the Abundance of American Shad and River Herring in Virginia’s Rivers 2020 Annual Report
This report describes the results of the twenty-third year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2020, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007, ASMFC 2020).
We also report on two fisheryindependent monitoring programs using anchor gillnets in the Rappahannock River (year 3) and the Chickahominy River (year 6; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis).
Further, we report on the year 5 of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and present an index of juvenile abundance from this survey. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries
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A monoclonal antibody against lymphocyte function-associated antigen-1 decreases HIV-1 replication by inducing the secretion of an antiviral soluble factor
Background: Lymphocyte Function-Associated Antigen-1 (LFA-1) likely plays a role in the pathogenesis of against HIV-1 and is known to facilitate cell-to-cell transmission of the virus. A monoclonal antibody specific for LFA-1 (Cytolin®) was evaluated as a potential therapeutic in pilot studies performed in the mid-1990s. These uncontrolled human studies suggested that administration of this anti-LFA-1 antibody to HIV-1 infected individuals could provide a modest benefit by decreasing circulating HIV-1 RNA and increasing CD4+ T cell counts. At the time, it was proposed that when bound to cytolytic T cells, the antibody inhibited lysis of activated CD4+ T cells. Given the renewed interest in monoclonal antibody therapy for HIV-1 infected individuals, we investigated possible mechanisms of action of this antibody in vitro. Methods: To assess whether this anti-LFA-1 antibody binds to HIV-1, a virus capture assay was performed. Binding of the antibody to cells was assessed using flow cytometry. Inhibition of HIV-1 replication was determined in culture by measuring the amount of p24 produced by ELISA. After co-culture of the antibody with peripheral blood mononuclear cells, supernatants were assayed for cytokines and chemokines using various immunoassays. Results: Our experiments demonstrate that anti-LFA-1 antibody binds to CCR5 and CXCR4 utilizing strains of HIV-1. It also binds to CD8+ T cells and dendritic cells. When bound to virus prior to infection, there is no decrease in HIV-1 replication, suggesting it does not directly inhibit viral replication via virus binding. When bound to cells, it does not inhibit lysis of CD4+ T cells, as was originally hypothesized. Binding to cells does appear to induce the production of a soluble factor that inhibits HIV-1 replication. We determined that this soluble factor was not any of the cytokines or chemokines with known anti-HIV-1 activity. Further, the antibody does not appear to induce any common immune modulating cytokines or chemokines. Conclusions: These results suggest that one possible mechanism of action of this anti-LFA-1 antibody is to inhibit HIV-1 replication via the production of a soluble antiviral factor that is induced upon binding to cells
Monitoring the Abundance of American Shad and River Herring in Virginia\u27s Rivers - 2016 Annual Report
This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring programs using a drift gillnet (year 3) and anchor gillnets (year 2) to assess the status of the spawning run of river herring in the Chickahominy River, a major tributary of the James River. Further, we report on the second year of a monitoring program for juvenile alosines by using nighttime surface trawls in the Chickahominy River and calculate an index of juvenile abundance. Additional objectives were to monitor bycatch of American shad in a permitted gill-net fishery and American shad and river herring in pound-net fisheries
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