395 research outputs found
Status of the tilefish, Lopholatilus chamaeleonticeps, fishery off South Carolina and Georgia and recommendations for management
We used a sex- and age-structured model and CPUE data from commercial and research vessels to assess the current status of the tilefish, Loplwlatilus chamaeleonticeps, substock off South Carolina and Georgia. Based on commercial CPUE data and assumed natural mortality (M) rates of 0.10-0.25, we estimated
that adult population density prior to fishing ranged from 603 to 950 per km2 and stock biomass ranged from 1,130 to 1,570 tonnes (t). Our estimates of the recommended fishing mortality rate ranged from 0.10 eM - 0.10) to 0.48 (M = 0.25), resulting in sustainable yields of 40 (M - 0.10) to 82 t eM = 0.25) per year. We obtained higher estimates of virgin population density (883-1,710 per km~ when research
CPUE data were used. Sustained yield estimates also were higher, ranging from 55 (M - 0.10) to 148 t (M = 0.25) per year. Average estimates of recommended yield from commercial and research CPUE data were 58 and 95 t, respectively. Observed yields in the developing fishery exceeded 100 t in 1981-84 and in 1986; however, current observations indicate that fishing effort has declined to a low level in response to reduced catches. Based on the assumption that commercial CPUE data better reflect population trends, we recommend that the annual harvest not exceed about 50 t, which should result in a stock biomass of about 400-800 t. Apparent limitations on sustainable yield from the fishery probably can be attributed to the long lifespan, slow growth rate, and sedentary nature of tilefish
Fitness of interspecific hybrids in the genus Cyprinella: An evaluation of swimming performance in stream fishes
As the result of anthropogenic disturbance, freshwater ecosystems are rapidly being destroyed worldwide. Accordingly, such impacts are also resulting in the loss of aquatic biodiversity. Specifically, the introduction of non-native aquatic species is becoming an increasing concern. Historically, many non-native freshwater fish introductions have been the result of commercial baitfish aquaculture and private aquarium release. Cyprinella lutrensis (the red shiner) is endemic to much of the central U.S., and its natural range does not extent east of the Mississippi River. Since the 1950âs, red shiner have been cultivated and transported across the globe as both bait and aquarium fish. During the early 1990âs, invasive red shiner populations were first observed in the Coosa River Basin, located in northwest Georgia, USA. Originating from bait bucket releases, invasive red shiner have quickly established in this area, and readily compete and hybridize with at least one native species of Cyprinella (Cyprinella venusta), the blacktail shiner. Over the past thirty years, red x blacktail shiner hybrids are becoming more abundant and demonstrate an uncertain level of viability. To date, little is known about the relative fitness of red x blacktail shiner hybrids compared to parental species. If hybrids exhibit a higher level of fitness compared to parental species, then this could result in regional extinctions of native stream fishes. To better understand the relative fitness of native blacktail shiner vs. hybrid shiner, we examined swimming performance as a widely accepted proxy. Blacktail, red, and hybrid shiner were collected in Northwest Georgia during the time frame of August 2020- March 2021. Individual swimming performance trials were then conducted in a recirculating flow chamber. During these trials, a suite of physiological and morphometric measurements were recorded. Here, we present an analysis of our preliminary data, investigating differences in fitness among native and hybrid shiner
Stellar Lyman-alpha Emission Lines in the Hubble Space Telescope Archive: Intrinsic Line Fluxes and Absorption from the Heliosphere and Astrospheres
We search the Hubble Space Telescope (HST) archive for previously unanalyzed
observations of stellar H I Lyman-alpha emission lines, our primary purpose
being to look for new detections of Lyman-alpha absorption from the outer
heliosphere, and to also search for analogous absorption from the astrospheres
surrounding the observed stars. The astrospheric absorption is of particular
interest because it can be used to study solar-like stellar winds that are
otherwise undetectable. We find and analyze 33 HST Lyman-alpha spectra in the
archive. All the spectra were taken with the E140M grating of the Space
Telescope Imaging Spectrograph (STIS) instrument on board HST. The HST/STIS
spectra yield 4 new detections of heliospheric absorption (70 Oph, Xi Boo, 61
Vir, and HD 165185) and 7 new detections of astrospheric absorption (EV Lac, 70
Oph, Xi Boo, 61 Vir, Delta Eri, HD 128987, and DK UMa), doubling the previous
number of heliospheric and astrospheric detections. When combined with previous
results, 10 of 17 lines of sight within 10 pc yield detections of astrospheric
absorption. This high detection fraction implies that most of the ISM within 10
pc must be at least partially neutral, since the presence of H I within the ISM
surrounding the observed star is necessary for an astrospheric detection. In
contrast, the detection percentage is only 9.7% (3 out of 31) for stars beyond
10 pc. Our Lyman-alpha analyses provide measurements of ISM H I and D I column
densities for all 33 lines of sight, and we discuss some implications of these
results. Finally, we measure chromospheric Lyman-alpha fluxes from the observed
stars. We use these fluxes to determine how Lyman-alpha flux correlates with
coronal X-ray and chromospheric Mg II emission, and we also study how
Lyman-alpha emission depends on stellar rotation.Comment: 56 pages, 15 figures; AASTEX v5.0 plus EPSF extensions in mkfig.sty;
accepted by ApJ
Networking research in front ending and intelligent terminals : H6000 software specifications
"CCTC-WAD document no. 7501.""Prepared for the Command and Control Technical Center, WWMCCS ADP Directorate, Defense Communications Agency, Washington, D. C."Bibliography: leaf 26
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BioTIME: A database of biodiversity time series for the Anthropocene.
MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL
Perceptions of HIV cure research among people living with HIV in Australia
Participation in HIV cure-related clinical trials that involve antiretroviral treatment (ART) interruption may pose substantial individual risks for people living with HIV (PLHIV) without any therapeutic benefit. As such, it is important that the views of PLHIV are considered in the design of HIV cure research trials. Examining the lived experience of PLHIV provides unique and valuable perspectives on the risks and benefits of HIV cure research. In this study, we interviewed 20 PLHIV in Australia about their knowledge and attitudes toward clinical HIV cure research and explored their views regarding participation in HIV cure clinical trials, including those that involve ART interruption. Data were analysed thematically, using both inductive and deductive coding techniques, to identity themes related to perceptions of HIV cure research and PLHIVâs assessment of the possible risks and benefits of trial participation. Study findings revealed interviewees were willing to consider participation in HIV cure research for social reasons, most notably the opportunity to help others. Concerns raised about ART interruption related to the social and emotional impact of viral rebound, including fear of onward HIV transmission and anxiety about losing control. These findings reveal the ways in which PLHIV perspectives deepen our understanding of HIV cure research, moving beyond a purely clinical assessment of risks and benefits in order to consider the social context
Preferential binding to elk-1 by sle-associated il10 risk allele upregulates il10 expression
Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7Ă10â8, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans
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