1,098 research outputs found

    Distribution of red deepsea crab (Chaceon quinquedens) by size and sex in the Gulf of Mexico

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    The red deepsea crab (Chaceon quinquedens (Smith, 1879)) has supported a commercial fishery off the coast of New England since the 1970s (Wigley et al., 1975) and has had annual harvests from 400 metric tons (t) (1996) to 4000 t (2001) (NEFMC, 2002). In 2002, a fishery management plan for the northeast fishery on the Atlantic coast was implemented and total allowable catch was reduced to approximately 2500 t (NEFMC, 2002). Although there are management plans for the golden crab (C. fenneri) and the red deep sea crab for Atlantic coast regions, there is no fishery management plan for red deepsea crabs in the Gulf of Mexico. Successful management for sustainable harvests should be based on a knowledge of the life history of the species, but C. quinquedens has been a difficult species for which to obtain life history and abundance information because of its deep distribution

    Spatial and Temporal Variations in Community Structure of the Demersal Macrofauna of a Subtropical Estuary (Louisiana).

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    Epibenthic (trawlable) macrofauna and hydrographic variables were sampled at ten stations in the Calcasieu estuary, Louisiana, from June, 1974, through February, 1976. The 100 otter trawl samples collected contained 32,221 individuals belonging to 63 invertebrate and 68 fish species. The 10 most abundant fish and invertebrate species represented 95.3 and 90.0%, respectively, of the total number of individuals collected. Seasonal variation in numbers of species and individuals were similar, with significant increases in number of species during spring and early summer months. Numerical classification was used to analyze spatial and temporal patterns of utilization of the estuary and to examine correlates of demographical variation and assemblage structure. Eight site groups and seven species groups were allocated by normal and inverse analyses, respectively. Four of the site groups were seasonally restricted, two were habitat restricted and two were both habitat and seasonally restricted. Nodal analyses identified patterns of constancy and fidelity, with spatial and temporal partitioning of the estuary by the species groups. Biotic interactions were implied by separation of congeners or closely related species into different species groups having separate centers of distribution. Diversity and evenness values, although not utile in assessing areal and seasonal patterns of fluctuations in assemblages, did delimit structural differences in closely related species groups. A relatively straight, deep ship channel extended the length of the estuary and had a dominant influence on hydrography by permitting intrusion of high salinity water. A salt water wedge, often with distinct haloclines and thermoclines, was observed at all channel stations. Salinities varied from 0.8 to 33.0(\u27o)/oo and temperature ranged from 9.5 to 32.7(DEGREES)C in the estuary over the duration of the study. Tidal movements and seasonal variations in river discharge rates caused large temporal variations in salinity and temperature at each station. Percent oxygen saturation of channel bottom waters was inversely related to the distance from the mouth of the estuary. Percent oxygen saturation of the channel during summer months was significantly lower than the rest of the year. Hypoxic conditions of deeper stations during warmer months resulted in defaunation

    Molecular Star Formation Rate Indicators in Galaxies

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    We derive a physical model for the observed relations between star formation rate (SFR) and molecular line (CO and HCN) emission in galaxies, and show how these observed relations are reflective of the underlying star formation law. We do this by combining 3D non-LTE radiative transfer calculations with hydrodynamic simulations of isolated disk galaxies and galaxy mergers. We demonstrate that the observed SFR-molecular line relations are driven by the relationship between molecular line emission and gas density, and anchored by the index of the underlying Schmidt law controlling the SFR in the galaxy. Lines with low critical densities (e.g. CO J=1-0) are typically thermalized and trace the gas density faithfully. In these cases, the SFR will be related to line luminosity with an index similar to the Schmidt law index. Lines with high critical densities greater than the mean density of most of the emitting clouds in a galaxy (e.g. CO J=3-2, HCN J=1-0) will have only a small amount of thermalized gas, and consequently a superlinear relationship between molecular line luminosity and mean gas density. This results in a SFR-line luminosity index less than the Schmidt index for high critical density tracers. One observational consequence of this is a significant redistribution of light from the small pockets of dense, thermalized gas to diffuse gas along the line of sight, and prodigious emission from subthermally excited gas. At the highest star formation rates, the SFR-Lmol slope tends to the Schmidt index, regardless of the molecular transition. The fundamental relation is the Kennicutt-Schmidt law, rather than the relation between SFR and molecular line luminosity. We use these results to make imminently testable predictions for the SFR-molecular line relations of unobserved transitions.Comment: ApJ Accepted - Results remain same as previous version. Content clarified with Referee's comment

    Propagating the missing bacteriophages: a large bacteriophage in a new class

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    The number of successful propagations/isolations of soil-borne bacteriophages is small in comparison to the number of bacteriophages observed by microscopy (great plaque count anomaly). As one resolution of the great plaque count anomaly, we use propagation in ultra-dilute agarose gels to isolate a Bacillus thuringiensis bacteriophage with a large head (95 nm in diameter), tail (486 × 26 nm), corkscrew-like tail fibers (187 × 10 nm) and genome (221 Kb) that cannot be detected by the usual procedures of microbiology. This new bacteriophage, called 0305φ8-36 (first number is month/year of isolation; remaining two numbers identify the host and bacteriophage), has a high dependence of plaque size on the concentration of a supporting agarose gel. Bacteriophage 0305φ8-36 does not propagate in the traditional gels used for bacteriophage plaque formation and also does not produce visible lysis of liquid cultures. Bacteriophage 0305φ8-36 aggregates and, during de novo isolation from the environment, is likely to be invisible to procedures of physical detection that use either filtration or centrifugal pelleting to remove bacteria. Bacteriophage 0305φ8-36 is in a new genomic class, based on genes for both structural components and DNA packaging ATPase. Thus, knowledge of environmental virus diversity is expanded with prospect of greater future expansion

    Estimating Dungeness crab (Cancer magister) abundance: crab pots and dive transects compared

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    Dungeness crabs (Cancer magister) were sampled with commercial pots and counted by scuba divers on benthic transects at eight sites near Glacier Bay, Alaska. Catch per unit of effort (CPUE) from pots was compared to the density estimates from dives to evaluate the bias and power of the two techniques. Yearly sampling was conducted in two seasons: April and September, from 1992 to 2000. Male CPUE estimates from pots were significantly lower in April than in the following September; a step-wise regression demonstrated that season accounted for more of the variation in male CPUE than did temperature. In both April and September, pot sampling was significantly biased against females. When females were categorized as ovigerous and nonovigerous, it was clear that ovigerous females accounted for the majority of the bias because pots were not biased against nonovigerous females. We compared the power of pots and dive transects in detecting trends in populations and found that pots had much higher power than dive transects. Despite their low power, the dive transects were very useful for detecting bias in our pot sampling and in identifying the optimal times of year to sample so that pot bias could be avoided

    Assessment of mood in aphasia following stroke: validation of the Dynamic Visual Analogue Mood Scales (D-VAMS)

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    OBJECTIVES: To validate a non-verbal self-report measure of mood - the Dynamic Visual Analogue Mood Scales (D-VAMS) - against the Hospital Anxiety and Depression Scale (HADS) and assess its suitability as an outcome measure or screening measure for depressed mood following stroke. DESIGN: Cross-sectional observational cohort study. PARTICIPANTS: Forty-six stroke survivors (24% with aphasia) recruited from online, from stroke clubs and via an NHS rehabilitation service. METHODS: A set of seven bipolar scales was developed enabling users to report mood by modifying facial expression images using a slider. Participants completed a tablet/computer task, reporting their mood on these scales mixed randomly with versions which used only words. The HADS was then completed, followed by a repeat run of the two versions in a different, random sequence. RESULTS: Exploratory factor analysis identified one factor consistent with pleasantness of mood accounting for 80% of the variance. Internal consistency of D-VAMS was high ( α = 0.95), and there was a high correlation between face-only D-VAMS scores and HADS total scores ( r = -0.80, P < 0.001), as well as HADS-D/HADS-A subscale scores ( r = -0.73, P < 0.001; r = -0.71, P < 0.001). D-VAMS showed good sensitivity and specificity against HADS, with means of 85%/77% (sensitivity/specificity) against the HADS-D and 80%/77% against the HADS-A across nine cut-offs. CONCLUSION: D-VAMS is a valid and reliable measure likely suitable for assessment of depressed mood in aphasia following stroke. Though D-VAMS performed well as a screening measure in this study sample, further study is needed in the acute stage post-stroke

    Fidelity protocol for the Action Success Knowledge (ASK) trial: A psychosocial intervention administered by speech and language therapists to prevent depression in people with post-stroke aphasia

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    Introduction: Treatment fidelity is a complex, multifaceted evaluative process which refers to whether a studied intervention was delivered as intended. Monitoring and enhancing fidelity is one recommendation of the TiDIER (Template for Intervention Description and Replication) checklist, as fidelity can inform interpretation and conclusions drawn about treatment effects. Despite the methodological and translational benefits, fidelity strategies have been used inconsistently within health behaviour intervention studies; in particular, within aphasia intervention studies, reporting of fidelity remains relatively rare. This paper describes the development of a fidelity protocol for the Action Success Knowledge (ASK) study, a current cluster randomised trial investigating an early mood intervention for people with aphasia (a language disability caused by stroke). Methods and analysis: A novel fidelity protocol and tool was developed to monitor and enhance fidelity within the two arms (experimental treatment and attention control) of the ASK study. The ASK fidelity protocol was developed based on the National Institutes of Health Behaviour Change Consortium fidelity framework. Ethics and dissemination: The study protocol was approved by the Darling Downs Hospital and Health Service Human Research Ethics Committee in Queensland, Australia under the National Mutual Acceptance scheme of multicentre human research projects. Specific ethics approval was obtained for those participating sites who were not under the National Mutual Agreement at the time of application. The monitoring and ongoing conduct of the research project is in line with requirements under the National Mutual Acceptance. On completion of the trial, findings from the fidelity reviews will be disseminated via publications and conference presentations. Trial registration number ACTRN12614000979651

    Effects of rumensin and bovatec on growth, feed intake, and feed efficiency in dairy calves

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    One hundred Holstein heifers were used to examine the effects of monensin (Rumensin®) and lasalocid (Bovatec®) included in calf starter and grower diets. Heifers were assigned alternately at birth to a starter feed containing either Rumensin (28 g/ton, 90% dry matter basis) or Bovatec (40 g/ton, 90% dry matter basis). The Bovatec group was switched to a starter feed containing 28 g Bovatec/ton (90% dry matter basis) at 6 weeks of age. Both groups were switched at 8 weeks of age to grower diets designed to deliver 100 mg/head/day of either Rumensin or Bovatec. No treatment differences were observed between birth and 8 weeks of age. Heifers were moved from individual hutches at 8 weeks of age to group pens (five heifers/pen) and remained on the same treatment for the next 84 days. During this 84-day period, heifers receiving Rumensin gained more weight at a faster rate and tended to be more efficient than heifers fed Bovatec. No differences were observed in feed intake, skeletal growth as measured by hip height, or body condition score

    Preliminary Multivariate Comparison of Coral Assemblages on Carbonate Banks in the Western Gulf of Mexico

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    Hermatypic corals flourished on reefs in the Gulf of Mexico (GOM) in the late Pleistocene and early Holocene. Today, many of these relict reefs are mesophotic banks that have unique coral assemblages and provide critical habitat; however, the South Texas Banks (STB) lack quantitative surveys. Therefore, we used a remotely operated vehicle to conduct quantitative surveys of 5 banks: Baker, Aransas, Dream, Blackfish Ridge, and Harte. Coral communities, based on estimated coral densities (colonies/m2), significantly differed among banks for terraces, slopes, and overall (combined terrace and slope) communities for most banks examined. Within banks, terrace and slope communities significantly differed for all banks except Harte. Sea whips were the most abundant group on slopes and terraces of most banks and frequently contributed \u3e50% to community similarities and dissimilarities, whereas sea fans and Antipathes frequently contributed \u3e20%. Total coral abundance was twice as high and sea fans were 7 times more abundant on terraces than slopes. Among—bank differences in coral communities were highly correlated to geographic and geomorphic features, especially to bank area, rugosity, longitude, and number of site components. The drivers of these differences, their effects on ecosystem diversity and function, and the connectivity pathways within and among STB and other GOM banks require further investigation. Nevertheless, the observed diversity in community structure within and among banks should be considered in the development of monitoring, conservation, and management plans of these critical habitats
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