178 research outputs found

    Geographic Variability in the Life History and Demography of Canary Rockfish, Sebastes pinniger, Along the U.S. West Coast

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    Marine fishes that persist across broad geographic ranges experience gradients in environmental and oceanographic conditions, anthropogenic stressors, and ecological factors that influence their population dynamics Understanding the spatial and temporal scale at which life history characteristics and demographic patterns vary is essential for successful management and long term sustainability of marine fisheries The Canary Rockfish is a commercially and recreationally valuable groundfish species along the West Coast of North America. After being declared overfished in 2000, several restrictions were put in place to constrain commercial and recreational fishing opportunities These restrictions coupled with favorable ocean conditions led to the recovery of the Canary Rockfish stock to a rebuilt status of 40% unfished biomass in 201 5. Despite being an important species in the management of U.S. West Coast fisheries, the life history of Canary Rockfish across untrawlable habitat s have rarely been described, including latitudinal patterns in life history traits and population demography. From 2017 through 2019, 1,567 Canary Rockfish were collected from 13 port locations along the U.S. West Coast, to investigate latitudinal patterns in size and age structure, growth, maturity, condition, and mortality, as wells as to identify biologically relevant population breakpoints along the coast. Sex specific differences in life history parameters were al so investigated coastwide. Canary Rockfish exhibited strong latitudinal patterns in life history parameters; Canary Rockfish from colder, northern port locations exhibited larger sizes at age, lived longer had variable condition, matured at larger sizes a nd older ages and had lower mortality rates than Canary Rockfish from warmer, southern port locations. Male Canary Rockfish exhibited smaller sizes at age, lived longer, were in similar condition and matured at similar sizes in comparison to female conspecifics. Trends in life history parameters related to size, age and maturity were negatively correlated with coastwide patterns in sea surface temperature a nd positively correlated with coastwide patterns in primary productivity (chlorophyll a Cluster analysis using life history traits indicated central Oregon as a biologically relevant break point for Canary Rockfish populations along the U.S. West Coast and should be considered in future stock assessment models. Further research should explore stock structure through genetic analysis and compare hook and line data from untrawlable habitats with fishery independent bottom trawl surveys to assess habitat based differences in Canary Rockfish life history and demography

    External fishing effort regulates positive effects of no-take marine protected areas

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    Marine protected areas (MPAs) have been established across the globe to mitigate the effects of multiple stressors on marine communities. In many locations, MPAs have generated positive effects on fish communities, but the impacts of fishing pressure—the primary stressor MPAs seek to manage—have not been well investigated. We examined changes in fish biomass inside and outside of no-take MPAs over 14 years in central California, USA. Using data from the community-based science program, the California Collaborative Fisheries Research Program, we tested which environmental and human-induced stressors most influence the strength of MPA responses. While temperature and productivity were included in the best fit model, we found that fine-scale fishing effort data, following reserve implementation, best explained the spatial variation in fish community responses to MPAs. Specifically, differences in fish biomass between MPAs and sites open to fishing were larger for reserves near heavily fished locations and these areas exhibited the highest rate of change in fish biomass, indicating strong positive effects of the MPA on the most heavily exploited fish communities. As MPAs continue to be used as a prominent conservation strategy in coastal systems, managers should consider both the suite of human-induced (socio-ecological interactions) and environmental conditions that may alter MPA success as well as establish long-term monitoring programs to fully assess the functionality of marine reserves into the future

    Marine protected areas, marine heatwaves, and the resilience of nearshore fish communities

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    Anthropogenic stressors from climate change can affect individual species, community structure, and ecosystem function. Marine heatwaves (MHWs) are intense thermal anomalies where water temperature is significantly elevated for five or more days. Climate projections suggest an increase in the frequency and severity of MHWs in the coming decades. While there is evidence that marine protected areas (MPAs) may be able to buffer individual species from climate impacts, there is not sufficient evidence to support the idea that MPAs can mitigate large-scale changes in marine communities in response to MHWs. California experienced an intense MHW and subsequent El Niño Southern Oscillation event from 2014 to 2016. We sought to examine changes in rocky reef fish communities at four MPAs and associated reference sites in relation to the MHW. We observed a decline in taxonomic diversity and a profound shift in trophic diversity inside and outside MPAs following the MHW. However, MPAs seemed to dampen the loss of trophic diversity and in the four years following the MHW, taxonomic diversity recovered 75% faster in the MPAs compared to reference sites. Our results suggest that MPAs may contribute to long-term resilience of nearshore fish communities through both resistance to change and recovery from warming events

    International education and the employability of UK students

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    A common theme within the literature on higher education is the congested nature of the graduate labour market. Researchers have highlighted the lengths to which many students now go, in response to this congestion, to ‘distinguish themselves’ from other graduates: paying increased attention to university status; engaging in a range of extra-curricular activities; and pursuing postgraduate qualifications. Studies that have focused on the strategies of Asian students, specifically, have pointed to the important place of studying abroad as a further strategy in this pursuit of distinction. Given that there is now some evidence that the number of UK students enrolling on a degree programme overseas is increasing, this article explores the extent to which an overseas education can be seen as part of a broader strategy on the part of British students to seek distinction within the labour market and whether such an education does indeed offer tangible employment benefits

    Cerebellar Integrity in the Amyotrophic Lateral Sclerosis - Frontotemporal Dementia Continuum

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    Amyotrophic lateral sclerosis (ALS) and behavioural variant frontotemporal dementia (bvFTD) are multisystem neurodegenerative disorders that manifest overlapping cognitive, neuropsychiatric and motor features. The cerebellum has long been known to be crucial for intact motor function although emerging evidence over the past decade has attributed cognitive and neuropsychiatric processes to this structure. The current study set out i) to establish the integrity of cerebellar subregions in the amyotrophic lateral sclerosis-behavioural variant frontotemporal dementia spectrum (ALS-bvFTD) and ii) determine whether specific cerebellar atrophy regions are associated with cognitive, neuropsychiatric and motor symptoms in the patients. Seventy-eight patients diagnosed with ALS, ALS-bvFTD, behavioural variant frontotemporal dementia (bvFTD), most without C9ORF72 gene abnormalities, and healthy controls were investigated. Participants underwent cognitive, neuropsychiatric and functional evaluation as well as structural imaging using voxel-based morphometry (VBM) to examine the grey matter subregions of the cerebellar lobules, vermis and crus. VBM analyses revealed: i) significant grey matter atrophy in the cerebellum across the whole ALS-bvFTD continuum; ii) atrophy predominantly of the superior cerebellum and crus in bvFTD patients, atrophy of the inferior cerebellum and vermis in ALS patients, while ALS-bvFTD patients had both patterns of atrophy. Post-hoc covariance analyses revealed that cognitive and neuropsychiatric symptoms were particularly associated with atrophy of the crus and superior lobule, while motor symptoms were more associated with atrophy of the inferior lobules. Taken together, these findings indicate an important role of the cerebellum in the ALS-bvFTD disease spectrum, with all three clinical phenotypes demonstrating specific patterns of subregional atrophy that associated with different symptomology

    British Society of Gastroenterology guidance for management of inflammatory bowel disease during the COVID-19 pandemic.

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    The COVID-19 pandemic is putting unprecedented pressures on healthcare systems globally. Early insights have been made possible by rapid sharing of data from China and Italy. In the UK, we have rapidly mobilised inflammatory bowel disease (IBD) centres in order that preparations can be made to protect our patients and the clinical services they rely on. This is a novel coronavirus; much is unknown as to how it will affect people with IBD. We also lack information about the impact of different immunosuppressive medications. To address this uncertainty, the British Society of Gastroenterology (BSG) COVID-19 IBD Working Group has used the best available data and expert opinion to generate a risk grid that groups patients into highest, moderate and lowest risk categories. This grid allows patients to be instructed to follow the UK government's advice for shielding, stringent and standard advice regarding social distancing, respectively. Further considerations are given to service provision, medical and surgical therapy, endoscopy, imaging and clinical trials

    Mapping of the Disease Locus and Identification of ADAMTS10 As a Candidate Gene in a Canine Model of Primary Open Angle Glaucoma

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    Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide, with elevated intraocular pressure as an important risk factor. Increased resistance to outflow of aqueous humor through the trabecular meshwork causes elevated intraocular pressure, but the specific mechanisms are unknown. In this study, we used genome-wide SNP arrays to map the disease gene in a colony of Beagle dogs with inherited POAG to within a single 4 Mb locus on canine chromosome 20. The Beagle POAG locus is syntenic to a previously mapped human quantitative trait locus for intraocular pressure on human chromosome 19. Sequence capture and next-generation sequencing of the entire canine POAG locus revealed a total of 2,692 SNPs segregating with disease. Of the disease-segregating SNPs, 54 were within exons, 8 of which result in amino acid substitutions. The strongest candidate variant causes a glycine to arginine substitution in a highly conserved region of the metalloproteinase ADAMTS10. Western blotting revealed ADAMTS10 protein is preferentially expressed in the trabecular meshwork, supporting an effect of the variant specific to aqueous humor outflow. The Gly661Arg variant in ADAMTS10 found in the POAG Beagles suggests that altered processing of extracellular matrix and/or defects in microfibril structure or function may be involved in raising intraocular pressure, offering specific biochemical targets for future research and treatment strategies

    Host galaxy identification for supernova surveys

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    Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated algorithm is run on catalog data and matches SNe to their hosts with 91% accuracy. We find that including a machine learning component, run after the initial matching algorithm, improves the accuracy (purity) of the matching to 97% with a 2% cost in efficiency (true positive rate). Although the exact results are dependent on the details of the survey and the galaxy catalogs used, the method of identifying host galaxies we outline here can be applied to any transient survey

    Abstracts of presentations on plant protection issues at the xth international congress of virology: August 11-16, 1996 Binyanei haOoma, Jerusalem Iarael part 3(final part)

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