746 research outputs found
The U.S. Gulf of Mexico Pink Shrimp, Farfantepenaeus duorarum, Fishery: 50 Years of Commercial Catch Statistics
U.S. Gulf of Mexico, pink shrimp, Farfantepenaeus duorarum, catch statistics have been collected by NOAA’s National Marine Fisheries Service, or its predecessor agency, for over 50 years. Recent events, including hurricanes and oil spills within the ecosystem of the fishery, have shown that documentation of these catch data is of primary importance. Fishing effort for this stock has fluctuated over the 50-year period analyzed, ranging from 3,376 to 31,900 days fished, with the most recent years on record, 2008 and 2009, exhibiting declines up to 90% relative to the high levels recorded in the mid 1990’s. Our quantification of F. duorarum landings and catch rates (CPUE) indicates catch have been below the long-term average of about 12 million lb for all of the last 10 years on record. In contrast to catch and effort, catch rates have increased in recent years, with record CPUE levels measured in 2008 and 2009, of 1,340 and 1,144 lb per day fished, respectively. Our regression results revealed catch was dependent upon fishing effort (F=98.48df=1, 48, p<0.001, r2=0.67), (Catch=1,623,378 + (520) × (effort)). High CPUE’s measured indicate stocks were not in decline prior to 2009, despite the decline in catch. The decrease in catch is attributed in large part to low effort levels caused by economical and not biological or habitat related conditions. Future stock assessments using these baseline data will provide further insights and management advice concerning the Gulf of Mexi
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Clustering and networking among small independent hotels: developments over ten years
This paper reports on networking activities amongst a cluster of independent hotels with a view to analysing key variables in network development for SMEs. A comparative, longitudinal element is introduced by reference to an earlier study of the same phenomenon, ten years earlier. Of particular interest is the influence of various forms of social capital in the development of informal networks and the inter-play between co-operation and competition over time. Given the time gap between the two studies, the effect of sectoral changes on network development is also examined. The research revisits and extends a previous study of many of the same hotels which were investigated in 1995 over their formal and informal links that were found to be influenced by such factors across two classifications - the business as unit (proximity, perceptions of quality) and the individual respondent (personal social networks and ethnicity). Extending that analysis, social capital concepts and relevant references to embedded networks and kinship groups and co-operative game rules will be introduced in this paper.
A highly concentrated population of small, independent hotels in Central London had been identified in the previous research project and it is from this sample that the current research drew and extended its own sample of hotels. With such a high number of hotels in the area a mixture of ‘snowball’ sampling and self-selection was successfully employed. Of the original 29 hotels, 22 have been re-interviewed and complemented by another 19. Of the remainder of the original sample, several had subsequently merged or failed to survive the intervening period. Face-to-face interviews were conducted with owner-managers in all cases using a structured questionnaire that replicated as much as possible of the original questionnaire, with both open and closed questions to allow some individual expression on relevant topics. The quantitative data obtained will be analysed using UCINET software to generate visual representations of networks alongside statistical and cluster analyses.
Both academic and policy implications are likely to arise from this research, such as novel insights from such an unique periodic comparison of networks development, the influence of social capital on (formal and informal) network activities and the changing influence and consolidation of hotel groups through mergers and franchising
The incidence of mental deficiency in a community and a study of the natural history of mental deficiency in the hospital group catering for that community
Abstract Not Provided
Control of cellular automata
We study the problem of master-slave synchronization and control of
totalistic cellular automata (CA) by putting a fraction of sites of the slave
equal to those of the master and finding the distance between both as a
function of this fraction. We present three control strategies that exploit
local information about the CA, mainly, the number of nonzero Boolean
derivatives. When no local information is used, we speak of synchronization. We
find the critical properties of control and discuss the best control strategy
compared with synchronization
T cells but not NK cells are associated with a favourable outcome for resected colorectal liver metastases
T cells, but not NK cells, are preferentially recruited to colorectal liver metastases. NK cells within colorectal metastases have an intrahepatic and potentially tolerogenic, rather than a peripheral, phenotype. Similar to primary tumours, the magnitude of the T cell infiltrate in colorectal metastases is positively associated with surviva
Current standards and future perspectives in adjuvant treatment for biliary tract cancers
Biliary tract cancer, including cholangiocarcinoma (CCA) and gallbladder cancer (GBC) are rare tumours with a rising incidence. Prognosis is poor, since most patients are diagnosed with advanced disease. Only ∼20% of patients are diagnosed with early-stage disease, suitable for curative surgery. Despite surgery performed with potentially-curative intent, relapse rates are high, with around 60-70% of patients expected to have disease recurrence. Most relapses occur in the form of distant metastases, with a predominance of liver spread. In view of high tumour recurrence, adjuvant strategies have been explored for many years, in the form of radiotherapy, chemo-radiotherapy and chemotherapy. Historically, few randomised trials were available, including a variety of additional tumours (e.g. pancreatic and ampullary tumours) and most evidence relied on phase II and retrospective studies, with no high-quality evidence available to define the real benefit derived from adjuvant strategies. Since 2017, three randomised phase III clinical trials have been reported; all recruited patients with resected biliary tract cancer (CCA and GBC) who were randomised to observation alone, or chemotherapy in the form of gemcitabine (BCAT study; included patients diagnosed with extrahepatic CCA only), gemcitabine and oxaliplatin (PRODIGE-12/ACCORD-18; included patients diagnosed with CCA and GBC) or capecitabine (BILCAP; included patients diagnosed with CCA and GBC). While gemcitabine-based chemotherapy failed to show an impact on patient outcome (relapse-free survival (RFS) or overall survival (OS)), the BILCAP study showed a benefit from adjuvant capecitabine in terms of OS (pre-planned sensitivity analysis in the intention-to-treat population and in the per-protocol analysis), with confirmed benefit in terms of RFS. Based on the BILCAP trial, international guidelines recommend adjuvant capecitabine for a period of six months following potentially curative resection of CCA as the current standard of care for resected CCA and GBC. However, BILCAP failed to show OS benefit in the intention-to-treat (non-sensitivity analysis) population (primary end-point), and this finding, as well as some inconsistencies between studies has been criticised and has led to confusion in the biliary tract cancer medical community. This review summarises the adjuvant field in biliary tract cancer, with evidence before and after 2017, and comparison between the latest randomised phase III studies. Potential explanations are presented for differential findings, and future steps are explored
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