91 research outputs found

    Stock status and potential yield of deep water rose shrimp (Parapenaeus longirostris, Lucas 1846) in the south-central Mediterranean Sea

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    This document summarises the data used, methods adopted and the results of the joint stock assessment carried out during the MedSudMed and CopeMed II Working Groups on Parapenaeus longirostris and related fisheries held in 2009 and 2010 in Malta and Italy respectively. The aim of this document is to describe the state of the stock of P. longirostris in the south-central Mediterranean Sea using data from Italy, Tunisia and Malta. The long term objective of this study is to provide the baseline for the establishment of a harmonised management regime for the deep water rose shrimp fishery in the south-central Mediterranean Sea. Overall, fishery dependent data from Italy, Malta and Tunisia for the first time were pooled together and jointly processed. The assessment was performed using length cohort analysis (LCA) and biomass and yield per recruits analyses as implemented in VIT4Win. Current mean fishing mortality and exploitation pattern were assessed using the steady state LCA on length frequency distributions (LFD) of 2007, 2008 and 2009 as well as the average 2007-2009 catches, raised to the total landings. Analyses were performed separately by keeping sex and fleet segments separate (i.e. Italy 12-24; Italy > 24; Tunisia; Malta) as first step. A sensitivity analysis was also carried out as implemented in VIT. The results are discussed in the view of providing robust technical advice for the management of national fisheries exploiting P. longirostris in the MedSudMed area taking into account the possible evolution of national fisheries. Some perspective for future joint activities to be carried out within the cooperative framework established by the FAO Projects are also presented.peer-reviewe

    Primary liposarcoma of the ascending colon: a rare case of mixed type presenting as hemoperitoneum combined with other type of retroperitoneal liposarcoma

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    <p>Abstract</p> <p>Background</p> <p>Liposarcoma occurs most commonly in the extremities and retroperitoneum, however, it has been rarely observed in the colon.</p> <p>Case Presentation</p> <p>A case is reported a 41-year-old man with liposarcoma of ascending colon which was presented as hemoperitoneum and combined with a different histological type of retroperitoneal liposarcoma. He visited hospital with right lower abdominal pain and palpable mass. Laboratory data including tumor markers were within normal limits, and computed tomography revealed a 15 Ă— 10 cm sized enhancing soft mass. Right hemicolectomy was performed, and after that, a further large retroperitoneal mass was revealed and this was also radically excised. Mixed-type colon liposarcoma and well differentiated type of retroperitoneal liposarcoma were diagnosed in pathologic report. The patient has remained free of disease for 24 months.</p> <p>Conclusions</p> <p>No standardized guidelines have been established for its treatment because too small a number of cases have been reported, but surgical resection was considered the treatment of choice.</p

    A HIV-1 Tat mutant protein disrupts HIV-1 Rev function by targeting the DEAD-box RNA helicase DDX1

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    BACKGROUND: Previously we described a transdominant negative mutant of the HIV-1 Tat protein, termed Nullbasic, that downregulated the steady state levels of unspliced and singly spliced viral mRNA, an activity caused by inhibition of HIV-1 Rev activity. Nullbasic also altered the subcellular localizations of Rev and other cellular proteins, including CRM1, B23 and C23 in a Rev-dependent manner, suggesting that Nullbasic may disrupt Rev function and trafficking by intervening with an unidentified component of the Rev nucleocytoplasmic transport complex. RESULTS: To seek a possible mechanism that could explain how Nullbasic inhibits Rev activity, we used a proteomics approach to identify host cellular proteins that interact with Nullbasic. Forty-six Nullbasic-binding proteins were identified by mass spectrometry including the DEAD-box RNA helicase, DDX1. To determine the effect of DDX1 on Nullbasic-mediated Rev activity, we performed cell-based immunoprecipitation assays, Rev reporter assays and bio-layer interferometry (BLI) assays. Interaction between DDX1 and Nullbasic was observed by co-immunoprecipitation of Nullbasic with endogenous DDX1 from cell lysates. BLI assays showed a direct interaction between Nullbasic and DDX1. Nullbasic affected DDX1 subcellular distribution in a Rev-independent manner. Interestingly overexpression of DDX1 in cells not only restored Rev-dependent mRNA export and gene expression in a Rev reporter assay but also partly reversed Nullbasic-induced Rev subcellular mislocalization. Moreover, HIV-1 wild type Tat co-immunoprecipitated with DDX1 and overexpression of Tat could rescue the unspliced viral mRNA levels inhibited by Nullbasic in HIV-1 expressing cells. CONCLUSIONS: Nullbasic was used to further define the complex mechanisms involved in the Rev-dependent nuclear export of the 9 kb and 4 kb viral RNAs. All together, these data indicate that DDX1 can be sequestered by Nullbasic leading to destabilization of the Rev nucleocytoplasmic transport complex and decreased levels of Rev-dependent viral transcripts. The outcomes support a role for DDX1 in maintenance of a Rev nuclear complex that transports viral RRE-containing mRNA to the cytoplasm. To our knowledge Nullbasic is the first anti-HIV protein that specifically targets the cellular protein DDX1 to block Rev’s activity. Furthermore, our research raises the possibility that wild type Tat may play a previously unrecognized but very important role in Rev function. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12977-014-0121-9) contains supplementary material, which is available to authorized users

    Studies Of Opportunity Recognition Process: Characteristics Of Tunisian Entrepreneur Profile

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    Entrepreneurial research has largely raised the question of the resources and profilecharacteristics of the entrepreneur required throughout the entrepreneurial process: recognition of anentrepreneurial opportunity, creation, and development. Entrepreneurs often find it challenging toobtain the resources they need as soon as they are overwhelmed by the desire to recognize anopportunity to do business independently. On the one hand, our problem emanates from the scarcity ofwork on the specificities of entrepreneurs in Tunisia, in this case, those of private companies. On theother hand, any influences that their characteristics might have on their competence in identifyingopportunity. Therefore, it would be a question of trying to identify the profile of the entrepreneur inTunisian companies and appreciate the possible impacts that it could have on the characteristicstheoretically considered within the upstream entrepreneurial process. In this perspective, we propose tofocus our thinking, on the one hand, on the approach supported by entrepreneurs to recognize anentrepreneurial opportunity and, on the other hand, its impact on the recognition of entrepreneurialopportunity mobilized in this approach. This study explored the process of recognizing the opportunitiesof 80 Tunisian entrepreneurs, who were all recognized as having business opportunities and differentcharacteristics

    A combinatorial particle swarm optimisation for solving permutation flowshop problems

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