254 research outputs found

    Smoking Experimentation in Adolescents. Is There a Risk for Health?

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    peer reviewedIt is clear that even low rate smoking is hazardous for health, the risk being independently increased by the daily number of cigarettes smoked and by the duration of smoking. The question raised is thus: will an adolescent experimenter be a non smoker, an experimenter for ever, a regular smoker, light or heavy? This short review shows that there are numerous factors from genetics, to familial environment not limited to tobacco issues, smoking situation at school as well as school performances of the student, and also individual psychological characteristics. The experimenter is a very good target for smoking cessation actions and should deserve particular attention from preventive medicine and, thus, from school medicine, before he becomes a regular smoker, who will be more resistant to smoking cessation programs

    Model Driven Engineering and Dependability Analyses: The Topcased Approach

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    International audienceModel Driven Engineering approaches are widely promoted to overcome difficulties to design, validate and maintain large complex systems. They present interesting dependability characteristics especially in terms of prevention of design faults and validation of design correctness. However industrial needs, practices and applicable standards impose constraints on the dependability activities to perform and justify. Therefore it is necessary to analyze how a complete dependability and safety process can be integrated with model-driven approaches within a seamless global process: which dependability activities are naturally covered or facilitated by model-driven approaches, and which additional activities are needed with which support. This paper presents the results of a study aiming at the establishment of requirements to model-driven engineering methods and tools, to support dependability analyses

    Human immunodeficiency virus type 1 incidence among blood donors in France, 1992 through 2006: use of an immunoassay to identify recent infections

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    BACKGROUND: In France, blood donations found to be positive for the presence of human immunodeficiency virus type 1 (HIV-1) are further tested to detect recent infections (≤180 days) using an enzyme immunoassay (EIA-RI) developed in 2002. The characteristics of recently infected donors, estimates of HIV-1 incidence, and the residual risk of transfusion-transmitted HIV-1 are presented, in both first-time and repeat donors. STUDY DESIGN AND METHODS: Of the 1027 donations found to be HIV-1–positive between 1992 and 2006, a total of 459 could be retrospectively tested with the EIA-RI. Multivariate analysis was performed to determine the donor characteristics associated with recent infection. Incidence rates and residual risk obtained with the EIA-RI were compared to classical cohort estimates derived from repeat donor histories. RESULTS: Of the 459 HIV-1–positive donors studied, 105 (22.9%; 95% confidence interval [CI], 19.2-27.0) were identified as recently infected. Factors independently associated with recent infection were repeat donor status (adjusted odds ratio [AOR], 4.0; 95% CI, 2.4-6.9) and non-B subtypes (AOR, 2.0; 95% CI, 1.2-3.6). Incidence decreased from 4.3 (95% CI, 1.9-9.4) in 1992 through 1994 to 1.3 (95% CI, 0.6-2.8) per 105 in 2004 through 2006 in first-time donors and from 3.2 (95% CI, 2.0-5.0) to 0.8 (95% CI, 0.4-1.4) per 105 in repeat donors. Incidence and residual risk estimates were similar to those obtained with the classical cohort method. CONCLUSION: This study suggests that the EIA-RI can be used to estimate HIV-1 incidence in a population with low HIV incidence. The estimated HIV-1 incidence in the blood donor population confirms the extremely low risk (1 in 3,350,000 donations) of HIV-infected blood donations entering the blood supply in France

    Harnessing difference: a capability-based framework for stakeholder engagement in environmental innovation

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    Innovation for environmental sustainability requires firms to engage with external stakeholders to access expertise, solve complex problems, and gain social legitimacy. In this open innovation context, stakeholder engagement is construed as a dynamic capability that can harness differences between external stakeholders to augment their respective resource bases. An integrative systematic review of evidence from 88 scientific articles finds that engaging stakeholders in environmental innovation requires three distinct levels of capability: specific operational capabilities; first-order dynamic capabilities to manage the engagement (engagement management capabilities); and second-order dynamic capabilities to make use of contrasting ways of seeing the world to reframe problems, combine competencies in new ways, and co-create innovative solutions (value framing), and to learn from stakeholder engagement activities (systematized learning). These findings enhance understanding of how firms can effectively incorporate stakeholder perspectives for environmental innovation, and provide an organizing framework for further research into open innovation and co-creation more broadly. Wider contributions to the dynamic capabilities literature are to (i) offer a departure point for further research into the relationship between first-order and second-order dynamic capabilities, (ii) suggest that institutional theory can help explain the dynamic capability of value framing, (iii) build on evidence that inter-institutional learning is contingent on not only the similarity but also the differences between organizational value frames, and (iv) suggest that operating capabilities impact the effectiveness of dynamic capabilities, rather than only the other way around, as is usually assumed. A methodological contribution is made through the application of quality assessment criteria scores and intercoder reliability statistics to the selection of articles included in the systematic review

    Harnessing difference: a capability-based framework for stakeholder engagement in environmental innovation

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    Innovation for environmental sustainability requires firms to engage with external stakeholders to access expertise, solve complex problems, and gain social legitimacy. In this open innovation context, stakeholder engagement is construed as a dynamic capability that can harness differences between external stakeholders to augment their respective resource bases. An integrative systematic review of evidence from 88 scientific articles finds that engaging stakeholders in environmental innovation requires three distinct levels of capability: specific operational capabilities; first-order dynamic capabilities to manage the engagement (engagement management capabilities); and second-order dynamic capabilities to make use of contrasting ways of seeing the world to reframe problems, combine competencies in new ways, and co-create innovative solutions (value framing), and to learn from stakeholder engagement activities (systematized learning). These findings enhance understanding of how firms can effectively incorporate stakeholder perspectives for environmental innovation, and provide an organizing framework for further research into open innovation and co-creation more broadly. Wider contributions to the dynamic capabilities literature are to (i) offer a departure point for further research into the relationship between first-order and second-order dynamic capabilities, (ii) suggest that institutional theory can help explain the dynamic capability of value framing, (iii) build on evidence that inter-institutional learning is contingent on not only the similarity but also the differences between organizational value frames, and (iv) suggest that operating capabilities impact the effectiveness of dynamic capabilities, rather than only the other way around, as is usually assumed. A methodological contribution is made through the application of quality assessment criteria scores and intercoder reliability statistics to the selection of articles included in the systematic review

    A revised method for estimating hepatitis B virus transfusion residual risk based on antibody to hepatitis B core antigen incident cases

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    BACKGROUND: To take into account the transient nature of hepatitis B virus (HBV) antigenemia, the calculation of HBV residual risk (RR), based on the incidence/window period model, is adjusted by a correction factor that adds uncertainty to the RR estimates. STUDY DESIGN AND METHODS: This new method to estimate the RR for HBV is a weighted sum of the RR derived from hepatitis B surface antigen (HBsAg) incident cases and the one derived from antibody hepatitis B core antigen (HBc) incident cases. An anti-HBc incident case was defined as a donation from a blood donor who had made at least one anti-HBc–negative donation followed by a donation that was found positive with two different assays within a 3-year period and positive for at least one of the following markers: 1) antibody to hepatitis B e antigen or hepatitis B e antigen, 2) anti-HBc immunoglobulin M, 3) HBV DNA, 4) hepatitis B surface antibody without HBV vaccination history, or 5) HBV DNA retrospectively found in the previous donation. Five overlapping 3-year study periods between 2000 and 2006 were analyzed. RESULTS: The HBV RR estimated with the classical method ranged from 1.51 (2000-2002) to 0.69 per million donations in 2004 through 2006 with a decrease in 2002 through 2004 due to only two HBsAg incident cases reported in this period. By applying the revised model, the HBV RR ranged from 1.06 (2000-2002) to 0.49 per million donations (2004-2006), with a regular decrease. CONCLUSION: The new presented model provides HBV RR estimates that do not statistically differ from those obtained with the classical model; however, it provides more accurate data, especially in low endemic areas where the HBsAg incidence is low

    Multiple thromboembolism with multiple causes in a 69-year-old woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Aggressive, recurrent embolisms require accurate etiologic diagnosis. We describe the case of a 69-year-old Italian Caucasian woman with recurrent arterial embolisms in whom several sources and triggers of thrombosis were detected.</p> <p>Case presentation</p> <p>The patient, a 69-year-old Italian Caucasian woman, presented with a systemic embolism that was initially attributed to atrial fibrillation. The recurrence of embolisms despite anti-thrombotic therapy prompted a re-evaluation of the clinical presentation. New potential causes of thrombosis emerged in this patient, including thrombocytosis associated with the <it>JAK2 V617F </it>mutation and the very rare mural thrombosis of the descending aorta. A mural thrombus in the pulmonary artery was detected contiguous with the aortic mural thrombosis, raising the possibility of a clinically silent ductus Botalli as the initiating event. The patient was treated with warfarin, aspirin, hydroxyurea, and surgery.</p> <p>Conclusions</p> <p>The diagnosis was achieved via systematic use of imaging procedures and reconsideration of blood tests performed to explore the diagnosis of thrombosis. This allowed a deeper and more detailed analysis of the case beyond the conventional approach, which would have aimed to identify one cause for the condition at hand, in this case, atrial fibrillation. The broader approach that we used resulted in the diagnosis of multiple embolisms from multiple sites and multiple causes.</p

    Evolutionary history of hepatitis C virus genotype 5a in France, a multicenter ANRS study

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    The epidemic history of HCV genotype 5a is poorly documented in France, where its prevalence is very low, except in a small central area, where it accounts for 14.2% of chronic hepatitis C cases. A Bayesian coalescent phylogenetic investigation based on the E1 envelope gene and a non-structural genomic segment (NS3/4) was carried out to trace the origin of this epidemic using a large sample of genotype 5a isolates collected throughout France. The dates of documented transmissions by blood transfusion were used to calibrate five nodes in the phylogeny. The results of the E1 gene analysis showed that the best-fitting population dynamic model was the expansion growth model under a relaxed molecular clock. The rate of nucleotide substitutions and time to the most recent common ancestors (tMRCA) of genotype 5a isolates were estimated. The divergence of all the French HCV genotype 5a strains included in this study was dated to 1939 [95% HPD: 1921–1956], and the tMRCA of isolates from central France was dated to 1954 [1942–1967], which is in agreement with epidemiological data. NS3/4 analysis provided similar estimates with strongly overlapping HPD values. Phylodynamic analyses give a plausible reconstruction of the evolutionary history of HCV genotype 5a in France, suggesting the concomitant roles of transfusion, iatrogenic route and intra-familial transmission in viral diffusion

    QTLs for oil yield components in an elite oil palm (Elaeis guineensis) cross

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    Increased modern farming of superior types of the oil palm, Elaeis guineensis Jacq., which has naturally efficient oil biosynthesis, has made it the world’s foremost edible oil crop. Breeding improvement is, however, circumscribed by time and costs associated with the tree’s long reproductive cycle, large size and 10–15 years of field testing. Marker-assisted breeding has considerable potential for improving this crop. Towards this, quantitative trait loci (QTL) linked to oil yield component traits were mapped in a high-yield population. In total, 164 QTLs associated with 21 oil yield component traits were discovered, with cumulative QTL effects increasing in tandem with the number of QTL markers and matching the QT+ alleles for each trait. The QTLs confirmed all traits to be polygenic, with many genes of individual small effects on independent loci, but epistatic interactions are not ruled out. Furthermore, several QTLs maybe pleiotropic as suggested by QTL clustering of inter-related traits on almost all linkage groups. Certain regions of the chromosomes seem richer in the genes affecting a particular yield component trait and likely encompass pleiotropic, epistatic and heterotic effects. A large proportion of the identified additive effects from QTLs may actually arise from genic interactions between loci. Comparisons with previous mapping studies show that most of the QTLs were for similar traits and shared similar marker intervals on the same linkage groups. Practical applications for such QTLs in marker-assisted breeding will require seeking them out in different genetic backgrounds and environments
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