121 resultados para National rock


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Rock-paper-scissors (RPS) dynamics, which maintain genetic polymorphisms over time through negative frequency-dependent (FD) selection, can evolve in short-lived species with no generational overlap, where they produce rapid morph frequency cycles. However, most species have overlapping generations and thus, rapid RPS dynamics are thought to require stronger FD selection, the existence of which yet needs to be proved. Here, we experimentally demonstrate that two cumulative selective episodes, FD sexual selection reinforced by FD selection on offspring survival, generate sufficiently strong selection to generate rapid morph frequency cycles in the European common lizard Zootoca vivipara, a multi-annual species with major generational overlap. These findings show that the conditions required for the evolution of RPS games are fulfilled by almost all species exhibiting genetic polymorphisms and suggest that RPS games may be responsible for the maintenance of genetic diversity in a wide range of species.

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BACKGROUND: About 30-50% of patients with Crohn's disease (CD) develop fistulae, implying significant disease burden and complicated clinical management. AIM: To assess appropriate use of therapy for fistulizing CD patients enrolled in the Swiss Inflammatory Bowel Disease Cohort using criteria developed by the European Panel on the Appropriateness of Crohn's disease Therapy. METHODS: Specific questionnaires were used to gather information on disease and its management. We assessed appropriateness of therapy at enrolment for adult CD patients with one or several fistulae. RESULTS: Two hundred and eighty-eight CD patients had fistulizing disease, of which 80% had complex fistulae and 32% currently had active draining fistulae. Mean age (s.d.) at diagnosis was 27 years (11), 51% males. Of the patients, 78% were judged as having globally an appropriate therapy, which was more often given for complex fistulae (87%) than for simple fistulae (67%). Antibiotics, azathioprine/MP, methotrexate and conservative surgery were almost always appropriate. Anti-tumor necrosis factor α was considered globally appropriate (91%), although most often with an uncertain indication. The 5ASA compounds, steroids and aggressive surgery were most often inappropriate (84%, 58% and 86% respectively). CONCLUSIONS: Formal appropriateness criteria for CD therapy were applied to a national cohort of IBD patients. For more than three-quarters of the patients with fistulizing CD, therapy was globally appropriate.

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The effective dose delivered to the patient was determined, by modeling, for 257 types of examinations covering the different modalities of diagnostic and interventional radiology. The basic operational dosimetric quantities considered were obtained from the parameters of the examinations on the basis of dosimetric models. These models required a precise characterization of each examination. The operational dosimetric quantities were converted into doses to organs and effective doses using appropriate conversion factors. The determination of the collective effective dose to the Swiss population requires a number of corrections to account for the variability of several parameters: sensitivity of the detection system, age, gender, and build of the patient. The use of various dosimetric models is illustrated in this paper for a limited number of examination types covering the different radiological modalities, for which the established typical effective doses are given. With regard to individual doses, the study indicated that the average effective doses per type of examination can be classified into three levels: (a) the weakly irradiating examinations (less than 0.1 mSv), which represent 78% of the examinations and 4% of the collective dose, (b) the moderately irradiating examinations (between 0.1 mSv and 10 mSv), which represent 21% of the examinations and 72% of the collective dose, (c) the strongly irradiating examinations (more than 10 mSv), which represent 1% of the examinations and 24% of the collective dose.

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Investigations of solute transport in fractured rock aquifers often rely on tracer test data acquired at a limited number of observation points. Such data do not, by themselves, allow detailed assessments of the spreading of the injected tracer plume. To better understand the transport behavior in a granitic aquifer, we combine tracer test data with single-hole ground-penetrating radar (GPR) reflection monitoring data. Five successful tracer tests were performed under various experimental conditions between two boreholes 6 m apart. For each experiment, saline tracer was injected into a previously identified packed-off transmissive fracture while repeatedly acquiring single-hole GPR reflection profiles together with electrical conductivity logs in the pumping borehole. By analyzing depth-migrated GPR difference images together with tracer breakthrough curves and associated simplified flow and transport modeling, we estimate (1) the number, the connectivity, and the geometry of fractures that contribute to tracer transport, (2) the velocity and the mass of tracer that was carried along each flow path, and (3) the effective transport parameters of the identified flow paths. We find a qualitative agreement when comparing the time evolution of GPR reflectivity strengths at strategic locations in the formation with those arising from simulated transport. The discrepancies are on the same order as those between observed and simulated breakthrough curves at the outflow locations. The rather subtle and repeatable GPR signals provide useful and complementary information to tracer test data acquired at the outflow locations and may help us to characterize transport phenomena in fractured rock aquifers.

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OBJECTIVES: To determine the epidemiology of biliary atresia (BA) in Switzerland, the outcome of the children from diagnosis, and the prognostic factors. PATIENTS AND METHODS: The records of all patients with BA born in Switzerland between January 1994 and December 2004 were analyzed. Survival rates were calculated with the Kaplan-Meier method, and prognostic factors evaluated with the log rank test. Median follow up was 58 months (range, 5-124). RESULTS: BA was diagnosed in 48 children. Incidence was 1 in 17,800 live births (95% confidence interval 1/13,900-1/24,800), without significant regional, annual, or seasonal variation. Forty-three children underwent a Kasai portoenterostomy (PE) in 5 different Swiss pediatric surgery units. Median age at Kasai PE was 68 days (range, 30-126). Four-year survival with native liver after Kasai PE was 37.4%. Liver transplantation (LT) was needed in 31 in 48 children with BA, including 5 patients without previous Kasai PE. Four patients (8%, all born before 2001) died while waiting for LT, and 29 LT were performed in 27 patients (28 in Geneva and 1 in Paris). All of the transplanted patients are alive. Four-year overall BA patient survival was 91.7%. Four-year survival with native liver was 75% in patients who underwent Kasai PE before 46 days, 33% in patients operated on between 46 and 75 days, and 11% in patients operated on after 75 days (P = 0.02). CONCLUSIONS: Overall survival of patients with BA in Switzerland compares favorably with current international standards, whereas results of the Kasai operation could be improved to reduce the need for LTs in infancy and early childhood.

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Approximately 1 million people in the United States and over 30 million worldwide are living with human immunodeficiency virus type 1 (HIV-1). While mortality from untreated infection approaches 100%, survival improves markedly with use of contemporary antiretroviral therapies (ART). In the United States, 25 drugs are approved for treating HIV-1, and increasing numbers are available in resource-limited countries. Safe and effective ART is a cornerstone in the global struggle against the acquired immunodeficiency syndrome. Variable responses to ART are due at least in part to human genetic variants that affect drug metabolism, drug disposition, and off-site drug targets. Defining effects of human genetic variants on HIV treatment toxicity, efficacy, and pharmacokinetics has far-reaching implications. In 2010, the National Institute of Allergy and Infectious Diseases sponsored a workshop entitled, Pharmacogenomics A Path Towards Personalized HIV Care. This article summarizes workshop objectives, presentations, discussions, and recommendations derived from this meeting.

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Chemical mass transfer was quantified in a metacarbonate xenolith enclosed within the granodiorite of the Qu,rigut massif (Pyrenees, France). Mass balance calculations suggest a strong decrease of CaO, SrO and CO(2) contents (up to -90%), correlated with a decrease of modal calcite content as the contact is approached. Most other chemical elements behave immobile during metasomatism. They are therefore passively enriched. Only a small increase of SiO(2), Al(2)O(3) and Fe(2)O(3) contents occurs in the immediate vicinity of the contact. Hence, in this study, skarn formation is characterized by the lack of large chemical element influx from the granitoid protolith. A large decrease of the initial carbonate volume (up to -86%) resulted from a combination of decarbonation reactions and loss of CaO and CO(2). The resulting volume change has potentially important consequences for the interpretation of stable isotope profiles: the isotope alteration could have occured over greater distances than those observed today.

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