968 resultados para double sample selection


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The way an organism spreads its reproduction over time is defined as a life-history trait, and selection is expected to favour life-history traits associated with the highest fitness return. We use a long-term dataset of 277 life histories to investigate the shape and strength of selection acting on the age at first reproduction and at last reproduction in the long-lived Alpine Swift. Both traits were under strong directional selection, but in opposite directions, with selection favouring birds starting their reproductive career early and being able to reproduce for longer. There was also evidence for stabilising selection acting on both traits, suggesting that individuals should nonetheless refrain from reproducing in their first 2 years of life (i.e. when inexperienced), and that reproducing after 7 years of age had little effect on lifetime fitness, probably due to senescence.

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Objective: To identify and prioritize improvement opportunities, according to the European Foundation for Quality Management model (EFQM) model, of the methadone dispensing service in Andalusian Primary Health Care, from the point of view of professionals. Method: Delphi consensus method, implemented from September 2007 to March 2008 by means of three rounds of interviews with questionnaires administered by electronic mail to 39 professionals. The Panel of experts was made up of Dispensers and Prescribers of methadone as well as Coordinators of welfare services from the Methadone Treatment Program (MTP). Selection criteria were: Being in active employment with a minimum of 3 years experience. Sample diversification variables: Professional role, geographical environment and type of habitat. Recruitment: By means of key professional bodies from different institutions. Results: 48 improvement opportunities were identified. Thirteen of these obtained a high level of agreement in the final round. According to the EFQM model, the dimensions that obtained the most consensus in relation to improving the care service were: Leadership, Alliances and Resources. The dimension that caused the greatest disagreement was Processes. Conclusions: In spite of its having been implemented since 1997 in Andalusian Primary Health Care, the methadone dispensing service is at an implementation phase, rather than what could be classed as a fully deployed stage

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Aquest estudi representa la primera exploració de l'ús de la televisió i la selecció de programes per part de grups d'indígenes a Chiapas. Més concretament, s'examina com els membres d'aquests grups seleccionen canals i programes específics dels mitjans de comunicació per raons d'etnicitat, i com això té a veure amb estratègies de mobilitat social. Les dades de 173 indígenes estudiants de la universitat Intercultural de Chiapas van indicar que per a 77 membres d'aquesta mostra, veure la televisió i seleccionar programes sobre la base de la seva etnicitat és una activitat de visualització important per a la seva autoestima etnolingüística. Aquests resultats es discuteixen en termes de la representació televisiva dels grups ètnics de Chiapas i motiven la realització de futures investigacions sobre aquests temes a Chiapas.

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Two endangered tetraonids, the capercaillie (Tetrao urogallus) and the hazel grouse (Bonasa bonasia rupestris), are sympatric throughout part of their distribution range in central Europe. Precise information on their specific habitat requirements is needed if the coexistence of both species in exploited forests is to be maintained. We quantified winter habitat selection for both species in the upper part (1100-1600 m) of the Jura mountains (Switzerland). No preference for altitude or exposure could be detected. Capercaillie preferred open forests (including grazed forests) with a sparse canopy dominated by spruce (Picea abies) and fir (Abies alba), and avoided dense undercanopy and understorey, especially when dominated by spruce and beech (Fagus sylvatica). By contrast, hazel grouse preferred feeding sites with a dense understorey of rowan (Sorbus aucuparia), willow (Salix sp.), beech and spruce. These preferences can be related to the feeding habits and predator avoidance behaviour of both species. Coexistence thus requires a mosaic distribution of habitat types, with a matrix of open forests (30% canopy cover) where fir is favoured, and understorey kept sparse (20%). Group-cuts of mature trees should allow regeneration patches, where a dense understorey (50% cover) should provide suitable habitats for hazel grouse

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The study investigated the development and stage specificity of physiological resistance to insecticides in a colony of Culex quinquefasciatus Say (Diptera: Culicidae) mosquitoes, which are vectors of bancroftian filariasis in India, after selection with deltamethrin. Resistance was selected by exposing the larvae to the concentration of deltamethrin that caused 50% mortality in the tested population (i.e., LC50). Under continuous selection pressure, the LC50 increased steadily in subsequent generations. The estimated LC50 for the F0 generation was 0.409 μg/L; the LC50 first displayed a substantial increase in the F5 generation (5.616 μg/L) and reached 121.902 μg/L in the F10 generation. The objective of this study was to establish a deltamethrin-resistant colony to develop a research programme that will study the evolution of physiological resistance patterns and stage-specific resistance responses in Cx. quinquefasciatus larvae and adults under laboratory conditions. An approximately 298-fold increase in resistance was recorded after 10 generations, as evidenced by the resistance ratio (RR50). The progress and effect of the selection pressure in the adult stage was monitored with the World Health Organisation (WHO) diagnostic test. The mortality, as observed using the WHO diagnostic test, declined significantly from the F5 generation (85%) onwards and the highest rate of survival (65%) was observed in the F10 generation.

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BACKGROUND: To improve the efficacy of first-line therapy for advanced non-small cell lung cancer (NSCLC), additional maintenance chemotherapy may be given after initial induction chemotherapy in patients who did not progress during the initial treatment, rather than waiting for disease progression to administer second-line treatment. Maintenance therapy may consist of an agent that either was or was not present in the induction regimen. The antifolate pemetrexed is efficacious in combination with cisplatin for first-line treatment of advanced NSCLC and has shown efficacy as a maintenance agent in studies in which it was not included in the induction regimen. We designed a phase III study to determine if pemetrexed maintenance therapy improves progression-free survival (PFS) and overall survival (OS) after cisplatin/pemetrexed induction therapy in patients with advanced nonsquamous NSCLC. Furthermore, since evidence suggests expression levels of thymidylate synthase, the primary target of pemetrexed, may be associated with responsiveness to pemetrexed, translational research will address whether thymidylate synthase expression correlates with efficacy outcomes of pemetrexed. METHODS/DESIGN: Approximately 900 patients will receive four cycles of induction chemotherapy consisting of pemetrexed (500 mg/m2) and cisplatin (75 mg/m2) on day 1 of a 21-day cycle. Patients with an Eastern Cooperative Oncology Group performance status of 0 or 1 who have not progressed during induction therapy will randomly receive (in a 2:1 ratio) one of two double-blind maintenance regimens: pemetrexed (500 mg/m2 on day 1 of a 21-day cycle) plus best supportive care (BSC) or placebo plus BSC. The primary objective is to compare PFS between treatment arms. Secondary objectives include a fully powered analysis of OS, objective tumor response rate, patient-reported outcomes, resource utilization, and toxicity. Tumor specimens for translational research will be obtained from consenting patients before induction treatment, with a second biopsy performed in eligible patients following the induction phase. DISCUSSION: Although using a drug as maintenance therapy that was not used in the induction regimen exposes patients to an agent with a different mechanism of action, evidence suggests that continued use of an agent present in the induction regimen as maintenance therapy enables the identification of patients most likely to benefit from maintenance treatment.

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Background. In cardiopulmonary bypass (CPB) patients, fibrinolysis may enhance postoperative inflammatory response. We aimed to determine whether an additional postoperative dose of antifibrinolytic tranexamic acid (TA) reduced CPB-mediated inflammatory response (IR). Methods. We performed a randomized, double-blind, dose-dependent, parallel-groups study of elective CPB patients receiving TA. Patients were randomly assigned to either the single-dose group (40 mg/Kg TA before CPB and placebo after CPB) or the double-dose group (40 mg/Kg TA before and after CPB). Results. 160 patients were included, 80 in each group. The incident rate of IR was significantly lower in the double-dose-group TA2 (7.5% vs. 18.8% in the single-dose group TA1; P = 0.030). After adjusting for hypertension, total protamine dose and temperature after CPB, TA2 showed a lower risk of IR compared with TA1 [OR: 0.29 (95% CI: 0.10-0.83), (P = 0.013)]. Relative risk for IR was 2.5 for TA1 (95% CI: 1.02 to 6.12). The double-dose group had significantly lower chest tube bleeding at 24 hours [671 (95% CI 549-793 vs. 826 (95% CI 704-949) mL; P = 0.01 corrected-P significant] and lower D-dimer levels at 24 hours [489 (95% CI 437-540) vs. 621(95% CI: 563-679) ng/mL; P = 0.01 corrected-P significant]. TA2 required lower levels of norepinephrine at 24 h [0.06 (95% CI: 0.03-0.09) vs. 0.20(95 CI: 0.05-0.35) after adjusting for dobutamine [F = 6.6; P = 0.014 corrected-P significant]. We found a significant direct relationship between IL-6 and temperature (rho = 0.26; P < 0.01), D-dimer (rho = 0.24; P < 0.01), norepinephrine (rho = 0.33; P < 0.01), troponin I (rho = 0.37; P < 0.01), Creatine-Kinase (rho = 0.37; P < 0.01), Creatine Kinase-MB (rho = 0.33; P < 0.01) and lactic acid (rho = 0.46; P < 0.01) at ICU arrival. Two patients (1.3%) had seizure, 3 patients (1.9%) had stroke, 14 (8.8%) had acute kidney failure, 7 (4.4%) needed dialysis, 3 (1.9%) suffered myocardial infarction and 9 (5.6%) patients died. We found no significant differences between groups regarding these events. Conclusions. Prolonged inhibition of fibrinolysis, using an additional postoperative dose of tranexamic acid reduces inflammatory response and postoperative bleeding (but not transfusion requirements) in CPB patients. A question which remains unanswered is whether the dose used was ideal in terms of safety, but not in terms of effectiveness.

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A ciprofloxacin-resistant Escherichia coli isolate, isolate 1B, was obtained from a urinary specimen of a Canadian patient treated with norfloxacin for infection due to a ciprofloxacin-susceptible isolate, isolate 1A. Both isolates harbored a plasmid-encoded sul1-type integron with qnrA1 and blaVEB-1 genes. Isolate 1B had amino acid substitutions in gyrase and topoisomerase.

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The Wechsler Intelligence Scale for Children-fourth edition (i.e. WISC-IV) recognizes a four-factor scoring structure in addition to the Full Scale IQ (FSIQ) score: Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI) indices. However, several authors suggested that models based on the Cattell-Horn-Carroll (CHC) theory with 5 or 6 factors provided a better fit to the data than does the current four-factor solution. By comparing the current four-factor structure to CHC-based models, this research aimed to investigate the factorial structure and the constructs underlying the WISC-IV subtest scores with French-speaking Swiss children (N = 249). To deal with this goal, confirmatory factor analyses (CFAs) were conducted. Results showed that a CHC-based model with five factors better fitted the French-Swiss data than did the current WISC-IV scoring structure. All together, these results support the hypothesis of the appropriateness of the CHC model with French-speaking children.

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OBJECTIVES: Gouty arthritis patients for whom non-steroidal anti-inflammatory drugs and colchicine are inappropriate have limited treatment options. Canakinumab, an anti-interleukin-1β monoclonal antibody, may be an option for such patients. The authors assessed the efficacy/safety of one dose of canakinumab 150 mg (n=230) or triamcinolone acetonide (TA) 40 mg (n=226) at baseline and upon a new flare in frequently flaring patients contraindicated for, intolerant of, or unresponsive to non-steroidal anti-inflammatory drugs and/or colchicine. Core study co-primary endpoints were pain intensity 72 h postdose (0-100 mm visual analogue scale and time to first new flare. METHODS: Two 12-week randomised, multicentre, active-controlled, double-blind, parallel-group core studies with double-blind 12-week extensions (response in acute flare and in prevention of episodes of re-flare in gout (β-RELIEVED and β-RELIEVED-II)). RESULTS: 82.6% patients had comorbidities. Mean 72-h visual analogue scale pain score was lower with canakinumab (25.0 mm vs 35.7 mm; difference, -10.7 mm; 95% CI -15.4 to -6.0; p<0.0001), with significantly less physician-assessed tenderness and swelling (ORs=2.16 and 2.74; both p≤0.01) versus TA. Canakinumab significantly delayed time to first new flare, reduced the risk of new flares by 62% versus TA (HR: 0.38; 95% CI 0.26 to 0.57) in the core studies and by 56% (HR: 0.44; 95% CI 0.32 to 0.60; both p≤0.0001) over the entire 24-week period, and decreased median C-reactive protein levels (p≤0.0001 at 72 h and 7 days). Over the 24-week period, adverse events were reported in 66.2% (canakinumab) and 52.8% (TA) and serious adverse events were reported in 8.0% (canakinumab) and 3.5% (TA) of patients. Adverse events reported more frequently with canakinumab included infections, low neutrophil count and low platelet count. CONCLUSION: Canakinumab provided significant pain and inflammation relief and reduced the risk of new flares in these patients with acute gouty arthritis.

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Spatial variation in the pattern of natural selection can promote local adaptation and genetic differentiation between populations. Because heritable melanin-based ornaments can signal resistance to environmentally mediated elevation in glucocorticoids, to oxidative stress and parasites, populations may vary in the mean degree of melanic coloration if selection on these phenotypic aspects varies geographically. Within a population of Swiss barn owls (Tyto alba), the size of eumelanic spots is positively associated with survival, immunity and resistance to stress, but it is yet unknown whether Tyto species that face stressful environments evolved towards a darker eumelanic plumage. Because selection regimes vary along environmental gradients, we examined whether melanin-based traits vary clinally and are expressed to a larger extent in the tropics where parasites are more abundant than in temperate zones. To this end, we considered 39 barn owl species distributed worldwide. Barn owl species living in the tropics displayed larger eumelanic spots than those found in temperate zones. This was, however, verified in the northern hemisphere only. Parasites being particularly abundant in the tropics, they may promote the evolution of darker eumelanic ornaments.

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In this study, Ascaris DNA was extracted and sequenced from a medieval archaeological sample in Korea. While Ascaris eggs were confirmed to be of human origin by archaeological evidence, it was not possible to pinpoint the exact species due to close genetic relationships among them. Despite this shortcoming, this is the first Ascaris ancient DNA (aDNA) report from a medieval Asian country and thus will expand the scope of Ascaris aDNA research.

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Supportive breeding is an important tool in conservation management, but its long-term genetic consequences are not well understood. Among the factors that could affect the genetics of the offspring is sperm competition as a consequence of mixed-milt fertilizations - which is still a common practice in many hatcheries. Here, we measured and combined the relevant factors to predict the genetic consequences of various kinds of hatchery-induced sperm competition. We drew a random sample of male Coregonus zugensis (an Alpine whitefish) from a hatchery program and quantified their in vitro sperm potency by integrating sperm velocity during the first minute after activation, and their in vitro milt potency by multiplying sperm potency with milt volume and sperm cell density. We found that not controlling for sperm density and/or milt volume would, at a constant population size, decrease the variance effective number of male breeders N-em by around 40-50%. This loss would decrease with increasing population growth rates. Partial multifactorial breeding and the separate rearing of in total 799 batches of eggs revealed that neither sperm nor milt potency was significantly linked to egg survival. Sperm and milt potency was also not significantly correlated to other potential quality measures such as breeding tubercles or condition factor. However, sperm potency was correlated to male age and milt potency to male growth rate. Our findings suggest that hatchery-induced sperm competition not only increases the loss of genetic variation but may also induce artificial selection, depending on the fertilization protocol. By not equalizing milt volume in multi-male fertilization hatchery managers lose relatively more genetic variation and give fast-growing males a reproductive advantage, while equalizing milt volume reduces the loss of genetic variation and favors younger males who may have fast sperm to compensate for their subdominance at the spawning place. (c) 2007 Elsevier Ltd. All rights reserved.

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The statistical analysis of literary style is the part of stylometry that compares measurable characteristicsin a text that are rarely controlled by the author, with those in other texts. When thegoal is to settle authorship questions, these characteristics should relate to the author’s style andnot to the genre, epoch or editor, and they should be such that their variation between authors islarger than the variation within comparable texts from the same author.For an overview of the literature on stylometry and some of the techniques involved, see for exampleMosteller and Wallace (1964, 82), Herdan (1964), Morton (1978), Holmes (1985), Oakes (1998) orLebart, Salem and Berry (1998).Tirant lo Blanc, a chivalry book, is the main work in catalan literature and it was hailed to be“the best book of its kind in the world” by Cervantes in Don Quixote. Considered by writterslike Vargas Llosa or Damaso Alonso to be the first modern novel in Europe, it has been translatedseveral times into Spanish, Italian and French, with modern English translations by Rosenthal(1996) and La Fontaine (1993). The main body of this book was written between 1460 and 1465,but it was not printed until 1490.There is an intense and long lasting debate around its authorship sprouting from its first edition,where its introduction states that the whole book is the work of Martorell (1413?-1468), while atthe end it is stated that the last one fourth of the book is by Galba (?-1490), after the death ofMartorell. Some of the authors that support the theory of single authorship are Riquer (1990),Chiner (1993) and Badia (1993), while some of those supporting the double authorship are Riquer(1947), Coromines (1956) and Ferrando (1995). For an overview of this debate, see Riquer (1990).Neither of the two candidate authors left any text comparable to the one under study, and thereforediscriminant analysis can not be used to help classify chapters by author. By using sample textsencompassing about ten percent of the book, and looking at word length and at the use of 44conjunctions, prepositions and articles, Ginebra and Cabos (1998) detect heterogeneities that mightindicate the existence of two authors. By analyzing the diversity of the vocabulary, Riba andGinebra (2000) estimates that stylistic boundary to be near chapter 383.Following the lead of the extensive literature, this paper looks into word length, the use of the mostfrequent words and into the use of vowels in each chapter of the book. Given that the featuresselected are categorical, that leads to three contingency tables of ordered rows and therefore tothree sequences of multinomial observations.Section 2 explores these sequences graphically, observing a clear shift in their distribution. Section 3describes the problem of the estimation of a suden change-point in those sequences, in the followingsections we propose various ways to estimate change-points in multinomial sequences; the methodin section 4 involves fitting models for polytomous data, the one in Section 5 fits gamma modelsonto the sequence of Chi-square distances between each row profiles and the average profile, theone in Section 6 fits models onto the sequence of values taken by the first component of thecorrespondence analysis as well as onto sequences of other summary measures like the averageword length. In Section 7 we fit models onto the marginal binomial sequences to identify thefeatures that distinguish the chapters before and after that boundary. Most methods rely heavilyon the use of generalized linear models