940 resultados para Taylor, Jane, d. 1865.
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Arnol'd's second hydrodynamical stability theorem, proven originally for the two-dimensional Euler equations, can establish nonlinear stability of steady flows that are maxima of a suitably chosen energy-Casimir invariant. The usual derivations of this theorem require an assumption of zero disturbance circulation. In the present work an analogue of Arnol'd's second theorem is developed in the more general case of two-dimensional quasi-geostrophic flow, with the important feature that the disturbances are allowed to have non-zero circulation. New nonlinear stability criteria are derived, and explicit bounds are obtained on both the disturbance energy and potential enstrophy which are expressed in terms of the initial disturbance fields. While Arnol'd's stability method relies on the second variation of the energy-Casimir invariant being sign-definite, the new criteria can be applied to cases where the second variation is sign-indefinite because of the disturbance circulations. A version of Andrews' theorem is also established for this problem.
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We describe the CHARMe project, which aims to link climate datasets with publications, user feedback and other items of "commentary metadata". The system will help users learn from previous community experience and select datasets that best suit their needs, as well as providing direct traceability between conclusions and the data that supported them. The project applies the principles of Linked Data and adopts the Open Annotation standard to record and publish commentary information. CHARMe contributes to the emerging landscape of "climate services", which will provide climate data and information to influence policy and decision-making. Although the project focuses on climate science, the technologies and concepts are very general and could be applied to other fields.
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We analysed single nucleotide polymorphisms (SNPs) tagging the genetic variability of six candidate genes (ATF6, FABP1, LPIN2, LPIN3, MLXIPL and MTTP) involved in the regulation of hepatic lipid metabolism, an important regulatory site of energy balance for associations with body mass index (BMI) and changes in weight and waist circumference. We also investigated effect modification by sex and dietary intake. Data of 6,287 individuals participating in the European prospective investigation into cancer and nutrition were included in the analyses. Data on weight and waist circumference were followed up for 6.9 ± 2.5 years. Association of 69 tagSNPs with baseline BMI and annual changes in weight as well as waist circumference were investigated using linear regression analysis. Interactions with sex, GI and intake of carbohydrates, fat as well as saturated, monounsaturated and polyunsaturated fatty acids were examined by including multiplicative SNP-covariate terms into the regression model. Neither baseline BMI nor annual weight or waist circumference changes were significantly associated with variation in the selected genes in the entire study population after correction for multiple testing. One SNP (rs1164) in LPIN2 appeared to be significantly interacting with sex (p = 0.0003) and was associated with greater annual weight gain in men (56.8 ± 23.7 g/year per allele, p = 0.02) than in women (-25.5 ± 19.8 g/year per allele, p = 0.2). With respect to gene-nutrient interaction, we could not detect any significant interactions when accounting for multiple testing. Therefore, out of our six candidate genes, LPIN2 may be considered as a candidate for further studies.
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We establish an uniform factorial decay estimate for the Taylor approximation of solutions to controlled differential equations. Its proof requires a factorial decay estimate for controlled paths which is interesting in its own right.
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Uppsatsen behandlar Gustafsbergs barnhusinrättning, en skola för pojkar som dessutom var Sveriges första internatskola. Syftet med uppsatsen är att undersöka vilka kriterier man hade på undervisningen på barnhusinrättningen från 1860-talets mitt och fram till mitten på 1880-talet samt vilka eleverna var som vistades där under den perioden. Detta görs utifrån frågeställningarna hur barnhusinrättningens stadgar såg ut under senare delen av 1800-talet, hur en kurs/läroplan under den aktuella tidsperioden såg ut och hur ämnena var fördelade, samt vilken bakgrund de elever som gick på barnhusinrättningen under den aktuella tidsperioden kunde ha och vad de ägnade sig åt efter examen från skolan.För att kunna genomföra undersökningen användes tillgängligt arkivmaterial angående Gustafsbergs barnhusinrättning, framför allt på arkivet på Gustafsbergsstiftelsen men även på Bohusläns föreningsarkiv.Undersökningen visade att stadgan och kursplanen angav att eleverna skulle delas in i tre klasser, en nedre, en mellersta och en övre. Utifrån denna indelning placerades elever i åldrarna mellan 6-16 in, dock rådde särskilda krav på blivande elever som skulle bli antagna till skolan och likaså på intagna elever för att de skulle kunna examineras. Examinationerna kontrollerades utförligt. Undervisningen på skolan skulle motsvara det statliga läroverkets fem lägre klasser. Läroämnena som skulle ingå i undervisningen och dess fördelning är tydlig både i stadgan och i kursplanerna. Ämnena skulle fördelas på 32 timmar i veckan, då tillkom ytterligare timmar för vidare studier vilket innebar ett ganska pressat schema. Diverse olika kriterier ställdes således på de olika klasserna, men också på lärarna vilka förväntades följa uppsatta riktlinjer för hur de skulle arbeta när det handlade om tidsfördelning bland klasserna och gällande olika ämnen. Kvaliteten på undervisningen och lärarna eftersträvades av skolan att hålla hög klass för att ge eleverna chans till vidare studier.Vilken bakgrund, och hemförhållanden, de elever som gick på barnhusinrättningen kom från blir tydlig med hjälp av barnhuslängden och ansökningar till barnhuset. Alla barnen hade gemensamt att de var fattiga och således kom från påvra förhållanden, de var alla hemmahörande i Bohuslän. Många gånger var det den enda lösningen de anhöriga kunde se för att ge barnet en chans till en framtid. Eleverna i undersökningen gick, i de allra flesta fallen, vidare till olika yrken som till exempel inom handel och kontor, länsman och sjöman. Vidare studier förekom också liksom emigrering till Amerika.
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Before 1989 all braconid wasps were thought to be parasitoids, but in that year the first phytophagous species was reported. Subsequently, a few other examples of phytophagy have been discovered, most of which are species of Allorhogas in the subfamily Doryctinae. Until now, all demonstrated examples of phytophagy in this genus have been as gall inducers in the fruits of Fabaceae. Here we describe a new species from Costa Rica, Allorhogas conostegia Marsh and Shaw, and provide evidence that it forms galls in the fruits of Conostegia xalapensis (Melastomataceae). We also provide information on the phenology of the plant and of the galls and the effects of the galls on the host plant, and we discuss the potential species richness of Allorhogas in the Neotropics.
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We report on a measurement of the B-d(0) mixing frequency and the calibration of an opposite-side flavor tagger in the D0 experiment. Various properties associated with the b quark on the opposite side of the reconstructed B meson are combined using a likelihood-ratio method into a single variable with enhanced tagging power. Its performance is tested with data, using a large sample of reconstructed semileptonic B ->mu(DX)-X-0 and B ->mu(DX)-X-* decays, corresponding to an integrated luminosity of approximately 1 fb(-1). The events are divided into groups depending on the value of the combined tagging variable, and an independent analysis is performed in each group. Combining the results of these analyses, the overall effective tagging power is found to be epsilon D-2=(2.48 +/- 0.21(-0.06)(+0.08))%. The measured B-d(0) mixing frequency Delta m(d)=0.506 +/- 0.020(stat)+/- 0.016(syst) ps(-1) is in good agreement with the world average value.
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We report a study of the decay B-s(0)->(DsDs(*))-D-(*) using a data sample corresponding to 1.3 fb(-1) of integrated luminosity collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. One D-s((*)) meson was partially reconstructed in the decay D-s ->phi mu nu, and the other D-s((*)) meson was identified using the decay D-s ->phi pi where no attempt was made to distinguish D-s and D-s(*) states. For the branching fraction Br(B-s(0)->(DsDs(*))-D-(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039(-0.017)(+0.019)(stat)(-0.015)(+0.016)(syst). This was subsequently used to make the most precise estimate of the width difference Delta Gamma(CP)(s) in the B-s(0)-(B)over bar(s)(0) system: Delta Gamma(CP)(s)/Gamma(s)=0.079(-0.035)(+0.038)(stat)(-0.030)(+0.031)(syst).
Measurement of semileptonic branching fractions of B mesons to narrow D-** states - art. no. 1711803
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Using the data accumulated in 2002-2004 with the D0 detector in proton-antiproton collisions at the Fermilab Tevatron collider with a center-of-mass energy of 1.96 TeV, the branching fractions of the decays B ->(D) over bar (0)(1)(2420)mu(+)nu(mu)X and B ->(D) over bar (*0)(2)(2460)mu(+)nu(mu)X and their ratio have been measured: B (b) over bar -> B)xB(B -> (D) over bar (0)(1)mu(+)nu(mu)X)xB((D) over bar (0)(1)-> D(*-)pi(+))=[0.087 +/- 0.007(stat)+/- 0.014(syst)]%; B((b) over bar -> B)xB(B ->(D) over bar (*0)(2)mu(+)nu(mu)X)xB((D) over bar (*0)(2)-> D(*-)pi(+))=[0.035 +/- 0.007(stat)+/- 0.008(syst)]% and [B(B ->(D) over bar (*0)(2)mu(+)nu(mu)X)xB((D) over bar (*0)(2)-> D(*-)pi(+))]/[B(B ->(D) over bar (0)(1)mu(+)nu(mu)X)xB((D) over bar (0)(1)-> D(*-)pi(+))]=0.39 +/- 0.09(stat)+/- 0.12(syst), where the charge conjugated states are always implied.
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Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)
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A data sample corresponding to an integrated luminosity of 2.1 fb(-1) collected by the D phi detector at the Fermilab Tevatron Collider was analyzed to search for squarks and gluinos produced in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. No evidence for the production of such particles was observed in topologies involving jets and missing transverse energy, and 95% C.L. lower limits of 379 GeV and 308 GeV were set on the squark and gluino masses, respectively, within the framework of minimal supergravity with tan beta = 3, A(0) = 0, and mu < 0. The corresponding previous limits are improved by 54 GeV and 67 GeV. (c) 2008 Elsevier B.V. All rights reserved.