Search for the Decays B^0 -> D^{(*)+} D^{(*)-}

Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one candidate signal event, with an expected background of 0.022 +/- 0.011 events. This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) = (5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0 -> D^{*+} D^{*-}) D^{*\pm} D^\mp and B^0 -> D^+ D^-, no significant excess of signal above the expected background level is seen, and we calculate the 90% CL upper limits on the branching fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+ D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter

ΛΛˉ\Lambda\bar{\Lambda} Production in Two-Photon Interactions at CLEO

Using the CLEO detector at the Cornell $e^+e^-$ storage ring, CESR, we study the two-photon production of $\Lambda \bar{\Lambda}$, making the first observation of $\gamma \gamma \to \Lambda \bar{\Lambda}$. We present the cross-section for $\gamma \gamma \to \Lambda \bar{\Lambda}$ as a function of the $\gamma \gamma$ center of mass energy and compare it to that predicted by the quark-diquark model.Comment: 10 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Shifting Attention From Theory to Practice in Philosophy of Biology

Traditional approaches in philosophy of biology focus attention on biological concepts, explanations, and theories, on evidential support and inter-theoretical relations. Newer approaches shift attention from concepts to conceptual practices, from theories to practices of theorizing, and from theoretical reduction to reductive retooling. In this article, I describe the shift from theory-focused to practice-centered philosophy of science and explain how it is leading philosophers to abandon fundamentalist assumptions associated with traditional approaches in philosophy of science and to embrace scientific pluralism. This article comes in three parts, each illustrating the shift from theory-focused to practice-centered epistemology. The first illustration shows how shifting philosophical attention to conceptual practice reveals how molecular biologists succeed in identifying coherent causal strands within systems of bewildering complexity. The second illustration suggests that analyzing how a multiplicity of alternative models function in practice provides an illuminating approach for understanding the nature of theoretical knowledge in evolutionary biology. The third illustration demonstrates how framing reductionism in terms of the reductive retooling of practice offers an informative perspective for understanding why putting DNA at the center of biological research has been incredibly productive throughout much of biology. Each illustration begins by describing how traditional theory-focused philosophical approaches are laden with fundamentalist assumptions and then proceeds to show that shifting attention to practice undermines these assumptions and motivates a philosophy of scientific pluralism

Observation of the Decay Ds+→ωπ+D_{s}^{+}\to \omega\pi^{+}

Using e+e- annihilation data collected by the CLEO~II detector at CESR, we have observed the decay Ds+ to omega pi+. This final state may be produced through the annihilation decay of the Ds+, or through final state interactions. We find a branching ratio of [Gamma(Ds+ to omega pi+)/Gamma(Ds+ to eta pi+)]=0.16+-0.04+-0.03, where the first error is statistical and the second is systematic.Comment: 9 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Analyses and Comparison of Imputation-Based Association Methods

Genotype imputation methods have become increasingly popular for recovering untyped genotype data. An important application with imputed genotypes is to test genetic association for diseases. Imputation-based association test can provide additional insight beyond what is provided by testing on typed tagging SNPs only. A variety of effective imputation-based association tests have been proposed. However, their performances are affected by a variety of genetic factors, which have not been well studied. In this study, using both simulated and real data sets, we investigated the effects of LD, MAF of untyped causal SNP and imputation accuracy rate on the performances of seven popular imputation-based association methods, including MACH2qtl/dat, SNPTEST, ProbABEL, Beagle, Plink, BIMBAM and SNPMStat. We also aimed to provide a comprehensive comparison among methods. Results show that: 1). imputation-based association tests can boost signals and improve power under medium and high LD levels, with the power improvement increasing with strengthening LD level; 2) the power increases with higher MAF of untyped causal SNPs under medium to high LD level; 3). under low LD level, a high imputation accuracy rate cannot guarantee an improvement of power; 4). among methods, MACH2qtl/dat, ProbABEL and SNPTEST perform similarly and they consistently outperform other methods. Our results are helpful in guiding the choice of imputation-based association test in practical application

Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV

This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

Parallel Adaptive Divergence among Geographically Diverse Human Populations

Few genetic differences between human populations conform to the classic model of positive selection, in which a newly arisen mutation rapidly approaches fixation in one lineage, suggesting that adaptation more commonly occurs via moderate changes in standing variation at many loci. Detecting and characterizing this type of complex selection requires integrating individually ambiguous signatures across genomically and geographically extensive data. Here, we develop a novel approach to test the hypothesis that selection has favored modest divergence at particular loci multiple times in independent human populations. We find an excess of SNPs showing non-neutral parallel divergence, enriched for genic and nonsynonymous polymorphisms in genes encompassing diverse and often disease related functions. Repeated parallel evolution in the same direction suggests common selective pressures in disparate habitats. We test our method with extensive coalescent simulations and show that it is robust to a wide range of demographic events. Our results demonstrate phylogenetically orthogonal patterns of local adaptation caused by subtle shifts at many widespread polymorphisms that likely underlie substantial phenotypic diversity

Сельскохозяйственная кооперация Урала за 1926-27 хозяйственный год и за I квартал 1927-28 г.: материалы к III собранию уполномоченных Уралселькустсоюза

0|7|Общие условия и итоги работы с.-х. кооперации за отчетный период [c. 7]0|11|Направление и темп кооперирования [c. 11]0|13|Союзное строительство [c. 13]0|13|Социальный состав пайщиков и его регулирование [c. 13]0|16|Итоги перевыборной кампании [c. 16]0|17|Аппарат системы [c. 17]0|18|Направление и характер организационной работы системы [c. 18]0|19|Культработа [c. 19]0|20|Массовая работа [c. 20]0|20|Колхозное строительство [c. 20]0|22|Кредитная работа [c. 22]0|26|Торгово-посредническая деятельность [c. 26]0|30|Финансы [c. 30]0|33|Производственная деятельность [c. 33]0|34|Агрикультурная работа [c. 34]0|35|Кустарно-промысловая кооперация в системе сел.-хоз. кооперации [c. 35]0|38|Состояние и работа системы в I кв. 1927-28 г. [c. 38]0|39|Рост колхозного движения [c. 39]0|40|Товарооборот с.-х. кооперации [c. 40]0|41|Финансовое состояние системы [c. 41]0|41|Итоги и перспективы [c. 41]0|45|Таблицы [c. 45]1|45|Сельско-хозяйственная кооперация в 1926-28 году [c. 45]2|45|Организационное состояние [c. 45]3|46|Сеть кооперативов в районах деятельности союзов сельско-хоз. и куст. пром. кооперации Уралобласти по видам [c. 46]3|47|Число всех кооперативов и членов в них в районах деятельности отдельных союзов сел.-хоз. и куст.-пром. кооперации и процент кооперированности хозяйств по округам [c. 47]3|49|Социально-имущественный состав членов-пайщиков сел.-хоз. кредитных товариществ на 1 октября 1927 года [c. 49]3|50|Состав правлений и ревкомиссий низовой сети сельско-хозяйственной кооперации до и после перевыборов 1927-28 г. [c. 50]2|51|Финансовое состояние [c. 51]3|52|Сводные балансы по отдельным видам сельско-хозяйственных кооперативов на 1-Х-1926 г. и 1-Х-1927 г. [c. 52]3|53|Сводные балансы сельско-хозяйственных кредитных товариществ на 1 октября 1927 года по союзам [c. 53]3|54|Балансы (нетто) союзов сел.-хоз. куст.-пром. кооперации на 1 октября 26 г. и на 1 октября 27 г. [c. 54]3|56|Балансы Уралселькустсоюза на 1-Х-1926 г. и 1-Х-1927 года [c. 56]3|57|Использование фондов кооперирования бедноты в 1926-27 г. и создание таковых из прибылей 1926-27 г. по низовой сети [c. 57]2|59|Хозяйственная работа и ее результаты [c. 59]3|61|Оброт по продаже товаров отдельных звеньев сельско-хозяйственной кооперации по сортиментным группам за 1926-27 год [c. 61]3|62|Распределение торговых оборотов сель.-хоз, кредитных товариществ по контрагентам в 1926-27 г. [c. 62]3|63|Общеторговые расходы сел.-хоз. кредитных товариществ за 1926-27 год [c. 63]3|64|Доходы сельско-хозяйственных кредитных товариществ за 1926-1927 год [c. 64]3|65|Агрономические предприятия низовой сети сель.-хоз кооперации на 1-Х 1927 год [c. 65]3|66|Промышленные предприятия низовой сети сельско-хозяйственной кооперации на 1-Х-1927 г. [c. 66]3|67|Товарооборот союзов сельско-хозяйственной и кустарно-промысловой кооперации за 1926-27 год [c. 67]3|68|Покупка и продажа товаров по снабжению союзами с.-х. куст. промысл. кооперации с разбивкой на контрагентов в 1926-27 г. [c. 68]3|69|Покупка и продажа товаров по сбыту союзами сел.-хоз. куст. пром. кооперации с разбивкой на контрагентов в 1926-27 году [c. 69]3|70|Доходы и обще-торговые расходы союзов сел.-хоз. и куст.-пром. кооперации в 1926-1927 году [c. 70]3|71|Наложение на себестоимость товаров в 1927-28 году [c. 71]2|72|Сельско-хозяйственная кооперация в I квартале 1927-28 года [c. 72]3|73|Сеть кооперативов в районе деятельности окружных и районных союзов, входящих в систему областного союза сел.-хоз. кооперации на 1-Х-27 г. и 1-I-1928 г. [c. 73]3|74|Число всех кооперативов и членов в них по отдельным союзам и процент кооперированости хозяйств по округам [c. 74]3|75|Сводные балансы с.-хоз. кредитных товариществ на 1 октября 27 г. и 1 января 1928 г. [c. 75]3|76|Сводные балансы (нетто) 1-ти окружных и районных союзов сел.-хоз. кооперации на 1-Х-27 и 1-I -28 г. [c. 76]3|78|Балансы (нетто) Уралселькустсоюза на 1/I-27 г., 1/I-28 г. и 1-IV-28 г. [c. 78]3|80|Оборот по продаже товаров союзов сельско-хозяйственной кооперации за I кварта 1927-28 года [c. 80]3|81|Обще-торговые расходы союзов сел.-хоз. кооперации в I квартале 1927-28 года [c. 81]3|82|Товарооборот и обще-торговые расходы союзов сел.-хоз. кооперации [c. 82]2|83|Текущие кампании [c. 83]3|84|Паевая кампания [c. 84]3|85|Перевыборная кампания 1927-28 г. [c. 85]3|85|Общие перевыборные собрания членов пайщиков сел.-хоз. кооперации в 1927-1928 году [c. 85]3|86|Перевыборные собрания уполномоченных сельско-хозяйственных к-вово в 1917-28 году [c. 86]0|87|Пояснения к таблицам [c. 87]0|90|Оглавление [c. 90

Balancing selection is common in the extended MHC region but most alleles with opposite risk profile for autoimmune diseases are neutrally evolving

<p>Abstract</p> <p>Background</p> <p>Several susceptibility genetic variants for autoimmune diseases have been identified. A subset of these polymorphisms displays an opposite risk profile in different autoimmune conditions. This observation open interesting questions on the evolutionary forces shaping the frequency of these alleles in human populations.</p> <p>We aimed at testing the hypothesis whereby balancing selection has shaped the frequency of opposite risk alleles.</p> <p>Results</p> <p>Since balancing selection signatures are expected to extend over short genomic portions, we focused our analyses on 11 regions carrying putative functional polymorphisms that may represent the disease variants (and the selection targets). No exceptional nucleotide diversity was observed for <it>ZSCAN23</it>, <it>HLA-DMB</it>, <it>VARS2</it>, <it>PTPN22</it>, <it>BAT3</it>, <it>C6orf47</it>, and <it>IL10</it>; summary statistics were consistent with evolutionary neutrality for these gene regions. Conversely, <it>CDSN/PSORS1C1</it>, <it>TRIM10/TRIM40</it>, <it>BTNL2</it>, and <it>TAP2 </it>showed extremely high nucleotide diversity and most tests rejected neutrality, suggesting the action of balancing selection. For <it>TAP2 </it>and <it>BTNL2 </it>these signatures are not secondary to linkage disequilibrium with HLA class II genes. Nonetheless, with the exception of variants in <it>TRIM40 </it>and <it>CDSN</it>, our data suggest that opposite risk SNPs are not selection targets but rather have accumulated as neutral variants.</p> <p>Conclusion</p> <p>Data herein indicate that balancing selection is common within the extended MHC region and involves several non-HLA loci. Yet, the evolutionary history of most SNPs with an opposite effect for autoimmune diseases is consistent with evolutionary neutrality. We suggest that variants with an opposite effect on autoimmune diseases should not be considered a distinct class of disease alleles from the evolutionary perspective and, in a few cases, the opposite effect on distinct diseases may derive from complex haplotype structures in regions with high genetic diversity.</p