128 research outputs found

    Beautiful Mirrors and Precision Electroweak Data

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    The Standard Model (SM) with a light Higgs boson provides a very good description of the precision electroweak observable data coming from the LEP, SLD and Tevatron experiments. Most of the observables, with the notable exception of the forward-backward asymmetry of the bottom quark, point towards a Higgs mass far below its current experimental bound. The disagreement, within the SM, between the values for the weak mixing angle as obtained from the measurement of the leptonic and hadronic asymmetries at lepton colliders, may be taken to indicate new physics contributions to the precision electroweak observables. In this article we investigate the possibility that the inclusion of additional bottom-like quarks could help resolve this discrepancy. Two inequivalent assignments for these new quarks are analysed. The resultant fits to the electroweak data show a significant improvement when compared to that obtained in the SM. While in one of the examples analyzed, the exotic quarks are predicted to be light, with masses below 300 GeV, and the Higgs tends to be heavy, in the second one the Higgs is predicted to be light, with a mass below 250 GeV, while the quarks tend to be heavy, with masses of about 800 GeV. The collider signatures associated with the new exotic quarks, as well as the question of unification of couplings within these models and a possible cosmological implication of the new physical degrees of freedom at the weak scale are also discussed.Comment: 21 pages, 4 embedded postscript figures, LaTeX. Two minor corrections performe

    Measurement of the forward-backward asymmetries for charm- and bottom-quark pair productions at <s><\sqrt{s}>=58GeV with electron tagging

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    We have measured, with electron tagging, the forward-backward asymmetries of charm- and bottom-quark pair productions at =58.01GeV, based on 23,783 hadronic events selected from a data sample of 197pb1^{-1} taken with the TOPAZ detector at TRISTAN. The measured forward-backward asymmetries are AFBc=0.49±0.20(stat.)±0.08(sys.)A_{FB}^c = -0.49 \pm 0.20(stat.) \pm 0.08 (sys.) and AFBb=0.64±0.35(stat.)±0.13(sys.)A_{FB}^b = -0.64 \pm 0.35(stat.) \pm 0.13 (sys.), which are consistent with the standard model predictions.Comment: 19 pages, Latex format (article), 5 figures included. to be published in Phys. Lett.

    Germline polymorphisms in SIPA1 are associated with metastasis and other indicators of poor prognosis in breast cancer

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    INTRODUCTION: There is growing evidence that heritable genetic variation modulates metastatic efficiency. Our previous work using a mouse mammary tumor model has shown that metastatic efficiency is modulated by the GTPase-activating protein encoded by Sipa1 ('signal-induced proliferation-associated gene 1'). The aim of this study was to determine whether single nucleotide polymorphisms (SNPs) within the human SIPA1 gene are associated with metastasis and other disease characteristics in breast cancer. METHOD: The study population (n = 300) consisted of randomly selected non-Hispanic Caucasian breast cancer patients identified from a larger population-based series. Genomic DNA was extracted from peripheral leukocytes. Three previously described SNPs within SIPA1 (one within the promoter [-313G>A] and two exonic [545C>T and 2760G>A]) were characterized using SNP-specific PCR. RESULTS: The variant 2760G>A and the -313G>A allele were associated with lymph node involvement (P = 0.0062 and P = 0.0083, respectively), and the variant 545C>T was associated with estrogen receptor negative tumors (P = 0.0012) and with progesterone negative tumors (P = 0.0339). Associations were identified between haplotypes defined by the three SNPs and disease progression. Haplotype 3 defined by variants -313G>A and 2760G>A was associated with positive lymph node involvement (P = 0.0051), and haplotype 4 defined by variant 545C>T was associated with estrogen receptor and progesterone receptor negative status (P = 0.0053 and P = 0.0199, respectively). CONCLUSION: Our findings imply that SIPA1 germline polymorphisms are associated with aggressive disease behavior in the cohort examined. If these results hold true in other populations, then knowledge of SIPA1 SNP genotypes could potentially enhance current staging protocols

    The Validity and Structure of Culture-Level Personality Scores: Data From Ratings of Young Adolescents

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    We examined properties of culture-level personality traits in ratings of targets (N=5,109) ages 12 to 17 in 24 cultures. Aggregate scores were generalizable across gender, age, and relationship groups and showed convergence with culture-level scores from previous studies of self-reports and observer ratings of adults, but they were unrelated to national character stereotypes. Trait profiles also showed cross-study agreement within most cultures, 8 of which had not previously been studied. Multidimensional scaling showed that Western and non-Western cultures clustered along a dimension related to Extraversion. A culture-level factor analysis replicated earlier findings of a broad Extraversion factor but generally resembled the factor structure found in individuals. Continued analysis of aggregate personality scores is warranted. This article is a US Government work and is in the public domain in the USA.Fil: McCrae, Robert R.. National Institute on Ageing; CanadáFil: Terracciano, Antonio. National Institute on Ageing; CanadáFil: De Fruyt, Filip. University of Ghent; BélgicaFil: De Bolle, Marleen. University of Ghent; BélgicaFil: Gelfand, Michele J.. University of Maryland; Estados UnidosFil: Costa Jr., Paul T.. National Institute on Ageing; CanadáFil: Klinkosz, Waldemar. The John Paul II Catholic University of Lublin; PoloniaFil: Knežević, Goran. Belgrade University; SerbiaFil: Leibovich de Figueroa, Nora. Universidad de Buenos Aires; ArgentinaFil: Löckenhoff, Corinna E.. Cornell University; Estados UnidosFil: Martin, Thomas A.. Susquehanna University; Estados UnidosFil: Marušić, Iris. Institute for Social Research; CroaciaFil: Mastor, Khairul Anwar. Universiti Kebangsaan Malaysia; MalasiaFil: Nakazato, Katsuharu. Iwate Prefectural University; AfganistánFil: Nansubuga, Florence. Makerere University; UgandaFil: Porrata, Jose. No especifíca;Fil: Purić, Danka. Belgrade University; SerbiaFil: Realo, aAnu. University of Tartu; EstoniaFil: Reátegui, Norma. Universidad Peruana Cayetano Heredia; PerúFil: Rolland, Jean Pierre. Universite Paris Ouest Nanterre la Defense; FranciaFil: Schmidt, Vanina Ines. Universidad de Buenos Aires. Facultad de Psicología. Instituto de Investigaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sekowski, Andrzej. The John Paul II Catholic University of Lublin; PoloniaFil: Shakespeare Finch, Jane. Queensland University of Technology; AustraliaFil: Shimonaka, Yoshiko. Bunkyo Gakuin University; JapónFil: Simonetti, Franco. Pontificia Universidad Católica de Chile; ChileFil: Siuta, Jerzy. Jagiellonian University;Fil: Szmigielska, Barbara. Jagiellonian University;Fil: Vanno, Vitanya. Srinakharinwirot University; TailandiaFil: Wang, Lei. Peking University; ChinaFil: Yik, Michelle. The Hong Kong University of Science and Technology; Hong Kon

    Actin polymerization stabilizes α4β1 integrin anchors that mediate monocyte adhesion

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    Leukocytes arrested on inflamed endothelium via integrins are subjected to force imparted by flowing blood. How leukocytes respond to this force and resist detachment is poorly understood. Live-cell imaging with Lifeact-transfected U937 cells revealed that force triggers actin polymerization at upstream α4β1 integrin adhesion sites and the adjacent cortical cytoskeleton. Scanning electron microscopy revealed that this culminates in the formation of structures that anchor monocyte adhesion. Inhibition of actin polymerization resulted in cell deformation, displacement, and detachment. Transfection of dominant-negative constructs and inhibition of function or expression revealed key signaling steps required for upstream actin polymerization and adhesion stabilization. These included activation of Rap1, phosphoinositide 3-kinase γ isoform, and Rac but not Cdc42. Thus, rapid signaling and structural adaptations enable leukocytes to stabilize adhesion and resist detachment forces

    Big Losses Lead to Irrational Decision-Making in Gambling Situations: Relationship between Deliberation and Impulsivity

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    In gambling situations, we found a paradoxical reinforcing effect of high-risk decision-making after repeated big monetary losses. The computerized version of the Iowa Gambling Task (Bechara et al., 2000), which contained six big loss cards in deck B', was conducted on normal healthy college students. The results indicated that the total number of selections from deck A' and deck B' decreased across trials. However, there was no decrease in selections from deck B'. Detailed analysis of the card selections revealed that some people persisted in selecting from the “risky” deck B' as the number of big losses increased. This tendency was prominent in self-rated deliberative people. However, they were implicitly impulsive, as revealed by the matching familiar figure test. These results suggest that the gap between explicit deliberation and implicit impulsivity drew them into pathological gambling

    Carbohydrate-active enzymes from the zygomycete fungus Rhizopus oryzae: a highly specialized approach to carbohydrate degradation depicted at genome level

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    <p>Abstract</p> <p>Background</p> <p><it>Rhizopus oryzae </it>is a zygomycete filamentous fungus, well-known as a saprobe ubiquitous in soil and as a pathogenic/spoilage fungus, causing Rhizopus rot and mucomycoses.</p> <p>Results</p> <p>Carbohydrate Active enzyme (CAZy) annotation of the <it>R. oryzae </it>identified, in contrast to other filamentous fungi, a low number of glycoside hydrolases (GHs) and a high number of glycosyl transferases (GTs) and carbohydrate esterases (CEs). A detailed analysis of CAZy families, supported by growth data, demonstrates highly specialized plant and fungal cell wall degrading abilities distinct from ascomycetes and basidiomycetes. The specific genomic and growth features for degradation of easily digestible plant cell wall mono- and polysaccharides (starch, galactomannan, unbranched pectin, hexose sugars), chitin, chitosan, β-1,3-glucan and fungal cell wall fractions suggest specific adaptations of <it>R. oryzae </it>to its environment.</p> <p>Conclusions</p> <p>CAZy analyses of the genome of the zygomycete fungus <it>R. oryzae </it>and comparison to ascomycetes and basidiomycete species revealed how evolution has shaped its genetic content with respect to carbohydrate degradation, after divergence from the Ascomycota and Basidiomycota.</p

    Personality profiles of cultures: aggregate personality traits

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    Personality profiles of cultures can be operationalized as the mean trait levels of culture members. College students from 51 cultures rated an individual from their country whom they knew well (N = 12, 156). Aggregate scores on Revised NEO Personality Inventory scales generalized across age and gender groups, approximated the individual-level Five-Factor Model, and correlated with aggregate self-report personality scores and other culture-level variables. Results were not attributable to national differences in economic development or to acquiescence. Geographical differences in scale variances and mean levels were replicated, with Europeans and Americans generally scoring higher in Extraversion than Asians and Africans. Findings support the rough scalar equivalence of NEO-PI-R factors and facets across cultures, and suggest that aggregate personality profiles provide insight into cultural differences
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