30 research outputs found

    Studies of the Cabbibo-Suppressed Decays D+→π0ℓ+ÎœD^+ \to \pi^0 \ell^+ \nu and D+→ηe+ÎœeD^+ \to \eta e^+ \nu_e

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    Using 4.8 fb−1^{-1} of data taken with the CLEO II detector, the branching fraction for the Cabibbo-suppressed decay D+→π0ℓ+ÎœD^+\to\pi^0\ell^+\nu measured relative to the Cabibbo favored decay D+→K0ˉℓ+ÎœD^+\to\bar{K^0}\ell^+\nu is found to be 0.046±0.014±0.0170.046\pm 0.014\pm 0.017. Using VcsV_{cs} and VcdV_{cd} from unitarity constraints, we determine ∣f+π(0)/f+K(0)∣2=0.9±0.3±0.3| f_+^{\pi}(0)/f_+^K(0)|^2=0.9\pm 0.3\pm 0.3 We also present a 90% confidence level upper limit for the branching ratio of the decay D+→ηe+ÎœeD^+ \to \eta e^+\nu_e relative to that for D+→π0e+ÎœeD^+ \to \pi^0 e^+\nu_e of 1.5.Comment: 10 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    The energy spectrum of cosmic rays beyond the turn-down around 10^17 eV as measured with the surface detector of the Pierre Auger Observatory

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    We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays

    TRY plant trait database – enhanced coverage and open access

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    Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Nanophononics: state of the art and perspectives

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    Disfunção hormonal em lesÔes não hipofisårias das regiÔes selar e periselar Hormonal dysfunction of nonpituitary lesions from midline and perisellar area

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    OBJETIVO: Analisar a disfunção hormonal prĂ©-operatĂłria, clĂ­nica e/ou laboratorial, das lesĂ”es intracranianas nĂŁo hipofisĂĄrias da linha mĂ©dia e regiĂŁo peri-selar. MÉTODO: Foram analisados 44 pacientes com lesĂ”es intracranianas nĂŁo hipofisĂĄrias, com exames de imagem (tomografia computadorizada ou ressonĂąncia magnĂ©tica) e dosagens hormonais basais; 16 tinham provas de função hipotĂĄlamo-hipofisĂĄria (megateste) prĂ©-operatĂłrios. Esses pacientes foram divididos em dois grupos: Grupo I - 34 lesĂ”es da linha mĂ©dia: 11 craniofaringiomas, 8 meningiomas, 3 germinomas, 3 tumores do seio esfenoidal, 2 sĂ­ndromes sela vazia, 2 astrocitomas pilocĂ­ticos, 1 aneurisma gigante, 2 mucoceles, 1 divertĂ­culo do III ventrĂ­culo e 1 cisto da bolsa de Rathke; Grupo II - 10 lesĂ”es da regiĂŁo peri-selar: 9 meningiomas e 1 aneurisma gigante. RESULTADOS: No grupo I, 25/34 (73,5%) pacientes apresentavam dĂ©ficit hormonal laboratorial (14 sem clĂ­nica evidente), 18/34 (52,9%) hiperprolactinemia (apenas 5 com galactorrĂ©ia) e, dos 15 megatestes realizados nesse grupo, 8 (53,3%) mostraram deficiĂȘncia do hormĂŽnio de crescimento (GH); 3 (8,8 %) pacientes apresentaram diabetes insipidus central (DIC) prĂ©-operatĂłrio. No grupo II, 6/10 (60%) pacientes apresentavam dĂ©ficit hormonal laboratorial (5 sem clĂ­nica evidente), 1/10 (10%) hiperprolactinemia e 1 deficiĂȘncia de GH (Ășnico megateste feito nesse grupo); nenhum paciente apresentou DIC prĂ©-operatĂłrio. CONCLUSÃO: A presença de manifestaçÔes clĂ­nicas inespecĂ­ficas ou pouco valorizadas nĂŁo indica ausĂȘncia de disfunção hormonal laboratorial; na presente sĂ©rie, 19/38 (50%) pacientes com alteraçÔes laboratoriais, nĂŁo apresentavam manifestaçÔes clĂ­nicas. Disfunção hormonal Ă© frequente em lesĂ”es nĂŁo hipofisĂĄrias selares e peri-selares, especialmente, aquelas envolvendo a linha mĂ©dia.<br>OBJECTIVE: To analyse clinical and/or laboratorial preoperative hormonal dysfunction , of the nonpituitary intracranial lesions from midline and parasellar area. METHOD: Forty-four patients were evaluated with nonpituitary intracranial lesions, who had images studies (computed tomography or magnetic resonance) and preoperative basal hormonal level; 16 had preoperative hypothalamus-hypophysial function tests (megatests). These patients were divided in two groups. Group I - 34 lesions from midline: 11 craniopharyngiomas, 8 meningiomas, 3 germinomas, 3 tumors of sphenoid sinus, 2 empty sella syndrome, 2 pylocitic astrocytomas, 1 giant aneurysm, 2 mucoceles, 1 III ventricle diverticulum and 1 Rathke's cleft cyst; Group II - 10 lesions from parasellar area: 9 meningiomas and 1 giant aneurysm. RESULTS: In group I, 25/34 (73.5%) patients showed laboratorial hormonal deficit (14 without clinical manifestations) 18/34 (52.9%) hyperprolactinemia (5 with galactorreia) and 8 (53.3%) showed growth hormone deficiency in 15 megatests avaliable in this group; 3 (8.8 %) patients presented central diabetes insipidus (CDI). In group II, 6/10 (60%) patients showed laboratorial hormonal deficit (5 without clinical manifestations), 1 (10%) hyperprolactinemia and 1 growth hormone deficiency (single megatest realized in this group); no patient had preoperative CID. CONCLUSIONS: The presence of nonspecific or poorly valorized clinical manifestations, does not indicate absence of hormonal dysfunction; in this present serie, 19/38 (50%) patients with laboratorial abnormalities, didn't show clinical manifestations. Hormonal dysfunction is frequent in sellar and perisellar nonpituitary lesions, specially involving midline
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