91 research outputs found

    Triton photodisintegration in three-dimensional approach

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    Two- and three- particles photodisintegration of the triton is investigated in a three-dimensional (3D) Faddeev approach. For this purpose the Jacobi momentum vectors for three particles system and spin-isospin quantum numbers of the individual nucleons are considered. Based on this picture the three-nucleon Faddeev integral equations with the two-nucleon interaction are formulated without employing the partial wave decomposition. The single nucleon current as well as π\pi- and ρ\rho- like exchange currents are used in an appropriate form to be employed in 3D approach. The exchange currents are derived from AV18 NN force. The two-body t-matrix, Deuteron and Triton wave functions are calculated in the 3D approach by using AV18 potential. Benchmarks are presented to compare the total cross section for the two- and three- particles photodisintegration in the range of Eγ<30MeVE_{\gamma}<30 MeV. The 3D Faddeev approach shows promising results

    Ideal hierarchical secret sharing schemes

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    Hierarchical secret sharing is among the most natural generalizations of threshold secret sharing, and it has attracted a lot of attention from the invention of secret sharing until nowadays. Several constructions of ideal hierarchical secret sharing schemes have been proposed, but it was not known what access structures admit such a scheme. We solve this problem by providing a natural definition for the family of the hierarchical access structures and, more importantly, by presenting a complete characterization of the ideal hierarchical access structures, that is, the ones admitting an ideal secret sharing scheme. Our characterization deals with the properties of the hierarchically minimal sets of the access structure, which are the minimal qualified sets whose participants are in the lowest possible levels in the hierarchy. By using our characterization, it can be efficiently checked whether any given hierarchical access structure that is defined by its hierarchically minimal sets is ideal. We use the well known connection between ideal secret sharing and matroids and, in particular, the fact that every ideal access structure is a matroid port. In addition, we use recent results on ideal multipartite access structures and the connection between multipartite matroids and integer polymatroids. We prove that every ideal hierarchical access structure is the port of a representable matroid and, more specifically, we prove that every ideal structure in this family admits ideal linear secret sharing schemes over fields of all characteristics. In addition, methods to construct such ideal schemes can be derived from the results in this paper and the aforementioned ones on ideal multipartite secret sharing. Finally, we use our results to find a new proof for the characterization of the ideal weighted threshold access structures that is simpler than the existing one.Peer ReviewedPostprint (author's final draft

    Seasonal size variation in the predatory cladoceran Bythotrephes cederstroemii in Lake Michigan

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    1.  Dry weight, body length and spine length were measured for the exotic cladoceran Bythotrephes cederstroemii collected from offshore and inshore stations in southeastern Lake Michigan. Average dry weight of each developmental stage exhibited seasonal variation by a factor of more than 5. 2.  Mean dry weight of Bythotrephes was closely correlated with water temperature. Contrary to the inverse relationship between water temperature and body size frequently observed for other invertebrates, the dry weight of Bythotrephes increased at higher ambient temperatures. 3.  No significant correlation was observed between abundances of major zooplankton taxa and the dry weight of Bythotrephes . An indirect effect of temperature on prey consumption may cause seasonal variation in dry weight of Bythotrephes in Lake Michigan. 4.  Distances between adjacent pairs of barbs, added to the caudal spine with each moult, are significantly shorter in Bythotrephes which produce resting eggs. Less material investment in the exoskeleton of sexually reproducing females was observed in favour of growth and reproduction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74641/1/j.1365-2427.1994.tb00842.x.pd

    Four-body cluster structure of A=710A=7-10 double-Λ\Lambda hypernuclei

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    Energy levels of the double-Λ\Lambda hypernuclei Λ_\Lambda^{}Λ7_\Lambda^7He, Λ_\Lambda^{}Λ7_\Lambda^7Li, Λ_\Lambda^{}Λ8_\Lambda^8Li, Λ_\Lambda^{}Λ9_\Lambda^9Li, Λ_\Lambda^{}Λ9_\Lambda^9Be and Λ_\Lambda^{}Λ10_\Lambda^{10}Be are predicted on the basis of the α+x+Λ+Λ\alpha+x+\Lambda +\Lambda four-body model with x=n,p,d,t,3x=n, p, d, t, ^3He and α\alpha, respectively.Comment: 27 pages (preprint style), 12figures submitted to Phys. Rev.

    Wnt signalling and cancer stem cells

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    [Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e Innovación; SAF2008-0060

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Determinants of penetrance and variable expressivity in monogenic metabolic conditions across 77,184 exomes

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    Hundreds of thousands of genetic variants have been reported to cause severe monogenic diseases, but the probability that a variant carrier develops the disease (termed penetrance) is unknown for virtually all of them. Additionally, the clinical utility of common polygenetic variation remains uncertain. Using exome sequencing from 77,184 adult individuals (38,618 multi-ancestral individuals from a type 2 diabetes case-control study and 38,566 participants from the UK Biobank, for whom genotype array data were also available), we apply clinical standard-of-care gene variant curation for eight monogenic metabolic conditions. Rare variants causing monogenic diabetes and dyslipidemias display effect sizes significantly larger than the top 1% of the corresponding polygenic scores. Nevertheless, penetrance estimates for monogenic variant carriers average 60% or lower for most conditions. We assess epidemiologic and genetic factors contributing to risk prediction in monogenic variant carriers, demonstrating that inclusion of polygenic variation significantly improves biomarker estimation for two monogenic dyslipidemias

    Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

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    EVIDENCE FOR AND EXPLICATION OF THE D-STATE IN FEW-NUCLEON SYSTEMS

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    Une revue de notre compréhension actuelle des propriétés de l'état D dans les systèmes à peu de nucléons, 2H, 3H, 3He, 4He, et 6Li, est présentée. Nous soulignons l'interprétation théorique des dernières évidences expérimentales, en particulier celles obtenues avec des faisceaux polarisés. Nous essayons de donner une présentation théorique cohérente de notre compréhension des constantes de normalisation de la fonction d'onde asymptotique de l'état D pour les systèmes ci-dessus. Le but est de relier les prédictions théoriques du rapport des normalisations des fonctions d'onde asymptotiques de l'état D et de l'état S à la présence de la force tensorielle entre deux nucléons. Nous présentons ensuite ce qui peut être appris, à partir des réactions de capture radiative, concernant l'état D dans les noyaux à peu de nucléons considères, Nous concluons par un résumé de ce que nous savons aujourd'hui de l'état D dans les systèmes à peu de nucléons et nous proposons un développement possible de recherches expérimentales et théoriques.A review is given of our current understanding of the D-state properties of the few-nucleon nuclei 2H, 3H, 3He, 4He, and 6Li. Emphasis is placed on the theoretical interpretation of the latest empirical evidence, especially those experiments involving polarized beams. An attempt is made to provide a coherent theoretical overview of our current understanding of the D-wave asymptotic normalization constants of the above few-nucleon systems. The aim is to tie the theoretical predictions of the ratio of the D-wave to S-wave asymptotic normalization constants to the presence of the two-nucleon tensor force. Following this discussion is an assessment of what has been learned about the D-state in the above few-nucleon nuclei from radiative capture reactions. The review closes with a summary of our current understanding of the D-state in few-nucleon systems and a projection of possible future directions
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