397 research outputs found

    Evidence for particle-hole excitations in the triaxial strongly-deformed well of ^{163}Tm

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    Two interacting, strongly-deformed triaxial (TSD) bands have been identified in the Z = 69 nucleus ^{163}Tm. This is the first time that interacting TSD bands have been observed in an element other than the Z = 71 Lu nuclei, where wobbling bands have been previously identified. The observed TSD bands in ^{163}Tm appear to be associated with particle-hole excitations, rather than wobbling. Tilted-Axis Cranking (TAC) calculations reproduce all experimental observables of these bands reasonably well and also provide an explanation for the presence of wobbling bands in the Lu nuclei, and their absence in the Tm isotopes.Comment: 13 pages, 7 figure

    On the energy functional on Finsler manifolds and applications to stationary spacetimes

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    In this paper we first study some global properties of the energy functional on a non-reversible Finsler manifold. In particular we present a fully detailed proof of the Palais--Smale condition under the completeness of the Finsler metric. Moreover we define a Finsler metric of Randers type, which we call Fermat metric, associated to a conformally standard stationary spacetime. We shall study the influence of the Fermat metric on the causal properties of the spacetime, mainly the global hyperbolicity. Moreover we study the relations between the energy functional of the Fermat metric and the Fermat principle for the light rays in the spacetime. This allows us to obtain existence and multiplicity results for light rays, using the Finsler theory. Finally the case of timelike geodesics with fixed energy is considered.Comment: 23 pages, AMSLaTeX. v4 matches the published versio

    Convex domains of Finsler and Riemannian manifolds

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    A detailed study of the notions of convexity for a hypersurface in a Finsler manifold is carried out. In particular, the infinitesimal and local notions of convexity are shown to be equivalent. Our approach differs from Bishop's one in his classical result (Bishop, Indiana Univ Math J 24:169-172, 1974) for the Riemannian case. Ours not only can be extended to the Finsler setting but it also reduces the typical requirements of differentiability for the metric and it yields consequences on the multiplicity of connecting geodesics in the convex domain defined by the hypersurface.Comment: 22 pages, AMSLaTex. Typos corrected, references update

    Antigenic Variation of the Dengue Virus 2 Genotypes Impacts the Neutralization Activity of Human Antibodies in Vaccinees

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    Martinez et al. demonstrate that dengue virus serotype 2 (DENV2) genetic variation modulates neutralizing antibody activity from infection and vaccination. This observation underlines that genotypic variation impacts dengue virus 2 evasion from humoral immunity, suggesting that intraserotype genotypic variation should be considered in designing dengue vaccines. © 2020 The Author(s); Dengue virus (DENV) infects an estimated 390 million people each year worldwide. As tetravalent DENV vaccines have variable efficacy against DENV serotype 2 (DENV2), we evaluated the role of genetic diversity within the pre-membrane (prM) and envelope (E) proteins of DENV2 on vaccine performance. We generated a recombinant DENV2 genotype variant panel with contemporary prM and E isolates that are representative of global genetic diversity. The DENV2 genotype variants differ in growth kinetics, morphology, and virion stability. Importantly, the DENV2 genotypic variants are differentially neutralized by monoclonal antibodies, polyclonal serum neutralizing antibodies from DENV2-infected human subjects, and vaccine-elicited antibody responses from the TV003 NIH DENV2 monovalent and DENV tetravalent vaccines. We conclude that DENV2 prM and E genetic diversity significantly modulates antibody neutralization activity. These findings have important implications for dengue vaccines, which are being developed under the assumption that intraserotype variation has minimal impact on neutralizing antibodies

    A tetravalent live attenuated dengue virus vaccine stimulates balanced immunity to multiple serotypes in humans

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    The four-dengue virus (DENV) serotypes infect several hundred million people annually. For the greatest safety and efficacy, tetravalent DENV vaccines are designed to stimulate balanced protective immunity to all four serotypes. However, this has been difficult to achieve. Clinical trials with a leading vaccine demonstrated that unbalanced replication and immunodominance of one vaccine component over others can lead to low efficacy and vaccine enhanced severe disease. The Laboratory of Infectious Diseases at the National Institutes of Health has developed a live attenuated tetravalent DENV vaccine (TV003), which is currently being tested in phase 3 clinical trials. Here we report, our study to determine if TV003 stimulate balanced and serotype-specific (TS) neutralizing antibody (nAb) responses to each serotype. Serum samples from twenty-one dengue-naive individuals participated under study protocol CIR287 (ClinicalTrials.gov NCT02021968) are analyzed 6 months after vaccination. Most subjects (76%) develop TS nAbs to 3 or 4 DENV serotypes, indicating immunity is induced by each vaccine component. Vaccine-induced TS nAbs map to epitopes known to be targets of nAbs in people infected with wild type DENVs. Following challenge with a partially attenuated strain of DENV2, all 21 subjects are protected from the efficacy endpoints. However, some vaccinated individuals develop post challenge nAb boost, while others mount post-challenge antibody responses that are consistent with sterilizing immunity. TV003 vaccine induced DENV2 TS nAbs are associated with sterilizing immunity. Our results indicate that nAbs to TS epitopes on each serotype may be a better correlate than total levels of nAbs currently used for guiding DENV vaccine development

    Inequalities in health and community-oriented social work: lessons from Cuba?

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    Social justice is, as the World Health Organization Commission on Social Determinants of Health (WHO CSDH, 2008) reminds us, ‘a matter of life and death’. While the stark differences in mortality rates and life expectancy between rich and poor countries might be the most obvious example of this, it is also true that ‘Within countries, the differences in life chances are dramatic and are seen in all countries – even the richest’ (WHO CSDH, 2008: 26). As the Commission demonstrates, the roots of these inequities lie in social conditions, suggesting an important role for social work in this area. Unfortunately, the Commission says very little about the type of social work that might be appropriate: nevertheless, the report does provide fresh impetus to the debate about what social workers might contribute to tackling health inequalities. In this article, we suggest that a community-oriented approach to social work is required. In making a case for this, we review the progress of the government’s drive to reduce inequalities in England,1 arguing that this has, thus far, been largely unsuccessful because it has primarily been pursued through health-care services, while addressing the wider (social) determinants of health has been a secondary consideration. In contrast, we offer the example of Cuban community-oriented social work (COSW) which has helped maintain population health at a level that stands comparison with much wealthier nations, despite the hardships and inequalities which followed economic collapse in the 1990s. In many ways the Cuban situation is unusual, perhaps unique, so we are not arguing that Cuban social work methods can be readily transferred. Rather, we suggest that, in the neglected field of tackling health inequalities, social workers can learn from the general approach taken in Cuba. To establish the context of this discussion, we begin by defining key concepts: COSW itself, health inequalities and inequity, the health gap and the health gradient

    Effect of lactation stage and concurrent pregnancy on milk composition in the bottlenose dolphin

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    Although many toothed whales (Cetacea: Odontoceti) lactate for 2–3 years or more, it is not known whether milk composition is affected by lactation stage in any odontocete species. We collected 64 pooled milk samples spanning 1–30 months postpartum from three captive bottlenose dolphins Tursiops truncatus. Milks were assayed for water, fat, crude protein (TN × 6.38) and sugar; gross energy was calculated. Ovulation and pregnancy were determined via monitoring of milk progesterone. Based on analysis of changes in milk composition for each individual dolphin, there were significant increases (P<0.05) in fat (in all three dolphins) and crude protein (in two of three), and a decrease (P<0.05) in water (in two of three) over the course of lactation, but the sugar content did not change. In all three animals, the energy content was positively correlated with month of lactation, but the percentage of energy provided by crude protein declined slightly but significantly (P<0.05). At mid-lactation (7–12 months postpartum, n=17), milk averaged 73.0±1.0% water, 12.8±1.0% fat, 8.9±0.5% crude protein, 1.0±0.1% sugar, 1.76±0.09 kcal g−1 (=7.25 kJ g−1) and 30.3±1.3% protein:energy per cent. This protein:energy per cent was surprisingly high compared with other cetaceans and in relation to the growth rates of calves. Milk progesterone indicated that dolphins ovulated and conceived between 413 and 673 days postpartum, following an increase in milk energy density. The significance of these observed compositional changes to calf nutrition will depend on the amounts of milk produced at different stages of lactation, and how milk composition and yield are influenced by sampling procedure, maternal diet and maternal condition, none of which are known

    Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

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    The Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb−1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2ÎČ\beta measurement from B0→J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0→J/ψKS0)=(1.83±0.28)×10−5BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date

    Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

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    Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) and the direct CP asymmetry in B0 -> K*0 gamma

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    The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 phi gamma has been measured using an integrated luminosity of 1.0 fb-1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of sqrt(s)=7 TeV. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.23 +/- 0.06(stat.) +/- 0.04(syst.) +/- 0.10(fs/fd), where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for BR(B0 -> K*0 gamma), the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.5 +/- 0.4) x 10^{-5}. The direct CP asymmetry in B0 -> K*0 gamma decays has also been measured with the same data and found to be A(CP)(B0 -> K*0 gamma) = (0.8 +/- 1.7(stat.) +/- 0.9(syst.))%. Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations.Comment: 21 pages, 3 figues, 4 table
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