134 research outputs found

    Emerging nuclear collectivity in 124130^{124-130}Te

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    The emergence of nuclear collectivity near doubly-magic 132^{132}Sn was explored along the stable, even-even 124130^{124-130}Te isotopes. Preliminary measurements of the B(E2;41+21+)B(E2;4^{+}_{1}\rightarrow2^{+}_{1}) transition strengths are reported from Coulomb excitation experiments primarily aimed at measuring the gg factors of the 41+4^{+}_{1} states. Isotopically enriched Te targets were excited by 198-205 MeV 58^{58}Ni beams. A comparison of transition strengths obtained is made to large-scale shell-model calculations with successes and limitations discussed.Comment: 5 pages, 3 figures, Submitted to Proceedings HIAS 2019, EPJ Web of Conference

    Shape polarization in the tin isotopes near N=60N=60 from precision gg-factor measurements on short-lived 11/211/2^- isomers

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    The gg factors of 11/211/2^- isomers in semimagic 109^{109}Sn and 111^{111}Sn (isomeric lifetimes τ=2.9(3)\tau = 2.9(3) ns and τ=14.4(7)\tau = 14.4(7) ns, respectively) were measured by an extension of the Time Differential Perturbed Angular Distribution technique, which uses \LaBr detectors and the hyperfine fields of a gadolinium host to achieve precise measurements in a new regime of short-lived isomers. The results, g(11/2;109Sn)=0.186(8)g(11/2^-; {^{109}\textrm{Sn}}) = -0.186(8) and g(11/2;111Sn)=0.214(4)g(11/2^-; {^{111}\textrm{Sn}}) = -0.214(4), are significantly lower in magnitude than those of the 11/211/2^- isomers in the heavier isotopes and depart from the value expected for a near pure neutron h11/2h_{11/2} configuration. Broken-symmetry density functional theory calculations applied to the sequence of 11/211/2^- states reproduce the magnitude and location of this deviation. The g(11/2)g(11/2^-) values are affected by shape core polarization; the odd 0h11/20h_{11/2} neutron couples to Jπ=2+,4+,6+...J^{\pi}=2^+,4^+,6^+... configurations in the weakly-deformed effective core, causing a decrease in the gg-factor magnitudes.Comment: 8 pages, 7 figures. Accepted in Physics Letters

    Evidence for shape coexistence and superdeformation in 24Mg

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    The E0 transition depopulating the first-excited 0+ state in 24Mg has been observed for the first time, and the E0 transition strength determined by electron-positron pair and γ-ray spectroscopy measurements performed using the Super-e pair spectrometer. The E0 transition strength is ρ2×103=380(70). A two-state mixing model implies a deformation of the first-excited 0+ state of β2≈1 and a change in the mean-square charge radius of Δ〈r2〉≈1.9fm2, which suggests a significant shape change between the ground state and first-excited 0+ state in 24Mg. The observed E0 strength gives direct evidence of shape coexistence and superdeformation in 24Mg, bringing this nucleus into line with similar behaviour in nearby N=Z nuclei. This result agrees with recent theoretical work on the cluster nature of 24Mg and has potential ramifications for nuclear reactions of astrophysical importance

    Should Research Ethics Encourage the Production of Cost-Effective Interventions?

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    This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs

    Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

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    OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

    Levers and leverage points for pathways to sustainability

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    Humanity is on a deeply unsustainable trajectory. We are exceeding planetary boundaries and unlikely to meet many international sustainable development goals and global environmental targets. Until recently, there was no broadly accepted framework of interventions that could ignite the transformations needed to achieve these desired targets and goals. As a component of the IPBES Global Assessment, we conducted an iterative expert deliberation process with an extensive review of scenarios and pathways to sustainability, including the broader literature on indirect drivers, social change and sustainability transformation. We asked, what are the most important elements of pathways to sustainability? Applying a social–ecological systems lens, we identified eight priority points for intervention (leverage points) and five overarching strategic actions and priority interventions (levers), which appear to be key to societal transformation. The eight leverage points are: (1) Visions of a good life, (2) Total consumption and waste, (3) Latent values of responsibility, (4) Inequalities, (5) Justice and inclusion in conservation, (6) Externalities from trade and other telecouplings, (7) Responsible technology, innovation and investment, and (8) Education and knowledge generation and sharing. The five intertwined levers can be applied across the eight leverage points and more broadly. These include: (A) Incentives and capacity building, (B) Coordination across sectors and jurisdictions, (C) Pre-emptive action, (D) Adaptive decision-making and (E) Environmental law and implementation. The levers and leverage points are all non-substitutable, and each enables others, likely leading to synergistic benefits. Transformative change towards sustainable pathways requires more than a simple scaling-up of sustainability initiatives—it entails addressing these levers and leverage points to change the fabric of legal, political, economic and other social systems. These levers and leverage points build upon those approved within the Global Assessment's Summary for Policymakers, with the aim of enabling leaders in government, business, civil society and academia to spark transformative changes towards a more just and sustainable world. A free Plain Language Summary can be found within the Supporting Information of this article.Fil: Chan, Kai M. A.. University of British Columbia; CanadáFil: Boyd, David R.. University of British Columbia; CanadáFil: Gould, Rachelle. University of Vermont; Estados UnidosFil: Jetzkowitz, Jens. Staatliches Museum fur Naturkunde Stuttgart; AlemaniaFil: Liu, Jianguo. Michigan State University; Estados UnidosFil: Muraca, Bárbara. University of Oregon; Estados UnidosFil: Naidoo, Robin. University of British Columbia; CanadáFil: Beck, Paige. University of British Columbia; CanadáFil: Satterfield, Terre. University of British Columbia; CanadáFil: Selomane, Odirilwe. Stellenbosch University; SudáfricaFil: Singh, Gerald G.. University of British Columbia; CanadáFil: Sumaila, Rashid. University of British Columbia; CanadáFil: Ngo, Hien T.. Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services; AlemaniaFil: Boedhihartono, Agni Klintuni. University of British Columbia; CanadáFil: Agard, John. The University Of The West Indies; Trinidad y TobagoFil: de Aguiar, Ana Paula D.. Stockholms Universitet; SueciaFil: Armenteras, Dolors. Universidad Nacional de Colombia; ColombiaFil: Balint, Lenke. BirdLife International; Reino UnidoFil: Barrington-Leigh, Christopher. Mcgill University; CanadáFil: Cheung, William W. L.. University of British Columbia; CanadáFil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Driscoll, John. University of British Columbia; CanadáFil: Esler, Karen. Stellenbosch University; SudáfricaFil: Eyster, Harold. University of British Columbia; CanadáFil: Gregr, Edward J.. University of British Columbia; CanadáFil: Hashimoto, Shizuka. The University Of Tokyo; JapónFil: Hernández Pedraza, Gladys Cecilia. The World Economy Research Center; CubaFil: Hickler, Thomas. Goethe Universitat Frankfurt; AlemaniaFil: Kok, Marcel. PBL Netherlands Environmental Assessment Agency; Países BajosFil: Lazarova, Tanya. PBL Netherlands Environmental Assessment Agency; Países BajosFil: Mohamed, Assem A. A.. Central Laboratory for Agricultural Climate; EgiptoFil: Murray-Hudson, Mike. University Of Botswana; BotsuanaFil: O'Farrell, Patrick. University of Cape Town; SudáfricaFil: Palomo, Ignacio. Basque Centre for Climate Change; EspañaFil: Saysel, Ali Kerem. Boğaziçi University; TurquíaFil: Seppelt, Ralf. Martin-universität Halle-wittenberg; AlemaniaFil: Settele, Josef. German Centre for Integrative Biodiversity Research-iDiv; AlemaniaFil: Strassburg, Bernardo. International Institute for Sustainability, Estrada Dona Castorina; BrasilFil: Xue, Dayuan. Minzu University Of China; ChinaFil: Brondízio, Eduardo S.. Indiana University; Estados Unido
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