2,711 research outputs found

    Options for managing human threats to high seas biodiversity

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    Areas beyond national jurisdiction (ABNJ) constitute 61% of the world's oceans and are collectively managed by countries under the United Nations Convention on the Law of the Sea (UNCLOS). Growing concern regarding the deteriorating state of the oceans and ineffective management of ABNJ has resulted in negotiations to develop an international legally binding instrument (ILBI) for the conservation and sustainable use of biodiversity beyond national jurisdiction under UNCLOS. To inform these negotiations, we identified existing and emerging human activities and influences that affect ABNJ and evaluated management options available to mitigate the most pervasive, with highest potential for impact and probability of emergence. The highest-ranking activities and influences that affect ABNJ were fishing/hunting, maritime shipping, climate change and its associated effects, land-based pollution and mineral exploitation. Management options are diverse and available through a variety of actors, although their actions are not always effective. Area-based management tools (ABMTs), including marine protected areas (MPAs), were the only consistently effective option to mitigate impacts across high-ranked activities and influences. However, addressing land-based pollution will require national action to prevent this at its source, and MPAs offer only a partial solution for climate change. A new ABNJ ILBI could help unify management options and actors to conserve marine biodiversity and ensure sustainable use. Incorporating a mechanism to establish effective ABMTs into the ILBI will help deliver multiple objectives based on the ecosystem approach

    Structural parameterizations for boxicity

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    The boxicity of a graph GG is the least integer dd such that GG has an intersection model of axis-aligned dd-dimensional boxes. Boxicity, the problem of deciding whether a given graph GG has boxicity at most dd, is NP-complete for every fixed d≥2d \ge 2. We show that boxicity is fixed-parameter tractable when parameterized by the cluster vertex deletion number of the input graph. This generalizes the result of Adiga et al., that boxicity is fixed-parameter tractable in the vertex cover number. Moreover, we show that boxicity admits an additive 11-approximation when parameterized by the pathwidth of the input graph. Finally, we provide evidence in favor of a conjecture of Adiga et al. that boxicity remains NP-complete when parameterized by the treewidth.Comment: 19 page

    Construction of the Views oN Infant Sleep (VNIS) Questionnaire

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    Parents' beliefs about infant sleep behaviour vary over time and across cultures. No validated instrument exists to understand parents' pre- and postnatal views on infant sleep behaviours, which may influence their caregiving decisions. The Views oN Infant Sleep Questionnaire (VNIS) will be a tool to assess parents' beliefs in order to facilitate tailored perinatal care, increase the reliability of postnatal self-report measures, allow for cross-cultural comparisons, and provide a baseline for researchers to use in longitudinal studies. We recruited an online sample of 971 female participants who were resident in the United Kingdom, at least 28 weeks pregnant, and at least 18 years of age. The initial questionnaire consisted of 31 questions about infant independence, night-waking, infant feeding, touch, and safety, and items were rated on a 5-point Likert scale. The item pool was reduced to 12 using principal component analysis and a structure was found for the three components “Closeness”, “Independence”, and “Night-waking”. Overall, these results suggest that the VNIS can provide a brief scale to measure different aspects of individuals' beliefs about infant sleep. In further research the VNIS needs to be validated with a confirmatory factor analysis in another sample, and to be tested as a cross-cultural instrument

    Axion monodromy in a model of holographic gluodynamics

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    The low energy field theory for N type IIA D4-branes at strong 't Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the θ\theta angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of "axion monodromy" for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of θ\theta. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with θ\theta, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes -- nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk -- which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings.Comment: 43 pages, 10 figures. v2: references update

    An introduction to genetic quality in the context of sexual selection

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    This special issue of Genetica brings together empirical researchers and theoreticians to present the latest on the evolutionary ecology of genetic quality in the context of sexual selection. The work comes from different fields of study including behavioral ecology, quantitative genetics and molecular genetics on a diversity of organisms using different approaches from comparative studies, mathematical modeling, field studies and laboratory experiments. The papers presented in this special issue primarily focus on genetic quality in relation to ( 1) sources of genetic variation, ( 2) polyandry, ( 3) new theoretical developments and ( 4) comprehensive reviews
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