9,110 research outputs found

    Effects of self-consistent rest-ultraviolet colours in semi-empirical galaxy formation models

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    Connecting the observed rest-ultraviolet (UV) luminosities of high-zz galaxies to their intrinsic luminosities (and thus star formation rates) requires correcting for the presence of dust. We bypass a common dust-correction approach that uses empirical relationships between infrared (IR) emission and UV colours, and instead augment a semi-empirical model for galaxy formation with a simple -- but self-consistent -- dust model and use it to jointly fit high-zz rest-UV luminosity functions (LFs) and colour-magnitude relations (MUVM_{\mathrm{UV}}-β\beta). In doing so, we find that UV colours evolve with redshift (at fixed UV magnitude), as suggested by observations, even in cases without underlying evolution in dust production, destruction, absorption, or geometry. The observed evolution in our model arises due to the reduction in the mean stellar age and rise in specific star formation rates with increasing zz. The UV extinction, AUVA_{\mathrm{UV}}, evolves similarly with redshift, though we find a systematically shallower relation between AUVA_{\mathrm{UV}} and MUVM_{\mathrm{UV}} than that predicted by IRX-β\beta relationships derived from z3z \sim 3 galaxy samples. Finally, assuming that high 1600A˚1600 \r{A} transmission (0.6\gtrsim 0.6) is a reliable LAE indicator, modest scatter in the effective dust surface density of galaxies can explain the evolution both in MUVM_{\mathrm{UV}}-β\beta and LAE fractions. These predictions are readily testable by deep surveys with the James Webb Space Telescope.Comment: 14+4 pages, 11+5 figures, accepted for publication in MNRA

    Caring in Kent: Patterns and Profiles, Evidence from the Kent Health and Lifestyle Survey, 2005

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    The ‘Caring in Kent’ report draws on the results of a Kent wide ‘Health and Lifestyle Survey’ conducted in 2005; this included a module on caring. This enables a picture of caring to be reported including: a general profile of carers, levels and types of care-giving, carers’ health, and the level and types of support they receive. ‘Carers provide unpaid care by looking after an ill, frail or disabled family member, friend or partner’. The increasingly recognised importance of the role of the ‘informal carer’ is - in good part - due to the rising proportion of older people in the UK population. Not only do people live longer but many experience a number of chronic conditions; these require support from family members if the older person is to remain living in the community

    Parthenolide eliminates leukemia-initiating cell populations and improves survival in xenografts of childhood acute lymphoblastic leukemia

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    Key Points First report demonstrating in vivo elimination of multiple LIC populations from childhood ALL cases using animal models. In vivo models of leukemia are essential for drug evaluation studies.</jats:p

    Effects of dietary fibre and the provision of a foraging substrate on the welfare of sows in different grouping systems

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    End of project reportThere are no clear guidelines on how best to meet the EU legislative requirement (Council Directive 2001/88/EC) that pregnant sows and gilts should be provided with sufficient amounts of bulky or high fibre diets and high energy food to satisfy hunger and the motivation to chew. Therefore the aim of this project was to investigate the effect of increasing dietary fibre levels and providing access to a foraging substrate on the welfare of sows housed in dynamic and static groups. To achieve this a review paper was compiled and three experiments were conducted. The aim of the review paper was to assess the effectiveness of increasing dietary fibre levels on the welfare of pregnant sows. Previous research found that increasing dietary fibre levels decrease activity levels and the performance of stereotypic behaviour, and increase resting behaviour. However, high fibre diets do not appear to reduce aggression between group-housed pregnant sows. The research clearly showed that the effectiveness of high fibre diets is influenced by the source of fibre, with soluble fibres being more effective in reducing stereotypic behaviours than insoluble fibres. However the optimum fibrous ingredient, or combination of ingredients, and the optimum dietary inclusion rate for these ingredients remains unclear

    Lifting classes for the fixed point theory of nn-valued maps

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    The theory of lifting classes and the Reidemeister number of single-valued maps of a finite polyhedron XX is extended to nn-valued maps by replacing liftings to universal covering spaces by liftings with codomain an orbit configuration space, a structure recently introduced by Xicot\'encatl. The liftings of an nn-valued map ff split into self-maps of the universal covering space of XX that we call lift-factors. An equivalence relation is defined on the lift-factors of ff and the number of equivalence classes is the Reidemeister number of ff. The fixed point classes of ff are the projections of the fixed point sets of the lift-factors and are the same as those of Schirmer. An equivalence relation is defined on the fundamental group of XX such that the number of equivalence classes equals the Reidemeister number. We prove that if XX is a manifold of dimension at least three, then algebraically the orbit configuration space approach is the same as one utilizing the universal covering space. The Jiang subgroup is extended to nn-valued maps as a subgroup of the group of covering transformations of the orbit configuration space and used to find conditions under which the Nielsen number of an nn-valued map equals its Reidemeister number. If an nn-valued map splits into nn single-valued maps, then its nn-valued Reidemeister number is the sum of their Reidemeister numbers.Comment: near complete rewrite from previous versio

    Representations of linear dual rate system via single SISO LTI filter, conventional sampler and block sampler

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    In this brief, it is proved that a linear dual-rate system can be represented via a series cascade of: 1) a conventional expander, a single-input single-output (SISO) linear time-invariant (LTI) filter and a block decimator, or 2) a block expander, an SISO LTI filter and a conventional decimator. Hence, incompatible nonuniform filter banks could achieve perfect reconstruction via LTI filters, conventional samplers and block samplers without expanding the input-output dimension of a subsystem of linear dual-rate systems or converting the nonuniform filter banks to uniform filter banks. The main advantage of the proposed representations is to avoid complicated design of the circuit layout caused by connecting subsystems with large input-output dimension or a lot of subsystems togethe

    How to Turn Your Kitchen into a Lab

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    Preserving Chile

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    The best way to preserve chile depends on how you plan to use it and your available storage space. Frozen or canned chile is best for chile rellenos and salsas. Stews can use frozen, canned or dried chile. Dried chile has minimal storage requirements and is light-weight for taking on camping trips. Pickled chiles can be used on a relish plate or as an ingredient in other dishes

    Storage of Dry Milk

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    Publication gives instructions on how to properly store dry milk

    What Are the Risks in Foods and What Can You Do About Them

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