4,252 research outputs found

    Nesting and nighttime behaviours of captive chimpanzees (Pan troglodytes)

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    Abstract Studies of nesting behaviours of free-ranging apes typically focus on ecological variables such as preferred tree species and areas within the home range, heights of nests, and nest group sizes. However, nesting in captive apes is rarely studied, despite the ubiquity of this sleep-related behaviour. The paucity of field data is often attributed to the inherent difficulty in observing what is essentially a nighttime behaviour. Captive settings can provide researchers with an ideal opportunity to record nesting and sleep-related behaviours, yet such research on captive apes is also scant. Topics addressed include current practices in zoos regarding conditions for sleep in great apes, the potential effects of social and environmental factors on sleep site selection, the motor patterns involved in nest construction, preferred nesting structures and substrates, and nocturnal behaviours. This thesis documented and empirically tested hypotheses concerning nest-related activities in captive chimpanzees, with an aim to generate practical recommendations for enclosure design, sleeping areas, sleeping structures, and nesting substrates that have implications for the welfare of captive apes. As with the few reports that already exist, most chimpanzees in this research frequently constructed night nests. When building a nest, some techniques appeared to be universal across individuals and groups, where others were group-specific or occasionally characteristic of only certain individuals. An experiment showed that specific materials are preferred over others for nest building. Many chimpanzees appeared to express persistent preferences for particular sleeping sites, and for some this was to maintain proximity to kin or other closely bonded individuals. In one group, individual sleeping site preferences changed across seasons, although again this was subject to individual differences. Video analyses of nighttime behaviours demonstrated that, although nests/sleep sites are primarily used for rest subsequent to retirement, a number of social and non-social activities were performed throughout the night. In conjunction with analysis of postural and orientation shifts, these data are unique in describing the nocturnal behaviours of chimpanzees out with a laboratory setting. Several aspects of nest-related behaviours showed a high degree of inter-and intra-group variation. Although this cautions against generalising findings across captive populations, research of this type has applied implications for the management of captive ape species, and can add to our as-yet meagre understanding of their nest and sleep-related behaviours

    The determination of the direction of the optic axis of uniaxial crystalline materials

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    The birefringence of crystalline substances in general, and of sapphire in particular, is described. A test is described whose purpose is to determine the direction of the optic axis of a cylindrically machined single crystal of sapphire. This test was performed on the NASA Lewis sapphire cylinder and it was found that the optic axis made an angle of 18 deg with the axis of symmetry of the cylinder

    Laser diffraction particle sizing: Instrument probe volume relocation and elongation

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    The effective probe volume of laser diffraction particle sizing instruments depends on many instrument parameters. In particular the probe volume axial boundaries and its location along laser beam are essentially defined by the onset of a vignetting effect where light scattered at large angles from small particles misses the transform lens. This vignetting effect results in a probe volume that must be inconveniently close to the lens in order to detect smaller diameter particles (less than 100 micrometers). With the addition of an appropriately designed Keplerian telescope, the probe volume may be relocated and elongated. The theory of operation of this supplemental optical system is described. Design considerations for these supplemental optical systems are described, including recommendations for lens specifications, assembly and use. An image transfer system is described which has been designed for use on a Malvern 2600HSD instrument. Experimental validation of this image transfer system is described

    Protocol for a national monthly survey of alcohol use in England with 6-month follow-up: 'The Alcohol Toolkit Study'.

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    Timely tracking of national patterns of alcohol consumption is needed to inform and evaluate strategies and policies aimed at reducing alcohol-related harm. Between 2014 until at least 2017, the Alcohol Toolkit Study (ATS) will provide such tracking data and link these with policy changes and campaigns. By virtue of its connection with the 'Smoking Toolkit Study' (STS), links will also be examined between alcohol and smoking-related behaviour

    Multi-modal locomotion:from animal to application

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    Responsibility without legal authority? Tackling alcohol-related health harms through licensing and planning policy in local government.

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    BACKGROUND: The power to influence many social determinants of health lies within local government sectors that are outside public health's traditional remit. We analyse the challenges of achieving health gains through local government alcohol control policies, where legal and professional practice frameworks appear to conflict with public health action. METHODS: Current legislation governing local alcohol control in England and Wales is reviewed and analysed for barriers and opportunities to implement effective population-level health interventions. Case studies of local government alcohol control practices are described. RESULTS: Addressing alcohol-related health harms is constrained by the absence of a specific legal health licensing objective and differences between public health and legal assessments of the relevance of health evidence to a specific place. Local governments can, however, implement health-relevant policies by developing local evidence for alcohol-related health harms; addressing cumulative impact in licensing policy statements and through other non-legislative approaches such as health and non-health sector partnerships. Innovative local initiatives-for example, minimum unit pricing licensing conditions-can serve as test cases for wider national implementation. CONCLUSIONS: By combining the powers available to the many local government sectors involved in alcohol control, alcohol-related health and social harms can be tackled through existing local mechanisms

    Reversal of glucocorticoid resistance in paediatric acute lymphoblastic leukaemia is dependent on restoring BIM expression.

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    BackgroundAcute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy. Glucocorticoids form a critical component of chemotherapy regimens and resistance to glucocorticoid therapy is predictive of poor outcome. We have previously shown that glucocorticoid resistance is associated with upregulation of the oncogene C-MYC and failure to induce the proapoptotic gene BIM.MethodsA high-throughput screening (HTS) campaign was carried out to identify glucocorticoid sensitisers against an ALL xenograft derived from a glucocorticoid-resistant paediatric patient. Gene expression analysis was carried out using Illumina microarrays. Efficacy, messenger RNA and protein analysis were carried out by Resazurin assay, reverse transcription-PCR and immunoblotting, respectively.ResultsA novel glucocorticoid sensitiser, 2-((4,5-dihydro-1H-imidazol-2-yl)thio)-N-isopropyl-N-phenylacetamide (GCS-3), was identified from the HTS campaign. The sensitising effect was specific to glucocorticoids and synergy was observed in a range of dexamethasone-resistant and dexamethasone-sensitive xenografts representative of B-ALL, T-ALL and Philadelphia chromosome-positive ALL. GCS-3 in combination with dexamethasone downregulated C-MYC and significantly upregulated BIM expression in a glucocorticoid-resistant ALL xenograft. The GCS-3/dexamethasone combination significantly increased binding of the glucocorticoid receptor to a novel BIM enhancer, which is associated with glucocorticoid sensitivity.ConclusionsThis study describes the potential of the novel glucocorticoid sensitiser, GCS-3, as a biological tool to interrogate glucocorticoid action and resistance

    On the flow of kaons produced in relativistic heavy ion collisions

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    We investigate the different contributions to the in-plane flow of K+ mesons observed recently by the FOPI collaboration in the reaction Ni(1.93 AGeV)+Ni. Due to the kinematics of the three body phase space decay the flow of kaons produced in baryon-baryon interactions is smaller than that of the baryons in the entrance channel. On the contrary, in pi N interactions the flow of the sources and of the kaons are identical. Therefore the total kaon flow depends on the relative number of Delta N -> K+ and pi N -> K+ reactions and hence on the lifetime of the Delta, in addition to the already known dependence on the potential interaction interaction of the kaons with the nuclear environment.Comment: 11 pages, 10 figures, submitted to NP
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