501 research outputs found

    Designing capacity-building in e-learning expertise: Challenges and strategies

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    This research study looks at how organizations in developing countries perceive the challenge of building capacity in e-learning expertise. Data was collected on six such organizations, and a range of perceived rationales and constraints were identified. The paper hypothesizes a four-part framework to define the e-learning capacity gaps that these circumstances appear to represent: the 'instructional design capacity gap', the 'production capacity gap', the 'tutorial capacity gap' and the 'community building gap'. The framework is used to re-examine the data to explore the ways in which the organizations' e-learning activities might constitute strategic responses to the hypothesized capacity gaps

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    The PHENIX Experiment at RHIC

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    The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

    Lambda Hyperons in 2 A*GeV Ni + Cu Collisions

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    A sample of Lambda's produced in 2 A*GeV Ni + Cu collisions has been obtained with the EOS Time Projection Chamber at the Bevalac. Low background in the invariant mass distribution allows for the unambiguous demonstration of Lambda directed flow. The transverse mass spectrum at mid-rapidity has the characteristic shoulder-arm shape of particles undergoing radial transverse expansion. A linear dependence of Lambda multiplicity on impact parameter is observed, from which a total Lambda + Sigma^0 production cross section of $112 +/- 24 mb is deduced. Detailed comparisons with the ARC and RVUU models are made.Comment: Revised version accepted for publication in Phys. Lett.

    Does the anticipatory behaviour of chickens communicate reward quality?

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    The anticipatory behaviour of animals has been credited with enabling scientists to more closely infer what an animal wants. From a welfare perspective, this knowledge could improve how we care for animals under our management, as information about how animals prioritise rewarding items may guide how we allocate resources effectively. Our goal was to determine if behaviour in anticipation of different types of reward was differentially expressed. We investigated whether certain behaviours were characteristic of anticipation of both food and non-food rewards, and whether signals indicating rewards led to increased activity levels. Twelve laying hens experienced a Pavlovian conditioning paradigm using sound cues to signal the availability of two different food rewards (mealworms, normal food), one non-food reward (a container of mixed soil and sand substrate suitable for foraging and dust bathing (Dusty substrate)) and a sound-neutral event, which was signalled by a sound, but no reward was given. A muted-neutral treatment (no reward and no sound cue) controlled for any specific behaviour as a result of the sound cues.Behavioural responses and the number of transitions between behaviours were measured during a 15 s anticipatory period, before birds accessed rewards in an adjoining compartment by pushing through a door. These responses and latency to access the rewards were analysed using linear and generalised linear mixed models. Differences in pushing and pecking at the door (frequency: Dusty substrate 4.87a, Meal-worm 3.18b, Normal Food 2.23b, Sound Neutral 0.30c, Muted Neutral 0.03d, �2(4) = 228.99, p < 0.001),standing (not walking) (duration (s): Sound Neutral 9.92c, Muted Neutral 7.49bc, Normal Food 7.39bc, Mealworm 7.05b, Dusty substrate 3.06a, �2(4) = 36.28, p < 0.001), reflected the perceived value of the rewards, with birds appearing to be more motivated to access the Dusty substrate compared with the food rewards. Rewarded sound cues elicited increased transitions between behaviours, compared with neutral events (Dusty substrate 10.16a, Mealworm 10.13a, Normal Food 9.22ab, Sound Neutral 7.89bc, Muted Neutral 6.43c, �2(4) = 72.05, p < 0.001). The sound-neutral treatment induced increased head movements,previously associated with anticipation of rewards (duration (s): Sound Neutral 1.58b, Muted Neutral 0.58ab, Normal Food 0.48a, Mealworm 0.27a, Dusty substrate 0.00a, �2(4) = 25.56, p < 0.001). Latency to access rewards conveyed the relative value of rewards (Dusty substrate 7.30a, Mealworm 10.06ab,Normal Food 16.53b, �2(2) = 10.88, p = 0.004). Our experiment indicates that, under certain conditions,hens increase their activity levels (behavioural responses and transitions) in anticipation of rewards.Importantly, we demonstrate that this response is not food specific, but rather a general response to both food and non-food rewards. This outcome extends our knowledge of reward-related anticipatory behaviour, and of how hens rank rewards of contrasting incentive value, which may have implications for the methods and environments applied to improve the welfare of laying hens in managed systems

    Hens vary their vocal repertoire and structure when anticipating different types of reward

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    The vocalizations of nonhuman animals are considered potential indicators of motivational or internal state. In many species, different call types, and structural variation within call types, encode information about physical characteristics such as age or sex, or about variable traits such as motivation. Domestic chickens, Gallus gallus, have an elaborate vocal repertoire, enabling investigation into whether reward-related arousal is encoded within their call type and structure. Twelve hens were given a Pavlovian conditioning paradigm using sound cues to signal the availability of two food rewards (mealworms, normal food), one nonfood reward (a container of substrate suitable for dustbathing), and a sound-neutral event (sound cue, no reward). A muted-neutral treatment (no sound cue, no reward) provided a baseline for vocal behaviour. Sound cues preceded a 15 s anticipation period during which vocalizations were recorded. Hens produced a ‘Food call’ (previously defined in other studies) in anticipation of all rewards, including the nonfood reward. ‘Food calls’ and ‘Fast clucks’ were more prevalent in anticipation of rewards, and most prevalent following the cue signalling the dustbathing substrate, suggesting that this reward induced the most arousal in hens. The peak frequency of ‘Food calls’ made in anticipation of the dustbathing substrate was significantly lower than those made in anticipation of food rewards, potentially reflecting differences in arousal. Vocalizations that reliably indicate hens' motivational state could be used as measures of welfare in on-farm assessment situations. Our study is the first to reveal variation in the frequency-related parameters of the ‘Food call’ in different contexts, and to show the prevalence of different call types in reward and nonreward contexts, which may have implications for welfare assessments

    Genome-wide interaction study of a proxy for stress-sensitivity and its prediction of major depressive disorder

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    Individual response to stress is correlated with neuroticism and is an important predictor of both neuroticism and the onset of major depressive disorder (MDD). Identification of the genetics underpinning individual differences in response to negative events (stress-sensitivity) may improve our understanding of the molecular pathways involved, and its association with stress-related illnesses. We sought to generate a proxy for stress-sensitivity through modelling the interaction between SNP allele and MDD status on neuroticism score in order to identify genetic variants that contribute to the higher neuroticism seen in individuals with a lifetime diagnosis of depression compared to unaffected individuals. Meta-analysis of genome-wide interaction studies (GWIS) in UK Biobank (N = 23,092) and Generation Scotland: Scottish Family Health Study (N = 7,155) identified no genome-wide significance SNP interactions. However, gene-based tests identified a genome-wide significant gene, ZNF366, a negative regulator of glucocorticoid receptor function implicated in alcohol dependence (p = 1.48x10-7; Bonferroni-corrected significance threshold p < 2.79x10-6). Using summary statistics from the stress-sensitivity term of the GWIS, SNP heritability for stress-sensitivity was estimated at 5.0%. In models fitting polygenic risk scores of both MDD and neuroticism derived from independent GWAS, we show that polygenic risk scores derived from the UK Biobank stress-sensitivity GWIS significantly improved the prediction of MDD in Generation Scotland. This study may improve interpretation of larger genome-wide association studies of MDD and other stress-related illnesses, and the understanding of the etiological mechanisms underpinning stress-sensitivity

    Measuring progress and projecting attainment on the basis of past trends of the health-related Sustainable Development Goals in 188 countries: an analysis from the Global Burden of Disease Study 2016

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    The UN’s Sustainable Development Goals (SDGs) are grounded in the global ambition of “leaving no one behind”. Understanding today’s gains and gaps for the health-related SDGs is essential for decision makers as they aim to improve the health of populations. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016), we measured 37 of the 50 health-related SDG indicators over the period 1990–2016 for 188 countries, and then on the basis of these past trends, we projected indicators to 2030
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