1,861 research outputs found

    The release of a captive-raised female African Elephant <em>(Loxodonta africana</em>) in the Okavango Delta, Botswana

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    Wild female elephants live in close-knit matrilineal groups and housing captive elephants in artificial social groupings can cause significant welfare issues for individuals not accepted by other group members. We document the release of a captive-raised female elephant used in the safari industry because of welfare and management problems. She was fitted with a satellite collar, and spatial and behavioural data were collected over a 17-month period to quantify her interactions with the wild population. She was then monitored infrequently for a further five-and-a-half years. We observed few signs of aggression towards her from the wild elephants with which she socialized. She used an area of comparable size to wild female elephants, and this continued to increase as she explored new areas. Although she did not fully integrate into a wild herd, she had three calves of her own, and formed a social unit with another female and her calf that were later released from the same captive herd. We recommend that release to the wild be considered as a management option for other captive female elephants

    Chirality in Liquid Crystals: from Microscopic Origins to Macroscopic Structure

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    Molecular chirality leads to a wonderful variety of equilibrium structures, from the simple cholesteric phase to the twist-grain-boundary phases, and it is responsible for interesting and technologically important materials like ferroelectric liquid crystals. This paper will review some recent advances in our understanding of the connection between the chiral geometry of individual molecules and the important phenomenological parameters that determine macroscopic chiral structure. It will then consider chiral structure in columnar systems and propose a new equilibrium phase consisting of a regular lattice of twisted ropes.Comment: 20 pages with 6 epsf figure

    Usefulness of heart measures in flight simulation

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    The results of three studies performed at the NASA Langley Research Center are presented to indicate the areas in which heart measures are useful for detecting differences in the workload state of subjects. Tasks that involve the arousal of the sympathetic nervous system, such as landing approaches, were excellent candidates for the use of average heart-rate and/or the increase in heart-rate during a task. The latter of these two measures was the better parameter because it removed the effects of diurnal variations in heart-rate and some of the intersubject variability. Tasks which differ in the amount of mental resources required are excellent candidates for heart-rate variability measures. Heart-rate variability measures based upon power spectral density techniques were responsive to the changing task demands of landing approach tasks, approach guidance options, and 2 versus 20 second interstimulus-intervals of a monitoring task. Heart-rate variability measures were especially sensitive to time-on-task when the task was characterized by minimal novelty, complexity, and uncertainty (i.e., heart-rate variability increases as a function of the subjects boredom)

    Ratio of absorption cross section for Dirac fermion to that for scalar in the higher-dimensional black hole background

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    The ratio of the low-energy absorption cross section for Dirac fermion to that for minimally coupled scalar is computed when the spacetimes are various types of the higher-dimensional Reissner-Nordstr\"{o}m black holes. It is found that the low-energy absorption cross sections for the Dirac fermion always goes to zero in the extremal limit regardless of the detailed geometry of the spacetime. The physical importance of our results is discussed in the context of the brane-world scenarios and string theories.Comment: 12 pages, no figure, V2: several references added, version to appear in PL

    A GPU based Transient Dedisersion Search Engine for CRAFT

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    The Commensal Realtime ASKAP Fast Transient Survey (CRAFT[5]) will search the ASKAP data stream for fast (< 5sec) transient events, associated with the most extreme conditions in the Universe. The CRAFT search will run in parallel with all normal observing on ASKAP, giving a tremendous advance in the transient parameter space which can be searched. ASKAP offers high sensitivity, high resolution, and continous observations of a significant portion of the sky. However, to search across the wide field of view and at the data rates which are being provided by ASKAP is extremely challenging. Nevertheless, as reported here, we are on track to achieve the goals as laid out in the Survey Science Proposal. Using GPUs as a simple highly parallel compute-engine we can monitor the full field of view with a 5(sigma) sensitivity of ~Jy for a millisecond event covering the astronomically significant range of DMs. After that trigger detection we can download the beamformer data-buffer and image the sky at full sensitivity and spatial resolution with an arbitary frequency and time resolution

    Civic Engagement and People with Disabilities: The Role of Advocacy and Technology

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    Disability legislation acknowledges the right of people with disabilities to participate in political and public life on an equal basis with others, but there continue to be significant barriers in accessing all aspects of the policymaking process. Advocacy and technology are two core strategies used by the disability community to advance the rights of people with disabilities. Further understanding of how these strategies and tools empower people with disabilities to connect with government is needed. This research seeks to develop and enhance civic knowledge and practices of people with disabilities by conducting civic engagement training and evaluation and examining the role of four disability advocacy organizations. Using qualitative and quantitative data, the research explores the inclusion and participation of people with disabilities in civic society, with a focus on advocacy and technology

    An Analysis of Environmental, Social, and Corporate Governance (ESG) Ratings of Lean Versus Non-Lean Companies

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    Lean manufacturing is a business philosophy concerned with continually eliminating waste from business processes while producing quality products with greater efficiency. In addition to profits, organizations worldwide are beginning to focus on environmental, social, and corporate-governance (ESG) factors because of the changing global environment. The Environmental Protection Agency has specifically stated that many organizations have found that implementing lean manufacturing concepts and tools results in improvements in environmental performance. This study uses a matched-pairs design, matching lean companies with non-lean companies, and assesses whether lean companies experienced better Sustainalytics ESG risk ratings than non-lean companies. Results show that lean companies achieved more favorable ratings in environmental, social, and corporate-governance factors than did non-lean companies

    Emissivities for the various Graviton Modes in the Background of the Higher-Dimensional Black Hole

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    The Hawking emissivities for the scalar-, vector-, and tensor-mode bulk gravitons are computed in the full range of the graviton's energy by adopting the analytic continuation numerically when the spacetime background is (4+n)(4+n)-dimensional non-rotating black hole. The total emissivity for the gravitons is only 5.16% of that for the spin-0 field when there is no extra dimension. However, this ratio factor increases rapidly when the extra dimensions exist. For example, this factor becomes 147.7%, 595.2% and 3496% when the number of extra dimensions is 1, 2 and 6, respectively. This fact indicates that the Hawking radiation for the graviton modes becomes more and more significant and dominant with increasing the number of extra dimensions.Comment: 14 pages, 5 eps figures, V2: the incorrect multiplicities are corrected. PLB versio

    Garnet–monazite rare earth element relationships in sub-solidus metapelites: a case study from Bhutan

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    A key aim of modern metamorphic geochronology is to constrain precise and accurate rates and timescales of tectonic processes. One promising approach in amphibolite and granulite-facies rocks links the geochronological information recorded in zoned accessory phases such as monazite to the pressure–temperature information recorded in zoned major rock-forming minerals such as garnet. Both phases incorporate rare earth elements (REE) as they crystallize and their equilibrium partitioning behaviour potentially provides a useful way of linking time to temperature. We report REE data from sub-solidus amphibolite-facies metapelites from Bhutan, where overlapping ages, inclusion relationships and Gd/Lu ratios suggest that garnet and monazite co-crystallized. The garnet–monazite REE relationships in these samples show a steeper pattern across the heavy (H)REE than previously reported. The difference between our dataset and the previously reported data may be due to a temperature-dependence on the partition coefficients, disequilibrium in either dataset, differences in monazite chemistry or the presence or absence of a third phase that competed for the available REE during growth. We urge caution against using empirically-derived partition coefficients from natural samples as evidence for, or against, equilibrium of REE-bearing phases until monazite–garnet partitioning behaviour is better constrained
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