432 research outputs found
Introducing the Digital Scholarship Lab
Milner Library recently opened a Digital Scholarship Lab and invites the community to consider how it might inform their teaching and research. Developed with input from two interdisciplinary working groups, the lab provides a space, programming, and specialized software and equipment for those interested in applying digital methods to their research and learning. The speakers will highlight some of the capabilities of the lab and invite your questions about integrating the space into your instruction and research. The session will bring together scholars with an interest in learning more about and engaging in digital scholarship, extending the community of practice on our campus
NFIRAOS: TMT's facility adaptive optics system
NFIRAOS, the TMT Observatory's initial facility AO system is a multi-conjugate AO system feeding science light from 0.8 to 2.5 microns wavelength to several near-IR client instruments. NFIRAOS has two deformable mirrors optically conjugated to 0 and 11.2 km, and will correct atmospheric turbulence with 50 per cent sky coverage at the galactic pole. An important requirement is to have very low background: the plan is to cool the optics; and one DM is on a tip/tilt stage to reduce surface count. NFIRAOS' real time control uses multiple sodium laser wavefront sensors and up to three IR natural guide star tip/tilt and/or tip/tilt/focus sensors located within each client instrument. Extremely large telescopes are sensitive to errors due to the variability of the sodium layer. To reduce this sensitivity, NFIRAOS uses innovative algorithms coupled with Truth wavefront sensors to monitor a natural star at low bandwidth. It also includes an IR acquisition camera, and a high speed NGS WFS for operation without lasers. For calibration, NFIRAOS includes simulators of both natural stars at infinity and laser guide stars at varying range distance. Because astrometry is an important science programme for NFIRAOS, there is a precision pinhole mask deployable at the input focal plane. This mask is illuminated by a science wavelength and flat-field calibrator that shines light into NFIRAOS' entrance window. We report on recent effort especially including trade studies to reduce field distortion in the science path and to reduce cost and complexity
Main-Belt Comet P/2012 T1 (PANSTARRS)
We present initial results from observations and numerical analyses aimed at
characterizing main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring
observations were made between October 2012 and February 2013 using the
University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay
Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell
Observatory, and the Southern Astrophysical Research (SOAR) telescope. The
object's intrinsic brightness approximately doubles from the time of its
discovery in early October until mid-November and then decreases by ~60%
between late December and early February, similar to photometric behavior
exhibited by several other main-belt comets and unlike that exhibited by
disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic
searches for CN emission as well as absorption at 0.7 microns that could
indicate the presence of hydrated minerals, finding an upper limit CN
production rate of QCN<1.5x10^23 mol/s, from which we infer a water production
rate of QH2O<5x10^25 mol/s, and no evidence of the presence of hydrated
minerals. Numerical simulations indicate that P/2012 T1 is largely dynamically
stable for >100 Myr and is unlikely to be a recently implanted interloper from
the outer solar system, while a search for potential asteroid family
associations reveal that it is dynamically linked to the ~155 Myr-old Lixiaohua
asteroid family.Comment: 15 pages, 4 figures, accepted for publication in ApJ Letter
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The changing influence of societal culture on job satisfaction across Europe
This paper contributes to the growing multidisciplinary body of literature on subjective well-being by investigating the longitudinal stability and impact of societal cultural values (SCVs) – as opposed to the more common organizational values – on job satisfaction. It is assumed that SCVs evolve slowly; hence, their impact on job satisfaction is likely to remain stable over time. False adherence to this assumption could cause misalignment between organizational policies/practices and expectations formed by societal culture, decreasing job satisfaction and adversely affecting productivity, competiveness and prosperity. Four waves of the European Values Study are used to examine whether SCVs have evolved and their impacts on job satisfaction over a relatively short time: 1981–2008. SCVs are parameterized through reference to traditional vs secular-rational, and survival vs self-expression value continuums. Results indicate that the strength of many SCVs has declined, the impacts of traditional societal values on job satisfaction have remained fairly constant, and the impacts of survival societal values on job satisfaction have declined substantially over this sample period. These reductions in SCVs amplify the importance of accounting for such changes when designing new or adjusting existing policies/practices to enhance job satisfaction and stimulate improvements in productivity, competitiveness and prosperity
Evidence of opposing fitness effects of parental heterozygosity and relatedness in a critically endangered marine turtle?
How individual genetic variability relates to fitness is important in understanding evolution and the processes affecting populations of conservation concern. Heterozygosity–fitness correlations (HFCs) have been widely used to study this link in wild populations, where key parameters that affect both variability and fitness, such as inbreeding, can be difficult to measure. We used estimates of parental heterozygosity and genetic similarity (‘relatedness’) derived from 32 microsatellite markers to explore the relationship between genetic variability and fitness in a population of the critically endangered hawksbill turtle, Eretmochelys imbricata. We found no effect of maternal MLH (multilocus heterozygosity) on clutch size or egg success rate, and no single-locus effects. However, we found effects of paternal MLH and parental relatedness on egg success rate that interacted in a way that may result in both positive and negative effects of genetic variability. Multicollinearity in these tests was within safe limits, and null simulations suggested that the effect was not an artefact of using paternal genotypes reconstructed from large samples of offspring. Our results could imply a tension between inbreeding and outbreeding depression in this system, which is biologically feasible in turtles: female-biased natal philopatry may elevate inbreeding risk and local adaptation, and both processes may be disrupted by male-biased dispersal. Although this conclusion should be treated with caution due to a lack of significant identity disequilibrium, our study shows the importance of considering both positive and negative effects when assessing how variation in genetic variability affects fitness in wild systems
Fifty-year study of microplastics ingested by brachyuran and fish larvae in the central English North Sea
\ua9 2023 The Authors. Microplastics (MPs) are ubiquitous pollutants in marine environments. Among the many detrimental consequences of microplastic pollution, its consumption by marine biota is of particular relevance for human health, due to exposure through the food web. Long-term time-series biotic samples are overlooked sources of information for microplastics research. These collections are extremely valuable for the detection and monitoring of changes in marine environments. However, there are very few long-term studies (>10 years) of the uptake of microplastics by biota. Here, we used Dove Time Series planktonic samples (from 1971 to 2020) to assess the presence and prevalence of microplastics in the English North Sea coast over time. Fish and brachyuran larvae were selected due to their commercial importance and consequent implications for human health. A custom enzymatic digestion method was used to extract microplastics for FTIR-ATR polymer identification. An increasing cumulative trend in MP ingestion was identified. Cellophane and polyethylene terephthalate were the polymer types found most frequently in both taxa. Although a total higher microplastics uptake was observed in fish, consumption was not significantly different between taxa over time. Equally, results were not clearly related to microplastics shape or polymer type. This work did not find significant long-term evidence on the increasing uptake of microplastic particles by zooplankton over time. However, the results of this report identified additives, plasticisers, and other more complex and hazardous compounds that should not be released to the environment (e.g., bis-(2-hydroxyethyl) dimerate, propylene glycol ricinoleate) inside marine biota. The study detailed herein provides a case study for the use of long-term time-series in providing accurate assessments of microplastic pollution in marine biota
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