377 research outputs found

    Students’ Perceptions of Factors that Affect College Funding Decisions

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    This exploratory study examines the factors that college students perceive are important in helping them make good financial decisions about paying for a college education. The study categorizes and summarizes students\u27 self-reported responses to an openended survey question about recommendations for changes in financial aid counseling practices. The 335 student responses had a recurring theme of better information provided through individual counseling sessions

    Practitioners’ understanding of barriers to accessing specialist support by family carers of people with dementia in distress

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    Distressing symptoms in dementia are hard to manage for many family carers. This article explores practitioners' perceptions of the barriers to accessing skilled behaviour management support encountered by carers. A survey of cases referred to the English National Health Service (n = 5,360) was followed by in-depth group discussions and practitioner interviews. Data revealed that practitioners focused on care home residents or older people with mental health problems other than dementia, rather than community-dwelling people with dementia and families. Barriers to access included misperceptions about the nature of distressing behaviour affecting carers and structural limitations in the capacity of specialist services to respond to carers

    Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star

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    Most of our knowledge of extrasolar planets rests on precise radial-velocity measurements, either for direct detection or for confirmation of the planetary origin of photometric transit signals. This has limited our exploration of the parameter space of exoplanet hosts to solar- and later-type, sharp-lined stars. Here we extend the realm of stars with known planetary companions to include hot, fast-rotating stars. Planet-like transits have previously been reported in the lightcurve obtained by the SuperWASP survey of the A5 star HD15082 (WASP-33; V=8.3, v sin i = 86 km/sec). Here we report further photometry and time-series spectroscopy through three separate transits, which we use to confirm the existence of a gas giant planet with an orbital period of 1.22d in orbit around HD15082. From the photometry and the properties of the planet signal travelling through the spectral line profiles during the transit we directly derive the size of the planet, the inclination and obliquity of its orbital plane, and its retrograde orbital motion relative to the spin of the star. This kind of analysis opens the way to studying the formation of planets around a whole new class of young, early-type stars, hence under different physical conditions and generally in an earlier stage of formation than in sharp-lined late-type stars. The reflex orbital motion of the star caused by the transiting planet is small, yielding an upper mass limit of 4.1 Jupiter masses on the planet. We also find evidence of a third body of sub-stellar mass in the system, which may explain the unusual orbit of the transiting planet. In HD 15082, the stellar line profiles also show evidence of non-radial pulsations, clearly distinct from the planetary transit signal. This raises the intriguing possibility that tides raised by the close-in planet may excite or amplify the pulsations in such stars.Comment: 9 pages, 6 figures, accepted for publication in MNRA

    A cell cycle-coordinated Polymerase II transcription compartment encompasses gene expression before global genome activation

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    © 2019, The Author(s). Most metazoan embryos commence development with rapid, transcriptionally silent cell divisions, with genome activation delayed until the mid-blastula transition (MBT). However, a set of genes escapes global repression and gets activated before MBT. Here we describe the formation and the spatio-temporal dynamics of a pair of distinct transcription compartments, which encompasses the earliest gene expression in zebrafish. 4D imaging of pri-miR430 and zinc-finger-gene activities by a novel, native transcription imaging approach reveals transcriptional sharing of nuclear compartments, which are regulated by homologous chromosome organisation. These compartments carry the majority of nascent-RNAs and active Polymerase II, are chromatin-depleted and represent the main sites of detectable transcription before MBT. Transcription occurs during the S-phase of increasingly permissive cleavage cycles. It is proposed, that the transcription compartment is part of the regulatory architecture of embryonic nuclei and offers a transcriptionally competent environment to facilitate early escape from repression before global genome activation

    Effects of mountain gorilla foraging activities on the productivity of their food plant species

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    Mountain gorillas subsist principally on foliage from the dense herbaceous understorey that is found throughout most of their habitat in the Virunga Volcanoes region. Their foraging activities cause considerable structural damage to this vegetation. Those plant species that are quantitatively most important in the gorillas' diet respond to this damage by increasing primary productivity. At a sample of spots at which gorillas had fed, these species showed significantly higher growth rates over a 6-month interval than they did at nearby spots that had not been touched by the gorillas. Stem densities of herbaceous food species at feeding spots increased markedly both in comparison to their original values and to values for the same species at untouched spots. As a result, spots at which gorillas have fed are likely to become very attractive as future feeding spots. It is unlikely that gorillas ‘manage’ their habitat in any specific fashion, largely because they do not have exclusive use of their home ranges. Their activities appear to maintain habitat productivity over the short term, on a time scale relevant to patterns of area revisits by social groups, and may contribute to long term beneficial alterations of regularly used areas, however. Effects of the type reported here may have been an important aspect of the adaptation by gorillas to terrestrial folivory. RÉSUMEÉ Les gorilles de montagne s'alimentent principalement de feuillages dans le sous-bois herbacÉ dense prÉsent presque partout dans leur habitat de la rÉgion des volcans Virunga. Leurs activitÉs alimentaires causent des dommages structurels considÉrables À cette vÉgÉtation. Les plantes des espÈces qui sont quantitativement les plus importants dans le rÉgime du gorille rÉagissent À ces dÉgats en augmentant leur productivitÉ primaire. Aux postes Échantillons oÙ les gorilles se sont nourris, ces espÈces prÉsentent des taux de croissance significantivement supÉrieurs sur un intervalle de six mois, par rapport aux postes voisins qui n'ont pas ÉtÉ touchÉs par les gorilles. Les densitÉs de tiges des espÈces herbacÉes appÉtÉes aux postes de nourrissage augmentent nettement aussi bien en comparaison avec leurs valeurs antÉrieures qu'avec celles de ces měmes espÈces dans des stations non touchÉes. En consÉquence, les postes oÙ les gorilles se sont nourris ont plus de chance de devenir des futurs postes de nourrissage trÈs attractifs. Il est peu probable que les gorilles ‘gÈrent’ leur habitat d'une quelconque faÇon, surtout parce qu'ils n'ont pas l'utilisation exclusive de leur domaine vital. Leurs activitÉs semblent maintenir À court terme la productivitÉ de leur habitat, sur une Échelle de temps comprenant les visites successives de groupes sociaux, et peuvent contribuer À long terme À des altÉrations bÉnÉfiques pour ces zones rÉguliÉrement frÉquentÉes. Des effets du type rapportÉ ici peuvent avoir ÉtÉ un ÉlÉment important de l'adaptation des gorilles À la folivorie terrestre.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75171/1/j.1365-2028.1987.tb01102.x.pd

    Observation of the full 12-hour-long transit of the exoplanet HD80606b. Warm-Spitzer photometry and SOPHIE spectroscopy

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    We present new observations of a transit of the 111-day-period exoplanet HD80606b. Using the Spitzer Space Telescope and its IRAC camera on the post-cryogenic mission, we performed a 19-hour-long photometric observation of HD80606 that covers the full transit of 13-14 January 2010. We complement this photometric data by new spectroscopic observations that we simultaneously performed with SOPHIE at Haute-Provence Observatory. This provides radial velocity measurements of the first half of the transit that was previously uncovered with spectroscopy. This new data set allows the parameters of this singular planetary system to be significantly refined. We obtained a planet-to-star radius ratio R_p/R_* = 0.1001 +/- 0.0006 that is slightly lower than the one measured from previous ground observations. We detected a feature in the Spitzer light curve that could be due to a stellar spot. We also found a transit timing about 20 minutes earlier than the ephemeris prediction; this could be caused by actual TTVs due to an additional body in the system or by underestimated systematic uncertainties. The sky-projected angle between the spin-axis of HD80606 and the normal to the planetary orbital plane is found to be lambda = 42 +/- 8 degrees thanks to the fit of the Rossiter-McLaughlin anomaly. This allows scenarios with aligned spin-orbit to be definitively rejected. Over the twenty planetary systems with measured spin-orbit angles, a few of them are misaligned; this is probably the signature of two different evolution scenarios for misaligned and aligned systems, depending if they experienced or not gravitational interaction with a third body. As in the case of HD80606b, most of the planetary systems including a massive planet are tilted; this could be the signature of a separate evolution scenario for massive planets in comparison with Jupiter-mass planets.Comment: 14 pages, 9 figures, 2 tables, accepted for publication in A&

    The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b

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    We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 +/- 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spin-orbit angle is between 32-87 deg with 68.3% confidence and between 14-142 deg with 99.73% confidence. Thus the orbit of this planet is not only highly eccentric (e=0.93), but is also tilted away from the equatorial plane of its parent star. A large tilt had been predicted, based on the idea that the planet's eccentric orbit was caused by the Kozai mechanism. Independently of the theory, it is noteworthy that all 3 exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting that those systems migrate differently than lower-mass planets on circular orbits.Comment: ApJ, in press [13 pg

    Endowment Effects in Gorillas (Gorilla gorilla)

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    Reports of endowment effects in nonhuman primates have received considerable attention in the comparative literature in recent years. However, little is known about the mechanisms underlying these effects. Continuing to explore endowment effects across different species of primate may reveal subtle differences in behavior that can help formulate specific hypotheses about the relevant mechanisms and the social and ecological factors that have shaped them. In this study, we use a paradigm that has previously been used to test chimpanzees (Pan troglodytes) and orangutans (Pongo spp.) to explore whether western lowland gorillas (Gorilla gorilla) exhibit comparable endowment effects. We find that gorillas exhibit endowment effects when in possession of food, but not nonfood, items, and that they show a statistically stronger effect than chimpanzees but not orangutans. These findings are consistent with the hypothesis that mechanisms for endowment effects in primates may be related to inhibitory control or risk aversion

    Sexual dimorphism in postcranial skeletal shape suggests male‐biased specialization for physical competition in anthropoid primates

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    Sexual dimorphism often arises as a response to selection on traits that improve a male's ability to physically compete for access to mates. In primates, sexual dimorphism in body mass and canine size is more common in species with intense male–male competition. However, in addition to these traits, other musculoskeletal adaptations may improve male fighting performance. Postcranial traits that increase strength, agility, and maneuverability may also be under selection. To test the hypothesis that males, as compared to females, are more specialized for physical competition in their postcranial anatomy, we compared sex‐specific skeletal shape using a set of functional indices predicted to improve fighting performance. Across species, we found significant sexual dimorphism in a subset of these indices, indicating the presence of skeletal shape sexual dimorphism in our sample of anthropoid primates. Mean skeletal shape sexual dimorphism was positively correlated with sexual dimorphism in body size, an indicator of the intensity of male–male competition, even when controlling for both body mass and phylogenetic relatedness. These results suggest that selection on male fighting ability has played a role in the evolution of postcranial sexual dimorphism in primates
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