2,969 research outputs found
Mice null for brush border myosin I assemble brush borders and lack an overt phenotype
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Symptoms predicting psychosocial impairment in bulimia nervosa
Purpose
The current study aimed to determine which particular eating disorder (ED) symptoms and related features, such as BMI and psychological distress, uniquely predict impairment in bulimia nervosa (BN).
Methods
Two hundred and twenty-two adults with BN completed questionnaires assessing ED symptoms, general psychological distress, and psychosocial impairment. Regression analyses were used to determine predictors which account for variance in impairment.
Results
Four variables emerged as significant predictors of psychosocial impairment: concerns with eating; concerns with weight and shape; dietary restraint; and general psychological distress.
Conclusions
Findings support previous work highlighting the importance of weight and shape concerns in determining ED-related impairment. Other ED symptoms, notably dietary restraint and concerns with eating, were also significant predictors as was psychological distress. Results suggest that cognitive aspects of EDs, in addition to psychological distress, may be more important determinants of impairment than behavioural symptoms, such as binge eating or purging
Interstellar Dust Close to the Sun
The low density interstellar medium (ISM) close to the Sun and inside of the
heliosphere provides a unique laboratory for studying interstellar dust grains.
Grain characteristics in the nearby ISM are obtained from observations of
interstellar gas and dust inside of the heliosphere and the interstellar gas
towards nearby stars. Comparison between the gas composition and solar
abundances suggests that grains are dominated by olivines and possibly some
form of iron oxide. Measurements of the interstellar Ne/O ratio by the
Interstellar Boundary Explorer spacecraft indicate that a high fraction of
interstellar oxygen in the ISM must be depleted onto dust grains. Local
interstellar abundances are consistent with grain destruction in ~150 km/s
interstellar shocks, provided that the carbonaceous component is hydrogenated
amorphous carbon and carbon abundances are correct. Variations in relative
abundances of refractories in gas suggest variations in the history of grain
destruction in nearby ISM. The large observed grains, > 1 micron, may indicate
a nearby reservoir of denser ISM. Theoretical three-dimensional models of the
interaction between interstellar dust grains and the solar wind predict that
plumes of about 0.18 micron dust grains form around the heliosphere.Comment: 2011 AGOS Taiwan meeting; accepted for publication in Earth, Planets
and Spac
The Cosmology of Composite Inelastic Dark Matter
Composite dark matter is a natural setting for implementing inelastic dark
matter - the O(100 keV) mass splitting arises from spin-spin interactions of
constituent fermions. In models where the constituents are charged under an
axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark
matter scatters inelastically off Standard Model nuclei and can explain the
DAMA/LIBRA annual modulation signal. This article describes the early Universe
cosmology of a minimal implementation of a composite inelastic dark matter
model where the dark matter is a meson composed of a light and a heavy quark.
The synthesis of the constituent quarks into dark mesons and baryons results in
several qualitatively different configurations of the resulting dark matter
hadrons depending on the relative mass scales in the system.Comment: 31 pages, 4 figures; references added, typos correcte
Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations
North America's Eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programs often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response (rate of tongue-flick [RTF]). RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating predation and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is a potential low-cost alternative trap lure for the control of invasive corn snake populations
Fandom and Coercive Empowerment: The commissioned production of Chinese online literature
This article examines how the relationship between consumers and producers of cultural products is shaped by the proprietary nature of digital platforms. Drawing on 4 years of online observation and analysis, we examine the relationship between the producers of online Chinese fiction, amateur writers, and their consumers, that is, the fan communities of readers who respond to their work. Enabled by Chinese literary websites, readers act like sponsors who provide emotional and financial incentives for writers to produce online fictions by commenting, voting, and sending money. Readers become actively involved not just because of the content of the stories but because they form strong commitments to stories and their writers, and gain reciprocity and a sense of self-determination during the interactional process. We argue that although writers are freer from state control online, they are still beholden to the whims of their fans because of what we call the commissioned production of fictions. We contribute to fan community studies by analyzing how commercialized website settings structure the strategies available to participants, how these settings affect the content of the cultural products, and how the Chinese historical and cultural contexts impact the dynamics of the online community.postprin
<i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis
Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops
Controls on gut phosphatisation : the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah)
Despite being internal organs, digestive structures are frequently preserved in Cambrian Lagerstätten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alternative to appendage morphology for inferences on their biology. Here we describe the phosphatised digestive structures of three trilobite species from the Cambrian Weeks Formation Lagerstätte (Utah). Their exquisite, three-dimensional preservation reveals unique details on trilobite internal anatomy, such as the position of the mouth and the absence of a differentiated crop. In addition, the presence of paired pygidial organs of an unknown function is reported for the first time. This exceptional material enables exploration of the relationships between gut phosphatisation and the biology of organisms. Indeed, soft-tissue preservation is unusual in these fossils as it is restricted to the digestive structures, which indicates that the gut played a central role in its own phosphatisation. We hypothesize that the gut provided a microenvironment where special conditions could develop and harboured a source of phosphorus. The fact that gut phosphatization has almost exclusively been observed in arthropods could be explained by their uncommon ability to store ions (including phosphorous) in their digestive tissues. However, in some specimens from the Weeks Formation, the phosphatisation extends to the entire digestive system, suggesting that trilobites might have had some biological particularities not observed in modern arthropods. We speculate that one of them might have been an increased capacity for ion storage in the gut tissues, related to the moulting of their heavily-mineralised carapace
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