1,550 research outputs found
Study of particles collected by the 1965 Luster rocket
Heat annealing tests of Luster rocket collected micrometeorites to determine whether radiation damage can distinguish extraterrestrial from terrestrial particle
Large-Scale Release of Campylobacter Draft Genomes: Resources for Food Safety and Public Health from the 100K Pathogen Genome Project.
Campylobacter is a food-associated bacterium and a leading cause of foodborne illness worldwide, being associated with poultry in the food supply. This is the initial public release of 202 Campylobacter genome sequences as part of the 100K Pathogen Genome Project. These isolates represent global genomic diversity in the Campylobacter genus
Surface Instability of Icicles
Quantitatively-unexplained stationary waves or ridges often encircle icicles.
Such waves form when roughly 0.1 mm-thick layers of water flow down the icicle.
These waves typically have a wavelength of 1cm approximately independent of
external temperature, icicle thickness, and the volumetric rate of water flow.
In this paper we show that these waves can not be obtained by naive
Mullins-Sekerka instability, but are caused by a quite new surface instability
related to the thermal diffusion and hydrodynamic effect of thin water flow.Comment: 11 pages, 5 figures, Late
Fur seal microbiota are shaped by the social and physical environment, show motherâoffspring similarities and are associated with host genetic quality
Despite an increasing appreciation of the importance of hostâmicrobe interactions in ecological and evolutionary processes, the factors shaping microbial communities in wild populations remain poorly understood. We therefore exploited a natural experiment provided by two adjacent Antarctic fur seal (Arctocephalus gazella) colonies of high and low social density and combined 16S rRNA metabarcoding with microsatellite profiling of motherâoffspring pairs to investigate environmental and genetic influences on skin microbial communities. Sealâassociated bacterial communities differed profoundly between the two colonies, despite the host populations themselves being genetically undifferentiated. Consistent with the hypothesis that social stress depresses bacterial diversity, we found that microbial alpha diversity was significantly lower in the highâdensity colony. Seals from one of the colonies that contained a stream also carried a subset of freshwaterâassociated bacteria, indicative of an influence of the physical environment. Furthermore, mothers and their offspring shared similar microbial communities, in support of the notion that microbes may facilitate motherâoffspring recognition. Finally, a significant negative association was found between bacterial diversity and heterozygosity, a measure of host genetic quality. Our study thus uncovers a complex interplay between environmental and host genetic effects, while also providing empirical support for the leash model of host control, which posits that bacterial communities are driven not only by bottomâup species interactions, but also by topâdown host regulation. Taken together, our findings have broad implications for understanding hostâmicrobe interactions as well as prokaryotic diversity in general
Measuring activities in tobacco control across the EU. The MAToC
BACKGROUND: Objectives of this study are (a) to develop a comprehensive and economic tool to estimate tobacco control (TC) activities in single EU member states, (b) to compare TC activities between member states of the EU. This article provides the questionnaire and gives a benchmark of EU member states according to their perceived TC activities. Methods: An international workshop was specifically initiated to develop the questionnaire "Measuring Activities in Tobacco Control (MATOC)". TC experts from 8 European countries participated and chose 40 items to cover 11 general topics of TC. At the World Conference of Tobacco or Health in Helsinki 2003 participants were asked to fill out the questionnaire. N = 142 participants from EU-member states returned questionnaires. RESULTS: Subjects from the tobacco field in Finland gave the highest TC values to their country, followed by Sweden, Ireland, the UK and the Netherlands. The least active countries in TC were Greece and Germany, behind Austria, Spain, Belgium and Portugal. Italy, France and Denmark constituted the middle field. CONCLUSION: The MATOC provides a profile of TC across European countries and delivers results that are plausible and fit into the existing findings. The data presented here fulfils the purpose to illustrate what is possible with the MATOC and underlines the value of such an approach in delivering information for policy makers and TC advocates how TC is perceived in each country. Yet, further validity testing is necessary, the number of experts per country differs and is partly rather small. Further research with the MATOC should encounter these limitations. The procedure though could serve as model of practice for alcohol and legal drug policy as well
Punctuated equilibria and 1/f noise in a biological coevolution model with individual-based dynamics
We present a study by linear stability analysis and large-scale Monte Carlo
simulations of a simple model of biological coevolution. Selection is provided
through a reproduction probability that contains quenched, random interspecies
interactions, while genetic variation is provided through a low mutation rate.
Both selection and mutation act on individual organisms. Consistent with some
current theories of macroevolutionary dynamics, the model displays
intermittent, statistically self-similar behavior with punctuated equilibria.
The probability density for the lifetimes of ecological communities is well
approximated by a power law with exponent near -2, and the corresponding power
spectral densities show 1/f noise (flicker noise) over several decades. The
long-lived communities (quasi-steady states) consist of a relatively small
number of mutualistically interacting species, and they are surrounded by a
``protection zone'' of closely related genotypes that have a very low
probability of invading the resident community. The extent of the protection
zone affects the stability of the community in a way analogous to the height of
the free-energy barrier surrounding a metastable state in a physical system.
Measures of biological diversity are on average stationary with no discernible
trends, even over our very long simulation runs of approximately 3.4x10^7
generations.Comment: 20 pages RevTex. Minor revisions consistent with published versio
En compagnie de la guerre
The dissolution of AcĂ©phale marked the beginning of the war as well as Batailleâs commitment to âthe inner experienceâ. Through this surrender to ecstasy, Bataille never ceased â even with chance encounters â to agitate morals and heighten the value of sin. Of the relationship between community and sovereignty, whatâs left to examine? That is the question this article seeks to answer.Die Auflösung des Geheimbundes LâAcĂ©phale fĂ€llt mit dem Anfang des Krieges zusammen, und mit dem Beginn eines neuen Verfahrens fĂŒr Georges Bataille: die âinnere Erfahrungâ
Abnormal expression of p27kip1 protein in levator ani muscle of aging women with pelvic floor disorders â a relationship to the cellular differentiation and degeneration
BACKGROUND: Pelvic floor disorders affect almost 50% of aging women. An important role in the pelvic floor support belongs to the levator ani muscle. The p27/kip1 (p27) protein, multifunctional cyclin-dependent kinase inhibitor, shows changing expression in differentiating skeletal muscle cells during development, and relatively high levels of p27 RNA were detected in the normal human skeletal muscles. METHODS: Biopsy samples of levator ani muscle were obtained from 22 symptomatic patients with stress urinary incontinence, pelvic organ prolapse, and overlaps (age range 38â74), and nine asymptomatic women (age 31â49). Cryostat sections were investigated for p27 protein expression and type I (slow twitch) and type II (fast twitch) fibers. RESULTS: All fibers exhibited strong plasma membrane (and nuclear) p27 protein expression. cytoplasmic p27 expression was virtually absent in asymptomatic women. In perimenopausal symptomatic patients (ages 38â55), muscle fibers showed hypertrophy and moderate cytoplasmic p27 staining accompanied by diminution of type II fibers. Older symptomatic patients (ages 57â74) showed cytoplasmic p27 overexpression accompanied by shrinking, cytoplasmic vacuolization and fragmentation of muscle cells. The plasma membrane and cytoplasmic p27 expression was not unique to the muscle cells. Under certain circumstances, it was also detected in other cell types (epithelium of ectocervix and luteal cells). CONCLUSIONS: This is the first report on the unusual (plasma membrane and cytoplasmic) expression of p27 protein in normal and abnormal human striated muscle cells in vivo. Our data indicate that pelvic floor disorders are in perimenopausal patients associated with an appearance of moderate cytoplasmic p27 expression, accompanying hypertrophy and transition of type II into type I fibers. The patients in advanced postmenopause show shrinking and fragmentation of muscle fibers associated with strong cytoplasmic p27 expression
Credibility and adjustment: gold standards versus currency boards
It is often maintained that currency boards (CBs) and gold standards (GSs) are alike in that they are stringent monetary rules, the two basic features of which are high credibility of monetary authorities and the existence of automatic adjustment (non discretionary) mechanism. This article includes a comparative analysis of these two types of regimes both from the perspective of the sources and mechanisms of generating confidence and credibility, and the elements of operation of the automatic adjustment mechanism. Confidence under the GS is endogenously driven, whereas it is exogenously determined under the CB. CB is a much more asymmetric regime than GS (the adjustment is much to the detriment of peripheral countries) although asymmetry is a typical feature of any monetary regime. The lack of credibility is typical for peripheral countries and cannot be overcome completely even by âhardâ monetary regimes.http://deepblue.lib.umich.edu/bitstream/2027.42/40078/3/wp692.pd
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