244 research outputs found
The lactic acid bacterium, <em>Carnobacterium maltaromaticum</em> possess a diverse range of potential virulence genes some of which are related to similar genes in <em>Listeria monocytogenes</em>Â
Dynamics in Microbial Composition and Functionality over a Season in Two Contrasting Estuarine Systems
Coupling bacterioplankton populations and environment to community function in coastal temperate waters
Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely, Synechococcus (Cyanobacteria) was strongly correlated with protease activity. Furthermore, seasons exerted a profound effect on the substrate utilization capacity and composition of the communities. However, the pattern of substrate utilization capacity could not be directly linked to the community dynamics. The overall importance of dissolved organic matter (DOM) parameters in the LASSO models indicate that bacterioplankton respond to the present substrate landscape, with a particular importance of nitrogenous DOM. The analyses exemplifies that high taxonomic resolution can reveal links between individual populations and bulk bacterioplankton functions, and that for some taxa rRNA analyses are a necessary descriptor when attempting to correlate functions with communities. The reconciliation of patterns from two different systems indicates that the identified drivers of bacterioplankton community functions may be of broader relevance in coastal temperate waters
Asteroseismology of the Hyades red giant and planet host epsilon Tauri
Asteroseismic analysis of solar-like stars allows us to determine physical
parameters such as stellar mass, with a higher precision compared to most other
methods. Even in a well-studied cluster such as the Hyades, the masses of the
red giant stars are not well known, and previous mass estimates are based on
model calculations (isochrones). The four known red giants in the Hyades are
assumed to be clump (core-helium-burning) stars based on their positions in
colour-magnitude diagrams, however asteroseismology offers an opportunity to
test this assumption. Using asteroseismic techniques combined with other
methods, we aim to derive physical parameters and the evolutionary stage for
the planet hosting star epsilon Tau, which is one of the four red giants
located in the Hyades. We analysed time-series data from both ground and space
to perform the asteroseismic analysis. By combining high signal-to-noise (S/N)
radial-velocity data from the ground-based SONG network with continuous
space-based data from the revised Kepler mission K2, we derive and characterize
27 individual oscillation modes for epsilon Tau, along with global oscillation
parameters such as the large frequency separation and the ratio between the
amplitude of the oscillations measured in radial velocity and intensity as a
function of frequency. The latter has been measured previously for only two
stars, the Sun and Procyon. Combining the seismic analysis with interferometric
and spectroscopic measurements, we derive physical parameters for epsilon Tau,
and discuss its evolutionary status.Comment: 13 pages, 13 figures, 4 tables, accepted for publication in Astronomy
& Astrophysic
Tri-critical behavior in rupture induced by disorder
We discover a qualitatively new behavior for systems where the load transfer
has limiting stress amplification as in real fiber composites. We find that the
disorder is a relevant field leading to tri--criticality, separating a
first-order regime where rupture occurs without significant precursors from a
second-order regime where the macroscopic elastic coefficient exhibit power law
behavior. Our results are based on analytical analysis of fiber bundle models
and numerical simulations of a two-dimensional tensorial spring-block system in
which stick-slip motion and fracture compete.Comment: Revtex, 10 pages, 4 figures available upon reques
Simulating temporal evolution of pressure in two-phase flow in porous media
We have simulated the temporal evolution of pressure due to capillary and
viscous forces in two-phase drainage in porous media. We analyze our result in
light of macroscopic flow equations for two-phase flow. We also investigate the
effect of the trapped clusters on the pressure evolution and on the effective
permeability of the system. We find that the capillary forces play an important
role during the displacements for both fast and slow injection rates and both
when the invading fluid is more or less viscous than the defending fluid. The
simulations are based on a network simulator modeling two-phase drainage
displacements on a two-dimensional lattice of tubes.Comment: 12 pages, LaTeX, 14 figures, Postscrip
Combination of searches for WW, WZ, and ZZ resonances in pp collisions at root s=8 TeV with the ATLAS detector
Laypersons' understanding of relative risk reductions: Randomised cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Despite increasing recognition of the importance of involving patients in decisions on preventive healthcare interventions, little is known about how well patients understand and utilise information provided on the relative benefits from these interventions. The aim of this study was to explore whether lay people can discriminate between preventive interventions when effectiveness is presented in terms of relative risk reduction (RRR), and whether such discrimination is influenced by presentation of baseline risk.</p> <p>Methods</p> <p>The study was a randomised cross-sectional interview survey of a representative sample (n = 1,519) of lay people with mean age 59 (range 40â98) years in Denmark. In addition to demographic information, respondents were asked to consider a hypothetical drug treatment to prevent heart attack. Its effectiveness was randomly presented as RRR of 10, 20, 30, 40, 50 or 60 percent, and half of the respondents were presented with quantitative information on the baseline risk of heart attack. The respondents had also been asked whether they were diagnosed with hypercholesterolemia or had experienced a heart attack.</p> <p>Results</p> <p>In total, 873 (58%) of the respondents consented to the hypothetical treatment. While 49% accepted the treatment when RRR = 10%, the acceptance rate was 58â60% for RRR>10. There was no significant difference in acceptance rates across respondents irrespective of whether they had been presented with quantitative information on baseline risk or not.</p> <p>Conclusion</p> <p>In this study, lay people's decisions about therapy were only slightly influenced by the magnitude of the effect when it was presented in terms of RRR. The results may indicate that lay people have difficulties in discriminating between levels of effectiveness when they are presented in terms of RRR.</p
Hydrogenation properties of lithium and sodium hydride â closo-borate, [B10H10]2â and [B12H12]2â, composites
Š 2018 the Owner Societies. The hydrogen absorption properties of metal closo-borate/metal hydride composites, M2B10H10-8MH and M2B12H12-10MH, M = Li or Na, are studied under high hydrogen pressures to understand the formation mechanism of metal borohydrides. The hydrogen storage properties of the composites have been investigated by in situ synchrotron radiation powder X-ray diffraction at p(H2) = 400 bar and by ex situ hydrogen absorption measurements at p(H2) = 526 to 998 bar. The in situ experiments reveal the formation of crystalline intermediates before metal borohydrides (MBH4) are formed. On the contrary, the M2B12H12-10MH (M = Li and Na) systems show no formation of the metal borohydride at T = 400 °C and p(H2) = 537 to 970 bar.11B MAS NMR of the M2B10H10-8MH composites reveal that the molar ratio of LiBH4or NaBH4and the remaining B species is 1:0.63 and 1:0.21, respectively. Solution and solid-state11B NMR spectra reveal new intermediates with a B:H ratio close to 1:1. Our results indicate that the M2B10H10(M = Li, Na) salts display a higher reactivity towards hydrogen in the presence of metal hydrides compared to the corresponding [B12H12]2-composites, which represents an important step towards understanding the factors that determine the stability and reversibility of high hydrogen capacity metal borohydrides for hydrogen storage
Can postponement of an adverse outcome be used to present risk reductions to a lay audience? A population survey
BACKGROUND: For shared decision making doctors need to communicate the effectiveness of therapies such that patients can understand it and discriminate between small and large effects. Previous research indicates that patients have difficulties in understanding risk measures. This study aimed to test the hypothesis that lay people may be able to discriminate between therapies when their effectiveness is expressed in terms of postponement of an adverse disease event. METHODS: In 2004 a random sample of 1,367 non-institutionalized Danes aged 40+ was interviewed in person. The participants were asked for demographic information and asked to consider a hypothetical preventive drug treatment. The respondents were randomized to the magnitude of treatment effectiveness (heart attack postponement of 1 month, 6 months, 12 months, 2 years, 4 years and 8 years) and subsequently asked whether they would take such a therapy. They were also asked whether they had hypercholesterolemia or had experienced a heart attack. RESULTS: In total 58% of the respondents consented to the hypothetical treatment. The proportions accepting treatment were 39%, 52%, 56%, 64%, 67% and 73% when postponement was 1 month, 6 months, 12 months, 2 years, 4 years and 8 years respectively. Participants who thought that the effectiveness information was difficult to understand, were less likely to consent to therapy (p = 0.004). CONCLUSION: Lay people can discriminate between levels of treatment effectiveness when they are presented in terms of postponement of an adverse event. The results indicate that such postponement is a comprehensible measure of effectiveness
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