7,204 research outputs found
Idle central venous catheter-days pose infection risk for patients after discharge from intensive care
This prospective observational study measured idle central venous catheter (CVC)-days (no medical indication), and ward clinicians\u27 adherence to evidence-based practices for preventing short-term central line-associated bloodstream infections (CLABSIs). In 340 patients discharged from ICU over a 1-year period, 208 of 794 CVC-days (26.2%) were idle. Interventions to prevent CLABSIs were poorly implemented. Ward clinicians need education regarding risk management strategies to prevent CLABSIs, and clear accountability processes for prompt catheter removal are recommended
Effects on transgenic thuringiensis on European corn borer natural enemies and non-target Lepidopteran pests
Field corn, genetically engineered to produce a protein derived from Bacillus thuringiensis, was evaluated for its effects on larvae of black cutworm, stalk borer, armyworm, and corn earworm. No Btcorn effects were observed on larval survival, pupal weight, or days to adult emergence for black cutworm or stalk borer. Armyworms reared on Bt leaf extract were lighter-weight, delayed in development, and showed diminished survival rates. Corn earworm showed reduced survival and delays in development. In field tests of Bt and non-Bt corn, there were no differences between the two varieties in damage from black cutworm. Stalk borer caused less leaf damage to Bt corn. Armyworm and corn earworm did less harm to Bt corn leaves than to non-Bt corn leaves, but corn earworm survived to cause some damage to Bt corn ears
Efficient Identification of HIV Serodiscordant Couples by Existing HIV Testing Programs in South Brazil.
ObjectiveTo examine the feasibility of identifying HIV negative at risk individuals in HIV serodiscordant couples, during voluntary HIV testing in South Brazil.MethodsWe surveyed HIV testers at 4 public testing sites in Rio Grande do Sul. We obtained information on risk behaviors and sexual partnerships. HIV testing and testing for recent infection were performed; HIV prevalence and risk behaviors were assessed among subjects who reported having a steady partner who was HIV positive (serodiscordant group) and compared with the general testing population.ResultsAmong 3100 patients, 490 (15.8%) reported being in a steady relationship with an HIV positive partner. New HIV infections were diagnosed in 23% of the serodiscordant group (vs. 13% in the general population, p = 0.01); among newly positive subjects, recent HIV infections were more frequent (23/86, 26.7%) among testers with positive partners than among the general testing group (52/334; 15.6%; p = 0.016). Less than half of the serodiscordant testers reported having used a condom during the last sexual intercourse with their HIV-positive partner. Participants with inconsistent condom use with steady partner were four times more likely to test positive for HIV compared to those who reported always using condoms with the steady partner (OR: 4.2; 95% CI: 2.3 to 7.5).ConclusionIt is highly feasible to identify large numbers of HIV susceptible individuals who are in HIV serodiscordant relationships in South Brazil testing sites. Condom use within HIV serodiscordant couples is low in this setting, suggesting urgent need for biomedical prevention strategies to reduce HIV transmission
Isotopic Production Cross Sections in Proton-Nucleus Collisions at 200 MeV
Intermediate mass fragments (IMF) from the interaction of Al,
Co and Au with 200 MeV protons were measured in an angular range
from 20 degree to 120 degree in the laboratory system. The fragments, ranging
from isotopes of helium up to isotopes of carbon, were isotopically resolved.
Double differential cross sections, energy differential cross sections and
total cross sections were extracted.Comment: accepted by Phys. Rev.
An anisotropic distribution of spin vectors in asteroid families
Current amount of ~500 asteroid models derived from the disk-integrated
photometry by the lightcurve inversion method allows us to study not only the
spin-vector properties of the whole population of MBAs, but also of several
individual collisional families. We create a data set of 152 asteroids that
were identified by the HCM method as members of ten collisional families, among
them are 31 newly derived unique models and 24 new models with well-constrained
pole-ecliptic latitudes of the spin axes. The remaining models are adopted from
the DAMIT database or the literature. We revise the preliminary family
membership identification by the HCM method according to several additional
criteria - taxonomic type, color, albedo, maximum Yarkovsky semi-major axis
drift and the consistency with the size-frequency distribution of each family,
and consequently we remove interlopers. We then present the spin-vector
distributions for eight asteroidal families. We use a combined orbital- and
spin-evolution model to explain the observed spin-vector properties of objects
among collisional families. In general, we observe for studied families similar
trends in the (a_p, \beta) space: (i) larger asteroids are situated in the
proximity of the center of the family; (ii) asteroids with \beta>0{\deg} are
usually found to the right from the family center; (iii) on the other hand,
asteroids with \beta<0{\deg} to the left from the center; (iv) majority of
asteroids have large pole-ecliptic latitudes (|\beta|\gtrsim 30{\deg}); and
finally (v) some families have a statistically significant excess of asteroids
with \beta>0{\deg} or \beta<0{\deg}. Our numerical simulation of the long-term
evolution of a collisional family is capable of reproducing well the observed
spin-vector properties. Using this simulation, we also independently constrain
the age of families Flora (1.0\pm0.5 Gyr) and Koronis (2.5-4 Gyr).Comment: Accepted for publication in A&A (September 16, 2013
Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers
As the Tevatron luminosity increases sophisticated selections are required to
be efficient in selecting rare events among a very huge background. To cope
with this problem, CDF has pushed the offline calorimeter algorithm
reconstruction resolution up to Level 2 and, when possible, even up to Level 1,
increasing efficiency and, at the same time, keeping under control the rates.
The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is
based on a simple algorithm that was used in Run I. This system has worked well
for Run II at low luminosity. As the Tevatron instantaneous luminosity
increases, the limitation due to this simple algorithm starts to become clear:
some of the most important jet and MET (Missing ET) related triggers have large
growth terms in cross section at higher luminosity. In this paper, we present
an upgrade of the Level 2 Calorimeter system which makes the calorimeter
trigger tower information available directly to a CPU allowing more
sophisticated algorithms to be implemented in software. Both Level 2 jets and
MET can be made nearly equivalent to offline quality, thus significantly
improving the performance and flexibility of the jet and MET related triggers.
However in order to fully take advantage of the new L2 triggering capabilities
having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET
resolution is calculated by dedicated hardware. This paper describes the
design, the hardware and software implementation and the performance of the
upgraded calorimeter trigger system both at Level 2 and Level 1.Comment: 5 pages, 5 figures,34th International Conference on High Energy
Physics, Philadelphia, 200
Vertical zonation of testate amoebae in the Elatia Mires, northern Greece : palaeoecological evidence for a wetland response to recent climate change or autogenic processes?
The Elatia Mires of northern Greece are unique ecosystems of high conservation value. The mires are climatically marginal and may be sensitive to changing hydroclimate, while northern Greece has experienced a significant increase in aridity since the late twentieth century. To investigate the impact of recent climatic change on the hydrology of the mires, the palaeoecological record was investigated from three near-surface monoliths extracted from two sites. Testate amoebae were analysed as sensitive indicators of hydrology. Results were interpreted using transfer function models to provide quantitative reconstructions of changing water table depth and pH. AMS radiocarbon dates and 210Pb suggest the peats were deposited within the last c. 50 years, but do not allow a secure chronology to be established. Results from all three profiles show a distinct shift towards a more xerophilic community particularly noted by increases in Euglypha species. Transfer function results infer a distinct lowering of water tables in this period. A hydrological response to recent climate change is a tenable hypothesis to explain this change; however other possible explanations include selective test decay, vertical zonation of living amoebae, ombrotrophication and local hydrological change. It is suggested that a peatland response to climatic change is the most probable hypothesis, showing the sensitivity of marginal peatlands to recent climatic change
Brief but Efficient: Acute HIV Infection and the Sexual Transmission of HIV
Background. We examined whether viral dynamics in the genital tract during the natural history of acute human immunodeficiency virus type 1 (HIV-1) infection could explain efficient heterosexual transmission of HIV. Methods. We measured HIV-1 concentration in blood and semen samples from patients with acute and long-term HIV-1 infection. We explored the effect of changes in viral dynamics in semen on the probability of transmission per coital act, using a probabilistic model published elsewhere. Results. Considered over time from infection, semen HIV-1 concentrations, in men with acute infection, increase and decrease in approximate parallel with changes occurring in blood. Modeling suggests that these acute dynamics alone are sufficient to increase probability of heterosexual transmission by 8-10-fold between peak (day 20 after infection, based on the model) and virologic set points (day 54 and later after infection). Depending on the frequency of coitus, men with average semen HIV-1 loads and without sexually transmitted diseases (STDs) would be expected to infect 7%-24% of susceptible female sex partners during the first 2 months of infection. The predicted infection rate would be much higher when either partner has an STD. Conclusions. Empirical biological data strongly support the hypothesis that sexual transmission by acutely infected individuals has a disproportionate effect on the spread of HIV-1 infection. Acute hyperinfectiousness may, in part, explain the current pandemic in heterosexual individual
Spin states of asteroids in the Eos collisional family
Eos family was created during a catastrophic impact about 1.3 Gyr ago.
Rotation states of individual family members contain information about the
history of the whole population. We aim to increase the number of asteroid
shape models and rotation states within the Eos collision family, as well as to
revise previously published shape models from the literature. Such results can
be used to constrain theoretical collisional and evolution models of the
family, or to estimate other physical parameters by a thermophysical modeling
of the thermal infrared data. We use all available disk-integrated optical data
(i.e., classical dense-in-time photometry obtained from public databases and
through a large collaboration network as well as sparse-in-time individual
measurements from a few sky surveys) as input for the convex inversion method,
and derive 3D shape models of asteroids together with their rotation periods
and orientations of rotation axes. We present updated shape models for 15
asteroids and new shape model determinations for 16 asteroids. Together with
the already published models from the publicly available DAMIT database, we
compiled a sample of 56 Eos family members with known shape models that we used
in our analysis of physical properties within the family. Rotation states of
asteroids smaller than ~20 km are heavily influenced by the YORP effect, whilst
the large objects more or less retained their rotation state properties since
the family creation. Moreover, we also present a shape model and bulk density
of asteroid (423) Diotima, an interloper in the Eos family, based on the
disk-resolved data obtained by the Near InfraRed Camera (Nirc2) mounted on the
W.M. Keck II telescope.Comment: Accepted for publication in ICARUS Special Issue - Asteroids: Origin,
Evolution & Characterizatio
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