1,069 research outputs found
Porcine Hepatitis E
Hepatitis E virus (HEV) is a zoonotic agent that can be transmitted from pigs to humans via consumption of pork and products derived of it. Recently, the European Food Safety Authority (EFSA) has published a scientific opinion urging for measures to prevent Hepatitis E virus (HEV) from entering the food chain
Principles of Anti-infective Dosing in Pregnancy
AbstractPurposeAnti-infectives are among the most commonly prescribed medications in pregnancy. However, detailed information on the pharmacokinetics and pharmacodynamics of these medications in pregnancy is limited, leading to uncertainty among clinicians regarding the tolerability and efficacy of treatments. The purposes of this review were to highlight key physiologic changes during pregnancy that influence drug behavior, and to discuss areas of active research related to anti-infective drugs in pregnancy.MethodsA review of literature in PubMed was performed for topics related to physiologic changes of pregnancy, postcesarean surgical site infections, vaccines in pregnancy, and intrauterine infections. The literature was reviewed and pertinent sources were utilized for this article.FindingsPhysiologic changes during pregnancy may impact drug disposition and efficacy. Cefazolin regimens are the current prophylactic treatment of choice for postcesarean surgical site infections. Vaccines are provided in pregnancy for both maternal and neonatal benefit. Broad-spectrum antibiotics continue to be used as first-line therapy for intrauterine infections.ImplicationsContinued efforts to broaden the knowledge base on anti-infective drug behavior in pregnancy will result in increased therapeutic options for this population
Impact of light on Hypocrea jecorina and the multiple cellular roles of ENVOY in this process
<p>Abstract</p> <p>Background</p> <p>In fungi, light is primarily known to influence general morphogenesis and both sexual and asexual sporulation. In order to expand the knowledge on the effect of light in fungi and to determine the role of the light regulatory protein ENVOY in the implementation of this effect, we performed a global screen for genes, which are specifically effected by light in the fungus <it>Hypocrea jecorina </it>(anamorph <it>Trichoderma reesei</it>) using Rapid Subtraction Hybridization (RaSH). Based on these data, we analyzed whether these genes are influenced by ENVOY and if overexpression of ENVOY in darkness would be sufficient to execute its function.</p> <p>Results</p> <p>The cellular functions of the detected light responsive genes comprised a variety of roles in transcription, translation, signal transduction, metabolism, and transport. Their response to light with respect to the involvement of ENVOY could be classified as follows: (i) ENVOY-mediated upregulation by light; (ii) ENVOY-independent upregulation by light; (iii) ENVOY-antagonized upregulation by light; ENVOY-dependent repression by light; (iv) ENVOY-independent repression by light; and (v) both positive and negative regulation by ENVOY of genes not responsive to light in the wild-type. ENVOY was found to be crucial for normal growth in light on various carbon sources and is not able to execute its regulatory function if overexpressed in the darkness.</p> <p>Conclusion</p> <p>The different responses indicate that light impacts fungi like <it>H. jecorina </it>at several cellular processes, and that it has both positive and negative effects. The data also emphasize that ENVOY has an apparently more widespread cellular role in this process than only in modulating the response to light.</p
Root cortex development is fine-tuned by the interplay of MIGs, SCL3 and DELLAs during arbuscular mycorrhizal symbiosis
Root development is a crucial process that determines the ability of plants to acquire nutrients, adapt to the substrate and withstand changing environmental conditions. Root plasticity is controlled by a plethora of transcriptional regulators that allow, in contrast to tissue development in animals, post-embryonic changes that give rise to new tissue and specialized cells.
One of these changes is the accommodation in the cortex of hyperbranched hyphae of symbiotic arbuscular mycorrhizal (AM) fungi, called arbuscules. Arbuscule-containing cells undergo massive reprogramming to coordinate developmental changes with transport processes.
Here we describe a novel negative regulator of arbuscule development, MIG3. MIG3 induces and interacts with SCL3, both of which modulate the activity of the central regulator DELLA, restraining cortical cell growth. As in a tug-of-war, MIG3-SCL3 antagonizes the function of the complex MIG1-DELLA, which promotes the cell expansion required for arbuscule development, adjusting cell size during the dynamic processes of the arbuscule life cycle.
Our results in the legume plant Medicago truncatula advance the knowledge of root development in dicot plants, showing the existence of additional regulatory elements not present in Arabidopsis that fine-tune the activity of conserved central modules
Relevance of the light signaling machinery for cellulase expression in trichoderma reesei (hypocrea jecorina)
<p>Abstract</p> <p>Background</p> <p>In nature, light is one of the most important environmental cues that fungi perceive and interpret. It is known not only to influence growth and conidiation, but also cellulase gene expression. We therefore studied the relevance of the main components of the light perception machinery of <it>Trichoderma reesei </it>(<it>Hypocrea jecorina</it>), ENV1, BLR1 and BLR2, for production of plant cell wall degrading enzymes in fermentations aimed at efficient biosynthesis of enzyme mixtures for biofuel production.</p> <p>Findings</p> <p>Our results indicate that despite cultivation in mostly dark conditions, all three components show an influence on cellulase expression. While we found the performance of the enzyme mixture secreted by a deletion mutant in <it>env1 </it>to be enhanced, the higher cellulolytic activity observed for <it>Δblr2 </it>is mainly due to an increased secretion capacity of this strain. <it>Δblr1 </it>showed enhanced biomass accumulation, but due to its obviously lower secretion capacity still was the least efficient strain in this study.</p> <p>Conclusions</p> <p>We conclude that with respect to regulation of plant cell wall degrading enzymes, the blue light regulator proteins are unlikely to act as a complex. Their regulatory influence on cellulase biosynthesis involves an alteration of protein secretion, which may be due to adjustment of transcription or posttranscriptional regulation of upstream factors. In contrast, the regulatory function of ENV1 seems to involve adjustment of enzyme proportions to environmental conditions.</p
Diffractive orbits in isospectral billiards
Isospectral domains are non-isometric regions of space for which the spectra
of the Laplace-Beltrami operator coincide. In the two-dimensional Euclidean
space, instances of such domains have been given. It has been proved for these
examples that the length spectrum, that is the set of the lengths of all
periodic trajectories, coincides as well. However there is no one-to-one
correspondence between the diffractive trajectories. It will be shown here how
the diffractive contributions to the Green functions match nevertheless in a
''one-to-three'' correspondence.Comment: 20 pages, 6 figure
Constraining the Spin of the Black Hole in Fairall 9 with Suzaku
We report on the results of spectral fits made to data obtained from a 168
ksec Suzaku observation of the Seyfert-1 galaxy Fairall 9. The source is
clearly detected out to 30 keV. The observed spectrum is fairly simple; it is
well-described by a power-law with a soft excess and disk reflection. A broad
iron line is detected, and easily separated from distinct narrow components
owing to the resolution of the CCDs in the X-ray Imaging Spectrometer (XIS).
The broad line is revealed to be asymmetric, consistent with a disk origin. We
fit the XIS and Hard X-ray Detector (HXD) spectra with relativistically-blurred
disk reflection models. With the assumption that the inner disk extends to the
innermost stable circular orbit, the best-fit model implies a black hole spin
parameter of a = 0.60(7) and excludes extremal values at a high level of
confidence. We discuss this result in the context of Seyfert observations and
models of the cosmic distribution of black hole spin.Comment: Accepted for publication in Ap
SST-GATE: A dual mirror telescope for the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) will be the world's first open
observatory for very high energy gamma-rays. Around a hundred telescopes of
different sizes will be used to detect the Cherenkov light that results from
gamma-ray induced air showers in the atmosphere. Amongst them, a large number
of Small Size Telescopes (SST), with a diameter of about 4 m, will assure an
unprecedented coverage of the high energy end of the electromagnetic spectrum
(above ~1TeV to beyond 100 TeV) and will open up a new window on the
non-thermal sky. Several concepts for the SST design are currently being
investigated with the aim of combining a large field of view (~9 degrees) with
a good resolution of the shower images, as well as minimizing costs. These
include a Davies-Cotton configuration with a Geiger-mode avalanche photodiode
(GAPD) based camera, as pioneered by FACT, and a novel and as yet untested
design based on the Schwarzschild-Couder configuration, which uses a secondary
mirror to reduce the plate-scale and to allow for a wide field of view with a
light-weight camera, e.g. using GAPDs or multi-anode photomultipliers. One
objective of the GATE (Gamma-ray Telescope Elements) programme is to build one
of the first Schwarzschild-Couder prototypes and to evaluate its performance.
The construction of the SST-GATE prototype on the campus of the Paris
Observatory in Meudon is under way. We report on the current status of the
project and provide details of the opto-mechanical design of the prototype, the
development of its control software, and simulations of its expected
performance.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
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