4,440 research outputs found
No indication of porcine reproductive and respiratory syndrome virus (PRRSV) infection in Brazilian swine herds.
Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally important pathogen of economic and veterinary concern. Recent studies estimate a cost of US$664m yearly to United States swine industry 3. PRRS is present throughout the world, with the exception of Australia, New Zealand, Finland, Norway, Sweden and Switzerland 5. Although Brazilian swine production is expressive (fourth pork producer and exporter), there has been no evidence of PRRSV infection in those herds 1. Most of the analysis used serology by commercial ELISA tests in breeding herds to perform prevalence surveys. The objective of this work was to detect PRRSV in samples of sera, plasma or oral fluids (OF) from swine herds, quarantined imported boars and feral pigs from 2008 ? 2012
Crystal Structure of an Anti-Ang2 CrossFab Demonstrates Complete Structural and Functional Integrity of the Variable Domain.
Bispecific antibodies are considered as a promising class of future biotherapeutic molecules. They comprise binding specificities for two different antigens, which may provide additive or synergistic modes of action. There is a wide variety of design alternatives for such bispecific antibodies, including the "CrossMab" format. CrossMabs contain a domain crossover in one of the antigen-binding (Fab) parts, together with the "knobs-and-holes" approach, to enforce the correct assembly of four different polypeptide chains into an IgG-like bispecific antibody. We determined the crystal structure of a hAng-2-binding Fab in its crossed and uncrossed form and show that CH1-CL-domain crossover does not induce significant perturbations of the structure and has no detectable influence on target binding
The problem of repulsive quark interactions - Lattice versus mean field models
We calculate the 2nd and 4th order quark number susceptibilities at zero
baryochemical potential, using a PNJL approach and an approach which includes,
in a single model, quark and hadronic degrees of freedom. We observe that the
susceptibilities are very sensitive to possible quark-quark vector
interactions. Compared to lattice data our results suggest that above any
mean field type of repulsive vector interaction can be excluded from model
calculations. Below our results show only very weak sensitivity on the
strength of the quark and hadronic vector interaction. The best description of
lattice data around is obtained for a case of coexistence of hadronic and
quark degrees of freedom.Comment: 5 pages, 4 figure, version accepted by PL
Supernova Properties from Shock Breakout X-rays
We investigate the potential of the upcoming LOBSTER space observatory (due
circa 2009) to detect soft X-ray flashes from shock breakout in supernovae,
primarily from Type II events. LOBSTER should discover many SN breakout
flashes, although the number is sensitive to the uncertain distribution of
extragalactic gas columns. X-ray data will constrain the radii of their
progenitor stars far more tightly than can be accomplished with optical
observations of the SN light curve. We anticipate the appearance of blue
supergiant explosions (SN 1987A analogs), which will uncover a population of
these underluminous events. We consider also how the mass, explosion energy,
and absorbing column can be constrained from X-ray observables alone and with
the assistance of optically-determined distances. These conclusions are drawn
using known scaling relations to extrapolate, from previous numerical
calculations, the LOBSTER response to explosions with a broad range of
parameters. We comment on a small population of flashes with 0.2 < z < 0.8 that
should exist as transient background events in XMM, Chandra, and ROSAT
integrations.Comment: 14 pages, 9 figures, accepted by MNRAS, presented at AAS 203rd
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Recollecting positive and negative autobiographical memories disrupts working memory.
The present article reports two experiments examining the impact of recollecting emotionally valenced autobiographical memories on subsequent working memory (WM) task performance. Experiment 1 found that negatively valenced recollection significantly disrupted performance on a supra-span spatial WM task. Experiment 2 replicated and extended these findings to a verbal WM task (digit recall), and found that both negative and positive autobiographical recollections had a detrimental effect on verbal WM. In addition, we observed that these disruptive effects were more apparent on early trials, immediately following autobiographical recollection. Overall, these findings show that both positive and negative affect can disrupt WM when the mood-eliciting context is based on autobiographical memories. Furthermore, these results indicate that the emotional disruption of WM can take place across different modalities of WM (verbal and visuo-spatial
Silica in Protoplanetary Disks
Mid-infrared spectra of a few T Tauri stars (TTS) taken with the Infrared
Spectrograph (IRS) on board the Spitzer Space Telescope show prominent narrow
emission features indicating silica (crystalline silicon dioxide). Silica is
not a major constituent of the interstellar medium; therefore, any silica
present in the circumstellar protoplanetary disks of TTS must be largely the
result of processing of primitive dust material in the disks surrouding these
stars. We model the silica emission features in our spectra using the opacities
of various polymorphs of silica and their amorphous versions computed from
earth-based laboratory measurements. This modeling indicates that the two
polymorphs of silica, tridymite and cristobalite, which form at successively
higher temperatures and low pressures, are the dominant forms of silica in the
TTS of our sample. These high temperature, low pressure polymorphs of silica
present in protoplanetary disks are consistent with a grain composed mostly of
tridymite named Ada found in the cometary dust samples collected from the
STARDUST mission to Comet 81P/Wild 2. The silica in these protoplanetary disks
may arise from incongruent melting of enstatite or from incongruent melting of
amorphous pyroxene, the latter being analogous to the former. The high
temperatures of 1200K-1300K and rapid cooling required to crystallize tridymite
or cristobalite set constraints on the mechanisms that could have formed the
silica in these protoplanetary disks, suggestive of processing of these grains
during the transient heating events hypothesized to create chondrules.Comment: 47 pages, 9 figures, to appear in the 1 January, 2009 issue of the
Astrophysical Journa
Dust Properties of Protoplanetary Disks in the Taurus-Auriga Star Forming Region from Millimeter Wavelengths
We present the most sensitive 3 mm-survey to date of protoplanetary disks
carried in the Taurus-Auriga star forming region (average rms of about 0.3
mJy), using the IRAM PdBI. With our high detection rate of 17/19, we provide
the first detections at wavelengths longer than about 1 mm for 12 sources. This
enables us to study statistically the mm SED slopes and dust properties of
faint disks and compare them to brighter disks using a uniform analysis method.
With these new data and literature measurements at sub-millimeter and
millimeter wavelengths, we analyze the dust properties of a sample of 21
isolated disks around T Tauri stars in the Taurus-Auriga star forming region.
Together with the information about the disks spatial extension from sub/mm-mm
interferometric studies, we derive from the observed sub-mm/mm spectral energy
distribution constraints on the dust opacity law at these wavelengths, using
two-layer flared disk models and a self-consistent dust model that takes
properly into account the variation of the dust opacity with grain growth. We
find evidence for the presence in the disk midplane of dust particles that have
grown to sizes as large as at least 1 millimeter in all the disks of our
sample, confirming what was previously observed on smaller brighter objects.
This indicates that the dust coagulation from ISM dust to mm-sized grains is a
very fast process in protoplanetary disks, that appears to occur before a young
stellar object enters the Class II evolutionary stage. Also, the amount of
these large grains in the disk outer regions is stationary throughout all the
Class II evolutionary stage, indicating that mechanisms slowing down the dust
inward migration are playing an important role in the Taurus-Auriga
protoplanetary disks.Comment: 17 pages, 10 figures, accepted for publication in A&
The role of macrophage-inducible C-type lectin in different stages of chronic liver disease
The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease
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Individual differences in emotion elicitation in university examinations: A quasi-experimental study
In a quasi-experimental study, we examined the role of individual differences in the elicitation of emotional states in university examinations. Specifically, we assessed emotional states (a) before the first examination (baseline), (b) after receiving positive or negative feedback, and (c) then, again, before a series of subsequent examinations. We also measured effort in examination preparation and interest for studying. Data were collected during a university course that consisted of seven examinations in one semester; and 94 female students completed the BIS/BAS scales and SPSRQ (to measure sensitivity to punishment, SP, and reward, SR). Results revealed that higher BAS, but not SR, individuals experienced higher positive affect (PA) following positive feedback and they also showed higher levels of interest in studying. More generally, higher BIS and SP individuals experienced higher level of negative affect (NA) and they invested more effort in examination preparation; and both higher levels of SP and SR correlated positively with NA after receiving negative feedback. In addition, following negative feedback, higher BAS individuals experienced lower levels of PA, and higher SR individuals invested less effort in examination preparation. Results are discussed in terms of the reinforcement sensitivity theory (RST) of personality and directions for future research
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