976 research outputs found
Cobalamin supplementation during in vitro maturation improves developmental competence of sheep oocytes
Abstract Pregnancies obtained by Assisted Reproductive Technologies are at higher risk of miscarriage than those obtained naturally. Previously, we reported impaired placental vascular development of in vitro produced (IVP) sheep embryos and defective DNA methylation in the placentae of those embryos. One reason behind these observed defects may be an impaired One Carbon Metabolism (OCM) The present study was performed to test the hypothesis that Cobalamin (Vitamin B12, an important OCM co-factor) supplementation during IVM corrects DNA methylation of IVP embryos and, consequently, ameliorates placental vasculogenesis. To this aim, embryos derived from oocytes matured with Cobalamin (B12 group) or without (negative control group, −CTR) were transferred to synchronized recipient sheep. At day 20 of pregnancy, collected embryos were morphologically evaluated while placentae were subjected to qPCR and histological analysis. The positive control group (+CTR) consisted of conceptuses obtained from naturally mated sheep. Results showed an increased fertilization rate in the B12 group vs –CTR (69.56% vs 57.91% respectively, P = 0.006) not associated with quantitative improvement in blastocyst and/or implantation rate (44.32% vs 36.67% respectively, P > 0.05). Moreover, Cobalamin supplementation during oocyte IVM ameliorated resulting conceptuses quality, in terms of placental vascularization (vessels' maturity and vasculogenetic factors' expression). The expression of DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) was also improved in placentae from the B12 group. In conclusion, Cobalamin supplementation during oocyte IVM improves IVP embryo quality. These results suggest that Cobalamin should be included in standard IVM media
Emotion regulation after traumatic brain injury: distinct patterns of sympathetic activity during anger expression and recognition
Abstract
OBJECTIVE:
To assess psychological and psychophysiological correlates of emotion recognition and anger experience in participants with traumatic brain injury (TBI).
PARTICIPANTS:
Twenty participants with TBI presenting with anger problems and 22 healthy controls.
PROCEDURES:
Participants were administered tasks assessing emotion recognition (The French Evaluation Task) and anger expression (Anger regulation task). The latter, designed to elicit and modulate anger feelings through verbal recall of a self-experienced event, involved 4 recall conditions that followed a resting period: neutral, uninstructed anger recall, anger rumination, and anger reappraisal.
MEASURES:
Skin conductance levels during recall and a self-report anger questionnaire between each condition.
RESULTS:
In the TBI and control groups, self-reported anger was similarly modulated across emotion regulation conditions. However, only in the TBI group did skin conductance levels significantly increase between neutral and uninstructed anger recall conditions.
CONCLUSIONS:
Impaired emotion regulation in TBI participants could be related to increased levels of autonomic system activity during emotional experience. However, anger feelings in these participants can also be modulated with the use of emotion regulation strategies, including adaptive strategies such as reappraisal. Thus, promoting awareness and management of physiological activation and encouraging cognitive restructuring can be recommended as a component of interventions targeting emotion regulation in TBI patients
Simulating the WFXT sky
We investigate the scientific impact of the Wide Field X-ray Telescope
mission. We present simulated images and spectra of X-ray sources as observed
from the three surveys planned for the nominal 5-year WFXT lifetime. The goal
of these simulations is to provide WFXT images of the extragalactic sky in
different energy bands based on accurate description of AGN populations, normal
and star forming galaxies, groups and clusters of galaxies. The images are
realized using a detailed PSF model, instrumental and physical
backgrounds/foregrounds, accurate model of the effective area and the related
vignetting effect. Thanks to this comprehensive modelization of the WFXT
properties, the simulated images can be used to evaluate the flux limits for
detection of point and extended sources, the effect of source confusion at very
faint fluxes, and in general the efficiency of detection algorithms. We also
simulate the spectra of the detected sources, in order to address specific
science topics which are unique to WFXT. Among them, we focus on the
characterization of the Intra Cluster Medium (ICM) of high-z clusters, and in
particular on the measurement of the redshift from the ICM spectrum in order to
build a cosmological sample of galaxy clusters. The end-to-end simulation
procedure presented here, is a valuable tool in optimizing the mission design.
Therefore, these simulations can be used to reliably characterize the WFXT
discovery space and to verify the connection between mission requirements and
scientific goals. Thanks to this effort, we can conclude on firm basis that an
X-ray mission optimized for surveys like WFXT is necessary to bring X-ray
astronomy at the level of the optical, IR, submm and radio wavebands as
foreseen in the coming decade.Comment: "Proceedings of "The Wide Field X-ray Telescope Workshop", held in
Bologna, Italy, Nov. 25-26 2009. To appear in Memorie della Societa
Astronomica Italiana 2010 (arXiv:1010.5889)
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