721 research outputs found
Control of Pre-mRNA Splicing by the General Splicing Factors PUF60 and U2AF65
Pre-mRNA splicing is a crucial step in gene expression, and accurate recognition of splice sites is an essential part of this process. Splice sites with weak matches to the consensus sequences are common, though it is not clear how such sites are efficiently utilized. Using an in vitro splicing-complementation approach, we identified PUF60 as a factor that promotes splicing of an intron with a weak 3' splice-site. PUF60 has homology to U2AF(65), a general splicing factor that facilitates 3' splice-site recognition at the early stages of spliceosome assembly. We demonstrate that PUF60 can functionally substitute for U2AF(65)in vitro, but splicing is strongly stimulated by the presence of both proteins. Reduction of either PUF60 or U2AF(65) in cells alters the splicing pattern of endogenous transcripts, consistent with the idea that regulation of PUF60 and U2AF(65) levels can dictate alternative splicing patterns. Our results indicate that recognition of 3' splice sites involves different U2AF-like molecules, and that modulation of these general splicing factors can have profound effects on splicing
Biological status and dietary intakes ofiIron, zinc and vitamin A among women and preschool children in rural Burkina Faso
Background Food-based approaches such as biofortification are meant to sustainably address micronutrient deficiencies in poor settings. Knowing more about micronutrient intakes and deficiencies is a prerequisite to designing and evaluating interventions. Objective The objectives of the study were to assess biological status and dietary intakes of iron, zinc and vitamin A among women and children aged 36-59 months in rural Burkina Faso and to study relationships between intake and status to better inform future food-based interventions. Design A cross-sectional survey was carried out in two rural provinces of Burkina Faso on a random cluster sample of 480 mother-child pairs. Dietary data was obtained by 24-hour recalls repeated on a random sub-selection of 37.5% of subjects to allow calculation of nutrient's probability of adequacy (PA). Biomarkers were measured on a sub-sample of 180 mother-child pairs. Blood samples were analyzed for hemoglobin, serum ferritin, soluble transferrin receptors (sTfR), C-reactive protein, alpha-1-glycoprotein, serum zinc concentration (SZnC) and retinol. For each micronutrient the relationship between biomarker and dietary intake was investigated by multiple linear regression models accounting for inflammatory biomarkers. Results Mean PA for iron, zinc and vitamin A was 0.49, 0.87 and 0.21 among women and 0.61, 0.95 and 0.33 among children, respectively. Prevalence of anemia, corrected low serum ferritin and high sTfR was 37.6%, 4.0% and 77.5% among women and 72.1%, 1.5% and 87.6% among children, respectively. Prevalence of low SZnC and corrected low serum retinol was 39.4% and 12.0% among women and 63.7% and 24.8% among children, respectively. There was a tendency for a positive relationship between vitamin A intakes and serum retinol among women (beta = 0.0003, P = 0.06). Otherwise, no link was found between micronutrients biomarkers and intakes. Conclusion Our study depicted different images of micronutrient deficiencies when based on dietary intakes or biomarkers results, thus highlighting the need for more suitable biomarkers and more precise measures of absorbable micronutrient intakes at the individual level. It thus points to challenges in the design and evaluation of future biofortification or other food-based interventions in rural areas of Burkina Faso
The polymer phase of the TDAE-C organic ferromagnet
The high-pressure Electron Spin Resonance (ESR) measurements were preformed
on TDAE-C single crystals and stability of the polymeric phase was
established in the parameter space. At 7 kbar the system undergoes a
ferromagnetic to paramagnetic phase transition due to the pressure-induced
polymerization. The polymeric phase remains stable after the pressure release.
The depolymerization of the pressure-induced phase was observed at the
temperature of 520 K. Below room temperature, the polymeric phase behaves as a
simple Curie-type insulator with one unpaired electron spin per chemical
formula. The TDAE donor-related unpaired electron spins, formerly
ESR-silent, become active above the temperature of 320 K and the Curie-Weiss
behavior is re-established.Comment: Submitted to Phys. Rev.
Critical exponents at the ferromagnetic transition in tetrakis(diethylamino)ethylene-C (TDAE-C)
Critical exponents at the ferromagnetic transition were measured for the
first time in an organic ferromagnetic material tetrakis(dimethylamino)ethylene
fullerene[60] (TDAE-C). From a complete magnetization-temperature-field
data set near we determine the susceptibility and
magnetization critical exponents and respectively, and the field vs. magnetization exponent at of
. Hyperscaling is found to be violated by , suggesting that the onset of ferromagnetism can be
related to percolation of a particular contact configuration of C
molecular orientations.Comment: 5 pages, including 3 figures; to appear in Phys. Rev. Let
Identity development and forgivingness: tests of basic relations and mediational pathways
Adaptive identity development leads to increases in personality traits that allow for social well-being. The current study tested this claim with respect to forgivingness, a dispositional tendency to forgive others. In a sample of university undergraduates (N = 214), we examined the relations between forgivingness and two indicators of identity development: commitment and exploration. Forgivingness uniquely positively related with both identity variables, controlling for the other. Next, we tested mediational models to examine the mechanisms underlying these relationships. Our results suggest that, in part, the association between identity development and forgivingness is mediated by levels of agreeableness and neuroticism, as measured by the Big Five Inventory
Looking on the bright side of life: Gratitude and experiences of interpersonal transgressions in adulthood and daily life
OBJECTIVE: Gratitude plays an important role in individual and social well-being. However, less is known about the link between gratitude and experiences of interpersonal stressors. The current research examined the associations between gratitude and interpersonal transgressions.
METHOD: One cross-sectional study with a broad age range and two daily diary studies (total N = 2,348; total age range: 18-91) were used to test the associations on the between- and within-person level.
RESULTS: A consistent result across all studies was that dispositionally grateful individuals tended to report fewer interpersonal transgressions than less grateful people. In turn, people who generally reported more interpersonal transgressions were less grateful in daily life. Moreover, higher gratitude on one specific day was associated with fewer reported transgressions on the same day. However, the results from the daily diary studies indicated differences between the samples. Whereas gratitude was consistently associated with interpersonal transgressions in one daily diary sample, the findings in the second daily diary sample were less consistent.
CONCLUSION: The present findings suggest that grateful people tend to perceive their social exchanges differently and/or actually experience fewer interpersonal transgressions. Future work is needed to test the underlying mechanisms of this negative association
Superconductivity in Fullerides
Experimental studies of superconductivity properties of fullerides are
briefly reviewed. Theoretical calculations of the electron-phonon coupling, in
particular for the intramolecular phonons, are discussed extensively. The
calculations are compared with coupling constants deduced from a number of
different experimental techniques. It is discussed why the A_3 C_60 are not
Mott-Hubbard insulators, in spite of the large Coulomb interaction. Estimates
of the Coulomb pseudopotential , describing the effect of the Coulomb
repulsion on the superconductivity, as well as possible electronic mechanisms
for the superconductivity are reviewed. The calculation of various properties
within the Migdal-Eliashberg theory and attempts to go beyond this theory are
described.Comment: 33 pages, latex2e, revtex using rmp style, 15 figures, submitted to
Review of Modern Physics, more information at
http://radix2.mpi-stuttgart.mpg.de/fullerene/fullerene.htm
Amplified stretch of bottlebrush-coated DNA in nanofluidic channels
The effect of a cationic-neutral diblock polypeptide on the conformation of single DNA molecules confined in rectangular nanochannels is investigated with fluorescence microscopy. An enhanced stretch along the channel is observed with increased binding of the cationic block of the polypeptide to DNA. A maximum stretch of 85% of the contour length can be achieved inside a channel with a cross-sectional diameter of 200 nm and at a 2-fold excess of polypeptide with respect to DNA charge. With site-specific fluorescence labelling, it is demonstrated that this maximum stretch is sufficient to map large-scale genomic organization. Monte Carlo computer simulation shows that the amplification of the stretch inside the nanochannels is owing to an increase in bending rigidity and thickness of bottlebrush-coated DNA. The persistence lengths and widths deduced from the nanochannel data agree with what has been estimated from the analysis of atomic force microscopy images of dried complexes on silica.Singapore-MIT Alliance for Research and TechnologyNational Science Foundation (U.S.
Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies : the ESCAPE project
Background: Prenatal exposure to air pollutants has been suggested as a possible etiologic factor
for the occurrence of autism spectrum disorder.
Objectives: We aimed to assess whether prenatal air pollution exposure is associated with
childhood autistic traits in the general population.
Methods: Ours was a collaborative study of four European population-based birth/child cohorts—
CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen
oxides (NO2, NOx) and particulate matter (PM) with diameters of ≤ 2.5 μm (PM2.5), ≤ 10 μm
(PM10), and between 2.5 and 10 μm (PMcoarse), and PM2.5 absorbance were estimated for birth
addresses by land-use regression models based on monitoring campaigns performed between 2008
and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively
assessed autistic traits when the child was between 4 and 10 years of age. Children were classified
with autistic traits within the borderline/clinical range and within the clinical range using
validated cut-offs. Adjusted cohort-specific effect estimates were combined using random-effects
meta-analysis.
Results: A total of 8,079 children were included. Prenatal air pollution exposure was not associated
with autistic traits within the borderline/clinical range (odds ratio = 0.94; 95% CI: 0.81, 1.10
per each 10‑μg/m3 increase in NO2 pregnancy levels). Similar results were observed in the different
cohorts, for the other pollutants, and in assessments of children with autistic traits within the
clinical range or children with autistic traits as a quantitative score.
Conclusions: Prenatal exposure to NO2 and PM was not associated with autistic traits in children
from 4 to 10 years of age in four European population-based birth/child cohort studies.NonePublishe
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