1,528 research outputs found
INTEGRAL high energy behaviour of 4U 1812-12
The low mass X-ray binary system 4U 1812-12 was monitored with the INTEGRAL
observatory in the period 2003-2004 and with BeppoSAX on April 20, 2000. We
report here on the spectral and temporal analysis of both persistent and burst
emission. The full data set confirms the persistent nature of this burster, and
reveals the presence of emission up to 200 keV. The persistent spectrum is well
described by a comptonization (CompTT) model plus a soft blackbody component.
The source was observed in a hard spectral state with a 1-200 keV luminosity of
2*10^(36) ergs/s and L/LEdd~1% and no meaningful flux variation has been
revealed, as also confirmed by a 2004 RXTE observation. We have also detected 4
bursts showing double peaked profiles and blackbody spectra with temperatures
ranging from 1.9 to 3.1 keV.Comment: 6 pages, 4 figures. Accepted for publication by A&
In vitro evaluation of caseinophosphopeptides from different genetic variants on bone mineralization
Casein phosphopeptides (CPPs) have been shown to enhance calcium solubility and to increase the calcification by in vitro analyses. The aim of our study was to investigate the effects of four selected casein peptides, which differ in the number of phosphorylated serines, on osteoblast mineralization in vitro. The chosen peptides, related to different casein genetic variants, were obtained by chemical synthesis and tested on murine osteoblast cell line (MC3T3-E1). Our results suggest that the distinct peptides in protein hydrolysates may differentially affect calcium deposition in the extracellular matrix and that the genetic variation within the considered peptides is involved in their differential effect
Magnetic and Gravimetric model of Panarea (Aeolian islands )
We show the results of the gravimetric and magnetometric surveys of the Island of Panerea and its archipelago. These geophysical surveys belong to a major multiparametric project for the evaluation of the volcanic and seismic hazard of the island. Panarea is considered a volcanic active area as dimostrated by gas eruption of November 2002 ....
Gli statistici italiani e la "questione della razza"
Ricostruzione del contributo di statistici e demografi alla preparazione dei provvedimenti discriminatori del 1938 e degli effetti di questi sull'articolazione accademica e scientifica della disciplina
Transcriptomic signatures of neuronal differentiation and their association with risk genes for autism spectrum and related neuropsychiatric disorders.
Genes for autism spectrum disorders (ASDs) are also implicated in fragile X syndrome (FXS), intellectual disabilities (ID) or schizophrenia (SCZ), and converge on neuronal function and differentiation. The SH-SY5Y neuroblastoma cell line, the most widely used system to study neurodevelopment, is currently discussed for its applicability to model cortical development. We implemented an optimal neuronal differentiation protocol of this system and evaluated neurodevelopment at the transcriptomic level using the CoNTeXT framework, a machine-learning algorithm based on human post-mortem brain data estimating developmental stage and regional identity of transcriptomic signatures. Our improved model in contrast to currently used SH-SY5Y models does capture early neurodevelopmental processes with high fidelity. We applied regression modelling, dynamic time warping analysis, parallel independent component analysis and weighted gene co-expression network analysis to identify activated gene sets and networks. Finally, we tested and compared these sets for enrichment of risk genes for neuropsychiatric disorders. We confirm a significant overlap of genes implicated in ASD with FXS, ID and SCZ. However, counterintuitive to this observation, we report that risk genes affect pathways specific for each disorder during early neurodevelopment. Genes implicated in ASD, ID, FXS and SCZ were enriched among the positive regulators, but only ID-implicated genes were also negative regulators of neuronal differentiation. ASD and ID genes were involved in dendritic branching modules, but only ASD risk genes were implicated in histone modification or axonal guidance. Only ID genes were over-represented among cell cycle modules. We conclude that the underlying signatures are disorder-specific and that the shared genetic architecture results in overlaps across disorders such as ID in ASD. Thus, adding developmental network context to genetic analyses will aid differentiating the pathophysiology of neuropsychiatric disorders
Exploitation of rubbery electrospun nanofibrous mat for fracture toughness improvement of structural epoxy adhesive bonded joints
The improvement of the fracture toughness of adhesive joints is a key factor in many structural applications. The ability of nylon electrospun nanofibrous mat to act as an adhesive carrier and reinforcing web in adhesive bonding has been demonstrated by the Authors in previous works. It has been shown that the impregnation method developed and refined during the previous studies allow generating high-quality pre-preg nanomats out of a 2k unfilled epoxy resin. By applying this methodology, in the present work, rubbery nanofibrous mats have been adopted for the first time to reinforce and increase the fracture toughness of adhesive joints. Rubbery nanofibers were produced by electrospinning of nitrile butadiene rubber (NBR) and poly(ε-caprolactone) (PCL). The addition of the semi-crystalline polymer (PCL) is exploited to maintain the nanofibrous morphology, which the rubber alone (NBR) would not be able to ensure due to its low glass transition temperature (Tg). The nanofibers thus obtained have been integrated into a two-component high strength epoxy resin for structural applications. S235 steel adherends for Double Cantilever Beam (DCB) tests have been manufactured and sandblasted to improve adhesion. An optimization of the sandblasting parameters (distance, pressure, angle and time) has been carried out evaluating the shear strength and the fracture surfaces on S235 steel Single Lap Joints (SLJ). Finally, DCB tests have been performed to compare the mode I fracture toughness with and without the rubbery electrospun nanomats
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