662 research outputs found
Understanding children’s constructions of meanings about other children: implications for inclusiveeducation
This paper explores the factors that influence the way children construct meanings about other children, and especially those who seem to experience marginalisation, within school contexts. The research involved an ethnographic study in a primary school in Cyprus over a period of 5 months. Qualitative methods were used, particularly participant observations and interviews with children. Interpretation of the data suggests that children's perceptions about other children, and especially those who come to experience marginalisation, are influenced by the following factors: other children and the interactions between them; adults’ way of behaving in the school; the existing structures within the school; and the cultures of the school and the wider educational context. Even though the most powerful factor was viewed to be the adults’ influence, it was rather the interweaving between different factors that seemed to lead to the creation of particular meanings for other children. In the end, it is argued that children's voices should be seen as an essential element within the process of developing inclusive practices.<br/
Accelerator and Reactor Neutrino Oscillation Experiments in a Simple Three-Generation Framework
We present a new approach to the analysis of neutrino oscillation
experiments, in the one mass-scale limit of the three-generation scheme. In
this framework we reanalyze and recombine the most constraining accelerator and
reactor data, in order to draw precise bounds in the new parameter space. We
consider our graphical representations as particularly suited to show the
interplay among the different oscillation channels. Within the same framework,
the discovery potential of future short and long baseline experiments is also
investigated, in the light of both the recent signal from the LSND experiment
and the atmospheric neutrino anomaly.Comment: uuencoded compressed tar file. Figures (13) available by ftp to
ftp://eku.sns.ias.edu/pub/lisi/ (192.16.204.30). Submitted to Physical Review
The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast
The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1) is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase
Strabismus regulates asymmetric cell divisions and cell fate determination in the mouse brain
The planar cell polarity (PCP) pathway organizes the cytoskeleton and polarizes cells within embryonic tissue. We investigate the relationship between PCP signaling and cell fate determination during asymmetric division of neural progenitors (NPs) in mouse embryos. The cortex of Lp/Lp (Loop-tail) mice deficient in the essential PCP mediator Vangl2, homologue of Drosophila melanogaster Strabismus (Stbm), revealed precocious differentiation of neural progenitors into early-born neurons at the expense of late-born neurons and glia. Although Lp/Lp NPs were easily maintained in vitro, they showed premature differentiation and loss of asymmetric distribution of Leu-Gly-Asn–enriched protein (LGN)/partner of inscuteable (Pins), a regulator of mitotic spindle orientation. Furthermore, we observed a decreased frequency in asymmetric distribution of the LGN target nuclear mitotic apparatus protein (NuMa) in Lp/Lp cortical progenitors in vivo. This was accompanied by an increase in the number of vertical cleavage planes typically associated with equal daughter cell identities. These findings suggest that Stbm/Vangl2 functions to maintain cortical progenitors and regulates mitotic spindle orientation during asymmetric divisions in the vertebrate brain
Energy Spectra of Elemental Groups of Cosmic Rays: Update on the KASCADE Unfolding Analysis
The KASCADE experiment measures extensive air showers induced by cosmic rays
in the energy range around the so-called knee. The data of KASCADE have been
used in a composition analysis showing the knee at 3-5 PeV to be caused by a
steepening in the light-element spectra. Since the applied unfolding analysis
depends crucially on simulations of air showers, different high energy hadronic
interaction models (QGSJet and SIBYLL) were used. The results have shown a
strong dependence of the relative abundance of the individual mass groups on
the underlying model. In this update of the analysis we apply the unfolding
method with a different low energy interaction model (FLUKA instead of GHEISHA)
in the simulations. While the resulting individual mass group spectra do not
change significantly, the overall description of the measured data improves by
using the FLUKA model. In addition data in a larger range of zenith angle are
analysed. The new results are completely consistent, i.e. there is no hint to
any severe problem in applying the unfolding analysis method to KASCADE data.Comment: accepted for publication in Astroparticle Physic
Transcriptional Activation of Pyoluteorin Operon Mediated by the LysR-Type Regulator PltR Bound at a 22 bp lys Box in Pseudomonas aeruginosa M18
Pseudomonas aeruginosa M18, a rhizosphere-isolated bacterial strain showing strong antifungal activity, can produce secondary metabolites such as phenazine-1-carboxylic acid and pyoluteorin (Plt). The LysR-type transcriptional regulator PltR activates the Plt biosynthesis operon pltLABCDEFG, the expression of which is induced by Plt. Here, we identified and characterized the non-conserved pltL promoter (pltLp) specifically activated by PltR and its upstream neighboring lys box from the complicated pltR–pltL intergenic sequence. The 22 bp palindromic lys box, which consists of two 9 bp complementary inverted repeats interrupted by 4 bp, was found to contain the conserved, GC-rich LysR-binding motif (T-N11-A). Evidence obtained in vivo from mutational and lacZ report analyses and in vitro from electrophoretic mobility shift assays reveals that the PltR protein directly bound to the pltLp region as the indispensable binding motif “lys box”, thereby transcriptionally activating the pltLp-driven plt operon expression. Plt, as a potential non-essential coinducer of PltR, specifically induced the pltLp expression and thus strengthened its biosynthetic plt operon expression
Pion emission from the T2K replica target: method, results and application
The T2K long-baseline neutrino oscillation experiment in Japan needs precise
predictions of the initial neutrino flux. The highest precision can be reached
based on detailed measurements of hadron emission from the same target as used
by T2K exposed to a proton beam of the same kinetic energy of 30 GeV. The
corresponding data were recorded in 2007-2010 by the NA61/SHINE experiment at
the CERN SPS using a replica of the T2K graphite target. In this paper details
of the experiment, data taking, data analysis method and results from the 2007
pilot run are presented. Furthermore, the application of the NA61/SHINE
measurements to the predictions of the T2K initial neutrino flux is described
and discussed.Comment: updated version as published by NIM
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
NA61/SHINE facility at the CERN SPS: beams and detector system
NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a multi-purpose
experimental facility to study hadron production in hadron-proton,
hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton
Synchrotron. It recorded the first physics data with hadron beams in 2009 and
with ion beams (secondary 7Be beams) in 2011.
NA61/SHINE has greatly profited from the long development of the CERN proton
and ion sources and the accelerator chain as well as the H2 beamline of the
CERN North Area. The latter has recently been modified to also serve as a
fragment separator as needed to produce the Be beams for NA61/SHINE. Numerous
components of the NA61/SHINE set-up were inherited from its predecessors, in
particular, the last one, the NA49 experiment. Important new detectors and
upgrades of the legacy equipment were introduced by the NA61/SHINE
Collaboration.
This paper describes the state of the NA61/SHINE facility - the beams and the
detector system - before the CERN Long Shutdown I, which started in March 2013
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