1,961 research outputs found
Early Risk, Attention, and Brain Activation in Adolescents Born Preterm
No full textThe relations among early cumulative medical risk, cumulative environmental risk, attentional control, and brain activation were assessed in 15 – 16-year-old adolescents who were born preterm. Functional magnetic resonance imaging found frontal, temporal, and parietal cortex activation during an attention task with greater activation of the left superior-temporal and left supramarginal gyri associated with better performance. Individual differences in early cumulative risk are related to patterns of brain activation such that medical risk is related to left parietal cortex activation and environmental risk is related to temporal lobe activation. The findings suggest that early risk is related to less mature patterns of brain activation, including reduced efficiency of processing and responding to stimuli.This is the accepted version of the following article: Carmody, D. P., Bendersky, M., Dunn, S. M., DeMarco, J. K., Hegyi, T., Hiatt, M. and Lewis, M. (2006), Early Risk, Attention, and Brain Activation in Adolescents Born Preterm. Child Development, 77: 384–394, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8624.2006.00877.x/abstract.Peer reviewe
’Analysis of microstructure and mechanical properties of aluminium alloys severely deformed by ecap’
No full text’Analysis of microstructure and mechanical properties of aluminium alloys severely deformed by ecap’
No full text
Dynamics on : preperiodic points and pairwise stability
No full textIn [DKY], it was conjectured that there is a uniform bound , depending
only on the degree , so that any pair of holomorphic maps with degree will either share all of their
preperiodic points or have at most in common. Here we show that this
uniform bound holds for a Zariski open and dense set in the space of all pairs,
, for each degree . The proof
involves a combination of arithmetic intersection theory and complex-dynamical
results, especially as developed recently by Gauthier-Vigny, Yuan-Zhang, and
Mavraki-Schmidt. In addition, we present alternate proofs of recent results of
DeMarco-Krieger-Ye and of Poineau. In fact we prove a generalization of a
conjecture of Bogomolov-Fu-Tschinkel in a mixed setting of dynamical systems
and elliptic curves.Comment: minor edit
Internal dynamics of the z ~ 0.8 cluster RX J0152.7-1357
No full textWe present the results from the dynamical analysis of the cluster of galaxies RXJ0152.7−1357, which shows a complex structure in its X-ray
emission, with two major clumps in the central region and a third clump in the Eastern region. Our analysis is based on redshift data for
187 galaxies. We find that RXJ0152.7−1357 appears as a well isolated peak in the redshift space at z = 0.836, which includes 95 galaxies
recognized as cluster members. We compute the line-of-sight velocity dispersion of galaxies, σV = 1322+74
−68 km s−1, which is significantly
larger than what is expected in the case of a relaxed cluster with an observed X-ray temperature of 5-6 keV. We find evidence that this cluster
is far from dynamical equilibrium, as shown by the non Gaussianity of the velocity distribution, the presence of a velocity gradient and a
significant substructure. Our analysis shows that the high value of σV is due to the complex structure of RXJ0152.7−1357, i.e. to the presence
of three galaxy clumps of different mean velocities. Using optical data we detect a low-velocity clump (with σV = 300–500 km s−1) in the
central southwest region and a high-velocity clump (with σV ∼ 700 km s−1) in the Eastern region, corresponding well to the South–West and
East peaks detected in the X-ray emission. The central North–East X-ray peak is associated to the main galaxy structure with a velocity which
is intermediate between those of the other two clumps and σV ∼ 900 km s−1. The mass of the whole system within 2 Mpc is estimated to lie
in the range (1.2−2.2) × 1015 M, depending on the model adopted to describe the cluster dynamics. Such values are comparable to those of
very massive clusters at lower redshifts. Analytic calculations based on the two-body model indicate that the system is most likely bound and
currently undergoing merging. In particular, we suggest that the southwestern clump is not a small group, but rather the dense cluster-core of a
massive cluster, most likely destined to survive tidal disruption during the merger
Ovarian angioma: Three asymptomatic cases.
No full textIn 3 female patients, aged 46, 50 and 74 years respectively, ovarian angiomas measuring 3, 5 and 30 mm in diameter were discover-ed. All the angiomas were asymptomatic. They were either associated with endometrioid carcinoma or uterine leiomyomas, or detected casually by ultrasound scan in a patient with ascites, intrahepatic nodule and increased serologic CA 125. The immunohistochemical studies failed to reveal any affinity between the vascular endothelium of our ovarian angiomas and oestrogen and progesteron receptors
Galaxy pre-processing in substructures around z ∼ 0.4 galaxy clusters
No full textWe present a detailed analysis of galaxy colours in two galaxy clusters at z ∼ 0.4, MACS J0416.1 - 2403 and MACS J1206.2 - 0847, drawn from the CLASH-VLT survey, to investigate the role of pre-processing in the quenching of star formation. We estimate the fractions of red and blue galaxies within the main cluster and the detected substructures and study the trends of the colour fractions as a function of the projected distance from the cluster and substructure centres. Our results show that the colours of cluster and substructure members have consistent spatial distributions. In particular, the colour fractions of galaxies inside substructures follow the same spatial trends observed in the main clusters. Additionally, we find that at large cluster-centric distances (r ≥ r200) the fraction of blue galaxies in both the main clusters and in the substructures is always lower than the average fraction of UVJ-selected star-forming galaxies in the field as measured in the COSMOS/UltraVista data set. We finally estimate environmental quenching efficiencies in the clusters and in the substructures and find that at large distances from the cluster centres, the quenching efficiency of substructures becomes comparable to the quenching efficiency of clusters. Our results suggest that pre-processing plays a significant role in the formation and evolution of passive galaxies in clusters at low redshifts
Triangles in Random Graphs
No full textWe prove four separate results. These results will appear or have appeared in various papers (see [10], [11], [12], [13]). For a gentler introduction to these results, the reader is directed to the first chapter of this thesis. Let G = Gn,p. With ξk = ξ n,p k the number of copies of Kk in G, p ≥ n−2/(k−1) and η> 0, we show when k> 1 Pr(ξk> (1 + η)Eξk) < exp −Ωη,kmin{n2pk−1 log(1/p), nkp
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