34,070 research outputs found
Are Magnetic Wind-Driving Disks Inherently Unstable?
There have been claims in the literature that accretion disks in which a
centrifugally driven wind is the dominant mode of angular momentum transport
are inherently unstable. This issue is considered here by applying an
equilibrium-curve analysis to the wind-driving, ambipolar diffusion-dominated,
magnetic disk model of Wardle & Konigl (1993). The equilibrium solution curves
for this class of models typically exhibit two distinct branches. It is argued
that only one of these branches represents unstable equilibria and that a real
disk/wind system likely corresponds to a stable solution.Comment: 5 pages, 2 figures, to be published in ApJ, vol. 617 (2004 Dec 20).
Uses emulateapj.cl
Inequality of outcomes and inequality of opportunities in Brazil
The authors depart from John Roemer's theory of equality of opportunities. They seek to determine what part of observed outcome inequality may be attributed to differences in observed"circumstances,"including family background, and what part is due to"personal efforts."The authors use a microeconometric technique to simulate what the distribution of outcomes would look like if circumstances were the same for everybody. They apply this technique to Brazilian data from the 1996 household survey, both for earnings and for household incomes. The authors show that observed circumstances are a major source of outcome inequality in Brazil, probably more so than in other countries for which information is available. Nevertheless, the level of inequality after observed circumstances are equalized remains very high in Brazil.Economic Theory&Research,Public Health Promotion,Curriculum&Instruction,Teaching and Learning,Health Monitoring&Evaluation,Health Monitoring&Evaluation,Teaching and Learning,Economic Theory&Research,Inequality,Poverty Impact Evaluation
Parallel Mean Curvature Surfaces in Symmetric Spaces
We present a reduction of codimension theorem for surfaces with parallel mean
curvature in symmetric spaces
Effect of Rootstock on the Incidence of Dying Arm of Chenin blanc vines
A survey was conducted over a period of three seasons to determine the incidence of dying arm on Vi tis vinifera L. cv. Chenin blanc grafted on 11 rootstock cultivars in an existing rootstock trial. A significant seasonal increase in dying arm was observed from 1979 to 1981. Fewer vines with dying arm symptoms occured where Chenin blanc was grafted on V. rupestris cv. Rupestris du Lot and V. champini cv. Ramsey compared to the rest of the rootstock cultivars. Chenin blanc grafted on 101-14 Mgt and 3306 C rootstocks exhibited the highest incidence of dying arm symptoms. This difference in disease incidence in rootstock cultivars is of utmost importance and could be helpful in controlling the disease
Anomalous diffusion: A basic mechanism for the evolution of inhomogeneous systems
In this article we review classical and recent results in anomalous diffusion
and provide mechanisms useful for the study of the fundamentals of certain
processes, mainly in condensed matter physics, chemistry and biology. Emphasis
will be given to some methods applied in the analysis and characterization of
diffusive regimes through the memory function, the mixing condition (or
irreversibility), and ergodicity. Those methods can be used in the study of
small-scale systems, ranging in size from single-molecule to particle clusters
and including among others polymers, proteins, ion channels and biological
cells, whose diffusive properties have received much attention lately.Comment: Review article, 20 pages, 7 figures. arXiv admin note: text overlap
with arXiv:cond-mat/0201446 by other author
Characterization of a rare analphoid supernumerary marker chromosome in mosaic
Abstract publicado em: Chromosome Research. 2015;23(Suppl 1):67-8. doi:10.1007/s10577-015-9476-6Analphoid supernumerary marker chromosomes (SMCs) are a rare subclass of SMCs C-band-negative
and devoid of alpha-satellite DNA. These marker chromosomes cannot be identified unambiguously by conventional banding techniques alone being necessary to apply molecular cytogenetic methods in favour of a detailed characterization. In this work we report an analphoid SMC involving the terminal long arm of chromosome 7, in 9 years-old boy with several dysmorphic features and severe development delay.
Cytogenetic analysis revealed a mosaic karyotype with the presence of an extra SMC, de novo, in 20 %
of lymphocytes and 73 % of fibroblast cells. FISH analysis with alpha-satellite probes for all chromosomes, whole chromosome painting probe for chromosome 7, and D7S427 and TelVysion 7q probes, allowed
establishing the origin of the SMC as an analphoidmarker resulting of an invdup rearrangement of 7q36-qter region. Affimetrix CytoScan HD microarray analysis, redefined the SMC to arr[hg19] 7q35(143696249-159119707)×2~3, which correspond to a gain of 15.42 Mb and encloses 67 OMIM genes, 16 of which are associated to disease. This result, combined with detailed clinical description, will provide an important means for better genotype-phenotype correlation and a more suitable genetic counselling to the patient and his parents, despite the additional difficulty resulting from being a mosaic (expression varies in different tissues). Analphoid SMCs derived from chromosome 7 are very rare, with only three cases reported so far. With this case we hope contribute to a better understanding of this type of chromosome rearrangements which are difficult for genetic counselling
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