456 research outputs found
Visual Binaries in the Orion Nebula Cluster
We have carried out a major survey for visual binaries towards the Orion
Nebula Cluster using HST images obtained with an H-alpha filter. Among 781
likely ONC members more than 60" from theta-1 Ori C, we find 78 multiple
systems (75 binaries and 3 triples), of which 55 are new discoveries, in the
range from 0.1" to 1.5". About 9 binaries are likely line-of-sight
associations. We find a binary fraction of 8.8%+-1.1% within the limited
separation range from 67.5 to 675 AU. The field binary fraction in the same
range is a factor 1.5 higher. Within the range 150 AU to 675 AU we find that T
Tauri associations have a factor 2.2 more binaries than the ONC. The binary
separation distribution function of the ONC shows unusual structure, with a
sudden steep decrease in the number of binaries as the separation increases
beyond 0.5", corresponding to 225 AU. We have measured the ratio of binaries
wider than 0.5" to binaries closer than 0.5" as a function of distance from the
Trapezium, and find that this ratio is significantly depressed in the inner
region of the ONC. The deficit of wide binaries in the central part of the
cluster is likely due to dissolution or orbital change during their passage
through the potential well of the inner cluster region. Many of the companions
are likely to be brown dwarfs.Comment: 27 pages, 10 figures, 2 tables, accepted by the Astronomical Journa
A linkage map for the B-genome of Arachis (Fabaceae) and its synteny to the A-genome
<p>Abstract</p> <p>Background</p> <p><it>Arachis hypogaea </it>(peanut) is an important crop worldwide, being mostly used for edible oil production, direct consumption and animal feed. Cultivated peanut is an allotetraploid species with two different genome components, A and B. Genetic linkage maps can greatly assist molecular breeding and genomic studies. However, the development of linkage maps for <it>A. hypogaea </it>is difficult because it has very low levels of polymorphism. This can be overcome by the utilization of wild species of <it>Arachis</it>, which present the A- and B-genomes in the diploid state, and show high levels of genetic variability.</p> <p>Results</p> <p>In this work, we constructed a B-genome linkage map, which will complement the previously published map for the A-genome of <it>Arachis</it>, and produced an entire framework for the tetraploid genome. This map is based on an F<sub>2 </sub>population of 93 individuals obtained from the cross between the diploid <it>A. ipaënsis </it>(K30076) and the closely related <it>A. magna </it>(K30097), the former species being the most probable B genome donor to cultivated peanut. In spite of being classified as different species, the parents showed high crossability and relatively low polymorphism (22.3%), compared to other interspecific crosses. The map has 10 linkage groups, with 149 loci spanning a total map distance of 1,294 cM. The microsatellite markers utilized, developed for other <it>Arachis </it>species, showed high transferability (81.7%). Segregation distortion was 21.5%. This B-genome map was compared to the A-genome map using 51 common markers, revealing a high degree of synteny between both genomes.</p> <p>Conclusion</p> <p>The development of genetic maps for <it>Arachis </it>diploid wild species with A- and B-genomes effectively provides a genetic map for the tetraploid cultivated peanut in two separate diploid components and is a significant advance towards the construction of a transferable reference map for <it>Arachis</it>. Additionally, we were able to identify affinities of some <it>Arachis </it>linkage groups with <it>Medicago truncatula</it>, which will allow the transfer of information from the nearly-complete genome sequences of this model legume to the peanut crop.</p
COMPORTAMENTO DE CAVALOS ESTABULADOS DO EXÉRCITO BRASILEIRO EM BRASÍLIA
Avaliou-se o comportamento de 36 cavalos estabulados, das raças Brasileiro de Hipismo, Lusitano,Puro Sangue Inglês e Mestiços, nas condições em que são criados no 1º Regimento de Cavalaria da Guarda do Ministério do Exército no Distrito Federal. Os animais foram observados 24 horas por dia, durante seis dias, fazendo-se anotações, de dez em dez minutos, do comportamento de cada animal, mostrando que as quatro raças estudadas tinham vários distúrbios de comportamento. Os cavalos da raça Lusitano apresentaram a menor incidência, e os da raça Mestiço, a menor. Com exceção da raça Lusitano, verificou-se o aumento da atividade durante o dia reduziu a incidência de distúrbios no comportamento dos animais. Os animais da raça Lusitano mostraram-se mais adaptados às condições de criação no 1º Regimento de Cavalaria da Guarda (1ºRCG) do Ministério do Exército no Distrito Federal.
PALAVRAS-CHAVE: Comportamento, distúrbios, eqüino, estabulado, raça
The Role of Inflammatory, Anti-Inflammatory, and Regulatory Cytokines in Patients Infected with Cutaneous Leishmaniasis in Amazonas State, Brazil
The authors discuss in this paper the role of inflammatory, anti-inflammatory, and regulatory cytokines in patients infected with different species of Leishmania in Amazonas State, Brazil. A comparative analysis was made of serum concentrations of these cytokines in the peripheral blood of 33 patients infected with cutaneous leishmaniasis. The isolates were identified as Leishmania guyanensis, L. naiffi, and L. amazonensis. Most (64%) of the patients were male ranging in age from 18 to 58 years. Protein expression profiles of IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α, and IL-17 cytokines were shown to vary significantly between infected and noninfected (control group) individuals and according to the Leishmania species. Infection caused by L. guyanensis accounted for 73% of the cases and patients with this parasite also showed higher concentrations of IL-2, IFN-γ, IL-4, and IL-17 when compared to infection by L. amazonensis. Patients with infection caused by L. naiffi showed higher concentration of the cytokines analyzed when compared to uninfected patients; however, there was no statistically significant difference with the other species analyzed. © 2014 Thaís Tibery Espir et al
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