10,029 research outputs found
Molecular analysis and validation of primitive races peach palm (Bactris gasipaes) by means of markers RAPD
Granular Pressure and the Thickness of a Layer Jamming on a Rough Incline
Dense granular media have a compaction between the random loose and random
close packings. For these dense media the concept of a granular pressure
depending on compaction is not unanimously accepted because they are often in a
"frozen" state which prevents them to explore all their possible microstates, a
necessary condition for defining a pressure and a compressibility
unambiguously. While periodic tapping or cyclic fluidization have already being
used for that exploration, we here suggest that a succession of flowing states
with velocities slowly decreasing down to zero can also be used for that
purpose. And we propose to deduce the pressure in \emph{dense and flowing}
granular media from experiments measuring the thickness of the granular layer
that remains on a rough incline just after the flow has stopped.Comment: 10 pages, 2 figure
The Peyer's patch mononuclear phagocyte system at steady state and during infection
The gut represents a potential entry site for a wide range of pathogens including protozoa, bacteria, viruses, or fungi. Consequently, it is protected by one of the largest and most diversified population of immune cells of the body. Its surveillance requires the constant sampling of its encounters by dedicated sentinels composed of follicles and their associated epithelium located in specialized area. In the small intestine, Peyer's patches (PPs) are the most important of these mucosal immune response inductive sites. Through several mechanisms including transcytosis by specialized epithelial cells called M-cells, access to the gut lumen is facilitated in PPs. Although antigen sampling is critical to the initiation of the mucosal immune response, pathogens have evolved strategies to take advantage of this permissive gateway to enter the host and disseminate. It is, therefore, critical to decipher the mechanisms that underlie both host defense and pathogen subversive strategies in order to develop new mucosal-based therapeutic approaches. Whereas penetration of pathogens through M cells has been well described, their fate once they have reached the subepithelial dome (SED) remains less well understood. Nevertheless, it is clear that the mononuclear phagocyte system (MPS) plays a critical role in handling these pathogens. MPS members, including both dendritic cells and macrophages, are indeed strongly enriched in the SED, interact with M cells, and are necessary for antigen presentation to immune effector cells. This review focuses on recent advances, which have allowed distinguishing the different PP mononuclear phagocyte subsets. It gives an overview of their diversity, specificity, location, and functions. Interaction of PP phagocytes with the microbiota and the follicle- associated epithelium as well as PP infection studies are described in the light of these new criteria of PP phagocyte identification. Finally, known alterations affecting the different phagocyte subsets during PP stimulation or infection are discussed
Desenvolvimento de "inter-retrotransposon amplified polymorphism" para análise de diversidade genética em germoplasma de mandioca.
A mandioca, Manihot esculenta Crantz, possui importância econĂ´mica na maioria dos paĂses tropicais e subtropicais. A variabilidade genĂ©tica da espĂ©cie nĂŁo foi totalmente explorada e novas informações podem ajudar a expandir seu uso. Os marcadores moleculares baseados em retrotransposons, devido a sua abundancia no genoma, permitem uma eficiente análise de diversidade genĂ©tica. O IRAP (Inter-Retrotransposon Amplified Polymorphism) Ă© baseado no polimorfismo entre retrotransposons, possui uma alta reprodutibilidade, elevado nĂvel de polimorfismo e baixo custo. O objetivo deste trabalho foi desenvolver primers para IRAP em mandioca. Oito diferentes retrotransposons do tipo LTR foram selecionados para o desenvolvimento de IRAP e os primers baseados nestes elementos foram denominados de ME_1 a ME_8. Foram analisados 21 indivĂduos (12 de Anori/AM, 6 AnamĂŁ/AM e 3 da Bahia) provenientes do banco de germoplasma de mandioca da Embrapa AmazĂ´nia Ocidental. O percentual de loci polimĂłrficos, heterozigosidade esperada (*h) e o ĂŤndice de Shannon (*I) foram calculados usando o software PopGene 1.31. Dos oito primers desenvolvidos, dois deles (ME_1 e ME_3) produziram poucas e fracas bandas. Os demais primers produziram de 21 a 61 bandas com mĂ©dias de 85% de polimorfismo (65,5 - 97), 0,33 de heterozigosidade (0,24 ? 0,40) e 0,49 de Ăndice de Shannon (0,35 ? 0,57). Dos pares de primers desenhados, ME_4 apresentou os menores valores e o ME_8 os maiores para todos os parâmetros avaliados
Static Cylindrical Matter Shells
Static cylindrical shells composed of massive particles arising from matching
of two different Levi-Civita space-times are studied for the shell satisfying
either isotropic or anisotropic equation of state. We find that these solutions
satisfy the energy conditions for certain ranges of the parameters.Comment: 9 pages, 3 figures, Latex; Final version, To appear in General
Relativity and Gravitatio
The population of variable stars in M54 (NGC6715)
We present new B, V and I CCD time-series photometry for 177 variable stars
in a 13'X 13' field centered on the globular cluster M54 (lying at the center
of the Sagittarius dwarf spheroidal galaxy), 94 of which are newly identified
variables. The total sample is composed of 2 anomalous Cepheids, 144 RR Lyrae
stars (108 RR0 and 36 RR1), 3 SX Phoenicis, 7 eclipsing binaries (5 W UMA and 2
Algol binaries), 3 variables of uncertain classification and 18 long-period
variables. The large majority of the RR Lyrae variables likely belong to M54.
Ephemerides are provided for all the observed short-period variables. The
pulsational properties of the M54 RR Lyrae variables are close to those of
Oosterhoff I clusters, but a significant number of long-period ab type RR Lyrae
are present. We use the observed properties of the RR Lyrae to estimate the
reddening and the distance modulus of M54, E(B-V)=0.16 +/- 0.02 and
(m-M)_0=17.13 +/- 0.11, respectively, in excellent agreement with the most
recent estimates. The metallicity has been estimated for a subset of 47 RR
Lyrae stars, with especially good quality light curves, from the Fourier
parameters of the V light curve. The derived metallicity distribution has a
symmetric bell shape, with a mean of =-1.65 and a standard deviation
sigma=0.16 dex. Seven stars have been identified as likely belonging to the
Sagittarius galaxy, based on their too high or too low metallicity. This
evidence, if confirmed, might suggest that old stars in this galaxy span a wide
range of metallicities.Comment: 15 pages, 11 figures, accepted for publication by MNRA
Radial Velocity and Metallicity of the Globular Cluster IC4499 Obtained with AAOmega
We present radial velocity and metallicity measurements for the far-southern
Galactic globular cluster IC4499. We selected several hundred target red giant
stars in and around the cluster from the 2MASS point source catalog, and
obtained spectra at the near-infrared calcium triplet using the AAOmega
spectrograph. Observations of giants in globular clusters M4, M22, and M68 were
taken to provide radial velocity and metallicity comparison objects. Based on
velocity data we conclude that 43 of our targets are cluster members, by far
the largest sample of IC4499 giants spectroscopically studied. We determine the
mean heliocentric radial velocity of the cluster to be 31.5 plus or minus 0.4
km/s, and find the most likely central velocity dispersion to be 2.5 plus or
minus 0.5 km/s. This leads to a dynamical mass estimate for the cluster of 93
plus or minus 37 thousand solar masses. We are sensitive to cluster rotation
down to an amplitude of about 1 km/s, but no evidence for cluster rotation is
seen. The cluster metallicity is found to be [Fe/H] = -1.52 plus or minus 0.12
on the Carretta-Gratton scale. The radial velocity of the cluster, previously
highly uncertain, is consistent with membership in the Monoceros tidal stream,
but also with a halo origin. The horizontal branch morphology of the cluster is
slightly redder than average for its metallicity, but it is likely not
unusually young compared to other clusters of the halo. The new constraints on
the cluster kinematics and metallicity may give insight into its extremely high
specific frequency of RR Lyrae stars.Comment: Accepted to MNRAS, 13 pages, 9 figure
Variação fenotĂpica em frutos de doze introduções de Cubiu (Solanum sessiliflorum Dunal) avaliadas em Manaus, AM, Brasil
Phenotypic variation in fruits of 12 accessions of cubiu (Solanum sessiliflorum Dunal) evaluated in Manaus, Amazonas, Brazil. The cubiu was domesticated by the amerindians and has considerable economic potential for modern agro-industry. Fruit of 12 accessions werw evaluated to determine differecens among these in yield, fruit shape and dimensions, and several economically important characters ( pulp thickness, juice volume, Brix). There exists considerable variation in all characters evaluated, especially size and number of fruits. Brix varied from 4 to 6 and juice volume from 10 to 30ml, in fruits that varied from 40 to 190 g. There is sufficient variation in these 12 introductions to permit rapid genetic advance during breeding for any agro-industrial requirement.O cubiu foi domesticado pelos amerĂndios e tem potencial econĂ´mico considerável para a agroindĂşstria moderna. Frutos de doze introduções de cubiu foram avaliados em Manaus para determinar as diferenças entre estasformato, dimensões e carateres de importância econĂ´mica (espessura de polpa, volume do suco, grau Brix). Existe considerável variação entre as introduções para todos os carateres avaliados, especialmente tamanho e nĂşmero de frutos. A concentração de sĂłlidos solĂşveis totais variou de 4 a 6 e o volume de suco de 10 a 30 ml em frutos de 40 a 190 g. Conclui-se que estas 12 introduções possuem variação ampla que permite progresso genĂ©tico rápido no melhoramento para qualquer finalidade agroindustrial
Gejala Klinik dan Pemeriksaan Laboratorium pada Pasien Diare di RSUD Koja Agustus-Oktober 2009
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