14,062 research outputs found
Características das cultivares de arroz recomendadas para Rondônia.
A EMBRAPA/Centro de Pesquisa Agroflorestal de Rondônia (CPAF-Rondônia) vem conduzindo, anualmente, em colaboração com a EMBRAPA Centro Nacional de Pesquisa de Arroz e Feijão (CNPAF), um Programa de Melhoramento Genético do Arroz, onde procura avaliar e selecionar genótipos agronomicamente superiores, com o objetivo de recomendar aos produtores rondonienses, novas cultivares que apresentam alto potencial produtivo, além de resistência a doenças e ao acamamento, e boa qualidade de grãos.bitstream/item/112982/1/CPAFRO-Documentos-29.pd
An X-ray Atlas of Groups of Galaxies
A search was conducted for a hot intragroup medium in 109 low-redshift galaxy
groups observed with the ROSAT PSPC. Evidence for diffuse, extended X-ray
emission is found in at least 61 groups. Approximately one-third of these
detections have not been previously reported in the literature.
Most of the groups are detected out to less than half of the virial radius
with ROSAT. Although some spiral-rich groups do contain an intragroup medium,
diffuse emission is restricted to groups that contain at least one early-type
galaxy.Comment: 39 pages, 12 figures, to appear in The Astrophysical Journal Sup
Probing dipolar effects with condensate shape oscillation
We discuss the low energy shape oscillations of a magnetic trapped atomic
condensate including the spin dipole interaction. When the nominal isotropic
s-wave interaction strength becomes tunable through a Feshbach resonance (e.g.
as for Rb atoms), anisotropic dipolar effects are shown to be detectable
under current experimental conditions [E. A. Donley {\it et al.}, Nature {\bf
412}, 295 (2001)].Comment: revised version, submitte
Carbon Nitrogen, and Oxygen Galactic Gradients: A Solution to the Carbon Enrichment Problem
Eleven models of Galactic chemical evolution, differing in the carbon,
nitrogen,and oxygen yields adopted, have been computed to reproduce the
Galactic O/H values obtained from H II regions. All the models fit the oxygen
gradient, but only two models fit also the carbon gradient, those based on
carbon yields that increase with metallicity due to stellar winds in massive
stars (MS) and decrease with metallicity due to stellar winds in low and
intermediate mass stars (LIMS). The successful models also fit the C/O versus
O/H evolution history of the solar vicinity obtained from stellar observations.
We also compare the present day N/H gradient and the N/O versus O/H and the
C/Fe, N/Fe, O/Fe versus Fe/H evolution histories of the solar vicinity
predicted by our two best models with those derived from H II regions and from
stellar observations. While our two best models fit the C/H and O/H gradients
as well as the C/O versus O/H history, only Model 1 fits well the N/H gradient
and the N/O values for metal poor stars but fails to fit the N/H values for
metal rich stars. Therefore we conclude that our two best models solve the C
enrichment problem, but that further work needs to be done on the N enrichment
problem. By adding the C and O production since the Sun was formed predicted by
Models 1 and 2 to the observed solar values we find an excellent agreement with
the O/H and C/H values of the solar vicinity derived from H II regions O and C
recombination lines. One of the most important results of this paper is that
the fraction of carbon due to MS and LIMS in the interstellar medium is
strongly dependent on time and on the galactocentric distance; at present about
half of the carbon in the interstellar medium of the solar vicinity has been
produced by MS and half by LIMS.Comment: 34 pages, 6 tables, 7 figures. Accepted for publication in Ap
Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida) to potassium dichromate and sediment particle size
For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K2Cr2O7 in acute tests was similar to that of other organisms. The LC50 (lethal concentration to 50% of the test organisms) medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L-1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments.Visando o uso futuro do copépodo marinho bentônico Tisbe biminiensis em bioensaios toxicológicos de sedimentos na fase sólida, o presente estudo investigou o efeito do sedimento lamoso do estuário de Maracaípe (Nordeste do Brasil). Foram considerados a granolometria e o tóxico de referência dicromato de potássio sobre a espécie. O sedimento lamoso de Maracaípe pode ser usado como controle, uma vez que não interfere no ciclo de vida do copépodo e possui níveis de contaminação de metais que não causariam efeitos biológicos em invertebrados bentônicos. Nem a sobrevivência ou fecundidade foi afetada pelo tamanho do grão, sugerindo que esta espécie pode ser usada com qualquer tipo de sedimento, de lama a areia. A sensibilidade de T. biminiensis ao K2Cr2O7 em testes agudos foi similar a de outros organismos. Os valores de CL50 (concentração letal a 50% dos organismos) para T. biminiensis foram em média 7,51, 4,68 e 3,19 mg L-1 para o Cr em 48, 72 e 96h, respectivamente. Estes resultados sugerem que T. biminiensis é um organismo promissor para uso em avaliações de toxicidade com a fase sólida do sedimento
Variance of bioimpedance analysis measurements with physicalactivity and ingestion of food and water
[resumo][abstract
Identification of a novel deletion in SURF1 gene: Heterogeneity in Leigh syndrome with COX deficiency
Leigh syndrome (LS) is a rare, progressive neurodegenerative mitochondrial disorder of infancy. It is a genetically heterogeneous disease. The mutations in SURF1 gene are the most frequently known cause. Here two cases of LS likely caused by SURF1 gene variants are reported: a 39-year-old male patient with a novel homozygous deletion (c.-11_13del), and a case of a 6-year-old boy with the same deletion and a nonsense mutation (c.868dupT), both in heterozygosity. Blue native PAGE showed absence of assembled complex IV. This is the first report of a variant that may abolish the SURF1 gene initiation codon in two LS patients.info:eu-repo/semantics/publishedVersio
A importância do gerenciamento de resíduos nos laboratórios de pesquisa.
bitstream/item/71415/1/DOC-11.pd
Heat Treated NiP–SiC Composite Coatings: Elaboration and Tribocorrosion Behaviour in NaCl Solution
Tribocorrosion behaviour of heat-treated NiP and NiP–SiC composite coatings was investigated in a 0.6 M NaCl solution. The tribocorrosion tests were performed in a linear sliding tribometer with an electrochemical cell interface. It was analyzed the influence of SiC particles dispersion in the NiP matrix on current density developed, on coefficient of friction and on wear volume loss. The results showed that NiP–SiC composite coatings had a lower wear volume loss compared to NiP coatings. However, the incorporation of SiC particles into the metallic matrix affects the current density developed by the system during the tribocorrosion test. It was verified that not only the volume of co-deposited particles (SiC vol.%) but also the number of SiC particles per coating area unit (and consequently the SiC particles size) have made influence on the tribocorrosion behaviour of NiP–SiC composite coatings
Comportamento diferencial do estado nutricional de cultivares de mamoeiros avaliados por meio das análises de macronutrientes em limbos e pecíolos foliares em condições edafoclimáticas do Amazonas.
Iniciou-se este trabalho com o objetivo geral de introduzir, avaliar e identificar cultivares adaptadas às condições de clima e solo do Estado do Amazonas, portadoras de elevado potencial produtivo e de características agronômicas favoráveis à qualidade, para futuras recomendações aos produtores. Nesta etapa, o objetivo específico foi avaliar o comportamento diferencial de quinze cultivares de mamoeiros em relação aos teores de macronutrientes nos tecidos do limbo foliar e do pecíolo, bem como comparar os teores entre essas duas partes da folha amostradas
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