7,328 research outputs found
Transcriptome of the deep-sea black scabbardfish, Aphanopus carbo (Perciformes: Trichiuridae) : tissue-specific expression patterns and candidate genes associated to depth adaptation
Deep-sea fishes provide a unique opportunity to study the physiology and evolutionary adaptation to extreme environments. We carried out a high throughput sequencing analysis on a 454 GS-FLX titanium plate using unnormalized cDNA libraries from six tissues of A. carbo. Assemblage and annotations were performed by Newbler and InterPro/Pfam analyses, respectively. The assembly of 544,491 high quality reads provided 8,319 contigs, 55.6% of which retrieved blast hits against the NCBI nonredundant database or were annotated with ESTscan. Comparison of functional genes at both the protein sequences and protein stability levels, associated with adaptations to depth, revealed similarities between A. carbo and other bathypelagic fishes. A selection of putative genes was standardized to evaluate the correlation between number of contigs and their normalized expression, as determined by qPCR amplification. The screening of the libraries contributed to the identification of new EST simple-sequence repeats (SSRs) and to the design of primer pairs suitable for population genetic studies as well as for tagging and mapping of genes. The characterization of the deep-sea fish A. carbo first transcriptome is expected to provide abundant resources for genetic, evolutionary, and ecological studies of this species and the basis for further investigation of depth-related adaptation processes in fishes.Publisher PDFPeer reviewe
Biofouling in tubes: some trends and perspectives
A significant increase in the literature concerning the formation of biological deposits in tubes has been noticed in the last few years. Yet, the scope of the majority of the reports is limited to the study of a single operating parameter. Besides, the operating conditions differ significantly from case to case, renderino difficult the absortion of
the available information.
In this work, a survey of the most recent publications on the subject of tube biofouling is undertaken, as a means of clarifying further
research proprams. Emphasis is placed on the systems used, experimental equipments adopted and, essentially on the parameters studied. Of these, specially attention is qiven to the influence of tube material and roughness, foulant type and concentration, fluid velocity and temperature field
A model for the interpretation of biofouling
The formation of biofilms on heat exchange surfaces
was studied using water with Pseudomonas fluorescens
as a contaminant and also a mixture of these bacteria
and kaolin particles. In every case increasing the
fluid velocity resulted in a decrease in the final
amount of deposit and in the deposition rate . The
effect of the fluid velocity was interpreted using a
mathematical model and it was found that cell
adhesion and reproduction were the fundamental
processes controlling the deposition rate .
The presence of inorganic particles in the
deposit enhanced the biofilm growth rate . This result
was explained by the differences in the structure of
the fouling layers
Fractal Conductance Fluctuations of Classical Origin
In mesoscopic systems conductance fluctuations are a sensitive probe of
electron dynamics and chaotic phenomena. We show that the conductance of a
purely classical chaotic system with either fully chaotic or mixed phase space
generically exhibits fractal conductance fluctuations unrelated to quantum
interference. This might explain the unexpected dependence of the fractal
dimension of the conductance curves on the (quantum) phase breaking length
observed in experiments on semiconductor quantum dots.Comment: 5 pages, 4 figures, to appear in PR
Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial
Light propagation through 1D disordered structures composed of alternating
layers, with random thicknesses, of air and a dispersive metamaterial is
theoretically investigated. Both normal and oblique incidences are considered.
By means of numerical simulations and an analytical theory, we have established
that Anderson localization of light may be suppressed: (i) in the long
wavelength limit, for a finite angle of incidence which depends on the
parameters of the dispersive metamaterial; (ii) for isolated frequencies and
for specific angles of incidence, corresponding to Brewster anomalies in both
positive- and negative-refraction regimes of the dispersive metamaterial. These
results suggest that Anderson localization of light could be explored to
control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure
Etiologia, fatores de risco e aspectos clínicos da mastite ovina.
bitstream/CNPC-2010/22751/1/doc87.pd
Fouling in heat exchangers: a study of the mechanisms of formation of kaolin deposits
Fouling caused by a water-kaolin suspension in an annular heat exchanger was studied. Deposition seemed to be controlled by ma!!s transfer for lower Reynolds numbers and by adhesion for higher Re. The data was
satisfactorily described by the generalized model of Pinheiro.
The relative cohesion of the deposits was measured using a concentric cylinders apparatus, which also helped in confirming the existence of a loose and a hard layer in the kaolin deposits
Quantificação da atividade microbiana e qualidade nutricional do solo em plantio adensado de Nim Indiano (Azadirachta indica A. Juss.) no Território de Identidade Bacia do Paramirim - Semi-árido baiano.
A introdução do Nim indiano na silvicultura brasileira vem sendo popularizada através de práticas de manejo empíricas. Estudos relacionados à produtividade e impactos ambientais motivados pelo adensamento indiscriminado da cultura ainda são insipientes. Um ponto crítico é a capacidade antimicrobiana e inseticida da Azadiractina, principio ativo extraído da parte aérea como inseticida botânico, no controle de pragas e doenças na agricultura.Em paralelo aconteceram também os seguintes eventos: V Seminário de Pesquisa do Recôncavo da Bahia; V Seminário Estudantil de Pesquisa da UFRB; V Seminário da Pós-Graduação da UFRB; II Seminário Regional de Pesquisa da EBDA; 5ª Jornada Científica da Embrapa Mandioca e Fruticultura; VIII Seminário Estudantil de Pesquisa e Extensão da FAMAM; Semana de Ciência, Tecnologia e Inovação no Agronegócio; Fórum de Gestores de Iniciação Científica e Tecnológica da Bahia; II Simpósio Baiano de Defesa Agropecuária; I Semana de Educação Tutorial da UFRB
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