922 resultados para BIOTIC INTERCHANGE


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Using bidimensional arenas, the construction and spatial dispersion of tunnels constructed by Coptotermes gestroi and Heterotermes tenuis (Rhinotermitidae) was determined under different laboratory conditions. Workers of both species showed an increase of the tunneled area with the rise in temperature. The activity of workers of C gestroi also increased with the rise in soil moisture. Primary tunnels showed a high degree of dispersion in the arenas for all treatments. The presence of food did not influence the tunneling pattern of C. gestroi; but for H. tenuis there was a significant decrease in the number of tunnels. In addition, the type of substrate affected the tunneling pattern in both species. The understanding of food searching strategies of subterranean termites could contribute in the improvement of pest management programs based on the use of toxic baits. (c) 2005 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Biotic interactions between brachiopods and spionid polychaete worms, collected around San Juan Islands (USA), were documented using observations from live-collected individuals and traces of bioerosion found in dead brachiopod shells. Specimens of Terebratalia tranversa (Sowerby), Terebratulina unguicula (Carpenter), Laqueus californianus (Koch), and Hemithiris psittacea (Gmelin) were collected from rocky and muddy substrates, from sites ranging from 14.7-93.3 m in depth. Out of 1,131 specimens, 91 shells showed traces of bioerosion represented by horizontal tubes. Tubes are U-shaped, straight or slightly curved, sometimes branched, with both tube openings communicating externally. on internal surfaces of infested shells, blisters are observed. All brachiopod species yielded tubes, except for H. psittacea. Tubes are significantly more frequent on live specimens, and occur preferentially on larger, ventral valves. This pattern suggests selectivity by the infester rather than a taphonomic bias. Given the mode of life of studied brachiopods (epifaunal, sessile, attached to the substrate, lying on dorsal valve), ventral valves of living specimens should offer the most advantageous location for suspension-feeding infesters. Frequent infestation of brachiopods by parasitic spionids is ecologically and commercially noteworthy because farmed molluscs are also commonly infested by parasitic polychaetes. In addition, brachiopod shells are among the most common marine macroscopic fossils found in the Phanerozoic fossil record. From a paleontological perspective, spionid-infested brachiopod shells may be a prime target for studying parasite-host interactions over evolutionary time scales.

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A total of 99 pregnant cows were divided into eight groups submitted to the following treatments: group I (n = 29) consisted of unvaccinated cows whose calves did not receive a probiotic and was used as control. Group II (n = 10) consisted of vaccinated cows whose calves did not receive a probiotic. Groups III, IV and V (n = 10 neach) consisted of vaccinated cows whose calves received a probiotic for 5, 15 and 30 days, respectively. Groups VI, VII and VIII (n = 10 each) consisted of unvaccinated cows whose calves received a probiotic for 5, 15 and 30 days, respectively. Each animal in the vaccinated groups received two 5.0 ml vaccine doses containing pili K99 and A14 of Escherichia coli by the subcutaneous route. The probiotic containing Lactobacillus acidophilus at the dose of 2.0 x 10(8) live cells in 250 ml milk, was administered orally. All animals were observed clinically and bacteriologically and anti-K99 and anti-A14 antibody titers were determined in serum and colostrum. Mean calf weight was measured at birth and at 30 days of age. The results showed that a combination of the vaccine with the probiotic administered for 15 and 30 days was the most efficient treatment for the control of diarrhea.

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Shells of Bouchardia rosea (Brachiopoda, Rhynchonelliformea) are abundant in Late Holocene death assemblages of the Ubatuba Bight, Brazil, SW Atlantic. This genus is also known from multiple localities in the Cenozoic fossil record of South America. A total of 1211 valves of B. rosea, 2086 shells of sympatric bivalve mollusks (14 nearshore localities ranging in depth from 0 to 30 m), 80 shells of Bouchardia zitteli, San Julián Formation, Paleogene, Argentina, and 135 shells of Bouchardia transplatina, Camacho Formation, Neogene, Uruguay were examined for bioerosion traces. All examined bouchardiid shells represent shallow-water, subtropical marine settings. Out of 1211 brachiopod shells of B. rosea, 1201 represent dead individuals. A total of 149 dead specimens displayed polychaete traces (Caulostrepsis). Live polychaetes were found inside Caulostrepsis borings in 10 life-collected brachiopods, indicating a syn-vivo interaction (Caulostrepsis traces in dead shells of B. rosea were always empty). The long and coiled peristomial palps, large chaetae on both sides of the 5th segment, and flanged pygidium found in the polychaetes are characteristic of the polychaete genus Polydora (Spionidae). The fact that 100% of the Caulostrepsis found in living brachiopods were still inhabited by the trace-making spionids, whereas none was found in dead hosts, implies active biotic interaction between the two living organisms rather than colonization of dead brachiopod shells. The absence of blisters, the lack of valve/site stereotypy, and the fact that tubes open only externally are all suggestive of a commensal relationship. These data document a new host group (bouchardiid rhynchonelliform brachiopods) with which spionids can interact (interestingly, spionid-infested sympatric bivalves have not been found in the study area despite extensive sampling). The syn-vivo interaction indicates that substantial bioerosion may occur when the host is alive. Thus, the presence of such bioerosion traces on fossil shells need not imply a prolonged post-mortem exposure of shells on the sea floor. Also, none of the Paleogene and Neogene Bouchardia species included any ichnological evidence for spionid infestation. This indicates that the Spionidae/ Bouchardia association may be geologically young, although the lack of older records may also reflect limited sampling and/or taphonomic biases.

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Background: Rust caused by Puccinia psidii Winter has been limiting for the establishment of new Eucalyptus plantations, as well as for resprouting of susceptible genetic materials. Identifying host genes involved in defense responses is important to elucidate resistance mechanisms. Reverse transcription-quantitative PCR is the most common method of mRNA quantitation for gene expression analysis. This method generally employs a reference gene as an internal control to normalize results. A good endogenous control transcript shows minimal variation due to experimental conditions. Findings. We analyzed the expression of 13 genes to identify transcripts with minimal variation in leaves of 60-day-old clonal seedlings of two Eucalyptus clones (rust-resistant and susceptible) subjected to biotic (P. psidii) and abiotic (acibenzolar-S-methyl, ASM) stresses. Conclusions. For tissue samples of clones that did not receive any stimulus, a combination of the eEF2 and EglDH genes was the best control for normalization. When pathogen-inoculated and uninoculated plant samples were compared, eEF2 and UBQ together were more appropriate as normalizers. In ASM-treated and untreated leaves of both clones, transcripts of the CYP and elF4B genes combined were the ones with minimal variation. Finally, when comparing expression in both clones for ASM-treated leaves, P. psidii-inoculated leaves, ASM-treated plus P. psidii-inoculated leaves, and their respective controls, the genes with the most stable expression were EgIDH and UBQ. The chitinase gene, which is highly expressed in studies on plant resistance to phytopathogens, was used to confirm variation in gene expression due to the treatments. © 2010 Laia et al; licensee BioMed Central Ltd.

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Information Paper, No 16

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This issue describes progress in EDI in Argentina, Brazil, Chile, Mexico, the United States and Venezuela up to August 1996. The information is based on the progress reports prepared by country representatives for the Pan-American EDIFACT Board (PAEB), which coordinates EDI development activities in the Americas.

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Every port is unique. Although all ports exist for the same basic purpose (to act as an interface in the transfer from one mode of transport to another), no two are ever organized in the same way.Ports may be classified according to: Physical conditions: location (geographical position, man-made or natural harbour, estuary location, difficult weather conditions, tides, etc.) and size (large, small or medium-sized). Use: commercial (general cargo, bulk solids, bulk liquids, oil, break bulk, mixed), passenger, sport and leisure, fishing, mixed, etc. Ownership: private, municipal, regional or State-owned. The Port Authority's role in management of the port: Overall control, i.e. the Port Authority plans, sets up and operates the whole range of services. Facilitator, i.e. the Port Authority plans and sets up the infrastructure and the superstructure, but services are provided by private companies. Landlord, i.e. the Port Authority allows private companies to be responsible for the superstructure and provide port services. Different combinations of port types will therefore give rise to different kinds of organization and different information flows, which means that the associated information systems may differ significantly from port to port. Since this paper relates to the port of Barcelona, with its own specific characteristics, the contents may not always be applicable to other ports.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)