980 resultados para DRY FOREST FRAGMENTS


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Terrestrial isopods are important and dominant component of meso and macrodecomposer soil communities. The present study investigates the diversity and species composition of terrestrial isopods on three forests on the Serra Geral of the state of Rio Grande do Sul, Brazil. The area has two natural formations (Primary Woodland and Secondary Woodland) and one plantation of introduced Pinus. The pitfall traps operated from March 2001 to May 2002, with two summer periods and one winter. There were 14 sampling dates overall. Of the five species found: Alboscia silveirensis Araujo, 1999, Atlantoscia floridana (van Name, 1940), Benthana araucariana Araujo & Lopes, 2003 (Philoscidae), Balloniscus glaber Araujo & Zardo, 1995 (Balloniscidae) and Styloniscus otakensis (Chilton, 1901) (Styloniscidae); only A. floridana is abundant on all environments and B. glaber is nearly exclusive for the native forests. The obtained data made it possible to infer about population characteristics of this species. The Similarity Analysis showed a quantitative difference among the Secondary forest and Pinus plantation, but not a qualitative one. The operational sex ratio (OSR) analysis for A. floridana does not reveal significant differences in male and female proportions among environments. The reproductive period identified in the present study for A. floridana was from spring to autumn in the primary forest and Pinus plantation and during all year for the secondary forest. The OSR analysis for B. glaber reveals no significant differences in abundance between males and females for secondary forest, but the primary forest was a significant difference. The reproductive period for B. glaber extended from summer to autumn (for primary and secondary forest). This is the first record for Brazil of an established terrestrial isopod population in a Pinus sp. plantation area, evidenced by the presence of young, adults and ovigerous females, balanced sex ratio, expected fecundity and reproduction pattern, as compared to populations from native vegetation areas.

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Leaf litter represents a food source to many organisms that may directly contribute to organic matter decomposition. In addition, the physical presence of these vegetal detritus contributes for the modification of some environmental areas and produce microhabitats that may act as a refuge against predators and desiccation for many animals. The pulmonate gastropod Melampus coffeus (Linnaeus, 1758) (Ellobiidae) is a very common specie in Atlantic Coast mangrove forests and feeds on fallen mangrove leaves. It was hypothesized that the spatial distribution of Melampus coffeus is directly affected by mangrove leaf litter biomass deposition. Thus, this research aimed at evaluating the spatial distribution of these gastropods in relation to the biomass of mangrove leaf litter through a twelve-month period. The study area was established in the middle estuary of Pacoti River, state of Ceará, Brazil where two adjacent zones with different topographic profiles were determined. Samples of Melampus coffeus and leaf litter were collected monthly, throughout a year, from the mangrove ground surface. The results indicated that the presence of twigs in mangrove litter favor the occupation by smaller individuals of M. coffeus, probably because smaller individuals are more susceptible to predator attacks and desiccation than larger ones, and twigs and branches may provide a safe microhabitat.

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ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush species, six tree species were used by P. albogularis as a feeding substrate. Tree use was limited to intermediate heights (11-20 m) and, mainly, to the trunk (40% of observations) and secondary branches (26%). Pygarrhichas albogularis showed a disproportionated use of N. dombeyi and an important use of trees with a greater age structure (DBH 81-100 cm). Nothofagus dombeyi presented a significantly greater tree bark crevice depth than E. cordifolia. In turn, covariance between crevice depth and invertebrate supply in tree bark was positive and significant. We consider bark depth and invertebrate supply to be the proximate causes explaining P. albogularis disproportionated use of Nothofagus dombeyi.

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ABSTRACT Using camera traps and capture/recapture analyses we recorded the presence and abundance of cat species at Turvo State Park, in southern Brazil. Ocelot [Leopardus pardalis (Linnaeus, 1758)] population density was estimated for two areas of the park, with differing management profiles. Density estimates varied from 0.14 to 0.26 indiv. km2. Another five cat species were recorded at very low frequencies, precluding more accurate analyses. We estimate 24 to 45 ocelots occur in the reserve, which is probably too small for long-term maintenance of the population, if isolated. However, if habitat integrity and connectivity between the Park and the Green Corridor of Misiones is maintained, an estimated ocelot population of 1,680 individuals should have long-term viability.

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O órgão odorífero de Athysania hesione (e outras espécies próximas) está situado na face externa da segunda tíbia e compõe-se de uma região estreita tomada de células glandulares, situada no bordo posterior da tíbia cuja superfície externa forma um sulco longitudinal. Na parte proximal do núcleo insere-se um grande pincel distribuidor, cujas cerdas estão deitadas no sulco, onde entram em contato com as escamas odoríferas. Em virtude do enchimento de um saco traqueal, situado no interior da tíbia a pressão da hemolinfa aumenta, causando uma deformação da área de inserção do pincel que, por sua vez, sai do sulco, abrindo-se a fim de possibilitar a evaporação da secração. Depois da função, o pincel volta à posição de repouso graças à elasticidade da cutícula da área de inserção. O órgão é protegido por meio de séries de escamas protetoras de grandes superfícies. A célula glandular, excepcionalmente volumosa, localiza-se entre o sincício da hipoderme e a membrana basal (fig. 5). As células tricogêneas das cerdas do pincel distribuidor e das escamas protetoras possuíram, em épocas filogenéticas, função glandular; encontra-se, ainda hoje, no interior das primeiras, um aparelho excretor (fig. 9), sendo porém o seu núcleo e protoplasma completamente inativos, dando aos mesmo um aspecto de degenração.

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Estudi elaborat a partir d’una estada al Royal Veterinary and Agricultural University of Denmark entre els mesos de Març a Juny del 2006. S’ha investigat l’efecte dels envasats amb atmosferes modificades (MAP), així com la marinació amb vi tint, sobre l’evolució de la contaminació bacteriològica de carns fosques, dures i seques (DFD). Les carns DFD es troben a les canals d’animals que, abans del sacrifici, han estat exposades a activitats musculars prolongades o estrès. Les carns DFD impliquen importants pèrdues econòmiques degut a la contaminació bacteriològica i als problemes tecnològics relacionats amb la alta capacitat de retenció d’aigua. A més a més, és crític per la indústria investigar la diversitat de la contaminació bacteriana, identificar les espècies bacterianes i controlar-les. Però és difícil degut a la inhabilitat per detectar algunes bactèries en medis coneguts, les interaccions entre elles, la complexitat dels tipus de contaminació com són aigua, terra, femtes i l’ambient. La Polymerasa chain reaction- Denaturating Electrophoresis Gel (PCR-DGEE ) pot sobrepassar aquests problemes reflectint la diversitat microbial i les espècies bacterianes. Els resultants han indicat que la varietat bacteriana de la carn incrementava amb els dies d’envasat independentment del mètode d’envasat, però decreixia significativament amb el tractament de marinació amb vi tint. La DGEE ha mostrat diferències en les espècies trobades, indicant canvis en la contaminació bacteriana i les seves característiques en la carn DFD sota els diferents tractaments. Tot i que la marinació és una bona alternativa i solució a la comercialització de carn DFD , estudis de seqüenciació són necessaris per identificar les diferents tipus de bactèries.

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High hydrostatic pressure is being increasingly investigated in food processing. It causes microbial inactivation and therefore extends the shelf life and enhances the safety of food products. Yeasts, molds, and vegetative cells of bacteria can be inactivated by pressures in the range of 200 to 700 MPa. Microorganisms are more or less sensitive to pressure depending on several factors such as type, strain and the phase or state of the cells. In general, Gram-positive organisms are usually more resistant than Gram-negative. High pressure processing modifies the permeability of the cell membrane, the ion exchange and causes changes in morphology and biochemical reactions, protein denaturations and inhibition of genetic mechanisms. High pressure has been used successfully to extend the shelf life of high-acid foods such as refrigerated fruit juices, jellies and jams. There is now an increasing interest in the use of this technology to extend the shelf life of low-acid foods such as different types of meat products.

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By staining females of Anopheles cruzi with fluorescent coloured powders in a forest in the State of Santa Catarina, we showed that they move from canopy to ground and vice-versa to feed. This suggests that in areas where this mosquito is a vector of human and simian malarias sporadic infections of man with monkey plasmodia might be expected.

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Semliki Forest virus (SFV) vectors have been efficiently used for rapid high level expression of several G protein-coupled receptors. Here we describe the use of SFV vectors to express the alpha 1b-adrenergic receptor (AR) alone or in the presence of the G protein alpha q and/or beta 2 and gamma 2 subunits. Infection of baby hamster kidney (BHK) cells with recombinant SFV-alpha 1b-AR particles resulted in high specific binding activity of the alpha 1b-AR (24 pmol receptor/mg protein). Time-course studies indicated that the highest level of receptor expression was obtained 30 hours post-infection. The stimulation of BHK cells, with epinephrine led to a 5-fold increase in inositol phosphate (IP) accumulation, confirming the functional coupling of the receptor to G protein-mediated activation of phospholipase C. The SFV expression system represents a rapid and reproducible system to study the pharmacological properties and interactions of G protein coupled receptors and of G protein subunits.

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Fifty-three patients with histologically proven carcinoma were injected with highly purified [131I]-labeled goat antibodies or fragments of antibodies against carcinoembryonic antigen (CEA). Each patient was tested by external photoscanning 4, 24, 36 and 48 h after injection. In 22 patients (16 of 38 injected with intact antibodies, 5 of 13 with F(ab')2 fragments and 1 of 2 with Fab' fragments), an increased concentration of 131I radioactivity corresponding to the previously known tumor location was detected by photoscanning 36-48 h after injection. Blood pool and secreted radioactivity was determined in all patients by injecting 15 min before scanning, [99mTc]-labeled normal serum albumin and free 99mTc04-. The computerized subtraction of 99mTc from 131I radioactivity enhanced the definition of tumor localization in the 22 positive patients. However, in spite of the computerized subtraction, interpretation of the scans remained doubtful for 12 patients and was entirely negative for 19 additional patients. In order to provide a more objective evaluation for the specificity of the tumor localization of antibodies, 14 patients scheduled for tumor resection were injected simultaneously with [131I]-labeled antibodies or fragments and with [125I]-labeled normal goat IgG or fragments. After surgery, the radioactivity of the two isotopes present either in tumor or adjacent normal tissues was measured in a dual channel scintillation counter. The results showed that the antibodies or their fragments were 2-4 times more concentrated in the tumor than in the normal tissues. In addition, it was shown that the injected antibodies formed immune complexes with circulating CEA and that the amount of immune complexes detectable in serum was roughly proportional to the level of circulating CEA.

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Forest fires are a serious threat to humans and nature from an ecological, social and economic point of view. Predicting their behaviour by simulation still delivers unreliable results and remains a challenging task. Latest approaches try to calibrate input variables, often tainted with imprecision, using optimisation techniques like Genetic Algorithms. To converge faster towards fitter solutions, the GA is guided with knowledge obtained from historical or synthetical fires. We developed a robust and efficient knowledge storage and retrieval method. Nearest neighbour search is applied to find the fire configuration from knowledge base most similar to the current configuration. Therefore, a distance measure was elaborated and implemented in several ways. Experiments show the performance of the different implementations regarding occupied storage and retrieval time with overly satisfactory results.

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Spatio-temporal clusters in 1997?2003 fire sequences of Tuscany region (central Italy) have been identified and analysed by using the scan statistic, a method which was devised to evidence clusters in epidemiology. Results showed that the method is reliable to find clusters of events and to evaluate their significance via Monte Carlo replication. The evaluation of the presence of spatial and temporal patterns in fire occurrence and their significance could have a great impact in forthcoming studies on fire occurrences prediction.

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The distribution of larvae of Simulium goeldii was studies in four streams in upland tropical forest near Manaus, Amazonas, Brazil. In each month 32 points were sampled, each with an area of 30 x 50 cm. The areas of all substrates available were measured at each point. The larvae of S. goeldii were collected and later counted for all substrate types where larvae of this species were found. The available substrates were classified into eight types: dry leaves, green leaves, branches, fruits, detritus, rocks and sand; anly the first four types had larvae present. The Kruskal-Wallis test and analysis of variance indicated that the larvae occupy these substrates differently; the Newman-Keuls identified the following differences in intensity of occupation of the susbstrates: branchs differ from roots, dry leaves and green leaves, and green leaves differ from roots and dry leaves. The highest density of larvae was observed on green leaves. However, because the most abundant substrates in the study area were roots and dry leaves, I suggest that the latter two substrates are the most important ones for the esteblishment of this population of S. goeldii.