998 resultados para Forest fragment


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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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Anopheles (Kerteszia) cruzii has been implicated as the primary vector of human and simian malarias out of the Brazilian Amazon and specifically in the Atlantic Forest regions. The presence of asymptomatic human cases, parasite-positive wild monkeys and the similarity between the parasites infecting them support the discussion whether these infections can be considered as a zoonosis. Although many aspects of the biology of An. cruzii have already been addressed, studies conducted during outbreaks of malaria transmission, aiming at the analysis of blood feeding and infectivity, are missing in the Atlantic Forest. This study was conducted in the location of Palestina, Juquitiba, where annually the majority of autochthonous human cases are notified in the Atlantic Forest of the state of São Paulo. Peridomiciliary sites were selected for collection of mosquitoes in a perimeter of up to 100 m around the residences of human malaria cases. The mosquitoes were analyzed with the purpose of molecular identification of blood-meal sources and to examine the prevalence of Plasmodium. A total of 13,441 females of An. (Ker.) cruzii were collected. The minimum infection rate was calculated at 0.03% and 0.01%, respectively, for P. vivax and P. malariae and only human blood was detected in the blood-fed mosquitoes analyzed. This data reinforce the hypothesis that asymptomatic human carriers are the main source of anopheline infection in the peridomiciliary area, making the probability of zoonotic transmission less likely to happen.

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SUMMARY In this study, Leishmaniaspecies were identified by Polymerase Chain Reaction (PCR). The epidemiology of patients suspected of having American Cutaneous Leishmaniasis in the municipality of Assis Brasil, Acre State, located in the Brazil/Peru/Bolivia triborder was also investigated. By PCR, the DNA of Leishmaniawas detected in 100% of the cases (37 samples) and a PCR-Restriction Fragment Length Polymorphism (RFLP) of the hsp 70gene identified the species in 32 samples: Leishmania (Viannia) braziliensis (65.6%) , L. (V.) shawi (28.1%) , L. (V.) guyanensis (3.1%) and mixed infection L. (V.) guyanensis and L. (Leishmania) amazonensis (3.1%)This is the first report of L. (V.) shawiand L. (L.) amazonensis in Acre. The two predominant species were found in patients living in urban and rural areas. Most cases were found in males living in rural areas for at least three years and involved in rural work. This suggests, in most cases, a possible transmission of the disease from a rural/forest source, although some patients had not engaged in activities associated with permanence in forestall areas, which indicate a possible sandflies adaptation to the periurban setting.

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This paper develops a model of a forest owner operating in an open-city environment, where the rent for developed land is increasing concave in nearby preserved open space and is rising over time reflecting an upward trend in households’ income. Thus, our model creates the possibility of switching from forestry to residential use at some point in the future. In addition it allows the optimal harvest length to vary over time even if stumpage prices and regeneration costs remain constant. Within this framework we examine how adjacent preserved open space and alternative development constraints affect the private landowner´s decisions. We find that in the presence of rising income, preserved open space hastens regeneration and conversion cuts but leads to lower density development of nearby unzoned parcels due to indirect dynamic effects. We also find that both a binding development moratorium and a binding minimum-lot-size policy can postpone regeneration and conversion cut dates and thus help to protect open space even if only temporarily. However, the policies do not have the same effects on development density of converted forestland. While the former leads to high-density development, the latter encourages low-density development.

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This paper aims at building a theoretical framework to examine the impact of development pressure on private owner’s forest management practices, namely, on regeneration and conversion cut dates. As the rent for developed land is rising over time, our model creates the possibility of switching from forestry to residential use at some point in the future, thus departing from the Faustmann’s traditional setup. Comparative statics results with respect to stumpage prices, regeneration costs and urban growth parameters are provided. The results obtained depend on the impact on the opportunity cost of holding the stand and the impact on the opportunity cost of holding the land, generalizing Faustmann’s unambiguous results.

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Fluids in which Mycobacterium tuberculosis are seldom found, such as pleural and cerebrospinal liquids, are good candidates to be studied using PCR techniques. We detail our experience with a PCR assay applied to pleural and cerebrospinal fluids using the primer MPB64. Seventy three specimens were analyzed: 30 pleural fluids (PF), 26 pleural biopsies (PB) and 17 cerebrospinal fluids (CSF). The gold standard for the diagnosis of tuberculous meningitis was the positive culture for M. tuberculosis in CSF. Tuberculous pleural effusion was diagnosed when cultures of PF and/or PB were positive for M. tuberculosis, or the PB histology showed granulomas. Our results, compared to the gold standards employed, showed a sensitivity of 70%, specificity of 88%, positive predictive value of 82% and negative predictive value of 80%. The high specificity of the MPB64 fragment while still retaining a good sensitivity makes it very well suited for pleural and cerebrospinal tuberculosis diagnosis.

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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The phlebotomine sandfly fauna of a primary forest reserve at Morretes (eastern Paraná State) was studied, using CDC-like light traps, one night per month, at canopy and ground level, between April 1995 and March 1996. A total of 3,106 insects were collected, identified as belonging to nine species. Lutzomyia ayrozai and Lu.geniculata were predominant, seven other species also being present. Monthly mean temperature, rainfall and the temperature of the collection night significantly influenced the numbers of Lu. ayrozai while the two first factors influenced the numbers of Lu. geniculata, besides the collected quantities of females of the two species. The influence of the factors on Lu. ayrozai numbers was more immediate than in those of Lu. geniculata. Numbers of both species and of the females of Lu. geniculata collected in different seasons, but not at the different heights, varied significantly. Differences between the behaviour of Lu. ayrozai in Morretes and in other regions could be attributed to environmental differences and/or to regional variations in the species, which could constitute species complexes. Hourly variations of collections were different in the species and seasons.

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We sequenced the internal transcribed spacer 2 of the ribosomal DNA (ITS2-DNAr) from the three Schistosoma mansoni intermediate hosts in Brazil: Biomphalaria glabrata, Biomphalaria tenagophila and Biomphalaria straminea. Analysis of a restriction map from those sequences allowed us to select putative restriction enzymes able to identify the snail species under study. Four restriction enzymes were used and HpaII provided simple species-specific profiles easily visualized in polyacrylamide gels. The use of ITS2 is advantageous as it provides a small fragment of 460 bp which may be easily amplified by PCR. In the current work, we showed that the amplification of ITS2-DNAr together with HpaII enzyme restriction is an auxiliary molecular tool for the morphological identification of such snails as well as for taxonomic and phylogenetic studies of neotropical planorbids.

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A positive coefficient of association (affinity) between Runchomyia reversa and Anopheles cruzii and high (0.38) index were observed, probably due to the similar breeding places (bromeliads) and to landing habits. Furthermore, a high (0.92) index of association between Oc. scapularis and Wyeomyia incaudata, with low coefficient of association was observed.

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Mosquitoes (22 species) (0.5%) and Runchomyia reversa (5%) biting humans in the morning in Florianópolis, State of Santa Catarina, were significantly more common below than above waist and all Wyeomyia incaudata were collected below the waist. Short trousers are not recommended, unless using repellents.

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Climate change is emerging as one of the major threats to natural communities of the world’s ecosystems; and biodiversity hotspots, such as Madeira Island, might face a challenging future in the conservation of endangered land snails’ species. With this thesis, progresses have been made in order to properly understand the impact of climate on these vulnerable taxa; and species distribution models coupled with GIS and climate change scenarios have become crucial to understand the relations between species distribution and environmental conditions, identifying threats and determining biodiversity vulnerability. With the use of MaxEnt, important changes in the species suitable areas were obtained. Laurel forest species, highly dependent on precipitation and relative humidity, may face major losses on their future suitable areas, leading to the possible extinction of several endangered species, such as Leiostyla heterodon. Despite the complexity of the biological systems, the intrinsic uncertainty of species distribution models and the lack of information about land snails’ functional traits, this analysis contributed to a pioneer study on the impacts of climate change on endemic species of Madeira Island. The future inclusion of predictions of the effect of climate change on species distribution as part of IUCN assessments could contribute to species prioritizing, promoting specific management actions and maximizing conservation investment.

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The first reported case of an accident with Bothriopsis taeniata in Brazil is described. The victim, a 43-year-old man, was bitten just above his right heel and presented a clinical condition compatible with mild Bothrops poisoning: local edema with hemorrhage at the bite site and pain, although without coagulopathy.

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The forest has a crucial ecological role and the continuous forest loss can cause colossal effects on the environment. As Armenia is one of the low forest covered countries in the world, this problem is more critical. Continuous forest disturbances mainly caused by illegal logging started from the early 1990s had a huge damage on the forest ecosystem by decreasing the forest productivity and making more areas vulnerable to erosion. Another aspect of the Armenian forest is the lack of continuous monitoring and absence of accurate estimation of the level of cuts in some years. In order to have insight about the forest and the disturbances in the long period of time we used Landsat TM/ETM + images. Google Earth Engine JavaScript API was used, which is an online tool enabling the access and analysis of a great amount of satellite imagery. To overcome the data availability problem caused by the gap in the Landsat series in 1988- 1998, extensive cloud cover in the study area and the missing scan lines, we used pixel based compositing for the temporal window of leaf on vegetation (June-late September). Subsequently, pixel based linear regression analyses were performed. Vegetation indices derived from the 10 biannual composites for the years 1984-2014 were used for trend analysis. In order to derive the disturbances only in forests, forest cover layer was aggregated and the original composites were masked. It has been found, that around 23% of forests were disturbed during the study period.