978 resultados para Forest Structure


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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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Dissertation presented to obtain the Ph.D degree in Biochemistry, Structural Biochemistry

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Dissertation submitted for obtaining the degree of Master in Environmental Engineering

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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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Increasingly stringed regulations for diesel engine emissions have a significant impact on the required efficiency of DOC. Lowered DOC oxidation efficiency due to thermal aging effects influences the efficiency of the exhaust aftertreatment systems downstream of the DOC. In this work carried out in the Jean Le Rond d’Alembert Institute the effect of hydrothermal aging on the reactivity and structure of a commercial DOC was investigated. The characterization of the catalytic performance was carried out on a synthetic gas bench using carrots catalyst under conditions close to the realistic conditions i.e. using a synthetic gas mixture, representative of the exhaust gases from diesel engines. Different structural characterization techniques were performed: textural and morphological proprieties were analyzed by BET and TEM, the characterization of the presented crystallographic phases was performed by DRX and the determination of the number of reducible species was possible by TPR. TEM results shown, an increase of the metal particle size with the aging caused by the agglomeration of metal particles, revealing the presence of metal sintering. DRX results also suggest the presence of support sintering. Furthermore, DRX and BET results unexpectedly reveal that the most drastic aging conditions used actually activated the catalyst surface. As expected, the aging affected negatively the catalyst performance on the oxidation of methane and CO, however an improvement of the NO oxidation performance with the aging was observed. Nevertheless, for the aging conditions used, catalytic activity results show that the influence of aging in DOC performance was not significant, and therefore, more drastic aging conditions must be used.

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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.

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With the recent advances in technology and miniaturization of devices such as GPS or IMU, Unmanned Aerial Vehicles became a feasible platform for a Remote Sensing applications. The use of UAVs compared to the conventional aerial platforms provides a set of advantages such as higher spatial resolution of the derived products. UAV - based imagery obtained by a user grade cameras introduces a set of problems which have to be solved, e. g. rotational or angular differences or unknown or insufficiently precise IO and EO camera parameters. In this work, UAV - based imagery of RGB and CIR type was processed using two different workflows based on PhotoScan and VisualSfM software solutions resulting in the DSM and orthophoto products. Feature detection and matching parameters influence on the result quality as well as a processing time was examined and the optimal parameter setup was presented. Products of the both workflows were compared in terms of a quality and a spatial accuracy. Both workflows were compared by presenting the processing times and quality of the results. Finally, the obtained products were used in order to demonstrate vegetation classification. Contribution of the IHS transformations was examined with respect to the classification accuracy.

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INTRODUCTION: Malaria is a serious problem in the Brazilian Amazon region, and the detection of possible risk factors could be of great interest for public health authorities. The objective of this article was to investigate the association between environmental variables and the yearly registers of malaria in the Amazon region using Bayesian spatiotemporal methods. METHODS: We used Poisson spatiotemporal regression models to analyze the Brazilian Amazon forest malaria count for the period from 1999 to 2008. In this study, we included some covariates that could be important in the yearly prediction of malaria, such as deforestation rate. We obtained the inferences using a Bayesian approach and Markov Chain Monte Carlo (MCMC) methods to simulate samples for the joint posterior distribution of interest. The discrimination of different models was also discussed. RESULTS: The model proposed here suggests that deforestation rate, the number of inhabitants per km², and the human development index (HDI) are important in the prediction of malaria cases. CONCLUSIONS: It is possible to conclude that human development, population growth, deforestation, and their associated ecological alterations are conducive to increasing malaria risk. We conclude that the use of Poisson regression models that capture the spatial and temporal effects under the Bayesian paradigm is a good strategy for modeling malaria counts.

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An infinite-horizon discrete time model with multiple size-class structures using a transition matrix is built to assess optimal harvesting schedules in the context of Non-Industrial Private Forest (NIPF) owners. Three model specifications accounting for forest income, financial return on an asset and amenity valuations are considered. Numerical simulations suggest uneven-aged forest management where a rational forest owner adapts her or his forest policy by influencing the regeneration of trees or adjusting consumption dynamics depending on subjective time preference and market return rate dynamics on the financial asset. Moreover she or he does not value significantly non-market benefits captured by amenity valuations relatively to forest income.

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INTRODUCTION: This work aimed to study the community structure of sandflies, with regard to the richness, constancy, abundance, and monthly frequency of the species with a focus on the transmission of leishmaniasis. METHODS: The study was conducted in the rural villages of Bom Jardim and Santa Maria, situated on the edge of a tropical rain forest in the municipality of São Jose de Ribamar, Maranhão, Brazil. The phlebotomines were captured in the intradomiciles and peridomiciles of each village, with Centers for Disease Control (CDC) light traps set in 10 homes in each village, for 1 year, once a month, from 18h to 6h. RESULTS: We collected 1,378 individuals of 16 sandfly species. The capture success rate was higher in Bom Jardim (0.61 specimens/hour/trap) than that of Santa Maria (0.35/specimens/hour/trap). The sandflies were more abundant in the peridomiciles (86.1%) and in the rainy season (77%). Five species were considered constants (occurring in more than 50% of samples), 5 accessory (25%-50%), and 6 accidental (<25%). The most abundant species were Lutzomyia longipalpis (59.7%) and L whitmani (28%). The permutation analysis showed differences between the species composition of the villages and no separation between the intradomicile and peridomicile of each village. The species that most contributed to the dissimilarity between the light traps of the 2 villages were L. longipalpis, L. whitmani, and L. evandroi, contributing to 80.8% of the variation among groups. CONCLUSIONS: The high level of richness and abundance of species and the presence of competent vectors throughout the year and around houses justify the occurrence of leishmaniasis cases reported in the area.

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A Work Project, presented as part of the requirements for the Award of a Master’s Double Degree in Finance from Maastricht University and NOVA – School of Business and Economics

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Introduction We analyzed the vertical and monthly distributions of culicid species in the gallery forest of Brasília National Park, with an emphasis on the potential vectors of yellow fever (YF). Methods Between September 2010 and August 2011, mosquitoes were captured on the ground and in the canopy of the forest for five consecutive days per month, from nine to 15 hours. The mosquitoes were examined to verify natural infection with flaviviruses by isolation in Aedes albopictus Skuse, 1864 cells followed by indirect immunofluorescence. Results We identified 2,677 culicids distributed in 29 species. Most of the mosquitoes were captured at ground level (69%) during the rainy season (86%). The most abundant species were Sabethes (Sabethes) albiprivus Theobald, 1903; Limatus durhamii Theobald, 1901; Haemagogus (Conopostegus) leucocelaenus Dyar & Shannon, 1924; Haemagogus (Haemagogus) janthinomys Dyar, 1921; Aedes (Ochlerotatus) scapularis Rondani, 1848; Psorophora (Janthinosoma) ferox Von Humboldt, 1819; and Aedes (Ochlerotatus) serratus Theobald, 1901. Limatus durhamii, Limatus durhamii, Psorophora ferox, Aedes scapularis and Aedes serratus showed significant differences (p<0.05) in their habitat use. Limatus durhamii was found more often in the canopy, unlike the other species. During the rainy season, the most abundant species were Sa. albiprivus, Haemagogus leucocelaenus and Limatus durhamii. During the dry season, the potential YF vectors exhibited a very low frequency and abundance, except Aedes scapularis and Aedes serratus. No flavivirus was detected in the 2,677 examined mosquitoes. Conclusions We recommend continued and systematic entomological monitoring in areas vulnerable to the transmission of YF in the Federal District of Brazil.