1,393 research outputs found
Multi-Temporal cover patterns using Landsat TM in the Tapajós National Forest and its surroundings: a case study.
Evidence of Ecological Resilience Clusters to climate typology in the Amazon Rainforest: a methodological proposal.
Erosive potential of rains in the climate change scenarios in the upper Taquari River Basin, MS, Brazil.
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Genetic variation in susceptibility to pine wilt disease of maritime pine (Pinus pinaster Aiton) half-sib families
International audienceAbstractKey messageThis paper presents a greenhouse study for assessing the genetic variation in maritime pine (Pinus pinasterAiton) in response to pinewood nematode (Bursaphelenchus xylophilus(Steiner et Buhren) Nickle), which is a causal agent of pine wilt disease. Fifteen out of 96 half-sib families were selected as less susceptible. This experiment is an important first step for creating a resistance breeding program.ContextPine wilt disease is caused by the pinewood nematode (Bursaphelenchus xylophilus (Steiner et Buhren) Nickle), a quarantine pest, and is a concern to maritime pine (Pinus pinaster) in Portugal due to its economic, environmental, and social impacts. This disease is regarded as a major threat to European forests.AimsThis paper aimed to evaluate the genetic variation in maritime pine families that were inoculated with pinewood nematode, identify the most resistant families, and establish the guidelines for a resistance improvement program.MethodsTwo-year-old half-sib progenies obtained from 96 plus trees were inoculated. The plants were monitored for survival on four different dates. The statistical analysis followed the mixed model theory.ResultsGenetic variability of the susceptibility to pine wilt disease was observed. At 157 days after inoculation, the 15 highest genetic ranking families out of 96 were selected, having a predicted survival mean of 15.6% instead of 11.0% on average for the all 96 families.ConclusionThis study allows for the implementation of an improvement program to help control pine wilt disease
Panorama espaço - temporal de fatores de mudança economica, scoial e ambiental na Amazônia: estudo de caso Flona Tapajós.
Políticas públicas voltadas para integrar a Amazônia a outras regiões do Brasil na década de 1970 incluíram a instalação de portos, hidrelétricas e abertura de rodovias como a Transamazônica (BR 230) Cuiabá-Santarém (BR 163) e Belém - Brasília (BR 316), desencadeando um processo intenso de transformações na paisagem, principalmente pelo desflorestamento. Porém, neste mesmo período, também foram delimitadas áreas legalmente protegidas na região, como foi o caso da Floresta Nacional do Tapajós, criada em 1974. O objetivo do trabalho foi avaliar temporal e espacialmente forçantes promotoras de alterações na paisagem. Para tanto, foram utilizados dados secundários analíticos disponíveis em bases do IBGE, bem como informações espaciais disponibilizadas por órgãos públicos em âmbito federal, estadual e municipal. Variáveis topoclimáticas foram utilizadas nas avaliações da dinâmica espaço-temporal com auxílio de análises geoestísticas e modelagem. Os resultados reforçaram o modelo de ocupação denominado "espinha de peixe", tendo as rodovias como eixo de antropização e do aumento progressivo da pressão em Áreas Protegidas. Ao avaliar os cenários para 2030, observa-se os efeitos aos longo dos rios, a oeste do estado do Pará, pelas instalação de portos para escoamento da produção em mercado nacional e internacional
Detecting the presence and concentration of nitrate in water using microwave spectroscopy
Nitrate is a common pollutant in surface waters which water companies must monitor for regulatory and safety reasons. The presence of nitrate in deionised water is detected and concentration estimated from microwave spectroscopy measurements in the range 9kHz-6GHz. Experimental results were obtained for 19 solutions (18 salt solutions in deionised water and 1 deionised water), each measured 10 times with 4001 points (total N=190). The resulting data was randomly assigned into equal parts training and test data (N=95 each). Both regression (for the estimation of nitrate concentration) and classification (for detecting the presence of nitrate) methods were considered, with a rigorous feature selection procedure used to identify two frequencies for each of the classification and regression problems. For detection classification models were applied with nitrate levels binned using 30mg/l as the threshold. A logistic regression model achieved AUROC of 0.9875 on test data and a multi-layer perceptron achieved AUROC of 0.9871. In each case the positive predictive value of the model could be optimised at 100% with sensitivity of 90% and specificity of 100%. For the concentration estimates, a linear regression model was able to explain 42% of the variance in the training data and 45% of the variance in the test data and an MLP model delivered similar performance, explaining 43% of variance in the training data and 47% of variance in the test data. A sensor based on this model would be appropriate for detecting the presence of nitrate above a given threshold but poor at estimating concentration
Relating pseudospin and spin symmetries through charge conjugation and chiral transformations: the case of the relativistic harmonic oscillator
We solve the generalized relativistic harmonic oscillator in 1+1 dimensions,
i.e., including a linear pseudoscalar potential and quadratic scalar and vector
potentials which have equal or opposite signs. We consider positive and
negative quadratic potentials and discuss in detail their bound-state solutions
for fermions and antifermions. The main features of these bound states are the
same as the ones of the generalized three-dimensional relativistic harmonic
oscillator bound states. The solutions found for zero pseudoscalar potential
are related to the spin and pseudospin symmetry of the Dirac equation in 3+1
dimensions. We show how the charge conjugation and chiral
transformations relate the several spectra obtained and find that for massless
particles the spin and pseudospin symmetry related problems have the same
spectrum, but different spinor solutions. Finally, we establish a relation of
the solutions found with single-particle states of nuclei described by
relativistic mean-field theories with scalar, vector and isoscalar tensor
interactions and discuss the conditions in which one may have both nucleon and
antinucleon bound states.Comment: 33 pages, 10 figures, uses revtex macro
Será o Implante de iStent® uma Cirurgia do Canal de Schlemm? Avaliação por OCT Spectral Domain de Segmento Anterior
Introdução: O iStent® “trabecular micro-bypass stent modelo GTS100R/L” tem resultados comprovados na cirurgia do glaucoma de ângulo aberto. Descrito como cirurgia ab interno do canal de Schlemm, visa criar um bypass entre a câmara anterior e este canal, ultrapassando a malha trabecular – principal resistência à drenagem de humor aquoso. Os autores visam estudar o papel do OCT de segmento anterior (SA) na localização do iStent® e uma eventual relação entre o seu posicionamento a eficácia hipotensora.
Material e Métodos: Estudo transversal descritivo em que se avaliaram 17 olhos de 17 doentes submetidos a cirurgia de facoemulsificação combinada com iStent®, com um ano de follow-up. Estudou-se o ângulo irido-corneano com OCT spectral domain de SA (Heidelberg Spectralis®) e realizou-se uma avaliação oftalmológica que incluiu medição da pressão intra-ocular (PIO) com tonómetro de Goldmann e gonioscopia.
Resultados: Em todos os olhos foi possível localizar o iStent® no ângulo da câmara anterior, porém apenas 4 pareciam estar no canal de Schlemm, estando os restantes na malha trabecular ou esporão escleral. Nos 4 olhos com implante no canal verificou-se uma redução média da PIO de 6,0 mmHg relativamente aos valores pré-operatórios, nos restantes essa redução foi 5,36 mmHg. Esta diferença não é estatisticamente significativa (p>0,05).
Conclusões: O OCT spectral domain de SA é um método eficiente para determinar o posicionamento do iStent® no ângulo. Apesar da maioria das extremidades distais dos dispositivos não se encontrarem no canal de Schlemm, estes ultrapassaram a resistência da malha trabecular, pelo que a localização não parece comprometer a eficácia hipotensora.info:eu-repo/semantics/publishedVersio
Self-reported clinical history of misdiagnosed leprosy cases in the State of Mato Grosso, Brzil, 2016-2019
This study aimed to analyze the self-reported clinical history of patients misdiagnosed with leprosy in the State of Mato Grosso, Brazil. This is a cross-sectional study of new leprosy cases diagnosed in the State of Mato Grosso from 2016 to 2019, with individuals who were released from multidrug therapy due to misdiagnosis after starting treatment. Data were collected via telephone interviews. Over the study period, 354 leprosy cases were released from treatment due to misdiagnosis, of which 162 (45.8%) could be interviewed. All interviewees expressed dissatisfaction with their treatment, which prompted them to seek a reevaluation of their diagnosis before they were released due to "misdiagnosis". Among them, 35.8% received a final diagnosis of a musculoskeletal or connective tissue disease - mainly fibromyalgia and degenerative changes in the spine - followed by 13.6% with diagnoses of skin and subcutaneous tissue diseases. For 23.5% of the respondents, no alternative diagnosis was established, whereas 7.4% were later re-diagnosed with leprosy. Fibromyalgia and spinal problems were the most common alternative diagnoses for erroneous leprosy. Although the diagnosis of leprosy is usually clinical and does not require access to technical infrastructure in most cases, some more complex situations require diagnostic support via complementary tests, as well as close collaboration between primary care and reference services
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