209 resultados para undetected
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Medicina Veterinária - FMVZ
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Nos últimos 30 anos no Brasil, o mapeamento de camada bauxítica tem sido sempre efetuado através de perfilagens de poços. Neste estudo, aplicou-se o método da sísmica de refração rasa pela primeira vez, em cerca de 3.000m de perfis, em caráter experimental em algumas localidades ao longo da rodovia BR-10, assim como no Platô Esperança (região de Jabuti-PA) e perto da cidade de Açailândia (MA); com objetivo de delimitar a camada de bauxita. Embora se tenha utilizado, em algumas ocasiões, durante a interpretação, o método de distância crítica no cálculo de profundidade, foi possível, mediante o emprego do Método Recíproco Generalizado (GRM), o processamento e interpretação dos dados, para se obter a delimitação contínua da camada investigada. O GRM apresenta vantagens sobre os métodos tradicionais, tais como poder delimitar camadas onduladas, detetar camadas escondidas, além da sensibilidade para camadas com mergulho até 20°. A partir dós gráficos da análise de velocidade, foi calculada para a camada de bauxita uma velocidade média de 840 m/s, e mediante o emprego dos tempos de profundidade chegou-se a sua delimitação: ela possui um comportamento irregular, tendo uma espessura média de 5m. A pesquisa geofísica realizada nas três áreas-piloto tem grande importância porque o método utilizado poderá ser aplicado a outras regiões, em condições geológicas semelhantes.
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The goal of this paper is to present a methodology for quality control of horizontal geodetic networks through robustness and covariance analysis. In the proposed methodology, the positional accuracy of each point is estimated by a possible bias in their position (based on robustness analysis), in addition to its own positional precision (uncertainty) (through covariance analysis), being a measure independently from the choice of the datum. Besides presenting the theoretical development of the method, its application is demonstrated in a numerical example. The results indicate that, in general, the greater the distance of an unknown point to the control(s) point(s) of the network, the greater is the propagation of random errors on this unknown point, and the smaller the number of redundant observations around a unknown point, the greater the influence of possible (undetected) non-random errors on this point.
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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Interest in the epidemiology of emerging diseases of humans and livestock as they relate to wildlife has increased greatly over the past several decades. Many factors, most anthropogenic, have facilitated the emergence of diseases from wildlife. Some livestock diseases have ‘‘spilled over’’ to wildlife and then ‘‘spilled back’’ to livestock. When a population is exposed to an infectious agent, depending on an interaction of factors involving the host, agent, and environment, the population may be resistant to infection or may become a dead-end host, a spillover host, or a maintenance host. Each exposure is unique; the same species of host and agent may respond differently in different situations. Management actions that affect the environment and behavior of a potential host animal may allow the emergence of a new or as yet undetected disease. There are many barriers in preventing, detecting, monitoring and managing wildlife diseases. These may include political and legal hurdles, lack of knowledge about many diseases of wildlife, the absence of basic data on wildlife populations, difficulties with surveillance, and logistical constraints. Increasing interaction between wildlife and humans or domestic animals may lead to disease emergence and require innovative methods and strategies for disease surveillance and management in wildlife.
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Polymerase chain reaction techniques were developed and applied to identify DNA from .40 species of prey contained in fecal (scat) soft-part matrix collected at terrestrial sites used by Steller sea lions (Eumetopias jubatus) in British Columbia and the eastern Aleutian Islands, Alaska. Sixty percent more fish and cephalopod prey were identified by morphological analyses of hard parts compared with DNA analysis of soft parts (hard parts identified higher relative proportions of Ammodytes sp., Cottidae, and certain Gadidae). DNA identified 213 prey occurrences, of which 75 (35%) were undetected by hard parts (mainly Salmonidae, Pleuronectidae, Elasmobranchii, and Cephalopoda), and thereby increased species occurrences by 22% overall and species richness in 44% of cases (when comparing 110 scats that amplified prey DNA). Prey composition was identical within only 20% of scats. Overall, diet composition derived from both identification techniques combined did not differ significantly from hard-part identification alone, suggesting that past scat-based diet studies have not missed major dietary components. However, significant differences in relative diet contributions across scats (as identified using the two techniques separately) reflect passage rate differences between hard and soft digesta material and highlight certain hypothesized limitations in conventional morphological-based methods (e.g., differences in resistance to digestion, hard part regurgitation, partial and secondary prey consumption), as well as potential technical issues (e.g., resolution of primer efficiency and sensitivity and scat subsampling protocols). DNA analysis of salmon occurrence (from scat soft-part matrix and 238 archived salmon hard parts) provided species-level taxonomic resolution that could not be obtained by morphological identification and showed that Steller sea lions were primarily consuming pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon. Notably, DNA from Atlantic salmon (Salmo salar) that likely originated from a distant fish farm was also detected in two scats from one site in the eastern Aleutian Islands. Overall, molecular techniques are valuable for identifying prey in the fecal remains of marine predators. Combining DNA and hard-part identification will effectively alleviate certain predicted biases and will ultimately enhance measures of diet richness, fisheries interactions (especially salmon-related ones), and the ecological role of pinnipeds and other marine predators, to the benefit of marine wildlife conservationists and fisheries managers.
Disproportionate single-species contribution to canopy-soil nutrient flux in an Amazonian rainforest
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Rainfall, throughfall and stemflow were monitored on an event basis in an undisturbed open tropical rainforest with a large number of palm trees located in the southwestern Amazon basin of Brazil. Stemflow samples were collected from 24 trees with a diameter at breast height (DBH) > 5 cm, as well as eight young and four full-grown babassu palms (Attalea speciosa Mart.) for 5 weeks during the peak of the wet season. We calculated rainfall, throughfall and stemflow concentrations and fluxes of Na+, K+, Ca2+, Mg2+,, Cl-, SO42-, NO3- and H+ and stemflow volume-weighted mean concentrations and fluxes for three size classes of broadleaf trees and three size classes of palms. The concentrations of most solutes were higher in stemflow than in rainfall and increased with increasing tree and palm size. Concentration enrichments from rainfall to stemflow and throughfall were particularly high (81-fold) for NO3-. Stemflow fluxes of NO3- and H+ exceeded throughfall fluxes but stemflow fluxes of other solutes were less than throughfall fluxes. Stemflow solute fluxes to the forest soil were dominated by fluxes on babassu palms, which represented only 4% of total stem number and 10% of total basal area. For NO3-, stemflow contributed 51% of the total mass of nitrogen delivered to the forest floor (stemflow + throughfall) and represented more than a 2000-fold increase in NO3- flux compared what would have been delivered by rainfall alone on the equivalent area. Because these highly localized fluxes of both water and NO3- persist in time and space, they have the potential to affect patterns of soil moisture, microbial populations and other features of soil biogeochemistry conducive to the creation of hotspots for nitrogen leaching and denitrification, which could amount to an important fraction of total ecosystem fluxes. Because these hotspots occur over very small areas, they have likely gone undetected in previous studies and need to be considered as an important feature of the biogeochemistry of palm-rich tropical forest. (C) 2011 Elsevier B.V. All rights reserved.
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OBJECTIVE: One major problem in counselling couples with a prenatal diagnosis of a correctable fetal anomaly is the ability to exclude associated malformations that may modify the prognosis. Our aim was to assess the precision of fetal sonography in identifying isolated malformations. METHODS: We retrospectively reviewed the prenatal and postnatal records of our center for cases with a prenatal diagnosis of an isolated fetal anomaly in the period 2002-2007. RESULTS: The antenatal diagnosis of an isolated malformation was made in 284 cases. In one of this cases the anomaly disappeared in utero. Of the remaining cases, the prenatal diagnosis was confirmed after birth in 251 (88.7%). In 8 fetuses (7 with a suspected coarctation of the aorta, 1 with ventricular septal defect) the prenatal diagnosis was not confirmed. In 24 fetuses (8.5%) additional malformations were detected at postnatal or post-mortem. In 16 of these cases the anomalies were mild or would not have changed the prognosis. In 8 cases (2.8%) severe anomalies were present (1 hypoplasia of the corpus callosum with ventriculomegaly, 1 tracheal agenesis, 3 cases with multiple anomalies, 1 Opitz Syndrome, 1 with CHARGE Syndrome, 1 COFS Syndrome). Two of these infants died. CONCLUSIONS: the prenatal diagnosis of an isolated fetal anomaly is highly reliable. However, the probability that additional malformations will go undetected albeit small remains tangible. In our experience, it was 2.8%.
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Lesions to the primary geniculo-striate visual pathway cause blindness in the contralesional visual field. Nevertheless, previous studies have suggested that patients with visual field defects may still be able to implicitly process the affective valence of unseen emotional stimuli (affective blindsight) through alternative visual pathways bypassing the striate cortex. These alternative pathways may also allow exploitation of multisensory (audio-visual) integration mechanisms, such that auditory stimulation can enhance visual detection of stimuli which would otherwise be undetected when presented alone (crossmodal blindsight). The present dissertation investigated implicit emotional processing and multisensory integration when conscious visual processing is prevented by real or virtual lesions to the geniculo-striate pathway, in order to further clarify both the nature of these residual processes and the functional aspects of the underlying neural pathways. The present experimental evidence demonstrates that alternative subcortical visual pathways allow implicit processing of the emotional content of facial expressions in the absence of cortical processing. However, this residual ability is limited to fearful expressions. This finding suggests the existence of a subcortical system specialised in detecting danger signals based on coarse visual cues, therefore allowing the early recruitment of flight-or-fight behavioural responses even before conscious and detailed recognition of potential threats can take place. Moreover, the present dissertation extends the knowledge about crossmodal blindsight phenomena by showing that, unlike with visual detection, sound cannot crossmodally enhance visual orientation discrimination in the absence of functional striate cortex. This finding demonstrates, on the one hand, that the striate cortex plays a causative role in crossmodally enhancing visual orientation sensitivity and, on the other hand, that subcortical visual pathways bypassing the striate cortex, despite affording audio-visual integration processes leading to the improvement of simple visual abilities such as detection, cannot mediate multisensory enhancement of more complex visual functions, such as orientation discrimination.
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Das Glaukom ist, nach dem Katarakt, die zweithäufigste Ursache für Erblindungen weltweit mit Milionen von Betroffenen, die von dieser zunächst weitgehend symptomfreien neurodegenerativen Erkrankung heimgesucht werden. Die Möglichkeiten auf dem Feld der Diagnose beschränken sich bislang weitestgehend auf die Messung des Augeninnendrucks und der Beurteilung des Augenhintergrundes durch einen erfahrenen Augenarzt. Eine labordiagnostische Prophylaxe ist bis heute nicht verfügbar, die Zahl unerkannter Erkrankungen dementsprechend hoch. Hierdurch geht wertvolle Zeit verloren, die man für eine effektive Therapie nutzen könnte.rnBezüglich der Pathogenese des Glaukoms geht man heute von mehreren, miteinander wechselwirkenden Pathomechanismen aus, zu denen neben mechanischen Einflüssen durch einen erhöhten IOD auch Hypoxie, verminderte Neutrophinversorgung, Exzitotoxizität, oxidativer Stress und eine Beteiligung autoimmuner Prozesse gezählt werden. Unabhängig vom Pathomechanismus folgt stets die Etablierung umfangreicher degenerativer Prozesse im Sehnervenkopf, den retinalen Ganglienzellen und den Axonen des Sehnerven, die letztlich im irreversiblen Untergang dieser Neuronen münden. Diese pathologischen Prozesse im ZNS hinterlassen auf Proteomebene Spuren, die mithilfe moderner massenspektrometrischer Methoden in Kombination mit multivariaten statistischen Methoden detektierbar und als sogenannte Biomarker-Kandidaten mit definiertem Molekulargewicht darstellbar sind. In dieser Arbeit wurde ein „Workflow“ entwickelt, der es ermöglicht, diese Biomarker-Kandidaten im Blutserum und in der Tränenflüssigkeit in einfachen, reproduzierbaren Schritten zu identifizieren und zu charakterisieren. Abweichend von der etablierten Methotik der Bottom-Up-Proteomics musste hierfür eine Methode entsprechend einer Top-Down-Philosophie entwickelt werden, die es erlaubt, die Spuren des Glaukoms im Proteom zu detektieren und zu charakterisieren.rnDies erfolgte in dieser Arbeit durch sowohl massenspektroskopischen Methoden wie SELDI-TOF® und MALDI-Tof-Tof als auch durch Bead-, Gel- und Flüssigkeits-chromatographisch-basierte Separations und Fraktionierungstechniken.rnDie erfolgreiche Kombination dieser Methoden führte zu Identifikationen einer ganzen Reihe von Biomarker-Kandidaten. Unter den identifizierten Proteinen, die bezüglich ihres korrespondierenden SELDI-Peaks im Massenbereich von Biomarker-Kandidaten liegen, finden sich Zytokine und Effektormoleküle der angeborernen Immunität, stressinduzierbare Kinasen, Faktoren, die zum Schutz der Telomeren dienen, Proliferationsmarker, neuronale Antigene und Transportproteine. Darüber hinaus wurden Komponenten identifiziert, die an der neuronalen Neutrophinversorgung beteiligt sind, neuronale Rezeptoren und Antigene, Komponenten des Komplementsystems und des MHC-I-Komplexes. All diese identifizierten Proteine sind bezüglich ihrer Funktion und möglichen Rolle innerhalb der Pathogenese des Glaukoms detailliert beschrieben und charakterisiert. Dies erlaubt einen umfassenden Einblick in alle Pathomechanismen, denen nach heutigem Kenntnisstand, eine Rolle an der Pathogenese des Glaukoms unterstellt wird.rn
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Late-onset symptoms of urea-cycle disorder may lead to a life-threatening disease which is often undetected. We report the clinical and metabolic manifestations of acute hyperammonemic encephalopathy in a 47-year-old asymptomatic man with ornithine transcarbamylase (OTC) deficiency. The hyperammonemic encephalopathy was unmasked by a high-protein Atkins diet.