952 resultados para Covering maps
Resumo:
We study the growth of Df `` (f(c)) when f is a Fibonacci critical covering map of the circle with negative Schwarzian derivative, degree d >= 2 and critical point c of order l > 1. As an application we prove that f exhibits exponential decay of geometry if and only if l <= 2, and in this case it has an absolutely continuous invariant probability measure, although not satisfying the so-called Collet-Eckmann condition. (C) 2009 Elsevier Masson SAS. All rights reserved.
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Nucleoside hydrolases (NHs) show homology among parasite protozoa, fungi and bacteria. They are vital protagonists in the establishment of early infection and, therefore, are excellent candidates for the pathogen recognition by adaptive immune responses. Immune protection against NHs would prevent disease at the early infection of several pathogens. We have identified the domain of the NH of L. donovani (NH36) responsible for its immunogenicity and protective efficacy against murine visceral leishmaniasis (VL). Using recombinant generated peptides covering the whole NH36 sequence and saponin we demonstrate that protection against L. chagasi is related to its C-terminal domain (amino-acids 199-314) and is mediated mainly by a CD4+ T cell driven response with a lower contribution of CD8+ T cells. Immunization with this peptide exceeds in 36.73 +/- 12.33% the protective response induced by the cognate NH36 protein. Increases in IgM, IgG2a, IgG1 and IgG2b antibodies, CD4+ T cell proportions, IFN-gamma secretion, ratios of IFN-gamma/IL-10 producing CD4+ and CD8+ T cells and percents of antibody binding inhibition by synthetic predicted epitopes were detected in F3 vaccinated mice. The increases in DTH and in ratios of TNF alpha/IL-10 CD4+ producing cells were however the strong correlates of protection which was confirmed by in vivo depletion with monoclonal antibodies, algorithm predicted CD4 and CD8 epitopes and a pronounced decrease in parasite load (90.5-88.23%; p = 0.011) that was long-lasting. No decrease in parasite load was detected after vaccination with the N-domain of NH36, in spite of the induction of IFN-gamma/IL-10 expression by CD4+ T cells after challenge. Both peptides reduced the size of footpad lesions, but only the C-domain reduced the parasite load of mice challenged with L. amazonensis. The identification of the target of the immune response to NH36 represents a basis for the rationale development of a bivalent vaccine against leishmaniasis and for multivalent vaccines against NHs-dependent pathogens.
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A study on the spatial distribution of the major weeds in maize was carried out in 2007 and 2008 in a field located in Golegã (Ribatejo region, Portugal). The geo-referenced sampling focused on 150 points of a 10 x 10 m mesh covering an area of 1.5 ha, before herbicide application and before harvest. In the first year, 40 species (21 botanical families) were identified at seedling stage and only 22 during the last observation. The difference in species richness can be attributed to maize monoculture favouring reduction in species number. Three of the most representative species were selected for the spatial distribution analysis: Solanum nigrum, Chenopodium album and Echinochloa crus-galli. The three species showed an aggregated spatial pattern and spatial stability over both years, although the herbicide effect is evident in the distribution of some of them in the space. These results could be taken into account when planning site-specific treatments in maize.
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We have analyzed XMM-Newton archive data for five clusters of galaxies (redshifts 0.223-0.313) covering a wide range of dynamical states, from relaxed objects to clusters undergoing several mergers. We present here temperature maps of the X-ray gas together with a preliminary interpretation of the formation history of these clusters. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
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We propose an alternative formalism to simulate cosmic microwave background (CMB) temperature maps in Lambda CDM universes with nontrivial spatial topologies. This formalism avoids the need to explicitly compute the eigenmodes of the Laplacian operator in the spatial sections. Instead, the covariance matrix of the coefficients of the spherical harmonic decomposition of the temperature anisotropies is expressed in terms of the elements of the covering group of the space. We obtain a decomposition of the correlation matrix that isolates the topological contribution to the CMB temperature anisotropies out of the simply connected contribution. A further decomposition of the topological signature of the correlation matrix for an arbitrary topology allows us to compute it in terms of correlation matrices corresponding to simpler topologies, for which closed quadrature formulas might be derived. We also use this decomposition to show that CMB temperature maps of (not too large) multiply connected universes must show patterns of alignment, and propose a method to look for these patterns, thus opening the door to the development of new methods for detecting the topology of our Universe even when the injectivity radius of space is slightly larger than the radius of the last scattering surface. We illustrate all these features with the simplest examples, those of flat homogeneous manifolds, i.e., tori, with special attention given to the cylinder, i.e., T-1 topology.
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Map landscape-based segmentation of the sequences of momentary potential distribution maps (42-channel recordings) into brain microstates during spontaneous brain activity was used to study brain electric field spatial effects of single doses of piracetam (2.9, 4.8, and 9.6 g Nootropil® UCB and placebo) in a double-blind study of five normal young volunteers. Four 15-second epochs were analyzed from each subject and drug condition. The most prominent class of microstates (covering 49% of the time) consisted of potential maps with a generally anterior-posterior field orientation. The map orientation of this microstate class showed an increasing clockwise deviation from the placebo condition with increasing drug doses (Fisher's probability product, p < 0.014). The results of this study suggest the use of microstate segmentation analysis for the assessment of central effects of medication in spontaneous multichannel electroencephalographic data, as a complementary approach to frequency-domain analysis.
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From 1978 to 1981, intensive sedimentological investigations were carried out on the Northfrisian intertidal shoals between the small island of Gröde and Nordstrand lsland as a part of an interdisciplinary research projekt. The objective of this sedimentological study was to reveal long and short term tendencies in sedimentation and erosion in the environment. The presented study mainly concentrated on surface mapping in the tidal flats which based on more than 5000 sediment samples. The relative amounts of the grain-size fractions <0.063 mm and >0.125 mm are presented on maps. Predominant sediment typs are well sorted fine sands ("Wattsand") and muddy sands ("Schlicksand"), pure muds covering only small areas. The fine-grained deposits are either found in the lee-side of an island in elongated bays having a low waterdepth during high tide near the shore or near exposed "Klei" outcrops as well as sporadically on the edge of tidal rills. Together with standardized fields observations of biological and physical properties, the maps indicate a slight erosive tendency in large sections of the investigated area.
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Reconstructing past landscapes from historical maps requires quantifying the accuracy and completeness of these sources. The accuracy and completeness of two historical maps of the same period covering the same area in Israel were examined: the 1:63,360 British Palestine Exploration Fund map (1871-1877) and the 1:100,000 French Levés en Galilée (LG) map (1870). These maps cover the mountainous area of the Galilee (northern Israel), a region with significant natural and topographical diversity, and a long history of human presence. Land-cover features from both maps, as well as the contours drawn on the LG map, were digitized. The overall correspondence between land-cover features shown on both maps was 59% and we found that the geo-referencing method employed (transformation type and source of control points) did not significantly affect these correspondence measures. Both maps show that in the 1870s, 35% of the Galilee was covered by Mediterranean maquis, with less than 8% of the area used for permanent agricultural cropland (e.g., plantations). This article presents how the reliability of the maps was assessed by using two spatial historical sources, and how land-cover classes that were mapped with lower certainty and completeness are identified. Some of the causes that led to observed differences between the maps, including mapping scale, time of year, and the interests of the surveyors, are also identified.
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A shallow gas depth-contour map covering the Skagerrak-western Baltic Sea region has been constructed using a relatively dense grid of existing shallow seismic lines. The digital map is stored as an ESRI shape file in order to facilitate comparison with other data from the region. Free gas usually occurs in mud and sandy mud but is observed only when sediment thickness exceeds a certain threshold value, depending on the water depth of the area in question. Gassy sediments exist at all water depths from approx. 20 m in the coastal waters of the Kattegat to 360 m in the Skagerrak. In spite of the large difference in water depths, the depth of free gas below seabed varies only little within the region, indicating a relatively fast movement of methane in the gas phase towards the seabed compared to the rate of diffusion of dissolved methane. Seeps of old microbial methane occur in the northern Kattegat where a relatively thin cover of sandy sediments exists over shallow, glacially deformed Pleistocene marine sediments. Previous estimates of total methane escape from the area may be correct but the extrapolation of local methane seepage rate data to much larger areas on the continental shelf is probably not justified. Preliminary data on porewater chemistry were compared with the free gas depth contours in the Aarhus Bay area, which occasionally suffers from oxygen deficiency, in order to examine if acoustic gas mapping may be used for monitoring the condition of the bay.
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We describe an integrated approach to large-scale physical mapping using an Alu-PCR hybridization screening strategy in conjunction with direct PCR-based screening to construct a continuous yeast artificial chromosome map covering >20 mb in human chromosome 3, bands p14-p21, composed of 205 loci, connected by 480 yeast artificial chromosomes, with average interlocus distance of approximately equal to 100 kb. We observe an inverse distribution of Alu-PCR and (CA)n markers. These results suggest that the two screening methods may be complementary and demonstrate the utility of Alu-PCR hybridization screening in the closure of high-resolution human physical maps.
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Coral reef maps at various spatial scales and extents are needed for mapping, monitoring, modelling, and management of these environments. High spatial resolution satellite imagery, pixel <10 m, integrated with field survey data and processed with various mapping approaches, can provide these maps. These approaches have been accurately applied to single reefs (10-100 km**2), covering one high spatial resolution scene from which a single thematic layer (e.g. benthic community) is mapped. This article demonstrates how a hierarchical mapping approach can be applied to coral reefs from individual reef to reef-system scales (10-1000 km**2) using object-based image classification of high spatial resolution images guided by ecological and geomorphological principles. The approach is demonstrated for three individual reefs (10-35 km**2) in Australia, Fiji, and Palau; and for three complex reef systems (300-600 km**2) one in the Solomon Islands and two in Fiji. Archived high spatial resolution images were pre-processed and mosaics were created for the reef systems. Georeferenced benthic photo transect surveys were used to acquire cover information. Field and image data were integrated using an object-based image analysis approach that resulted in a hierarchically structured classification. Objects were assigned class labels based on the dominant benthic cover type, or location-relevant ecological and geomorphological principles, or a combination thereof. This generated a hierarchical sequence of reef maps with an increasing complexity in benthic thematic information that included: 'reef', 'reef type', 'geomorphic zone', and 'benthic community'. The overall accuracy of the 'geomorphic zone' classification for each of the six study sites was 76-82% using 6-10 mapping categories. For 'benthic community' classification, the overall accuracy was 52-75% with individual reefs having 14-17 categories and reef systems 20-30 categories. We show that an object-based classification of high spatial resolution imagery, guided by field data and ecological and geomorphological principles, can produce consistent, accurate benthic maps at four hierarchical spatial scales for coral reefs of various sizes and complexities.
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This study aimed to characterize which regulatory logics (other than government regulation) result in healthcare output, using a two-stage qualitative study in two municipalities in the ABCD Paulista region in São Paulo State, Brazil. The first stage included interviews with strategic actors (managers and policymakers) and key health professionals. The second phase collected life histories from 18 individuals with high health-services utilization rates. An analysis of the researchers' involvement in the field allowed a better understanding of the narratives. Four regulatory systems were characterized (governmental, professional, clientelistic, and lay), indicating that regulation is a field in constant dispute, a social production. Users' action produces healthcare maps that reveal the existence of other possible health system arrangements, calling on us to test shared management of healthcare between health teams and users as a promising path to the urgent need to reinvent health.
Resumo:
PURPOSE: The main goal of this study was to develop and compare two different techniques for classification of specific types of corneal shapes when Zernike coefficients are used as inputs. A feed-forward artificial Neural Network (NN) and discriminant analysis (DA) techniques were used. METHODS: The inputs both for the NN and DA were the first 15 standard Zernike coefficients for 80 previously classified corneal elevation data files from an Eyesys System 2000 Videokeratograph (VK), installed at the Departamento de Oftalmologia of the Escola Paulista de Medicina, São Paulo. The NN had 5 output neurons which were associated with 5 typical corneal shapes: keratoconus, with-the-rule astigmatism, against-the-rule astigmatism, "regular" or "normal" shape and post-PRK. RESULTS: The NN and DA responses were statistically analyzed in terms of precision ([true positive+true negative]/total number of cases). Mean overall results for all cases for the NN and DA techniques were, respectively, 94% and 84.8%. CONCLUSION: Although we used a relatively small database, results obtained in the present study indicate that Zernike polynomials as descriptors of corneal shape may be a reliable parameter as input data for diagnostic automation of VK maps, using either NN or DA.
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Apesar do reconhecimento da importância dos conhecimentos geográficos e do uso das ferramentas de análise espacial nos estudos da saúde coletiva, esse é um campo ainda pouco explorado pelos pesquisadores brasileiros. Em levantamento realizado nas principais revistas científicas que veiculam os resultados de pesquisa em saúde do trabalhador, verificou-se o grande predomínio do uso de tabelas e gráficos como meio de organizar e apresentar os resultados obtidos, e o número reduzido de mapas. Para isso foram examinados todos os artigos publicados em quatro periódicos (Revista de Saúde Pública, Cadernos de Saúde Pública, Revista Saúde e Sociedade e Revista Brasileira de Epidemiologia) no período de 1967 a 2009. Uma vez analisado o conjunto de artigos selecionados no estudo, aqueles que utilizaram representações cartográficas receberam atenção especial. Verificou-se que, embora ainda pouco utilizadas, as ferramentas do geoprocessamento e da geoestatística com suporte em SIG abrem um campo de novas possibilidades no uso da cartografia temática em saúde do trabalhador no Brasil. Contudo, recomenda-se para os editores das revistas científicas o detalhamento de normas técnicas para publicação de figuras cartográficas, assim como a elaboração de pareceres específicos que possam auxiliar os autores em vista das modificações necessárias para a melhoria da qualidade da comunicação visual de mapas e da correlação espacial por meio do tratamento cartográfico.
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Some factors complicate comparisons between linkage maps from different studies. This problem can be resolved if measures of precision, such as confidence intervals and frequency distributions, are associated with markers. We examined the precision of distances and ordering of microsatellite markers in the consensus linkage maps of chromosomes 1, 3 and 4 from two F 2 reciprocal Brazilian chicken populations, using bootstrap sampling. Single and consensus maps were constructed. The consensus map was compared with the International Consensus Linkage Map and with the whole genome sequence. Some loci showed segregation distortion and missing data, but this did not affect the analyses negatively. Several inversions and position shifts were detected, based on 95% confidence intervals and frequency distributions of loci. Some discrepancies in distances between loci and in ordering were due to chance, whereas others could be attributed to other effects, including reciprocal crosses, sampling error of the founder animals from the two populations, F(2) population structure, number of and distance between microsatellite markers, number of informative meioses, loci segregation patterns, and sex. In the Brazilian consensus GGA1, locus LEI1038 was in a position closer to the true genome sequence than in the International Consensus Map, whereas for GGA3 and GGA4, no such differences were found. Extending these analyses to the remaining chromosomes should facilitate comparisons and the integration of several available genetic maps, allowing meta-analyses for map construction and quantitative trait loci (QTL) mapping. The precision of the estimates of QTL positions and their effects would be increased with such information.