Discriminação de áreas de espesso regolito do leste do Estado do Amazonas usando estatística multivariada, algoritmo hiperespectral e modelagem de dados espaciais

Áreas com espessos regolitos estão amplamente distribuídas na região amazônica. Nas últimas décadas, as pesquisas sobre geologia de regolitos no Brasil têm se concentrado, principalmente, nos aspectos geoquímicos e mineralógicos e seus possíveis usos para a exploração de recursos minerais. Embora a utilização da aerogeofísica e de métodos de integração de dados tenham se ampliado na avaliação de recursos minerais, a aplicação em terrenos regolíticos ainda é recente. O objetivo deste artigo é mostrar o potencial de uma abordagem sistemática, incluindo o uso de aerogamaespectrometria regional, modelo digital de elevação e processamento digital de imagens, para a identificação de áreas de espesso regolito com potencial interesse econômico em uma área pouco explorada da porção leste do Estado do Amazonas. A aplicação de técnicas de estatística multivariada (Análise por Principais Componentes e K-médias) em dados aerogamaespectrométricos permitiu a individualização de regolitos frente às respostas provenientes de unidades geológicas da região. Como guias para a identificação de áreas de espesso regolito, os seguintes padrões foram observados: baixos valores de K (facilmente lixiviado durante o intemperismo) e da razão K/eU; altos valores de eTh, da razão eTh/K e médios de eU, além de maiores altitudes (platôs). Aplicou-se o algoritmo originalmente desenvolvido para o sensoriamento remoto hiperespectral, denominado Spectral Angle Mapper (SAM), e técnicas de modelagens espaciais (lógicas booleana e fuzzy) para a produção de mapas de favorabilidade para a ocorrência de espesso regolito que foram comparados com mapa geológico em escala 1:250.000. As relações quantitativas entre conjuntos de dados geofísicos e altimétricos mostraram grande capacidade para o link entre interpretações geológicas e geofísicas, indicando-se áreas potenciais para direcionar a prospecção mineral na área de estudo.Areas with deep regolith profiles are widely distributed in the Amazonian region. Research on regolith geology in Brazil has concentrated, mainly, in geochemical and mineralogical aspects and where possible utilizing these in exploration. Although airborne geophysics and spatial data integration methods are being used increasingly for mineral resource assessments, the application in regolith-dominated terrains is new. The objective of this paper is to show the potential of a systematic approach, including the use of regional gamma-ray spectrometry, digital elevation model and image digital processing techniques for the identification of deep regolith areas characterized by potential economic interest in less well explored region of the eastern portion of Amazonas State. The application of multivariate statistics techniques (Principal Components Analysis and K-means) in airborne gamma-ray data allows the individualization of regoliths in comparison to the geologic units of this region. How exploratory guide, the following patterns were observed: low values of K (easily lixivied during the weathering) and K/eU ratio; high values of eTh, eTh/K ration and medium values of eU, besides the higher altitude (plateau). Based on these images, the hyperspectral algorithm named Spectral Angle Mapper (SAM) and the boolean and fuzzy logic spatial modeling techniques were applied to produce regolith potential maps that were compared with previous geological data in 1:250.000 scale. The quantitative relationships between geophysical and altimetric datasets have shown great capability for linking geological and geophysical interpretations, indicating potential areas that can direct new ways for mineral prospecting at the study area

New method to characterize a machining system: application in turning

Many studies simulates the machining process by using a single degree of freedom spring-mass sytem to model the tool stiffness, or the workpiece stiffness, or the unit tool-workpiece stiffness in modelings 2D. Others impose the tool action, or use more or less complex modelings of the efforts applied by the tool taking account the tool geometry. Thus, all these models remain two-dimensional or sometimes partially three-dimensional. This paper aims at developing an experimental method allowing to determine accurately the real three-dimensional behaviour of a machining system (machine tool, cutting tool, tool-holder and associated system of force metrology six-component dynamometer). In the work-space model of machining, a new experimental procedure is implemented to determine the machining system elastic behaviour. An experimental study of machining system is presented. We propose a machining system static characterization. A decomposition in two distinct blocks of the system "Workpiece-Tool-Machine" is realized. The block Tool and the block Workpiece are studied and characterized separately by matrix stiffness and displacement (three translations and three rotations). The Castigliano's theory allows us to calculate the total stiffness matrix and the total displacement matrix. A stiffness center point and a plan of tool tip static displacement are presented in agreement with the turning machining dynamic model and especially during the self induced vibration. These results are necessary to have a good three-dimensional machining system dynamic characterization

Granzyme B Cleaves Decorin, Biglycan and Soluble Betaglycan, Releasing Active Transforming Growth Factor-β1

Objective: Granzyme B (GrB) is a pro-apoptotic serine protease that contributes to immune-mediated target cell apoptosis. However, during inflammation, GrB accumulates in the extracellular space, retains its activity, and is capable of cleaving extracellular matrix (ECM) proteins. Recent studies have implicated a pathogenic extracellular role for GrB in cardiovascular disease, yet the pathophysiological consequences of extracellular GrB activity remain largely unknown. The objective of this study was to identify proteoglycan (PG) substrates of GrB and examine the ability of GrB to release PG-sequestered TGF-b1 into the extracellular milieu. Methods/Results: Three extracellular GrB PG substrates were identified; decorin, biglycan and betaglycan. As all of these PGs sequester active TGF-b1, cytokine release assays were conducted to establish if GrB-mediated PG cleavage induced TGF-b1 release. Our data confirmed that GrB liberated TGF-b1 from all three substrates as well as from endogenous ECM and this process was inhibited by the GrB inhibitor 3,4-dichloroisocoumarin. The released TGF-b1 retained its activity as indicated by the induction of SMAD-3 phosphorylation in human coronary artery smooth muscle cells. Conclusion: In addition to contributing to ECM degradation and the loss of tissue structural integrity in vivo, increase

Psychopathology predicts the outcome of medial branch blocks with corticosteroid for chronic axial low back or cervical pain: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Comorbid psychopathology is an important predictor of poor outcome for many types of treatments for back or neck pain. But it is unknown if this applies to the results of medial branch blocks (MBBs) for chronic low back or neck pain, which involves injecting the medial branch of the dorsal ramus nerves that innervate the facet joints. The objective of this study was to determine whether high levels of psychopathology are predictive of pain relief after MBB injections in the lumbar or cervical spine.</p> <p>Methods</p> <p>This was a prospective cohort study. Consecutive patients in a pain medicine practice undergoing MBBs of the lumbar or cervical facets with corticosteroids were recruited to participate. Subjects were selected for a MBB based on operationalized selection criteria and the procedure was performed in a standardized manner. Subjects completed the Brief Pain Inventory (BPI) and the Hospital Anxiety and Depression Scale (HADS) just prior to the procedure and at one-month follow up. Scores on the HADS classified the subjects into three groups based on psychiatric symptoms, which formed the primary predictor variable: <it>Low</it>, <it>Moderate</it>, or <it>High </it>levels of psychopathology. The primary outcome measure was the percent improvement in average daily pain rating one-month following an injection. Analysis of variance and chi-square were used to analyze the analgesia and functional rating differences between groups, and to perform a responder analysis.</p> <p>Results</p> <p>Eighty six (86) subjects completed the study. The <it>Low </it>psychopathology group (n = 37) reported a mean of 23% improvement in pain at one-month while the <it>High </it>psychopathology group (n = 29) reported a mean worsening of -5.8% in pain (p < .001). Forty five percent (45%) of the <it>Low </it>group had at least 30% improvement in pain versus 10% in the <it>High </it>group (p < .001). Using an analysis of covariance, no baseline demographic, social, or medical variables were significant predictors of pain improvement, nor did they mitigate the effect of psychopathology on the outcome.</p> <p>Conclusion</p> <p>Psychiatric comorbidity is associated with diminished pain relief after a MBB injection performed with steroid at one-month follow-up. These findings illustrate the importance of assessing comorbid psychopathology as part of a spine care evaluation.</p

Aging Alters Functionally Human Dermal Papillary Fibroblasts but Not Reticular Fibroblasts: A New View of Skin Morphogenesis and Aging

Understanding the contribution of the dermis in skin aging is a key question, since this tissue is particularly important for skin integrity, and because its properties can affect the epidermis. Characteristics of matched pairs of dermal papillary and reticular fibroblasts (Fp and Fr) were investigated throughout aging, comparing morphology, secretion of cytokines, MMPs/TIMPs, growth potential, and interaction with epidermal keratinocytes. We observed that Fp populations were characterized by a higher proportion of small cells with low granularity and a higher growth potential than Fr populations. However, these differences became less marked with increasing age of donors. Aging was also associated with changes in the secretion activity of both Fp and Fr. Using a reconstructed skin model, we evidenced that Fp and Fr cells do not possess equivalent capacities to sustain keratinopoiesis. Comparing Fp and Fr from young donors, we noticed that dermal equivalents containing Fp were more potent to promote epidermal morphogenesis than those containing Fr. These data emphasize the complexity of dermal fibroblast biology and document the specific functional properties of Fp and Fr. Our results suggest a new model of skin aging in which marked alterations of Fp may affect the histological characteristics of skin

Histological and transcriptome-wide level characteristics of fetal myofiber hyperplasia during the second half of gestation in Texel and Ujumqin sheep

<p>Abstract</p> <p>Background</p> <p>Whether myofibers increase with a pulsed-wave mode at particular developmental stages or whether they augment evenly across developmental stages in large mammals is unclear. Additionally, the molecular mechanisms of myostatin in myofiber hyperplasia at the fetal stage in sheep remain unknown. Using the first specialized transcriptome-wide sheep oligo DNA microarray and histological methods, we investigated the gene expression profile and histological characteristics of developing fetal ovine longissimus muscle in Texel sheep (high muscle and low fat), as a myostatin model of natural mutation, and Ujumqin sheep (low muscle and high fat). Fetal skeletal muscles were sampled at 70, 85, 100, 120, and 135 d of gestation.</p> <p>Results</p> <p>Myofiber number increased sharply with a pulsed-wave mode at certain developmental stages but was not augmented evenly across developmental stages in fetal sheep. The surges in myofiber hyperplasia occurred at 85 and 120 d in Texel sheep, whereas a unique proliferative surge appeared at 100 d in Ujumqin sheep. Analysis of the microarray demonstrated that immune and hematological systems' development and function, lipid metabolism, and cell communication were the biological functions that were most differentially expressed between Texel and Ujumqin sheep during muscle development. Pathways associated with myogenesis and the proliferation of myoblasts, such as calcium signaling, chemokine (C-X-C motif) receptor 4 signaling, and vascular endothelial growth factor signaling, were affected significantly at specific fetal stages, which underpinned fetal myofiber hyperplasia and postnatal muscle hypertrophy. Moreover, we identified some differentially expressed genes between the two breeds that could be potential myostatin targets for further investigation.</p> <p>Conclusions</p> <p>Proliferation of myofibers proceeded in a pulsed-wave mode at particular fetal stages in the sheep. The myostatin mutation changed the gene expression pattern in skeletal muscle at a transcriptome-wide level, resulting in variation in myofiber phenotype between Texel and Ujumqin sheep during the second half of gestation. Our findings provide a novel and dynamic description of the effect of myostatin on skeletal muscle development, which contributes to understanding the biology of muscle development in large mammals.</p

The Secreted Metalloprotease ADAMTS20 Is Required for Melanoblast Survival

ADAMTS20 (A disintegrin-like and metalloprotease domain with thrombospondin type-1 motifs) is a member of a family of secreted metalloproteases that can process a variety of extracellular matrix (ECM) components and secreted molecules. Adamts20 mutations in belted (bt) mice cause white spotting of the dorsal and ventral torso, indicative of defective neural crest (NC)-derived melanoblast development. The expression pattern of Adamts20 in dermal mesenchymal cells adjacent to migrating melanoblasts led us to initially propose that Adamts20 regulated melanoblast migration. However, using a Dct-LacZ transgene to track melanoblast development, we determined that melanoblasts were distributed normally in whole mount E12.5 bt/bt embryos, but were specifically reduced in the trunk of E13.5 bt/bt embryos due to a seven-fold higher rate of apoptosis. The melanoblast defect was exacerbated in newborn skin and embryos from bt/bt animals that were also haploinsufficient for Adamts9, a close homolog of Adamts20, indicating that these metalloproteases functionally overlap in melanoblast development. We identified two potential mechanisms by which Adamts20 may regulate melanoblast survival. First, skin explant cultures demonstrated that Adamts20 was required for melanoblasts to respond to soluble Kit ligand (sKitl). In support of this requirement, bt/bt;Kittm1Alf/+ and bt/bt;KitlSl/+ mice exhibited synergistically increased spotting. Second, ADAMTS20 cleaved the aggregating proteoglycan versican in vitro and was necessary for versican processing in vivo, raising the possibility that versican can participate in melanoblast development. These findings reveal previously unrecognized roles for Adamts proteases in cell survival and in mediating Kit signaling during melanoblast colonization of the skin. Our results have implications not only for understanding mechanisms of NC-derived melanoblast development but also provide insights on novel biological functions of secreted metalloproteases

Análise prospectiva para ouro nas regiões Ouro Roxo-Cantagalo e Chico Torres, Província Mineral do Tapajós

Modelagem espacial (lógica fuzzy) foi empregada para a previsão de áreas potenciais à exploração aurífera na Província Mineral do Tapajós (PMT -Amazônia brasileira), especificamente nas regiões aqui denominadas Ouro Roxo-Cantagalo e Chico Torres. Os dados utilizados compreendem os aerogeofísicos e de imagens SAR-R99B. O processamento dos dados aerogeofísicos permitiu a geração de imagens como as do potássio anômalo, parâmetro F, razões e normalização de radioelementos e a amplitude do sinal analítico do campo magnético anômalo, enquanto que imagens SAR foram empregadas para a etapa de fotointerpretação. A partir da geração de modelos hipotéticos para mineralizações de ouro nas regiões das zonas de cisalhamento Ouro Roxo-Cantagalo e Chico Torres, imagens geofísicas e interpretações, quando convenientes, foram selecionadas para a geração de modelos prospectivos por meio da lógica fuzzy, enquanto que as ocorrências de ouro já conhecidas foram usadas para avaliar a qualidade dos resultados modelados. As principais contribuições desta pesquisa incluem a observação de assinaturas gamaespectrométricas potenciais, um refinamento interpretativo dos dados digitais e melhoramento de informações apresentadas nos mapas geológicos atuais. Os resultados das modelagens prospectivas para as regiões Ouro Roxo-Cantagalo e Chico Torres a partir da lógica fuzzy exemplificam a geração de modelos exploratórios regionais para a cartografia e seleção de áreas com potencial para mineralizações de ouro, podendo esta metodologia ser estendida a outras regiões da PMT, utilizando-se os dados aerogeofísicos atualmente disponíveis pelo Serviço Geológico do Brasil e as imagens SAR do Centro Técnico Operacional do Sistema de Proteção da Amazônia (CENSIPAM).Spatial modeling (fuzzy logic) was used to predict key areas for gold exploration in the Tapajós Mineral Province (Brazilian Amazon), specifically in the regions here named Ouro Roxo-Cantagalo and Chico Torres. The data used were regional airborne geophysical and SAR-R99B data. The airborne geophysical data processing allowed the generation of evidence layers for modeling approaches. The best evidences in current models were anomalous potassium, F parameter, radioelement ratios, radioelement normalization, and amplitude of the analytical signal of the magnetic anomalous field. The SAR images were used in the photointerpretation stage. In the case of regions of the Ouro Roxo-Cantagalo and Chico Torres shear zones, geophysical images and interpretations (when necessary) were used to application of fuzzy logic, and the gold locations were used to evaluate the quality of the modeling results. The main contributions of this research include the observation of potential gamma-ray spectrometry signatures, the refining interpretation of the digital data, and improving the information of the current geological maps. The prospective Ouro Roxo-Cantagalo and Chico Torres modeling results using the conceptual fuzzy logic method exemplify the generation of regional exploration models for the cartography and selection of gold potential areas. This methodology can be extended to others regions of the Tapajós Mineral Province using airborne geophysical data current available by CPRM and the SAR images of the Centro Técnico Operacional do Sistema de Proteção da Amazônia (CENSIPAM)