936 resultados para Two Degrees Of Freedom
Resumo:
Pulmonary fat embolism (PFE) is a common complication of blunt force traumas with bone fractures. Severe forms cause impedance to right ventricular (RV) ejection, with eventual right heart ischaemia and failure. In a prospective study, we have investigated 220 consecutive autopsy cases (73 females, 147 males, mean age 52.1 years, min 14 years, max 91 years). PFE was detected in 52 cases that were divided into three groups according to the degree of PFE (1-3). A fourth group of cases of violent death without PFE was used for comparison. In each case, histology (H&E, Masson) and immunohistochemistry (fibronectin and C5b-9) were performed on six cardiac samples (anterior, lateral and posterior wall of both ventricles). The degree of cardiac damage was registered in each sample and the mean degree of damage was calculated in each case at the RV and left ventricle (LV). Moreover, a parameter ∆ that is the difference between the mean damage at the RV and the LV was calculated in each case. The results were compared within each group and between the groups. In the present study, we could not detect prevalent RV damage in cases of high degree PFE as we did in our previous investigation. In the group PFE3 the difference of the degree of damage between the RV and LV was higher than the one observed in the groups PFE0-2 with the antibody anti-fibronectin. Prevalent right ventricular stress in cases of severe PFE may explain this observation.
Resumo:
Clear cell papillary renal cell carcinoma (ccpRCC) and renal angiomyoadenomatous tumor (RAT) share morphologic similarities with clear cell (ccRCC) and papillary RCC (pRCC). It is a matter of controversy whether their morphologic, immunophenotypic, and molecular features allow the definition of a separate renal carcinoma entity. The aim of our project was to investigate specific renal immunohistochemical biomarkers involved in the hypoxia-inducible factor pathway and mutations in the VHL gene to clarify the relationship between ccpRCC and RAT. We investigated 28 ccpRCC and 9 RAT samples by immunohistochemistry using 25 markers. VHL gene mutations and allele losses were investigated by Sanger sequencing and fluorescence in situ hybridization. Clinical follow-up data were obtained for a subset of the patients. No tumor recurrence or tumor-related death was observed in any of the patients. Immunohistochemistry and molecular analyses led to the reclassification of 3 tumors as ccRCC and TFE3 translocation carcinomas. The immunohistochemical profile of ccpRCC and RAT samples was very similar but not identical, differing from both ccRCC and pRCC. Especially, the parafibromin and hKIM-1 expression exhibited differences in ccpRCC/RAT compared with ccRCC and pRCC. Genetic analysis revealed VHL mutations in 2/27 (7%) and 1/7 (14%) ccpRCC and RAT samples, respectively. Fluorescence in situ hybridization analysis disclosed a 3p loss in 2/20 (10%) ccpRCC samples. ccpRCC and RAT have a specific morphologic and immunohistochemical profile, but they share similarities with the more aggressive renal tumors. On the basis of our results, we regard ccpRCC/RAT as a distinct entity of RCCs.
Resumo:
Chromosome studies were performed in two varieties of Mangifera indica L. (mango), 'IAC-140 Espadona' and in its progenitor 'Espada Stahl'. Both varieties showed 2n=40 chromosomes though the karyotype formulae were 8m + 10sm + 2sm s for 'Stahl' and 7m + 11sm + 2sm s for 'IAC-140'. The varieties showed moderate karyotype asymmetry which was estimated according to four different indices. Both varieties exhibited three chromosome pairs with silver impregnation after NOR-banding. The number of nucleoli within interphase cells varied from one, the commonest, to eight. The nucleolus persistent phenomenon was observed in more than 22% of metaphase cells of both varieties, seeing that in 'Stahl', up to two nucleoli were evidenced. This variety also showed one nucleolus in several anaphase cells. The studies were suitable for evidencing diversity at chromosomal level between these two varieties.
Resumo:
By means of computer simulations and solution of the equations of the mode coupling theory (MCT),we investigate the role of the intramolecular barriers on several dynamic aspects of nonentangled polymers. The investigated dynamic range extends from the caging regime characteristic of glass-formers to the relaxation of the chain Rouse modes. We review our recent work on this question,provide new results, and critically discuss the limitations of the theory. Solutions of the MCT for the structural relaxation reproduce qualitative trends of simulations for weak and moderate barriers. However, a progressive discrepancy is revealed as the limit of stiff chains is approached. This dis-agreement does not seem related with dynamic heterogeneities, which indeed are not enhanced by increasing barrier strength. It is not connected either with the breakdown of the convolution approximation for three-point static correlations, which retains its validity for stiff chains. These findings suggest the need of an improvement of the MCT equations for polymer melts. Concerning the relaxation of the chain degrees of freedom, MCT provides a microscopic basis for time scales from chain reorientation down to the caging regime. It rationalizes, from first principles, the observed deviations from the Rouse model on increasing the barrier strength. These include anomalous scaling of relaxation times, long-time plateaux, and nonmonotonous wavelength dependence of the mode correlators.
Resumo:
Electrical resistivity tomography (ERT) is a well-established method for geophysical characterization and has shown potential for monitoring geologic CO2 sequestration, due to its sensitivity to electrical resistivity contrasts generated by liquid/gas saturation variability. In contrast to deterministic inversion approaches, probabilistic inversion provides the full posterior probability density function of the saturation field and accounts for the uncertainties inherent in the petrophysical parameters relating the resistivity to saturation. In this study, the data are from benchtop ERT experiments conducted during gas injection into a quasi-2D brine-saturated sand chamber with a packing that mimics a simple anticlinal geological reservoir. The saturation fields are estimated by Markov chain Monte Carlo inversion of the measured data and compared to independent saturation measurements from light transmission through the chamber. Different model parameterizations are evaluated in terms of the recovered saturation and petrophysical parameter values. The saturation field is parameterized (1) in Cartesian coordinates, (2) by means of its discrete cosine transform coefficients, and (3) by fixed saturation values in structural elements whose shape and location is assumed known or represented by an arbitrary Gaussian Bell structure. Results show that the estimated saturation fields are in overall agreement with saturations measured by light transmission, but differ strongly in terms of parameter estimates, parameter uncertainties and computational intensity. Discretization in the frequency domain (as in the discrete cosine transform parameterization) provides more accurate models at a lower computational cost compared to spatially discretized (Cartesian) models. A priori knowledge about the expected geologic structures allows for non-discretized model descriptions with markedly reduced degrees of freedom. Constraining the solutions to the known injected gas volume improved estimates of saturation and parameter values of the petrophysical relationship. (C) 2014 Elsevier B.V. All rights reserved.
Resumo:
This paper analyses the effects of manipulating the cognitive complexity of L2 oral tasks on language production. It specifically focuses on self-repairs, which are taken as a measure of accuracy since they denote both attention to form and an attempt at being accurate. By means of a repeated measures de- sign, 42 lower-intermediate students were asked to perform three different tasks types (a narrative, and instruction-giving task, and a decision-making task) for which two degrees of cognitive complexity were established. The narrative task was manipulated along +/− Here-and-Now, an instruction-giving task ma- nipulated along +/− elements, and the decision-making task which is manipu- lated along +/− reasoning demands. Repeated measures ANOVAs are used for the calculation of differences between degrees of complexity and among task types. One-way ANOVA are used to detect potential differences between low- proficiency and high-proficiency participants. Results show an overall effect of Task Complexity on self-repairs behavior across task types, with different be- haviors existing among the three task types. No differences are found between the self-repair behavior between low and high proficiency groups. Results are discussed in the light of theories of cognition and L2 performance (Robin- son 2001a, 2001b, 2003, 2005, 2007), L1 and L2 language production models (Levelt 1989, 1993; Kormos 2000, 2006), and attention during L2 performance (Skehan 1998; Robinson, 2002).
Resumo:
Long-term assessment of the effects of psychotherapy for personality disorders (PDs) in a natural environment is an important task. Such research contributes to enlarge the practice-based evidence, embedded in broad collaborations between clinicians and researchers in psychotherapy for PDs. The present pilot study used rigorous assessment procedures and incorporated feedback loops of outcome information to the therapists in demonstrating the effects of psychotherapy for PD in a natural setting. The number of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), criteria for any PD was the primary outcome (along with psychological distress, depression, impulsiveness, and quality of life as secondary measures), assessed at intake, 6, 12, 18, and 24 months of psychotherapy for N = 13 patients with PD. Data were analyzed using hierarchical linear modeling. Results demonstrated a large pre-post effect (d = 2.22) for the observer-rated measure (primary outcome), and small to medium effects for the secondary outcomes; these results were corroborated by a steady decrease of symptoms over all five time points, which was significant for several outcomes. These results add a piece to the literature by demonstrating the effects of long-term psychotherapy for PDs in increasingly diverse contexts and suggest that practice-oriented research can be carried out in a collaborative and systematic manner.
Resumo:
Using data from free listings and a survey in two villages of Tamil Nadu, India, we discuss local perceptions and uses of water tanks, a traditional irrigation infrastructure. We hypothesize that both farmers and nonfarmers perceive and use water tanks for purposes other than irrigation. We found that informants recognized the importance of water tanks for irrigation, but also acknowledged other socioeconomic uses and ecological functions. Marginal sectors (i.e., Scheduled Castes) use tank resources in more diverse ways than other sectors of the population. Findings are relevant for development. International organizations working on the revival of water tanks aim to transfer water management to farmers for the purpose of irrigation. By recognizing that tanks benefit people other than farmers and in ways other than providing irrigation water, organizations working on tank rejuvenation could achieve a more equitable management of tank resources.
Resumo:
In the present chapter some prototype gas and gas-surface processes occurring within the hypersonic flow layer surrounding spacecrafts at planetary entry are discussed. The discussion is based on microscopic dynamical calculations of the detailed cross sections and rate coefficients performed using classical mechanics treatments for atoms, molecules and surfaces. Such treatment allows the evaluation of the efficiency of thermal processes (both at equilibrium and nonequilibrium distributions) based on state-to-state and state specific calculations properly averaged over the population of the initial states. The dependence of the efficiency of the considered processes on the initial partitioning of energy among the various degrees of freedom is discussed.
Resumo:
Over the last decades, calibration techniques have been widely used to improve the accuracy of robots and machine tools since they only involve software modification instead of changing the design and manufacture of the hardware. Traditionally, there are four steps are required for a calibration, i.e. error modeling, measurement, parameter identification and compensation. The objective of this thesis is to propose a method for the kinematics analysis and error modeling of a newly developed hybrid redundant robot IWR (Intersector Welding Robot), which possesses ten degrees of freedom (DOF) where 6-DOF in parallel and additional 4-DOF in serial. In this article, the problem of kinematics modeling and error modeling of the proposed IWR robot are discussed. Based on the vector arithmetic method, the kinematics model and the sensitivity model of the end-effector subject to the structure parameters is derived and analyzed. The relations between the pose (position and orientation) accuracy and manufacturing tolerances, actuation errors, and connection errors are formulated. Computer simulation is performed to examine the validity and effectiveness of the proposed method.
Resumo:
A simple and effective route has been developed for the synthesis of bimodal (3.6 and 9.4 nm) mesoporous silica materials that have two ordered interconnected pore networks. Mesostructures have been prepared through the self assembly mechanism by using a mixture of polyoxyethylene fluoroalkyl ether and triblock copolymer as building block. The investigation of the RF8(EO)9/P123/water phase diagram evidences that in the considered surfactant range of concentrations, the system is micellar (L1). DLS measurements indicate that this micellar phase is composed of two types of micelles, the size of the first one at around 7.6 nm corresponds unambiguously to the pure fluorinated micelles. The second type of micelles at higher diameter consists of fluorinated micelles which have accommodated a weak fraction of P123 molecules. Thus, in this study the bimodal mesoporous silica are really templated by two kinds of micelles.
Resumo:
The draft forces of soil engaging tines and theoretical analysis compared to existing mathematical models, have yet not been studied in Rio Grande do Sul soils. From the existing models, those which can get the closest fitting draft forces to real measure on field have been established for two of Rio Grande do Sul soils. An Albaqualf and a Paleudult were evaluated. From the studied models, those suggested by Reece, so called "Universal Earthmoving Equation", Hettiaratchi and Reece, and Godwin and Spoor were the best fitting ones, comparing the calculated results with those measured "in situ". Allowing for the less complexity of Reece's model, it is suggested that this model should be used for modeling draft forces prediction for narrow tines in Albaqualf and Paleudut.
Resumo:
The interaction between the soil and tillage tool can be examined using different parameters for the soil and the tool. Among the soil parameters are the shear stress, cohesion, internal friction angle of the soil and the pre-compression stress. The tool parameters are mainly the tool geometry and depth of operation. Regarding to the soils of Rio Grande do Sul there are hardly any studies and evaluations of the parameters that have importance in the use of mathematical models to predict tensile loads. The objective was to obtain parameters related to the soils of Rio Grande do Sul, which are used in soil-tool analysis, more specifically on mathematical models that allow the calculation of tractive effort for symmetric and narrow tools. Two of the main soils of Rio Grande do Sul, an Albaqualf and a Paleudult were studied. Equations that relate the cohesion, internal friction angle of the soil, adhesion, soil-tool friction angle and pre-compression stress as a function of water content in the soil were obtained, leading to important information for use of mathematical models for tractive effort calculation.
Resumo:
OBJECTIVE: To evaluate the applicability of the main categories of risk and morphological factors in the prognosis of gastrointestinal stromal tumors. METHODS: we retrospectively studied fifty-four cases of GIST, assessing the main prognostic factors of this neoplasis: risk levels, topography, size, mitotic index, necrosis, histological subtype and immunophenotype. We also verified their association and the reduction of overall survival. RESULTS: Univariate analysis showed that tumors with mitoses number greater than 5 per 50CGA (high-power fields), the presence of necrosis and a high risk for both the systems proposed by Fletcher and Miettinen had a significant association with reduced survival (p = 0.00001, 0.0056, 0.03 and 0.009, respectively). The remaining analyzed factors (size, histological subtype, topography and immunophenotype) had no such association. Multivariate analysis (Jacard index) showed that the Miettinen degree of risk was the one that best correlated with prognosis. CONCLUSION: the risk criteria of Fletcher and Miettinen are important in assessing the prognosis of patients with gastrointestinal stromal tumors, especially the latter, which adds to the mitotic index and the presence of tumor necrosis.