866 resultados para correlation distance
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Gravity Recovery and Climate Experiment (GRACE) mission is dedicated to measuring temporal variations of the Earth's gravity field. In this study, the Stokes coefficients made available by Groupe de Recherche en Géodésie Spatiale (GRGS) at a 10-day interval were converted into equivalent water height (EWH) for a ~4-year period in the Amazon basin (from July-2002 to May-2006). The seasonal amplitudes of EWH signal are the largest on the surface of Earth and reach ~ 1250mm at that basin's center. Error budget represents ~130 mm of EWH, including formal errors on Stokes coefficient, leakage errors (12 ~ 21 mm) and spectrum truncation (10 ~ 15 mm). Comparison between in situ river level time series measured at 233 ground-based hydrometric stations (HS) in the Amazon basin and vertically-integrated EWH derived from GRACE is carried out in this paper. Although EWH and HS measure different water bodies, in most of the cases a high correlation (up to ~80%) is detected between the HS series and EWH series at the same site. This correlation allows adjusting linear relationships between in situ and GRACE-based series for the major tributaries of the Amazon river. The regression coefficients decrease from up to down stream along the rivers reaching the theoretical value 1 at the Amazon's mouth in the Atlantic Ocean. The variation of the regression coefficients versus the distance from estuary is analysed for the largest rivers in the basin. In a second step, a classification of the proportionality between in situ and GRACE time-series is proposed.
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Dissertação de mestrado em Design e Marketing
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The Amazon tree boa Corallus hortulanus is known for featuring a wide variation in color pattern and design markings. Although there are studies on its polychromatism, none of them addresses the geographic variation in the color pattern of this species. The aim of this study was to describe the chromatic variation found in the populations of C. hortulanus from the southern Amazon Basin and its relationship with geographic distribution of the species. Analysis of both design markings and color patterns on 112 C. hortulanus specimens from the southern Amazon Basin interfluves resulted in the identification of six distinct morphotypes. Grayish-brown coloration and elongated diamond-shaped patterns were the most frequent patterns. Two morphotypes showed a tendency of correlation with the geographical distribution of those species found in Madeira and Juruá Rivers. The small sample size does not allow for a robust conclusion on the possible cause of geographic variation. The distribution of morphological patterns of C. hortullanus in the Amazon Basin suggest that there is gene flow between populations, regardless of geographical distance and natural barriers. The variation in color pattern and markings may represent a phenotypic response to the characteristics of different habitats occupied by the species.
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A modified version of the metallic-phase pseudofermion dynamical theory (PDT) of the 1D Hubbard model is introduced for the spin dynamical correlation functions of the half-filled 1D Hubbard model Mott– Hubbard phase. The Mott–Hubbard insulator phase PDT is applied to the study of the model longitudinal and transverse spin dynamical structure factors at finite magnetic field h, focusing in particular on the sin- gularities at excitation energies in the vicinity of the lower thresholds. The relation of our theoretical results to both condensed-matter and ultra-cold atom systems is discussed.
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Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using sNN−−−−√=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated lumonisity of 7 μb−1. The vm-vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities ϵ2 and ϵ3. On the other hand, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm-vn correlations for n=4 and 5 are found to disagree with ϵm-ϵn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations.
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Tese de Doutoramento em Engenharia Civil.
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[INTRODUCTION] An accurate preoperative rectal cancer staging is crucial to the correct management of the disease. Despite great controversy around this issue, pelvic magnetic resonance (RM) is said to be the imagiologic standard modality. This work aimed to evaluate magnetic resonance accuracy in preoperative rectal cancer staging comparing with the anatomopathological results. METHODS We calculated sensibility, specificity, positive (VP positive) and negative (VP negative) predictive values for each T and N. We evaluated the concordance between both methods of staging using the Cohen weighted K (Kw), and through ROC curves, we evaluated magnetic resonance accuracy in rectal cancer staging. RESULTS 41 patients met the inclusion criteria. We achieved an efficacy of 43.9% for T and 61% for N staging. The respective sensibility, specificity, positive and negative predictive values are 33.3%, 94.7%, 33.3% and 94.7% for T1; 62.5%, 32%, 37.0% and 57.1% for T2; 31.8%, 79%, 63.6% and 50% for T3 and 27.8%, 87%, 62.5% and 60.6% for N. We obtained a poor concordance for T and N staging and the anatomopathological results. The ROC curves indicated that magnetic resonance is ineffective in rectal cancer staging. CONCLUSION Magnetic resonance has a moderate efficacy in rectal cancer staging and the major difficulty is in differentiating T2 and T3.
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Executive functioning (EF), which is considered to govern complex cognition, and verbal memory (VM) are constructs assumed to be related. However, it is not known the magnitude of the association between EF and VM, and how sociodemographic and psychological factors may affect this relationship, including in normal aging. In this study, we assessed different EF and VM parameters, via a battery of neurocognitive/psychological tests, and performed a Canonical Correlation Analysis (CCA) to explore the connection between these constructs, in a sample of middle- aged and older healthy individuals without cognitive impairment (N = 563, 50+ years of age). The analysis revealed a positive and moderate association between EF and VM independently of gender, age, education, global cognitive performance level, and mood. These results confirm that EF presents a significant association with VM performance.
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OBJECTIVE - To evaluate the cardiac abnormalities and their evolution during the course of the acquired immunodeficiency syndrome, as well as to correlate clinical and pathological data. METHODS - Twenty-one patients, admitted to the hospital with the diagnosis of acquired immunodeficiency syndrome, were prospectively studied and followed until their death. Age ranged from 19 to 42 years (17 males). ECG and echocardiogram were also obtained every six months. After death, macro- and microscopic examinations were also performed. RESULTS - The most frequent causes of referral to the hospital were: diarrhea or repeated pneumonias, tuberculosis, toxoplasmosis or Kaposi sarcoma. The most frequent findings were acute or chronic pericarditis (42%) and dilated cardiomyopathy (19%). Four patients died of cardiac problems: infective endocarditis, pericarditis with pericardial effusion, bacterial myocarditis and infection by Toxoplasma gondii. CONCLUSION - Severe cardiac abnormalities were the cause of death in some patients. In the majority of the patients, a good correlation existed between clinical and anatomical-pathological data. Cardiac evaluation was important to detect early manifestations and treat them accordingly, even in asymptomatic patients.
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OBJECTIVE: To evaluate the influence of systolic or diastolic dysfunction, or both on congestive heart failure functional class. METHODS: Thirty-six consecutive patients with a clinical diagnosis of congestive heart failure with sinus rhythm, who were seen between September and November of 1998 answered an adapted questionnaire about tolerance to physical activity for the determination of NYHA functional class. The patients were studied with transthoracic Doppler echocardiography. Two groups were compared: group 1 (19 patients in functional classes I and II) and group 2 (17 patients in functional classes III and IV). RESULTS: The average ejection fraction was significantly higher in group 1 (44.84%±8.04% vs. 32.59%±11.48% with p=0.0007). The mean ratio of the initial/final maximum diastolic filling velocity (E/A) of the left ventricle was significantly smaller in group 1 (1.07±0.72 vs. 1.98±1.49 with p=0.03). The average maximum systolic pulmonary venous velocity (S) was significantly higher in group 1 (53.53cm/s ± 12.02cm/s vs. 43.41cm/s ± 13.55cm/s with p=0.02). The mean ratio of maximum systolic/diastolic pulmonary venous velocity was significantly higher in group 1 (1.52±0.48 vs. 1.08±0.48 with p=0.01). A predominance of pseudo-normal and restrictive diastolic patterns existed in group 2 (58.83% in group 2 vs. 21.06% in group 1 with p=0.03). CONCLUSION: Both the systolic dysfunction index and the patterns of diastolic dysfunction evaluated by Doppler echocardiography worsened with the evolution of congestive heart failure.
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OBJECTIVE: To evaluate the performance of the turbidimetric method of C-reactive protein (CRP) as a measure of low-grade inflammation in patients admitted with non-ST elevation acute coronary syndromes (ACS). METHODS: Serum samples obtained at hospital arrival from 68 patients (66±11 years, 40 men), admitted with unstable angina or non-ST elevation acute myocardial infarction were used to measure CRP by the methods of nephelometry and turbidimetry. RESULTS: The medians of C-reactive protein by the turbidimetric and nephelometric methods were 0.5 mg/dL and 0.47 mg/dL, respectively. A strong linear association existed between the 2 methods, according to the regression coefficient (b=0.75; 95% C.I.=0.70-0.80) and correlation coefficient (r=0.96; P<0.001). The mean difference between the nephelometric and turbidimetric CRP was 0.02 ± 0.91 mg/dL, and 100% agreement between the methods in the detection of high CRP was observed. CONCLUSION: In patients with non-ST elevation ACS, CRP values obtained by turbidimetry show a strong linear association with the method of nephelometry and perfect agreement in the detection of high CRP.
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OBJECTIVE: To verify the association of serum markers of myocardial injury, such as troponin I, creatinine kinase, and creatinine kinase isoenzyme MB, and inflammatory markers, such as tumor necrosis factor alpha (TNF-alpha), C-reactive protein, and the erythrocyte sedimentation rate in the perioperative period of cardiac surgery, with the occurrence of possible postpericardiotomy syndrome. METHODS: This was a cohort study with 96 patients undergoing cardiac surgery assessed at the following 4 different time periods: the day before surgery (D0); the 3rd postoperative day (D3); between the 7th and 10th postoperative days (D7-10); and the 30th postoperative day (D30). During each period, we evaluated demographic variables (sex and age), surgical variables (type and duration , extracorporeal circulation), and serum dosages of the markers of myocardial injury and inflammatory response. RESULTS: Of all patients, 12 (12.5%) met the clinical criteria for a diagnosis of postpericardiotomy syndrome, and their mean age was 10.3 years lower than the age of the others (P=0.02). The results of the serum markers for tissue injury and inflammatory response were not significantly different between the 2 assessed groups. No significant difference existed regarding either surgery duration or extracorporeal circulation. CONCLUSION: The patients who met the clinical criteria for postpericardiotomy syndrome were significantly younger than the others were. Serum markers for tissue injury and inflammatory response were not different in the clinically affected group, and did not correlate with the different types and duration of surgery or with extracorporeal circulation.
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La motilidad celular orientada (o mecanismo quimiotáctico de orientación), es una respuesta celular a señales moleculares de su micro-ambiente necesaria para modular la distribución celular en sitios específicos y con elevada precisión. Nuestra hipótesis establece que la migración orientada de células neurales es regulada por gradientes de concentración de moléculas solubles liberadas por sus regiones "blanco". Este proyecto es continuación del estudio de la quimiotaxis de células de cresta neural (CCN) y de neuronas ventriculares (NV) inducida respectivamente por factores difusibles de la región del futuro ganglio ciliar y del bulbo olfatorio.En el sistema de CCN, hemos caracterizado como moléculas quimiotácticas a la quimioquina Stromal Cell-Derived Factor-1, y los factores tróficos Stem Cell Factor y Neurotrophic Factor-3, habiendo determinado la expresión de sus respectivos receptores CXCR4, TrkC y p75 en la población de CCN mesencefálicas de ambrión de pollo. Actualmente, estamos desarrollando experimentos con el Ciliary Neurotrophic Factor y factores de la familia Bone Morphogenetic Proteins. Además de la estrategia experimental in vitro, hemos determinado en el embrión entero la expresión de las moléculas quimioatractantes mediante hibridación in situ del ARNm y la presencia de las respectivas proteínas mediante inmunocitoquímica. En el sistema de NV, estamos analizando la motilidad celular en relación con moléculas liberadas por el bulbo olfatorio. En los dos sistemas biológicos, estamos analizando elementos de la transducción de señales y cambios en el citoesqueleto, en ambos casos asociados con la respuesta temprana en la orientación quimiotáctica de la célula. Asimismo, en ambos sistemas biológicos, evaluamos los efectos del etanol sobre la migración y distribución celular, en condiciones equivalentes a las que inducen el Sindrome Fetal Alcohólico en mamíferos.En base a resultados ya obtenidos en experimentos in vitro, en la presente etapa intentaremos su caracterización in vivo mediante el bloqueo funcional de las moléculas quimiotácticas (y/o sus receptores) sobre embriones enteros, mediante silenciamiento con ARNsi (o morfolinos específicos) mediante electroporación, y posterior determinación de la distribución celular mediante marcadores específicos anti-CCN (o lipofílicos de tipo DiI).Los resultados permitirán mejorar el conocimiento del mecanismo de la migración celular orientada y aportar al diseño de recursos diagnósticos, terapéuticos o de control de anomalías embrionarias o patologías tumorales por mala distribución celular como las Neurocristopatías, o inducidas por tóxicos exógenos como el Sindrome Fetal Alcohólico.
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Identificación y caracterización del problema: El problema que guía este proyecto, pretende dar respuesta a interrogantes tales como: ¿De qué modo el tipo de actividades que se diseñan, se constituyen en dispositivos posibilitadores de la comprensión de los temas propios de cada asignatura, por parte de los alumnos? A partir de esta pregunta, surge la siguiente: Al momento de resolver las actividades, ¿qué estrategias cognitivas ponen en juego los estudiantes? y ¿cuáles de ellas favorecen procesos de construcción del conocimiento? Hipótesis: - Las asignaturas cuyas actividades están elaboradas bajo la metodología de Aprendizaje Basado en Problemas y Estudio de Casos, propician aprendizajes significativos por parte de los estudiantes. - Las actividades elaboradas bajo la metodología del Aprendizaje Basado en Problemas y el Estudio de Casos requieren de procesos cognitivos más complejos que los que se implementan en las de tipo tradicional. Objetivo: - Identificar el impacto que tienen las actividades de aprendizaje de tipo tradicional y las elaboradas bajo la metodología de Aprendizaje Basado en Problemas y Estudio de Casos, en el aprendizaje de los alumnos. Materiales y Métodos: a) Análisis de las actividades de aprendizaje del primero y segundo año de la carrera de Abogacía, bajo lamodalidad a Distancia. b) Entrevistas tanto a docentes contenidistas como así también a los tutores. c) Encuestas y entrevistas a los alumnos. Resultados esperados: Se pretende confirmar que las actividades de aprendizaje, diseñadas bajo la metodología del Aprendizaje Basado en Problemas y el Estudio de Casos, promueven aprendizajes significativos en los alumnos. Importancia del proyecto y pertinencia: La relevancia del presente proyecto se podría identificar a través de dos grandes variables vinculadas entre sí: la relacionada con el dispositivo didáctico (estrategias implementadas por los alumnos) y la referida a lo institucional (carácter innovador de la propuesta de enseñanza y posibilidad de extenderla a otras cátedras). El presente proyecto pretende implementar mejoras en el diseño de las actividades de aprendizaje, a fin de promover en los alumnos la generación de ideas y soluciones responsables y el desarrollo de su capacidad analítica y reflexiva.
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In Tbilisi according to the data of the complex monitoring of light ions concentration, radon and sub-micron aerosols the effect of feedback of intensity of ionizing radiation with the light ions content in atmosphere is discovered.