RESUMO
The current study examined associations among sports participation (SP), athletic identity (AI), weight status, and eating pathology, and whether these relations differed by gender. Data come from male and female first-year college students who participated in the Tufts Longitudinal Health Study (TLHS) between 1999-2007 (N=712). Relations among SP, AI, actual and perceived weight statuses, Eating Disorders Inventory (EDI) subscale scores, and indices of body shape concern and restrictive eating were examined with hierarchical ordinary least squares (OLS) regression. Associations between SP and eating pathology among females were moderated by perceived weight status. By contrast, relations between males' EDI subscales scores and SP were moderated by ethnicity, as well as by actual weight status. Our findings support that sports participation alone neither promotes nor protects against eating pathology among males and females.
Assuntos
Imagem Corporal , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Autoimagem , Identificação Social , Esportes/psicologia , Adolescente , Peso Corporal , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Estudos Longitudinais , Masculino , Fatores Sexuais , Estudantes , Inquéritos e Questionários , Universidades , Adulto JovemRESUMO
We believe that methanol is the most versatile synthetic fuel available and its use could stretch or eventually substitute for, the disappearing reserves of low-cost petroleum resources. Methanol could be used now as a means for marketing economically the natural gas that is otherwise going to waste in remote locations. If methanol were used as an additive to gasoline at a rate of 5 to 15 percent, for use in internal combustion engines, there would be an immediate reduction in atmospheric pollution, there would be less need for lead in fuel, and automobile performance would be improved. With increasing production of fuel-grade methanol from coal and other sources, we foresee the increasing use of methanol for electrical power plants, for heating, and for other fuel applications. We hope that a practical methanol fuel cell will be commercially available by the time that methanol becomes plentiful for fuel purposes. Methanol offers a particularly attractive form of solar-energy conservation, since agricultural and forest waste products can be used as the starting material. Indeed, at 1 percent conversion efficiency the forest lands could supply the entire present energy requirements of the United States.
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Forty-eight patients were prospectively evaluated following coronary artery bypass grafting (CABG) in order to determine values for diaphragmatic mobility by sonography, to compare diaphragmatic motion to chest x-ray findings, to relate diaphragmatic motion to pulmonary function tests, and to determine whether use of the left internal mammary artery (LIMA), aortic cross-clamp time, or other clinical variables were predictive of diaphragmatic dysfunction. Mean left diaphragmatic motion was 2.8 +/- 1.1 cm (range, 1.0 to 5.7 cm), mean right diaphragmatic motion was 3.9 +/- 1.1 cm (range, 1.8 to 6.4 cm), and ratio of left to right motion was 0.74 +/- 0.27 (range, 0.19 to 1.4). Forty-one patients had normally positioned diaphragms on the chest x-ray film; four of these had poor mobility by ultrasonography (< 1.6 cm). Of the seven elevated left hemidiaphragms on chest x-ray films, three had an excursion of 1.6 cm or more by ultrasonography. The mean FVC for all patients was 59 +/- 13 percent of predicted. There was no relationship between diaphragmatic mobility and FVC or negative inspiratory pressure. The diaphragmatic motion in 36 patients having LIMA grafting was similar to those without (2.7 +/- 1.2 cm [n = 36] vs 2.8 +/- 0.8 cm [n = 12], respectively). Aortic cross-clamp time and respiratory symptoms also did not correlate with diaphragmatic mobility. Sonography can be used in the evaluation of diaphragmatic motion after CABG and may be more accurate in detecting a poorly mobile diaphragm than is the chest x-ray film.
Assuntos
Ponte de Artéria Coronária , Diafragma/diagnóstico por imagem , Diafragma/fisiologia , Mecânica Respiratória/fisiologia , Ponte de Artéria Coronária/métodos , Feminino , Humanos , Inalação/fisiologia , Masculino , Pessoa de Meia-Idade , Movimento , Revascularização Miocárdica , Estudos Prospectivos , Radiografia Torácica , Fatores de Tempo , Ultrassonografia , Capacidade Vital/fisiologiaRESUMO
Iodipimide ethyl ester (IDE) can be formulated as dense spherical particles with narrow diameter distribution. When IDE particles are injected intravenously, the Kupffer cells of the hepatic sinusoids accumulate particles within 10 to 20 minutes, after which the clearance and excretion of IDE takes place. During the uptake phase, the dense particles act as scattering sites, increasing the echogenicity of normal liver tissue. In comparison, tumors and other lesions remain at pre-injection echogenicity, as they lack Kupffer cells and therefore do not retain particles. This report provides initial studies of contrast enhancement in rabbit livers with implanted VX2 tumors, scanned in vivo and evaluated ex vivo using pulse-echo techniques. The distribution of particles within hepatic lobules may explain why the observed echogenicity is greater than that predicted by single-particle backscatter theory. Directions for future improvements are discussed.
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Meios de Contraste , Iodopamida , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Animais , Transplante de Neoplasias , Coelhos , UltrassonografiaRESUMO
Two case reports of tunica albuginea cysts are presented. Imaging of this lesion by high resolution ultrasonography and the impact of this technique on management are considered.
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Cistos/diagnóstico , Doenças do Pênis/diagnóstico , Ultrassonografia , Adulto , Cistos/patologia , Humanos , Masculino , Doenças do Pênis/patologia , Escroto/patologia , Testículo/patologiaRESUMO
Wave space is described nonmathematically for design and interpretation of ultrasound scattering experiments. By considering ultrasound scattering from a variety of targets and geometries, the wave space approach is shown to describe target characteristics in terms of spatial frequencies and their amplitudes. Experimental limitations for determining effective spacing of scattering structures and scattering medium anisotropy are discussed.
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Ultrassonografia , Fenômenos Biofísicos , Biofísica , Análise de Fourier , Modelos BiológicosRESUMO
A method has been developed for detecting and imaging the relative "stiffness," or elasticity of tissues. Externally applied vibration at low frequencies (10-1000 Hz) is used to induce oscillations within soft tissues, and the motion is detected by Doppler ultrasound. The results are displayed in a format resembling conventional Doppler color flow mapping, and are termed "sonoelasticity images." Preliminary experiments indicate that these novel images may be useful for detecting hard tumors in the prostate, liver, breast, and other organs.
Assuntos
Elasticidade , Ultrassonografia/métodos , Vibração , Animais , Humanos , Neoplasias Hepáticas Experimentais/diagnóstico , Masculino , Modelos Estruturais , Hiperplasia Prostática/diagnóstico , Coelhos , Neoplasias de Tecidos Moles/diagnóstico , UltrassomRESUMO
Recently, a number of methods have been developed that make it possible to image the elastic properties of soft tissues. Because certain types of tissues such as malignant lesions, for example, have elastic properties that are markedly different from surrounding tissues, elasticity imaging could provide a significant adjunct to current diagnostic ultrasonic methods. Further, elasticity imaging techniques could be used to augment the study of tissues that change their elastic properties, such as skeletal and cardiac muscle. In this paper, we survey some of the previous work done in the related field of biomechanics, and we review measurement techniques from the 1950s to the 1980s. Different approaches to elastic imaging and signal processing are then discussed and a lexicography for elastic imaging is introduced. It is hoped that this nomenclature will provide a meaningful categorization of various approaches and will make evident the inherent parameters displayed and conditions applied in deriving the resulting images. Key assumptions and signal processing approaches are also reviewed. Finally, directions for future work are suggested.
Assuntos
Tecido Elástico/diagnóstico por imagem , Processamento de Sinais Assistido por Computador/instrumentação , Animais , Fenômenos Biomecânicos , Tecido Elástico/fisiologia , Humanos , Imagens de Fantasmas , UltrassonografiaRESUMO
The goal of "sonoelasticity imaging" is to differentiate between normal soft tissues and hard lesions. This is done by measuring and then displaying the ultrasound Doppler spectrum of regions within tissues which are mechanically forced with low frequency (20-1000 Hz) vibrations. The resolution and sensitivity of the technique ultimately rest on the spatial resolution of ultrasound Doppler detection, the low frequency mechanical properties of tissues, and the vibration response of layered, inhomogeneous regions with hard tumor inclusions and complicated boundary conditions set by the presence of skin, bones and other regions. An initial investigation has measured some tissue stiffness parameters, and applied these in a NASTRAN finite element analysis to simulate a prostate tumor in the pelvic cavity. The measurements show a wide separation between the elastic modulus of tumors and soft tissues such as muscle and prostate. NASTRAN analyses show the ability to delineate regions of different elasticity based on the pattern of vibration amplitudes. The ability to change vibration frequency within the 100-300 Hz band seems particularly helpful in simulations and experiments which visualize small stiff inclusions in tissues. Preliminary results support the postulate that sonoelasticity imaging can provide useful information concerning tissue properties that are not otherwise obtainable.
Assuntos
Simulação por Computador , Elasticidade , Neoplasias da Próstata/diagnóstico , Ultrassonografia/métodos , Vibração , Tecido Conjuntivo/anatomia & histologia , Humanos , Masculino , Neoplasias de Tecidos Moles/diagnóstico , UltrassomRESUMO
Ultrasonic attenuation coefficients of liver have been derived from echoes received by a modified commercial B-scan imaging instrument. Values have been measured from selected regions within liver scans of 59 individuals, of which 15 cases were presumed normal (based on medical histories), and the remainder were involved with diffuse liver disease such as alcoholic cirrhosis, chemotherapy toxicity, chronic hepatitis, and liver metastases. Medical histories on most individuals include the results of serum liver function enzymes, conventional B-scan examinations, and exposure to drugs and alcohol. The results of CT abdominal scans (N = 13) and/or liver biopsy (N = 12) were also available. The results show that normal attenuation values for human liver are 0.054 +/- 0.009 Np/cm-MHz (0.47 dB/cm-MHz) with a frequency dependence of fn, where n = 1.05 +/- 0.25, in agreement with in vitro studies of mammalian liver. In diffuse liver disease, no relationship was found between the attenuation coefficient and the results of CT or conventional ultrasonic examination. A trend towards higher attenuation with increased fibrosis and fat, as graded from liver biopsies, was noted, but the results were generally not statistically significant. However, a significant correlation was found between high values of attenuation and abnormal liver function tests. High attenuation is also found with ingestion of alcohol, chemotherapeutic agents, and steroids, all of which may affect liver composition.
Assuntos
Hepatopatias/patologia , Fígado/patologia , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Criança , Pré-Escolar , Humanos , Fígado/anatomia & histologia , Hepatopatias/diagnóstico , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Valores de Referência , Tomografia Computadorizada por Raios XRESUMO
Ultrasonic backscatter and attenuation coefficients of a medium can be increased by the addition of solid, micron sized inhomogeneities. A potentially useful agent for ultrasonic contrast of liver images has been identified. Iodipamide ethyl ester (IDE) particles can be produced in the form of dense, relatively incompressible solids with high impedance mismatch to water. The chemical, biomechanical, and pharmacological properties of the small, uniform diameter IDE particles permit safe intravenous injection followed by rapid accumulation by reticuloendothelial (RE) cells of the liver and spleen, and later elimination from these organs. Since the particles are phagocytized by RE cells, present in normal liver but not in tumors and many lesions, the selective enhancement of ultrasonic backscatter should improve detectability of lesions which are hypo- or iso-echoic compared to surrounding tissue. The mechanisms of particle-ultrasound interaction may be described by relative motion attenuation, and scattering from a cloud of dense, incompressible spheres for the case of IDE particles in agar. Thus, values of attenuation and backscatter can be controlled by choice of ultrasound frequency and particle concentration and size. When the particles are accumulated in rat livers, additional mechanisms induce attenuation and backscatter in excess of that predicted by IDE in agar. This preliminary work demonstrates that solid, biocompatible particles may be useful as an ultrasonic contrast agent.
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Iodopamida/análogos & derivados , Fígado/anatomia & histologia , Ultrassonografia , Animais , Tamanho da Partícula , Ratos , Ratos EndogâmicosRESUMO
A patient suspected of having an obstruction to the inferior vena cava developed a "hot spot" in the liver when an inferior vena cavogram was performed with Tc-99-sulfur colloid. The "hot spot" was demonstrated to be the result of the collateral circulation.
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Fígado/diagnóstico por imagem , Veia Cava Inferior , Adenocarcinoma/complicações , Constrição Patológica , Humanos , Neoplasias Renais/complicações , Hepatopatias/etiologia , Masculino , Pessoa de Meia-Idade , Cintilografia , Veia Cava Inferior/patologiaRESUMO
Canonical correlation described continuity and discontinuity in salient covariates of emotional and interactional components in parent-child relationships among NYLS participants from middle adolescence to young adulthood. The results underscore the importance of multiple indicators of parent-child relationship quality, and their implications for assessment and intervention efforts are discussed.
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Afeto , Relações Pais-Filho , Desenvolvimento da Personalidade , Adaptação Psicológica , Adolescente , Adulto , Conflito Psicológico , Feminino , Seguimentos , Identidade de Gênero , Humanos , Estudos Longitudinais , Masculino , New York , Determinação da Personalidade , TemperamentoRESUMO
The relationship between easy/difficult temperament and adjustment from middle adolescence to young adulthood was examined. Cluster analysis revealed four groups of individuals via composite temperament scores over three points of measurement. Multivariate analyses indicated that extremely difficult temperament was associated with poorer psychosocial functioning in childhood and young adulthood.
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Adaptação Psicológica , Desenvolvimento da Personalidade , Ajustamento Social , Temperamento , Adolescente , Adulto , Ansiedade/psicologia , Depressão/psicologia , Feminino , Humanos , Individualidade , Masculino , Apego ao Objeto , Comportamento SocialRESUMO
Relationships between perceived parental acceptance and adolescent self-competence were examined in 214 sixth- and seventh-grade students by both adolescent and parental gender. Results indicated that for boys, paternal but not maternal, acceptance significantly predicted self-competence, while the opposite pattern was found for girls. In addition, self-worth significantly predicted maternal and paternal acceptance for both boys and girls. The consistency of these findings with current models of human development is discussed, along with their implications for research.
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Comportamento do Adolescente , Relações Pais-Filho , Autoimagem , Adolescente , Criança , Feminino , Humanos , Masculino , Fatores SexuaisRESUMO
The differential role of various body attitudes in predicting the self-concepts of late adolescents (124 males and 218 females), enrolled in introductory psychology courses, was assessed. Subjects rated 24 body characteristics in terms of 1) how physically attractive they assumed these parts of their bodies were, and 2) how physically effective they assumed them to be; subjects also responded to a short self-concept scale. In accordance with the theory of Erikson (1968) and of McCandless (1970), it was expected that attractiveness attitudes should contribute more to the self-concepts of females than should effectiveness attitudes, while a reverse pattern of interrelatedness was expected for males. Results indicated a higher correspondence between what are seen as attractive body parts and what are viewed as effective body components for males than for females. Moreover, findings from step-wise multiple regression analyses of each sex group's ratings of the body parts for attractiveness and effectiveness, respectively, each with the criterion variable constituting mean self-concept score, were consistent with expectations. For females, the multiple correlation between attractiveness ratings and self-concept was greater than the multiple correlation between effectiveness ratings and self-concept, and more attractiveness variables than effectiveness variables were significant predictors of self-concept. The converse of these findings were obtained with the males' data. The relevance of these results for theories of personality development were discussed.