522 research outputs found

    Relativistic quantum dynamics of scalar bosons under a full vector Coulomb interaction

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    The relativistic quantum dynamics of scalar bosons in the background of a full vector coupling (minimal plus nonminimal vector couplings) is explored in the context of the Duffin-Kemmer-Petiau formalism. The Coulomb phase shift is determined for a general mixing of couplings and it is shown that the space component of the nonminimal coupling is a {\it sine qua non} condition for the exact closed-form scattering amplitude. It follows that the Rutherford cross section vanishes in the absence of the time component of the minimal coupling. Bound-state solutions obtained from the poles of the partial scattering amplitude show that the time component of the minimal coupling plays an essential role. The bound-state solutions depend on the nonminimal coupling and the spectrum consists of particles or antiparticles depending on the sign of the time component of the minimal coupling without chance for pair production even in the presence of strong couplings. It is also shown that an accidental degeneracy appears for a particular mixing of couplings.Comment: 8 pages, 1 table. arXiv admin note: text overlap with arXiv:1403.603

    Microstructure and morphoquantitative study of pineal gland in santa ines sheep

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    O presente estudo avaliou os aspectos morfoquantitativos e qualitativos da glândula pineal em fêmeas de ovinos da raça Santa Inês em atividade reprodutiva e anestro fisiológico. Foram utilizados sete ovinos, fêmeas e adultas, coletados em frigoríficos da região de Brasília-DF. Estes não apresentavam sinais clínicos relacionados a afecções do sistema nervoso. Os encéfalos foram retirados e suas dimensões mensuradas. Posteriormente foram seccionados para expor a glândula pineal e mensurar suas dimensões. Os fragmentos do diencéfalo, contendo a glândula pineal, foram submersos em solução aquosa a 20% de formaldeído e posteriormente submetidos a técnicas histológicas convencionais. Para a avaliação morfoquantitativa desta glândula, foram empregadas as colorações Hematoxilia-Eosina, Azul de Toluidina e Tricrômio de Gomori. O encéfalo teve um comprimento médio de 67,25 ± 1,75 mm e a largura média de 58,97 ± 4,0 mm. Já a glândula pineal apresentou o comprimento médio de 6,98 ± 0,79 mm e a largura média de 6,40 ± 1,35 mm. Diante da análise microscópica, foi obtida uma média de 86,27 ± 30,44 pinealócitos por campo. Ao ser aplicado o teste de correlação de Pearson, o número de pinealócitos apresentou fraca correlação linear negativa (r = -0,11) em relação ao comprimento da glândula pineal e uma fraca correlação linear positiva (r = 0,39) em relação à largura da mesma. Portanto o número de pinealócitos apresenta uma maior correlação com a largura da glândula do que com o seu comprimento. Mastócitos estiveram presentes em apenas um animal (14,28%) e as concreções calcareas foram observadas em dois animais (28,57%). A glândula se mostrou envolta por uma cápsula de tecido conjuntivo com ausência de projeções para o parênquima. _________________________________________________________________________________ ABSTRACTThis study examined morphologic aspects of the pineal gland in Santa Ines sheep in anoestrus physiological and reproductive activity. Seven female adult sheep were collected at slaughterhouses in the region of Brasilia-DF, with no clinical signs related to diseases of the nervous system were used. The brains were removed and their dimensions were measured. The brains were sectioned to expose and measure the pineal gland. The fragments of the diencephalon containing the pineal gland were immersed in 20% formaldehyde solution. Subsequently, the fragments were submitted to conventional histological techniques. The Hematoxylin-eosin, Toluidine blue and Gomori trichrome staining were used for a morphoquantitative analysis. The brain had an average length of 67.25 ± 1.75 mm and average width of 58.97 ± 4.0 mm. The pineal gland had an average length of 6.98 ± 0.79 mm and average width of 6.40 ± 1.35 mm. The quantitative analysis showed an average 86.27 ± 30.44 of pinealocytes per field. According to the Pearson correlation test, the number of pinealocytes showed a weak negative linear correlation (r = -0.11) with the length of the pineal gland and a weak positive linear correlation (r = 0.39) with the width. Therefore, the number of pinealocytes has a stronger correlation with the width of the gland compared to the length. Mastocytes were present in only one animal (14.28%). Calcareous concretions were observed in two animals (28.57%). The connective tissue formed the capsule surrounding the gland with no projections into the parenchyma

    Analysis of the backpack loading efects on the human gait

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    Gait is a simple activity of daily life and one of the main abilities of the human being. Often during leisure, labour and sports activities, loads are carried over (e.g. backpack) during gait. These circumstantial loads can generate instability and increase biomechanicalstress over the human tissues and systems, especially on the locomotor, balance and postural regulation systems. According to Wearing (2006), subjects that carry a transitory or intermittent load will be able to find relatively efficient solutions to compensate its effects.info:eu-repo/semantics/publishedVersio

    Force irradiation effects during upper limb diagonal exercises on contralateral muscle activation

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    The aim of this study was to explore the force irradiation effects of upper limb isometric diagonal exercises on shoulder muscle activities. Interactions among diagonal directions, contraction intensities (moderate and maximum) and sex were assessed. Thirty healthy subjects (11 males) performed isometric unilateral diagonal exercises based on proprioceptive neuromuscular facilitation technique in an isokinetic dynamometer with their dominant upper limbs. The second diagonal for flexion and for extension were assessed while the participants performed their maximum isometric torque (MIT) and at 25% of their MIT. During the exercise the muscle activity of the medial deltoid, pectoralis major and upper trapezius in the non-dominant (non-exercised) upper limbs of the participants was recorded by surface electromyography. The highest muscle activity occurred in the upper trapezius during the diagonal for flexion (27% of maximum isometric voluntary contractions). Upper trapezius and pectoralis major were more active during the diagonal for flexion than diagonal for extension (p 0.05). In conclusion, we observed that force irradiation during upper limb diagonal exercises is affected by diagonal direction, contraction intensity and sex when performed by healthy participants.info:eu-repo/semantics/publishedVersio

    Crack-cocaine users have less family cohesion than alcohol users

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    Objective: Many studies correlate characteristics of family functioning and the development of drug addiction. This study sought to evaluate and compare the family environment styles of two groups of psychoactive substance users: 1) alcohol-only users and 2) crack-cocaine users. Methods: Three hundred and sixty-four users of alcohol, crack-cocaine, and other drugs, recruited from research centers in four Brazilian capitals participated in this study. Subjects were evaluated through the Family Environment Scale and the Addiction Severity Index, 6th version (ASI-6). ASI-6 t-scores were compared by analysis of variance (ANOVA) and post-hoc tests. A final model was obtained using a logistic regression analysis. All analyses were adjusted for partner, age, and psychiatric t-score. Results: We found a significant difference between groups in the cohesion subscale (p = 0.044). The post-hoc test revealed a difference of 1.06 points (95% CI 0.11-2.01) between groups 1 (6.45 +/- 0.28) and 2 (5.38 +/- 0.20). No significant between-group differences were observed in the other subscales. However, categorical analyses of variables regarding family dynamic showed that crack users more often reported that sometimes people in their family hit each other (30.4% vs. 13.2%, p = 0.007) and that people in their family frequently compared each other regarding work and/or school achievement (57.2% vs. 42.6%, p = 0.041). Conclusion: These results suggest that families of crack-cocaine users are less cohesive than families of alcohol users. This type of family environment may affect treatment outcome, and should thus be adequately approached.SENADNational Institutes of Health/National Institute on Drug AbuseUniv Fed Rio do Grande UFRGS, HCPA, CPAD, Porto Alegre, RS, BrazilHCPA, Unidade Bioestat, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, Lab Biossinais Fenomenol & Cognicao, Inst Psicol, Porto Alegre, RS, BrazilUniv Fed Sao Paulo UNIFESP, Dept Psicobiol, Sao Paulo, SP, BrazilUniv Fed Rio de Janeiro UFRJ, Inst Psiquiatria, Rio De Janeiro, RJ, BrazilUniv Fed Sao Paulo UNIFESP, Dept Psicobiol, Sao Paulo, SP, BrazilSENAD: TC 005/2005Web of Scienc

    Kinin B(1) receptor deficiency leads to leptin hypersensitivity and resistance to obesity

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    OBJECTIVE-Kinins mediate pathophysiological processes related to hypertension, pain, and inflammation through the activation of two G-protein-coupled receptors, named B(1) and B(2). Although these peptides have been related to glucose homeostasis, their effects on energy balance are still unknown.RESEARCH DESIGN and METHODS-Using genetic and pharmacological strategies to abrogate the kinin B(1) receptor in different animal models of obesity, here we present evidence of a novel role for kinins in the regulation of satiety and adiposity.RESULTS-Kinin B(1) receptor deficiency in mice (B(1)(-/-)) resulted in less fat content, hypoleptinemia, increased leptin sensitivity, and robust protection against high-fat diet-induced weight gain. Under high-fat diet, B(1)(-/-) also exhibited reduced food intake, improved lipid oxidation, and increased energy expenditure. Surprisingly, B(1) receptor deficiency was not able to decrease food intake and adiposity in obese mice lacking leptin (ob/ob-B(1)(-/-)). However, ob/ob-B(1)(-/-) mice were more responsive to the effects of exogenous leptin on body weight and food intake, suggesting that B(1) receptors may be dependent on leptin to display their metabolic roles. Finally, inhibition of weight gain and food intake by B(1) receptor ablation was pharmacologically confirmed by long-term administration of the kinin B(1) receptor antagonist SSR240612 to mice under high-fat diet.CONCLUSIONS-Our data suggest that kinin B(1) receptors participate in the regulation of the energy balance via a mechanism that could involve the modulation of leptin sensitivity.Universidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilUniv Mogi das Cruzes, Mogi Das Cruzes, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilSanofi Aventis, Montpellier, FranceUniversidade Federal de São Paulo, Dept Med, BR-04023062 São Paulo, BrazilInst Natl Sante & Rech Med, Dept Renal & Cardiac Remodeling, U858 I2MR, Toulouse, FranceUniv Toulouse 3, Inst Med Mol Rangueil, F-31062 Toulouse, FranceInst Natl Rech Agron AgroParisTech, UMR914 Nutr Physiol & Ingest Behav, Paris, FranceMax Delbruck Ctr Mol Med, Berlin, GermanyUniversidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04023062 São Paulo, BrazilWeb of Scienc
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