988 resultados para Line-region relations
Resumo:
We consider the numerical treatment of the optical flow problem by evaluating the performance of the trust region method versus the line search method. To the best of our knowledge, the trust region method is studied here for the first time for variational optical flow computation. Four different optical flow models are used to test the performance of the proposed algorithm combining linear and nonlinear data terms with quadratic and TV regularization. We show that trust region often performs better than line search; especially in the presence of non-linearity and non-convexity in the model.
Resumo:
Como parte do projeto GENACIS, este artigo visou estimar a prevalência de depressão em amostra urbana de São Paulo, Brasil, assim como a associação entre depressão e padrão de uso de álcool segundo gênero. Para tanto, foi realizado inquérito epidemiológico com amostra probabilística e por conglomerados, com um total de 2083 adultos. Utilizou-se o CIDI SF para identificação de depressão. A análise estatística utilizou o teste de Rao Scott e regressão logística multivariada. A taxa de resposta foi de 74,9%. Predominaram mulheres (58,8%), menores de 40 anos de idade (52%). A prevalência de depressão foi de 28,3% para as mulheres e 12,7% para os homens. Entre os homens, 61,1% são de bebedores no último ano e a depressão esteve associada ao padrão de consumo de álcool, à maior frequência de binge drinking e à presença de problemas decorrentes do álcool. Entre as mulheres, 69,5% são abstinentes e a depressão se associou à convivência com cônjuge com problemas devidos ao álcool. Os resultados ressaltam que a associação entre depressão e consumo de álcool é distinta entre os gêneros.
Resumo:
As part of the GENACIS project, this paper sought to assess the prevalence of depression in an urban sample in the city of Sao Paulo, Brazil, as well as the association between depression and alcohol abuse according to gender. To achieve this, an epidemiological survey was conducted using a stratified probability sample, including 2,083 adults. CIDI SF was used to identify depression. The Rao Scott test and multivariate logistic regression were used for statistical analysis. The response rate was 74.9%. Females (58.3%) under 40 years of age (52%) were predominant. The prevalence of depression was 28.3% for women and 12.7% for men. Most men declared being drinkers (61.1%) in the last year. Depression was associated with an alcohol drinking pattern, mostly binge drinking, in addition to the occurrence of problems derived from alcohol use. Most women declared being abstainers (69.5%). Depression was associated with cohabiting with spouses with alcohol-related problems. Results reveal that the association between depression and alcohol consumption is distinct between genders.
Resumo:
As part of the GENACIS project, this paper sought to assess the prevalence of depression in an urban sample in the city of São Paulo, Brazil, as well as the association between depression and alcohol abuse according to gender. To achieve this, an epidemiological survey was conducted using a stratified probability sample, including 2,083 adults. CIDI SF was used to identify depression. The Rao Scott test and multivariate logistic regression were used for statistical analysis. The response rate was 74.9%. Females (58.3%) under 40 years of age (52%) were predominant. The prevalence of depression was 28.3% for women and 12.7% for men. Most men declared being drinkers (61.1%) in the last year. Depression was associated with an alcohol drinking pattern, mostly binge drinking, in addition to the occurrence of problems derived from alcohol use. Most women declared being abstainers (69.5%). Depression was associated with cohabiting with spouses with alcohol-related problems. Results reveal that the association between depression and alcohol consumption is distinct between genders.
Resumo:
The positional relationships among all of the visible organelles in a densely packed region of cytoplasm from an insulin secreting, cultured mammalian cell have been analyzed in three dimensions (3-D) at ≈6 nm resolution. Part of a fast frozen/freeze-substituted HIT-T15 cell that included a large portion of the Golgi ribbon was reconstructed in 3-D by electron tomography. The reconstructed volume (3.1 × 3.2 × 1.2 μm3) allowed sites of interaction between organelles, and between microtubules and organellar membranes, to be accurately defined in 3-D and quantitatively analyzed by spatial density analyses. Our data confirm that the Golgi in an interphase mammalian cell is a single, ribbon-like organelle composed of stacks of flattened cisternae punctuated by openings of various sizes [Rambourg, A., Clermont, Y., & Hermo, L. (1979) Am. J. Anat. 154, 455–476]. The data also show that the endoplasmic reticulum (ER) is a single continuous compartment that forms close contacts with mitochondria, multiple trans Golgi cisternae, and compartments of the endo-lysosomal system. This ER traverses the Golgi ribbon from one side to the other via cisternal openings. Microtubules form close, non-random associations with the cis Golgi, the ER, and endo-lysosomal compartments. Despite the dense packing of organelles in this Golgi region, ≈66% of the reconstructed volume is calculated to represent cytoplasmic matrix. We relate the intimacy of structural associations between organelles in the Golgi region, as quantified by spatial density analyses, to biochemical mechanisms for membrane trafficking and organellar communication in mammalian cells.
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We reported previously that the human T-cell lymphotrophic virus type I (HTLV-I)-associated adult T-cell leukemia line HuT-102 produces a cytokine designated interleukin (IL) T that requires interleukin (IL) 2 receptor beta-subunit expression for its action. Using anti-cytokine antibodies, we demonstrated that IL-T is identical to the simultaneously described IL-15. When compared to activated monocytes, IL-15 mRNA expression was 6- to 10-fold greater in HuT-102 cells. The predominant IL-15 message from HuT-102 is a chimeric mRNA joining a segment of the R region of the long terminal repeat of HTLV-I and the 5'-untranslated region (UTR) of IL-15. Normally, by alternative splicing, this 118-nucleotide R element represents the most 5' region of several HTLV-I transcripts including tax, rex, and env. The introduction of the R element eliminated over 200 nucleotides of the IL-15 5'-UTR, including 8 of 10 upstream AUGs that are present in normal IL-15 messages. On analysis of the 5'-UTR of normal IL-15, we demonstrated that the presence of these 10 upstream AUGs interferes with IL-15 mRNA translation. Thus, IL-15 synthesis by the adult T-cell leukemia line HuT- 102 involves an increase in IL-15 mRNA transcription and translation secondary to the production of an HTLV-I R element fusion message that lacks many upstream AUGs.
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Somatic mutation of the variable (V) regions of immunoglobulin genes occurs in vivo at rates that have been estimated to be between 10(-3) and 10(-4) per bp per generation. To study this process in vitro, the 18.81 pre-B-cell line and hybrids derived by fusing 18.81 to the NSO myeloma fusion partner were transfected with a mu heavy-chain construct containing a nonsense mutation in the V region (Vn) or the constant region (Cn). Mutation was quantitated by reversion analysis using the ELISA spot assay to detect single cells secreting IgM. Fluctuation analysis revealed that V-region mutations spontaneously occurred in 18.81 cells at an average rate of 5.8 x 10(-6) per bp per cell generation and in selected 18.81-NSO hybrids at greatly increased rates of 1.6 x 10(-3) to 5.8 x 10(-4) per bp per generation. The Vn construct also reverted frequently in transgenic mice, indicating that it contained sufficient information to mutate at high rates both in vivo and in vitro. Sequence analysis of reverted genes revealed that reversion was due to point mutations. Since the rates and nature of the mutations that are occurring in these transfected genes are similar to those reported in vivo, it should be possible to use this system to identify the cis-acting sequences and trans-acting factors that are responsible for V-region somatic hypermutation.
Resumo:
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