Feature and Region Selection for Visual Learning

Visual learning problems such as object classification and action recognition are typically approached using extensions of the popular bag-of-words (BoW) model. Despite its great success, it is unclear what visual features the BoW model is learning: Which regions in the image or video are used to discriminate among classes? Which are the most discriminative visual words? Answering these questions is fundamental for understanding existing BoW models and inspiring better models for visual recognition. To answer these questions, this paper presents a method for feature selection and region selection in the visual BoW model. This allows for an intermediate visualization of the features and regions that are important for visual learning. The main idea is to assign latent weights to the features or regions, and jointly optimize these latent variables with the parameters of a classifier (e.g., support vector machine). There are four main benefits of our approach: (1) Our approach accommodates non-linear additive kernels such as the popular $\chi^2$ and intersection kernel; (2) our approach is able to handle both regions in images and spatio-temporal regions in videos in a unified way; (3) the feature selection problem is convex, and both problems can be solved using a scalable reduced gradient method; (4) we point out strong connections with multiple kernel learning and multiple instance learning approaches. Experimental results in the PASCAL VOC 2007, MSR Action Dataset II and YouTube illustrate the benefits of our approach

Molecular basis for class V beta-tubulin effects on microtubule assembly and paclitaxel resistance.

Vertebrates produce at least seven distinct beta-tubulin isotypes that coassemble into all cellular microtubules. The functional differences among these tubulin isoforms are largely unknown, but recent studies indicate that tubulin composition can affect microtubule properties and cellular microtubule-dependent behavior. One of the isotypes whose incorporation causes the largest change in microtubule assembly is beta5-tubulin. Overexpression of this isotype can almost completely destroy the microtubule network, yet it appears to be required in smaller amounts for normal mitotic progression. Moderate levels of overexpression can also confer paclitaxel resistance. Experiments using chimeric constructs and site-directed mutagenesis now indicate that the hypervariable C-terminal region of beta5 plays no role in these phenotypes. Instead, we demonstrate that two residues found in beta5 (Ser-239 and Ser-365) are each sufficient to inhibit microtubule assembly and confer paclitaxel resistance when introduced into beta1-tubulin; yet the single mutation of residue Ser-239 in beta5 eliminates its ability to confer these phenotypes. Despite the high degree of conservation among beta-tubulin isotypes, mutations affecting residue 365 demonstrate that amino acid substitutions can be context sensitive; i.e. an amino acid change in one isotype will not necessarily produce the same phenotype when introduced into a different isotype. Modeling studies indicate that residue Cys-239 of beta1-tubulin is close to a highly conserved Cys-354 residue suggesting the possibility that disulfide formation could play a significant role in the stability of microtubules formed with beta1- but not with beta5-tubulin

UM ESTUDO DE CASO SOBRE A QUALIDADE DE VIDA NO TRABALHO DE UMA INSTITUIÇÃO DE ENSINO SUPERIOR DE FLORIANÓPOLIS

O presente artigo tem como intuito entender o que os colaboradores de uma instituição de ensino superior entendem como qualidade de vida no trabalho (QVT), imposto que ela propicia uma colaboração maior por parte dos subordinados, desta forma cria uma integração entre os superiores, colegas de trabalho e o ambiente em si, buscando sempre sanar as necessidades dos colaboradores. Com o intuito de entender a percepção da qualidade para as pessoas, foi determinado como problema de pesquisa: qual a percepção dos colaboradores em relação à qualidade de vida no trabalho? E para tentar entender melhor o estudo foi proposto como objetivo específicos: aplicação de um questionário aos funcionários; compreender quais aspectos na opinião dos colaboradores prejudicam a qualidade de vida e identificar quais são os elementos que a organização precisa observar para atender a qualidade de vida no trabalho. Para isso, o presente artigo utiliza a metodologia de natureza aplicada, composta de maneira mista: qualitativa e quantitativa, de caráter exploratório e descritivo. Tendo como principais resultados a necessidade de se suprir os fatores higiênicos, visto que são evitam o processo de desmotivação

Human mutations that confer paclitaxel resistance.

The involvement of tubulin mutations as a cause of clinical drug resistance has been intensely debated in recent years. In the studies described here, we used transfection to test whether beta1-tubulin mutations and polymorphisms found in cancer patients are able to confer resistance to drugs that target microtubules. Three of four mutations (A185T, A248V, R306C, but not G437S) that we tested caused paclitaxel resistance, as indicated by the following observations: (a) essentially 100% of cells selected in paclitaxel contained transfected mutant tubulin; (b) paclitaxel resistance could be turned off using tetracycline to turn off transgene expression; (c) paclitaxel resistance increased as mutant tubulin production increased. All the paclitaxel resistance mutations disrupted microtubule assembly, conferred increased sensitivity to microtubule-disruptive drugs, and produced defects in mitosis. The results are consistent with a mechanism in which tubulin mutations alter microtubule stability in a way that counteracts drug action. These studies show that human tumor cells can acquire spontaneous mutations in beta1-tubulin that cause resistance to paclitaxel, and suggest that patients with some polymorphisms in beta1-tubulin may require higher drug concentrations for effective therapy

Intraoperative rupture in the aneurysmal neck: suggestion for surgical management

The per operative rupture of the aneurysm during dissection impairs the delicate microsurgical procedure and increases the risk of a bad evolution for the patient. During operation the aneurysm generally ruptures in its belly but it could happen just in its colon, between the main vessel and the sac. This brings a serious problem to the neurosurgeon once the placement of a clip at this place will increase the bleeding. Our technical suggestion is to perform the clipage over a small piece of temporal muscle gently placed over the hole of bleeding after temporary clipage. This is a very simple procedure but very useful that must be reminded in such cases. We did not found a similar description in the main books and articles related with intraoperative aneurysm rupture.A ruptura aneurismática intraoperatória de um aneurisma intracraniano pode comprometer dramaticamente um procedimento neurocirúrgico delicado, diminuindo as chances de uma evolução favorável do paciente. A ruptura ordinariamente se dá junto ao domus do aneurisma, causando icto.Com menor frequência, a ruptura pode se processar junto ao colo, em um ponto entre o vaso principal e o saco aneurismático. Isso causa um grande problema ao neurocirurgião; a colocação de um clipe de aneurisma neste local só irá aumentar a hemorragia. Nossa sugestão técnica resume-se à clipagem do aneurisma sobre um pequeno fragmento de músculo temporal colocado no local da ruptura. É bastante simples mas bastante útil, devendo ser lembrada no momento da ruptura. Não encontramos descrição semelhante nos principais livros e artigos que se referem à ruptura aneurismática durante a cirurgia.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Neurologia e NeurocirurgiaUNIFESP, EPM, Depto. de Neurologia e NeurocirurgiaSciEL

Influencia do campo magnetico sobre uma amostra de cristal liquido nematico torcida

Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e MatematicasAs moléculas de cristais líquidos nemáticos podem ser orientadas paralelamente às superfícies de contato e orientação de duas placas paralelas pode ser tal que o cristal líquido nemático entre elas sofra uma torção uniforme. O presente trabalho discute a influência do campo magnético ou elétrico perpendicular às placas sobre esta estrutura. As equações que determinam a orientação molecular como função do campo aplicado são resolvidas para o caso k11 = k22 = k33. Até o campo magnético atingir um valor crítico. não ocorre distorcão no padrão de orientação. Após este valor crítico, a torção deixa de ser uniforme. Os resultados para a orientação foram inesperados, as moléculas tendem a se orientar paralelamente ao campo aplicado a medida que sofrem uma torção. Para altos valores do campo, a orientação molecular é praticamente constante em cada metade da amostra, mas entre um lado e outro do plano de simetria da amostra, as projeções do eixo molecular no plano perpendicular ao campo externo formam um ângulo próximo de noventa graus. Apresentamos gráficos para os ângulos q e f como função do campo reduzido, para torção inicial de noventa graus, pois este é o caso de maior interesse prático. Os resultados teóricos concordam qualitativamente com dados experimentais obtidos em várias experiências

Reduction of liver abscesses in feedlot cattle by the addition of tannins on diet

Liver abscess is a common disorder of feedlot cattle developed usually after ruminal acidosis. Despite of this condition is generally asymptomatic, it causes economic losses due to the reduction of feed efficiency. Routinely, antibiotics have been used as growth promoters, which can control ruminal acidosis. However, these have not direct effect on liver abscess and their use in the food chain has been under revision because of the concern about the development of antibiotic resistance. Thus, the need of alternatives increases. Tannins have been used for growth promotion in fattening of cattle, but they have not been evaluated for controlling liver disease. The aim of this study was to evaluate the effect of plant-based tannins on the prevalence of liver abscess in feedlot cattle. Two groups of Angus heifers were fattened under regular feedlot conditions; one received the regular feed (control group (CG), n=237 cows) with monensin (40 g/tn of Dry Matter (DM)) as growth promoter. Feed of the other group (tannin’s group (TG), n=258 animals) was added with a commercial blend of tannins (2500 g/tn DM). Animals stayed in the feedlot until fattening was finished, and were sacrificed in the slaughterhouse. Presence of liver abscess was evaluated at the postmortem inspection. Additionally, one sample of the right lobe of healthy liver was collected for histopathologic examination of in approximately 20% of cows from both groups (69 from TG and 66 from CG). Macro and microscopic abscess development were compared by Fischer’s Exact Test. A numeric score of microscopic changes was used and differences in microscopic liver affection between groups were evaluated with the Mann- Whitney test. Differences for all statistics were considered significant when p<0.05. Three animals from TG and 14 from CG showed abscesses, being this difference significant (p=0.0051). Microscopically, there was no difference since 35 animals from TG and 33 from CG showed microscopic abscess (p=1). Finally, there were no differences in microscopic scores from both groups (p=0.7452). The obtained results suggested that the tannin treatment is effective in controlling the development of liver abscess. However, presence of microscopic lesions in cows from TG suggested that the treatment regulated their progression but not the colonization of liver by the infectious agents. Nevertheless, the mechanisms involved are unknown and should be determined in further studies.El desarrollo de abscesos hepáticos es frecuente en bovinos en engorde intensivo como consecuencia de acidosis ruminal. Tal condición suele ser asintomática, pero genera pérdidas económicas. Ciertos antibióticos se utilizan frecuentemente como promotores del crecimiento, colaborando en el control de la acidosis. Sin embargo, su uso en producción animal es cuestionado debido al riesgo de generar resistencia en microorganismos, requiriéndose por lo tanto de productos alternativos. Además, estos no tienen efecto sobre los abscesos hepáticos. Los taninos son productos vegetales utilizados como promotores de crecimiento en engorde de bovinos y no han sido evaluados como herramienta para prevenir la aparición de abscesos. El objetivo del presente trabajo fue evaluar el efecto de taninos vegetales sobre el desarrollo de abscesos hepáticos en bovinos de feedlot. Dos grupos de vaquillonas cruza Angus fueron alimentadas con una dieta habitualmente empleada en engorde a corral; un grupo (grupo control (CG), n=237 animales) recibió monensina como promotor de crecimiento (40 g/t materia seca (MS)). El otro grupo (Grupo Taninos (TG), n=258 animales) recibió una mezcla comercial de taninos (2500 g/t MS). Una vez finalizada la terminación los animales fueron sacrificados en frigorífico, en donde se determinó la presencia de abscesos hepáticos. Una muestra del lóbulo derecho fue recolectada para estudio histopatológico en aproximadamente el 20% de los animales sin cambios macroscópicos de cada grupo (69 de TG y 66 de CG). La presencia de abscesos macro y microscópicos en ambos grupos fue comparada mediante el Test Exacto de Fischer. El grado de afección microscópica entre grupos fue evaluado mediante la prueba de Mann Whitney. Las diferencias fueron consideradas estadísticamente significativas cuando se obtuviera un valor de p<0,05. Tres bovinos de TG y 14 de CG mostraron abscesos a la inspección macroscópica, esta diferencia fue significativa (p=0,0051). Microscopicamente no hubo diferencias ya que 35 animales de TG y 33 de CG mostraron lesiones (p=1). No se encontraron diferencias en la gravedad de las lesiones entre ambos grupos (p=0,7452). Los resultados obtenidos indicaron que el tratamiento con taninos fue efectivo en el control de abscesos hepáticos. La presencia de lesiones microscópicas en bovinos del TG sugirió que el tratamiento controla la progresión del cuadro, pero no la colonización del agente causal. Los mecanismos implicados permanecen desconocidos y deberán analizarse en futuros estudios.Instituto de PatobiologíaFil: Cabral, C. Silvateam, Indunor S.A.; ArgentinaFil: Redondo, Enzo Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delgado, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Catedra de Patología Animal; Argentin