Canard Cycles and Poincar\'e Index of Non-Smooth Vector Fields on the Plane

This paper is concerned with closed orbits of non-smooth vector fields on the plane. For a subclass of non-smooth vector fields we provide necessary and sufficient conditions for the existence of canard kind solutions. By means of a regularization we prove that the canard cycles are singular orbits of singular perturbation problems which are limit periodic sets of a sequence of limit cycles. Moreover, we generalize the Poincar\'e Index for non-smooth vector fields.Comment: 20 pages, 25 figure

15-deoxy-delta(12,14)-prostaglandin J(2) Induces Apoptosis And Upregulates Socs3 In Human Thyroid Cancer Cells

The cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is a natural ligand of peroxisome proliferator-activated receptor gamma (PPAR-gamma) and a potential mediator of apoptosis in cancer cells. In the present study, we evaluated the effect of 15d-PGJ(2) in human thyroid papillary carcinoma cells (TPC-1) using different doses of 15d-PGJ(2) (0.6 to 20 mu M) to determine IC50 (9.3 mu M) via the MTT assay. The supernatant culture medium of the TPC-1 cells that was treated either with 15d-PGJ(2) or with vehicle (control) for 24 hours was assessed for IL-6 secretion via CBA assay. RT-qPCR was used to evaluate mRNA expression of IL-6, SOCS1, SOCS3, and STAT3. TPC-1 cells treated with 15d-PGJ(2) decreased the secretion and expression of IL-6 and STAT3, while it increased SOCS1 and SOCS3. Overall, we demonstrated that 15d-PGJ(2) downregulated IL-6 signaling pathway and led TPC-1 cells into apoptosis. In conclusion, 15d-PGJ(2) shows the potential to become a new therapeutic approach for thyroid tumors

Sex and lifestyle dictate learning performance in a neotropical wasp

In contrast to extensive investigations on bee cognition, the cognitive capacities of wasps remain largely unexplored despite their key role as pollinators and predators of insect pests. Here we studied learning and memory in the neotropical wasp Mischocyttarus cerberus using a Pavlovian conditioning in which harnessed wasps respond with conditioned movements of their mouthparts to a learned odorant. We focused on the different castes, sexes, and ages coexisting within a nest and found that adults of M. cerberus learned and memorized efficiently the odor-sugar associations. In contrast, newly emerged females, but not males, were unable to learn odorants. This difference concurs with their different lifestyle as young males perform regular excursions outside the nest while young females remain in it until older age. Our results thus highlight the importance of socio-ecological constraints on wasp cognition and set the basis for mechanistic studies on learning differences across ages and castes

Influence of the temperature on the carrier capture into self-assembled InAs/GaAs quantum dots

Photoluminescence (PL) spectroscopy and atomic-force microscopy (AFM) were used to investigate the size evolution of InAs quantum dots on GaAs(001) as a function of the amount of InAs material. Different families of islands were observed in the AFM images and unambiguously identified in the PL spectra, together with the signal of the wetting layer. PL measurements carried out at low and intermediate temperatures showed a thermal carrier redistribution among dots belonging to different families. The physical origin of this behavior is explained in terms of the different temperature dependence of the carrier-capture rate into the quantum dots. At high temperatures, an enhancement of the total PL-integrated intensity of the largest-sized quantum dots was attributed to the increase of diffusivity of the photogenerated carriers inside the wetting layer. (C) 2003 American Institute of Physics.931016279628

Chronic administration of Abarema cochliacarpos attenuates colonic inflammation in rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Inflammatory bowel diseases are characterized by a chronic clinical course of relapse and remission associated with self-destructive inflammation of the gastrointestinal tract. Active extracts from plants have emerged as natural potential candidates for its treatment. Abarema cochliacarpos (Gomes) Barneby & Grimes, Fabaceae (Barbatimao), is a native medicinal plant in to Brazil. Previously we have demonstrated in an acute colitis model a marked protective effect of a butanolic extract, so we decided to assess its anti-inflammatory effect in a chronic ulcerative colitis model induced by trinitrobenzensulfonic acid (TNBS). Abarema cochliacarpos (150 mg/day, v.o.) was administered for fourteen consecutive days. This treatment decreased significantly macroscopic damage as compared with TNBS. Histological analysis showed that the extract improved the microscopic structure. Myeloperoxidase activity (MPO) was significantly decreased. Study of cytokines showed that TNF-alpha was diminished and IL-10 level was increased after Abarema cochliacarpos treatment. In order to elucidate inflammatory mechanisms, expression of cyclooxygenase (COX)-2 and nitric oxide synthase (iNOS) were studied showing a significant downregulation. In addition, there was reduction in the JNK and p-38 activation. Finally, I kappa B degradation was blocked by Abarema cochliacarpos treatment being consistent with an up-regulation of the NF-kappaB-binding activity. These results reinforce the anti-inflammatory effects described previously suggesting that Abarema cochliacarpos could provide a source for the search for new anti-inflammatory compounds useful in ulcerative colitis treatment.214680690Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual de Alagoas, BrazilInstituto Federal de Educacao Ciencia e Tecnologia-Sergipe, BrazilCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Structure of the protective nematode protease complex H-gal-GP and its conservation across roundworm parasites

Roundworm parasite infections are a major cause of human and livestock disease worldwide and a threat to global food security. Disease control currently relies on anthelmintic drugs to which roundworms are becoming increasingly resistant. An alternative approach is control by vaccination and ‘hidden antigens’, components of the worm gut not encountered by the infected host, have been exploited to produce Barbervax, the first commercial vaccine for a gut dwelling nematode of any host. Here we present the structure of H-gal-GP, a hidden antigen from Haemonchus contortus, the Barber’s Pole worm, and a major component of Barbervax. We demonstrate its novel architecture, subunit composition and topology, flexibility and heterogeneity using cryo-electron microscopy, mass spectrometry, and modelling. Importantly, we demonstrate that complexes with the same architecture are present in other Strongylid roundworm parasites including human hookworm. This suggests a common ancestry and the potential for development of a unified hidden antigen vaccine

Analysis of student´s proficiency evaluation model for adaptative testing / Analysis of student's proficiency evaluation model for adaptive testing

A evolução da Internet e sua adoção transformou e continua transformando cada vez mais o contexto humano e, a educação, também está inserida nessa situação. Devido a isso, há ferramentas de apoio ao estudante, como sistemas avaliativos online. Apresentaremos nesse trabalho os resultados da simulação de uma avaliação online feita por um aluno com dada proficiência, a fim de coletar todos os dados a respeito do desempenho deste aluno – sua nota final – utilizando a teoria de Resposta ao Item em duas abordagens para cômputo da nota final. Uma primeira abordagem usando a questão subsequente a uma respondida de um nível de dificuldade superior ou inferior dependendo do acerto da questão anterior. E uma segunda usando a questão subsequente a uma respondida de um nível de dificuldade entre a anterior e a do limite máximo ou mínimo dependendo do acerto da questão anterior. Foram analisados resultados de simulação para diferentes tamanhos de provas e para diferentes proficiências dos respondentes simulados. Após análise multivariada de clusterização dos resultados por K-means, verifica-se que ambas as abordagens são subótimas para situações diferentes de tamanhos de prova na busca da nota final mais próxima da proficiência simulada

Stem cell factor and its soluble receptor (c-kit) in serum of asthmatic patients- correlation with disease severity

<p>Abstract</p> <p>Background</p> <p>SCF (stem cell factor) is a pleiotropic cytokine exerting its role at different stages of bone marrow development and affecting eosinophil activation, mast cells and basophil chemotaxis and survival. The aim of the study was to assess concentration of SCF and its soluble receptor c-kit (sc-kit) in peripheral blood of patients with asthma referring it to asthma severity and phenotype.</p> <p>Methods</p> <p>The study involved 107 patients with bronchial asthma, well characterized with respect to severity and 21 healthy controls. Concentration of SCF and sc-kit in the patients serum were measured by ELISA method.</p> <p>Results</p> <p>Mean serum SCF level in the group of asthmatics (n = 88) was significantly higher as compared to healthy controls (1010 pg/ml ± 37 vs 799 ± 33; p < 0,001). The level of SCF was higher in patients with severe asthma as compared to patients with non-severe asthma (1054 +/- 41 pg/ml vs 819 +/- 50; p < 0,01) and correlated with dose of inhaled glucocorticosteroids taken by the patients to achieve asthma control (R = 0,28; p < 0,01). The mean sc-kit serum level did not differ between asthmatic patients and healthy controls, however the level of sc-kit in non-severe asthmatics was significantly higher as compared to patients with severe asthma and healthy controls. In asthmatic patients (n = 63) the level of sc-kit correlated positively with FEV1% predicted value (R = 0,45; p < 0,001) and MEF25% predicted value (R = 0,33; p < 0,01). The level of sc-kit inversely correlated with the dose of inhaled glucocorticosteroids taken by the patients (R = -0,26; p < 0,01).</p> <p>Conclusion</p> <p>Serum levels of SCF and its soluble receptor c-kit seem to be reflect asthma severity suggesting a role for these molecules in asthmatic inflammation.</p

Predictive Demand Service for Public Transit Using CNN/ Atendimento Preditivo de Demanda do Transporte Público Coletivo Usando CNN

Several cities in Brazil undergo a territorial expansion and inhabitants constantly, this process is called urbanization. An uncontrolled urbanization generates many difficulties, highlighting the mobility of public transport, since many citizens depend on this mobility, we have, for example, public transport in Goiânia, which directly affects the living conditions of passengers. For your foreknowledge, a model capable of mirroring the performance of your demand is essential, providing that the system meets users in an acceptable way. A two-dimensional CNN is a CNN model that has a hidden convolutional layer that operates on a 1D sequence, it is a convenient mechanism to simulate a univariate forecast of time series of the predictive service of Goiânia's public transport. The method is equivalent to an analysis of the focal parts that make up the public transport system and how to represent it in the 1D convolutional neural network. Actual data of the systems and their results were compared to those expected, showing the model's effectiveness. This work manifests a forecast of the demand for public transport in Goiânia, to make it susceptible to users of the system.