1,735 research outputs found

    Final evolutions of a class of May-Leonard Lotka-Volterra systems

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    We study a particular class of Lotka-Volterra 3-dimensional systems called May-Leonard systems, which depend on two real parameters a and b, when a + b = −1. For these values of the parameters we shall describe its global dynamics in the compactification of the non-negative octant of ℝ3 including its infinity. This can be done because this differential system possesses a Darboux invariant

    Precipitation reaction in alpha-Cu-Al-Ag alloys

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    The Ag-rich precipitates formation reaction in the Cu-9.22%at. Al-4.66%at. Ag, Cu-9.31%at. Al-5.83%at. Ag and Cu-9.37%at. Al-7.08%at. Ag alloys was studied using microhardness change measurements with temperature and time, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The results indicated that the Ag-rich phase formation is an interface controlled process with a zero-order mechanism, due to the amount of unsolved Ag that makes the precipitation reaction rate independent of Ag concentration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNIFESP Departamento de Ciências Exatas e da TerraUNESP Instituto de Química Departamento de Físico-QuímicaUNIFESP, Depto. de Ciências Exatas e da TerraSciEL

    Feature Extraction and Classification of Biosignals - Emotion Valence Detection from EEG Signals

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    In thisworkavalencerecognitionsystembasedonelectroencephalogramsispresented.Theperformanceof the systemisevaluatedfortwosettings:singlesubjects(intra-subject)andbetweensubjects(inter-subject). The featureextractionisbasedonmeasuresofrelativeenergiescomputedinshorttimeintervalsandcertain frequencybands.Thefeatureextractionisperformedeitheronsignalsaveragedoveranensembleoftrialsor on single-trialresponsesignals.Thesubsequentclassificationstageisbasedonanensembleclassifier,i.e.a random forestoftreeclassifiers.Theclassificationisperformedconsideringtheensembleaverageresponsesof all subjects(inter-subject)orconsideringthesingle-trialresponsesofsinglesubjects(intra-subject).Applying a properimportancemeasureoftheclassifier,featureeliminationhasbeenusedtoidentifythemostrelevant features of the decision making.info:eu-repo/semantics/publishedVersio

    Investigating Antifungal Susceptibility in Candida Species With MALDI-TOF MS-Based Assays.

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    Half of invasive fungal infections lead to death. Amongst pathogenic fungi, the most widespread species belong to the Candida genus and vary in their susceptibility to antifungal drugs. The emergence of antifungal resistance has become a major clinical problem. Therefore, the definition of susceptibility patterns is crucial for the survival of patients and the monitoring of resistance epidemiology. Although, most routinely used methods of AntiFungal Susceptibility Testing (AFST) have reached their limits, the rediscovery of Matrix Associated Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) in the field of mycology provides a promising alternative for the study of antifungal resistance. MALDI-TOF MS is already used in mycology for fungal identification, which permits to highlight inherent antifungal resistance. However, the main concern of clinicians is the rise of acquired antifungal resistance and the time needed for their detection. For this purpose, MALDI-TOF MS has been shown to be an accurate tool for AFST, presenting numerous advantages in comparison to commonly used techniques. Finally, MALDI-TOF MS could be used directly to detect resistance mechanisms through typing. Consequently, MALDI-TOF MS offers new perspectives in the context of healthcare associated outbreaks of emerging multi-drug resistant fungi, such as C. auris. As a proof of concept, we will illustrate the current and future benefits in using and adapting MALDI-TOF MS-based assays to define the susceptibility pattern of C. auris, by species identification, AFST, and typing

    Uso da fish em mucosa oral para investigação de mosaicismo com linhagem 45,x: estudo com homens saudáveis e pacientes com distúrbios da diferenciação do sexo

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOObjective: To verify whether fluorescence in situ hybridization (FISH) of cells from the buccal epithelium could be employed to detect cryptomosaicism with a 45,X lineage in 46,XY patients. Subjects and methods: Samples of nineteen 46,XY healthy young men and five patients with disorders of sex development (DSD), four 45,X/46,XY and one 46,XY were used. FISH analysis with X and Y specific probes on interphase nuclei from blood lymphocytes and buccal epithelium were analyzed to investigate the proportion of nuclei containing only the signal of the X chromosome. Results: The frequency of nuclei containing only the X signal in the two tissues of healthy men did not differ (p = 0.69). In all patients with DSD this frequency was significantly higher, and there was no difference between the two tissues (p = 0.38), either. Conclusions: Investigation of mosaicism with a 45,X cell line in patients with 46,XY DSD or sterility can be done by FISH directly using cells from the buccal epithelium. © ABE&M todos os direitos reservados.To verify whether fluorescence in situ hybridization (FISH) of cells from the buccal epithelium could be employed to detect cryptomosaicism with a 45,X lineage in 46,XY patients. Subjects and methods: Samples of nineteen 46,XY healthy young men and five patients with disorders of sex development (DSD), four 45,X/46,XY and one 46,XY were used. FISH analysis with X and Y specific probes on interphase nuclei from blood lymphocytes and buccal epithelium were analyzed to investigate the proportion of nuclei containing only the signal of the X chromosome. Results: The frequency of nuclei containing only the X signal in the two tissues of healthy men did not differ (p = 0.69). In all patients with DSD this frequency was significantly higher, and there was no difference between the two tissues (p = 0.38), either. Conclusions: Investigation of mosaicism with a 45,X cell line in patients with 46,XY DSD or sterility can be done by FISH directly using cells from the buccal epithelium584328334FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2011/50189-7Verificar se a hibridização in situ por fluorescência (FISH) em células de mucosa oral poderia ser empregada para detectar criptomosaicismo com linhagem 45,X em pacientes 46,XY. Sujeitos e métodos: Amostra de 19 jovens saudáveis 46,XY e cinco pacientes com distúrbios da diferenciação do sexo (DDS), quatro 45,X/46,XY e um 46,XY. FISH com sondas específicas para X e Y em núcleos interfásicos de linfócitos e mucosa oral para investigar aproporção de núcleos contendo apenas o sinal do cromossomo X. Resultados: A frequência de núcleos contendo apenas o sinal do X nos dois tecidos dos homens saudáveis não diferiu (p =0,69). Em todos os pacientes com DDS essa frequência foi significativamente maior, e tambémnão houve diferença entre os dois tecidos (p = 0,38). Conclusões: A investigação de mosaicismo com linhagem 45,X em pacientes com DDS 46,XY ou esterilidade pode ser feita por FISHdiretamente em células de mucosa ora

    Essential oil from Ageratum fastigiatum reduces expression of the pro-inflammatory cytokine tumor necrosis factor-alpha in peripheral blood leukocytes subjected to in vitro stimulation with phorbol myristate acetate

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    AbstractAgeratum fastigiatum (Gardner) R.M. King & H. Rob., a member of the Asteraceae family popularly known in Brazil as “matapasto”, is indicated in folk medicine as anti-inflammatory and analgesic. Despite its popular use, little is known about its potential effect on the parameters involved in an inflammatory response. The objective of this study was to characterize the chemical composition of the essential oil from A. fastigiatum and to evaluate the frequency of tumor necrosis factor alpha and interferon gamma producing cells in peripheral blood lymphocytes stimulated with phorbol myristate acetate in the presence of essential oil from A. fastigiatum. Non-toxic concentrations of essential oil from A. fastigiatum were evaluated in cultures of peripheral blood leucocytes using the trypan blue exclusion assay by flow cytometry. GC–MS analysis revealed that the prevalent compounds identified in the essential oil from A. fastigiatum sample were α-pinene, limonene, trans-caryophyllene, α-humulene, caryophyllene oxide, 1,2-humulene-epoxide, 1,6-humulanodien-3-ol, and α-cadinol. Results showed that exposure to essential oil from A. fastigiatum at concentrations of 0.5×10−2 and 1×10−2μl/ml caused no alterations in leukocyte viability as compared to the control group. Both concentrations lowered the percentage of tumor necrosis factor alpha (+)-lymphocytes and neutrophils. There were no changes in the percentage of lymphocytes positive for the interferon gamma cytokine. Our results suggest that part of the anti-inflammatory activity attributed to A. fastigiatum may be due to the effect of some of its components in decreasing the number of cells that produce the pro-inflammatory cytokine tumor necrosis factor alpha

    ERP correlates of error processing during performance on the HalsteadCategory Test

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    The Halstead Category Test (HCT) is a neuropsychological test that measures a person's ability to formulate and apply abstract principles. Performance must be adjusted based on feedback after each trial and errors are common until the underlying rules are discovered. Event-related potential (ERP) studies associated with the HCT are lacking. This paper demonstrates the use of amethodology inspired on Singular SpectrumAnalysis (SSA) applied to EEG signals, to remove high amplitude ocular andmovement artifacts during performance on the test. This filtering technique introduces no phase or latency distortions, with minimum loss of relevant EEG information. Importantly, the test was applied in its original clinical format, without introducing adaptations to ERP recordings. After signal treatment, the feedback-related negativity (FRN) wave, which is related to error-processing, was identified. This component peaked around 250ms, after feedback, in fronto-central electrodes. As expected, errors elicited more negative amplitudes than correct responses. Results are discussed in terms of the increased clinical potential that coupling ERP informationwith behavioral performance data can bring to the specificity of theHCT in diagnosing different types of impairment in frontal brain function.info:eu-repo/semantics/publishedVersio

    Amerindian genetic ancestry and INDEL polymorphisms associated with susceptibility of childhood B-cell Leukemia in an admixed population from the Brazilian Amazon

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    AbstractAcute lymphoblastic leukemia (ALL) is a malignant tumor common in children. Studies of genetic susceptibility to cancer using biallelic insertion/deletion (INDEL) type polymorphisms associated with cancer development pathways may help to clarify etymology of ALL. In this study, we investigate the role of eight functional INDEL polymorphisms and influence of genetic ancestry to B-cell ALL susceptibility in children of Brazilian Amazon population, which has a high degree of inter-ethnic admixture. Ancestry analysis was estimated using a panel of 48 autosomal ancestry informative markers. 130 B-cell ALL patients and 125 healthy controls were included in this study. The odds ratios and 95% confidence intervals were adjusted for confounders. The results indicated an association between the investigated INDEL polymorphisms in CASP8 (rs3834129), CYP19A1 (rs11575899) e XRCC1 (rs3213239) genes in the development of B-cell ALL. The carriers of Insertion/Insertion (Ins/Ins) genotype of the polymorphism in CASP8 gene presented reduced chances of developing B-cell ALL (P=0.001; OR=0.353; 95% CI=0.192–0.651). The Deletion/Deletion (Del/Del) genotype of the polymorphism in CYP19A1 gene was associated to a lower chance of developing B-cell ALL (P=3.35×10−6; OR=0.121; 95% CI=0.050–0.295), while Del/Del genotype of the polymorphism in XRCC1 gene was associated to a higher chance of developing B-cell ALL (P=2.01×10−4; OR=6.559; 95% CI=2.433–17.681). We also found that Amerindian ancestry correlates with the risk of B-cell ALL. For each increase of 10% in the Amerindian ancestry results in 1.4-fold chances of developing B-cell ALL (OR=1.406; 95% IC=1.123–1.761), while each increase of 10% in the European ancestry presents a protection effect in the development of B-cell ALL (OR=0.666; 95% IC=0.536–0.827). The results suggest that genetic factors influence leukemogenesis and might be explored in the stratification of B-cell ALL risk in admixed populations

    Pisolithus arhizus (Scop.) Rauschert improves growth of adventitious roots and acclimatization of in vitro regenerated plantlets of Pinus pinea L.

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    Stone pine (Pinus pinea L.) is an economically important forest tree in the Mediterranean region and has been the target of breeding and selection through micropropagation mainly for its ecological and ornamental aspects. A crucial step in micropropagation is adventitious rooting of microshoots, which often is highly inefficient in most conifer species including stone pine. Hence, we conducted in vitro co-culture of Pinus pinea microshoots with the ectomycorrhizal fungus Pisolithus arhizus (isolated from natural stands) in order to promote adventitious root growth and plant survival during acclimatization. Significant differences were found in the number of branches, in the number of roots plus branches, in total length of roots, in total length of roots plus branches, in average root length and in the length of the longest root in inoculated plants during in vitro rooting compared with non-inoculated plants. The roots of inoculated plants also grew better in vermiculite and during acclimatization in a mixed substrate compared with roots of control plants resulting in the development of vigorous root system. Overall, mycorrhizal inoculation increased the survival rate of the regenerated pine
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