Associação Brasileira de Estatística
Repositório da Produção USP (Univ. de São Paulo)Not a member yet
45573 research outputs found
Sort by
Intervenções andrógicas de educação matemática no contexto de um banco comunitário
No full textEste artigo refere-se à continuação de um trabalho em Educação Matemática no contexto de um Banco Comunitário (BC) e tem por finalidade abordar o processo de ensino e aprendizagem de matemática de forma contextualizada visando propiciar uma maior autonomia por parte das colaboradoras do BC frente às tarefas por elas desenvolvidas e considerando o contexto sociocultural no qual estão inseridas. O foco é para as intervenções andragógicas de Educação Matemática como um projeto capaz de agregar uma série de iniciativas e possibilitar conhecimentos matemáticos necessários aos membros do BC. A metodologia de investigação segue uma abordagem qualitativa caracterizada como estudo de caso. Como resultado, notou-se maior autonomia por parte das colaboradoras do BC que buscaram se articular com outros empreendimentos do território a fim de divulgar e utilizar a moeda social, com o propósito de fomentar e praticar o desenvolvimento político/social/econômico.Pró-reitoria de Graduação da Universidade de São Paulo (Programa Unificado de Bolsas de Estudos - Pesquisa)MEC Proext/2001
A utilização de software em nuvem para o cálculo de notas e frequências
No full textEsta oficina propõe a elaboração de planilhas para o cálculo de notas e frequências de alunos. As atividades desta oficina trabalharão temas como construção de tabelas, cálculos de notas e frequências, dentre outras ferramentas básicas do software. Serão utilizadas planilhas do Google Drive. Com a utilização deste recurso, o participante poderá ter acesso mais rápido ao material que necessita controlar, editando pelo celular ou computador. Essas situações propiciam uma aquisição de conhecimentos sobre as ferramentas básicas da planilha e ajuda a facilitar as atividades dos participantes, economizando tempo para ser utilizado em outras atividades ou tarefas inerentes ao trabalho escolar. Serão oferecidas 20 vagas, limitadas à capacidade da sala e quantidade de computadores.Programa Institucional de Bolsa de Iniciação à Docência PIBID/CAPE
BioDSL: a domain-specific language for mapping and dissemination of biodiversity data in the LOD
No full textCurrently, Linked Open Data (LOD) have enabled integrated data sharing across disciplines over the Web. However, for LOD users, in areas such as biodiversity (which massively use the Web to disseminate data), the task of transforming data file contents in CSV (Comma Separated Value) to RDF (Resource Description Framework) is not trivial. We have developed a new approach to map data files in CSV to RDF format based on a domain-specific language (DSL) called BioDSL. Using it, biodiversity data users can write compact programs to map their data to RDF and link them to the LOD. Biodiversity vocabularies and ontologies, such as Darwin Core and OntoBio, can be used with BioDSL to enrich user data. Existing tools are exclusively focused on mapping (CSV to RDF), offering little or no support for linking data to the LOD (interconnecting user entities to LOD entities). They also are more complex to use than BioDSL.ICMC-USPLIS-INPACAPES (The National Council for the Improvement of Higher Education - Brazil
State-space modeling and offline evolutive parameter estimation of a generic robotic platform
No full textThis article describes the modeling of a generic robotic platform in state-space representation. The robot's model includes the entire system from robot kinematics and dynamics to the motor plant. The model is then applied to a 4-wheeled holonomic robot according to RoboCup's Small Size Category and validated in parallel with an offline parameter estimation algorithm. The estimation algorithm is a Genetic Algorithm that allows estimation of any parameters in the proposed model with the same simple experiment setting for all of them. The experiments performed show that the proposed method allows estimation within an acceptable error range demonstrating its efficiency by facilitating the modeling of mobile robots without need of complex or various laboratory experiment settings and complex mathematical approaches
Competitive males have higher quality sperm in a monogamous social bee
No full textAbstract\ud
\ud
Background\ud
Reproductive success is determined by the interplay between mating and fertilization success. In social insect species with male-biased sex ratios and queen monogamy, males face particularly strong pre-copulatory sexual selection since they must compete with thousands of other males for a unique mating opportunity. Ejaculate quality is also expected to be under selection, because queens are long-lived and store sperm for life, so males with higher quality ejaculates are expected to provide queens with larger and longer-lived colonies, which in turn may produce more daughter queens (the only direct fitness gains of haplodiploid males). Considering the action of pre and post-copulatory sexual selection on male traits, three scenarios might thus be expected: positive, negative or no association between male mating ability and fertilization success. Here we explored these scenarios in the stingless bee Scaptotrigona aff. depilis, where males gather in large aggregations and queens mate with a single male. Male mating ability was assessed through the capacity of a male to reach an aggregation and persist on it; while sperm viability, sperm number, and sperm morphology were used as proxies for sperm quality.\ud
\ud
\ud
Results\ud
Sperm viability was associated with persistence time in the aggregation, and males that persisted longer presented shorter spermatozoa and higher variation in sperm length than recently arrived males. However, sperm traits of males that reached aggregations did not differ from those of males collected inside their colonies. In addition, males that persisted longer in aggregations were smaller than other males. Male size and sperm viability were not correlated, suggesting that the observed patterns were not due to trade-offs in male resource allocation.\ud
\ud
\ud
Conclusions\ud
Persistence in male aggregations thus seems to select more competitive males with higher quality sperm. Our work is the first one to reveal an association between male competitive ability and fertilization success in a monogamous social insect. This finding sheds important light on the evolution of male traits in social insects and the general mechanisms of sexual selection.Funding was provided by Coordenação de Aperfeiçoamento de Pessoal de\ud
Nível Superior, and Conselho Nacional de Desenvolvimento Científico e\ud
Tecnológico (RJ: CNPq 478982/2013-5)
Using network dynamic fMRI for detection of epileptogenic foci
No full textAbstract
Background
Epilepsy is one of the most prevalent neurological disorders. It remains medically intractable for about one-third of patients with focal epilepsy, for whom precise localization of the epileptogenic zone responsible for seizure initiation may be critical for successful surgery. Existing fMRI literature points to widespread network disturbances in functional connectivity. Per previous scalp and intracranial EEG studies and consistent with excessive local synchronization during interictal discharges, we hypothesized that, relative to same regions in healthy controls, epileptogenic foci would exhibit less chaotic dynamics, identifiable via entropic analyses of resting state fMRI time series.
Methods
In order to first validate this hypothesis on a cohort of patients with known ground truth, here we test individuals with well-defined epileptogenic foci (left mesial temporal lobe epilepsy). We analyzed voxel-wise resting-state fMRI time-series using the autocorrelation function (ACF), an entropic measure of regulation and feedback, and performed follow-up seed-to-voxel functional connectivity analysis. Disruptions in connectivity of the region exhibiting abnormal dynamics were examined in relation to duration of epilepsy and patients’ cognitive performance using a delayed verbal memory recall task.
Results
ACF analysis revealed constrained (less chaotic) functional dynamics in left temporal lobe epilepsy patients, primarily localized to ipsilateral temporal pole, proximal to presumed focal points. Autocorrelation decay rates differentiated, with 100 % accuracy, between patients and healthy controls on a subject-by-subject basis within a leave-one-subject out classification framework. Regions identified via ACF analysis formed a less efficient network in patients, as compared to controls. Constrained dynamics were linked with locally increased and long-range decreased connectivity that, in turn, correlated significantly with impaired memory (local left temporal connectivity) and epilepsy duration (left temporal – posterior cingulate cortex connectivity).
Conclusions
Our current results suggest that data driven functional MRI methods that target network dynamics hold promise in providing clinically valuable tools for identification of epileptic regions
Shape, colour plasticity, and habitat use indicate morph-specific camouflage strategies in a marine shrimp
No full textAbstract\ud
\ud
Background\ud
Colour and shape polymorphisms are important features of many species and may allow individuals to exploit a wider array of habitats, including through behavioural differences among morphs. In addition, differences among individuals in behaviour and morphology may reflect different strategies, for example utilising different approaches to camouflage. Hippolyte obliquimanus is a small shrimp species inhabiting different shallow-water vegetated habitats. Populations comprise two main morphs: homogeneous shrimp of variable colour (H) and transparent individuals with coloured stripes (ST). These morphs follow different distribution patterns between their main algal habitats; the brown weed Sargassum furcatum and the pink-red weed Galaxaura marginata. In this study, we first investigated morph-specific colour change and habitat selection, as mechanisms underlying camouflage and spatial distribution patterns in nature. Then, we examined habitat fidelity, mobility, and morphological traits, further indicating patterns of habitat use.\ud
\ud
\ud
Results\ud
H shrimp are capable of changing colour in just a few days towards their algal background, achieving better concealment in the more marginal, and less preferred, red weed habitat. Furthermore, laboratory trials showed that habitat fidelity is higher for H shrimp, whereas swimming activity is higher for the ST morph, aligned to morphological evidence indicating these two morphs comprise a more benthic (H) and a more pelagic (ST) life-style, respectively.\ud
\ud
\ud
Conclusions\ud
Results suggest that H shrimp utilise a camouflage strategy specialised to a limited number of backgrounds at any one time, whereas ST individuals comprise a phenotype with more generalist camouflage (transparency) linked to a more generalist background utilisation. The coexistence within a population of distinct morphotypes with apparently alternative strategies of habitat use and camouflage may reflect differential responses to substantial seasonal changes in macroalgal cover. Our findings also demonstrate how colour change, behaviour, morphology, and background use all interact in achieving camouflage.This work was supported by the Fundação de Amparo à Pesquisa do Estado\ud
de São Paulo - FAPESP (2009/06675-4 and 2012/17003-0), which granted a\ud
master and a PhD fellowship to RCD and a visiting professor grant to MS\ud
(#2015/22258-5). This is a contribution of the Research Centre for Marine\ud
Biodiversity of the University of São Paulo (NP‐Biomar / USP)
Latin American Study of Nutrition and Health (ELANS): rationale and study design
No full textAbstract\ud
\ud
Background\ud
Obesity is growing at an alarming rate in Latin America. Lifestyle behaviours such as physical activity and dietary intake have been largely associated with obesity in many countries; however studies that combine nutrition and physical activity assessment in representative samples of Latin American countries are lacking. The aim of this study is to present the design rationale of the Latin American Study of Nutrition and Health/Estudio Latinoamericano de Nutrición y Salud (ELANS) with a particular focus on its quality control procedures and recruitment processes.\ud
\ud
\ud
Methods/Design\ud
The ELANS is a multicenter cross-sectional nutrition and health surveillance study of a nationally representative sample of urban populations from eight Latin American countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Perú and Venezuela). A standard study protocol was designed to evaluate the nutritional intakes, physical activity levels, and anthropometric measurements of 9000 enrolled participants. The study was based on a complex, multistage sample design and the sample was stratified by gender, age (15 to 65 years old) and socioeconomic level. A small-scale pilot study was performed in each country to test the procedures and tools.\ud
\ud
\ud
Discussion\ud
This study will provide valuable information and a unique dataset regarding Latin America that will enable cross-country comparisons of nutritional statuses that focus on energy and macro- and micronutrient intakes, food patterns, and energy expenditure.\ud
\ud
\ud
Trial Registration\ud
Clinical Trials \ud
NCT0222662