Undersampled Critical Branching Processes on Small-World and Random Networks Fail to Reproduce the Statistics of Spike Avalanches

The power-law size distributions obtained experimentally for neuronal avalanches are an important evidence of criticality in the brain. This evidence is supported by the fact that a critical branching process exhibits the same exponent t~3=2. Models at criticality have been employed to mimic avalanche propagation and explain the statistics observed experimentally. However, a crucial aspect of neuronal recordings has been almost completely neglected in the models: undersampling. While in a typical multielectrode array hundreds of neurons are recorded, in the same area of neuronal tissue tens of thousands of neurons can be found. Here we investigate the consequences of undersampling in models with three different topologies (two-dimensional, small-world and random network) and three different dynamical regimes (subcritical, critical and supercritical). We found that undersampling modifies avalanche size distributions, extinguishing the power laws observed in critical systems. Distributions from subcritical systems are also modified, but the shape of the undersampled distributions is more similar to that of a fully sampled system. Undersampled supercritical systems can recover the general characteristics of the fully sampled version, provided that enough neurons are measured. Undersampling in two-dimensional and small-world networks leads to similar effects, while the random network is insensitive to sampling density due to the lack of a well-defined neighborhood. We conjecture that neuronal avalanches recorded from local field potentials avoid undersampling effects due to the nature of this signal, but the same does not hold for spike avalanches. We conclude that undersampled branching-process-like models in these topologies fail to reproduce the statistics of spike avalanches.

Undersampled Critical Branching Processes on Small-World and Random Networks Fail to Reproduce the Statistics of Spike Avalanches

The power-law size distributions obtained experimentally for neuronal avalanches are an important evidence of criticality in the brain. This evidence is supported by the fact that a critical branching process exhibits the same exponent t~3=2. Models at criticality have been employed to mimic avalanche propagation and explain the statistics observed experimentally. However, a crucial aspect of neuronal recordings has been almost completely neglected in the models: undersampling. While in a typical multielectrode array hundreds of neurons are recorded, in the same area of neuronal tissue tens of thousands of neurons can be found. Here we investigate the consequences of undersampling in models with three different topologies (two-dimensional, small-world and random network) and three different dynamical regimes (subcritical, critical and supercritical). We found that undersampling modifies avalanche size distributions, extinguishing the power laws observed in critical systems. Distributions from subcritical systems are also modified, but the shape of the undersampled distributions is more similar to that of a fully sampled system. Undersampled supercritical systems can recover the general characteristics of the fully sampled version, provided that enough neurons are measured. Undersampling in two-dimensional and small-world networks leads to similar effects, while the random network is insensitive to sampling density due to the lack of a well-defined neighborhood. We conjecture that neuronal avalanches recorded from local field potentials avoid undersampling effects due to the nature of this signal, but the same does not hold for spike avalanches. We conclude that undersampled branching-process-like models in these topologies fail to reproduce the statistics of spike avalanches.

O conhecimento e as atitudes das famílias de pacientes em tratamento em tuberculose na atenção primária à saúde

This study thus sought to examine knowledge about TB and attitudes of patients families in disease treatment in Primary Health Care in Natal- RN. To this end, a cross-sectional study was undertaken through a questionnaire with families of patients diagnosed with TB and follow up by APS from Natal. The study subjects were recruited from a non-probabilistic way, by convenience, contemplating a sample of 50 families. Among the criteria considered for inclusion of subjects, older than 18 years were considered, as well as residing with the TB patient and in Natal and availability to participate in the research. Data collection was performed by own researcher and an assistant, through a questionnaire with families of patients diagnosed with TB following the double independent digitalization of data. In the analytical phase, was initially conducted an exploratory phase and univariate data, with description of the position measurements (mean, median, mode) and dispersion (confidence interval and standard deviation). In bivariate analysis, it was conducted an intersection of dependent variables of knowledge e and changes of attitude dichotomous, with each of the independent variables, using contingency tables and calculating the chi-square test and, when appropriate, the Fisher exact test. In 2x2 tables, calculated the odds ratio (OR) with confidence intervals of 95% (95% CI). From the selected sample, 43 (86%) subjects were female, average age and median respectively of 46.64 and 46.50 years, 25 (50%) had elementary school. The knowledge expressed by family members about TB was considered satisfactory. However, the lack of interest of the family (54%) in seeking information about tuberculosis; the wrong way of reply in relation to the organism causing the disease (64%); the water content (62%) and contaminated food (54% ) as a means of spreading TB was a weakness identified in the investigation. Regarding the time of transmission, 90% of respondents indicated not know or answered wrong. From investigated independent variables, only two were associated with lack of knowledge of TB, and they did not have religion (OR: 0.146, 95% CI: 0.027 to 0.800) and income below 1, 7 minimum wages (OR: 0.155, 95% CI: 0.029 to 0.813). Thus they seem to exercise a protective effect on this outcome. As for the changes in attitude, most of the found variables had no association with statistical significance, except no internet access (OR: 0.212, 95% CI: 0,048-0, 935). Most attitudes were positive in relation to TB patient. Results have demonstrated weaknesses in TB care, which has taken on a more individual and welfare character. Data not only express health outcomes produced by health services, but also the political and social situation of the families that are affected by TB

Rendimento acadêmico e sua relação com os estilos de personalidade de estudantes universitários

One of the Psychology challenges, especially among the assessment and educational areas, is to understand and predict individual differences. In this context, this research aimed to verify the personality styles of students with high and low academic performance. The study included 236 university students from Petrolina-PE and Juazeiro-BA campus of the UNIVASF (Universidade Federal do Vale do São Francisco). They were uniformly distributed in four disciplines (medicine, psychology, administration and civil engineering), 10 students from each semester (five highest scores average students and five lowest scores average students) took place of the sample. The Millon Index Personality Styles (MIPS) was applied to analyze the personality/behavioral styles of the students. The MIPS is a 180 dichotomous (true/false) item scale. It was also developed and applied a questionnaire about the students characteristics and their academic information. Descriptive and central tendency statistics analysis (mean, standard deviation, frequency and percentage) were done to provide sample information. Then we performed a Mann-Whitney test in the overall sample and in each course and a factorial ANOVA. The results suggest that the university population is heterogeneous and there are significant differences (p <0.05) between the personality styles of students with high and low academic performance, when analyzing the overall sample and in courses of different areas of knowledge. Students of Medicine who have higher performance as personality styles prevalent the conformism and compliance, while students with lower income in this course, the styles are: innovation and discrepancy. Psychology students with higher income are more systematic and lower income students to score significantly on accommodation. The civil engineering students of the two groups differed only in personality style intuition, being such a style more characteristic of higher income students. Students of Management with higher yield stand out more in the style of the doubt and lower yields in these styles: individual, reflection and discrepancy. This study is correlational, but had an exploratory nature because there are no studies about this relationship in Brazil. Therefore, it provided a better understanding of the action characteristics of students with high and low academic performance. Further studies using the Big Five Personality Factors instruments are required because it is the most used model in understanding the influence of personality on students performance. This way, the relation between personality and academic performance will be better discussed. Otherwise, it will be possible to compare with the existing studies in the area

Lógica BDI fuzzy

Intendding to understand how the human mind operates, some philosophers and psycologists began to study about rationality. Theories were built from those studies and nowadays that interest have been extended to many other areas such as computing engineering and computing science, but with a minimal distinction at its goal: to understand the mind operational proccess and apply it on agents modelling to become possible the implementation (of softwares or hardwares) with the agent-oriented paradigm where agents are able to deliberate their own plans of actions. In computing science, the sub-area of multiagents systems has progressed using several works concerning artificial intelligence, computational logic, distributed systems, games theory and even philosophy and psycology. This present work hopes to show how it can be get a logical formalisation extention of a rational agents architecture model called BDI (based in a philosophic Bratman s Theory) in which agents are capable to deliberate actions from its beliefs, desires and intentions. The formalisation of this model is called BDI logic and it is a modal logic (in general it is a branching time logic) with three access relations: B, D and I. And here, it will show two possible extentions that tranform BDI logic in a modal-fuzzy logic where the formulae and the access relations can be evaluated by values from the interval [0,1]

Diversidade de Seirini (Collembola, Arthropleona, Entomobryidae), em áreas úmidas da caatinga

The family Entomobryidae is one of the most diverse families of Collembola in Northeast Brazil. Data on its diversity may be considered undervalued due to low collection efforts in the region. In this study, five areas in the Northeast region were sampled, to evaluate the species richness of this family. The study was done in the Serra da Jibóia, Santa Terezinha municipality, Bahia; Serra das Confusões, Caracol municipality, Piauí; Chapada do Araripe, Crato municipality, Ceará; Mata do Pau-Ferro, Areia municipality, Paraíba and Parque Nacional de Ubajara, Ubajara municipality, Ceará, all considered humid areas of Caatinga. Collections were made using pitfall traps and entomological aspirators. All the collected material was screened, mounted on slides, identified and, finally, the descriptions of some of the new species encountered were made. A total of 48 Entomobryidae species belonging to nine genera were recorded and 27 of these were new to science, representing a percentage of 56.25% of the total. A new record for Brazil was identified and several new records were made to the States. Seira was the genus with wider distribution and it was the only one found in all areas and the most representative with the highest number of recorded species (26). This result was expected, because individuals of the genus Seira have a good adaptability to semi-arid environments, a fact that has already been proven in previous research. Seven new species of Seira were described. A dichotomous key to genera and species of Seirini from Brazil was drafted. This work demonstrates the great potential of Entomobryidae and Seirini in the Northeast, despite having been held in very restricted areas, obtained important results for the knowledge of fauna of the group