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.

Conhecimento do enfermeiro sobre as ações de vigilância epidemiológica no Hospital Universitário Onofre Lopes, Natal, RN

This is an exploratory descriptive study with quantitative approach, aiming to verify the nurses' knowledge concerning the epidemiological surveillance activities at the Onofre Lopes hospital (HUOL), in Natal, Rio Grande do Norte. The study was performed with 63 nurses from the hospital and the data were collected through a questionnaire. All data were analyzed using descriptive statistics. The results were discussed and organized into four sections: nurses' knowledge on hospital epidemiological surveillance; procedures of the professional nurse through compulsory notification diseases; difficulties found by nurses to register the compulsory notification diseases and suggestions of strategies to joint epidemiological surveillance service with the care practices of nurses. The results showed that 55.55% of nurses know the main action of epidemiological surveillance, compulsory notification of diseases, and that 42.86% reported to the Hospital Epidemiology Center , while 57.14% did not allocate the information for this service. Most nurses found it difficult to perform notification for not knowing its flow; for the surveillance service does not operate 24 hours and for vagueness on diagnostic of disorders. Suggestions of strategies to improve the quality of epidemiological information are focused on training of nurses in hospital epidemiological surveillance; working in partnership with the surveillance center; diffusion of information on surveillance and conducting a daily active search. It comes to conclusion that most nurses don't notify the Surveillance Center about Compulsory Notification Diseases and it wasn't observed the incorporation of integrality values between the hospital surveillance and all nurses, since this principle guides the actions of health services based on dialogue, listening, ethical commitment, sharing of knowledge among professionals of various services and respect towards other professionals. Therefore, the integrality gap in the actions of the nurses studied, as well as in the surveillance service does not mobilize the potential of such services to changes in the sense of achievement of practices aimed at a special attention model that combines preventive and corrective actions, proposed and desired by SUS. Through the difficulties presented, it becomes important to recommend educational processes with strategy to transform the conducts, besides proposing actions under the principle of integrality provide responses agile and effective, as the purpose of VE hospital emergency care by the current epidemic

A educação permanente em saúde na ótica dos cirurgiões dentistas

This study aimed to examine the perception of dentist-surgeon about the Permanent Education in Health (PEH). It is characterized as a qualitative research with focus in the field of public health policies. It refers specifically to the development of Permanent Education policy in Health in the state of Rio Grande do Norte. They were participants of this research 42 dentist surgeons and 83.3% females and 16.7% males, participants in Specialization courses approved and agreed by the Permanent Education Center in Health (PEC-RN) in the period 2005 to 2007. These professionals are part of the Family Health Strategy (FHS), and 11.9% work in management at the central level and 88.1% are directly related to oral health care in the Basic Health Units of the Family, 30 cities in the state. Data collection was through a questionnaire, with questions that guided the research development and achieve the objectives proposed. The socio-demographic data were analyzed using the descriptive statistics and subjective content was subjected to content analysis by Bardin. The emerging categories from the textual material generated by respondents were: program content, methodological approach and concepts of Permanent Education in Health. The subjects surveyed reported that the program content is more comprehensive and directs to the reflection of everyday practices, with regard to the methodological approach, concern that occurs through discussion and reflection with dynamic, participative, varied and constructive activities, questioning and putting as the main focus. As for understanding of the concepts of the PEH, there was a consensus that define as education stable strategies which contributing to transform and improve the health workers to have the upgrade, improvement of practices, being based on everyday experience and taking into account the accumulation and renewal of these experiences. Therefore, results presented showed that there is a clear understanding of the subjects on the proposals and guidelines of the PEH. It was concluded that lack continuous access to the policies proposed by Ministry of Health involving health workers, managers, communities, through social control and the teaching-service integration and that they are worked within the health system and can classify all these segments of society favor the existence of a more participatory, effective, fair and better quality health service