On the structure of cortical microcircuits inferred from small sample sizes

The structure in cortical microcircuits deviates from what would be expected in a purely random network, which has been seen as evidence of clustering. To address this issue, we sought to reproduce the nonrandom features of cortical circuits by considering several distinct classes of network topology, including clustered networks, networks with distance-dependent connectivity, and those with broad degree distributions. To our surprise, we found that all of these qualitatively distinct topologies could account equally well for all reported nonrandom features despite being easily distinguishable from one another at the network level. This apparent paradox was a consequence of estimating network properties given only small sample sizes. In other words, networks that differ markedly in their global structure can look quite similar locally. This makes inferring network structure from small sample sizes, a necessity given the technical difficulty inherent in simultaneous intracellular recordings, problematic. We found that a network statistic called the sample degree correlation (SDC) overcomes this difficulty. The SDC depends only on parameters that can be estimated reliably given small sample sizes and is an accurate fingerprint of every topological family. We applied the SDC criterion to data from rat visual and somatosensory cortex and discovered that the connectivity was not consistent with any of these main topological classes. However, we were able to fit the experimental data with a more general network class, of which all previous topologies were special cases. The resulting network topology could be interpreted as a combination of physical spatial dependence and nonspatial, hierarchical clustering. SIGNIFICANCE STATEMENT The connectivity of cortical microcircuits exhibits features that are inconsistent with a simple random network. Here, we show that several classes of network models can account for this nonrandom structure despite qualitative differences in their global properties. This apparent paradox is a consequence of the small numbers of simultaneously recorded neurons in experiment: when inferred via small sample sizes, many networks may be indistinguishable despite being globally distinct. We develop a connectivity measure that successfully classifies networks even when estimated locally with a few neurons at a time. We show that data from rat cortex is consistent with a network in which the likelihood of a connection between neurons depends on spatial distance and on nonspatial, asymmetric clustering.Postprint (author's final draft

Сравнение эффективности Фурье и вейвлет анализов при оценке гидрогеодинамического влияния режима эксплуатации скважин

Исследовано воздействие работы эксплуатационных скважин на колебание напоров в наблюдательных скважинах и выделение частотных составляющих техногенного и природного колебаний в спектре. Показаны возможность использования Фурье-анализа и вейвлет-преобразования, а так же сравнительный анализ для оценки гидрогеодинамического влияния режима работы эксплуатационных скважин

Cardiovascular risk factors in Assyrians/Syrians and native Swedes with type 2 diabetes: a population-based epidemiological study

<p>Abstract</p> <p>Background</p> <p>A large number of people throughout the world have diabetes and the prevalence is increasing. Persons with diabetes have a twice higher risk of cardiovascular disease than those without diabetes. There is a lack of studies focusing on cardiovascular risk factors in Assyrians/Syrians with type 2 diabetes. The aim of this study is to estimate the prevalence of some cardiovascular risk factors among Assyrians/Syrians and native Swedes with type 2 diabetes and to study whether the association between ethnicity and cardio-vascular risk factors remains after adjustment for age, gender, employment status and housing tenure.</p> <p>Methods</p> <p>In the Swedish town of Södertälje 173 Assyrians/Syrians and 181 ethnic Swedes with type 2 diabetes participated in a study evaluating cardiovascular risk factors such as increased haemoglobin A1c (HbA1c), high blood lipids (total serum cholesterol and triglycerides), hypertension and high urinary albumin. The associations between the outcome variables and sociodemographic characteristics were estimated using unconditional logistic regression.</p> <p>Results</p> <p>The prevalence of increased triglycerides in Swedish-born subjects and Assyrian-Syrians was 61.5% and 39.7% respectively. Swedes had a prevalence of hypertension 76.8% compared to 57.8% in Assyrians/Syrians. In the final logistic models adjusted for gender, age, housing and employment the odds ratio (OR) for Swedish-born subjects for increased triglycerides was 2.80 (95% CI1.61-4.87) and for hypertension 2.32 (95% CI 1.35-4.00) compared to Assyrians-Syrians.</p> <p>Conclusion</p> <p>Ethnic Swedes had higher prevalence of increased triglycerides and hypertension than Assyrians/Syrians. Total cholesterol, HbA1c and urinary albumin did not differ between the two ethnic groups.</p

"I had the feeling that I was trapped" : a bedside qualitative study of cognitive and affective attitudes towards noninvasive ventilation in patients with acute respiratory failure

At the time of the study, Dr. Schmidt was supported by grants from the “Société de Réanimation de Langue Française”, “Fonds de Recherche en Santé Respiratoire”, “Collège des Enseignants de Réanimation Médicale”, and “Fonds d’Etudes et de Recherche du Corps Médical des Hôpitaux de Paris”.Background Noninvasive ventilation (NIV) is the application of mechanical ventilation through a mask. It is used to treat certain forms of acute respiratory failure in intensive care units (ICU). NIV has clinical benefits but can be anxiogenic for the patients. This study aimed at describing cognitive and affective attitudes toward NIV among patients experiencing NIV for the first time in the context of an ICU stay. Methods Semi-structured interviews were conducted in 10 patients during their ICU stay and soon after their first NIV experience. None of the patients had ever received NIV previously. Evaluative assertion analysis and thematic analysis were used to investigate cognitive and affective attitudes toward NIV before, during, and after the first NIV experience, as well as patient attitudes toward caregivers and relatives. Results Before their first NIV session, the cognitive attitudes of the patients were generally positive. They became less so and more ambiguous during and after NIV, as the patients discovered the actual barriers associated with NIV. Affective attitudes during NIV were more negative than affective attitudes before and after NIV, with reports of dyspnea, anxiety, fear, claustrophobic feelings, and reactivation of past traumatic experiences. The patients had more positive attitudes toward the presence of a caregiver during NIV, compared to the presence of a family member. Conclusion This study corroborates the possibly negative—or even traumatic—nature of the NIV experience, with emphasis on the role of affective attitudes. This is a rationale for evaluating the impact of NIV-targeted psychological interventions in ICU patients with acute respiratory failure.Publisher PDFPeer reviewe

Perigos biológicos e químicos numa unidade de produção de alimentos compostos para animais

Dissertação de mestrado em Sistemas de Prevenção e Controlo Alimentar, apresentada na Escola Superior Agrária de Santarém, Instituto Politécnico de Santarém.Na última década, a indústria de alimentos para animais sofreu alterações profundas, sendo muitos os fatores que contribuíram para essa mudança. Visto que a alimentação animal se tornou um assunto público isto conduziu a um enquadramento legal mais restrito e exigente, constituindo hoje a política de segurança alimentar o principal requisito para que as empresas possam estar no mercado, uma vez que a segurança dos produtos alimentares de origem animal começa com a segurança da alimentação animal. Na produção de alimentos compostos é utilizado um conjunto de ingredientes que poderão ser considerados eventuais perigos para os animais e, em última análise, para o homem. A indústria da alimentação animal trabalha com matérias-primas sólidas com baixos teores de humidade, baixo aw e elevados valores de pH. Tanto estes produtos utilizados para o fabrico dos alimentos compostos para animais como o produto final são armazenados à temperatura ambiente, por vezes com más condições de higiene, reunindo fatores propícios ao desenvolvimento de microrganismos adaptados a este tipo de condições ambientais. Com este trabalho, efetuou-se um levantamento de dados do histórico microbiológico e toxicológico de uma empresa, relativos a matérias-primas e alimentos compostos para animais. Identificaram-se as contagens de microrganismos acima das recomendações técnicas e ou legisladas, nomeadamente da família Enterobacteriaceae, de Escherichia coli, Clostridium perfringens e bolores, assim como também as amostras positivas em pesquisa de Salmonella spp e determinação de teor de Aflatoxina B1. Conclui-se que das análises de matérias-primas e alimentos compostos foram consideradas não conformes, respectivamente, 9,19% e 9,24% das amostras. Nas matérias-primas os contaminantes encontrados foram Enterobacteriaceae (5,14%) seguido de Salmonella spp (1,83%), Escherichia coli (1,10%), bolores (0,75%) e Clostridium perfrigens (0,36%). Dos agentes contaminantes encontrados nos alimentos compostos produzidos foram Enterobacteriaceae (3,80%), Escherichia coli (2,72%), Salmonella spp (1,63%), Clostridium perfrigens (0,81%) e bolores (0,27%).Over the last decade, feed industry has suffered profound changes, and several factors have contributed to that change. Since feed has become a public issue, this led to a stricter and more demanding legal framework, and today food safety policy is the main requirement for companies to stay in the market, for the safety of food products of animal origin begins with safe animal feed. The production of feed compounds makes use of some ingredients which can be considered potential hazards to animals and, ultimately, to humans. The feed industry operates with solid raw materials with low moisture, low aw and high pH. Both the products used for the manufacture of feed compounds and the final products are stored at room temperature, sometimes under poor hygiene, leading to conditions favorable to the growth of microorganisms adapted to this type of environmental conditions. In this work, we performed a survey of microbiological and toxicological historical data in a composing, in raw materials and feed compounds. We identified the presence of microorganisms in levels above these technical recommended, in particular of the family Enterobacteriaceae, Escherichia coli, Clostridium perfringens and also positive samples identified of Salmonella spp. From the analysis on raw materials and feed, 9,19% and 9,24% of the samples were, respectively considered non acepptable. The contaminations found on raw materials were Enterobactereaceae (5,14%) folowed by Salmonella spp (1,83%), Escherichia coli (1,10%), molds (0,75%) and Clostridium perfrigens (0,36%). On feed, contamination was found to be caused by Enterobactereaceae (3,80%), from which Escherichia coli (2,72%), Salmonella spp (1,63%), Clostridium perfrigens (0,81%) and molds (0,27%)

Five Years at the Edge: Watching Internet from the ISP Network

The Internet and the way people use it are constantly changing. Knowing traffic is crucial for operating the network, understanding users' need, and ultimately improving applications. Here, we provide an in-depth longitudinal view of Internet traffic in the last 5 years (from 2013 to 2017). We take the point of the view of a national-wide ISP and analyze flow-level rich measurements to pinpoint and quantify trends. We evaluate the providers' costs in terms of traffic consumption by users and services. We show that an ordinary broadband subscriber nowadays downloads more than twice as much as they used to do 5 years ago. Bandwidth hungry video services drive this change, while social messaging applications boom (and vanish) at incredible pace. We study how protocols and service infrastructures evolve over time, highlighting unpredictable events that may hamper traffic management policies. In the rush to bring servers closer and closer to users, we witness the birth of the sub-millisecond Internet, with caches located directly at ISP edges. The picture we take shows a lively Internet that always evolves and suddenly changes

Desenvolvimento e validação de um questionário de avaliação da atividade física para adolescentes

OBJETIVO: Desenvolver um questionário de atividade física para adolescentes brasileiros e verificar sua validade e reprodutibilidade. MÉTODOS: Participaram do estudo 94 adolescentes (30 meninos e 64 meninas) com idade entre 11 a 16 anos, em 2004. O questionário foi composto por 17 questões sobre atividades habituais exercidas nos últimos 12 meses (exercícios físicos/esportes e atividades de locomoção) e foi padronizado para gerar escores semanal e anual. Como método de referência utilizou-se o teste de corrida vai-e-vem de 20 metros com as variáveis tempo em minutos, velocidade máxima em km/h, consumo máximo de oxigênio e freqüência cardíaca máxima. Para a análise de validação, foram utilizados o coeficiente de Spearman e correlação ajustada por idade. Para a análise da reprodutibilidade, utilizou-se medida repetida com intervalo de 15 dias e coeficiente de correlação intraclasse. RESULTADOS: Para o escore semanal de atividade física, os maiores coeficientes de correlação foram obtidos com o tempo total para a análise em conjunto (r=0,19), velocidade total para os meninos (r=0,20), e consumo máximo de oxigênio e tempo total para as meninas (r=0,17). Para o escore anual de atividade física, os maiores coeficientes de correlação foram obtidos com o tempo total para a análise em conjunto (r=0,30), freqüência cardíaca final após o ajuste pela idade para os meninos (r=0,22) e tempo total para as meninas (r=0,23). Nas análises de reprodutibilidade, a correlação do escore semanal foi de 0,61 e a do escore anual foi de 0,68. CONCLUSÕES: O questionário apresentou evidências de validade e reprodutibilidade. Recomenda-se sua utilização para avaliação da atividade física habitual em estudos epidemiológicos com adolescentes