Communication Structure of Cortical Networks

Large-scale cortical networks exhibit characteristic topological properties that shape communication between brain regions and global cortical dynamics. Analysis of complex networks allows the description of connectedness, distance, clustering, and centrality that reveal different aspects of how the network's nodes communicate. Here, we focus on a novel analysis of complex walks in a series of mammalian cortical networks that model potential dynamics of information flow between individual brain regions. We introduce two new measures called absorption and driftness. Absorption is the average length of random walks between any two nodes, and takes into account all paths that may diffuse activity throughout the network. Driftness is the ratio between absorption and the corresponding shortest path length. For a given node of the network, we also define four related measurements, namely in- and out-absorption as well as in- and out-driftness, as the averages of the corresponding measures from all nodes to that node, and from that node to all nodes, respectively. We find that the cat thalamo-cortical system incorporates features of two classic network topologies, Erdös–Rényi graphs with respect to in-absorption and in-driftness, and configuration models with respect to out-absorption and out-driftness. Moreover, taken together these four measures separate the network nodes based on broad functional roles (visual, auditory, somatomotor, and frontolimbic)

Imunização contra influenza no Brasil: racionalidade e desafios

Campanhas de vacinação contra influenza na população idosa têm sido conduzidas no Brasil desde 1999. De acordo com levantamento da literatura realizada sobre influenza no Brasil, concluiu-se que dados sobre carga de doença são ainda escassos e imprecisos. Essas informações parecem indicar que a vacinação tem produzido algum impacto nas regiões Sul e Sudeste do País, mas não em outras regiões. Foram discutidas racionalidade técnica e científica para a imunização contra influenza, e argumentou-se que a atual estratégia de vacinação em todo o território nacional não levou em conta possíveis diferenças na ocorrência da doença causada por influenza entre as regiões do País. Foram sugeridas algumas atividades relacionadas à vigilância epidemiológica de influenza que se julgou necessárias para responder importantes questões referentes à vacinação e seu impacto no Brasil.Mass vaccination campaigns against influenza in the elderly have been conducted in Brazil since 1999. A search of the literature on influenza in Brazil indicated that data on disease burden are still scarce and inaccurate. Published data seem to indicate that vaccination has produced some impact in the southern and southeastern regions but not in other regions of Brazil. A discussion of the technical and scientific rationale for mass immunization against influenza is presented and it is argued that the current strategy has not taken into account potential differences in disease occurrence in different areas. It is suggested some epidemiological surveillance actions needed to address major concerns regarding mass influenza vaccination and its impact in Brazil

Relation between TNF-alpha and exercise induced bronchoconstriction

Introduction: Exercise-induced bronchoconstriction (EIB) describes an acute airway narrowing that occurs as a result of exercise. EIB is associated with a hyperosmolar environment that lead to airway smooth muscle contraction. The proinflammatory cytokine, TNF-alpha, has a prominent role in the development of airway hiperresponsiveness (AHR). A single bout of heavy exercise can trigger EIB. The aim of this research was to compare the response of TNF-alpha over time with the presence or absence of EIB in marathon runners. Methods: Thirty-eight male runners, who did not have any chronic or acute airway disease, performed maximal cardiopulmonary exercise testing on a treadmill coupled to the gas analyzer (FitMate ™, Cosmed, Italy). Was used a ramp protocol with fixed slope of 1% and an increase of load (1km/h) every minute. Spirometry was performed before (pre), immediately after, five, ten, fifteen and twenty minutes after exercise stress testing. Were considered positive for BIE those athletes that presented a decrease in expiratory volume in one second greater than 10% in any of the spirometric tests. Blood samples were obtained the day before the marathon, immediately and after 72 hours after the race. Cytokines were determined in serum by ELISA. Was used analysis of variance (ANOVA) with two factors, group and time of blood collection, considering repeated measures on the time factor. In the case of statistical significance for interaction group and blood was concluded that the behavior over time was significantly different between EIB negative (-) and EIB positive (+), in this case applied the method of Tukey\u27s multiple comparisons to determine the moment that occurred these differences (p\u3c0.05). Results: We observed a statistically significant difference (p=0.048) in the behavior of the concentration of TNF-alpha between groups EIB- and EIB+. The measure pre of the EIB+ have an higher concentration of TNF-alpha compared to those obtained immediately after the marathon for EIB+ and the results obtained at the three moments for EIB-. (Figure 1). Conclusion: Our results suggests that an inflammatory status in serum of the marathon runners presenting BIE, before the race may be associated with bronchoconstriction triggering

Practical application of the sign test on data from trial and meta-analysis.

Many practical situations faced in agricultural research does not allow assuming the normality of the data to be analyzed. In some of these situations, the researcher, not statistical, want to test hypotheses with minimal statistical security, but finds himself in trouble by not dominate approaches that require deeper knowledge in that discipline. The sign test has a very strong appeal for interpretability of results and is often sufficient for decision-making on the further direction of research or analysis. In this paper, we present two examples of application and interpretation of the test in the form available at Univariate routine SAS, one for data obtained for phosphorus content of the meta-analysis of available soil in areas under different forms of management, from dozens of published articles. The second example is data from testing in an area with strong physical condition of location of treatment and repetitions because the plants are perennials (coffee) and the treatments comprise the application of CO2 through a fixed system, expensive and rare (FACE - Free Air CO2 Enrichment). The results allowed us to evaluate the relevance of the hypotheses tested in a satisfactory manner considered by the researchers responsible for data

The first 62 AGN observed with SDSS-IV MaNGA - IV: gas excitation and star-formation rate distributions

We present maps of the ionized gas flux distributions, excitation, star-formation rate SFR, surface mass density $\Sigma_{H+}$, and obtain total values of SFR and ionized gas masses {\it M} for 62 Active Galactic Nuclei (AGN) observed with SDSS-IV MaNGA and compare them with those of a control sample of 112 non-active galaxies. The most luminous AGN -- with L(\rm{[OIII]}\lambda 5007) \ge 3.8\times 10^{40}\,\mbox{erg}\,\mbox{s}^{-1}, and those hosted by earlier-type galaxies are dominated by Seyfert excitation within 0.2 effective radius $R_e$ from the nucleus, surrounded by LINER excitation or transition regions, while the less luminous and hosted by later-type galaxies show equally frequent LINER and Seyfert excitation within $0.2\,R_e$. The extent $R$ of the region ionized by the AGN follows the relation $R\propto\,L(\rm{[OIII]})^{0.5}$ -- as in the case of the Broad-Line Region. The SFR distribution over the region ionized by hot stars is similar for AGN and controls, while the integrated SFR -- in the range $10^{-3}-10$\,M$_\odot$\,yr$^{-1}$ is also similar for the late-type sub-sample, but higher in the AGN for 75\% of the early-type sub-sample. We thus conclude that there is no signature of AGN quenching star formation in the body of the galaxy in our sample. We also find that 66\% of the AGN have higher ionized gas masses $M$ than the controls -- in the range 10$^5-3\times10^7$\,M$_\odot$ -- while 75\% of the AGN have higher $\Sigma_{H+}$ within $0.2\,R_e$ than the control galaxies

The Motions of Clusters of Galaxies and the Dipoles of the Peculiar Velocity Field

In preceding papers of this series, TF relations for galaxies in 24 clusters with radial velocities between 1000 and 9200 km/s (SCI sample) were obtained, a Tully-Fisher (TF) template relation was constructed and mean offsets of each cluster with respect to the template obtained. Here, an estimate of the line-of-sight peculiar velocities of the clusters and their associated errors are given. It is found that cluster peculiar velocities in the Cosmic Microwave Background reference frame do not exceed 600 k/ms and that their distribution has a line-of-sight dispersion of 300 k/ms, suggesting a more quiescent cluster peculiar velocity field than previously reported. When measured in a reference frame in which the Local Group is at rest, the set of clusters at cz > 3000 km/s exhibits a dipole moment in agreement with that of the CMB, both in amplitude and apex direction. It is estimated that the bulk flow of a sphere of 6000 km/s radius in the CMB reference frame is between 140 and 320 km/s. These results are in agreement with those obtained from an independent sample of field galaxies (Giovanelli et al. 1998; see astro-ph/9807274)Comment: 9 pages, 2 tables, 7 figures, uses AAS LaTex; to appear in A

The SOAR Gravitational Arc Survey - I: Survey overview and photometric catalogs

We present the first results of the SOAR (Southern Astrophysical Research) Gravitational Arc Survey (SOGRAS). The survey imaged 47 clusters in two redshift intervals centered at $z=0.27$ and $z=0.55$, targeting the richest clusters in each interval. Images were obtained in the $g'$, $r'$ and $i'$ bands using the SOAR Optical Imager (SOI), with a median seeing of 0.83, 0.76 and 0.71 arcsec, respectively, in these filters. Most of the survey clusters are located within the Sloan Digital Sky Survey (SDSS) Stripe 82 region and all of them are in the SDSS footprint. Photometric calibration was therefore performed using SDSS stars located in our SOI fields. We reached for galaxies in all fields the detection limits of $g \sim 23.5$, $r \sim 23$ and $i \sim 22.5$ for a signal-to-noise ratio (S/N) = 3. As a by-product of the image processing, we generated a source catalogue with 19760 entries, the vast majority of which are galaxies, where we list their positions, magnitudes and shape parameters. We compared our galaxy shape measurements to those of local galaxies and concluded that they were not strongly affected by seeing. From the catalogue data, we are able to identify a red sequence of galaxies in most clusters in the lower $z$ range. We found 16 gravitational arc candidates around 8 clusters in our sample. They tend to be bluer than the central galaxies in the lensing cluster. A preliminary analysis indicates that $\sim 10$ of the clusters have arcs around them, with a possible indication of a larger efficiency associated to the high-$z$ systems when compared to the low-$z$ ones. Deeper follow-up images with Gemini strengthen the case for the strong lensing nature of the candidates found in this survey.Comment: 17 pages, 11 figures (most of them multi-panel) MNRAS (2013

Pancreatite aguda biliar: um estudo de coorte prospectivo

OBJECTIVE: Acute biliary pancreatitis (ABP) is a disease with high morbidity and mortality rates but poorly studied in Brazil. Our objective was to describe the differential  diagnosis for the etiology of ABP and assess the severity and treatment of the disease at the Hospital de Clínicas de Porto Alegre, in 1999. MATERIALS AND METHODS: We carried out a cohort, prospective study in 65 (78.4%) patients who presented amylase greater than 440 mg/dl and acute biliary pancreatitis (ABP). We assessed biliary Ranson scores, modified Glasgow scores, APACHE-II and APACHE-O of our population in order to determine the severity of the disease. These scores and values were followed-up during the evolution of the disease. RESULTS: Twelve patients presented clinical evolution of the disease. The systemic complications were kidney failure (n=4), respiratory failure (n=3), shock (n=3), and sepsis associated with cholangitis (n=1). The local complications, in turn, were peripancreatic fluid collection (n=3), pancreatic necroses (n=3), pancreatic pseudocyst (n=1), and pancreatic fistula (n=1). There was only one case of death, which occurred due to acute myocardial infarction and refractory hypocalcemia. The prognostic criteria, according to the number of positive parameters, indicated relative risk (RR) from 4.7 to 11.2, sensitivity from 33.3% to 83.3%, specificity from 79.2% to 98.1%, positive predictive value from 45.0% to 83.3%, negative predictive value from 86.4% to 95.5%, and accuracy from 78.5% to 89.6%. The parameters that presented a separate correlation with severity were white blood cell count >18,000/mm3 , LDH >400 UI/l, 10% decrease in hematocrit levels, serum calcium levels <8 mg/dl, increase in urea nitrogen levels >2 mg/dl, AST >200 mg/dl, LDH >600 UI/l, white cell count >15,000/mm3 , urea >45 mg/dl, arterial pH £7.33 or ³7.49, creatinine levels £0.6 or ³1.4, hematocrit levels £30 or ³45,9, white cell count £3,000 or ³14,900. CONCLUSION: biliary Ranson scores, modified Glasgow scores, APACHE-II and APACHE-O presented good sensitivity and specificity. Multidisciplinary protocols should be implemented in order to achieve optimal treatment results. OBJETIVO: A pancreatite aguda biliar (PAB) é uma doença com morbidade e mortalidade elevadas mas pouco estudada no Brasil. O objetivo deste trabalho é detalhar o diagnóstico diferencial etiológico, a gravidade e o tratamento da PAB no Hospital de Clínicas de Porto Alegre em 1999. MATERIAIS E MÉTODOS: Foram avaliados em estudo de coorte, prospectivo, todos os pacientes com amilase superior a 440 mg/dl e incluídos 65 (78,4%) que apresentavam PAB. Esta amostra foi submetida à determinação de gravidade pelos critérios de Ranson biliar, Glasgow modificado, APACHE-II e APACHE-O e acompanhada durante a evolução da doença. RESULTADOS: Doze pacientes (18,5%) apresentaram evolução clínica com 19 complicações. As sistêmicas foram: falência renal (n = 4), insuficiência respiratória (n = 3), choque (n = 3) e sepse por colangite (n = 1). As complicações locais foram: coleções líquidas peripancreáticas (n = 3), necroses pancreáticas (n = 3), pseudocisto pancreático (n = 1), fístula pancreática (n = 1). Houve apenas uma morte relacionada a infarto agudo do miocárdio e hipocalcemia refratária. Os critérios prognósticos, conforme o número de parâmetros positivos, apresentaram um risco relativo que variou de 4,7 a 11,2, sensibilidade de 33,3% a 83,3%, especificidade de 79,2% a 98,1%, valor preditivo positivo de 45,0% a 83,3%, valor preditivo negativo de 86,4% a 95,5% e acurácia de 78,5% a 89,6%. Isoladamente, os parâmetros que apresentaram correlação com a gravidade foram leucograma >18000/mm3 , LDH >400 UI/L, queda ³10% hematócrito, cálcio sérico <8 mg/dL, aumento do nitrogênio uréico >2 mg/dL, AST >200 mg/dL, LDH >600 UI/L, leucograma >15000 mm3 , uréia >45 mg/dL, pH arterial £7,33 ou ³7,49, creatinina £0,6 ou ³1,4, Ht £30 ou ³45,9, leucócitos £ 3 ou ³14,9 (mil). CONCLUSÕES: Os critérios de Ranson, Glasgow, APACHE-II e APACHE-O apresentam boa sensibilidade e especificidade. O manejo da PAB deve ser revisto a partir de protocolos institucionais multidisciplinares