Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.1197120

Mobile Virtual Reality as an Educational Platform: A Pilot Study on the Impact of Immersion and Positive Emotion Induction in the Learning Process

[EN] The purpose of this study is to evaluate the influence of emotional induction and level of immersion on knowledge acquisition and motivation. Two conditions were used for immersion modulation: a high immersive condition, which consisted of the viewing of educational content through a head-mounted-display; and a low immersive condition, which was achieved through direct viewing on a tablet. The emotional conditions, created through video simulation, consisted of a positive versus neutral mood induction procedure. The participants were 56 high school students enrolled on a social science course. The results indicate a significant effect of the positive emotion/high immersive condition in knowledge acquisition while positive emotion induction had a positive effect on the interest subscale of the motivation assessment tool used for both immersive conditions.Olmos-Raya, E.; Ferreira-Cavalcanti, J.; Contero, M.; Castellanos-Baena, M.; Chicci-Giglioli, I.; Alcañiz, M. (2018). Mobile Virtual Reality as an Educational Platform: A Pilot Study on the Impact of Immersion and Positive Emotion Induction in the Learning Process. Eurasia Journal of Mathematics Science and Technology Education. 14(6):2045-2057. doi:10.29333/ejmste/858742045205714

Motor Performance In Kaingang Indigenous Children

Studies on indigenous children show low height for age, however there is a lack of literature on motor performance in these populations. Motor performance tests are important indicators in identifying factors of physical fi tness related to health. Objective: To compare the motor performance in Kaingang indigenous children. Methods: The study was descriptive and cross-sectional with 78 Kaingang schoolchildren aged between 8 and 9 years from the indigenous area of Rio das Cobras, in Paraná, Brazil. The children were classifi ed into two groups, Group A below (GA) and Group B (GB) above the -2 z-scores for the reference stature for age from the Centers for Disease Control and Prevention/National Center for Health Statistics. The data were collected using anthropometric measurements of their stature and motor performance tests for sitting and reaching (fl exibility), jumping distance (muscle power), sitting and lying down (strength and muscular resistance) and coming and going (agility). Analysis of covariance (p < 0.05) was used to compare the stature between the groups as well as their motor performance, controlled by age, and separated per sex. Results: Among the 78 schoolchildren evaluated, 45.5% of boys and 55.5% of girls were below the -2 zscores for stature at their age, classifi ed in GA, and 54.5% of boys and 44.5% of girls were above the -2 z-scores for stature at their age, classifi ed in GB. There was a signifi cant difference in stature between the groups, in both sexes. There was a signifi cant difference in the motor performance tests between children classifi ed as having a short stature and those not characterized as such, in both sexes. Conclusion: Short stature did not infl uence motor performance in the children studied.261485

Spirometry And Volumetric Capnography In Lung Function Assessment Of Obese And Normal-weight Individuals Without Asthma

To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. Methods: Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. Results: At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV1/FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p &lt;0.05). Volumetric capnography showed that obese individuals had a higher volume of produced carbon dioxide and alveolar tidal volume (p &lt;0.05). Additionally, the associations between dead space volume and tidal volume, as well as phase-3 slope normalized by tidal volume, were lower in healthy subjects (p &lt;0.05). These data suggest that obesity does not alter ventilation homogeneity, but flow homogeneity. After subdividing the groups by age, a greater difference in lung function was observed in obese and healthy individuals aged &gt;11 years (p &lt;0.05). Conclusion: Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV1/FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes. © 2017 Sociedade Brasileira de Pediatria

On the Treewidth of Dynamic Graphs

Dynamic graph theory is a novel, growing area that deals with graphs that change over time and is of great utility in modelling modern wireless, mobile and dynamic environments. As a graph evolves, possibly arbitrarily, it is challenging to identify the graph properties that can be preserved over time and understand their respective computability. In this paper we are concerned with the treewidth of dynamic graphs. We focus on metatheorems, which allow the generation of a series of results based on general properties of classes of structures. In graph theory two major metatheorems on treewidth provide complexity classifications by employing structural graph measures and finite model theory. Courcelle's Theorem gives a general tractability result for problems expressible in monadic second order logic on graphs of bounded treewidth, and Frick & Grohe demonstrate a similar result for first order logic and graphs of bounded local treewidth. We extend these theorems by showing that dynamic graphs of bounded (local) treewidth where the length of time over which the graph evolves and is observed is finite and bounded can be modelled in such a way that the (local) treewidth of the underlying graph is maintained. We show the application of these results to problems in dynamic graph theory and dynamic extensions to static problems. In addition we demonstrate that certain widely used dynamic graph classes naturally have bounded local treewidth

Estudos sobre a nutrição mineral do sorgo sacarino (Sorghum bicolor (L) Moench) cv. Brands. II: absorção e redistribuição do radiofósforo

This paper deals with the following aspects of the phosphatic nutrition of sweet sorghum: absorption of radiophosphate as influenced by time of uptake and external concentration; comparative foliar absorption of monoammonium and diammonium phosphate both in the presence and absence of urea; redistribution of previously absorbed and stored phosphate. Data obtained herewith allowed for the following conclusions to be drawn: (1) root absorption increased with time of contact, being higher in the case of excised when compared to roots in intact plants; (2) Michaelis and Menten kinetics are applicable to root uptake, the parameters being different for the two types of root material; (3) the two ammonium phosphates showed the same rate of uptake, which was not influenced by urea; (4) P deficient plants showed highes rates of uptake and translocation.Foi estudada a absorção radicular do radiofósforo sob influência do tempo de contato com a solução e da concentração externa. Foi também estudada a absorção foliar dos fosfatos mono e diamônico isolados e em presença de uréia. A redistribuiçao do P absorvido pelas raízes foi acompanhada através do fracionamento das formas de fósforo nos diversos órgaos da planta analisadas em diferentes períodos

QCD Corrections to QED Vacuum Polarization

We compute QCD corrections to QED calculations for vacuum polarization in background magnetic fields. Formally, the diagram for virtual $e\bar{e}$ loops is identical to the one for virtual $q\bar{q}$ loops. However due to confinement, or to the growth of $\alpha_s$ as $p^2$ decreases, a direct calculation of the diagram is not allowed. At large $p^2$ we consider the virtual $q\bar{q}$ diagram, in the intermediate region we discuss the role of the contribution of quark condensates \left and at the low-energy limit we consider the $\pi^0$, as well as charged pion $\pi^+\pi^-$ loops. Although these effects seem to be out of the measurement accuracy of photon-photon laboratory experiments they may be relevant for $\gamma$-ray burst propagation. In particular, for emissions from the center of the galaxy (8.5 kpc), we show that the mixing between the neutral pseudo-scalar pion $\pi_0$ and photons renders a deviation from the power-law spectrum in the $TeV$ range. As for scalar quark condensates \left and virtual $q\bar{q}$ loops are relevant only for very high radiation density $\sim 300 MeV/fm^3$ and very strong magnetic fields of order $\sim 10^{14} T$.Comment: 15 pages, 4 figures; Final versio

Comparative analysis of the secretome and interactome of Trypanosoma cruzi and Trypanosoma rangeli reveals species specific immune response modulating proteins

Chagas disease, a zoonosis caused by the flagellate protozoan Trypanosoma cruzi, is a chronic and systemic parasitic infection that affects ~5–7 million people worldwide, mainly in Latin America. Chagas disease is an emerging public health problem due to the lack of vaccines and effective treatments. According to recent studies, several T. cruzi secreted proteins interact with the human host during cell invasion. Moreover, some comparative studies with T. rangeli, which is non-pathogenic in humans, have been performed to identify proteins directly involved in the pathogenesis of the disease. In this study, we present an integrated analysis of canonical putative secreted proteins (PSPs) from both species. Additionally, we propose an interactome with human host and gene family clusters, and a phylogenetic inference of a selected protein. In total, we identified 322 exclusively PSPs in T. cruzi and 202 in T. rangeli. Among the PSPs identified in T. cruzi, we found several trans-sialidases, mucins, MASPs, proteins with phospholipase 2 domains (PLA2-like), and proteins with Hsp70 domains (Hsp70-like) which have been previously characterized and demonstrated to be related to T. cruzi virulence. PSPs found in T. rangeli were related to protozoan metabolism, specifically carboxylases and phosphatases. Furthermore, we also identified PSPs that may interact with the human immune system, including heat shock and MASP proteins, but in a lower number compared to T. cruzi. Interestingly, we describe a hypothetical hybrid interactome of PSPs which reveals that T. cruzi secreted molecules may be down-regulating IL-17 whilst T. rangeli may enhance the production of IL-15. These results will pave the way for a better understanding of the pathophysiology of Chagas disease and may ultimately lead to the identification of molecular targets, such as key PSPs, that could be used to minimize the health outcomes of Chagas disease by modulating the immune response triggered by T. cruzi infection