Blockade of AT1 type receptors for angiotensin II prevents cardiac microvascular fibrosis induced by chronic stress in Sprague-Dawley rats.

To test the effects of chronic-stress on the cardiovascular system, the model of chronic mild unpredictable stress (CMS) has been widely used. The CMS protocol consists of the random, intermittent, and unpredictable exposure of laboratory animals to a variety of stressors, during 3 consecutive weeks. In this study, we tested the hypothesis that exposure to the CMS protocol leads to left ventricle microcirculatory remodeling that can be attenuated by angiotensin II receptor blockade. Male Sprague-Dawley rats were randomly assigned into four groups: Control, Stress, Control + losartan, and Stress + losartan (N = 6, each group, losartan: 20 mg/kg/day). The rats were euthanized 15 days after CMS exposure, and blood samples and left ventricle were collected. Rats submitted to CMS presented increased glycemia, corticosterone, noradrenaline and adrenaline concentration, and losartan reduced the concentration of the circulating amines. Cardiac angiotensin II, measured by high-performance liquid chromatography (HPLC), was significantly increased in the CMS group, and losartan treatment reduced it, while angiotensin 1-7 was significantly higher in the CMS losartan-treated group as compared with CMS. Histological analysis, verified by transmission electron microscopy, showed that rats exposed to CMS presented increased perivascular collagen and losartan effectively prevented the development of this process. Hence, CMS induced a state of microvascular disease, with increased perivascular collagen deposition, that may be the trigger for further development of cardiovascular disease. In this case, CMS fibrosis is associated with increased production of catecholamines and with a disruption of renin-angiotensin system balance, which can be prevented by angiotensin II receptor blockade.

Comparison of Cliff-Lorimer-Based Methods of Scanning Transmission Electron Microscopy (STEM) Quantitative X-Ray Microanalysis for Application to Silicon Oxycarbides Thin Films.

In this work, we compare the results of different Cliff-Lorimer (Cliff & Lorimer 1975) based methods in the case of a quantitative energy dispersive spectrometry investigation of light elements in ternary C-O-Si thin films. To determine the Cliff-Lorimer (C-L) k-factors, we fabricated, by focused ion beam, a standard consisting of a wedge lamella with a truncated tip, composed of two parallel SiO2 and 4H-SiC stripes. In 4H-SiC, it was not possible to obtain reliable k-factors from standard extrapolation methods owing to the strong CK-photon absorption. To overcome this problem, an extrapolation method exploiting the shape of the truncated tip of the lamella is proposed herein. The k-factors thus determined, were then used in an application of the C-L quantification procedure to a defect found at the SiO2/4H-SiC interface in the channel region of a metal-oxide field-effect-transistor device. As in this procedure, the sample thickness is required, a method to determine this quantity from the averaged and normalized scanning transmission electron microscopy intensity is also detailed. Monte Carlo simulations were used to investigate the discrepancy between experimental and theoretical k-factors and to bridge the gap between the k-factor and the Watanabe and Williams ζ-factor methods (Watanabe & Williams, 2006).

Alternative pathways for angiotensin II production as an important determinant of kidney damage in endotoxemia.

Sepsis is an uncontrolled systemic inflammatory response against an infection and a major public health issue worldwide. This condition affects several organs, and, when caused by Gram-negative bacteria, kidneys are particularly damaged. Due to the importance of renin-angiotensin system (RAS) in regulating renal function, in the present study, we aimed to investigate the effects of endotoxemia over the renal RAS. Wistar rats were injected with Escherichia coli lipopolysaccharide (LPS) (4 mg/kg), mimicking the endotoxemia induced by Gram-negative bacteria. Three days after treatment, body mass, blood pressure, and plasma nitric oxide (NO) were reduced, indicating that endotoxemia triggered cardiovascular and metabolic consequences and that hypotension was maintained by NO-independent mechanisms. Regarding the effects in renal tissue, inducible NO synthase (iNOS) was diminished, but no changes in the renal level of NO were detected. RAS was also highly affected by endotoxemia, since renin, angiotensin-converting enzyme (ACE), and ACE2 activities were altered in renal tissue. Although these enzymes were modulated, only angiotensin (ANG) II was augmented in kidneys; ANG I and ANG 1-7 levels were not influenced by LPS. Cathepsin G and chymase activities were increased in the endotoxemia group, suggesting alternative pathways for ANG II formation. Taken together, our data suggest the activation of noncanonical pathways for ANG II production and the presence of renal vasoconstriction and tissue damage in our animal model. In summary, the systemic administration of LPS affects renal RAS, what may contribute for several deleterious effects of endotoxemia over kidneys.

Cardiac-specific suppression of NF-κB signaling prevents diabetic cardiomyopathy via inhibition of the renin-angiotensin system.

Activation of NF-κB signaling in the heart may be protective or deleterious depending on the pathological context. In diabetes, the role of NF-κB in cardiac dysfunction has been investigated using pharmacological approaches that have a limitation of being nonspecific. Furthermore, the specific cellular pathways by which NF-κB modulates heart function in diabetes have not been identified. To address these questions, we used a transgenic mouse line expressing mutated IκB-α in the heart (3M mice), which prevented activation of canonical NF-κB signaling. Diabetes was developed by streptozotocin injections in wild-type (WT) and 3M mice. Diabetic WT mice developed systolic and diastolic cardiac dysfunction by the 12th week, as measured by echocardiography. In contrast, cardiac function was preserved in 3M mice up to 24 wk of diabetes. Diabetes induced an elevation in cardiac oxidative stress in diabetic WT mice but not 3M mice compared with nondiabetic control mice. In diabetic WT mice, an increase in the phospholamban/sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 ratio and decrease in ryanodine receptor expression were observed, whereas diabetic 3M mice showed an opposite effect on these parameters of Ca(2+) handling. Significantly, renin-angiotensin system activity was suppressed in diabetic 3M mice compared with an increase in WT animals. In conclusion, these results demonstrate that inhibition of NF-κB signaling in the heart prevents diabetes-induced cardiac dysfunction through preserved Ca(2+) handling and inhibition of the cardiac renin-angiotensin system.

FIB preparation of a NiO Wedge-Lamella and STEM X-ray microanalysis for the determination of the experimental k(O-Ni) Cliff-Lorimer coefficient.

A method for the fabrication of a wedge-shaped thin NiO lamella by focused ion beam is reported. The starting sample is an oxidized bulk single crystalline, <100> oriented, Ni commercial standard. The lamella is employed for the determination, by analytical electron microscopy at 200 kV of the experimental k(O-Ni) Cliff-Lorimer (G. Cliff & G.W. Lorimer, J Microsc 103, 203-207, 1975) coefficient, according to the extrapolation method by Van Cappellen (E. Van Cappellen, Microsc Microstruct Microanal 1, 1-22, 1990). The result thus obtained is compared to the theoretical k(O-Ni) values either implemented into the commercial software for X-ray microanalysis quantification of the scanning transmission electron microscopy/energy dispersive spectrometry equipment or calculated by the Monte Carlo method. Significant differences among the three values are found. This confirms that for a reliable quantification of binary alloys containing light elements, the choice of the Cliff-Lorimer coefficients is crucial and experimental values are recommended.

Resolving statistical uncertainty in correlation dimension estimation.

In this paper we propose a novel method for obtaining standard errors and confidence intervals for the correlation dimension estimated on an observed chaotic time series. This method is based on the U-Statistics theory and an ingenious combination of the moving block and parametric bootstrap procedures. We test the method on the basis of computer simulations for both clean and noisy series. We show that the distribution of the correlation dimension estimate obtained by our method agrees very well with the "true" distribution obtained by the Monte Carlo simulation. One of the main advantage of our method is the ability to estimate the distribution (and hence, the standard error) of the correlation dimension estimate using only one observed time series.

Rumer's transformation: A symmetry puzzle standing for half a century.

In 1966, only a few months after the complete elucidation of the standard nuclear genetic code (Kay, 2000), the Russian theoretical physicist Yury Borisovich Rumer uncovered the existence of a particular symmetry (Rumer, 1966): when the keto-amino transformation (also known as Rumer's transformation) is applied to the bases of a codon then the degeneracy of the transformed codon was changed. In particular, if the amino acid associated to the starting codon has degeneracy 4, then the amino acid associated to the transformed codon has degeneracy 1, 2 or 3 (and vice versa). After half a century from this discovery and despite the universality of Rumer's symmetry, little is known about its origin and its possible biological significance. In this article we show that Rumer's symmetry could have originated in an ancestral version of the genetic code, i.e., the pre-early code, and is a natural consequence of the stereo-chemical symmetries of the ancestral synthesis machinery working around such code (Gonzalez et al., 2019). Moreover, the conservation of Rumer's symmetry through evolutionary periods suggests a connection with key biological features. In this respect, intriguing possibilities include those of error detection/correction, control over the synthesis of proteins, and frame maintenance. To a certain extent, such ideas have been explored in the framework of a mathematical model of the genetic code (the non-power model of the genetic code (Gonzalez, 2004; Gonzalez, 2008; Gonzalez et al., 2016), whose definition of dichotomic classes naturally includes Rumer's symmetry (Gonzalez, 2008; Gonzalez et al., 2006, 2008) and the theory of circular codes (Arquès and Michel, 1996; Gonzalez et al., 2011; Fimmel et al., 2015).

X-ray microanalysis combined with monte carlo simulation for the analysis of layered thin films: the case of carbon contamination.

A previously developed Monte Carlo code has been extended to the X-ray microanalysis in a (scanning) transmission electron microscope of plan sections, consisting of bilayers and triple layers. To test the validity of this method for quantification purposes, a commercially available NiOx (x 1) thin film, deposited on a carbon layer, has been chosen. The composition and thickness of the NiO film and the thickness of the C support layer are obtained by fitting to the three X-ray intensity ratios I(NiK)/I(OK), I(NiK)/I(CK), and I(OK)/I(CK). Moreover, it has been investigated to what extent the resulting film composition is affected by the presence of a contaminating carbon film at the sample surface. To this end, the sample has been analyzed both in the (recommended) "grid downward" geometry and in the upside/down ("grid upward") situation. It is found that a carbon contaminating film of few tens of nanometers must be assumed in both cases, in addition to the C support film. Consequently, assuming the proper C/NiOx/C stack in the simulations, the Monte Carlo method yields the correct oxygen concentration and thickness of the NiOx film.

Coach Turnover in Top Professional Brazilian Football Championship: A Multilevel Survival Analysis.

In this study, we examined the probability of coaches' survival in the top Brazilian professional football championship considering variation across the competitive seasons between 2012 and 2017, considering a multilevel framework. We also considered whether previous coaching experience in the top Brazilian professional football championship would change the probability of coaches' survival across the season. The data considered 4,560 games from the top professional Brazilian football league (Campeonato Brasileiro Série A) between the 2012 and 2017 seasons. At the start of each season, the coach from each team was followed, being recorded at the time the event occurred, i.e., the coach being sacked. A total survival of 120 coaches was considered between the seasons of 2012 and 2017, i.e., 20 coaches at the beginning of each season. Coaches were assigned as novice (no previous experience as head coach in the top Brazilian championship) or experienced (with at least some previous experience as head coach in the top Brazilian championship). Data were available and extracted from the official website of the Brazilian Football Confederation. On average and considering un-pooled observations, the median life of a coach was about 16.5 rounds. Considering variation between 2012 and 2017 seasons, only about 26.3% (95% CI: 18.2-36.1) of the coaches ended a season without being sacked. By mid-season, at round 19, the probability of coaches' survival was 0.42 (95% CI: 0.32-0.53). Variation between season on survival estimates per round was substantial (between-season standard deviation = 0.48, 95% credible intervals: 0.25-0.95; corresponding to an inverse logit = 0.62, 95% CI: 0.56-0.72). There was no substantial variation between novice and experienced coaches' survival probability. The present results expose the vulnerability of the coaching context in Brazilian football, potentially highlighting an excessive emphasis on short-term results to mediate club management decisions.

Strong short-range correlations and dichotomic codon classes in coding DNA sequences.

The study of correlation structures in DNA sequences is of great interest because it allows us to obtain structural and functional information about underlying genetic mechanisms. In this paper we present a study of the correlation structure of protein coding sequences of DNA based on a recently developed mathematical representation of the genetic code. A fundamental consequence of such representation is that codons can be assigned a parity class (odd-even). Such parity can be obtained by means of a nonlinear algorithm acting on the chemical character of the codon bases. In the same setting the Rumer's class can be naturally described and a new dichotomic class, the hidden class, can be defined. Moreover, we show that the set of DNA's base transformations associated to the three dichotomic classes can be put in a compact group-theoretic framework. We use the dichotomic classes as a coding scheme for DNA sequences and study the mutual dependence between such classes. The same analysis is carried out also on the chemical dichotomies of DNA bases. In both cases, the statistical analysis is performed by using an entropy-based dependence metric possessing many desirable properties. We obtain meaningful tests for mutual dependence by using suitable resampling techniques. We find strong short-range correlations between certain combinations of dichotomic codon classes. These results support our previous hypothesis that codon classes might play an active role in the organization of genetic information.

Intra-Renal Angiotensin Levels Are Increased in High-Fructose Fed Rats in the Extracorporeal Renal Perfusion Model.

Overconsumption of fructose leads to metabolic syndrome as a result of hypertension, insulin resistance, and hyperlipidemia. In this study, the renal function of animals submitted to high fructose intake was analyzed from weaning to adulthood using in vivo and ex vivo methods, being compared with a normal control group. We investigated in ex vivo model of the role of the renin Angiotensin system (RAS) in the kidney. The use of perfused kidney from animals submitted to 8-week fructose treatment showed that high fructose intake caused metabolic and cardiovascular alterations that were consistent with other studies. Moreover, the isolated perfused kidneys obtained from rats under high fructose diet showed a 33% increase in renal perfusion pressure throughout the experimental period due to increased renal vascular resistance and a progressive fall in the glomerular filtration rate, which reached a maximum of 64% decrease. Analysis of RAS peptides in the high fructose group showed a threefold increase in the renal concentrations of angiotensin I (Ang I) and a twofold increase in angiotensin II (Ang II) levels, whereas no change in angiotensin 1-7 (Ang 1-7) was observed when compared with the control animals. We did not detect changes in angiotensin converting enzyme (ACE) activity in renal tissues, but there is a tendency to decrease. These observations suggest that there are alternative ways of producing Ang II in this model. Chymase the enzyme responsible for Ang II formation direct from Ang I was increased in renal tissues in the fructose group, confirming the alternative pathway for the formation of this peptide. Neprilysin (NEP) the Ang 1-7 forming showed a significant decrease in activity in the fructose vs. control group, and a tendency of reduction in ACE2 activity. Thus, these results suggest that the Ang 1-7 vasodilator peptide formation is impaired in this model contributing with the increase of blood pressure. In summary, rats fed high fructose affect renal RAS, which may contribute to several deleterious effects of fructose on the kidneys and consequently an increase in blood pressure.

Métodos de ensino utilizados por professores de natação infantil / Teaching methods used by children's swimming teachers / Métodos de enseñanza utilizados por professores de natación infantil

Introdução: O ensino da natação infantil tem priorizado a aprendizagem dos quatro nados competitivos. Embora tenham surgido nos últimos anos diversos métodos de ensino, a prática docente dos professores ainda está voltada ao ensino da técnica esportiva por meio de métodos tradicionais. O baixo número de publicações sobre essa temática dificulta o avanço da linha da "pedagogia da natação". Objetivo: Caracterizar os métodos utilizados por professores no ensino da natação infantil. Metodologia: Foi realizada uma pesquisa de abordagem qualitativa e de caráter descritivo, utilizando a técnica de observação não participante. As observações foram registradas com o auxílio de diários de campo. O contexto de investigação foi um estabelecimento no município de Brusque-SC. A seleção dos participantes foi de forma intencional não-probabilista e participaram três professores de natação infantil. Ao todo, foram observadas trinta aulas de quarenta e cinco minutos de duração. Os dados foram analisados através da técnica de análise de conteúdo, com as categorias determinadas a priori: atividades, instrução inicial e feedbacks. Resultados e discussão: Os resultados revelaram que os professores utilizaram a instrução por explicação, o baixo uso de feedback durantes as tarefas e predominaram as atividades técnicas/analíticas. Considerações Finais: Conclui-se que os professores observados priorizam o método de ensino analítico/tecnicista.

Introduction: The teaching of children's swimming has prioritized learning the four competitive swims. Although several teaching methods have emerged in recent years, the teaching practice of teachers is still focused on teaching sports technique through traditional methods. The low number of publications on this topic makes it difficult to advance the line of "swimming pedagogy". Objective: To characterize the methods used by teachers in teaching children's swimming. Methodology: A qualitative and descriptive research was carried out, using the technique of non-participant observation. Observations were recorded with the aid of field diaries. The research context was an establishment in the city of Brusque, Santa Catarina. The selection of participants was intentionally non-probabilistic and three children's swimming teachers participated. In all, thirty classes of forty-five minutes in length were observed. Data were analyzed using the content analysis technique, with the categories determined a priori: activities, initial instruction and feedback. Results and discussion: The results revealed that teachers used instruction by explanation, low use of feedback during tasks and technical/analytical activities predominated. Final Considerations: It is concluded that the observed teachers prioritize the analytical/technical teaching method.

Introducción: La enseñanza de la natación infantil ha priorizado el aprendizaje de los cuatro estilos competitivos. Aunque en los últimos años han surgido varios métodos de enseñanza, la práctica docente de los profesores sigue centrada en la enseñanza de la técnica deportiva a través de métodos tradicionales. El escaso número de publicaciones sobre este tema dificulta avanzar en la línea de la "pedagogía de la natación". Objetivo: Caracterizar los métodos utilizados por los profesores en la enseñanza de la natación infantil. Metodología: Se realizó una investigación cualitativa y descriptiva, utilizando la técnica de observación no participante. Las observaciones se registraron con la ayuda de diarios de campo. El contexto de la investigación fue un establecimiento en la ciudad de Brusque, Santa Catarina. La selección de los participantes fue intencionalmente no probabilística y participaron tres profesores de natación infantil. En total, se observaron treinta clases de cuarenta y cinco minutos de duración. Los datos se analizaron mediante la técnica de análisis de contenido, con las categorías determinadas a priori: actividades, instrucción inicial y retroalimentación. Resultados y discusión: Los resultados revelaron que los docentes utilizaron la instrucción por explicación, predominó el bajo uso de la retroalimentación durante las tareas y las actividades técnicas / analíticas. Consideraciones finales / Conclusión: Se concluye que los docentes observados priorizan el método de enseñanza analítico / técnico.

Construção e validação preliminar do instrumento de observação para metodologias ativas (io-ma) no ensino dos jogos esportivos coletivos / Construction and preliminary validation of the observation instrument for active methodologies (io-ma) in the teaching team sports

O objetivo do estudo foi construir e validar o Instrumento de Observação para Metodologias Ativas (IO-MA) no ensino dos Jogos Esportivos Coletivos (JEC). Para tanto, foram avaliadas as dimensões Aprendizagem Significativa (AS), Envolvimento Ativo (EA) e Cooperação Social (CS). O desenvolvimento dos indicadores de cada dimensão ocorreu por meio de consulta na literatura especializada. O processo de validação de conteúdo do instrumento foi realizado por onze especialistas doutores com experiência na área da Educação Física. A coleta dos dados ocorreu a partir da análise em vídeo de uma aula de um professor expert. A análise da fidedignidade inter-avaliadores foi realizada por sete avaliadores doutores e ampla experiência na área da Educação Física. Os dados foram analisados aplicando-se o coeficiente V de Aiken para a validação de conteúdo e o índice de concordância Kappa para fidedignidade intra e inter-avaliadores. Os resultados revelaram que o IO-MA obteve altos índices de validade de conteúdo tanto para a avaliação do instrumento global (V=0,88), quanto para as dimensões clareza de linguagem (V=0,84), pertinência prática (V=0,90) e relevância teórica (V=0,91). O IO-MA também apresentou índices considerados quase-perfeitos de fidedignidade intra (Kappa=1,00) e inter-avaliadores (Kappa=1,00). A versão final do IO-MA foi composta por 15 itens/comportamentos distribuídos em três dimensões (AS=6, EA=5, CS=4). Conclui-se que o IO-MA é um instrumento acessível e aplicável para a observação do comportamento de professores e futuros professores no que diz respeito ao uso de metodologias ativas para o ensino dos JEC no contexto brasileiro. (AU)

The aim of the study was to build and validate the Instrument of Observation for Active Methodologies (IO-MA) in the teaching of Collective Sports Games (JEC). Therefore, the dimensions of Meaningful Learning (ML), Active Involvement (AI) and Social Cooperation (SC) were evaluated. The development of indicators for each dimension took place through consultation in the specialized literature. The instrument content validation process was carried out by eleven doctorate-degree specialists with extensive experience in the field of Physical Education. Data collection occurred from video analysis of a class by an expert teacher. Subsequently, the inter-evaluator reliability analysis was carried out by seven doctorate-degree evaluators with extensive experience in the field of Physical Education. Data were analyzed by applying the Aiken V coefficient for content validation and the Kappa agreement index for intra and inter-rater interval reliability. The results showed that the IO-MA obtained high content validity rates both for the instrument in general (V=0,88), and for the dimensions clarity of language (V=0,84), practical relevance (V=0,90), theoretical relevance (V=0,91). The IO-MA also showed near-perfect indices of intra- (Kappa=1,00) and inter-rater (Kappa=1,00) reliability. The final version of the IO-MA was composed of 15 items/behaviors distributed in three dimensions (AS=6, EA=5, CS=4). It is concluded that the IO-MA is an accessible and applicable instrument for the observation of the behavior of teachers and future teachers regarding the use of active methodologies for teaching team sports games in the Brazilian context. (AU)

The non-power model of the genetic code: a paradigm for interpreting genomic information.

In this article, we present a mathematical framework based on redundant (non-power) representations of integer numbers as a paradigm for the interpretation of genomic information. The core of the approach relies on modelling the degeneracy of the genetic code. The model allows one to explain many features and symmetries of the genetic code and to uncover hidden symmetries. Also, it provides us with new tools for the analysis of genomic sequences. We review briefly three main areas: (i) the Euplotid nuclear code, (ii) the vertebrate mitochondrial code, and (iii) the main coding/decoding strategies used in the three domains of life. In every case, we show how the non-power model is a natural unified framework for describing degeneracy and deriving sound biological hypotheses on protein coding. The approach is rooted on number theory and group theory; nevertheless, we have kept the technical level to a minimum by focusing on key concepts and on the biological implications.

Beliefs about constructivist-oriented teaching practices: a study with elementary physical education teachers / Crenças sobre práticas de ensino orientadas ao construtivismo: um estudo com professores de educação física do ensino fundamental

ABSTRACT The aim was to identify the beliefs about teaching practices oriented to constructivism by Elementary Physical Education teachers of the Florianópolis Metropolitan Nucleus in Santa Catarina, Brazil. In this quantitative and descriptive study, 129 Elementary School Physical Education teachers answered a questionnaire to characterize the participants and a translated and adapted version of the Constructivist Teaching Practices Inventory in Elementary Physical Education - CTPI-EPE. Descriptive statistic and binary logistic regression analysis were used, with the aid of the open-source software "R", version 3.6.1. The results revealed that regardless of personal, academic, and professional characteristics, the Physical Education teachers investigated perceive their teaching often oriented towards constructivism. It stands out, teachers with a temporary job often have beliefs related to teaching practices oriented towards general constructivism; teachers who did not participate in courses on sports education have beliefs oriented to the development of social cooperation; and teachers with a temporary employment bond and with a non-degree graduate program had a greater chance of promoting students' personal relevance in their classes.

RESUMO O objetivo do estudo foi identificar as crenças sobre as práticas de ensino orientadas ao construtivismo dos professores de Educação Física do Ensino Fundamental, do Núcleo Metropolitano de Florianópolis, em Santa Catarina, Brasil. Neste estudo quantitativo e descritivo, 129 professores de Educação Física do Ensino Fundamental responderam a um questionário de caracterização dos participantes, e uma versão traduzida e adaptada do Constructivist Teaching Practices Inventory in Elementary Physical Education - CTPI-EPE. Empregaram-se recursos da estatística descritiva e a análise de regressão logística binária, com o auxílio do software de código aberto "R", versão 3.6.1. Os resultados revelaram que, independente das características pessoais, acadêmicas e profissionais, os professores de Educação Física investigados percebem o ensino frequentemente orientado ao construtivismo. Ressalta-se que os professores com vínculo empregatício temporário apresentam crenças relacionadas às práticas de ensino voltadas ao construtivismo geral; os que não participaram de cursos sobre o ensino dos esportes, crenças quanto ao desenvolvimento da cooperação social; e os com vínculo temporário e pós-graduação lato sensu apresentaram maiores chances de promover a relevância pessoal dos estudantes em aula.

Diabetic Nephropathy Induced by Increased Ace Gene Dosage Is Associated with High Renal Levels of Angiotensin (1-7) and Bradykinin.

Population studies have shown an association between diabetic nephropathy (DN) and insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene (ACE in humans, Ace in mice). The aim was to evaluate the modulation of Ace copies number and diabetes mellitus (DM) on renal RAS and correlate it with indicators of kidney function. Increased number of copies of the Ace gene, associated with DM, induces renal dysfunction. The susceptibility to the development of DN in 3 copies of animals is associated with an imbalance in activity of RAS enzymes leading to increased synthesis of Ang II and Ang-(1-7). Increased concentration of renal Ang-(1-7) appears to potentiate the deleterious effects triggered by Ang II on kidney structure and function. Results also show increased bradykinin concentration in 3 copies diabetic group. Taken together, results indicate that the deleterious effects described in 3 copies diabetic group are, at least in part, due to a combination of factors not usually described in the literature. Thus, the data presented here show up innovative and contribute to understanding the complex mechanisms involved in the development of DN, in order to optimize the treatment of patients with this complication.

Genome characterization through dichotomic classes: an analysis of the whole chromosome 1 of A. thaliana.

In this article we show how dichotomic classes, binary variables naturally derived from a new mathematical model of the genetic code, can be used in order to characterize different parts of the genome. In particular, we analyze and compare different parts of whole chromosome 1 of Arabidopsis thaliana: genes, exons, introns, coding sequences (CDS), intergenes, untranslated regions (UTR) and regulatory sequences. In order to accomplish the task we encode each sequence in the 3 possible reading frames according to the definitions of the dichotomic classes (parity, Rumer and hidden). Then, we perform a statistical analysis on the binary sequences. Interestingly, the results show that coding and non-coding sequences have different patterns and proportions of dichotomic classes. This suggests that the frame is important only for coding sequences and that dichotomic classes can be useful to recognize them. Moreover, such patterns seem to be more enhanced in CDS than in exons. Also, we derive an independence test in order to assess whether the percentages observed could be considered as an expression of independent random processes. The results confirm that only genes, exons and CDS seem to possess a dependence structure that distinguishes them from i.i.d sequences. Such informational content is independent from the global proportion of nucleotides of a sequence. The present work confirms that the recent mathematical model of the genetic code is a new paradigm for understanding the management and the organization of genetic information and is an innovative tool for investigating informational aspects of error detection/correction mechanisms acting at the level of DNA replication.

The Merli-Missiroli-Pozzi Two-Slit Electron-Interference Experiment.

In 2002 readers of Physics World voted Young's double-slit experiment with single electrons as "the most beautiful experiment in physics" of all time. Pier Giorgio Merli, Gian Franco Missiroli, and Giulio Pozzi carried out this experiment in a collaboration between the Italian Research Council and the University of Bologna almost three decades earlier. I examine their experiment, place it in historical context, and discuss its philosophical implications.

DNA, dichotomic classes and frame synchronization: a quasi-crystal framework.

In this article, we show how a new mathematical model of the genetic code can be exploited for investigating the almost periodic properties of DNA and mRNA protein-coding sequences. We present the main mathematical features of the model and highlight its connections with both number theory and group theory. The group theoretic framework presents interesting analogies with the theory of crystals. Moreover, we exploit the information provided by dichotomic classes, binary variables naturally derived from the mathematical model, in order to build statistical classifiers for retrieving and predicting the normal reading frame used by the ribosome in protein synthesis. The results show that coding sequences possess a local informational structure that can be related to frame synchronization processes. The information for retrieving the normal reading frame, which implies the existence of short-range correlations and almost periodic structures related to the organization of codons, offers an interesting analogy with the properties of quasi-crystals. From a theoretical point of view, our results might contribute to clarifying the relation between biological information and shape in nucleic acids and proteins. Also, from the point of view of applications, we present new promising tools for designing efficient algorithms for frame synchronization, which plays a crucial role in faithful synthesis of proteins.

O atletismo como conteúdo vai à escola: olhares discentes sobre a experiência de ensino / Athletics becomes school content: students'perceptions on teaching experience / El atletismo como contenido va a la escuela: percepciones de los estudiantes sobre la práctica de enseñanza

O estudo trata das percepções dos alunos acerca do conteúdo Atletismo e sua relação com competências pessoais e sociais na Escola. Participaram do estudo 20 alunos de uma turma do ensino fundamental de uma escola pública. Foram ministradas 24 sessões nas aulas de Educa- ção Física, utilizando à técnica de grupo focal. Os alunos desconheciam o atletismo e apresen- tavam interpretações confusas sobre o tema. A prática do atletismo foi importante para seus aspectos pessoais contribuindo para ampliação das relações interpessoais. Concluiu-se que o conteúdo ensinado pode ser desenvolvido no ambiente escolar, desmistificando o olhar indi- vidual sobre a modalidade, causando entusiasmo quando oportunizado ludicamente e respei- tando as possibilidades de formação de cada indivíduo.

The study deals with the perceptions of students about the Athletics content and its relation to personal and social skills in school. The study included 20 students of an elementary educa- tion class in a public school. 24 sessions in Physical Education classes were held, using the focus group technique. Students were unaware of athletics and had confused interpretations of the theme. The practice of athletics was important for personal aspects contributing to the expansion of interpersonal relationships. It was concluded that the content taught can be de- veloped in the school environment, demystifying the individual look on the modality, causing enthusiasm when developed playfully and respecting each individual's educational possibili- ties.

El estudio se ocupa de las percepciones de los estudiantes sobre el contenido curricular del atletismo y su relación con las habilidades personales y sociales en la escuela. El estudio in- cluyó 20 estudiantes de una clase de educación primaria, de una escuela pública. Fueron da- das 24 clases de Educación Física, utilizando la técnica de grupo focal. Los estudiantes des- conocían el atletismo y tenían interpretaciones confusas sobre el tema. La práctica del atletis- mo fue importante para los estudiantes, pues contribuyó para que algunos aspectos personales contribuyan con la expansión de las relaciones interpersonales. Se concluyó que el contenido que se enseñó puede ser desarrollado en el entorno escolar, desmitificando las percepciones individuales sobre la modalidad y, causando entusiasmo cuando se ofrece de forma lúdica y respetando las oportunidades de formación de cada individuo.