Dynamic Bayesian networks in molecular plant science: inferring gene regulatory networks from multiple gene expression time series

To understand the processes of growth and biomass production in plants, we ultimately need to elucidate the structure of the underlying regulatory networks at the molecular level. The advent of high-throughput postgenomic technologies has spurred substantial interest in reverse engineering these networks from data, and several techniques from machine learning and multivariate statistics have recently been proposed. The present article discusses the problem of inferring gene regulatory networks from gene expression time series, and we focus our exposition on the methodology of Bayesian networks. We describe dynamic Bayesian networks and explain their advantages over other statistical methods. We introduce a novel information sharing scheme, which allows us to infer gene regulatory networks from multiple sources of gene expression data more accurately. We illustrate and test this method on a set of synthetic data, using three different measures to quantify the network reconstruction accuracy. The main application of our method is related to the problem of circadian regulation in plants, where we aim to reconstruct the regulatory networks of nine circadian genes in Arabidopsis thaliana from four gene expression time series obtained under different experimental conditions

Heterogeneous continuous dynamic Bayesian networks with flexible structure and inter-time segment information sharing

Classical dynamic Bayesian networks (DBNs) are based on the homogeneous Markov assumption and cannot deal with heterogeneity and non-stationarity in temporal processes. Various approaches to relax the homogeneity assumption have recently been proposed. The present paper aims to improve the shortcomings of three recent versions of heterogeneous DBNs along the following lines: (i) avoiding the need for data discretization, (ii) increasing the flexibility over a time-invariant network structure, (iii) avoiding over-flexibility and overfitting by introducing a regularization scheme based in inter-time segment information sharing. The improved method is evaluated on synthetic data and compared with alternative published methods on gene expression time series from Drosophila melanogaster. 1

BIOMECHANICAL ANALYSIS OF TWO DIFFERENT JUMPS IN RHYTHMIC SPORTS GYMNASTIC(RSG)

INTRODUCTION - The aim of this study Table was to analyse the different techniques used by RSG gymnasts to perform two jumps: the leap jump, and the leap jump with trunk extension (figure 1 -A and B). Twelve high level RSG gymnasts aged 15k3.2 yrs. 49.424.7Kg weight and 167.2+.6.8cm height were observed. Each gymnast performed the two different jumps.The parameters observed were: velocity of Center of Mass (CM) on take off and landing; duration, high and length of the jumps, and the high of the CM in differents moments of the jump (take off, highest point and landing). The jumps were filmed and analysed using the Peak5 - Motion Measurents System with a 16 points spacial model. RESULTS- The main results are resumed in table 1. CONCLUSIONS-Observing the results we could conclude :hat, nevertheless the A jump was an easy one, the gymnasts performed B jump with a high technical quality, since the jump is better it is performed the highest, longest and during more time The results showed also that probably gymnasts did not performed A jump the best way that could. This is an important remark to the coaches because many times gymnasts do not put the same emphasis in easy skills, and the penalties in the completion are the same for easy and for very difficult skill

Pão com elevado teor em amido resistente enriquecido com farinha de grão-de-bico

O pão é um alimento base e uma das mais importantes fontes de hidratos de carbono da dieta dos portugueses. Contém pequenas quantidades de amido resistente (AR) mas, de acordo com diversos estudos, é possível fomentar a sua formação durante o processo de fabrico. O AR, definido como a soma do amido e produtos da sua degradação que não são absorvidos no intestino delgado, constitui um dos componentes da fibra alimentar. Têm-lhe sido atribuídos diversos benefícios fisiológicos, especialmente em patologias como: doenças intestinais, diabetes, doença cardiovascular, dislipidémias, obesidade e osteoporose. O grão-de-bico é uma leguminosa com elevado teor de proteína relativamente a outros alimentos de origem vegetal, contudo não possui todos os aminoácidos essenciais. Os aminoácidos ausentes no grãode-bico encontram-se em quantidades apreciáveis nos cereais, pelo que a conjugação de leguminosas e cereais origina um produto enriquecido em proteínas completas. Além disso as leguminosas constituem boas fontes de AR o que poderá contribuir para um produto final com um teor mais elevado neste componente. Este trabalho teve como base um estudo anterior em que foi desenvolvido um pão de trigo e milho com um teor em AR 3 vezes superior ao pão comum. O objetivo deste trabalho foi a obtenção de um pão enriquecido em proteína e em AR e o desenvolvimento de uma apresentação apelativa e do agrado do consumidor, sem comprometer o valor nutricional do pão. A partir da fórmula e do processo de fabrico do estudo anterior, foi preparada uma formulação base em que 12,5% da farinha de trigo foi substituída por farinha de grão de bico. A partir desta formulação foram ensaiadas 4 apresentações diferentes: formulação base (PREF); fórmula base em que se alterou a cozedura para 200ºC/30 minutos (P200); formulação base seguida de um tratamento do pão intacto a 200ºC durante 15 minutos (PC) e formulação base seguida de fatiagem e tratamento das fatias a 150ºC durante 30 minutos (PT). Foi realizada uma prova hedónica para avaliar a aceitação global pelos consumidores. Os resultados revelaram que a formulação com maior aceitabilidade global, numa escala de 1 a 5 pontos, foi P200 seguindo-se PC, PREF e por último PT. Relativamente aos restantes parâmetros sensoriais avaliados (cor, aparência, aroma, textura, sabor e flavour) as formulações P200, PC e PREF obtiveram valores médios superiores a 3,0 em cada um dos parâmetros. Quando questionados sobre a apetência de compra para estes produtos, a maioria referiu P200, sendo que PC e PREF também foram indicados por uma percentagem importante de inquiridos. Na continuidade deste trabalho será efetuada a quantificação da proteína, gordura, cinza, fibra e amido resistente de forma a comparar o valor nutricional das 4 variantes em estudo. Para já podemos concluir que foi possível obter variantes de pão enriquecido em AR e proteína que revelaram uma aceitação global satisfatória e que poderão constituir boas alternativas a incluir numa alimentação saudável.info:eu-repo/semantics/publishedVersio

Exposure to diesel exhaust particles increases susceptibility to invasive pneumococcal disease.

BACKGROUND: The World Health Organization estimates that air pollution is responsible for 7 million deaths per annum, with 7% of these attributable to pneumonia. Many of these fatalities have been linked to exposure to high levels of airborne particulates, such as diesel exhaust particles (DEPs). OBJECTIVES: We sought to determine whether exposure to DEPs could promote the progression of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae to invasive pneumococcal disease. METHODS: We used mouse models and in vitro assays to provide a mechanistic understanding of the link between DEP exposure and pneumococcal disease risk, and we confirmed our findings by using induced sputum macrophages isolated from healthy human volunteers. RESULTS: We demonstrate that inhaled exposure to DEPs disrupts asymptomatic nasopharyngeal carriage of S pneumoniae in mice, leading to dissemination to lungs and blood. Pneumococci are transported from the nasopharynx to the lungs following exposure to DEPs, leading to increased proinflammatory cytokine production, reduced phagocytic function of alveolar macrophages, and consequently, increased pneumococcal loads within the lungs and translocation into blood. These findings were confirmed by using DEP-exposed induced sputum macrophages isolated from healthy volunteers, demonstrating that impaired innate immune mechanisms following DEP exposure are also at play in humans. CONCLUSION: Lung inhaled DEPs increase susceptibility to pneumococcal disease by leading to loss of immunological control of pneumococcal colonisation, increased inflammation, tissue damage, and systemic bacterial dissemination

The Na+ -Coupled Glucose Transporter SGLT2 Interacts with its Accessory Unit MAP17 in Vitro and Their expressions overlap in the renal proximal tubule

Na+ -glucose cotransporter 2 is the renal Na+ -coupled glucose transporter responsible for the tubular glucose reabsorption, while MAP17 was recently identified as its accessory unit. Mutations in either of the proteins' coding genes, SLC5A2 and PDZK1IP1, lead to urinary glucose excretion. To investigate whether MAP17 interacts with SGLT2 in vitro, we engineered a V5-tagged SGLT2 construct and evaluated HEK293T cells coexpressing it together with a HA tagged MAP17 construct. MAP17 is shown to colocalize and coimmunoprecipitate with SGLT2. Also, in human kidney sections, the expression of both proteins overlaps at the apical surface of tubular epithelia. This interaction provides the rationale behind SGLT2 activation by MAP17 as well the similarity of the SLC5A2 and PDZK1IP1 glucosuric phenotypes.info:eu-repo/semantics/publishedVersio

Association of the mtDNA m.4171C>A/MT-ND1 mutation with both optic neuropathy and bilateral brainstem lesions

Background: An increasing number of mitochondrial DNA (mtDNA) mutations, mainly in complex I genes, have been associated with variably overlapping phenotypes of Leber’s hereditary optic neuropathy (LHON), mitochondrial encephalomyopathy with stroke-like episodes (MELAS) and Leigh syndrome (LS). We here describe the first case in which the m.4171C>A/MT-ND1 mutation, previously reported only in association with LHON, leads also to a Leigh-like phenotype. Case presentation: A 16-year-old male suffered subacute visual loss and recurrent vomiting and vertigo associated with bilateral brainstem lesions affecting the vestibular nuclei. His mother and one sister also presented subacute visual loss compatible with LHON. Sequencing of the entire mtDNA revealed the homoplasmic m.4171C>A/MT-ND1 mutation, previously associated with pure LHON, on a haplogroup H background. Three additional non-synonymous homoplasmic transitions affecting ND2 (m.4705T>C/MT-ND2 and m.5263C>T/MT-ND2) and ND6 (m.14180T>C/MT-ND6) subunits, well recognized as polymorphisms in other mtDNA haplogroups but never found on the haplogroup H background, were also present. Conclusion: This case widens the phenotypic expression of the rare m.4171C>A/MT-ND1 LHON mutation, which may also lead to Leigh-like brainstem lesions, and indicates that the co-occurrence of other ND non-synonymous variants, found outside of their usual mtDNA backgrounds, may have increased the pathogenic potential of the primary LHON mutation

The evolution of surface magnetic fields in young solar-type stars I: the first 250 Myr

The surface rotation rates of young solar-type stars vary rapidly with age from the end of the pre-main sequence through the early main sequence. Important changes in the dynamos operating in these stars may result from this evolution, which should be observable in their surface magnetic fields. Here we present a study aimed at observing the evolution of these magnetic fields through this critical time period. We observed stars in open clusters and stellar associations of known ages, and used Zeeman Doppler imaging to characterize their complex magnetic large-scale fields. Presented here are results for 15 stars, from five associations, with ages from 20 to 250 Myr, masses from 0.7 to 1.2 M⊙, and rotation periods from 0.4 to 6 d. We find complex large-scale magnetic field geometries, with global average strengths from 14 to 140 G. There is a clear trend towards decreasing average large-scale magnetic field strength with age, and a tight correlation between magnetic field strength and Rossby number. Comparing the magnetic properties of our zero-age main-sequence sample to those of both younger and older stars, it appears that the magnetic evolution of solar-type stars during the pre-main sequence is primarily driven by structural changes, while it closely follows the stars’ rotational evolution on the main sequence