212 research outputs found
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
Residue Analysis of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Soybean Using Liquid Chromatography Coupled with Tandem Mass Spectrometry
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
Three Wide-Separation L dwarf Companions from the Two Micron All Sky Survey: Gl 337C, Gl 618.1B, and HD 89744B
We present two confirmed wide separation L-dwarf common proper motion
companions to nearby stars and one candidate identified from the Two Micron All
Sky Survey. Spectral types from optical spectroscopy are L0 V, L2.5 V, and L8
V. Near-infrared low resolution spectra of the companions are provided as well
as a grid of known objects spanning M6 V -- T dwarfs to support spectral type
assignment for these and future L-dwarfs in the z'JHK bands. Using published
measurements, we estimate ages of the companions from physical properties of
the primaries. These crude ages allow us to estimate companion masses using
theoretical low-mass star and brown dwarf evolutionary models. The new L-dwarfs
in this paper bring the number of known wide-binary (Separation >= 100 AU)
L-dwarf companions of nearby stars to nine. One of the L-dwarfs is a wide
separation companion to the F7 IV-V + extrasolar planet system HD89744Ab.Comment: 20 pages including 6 tables and 4 figures, AJ, in pres
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