782 research outputs found
Epigenetic aberrations and cancer
The correlation between epigenetic aberrations and disease underscores the importance of epigenetic mechanisms. Here, we review recent findings regarding chromatin modifications and their relevance to cancer
Raters as scale makers for an L2 Spanish speaking test: using paired test discourse to develop a rating scale for communicative interaction
This paper reports on the development of an evidence based rating scale to rate peer-peer L2 communicative interaction. The scale was based on experienced judges' comments on videoed student samples filmed during operational paired candidate tests of beginner level Spanish. Six trained and experienced raters generated criteria for communicative interaction which were incorporated into a tool for developing sample based rating scales, the Empirically-based, Binarychoice, Boundary-definition (EBB) method (Turner and Upshur, 1996), was adapted for the context. The findings reported on in this article examine the features of paired candidate interaction which raters used to define the boundary between performance levels. Three main criteria emerged as the boundaries used to define levels of interaction: non-verbal interpersonal communication, interactive listening and interactional management. These new notions are evidence of how peer-peer interaction can bee rated and also advance our understanding of the significant features of interaction in this rating context
Framework for software architecture visualization assessment.
In order to assess software architecture visualisation strategies, we qualitatively characterize then construct an assessment framework with 7 key areas and 31 features. The framework is used for evaluation and comparison of various strategies from multiple stakeholder perspectives. Six existing software architecture visualisation tools and a seventh research tool were evaluated. All
tools exhibited shortcomings when evaluated in the framework
Untangling Fine-Grained Code Changes
After working for some time, developers commit their code changes to a
version control system. When doing so, they often bundle unrelated changes
(e.g., bug fix and refactoring) in a single commit, thus creating a so-called
tangled commit. Sharing tangled commits is problematic because it makes review,
reversion, and integration of these commits harder and historical analyses of
the project less reliable. Researchers have worked at untangling existing
commits, i.e., finding which part of a commit relates to which task. In this
paper, we contribute to this line of work in two ways: (1) A publicly available
dataset of untangled code changes, created with the help of two developers who
accurately split their code changes into self contained tasks over a period of
four months; (2) a novel approach, EpiceaUntangler, to help developers share
untangled commits (aka. atomic commits) by using fine-grained code change
information. EpiceaUntangler is based and tested on the publicly available
dataset, and further evaluated by deploying it to 7 developers, who used it for
2 weeks. We recorded a median success rate of 91% and average one of 75%, in
automatically creating clusters of untangled fine-grained code changes
From image to technology: a multidisciplinary approach for improving the quality of organic bread.
This study is part of a research programme devoted to improving the quality of organic bread. It aims to identify and test prototypes of breads approved by consumers. This is achieved by analysing consumer representations and preferences and placing them within the framework of technological, sensory and nutritional dimensions of the products. The multidisciplinary approach implements an original qualitative approach that combines three consumer focus groups made up of both loyal and occasional consumers, and confrontation sessions with the programme scientific partners. Four prototypes of organic breads have thus been formalised and subsequently tested on a sample of 120 consumers from two sites (Angers and Strasbourg). From an operational point of view, proposals for organic breads approved by consumers are formulated. In terms of methodology, the contributions of a multidisciplinary study are discussed
Estimating the number of contributors to two-, three-, and four-person mixtures containing DNA in high template and low template amounts
Aim To develop guidelines to estimate the number of contributors
to two-, three-, and four-person mixtures containing
either high template DNA (HT-DNA) or low template
DNA (LT-DNA) amounts.
Methods Seven hundred and twenty-eight purposeful
two-, three-, and four-person mixtures composed of 85
individuals of various ethnicities with template amounts
ranging from 10 to 500 pg were examined. The number
of alleles labeled at each locus and the number of labeled
different and repeating alleles at each locus as well over all
loci for 2 HT-DNA or 3 LT-DNA replicates were determined.
Guidelines based on these data were then evaluated with
117 mixtures generated from items handled by known individuals.
Results The number of different alleles over all loci and
replicates was used to initially categorize mixtures. Ranges
were established based on the averages plus and minus
2 standard deviations, and to encompass all observations,
the maximum and the minimum values. To differentiate
samples that could be classified in more than one grouping,
the number of loci with 4 or more repeating or different
alleles, which were specific to three- and four-person
mixtures, were verified. Misclassified samples showed an
extraordinary amount of allele sharing or stutter.
Conclusions These guidelines proved to be useful tools to
distinguish low template and high template two-, three-,
and four-person mixtures. Due to the inherent higher
probability of allele sharing, four-person mixtures were
more challenging. Because of allelic drop-out, this was also
the case for samples with very low amounts of template
DNA or extreme mixture ratios
Mechanical tests and definition of new indexes of grape berry firmness. Evolution of berry skin hardness during alcoholic fermentation
The mechanical strength or firmness of a fruit is considered an important parameter to characterise its state of ripeness or conservation, as well as other parameters such as sugar level or color. The mechanical hardness of grapes influences the integrity and sanitary quality of the harvest. In this study, the mechanical characteristics of grapevine berries were studied at harvest time in order to determine their rheological properties (firmness and hardness of the berry skin) during alcoholic fermentation. Special indexes were defined measuring the energy needed to crush the berries to 50 % of their initial diameter, and applied successively to two different varieties. The entire berry firmness and the skin hardness were both different. Mechanical indexes linked to grape firmness were defined. Using these indexes, a significant effect on the firmness behavior due to variety was recorded: the skin of 'Grenache Noir' was found firmer and harder than 'Carignan Noir'. Furthermore, during the alcoholic fermentation, no change in skin hardness was observed for both varieties, despite changes in the composition of the must. These results give new information on mechanical properties of berries and could be used as an aid in the winemaking process. Indeed, they would probably help the winemaker to better choose the type of fermentation and maceration adapted to his grapes according to the type of wine he wishes to produce
Frequency estimation : Survey of parametric methods
This paper is a survey of parametric modeling applied to frequency estimation of sinusoidal signals corrupted by an additive noise .
A summary of major estimation methods using second or higher order statistics is presented . Discussed techniques include classica l
AR modeling (based on Yule-Walker equations) and "High Resolution" methods (Truncated SVD, Root-MUSIC and ESPRIT) . Th e
maximum likelihood estimator and Bayesian methods are also under interest . But the selection of the model order in these method s
is often a critical one . Thus major model order estimation methods are reviewed . Finally, the efficiency of each method is examined
through a simulation example .Le but de cet article est de dresser un panorama des méthodes paramétriques appliquées à l'estimation de fréquences de signaux sinusoïdaux bruités (bruit additif). Nous rappelons les principales méthodes d'estimation basées sur les moments du signal : méthodes classiques déduites des équations de Yule-Walker et méthodes « Haute Résolution » (SVD tronquée, Root-MUSIC et ESPRIT). Nous présentons aussi l'estimateur du maximum de vraisemblance et l'estimation Bayésienne. L'efficacité de ces méthodes étant souvent liée au choix de l'ordre du modèle, nous rappelons les principaux estimateurs de l'ordre. Enfin, une comparaison des méthodes met en évidence les performances de chacune
Scissors resonance in the quasi-continuum of Th, Pa and U isotopes
The gamma-ray strength function in the quasi-continuum has been measured for
231-233Th, 232,233Pa and 237-239U using the Oslo method. All eight nuclei show
a pronounced increase in gamma strength at omega_SR approx 2.4 MeV, which is
interpreted as the low-energy M1 scissors resonance (SR). The total strength is
found to be B_SR = 9-11 mu_N^2 when integrated over the 1 - 4 MeV gamma-energy
region. The SR displays a double-hump structure that is theoretically not
understood. Our results are compared with data from (gamma, gamma') experiments
and theoretical sum-rule estimates for a nuclear rigid-body moment of inertia.Comment: 11 pages, 9 figure
Transcriptome analysis of mycorrhizal and nonmycorrhizal soybean plantlets upon infection with Fusarium virguliforme, one causal agent of sudden death syndrome
Soilborne pathogens represent a threat to agriculture causing important yield losses. Sudden death syndrome (SDS) of soybean is a severe disease caused by a complex of Fusarium species. This pathosystem has been widely investigated and several strategies have been proposed to manage SDS. Although a decrease in symptoms and in the level of root tissue infection, particularly by F. virguliforme, was observed in the presence of arbuscular mycorrhizal fungi (AMF), biological control based on AMF has received less attention. Here, the results are reported of transcriptional analysis of mycorrhizal versus nonmycorrhizal soybean plantlets infected by F. virguliforme, grown under strict in vitro culture experimental conditions. Important transcriptional reprogramming was detected following infection by the pathogen. Results revealed 1768 and 967 differentially expressed genes in the AMF-colonized (+AMF+Fv) and noncolonized (−AMF+Fv) plants, respectively. Major transcriptional changes corresponded to defence response-related genes belonging to secondary metabolism, stress and signalling categories. The +AMF+Fv treatment showed the largest number of up-regulated genes related to defence, such as those encoding disease resistance proteins, WRKY transcription factors, auxins, receptors kinases and proteases. Only a few genes had primed expression in the +AMF+Fv treatment, such as those encoding a thaumatin-like protein (TLP) and a pleiotropic drug resistance (PDR) protein. Moreover, +AMF+Fv showed a significantly greater number of down-regulated genes related to cell wall modification and peroxidases than the –AMF+Fv treatment. This detailed investigation increases knowledge of transcriptional changes and potential metabolic pathways involved in the enhanced resistance or tolerance of mycorrhizal plants to infection by F. virguliforme.Fil: Marquez, Nathalie. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatologia y Modelizacion Agricola. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Fitopatologia y Modelizacion Agricola.; ArgentinaFil: Giachero, María Lorena. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gallou, A.. Centro Nacional de Referencia de Control Biológico; MéxicoFil: Debat, Humberto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Declerck, S,. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Ducasse, Daniel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentin
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