Search results for "Quantitative"
showing 10 items of 2409 documents
Mpdz is a quantitative trait gene for drug withdrawal seizures
2004
Physiological dependence and associated withdrawal episodes can constitute a powerful motivational force that perpetuates drug use and abuse. Using robust behavioral models of drug physiological dependence in mice, positional cloning, and sequence and expression analyses, we identified an addiction-relevant quantitative trait gene, Mpdz. Our findings provide a framework to define the protein interactions and neural circuit by which this gene's product (multiple PDZ domain protein) affects drug dependence, withdrawal and relapse.
Biopartitioning micellar separation methods: modelling drug absorption
2003
The search for new pharmacologically active compounds in drug discovery programmes often neglects biopharmaceutical properties as drug absorption. As a result, poor biopharmaceutical characteristics constitute a major reason for the low success rate for candidates in clinical development. Since the cost of drug development is many times larger than the cost of drug discovery, predictive methodologies aiding the selection of bioavailable drug candidates are of profound significance. This paper has been focussed on recent developments and applications of chromatographic systems, particularly those systems based on amphiphilic structures, in the frame of alternative approaches for estimating t…
Inferring slowly-changing dynamic gene-regulatory networks
2015
Dynamic gene-regulatory networks are complex since the interaction patterns between their components mean that it is impossible to study parts of the network in separation. This holistic character of gene-regulatory networks poses a real challenge to any type of modelling. Graphical models are a class of models that connect the network with a conditional independence relationships between random variables. By interpreting these random variables as gene activities and the conditional independence relationships as functional non-relatedness, graphical models have been used to describe gene-regulatory networks. Whereas the literature has been focused on static networks, most time-course experi…
Hub-Centered Gene Network Reconstruction Using Automatic Relevance Determination
2012
Network inference deals with the reconstruction of biological networks from experimental data. A variety of different reverse engineering techniques are available; they differ in the underlying assumptions and mathematical models used. One common problem for all approaches stems from the complexity of the task, due to the combinatorial explosion of different network topologies for increasing network size. To handle this problem, constraints are frequently used, for example on the node degree, number of edges, or constraints on regulation functions between network components. We propose to exploit topological considerations in the inference of gene regulatory networks. Such systems are often…
Overload breakdown in models for photosynthesis
2015
In many models of the Calvin cycle of photosynthesis it is observed that there are solutions where concentrations of key substances belonging to the cycle tend to zero at late times, a phenomenon known as overload breakdown. In this paper we prove theorems about the existence and non-existence of solutions of this type and obtain information on which concentrations tend to zero when overload breakdown occurs. As a starting point we take a model of Pettersson and Ryde-Pettersson which seems to be prone to overload breakdown and a modification of it due to Poolman which was intended to avoid this effect.
Dynamique Industrielle et Internationalisation des entreprises en France
2022
Les revendications politiques habituelles mettent en avant la sélection des entreprises, la réallocation des ressources ainsi que les parts de marché des entreprises les moins efficaces vers les plus productives comme principales sources de croissance de la productivité. La littérature empirique initiée par la « nouvelle » théorie du commerce, a identifié l’exposition et l’accès aux marchés étrangers comme des moteurs importants de ces deux sources de dynamique industrielle. C’est pourquoi, nous nous intéressons aux liens entre la dynamique industrielle et l’internationalisation des entreprises en mettant l’accent sur le rôle de l’innovation. L’objectif de cette étude est de mesurer la croi…
Les ressources des étudiants: mesures, inégalités et vulnérabilités
2019
International audience
Split decomposition A technique to analyze viral evolution
1993
A clustering technique allowing a restricted amount of overlapping and based on an abstract theory of coherent decompositions of finite metrics is used to analyze the evolution of foot-and-mouth disease viruses. The emerging picture is compatible with the existence of viral populations with a quasispecies structure and illustrates various forms of evolution of this virus family. In addition, it allows the correlation of these forms with geographic occurrence.
Automated analysis of images for molecular quantification in immunohistochemistry.
2018
The quantification of the expression of different molecules is a key question in both basic and applied sciences. While protein quantification through molecular techniques leads to the loss of spatial information and resolution, immunohistochemistry is usually associated with time-consuming image analysis and human bias. In addition, the scarce automatic software analysis is often proprietary and expensive and relies on a fixed threshold binarization. Here we describe and share a set of macros ready for automated fluorescence analysis of large batches of fixed tissue samples using FIJI/ImageJ. The quantification of the molecules of interest are based on an automatic threshold analysis of im…
¿Qué aprenden unos estudiantes en una experiencia formativa de Didáctica de las Ciencias Experimentales en el Grado de Educación Infantil?
2020
Esta investigación pretende conocer si evolucionan los conocimientos iniciales de unas maestras de Educación Infantil en su formación inicial en el ámbito de la didáctica de las ciencias. La experiencia se realizó con estudiantes de 3º del Grado de Educación Infantil, tras trabajar la propuesta “Cómo enseñar el cuerpo humano y los hábitos saludables en Educación Infantil”. Se utilizó un diseño cuantitativo no experimental con pretest y postest. Los resultados ponen de manifiesto los logros conseguidos, pero también revelan, de modo preocupante, las carencias con la que llegan y la insuficiente evolución tras esta primera intervención. Esto supone una llamada de atención para plantearnos qué…