Search results for "selection"

Dendrochronologie : potentialités et nouveaux enjeux pour l’archéologie préventive

2019

International audience; La dendrochronologie, méthode de datation qui étudie la variation des largeurs des cernes de croissance des arbres, est sollicitée, en archéologie, pour l’obtention d’une date absolue. Elle nécessite un dialogue incontournable entre les différents acteurs de la discipline pour fiabiliser les acquisitions, voire tout simplement obtenir une date. L’analyse des bois archéologiques ne se limite toutefois pas à la seule datation et constitue le point de départ de nouvelles approches qui permettent de combler des espaces et des champs de recherche encore lacunaire, pour le sud de la France notamment. Dans le contexte des changements climatiques actuels, la dendrochronologi…

Artificial selection of microbial communities: the effect of diversity and the role of interspecific interactions

2021

In agriculture, the plants and animals that are bred come from long-term artificial selection procedures that aim at producing individuals with desirable traits. Such procedures can be applied at levels of biological organization higher than the individual such as the community level, which is of particular interest in the field of microbial community engineering. Indeed, microbial communities play key roles in agriculture but also in the environment, health and industry, and a growing body of literature shows promising results regarding the artificial selection of microbial communities for desirable functions. However, for artificial selection procedures at the community level to be effici…

Genomic divergence landscape in recurrently hybridizing Chironomus sister taxa suggests stable steady state between mutual gene flow and isolation

2021

Abstract Divergence is mostly viewed as a progressive process often initiated by selection targeting individual loci, ultimately resulting in ever increasing genomic isolation due to linkage. However, recent studies show that this process may stall at intermediate stable equilibrium states without achieving complete genomic isolation. We tested the extent of genomic isolation between two recurrently hybridizing nonbiting midge sister taxa, Chironomus riparius and Chironomus piger, by analyzing the divergence landscape. Using a principal component‐based method, we estimated that only about 28.44% of the genomes were mutually isolated, whereas the rest was still exchanged. The divergence land…

BETWEEN SUBJECTIVE AND OBJECTIVE IN MAKING DECISIONS ON THE ROMANIAN HIGHER EDUCATION MARKET

2012

Having roots in intentional behaviours, adverse selection as part of information asymmetry is a widely - discussed concept, closely related to many sides of economics and generating the most various problems in practice. As the specific literature says, the adverse selection leads, or at least in theory should lead to market failure when no external force comes to balance its effects. Since this failure never occurs in fact, it is questionable whether the adverse selection is the only factor that influences an uniformed consumer decision, or other factors come to counterbalance the factors described by Akerloff. This paper intends to advocate the idea that as much as adverse selection, ther…

A New Feature Selection Methodology for K-mers Representation of DNA Sequences

2015

DNA sequence decomposition into k-mers and their frequency counting, defines a mapping of a sequence into a numerical space by a numerical feature vector of fixed length. This simple process allows to compare sequences in an alignment free way, using common similarities and distance functions on the numerical codomain of the mapping. The most common used decomposition uses all the substrings of a fixed length k making the codomain of exponential dimension. This obviously can affect the time complexity of the similarity computation, and in general of the machine learning algorithm used for the purpose of sequence analysis. Moreover, the presence of possible noisy features can also affect the…

Unstable feature relevance in classification tasks

2011

Sourdough and cereal-based foods: traditional and innovative products

2017

Cereals represent the main crop of the five continents and contribute greatly to the diet of several populations. Cereals often undergo a fermentation before eating. This process is fundamental to confer high sensory quality, as well as to preserve and enhance the nutritional and safety aspects of the resulting products. Fermented cereal based foods are complex microbial ecosystems, mainly represented by lactic acid bacteria and yeasts. Among these products, sourdough is worldwide applied to produce breads. Sourdough technology is also used to improve the final characteristics of fortified and gluten–free breads. This chapter focuses on the use of cereals to produce the most relevant fermen…

UPDATE ON THE SICILIAN STRAWBERRY BREEDING PROJECT

2014

The strawberry industry in Sicily differs from that of Italy’s other southern regions since the particularly warm winter weather results in earlier fruit ripening. Cultivar choice is thus of key importance for the success of Sicily’s strawberry industry. The old cultivar Tudla®Milsei has recently been replaced by cultivars ‘Florida Fortuna’, ‘Florida Festival’, ‘Sabrosa®Candonga’, ‘Naiad®Civl35’ and ‘Nora’ developed by both public and private breeding programs in Florida, Spain and Italy. The strawberry breeding program in Sicily started about 20 years ago in an effort to develop new cultivars well adapted to an area of very low winter chilling, with requirements featuring superior performa…

Substratum recognition as settlement cue for larvae of Dendropoma cristatum (Biondi, 1859)

2017

Despite the ecological relevance of the vermetid bioconstructions in the Mediterranean, little is known about the early life stage of Dendropoma cristatum. This study describes the preference for settlement substrata from D. cristatumlarvae. A field experiment was carried out to test the suitability of crustose coralline algae (CCA), D. cristatumadults and two inorganic substrata as settlement surfaces. The number of settling larvae varied among the four treatments with higher settlement success on organic surfaces. CCA and D. cristatumindividuals seem to promote attachment of young larvae and to induce the metamorphosis in recruits. This is probably due to biological or physical properties…

MODELLING VAGUE KNOWLEDGE FOR DECISION SUPPORT IN PLANNING ARCHAEOLOGICAL PROSPECTIONS

2012

Abstract. Most archaeological predictive models lack significance because fuzziness of data and uncertainty in knowledge about human behaviour and natural processes are hardly ever considered. One possibility to cope with such uncertainties is utilization of probability based approaches like Bayes Theorem or Dempster-Shafer-Theory. We analyzed an area of 50 km2 in Rhineland Palatinate (Germany) near a Celtic oppidum by use of Dempster-Shafer's theory of evidence for predicting spatial probability distribution of archaeological sites. This technique incorporates uncertainty by assigning various weights of evidence to defined variables, in that way estimating the probability for supporting a …