Search results for "making"
showing 10 items of 1218 documents
Interactivized : Visual Interaction for Better Decisions with Interactive Multiobjective Optimization
2022
In today’s data-driven world, decision makers are facing many conflicting objectives. Since there is usually no solution that optimizes all objectives simultaneously, the aim is to identify a solution with acceptable trade-offs. Interactive multiobjective optimization methods are iterative processes in which a human decision maker repeatedly provides one’s preferences to request computing new solutions and compares them. With these methods, the decision maker can learn about the problem and its limitations. However, advanced optimization software usually offer simple visualization tools that can be significantly improved. On the other hand, current approaches for multiobjective optimization…
Molecular Characterization of a Chromosomal Rearrangement Involved in the Adaptive Evolution of Yeast Strains
2002
Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, is the product of a reciprocal translocation between chromosomes VIII and XVI due to unequal crossing-over mediated by microhomology between very short sequences on the 5' upstream regions of the SSU1 and ECM34 genes. We also show that this translocation is only present in wine yeast strains, suggesting that the use for millennia of sulfite as a preservative in wine production could have favored …
Adaptive response to wine selective pressures shapes the genome of a Saccharomyces interspecies hybrid
2021
During industrial processes, yeasts are exposed to harsh conditions, which eventually lead to adaptation of the strains. In the laboratory, it is possible to use experimental evolution to link the evolutionary biology response to these adaptation pressures for the industrial improvement of a specific yeast strain. In this work, we aimed to study the adaptation of a wine industrial yeast in stress conditions of the high ethanol concentrations present in stopped fermentations and secondary fermentations in the processes of champagne production. We used a commercial Saccharomyces cerevisiae × S. uvarum hybrid and assessed its adaptation in a modified synthetic must (M-SM) containing high ethan…
A novel approach for the improvement of stress resistance in wine yeasts
2006
During wine production yeast cells are affected by several stress conditions that could affect their viability and fermentation efficiency. In this work we describe a novel genetic manipulation strategy designed to improve stress resistance in wine yeasts. This strategy involves modifying the expression of the transcription factor MSN2, which plays an important role in yeast stress responses. The promoter in one of the genomic copies of this gene has been replaced by the promoter of the SPI1 gene, encoding for a cell wall protein of unknown function. SPI1 is expressed at late phases of growth and is regulated by Msn2p. This modification allows self-induction of MSN2 expression. MSN2 gene tr…
Genetic manipulation of HSP26 and YHR087W stress genes may improve fermentative behaviour in wine yeasts under vinification conditions
2008
Throughout wine production yeast cells are affected by a plethora of stress conditions that compromise their ability to carry out the whole process. In recent years important knowledge about the mechanisms involved in stress response in both laboratory and wine yeast strains has been obtained. Several studies have indicated that a correlation exists between stress resistance, expression of stress response genes and fermentative behaviour. In this work we introduce several genetic manipulations in two genes induced by several stress conditions: HSP26 (which encodes a heat shock protein) and YHR087W (encoding a protein of unknown function) in two different wine yeasts, ICV16 and ICV27. These …
Evaluation of different genetic procedures for the generation of artificial hybrids in Saccharomyces genus for winemaking
2012
Several methods based on recombinant DNA techniques have been proposed for yeast strain improvement; however, the most relevant oenological traits depend on a multitude of loci, making these techniques difficult to apply. In this way, hybridization techniques involving two complete genomes became interesting. Natural hybrid strains between different Saccharomyces species have been detected in diverse fermented beverages including wine, cider and beer. These hybrids seem to be better adapted to fluctuating situations typically observed in fermentations due to the acquisition of particular physiological properties of both parental strains. In this work we evaluated the usefulness of three dif…
Comparative Transcriptomic Analysis Reveals Similarities and Dissimilarities in Saccharomyces cerevisiae Wine Strains Response to Nitrogen Availabili…
2015
Nitrogen levels in grape-juices are of major importance in winemaking ensuring adequate yeast growth and fermentation performance. Here we used a comparative transcriptome analysis to uncover wine yeasts responses to nitrogen availability during fermentation. Gene expression was assessed in three genetically and phenotypically divergent commercial wine strains (CEG, VL1 and QA23), under low (67 mg/L) and high nitrogen (670 mg/L) regimes, at three time points during fermentation (12 h, 24 h and 96 h). Two-way ANOVA analysis of each fermentation condition led to the identification of genes whose expression was dependent on strain, fermentation stage and on the interaction of both factors. The…
Physiological properties of some yeast strains
2006
Twenty yeast strains have recently been isolated in pure cultures from natural and industrial sources and identified based mainly on physiological properties. The majority of the strains (15) are alcohologenic belonging to the genus Saccharomyces and comprise two brewer's (beer) yeast strains (S. carlsbergensis= S. uvarum A and B), two baker's yeast strains (S. cerevisiae CA and CP), one spirit yeast strain (S. cerevisiae CF) and ten wine yeast strains (S. cerevisiae var. ellipsoideus = S. ellipsoideus 1, 3, 4, 6, 8 and 9; S. oviformis 2, 5 and 7; and S. uvarum 10). The other 5 yeast strains belong to different species: Kloeckera apiculate, Candida mycoderma (Mycoderma vini), Pichia membran…
Psychomotor speed in a random sample of 7,979 subjects aged 30 years and over.
2011
Background and aims: Slowing of psychomotor speed among older individuals has been shown in numerous studies. However, in most cases these studies were based on small and selected groups of people and, in some cases, the test procedures did not allow separation of decision time and motor components of the overall performance. The purpose of the present study was to analyse in a large, randomly selected population sample the differences in decision and movement times in simple and multiple-choice test conditions. The association of educational background with psychomotor speed was also examined. Methods: Data on psychomotor speed were collected from a representative nation-wide sample of the…
Preference for place of death in Germany.
2011
Dying in the preferred place is considered a key requirement for a "good death." The aims of our study were to explore preferred places of death of deceased people and their bereaved relatives in Rhineland-Palatinate (Germany). We further wanted to assess the congruence between preferred and actual place of death.The cross-sectional study was based on a random sample of 5000 inhabitants of Rhineland-Palatinate (Germany) who died between May 25 and August 24, 2008. Relatives of these deceased persons were interviewed by a written survey.After removing duplicates, 4967 questionnaires were sent out, 3832 delivered, and 1378 completed, yielding a response rate of 36.0%. Regarding the deceased, …