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Background Wine yeasts can produce undesirable sulfur compounds during alcoholic fermentation, such as SO 2 and H 2 S, in variable amounts depending mostly on the yeast strain but also on the conditions. However, although sulfur metabolism has been widely studied, some of the genetic determinants of differences in sulfite and/or sulfide production between wine yeast strains remain to be identified. In this study, we used an integrated approach to decipher the genetic determinants of variation in the production of undesirable sulfur compounds. Results We examined the kinetics of SO 2 production by two parental strains, one high and one low sulfite producer. These strains displayed similar production profiles but only the high-sulfite producer strain continued to produce SO 2 in the stationary phase. Transcriptomic analysis revealed that the low-sulfite producer strain overexpressed genes of the sulfur assimilation pathway, which is the mark of a lower flux through the pathway consistent with a lower intracellular concentration in cysteine. A QTL mapping strategy then enabled us to identify MET2 and SKP2 as the genes responsible for these phenotypic differences between strains and we identified new variants of these genes in the low-sulfite producer strain. MET2 influences the availability of a metabolic intermediate, O-acetylhomoserine, whereas SKP2 affects the activity of a key enzyme of the sulfur assimilation branch of the pathway, the APS kinase, encoded by MET14 . Furthermore, these genes also affected the production of propanol and acetaldehyde. These pleiotropic effects are probably linked to the influence of these genes on interconnected pathways and to the chemical reactivity of sulfite with other metabolites. Conclusions This study provides new insight into the regulation of sulfur metabolism in wine yeasts and identifies variants of MET2 and SKP2 genes, that control the activity of both branches of the sulfur amino acid synthesis pathway and modulate sulfite/sulfide production and other related phenotypes. These results provide novel targets for the improvement of wine yeast strains.

Yeast cell death can occur during wine alcoholic fermentation. It is generally considered toresult from ethanol stress that impacts membrane integrity. This cell death mainly occurswhen grape musts processing reduces lipid availability, resulting in weaker membrane resistanceto ethanol. However the mechanisms underlying cell death in these conditions remainunclear. We examined cell death occurrence considering yeast cells ability to elicit an appropriateresponse to a given nutrient limitation and thus survive starvation. We show here thata set of micronutrients (oleic acid, ergosterol, pantothenic acid and nicotinic acid) in low,growth-restricting concentrations trigger cell death in alcoholic fermentation when nitrogenlevel is high. We provide evidence that nitrogen signaling is involved in cell death and thateither SCH9 deletion or Tor inhibition prevent cell death in several types of micronutrient limitation.Under such limitations, yeast cells fail to acquire any stress resistance and areunable to store glycogen. Unexpectedly, transcriptome analyses did not reveal any majorchanges in stress genes expression, suggesting that post-transcriptional events critical forstress response were not triggered by micronutrient starvation. Our data point to the factthat yeast cell death results from yeast inability to trigger an appropriate stress responseunder some conditions of nutrient limitations most likely not encountered by yeast in thewild. Our conclusions provide a novel frame for considering both cell death and the managementof nutrients during alcoholic fermentation.

BackgroundDue to the rising demands for a Canadian workforce with science, technology, engineering, and math (STEM)-related education, there is a need to increase youth engagement in STEM education and programming. Research, however, has shown that youth residing in low-income communities are disproportionately affected by psychosocial barriers, which often inhibit meaningful engagement in STEM programming. Visions of Science Network for Learning (VoSNL) was designed and implemented to address these existing barriers. VoSNL is a charitable organization in Southern Ontario, Canada, that provides weekly community-based STEM programming to low-income and marginalized youth during out-of-school time. VoSNL programming is delivered directly within the community and is free-of-charge for all youth in order to minimize barriers of physical and financial accessibility. The purpose of this report was to provide a detailed description of a core program within VoSNL—Community Science Clubs—and summarize the findings of a process evaluation, specifically the successes and challenges of implementing a community-based, out-of-school STEM program.ResultsProgram successes are outlined along with the challenges that have been identified through program implementation. Successes include (a) delivering the program within a community context, (b) opportunities for consistent engagement, and (c) establishing positive youth-staff relationships. Challenges include (a) navigating community-based issues, (b) conducting outreach and promotion, and (c) accommodating a wide age range of youth. Further, lessons learned from an evaluation of program implementation are also discussed.ConclusionsThis report provides one of the first program descriptions and process evaluations of a community-based, youth-focused STEM program within a Canadian context. The findings in this report have helped to improve the delivery and evaluation of the VoSNL program and may act as a catalyst for program expansion to reach more youth in marginalized communities. Further, the findings can also provide a strong framework for programmers interested in implementing STEM youth programming in a community context, assist in the replication of similar models in other locations, and enhance STEM learning amongst youth.

Abstract Saccharomyces cerevisiae requirement for reduced sulfur to synthesize methionine and cysteine during alcoholic fermentation, is mainly fulfilled through the sulfur assimilation pathway. Saccharomyces cerevisiae reduces sulfate into sulfur dioxide (SO2) and sulfide (H2S), whose overproduction is a major issue in winemaking, due to its negative impact on wine aroma. The amount of H2S produced is highly strain-specific and also depends on SO2 concentration, often added to grape must. Applying a bulk segregant analysis to a 96-strain-progeny derived from two strains with different abilities to produce H2S, and comparing allelic frequencies along the genome of pools of segregants producing contrasting H2S quantities, we identified two causative regions involved in H2S production in the presence of SO2. A functional genetic analysis allowed the identification of variants in four genes able to impact H2S formation, viz; ZWF1, ZRT2, SNR2, and YLR125W, and involved in functions and pathways not associated with sulfur metabolism until now. These data point out that, in wine fermentation conditions, redox status, and zinc homeostasis are linked to H2S formation while providing new insights into the regulation of H2S production, and a new vision of the interplay between the sulfur assimilation pathway and cell metabolism.

Disturbance events occur outside the normal disturbance regime of a system and can cause changes in behavior of some organisms. The 2010 cold event is an example of a disturbance event that influenced the behavior of Common Snook (Centropomus undecimalis). Common snook are euryhaline sportfish native to Florida, Texas, and the Caribbean. Florida is the northern most part of their distribution, based on the 15° C winter isotherm. They move between offshore areas during spawning season and freshwater coastal rivers during non-spawning season. With the use of previously collected acoustic telemetry and biological data this project identifies the impact on population dynamics and movement near the time of the event. The goal is to understand fine scale movements and physiological conditions under normal and abnormal conditions to further inform management of the species.

La presente investigación se ejecutó con la finalidad de evidenciar el desarrollo de la inclusión educativa de niños con parálisis cerebral, considerando que un entorno incluyente debe potenciar las capacidades del estudiante para acceder a la información. En este contexto, se propuso un mapa de ruta de prácticas de inclusión que contemplan discapacidad intelectual y física. Como primera medida, se llevó a cabo un estudio de tipo descriptivo en el que se tuvieron en cuenta artículos científicos a niveles mundial, regional y nacional. Asimismo, tomando las bases de datos Web of Science y Scopus, se realizó un análisis bibliométrico a través de VOSviewer para identificar los países con mayor aporte científico en el campo de la discapacidad múltiple, las universidades que presentan dichos trabajos y los investigadores más relevantes en relación con la cantidad de citas. Los resultados se evaluaron a través del método analítico-sintético, contrastándolos con los objetivos planteados. Se halló que, a escala mundial, los países con mayor impacto científico en el ámbito mencionado son Estados Unidos, Australia e Inglaterra. Se concluye que el análisis bibliométrico respalda unos resultados funcionales ysustentables del trabajo, promulgando el impacto científico en la educación.

Yeast cell death can occur during wine alcoholic fermentation and lead to sluggish or stuck fermentations. The mechanisms underlying cell death during yeast starvation in alcoholic fermentations remain unclear. In this work we addressed yeast cell death using conceptual framework from ageing studies showing that yeast resistance to starvation can be influenced by the nature of the nutrient limiting cell growth. We examined cell death occurrence considering yeast cells ability to elicit an appropriate response to a set of nutrient limitations. We show that several micronutrients limitations (oleic acid, ergosterol, pantothenic acid and nicotinic acid) trigger cell death in a nitrogen-dependent manner. We provide evidence that the nitrogen Tor/Sch9 signaling pathway is involved in triggering cell death. In such conditions, yeast cells fail to acquire stress resistance given a restriction at a post-transcriptional level. We have examined the ability of different nitrogen sources to trigger cell death and show that they impact differentially on cell death and that NH+ 4 had a strong death inducing capacity. Finally, the QTLs approaches allowed the mapping of a set of loci controlling cell death under oleic acid and pantothenic acid starvation consistent with a multigenic control.

Yeast cell death can occur during wine alcoholic fermentation and lead to sluggish or stuck fermentations. The mechanisms underlying cell death during yeast starvation in alcoholic fermentations remain unclear. In this work we addressed yeast cell death using conceptual framework from ageing studies showing that yeast resistance to starvation can be influenced by the nature of the nutrient limiting cell growth. We examined cell death occurrence considering yeast cells ability to elicit an appropriate response to a set of nutrient limitations. We show that several micronutrients limitations (oleic acid, ergosterol, pantothenic acid and nicotinic acid) trigger cell death in a nitrogen-dependent manner. We provide evidence that the nitrogen Tor/Sch9 signaling pathway is involved in triggering cell death. In such conditions, yeast cells fail to acquire stress resistance given a restriction at a post-transcriptional level. We have examined the ability of different nitrogen sources to trigger cell death and show that they impact differentially on cell death and that NH 4  + had a strong death inducing capacity. Finally, the QTLs approaches allowed the mapping of a set of loci controlling cell death under oleic acid and pantothenic acid starvation consistent with a multigenic control.

LEGO robotics is a very popular tool for introducing engineering concepts to elementary school classrooms through project-based learning and open-ended design challenges. It is useful for this purpose because LEGO bricks are reusable materials, they allow for designs to be quickly iterated upon, and it is easy for students to design very different solutions to the engineering problem with which they are presented. This thesis proposes a wireless LEGO robotics kit programmed from an Apple iPad, targeted for a 2nd-3 rd grade classroom. The product is designed to fill a gap between two currently existing LEGO products: the LEGO MINDSTORMS NXT and the WeDo. This device is intended to be more flexible for a larger variety of activities than the WeDo, and to expand the age range of the target market to students as old as 3rd grade, before they are ready to begin using the NXT. This is done in three main ways. First, the new device is wireless, which allows the robot hub to be used in activities and applications where it is impractical to be within tethered reach of the computer (e.g. moving across the floor, hanging from the ceiling, etc.). Next, the robot hub can turn on the motors with a simple button press, without being programmed at all. This allows students to focus on physical building before moving to computer programming, a common sequence in classrooms, while still being able to add motion to and test their designs. Finally, students can program their robot builds with either a computer or an iPad. The Apple iPad is a popular tablet that is very intuitive for younger children to use, and some classrooms utilize it as their main computer resource. Allowing this device to interact with and even control a robot in the real world opens up endless possibilities for future projects involving the iPad interacting with the physical world around it. The goal of this project is to develop a new robotics platform and programming interface, and perform initial testing with this platform with 2nd-3rd grade children. This report describes the first two iterations of this device, and suggests a direction for further development of this project.

Saccharomyces cerevisiae is a major actor in winemaking that converts sugars from the grape must into ethanol and CO2 with outstanding efficiency. Primary metabolites produced during fermentation have a great importance in wine. While ethanol content contributes to the overall profile, other metabolites like glycerol, succinate, etc., also have significant impacts, even when present in lower concentrations. S. cerevisiae is known for its great genetic diversity that is related to its natural or technological environment. However, its range of metabolic diversity which can be exploited to enhance wine quality depends on the pathway considered. Our experiment assessed the diversity of primary metabolites production in a set of 51 S. cerevisiae strains from various genetic backgrounds. Results pointed out great yield differences depending on the metabolite considered, with ethanol having the least variation. A negative correlation between ethanol and glycerol was observed, confirming glycerol synthesis as a suitable lever to reduce ethanol yield. Genetic groups were linked to specific metabolic yields such as α-ketoglutarate or acetate. This research highlights the potential of using natural yeast diversity in winemaking and provides detailed data set on metabolite production of well known (ethanol, glycerol, acetate) or little-known (lactate) primary metabolites production.