1,945 research outputs found
The expression in saccharomyces cerevisiae of a glucose/xylose symporter from Candida intermedia is affected by the presence of a glucose/xylose facilitator
Microbiology, 154Two glucose/xylose transporter genes from Candida intermedia were recently cloned and
characterized: GXF1, which encodes a glucose/xylose facilitator; and GXS1, which encodes a glucose/xylose proton symporter. Here we report the functional expression of these transporters in Saccharomyces cerevisiae. While Gxf1p seems to be fully functional in S. cerevisiae, the symporter Gxs1p exhibits very low glucose/xylose transport activity, which could not be ascribed to insufficient production of the protein or incorrect subcellular localization. In addition, coexpression
of glucose/xylose facilitators with Gxs1p strongly reduced GXS1 mRNA levels, and
consequently symport activity, in glucose-grown, but not in ethanol-grown, cells. The observed decrease in GXS1 transcript levels seems to be related to an enhanced glucose influx mediated by glucose facilitator protein(s), and not to a specific interaction between Gxs1p and other
transporters. We found GXS1 mRNA levels to be severely reduced as a result of glucose addition, and we show that this effect takes place at the level of GXS1 mRNA stability. Our results suggest that a decrease in mRNAs encoding high-affinity/active sugar transport systems may be a widespread and conserved mechanism in yeasts, limiting expression of these proteins whenever their activity is dispensable
From Cambridge Keynesian to Institutional Economist: The Unnoticed Contributions of Robert Neild
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Robert Neild (born 1924) has made a major contribution to economics and to peace studies. This paper provides a brief sketch of Neild’s life and work. While noting his research in economic policy and peace studies, this essay devotes more attention to his largely-unnoticed contributions to institutional and evolutionary economics since 1984. These are important in their own right, but they are especially notable because Cambridge heterodox economists have been devoted mainly to other approaches, including Marxism and post-Keynesianism. Neild’s distinctive contribution is partly explained by his closeness to both Nicholas Kaldor and Gunnar Myrdal. Myrdal made explicit his adherence to the original American institutionalism: Neild extended that link to Cambridge.Peer reviewedFinal Published versio
Research priorities in light of current trends in microsurgical training: revalidation, simulation, cross-training, and standardisation.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/
licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly citedPlastic surgery training worldwide has seen a thorough restructuring over the past decade, with the introduction of formal training curricula and work-based assessment tools. Part of this process has been the introduction of revalidation and a greater use of simulation in training delivery. Simulation is an increasingly important tool for educators because it provides a way to reduce risks to both trainees and patients, whilst facilitating improved technical proficiency. Current microsurgery training interventions are often predicated on theories of skill acquisition and development that follow a 'practice makes perfect' model. Given the changing landscape of surgical training and advances in educational theories related to skill development, research is needed to assess the potential benefits of alternative models, particularly cross-training, a model now widely used in non-medical areas with significant benefits. Furthermore, with the proliferation of microsurgery training interventions and therefore diversity in length, cost, content and models used, appropriate standardisation will be an important factor to ensure that courses deliver consistent and effective training that achieves appropriate levels of competency. Key research requirements should be gathered and used in directing further research in these areas to achieve on-going improvement of microsurgery training
Effect of Discontinuation of Fluoride Intake from Water and Toothpaste on Urinary Excretion in Young Children
As there is no homeostatic mechanism for maintaining circulating fluoride (F) in the human body, the concentration may decrease and increase again when intake is interrupted and re-started. The present study prospectively evaluated this process in children exposed to F intake from water and toothpaste, using F in urine as a biomarker. Eleven children from Ibiá, Brazil (with sub-optimally fluoridated water supply) aged two to four years who regularly used fluoridated toothpaste (1,100 ppm F) took part in the study. Twenty-four-hour urine was collected at baseline (Day 0, F exposure from water and toothpaste) as well as after the interruption of fluoride intake from water and dentifrice (Days 1 to 28) (F interruption) and after fluoride intake from these sources had been re-established (Days 29 to 34) (F re-exposure). Urinary volume was measured, fluoride concentration was determined and the amount of fluoride excreted was calculated and expressed in mg F/day. Urinary fluoride excretion (UFE) during the periods of fluoride exposure, interruption and re-exposure was analyzed using the Wilcoxon test. Mean UFE was 0.25 mg F/day (SD: 0.15) at baseline, dropped to a mean of 0.14 mg F/day during F interruption (SD: 0.07; range: 0.11 to 0.17 mg F/day) and rose to 0.21 (SD: 0.09) and 0.19 (SD: 0.08) following F re-exposure. The difference between baseline UFE and the period of F interruption was statistically significant (p < 0.05), while the difference between baseline and the period of F re-exposure was non-significant (p > 0.05). The findings suggest that circulating F in the body of young children rapidly decreases in the first 24 hours and again increases very fast after discontinuation and re-exposure of F from water and toothpaste
HISTÓRICO E REESTRUTURAÇÃO DAS LINHAS DE PESQUISA DO PROGRAMA DE PÓS-GRADUAÇÃO EM SAÚDE E ENVELHECIMENTO
Esta revisão narrativa apresenta estudos desenvolvidos no curso de mestrado acadêmico do Programa de Pós-graduação em Saúde e Envelhecimento, da Faculdade de Medicina de Marília (Famema), o qual foi aprovado pela CAPES em 2011, com início em 2012. Atualmente, possui duas linhas de pesquisa: (1) Educação e cuidado à saúde no ciclo da vida, (2) Aspectos biológicos e clínicos do binômio saúde-doença no processo de envelhecimento. Integra a Rede dos Programas de Pós-Graduação Interdisciplinares em Envelhecimento (REPRINTE) desde a sua implementação. Importante ressaltar que o Programa de Pós-graduação em Saúde e Envelhecimento não está voltado exclusivamente à formação acadêmico-científica em Geriatria ou Gerontologia, mas também ao “cuidado à saúde e ao enfrentamento de doenças ao longo do processo do envelhecimento", ou seja, do nascimento até a morte. Nos primeiros oito anos de funcionamento do Programa (2012 a 2020), três linhas de pesquisa estavam vigentes, tendo sido configuradas desde o envio da Apresentação de Propostas de Cursos Novos (APCN) à CAPES. Com o transcorrer do curso e as experiências adquiridas, ficou evidente a necessidade de uma profunda reestruturação das linhas e dos projetos de pesquisa cadastrados no programa. Assim, esta narrativa descreve o histórico e o processo de reestruturação das linhas de pesquisa do programa e a revisão dos projetos a elas vinculados
Sugar utilization patterns and respiro-fermentative metabolism in the baker’s yeast Torulaspora delbrueckii
The highly osmo- and cryotolerant yeast species Torulaspora delbrueckii is an important case study among the non-Saccharomyces yeast species. The strain T delbrueckii PYCC 532 1, isolated from traditional corn and rye bread dough in northern Portugal, is considered particularly interesting for the baking industry. This paper reports the sugar utilization patterns of this strain, using media with glucose, maltose and sucrose, alone or in mixtures. Kinetics of growth, biomass and ethanol yields, fermentation and respiration rates, hydrolase activities and sugar uptake rates were used to infer the potential applied relevance of this yeast in comparison to a conventional baker's strain of Saccharomyces cerevisiae. The results showed that both maltase and maltose transport in T delbrueckii were subject to glucose repression and maltose induction, whereas invertase was subject to glucose control but not dependent on sucrose induction. A comparative analysis of specific sugar consumption rates and transport capacities suggests that the transport step limits both glucose and maltose metabolism. Specific rates of CO2 production and O-2 consumption showed a significantly higher contribution of respiration to the overall metabolism in T delbrueckii than in S. cerevisiae. This was reflected in the biomass yields from batch cultures and could represent an asset for the large-scale production of the former species. This work contributes to a better understanding of the physiology of a non-conventional yeast species, with a view to the full exploitation of T delbrueckii by the baking industry.This work was partially funded by Agência de Inovação (AdI) program
POCI2010/2.3, project ‘PARFERM’. C. A.-A. and A. P. were supported
by PhD fellowships from PRAXIS XXI – BD/21543/99 and BD/13282/
2003, respectively (Fundação para a Ciência e para a Tecnologia,
Portugal).info:eu-repo/semantics/publishedVersio
Getting a Head Start: Diet, Sub-Adult Growth, and Associative Learning in a Seed-Eating Passerine
Developmental stress, and individual variation in response to it, can have important fitness consequences. Here we investigated the consequences of variable dietary protein on the duration of growth and associative learning abilities of zebra finches, Taeniopygia guttata, which are obligate graminivores. The high-protein conditions that zebra finches would experience in nature when half-ripe seed is available were mimicked by the use of egg protein to supplement mature seed, which is low in protein content. Growth rates and relative body proportions of males reared either on a low-protein diet (mature seed only) or a high-protein diet (seed plus egg) were determined from body size traits (mass, head width, and tarsus) measured at three developmental stages. Birds reared on the high-protein diet were larger in all size traits at all ages, but growth rates of size traits showed no treatment effects. Relative head size of birds reared on the two diets differed from age day 95 onward, with high-diet birds having larger heads in proportion to both tarsus length and body mass. High-diet birds mastered an associative learning task in fewer bouts than those reared on the low-protein diet. In both diet treatments, amount of sub-adult head growth varied directly, and sub-adult mass change varied inversely, with performance on the learning task. Results indicate that small differences in head growth during the sub-adult period can be associated with substantial differences in adult cognitive performance. Contrary to a previous report, we found no evidence for growth compensation among birds on the low-protein diet. These results have implications for the study of vertebrate cognition, developmental stress, and growth compensation
Pathogen-Specific Epitopes as Epidemiological Tools for Defining the Magnitude of Mycobacterium leprae Transmission in Areas Endemic for Leprosy
During recent years, comparative genomic analysis has allowed the identification of Mycobacterium leprae-specific genes with potential application for the diagnosis of leprosy. In a previous study, 58 synthetic peptides derived from these sequences were tested for their ability to induce production of IFN-γ in PBMC from endemic controls (EC) with unknown exposure to M. leprae, household contacts of leprosy patients and patients, indicating the potential of these synthetic peptides for the diagnosis of sub- or preclinical forms of leprosy. In the present study, the patterns of IFN-γ release of the individuals exposed or non-exposed to M. leprae were compared using an Artificial Neural Network algorithm, and the most promising M. leprae peptides for the identification of exposed people were selected. This subset of M. leprae-specific peptides allowed the differentiation of groups of individuals from sites hyperendemic for leprosy versus those from areas with lower level detection rates. A progressive reduction in the IFN-γ levels in response to the peptides was seen when contacts of multibacillary (MB) patients were compared to other less exposed groups, suggesting a down modulation of IFN-γ production with an increase in bacillary load or exposure to M. leprae. The data generated indicate that an IFN-γ assay based on these peptides applied individually or as a pool can be used as a new tool for predicting the magnitude of M. leprae transmission in a given population
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