169 research outputs found
Fission yeast SWI/SNF and RSC complexes show compositional and functional differences from budding yeast.
SWI/SNF chromatin-remodeling complexes have crucial roles in transcription and other chromatin-related processes. The analysis of the two members of this class in Saccharomyces cerevisiae, SWI/SNF and RSC, has heavily contributed to our understanding of these complexes. To understand the in vivo functions of SWI/SNF and RSC in an evolutionarily distant organism, we have characterized these complexes in Schizosaccharomyces pombe. Although core components are conserved between the two yeasts, the compositions of S. pombe SWI/SNF and RSC differ from their S. cerevisiae counterparts and in some ways are more similar to metazoan complexes. Furthermore, several of the conserved proteins, including actin-like proteins, are markedly different between the two yeasts with respect to their requirement for viability. Finally, phenotypic and microarray analyses identified widespread requirements for SWI/SNF and RSC on transcription including strong evidence that SWI/SNF directly represses iron-transport genes
Query Expansion of Zero-Hit Subject Searches: Using a Thesaurus in Conjunction with NLP Techniques
The focus of our study is zero-hit queries in keyword subject searches and the effort of increasing recall in these cases by reformulating and, then, expanding the initial queries using an external source of knowledge, namely a thesaurus. To this end, the objectives of this study are twofold. First, we perform the mapping of query terms to the thesaurus terms. Second, we use the matched terms to expand the user’s initial query by taking advantage of the thesaurus relations and implementing natural language processing (NLP) techniques. We report on the overall procedure and elaborate on key points and considerations of each step of the process
Forward Flux Sampling for rare event simulations
Rare events are ubiquitous in many different fields, yet they are notoriously
difficult to simulate because few, if any, events are observed in a conventiona
l simulation run. Over the past several decades, specialised simulation methods
have been developed to overcome this problem. We review one recently-developed
class of such methods, known as Forward Flux Sampling. Forward Flux Sampling
uses a series of interfaces between the initial and final states to calculate
rate constants and generate transition paths, for rare events in equilibrium or
nonequilibrium systems with stochastic dynamics. This review draws together a
number of recent advances, summarizes several applications of the method and
highlights challenges that remain to be overcome.Comment: minor typos in the manuscript. J.Phys.:Condensed Matter (accepted for
publication
Global warming will affect the maximum potential abundance of boreal plant species
Forecasting the impact of future global warming on biodiversity requires understanding how temperature limits the distribution of species. Here we rely on Liebig's Law of Minimum to estimate the effect of temperature on the maximum potential abundance that a species can attain at a certain location. We develop 95%‐quantile regressions to model the influence of effective temperature sum on the maximum potential abundance of 25 common understory plant species of Finland, along 868 nationwide plots sampled in 1985. Fifteen of these species showed a significant response to temperature sum that was consistent in temperature‐only models and in all‐predictors models, which also included cumulative precipitation, soil texture, soil fertility, tree species and stand maturity as predictors. For species with significant and consistent responses to temperature, we forecasted potential shifts in abundance for the period 2041–2070 under the IPCC A1B emission scenario using temperature‐only models. We predict major potential changes in abundance and average northward distribution shifts of 6–8 km yr−1. Our results emphasize inter‐specific differences in the impact of global warming on the understory layer of boreal forests. Species in all functional groups from dwarf shrubs, herbs and grasses to bryophytes and lichens showed significant responses to temperature, while temperature did not limit the abundance of 10 species. We discuss the interest of modelling the ‘maximum potential abundance’ to deal with the uncertainty in the predictions of realized abundances associated to the effect of environmental factors not accounted for and to dispersal limitations of species, among others. We believe this concept has a promising and unexplored potential to forecast the impact of specific drivers of global change under future scenarios.202
A novel mistranslating tRNA model in Drosophila melanogaster has diverse, sexually dimorphic effects
Transfer RNAs (tRNAs) are the adaptor molecules required for reading the genetic code and producing proteins. Transfer RNA variants can lead to genome-wide mistranslation, the misincorporation of amino acids not specified by the standard genetic code into nascent proteins. While genome sequencing has identified putative mistranslating transfer RNA variants in human populations, little is known regarding how mistranslation affects multicellular organisms. Here, we create a multicellular model of mistranslation by integrating a serine transfer RNA variant that mistranslates serine for proline (tRNAUGG,G26ASer) into the Drosophila melanogaster genome. We confirm mistranslation via mass spectrometry and find that tRNAUGG,G26ASer misincorporates serine for proline at a frequency of ∼0.6% per codon. tRNAUGG,G26ASer extends development time and decreases the number of flies that reach adulthood. While both sexes of adult flies containing tRNAUGG,G26ASer present with morphological deformities and poor climbing performance, these effects are more pronounced in female flies and the impact on climbing performance is exacerbated by age. This model will enable studies into the synergistic effects of mistranslating transfer RNA variants and disease-causing alleles
The environmental impact of pharmaceuticals in Italy: Integrating healthcare and eco-toxicological data to assess and potentially mitigate their diffusion to water supplies
Pharmaceuticals can reach the environment at all stages of their lifecycle and accumulate in the ecosystem, potentially reaching toxic levels for animals and plants. In recent years, efforts have been made to map and control this hazard. Assessing country-specific environmental risks could drive regulatory actions towards eco-friendlier drug utilization and disposal practices. By starting from a list of 25 environmentally hazardous pharmaceuticals developed by Region Stockholm, we integrated eco-toxicological and 2019-2021 Italian drug utilization data to estimate the environmental impact of pharmaceuticals in Italy. We calculated the risk as the ratio between the predicted environmental concentration (PEC) and the predicted no-effect concentration (PNEC). We found a high risk for levonorgestrel, ciprofloxacin, amoxicillin, azithromycin, venlafaxine, sertraline and diclofenac and a moderate risk for ethinyloestradiol, oestradiol and clarithromycin. This analysis can be periodically performed to identify the pharmaceuticals with the highest risk for the environment and ascertain if containment measures should be implemented
Skills development in teacher Practicum: PBL and Multidimensional coaching
Esta investigación pretende contribuir al conocimiento de la influencia del Practicum en el
desarrollo de competencias por parte de los maestros y maestras en su formación inicial. Se
expone una revisión de estudios en esta materia y la evolución de la metodología docente
empleada en Practicum en la Facultad de Ciencias de la Educación de la Universidad de Córdoba.
Se presentan las bases del modelo actual de Practicum, focalizado en el Aprendizaje Basado en
Problemas mediante Coaching Multidimensional (modelo ABP-CM) especialmente diseñado para
potenciar el desarrollo de competencias. Se realizó un estudio pretest/postest con la finalidad de
estudiar el impacto del Practicum bajo el modelo ABP-CM sobre la propia percepción del alumnado
del desarrollo de sus competencias. Entre pretest y postest solo medió la experiencia formativa
de Prácticum I del grado de Educación Primaria. En el pretest participaron 145 estudiantes y en el
postest 196. Los datos se recogieron mediante un cuestionario auto-informe compuesto por ítems
sobre el grado auto-percibido de desarrollo de competencias transversales, específicas y
prácticas. Los resultados muestran un avance significativo en el desarrollo auto-percibido de la
mitad de las competencias. Se vieron mejoradas: un tercio de las competencias transversales
(especialmente las personales y sistémicas); más de la mitad de las competencias específicas; y
tres cuartas partes de las competencias concretas de Practicum. La naturaleza de muchas de las
competencias más beneficiadas es concordante con la naturaleza de las estrategias docentes
empleadas, lo que nos lleva a inferir que el modelo ABP-CM desarrollado en Practicum es un buen
catalizador para el desarrollo y cristalización de competencias.This research aims to contribute to the knowledge of the Practicum influence in
the teachers’ development of competences in the initial training. This work presents a review of
studies in this area and the development of the methodology used in the Practicum at the Faculty
of Educational Sciences of the University of Cordoba. Bases of the Practicum current model are
presented, focused on Problem-Based Learning by Multidimensional Coaching (PBL-MC model),
especially designed to enhance the development of competences. A pretest/postest study was
made in order to study the impact of the Practicum under thePLB-CM model on students’ own
perception of their competences development. The training experience of the Practicum I in
Primary Education Degree mediated between the pretest and the postest. 145 Students took part
in the pretest and 196 in the postest. Data were collected using a self-report questionnaire
consisting of items about the self-perceived level of generic, specific and practical competences
development. The results show a significant advance in the self-perceived development in 50% of
the competences. One third of the generic competences (especially personal and systemic) were
improved; it means more than half of the specific competences, and three quarters of the specific
competences of the Practicum. The nature of many of the most benefitted competences is
accordant with the nature of the teaching strategies used, which leads us to deduce that the
model developed in PBL-CM Practicum is a good catalyst for competences development and
crystallization.Grupo FORCE (HUM-386). Departamento de Didáctica y Organización Escolar de la Universidad de Granad
Acceptability of a Hypothetical Zika Vaccine among Women from Colombia and Spain Exposed to ZIKV: A Qualitative Study.
Zika virus (ZIKV) can cause pregnancy loss and congenital
Zika syndrome, among other poor health outcomes. The ZIKV
epidemic in 2015-2017 disproportionately affected pregnant women
in poor-resource settings. We aimed to understand perceptions
and attitudes towards a hypothetical ZIKV vaccine, women's
willingness to be vaccinated, and potential barriers and
facilitators for vaccine acceptance in 1) migrant women living
in Spain who travelled to their countries of origin and were
diagnosed with ZIKV infection during pregnancy, and their
healthcare providers, and 2) women living in Colombia who
delivered a child with microcephaly. An exploratory qualitative
study based on phenomenology and grounded theory was conducted.
Data were collected through in-depth, paired and semi-structured
interviews. Overall, women from both sites were willing to
receive a hypothetical ZIKV vaccine. However, some expressed
concerns of being vaccinated during pregnancy, yet they would
accept it if the vaccine was recommended by a healthcare
professional they trust. Main fears towards vaccination were
related to vaccine safety and potential adverse effects on
child's health. Women reported feeling hesitant to participate
in a ZIKV vaccine trial. These results may contribute to guiding
the effective delivery of future ZIKV vaccines among populations
most at risk and particularly vulnerable
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Genetic inhibition of hepatic acetyl-CoA carboxylase activity increases liver fat and alters global protein acetylationa
Lipid deposition in the liver is associated with metabolic disorders including fatty liver disease, type II diabetes, and hepatocellular cancer. The enzymes acetyl-CoA carboxylase 1 (ACC1) and ACC2 are powerful regulators of hepatic fat storage; therefore, their inhibition is expected to prevent the development of fatty liver. In this study we generated liver-specific ACC1 and ACC2 double knockout (LDKO) mice to determine how the loss of ACC activity affects liver fat metabolism and whole-body physiology. Characterization of LDKO mice revealed unexpected phenotypes of increased hepatic triglyceride and decreased fat oxidation. We also observed that chronic ACC inhibition led to hyper-acetylation of proteins in the extra-mitochondrial space. In sum, these data reveal the existence of a compensatory pathway that protects hepatic fat stores when ACC enzymes are inhibited. Furthermore, we identified an important role for ACC enzymes in the regulation of protein acetylation in the extra-mitochondrial space
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