6,347 research outputs found
Factores asociados a la actividad fÃsica y el sedentarismo en los estilos de vida de la juventud española
La comunicación presenta los resultados de un estudio realizado por la Universidad Pablo de Olavide, la Universidad Politécnica de Madrid y la Universidad Europea de Madrid, sobre las tendencias culturales en el abandono de la actividad fÃsica y el deporte entre la juventud española. El estudio, que está realizándose actualmente gracias a una ayuda concedida por el Consejo Superior de Deportes (CSD) (Ref. 007/UPB10/12), analiza cómo la adopción de ese nuevo estilo de vida (sedentario) que está progresivamente afianzándose entre la juventud española puede influir de una manera u otra en la percepción subjetiva de la salud y el bienestar entre este grupo de población
Gamit! Icing on the Cake for Mathematics Gamification
Indexado en ScopusGamification has permeated education as a strategy to improve the teaching-learning process. Research shows that gamified reward systems based on badges, leaderboards, and avatars modifies the learning environment and student attitudes. This research aimed primarily to assess the change in attitude towards mathematics in high school students through a gamified methodology involving a reward system managed through a web platform called Gamit! This platform was developed by professors from two Latin American universities to manage gamification in a way that ensured that the anonymity of the class rankings was maintained. A mixed (QUAN-Qual) and quasi-experimental methodological approach was used for this study; two questionnaires were applied to 454 high school students and a focus group was performed with a group of seven professors. The quantitative analysis was processed with SPSS and consisted of ANOVAS and post hoc tests for more than two samples, while the focus group analysis was performed through inductive analysis. Results show benefits for professors and learners. Students improved their attitudes toward mathematics, reducing anxiety and improving willingness, while professors found a dynamic and optimal way to manage gamification on Gamit!.Revisión por pare
Helmholtz theorem and the v-gauge in the problem of superluminal and instantaneous signals in classical electrodynamics
In this work we substantiate the applying of the Helmholtz vector
decomposition theorem (H-theorem) to vector fields in classical
electrodynamics. Using the H-theorem, within the framework of the two-parameter
Lorentz-like gauge (so called v-gauge), we show that two kinds of magnetic
vector potentials exist: one of them (solenoidal) can act exclusively with the
velocity of light c and the other one (irrotational) with an arbitrary finite
velocity (including a velocity more than c . We show also that the
irrotational component of the electric field has a physical meaning and can
propagate exclusively instantaneously.Comment: This variant has been accepted for publication in Found. Phys.
Letter
El efecto migrante retornante femenino en la aparici?n de emprendimientos innovadores con valor social en el Per?
Esta tesis est? hecha con la intenci?n de conocer la manera en que la migrante retornante femenino contribuye a la generaci?n de emprendimientos innovadores con valor social en un pa?s emergente como el Per?. El estudio se centra en casos de estudio en Per?, el cu?l es un pa?s que no necesariamente ofrece el mejor escenario econ?mico y de inversi?n y, no obstante, ser uno de los pa?ses con mayor tasa de emprendimientos a nivel mundial. Tambi?n, se observ? que estos emprendimientos innovadores, se nutren de su experiencia internacional que los provee de conocimientos y habilidades que aumentan su panorama estrat?gico y capacidad de manejo de una empresa u organizaci?n. Por otro lado, en los casos estudiados en esta tesis el emprendimiento se da por un deseo profundo de mejorar las condiciones de la poblaci?n vulnerable y de retornar a la sociedad los beneficios recibidos
Fructooligosaccharides production by solid-state fermentation with Aspergillus niger PSH
Fructoligosacharides (FOS)
belong to prebiotics group that are non- digestible oligosacharides but fermentable
by the bacteria in the gut microbiota1
. FOS
can be produced by inulin degradation, which
results in products with long fructoligomer
chains2
. Alternatively, FOS can be obtained
by conversion of the sucrose using
fructosyltransferase (FTase) or β-
fructofuranosidase (FFase) enzymes from
bacterial and fungal sources2
. The curent
proces for industrial production of FOS uses
FTase produced by Aspergilus niger, and
reaches an yield value of aprox. 60%3
. The
present study evaluated the FOS production
by solid-state fermentation (SSF) with the
objective of finding a technology able to
produce FOS with higher yield
ESCRT-III is necessary for the integrity of the nuclear envelope in micronuclei but is aberrant at ruptured micronuclear envelopes generating damage
Micronuclei represent the cellular attempt to compartmentalize DNA to maintain genomic integrity threatened by mitotic errors and genotoxic events. Some micronuclei show aberrant nuclear envelopes (NEs) that collapse, generating damaged DNA that can promote complex genome alterations. However, ruptured micronuclei also provide a pool of cytosolic DNA that can stimulate antitumor immunity, revealing the complexity of micronuclear impact on tumor progression. The ESCRT-III (Endosomal Sorting Complex Required for Transport-III) complex ensures NE reseals during late mitosis and is repaired in interphase. Therefore, ESCRT-III activity maybe crucial for maintaining the integrity of other genomic structures enclosed by a NE. ESCRT-III activity at the NE is coordinated by the subunit CHMP7. We show that CHMP7 and ESCRT-III protect against the genomic instability associated with micronuclei formation. Loss of ESCRT-III activity increases the population of micronuclei with ruptured NEs, revealing that its NE repair activity is also necessary to maintain micronuclei integrity. Surprisingly, aberrant accumulation of ESCRT-III are found at the envelope of most acentric collapsed micronuclei, suggesting that ESCRT-III is not recycled efficiently from these structures. Moreover, CHMP7 depletion relieves micronuclei from the aberrant accumulations of ESCRT-III. CHMP7-depleted cells display a reduction in micronuclei containing the DNA damage marker RPA and a sensor of cytosolic DNA. Thus, ESCRT-III activity appears to protect from the consequence of genomic instability in a dichotomous fashion: ESCRT-III membrane repair activity prevents the occurrence of micronuclei with weak envelopes, but the aberrant accumulation of ESCRT-III on a subset of micronuclei appears to exacerbate DNA damage and sustain proinflammatory pathways
North African Influences and Potential Bias in Case-Control Association Studies in the Spanish Population
BACKGROUND: Despite the limited genetic heterogeneity of Spanish populations, substantial evidences support that historical African influences have not affected them uniformly. Accounting for such population differences might be essential to reduce spurious results in association studies of genetic factors with disease. Using ancestry informative markers (AIMs), we aimed to measure the African influences in Spanish populations and to explore whether these might introduce statistical bias in population-based association studies. METHODOLOGY/PRINCIPAL FINDINGS: We genotyped 93 AIMs in Spanish (from the Canary Islands and the Iberian Peninsula) and Northwest Africans, and conducted population and individual-based clustering analyses along with reference data from the HapMap, HGDP-CEPH, and other sources. We found significant differences for the Northwest African influence among Spanish populations from as low as ≈ 5% in Spanish from the Iberian Peninsula to as much as ≈ 17% in Canary Islanders, whereas the sub-Saharan African influence was negligible. Strikingly, the Northwest African ancestry showed a wide inter-individual variation in Canary Islanders ranging from 0% to 96%, reflecting the violent way the Islands were conquered and colonized by the Spanish in the XV century. As a consequence, a comparison of allele frequencies between Spanish samples from the Iberian Peninsula and the Canary Islands evidenced an excess of markers with significant differences. However, the inflation of p-values for the differences was adequately controlled by correcting for genetic ancestry estimates derived from a reduced number of AIMs. CONCLUSIONS/SIGNIFICANCE: Although the African influences estimated might be biased due to marker ascertainment, these results confirm that Northwest African genetic footprints are recognizable nowadays in the Spanish populations, particularly in Canary Islanders, and that the uneven African influences existing in these populations might increase the risk for false positives in association studies. Adjusting for population stratification assessed with a few dozen AIMs would be sufficient to control this effect
ANTIMICROBIAL ACTIVITY OF GYMNOSPERMA GLUTINOSUM (SPRENG.) LESS. (ASTERACEAE) METHANOL EXTRACTS AGAINST HELICOBACTER PYLORI
Background: Prolonged use of antibiotics may lead to the selection of drug-resistant bacteria; as a result, efforts are being made to identify new and effective antimicrobial agents, particularly, from medicinal plants, against bacterial infections. Antimicrobial activity of Gymnosperma glutinosum against Helicobacter pylori has not yet been reported.
Materials and methods: The antibacterial in vitro effect of Gymnosperma glutinosum methanol leaf extracts against Helicobacter pylori (ATCC 43504) was evaluated in liquid medium by the colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) reduction assay and in solid medium by the colony forming units (CFU) method.
Results: Methanol extracts significantly (
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