173 research outputs found
A Transitional Year Level to Higher Education: Challenges, Experiences and Self-regulatory Strategies during the Final Year of the University Preparatory Level
Final Year level of the University Preparatory cycle (FYUP) –in Spanish 2º Bachillerato– is one of the most challenging academic courses. It is extremely demanding academically in itself and by the end of it students must also pass the university entry exam. Yet research has not investigated how students experience this year. We thus explored, using in-depth interviews with 75 students from two public high schools, their attitudes toward this academic year. Our results showed that (a) the participants struggled greatly during FYUP, experiencing high levels of academic stress (that affects their general well-being, mostly because of the high academic demands); (b) students were looking forward to their university experience but were concerned about failing or not finding their place; and (c) they reported a narrow range of learning, motivational, and emotional strategies. This study shows that students face significant learning and academic challenges during FYUP. A clear educational implication is that interventions should be implemented in earlier years to help the students be better prepared
Contrast of a Quality Control Model for Sustainability in a Mexican Organization in Central Mexico
Often, the total quality has been instrumented before being weighted. The strategies even precede a diagnosis in Mexican organizations, but in an opposite sense, the present work set out to establish the reliability and validity of an instrument to measure the perception of total quality based on three indicators related to management. , production and transfer of knowledge. A nonperimental study was carried out with a non-probabilistic selection of 124 administrative staff and employees from an organization in central Mexico. From a structural model ⌠X2 = 123,24 (23df) p = 0,010; GFI = 0,990; CFI =,991; IFI = 0,993; RMSEA = 0,007⌡, it was found that management affects production (0,38) and this about the total perceived quality (0,35), although there are lines of research concerning empathy, commitment, entrepreneurship, satisfaction and happiness in relation to the implementation of continuous improvements to the quality of processes and products
MaNGIA: 10,000 mock galaxies for stellar population analysis
Modern astronomical observations give unprecedented access to the physical
properties of nearby galaxies, including spatially resolved stellar
populations. However, observations can only give a present-day view of the
Universe, whereas cosmological simulations give access to the past record of
the processes that galaxies have experienced in their evolution. To connect the
events that happened in the past with galactic properties as seen today,
simulations must be taken to a common ground before being compared to
observations. We emulate data from the MaNGA survey, which is the largest
integral field spectroscopic galaxy survey to date with its 10,000 nearby
galaxies of all types. For this, we use the cosmological simulations TNG50 to
generate MaNGIA (Mapping Nearby Galaxies with IllustrisTNG Astrophysics), a
mock MaNGA sample of similar size that emulates observations of galaxies for
stellar population analysis. We choose TNG galaxies to match the MaNGA sample
selection to limit the impact of selection effects. We produce MaNGA-like
datacubes from all simulated galaxies, and process these with the pyPipe3D
analysis code. This allows us to extract spatially resolved stellar maps. This
first paper presents the approach to generate the mock sample and provides an
initial exploration of its properties. We show that the stellar populations and
kinematics of the simulated MaNGIA galaxies are overall in good agreement with
observations. Specific discrepancies, especially in the age and metallicity
gradients in low- to intermediate-mass regimes and in massive galaxies'
kinematics, require further investigation. We compare our results to other
attempts to mock similar observations, all of smaller data sets. Our final
dataset will be released with the publication, consisting of >10,000
post-processed data-cubes analysed with pyPipe3D, along with the codes
developed to create it.Comment: Submitted to A&A, 21 pages, 17 figures, 1 tabl
Inorganic arsenic causes apoptosis cell death and immunotoxicity on European sea bass (Dicentrarchus labrax)
Inorganic arsenic (As) is one of the most toxic pollutants in the water. We have studied their effects on the marine teleost European sea bass (Dicentrarchus labrax) at 2 and 10 days of 5 μMofAs2O3 (sub-lethal doses) waterborne exposure. Arsenic accumulates in liver and gill tissues. The expression profile of five genes (bax, blc2, casp3, casp8 and casp9) involved in apoptosis cell death confirmed apoptotic effects in liver, slight changes in gill and no effects in skin according with the histopathology findings. Total IgM level and peroxidase activities were increased at 2 and 10 days, respectively. The bactericidal activity was decreased at 2 days after As exposure. A general decrease of cellular immune activities with significant differences in the case of respiratory burst activity was observed after 2 and 10 days of exposure. This work describes for the first time the effects of As exposure on European sea bass.Versión del editor2,35
Bisphenol A exposure in Mexico City and risk of prematurity: a pilot nested case control study
Abstract Background Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. Methods A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry. Results BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05). Conclusions This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.http://deepblue.lib.umich.edu/bitstream/2027.42/78251/1/1476-069X-9-62.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78251/2/1476-069X-9-62.pdfPeer Reviewe
Gut-Brain Axis: Role of Microbiota in Parkinson’s Disease and Multiple Sclerosis
It has recently been discovered that the digestive tract is lined with about 100 million nerve cells; the digestive tract has been baptized, metaphorically speaking, as “the second brain,” which contains a multitude of neurotransmitters, viruses, and bacteria that help regulate our emotional state. This second brain, known as the enteric nervous system, is a unique anatomical unit that extends from the esophagus to the anus. Like the nervous system, it produces a whole series of psychoactive substances, such as serotonin, dopamine, and opioids for pain, and synthesizes benzodiazepines. In it, we find the microbiota: a set of microorganisms (viruses and bacteria). Together with the brain, the microbiota directly influences mood, character, or sleep. Knowledge about the possible relationship of the microbiota with frequent neurological diseases is still just beginning. Recently, possible changes in the microbiota have been linked to the onset of Parkinson’s disease (PD). Also, today, we know that there are differences between the microbiota of healthy people and people with multiple sclerosis and that these differences have also been related to the disease and its evolution
Lower IgG somatic hypermutation rates during acute dengue virus infection is compatible with a germinal center-independent B cell response
Reads, clonal groups, and lineages numbers per individual and condition. The table shows the number of raw and used sequences as well as the number of clonotypes and lineages per individual. (XLS 30 kb
Propuestas para una reforma laboral democrática
Este trabajo, presenta trece propuestas complementarias sobre los temas centrales de la reforma laboral: la contracción individual y colectiva, con si variable de "subcontratación"; la transparencia con la proposición concreta de creación del registro nacional de contratos y sindicatos; los salarios y la jornada laboral, temas clave en el proyecto de país de la izquierda democrátic
Perspectivas de la empresa y la economía mexicana frente a la reestructuración productiva
1 archivo PDF (404 páginas)Este texto se presenta una reflexión de investigadores de la UAM, así como de otras Instituciones de Educación Superior respecto al marco en el que se han desenvuelto las empresas mexicanas en los últimos años, así como del desarrollo en algunos de sus sistemas organizacionales. PALABRAS CLAVE: Mexico Economic policy 1970-1994
Nickel and cobalt ilmenites-based catalysts for upgrading pyrolytic oil during pyrolysis ofwaste tires
Pyrolysis as a waste treatment method has gained relevance because it can generate higher value-added products in addition to reducing the environment’s secondary pollution. In this study, the catalytic pyrolysis of waste tires was evaluated using NiTiO3 and CoTiO3 ilmenites as catalysts and precursors of metal catalysts with the aim to produce an oil enriched in high-value hydrocarbons, such as benzene, toluene, a xylenes mixture, and products less-reported, such as p-cymene and p-cymenene. The experiments were performed in an analytical pyrolyzer coupled to GC/MS. The effect of the nature of the catalysts on the product distribution was compared with the uncatalyzed reaction. The main products of uncatalyzed pyrolysis were D, L-limonene (~60%), and isoprene (~25%) due to the depolymerization of natural rubber. Meanwhile, Ni-ilmenites-based catalysts favored the formation of target compounds to expense D, L-limonene. Moreover, the presence of metal in reduced-ilmenite sharply enhanced the selectivity by ~50% concerning oxidized ilmenite and above 80% compared to the uncatalyzed reaction for p-cymene and p-cymenene. By contrast, the Co-ilmenites-based catalysts showed a marginal effect on secondary reactions. Finally, the feasibility of forming the aromatic terpenes, p-cymene, and p-cymenene from limonene in the non-catalytic pyrolysis was evaluated.Centro de Investigación y Desarrollo en Ciencias Aplicada
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