Este artículo sitúa el foco de interés en los estudiantes de las universidades presenciales y en los modelos de enseñanza a distancia (ED) implementados durante el periodo de confinamiento causado ...por la crisis del COVID-19. Los objetivos son analizar la incidencia del contexto personal y familiar en la equidad digital, identificar el modelo de enseñanza recibido, y conocer su valoración y percepción sobre este modelo. La investigación obedece a un estudio mixto de alcance descriptivo en el que se combinan métodos cualitativos y cuantitativos. En primer lugar, se realizó un cuestionario a estudiantes de la Universidad de Extremadura (UEx) (n= 548) y a posteriori se efectuaron entrevistas online a miembros del equipo de gobierno de la universidad. Los resultados indican que los estudiantes procedentes de familias con un nivel formativo bajo tienen menos oportunidades de uso de tecnologías digitales. Las clases virtuales que han recibido han consistido esencialmente en presentaciones subidas al campus virtual con interacciones asíncronas. La valoración negativa que hacen de la enseñanza a distancia se explica por la inversa relación percibida entre dedicación al estudio y rendimiento académico y por falta de adaptación de los docentes a las circunstancias personales y académicas de los estudiantes. En conclusión, se determina que la universidad debe transitar hacia modelos más colaborativos y centrados en el estudiante.
Background Idiopathic normal pressure hydrocephalus (iNPH) is an important cause of gait disturbance and cognitive impairment in elderly adults. However, the epidemiology of iNPH is relatively ...unknown, largely as a result of the paucity of specifically designed population studies. This systematic review aims to assess the prevalence and incidence of iNPH. Methods A systematic literature review on the epidemiology of iNPH was conducted using MEDLINE/PubMed searching for articles published up to June 2014. Results The inclusion criteria were met by 21 studies. Of the studies, 12 were specifically designed for detecting cases of iNPH; however, only 4 were prospective. In people >65 years old, pooled prevalence obtained from specific population studies was 1.3%, which was almost 50-fold higher than that inferred from door-to-door surveys of dementia or parkinsonism. Prevalence may be higher in assisted-living and extended-care residents, with 11.6% of patients fulfilling the criteria for suspected iNPH and 2.0% of patients showing permanent improvement after cerebrospinal fluid diversion. The only prospective population-based survey that reported iNPH incidence estimated 1.20 cases/1000 inhabitants/year, 15-fold higher than estimates obtained from studies based on hospital catchment areas. The incidence of shunt surgery for iNPH and shunt-responsive iNPH obtained from incident cases of hospital catchment areas appears to be <2 cases/100,000 inhabitants/year and 1 case/100,000 inhabitants/year, respectively. No population-based study reporting the real values for these 2 parameters could be found. Conclusions iNPH appears to be extremely underdiagnosed. Properly designed and adequately powered population-based studies are required to characterize the epidemiology of this disease accurately.
Background: Traditional agricultural systems in Mesoamerica are adaptations of ancient farmers to the complex and varied environments. Tezcalera represents one of them. Questions: How is the ...environmental context under which the tezcalera develop? Which management practices are followed in tezcalera? How do these management practices affect weeds' richness, composition, and abundance? How do these management practices contribute to the resilience of the agricultural system, the tropical dry forests, and to the maintenance of subsistence resources? Studied species: Weeds growing in tezcaleras with different management. Study site and dates: Zumpahuacán, State of México, 2020-2021 Methods: Twenty-four collaborators were interviewed about the environmental, technological, and cultural aspects of tezcalera. We recorded weeds' richness, composition, and abundance in seven plots with different management histories. Results: Tezcaleras originate from the slash-burn process and follow different paths: tlacolol-milsol-shallow plot, potrero, and recently, Agave crop. We recorded 161 morphospecies from 45 botanical families; 95 % were native to tropical dry forests. Twenty-five species are endemic to the Balsas region, and thirty-four are at risk. Richness and abundance varied between tezcaleras, where tlacolol plots exhibited the highest values. Plant composition was similar; 65 % had intangible or tangible values. Conclusions: Tezcalera is a biocultural unit and a resilient agroecosystem. Traditional practices remain and positively impact the richness and composition of native weeds. The uncontrolled use of herbicides and the introduction of Agave crop are displacing traditional crops and modifying traditional practices, risking local agrobiodiversity.
Background Although the incidence of idiopathic normal-pressure hydrocephalus (iNPH) can be 1.20 cases/1000 inhabitants/year in individuals ≥70 years old, in most series, the incidence of ...shunt-responsive iNPH appears to be <1/100,000 inhabitants/year. We report the results of a prospective 10-year longitudinal study of the incidence of iNPH in a northern Spanish population. Methods In a stable population of 590,000 inhabitants served by a single neurosurgical department, we periodically asked all primary care practitioners, neurologists, and geriatricians to refer for iNPH screening any patient with ventricular dilation who was complaining of motor disturbances, cognitive impairment, or sphincter dysfunction. Results From January 2003 to December 2012, 293 patients were referred with suspected normal-pressure hydrocephalus. In 187 patients, iNPH was diagnosed; 89 of these patients were classified as probable iNPH, and 98 were classified as possible iNPH. Cerebrospinal fluid diversion was performed in 152 patients, and 119 showed a good outcome. The incidence of iNPH was significantly greater in male patients and patients >60 years old and increased exponentially with age. After age 60, the standardized age- and sex-adjusted incidence rates for iNPH, shunt surgery for iNPH, and shunt-responsive iNPH were 13.36 cases/100,000 inhabitants/year, 10.85 cases/100,000 inhabitants/year, and 8.55 cases/100,000 inhabitants/year. No differences were detected in the response rate between probable and possible iNPH (80.52% vs. 76.00%; P = 0.497). Conclusions Even with a protocol for patient referral in place, reported iNPH incidence was lower than predicted, reflecting a persistent problem of underdiagnosis in our population.
Los seres humanos llevan toda la vida experimentando modelos de gobernabilidad para garantizar un cierto equilibrio y una mínima satisfacción popular. Los griegos dieron con una fórmula y crearon ...Estados con una cierta representatividad del pueblo y nace lo que ellos llamaron demos Krátos, que significa algo así como gobierno del pueblo. Fue un gran invento para la gestión del pueblo por parte de los griegos, que luego se convierte en un anhelo de toda la humanidad. La democracia se expresa en el debate, en el que se supone que se manifiestan conjeturas diferentes e incluso opuestas. La arbitrariedad es defendida por las facciones opuestas, con el objetivo de delinear la geometría conceptual, sobre la cual converger temporalmente. Sin embargo, la democracia es también un espejismo de libertad (si es que ésta es realmente posible). Las diferentes conceptualizaciones y acepciones que se puedan desarrollar del mismo término pueden pervertir la esencia íntima del concepto. Y es que, de la democracia a la oligarquía hay un paso corto y una delgada línea divisoria. Con una acertada comunicación estratégica, es fácil convertirla una en la otra, y cubrir las acciones y decisiones de un gobierno autoritario con un delicado entramado mediático que difumine la verdad, si es que ésta existe. ¿Democracia para el siglo XXI? Oímos constantemente hablar de recesión, anomalías y déficits democráticos. Por eso es bueno cuestionarse y repensar los modelos democráticos. Y es lo que intentamos desgranar en este ensayo compartido, analizando recorridos históricos y escenarios contemporáneos para aventurarnos a profetizar buscando respuestas a modo de adivinación del futuro. Diferentes puntos de vista, diversas cosmogonías y distintos enfoques para reflexionar sobre un tema siempre candente y tan necesario ahora en cualquier rincón del planeta como hace 25 siglos cuando en el ágora ateniense comenzaron a plantear esta vía de gobernabilidad.
Pseudomonas fluorescentes y Bacillus spp. se encuentran entre las bacterias con mayor potencial para el control biológico de enfermedades en plantas. Los objetivos de esta investigación fueron: i) ...identificar especies de Pseudomonas fluorescentes y Bacillus de la rizósfera de agaves silvestres antagonistas de bacterias pectinolíticas, y ii) detectar la presencia de genes para la biosíntesis de lipopéptidos antimicrobianos (AMPs) en las cepas antagonistas. Se evaluó el índice de eficiencia antagonista (IEA) in vitro de 109 cepas de Pseudomonas fluorescentes y 119 de Bacillus spp. aisladas de la rizósfera de agaves silvestre contra cinco cepas bacterianas pectinolíticas de los géneros Pectobacterium y Dickeya. Por PCR, las bacterias antagonistas se identificaron por secuenciación del gen 16S rRNA y se detectaron los genes AMPs: fenD (fengicina), ituC (iturina), srfAA (surfactina), y bmy (bacilomicina) para Bacillus spp.; prnD (pirrolnitrina) y phlD (2,4 diacetilfloroglucinol) para Pseudomonas fluorescentes con iniciadores específicos. Los resultados del IEA in vitro resultó en la selección de 25 cepas antagonistas contra una o más bacterias pectinolítcas. La comparación de las secuencias del gen 16S rRNA identificaron 11 (44%) cepas en el género Bacillus y 14 (56%) en Pseudomonas con similitud entre el 97 y 100%. Entre las especies de Bacillus y Pseudomonas, la mayoría albergó entre dos a cuatro genes AMPs. Los genes ItuC, srfAA y phlD fueron de mayor frecuencia en todas las cepas antagonistas; en las cepas Bacillus subtilis (9B14) y Pseudomonas fluorescens (G3, D4 y H6) se detectaron todos los genes evaluados.
Excess of visceral adipose tissue (VAT) characteristic of obesity leads to a proinflammatory state disrupting the insulin signaling pathway, triggering insulin resistance (IR) and inflammation, the ...main processes contributing to obesity comorbidities. Ursolic acid (UA), a pentacyclic triterpenoid occurring in a variety of plant foods, exhibits anti-inflammatory properties. The aim of this study was to evaluate UA effects on IR, hyperinsulinemia, and inflammation in experimental diet-induced obesity. Forty male Wistar rats were randomly assigned to eight groups (
= 5). One group was used for time 0. Three groups were labeled as OBE (control): receiving high-fat diet (HFD; fat content 45.24% of energy) during 3, 6, or 9 weeks; three groups UA-PREV: exposed to simultaneous HFD and UA during 3, 6, or 9 weeks to evaluate UA preventive effects; one group UA-REV: receiving HFD for 6 weeks, followed by simultaneous HFD and UA for three additional weeks to analyze UA reversal effects. Measurements were performed after 3, 6, or 9 weeks of treatment. Adiposity was calculated by weighing VAT after sacrifice. Serum markers were quantified through colorimetric and enzyme-linked immunosorbent assay methods. VAT adipokines RNAm expression was evaluated by quantitative reverse transcriptase-polymerase chain reaction. Data were analyzed by Kruskal-Wallis and Mann-Whitney
tests. UA significantly decreased adiposity, IR, hyperinsulinemia, triacylglycerides, and cholesterol levels, and also VAT mRNA expression of MCP-1 (monocyte chemoattractant protein-1), IL (interleukin)-1
and IL-6, concomitantly increasing adiponectin levels. UA metabolic effects demonstrated in this study support its potential therapeutic utility to improve IR, hyperinsulinemia, and inflammation observed in obesity and diabetes.
El método de la viga conjugada, para cálculo de deformaciones y momentos de empotramiento en flexión, ha sido abandonado por varios autores de los libros de Mecánica de Materiales más populares en ...América; no obstante partiendo de la ecuación general de la elástica para flexión se puede fundamentar su uso. Planteado de forma adecuada, la viga conjugada resulta un método rápido y sencillo, una vez comprendido los conceptos fundamentales de fuerza cortante y momento Flexionante.
Bone allografts, which are used as bone regeneration material, must satisfy two functions: a biologic function and a mechanical function. The biologic task is satisfied by enrichment of the osseous ...reconstructive material with mesenchymal cells, radio-sterilized and lyophilized, which helps to a more efficient formation of new bone. Regarding the mechanical function, the allografts must be as rigid and strong as intact bone for immediate load-bearing capability. Consequently, a good mechanical characterization is needed to guarantee the structural integrity of the allografts in the host tissue. Thus, in this work results are presented from compression testing of cancellous and cortical/cancellous allograft tissue chips, as well as results on flexure and pure shear testing of cortical allograft strips. The test specimens were fabricated according to standard procedures. For the cancellous graft chips, different elastic moduli were obtained a long the three perpendicular directions, 32.2, 98.2, and 162.4 MPa, showing orthotropic behavior. For the cortical/cancellous chips, compression loads were only applied along the longitudinal and transversal directions of the cortical phase; the corresponding elastic moduli displayed were 518.6 and 384.8 MPa. On the other hand, for the cortical graft strips, the flexure elastic modulus obtained was 38.9 GPa; reported flexure elastic modulus in the literature for fresh human bone are between 1.525 and 31.5 GPa. Finally the shear strength exhibited by the cortical graft was 43.6 MPa.
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