327 research outputs found
Desarrollo de habilidades comunicativas del inglés usando la plataforma Macmillan Education Everywhere en estudiantes de un centro de idiomas, 2022
La investigación tuvo como objetivo principal el analizar el desarrollo de las
habilidades comunicativas del inglés mediante el uso de la plataforma Macmillan
Education Everywhere (MEE) en un Centro de Idiomas en Moquegua durante el
periodo académico 2022, por lo que, dentro del enfoque cualitativo se desarrolló un
estudio de casos cuyos resultados y evidencia fueron apoyados en la triangulación
intramétodo considerando la literatura, los antecedentes, la percepción de los
estudiantes, la situación académica final de los estudiantes así como las fichas de
observación del desarrollo de las sesiones de aprendizaje en el nivel básico
intensivo en el que llevó a cabo la investigación. Los resultados obtenidos muestran
que el desarrollo de las habilidades comunicativas se da de forma óptima, siendo
la habilidad comunicativa de mayor desarrollo el “escuchar “, mientras que las
habilidades “leer” y “hablar” se desarrollaron en menor medida y finalmente la
habilidad “escribir” fue la de menor desarrollo, pero no debajo del nivel óptimo; estos
resultados muestran que las cuatro habilidades se desarrollan plenamente a través
de la plataforma MEE. La inclusión de recursos digitales adicionales propias de la
plataforma representó una mejora adicional en el desarrollo de las habilidades en
mención respecto a la percepción del uso de la plataforma individualmente, así
como del desarrollo de los recursos propuestos por el método Straightforward en
su segunda edición a través de la plataforma MEE
Open questions in site characterization and turbulence parameter measurements
With the development of increasingly larger and more complex telescopes and instrumentation, site testing and characterization efforts also increase in both magnitude and complexity. This happens because the investment into larger observatories is higher and because new technologies, such as adaptive optics, require knowledge about parameters that did not matter previously, such as the vertical distribution of turbulence. We present examples of remaining questions which, to date, are not generally addressed by "standard" site characterization efforts, either because they are technically not (yet) feasible or because they are impractical. We center our observations around the experience gained during the Thirty Meter Telescope (TMT) site testing effort with an emphasis on turbulence measurements, but our findings are applicable in general to other current and future projects as well
Comparación de las barreras al comercio exterior para la exportación de paltas entre Perú y México a Estados Unidos en el período 2015-2020
El presente trabajo de investigación tiene como objetivo evaluar las barreras al comercio exterior que enfrentan las organizaciones exportadoras de palta de Perú y México al realizar intercambios comerciales hacia Estados Unidos. Se investigan las dimensiones de acuerdos comerciales, estructura logística y oferta exportable, abordando indicadores como el precio pagado al productor, volumen de producción por toneladas y costo documental y fronterizo para exportar. El objetivo es determinar si existen diferencias significativas entre las barreras al comercio exterior para la exportación de paltas de Perú y México hacia Estados Unidos, tomando como referencia el periodo 2015-2020. El estudio muestra como marco teórico investigaciones basadas en teorías que son fundamentadas por artículos científicos, la cuales respaldan los temas relacionados con las variables, la metodología empleada forma parte de un enfoque cuantitativo de diseño no experimental, recolectando datos de las principales aduanas y evaluándolos mediante herramientas estadísticas descriptivas e inferenciales.The present investigation research aims to evaluate the barriers to foreign trade faced by avocado exporting organizations from Peru and Mexico when conducting commercial exchanges with the United States. The dimensions of trade agreements, logistics structure, and exportable supply are investigated, addressing indicators such as producer price, production volume in tons, and documentary and border costs for exportation. The objective is to determine if there are significant differences in the barriers to foreign trade for avocado exports from Peru and Mexico to the United States, using the period 2015-2020 as reference. The study draws on theoretical frameworks supported by scientific articles that address the variables, and the methodology employed adopts a quantitative approach with a non-experimental design, collecting data from the main customs offices and analyzing them using descriptive and inferential statistical tools
Kalibracija modela montažnih drvenih zidnih okvira izrađenih od drva Hieronyma alchorneoides i Gmelina arborea uz pomoć čavala i vijaka
The object of this research is to develop a model for the calibration of prefabricated timber wall frames (PTWFs) with dimension of 244 by 244 cm (width by height) respectively made of Gmelina arborea Roxb. and Hieronyma alchorneoides Allemão wood and two types of fastener (nails and screws). The PTWFs were submitted to a lateral load test and the vertical and horizontal displacement, maximum load (Pm), strength, stiffness values and mode of failure were determined. Results showed a greater failure percentage in the joint between the central stud and the top and bottom plates for both species and both fastener types used. PTWFs made of H. alchorneoides timber using screws showed greatervalues than PTWFs made of G. arborea for load at the proportionality limit and maximum load. Finally, computational model showed that the highest calibration percentage was achieved in the vertical orientation in PTWFs made using nails in both species. Meanwhile, PTWFs using screws showed calibration percentages of 58.0 and 43.5 %. The highest calibration percentage of 89.9 % was recorded in G. arborea PTWFs joined with nails, whereas the lowest calibration percentage of 69.4 % was recorded in H. alchorneoides PTWFs joined with screws.Cilj istraživanja bio je razviti model za kalibraciju montažnih drvenih zidnih okvira (PTWF) dimenzija 244 × 244 cm (širina × visina) izrađenih od drva Gmelina arborea Roxb. i Hieronyma alchorneoides Allemão te uz upotrebu dviju vrsta vezivnih elemenata (čavala i vijaka). PTWF-ovi su podvrgnuti testu bočnog opterećenja te su utvrđeni vertikalni i horizontalni pomak, maksimalno opterećenje (Pm), čvrstoća, krutost i način oštećenja. Rezultati su pokazali najveći postotak oštećenja u spoju između središnjeg nosača i gornjega odnosno donjeg okvira za PTWF-ove od obiju vrsta drva i spojenih obama tipovima vezivnih elemenata. PTWF-ovi izrađeni od drva H. alchorneoides i spojeni vijcima imali su veće vrijednosti opterećenja na granici proporcionalnosti i maksimalnog opterećenja od PTWF-ova proizvedenih od drva G. arborea. Konačno, računalni je model pokazao da je najveći postotak kalibracije postignut u vertikalnom smjeru u PTWF-ova izrađenih od obiju vrsta drva i spojenih čavlima. Istodobno, PTWF-ovi spojeni vijcima pokazali su postotke kalibracije 58,0 i 43,5 %. Najveći postotak kalibracije bio je 89,9 %, a zabilježen je u PTWF-u od drva G. arborea i spojenom čavlima, dok je najniži postotak kalibracije ustanovljen u PTWF-u od drva H. alchorneoides spojenom vijcima, a iznosio je 69,4 %
Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle
The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission
to image in the visible (0.4-0.9 micron) planetary systems of nearby stars
simultaneously in 16 spectral bands (resolution R~20). For the ~10 most
favorable stars, it will have the sensitivity to discover 2 R_E rocky planets
within habitable zones and characterize their surfaces or atmospheres through
spectrophotometry. Many more massive planets and debris discs will be imaged
and characterized for the first time. With a 1.2m visible telescope, the
proposed mission achieves its power by exploiting the most efficient and robust
coronagraphic and wavefront control techniques. The Phase-Induced Amplitude
Apodization (PIAA) coronagraph used by TOPS allows planet detection at 2
lambda/d with nearly 100% throughput and preserves the telescope angular
resolution. An efficient focal plane wavefront sensing scheme accurately
measures wavefront aberrations which are fed back to the telescope active
primary mirror. Fine wavefront control is also performed independently in each
of 4 spectral channels, resulting in a system that is robust to wavefront
chromaticity.Comment: 12 pages, SPIE conference proceeding, May 2006, Orlando, Florid
Virtualidad y educación en tiempos de COVID-19
The health pandemic caused by Covid-19 has generated an unprecedented crisis in all sectors. In education, this pandemic has led to the mass closure of face-to-face activities in educational institutions in more than 190 countries around the world to prevent the spread of the disease and reduce its impact. The challenge for education systems over the past two years has been to maintain the vitality of education and promote the development of meaningful learning. To this end, it has relied on two key allies: teachers and the management of virtuality, in more precise terms, teachers through virtuality.La pandemia sanitaria ocasionada por el Covid-19 ha generado una crisis sin precedentes en todos los sectores. En el ámbito educativo, esta pandemia ha dado lugar al cierre masivo de las actividades presenciales de instituciones educativas en más de 190 países en el mundo con el firme propósito de evitar la propagación de esta enfermedad y reducir su impacto. El reto de los diversos sistemas educativos en los últimos dos años ha sido tratar de mantener la vitalidad de la educación y promover el desarrollo de aprendizajes significativos. Para ello, ha contado con dos aliados clave: los docentes y el manejo de la virtualidad, en términos más precisos, los docentes a través de la virtualidad
La Gobernanza de las Políticas Públicas en Tiempos de Pandemia
Governance is understood as a style of organizing society based on the conjunction of government and trust. In this sense, the covid-19 pandemic has highlighted the considerable contrast between the strengths and weaknesses of governance and leadership worldwide. Governance in times of pandemic has become vitally important for countries, as it has been observed that those with a better governance index have been better able to respond to the health emergency than those countries that have not been well governed. The context of the health pandemic has brought to light a different world, where governmental actions have been decisive in dealing with the emergency, mainly because it is not possible to adopt only reactive measures or measures adapted from a traditional recession, as this would be insufficient. It is imperative that governments consider implementing bold transformations in the face of this new world that has become different from the one we have known.Entendiendo que la gobernanza es un estilo de organización de una sociedad basada en la conjunción entre gobierno y confianza. En tal sentido, la pandemia de covid-19 ha evidenciado el considerable contraste entre las fortalezas y debilidades de la gobernanza y el liderazgo en todo el mundo. La gobernanza en tiempos de pandemia ha cobrado vital relevancia para los países, puesto que se ha observado que aquellos con un mejor índice de gobernanza han tenido una mejor capacidad de respuesta frente a la emergencia sanitaria que aquellos países que no vienen siendo bien gobernados. El contexto de la pandemia sanitaria ha llevado a transparentar un mundo diferente, en donde las acciones gubernamentales han sido determinantes para afrontar la emergencia, debido fundamentalmente a que no se puede adoptar solamente medidas reactivas o adaptadas de una recesión tradicional puesto que se ser así, resultarían insuficientes. Resulta imperativo que los gobiernos consideren la implementación de transformaciones audaces frente a este nuevo mundo que se ha tornado distinto al que conocimos
VEGF and TGF-β are required for the maintenance of the choroid plexus and ependyma
Although the role of vascular endothelial growth factor (VEGF) in developmental and pathological angiogenesis is well established, its function in the adult is less clear. Similarly, although transforming growth factor (TGF) β is involved in angiogenesis, presumably by mediating capillary (endothelial cell [EC]) stability, its involvement in quiescent vasculature is virtually uninvestigated. Given the neurological findings in patients treated with VEGF-neutralizing therapy (bevacizumab) and in patients with severe preeclampsia, which is mediated by soluble VEGF receptor 1/soluble Fms-like tyrosine kinase receptor 1 and soluble endoglin, a TGF-β signaling inhibitor, we investigated the roles of VEGF and TGF-β in choroid plexus (CP) integrity and function in adult mice. Receptors for VEGF and TGF-β were detected in adult CP, as well as on ependymal cells. Inhibition of VEGF led to decreased CP vascular perfusion, which was associated with fibrin deposition. Simultaneous blockade of VEGF and TGF-β resulted in the loss of fenestrae on CP vasculature and thickening of the otherwise attenuated capillary endothelium, as well as the disappearance of ependymal cell microvilli and the development of periventricular edema. These results provide compelling evidence that both VEGF and TGF-β are involved in the regulation of EC stability, ependymal cell function, and periventricular permeability
Changes in Ricco's Area with background luminance in the S-Cone Pathway
Purpose: The area of complete spatial summation (Ricco’s area) for achromatic stimuli has previously been shown to decrease with increased background luminance. A popular hypothesis is that such a phenomenon reflects increased center-surround antagonism within the receptive field of the retinal ganglion cell. We wished to investigate if similar changes in Ricco’s area occur with blue background luminance for the S-cone pathway, guided by the knowledge that the retinal ganglion cells with S-cone input do not display S-cone–mediated center-surround antagonism (S+/S-).
Methods: Spatial summation functions were measured for four young healthy observers under S-cone pathway isolation by presenting blue test stimuli on a background consisting of intense fixed yellow (600 cd/m2) component in combination with a variable blue component (background range, 1.78 to 2.82 log S-Td). Ricco’s area was estimated by two-phase regression analysis.
Results: All subjects demonstrated a notable decrease in Ricco’s area with increasing blue background luminance. On average, Ricco’s area decreased in size by 0.39 log units per log unit increase in blue background luminance.
Conclusions: The change in Ricco’s area with the blue background component is not what one would initially expect given the known organization of S-cone–driven cells at the retinal level. Spatial reorganization by the suppressive surround of the receptive fields at a cortical level and a reduction in the contribution from S-cones with the lowest weights in the retinal receptive field periphery are among the possible mechanisms of the summation changes observed. These findings have implications for the design of clinical tests of the S-cone pathway
- …