Influencia de la tecnología multimedia en el aprendizaje de las estudiantes de la especialidad de industria alimentaria de la Institución Educativa Nº 51, UGEL 02, San Martín de Porres, Lima, 2011

El objetivo de esta investigación es determinar cuál es el nivel de influencia de la tecnología multimedia en el aprendizaje de las estudiantes de la especialidad de industria Alimentaria de la I.E. Nº 51 UGEL 02, San Martín de Porres, Lima, 2011. La población del presente trabajo de investigación está conformada por 300 estudiantes de la especialidad de Industria alimentaria del área de educación para el trabajo de la IE Nº51, la muestra es de 100 estudiante. Los datos estadísticos que sostienen esta investigación vienen de los resultados obtenidos por la aplicación de los instrumentos a las estudiantes y validados por el informe de opinión de expertos de la Universidad César Vallejo, entre ellas tenemos como instrumentos cuestionario de aceptabilidad y un cuestionario de conocimiento. Los resultados de la contrastación de la hipótesis demuestran que hay relación causal entre las variables investigadas, por lo que concluimos que la tecnología multimedia influye de medio hacia arriba en el aprendizaje de las estudiantes porque les permite adquirir y procesar gran cantidad de información, reflexionar y comprender mejor el tema de estudio y por ende lograr mejores niveles de aprendizaje de las estudiantes en cada sesión de clase

Moisture origins of the Amazon carbon source region

The southeastern Amazon has recently been shown to be a net carbon source, which is partly caused by drying conditions. Drying depends on a number of factors, one of which is the land cover at the locations where the moisture has originated as evaporation. Here we assess for the first time the origins of the moisture that precipitates in the Amazon carbon source region, using output from a Lagrangian atmospheric moisture tracking model. We relate vegetation productivity in the Amazon carbon source region to precipitation patterns and derive land-cover data at the moisture origins of these areas, allowing us to estimate how the carbon cycle and hydrological cycle are linked in this critical part of the Amazon. We find that, annually, 13% of the precipitation in the Amazon carbon source region has evaporated from that same area, which is half of its land-derived moisture. We further find a moisture-recycling-mediated increase in gross primary productivity of roughly 41 Mg carbon km−2 yr−1 within the Amazon carbon source region if it is fully forested compared to any other land cover. Our results indicate that the parts of the Amazon forest that are already a net carbon source, still help sustain their own biomass production. Although the most degraded parts of the Amazon depend mostly on oceanic input of moisture, further degradation of this region would amplify carbon losses to the atmosphere

Plan estratégico de gestión del talento en el estudio de abogados Bafur

El presente trabajo tiene como objetivo principal desarrollar un Plan Estratégico de Gestión del Talento 2019-2023 para los abogados del Estudio BAFUR, basado en la mejora de cuatro principales áreas de Gestión de Talento como: Perfil por Competencias, Proceso de Selección de Personal, Evaluación del Desempeño, y Compensación y Beneficios. El Estudio BAFUR, es una empresa del sector privado orientada a brindar servicios profesionales legales, con 50 años de experiencia; a lo largo de su trayectoria, ha gestionado su crecimiento en el mercado de forma empírica, sin contar con procesos y procedimientos que permitan una gestión eficiente del talento humano de los abogados

Impact of changing oxygenation policies on retinopathy of prematurity in a neonatal unit in Argentina.

AIMS: To assess the impact of different oxygenation policies on the rate and severity of retinopathy of prematurity (ROP). METHODS: Between January 2003 and December 2006, infants of 1500 g birthweight (BW) or less and/or 32 weeks gestational age (GA) or less, and larger, more mature infants with risk factors for ROP were examined through three different time periods: period 1: high target oxygen saturation levels (88-96%) and treatment at threshold ROP; period 2: low target oxygen saturation levels (83-93%) and treatment at threshold ROP; period 3: low target oxygen saturation and treatment at type 1 ROP. RESULTS: Type 1 ROP was detected more frequently in babies of 32 weeks GA or less (50/365, 13.7%) than in more mature babies (15/1167, 1.3%; p<0.001). The rate of type 1 ROP in period 1 was 6.9%; period 2, 3.6% and period 3, 1.8%. Rates of stage 3 ROP declined over time in both BW/GA groups (from 9.0% to 4.1% to 2.0%) as did rates of plus disease (from 7.5% to 3.6% to 1.8%). Mean BW and GA declined from period 1 to period 3, and death rates remained unchanged. 74.4% of babies received all the examinations required; 48.1% of treatments were undertaken after discharge from the neonatal unit. CONCLUSIONS: Lower target oxygen saturation was associated with a lower rate of severe ROP without increasing mortality, and changed the characteristics of affected babies. Screening criteria need to remain wide enough to identify all babies at risk of ROP needing treatment

Amazonia as a carbon source linked to deforestation and climate change

Amazonia hosts the Earth's largest tropical forests and has been shown to be an important carbon sink over recent decades1-3. This carbon sink seems to be in decline, however, as a result of factors such as deforestation and climate change1-3. Here we investigate Amazonia's carbon budget and the main drivers responsible for its change into a carbon source. We performed 590 aircraft vertical profiling measurements of lower-tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in Amazonia from 2010 to 20184. We find that total carbon emissions are greater in eastern Amazonia than in the western part, mostly as a result of spatial differences in carbon-monoxide-derived fire emissions. Southeastern Amazonia, in particular, acts as a net carbon source (total carbon flux minus fire emissions) to the atmosphere. Over the past 40 years, eastern Amazonia has been subjected to more deforestation, warming and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends5-9. We explore the effect of climate change and deforestation trends on carbon emissions at our study sites, and find that the intensification of the dry season and an increase in deforestation seem to promote ecosystem stress, increase in fire occurrence, and higher carbon emissions in the eastern Amazon. This is in line with recent studies that indicate an increase in tree mortality and a reduction in photosynthesis as a result of climatic changes across Amazonia1,10.</p

Amazonia as a carbon source linked to deforestation and climate change

Amazonia hosts the Earth’s largest tropical forests and has been shown to be an important carbon sink over recent decades1,2,3. This carbon sink seems to be in decline, however, as a result of factors such as deforestation and climate change1,2,3. Here we investigate Amazonia’s carbon budget and the main drivers responsible for its change into a carbon source. We performed 590 aircraft vertical profiling measurements of lower-tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in Amazonia from 2010 to 20184. We find that total carbon emissions are greater in eastern Amazonia than in the western part, mostly as a result of spatial differences in carbon-monoxide-derived fire emissions. Southeastern Amazonia, in particular, acts as a net carbon source (total carbon flux minus fire emissions) to the atmosphere. Over the past 40 years, eastern Amazonia has been subjected to more deforestation, warming and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends5,6,7,8,9. We explore the effect of climate change and deforestation trends on carbon emissions at our study sites, and find that the intensification of the dry season and an increase in deforestation seem to promote ecosystem stress, increase in fire occurrence, and higher carbon emissions in the eastern Amazon. This is in line with recent studies that indicate an increase in tree mortality and a reduction in photosynthesis as a result of climatic changes across Amazonia1,10

CO2 emissions in the Amazon: are bottom-up estimates from land use and cover datasets consistent with top-down estimates based on atmospheric measurements?

Amazon forests are the largest forests in the tropics and play a fundamental role for regional and global ecosystem service provision. However, they are under threat primarily from deforestation. Amazonia's carbon balance trend reflects the condition of its forests. There are different approaches to estimate large-scale carbon balances, including top-down (e.g., CO2 atmospheric measurements combined with atmospheric transport information) and bottom-up (e.g., land use and cover change (LUCC) data based on remote sensing methods). It is important to understand their similarities and differences. Here we provide bottom-up LUCC estimates and determine to what extent they are consistent with recent top-down flux estimates during 2010 to 2018 for the Brazilian Amazon. We combine LUCC datasets resulting in annual LUCC maps from 2010 to 2018 with emissions and removals for each LUCC, and compare the resulting CO2 estimates with top-down estimates based on atmospheric measurements. We take into account forest carbon stock maps for estimating loss processes, and carbon uptake of regenerating and mature forests. In the bottom-up approach total CO2 emissions (2010 to 2018), deforestation and degradation are the largest contributing processes accounting for 58% (4.3 PgCO2) and 37% (2.7 PgCO2) respectively. Looking at the total carbon uptake, primary forests play a dominant role accounting for 79% (−5.9 PgCO2) and secondary forest growth for 17% (−1.2 PgCO2). Overall, according to our bottom-up estimates the Brazilian Amazon is a carbon sink until 2014 and a source from 2015 to 2018. In contrast according to the top-down approach the Brazilian Amazon is a source during the entire period. Both approaches estimate largest emissions in 2016. During the period where flux signs are the same (2015–2018) top-down estimates are approximately 3 times larger in 2015–2016 than bottom-up estimates while in 2017–2018 there is closer agreement. There is some agreement between the approaches–notably that the Brazilian Amazon has been a source during 2015–2018 however there are also disagreements. Generally, emissions estimated by the bottom-up approach tend to be lower. Understanding the differences will help improve both approaches and our understanding of the Amazon carbon cycle under human pressure and climate change

Optimización de región de contraste mediante la prueba de hipótesis, utilizando p-valores en el lema de Neyman Pearson

TesisDe una población se puede obtener varias muestras aleatorias, dependiendo si se relaciona con reemplazo o sin reemplazo y por definición un estimador es función de la muestra aleatoria. Para el estudio de distribución de confianza es suficiente una sola muestra aleatoria y, así podemos demostrar el lema de Neyman-Pearson en una primera parte en su forma clásica luego generalizar este lema usando el p-valor, para lo cual en el presente trabajo de tesis obtendremos una muestra aleatoria mediante la simulación utilizando el lenguaje R, para luego ejecutar una prueba de hipótesis y obtener al mismo tiempo intervalos de confianza

Moisture sources of the Amazon carbon source

Among the greatest threats to the global climate is the possibility that the Amazon rainforest, Earth’s largest carbon stock, becomes a net carbon source. To estimate the Amazon’s carbon budget, Gatti et al. (2021) performed 590 atmospheric vertical profiling measurements from four sites using aircraft over the course of eight years. They found that intact forests of the southeastern Amazon already act as a carbon source. This is likely related to decreased precipitation levels, stressing the importance of maintaining or enhancing precipitation levels in that region. The level and variability of precipitation partly depends on the land cover at the location where the moisture has evaporated. Forests in the Amazon enhance evapotranspiration, which significantly contributes to regional precipitation levels. This spatial connection between evapotranspiration and precipitation implies a causal link between forest cover at a certain location and the carbon budget at remote locations. To determine these evapotranspiration-precipitation connections, we use a high-resolution Lagrangian atmospheric moisture tracking model forced with ERA5 reanalysis data. We determine the seasonally changing spatial distributions of the moisture sources of different parts of the Amazon that have different carbon dynamics. We obtain land characteristics of these moisture-source areas to explore the potential of forest restoration for maintaining or regaining the carbon sink in the Amazon. We find that, on average, about one-third of the precipitation in the area identified as a carbon source originates as evaporation from land, the majority of which in this region itself. We find seasonality in the amount of moisture that is recycled within this region, peaking in the fourth quarter. The results indicate that deforestation in the southeastern Amazon may accelerate the carbon emissions from remaining intact parts of the Amazon. Further, they show where forest restoration may be prioritized to prevent these emissions

Moisture sources of the Amazon carbon source

Among the greatest threats to the global climate is the possibility that the Amazon rainforest, Earth’s largest carbon stock, becomes a net carbon source. To estimate the Amazon’s carbon budget, Gatti et al. (2021) performed 590 atmospheric vertical profiling measurements from four sites using aircraft over the course of eight years. They found that intact forests of the southeastern Amazon already act as a carbon source. This is likely related to decreased precipitation levels, stressing the importance of maintaining or enhancing precipitation levels in that region. The level and variability of precipitation partly depends on the land cover at the location where the moisture has evaporated. Forests in the Amazon enhance evapotranspiration, which significantly contributes to regional precipitation levels. This spatial connection between evapotranspiration and precipitation implies a causal link between forest cover at a certain location and the carbon budget at remote locations. To determine these evapotranspiration-precipitation connections, we use a high-resolution Lagrangian atmospheric moisture tracking model forced with ERA5 reanalysis data. We determine the seasonally changing spatial distributions of the moisture sources of different parts of the Amazon that have different carbon dynamics. We obtain land characteristics of these moisture-source areas to explore the potential of forest restoration for maintaining or regaining the carbon sink in the Amazon. We find that, on average, about one-third of the precipitation in the area identified as a carbon source originates as evaporation from land, the majority of which in this region itself. We find seasonality in the amount of moisture that is recycled within this region, peaking in the fourth quarter. The results indicate that deforestation in the southeastern Amazon may accelerate the carbon emissions from remaining intact parts of the Amazon. Further, they show where forest restoration may be prioritized to prevent these emissions