60 research outputs found

    Un análisis de la representación gráfica de la función logarítmica: historia y conocimiento didáctico de contenido

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    Este trabajo presenta un análisis de información de documentos de la literatura en Educación Matemática, consistente en un aporte, analizado a la luz de la teoría del Conocimiento Didáctico de Contenido, de los conocimientos con respecto a la representación gráfica de la función logarítmica vista desde su desarrollo histórico, que deberían integrar el conocimiento del profesor en formación. Con el objetivo que sea un compendio de conocimientos y elementos que permita que el profesor no solo apropiarse del objeto matemático, sino también proponer actividades para el aula fundamentadas en la caracterización que se hace de las construcciones de la representación gráfica de la función logarítmica, contenida en los documentos, a través los mecanismos de construcción y las construcciones mentales, propuestas en la teoría APOS

    Reporte Estabilidad Financiera - Primer Semestre de 2020

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    In the face of the multiple shocks currently experienced by the domestic economy (resulting from the drop in oil prices and the appearance of a global pandemic), the Colombian financial system is in a position of sound solvency and adequate liquidity. At the same time, credit quality has been recovering and the exposure of credit institutions to firms with currency mismatches has declined relative to previous episodes of sudden drops in oil prices. These trends are reflected in the recent fading of red and blue tonalities in the performance and credit risk segments of the risk heatmaps in Graphs A and B.1 Naturally, the sudden, unanticipated change in macroeconomic conditions has caused the appearance of vulnerabilities for short-term financial stability. These vulnerabilities require close and continuous monitoring on the part of economic authorities. The main vulnerability is the response of credit and credit risk to a potential, temporarily extreme macroeconomic situation in the context of: (i) recently increased exposure of some banks to household sector, and (ii) reductions in net interest income that have led to a decline in the profitability of the banking business in the recent past. Furthermore, as a consequence of greater uncertainty and risk aversion, occasional problems may arise in the distribution of liquidity between agents and financial markets. With regards to local markets, spikes have been registered in the volatility of public and private fixed income securities in recent weeks that are consistent with the behavior of the international markets and have had a significant impact on the liquidity of those instruments (red portions in the most recent past of some market risk items on the map in Graph A). In order to adopt a forward-looking approach to those vulnerabilities, this Report presents a stress test that evaluates the resilience of credit institutions in the event of a hypothetical scenario thatseeks to simulate an extreme version of current macroeconomic conditions. The scenario assumes a hypothetical negative growth that is temporarily strong but recovers going into the middle of the coming year and has extreme effects on credit quality. The results suggest that credit institutions have the ability to withstand a significant deterioration in economic conditions in the short term. Even though there could be a strong impact on credit, liquidity, and profitability under the scenario being considered, aggregate capital ratios would probably remain at above their regulatory limits over the horizon of a year. In this context, the recent measures taken by both Banco de la República and the Office of the Financial Superintendent of Colombia that are intended to help preserve the financial stability of the Colombian economy become highly relevant. In compliance with its constitutional objectives and in coordination with the financial system’s security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions that are necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth functioning of the payment system. Juan José Echavarría Governo

    Financial Stability Report - Second Semester of 2020

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    The Colombian financial system has not suffered major structural disruptions during these months of deep economic contraction and has continued to carry out its basic functions as usual, thus facilitating the economy's response to extreme conditions. This is the result of the soundness of financial institutions at the beginning of the crisis, which was reflected in high liquidity and capital adequacy indicators as well as in the timely response of various authorities. Banco de la República lowered its policy interest rates 250 points to 1.75%, the lowest level since the creation of the new independent bank in 1991, and provided ample temporary and permanent liquidity in both pesos and foreign currency. The Office of the Financial Superintendent of Colombia, in turn, adopted prudential measures to facilitate changes in the conditions for loans in effect and temporary rules for rating and loan-loss provisions. Finally, the national government expanded the transfers as well as the guaranteed credit programs for the economy. The supply of real credit (i.e. discounting inflation) in the economy is 4% higher today than it was 12 months ago with especially marked growth in the housing (5.6%) and commercial (4.7%) loan portfolios (2.3% in consumer and -0.1% in microloans), but there have been significant changes over time. During the first few months of the quarantine, firms increased their demands for liquidity sharply while consumers reduced theirs. Since then, the growth of credit to firms has tended to slow down, while consumer and housing credit has grown. The financial system has responded satisfactorily to the changes in the respective demands of each group or sector and loans may grow at high rates in 2021 if GDP grows at rates close to 4.6% as the technical staff at the Bank expects; but the forecasts are highly uncertain. After the strict quarantine implemented by authorities in Colombia, the turmoil seen in March and early April, which was evident in the sudden reddening of macroeconomic variables on the risk heatmap in Graph A,[1] and the drop in crude oil and coal prices (note the high volatility registered in market risk for the region on Graph A) the local financial markets stabilized relatively quickly. Banco de la República’s credible and sustained policy response played a decisive role in this stabilization in terms of liquidity provision through a sharp expansion of repo operations (and changes in amounts, terms, counterparties, and eligible instruments), the purchases of public and private debt, and the reduction in bank reserve requirements. In this respect, there is now abundant aggregate liquidity and significant improvements in the liquidity position of investment funds. In this context, the main vulnerability factor for financial stability in the short term is still the high degree of uncertainty surrounding loan quality. First, the future trajectory of the number of people infected and deceased by the virus and the possible need for additional health measures is uncertain. For that reason, there is also uncertainty about the path for economic recovery in the short and medium term. Second, the degree to which the current shock will be reflected in loan quality once the risk materializes in banks’ financial statements is uncertain. For the time being, the credit risk heatmap (Graph B) indicates that non-performing and risky loans have not shown major deterioration, but past experience indicates that periods of sharp economic slowdown eventually tend to coincide with rises in non-performing loans: the calculations included in this report suggest that the impact of the recession on credit quality could be significant in the short term. This is particularly worrying since the profitability of credit establishments has been declining in recent months, and this could affect their ability to provide credit to the real sector of the economy. In order to adopt a forward-looking approach to this vulnerability, this Report presents several stress tests that evaluate the resilience of the liquidity and capital adequacy of credit institutions and investment funds in the event of a hypothetical scenario that seeks to simulate an extreme version of current macroeconomic conditions. The results suggest that even though there could be strong impacts on the credit institutions’ volume of credit and profitability under such scenarios, aggregate indicators of total and core capital adequacy will probably remain at levels that are above the regulatory limits over the horizon of a year. At the same time, the exercises highlight the high capacity of the system's liquidity to face adverse scenarios. In compliance with its constitutional objectives and in coordination with the financial system's security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions that are necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth operation of the payment systems. Juan José Echavarría Governo

    Production of upgraded metallurgical-grade silicon for a low-cost, high-efficiency, and reliable PV technology

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    Upgraded metallurgical-grade silicon (UMG-Si) has the potential to reduce the cost of photovoltaic (PV) technology and improve its environmental profile. In this contribution, we summarize the extensive work made in the research and development of UMG technology for PV, which has led to the demonstration of UMG-Si as a competitive alternative to polysilicon for the production of high-efficiency multicrystalline solar cells and modules. The tailoring of the processing steps along the complete Ferrosolar’s UMG-Si manufacturing value chain is addressed, commencing with the purification stage that results in a moderately compensated material due to the presence of phosphorous and boron. Gallium is added as a dopant at the crystallization stage to obtain a uniform resistivity profile of ∼1 Ω cm along the ingot height. Defect engineering techniques based on phosphorus diffusion gettering are optimized to improve the bulk electronic quality of UMG-Si wafers. Black silicon texturing, compatible with subsequent gettering and surface passivation, is successfully implemented. Industrial-type aluminum back surface field (Al-BSF) and passivated emitter and rear cell (PERC) solar cells are fabricated, achieving cell efficiencies in the range of those obtained with conventional polysilicon substrates. TOPCon solar cell processing key steps are also tested to further evaluate the potential of the material in advanced device architectures beyond the PERC. Degradation mechanisms related to light exposure and operation temperature are shown to be insignificant in UMG PERC solar cells when a regeneration step is implemented, and PV modules with several years of outdoor operation demonstrated similar performance to reference ones based on poly-Si. Life cycle analysis (LCA) is carried out to evaluate the environmental impact of UMG-based PV technology when compared to poly-Si-based technology, considering different scenarios for both the manufacturing sites and the PV installations

    Libro digital de Matemática Básica: (MA420) Línea Ingeniería

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    Recurso académico elaborado por el Departamento de Ciencias para el curso de Matemática Básica para ingeniería (MA420). Universidad Peruana de Ciencias Aplicadas.Este texto, al cual llamaremos libro digital, está diseñado para utilizarse en el curso de Matemática Básica para ingeniería (MA420), curso que se dicta en la Universidad Peruana de Ciencias Aplicadas (UPC). El contenido obedece a un objetivo fundamental: preparar adecuadamente a los alumnos para llevar con éxito los cursos siguientes en cada una de sus carreras y por lo tanto contiene temas que servirán de base a los mismos, además que la metodología usada obedece a un aprestamiento que el alumno adquirirá para lograr su adaptación al proceso universitario

    Intensification of Antiretroviral Therapy with a CCR5 Antagonist in Patients with Chronic HIV-1 Infection: Effect on T Cells Latently Infected

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    Objective: The primary objective was to assess the effect of MVC intensification on latently infected CD4+ T cells in chronically HIV-1-infected patients receiving antiretroviral therapy. Methods: We performed an open-label pilot phase II clinical trial involving chronically HIV-1-infected patients receiving stable antiretroviral therapy whose regimen was intensified with 48 weeks of maraviroc therapy. We analyzed the latent reservoir, the residual viremia and episomal 2LTR DNA to examine the relationship between these measures and the HIV-1 latent reservoir, immune activation, lymphocyte subsets (including effector and central memory T cells), and markers associated with bacterial translocation. Results: Overall a non significant reduction in the size of the latent reservoir was found (p = 0.068). A mean reduction of 1.82 IUPM was observed in 4 patients with detectable latent reservoir at baseline after 48 weeks of intensification. No effect on plasma residual viremia was observed. Unexpectedly, all the patients had detectable 2LTR DNA circles at week 24, while none of them showed those circles at the end of the study. No changes were detected in CD4+ or CD8+ counts, although a significant decrease was found in the proportion of HLA-DR+/CD38+ CD4+ and CD8+ T-cells. LPS and sCD14 levels increased. Conclusions: Intensification with MVC was associated with a trend to a decrease in the size of the latent HIV-1 reservoir in memory T cells. No impact on residual viremia was detected. Additional studies with larger samples are needed to confirm the results

    POR UNA CULTURA DE PAZ: UNA MIRADA DESDE LAS CIENCIAS DE LA CONDUCTA

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    En
 virtud
 de
 lo
 anterior,
 los
 estudiosos
 de
 las
 ciencias
 de
 la
 conducta
 
de
 la
 Universidad
Autónoma 
del
 Estado 
de 
México,

ante 
la
persistencia
 y 
proliferación
 de
 estos 
hechos
 en
 diversas
 partes
 del
Mundo
 y
 de
 nuestro 
país 
en 
particular, se
 convocó
 a
 los
 estudiosos
 interesados
 y
 a
 la
 sociedad
 en
 general
 a
 presentar
 trabajos
 para
 analizar,
 debatir
 y
 proponer
 estrategias
 de
 acción
 y
 dirección,
 que
 fortalezcan
 una
 convivencia y bienestar con sentido humanista para una cultura de paz. El
 presente
 texto
 es
 producto
 de 
esta convocatoria 
que
 recoge 
los
trabajos 
de 

los
 interesados 
en 
la
 temática,

 de
 diferentes 
países
(España,
Argentina,
Cuba,
Brasil,
Costa
 Rica
 y
 México)
 retomando
 con
 ello
 sus
 experiencias
 relativas
 al
 estudio,
 análisis,
 comprensión
 e
 instrumentación
 de
 la
 cultura
 de
 paz
 en
 los
 distintos
 ámbitos
 institucionales
 en
 los
 que
 participan:
 educativo,
 salud,
 penitenciario,
 social,
laboral,
familia,
alimentario,
psicológico,
por 
mencionar 
algunos.
 El
 presente
 libro,
 propicia
 un
 espacio
 de
 reflexión,
 diálogo
 y
 posicionamiento
 de
 las 
ciencias 
de 
la 
conducta
 para 
la 
apropiación,
análisis,
debate
 y 
propuestas 
que
 fortalezcan 
una
 cultura
 de 
paz
 a
través
 de 
la
 convivencia 
y
 el 
bienestar
 social 
con
 sentido 
humanista.
El
 sistema 
económico
 neoliberal
 y 
el 
proceso
 de 
globalización 
han
 contribuido
al
 logro
 de
 avances
 significativos
 en
 la
 ciencia
 y
 la
 tecnología,
 pero
 también
 han
 propiciado
 la
 polarización
 de
 las
 sociedades
 lo
 que
 ha
 impactado
 de
 manera
 negativa
 a
 la
 sociedad
 en
 su
 conjunto,
 pero
 en
 mayor
 medida
 a
 los grupos
 vulnerables. Dicha
 polarización
 ha
 traído
 consigo
 un
 desarrollo
 desigual
 del
 mundo
 que
 se
 expresa
 de
 diferentes
 maneras
 tanto
 en
 países
 desarrollados
 como
 en
 los
 llamados
 del
 tercer
 mundo,
 en
 donde
 no
 están
 satisfechas
 las
 necesidades
 humanas 
elementales
 de
 todos 
los
sectores 
de 
la 
población,
siempre 
falta 
algo. 
Si 
a
 esto 
le
 sumamos 
los
conflictos
 internacionales por
 diferentes
 motivos
 que
 enfrentan
 algunas
 naciones,
 una
 insuficiente
 cobertura
 educativa
 y
 de
 salud,

 desempleo
 y
 pobreza 
extrema,
 entre 
otras
 cosas; 
estamos
 frente
 a
retos 
de
 gran
 envergadura
 para
 los
 gobiernos,
 para
 los
 estudiosos
 y
 para
 la
 sociedad
 civil
 en
 general. Uno 
de 
los
 intentos
 para
 frenar 
y prevenir 
la
 agudización
 de 
estas 
problemáticas
 es
 la
 cultura 
de 
paz,
cuyo
 estudio
y propuestas 
han 
ido 
avanzando 
en 
diferentes
 sentidos 
y 
de 
manera 
favorable,
el 
tema 
está 
presente 
en 
diferentes 
Organismos
 Internacionales
 como
 la
 ONU,
 la
 UNESCO,
 la
 OCDE,
 El
 Banco
 Mundial,
 entre
 otros.
 Pero
 falta 
mucho 
por 
hacer.Universidad Autónoma del Estado de Méxic

    Enfermedades crónicas

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    Adherencia al tratamiento farmacológico y relación con el control metabólico en pacientes con DM2Aluminio en pacientes con terapia de reemplazo renal crónico con hemodiálisis en Bogotá, ColombiaAmputación de extremidades inferiores: ¿están aumentando las tasas?Consumo de edulcorantes artificiales en jóvenes universitariosCómo crecen niños normales de 2 años que son sobrepeso a los 7 añosDiagnóstico con enfoque territorial de salud cardiovascular en la Región MetropolitanaEfecto a corto plazo de una intervención con ejercicio físico, en niños con sobrepesoEfectos de la cirugía bariátrica en pacientes con síndrome metabólico e IMC < 35 KG/M2Encuesta mundial de tabaquismo en estudiantes de profesiones de saludEnfermedades crónicas no transmisibles: Consecuencias sociales-sanitarias de comunidades rurales en ChileEpidemiología de las muertes hospitalarias por patologías relacionadas a muerte encefálica, Chile 2003-2007Estado nutricional y conductas alimentarias en adolescentes de 4º medio de la Región de CoquimboEstudio de calidad de vida en una muestra del plan piloto para hepatitis CEvaluación del proceso asistencial y de resultados de salud del GES de diabetes mellitus 2Factores de riesgo cardiovascular en población universitaria de la Facsal, universidad de TarapacáImplicancias psicosociales en la génesis, evolución y tratamiento de pacientes con hipertensión arterial esencialInfarto agudo al miocardio (IAM): Realidad en el Hospital de Puerto Natales, 2009-2010Introducción de nuevas TIC y mejoría de la asistencia a un programa de saludNiños obesos atendidos en el Cesfam de Puerto Natales y su entorno familiarPerfil de la mortalidad por cáncer de cuello uterino en Río de JaneiroPerfil del paciente primo-consultante del Programa de Salud Cardiovascular, Consultorio Cordillera Andina, Los AndesPrevalencia de automedicación en mujeres beneficiarias del Hospital Comunitario de Til-TiPrevalencia de caries en población preescolar y su relación con malnutrición por excesoPrevalencia de retinopatía diabética en comunas dependientes del Servicio de Salud Metropolitano Occidente (SSMOC)Problemas de adherencia farmacológica antihipertensiva en población mapuche: Un estudio cualitativoRol biológico de los antioxidantes innatos en pacientes portadores de VIH/SidaSobrepeso en empleados de un restaurante de una universidad pública del estado de São Paul

    COVID-19 vaccine failure

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    COVID-19 affects the population unequally with a higher impact on aged and immunosuppressed people. Hence, we assessed the effect of SARS-CoV-2 vaccination in immune compromised patients (older adults and oncohematologic patients), compared with healthy counterparts. While the acquired humoral and cellular memory did not predict subsequent infection 18 months after full immunization, spectral and computational cytometry revealed several subsets within the CD8+ T-cells, B-cells, NK cells, monocytes and CD45RA+ CCR7- Tγδ cells differentially expressed in further infected and non-infected individuals not just following immunization, but also prior to that. Of note, up to 7 subsets were found within the CD45RA+ CCR7- Tγδ population with some of them being expanded and other decreased in subsequently infected individuals. Moreover, some of these subsets also predicted COVID-induced hospitalization in oncohematologic patients. Therefore, we hereby have identified several cellular subsets that, even before vaccination, strongly related to COVID-19 vulnerability as opposed to the acquisition of cellular and/or humoral memory following vaccination with SARS-CoV2 mRNA vaccines.This study has been funded through Programa Estratégico Instituto de Biología y Genética Molecular (IBGM Junta de Castilla y León. Ref. CCVC8485), Junta de Castilla y León (Proyectos COVID 07.04.467B04.74011.0) and the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC's Global Health Platform (PTI Salud Global; SGL21-03-026 and SGL2021-03-038)N
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