Term structure estimation, liquidity-induced heteroskedasticity and the price of liquidity risk

Desde la publicación del trabajo de Vasicek y Fong (1982) se ha generalizado el ajuste de la estructura temporal de tipos de interés asumiendo que los rendimientos son homocedásticos. En este trabajo se muestra que dicha hipótesis no se mantiene cuando los activos presentan diferencias en liquidez, incluso cuando se trata de bonos del mismo emisor. Un bajo volumen negociado implica una mayor volatilidad. Además, la existencia de discontinuidades en la negociación del precio de los bonos producirá mayor volatilidad en aquellos que se encuentren más próximos a vencimiento. Para mostrar estos efectos, se ha trabajado con bonos del Estado español desde 1988 hasta 2010, considerando más de 700 títulos y 5.000 días observados. Con estos datos se han estimado los errores fuera de la muestra para cada día y título observados. La varianza de estos errores está negativamente correlacionada con la rotación y la duración de cada título, mientras que la media del error está directamente correlacionada con la varianza estimada. Por todo ello, en este trabajo se propone un modelo modificado de Svensson (1994) para estimar la curva de tipos de interés añadiendo un término por liquidez y estimando los parámetros por mínimos cuadrados ponderados, teniendo en cuenta la heterocedasticidad inducida por liquidezSince the seminal paper of Vasicek and Fong (1982), the term structures of interest rates have been fitted assuming that yields are cross-sectionally homoskedastic. We show that this assumption does not hold when there are differences in liquidity, even for bonds of the same issuer. Lower turnover implies higher volatility. In addition, a minimum tick size for bond price negotiation will produce higher volatility for bonds approaching their maturity dates. To show these effects, we use data for Spanish sovereign bonds from 1988 to 2010, covering more than 700 bonds and 5000 trading days. We estimate the out-ofsample error for each bond and day. The variance of these errors is found to be negatively correlated with each bond’s turnover and duration, while the mean of the errors is found to be directly correlated with the estimated variance. As a result, we propose a modified Svensson (1994) yield curve model to fit the term structure, adding a liquidity term and estimating parameters by weighted least-squared errors to take into account the liquidity induced heteroskedasticit

La asociatividad y la internacionalización de las pymes del sector textil de la Asociación Cámara de Comercio de Gamarra, 2018

La presente investigación tuvo como objetivo principal determinar la relación entre la Asociatividad y la internacionalización de las pymes del sector textil de la Asociación Cámara de Comercio de Gamarra, 2018.El análisis de la primera variable “Asociatividad” se realizó desde la “Teoría Marshalliano” y la segunda variable “Internacionalización” inicia desde la “Teoría de fases Up sala” Su metodología fue correlacional de diseño no experimental, bajo un enfoque cuantitativo y de tipo aplicada. La muestra utilizada fueron las 30 pymes del sector textil de la Asociación cámara de Comercio de Gamarra. Para realizar la recolección de datos se empleó como técnica la encuesta y como instrumento el cuestionario que fue debidamente validado por expertos y se dio confiabilidad mediante el alfa de Cronbach, conformado por un total de 12 preguntas, para la variable “Asociatividad” se realizaron 5 preguntas y para la variable “Internacionalización” se realizaron 7 preguntas. Los resultados fueron obtenidos a través del sistema SPSS de esta manera se efectuó el respectivo análisis y el contraste de hipótesis utilizando la prueba de Spearman. Se concluyó que, si existe una relación entre la Asociatividad y la internacionalización de las pymes del sector textil de la Asociación Cámara de Comercio de Gamarra,2018 esta relación es positiva y significativa

Finanzas : Planeación Financiera aplicada a Tacos el Buen Samaritano para el periodo finalizado 2016

El presente trabajo está orientado a presentar la Planeación Financiera aplicada a Tacos El Buen Samaritano para el período finalizado 2016; siendo su objetivo general, analizar la planeación financiera aplicada a Tacos El Buen Samaritano para el periodo finalizado 2016 en base a los Estados Financieros 2015. Para llevar a cabo esta planeación se utilizó los métodos de los Estados financieros proforma; consiste en utilizar un método porcentual de ventas, el cual predice las ventas para luego establecer el costo de los bienes vendidos, costos de operación y gastos de intereses en forma de porcentaje de ventas proyectadas. Los porcentajes empleados tienen cierta probabilidad de ser los porcentajes de ventas de estos renglones en el año inmediato anterior, el mejor y de uso más generalizado es método de cálculo de estimación; los valores de ciertas cuentas del balance general son estimados, en tanto que otras son acumuladas. Los Estados Financieros proforma son el camino que toman las empresas que se encuentran en desarrollo financiero para los cortos, medianos y largo plazos en su visión de crecimiento. En la proyección de ventas hubo un incremento del 5% para el primer trimestre, el 10% para el segundo trimestre y del 15% para los últimos 6 meses de operación, en los cuales se obtuvo un crecimiento del 11.43% en las unidades producidas y de la misma manera un 11.43% en los ingresos por ventas en comparación con el año base, este incremento se debe a la demanda que aumentó en los últimos meses del año. De esta manera se puede concluir que la empresa está creciendo y su rentabilidad está muy bien puesto que su endeudamiento es bajo con respecto a sus activos que posee, de manera que puede optar a financiamientos futuros si así lo desea. En fin, ésta planeación financiera busca optimizar los recursos y mejorar su desarrollo dentro del mercado en que se desenvuelve, así también permitirá mejorar la calidad de los bienes ofrecidos a los clientes, mejorando así el nivel de satisfacción de los consumidores lo que hará que la empresa sea más competitiva a nivel local y nacional

In Vivo Detection of Perinatal Brain Metabolite Changes in a Rabbit Model of Intrauterine Growth Restriction (IUGR)

Background Intrauterine growth restriction (IUGR) is a risk factor for abnormal neurodevelopment.We studied a rabbit model of IUGR by magnetic resonance imaging (MRI) and spectroscopy (MRS), to assess in vivo brain structural and metabolic consequences, and identify potential metabolic biomarkers for clinical translation. Methods IUGR was induced in 3 pregnant rabbits at gestational day 25, by 40-50% uteroplacental vessel ligation in one horn; the contralateral horn was used as control. Fetuses were delivered at day 30 and weighted. A total of 6 controls and 5 IUGR pups underwent T2-w MRI and localized proton MRS within the first 8 hours of life, at 7T. Changes in brain tissue volumes and respective contributions to each MRS voxel were estimated by semi-automated registration of MRI images with a digital atlas of the rabbit brain. MRS data were used for: (i) absolute metabolite quantifications, using linear fitting; (ii) local temperature estimations, based on the water chemical shift; and (iii) classification, using spectral pattern analysis. Results Lower birth weight was associated with (i) smaller brain sizes, (ii) slightly lower brain temperatures, and (iii) differential metabolite profile changes in specific regions of the brain parenchyma. Specifically, we found estimated lower levels of aspartate and N-acetylaspartate (NAA) in the cerebral cortex and hippocampus (suggesting neuronal impairment), and higher glycine levels in the striatum (possible marker of brain injury). Our results also suggest that the metabolic changes in cortical regions are more prevalent than those detected in hippocampus and striatum. Conclusions IUGR was associated with brain metabolic changes in vivo, which correlate well with the neurostructural changes and neurodevelopment problems described in IUGR. Metabolic parameters could constitute non invasive biomarkers for the diagnosis and abnormal neurodevelopment of perinatal origin

Las Acciones de Nulidad y el Restablecimiento del Derecho al Trabajo de los docentes del Instituto Técnico Rafael Reyes de Duitama, Boyacá

In front of the declaration of insubstantial of the educational ones of the Technical Institute Rafael Reyes of Duitama, we have that in front of the administrative act it is necessary the motivation of the same one for the releasing of noted officials provisionally in career positions, because it is not enough with a simple communication and/or notification of the decision taken by the nominator; but rather he/she should take each case in short to determine on their insubstantial. Likewise, he/she should call himself to each educational one and to explain to him the reasons that gave had finished their contract so that their right was respected to the work. The absolute discrecionalidad of the nominator is understood as the possibility of adopting administrative decisions without a justified reason exists for it, it can made a mistake with the outrage and it is not of receipt in the panorama of the contemporary constitutional right. On the other hand, the relative discrecionalidad, is unaware to the notion of the official's whim, it allows to this to appreciate the circumstances in fact and those of opportunity and convenience that surround the taking of the decision, granting him the possibility to act or of not making it, or of choosing the content of its determination, always inside the inherent general purposes to the public function and the implicit matters in the norm that authorizes the discretionary decision. In this order of ideas, leave the necessity to motivate the administrative act as the best guarantee to distinguish the discretionary of the arbitrary thing. The ponderación and classification of a fundamental right in front of other constitutional guarantees, make part of the new evolutionary generation and the change that our right but I publish bony the constitutional right lays the foundation as juridical institutions that have as only end he/she saves to keep the integrity of the fundamental rights of the humans as well as its worthy existence and the development of economic activities that allow him to this to be unwrapped as an active individual of the society and that every day it is not nurtured alone legal but also socially.Frente a la declaratoria de insubsistencia de los docentes del Instituto Técnico Rafael Reyes de Duitama, tenemos que frente al acto administrativo es necesaria la motivación del mismo para la desvinculación de funcionarios nombrados provisionalmente en cargos de carrera, pues no basta con una simple comunicación y/o notificación de la decisión tomada por el nominador; sino que se debió tomar cada caso en concreto para determinar sobre su insubsistencia. Así mismo, se debió llamar a cada docente y explicarle las razones que daban por terminado su contrato a fin de que se respetara su derecho al trabajo. La discrecionalidad absoluta del nominador es entendida como la posibilidad de adoptar decisiones administrativas sin que exista una razón justificada para ello, puede confundirse con la arbitrariedad y no es de recibo en el panorama del derecho constitucional contemporáneo. En cambio, la discrecionalidad relativa, es ajena a la noción del capricho del funcionario, le permite a éste apreciar las circunstancias de hecho y las de oportunidad y conveniencia que rodean la toma de la decisión, concediéndole la posibilidad de actuar o de no hacerlo, o de escoger el contenido de su determinación, siempre dentro de las finalidades generales inherentes a la función pública y las particulares implícitas en la norma que autoriza la decisión discrecional. En este orden de ideas, se ve la necesidad de motivar el acto administrativo como la mejor garantía para distinguir lo discrecional de lo arbitrario. La ponderación y clasificación de un derecho fundamental frente a otras garantías constitucionales, hace parte de la nueva generación evolutiva y el cambio que nuestro derecho más publico ósea el derecho constitucional cimenta como instituciones jurídicas que tienen como único fin salva guardar la integridad de los derechos fundamentales de los humanos así como su digna existencia y el desarrollo de actividades económicas que le permiten a este desenvolverse como un individuo activo de la sociedad y que cada día se nutre no solo legal sino también socialmente

Transcriptomic and Metabolomic Response to High Light in the Charophyte Alga Klebsormidium nitens

The characterization of the molecular mechanisms, such as high light irradiance resistance, that allowed plant terrestralization is a cornerstone in evolutionary studies since the conquest of land by plants played a pivotal role in life evolution on Earth. Viridiplantae or the green lineage is divided into two clades, Chlorophyta and Streptophyta, that in turn splits into Embryophyta or land plants and Charophyta. Charophyta are used in evolutionary studies on plant terrestralization since they are generally accepted as the extant algal species most closely related to current land plants. In this study, we have chosen the facultative terrestrial early charophyte alga Klebsormidium nitens to perform an integrative transcriptomic and metabolomic analysis under high light in order to unveil key mechanisms involved in the early steps of plants terrestralization. We found a fast chloroplast retrograde signaling possibly mediated by reactive oxygen species and the inositol polyphosphate 1-phosphatase (SAL1) and 3′-phosphoadenosine-5′-phosphate (PAP) pathways inducing gene expression and accumulation of specific metabolites. Systems used by both Chlorophyta and Embryophyta were activated such as the xanthophyll cycle with an accumulation of zeaxanthin and protein folding and repair mechanisms constituted by NADPH-dependent thioredoxin reductases, thioredoxin-disulfide reductases, and peroxiredoxins. Similarly, cyclic electron flow, specifically the pathway dependent on proton gradient regulation 5, was strongly activated under high light. We detected a simultaneous co-activation of the non-photochemical quenching mechanisms based on LHC-like stress related (LHCSR) protein and the photosystem II subunit S that are specific to Chlorophyta and Embryophyta, respectively. Exclusive Embryophyta systems for the synthesis, sensing, and response to the phytohormone auxin were also activated under high light in K. nitens leading to an increase in auxin content with the concomitant accumulation of amino acids such as tryptophan, histidine, and phenylalanine.España Ministerio de Ciencia e Innovación MINOTAUR (BIO2017-84066-R

Endoplasmic Reticulum Stress-Sensing Mechanism Is Activated in Entamoeba histolytica upon Treatment with Nitric Oxide

The Endoplasmic Reticulum stores calcium and is a site of protein synthesis and modification. Changes in ER homeostasis lead to stress responses with an activation of the unfolded protein response (UPR). The Entamoeba histolytica endomembrane system is simple compared to those of higher eukaryotes, as a canonical ER is not observed. During amoebiasis, an infection of the human intestine and liver by E. histolytica, nitric oxide (NO) triggers an apoptotic-like event preceded by an impairment of energy production and a loss of important parasite pathogenic features. We address the question of how this ancient eukaryote responds to stress induced by immune components (i.e. NO) and whether stress leads to ER changes and subsequently to an UPR. Gene expression analysis suggested that NO triggers stress responses marked by (i) dramatic up-regulation of hsp genes although a bona fide UPR is absent; (ii) induction of DNA repair and redox gene expression and iii) up-regulation of glycolysis-related gene expression. Enzymology approaches demonstrate that NO directly inhibits glycolysis and enhance cysteine synthase activity. Using live imaging and confocal microscopy we found that NO dramatically provokes extensive ER fragmentation. ER fission in E. histolytica appears as a protective response against stress, as it has been recently proposed for neuron self-defense during neurologic disorders. Chronic ER stress is also involved in metabolic diseases including diabetes, where NO production reduces ER calcium levels and activates cell death. Our data highlighted unique cellular responses of interest to understand the mechanisms of parasite death during amoebiasis

Sistema de processamento de imagens aéreas múlti espectrais para agricultura de precisão

Cuban agriculture has the growing need to increase its productivity. To achieve this, precision agriculture can play a fundamental role. It is necessary to develop an image processing system able to process all the crops information and calculate vegetation indexes in a satisfactory way. This will entail in accurate measurements of the nitrogen lack, the hydric stress, and the vegetal strength, among other aspects, seeking to improve the accuracy in the care of these aspects. This document reports the results of an investigation pointed to develop a procedure for capturing and processing multispectral aerial images obtained from Unmanned Aerial Vehicles [UAV]. This procedure searched to measure the vegetation indexes of sugarcane crops that may be correlated with the level of vegetal strength, the number of stems, and the foliar mass per lot. We used a USENSE-X8 UAV together with a Sequoia multispectral sensor and the QGIS processing software. The procedure was experimentally validated.La agricultura cubana tiene la necesidad creciente de aumentar su productividad, para lograrlo, la agricultura de precisión puede desempeñar un papel fundamental. Es necesario entonces desarrollar un sistema de procesamiento de imágenes capaz de procesar toda la información de los cultivos y calcular índices vegetativos de forma satisfactoria, para así medir con precisión el déficit de nitrógeno, el estrés hídrico y el vigor vegetal, entre otros aspectos, para que la atención de estos aspectos sea también precisa. Este documento reporta los resultados de una investigación dirigida al desarrollo de un procedimiento para la toma y procesamiento de imágenes multiespectrales aéreas obtenidas desde Vehículos Aéreos No Tripulados [VANT], para obtener índices vegetativos de sembrados de caña de azúcar que puedan ser correlacionados con el nivel de vigor vegetal, el número de tallos o la masa foliar por parcela. Se utilizó un VANT USENSE-X8 y sus componentes, un sensor multiespectral Sequoia y el software de procesamiento QGIS. El procedimiento fue validado de forma experimental.A agricultura cubana tem uma necessidade crescente de aumentar sua produtividade, e para isso, a agricultura de precisão pode desempenhar um papel fundamental. É necessário, portanto, desenvolver um sistema de processamento de imagens capaz de processar toda a informação dos plantios e calcular de forma satisfatória índices de vegetação, de forma de poder medir com precisão o déficit de nitrogênio, o estresse hídrico e o vigor vegetal, entre outros aspectos, para que a atenção desses aspectos também seja precisa. Este documento relata os resultados de uma pesquisa focada ao desenvolvimento de um procedimento para a obtenção e processamento de imagens aéreas múlti espectrais obtidas desde veículos aéreos não tripulados [VANT], para obter índices de vegetação de plantios de cana-de-açúcar que podem ser correlacionados com o nível de vigor vegetal, o número de hastes ou a massa foliar por parcela. Foi utilizado um VANT USENSE-X8 e seus componentes, um sensor múlti espectral Sequoia e o software de processamento QGIS. O procedimento foi validado experimentalmente

Spatiotemporal dynamics of vector-borne disease risk across human land-use gradients: examining the role of agriculture, indigenous territories, and protected areas in Costa Rica

Background Costa Rica has undergone significant changes to its forest ecosystems due, in part, to the proliferation of palm oil and other industrial agriculture operations. However, the country also boasts conservation programmes that are among the most robust in the neotropics. Consequently, gradients of anthropogenic to intact ecosystems are found throughout the country. Forest ecosystems may decrease vector-borne disease (VBD) risk by maintaining insect populations in a state of relative equilibrium; however, evidence suggests that intact forests foster biodiversity and may also amplify VBD risk in some circumstances. As a result, focal points of human-vector contact are likely idiosyncratic. This may be particularly true in indigenous territories, which have been shown to play a vital role in maintaining the ecological integrity of conservation areas. Here, we investigate the relationships between anthropogenic landscapes, indigenous territories, protected areas, and risk of VBD. Methods We quantified spatial dynamics of risk across three distinct categories of VBD in Costa Rica: emerging flaviviruses (Zika virus disease and dengue); neglected tropical diseases (cutaneous leishmaniasis and Chagas disease); and a disease nearing eradication (malaria). We collected district-level incidence data from between 2006 and 2017 and used spatial statistics to identify hotspots of elevated risk. We then quantified the associations between anthropogenic landscapes, intact forest ecosystems, and indigenous territories with both the presence and persistence of elevated transmission risk over time using multivariate hurdle models. Findings We detected clear patterns of non-random disease risk across each of the three categories of VBD. Compared with protected areas, districts with higher proportions of human-altered landscapes, particularly agricultural intensification, were at higher risk for VBD across all categories. Districts with the highest proportion of crop cover, compared with the lowest proportion, were significantly associated with the presence of hotspots for Zika virus disease (OR 15·19 [95% CI 6·19–37·26]), dengue (13·00 [7·24–23·35]), leishmaniasis (4·46 [1·18–16·84]), Chagas disease (3·09 [1·47–6·49]), and malaria (8·40 [3·56–19·83]). Interpretation A set of spatial epidemiology tools within a planetary health framework allowed for a refined understanding of the risk of VBD of global public health significance in a biodiversity hotspot. Our findings may be used to better guide targeted public health disease surveillance, control, and prevention programmes. Additional research to understand the role that socioeconomic factors play in the variating VBD risk would contribute additional context to these findings, as these factors are often also spatially associated