Cochlear Implantation in Patients with Neurofibromatosis Type 2 and Patients with Vestibular Schwannoma in the Only Hearing Ear

Cochlear implants are a new surgical option in the hearing rehabilitation of patients with neurofibromatosis type 2 (NF2) and patients with vestibular schwannoma (VS) in the only hearing ear. Auditory brainstem implant (ABI) has been the standard surgical treatment for these patients. We performed a literature review of patients with NF2 and patients with VS in the only hearing ear. Cochlear implantation (CI) provided some auditory benefit in all patients. Preservation of cochlear nerve integrity is crucial after VS resection. Results ranged from environmental sound awareness to excellent benefit with telephone use. Promontory stimulation is recommended although not crucial. MRI can be performed safely in cochlear implanted patients

Feasibility and reliability of a Physical Fitness test battery in individuals with Down Syndrome

Background: Down syndrome (DS) is a genetic disorder that occurs because of an abnormal division between cells that results in an extra copy of chromosome 21. Some studies show that physical exercise in people with DS increases some cognitive capacities, such as memory, and improves the quality of life. Aim: The main aim of this study was to perform an analysis of the reliability and feasibility of the SAMU-Disability Fitness (DISFIT) battery in adults with DS. Methods: A cross-sectional study with a test–retest design was performed in a maximum interval of 2 weeks in 37 subjects (11 women and 26 men) aged between 21 and 58 years old with DS. Eight field-based fitness tests were proposed to assess the physical fitness (PF) of adults with DS: Body Mass Index (BMI), Waist Circumference (WC), the Timed Up and Go test (TUG), the Deep Trunk Flexibility test (DTF), the Hand Grip test (HG), the Timed Stand Test (TST), the 30-s Sit-Up (SUP) and the 6-Min Walk Test (6MWT). Results: The intra-class correlation coefficient (ICC) in all the tests was good and high (>0.80), except for the 6MWT, whose reliability was fair. Conclusion: The SAMU-DISFIT battery is a reliable and feasible physical fitness battery which has been created with the purpose of establishing tests which measure the four basic components of PF (flexibility, cardiorespiratory fitness, musculoskeletal fitness and motor fitness) in adults with D

Nature or nurture? Clues from the distribution of specific star formation rates in SDSS galaxies

This work investigates the main mechanism(s) that regulate the specific star formation rate (SSFR) in nearby galaxies, cross-correlating two proxies of this quantity -- the equivalent width of the \Ha\ line and the $(u-r)$ colour -- with other physical properties (mass, metallicity, environment, morphology, and the presence of close companions) in a sample of $\sim82500$ galaxies extracted from the Sloan Digital Sky Survey (SDSS). The existence of a relatively tight `ageing sequence' in the colour-equivalent width plane favours a scenario where the secular conversion of gas into stars (i.e. `nature') is the main physical driver of the instantaneous SSFR and the gradual transition from a `chemically primitive' (metal-poor and intensely star-forming) state to a `chemically evolved' (metal-rich and passively evolving) system. Nevertheless, environmental factors (i.e. `nurture') are also important. In the field, galaxies may be temporarily affected by discrete `quenching' and `rejuvenation' episodes, but such events show little statistical significance in a probabilistic sense, and we find no evidence that galaxy interactions are, on average, a dominant driver of star formation. Although visually classified mergers tend to display systematically higher EW(H$\alpha$) and bluer $(u-r)$ colours for a given luminosity, most galaxies with high SSFR have uncertain morphologies, which could be due to either internal or external processes. Field galaxies of early and late morphological types are consistent with the gradual `ageing' scenario, with no obvious signatures of a sudden decrease in their SSFR. In contrast, star formation is significantly reduced and sometimes completely quenched on a short time scale in dense environments, where many objects are found on a `quenched sequence' in the colour-equivalent width plane.Comment: 18 pages, 9 figure

Why consumers purchase organic products? The role of environment, health and age

El mercado de productos ecológicos está aumentando en todo el mundo, especialmente en la categoría de los alimentos, en particular de productos orgánicos. El objetivo de este estudio es entender mejor porque los consumidores compran productos orgánicos, profundizando en su preocupación ambiental, conciencia de salud y edad. La evidencia empírica se basa en una encuesta online, utilizando una muestra de 279 compradores habituales de productos orgánicos en España y Portugal. Los resultados muestran que existe una relación positiva entre preocupación ambiental, conciencia de salud y comportamiento de compra verde. La preocupación ambiental es más fuerte que la salud para explicar esta relación. También la edad es un predictor de la compra y los consumidores mayores de 35 años compran más productos orgánicos que los más jóvenes. Para los profesionales de marketing, el estudio permite desarrollar mejores estrategias de marketing para atraer y retener a estos consumidores.The market of green products is increasing all over the world, especially in food category that shows a great demand for biologic and organics. The aim of this study is to better understand the why consumers buy organic products, more specifically environmental concern, health consciousness and age The empirical evidence is based on an online survey, using a sample of 279, regular shoppers of organic products in Portugal and Spain. The results show there is a positive relation between environmental concern, health consciousness and green purchase behavior. Environmental concern is stronger than health to explain this relation. Also age is a predictor of green purchase behavior and older consumers with more than 35 years purchase more organics than younger consumers. For managers and marketers, the study enables to develop better marketing strategies to address these consumers and to enhance environmental concern, health and age to foster organics consumption

Minimización del makespan para el problema de máquinas paralelas no relacionadas con tiempos de setup dependientes de la secuencia mediante un algoritmo híbrido VNS/ACO*

This paper proposes a hybrid heuristic that combines Variable Neighborhood Search (VNS) with Ant Colony Optimization (ACO) to solve the scheduling problem of nonrelated parallel machines with sequence dependent setup times in order to minimize the makespan. The Variable Neighborhood Search is proposed to solve the scheduling problem with a descending scheme in a first phase, with an ACO algorithm, which successively reorder the jobs in the machine with the largest makespan in a second phase. An experimental study was performed using test problems from the literature showing that the second phase of the algorithm improves the solution obtained in the first phase. The results obtained are also compared with other methods in the literature proving to be a competitive method.Se propone una heurística híbrida combinando Variable Neighborhood Search (VNS) y Ant Colony Optimization (ACO) para resolver el problema de programación de máquinas paralelas no relacionadas con tiempos de preparación dependientes de la secuencia con el objetivo de minimizar el makespan. La búsqueda en entornos variables se propone con un esquema descendente resolviendo en una primera etapa el problema de programación de los trabajos a las máquinas, y luego, en una segunda etapa, un algoritmo ACO, reordena sucesivamente los trabajos en la máquina de mayor makespan. Se realizan pruebas experimentales sobre un conjunto de problemas de prueba de la literatura, mostrando que al aplicar la segunda etapa de la metaheurística propuesta se mejoran las soluciones obtenidas en la primera etapa del algoritmo y que al comparar los resultados obtenidos con otros métodos de la literatura resulta ser un método competitivo.&nbsp

Asymmetric collateral requirements and output composition

This paper studies how investment and production in an economy is allocated across sectors when they face asymmetric financial conditions. Namely, when investors in one sector may run projects with higher loan-to-values than in another sector. Investors decide where to invest based on total rents and face a trade-off. While they may run larger projects in the sector with the best financial conditions, unit rents in this sector are lower than in the other sector due to a pledgeability premium. The level of interest rates affects this trade-off and therefore investors' endogenous segmentation across sectors. The effect is non-monotonic. When interest rates are high, projects are small and the differences in unit rents across sectors dominate the differences in project sizes. In this case, a drop in interest rates, move investors toward the most productive sector. Instead, when interest rates are low, projects are large, but much larger in the sector with the best financial conditions. In this case, the differences in project sizes across sectors dominate the differences in unit rents and a drop in interest rates moves investors towards the least productive sector but with the best access to external funding. We find that this hump-shaped relationship between interest rates and the share of investors allocated to a given sector may translate into a similar hump-shaped relationship between interest rates and the ratio of aggregate investment across sectors. Instead, in a model without financial asymmetries across sectors both relationships are monotonic and do not exhibit a hump. We claim that this paper provides helpful insights to understand the pattern of sectoral reallocation of investment and production observed in some OECD countries recentl

El efecto de factores económicos y culturales en la actividad emprendedora: un enfoque a través de modelos de producción con frontera

The objective of this paper is to analyse how the economic conditions and the cultural values of a country influence its level of entrepreneurial activity. To this end, panel data is utilised. An innovative approach is applied, which adapts itself to the fact that the cultural values remain fairly stable over time, while the economic conditions are changeable. Specifically, a stochastic frontier production model is set in which the changeable economic conditions determine the frontier (maximum) for the entrepreneurship rate of a country, while the stable prevailing cultural values explain the level of efficiencyinefficiency. Specifically, embeddedness is the cultural value that has the strongest relationship with the level of efficiencyEl objetivo del trabajo es analizar cómo influyen las condiciones económicas y los valores culturales de un país en su actividad emprendedora, utilizando un panel de datos. Se aplica un enfoque novedoso, que se adapta al hecho de que los factores culturales son bastante estables en el tiempo, mientras que las condiciones económicas son cambiantes. Concretamente, se plantea un modelo de producción con frontera, en el que las condiciones económicas (cambiantes) determinan la frontera máxima para la tasa de emprendimiento de un país, mientras que los valores culturales predominantes (estables) explican el nivel de eficiencia-ineficiencia. En concreto, el arraigo es el valor cultural que presenta la relación más fuerte con el nivel de eficienci

El efecto de la distribución a priori en modelos con frontera estocástica. Comparación con máxima verosimilitud

En este trabajo se analizan y comparan las propiedades de los estimadores máximo verosímil y bayesiano en el modelo de producción con frontera estocástica a través de un estudio de tipo Monte Carlo. En el caso bayesiano, se presta especial atención al efecto que tiene la elección del hiperparámetro que determina la eficiencia mediana de la distribución a priori. Los resultados muestran un mejor comportamiento de la estimación bayesiana, salvo en el caso poco probable de que se asigne un hiperparámetro muy alejado del valor real de la población.In this paper, the maximum likelihood and the Bayesian methodologies are analysed and compared through a Monte Carlo study in the setting of half–normal stochastic frontier production models. In the Bayesian case, special emphasis is placed on the effect that the choice of the hyperparameter that determines the prior median efficiency has on the estimations. The results show a better behaviour of the Bayesian estimation, except in the unlikely case in which researchers assign a value to the aforementioned hyperparameter which greatly differs from its actual value