3,244 research outputs found
Ultra-Broadband Directional Couplers Using Microstrip with Dielectric Overlay in Millimeter-Wave Band
Nowadays, millimeter-wave systems are being a key factor to develop wide band applications. In this paper, a directional coupler in millimeter-wave band using dielectric overlay is presented. This leads us to technology aspects, in directional coupler design, are key points to achieve the proper response of the circuit. The coupler proposed in this paper covers the 15-45 GHz band and its response has 15-dB coupling-level, 1-dB coupling-ripple and a reflection coefficient better than 10 dB
Inter-rater and intra-rater reliability of the extended TUG test in elderly participants
Background: To analyse the reliability, variance and execution time of the Extended Timed Up and Go (Extended
TUG) test in three age groups of elderly participants (G1: 55–64 years; G2: 65–74 years; G3: 75–85 years).
Methods: An analytical cross-sectional study of 114 recruited participants (63 women) of average age 70.17 (± 7.3) years
was undertaken. Each participant performed the Extended TUG three consecutive times, with a rest break between tests of
120 s. Both the intragroup and intergroup reliability of the measurements in the Extended TUG were analysed.
Results: The reliability of the Extended TUG test is excellent for the first and second decades but drops down to good for
the third decade. Specifically, intragroup reliability ranged from 0.784 for G3 to 0.977 for G1 (G2 = 0.858). Intergroup reliability,
compared with intragroup reliability, was slightly lower, ranging between 0.779 for G3 and 0.972 for G1 (G2 = 0.853).
Conclusion: The reliability of the Extended TUG test progressively decreases with increasing age, being excellent for the
younger age groups and good for the oldest age group
Igualdad de género percibida en el reparto de cuidados y salud mental: impacto de la crisis sanitaria por COVID-19 en una muestra de mujeres andaluzas
The restrictions during COVID-19 seem to have had an unequal impact on the mental health and habits of the population in terms of gender. The literature states that crises such as this have a more negative impact on women. We explored perceived overload due to household chores and informal caregiving in a sample of Andalusian women, their perception of an increase in this overload after the pandemic, and its possible effect on mental health. To do this, we administered an online retrospective questionnaire to explore the perception of 166 women on care economy variables by estimating hours, effort, overload, and sharing of chores at three different times: before the onset of the pandemic, during lockdown, and at the time of data collection (one year after lockdown). We also measured depression, anxiety, stress, and life satisfaction at the time of data collection through validated scales. Results showed that women estimated significantly more time and effort on household chores and caregiving for the lockdown period. The retrospective estimation of the sharing of tasks was similar over the three moments but women perceived that they did more than their heterosexual partners. One in four women perceived an increase in caregiving overload after the pandemic. Women who felt mental overload due to caregiving scored higher in depression than those who felt physical overload. Considering these findings, and despite the limitations of this study, the pandemic may have led to an increase in informal caregiving overload for many women. Furthermore, the relation between depression and overload one year after lockdown was demonstrated. Measures are required to reduce the impact of gender in crises by designing prevention policies and programs that promote co-responsibility.Las restricciones vividas durante la COVID-19 parecen haber causado un impacto diferencial de género en la salud mental y en los hábitos de gran parte de la población. Asimismo, la literatura indica que las situaciones de crisis como la vivida tienen peor impacto en las mujeres. El objetivo de este trabajo es explorar la sobrecarga percibida por las tareas del hogar y cuidados informales en una muestra de mujeres andaluzas, su percepción de un incremento en la misma tras la pandemia, y su posible relación con variables de salud mental. Para ello se administró un cuestionario online para explorar la percepción de 166 mujeres en variables de economía de cuidados estimando retrospectivamente las horas, esfuerzo, sobrecarga y reparto de tareas del hogar para el momento de recogida de datos (un año tras el confinamiento), para el momento previo al inicio de la pandemia y durante el confinamiento. También se administraron instrumentos validados para medir depresión, ansiedad, estrés y satisfacción vital en el momento de recogida de datos. Los resultados mostraron una percepción de mayor dedicación y esfuerzo debido a los cuidados y tareas del hogar estimado para el momento de confinamiento. El reparto de tareas se estimó similar para los tres momentos sobre los que se preguntó, y percibieron que ellas hacían más estas tareas que sus parejas heterosexuales. Una de cada cuatro mujeres percibió un aumento de la sobrecarga debida a cuidados tras la pandemia y los niveles de depresión fueron mayores en mujeres que sentían una sobrecarga mental debida a los cuidados, por encima de quien identificó sobrecarga física. Aun considerando las limitaciones de este trabajo, la pandemia ha podido suponer un incremento en la sobrecarga por los cuidados informales para muchas mujeres y, evidenciada la relación entre depresión y sobrecarga, podría entenderse que esta relación también se diera durante el confinamiento. Se requieren medidas que reduzcan el impacto de género en situaciones de crisis y políticas y programas de prevención que fomenten la corresponsabilidad.This work has been funded by Fundación María Fulmen (Sevilla) within their Third Call for Grants for Projects Aimed at Women Promotion (2021) [III Convocatoria de ayudas 2021 a proyectos dirigidos a la promoción de mujeres]
Turismo y desarrollo en destinos costeros de la Provincia de Buenos Aires. Una aplicación en Santa Clara del Mar, Argentina
El siglo XX es testigo del surgimiento de diferentes urbanizaciones con fines turísticos, localizadas a lo largo de la costa marítima de la Provincia de Buenos Aires. Algunas se originan en forma espontánea; en cambio, otras son planificadas. En ambas aparece la figura del fundador, quien actúa como promotor buscando inversores para conformar una nueva comunidad, que actúan como pioneros atraídos por el proyecto urbano turístico. Entre las urbanizaciones costeras se selecciona la localidad de Santa Clara del Mar, perteneciente al Partido de Mar Chiquita (Argentina), donde el desarrollo urbano turístico espontáneo y acelerado en la última década genera un fuerte impacto ambiental, social y económico. Ante esta situación se plantea la necesidad de reflexionar sobre las acciones que deberían concertarse entre los diferentes actores sociales para revertir los efectos negativos y facilitar la máxima contribución del turismo al desarrollo local. La búsqueda de una respuesta a esta problemática permitió la formulación del proyecto de investigación titulado: "Turismo y desarrollo en destinos costeros de la Provincia de Buenos Aires", considerando a la localidad de Santa Clara del Mar como la unidad de análisis. La investigación fue realizada por el Grupo Turismo y Territorio, Espacios Naturales y Culturales, de la Facultad de Ciencias Económicas y Sociales de la Universidad Nacional de Mar del Plata. Las actividades se concretaron durante el período 2012/2014. El objetivo de la investigación se centra en la realización de un diagnóstico de la situación actual y una proposición de Desarrollo Turístico para la localidad en estudio, aplicando una perspectiva teórica que combina el enfoque sistémico con el análisis multidimensional, considerando cuestiones ambientales, económicas, culturales y políticas. La propuesta se fundamenta en los principios de la investigación-acción, contemplando instancias de participación de los actores locales. La metodología se basa en la triangulación de datos cuantitativos y cualitativos, destacando como técnicas de recolección de datos la implementación de entrevistas, encuestas, tareas de observación de campo y relevamiento de información. Por otra parte, se consultan diferentes fuentes bibliográficas, cartográficas, gráficas, virtuales y documentales que permiten un mayor acercamiento a la problemática en estudio. A partir de los resultados y conclusiones obtenidos y en continuidad con las acciones realizadas destinadas para la comunidad, en el ámbito institucional se aspira generar una transferencia directa a los actores locales, y en el ámbito académico, una propuesta teórico-metodológica de aplicación de un modelo de desarrollo turístico que favorezca el desarrollo local en destinos turísticos costeros.Fil: Benseny, Graciela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: González, María Graciela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Padilla, Noelia Aymara. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Castellucci, Daniela I. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Muñoz, María Julia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Benseny, Graciela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina
Descripción de la evolución del microrrelieve en función de la precipitación acumulativa mediante cuatro índices
Numerical study of the geometry of the phase space of the Augmented Hill Three-Body problem
The Augmented Hill Three-Body problem is an extension of the classical Hill problem that, among other applications, has been used to model the motion of a solar sail around an asteroid. This model is a 3 degrees of freedom (3DoF) Hamiltonian system that depends on four parameters. This paper describes the bounded motions (periodic orbits and invariant tori) in an extended neighbourhood of some of the equilibrium points of the model. An interesting feature is the existence of equilibrium points with a 1:1 resonance, whose neighbourhood we also describe. The main tools used are the computation of periodic orbits (including their stability and bifurcations), the reduction of the Hamiltonian to centre manifolds at equilibria, and the numerical approximation of invariant tori. It is remarkable how the combination of these techniques allows the description of the dynamics of a 3DoF Hamiltonian system
Genetic Structure Analysis of the Pura Raza Español Horse Population through Partial Inbreeding Coefficient Estimation
The aim of this work was to analyze genetic parameters such as the inbreeding coe cient
(F), relatedness coe cient (AR) and partial inbreeding coe cient (Fij) of the whole PRE population,
and the ancestors which account for 50% of the total genetic variability of the current population,
from genealogical information. The average F of the whole PRE population (328,706 animals) has
decreased from 8.45% to 7.51% in the least 20 years. The Fij was estimated for the whole PRE
population, resulting in a database of 58,772,533 records containing one record for each Fij that each
animal receives from a certain common ancestor (CA). A total of 10,244 CAs contributed to the Fij
with an average of 5370 descendants, with each descendant having an average of 170 CAs. Over the
generations, the number of CAs has increased, while the proportion of Fij by each one has decreased.
In addition, the contributions of the more influential ancestors have changed. The increased census,
the limited use of artificial insemination and our increased knowledge about inbreeding depression
and the animals’ breeding values allow breeders to select horses more for their functionality and
conformation than for their pedigree reputation, which is the cause of all these changes
Evaluating the psychometric properties of the Exercise Dependence Scale-Revised (EDS-R) in a Spanish Sample.
Introduction: There are several instruments to evaluate behavioural addictions. Furthermore, several
specific scales have been developed to assess various aspects of exercise dependence. Nevertheless,
in Spain there is a lack of specific instruments designed to assess exercise dependence.
Objective: This study aims to examine the psychometric properties of a Spanish version of the Exercise
Dependence Scale-Revised.
Method: 175 university students who were regular exercisers (m=59.11, sd=15.89) took part in the
study. They were requested to complete the eds-r, as well as the General Addiction Scale. The requirement
to take part in the study was to exercise a minimum of four times per week.
Results: Findings provide initial support for the psychometric properties of the scale as its internal
consistency (Cronbach’s alpha: 0.907), and construct and convergent validity with the eag-rc (r=.559;
p<.001) are adequate. In addition, its structure did not need to be modified, as it kept the 21 original
items from the American version. Factor analysis yielded a five-factor structure (tolerance, loss of control,
continuity, intensity, and withdrawal symptoms) which differ from the ones obtained in the original
(American) and French versions where seven factors were obtained. This correlated five-factor model
explains 50% of the variance.
Conclusion: This Spanish eds-r, which presents adequate psychometric properties, will provide researchers
and clinicians with specific data on this screening tool for assessing exercise dependence.
Further research is needed to confirm the current results and check its validity both in research and
clinical practice.2017-1
Protected land enhances the survival of native aquatic macrophytes and limits invasive species spread in the Panama Canal
1. This study examined whether protected land in a tropical reservoir's catchment can promote the survival of native aquatic plants (macrophytes) and limit the spread of invasive alien plant species (macrophyte IAS), which can threaten native wildlife and require expensive remediation. As the number of tropical river dams is expected to increase in the coming decades to meet societal demands, it is crucial to explore solutions for preserving aquatic biodiversity.
2. The study used a before–after–control–intervention design, based on monitoring data and long-term sedimentological, climatic and ecological records from both lake and river zones adjacent to protected and unprotected lands around the 100-year-old Gatun Lake in the Panama Canal, Panama. The research examined the impact of impoundment and the invasion of Pontederia crassipes (water hyacinth) and Hydrilla verticillata (water thyme) on native macrophyte communities and environmental variables.
3. Lake zones adjacent to protected lands had lower nutrient concentrations, greater variations in water depth profiles and reduced fluctuations in water chemistry than lake zones outside areas of land protection. In addition, the results showed that whereas zones adjacent to unprotected land became dominated by macrophyte IAS, lake zones adjacent to protected areas were more resilient to the spread of macrophyte IAS and were able to maintain viable populations of native pre-dam species for >100 years.
4. This study indicates that protecting land adjacent to tropical reservoirs could be a cost-effective solution for preserving aquatic macrophyte biodiversity by retaining nutrients, stabilizing water chemistry, providing habitat heterogeneity and protecting native vegetation, while still supporting terrestrial conservation goals. These findings could aid in planning measures for the hundreds of proposed dam projects across lowland tropical areas and provide new insights into best practices for enhancing river ecosystem resilience
Goodness-of-fit test for point processes first-order intensity
Modelling the first-order intensity function is one of the main aims in point process theory.
An appropriate model describes the first-order intensity as a nonparametric function of spatial
covariates. A formal testing procedure is presented to assess the goodness-of-fit of this model,
assuming an inhomogeneous Poisson point process. The test is based on a quadratic distance
between two kernel intensity estimators. The asymptotic normality of the test statistic is proved
and a bootstrap procedure to approximate its distribution is suggested. The proposal is illustrated
with two applications to real data sets, and an extensive simulation study to evaluate its finitesample
performance.Grant PID2020-116587GB-I00 funded by MCIN/AEI/10.13039/50110001103
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