105 research outputs found
Examining the Performance of Islamic and Conventional Stock Indices: A Comparative Analysis
Islamic indices encompass different fundamental principles to those held by conventional ones, which directs attention onto comparative financial performance. This paper offers a comprehensive performance comparison between Islamic indices and conventional indices, based on four main markets: worldwide, the US, Europe, and Asia-Pacific for the period of 2007 and 2017 through financial ratio comparison and also the CAPM-EGARCH model. The main finding shows that Islamic indices yield higher average returns and lower risks during the 2007-2009 and 2013-2017 periods for all four markets, compared with respective conventional markets. During 2009-2013 period, the comparison proves inconclusive, since Islamic indices demonstrate better performance in European and Asia-Pacific markets, while conventional indices operate at an enhanced level within other markets. Overall, Islamic indices outperformed conventional indices during the global financial crisis period (2007-2009) and the latter post-crisis phase (2013-2017), especially in the European and Asia-Pacific markets
Confined photon modes with triangular symmetry in hexagonal microcavities in 2D photonic Crystals
We present theoretical and experimental studies of the size and thickness
dependencies of the optical emission spectra from microcavities with hexagonal
shape in films of two-dimensional photonic crystal. A semiclassical plane-wave
model, which takes into account the electrodynamic properties of quasi-2D
planar photonic microcavity, is developed to predict the eigenfrequencies of
the confined photon modes as a function of both the hexagon-cavity size and the
film thickness. Modes with two different symmetries, triangular and hexagonal,
are critically analyzed. It is shown that the model of confined photon modes
with triangular symmetry gives a better agreement between the predicted
eigenmodes and the observed resonances.Comment: 14 pages, 6 figure
eCOMMONtech: plataforma sofrware para monitorización del balance de Gases de Efecto Invernadero en el Marco de Mecanismos de Desarrollo Limpio Forestales y Proyectos REDD+
La monitorización de las condiciones que debe cumplir un área forestal en proyectos MDL o REDD de manera tradicional, es decir, mediante mediciones y controles in situ, conlleva unos costes difÃciles de asumir. Por ello, se ha planteado el desarrollo de una metodologÃa capaz de integrar tecnologÃas orientadas a la realización de inventarios de carbono en áreas forestales de paÃses en vÃas de desarrollo, mediante la utilización de diferentes tecnologÃas (sensorización ambiental, teledetección espacial, técnicas forestales, internet, etc.) que permiten determinar aquellos procedimientos más eficaces desde el punto de vista de la calidad y fiabilidad de la información obtenida y del coste/beneficio; analizando, las mejoras que suponen frente a los métodos tradicionales. Para ello, se desarrollan algoritmos y métodos de análisis necesarios para extraer las variables e indicadores medioambientales con el fin de realizar la monitorización de los ciclos de carbono en ámbitos forestales atribuibles a proyectos de absorciones de CO2.El resultado es la creación de una plataforma web que permite la monitorización remota y en tiempo real de inventarios de carbono a través de la integración de datos provenientes de sistemas de sensorización, imágenes tratadas con tecnologÃas de observación de la tierra y datos de campo
Vortex ratchet reversal at fractional matching fields in kagom\'e-like array with symmetric pinning centers
Arrays of Ni nanodots embedded in Nb superconducting films have been
fabricated by sputtering and electron beam lithography techniques. The arrays
are periodic triangular lattices of circular Ni dots arranged in a
kagom\'e-like pattern with broken reflection symmetry. Relevant behaviors are
found in the vortex lattice dynamics : i) At values lower than the first
integer matching field, several fractional matching fields are present when the
vortex lattice moves parallel or perpendicular to the reflection symmetry axis
of the array showing a clear anisotropic character in the magnetoresistance
curves, ii) injecting an ac current perpendicular to the reflection symmetry
axis of the array yields an unidirectional motion of the vortex lattice
(ratchet effect) as a result of the interaction between the whole vortex
lattice and the asymmetric lattice of dots, iii) increasing the input current
amplitudes the ratchet effect changes polarity independently of matching field
values. These experimental results can be explained taking into account the
vortex lattice density.Comment: 9 pages, 4 figures, 1 tabl
Effect of Aging in the Perception of Health-Related Quality of Life in End-Stage Renal Disease Patients under Online-Hemodiafiltration
This work aimed to evaluate how aging could influence patients' perception of health quality of life (HRQOL), as well as, the effect of aging on dialysis adequacy and in hematological, iron status, inflammatory and nutritional markers. In this transversal study were enrolled 305 ESRD patients under online-hemodiafiltration (OL-HDF) (59.67% males; 64.9 ± 14.3 years old). Data about comorbidities, hematological data, iron status, dialysis adequacy, nutritional and inflammatory markers were collected from patient's records. Moreover, HRQOL score, by using the Kidney Disease Quality of Life-Short Form (KDQOL-SF), was assessed. Analyzing the results according to quartiles of age, significant differences were found for some parameters evaluated by the KDQOL-SF instrument, namely for work status, physical functioning and role-physical, which decreased with increasing age. We also found a higher proportion of diabetic patients, a decrease in creatinine, iron, albumin serum levels, transferrin saturation and nPCR, with increasing age. Moreover, significant negative correlations were found between age and mean cell hemoglobin concentration, iron, transferrin saturation, albumin, nPCR, work status, physical functioning and role-physical. In conclusion, our results showed that aging is associated with a decreased work status, physical functioning and role-physical, with a decreased dialysis adequacy, iron availability and nutritional status, and with an increased proportion of diabetic patients and of patients using central venous catheter, as the vascular access. The knowledge of these changes associated with aging, which have impact in the quality of life of the patients, could be useful in their management
Recommended from our members
First Detection of the Larval Chalkbrood Disease Pathogen Ascosphaera apis (Ascomycota: Eurotiomycetes: Ascosphaerales) in Adult Bumble Bees
Fungi in the genus Ascosphaera (Ascomycota: Eurotiomycetes: Ascosphaerales) cause chalkbrood disease in larvae of bees. Here, we report the first-ever detection of the fungus in adult bumble bees that were raised in captivity for studies on colony development. Wild queens of Bombus griseocollis, B. nevadensis and B. vosnesenskii were collected and maintained for establishment of nests. Queens that died during rearing or that did not lay eggs within one month of capture were dissected, and tissues were examined microscopically for the presence of pathogens. Filamentous fungi that were detected were plated on artificial media containing broad spectrum antibiotics for isolation and identification. Based on morphological characters, the fungus was identified as Ascosphaera apis (Maasen ex Claussen) Olive and Spiltoir, a species that has been reported earlier only from larvae of the European honey bee, Apis mellifera, the Asian honey bee, Apis cerana, and the carpenter bee Xylocopa californica arizonensis. The identity of the fungus was confirmed using molecular markers and phylogenetic analysis. Ascosphaera apis was detected in queens of all three bumble bee species examined. Of 150 queens dissected, 12 (8%) contained vegetative and reproductive stages of the fungus. Both fungal stages were also detected in two workers collected from colonies with Ascosphaera-infected B. nevadensis queens. In this study, wild bees could have been infected prior to capture for rearing, or, the A. apis infection could have originated via contaminated European honey bee pollen fed to the bumble bees in captivity. Thus, the discovery of A. apis in adult bumble bees in the current study has important implications for commercial production of bumble bee colonies and highlights potential risks to native bees via pathogen spillover from infected bees and infected pollen
Enhancement of synchronized vortex lattice motion in hybrid magnetic/amorphous superconducting nanostructures
Superconducting a-Mo_(3)Si and Nb films have been grown on arrays of Ni nanodots. We have studied the vortex lattice dynamics close to critical temperatures. Different vortex lattice configurations are obtained with the same array unit cell. These different vortex lattices occur at matching conditions between the vortex lattice and the array unit cell. The interplay between the random intrinsic pinning of the superconducting films and the periodic pinning of the array govern the vortex lattice configurations. Different vortex lattice configurations and enhancement of synchronized vortex lattice motion are obtained by increasing the periodic pinning strength and decreasing the random pinning strength
Directed motion of domain walls in biaxial ferromagnets under the influence of periodic external magnetic fields
Directed motion of domain walls (DWs) in a classical biaxial ferromagnet
placed under the influence of periodic unbiased external magnetic fields is
investigated. Using the symmetry approach developed in this article the
necessary conditions for the directed DW motion are found. This motion turns
out to be possible if the magnetic field is applied along the most easy axis.
The symmetry approach prohibits the directed DW motion if the magnetic field is
applied along any of the hard axes. With the help of the soliton perturbation
theory and numerical simulations, the average DW velocity as a function of
different system parameters such as damping constant, amplitude, and frequency
of the external field, is computed.Comment: Added references, corrected typos, extended introductio
Genetic diagnosis of pseudovaginal perineoscrotal hypospadias in an adolescent patient
El déficit enzimático de 5α-reductasa tipo 2 produce una forma de pseudohermafroditismo masculino en el cual un paciente de sexo cromosómico masculino (46XY) muestra genitales ambiguos al nacer, hipospadias y desarrollo de la masculinización en la pubertad. Presentamos un caso de una paciente adolescente con genitales externos femeninos y amenorrea primaria que consulta por sospecha de acromegalia. Se realiza un estudio hormonal, de imagen y genético que revela un déficit de 5-alfa-reductasa tipo 2, con la presencia de la variante c.271T>G (p.Tyr91Asp) en homocigosis. La tardanza en el diagnóstico supuso un retraso en la instauración de un régimen terapéutico adecuado, provocando una androgenización excesiva de la paciente con la consecuente afectación psicológica.5-alpha-reductase enzymatic deficit produces a form of pseudohermaphroditism in which a chromosomic male (46XY) shows ambiguous genitalia at birth, hypospadias and masculinization at puberty. We present a clinical case of a teenage patient with female external genitalia and primary amenorrhoea who was derived from her family doctor on suspicion of acromegaly. Hormonal, imaging and genetic research was conducted and it revealed a 5-alpha-reductase type 2, presenting the variant c.271T>G (p.Tyr91Asp) in homozygosity. A diagnosis delay suppossed a lag in appropiate therapeutic regime instauration, thus leading to an excessive androgenization of the patient with the corresponding psychological distress
- …