2,507 research outputs found
Homeownership as a Sign of Immigrants\u27 Consumer Acculturation: The Role of Region of Origin
One of the limitations highlighted by the consumer acculturation literature is the lack of empirical research to identify better constructs or indicators of consumer acculturation. In this article, the use of homeownership by immigrants in the host society is proposed as an indicator of advanced consumer acculturation. The decision to own a home by a minority group, such as immigrants, represents a key landmark in the process of adaptation to the new culture and a commitment with the host country\u27s values and culture. The empirical case used is the immigrant population of Spain. The sharp rise in its foreign-born population during the last decade and the significantly higher homeownership rates of natives in comparison with other countries makes the Spanish scenario a relevant case study. The results obtained show homeownership is linked to features associated with highly acculturated consumers. Moreover, the analysis conducted reveals important differences in the way immigrants from different origins advance in their consumer acculturation processes and suggest distinct approaches when marketing to these groups
S wave velocity structure below central Mexico using high-resolution surface wave tomography
Shear wave velocity of the crust below central Mexico is estimated using surface wave dispersion measurements from regional earthquakes recorded on a dense, 500 km long linear seismic network. Vertical components of regional records from 90 well-located earthquakes were used to compute Rayleigh-wave group-velocity dispersion curves. A tomographic inversion, with high resolution in a zone close to the array, obtained for periods between 5 and 50 s reveals significant differences relative to a reference model, especially at larger periods (>30 s). A 2-D S wave velocity model is obtained from the inversion of local dispersion curves that were reconstructed from the tomographic solutions. The results show large differences, especially in the lower crust, among back-arc, volcanic arc, and fore-arc regions; they also show a well-resolved low-velocity zone just below the active part of the Trans Mexican Volcanic Belt (TMVB) suggesting the presence of a mantle wedge. Low densities in the back arc, inferred from the low shear wave velocities, can provide isostatic support for the TMVB
Nivel de apropiación de la idea de discontinuidad de la materia en alumnos de Bachillerato. Implicaciones didácticas
Entropy and equilibrium state of free market models
Many recent models of trade dynamics use the simple idea of wealth exchanges
among economic agents in order to obtain a stable or equilibrium distribution
of wealth among the agents. In particular, a plain analogy compares the wealth
in a society with the energy in a physical system, and the trade between agents
to the energy exchange between molecules during collisions. In physical
systems, the energy exchange among molecules leads to a state of equipartition
of the energy and to an equilibrium situation where the entropy is a maximum.
On the other hand, in the majority of exchange models, the system converges to
a very unequal condensed state, where one or a few agents concentrate all the
wealth of the society while the wide majority of agents shares zero or almost
zero fraction of the wealth. So, in those economic systems a minimum entropy
state is attained. We propose here an analytical model where we investigate the
effects of a particular class of economic exchanges that minimize the entropy.
By solving the model we discuss the conditions that can drive the system to a
state of minimum entropy, as well as the mechanisms to recover a kind of
equipartition of wealth
Results of the 2004 Spanish Experimental Fishing in NAFO Subarea 1
An experimental fishing was carried out with three bottom trawlers commercial Spanish vessels from July to December
of the year 2004 in the Subarea 1. The main objective of the experimental fishing was to search for cephalopods species
concentrations inside the territorial waters of Greenland. During the experimental fishing a scientific observer stayed on
board each vessel to collect effort data, catches and yields by haul and Division. The observers carried out length
distribution samplings of the following species: Reinhardtius hippoglossoides, Pandalus borealis, Gadus morhua,
Sebastes spp., Hippoglossoides platessoides and Macrourus berglax. Biological samplings of R. hippoglossoides, P.
borealis, H. platessoides, G. morhua and M. berglax were also carried out. Otoliths of Greenland halibut (1 356) and
Atlantic cod (739) were collected for age determination. Greenland halibut was the main species caught and the
cephalopods, target species, have not been found in the experimental fishing
Photocatalytic activity in the in-flow degradation of NO on porous TiO2 –coated glasses from hybrid inorganic–organic thin films prepared by a combined ALD/MLD deposition strategy
A combined ALD/MLD (where ALD and MLD stand for atomic and molecular layer deposition, respectively) deposition strategy using TiCl4, H2 O and HQ (hydroquinone) as precursors has been applied for the preparation of inorganic–organic thin films on soda-lime glasses. The alternate deposition of TiO2 layers, by pulsing TiCl4 /H2 O (ALD), and hybrid layers, using TiCl4 /HQ (MLD), results in the formation of thin films that are precursors for porous TiO2-coatings after removal of the HQ template by annealing. The coated-glassed show good photocatalytic activity in the degradation of NO with up to 15% reduction of NO concentration in three successive photocatalytic cycles of 5 h each. Surface Scanning Electron Microscopy (SEM) images show that the TiO2-coating is composed of large grains that are made up of finer subgrains resulting in a porous structure with an average pore size of 3–4 nm. Transmission Electron Microscopy (TEM) images show two regions, a porous columnar structure on top and a denser region over the glass substrate. Energy Dispersive X-Ray (EDX) analysis, nanocrystal electron diffraction and Raman spectroscopy confirm the presence of the anatase phase, which, together with the porosity of the material, accounts for the observed photocatalytic activity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Magnetic Field scaling of Relaxation curves in Small Particle Systems
We study the effects of the magnetic field on the relaxation of the
magnetization of small monodomain non-interacting particles with random
orientations and distribution of anisotropy constants. Starting from a master
equation, we build up an expression for the time dependence of the
magnetization which takes into account thermal activation only over barriers
separating energy minima, which, in our model, can be computed exactly from
analytical expressions. Numerical calculations of the relaxation curves for
different distribution widths, and under different magnetic fields H and
temperatures T, have been performed. We show how a \svar scaling of the
curves, at different T and for a given H, can be carried out after proper
normalization of the data to the equilibrium magnetization. The resulting
master curves are shown to be closely related to what we call effective energy
barrier distributions, which, in our model, can be computed exactly from
analytical expressions. The concept of effective distribution serves us as a
basis for finding a scaling variable to scale relaxation curves at different H
and a given T, thus showing that the field dependence of energy barriers can be
also extracted from relaxation measurements.Comment: 12 pages, 9 figures, submitted to Phys. Rev.
Endometrial study in patients with postmenopausal metrorrhagia
Introduction: The aim of the study was to devise a strategy to diagnose malign endometrial pathologies (adenocarcinoma or atypical hyperplasia) that minimizes the number of invasive tests done (hysteroscopy, aspiration biopsy or curettage) with no loss of its detection efficiency. Material and methods: We retrospectively studied the clinical histories of 779 postmenopausal women at the University Hospital Complex of Albacete, for whom an endometrial study had been done (hysteroscopy, aspiration biopsy or curettage) with a 1-year follow-up between 1 March 2006 and 31 March 2008. Results: There were 77 cases of a malignant pathology (66 adenocarcinomas and 11 hyperplasias with atypia); 96.1% had metrorrhagia, and there were only 3 cases of asymptomatic patients (all 3 presented endometrial thickness of > 5 mm: 10, 12 and 15 mm). The sensitivity and specificity of the transvaginal ultrasound, with a 5 mm cut-off point to diagnose a malignant pathology, were 98.4% and 30.1%, respectively; 89.1% and 99.6%, respectively, for aspiration biopsy; 83.9% and 99.1%, respectively, for hysteroscopy without biopsy; and both were 100% for biopsy. Statistical significance was considered at p < 0.05 and confidence intervals were calculated at 95%. Conclusions: In postmenopausal women with metrorrhagia, the first action to take is to do a transvaginal ultrasound, followed by en endometrial study, but only if the endometrium is irregular or endometrial thickness is > 5 mm; in asymptomatic women, the cut-off point should be set at 10 mm. The immediate method of choice is an ambulatory biopsy
A Pathway From Porous Particle Technology Toward Tailoring Aerogels for Pulmonary Drug Administration
Pulmonary drug delivery has recognized benefits for both local and systemic treatments. Dry powder inhalers (DPIs) are convenient, portable and environmentally friendly devices, becoming an optimal choice for patients. The tailoring of novel formulations for DPIs, namely in the form of porous particles, is stimulating in the pharmaceutical research area to improve delivery efficiency. Suitable powder technological approaches are being sought to design such formulations. Namely, aerogel powders are nanostructured porous particles with particularly attractive properties (large surface area, excellent aerodynamic properties and high fluid uptake capacity) for these purposes. In this review, the most recent development on powder technologies used for the processing of particulate porous carriers are described via updated examples and critically discussed. A special focus will be devoted to the most recent advances and uses of aerogel technology to obtain porous particles with advanced performance in pulmonary delivery.Work carried out in the framework of COST Action CA18125 “Advanced Engineering and Research of aeroGels for Environment and Life Sciences” (AERoGELS), funded by the European Commission. This work was also supported by Xunta de Galicia [ED431C 2020/17], MCIUN [RTI2018-094131-AI00], Agencia Estatal de Investigación [AEI], and FEDER funds. CG-G acknowledges to MINECO for a Ramón y Cajal Fellowship [RYC2014-15239]
Neuroimagen del linfoma primario del sistema nervioso central en pacientes inmunodeprimidos
ResumenObjetivosEl linfoma primario del sistema nervioso central (LPSNC) es una entidad rara con un pronóstico fatal. Dado el aumento en el número de casos con inmunosupresión adquirida, nuestros objetivos son estudiar las características epidemiológicas y neurorradiológicas de aquellos pacientes inmunodeprimidos con diagnóstico de LPSNC con afectación cerebral e investigar si existen diferencias entre los pacientes con el virus de la inmunodeficiencia humana (VIH) positivo y negativo.Materiales y métodosSe realizó un estudio descriptivo y retrospectivo de los pacientes inmunodeprimidos con afectación cerebral por LPSNC, diagnosticados durante los últimos 13 años en 2 hospitales de referencia. Se evaluaron múltiples variables. El nivel de significación estadística utilizado fue p<0,05.ResultadosEl grupo VIH-positivo tenía una media de edad de 36,82±5,4 años, frente a los 55,60 ± 21,43 años de los pacientes VIH-negativo (p<0,022). Los pacientes VIH-positivo tuvieron una media de 1,27 ± 0,65 lesiones por paciente, mientras que en el grupo VIH-negativo fue de 2,60 ± 1,78 (p<0,039). El 18,2% (n=2) del grupo VIH-positivo y el 80% (n=8) del grupo VIH-negativo presentaron lesiones homogéneas (p<0,005). Ningún paciente VIH-positivo tuvo afectación del cuerpo calloso, pero el grupo VIH-negativo presentó un 50% (n=5) de afectación (p<0,012).ConclusionesEl LPSNC en pacientes inmunodeprimidos puede presentar múltiples características en las imágenes. Existen diferencias entre los pacientes VIH positivo y negativo, por lo que es importante reconocerlas para establecer un manejo y tratamiento diferente entre ambos grupos.AbstractPurposesPrimary central nervous system lymphoma (PCNSL) is a rare tumour with poor prognosis. Due to the increased number of patients with acquired immunodeficiency, our purposes are to describe epidemiological and imaging findings in immunodeficient patients with PCNSL of the brain and to study the differences between HIV-positive and HIV-negative patients with PCNSL.Materials and methodsA retrospective, descriptive study was performed with immunodeficient patients diagnosed of PCNSL of the brain during the last 13 years in two reference hospitals. Twenty-one patients fulfilled the inclusion criteria. Multiple variables were evaluated. Significance was defined as p<0.05.ResultsHIV-positive group was a mean age of 36,82±5,4 years and the mean age in HIV-negative group was 55,60±21,43 years (p<0,022). The mean number of lesions was 1,27±0,65 in HIV-positive group and 2,60±1,78 in HIV-negative group (p<0,039). The lesions were homogeneous in 18,2% (n=2) HIV-positive group and 80% (n=8) in HIV-negative group (p<0,005). No HIV-positive patient and 50% (n=5) of HIV-negative patients showed corpus callosum involvement (p<0,012).ConclusionsPCNSL in immunodeficient patients is associated with a large spectrum of radiological findings. There were differences between HIV-positive and HIV-negative patients, is important recognize these differences as the therapeutic management of these two groups vary
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