211 research outputs found
Situación de las poblaciones valencianas del género Marsilea: medidas para su conservación.
ESTRELLES, E., IBARS, A. M. & HERRERO-BORGOÑÓN, J. J. 2001. Situación de las poblaciones valencianas del género Marsilea: medidas para su conservación. Bot. Complutensis 25: 241-249. Se analiza la situación de las poblaciones valencianas de Marsilea batardae, M. quadrifolia y M. strigosa, así como las amenazas que actualmente pesan sobre ellas. Asimismo se comentan las medidas que se han puesto en marcha para asegurar su conservación, entre las que destacan las introducciones experimentales.ESTRELLES, E., IBARS, A. M. & HERRERO-BORGOÑÓN, J. J. 2001. Situation of the Valencian populations of Marsilea: strategies for its conservation. Bot. Complutensis 25: 241-249. The situation of Valencian populations of Marsilea batardae, M. quadrifolia and M. strigosa, as well as the threats that they suffer at present are analysed here. Likewise the measures applied to ensure their conservation, with emphasis on the experimental introductions, are commented
Influence of aspect ratio in convection due to non-uniform heating
The influence of fluid depth in a convection problem in which heating is nonuniform is studied. We consider
a vessel that has at the bottom a temperature distribution which has Gaussian shape in the transversal direction
and whose surface is open to the atmosphere. Coupled buoyancy and thermocapillary effects are taken into
account. The results confirm a stationary bifurcation and a prelude of an oscillatory one as has been observed
recently in convection with quasi-one-dimensional heaters
Bifurcations in a convection problem with temperature-dependent viscosity
A convection problem with temperature-dependent viscosity in an infinite
layer is presented. As described, this problem has important applications in
mantle convection. The existence of a stationary bifurcation is proved together
with a condition to obtain the critical parameters at which the bifurcation
takes place. For a general dependence of viscosity with temperature a numerical
strategy for the calculation of the critical bifurcation curves and the most
unstable modes has been developed. For a exponential dependence of viscosity on
temperature the numerical calculations have been done. Comparisons with the
classical Rayleigh-B\'enard problem with constant viscosity indicate that the
critical threshold decreases as the exponential rate parameter increases.Comment: 16 pages, 5 figure
Primary instabilities in convective cells due to non-uniform heating
We study a convection problem in a container with a surface open to the air and heated by a long wire placed
at the bottom. Coupled buoyancy and thermocapillarity effects are taken into account. A basic convective state
appears as soon as a temperature gradient with horizontal component different from zero is applied. It consists
of two big rolls that fill the convective cell and are parallel to the heater. A numerical solution allows us to
determine this basic state. A linear stability analysis on this solution is carried out. For different values of the
applied temperature gradient the basic rolls undergo a stationary bifurcation. The thresholds depend on the
fluid properties, on the geometry of the heater, and on the heat exchange on the free surface. This confirms the
results obtained in recent experiments
Occurrence and exposure of 3-monochloropropanediol diesters in edible oils and oil-based foodstuffs from the Spanish market
During the industrial refining process of edible oils and the manufacture of oil-based foodstuff, contaminants such as 3-monochloropropanediol (3-MCPD) fatty acid diesters can be produced. One hundred samples of different edible oils and related fatty food purchased from local Spanish markets were analyzed to evaluate the occurrence of these contaminants. Data of seven 3-MCPD diesters together with corresponding total 3-MCPD equivalents are presented. The procedure is based on a modified QuEChERS protocol followed by LC-MS/MS analysis. Extra virgin olive oil (EVOO) and unrefined oils did not contain detectable levels of the target analytes. The highest levels of 3-MCPD diesters were found in palm oils, for 1,2-Dilinoleoyl-3-chloropropanediol (LILI) and 1–2-Bispalmitoyl-3-chloropropanediol (PAPA) with concentrations close to 10 mg kg−1 and in the lipid fraction of margarines (8.09, 3.77 and 3.72 mg kg−1 for LILI, PAPA and 1-Oleoyl-2-linoleoyl-3-chloropropanediol (OLLI), respectively).Spanish Ministry of Science and Innovation (Project AGL-2014-53647-R) and FEDER fund
An Operational System For Monitoring Oil Spills In The Mediterranean Sea: The PROMED System
The primary objective of this work was the development of an operational system for early detection of oil-spills, monitoring of their evolution, and provision of support to responsible Public Authorities during cleanup operations, based on Remote Sensing and GIS technologies. In case of emergency, the principal characteristics of the oil spill are defined with the aid of a space-borne synthetic aperture radar (SAR). The transport, spreading and dispersion of the oil spill is subsequently simulated on the basis of wind forecasts of the area. The use of thematic maps of protected, fishing and urban areas, and regions of high tourism allows the better assessment of the impact of an oil spill on the areas to be affected in terms of environmental sensitivity. Finally, reports are generated notifying port authorities, the media, and local organizations to be potentially affected by the presence of the oil spill. The pilot site for testing the PROMED System in Greece is the island of Crete
Effect of annealing in the Sb and In distribution of type II GaAsSb-capped InAs quantum dots
Type II emission optoelectronic devices using GaAsSb strain reduction layers (SRL) over InAs quantum dots (QDs) have aroused great interest. Recent studies have demonstrated an extraordinary increase in photoluminescence (PL) intensity maintaining type II emission after a rapid thermal anneal (RTA), but with an undesirable blueshift. In this work, we have characterized the effect of RTA on InAs/GaAs QDs embedded in a SRL of GaAsSb by transmission electron microscopy (TEM) and finite element simulations. We find that annealing alters both the distribution of Sb in the SRL as well as the exchange of cations (In and Ga) between the QDs and the SRL. First, annealing causes modifications in the capping layer, reducing its thickness but maintaining the maximum Sb content and improving its homogeneity. In addition, the formation of Sb-rich clusters with loop dislocations is noticed, which seems not to be an impediment for an increased PL intensity. Second, RTA produces flatter QDs with larger base diameter and induces a more homogeneous QD height distribution. The Sb is accumulated over the QDs and the RTA enlarges the Sb-rich region, but the Sb contents are very similar. This fact leaves the type II alignment without major changes. Atomic-scale strain analysis of the nanostructures reveal a strong intermixing of In/Ga between the QDs and the capping layer, which is the main responsible mechanism of the PL blueshift. The improvement of the crystalline quality of the capping layer together with higher homogeneity QD sizes could be the origin of the enhancement of the PL emission
Psychosocial burden in adult patients with atopic dermatitis
P16
Objective: Atopic dermatitis affects patients’ quality of life (QoL) in many ways. It is important to analyze the impact that the disease produces in order to better define the healthcare needs of adult patients with atopic dermatitis.
Patients and Methods: 14 adult patients with atopic dermatitis were interviewed. The qualitative interviews were semi-structured and supported by a simple script, which allowed a complete and flexible interview.
Results: Six affected areas of the patient’s life with atopic dermatitis were identified: economic, work-related, personal, psychosocial, clinical and relational. It is emphasized that atopic dermatitis has a great psychosocial impact on the adult patient, since it alters interpersonal relationships, generates rejection, stigmatization and social isolation, limits the patient in various areas and activities of their daily life or alters sleep, among others. The visible aspect, the itching-scratching cycle, the lack of awareness and ignorance of the disease, the lack of a definitive solution among the treatments and the side effects of some of them are of great concern.
Conclusions: The QoL of the patients with atopic dermatitis is negatively affected and a holistic multidisciplinary intervention is necessary in order to mitigate the negative impact of the disease
Quality of life in hidradenitis suppurativa: psychometric properties of HSQOL-24
P14
Introduction: Hidradenitis Suppurativa (HS) has been associated with impaired quality of life (QoL). There are various measuring systems to assess physical severity; however, there are no specific QoL questionnaires for this disease in the Spanish language.
Objective: To develop and validate a disease-specific instrument to measure QoL in patients with HS.
Methods: A literature search was carried out to prepare a semi structured interview for patients with HS, as well as a Delphi expert consensus among health professionals. The validation with a sample of 130 patients is presented. The preliminary validation of the HSQoL-24 was passed twice to a group of 30 patients with 30 ± 10 days of interval. The DLQI and the Skindex-29 were used for its validation.
Results: Cronbach alpha 0.87 indicates a good internal consistency of the questionnaire. The intraclass correlation coefficient (ICC) with the DLQI was 0.70 (p-value) (< 0.001), and 0.87 (p-value) (< 0.001) with the Skindex-29.
Conclusions: The HSQoL-24 is the first specific self-administered questionnaire to assess QoL in patients with HS in Spanish. It is user friendly and easy to. This study demonstrates the excellent properties of the instrument: comprehensibility, reliability (test-retest), internal consistency, validity, comparison with DLQI and SKINDEX-29, and discriminative capacity
Spectral numerical schemes for time-dependent convection with viscosity dependent on temperature
This article proposes spectral numerical methods to solve the time evolution
of convection problems with viscosity strongly depending on temperature at
infinite Prandtl number. Although we verify the proposed techniques just for
viscosities that depend exponentially on temperature, the methods are
extensible to other dependence laws. The set-up is a 2D domain with periodic
boundary conditions along the horizontal coordinate. This introduces a symmetry
in the problem, the O(2) symmetry, which is particularly well described by
spectral methods and motivates the use of these methods in this context. We
examine the scope of our techniques by exploring transitions from stationary
regimes towards time dependent regimes. At a given aspect ratio stable
stationary solutions become unstable through a Hopf bifurcation, after which
the time-dependent regime is solved by the spectral techniques proposed in this
article.Comment: 17 pages, 7 figure
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