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Alcala de Henares, Spain

The University of Alcalá is a public university located in Alcalá de Henares, a city 35 km northeast of Madrid in Spain and also the third-largest city of the region. Founded in 1977, the University of Alcalá is especially renowned in the Spanish-speaking world for its annual presentation of the highly prestigious Cervantes Prize.The University currently enrolls 28,336 students, 17,252 of whom are studying undergraduate degrees which are taught by a teaching staff of 2,608 professors, lecturers and researchers belonging to 24 departments. The University is also proud of its modern and efficient administration, which is carried out by the Administration and Services, comprising approximately 800 people. Wikipedia.

Do the circulating levels of a panel of adipokines involved in glucose metabolism exhibit sexual dimorphism in the fasting state and after an oral glucose load? Our results indicate sexual dimorphism in the circulating concentrations of adipokines involved in intermediate metabolism in the fasting state and during an oral glucose load. This finding suggests an influence of sex steroids on adipose tissue function. Sexual dimorphism in adipose tissue distribution fully develops after puberty and modulates the risk for cardiometabolic disorders. However, the possibility that adipose tissue function exhibits sexual dimorphism as well as its distribution is unproved. Cross-sectional case-control study including 32 subjects. Sixteen subjects with weight excess (8 men and 8 women, including 4 overweight and 4 obese subjects in each group) and 16 normal weight healthy volunteers (8 men and 8 women) presenting with similar age were submitted to a 75-g oral glucose tolerance test (oGTT). We measured circulating concentrations of insulin, glucose, chemerin, lipocalin-2, omentin-1, leptin and adiponectin and calculated their areas under the oGTT curve (AUC). Leptin and adiponectin concentrations were higher throughout the oGTT in women compared with men. Lipocalin-2 concentrations decreased during the oGTT in the whole group of study subjects. However, these levels remained higher in men with weight excess compared with normal weight men, whereas in women with weight excess lipocalin-2 levels at the end of the oGTT were lower compared with normal weight women. Sex was among the main determinants of the AUC of omentin-1 and leptin in linear regression models, and lower estradiol and testosterone concentrations were related to higher AUC of chemerin and omentin-1, respectively. Subjects with weight excess had higher AUC of chemerin and leptin and lower AUC of omentin-1 and adiponectin levels, independently of sex. We included a relatively small sample size and, because this was a cross-sectional study, we cannot infer causality to the associations between the changes in circulating adipokine concentrations and the variables studied here. Sexual dimorphism in adipose tissue function should be considered when studying adiposity and obesity, and also when designing strategies for their diagnosis and management.

Escarpa A.,University of Alcala
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2014

These insights attempt to share with the community the lights and shadows of one emerging and exciting topic, Food Microfluidics, defined as microfluidic technology for food analysis and diagnosis in important areas such as food safety and quality. The reader is invited to question non-easy interrogations such as why Food Microfluidics, what is the next step and what could we do with the available technology. This article invites food analysts to be seduced by this technology and then to take an interesting trip departing from the main gained achievements, having a look at the crossing bridges over Food Microfluidic challenges or having a look at available technology to start. Finally, this trip arrives at a privileged place to gaze the horizons. A wonderful landscape-full of inspiration-for Food Microfluidics is anticipated. These insights have also been written wishing to give improved conceptual and realistic solutions for food analysis, with the additional hope to attract the community with exciting technology, in order to get novel and unexpected achievements in this field. © 2014 the Partner Organisations.

Escarpa A.,University of Alcala
Chemical Record | Year: 2012

With the appearance of advanced approaches such as screen-printed technology, biosensors, microchips and nanotechnology, among others, electroanalysis is undergoing a true Renaissance. Inherent miniaturization of electrochemistry makes it a unique detection and transduction principle, highly compatible with the modern miniaturized analytical chemistry involving micro- and nanotechnologies. It also implies advantages on portability and further disposability. Another very unique feature linked to electrochemistry is the versatility for "selectivity design" towards the suitable selection of (nano)(bio)materials and by the direct manipulation of the electrical properties. Their remarkable sensitivity and low cost are additional valuable features. However, from my personal perspective, these "natural beauties" are underexploited in the analysis of food samples not only because of the complexity of food samples but also because electrochemistry has traditionally been seen as "a difficult thing". From my own experience, electrochemical approaches have been very useful in the evaluation of antioxidant activities in vitro, in the development of screening methods, as high-performance detectors in advanced analytical microsystems such as capillary-electrophoresis microchips and in the development of microfluidic inmunosensors. In consequence, electroanalysis has also demonstrated an important role in fields such as antioxidant sensing, quality control assessment, detection of frauds and food safety. In this personal account, drawing from selected examples of my own work, I illustrate the marriage between electrochemistry and food analysis, food electroanalysis, by sense and simplicity. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Alvarez-Perez J.L.,University of Alcala
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011

The Cloude-Pottier radar polarimetry paradigm, which is understood as the spectral decomposition theorem of the target coherency matrix plus the classification technique based on the triad of parameters given by entropy, alpha angle, and anisotropy, has become a very well-established methodology for treating high-resolution polarimetric radar images, particularly those obtained with synthetic aperture radar (SAR) sensors. This methodology is revisited here from the standpoint of the coherence and polarization theory and their mutual relationship, in the light of the interest aroused once again after Wolf's article on this subject in 2003. Despite its success in terms of acceptance by the SAR community, the CloudePottier paradigm relies on the arguable assumption that different scattering mechanisms can be separated by diagonalizing the aforementioned coherency matrix and then assigning each corresponding eigenvector to one of the independent scattering mechanisms. Our main statement in this paper is that the coherency matrix illustrates the behavior of the target from the point of view of polarization and not of full coherence, which would justify this assumption, even if only partially. Therefore, it is not rigorous to identify each eigenvector of this decomposition with a distinct scattering mechanism. Cloude and Pottier argue that the eigendecomposition of the coherency matrix outperforms other target decomposition theorems due to its uniqueness. It is also suggested that this very uniqueness, together with the orthogonality of the eigenvectors, supports the injective mapping between scattering mechanisms and eigenvectors that was first assumed based on statistical independence. With the aim of providing a comprehensive overview of the problem, we discuss some important concepts with regard to both field and target coherency matrices. In addition, we revise the concepts of entropy, alpha angle, and anisotropy as defined by the aforementioned authors, which are also a central part of this paradigm and which have played an important role in SAR image classification since its introduction. Again, some disagreement is found with the meaning of these parameters as they have been discussed so far. © 2006 IEEE.

Barluenga G.,University of Alcala
Cement and Concrete Research | Year: 2010

The inclusion of small amounts of short fibers has demonstrated to be an effective solution to control cracking due to drying shrinkage of concretes at early ages. The key point of fiber effectiveness is their capacity to sew the crack sides, preventing crack opening, because cracking of concrete matrix induces fiber actuation. In this paper, fiber-matrix interaction is analyzed considering different amounts (from 600 to 1200 g/m3) and lengths (6, 12 and 18 mm) of alkali-resistant (AR) glass fibers and fiber coating effect. The combination of experimental results previously published and analyses with simple FE models allows for better understanding of early age concrete behavior. As concrete mechanical capacity develops with age, while fibers have full properties before being included in concrete matrix, the interphase between matrix and fibers evolves during setting and hardening, and affects cracking control effectiveness, due to stresses induced by fibers into the matrix during concrete hydration. © 2009 Elsevier Ltd. All rights reserved.

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