Transcripció de la clausura del Seminari EVALÚAMET

Transcripción de la intervención de Gabriel A. Palacio, Responsable de Aplicación de las Directrices Territoriales del Departamento de Territorio y Sostenibilidad de la Generalidad de Cataluña, en la clausura del Seminario de transferencia y difusión de EvalúaMET, modelo de evaluación de la eficiencia energética y ambiental, la movilidad y la estructura de usos del suelo para la Región Metropolitana de Barcelona, desarrollado en Barcelona el 21 de junio de 2012Transcripció de la intervenció de Gabriel A. Palacio, Responsable d'Aplicació de les Directrius Territorials del Departament de Territori i Sostenibilitat de la Generalitat de Catalunya, a la clausura del Seminari de transferència i difusió d'EVALÚAMET, model d'avaluació de l'eficiència energètica i ambiental, la mobilitat i l'estructura d'usos del sòl per la Regió Metropolitana de Barcelona, desenvolupat a Barcelona el 21 de juny de 2012.Peer Reviewe

Small Angle Scattering Of Large Protein Units Under Osmotic Stress

Indiana University-Purdue University Indianapolis (IUPUI)Large protein molecules are abundant in biological cells but are very difficult to study in physiological conditions due to molecular disorder. For large proteins, most structural information is obtained in crystalline states which can be achieved in certain conditions at very low temperature. X-ray and neutron crystallography methods can then be used for determination of crystalline structures at atomic level. However, in solution at room or physiological temperatures such highly resolved descriptions cannot be obtained except in very few cases. Scattering methods that can be used to study this type of structures at room temperature include small-angle x-ray and neutron scattering. These methods are used here to study two distinct proteins that are both classified as glycoproteins, which are a large class of proteins with diverse biological functions. In this study, two specific plasma glycoproteins were used: Fibrinogen (340 kDa) and Alpha 1-Antitrypsin or A1AT (52 kDa). These proteins have been chosen based on the fact that they have a propensity to form very large molecular aggregates due to their tendency to polymerize. One goal of this project is to show that for such complex structures, a combination of scattering methods that include SAXS, SANS, and DLS can address important structural and interaction questions despite the fact that atomic resolution cannot be obtained as in crystallography. A1AT protein has been shown to have protective roles of lung cells against emphysema, while fibrinogen is a major factor in the blood clotting process. A systematic approach to study these proteins interactions with lipid membranes and other proteins, using contrast-matching small-angle neutron scattering (SANS), small angle x-ray scattering (SAXS) and dynamic light scattering (DLS), is presented here. A series of structural reference points for each protein in solution were determined by performing measurements under osmotic stress controlled by the addition of polyethylene glycol-1,500 MW (PEG 1500) in the samples. Osmotic pressure changes the free energy of the molecular mixture and has consequences on the structure and the interaction of molecular aggregates. In particular, the measured radius of gyration (Rg) for A1AT shows a sharp structural transition when the concentration of PEG 1500 is between 33 wt% and 36 wt%. Similarly, a significant structural change was observed for fibrinogen when the concentration of PEG 1500 was above 40 wt%. This analysis is applied to a study of A1AT interacting with lipid membranes and to a study of fibrinogen polymerization in the presence of the enzyme thrombin, which catalyzes the formation of blood clots. The experimental approach presented here and the applications to specific questions show that an appropriate combination of scattering methods can produce useful information on the behavior and the interactions of large protein systems in physiological conditions despite the lower resolution compared to crystallography

The Career Development of Latina Women Achieving the Position of Public High School Principal

For this qualitative study, I used the lens of the Social Cognitive Career Theory to investigate the lived experiences of Latina women navigating their career paths into the roles of public high school principals. Latina women are underrepresented and in some states they are not represented at all. Few Latina women have secured the position of high school principal in public education; however for those who have, it is unclear how they attained the position. It was significant to learn about the factors that have lead to the representation of Latina women who serve as high school principals. The representation of Latina women high school principals is minimal and limited to states where there are high concentrations of the Latino student population. The U.S. Census reported that the increasing number of Latino students entering public high schools will continue to grow in the 21st century. The changing student body demographics in public schools with Latino students are also expanding to different parts of the United States. This qualitative investigation asked the central question: How do Latina women describe their lived experiences while navigating their career paths into public high school principalship? Participants were asked fourteen open-ended questions. Five major themes emerged from the interviews: (1) early influence (i.e. family and cultural traditions), (2) diverse career background (i.e. professional careers and opportunities into education profession), (3) high achieving teachers (i.e. initiatives and advancement), (4) professional leadership initiatives (i.e. data management, accomplishments, challenges, and support systems), (5) professional upward mobility (i.e. leadership style, supervisors opening doors to the principalship, aspirations beyond principalship). Through their experiences with family and cultural traditions, the Latina women principals developed an early influence foundation. The early influences meant having high expectations and aspirations for children\u27s education, which compelled the principals to ensure that students succeeded in the classroom. A second feature was a diverse career background. A diverse background meant having broad business perspectives, having specialized skills and knowing how to incorporate their talents to manage the implications of leadership in education. Findings from this study confirmed and added to past literature contributions

Halogen bonding stabilizes a cis-azobenzene derivative in the solid state: A crystallographic study

Crystals of trans- and cis-isomers of a fluorinated azobenzene derivative have been prepared and characterized by single-crystal X-ray diffraction. The presence of F atoms on the aromatic core of the azobenzene increases the lifetime of the metastable cis-isomer, allowing single crystals of the cis-azobenzene to be grown. Structural analysis on the cis-azobenzene, complemented with density functional theory calculations, highlights the active role of the halogen-bond contact (N...I synthon) in promoting the stabilization of the cis-isomer. The presence of a long aliphatic chain on the azobenzene unit induces a phase segregation that stabilizes the molecular arrangement for both the trans- and cis-isomers. Due to the rarity of cis-azobenzene crystal structures in the literature, our paper makes a step towards understanding the role of non-covalent interactions in driving the packing of metastable azobenzene isomers. This is expected to be important in the future rational design of solid-state, photoresponsive materials based on halogen bonding. We show by single-crystal X-ray diffraction studies and computational analysis that halogen bonding can stabilize a metastable cis-azobenzene derivative in the solid state

Sistema de deshidratación con doble cámara de secado y nivel de camas contenedoras automático

En este proyecto a socializar, se desarrolló un sistema de deshidratación solar aplicado a plantas aromáticas y medicinales, el cual consta de dos cámaras, una de precalentamiento y otra de secado que permite alcanzar temperaturas máximas cercanas a los 60°C en niveles pico de radiación solar. En la parte superior de la cámara interna se incluye un sistema de extracción para intercambiar los niveles térmicos y de humedad con la cámara interna. Para adecuar el material vegetal al nivel térmico recomendado para las plantas a deshidratar, se construyó un sistema de nivel de camas contenedoras de material vegetal automático, que ajusta el valor de la temperatura de acuerdo a los niveles máximos y mínimos alcanzados internamente y gracias al soporte de un motor lineal. Se alcanza una disminución del tiempo de secado del 25% con respecto a una marquesina tradicional para la planta experimentada.In this project to socialize, was developed a solar dehydration system applied to aromatic and medicinal plants, which consists of two chambers, one of preheating and one of drying that allows achieving maximum temperatures close to 60 ° C at peak levels of solar radiation. At top of the inner chamber is an extraction system for exchanging thermal and humidity levels with the internal chamber. To adapt the plant material to the recommended thermal level for the plants to be dehydrated, was constructed a system of bed level containing automatic plant material, which adjusts the temperature according to the maximum and minimum levels reached internally and thanks to support of a linear motor. A reduction of drying time of 25% compared to a traditional canopy for the experienced plant is achieved.Fil: Palacio, José A.. Institución Universitaria Pascual Bravo. Colombia.Fil: Cadavid, Bayardo. Institución Universitaria Pascual Bravo. Colombia

Thermoelectric power quantum oscillations in the ferromagnet UGe2_2

We present thermoelectric power and resistivity measurements in the ferromagnet UGe$_2$ as a function of temperature and magnetic field. At low temperature, huge quantum oscillations are observed in the thermoelectric power as a function of the magnetic field applied along the $a$ axis. The frequencies of the extreme orbits are determined and an analysis of the cyclotron masses is performed following different theoretical approaches for quantum oscillations detected in the thermoelectric power. They are compared to those obtained by Shubnikov-de Haas experiments on the same crystal and previous de Haas-van Alphen experiments. The agreement of the different probes confirms thermoelectric power as an excellent probe to extract simultaneously both microscopic and macroscopic information on the Fermi-surface properties. Band-structure calculations of UGe$_2$ in the ferromagnetic state are compared to the experiment.Comment: 10 figures, 12 pages, accepted for publication in Phys. Rev.