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Mar del Plata, Argentina

The National University of La Plata is one of the most important Argentine national universities and the biggest one situated in the city of La Plata, capital of Buenos Aires Province. It has over 90,000 regular students, 10,000 teaching staff, 16 departments and 106 available degrees.UNLP comprises the Rafael Hernández National College, the Victor Mercante Lyceum, the Bachelor of Fine Arts program, the School of Agronomy, the La Plata University Radio, the La Plata University Press and numerous academic centers for research and outreach including La Plata Museum of Natural science, the University Public Library, the Samay Huasi Retreat for Artists and Writers, the Institute of Physical Education, the Astronomical Observatory and the Santa Catalina Rural Association.The institution began operations on April 18, 1897, as the Universidad Provincial de La Plata with Dr. Dardo Rocha as its rector. In 1905, Joaquín V. González, the Minister of Justice and Public Education of the government of Manuel Quintana, decided to nationalize it. González also integrated many municipal scientific institutions into the university, and a year later he became the first President of the National University of La Plata. Today the university holds one of the most important paleontological and anthropological collections in South America. Wikipedia.

Catala A.,National University of La Plata
Frontiers in Bioscience - Scholar | Year: 2011

Retina is very rich in membranes containing polyunsaturated fatty acids. Reactive oxygen species initiates chain reactions of lipid peroxidation which injure the retina, especially the membranes that play important roles in visual function. Furthermore, biomolecules such as proteins or amino lipids can be covalently modified by lipid decomposition products. In retinal membranes, peroxidation of lipids is also usually accompanied by oxidation of membrane proteins. In consequence, lipid peroxidation may alter the arrangement of proteins in bilayers and by that interfere with their physiological role on the membrane function. Here, we review several studies on the lipid peroxidation of membrane phospholipids in retina. Particular emphasis is placed on the molecular changes of very long chain polyunsaturated fatty acids associated with protein modifications during peroxidation of photoreceptor membranes. Furthermore we use liposomes to analyze peroxidation of retinal lipids. Conjugated dienes formed from oxidized PUFAs, and TBARS products derived from the breakdown of these fatty acids located in phospholipids can be analyzed during lipid peroxidation of liposomes made of retinal lipids using Fe2+ and Fe3+ as initiators.

Balart L.,National University of La Plata
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

We study the Brown-York quasilocal energy for regular black holes. We also express the identity that relates the difference of the Brown-York quasilocal energy and the Komar charge at the horizon to the total energy of the spacetime for static and spherically symmetric black hole solutions in a convenient way which permits us to understand why this identity is not satisfied when we consider nonlinear electrodynamics. However, we give a relation between quantities evaluated at the horizon and at infinity when nonlinear electrodynamics is considered. Similar relations are obtained for more general static and spherically symmetric black hole solutions which include solutions of dilaton gravity theories. © 2010 Elsevier B.V. All rights reserved.

Ibanez F.J.,National University of La Plata | Zamborini F.P.,University of Louisville
Small | Year: 2012

This review describes the use of chemically modified pure and alloyed metal nanoparticles for chemiresistive sensing applications. Chemically modified metal nanoparticles consist of a pure or alloyed metallic core with some type of chemical coating. Researchers have studied the electronic properties of 1D, 2D, and 3D assemblies of chemically modified metal nanoparticles, and even single individual nanoparticles. The interaction with the analyte alters the conductivity of the sensitive material, providing a signal to measure the analyte concentration. This review focuses on chemiresistive sensing of a wide variety of gas- and liquid-phase analytes with metal nanoparticles coated with organothiols, ions, polymers, surfactants, and biomolecules. Different strategies used to incorporate chemically modified nanoparticles into chemiresistive sensing devices are reviewed, focusing on the different types of metal and alloy compositions, coatings, methods of assembly, and analytes (vapors, gases, liquids, biological materials), along with other important factors. A material that changes resistance in the presence of gas and liquid analytes is termed a chemiresistor. A chemiresistive film of various dimensions comprises organic-modified nanoparticles where electron hopping occurs when a voltage (V) is applied. The current of the film changes over time in the presence of analytes in the gas- or liquid-phase (blue dots). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The "Fluid Mosaic Model", described by Singer and Nicolson, explain both how a cell membrane preserves a critical barrier function while it concomitantly facilitates rapid lateral diffusion of proteins and lipids within the planar membrane surface. However, the lipid components of biological plasma membranes are not regularly distributed. They are thought to contain "rafts" - nano-domains enriched in sphingolipids and cholesterol that are distinct from surrounding membranes of unsaturated phospholipids. Cholesterol and fatty acids adjust the transport and diffusion of molecular oxygen in membranes. The presence of cholesterol and saturated phospholipids decreases oxygen permeability across the membrane. Alpha-tocopherol, the main antioxidant in biological membranes, partition into domains that are enriched in polyunsaturated phospholipids increasing the concentration of the vitamin in the place where it is most required. On the basis of these observations, it is possible to assume that non-raft domains enriched in phospholipids containing PUFAs and vitamin E will be more accessible by molecular oxygen than lipid raft domains enriched in sphingolipids and cholesterol. This situation will render some nano-domains more sensitive to lipid peroxidation than others. Phospholipid oxidation products are very likely to alter the properties of biological membranes, because their polarity and shape may differ considerably from the structures of their parent molecules. Addition of a polar oxygen atom to several peroxidized fatty acids reorients the acyl chain whereby it no longer remains buried within the membrane interior, but rather projects into the aqueous environment "Lipid Whisker Model". This exceptional conformational change facilitates direct physical access of the oxidized fatty acid moiety to cell surface scavenger receptors. © 2011 Elsevier Masson SAS. All rights reserved.

Rossi G.,National University of La Plata
IEEE Internet Computing | Year: 2013

The Object Management Group has adopted a new standard for interactive applications development, the Interaction Flow Modeling Language (IFML). The author briefly analyzes this new standard's importance and its relationship with other Web modeling approaches. © 1997-2012 IEEE.

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