Robustness and Closeness Centrality for Self-Organized and Planned Cities

Street networks are important infrastructural transportation systems that cover a great part of the planet. It is now widely accepted that transportation properties of street networks are better understood in the interplay between the street network itself and the so called \textit{information} or \textit{dual network}, which embeds the topology of the street network navigation system. In this work, we present a novel robustness analysis, based on the interaction between the primal and the dual transportation layer for two large metropolis, London and Chicago, thus considering the structural differences to intentional attacks for \textit{self-organized} and planned cities. We elaborate the results through an accurate closeness centrality analysis in the Euclidean space and in the relationship between primal and dual space. Interestingly enough, we find that even if the considered planar graphs display very distinct properties, the information space induce them to converge toward systems which are similar in terms of transportation properties

Microscopic mechanism of water diffusion in glucose glasses

The preservation of biomaterials depends critically on the mobility of water in the glassy state, manifested as a secondary beta relaxation and diffusion. We use coarse grain simulations to elucidate the molecular mechanism underlying the relaxations for water-glucose glass, finding two pathways for water diffusion: (i) water jumps into neighbor water positions (linking to water structure), and (ii) water jumps into glucose positions (coupling to glucose rotation). This work suggests strategies for enhancing preservation by stiffening the segmental motions of the carbohydrates

M3B: A Coarse Grain Force Field for Molecular Simulations of Malto-Oligosaccharides and Their Water Mixtures

We derive a chemically realistic coarse grain model and force field for the simulation of malto-oligosaccharides (α(1→4) d-glucans) and their aqueous mixtures. This coarse grain model for carbohydrates (denoted M3B) represents each glucose monomer by three beads while describing the water molecule as a single particle. M3B includes no charges or hydrogen-bonding terms, using only two-body Morse functions to describe long-range forces. The configurations obtained with the M3B model map uniquely and quickly back to a full atomistic description. M3B was parametrized to fit the results from atomistic simulations for the gas phase and amorphous bulk phase of sugars over a wide range of pressures. In particular, we required that the M3B force field provide an accurate representation of such quantities as excluded volume interactions and the distribution of torsional configurations about the intermonomer bonds. We find that M3B leads to a helical structure for polysaccharide chains and predicts left-handed helices to be more stable than right-handed ones, in agreement with the experiments. We find that parallel and antiparallel double-helical bulk structures of malto-oligosaccharides are feasible and of similar energy. The M3B model leads to a glass transition temperature (T_g) for glucose of 296 K in good agreement with experiment (304 K) and a T_g for 12 wt % water−glucose mixtures of 239 K in good agreement with experiment (240 K). These results suggest that these characteristic physical properties of carbohydrates can be described well without the use of explicit hydrogen bonds or electrostatics and also without introducing explicit directional forces in the nonbonded interactions. Molecular dynamics (MD) simulations with M3B are ∼7000 times faster than fully flexible atomistic simulations, making it practical to study large systems for long times. We expect that M3B will be of use for the study of the structure and dynamics of complex syrups and supercooled carbohydrates solutions

Calcium Hydroxide for treatment Industry effluents lemon essential oil

El agua en el Perú se encuentra protegida por leyes que evitan su uso indebido y contaminación. La costa norte del Perú alberga industrias dedicadas a la extracción de aceite esencial de limón, los principales problemas que se presentan es el vertimiento de efluentes a los cuerpos de agua con niveles de acidez y temperatura que exceden los límites permisibles para uso humano y conservación ambiental. Esto evidencia la presencia de grandes pozas de almacenamiento desde donde se infiltra el efluente al subsuelo, los cursos de agua, además de la generación de malos olores por su elevada DQO – DBO y efectos sobre la fauna y flora circundante. El tratamiento de estos efluentes utilizando hidróxido cálcico permite de forma efectiva alcanzar niveles adecuados de pH y disminuir la carga orgánica de los mismos con beneficios añadidos para la reutilización de subproductos resultantes de precipitación de sólidos durante el tratamiento.ABSTRACT: Water in Peru is protected by laws that prevent their abuse and pollution. The north coast of Peru is home to industries engaged in the extraction of essential oil of lemon, the main problems encountered are the dumping of effluent into bodies of water with acidity and temperature levels that exceed the permissible limits for humanand environmental conservation . This evidences the presence of large storage pools where the effluent infiltrates into the ground, water courses, plus odor generation by high DQO - DBO and effects on surrounding wildlife. The effluent treatment using calcium hydroxide can effectively achieve adequate levels of pH and reduce the organic load of the same with added benefits to reuse products resulting from precipitation of solids during the treatment

Building a morphological and syntactic lexicon by merging various linguistic resources

Proceedings of the 17th Nordic Conference of Computational Linguistics NODALIDA 2009. Editors: Kristiina Jokinen and Eckhard Bick. NEALT Proceedings Series, Vol. 4 (2009), 126-133. © 2009 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/9206

Antimicrobial susceptibility testing in biofilm-growing bacteria

AbstractBiofilms are organized bacterial communities embedded in an extracellular polymeric matrix attached to living or abiotic surfaces. The development of biofilms is currently recognized as one of the most relevant drivers of persistent infections. Among them, chronic respiratory infection by Pseudomonas aeruginosa in cystic fibrosis patients is probably the most intensively studied. The lack of correlation between conventional susceptibility test results and therapeutic success in chronic infections is probably a consequence of the use of planktonically growing instead of biofilm-growing bacteria. Therefore, several in vitro models to evaluate antimicrobial activity on biofilms have been implemented over the last decade. Microtitre plate-based assays, the Calgary device, substratum suspending reactors and the flow cell system are some of the most used in vitro biofilm models for susceptibility studies. Likewise, new pharmacodynamic parameters, including minimal biofilm inhibitory concentration, minimal biofilm-eradication concentration, biofilm bactericidal concentration, and biofilm-prevention concentration, have been defined in recent years to quantify antibiotic activity in biofilms. Using these parameters, several studies have shown very significant quantitative and qualitative differences for the effects of most antibiotics when acting on planktonic or biofilm bacteria. Nevertheless, standardization of the procedures, parameters and breakpoints, by official agencies, is needed before they are implemented in clinical microbiology laboratories for routine susceptibility testing. Research efforts should also be directed to obtaining a deeper understanding of biofilm resistance mechanisms, the evaluation of optimal pharmacokinetic/pharmacodynamic models for biofilm growth, and correlation with clinical outcome

Fluorinated Imidazoles as Proton Carriers for Water-Free Fuel Cell Membranes

We propose an alternative new material (2,4,5-trifluoroimidazole impregnated Nafion) for use as a high-temperature, water-free membrane for proton-exchange membrane fuel cells. This material has been tested computationally using molecular dynamics and quantum mechanics techniques, leading to an estimated conductivity of ∼0.06 S/cm at 177 °C. This material overcomes the weakness of the imidazole-impregnated membranes, i.e., the poisoning of the Pt electrode. We find that 2,4,5-trifluoroimidazole binds weakly to platinum surfaces, so poisoning is not expected

Obesidad, nutrición y actividad física

La cantidad y calidad de actividad física se ha reducido considerablemente en la sociedad actual. El desequilibrio que se produce cuando el consumo de alimentos supera el gasto energético conlleva un aumento de peso corporal y consecuentemente de la obesidad. Varios son los factores determinantes de la obesidad, así como sus consecuencias. Para tratar una persona obesa es necesario conocer, en primer lugar, el agente desencadenante de la enfermedad. Los profesores de Educación Física, junto con las aportaciones de los profesionales de otras áreas de las ciencias del deporte, pueden ser de vital importancia para ayudar a los niños, niñas y adolescentes con problemas causados por el exceso de peso corporal