Characterization of anionic reverse micelles formulated on biobased solvents as replacing conventional nonpolar organic solvents

Two reverse micelles (RMs) employing 1,4-bis-2-ethylhexylsulfosuccinate (AOT) and two biobased solvents, p-cymene (p-cym) or limonene (lim), have been formulated with the aim to obtain systems more environmentally friendly. Both RMs were studied by using different techniques such as dynamic light scattering (DLS) and 1H NMR. Additionally, spectroscopy techniques were used to obtain information such as critical micellar concentration and aggregation number of the system investigated. Our results show that both biobased solvents can be used to generate AOT RMs. Interestingly, even the maximum amount of water dispersed are similar for both RMs, and the sizes of the systems are not identical, being that the RMs are formulated in lim larger than in p-cym. Both the biobased solvent and RMs show interaction of the entrapped water and the interface; however, this interaction is different depending on the solvent employed to prepare the RMs. Thus, the interaction water-surfactant at the interface is weaker in p-cym/AOT than in lim/AOT RMs. We think that the different penetration of the external solvent to the interfacial region is the main reason for the facts observed. In this sense, the polarity of these biobased solvents could explain why the penetration of both biobased solvents is different, making the p-cym/AOT RMs less interactive and, therefore, with smaller droplets sizes values. In summary, the different capacities of these biobased solvents to penetrate into the AOT interface allow us to obtain a new interface with peculiar characteristics and therefore with diverse applications.Fil: Oyarzun, Mauricio. Pontificia Universidad Católica de Chile; ChileFil: Oliva, Guillermo. Pontificia Universidad Católica de Chile; ChileFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Pavez, Paulina. Pontificia Universidad Católica de Chile; Chil

Simulacion y evaluacion multicriterio de cuatro politicas de gestion de aprovisionamiento mono-articulo

74 p.El presente proyecto tiene por finalidad determinar principios de administración de la manutención de sitios web. Este proyecto considera la elección de una metodología que permita administrar el proceso de mantención, caracterizando el producto en términos de la perspectiva del usuario y del constructor de un sitio web. Con la utilización del análisis multicriterio se determinara un proceso de manutención caracterizando al producto desde el punto de vista de perfiles disciplinarios que permitan determinar y concentrar los esfuerzos manutención. Finalmente la metodología propuesta se aplicara a un caso practico que permita ejemplificar el proceso de manutención de un sitio web

Stochastic modelling reveals mechanisms of metabolic heterogeneity

Phenotypic variation is a hallmark of cellular physiology. Metabolic heterogeneity, in particular, underpins single-cell phenomena such as microbial drug tolerance and growth variability. Much research has focussed on transcriptomic and proteomic heterogeneity, yet it remains unclear if such variation permeates to the metabolic state of a cell. Here we propose a stochastic model to show that complex forms of metabolic heterogeneity emerge from fluctuations in enzyme expression and catalysis. The analysis predicts clonal populations to split into two or more metabolically distinct subpopulations. We reveal mechanisms not seen in deterministic models, in which enzymes with unimodal expression distributions lead to metabolites with a bimodal or multimodal distribution across the population. Based on published data, the results suggest that metabolite heterogeneity may be more pervasive than previously thought. Our work casts light on links between gene expression and metabolism, and provides a theory to probe the sources of metabolite heterogeneity

Polycystin-2 Is Required for Starvation- and Rapamycin-Induced Atrophy in Myotubes

Muscle atrophy involves a massive catabolism of intracellular components leading to a significant reduction in cellular and tissue volume. In this regard, autophagy, an intracellular mechanism that degrades proteins and organelles, has been implicated with muscle breakdown. Recently, it has shown that polycystin-2 (PC2), a membrane protein that belongs to the transient receptor potential (TRP) family, is required for the maintenance of cellular proteostasis, by regulating autophagy in several cell types. The role of PC2 in the control of atrophy and autophagy in skeletal muscle remains unknown. Here, we show that PC2 is required for the induction of atrophy in C2C12 myotubes caused by nutrient deprivation or rapamycin exposure. Consistently, overexpression of PC2 induces atrophy in C2C12 myotubes as indicated by decreasing of the myogenic proteins myogenin and caveolin-3. In addition, we show that inhibition of mTORC1, by starvation or rapamycin is inhibited in cells when PC2 is silenced. Importantly, even if PC2 regulates mTORC1, our results show that the regulation of atrophy by PC2 is independent of autophagy. This study provides novel evidence regarding the role of PC2 in skeletal muscle cell atrophy

New Roles of the Primary Cilium in Autophagy

The primary cilium is a nonmotile organelle that emanates from the surface of multiple cell types and receives signals from the environment to regulate intracellular signaling pathways. The presence of cilia, as well as their length, is important for proper cell function; shortened, elongated, or absent cilia are associated with pathological conditions. Interestingly, it has recently been shown that the molecular machinery involved in autophagy, the process of recycling of intracellular material to maintain cellular and tissue homeostasis, participates in ciliogenesis. Cilium-dependent signaling is necessary for autophagosome formation and, conversely, autophagy regulates both ciliogenesis and cilium length by degrading specific ciliary proteins. Here, we will discuss the relationship that exists between the two processes at the cellular and molecular level, highlighting what is known about the effects of ciliary dysfunction in the control of energy homeostasis in some ciliopathies

A vector model for routing queries in web search engines

This paper proposes a method for reducing the number of search nodes involved in the solution of queries arriving to a Web search engine. The method is applied by the query receptionist machine during situations of sudden peaks in query traffic to reduce the load on the search nodes. The experimental evaluation based on actual traces from users of a major search engine, shows that the proposed method outperforms alternative strategies. This is more evident for systems composed of a large number of search nodes which indicates that the method is also more scalable than the alternative strategies

Data from: Widespread infection of Areospora rohanae in southern king crab (Lithodes santolla) populations across south Chilean Patagonia

Cottage cheese disease is caused by microsporidian parasites that infect a wide range of animal populations. Despite its potential to affect economically important activities, the spatial patterns of prevalence of this disease are still not well understood. Here, we analyze the occurrence of the microsporidian Areospora rohanae in populations of the king crab Lithodes santolla over ca. 800 km of the southeastern Pacific shore. In winter 2011, conical pots were deployed between 50 and 200 m depth to capture crabs of a wide range of sizes. The infection was widely distributed along the region, with a mean prevalence of 16 %, and no significant association between prevalence and geographic location was detected. Males, females, and ovigerous females showed similar prevalence values of 16.5 (13 – 18.9), 15 (9.2 – 15), and 16.7 % (10 – 19 %), respectively. These patterns of prevalence were consistent across crab body sizes, despite the ontogenetic and sex-dependent variations in feeding behavior and bathymetric migrations previously reported for king crabs. This study provided the first report of the geographic distribution of A. rohanae infecting southern king crabs