Crack models with embedded discontinuities
Huespe, Alfredo Edmundo; Oliver, Javier
This chapter presents a methodological approach for modeling concrete crack problems based on continuum constitutive relations and strong discontinuity kinematics. Fundamentalaspects of this approach are presented in the initial Sections1 -2. The topics and ideas discussed in those points follow closely the work of Oliver et al.A Finite Element technique with embedded strong discontinuities, particularly adapted for this methodology, is shown in Section 3. In the final Sections 4- 6, some algorithmic aspects and several applications of the approach are addressed.
Dopaminergic regulation of food intake. Insights obtained from the dopamine receptor D2 knockout mouse
Garcia Tornadu, Isabel Andrea; Luque, Guillermina Maria; Pérez Millán, María Inés; Ramirez, Maria Cecilia; Recouvreux, Maria Victoria; Ornstein, Ana Maria; Diaz, Graciela Susana; Becu, Damasia
Dopamine D2 receptor (D2R) participation in prolactin regulation is well documented, but the role of D2Rs in the control of hormones and peptides involved in food intake and glucose metabolism has not been extensively studied. Dopamine regulates hunger and satiety by acting in specific hypothalamic areas, but the effects of dopamine on food intake have yielded conflicting results in the literature due to the different actions of dopamine on various hypothalamic nuclei, the involvement of multiple receptors, and different responses in food intake when administered systemically or locally into the hypothalamus. Studies using D2R knockout mice (Drd2-/-) put forward new insights into the role of the D2R in the regulation of food intake. In adult male and female Drd2-/- mice food intake per g BW is increased. In females disruption of the D2R produced two potentially anorexigenic events: an increase in serum and hypothalamic MSH, and a decrease in hypothalamic orexin expression. The very high chronic prolactin levels, found in this sex and genotype, probably counterbalance these effects. In Drd2-/- males, on the other hand, hypothalamic orexins, and serum and hypothalamic MSH were not modified, and therefore, moderate hyperprolactinemia may account for increased food intake. These results suggest a sexually dimorphic partici-pation of the D2R in food intake regulation, probably secondary to its regulation of prolactin secretion. A negative modulation of D2Rs on MSH release and a positive action on the hypothalamic expression of orexins is suggested, which may function to maintain food intake not far from equilibrium in the knockout mice. These results reveal a participation of multiple factors in D2R regulation of food intake, and are discussed in relation to the role of dopamine in food intake obtained in other studies. In humans, a reduction in D2Rs is associated with addictive behavior towards food or drugs, and individuals with low numbers of D2Rs may be more vulnerable to such behaviors including compulsive food intake. But, the involvement of dopamine in pathological eating and obesity is poorly understood. The evidence linking mutations of the D2R gene and obesity syndromes in humans is limited, and in general, loss of function mutations associate with overweight. Studies using the Drd2-/- mouse may help to clarify the mechanisms which link dopamine to food intake.
Flow-batch analyzer for the chemiluminescence determination of catecholamines in pharmaceutical preparations
Grunhut, Marcos; Martins, Valdomiro L.; Centurión, María Eugenia; Araújo, Mário Cesar Ugulino de; Fernández Band, Beatriz Susana
A novel, simple, cheap, flexible, versatile, and highly sensitivity flow-batch analyzer (FBA) with chemiluminescence detection was developed for determination of dopamine, norepinephrine, and epinephrine in pharmaceutical preparations. The method was based on the inhibitory effect of the mentioned catecholamines on a luminol-potassium hexacyanoferrate (III) chemiluminescence system in alkaline medium. The optimization of the chemical variables affecting this chemiluminescence inhibition effect has been carried out using a Box-Behnken experimental design. The sample throughput was 28 h-1. The system allowed the automatic preparation of standard solutions and analytical process can be accomplished just by changing the operational parameters in FBA control software.
Multiproduct batch plants design using linear process performance models
Moreno, Marta Susana; Montagna, Jorge Marcelo
In this contribution, a novel linear generalized disjunctive programming (LGDP) model is developed for the design of multiproduct batch plants optimizing both process variables and the structure of the plant through the use of process performance models. These models describe unit operations using explicit expressions for the size and time factors as functions of the process variables with the highest impact. To attain a linear formulation, values of the process variables as well as unit sizes are selected from a set of meaningful discrete values provided by the designer. Regarding structural alternatives, both kinds of unit duplications in series and in parallel are considered in this approach. The inclusion of the duplication in series requires different detailed models that depend on the structure selected. Thus, in a new approach for the multiproduct batch plant design, a set of potential structural alternatives for the plant is defined.
Occurrence of ornithodoros brasiliensis aragão (acari: Argasidae) in São Francisco De Paula, RS, Southern Brazil
Martins, J. R.; Doyle, R. L.; Barros Battesti, D. M.; Onofrio, V. C.; Guglielmone, Alberto Alejandro
There have been no reports of the endemic Ornithodoros brasiliensis (Aragão) in Rio Grande do Sul, southern Brazil, since the 1950s. In January 2007, 21 O. brasiliensis ticks were collected in a rural area named "Cruzinha" in the municipality of São Francisco de Paula, RS, and another population was sampled later that year (October) in Vargem do Cedro, another rural area of São Francisco de Paula, following reports of human parasitism by ticks. The reappearance of this tick is a reason for concern in terms of public health.
Asedios a una poética del espacio: Pretérito Perfecto de Hugo Foguet; Sieges to a Poetic of Space: Hugo Foguet’s Pretérito Perfecto
Aráoz, Isabel
El objetivo del presente trabajo es analizar la poética del espacio en la novela Pretérito perfecto (1983) del escritor argentino Hugo Foguet (1923-1985). A partir de esta idea distinguiremos el diseño de espacios interiores y públicos que entraman el argumento y revelan una multiplicidad de temporalidades yuxtapuestas. La novela enlaza el relato familiar y configura la imagen de una nación periférica. El relato de la historia de una ciudad provinciana es inseparable de un linaje aristocrático en decadencia.; The aim of this work is to analyze the poetics of spaces in the novel Pretérito perfecto (1983), created by the argentinian writer Hugo Foguet (1923-1985). Starting from this main idea, we are going to distinguish the designs of interior and public spaces, which constitute the plot, and reveal multiple and yuxtaposed temporalities. The novel connects the family narrative and configures the imagery of a peripheral nation. The telling of the history about a provincial city cannot be torn apart from an aristocratic lineage which is in decadence.
On local times, density estimation and supervised classification from functional data
Llop Orzan, Pamela Nerina; Forzani, Liliana Maria; Fraiman, Jacob Ricardo
In this paper, we define a n-consistent nonparametric estimator for the marginal density function of an order one stationary process built up from a sample of i.i.d continuous time trajectories. Under mild conditions we obtain strong consistency, strong orders of convergence and derive the asymptotic distribution of the estimator. We extend some of the results to the non-stationary case. We propose a nonparametric classification rule based on local times (occupation measure) and include some simulations studies.
Antifibrotic effects of pioglitazone at low doses on the diabetic rat kidney are associated with the improvement of markers of cell turnover, tubular and endothelial integrity, and angiogenesis
Toblli, Jorge Eduardo; Cao, Gabriel Fernando; Giani, Jorge Fernando; Angerosa, Margarita; Dominici, Fernando Pablo; Gonzalez Cadavid, Nestor F.
BACKGROUND/AIMS: Pioglitazone and other thiazolidinediones are renoprotective in diabetic nephropathy at doses that normalize glycemia, presumably as a consequence of glycemic control. However, low doses of pioglitazone that did not normalize glycemia in rat models of type 2 diabetes prevented tubulointerstitial fibrosis and glomerulosclerosis through counteracting inflammation, oxidative stress, cell cycle arrest, and fibrosis. The current work tested whether this low-dose treatment also reduces other fibrosis and inflammation factors in the diabetic kidney and prevents tubular cell loss, endothelial damage, and abnormal angiogenesis. METHODS: ZDF fa/fa rats (ZDF) were fed for 4 months chow with 0.001% pioglitazone, and the untreated ZDF and the non-diabetic lean Zucker rats (LZR) received regular chow. Proteinuria, creatinine clearance, blood pressure, and renal quantitative histopathology markers were determined. RESULTS: Correction of renal function in ZDF by pioglitazone, occurring with a glycemia >250 mg/dl, was accompanied by normalization of the renal levels of connective tissue growth factor and fibronectin (fibrosis), TNF-α, interleukin-6 and MCP-1 (inflammation), megalin (tubular cells), the PCNA/caspase-3 ratio (positive cell turnover), VEGF (abnormal angiogenesis), and the ratio between eNOS and iNOS (endothelial dysfunction). CONCLUSION: This supports mechanisms for the renoprotective effects of pioglitazone in diabetes additional to glycemic control.
Las tensiones internas del pluralismo moral; The internal tensions of moral pluralism
Lariguet, Guillermo Claudio
En este trabajo admito como hipó- tesis de trabajo filosófico que el pluralismo moral podría ser una mejor opción frente al monismo moral (aunque se pueda reconocer que, al final, los argumentos de uno y otro lado no puedan ser concluyentes). A partir de esta hipótesis de trabajo, caracterizo cuáles son las notas principales que definen un pluralismo —especialmente moral— de carácter «razonable». Sostengo que estas notas definitorias, que forman parte de las premisas de partida del pluralismo razonable, podrían comportar consecuencias que el propio pluralista no estaría fácilmente dispuesto a aceptar: en particular, un fuerte relativismo moral, un particularismo moral fuerte y una fragmentación de valores que podría derivar en desintegración moral. El seguimiento de estas posibles consecuencias, a su vez, depende de cuánta presión conceptual sobre las notas definitorias del pluralismo razonable ejerza el análisis conceptual preferido por el filósofo.; In this present work, I state, as a philosophical hypothesis of work, that moral pluralism could be a better option when it is confronted with monism (although it could be recognized that the arguments of both sides are not conclusive). From the point of view of this hypothesis, I attempt to characterize the main conceptual features of a «reasonable» pluralism In addition, I maintain that the possible implications of these features can imply some unacceptable consequences for the reasonable pluralist; in particular, some kind of moral particularism, some kind of moral relativism and some kind of fragmentation of values. In this last case the other consequence could be a so called «moral disintegration». My point is that these consequences depend on some sort of «conceptual pressure» exerted by different strategies designed by philosophers in their analysis of the concept of a reasonable pluralism.
Oligodendrocyte responses to buprenorphine uncover novel and opposing roles of μ-opioid- and nociceptin/orphanin FQ receptors in cell development: Implications for drug addiction treatment during pregnancy
Eschenroeder, Andrew C.; Vestal Laborde, Allison A.; Sanchez, Emilse Silvina; Robinson, Susan E.; Sato Bigbee, Carmen
Although the classical function of myelin is the facilitation of saltatory conduction, this membrane and the oligodendrocytes, the cells that make myelin in the central nervous system (CNS), are now recognized as important regulators of plasticity and remodeling in the developing brain. As such, oligodendrocyte maturation and myelination are among the most vulnerable processes along CNS development. We have shown previously that rat brain myelination is significantly altered by buprenorphine, an opioid analogue currently used in clinical trials for managing pregnant opioid addicts. Perinatal exposure to low levels of this drug induced accelerated and increased expression of myelin basic proteins (MBPs), cellular and myelin components that are markers of mature oligodendrocytes. In contrast, supra-therapeutic drug doses delayed MBP brain expression and resulted in a decreased number of myelinated axons. We have now found that this biphasic-dose response to buprenorphine can be attributed to the participation of both the mu-opioid receptor (MOR) and the nociceptin/orphanin FQ receptor (NOP receptor) in the oligodendrocytes. This is particularly intriguing because the NOP receptor/ nociceptin system has been primarily linked to behavior and pain regulation, but a role in CNS development or myelination has not been described before. Our findings suggest that balance between signaling mediated by (a) MOR activation and (b) a novel, yet unidentified pathway that includes the NOP receptor, plays a crucial role in the timing of oligodendrocyte maturation and myelin synthesis. Moreover, exposure to opioids could disrupt the normal interplay between these two systems altering the developmental pattern of brain myelination.
Estudio de los efectos angiogénicos de materiales biocerámicos vítreos de tercera generación
Haro Durand, Luis Alberto; Gongora, Adrian Daniel; Gómez, Martin Carlos; Porto Lopez, Jose Manuel; Boccaccini, Aldo R.; Zago, María Paola; Baldi, Alberto; Gorustovich Alonso, Alejandro Adrian
El proceso angiogénico es crítico para la reparación y regeneración de tejidos. El objetivo del presente estudio in vitro fue evaluar los efectos pro-angiogénicos de los productos iónicos de disolución del vidrios bioactivos del sistema SiO2-CaO-Na2-O-P2O5 (45S5) y modificado por boro (45S5.2B) sobre células endoteliales humanas. En comparación al control, las células estimuladas con los productos iónicos de disolución del vidrio 45S5.2B evidenciaron mayor capacidad de proliferación, migración y nivel de expresión de citoquinas IL6 y bFGF. La actividad pro-angiogénica observada, señala que el vidrio bioactivo 45S5.2B tendría potencial aplicación en diferentes estrategias de medicina regenerativa e ingeniería de tejidos que requieran un alto grado de vascularización.
Viviendas bioclimaticas en Tapalque: sistema de climatización por muros acumuladores de calor (mac): resultados preliminares
Discoli, Carlos Alberto; Viegas, Graciela Melisa; San Juan, Gustavo Alberto
Se presenta el desarrollo de sistemas de climatización para invierno conformados por muros acumuladores de calor (MAC) y el análisis comparado de diferentes tecnologías. Los sistemas se diseñaron para climatizar prototipos de viviendas bioclimáticas emplazados en Tapalqué, provincia de Buenos Aires (36° 21´ Lat. Sur, 60° 61´ Long. Oeste). Están incluidos en la fachada norte del prototipo y conformados por una masa de acumulación compuesta por piezas apilables industrializadas construidas con dos tecnologías de hormigón, macizas y mixtas que incorporan vainas de PVC llenas con agua tratada. Están cubiertas con una vidriera de simple vidrio con protección nocturna. Se presentan los diseños tecnológicos, las etapas de industrialización, fabricación y montaje. Se realizaron simulaciones de los sistemas incorporados a la vivienda y mediciones en laboratorio. Las simulaciones registraron una mayor performance en locales con muros acumuladores mixtos. Las mediciones en banco de ensayo corroboraron una diferencia de 2°C en las temperaturas registradas en el interior de los locales.
Insulin modifies aging-related inhibition of 1-stearoyl, 2-achidonoylglycerol phosphorylation in rat synaptic terminals
Zulian, Sandra Edith; Ilincheta, Monica Graciela; Giusto, Norma Maria
The purpose of the present study was to analyze diacylglycerol kinase (DAGK) activity in synaptic terminals from cerebral cortex (CC) and hippocampus (Hp) from adult (3-4 month-old) and aged (26-28 month-old) rats. The effect of insulin through DAGK activity on synaptosomes from adult and aged rats was also analyzed under conditions favoring saturated or unsaturated phosphatidic acid (PA) formation, using exogenous di-palmitoil glycerol (DPG) or 1-stearoyl-2-arachidonoylglycerol (SAG) as substrates. Results showed that the enzymatic activity preferentially uses 1-stearoyl-2-arachidonoylglycerol (SAG) as substrate, thus indicating the presence of -type DAGK. A significant decrease in DAGK activity transforming SAG into PA was also observed in both tissues from aged rats. Western Blot detection of DAGK showed that enzyme content undergoes no changes with aging. [3H]inositol incorporation into phosphoinosites was also analyzed to evaluate the role of DAGK in their synthesis. Data obtained from 3H-inositol incorporation into phosphoinositides revealed that in synaptosomes from aged rats phosphatidylinositol (PI) synthesis is lower than in adult animals. Interestingly, in the presence of SAG, PI synthesis was restored to adult values. DAGK activity over SAG was more highly stimulated by insulin in CC and Hp synaptosomes of aged rats with respect to adult rats. On the other hand, insulin exerted a stimulatory effect on PI and phosphatidylinositol 4 phosphate (PI(4)P) synthesis in synaptosomal CC from aged rats. Taken together, our findings indicate that in aged rats insulin triggers a stimulatory mechanism that reverts the diminished synaptosomal ability to synthesize arachidonoyl phosphatidic acid (20:4 PA). The recovery of this PA species indicates that insulin positively regulates phosphoinositide synthesis.
A data-driven, two-temperature solar model with Alfven waves
van der Holst, B.; Manchester IV, W. B.; Frazin, R. A.; Vasquez, Alberto Marcos; Tóth, G.; Gombosi, T. I.
We have developed a new three-dimensional magnetohydrodynamic (MHD) solar wind model coupled to the Space Weather Modeling Framework (SWMF), that solves for the different electron and proton temperatures. The collisions between the electrons and protons are taken into account as well as the anisotropic thermal heat conduction of the electrons. The solar wind is assumed to be accelerated by the Alfv en waves. In this paper, we do not consider the heating of closed magnetic loops and helmet streamers, but do address the heating of the protons by the Kolmogorov dissipation of the Alfv n waves in open field line regions. The inner boundary conditions for this solar wind model are obtained from observations and an empirical model. The Wang-Sheeley-Arge model is used to determine the Alfv n wave energy density at the inner boundary. The electron density and temperature at the inner boundary are obtained from the differential emission measure tomography applied to the extreme ultraviolet images of the STEREO A and B spacecraft. This new solar wind model is validated for solar minimum Carrington rotation 2077 (November 20 through December 17, 2008). Due to the very low activity during this rotation, this time period is suitable for comparing the simulated Corotating Interaction Regions (CIRs) with in-situ ACE/WIND data. Although we do not capture all magnetohydrodynamic variables perfectly, we do find that the time of occurance and the density of CIRs are better predicted than by our previous semi-empirical wind model in the SWMF that was based on a spatially reduced adiabatic index to account for the plasma heating.
La reforma del Estado en la provincia de Córdoba en el tiempo inmediatamente posterior a la crisis del 2001: ¿Qué hay de nuevo?
Manzo, Alejandro Gabriel
El presente trabajo pretende reflexionar en torno al destino del “neoliberalismo” luego de la crisis del 2001. A tal fin realiza un análisis comparativo entre dos procesos de reformas estatales en la provincia de Córdoba: uno primero, activado en 1999 bajo los auspicios del Banco Mundial y del Banco Interamericano de Desarrollo y, otro segundo, puesto en marcha en el 2004 por el nuevo equipo del gobernador De La Sota. Se cierra el artículo con una mirada crítica sobre este último proceso.; This article pretends to analyze the destiny of “neoliberalism” after the crisis of 2001. To such purpose it realizes a comparative analysis between two State Reforms policies in the province of Córdoba: the first one, activated in 1999 under the patronages of the World Bank and the Inter-American Development Bank and, the second one, constructed in 2004 by the new administration of De La Sota. The article concludes with a critical view of the last mentioned process.
Agents That Learn What Argument to Select In Argumentation-Based Negotiations
Monteserin, Ariel José; Amandi, Analia Adriana
Argument selection is considered the essence of the strategy in argumentation-based negotiation. An agent, which is arguing during a negotiation, has to decide what arguments are the best to persuade the opponent. In fact, in each negotiation step, the agent must select an argument from a set of candidate arguments by applying some selection criterion. For this task, the agent observes some factors of the negotiation context, for instance trust in the opponent, expected utility, among others. Usually, argument selection mechanisms are defined statically. However, as the negotiation context varies from a negotiation to another, defining a static selection mechanism it is not useful. For this reason, we present in this paper a novel approach to personalize argument selection mechanisms in the context of argumentation-based negotiation. The selection mechanism defines a set of preferences that determine how preferable it is to utter an argument in a given context. Our approach maintains a hierarchy of preferences in order to learn new preferences and update the existing ones as the agent experience increases. We tested this approach in a simulated multiagent system and obtained promising results.
Trypanosoma cruzi I genotypes in different geographical regions and transmission cycles based on a microsatellite motif of the intergenic spacer of spliced-leader genes
Cura, Carolina Inés; Mejía Jaramillo, Ana M.; Duffy, Tomás; Burgos, Juan Miguel; Rodriguero, Marcela Silvina; Cardinal, Marta Victoria; Kjos, Sonia; Gurgel Gonçalves, Rodrigo; Blanchet, Denis; De Pablos, Luis M.; Tomasini, Nicolás; Da Silva, Alexandre; Russomando, Graciela Mabel; Cuba Cuba, Cesar A.; Aznar, Christine; Abate, Teresa; Levin, Mariano Jorge; Osuna, Antonio; Gurtler, Ricardo Esteban; Diosque, Patricio; Solari, Aldo; Triana Chávez, Omar; Schijman, Alejandro Gabriel
The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harbouring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia + Tc Id, Tc Ia + Tc Ie and Tc Id + Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time.
Justicia caballeresca en América
Lastra, Silvia Cristina
El subconsciente imaginario de los hispano-indianos, sin duda alguna, fue fuertemente configurado por la lectura y la audición de la narrativa caballeresca hispánica de los siglos XVI y XVII. Pero, aún hoy, es materia de conjetura la incidencia paratextual del discurso caballeresco no sólo como estímulo a la emulación de hazañas y vivencias maravillosas –la mirabilia–, sino como configurador y propulsor de un código regenerador-perfectivo en torno de una específica idea de la justicia.; Reading and listening to 16th and 17th century Hispanic chivalric stories undoubtedly configured the imaginary subconscious of HispanicIndians. But even today, we wonder about the paratextual influence of chivalric discourse not only as a factor for the emulation of prowesses and marvellous experiences –mirabilia–, but also as the configuring factor of a perfectiveregenerating code around a specific idea of justice.