Light induced reactions in cryogenic matrices
Gomez Zavaglia, Andrea; Fausto, Rui
In this chapter light induced reactions in cryogenic matrices are addressed, ranging from conformational isomerizations to complex bond-breaking/ bond-forming processes. These include reactions induced by radiation in both UV/visible and IR regions, and also photochemical processes where noble gas atoms participate directly, leading to formation of covalently bound noble gas containing molecules.
Households Refrigerators and Freezers
Mascheroni, Rodolfo Horacio; Salvadori, Viviana Olga
Household refrigerators and freezers are intended for keeping small volumes of many different foods and drinks simultaneously at low temperatures, as can be found in any household. These items require diverse storage temperatures (and relative humidities in many cases) and have different storage lives. With the exception of air conditioning, domestic refrigeration systems are primarily used for food storage.
Valores hacia el trabajo y motivaciones ocupacionales en estudiantes secundarios del segundo cordón urbano bonaerense
Moreno, Jose Eduardo; Caramés, Gisele Alejandra Mabel
Los Objetivos de este capítulo fueron: 1- estudiar las motivaciones ocupacionales y las metas personales que los adolescentes del conurbano bonaerense piensan que van a lograr mediante la elección de una carrera universitaria u ocupación escogida; 2- investigar los valores relativos al trabajo que los sujetos ponen en juego al realizar una elección vocacional y 3- determinar las características de la elección vocacional y ocupacional en estudiantes secundarios residentes en un distrito del segundo cordón urbano bonaerense.
La expresión del número verbal en toba
Zurlo, Adriana Alicia
En el trabajo se analiza desde un enfoque tipológico funcional, los rasgos morfosintácticos y semánticos del morfema -pek, el cual puede ocurrir junto a bases verbales transitivas e intransitivas del toba. Siguiendo a Corbett (2000), se lo interpreta como una marca de número verbal que permite codificar el número de veces en que se realiza el evento -aspecto iterativo o intensificador- y, a veces, el númerto de participantes involucrados en la acción.
Enzymatic hydrolysis of sunflower lecithins using a microbial PLA2
Cabezas, Dario Marcelino; Madoery, Diego Roberto; Diehl, Bernd W. K.; Tomás, Mabel Cristina
Sunflower (Helianthus annuus L.) has an extremely favorable agro-ecological environment for cultivation in Argentina. In this country, the whole harvest for oil production is considered as non-GMO. Sunflower lecithins are obtained by gum purification from raw oil in a degumming process, which is part of the refining process of raw vegetable oils. Food industry uses lecithins because of their multifunctional ingredients. Modification processes of the original phospholipid composition of native lecithin, such as enzymatic hydrolysis, are appropriate for certain applications. The enzymatic activity of a microbial PLA2 (phospholipase A2) on the major phospholipids (PC, PE, PI) of sunflower lecithin, and the effect of processing conditions (PLA2 concentration of 0.4, 2.0 ml/100 g lecithin, without or with the addition of CaCl2 0.4 M, pH 7-9 for 40-300 min) were studied. Phospholipid composition of the sunflower lysolecithins using 31P NMR and the degree of enzymatic hydrolysis associated with each phospholipid (%HPL) were determined. The influence of the operating conditions on the enzymatic hidrolysis was analyzed by the evolution of the lysophospholipid content (LPL) and LPL/total phospholipid percent (LPL/PLT%) using a response surface methodology (RSM). The results showed that the different hydrolyzed sunflower lecithins presented a high LPL concentration, with respect to native lecithins (LPL ≈ 1.1%), demonstrating the efficiency of the process. In particular, the concentration of PLA2 presented a strong influence on the hydrolysis. Different operating conditions allowed obtaining modified lecithins with a wide range of LPL/PLT% values (11.17-57.48%). Furthermore, the use of a microbial phospholipase gives the possibility of generating a spectrum of sunflower lecithins with different phospholipid composition, which functionality as bioactive agents could be applied to the development of foods with kosher and halal certification.
Robust Model Predictive Control for Time Delayed Systems
González, Alejandro Hernán; Odloak, Darci
Model Predictive Control (MPC) is frequently implemented as one of the layers of a control structure where a Real Time Optimization (RTO) algorithm - laying in an upper layer of this structure - defines optimal targets for some of the inputs and/or outputs (Kassmann et al., 2000). The main scope is to reach the most profitable operation of the process system while preserving safety and product specification constraints. The model predictive controller is expected to drive the plant to the optimal operating point, while minimizing the dynamic error along the input and output paths. Since in the control structure considered here the model predictive controller is designed to track the optimal targets, it is expected that for nonlinear process systems, the linear model included in the controller will become uncertain as we move from the design condition to the optimal condition. The robust MPC presented in this chapter explicitly accounts for model uncertainty of open loop stable systems, where a different model corresponds to each operating point of the process system. In this way, even in the presence of model uncertainty, the controller is capable of maintaining all outputs within feasible zones, while reaching the desired optimal targets. In several other process systems, the aim of the MPC layer is not to guide all the controlled variables to optimal targets, but only to maintain them inside appropriate ranges or zones. This strategy is designated as zone control (Maciejowski, 2002). The zone control may be adopted in some systems, where there are highly correlated outputs to be controlled, and there not enough inputs to control all the outputs. Another class of zone control problems relates to using the surge capacity of tanks to smooth out the operation of a process unit. In this case, it is desired to let the level of the tank to float between limits, as necessary, to buffer disturbances between sections of a plant. The paper by Qin and Badgwell (2003), which surveys the existing industrial MPC technology, describes a variety of industrial controllers and mention that they always provide a zone control option. Other example of zone control can be found in Zanin et al, (2002), where the authors exemplify the application of this strategy in the real time optimization of a FCC system. Although this strategy shows to have an acceptable performance, stability is not usually proved, even when an infinite horizon is used, since the control system keeps switching from one controller to another throughout the continuous operation of the process. There are several research works that treat the problem of how to obtain a stable MPC with fixed output set points. Although stability of the closed loop is commonly achieved by means of an infinite prediction horizon, the problem of how to eliminate output steady state offset when a supervisory layer produces optimal economic set points, and how to explicitly incorporate the model uncertainty into the control problem formulation for this case, remain an open issue. For the nominal model case, Rawlings (2000), Pannochia and Rawlings (2003), Muske and Badgwell (2002), show how to include disturbance models in order to assure that the inputs and states are led to the desired values without offset. Muske and Badgwell (2002) and Pannochia and Rawlings (2003) develop rank conditions to assure the detectability of the augmented model. For the uncertain system, Odloak (2004) develops a robust MPC for the multi-plant uncertainty (that is, for a finite set of possible models) that uses a non-increasing cost constraint (Badgwell, 1997). In this strategy, the MPC cost function to be minimized is computed using a nominal model, but the non-increasing cost constraint is settled for each of the models belonging to the set. The stability is then achieved by means of the recursive feasibility of the optimization problem, instead of the optimality. On the other hand, there exist some recent MPC formulations that are based on the existence of a control Lyapunov function (CLF), which is independent of the control cost function. Although the construction of the CFL may not be a trivial task, these formulations also allow the explicit characterization of the stability region subject to constraints and they do not need an infinite output horizon. Mashkar et al. (2006) explore this approach for the control of nominal nonlinear systems, and Mashkar (2006) extends the approach for the case of model uncertainty and control actuator fault. More recently, González et al. (2009) extended the infinite horizon approach to stabilize the closed loop with the MPC controller for the case of multi-model uncertainty and optimizing targets. They developed a robust MPC by adapting the non-increasing cost constraint strategy to the case of zone control of the outputs and it is desirable to guide some of the manipulated inputs to the targets given by a supervisory stationary optimization stage, while maintaining the controlled output in their corresponding zones, taking into account a finite set of possible models. This problem, that seems to interchange an output tracking by an input-tracking formulation, is not trivial, since once the output lies outside the corresponding zone (because of a disturbance, or a change in the output zones), the priority of the controller is again to control the outputs, even if this implies that the input must be settled apart from its targets. Since in many process systems, mainly from the chemical and petrochemical industries, the process model shows significant time delays, the main contribution of this chapter is to extend the approach of González et al. (2009) to the case of input delayed multi-model systems by introducing minor modifications in the state space model, in such a way that the structure of the control algorithm is preserved. Simulation of a process system of the oil refining industry illustrates the performance of the proposed strategy.
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.
