An Environment for Modeling and Managing the Process Design Process Gonnet, Silvio Miguel; Mannarino, Gabriela; Leone, Horacio Pascual; Henning, Gabriela Patricia A three-layer object based environment architecture (Client, Application Server and Server) to support the modeling and management of the process design process is presented. It guides the design process and explicitly maintains the evolution of the design knowledge as a consequence of each design decision that is adopted during a particular design project. The Client encapsulates the interface of the designer to the design environment. The Application Server is responsible for managing the designer requirements by resorting to the Server data. It manages the definition of generic design tasks and the administration of the scenarios that are generated when a particular design process is carried out. Design tasks are defined according to the Coordinates language syntax. Basically, a design process is viewed as a set of tasks that are linked by temporal relationships and/or a set of resources they share. Generic design tasks can be instantiated and used in a specific design project. The Server contains the data that are created, used or modified by the Application Server.

Analysis of dielectric properties of cytosine in aqueous solution Manzur, Maria Eugenia; Romano, Élida; Vallejo, S.; Wesler, S.; Suvire, Fernando Daniel; Enriz, Ricardo Daniel; Molina, María A. A. The dipole moment of cytosine in dilute aqueous solutions was experimentally determined through permitivity, refraction index and density measurements in order to study the solvent effect on the behaviour of cytosine under the action of a low frequency electric field. Buckingham's equation was used, and μexp = 7.99 D was obtained. A theoretical study was also undertaken which considered cytosine in isolation and in two association models of the solute with four and six molecules of water respectively. The data for the dipole moment as well as an estimation of the hydration energies were obtained from models evaluated at three theoretical levels: Semiempirical calculations (in particular the AM1 method), ab initio calculations at the RHF/6-31+G* level of theory and density functional theory (B3LYP/6-31+G*) for the inclusion of electronic correlation. Although the six water molecule model bonded by hydrogen bonds was shown to be the more stable one, the results of μexp confirm that both intermolecular association models are compatible.

Geometría óptima de canales viales urbanos en zona árida Papparelli, Alberto Hermes; Kurban, Alejandra Silvia; Cunsulo, Mario Esteban; Montilla González, Eduardo Alejandro Se estudian las relaciones dimensionales de los Canales Viales Urbanos (CVU) de la ciudad de San Juan, en función de la incidencia de la radiación solar global en invierno y verano, analizando los ángulos de visión al cielo. Se analiza un muestreo de Canales Viales Urbanos de la ciudad de San Juan, en los que se efectúan relevamientos de sus elementos constitutivos y se registran mediciones de radiación solar global, temperatura y humedad en invierno y verano. Analizando el comportamiento a la radiación en las dos direcciones cardinales típicas del trazado urbano: este-oeste y nortesur, se obtienen los Angulos Libres de Enmascaramiento Edilicio y los Angulos Netos de Visión al Cielo que consideran la obstrucción que producen la edificación y la arboleda urbana a la radiación solar respectivamente. Correlacionadas las gráficas de ambas estaciones se definen los ángulos de visión al cielo óptimos, obteniéndose los CVU que presentan los mejores comportamientos a la radiación solar, como un aporte al potencial bioclimático urbano.; The dimensional relationship of the Urban Lane Channel (ULCH) of the San Juan city, are studied. Those studies are made in relation to the incidence of the global solar radiation during winter and summer, analyzing the angles of sky vision. 112 ULCH are analyzed as an example of the urban space of the city of San Juan. In those examples, the measurement of the constitutive elements as well as the measurements of the global solar radiation, temperature and humidity are done, both during winter and summer. The angles of free mask and the net angles of sky view, considering the obstruction both of the buildings and public forest are obtained, analyzing the behavior of the solar radiation and differentiating them according to the two typical cardinal direction of the urban plan: east-west and north-south. In this way urban profiles are obtained presenting the best behavior with respect to the solar radiation , as a contribution to the urban bioclimatic potential.

Effect of Bacillus cereus Exocellular Factors on Human Intestinal Epithelial Cells Minnaard, Jessica; Humen, Martin Andres; Perez, Pablo Fernando To gain insight on the biological effects of the exocellular factors produced by Bacillus cereus, culture filtrate supernatants of different strains were coincubated with differentiated Caco-2 cells. Exocellular factors were able to detach enterocyte-like cells from the substratum after 1 h of incubation. In addition, microvilli effacing and dramatic changes on the cellular surface of enterocytes were found after incubation periods as short as 20 min. Since cell detachment was not inhibited by fetal calf serum, thiol activated cholesterol-binding cytolysin, cereolysin O, does not seem to be involved. Also, translocation of phosphatidylserine from the inner to the outer leaflets of the plasma membrane was demonstrated by using fluorescein isothiocyanate (FITC)-Annexin V. In contrast to the high capability of detaching Caco-2 cells shown by all the strains under study, the mitochondrial dehydrogenase activity was lowered by culture filtrate supernatants in a strain-dependent manner. For strain M2, the decrease in dehydrogenase activity was already evident after 30 min of incubation. Production of biologically active factors depends on the growth phase, and maximal activity was found in late exponential-early stationary phases. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of concentrated exocellular factors showed a very complex scenery supporting the multifactorial character of the biological activity of B. cereus.

C and Sr isotopic evolution of carbonate sequences in NW Argentina: Implications for a probable Precambrian-Cambrian transition Sial, A. N.; Ferreira, V. P.; Toselli, Alejandro Jose; Aceñolaza, Florencio Gilberto; Pimentel, M. M.; Parada, Marcela Alejandra; Alonso, Ricardo Narciso Upper Precambrian-Lower Cambrian sequences in the Tucuman, Salta and Jujuy provinces, NW Argentina, comprise sandstone, slate, conglomerate and black limestone (Las Tienditas/Volcan Fms.) with abundant Vendian/Tommotian trace fossils in the clastic facies rocks. The Precordillera basin, San Juan province, represents a continuous carbonate sequence belonging to the Lower to Middle Cambrian La Laja Fm. The Pie-de-Palo Range, Pampean Range, characterized by carbonates intercalated with greenschist/amphibolite facies metaclastic rocks, forms a part of the Precordillera basement. The δ13C values in carbonates of the Las Tienditas Fm. show a gradual decrease from the base (+3.4 ‰PDB) to the top with a minimum of -1.6‰ observed at ∼15m from the top, the latter having a higher clay content. Carbonates in a 700m thick section within La Laja Fm. is marked by a slightly positive δ13C values at the base (marly) with a negative anomaly (-2.0‰) at ∼20 m above, followed by a small positive anomaly (+0.5‰) ∼100 m from the base. All the values above this point are around -0.5‰ with a negative anomaly (-2.0‰) recorded at ∼240m above the base. Seawater 87Sr/86Sr values define a non-monotonic increase (0.70870 - 0.71082) through the carbonates in Las Tienditas Fm. while the La Laja Fm carbonates vary from 0.70926 to 0.71030, with higher values at the base. C and Sr isotopes, thus suggest that the Las Tienditas carbonates record the Precambrian-Cambrian transition (∼15m from the top of studied section). The same is also evident at ∼30 m from the base of the La Laja Fm. The narrow range of δ13C variation (-1.4 to + 1.3‰) and 87Sr/86Sr in the 0.709-0.710 range for the Caucete Group carbonates of the Pie-de-Palo Range, although unequivocally, appear to be in consonance with a Vendian to Tommotian age, reinforced by the presence of the trace fossils Didymaulichnus and Gordia.

Relationship of different ovarian stimulation response with vascular endothelial growth factor and degree of granulosa cell apoptosis. Quintana, R; Kopcow, L.; Marconi, G.; Sueldo, C.; Diradourian, M.; Barañao, Rosa Ines The aim of this study was to evaluate the concentration of vascular endothelial growth factor (VEGF) in follicular fluid and in granulosa cell cultures in relation to the degree of apoptosis in granulosa cells from patients with different types of ovarian response to controlled ovarian hyperstimulation. We studied 30 women who underwent controlled ovarian hyperstimulation and oocyte retrieval. Group A comprised patients with 1-4 follicles (n = 10), group B patients with 5-14 follicles (n = 10) and group C patients with >15 follicles (n = 10).

Absorption Kinetics of Sulfur Dioxide in Flint Corn during Steeping Haros, C. M.; Aguerre, Roberto Jorge; Suarez, C. A mathematical model was proposed to simulate simultaneous sulfur dioxide absorption and reaction during corn steeping. The parameters of the model, the diffusion coefficient and the reaction rate constant, were determined. The reaction rate of sulfur dioxide in corn grain followed first-order kinetics, with rate constants in the range 1.49×10-7to 9.78×10-7s-1for steeping temperatures from 25 to 55 °C. The Arrhenius activation energy for sulfur dioxide loss was 60.5 kJ/mol. The fitting of the mathematical model to the absorption curves determined the diffusion coefficient of sulfur dioxide in corn kernels. These varied from 1.17×10-11to 5.18×10-11m2/s for the temperature range 25-55 °C. Temperature-dependent diffusion coefficients was shown to obey the Arrhenius equation with an activation energy of 39.8 kJ/mol.

A quasilinearization approach for parameter identification in nonlinear abstract Cauchy problems Morin, Pedro; Spies, Ruben Daniel A quasilinearization approach to parameter identification in nonlinear abstract Cauchy problems in which the parameter appears in the nonlinear term, is presented. This approach has two main advantages over the classical one: it is much more intuitive and the derivation of the algorithm is done without need of the sensitivity equations on which classical quasilinearization is based. Sufficient conditions for the convergence of the algorithm are derived in terms of the regularity of the solutions with respect to the parameters. A comparison with the standard approach is presented and an application is included in which the nonphysical parameters in a mathematical model for shape memory alloys are estimated.

Effect of gallic acid and catechin on Lactobacillus hilgardii 5w growth and metabolism of organic compounds Alberto, Maria Rosa; Farias, Marta Elena; Manca, Maria Cristina The effects of different concentrations of (+)-catechin and gallic acid on the growth and metabolism of Lactobacillus hilgardii in different media were evaluated. These phenolic compounds at concentrations normally present in wine not only stimulated the growth rate but also resulted in greater cell densities during the stationary phase of growth in both media. During the first hours of growth both phenolic compounds activated the rate of glucose and fructose utilization and only catechin increased the malic acid consumption rate. Gallic acid and catechin were consumed from the beginning of L. hilgardii growth. All cited effects Were increased when the cells were precultivated in the presence of phenolic compounds, especially in the FT80 medium. As stimulating agents of L. hilgardii 5w growth, gallic acid and catechin could increase the risk of spoilage lactic acid bacteria in wine.

A method to obtain monosporic cultures of arbuscular mycorrhizal fungi Fracchia, Sebastian; Menendez, Ana Bernardina; Godeas, Alicia Margarita; Ocampo, J. A. We describe here a simple technique for obtaining monosporic cultures of AM fungi. Gigaspora rosea, Gi. sp., Glomus mosseae and G. sp. were used. One surface-sterilized spore was transferred to a 5-cm diameter Petri dish with 10 ml of 10 mM MES buffer, plus 0.04 g of Gel-Gro. The contents of a vermiculite-perlite (1/1, v/v) dish with 2-week-old clover seedlings were transferred onto the Gel-Gro medium with the germinated spore. All plants inoculated with single germinated spores developed mycorrhizas. With this system, non-destructive observation of development of hyphae, formation of fan-like structures, hyphal contact and penetration of AM fungi into the plant root was possible.

Temporal and spatial patterns of annelid populations in intertidal sediments of the Quequén Grande estuary (Argentina) López Gappa, Juan José; Tablado, Alejandro; Fonalleras, M.C.; Adami, Mariana Laura Temporal and spatial patterns of polychaete and oligochaete populations inhabiting intertidal sediments of the Quequén Grande estuary (Buenos Aires Province, Argentina) were analysed monthly during a yearly period. Local sediments are poorly selected, very fine sands, with a high percentage of mud. Two sites, located at both banks of the estuary were studied: (1) Site N, with a comparatively steep slope and percentage of mud increasing with sediment depth; (2) Site Q, with a gentle slope and percentage of mud increasing towards the sediment surface. The assemblage of annelids was characterised by a very low specific richness, being composed just by 4 species: The polychaetes Laeonereis acuta, Boccardiella ligerica and Capitella sp., and the tubificid oligochaete Ilyodrilus cf. frantzi. Density of the nereid L. acuta reached a peak in late summer and a minimum in spring. The population of Capitella sp. also showed maximum densities in summer, but collapsed during early fall, disappearing completely from the study area. Densities of I. cf. frantzi were highly variable in time and space. Three of the 4 species showed maximum densities at site Q, where mud content was highest at the sediment surface. At this sampling site, most of the L. acura population occurred within the upper 8 cm of the substrate. On the contrary, at site N, where mud and organic matter content increased with depth, this species was more abundant at subsurface layers (8-16 cm) than at the sediment surface.

An ab initio exploratory study of side chain conformations for selected backbone conformations of N-acetyl-L-glutamine-N-methylamide Tarditi, Ana Maria; Klipfel, Meghan W.; Rodriguez, Ana Maria; Suvire, Fernando Daniel; Chasse, Gregory A.; Farkas, Ödön; Perczel, AAndrás; Enriz, Ricardo Daniel The backbone potential energy surface (PES) (Ramachandran map) of N-acetyl-L-glutamine-N-methylamide has been studied at a,a side-chain orientation. Side-chain PESs at selected backbone conformations (γL and βL) were also studied. Side-chain-backbone interactions were analyzed in terms of energy and geometry.

Congenital goiter with hypothyroidism caused by a 5′ splice site mutation in the thyroglobulin gene Targovnik, Hector Manuel; Rivolta, Carina Marcela; Mendive, Fernando M.; Moya, Christian M.; Vono, Jussara; Medeiros Neto, Geraldo In this work we have extended our initial molecular studies of a consanguineous family with two affected goitrous siblings (H.S.N. and Ac.S.N.) with defective thyroglobulin (Tg) synthesis and secretion because of a homozygotic deletion of a fragment of 138 nucleotides (nt) in the central region of the Tg mRNA, identified previously in H.S.N. In order to identify the intron/exon boundaries and to analyze the regions responsible for pre-mRNA processing corresponding to a 138 nt deletion, we performed a screening of a human genomic library. The intron/exon junction sequences were determined from one positive clone by sequencing both strands of the DNA template. The results showed that the deletion mapped between positions 5549 and 5686 of the Tg mRNA and corresponded to exon 30. The positions of the exon limits differed by three nucleotides from the previously reported data obtained from direct sequencing of the deleted reverse transcriptase-polymerase chain reaction fragment from H.S.N. These variations are because the intron/exon junctions in this region were not available at the time when the deletion was first described. The deletion does not affect the reading frame of the resulting mRNA and is potentially fully translatable into a Tg polypeptide chain that is shortened by 46 residues. The same 138 nt deletion was observed in reverse transcriptase-polymerase chain reaction studies performed in the thyroid tissues from Ac.S.N. Genomic DNA analysis showed that a G to T transversion was observed at position +1 in the donor site of intron 30. Both affected patients (H.S.N. and Ac.S.N.) are homozygous for the mutation whereas the normal sister (At.S.N.) had a normal allele pattern. The functional consequences of the deletion are related to structural changes in the protein molecule that either could modify the normal routing of the translation product through the membrane system of the cell or could impair the coupling reaction. Probably the mutant Tg polypeptide might be functionally active in the production of thyroid hormone, because in the presence of a normal iodine ingestion (∼150 μg/day), Ac.S.N. was able to maintain normal serum levels of total triiodothyronine (T3) associated with relatively low serum total thyroxine (T4) with normal somatic development without signs of brain damage.

Curing of epoxy-urethane copolymers in a heated mold: Effect of the curing conditions on the phase-separation process Stefani, Pablo Marcelo; Moschiar, Stella Maris; Aranguren, Mirta Ines; Marieta, C.; Mondragon, I. The curing process of an epoxy-urethane copolymer in a heated mold was studied. The epoxy resin (DGEBA, Araldyt GY9527; Ciba Geigy), was coreacted with a urethane prepolymer (PU, Desmocap 12; Bayer) through an amine that acted as crosslinking agent (mixture of cycloaliphatic amines; Distraltec). The study focused on the effect of the curing condition and PU concentration on time-temperature profiles measured in the mold and the consequent final morphologies obtained. As the PU concentration increases, the maximum temperature reached in the mold decreases as a result of the dilution effect of the elastomer on reaction heat, whereas the Tg of the piece also decreases. Phase separation is a function of conversion and temperature reached in the curing part and was analyzed using experimental data and a mathematical model that predicts temperature and conversion throughout the thickness of the mold. Scanning electron microscopy and atomic force microscopy were used to determine the characteristics of the dispersed phase for the different formulations and conditions of curing. It was shown that the size of the dispersed phase increased with the initial PU concentration, whereas there were practically no differences in the separated phase as a function of position or temperature of curing (in the range of 70 to 100°C studied). The superposition of the phase diagrams with the conversion-temperature trajectories during cure provided an explanation of the morphologies generated.

Static and dynamic analyses of anisotropic plates with corner points Grossi, Ricardo Oscar; Lebedev, L. The present paper also deals with the application of the Ritz method to the determination of the natural frequencies of a rectangular anisotropic plate with a free corner formed by the intersection of two free edges. The resulting algorithm permits the analysis of anisotropic, orthotropic and isotropic materials. Accurate values can be obtained by incrementing the number of orthogonal polynomials, and the entire algorithm can be implemented on a personal computer. The software constitutes a useful tool in design work because of the great number of vibrating anisotropic plate problems that can be solved.

Varying c and particle horizons Chimento, Luis Pascual; Jakubi, Alejandro S.; Pavón, Diego We explore what restrictions may impose the second law of thermodynamics on varying speed of light theories. We find that the attractor scenario solving the flatness problem is consistent with the generalized second law at late time.

A variability analysis of low-latitude unidentified gamma-ray sources Torres, Diego F.; Romero, Gustavo Esteban; Combi, Jorge Ariel; Benaglia, Paula; Andernach, H.; Punsly, Brian We present a study of 40 low-latitude unidentified 3EG gamma-ray sources which were found to be not positionally coincident with any known class of potential gamma-ray emitters in the Galaxy (Romero et al. 1999). We have performed a variability analysis which reveals that many of these 40 sources are variable. These sources have, in addition, a steep mean value of the gamma-ray spectral index, < Γ > = 2.41 ± 0.2, which, combined with the high level of variability, seems to rule out a pulsar origin. The positional coincidences with uncatalogued candidates to supernova remnants were also studied. Only 7 sources in the sample are spatially coincident with these candidates, a result that is shown to be consistent with the expected level of pure chance association. A complementary search for weak radio counterparts was also conducted and the results are presented as an extensive table containing all significant point-like radio sources within the 40 EGRET fields. We argue that in order to produce the high variability, steep gamma-ray spectra, and absence of strong radio counterparts observed in some of the gamma-ray sources of our sample, a new class of objects should be postulated, and we analyze a viable candidate

Deficiencia de hierro en mujeres embarazadas y sus recién nacidos Buys, Maria Celia; Guerra, Lidia Noemi; Martin, Beatriz Lilia; Torrejón, Irma del Rosario; Miranda, Carmen E.; Sodero, Susana Introducción. La anemia ferropénica en embarazadas es frecuente y hemoglobinas (Hb) menores de 11 g%, se diagnostican como anemia. Indicadores como: ferritina sérica (Ferr) y saturación de transferrina (Sat%) miden reservas de hierro. Objetivos. Detectar anemia o deficiencia de hierro en embarazadas y recién nacidos (RN), correlacionar sus reservas de hierro, con el propósito de un oportuno diagnóstico y suplementación. Población. Se estudiaron 52 embarazadas normales de término y sus recién nacidos. Material y métodos. Se analizaron: hemoglobina (Hb), hierro sérico (Fe) y capacidad total de transporte de hierro por la transferrina (TIBC) por métodos colorimétricos y ferritina (Ferr) analizada por radioinmunoensayo (IRMA). El porcentaje de saturación surge de la relación Fe/TIBC. Se diagnosticó como anemia (valor ajustado a 1.200 m sobre el nivel del mar): Hb< 12,2 g% en madres y Hb< 16,8 g% en neonatos. Para el hierro, los puntos de corte fueron: para saturación<15% y Ferr< 15 ng/ml. Se denominó “deficiencia severa de hierro”, cuando Sat% y Ferr estaban por debajo del punto de corte y “deficiencia moderada”, al valor de Ferr< 15 o Sat%< 15. Resultados. El 67% de las madres tenía anemia: 57% deficiencia severa, 29% deficiencia moderada y 14%, no ferropénica. Del 33% de madres no anémicas, 24% tenían deficiencia severa (anemia latente) y 76%, deficiencia moderada. El 46% de neonatos tenía anemia. La deficiencia de hierro fue moderada: 4% en anémicos y 11% en no anémicos. Conclusiones. La anemia en embarazadas estudiadas es frecuente (67%), presentando el 14% de ellas anemia no ferropénica. El 100% de madres no anémicas presentaba deficiencia de hierro. El 46% de los neonatos tenía anemia pero sus reservas de hierro eran adecuadas en la mayoría.; Introduction. Ferropenic anemia with hemoglobin values below 11 g% is frequently found during pregnancy. Iron storage was measured by means of indicators such as serum ferritin and transferrin saturation. Objective. Early anemia detection and/or iron deficiency in pregnant women and their newborns. Correlation between iron storage in both, leading to early diagnosis and prevention. Material & methods. Hemoglobin (Hb), serum iron (Fe), and total iron binding capacity (TIBC) were determined by the colorimetric method. The saturation percentage was obtained through the relationship between Fe/TIBC. Ferritin (Ferr) was measured with an immunoradiometric assay (IRMA). Cut-offs for abnormal values of hemoglobin (adjusted to 1.200 m above sea level) were <12.2 g% for the mothers and <16.8% for the newborns. Cut-offs for ferritin values were 15 ng/ml and 15% for transferrin saturation values. Anemia was severe when both of these parameters of iron status were below normality and moderate when only one of them was below normal. Results. Anemic values were present in 67% of mothers. Fifty seven percent of them were severe, whereas 29% were moderate. In 14% the anemia was non-iron related. In the non anemic group (47%), 24% had a severe iron deficiency (latent anemia) and in 76% it was moderate. Forty seven per cent of the newborn were anemic. The iron deficiency was moderate in 4% of the anemic children, and in 11% of the non-anemic ones. Conclusion. An anemic condition was found in 67% of the pregnant women included in this study. Only in 14% the anemia was not related to a ferropenic condition. All the non-anemic mothers proved to be iron deficient. Forty six per cent of the neonates had anemia though their Fe reserves were adequate in most of them.

Electrical conductances of Tetrabutylammonium and Decamethylferrocenium Hexafluorophosphate in organic solvents Goldfarb, Darío L.; Longinotti, María Paula; Corti, Horacio Roberto The electrical conductances of tetrabutylammonium hexafluorophosphate in acetone and of decamethylferrocenium hexafluorophosphate in acetone, acetonitrile 1,2-dichloroethane, and dichloromethane have been measured at 25°C. The Walden product of the Bu4N+ cation and the PF-6 anion in acetone and other solvents is discussed in relation to the dielectric friction. The electric conductance at infinite dilution and the association constant of decamethylferrocenium hexafluorophosphate were determined in the four solvents investigated. The association constant of this electrolyte increases with decreasing reduced temperature, as expected in the framework of the association theory, within the primitive model of electrolytes.

Normal spatial learning and improved spatial working memory in mice (mus musculus) lacking dopamine d4 receptors Falzone, Tomas Luis; Avale, Maria Elena; Gelman, Diego Matias; Rubinstein, Marcelo Dopamine terminals in the hippocampus and prefrontal cortex modulate cognitive processes such as spatial learning and working memory. Because dopamine D4 receptors are expressed in these brain areas we have analyzed mutant mice lacking this receptor subtype (Drd4-/-). Wild-type and Drd4-/- mice were challenged in two spatial learning paradigms: the Morris water maze and an alternation T-maze. Drd4-/- mice showed normal place learning ability to find a hidden platform based on spatial extra-maze cues. In addition, Drd4-/- mice were able to find a new platform location with the same learning plasticity as wild type-mice. Spatial working memory assessed on a T maze showed that Drd4-/- mice were more efficient than wild-type mice in acquiring the maximum plateau of correct alternation scores. These results provide further evidence that the functional consequence of lacking D4 receptors is more evident in behaviors dependent on the integrity of the prefrontal cortex.