Evaluation of chlorine, benzalkonium chloride and lactic acid as sanitizers for reducing Escherichia coli O157:H7 and Yersinia enterocolitica on fresh vegetables Velázquez, Lidia del Carmen; Barbini, Norma Beatriz; Escudero, María Esther; Lucero Estrada, Cecilia Stella Marys; Stefanini de Guzman, Ana Maria Teresa Valentina The effectiveness in the assurance of fresh vegetable microbiological quality of wash solutions containing 200 ppm free chlorine, 0.1 mg/ml benzalkonium chloride, 0.2% and 1% lactic acid was assessed on Escherichia coli O157:H7 and Yersinia enterocolitica contaminated lettuce and tomatoes. Y. enterocolitica reduction on tomatoes (5.08, 4.77 and 4.21 log after 0.2% lactic acid, 200 ppm chlorine and 0.1 mg/ml benzalkonium chloride treatments, respectively) were significantly higher than those for Y. enterocolitica on lettuce and E. coli O157:H7 on both vegetables. Antimicrobial treatment effects on bacterial counts and product quality after subsequent 7 day storage (4 C and 22 C) were determined. No pathogens were found in natural microflora of fresh vegetables.

Caracterización de productos co-cristalizados de sacarosa mediante Rayos X y DSC Deladino, Lorena; Navarro, Alba Sofia del Rosario; Martino, Miriam Nora The objective of the work was to characterize through X-rays, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), co-crystallized products within a sucrose matrix. These products contained mineral salts, ca1ciumlactate, magnesium suIphate and a lyophilized yerba mate extract (Ilex paraguariensis). The studied techniques allowed comparing the structure ofthe different products and the hydration state of the salts after the process. The co-crystallized products showed the basic crystalline structure of control sample of sucrose. In the case of the minerals, dehydration was not totally accomplished since different salt hydrate structures were detected.

Synthesis and anticonvulsant activity of amino acid-derived sulfamides Gavernet, Luciana; Elvira, Juan E.; Samaja, Gisela Anabel; Pastore, Valentina; Cravero, Mariana Sella; Enrique, Andrea Verónica; Estiu, Guillermina Lucia; Bruno Blanch, Luis Enrique Sulfamides are promising functions for the design of new antiepileptic drugs (Bioorg. Med. Chem. 2007, 15, 1556-1567; 5604-5614). Following previous research in this line, a set of amino acid-derived sulfamides has been designed, synthesized, and tested as new anticonvulsant compounds. The experimental data confirmed the ability of some of the structures to suppress the convulsions originated by the electrical seizure (MES test) at low doses (100 mg/kg).

'Durable Residues': Addressing the use of microwear, a case study from March Hill Briz Godino, Ivan; Alvarez, Myrian Rosa; Spikins, Penny; Needham. Andrew Different cultural and research traditions have led to distinctively different approaches tolithics analysis. An integration of different approaches can often give new ´ways ofseeing´ artefact assemblages and distribution patterns and provide valuable insights intopast activities. Here we present the preliminary results of a project integrating detailedanalytical techniques, focused on processes of production and consumption and socialdynamics in ethnarchaeological contexts in Tierra del Fuego with existing detailed lithicanalysis at Mesolithic sites in the Central Pennines. Such methods, taken fromArgentina (Álvarez) and Spain (Briz), that were developed in ethnoarchaeologicalcontexts employed detailed edge morphological analysis and use wear. When appliedto site A at March Hill, these techniques yielded interesting new insights about activitiesat the site, and provided a test case for such techniques.

Rotigotine transdermal delivery for the treatment of Parkinson's disease Rascol, Olivier; Perez Lloret, Santiago Background: Rotigotine is a non-ergot dopamine agonist that has been developed as a new transdermal formulation, and is indicated for use in early (USA and Europe) and advanced (Europe only) Parkinson's disease (PD). The potential advantages of the rotigotine patch include immediacy of effect onset as intestinal absorption in unneeded, constant drug delivery, and ease of use via application of a once-daily adhesive patch. An interesting element of this profile is constant drug delivery, which may avoid pulsatile dopaminergic stimulation, which has been postulated to be related to the development of motor complications. Objective: To consider the evidence surrounding the profile of rotigotine and, in particular, whether its constant delivery system offers significant benefits to the treatment of early and advanced PD. Methods: Source material was identified using a PubMed search for the term 'rotigotine' (up to March 2008). The review focuses only on publications related to the rotigotine indication for PD. Results/conclusion: The rotigotine transdermal patch demonstrates clinical efficacy, alongside a tolerability profile that appears to be well within the range of that observed with other non-ergot dopamine agonists. The once-daily patch formulation may favour compliance but, in similarity with the other theoretical advantages of constant drug delivery (for example reduced emergence of motor complications, improved tolerance to peripheral AEs), requires further detailed study.

Aminoguanidine impedes human pancreatic tumor growth and metastasis development in nude mice Mohamad, Nora Alicia; Criocco, Graciela P.; Sambuco, Lorena Andrea; Croci, Máximo; Medina, Vanina Araceli; Gutiérrez, Alicia Susana; Bergoc, Rosa Maria; Rivera, Elena Susana; Martín, Gabriela A. Aim: To study the action of aminoguanidine on pancreatic cancer xenografts in relation to cell proliferation, apoptosis, redox status and vascularization. Methods: Xenografts of PANC-1 cells were developed in nude mice. The animals were separated into two groups: control and aminoguanidine treated. Tumor growth, survival and appearance of metastases were determined in vivo in both groups. Tumors were excised and ex vivo histochemical studies were performed. Cell growth was assessed by Ki-67 expression. Apoptosis was studied by intratumoral expression of B cell lymphoma-2 protein (Bcl-2) family proteins and Terminal deoxynucleotidyl transferase biotin-dUTP Nick End Labeling (Tunel). Redox status was evaluated by the expression of endothelial nitric oxide synthase (eNOS), catalase, copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPx). Finally, vascularization was determined by Massons trichromic staining, and by VEGF and CD34 expression. Results: Tumor volumes after 32 d of treatment by aminoguanidine (AG) were significantly lower than in control mice (P < 0.01). Median survival of AG mice was significantly greater than control animals (P < 0.01). The appearance of both homolateral and contralateral palpable metastases was significantly delayed in AG group. Apoptotic cells, intratumoral vascularization (trichromic stain) and the expression of Ki-67, Bax, eNOS, CD34, VEGF, catalase, CuZnSOD and MnSOD were diminished in AG treated mice (P < 0.01), while the expression of Bcl-2 and GPx did not change. Conclusion: The antitumoral action of aminoguanidine is associated with decreased cell proliferation, reduced angiogenesis, and reduced expression of antioxidant enzymes.

Biología reproductiva de la serpiente semiacuática Liophis semiaureus (Serpentes, Colubridae) en el nordeste de Argentina Lopez, Maria Soledad; Giraudo, Alejandro Raul; Arzamendia, Vanesa; Chiaraviglio, Margarita Las serpientes tienen una notable flexibilidad y diversidad en sus tácticas reproductivas, a pesar de ello, los estudios acerca de la biología reproductiva de especies sudamericanas en zonas subtropicales-templadas son escasos. Se analizó la biología reproductiva de Liophis semiaureus en el nordeste de Argentina, incluyendo la madurez y dimorfismo sexual, fecundidad y ciclo reproductivo. Las hembras maduras fueron significativamente más largas, presentaron mayor peso corporal y alcanzaron la madurez sexual a una longitud mayor que los machos. Los machos tuvieron colas más largas que las hembras. El ciclo reproductivo fue estacional con mayor actividad en los períodos templados del año aunque previos a la época de inundaciones. Liophis semiaureus invirtió más energía en la reproducción que en el crecimiento, lo que posibilita que comiencen a reproducirse con tamaños más pequeños con respecto a otras poblaciones, sin retrasar su reproducción hasta alcanzar mayores tamaños. Esta puede ser una estrategia ventajosa en climas estacionales. Las características reproductivas y de dimorfismo sexual en L. semiaureus se encontrarían influenciadas por aspectos filogenéticos, geográficos y ecológicos, lo que determina que la especie responda de manera general al patrón reproductivo del grupo taxonómico pero con particularidades propias determinadas por los factores geográficos y los requerimientos ecológicos.

Diversification of inflorescence development in The PCK clade (Poaceae: Panicoideae: Paniceae) Reinheimer, Renata; Zuloaga, Fernando Omar; Vegetti, Abelardo Carlos; Pozner, Raúl Ernesto In grasses, inflorescence diversification and its correlation with species evolution are intriguing and not well understood. Part of this problem lies in our lack of comprehension about the inflorescence morphological complexity of grasses. We focused our study on the PCK clade (named for phosphoenol pyruvate carboxykinase), a well‐supported monophyletic group for which the relationships among its taxa are not well resolved. Interestingly, the PCK clade has an extensive diversity of adult inflorescence forms. A comparative developmental approach can help us to understand the basis of such morphological differences as well as provide characters that can be used in phylogenetic studies of the group. Using SEM studies, we demonstrate that inflorescence morphology in this clade is even more complex than what is typically observed in adult forms. We describe a number of new characters, and some classical features previously used for taxonomic purposes are redefined on the basis of development. We also define four morphological groups combining adult inflorescence form and development, and we discuss some of the evolutionary aspects of inflorescence diversification in the PCK clade. Taxonomic delimitation among genera in the PCK clade remains confusing and unclear where molecular and morphological studies support different classifications.

Isolation of salmonella typhimurium from dead blue and gold macaws (ara ararauna); Aislamiento de Salmonella typhimurium a partir de guacamayas azul y amarillo (Ara ararauna) muertas Vigo, Germán Blás; Origlia, Javier Anibal; Gornatti Churria, Carlos Daniel; Piscopo, Miguel Victor; Salve, Angela; Caffer, María I.; Pichel, Mariana; Binsztein, Norma; Leotta, Gerardo Anibal Dos polluelos de guacamayas azul y amarillo (Ara ararauna) murieron por una salmonelosis fatal en la Provincia de Buenos Aires, Argentina. Las aves se examinaron por histopatología y microbiología. La Salmonella enterica subespecies enterica serovar Typhimurium fue aislada de hígado, bazo, corazón, pulmón, riñón e intestino de ambas aves. Todas las cepas fueron susceptibles a ampicilina, cefalotina, cefotaxima, enrofloxacina, ácido nadilixico, gentamicina, estreptomicina, cloranfenicol, fosfomicina, tetraciclina, nitrofurantoina y la combinación trimetoprim-sulfametoxazol. El perfil XbaI de la Salmonella Typhimurium aislada de los dos animales que compartían la misma jaula fueron idénticos mediante electroforesis en gel de campos pulsantes (por sus siglas en inglés PFGE), y mostraron un patrón único comparado con 301 aislamientos que están incluidos en la base de datos nacional de patrones de PFGE de Salmonella, denominada PulseNet. Este es el primer reporte que describe casos fatales de salmonelosis en guacamayas azul y amarillo.; Two blue and gold macaw (Ara ararauna) chicks died of fatal salmonellosis in Buenos Aires Province, Argentina. The birds were histopathologically and microbiologically examined. Salmonella enterica subspecies enterica serovar Typhimurium was isolated from the liver, spleen, heart, lung, kidney, and intestine of both birds. All strains were susceptible to ampicillin, cephalothin, cefotaxime, enrofloxacin, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, tetracycline, nitrofurantoin, and trimethoprim-sulfamethoxazole. The XbaI-PFGE profile of the Salmonella Typhimurium isolated from the two animals, which shared the same cage, was identical and showed a unique pattern compared with 301 isolates included in the PulseNet national database of Salmonella pulsed-field gel electrophoresis patterns. This is the first report that describes fatal cases of salmonellosis from blue and gold macaws.

Likelihood-Based Sufficient Dimension Reduction Cook, R. Dennis; Forzani, Liliana Maria We obtain the maximum likelihood estimator of the central subspace under conditional normality of the predictors given the response. Analytically and in simulations we found that our new estimator can preform much better than sliced inverse regression, sliced average variance estimation and directional regression, and that it seems quite robust to deviations from normality.

Design of multiproduct batch plants with units in series including process performance models Moreno, Marta Susana; Iribarren, Oscar Alberto; Montagna, Jorge Marcelo This work deals with the simultaneous optimization of process decision variables and the structure of multiproduct batch plants considering the duplication of units in series to perform a given unit operation. Performance process models allow expressing the size and time factors of the posynomial formulation as a function of the process variables with the highest impact on costs. They are added into the design problem and handled as extra constraints. Structural alternatives for the plant were defined in order to include the duplication of units in series. Thus, the problem is formulated as an optimization problem, using mixed integer nonlinear programming to minimize the total cost of the process, subjected to design specifications. The model application is illustrated with a process for the production of oleoresins. The convenience of including the duplication in series together with process variables in process optimization is tested through the resolution of various problem cases.

Liquid-Glassy Polymer Interphases: Diffusion Kinetics in Conditions of Unlimited Liquid Supply Tomba, Juan Pablo; Carella, Jose Maria; Pérez, Claudio Javier; Pastor, José M. We investigate evidences of diffusion controlled by mechanical relaxation of the glassy matrix, i.e. Case-II mechanism, in a series of liquid/glassy interphases formed by polystyrene (PS) and poly (phenylene oxide) (PPO) as liquid and glassy components respectively. Diffusion experiments were performed in conditions of unlimited supply of the liquid polymer, parallel to those in which Case-II has been effectively verified. Interphase profiles were obtained via optical sectioning with confocal Raman microspectroscopy. We observed that interphase diffusion kinetics were markedly Fickean, in contrast with interpretations from other authors that invoke Case-II to explain the mechanisms that rule interphase evolution in these systems. 

The correlation contracted schrodinger equation: An accurate solution of the G-particle-hole hypervirial Alcoba, Diego Ricardo; Valdemoro, C.; Tel, L. M.; Pérez-Romero, E. The equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd-order correlation transition matrix elements into the 2-body space is the so called correlation contracted Schrödinger equation (CCSE) (Alcoba, Phys Rev A 2002, 65, 032519). As shown by Alcoba (Phys Rev A 2002, 65, 032519) the solution of the CCSE coincides with that of the Schrödinger equation. Here the attention is focused in the vanishing hypervirial of the correlation operator (GHV), which can be identified with the anti-Hermitian part of the CCSE. A comparative analysis of the GHV and the anti-Hermitian part of the contracted Schrödinger equation (ACSE) indicates that the former is a stronger stationarity condition than the latter. By applying a Heisenberg-like unitary transformation to the G-particle-hole operator (Valdemoro et al., Phys Rev A 2000, 61, 032507), a good approximation of the expectation value of this operator as well as of the GHV is obtained. The method is illustrated for the case of the Beryllium isoelectronic series as well as for the Li2 and BeH2 molecules. The correlation energies obtained are within 98.80-100.09% of the full-configuration interaction ones. The convergence of these calculations was faster when using the GHV than with the ACSE. © 2009 Wiley Periodicals, Inc.

DFT Calculations of the Molecular Force Field of Vanadyl Nitrate, VO(NO3)3 Brandan, Silvia Antonia; Socolsky, Cecilia; Ben Altabef, Aída A structural and vibrational theoretical study for vanadyl nitrate was carried out. The Density Functional Theory (DFT) has been used to study vibrational properties. The structures were fully optimized at the B3LYP/6-31G *, B3LYP/6-311G *, and B3LYP/6-311 + G * levels of theory and the harmonic vibrational frequencies were evaluated at the same level. The calculated harmonic vibrational frequencies for vanadyl nitrate are consistent with their experimental IR and Raman spectra in gas and liquid phases. Through these calculations a precise knowledge of the normal modes of vibration was obtained, considering the coordination mode adopted by the nitrate group in the mirror plane as monodentate and bidentate. A total assignment of the observed bands in the vibrational spectra for vanadyl nitrate is proposed in this work. The nature of the V-O and V←O bonds in the compound was systematically and quantitatively investigated by means of the Natural Bond Order (NBO) analysis. The topological properties of the electronic charge density were analyzed employing Bader's Atoms in Molecules theory (AIM).

Temporal variation in abundance and fecundity of the invading copepod Eurytemora americana in Bahia Blanca Estuary during an unusual year Berasategui, Anabela Anhi; Hoffmeyer, Monica Susana; Biancalana, Florencia; Fernandez Severini, Melisa Daiana; Menendez, Maria Clara Temporal change of biotic and environmental variables was corroborated by a Mann–Whitney/Kruskal–Wallis non-parametric tests, with significant differences ( p 0.01) in all variables throughout the study. Abundance population results showed very high values in relation to those recorded in recent years in Bahı ́ a Blanca Estuary. This response could be due to the unusual combination of environmental factors (polar wave with temperatures 6 C and a drought period with high salinities, 32.7–36.6) recorded during the studied winter period. Significant positive correlations between abundance and salinity ( p < 0.01, n = 226), and hatching success ( p < 0.01, n = 25) as well as a significant negative correlation between abundance and chlorophyll a ( p < 0.01, n = 226) were found. Although E. americana shows a k-strategy within its annual pulse, it presented two markedly distinct behaviours depending on temporal environmental variability. From July to early september, when the estuary evidenced high salinity, low temperature and high food availability, E. Americana showed large females, large clutch size and high hatching success. When environmental conditions became unfavorable from September to October, small females, small clutch size and very low hatching success were observed. The latter is associated with diapause egg laying which ensures pop- ulation recruitment. According to our findings the particular combination of low temperatures, high salinities and high available food (i.e. variables which each year modulate its pulse) during 2007 winter– spring, favored the great development of E. americana . This invading species in its opportunistic role has managed to exploit a vacant niche in the estuary, developing two different behaviours within the k-strategy depending on change in environmental conditions.

Micromycetes on Austrocedrus chilensis. First record of Rebentischia from Argentina Bianchinotti, Maria Virginia; Sanchez, Romina Magali Rebentischia massalongii was collected growing on twigs from Austrocedrus chilensis. So far known only from the temperate zone of Europe and North America, this species is reported for the first time from Argentina and the Southern Hemisphere. The type specimen of R. costi, a species described from Brazil, was re-examined and is here considered an authentic species. A key to the accepted species of Rebentischia is provided.

Activation of Stat3 by heregulin/ErbB-2 through the co-option of progesterone receptor signaling drives breast cancer growth Proietti Anastasi, Cecilia Jazmín; Rosemblit, Cinthia; Beguelin, Wendy; Rivas, Martin Alfredo; Díaz Flaqué, María Celeste; Charreau, Eduardo Hernan; Schillaci, Roxana; Elizalde, Patricia Virginia Cross talk between the steroid hormone receptors for estrogen and progesterone (PR) and the ErbB family of receptor tyrosine kinases appears to be a hallmark of breast cancer growth, but its underlying mechanism remains poorly explored. Here we have highlighted signal transducer and activator of transcription 3 (Stat3) as a key protein activated by heregulin (HRG), a ligand of the ErbB receptors, through co-opted, ligand-independent PR function as a signaling molecule. Stat3 activation was an absolute requirement in HRG-induced mammary tumor growth, and targeting Stat3 effectively inhibited growth of breast cancer cells with activated HRG/ErbB-2 and PR. Our findings unravel a novel potential therapeutic intervention in PR- and ErbB-2-positive breast tumors, involving the specific blockage of PR signaling activity.

Spontaneous adsorption of 3,5-bis(3,5-dinitrobenzoylamino) benzoic acid onto carbon Paez, Julieta Irene; Strumia, Miriam Cristina; Passeggi, Mario Cesar Genaro; Ferron, Julio; Baruzzi, Ana Maria; Brunetti, Veronica Dendritic molecules contain multifunctional groups that can be used to efficiently control the properties of an electrode surface. We are developing strategies to generate a highly functionalized surface using multifunctional and rigid dendrons immobilized onto different substrates. In the present work, we explore the immobilization of a dendritic molecule: 3,5-bis(3,5-dinitrobenzoylamino) benzoic acid (D-NO2) onto carbon surfaces showing a simple and rapid way to produce conductive surfaces with electroactive chemical functions. The immobilized D-NO2 layer has been characterized using atomic force microscopy and cyclic voltammetry. D-NO2 adsorbs onto carbon surfaces spontaneously by dipping the electrode in dendron solutions. Reduction of this layer generates the hydroxylamine product. The resulting redox-active layer exhibits a well-behaved redox response for the adsorbed nitroso/hydroxylamine couple. The film permeability of the derivatized surface has been analyzed employing the electrochemical response of redox probes: Ru(NH3)6 3+/Ru(NH3)6 2+ and Fe(CN)6 3−/Fe(CN)6 4−. Electrocatalytic oxidation of nicotinamide adenine dinucleotide onto a modified carbon surface was also observed.

Design of dynamic experiments in modeling for optimization of batch processes Martínez, Ernesto Carlos; Cristaldi, Mariano Daniel; Grau, Ricardo José Antonio Finding optimal operating conditions fast with a scarce budget of experimental runs is a key problem to speeding up the development of innovative products and processes. Modeling for optimization is proposed as a systematic approach to bias data gathering for iterative policy improvement through experimental design using first-principles models. Designing dynamic experiments that are optimally informative in order to reduce the uncertainty about the optimal operating conditions is addressed by integrating policy iteration based on the Hamilton-Jacobi-Bellman optimality equation with global sensitivity analysis. A conceptual framework for run-to-run convergence of a model-based policy iteration algorithm is proposed. Results obtained in the fed-batch fermentation of penicillin G are presented. The well-known Bajpai and Reuss bioreactor model validated with industrial data is used to increase on a run-to-run basis the amount of penicillin obtained by input policy optimization and selective (re)estimation of relevant model parameters. A remarkable improvement in productivity can be gain using a simple policy structure after only two modeling runs despite initial modeling uncertainty.

Sunflower Lecithin: Application of a Fractionation Process with Absolute Ethanol Cabezas, Dario Marcelino; Diehl, Bernd W. K.; Tomás, Mabel Cristina Native or modified lecithins are widely used as a multifunctional ingredient in the food industry. A fractionation process of sunflower lecithin (a non GMO product) with absolute ethanol was used for obtaining enriched fractions in certain phospholipids under different experimental conditions (temperature 35-65 °C, time of fractionation 30-90 min, ethanol/lecithin ratio 2:1, 3:1). Phospholipid enrichment in PC and PI fractions was obtained and analyzed by 31P NMR determinations. The percent extraction coefficients for different phospholipids (%EPC, %EPE and %EPI) in both fractions were calculated. Values of %EPC in PC fractions significantly increased (p < 0.05) from 12.8 (35 °C, 30 min, 2:1) to 57.7 (65 °C, 90 min, 3:1) at increasing temperature and incubation time. %EPE varied from 3.0 to 18.3 in the same fraction while %EPI presented lower values (<3%) under all the conditions assayed. The study of the effect of the operating conditions on the fractionation process evidenced a relevant influence of temperature, incubation time and to a minor extent of the ethanol/lecithin ratio on the enriched fraction yield% and selectivity of the main phospholipids (PC, PI, PE) estimated by %EPL. Response surface methodology (RSM) was utilized to explain the influence of the different parameters to optimize this process.