Neuronal and astroglial alterations in the hippocampus of a mouse model for type 1 diabetes Revsin, Yanina; Saravia, Flavia Eugenia; Roig, Paulina; Lima, Analia Ethel; de Kloet, E. Ronald; Homo Delarche, Francoise; de Nicola, Alejandro Federico The influence of diabetes mellitus on brain pathology is increasingly recognized. Previous contributions of our laboratory demonstrated in models of type 1 diabetes (nonobese diabetic and streptozotocin (STZ)-treated mice), a marked astrogliosis and neurogenesis deficit in hippocampus and increased expression of hypothalamic neuropeptides. In the present investigation, we further analyzed alterations of astroglia and neurons in the hippocampus of mice 1 month after STZ-induced diabetes. Results showed that these STZ-diabetic mice presented: (a) increased number of astrocytes positive for apolipoprotein-E (Apo-E), a marker of ongoing neuronal dysfunction; (b) abnormal expression of early gene products associated with neuronal activation, including a high number of Jun + neurons in CA1 and CA3 layers and dentate gyrus, and of Fos-expressing neurons in CA3 layer; (c) augmented activity of NADPH-diaphorase, linked to oxidative stress, in CA3 region. These data support the concept that uncontrolled diabetes leads to hippocampal pathology, which adjoin to changes in other brain structures such as hypothalamus and cerebral cortex.

Vibrational spectra of Hg3TeO6 and Hg2TeO5 Baran, Enrique José; Weil, Matthias The infrared and Raman spectra of the crystalline hexaoxotellurates Hg3TeO6 and Hg2TeO5 were recorded and discussed on the basis of a site symmetry analysis derived from known structural data. Approximate values for the Tesingle bondO bond force constants are reported and some comparisons with related species are made.

Arsenic concentration in water and bovine milk in Cordoba, Argentina. Preliminary results Pérez Carrera, Alejo Leopoldo; Fernandez Cirelli, Alicia The Chaco Pampean Plain of central Argentina constitutes one of the largest regions of high arsenic (As) groundwaters known, covering around 1r106 km2 (Smedley & Kinniburg, 2002; Farı´as et al. 2004). The high-As groundwaters are from Quaternary deposits of loess (mainly silt) with intermixed rhyolitic or dacitic volcanic ash (Nicolli et al. 1989, Smedley et al. 1998, 2002). Early in the last century an endemic disease due to contamination of drinking water with arsenic was recognised. This disease is called HACRE (Hidroarsenicismo Crónico Regional Endémico, Chronic Endemic Regional Hydroarsenism) and is connected with a particular type of skin cancer (Astolfi et al. 1981)

Pharmacokinetics and synovial fluid concentrations of flurbiprofen enantiomers in horses: chiral inversion Soraci, Alejandro Luis; Tapia, Maria Ofelia; Garcia, Jorge Flurbirpofen (FBP), a member of the 2-aryl propionate nonsteroidal anti-inflammatory drug class, has potent anti-inflammatory and analgesic properties. The commercial preparation is a racemic mixture of the R(−) and S(+) enantiomers of FBP. In this study, R(−) and S(+) FBP were used to investigate the metabolic chiral inversion. Each enantiomer was administered separately (0.25 mg/kg) and in a racemic mixture (0.5 mg/kg) intravenously to horses. Plasma and synovial concentration of each enantiomer was determined and the disposition of each was analyzed. After intravenous administration of R(−) FBP and S(+) FBP to horses no chiral inversion was detected. After the administration of the FBP racemate and individual enantiomers no differences were observed between pharmacokinetic parameters [t1/2â (h), Cl (L/h·kg), AUC (ìg·h/mL), Vss (L/kg) and MRT (h)] for R(−) and S(+) FBF. Synovial fluid concentrations of both FBP enantiomers were lower than plasma concentrations and no stereoselective differences were detected. These data indicate that the disposition of FBF in horses is not enantioselective and demonstrate a difference in the pharmacokinetic behavior of the enantiomers as compared with other 2-aryl-propionic acids, such as carprofen, ketoprofen and vedaprofen in the horse.

Primates fósiles en la Patagonia : elementos para una filogenia de los Platirrinos Tejedor, Marcelo Fabian Los primates fósiles de la Patagonia tienen enorme relevancia para comprender la sistemática y filogenia de los platirrinos neotropicales. En las provincias argentinas de Neuquén, Chubut y Santa Cruz, se han descubierto al menos 8 especies incluidas en 6 géneros de platirrinos fósiles del Mioceno inferior a medio. Estos son representantes de las subfmilias Cebinae, Pitheciinae y posiblemente Atelinae, y fueron datados entre 20 y 15.8 millones de años.

Double Hopf bifurcation analysis using frequency domain methods Itovich, Griselda Rut; Moiola, Jorge Luis The dynamic behavior close to a non-resonant double Hopf bifurcation is analyzed via a frequency-domain technique. Approximate expressions of the periodic solutions are computed using the higher order harmonic balance method while their accuracy and stability have been evaluated through the calculation of the multipliers of the monodromy matrix. Furthermore, the detection of secondary Hopf or torus bifurcations (Neimark–Sacker bifurcation for maps) close to the analyzed singularity has been obtained for a coupled electrical oscillatory circuit. Then, quasi-periodic solutions are likely to exist in certain regions of the parameter space. Extending this analysis to the unfolding of the 1:1 resonant double Hopf bifurcation, cyclic fold and torus bifurcations have also been detected in a controlled oscillatory coupled electrical circuit. The comparison of the results obtained with the suggested technique, and with continuation software packages, has been included.

Antioxidants and methimazole in the treatment of Graves' disease: Effect on urinary malondialdehyde levels Guerra, Liliana Noemi; Rios, Maria del Carmen; Miler, Eliana Andrea; Moiguer, Silvia; Karner, Mirta; Burdman, Jose Adolfo We have postulated that metabolic oxidation could be the source of signs and symptoms of hyperthyroidism. The present study was designed to evaluate urinary malondialdehyde levels in Graves' disease and compare this oxidative stress biomarker with the clinical evolution of patients suffering this illness. We evaluated the concentration of urinary and serum malondialdehyde (MDA) in 36 patients with Graves' disease. Patients were treated with the antithyroid drug methimazole (MMI; Group A) or antioxidant mixture (200 mg vitamin E, 3 mg β-carotene, 250 mg vitamin C, 1 mg Cu, 7.5 mg Zn, 1.5 mg Mn, and 15 μg Se; Group B). MDA concentrations were higher in hyperthyroid patients compared to euthyroid controls, and a positive correlation was observed between serum and urinary MDA levels. Group A decreased urinary MDA to control values. There was a positive correlation between the clinical score and the heart rate of patients with urinary MDA before and during the treatment with MMI (Group A). Similar results were observed after treatment with the antioxidant mixture. Urinary MDA might be a good parameter in the follow-up of patients during MMI treatment. We proposed that oxidative stress correlates with signs and symptoms of hyperthyroidism.

Insecticide resistance in Argentine populations of tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae); Resistência a Inseticidas em Populações Argentinas de Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) Lietti, Marcela; Botto, Eduardo Norberto; Alzogaray, Raúl Adolfo The tomato leafminer, Tuta absoluta (Meyrick), is one of the key pests of tomato in Argentina. Since its dispersal in the 1970s, chemical control has been the main method of controlling it. However, reduced efficacy of some of the recommended insecticides has been observed since the 1980s. The aim of this work was to study the toxicity of three insecticides widely used in chemical control of T. absoluta (abamectin, deltamethrin and methamidophos) on larvae from a laboratory susceptible population (CASTELAR) and two greenhouse populations (ROSARIO and BELLA VISTA). Insecticides were dissolved in acetone and topically applied to the mid-dorsal abdominal region of two-day old 4th instar larvae. LD50 values were estimated and the Resistance Ratio (RR) for each insecticide was calculated (RR = LD50 value of each greenhouse population/LD50 value of the susceptible population). ROSARIO and BELLA VISTA populations showed the following RRs values: > 68.38 for deltamethrin; 2.48 and 3.49 for abamectin, respectively; and 0.79 and 0.86 for metamidophos, respectively. Deltamethrin resistance observed in ROSARIO could be due to the high selective pressure exerted by pyrethroids in this location. Deltamethrin resistance in BELLA VISTA is more difficult to explain, because pyrethroids were scarcely used in the greenhouse where the insects were sampled. The incipient abamectin resistance detected in the BELLA VISTA population could result from the frequent use of this insecticide in this location, although natural variation can not be discarded.; A traça-do-tomateiro, Tuta absoluta (Meyrick), é uma das pragas chaves no tomateiro na Argentina. O controle químico tem sido o principal método de controle empregado a partir da sua dispersão nos anos 70. Contudo, tem-se observado uma redução na eficácia de alguns dos inseticidas recomendados a partir da década de 80. O objetivo deste trabalho foi estudar a toxicidade de três inseticidas amplamente usados no controle químico de T. absoluta (abamectina, deltametrina e metamidofós) em larvas de uma população susceptível de laboratório (CASTELAR) e duas populações colectadas em casa de vegetação (ROSARIO e BELLA VISTA). Inseticidas foram diluídos em acetona e aplicados topicamente na região dorsal mediana do abdome de larvas no segundo dia do quarto estágio larval. Para cada inseticida estimou-se o LD50 e calculou-se o Nível de Resistência (NR = LD50 de cada população de casa de vegetação/LD50 população de laboratório). As populações de ROSARIO e BELLA VISTA mostraram os seguintes NRs: > 68.38 para deltametrina; 2.48 e 3.49 para abamectina, respetivamente; e 0.79 e 0.86 para metamidofós, respetivamente. A resistência a deltametrina observada em ROSARIO pode ser resultante da alta pressão seletiva exercida pelos piretróides nessa localidade. A resistência incipiente a abamectina detectada em BELLA VISTA pode ter sido causado pelo uso freqüente do inseticida nessa localidade ou pode estar associada à variação natural.

Endothelin-1 stimulates the Na+/Ca2+ exchanger reverse mode through intracellular Na+ (Na+i)-dependent and Na+i-independent pathways Aiello, Ernesto Alejandro; Villa-Abrille, María Celeste; Dulce, Raul; Cingolani, Horacio Eugenio; Perez, Nestor Gustavo This study aimed to explore the signaling pathways involved in the positive inotropic effect (PIE) of low doses of endothelin-1 (ET-1). Cat papillary muscles were used for force and intracellular Na(+) concentration (Na(+)(i)) measurements, and isolated cat ventricular myocytes for patch-clamp experiments. ET-1 (5 nmol/L) induced a PIE and an associated increase in Na(+)(i) that were abolished by Na(+)/H(+) exchanger (NHE) inhibition with HOE642. Reverse-mode Na(+)/Ca(2+) exchanger (NCX) blockade with KB-R7943 reversed the ET-1-induced PIE. These results suggest that the ET-1-induced PIE is totally attributable to the NHE-mediated Na(+)(i) increase. However, an additional direct stimulating effect of ET-1 on NCX after the necessary increase in Na(+)(i) could occur. Thus, the ET-1-induced increase in Na(+)(i) and contractility was compared with that induced by partial inhibition of the Na(+)/K(+) ATPase by lowering extracellular K(+) (K(+)(o)). For a given Na(+)(i), ET-1 induced a greater PIE than low K(+)(o). In the presence of HOE642 and after increasing contractility and Na(+)(i) by low K(+)(o), ET-1 induced an additional PIE that was reversed by KB-R7943 or the protein kinase C (PKC) inhibitor chelerythrine. ET-1 increased the NCX current and negatively shifted the NCX reversal potential (E(NCX)). HOE642 attenuated the increase in NCX outward current and abolished the E(NCX) shift. These results indicate that whereas the NHE-mediated ET-1-induced increase in Na(+)(i) seems to be mandatory to drive NCX in reverse and enhance contractility, Na(+)(i)-independent and PKC-dependent NCX stimulation appears to additionally contribute to the PIE. However, it is important to stress that the latter can only occur after the primary participation of the former.

Plant functional traits, herbivore selectivity and response to sheep grazing in Patagonian steppe grasslands Cingolani, Ana María; Posse Beaulieu, Gabriela; Collantes, Marta Beatriz 1. In some ecosystems there is a positive feedback between forage quality and grazing intensity. This involves three components of plant tolerance to grazing: functional traits, herbivore selectivity and response to grazing. We analysed the relationships between these components at species and community levels in Patagonian steppe grasslands. 2. We measured plant functional traits [height, specific leaf area (SLA) and foliar toughness] and estimated sheep selectivity and grazing response indices for 35 plant species. Sheep selectivity indices were obtained from microhistological and species availability data, and grazing response indices from species abundances in sites with contrasting grazing intensities. We performed correlations and multiple regressions among the three types of variables across the pool of 35 species. 3. To analyse data at the community level, we computed weighted averages of traits and sheep selectivity indices for 34 floristic samples taken from each side of 17 fence lines with contrasting grazing intensities. Correlations between mean trait values and sheep selectivity across the 34 samples, and paired comparisons of those variables between sides of the fences, were performed. 4. Taller plants had leaves with lower SLA and/or higher toughness. Short species of intermediate toughness were selected more often by sheep, while SLA was not related to sheep selectivity. Short species with high SLA increased with grazing, while toughness and sheep selectivity were unrelated to grazing response. 5. At the community level, short swards with high average SLA had high selectivity indices and were more abundant on the most intensively grazed sides of fence lines. Leaf toughness was unrelated to other traits or to sheep selectivity, and showed no significant response to grazing. 6. Synthesis and applications. Intensive grazing can increase the forage value of grasslands by the creation of lawns dominated by tolerant species. However, results from this study showed that some plant species that were avoided by grazers also increased, indicating a potential risk of a shift in composition of grazing lawns towards states of low forage value. This suggests that periodic resting of lawns could be a good management strategy to favour palatable species, thereby minimizing the risk of undesirable shifts in the overall species composition.

Processes of Evolutionary Self-Organization in High Inflation Experiences Tohmé, Fernando Abel; Dabús, Carlos Darío; London, Silvia We study some features of the processes that have generated high inflation in Latin- American countries. The statistical evidence shows that these inflationary experiences are fractional brownian noises. Several authors showed that self-organized criticality (SOC) processes may constitute the best explanation of the origin of such noises. But this hypothesis requires that the underlying structure remains timeinvariant. We conjecture, instead, that the economic structures evolve in time being, at each stage of their evolution, self-organized structures. We find that such ESO (evolutionary self-organized) processes still generate fractional brownian noises. Thus, they seem to provide a better explanation for the economic phenomenon of high inflation.

Un código para la nación: familia, mujeres, derechos de propiedad y herencia en Argentina durante el siglo XIX Zeberio, Blanca Liliana La construcción de un nuevo orden social y político en la Argentina del siglo XIX presuponía, entre otros aspectos, la creación de un aparato jurídico institucional que sentara las bases de una sociedad centrada en el individuo como sujeto y creara reglas que aseguraran la consolidación de los mercados y de la propiedad privada...

Comunicación, energía y construcción: los pilares alemanes en el desarrollo tecnológico de Buenos Aires Mendez, Patricia Susana Este texto explica la historia de aquellas empresas de origen alemán instaladas en la Argentina de fines del siglo XIX y que perduraron hasta la década del 40. El análisis se centra en función de la productividad que tuvieron y su relación con la construcción; fundamentalmente, apoyadas en tres importantes renglones en el desarrollo tecnológico del país: la energía eléctrica, las comunicaciones y las construcciones en hormigón armado. Nombres como los de CATE, GEOPÉ, Dykerdoff and Widman y la Siemens en sus tres facetas se detallan desde su nacimiento, producción y obras realizadas en la ciudad de Buenos Aires.

Intoxicación por plantas tóxicas Tapia, Maria Ofelia; Murphy, Michael J. Los perros y gatos están expuestos a una variedad de plantas de interior y ornamentales en parques y jardines.

Educación terapéutica de las personas con diabetes tipo 2 Gagliardino, Juan Jose; Assad, Daniel; Gagliardino, Gabriel G.; Lahera, Elba; Rizzutti, Liliana; Zufriategui, Zulma Desde el capítulo 1 hemos venido diciendo que la diabetes mellitus (DM) es una enfermedad crónica que requiere tratamiento permenente a partir del momento de su diagnóstico. Ya en 1922 lo destacaba el Profesor Joslin y recientemente lo confirmaron diversos estudios previamente mencionados como Malmo, DCCT, UKPDS, DaQin, DPP2: “la educación de las personas con o en riesgo de desarrollar diabetes, es un componente esencial de las estrategias de prevención y tratamiento.”

"Computer, please, tell me what I have to do...": An approach to agent-aided application composition Campo, Marcelo Ricardo; Diaz Pace, Jorge Andres; Trilnik, Federico U. The process of starting to use any reuse technology is usually one of the most frustrating factors for novice users. For this reason, tools able to reduce the learning curve are valuable to augment the potential of the technology to rapidly build new applications. In this work, we present Hint, an environment for assisting the instantiation of Java applications based on software agents technology. Hint is built around a software agent that has the knowledge about how to use a reusable asset and, using this knowledge, is able to propose a sequence of programming activities that should be carried out in order to implement a new application satisfying the functionality the user wants to implement. The most relevant contribution of this work is the use of planning techniques to guide the execution of instantiation activities for a given technology.

Niveles de calidad de vida urbana y el estado de necesidades básicas en servicios e infraestructura Discoli, Carlos Alberto; San Juan, Gustavo Alberto; Rosenfeld, Elias; Martini, Irene; Barbero, Dante Andrés; Ferreyro, Carlos; Ramírez Casas, Jimena; Dicroce, Luciano; Dominguez, Cristina El trabajo expone aspectos teórico-conceptuales y resultados de un modelo de calidad de vida urbana (CVU). El mismo considera las interacciones entre los servicios básicos, la infraestructura y los aspectos ambientales, la cobertura y/o área de influencia y la opinión/percepción de los usuarios. Se elaboraron mapas orientados a territorializar y definir el estado de necesidades básicas relacionadas a los servicios urbanos y de infraestructura. Asimismo, se muestran las tendencias en términos de calidad de vida en función de la integración de diferentes aspectos urbanos y de su consolidación. Por último, se realizan algunas consideraciones metodológicas y operativas en cuanto a ventajas y limitaciones que se experimentan en la aplicación del modelo.; This work exposes theoretical-conceptual aspects and results of the quality of urban life model (CVU). It considers the interaction between the basic services, the infrastructure and environmental aspects, the influenced area, and users’ opinion/perception. Maps were elaborated that tend to express geographically and to define the basic necessities state related to the urban and infrastructure services. Tendencies are also shown in terms of life quality in function of different urban aspects integration and of their consolidation. Some methodological and operative considerations are carried out taking into account the advantages and limitations that are experienced in the application of the model.

Una visión global de la respuesta inmune Geffner, Jorge Raúl El sistema inmune permite que, a pesar de vivir en un ambiente densamente poblado de agentes microbianos potencialmente patógenos, sólo en pocas ocasiones suframos procesos infecciosos evidentes desde el punto de vista clínico. Más aún, cuando esto sucede, la infección suele resolverse con rapidez gracias al desarrollo de una respuesta inmune que integra mecanismos propios de las inmunidades innata y adaptativa...

Inmunidad innata: neutrófilos, macrófagos y células natural killer Trevani, Analía Silvina; Geffner, Jorge Raúl; Faimboin, Leonardo Mientras que sólo los linfocitos T y B componen las células de la inmunidad adaptativa, las células de la inmunidad innata comprenden un amplio abanico de tipos celulares. En sentido genérico, puede afirmarse que todas las células del organismo participan en la inmunidad innata, ya que son capaces de mediar diferentes mecanismos antimicrobianos. En el capítulo anterior, definimos la capacidad de los queratinocitos y células epiteliales de los tractos para orquestar una serie de respuestas tendientes a evitar la colonización de las superficies expuestas y eliminar los focos infecciosos que pudieran establecerse.

On limit cycle approximations in the van der Pol oscillator Padín, Mirta S.; Robbio, Federico I.; Moiola, Jorge Luis; Chen, Guanrong This paper applies bifurcation analysis to the well-known van der Pol oscillator to obtain approximations of its periodic solutions in the nearly sinusoidal regime. A frequency domain method based on harmonic balance approximations is used for small values of the bifurcation parameter. Moreover, a comparison with some other frequency domain approaches is also given. Finally, a total harmonic distortion is computed using the information provided by the frequency domain approach.