Casimir energy between media-separated cylinders: the scalar case Lombardo, Fernando Cesar; Mazzitelli, Francisco Diego; Villar, Paula Ines; Dalvit, A. R. We derive exact expressions for the Casimir scalar interaction energy between media-separated eccentric dielectric cylinders and for the media-separated cylinder-plane geometry using a mode-summation approach. Similarly to the electromagnetic Casimir-Lifshitz interaction energy between fluid-separated planar plates, the force between cylinders is attractive or repulsive depending on the relative values of the permittivities of the three intervening media.

High rates of bovine blastocyst development after ICSI-mediated gene transfer assisted by chemical activation Bevacqua, Romina Jimena; Pereyra Bonnet, Federico Alberto; Fernandez Martin, Rafael; Salamone, Daniel Felipe In order to establish conditions for intracytoplasmic sperm injection-mediated gene transfer (ICSI-MGT) in cattle, various aspects of fertilization and embryonic development were assessed after five activation treatments. Spermatozoa were co-incubated with pCX-EGFP (pCX-enhanced green fluorescent protein gene) plasmid and injected into metaphase II oocytes, which were then treated with ionomycin (Io), before further activation with the following agents: 6-dimethylaminopurine (Io-DMAP), additional Io plus DMAP (2Io-DMAP), Io alone (2Io), ethanol (Io-EtOH), or strontium chloride (Io-SrCl2). Fertilization rates at 16 h after ICSI, presence of a condensed spermatozoon head on Day 4 (Day 0 = ICSI), blastocyst and EGFP expression rates on Day 7, and Oct-4 pattern of Day 8 blastocysts were evaluated. Fertilization rates did not differ significantly among treatments. All (100%) of EGFP-positive embryos resulted from ICSI fertilization, whereas at least 60% of EGFP-negative embryos (>4 cells) had a condensed sperm head. Blastocyst rates after 2Io-DMAP were not significantly different from Io-DMAP or Io-EtOH, but they were higher than 2Io or Io-SrCl2 treatments (25.9, 18.7, 14.7, 9.4, and 10.9% respectively; P < 0.05). Transgene expression rates were higher for Io-DMAP, 2Io-DMAP and Io-SrCl2 than for 2Io and Io-EtOH (52.3, 53.0, 42.8, 28.2, and 29.4% respectively; P < 0.05). Over 80% of the blastocysts expressed egfp protein. In conclusion, ICSI-MGT was a powerful technique to produce bovine embryos that expressed the EGFP transgene. Moreover, the actual efficiency of ICSI-MGT could be readily evaluated by this method, which uses a marker expressed early in embryo development.

Chronic cannulation in the small intestine of feral pigeons (Columba livia) to assess bioavailability Chediack, Juan Gabriel; Cid, Fabricio Damian; Fasulo, S. V.; Caviedes Vidal, Enrique Juan Raul We improved a method of chronic duodenal cannulation to study intestinal transport of solutes in an in vivo model (pigeon, Columba livia). A hypoallergenic cannula was inserted into the proximal part of the small intestine of pigeons and used for solution administration. Recovery from surgery was extremely rapid and animals started eating and drinking within a day. After surgery, the body mass of cannulated pigeons was stable, and no adverse effects in the weight could be detected. The method is simple, economical and useful to determine intestinal bioavailability of solutes, for nutritional and ecological studies, in intact animals without influence of anesthesia.

Nitric oxide synthase-like dependent NO production enhances heme oxygenase up-regulation in ultraviolet-B-irradiated soybean plants Santa Cruz, Diego Mario; Pacienza, Natalia Alejandra; Polizio, Ariel Héctor; Balestrasse, Karina Beatriz; Tomaro, Maria Lujan; Yannarelli, Gustavo Gabriel Heme oxygenase (HO) has antioxidant properties and is up-regulated by reactive oxygen species (ROS) in ultraviolet-B-irradiated soybean plants. This study shows that nitric oxide (NO) protects against oxidative damage and that nitric oxide synthase (NOS)-like activity is also required for HO-1 induction under UV-B radiation. Pre-treatments with sodium nitroprussiate (SNP), a NO-donor, prevented chlorophyll loss, H2O2 and View the MathML source accumulation, and ion leakage in UV-B-treated plants. HO activity was significantly enhanced by NO and showed a positive correlation with HO-1 transcript levels. In fact, HO-1 mRNA levels were increased 2.1-fold in 0.8 mM SNP-treated plants, whereas subsequent UV-B irradiation augmented this expression up to 3.5-fold with respect to controls. This response was not observed using ferrocyanide, a SNP inactive analog, and was effectively blocked by 2-(4-carboxyphenil)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), a specific NO-scavenger. In addition, experiments carried out in the presence of NG-nitro-l-arginine methyl ester (l-NAME) or tungsten, well-known inhibitors of NOS and nitrate reductase, showed that NOS is the endogenous source of NO that mediates HO-1 expression. In summary, we found that NO is involved in the signaling pathway leading to HO-1 up-regulation under UV-B, and that a balance between NO and ROS is important to trigger the antioxidant response against oxidative stress.

Role of polymorphisms 919A>G and 2039A>G of FSH receptor (FSHR) gene in premature ovarian failure (POF) development Sundblad, Victoria; Chiauzzi, Violeta Alicia; Andreone, Luz; Campo, Stella Maris; Charreau, Eduardo Hernan; Dain, Liliana Beatriz Although the impact of polymorphisms 919A>G and 2039A>G of FSHR gene in normal ovarian function is almost clear, in Premature Ovarian Failure (POF) it still remains elusive. To analyse the putative association of these polymorphisms with POF development, 97 POF patients and 72 women over 40 years of age with normal menstrual record were genotyped for 919A>G and 2039A>G variants. No association was found between genotype GG of each polymorphism and the risk of POF. Nevertheless, ten POF patients and only one control presented the less common combinations 919G-2039A and 919A-2039G (p<0.05). In addition, the frequency of primary amenorrhoea and the occurrence of familial POF were significantly increased among patients with 919GG-2039GG genotype. In 45 normally menstruating women, no significant differences were found among different FSHR genotypes in FSH, E2, Inhibin A and Inhibin B levels. In conclusion, FSHR polymorphism genotypes were not associated either to the risk of POF or to serum hormone levels of control women. However, 919GG-2039GG genotype might be associated to relatively more severe symptoms of POF. On the other hand, the differences found between controls and patients in the prevalence of the cross haplotypes, may suggest that these rare allelic variants might possibly influence POF development.

Histamine receptors and cancer pharmacology Medina, Vanina Araceli; Rivera, Elena S. Considerable evidence has been collected indicating that histamine can modulate proliferation of different normal and malignant cells. High histamine biosynthesis and content together with histamine receptors have been reported in different human neoplasias including melanoma, colon and breast cancer, as well as in experimental tumours in which histamine has been postulated to behave as an important paracrine and autocrine regulator of proliferation. The discovery of the human histamine H(4) receptor in different tissues has contributed to our understanding of histamine role in numerous physiological and pathological conditions revealing novel functions for histamine and opening new perspectives in histamine pharmacology research. In the present review we aimed to briefly summarize current knowledge on histamine and histamine receptor involvement in cancer before focusing on some recent evidence supporting the novel role of histamine H(4) receptor in cancer progression representing a promising molecular target and avenue for cancer drug development.

Phenolic compounds from Pterocaulon alopecuroides Alarcón, Silvia Rosana; Pacciaroni, Adriana del Valle; Peñaloza, Lidia; Uriburu Monasterio, Maria Laura; Boemo, Analía; Sosa, Virginia Estela Aerial parts of Pterocaulon alopecuroides (Lam.) DC. (Asteraceae), were collected at the flowering stage in December 2003 in Salta, Argentina. The identification was carried out by Ing. Julio Tolaba. A voucher specimen (n° 3399) is on deposit at the Museo de la Facultad de Ciencias Naturales, Universidad Nacional de Salta, Salta, Argentina.

The symmetric Radon-Nikodým property for tensor norms Carando, Daniel Germán; Galicer, Daniel Eric We introduce the symmetric-Radon-Nikodým property (sRN pr operty) for finitely generated s-tensor norms β of order n and prove a Lewis type theorem for s-tensor norms with this property. As a consequence, if β is a projective s-tensor norm with the sRN prop- erty, then for every Asplund space E , the canonical map e ⊗ n,s β E ′ → e ⊗ n,s β ′ E ′ is a metric surjection. This can be rephrased as the isometric isomorph ism Q min ( E ) = Q ( E ) for certain polynomial ideal Q . We also relate the sRN property of an s-tensor norm with the A splund or Radon-Nikodým properties of different tensor products. S imilar results for full tensor products are also given. As an application, results concern ing the ideal of n -homogeneous extendible polynomials are obtained, as well as a new proof o f the well known isometric isomorphism between nuclear and integral polynomials on As plund spaces.

Algunas aclaraciones acerca del articulo “Linajes parentales amerindios en poblaciones del norte de Córdoba” (García A, Demarchi DA, Rev. Arg. Antrop. Biol. 8(1):57-71, 2006) Demarchi, Dario; García, Angelina En un número anterior de esta revista se publicó el artículo "Linajes parentales amerindios en poblaciones del norte de Córdoba" (García y Demarchi, 2006). En ese estudio se investigó la composición genética de una muestra de habitantes "criollos" de dos poblaciones del norte de Córdoba, a través del análisis de los marcadores del ADN mitocondrial que determinan los 4 principales linajes maternos amerindios y el marcador M3, del cromosoma Y, diagnóstico de linaje paterno amerindio. Se determinó la proporción de los linajes (haplogrupos) amerindios que sobreviven en esas localidades, se puso a prueba la existencia de  posibles variaciones significativas en la distribución de linajes entre ambas muestras y, por último, se establecieron similitudes con otros pueblos originarios del Cono Sur en la distribución de linajes maternos nativos. En el presente número, los lectores de la RAAB encontrarán una nota que se propone descalificar nuestro estudio a través de una serie de críticas. No es nuestro objetivo responder puntualmente a cada una de ellas sino más bien echar luz sobre algunas dudas que puedan surgir en los lectores a partir de las mismas.

The effect of the hydrocarbon-water interface structure on the behavior of an emulsion stabilized with dodecanephosphonic acid Verdinelli, Valeria; Messina, Paula Verónica; Schulz, Eduardo Nicolás; Salinas, Daniel Ricardo; Vuano, Bruno Mario; Schulz, Pablo Carlos We studied the phase transition of petroleum ether/water/n-dodecanephosphonic acid (DPA) from W/O to W/O/W emulsion when the neutralization degree (nd) of dodecanephosphonic acid (DPA) with NaOH was changed. We concluded that a phase transition from W/O emulsion to W/O/W emulsion occurs when nd≈0.47 due to a change in the structure of the polar layer at the oil/water interface from a tightly hydrogen-bonded layer to a less compact layer formed by -PO3H2 and -PO3H- groups in favor of an inversion. The W/O/W emulsion is probably caused by a partition of acid molecules in the water droplets interface inside the oil droplets, and monosodium phosphonate molecules at the external interface of oil droplets.

The unexpected diet of breeding Imperial Shags (Phalacrocorax atriceps) at the Nahuel Huapi Lake, Patagonia: implications on population trends? Casaux, Ricardo Jorge; Bertolin, María Lila; Tartara, Maria Alejandra; Alarcón, Pablo Angel Eduardo; Porro, Gerardo The Imperial Shag Phalacrocorax atriceps is widely distributed along the coast of South America and in Malvinas/Falkland Islands(Orta 1992). This shag is marine in most its range and forages predominantly on fish, although invertebrates were frequently reported as present in the diet(e.g., Punta etal. 2003, Ferrari et al. 2004, Bulgarella et al.2008)Reynolds (1934) reported the presence of the Imperial Shag breeding at Yehuin Lake,Tierra del Fuego, and later on Pereyra (1945, quoted in Navas 1970), Chebez & Gómez (1988) and Rasmussen et al. (1992) reported the existence of the only other three populations of this shag breeding in freshwater environments,the Nahuel Huapi (NHL),Fagnano, and Vintter lakes, respectively. Despite the potential interest in studying these populations, few studies provided information on the biology of this shag species. Although not globally threatened, the Imperial Shag at NHL is locally endangered and between the summers of 1990 (Rasmussen et.al. 1993) and 2005 (Pastore et al. 2005)the total number of individuals decreased in 68%. Thus,the aim of this study is provide the first information on the diet of the Imperial Shag breeding at NHL to improve the knowledge of the foraging behavior of this species as well as to explore the linkage between diet composition and the reported declining trend of this population.

La ciénaga afgana y la responsabilidad estadounidense Cuadro, Mariela El artículo analiza la actuación de las fuerzas de seguridad estadounidenses en Afganistán. A tal fin, se detiene en las distintas tácticas en juego en las esferas de poder en Washington. Detecta, entonces, un retorno al tratamiento hostil a los civiles afganos, produciéndose, entonces, una espiral que, se concluye, amenaza con transformarse en una guerra infinita.

Alto Chorrillo: otra alternativa para instalar una antena para ondas milimétricas y submilimétricas en Argentina Bareilles, Federico Ariel; Morras, Ricardo; Hauscarriaga, Fernando Pablo; Olalde, Juan Carlos; Guarrera, Leonardo; Arnal, Edmundo Marcelo We present preliminary data of atmospheric opacity at 210 GHz obtained between July 2009 and August 2010 at "Alto Chorrillo", a place near San Antonio de los Cobres, in the province of Salta at 4800 m above sea level. The data is compared with those obtained in the previous campaign con- ducted in Tolar Grande (also in Salta). Alto Chorrillo has a baseline larger than 130 km (E-W) regarding to ALMA, making it a good candidate to in- stall a radio astronomy facility that can operate in VLBI mode with ALMA.

Ultra Fast Response to Light Radiation in SnO2 Microrods Perillo, Patricia Maria; Rodriguez, Daniel Fabian; Rinaldi, Carlos Alberto; Lamagna, Alberto SnO2 microrods exhibited an ultra-fast photo-response when light led 402-940 nm was switched on and off. SnO2 microrods films were prepared with SnCl4 as the starting material. We found that increasing light radiation flux decreases the resistance. The effect of radiation on the film will be discussed as function of chemiabsorbed oxygen.

Ciudad letrada y dictadura: los espacios en Nocturno de Chile de Roberto Bolaño Aguilar, Paula O artigo explora a construção dos espaços urbanos no Chile da ultima ditadura no romance de Roberto Bolaño Nocturno de Chile. O analise indaga o tratamento das cumplicidades, responsabilidades e os medos no interior da „cidade letrada‟ que o autor expressa como reflexo de uma sociedade marcada pelo horror do poder ditatorial.; The article explores the representation of urban spaces in Chilean last dictatorship in Roberto Bolaño‟s Nocturno de Chile. The analysis studies complicity, responsibility and fear in „the lettered city‟ as a reflection of a society marked by the horrors of dictatorial power.

Photographs and silhouettes: visual politics in the human rights movement of Argentina Longoni, Ana Entre las distintas estrategias creativas desplegadas por las Madres de Plaza de Mayo y otros familiares dentro del movimiento de derechos humanos durante la última dictadura argentina (1976-1983), pueden reconocerse y contrastarse dos grandes matrices de representación visual de los desaparecidos: las fotos y las siluetas. Ambas surgieron (casi) en paralelo y tienen una larga historia, sin buscar oponerlas, sino más bien distinguir los sentidos desplegados en los distintos recursos y modos de producción simbólica que pudieron generar, así como reponer las coordenadas históricas en las que han devenido en signos que -en Argentina e incluso fuera de ella- remiten inequívocamente a los desaparecidos e incluso llegan a reconocerse como un lenguaje simbólico universal.

Intrasexual competition at work: Sex differences in the jealousy-evoking effect of rival characteristics in work settings Buunk, Abraham P.; aan't Goor, Joel; Castro Solano, Alejandro Sex differences in jealousy-evoking rival characteristics in the relationship with a supervisor at work were examined in a community sample of 188 individuals from Argentina. Among men, the rivals' social dominance and communal attributes evoked the most jealousy, followed by physical dominance. Among women, the rival's communal attributes evoked the most jealousy, followed by social dominance and physical attractiveness. For men physical dominance of the rival and for women physical attractiveness of the rival evoked relatively more jealousy, especially among those high in intrasexual competition and confronted with a same-sex supervisor. When confronted with an opposite-sex supervisor, social comparison orientation was associated with more jealousy in response to rivals with communal attributes. © The Author(s).

La individuación: una perspectiva sobre la cuestión del hombre Ferreyra, Diego Julián Este artículo se propone plantear la pregunta por el hombre fuera de los marcos clásicos que intentaron pensarlo en términos de género y de especies, o en términos de forma y materia. Para ello recurriremos al concepto de individuación tal como este fue desarrollado por Gilbert Simondon y retomado por Gilles Deleuze. Este concepto permite pensar al hombre a partir de las diferencias que lo constituyen y no a partir de su identidad en la representación. En lugar de partir de aquello que se pretende explicar (los individuos constituidos), se trata de comprender el proceso de su génesis a partir sus condiciones ontológicas: un fondo de puras diferencias que, lejos de disolver las formas, las produce.

Eutrophication and macroalgal blooms in temperate and tropical coastal waters: Nutrient enrichment experiments with Ulva spp. Teichberg, Mirta; Fox, Sophia E.; Olsen, Ylva S.; Valiela, Ivan; Martinetto, Paulina Maria del Rosario; Iribarne, Oscar Osvaldo; Muto, Elizabeti Yuriko; Petti, Monica A.V.; Corbisier, Thaïs N.; Soto-Jiménez, Martín; Páez-Osuna, Federico; Castro, Paula; Freitas, Helena; Zitelli, Andreina; Cardinaletti, Massimo; Tagliapietra, Davide Receiving coastal waters and estuaries are among the most nutrient-enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast-growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth-limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low- to high-nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high δ15N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.

Effect of di(2-ethylhexyl) phthalate (DEHP) on lipolysis and lipoprotein lipase activities in adipose tissue of rats Martinelli, Marcela Inés; Mocchiutti, Norberto Oscar; Bernal, Claudio Adrian The di(2-ethylhexyl) phthalate (DEHP) is an ubiquitous environmental chemical with detrimental health effects. The present work was designed to asses some potential mechanisms by which DEHP causes, among others, a reduced body fat retention. Since this effect could be related to an alteration of adipocyte triacylglycerol (TG) metabolism, we evaluated the effects of dietary DEHP in adipose tissues upon (1) the number and size of fat cells; (2) the basal and stimulated lipolysis and (3) the lipoprotein lipase (LPL) activity. Groups of male Wistar rats were fed for 21 days a control diet alone (control group) or the same control diet supplemented with 2% (w/w) of DEHP (DEHP group). The LPL activity of DEHP-fed rats was increased in lumbar and epididymal adipose tissues. These rats had significantly reduced weight in epididymal and lumbar tissues, together with reduced size of epididymal adipocytes. These alterations do not seem to be associated with higher lipid mobility because neither basal lipolysis nor in vitro stimulated lipolysis by noradrenaline (NA) showed to be modified by DEHP. Based on these results, we concluded that the adipose tissue size reduction induced by DEHP intake is not due to changes in lipolysis nor to a decreased LPL activity. More research is needed to achieve a comprehensive understanding of the potential mechanisms by which DEHP causes, among others, a reduced body fat retention.