Historia de la vegetación de las llanuras costeras de la Bahía Samborombón (35° S), Argentina, desde 7800 14C años; Vegetation history of the coastal plains from Samborombon Bay (35.5° S), Argentina, since 7800 14C years Vilanova, Isabel; Prieto, Aldo Raul El análisis palinológico de una sucesión sedimentaria expuesta en la margen derecha del Río Salado (35° 55? S - 57° 53? O), a 30 km de la costa actual de la Bahía Samborombón, permitió reconstruir la historia de la vegetación del centro de la bahía desde c. 7800 14C años. Los resultados revelan el desarrollo de diferentes comunidades vegetales: una vegetación halófita de marisma media entre 7800 y 7000 14C años AP, reemplazada, entre 7000 y 5400 14C años AP, por pastizales salobres de marisma baja en relación con el máximo transgresivo del nivel del mar; una comunidad halófita de transición a una marisma alta entre 5400 y 4300 14C años AP; y un pantano salobre y pastizales entre 4300 y 1700 14C años AP, con disminución progresiva de las condiciones estuáricas por el descenso del nivel del mar y la progradación de cordones litorales. Estos resultados junto con los registros del sur de la Bahía Samborombón y de la llanura Mar Chiquita (sudeste bonaerense) reflejan una vegetación regional similar entre 5400 y 4300 14C años AP, de pastizales halófitos de marisma baja y laguna costera; y una diferenciación local con posterioridad a 4300 14C años AP en relación con la geomorfología de cada área: un pantano salobre en la Bahía Samborombón, comunidades psammófitas al sur de ésta y vegetación halófita de marisma media en la llanura Mar Chiquita. Estos cambios revelan la sensibilidad de la respuesta de la vegetación a las fluctuaciones del nivel del mar y evolución geomorfológica.; The palynological analysis from a sedimentary sequence, outcropping on the right bank of the Salado River (35°55′S - 57°53′W), 30 km from the present coastline of the Samborombon Bay, allowed to reconstruct the vegetation history for the central bay area since c. 7800 14C years BP. Results indicate the development of different plant communities: middle-marsh halophytic vegetation between 7800 and 7000 14C years BP, replaced by low-marsh brackish grasses between 7000 and 5400 14C years BP in relation to sea-level highstand; a transitional high salt-marsh halophytic community, developed between 5400 and 4300 14C years BP; and, brackish marsh vegetation and grasslands between 4300 and 1700 14C years BP, with progressive decrease of estuarine conditions due to sea-level fall and litoral ridge progradation. These results along with those from the south of the Samborombon Bay and Mar Chiquita coastal plain (southeastern Buenos Aires province) showed a similar vegetation in the region, characterized by low-marsh and coastal lagoon halophytic grasses, developed between 5400 and 4300 14C years BP; and a local differentiation after 4300 14C years BP related to the geomorphology of each area: a brackish marsh vegetation in the Samborombon Bay, psammophytic communities at the south of the bay and middle salt-marsh halophytic communities in Mar Chiquita coastal plain. These changes reveal the sensitive response of vegetation from coastal marshes to the sea-level fluctuations and geomorphologic evolution.

Rodent diversity and habitat use in a protected area of Buenos Aires province Argentina; Diversidad y uso del hábitat por roedores en un área protegida de Buenos Aires, Argentina Gomez Villafañe, Isabel Elisa; Expósito, Yanina; San Martín, Alvaro; Picca, Pablo Ignacio; Busch, Maria El uso del hábitat de los roedores está asociado a variables ambientales, requerimientos específicos e interacciones biológicas. El objetivo de este estudio fue analizar el uso del macro y microhábitat y la variación espacial en la abundancia de pequeños roedores que habitan la Reserva Natural Otamendi, Argentina. Estudiamos la comunidad de roedores en 6 ambientes: bosque ribereño, talares, pastizales bajos, pastizal salino y 2 pastizales altos. Capturamos 153 individuos de Scapteromys aquaticus, Akodon azarae, Oxymycterus rufus, Oligoryzomys flavescens, Deltamys kempi y O. nigripes, con un esfuerzo de 3 636 trampas-noche. La riqueza de especies se mantiene mediante la presencia de diferentes hábitats que satisfacen los requerimientos específicos tanto de especies especialistas como especies generalistas, usando diferencialmente la reserva y formando comunidades de diferente composición en cada ambiente. Se observó un uso diferencial a escala del macrohábitat de todas las especies y una selectividad a escala del microhábitat en individuos de 2 especies. Este estudio muestra que la diversidad de ambientes en la reserva natural permite el mantenimiento de especies silvestres de pequeños roedores, confirmando el valor ecológico y de conservación de la reserva situada dentro de una región urbanizada.; Habitat use of rodents is associated to environmental variables, species requirements and biological interactions. The aim of this study was to analyse the macro and microhabitat use and spatial variation in the abundance of small wild rodents that inhabit Otamendi Natural Reserve, Argentina. We studied the rodent communities in 6 habitats: riparian forest, Celtis tala forest, lowland grassland, salt marsh and 2 highland grasslands. We captured a total of 153 individual of Scapteromys aquaticus, Akodon azarae, Oxymycterus rufus, Oligoryzomys flavescens, Deltamys kempi and O. nigripes, with a trapping effort of 3636 trap-nights. The species richness is maintained by the presence of different habitats that satisfy specific requirements from specialist and generalist species, using differentially the reserve and forming communities of different specific composition in each habitat. A differential macrohabitat use was observed by all species, and a certain level of selectivity at microhabitat scale was observed in individuals of 2 species. This study shows that the diversity of environments in the Otamendi Natural Reserve, which allows the maintenance of many wild species of small rodents; confirming the high ecological and conservational value of the reserves inside an urban region.

The Role of Ghrelin in Reward-Based Eating Perello, Mario; Zigman, Jeffrey M. The peptide hormone ghrelin acts in the central nervous system as a potent orexigenic signal. Not only is ghrelin recognized as playing an important role in feeding circuits traditionally thought of as affecting body weight homeostasis, but also an accumulating number of scientific studies have identified ghrelin as being a key regulator of reward-based, hedonic eating behaviors. In the current article, we review ghrelin's orexigenic actions, the evidence linking ghrelin to food reward behavior, potential mechanisms by which ghrelin mediates reward-based eating behavior, and those studies suggesting an obligatory role for ghrelin in the changed eating behaviors induced by stress.

El perímetro de una cuenca hídrica: su tratamiento objetivo en la definición de índices geomorfológicos Barrera, Daniel Florencio; Presutti, Miriam Elisabet; Rosatto, Héctor Gustavo Para relacionar la forma de una cuenca con su respuesta hidrológica se utilizan comúnmente índices de forma adimensionales que incluyen su área A y perímetro “suavizado”, como el coeficiente de compacidad de Gravelius. El perímetro de una cuenca depende de la resolución espacial en la que se lo determine. A fin de tornar objetivos dichos índices, proponemos reemplazar el borde de la cuenca por una poligonal de “segmentos básicos” Sb iguales y consecutivos, quedando acotado el perímetro una vez elegido dicho segmento. Además, proponemos que Sb sea función de Raiz(A), y los índices de forma resulten invariantes con respecto al área, permitiendo comparar objetivamente cuencas de distinto tamaño. Se varió la longitud de Sb para tres cuencas diferentes, de modo que las poligonales resultantes eliminan ciertos detalles pero preservan la forma de la cuenca. Se comprobó un buen ajuste lineal log-log entre Sb y la cantidad de segmentos en el perímetro, comprobando así que el borde de cuenca se comporta como un objeto fractal. Se analizó la variación del coeficiente de Gravelius en función de la longitud de Sb. Se propone usar Sb=1/5 Raiz(A) para determinar los índices de forma, y Sb=1/20 Raiz(A) para los índices que relacionan longitudes de ríos.; Dimensionless shape indexes are usually used to relate the form of a watershed with their hydrological re-sponse. These indexes relate the area A and the “smoothed” perimeter of a watershed, like Gravelius compact-ness coefficient. The perimeter depends on the spatial resolution on which is determined. In order to turn ob-jective the shape index, we propose to replace the watershed border by a polygonal of “basic segments” Sb equals and consecutive, so the perimeter is delimited once the segment have been chosen. Furthermore, we propose to relate Sb to SquareRoot(A), making these indexes invariant with respect to A and turning possible to make objective comparisons. The length of Sb was varied from a quarter to twentieth of , in three different basins. At these levels of length, the polygonal remove certain details but preserve the shape of the watershed. It has been proof a good fit in a lineal log-log relationship between the basic segment and the quantity of seg-ments in the perimeter, proving that the watershed border behave like a fractal object. Furthermore, the varia-tion of the Gravelius coefficient in function of the length of the basic segment was analyzed. We propose to use Sb=1/5SquareRoot(A) for shape indexes, and Sb=1/20 SquareRoot(A) for indexes relating river lengths.

Predominance of human lymphotropic T cell virus type 2 subtype b in Urban populations of Argentina Berini, Carolina Andrea; Eirin, Maria Emilia; Delfino, Cecilia María; Weissenbacher, Mercedes Crecencia; Biglione, Mirna Marcela Human T-lymphotropic virus subtype b (HTLV-2b) infection has been described among aborigines from Northern Argentina, while HTLV-2a has been described in an injecting drug user (IDU) from a Central region, similar to the situation in Spain, the United States, and Brazil. In this study, 22 of the 26 strains analyzed from blood donors and HIV-1+ individuals were HTLV-2b (84.6%) clustering with Amerindian references, while 4 HIV-1+ (15.4%) were HTLV-2a. HTLV-2a sequences were closely related to Brazilian references in contrast to the previous Argentinean IDU strain that clustered with Africans and Amerindians from North America. In summary, these findings show that HTLV-2b is the major strain circulating in an urban population of Argentina. HTLV-2a/b could have been introduced from endemic South American countries such as Brazil and because of contact with other populations such as IDUs from Europe despite its introduction due to the increasing internal migration of aborigines to large urban centers. Considering this results and recent data about the dissemination of HTLV-1 in residents of Buenos Aires city, new studies among non-at-risk groups for HTLV-1/2 infection should be performed. © Copyright 2012, Mary Ann Liebert, Inc. 2012.

La tortura en las Siete Partidas: la pena, la prueba y la majestad. Un análisis sobre la reinstauración del tormento en la legislación castellana del siglo XIII Panateri, Daniel Alberto Nadie de entre los historiadores del derecho, podría animarse a negar la presencia de fuentes romanas (en especial esa compilación tardía denominada Corpus Iuris Civilis) dentro de Partidas; con particular acento en el caso del Digesto. Por esto, en términos de su materialidad, lo que se presentará aquí será un trabajo de cotejo entre títulos específicos de las obras citadas y que refieren al tópico de la tortura. Por un lado, el título 18 del libro XLVIII del Digesto junto con el título 41 del libro IX del Codex. Del otro lado, el título 30 del libro VII de Partidas. Esta comparación buscará no tanto las equivalencias textuales (que son conscientemente obviadas por los redactores a pesar de conocer a la perfección los sistemas de citado) como el sentido último de introducir estos textos en el corpus legislativo castellano. En este sentido, lo que se buscará será plantear métodos posibles para sortear el problema de la intertextualidad en un mundo sin autores.; None of the historians of law woud dare to deny the presence of Roman sources –especially the late compilation called Corpus Iuris Civilis– in Partidas and specially the case of Digestum. Thus, in terms of its materiality, what will be presented here will be a comparison between specific titles of the works mentioned above which refer to the topic of torture. On the one hand, we will analyze the 18th title of the book XLVIII of Digestum in contrast with the 41st title of Book IX of Codex. On the other hand, we will study the 30th title of Book VII of Partidas. This comparison will not be specially focused on textual equivalences –which are consciously overlooked by the drafters despite their perfect knowlage of the quotation systems– but on the ultimate significance that entails the introduction of these texts in the Castilian legislative framework and, specially, the return of torture as a conclusive proof. In this regard, our objective will be to expound possible methods to deal with the problem of intertextuality in a world without authors.

Estructura productiva, actividad azucarera mercado de trabajo en Tucumán (1930-1970); Productive structure, activity related to sugar industry and the labor market in Tucuman (1930-1970) Osatinsky, Ariel En el período 1930-1970 la estructra productiva de Tucumán sufrió cambios de trascendencia, vinculados en general a las políticas económicas que desarrollaron los distintos gobiernos nacionales. El pasaje de una industrialización sustitutiva de importaciones trabajo intensiva a una capital intensiva con predominio de las empresas más eficientes y de mayor envergadura, implicó que tanto la actividad agrícola como el sector manufacturero de la provincia perdieran importancia. En particular, la actividad azucarera, que había crecido al amparo del Estado, tuvo que desenvolverse a partir de 1955 en un marco de crecientes políticas de desregulación, sufriendo a fines de los años 60 un profundo retroceso con el cierre de 11 de los 27 ingenios. Estas transformaciones ocasionaron importantes cambios en el mercado de trabajo. En ese sentido, el objeto de este artículo es examinar la relación que hubo entre las transformaciones económicas señaladas y los problemas de empleo que sufrió la población activa de la provincia, teniendo presente que a comienzos de la década de 1930 Tucumán tenía la menor tasa de desocupación del país, mientras que a fines de los ´60 sufría un notable deterioro laboral.; The productive structure of Tucumán underwent changes of great importance during the 1930-1970 period. The passage from a work-intensive industrialization based on the substitution of imports to a capital-intensive one, with predominance of the most efficient and larger companies, implied that both the agriculture activity and the manufacturing sector of the province lost importance. Since 1955, the sugar industry developed its activity within a frame of growing deregulation policies, which resulted in a deep deterioration by the end of the 1960's, with the closure of 11 out of 27 sugar refineries. The object of this paper is to examine the relation between the aforementioned economic transformations and the employment problems suffered by the economically active population in the province, taking into account that Tucumán had the lowest unemployment rate at the beginning of the 1930 decade, while it suffered a noticeable deterioration in labor market conditions by the end of the 1960's.

Depression storage and infiltration effects on overland flow depth-velocity-friction at desert conditions: Field plot results and model Rossi, María Julieta; Ares, Jorge Oscar Water infiltration and overland flow are relevant in considering water partition among plant life forms, the sustainability of vegetation and the design of sustainable hydrological models and management. In arid and semi-arid regions, these processes present characteristic trends imposed by the prevailing physical conditions of the upper soil as evolved under water-limited climate. A set of plot-scale field experiments at the semi-arid Patagonian Monte (Argentina) were performed in order to estimate the effect of depression storage areas and infiltration rates on depths, velocities and friction of overland flows. The micro-relief of undisturbed field plots was characterized at z-scale 1 mm through close-range stereo-photogrammetry and geo-statistical tools. The overland flow areas produced by controlled water inflows were video-recorded and the flow velocities were measured with image processing software. Antecedent and post-inflow moisture were measured, and texture, bulk density and physical properties of the upper soil were estimated based on soil core analyses. Field data were used to calibrate a physically-based, mass balanced, time explicit model of infiltration and overland flows. Modelling results reproduced the time series of observed flow areas, velocities and infiltration depths. Estimates of hydrodynamic parameters of overland flow (Reynolds-Froude numbers) are informed. To our knowledge, the study here presented is novel in combining several aspects that previous studies do not address simultaneously: (1) overland flow and infiltration parameters were obtained in undisturbed field conditions; (2) field measurements of overland flow movement were coupled to a detailed analysis of soil microtopography at 1 mm depth scale; (3) the effect of depression storage areas in infiltration rates and depth-velocity friction of overland flows is addressed. Relevance of the results to other similar desert areas is justified by the accompanying biogeography analysis of similarity of the environment where this study was performed with other desert areas of the world.

Kelp gulls attack Southern right whales: a conservation concern? Fazio, Ana; Bertellotti, Néstor Marcelo; Villanueva, María Cecilia Kelp gulls (Larus dominicanus) feed on pieces of skin and blubber they rip from Southern right whales’ (Eubalaena australis) backs in their breeding areas at Península Valdés, Argentina, producing injuries. This behavior has increased since the first record in 1972, and some authors have suggested that constant gull harassment could have a negative effect on right whale population. The main goal of this study is to assess the variables that most affect the gull attacks. We analyzed 5359 whale-watching sightings made during trips from Puerto Pirámides (42º34′S, 64º16′W) along the whale breeding seasons (June–December) 2005 to 2007. The most important factors affecting the attacks include the presence of a mother–calf pair, the time within the season, the distance to the coast and the wind velocity. There is also concern of possible transmission of infectious diseases in the attacks since increasing number of whales with different patterns of skin lesions have been observed.

Degradation of PsbO by the Deg Protease HhoA Is Thioredoxin Dependent Roberts, Irma; Tam Lam, Xuan; Miranda, Helder; Kieselbach, Thomas; Funk, Christiane The widely distributed members of the Deg/HtrA protease family play an important role in the proteolysis of misfolded and damaged proteins. Here we show that the Deg protease rHhoA is able to degrade PsbO, the extrinsic protein of the Photosystem II (PSII) oxygen-evolving complex in Synechocystis sp. PCC 6803 and in spinach. PsbO is known to be stable in its oxidized form, but after reduction by thioredoxin it became a substrate for recombinant HhoA (rHhoA). rHhoA cleaved reduced eukaryotic (specifically, spinach) PsbO at defined sites and created distinct PsbO fragments that were not further degraded. As for the corresponding prokaryotic substrate (reduced PsbO of Synechocystis sp. PCC 6803), no PsbO fragments were observed. Assembly to PSII protected PsbO from degradation. For Synechocystis sp. PCC 6803, our results show that HhoA, HhoB, and HtrA are localized in the periplasma and/or at the thylakoid membrane. In agreement with the idea that PsbO could be a physiological substrate for Deg proteases, part of the cellular fraction of the three Deg proteases of Synechocystis sp. PCC 6803 (HhoA, HhoB, and HtrA) was detected in the PSII-enriched membrane fraction.

Reconnection events in two-dimensional Hall magnetohydrodynamic turbulence Donato, Stella Maris; Servidio, S.; Dmitruk, Pablo Ariel; Carbone, Verónica Andrea; Shay, M.A.; Cassak, P.A.; Matthaeus, W.H. The statistical study of magnetic reconnection events in two-dimensional turbulence has been performed by comparing numerical simulations of magnetohydrodynamics (MHD) and Hall magnetohydrodynamics (HMHD). The analysis reveals that the Hall term plays an important role in turbulence, in which magnetic islands simultaneously reconnect in a complex way. In particular, an increase of the Hall parameter, the ratio of ion skin depth to system size, broadens the distribution of reconnection rates relative to the MHD case. Moreover, in HMHD the local geometry of the reconnection region changes, manifesting bifurcated current sheets and quadrupolar magnetic field structures in analogy to laminar studies, leading locally to faster reconnection processes in this case of reconnection embedded in turbulence. This study supports the idea that the global rate of energy dissipation is controlled by the large scale turbulence, but suggests that the distribution of the reconnection rates within the turbulent system is sensitive to the microphysics at the reconnection sites. © 2012 American Institute of Physics.

Effect of the support on the catalytic stability of Rh formulations for the water-gas shift reaction Cornaglia, Carolina Andrea; Múnera Agudelo, John Fernando; Cornaglia, Laura Maria; Lombardo, Eduardo Agustin; Ruiz, Patricio; Karelovic, Alejandro The stability of Rh(0.6)/La 2O 3 and Rh(0.6)/La 2O 3(27)·SiO 2 catalysts used in the water-gas shift reaction (WGSR) was studied. In order to understand the different behavior of the two formulations, XRD, Raman spectroscopy and operando-DRIFTS were employed. It was demonstrated that Rh/La 2O 3·SiO 2 showed a constant activity after 50 h on stream and that it was made up of La 2Si 2O 7 with very low crystallinity and SiO 2. On the other hand, Rh/La 2O 3 after use evolved to a mixture of oxycarbonates and lanthanum hydroxide evidenced by XRD and confirmed by Raman spectroscopy. This solid suffered a significant deactivation which was assigned to the formation of very small amounts of formate and carbonate residues. These residues disappeared after being burnt in air at 673 K and the initial catalytic activity was restored. The results obtained were useful to explain the reasons for the different stability of the two formulations and could have implications for the design of active catalysts used in the WGSR and in the processes in which it is involved.

PdAgAu alloy with high resistance to corrosion by H2S Braun, Fernando; Miller, James; Gellman, Andrew J; Tarditi, Ana Maria; Fleutot, Benoit; Kondratyuk, Petro; Cornaglia, Laura Maria PdAgAu alloy films were prepared on porous stainless steel supports by sequential electroless deposition. Two specific compositions, Pd83Ag2Au15 and Pd74Ag14Au12, were studied for their sulfur tolerance. The alloys and a reference Pd foil were exposed to 1000H2S/H2 at 623 K for periods of 3 and 30 h. The microstructure, morphology and bulk composition of both non-exposed and H2S-exposed samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). XRD and SEM analysis revealed time-dependent growth of a bulk Pd4S phase on the Pd foil during H2S exposure. In contrast, the PdAgAu ternary alloys displayed the same FCC structure before and after H2S exposure. In agreement with the XRD and SEM results, sulfur was not detected in the bulk of either ternary alloy samples by EDS, even after 30 h of H2S exposure. X-ray photoelectron spectroscopy (XPS) depth profiles were acquired for both PdAgAu alloys after 3 and 30 h of exposure to characterize sulfur contamination near their surfaces. Very low S 2p and S 2s XPS signals were observed at the top-surfaces of the PdAgAu alloys, and those signals disappeared before the etch depth reached ∼10 nm, even for samples exposed to H2S for 30 h. The depth profile analyses also revealed silver and gold segregation to the surface of the alloys; preferential location of Au on the alloys surface may be related to their resistance to bulk sulfide formation. In preliminary tests, a PdAgAu alloy membrane displayed higher initial H2 permeability than a similarly prepared pure Pd sample and, consistent with resistance to bulk sulfide formation, lower permeability loss in H2S than pure Pd.

Hf and Nd isotopes in Early Ordovician to Early Carboniferous granites as monitors of crustal growth in the Proto-Andean margin of Gondwana Dahlquist, Juan Andrés; Pankhusrt, Robert J.; Gaschnig, Richard M.; Rapela, Carlos Washington; Casquet, César Martín; Alasino, Pablo Horacio; Galindo, Carmen; Baldo, Edgardo Gaspar Agustín We report the first study integrating in situ U–Pb and Hf isotope data from magmatic zircon and whole-rock Sm–Nd isotope data for granitic rocks of the Sierras Pampeanas, Argentina, in order to evaluate the Palaeozoic growth of the proto-Andean margin of Gondwana. Early–Middle Ordovician granitic magmatism is by far the most voluminous of the Sierras Pampeanas and represents the most significant magmatic event. These calc-alkaline granitoids were intruded at an active continental margin. εHft values range from − 3.3 to − 14.7 and εNdt from − 3.3 to − 6.3 (t = 473 Ma), with average TDM Hf and TDM Nd ranging from 1.5 to 2.2 Ga and 1.4 to 1.7 Ga, respectively. Middle–Late Devonian magmatism occurred in the foreland, away from the orogenic front in the west, and included F-U-REE rich A-type granites. The Achala granite, the largest batholith in the Sierras Pampeanas, has εHft and εNdt values ranging from − 3.6 to − 5.8 and − 4.0 to − 6.5, respectively (t = 369 Ma). Small scattered Early Carboniferous A-type granite plutons were intruded in a dominantly extensional setting and have εHft and εNdt values ranging from − 6.7 to + 2.2 and − 0.5 to − 3.6, respectively (t = 341 Ma). The generation of Ordovician and Devonian magmas dominantly involved crustal reworking and stabilization rather than the formation of new continental crust by juvenile material accretion, whereas Carboniferous magmatism resulted in part from reworking of supracrustal material, but with variable addition of juvenile magmas.

Experimental results applying second order sliding mode control to a PEM fuel cell based system Kunusch, Cristian; Puleston, Pablo Federico; Mayosky, Miguel Angel; Fridman, Leonid A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. A Super Twisting controller is designed using a nonlinear model of a laboratory fuel cell test station, even a Lyapunov based stability discussion is included. Subsequently, the proposed control strategy is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, oxygen stoichiometry regulation and robustness against uncertainty.

Approaches to homozygosity mapping and exome sequencing for the identification of novel types of CDG Matthij, Gert; Rymen, Daisy; Bistue Millon, Maria Beatriz; Souche, Erika; Race, Valérie In the past decade, the identification of most genes involved in Congenital Disorders of Glycosylation (CDG) (type I) was achieved by a combination of biochemical, cell biological and glycobiological investigations. This has been truly successful for CDG-I, because the candidate genes could be selected on the basis of the homology of the synthetic pathway of the dolichol linked oligosaccharide in human and yeast. On the contrary, only a few CDG-II defects were elucidated, be it that some of the discoveries represent wonderful breakthroughs, like e.g, the identification of the COG defects. In general, many rare genetic defects have been identified by positional cloning. However, only a few types of CDG have effectively been elucidated by linkage analysis and so-called reverse genetics. The reason is that the families were relatively small and could—except for CDG-PMM2— not be pooled for analysis. Hence, a large number of CDG cases has long remained unsolved because the search for the culprit gene was very laborious, due to the heterogeneous phenotype and the myriad of candidate defects. This has changed when homozygosity mapping came of age, because it could be applied to small (consanguineous) families. Many novel CDG genes have been discovered in this way. But the best has yet to come: what we are currently witnessing, is an explosion of novel CDG defects, thanks to exome sequencing: seven novel types were published over a period of only two years. It is expected that exome sequencing will soon become a diagnostic tool, that will continuously uncover new facets of this fascinating group of diseases.

DNA damage kinetics and apoptosis in ivermectin-treated chinese hamster ovary cells Molinari, Gabriela Beatriz; Kujawski, Maciej; Scuto, Anna; Soloneski, Sonia Maria Elsa; Larramendy, Marcelo Luis A comet assay was used to analyze DNA damage kinetics in Chinese hamster ovary (CHO-K1) cells induced by antiparasitic ivermectin (IVM) and the IVM-containing technical formulation IvomecW (IVO; 1% IVM). Cells were treated with 50 mg ml–1 IVM and IVO for 80 min, washed and re-incubated in antiparasiticide-free medium for 0–24 h until assayed using the single-cell gel electrophoresis assay (SCGE). Cell viability remained unchanged up to 3 h of incubation. After 6 h of treatment, cell survival decreased up to 75% and 79% in IVM- and IVO-treated cultures, respectively, remaining unchanged within 12–24 h after treatment. For both anthelmintics, biphasic behavior in DNA damage occurred during the incubation time. A time-dependent increase of IVM- and IVO-induced DNA damage was observed within 0 to 3 h after pulse treatment, revealed by a progressive decrease of undamaged cells and an increase in slightly damaged and damaged cells. Finally, a time-dependent decrease in IVM- and IVO-induced DNA damage was revealed by a progressive decrease of slightly damaged cells and the absence of damaged cells simultaneously with an increase in the frequency of undamaged cells during the final 18 h of incubation. Flow cytometry analysis revealed that both compounds are able to induce a marked increase in early and late apoptosis. Based on our observations, we could conclude that the decrease in DNA lesions is mostly related to IVMinduced cytotoxicity rather than attributable to a repair process. Copyright © 2012 John Wiley & Sons, Ltd.

Differential expression of distinct soybean resistance genes interacting with Argentinean isolates of Diaporthe phaseolorum var. meridionalis Chiesa, Maria Amalia; Pioli, Rosanna Nora; Cambursano, Mariana Virginia; Morandi, Eligio Natalio Soybean Stem Canker (SSC), caused by Diaporthe phaseolorum var. meridionalis (Dpm), is an important disease of soybean in Argentina. There are five known dominant genes that confer resistance to SSC, Rdm1 to Rdm5. Particularly, Rdm2 was identified in cv. Tracy-M and then it was stabilized in the breeding line T2. The Rdm4 gene was first identified in cv. Hutcheson. More recently it was found that this gene was linked to the Rdm5 gene, defining the Rdm4-5 resistance region in Hutcheson. The objective of this work was to analyze the behaviour of the dominant Rdm2, Rdm4 and Rdm5 genes interacting with the CE109 and CE112 local physiological races of Dpm, in different susceptible backgrounds (genotypes RA702 and J77-339). Rdm4 and Rdm5 segregated phenotypically as completely dominant genes in the specific interactions with the CE109 and CE112 isolates, respectively, in both susceptible backgrounds. Similarly, Rdm2 segregated as expected for a complete dominant gene in the specific interaction with the CE109 isolate, in both susceptible backgrounds. However, when interacting with the CE112 isolate, the Rdm2 gene did not segregate as expected for a completely dominant gene, neither in RA702 nor in J77-339 susceptible background. The distorted segregation of the Rdm2 gene was due to incomplete penetrance. To the best of our knowledge this is the first report documenting changes in the degree of penetrance of a soybean resistance gene (Rdm2) depending upon the physiological race of Dpm which interacts with and the genetic background in which the Rdm gene is being expressed.

CD200-CD200R1 interaction contributes to neuroprotective effects of anandamide on experimentally induced inflammation Hernangómez, Miriam; Mestre, Leyre; Correa, Fernando Gabriel; Loría, Frida; Mecha, Miriam; Iñigo, Paula M.; Docagne, Fabian; Williams, Richard O.; Borrell, Jorge; Guaza, Carmen The endocannabinoid anandamide (AEA) is released by macrophages and microglia on pathological neuroinflammatory conditions such as multiple sclerosis (MS). CD200 is a membrane glycoprotein expressed in neurons that suppresses immune activity via its receptor (CD200R) mainly located in macrophages/microglia. CD200-CD200R interactions contribute to the brain immune privileged status. In this study, we show that AEA protects neurons from microglia-induced neurotoxicity via CD200-CD200R interaction. AEA increases the expression of CD200R1 in LPS/IFN-γ activated microglia through the activation of CB2 receptors. The neuroprotective effect of AEA disappears when microglial cells derive from CD200R1−/− mice. We also show that engagement of CD200R1 by CD200Fc decreased the production of the proinflammatory cytokines IL-1β and IL-6, but increased IL-10 in activated microglia. In the chronic phases of Theiler's virus-induced demyelinating disease (TMEV-IDD) the expression of CD200 and CD200R1 was reduced in the spinal cord. AEA-treated animals up-regulated the expression of CD200 and CD200R1, restoring levels found in sham animals together with increased expression of IL-10 and reduced expression of IL-1β and IL-6. Treated animals also improved their motor behavior. Because AEA up-regulated the expression of CD200R1 in microglia, but failed to enhance CD200 in neurons we suggest that AEA-induced up-regulation of CD200 in TMEV-IDD is likely due to IL-10 as this cytokine increases CD200 in neurons. Our findings provide a new mechanism of action of AEA to limit immune response in the inflamed brain.

Cisplatin inhibits testosterone synthesis by a mechanism that includes the action of reactive oxygen species (ROS) at the level of P450scc Mori Sequeiros, María de Las Mercedes; Acquier, Andrea Beatriz; Suárez, Guadalupe Verónica; Gómez, Natalia; Gorostizaga, Alejandra Beatriz; Mendez, Carlos Fernando; Paz, Cristina del Valle Cisplatin (Cs) is a chemotherapeutic agent able to generate reactive oxygen species (ROS) which are linked to several side effects of the drug. Even when it is known that Cs produces Leydig cell dysfunction, it is unknown whether this particular side effect is mediated by ROS. The aim of this study was to evaluate the in vitro effects of Cs on testosterone production and the participation of ROS in this effect. We demonstrate that Cs promotes the generation of ROS in a time-, and concentration-dependent fashion, not only in mouse testicular interstitial cells but also in MA-10 Leydig cells. Also, Cs inhibits testosterone synthesis in a concentration-dependent fashion (5–50 μM for 4 h) and to a similar extent, in cells exposed to human chorionic gondadotropin hormone (hCG), to an analog of the second messenger cAMP (8Br-cAMP) or to a freely diffusible cholesterol analog (22R-hydroxycholesterol). However, this treatment does not inhibit the conversion of pregnenolone to testosterone. These data suggest that Cs exerts its inhibitory action on testosterone synthesis by an action at the level of P450scc. We also demonstrated that an antioxidant impairs the inhibitory effect of Cs on the conversion of the cholesterol analog into pregnenolone and that Cs does not change the expression level of P450scc mRNA. Therefore, it is concluded that Cs inhibits testosterone synthesis by a mechanism that includes the inhibition of P450scc by ROS.