¿Liberales o proteccionistas?: Estrategias económicas contrapuestas en la cadena automotriz argentina en las décadas del 60 y 70.; ¿Liberals or protectionists?. Opposite economic strategies in Argentina automotive chain in the 60s and 70s Bil, Damián Andrés; Harari, Ianina; Sanz Cerbino, Gonzalo Sebastian Con el objetivo de comprender las estrategias de la clase capitalista en el país, proponemos aquí analizar la posición de los industriales del sector automotriz frente a la crisis orgánica de la sociedad argentina durante las décadas de 1960 y 1970. Es decir, estudiar las posturas asumidas por los empresarios y las corporaciones representativas de la actividad ante las diferentes coyunturas específicas de esos años, y en segundo término los conflictos dentro de la cadena asociados a esas circunstancias. Buscamos discutir la idea común en la historiografía, que sostiene que los capitales más concentrados defendieron un programa aperturista asociado a intereses extranjeros y de los sectores primarios, mostrando cómo los reclamos de las terminales automotrices de origen extranjero se inscriben en una estrategia que denominamos "liberal-desarrollista", pasada por alto en gran parte de los estudios sobre el particular.Utilizamos para alcanzar el objetivo información empresaria (Memorias y Balances contables, boletines), documentación de cámaras de industria, publicaciones periódicas especializadas, y aportes de otros investigadores.; In order to understand the strategies of the capitalist class in the country, we propose to analyze the position of automobile sector manufacturers to deal with the organic crisis of Argentine society during the 1960s and 1970s. In other words, we suggest studying the positions taken by businessmen and corporations in reponse to specific situations in those years. Then, we study the conflicts within the chain associated with those circumstances. We seek to discuss the common idea along historiography, which holds that the concentrated capital stood behind an open market program associated with foreign interests and primary sectors. We analyze how the demands of foreign automobile makers in Argentina are part of a “liberal - developmentlist” strategy, overlooked in most of the studies on the subject. To achieve the objective, we used business information (Reports and balance sheets, newsletters), documents of industry chambers, journals, and contributions from other researchers.

Abriendo la «caja negra» del aula de ciencias: un estudio sobre la relación entre las prácticas de enseñanza sobre el cuerpo humano y las capacidades de pensamiento que se promueven en los alumnos de séptimo grado; Opening the «black box» of the science classroom: A study on the relationship between teaching practices on the topic of the Human Body and the thinking skills promoted in 7th grade students Furman, Melina Gabriela; Luzuriaga, Mariana; Taylor, Inés; Anauati, María Victoria; Podestá, María Eugenia Comprender los bajos desempeños de los alumnos argentinos en las evaluaciones de ciencias implica abrir la «caja negra» del aula para analizar las prácticas de enseñanza. Se realizó un estudio cuanti-cualitativo en una muestra representativa de 36 cursos de séptimo grado (alumnos de entre 12 y 13 años) de 19 escuelas estatales de la ciudad de Buenos Aires. Se analizó el tiempo dedicado al área y los tiposde actividades propuestas por los docentes a partir de los cuadernos de clase de los alumnos y se evaluó a todos los estudiantes (574). Observamos que en promedio se dictan 1,75 horas de clase semanales de ciencias, frente a las 4 estipuladas, y que el 81 % de las actividades promueven capacidades de pensamiento deorden inferior. Más tiempo de enseñanza y de actividades de orden superior correlacionan positivamente con el rendimiento de los alumnos en la prueba (r = 0,66 p < 0,05 y r = 0,5 p < 0,05, respectivamente).; Explaining low student achievement in Science requires opening the «black box» of the classroom to understand teaching practices. This mixed methods study on science teaching was conducted in a representative sample of 36 7th grade classes (students between 12 and 13 years old) from 19 state schools in the City of Buenos Aires, Argentina. All students (n = 574) were evaluated to understand the relationship between teaching practices and learning outcomes. Using student workbooks, we found that teachers taught an average of 1.75 hours of science lessons per week, versus the 4 hours specified by local guidelines, and that 81% of teaching activities promote lower order thinking skills (such as recalling and reproducing facts). This is worrying as increasing teaching time and higher order activities correlate positively with student learning outcomes (r = 0.66 p < 0.05 and r = 0.5 p < 0.05 respectively).

Revisiting entanglement within the Bohmian approach to quantum mechanics Zander, Claudia; Plastino, Ángel Ricardo We revisit the concept of entanglement within the Bohmian approach to quantum mechanics. Inspired by Bohmian dynamics, we introduce two partial measures for the amount of entanglement corresponding to a pure state of a pair of quantum particles. One of these measures is associated with the statistical correlations exhibited by the joint probability density of the two Bohmian particles in configuration space. The other partial measure corresponds to the correlations associated with the phase of the joint wave function, and describes the non-separability of the Bohmian velocity field. The sum of these two components is equal to the total entanglement of the joint quantum state, as measured by the linear entropy of the single-particle reduced density matrix.

Detection of magnetic moment in thin films with a home-made vibrating sample magnetometer Jordán, D.; González Chávez, D.; Laura, D.; Leon Hilario, Ludwin Misael; Monteblanco, E.; Gutarra Espinoza, Abel; Aviles Felix, Luis Steven This paper explores the optimization of an array of pick-up coils in a home-made vibrating sample magnetometer for the detection of magnetic moment in thin films. Sensitivity function of a 4-coils Mallinson configuration was numerically studied for the determination of the physical dimensions that enhance the sensitivity of the magnetometer. By performing numerical simulations using the Biot-Savart law combined with the principle of reciprocity we were able to determine the maximum values of sensitivity and the influence of the separation of the coils on the sensitivity function. After the optimization of the pick-up coils, the vibrating sample magnetometer was able to detect the magnetic moment of a 100 nm-thickness Fe19Ni81 magnetic thin film along and perpendicular to the in-plane anisotropy easy axis. The implemented vibrating sample magnetometer is able to detect changes in the magnetic moment of ∼2 × 10-4 emu.

Brucella abortus traverses brain microvascular endothelial cells using infected monocytes as a Trojan horse Miraglia, Maria Cruz; Rodríguez, Ana María; Barrionuevo, Paula; Rodríguez, Julia; Kim, Kwang S.; Dennis, Vida A.; Delpino, María Victoria; Giambartolomei, Guillermo Hernan Neurobrucellosis is an inflammatory disease caused by the invasion of Brucella spp. to the central nervous system (CNS). The pathogenesis of the disease is not well characterized; however, for Brucella to gain access to the brain parenchyma, traversing of the blood-brain barrier (BBB) must take place. To understand the CNS determinants of the pathogenesis of B. abortus, we have used the in vitro BBB model of human brain microvascular endothelial cells (HBMEC) to study the interactions between B. abortus and brain endothelial cells. In this study, we showed that B. abortus is able to adhere and invade HBMEC which was dependent on microtubules, microfilaments, endosome acidification and de novo protein synthesis. After infection, B. abortus rapidly escapes the endosomal compartment of HBMEC and forms a replicative Brucella-containing vacuole that involves interactions with the endoplasmic reticulum. Despite the ability of B. abortus to invade and replicate in HBMEC, the bacterium was unable by itself to traverse HBMEC, but could traverse polarized HBMEC monolayers within infected monocytes. Importantly, infected monocytes that traversed the HBMEC monolayer were a bacterial source for de novo infection of glial cells. This is the first demonstration of the mechanism whereby B. abortus is able to traverse the BBB and infect cells of the CNS. These results may have important implications in our understanding of the pathogenesis of neurobrucellosis.

The interfacial electrostatic potential modulates the insertion of cell-penetrating peptides into lipid bilayers Via, Matías Alejandro; Klug, Joaquín; Wilke, Natalia; Mayorga, Luis Segundo; del Popolo, Mario Gabriel Cell-penetrating peptides (CPP) are short sequences of cationic amino-acids that show a surprising ability to traverse lipid bilayers. CPP are considered to be some of the most effective vectors to introduce membrane-impermeable cargos into cells, but the molecular basis of the membrane translocation mechanisms and its dependence on relevant membrane physicochemical properties have yet to be fully determined. In this paper we resort to Molecular Dynamics simulations and experiments to investigate how the electrostatic potential across the lipid/water interface affects the insertion of hydrophilic and amphipathic CPP into two-dimensional lipid structures. Simulations are used to quantify the effect of the transmembrane potential on the free-energy profile associated with the transfer of the CPP across a neutral lipid bilayer. It is found that the electrostatic bias has a relatively small effect on the binding of the peptides to the membrane surface, but that it significantly lowers the permeation barrier. A charge compensation mechanism, arising from the segregation of counter-ions while the peptide traverses the membrane, determines the shape and symmetry of the free-energy curves and underlines relevant mechanistic considerations. Langmuir monolayer experiments performed with a variety of amphiphiles model the incorporation of the CPP into the external membrane leaflet. It is shown that the dipole potential of the monolayer controls the extent of penetration of the CPP into the lipid aggregate, to a greater degree than its surface charge.

Biomechanical evidence suggests extensive eggshell thinning during incubation in the Sanagasta titanosaur dinosaurs Hechenleitner, Esteban Martín; Taborda, Jeremías Ramón Alejandro; Fiorelli, Lucas Ernesto; Grellet-Tinner, Gerald; Núñez Campero, Segundo Ricardo The reproduction of titanosaur dinosaurs is still a complex and debated topic. Their Late Cretaceous nesting sites are distributed worldwide and their eggs display substantial morphological variations according to the parent species. In contrast to the typical 1.3-2.0 mm thick shells common to eggs of most titanosaur species (e.g., those that nested in Auca Mahuevo, Tama, Toteşti or Boseong), the Cretaceous Sanagasta eggs of Argentina display an unusual shell thickness of up to 7.9 mm. Their oviposition was synchronous with a palaeogeothermal process, leading to the hypothesis that their extra thick eggshell was an adaptation to this particular nesting environment. Although this hypothesis has already been supported indirectly through several investigations, the mechanical implications of developing such thick shells and how this might have affected the success of hatching remains untested. Finite element analyses estimate that the breaking point of the thick-shelled Sanagasta eggs is 14-45 times higher than for other smaller and equally sized titanosaur eggs. The considerable energetic disadvantage for piping through these thick eggshells suggests that their dissolution during incubation would have been paramount for a successful hatching.

Negritud afroargentina en la literatura regionalista folklórica de Draghi Lucero. Esclavos y Mandingas en Las mil y una noches argentinas Morales, Orlando Gabriel Este artículo examina las representaciones de la negritud afroargentina en "Las mil y una noches argentinas" (Draghi Lucero, 1940), una obra referente y destacada de la literatura regionalista de inspiración folklórica de Cuyo, del período 1930-1940, que contribuyó a configurar una identidad cuyana. El trabajo contextualiza "Las mil y una noches argentinas" en la trayectoria de Juan Draghi Lucero en las disciplinas del folklore, la historia y la literatura, y pone en diálogo su obra literaria con el criollismo, el nacionalismo y regionalismo cultural de fines del siglo XIX y principios del XX. El análisis expone una narrativa que asume un mesticismo, un folklore y una cultura popular cuyana con énfasis en el aporte precolombino y español, excluyente del elemento africano. También que reproduce ideas comunes de intelectuales argentinos sobre la esclavitud y los africanos esclavizados. Respecto a esto, se identifican dos asociaciones que concatenadas contribuyen a la premisa de la desaparición de los negros argentinos en el siglo XIX: una, entre esclavitud y negros africanos, situados éstos en la sociedad colonial y concebidos como sujetos pasivos beneficiados por relaciones recíprocas de fidelidad/solidaridad con los amos; y otra, menos evidente y más alegórica, entre el fin de la esclavitud o la obtención de la libertad de los esclavos y la desaparición física de los negros. Asimismo, la narrativa apela a estereotipos sociales como la identificación de los negros argentinos con el federalismo y mitos tradicionales de la cultura occidental como la representación del diablo como un hombre negro.; This article examines the representations of Afro-Argentinean negritude in Las mil y una noches argentinas (Draghi Lucero, 1940), a reference and outstanding work of Cuyo's folkloric-inspired regionalist literature, from the 1930-1940 period, which contributed to postulate an Cuyana identity cuyana. The work contextualizes Las mil y una noches argentinas in the career of Juan Draghi Lucero in the disciplines of folklore, history and literature, and puts his literary work in dialogue with the criollismo and nationalism and cultural regionalism of the late nineteenth century and early twentieth. The analysis exposes a narrative that assumes a mesticismo, a folklore and a Cuyo popular culture with emphasis on the pre-Columbian and Spanish contribution and excluding the African element. It also reproduces common ideas of Argentine intellectuals about slavery and enslaved Africans. Regarding this, two associations are identified that concatenated contribute to the premise of the disappearance of Argentine blacks in the nineteenth century: one, between slavery and African blacks, located in colonial society and conceived as passive subjects benefited by reciprocal relations of fidelity / solidarity with the masters; and another, less evident and more allegorical, between the end of slavery or the obtaining of the freedom of the slaves and the physical disappearance of the blacks. Likewise, the narrative appeals to social stereotypes such as the identification of Argentine blacks with federalism and traditional myths of Western culture as the representation of the Devil as a dark man.

A New Species Endemic to the Atacama Region of Chile: Eryngium crassifolium (Apiaceae, Saniculoideae) Padin, Ariana Lucía; Calviño, Carolina Isabel This study reports a new species of Eryngium (Apiaceae, Saniculoideae) from the desert scrubs, in the south of the III Atacama Region, Chile. This new species is singular within the genus by its succulency in vegetative and reproductive leaves.Weprovide a morphological description, the geographical distribution, habitat, informal IUCN conservation status assessment, and illustrations of this new species. We also describe the anatomical and morphological differences between Eryngium crassifolium and E. macracanthum, its most similar species.

Obstáculos de aprendizaje en niños de 10-12 años sobre el tema sistema circulatorio humano: una propuesta teórica en base a evidencias; Learning obstacles in children aged 10-12 years on the subject of human circulatory system: a theoretical proposal based on evidence Galagovsky, Lydia Raquel; Edelsztein, Valeria Carolina Este trabajo se centra en la investigación sobre posibles orígenes para los errores de aprendizaje detectados en estudiantes de 5to y 6to grado de escuela primaria (10-12 años), frente al tema sistema circulatorio humano. A partir de evidencias que provienen de las respuestas de los niños frente a un cuestionario, se presenta una propuesta de procesos cognitivos involucrados en el aprendizaje en función del marco teórico del Sistema de Procesamiento de la Información. Finalmente, se propone una categorización de Obstáculos Epistemológicos de Aprendizaje (OEA) que se derivan del análisis de casos de aprendizajes erróneos sobre el tema en cuestión. La importancia de detectar tempranamente dificultades de aprendizaje sería llegar a evitar que se afiancen los errores generados durante el procesamiento inicial de la información que se debe aprender.; This paper focuses on the investigation of possible origins of learning errors detected in fifth and sixth grade primary school students (10-12 years), in relation to the human circulatory system. Based on the evidence that comes from the analysis of the children’s responses to a questionnaire, a theoretical proposal about cognitive processes involved in acquisition of new learning is presented. These cognitive processes are based on the framework of Information Processing Theory. A categorization of Epistemological Learning Obstacles (ELO) is also presented based on the analysis of cases of learning errors. Early detection of learning obstacles has an impact in avoiding the fixation of mistakes that could have appeared during initial stages of the learning process.

Hormones and monensin use to improve pregnancy rates in grazing lactating beef cows in the semiarid region of Argentina Reineri, Pablo Sebastian; Piccardi, Mónica Belén; Arroquy, Jose Ignacio; Fumagalli, Arnaldo Enrique; Coria, Maria Sumampa; Hernandez, Olegario; Bo, Gabriel Amilcar; Palma, Gustavo Adolfo The objectives of this study were 1) to determine the effect of monensin treatment, alone or combined with a hormonal estrus synchronization treatment, on the pregnancy rate of lactating beef cows, and 2) to evaluate the effect of monensin capsule administration on ruminal metabolism in steers. In experiment 1, ninety-four cows were selected from a 300 cow herd. The experimental design used was a 2 × 2 factorial with the administration of monensin capsule as first factor (M1 = with monensin vs. M0 = without monensin) and hormonal treatment as second factor (H1 = with hormonal treatment vs. H0 = no hormonal treatment). Thirty-eight days before the beginning of the breeding season, cows were randomly assigned to the first factor, and thirty days later to the second factor, resulting in four treatments: M1H0, M1H1, M0H0 and M0H1. Cow were exposed to bull (bull/cow ratio 1:20) from day 0 (day 0 = start of the breeding season and 38 days after monensin capsule administration) to day 50. Pregnancy diagnosis was performed at 30, 60 and 80 days after start breeding season by ultrasonography. In experiment 2, eight ruminally cannulated crossbred beef steers were randomly assigned to two treatments (M1 and M0). To determine proportion of volatile fatty acids (VFA), ruminal fluid samples were taken on days 0, 40 and 77 of the experimental period, at 0, 4 and 12 h after grazing. In experiment 1, treatments whit monensin did not improve pregnancy rate (P = 0.95), however, hormonal treatment resulted in grater pregnancy rates (P = 0.03). In experiment 2, the proportion of VFA in ruminal fluid of steers was significantly different between treatments. The highest proportion of propionate was found in ruminal fluid from M1 treatment at 12 h after grazing (P = 0.04). In conclusion, the treatment with monensin increased the proportion of propionate. The result might suggest that energy balance was improved in steers, without improvement in cow's pregnancy rates. Treatment with monensin alone did not improve pregnancy rate, nor did treatment with monensin enhance the pregnancy rate when a hormonal synchronisation treatment was given. Nevertheless, the use of a hormonal treatment increased pregnancy rate, suggesting that it could be used as a suitable tool to enhance the productivity in cows with marginal body condition score.

PRELIMINARY ANALYSIS OF THE HEMAGGLUTINATING ACTIVITY OF SEED EXTRACTS OF THE AMARANTH GENUS Dandeu, Leonardo Néstor Rubén; Repollo, Rodolfo; Oyhenart, Jorge; Ramirez, Maria Rosana In this study, seed extracts of cultivated Amaranthus species were tested for haemagglutinating activity. The extracts were prepared from the seeds of 7 Amaranthus cultivars and analyzed against samples from human, rat and dog erythrocytes. To detect haemoagglutination, 5% suspensions of human blood samples of the types A, B and O were prepared. The presence of polyphenols and saponins were determined in the extracts, yielding positive results for polyphenolics compounds. In order to characterize the proteins present in the amaranth extracts, the protein gel electrophoresis technique was applied. All extracts analyzed showed protein activity, and similar protein profile. The extracts reacted strongly with red blood cells (RBCs) from human ABO blood groups. It also reacted with rat and dog RBCs. The hemagglutinating activity was exhibited by the all extracts and the precipitated lectins from all species tested, however, hemolytic activity was not observed. The results obtained from the Amaranthus extracts indicate that it is non-specific for glycosylated antigens of the ABO system. The findings provide essential information for their use as potential hemoclasification reagents in the immunohematology laboratory.

Captadores solares; Solar captors Sola, Mariela Edith; Terny, Cintia Soledad; Di Pratula, Pablo Emmanuel; Cardillo, Evangelina Cinthia; Frechero, Marisa Alejandra En este trabajo se ha diseñado un material innovador que permite la transformación de la luz solar en energía calórica con alta eficiencia, consiguiendo además, cumplir un doble propósito: reaprovechar desechos industriales (parabrisas de automotores y cenizas) y contribuir al cuidado del medioambiente mediante el desarrollo de un nuevo método de generación de “energía verde”. Los nanocompositos constituidos por nanopartículas de Ag ancladas en una matriz vítrea, se sintetizaron utilizando una celda de estado sólido formada por electrolitos cristalinos y amorfos. Los materiales obtenidos se caracterizaron mediante técnicas de espectroscopia UV-Vis e Impedancia. El aumento en la permitividad da lugar a una mejora notable en el proceso de transporte de calor (nanopartícula-matriz) incrementando la funcionalidad del material nanocompuesto diseñado para la “cosecha de energía” (luz solar).; In this paper, it has been designed an innovative material that allows the transformation of sunlight into heat energy with high efficiency and it fulfills a dual purpose: to reuse industrial wastes (motor vehicles’ windshield and heat systems’ ashes) and to contribute to environment care by developing of a new method of "green energy" generation. The nanocomposites constituted by Ag nanoparticles anchored in a vitreous matrix, were synthesized using a solid state cell formed by crystalline and amorphous electrolytes. The materials were characterized by UV-Vis and impedance spectroscopy techniques. The increase observed in their permittivity results in a significant improvement in the heat transport process (nano-particle/glassy matrix) which provokes an improvement in the nano-composite material functionality for "energy harvesting" (sunlight).

Heterogeneous SoC-based acceleration of MPEG-7 compliance image retrieval process Molina, Romina Micaela; Dondo Gazzano, Julio Daniel; Rincon, Fernando; Gil Costa, Graciela Verónica; Barba, Jesus; Petrino, Ricardo; Lopez, Juan Carlos With the growing amount of multimedial content over the internet and broadcast systems, mechanisms for efficient information organization, manipulation and transmission are becoming indispensable. Optimization of the multimedia search and retrieval processes is nowadays an important area of development due to the difficulty to browse, filter and manage that big amount of data. The adoption of the MPEG-7 standard has a significant importance to simplify the image retrieval process. However, performance issues are still relevant when the retrieval must be accomplished in real time. This work presents an innovative and efficient approach of a Content-Based Retrieval Process using metric spaces implemented in heterogeneous resources according to the demand of computational power. Several implementations were made and comparative results are shown evidencing the benefits of the proposed approach.

Aporte a la cronología de chenques tardíos del Lago Salitroso (Santa Cruz, Argentina); Contribution to the chronology of late Chenques from Lake Salitroso (Santa Cruz, Argentina) Garcia Guraieb, Solana; Goñi, Rafael Agustín; Guichon, Rocio Se presentan dos nuevos fechados radiocarbónicos obtenidos en uno de los chenques tardíos (ca. 800-350 AP) del lago Salitroso (SAC) y sus implicaciones para las discusiones vigentes sobre prácticas mortuorias y cuestiones demográficas en el área. Se trata de SAC 1-2, un chenque primario múltiple, compuesto por un adulto femenino y 5 individuos infantiles. Dos fechados anteriores lo situaban en el orden de ca. 450 años AP. Actualmente, se fecharon dos subadultos hallados juntos en la base del entierro, cuya posición sugería su inhumación contemporánea. Mientras uno de los individuos mantuvo el orden de los ca. 400-500 años AP (487 ± 23 AP), el segundo presenta una fecha (709 ± 30 AP) que se aleja más de 200 años radiocarbónicos del anterior. Esta situación genera, nuevas preguntas sobre las prácticas mortuorias y la manera en que ocurre la reutilización de las estructuras de entierro. Además, tiene implicaciones para ideas previas sobre la recurrencia de episodios de simultaneidad de muerte de subadultos de diversas edades como explicación posible para las “anomalías” identificadas en el perfil de mortalidad de los chenques tardíos. Este caso alerta sobre la necesidad de refinar aún más el detalle de la cronología de los entierros del lago Salitroso.; In this article, two new radiocarbon dates from a late chenque (ca. 800-350 AP) at Lake Salitroso (SAC) are presented. These dates have implications for current discussions concerning mortuary practices and demography in the region. The case discussed is chenque SAC 1-2, a multiple individual, primary burial, containing one female adult and 5 infants. Two prior radiocarbon dates date this burial to ca. 450 BP. The two new radiocarbon dates were from two sub-adults placed next to each other at the base of the burial. Their positions suggest contemporaneous inhumation. Yet, while the date from one of the individuals (487 ± 23 BP) was within the same chronological range of ca. 400-500 BP, the other individual yielded a date –709 ± 30 AP– set approximately 200 years earlier. This chronological discrepancy raises new questions concerning mortuary practices and the way in which burial structures were reused in the region. It also has implications for existing hypotheses regarding the reoccurrence of mortality events that affected coevally sub-adults of different ages. This has been posed as a possible explanation for the abnormal pattern observed in the mortality profile of the late chenques. Our case-study warns us on the need to further refine the chronology of human burials from Lake Salitroso.

Extracting chemical information from high-resolution Kβ X-ray emission spectroscopy Limandri, Silvina Paola; Robledo, José Ignacio; Tirao, German Alfredo High-resolution X-ray emission spectroscopy allows studying the chemical environment of a wide variety of materials. Chemical information can be obtained by fitting the X-ray spectra and observing the behavior of some spectral features. Spectral changes can also be quantified by means of statistical parameters calculated by considering the spectrum as a probability distribution. Another possibility is to perform statistical multivariate analysis, such as principal component analysis. In this work the performance of these procedures for extracting chemical information in X-ray emission spectroscopy spectra for mixtures of Mn2+ and Mn4+ oxides are studied. A detail analysis of the parameters obtained, as well as the associated uncertainties is shown. The methodologies are also applied for Mn oxidation state characterization of double perovskite oxides Ba1+xLa1−xMnSbO6 (with 0 ≤ x ≤ 0.7). The results show that statistical parameters and multivariate analysis are the most suitable for the analysis of this kind of spectra.

Programming of the reproductive axis by hormonal and genetic manipulation in mice Rulli, Susana Beatriz; Cambiasso, Maria Julia; Ratner, Laura Daniela In mammals, the reproductive function is controlled by the hypothalamic-pituitary-gonadal axis. During development, mechanisms mediated by gonadal steroids exert an imprinting at the hypothalamic-pituitary level, by establishing sexual differences in the circuits that control male and female reproduction. In rodents, the testicular production of androgens increases drastically during the fetal/neonatal stage. This process is essential for the masculinization of the reproductive tract, genitals and brain. The conversion of androgens to estrogens in the brain is crucial for the male sexual differentiation and behavior. Conversely, feminization of the brain occurs in the absence of high levels of gonadal steroids during the perinatal period in females. Potential genetic contribution to the differentiation of brain cells through direct effects of genes located on sex chromosomes is also relevant. In this review, we will focus on the phenotypic alterations that occur on the hypothalamic-pituitary-gonadal axis of transgenic mice with persistently elevated expression of the human chorionic gonadotropin hormone (hCG). Excess of endogenously synthesized gonadal steroids due to a constant hCG stimulation is able to disrupt the developmental programming of the hypothalamic-pituitary axis in both transgenic males and females. Locally produced estrogens by the hypothalamic aromatase might play a key role in the phenotype of these mice. The 'four core genotypes' mouse model demonstrated a potential influence of sex chromosome genes in brain masculinization before critical periods of sex differentiation. Thus, hormonal and genetic factors interact to regulate the local production of the neurosteroids necessary for the programming of the male and female reproductive function.

Engineering a bifunctional copper site in the cupredoxin fold by loop-directed mutagenesis Espinoza Cara, Andrés Matías; Zitare, Ulises Alejandro; Álvarez Paggi, Damián Jorge; Klinke, Sebastian; Otero, Lisandro Horacio; Murgida, Daniel Horacio; Vila, Alejandro Jose Copper sites in proteins are designed to perform either electron transfer or redox catalysis. Type 1 and CuA sites are electron transfer hubs bound to a rigid protein fold that prevents binding of exogenous ligands and side reactions. Here we report the engineering of two Type 1 sites by loop-directed mutagenesis within a CuA scaffold with unique electronic structures and functional features. A copper-thioether axial bond shorter than the copper-thiolate bond is responsible for the electronic structure features, in contrast to all other natural or chimeric sites where the copper thiolate bond is short. These sites display highly unusual features, such as: (1) a high reduction potential despite a strong interaction with the axial ligand, which we attribute to changes in the hydrogen bond network and (2) the ability to bind exogenous ligands such as imidazole and azide. This strategy widens the possibility of using natural protein scaffolds with functional features not present in nature.

Critical frequencies of the ionospheric F1 and F2 layers during the last four solar cycles: Sunspot group type dependencies Yiğit, Erdal; Kilcik, Ali; Elias, Ana Georgina; Dönmez, Burçin; Ozguc, Atila; Yurchshyn, Vasyl; Rozelot, Jean Pierre The long term solar activity dependencies of ionospheric F1 and F2 regions’ critical frequencies (f0F1 and f0F2) are analyzed for the last four solar cycles (1976–2015). We show that the ionospheric F1 and F2 regions have different solar activity dependencies in terms of the sunspot group (SG) numbers: F1 region critical frequency (f0F1) peaks at the same time with the small SG numbers, while the f0F2 reaches its maximum at the same time with the large SG numbers, especially during the solar cycle 23. The observed differences in the sensitivity of ionospheric critical frequencies to sunspot group (SG) numbers provide a new insight into the solar activity effects on the ionosphere and space weather. While the F1 layer is influenced by the slow solar wind, which is largely associated with small SGs, the ionospheric F2 layer is more sensitive to Coronal Mass Ejections (CMEs) and fast solar winds, which are mainly produced by large SGs and coronal holes. The SG numbers maximize during of peak of the solar cycle and the number of coronal holes peaks during the sunspot declining phase. During solar minimum there are relatively less large SGs, hence reduced CME and flare activity. These results provide a new perspective for assessing how the different regions of the ionosphere respond to space weather effects.

Determination and Analysis of Residual Stresses Induced by High Speed Milling Using a Micro-indent Method Vottero, S.; Diaz, Felipe Victor; Mammana, Claudio Alejandro; Guidobono, A. The purpose of this work is to determine and analyze residual stress normal components and anisotropy degrees introduced by high-speed milling in specimens of AA 6082-T6 and AA 7075-T6 aluminum alloys. At each machined sample, the climb and conventional cutting zones were evaluated and compared. This paper includes a comprehensive study of thermal and mechanical effects associated with the residual stress introduction. For normal components determination, an optimized micro-indent method was used. Each measurement sequence from this approach was performed using a high accuracy measuring machine and classified according to thermal deviations measured. The residual displacements were determined with an absolute error down to ±300 nm. The normal components analysis allowed to infer the strong influence of the rolling process previous to high-speed milling and besides, the stress levels associated with thermal effects (higher in AA 7075-T6). Finally, the lower residual stress anisotropy degrees in both materials observed in the conventional cutting zone would indicate more homogenous local plastic stretching in this region for all planar directions.