Mean Atomic Number Quantitative Assessment in Backscattered Electron Imaging Sanchez, Eloy Sebastian; Torres Deluigi, María del Rosario; Castellano, Gustavo Eugenio A method for obtaining quantitative mean atomic number images in a scanning electron microscope for different kinds of samples has been developed. The backscattered electron signal is monotonically increasing with the mean atomic number Z, and accordingly Z can be given as a function of the image gray levels. From results obtained from Monte Carlo simulations, an exponential function is fitted to convert the backscattered registered gray levels into a Z image map. Once this fitting was performed, the reproducibility of the Z determination was checked through the acquisition of backscattered electron images from metal and mineral standards. The developed method can be applied to any unknown sample, always controlling the experimental conditions, as shown here for a thin section of a rock in which several unknown mineral phases are present; the results obtained herein are compared to quantitative assessments performed with X-ray spectra from each mineral phase.

Algunas dimensiones de la relación entre el capital y el trabajo en un enclave petrolero. El caso de Yacimientos Petrolíferos Fiscales en Argentina; Some Dimensions in the Relationship between capital and labor in an oil enclave. The Case of Yacimientos Petrolíferos Fiscales in Argentina Capogrossi, María Lorena Este artículo es parte de una investigación histórico-antropológica mayor que indaga acerca de las particularidades de la relación entre la empresa estatal Yacimientos Petrolíferos Fiscales y sus trabajadores. Aquí se abordarán algunas dimensiones de la misma en una "formación económica de enclave" constituida al Norte de la provincia de Salta, Argentina. El objetivo de este trabajo es analizar las características principales del sistema de dominación que la empresa estatal Yacimientos Petrolíferos Fiscales pone en marcha en sus campamentos petroleros a la largo del tiempo, encontrándose una yuxtaposición entre la esfera de producción y reproducción de los trabajadores. Específicamente se estudia la configuración de esa relación en Campamento Vespucio, localidad que adquirió su fisonomía a partir de la radicación de la empresa petrolera estatal en la región.; This article is part of a major historical-anthropological research project investigating particularities of the relationship between the state oil enterprise Yacimientos Petrolíferos Fiscales and its workers. Some dimensions of this relationship will be approached in an “economical enclave formation” set up in the north of the province of Salta, Argentina. The objective of this work is to analyze the main characteristics of the system of domination that the state company Yacimientos Petrolíferos Fiscales has put in action in its oil camps over time, finding a juxtaposition between the sphere of production and reproduction of the workers. Specifically, configuration of this relationship is studied at the Vespuccio Camp, a locality that acquired its physiognomy based on the settling of the state oil company in the region.

Análisis de las características morfológicas de las envolventes edilicias y del entorno urbano desde la perspectiva de la iluminación natural; Morphological analysis of building envelopes and urban environment characteristics from the perspective of natural lighting Villalba, Ayelén María; Pattini, Andrea Elvira; Corica, Maria Lorena El confort visual y los ahorros energéticos resultan de la adecuada planificación e la iluminación natural de un espacio. Como primera medida para alcanzarlos se debe conocer la posibilidad de acceso a la radiación solar en el rango visible de las fachadas. Este trabajo desarrolla un análisis morfológico-descriptivo de las variables urbanas, edilicias, de componentes de paso y de elementos de control solar que determinan el acceso de la radiación solar visible a un espacio interior, contemplando variables de carácter regional. Sus objetivos fundamentales son: (a) determinar las características morfológicas, urbanas y edilicias, que influyen en el acceso a la radiación solar visible de una fachada frontal; y (b) establecer un diagnóstico sobre los elementos de control solar encontrados en las fachadas frontales de los casos reales del área analizada. En el presente trabajo se determina la importancia del estudio en detalle de la fachada frontal de un edificio, dado que el 75% de los edificios analizados tienen su eje mayor dispuesto de modo perpendicular a la fachada frontal, el 90% no tiene retiros laterales y el 95% tiene una disposición edilicia en bloque. Del mismo modo demuestra que no existe una relación entre el empleo de las aberturas y sus elementos de control solar asociado con el clima luminoso regional.; Visual comfort and energy savings are results of the proper daylighting planning of spaces. As a first step to achieve these objectives we should be aware of the possibility of solar radiation access in the visible range of facades. This paper develops a descriptive morphological analysis of the urban, building, pass through component, and solar control system variables that determine access to visible radiation of a facade, considering regional variables. Its main objectives are: (a) to determine urban and building morphological caracteristics that affect access to visible solar radiation of front façades; and (b) to establish a diagnosis about the current state of these elements on front facades in the analyzed areas. This research work determines the importance of a detailed study of the front facade of buildings, given that 75% of the buildings analyzed have their central axis disposed perpendicularly to the front facade, 90% have no side retreats and 95% have a block building disposition. Likewise, it indicates that that there is no relationship between the use of openings and the solar control elements according to the regional clear sky climate.

Offspring production in response to host exposure times in diachasmimorpha longicaudata (hymenoptera: braconidae), reared on the genetic sexing strain vienna 8 of ceratitis capitata (diptera: tephritidae) Suárez, Lorena; Van Nieuwenhove, Guido Alejandro; Murúa Bruna, Albérico Fernando; Bezdjian, Laura Patricia; Schliserman, Pablo; Lara,Natalia; Escobar, Jorge; Ovruski Alderete, Sergio Marcelo The objective of the present study was to assess the effect of different times of exposure to the host on parasitoid emergence rate, parasitoid progeny sex ratio, and on host mortality, as a step toward the development of an efficient mass-rearing system for the braconid Diachasmimorpha longicaudata (Ashmead) on larvae of the VIENNA 8 Temperature Sensitive Lethal Ceratitis capitata (Wiedemann) strain. The role of host-rearing substrate cues in stimulating the host-searching behavior of parasitoid females was also evaluated. Three exposure times (40, 60, and 120 min) were tested. One hundred 7 d-old host larvae were exposed to 25 female parasitoids per treatment. Larvae mixed with wheat-based rearing medium and larvae without medium were used in each test. A second set of treatments with the same method described above was conducted using late third-instars of the C. capitata wild-type strain. These experiments were carried out to assess the quality of the larvae of VIENNA 8 strain in producing D. longicaudata adults by comparing them with the larvae of the wild-type strain. Results indicated that the use of larvae of VIENNA 8 strain on their rearing diet at 40 min exposure time significantly increased overall parasitoid offspring production and decreased the host mortality level. Nevertheless, parasitoid emergence recorded from VIENNA 8 strain was notably lower than that recorded from the wild-type strain. Low parasitoid emergence levels and the prevalence of male-biased progeny recorded in all assays are obstacles to development of a parasitoid mass-rearing system using larvae of VIENNA 8 strain as host. Additional studies focusing on host exposure to parasitoids are needed to verify the effect of host larval quality on the production of D. longicaudata.

Explotación de materias primas líticas en el sector sur de la ría Deseado: Análisis de núcleos procedentes de Bahía del Oso Marino (Patagonia Argentina); Exploitation of lithic raw materials in the south of river Deseado: core analysis from Bahía del Oso Marino, Patagonia Argentina Ambrustolo, Pablo En este trabajo se explora la existencia de variación en las estrategias de explotación de materias primas líticas en el subsector Bahía del Oso Marino, ubicado en el sur de la ría Deseado. El estudio fue realizado sobre núcleos recuperados en sitios superficiales y estratigráficos. Se tuvieron en cuenta las diferencias registradas en relación con las técnicas de reducción de dichos núcleos y su ubicación respecto de las potenciales fuentes de aprovisionamiento lítico. Los resultados obtenidos sugieren la existencia de variabilidad en las estrategias de explotación de los recursos líticos en el sector sur de la ría Deseado. Esto se traduce, por ejemplo, en el registro de evidencias de la puesta en práctica de estrategias de economía de algunas materias primas que estaría vinculada con las características que presentan la disponibilidad de materias primas líticas aptas para la talla en el sector. Se discute la influencia de dicha variación en relación con los rangos de movilidad y las estrategias de aprovisionamiento lítico empleadas por los grupos cazadores recolectores que ocuparon el sur de la ría Deseado durante el Holoceno medio y tardío.; This paper explores the existence of variation in lithic raw materials exploitation strategies in Bahía del Oso Marino, located south of the river Deseado. The study was conducted on cores collected from surface and stratigraphic sites; it took into account differences in reduction techniques and distances to potential sources of lithic procurement. The results suggest the existence of variability in the strategies of lithic resource exploitation in the southern sector of the river Deseado. Among other significant factors are the characteristics of available lithic raw materials sources in this space, which is seen in the raw materials economic strategies adopted. The influence of such variation in relation to the range of mobility and lithic procurement strategies used by hunter gatherers who occupied the area south of the river Deseado during the middle and late Holocene is discussed.

Short and long-term effects of endosulfan, cypermethrin, spinosad, and methoxyfenozide on adults of chrysoperla externa (Neuroptera: Chrysopidae) Rimoldi, Federico; Schneider, Marcela Inés; Ronco, Alicia Estela The susceptibility assessment of natural enemies to pesticides is relevant before the use of selective pesticides and biological control agents within the framework of integrated pest management programs. Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) is a predator considered a potential biocontrol agent of agricultural pests in the Neothropical Region. The aim of this study was to evaluate the short and long-term effects of two broad spectrum insecticides (Cypermethrin and endosulfan) and two biorational (spinosad and methoxyfenozide) registered in Argentina on young C. externa adults under laboratory conditions by ingestion through drinking water. The assessed end-points were: survivorship during preoviposition period, preoviposition time, fecundity and fertility of females, and survivorship of the progeny. Total survivorship of adults was adversely affected only by Cypermethrin that reduced the survivorship of adults irrespective of sex. Although endosulfan did not induce significant total mortality, it reduced the survivorship of females. All tested insecticides delayed the reproductive maturity of adults. Cypermethrin, endosulfan, and spinosad reduced the fecundity of females. Fertility was affected only by spinosad. Methoxyfenozide was the insecticide inducing the lowest effects on reproductive parameters. No effects were observed on the survival of progeny with any of the tested compounds. In accordance with the International Organization for Biological Control and Noxious Animals and Plants guidelines the insecticides were classified according to its lethal effects in the following toxicity classes: methoxyfenozide, spinosad, and endosulfan, class 1 (innocuous); Cypermethrin, class 2 (moderately toxic). However, if sublethal effects are taken into account, spinosad and endosulfan should not be considered innocuous. © 2012 Entomological Society of America.

Efficacy of Cloprostenol or Aglepristone at 21-22 and 35-38 Days of Gestation for Pregnancy Termination in Queens García Mitacek, María Carla; Stornelli, María Cecilia; Praderio, Romina Gisele; Stornelli, María Alejandra; de la Sota, Rodolfo Luzbel Contents: The objective of this study was to evaluate the efficacy of cloprostenol (CLO) or aglepristone (ALI) for pregnancy termination in queens at 21-22 and 35-38 days of gestation. Two experiments (EXP) were carried out to accomplish this aim. Thirty-seven 12- to 14-month-old mixed breed queens were used in a randomized design. At oestrus, queens were housed for mating with a tom, and pregnancy was confirmed by transabdominal ultrasonographic examination (US). On days 21-22 of pregnancy (EXP1) or 35-38 of pregnancy (EXP2), queens were divided into three groups (G). Queens in G1 received ALI (10 mg/kg, sc; EXP1, n = 6; EXP2, n = 6) on two consecutive days. Queens in G2 received CLO (5 μg/kg, sc; EXP1, n = 6; EXP2 = 7) on three consecutive days. Queens in G3 received 1 ml of saline solution (PLA, sc; EXP1, n = 6; EXP2 = 6). After treatment, females were monitored daily by US during for 10 days and weekly until the end of gestation. In EXP1, pregnancy was terminated in (6/6, 100%), (0/6, 0%) and (0/6, 0%), for the ALI, CLO and PLA groups, respectively (p < 0.001). In EXP2, pregnancy was terminated in (6/6, 100%), (1/7, 14%) and (0/6, 0%) for the ALI, CLO and PLA groups, respectively (p < 0.001). In both EXP, after CLO administration, animals vomited and were depressed for 30 min; but no side effects were observed in the animals in the ALI group. In conclusion, the results from this study indicate that three injections of CLO are not effective, but two injections of ALI are effective to induce abortion in queens at 21-22 or 35-38 days of pregnancy. © 2012 Blackwell Verlag GmbH.

The Scentless Plant Bug, Lyorhyssus hyalinus (Fabricius) (Hemiptera: Heteroptera: Rhopalidae): Description of immature stages and notes on its life history. Cornelis, Marcela Fabiola; Quirán, Estela Maris; Coscarón, María del Carmen Instars I–V and eggs of Liorhyssus hyalinus (Fabricius) (Heteroptera: Rhopalidae) are described and illustrated based on specimens from La Pampa, Argentina. Host plant and parasite data are given for this species

Determinación de nitrógeno inorgánico y fosfatos a distintas profundidades de suelo bajo pilas de abonos; Determination of Inorganic Nitrogen and Phosphates at Different Soil Depths Beneath Manure Piles Ferrari, Javier Luis; Martinez Carretero, Eduardo Enrique; Cremona, Victoria; Mazzarino, Maria Julia En la región Andino-patagónica frecuentemente la reposición de nutrientes para diferentes cultivos se lleva a cabo mediante el uso de estiércoles mezclados con viruta, comúnmente denominados abonos. Los mismos son acumulados en pilas de 1,5-2 m de altura. Al permanecer durante un período de tiempo al aire libre puede producirse un compostaje parcial, lo cual sería beneficioso. El compostaje es un proceso biooxidativo que involucra un sustrato orgánico, una etapa termofílica que debe alcanzar los 55ºC y una etapa de maduración. Si los abonos permanecen a la intemperie los nutrientes pueden ser transportados por el agua de percolación (particularmente en los meses de invierno de mayor precipitación), perdiéndose del suelo. Con el objetivo de determinar si ocurre un movimiento de fosforó extractable en NaHCO3 0.5M (P-Ol de fósforo Olsen) y nitrógeno inorgánico (Nin de nitrógeno inorgánico, amonio más nitratos) bajo pilas de abono, se tomaron muestras compuestas de suelos de tres bloques a distintas profundidades en un establecimiento cercano a la localidad del Bolsón. Se estudió también la relación entre P-Ol (índice agronómico) y fósforo extractable en 0,01M de CaCl2 (índice ambiental). Se tomaron las temperaturas de las pilas de abono en distintas estaciones del año. Para Nin se observó una alta dispersión en los datos y valores promedio excesivamente altos hasta 200 cm de profundidad. Los valores promedio (de tres bloques) encontrados para P exceden el umbral límite de 60 mg kg-1 P-Ol solo en la primera fecha de muestreo, aunque valores puntuales por bloque llegaron a 52 mg kg-1 a una profundidad de 40-60 cm. Se encontró una regresión lineal estadísticamente significativa entre P-Ol y P-CaCl2 en suelos y un umbral entre 50/60 mg kg-1 P-Ol similar al observado en la bibliografía. Se encontraron valores muy altos para ambas variables en los abonos. Es recomendable proteger las pilas de abono de las lluvias en los meses de invierno.; In the Andean – Patagonian region, nutrient supply for different crops is frequently made using wood chips mixed with manure. These materials are accumulated in piles of 1.5 – 2 m height. As the piles remain for a period of time outdoors, a partial composting may occur, which would be beneficial. Composting is a biooxidative process, involving an organic substrate, a thermophilic phase that must be reached (55ºC) and a maturity stage. If the manure piles remain outdoors, nutrients can also be transported by water and lost from the soil through percolation (particulary during winter months of higher precipitations). With the objective of studying if extractable phosphorus in NaHCO3 0.5M (P-Ol of phosphorus Olsen) and inorganic nitrogen (Nin;ammonium plus nitrates) move beneath the piles of manure, composites soil samples were taken from three blocks at different depths in a farm near the town of El Bolsón. The relationship between P-Ol (agronomic threshold) and extractable P in 0.01 M CaCl2 (environmental threshold) was also studied. Manure temperatures were taken in different seasons. Nin showed a high data dispersion and excessively high mean values up to the 200 cm depth. Average values (of three blocks) found for P exceeded the threshold limit of 60 mg kg-1 P-Ol only on the first sampling date in the 0-20cm depth, although individual data for each block reached 52 mg kg-1 in the 40-60 cm depth. A statistically significant linear regression between P-Ol and P-CaCl2 in soils was obtained, and a threshold near 50/60 mg kg-1, similar to the values reported in the literature. High values for both parameters were found in manures. It is advisable to protect piles of manure from rainfall in winter months.

Good habits come first in Science too: A reply to Straka and Starkzomski Bortolus, Alejandro Letter reply and "Guiding Authors -Project" proposal.

Lectotipificaciones en Ophryosporus (Asteraceae, Eupatorieae, Critoniinae); Lectotypifications in Ophryosporus (Asteraceae, Eupatorieae, Critoniinae) Plos, Anabela; Sancho, Gisela Se tipifican 10 nombres pertenecientes a especies de Ophryosporus, como una contribución nomenclatural a una próxima revisión taxonómica del género.; Lectotypifications in Ophryosporus (Asteraceae, Eupatorieae, Critoniinae). Typification is provided for 10 names of Ophryosporus as a nomenclatural contribution to a forthcoming taxonomic revision of the genus.

El deterioro laboral de las poblaciones de Catamarca y Tucumán (1980-2002) Osatinsky, Ariel A comienzos del siglo XXI los problemas de empleo afectaban a un porcentaje elevado de la población económicamente activa (PEA) de Catamarca y de Tucumán. Tanto la desocupación, la subocupación como el empleo informal habían tenido un pronunciado incremento en las décadas de 1980 y 1990 en ambas provincias. Sin embargo, en Tucumán el deterioro laboral fue mayor. Aquellos fueron años en los que las transformaciones económicas tuvieron características marcadamente regresivas. Estos cambios económicos no se produjeron en los mismos momentos, ni de forma similar, ni con la misma intensidad en Catamarca y Tucumán. En ese sentido, el objetivo del artículo es analizar la evolución y características de los problemas de empleo que afectaron a las PEA de ambas provincias entre 1980 y el 2002, vinculando éstos con las transformaciones económicas mencionadas. A través del análisis de indicadores laborales y económicos de relevancia, se pudo constatar que el mayor deterioro laboral que afectó a la población tucumana estuvo vinculado a las transformaciones productivas más negativas que atravesó su economía. Por su parte Catamarca, que atravesó dificultades económicas de menor gravedad, tenía una mayor presencia del Estado, que actuaba como atenuante ante los crecientes problemas de empleo del período.; By the beginnings of the XXI century, problems in the job market affected a high percentage of the Economically Active Population –EAP– in Catamarca and Tucuman. During the 1980 and 1990 decades, all unemployment, underemployment and informal employment had seen a deep increase in both provinces. However, the deterioration in the job market was worse in Tucuman. During those years, markedly regressive economic transformations took place. These economic changes did not take place at the same exact moments, or in similar way, or with the same intensity in Catamarca and Tucuman. The purpose of this article is to analyze the evolution and characteristics of the employment problems that affected both provinces' EAP between 1980 and 2002, linking them to the aforementioned economic transformations. By analyzing relevant job-market and economic indicators, we were able to assess that the largest deterioration in the job market in Tucuman was linked to the most negative productive transformations suffered by its economy. In Catamarca, which suffered less severe economic difficulties, there was a more important presence of the State, which acted as a mitigating factor in front of the growing employment problems.

Tendencias innovadoras en las prácticas psiquiátricas: Argentina, 1960-1970; Innovative practices in Psychiatry: Argentina, 1960-1970; Tendências inovadoras nas práticas psiquiátricas: Argentina, 1960-1970 Golcman, Aida Alejandra El trabajo analiza prácticas psiquiátricas innovadoras que se llevaron a cabo en Argentina durante las décadas del sesenta y setenta, a partir del estudio del Hospital José Esteves en la provincia de Buenos Aires. Objetivo: presentar la convivencia de paradigmas diferentes y en tensión referentes a la salud mental en una misma institución, con las complejidades que este escenario apareja. Metodología: para este estudio se utilizaron como fuente principal las historias clínicas de las pacientes admitidas en el Hospital entre 1960 y 1979, las que fueron cruzadas con publicaciones de diarios y revistas de la época. Resultados: del análisis se desprende que el contexto político de la época ?de dictadura militar, de anulación de expresión política y persecución ideológica? influyó en el desarrollo de las experiencias psiquiátricas innovadoras. De este modo, se detectaron situaciones de antisemitismo y persecución ideológica a los trabajadores de la salud que participaron de estos proyectos, al tiempo que se confundieron conceptos y propuestas terapéuticas con ideas políticas ?comunistas?. Conclusiones: a pesar de que la introducción de concepciones y prácticas diferentes sobre la salud mental generó cierta resistencia entre los psiquiatras más ortodoxos, la presencia de paradigmas distintos muestra un plan, tanto político como profesional, para transformar la Psiquiatría y la internación en Argentina; The paper analyzes innovative psychiatric practices that took place in Argentina during the sixties and seventies at the Hospital Jose Esteves in the province of Buenos Aires. Objective: To present the coexistence of different paradigms related to mental health in the same institution and to analyze the complexities generated by this scenario. Methodology: This study uses primary sources in the form of medical records of patients admitted to the hospital between 1960 and 1979. The medical records were cross-referenced with publications of newspapers and magazines of the time. Results: The analysis shows that the political environment during the era of military dictatorship —characterized by ideological persecution and the inhibition of political expression — influenced the development of innovative psychiatric practices. At the same time, instances of anti-Semitism and ideological persecution among health workers affected therapeutic approaches. Conclusions: While the introduction of innovative practices in mental health led to some resistance among the more orthodox psychiatrists, the presence of different paradigms shows a plan, both political and professional, to transform psychiatry and admission policy in Argentina.; O trabalho analisa práticas psiquiátricas inovadoras que se levaram a cabo na Argentina durante as décadas sessenta e setenta, a partir do estudo do Hospital José Esteves na província de Buenos Aires. Objetivo:apresentar a convivência de paradigmas diferentes e em tensão referentes à saúde mental em uma mesma instituição, com as complexidades que este cenário aparelha. Metodologia: para este estudo utilizou-se como fonte principal as histórias clínicas das pacientes admitidas no Hospital entre 1960 e 1979, as quais foram comparadas com publicações de jornais e revistas da época. Resultados: da análise se desprende que o contexto político da época (de ditadura militar, de anulação de expressão política e persecução ideológica) influiu no desenvolvimento das experiências psiquiátricas inovadoras. Deste modo, detectaram-se situações de anti-semitismo e persecução ideológica aos trabalhadores da saúde que participaram destes projetos, ao tempo que se confundiram conceitos e propostas terapêuticas com ideias políticas “comunistas”. Conclusões: a pesar que a introdução de concepções e práticas diferentes sobre a saúde mental gerou certa resistência entre os psiquiatras mais ortodoxos, a presencia de paradigmas distintos mostra um plano, tanto político quanto Professional, para transformar a psiquiatria e a internação na Argentina.

Los avatares del psiquismo en las ciencias sociales Golcman, Aida Alejandra Este trabajo articula ciertos conceptos presentados por Norbert Elias con nociones psicoanalíticas que permiten profundizar las ideas del autor. Para desarrollar esta relación, elegimos principalmente dos temáticas: por un lado la cuestión de la psicogénesis en el proceso de civilización de la humanidad y por otro, la preocupación por el trauma, el hecho no resuelto que retorna, y su mirada vinculada con el nazismo y la actualidad de Alemania. Con las cuestiones desarrolladas, Elias hace un corte transversal de ciertas estructuras y hechos sociales; además de permitir pensarlas desde la sociología, la historia y la psicología, nos advierte sobre los peligros de las concepciones estáticas de la sociedad; así plantea la necesidad de entender los procesos, con sus avances y retrocesos en el largo plazo.; This work uses psychoanalytic ideas to expand upon concepts presented by Norbert Elias. We focus on two main themes: (1) the role of psychogenesis in the process of civilization, and (2) trauma and Elias' perspectives on Nazism and modern Germany. Using these topics and drawing on Sociology, History, and Psychology, the author examines structures and social events that remind readers of the dangers of static conceptions of society and the need to understand societal processes in the long term.

Soil productivity from the sandy pampas region under the present agricultural conditions Diaz Zorita, Martin During the last decade, major changes in the organization, extension and intensification of the agricultural systems from the sandy pampas region are observed. Crop production is mostly performed under continuous zero tillage and with the application of fertilizers. In this region, strong relationships between crop yields and soil properties, mostly related to water and nutrient storage, have been described. The purpose of this presentation is to discuss, supported by specific local long-term field trials, about several of the changes in the productivity of the soils of the region under the present management practices. Soil organic matter levels decrease under continuous tillage practices after systems with pastures. But, the application of zero tillage practices contributed to maintain the original soil productivity properties. Production systems established on degraded soils frequently show less water use efficiency, mainly when are cropped with maize (Zea mays L.). The establishment of continuous fertilization programs based on the sufficiency for low mobility nutrients (e.g. Phosphorus) shows reduction in the soil extractable levels of the nutrient and lower mean crop production compared with maintenance fertilization programs. The use of winter cover crops in soybean [Glycine max (L.) Merrill] monoculture enhances physical soil properties without benefits on crop yields. The crop and soil management practices widely performed during this period have contributed to the soil conservation and to the water use efficiency. However, the application of sufficiency fertilization programs could conduct to the reduction in the levels of soil extractable nutrients and in crop productivity. The present agricultural land use in the region requires to intensify in the use of indexes for the diagnosis of soils productivity independently of the actual relationships with today`s yields. The delimitation of homogeneous areas for the application of efficient soil management practices is needed for the conservation and enhancement of soils productivity capability.

The role of salicylic acid in the prevention of oxidative stress elicited by cadmium in soybean plants Noriega, Guillermo Osvaldo; Caggiano, Ethel; López Lecube, Manuel; Santa Cruz, Diego Mario; Batlle, Alcira María del C.; Tomaro, Maria Lujan; Balestrasse, Karina Beatriz The protective action of salicylic acid (SA) pre-treatment on soybean plants before cadmium (Cd) addition was tested. Oxidative stress parameters, such as TBARS formation, glutathione and chlorophyll content, were altered by Cd, instead no differences were observed in plants only pre-treated with SA. Antioxidant enzymes were affected by Cd treatment, while SA protected against these effects. These findings indicated that SA could act as a protector against oxidative stress induced by Cd. Taking into account the fact that heme-oxygenase-1 (HO-1) has been previously described as a novel antioxidant enzyme, experiments were carried out to determine whether it was involved in the protection exerted by SA. As expected, Cd brought about an enhancement of 57 % in HO-1 activity and 150 % in protein content (150 %), SA also increased both the enzyme activity and its protein content (28 and 75 %, respectively). Surprisingly, the observed rise of HO activity and protein content under SA treatment was lower than that produced by Cd alone. These lower values indicated, that HO-1 could not be directly involved in the protection of SA against Cd effects. In order to shed light in the mechanisms involved in SA effects, Cd content was determined in the tissues of Cd treated plants with and without SA pre-treatment. Results indicated that, in the presence of SA, Cd uptake was inhibited, thus avoiding its deleterious effects. Moreover, the observed HO-1 activity enhancement by SA indicates that this phytohormone could be engaged in the signalling pathway of heme degradation. Copyright © Springer Science+Business Media, LLC. 2012.

Mineral chemistry and geothermometry using relict primary minerals in the La Cocha ultramafic body: A slice of the upper mantle in the Sierra Chica of Córdoba, Sierras Pampeanas, Argentina Anzil, Patricia Andrea; Guereschi, Alina Beatriz; Martino, Roberto Donato The La Cocha ultramafic body, in the Sierra Chica of Córdoba (Sierras Pampeanas, Argentina), is formed by serpentinized spinel harzburgites, with lenses of spinel pyroxenites and hornblendites. The associated metamorphic rocks are garnet sillimanite gneisses, intercalated with tabular bodies of pyroxene amphibolites and forsterite marbles.Mineral chemistry of relict primary phases (olivine, orthopyroxene and spinel) from samples of the spinel harzburgites and pyroxenites was determined, and several geothermometers were applied to estimate the temperature conditions under which these rocks may have been equilibrated.In the spinel harzburgites, the primary spinel is Al-chromite [Cr# = Cr/(Cr + Al) = 0.48-0.57], which is replaced by ferrichromite and chlinoclore by metamorphism. Orthopyroxene is enstatite (En92) and olivine is classified as forsterite (Fo92); this last one shows a homogeneous and constant composition along the ultramafic body. Using geothermometric calibrations of the pair olivine-spinel, the highest temperature of 1157 °C would correspond to the primary conditions of formation of the harzburgites.The spinel pyroxenites show a mineral composition defined by orthopyroxene (En85, enstatite), olivine (Fo86, chrysolite), spinel (s. s.) and magnetite. Serpentine and clinochlore were produced by metamorphism. Spinel has high concentrations in Al and very low in Cr, and is classified as spinel sensu stricto; magnetite replacement was produced by metamorphism. Orthopyroxene and olivine are depleted in MgO regarding these minerals in the harzburgites. Temperatures of 785-734 °C calculated using geothermometers with orthopyroxene are interpreted to be produced by metamorphism in amphibolite to granulite facies conditions.Cumular textures were not observed in outcrops and thin sections of the studied rocks. The narrow composicional range and high forsterite content in olivine, the high Cr# in spinel, and the low concentrations of Ni and Cr in whole rock analyses indicate a mantle residual origin for these peridotites, which would exclude a cumular origin.The association of peridotites with mafic bodies formed in an N-type MORB environment and a relict mantle fabric showed by the elongated crystals/aggregates of olivine (preserved in pseudomorphic replacements), indicating a high temperature flow, allow to interpret the La Cocha ultramafic body as a slice of oceanic mantle, belonging to basal tectonites of an ophiolite complex. This body shows similar petrological, geochemical and structural features than the other ultramafic bodies in the Sierras de Córdoba, therefore the origin proposed here could be applied to the other bodies.

Dinámicas del sector agropecuario argentino en el siglo XXI: La distribución del ingreso en regiones pampeanas y extrapampeanas Mario, Agustin Angel; Vidosa, Regina En este trabajo se analizan una serie de aspectos que resultan centrales para comprender la situación de los trabajadores en el sector agropecuario. En primer lugar, se contrapone la evolución del producto del sector con la capacidad que el mismo posee para generar puestos de trabajo. Luego, se da cuenta de las condiciones de empleo que se verifican en el sector agropecuario, poniendo especial énfasis en el estudio del grado de informalidad y los niveles salariales. Se compara, a continuación, la distribución primaria del ingreso del sector con la de la economía nacional en su conjunto. Este análisis distributivo se complementa con dos estudios de caso que intentan poner de manifiesto las implicancias que poseen distintos cultivos llevados a cabo en diferentes regiones. El estudio muestra que el salario medio del sector agropecuario sigue estando muy por debajo de la remuneración promedio de la economía y que, además, la participación de los salarios en el valor agregado del sector se ha reducido desde la salida de la convertibilidad aún en un contexto de aumento del salario medio sectorial. Finalmente, con base en el análisis de los casos mencionados, se asocia la distribución del ingreso con los distintos cultivos y las regiones donde estos se llevan a cabo. Al respecto, se discute el rol de las ganancias individuales como guía orientadora del uso de la tierra cultivable.; This paper discusses a number of issues that are central to understanding the situation of workers in the agricultural sector. First, the evolution of the sectorial product is contrasted with the capacity that it posseses to generate jobs. Then, the working conditions verified in the agricultural sector are described, with particular emphasis on the study of the degree of informality and the wage levels. It then compares the primary distribution of income of the sector to that of the national economy as a whole. This distributional analysis is complemented by two case studies that attempt to show the implications that distinct crops carried out in different regions have. The study shows that the average wage in the agricultural sector remains well below the average wage in the economy and, in addition, the share of wages in the sectorial value added has declined since the end of the convertibility regime, even in a context of an increasing average wage in the sector. Finally, based on the analysis of the above cases, income distribution is associated to the different crops and the regions where they are carried out. In this regard, the role of individual earnings as a guide to the use of arable land is discussed.

Phosphorylation of Mitogen-Activated Protein Kinases Contributes to Interferon γ Production in Response to Mycobacterium tuberculosis Pasquinelli, Virginia; Rovetta, Ana Inés; Alvarez, Ivana Belén; Jurado, Javier Oscar; Musella, Rosa María; Palmero, Domingo J.; Malbrán, Alejandro; Samten, Buka; Barnes, Peter F.; García, Verónica Edith Immune control of Mycobacterium tuberculosis depends on interferon γ (IFN-γ)–producing CD4+ lymphocytes. Previous studies have shown that T cells from patients with tuberculosis produce less IFN-γ, compared with healthy donors, in response to mycobacterial antigens, although IFN-γ responses to mitogens are preserved. In this work, we found that M. tuberculosis–induced IFN-γ production by human T cells correlated with phosphorylation of the mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK), and p38. Moreover, the majority of IFN-γ–producing T cells expressed signaling lymphocyte activation molecule (SLAM), and SLAM activation further increased ERK phosphorylation. Interestingly, patients with tuberculosis had delayed activation of ERK and p38, and this was most marked in patients with the poorest IFN-γ responses (ie, low responders). Besides, SLAM signaling failed to phosphorylate ERK in low responders. Our findings suggest that activation of p38 and ERK, in part through SLAM, mediates T-cell IFN-γ production in response to M. tuberculosis, a pathway that is defective in patients with tuberculosis.

Instituciones, investigadores y comunidades indígenas chaqueñas; Institutions, researchers and Chaquean indigenous communities: triangulation of interests around State photographic archives Giordano, Mariana Lilian La constitución de fondos documentales fotográficos que surgieron de intereses estatales desde fines del siglo XIX se presenta como una de las tantas modalidades de perpetuación de la captura de los “otros” indígenas, que responde a su vez a las maneras de definir la ciencia, de afirmar el poder del Estado sobre los “otros” y de constituir identidades nacionales y memorias recortadas. Este artículo se introduce en el mundo de los fondos fotográficos de indígenas del Gran Chaco teniendo en cuenta que los mismos no son construcciones de existencia neutra e invariable, sino que tienen una “vida” que refleja los intereses de diversos agentes que lo guardan y/o que pretenden utilizarlos, difundirlos o poseerlos. A la vez, indaga en el rol que las fotografías desempeñan en la construcción de memorias en las comunidades indígenas chaqueñas actuales y la legitimidad que éstas poseen en las demandas por las mismas, poniéndose en discusión la cuestión de la “propiedad” de las imágenes. Tales reflexiones se consideran en torno a los conceptos de hegemonía y colonialidad del poder. De tal forma, planteamos una mirada triangular hacia las instituciones –en particular las estatalesque conservan las imágenes, hacia nuestro propio interés y rol de investigador sobre las fotos en estudio y hacia las intenciones y demandas de las comunidades indígenas chaqueñas actuales respecto de estos fondos.; The constitution of documentary photography from states’ interests comes from the late nineteenth century and it is presented as one of the many modalities of perpetuating the capture of the “other” indigenous. That situation responds to the different ways of defining science, to assert state power over “others” and to establish national identities and biased memories. This article introduces into the world of photographic collections of indigenous of the Gran Chaco taking into account that they are not neutral constructions of unchanging existence; eventhough, they have a “life” that reflects the interests of different stakeholders who keep them or intend to use, spread or possess them. Besides, we analyze the role that these photographs have in building memories within Chaco indigenous communities today. Therefore, we also call into question the copyright or “property” of images. These reflections are considered around the concepts of hegemony and coloniality of power. Thus, there is a triangular look towards the institutions, -including state ones- that preserved the images, to our own interest and our role as researchers on photos and into the intentions and demands of Chaco indigenous communities.