Optimization of production of chlamydospores of the nematode-trapping fungus Duddingtonia flagrans in solid culture media Sagüés, María Federica; Alberto, Fusé Luis; Iglesias, Lucía Emilia; Moreno, Fabiana Carina; Saumell, Carlos Alfredo The large-scale production of nematophagous fungi as agents of biological control is one of the main challenges to be commercially used. In order to improve growth of microorganism in a culture medium, the addition of growth inducer is common. At the moment, the action of their addition in the mycelia growth and sporulation rate of nematophagous fungi is not known. The purpose of this trial was to evaluate the sporulation rate of Duddingtonia flagrans by adding two growth inducers, meso-inositol and Tween 80, both at 0.5 % in a traditional culture medium Sabouraud glucose agar (SGA) and also in a traditional culture medium enriched with wheat flour and milk powder. From a traditional sterile culture of D. flagrans, four groups were made: SGA; Sabouraud glucose agar-meso-inositol 0.5 %; Sabouraud glucose agar-Tween 80 0.5 %; and Sabouraud glucose agar-enriched (SGA-E). These media were placed at a constant temperature of 27 C for 4 weeks. Following this, chlamydospores were gently rinsed off with sterile water and counted using a Neubauer haematocytometer to estimate the number of chlamydospores per millilitre of water. The addition of meso-inositol 0.5 % to SGA promoted a significant increase (p < 0.05) in chlamydospore production obtaining an average of 51,715,000 chlamydospores per Petri dish. The highest chlamydospore concentration was observed in the SGA-E in comparison with SGA (p < 0.01) obtaining an average of 208,760,000 chlamydospores. The aim of this study was to obtain basic knowledge regarding the effect of enriched culture medium and growth-inducing meso-inositol and Tween 80 on mycelial growth and production of chlamydospores.

Discursos para la "sociedad de la información": Un análisis crítico sobre ciudades digitales en Argentina; Discourses for “information society”: A critical analysis of digital cities in Argentina Yeremian, Ana Gabriela; Remondino, Georgina Lía Este trabajo presenta una mirada crítica sobre aquellos discursos que desde diversos ámbitos promocionan a la llamada “Sociedad de la Información” (SI). Atendemos a ellos porque motivan en la actualidad prácticas particulares que modifican formas de intervención en el espacio público, como es el caso de las “ciudades digitales”. En un primer momento reflexionamos -en base a aportes de la filosofía de la técnica, de la sociología y la comunicación social- sobre las promesas de la SI como modelo de sociedad y el valor que en él adquieren las “tecnologías de la información y la comunicación” (TICs). Sostenemos que la SI y las TICs se encarnan en dispositivos, prácticas y discursos situados en sociedades y actores concretos. Seguidamente, analizamos algunos proyectos de “ciudades digitales” en Argentina que resultan de especial interés para revisar los modos en que la SI permea políticas públicas, generando sentidos en relación a los modos de concebir a la ciudad, a los actores sociales y a su vínculo con las instancias gubernamentales. En las conclusiones compartimos algunas reflexiones sobre las modalidades con que estos discursos delimitan “lo público” y en la centralidad que adquiere la comunicación para pensar las ciudades y los modos de vida contemporáneos.

Adsorption microcalorimetry applied to the characterisation of adsorbents for CO 2 capture Miranda da Silva, F. Wilton; Soares Maia, Debora Aline; Oliveira, Ronan S.; Moreno Piraján, Juan Carlos; Sapag, Manuel Karim; Cavalcante, Célio Loureiro; Zgrablich, Giorgio; Azevedo, Diana Cristina Silva de The present work presents the design, assembly and experimental validation of a microcalorimetric device coupled to a volumetric adsorption setup applied to the characterisation of adsorbents for carbon dioxide (CO 2) capture. Three adsorbents were evaluated for CO 2 adsorption at 273K in the pressure range of vacuum to 101kPa. The data for CO 2 on zeolite 13X agreed well with the available data reported in the literature, thus validating the device, which also provided reproducible results with an activated carbon sample. For the amine-modified zeolite, the differential enthalpy at lower coverage was increased by a factor of 1.7 as compared to the zeolite matrix. This points out to the potential of such technique to characterise heterogeneities introduced by amine impregnation. However, the adsorption uptake was decreased by factor of 2.7 at 101kPa. This fact suggests that amino groups may be blocking some physisorption sites, leading to restricted chemisorption on the outer surface. Thus, the main novelty of this study is the simultaneous measurement of adsorption isotherms and respective differential enthalpy curves for amine-impregnated adsorbents, which may be considered a fingerprint of the modified surface chemistry. This work has been carried out in the framework of a cooperation project between three South American universities and is part of the effort to develop and fully characterise adsorbent materials intended for CO 2 capture.

Alianza para el Progreso cincuenta años después: La política exterior de Obama en acción Romano, Silvina Maria Partiendo de los discursos de campaña electoral de Obama que proponían una “nueva alianza” para las Américas centrada en la diplomacia, la democracia y la asistencia para el desarrollo, y considerando los principales lineamientos de relaciones exteriores demarcados por el Departamento de Estado de la administración Obama centrados en las “Tres D” (desarrollo, diplomacia y defensa), entendemos que este “giro” frente a la anterior administración de George W. Bush, retoma en buena medida los ideales promovidos por el gobierno de John F. Kennedy (1961-1963), especialmente las premisas de la Alianza para el Progreso (1961). La pregunta es por qué Obama y su establishment retoman en la coyuntura actual la retórica de la Alianza para el Progreso y qué implicancias tiene ello para América Latina. Para ello, abordaremos las principales características de la Alianza para el Progreso, por medio del trabajo con fuentes documentales (en especial los documentos desclasificados del Departamento de Estado de Estados Unidos).

Assessing invasion process through pathway and vector analysis: case of Saltcedar (Tamarix spp.) Natale, Evangelina Sandra; Zalba, Sergio Martín; Reinoso, Herminda Elmira; Damilano, Gabriela Biological invasions are one of the most pervasive environmental threats to native ecosystems worldwide. The spontaneous spread of saltcedar is a particular threat to biodiversity conservation in arid and semiarid environments. In Argentina, three species belonging to this genus have been recognized as invaders. The aim of the present study was to identify main dispersal vectors and pathways to refine risk analysis and increase our ability to predict new areas at risk of Tamarix establishment. We surveyed and categorized 223 populations, 39% as invasive, 26% as established, 21% as contained and 14% as detected in nature. Dispersion of saltcedar was found to be associated with watercourses and human-driven disturbances; in addition roads were found to be relevant for the introduction of propagules in new environments. Considering the potential impact of saltcedar invasion and that it is an easily wind-dispersed invasive, it is necessary to implement strategies to monitor dispersal pathways and take actions to eliminate invasion foci, particularly in vulnerable and high- conservation value areas.

Distintas frecuencias de fuegos controlados en el sur del Caldenal: efectos sobre la vegetación leñosa Pelaez, Daniel Valerio; Andrioli, Romina Jessica; Elia, Omar Raul; Blazquez, Francisco Ruben El fuego es un factor natural en los pastizales naturales y ha ocurrido desde que la vegetación está presente sobre la tierra. Históricamente los fuegos naturales ocurrieron cuando la acumulación de combustibles y las condiciones climáticas favorecían la ignición y la propagación del fuego. La ocurrencia de los mismos ha sido largamente reconocida como un disturbio que previene la invasión de especies leñosas en ecosistemas dominados por gramíneas perennes (Wright y Bailey 1982, Whelan 1995). En los pastizales semiáridos del Distrito Fitogeográfico del Caldén (Cabrera 1976), comúnmente conocido como el Caldenal, los fuegos naturales son eventos comunes durante los veranos secos y calurosos. El intervalo actual entre fuegos en la región es de 10 o más años, mucho mayor que el histórico (5-6 años). La menor acumulación de combustible fino (pasto) debido al pastoreo continuo con altas cargas animales, que ha sido (y es) la forma de utilización más frecuente de los pastizales desde la introducción del ganado doméstico a fines del siglo XIX, y la construcción de contrafuegos aumentaron el período libre de fuego en la región.

Historia del discurso científico en la Argentina. Retóricas de la legitimación de la ciencia incipiente y los científicos Vallejos, Patricia Silvia El discurso de las ciencias constituye un fenómeno complejo en cuyo estudio deben considerarse múltiples factores, entre los que se destacan, en primer lugar, los recursos y operaciones retóricas que intervienen tanto en la construcción y comunicación de los saberes sobre el mundo y la realidad, como en la legitimación de la autoridad de los científicos ante su comunidad de pares. Asimismo, el estudio desde una perspectiva histórica permite reconocer en estos discursos problemáticas epistemológicas o sociales vinculadas con el desarrollo de las ciencias, referidas tanto a la especificidad de las disciplinas, sus teorías o métodos, como también con factores del contexto sociopolítico que inciden en las prácticas científicas y el posicionamiento de sus productores. El presente trabajo se centra en dos de estas problemáticas y estudia su manifestación en la configuración retórica de distintas expresiones de la escritura científica de los campos de la historiografía y la paleontología en el seno de la comunidad científica argentina de la etapa positivista. En tanto adopta una perspectiva histórica y se dirige al reconocimiento de la retórica empleada ya para el logro de los objetivos epistémicos o también sociales del trabajo y la comunicación científica, este trabajo puede contribuir a las investigaciones de la historia de la ciencia en la Argentina, en sus vertientes epistemológica o social.; This paper studies the discourse of sciences from the fields of history and paleontology in the context of scientific positivism in Argentina. The aim is to examine rhetorical configurations in different expressions of scientific writing and their incidence in the development of theories and practices of those sciences in the scientific community of the time.The study adopts a historical stance of discourse analysis, and aims to unveil the rhetorical means employed both for the epistemic and social goals of scientific work and communication. This approach emphasizes the importance of studies of ideational and interpersonal rhetorics in that they reveal themselves to be an essential complement of the historical research not only on epistemic but also social aspects of the construction of scientific knowledge.In this sense, it may contribute to historical and sociological research on scientific practices in Argentina.

Fossil pollen records reveal a late rise of open-habitat ecosystems in Patagonia Palazzesi, Luis; Barreda, Viviana Dora The timing of major turnovers in terrestrial ecosystems of the Cenozoic Era has been largely interpreted from the analysis of the assumed feeding preference of extinct mammals. For example, the expansion of open-habitat ecosystems (grasslands or savannas) is inferred to have occurred earlier in Patagonia than elsewhere because of the early advent of high-crowned teeth (hypsodont) mammals ∼26 Ma ago. However, the plant fossil record from Patagonia implies another evolutionary scenario. Here we show that the dominance of key open-habitat species - amaranths, Ephedra, asters and grasses - occurred during the last 10 Ma, about 15 Ma later than previously inferred using feeding/habitat ecology of extinct mammals. This late rise of open-landscapes in southern South America brings into question whether the expansion of open-habitat vegetation could have been the prime factor of high-crowned mammal diversification.

Quaternary Ammonium “Tannate” for Antifouling Coatings Bellotti, Natalia; del Amo, Delia Beatriz; Romagnoli, Roberto The undesirable accumulation of a wide variety of marine organisms (biofouling) on ship hulls can lead to significantly increased costs, principally by increased fuel consumption to maintain cruising speed. Generally, these coatings have bioactive compounds, called biocides. In this sense, this paper deals with the assessment of the antifouling properties of a natural product derivative obtained from "quebracho" tannin and a quaternary ammonium salt (hexadecyltrimethylammonium bromide ([CH3(CH 2)15N(CH3)3]Br). Two derivatives were obtained depending on the precipitation pH (4 and 8). The bioactivity of these derivatives was assessed by means of the Artemia test. Furthermore, soluble matrix paints were prepared with two different binders: rosin/oleic acid and rosin/styrene-acrylate copolymer. The leaching of "quebracho" tannin derivatives from coatings in artificial seawater was monitored until constant values were obtained, previous to the immersion in natural environments. Finally, the antifouling activity of coatings pigmented with the "quebracho" tannin derivative was evaluated in Mar del Plata harbor (38°08′17″S-57 31′18″W). The coating obtained with the derivative obtained at pH 4 and rosin/oleic acid as binder proved to have an acceptable efficiency for 10 months.

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.