Bis(acetato-κ2 O,O')(4,4′-dimethyl-2,2′- bipyridine-κ2 N,N')zinc Harvey, Miguel Angel; Suarez, Sebastian; Ibañez, Andres; Doctorovich, Fabio; Baggio, Ricardo Fortunato The molecular structure of the title compound, [Zn(CH3COO) 2(C12H12N2)], consists of isolated molecules bisected by a twofold rotation axis which goes through the ZnII cation and halves the organic base through the central C-C bond. The Zn II ion is coordinated by two N atoms from one molecule of the aromatic base and four O atoms from two bidentate, symmetry-related acetate anions, which coordinate asymmetrically [Zn-O distances of 2.058(2) and 2.362(3)Å], while the two Zn-N bond distances are equal as imposed by symmetry [2.079(2)Å]. The crystal structure is supported by a number of weak C-H⋯O interactions and C-H⋯π contacts, with no π-π interactions present, mainly hindered by the substituent methyl groups and the relative molecular orientation. The result is a three-dimensional structure in which each molecule is linked to eight different neighbors.

El problema de marco como nudo teórico en la interfaz entre la filosofía y las ciencias cognitivas; The frame problem as a theoretical knot within the interface area between philosophy and cognitive sciences; O problema de marco como nó teórico na interface entre a filosofia e as ciências Silenzi, María Inés El tópico que trata sobre las relaciones entre la filosofía y otras disciplinas es com-plejo y requiere necesariamente de una revisión bibliográfica y un análisis mucho más extenso de lo que podríamos desarrollar en este trabajo. Por lo tanto, vamos a restringir esta cuestión mediante la limitación de la zona de interfaz que se establece entre la filosofía y la ciencia cognitiva, teniendo en cuenta el problema del marco como nudo entre ambas disciplinas. Ubicados dentro de esta zona de interfaz, nos preguntamos: ¿podrían influir los nuevos marcos teóricos de las ciencias cognitivas en la resolución del problema de marco? Consideramos que este problema podría ser solucionado desde una posición híbrida, que contenga a ambos paradigmas de las ciencias cognitivas.; The topic establishing the relationships between philosophy and other disciplines is complex and it necessarily requires a literature review and an analysis much more extensive than we could develop in this paper. Therefore, we will restrict this question by limiting the interface area established between philosophy and cognitive science, considering the frame problem as a theoretical knot between both disciplines. Located within this interface zone we ask: could the new theoretical frameworks of cognitive science (and their discoveries) have influence upon solving the frame problem? We believe that this problem could be solved from a new hybrid position containing both cognitive science paradigms.; O tópico que trata das relações entre a filosofia e outras disciplinas é complexo e exige necessariamente uma revisão bibliográfica e uma análise muito mais extensa do que poderíamos desenvolver neste trabalho. Portanto, vamos restringir esta questão limitando a zona de interface que se estabelece entre a filosofia e a ciência cognitiva, tendo em conta o problema do marco como nó entre as duas disciplinas. Situados dentro desta zona de interface, perguntamos: poderiam influenciar os novos marcos teóricos das ciências cognitivas na resolução do problema de marco? Consideramos que este problema poderia ser resolvido a partir de uma posición híbrida, que inclua ambos os paradigmas das ciências cognitivas.

Flexible and practical modeling of animal telemetry data: Hidden Markov models and extensions Langrock, Roland; King, Ruth; Matthiopoulos, Jason; Thomas, Len; Fortin, Daniel; Morales, Juan Manuel We discuss hidden Markov-type models for fitting a variety of multistate random walks to wildlife movement data. Discrete-time hidden Markov models (HMMs) achieve considerable computational gains by focusing on observations that are regularly spaced in time, and for which the measurement error is negligible. These conditions are often met, in particular for data related to terrestrial animals, so that a likelihood-based HMM approach is feasible. We describe a number of extensions of HMMs for animal movement modeling, including more flexible state transition models and individual random effects (fitted in a non-Bayesian framework). In particular we consider so-called hidden semi-Markov models, which may substantially improve the goodness of fit and provide important insights into the behavioral state switching dynamics. To showcase the expediency of these methods, we consider an application of a hierarchical hidden semi-Markov model to multiple bison movement paths.

Legal and institutional tools to mitigate marine turtle bycatch: Argentina as a case study González Carman, Victoria; Machain, Natalia; Albareda, Diego; Mianzan, Hermes Walter; Campagna, Claudio This paper explores conservation policy pertinent to three species of marine turtles affected by fisheries, while crossing jurisdictions in their seasonal migrations through the SW Atlantic, particularly the Argentine waters. This case study reviews local legal and institutional frameworks for Argentina and concludes that tools are in place to monitor and mitigate the negative impact of bycatch on the populations. Argentina is signatory of the most relevant international treaties aimed at protecting transboundary species (e.g. Inter-American Convention for the Protection and Conservation of Sea Turtles, Convention on the Conservation of Migratory Species of Wild Animals). Legislation also exists at the federal and provincial levels. Yet, accidental captures continue to occur due to weaknesses in enforcement and the low priority that conservation has in fisheries management decisions. Some urgent practical actions supported by policy are suggested: (a) placement of on-board observers in coastal fishing fleets, (b) application of existing mitigation measures to reduce bycatch, (c) design of a national plan of action for marine turtles in Argentina, and (d) development of a regional plan between Argentina, Brazil and Uruguay. Stakeholder involvement, especially the fishing sector but also the civil society, would be important to energize practical and effective conservation decisions. The example of Argentina is typical for the region and may apply to other countries as well. The conservation community requires investing more in the application of policy, concomitant with perfecting legal tools.

Development and preliminary validation of an antibody filtration-assisted single-dilution chemiluminometric immunoassay for potency testing of Piscirickettsia salmonis vaccines Wilda, Maximiliano; Lavoria, Maria de Los Angeles; Giraldez, Adrian Nicolas; Franco Mahecha, Olga Lucia; Mansilla, Florencia Celeste; Érguiz, Matías; Iglesias, Marcela Elvira; Capozzo, Alejandra Victoria Challenge with live pathogens could be substituted by serology for many veterinary diseases, however little progress has been made in the development of alternative batch vaccine potency tests for fish. This study reports the development and preliminary validation of a single-dilution filtration-assisted chemiluminometric immunoassay (SD FAL-ELISA) applied to measure anti Piscirickettsia salmonis IgM in individual or pooled serum and mucus samples. The assay was set up to test a single-dilution of the sample. Serum SD FAL-ELISA yielded a sensitivity of 90% and a specificity of 96%. SD FAL-ELISA was applied to evaluate pooled and individual samples from P. salmonis challenge assessments. Relative-light units values (RLU) obtained by SD FAL-ELISA were proportional to antibody levels in serum. RLU values obtained from pooled and individual serum samples increased with the observed relative percent survival (RPS) values, indicating a correlation between protection and specific IgM levels. Results obtained for specific IgM in mucus samples was not related to the RPS, but discriminated the vaccine that yielded high RPS (86.4%) from the others (40.9 and 54.5%). This is the first report on the development of an indirect high-throughput serological assessment for P. salmonis vaccine potency testing using both pooled or individual serum and cutaneous mucus samples.

Fuentes de rocas y uso de materias primas líticas en Bahía Final 6, costa norte del golfo San Matías (Río Negro, Argentina); Sources of lithic raw materials and their exploitaition at Bahía Final 6 site, northern coast of San Matías gulf, Río Negro, Argentina Alberti, Jimena Este trabajo constituye una aproximación al análisis de las estrategias de aprovisionamiento y uso de rocas en la costa norte del golfo San Matías (provincia de Río Negro, Argentina). Con este fin se muestrearon diferentes fuentes de materias primas líticas y se analizaron materiales arqueológicos provenientes de dos loci de la localidad Bahía Final, cada uno de ellos representativo de un bloque temporal distinto dentro del modelo de uso del espacio y consumo de recursos marinos propuesto para la región. A partir de los análisis realizados se presentan las tendencias generales para el aprovechamiento de rocas a lo largo del tiempo. Los resultados obtenidos sugieren que los patrones de aprovisionamiento y uso de materias primas líticas habrían estado en relación con cambios en los circuitos de movilidad de los grupos cazadores-recolectores que habitaron la zona y con las variaciones geomorfológicas acaecidas en el sector costero bajo estudio.; This paper presents an approach to the analysis of provisioning strategies and rock use in the Northern coast of San Matías gulf, Río Negro, Argentina. Our research included the survey of several sources of lithic raw materials and the analysis of lithic assemblages recovered from two Bahía Final archaeological loci, each of which represents a different span of time within the model of space use and marine resource consumption proposed for the region. The general trends in lithic raw material exploitation over time are presented. The results suggest that procurement patterns and lithic raw material use were related both to changes in the mobility circuits of the hunter-gatherers that inhabited the area and to the geomorphological evolution of the marine coast within the study area.

Comparing methods for extracting amaranthus starch and the properties of the isolated starches Villarreal, Myriam Elizabeth; Ribotta, Pablo Daniel; Iturriaga, Laura Beatriz Starch was isolated from Amaranthus cruentus whole grain (WG) and whole grain flour (WGF) using both the alkaline method (AM) and AM combined with food degree protease digestion (AMP). The methods involved successive soaking in NaOH solution (0.25 g/100 ml in AM and 0.05 g/100 ml in AMP), fibrous fraction wet milling, enzymatic hydrolysis in AMP and multi-staged centrifugation. Milling the amaranth grains in both methods increased significantly starch yield, recovery, and purity when compared against WG and lowered soaking times as well. Starch yield and recovery were 116.7% and 123.6% higher in WGF while protein, fiber, and ash contents showed decreases of about 44.4%, 34.8%, and 30.4% respectively. The effect of the extracting methods was less notorious than that of the grain milling. The results suggest that both methods are suitable for extracting starch from previously milled grains despite the fact that the AM shows significant operative advantages. The starches extracted showed conservative structure, A-type difractrometric patterns with high crystallinity degrees (∼39%) and Tg (gelatinization temperature) values (∼74 °C). These properties not present significant differences as a consequence of the extracting procedure used.

Characterization of Spherical Core-Shell Particles by Static Light Scattering. Estimation of the Core- and Particle- Size Distributions Clementi, Luis Alberto; Vega, Jorge Ruben; Gugliotta, Luis Marcelino; Quirantes, Arturo A numerical method is proposed for the characterization of core-shell spherical particles from static light scattering (SLS) measurements. The method is able to estimate the core size distribution (CSD) and the particle size distribution (PSD), through the following two-step procedure: i) the estimation of the bivariate core - particle size distribution (C-PSD), by solving a linear ill-conditioned inverse problem through a generalized Tikhonov regularization strategy, and ii) the calculation of the CSD and the PSD from the estimated C-PSD. First, the method was evaluated on the basis of several simulated examples, with polystyrene - poly(methyl methacrylate) core-shell particles of different CSDs and PSDs. Then, two samples of hematite - Yttrium basic carbonate core-shell particles were successfully characterized. In all analyzed examples, acceptable estimates of the PSD and the average diameter of the CSD were obtained. Based on the single-scattering Mie theory, the proposed method is an effective tool for characterizing core-shell colloidal particles larger than their Rayleigh limit without requiring any a-priori assumption on the shape of the size distributions. Under such conditions, the PSDs can always be adequately estimated; while acceptable CSD estimates are obtained when the core/shell particles exhibit either a high optical contrast, or a moderate optical contrast but with a high average core diameter / average particle diameter ratio.

Latin American consensus on hypertension in patients with diabetes type 2 and metabolic syndrome López Jaramillo, Patricio; Sánchez, Ramiro A.; Diaz, Margarita; Cobos, Leonardo; Bryce, Alfonso; Parra Carrillo, Jose Z.; Lizcano, Fernando; Lanas, Fernando; Sinay, Isaac; Sierra, Iván D.; Peñaherrera, Ernesto; Bendersky, Mario; Schmid, Helena; Botero, Rodrigo; Urina, Ezequiel; Lara, Joffre; Foss, Milton C.; Márquez, Gustavo; Harrap, Stephen; Ramírez, Agustín José; Zanchetti, Alberto The present document has been prepared by a group of experts, members of cardiology, endocrinology and diabetes societies of Latin American countries, to serve as a guide to physicians taking care of patients with diabetes, hypertension and comorbidities or complications of both conditions. Although the concept of 'metabolic syndrome' is currently disputed, the higher prevalence in Latin America of that cluster of metabolic alterations has suggested that 'metabolic syndrome' is a useful nosographic entity in the context of Latin American medicine. Therefore, in the present document, particular attention is paid to this syndrome in order to alert physicians on a particularly high-risk population, usually underestimated and undertreated. These recommendations result from presentations and debates by discussion panels during a 2-day conference held in Bucaramanga, in October 2012, and all the participants have approved the final conclusions. The authors acknowledge that the publication and diffusion of guidelines do not suffice to achieve the recommended changes in diagnostic or therapeutic strategies, and plan suitable interventions overcoming knowledge, attitude and behavioural barriers, preventing both physicians and patients from effectively adhering to guideline recommendations.

The effects of GpcB1 locus on high grain protein concentration introgressed into Argentinean wheat germplasm Tabbita, Facundo; Lewis, Silvina Marta; Vouilloz, Juan P.; Ortega, María de los Ángeles Haydée; Kade, Mariana; Abbate, Pablo Eduardo; Barneix, Atilio José Wheat grain protein content (GPC) is important for human nutrition and
has a strong influence on the quality of pasta and bread. The objective of
this study was to analyse the introduction of the Gpc-B1 allele into two
Argentinean bread wheat cultivars. Near-isogenic lines were developed in
?ProINTA Oasis? and ?ProINTA Granar? using marker-assisted selection.
Gpc-B1 lines showed a significant (P = 0.01) increase in GPC and a significant
(P = 0.001) decrease in grain weight in comparison with control
lines without Gpc-B1. Differences in yield were not significant
(P = 0.49) between lines. Gpc-B1 lines significantly reduced (P = 0.02)
straw nitrogen concentration at maturity and significantly increased
(P = 0.02) the nitrogen harvest index. When data were analysed by genotype
and environment, differences in some analysed parameters were
found, indicating that Gpc-B1 expression may be affected by different
genetic backgrounds and environmental conditions. These results suggest
that the introgression of the Gpc-B1 allele into Argentinean wheat germplasm
could be a valuable resource for improving GPC with no detrimental
effect on grain yield.

Arsenic effect on the model crop symbiosis Bradyrhizobium–soybean Talano, Melina Andrea; Cejas, Romina Beatríz; González, Paola Solange; Agostini, Elizabeth Soybean (Glycine max) is often being cultivated in soils with moderate to high arsenic (As) concentrations or under irrigation with As contaminated groundwater. The purpose of this study was to determine the effect of As on soybean germination, development and nodulation in soybean-Bradyrhizobium japonicum E109 symbiosis, as a first-step approach to evaluate the impact of As on soybean production. Semi-hydroponic assays were conducted using soybean seedlings inoculated and non-inoculated with B. japonicum E109 and treated with arsenate or arsenite. Soybean germination and development, at early stage of growth, were significantly reduced from 10 μM arsenate or arsenite. This also was seen for soybean seedlings inoculated with B. japonicum mainly with arsenite where, in addition, the number of effective nodules was reduced, despite that the microorganism tolerated the metalloid. This minor nodulation could be due to a reduced motility (swarming and swimming) of the microorganism in presence of As. Arsenic concentration in roots was about 250-times higher than in shoots. Transference coefficient values indicated that As translocation to aerial parts was low and As accumulated mainly in roots, without significant differences between inoculated and non-inoculated plants. The presence of As restricted soybean–B. japonicum symbiosis and hence, the efficiency of most used commercial inoculants for soybean. Thus, water and/or soils containing As would negatively impact on soybean production, even in plants inoculated with B. japonicum E109.

Ecological Photodynamic Therapy: New trend to disrupt the intricate networks within tumor ecosystem Rumie Vittar, Natalia Belen; Lamberti, María Julia; Pansa, Maria Florencia; Vera, Renzo Emanuel; Rodriguez, Matias Exequiel; Cogno, Ingrid Sol; Milla Sanabria, Laura Natalia; Rivarola, Viviana As with natural ecosystems, species within the tumor microenvironment are connected by pairwise interactions (e.g. mutualism, predation) leading to a strong interdependence of different populations on each other. In this review we have identified the ecological roles played by each non-neoplastic population (macrophages, endothelial cells, fibroblasts) and other abiotic components (oxygen, extracellular matrix) directly involved with neoplastic development. A way to alter an ecosystem is to affect other species within the environment that are supporting the growth and survival of the species of interest, here the tumor cells; thus, some features of ecological systems could be exploited for cancer therapy. We propose a well-known antitumor therapy called photodynamic therapy (PDT) as a novel modulator of ecological interactions. We refer to this as “ecological photodynamic therapy.” The main goal of this new strategy is the improvement of therapeutic efficiency through the disruption of ecological networks with the aim of destroying the tumor ecosystem. It is therefore necessary to identify those interactions from which tumor cells get benefit and those by which it is impaired, and then design multitargeted combined photodynamic regimes in order to orchestrate non-neoplastic populations against their neoplastic counterpart. Thus, conceiving the tumor as an ecological system opens avenues for novel approaches on treatment strategies.

La Ciencia en los Cuentos: Análisis de las imágenes de científico en literatura juvenil de ficción; “Science in Tales”: Analysis of the Images of Scientist in Young People’s Fictional Literature Pujalte, Alejandro Patricio; Gangui, Alejandro; Aduriz Bravo, Agustin En el campo de los estudios referidos al carácter de las “imágenes de científico” presentes en la literatura de ficción, hemos puesto nuestro foco en una serie de cuentos producidos por estudiantes de escuela secundaria, con la intención de vincular algunos rasgos estereotípicos del científico especialmente frecuentes con los que subyacen a otras producciones culturales. Muchas de las representaciones son emergentes de una imagen de ciencia inadecuada desde el punto de vista de la enseñanza de las ciencias, pues se corresponde con un desinterés por las asignaturas científicas. Esto último, contribuiría a un estancamiento de la matrícula en las carreras de ciencia y tecnología en Iberoamérica en general y en especial en la Argentina; In the research field on the ‘images of scientists’ that appear in fictional literature, we focus on a set of tales produced by students of secondary school. Our aim is to connect some traits of the stereotypical scientist that appear in those texts with the traits underlying other cultural productions, since those productions may constitute the probable source of the stereotype. Many common representations of the scientist emerge from an image of science that is inadequate from the point of view of science teaching. It correlates to a lack of interest towards science courses. This lack of interest would contribute to stagnation in the number of students pursuing science and technology careers in Ibero-America in general and especially in Argentina.

Silsesquioxanes functionalized with one or two side-chain amino groups as coinitiators of camphorquinone in photoinitiated polymerization of methacrylate monomers Dell'erba, Ignacio Esteban; Asmussen, Silvana Valeria; Schroeder, Walter Fabian; Vallo, Claudia Ines Organotrialkoxysilanes (APS-PGE2) and (DAS-PGE3) were synthesized by reacting 1 mole of 3-(aminopropyl)triethoxysilane (APS) with 2 mole of phenylglycidylether (PGE) or 1 mole of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (DAS) with 3 mole of PGE respectively. Polyhedral oligomeric silsesquioxanes functionalized with bulky amino groups (ASSQO) were prepared by hydrolytic condensation of both APS-PGE2 and DAS-PGE3 using formic acid a a catalyst. The polymerization of methacrylate resins photoinitiated by camphorquinone (CQ) in combination with the synthesized ASSQO was investigated. The progress of monomer conversion vs. irradiation time showed that the CQ/ASSQO pair constitutes an efficient photoinitiator system because a fast reaction and high conversion result from 60 s irradiation at 600 mW/cm2. The mechanical behaviour of these systems in flexural and compressive tests was highly dependent on the structure of the ASSQO.

La Audacia y el Cálculo: las interpretaciones sobre el kirchnerismo de Beatriz Sarlo Goldstein, Ariel Alejandro Este ensayo se propone realizar un análisis de los posicionamientos políticos de la intelectual Beatriz Sarlo sobre el kirchnerismo, considerando recientes intervenciones públicas significativas de la autora. Entre las intervenciones analizadas, se ha elegido centrar el trabajo en las posiciones asumidas en La Audacia y el Cálculo, libro donde sistematiza su perspectiva sobre el fenómeno. Es en base al análisis de estas intervenciones que pretendemos realizar una breve reflexión sobre los modos de comprensión de la política argentina que se manifiestan en el análisis de la autora. Este artículo es similar a otro publicado previamente en la revista Papeles de Trabajo. La diferencia consiste en la incorporación de las sugerencias realizadas por los evaluadores de esta revista.

Guanaco (Lama guanicoe) mortality by entanglement in wire fences Rey, Andrés; Novaro, Andres Jose; Guichon, Maria Laura Wire fences are widely used in rangelands around the world and may have a negative impact on wildlife that varies among species and habitats. The guanaco (Lama guanicoe) is the largest Patagonian ungulate and though entanglement in wire fences is frequently reported, its impact on guanaco populations has not been previously evaluated. We estimated annual mortality rate of wild guanacos due to entanglement in wire fences and evaluated whether the frequency of entanglement was age-dependent in the two wire-fence designs traditionally used in Patagonian sheep ranches. We found that annual yearling mortality on fences (5.53%) was higher than adult mortality (0.84%) and was more frequent in ovine (93. cm high) than bovine (113. cm) fences. Most guanacos died entangled by their legs in the highest wire when trying to jump over the fence. Our results suggest that guanacos are more likely to die due to fence entanglement than ungulates studied in other regions. Indirect effects of wire fences should also be considered as they may act as semi-permeable barriers for guanaco populations. We suggest removal of unnecessary wire fences and replacement by guanaco-friendly fences, like high-tensile electric fences that may reduce mortality and barrier-effect on guanaco populations.

Crecimiento de cuatro familias de Pinus taeda en respuesta a la fertilización con nitrógeno y fósforo en el establecimiento de la plantación Faustino, Laura Inés; Bulfe, Nardia Maria Luján; Pinazo, Martín; Graciano, Corina Los individuos de Pinus taeda utilizados en plantaciones comerciales sobre suelos lateríticos de Argentina, presentan heterogeneidad en la respuesta a la fertilización con nitrógeno (N) y fósforo (P) durante el establecimiento. En general, las respuestas en crecimiento a la aplicación de P son positivas, mientras que la aplicación de N en forma de urea tiene un efecto perjudicial. El objetivo de este trabajo fue evaluar la respuesta a la fertilización con N y P de cuatro familias de P. taeda seleccionadas de un plan de mejoramiento genético, y determinar si la mejora genética permite obtener materiales con diferente respuesta a la adición de estos nutrientes. Los resultados demuestran que existe variabilidad entre las familias en el crecimiento en altura y diámetro del cuello, 8 y 16 meses luego de realizada la fertilización. Las familias de mayor tasa de crecimiento, respondieron positivamente a fertilización con P y no fueron afectadas por la fertilización con N. La familia que tuvo un crecimiento intermedio, no respondió a la adición de P y fue negativamente afectada por el N. La familia de menor crecimiento, respondió positivamente frente a la fertilización con P, pero fue negativamente afectada por el N. La mejora genética permite obtener genotipos con altas tasas de crecimiento que respondan en mayor magnitud a la fertilización con P y que no sean negativamente afectados por la adición de nitrógeno. Mediante el mejoramiento genético se puede evitar la penalidad en crecimiento que implica fertilizar con urea en el establecimiento, factor que facilitaría la utilización de esta práctica silvícola para recuperar o mantener la dotación de N de los sitios que están sujetos a repetidos ciclos de plantación y cosecha.

Functional groups and common pyrolysate products of Odontopteris cantabrica (index fossil for the Cantabrian Substage, Carboniferous) Zodrow, Eewin L; D`angelo, José Alejandro; Helleur, Robert; Simunek, Zbynek Foliage of the tree-fern Odontopteris cantabrica (Order: Medullosales) is considered a reliable plant-fossil index for the Cantabrian Substage (Carboniferous, 306 Ma). Compared are two preservation states from Canada (fossilized cuticles) and the Czech Republic (compression-cuticles), representing relatively uncommon and common preservation states, respectively. The main objective is deriving spectrochemical parameters for refining the taxonomic circumscription of the species. For the comparison, five sample categories (fossilized-cuticle, macerated fossilized-cuticle, compression, cuticle, and alkaline solution) are analyzed by methods of Fourier transform infrared (FTIR) spectroscopy, complemented by pyrolysis gas chromatography mass spectrometry (Py-GC/MS) for the Canadian sample. Variation of FTIR data in the latter sample is explained by the geochemical model for the formation of fossilized-cuticles by natural maceration.As a result, we propose a set of semi-quantitative FTIR ratios (spectral regions 1800-1000 cm-1 and 3000-2800 cm-1) as spectrochemical-taxonomic parameters for the index fossil: CH2/CH3, Al/Ox, C=O/C=C, C=O cont, Ar/Al and Ar/C=C. They contain molecular structural information related to aliphatic, aromatic and oxygen-bearing moieties. As expected, small overall spectrochemical differences occur, given converging preservation states, or similar fossilization trends for the cantabrica-plant inhabiting the Variscan Forelands of the ancestral Canada-Czech geographical regions. Some chemical differences occurred due to preservations in the sample categories (i.e., fossilized-cuticle and compression) with the oxygen-bearing structures, the length and branching of polymethylenic side chains and aromatic structures. A biomacropolymeric structure is confirmed by Py-GC/MS, and deduced for the Czech sample from the higher CH2/CH3 ratios.

Digestión anaeróbica mesofílica de la fracción orgánica de residuos sólidos domiciliarios. Reactor de alimentación semicontinua Bres, Patricia; Beily, María Eugenia; Crespo, Diana Este trabajo se enfocó en el monitoreo de un reactor anaeróbico semicontínuo, alimentado a velocidad de carga constante (VC= 1,1 kgSV m-3d-1), con la fracción orgánica de residuos sólidos domiciliarios y restos de verdulería durante 12 meses. Para ello se midió la producción de biogás y se analizaron en el efluente diferentes variables físicoquímicas y los indicadores de estabilidad (IE): alcalinidad parcial/total (AT) y ácidos grasos volátiles/AT. El rendimiento de biogás fue de 112 lkgSV-1en condiciones normales de temperatura y presión (CNPT), resultando este valor menor al obtenido con otros sustratos en el mismo reactor. Los IE mostraron un buen desarrollo del proceso anaeróbico durante todo el ensayo. Además, los porcentajes de remoción del 77% y 47,5% para la demanda química de oxígeno (DQO) y sólidos volatiles (SV) respectivamente, indicaron una eficiente degradación de la materia orgánica. Sin embargo los altos valores de DQO en el efluente, muestran la necesidad de ser tratado antes de su descarga.

Participación de los inmigrantes bolivianos en espacios específicos de la producción hortícola argentina; Migrations, Work and Agricultural Global Chains Benencia, Roberto Rodolfo La horticultura en fresco en la Argentina ha sido producida históricamente por mano de obra migrante; fuera ésta europea durante las primeras décadas del siglo XX o bien limítrofe a inicios del siglo XXI. En la actualidad, podría afirmarse que la corriente migratoria proveniente de Bolivia cuasi hegemoniza no sólo la oferta de mano de obra en dicha producción en casi todos los cinturones verdes del país, sino que, además, en algunos nichos clave domina los eslabones más importantes de esta cadena agroalimentaria. Desde finales del siglo XX e inicios del XXI, los inmigrantes bolivianos, apoyándose en la tradición de la inmigración europea, están hoy ejerciendo el predominio en la producción y en la comercialización de la horticultura en fresco. Si bien en otras provincias se registra la incorporación temprana de los inmigrantes bolivianos a la horticultura en el interior del país antes de los ’80 -cuando se detecta su llegada a Buenos Aires-, podría decirse que es a partir de esta última fecha que el fenómeno se generaliza y se expande, y en los últimos años -particularmente a partir de la crisis económico-social del 2002- se puede apreciar un fuerte avance de estas familias sobre el eslabón comercial de la cadena agroalimentaria de esta producción. En este trabajo se procurará describir el proceso histórico que posibilitó la ocurrencia del fenómeno a partir de la constitución de enclaves étnicos en distintos territorios hortícolas de la Argentina.; Fresh horticulture in Argentina has historically been produced by immigrant labor, from European countries during the first decades of the twentieth century or from borderline countries at the beginning of XXI century. At present, it could be argued that the migratory flow from Bolivia quasi hegemonizes not only the supply of labor in this production in almost all the green belts of the country, but also in some key niches dominates the most important links the food chain. Since the late twentieth and early twenty-first Bolivian immigrants, drawing on the tradition of European immigration, are now exerting dominance in the production and marketing of fresh horticulture. While other provinces have recorded the early incorporation of Bolivian immigrants in horticulture at the interior of the country before the ‘80s, when it detects its arrival in Buenos Aires, it can be argued that from the latter date the phenomenon is widespread and growing, and in recent years, particularly from the economic-social crisis of 2002, we can see a strong development of these families on the commercial link in the food chain of this production. In this paper we attempt to describe the historical process that allowed the occurrence of the phenomenon based on the formation of ethnic enclaves in different territories horticultural Argentina.