On the epoch of the Antikythera mechanism and its eclipse predictor Carman, Christian Carlos; Evans, James The eclipse predictor (or Saros dial) of the Antikythera mechanism provides a wealth of astronomical information and offers practically the only possibility for a close astronomical dating of the mechanism. We apply a series of constraints, in a sort of sieve of Eratosthenes, to sequentially eliminate possibilities for the epoch date. We find that the solar eclipse of month 13 of the Saros dial almost certainly belongs to solar Saros series 44. And the eclipse predictor would work best if the full Moon of month 1 of the Saros dial corresponds to May 12, 205 BCE, with the exeligmos dial set at 0. We also examine some possibilities for the theory that underlies the eclipse times on the Saros dial and find that a Babylonian-style arithmetical scheme employing an equation of center and daily velocities would match the inscribed times of day quite well. Indeed, an arithmetic scheme for the eclipse times matches the evidence somewhat better than does a trigonometric model.

Improving Survival and Growth of Planted Austrocedrus chilensis Seedlings in Disturbed Patagonian Forests of Argentina by Managing Understory Vegetation Pafundi, Leticia; Urretavizcaya, María Florencia; Defossé, Guillermo Emilio This study was aimed at determining, under field conditions, early interactions between planted cypress seedlings and their associated shrubs in a mesic area of Andean Patagonia and, in a nursery, the effects of increasing light availability on cypress performance when soil water was not a limiting factor. The field experiment was performed in a former cypress–coihue mixed forest (42°02′S, 71°33′W), which was replaced in the 1970s by a plantation of radiata pine. In 2005, 800 cypress seedlings were planted under maqui shrubs in a clear-cut area of the pine stand. In 2007, two treatments were set: no-competition treatment ([NCT] i.e., the surrounding aboveground biomass was removed) and competition treatment ([CT] i.e., without disturbance). The nursery experiment (42°55′S, 71°21′W) consisted of two groups: “shade” (grown under shade cloth) and “sun” (grown at full sun) cypress seedlings. After one growing season, seedling survival and stem growth (in height and diameter) were determined at both sites. Furthermore, the growth rate of leaves, stems, and roots was determined in the nursery. In the field experiment, height growth and survival in NCT were significantly greater than in CT, and a competition process occurred between cypress and surrounding shrubs. In the nursery, sun plants grew more in diameter and increased root weight more than shade plants. Results also showed that in mesic areas of Patagonia, decreasing competition and increasing light levels produced stouter seedlings better adapted to support harsh environmental conditions. Therefore, the removal of protecting shrubs could be a good management practice to improve seedling establishment.

First-order phase transition during displacement of amphiphilic biomacromolecules from interfaces by surfactant molecules Ettelaie, Rammile; Dickinson, Eric; Pugnaloni, Luis Ariel The adsorption of surfactants onto a hydrophobic interface, already laden with a fixed number of amphiphilic macromolecules, is studied using the self consistent field calculation method of Scheutjens and Fleer. For biopolymers having unfavourable interactions with the surfactant molecules, the adsorption isotherms show an abrupt jump at a certain value of surfactant bulk concentration. Alternatively, the same behaviour is exhibited when the number of amphiphilic chains on the interface is decreased. We show that this sudden jump is associated with a first-order phase transition, by calculating the free energy values for the stable and the metastable states at both sides of the transition point. We also observe that the transition can occur for two approaching surfaces, from a high surfactant coverage phase to a low surfactant coverage one, at sufficiently close separation distances. The consequence of this finding for the steric colloidal interactions, induced by the overlap of two biopolymer + surfactant films, is explored. In particular, a significantly different interaction, in terms of its magnitude and range, is predicted for these two phases. We also consider the relevance of the current study to problems involving the competitive displacement of proteins by surfactants in food colloid systems.

Threatened gastropods under the evolutionary genetic species concept: Redescription and new species of the genus Aylacostoma (Gastropoda: Thiaridae) from High Paraná River (Argentina-Paraguay) Vogler, Roberto Eugenio; Beltramino, Ariel Anibal; Peso, Juana Guadalupe; Rumi Macchi Z., Alejandra The genus Aylacostoma Spix, 1827, is mainly endemic to South America, and comprises about 30 nominal species, most of which were described based solely on conchological features following the typological approaches of most of the 19th and the mid-20th century authors. Here, we redescribe Aylacostoma chloroticum Hylton Scott, 1954, and describe Aylacostoma brunneum sp. nov. from the High Paraná River (Argentina-Paraguay) by means of morphological and molecular characters. Both are threatened species currently included into an ongoing ex situ conservation programme, as their habitats have disappeared because of damming and the filling up of the Yacyretá Reservoir in the early 1990s. We used DNA sequences from cytochrome b and cytochrome oxidase subunit I (COI) genes to estimate their genetic distances, and the COI sequences were also used to assess their specific status under the evolutionary genetic species concept by means of the K/θ method. Our results clearly demonstrate that both must be recognized as evolutionary genetic species, despite only minor differences in morphological characters other than in the shells.

Simultaneous enforcement of constraints at position and velocity levels in the nonsmooth generalized-α scheme Brüls, Olivier; Acary, Vincent; Cardona, Alberto This paper presents a formalism for the transient simulation of nonsmooth dynamic mechanical systems composed of rigid and flexible bodies, kinematic joints and frictionless contact conditions. The proposed algorithm guarantees the exact satisfaction of the bilateral and unilateral constraints both at position and velocity levels. Thus, it significantly differs from penalty techniques since no penetration is allowed. The numerical scheme is obtained in two main steps. Firstly, a splitting method is used to isolate the contributions of impacts, which shall be integrated with only first-order accuracy, from smooth contributions which can be integrated using a higher order scheme. Secondly, following the idea of Gear, Gupta and Leimkuhler, the equation of motion is reformulated so that the bilateral and unilateral constraints appear both at position and velocity levels. After time discretization, the equation of motion involves two complementarity conditions and it can be solved at each time step using a monolithic semi-smooth Newton method. The numerical behavior of the proposed method is studied and compared to other approaches for a number of numerical examples. It is shown that the formulation offers a unified and valid approach for the description of contact conditions between rigid bodies as well as between flexible bodies.

El tipo scratch-digger en dos armadillos (Dasypodidae, Xenarthra): ontogenia esqueletaria de las manos y variaciones de dígitos; The scratch-digger type in two armadillos (Dasypodidae, Xenarthra): ontogeny of the hand skeleton and digit variability Galliari, Fernando Carlos Los estudios comparativos y ontogenéticos referidos al esqueleto de las manos de los armadillos (Dasypodidae, Xenarthra), son escasos. En este trabajo se caracterizan los autopodios anteriores adultos en dos especies de armadillos actuales, Dasypus hybridus (Dasypodinae) y Chaetophractus villosus (Euphractinae). Se contrasta además su morfología con estadios previos al comienzo de la osificación esqueletaria. Se estudiaron 38 especímenes adultos, correspondientes a Chaetophractus villosus (n=34) y Dasypus hybridus (n=4). Se utilizaron además los autopodios anteriores de 2 fetos pertenecientes a las mismas especies que se seccionaron histológicamente con el fin de reconstruir la estructura cartilaginosa de la mano en desarrollo. Se realizó una descripción exhaustiva de la región carpal, metacarpal y falangeal del esqueleto adulto de ambas especies que luego se contrastó con el esqueleto preosteogénico de los fetos. En C. villosus hay una clara pentadactilia y el dedo III es el más robusto. En el carpo, los elementos tienden a una condición de diplartría, a relacionarse en mayor medida entre ellos y con el metacarpo. Así, esta especie es la que más se ajusta al tipo scratch-digger. Por su parte, en D. hybridus hay una tendencia a la reducción del dedo V, angostando la mano, y una relación de tamaño similar entre el dedo II y el III. A esta condición la acompañan modificaciones en el carpo que incluyen la reducción de los contactos entre carpales y entre ellos y los metacarpales. La región carpal fetal de C. villosus es muy similar a la del adulto y en ella ya están presentes los rasgos más sobresalientes. En el caso de D. hybridus, se pueden apreciar algunas diferencias con el esqueleto adulto. En este trabajo se han encontrado relictos del quinto dedo en D. hybridus. Así, se debería descartar, como un carácter diagnóstico de D. (H.) kappleri, la presencia de un quinto dedo, y a la vez realizar una revisión exhaustiva y extensiva al resto de las especies de Dasypus.; Ontogenetic and comparative studies on the hand skeleton of armadillos (Dasypodidae, Xenarthra) are scarce. In this paper adult autopodial skeleton of two species of extant armadillos, Dasypus hybridus (Dasypodinae) and Chaetophractus villosus (Euphractinae), are characterized. In addition, fetal morphology of the cartilaginous hands is compared to that of the bony adult hands. Adult specimens included 38 skeletons of C. villosus (n=34), and D. hybridus (n=4). Fetal cartilaginous hands were studied from serial histological sectioning of two specimens, belonging to D. hybridus and C. villosus. A comprehensive description of the adult hand skeleton, and a qualitative comparison with the fetal hand of both species is provided. The hand of C. villosus is clearly pentadactylous, being the third finger the larger one. In the carpus, elements are largely interlocked betwen them, and with the metacarpals. Therefore, this species fits well into the scratch-digger category. In contrast, D. hybridus shows a reduced five digit, narrowing the entire hand, and there is a similar size of digits II and III. This condition is tie to a series of modifications in the carpus, including a less contact among carpals and metacarpals. Fetal carpus of C. villosus is similar to adult skeleton, while in D. hybridus some differences are recorded. Considering that a relict of the fifth finger is present in D. hybridus, the presence of this finger as a diagnostic character of D. (Hyperoambon) kappleri should be discarded. In addition, a comprehensive revision of this character should be extensive to the rest of the species of Dasypus.

Tower of London: Planning development in children from 6 to 13 years of age Injoque Ricle, Irene; Barreyro, Juan Pablo; Calero, Alejandra Daniela; Burin, Debora Ines Executive Function is a multidimensional construct that includes a wide range of cognitive abilities that allow solving goal-directed behaviors efficiently. Its development begins in early childhood and continues through adolescence. A key aspect of Executive Function is planning, defined as the capacity to generate and organize the necessary step sequence to carry out a goal-directed behavior. The aim of this study was to assess the development of planning in children. The Tower of London task was used in 270 children aged 6, 8, 11, and 13 years. The results showed that the time required to generate and organize the plan to solve a goal-directed problem increases as the difficulty of the problem increases, and that older children need less time to solve problems with a certain level of difficulty than younger children F(15, 1330) = 8.787; MSE = 1.441; p <.01; η2 =.090. These results are in line with the findings that planning develops through childhood and even during the first years of adolescence.

Diagnóstico de (brechas de) desarrollo para Argentina: En "estado crítico" a fines de los 2000 Lopez, Andres Flavio; Niembro, Andrés Alberto; Ramos, Daniela Los enfoques y las metodologías aplicados hasta ahora al estudio de las desigualdades de desarrollo y bienestar entre países suelen limitarse a abordar el problema de las brechas de desarrollo a partir de la evaluación de unas pocas variables o dimensiones. El presente trabajo pretende aportar un diagnóstico de la situación de la Argentina hacia fines de los años 2000, pero en base a un enfoque más integral en el cual se desagrega el análisis en once áreas, buscando saber si los resultados obtenidos por el país en ellas son acordes con su nivel de ingreso per cápita.; So far, the approaches and methodologies applied to the analysis of inequalities in development and well-being between countries are usually limited to address the topic of development gaps through the evaluation of only a few variables or dimensions. The present work aims to provide a “diagnosis” of Argentinean development gaps in the late 2000s, by implementing a methodology in which eleven key areas are identified in order to learn whether Argentina’s outcomes in them are aligned with the country’s GDP per capital level. Results suggest that negative gaps still exist in most of the identified areas.

La Argentina y el problema de las drogas: Una propuesta para repensar el debate público Colombo Sierra, Agustín; Comini, Nicolás Matías; Del Percio, Enrique; Diamint, Rut; Fohrig, Alberto; López, Ernesto; López Chorne, Juan Estanislao; Martínez, Pablo; Paradiso, José; Sánchez Antelo, Raúl; Tibiletti, Luis; Tibiletti, María de la Paz; Tokatlian, Juan Gabriel; Ugarte, José Manuel; Vázquez Ocampo, José María La Argentina no puede ni debe asumir ante sí y el mundo la lógica fútil y fracasada de la "guerra contra las drogas". Los argentinos no estamos en guerra entre nosotros y no deberíamos aceptar pelear la guerra de otros.No es admisible ni conveniente reducir una problemática polifacética y compleja a una contienda bélica, por más que el cuadro que se enfrenta a este nivel y en este momento parezca acuciante. Hablar de guerra implica la administración de una fuerza armada aplicada de manera sistemática a alcanzar un resultado: vencer al enemigo mediante la aplicación de violencia militar. Desde luego, las narco actividades y sus consecuencias tienen una dimensión peligrosamente violenta que no es del caso minimizar. Pero reducir el abordaje y el tratamiento del problema meramente a esto es simplificarlo y unilateralizarlo, lo que probablemente no conduce al éxito, como se ha demostrado ya, entre otros, en los casos de Colombia y México.

La valoración de la vida, la subjetivación del embrión y el debate sobre el aborto: aportes desde una perspectiva crítica; The value of life, the embryo subjectivity and the debate about abortion: contributions from a critical perspective; A valoração da vida, a subjetivação do embrião e o debate sobre o aborto: aportes a partir de uma perspectiva crítica Moran Faundes, Jose Manuel Ferrucio El artículo analiza críticamente la forma en la que se planteado el debate ético y jurídico en torno al aborto, como un conflicto de derechos entre el embrión y la mujer, mostrando los modos en los que se ha construido la figura del embrión, como un sujeto susceptible de valoración moral y protección jurídica. En particular, se discute la posición que asume al cigoto indefectiblemente como un sujeto moral, por el hecho de poseer un genoma distinto del de sus progenitores, otorgándole un estatuto jurídico equivalente al de las mujeres. Así, se establece una crítica en torno al modo como esta posición, a través del uso de un lenguaje científico que se presenta como objetivo, ha tendido a invisibilizar las formas sociales y culturales que construyen la valoración de la vida.; This paper analyzes critically the way in which the ethical and legal debate about abortion is posed, as a conflict of rights between the embryo and the woman, showing the ways in which the figure of the embryo is built, as a subject susceptible of moral value and legal protection. In particular, the view sustaining the zygote as unfailing moral subject is discussed, by the fact of having a specific genome, different from progenitors, giving it a legal statute equivalent to women. Thus, a critique is stablished towards the way this view, through scientific language, presented as objective, has hold out to make invisible the cultural and social ways in which the value of life is built.; O artigo analisa criticamente a forma com a qual se propõe o debate ético e jurídico em torno do aborto, como um conflito de direitos entre o embrião e a mulher, mostrando os modos em que foi construída a figura do embrião, como um sujeito suscetível de valoração moral e proteção jurídica. Em particular, se discute a posição que assume o zigoto incontestavelmente como um sujeito moral, pelo fato de possuir um genoma distinto de seus progenitores, outorgando-lhe um estatuto jurídico equivalente ao das mulheres. Assim, se estabelece uma crítica em torno do modo como esta posição, por meio do uso de uma linguagem científica que se apresenta como objetivo, tendeu a tornar invisível as formas sociais e culturais que constroem a valoração da vida.

Experiencias y trayectorias educativas en la transferencia de conocimientos Díaz Ledesma, Lucas Gabriel; Mutuverria, Marcos Damián; Palazzolo, Fernando; Allegretti, Silvina Alicia Este artículo dialoga con el proyecto de investigacióna partir del cual consideramos pertinente analizar las experiencias de transferencia y las diferentes percepciones que tienen sobre ellas los y las jóvenes que se han graduado, en tanto investigadores/productores de conocimiento, en el marco de la realización de su tesis de grado para la finalización de carrera como proceso educativo, para enriquecer la mirada sobre cuáles son los vínculos comunicacionales, procesos de transferencia y aprendizajes significativos en los espacios educativos.

Senescence-Associated Vacuoles, a Specific Lytic Compartment for Degradation of Chloroplast Proteins? Carrión, Cristian Antonio; Martinez, Dana Ethel; Costa, M.lorenza; Guiamet, Juan José Degradation of chloroplasts and chloroplast components is a distinctive feature of leaf senescence. In spite of its importance in the nutrient economy of plants, knowledge about the mechanism(s) involved in the breakdown of chloroplast proteins is incomplete. A novel class of vacuoles, “senescence-associated vacuoles” (SAVs), characterized by intense proteolytic activity appear during senescence in chloroplast-containing cells of leaves. Since SAVs contain some chloroplast proteins, they are candidate organelles to participate in chloroplast breakdown. In this review we discuss the characteristics of SAVs, and their possible involvement in the degradation of Rubisco, the most abundant chloroplast protein. Finally, SAVs are compared with other extra-plastidial protein degradation pathways operating in senescing leaves.

Presence of c-kit positive cells in fetal and adult bovine forestomachs Marquez, Silvia Graciela; Galotta, Jorge Miguel; Gálvez, G. A.; Portiansky, Enrique Leo; Barbeito, Claudio Gustavo The interstitial cells of Cajal (ICC) have been reported to regulate gastrointestinal motility. We investigated the distribution and the morphological and morphometric characteristics of the immunohistochemical reaction against c-kit in the forestomachs of fetal, newborn and adult cows. The anti-c-kit reaction revealed different populations of ICC among age groups and organs. ICC were more numerous and smaller in fetuses. Larger ICC were identified in newborns, except for those in the rumen. During the earliest stages of development, ICC were abundant in the inner layer of the muscularis and were consistently associated with this layer. In all samples, ICC were found in the outer layer of the tunica muscularis. ICC were found between the two muscle layers in the omasum at all ages; however, they were identified only in the rumen of the adult. Our study demonstrated that ICC are present in the forestomach of bovines.

Paleo-Antarctic rainforest into the modern Old World tropics: The rich past and threatened future of the “southern wet forest survivors” Kooyman, Robert M.; Wilf, Peter; Barreda, Viviana Dora; Carpenter, Raymond J.; Jordan, Gregory J.; Sniderman, J. M. Kale; Allen, Andrew; Brodribb, Timothy J.; Crayn, Darren; Feild, Taylor S.; Laffan, Shawn W.; Lusk, Christopher H.; Rossetto, Maurizio; Weston, Peter H. Premise of study: Have Gondwanan rainforest floral associations survived? Where do they occur today? Have they survived continuously in particular locations? How significant is their living floristic signal? We revisit these classic questions in light of significant recent increases in relevant paleobotanical data. Methods: We traced the extinction and persistence of lineages and associations through the past across four now separated regions—Australia, New Zealand, Patagonia, and Antarctica—using fossil occurrence data from 63 well-dated Gondwanan rainforest sites and 396 constituent taxa. Fossil sites were allocated to four age groups: Cretaceous, Paleocene–Eocene, Neogene plus Oligocene, and Pleistocene. We compared the modern and ancient distributions of lineages represented in the fossil record to see if dissimilarity increased with time. We quantified similarity–dissimilarity of composition and taxonomic structure among fossil assemblages, and between fossil and modern assemblages. Key results: Strong similarities between ancient Patagonia and Australia confirmed shared Gondwanan rainforest history, but more of the lineages persisted in Australia. Samples of ancient Australia grouped with the extant floras of Australia, New Guinea, New Caledonia, Fiji, and Mt. Kinabalu. Decreasing similarity through time among the regional floras of Antarctica, Patagonia, New Zealand, and southern Australia reflects multiple extinction events. Conclusions: Gondwanan rainforest lineages contribute significantly to modern rainforest community assembly and often co-occur in widely separated assemblages far from their early fossil records. Understanding how and where lineages from ancient Gondwanan assemblages co-occur today has implications for the conservation of global rainforest vegetation, including in the Old World tropics.

Phenotypic evolution of an Atlantic Forest passerine (Xiphorhynchus fuscus): biogeographic and systematic implications Cabanne, Gustavo Sebastián; Trujillo Arias, Natalia; Calderón, Pablo Luciano Sebastian; d'Horta, Fernando M.; Miyaki, Cristina Y. We studied the phenotypic variation of the Atlantic Forest passerine Xiphorhynchus fuscus (Aves: Dendrocolaptidae) with the broad aim of addressing whether the history and type of forest affected the evolution of endemic taxa. We also tested whether the different subspecies and genetic lineages of X. fuscus could be considered full species. We collected plumage and body size measurements and, in combination with genetic data, used multivariate tests to evaluate the working hypotheses. Our results, combined with previous biogeographic analyses, indicate that vicariant events have been important determinants in the evolution of phenotypic characters of X. fuscus, once genetic isolation was complete. Our analysis also suggests that forest heterogeneity and ecotones are important factors in the early evolution of Atlantic Forest taxa, perhaps via divergent selection. Forest instability during the Pleistocene was critical in the evolution of phenotypic traits. We confirm that the subspecies atlanticus should be considered a full species. Other lineages or populations are also phenotypically differentiated but we do not suggest considering them as full species. They share high levels of gene flow and are part of a continuous latitudinal cline of phenotypic variation. Our study suggests that not all the historic events in the Atlantic Forest that affected the evolution of genetic lineages also influenced the evolution of phenotypic characters in the same direction and intensity. Undoubtedly, natural selection played a major role in the evolution of Atlantic Forest organisms.

Information retrieved from specimens at Natural History Collections can improve the quality of field-based ecological networks González Vaquero, Rocío Ana; Gravel, A. I.; Devoto, Mariano Numerous studies analyze the interactions between plants and their pollinators in ecological communities using a network approach. However, field studies rarely record all the interactions occurring in the field. In this sense Natural History Collections (NHCs) can provide information on interactions that may have been missed by field sampling. In this study we compare a network based on field sampling with a network based on data retrieved from specimens at NHCs, and we assess the degree to which these two sources of data are complementary. For this we used data available from a bee biodiversity study conducted in Southern Argentina for the South American bee genus Corynura (Halictidae: Augochlorini). Data on the floral associations of the specimens at NHCs were retrieved from the specimens’ labels, as the name of the plant species on which a given bee was captured is often recorded for many specimens at NHCs. Although field sampling recorded an unusually high number of insect-plant interactions, it misses some unique interactions present in the NHCs networks. Some structural properties of these networks are briefly analyzed, and usefulness and limitations of using NHCs data are discussed. We conclude that the information about insect-plant interactions extracted from NHCs could complement field-based data, especially in poorly sampled communities.

Testosterone cycle and regulation of reproductive events in the lizard Phymaturus punae (Liolaemidae) from the highlands of the Andes, Argentina. Boretto, Jorgelina Mariela; Fornes, Miguel Walter; Jahn, Graciela Alma; Acosta, Juan Carlos; Ibarguengoytía, Nora The genus Phymaturus, entirely viviparous and mostly herbivorous, inhabits the cold and 25 harsh environments of the Andean highlands of Argentina and Chile, and the Patagonian 26 steppe of Argentina. Phymaturus punae is a vulnerable lizard endemic to the Biosphere 27 Reserve San Guillermo (National Park and Provincial Reserve) in San Juan (Argentina) that 28 inhabits high altitudes of 3,100 to 4,200 m. The reproductive cycles of males and females of 29 P. punae have been described previously. Males perform a prenuptial and annual cycle, and 30 females reproduce once every two years. As a consequence, the adjustment in the timing of 31 males to the reproductive cycles of females must be very precise to ensure reproductive 32 success. We elucidate the time of mating and the asynchrony of males and females 33 reproductive events in P. punae based on endocrine and ultrastructural studies. Present 34 hormonal results support the idea that copulation in P. punae occurs at the end of the activity 35 season. Ultrastructural features observed in Sertoli and Leydig cells indicate that both types of 36 cells have the potential to synthesize steroid hormones, to support the spermatogenic cycle 37 and the mating period, respectively. In P. punae the cases of temporal asynchrony in steroid 38 activity, suggest that this mechanism must be important to start the spermatogenesis in spring, 39 supported by the steroid activity of Sertoli cells, since Leydig cells are inactive. Nevertheless 40 the asynchronic steroid mechanism seems to be more necessary in Phymaturus species with 41 continuous or postnuptial cycles, than in species with prenuptial cycles, like P. punae.

Una revisita al artículo 41 de la Constitución Nacional en diálogo con algunos debates contemporáneos del derecho ambiental Berros, María Valeria A veinte años de la última reforma constitucional se presenta la oportunidad para volver sobre el contenido del artículo 41 de la Constitución Nacional, incorporado dentro de los "Nuevos Derechos y Garantías". Esta revisita toma como punto de partida la construcción de una serie de reflexiones en torno a debates medulares y complejos, que exigen de aportes creativos al interior del derecho ambiental contemporáneo. Por un lado, se focaliza en elucidar la postura ética que subyace al contenido del artículo 41 y las nutridas discusiones que, en la actualidad, se desarrollan desde éticas que se desmarcan del antropocentrismo a partir de aportes del bio-centrismo y del eco-centrismo. Por el otro, el acento se coloca sobre el reciente proceso de consolidación del principio de no regresión en el derecho ambiental que, en nuestro ordenamiento jurídico, encuentra fundamento constitucional a partir del legado que debemos transmitir a las generaciones futuras.///La Revista de Derecho Ambiental constituye la más difundida publicación en Argentina, de carácter doctrinario e interdisciplinario, dedicada exclusivamente al derecho ambiental. Su comité consultivo nacional e internacional se encuentra compuesto por prestigiosos profesores e investigadores del área.

Condicionantes para la formación de capital productivo: Un análisis a partir de las pymes industriales de una economía regional; Productive capital formation constraints: an analysis based on regional economy SMEs Canafoglia, Eliana Celeste La dinámica industrial de los últimos años en la Argentina ha despertado un intenso debate en torno a los factores que explican (potencian y limitan) el desarrollo productivo. Es de interés en este trabajo discurrir por el sendero de la formación de capital como elemento clave en el proceso de reconstrucción del tejido industrial. Ahora bien, distinguir dicho proceso en agentes productivos pymes de subsectores industriales característicos de una economía regional contribuye a la definición de las restricciones presentes en términos de los medios disponibles y dificultades para afianzar dicho desarrollo.; The industrial dynamics of recent years in Argentina has aroused an intense debate about the factors that explain (enhance and limit) productive development. In this work we propose to go through the path of capital formation as a key element in the process of rebuilding the industrial base. However, distinguish this process in productive SME agents from characteristic industrial subsectors of a regional economy contributes to the definition of present constraints in terms of means available and difficulties in strengthen that development.

Effects of Larval Density and Habitat Drying on Developmental Success of Ochlerotatus albifasciatus (Diptera: Culicidae) in Urban Rain Pools: Evidence From Field and Experimental Studies Fischer, Sylvia Cristina; Sy, Victoria Elena; Campos, Raul Ernesto; Otero, Marcelo Javier Ochlerotatus albifasciatus (Macquart) (Diptera: Culicidae) larvae develop synchronously after rainfall events in ephemeral or temporary pools, where they occasionally attain very high abundance. The aims of the current study were to analyze the response of life history parameters such as daily larval mortality, time to pupation, and adult size of Oc. albifasciatus to increasing larval density under controlled conditions, and to analyze the relationships of daily larval mortality with density and environmental variables (drying rate, temperature, and season) in urban rain pools in Buenos Aires, Argentina. An exponential increase in mortality was observed at high larval densities under controlled conditions. Development times and adult size (wing length) differed between males and females, and were also affected by density. Development times extended for 0.36 d for each order of magnitude of increase in larval density, and wing length decreased 0.0021 mm per additional larva in 600 cm2. Larval density in the field varied from <1 larva per square meter to nearly 1100 larvae per square meter. Daily larval mortality values in the field were variable (0.02–0.91), positively related to the drying rate, and exhibited seasonal differences. No significant relation with larval density or temperature was found in the field. It remains to be established whether the density-independent mortality observed in this study is a generalized pattern of Oc. albifasciatus populations in Buenos Aires Province or a pattern restricted only to urban habitats.