Araucariácea nativa de argentina : estado de conservación y características del recurso forestal Araucaria araucana (Molina) K. Koch

La familia Araucariáceas está representada en Argentina por el género Araucaria; A. araucana se encuentra distribuida naturalmente al sur restringida a un clima extremo y aunque ha encontrado condiciones agroclimáticas únicas para prosperar, el grave estado de conservación en que se encuentran, peligra la perpetuidad no solo de ella sino también del ecosistema que la alberga, ya que contribuye a mantener un equilibrio ecológico único. El presente trabajo describe las características ecológicas de la especie y resume los aspectos más relevantes del estado de conservación y hábitat de este representante nativo de un género tan emblemático, ya que solo a través del conocimiento del patrimonio que poseemos es posible implementar acciones para su conservación, protección e integración de las comunidades locales en dicha actividades.The Araucariaceae family in Argentina is represented by the genus Araucaria; A. araucana is naturally distributed to the south restricted to extreme weather and although it has found unique growing conditions to thrive, severe condition they are in, endangered the perpetuity not only her but also the ecosystem that houses it, as it helps to maintain a unique ecological balance. This paper describes the ecological characteristics of the species and summarizes the most relevant aspects of the conservation status and habitat of this native representative of as emblematic genre; because only through knowledge of the heritage we have is possible to implement actions for their conservation, protection and integration of local communities in such activities.Fil: Goth, Silvia A.. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Fontana, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Luna, Claudia Verónica. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentin

Predators and dispersers: context-dependent outcomes of the interactions between rodents and a megafaunal fruit plant

Many plant species bear fruits that suggest adaptation to seed dispersal by extinct megafauna. Present-day seed dispersal of these megafaunal plants is carried out by rodents, which can act as predators or dispersers; whether this interaction is primarily positive or negative can depend on the context. Here, we parameterized a stochastic model using data from the field and experimental arenas to estimate the effect of rodents on the recruitment of Myrcianthes coquimbensis -an Atacama Desert shrub with megafaunal fruits- and examine whether environmental conditions can alter the sign and strength of these rodent-plant interactions. We show that the outcome of these interactions is context-dependent: in wet conditions seed removal by rodents negatively impacts the recruitment probability of M. coquimbensis; in contrast, in dry conditions, the interaction with rodents increases recruitment success. In all cases, the strength of the effect of rodents on the recruitment success was determined mainly by their role as dispersers, which could be positive or negative. This study demonstrates that by caching seeds, rodents can be effective dispersers of a megafaunal fruit plant, but that the sign and magnitude of their effect on recruitment changes as a function of the environmental context in which the interaction occursInstituto de Ecología y Biodiversidad, Chile | Ref. P05-002Universidad de La Serena, Chile | Ref. PT14122Ministerio de Ciencia e Innovación, España | Ref. PGC2018-096656-B-I00FONDECYT, Chile | Ref. 11140400Conicyt, Chile | Ref. AFB17000

Proyecto Chacarita : Conformación y estudio de una osteoteca de referencia para la ciudad de Buenos Aires

En el marco de las investigaciones básica en antropología forense, se observa una tendencia creciente, a nivel mundial, a evaluar y ajustar sus métodos y técnicas a las características de las poblaciones con las que trabaja. Es por ello que las osteotecas locales juegan un papel clave en los estudios forenses y bioantropológicos. En este contexto, el "Proyecto Chacarita" tiene por objetivo central la creación y estudio de una colección osteológica de referencia representativa de las características de la población actual de Buenos Aires. La conformación de una muestra de restos óseos humanos, recuperada bajo condiciones controladas e integrada exclusivamente por individuos de sexo y edad conocidos, permitirá, en el corto y mediano plazo, evaluar la validez de la aplicación en casos locales de los métodos "clásicos" de determinación de estos parámetros, los cuales fueron generados a partir del estudio de colecciones extranjeras. La creación de esta osteoteca permitirá, a largo plazo, desarrollar técnicas nuevas, específicas de la población de interés, realizar estudios antropobiológicos comparativos y formar recursos humanos especializados. Los objetivos propuestos por este proyecto se desarrollarán en dos etapas: la primera estará destinada a la conformación de la colección osteológica a partir de actividades de exhumación, acondicionamiento, bodegaje realizadas en el Cementerio Público de la Chacarita (C.A.B.A.). La segunda etapa se focalizará en los análisis específicos arriba mencionados. Actualmente se está trabajando con las autoridades de dicha institución en la redacción final del convenio marco que regula estas actividades. A su vez, el proyecto cuenta con la aprobación del Comité de Bioética del CEMIC, el cual evaluó la articulación de los objetivos con los aspectos metodológicos y éticos, y con las repercusiones que en el ámbito académico y social producirá la conformación y análisis de esta muestra. También se cuenta con el aval del Equipo Argentino de Antropología Forense (EAAF), la Cátedra de Medicina Legal y el Instituto J. J. Naón de la Facultad de Medicina (UBA). El Proyecto Chacarita se inició en septiembre de 2006, comenzando con las actividades de conformación y estabilización de la muestra, la cual cuenta hasta el momento con 115 individuos. Esta ponencia constituye la primera presentación en el ámbito académico del Proyecto. Se darán a conocer los objetivos generales de investigación, la metodología empleada, y los aspectos ético-legales, así como las características de la muestra conformada y las expectativas futuras de trabajo.Simposio: Avances y perspectivas en el manejo de colecciones osteológicas humanasAsociación de Antropología Biológica de la República Argentin

Insulin-like growth factor-I gene therapy reverses morphologic changes and reduces hyperprolactinemia in experimental rat prolactinomas

<p>Abstract</p> <p>Background</p> <p>The implementation of gene therapy for the treatment of pituitary tumors emerges as a promising complement to surgery and may have distinct advantages over radiotherapy for this type of tumors. Up to now, suicide gene therapy has been the main experimental approach explored to treat experimental pituitary tumors. In the present study we assessed the effectiveness of insulin-like growth factor I (IGF-I) gene therapy for the treatment of estrogen-induced prolactinomas in rats.</p> <p>Results</p> <p>Female Sprague Dawley rats were subcutaneously implanted with silastic capsules filled with 17-β estradiol (E₂) in order to induce pituitary prolactinomas. Blood samples were taken at regular intervals in order to measure serum prolactin (PRL). As expected, serum PRL increased progressively and 23 days after implanting the E₂capsules (Experimental day 0), circulating PRL had undergone a 3–4 fold increase. On Experimental day 0 part of the E₂-implanted animals received a bilateral intrapituitary injection of either an adenoviral vector expressing the gene for rat IGF-I (RAd-IGFI), or a vector (RAd-GFP) expressing the gene for green fluorescent protein (GFP). Seven days post vector injection all animals were sacrificed and their pituitaries morphometrically analyzed to evaluate changes in the lactotroph population. RAd-IGFI but not RAd-GFP, induced a significant fall in serum PRL. Furthermore, RAd-IGFI but not RAd-GFP significantly reversed the increase in lactotroph size (CS) and volume density (VD) induced by E₂treatment.</p> <p>Conclusion</p> <p>We conclude that IGF-I gene therapy constitutes a potentially useful intervention for the treatment of prolactinomas and that bioactive peptide gene delivery may open novel therapeutic avenues for the treatment of pituitary tumors.</p

A cryopreservation protocol for immature zygotic embryos of species of Ilex (Aquifoliaceae)

ABSTRACT: Tropical Ilex species have recalcitrant seeds. This work describes experiments demonstrating the feasibility of long-term conservation of Ilex brasiliensis, I. brevicuspis, I. dumosa, I. intergerrima, I. paraguariensis, I. pseudoboxus, I. taubertiana, and I. theezans through cryopreservation of zygotic rudimentary embryos at the heart developmental stage. The embryos were aseptically removed from the seeds and precultured (7 days) in the dark, at 27± 2ºC on solidified (0.8% agar) 1/4MS medium, [consisting of quarterstrength salts and vitamins o

Impact of Simultaneous Exposure to Arboviruses on Infection and Transmission by Aedes aegypti Mosquitoes

The recent emergence of both chikungunya and Zika viruses in the Americas has significantly expanded their distribution and has thus increased the possibility that individuals may become infected by more than one Aedes aegypti-borne virus at a time. Recent clinical data support an increase in the frequency of coinfection in human patients, raising the likelihood that mosquitoes could be exposed to multiple arboviruses during one feeding episode. The impact of coinfection on the ability of relevant vector species to transmit any of these viruses (that is, their vector competence) has not been determined. Thus, we here expose Ae. aegypti mosquitoes to chikungunya, dengue-2 or Zika viruses, both individually and as double and triple infections. Our results show that these mosquitoes can be infected with and can transmit all combinations of these viruses simultaneously. Importantly, infection, dissemination and transmission rates in mosquitoes are only mildly affected by coinfection

Impact of Extrinsic Incubation Temperature on Natural Selection During Zika Virus Infection of Aedes Aegypti and Aedes Albopictus

Arthropod-borne viruses (arboviruses) require replication across a wide range of temperatures to perpetuate. While vertebrate hosts tend to maintain temperatures of approximately 37°C-40°C, arthropods are subject to ambient temperatures which can have a daily fluctuation of \u3e 10°C. Temperatures impact vector competence, extrinsic incubation period, and mosquito survival unimodally, with optimal conditions occurring at some intermediate temperature. In addition, the mean and range of daily temperature fluctuations influence arbovirus perpetuation and vector competence. The impact of temperature on arbovirus genetic diversity during systemic mosquito infection, however, is poorly understood. Therefore, we determined how constant extrinsic incubation temperatures of 25°C, 28°C, 32°C, and 35°C control Zika virus (ZIKV) vector competence and population dynamics within Aedes aegypti and Aedes albopictus mosquitoes. We also examined fluctuating temperatures which better mimic field conditions in the tropics. We found that vector competence varied in a unimodal manner for constant temperatures peaking between 28°C and 32°C for both Aedes species. Transmission peaked at 10 days post-infection for Aedes aegypti and 14 days for Aedes albopictus. Conversely, fluctuating temperature decreased vector competence. Using RNA-seq to characterize ZIKV population structure, we identified that temperature alters the selective environment in unexpected ways. During mosquito infection, constant temperatures more often elicited positive selection whereas fluctuating temperatures led to strong purifying selection in both Aedes species. These findings demonstrate that temperature has multiple impacts on ZIKV biology, including major effects on the selective environment within mosquitoes

Mosquitoes Transmit Unique West Nile Virus Populations During Each Feeding Episode

Arthropod-borne viruses (arboviruses), such as Zika virus, chikungunya virus, and West Nile virus (WNV), pose continuous threats to emerge and cause large epidemics. Often, these events are associated with novel virus variants optimized for local transmission that first arise as minorities within a host. Thus, the conditions that regulate the frequency of intrahost variants are important determinants of emergence. Here, we describe the dynamics of WNV genetic diversity during its transmission cycle. By temporally sampling saliva from individual mosquitoes, we demonstrate that virus populations expectorated by mosquitoes are highly diverse and unique to each feeding episode. After transmission to birds, however, most genetic diversity is removed by strong purifying selection. Further, transmission of potentially mosquito-adaptive WNV variants is strongly influenced by genetic drift in mosquitoes. These results highlight the complex evolutionary forces a novel virus variant must overcome to alter infection phenotypes at the population level

Testing in the incremental design and development of complex products

Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested

Anatomía dentaria interna y externa de premolares superiores en una población argentina

Los rasgos dentales discretos constituyen un importante campo de investigación para la odontologíay la antropología dental. El conocimiento de las variaciones de la morfología dentaria permiteobtener resultados predecibles en la práctica endodóntica y contribuye tanto a la evaluaciónde las biodistancias como al proceso de identificación de personas desaparecidas. El objetivo deesta presentación es analizar la diversidad en el número de raíces y en la configuración anatómicainterna de primeros y segundos premolares superiores en una muestra de la población argentina,utilizando tomografía cone-beam. Se incluyeron 282 piezas dentarias, 156 (55%) de mujeres y 126(45%) de varones. Los datos se describieron mediante frecuencias absolutas, porcentajes e intervalosde confianza al 95% estimados mediante el método score. Para evaluar la asociación se utilizóla prueba exacta de Fisher con simulación Monte Carlo. La morfología más representada para losprimeros premolares correspondió a dos conductos (54%) y para los segundos premolares, a unconducto (58,5%), en los tres tercios radiculares. Se identificaron asociaciones significativas entre elnúmero de raíces y la pieza dentaria, y entre el grupo dentario y la morfología; no hubo asociaciónsignificativa en la cantidad de raíces y en la configuración interna, en relación con el lado. En conclusión,las variantes más representadas fueron las dos raíces y dos conductos en primeros premolares,y una raíz y un conducto en segundos premolares. La identificación de estas tendencias sonun aporte para la caracterización de la morfología dental de una población argentina.Fil: Consoli Lizzi, E.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Chaintiou Piorno, R.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Cimenton, C.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Aranda, Claudia Marcela. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Gualtieri, A.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Luna, Leandro Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; ArgentinaFil: Rodríguez, P.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaXV Jornadas Nacionales de Antropología BiológicaLa PlataArgentinaAsociación de Antropología Biológica Argentin