40 research outputs found

    Fitosociología urbana I: la comunidad de Poa Annua L. y Coronopus didymus (L.) Sm. del centro de Argentina

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    Fitosociolog√≠a urbana I: La comunidad de Poa annua L. y Coronopus didymus (L.) Sm. del centro de Argentina. Se comentan algunos de los problemas asociados a la pr√°ctica fitosociol√≥gica en zonas urbanizadas y, en este contexto, se analiza la identidad de una comunidad de Poa annua L. y Coronopus didymus (L.) Sm. presente en la zona central de Argentina. Los inventarios realizados en las provincias de Mendoza, San Luis, C√≥rdoba y Buenos Aires, fueron comparados con los de las asociaciones relacionadas. Siguiendo el criterio para definir alianzas y asociaciones y utilizando Twinspan como m√©todo de an√°lisis objetivo, se consider√≥ a la comunidad como Bromo cathartici- Coronopodetum didymi ass. nova, vicariante neotropical, chaque√Īa y estrechamente relacionada con el Poo annuae- Coronopodetum didymi Carretero & Aguilella 1995, ib√©rico. Se propone la ampliaci√≥n del areal, como ne√≥fita, de la alianza Policarpion tetraphylli Rivas-Mart√≠nez 1975 hasta Am√©rica del Sur y se resalta la necesidad de incluir en sintaxones de amplia distribuci√≥n a los taxones frecuentes en h√°bitats antropozoog√©nicos, lo cual facilitar√≠a el desarrollo de la Fitosociolog√≠a urbana a lo largo del mundo

    La vegetación de ribera como indicadora de calidad ambiental en ríos serranos de la provincia de San Luis (Argentina)

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    The quality of the rivers can be analyzed using the characteristics of the vegetation of its banks. Nowadays, these habitats are being degraded at an accelerated rate by human disturbance. The aim of this study was to use the riparian vegetation of three rivers of the Sierra de San Luis (Argentina) as an indicator of the quality of aquatic environments. Fourteen phytosociological inventories were conducted in randomly selected sites on the banks of Potrero, El Volc√°n and El Trapiche rivers. In addition to the inventories, an anthropization index was calculated and a total of 23 alterations were identified. Each of these were assigned a value 0 (zero), 1 (low), 2 (medium) and 3 (high). These values were summed up to obtain a final score for each site. The results indicated that areas with higher anthropization possess a higher richness and coverage of invasive plants species, which are characteristic of disturbed sites. The site with the highest human disturbance was located on the banks of river El Volc√°n, while the lowest value was found in Potrero river. It can be inferred that invasive plants and the riparian communities‚Äô characteristics are good indicators of the environmental quality of these rivers.La calidad de los r√≠os se puede analizar utilizando las caracter√≠sticas de la vegetaci√≥n de sus orillas. Hoy en d√≠a, estos h√°bitats se est√°n degradando a un ritmo acelerado por la perturbaci√≥n humana. El objetivo de este estudio fue utilizar la vegetaci√≥n ribere√Īa de tres r√≠os de la Sierra de San Luis (Argentina) como indicador de la calidad de los ambientes acu√°ticos. Se realizaron catorce inventarios fitosociol√≥gicos en sitios seleccionados al azar en las orillas de los r√≠os Potrero, El Volc√°n y El Trapiche. Adem√°s de los inventarios, se calcul√≥ un √≠ndice de antropizaci√≥n y se identificaron un total de 23 alteraciones. A cada uno de estos se les asign√≥ un valor 0 (cero), 1 (bajo), 2 (medio) y 3 (alto). Estos valores se resumieron para obtener una puntuaci√≥n final para cada sitio. Los resultados indicaron que las √°reas con mayor antropizaci√≥n poseen una mayor riqueza y cobertura de especies de plantas invasoras, que son caracter√≠sticas de los sitios perturbados. El sitio con la perturbaci√≥n humana m√°s alta se ubic√≥ a orillas del r√≠o El Volc√°n, mientras que el valor m√°s bajo se encontr√≥ en el r√≠o Potrero. Se puede inferir que las plantas invasoras y las caracter√≠sticas de las comunidades ribere√Īas son buenos indicadores de la calidad ambiental de estos r√≠os

    Uma experiência educativa de nível inicial que promove a inclusão através de texturas e aromas vegetais

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    The present work describes the experience of the workshop "Plants, their textures and aromas that promote inclusion", within the framework of the Initial Education Conference at the Faculty of Human Sciences of the National University of San Luis. This content was selected taking into account the areas of deficit in initial level teaching and bachelor¬īs degree, among which include diversity and inclusion. The objectives of the workshop were to train teachers and students of the initial level in the teaching of botanical subjects, in relation to the recognition of plant species, through organoleptic properties, in order to promote pedagogical-didactic proposals that favor inclusion, enhancing cognitive skills. Addressing the study of plants, through multisensory teaching, favors the acquisition of knowledge in students, especially those who have some type of disability related to the sense organs and, particularly, visual disability. Among the resources used were specimens of plants, stereoscopic microscope and aromatheques. The procedures put into play in the different activities contemplated were the observation, identification, description and comparison of plants, using aromatheques as the main playful activity. As a way of closing the workshop, the reflections of the participants were recovered, who agreed that the proposal was creative and innovative. They considered that it constitutes an inclusive and significant strategy to bring together teachers and students at the initial level, a way of providing children with information about the environment that surrounds them.El presente trabajo describe la experiencia del taller ‚ÄúLas plantas, sus texturas y aromas que promueven la inclusi√≥n‚ÄĚ, en el marco de las Jornadas de Educaci√≥n Inicial en la Facultad de Ciencias Humanas de la Universidad Nacional de San Luis. Este contenido se seleccion√≥ teniendo en cuenta las √°reas de vacancia prioritarias en el profesorado y en la licenciatura en nivel inicial, que abarcan a la diversidad y a la inclusi√≥n. Los objetivos del taller fueron capacitar a docentes y estudiantes del nivel inicial en la ense√Īanza de temas bot√°nicos, en relaci√≥n al reconocimiento de especies vegetales, a trav√©s de propiedades organol√©pticas, a fin de propiciar propuestas pedag√≥gico-did√°cticas que favorezcan la inclusi√≥n, potenciando habilidades cognitivas. Abordar el estudio de las plantas, a trav√©s de la ense√Īanza multisensorial, favorece la adquisici√≥n de saberes en estudiantes, en especial, en aqu√©llos que presentan alg√ļn tipo de discapacidad relacionada con los √≥rganos de los sentidos y, particularmente, discapacidad visual. Entre los recursos usados se incluyeron ejemplares de vegetales, microscopio estereosc√≥pico y aromatecas. Los procedimientos puestos en juego en las diferentes actividades contemplaron: la observaci√≥n, identificaci√≥n, descripci√≥n y comparaci√≥n de plantas, usando aromatecas como actividad l√ļdica principal. A modo de cierre del taller, se recuperaron las reflexiones de los participantes, quienes consensuaron que la propuesta result√≥ creativa e innovadora. Consideraron que la misma constituye una estrategia inclusiva y significativa para acercar a docentes y estudiantes del nivel inicial, una forma de brindar a ni√Īos y ni√Īas informaci√≥n sobre el ambiente que los rodea.O presente trabalho descreve a experi√™ncia do workshop "Plantas, suas texturas e aromas que promovem a inclus√£o", no √Ęmbito da Confer√™ncia de Educa√ß√£o Inicial na Faculdade de Ci√™ncias Humanas da Universidade Nacional de San Luis. Esse conte√ļdo foi selecionado levando-se em considera√ß√£o as √°reas de d√©ficit na  forma√ß√£o de professores e no bacharelado de n√≠vel inicial, entre as quais a diversidade e a inclus√£o. Os objetivos da oficina foram capacitar professores e alunos do n√≠vel inicial no ensino de disciplinas bot√Ęnicas, em rela√ß√£o ao reconhecimento de esp√©cies vegetais, por meio de propriedades organol√©pticas, a fim de promover propostas did√°tico-pedag√≥gicas que favore√ßam a inclus√£o, aprimorando as habilidades cognitivas. Abordar o estudo das plantas, por meio do ensino multissensorial, favorece a aquisi√ß√£o de conhecimento nos alunos, principalmente aqueles que possuem algum tipo de defici√™ncia relacionada aos √≥rg√£os dos sentidos e, principalmente, a defici√™ncia visual. Entre os recursos foram usados esp√©cimes de plantas, microsc√≥pio estereosc√≥pico e aromatecas. Os procedimentos postos em jogo nas diferentes atividades contempladas: a observa√ß√£o, identifica√ß√£o, descri√ß√£o e compara√ß√£o de plantas, utilizando as aromatecas como principal atividade l√ļdica. Para concluir a experi√™ncia de workshop, foram recuperadas as reflex√Ķes dos participantes, que concordaram que a proposta era criativa e inovadora. Consideraram que se trata de uma estrat√©gia inclusiva e significativa para aproximar professores e alunos no n√≠vel inicial, uma forma de fornecer √†s crian√ßas informa√ß√Ķes sobre o ambiente que as cerca.  &nbsp

    The Effect of nest Size and Species Identity on Plant Selection in Acromyrmex Leaf-Cutting Ants

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    Leaf-cutting ants are key organisms because their role as primary consumers and potential agricultural pests. However, their foraging ecology was mostly studied as response of extrinsic factors such as climate and plant species traits. We evaluated the effects of intrinsic factors (i. e., nest size and species identity) on the foraging behavior in two species of Acromyrmex Mayr leaf-cutting ants. While large and small nests of A. lobicornis Emery showed similar feeding behavior, small nests of A. striatus Roger harvested a greater percent of the plant species available in their foraging area and showed a higher level of selectivity than larger nests. We discussed some probable reasons for this pattern. Our results highlight the relevance of intrinsic factors and species characteristics to explain changes in the foraging ecology of leaf-cutting ants as colony growth.Fil: Jofre, Laura Elizabeth. Universidad Nacional de San Luis; ArgentinaFil: Medina, Ana Irene. Universidad Nacional de San Luis; ArgentinaFil: Farji Brener, Alejandro Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Moglia, Marta Matilde. Universidad Nacional de San Luis; Argentin

    ¬ŅSe relaciona el patr√≥n de abundancia y distribuci√≥n de anuros con la estructura de las comunidades de plantas en h√°bitats acu√°ticos de la ciudad de San Luis (Argentina)?

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    The presence and permanence of anurans in urban ecosystems relies on the availability of aquatic habitats for reproduction, where vegetation is an important feature determining habitat selection. The aim of this study was to estimate species composition and relative abundance of anurans, based on vocalizations, and to explore relationships between these variables and composition and structure of vegetal communities and environmental variables (temperature, humidity and photoperiod) in urban aquatic habitats in San Luis city. Urban aquatic habitats were occupied by three anuran amphibian species, Leptodactylus mystacinus, Rhinella arenarum y Odontophrynus americanus, during their reproductive period. L. mystacinus and R. arenarum showed a similar and significantly higher than O. americanus relative abundance. The number of larvae fluctuated not significantly during the reproductive period and was not signifi cantly affected by environmental variables. Total relative abundance was significantly affected by photoperiod, but only the relative abundanceof R. arenarum varied temporally, being significantly higher on November than in February and March. Relative abundance of anurans (all species) was different between sites; this could be influenced by the perturbation degree and the structure and composition of plant communities, which are, at the same time, determined by environmental variables. Anurans were favored in urban areas away from the city center, where the exotic plants cover was low and the herb stratum was high and complex. Key words: amphibians, vegetation, species richness, urban ecosystems.La presencia y mantenimiento de anuros en ecosistemas urbanizados depende de la disponibilidad de h√°bitats acu√°ticos para su reproducci√≥n, en los que la vegetaci√≥n constituye uno de sus componentes m√°s conspicuos. El objetivo de este estudio fue estimar la composici√≥n espec√≠fica y la abundancia relativa de anuros a partir de vocalizaciones y explorar las relaciones de estas variables con la composici√≥n y estructura de comunidades vegetales y con variables ambientales (temperatura, humedad y fotoperiodo), en h√°bitats acu√°ticos urbanos de la ciudad de San Luis. Los cuerpos de agua urbanos estudiados fueron utilizados por tres especies de anfibios anuros, Leptodactylus mystacinus, Rhinella arenarum y Odontophrynus americanus, durante la √©poca de actividad reproductiva. L. mystacinus y R. arenarum mostraron una abundancia relativa similar y significativamente mayor que O. americanus. El n√ļmero de larvas fluctu√≥ durante el periodo de reproducci√≥n, aunque no de manera significativa, y no fue afectado por las variables ambientales. La abundancia relativa total de anuros fue significativamente afectada por el fotoperiodo, pero s√≥lo la abundancia relativa de R. arenarum vari√≥ temporalmente y fue significativamente m√°s alta en el mes de noviembre que en febrero y marzo. La abundancia relativa de todas las especies consideradas juntas fue diferente entre los sitios muestreados, lo que puede estar influenciado por el grado de perturbaci√≥n y por la estructura y composici√≥n de las comunidades vegetales, que son a su vez el reflejo de un conjunto de par√°metros ambientales. Los anuros se vieron favorecidos en las √°reas urbanas m√°s alejadas del centro, donde existi√≥ una menor cobertura de especies ex√≥ticas y donde el estrato herb√°ceo alcanz√≥ mayor altura y complejidad. Palabras clave: anfibios, vegetaci√≥n, riqueza de especies, ecosistemas urbanos

    Productividad y costos del raleo de algarrobo blanco (Prosopis alba) en Santiago del Estero, Argentina. Una primera aproximación

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    Se analizó la operación de raleo forestal en dos plantaciones experimentales de algarrobo blanco (Prosopis alba) en la zona de riego de la provincia de Santiago del Estero, Argentina, mediante un estudio de tiempos y movimientos para conocer la productividad operacional y los costos asociados al proceso de apeo con motosierra. Se midieron tiempos efectivos y operativos y se calculó volumen con corteza, eficiencia, productividad y costo directo del raleo. La muestra de 83 árboles completó un volumen abatido de 5,66 m3. El tiempo operativo promedio fue de 2,66 min/árbol, mientras que el tiempo efectivo medio fue de 1,36 min/árbol. Se halló gran variabilidad dimensional en los árboles de la muestra y un elevado grado de variabilidad en los tiempos de trabajo. Se verificó una fuerte correlación entre el tiempo efectivo de trabajo de la máquina y las variables diámetro y volumen de los árboles. La eficiencia operacional fue del 51 %. La productividad en el derribo fue de 1,54 m3/h (22,56 árboles/h). El costo unitario del raleo fue de 12,18 US/m3,equivalentea64,56/m3, equivalente a 64,56 /m3 (1 US=5,30 = 5,30 en mayo 2013). Los resultados para eficiencia, productividad y costo del raleo son preliminares y constituyen el primer antecedente en la zona.Operation of forest thinning in two experimental plantations of white mesquite (Prosopis alba) was analyzed in the irrigation area of the Santiago del Estero province in Argentina, through a study of time and motion for operational productivity and costs of chainsaw felling process. Effective and operative times were measured, and volume with bark, efficiency, productivity, and direct cost of thinning were calculated. The 83 sampled trees completed a volume of 5.66 m3 . The average operating time was 2.66 min/tree, while the average effective time was 1.36 min/tree. High dimensional variability of the sampled trees, and a high degree of variability in work times were found. A strong correlation between the uptime of the machine and the variables diameter and tree volume was verified. Operational efficiency was 51 %. Productivity in the felling was 1.54 m3 /h (22.56 tree/h). The cost of thinning was 12.18 US/m3,equivalentto64.56/m3 , equivalent to 64.56 /m3 (US1= 1 = 5.30 in may 2013). The results for efficiency, productivity, and cost of thinning are preliminary; and they are the first record in the area.EEA Santiago del EsteroFil: Coronel de Renolfi, Marta. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Forestales. Cátedra de Economía y Administración Forestal; ArgentinaFil: Cardona, Gabriela. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Forestales. Cátedra de Economía y Administración Forestal; ArgentinaFil: Moglia, Juana G. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Forestales. Cátedra de Dendrología; ArgentinaFil: Gomez, Adriana Teresita. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santiago del Estero; Argentin

    Exploring Alternative Futures in the Anthropocene

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    Many challenges posed by the current Anthropocene epoch require fundamental transformations to humanity’s relationships with the rest of the planet. Achieving such transformations requires that humanity improve its understanding of the current situation and enhance its ability to imagine pathways toward alternative, preferable futures. We review advances in addressing these challenges that employ systematic and structured thinking about multiple possible futures (futures-thinking). Over seven decades, especially the past two, approaches to futures-thinking have helped people from diverse backgrounds reach a common understanding of important issues, underlying causes, and pathways toward optimistic futures. A recent focus has been the stimulation of imagination to produce new options. The roles of futures-thinking in breaking unhelpful social addictions and in conflict resolution are key emerging topics. We summarize cognitive, cultural, and institutional constraints on the societal uptake of futures-thinking, concluding that none are insurmountable once understood

    Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons. A cross-ancestry genome-wide association meta-analysis of amyotrophic lateral sclerosis (ALS) including 29,612 patients with ALS and 122,656 controls identifies 15 risk loci with distinct genetic architectures and neuron-specific biology

    Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons. A cross-ancestry genome-wide association meta-analysis of amyotrophic lateral sclerosis (ALS) including 29,612 patients with ALS and 122,656 controls identifies 15 risk loci with distinct genetic architectures and neuron-specific biology
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