2,886 research outputs found

    The new urban paradigm

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    This paper argues in favor of a new urban model that harnesses the power that cities have to curb global warming. Such a model tackles fundamental management challenges in the energy, building and transport sectors to promote the growth of diverse and compact cities. Such a model is essential for meeting complex challenges in cities, such as promoting a cohesive social life and a competitive economic base while simultaneously preserving agricultural and natural systems crucial to soil, energy, and material resources. With most of the population living in urban areas, the G20 should recognize the key role that cities play in addressing global challenges such as climate change. Improved measures taken by cities should be an indispensable solution. The G20 Development Working Group, Climate Sustainability Working Group, and Energy Transitions Working Group should incorporate an urban approach to discussions related to climate change.Fil: Lanfranchi, Gabriel. Centro de Implementación de Políticas Públicas para la Equidad y el Crecimiento; ArgentinaFil: Herrero, Ana Carolina. Centro de Implementación de Políticas Públicas para la Equidad y el Crecimiento; ArgentinaFil: Rueda Palenzuela, Salvador. Agencia Ecología Urbana Barcelona; EspañaFil: Camilloni, Ines Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Bauer, Steffen. German Development Institute; Alemani

    First record of the invasive diatom Didymosphenia geminata (Lyngbye) Schmidt in a Patagonian Andean river of Argentina

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    The Futaleufú River, Argentina, was monitored monthly from June 2010 to August 2011, in order to detect the invasive diatom Didymosphenia geminata, which was previously observed in Chile. Plankton and periphyton samples were taken from 10 sites. Didymosphenia geminata was not found until late winter. In August 2010, the species was first detected at isolated points of the river but in spring and summer the algal coverage extended along several kilometers. The coverage of blooms, spread to deeper areas (pools) with varying depths, reached more than 2 m, invading epiphytic and epilithic substrates. In autumn the bloom diminished its coverage area and there were only small isolated patches. During the next winter, blooms were not observed until late August, when it was recorded again. The observations showed that D. geminata appeared, colonized and invaded the bed of the river at low flow situations in spring and summer and its blooms declined in autumn - when the flows increase - after having been dried in summer when flows were the lowest.Fil: Sastre, Alicia Viviana. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Santinelli, Norma Herminia. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Bauer, Gabriel A.. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel; ArgentinaFil: Ayesterán, M. Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; ArgentinaFil: Uyua, Noelia Mariel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew. Departamento de Biología. Laboratorio de Hidrobiología; Argentin

    An introduction to semiparametric function-on-scalar regression

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    Function-on-scalar regression models feature a function over some domain as the response while the regressors are scalars. Collections of time series as well as 2D or 3D images can be considered as functional responses. We provide a hands-on introduction for a flexible semiparametric approach for function-on-scalar regression, using spatially referenced time series of ground velocity measurements from large-scale simulated earthquake data as a running example. We discuss important practical considerations and challenges in the modelling process and outline best practices. The outline of our approach is complemented by comprehensive R code, freely available in the online appendix. This text is aimed at analysts with a working knowledge of generalized regression models and penalized splines

    Updating records of a threatened felid species of the Argentinian Patagonia: the Guigna Leopardus guigna (Molina, 1782) (Mammalia: Carnivora: Felidae) in Los Alerces National Park

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    El Guigna Leopardus guigna es un félido endémico de los Bosques Templados Valdivianos, en Argentina y Chile, y de la ecoregión Matorral Chileno en Chile. Este felino de pequeño tamaño (1.6-2.5 kg) es uno de los miembros menos conocidos de la Familia, y categorizado como Vulnerable a la extinción. En este trabajo, presentamos nuevos registros indudables en el Parque Nacional Los Alerces, provincia del Chubut, Argentina, el área Protegida más austral con registros fehacientes de la especie. El primero corresponde a un individuo encontrado muerto el 6 de junio de 2019 en la costa del río Frey, cerca del embalse Amutui Quimei. El segundo fue un individuo capturado casualmente en una trampa para visón Neovison vison el 7 de diciembre de 2019 en el lago Menéndez. Ambos registros ocurrieron en bosques de Nothofagus muy cerca de cursos de agua. Para mantener una población viable de Guigna a largo plazo, se deben establecer corredores entre las áreas protegidas, particularmente en hábitats dominados por la presencia y actividades humanas. Creemos que es necesario un mayor trabajo de campo en las áreas protegidas y entre ellas, para contribuir al conocimiento ecológico de esta especie.The Guigna Leopardus guigna is an endemic felid of the Valdivian Temperate Forests in Argentna and Chile, and of the Chilean Matorral ecoregion. It is a small-sized felid (1.6–2.5 kg), one of the least known wild felids, and categorized as Vulnerable to extncton. Here, we present two new reliable records in Los Alerces Natonal Park, Chubut Province, Argentna, the southernmost protected area, in which the species is present. The frst record is an individual found dead on 6 June 2019 on the bank of Frey River near Amutui Quimei Lake. The second record was an individual casually captured in an American Mink Neovison vison cage on 7 December 2019 near Menéndez Lake. Both records were in forested Nothofagus sites very nearby to watercourses. In order to maintain viable long-term Guigna populatons, corridors between protected areas should be established, partcularly in habitat dominated by human presence and actvites. We strongly recommend further feldwork in protected areas and between them to increase the knowledge about the distributon, habitat use, and ecology of the Guigna.Fil: Guerisoli, Maria de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Schiaffini, Mauro Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónica. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaFil: Bauer, Gabriel. Administración de Parques Nacionales; Argentin

    High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization

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    The liberalization of marijuana policies, including the legalization of medical and recreational marijuana, is sweeping the United States and other countries. Marijuana cultivation can have significant negative collateral effects on the environment that are often unknown or overlooked. Focusing on the state of California, where by some estimates 60% -- 70% of the marijuana consumed in the United States is grown, we argue that (a) the environmental harm caused by marijuana cultivation merits a direct policy response, (b) current approaches to governing the environmental effects are inadequate, and (c) neglecting discussion of the environmental impacts of cultivation when shaping future marijuana use and possession policies represents a missed opportunity to reduce, regulate, and mitigate environmental harm

    Role of Motility and Chemotaxis in Efficiency of Nodulation by <i>Rhizobium meliloti</i>

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    Spontaneous mutants of Rhizobium meliloti L5-30 defective in motility or chemotaxis were isolated and compared against the parent with respect to symbiotic competence. Each of the mutants was able to generate normal nodules on the host plant alfalfa (Medicago sativa), but had slightly delayed nodule formation, diminished nodulation in the initially susceptible region of the host root, and relatively low representation in nodules following co-inoculation with equal numbers of the parent. When inoculated in growth pouches with increasing dosages of the parental strain, the number of nodules formed in the initially susceptible region of the root increased sigmoidally, with an optimum concentration of about 105 to 106 bacteria/plant. The dose-response behavior of the nonmotile and nonchemotactic mutants was similar, but they required 10- to 30-fold higher concentrations of bacteria to generate the same number of nodules. The distribution frequencies of nodules at different positions along the primary root were very similar for the mutants and parent, indicating that reduced nodulation by the mutants in dose-response experiments probably reflects reduced efficiency of nodule initiation rather than developmentally delayed nodule initiation. The number of bacteria that firmly adsorbed to the host root surface during several hours of incubation was 5- to 20-fold greater for the parent than the mutants. The mutants were also somewhat less effective than their parent as competitors in root adsorption assays. It appears that motility and chemotaxis are quantitatively important traits that facilitate the initial contact and adsorption of symbiotic rhizobia to the host root surface, increase the efficiency of nodule initiation, and increase the rate of infection development.Facultad de Ciencias Exacta

    Late to post-Variscan basement segmentation and differential exhumation along the SW Bohemian Massif, central Europe

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    The exposed Variscan basement in central Europe is well-known for its complex structural and lithological architecture resulting from multiple deformation phases. We studied the southwestern margin of the Bohemian Massif, which is characterized by major and long-lived shear zones, such as the Pfahl and Danube shear zones, extending over > 100 km and initiated during Variscan tectonics. We integrated Bouguer gravity anomaly and lidar topographic data analyses and combined our results with available data and observations from low-temperature thermochronology, metamorphic grades, and the exposed granite inventory to detect patterns of basement block segmentation and differential exhumation. Three NW–SE-striking basement blocks are bordered by the Runding, Pfahl, and Danube shear zones from the northeast to the southwest. Basement block boundaries are indicated by abrupt changes in measured gravity patterns and metamorphic grades. By applying high-pass filters to gravity data in combination with lineament analysis, we identified a new NNW–SSE-striking tectonic structure (Cham Fault), which further segments known basement blocks. Basement blocks that are segmented by the Cham Fault differ in the abundance and spatial distribution of exposed late Variscan granites and are further characterized by variations in apparent thermochronological age data. Based on our observations and analyses, a differential exhumation and tectonic tilt model is proposed to explain the juxtaposition of different crustal levels. Block segmentation along the NW–SE-striking Pfahl and Runding shear zones most likely occurred prior, during, and after late orogenic granite emplacement at ca. 320 ± 10 Ma, as some of the granites are cross-cut by the shear zones, while others utilized these structures during magma ascent and emplacement. In contrast, activity and block segmentation along the Cham Fault occurred after granite emplacement as the fault sharply truncates the granite inventory. Our study provides evidence of intense and continuous fault activities during late and post-orogenic times and highlights the importance of tectonic structures in the exhumation and juxtaposition of different crustal levels and the creation of complex lithological patterns in orogenic terrains

    Ferroptosis in plants: regulation of lipid peroxidation and redox status

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    Regulated cell death (RCD) is an essential process that plays key roles along the plant life cycle. Unlike accidental cell death, which is an uncontrolled biological process, RCD involves integrated signaling cascades and precise molecular-mediated mechanisms that are triggered in response to specific exogenous or endogenous stimuli. Ferroptosis is a cell death pathway characterized by the iron-dependent accumulation of lipid reactive oxygen species. Although first described in animals, ferroptosis in plants shares all the main core mechanisms observed for ferroptosis in other systems. In plants as in animals, oxidant and antioxidant systems outline the process of lipid peroxidation during ferroptosis. In plants, cellular compartments such as mitochondria, chloroplasts and cytosol act cooperatively and coordinately to respond to changing redox environments. This particular context makes plants a unique model to study redox status regulation and cell death. In this review, we focus on our most recent understanding of the regulation of redox state and lipid peroxidation in plants and their role during ferroptosis.Fil: Distefano, Ayelen Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Lopez, Gabriel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Bauer, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Zabaleta, Eduardo Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Pagnussat, Gabriela Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin
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