2,666 research outputs found

    Short-Interval, Severe Wildfires Alter Saproxylic Beetle Diversity in Andean Araucaria Forests in Northwest Chilean Patagonia

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    The occurrence of short-interval, severe wildfires are increasing drastically at a global scale, and appear as a novel phenomenon in areas where fire historically returns in large time lapses. In forest ecosystems, these events induce drastic changes in population dynamics, which could dramatically impact species diversity. Here, we studied the effect on diversity of recent short-interval, severe wildfires (SISF), which occurred in rapid succession in the summers of 2002 and 2015 in Chilean Northern Patagonian Araucaria–Nothofagus forests. We analyzed the diversity of deadwood-dependent (i.e., saproxylic) and fire-sensitive beetles as biological indicators across four conditions: 2002-burned areas, 2015-burned areas, SISF areas (i.e., burned in 2002 and again in 2015), and unburned areas. Saproxylic beetles were collected using window traps in 2017 to 2019 summer seasons. To investigate the mechanisms underpinning the fire-related disturbance of the assemblage, we evaluated the effects of post-fire habitat quality (e.g., dead wood decomposition) and quantity (e.g., burned dead wood volume and tree density) on the abundances and species richness of the entire assemblage and also multiple trophic groups. Compared with the unburned condition, SISF drastically reduced species richness, evenness, and Shannon’s diversity and altered the composition of the saproxylic beetle assemblages. The between-condition variation in composition was accounted for by a species replacement (turnover) between SISF and 2015-burned areas, but both species replacement and extinction (nestedness) between SISF and unburned areas. Dead wood decomposition and tree density were the variables with the strongest effects on the abundance and species richness of the entire saproxylic beetle assemblage and most trophic groups. These results suggest that SISF, through degraded habitat quality (dead wood decomposition) and quantity (arboreal density), have detrimental impacts on diversity and population dynamics of saproxylic beetle assemblages. Therefore, habitat loss is a central mechanism underpinning fire-related biodiversity loss in these forest ecosystems.F.T. (Francisco Tello) was financially supported by CONICYT doctoral scholarship no. 21171980. F.T. (Francisco Tello), M.E.G., and A.L. were financially supported by ANID/FONDAP center no. 15110009 (CR2). M.E.G. was financially supported by FONDECYT grant no. 1201528. N.V. was financially supported by FONDECYT grants no. 1190529, no. 1181300, and FONDAP center no. 15150003 (IDEAL)

    Antifungal activities of the essential oil of five species of Juniperus from Argentina

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    The chemical composition of the leaf oils of five Juniperus species (Juniperus sabina L., Juniperus communis Lam., Juniperus scopulorum Sarg., Juniperus virginiana L., Juniperus chinensis L., Cupressaceae) was determined by co-chromatography with authentic samples, GC-MS and Kováts retention indices. Sabinene was the most abundant component in the oils of Juniperus from western Patagonia Argentina. However, limonene and germacrene B constituted 25.1% and 11.5% of the oil of J. sabina. J. virginiana showed high concentration of alpha-humulene and limonene (31.4 and 15.9% respectively), while isobornyl acetate and germacrene B were also the main compounds of J. chinensis. Essential oils extracted of Juniperus were evaluated in vitro for their efficacy against Fusarium verticillioides, Aspergillus flavus, Aspergillus parasiticus, Candida albicans and Rhodotorula infection. Candida albicans was not inhibited for the essential oils of Juniperus. However, F. verticillioides, A. flavus, A. parasiticus and Rhodotorula were inhibited for these oils.Juniperus species (Juniperus sabina L., Juniperus communis Lam., Juniperus scopulorum Sarg., Juniperus virginiana L., Juniperus chinensis L., Cupressaceae) was determined by co-chromatography with authentic samples, GC-MS and Kováts retention indices. Sabinene was the most abundant component in the oils of Juniperus from western Patagonia Argentina. However, limonene and germacrene B constituted 25.1% and 11.5% of the oil of J. sabina. J. virginiana showed high concentration of alpha-humulene and limonene (31.4 and 15.9% respectively), while isobornyl acetate and germacrene B were also the main compounds of J. chinensis. Essential oils extracted of Juniperus were evaluated in vitro for their efficacy against Fusarium verticillioides, Aspergillus flavus, Aspergillus parasiticus, Candida albicans and Rhodotorula infection. Candida albicans was not inhibited for the essential oils of Juniperus. However, F. verticillioides, A. flavus, A. parasiticus and Rhodotorula were inhibited for these oils.Fil: Dambolena, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Meriles, Jose Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: López, Abel Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Gallucci, Mauro Nicolas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; ArgentinaFil: González, Silvia Beatriz. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Comodoro; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Guerra, Pedro E.. Universidad Nacional de la Patagonia "san Juan Bosco". Facultad de Ingeniería - Sede Esquel. Departamento de Ingeniería Forestal. Cátedra de Suelos Forestales; ArgentinaFil: Bruno, Antonella. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Zunino, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

    From flax to wool: spinning at Cabezo Redondo (Villena, Alicante) and changes in textile production during the Bronze Age

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    En este trabajo se analiza el importante conjunto de fusayolas procedentes del asentamiento de Cabezo Redondo, recuperadas tanto en las excavaciones antiguas de José María Soler como en las desarrolladas en las últimas décadas. El número elevado de ejemplares, todas ellas correspondientes a contextos del Bronce Tardío (c. 1600-1250 cal BC), y sus características (diversidad en materiales utilizados, tipología y peso) permiten inferir una actividad de hilado intensa distribuida a lo largo del poblado, así como importantes transformaciones en la producción textil con respecto a los momentos previos. Entre los cambios principales se encontrarían la continuidad de la tradición de hilado de fibras vegetales como el lino y, sobre todo, la consolidación de nuevas técnicas de hilado y la generalización del hilado de fibras de origen animal como la lana. En definitiva, a partir del estudio de estos artefactos, sumado al análisis de otros indicadores, se propone el desarrollo de una producción textil amplia y diversa, en sintonía con lo que sucedido en otras áreas de Europa y el Mediterráneo durante la segunda mitad del II milenio cal BC.This paper analyses the important set of spindle whorls from the Cabezo Redondo settlement, recovered both in the ancient excavations of José María Soler and in the excavations carried out in recent decades. The large number of tools, all of them corresponding to Late Bronze Age contexts (c. 1600-1250 cal BC), and their characteristics -diversity in materials used, typology and weight- allow us to infer an intense spinning activity distributed throughout the settlement, as well as important transformations in textile production with respect to previous times. The main changes include the continuity of the tradition of spinning bast fibres such as flax and, above all, the consolidation of new spinning techniques and the generalisation of the spinning of animal fibres such as wool. In short, the study of these artefacts, together with the analysis of other indicators, suggests the development of a wide and diverse textile production, in line with what happened in other areas of Europe and the Mediterranean during the second half of the 2nd millennium BC

    Attenuation Factor Estimation of Direct Normal Irradiance Combining Sky Camera Images and Mathematical Models in an Inter-Tropical Area

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    Nowadays, it is of great interest to know and forecast the solar energy resource that will be constantly available in order to optimize its use. The generation of electrical energy using CSP (concentrated solar power) plants is mostly affected by atmospheric changes. Therefore, forecasting solar irradiance is essential for planning a plant’s operation. Solar irradiance/atmospheric (clouds) interaction studies using satellite and sky images can help to prepare plant operators for solar surface irradiance fluctuations. In this work, we present three methodologies that allow us to estimate direct normal irradiance (DNI). The study was carried out at the Solar Irradiance Observatory (SIO) at the Geophysics Institute (UNAM) in Mexico City using corresponding images obtained with a sky camera and starting from a clear sky model. The multiple linear regression and polynomial regression models as well as the neural networks model designed in the present study, were structured to work under all sky conditions (cloudy, partly cloudy and cloudless), obtaining estimation results with 82% certainty for all sky types

    CANDELS: The progenitors of compact quiescent galaxies at z~2

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    We combine high-resolution HST/WFC3 images with multi-wavelength photometry to track the evolution of structure and activity of massive (log(M*) > 10) galaxies at redshifts z = 1.4 - 3 in two fields of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). We detect compact, star-forming galaxies (cSFGs) whose number densities, masses, sizes, and star formation rates qualify them as likely progenitors of compact, quiescent, massive galaxies (cQGs) at z = 1.5 - 3. At z > 2 most cSFGs have specific star-formation rates (sSFR = 10^-9 yr^-1) half that of typical, massive SFGs at the same epoch, and host X-ray luminous AGN 30 times (~30%) more frequently. These properties suggest that cSFGs are formed by gas-rich processes (mergers or disk-instabilities) that induce a compact starburst and feed an AGN, which, in turn, quench the star formation on dynamical timescales (few 10^8 yr). The cSFGs are continuously being formed at z = 2 - 3 and fade to cQGs by z = 1.5. After this epoch, cSFGs are rare, thereby truncating the formation of new cQGs. Meanwhile, down to z = 1, existing cQGs continue to enlarge to match local QGs in size, while less-gas-rich mergers and other secular mechanisms shepherd (larger) SFGs as later arrivals to the red sequence. In summary, we propose two evolutionary scenarios of QG formation: an early (z > 2), fast-formation path of rapidly-quenched cSFGs that evolve into cQGs that later enlarge within the quiescent phase, and a slow, late-arrival (z < 2) path for SFGs to form QGs without passing through a compact state.Comment: Submitted to the Astrophysical Journal Letters, 6 pages, 4 figure

    Behavioral immune landscapes of inflammation.

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    Transcriptional or proteomic profiling of individual cells have revolutionized interpretation of biological phenomena by providing cellular landscapes of healthy and diseased tissues. These approaches, however, fail to describe dynamic scenarios in which cells can change their biochemical properties and downstream “behavioral” outputs every few seconds or minutes. Here, we used 4D live imaging to record tens to hundreds of morpho-kinetic parameters describing the dynamism of individual leukocytes at sites of active inflammation. By analyzing over 100,000 reconstructions of cell shapes and tracks over time, we obtained behavioral descriptors of individual cells and used these high-dimensional datasets to build behavioral landscapes. These landscapes recognized leukocyte identities in the inflamed skin and trachea, and inside blood vessels uncovered a continuum of neutrophil states, including a large, sessile state that was embraced by the underlying endothelium and associated with pathogenic inflammation. Behavioral in vivo screening of thousands of cells from 24 different mouse mutants identified the kinase Fgr as a driver of this pathogenic state, and genetic or pharmacological interference of Fgr protected from inflammatory injury. Thus, behavioral landscapes report unique biological properties of dynamic environments at high cellular, spatial and temporal resolution.pre-print4302 K

    Wildfire management in Mediterranean-type regions: paradigm change needed

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    PerspectiveDuring the last decades, climate and land use changes led to an increased prevalence ofmegafires in Mediterranean-type climate regions (MCRs).Here, we argue that current wildfire management policies in MCRs are destined to fail.Focused on fire suppression, these policies largely ignore ongoing climate warming and landscape-scale buildup of fuels.The result is a ‘firefighting trap’ that contributes to ongoing fuel accumulation precluding suppression under extreme fire weather, and resulting in more severe and larger fires.We believe that a ‘business as usual’ approach to wildfire in MCRs will not solve the fire problem, and recommend that policy and expenditures be rebalanced between suppression and mitigation of the negative impacts of fire.This requires a paradigm shift: policy effectiveness should not be primarily measured as a function of area burned (as it usually is), but rather as a function of avoided socio-ecological damage and lossinfo:eu-repo/semantics/publishedVersio

    Actividad antifúngica del aceite esencial de cinco especies de Juniperus de Argentina

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    The chemical composition of the leaf oils of five Juniperus species (Juniperus sabina L., Juniperus communis Lam., Juniperus scopulorum Sarg., Juniperus virginiana L., Juniperus chinensis L., Cupressaceae) was determined by co-chromatography with authentic samples, GC-MS and Kováts retention indices. Sabinene was the most abundant component in the oils of Juniperus from western Patagonia Argentina. However, limonene and germacrene B constituted 25.1% and 11.5% of the oil of J. sabina. J. virginiana showed high concentration of alpha-humulene and limonene (31.4 and 15.9% respectively), while isobornyl acetate and germacrene B were also the main compounds of J. chinensis. Essential oils extracted of Juniperus were evaluated in vitro for their efficacy against Fusarium verticillioides, Aspergillus flavus, Aspergillus parasiticus, Candida albicans and Rhodotorula infection. Candida albicans was not inhibited for the essential oils of Juniperus. However, F. verticillioides, A. flavus, A. parasiticus and Rhodotorula were inhibited for these oils.La composición de los aceites esenciales de la hoja de cinco especies de Juniperus (Juniperus sabina L., Juniperus communis Lam., Juniperus scopulorum Sarg., Juniperus virginiana L., Juniperus chinensis L., Cupressaceae), se determinó mediante una co-cromatografía con muestras auténticas de dos columnas de diferente polaridad, CG-EM y los índices de retención de Kovats. El sabineno fue el componente más abundante en los aceites de Juniperus del oeste de la Patagonia Argentina. Sin embargo, el limoneno y el germacreno B son otros componentes importantes del aceite esencial de J. sabina con el 25,1% y 11,5% respectivamente. En J. virginiana el alfa-humuleno y el limoneno (con el 31,4% y 15.9% respectivamente) mostraron ser también importantes, mientras que el acetato de isobornilo y el germacreno B fueron también los principales componentes de la J. chinensis. Los aceites esenciales extraídos de Juniperus se evaluaron in vitro para determinar su eficacia contra Fusarium verticillioides, Aspergillus flavus, Aspergillus parasiticus, Candida albicans y Rhodotorula. Candida albicans no se inhibió por la acción de los aceites esenciales de Juniperus. Sin embargo, F. verticillioides, A. flavus, A. parasiticus y Rhodotorula fueron inhibidos

    Dependence on plasma shape and plasma fueling for small ELM regimes in TCV and ASDEX Upgrade

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    Within the EUROfusion MST1 Work Package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two conditions are fulfilled at the same time. Firstly, the plasma density at the separatrix must be large enough (ne,sep/nG ∼ 0.3), leading to a pressure profile flattening at the separatrix, which stabilizes type-I ELMs. Secondly, the magnetic configuration has to be close to a Double Null (DN), leading to a reduction of the magnetic shear in the extreme vicinity of the separatrix. As a consequence, its stabilizing effect on ballooning modes is weakened.EURATOM 63305

    State recognition for ‘contested languages’: a comparative study of Sardinian and Asturian, 1992–2010

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    While the idea of a named language as a separate and discrete identity is a political and social construct, in the cases of Sardinian and Asturian doubts over their respective ‘languageness’ have real material consequences, particularly in relation to language policy decisions at the state level. The Asturian example highlights how its lack of official status means that it is either ignored or subjected to repeated challenges to its status as a language variety deserving of recognition and support, reflecting how ‘official language’ in the Spanish context is often understood in practice as synonymous with the theoretically broader category of ‘language’. In contrast, the recent state recognition of Sardinian speakers as a linguistic minority in Italy (Law 482/1999) illustrates how legal recognition served to overcome existing obstacles to the implementation of regional language policy measures. At the same time, the limited subsequent effects of this Law, particularly in the sphere of education, are a reminder of the shortcomings of top-down policies which fail to engage with the local language practices and attitudes of the communities of speakers recognized. The contrastive focus of this article thus acknowledges the continued material consequences of top-down language classification, while highlighting its inadequacies as a language policy mechanism which reinforces artificial distinctions between speech varieties and speakers deserving of recognition
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