364 research outputs found

    Estimation of relative water use among ornamental landscape species

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    Abstract Low water use plantings may enhance water conservation in dry landscapes. However, appropriate plant selection is hindered by the dearth of information available on the water needs of different species. A direct method of classification was tested under the hypothesis that relative water use by woody landscape species growing in 3.8 l containers would be representative of the water use of the same species in the landscape. Four species of distinctly different ecological origin (Leucophyllum frutescens, Spiraea vanhouteii, Viburnum tinus, Arctostaphylos densiflora) were chosen in order to obtain a wide range of responses, and their water use was measured in plants growing in 3.8 l containers and compared to that of the same species growing in drainage lysimeters, representative of landscape conditions. Half of the plants were subjected to successive cycles of stress by withholding water after irrigation to container capacity in containers, or applying a fraction of the potential evapotranspiration in lysimeters. The good fit of the regression of average daily water use by lysimeter plants on average daily water use by container plants (R 2 = 0.87, P < 0.01) reflects the consistency of relative water use of the four species. Measurement of water use at the end of nursery production may be useful for predicting the relative water use of various species after establishment in the landscape

    Tribological performance of esters, friction modifier and antiwear additives for electric vehicle applications

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    The replacement of conventional lubricants with esters is an alternative to provide a low environmental impact and at the same time excellent lubricity features, the high solubility of additives, good viscosity index, low volatility, and high thermal stability. Friction modifiers and antiwear/extreme pressure additives are extensively used to save energy and increase operational life in machine components. In this study, the lubricity of a Group IV base oil containing ester and various benchmark friction modifiers and/or antiwear/extreme pressure additives is measured to evaluate the influence of the ester on the tribological performance of the mixture components. The tribological performance is discussed based on the tabulation of the traction coefficient using a Mini-Traction-Machine and on the measurement of the specific wear rate from the wear scar of the experimental studies using an optical profilometer. In general, results show synergies between the ester and the additive formulations, reducing the wear rate to 75% and decreasing the traction coefficient a 20 to 50%, depending on the evaluated additive.This work received the support of the Pla de Doctorats Industrials from Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement of the Generalitat de Catalunya.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaPostprint (published version

    Evaluation of the efficiency of a conventional PCR protocol for the diagnosis of bacterial spot disease caused by Xanthomonas arboricola pv. pruni in stone fruits and almond

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    Xanthomonas arboricola pv. pruni (Xap), the causal agent of bacterial spot disease of stone fruits and almond, has a quarantine status for the European Union and the European and Mediterranean Plant Protection Organization. The symptoms in the diverse hosts show some differences and, although being quite typical, could be confused with those of some fungal diseases or other biotic or abiotic causes. Consequently, an accurate molecular diagnosis method is required for a rapid identification of the pathogen in samples of imported plants, from nurseries, orchards, etc. A protocol for conventional PCR designed by Pagani (2004) has been the only molecular analytic tool available for several years. It has been optimised for improving its specificity and sensitivity, and the results of its evaluation in 316 bacterial spot-like symptomatic samples of almond, apricot, cherry, Japanese plum and peach, compared with those of isolation and real-time PCR, are reported. The optimised PCR protocol showed specificity for a collection of Xap strains tested. Few non-desired reactions were obtained with some other xanthomonads which have not been reported from Prunus species. Sensitivity thresholds ranged from 102 to 105 CFU ml-1, depending on the hosts and type of plant material. This conventional PCR assay proved to be an excellent candidate for a rapid screening and presumptive diagnosis in cases where real-time PCR equipment is not available

    Empresas del IBEX-35: Consejeras y directivas de alta dirección

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    La presencia de mujeres en la empresa es cada vez más común y necesaria para lograr una mayor equidad de género en el ámbito laboral. A lo largo de la historia, las mujeres se han enfrentado a barreras y discriminación en el mundo laboral, pero hoy en día, la situación está cambiando gracias a las luchas feministas, a una mayor conciencia social sobre la importancia de la igualdad de oportunidades y al apoyo legislativo. Las mujeres aportan una visión y perspectiva diferente en la organización, lo que puede repercutir en una mayor creatividad, innovación y, por ende, rentabilidad. Sin embargo, todavía existen obstáculos y desafíos que enfrentan las mujeres en el ámbito laboral, como la brecha salarial de género, la falta de representación en cargos directivos y de liderazgo, y la discriminación basada en estereotipos de género. Además, su presencia en cargos directivos y de liderazgo puede fomentar la diversidad y la inclusión en la empresa, por ello es importante conocer la incidencia de la mujer en las empresas que cotizan en el Índice bursátil IBEX-35. Para ello, se utiliza el análisis de datos secundarios de la Comisión Nacional del Mercado de Valores (CNMV) y se aplica el algoritmo de Pichat a partir de la distancia de Hamming para conocer esas actuaciones. De esta forma, se pretende determinar si se cumple con las recomendaciones de la normativa actual en este campo. Es importante seguir trabajando en la eliminación de estas barreras para lograr una mayor igualdad de oportunidades en el mundo laboral y promover el desarrollo profesional y personal de todas las personas, independientemente de su género

    Lateral Hypothalamus GABAergic Neurons Modulate Consummatory Behaviors Regardless of the Caloric Content or Biological Relevance of the Consumed Stimuli

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    It was recently reported that activation of a subset of lateral hypothalamus (LH) GABAergic neurons induced both appetitive (food-seeking) and consummatory (eating) behaviors in vGat-ires-cre mice, while inhibition or deletion of GABAergic neurons blunted these behaviors. As food and caloric-dense liquid solutions were used, the data reported suggest that these LH GABAergic neurons may modulate behaviors that function to maintain homeostatic caloric balance. Here we report that chemogenetic activation of this GABAergic population in vGat-ires-cre mice increased consummatory behavior directed at any available stimulus, including those entailing calories (food, sucrose, and ethanol), those that do not (saccharin and water), and those lacking biological relevance (wood). Chemogenetic inhibition of these neurons attenuated consummatory behaviors. These data indicate that LH GABAergic neurons modulate consummatory behaviors regardless of the caloric content or biological relevance of the consumed stimuli

    Host plant scent mediates patterns of attraction/repellence among predatory mites

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    [EN] In mite communities, behavioral and foraging decisions of individuals rely on semiochemicals that they gather from the environment, which contain odors from plants, herbivores, and predators. Because herbivorous mites commonly co-occur with several species of phytoseiid predatory mites, which may engage in intraguild predation (IGP), predator mite decision-making relies on their ability to recognize odors signaling the presence of the herbivore but also that of potential competitors/predators. Here the odor-related foraging decisions of three predatory mites, Euseius stipulatus (Athias-Henriot), Neoseiulus californicus (McGregor) and Phytoseiulus persimilis (Athias-Henriot) (Mesostigmata: Phytoseiidae), which co-occur in citrus, compete for the herbivore Tetranychus urticae Koch (Prostigmata: Tetranychidae), and can engage in IGP were investigated. The composition of the volatile blends associated with the three predators was characterized. Moreover, the effect of these odors on the predators foraging decisions was measured. Results revealed that (1) the volatile signature of the three predatory mites is species specific, (2) the predators¿ foraging behavior is affected by heterospecific predator odors, and (3) predator responses strongly depend on the host plant: mutual attraction and mutual repellence occurred in Cleopatra mandarin and sour orange, respectively. These findings have important consequences for the management of systems where these species occur. The odor blends that make predators that share pest species as prey avoid each other could be used to improve pest control by minimizing undesired negative interactions among predator species, and by locally increasing predation risk on herbivore pest species.The authors thank M. Piquer (UJI) for technical assistance and J. Calvo (Koppert Biological Systems) for the supply of N. californicus and P. persimilis. This study was partially funded by the Spanish Research State Agency (research grants AGL2014-55616-C3, AGL2015-64990-2R, PID2019-103863RB-I00 and BES-2015-074570).Cruz-Miralles, J.; Cabedo-Lopez, M.; Guzzo, M.; Vacas, S.; Navarro-Llopis, V.; Ibáñez-Gual, MV.; Flors, V.... (2022). Host plant scent mediates patterns of attraction/repellence among predatory mites. Entomologia Generalis. 42(2):217-229. https://doi.org/10.1127/entomologia/2021/1237S21722942

    Ammonia binding to the oxygen-evolving complex of photosystem II identifies the solvent-exchangeable oxygen bridge (μ-oxo) of the manganese tetramer

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    The assignment of the two substrate water sites of the tetra-manganese penta-oxygen calcium (Mn4O5Ca) cluster of photosystem II is essential for the elucidation of the mechanism of biological O-O bond formation and the subsequent design of bio-inspired water-splitting catalysts. We recently demonstrated using pulsed EPR spectroscopy that one of the five oxygen bridges (μ-oxo) exchanges unusually rapidly with bulk water and is thus a likely candidate for one of the substrates. Ammonia, a water analog, was previously shown to bind to the Mn4O5Ca cluster, potentially displacing a water/substrate ligand [Britt RD, et al. (1989) J Am Chem Soc 111(10):3522–3532]. Here we show by a combination of EPR and time-resolved membrane inlet mass spectrometry that the binding of ammonia perturbs the exchangeable μ-oxo bridge without drastically altering the binding/exchange kinetics of the two substrates. In combination with broken-symmetry density functional theory, our results show that (i) the exchangable μ-oxo bridge is O5 {using the labeling of the current crystal structure [Umena Y, et al. (2011) Nature 473(7345):55–60]}; (ii) ammonia displaces a water ligand to the outer manganese (MnA4-W1); and (iii) as W1 is trans to O5, ammonia binding elongates the MnA4-O5 bond, leading to the perturbation of the μ-oxo bridge resonance and to a small change in the water exchange rates. These experimental results support O-O bond formation between O5 and possibly an oxyl radical as proposed by Siegbahn and exclude W1 as the second substrate water

    El paper dels sistemes de gestió en el desenvolupament de competències transversals en els estudiants

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    S’ha treballat la formació competencial dels estudiants mitjançant la realització d’activitats relacionades amb la implementació de sistemes de gestió (qualitat, medi ambient i seguretat). A l’assignatura “Qualitat i Prevenció” (Grau Química), els alumnes han fet auditories de medi ambient i seguretat als laboratoris de pràctiques de la Facultat de Química. Els alumnes de l’assignatura “Direcció d’operacions en el sector químic” (màster Enginyeria Química) han treballat la implementació del sistemes de gestió mitjançant un joc de rol. Finalment, a “Anàlisi i estimació del risc” (màster Enginyeria Química) s’ha treballat una part concreta del sistema de gestió de la seguretat mitjançant l’anàlisi de risc d’una pràctica de laboratori. Els estudiants han treballat competències relacionades amb l’ètica, capacitat d’expressió oral i escrita, capacitat de diàleg, capacitat de lideratge, gestió de la qualitat, el medi ambient i la seguretat. Els resultats de les actuacions han posat de manifest mancances i problemes als laboratoris i als sistemes de gestió, l’anàlisi del quals ha de permetre millorar la qualitat de les pràctiques i dels ensenyaments. Finalment, les enquestes fetes a alguns dels grups implicats han reflectit un alt grau de satisfacció amb la feina feta i la manera de fer-la

    Assessment of Voluntary Ethanol Consumption and the Effects of a Melanocortin (MC) Receptor Agonist on Ethanol Intake in Mutant C57BL/6J Mice Lacking the MC-4 Receptor: ETHANOL AND MC-4 RECEPTOR

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    The melanocortin (MC) system is composed of peptides that are cleaved from the polypeptide precursor proopiomelanocortin (POMC). Recent evidence shows that chronic exposure to ethanol significantly blunts central MC peptide immunoreactivity and MC receptor (MCR) agonists protect against high ethanol intake characteristic of C57BL/6J mice. Here we assessed the role of the MC-4 receptor (MC4R) in voluntary ethanol intake and in modulating the effects of the non-selective MCR agonist melanotan-II (MTII) on ethanol consumption
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