21 research outputs found

    The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases

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    Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology

    Lion, Ungulate, and Visitor Reactions to Playbacks of Lion Roars at Zoo Atlanta

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    Felids in captivity are often inactive and elusive in zoos, leading to a frustrating visitor experience. Eight roars were recorded from an adult male lion and played back over speakers as auditory enrichment to benefit the lions while simultaneously enhancing the zoo visitor experience. In addition, ungulates in an adjacent exhibit were observed to ensure that the novel location and increased frequency of roars did not lead to a stress or fear response. The male lion in this study roared more in the playback phase than in the baseline phases while not increasing any behaviors that would indicate compromised welfare. In addition, zoo visitors remained at the lion exhibit longer during playback. The nearby ungulates never exhibited any reactions stronger than orienting to playbacks, identical to their reactions to live roars. Therefore, naturalistic playbacks of lion roars are a potential form of auditory enrichment that leads to more instances of live lion roars and enhances the visitor experience without increasing the stress levels of nearby ungulates or the lion themselves, who might interpret the roar as that of an intruder

    Chemical CO2 recycling via dry and bi reforming of methane using Ni-Sn/Al2O3 and Ni-Sn/CeO2-Al2O3 catalysts

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    Carbon formation and sintering remain the main culprits regarding catalyst deactivation in the dry and bi-reforming of methane reactions (DRM and BRM, respectively). Nickel based catalysts (10 wt.%) supported on alumina (Al2O3) have shown no exception in this study, but can be improved by the addition of tin and ceria. The effect of two different Sn loadings on this base have been examined for the DRM reaction over 20 h, before selecting the most appropriate Sn/Ni ratio and promoting the alumina base with 20 wt.% of CeO2. This catalyst then underwent activity measurements over a range of temperatures and space velocities, before undergoing experimentation in BRM. It not only showed good levels of conversions for DRM, but exhibited stable conversions towards BRM, reaching an equilibrium H2/CO product ratio in the process. In fact, this work reveals how multicomponent Ni catalysts can be effectively utilised to produce flexible syngas streams from CO2/CH4 mixtures as an efficient route for CO2 utilisation

    Teleostomía y telecura. También en el paciente urológico

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    La teleostomía y la telecura son consultas virtuales que permiten al paciente recibir cuidados especializados en el propio domicilio. Con esto vamos a conseguir que los pacientes tengan que desplazarse con menor frecuencia al centro de referencia, mejorando así el confort y tranquilidad que les ofrece su propio hogar. Dicha consulta facilita la tarea diaria de enfermería de Atención Primaria contando con el apoyo de profesionales expertos, que pueden orientar, ayudar y guiar en la realización de los cuidados específicos relacionados con las heridas crónicas y/u ostomías. Esto le permitirá al profesional ser más resolutivo, a la vez que se reducirán los ingresos hospitalarios y consecuentemente el gasto sanitario

    The relative importance of disturbance and environmental stress at local and regional scales in French coastal sand dunes

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    Questions: 1. Is there a primary role of disturbance at local scale and of environmental stress at regional scale? 2. Does disturbance increase or decrease environmental stress at local scale? Location: The Atlantic coastal dune system of the Aquitaine Region (France). Methods: Species biomass and 16 environmental variables were sampled in 128 quadrats along a local beach-inland gradient and a regional North-South gradient. Environmental data were analysed with ANOVAs and vegetation-environment relationships with Canonical Correspondence Analysis. Results: At the local scale community composition was primarily driven by disturbance due to sand burial, whereas water and nutrient stress better explained regional differences. However, random biogeographical events are very likely to also affect community composition at the largest scale. The main interaction between environmental stress and disturbance was the mitigation of nutrient stress induced by disturbance at a local scale. This was due to a positive direct effect of sand burial and a positive indirect effect of wind (decrease in VPD by ocean spray). Although wind had also a significant effect on soil conductivity and pH, there was no evidence that these factors had any role in community composition. Conclusions: Our results support the hypothesis that disturbance had a primary role at local scale and environmental stress at regional scale but further research is needed to separate the effect of stress from that of dispersal at regional scale. We also demonstrated that environmental stress in primary succession may not always decline with decreasing disturbance
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