643 research outputs found

    Improvement of biomethane potential of sewage sludge anaerobic co-digestion by addition of “sherry-wine” distillery wastewater

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    Co-digestion of sewage sludge (SS) with other unusually treated residues has been reported as an efficient method to improve biomethane production. In this work, Sherry-wine distillery wastewater (SWDW) has been proposed as co-substrate in order to increase biomethane production and as a breakthrough solution in the management of both types of waste. In order to achieve this goal, different SS:SW-DW mixtures were employed as substrates in Biomethane Potential (BMP) tests. The biodegradability and biomethane potential of each mixture was determined selecting the optimal co-substrate ratio. Results showed that the addition of SW-DW as a co-substrate improves the anaerobic digestion of SS in a proportionally way in terms of CODs and biomethane production The optimal co-substrates ratio was 50:50 of SS:SW-DW obtaining %VSremoval ¼ 54.5%; YCH4 ¼ 225.1 L CH4/kgsv or 154 L CH4/kgCODt and microbial population of 5.5 times higher than sole SS. In this case, %VSremoval ¼ 48.1%; YCH4 ¼ 183 L CH4/ kgsv or 135 L CH4/kgCODt. The modified Gompertz equation was used for the kinetic modelling of biogas production with successful fitting results (r2 ¼ 0.99). In this sense, at optimal conditions, the maximum productivity reached at an infinite digestion time was (YMAX CH4 ) ¼ 229 ± 5.0 NL/kgSV; the specific constant was K ¼ 25.0 ± 2.3 NL/kgSV$d and the lag phase time constant was (l) ¼ 2.49 ± 0.1

    Nuevas perspectivas de la gobernanza Privada: un análisis desde las prácticas de Responsabilidad social y ambiental de las Empresas en Colombia

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    The investments on social and environmental responsibility in Colombia have generated a new perspective for private governance in terms of sustainability. To understand this phenomenon, we analyze sustainability reports, financial statements and management reports provided by a successful case of sustainability in Colombia. This would be with the purpose of assessing whether or not such policies constitute a potential political instrument to advance in government regulations; otherwise policies would curtail to management strategy with repercussions on corporate image and financial performance for reporting companies. The testing of our research hypotheses concluded that the execution of sustainability reports in Colombia is a recent practice, despite the existence of a normative framework established since the 1991 Constitution. The foregoing may acknowledge that actual importance is due to investments on social innovation and a new approach of private governance, as a response for economic dynamics and political advances in Colombia

    PEPPER, a novel K-homology domain gene, regulates vegetative and gynoecium development in Arabidopsis

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    AbstractPistil final morphology relies on floral meristem homeostasis, proper organ specification and regional differentiation. These are developmental processes in which sophisticated signaling networks are being uncovered. However, further elements for fine-tuning adjustment still remain to be disclosed. At the molecular level, posttranscriptional modulators may fit such a profile. In this work, we describe the characterization of PEPPER (PEP), a novel Arabidopsis gene encoding a polypeptide with K-homology (KH) RNA-binding modules, which acts on vegetative growth and pistil development. PEP was initially identified as one of the gene functions affected in a complex mutant carrying a chromosomal reorganization, which exhibits aberrant phyllotaxy and small fruits with supernumerary carpels. In contrast, plants carrying single-gene pep null mutations exhibit subtle morphological alterations. Individuals bearing a stronger-than-null allele present a phenotype comprising leaf alterations, phyllotactic errors and sporadic presence of fruits with multiple valves. Accordingly, dynamic PEP expression was detected in all major organs examined. Complementation experiments with a PEP genomic clone confirmed a role for PEP as a regulator in vegetative and reproductive development. Moreover, our genetic studies suggest that PEP interacts with element(s) of the CLAVATA signaling pathway

    Análisis bibliométrico y sistémico de la relación entre la gestión y el carbono

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    [EN] This paper aims to present a bibliometric and systemic analysis of the Bibliographic Portfolio (BP) jointly examining the literature related to topics like “Greenhouse gas,” mainly carbon, and “Management,” as published in databases data such as Web of Science and Scopus in the field of economic and social sciences. The Knowledge and Constructivist Development Process methodology —Proknow-C— was used to establish the final portfolio and through the VosViewer program were mapped the various groups or relationships between the studied literature. The paper presents the theoretical and methodological aspects focusing on the areas and countries of study and highlighting the most relevant authors to have researched this particular topic. We use this constructivist model to describe the measurement variables and synthesize the concepts most used in these studies in order to propose new focal points and thematic approaches that could be developed further in the future.[ES] Este trabajo tiene como objetivo presentar un análisis bibliométrico y sistémico del Portafolio Bibliográfico (PB) examinando conjuntamente la literatura relacionada con temas como “Gas de efecto invernadero”, principalmente el carbono, y “Gestión”, según lo publicado en bases de datos como Web of Science y Scopus, en el campo de las ciencias económicas y sociales. Se empleó la metodología del Proceso de Desarrollo del Conocimiento y Constructivismo—Proknow-C— para establecer el portafolio final y a través del programa VosViewer se mapearon los diversos grupos o relaciones entre la literatura estudiada. El trabajo presenta los aspectos teóricos y metodológicos centrándose en las áreas, países de estudio y el reconocimiento de los autores más relevantes que han investigado este tema en particular. A partir de este modelo constructivista, se describen las variables de medición y se sintetizan los conceptos más utilizados en estos estudios, con el fin de proponer nuevos enfoques temáticos que puedan desarrollarse en el futuro.This document was produced thanks to the fact that Yenny Naranjo Tuesta was a beneficiary of the “Colombia Científica - Pasaporte a la Ciencia Program of ICETEX” in the foco – país of Society, which financed her doctoral studies. The authors would like to thank the anonymous reviewers for their comments, which have considerably improved this documen

    Activation in the family of Candida rugosa isolipases by polyethylene glycol

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    Disponible en: http://www.xtal.iqfr.csic.es/publications/jmolcat2005.pdfWe have investigated activation of two isoenzymes (lip1 and lip3) from Candida rugosa in polyethylene glycol (PEG) media. Aqueous solutions of PEG 8000 and 20,000 activate lip3 but not lip1 from C. rugosa. Maximum activation (260%) of lip3 requires 6 h of pre-incubation with PEG 8000 (4%, w/v). PEG seems to shift the equilibrium between the open and the closed forms of lip3 towards the active conformation. Inhibition experiments demonstrate that ligands have easier access to the lip3 active site than to the lip1 active site, both in the presence and the absence of PEG. The presence of PEG in the crystallization medium is responsible for reported differences in the crystal structures of lip1 and lip3. A comparative analysis of crystallographic models of lip1 and lip3 suggests a role for PEG in activation of lip3 and further stabilization of the activated/open form via dimerization in aqueous media.This work has been financed by the Spanish CICYT (PB92/0495 and BIO 96/0837). A predoctoral fellowship for M.F.P. was provided by the Autonomous Community of Madrid (Spain).Peer reviewe

    Photoswitching-Enabled Contrast Enhancement in Light Sheet Fluorescence Microscopy

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    Light sheet fluorescence microscopy enables high-resolution imaging of thick biological samples. By restricting the fluorescence excitation to a single plane, rapid wide-field image acquisition is possible with minimal sample exposure. Although light sheet microscopy is able to resolve subcellular features at depth in model organisms, elevated levels of endogenous autofluorescence often preclude acceptable contrast and may obscure features of interest in general samples. Here we demonstrate how photoswitchable fluorophores can be exploited to boost contrast in light sheet microscopy. The novel detection method enables high specificity while maintaining the optical sectioning capability of the light sheet microscope. Our experiments reveal structures hidden well below the ambient fluorescent background level by enhancing the contrast by 2 orders of magnitude

    A Focus on Ethical Value under the Vision of Leadership, Teamwork, Effective Communication and Productivity

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    The new economy and the knowledge-based society brought significant changes in all the areas of our daily lives. Also, the COVID-19 pandemic and the COVID-19 crisis implicated tremendous transformations in all the domains, on the one hand, threatening the balance of our society and, on the other hand, challenging the dynamic of the new economy development and the rhythm of the societal modernization. In these delicate times, the all-important relationship between ethics, leadership, teamwork, effective communication, productivity, and performance is brought to the attention, in particular, due to its benefits for our society, taking into consideration the pivotal advancement that a well governed relationship of this type could provide to the knowledge-based economy. The present research describes the implication of ethics in leadership, teamwork, effective communication, and productivity, which includes the application of ethical values as university graduates assume the role of each of the mentioned dimensions of study in the organizations. The absence of research that relates ethics to these four elements simultaneously was noticed. This information is essential to know how these dimensions influence the organizational level. The sample that included 410 university graduates was applied in Baja California, Mexico, and the industrial nucleus of great relevance, bordering California in the United States of America. The data was obtained using a questionnaire. A reliability and validity analysis of the measurement instrument was carried out in terms of the ethical values associated with the dimensions mentioned using the exploratory factor analysis by the principal components method. Qualitative items were also analyzed using the constant comparison method. The results obtained in this research provide a greater perspective and practical knowledge and support of usefulness and practical reality to businesspeople and employees, leaders and university graduates; and also extensive to students, teachers, and human beings in general, in order to be better prepared to give and apply solutions with their consequent ethical and productive achievements desired by all. Additionally, this current research has the purpose to raise the will to understand, at a higher level and at a more in-depth degree of knowledge, the relationship between ethics, leadership, teamwork, effective communication, productivity, and performance, in the attempt to foster a creative and innovative business environment, based on a robust and sustainable business administration and business competencies, capable to position at higher ranks the strengths, opportunities, aspirations and outcomes that today's new economy is due to offer and diminish the dangerous effects of the COVID-19 pandemic and the COVID-19 crisis in all the domains

    Contratación internacional de médicos/as latinoamericanos/as en Portugal y España

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    A partir de las experiencias de las/os médicas/os latinoamericanas/os que ejercen su profesión en Portugal y España, el artículo busca comparar el reclutamiento internacional de las/os médicas/os, el reconocimiento de las cualificaciones para el ejercicio de la Medicina, y los procesos de integración profesional en el sistema de salud portugués y español. Para tal fin, se utilizaron métodos cualitativos basados en entrevistas en profundidad. Los resultados muestran semejanzas y divergencias en cada una de las tres dimensiones en los dos contextos

    Modelling of the anaerobic semi-continuous co-digestion of sewage sludge and 2 wine distillery wastewater

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    The semi-continuous mesophilic anaerobic co-digestion of sewage sludge and wine distillery wastewater was investigated. In this sense, the effects of reducing hydraulic retention time (HRT, from 20 d to 8 d) on the degradation of organic matter and methane production were determined. The experimental results showed that anaerobic co-digestion enhanced the biodegradability of the mixture in terms of VS and CODt (7-8% higher) for HRT = 8 d. The methane productivity at HRT = 8 d (18.0 LCH4/kgVS·d), was also enhanced (30% higher) than those obtained in the control experiment. In addition, a mathematical kinetic model was proposed to determine the rate-limiting step of the process. Stoichiometric parameters obtained for SS:WDW (0.115 kgCH4/kgCOD) was higher than SS (0.094 kgCH4/kgCOD), which means that co-digestion increased the rate of consumption because more amount of biodegradable compounds. Kinetic study showed that anaerobic co-digestion favoured methane production rate enhancing the acetate consumption step and making methanogenesis the rate-limiting step in this process
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