42 research outputs found

    Material reutilization cycles across industries and production lines

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    The concept of Industrial Symbiosis aims at organizing industrial activity like a living ecosystem where the by-product outputs of one process are used as valuable raw material input for another process. A significant method for the systematic planning of Industrial Symbiosis is found in input–output matching, which is aimed at collecting material input and output data from companies, and using the results to establish links across industries. The collection and classification of data is crucial to the development of synergies in Industrial Symbiosis. Public and private institutions involved in the planning and development of Industrial Symbiosis rely however on manual interpretation of information in the course of creating synergies. Yet, the evaluation and analysis of these data sources on Industrial Symbiosis topics is a tall order. Within this chapter a method is presented which describes value creation activities according to the Value Creation Module (VCM). They are assessed before they are integrated in Value Creation Networks (VCNs), where alternative uses for by-products are proposed by means of iterative input-output matching of selected value creation factors

    Export from the endoplasmic reticulum represents the limiting step in the maturation and cell surface expression of the human δ opioid receptor

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    Abstract Synthesis and maturation of G protein-coupled receptors are complex events that require an intricate combination of processes that include protein folding, post-translational modifications, and transport through distinct cellular compartments. Relatively little is known about the nature and kinetics of specific steps involved in these processes. Here, the human δ opioid receptor expressed in human embryonic kidney 293S cells is used as a model to delineate these steps and to establish the kinetics of receptor synthesis, glycosylation, and transport. We found that the receptor is synthesized as a core-glycosylatedM r 45,000 precursor that is converted to the fully mature M r 55,000 receptor with a half-time of about 120 min. In addition to trimming and processing of two N-linked oligosaccharides, maturation involves addition of O-glycans containing N-acetylgalactosamine, galactose, and sialic acid. In contrast to N-glycosylation, which is initiated co-translationally and is completed when the protein reaches the trans-Golgi network, O-glycosylation was found to occur only after the receptor exits from the endoplasmic reticulum (ER) and was terminated as early as thetrans-Golgi cisternae. Once the carbohydrates are fully processed and the receptor reaches the trans-Golgi network, it is transported to the cell surface in about 10 min. The exit from the ER was found to be the limiting step in overall processing of the receptor. This indicates that early events in the folding of the receptor are probably rate-limiting and that receptor folding intermediates are retained in the ER until they can adopt the correct conformation. The overall low efficiency of receptor maturation, less than 50% of the precursor being processed to the fully glycosylated protein, further suggests that only a fraction of the synthesized receptors attain properly folded conformation that allows exit from the ER. This indicates that folding and ER export are key events in control of receptor cell surface expression. Whether or not the low efficiency of the ER export is a general feature among G protein-coupled receptors remains to be investigated

    Ligands act as pharmacological chaperones and increase the efficiency of δ opioid receptor maturation

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    The endoplasmic reticulum (ER) is recognized as an important site for regulating cell surface expression of membrane proteins. We recently reported that only a fraction of newly synthesized δ opioid receptors could leave the ER and reach the cell surface, the rest being degraded by proteasomes. Here, we demonstrate that membrane-permeable opioid ligands facilitate maturation and ER export of the receptor, thus acting as pharmacological chaperones. We propose that these ligands stabilize the newly synthesized receptor in the native or intermediate state of its folding pathway, possibly by inducing stabilizing conformational constrains within the hydrophobic core of the protein. The receptor precursors that are retained in the ER thus represent fully competent folding intermediates that can be targets for pharmacological intervention aimed at regulating receptor expression and cellular responsiveness. The pharmacological chaperone action is independent of the intrinsic signaling efficacy of the ligand, since both agonists and antagonists were found to promote receptor maturation. This novel property of G protein-coupled receptor ligands may have important implications when considering their effects on cellular responsiveness during therapeutic treatments

    Parâmetros e paradigmas em meta-avaliação: uma revisão exploratória e reflexiva Parameters and paradigms for meta-evaluation: an exploratory and reflective review

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    A avaliação da avaliação não é um simples jogo de palavras ou uma indagação sobre quem avalia a avaliação. Muito mais do que isso, trata-se de avaliar os diversos componentes de um processo avaliativo e os próprios avaliadores. No presente artigo, pretendemos abordar algumas possibilidades da meta-avaliação no campo da avaliação de programas e serviços: fomentar a interação entre a produção teórica e prática no campo; auxiliar no balizamento de métodos e estratégias em uma área marcada por interesses políticos e pela profusão de possibilidades metodológicas; e fomento do rigor ético e científico das práticas avaliativas. Concluiremos esta resenha exploratória da literatura discutindo algumas questões históricas e políticas envolvendo a avaliação e a meta-avaliação de programas e serviços, apresentando críticas às pretensões universalistas e igualitárias presentes em alguns posicionamentos.<br>The evaluation of an evaluation is not a mere play on words or simply an investigation into the person who evaluates the evaluation. It is far more than that. It is about how to evaluate the diverse components of the evaluation process and the evaluators per se. In this paper, we discuss some promising possibilities for meta-evaluation in the field of evaluation of programs and services. These include fostering interaction between theoretical and practical production in fieldwork and supporting the definition of methods and strategies in a sector imbued with political interests and a profusion of methodological possibilities, and promoting ethical and scientific rigor in the evaluation practices. We conclude this exploratory and reflective review by raising some historical and political questions related to evaluation and meta-evaluation of programs and services and by criticizing the universalist and egalitarian pretensions contained in some evaluation approaches

    Newly synthesized human δ opioid receptors retained in the endoplasmic reticulum are retrotranslocated to the cytosol, deglycosylated, ubiquitinated, and degraded by the proteasome

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    Abstract We have previously shown that only a fraction of the newly synthesized human δ opioid receptors is able to leave the endoplasmic reticulum (ER) and reach the cell surface (Petäjä-Repo, U. E, Hogue, M., Laperrière, A., Walker, P., and Bouvier, M. (2000) J. Biol. Chem. 275, 13727–13736). In the present study, we investigated the fate of those receptors that are retained intracellularly. Pulse-chase experiments revealed that the disappearance of the receptor precursor form (M r 45,000) and of two smaller species (Mr 42,000 and 39,000) is inhibited by the proteasome blocker, lactacystin. The treatment also promoted accumulation of the mature receptor form (Mr 55,000), indicating that the ER quality control actively routes a significant proportion of rescuable receptors for proteasome degradation. In addition, degradation intermediates that included full-length deglycosylated (Mr 39,000) and ubiquitinated forms of the receptor were found to accumulate in the cytosol upon inhibition of proteasome function. Finally, coimmunoprecipitation experiments with the β-subunit of the Sec61 translocon complex revealed that the receptor precursor and its deglycosylated degradation intermediates interact with the translocon. Taken together, these results support a model in which misfolded or incompletely folded receptors are transported to the cytoplasmic side of the ER membrane via the Sec61 translocon, deglycosylated and conjugated with ubiquitin prior to degradation by the cytoplasmic 26 S proteasomes

    Community health nursing practices in contexts of poverty, uncertainty and unpredictability: a systematization of personal experiences

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    Several years of professional nursing practices, while living in the poorest neighbourhoods in the outlying areas of Brazil's Amazon region, have led the author to develop a better understanding of marginalized populations. Providing care to people with leprosy and sex workers in riverside communities has taken place in conditions of uncertainty, insecurity, unpredictability and institutional violence. The question raised is how we can develop community health nursing practices in this context. A systematization of personal experiences based on popular education is used and analyzed as a way of learning by obtaining scientific knowledge through critical analysis of field practices. Ties of solidarity and belonging developed in informal, mutual-help action groups are promising avenues for research and the development of knowledge in health promotion, prevention and community care and a necessary contribution to national public health programmers
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