949 research outputs found

    Combining polynomial chaos expansions and genetic algorithm for the coupling of electrophysiological models

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    The number of computational models in cardiac research has grown over the last decades. Every year new models with di erent assumptions appear in the literature dealing with di erences in interspecies cardiac properties. Generally, these new models update the physiological knowledge using new equations which reect better the molecular basis of process. New equations require the fi tting of parameters to previously known experimental data or even, in some cases, simulated data. This work studies and proposes a new method of parameter adjustment based on Polynomial Chaos and Genetic Algorithm to nd the best values for the parameters upon changes in the formulation of ionic channels. It minimizes the search space and the computational cost combining it with a Sensitivity Analysis. We use the analysis of di ferent models of L-type calcium channels to see that by reducing the number of parameters, the quality of the Genetic Algorithm dramatically improves. In addition, we test whether the use of the Polynomial Chaos Expansions improves the process of the Genetic Algorithm search. We conclude that it reduces the Genetic Algorithm execution in an order of 103 times in the case studied here, maintaining the quality of the results. We conclude that polynomial chaos expansions can improve and reduce the cost of parameter adjustment in the development of new models.Peer ReviewedPostprint (author's final draft

    Immunotherapy of lung cancer: An update

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    In Germany lung cancer is the leading cause of cancer-associated death in men. Surgery, chemotherapy and radiation may enhance survival of patients suffering from lung cancer but the enhancement is typically transient and mostly absent with advanced disease; eventually more than 90% of lung cancer patients will die of disease. New approaches to the treatment of lung cancer are urgently needed. Immunotherapy may represent one new approach with low toxicity and high specificity but implementation has been a challenge because of the poor antigenic characterization of these tumors and their ability to escape immune responses. Several different immunotherapeutic treatment strategies have been developed. This review examines the current state of development and recent advances with respect to non-specific immune stimulation, cellular immunotherapy ( specific and non-specific), therapeutic cancer vaccines and gene therapy for lung cancer. The focus is primarily placed on immunotherapeutic cancer treatments that are already in clinical trial or well progressed in preclinical studies. Although there seems to be a promising future for immunotherapy in lung cancer, presently there is not standard immunotherapy available for clinical routine

    CYTOCHROME P450 3A13 AND ENDOTHELIN JOINTLY MEDIATE DUCTUS ARTERIOSUS CONSTRICTION TO OXYGEN IN MICE

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    The fetal ductus arteriosus (DA) contracts to oxygen, and this feature, maturing through gestation, is considered important for its closure at birth. We have previously obtained evidence of the involvement of cytochrome P-450, possibly of the 3A subfamily (CYP3A), in oxygen sensing and have also identified endothelin (ET)-1 as the attendant effector for the contraction. Here, we examined comparatively wild-type (WT) and CYP3Anull (Cyp3a(-/-)) mice for direct validation of this concept. We found that the CYP3A subfamily is represented only by CYP3A13 in the WT DA. CYP3A13 was also detected in the DA by immunofluorescence microscopy, being primarily colocalized with the endoplasmic reticulum in both endothelial and muscle cells. However, a distinct signal was also evident in the plasma membrane. Isolated DAs from term WT animals developed a sustained contraction to oxygen with transient contractions superimposed. Conversely, no tonic response occurred in Cyp3a(-/-) DAs, whereas the phasic response persisted unabated. Oxygen did not contract the preterm WT DA but caused a full-fledged contraction after retinoic acid (RA) treatment. RA also promoted an oxygen contraction in the Cyp3a(-/-) DA. However, responses of RA-treated WT and Cyp3a(-/-) mice differed in that only the former abated with ET-1 suppression. This implies the existence of an alternative target for RA responsible for the oxygen-induced contraction in the absence of CYP3A13. In vivo, the DA was constricted in WT and Cyp3a(-/-) newborns, although with a tendency to be less narrowed in the mutant. We conclude that oxygen acts primarily through the complex CYP3A13 (sensor)/ET-1 (effector) and, in an accessory way, directly onto ET-1. However, even in the absence of CYP3A13, the DA may close postnatally thanks to the contribution of ET-1 and the likely involvement of compensating mechanism(s) identifiable with an alternative oxygen-sensing system and/or the withdrawal of relaxing influence(s) operating prenatally

    Neuro-hormonal effects of physical activity in the elderly

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    22/07/14 meb.OA paper, author retains copyright.Thanks to diagnostic and therapeutic advances, the elderly population is continuously increasing in the western countries. Accordingly, the prevalence of most chronic age-related diseases will increase considerably in the next decades, thus it will be necessary to implement effective preventive measures to face this epidemiological challenge. Among those, physical activity exerts a crucial role, since it has been proven to reduce the risk of cardiovascular diseases, diabetes, obesity, cognitive impairment and cancer. The favorable effects of exercise on cardiovascular homeostasis can be at least in part ascribed to the modulation of the neuro-hormonal systems implicated in cardiovascular pathophysiology. In the elderly, exercise has been shown to affect catecholamine secretion and biosynthesis, to positively modulate the renin-angiotensin-aldosterone system and to reduce the levels of plasma brain natriuretic peptides. Moreover, drugs modulating the neuro-hormonal systems may favorably affect physical capacity in the elderly. Thus, efforts should be made to actually make physical activity become part of the therapeutic tools in the elderly. © 2013 Femminella, de Lucia, Iacotucci, Formisano, Petraglia, Allocca, Ratto, DAmico, Rengo, Pagano, Bonaduce, Rengo and Ferrara

    Tipificación en Gutierrezia (Asteraceae, Astereae)

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    During the course of the revision of the South American species of Gutierrezia, we have detected names that require typification. After the analysis of the protologues and the herbarium specimens, we designated eight lectotypes and one neotype for nine names of the Gutierrezia genus and we assigned the category of holotype to one specimen. A detailed discussion is provided for each case.Durante el transcurso de la revisión de las especies sudamericanas de Gutierrezia, hemos podido hallar nombres que requieren tipificación. Luego del análisis de los protologos y especímenes de herbario, hemos designado ocho lectótipos y un neótipo para nueve nombres del género Gutierrezia. Además, se asignó la categoría de hólotipo a un especimen. Se provee una discusión detallada para cada nombre

    World radiocommunication conference 12 : implications for the spectrum eco-system

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    Spectrum allocation is once more a key issue facing the global telecommunications industry. Largely overlooked in current debates, however, is the World Radiocommunication Conference (WRC). Decisions taken by WRC shape the future roadmap of the telecommunications industry, not least because it has the ability to shape the global spectrum allocation framework. In the debates of WRC-12 it is possible to identify three main issues: enhancement of the international spectrum regulatory framework, regulatory measures required to introduce Cognitive Radio Systems (CRS) technologies; and, additional spectrum allocation to mobile service. WRC-12 eventually decided not to change the current international radio regulations with regard to the first two issues and agreed to the third issue. The main implications of WRC-12 on the spectrum ecosystem are that most of actors are not in support of the concept of spectrum flexibility associated with trading and that the concept of spectrum open access is not under consideration. This is explained by the observation that spectrum trading and spectrum commons weaken state control over spectrum and challenge the main principles and norms of the international spectrum management regime. In addition, the mobile allocation issue has shown the lack of conformity with the main rules of the regime: regional spectrum allocation in the International Telecommunication Union (ITU) three regions, and the resistance to the slow decision making procedures. In conclusion, while the rules and decision-making procedures of the international spectrum management regime were challenged in the WRC-12, the main principles and norms are still accepted by the majority of countries

    The politics of collective repair: examining object-relations in a postwork society

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    In this article we look at repair as an emergent focus of recent activism in affluent societies, where a number of groups are reclaiming practices of repair as a form of political and ecological action. Ranging from those that fight for legislative change to those groups who are trying to support ecological and social change through everyday life practices, repair is beginning to surface tensions in everyday life and as such poses opportunities for its transformation. We survey a few of the practices that make up this movement in its various articulations, to take stock of their current political import. While we suggest that these practices can be seen as an emergent lifestyle movement, they should not be seen as presenting a unified statement. Rather, we aim to show that they articulate a spectrum of political positions, particularly in relation to the three specific issues of property, pedagogy and sociality. These three dimensions are all facets of current internal discrepancies of repair practices and moreover express potential bifurcations as this movement evolves. Drawing on a diverse methodology that includes discourse analysis and participant observation, we suggest some of the ways in which this growing area of activity could play a significant role in resisting the commodification of the everyday and inventing postwork alternatives

    Temporary techno-social gatherings? A (hacked) discussion about open practices

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    This paper is rooted in an experimental inquiry of issue-oriented temporary techno-social gatherings or TTGs, which are typically referred to as hackathons, workshops or pop-ups and employ rapid design and development practices to tackle technical challenges while engaging with social issues. Based on a collaboration between three digital practitioners (a producer, a researcher and a designer), qualitative and creative data was gathered across five different kinds of TTG events in London and in Tartu which were held in partnership with large institutions, including Art:Work at Tate Exchange within Tate Modern, the Mozilla Festival at Ravensbourne College and the 2017 Association of Internet Researchers conference hosted in Tartu. By analysing data using an open and discursive approach manifested in both text and visual formats, we reflect on the dynamic and generative characteristics of TTG gatherings while also arriving at our own conclusions as situated researchers and practitioners who are ourselves engaged in increasingly messy webs where new worlds of theory and practice are built

    Artificial insemination in South American camelids and wild equids

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    An overview of the present status of the use of artificial insemination (AI) in South American camelids and wild equids is offered. Technical aspects of semen collection, dilution and cryopreservation have limited the development and use of AI in camelid and equid species. To-date, efficiency is low but progress has been made and viable offspring have been produced through the use of AI in domestic South American camelids using both fresh and frozen semen. The origin, composition, and function of the viscous component of camelid seminal plasma remain a mystery and an obvious area for future research. A better understanding of the normal constituents of seminal plasma will enable the rational design of semen extenders suitable for camelids. Post-thaw sperm viability is very low, and studies are needed to address questions of optimal freezing and thawing procedures as well as the insemination dose. The basis for differences in reported pregnancy rates with sexed and frozen semen in domestic equids, and the ultimate success of AI in wild equids will require continued research into the ‘‘stallion effect’’, extenders and cryoprotectants, optimal volume and number of spermatozoa, temperatures during handling, processing an transport, and insemination techniques. In both camelids and equids, research on domestic species under controlled conditions provides and excellent opportunity to develop effective semen handling techniques for application in wild and endangered species of the respective families

    Guidelines of the Brazilian Association of Studies on Alcohol and Other Drugs (ABEAD) for diagnoses and treatment of psychiatric comorbidity with alcohol and other drugs dependence

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    Recently, several studies have focused on comorbity psychiatric disorders with alcohol and other substance dependence. The Brazilian Association of Studies on Alcohol and Other Drugs proposed the Brazilian Guidelines project. This study review diagnostic and therapeutic criteria to the most prevalent psychiatric comorbidities. Randomized clinical trials, epidemiological, animal studies and other forms of research are reviewed. The main psychiatric comorbidities are studied based on guidelines adopted by other countries and the literature data resumed. Epidemiological aspects, diagnoses, integrated treatment and service organization, as well as specific psychotherapic and pharmacological treatment are discussed. The Brazilian Association of Studies on Alcohol and Other Drugs Guidelines reassures the importance of adequate diagnoses and treatment regarding alcoholic and drug dependent patients suffering of comorbid psychiatric disorders.O diagnóstico e tratamento de comorbidade psiquiátrica e dependência de álcool e outras substâncias tem sido objeto de inúmeros estudos nos últimos anos. A Associação Brasileira de Estudos do Álcool e Outras Drogas desenvolveu o projeto Diretrizes. Este trabalho visa o desenvolvimento de critérios diagnósticos e terapêuticos atualizados para as comorbidades psiquiátricas mais prevalentes. Ensaios clínicos randomizados, estudos epidemiológicos, com animais e outros estudos são revisados. As principais comorbidades psiquiátricas são estudadas e os dados de literatura resumidos, tendo como referência diretrizes adotadas em outros países. São abordados aspectos epidemiológicos, critérios diagnósticos, tratamento integrado e organização de serviço especializado, assim como especificidades do tratamento psicoterápico e farmacológico. As Diretrizes da Associação Brasileira de Estudos do Álcool e Outras Drogas reforçam a importância da abordagem adequada do dependente químico portador de comorbidade psiquiátrica.Universidade Federal de Santa Catarina Núcleo de PsiquiatriaInstituto de Psiquiatria de Santa CatarinaUniversidade Federal de São Paulo (UNIFESP) Unidade de Pesquisa em Álcool e DrogasSanta Casa de Misericórdia de São Paulo Unidade de Álcool e DrogasUniversidade de São Paulo Faculdade de Medicina Hospital das ClinicasCentro de Atendimento Médico e SocialHospital de Clínicas de Porto AlegreHospital Israelita Albert EinsteinSanta Casa do Rio de Janeiro Setor de Dependência QuímicaUniversidade Gama FilhoUNIFESP, Unidade de Pesquisa em Álcool e DrogasSciEL
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