949 resultados para Logic of action


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A critical phase in goal striving occurs when setbacks accumulate and goal disengagement becomes an issue. This critical phase is conceptualized as an action crisis and assumed to be characterized by an intrapsychic conflict in which the individual becomes torn between further goal pursuit and goal disengagement. Our theorizing converges with Klinger’s conceptualization of goal disengagement as a process, rather than a discrete event. Two longitudinal field studies tested and found support for the hypothesis that an action crisis not only compromises an individual’s psychological and physiological well-being, but also dampens the cognitive evaluation of the respective goal. In Study 3, marathon runners experiencing an action crisis in their goal of running marathons showed a stronger cortisol secretion and a lower performance in the race 2 weeks later. Results are interpreted in terms of action-phase–specific mindsets with a focus on self-regulatory processes in goal disengagement.

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Population coding is widely regarded as a key mechanism for achieving reliable behavioral decisions. We previously introduced reinforcement learning for population-based decision making by spiking neurons. Here we generalize population reinforcement learning to spike-based plasticity rules that take account of the postsynaptic neural code. We consider spike/no-spike, spike count and spike latency codes. The multi-valued and continuous-valued features in the postsynaptic code allow for a generalization of binary decision making to multi-valued decision making and continuous-valued action selection. We show that code-specific learning rules speed up learning both for the discrete classification and the continuous regression tasks. The suggested learning rules also speed up with increasing population size as opposed to standard reinforcement learning rules. Continuous action selection is further shown to explain realistic learning speeds in the Morris water maze. Finally, we introduce the concept of action perturbation as opposed to the classical weight- or node-perturbation as an exploration mechanism underlying reinforcement learning. Exploration in the action space greatly increases the speed of learning as compared to exploration in the neuron or weight space.

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9-$\beta$-D-arabinofuranosyl-2-fluoroadenine (F-ara-A) is an analogue of adenosine and 2$\sp\prime$-deoxyadenosine with potent antitumor activity both in vitro and in vivo. The mechanism of action of F-ara-A was evaluated both in whole cells and in experimental systems with purified enzymes. F-ara-A was converted to its 5$\sp\prime$-triphosphate F-ara-ATP in cells and then incorporated into DNA in a self-limiting manner. About 98% of the incorporated F-ara-AMP residues were located at the 3$\sp\prime$-termini of DNA strands, suggesting a chain termination property of this compound. DNA synthesis in CEM cells was inhibited by F-ara-A treatment with an IC$\sb{50}$ value of 1 $\mu$M. Cells were not able to restore the normal level of DNA synthesis even after being cultured in drug-free medium for 40 h. A DNA primer extension assay with M13mp18(+) single-stranded DNA template using purified human DNA polymerases $\alpha$ and further revealed that F-ara-ATP competed with dATP for incorporation into the A sites of the elongating DNA strands. The incorporation of F-ara-AMP into DNA resulted in a termination of DNA synthesis at the incorporated A sites. Pol $\alpha$ and $\delta$ were not able to efficiently extend the DNA primer with F-ara-AMP at its 3$\sp\prime$-end. Furthermore, the presence of F-ara-AMP at the 3$\sp\prime$-end of an oligodeoxyribonucleotide impaired its ligation with an adjacent DNA fragment by human and T4 ligases. Human DNA polymerase $\alpha$ incorporated more F-ara-AMP into DNA than polymerase $\delta$ and was more sensitive to the inhibition by F-ara-ATP, suggesting that polymerase $\alpha$ may be a preferred target for this analogue. On the other hand, DNA-dependent nucleotide turnover experiments and sequencing gel analysis demonstrated that DNA polymerase $\delta$ was able to remove the incorporated F-ara-AMP residue from the 3$\sp\prime$-end of the DNA strand with its 3$\sp\prime$-5$\sp\prime$ exonuclease activity in vitro, subsequently permitting further elongation of the DNA strand.^ The incorporation of F-ara-AMP into DNA was linearly correlated both with the inhibition of DNA synthesis and with the loss of clonogenicity. Termination of DNA synthesis and deletion of genetic material resulted from F-ara-AMP incorporation may be the mechanism responsible for cytotoxicity of F-ara-A. (Abstract shortened with permission of author.) ^

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Is the online trade with second-hand products changing individual consumer behaviour? What is the sustainability potential of this activity? How can daily energy-consuming routines at the workplace be changed? Do major changes in the course of people's lives represent opportunities to modify their consumer behaviour towards greater sustainability? These are only some of the research questions studied in the focal topic "From Knowledge to Action - New Paths towards Sustainable Consumption" which is funded by the German Federal Ministry of Education and Research (BMBF) as part of the "Social-ecological Research Programme" (SÖF). This book gives an insight into the research results of the ten project groups. Their diversity highlights that there is much more to "sustainable consumption" than the simple purchase of organic or fair trade products.In addition, overarching conceptual and normative issues were treated across the project groups of the focal topic. Developed collaboratively and moderated by the accompanying research project, the results of the synthesis process are also presented here, as for example how the sustainability of individual consumer behaviour can be evaluated,or which theories of action are particularly useful for specific consumer behaviour phenomena.

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Background: Health behavior change models identify effective self-regulatory skills for behavioral change, but the social context is usually neglected. This study investigated the effectiveness of a dyadic conceptualization of action control for promoting physical activity. Methods: 121 overweight individuals and their partners were randomly allocated to one of two experimental (dyadic vs. individual action control) and two control conditions. Participants completed questionnaires at baseline (T1) and four weeks later (T2) including measures of action control and 7-day recall physical activity. Findings: Results showed that action control signi+cantly increased from T1 to T2 and was overall higher in the experimental conditions compared to control conditions. In terms of physical activity, no overall intervention effect emerged. However, post hoc analyses revealed higher mean levels of sport activities in the dyadic intervention group compared to all other groups. Discussion: Overall, +ndings provide +rst support for the usefulness of a dyadic action control intervention, and suggest further investigation of objective measures of physical activity and secondary outcomes

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BACKGROUND: Enhancing physical activity in overweight and obese individuals is an important means to promote health in this target population. The Health Action Process Approach (HAPA), which was the theoretical framework of this study, focuses on individual self-regulation variables for successful health behavior change. One key self-regulation variable of this model is action control with its three subfacets awareness of intentions, self-monitoring and regulatory effort. The social context of individuals, however, is usually neglected in common health behavior change theories. In order to integrate social influences into the HAPA, this randomized controlled trial investigated the effectiveness of a dyadic conceptualization of action control for promoting physical activity. METHODS/DESIGN: This protocol describes the design of a single-blind randomized controlled trial, which comprises four experimental groups: a dyadic action control group, an individual action control group and two control groups. Participants of this study are overweight or obese, heterosexual adult couples who intend to increase their physical activity. Blocking as means of a gender-balanced randomization is used to allocate couples to conditions and partners to either being the target person of the intervention or to the partner condition. The ecological momentary intervention takes place in the first 14 days after baseline assessment and is followed by another 14 days diary phase without intervention. Follow-ups are one month and six months later. Subsequent to the six-months follow-up another 14 days diary phase takes place.The main outcome measures are self-reported and accelerometer-assessed physical activity. Secondary outcome measures are Body Mass Index (BMI), aerobic fitness and habitual physical activity. DISCUSSION: This is the first study examining a dyadic action control intervention in comparison to an individual action control condition and two control groups applying a single-blind randomized control trial. Challenges with running couples studies as well as advantages and disadvantages of certain design-related decisions are discussed. This RCT was funded by the Swiss National Science Foundation (PP00P1_133632/1) and was registered on 27/04/2012 at http://www.isrctn.com/ISRCTN15705531.

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The cellular targets for estramustine, an antitumor drug used in the treatment of hormone-refractory prostate cancer, are believed to be the spindle microtubules responsible for chromosome separation at mitosis. Estramustine only weakly inhibits polymerization of purified tubulin into microtubules by binding to tubulin (Kd, ≈30 μM) at a site distinct from the colchicine or the vinblastine binding sites. However, by video microscopy, we find that estramustine strongly stabilizes growing and shortening dynamics at plus ends of bovine brain microtubules devoid of microtubule-associated proteins at concentrations substantially below those required to inhibit polymerization of the microtubules. Estramustine strongly reduced the rate and extent both of shortening and growing, increased the percentage of time the microtubules spent in an attenuated state, neither growing nor shortening detectably, and reduced the overall dynamicity of the microtubules. Significantly, the combined suppressive effects of vinblastine and estramustine on the rate and extent of shortening and dynamicity were additive. Thus, like the antimitotic mechanisms of action of the antitumor drugs vinblastine and taxol, the antimitotic mechanism of action of estramustine may be due to kinetic stabilization of spindle microtubule dynamics. The results may explain the mechanistic basis for the benefit derived from combined use of estramustine with vinblastine or taxol, two other drugs that target microtubules, in the treatment of hormone-refractory prostate cancer.

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Much has been learned about vertebrate development by random mutagenesis followed by phenotypic screening and by targeted gene disruption followed by phenotypic analysis in model organisms. Because the timing of many developmental events is critical, it would be useful to have temporal control over modulation of gene function, a luxury frequently not possible with genetic mutants. Here, we demonstrate that small molecules capable of conditional gene product modulation can be identified through developmental screens in zebrafish. We have identified several small molecules that specifically modulate various aspects of vertebrate ontogeny, including development of the central nervous system, the cardiovascular system, the neural crest, and the ear. Several of the small molecules identified allowed us to dissect the logic of melanocyte and otolith development and to identify critical periods for these events. Small molecules identified in this way offer potential to dissect further these and other developmental processes and to identify novel genes involved in vertebrate development.

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Evernimicin (Evn), an oligosaccharide antibiotic, interacts with the large ribosomal subunit and inhibits bacterial protein synthesis. RNA probing demonstrated that the drug protects a specific set of nucleotides in the loops of hairpins 89 and 91 of 23S rRNA in bacterial and archaeal ribosomes. Spontaneous Evn-resistant mutants of Halobacterium halobium contained mutations in hairpins 89 and 91 of 23S rRNA. In the ribosome tertiary structure, rRNA residues involved in interaction with the drug form a tight cluster that delineates the drug-binding site. Resistance mutations in the bacterial ribosomal protein L16, which is shown to be homologous to archaeal protein L10e, cluster to the same region as the rRNA mutations. The Evn-binding site overlaps with the binding site of initiation factor 2. Evn inhibits activity of initiation factor 2 in vitro, suggesting that the drug interferes with formation of the 70S initiation complex. The site of Evn binding and its mode of action are distinct from other ribosome-targeted antibiotics. This antibiotic target site can potentially be used for the development of new antibacterial drugs.

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Fructose-1,6-bisphosphatase (Fru-1,6-Pase; D-fructose-1,6-bisphosphate 1-phosphohydrolase, EC 3.1.3.11) requires two divalent metal ions to hydrolyze alpha-D-fructose 1,6-bisphosphate. Although not required for catalysis, monovalent cations modify the enzyme activity; K+ and Tl+ ions are activators, whereas Li+ ions are inhibitors. Their mechanisms of action are still unknown. We report here crystallographic structures of pig kidney Fru-1,6-Pase complexed with K+, Tl+, or both Tl+ and Li+. In the T form Fru-1,6-Pase complexed with the substrate analogue 2,5-anhydro-D-glucitol 1,6-bisphosphate (AhG-1,6-P2) and Tl+ or K+ ions, three Tl+ or K+ binding sites are found. Site 1 is defined by Glu-97, Asp-118, Asp-121, Glu-280, and a 1-phosphate oxygen of AhG-1,6-P2; site 2 is defined by Glu-97, Glu-98, Asp-118, and Leu-120. Finally, site 3 is defined by Arg-276, Glu-280, and the 1-phosphate group of AhG-1,6-P2. The Tl+ or K+ ions at sites 1 and 2 are very close to the positions previously identified for the divalent metal ions. Site 3 is specific to K+ or Tl+. In the divalent metal ion complexes, site 3 is occupied by the guanidinium group of Arg-276. These observations suggest that Tl+ or K+ ions can substitute for Arg-276 in the active site and polarize the 1-phosphate group, thus facilitating nucleophilic attack on the phosphorus center. In the T form complexed with both Tl+ and Li+ ions, Li+ replaces Tl+ at metal site 1. Inhibition by lithium very likely occurs as it binds to this site, thus retarding turnover or phosphate release. The present study provides a structural basis for a similar mechanism of inhibition for inositol monophosphatase, one of the potential targets of lithium ions in the treatment of manic depression.

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In the 29 years following \"Our Common Future\" by the United Nations, there is considerable debate among governments, civil society, interest groups and business organisations about what constitutes sustainable development, which constitutes evidence for a contested discourse concerning sustainability. The purpose of this study is to understand this debate in the developing economic context of Brazil, and in particular, to understand and critique the social and environmental accounting [SEA] discursive constructions relating to the State-owned, Petrobras as well as to understand the Brazilian literature on SEA. The discourse theory [DT]-based analysis employs rhetorical redescription to analyse twenty-two reports from Petrobras from 2004-2013. I investigate the political notions by employing the methodological framework of the Logics of Critical Explanation [LCE]. LCE engenders five methodological steps: problematisation, retroduction, logics (social, political and fantasmatic), articulation and critique. The empirical discussion suggests that the hegemony of economic development operates to obfuscate, rhetorically, the development of sustainability, so as to maintain the core business of Petrobras conceived as capital accumulation. Equally, these articulations also illustrate how the constructions of SEA operate to serve the company\'s purpose with few (none) profound changes in integration of sustainability. The Brazilian literature on SEA sustains the status quo of neo-liberal market policies that operate to protect the dominant business case approach to maintain an agenda of wealth-creation in relation to social and environmental needs. The articulations of the case manifested in policies regarding, for example, corruption, which involved over-payments for contracts and unsustainable practices relating to the use of fossil fuels and demonstrated that there was antagonism between action and disclosure. The corruption scandal that emerged after SEA disclosures highlighted the rhetorical nature of disclosure when financial resources were subtracted from the company for political parties and engineering contractors hid facts through incomplete disclosures. The articulations of SEA misrepresent a broader context of the meanings associated with sustainability, which restricted the constructions of SEA to principally serve and represent the intention of the most powerful groups. The significance of SEA, then is narrowed to represent particular interests. The study argues for more critical studies as limited Brazilian literature concerning SEA kept a \'safe distance\' from substantively critiquing the constructions of SEA and its articulations in the Brazilian context. The literature review and the Petrobras\' case illustrate a variety of naming, instituting and articulatory practices that endeavour to maintain the current hegemony of development in an emerging economy, which allows Petrobras to continue to exercise significant profit at the expense of the social and environmental. The constructed idea of development in Petrobras\' discourses emphasises a rhetoric of wider development, but, in reality, these discourses were the antithesis of political, social and ethical developmental issues. These constructions aim to hide struggles between social inequalities and exploitation of natural resources and constitute excuses about a fanciful notion of rhetorical and hegemonic neo-liberal development. In summary, this thesis contributes to the prior literature in five ways: (i) the addition of DT to the analysis of SEA enhances the discussion of political elements such as hegemony, antagonism, logic of equivalence/difference, ideology and articulation; (ii) the analysis of an emerging economy such as Brazil incorporates a new perspective of the discussion of the discourses of SEA and development; (iii) this thesis includes a focus on rhetoric to discuss the maintenance of the status quo; (iv) the holistic structure of the LCE approach enlarges the understanding of the social, political and fantasmatic logics of SEA studies and; (v) this thesis combines an analysis of the literature and the case of Petrobras to characterise and critique the state of the Brazilian academy and its impacts and reflections on the significance of SEA. This thesis, therefore, argues for more critical studies in the Brazilian academy due to the persistence of idea of SEA and development that takes-for-granted deep exclusions and contradictions and provide little space for critiques.

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This course, then, investigates the effects of integration on European citizens as well as the duality of the EU as a competitive and social model. It is sensitive to the involvement of social groups, protest, and domestic politics in the study of market integration. Some of the questions we explore are: What are the effects of regulatory policy-making on social actors, how do such actors’ strategies and behaviors change as a consequence, and how to they overcome their collective action problems? Why is it that the logic of integration has at times followed a logic of “permissive consensus” while at other times it has been described as a “constraining dissensus”? What is the importance of discourse in domestic politics in order to articulate and legitimate Europeanization? How do European identities change as a consequence of policymaking as well as of protest? To what extent do ordinary Europeans matter in terms of accepting and opposing the project of European integration, how do European citizens in core and peripheral EU states experience Europeanization, and how is their involvement in the integration project to be conceptualized?

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Thesis (Ph.D.)--University of Washington, 2016-06

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Impaired insulin action (insulin resistance) is a key factor in the pathogenesis of diabetes mellitus. To investigate therapeutic targets against insulin resistance, this thesis explores the mechanism of action of pharmacological agents and exogenous peptides known or suspected to modify insulin action. These included leptin, a hormone primarily involved in the regulation of body weight; sibutramine, an antiobesity agent; plant-derived compounds (pinitol and chamaemeloside) and agents known to affect insulin sensitivity, e.g. metformin, tolbutamide, thiazolidinediones, vanadyl sulphate and thioctic acid. Models used for investigation included the L6 skeletal muscle cell line and isolated skeletal muscles. In vivo studies were undertaken to investigate glycaemia, insulinaemia, satiety and body weight in streptozotocin-induced diabetic mice and obese (ob/ob) mice. Leptin acutely altered insulin action in skeletal muscle cells via the short form of the leptin receptor. This direct action of leptin was mediated via a pathway involving PI 3-kinase but not Jak2. The active metabolites of sibutramine had antidiabetic properties in vivo and directly improved insulin sensitivity in vitro. This effect appeared to be conducted via a non-PI 3-kinase-mediated increase in protein synthesis with facilitated glucose transport, and was independent of the serotonin and noradrenaline reuptake inhibition produced by sibutramine. Pinitol (a methyl inositol) had an insulin mimetic effect and was an effective glucose-lowering agent in insulinopenic states, acting directly on skeletal muscle. Conversely chamaemeloside appeared to improve glucose tolerance without directly altering glucose transport. Metformin directly increased basal glucose uptake independently of PI 3-kinase, possibly via an increase in the intrinsic activity of glucose transporters. Neither tolbutamide nor thiazolidinediones directly altered insulin sensitivity in L6 skeletal muscle cells: however vanadyl sulphate and thioctic acid increased glucose transport but appeared to exert toxic effects at therapeutic concentrations. Examination of glucose transport in skeletal muscle in this thesis has identified various components of post-receptor insulin signalling pathways which may be targeted to ameliorate insulin resistance. Type 2 Diabetes Mellitus Obesity L6 Skeletal Muscle Cells Glucose Transport Insulin Signalling 2

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French industrial relations were shaken in the spring of 2009 by a series of labour struggles which featured the forcible detention of company managers and threats to commit major acts of sabotage. In this article I focus on the first of these two types of action, placing industrial sequestration in the context of the pattern of collective negotiation processes in France, and comparing it with previous cycles of the same phenomenon, particularly in the post-1968 period. I argue that the current cycle of sequestrations needs to be understood as a response to the deterritorialisation processes of neo-liberal globalisation, and is the product of asymmetries of power between the fixity of labour and the fluidity of global capital. I conclude by arguing that sequestration is a public melodrama of protest which might point to the development of a resistant politics of corporeality in France, in common with struggles in other social and economic sectors.