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A Semantic-Expanding Method for Document RecommendationYang, Yung-Fang 05 August 2002 (has links)
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CALPAIN 2 ACTIVATION, AUTOLYSIS, AND SUBUNIT DISSOCIATIONChou, Jordan 25 October 2010 (has links)
Calpains are calcium-dependent, intracellular, multi-domain cysteine proteases involved in many physiological functions regulated by calcium signaling, including cell motility. How calpains are activated in the cell is still unknown because the resting intracellular concentration of Ca2+ is orders of magnitude lower than that needed for half-maximal activation of the enzyme in vitro.
Several stratagems by which calpains might overcome this Ca2+ concentration differential have been proposed. It is possible that post-translational modifications like phosphorylation, or accessory proteins that bind to calpain, might facilitate the enzyme’s activation at lower than optimal Ca2+ concentrations. Autoproteolysis (autolysis) and subunit dissociation are two other proposed activation mechanisms that could release constraints on the calpain core by breaking the link between the anchor helix and the small subunit to allow the active site to form.
By measuring the rate of autolysis at different sites in calpain, it was demonstrated that while the anchor helix is one of the first targets to be cut, several other potentially inactivating autolysis sites, particularly in Domain III, can also be cleaved within the first minute. Thus autolytic activation would go hand in hand with inactivation. By fractionating and identifying calpain 2 autolysis fragments, I show that the small subunit does not dissociate away from the large subunit, but is proteolyzed to a 40-45 k heterodimer of the penta-EF-hand Domains IV and VI. It is likely that this autolysis-generated heterodimer has previously been misidentified as the small subunit domain VI homodimer that would be produced by subunit dissociation. A calpastatin affinity column was constructed and used to capture recombinant calpain 2 from bacterial cell lysate. This affinity column provides a tool to screen for and capture calpain complexed to potential binding partners in the presence of Ca2+. Here I propose a model for calpain 2 activation in vitro that does not involve autolysis, subunit dissociation, or calpain activators. / Thesis (Master, Biochemistry) -- Queen's University, 2010-10-25 16:03:52.364
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Event-related potentials reveal rapid verification of predicted visual inputDambacher, Michael, Rolfs, Martin, Göllner, Kristin, Kliegl, Reinhold, Jacobs, Arthur M. January 2009 (has links)
Human information processing depends critically on continuous predictions about upcoming events, but the temporal convergence of expectancy-based top-down and input-driven bottom-up streams is poorly understood. We show that, during reading, event-related potentials differ between exposure to highly predictable and unpredictable words no later than 90 ms after visual input. This result suggests an extremely rapid comparison of expected and incoming visual
information and gives an upper temporal bound for theories of top-down and bottom-up interactions in object recognition.
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Beyond Orthographic Segmentation: Neurophysiological Evidence That Pseudo-Derived Word Stems Are Processed SemanticallyHerbert, Theresa 13 March 2009 (has links)
Morphological segmentation while reading is essential for new vocabulary learning. The study's aim was to investigate semantic-level morphological segmentation using event-related brain potentials (ERPs) in typical young adult readers. Past research has suggested that, because semantically opaque words prime their stems (e.g., corner/corn) similarly to transparent words (e.g., farmer/farm), readers recognize complex words from their constituent morphemes without regard to semantic information. However, this priming effect may be due to orthographic and phonological overlap between prime and target words. The research presented here addressed this possibility by creating five conditions in which orthographic, phonological, and semantic relationships between prime and target words were manipulated: Condition 1,wherein prime and target shared no relationship (e.g., inn/brother), served as Control. In Condition 2, prime and target were the same (e.g., brother/brother). In Condition 3, prime was the stem of target (e.g., broth/brother). Condition 4, our critical experimental condition, used primes semantically related to the stem of the target word (e.g., soup/brother). Finally, in Condition 5, prime was semantically related to the whole target word (e.g., sibling/brother). Semantically priming the stem (Condition 4) did not modulate the amplitude of the standard N400 ERP component (as did Conditions 2, 3, and 5), but did affect an early N400-like ERP component peaking in amplitude at ~262 ms after target. Other ERPs were observed that responded uniquely to shared orthography (Conditions 2, 3). Results set the stage for investigating morphological processing in adult reading impairments to evaluate whether, and to what extent, these readers semantically process morphological stems during text comprehension.
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Elbilsägare är väl miljövänliga? : En kvalitativ undersökning av konsumentbeteendet hos elbilsägareSpahic, Adam, Okic, Merdina, Husein, Husein January 2024 (has links)
SAMMANFATTNING Datum: 2024-05-28 datum för slutseminarium Nivå: Kandidatuppsats i Företagsekonomi, 15 hp Institution: Akademin för Ekonomi, Samhälle och Teknik, Mälardalens Universitet Titel: Mer än bara en elbil: En kvalitativ undersökning av konsumentbeteendet hos elbilsägare Handledare: Aswo Safari Författare: Husein Husein Merdina Okic Adam Spahic 000913 020506 030116 Nyckelord: Konsumentbeteende, Elbilar, Miljömedvetenhet, Theory of Planned Behavior (TPB) Value-Belief-Norm (VBN) teori, Norm Activation Model (NAM) Forskningsfråga/or: I vilken utsträckning engagerar sig elbilsägare i andra miljövänliga konsumentbeteenden utöver att äga en elbil? Vilka faktorer påverkar deras konsumentbeteende i relation till miljö? Syfte: Studien syftar till att undersöka huruvida elbilsägares konsumentbeteende innefattar fler miljövänliga beslut utöver val av transportfordon. Metod: Denna studie använder en kvalitativ metodansats, där data samlas in genom semistrukturerade intervjuer med elbilsägare för att förstå deras attityder, motivationer och beteenden. Dessutom används Klimat Kalkylatorn för att analysera respondenternas koldioxidutsläpp och ge en kvantitativ bedömning av deras miljöpåverkan. Slutsats: Elbilsägare visar en viss grad av miljövänligt konsumentbeteende, men deras engagemang i andra miljövänliga beslut påverkas starkt av ekonomiska incitament och praktiska förutsättningar / ABSTRACT Date: 2024-05-28 date for final seminar Level: Bachelor thesis in Business Administration, 15 cr Institution: School of Business, Society and Engineering, Mälardalen University Title: Elbilsägare är väl miljövänliga?: En kvalitativ undersökning av konsumentbeteendet hos elbilsägare Supervisor: Aswo Safari Authors: Husein Husein Merdina Okic Adam Spahic 000913 020506 030116 Keywords: Consumer behavior, electric vehicles, environmental awareness, sustainability, Theory of Planned Behavior (TPB), Value-Belief-Norm (VBN) theory, Norm Activation Model (NAM) Research questions: To what extent do electric vehicle owners engage in other environmentally friendly consumer behaviors beyond owning an electric vehicle?What factors influence their consumer behavior in relation to the environment? Purpose: The study aims to investigate whether electric vehicle owners’ consumer behavior includes more environmentally friendly decisions beyond the choice of transportation vehicle. Method: This study employs a qualitative approach, collecting data through semi-structured interviews with electric vehicle owners to understand their attitudes, motivations, and behaviors. Additionally Klimatkalkylatorn is used to analyze the respondents’ carbon emissions, providing a quantitative assessment of their environmental impact. Conclusion: Electric vehicle owners exhibit a certain degree of environmentally friendly consumer behavior, but their engagement in other green decisions is strongly influenced by economic incentives and practical conditions.
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My Organization Wants Me to Do What? The Effect of Implementing the B-Corp Certification on Employee Pro-Environmental BehaviorBalla, Dorottya, Runesson, Tom January 2019 (has links)
In today’s society, environmental concern might be at a historical peak. 2778 companies in 60 countries have now acquired the Benefit-Corporation (B-Corp) Certification in attempts to demonstrate their environmental responsibility. The aim of the present study was to investigate the effects of implementing the B-Corp Certification in a USA automotive dealership on employee pro-environmental behavior and life satisfaction, with consideration of the moderating role of commitment to the B-Corp Certification. A within-group quasi-experimental design was used to investigate the effects of the certification over a 5-month period through self-reported measures. Thirty-three employees participated in this study. One-way repeated-measures ANOVA was conducted to measure differences in employee pro-environmental behavior before and after the implementation of the B-Corp Certification. Through bivariate correlations the relationship between employee pro-environmental behavior and life satisfaction was analyzed. Partial correlation was used to test the moderating role of commitment in determining the strength of the implementation on employee pro-environmental behavior. There was no difference between pre- and post-measurements of employee pro-environmental behavior. Commitment to the B-Corp Certification did not moderate the effectiveness of the implementation of the B-Corp Certification on employee pro-environmental behavior. Additionally, no relationship was found between pro-environmental behavior and life satisfaction. Finally, results are discussed within the context of industrial- and organizational(IO) psychology, as are the implications for future research and interventions aimed at increasingemployee pro-environmental behaviors.
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Dimensions and Validation of Perceived Message Sensation Value Scale for Print MessagesGrant, Lisanne F. M. 01 January 2014 (has links)
The purpose of this research project was to develop a reliable and valid scale to assess the perceived message sensation value (PMSV) of print messages. The goal of this project was accomplished by conducting two studies. Study one involved collecting 397 undergraduate students’ responses to one high and one low sensation value anti-smoking message, while for study two, 284 undergraduate students’ responses to one high and one low sensation value anti-crystal meth message were collected. The results of the studies highlighted that the PMSV of a print message can be assessed using three dimensions (emotional arousal, novelty, and dramatic impact) and 12 items. Additionally, the newly developed PMSV scale for print messages remained stable across sensation-seeking levels and two different sets of anti-drug messages. Analysis of the data collected also provided support for the convergent, divergent, and predictive validity of the PMSV scale for print messages. Furthermore, from the data it can be inferred that PMSV is an important element that contributes to perceived message effectiveness and attitude towards the ad. The findings associated with this research project also suggest that both high and low sensation seekers preferred high over low sensation value print messages. Lastly, the implications of the PMSV scale for print messages were addressed.
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Principes moléculaires du mécanisme d'activation du récepteur de l'immunité innée RIG-I / Molecular basis of the activation of the cell innate immune receptor RIG-ILouber, Jade 08 November 2013 (has links)
Lors d'une infection virale, l'hôte déclenche une réponse rapide, la rémonse immunitaire innée, dont l'interféron (IFN) de type I est la cytokine centrale. Des motifs moléculaires associés aux micro-organismes (MAMP) sont déteectés par de nombreux récepteurs dédiés, dont les récepteurs cytoplasmiques de type RIG-I (RLR) identifiés à partir de 2004. Les RLR, au nombre de trois, RIG-I, MAD5 et LGP2, sont les ARN-hélicases composées de deux ou trois types de domaines : deux domaines CARD, resposables du recrutement de la cascade de signalisation, un domaine C-terminal CTD, site de liaison initial de l'ARN viral, et le domaine central hélicase, site secondaire de liaison àl'ARN et possédant également une activité enzymatiques ATP-dépendante. RIG-I est impliqué dans la détection de plusieurs virus dont ceux de l'ordre des mononegavirales (virus de la rage, de la rougeole, Ebola). Ce récepteur reconnait des ARN viraux possédant une région double brin adjacente à une extrémité 5'-triphosphate. Les nombreuses études menées n'ont cepnedant pas encore permis de dégager un mécanisme complet et cohérent de l'activation de RIG-I. Notre objectif était donc d'apporter des réponses molécualires quant au mécanismes d'activation de RIG-I. Dans un premier temps, l'élucidation de la structure de la protéine entière RIG-I de canard, par l'équipe de Stephen Cusack, leur a permis d'identifier une conformation auto-réprimée de la protéine. En l'absence d'ARN le domaine CARD2 interagit avec le sous domaine Hel2i du domaine hélicase. Nous avons apporté une preuve fonctionelle de cette observation. Les mutations F540 A/D, du résidu situé dans le sous domaine Hel2i, inhibent l'interaction CARD2-Hel2i et produisent des mutant constituvement actifs. A l'opposé, les mutations correspondantes dans le domaine CARD2 rendent RIG-I inactif. L'interaction CARD2-Hel2i semble donc impliquer une double auto-répression via (i) le masquage du site de liaison à l'ARN du sous-domaine Hel2i, et (ii) le masquage de résidus du domaine CARD2 impliqués dans le recrutement d'intermédiaires requis pour la transduction du signal. Par ailleurs, l'étude de mutants impliqués dans la liaison et l'hydrolyse de l'ATP nous a permis de proposer un nouveau rôle régulateur pour cette activité enzymatique. Dans un deuxième temsp, l'étude de la nécessité de l'oligomérisation de RIG-I pour l'activation de la réponse IFN a été menée. Eva Kowalinski, en thèse dans l'équipe de Stephen Cusack, n'observe la formation de dimères de RIG-I, in vitro, qu'en présence d'un ARN synthétique possédant deux extrémités 5'-triphosphate. Nous avons complété cette observation avec des analyse montrant que des ARN synthéttiques leader incapables d'induire la dimérisation de RIG-I in viro, activent néanmoins ce récepteur in cellula. Par ailleurs, nim'utilisation de la technique de co-immunoprécipitation, ni celle du test de complémentation basé sur la luciférase Gaussia, avec ou sans activiation par un ARN ou une infection virale, n'ont permis d'observer d'oligomérisation de RIG-I. L'auto-association de RIG-I ne semble donc pas être indispensable pour son activation. / Vertebrate are permanently threatened by infections that they manage to counteract using a dedicated system. The innate immunity allows a rapid response against viral infection, mainly through the type I interferon (IFN) production. Dedicated receptors detect microbe-associated molecular patterns (MAMPs), and among them the RIG-likereceptors (RLRs), RIG-I, MDA5 and LGP2, can sense viral RNA into the cytoplasm. RLRs are compossed of two or three different domains : two N-terminal CARDs domains are resposible for signal transduction, a C-terminal domains is the first RNA binding site, and a central helicase domainis the second RNA binding site and possesses an ATP-dependent activity. RIG-I is important for sensing of several mononegavirales, such as rabies, measle and Ebola viruses, and recongnized 5'-triphosphorylated double stranded RNA. Despite intensive studies, a full and comprehensive model of the mechanismof RIG-I activation is still lacking. Our aim was to clarify the first molecular steps of RIG-I activation. First, Stephen Cusack's team elucidated the structure of the full lenght duck RIG-I protein and identified the principle of RIG-I auto-repressed conformation. In absence of ligand RNA, CARD2 domain interacts with Hel2i subdomain of helicase domain. We confirmed this conformation with functional evidence. Mutaions F540A/D, in Hel2i subdomain, inhibits CARD2:Hel2i interaction and renders RIG-I constitutively active. In contrast, the corresponding mutations in the Hel2i contacting site of CARD2 domain produce inactive mutants. Thus CARDS;Hel2i interactio induces an auto-repressed state through a deual masking of both Hel2i RNA binding site and CARD2 residus necessary for signal transduction. Moreover, study of mutants involved in ATP binding and hydrolysis reealed a portential unsuspected regulatory role for the ATP-dependent enzymatic activity of RIG-I. Second, we studied the necessity of RIG-I oligomerization for RIG-I activation. Eva Kowalinski, PhD student in Stephen Cusack's team, observed RIG-I dimers in vitro, only in presence of synthetic RNA with two 5'triphosphorylated ends. We complete this observation with functional assays showing that synthetic leader RNA incapable to induce RIG-I oligomerization in vitro, did activate RIG-I in cellula. Moreover, we did not observe RIG-I oligomerization using either co-immunoprecipitation or Gaussia Luciferase-based-protein complementation assay, after activation with cognate RNA or viral infection. Altogether our results indicate that the self-oligomerization og RIG-I is either dispensable or very transient for signal transduction.
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Biomass-Derived Activated Carbon Through Self-Activation ProcessXia, Changlei 05 1900 (has links)
Self-activation is a process that takes advantage of the gases emitted from the pyrolysis process of biomass to activate the converted carbon. The pyrolytic gases from the biomass contain CO2 and H2O, which can be used as activating agents. As two common methods, both of physical activation using CO2 and chemical activation using ZnCl2 introduce additional gas (CO2) or chemical (ZnCl2), in which the CO2 emission from the activation process or the zinc compound removal by acid from the follow-up process will cause environmental concerns. In comparison with these conventional activation processes, the self-activation process could avoid the cost of activating agents and is more environmentally friendly, since the exhaust gases (CO and H2) can be used as fuel or feedstock for the further synthesis in methanol production. In this research, many types of biomass were successfully converted into activated carbon through the self-activation process. An activation model was developed to describe the changes of specific surface area and pore volume during the activation. The relationships between the activating temperature, dwelling time, yield, specific surface area, and specific pore volume were detailed investigated. The highest specific surface area and pore volume of the biomass-derived activated carbon through the self-activation process were up to 2738 m2 g-1 and 2.209 cm3 g-1, respectively. Moreover, the applications of the activated carbons from the self-activation process have been studied, including lithium-ion battery (LIB) manufacturing, water cleaning, oil absorption, and electromagnetic interference (EMI) shielding.
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A Mixed-Methods Content Analysis Case Study of Frames and Ideologies in Mainstream Environmental NewsKelvin, William 02 December 2019 (has links)
No description available.
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