864 resultados para Motivation and motivational agents


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Technological developments in the information society bring new challenges, both to the applicability and to the enforceability of the law. One major challenge is posed by new entities such as pseudonyms, avatars, and software agents that operate at an increasing distance from the physical persons "behind" them (the "principal"). In case of accidents or misbehavior, current laws require that the physical or legal principal behind the entity be found so that she can be held to account. This may be problematic if the linkability of the principal and the operating entity is questionable. In light of the ongoing developments in electronic agents, there is sufficient reason to conduct a review of the literature in order to more closely examine arguments for and against legal personhood for some nonhuman acting entities. This article also includes a discussion of alternative approaches to solving the "accountability gap."

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We studied the decision making process in the Dictator Game and showed that decisions are the result of a two-step process. In a first step, decision makers generate an automatic, intuitive proposal. Given sufficient motivation and cognitive resources, they adjust this in a second, more deliberated phase. In line with the social intuitionist model, we show that one s Social Value Orientation determines intuitive choice tendencies in the first step, and that this effect is mediated by the dictator s perceived interpersonal closeness with the receiver. Self-interested concerns subsequently leadto a reduction of donation size in step 2. Finally, we show that increasing interpersonal closeness can promote pro-social decision-making.

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BACKGROUND: Virtual reality (VR) simulators are widely used to familiarize surgical novices with laparoscopy, but VR training methods differ in efficacy. In the present trial, self-controlled basic VR training (SC-training) was tested against training based on peer-group-derived benchmarks (PGD-training). METHODS: First, novice laparoscopic residents were randomized into a SC group (n = 34), and a group using PGD-benchmarks (n = 34) for basic laparoscopic training. After completing basic training, both groups performed 60 VR laparoscopic cholecystectomies for performance analysis. Primary endpoints were simulator metrics; secondary endpoints were program adherence, trainee motivation, and training efficacy. RESULTS: Altogether, 66 residents completed basic training, and 3,837 of 3,960 (96.8 %) cholecystectomies were available for analysis. Course adherence was good, with only two dropouts, both in the SC-group. The PGD-group spent more time and repetitions in basic training until the benchmarks were reached and subsequently showed better performance in the readout cholecystectomies: Median time (gallbladder extraction) showed significant differences of 520 s (IQR 354-738 s) in SC-training versus 390 s (IQR 278-536 s) in the PGD-group (p < 0.001) and 215 s (IQR 175-276 s) in experts, respectively. Path length of the right instrument also showed significant differences, again with the PGD-training group being more efficient. CONCLUSIONS: Basic VR laparoscopic training based on PGD benchmarks with external assessment is superior to SC training, resulting in higher trainee motivation and better performance in simulated laparoscopic cholecystectomies. We recommend such a basic course based on PGD benchmarks before advancing to more elaborate VR training.

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There are many case reports of serious complications and death among obstructive sleep apnea patients (OSA) during general anesthesia or postoperative analgesia. Sedatives and anesthetic agents, pharyngeal anatomy of these patients, opiates given for analgesia, and post operative REM sleep rebound represent potential hazards for general anesthesia in OSA patients. Ideally these patients should be treated with continuous positive airway pressure (CPAP) during premedication, directly after extubation and during postoperative analgesia. Unfortunately, only about 20% of these patients are diagnosed before surgery. A special attention should be given to the symptoms and signs suggestive of OSA during preoperative visits. Screening tests should be performed in patients with suspected OSA and, if positive, a treatment should be initiated.

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Enzyme replacement therapy has recently been introduced to treat Fabry disease, a rare X-linked lysosomal storage disorder. The disease occurs due to deficient activity of alpha-galactosidase A, leading to progressive accumulation of globotriaosylceramide in multiple organs and tissues. Renal, cardiac and cerebrovascular manifestations of the disease result in premature death in both hemizygous males and heterozygous females. This paper outlines the clinical signs, symptoms and diagnosis of Fabry disease, and the development of the two available enzyme replacement therapies -- agalsidase alfa and agalsidase beta. Agalsidase alfa and agalsidase beta are produced in a human cell line and in Chinese hamster ovary cells, respectively, resulting in products with the same amino acid sequence as the native human enzyme, but with different patterns of glycosylation. Correct post-translational glycosylation is important in terms of the pharmacokinetics, biodistribution, clinical efficacy and tolerability of genetically engineered protein therapeutics. Differences in glycosylation, which may affect immunogenicity and mannose-6-phosphate receptor-mediated cellular internalisation of administered enzyme, possibly account for the differences in dosing, clinical effects and safety profiles reported for agalsidase alfa and agalsidase beta.

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Radioiodinated murine monoclonal antibodies (Mabs) 81C6, Me 1-14, C12, D12, and E9, made against or reactive with human gliomas but not normal brain, and Mab UJ13A, a pan-neuroectodermal Mab reactive with normal human glial and neural cells, were evaluated in paired label studies in the D-54 MG subcutaneous human glioma xenograft model system in nude mice. Following intravenous injection in the tail vein of mice bearing 200-400 mm3 tumors, specific localization of Mabs to tumor over time (6 h-9 days) was evaluated by tissue counting; each Mab demonstrated a unique localization profile. The comparison of localization indices (LI), determined as a ratio of tissue level of Mab to control immunoglobulin with simultaneous correction for blood levels of each, showed Mabs 81C6 and Me 1-14 to steadily accumulate in glioma xenografts, maintaining LI from 5-20 at 7-9 days after Mab injection. Mab UJ13A peaked at day 1, maintaining this level through day 2, and declining thereafter. Mabs D12 and C12 peaked at days 3 and 4, respectively, and E9 maintained an LI of greater than 3 from days 3-9. Percent injected dose localized/g of tumor varied from a peak high of 16% (81C6) to a low of 5% (Me 1-14 and UJ13A). Immunoperoxidase histochemistry, performed with each Mab on a battery of primary human brain neoplasms, revealed that Mabs 81C6 and E9, which demonstrated the highest levels of percent injected dose localized/g of tumor over time, reacted with antigens expressed in the extracellular matrix. This finding suggests that extracellular matrix localization of antigen represents a biologically significant factor affecting localization and/or binding in the xenograft model used. The demonstration of significant localization, varied kinetics and patterns of localization of this localizing Mab panel warrants their continued investigation as potential imaging and therapeutic agents for human trials.

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Recent progress in neuroscience has yielded major findings regarding brain maturation during adolescence. Unlike the body, which reaches adult size and morphology during this period, the adolescent brain is still maturing. The prefrontal cortex appears to be an important locus of maturational change subserving executive functions that may regulate emotional and motivational issues. The recent expansion of the adolescent period has increased the lag between the onset of emotional and motivational changes activated by puberty and the completion of cognitive development-the maturation of self-regulatory capacities and skills that are continuing to develop long after puberty has occurred. This "disconnect" predicts risk for a broad set of behavioral and emotional problems. Adolescence is a critical period for high-level cognitive functions such as socialization that rely on maturation of the prefrontal cortex. Intervention during the period of adolescent brain development provides opportunities and requires an interdisciplinary approach.

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High performance liquid chromatography (HPLC) is the reference method for measuring concentrations of antimicrobials in blood. This technique requires careful sample preparation. Protocols using organic solvents and/or solid extraction phases are time consuming and entail several manipulations, which can lead to partial loss of the determined compound and increased analytical variability. Moreover, to obtain sufficient material for analysis, at least 1 ml of plasma is required. This constraint makes it difficult to determine drug levels when blood sample volumes are limited. However, drugs with low plasma-protein binding can be reliably extracted from plasma by ultra-filtration with a minimal loss due to the protein-bound fraction. This study validated a single-step ultra-filtration method for extracting fluconazole (FLC), a first-line antifungal agent with a weak plasma-protein binding, from plasma to determine its concentration by HPLC. Spiked FLC standards and unknowns were prepared in human and rat plasma. Samples (240 microl) were transferred into disposable microtube filtration units containing cellulose or polysulfone filters with a 5 kDa cut-off. After centrifugation for 60 min at 15000g, FLC concentrations were measured by direct injection of the filtrate into the HPLC. Using cellulose filters, low molecular weight proteins were eluted early in the chromatogram and well separated from FLC that eluted at 8.40 min as a sharp single peak. In contrast, with polysulfone filters several additional peaks interfering with the FLC peak were observed. Moreover, the FLC recovery using cellulose filters compared to polysulfone filters was higher and had a better reproducibility. Cellulose filters were therefore used for the subsequent validation procedure. The quantification limit was 0.195 mgl(-1). Standard curves with a quadratic regression coefficient &gt; or = 0.9999 were obtained in the concentration range of 0.195-100 mgl(-1). The inter and intra-run accuracies and precisions over the clinically relevant concentration range, 1.875-60 mgl(-1), fell well within the +/-15% variation recommended by the current guidelines for the validation of analytical methods. Furthermore, no analytical interference was observed with commonly used antibiotics, antifungals, antivirals and immunosuppressive agents. Ultra-filtration of plasma with cellulose filters permits the extraction of FLC from small volumes (240 microl). The determination of FLC concentrations by HPLC after this single-step procedure is selective, precise and accurate.

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Bipolar disorder follows a staged trajectory in which persistence of illness is associated with a number of clinical features such as progressive shortening of the inter-episode interval and decreased probability of treatment response. This neuroprogressive clinical process is reflected by both progressive neuroanatomical changes and evidence of cognitive decline. The biochemical foundation of this process appears to incorporate changes in inflammatory cytokines, cortisone, neurotrophins and oxidative stress. There is a growing body of evidence to suggest that these markers may differ between the early and late stages of the disorder. The presence of a series of tangible targets raises the spectre of development of rational neuroprotective strategies, involving judicious use of current therapies and novel agents. Most of the currently used mood stabilisers share effects on oxidative stress and neurotrophins, while novel potentially neuroprotective agents are being developed. These developments need to be combined with service initiatives to maximise the opportunities for early diagnosis and intervention.

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The aims of this study are to consider the experience of flow from a nonlinear dynamics perspective. The processes and temporal nature of intrinsic motivation and flow, would suggest that flow experiences fluctuate over time in a dynamical fashion. Thus it can be argued that the potential for chaos is strong. The sample was composed of 20 employees (both full and part time) recruited from a number of different organizations and work backgrounds. The Experience Sampling Method (ESM) was used for data collection. Once obtained the temporal series, they were subjected to various analyses proper to the com- plexity theory (Visual Recurrence Analysis and Surrogate Data Analysis). Results showed that in 80% of the cases, flow presented a chaotic dynamic, in that, flow experiences delineated a complex dynamic whose patterns of change were not easy to predict. Implications of the study, its limitations and future research are discussed.

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A large variety of cancer vaccines have undergone extensive testing in early-phase clinical trials. A limited number have also been tested in randomized phase II clinical trials. Encouraging trends toward increased survival in the vaccine arms have been recently observed for 2 vaccine candidates in patients with non-small-cell lung cancer. These have provided the impetus for the initiation of phase III trials in large groups of patients with lung cancer. These vaccines target 2 antigens widely expressed in lung carcinomas: melanoma-associated antigen 3, a cancer testis antigen; and mucin 1, an antigen overexpressed in a largely deglycosylated form in advanced tumors. Therapeutic cancer vaccines aim at inducing strong CD8 and CD4 T-cell responses. The majority of vaccines recently tested in phase I clinical trials show efficacy in terms of induction of specific tumor antigen immunity. However, clinical efficacy remains to be determined but appears limited. Efforts are thus aimed at understanding the basis for this apparent lack of effect on tumors. Two major factors are involved. On one hand, current vaccines are suboptimal. Strong adjuvant agents and appropriate tumor antigens are needed. Moreover, dose, route, and schedule also need optimization. On the other hand, it is now clear that large tumors often present a tolerogenic microenvironment that hampers effective antitumor immunity. The partial understanding of the molecular pathways leading to functional inactivation of T cells at tumor sites has provided new targets for intervention. In this regard, blockade of cytotoxic T-lymphocyte antigen-4 and programmed death-1 with humanized monoclonal antibodies has reached the clinical testing stage. In the future, more potent cancer vaccines will benefit from intense research in antigen discovery and adjuvant agents. Furthermore, it is likely that vaccines need to be combined with compounds that reverse major tolerogenic pathways that are constitutively active at the tumor site. Developing these combined approaches to vaccination in cancer promises new, exciting findings and, at the same time, poses important challenges to academic research institutions and the pharmaceutical industry.

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The aim of this article is to estímate price-quality relatíon of Spain resorts from ‘sun and beach’ segment. This study uses initially observed prices, but after obtains net pnces -estimated-, discounting services and characteristics prices. Methodologically, this article is based in hedonic methods, often used in economic analysis. Results show important differences between ‘prices observed’ and ‘adjusted prices’ by services and characteristics. Empirical results obtained in this article should be useful for taking decisions from public and prívate agents

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Avui en dia les Tecnologies de la Informació i la Comunicació (TIC) s’han convertit en eines d’ús quotidià i alhora invisibles en diversos àmbits de la societat i les escoles no n’estan al marge. No cal ensenyar a fer servir eines tecnològiques, sinó que cal entendre-les com un suport. Recerques recents han demostrat que un bon ús d’aquestes potencien un bon ensenyament i aprenentatge. Al mateix temps, es potencien mètodes globalitzats a les aules que permeten construir coneixements significatius a partir de situacions i problemes. Per això, l’objectiu principal d’aquest estudi consisteix en investigar quins canvis s’observen en la motivació de l’alumnat i quins canvis succeeixen a l’aula en general quan s’usen les TIC com a suport en un mètode globalitzat anomenat la recerca del medi. Per tal de resoldre aquest problema d’investigació es recullen diverses dades d’una intervenció didàctica basada en aquest mètode que es porta a terme en dos cursos de cinquè de Primària. Tal com s’observarà, l’ús de les noves tecnologies en un mètode que permet apropar els infants a la realitat n’augmenta la motivació i promou canvis a l’aula que ajuden i faciliten la tasca del docent i alhora afavoreix un aprenentatge significatiu.

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El present estudi de cas se centra en la identificació de les actituds, motivacions i percepcions vers les Tecnologies de la Informació i la Comunicació (TIC) que té el professorat de les escoles La Bressola. Existeix molta documentació del treball en la immersió lingüística de la llengua catalana que fan aquests centres, però no s’ha fet cap estudi que parli de l’ús de les TIC a La Bressola. El constant avenç tecnològic no només implica canvis en la societat, sinó també a nivell educatiu. Per aquest motiu, els docents han d’adaptar-se els nous canvis i saber com integrar els nous recursos digitals dins l’aula per continuar progressant en els processos d’ensenyament i aprenentatge. A través d’una enquesta dirigida al professorat de La Bressola, s’ha vist que els docents de La Bressola mostren una actitud optimista vers l’ús de les TIC, tot i que els principals factors que influeixen per a la bona integració de les eines és la falta de formació i de recursos digitals.

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Modeling the mechanisms that determine how humans and other agents choose among different behavioral and cognitive processes-be they strategies, routines, actions, or operators-represents a paramount theoretical stumbling block across disciplines, ranging from the cognitive and decision sciences to economics, biology, and machine learning. By using the cognitive and decision sciences as a case study, we provide an introduction to what is also known as the strategy selection problem. First, we explain why many researchers assume humans and other animals to come equipped with a repertoire of behavioral and cognitive processes. Second, we expose three descriptive, predictive, and prescriptive challenges that are common to all disciplines which aim to model the choice among these processes. Third, we give an overview of different approaches to strategy selection. These include cost‐benefit, ecological, learning, memory, unified, connectionist, sequential sampling, and maximization approaches. We conclude by pointing to opportunities for future research and by stressing that the selection problem is far from being resolved.