Depth of anesthesia assessment and higher brain function modelling for consciousness

Anaesthesia is the corner stone of modern surgical medicine. Despite a long period of enquire beginning with Snow (1847) anaesthesia remains a field in which there are more questions than answers. This thesis reports findings on threedifferent aspects of anaesthesia. 1. Initially, a method for calculating a population pharmacokinetic model for propofol infusion is described. This method greatly reduced the time required to calculate the model (0.1 seconds per iteration) compared to the NONMEM method (hours per iteration (Minto, Schnider, Egan, Youngs, Lemmens, Gambus,Billard, Hoke, Moore, Hermann, Muir, Mandema & Shafer 1997)). The resultant model achieved improved fit to the data than the model of Schuttler & Ihmsen (2000b) achieving a mean squared error of 0.2835 compared to 0.6413 respectively. 2. Second, a neural network (NN) method is presented to assess Depth of Anaesthesia from long segments of raw EEG. The proposed method was able to approximate the output from a BIS XP monitor for the training data. The linear regression, between the NN and the BIS monitor, resulted in an R value of 0.99963. The network was able to approximate the BIS monitor output for new (unseen) data. 3. Finally, a lumped parameter neural mass, anaesthesia, model is presented. This model is capable of generating changes in EEG associated with increasing doses of Gamma-aminobutyric acid type A (GABA A) hypnotic agent (propofol). This model was not a fitting exercise rather it was constructed based on known brain physiology, and the changes to Alpha1 GABA A receptors conductance caused by propofol. Encompassing the regional interactions, that are thought to be, altered by GABA hypnotic agents. The model is capable of producing five distinct EEG patterns (Beta, Alpha, Theta, Delta and isoelectric) in response to different levels of hypnotic agent. The model is reactive capable of switching from Alpha to Beta band EEG when the eyes open. Anaesthetic supresses the models transition to a higher state EEG. The model suggest that the effect site for propofol as Alpha1 GABA A receptors of slow interneurons of the cortex

Surface Structure Determination of Black Phosphorus Using Photoelectron Diffraction

Atomic structure of single-crystalline black phosphorus was studied by high resolution synchrotron-based photoelectron diffraction (XPD). The results show that the topmost phosphorene layer in the black phosphorus is slightly displaced compared to the bulk structure and presents a small contraction in the direction perpendicular to the surface. Furthermore, the XPD results show the presence of a small buckling among the surface atoms, in agreement with previously reported scanning tunneling microscopy results. The contraction of the surface layer added to the presence of the buckling indicates an uniformity in the size of the sp3 bonds between P atoms at the surface

Training Evaluation in Virtual Worlds: Development of a Model

Many organizations have adopted virtual worlds (VWs) as a setting for training programs; however, research on appropriate evaluation of training in this new setting is incomplete. In this article, we address this gap by first exploring the unique issues relevant to evaluation faced by training designers working in VWs. At the macro-organizational level, the primary issue faced is an organizational culture unreceptive to or otherwise skeptical of VWs. At the micro-organizational level, two major issues are identified: individual trainees unreceptive to VWs and general lack of experience navigating VWs. All three of these challenges and their interrelationships may lead to poor reactions, learning, and transfer from VW-based training despite strong, pedagogically sound training design. Second, we survey the training evaluation research literature, identifying the most well-supported training evaluation models, discussing the suitability of each for evaluating VW-based training. Third, we propose a new integrative model based upon this literature, incorporating solutions to the unique issues faced in VWs with the most relevant portions of the models discussed earlier. Fourth, broad thematic implications of this model are identified and applied to prior VW literature. Finally, we provide specific recommendations to practitioners and researchers to evaluate their VW-based training fully

Energia interfacial e interface de crescimento em sistemas cristal-melt

Orientador: Boyan MutaftschievTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb WataghinResumo: A validade do "método da bolha" é discutido quanto à sua aplicabilidade em medidas do ângulo de contato entre um cristal e seu próprio banho fundido bem como para a observação da morfologia da interface de crescimento em cristais halogenetos alcalinos puxador do "melt". A energia livre interfacial é determinada a partir dos ângulos de contato para cristais de KCl, NaCl e ligas destes dois sais. A observação das Interfaces de crescimento de KCl puro, usando microscopia eletrônica e decoração com ouro mostrou que o "melt" pode ser completamente retirado de superfícies {100}. Crescimento ocorre por nucleação bidimensional e espalhamento de frentes de crescimento. As interfaces são sempre limitadas por superfícies {100}. Observou-se que cristais mistos de KCl e NaCl apresentavam interfaces mais rugosas do que as dos sais puros. Em alguns casos cristalitas com facetas {110} {111} e {11l} apareciam na interface. Crescimento a partir de deslocações "screw" e o mecanismo de espiral não foi detectado em cristais puros e não desempenha papel preponderante mesmo em cristais mistos onde algumas deslocações "screw" foram observadas emergindo na InterfaceAbstract: The validity of the "bubble method" is discussed for the measurements of contact angles between a crystal and its own melt and for the observation of the microscopic morphology of growth interfaces for alkali halide crystals grown from the melt. Values of specific free energy of the crystal melt interface, gSL, are calculated from measurements of contact angles for KCI , NaCl and alloys of these salts. Observation of growth interfaces of pure KCI crystals, using electron microscopy and gold decoration, show that the melt can be completely removed from {100} surfaces. Growth occurs by two dimensional nucleation and by speading of monoatomic or biatomic growth fronts. Interfaces are always limited by {100} surfaces. Mixed crystals of KCI and NaCI tended to have rougher interfaces. In some cases, crystallites with {110}, {111} and {11l} facets appeared at the interface. Dislocation induced spiral growth was not detected at the interfaces of pure crystals and does not play a preponderant role even in mixed crystals where some screw dislocations could be observed immerging at the interfaceDoutoradoFísicaDoutor em Ciência

Crowdsourcing Job Satisfaction Data: Examining the Construct Validity of Glassdoor.com Ratings

Researchers, practitioners, and job seekers now routinely use crowdsourced data about organizations for both decision-making and research purposes. Despite the popularity of such websites, empirical evidence regarding their validity is generally absent. In this study, we tackled this problem by combining two curated datasets: (a) the results of the 2017 Federal Employee Viewpoint Survey (FEVS), which contains facet-level job satisfaction ratings from 407,789 US federal employees, and which we aggregated to the agency level, and (b) current overall and facet ratings of job satisfaction of the federal agencies contained within FEVS from Glassdoor.com as scraped from the Glassdoor application programming interface (API) within a month of the FEVS survey’s administration. Using these data, we examined convergent validity, discriminant validity, and methods effects for the measurement of both overall and facet-level job satisfaction by analyzing a multitrait-multimethod matrix (MTMM). Most centrally, we provide evidence that overall Glassdoor ratings of satisfaction within US federal agencies correlate moderately with aggregated FEVS overall ratings (r = .516), supporting the validity of the overall Glassdoor rating as a measure of overall job satisfaction aggregated to the organizational level. In contrast, the validity of facet-level measurement was not well-supported. Overall, given varying strengths and weaknesses with both Glassdoor and survey data, we recommend the combined use of both traditional and crowdsourced data on organizational characteristics for both research and practice

Traversing barriers - how thyroid hormones pass placental, blood-brain and blood-cerebrospinal fluid barriers

Thyroid hormone is essential for normal human fetal growth and brain development. As the fetal thyroid does not secrete thyroid hormones until about 18 weeks gestation, early fetal brain development depends on passage of maternal hormone across the placenta into the fetal circulation. To reach the fetal brain, maternally derived and endogenously produced thyroid hormone has to cross the blood-brain and blood-cerebrospinal fluid barriers. In this review we will discuss the complex biological barriers (involving membrane transporters, enzymes and distributor proteins) that must be overcome to ensure that the developing human brain has adequate exposure to thyroid hormone

Developing Gamification Research in Information Systems

Gamification, an umbrella term for incorporating game design elements into non-game systems to make them more engaging and productive, is of interest to Information System (IS) communities, because it has wide applications, such as, gamification designs for workplace, learning and health apps, social media, online communities, and the gig economy. As a multidisciplinary research domain, gamification integrates elements of technology, human motivation, task design, human-computer-interface design, and algorithms/AI design, and is a fertile ground for IS researchers with a variety of different background. There are many challenges in conducting gamification research, including how to get started in this highly multidisciplinary domain, how to identify novel issues of practical and theoretical importance, how to navigate gamification design processes and avoid common pitfalls, and how to add theoretical contributions to the literature on gamification science. This panel is designed to bring together a team of experts on gamification research to explore these issues and other related issues from the audience

Satisfaction and Race Influence on Positive Health Choices among Patients at an Urban Community Health Center

Background. Promoting positive health choices is one way to lessen health care disparities in indigent populations. This pilot study investigated satisfaction with the health information received at an urban heath care center for the indigent and its effect on health behaviors. Such information will inform providers on their role in advancing the health center’s quality improvement goals (i.e., goals used to measure the clinic’s performance in providing preventive service information to patients). Methods. A survey was used to determine respondent satisfaction with health care information and whether respondents would make positive health choices based on this information. Results. Respondents (n = 185) were satisfied with the health information received; this was the most consistent predictor of making a lifestyle change. Minority respondents were more likely to get a vaccination, to not start smoking, and to start exercising than non-minority respondents. Conclusion. The results suggested that, for the positive health choices examined, satisfaction with education is very important. For certain positive health choices, race also may play a role. Additional studies should be undertaken linking chronic health problems to patient responses