167 research outputs found
Case Report: A Case of Severe Clinical Deterioration in a Patient With Multiple Sclerosis
Tumefactive multiple sclerosis (MS) is a rare variant of MS that may lead to a rapidly progressive clinical deterioration requiring a multidisciplinary diagnostic workup. Our report describes the diagnostic and therapeutic approach of a rare and extremely severe course of MS. A 51-year-old man with an 8-year history of relapsing-remitting MS (RRMS) was admitted with a subacute progressive left lower limb weakness and deterioration of walking ability. After extensive investigations including repeated MRI, microbiological, serological, cerebrospinal fluid (CSF) studies, and finally brain biopsy, the diagnosis of a tumefactive MS lesion was confirmed. Despite repeated intravenous (IV) steroids as well as plasma exchanges and IV foscarnet and ganciclovir owing to low copy numbers of human herpesvirus 6 (HHV-6) DNA in polymerase chain reaction (PCR) analysis, the patient did not recover. The clinical presentation of tumefactive MS is rare and variable. Brain biopsy for histopathological workup should be considered in immunocompromised patients with rapidly progressive clinical deterioration with brain lesions of uncertain cause
Патриотическое воспитание молодежи на примере малой Родины
В статье поднята важнейшая тема - патриотическое воспитание подрастающего поколения России. Этот вопрос особенно актуален сейчас, учитывая то, что в современном обществе произошла переоценка значимости жизненных ценностей: материальное благополучие стало основным, духовно-нравственное стало вторичным. Авторы анализируют сложившуюся ситуацию, приводят успешные примеры работы с молодежью на примере Юргинского района. В статье даны рекомендации по возрождению патриотического воспитания, как на местном уровне, так и на уровне государства
The 'footloose' mechanism: iceberg decay from hydrostatic stresses
We study a mechanism of iceberg breakup that may act together with the recognized melt and wave-induced decay processes. Our proposal is based on observations from a recent field experiment on a large ice island in Baffin Bay, East Canada. We observed that successive collapses of the overburden from above an unsupported wavecut at the iceberg waterline created a submerged foot fringing the berg. The buoyancy stresses induced by such a foot may be sufficient to cause moderate-sized bergs to break off from the main berg. A mathematical model is developed to test the feasibility of this mechanism. The results suggest that once the foot reaches a critical length, the induced stresses are sufficient to cause calving. The theoretically predicted maximum stable foot length compares well to the data collected in situ. Further, the model provides analytical expressions for the previously observed “rampart-moat” iceberg surface profiles
Молодежь и современные информационные технологии: сборник трудов XVI Международной научно-практической конференции студентов, аспирантов и молодых учёных, 3-7 декабря 2018 г., г. Томск
Сборник содержит доклады, представленные на XVI Международной научно-практической конференции студентов, аспирантов и молодых ученых «Молодежь и современные информационные технологии», прошедшей в Томском политехническом университете на базе Инженерной школы информационных технологий и робототехники. Материалы сборника отражают доклады студентов, аспирантов и молодых ученых, принятые к обсуждению на секциях: «Компьютерное моделирование и интеллектуальный анализ данных», «Автоматизация и управление в технических системах», «Робототехнические и мехатронные системы», «Цифровизация, IT и цифровая экономика», «Компьютерная графика и дизайн». Сборник предназначен для специалистов в области информационных технологий, студентов и аспирантов соответствующих специальностей
Rank one isolated p-minimal subgroups in finite groups
This paper studies, for p a prime, rank one isolated p-minimal subgroups P in a finite group G. Such subgroups share many of the features of the minimal parabolic subgroups in groups of Lie type. The structure of Y, the normal closure in G of O p(P) is determined where O p(P) is the smallest normal subgroup of P such that P/O p(P) is a p-group. We find that if Y≠O p(P) and O p(G)=1, then either Y/Z(Y) is a simple group of Lie type in characteristic p or p≤7 with Y/Z(Y) given by an explicit list. Of particular note is that twenty four out of the twenty six sporadic simple groups arise as possibilities for Y/Z(Y). This may be viewed as giving an overarching framework which brings together the simple groups of Lie type and (most of) the sporadic simple groups. </p
Contingent Valuation and Social Choice
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. How can you measure the net benefits to society from actions that impact environmental resources? An economist's answer is to employ Hicksian consumer surplus, determining the equivalent variation in income that leaves each consumer indifferent to the action. When consumers are rational and consumer surplus can be measured reliably from market demand functions, this is a satisfactory basis for welfare calculation, subject to the customary caveats about distributional equity and consistency if compensation is not actually paid. When externalities, public goods, or informational asymmetries interfere with the determination of consumer surplus from market demand functions, one can try to set up a hypothetical market to elicit an individual's equivalent variation, or willingness-to-pay (WTP). This is called the contingent valuation method (CVM). The approach elicits stated preferences from a sample of consumers using either openended questions that ask directly for WTP, or referendum (closed-ended) questions that present a bid or a sequence of bids to the consumer, and ask for a yes or no vote on whether each bid exceeds the subject's WTP. A single referendum experiment presents only one bid; a double referendum experiment presents a second bid that is conditioned on the subject's response to the first bid, lower if the first response is no and higher if it is yes. Agricultural & Applied Economics Association and Oxford University Press An extensive literature has investigated the use of CVM to value environmental goods, and in recent years has promoted it for evaluation of goods such as endangered species and wilderness areas whose value comes primarily from existence rather than active use.' The typical CVM experiment in environmental economics asks about a single commodity, often with a fairly abbreviated or stylized description that assumes the consumer can draw upon prior knowledge. Typically, there is no training of the consumer to reduce inconsistent (e.g. In assessing CVM, there are three commonsense questions that can be asked: (a) Is the method psychometrically robust, in that results cannot be altered substantively by changes in survey format, questionnaire design, and instructions that should be inconsequential when behavior is driven by maximization of rational preferences? (b) Is the method statistically reliable, in that the distribution of WTP can be estimated with acceptable precision using practical sample sizes? Reliability is a particular issue if CV surveys produce extreme responses with some probability, perhaps due to strategic misrepresentation. (c) Is the method economically sensible, in that the individual preferences measured by CVM are consistent with the logical requirements of rationality (e.g., transitivity), and at least broadly consistent with sensible features of economic preferences (e.g., plausible budget shares and income elasticities)? CVM might fail to meet these criteria because respondents receive incomplete information on the consequences of the available choices, or are given inadequate incentives to be truthful and avoid strategic misrepresentation, or because the experimental design is not sufficiently rich to detect and compensate for systematic and random response errors. Beyond such technical problems, there could be a fundamental failure of CVM if consumers do not have stable, classical preferences for the class of commodities, so that the foundations of Hicksian welfare analysis break down. Intuitively, the further removed a class of commodities from market goods where the consumer has the experience of repeated choices and the discipline of market forces, the greater the possibility of both technical and fundamental failures. The broad sweep of evidence from market research, cognitive psychology, and experimental economics suggests that the existence value of natural resources, involving very complex commodities that are far outside consumers' market experience, will be vulnerable to these failures (McFadden 1986). The following sections discuss, in turn, a series of statistical issues in analyzing WTP data, parametric methods for estimating mean WTP, an experiment that was designed to detect and quantify technical failures of CVM, and the results from the experiment. Using referendum questions complicates matters only slightly, since votes at a sufficiently broad and closely spaced range of bid levels can be used to estimate directly the distribution of WTP, and this in turn can be used to estimate the population mean. This claim is proved in McFadden (1994), which gives practical nonparametric estimators, and describes the restrictions necessary on referendum experimental design for these estimators to have good largesample properties. In overview, the result is that with truthful referendum data there are estimators whose mean square error is inversely proportional to sample size, provided the experimental design "undersmooths" by taking a relatively large number of bid levels, with relatively small samples at each bid.2 For example, when WTP is restricted a priori to a finite interval, one could distribute the bids evenly over this interval, with one respondent at each level. The common practice in CV referendum studies of taking a relatively small number of bid levels leads to estimators whose mean square errors decline more slowly with sample size. Statistical Issues in CV Data 2 When the support of the WTP distribution is not finite, additional restrictions on tail behavior are needed to assure the existence of mean WTP and the stated rate of convergence of nonparametric estimators
Prefrontal cortex activation and young driver behaviour: a fNIRS study
Road traffic accidents consistently show a significant over-representation for young, novice and particularly male drivers. This research examines the prefrontal cortex activation of young drivers and the changes in activation associated with manipulations of mental workload and inhibitory control. It also considers the explanation that a lack of prefrontal cortex maturation is a contributing factor to the higher accident risk in this young driver population. The prefrontal cortex is associated with a number of factors including mental workload and inhibitory control, both of which are also related to road traffic accidents. This experiment used functional near infrared spectroscopy to measure prefrontal cortex activity during five simulated driving tasks: one following task and four overtaking tasks at varying traffic densities which aimed to dissociate workload and inhibitory control. Age, experience and gender were controlled for throughout the experiment. The results showed that younger drivers had reduced prefrontal cortex activity compared to older drivers. When both mental workload and inhibitory control increased prefrontal cortex activity also increased, however when inhibitory control alone increased there were no changes in activity. Along with an increase in activity during overtaking manoeuvres, these results suggest that prefrontal cortex activation is more indicative of workload in the current task. There were no differences in the number of overtakes completed by younger and older drivers but males overtook significantly more than females. We conclude that prefrontal cortex activity is associated with the mental workload required for overtaking. We additionally suggest that the reduced activation in younger drivers may be related to a lack of prefrontal maturation which could contribute to the increased crash risk seen in this population
Case-finding of dementia in general practice and effects of subsequent collaborative care; design of a cluster RCT
<p>Abstract</p> <p>Background</p> <p>In the primary care setting, dementia is often diagnosed relatively late in the disease process. Case finding and proactive collaborative care may have beneficial effects on both patient and informal caregiver by clarifying the cause of cognitive decline and changed behaviour and by enabling support, care planning and access to services.</p> <p>We aim to improve the recognition and diagnosis of individuals with dementia in general practice. In addition to this diagnostic aim, the effects of case finding and subsequent care on the mental health of individuals with dementia and the mental health of their informal carers are explored.</p> <p>Methods and design</p> <p>Design: cluster randomised controlled trial with process evaluation.</p> <p>Participants: 162 individuals ≥ 65 years, in 15 primary care practices, in whom GPs suspect cognitive impairment, but without a dementia diagnosis.</p> <p>Intervention; case finding and collaborative care: 2 trained practice nurses (PNs) invite all patients with suspected cognitive impairment for a brief functional and cognitive screening. If the cognitive tests are supportive of cognitive impairment, individuals are referred to their GP for further evaluation. If dementia is diagnosed, a comprehensive geriatric assessment takes place to identify other relevant geriatric problems that need to be addressed. Furthermore, the team of GP and PN provide information and support.</p> <p>Control: GPs provide care and diagnosis as usual.</p> <p>Main study parameters: after 12 months both groups are compared on: 1) incident dementia (and MCI) diagnoses and 2) patient and caregiver quality of life (QoL-AD; EQ5D) and mental health (MH5; GHQ 12) and caregiver competence to care (SSCQ). The process evaluation concerns facilitating and impeding factors to the implementation of this intervention. These factors are assessed on the care provider level, the care recipient level and on the organisational level.</p> <p>Discussion</p> <p>This study will provide insight into the diagnostic yield and the clinical effects of case finding and collaborative care for individuals with suspected cognitive impairment, compared to usual care. A process evaluation will give insight into the feasibility of this intervention.</p> <p>The first results are expected in the course of 2013.</p> <p>Trial registration</p> <p>NTR3389</p
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