50 resultados para finite-time attractiveness in probability


Relevância:

100.00% 100.00%

Publicador:

Resumo:

QUESTION UNDER STUDY What are the trends in avoidable cancer mortality in Switzerland and neighbouring countries? METHODS Mortality data and population estimates 1996-2010 were obtained from the Swiss Federal Statistical Office for Switzerland and the World Health Organization Mortality Database (http://www.who.int/healthinfo/mortality_data/en/) for Austria, Germany, France and Italy. Age standardised mortality rates (ASMRs, European standard) per 100 000 person-years were calculated for the population <75 years old by sex for the following groups of cancer deaths: (1) avoidable through primary prevention; (2) avoidable through early detection and treatment; (3) avoidable through improved treatment and medical care; and (4) remaining cancer deaths. To assess time trends in ASMRs, estimated annual percentage changes (EAPCs) with 95% confidence intervals (95% CIs) were calculated. RESULTS In Switzerland and neighbouring countries cancer mortality in persons <75 years old continuously decreased 1996-2010. Avoidable cancer mortality decreased in all groups of avoidable cancer deaths in both sexes, with one exception. ASMRs for causes avoidable through primary prevention increased in females in all countries (in Switzerland from 16.2 to 20.3 per 100 000 person years, EAPC 2.0 [95% CI 1.4 to 2.6]). Compared with its neighbouring countries, Switzerland showed the lowest rates for all groups of avoidable cancer mortality in males 2008-2010. CONCLUSION Overall avoidable cancer mortality decreased, indicating achievements in cancer care and related health policies. However, increasing trends in avoidable cancer mortality through primary prevention for females suggest there is a need in Switzerland and its European neighbouring countries to improve primary prevention.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The proposed paper investigates the effect of political education on first-time voting in Switzerland. Theoretically, the paper takes up assumptions of recent research that political education is positively related to political interest, and hence to political participation. Thereby, the paper adds to the literature in two aspects: First, in Switzerland, education is a cantonal matter presenting a unique opportunity to investigate the impact of political education on voting on individual as well as cantonal level. Second, political education is not only measured by political knowledge, but also by civic skills and attitudes acquired in school. Conceptually, the study adopts a multilevel approach permitting a simultaneous testing of the influence of individual and contextual determinants on electoral participation. This paper corresponds closely to the panel topic by examining the important question of how political education affects the voting behaviour of first-time voters not only on individual, but also on contextual level.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND Oesophageal clearance has been scarcely studied. AIMS Oesophageal clearance in endoscopy-negative heartburn was assessed to detect differences in bolus clearance time among patients sub-grouped according to impedance-pH findings. METHODS In 118 consecutive endoscopy-negative heartburn patients impedance-pH monitoring was performed off-therapy. Acid exposure time, number of refluxes, baseline impedance, post-reflux swallow-induced peristaltic wave index and both automated and manual bolus clearance time were calculated. Patients were sub-grouped into pH/impedance positive (abnormal acid exposure and/or number of refluxes) and pH/impedance negative (normal acid exposure and number of refluxes), the former further subdivided on the basis of abnormal/normal acid exposure time (pH+/-) and abnormal/normal number of refluxes (impedance+/-). RESULTS Poor correlation (r=0.35) between automated and manual bolus clearance time was found. Manual bolus clearance time progressively decreased from pH+/impedance+ (42.6s), pH+/impedance- (27.1s), pH-/impedance+ (17.8s) to pH-/impedance- (10.8s). There was an inverse correlation between manual bolus clearance time and both baseline impedance and post-reflux swallow-induced peristaltic wave index, and a direct correlation between manual bolus clearance and acid exposure time. A manual bolus clearance time value of 14.8s had an accuracy of 93% to differentiate pH/impedance positive from pH/impedance negative patients. CONCLUSIONS When manually measured, bolus clearance time reflects reflux severity, confirming the pathophysiological relevance of oesophageal clearance in reflux disease.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Neural dynamic processes correlated over several time scales are found in vivo, in stimulus-evoked as well as spontaneous activity, and are thought to affect the way sensory stimulation is processed. Despite their potential computational consequences, a systematic description of the presence of multiple time scales in single cortical neurons is lacking. In this study, we injected fast spiking and pyramidal (PYR) neurons in vitro with long-lasting episodes of step-like and noisy, in-vivo-like current. Several processes shaped the time course of the instantaneous spike frequency, which could be reduced to a small number (1-4) of phenomenological mechanisms, either reducing (adapting) or increasing (facilitating) the neuron's firing rate over time. The different adaptation/facilitation processes cover a wide range of time scales, ranging from initial adaptation (<10 ms, PYR neurons only), to fast adaptation (<300 ms), early facilitation (0.5-1 s, PYR only), and slow (or late) adaptation (order of seconds). These processes are characterized by broad distributions of their magnitudes and time constants across cells, showing that multiple time scales are at play in cortical neurons, even in response to stationary stimuli and in the presence of input fluctuations. These processes might be part of a cascade of processes responsible for the power-law behavior of adaptation observed in several preparations, and may have far-reaching computational consequences that have been recently described.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Bleeding is a frequent complication during surgery. The intraoperative administration of blood products, including packed red blood cells, platelets and fresh frozen plasma (FFP), is often live saving. Complications of blood transfusions contribute considerably to perioperative costs and blood product resources are limited. Consequently, strategies to optimize the decision to transfuse are needed. Bleeding during surgery is a dynamic process and may result in major blood loss and coagulopathy due to dilution and consumption. The indication for transfusion should be based on reliable coagulation studies. While hemoglobin levels and platelet counts are available within 15 minutes, standard coagulation studies require one hour. Therefore, the decision to administer FFP has to be made in the absence of any data. Point of care testing of prothrombin time ensures that one major parameter of coagulation is available in the operation theatre within minutes. It is fast, easy to perform, inexpensive and may enable physicians to rationally determine the need for FFP. METHODS/DESIGN: The objective of the POC-OP trial is to determine the effectiveness of point of care prothrombin time testing to reduce the administration of FFP. It is a patient and assessor blind, single center randomized controlled parallel group trial in 220 patients aged between 18 and 90 years undergoing major surgery (any type, except cardiac surgery and liver transplantation) with an estimated blood loss during surgery exceeding 20% of the calculated total blood volume or a requirement of FFP according to the judgment of the physicians in charge. Patients are randomized to usual care plus point of care prothrombin time testing or usual care alone without point of care testing. The primary outcome is the relative risk to receive any FFP perioperatively. The inclusion of 110 patients per group will yield more than 80% power to detect a clinically relevant relative risk of 0.60 to receive FFP of the experimental as compared with the control group. DISCUSSION: Point of care prothrombin time testing in the operation theatre may reduce the administration of FFP considerably, which in turn may decrease costs and complications usually associated with the administration of blood products. TRIAL REGISTRATION: NCT00656396.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A publication entitled “A default mode of brain function” initiated a new way of looking at functional imaging data. In this PET study the authors discussed the often-observed consistent decrease of brain activation in a variety of tasks as compared with the baseline. They suggested that this deactivation is due to a task-induced suspension of a default mode of brain function that is active during rest, i.e. that there exists intrinsic well-organized brain activity during rest in several distinct brain regions. This suggestion led to a large number of imaging studies on the resting state of the brain and to the conclusion that the study of this intrinsic activity is crucial for understanding how the brain works. The fact that the brain is active during rest has been well known from a variety of EEG recordings for a very long time. Different states of the brain in the sleep–wake continuum are characterized by typical patterns of spontaneous oscillations in different frequency ranges and in different brain regions. Best studied are the evolving states during the different sleep stages, but characteristic EEG oscillation patterns have also been well described during awake periods (see Chapter 1 for details). A highly recommended comprehensive review on the brain's default state defined by oscillatory electrical brain activities is provided in the recent book by György Buzsaki, showing how these states can be measured by electrophysiological procedures at the global brain level as well as at the local cellular level.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Back-in-time debuggers are extremely useful tools for identifying the causes of bugs, as they allow us to inspect the past states of objects no longer present in the current execution stack. Unfortunately the "omniscient" approaches that try to remember all previous states are impractical because they either consume too much space or they are far too slow. Several approaches rely on heuristics to limit these penalties, but they ultimately end up throwing out too much relevant information. In this paper we propose a practical approach to back-in-time debugging that attempts to keep track of only the relevant past data. In contrast to other approaches, we keep object history information together with the regular objects in the application memory. Although seemingly counter-intuitive, this approach has the effect that past data that is not reachable from current application objects (and hence, no longer relevant) is automatically garbage collected. In this paper we describe the technical details of our approach, and we present benchmarks that demonstrate that memory consumption stays within practical bounds. Furthermore since our approach works at the virtual machine level, the performance penalty is significantly better than with other approaches.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conventional debugging tools present developers with means to explore the run-time context in which an error has occurred. In many cases this is enough to help the developer discover the faulty source code and correct it. However, rather often errors occur due to code that has executed in the past, leaving certain objects in an inconsistent state. The actual run-time error only occurs when these inconsistent objects are used later in the program. So-called back-in-time debuggers help developers step back through earlier states of the program and explore execution contexts not available to conventional debuggers. Nevertheless, even back-in-time debuggers do not help answer the question, ``Where did this object come from?'' The Object-Flow Virtual Machine, which we have proposed in previous work, tracks the flow of objects to answer precisely such questions, but this VM does not provide dedicated debugging support to explore faulty programs. In this paper we present a novel debugger, called Compass, to navigate between conventional run-time stack-oriented control flow views and object flows. Compass enables a developer to effectively navigate from an object contributing to an error back-in-time through all the code that has touched the object. We present the design and implementation of Compass, and we demonstrate how flow-centric, back-in-time debugging can be used to effectively locate the source of hard-to-find bugs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction: Nocturnal dreams can be considered as a kind of simulation of the real world on a higher cognitive level (Erlacher & Schredl, 2008). Within lucid dreams, the dreamer is aware of the dream state and thus able to control the ongoing dream content. Previous studies could demonstrate that it is possible to practice motor tasks during lucid dreams and doing so improved performance while awake (Erlacher & Schredl, 2010). Even though lucid dream practice might be a promising kind of cognitive rehearsal in sports, little is known about the characteristics of actions in lucid dreams. The purpose of the present study was to explore the relationship between time in dreams and wakefulness because in an earlier study (Erlacher & Schredl, 2004) we found that performing squads took lucid dreamers 44.5 % more time than in the waking state while for counting the same participants showed no differences between dreaming and wakefulness. To find out if the task modality, the task length or the task complexity require longer times in lucid dreams than in wakefulness three experiments were conducted. Methods: In the first experiment five proficient lucid dreamers spent two to three non-consecutive nights in the sleep laboratory with polysomnographic recording to control for REM sleep and determine eye signals. Participants counted from 1-10, 1-20 and 1-30 in wakefulness and in their lucid dreams. While dreaming they marked onset of lucidity as well as beginning and end of the counting task with a Left-Right-Left-Right eye movement and reported their dreams after being awakened. The same procedure was used for the second experiment with seven lucid dreamers except that they had to walk 10, 20 or 30 steps. In the third experiment nine participants performed an exercise involving gymnastics elements such as various jumps and a roll. To control for length of the task the gymnastic exercise in the waking state lasted about the same time as walking 10 steps. Results: As a general result we found – as in the study before – that performing a task in the lucid dream requires more time than in wakefulness. This tendency was found for all three tasks. However, there was no difference for the task modality (counting vs. motor task). Also the relative time for the different lengths of the tasks showed no difference. And finally, the more complex motor task (gymnastic routine) did not require more time in lucid dreams than the simple motor task. Discussion/Conclusion: The results showed that there is a robust effect of time in lucid dreams compared to wakefulness. The three experiments could not explain that those differences are caused by task modality, task length or task complexity. Therefore further possible candidates needs to be investigated e.g. experience in lucid dreaming or psychological variables. References: Erlacher, D. & Schredl, M. (2010). Practicing a motor task in a lucid dream enhances subsequent performance: A pilot study. The Sport Psychologist, 24(2), 157-167. Erlacher, D. & Schredl, M. (2008). Do REM (lucid) dreamed and executed actions share the same neural substrate? International Journal of Dream Research, 1(1), 7-13. Erlacher, D. & Schredl, M. (2004). Time required for motor activity in lucid dreams. Perceptual and Motor Skills, 99, 1239-1242.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

If change over time is compared in several groups, it is important to take into account baseline values so that the comparison is carried out under the same preconditions. As the observed baseline measurements are distorted by measurement error, it may not be sufficient to include them as covariate. By fitting a longitudinal mixed-effects model to all data including the baseline observations and subsequently calculating the expected change conditional on the underlying baseline value, a solution to this problem has been provided recently so that groups with the same baseline characteristics can be compared. In this article, we present an extended approach where a broader set of models can be used. Specifically, it is possible to include any desired set of interactions between the time variable and the other covariates, and also, time-dependent covariates can be included. Additionally, we extend the method to adjust for baseline measurement error of other time-varying covariates. We apply the methodology to data from the Swiss HIV Cohort Study to address the question if a joint infection with HIV-1 and hepatitis C virus leads to a slower increase of CD4 lymphocyte counts over time after the start of antiretroviral therapy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A characterization is provided for the von Mises–Fisher random variable, in terms of first exit point from the unit hypersphere of the drifted Wiener process. Laplace transform formulae for the first exit time from the unit hypersphere of the drifted Wiener process are provided. Post representations in terms of Bell polynomials are provided for the densities of the first exit times from the circle and from the sphere.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective: The decreasing proportion of physicians of Swiss origin and the increasing number of part-time jobs in operative medicine might lead to a shortage of physicians in operative disciplines in Switzerland. The objective of the present study was to analyze the current demographic situation in operative medicine in Switzerland. Methods: During the summer of 2011, a 19-item anonymous electronic questionnaire was mailed to all directors of departments in operative medicine in Switzerland. The questionnaire was designed to gather data about the characteristics of the participating departments, the demographics (including the appointment (consultant, attending or resident), the proportion of female and foreign physicians, the latter’s origin, and the number of part-time jobs with a working time between 20 and 90%), and the proportion of vacant posts. Results: Of 775 questionnaires mailed to all directors of departments in operative medicine in Switzerland, 183 (24%) were returned. Overall, 40% were female, and 42% foreign physicians. The proportion of part-time jobs amounted to 17%. Vacant posts were found in 2%. Conclusions: An expansion of study places at the medical universities and of the incentives for the incumbents in operative medicine is necessary to avert a shortage of physicians in Switzerland.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for these condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.