Statistical Learning Is Not Affected by a Prior Bout of Physical Exercise.

Science.gov (United States)

Stevens, David J; Arciuli, Joanne; Anderson, David I

2016-05-01

This study examined the effect of a prior bout of exercise on implicit cognition. Specifically, we examined whether a prior bout of moderate intensity exercise affected performance on a statistical learning task in healthy adults. A total of 42 participants were allocated to one of three conditions-a control group, a group that exercised for 15 min prior to the statistical learning task, and a group that exercised for 30 min prior to the statistical learning task. The participants in the exercise groups cycled at 60% of their respective V˙O2 max. Each group demonstrated significant statistical learning, with similar levels of learning among the three groups. Contrary to previous research that has shown that a prior bout of exercise can affect performance on explicit cognitive tasks, the results of the current study suggest that the physiological stress induced by moderate-intensity exercise does not affect implicit cognition as measured by statistical learning. Copyright © 2015 Cognitive Science Society, Inc.

Cortisol and Brain-Derived Neurotrophic Factor Levels Prior to Treatment in Children With Obsessive-Compulsive Disorder.

Science.gov (United States)

Şimşek, Şeref; Gençoğlan, Salih; Yüksel, Tuğba; Kaplan, İbrahim; Alaca, Rümeysa

2016-07-01

In this study, we investigated serum brain-derived neurotrophic factor (BDNF), adrenocorticotropic hormone (ACTH), and cortisol levels between children with obsessive-compulsive disorder (OCD) prior to treatment and healthy controls. In addition, the study aimed to assess any correlations between OCD symptom severity and BDNF, ACTH, and cortisol levels. Twenty-nine children, aged from 7 to 17 years (male/female: 21/8) and diagnosed with OCD according to DSM-IV prior to treatment, were compared with 25 healthy control subjects (male/female: 16/9). The study was conducted between December 2012 and December 2013. The Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime Version (K-SADS-PL), Children's Yale-Brown Obsessive Compulsive Scale, and Children's Depression Inventory (CDI) were administered to the children. BDNF, ACTH, and cortisol levels were detected using a prepared kit with the enzyme-linked immunosorbent assay method. BDNF, ACTH, and cortisol levels in the OCD group were significantly higher when compared with the control group (P = .02, P = .03, and P = .046, respectively). No association was detected between the severity and duration of OCD symptoms and BDNF, ACTH, and cortisol levels. CDI scores in both groups were similar. The mean (SD) duration of OCD symptoms was 17.9 (18.5) months. Our findings suggest that BDNF levels adaptively increase as a result of the damaging effects of the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity on brain tissue in the early stages of OCD. HPA axis abnormalities and BDNF may play a role in the pathogenesis of the disease. © Copyright 2016 Physicians Postgraduate Press, Inc.

Effect of Prior Cardiopulmonary Resuscitation Knowledge on Compression Performance by Hospital Providers

Directory of Open Access Journals (Sweden)

Joshua N. Burkhardt

2014-07-01

Full Text Available Introduction: The purpose of this study was to determine cardiopulmonary resuscitation (CPR knowledge of hospital providers and whether knowledge affects performance of effective compressions during a simulated cardiac arrest. Methods: This cross-sectional study evaluated the CPR knowledge and performance of medical students and ED personnel with current CPR certification. We collected data regarding compression rate, hand placement, depth, and recoil via a questionnaire to determine knowledge, and then we assessed performance using 60 seconds of compressions on a simulation mannequin. Results: Data from 200 enrollments were analyzed by evaluators blinded to subject knowledge. Regarding knowledge, 94% of participants correctly identified parameters for rate, 58% for hand placement, 74% for depth, and 94% for recoil. Participants identifying an effective rate of ≥100 performed compressions at a significantly higher rate than participants identifying <100 (µ=117 vs. 94, p<0.001. Participants identifying correct hand placement performed significantly more compressions adherent to guidelines than those identifying incorrect placement (µ=86% vs. 72%, p<0.01. No significant differences were found in depth or recoil performance based on knowledge of guidelines. Conclusion: Knowledge of guidelines was variable; however, CPR knowledge significantly impacted certain aspects of performance, namely rate and hand placement, whereas depth and recoil were not affected. Depth of compressions was poor regardless of prior knowledge, and knowledge did not correlate with recoil performance. Overall performance was suboptimal and additional training may be needed to ensure consistent, effective performance and therefore better outcomes after cardiopulmonary arrest.

Precursory changes in well water level prior to the March, 2000 eruption of Usu Volcano, Japan

Science.gov (United States)

Shibata, Tomo; Akita, Fujio

The height of water levels in two wells located near Usu volcano, Japan, changed in a systematic fashion for several months prior to the eruption of Usu volcano on 31 March 2000. In one well, water-level decrease relative to normal levels was first observed at the beginning of October 1999. The decreasing water-level is postulated to result from groundwater flow into cracks widened by intruding magma during dike formation. From the beginning of January 2000, the rate of decrease became higher. During this time, the water level of the second well increased by 0.05 m and then gradually decreased. The water-level changes are consistent with volumetric expansion of magma inside the magma chamber, followed by intrusion of magma into the fracture system associated with widening of cracks. We conclude that water-level observations can provide information that may potentially be used to predict further volcanic eruptions.

Prior contralateral amputation predicts worse outcomes for lower extremity bypasses performed in the intact limb.

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Baril, Donald T; Goodney, Philip P; Robinson, William P; Nolan, Brian W; Stone, David H; Li, YouFu; Cronenwett, Jack L; Schanzer, Andres

2012-08-01

To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb. A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year. Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of

The Effect of Prior Caffeine Consumption on Neuropsychological Test Performance: A Placebo-Controlled Study.

Science.gov (United States)

Walters, Elizabeth R; Lesk, Valerie E

2016-01-01

The aim of this study was to investigate whether the prior consumption of 200 mg of pure caffeine affected neuropsychological test scores in a group of elderly participants aged over 60 years. Using a double-blind placebo versus caffeine design, participants were randomly assigned to receive 200 mg of caffeine or placebo. A neuropsychological assessment testing the domains of general cognitive function, processing speed, semantic memory, episodic memory, executive function, working memory and short-term memory was carried out. Significant interaction effects between age, caffeine and scores of executive function and processing speed were found; participants who had received caffeine showed a decline in performance with increasing age. This effect was not seen for participants who received placebo. The results highlight the need to consider and control prior caffeine consumption when scoring neuropsychological assessments in the elderly, which is important for accuracy of diagnosis and corresponding normative data. © 2016 S. Karger AG, Basel.

Iterated random walks with shape prior

DEFF Research Database (Denmark)

Pujadas, Esmeralda Ruiz; Kjer, Hans Martin; Piella, Gemma

2016-01-01

the parametric probability density function. Then, random walks is performed iteratively aligning the prior with the current segmentation in every iteration. We tested the proposed approach with natural and medical images and compared it with the latest techniques with random walks and shape priors......We propose a new framework for image segmentation using random walks where a distance shape prior is combined with a region term. The shape prior is weighted by a confidence map to reduce the influence of the prior in high gradient areas and the region term is computed with k-means to estimate....... The experiments suggest that this method gives promising results for medical and natural images....

Evaluating the use of prior information under different pacing conditions on aircraft inspection performance: The use of virtual reality technology

Science.gov (United States)

Bowling, Shannon Raye

The aircraft maintenance industry is a complex system consisting of human and machine components, because of this; much emphasis has been placed on improving aircraft-inspection performance. One proven technique for improving inspection performance is the use of training. There are several strategies that have been implemented for training, one of which is feedforward information. The use of prior information (feedforward) is known to positively affect inspection performance. This information can consist of knowledge about defect characteristics (types, severity/criticality, and location) and the probability of occurrence. Although several studies have been conducted that demonstrate the usefulness of feedforward as a training strategy, there are certain research issues that need to be addressed. This study evaluates the effect of feedforward information in a simulated 3-dimensional environment by the use of virtual reality. A controlled study was conducted to evaluate the effectiveness of feedforward information in a simulated aircraft inspection environment. The study was conducted in two phases. The first phase evaluated the difference between general and detailed inspection at different pacing levels. The second phase evaluated the effect of feedforward information pertaining to severity, probability and location. Analyses of the results showed that subjects performing detailed inspection performed significantly better than while performing general inspection. Pacing also had the effect of reducing performance for both general and detailed inspection. The study also found that as the level of feedforward information increases, performance also increases. In addition to evaluating performance measures, the study also evaluated process and subjective measures. It was found that process measures such as number of fixation points, fixation groups, mean fixation duration, and percent area covered were all affected by the treatment levels. Analyses of the subjective

Prior Sensitivity Analysis in Default Bayesian Structural Equation Modeling.

Science.gov (United States)

van Erp, Sara; Mulder, Joris; Oberski, Daniel L

2017-11-27

Bayesian structural equation modeling (BSEM) has recently gained popularity because it enables researchers to fit complex models and solve some of the issues often encountered in classical maximum likelihood estimation, such as nonconvergence and inadmissible solutions. An important component of any Bayesian analysis is the prior distribution of the unknown model parameters. Often, researchers rely on default priors, which are constructed in an automatic fashion without requiring substantive prior information. However, the prior can have a serious influence on the estimation of the model parameters, which affects the mean squared error, bias, coverage rates, and quantiles of the estimates. In this article, we investigate the performance of three different default priors: noninformative improper priors, vague proper priors, and empirical Bayes priors-with the latter being novel in the BSEM literature. Based on a simulation study, we find that these three default BSEM methods may perform very differently, especially with small samples. A careful prior sensitivity analysis is therefore needed when performing a default BSEM analysis. For this purpose, we provide a practical step-by-step guide for practitioners to conducting a prior sensitivity analysis in default BSEM. Our recommendations are illustrated using a well-known case study from the structural equation modeling literature, and all code for conducting the prior sensitivity analysis is available in the online supplemental materials. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Correlation between physics A-levels/A-levels and degree performance

Science.gov (United States)

Chadwick, Roy

1985-09-01

The author presents an analysis of 178 students who left Solihull Sixth form College between 1975 and 1981 to do a degree in physics (approximately one third) or engineering (approximately two thirds) at university or polytechnic. The first table is an analysis of physics A-level grade and degree performance; the second table an analysis of the points total for physics A-level plus maths A-level (five for A, four for B, etc.), against degree performances, and the final table an analysis of the points total for physics A-level plus maths A-level plus third A-level (again five for A, four for B, etc.), against degree performance.

Attentional and Contextual Priors in Sound Perception.

Science.gov (United States)

Wolmetz, Michael; Elhilali, Mounya

2016-01-01

Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated. Both attentional and contextual priors had similarly large but independent impacts on sound detectability, with evidence that listeners tracked and used contextual priors for a variety of sound classes (pure tones, harmonic complexes, and vowels). Further analyses showed that listeners updated their contextual priors rapidly and optimally, given the changing acoustic frequency statistics inherent in the paradigm. A Bayesian Observer model accounted for both attentional and contextual adaptations found with listeners. These results bolster the interpretation of perception as Bayesian inference, and suggest that some effects attributed to selective attention may be a special case of contextual prior integration along a feature axis.

Order-Constrained Reference Priors with Implications for Bayesian Isotonic Regression, Analysis of Covariance and Spatial Models

Science.gov (United States)

Gong, Maozhen

Selecting an appropriate prior distribution is a fundamental issue in Bayesian Statistics. In this dissertation, under the framework provided by Berger and Bernardo, I derive the reference priors for several models which include: Analysis of Variance (ANOVA)/Analysis of Covariance (ANCOVA) models with a categorical variable under common ordering constraints, the conditionally autoregressive (CAR) models and the simultaneous autoregressive (SAR) models with a spatial autoregression parameter rho considered. The performances of reference priors for ANOVA/ANCOVA models are evaluated by simulation studies with comparisons to Jeffreys' prior and Least Squares Estimation (LSE). The priors are then illustrated in a Bayesian model of the "Risk of Type 2 Diabetes in New Mexico" data, where the relationship between the type 2 diabetes risk (through Hemoglobin A1c) and different smoking levels is investigated. In both simulation studies and real data set modeling, the reference priors that incorporate internal order information show good performances and can be used as default priors. The reference priors for the CAR and SAR models are also illustrated in the "1999 SAT State Average Verbal Scores" data with a comparison to a Uniform prior distribution. Due to the complexity of the reference priors for both CAR and SAR models, only a portion (12 states in the Midwest) of the original data set is considered. The reference priors can give a different marginal posterior distribution compared to a Uniform prior, which provides an alternative for prior specifications for areal data in Spatial statistics.

Comparing identically designed grayscale (50 phase level) and binary (5 phase levels) splitters: actual versus modeled performance

Science.gov (United States)

Lizotte, Todd E.; Ohar, Orest P.; Tuttle, Tracie

2006-04-01

Performance of diffractive optics is determined by high-quality design and a suitable fabrication process that can actually realize the design. Engineers who are tasked with developing or implementing a diffractive optic solution into a product need to take into consideration the risks of using grayscale versus binary fabrication processes. In many cases, grayscale design doesn't always provide the best solution or cost benefit during product development. This fabrication dilemma arises when the engineer has to select a source for design and/or fabrication. Engineers come face to face with reality in view of the fact that diffractive optic suppliers tend to provide their services on a "best effort basis". This can be very disheartening to an engineer who is trying to implement diffractive optics. This paper will compare and contrast the design and performance of a 1 to 24 beam, two dimensional; beam splitter fabricated using a fifty (50) phase level grayscale and a five (5) phase level binary fabrication methods. Optical modeling data will be presented showing both designs and the performance expected prior to fabrication. An overview of the optical testing methods used will be discussed including the specific test equipment and metrology techniques used to verify actual optical performance and fabricated dimensional stability of each optical element. Presentation of the two versions of the splitter will include data on fabrication dimensional errors, split beam-to-beam uniformity, split beam-to-beam spatial size uniformity and splitter efficiency as compared to the original intended design performance and models. This is a continuation of work from 2005, Laser Beam Shaping VI.

Analysis of the IJCNN 2007 agnostic learning vs. prior knowledge challenge.

Science.gov (United States)

Guyon, Isabelle; Saffari, Amir; Dror, Gideon; Cawley, Gavin

2008-01-01

We organized a challenge for IJCNN 2007 to assess the added value of prior domain knowledge in machine learning. Most commercial data mining programs accept data pre-formatted in the form of a table, with each example being encoded as a linear feature vector. Is it worth spending time incorporating domain knowledge in feature construction or algorithm design, or can off-the-shelf programs working directly on simple low-level features do better than skilled data analysts? To answer these questions, we formatted five datasets using two data representations. The participants in the "prior knowledge" track used the raw data, with full knowledge of the meaning of the data representation. Conversely, the participants in the "agnostic learning" track used a pre-formatted data table, with no knowledge of the identity of the features. The results indicate that black-box methods using relatively unsophisticated features work quite well and rapidly approach the best attainable performance. The winners on the prior knowledge track used feature extraction strategies yielding a large number of low-level features. Incorporating prior knowledge in the form of generic coding/smoothing methods to exploit regularities in data is beneficial, but incorporating actual domain knowledge in feature construction is very time consuming and seldom leads to significant improvements. The AL vs. PK challenge web site remains open for post-challenge submissions: http://www.agnostic.inf.ethz.ch/.

Blood lipid levels in relation to glucose status in European men and women without a prior history of diabetes: the DECODE Study

DEFF Research Database (Denmark)

Zhang, L.; Qiao, Q.; Tuomilehto, J.

2008-01-01

OBJECTIVE: Dyslipidaemia is present not only in diabetic but also in prediabetic subjects. The purpose of this study is to investigate the relationship between lipid and glucose levels in a large European population without a prior history of diabetes. RESEARCH DESIGN AND METHODS: Data from....... RESULTS: In subjects without a prior history of diabetes, positive relationships were shown between fasting plasma glucose (FPG) and total cholesterol (TC) (beta=0.06 and 0.03, respectively for men and women, p

Sets of priors reflecting prior-data conflict and agreement

NARCIS (Netherlands)

Walter, G.M.; Coolen, F.P.A.; Carvalho, J.P.; Lesot, M.-J.; Kaymak, U.; Vieira, S.; Bouchon-Meunier, B.; Yager, R.R.

2016-01-01

Bayesian inference enables combination of observations with prior knowledge in the reasoning process. The choice of a particular prior distribution to represent the available prior knowledge is, however, often debatable, especially when prior knowledge is limited or data are scarce, as then

Influence of prior intense exercise and cold water immersion in recovery for performance and physiological response during subsequent exercise

DEFF Research Database (Denmark)

Christensen, Peter Møller; Bangsbo, Jens

2016-01-01

) and the influence from prior intense exercise on subsequent performance and physiological response to moderate and maximal exercise with and without the use of cold water immersion (CWI) in recovery (part B). In part A, performance times during eight World championships for male track cyclists were extracted from...... min preceded by an identical warm-up period in both a control setting (CON) and using cold water immersion in recovery (CWI; 15 min at 15°C). Performance was lowered (P

Adaptive aspirations and performance heterogeneity : Attention allocation among multiple reference points

NARCIS (Netherlands)

Blettner, D.P.; He, Z.; Hu, S.; Bettis, R.

Organizations learn and adapt their aspiration levels based on reference points (prior aspiration, prior performance, and prior performance of reference groups). The relative attention that organizations allocate to these reference points impacts organizational search and strategic decisions.

PET image reconstruction using multi-parametric anato-functional priors

Science.gov (United States)

Mehranian, Abolfazl; Belzunce, Martin A.; Niccolini, Flavia; Politis, Marios; Prieto, Claudia; Turkheimer, Federico; Hammers, Alexander; Reader, Andrew J.

2017-08-01

In this study, we investigate the application of multi-parametric anato-functional (MR-PET) priors for the maximum a posteriori (MAP) reconstruction of brain PET data in order to address the limitations of the conventional anatomical priors in the presence of PET-MR mismatches. In addition to partial volume correction benefits, the suitability of these priors for reconstruction of low-count PET data is also introduced and demonstrated, comparing to standard maximum-likelihood (ML) reconstruction of high-count data. The conventional local Tikhonov and total variation (TV) priors and current state-of-the-art anatomical priors including the Kaipio, non-local Tikhonov prior with Bowsher and Gaussian similarity kernels are investigated and presented in a unified framework. The Gaussian kernels are calculated using both voxel- and patch-based feature vectors. To cope with PET and MR mismatches, the Bowsher and Gaussian priors are extended to multi-parametric priors. In addition, we propose a modified joint Burg entropy prior that by definition exploits all parametric information in the MAP reconstruction of PET data. The performance of the priors was extensively evaluated using 3D simulations and two clinical brain datasets of [18F]florbetaben and [18F]FDG radiotracers. For simulations, several anato-functional mismatches were intentionally introduced between the PET and MR images, and furthermore, for the FDG clinical dataset, two PET-unique active tumours were embedded in the PET data. Our simulation results showed that the joint Burg entropy prior far outperformed the conventional anatomical priors in terms of preserving PET unique lesions, while still reconstructing functional boundaries with corresponding MR boundaries. In addition, the multi-parametric extension of the Gaussian and Bowsher priors led to enhanced preservation of edge and PET unique features and also an improved bias-variance performance. In agreement with the simulation results, the clinical results

The Effects of Blood Glucose Levels on Cognitive Performance: A Review of the Literature

Science.gov (United States)

Feldman, Jolene; Barshi, Immanuel

2007-01-01

The purpose of this review paper is to discuss the research literature on the effects of blood glucose levels on executive and non-executive functions in humans. The review begins with a brief description of blood glucose, how it has been studied, previous syntheses of prior studies, and basic results regarding the role of blood glucose on cognitive functioning. The following sections describe work that investigated the effect of blood glucose on both non-executive and executive functions (e.g., sensory processing, psychomotor functioning, attention, vigilance, memory, language and communication, judgement and decision-making, and complex task performance). Within each section, summaries of the findings and challenges to the literature are included. Measurement conversions of blood glucose levels, blood glucose values, and associated symptoms are depicted. References to the types of tests used to investigate blood glucose and cognitive performance are provided. For more detailed descriptions of references within (and in addition to) this paper, an annotated bibliography is also provided. Several moderator variables including individual differences and contextual variables related to the effects of blood glucose levels on performance (e.g., age, gender, time of day, familiarity with the task and symptom awareness, expectancy effects, dose dependent effects, time dependent effects, task specific effects, rising and falling blood glucose levels, and speed and/or accuracy trade-offs) are addressed later in the paper. Some suggestions for future experimental methodologies are also made.

Level-set segmentation of pulmonary nodules in megavolt electronic portal images using a CT prior

International Nuclear Information System (INIS)

Schildkraut, J. S.; Prosser, N.; Savakis, A.; Gomez, J.; Nazareth, D.; Singh, A. K.; Malhotra, H. K.

2010-01-01

Purpose: Pulmonary nodules present unique problems during radiation treatment due to nodule position uncertainty that is caused by respiration. The radiation field has to be enlarged to account for nodule motion during treatment. The purpose of this work is to provide a method of locating a pulmonary nodule in a megavolt portal image that can be used to reduce the internal target volume (ITV) during radiation therapy. A reduction in the ITV would result in a decrease in radiation toxicity to healthy tissue. Methods: Eight patients with nonsmall cell lung cancer were used in this study. CT scans that include the pulmonary nodule were captured with a GE Healthcare LightSpeed RT 16 scanner. Megavolt portal images were acquired with a Varian Trilogy unit equipped with an AS1000 electronic portal imaging device. The nodule localization method uses grayscale morphological filtering and level-set segmentation with a prior. The treatment-time portion of the algorithm is implemented on a graphical processing unit. Results: The method was retrospectively tested on eight cases that include a total of 151 megavolt portal image frames. The method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases. The treatment phase portion of the method has a subsecond execution time that makes it suitable for near-real-time nodule localization. Conclusions: A method was developed to localize a pulmonary nodule in a megavolt portal image. The method uses the characteristics of the nodule in a prior CT scan to enhance the nodule in the portal image and to identify the nodule region by level-set segmentation. In a retrospective study, the method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases studied.

Evaluation of workers' perceived sense of slip and effect of prior knowledge of slipperiness during task performance on slippery surfaces.

Science.gov (United States)

Chiou, S; Bhattacharya, A; Succop, P A

2000-01-01

Forty healthy industrial workers (age: 41.0+/-14.9 years) were tested for postural stability for three simulated tasks: (1) standing upright; (2) rapid trunk movement; and (3) lateral reach during lifting. These tasks were performed on four levels of slippery surfaces under different environmental lighting with new or workers' own old shoes. Prior to postural stability tests, each subject was given the opportunity to assess the surface slipperiness that he or she would encounter in the subsequent postural stability tests. A perceived sense of slip (PSOS) scale was administrated immediately after each test to determine subjects' PSOS. Subjects' postural sway and instability during task performance was determined by using a strain gauge type force platform. Results from this study indicate that subjects who were cautious in assessing surface slipperiness had less postural instability during task performance. Subjects could perceive the likely slips due to the change in task (p=0.0001) and surface slipperiness (p=0.0001). The PSOS scale is reproducible, easy to use, and provides a simple way to evaluate potential slip hazards in the workplace. Results from this study should aid understanding of the factors critical to maintaining postural stability on slippery surfaces, and will help to develop guidelines for safety training and identify slip hazards in the workplace.

Example-driven manifold priors for image deconvolution.

Science.gov (United States)

Ni, Jie; Turaga, Pavan; Patel, Vishal M; Chellappa, Rama

2011-11-01

Image restoration methods that exploit prior information about images to be estimated have been extensively studied, typically using the Bayesian framework. In this paper, we consider the role of prior knowledge of the object class in the form of a patch manifold to address the deconvolution problem. Specifically, we incorporate unlabeled image data of the object class, say natural images, in the form of a patch-manifold prior for the object class. The manifold prior is implicitly estimated from the given unlabeled data. We show how the patch-manifold prior effectively exploits the available sample class data for regularizing the deblurring problem. Furthermore, we derive a generalized cross-validation (GCV) function to automatically determine the regularization parameter at each iteration without explicitly knowing the noise variance. Extensive experiments show that this method performs better than many competitive image deconvolution methods.

Technology Performance Level Assessment Methodology.

Energy Technology Data Exchange (ETDEWEB)

Roberts, Jesse D.; Bull, Diana L; Malins, Robert Joseph; Costello, Ronan Patrick; Aurelien Babarit; Kim Nielsen; Claudio Bittencourt Ferreira; Ben Kennedy; Kathryn Dykes; Jochem Weber

2017-04-01

The technology performance level (TPL) assessments can be applied at all technology development stages and associated technology readiness levels (TRLs). Even, and particularly, at low TRLs the TPL assessment is very effective as it, holistically, considers a wide range of WEC attributes that determine the techno-economic performance potential of the WEC farm when fully developed for commercial operation. The TPL assessment also highlights potential showstoppers at the earliest possible stage of the WEC technology development. Hence, the TPL assessment identifies the technology independent “performance requirements.” In order to achieve a successful solution, the entirety of the performance requirements within the TPL must be considered because, in the end, all the stakeholder needs must be achieved. The basis for performing a TPL assessment comes from the information provided in a dedicated format, the Technical Submission Form (TSF). The TSF requests information from the WEC developer that is required to answer the questions posed in the TPL assessment document.

Automatized spleen segmentation in non-contrast-enhanced MR volume data using subject-specific shape priors

Science.gov (United States)

Gloger, Oliver; Tönnies, Klaus; Bülow, Robin; Völzke, Henry

2017-07-01

To develop the first fully automated 3D spleen segmentation framework derived from T1-weighted magnetic resonance (MR) imaging data and to verify its performance for spleen delineation and volumetry. This approach considers the issue of low contrast between spleen and adjacent tissue in non-contrast-enhanced MR images. Native T1-weighted MR volume data was performed on a 1.5 T MR system in an epidemiological study. We analyzed random subsamples of MR examinations without pathologies to develop and verify the spleen segmentation framework. The framework is modularized to include different kinds of prior knowledge into the segmentation pipeline. Classification by support vector machines differentiates between five different shape types in computed foreground probability maps and recognizes characteristic spleen regions in axial slices of MR volume data. A spleen-shape space generated by training produces subject-specific prior shape knowledge that is then incorporated into a final 3D level set segmentation method. Individually adapted shape-driven forces as well as image-driven forces resulting from refined foreground probability maps steer the level set successfully to the segment the spleen. The framework achieves promising segmentation results with mean Dice coefficients of nearly 0.91 and low volumetric mean errors of 6.3%. The presented spleen segmentation approach can delineate spleen tissue in native MR volume data. Several kinds of prior shape knowledge including subject-specific 3D prior shape knowledge can be used to guide segmentation processes achieving promising results.

Source Localization by Entropic Inference and Backward Renormalization Group Priors

Directory of Open Access Journals (Sweden)

Nestor Caticha

2015-04-01

Full Text Available A systematic method of transferring information from coarser to finer resolution based on renormalization group (RG transformations is introduced. It permits building informative priors in finer scales from posteriors in coarser scales since, under some conditions, RG transformations in the space of hyperparameters can be inverted. These priors are updated using renormalized data into posteriors by Maximum Entropy. The resulting inference method, backward RG (BRG priors, is tested by doing simulations of a functional magnetic resonance imaging (fMRI experiment. Its results are compared with a Bayesian approach working in the finest available resolution. Using BRG priors sources can be partially identified even when signal to noise ratio levels are up to ~ -25dB improving vastly on the single step Bayesian approach. For low levels of noise the BRG prior is not an improvement over the single scale Bayesian method. Analysis of the histograms of hyperparameters can show how to distinguish if the method is failing, due to very high levels of noise, or if the identification of the sources is, at least partially possible.

Prior Elicitation, Assessment and Inference with a Dirichlet Prior

Directory of Open Access Journals (Sweden)

Michael Evans

2017-10-01

Full Text Available Methods are developed for eliciting a Dirichlet prior based upon stating bounds on the individual probabilities that hold with high prior probability. This approach to selecting a prior is applied to a contingency table problem where it is demonstrated how to assess the prior with respect to the bias it induces as well as how to check for prior-data conflict. It is shown that the assessment of a hypothesis via relative belief can easily take into account what it means for the falsity of the hypothesis to correspond to a difference of practical importance and provide evidence in favor of a hypothesis.

Bayesian Image Restoration Using a Large-Scale Total Patch Variation Prior

Directory of Open Access Journals (Sweden)

Yang Chen

2011-01-01

Full Text Available Edge-preserving Bayesian restorations using nonquadratic priors are often inefficient in restoring continuous variations and tend to produce block artifacts around edges in ill-posed inverse image restorations. To overcome this, we have proposed a spatial adaptive (SA prior with improved performance. However, this SA prior restoration suffers from high computational cost and the unguaranteed convergence problem. Concerning these issues, this paper proposes a Large-scale Total Patch Variation (LS-TPV Prior model for Bayesian image restoration. In this model, the prior for each pixel is defined as a singleton conditional probability, which is in a mixture prior form of one patch similarity prior and one weight entropy prior. A joint MAP estimation is thus built to ensure the iteration monotonicity. The intensive calculation of patch distances is greatly alleviated by the parallelization of Compute Unified Device Architecture(CUDA. Experiments with both simulated and real data validate the good performance of the proposed restoration.

Prior academic background and student performance in assessment in a graduate entry programme.

Science.gov (United States)

Craig, P L; Gordon, J J; Clark, R M; Langendyk, V

2004-11-01

This study aims to identify whether non-science graduates perform as well as science graduates in Basic and Clinical Sciences (B & CS) assessments during Years 1-3 of a four-year graduate-entry programme at the University of Sydney (the 'USydMP'). Students were grouped into five categories: Health Professions (HP), Biomedical Sciences (BMS), Other Biology (BIOL), Physical Sciences (PHYS) or Non-Science (NONS). We examined the performance rank of students in each of the five groups for single best answer (SBA) and modified essay (MEQ) assessments separately, and also calculated the relative risk of failure in the summative assessments in Years 2 and 3. Students with science-based prior degrees performed better in the SBA assessments. The same occurred initially in the MEQs, but the effect diminished with time. The HP students performed consistently better but converged with other groups over time, particularly in the MEQs. Relative performance by the NONS students improved with time in both assessment formats. Overall, differences between the highest and lowest groups were small and very few students failed to meet the overall standard for the summative assessments. HP and BMS students had the lowest failure rate. NONS students were more likely to fail the assessments in Year 2 and 3, but their pass rates were still high. Female students performed significantly better overall at the end of Year 2 and in Year 3. There were only minor differences between Australian resident and International students. While there are small differences in performance in B & CS early in the programme, these lessen with time. The study results will inform decisions regarding timing of summative assessments, selection policy and for providing additional support to students who need it to minimize their risk of failure. Readers should note that this paper refers to student performance in only one of the four curriculum themes, where health professional and science graduates would be

Exploration and Exploitation Fit and Performance in International Strategic Alliances

DEFF Research Database (Denmark)

Nielsen, Bo Bernhard; Gudergan, Siegfried

2012-01-01

antithetical) strategies with different antecedents and performance consequences. Our results show that while competency similarity is conducive to upstream innovative performance, prior experience with the partner is potentially damaging for this type of performance and trust and cultural distance do not play...... significant roles. When the motive is efficiency and downstream market performance, prior experience with the partner instead is beneficial, as are high levels of trust and low levels of cultural distance. These findings have key implications for literature on strategic fit and alliance performance....

Prior expectations facilitate metacognition for perceptual decision.

Science.gov (United States)

Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

2015-09-01

The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition. Copyright © 2015 Elsevier Inc. All rights reserved.

Random walks with shape prior for cochlea segmentation in ex vivo μCT

DEFF Research Database (Denmark)

Ruiz Pujadas, Esmeralda; Kjer, Hans Martin; Piella, Gemma

2016-01-01

Purpose Cochlear implantation is a safe and effective surgical procedure to restore hearing in deaf patients. However, the level of restoration achieved may vary due to differences in anatomy, implant type and surgical access. In order to reduce the variability of the surgical outcomes, we...... propose a new framework for cochlea segmentation in ex vivo μCT images using random walks where a distance-based shape prior is combined with a region term estimated by a Gaussian mixture model. The prior is also weighted by a confidence map to adjust its influence according to the strength of the image...... contour. Random walks is performed iteratively, and the prior mask is aligned in every iteration. Results We tested the proposed approach in ten μCT data sets and compared it with other random walks-based segmentation techniques such as guided random walks (Eslami et al. in Med Image Anal 17...

Prospective regularization design in prior-image-based reconstruction

International Nuclear Information System (INIS)

Dang, Hao; Siewerdsen, Jeffrey H; Stayman, J Webster

2015-01-01

Prior-image-based reconstruction (PIBR) methods leveraging patient-specific anatomical information from previous imaging studies and/or sequences have demonstrated dramatic improvements in dose utilization and image quality for low-fidelity data. However, a proper balance of information from the prior images and information from the measurements is required (e.g. through careful tuning of regularization parameters). Inappropriate selection of reconstruction parameters can lead to detrimental effects including false structures and failure to improve image quality. Traditional methods based on heuristics are subject to error and sub-optimal solutions, while exhaustive searches require a large number of computationally intensive image reconstructions. In this work, we propose a novel method that prospectively estimates the optimal amount of prior image information for accurate admission of specific anatomical changes in PIBR without performing full image reconstructions. This method leverages an analytical approximation to the implicitly defined PIBR estimator, and introduces a predictive performance metric leveraging this analytical form and knowledge of a particular presumed anatomical change whose accurate reconstruction is sought. Additionally, since model-based PIBR approaches tend to be space-variant, a spatially varying prior image strength map is proposed to optimally admit changes everywhere in the image (eliminating the need to know change locations a priori). Studies were conducted in both an ellipse phantom and a realistic thorax phantom emulating a lung nodule surveillance scenario. The proposed method demonstrated accurate estimation of the optimal prior image strength while achieving a substantial computational speedup (about a factor of 20) compared to traditional exhaustive search. Moreover, the use of the proposed prior strength map in PIBR demonstrated accurate reconstruction of anatomical changes without foreknowledge of change locations in

Lymphography prior to laparoscopic Palomo varicocelectomy to prevent postoperative hydrocele.

Science.gov (United States)

Chiarenza, Salvatore F; D'Agostino, Sergio; Scarpa, Mariagrazia; Fabbro, Mariangelica; Costa, Lorenzo; Musi, Luciano

2006-08-01

We report our experience with preoperative lymphography to identify and perioperatively preserve the ligature of the lymphatic vessels to reduce the incidence of postoperative testicular hydrocele in patients undergoing laparoscopic Palomo varicocelectomy for adolescent varicocele. Twenty-seven consecutive patients with varicocele had preoperative lymphography. The mean age was 13.5 years (range, 8-18 years) and the mean grade of varicocele was III. We performed lymphography with intrascrotal isosulfan blue. The laparoscopic Palomo procedure was successfully carried out in all patients. In 17 patients (63%) we were able to identify and conserve the lymphatic vessels by lymphography. Mean follow-up was 9.5 months (range, 6-24 months). None of the 27 patients had a recurrence. None of the 17 patients with positive lymphography had a testicular hydrocele. One of the 10 remaining patients developed a sizable hydrocele. Preoperative lymphography prior to laparoscopic Palomo varicocelectomy is a simple and feasible method for preventing testicular hydrocele. However, the method should be standardized to identify the exact site, the correct level of injection of blue dye, and to determine the optimal time to perform lymphography prior to the procedure.

Assessment of prior learning in vocational education and training

DEFF Research Database (Denmark)

Wahlgren, Bjarne; Aarkrog, Vibe

’ knowledge, skills and competences during the students’ performances and the methods that the teachers apply in order to assess the students’ prior learning in relation to the regulations of the current VET-program. In particular the study focuses on how to assess not only the students’ explicated knowledge......The article deals about the results of a study of the assessment of prior learning among adult workers who want to obtain formal qualifications as skilled workers. The study contributes to developing methods for assessing prior learning including both the teachers’ ways of eliciting the students...... and skills but also their competences, i.e. the way the students use their skills and knowledge to perform in practice. Based on a description of the assessment procedures the article discusses central issues in relation to the assessment of prior learning. The empirical data have been obtained in the VET...

Task Difficulty and Prior Videogame Experience: Their Role in Performance and Motivation in Instructional Videogames

National Research Council Canada - National Science Library

Orvis, Karin A; Horn, Daniel B; Belanich, James

2007-01-01

.... Further, the influence of prior video game experience on these learning outcomes was examined, as well as the role prior experience played in determining the optimal approach for adjusting task difficulty...

(Biased) Grading of Students’ Performance: Students’ Names, Performance Level, and Implicit Attitudes

Science.gov (United States)

Bonefeld, Meike; Dickhäuser, Oliver

2018-01-01

Biases in pre-service teachers’ evaluations of students’ performance may arise due to stereotypes (e.g., the assumption that students with a migrant background have lower potential). This study examines the effects of a migrant background, performance level, and implicit attitudes toward individuals with a migrant background on performance assessment (assigned grades and number of errors counted in a dictation). Pre-service teachers (N = 203) graded the performance of a student who appeared to have a migrant background statistically significantly worse than that of a student without a migrant background. The differences were more pronounced when the performance level was low and when the pre-service teachers held relatively positive implicit attitudes toward individuals with a migrant background. Interestingly, only performance level had an effect on the number of counted errors. Our results support the assumption that pre-service teachers exhibit bias when grading students with a migrant background in a third-grade level dictation assignment. PMID:29867618

(Biased Grading of Students’ Performance: Students’ Names, Performance Level, and Implicit Attitudes

Directory of Open Access Journals (Sweden)

Meike Bonefeld

2018-05-01

Full Text Available Biases in pre-service teachers’ evaluations of students’ performance may arise due to stereotypes (e.g., the assumption that students with a migrant background have lower potential. This study examines the effects of a migrant background, performance level, and implicit attitudes toward individuals with a migrant background on performance assessment (assigned grades and number of errors counted in a dictation. Pre-service teachers (N = 203 graded the performance of a student who appeared to have a migrant background statistically significantly worse than that of a student without a migrant background. The differences were more pronounced when the performance level was low and when the pre-service teachers held relatively positive implicit attitudes toward individuals with a migrant background. Interestingly, only performance level had an effect on the number of counted errors. Our results support the assumption that pre-service teachers exhibit bias when grading students with a migrant background in a third-grade level dictation assignment.

Physicians' attentional performance following a 24-hour observation period: do we need to regulate sleep prior to work?

Science.gov (United States)

Smyth, P; Maximova, K; Jirsch, J D

2017-08-01

The tradition of physicians working while sleep deprived is increasingly criticised. Medical regulatory bodies have restricted resident physician duty-hours, not addressing the greater population of physicians. We aimed to assess factors such as sleep duration prior to a 24-hour observation period on physicians' attention. We studied 70 physicians (mean age 38 years old (SD 10.8 years)): 36 residents and 34 faculty from call rosters at the University of Alberta. Among 70 physicians, 52 (74%) performed overnight call; 18 did not perform overnight call and were recruited to control for the learning effect of repetitive neuropsychological testing. Attentional Network Test (ANT) measured physicians' attention at the beginning and end of the 24-hour observation period. Participants self-reported ideal sleep needs, sleep duration in the 24 hours prior to (ie, baseline) and during the 24-hour observation period (ie, follow-up). Median regression models examined effects on ANT parameters. Sleep deprivation at follow-up was associated with reduced attentional accuracy following the 24-hour observation period, but only for physicians more sleep deprived at baseline. Other components of attention were not associated with sleep deprivation after adjusting for repetitive testing. Age, years since medical school and caffeine use did not impact changes in ANT parameters. Our study suggests that baseline sleep before 24 hours of observation impacts the accuracy of physicians' attentional testing at 24 hours. Further study is required to determine if optimising physician sleep prior to overnight call shifts is a sustainable strategy to mitigate the effects of sleep deprivation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Role of strategies and prior exposure in mental rotation.

Science.gov (United States)

Cherney, Isabelle D; Neff, Nicole L

2004-06-01

The purpose of these two studies was to examine sex differences in strategy use and the effect of prior exposure on the performance on Vandenberg and Kuse's 1978 Mental Rotation Test. A total of 152 participants completed the spatial task and self-reported their strategy use. Consistent with previous studies, men outperformed women. Strategy usage did not account for these differences, although guessing did. Previous exposure to the Mental Rotation Test, American College Test scores and frequent computer or video game play predicted performance on the test. These results suggest that prior exposure to spatial tasks may provide cues to improve participants' performance.

Penalised Maximum Likelihood Simultaneous Longitudinal PET Image Reconstruction with Difference-Image Priors.

Science.gov (United States)

Ellis, Sam; Reader, Andrew J

2018-04-26

Many clinical contexts require the acquisition of multiple positron emission tomography (PET) scans of a single subject, for example to observe and quantify changes in functional behaviour in tumours after treatment in oncology. Typically, the datasets from each of these scans are reconstructed individually, without exploiting the similarities between them. We have recently shown that sharing information between longitudinal PET datasets by penalising voxel-wise differences during image reconstruction can improve reconstructed images by reducing background noise and increasing the contrast-to-noise ratio of high activity lesions. Here we present two additional novel longitudinal difference-image priors and evaluate their performance using 2D simulation studies and a 3D real dataset case study. We have previously proposed a simultaneous difference-image-based penalised maximum likelihood (PML) longitudinal image reconstruction method that encourages sparse difference images (DS-PML), and in this work we propose two further novel prior terms. The priors are designed to encourage longitudinal images with corresponding differences which have i) low entropy (DE-PML), and ii) high sparsity in their spatial gradients (DTV-PML). These two new priors and the originally proposed longitudinal prior were applied to 2D simulated treatment response [ 18 F]fluorodeoxyglucose (FDG) brain tumour datasets and compared to standard maximum likelihood expectation-maximisation (MLEM) reconstructions. These 2D simulation studies explored the effects of penalty strengths, tumour behaviour, and inter-scan coupling on reconstructed images. Finally, a real two-scan longitudinal data series acquired from a head and neck cancer patient was reconstructed with the proposed methods and the results compared to standard reconstruction methods. Using any of the three priors with an appropriate penalty strength produced images with noise levels equivalent to those seen when using standard

Determination of some organophosphorus pesticides in water and watermelon samples by microextraction prior to high-performance liquid chromatography.

Science.gov (United States)

Wang, Chun; Wu, Qiuhua; Wu, Chunxia; Wang, Zhi

2011-11-01

A novel method based on simultaneous liquid-liquid microextraction and carbon nanotube reinforced hollow fiber microporous membrane solid-liquid phase microextraction has been developed for the determination of six organophosphorus pesticides, i.e. isocarbophos, phosmet, parathion-methyl, triazophos, fonofos and phoxim, in water and watermelon samples prior to high-performance liquid chromatography (HPLC). Under the optimum conditions, the method shows a good linearity within a range of 1-200 ng/mL for water samples and 5-200 ng/g for watermelon samples, with the correlation coefficients (r) varying from 0.9990 to 0.9997 and 0.9986 to 0.9995, respectively. The limits of detection (LODs) were in the range between 0.1 and 0.3 ng/mL for water samples and between 1.0 and 1.5 ng/g for watermelon samples. The recoveries of the method at spiking levels of 5.0 and 50.0 ng/mL for water samples were between 85.4 and 100.8%, and at spiking levels of 5.0 and 50.0 ng/g for watermelon samples, they were between 82.6 and 92.4%, with the relative standard deviations (RSDs) varying from 4.5-6.9% and 5.2-7.4%, respectively. The results suggested that the developed method represents a simple, low-cost, high analytes preconcentration and excellent sample cleanup procedure for the determination of organophosphorus pesticides in water and watermelon samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Moderation Effects of Personality and Organizational Support on the Relationship between Prior Job Experience and Academic Performance of Management Students

Science.gov (United States)

Uppal, Nishant; Mishra, Sushanta Kumar

2014-01-01

The study investigates the relationship between prior job experience and current academic performance among management students in India. It further explores the impact of individual and situational factors on the above relationship. Based on a longitudinal study spanning over nine months in the academic year 2010-11 among a sample of 324…

Effect of the Level of Coordinated Motor Abilities on Performance in Junior Judokas

Science.gov (United States)

Lech, Grzegorz; Jaworski, Janusz; Lyakh, Vladimir; Krawczyk, Robert

2011-01-01

The main focus of this study was to identify coordinated motor abilities that affect fighting methods and performance in junior judokas. Subjects were selected for the study in consideration of their age, competition experience, body mass and prior sports level. Subjects’ competition history was taken into consideration when analysing the effectiveness of current fight actions, and individual sports level was determined with consideration to rank in the analysed competitions. The study sought to determine the level of coordinated motor abilities of competitors. The scope of this analysis covered the following aspects: kinaesthetic differentiation, movement frequency, simple and selective reaction time (evoked by a visual or auditory stimulus), spatial orientation, visual-motor coordination, rhythmization, speed, accuracy and precision of movements and the ability to adapt movements and balance. A set of computer tests was employed for the analysis of all of the coordination abilities, while balance examinations were based on the Flamingo Balance Test. Finally, all relationships were determined based on the Spearman’s rank correlation coefficient. It was observed that the activity of the contestants during the fight correlated with the ability to differentiate movements and speed, accuracy and precision of movement, whereas the achievement level during competition was connected with reaction time. PMID:23486723

What do PSA changes after radiotherapy with or without prior androgen deprivation mean?

International Nuclear Information System (INIS)

Denham, J.W.; Woodhead, D.; Lamb, D.S.; Duchesne, G.

2003-01-01

The TROG 96.01 randomised patients with Stage B2 and C prostate cancer to radiotherapy alone to 66 Gy (RT), 3 months maximal androgen deprivation (MAD) with goserelin and flutamide prior to and during RT, and 6 months MAD prior to and during RT. Minimum follow up time is now 3 years. Prior to preliminary analysis of one of the trial's main endpoints biochemical relapse free survival (bRFS), the prostate-specific antigen (PSA) time course for every patient was evaluated to assess the performance of the ASTRO definition of biochemical failure (BF). Following MAD and RT PSA levels immediately rise in the majority of cases (PSA 'rebound'). In over 50% of cases, PSA levels then plateau at <1 ng/ml for 2 - 3 years prior to clear evidence of failure. Premature diagnosis of BF is possible in some of these cases. Fluctuations in PSA level ('bouncing') are more frequent after MAD and RT. As a result there can be difficulty in interpreting the ASTRO definition of BF in cases where overall PSA trend is upwards shortly after completion of therapy. In patients experiencing BF, the rate of PSA rise often corresponds to the site of failure. PSA doubling times (DT) under 7 months are usually associated with development of bony metastases, while DTs greater than that are usually associated with local failure. Decline in PSA levels following RT alone is frequently not mono-exponential and patients with those patterns experience lower PSA nadir levels and are subject to lower risks of all forms of relapse. These patients also survive longer. In cases where PSA descent patterns are discernable after MAD and RT, opposite trends are seen. Caution is necessary in diagnosing BF after MAD plus RT. Variations in the natural history of prostate cancer are reflected by variations in the rate of PSA changes following therapy. The importance of monitoring this marker and evaluating its time course is emphasised. Prospective studies are needed

Testability evaluation using prior information of multiple sources

Institute of Scientific and Technical Information of China (English)

Wang Chao; Qiu Jing; Liu Guanjun; Zhang Yong

2014-01-01

Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR) and fault isolation rate (FIR), which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testabil-ity demonstration test data (TDTD) such as low evaluation confidence and inaccurate result, a test-ability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF), and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

False recognition depends on depth of prior word processing: a magnetoencephalographic (MEG) study.

Science.gov (United States)

Walla, P; Hufnagl, B; Lindinger, G; Deecke, L; Imhof, H; Lang, W

2001-04-01

Brain activity was measured with a whole head magnetoencephalograph (MEG) during the test phases of word recognition experiments. Healthy young subjects had to discriminate between previously presented and new words. During prior study phases two different levels of word processing were provided according to two different kinds of instructions (shallow and deep encoding). Event-related fields (ERFs) associated with falsely recognized words (false alarms) were found to depend on the depth of processing during the prior study phase. False alarms elicited higher brain activity (as reflected by dipole strength) in case of prior deep encoding as compared to shallow encoding between 300 and 500 ms after stimulus onset at temporal brain areas. Between 500 and 700 ms we found evidence for differences in the involvement of neural structures related to both conditions of false alarms. Furthermore, the number of false alarms was found to depend on depth of processing. Shallow encoding led to a higher number of false alarms than deep encoding. All data are discussed as strong support for the ideas that a certain level of word processing is performed by a distinct set of neural systems and that the same neural systems which encode information are reactivated during the retrieval.

Prior-based artifact correction (PBAC) in computed tomography

International Nuclear Information System (INIS)

Heußer, Thorsten; Brehm, Marcus; Ritschl, Ludwig; Sawall, Stefan; Kachelrieß, Marc

2014-01-01

Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data

Use of the oral sugar test in ponies when performed with or without prior fasting.

Science.gov (United States)

Knowles, E J; Harris, P A; Elliott, J; Menzies-Gow, N J

2017-07-01

It is recommended that the oral sugar test (OST) for insulin dysregulation (ID) be performed after an overnight fast, but fasting is impractical in ponies kept solely at pasture. There are few data on OST repeatability and reliability in ponies. To report 1) whether OST results obtained in the morning after an overnight fast or without fasting in the afternoon (FASTING/FED) can be used interchangeably, 2) time of highest insulin concentration T max [insulin], repeatability and reliability of insulin response to the OST when FASTING or FED and 3) dichotomous agreement (ID/normal) within a small sample when FASTING or FED. Method comparison study. Oral sugar tests were performed on four occasions in 10 adult native British ponies, twice FASTING and twice FED. Insulin concentrations were measured by radioimmunoassay at 0-120 min (T 0,30,60,75,90,120 ). Differences between FASTING and FED results were assessed using mixed effects models. Indices of repeatability and reliability were calculated; dichotomous agreement was reported using kappa statistics. Serum [insulin] was significantly (P≤0.05) higher at T 60 -T 90 with prior fasting (estimated differences [95% confidence intervals]): T 60 : 23.5 μiu/ml (8.7-38.4 μiu/ml), T 75 : 27.1 μiu/ml (12.3-41.8 μiu/ml), T 90 : 15.1 (0.36-29.9 μiu/ml). Most frequently, T max [ins] occurred at T 30 . At any single time point, within-subject coefficients of variation were: FASTING: 40% and FED: 31%. The 95% limits for repeatability were FASTING: 29-340%, FED: 41-240%. Test reliabilities were FASTING: 0.70 and FED: 0.67. For dichotomous interpretation similar results (kappa = 0.7) were obtained using cut-offs of [Insulin] >60 μiu/ml at T 60 or T 90 for FASTING and [Insulin] >51 μiu/ml at T 30 or T 60 for FED samples. Oral sugar tests were performed on a small number of animals on one pasture during one season (spring). Clinicians should beware of interpreting changes in absolute OST results owing to poor repeatability. When

Moderation of prior exposure to trauma on the inverse relationship between callous-unemotional traits and amygdala responses to fearful expressions: an exploratory study.

Science.gov (United States)

Meffert, Harma; Thornton, Laura C; Tyler, Patrick M; Botkin, Mary L; Erway, Anna K; Kolli, Venkata; Pope, Kayla; White, Stuart F; Blair, R James R

2018-02-12

Previous work has shown that amygdala responsiveness to fearful expressions is inversely related to level of callous-unemotional (CU) traits (i.e. reduced guilt and empathy) in youth with conduct problems. However, some research has suggested that the relationship between pathophysiology and CU traits may be different in those youth with significant prior trauma exposure. In experiment 1, 72 youth with varying levels of disruptive behavior and trauma exposure performed a gender discrimination task while viewing morphed fear expressions (0, 50, 100, 150 fear) and Blood Oxygenation Level Dependent responses were recorded. In experiment 2, 66 of these youth performed the Social Goals Task, which measures self-reports of the importance of specific social goals to the participant in provoking social situations. In experiment 1, a significant CU traits-by-trauma exposure interaction was observed within right amygdala; fear intensity-modulated amygdala responses negatively predicted CU traits for those youth with low levels of trauma but positively predicted CU traits for those with high levels of trauma. In experiment 2, a bootstrapped model revealed that the indirect effect of fear intensity amygdala response on social goal importance through CU traits is moderated by prior trauma exposure. This study, while exploratory, indicates that the pathophysiology associated with CU traits differs in youth as a function of prior trauma exposure. These data suggest that prior trauma exposure should be considered when evaluating potential interventions for youth with high CU traits.

Browsing while reading: effects of instructional design and learners' prior knowledge

Directory of Open Access Journals (Sweden)

Theimo Müller-Kalthoff

2006-12-01

Full Text Available One of the key reasons that multimedia, and particularly hypertext systems, are gaining in importance is that they inspire hopes of optimizing learners' processes of knowledge construction. The present study is concerned with the respective influence of individual learner variables (i.e. particularly domain-specific prior knowledge on the use of different design attributes. Thirty-six university students worked through a hierarchically structured two-part hypertext about the psychology of memory under two experimental browsing conditions (reduced versus free browsing. Results show that deeper-level comprehension (i.e. structural knowledge was predicted by the interaction of experimental condition and prior knowledge, but that simply retaining facts was not. Participants with low prior knowledge performed better on the comprehension test if they had worked on the version with reduced access. Moreover, the version with reduced access helped to reduce feelings of disorientation. The measure of disorientation also appeared to be closely linked with the individual's computer experience, self-concept of computer ability and subject-related interest. The main implications for educational practice relate to the design of an adaptive multimedia and hypertext learning system and the successful learning with it.

Factors affecting learning of vector math from computer-based practice: Feedback complexity and prior knowledge

Directory of Open Access Journals (Sweden)

Andrew F. Heckler

2016-06-01

Full Text Available In experiments including over 450 university-level students, we studied the effectiveness and time efficiency of several levels of feedback complexity in simple, computer-based training utilizing static question sequences. The learning domain was simple vector math, an essential skill in introductory physics. In a unique full factorial design, we studied the relative effects of “knowledge of correct response” feedback and “elaborated feedback” (i.e., a general explanation both separately and together. A number of other factors were analyzed, including training time, physics course grade, prior knowledge of vector math, and student beliefs about both their proficiency in and the importance of vector math. We hypothesize a simple model predicting how the effectiveness of feedback depends on prior knowledge, and the results confirm this knowledge-by-treatment interaction. Most notably, elaborated feedback is the most effective feedback, especially for students with low prior knowledge and low course grade. In contrast, knowledge of correct response feedback was less effective for low-performing students, and including both kinds of feedback did not significantly improve performance compared to elaborated feedback alone. Further, while elaborated feedback resulted in higher scores, the learning rate was at best only marginally higher because the training time was slightly longer. Training time data revealed that students spent significantly more time on the elaborated feedback after answering a training question incorrectly. Finally, we found that training improved student self-reported proficiency and that belief in the importance of the learned domain improved the effectiveness of training. Overall, we found that computer based training with static question sequences and immediate elaborated feedback in the form of simple and general explanations can be an effective way to improve student performance on a physics essential skill

Testability evaluation using prior information of multiple sources

Directory of Open Access Journals (Sweden)

Wang Chao

2014-08-01

Full Text Available Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR and fault isolation rate (FIR, which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testability demonstration test data (TDTD such as low evaluation confidence and inaccurate result, a testability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF, and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

Hanford low-level tank waste interim performance assessment

International Nuclear Information System (INIS)

Mann, F.M.

1997-01-01

The Hanford Low-Level Tank Waste Interim Performance Assessment examines the long-term environmental and human health effects associated with the disposal of the low-level fraction of the Hanford single and double-shell tank waste in the Hanford Site 200 East Area. This report was prepared as a good management practice to provide needed information about the relationship between the disposal system design and performance early in the disposal system project cycle. The calculations in this performance assessment show that the disposal of the low-level fraction can meet environmental and health performance objectives

Short Report Biochemical derangements prior to emergency ...

African Journals Online (AJOL)

MMJ VOL 29 (1): March 2017. Biochemical derangements prior to emergency laparotomy at QECH 55. Malawi Medical Journal 29 (1): March 2017 ... Venepuncture was performed preoperatively for urgent cases, defined as those requiring.

Interactive lesion segmentation with shape priors from offline and online learning.

Science.gov (United States)

Shepherd, Tony; Prince, Simon J D; Alexander, Daniel C

2012-09-01

In medical image segmentation, tumors and other lesions demand the highest levels of accuracy but still call for the highest levels of manual delineation. One factor holding back automatic segmentation is the exemption of pathological regions from shape modelling techniques that rely on high-level shape information not offered by lesions. This paper introduces two new statistical shape models (SSMs) that combine radial shape parameterization with machine learning techniques from the field of nonlinear time series analysis. We then develop two dynamic contour models (DCMs) using the new SSMs as shape priors for tumor and lesion segmentation. From training data, the SSMs learn the lower level shape information of boundary fluctuations, which we prove to be nevertheless highly discriminant. One of the new DCMs also uses online learning to refine the shape prior for the lesion of interest based on user interactions. Classification experiments reveal superior sensitivity and specificity of the new shape priors over those previously used to constrain DCMs. User trials with the new interactive algorithms show that the shape priors are directly responsible for improvements in accuracy and reductions in user demand.

Prior video game utilization is associated with improved performance on a robotic skills simulator.

Science.gov (United States)

Harbin, Andrew C; Nadhan, Kumar S; Mooney, James H; Yu, Daohai; Kaplan, Joshua; McGinley-Hence, Nora; Kim, Andrew; Gu, Yiming; Eun, Daniel D

2017-09-01

Laparoscopic surgery and robotic surgery, two forms of minimally invasive surgery (MIS), have recently experienced a large increase in utilization. Prior studies have shown that video game experience (VGE) may be associated with improved laparoscopic surgery skills; however, similar data supporting a link between VGE and proficiency on a robotic skills simulator (RSS) are lacking. The objective of our study is to determine whether volume or timing of VGE had any impact on RSS performance. Pre-clinical medical students completed a comprehensive questionnaire detailing previous VGE across several time periods. Seventy-five subjects were ultimately evaluated in 11 training exercises on the daVinci Si Skills Simulator. RSS skill was measured by overall score, time to completion, economy of motion, average instrument collision, and improvement in Ring Walk 3 score. Using the nonparametric tests and linear regression, these metrics were analyzed for systematic differences between non-users, light, and heavy video game users based on their volume of use in each of the following four time periods: past 3 months, past year, past 3 years, and high school. Univariate analyses revealed significant differences between heavy and non-users in all five performance metrics. These trends disappeared as the period of VGE went further back. Our study showed a positive association between video game experience and robotic skills simulator performance that is stronger for more recent periods of video game use. The findings may have important implications for the evolution of robotic surgery training.

Attenuation of muscle damage by preconditioning with muscle hyperthermia 1-day prior to eccentric exercise.

Science.gov (United States)

Nosaka, K; Muthalib, M; Lavender, A; Laursen, P B

2007-01-01

This study investigated the hypothesis that muscle damage would be attenuated in muscles subjected to passive hyperthermia 1 day prior to exercise. Fifteen male students performed 24 maximal eccentric actions of the elbow flexors with one arm; the opposite arm performed the same exercise 2-4 weeks later. The elbow flexors of one arm received a microwave diathermy treatment that increased muscle temperature to over 40 degrees C, 16-20 h prior to the exercise. The contralateral arm acted as an untreated control. Maximal voluntary isometric contraction strength (MVC), range of motion (ROM), upper arm circumference, muscle soreness, plasma creatine kinase activity and myoglobin concentration were measured 1 day prior to exercise, immediately before and after exercise, and daily for 4 days following exercise. Changes in the criterion measures were compared between conditions (treatment vs. control) using a two-way repeated measures ANOVA with a significance level of P < 0.05. All measures changed significantly following exercise, but the treatment arm showed a significantly faster recovery of MVC, a smaller change in ROM, and less muscle soreness compared with the control arm. However, the protective effect conferred by the diathermy treatment was significantly less effective compared with that seen in the second bout performed 4-6 weeks after the initial bout by a subgroup of the subjects (n = 11) using the control arm. These results suggest that passive hyperthermia treatment 1 day prior to eccentric exercise-induced muscle damage has a prophylactic effect, but the effect is not as strong as the repeated bout effect.

GENERAL ASPECTS REGARDING THE PRIOR DISCIPLINARY RESEARCH

Directory of Open Access Journals (Sweden)

ANDRA PURAN (DASCĂLU

2012-05-01

Full Text Available Disciplinary research is the first phase of the disciplinary action. According to art. 251 paragraph 1 of the Labour Code no disciplinary sanction may be ordered before performing the prior disciplinary research.These regulations provide an exception: the sanction of written warning. The current regulations in question, kept from the old regulation, provides a protection for employees against abuses made by employers, since sanctions are affecting the salary or the position held, or even the development of individual employment contract. Thus, prior research of the fact that is a misconduct, before a disciplinary sanction is applied, is an essential condition for the validity of the measure ordered. Through this study we try to highlight some general issues concerning the characteristics, processes and effects of prior disciplinary research.

Performance of the CMS High Level Trigger

CERN Document Server

Perrotta, Andrea

2015-01-01

The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved trac...

Admission Math Level and Student Performance

DEFF Research Database (Denmark)

la Cour, Lisbeth

2015-01-01

In this paper we analyze the study performance data for three cohorts of students for the course in Economics at the Business Diploma (herafter HD) study program at Copenhagen Business School. Out main findings are 1) that students with the lowest level of math from high school are performing worse...

Modeling and validating Bayesian accrual models on clinical data and simulations using adaptive priors.

Science.gov (United States)

Jiang, Yu; Simon, Steve; Mayo, Matthew S; Gajewski, Byron J

2015-02-20

Slow recruitment in clinical trials leads to increased costs and resource utilization, which includes both the clinic staff and patient volunteers. Careful planning and monitoring of the accrual process can prevent the unnecessary loss of these resources. We propose two hierarchical extensions to the existing Bayesian constant accrual model: the accelerated prior and the hedging prior. The new proposed priors are able to adaptively utilize the researcher's previous experience and current accrual data to produce the estimation of trial completion time. The performance of these models, including prediction precision, coverage probability, and correct decision-making ability, is evaluated using actual studies from our cancer center and simulation. The results showed that a constant accrual model with strongly informative priors is very accurate when accrual is on target or slightly off, producing smaller mean squared error, high percentage of coverage, and a high number of correct decisions as to whether or not continue the trial, but it is strongly biased when off target. Flat or weakly informative priors provide protection against an off target prior but are less efficient when the accrual is on target. The accelerated prior performs similar to a strong prior. The hedging prior performs much like the weak priors when the accrual is extremely off target but closer to the strong priors when the accrual is on target or only slightly off target. We suggest improvements in these models and propose new models for future research. Copyright © 2014 John Wiley & Sons, Ltd.

Synchrotron micro-diffraction analysis of the microstructure of cryogenically treated high performance tool steels prior to and after tempering

Energy Technology Data Exchange (ETDEWEB)

Xu, N.; Cavallaro, G.P. [Applied Centre for Structural and Synchrotron Studies, Mawson Lakes Blvd, University of South Australia, Mawson Lakes, South Australia 5095 (Australia); Gerson, A.R., E-mail: Andrea.Gerson@unisa.edu.au [Applied Centre for Structural and Synchrotron Studies, Mawson Lakes Blvd, University of South Australia, Mawson Lakes, South Australia 5095 (Australia)

2010-10-15

The phase transformation and strain changes within cryogenically (-196 deg. C) treated high performance tool steels (AISI H13) before and after tempering have been examined using both laboratory XRD and synchrotron micro-diffraction. The martensitic unit cell was found to have very low tetragonality as expected for low carbon steel. Tempering resulted in the diffusion of excess carbon out of the martensite phase and consequent unit cell shrinkage. In addition on tempering the martensite became more homogeneous as compared to the same samples prior to tempering. For cryogenically treated samples, the effect was most pronounced for the rapidly cooled sample which was the least homogenous sample prior to tempering but was the most homogenous sample after tempering. This suggests that the considerable degree of disorder resulting from rapid cryogenic cooling results in the beneficial release of micro-stresses on tempering thus possibly resulting in the improved wear resistance and durability observed for cryogenically treated tool steels.

Synchrotron micro-diffraction analysis of the microstructure of cryogenically treated high performance tool steels prior to and after tempering

International Nuclear Information System (INIS)

Xu, N.; Cavallaro, G.P.; Gerson, A.R.

2010-01-01

The phase transformation and strain changes within cryogenically (-196 deg. C) treated high performance tool steels (AISI H13) before and after tempering have been examined using both laboratory XRD and synchrotron micro-diffraction. The martensitic unit cell was found to have very low tetragonality as expected for low carbon steel. Tempering resulted in the diffusion of excess carbon out of the martensite phase and consequent unit cell shrinkage. In addition on tempering the martensite became more homogeneous as compared to the same samples prior to tempering. For cryogenically treated samples, the effect was most pronounced for the rapidly cooled sample which was the least homogenous sample prior to tempering but was the most homogenous sample after tempering. This suggests that the considerable degree of disorder resulting from rapid cryogenic cooling results in the beneficial release of micro-stresses on tempering thus possibly resulting in the improved wear resistance and durability observed for cryogenically treated tool steels.

Generalized multiple kernel learning with data-dependent priors.

Science.gov (United States)

Mao, Qi; Tsang, Ivor W; Gao, Shenghua; Wang, Li

2015-06-01

Multiple kernel learning (MKL) and classifier ensemble are two mainstream methods for solving learning problems in which some sets of features/views are more informative than others, or the features/views within a given set are inconsistent. In this paper, we first present a novel probabilistic interpretation of MKL such that maximum entropy discrimination with a noninformative prior over multiple views is equivalent to the formulation of MKL. Instead of using the noninformative prior, we introduce a novel data-dependent prior based on an ensemble of kernel predictors, which enhances the prediction performance of MKL by leveraging the merits of the classifier ensemble. With the proposed probabilistic framework of MKL, we propose a hierarchical Bayesian model to learn the proposed data-dependent prior and classification model simultaneously. The resultant problem is convex and other information (e.g., instances with either missing views or missing labels) can be seamlessly incorporated into the data-dependent priors. Furthermore, a variety of existing MKL models can be recovered under the proposed MKL framework and can be readily extended to incorporate these priors. Extensive experiments demonstrate the benefits of our proposed framework in supervised and semisupervised settings, as well as in tasks with partial correspondence among multiple views.

Can natural selection encode Bayesian priors?

Science.gov (United States)

Ramírez, Juan Camilo; Marshall, James A R

2017-08-07

The evolutionary success of many organisms depends on their ability to make decisions based on estimates of the state of their environment (e.g., predation risk) from uncertain information. These decision problems have optimal solutions and individuals in nature are expected to evolve the behavioural mechanisms to make decisions as if using the optimal solutions. Bayesian inference is the optimal method to produce estimates from uncertain data, thus natural selection is expected to favour individuals with the behavioural mechanisms to make decisions as if they were computing Bayesian estimates in typically-experienced environments, although this does not necessarily imply that favoured decision-makers do perform Bayesian computations exactly. Each individual should evolve to behave as if updating a prior estimate of the unknown environment variable to a posterior estimate as it collects evidence. The prior estimate represents the decision-maker's default belief regarding the environment variable, i.e., the individual's default 'worldview' of the environment. This default belief has been hypothesised to be shaped by natural selection and represent the environment experienced by the individual's ancestors. We present an evolutionary model to explore how accurately Bayesian prior estimates can be encoded genetically and shaped by natural selection when decision-makers learn from uncertain information. The model simulates the evolution of a population of individuals that are required to estimate the probability of an event. Every individual has a prior estimate of this probability and collects noisy cues from the environment in order to update its prior belief to a Bayesian posterior estimate with the evidence gained. The prior is inherited and passed on to offspring. Fitness increases with the accuracy of the posterior estimates produced. Simulations show that prior estimates become accurate over evolutionary time. In addition to these 'Bayesian' individuals, we also

45 CFR 305.40 - Penalty performance measures and levels.

Science.gov (United States)

2010-10-01

... HUMAN SERVICES PROGRAM PERFORMANCE MEASURES, STANDARDS, FINANCIAL INCENTIVES, AND PENALTIES § 305.40 Penalty performance measures and levels. (a) There are three performance measures for which States must... 45 Public Welfare 2 2010-10-01 2010-10-01 false Penalty performance measures and levels. 305.40...

Constrained noninformative priors

International Nuclear Information System (INIS)

Atwood, C.L.

1994-10-01

The Jeffreys noninformative prior distribution for a single unknown parameter is the distribution corresponding to a uniform distribution in the transformed model where the unknown parameter is approximately a location parameter. To obtain a prior distribution with a specified mean but with diffusion reflecting great uncertainty, a natural generalization of the noninformative prior is the distribution corresponding to the constrained maximum entropy distribution in the transformed model. Examples are given

A three-level framework for performance-based railway timetabling

DEFF Research Database (Denmark)

Goverde, Rob M P; Bešinović, Nikola; Binder, Anne

2016-01-01

. This paper presents a performance-based railway timetabling framework integrating timetable construction and evaluation on three levels: microscopic, macroscopic, and a corridor fine-tuning level, where each performance indicator is optimized or evaluated at the appropriate level. A modular implementation...

Performance assessment strategy for low-level waste disposal sites

International Nuclear Information System (INIS)

Starmer, R.J.; Deering, L.G.; Weber, M.F.

1988-01-01

This paper describes US Nuclear Regulatory Commission (NRC) staff views on predicting the performance of low-level radioactive waste disposal facilities. Under the Atomic Energy Act, as amended, and the Low Level Radioactive Waste Policy Act, as amended, the NRC and Agreement States license land disposal of low-level radioactive waste (LLW) using the requirements in 10 CFR Part 61 or comparable state requirements. The purpose of this paper is to briefly describe regulatory requirements for performance assessment in low-level waste licensing, a strategy for performance assessments to support license applications, and NRC staff licensing evaluation of performance assessments. NRC's current activities in developing a performance assessment methodology will provide an overall systems modeling approach for assessing the performance of LLW disposal facilities. NRC staff will use the methodology to evaluate performance assessments conducted by applicants for LLW disposal facilities. The methodology will be made available to states and other interested parties

Form of prior for constrained thermodynamic processes with uncertainty

Science.gov (United States)

Aneja, Preety; Johal, Ramandeep S.

2015-05-01

We consider the quasi-static thermodynamic processes with constraints, but with additional uncertainty about the control parameters. Motivated by inductive reasoning, we assign prior distribution that provides a rational guess about likely values of the uncertain parameters. The priors are derived explicitly for both the entropy-conserving and the energy-conserving processes. The proposed form is useful when the constraint equation cannot be treated analytically. The inference is performed using spin-1/2 systems as models for heat reservoirs. Analytical results are derived in the high-temperatures limit. An agreement beyond linear response is found between the estimates of thermal quantities and their optimal values obtained from extremum principles. We also seek an intuitive interpretation for the prior and the estimated value of temperature obtained therefrom. We find that the prior over temperature becomes uniform over the quantity kept conserved in the process.

Age-related influences of prior sleep on brain activation during verbal encoding

Directory of Open Access Journals (Sweden)

Michelle B Jonelis

2012-04-01

Full Text Available Disrupted sleep is more common in older adults (OA than younger adults (YA, often co-morbid with other conditions. How these sleep disturbances affect cognitive performance is an area of active study. We examined whether brain activation during verbal encoding correlates with sleep quantity and quality the night before testing in a group of healthy OA and YA. Twenty-seven OA (ages 59-82 and twenty-seven YA (ages 19-36 underwent one night of standard polysomnography. Twelve hours post-awakening, subjects performed a verbal encoding task while undergoing functional MRI. Analyses examined the group (OA vs. YA by prior sleep quantity (Total Sleep Time (TST or quality (Sleep Efficiency (SE interaction on cerebral activation, controlling for performance. Longer TST promoted higher levels of activation in the bilateral anterior parahippocampi in OA and lower activation levels in the left anterior parahippocampus in YA. Greater SE promoted higher activation levels in the left posterior parahippocampus and right inferior frontal gyrus in YA, but not in OA. The roles of these brain regions in verbal encoding suggest, in OA, longer sleep duration may facilitate functional compensation during cognitive challenges. By contrast, in YA, shorter sleep duration may necessitate functional compensation to maintain cognitive performance, similar to what is seen following acute sleep deprivation. Additionally, in YA, better sleep quality may improve semantic retrieval processes, thereby aiding encoding.

Level-1 $\\tau$ trigger performance in 2017 data

CERN Document Server

CMS Collaboration

2018-01-01

In 2017, the LHC achieved an instantaneous luminosity of 2.06x10$^{34}$cm$^{-2}$s$^{-1}$, and a peak average pile-up of more than 50. This document describes the performance of the CMS Level-1 calorimeter trigger for $\\tau$ leptons using 40.9 fb$^{-1}$ of 2017 data. Details of the Level-1 trigger algorithms can be found in CMS-DP-2015-009. The previous Level-1 $\\tau$ performance report can be found in CMS-DP-2017-022.

Cost-optimal levels for energy performance requirements

DEFF Research Database (Denmark)

Thomsen, Kirsten Engelund; Aggerholm, Søren; Kluttig-Erhorn, Heike

2011-01-01

The CA conducted a study on experiences and challenges for setting cost optimal levels for energy performance requirements. The results were used as input by the EU Commission in their work of establishing the Regulation on a comparative methodology framework for calculating cost optimal levels...... of minimum energy performance requirements. In addition to the summary report released in August 2011, the full detailed report on this study is now also made available, just as the EC is about to publish its proposed Regulation for MS to apply in their process to update national building requirements....

Contribution of Prior Semantic Knowledge to New Episodic Learning in Amnesia

Science.gov (United States)

Kan, Irene P.; Alexander, Michael P.; Verfaellie, Mieke

2009-01-01

We evaluated whether prior semantic knowledge would enhance episodic learning in amnesia. Subjects studied prices that are either congruent or incongruent with prior price knowledge for grocery and household items and then performed a forced-choice recognition test for the studied prices. Consistent with a previous report, healthy controls'…

Bayesian nonparametric system reliability using sets of priors

NARCIS (Netherlands)

Walter, G.M.; Aslett, L.J.M.; Coolen, F.P.A.

2016-01-01

An imprecise Bayesian nonparametric approach to system reliability with multiple types of components is developed. This allows modelling partial or imperfect prior knowledge on component failure distributions in a flexible way through bounds on the functioning probability. Given component level test

PET reconstruction via nonlocal means induced prior.

Science.gov (United States)

Hou, Qingfeng; Huang, Jing; Bian, Zhaoying; Chen, Wufan; Ma, Jianhua

2015-01-01

The traditional Bayesian priors for maximum a posteriori (MAP) reconstruction methods usually incorporate local neighborhood interactions that penalize large deviations in parameter estimates for adjacent pixels; therefore, only local pixel differences are utilized. This limits their abilities of penalizing the image roughness. To achieve high-quality PET image reconstruction, this study investigates a MAP reconstruction strategy by incorporating a nonlocal means induced (NLMi) prior (NLMi-MAP) which enables utilizing global similarity information of image. The present NLMi prior approximates the derivative of Gibbs energy function by an NLM filtering process. Specially, the NLMi prior is obtained by subtracting the current image estimation from its NLM filtered version and feeding the residual error back to the reconstruction filter to yield the new image estimation. We tested the present NLMi-MAP method with simulated and real PET datasets. Comparison studies with conventional filtered backprojection (FBP) and a few iterative reconstruction methods clearly demonstrate that the present NLMi-MAP method performs better in lowering noise, preserving image edge and in higher signal to noise ratio (SNR). Extensive experimental results show that the NLMi-MAP method outperforms the existing methods in terms of cross profile, noise reduction, SNR, root mean square error (RMSE) and correlation coefficient (CORR).

Effects of obligatory training and prior training experience on attitudes towards performing basic life support: a questionnaire survey.

Science.gov (United States)

Matsubara, Hiroki; Enami, Miki; Hirose, Keiko; Kamikura, Takahisa; Nishi, Taiki; Takei, Yutaka; Inaba, Hideo

2015-04-01

To determine the effect of Japanese obligatory basic life support training for new driver's license applicants on their willingness to carry out basic life support. We distributed a questionnaire to 9,807 participants of basic life support courses in authorized driving schools from May 2007 to April 2008 after the release of the 2006 Japanese guidelines. The questionnaire explored the participants' willingness to perform basic life support in four hypothetical scenarios: cardiopulmonary resuscitation on one's own initiative; compression-only cardiopulmonary resuscitation following telephone cardiopulmonary resuscitation; early emergency call; and use of an automated external defibrillator. The questionnaire was given at the beginning of the basic life support course in the first 6-month term and at the end in the second 6-month term. The 9,011 fully completed answer sheets were analyzed. The training significantly increased the proportion of respondents willing to use an automated external defibrillator and to perform cardiopulmonary resuscitation on their own initiative in those with and without prior basic life support training experience. It significantly increased the proportion of respondents willing to carry out favorable actions in all four scenarios. In multiple logistic regression analysis, basic life support training and prior training experiences within 3 years were associated with the attitude. The analysis of reasons for unwillingness suggested that the training reduced the lack of confidence in their skill but did not attenuate the lack of confidence in detection of arrest or clinical judgment to initiate a basic life support action. Obligatory basic life support training should be carried out periodically and modified to ensure that participants gain confidence in judging and detecting cardiac arrest.

Comparison of energy performance requirements levels

DEFF Research Database (Denmark)

Spiekman, Marleen; Thomsen, Kirsten Engelund; Rose, Jørgen

This summary report provides a synthesis of the work within the EU SAVE project ASIEPI on developing a method to compare the energy performance (EP) requirement levels among the countries of Europe. Comparing EP requirement levels constitutes a major challenge. From the comparison of for instance...... the present Dutch requirement level (EPC) of 0,8 with the present Flemish level of E80, it can easily be seen that direct comparison is not possible. The conclusions and recommendations of the study are presented in part A. These constitute the most important result of the project. Part B gives an overview...... of all other project material related to that topic, which allows to easily identify the most pertinent information. Part C lists the project partners and sponsors....

Treatment of uncertainty in low-level waste performance assessment

International Nuclear Information System (INIS)

Kozak, M.W.; Olague, N.E.; Gallegos, D.P.; Rao, R.R.

1991-01-01

Uncertainties arise from a number of different sources in low-level waste performance assessment. In this paper the types of uncertainty are reviewed, and existing methods for quantifying and reducing each type of uncertainty are discussed. These approaches are examined in the context of the current low-level radioactive waste regulatory performance objectives, which are deterministic. The types of uncertainty discussed in this paper are model uncertainty, uncertainty about future conditions, and parameter uncertainty. The advantages and disadvantages of available methods for addressing uncertainty in low-level waste performance assessment are presented. 25 refs

Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging.

Science.gov (United States)

Zhang, Shuanghui; Liu, Yongxiang; Li, Xiang; Bi, Guoan

2016-04-28

This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR) algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP) estimation and the maximum likelihood estimation (MLE) are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT) and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging

Directory of Open Access Journals (Sweden)

Shuanghui Zhang

2016-04-01

Full Text Available This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP estimation and the maximum likelihood estimation (MLE are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

Performance of an Additional Task During Level 2 Automated Driving: An On-Road Study Comparing Drivers With and Without Experience With Partial Automation.

Science.gov (United States)

Solís-Marcos, Ignacio; Ahlström, Christer; Kircher, Katja

2018-05-01

To investigate the influence of prior experience with Level 2 automation on additional task performance during manual and Level 2 partially automated driving. Level 2 automation is now on the market, but its effects on driver behavior remain unclear. Based on previous studies, we could expect an increase in drivers' engagement in secondary tasks during Level 2 automated driving, but it is yet unknown how drivers will integrate all the ongoing demands in such situations. Twenty-one drivers (12 without, 9 with Level 2 automation experience) drove on a highway manually and with Level 2 automation (exemplified by Volvo Pilot Assist generation 2; PA2) while performing an additional task. In half of the conditions, the task could be interrupted (self-paced), and in the other half, it could not (system-paced). Drivers' visual attention, additional task performance, and other compensatory strategies were analyzed. Driving with PA2 led to decreased scores in the additional task and more visual attention to the dashboard. In the self-paced condition, all drivers looked more to the task and perceived a lower mental demand. The drivers experienced with PA2 used the system and the task more than the novice group and performed more overtakings. The additional task interfered more with Level 2 automation than with manual driving. The drivers, particularly the automation novice drivers, used some compensatory strategies. Automation designers need to consider these potential effects in the development of future automated systems.

Nuisance levels of noise effects radiologists' performance

Science.gov (United States)

McEntee, Mark F.; Coffey, Amina; Ryan, John; O'Beirne, Aaron; Toomey, Rachel; Evanoff, Micheal; Manning, David; Brennan, Patrick C.

2010-02-01

This study aimed to measure the sound levels in Irish x-ray departments. The study then established whether these levels of noise have an impact on radiologists performance Noise levels were recorded 10 times within each of 14 environments in 4 hospitals, 11 of which were locations where radiologic images are judged. Thirty chest images were then presented to 26 senior radiologists, who were asked to detect up to three nodular lesions within 30 posteroanterior chest x-ray images in the absence and presence of noise at amplitude demonstrated in the clinical environment. The results demonstrated that noise amplitudes rarely exceeded that encountered with normal conversation with the maximum mean value for an image-viewing environment being 56.1 dB. This level of noise had no impact on the ability of radiologists to identify chest lesions with figure of merits of 0.68, 0.69, and 0.68 with noise and 0.65, 0.68, and 0.67 without noise for chest radiologists, non-chest radiologists, and all radiologists, respectively. the difference in their performance using the DBM MRMC method was significantly better with noise than in the absence of noise at the 90% confidence interval (p=0.077). Further studies are required to establish whether other aspects of diagnosis are impaired such as recall and attention and the effects of more unexpected noise on performance.

Self-prior strategy for organ reconstruction in fluorescence molecular tomography.

Science.gov (United States)

Zhou, Yuan; Chen, Maomao; Su, Han; Luo, Jianwen

2017-10-01

The purpose of this study is to propose a strategy for organ reconstruction in fluorescence molecular tomography (FMT) without prior information from other imaging modalities, and to overcome the high cost and ionizing radiation caused by the traditional structural prior strategy. The proposed strategy is designed as an iterative architecture to solve the inverse problem of FMT. In each iteration, a short time Fourier transform (STFT) based algorithm is used to extract the self-prior information in the space-frequency energy spectrum with the assumption that the regions with higher fluorescence concentration have larger energy intensity, then the cost function of the inverse problem is modified by the self-prior information, and lastly an iterative Laplacian regularization algorithm is conducted to solve the updated inverse problem and obtains the reconstruction results. Simulations and in vivo experiments on liver reconstruction are carried out to test the performance of the self-prior strategy on organ reconstruction. The organ reconstruction results obtained by the proposed self-prior strategy are closer to the ground truth than those obtained by the iterative Tikhonov regularization (ITKR) method (traditional non-prior strategy). Significant improvements are shown in the evaluation indexes of relative locational error (RLE), relative error (RE) and contrast-to-noise ratio (CNR). The self-prior strategy improves the organ reconstruction results compared with the non-prior strategy and also overcomes the shortcomings of the traditional structural prior strategy. Various applications such as metabolic imaging and pharmacokinetic study can be aided by this strategy.

SUSPENSION OF THE PRIOR DISCIPLINARY INVESTIGATION ACCORDING TO LABOR LAW

Directory of Open Access Journals (Sweden)

Nicolae, GRADINARU

2014-11-01

Full Text Available In order to conduct the prior disciplinary investigation, the employee shall be convoked in writing by the person authorized by the employer to carry out the research, specifying the subject, date, time and place of the meeting. For this purpose the employer shall appoint a committee charged with conducting the prior disciplinary investigation. Prior disciplinary research cannot be done without the possibility of the accused person to defend himself. It would be an abuse of the employer to violate these provisions. Since the employee is entitled to formulate and sustain defence in proving innocence or lesser degree of guilt than imputed, it needs between the moment were disclosed to the employee and the one of performing the prior disciplinary investigation to be a reasonable term for the employee to be able to prepare a defence in this regard. The employee's failure to present at the convocation, without an objective reason entitles the employer to dispose the sanctioning without making the prior disciplinary investigation. The objective reason which makes the employee, that is subject to prior disciplinary investigation, unable to present to the preliminary disciplinary investigation, should be at the time of the investigation in question.

On the performance of 1-level LDPC lattices

OpenAIRE

Sadeghi, Mohammad-Reza; Sakzad, Amin

2013-01-01

The low-density parity-check (LDPC) lattices perform very well in high dimensions under generalized min-sum iterative decoding algorithm. In this work we focus on 1-level LDPC lattices. We show that these lattices are the same as lattices constructed based on Construction A and low-density lattice-code (LDLC) lattices. In spite of having slightly lower coding gain, 1-level regular LDPC lattices have remarkable performances. The lower complexity nature of the decoding algorithm for these type ...

On selecting a prior for the precision parameter of Dirichlet process mixture models

Science.gov (United States)

Dorazio, R.M.

2009-01-01

In hierarchical mixture models the Dirichlet process is used to specify latent patterns of heterogeneity, particularly when the distribution of latent parameters is thought to be clustered (multimodal). The parameters of a Dirichlet process include a precision parameter ?? and a base probability measure G0. In problems where ?? is unknown and must be estimated, inferences about the level of clustering can be sensitive to the choice of prior assumed for ??. In this paper an approach is developed for computing a prior for the precision parameter ?? that can be used in the presence or absence of prior information about the level of clustering. This approach is illustrated in an analysis of counts of stream fishes. The results of this fully Bayesian analysis are compared with an empirical Bayes analysis of the same data and with a Bayesian analysis based on an alternative commonly used prior.

The Effects of Supplementation with a Vitamin and Mineral Complex with Guaraná Prior to Fasted Exercise on Affect, Exertion, Cognitive Performance, and Substrate Metabolism: A Randomized Controlled Trial

Directory of Open Access Journals (Sweden)

Rachel C. Veasey

2015-07-01

Full Text Available Exercise undertaken in a fasted state can lead to higher post-exercise mental fatigue. The administration of a vitamin and mineral complex with guaraná (MVM + G has been shown to attenuate mental fatigue and improve performance during cognitively demanding tasks. This placebo-controlled, double-blind, randomized, balanced cross-over study examined the effect of MVM + G consumed prior to morning exercise on cognitive performance, affect, exertion, and substrate metabolism. Forty active males (age 21.4 ± 3.0 year; body mass index (BMI 24.0 ± 2.4 kg/m2; maximal oxygen consumption (V̇O2max 57.6 ± 7.3 mL/min/kg completed two main trials, consuming either MVM + G or placebo prior to a 30-min run at 60% V̇O2max. Supplementation prior to exercise led to a small but significant reduction in Rating of Perceived Exertion (RPE during exercise compared to the placebo. The MVM + G combination also led to significantly increased accuracy of numeric working memory and increased speed of picture recognition, compared to the placebo. There were no significant effects of supplementation on any other cognitive or mood measures or on substrate metabolism during exercise. These findings demonstrate that consuming a vitamin and mineral complex containing guaraná, prior to exercise, can positively impact subsequent memory performance and reduce perceived exertion during a moderate-intensity run in active males.

Neutrino mass priors for cosmology from random matrices

Science.gov (United States)

Long, Andrew J.; Raveri, Marco; Hu, Wayne; Dodelson, Scott

2018-02-01

Cosmological measurements of structure are placing increasingly strong constraints on the sum of the neutrino masses, Σ mν, through Bayesian inference. Because these constraints depend on the choice for the prior probability π (Σ mν), we argue that this prior should be motivated by fundamental physical principles rather than the ad hoc choices that are common in the literature. The first step in this direction is to specify the prior directly at the level of the neutrino mass matrix Mν, since this is the parameter appearing in the Lagrangian of the particle physics theory. Thus by specifying a probability distribution over Mν, and by including the known squared mass splittings, we predict a theoretical probability distribution over Σ mν that we interpret as a Bayesian prior probability π (Σ mν). Assuming a basis-invariant probability distribution on Mν, also known as the anarchy hypothesis, we find that π (Σ mν) peaks close to the smallest Σ mν allowed by the measured mass splittings, roughly 0.06 eV (0.1 eV) for normal (inverted) ordering, due to the phenomenon of eigenvalue repulsion in random matrices. We consider three models for neutrino mass generation: Dirac, Majorana, and Majorana via the seesaw mechanism; differences in the predicted priors π (Σ mν) allow for the possibility of having indications about the physical origin of neutrino masses once sufficient experimental sensitivity is achieved. We present fitting functions for π (Σ mν), which provide a simple means for applying these priors to cosmological constraints on the neutrino masses or marginalizing over their impact on other cosmological parameters.

IMMEDIATE RECIPROCAL CHANGES AT ADJACENT LEVEL FOLLOWING SINGLE-LEVEL ALIF

OpenAIRE

Uribe, Enrique Vargas; Amaral, Rodrigo; Marchi, Luis; Jensen, Rubens; Oliveira, Leonardo; Fortti, Fernanda; Coutinho, Etevaldo; Pimenta, Luiz

2015-01-01

Objective : To assess the segmental sagittal parameters and the adjacent mobile segment after interbody fusion by anterior approach in single-level L5-S1. Methods : Retrospective study. Inclusion: Interbody fusion by anterior approach (10°/15° angle), due to DDD, low-grade spondylolisthesis and/or stenosis without prior lumbar fusion. Thirty-five cases were included (25 women; mean age 47±15 years). Analysis of lumbar radiographs were performed preoperatively and 3 months after surgery. The ...

Performing Inferential Statistics Prior to Data Collection

Science.gov (United States)

Trafimow, David; MacDonald, Justin A.

2017-01-01

Typically, in education and psychology research, the investigator collects data and subsequently performs descriptive and inferential statistics. For example, a researcher might compute group means and use the null hypothesis significance testing procedure to draw conclusions about the populations from which the groups were drawn. We propose an…

Testing animal-assisted cleaning prior to transplantation in coral reef restoration.

Science.gov (United States)

Frias-Torres, Sarah; van de Geer, Casper

2015-01-01

Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is necessary prior to transplantation, and this cleaning constitutes a significant time investment in a restoration project. We tested a novel biomimicry technique of animal-assisted cleaning on nursery corals prior to transplantation at a coral reef restoration site in Seychelles, Indian Ocean. To determine whether animal-assisted cleaning was possible, preliminary visual underwater surveys were performed to quantify the fish community at the study site. Then, cleaning stations consisting of nursery ropes carrying corals and biofouling organisms, set at 0.3 m, 2 m, 4 m, 6 m and 8 m from the seabed, were placed at both the transplantation (treatment) site and the nursery (control) site. Remote GoPro video cameras recorded fish feeding at the nursery ropes without human disturbance. A reef fish assemblage of 32 species from 4 trophic levels (18.8% herbivores, 18.8% omnivores, 59.3% secondary consumers and 3.1% carnivores) consumed 95% of the barnacles on the coral nursery ropes placed 0.3 m above the seabed. Using this cleaning station, we reduced coral dislodgement from 16% to zero. This cleaning station technique could be included as a step prior to coral transplantation worldwide on the basis of location-specific fish assemblages and during the early nursery phase of sexually produced juvenile corals.

Testing animal-assisted cleaning prior to transplantation in coral reef restoration

Directory of Open Access Journals (Sweden)

Sarah Frias-Torres

2015-09-01

Full Text Available Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is necessary prior to transplantation, and this cleaning constitutes a significant time investment in a restoration project. We tested a novel biomimicry technique of animal-assisted cleaning on nursery corals prior to transplantation at a coral reef restoration site in Seychelles, Indian Ocean. To determine whether animal-assisted cleaning was possible, preliminary visual underwater surveys were performed to quantify the fish community at the study site. Then, cleaning stations consisting of nursery ropes carrying corals and biofouling organisms, set at 0.3 m, 2 m, 4 m, 6 m and 8 m from the seabed, were placed at both the transplantation (treatment site and the nursery (control site. Remote GoPro video cameras recorded fish feeding at the nursery ropes without human disturbance. A reef fish assemblage of 32 species from 4 trophic levels (18.8% herbivores, 18.8% omnivores, 59.3% secondary consumers and 3.1% carnivores consumed 95% of the barnacles on the coral nursery ropes placed 0.3 m above the seabed. Using this cleaning station, we reduced coral dislodgement from 16% to zero. This cleaning station technique could be included as a step prior to coral transplantation worldwide on the basis of location-specific fish assemblages and during the early nursery phase of sexually produced juvenile corals.

Testing animal-assisted cleaning prior to transplantation in coral reef restoration

Science.gov (United States)

van de Geer, Casper

2015-01-01

Rearing coral fragments in nurseries and subsequent transplantation onto a degraded reef is a common approach for coral reef restoration. However, if barnacles and other biofouling organisms are not removed prior to transplantation, fish will dislodge newly cemented corals when feeding on biofouling organisms. This behavior can lead to an increase in diver time due to the need to reattach the corals. Thus, cleaning nurseries to remove biofouling organisms such as algae and invertebrates is necessary prior to transplantation, and this cleaning constitutes a significant time investment in a restoration project. We tested a novel biomimicry technique of animal-assisted cleaning on nursery corals prior to transplantation at a coral reef restoration site in Seychelles, Indian Ocean. To determine whether animal-assisted cleaning was possible, preliminary visual underwater surveys were performed to quantify the fish community at the study site. Then, cleaning stations consisting of nursery ropes carrying corals and biofouling organisms, set at 0.3 m, 2 m, 4 m, 6 m and 8 m from the seabed, were placed at both the transplantation (treatment) site and the nursery (control) site. Remote GoPro video cameras recorded fish feeding at the nursery ropes without human disturbance. A reef fish assemblage of 32 species from 4 trophic levels (18.8% herbivores, 18.8% omnivores, 59.3% secondary consumers and 3.1% carnivores) consumed 95% of the barnacles on the coral nursery ropes placed 0.3 m above the seabed. Using this cleaning station, we reduced coral dislodgement from 16% to zero. This cleaning station technique could be included as a step prior to coral transplantation worldwide on the basis of location-specific fish assemblages and during the early nursery phase of sexually produced juvenile corals. PMID:26468440

The effects of prior calcium channel blocker therapy on creatine kinase-MB levels after percutaneous coronary interventions

Directory of Open Access Journals (Sweden)

Oyku Gulmez

2008-12-01

Full Text Available Oyku Gulmez, Ilyas Atar, Bülent Ozin, Mehmet Emin Korkmaz, Aslı Atar, Alp Aydinalp, Aylin Yildirir, Haldun MuderrisogluBaskent University Faculty of Medicine, Department of Cardiology, Ankara, TurkeyBackground: Use of intracoronary calcium channel blockers (CCBs during percutaneous coronary intervention (PCI has been shown to have favorable effects on coronary blood flow. We aimed to investigate the effects of CCBs administrated perorally on creatine kinase-MB (CK-MB levels in patients undergoing elective PCI.Methods: A total of 570 patients who underwent PCI were evaluated for CK-MB elevation. Patients who were on CCB therapy when admitted to the hospital constituted the CCB group. No CCBs were given to the rest of the patients during the periprocedural period and these patients served as the control group. Blood samples for CK-MB were obtained before and at 6 h, 24 h, and 36 h after the procedure.Results: 217 patients were in the CCB group (mean age 60.2 ± 9.3 years, 162 males, and 353 were in the control group (mean age 60.0 ± 10.1 years, 262 males. CK-MB levels increased above the normal values in 41 patients (18.9% of the CCBs group and in 97 patients (27.5% of the control group (p = 0.02. Median CK-MB levels were significantly higher in the control group for all studied hours (for all p < 0.05.Conclusions: Prior oral CCB therapy may have favorable effects in preventing myocyte necrosis after elective PCI.Keywords: calcium channel blockers, myonecrosis, percutaneous coronary interventions

Statistical Learning Is Not Affected by a Prior Bout of Physical Exercise

Science.gov (United States)

Stevens, David J.; Arciuli, Joanne; Anderson, David I.

2016-01-01

This study examined the effect of a prior bout of exercise on implicit cognition. Specifically, we examined whether a prior bout of moderate intensity exercise affected performance on a statistical learning task in healthy adults. A total of 42 participants were allocated to one of three conditions--a control group, a group that exercised for…

How does firm performance influence market orientation?

DEFF Research Database (Denmark)

Sørensen, Hans Eibe; Stieglitz, Nils

This paper contributes by investigating how firm performance influences its market orientation. We draw on the aspiration-level model from the behavioral theory of the firm to develop testable propositions that substantiate and extend prior market orientation research. Specifically, we address how...... performance influences firms' market-oriented search behavior (responsive or proactive) and the allocation of attention (customer and competitor orientation) as well as the formation of aspiration levels. Research and managerial implications are discussed....

A Simulation of Pell Grant Awards and Costs Using Prior-Prior Year Financial Data

Science.gov (United States)

Kelchen, Robert; Jones, Gigi

2015-01-01

We examine the likely implications of switching from a prior year (PY) financial aid system, the current practice in which students file the Free Application for Federal Student Aid (FAFSA) using income data from the previous tax year, to prior-prior year (PPY), in which data from two years before enrollment is used. While PPY allows students to…

Active Prior Tactile Knowledge Transfer for Learning Tactual Properties of New Objects

Directory of Open Access Journals (Sweden)

Di Feng

2018-02-01

Full Text Available Reusing the tactile knowledge of some previously-explored objects (prior objects helps us to easily recognize the tactual properties of new objects. In this paper, we enable a robotic arm equipped with multi-modal artificial skin, like humans, to actively transfer the prior tactile exploratory action experiences when it learns the detailed physical properties of new objects. These experiences, or prior tactile knowledge, are built by the feature observations that the robot perceives from multiple sensory modalities, when it applies the pressing, sliding, and static contact movements on objects with different action parameters. We call our method Active Prior Tactile Knowledge Transfer (APTKT, and systematically evaluated its performance by several experiments. Results show that the robot improved the discrimination accuracy by around 10 % when it used only one training sample with the feature observations of prior objects. By further incorporating the predictions from the observation models of prior objects as auxiliary features, our method improved the discrimination accuracy by over 20 % . The results also show that the proposed method is robust against transferring irrelevant prior tactile knowledge (negative knowledge transfer.

Impact of Cognitive Abilities and Prior Knowledge on Complex Problem Solving Performance – Empirical Results and a Plea for Ecologically Valid Microworlds

Directory of Open Access Journals (Sweden)

Heinz-Martin Süß

2018-05-01

Full Text Available The original aim of complex problem solving (CPS research was to bring the cognitive demands of complex real-life problems into the lab in order to investigate problem solving behavior and performance under controlled conditions. Up until now, the validity of psychometric intelligence constructs has been scrutinized with regard to its importance for CPS performance. At the same time, different CPS measurement approaches competing for the title of the best way to assess CPS have been developed. In the first part of the paper, we investigate the predictability of CPS performance on the basis of the Berlin Intelligence Structure Model and Cattell’s investment theory as well as an elaborated knowledge taxonomy. In the first study, 137 students managed a simulated shirt factory (Tailorshop; i.e., a complex real life-oriented system twice, while in the second study, 152 students completed a forestry scenario (FSYS; i.e., a complex artificial world system. The results indicate that reasoning – specifically numerical reasoning (Studies 1 and 2 and figural reasoning (Study 2 – are the only relevant predictors among the intelligence constructs. We discuss the results with reference to the Brunswik symmetry principle. Path models suggest that reasoning and prior knowledge influence problem solving performance in the Tailorshop scenario mainly indirectly. In addition, different types of system-specific knowledge independently contribute to predicting CPS performance. The results of Study 2 indicate that working memory capacity, assessed as an additional predictor, has no incremental validity beyond reasoning. We conclude that (1 cognitive abilities and prior knowledge are substantial predictors of CPS performance, and (2 in contrast to former and recent interpretations, there is insufficient evidence to consider CPS a unique ability construct. In the second part of the paper, we discuss our results in light of recent CPS research, which predominantly

Impact of Cognitive Abilities and Prior Knowledge on Complex Problem Solving Performance – Empirical Results and a Plea for Ecologically Valid Microworlds

Science.gov (United States)

Süß, Heinz-Martin; Kretzschmar, André

2018-01-01

The original aim of complex problem solving (CPS) research was to bring the cognitive demands of complex real-life problems into the lab in order to investigate problem solving behavior and performance under controlled conditions. Up until now, the validity of psychometric intelligence constructs has been scrutinized with regard to its importance for CPS performance. At the same time, different CPS measurement approaches competing for the title of the best way to assess CPS have been developed. In the first part of the paper, we investigate the predictability of CPS performance on the basis of the Berlin Intelligence Structure Model and Cattell’s investment theory as well as an elaborated knowledge taxonomy. In the first study, 137 students managed a simulated shirt factory (Tailorshop; i.e., a complex real life-oriented system) twice, while in the second study, 152 students completed a forestry scenario (FSYS; i.e., a complex artificial world system). The results indicate that reasoning – specifically numerical reasoning (Studies 1 and 2) and figural reasoning (Study 2) – are the only relevant predictors among the intelligence constructs. We discuss the results with reference to the Brunswik symmetry principle. Path models suggest that reasoning and prior knowledge influence problem solving performance in the Tailorshop scenario mainly indirectly. In addition, different types of system-specific knowledge independently contribute to predicting CPS performance. The results of Study 2 indicate that working memory capacity, assessed as an additional predictor, has no incremental validity beyond reasoning. We conclude that (1) cognitive abilities and prior knowledge are substantial predictors of CPS performance, and (2) in contrast to former and recent interpretations, there is insufficient evidence to consider CPS a unique ability construct. In the second part of the paper, we discuss our results in light of recent CPS research, which predominantly utilizes the

PIRPLE: a penalized-likelihood framework for incorporation of prior images in CT reconstruction

International Nuclear Information System (INIS)

Stayman, J Webster; Dang, Hao; Ding, Yifu; Siewerdsen, Jeffrey H

2013-01-01

Over the course of diagnosis and treatment, it is common for a number of imaging studies to be acquired. Such imaging sequences can provide substantial patient-specific prior knowledge about the anatomy that can be incorporated into a prior-image-based tomographic reconstruction for improved image quality and better dose utilization. We present a general methodology using a model-based reconstruction approach including formulations of the measurement noise that also integrates prior images. This penalized-likelihood technique adopts a sparsity enforcing penalty that incorporates prior information yet allows for change between the current reconstruction and the prior image. Moreover, since prior images are generally not registered with the current image volume, we present a modified model-based approach that seeks a joint registration of the prior image in addition to the reconstruction of projection data. We demonstrate that the combined prior-image- and model-based technique outperforms methods that ignore the prior data or lack a noise model. Moreover, we demonstrate the importance of registration for prior-image-based reconstruction methods and show that the prior-image-registered penalized-likelihood estimation (PIRPLE) approach can maintain a high level of image quality in the presence of noisy and undersampled projection data. (paper)

Performance Assessment of a Low-Level Radioactive Waste Disposal Site using GoldSim Integrated Systems Model

Science.gov (United States)

Merrell, G.; Singh, A.; Tauxe, J.; Perona, R.; Dornsife, W.; grisak, G. E.; Holt, R. M.

2011-12-01

Texas Commission on Environmental Quality has approved licenses for four landfills at the Waste Control Specialists (WCS) site located in Andrews County, West Texas. The site includes a hazardous waste landfill and three landfills for radioactive waste. An updated performance assessment is necessary prior to acceptance of waste at the landfills. The updated performance assessment a) provides for more realistic and flexible dose modeling capabilities, b) addresses all plausible release and accident scenarios as they relate to the performance objectives, c) includes impact of climate and hydrologic scenarios that may impact long-term performance of the landfill, d) addresses impact of cover naturalization and degradation on the landfill, and e) incorporates uncertainty and sensitivity analysis for critical parameters. For the updated performance assessment, WCS has developed an integrated systems level performance assessment model using the GoldSim platform. GoldSim serves as a model for integrating all of the major components of a performance assessment, which include the radionuclide source term, facility design, environmental transport pathways, exposure scenarios, and radiological doses. Unlike many computer models that are based on first principles, GoldSim is a systems level model that can be used to integrate and abstract more complex sub-models into one system. This can then be used to assess the results into a unified model of the disposal system and environment. In this particular application, the GoldSim model consists of a) hydrogeologic model that simulates flow and transport through the Dockum geologic unit that underlies all of the waste facilities, b) waste cells that represent the containment unit and simulate degradation of waste forms, radionuclide leaching, and partitioning into the liquid and vapor phase within the waste unit, c) a cover system model that simulates upward diffusive transport from the underground repository to the atmosphere. In

Compressive Online Robust Principal Component Analysis with Multiple Prior Information

DEFF Research Database (Denmark)

Van Luong, Huynh; Deligiannis, Nikos; Seiler, Jürgen

-rank components. Unlike conventional batch RPCA, which processes all the data directly, our method considers a small set of measurements taken per data vector (frame). Moreover, our method incorporates multiple prior information signals, namely previous reconstructed frames, to improve these paration...... and thereafter, update the prior information for the next frame. Using experiments on synthetic data, we evaluate the separation performance of the proposed algorithm. In addition, we apply the proposed algorithm to online video foreground and background separation from compressive measurements. The results show...

Generalized species sampling priors with latent Beta reinforcements

Science.gov (United States)

Airoldi, Edoardo M.; Costa, Thiago; Bassetti, Federico; Leisen, Fabrizio; Guindani, Michele

2014-01-01

Many popular Bayesian nonparametric priors can be characterized in terms of exchangeable species sampling sequences. However, in some applications, exchangeability may not be appropriate. We introduce a novel and probabilistically coherent family of non-exchangeable species sampling sequences characterized by a tractable predictive probability function with weights driven by a sequence of independent Beta random variables. We compare their theoretical clustering properties with those of the Dirichlet Process and the two parameters Poisson-Dirichlet process. The proposed construction provides a complete characterization of the joint process, differently from existing work. We then propose the use of such process as prior distribution in a hierarchical Bayes modeling framework, and we describe a Markov Chain Monte Carlo sampler for posterior inference. We evaluate the performance of the prior and the robustness of the resulting inference in a simulation study, providing a comparison with popular Dirichlet Processes mixtures and Hidden Markov Models. Finally, we develop an application to the detection of chromosomal aberrations in breast cancer by leveraging array CGH data. PMID:25870462

[A school-level longitudinal study of clinical performance examination scores].

Science.gov (United States)

Park, Jang Hee

2015-06-01

This school-level longitudinal study examined 7 years of clinical performance data to determine differences (effects) in students and annual changes within a school and between schools; examine how much their predictors (characteristics) influenced the variation in student performance; and calculate estimates of the schools' initial status and growth. A school-level longitudinal model was tested: level 1 (between students), level 2 (annual change within a school), and level 3 (between schools). The study sample comprised students who belonged to the CPX Consortium (n=5,283 for 2005~2008 and n=4,337 for 2009~2011). Despite a difference between evaluation domains, the performance outcomes were related to individual large-effect differences and small-effect school-level differences. Physical examination, clinical courtesy, and patient education were strongly influenced by the school effect, whereas patient-physician interaction was not affected much. Student scores are influenced by the school effect (differences), and the predictors explain the variation in differences, depending on the evaluation domain.

Recognition of Prior Learning as an integral component of ...

African Journals Online (AJOL)

This is irrespective of whether that learning has been acquired through unstructured learning, performance development, off-the-job assessment, or skills and knowledge that meet workplace needs but have been gained through various previous learning experiences. The concept Recognition of Prior Learning (RPL) is ...

Use of prior mammograms in the classification of benign and malignant masses

International Nuclear Information System (INIS)

Varela, Celia; Karssemeijer, Nico; Hendriks, Jan H.C.L.; Holland, Roland

2005-01-01

The purpose of this study was to determine the importance of using prior mammograms for classification of benign and malignant masses. Five radiologists and one resident classified mass lesions in 198 mammograms obtained from a population-based screening program. Cases were interpreted twice, once without and once with comparison of previous mammograms, in a sequential reading order using soft copy image display. The radiologists' performances in classifying benign and malignant masses without and with previous mammograms were evaluated with receiver operating characteristic (ROC) analysis. The statistical significance of the difference in performances was calculated using analysis of variance. The use of prior mammograms improved the classification performance of all participants in the study. The mean area under the ROC curve of the readers increased from 0.763 to 0.796. This difference in performance was statistically significant (P = 0.008)

Preparing learners with partly incorrect intuitive prior knowledge for learning

Directory of Open Access Journals (Sweden)

Andrea eOhst

2014-07-01

Full Text Available Learners sometimes have incoherent and fragmented intuitive prior knowledge that is (partly ‘incompatible’ with the to-be-learned contents. Such knowledge in pieces can cause conceptual disorientation and cognitive overload while learning. We hypothesized that a pre-training intervention providing a generalized schema as a structuring framework for such knowledge in pieces would support (reorganizing-processes of prior knowledge and thus reduce unnecessary cognitive load during subsequent learning. Fifty-six student teachers participated in the experiment. A framework group underwent a pre-training intervention providing a generalized, categorical schema for categorizing primary learning strategies and related but different strategies as a cognitive framework for (re-organizing their prior knowledge. Our control group received comparable factual information but no framework. Afterwards, all participants learned about primary learning strategies. The framework group claimed to possess higher levels of interest and self-efficacy, achieved higher learning outcomes, and learned more efficiently. Hence, providing a categorical framework can help overcome the barrier of incorrect prior knowledge in pieces.

Preparing learners with partly incorrect intuitive prior knowledge for learning

Science.gov (United States)

Ohst, Andrea; Fondu, Béatrice M. E.; Glogger, Inga; Nückles, Matthias; Renkl, Alexander

2014-01-01

Learners sometimes have incoherent and fragmented intuitive prior knowledge that is (partly) “incompatible” with the to-be-learned contents. Such knowledge in pieces can cause conceptual disorientation and cognitive overload while learning. We hypothesized that a pre-training intervention providing a generalized schema as a structuring framework for such knowledge in pieces would support (re)organizing-processes of prior knowledge and thus reduce unnecessary cognitive load during subsequent learning. Fifty-six student teachers participated in the experiment. A framework group underwent a pre-training intervention providing a generalized, categorical schema for categorizing primary learning strategies and related but different strategies as a cognitive framework for (re-)organizing their prior knowledge. Our control group received comparable factual information but no framework. Afterwards, all participants learned about primary learning strategies. The framework group claimed to possess higher levels of interest and self-efficacy, achieved higher learning outcomes, and learned more efficiently. Hence, providing a categorical framework can help overcome the barrier of incorrect prior knowledge in pieces. PMID:25071638

Chromosomal differences between acute nonlymphocytic leukemia in patients with prior solid tumors and prior hematologic malignancies. A study of 14 cases with prior breast cancer

International Nuclear Information System (INIS)

Mamuris, Z.; Dumont, J.; Dutrillaux, B.; Aurias, A.

1989-01-01

A cytogenetic study of 14 patients with secondary acute nonlymphocytic leukemia (S-ANLL) with prior treatment for breast cancer is reported. The chromosomes recurrently involved in numerical or structural anomalies are chromosomes 7, 5, 17, and 11, in decreasing order of frequency. The distribution of the anomalies detected in this sample of patients is similar to that observed in published cases with prior breast or other solid tumors, though anomalies of chromosome 11 were not pointed out, but it significantly differs from that of the S-ANLL with prior hematologic malignancies. This difference is principally due to a higher involvement of chromosome 7 in patients with prior hematologic malignancies and of chromosomes 11 and 17 in patients with prior solid tumors. A genetic determinism involving abnormal recessive alleles located on chromosomes 5, 7, 11, and 17 uncovered by deletions of the normal homologs may be a cause of S-ANLL. The difference between patients with prior hematologic malignancies or solid tumors may be explained by different constitutional mutations of recessive genes in the two groups of patients

Impact of Educational Level on Performance on Auditory Processing Tests.

Science.gov (United States)

Murphy, Cristina F B; Rabelo, Camila M; Silagi, Marcela L; Mansur, Letícia L; Schochat, Eliane

2016-01-01

Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor "years of schooling" was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills.

Segmentation of kidney using C-V model and anatomy priors

Science.gov (United States)

Lu, Jinghua; Chen, Jie; Zhang, Juan; Yang, Wenjia

2007-12-01

This paper presents an approach for kidney segmentation on abdominal CT images as the first step of a virtual reality surgery system. Segmentation for medical images is often challenging because of the objects' complicated anatomical structures, various gray levels, and unclear edges. A coarse to fine approach has been applied in the kidney segmentation using Chan-Vese model (C-V model) and anatomy prior knowledge. In pre-processing stage, the candidate kidney regions are located. Then C-V model formulated by level set method is applied in these smaller ROI, which can reduce the calculation complexity to a certain extent. At last, after some mathematical morphology procedures, the specified kidney structures have been extracted interactively with prior knowledge. The satisfying results on abdominal CT series show that the proposed approach keeps all the advantages of C-V model and overcome its disadvantages.

Performance assessment handbook for low-level radioactive waste disposal facilities

International Nuclear Information System (INIS)

Seitz, R.R.; Garcia, R.S.; Kostelnik, K.M.; Starmer, R.J.

1992-02-01

Performance assessments of proposed low-level radioactive waste disposal facilities must be conducted to support licensing. This handbook provides a reference document that can be used as a resource by management and staff responsible for performance assessments. Brief discussions describe the performance assessment process and emphasize selected critical aspects of the process. References are also provided for additional information on many aspects of the performance assessment process. The user's manual for the National Low-Level Waste Management Program's Performance Assessment Center (PAC) on the Idaho National Engineering Laboratory Cray computer is included as Appendix A. The PAC provides users an opportunity to experiment with a number of performance assessment computer codes on a Cray computer. Appendix B describes input data required for 22 performance assessment codes

Milestone-specific, Observed data points for evaluating levels of performance (MODEL) assessment strategy for anesthesiology residency programs.

Science.gov (United States)

Nagy, Christopher J; Fitzgerald, Brian M; Kraus, Gregory P

2014-01-01

Anesthesiology residency programs will be expected to have Milestones-based evaluation systems in place by July 2014 as part of the Next Accreditation System. The San Antonio Uniformed Services Health Education Consortium (SAUSHEC) anesthesiology residency program developed and implemented a Milestones-based feedback and evaluation system a year ahead of schedule. It has been named the Milestone-specific, Observed Data points for Evaluating Levels of performance (MODEL) assessment strategy. The "MODEL Menu" and the "MODEL Blueprint" are tools that other anesthesiology residency programs can use in developing their own Milestones-based feedback and evaluation systems prior to ACGME-required implementation. Data from our early experience with the streamlined MODEL blueprint assessment strategy showed substantially improved faculty compliance with reporting requirements. The MODEL assessment strategy provides programs with a workable assessment method for residents, and important Milestones data points to programs for ACGME reporting.

Safety and utility of kyphoplasty prior to spine stereotactic radiosurgery for metastatic tumors: a clinical and dosimetric analysis.

Science.gov (United States)

Barzilai, Ori; DiStefano, Natalie; Lis, Eric; Yamada, Yoshiya; Lovelock, D Michael; Fontanella, Andrew N; Bilsky, Mark H; Laufer, Ilya

2018-01-01

OBJECTIVE The aim of this study was to evaluate the safety and efficacy of kyphoplasty treatment prior to spine stereotactic radiosurgery (SRS) in patients with spine metastases. METHODS A retrospective review of charts, radiology reports, and images was performed for all patients who received SRS (single fraction; either standalone or post-kyphoplasty) at a large tertiary cancer center between January 2012 and July 2015. Patient and tumor variables were documented, as well as treatment planning data and dosimetry. To measure the photon scatter due to polymethyl methacrylate, megavolt photon beam attenuation was determined experimentally as it passed through a kyphoplasty cement phantom. Corrected electron density values were recalculated and compared with uncorrected values. RESULTS Of 192 treatment levels in 164 unique patients who underwent single-fraction SRS, 17 (8.8%) were treated with kyphoplasty prior to radiation delivery to the index level. The median time from kyphoplasty to SRS was 22 days. Four of 192 treatments (2%) demonstrated local tumor recurrence or progression at the time of analysis. Of the 4 local failures, 1 patient had kyphoplasty prior to SRS. This recurrence occurred 18 months after SRS in the setting of widespread systemic disease and spinal tumor progression. Dosimetric review demonstrated a lower than average treatment dose for this case compared with the rest of the cohort. There were no significant differences in dosimetry analysis between the group of patients who underwent kyphoplasty prior to SRS and the remaining patients in the cohort. A preliminary analysis of polymethyl methacrylate showed that dosimetric errors due to uncorrected electron density values were insignificant. CONCLUSIONS In cases without epidural spinal cord compression, stabilization with cement augmentation prior to SRS is safe and does not alter the efficacy of the radiation or preclude physicians from adhering to SRS planning and contouring guidelines.

Accommodating Uncertainty in Prior Distributions

Energy Technology Data Exchange (ETDEWEB)

Picard, Richard Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vander Wiel, Scott Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-01-19

A fundamental premise of Bayesian methodology is that a priori information is accurately summarized by a single, precisely de ned prior distribution. In many cases, especially involving informative priors, this premise is false, and the (mis)application of Bayes methods produces posterior quantities whose apparent precisions are highly misleading. We examine the implications of uncertainty in prior distributions, and present graphical methods for dealing with them.

The Relationship of Learning and Performance Diagnosis at Different System Levels.

Science.gov (United States)

Lubega, Khalid

2003-01-01

Examines learning and performance diagnosis, separately and in relation to each other, as they function in organization systems; explains the relationship between learning and performance diagnosis at the individual, process, and organizational levels using a three-level performance model; and discusses types of learning, including nonlearning,…

Modelling Client Satisfaction Levels: The Impact of Contractor Performance

Directory of Open Access Journals (Sweden)

Robby Soetanto

2012-11-01

Full Text Available The performance of contractors is known to be a key determinant of client satisfaction.Here, using factor analysis, clients’ satisfaction is defined in several dimensions. Based onclients’ assessment of contractor performance, a number of satisfaction models developedusing the multiple regression (MR technique are presented. The models identify arange of variables encompassing contractor performance, project performance and respondent(i.e. client attributes as useful predictors of satisfaction levels. Contractor performanceattributes were found to be of utmost importance indicating that clientsatisfaction levels are mainly dependent on the performance of the contractor. Furthermore,findings suggest that subjectivity is to some extent prevalent in clients’ performanceassessment. The models demonstrate accurate and reliable predictive power as confirmedby validation tests. Contractors could use the models to help improve their performanceleading to more satisfied clients. This would also promote the development ofharmonious working relationships within the construction project coalition.

Ready to rumble: how team personality composition and task conflict interact to improve performance.

Science.gov (United States)

Bradley, Bret H; Klotz, Anthony C; Postlethwaite, Bennett E; Brown, Kenneth G

2013-03-01

Although prior work has proposed a number of conditions under which task conflict in teams may improve performance, composition variables have been left unexplored. Given the effects of personality traits on team processes and outcomes demonstrated in prior work, investigating whether specific personality compositions influence the effect of task conflict on team performance is critical to researchers' understanding of conflict in teams. Our results indicate that team-level averages of both openness to experience and emotional stability function as moderators of the relationship between task conflict and team performance. Specifically, task conflict had a positive impact on performance in teams with high levels of openness or emotional stability; in contrast, task conflict had a negative impact on performance in teams with low levels of openness or emotional stability. Thus, when task conflict emerges, teams composed of members who are open minded or emotionally stable are best able to leverage conflict to improve performance. Implications for theory and practice are discussed.

Understanding sleep disturbance in athletes prior to important competitions.

Science.gov (United States)

Juliff, Laura E; Halson, Shona L; Peiffer, Jeremiah J

2015-01-01

Anecdotally many athletes report worse sleep in the nights prior to important competitions. Despite sleep being acknowledged as an important factor for optimal athletic performance and overall health, little is understood about athlete sleep around competition. The aims of this study were to identify sleep complaints of athletes prior to competitions and determine whether complaints were confined to competition periods. Cross-sectional study. A sample of 283 elite Australian athletes (129 male, 157 female, age 24±5 y) completed two questionnaires; Competitive Sport and Sleep questionnaire and the Pittsburgh Sleep Quality Index. 64.0% of athletes indicated worse sleep on at least one occasion in the nights prior to an important competition over the past 12 months. The main sleep problem specified by athletes was problems falling asleep (82.1%) with the main reasons responsible for poor sleep indicated as thoughts about the competition (83.5%) and nervousness (43.8%). Overall 59.1% of team sport athletes reported having no strategy to overcome poor sleep compared with individual athletes (32.7%, p=0.002) who utilised relaxation and reading as strategies. Individual sport athletes had increased likelihood of poor sleep as they aged. The poor sleep reported by athletes prior to competition was situational rather than a global sleep problem. Poor sleep is common prior to major competitions in Australian athletes, yet most athletes are unaware of strategies to overcome the poor sleep experienced. It is essential coaches and scientists monitor and educate both individual and team sport athletes to facilitate sleep prior to important competitions. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

5 CFR 6701.106 - Prior approval for outside employment.

Science.gov (United States)

2010-01-01

... STANDARDS OF ETHICAL CONDUCT FOR EMPLOYEES OF THE GENERAL SERVICES ADMINISTRATION § 6701.106 Prior approval... to be performed; (4) The name and address of the prospective outside employer for which work will be... affects the outside employer and will disqualify himself from future participation in matters that could...

Impacts of government subsidies on pricing and performance level choice in Energy Performance Contracting: A two-step optimal decision model

International Nuclear Information System (INIS)

Lu, Zhijian; Shao, Shuai

2016-01-01

Highlights: • An ESCO optimal decision model considering governmental subsidies is proposed. • Optimal price and performance level are deduced via a two-stage model. • Demand, profit, and performance level increase with increasing subsidies. • ESCO’s market strategy should firstly focus on high energy consumption industries. • Governmental subsidies standard in different industries should be differentiated. - Abstract: Government subsidies generally play a crucial role in pricing and the choice of performance levels in Energy Performance Contracting (EPC). However, the existing studies pay little attention to how the Energy Service Company (ESCO) prices and chooses performance levels for EPC with government subsidies. To fill such a gap, we propose a joint optimal decision model of pricing and performance level in EPC considering government subsidies. The optimization of the model is achieved via a two-stage process. At the first stage, given a performance level, ESCOs choose the best price; and at the second stage, ESCOs choose the optimal performance level for the optimal price. Furthermore, we carry out a numerical analysis to illuminate such an optimal decision mechanism. The results show that both price sensitivity and performance level sensitivity have significant effects on the choice of performance levels with government subsidies. Government subsidies can induce higher performance levels of EPC, the demand for EPC, and the profit of ESCO. We suggest that ESCO’s market strategy should firstly focus on high energy consumption industries with government subsidies and that government subsidies standard adopted in different industries should be differentiated according to the market characteristics and energy efficiency levels of various industries.

l0 Sparsity for Image Denoising with Local and Global Priors

Directory of Open Access Journals (Sweden)

Xiaoni Gao

2015-01-01

Full Text Available We propose a l0 sparsity based approach to remove additive white Gaussian noise from a given image. To achieve this goal, we combine the local prior and global prior together to recover the noise-free values of pixels. The local prior depends on the neighborhood relationships of a search window to help maintain edges and smoothness. The global prior is generated from a hierarchical l0 sparse representation to help eliminate the redundant information and preserve the global consistency. In addition, to make the correlations between pixels more meaningful, we adopt Principle Component Analysis to measure the similarities, which can be both propitious to reduce the computational complexity and improve the accuracies. Experiments on the benchmark image set show that the proposed approach can achieve superior performance to the state-of-the-art approaches both in accuracy and perception in removing the zero-mean additive white Gaussian noise.

Effects of heavy episodic drinking on physical performance in club level rugby union players.

Science.gov (United States)

Prentice, Christopher; Stannard, Stephen R; Barnes, Matthew J

2015-05-01

This study investigated the effects of acute alcohol consumption, in a natural setting, on exercise performance in the 2 days after the drinking episode. Additionally, alcohol related behaviours of this group of rugby players were identified. Prospective cohort study. Nineteen male club rugby players volunteered for this study. Measures of counter movement jump, maximal lower body strength, repeated sprint ability and hydration were made 2 days before and in the 2 days following heavy episodic alcohol consumption. Participants completed a questionnaire at each time point so that alcohol consumption and sleep hours from the previous 24 h period could be quantified. Additionally, participants completed the Alcohol Use Disorders Test (AUDIT) prior to completing baseline measures of performance. Reported alcohol consumption ranged from 6 to >20 standard drinks (mean category scale score=11-19 standard drinks). A significant decrease in sleep hours (p=0.01) was reported after the drinking episode with participants reporting 1-3 h for the night. A significant reduction (-1.8±1.5 cm) in counter movement jump (p0.05). AUDIT scores for this group (18.2±4.3) indicate regular alcohol consumption at a hazardous level. Heavy episodic alcohol use, and associated reduced sleep hours, results in a reduction in lower body power output but not other measures of anaerobic performance the morning after a drinking session. Full recovery from this behaviour is achieved by 2 days post drinking episode. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

10 CFR 433.5 - Performance level determination.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Performance level determination. 433.5 Section 433.5 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND...) Each Federal agency shall consider laboratory fume hoods and kitchen ventilation systems as part of the...

The effects of individual differences, prior experience and cognitive load on the transfer of dynamic decision-making performance.

Science.gov (United States)

Nicholson, Brad; O'Hare, David

2014-01-01

Situational awareness is recognised as an important factor in the performance of individuals and teams in dynamic decision-making (DDM) environments (Salmon et al. 2014 ). The present study was designed to investigate whether the scores on the WOMBAT™ Situational Awareness and Stress Tolerance Test (Roscoe and North 1980 ) would predict the transfer of DDM performance from training under different levels of cognitive load to a novel situation. Participants practised a simulated firefighting task under either low or high conditions of cognitive load and then performed a (transfer) test in an alternative firefighting environment under an intermediate level of cognitive load. WOMBAT™ test scores were a better predictor of DDM performance than scores on the Raven Matrices. Participants with high WOMBAT™ scores performed better regardless of their training condition. Participants with recent gaming experience who practised under low cognitive load showed better practice phase performance but worse transfer performance than those who practised under high cognitive load. The relationship between task experience, situational awareness ability, cognitive load and the transfer of dynamic decision-making (DDM) performance was investigated. Results showed that the WOMBAT™ test predicted transfer of DDM performance regardless of task cognitive load. The effects of cognitive load on performance varied according to previous task-relevant experience.

Impact of high-performance work systems on individual- and branch-level performance: test of a multilevel model of intermediate linkages.

Science.gov (United States)

Aryee, Samuel; Walumbwa, Fred O; Seidu, Emmanuel Y M; Otaye, Lilian E

2012-03-01

We proposed and tested a multilevel model, underpinned by empowerment theory, that examines the processes linking high-performance work systems (HPWS) and performance outcomes at the individual and organizational levels of analyses. Data were obtained from 37 branches of 2 banking institutions in Ghana. Results of hierarchical regression analysis revealed that branch-level HPWS relates to empowerment climate. Additionally, results of hierarchical linear modeling that examined the hypothesized cross-level relationships revealed 3 salient findings. First, experienced HPWS and empowerment climate partially mediate the influence of branch-level HPWS on psychological empowerment. Second, psychological empowerment partially mediates the influence of empowerment climate and experienced HPWS on service performance. Third, service orientation moderates the psychological empowerment-service performance relationship such that the relationship is stronger for those high rather than low in service orientation. Last, ordinary least squares regression results revealed that branch-level HPWS influences branch-level market performance through cross-level and individual-level influences on service performance that emerges at the branch level as aggregated service performance.

Immigration and Firm Performance: a city-level approach

Directory of Open Access Journals (Sweden)

Mercedes Teruel Carrizosa

2009-10-01

Full Text Available This article analyses the effect of immigration flows on the growthand efficiency of manufacturing firms in Spanish cities. While most studies werefocusing on the effect immigrants have on labour markets at an aggregate level,here, we argue that the impact of immigration on firm performance should not onlybe considered in terms of the labour market, but also in terms of how city’s amenitiescan affect the performance of firms. Implementing a panel data methodology,we show that the immigrants’ increasing pressure has a positive effect on labourproductivity and wages and a negative effect on the job evolution of these manufacturingfirms. In addition, both small and new firms are more sensitive to thepressures of immigrant inflow, while foreign market oriented firms report higherproductivity levels and a less marked impact of immigration than their counterparts.We also present a set of instruments to control for endogeneity. It allows us toconfirm the effect of local immigration flows on the performance of manufacturingfirms.

Elapsed decision time affects the weighting of prior probability in a perceptual decision task

Science.gov (United States)

Hanks, Timothy D.; Mazurek, Mark E.; Kiani, Roozbeh; Hopp, Elizabeth; Shadlen, Michael N.

2012-01-01

Decisions are often based on a combination of new evidence with prior knowledge of the probable best choice. Optimal combination requires knowledge about the reliability of evidence, but in many realistic situations, this is unknown. Here we propose and test a novel theory: the brain exploits elapsed time during decision formation to combine sensory evidence with prior probability. Elapsed time is useful because (i) decisions that linger tend to arise from less reliable evidence, and (ii) the expected accuracy at a given decision time depends on the reliability of the evidence gathered up to that point. These regularities allow the brain to combine prior information with sensory evidence by weighting the latter in accordance with reliability. To test this theory, we manipulated the prior probability of the rewarded choice while subjects performed a reaction-time discrimination of motion direction using a range of stimulus reliabilities that varied from trial to trial. The theory explains the effect of prior probability on choice and reaction time over a wide range of stimulus strengths. We found that prior probability was incorporated into the decision process as a dynamic bias signal that increases as a function of decision time. This bias signal depends on the speed-accuracy setting of human subjects, and it is reflected in the firing rates of neurons in the lateral intraparietal cortex (LIP) of rhesus monkeys performing this task. PMID:21525274

Judging in Rhythmic Gymnastics at Different Levels of Performance.

Science.gov (United States)

Leandro, Catarina; Ávila-Carvalho, Lurdes; Sierra-Palmeiro, Elena; Bobo-Arce, Marta

2017-12-01

This study aimed to analyse the quality of difficulty judging in rhythmic gymnastics, at different levels of performance. The sample consisted of 1152 difficulty scores concerning 288 individual routines, performed in the World Championships in 2013. The data were analysed using the mean absolute judge deviation from the final difficulty score, a Cronbach's alpha coefficient and intra-class correlations, for consistency and reliability assessment. For validity assessment, mean deviations of judges' difficulty scores, the Kendall's coefficient of concordance W and ANOVA eta-squared values were calculated. Overall, the results in terms of consistency (Cronbach's alpha mostly above 0.90) and reliability (intra-class correlations for single and average measures above 0.70 and 0.90, respectively) were satisfactory, in the first and third parts of the ranking on all apparatus. The medium level gymnasts, those in the second part of the ranking, had inferior reliability indices and highest score dispersion. In this part, the minimum of corrected item-total correlation of individual judges was 0.55, with most values well below, and the matrix for between-judge correlations identified remarkable inferior correlations. These findings suggest that the quality of difficulty judging in rhythmic gymnastics may be compromised at certain levels of performance. In future, special attention should be paid to the judging analysis of the medium level gymnasts, as well as the Code of Points applicability at this level.

On the increase of predictive performance with high-level data fusion

International Nuclear Information System (INIS)

Doeswijk, T.G.; Smilde, A.K.; Hageman, J.A.; Westerhuis, J.A.; Eeuwijk, F.A. van

2011-01-01

The combination of the different data sources for classification purposes, also called data fusion, can be done at different levels: low-level, i.e. concatenating data matrices, medium-level, i.e. concatenating data matrices after feature selection and high-level, i.e. combining model outputs. In this paper the predictive performance of high-level data fusion is investigated. Partial least squares is used on each of the data sets and dummy variables representing the classes are used as response variables. Based on the estimated responses y-hat j for data set j and class k, a Gaussian distribution p(g k |y-hat j ) is fitted. A simulation study is performed that shows the theoretical performance of high-level data fusion for two classes and two data sets. Within group correlations of the predicted responses of the two models and differences between the predictive ability of each of the separate models and the fused models are studied. Results show that the error rate is always less than or equal to the best performing subset and can theoretically approach zero. Negative within group correlations always improve the predictive performance. However, if the data sets have a joint basis, as with metabolomics data, this is not likely to happen. For equally performing individual classifiers the best results are expected for small within group correlations. Fusion of a non-predictive classifier with a classifier that exhibits discriminative ability lead to increased predictive performance if the within group correlations are strong. An example with real life data shows the applicability of the simulation results.

The Prior-project

DEFF Research Database (Denmark)

Engerer, Volkmar Paul; Roued-Cunliffe, Henriette; Albretsen, Jørgen

digitisation of Arthur Prior’s Nachlass kept in the Bodleian Library, Oxford. The DH infrastructure in question is the Prior Virtual Lab (PVL). PVL was established in 2011 in order to provide researchers in the field of temporal logic easy access to the papers of Arthur Norman Prior (1914-1969), and officially......In this paper, we present a DH research infrastructure which relies heavily on a combination of domain knowledge with information technology. The general goal is to develop tools to aid scholars in their interpretations and understanding of temporal logic. This in turn is based on an extensive...

Statin Eligibility and Outpatient Care Prior to ST-Segment Elevation Myocardial Infarction.

Science.gov (United States)

Miedema, Michael D; Garberich, Ross F; Schnaidt, Lucas J; Peterson, Erin; Strauss, Craig; Sharkey, Scott; Knickelbine, Thomas; Newell, Marc C; Henry, Timothy D

2017-04-12

The impact of the 2013 American College of Cardiology/American Heart Association cholesterol guidelines on statin eligibility in individuals otherwise destined to experience cardiovascular disease (CVD) events is unclear. We analyzed a prospective cohort of consecutive ST-segment elevation myocardial infarction (STEMI) patients from a regional STEMI system with data on patient demographics, low-density lipoprotein cholesterol levels, CVD risk factors, medication use, and outpatient visits over the 2 years prior to STEMI. We determined pre-STEMI eligibility according to American College of Cardiology/American Heart Association guidelines and the prior Third Report of the Adult Treatment Panel guidelines. Our sample included 1062 patients with a mean age of 63.7 (13.0) years (72.5% male), and 761 (71.7%) did not have known CVD prior to STEMI. Only 62.5% and 19.3% of individuals with and without prior CVD were taking a statin before STEMI, respectively. In individuals not taking a statin, median (interquartile range) low-density lipoprotein cholesterol levels in those with and without known CVD were low (108 [83, 138]  mg/dL and 110 [87, 133] mg/dL). For individuals not taking a statin, only 38.7% were statin eligible by ATP III guidelines. Conversely, 79.0% would have been statin eligible according to American College of Cardiology/American Heart Association guidelines. Less than half of individuals with (49.2%) and without (41.1%) prior CVD had seen a primary care provider during the 2 years prior to STEMI. In a large cohort of STEMI patients, application of American College of Cardiology/American Heart Association guidelines more than doubled pre-STEMI statin eligibility compared with Third Report of the Adult Treatment Panel guidelines. However, access to and utilization of health care, a necessity for guideline implementation, was suboptimal prior to STEMI. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Priming in implicit memory tasks: prior study causes enhanced discriminability, not only bias.

Science.gov (United States)

Zeelenberg, René; Wagenmakers, Eric-Jan M; Raaijmakers, Jeroen G W

2002-03-01

R. Ratcliff and G. McKoon (1995, 1996, 1997; R. Ratcliff, D. Allbritton, & G. McKoon, 1997) have argued that repetition priming effects are solely due to bias. They showed that prior study of the target resulted in a benefit in a later implicit memory task. However, prior study of a stimulus similar to the target resulted in a cost. The present study, using a 2-alternative forced-choice procedure, investigated the effect of prior study in an unbiased condition: Both alternatives were studied prior to their presentation in an implicit memory task. Contrary to a pure bias interpretation of priming, consistent evidence was obtained in 3 implicit memory tasks (word fragment completion, auditory word identification, and picture identification) that performance was better when both alternatives were studied than when neither alternative was studied. These results show that prior study results in enhanced discriminability, not only bias.

Task complexity, student perceptions of vocabulary learning in EFL, and task performance.

Science.gov (United States)

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2013-03-01

The study deepened our understanding of how students' self-efficacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a fine-tuned task-specific level. The aim was to examine the relationship among task complexity, self-efficacy beliefs, domain-related prior knowledge, learning strategy use, and task performance as they were applied to English vocabulary learning from reading tasks. Participants were 120 second-year university students (mean age 21) from a Chinese university. This experiment had two conditions (simple/complex). A vocabulary level test was first conducted to measure participants' prior knowledge of English vocabulary. Participants were then randomly assigned to one of the learning tasks. Participants were administered task booklets together with the self-efficacy scales, measures of learning strategy use, and post-tests. Data obtained were submitted to multivariate analysis of variance (MANOVA) and path analysis. Results from the MANOVA model showed a significant effect of vocabulary level on self-efficacy beliefs, learning strategy use, and task performance. Task complexity showed no significant effect; however, an interaction effect between vocabulary level and task complexity emerged. Results from the path analysis showed self-efficacy beliefs had an indirect effect on performance. Our results highlighted the mediating role of self-efficacy beliefs and learning strategy use. Our findings indicate that students' prior knowledge plays a crucial role on both self-efficacy beliefs and task performance, and the predictive power of self-efficacy on task performance may lie in its association with learning strategy use. © 2011 The British Psychological Society.

Bayesian image reconstruction in SPECT using higher order mechanical models as priors

International Nuclear Information System (INIS)

Lee, S.J.; Gindi, G.; Rangarajan, A.

1995-01-01

While the ML-EM (maximum-likelihood-expectation maximization) algorithm for reconstruction for emission tomography is unstable due to the ill-posed nature of the problem, Bayesian reconstruction methods overcome this instability by introducing prior information, often in the form of a spatial smoothness regularizer. More elaborate forms of smoothness constraints may be used to extend the role of the prior beyond that of a stabilizer in order to capture actual spatial information about the object. Previously proposed forms of such prior distributions were based on the assumption of a piecewise constant source distribution. Here, the authors propose an extension to a piecewise linear model--the weak plate--which is more expressive than the piecewise constant model. The weak plate prior not only preserves edges but also allows for piecewise ramplike regions in the reconstruction. Indeed, for the application in SPECT, such ramplike regions are observed in ground-truth source distributions in the form of primate autoradiographs of rCBF radionuclides. To incorporate the weak plate prior in a MAP approach, the authors model the prior as a Gibbs distribution and use a GEM formulation for the optimization. They compare quantitative performance of the ML-EM algorithm, a GEM algorithm with a prior favoring piecewise constant regions, and a GEM algorithm with the weak plate prior. Pointwise and regional bias and variance of ensemble image reconstructions are used as indications of image quality. The results show that the weak plate and membrane priors exhibit improved bias and variance relative to ML-EM techniques

Performance assessment for low-level radioactive waste disposal

International Nuclear Information System (INIS)

Cook, J.R.; Hsu, R.H.; Wilhite, E.L.; Yu, A.D.

1996-01-01

In October 1994 the Savannah River Site became the first US DOE complex to use concrete vaults to dispose of low-level radioactive solid waste and better prevent soil and groundwater contamination. This article describes the design and gives a performance assessment of the vaults. Topics include the following: Performance objectives; scope; the performance assessment process-assemble a multidisciplinary working group; collect available data; define credible pathways/scenarios; develop conceptual models; conduct screening and detailed model calculations; assess sensitivity/uncertainty; integrate and interpret results; report. 9 figs., 3 tabs

Motivation and Prior Animal Experience of Newly Enrolled Veterinary Nursing Students at two Irish Third-Level Institutions.

Science.gov (United States)

Dunne, Karen; Brereton, Bernadette; Duggan, Vivienne; Campion, Deirdre

2017-11-03

Veterinary nurses report an intrinsic desire to work with animals. However, this motivation may be eroded by poor working conditions and low pay, resulting in the exit of experienced veterinary nurses from clinical practice. This study sought to quantify the level of animal-handling experience students possessed at the start of their training and to explore the factors motivating them to enter veterinary nurse training in two Irish third-level institutions. The authors had noted a tendency for veterinary nursing students to possess limited animal-handling skills, despite their obvious motivation to work with animals. The study explores possible reasons for this, as it mirrors previous reports in relation to students of veterinary medicine. First-year veterinary nursing students at Dundalk Institute of Technology and University College Dublin were surveyed and a focus group was held in each institution to explore student motivations for choosing this career and their prior animal-handling experience and workplace exposure. The results show that veterinary nursing students are highly intrinsically motivated to work with and care for animals. The majority had spent time in the veterinary workplace before starting their studies but they had limited animal-handling experience beyond that of family pets, primarily dogs. The study also revealed potential tensions between the veterinary nursing and veterinary medical students at University College Dublin: a hitherto unexposed aspect of the hidden curriculum in this institution. The results of this study highlight the need for ongoing investment in practical animal-handling training for veterinary nursing students.

Match activities of elite women soccer players at different performance levels

DEFF Research Database (Denmark)

Mohr, Magni; Krustrup, Peter; Andersson, Helena

2008-01-01

, (2) fatigue develops temporarily during and towards the end of a game, and (3) defenders have lower work rates than midfielders and attackers. The difference in high-intensity running between the 2 levels demonstrates the importance of intense intermittent exercise for match performance in women......We sought to study the physical demands and match performance of women soccer players. Nineteen top-class and 15 high-level players were individually videotaped in competitive matches, and time-motion analysis were performed. The players changed locomotor activity >1,300 times in a game...... fewer (P women soccer players (1) top-class international players perform more intervals of high-intensity running than elite players at a lower level...

Impact of Bayesian Priors on the Characterization of Binary Black Hole Coalescences.

Science.gov (United States)

Vitale, Salvatore; Gerosa, Davide; Haster, Carl-Johan; Chatziioannou, Katerina; Zimmerman, Aaron

2017-12-22

In a regime where data are only mildly informative, prior choices can play a significant role in Bayesian statistical inference, potentially affecting the inferred physics. We show this is indeed the case for some of the parameters inferred from current gravitational-wave measurements of binary black hole coalescences. We reanalyze the first detections performed by the twin LIGO interferometers using alternative (and astrophysically motivated) prior assumptions. We find different prior distributions can introduce deviations in the resulting posteriors that impact the physical interpretation of these systems. For instance, (i) limits on the 90% credible interval on the effective black hole spin χ_{eff} are subject to variations of ∼10% if a prior with black hole spins mostly aligned to the binary's angular momentum is considered instead of the standard choice of isotropic spin directions, and (ii) under priors motivated by the initial stellar mass function, we infer tighter constraints on the black hole masses, and in particular, we find no support for any of the inferred masses within the putative mass gap M≲5  M_{⊙}.

Effects of Type of Exploratory Strategy and Prior Knowledge on Middle School Students' Learning of Chemical Formulas from a 3D Role-Playing Game

Science.gov (United States)

Chen, Ming-Puu; Wong, Yu-Ting; Wang, Li-Chun

2014-01-01

The purpose of this study was to examine the effects of the type of exploratory strategy and level of prior knowledge on middle school students' performance and motivation in learning chemical formulas via a 3D role-playing game (RPG). Two types of exploratory strategies-RPG exploratory with worked-example and RPG exploratory without…

The Effects of Prior Outcomes on Risky Choice: Evidence from the Stock Market

Directory of Open Access Journals (Sweden)

Fenghua Wen

2014-01-01

Full Text Available How do prior outcomes affect the risk choice? Research on this can help people to understand investors’ dynamic decisions in financial market. This paper puts forward a new value function. By analyzing the new value function, we find that the prior gains and losses have an impact on the form of value function and the current investors’ risk attitude. Then the paper takes the behavior of the whole stock market as the research object, adopts aggregative index number of 14 representative stocks around the world as samples, and establishes a TVRA-GARCH-M model to investigate the influences of prior gains and losses on the current risk attitude. The empirical study indicates that, at the whole market level, prior gains increase people’s current willingness to take risk assert; that is to say, the house money effect exists in the market, while people are more risk aversion following prior losses.

Stress level and academic performance of university students in ...

African Journals Online (AJOL)

This study examined the relationship between level of stress and students' academic performance in Universities in Kwara State, Nigeria. The study adopted a descriptive survey research design. Proportional stratified random sampling was used to select 300 students for the study. A “Students' Stress Level Questionnaire ...

The Influence of Prior Knowledge on the Retrieval-Directed Function of Note Taking in Prior Knowledge Activation

Science.gov (United States)

Wetzels, Sandra A. J.; Kester, Liesbeth; van Merrienboer, Jeroen J. G.; Broers, Nick J.

2011-01-01

Background: Prior knowledge activation facilitates learning. Note taking during prior knowledge activation (i.e., note taking directed at retrieving information from memory) might facilitate the activation process by enabling learners to build an external representation of their prior knowledge. However, taking notes might be less effective in…

Performance improvement by discharge from different levels in solar storage tanks

DEFF Research Database (Denmark)

Furbo, Simon; Andersen, Elsa; Thür, Alexander

2005-01-01

The thermal advantages by utilizing discharge from different levels in solar storage tanks are investigated, both for a small SDHW system and for a solar combisystem. The investigations showed that it is possible to increase the thermal performance of both types of systems by using two draw......-off levels from the solar tanks instead of one draw-off level at a fixed position. The best position of the second draw-off level is in the middle or just above the middle of the tank. For the investigated small SDHW system with a realistic draw off hot water temperature of 40°C and 45°C and an auxiliary...... volume temperature of 50.5°C the increase of the thermal performance by the second draw-off level is about 6%. For the investigated solar combisystem the extra thermal performance by using one extra draw-off level, either for the domestic hot water heat exchanger or for the heating system, is about 3...

Physical Characteristics and Performance of Japanese Top-Level American Football Players.

Science.gov (United States)

Yamashita, Daichi; Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

2017-09-01

Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455-2461, 2017-This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance.

Exercise training normalizes skeletal muscle vascular endothelial growth factor levels in patients with essential hypertension

DEFF Research Database (Denmark)

Hansen, Ane Håkansson; Nielsen, Jens Jung; Saltin, Bengt

2010-01-01

METHODS: Vascular endothelial growth factor (VEGF) protein and capillarization were determined in muscle vastus lateralis biopsy samples in individuals with essential hypertension (n = 10) and normotensive controls (n = 10). The hypertensive individuals performed exercise training for 16 weeks....... Muscle samples as well as muscle microdialysis fluid samples were obtained at rest, during and after an acute exercise bout, performed prior to and after the training period, for the determination of muscle VEGF levels, VEGF release, endothelial cell proliferative effect and capillarization. RESULTS......: Prior to training, the hypertensive individuals had 36% lower levels of VEGF protein and 22% lower capillary density in the muscle compared to controls. Training in the hypertensive group reduced (P

The Concept of Performance Levels in Criterion-Referenced Assessment.

Science.gov (United States)

Hewitson, Mal

The concept of performance levels in criterion-referenced assessment is explored by applying the idea to different types of tests commonly used in schools, mastery tests (including diagnostic tests) and achievement tests. In mastery tests, a threshold performance standard must be established for each criterion. Attainment of this threshold…

Varying prior information in Bayesian inversion

International Nuclear Information System (INIS)

Walker, Matthew; Curtis, Andrew

2014-01-01

Bayes' rule is used to combine likelihood and prior probability distributions. The former represents knowledge derived from new data, the latter represents pre-existing knowledge; the Bayesian combination is the so-called posterior distribution, representing the resultant new state of knowledge. While varying the likelihood due to differing data observations is common, there are also situations where the prior distribution must be changed or replaced repeatedly. For example, in mixture density neural network (MDN) inversion, using current methods the neural network employed for inversion needs to be retrained every time prior information changes. We develop a method of prior replacement to vary the prior without re-training the network. Thus the efficiency of MDN inversions can be increased, typically by orders of magnitude when applied to geophysical problems. We demonstrate this for the inversion of seismic attributes in a synthetic subsurface geological reservoir model. We also present results which suggest that prior replacement can be used to control the statistical properties (such as variance) of the final estimate of the posterior in more general (e.g., Monte Carlo based) inverse problem solutions. (paper)

45 CFR 305.33 - Determination of applicable percentages based on performance levels.

Science.gov (United States)

2010-10-01

..., DEPARTMENT OF HEALTH AND HUMAN SERVICES PROGRAM PERFORMANCE MEASURES, STANDARDS, FINANCIAL INCENTIVES, AND PENALTIES § 305.33 Determination of applicable percentages based on performance levels. (a) A State's... performance levels. 305.33 Section 305.33 Public Welfare Regulations Relating to Public Welfare OFFICE OF...

The impact of educational level on performance on auditory processing tests

Directory of Open Access Journals (Sweden)

Cristina F.B. Murphy

2016-03-01

Full Text Available Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor years of schooling was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills.

The Prior Internet Resources 2017

DEFF Research Database (Denmark)

Engerer, Volkmar Paul; Albretsen, Jørgen

2017-01-01

The Prior Internet Resources (PIR) are presented. Prior’s unpublished scientific manuscripts and his wast letter correspondence with fellow researchers at the time, his Nachlass, is now subject to transcription by Prior-researchers worldwide, and form an integral part of PIR. It is demonstrated...

Addressing Omitted Prior Achievement Bias in International Assessments: An Applied Example Using PIRLS-NPD Matched Data

Science.gov (United States)

Caro, Daniel H.; Kyriakides, Leonidas; Televantou, Ioulia

2018-01-01

Omitted prior achievement bias is pervasive in international assessment studies and precludes causal inference. For example, reported negative associations between student-oriented teaching strategies and student performance are against expectations and might actually reflect omitted prior achievement bias. Namely, that these teaching strategies…

Fast Markov chain Monte Carlo sampling for sparse Bayesian inference in high-dimensional inverse problems using L1-type priors

International Nuclear Information System (INIS)

Lucka, Felix

2012-01-01

Sparsity has become a key concept for solving of high-dimensional inverse problems using variational regularization techniques. Recently, using similar sparsity-constraints in the Bayesian framework for inverse problems by encoding them in the prior distribution has attracted attention. Important questions about the relation between regularization theory and Bayesian inference still need to be addressed when using sparsity promoting inversion. A practical obstacle for these examinations is the lack of fast posterior sampling algorithms for sparse, high-dimensional Bayesian inversion. Accessing the full range of Bayesian inference methods requires being able to draw samples from the posterior probability distribution in a fast and efficient way. This is usually done using Markov chain Monte Carlo (MCMC) sampling algorithms. In this paper, we develop and examine a new implementation of a single component Gibbs MCMC sampler for sparse priors relying on L1-norms. We demonstrate that the efficiency of our Gibbs sampler increases when the level of sparsity or the dimension of the unknowns is increased. This property is contrary to the properties of the most commonly applied Metropolis–Hastings (MH) sampling schemes. We demonstrate that the efficiency of MH schemes for L1-type priors dramatically decreases when the level of sparsity or the dimension of the unknowns is increased. Practically, Bayesian inversion for L1-type priors using MH samplers is not feasible at all. As this is commonly believed to be an intrinsic feature of MCMC sampling, the performance of our Gibbs sampler also challenges common beliefs about the applicability of sample based Bayesian inference. (paper)

Penalised Complexity Priors for Stationary Autoregressive Processes

KAUST Repository

Sø rbye, Sigrunn Holbek; Rue, Haavard

2017-01-01

The autoregressive (AR) process of order p(AR(p)) is a central model in time series analysis. A Bayesian approach requires the user to define a prior distribution for the coefficients of the AR(p) model. Although it is easy to write down some prior, it is not at all obvious how to understand and interpret the prior distribution, to ensure that it behaves according to the users' prior knowledge. In this article, we approach this problem using the recently developed ideas of penalised complexity (PC) priors. These prior have important properties like robustness and invariance to reparameterisations, as well as a clear interpretation. A PC prior is computed based on specific principles, where model component complexity is penalised in terms of deviation from simple base model formulations. In the AR(1) case, we discuss two natural base model choices, corresponding to either independence in time or no change in time. The latter case is illustrated in a survival model with possible time-dependent frailty. For higher-order processes, we propose a sequential approach, where the base model for AR(p) is the corresponding AR(p-1) model expressed using the partial autocorrelations. The properties of the new prior distribution are compared with the reference prior in a simulation study.

Penalised Complexity Priors for Stationary Autoregressive Processes

KAUST Repository

Sørbye, Sigrunn Holbek

2017-05-25

The autoregressive (AR) process of order p(AR(p)) is a central model in time series analysis. A Bayesian approach requires the user to define a prior distribution for the coefficients of the AR(p) model. Although it is easy to write down some prior, it is not at all obvious how to understand and interpret the prior distribution, to ensure that it behaves according to the users\\' prior knowledge. In this article, we approach this problem using the recently developed ideas of penalised complexity (PC) priors. These prior have important properties like robustness and invariance to reparameterisations, as well as a clear interpretation. A PC prior is computed based on specific principles, where model component complexity is penalised in terms of deviation from simple base model formulations. In the AR(1) case, we discuss two natural base model choices, corresponding to either independence in time or no change in time. The latter case is illustrated in a survival model with possible time-dependent frailty. For higher-order processes, we propose a sequential approach, where the base model for AR(p) is the corresponding AR(p-1) model expressed using the partial autocorrelations. The properties of the new prior distribution are compared with the reference prior in a simulation study.

High-level waste-form-product performance evaluation

International Nuclear Information System (INIS)

Bernadzikowski, T.A.; Allender, J.S.; Stone, J.A.; Gordon, D.E.; Gould, T.H. Jr.; Westberry, C.F. III.

1982-01-01

Seven candidate waste forms were evaluated for immobilization and geologic disposal of high-level radioactive wastes. The waste forms were compared on the basis of leach resistance, mechanical stability, and waste loading. All forms performed well at leaching temperatures of 40, 90, and 150 0 C. Ceramic forms ranked highest, followed by glasses, a metal matrix form, and concrete. 11 tables

Intelligence Level Performance Standards Research for Autonomous Vehicles.

Science.gov (United States)

Bostelman, Roger B; Hong, Tsai H; Messina, Elena

2015-01-01

United States and European safety standards have evolved to protect workers near Automatic Guided Vehicles (AGV's). However, performance standards for AGV's and mobile robots have only recently begun development. Lessons can be learned from research and standards efforts for mobile robots applied to emergency response and military applications. Research challenges, tests and evaluations, and programs to develop higher intelligence levels for vehicles can also used to guide industrial AGV developments towards more adaptable and intelligent systems. These other efforts also provide useful standards development criteria for AGV performance test methods. Current standards areas being considered for AGVs are for docking, navigation, obstacle avoidance, and the ground truth systems that measure performance. This paper provides a look to the future with standards developments in both the performance of vehicles and the dynamic perception systems that measure intelligent vehicle performance.

Prior exercise and antioxidant supplementation: effect on oxidative stress and muscle injury

Directory of Open Access Journals (Sweden)

Schilling Brian K

2007-10-01

Full Text Available Abstract Background Both acute bouts of prior exercise (preconditioning and antioxidant nutrients have been used in an attempt to attenuate muscle injury or oxidative stress in response to resistance exercise. However, most studies have focused on untrained participants rather than on athletes. The purpose of this work was to determine the independent and combined effects of antioxidant supplementation (vitamin C + mixed tocopherols/tocotrienols and prior eccentric exercise in attenuating markers of skeletal muscle injury and oxidative stress in resistance trained men. Methods Thirty-six men were randomly assigned to: no prior exercise + placebo; no prior exercise + antioxidant; prior exercise + placebo; prior exercise + antioxidant. Markers of muscle/cell injury (muscle performance, muscle soreness, C-reactive protein, and creatine kinase activity, as well as oxidative stress (blood protein carbonyls and peroxides, were measured before and through 48 hours of exercise recovery. Results No group by time interactions were noted for any variable (P > 0.05. Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P Conclusion There appears to be no independent or combined effect of a prior bout of eccentric exercise or antioxidant supplementation as used here on markers of muscle injury in resistance trained men. Moreover, eccentric exercise as used in the present study results in minimal blood oxidative stress in resistance trained men. Hence, antioxidant supplementation for the purpose of minimizing blood oxidative stress in relation to eccentric exercise appears unnecessary in this population.

IMMEDIATE RECIPROCAL CHANGES AT ADJACENT LEVEL FOLLOWING SINGLE-LEVEL ALIF

Directory of Open Access Journals (Sweden)

Enrique Vargas Uribe

2015-12-01

Full Text Available Objective : To assess the segmental sagittal parameters and the adjacent mobile segment after interbody fusion by anterior approach in single-level L5-S1. Methods : Retrospective study. Inclusion: Interbody fusion by anterior approach (10°/15° angle, due to DDD, low-grade spondylolisthesis and/or stenosis without prior lumbar fusion. Thirty-five cases were included (25 women; mean age 47±15 years. Analysis of lumbar radiographs were performed preoperatively and 3 months after surgery. The following parameters were evaluated: lumbar lordosis; segmental lordosis L4-L5 and L5-S1; sacral and L5 slope. Two independent evaluators made the measurements. Student's t test was used. Results : There was correction of lordosis at the L5-S1 level, from an average of 19° prior to surgery to 28° three months after surgery (p<0.001. It was observed reduction of the L4-L5 angle from 17° to 14° (p <0.001. Moreover, there was a small, but statistically significant, reduction of L5 inclination from 17 ° to 13 ° (p=0.007 and increase in the sacral slope from 37° to 40° (p=0.002. The change of total lumbar lordosis was not significant: 52° versus 53° (p=0.461. Before surgical correction, lordosis of the L5-S1 level contributed, on average, 37% of lumbar lordosis, and after, 54% (p<0.001. The L4-L5 level accounted for 34% and decreased to 24% (p<0.001. Conclusion : In the group studied, it was observed a decrease in lordosis of the adjacent mobile level following the treatment of the degenerate level by anterior interbody fusion and concomitant increase in lordosis.

Generalized Bayesian inference with sets of conjugate priors for dealing with prior-data conflict : course at Lund University

NARCIS (Netherlands)

Walter, G.

2015-01-01

In the Bayesian approach to statistical inference, possibly subjective knowledge on model parameters can be expressed by so-called prior distributions. A prior distribution is updated, via Bayes’ Rule, to the so-called posterior distribution, which combines prior information and information from

The Importance of Prior Knowledge.

Science.gov (United States)

Cleary, Linda Miller

1989-01-01

Recounts a college English teacher's experience of reading and rereading Noam Chomsky, building up a greater store of prior knowledge. Argues that Frank Smith provides a theory for the importance of prior knowledge and Chomsky's work provided a personal example with which to interpret and integrate that theory. (RS)

Chip-Level Channel Equalization in WCDMA Downlink

Directory of Open Access Journals (Sweden)

Kari Hooli

2002-08-01

Full Text Available The most important third generation (3G cellular communications standard is based on wideband CDMA (WCDMA. Receivers based on TDMA style channel equalization at the chip level have been proposed for a WCDMA downlink employing long spreading sequences to ensure adequate performance even with a high number of active users. These receivers equalize the channel prior to despreading, thus restoring the orthogonality of users and resulting in multiple-access interference (MAI suppression. In this paper, an overview of chip-level channel equalizers is delivered with special attention to adaptation methods suitable for the WCDMA downlink. Numerical examples on the equalizers′ performance are given in Rayleigh fading frequency-selective channels.

Application of Adjusted Canonical Correlation Analysis (ACCA) to study the association between mathematics in Level 1 and Level 2 and performance of engineering disciplines in Level 2

Science.gov (United States)

Peiris, T. S. G.; Nanayakkara, K. A. D. S. A.

2017-09-01

Mathematics plays a key role in engineering sciences as it assists to develop the intellectual maturity and analytical thinking of engineering students and exploring the student academic performance has received great attention recently. The lack of control over covariates motivates the need for their adjustment when measuring the degree of association between two sets of variables in Canonical Correlation Analysis (CCA). Thus to examine the individual effects of mathematics in Level 1 and Level 2 on engineering performance in Level 2, two adjusted analyses in CCA: Part CCA and Partial CCA were applied for the raw marks of engineering undergraduates for three different disciplines, at the Faculty of Engineering, University of Moratuwa, Sri Lanka. The joint influence of mathematics in Level 1 and Level 2 is significant on engineering performance in Level 2 irrespective of the engineering disciplines. The individual effect of mathematics in Level 2 is significantly higher compared to the individual effect of mathematics in Level 1 on engineering performance in Level 2. Furthermore, the individual effect of mathematics in Level 1 can be negligible. But, there would be a notable indirect effect of mathematics in Level 1 on engineering performance in Level 2. It can be concluded that the joint effect of mathematics in both Level 1 and Level 2 is immensely beneficial to improve the overall academic performance at the end of Level 2 of the engineering students. Furthermore, it was found that the impact mathematics varies among engineering disciplines. As partial CCA and partial CCA are not widely explored in applied work, it is recommended to use these techniques for various applications.

Predicting Attrition, Performance, Reenlistment, and Hospitalizations from the Smoking History of Women Prior to Entering the Navy

National Research Council Canada - National Science Library

Conway, Terry L

2006-01-01

This study of women sailors examined whether tobacco use prior to entering the Navy predicted subsequent career outcomes related to length of service, early attrition, misconduct, and hospitalizations...

New Riemannian Priors on the Univariate Normal Model

Directory of Open Access Journals (Sweden)

Salem Said

2014-07-01

Full Text Available The current paper introduces new prior distributions on the univariate normal model, with the aim of applying them to the classification of univariate normal populations. These new prior distributions are entirely based on the Riemannian geometry of the univariate normal model, so that they can be thought of as “Riemannian priors”. Precisely, if {pθ ; θ ∈ Θ} is any parametrization of the univariate normal model, the paper considers prior distributions G( θ - , γ with hyperparameters θ - ∈ Θ and γ > 0, whose density with respect to Riemannian volume is proportional to exp(−d2(θ, θ - /2γ2, where d2(θ, θ - is the square of Rao’s Riemannian distance. The distributions G( θ - , γ are termed Gaussian distributions on the univariate normal model. The motivation for considering a distribution G( θ - , γ is that this distribution gives a geometric representation of a class or cluster of univariate normal populations. Indeed, G( θ - , γ has a unique mode θ - (precisely, θ - is the unique Riemannian center of mass of G( θ - , γ, as shown in the paper, and its dispersion away from θ - is given by γ.  Therefore, one thinks of members of the class represented by G( θ - , γ as being centered around θ - and  lying within a typical  distance determined by γ. The paper defines rigorously the Gaussian distributions G( θ - , γ and describes an algorithm for computing maximum likelihood estimates of their hyperparameters. Based on this algorithm and on the Laplace approximation, it describes how the distributions G( θ - , γ can be used as prior distributions for Bayesian classification of large univariate normal populations. In a concrete application to texture image classification, it is shown that  this  leads  to  an  improvement  in  performance  over  the  use  of  conjugate  priors.

Incorporating outcome uncertainty and prior outcome beliefs in stated preferences

DEFF Research Database (Denmark)

Lundhede, Thomas; Jacobsen, Jette Bredahl; Hanley, Nick

2015-01-01

Stated preference studies tell respondents that policies create environmental changes with varying levels of uncertainty. However, respondents may include their own a priori assessments of uncertainty when making choices among policy options. Using a choice experiment eliciting respondents......’ preferences for conservation policies under climate change, we find that higher outcome uncertainty reduces utility. When accounting for endogeneity, we find that prior beliefs play a significant role in this cost of uncertainty. Thus, merely stating “objective” levels of outcome uncertainty...

Nanofluid of zinc oxide nanoparticles in ionic liquid for single drop liquid microextraction of fungicides in environmental waters prior to high performance liquid chromatographic analysis.

Science.gov (United States)

Amde, Meseret; Tan, Zhi-Qiang; Liu, Rui; Liu, Jing-Fu

2015-05-22

Using a nanofluid obtained by dispersing ZnO nanoparticles (ZnO NPs) in 1-hexyl-3-methylimidazolium hexafluorophosphate, new single drop microextraction method was developed for simultaneous extraction of three fungicides (chlorothalonil, kresoxim-methyl and famoxadone) in water samples prior to their analysis by high performance liquid chromatography (HPLC-VWD). The parameters affecting the extraction efficiency such as amount of ZnO NPs in the nanofluid, solvent volume, extraction time, stirring rate, pH and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.13-0.19ng/mL, the precision of the method assessed with intra-day and inter-day relative standard deviations were water samples including lake water, river water, as well as effluent and influent of wastewater treatment plant, with recoveries in the range of 74.94-96.11% at 5ng/mL spiking level. Besides to being environmental friendly, the high enrichment factor and the data quality obtained with the proposed method demonstrated its potential for application in multi residue analysis of fungicides in actual water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

A Habermasian Analysis of a Process of Recognition of Prior Learning for Health Care Assistants

Science.gov (United States)

Sandberg, Fredrik

2012-01-01

This article discusses a process of recognition of prior learning for accreditation of prior experiential learning to qualify for course credits used in an adult in-service education program for health care assistants at the upper-secondary level in Sweden. The data are based on interviews and observations drawn from a field study, and Habermas's…

Real earnings management activities prior to bond issuance

Directory of Open Access Journals (Sweden)

Cristhian Mellado-Cid

2017-07-01

Full Text Available We examine real activities manipulation by firms prior to their debt issuances and how such manipulation activities affect bond yield spreads. We find that bond-issuing firms increase their real activities manipulation in the five quarters leading to a bond issuance. We document an inverse association between yield spread and pre-issue real activities manipulation, i.e., firms engaged in abnormally high levels of real activities manipulation are associated with subsequent lower cost of debt.

Level-3 Cholesky Factorization Routines Improve Performance of Many Cholesky Algorithms

DEFF Research Database (Denmark)

Gustavson, Fred G.; Wasniewski, Jerzy; Dongarra, Jack J.

2013-01-01

Four routines called DPOTF3i, i = a,b,c,d, are presented. DPOTF3i are a novel type of level-3 BLAS for use by BPF (Blocked Packed Format) Cholesky factorization and LAPACK routine DPOTRF. Performance of routines DPOTF3i are still increasing when the performance of Level-2 routine DPOTF2 of LAPACK...

Magnetic resonance imaging and magnetic resonance arthrography of the shoulder: dependence on the level of training of the performing radiologist for diagnostic accuracy

Energy Technology Data Exchange (ETDEWEB)

Theodoropoulos, John S. [University of Toronto, Division of Orthopaedics, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); Andreisek, Gustav [University of Toronto, Department of Medical Imaging, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); University Hospital Zuerich, Institute for Diagnostic Radiology, Zuerich (Switzerland); Harvey, Edward J. [McGill University, Division of Orthopaedics, MUHC - Montreal General Hospital, Montreal, Quebec (Canada); Wolin, Preston [Center for Athletic Medicine, Chicago, IL (United States)

2010-07-15

Discrepancies were identified between magnetic resonance (MR) imaging and clinical findings in patients who had MR imaging examinations evaluated by community-based general radiologists. The purpose of this study was to evaluate the diagnostic performance of MR imaging examinations of the shoulder with regard to the training level of the performing radiologist. A review of patient charts identified 238 patients (male/female, 175/63; mean age, 40.4 years) in whom 250 arthroscopies were performed and who underwent MR imaging or direct MR arthrography in either a community-based or hospital-based institution prior to surgery. All MR imaging and surgical reports were reviewed and the diagnostic performance for the detection of labral, rotator cuff, biceps, and Hill-Sachs lesions was determined. Kappa and Student's t test analyses were performed in a subset of cases in which initial community-based MR images were re-evaluated by hospital-based musculoskeletal radiologists, to determine the interobserver agreement and any differences in image interpretation. The diagnostic performance of community-based general radiologists was lower than that of hospital-based sub-specialized musculoskeletal radiologists. A sub-analysis of re-evaluated cases showed that musculoskeletal radiologists performed better. {kappa} values were 0.208, 0.396, 0.376, and 0.788 for labral, rotator cuff, biceps, and Hill-Sachs lesions (t test statistics: p =<0.001, 0.004, 0.019, and 0.235). Our results indicate that the diagnostic performance of MR imaging and MR arthrography of the shoulder depends on the training level of the performing radiologist, with sub-specialized musculoskeletal radiologists having a better diagnostic performance than general radiologists. (orig.)

Savings for visuomotor adaptation require prior history of error, not prior repetition of successful actions.

Science.gov (United States)

Leow, Li-Ann; de Rugy, Aymar; Marinovic, Welber; Riek, Stephan; Carroll, Timothy J

2016-10-01

When we move, perturbations to our body or the environment can elicit discrepancies between predicted and actual outcomes. We readily adapt movements to compensate for such discrepancies, and the retention of this learning is evident as savings, or faster readaptation to a previously encountered perturbation. The mechanistic processes contributing to savings, or even the necessary conditions for savings, are not fully understood. One theory suggests that savings requires increased sensitivity to previously experienced errors: when perturbations evoke a sequence of correlated errors, we increase our sensitivity to the errors experienced, which subsequently improves error correction (Herzfeld et al. 2014). An alternative theory suggests that a memory of actions is necessary for savings: when an action becomes associated with successful target acquisition through repetition, that action is more rapidly retrieved at subsequent learning (Huang et al. 2011). In the present study, to better understand the necessary conditions for savings, we tested how savings is affected by prior experience of similar errors and prior repetition of the action required to eliminate errors using a factorial design. Prior experience of errors induced by a visuomotor rotation in the savings block was either prevented at initial learning by gradually removing an oppositely signed perturbation or enforced by abruptly removing the perturbation. Prior repetition of the action required to eliminate errors in the savings block was either deprived or enforced by manipulating target location in preceding trials. The data suggest that prior experience of errors is both necessary and sufficient for savings, whereas prior repetition of a successful action is neither necessary nor sufficient for savings. Copyright © 2016 the American Physiological Society.

Neutrino masses and their ordering: global data, priors and models

Science.gov (United States)

Gariazzo, S.; Archidiacono, M.; de Salas, P. F.; Mena, O.; Ternes, C. A.; Tórtola, M.

2018-03-01

We present a full Bayesian analysis of the combination of current neutrino oscillation, neutrinoless double beta decay and Cosmic Microwave Background observations. Our major goal is to carefully investigate the possibility to single out one neutrino mass ordering, namely Normal Ordering or Inverted Ordering, with current data. Two possible parametrizations (three neutrino masses versus the lightest neutrino mass plus the two oscillation mass splittings) and priors (linear versus logarithmic) are exhaustively examined. We find that the preference for NO is only driven by neutrino oscillation data. Moreover, the values of the Bayes factor indicate that the evidence for NO is strong only when the scan is performed over the three neutrino masses with logarithmic priors; for every other combination of parameterization and prior, the preference for NO is only weak. As a by-product of our Bayesian analyses, we are able to (a) compare the Bayesian bounds on the neutrino mixing parameters to those obtained by means of frequentist approaches, finding a very good agreement; (b) determine that the lightest neutrino mass plus the two mass splittings parametrization, motivated by the physical observables, is strongly preferred over the three neutrino mass eigenstates scan and (c) find that logarithmic priors guarantee a weakly-to-moderately more efficient sampling of the parameter space. These results establish the optimal strategy to successfully explore the neutrino parameter space, based on the use of the oscillation mass splittings and a logarithmic prior on the lightest neutrino mass, when combining neutrino oscillation data with cosmology and neutrinoless double beta decay. We also show that the limits on the total neutrino mass ∑ mν can change dramatically when moving from one prior to the other. These results have profound implications for future studies on the neutrino mass ordering, as they crucially state the need for self-consistent analyses which explore the

Quantitative utilization of prior biological knowledge in the Bayesian network modeling of gene expression data

Directory of Open Access Journals (Sweden)

Gao Shouguo

2011-08-01

Full Text Available Abstract Background Bayesian Network (BN is a powerful approach to reconstructing genetic regulatory networks from gene expression data. However, expression data by itself suffers from high noise and lack of power. Incorporating prior biological knowledge can improve the performance. As each type of prior knowledge on its own may be incomplete or limited by quality issues, integrating multiple sources of prior knowledge to utilize their consensus is desirable. Results We introduce a new method to incorporate the quantitative information from multiple sources of prior knowledge. It first uses the Naïve Bayesian classifier to assess the likelihood of functional linkage between gene pairs based on prior knowledge. In this study we included cocitation in PubMed and schematic similarity in Gene Ontology annotation. A candidate network edge reservoir is then created in which the copy number of each edge is proportional to the estimated likelihood of linkage between the two corresponding genes. In network simulation the Markov Chain Monte Carlo sampling algorithm is adopted, and samples from this reservoir at each iteration to generate new candidate networks. We evaluated the new algorithm using both simulated and real gene expression data including that from a yeast cell cycle and a mouse pancreas development/growth study. Incorporating prior knowledge led to a ~2 fold increase in the number of known transcription regulations recovered, without significant change in false positive rate. In contrast, without the prior knowledge BN modeling is not always better than a random selection, demonstrating the necessity in network modeling to supplement the gene expression data with additional information. Conclusion our new development provides a statistical means to utilize the quantitative information in prior biological knowledge in the BN modeling of gene expression data, which significantly improves the performance.

Performance Evaluation of Fusing Protected Fingerprint Minutiae Templates on the Decision Level

Directory of Open Access Journals (Sweden)

Raymond N. J. Veldhuis

2012-04-01

Full Text Available In a biometric authentication system using protected templates, a pseudonymous identifier is the part of a protected template that can be directly compared. Each compared pair of pseudonymous identifiers results in a decision testing whether both identifiers are derived from the same biometric characteristic. Compared to an unprotected system, most existing biometric template protection methods cause to a certain extent degradation in biometric performance. Fusion is therefore a promising way to enhance the biometric performance in template-protected biometric systems. Compared to feature level fusion and score level fusion, decision level fusion has not only the least fusion complexity, but also the maximum interoperability across different biometric features, template protection and recognition algorithms, templates formats, and comparison score rules. However, performance improvement via decision level fusion is not obvious. It is influenced by both the dependency and the performance gap among the conducted tests for fusion. We investigate in this paper several fusion scenarios (multi-sample, multi-instance, multi-sensor, multi-algorithm, and their combinations on the binary decision level, and evaluate their biometric performance and fusion efficiency on a multi-sensor fingerprint database with 71,994 samples.

Performance Evaluation of Fusing Protected Fingerprint Minutiae Templates on the Decision Level

Science.gov (United States)

Yang, Bian; Busch, Christoph; de Groot, Koen; Xu, Haiyun; Veldhuis, Raymond N. J.

2012-01-01

In a biometric authentication system using protected templates, a pseudonymous identifier is the part of a protected template that can be directly compared. Each compared pair of pseudonymous identifiers results in a decision testing whether both identifiers are derived from the same biometric characteristic. Compared to an unprotected system, most existing biometric template protection methods cause to a certain extent degradation in biometric performance. Fusion is therefore a promising way to enhance the biometric performance in template-protected biometric systems. Compared to feature level fusion and score level fusion, decision level fusion has not only the least fusion complexity, but also the maximum interoperability across different biometric features, template protection and recognition algorithms, templates formats, and comparison score rules. However, performance improvement via decision level fusion is not obvious. It is influenced by both the dependency and the performance gap among the conducted tests for fusion. We investigate in this paper several fusion scenarios (multi-sample, multi-instance, multi-sensor, multi-algorithm, and their combinations) on the binary decision level, and evaluate their biometric performance and fusion efficiency on a multi-sensor fingerprint database with 71,994 samples. PMID:22778583

Divergent Priors and well Behaved Bayes Factors

NARCIS (Netherlands)

R.W. Strachan (Rodney); H.K. van Dijk (Herman)

2011-01-01

textabstractDivergent priors are improper when defined on unbounded supports. Bartlett's paradox has been taken to imply that using improper priors results in ill-defined Bayes factors, preventing model comparison by posterior probabilities. However many improper priors have attractive properties

Pavlovian autoshaping procedures increase plasma corticosterone levels in rats.

Science.gov (United States)

Tomie, Arthur; Silberman, Yuval; Williams, Kayon; Pohorecky, Larissa A

2002-06-01

Pavlovian autoshaping conditioned responses (CRs) are complex sequences of conditioned stimulus (CS)-directed skeletal-motor responses that are elicited by CS objects predictive of food unconditioned stimulus (US). Autoshaping CRs are observed under conditions known to be conducive to elevations in plasma corticosterone levels, as, for example, in response to the eating of food as well as in response to signals predictive of food. Two experiments investigated the relationships between Pavlovian autoshaping procedures, the performance of Pavlovian autoshaping CRs, and plasma corticosterone levels in male Long-Evans rats. In Experiment 1, rats in the CS-US paired group (n=30) were given 20 daily sessions of Pavlovian autoshaping training wherein the insertion of a retractable lever CS was followed by the response-independent presentation of the food US. Tail blood samples obtained after the 20th autoshaping session revealed higher plasma corticosterone levels in the CS-US paired group than in the CS-US random control group (n=10). In Experiment 2, rats (n=35) were assessed for basal plasma corticosterone levels 2 weeks prior to autoshaping training. Plasma samples obtained immediately following the first autoshaping session, and prior to the acquisition of lever-press autoshaping CR performance, revealed higher plasma corticosterone levels in the CS-US paired group (n=24) relative to basal levels. This effect was not observed in the CS-US random control group (n=11). Data suggest that corticosterone release is a physiological endocrine Pavlovian CR induced by lever CS-food US pairings during Pavlovian autoshaping procedures, rather than a by-product of autoshaping CR performance. Implications of the link between autoshaping procedures and corticosterone release are discussed.

Analysis of performance and stress caused by a simulation of a mass casualty incident.

Science.gov (United States)

Nieto Fernández-Pacheco, Antonio; Castro Delgado, Rafael; Arcos González, Pedro; Navarro Fernández, José Luis; Cerón Madrigal, José Joaquín; Juguera Rodriguez, Laura; Perez Alonso, Nuria; Armero-Barranco, David; Lidon López Iborra, María; Damian, Escribano Tortosa; Pardo Rios, Manuel

2018-03-01

To determine the stress that is potentially produced in professional health workers due to a mass casualty incident (MCI) simulated exercise, and its relation to prior academic training and the role played in the simulation. Observational study of stress in a MCI. For this work, two MCI drills comprised of 40 victims each were conducted. Two randomized groups of 36 students each were created: Master's Students Group (MSG) and Undergraduate Student Group (USG). The role performed by each student (triage or sectorization) was assessed. The stress level was determined by prior and subsequent measurements of alpha-amylase (αA), HR, SBP and DBP. The percentage of victims that were correctly triaged was 88.6%, 91.84% for MSG and 83.76% for the USG (p=0.004). The basal αA was 97,107.50±72,182.67IU/L and the subsequent αA was 136,195.55±90,176.46±IU/L (pperformed the triage and those who performed sectorization but there were no differences between undergraduate and Masters' students. Conducting a simulated exercise caused stress in personnel involved in the MCI, with a greater impact on participants who performed triage, although it was not influenced by their prior academic level. The stress level in our case did not affect or determine the performance of acquired skills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploratory Study on the Impact of Information on Performance Psychology on Stress and Anxiety Levels of Brazilian Music Performers

Directory of Open Access Journals (Sweden)

Sonia Ray

2016-12-01

Full Text Available This paper examines the impact of information on psychology of music on Stress and Anxiety Levels of Brazilian students of music performance, both undergraduate and graduate, and cross information on their levels of stress and anxiety. It includes an investigation on curricular programs of Brazilian public universities based on previous investigation by the authors (RAY; et al, 2011. The main goals: 1 to investigate how much information Brazilian music performance students has access to access during their courses; and 2 to identify potential indicators of the impact this information may have on the levels of stress and anxiety in the performances of these students; Methodology:  Students from six Brazilian public universities were requested to fill out three forms: the Kenny Music Performance Anxiety Inventory (K-MPAI; the Inventory of Stress Symptoms LIPP and an additional form that investigated the participants routine for preparation to performance. Results: information on music performance psychology is only presented privately at teacher’s discretion. As compulsory classes have not been included in the curriculum, it was not possible to infer results on this subject. More than half of the participants (51,72% don’t present stress condition. Almost half of them (48,27% have some level of stress. All participants fit within some level of anxiety.

Apples and oranges: avoiding different priors in Bayesian DNA sequence analysis

Directory of Open Access Journals (Sweden)

Posch Stefan

2010-03-01

Full Text Available Abstract Background One of the challenges of bioinformatics remains the recognition of short signal sequences in genomic DNA such as donor or acceptor splice sites, splicing enhancers or silencers, translation initiation sites, transcription start sites, transcription factor binding sites, nucleosome binding sites, miRNA binding sites, or insulator binding sites. During the last decade, a wealth of algorithms for the recognition of such DNA sequences has been developed and compared with the goal of improving their performance and to deepen our understanding of the underlying cellular processes. Most of these algorithms are based on statistical models belonging to the family of Markov random fields such as position weight matrix models, weight array matrix models, Markov models of higher order, or moral Bayesian networks. While in many comparative studies different learning principles or different statistical models have been compared, the influence of choosing different prior distributions for the model parameters when using different learning principles has been overlooked, and possibly lead to questionable conclusions. Results With the goal of allowing direct comparisons of different learning principles for models from the family of Markov random fields based on the same a-priori information, we derive a generalization of the commonly-used product-Dirichlet prior. We find that the derived prior behaves like a Gaussian prior close to the maximum and like a Laplace prior in the far tails. In two case studies, we illustrate the utility of the derived prior for a direct comparison of different learning principles with different models for the recognition of binding sites of the transcription factor Sp1 and human donor splice sites. Conclusions We find that comparisons of different learning principles using the same a-priori information can lead to conclusions different from those of previous studies in which the effect resulting from different

Evaluation of the performance degradation at PAFC effect of electrolyte fill-level on electrode performance

Energy Technology Data Exchange (ETDEWEB)

Kitai, Takashi; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

1996-12-31

As a complimentary research project to the demonstration project of 5MW and 1MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY, with the objective of establishing an estimation method for the service life-time of the cell stacks. This work has been performed in the Basic Research Project, as part of that project on PAFC`s, selecting four subjects (Electrocatalysts degradation, Electrolyte fill-level, Cell material corrosion, Electrolyte loss) as the essential factors relating to the life-time. In this report, we will exhibit the effect of the electrolyte fill-level on the electrode performances.

The value of appropriate assessment prior to specialist referral in men with prostatic symptoms.

LENUS (Irish Health Repository)

Quinlan, M R

2012-02-01

BACKGROUND: Referrals to Urology OPD of men with a likely diagnosis of BPH are common. AIMS: To review referrals to OPD of men with lower urinary tract symptoms (LUTS) to establish how many could have been managed without specialist assessment. METHODS: We reviewed records of 200 male patients referred to OPD with LUTS. We assessed whether the referral source had performed digital rectal examination (DRE), International Prostate Symptom Score (IPSS), Bother Score or PSA level. RESULTS: 74% of patients were referred by GPs. In 31.5% of cases DRE was performed prior to referral. One GP had completed an IPSS, none a Bother Score. 96% had a PSA checked before OPD. Ultimately, 88.5% of our patients were diagnosed with BPH. CONCLUSIONS: With better pre-assessment in the form of DRE, IPSS and Bother Score, allied to a PSA check, many patients with LUTS could be managed in a primary care setting.

Own and Others' Prior Experiences Influence Children's Imitation of Causal Acts.

Science.gov (United States)

Williamson, Rebecca A; Meltzoff, Andrew N

2011-07-01

Young children learn from others' examples, and they do so selectively. We examine whether the efficacy of prior experiences influences children's imitation. Thirty-six-month-olds had initial experience on a causal learning task either by performing the task themselves or by watching an adult perform it. The nature of the experience was manipulated such that the actor had either an easy or a difficult experience completing the task. Next, a second adult demonstrated an innovative technique for completing it. Children who had a difficult first-person experience, and those who had witnessed another person having difficulty, were significantly more likely to adopt and imitate the adult's innovation than those who had or witnessed an easy experience. Children who observed another were also more likely to imitate than were those who had the initial experience themselves. Imitation is influenced by prior experience, both when it is obtained through one's own hands-on motor manipulation and when it derives from observing the acts of others.

Is free, prior and informed consent a form of corporate social responsibility?

NARCIS (Netherlands)

Rodhouse, Toyah; Vanclay, Frank

2016-01-01

International organizations are increasingly including Indigenous peoples' rights and the concept of Free, Prior and Informed Consent (FPIC) in their guidance documents, codes of conduct, and performance standards. Leading companies are adjusting their Corporate Social Responsibility (CSR) and

Trunk Stability, Trunk Strength and Sport Performance Level in Judo.

Directory of Open Access Journals (Sweden)

David Barbado

Full Text Available Although trunk muscle function has been suggested to be a determinant of judo performance, its contribution to high-level performance in this sport has been poorly studied. Therefore, several tests were used to assess the differences in trunk muscle function between 11 international and 14 national level judo practitioners (judokas. Trunk strength and endurance were assessed using isokinetic tests and core stability was assessed using two protocols: 1 sudden loading, to assess trunk responses to unexpected external perturbations; 2 stable and unstable sitting, to assess the participants' ability to control trunk balance. No differences between groups were found for trunk flexor isokinetic strength, trunk responses against lateral and posterior loading and trunk control while sitting. However, international level judokas showed significantly higher trunk extensor isokinetic strength (p <0.05 and lower trunk angular displacement after anterior trunk loading (p <0.05 than national level judokas. Few and low (r < 0.512 significant correlations were found between strength, endurance and stability parameters, which suggests that trunk strength and endurance are not limiting factors for trunk stability in competitive judokas. These results support the importance of trunk extensor strength and trunk stability against forward perturbations in elite judo performance.

Rapid sampling of molecular motions with prior information constraints.

Science.gov (United States)

Raveh, Barak; Enosh, Angela; Schueler-Furman, Ora; Halperin, Dan

2009-02-01

Proteins are active, flexible machines that perform a range of different functions. Innovative experimental approaches may now provide limited partial information about conformational changes along motion pathways of proteins. There is therefore a need for computational approaches that can efficiently incorporate prior information into motion prediction schemes. In this paper, we present PathRover, a general setup designed for the integration of prior information into the motion planning algorithm of rapidly exploring random trees (RRT). Each suggested motion pathway comprises a sequence of low-energy clash-free conformations that satisfy an arbitrary number of prior information constraints. These constraints can be derived from experimental data or from expert intuition about the motion. The incorporation of prior information is very straightforward and significantly narrows down the vast search in the typically high-dimensional conformational space, leading to dramatic reduction in running time. To allow the use of state-of-the-art energy functions and conformational sampling, we have integrated this framework into Rosetta, an accurate protocol for diverse types of structural modeling. The suggested framework can serve as an effective complementary tool for molecular dynamics, Normal Mode Analysis, and other prevalent techniques for predicting motion in proteins. We applied our framework to three different model systems. We show that a limited set of experimentally motivated constraints may effectively bias the simulations toward diverse predicates in an outright fashion, from distance constraints to enforcement of loop closure. In particular, our analysis sheds light on mechanisms of protein domain swapping and on the role of different residues in the motion.

Rapid sampling of molecular motions with prior information constraints.

Directory of Open Access Journals (Sweden)

Barak Raveh

2009-02-01

Full Text Available Proteins are active, flexible machines that perform a range of different functions. Innovative experimental approaches may now provide limited partial information about conformational changes along motion pathways of proteins. There is therefore a need for computational approaches that can efficiently incorporate prior information into motion prediction schemes. In this paper, we present PathRover, a general setup designed for the integration of prior information into the motion planning algorithm of rapidly exploring random trees (RRT. Each suggested motion pathway comprises a sequence of low-energy clash-free conformations that satisfy an arbitrary number of prior information constraints. These constraints can be derived from experimental data or from expert intuition about the motion. The incorporation of prior information is very straightforward and significantly narrows down the vast search in the typically high-dimensional conformational space, leading to dramatic reduction in running time. To allow the use of state-of-the-art energy functions and conformational sampling, we have integrated this framework into Rosetta, an accurate protocol for diverse types of structural modeling. The suggested framework can serve as an effective complementary tool for molecular dynamics, Normal Mode Analysis, and other prevalent techniques for predicting motion in proteins. We applied our framework to three different model systems. We show that a limited set of experimentally motivated constraints may effectively bias the simulations toward diverse predicates in an outright fashion, from distance constraints to enforcement of loop closure. In particular, our analysis sheds light on mechanisms of protein domain swapping and on the role of different residues in the motion.

The Alpha-defensin Test for Periprosthetic Joint Infections Is Not Affected by Prior Antibiotic Administration.

Science.gov (United States)

Shahi, Alisina; Parvizi, Javad; Kazarian, Gregory S; Higuera, Carlos; Frangiamore, Salvatore; Bingham, Joshua; Beauchamp, Christopher; Valle, Craig Della; Deirmengian, Carl

2016-07-01

Previous studies have demonstrated that the administration of antibiotics to patients before performing diagnostic testing for periprosthetic joint infection (PJI) can interfere with the accuracy of test results. Although a single-institution study has suggested that alpha-defensin maintains its concentration and sensitivity even after antibiotic treatment, this has not yet been demonstrated in a larger multiinstitutional study. (1) For the evaluation of PJI, is prior antibiotic administration associated with decreased alpha-defensin levels? (2) When prior antibiotics are given, is alpha-defensin a better screening test for PJI than the traditional tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], fluid white blood cells, fluid polymorphonuclear cells [PMNs], and fluid culture)? This retrospective study included data from 106 hip and knee arthroplasties with Musculoskeletal Infection Society-defined PJI from four centers. Of the 106 patients in this study, 30 (28%) were treated with antibiotics for PJI before diagnostic workup (ABX group), and 76 (72%) were not treated before the diagnostic workup (NO-ABX group). There were no differences in age, sex, joint, culture-negative rate, or bacteriology between groups. The patients in the ABX group had antibiotics initiated by physicians who commenced care before assessment for PJI by the treating surgeon's service. We compared the alpha-defensin levels and sensitivity between the ABX and NO-ABX groups. Additionally, the sensitivity of the alpha-defensin test was compared to that of traditional tests for PJI among patients on antibiotics. The administration of antibiotics before performing the alpha-defensin test for PJI was not associated with a decreased median alpha-defensin level (ABX group, median 4.2 [range, 1.79-12.8 S/CO] versus NO-ABX, median 4.9 [range, 0.5-16.8 S/CO], difference of medians: 0.68 S/CO [95% confidence interval {CI}, -0.98 to 1.26], p = 0.451). Furthermore, the alpha

Sex-specific neural activity when resolving cognitive interference in individuals with or without prior internalizing disorders.

Science.gov (United States)

Wang, Zhishun; Jacobs, Rachel H; Marsh, Rachel; Horga, Guillermo; Qiao, Jianping; Warner, Virginia; Weissman, Myrna M; Peterson, Bradley S

2016-03-30

The processing of cognitive interference is a self-regulatory capacity that is impaired in persons with internalizing disorders. This investigation was to assess sex differences in the neural correlates of cognitive interference in individuals with and without an illness history of an internalizing disorder. We compared functional magnetic resonance imaging blood-oxygenation-level-dependent responses in both males (n=63) and females (n=80) with and without this illness history during performance of the Simon task. Females deactivated superior frontal gyrus, inferior parietal lobe, and posterior cingulate cortex to a greater extent than males. Females with a prior history of internalizing disorder also deactivated these regions more compared to males with that history, and they additionally demonstrated greater activation of right inferior frontal gyrus. These group differences were represented in a significant sex-by-illness interaction in these regions. These deactivated regions compose a task-negative or default mode network, whereas the inferior frontal gyrus usually activates when performing an attention-demanding task and is a key component of a task-positive network. Our findings suggest that a prior history of internalizing disorders disproportionately influences functioning of the default mode network and is associated with an accompanying activation of the task-positive network in females during the resolution of cognitive interference. Copyright © 2016. Published by Elsevier Ireland Ltd.

CMS High Level Trigger Timing Measurements

International Nuclear Information System (INIS)

Richardson, Clint

2015-01-01

The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented. (paper)

Self-regulation of learning and performance level of elite youth soccer players

NARCIS (Netherlands)

Toering, Tynke; Elferink-Gemser, Marije T.; Jordet, Geir; Pepping, Gert-Jan; Visscher, Chris

2012-01-01

This study examined the relationship between self-regulated learning and performance level of 256 elite youth soccer players aged 12 to 17 years (M-age = 14.2; SD = 1.2). As relative age may affect this relationship through its association with maturation, experience, and performance level, we

Prior knowledge in recalling arguments in bioethical dilemmas

Directory of Open Access Journals (Sweden)

Hiemke Katharina Schmidt

2015-09-01

Full Text Available Prior knowledge is known to facilitate learning new information. Normally in studies confirming this outcome the relationship between prior knowledge and the topic to be learned is obvious: the information to be acquired is part of the domain or topic to which the prior knowledge belongs. This raises the question as to whether prior knowledge of various domains facilitates recalling information. In this study 79 eleventh-grade students completed a questionnaire on their prior knowledge of seven different domains related to the bioethical dilemma of prenatal diagnostics. The students read a text containing arguments for and arguments against prenatal diagnostics. After one week and again 12 weeks later they were asked to write down all the arguments they remembered. Prior knowledge helped them recall the arguments one week (r = .350 and 12 weeks (r = .316 later. Prior knowledge of three of the seven domains significantly helped them recall the arguments one week later (correlations between r = .194 to r = .394. Partial correlations with interest as a control item revealed that interest did not explain the relationship between prior knowledge and recall. Prior knowledge of different domains jointly supports the recall of arguments related to bioethical topics.

Employee performance appraisal and productivity levels in selected ...

African Journals Online (AJOL)

The focus of this study was on performance appraisal of academic staff of Universities in Nigeria and their productivity levels. The prime problem that necessitated this study was to examine the effectiveness of the subjective methods used in appraising qualitative work attributes of the employees and to assess the extent to ...

Prior adversities predict posttraumatic stress reactions in adolescents following the Oslo Terror events 2011

Science.gov (United States)

Nordanger, Dag Ø.; Breivik, Kyrre; Haugland, Bente Storm; Lehmann, Stine; Mæhle, Magne; Braarud, Hanne Cecilie; Hysing, Mari

2014-01-01

Background Former studies suggest that prior exposure to adverse experiences such as violence or sexual abuse increases vulnerability to posttraumatic stress reactions in victims of subsequent trauma. However, little is known about how such a history affects responses to terror in the general adolescent population. Objective To explore the role of prior exposure to adverse experiences as risk factors for posttraumatic stress reactions to the Oslo Terror events. Method We used data from 10,220 high school students in a large cross-sectional survey of adolescents in Norway that took place seven months after the Oslo Terror events. Prior exposure assessed was: direct exposure to violence, witnessing of violence, and unwanted sexual acts. We explored how these prior adversities interact with well-established risk factors such as proximity to the events, perceived life threat during the terror events, and gender. Results All types of prior exposure as well as the other risk factors were associated with terror-related posttraumatic stress reactions. The effects of prior adversities were, although small, independent of adolescents’ proximity to the terror events. Among prior adversities, only the effect of direct exposure to violence was moderated by perceived life threat. Exposure to prior adversities increased the risk of posttraumatic stress reactions equally for both genders, but proximity to the terror events and perceived life threat increased the risk more in females. Conclusions Terror events can have a more destabilizing impact on victims of prior adversities, independent of their level of exposure. The findings may be relevant to mental health workers and others providing post-trauma health care. PMID:24872862

Prior adversities predict posttraumatic stress reactions in adolescents following the Oslo Terror events 2011.

Science.gov (United States)

Nordanger, Dag Ø; Breivik, Kyrre; Haugland, Bente Storm; Lehmann, Stine; Mæhle, Magne; Braarud, Hanne Cecilie; Hysing, Mari

2014-01-01

Former studies suggest that prior exposure to adverse experiences such as violence or sexual abuse increases vulnerability to posttraumatic stress reactions in victims of subsequent trauma. However, little is known about how such a history affects responses to terror in the general adolescent population. To explore the role of prior exposure to adverse experiences as risk factors for posttraumatic stress reactions to the Oslo Terror events. We used data from 10,220 high school students in a large cross-sectional survey of adolescents in Norway that took place seven months after the Oslo Terror events. Prior exposure assessed was: direct exposure to violence, witnessing of violence, and unwanted sexual acts. We explored how these prior adversities interact with well-established risk factors such as proximity to the events, perceived life threat during the terror events, and gender. All types of prior exposure as well as the other risk factors were associated with terror-related posttraumatic stress reactions. The effects of prior adversities were, although small, independent of adolescents' proximity to the terror events. Among prior adversities, only the effect of direct exposure to violence was moderated by perceived life threat. Exposure to prior adversities increased the risk of posttraumatic stress reactions equally for both genders, but proximity to the terror events and perceived life threat increased the risk more in females. Terror events can have a more destabilizing impact on victims of prior adversities, independent of their level of exposure. The findings may be relevant to mental health workers and others providing post-trauma health care.

System-level techniques for analog performance enhancement

CERN Document Server

Song, Bang-Sup

2016-01-01

This book shows readers to avoid common mistakes in circuit design, and presents classic circuit concepts and design approaches from the transistor to the system levels. The discussion is geared to be accessible and optimized for practical designers who want to learn to create circuits without simulations. Topic by topic, the author guides designers to learn the classic analog design skills by understanding the basic electronics principles correctly, and further prepares them to feel confident in designing high-performance, state-of-the art CMOS analog systems. This book combines and presents all in-depth necessary information to perform various design tasks so that readers can grasp essential material, without reading through the entire book. This top-down approach helps readers to build practical design expertise quickly, starting from their understanding of electronics fundamentals. .

Exercise Performance of Sea-Level Residents at 4300 m After 6 Days at 2200 m

Science.gov (United States)

2009-11-01

commercially available energy bars and fruit juice (food composition 5 510 kcal, 14 gm fat, 65 gm carbohydrate, 32 gm protein) at 1 to 2 h prior to the...Intermittent altitude exposures improve muscular performance at 4300 m . J Appl Physiol 2003 ; 95 : 1824 – 32 . 3. Beidleman BA, Muza SR...in volumes of blood, plasma and red cell in dehydration . J Appl Physiol 1974 ; 37 : 247 – 8 . 8. Evans WO, Robinson SM, Horstman DH

Clinical utility of carotid duplex ultrasound prior to cardiac surgery.

Science.gov (United States)

Lin, Judith C; Kabbani, Loay S; Peterson, Edward L; Masabni, Khalil; Morgan, Jeffrey A; Brooks, Sara; Wertella, Kathleen P; Paone, Gaetano

2016-03-01

Clinical utility and cost-effectiveness of carotid duplex examination prior to cardiac surgery have been questioned by the multidisciplinary committee creating the 2012 Appropriate Use Criteria for Peripheral Vascular Laboratory Testing. We report the clinical outcomes and postoperative neurologic symptoms in patients who underwent carotid duplex ultrasound prior to open heart surgery at a tertiary institution. Using the combined databases from our clinical vascular laboratory and the Society of Thoracic Surgery, a retrospective analysis of all patients who underwent carotid duplex ultrasound within 13 months prior to open heart surgery from March 2005 to March 2013 was performed. The outcomes between those who underwent carotid duplex scanning (group A) and those who did not (group B) were compared. Among 3233 patients in the cohort who underwent cardiac surgery, 515 (15.9%) patients underwent a carotid duplex ultrasound preoperatively, and 2718 patients did not (84.1%). Among the patients who underwent carotid screening vs no screening, there was no statistically significant difference in the risk factors of cerebrovascular disease (10.9% vs 12.7%; P = .26), prior stroke (8.2% vs 7.2%; P = .41), and prior transient ischemic attack (2.9% vs 3.3%; P = .24). For those undergoing isolated coronary artery bypass grafting (CABG), 306 (17.8%) of 1723 patients underwent preoperative carotid duplex ultrasound. Among patients who had carotid screening prior to CABG, the incidence of carotid disease was low: 249 (81.4%) had minimal or mild stenosis (duplex scanning and those who did not. Primary outcomes of patients who underwent open heart surgery also showed no difference in the perioperative mortality (5.1% vs 6.9%; P = .14) and stroke (2.6% vs 2.4%; P = .85) between patients undergoing preoperative duplex scanning and those who did not. Operative intervention of severe carotid stenosis prior to isolated CABG occurred in 2 of the 17 patients (11.8%) identified who

Performance of the Public Expenditure Management at Local Level in Romania

Directory of Open Access Journals (Sweden)

Ani MATEI

2008-06-01

Full Text Available The current paper aims to analyze the performance of the public expenditure management based on the decrease of the administrative costs. The paper is grounded on the following premises: (1 Romania as an EU Member State is under a continuous process to harmonize its legislation with the EU legislation. (2 The integration of Romania in EU in 2007 has determined a significant change in the administrative expenditure amount. (3 Strengthening local autonomy through the decentralization and the devolution processes emphasizes clearer the need for improving the performance of the expenditure management at local level. (4 Internal order, flows of communication and transfer, synergy of the governance system assume administrative expenditure that can be determined. (5 The performance of public organizations in managing local governance issues depends directly also on the administrative expenditure level**. [** Paper accepted to be presented at the Fourth TransAtlantic Dialogue “The Status of Inter-Governmental Relations and Multi-Level Governance in Europe and the US”, Workshop 5: “Performance measurement and accountability in IGR-MLG”.

Prior failed ipsilateral percutaneous endovascular intervention in patients with critical limb ischemia predicts poor outcome after lower extremity bypass

Science.gov (United States)

Nolan, Brian W.; De Martino, Randall R.; Stone, David H.; Schanzer, Andres; Goodney, Philip P.; Walsh, Daniel W.; Cronenwett, Jack L.

2017-01-01

Background Although open surgical bypass remains the standard revascularization strategy for patients with critical limb ischemia (CLI), many centers now perform peripheral endovascular intervention (PVI) as the first-line treatment for these patients. We sought to determine the effect of a prior ipsilateral PVI (iPVI) on the outcome of subsequent lower extremity bypass (LEB) in patients with CLI. Methods A retrospective cohort analysis of all patients undergoing infrainguinal LEB between 2003 and 2009 within hospitals comprising the Vascular Study Group of New England (VSGNE) was performed. Primary study endpoints were major amputation and graft occlusion at 1 year postoperatively. Secondary outcomes included in-hospital major adverse events (MAE), 1-year mortality, and composite 1-year major adverse limb events (MALE). Event rates were determined using life table analyses and comparisons were performed using the log-rank test. Multivariate predictors were determined using a Cox proportional hazards model with multilevel hierarchical adjustment. Results Of 1880 LEBs performed, 32% (n = 603) had a prior infrainguinal revascularization procedure (iPVI, 7%; ipsilateral bypass, 15%; contralateral PVI, 3%; contralateral bypass, 17%). Patients with prior iPVI, compared with those without a prior iPVI, were more likely to be women (32 vs 41%; P = .04), less likely to have tissue loss (52% vs 63%; P = .02), more likely to require arm vein conduit (16% vs 5%; P = .001), and more likely to be on statin (71% vs 54%; P = .01) and beta blocker therapy (92% vs 81%; P = .01) at the time of their bypass procedure. Other demographic factors were similar between these groups. Prior PVI or bypass did not alter 30-day MAE and 1-year mortality after the index bypass. In contrast, 1-year major amputation and 1-year graft occlusion rates were significantly higher in patients who had prior iPVI than those without (31% vs 20%; P = .046 and 28% vs 18%; P = .009), similar to patients who

Characterization of statistical prior image constrained compressed sensing (PICCS): II. Application to dose reduction

International Nuclear Information System (INIS)

Lauzier, Pascal Thériault; Chen Guanghong

2013-01-01

Purpose: The ionizing radiation imparted to patients during computed tomography exams is raising concerns. This paper studies the performance of a scheme called dose reduction using prior image constrained compressed sensing (DR-PICCS). The purpose of this study is to characterize the effects of a statistical model of x-ray detection in the DR-PICCS framework and its impact on spatial resolution. Methods: Both numerical simulations with known ground truth and in vivo animal dataset were used in this study. In numerical simulations, a phantom was simulated with Poisson noise and with varying levels of eccentricity. Both the conventional filtered backprojection (FBP) and the PICCS algorithms were used to reconstruct images. In PICCS reconstructions, the prior image was generated using two different denoising methods: a simple Gaussian blur and a more advanced diffusion filter. Due to the lack of shift-invariance in nonlinear image reconstruction such as the one studied in this paper, the concept of local spatial resolution was used to study the sharpness of a reconstructed image. Specifically, a directional metric of image sharpness, the so-called pseudopoint spread function (pseudo-PSF), was employed to investigate local spatial resolution. Results: In the numerical studies, the pseudo-PSF was reduced from twice the voxel width in the prior image down to less than 1.1 times the voxel width in DR-PICCS reconstructions when the statistical model was not included. At the same noise level, when statistical weighting was used, the pseudo-PSF width in DR-PICCS reconstructed images varied between 1.5 and 0.75 times the voxel width depending on the direction along which it was measured. However, this anisotropy was largely eliminated when the prior image was generated using diffusion filtering; the pseudo-PSF width was reduced to below one voxel width in that case. In the in vivo study, a fourfold improvement in CNR was achieved while qualitatively maintaining sharpness

Brain Magnetic Resonance Immediately Prior To Surgery In Single Ventricles and Surgical Postponement

Science.gov (United States)

Fogel, Mark A.; Pawlowski, Tom; Schwab, Peter J.; Nicolson, Susan C.; Montenegro, Lisa M.; Berenstein, Laura Diaz; Spray, Thomas L.; Gaynor, J William; Fuller, Stephanie; Keller, Marc S.; Harris, Matthew A.; Whitehead, Kevin K.; Vossough, Arastoo; Licht, Daniel J.

2014-01-01

Background Single ventricle patients undergoing surgical reconstruction experience a high rate of brain injury; incidental findings on pre-operative brain scans may result in safety considerations involving hemorrhage extension during cardiopulmonary bypass that result in surgical postponement. Methods Single ventricle patients were studied with brain scans immediately preoperatively as part of a National Institute of Health study and were reviewed by neuroradiology immediately prior to cardiopulmonary bypass. Results One hundred and thirty four consecutive subjects recruited into the project were studied: 33 prior to stage I (3.7±1.8 days), 34 prior to bidirectional Glenn (5.8±3.5 months) and 67 prior to Fontan (3.3±1.1 years). Six (4.5%) surgeries were postponed because of concerning imaging findings on brain MRI; 2 prior to stage I, 3 prior to bidirectional Glenn and 1 prior to Fontan. Five were due to unexpected incidental findings of acute intracranial hemorrhage and one due to diffuse cerebellar cytotoxic edema; none who proceeded to surgery had these lesions. Prematurity as well as genetic syndromes were not present in any with postponed surgery. Four of 4 prior to bidirectional Glenn/Fontan with surgical delays had hypoplastic left heart syndrome compared with 44/97 who did not (P=0.048). After observation and follow up, all eventually had successful surgeries with bypass. Conclusion Preoperative brain MRI performed in children with single ventricles disclosed injuries in 4.5% leading to surgical delay; hemorrhagic lesions were most common and raised concerns for extension during surgery. The true risk of progression and need for delay of surgery due to heparinization associated with these lesions remains uncertain. PMID:25149046

GABA level, gamma oscillation, and working memory performance in schizophrenia.

Science.gov (United States)

Chen, Chi-Ming A; Stanford, Arielle D; Mao, Xiangling; Abi-Dargham, Anissa; Shungu, Dikoma C; Lisanby, Sarah H; Schroeder, Charles E; Kegeles, Lawrence S

2014-01-01

A relationship between working memory impairment, disordered neuronal oscillations, and abnormal prefrontal GABA function has been hypothesized in schizophrenia; however, in vivo GABA measurements and gamma band neural synchrony have not yet been compared in schizophrenia. This case-control pilot study (N = 24) compared baseline and working memory task-induced neuronal oscillations acquired with high-density electroencephalograms (EEGs) to GABA levels measured in vivo with magnetic resonance spectroscopy. Working memory performance, baseline GABA level in the left dorsolateral prefrontal cortex (DLPFC), and measures of gamma oscillations from EEGs at baseline and during a working memory task were obtained. A major limitation of this study is a relatively small sample size for several analyses due to the integration of diverse methodologies and participant compliance. Working memory performance was significantly lower for patients than for controls. During the working memory task, patients (n = 7) had significantly lower amplitudes in gamma oscillations than controls (n = 9). However, both at rest and across working memory stages, there were significant correlations between gamma oscillation amplitude and left DLPFC GABA level. Peak gamma frequency during the encoding stage of the working memory task (n = 16) significantly correlated with GABA level and working memory performance. Despite gamma band amplitude deficits in patients across working memory stages, both baseline and working memory-induced gamma oscillations showed strong dependence on baseline GABA levels in patients and controls. These findings suggest a critical role for GABA function in gamma band oscillations, even under conditions of system and cognitive impairments as seen in schizophrenia.

Teaching Groups as Foci for Evaluating Performance in Cost-Effectiveness of GCE Advanced Level Provision: Some Practical Methodological Innovations.

Science.gov (United States)

Fielding, Antony

2002-01-01

Analyzes subject teaching-group effectiveness in English and Welsh General Certification of Education (GCE) Advanced Level prior to a linking to resources; suggests cross-classified multilevel models with weighted random effects for disentangling student, group, and teacher effects; finds that teacher effects are considerable, but cannot find…

Prior image constrained image reconstruction in emerging computed tomography applications

Science.gov (United States)

Brunner, Stephen T.

Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

Disrupted topological organization of brain structural network associated with prior overt hepatic encephalopathy in cirrhotic patients

Energy Technology Data Exchange (ETDEWEB)

Chen, Hua-Jun [Fujian Medical University Union Hospital, Department of Radiology, Fuzhou (China); The First Affiliated Hospital of Nanjing Medical University, Department of Radiology, Nanjing (China); Shi, Hai-Bin [The First Affiliated Hospital of Nanjing Medical University, Department of Radiology, Nanjing (China); Jiang, Long-Feng [The First Affiliated Hospital of Nanjing Medical University, Department of Infectious Diseases, Nanjing (China); Li, Lan [Fujian Medical University Union Hospital, Department of Radiology, Fuzhou (China); Chen, Rong [University of Maryland School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Baltimore, MD (United States); Beijing Institute of Technology, Advanced Innovation Center for Intelligent Robots and Systems, Beijing (China)

2018-01-15

To investigate structural brain connectome alterations in cirrhotic patients with prior overt hepatic encephalopathy (OHE). Seventeen cirrhotic patients with prior OHE (prior-OHE), 18 cirrhotic patients without prior OHE (non-prior-OHE) and 18 healthy controls (HC) underwent diffusion tensor imaging. Neurocognitive functioning was assessed with Psychometric Hepatic Encephalopathy Score (PHES). Using a probabilistic fibre tracking approach, we depicted the whole-brain structural network as a connectivity matrix of 90 regions (derived from the Automated Anatomic Labeling atlas). Graph theory-based analyses were performed to analyse topological properties of the brain network. The analysis of variance showed significant group effects on several topological properties, including network strength, global efficiency and local efficiency. A progressive decrease trend for these metrics was found from non-prior-OHE to prior-OHE, compared with HC. Among the three groups, the regions with altered nodal efficiency were mainly distributed in the frontal and occipital cortices, paralimbic system and subcortical regions. The topological metrics, such as network strength and global efficiency, were correlated with PHES among cirrhotic patients. The cirrhotic patients developed structural brain connectome alterations; this is aggravated by prior OHE episode. Disrupted topological organization of the brain structural network may account for cognitive impairments related to prior OHE. (orig.)

Disrupted topological organization of brain structural network associated with prior overt hepatic encephalopathy in cirrhotic patients

International Nuclear Information System (INIS)

Chen, Hua-Jun; Shi, Hai-Bin; Jiang, Long-Feng; Li, Lan; Chen, Rong

2018-01-01

To investigate structural brain connectome alterations in cirrhotic patients with prior overt hepatic encephalopathy (OHE). Seventeen cirrhotic patients with prior OHE (prior-OHE), 18 cirrhotic patients without prior OHE (non-prior-OHE) and 18 healthy controls (HC) underwent diffusion tensor imaging. Neurocognitive functioning was assessed with Psychometric Hepatic Encephalopathy Score (PHES). Using a probabilistic fibre tracking approach, we depicted the whole-brain structural network as a connectivity matrix of 90 regions (derived from the Automated Anatomic Labeling atlas). Graph theory-based analyses were performed to analyse topological properties of the brain network. The analysis of variance showed significant group effects on several topological properties, including network strength, global efficiency and local efficiency. A progressive decrease trend for these metrics was found from non-prior-OHE to prior-OHE, compared with HC. Among the three groups, the regions with altered nodal efficiency were mainly distributed in the frontal and occipital cortices, paralimbic system and subcortical regions. The topological metrics, such as network strength and global efficiency, were correlated with PHES among cirrhotic patients. The cirrhotic patients developed structural brain connectome alterations; this is aggravated by prior OHE episode. Disrupted topological organization of the brain structural network may account for cognitive impairments related to prior OHE. (orig.)

Lawrence Livermore National Laboratory low-level waste systems performance assessment

International Nuclear Information System (INIS)

1990-11-01

This Low-Level Radioactive Waste (LLW) Systems Performance Assessment (PA) presents a systematic analysis of the potential risks posed by the Lawrence Livermore National Laboratory (LLNL) waste management system. Potential risks to the public and environment are compared to established performance objectives as required by DOE Order 5820.2A. The report determines the associated maximum individual committed effective dose equivalent (CEDE) to a member of the public from LLW and mixed waste. A maximum annual CEDE of 0.01 mrem could result from routine radioactive liquid effluents. A maximum annual CEDE of 0.003 mrem could result from routine radioactive gaseous effluents. No other pathways for radiation exposure of the public indicated detectable levels of exposure. The dose rate, monitoring, and waste acceptance performance objectives were found to be adequately addressed by the LLNL Program. 88 refs., 3 figs., 17 tabs

A Bayesian approach to PET reconstruction using image-modeling Gibbs priors: Implementation and comparison

International Nuclear Information System (INIS)

Chan, M.T.; Herman, G.T.; Levitan, E.

1996-01-01

We demonstrate that (i) classical methods of image reconstruction from projections can be improved upon by considering the output of such a method as a distorted version of the original image and applying a Bayesian approach to estimate from it the original image (based on a model of distortion and on a Gibbs distribution as the prior) and (ii) by selecting an open-quotes image-modelingclose quotes prior distribution (i.e., one which is such that it is likely that a random sample from it shares important characteristics of the images of the application area) one can improve over another Gibbs prior formulated using only pairwise interactions. We illustrate our approach using simulated Positron Emission Tomography (PET) data from realistic brain phantoms. Since algorithm performance ultimately depends on the diagnostic task being performed. we examine a number of different medically relevant figures of merit to give a fair comparison. Based on a training-and-testing evaluation strategy, we demonstrate that statistically significant improvements can be obtained using the proposed approach

Prior Knowledge Improves Decoding of Finger Flexion from Electrocorticographic (ECoG Signals

Directory of Open Access Journals (Sweden)

Zuoguan eWang

2011-11-01

Full Text Available Brain-computer interfaces (BCIs use brain signals to convey a user's intent. Some BCI approaches begin by decoding kinematic parameters of movements from brain signals, and then proceed to using these signals, in absence of movements, to allow a user to control an output. Recent results have shown that electrocorticographic (ECoG recordings from the surface of the brain in humans can give information about kinematic parameters (eg{} hand velocity or finger flexion. The decoding approaches in these studies usually employed classical classification/regression algorithms that derive a linear mapping between brain signals and outputs. However, they typically only incorporate little prior information about the target movement parameter. In this paper, we incorporate prior knowledge using a Bayesian decoding method, and use it to decode finger flexion from ECoG signals. Specifically, we exploit the anatomic constraints and dynamic constraints that govern finger flexion and incorporate these constraints in the construction, structure, and the probabilistic functions of the prior model of a switched non-parametric dynamic system (SNDS. Given a measurement model resulting from a traditional linear regression method, we decoded finger flexion using posterior estimation that combined the prior and measurement models. Our results show that the application of the Bayesian decoding model, which incorporates prior knowledge, improves decoding performance compared to the application of a linear regression model, which does not incorporate prior knowledge. Thus, the results presented in this paper may ultimately lead to neurally controlled hand prostheses with full fine-grained finger articulation.

Prior elicitation and Bayesian analysis of the Steroids for Corneal Ulcers Trial.

Science.gov (United States)

See, Craig W; Srinivasan, Muthiah; Saravanan, Somu; Oldenburg, Catherine E; Esterberg, Elizabeth J; Ray, Kathryn J; Glaser, Tanya S; Tu, Elmer Y; Zegans, Michael E; McLeod, Stephen D; Acharya, Nisha R; Lietman, Thomas M

2012-12-01

To elicit expert opinion on the use of adjunctive corticosteroid therapy in bacterial corneal ulcers. To perform a Bayesian analysis of the Steroids for Corneal Ulcers Trial (SCUT), using expert opinion as a prior probability. The SCUT was a placebo-controlled trial assessing visual outcomes in patients receiving topical corticosteroids or placebo as adjunctive therapy for bacterial keratitis. Questionnaires were conducted at scientific meetings in India and North America to gauge expert consensus on the perceived benefit of corticosteroids as adjunct treatment. Bayesian analysis, using the questionnaire data as a prior probability and the primary outcome of SCUT as a likelihood, was performed. For comparison, an additional Bayesian analysis was performed using the results of the SCUT pilot study as a prior distribution. Indian respondents believed there to be a 1.21 Snellen line improvement, and North American respondents believed there to be a 1.24 line improvement with corticosteroid therapy. The SCUT primary outcome found a non-significant 0.09 Snellen line benefit with corticosteroid treatment. The results of the Bayesian analysis estimated a slightly greater benefit than did the SCUT primary analysis (0.19 lines verses 0.09 lines). Indian and North American experts had similar expectations on the effectiveness of corticosteroids in bacterial corneal ulcers; that corticosteroids would markedly improve visual outcomes. Bayesian analysis produced results very similar to those produced by the SCUT primary analysis. The similarity in result is likely due to the large sample size of SCUT and helps validate the results of SCUT.

Assessment of U.S. firm-level climate change performance and strategy

International Nuclear Information System (INIS)

Yu, Yu; Wang, Derek D.; Li, Shanling; Shi, Qinfen

2016-01-01

Climate change is becoming an increasingly critical concern for human society. While there has been a great deal of research on climate change performance at the country/region level, our research focuses on the study of firm-level environmental efficiency as a proxy for firms' climate change management. Using a unique data set on U.S. S&P 500 firms for the period 2012–2013 and DEA slack-based models, we obtain firms' environmental efficiencies in six sectors. The results show significant performance dispersions both across and within the sectors. We highlight each sector's pros and cons in the environmental performance and propose guidelines for policy makers to further improve climate change performance. We also evaluate firms' operational performance and propose a unified performance measure by integrating operational and environmental efficiencies. Overall, we find there is no significant relationship between operational and environmental efficiencies in any of the six industrial sectors under study. The unified performance measures are more driven by the environmental efficiency than the operational efficiency. - Highlights: •U.S. firms have large variations in climate performance across/within the sectors. •Relationship between operational and climate performances is not significant. •The operational and climate performances can be captured in a unified measure.

The Power of Individual-level Drivers of Inventive Performance

DEFF Research Database (Denmark)

Zwick, Thomas; Frosch, Katharina; Hoisl, Karin

2017-01-01

(KSAO) model. We link survey information spanning the inventors’ entire careers and psychometric test evidence with patent history data for more than 1000 inventors. We also control for variables that have traditionally been used in studies of inventive performance including inventor age, applicant type......, technology, patent, and time information. We show that educational level, skills acquired during the career, personality traits, career motivation, cognitive ability, and cognitive problem-solving style are significantly related to inventive performance....

Prior adversities predict posttraumatic stress reactions in adolescents following the Oslo Terror events 2011

Directory of Open Access Journals (Sweden)

Dag Ø. Nordanger

2014-05-01

Full Text Available Background: Former studies suggest that prior exposure to adverse experiences such as violence or sexual abuse increases vulnerability to posttraumatic stress reactions in victims of subsequent trauma. However, little is known about how such a history affects responses to terror in the general adolescent population. Objective: To explore the role of prior exposure to adverse experiences as risk factors for posttraumatic stress reactions to the Oslo Terror events. Method: We used data from 10,220 high school students in a large cross-sectional survey of adolescents in Norway that took place seven months after the Oslo Terror events. Prior exposure assessed was: direct exposure to violence, witnessing of violence, and unwanted sexual acts. We explored how these prior adversities interact with well-established risk factors such as proximity to the events, perceived life threat during the terror events, and gender. Results: All types of prior exposure as well as the other risk factors were associated with terror-related posttraumatic stress reactions. The effects of prior adversities were, although small, independent of adolescents’ proximity to the terror events. Among prior adversities, only the effect of direct exposure to violence was moderated by perceived life threat. Exposure to prior adversities increased the risk of posttraumatic stress reactions equally for both genders, but proximity to the terror events and perceived life threat increased the risk more in females. Conclusions: Terror events can have a more destabilizing impact on victims of prior adversities, independent of their level of exposure. The findings may be relevant to mental health workers and others providing post-trauma health care.

Is math anxiety in the secondary classroom limiting physics mastery? A study of math anxiety and physics performance

Science.gov (United States)

Mercer, Gary J.

This quantitative study examined the relationship between secondary students with math anxiety and physics performance in an inquiry-based constructivist classroom. The Revised Math Anxiety Rating Scale was used to evaluate math anxiety levels. The results were then compared to the performance on a physics standardized final examination. A simple correlation was performed, followed by a multivariate regression analysis to examine effects based on gender and prior math background. The correlation showed statistical significance between math anxiety and physics performance. The regression analysis showed statistical significance for math anxiety, physics performance, and prior math background, but did not show statistical significance for math anxiety, physics performance, and gender.

Total Variability Modeling using Source-specific Priors

DEFF Research Database (Denmark)

Shepstone, Sven Ewan; Lee, Kong Aik; Li, Haizhou

2016-01-01

sequence of an utterance. In both cases the prior for the latent variable is assumed to be non-informative, since for homogeneous datasets there is no gain in generality in using an informative prior. This work shows in the heterogeneous case, that using informative priors for com- puting the posterior......, can lead to favorable results. We focus on modeling the priors using minimum divergence criterion or fac- tor analysis techniques. Tests on the NIST 2008 and 2010 Speaker Recognition Evaluation (SRE) dataset show that our proposed method beats four baselines: For i-vector extraction using an already...... trained matrix, for the short2-short3 task in SRE’08, five out of eight female and four out of eight male common conditions, were improved. For the core-extended task in SRE’10, four out of nine female and six out of nine male common conditions were improved. When incorporating prior information...

Quantitative Evidence Synthesis with Power Priors

NARCIS (Netherlands)

Rietbergen, C.|info:eu-repo/dai/nl/322847796

2016-01-01

The aim of this thesis is to provide the applied researcher with a practical approach for quantitative evidence synthesis using the conditional power prior that allows for subjective input and thereby provides an alternative tgbgo deal with the difficulties as- sociated with the joint power prior

A gross anatomy flipped classroom effects performance, retention, and higher-level thinking in lower performing students.

Science.gov (United States)

Day, Leslie J

2018-01-22

A flipped classroom is a growing pedagogy in higher education. Many research studies on the flipped classroom have focused on student outcomes, with the results being positive or inconclusive. A few studies have analyzed confounding variables, such as student's previous achievement, or the impact of a flipped classroom on long-term retention and knowledge transfer. In the present study, students in a Doctor of Physical Therapy program in a traditional style lecture of gross anatomy (n = 105) were compared to similar students in a flipped classroom (n = 112). Overall, students in the flipped anatomy classroom had an increase in semester average grades (P = 0.01) and performance on higher-level analytical questions (P flipped anatomy classroom performing at a higher level in kinesiology (P flipped anatomy class, outperformed their traditional anatomy class counterparts in anatomy semester grades (P flipped classroom may benefit lower performing student's knowledge acquisition and transfer to a greater degree than higher performing students. Future studies should explore the underlying reasons for improvement in lower performing students. Anat Sci Educ. © 2018 American Association of Anatomists. © 2018 American Association of Anatomists.

Analysis of Driver Evasive Maneuvering Prior to Intersection Crashes Using Event Data Recorders.

Science.gov (United States)

Scanlon, John M; Kusano, Kristofer D; Gabler, Hampton C

2015-01-01

Intersection crashes account for over 4,500 fatalities in the United States each year. Intersection Advanced Driver Assistance Systems (I-ADAS) are emerging vehicle-based active safety systems that have the potential to help drivers safely navigate across intersections and prevent intersection crashes and injuries. The performance of an I-ADAS is expected to be highly dependent upon driver evasive maneuvering prior to an intersection crash. Little has been published, however, on the detailed evasive kinematics followed by drivers prior to real-world intersection crashes. The objective of this study was to characterize the frequency, timing, and kinematics of driver evasive maneuvers prior to intersection crashes. Event data recorders (EDRs) downloaded from vehicles involved in intersection crashes were investigated as part of NASS-CDS years 2001 to 2013. A total of 135 EDRs with precrash vehicle speed and braking application were downloaded to investigate evasive braking. A smaller subset of 59 EDRs that collected vehicle yaw rate was additionally analyzed to investigate evasive steering. Each vehicle was assigned to one of 3 precrash movement classifiers (traveling through the intersection, completely stopped, or rolling stop) based on the vehicle's calculated acceleration and observed velocity profile. To ensure that any significant steering input observed was an attempted evasive maneuver, the analysis excluded vehicles at intersections that were turning, driving on a curved road, or performing a lane change. Braking application at the last EDR-recorded time point was assumed to indicate evasive braking. A vehicle yaw rate greater than 4° per second was assumed to indicate an evasive steering maneuver. Drivers executed crash avoidance maneuvers in four-fifths of intersection crashes. A more detailed analysis of evasive braking frequency by precrash maneuver revealed that drivers performing complete or rolling stops (61.3%) braked less often than drivers

Recruiting for Prior Service Market

Science.gov (United States)

2008-06-01

perceptions, expectations and issues for re-enlistment • Develop potential marketing and advertising tactics and strategies targeted to the defined...01 JUN 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Recruiting for Prior Service Market 5a. CONTRACT NUMBER 5b. GRANT...Command First Handshake to First Unit of Assignment An Army of One Proud to Be e e to Serve Recruiting for Prior Service Market MAJ Eric Givens / MAJ Brian

Level-1 E/Gamma performance on 2017 data

CERN Document Server

CMS Collaboration

2018-01-01

In $2017$, the LHC achieved an instantaneous luminosity of $2\\times10^{34}cm^{-2}s^{-1}$ with an average peak number of pile-up interactions of over $50$. This document includes studies of the performance of the CMS Level-1 Calorimeter Trigger for electrons and photons. The plots are made using the full dataset of $2017$ with $41.3$ $fb^{-1}$.

A performance assessment methodology for low-level radioactive waste disposal

International Nuclear Information System (INIS)

Derring, L.R.

1990-01-01

To demonstrate compliance with the performance objectives governing protection of the general population in 10 CFR 61.41, applicants for land disposal of low-level radioactive waste are required to conduct a pathways analysis, or quantitative evaluation of radionuclide release, transport through environmental media, and dose to man. The Nuclear Regulatory Commission staff defined a strategy and initiated a project at Sandia National Laboratories to develop a methodology for independently evaluating an applicant's analysis of postclosure performance. This performance assessment methodology was developed in five stages: identification of environmental pathways, ranking the significance of the pathways, identification and integration of models for pathway analyses, identification and selection of computer codes and techniques for the methodology, and implementation of the codes and documentation of the methodology. This paper summarizes the NRC approach for conducting evaluations of license applications for low-level radioactive waste facilities. 23 refs

Dietary protein level and performance of growing Baladi kids.

Science.gov (United States)

Abdelrahman, M M; Aljumaah, R S

2014-01-01

A study was conducted to evaluate the effect of feeding different levels of protein to black Baladi breed kids. Weanling Baladi kids (n=18; 75 to 90 days old) were selected and individually housed at our experimental farm. Kids were divided randomly to one of the three treatments for 12 weeks. The three dietary treatments were: T1: control ration, formulated according to NRC to cover the protein (level 1) and other nutrients requirements. T2: ration formulated to cover only 75% of protein (level 2) recommended by NRC. T3: control diet + 2.4 g undegradable methionine (Smartamine®)/day/kid (level 3). Feed intake, initial and monthly body weights were recorded. Blood samples were collected monthly and analyzed for metabolites and Co, Zn and Cu levels. Decreasing the dietary level of protein (T2) negatively affected (Pkids below the NRC requirements of protein negatively affect the growth performance and feed efficiency. The recommended protein level by NRC for growing kids cover the requirements of growing black Baladi kids for maximum growth and productivity.

GABA level, gamma oscillation, and working memory performance in schizophrenia

Directory of Open Access Journals (Sweden)

Chi-Ming A. Chen

2014-01-01

Full Text Available A relationship between working memory impairment, disordered neuronal oscillations, and abnormal prefrontal GABA function has been hypothesized in schizophrenia; however, in vivo GABA measurements and gamma band neural synchrony have not yet been compared in schizophrenia. This case–control pilot study (N = 24 compared baseline and working memory task-induced neuronal oscillations acquired with high-density electroencephalograms (EEGs to GABA levels measured in vivo with magnetic resonance spectroscopy. Working memory performance, baseline GABA level in the left dorsolateral prefrontal cortex (DLPFC, and measures of gamma oscillations from EEGs at baseline and during a working memory task were obtained. A major limitation of this study is a relatively small sample size for several analyses due to the integration of diverse methodologies and participant compliance. Working memory performance was significantly lower for patients than for controls. During the working memory task, patients (n = 7 had significantly lower amplitudes in gamma oscillations than controls (n = 9. However, both at rest and across working memory stages, there were significant correlations between gamma oscillation amplitude and left DLPFC GABA level. Peak gamma frequency during the encoding stage of the working memory task (n = 16 significantly correlated with GABA level and working memory performance. Despite gamma band amplitude deficits in patients across working memory stages, both baseline and working memory-induced gamma oscillations showed strong dependence on baseline GABA levels in patients and controls. These findings suggest a critical role for GABA function in gamma band oscillations, even under conditions of system and cognitive impairments as seen in schizophrenia.

Recolonization of group B Streptococcus (GBS) in women with prior GBS genital colonization in pregnancy.

Science.gov (United States)

Tam, Teresa; Bilinski, Ewa; Lombard, Emily

2012-10-01

The purpose of the study is to evaluate the incidence of women with prior GBS genital colonization who have recolonization in subsequent pregnancies. This is a retrospective, cohort study of patients with a prior GBS genital colonization in pregnancy and a subsequent pregnancy with a recorded GBS culture result, from January 2000 through June 2007. Documentation of GBS status was through GBS culture performed between 35 to 37 weeks gestation. Exclusion criteria included pregnancies with unknown GBS status, patients with GBS bacteriuria, women with a previous neonate with GBS disease and GBS finding prior to 35 weeks. Data was analyzed using SPSS 15.0. The sample proportion of subjects with GBS genital colonization and its confidence interval were computed to estimate the incidence rate. Logistic regression was performed to assess potential determinants of GBS colonization. Regression coefficients, odds ratios and associated confidence intervals, and p-values were reported, with significant results reported. There were 371 pregnancies that met the test criteria. There were 151 subsequent pregnancies with GBS genital colonization and 220 without GBS recolonization. The incidence of GBS recolonization on patients with prior GBS genital colonization was 40.7% (95% confidence interval 35.7-45.69%). The incidence rate for the sample was significantly larger than 30% (p recolonization in subsequent pregnancies.

Sleep Deprivation and Recovery Sleep Prior to a Noxious Inflammatory Insult Influence Characteristics and Duration of Pain.

Science.gov (United States)

Vanini, Giancarlo

2016-01-01

Insufficient sleep and chronic pain are public health epidemics. Sleep loss worsens pain and predicts the development of chronic pain. Whether previous, acute sleep loss and recovery sleep determine pain levels and duration remains poorly understood. This study tested whether acute sleep deprivation and recovery sleep prior to formalin injection alter post-injection pain levels and duration. Male Sprague-Dawley rats (n = 48) underwent sleep deprivation or ad libitum sleep for 9 hours. Thereafter, rats received a subcutaneous injection of formalin or saline into a hind paw. In the recovery sleep group, rats were allowed 24 h between sleep deprivation and the injection of formalin. Mechanical and thermal nociception were assessed using the von Frey test and Hargreaves' method. Nociceptive measures were performed at 1, 3, 7, 10, 14, 17 and 21 days post-injection. Formalin caused bilateral mechanical hypersensitivity (allodynia) that persisted for up to 21 days post-injection. Sleep deprivation significantly enhanced bilateral allodynia. There was a synergistic interaction when sleep deprivation preceded a formalin injection. Rats allowed a recovery sleep period prior to formalin injection developed allodynia only in the injected limb, with higher mechanical thresholds (less allodynia) and a shorter recovery period. There were no persistent changes in thermal nociception. The data suggest that acute sleep loss preceding an inflammatory insult enhances pain and can contribute to chronic pain. The results encourage studies in a model of surgical pain to test whether enhancing sleep reduces pain levels and duration. © 2016 Associated Professional Sleep Societies, LLC.

Bayesian Analysis of two Censored Shifted Gompertz Mixture Distributions using Informative and Noninformative Priors

Directory of Open Access Journals (Sweden)

Tabassum Naz Sindhu

2017-03-01

Full Text Available This study deals with Bayesian analysis of shifted Gompertz mixture model under type-I censored samples assuming both informative and noninformative priors. We have discussed the Bayesian estimation of parameters of shifted Gompertz mixture model under the uniform, and gamma priors assuming three loss functions. Further, some properties of the model with some graphs of the mixture density are discussed. These properties include Bayes estimators, posterior risks and reliability function under simulation scheme. Bayes estimates are obtained considering two cases: (a when the shape parameter is known and (b when all parameters are unknown. We analyzed some simulated sets in order to investigate the effect of prior belief, loss functions, and performance of the proposed set of estimators of the mixture model parameters.

The influence of prior knowledge on the retrieval-directed function of note taking in prior knowledge activation

NARCIS (Netherlands)

Wetzels, Sandra; Kester, Liesbeth; Van Merriënboer, Jeroen; Broers, Nick

2010-01-01

Wetzels, S. A. J., Kester, L., Van Merriënboer, J. J. G., & Broers, N. J. (2011). The influence of prior knowledge on the retrieval-directed function of note taking in prior knowledge activation. British Journal of Educational Psychology, 81(2), 274-291. doi: 10.1348/000709910X517425

Assessment of prior image induced nonlocal means regularization for low-dose CT reconstruction: Change in anatomy.

Science.gov (United States)

Zhang, Hao; Ma, Jianhua; Wang, Jing; Moore, William; Liang, Zhengrong

2017-09-01

Repeated computed tomography (CT) scans are prescribed for some clinical applications such as lung nodule surveillance. Several studies have demonstrated that incorporating a high-quality prior image into the reconstruction of subsequent low-dose CT (LDCT) acquisitions can either improve image quality or reduce data fidelity requirements. Our proposed previous normal-dose image induced nonlocal means (ndiNLM) regularization method for LDCT is an example of such a method. However, one major concern with prior image based methods is that they might produce false information when the prior image and the current LDCT image show different structures (for example, if a lung nodule emerges, grows, shrinks, or disappears over time). This study aims to assess the performance of the ndiNLM regularization method in situations with change in anatomy. We incorporated the ndiNLM regularization into the statistical image reconstruction (SIR) framework for reconstruction of subsequent LDCT images. Because of its patch-based search mechanism, a rough registration between the prior image and the current LDCT image is adequate for the SIR-ndiNLM method. We assessed the performance of the SIR-ndiNLM method in lung nodule surveillance for two different scenarios: (a) the nodule was not found in a baseline exam but appears in a follow-up LDCT scan; (b) the nodule was present in a baseline exam but disappears in a follow-up LDCT scan. We further investigated the effect of nodule size on the performance of the SIR-ndiNLM method. We found that a relatively large search-window (e.g., 33 × 33) should be used for the SIR-ndiNLM method to account for misalignment between the prior image and the current LDCT image, and to ensure that enough similar patches can be found in the prior image. With proper selection of other parameters, experimental results with two patient datasets demonstrated that the SIR-ndiNLM method did not miss true nodules nor introduce false nodules in the lung nodule

Students' inductive reasoning skills and the relevance of prior knowledge: an exploratory study with a computer-based training course on the topic of acne vulgaris.

Science.gov (United States)

Horn-Ritzinger, Sabine; Bernhardt, Johannes; Horn, Michael; Smolle, Josef

2011-04-01

The importance of inductive instruction in medical education is increasingly growing. Little is known about the relevance of prior knowledge regarding students' inductive reasoning abilities. The purpose is to evaluate this inductive teaching method as a means of fostering higher levels of learning and to explore how individual differences in prior knowledge (high [HPK] vs. low [LPK]) contribute to students' inductive reasoning skills. Twenty-six LPK and 18 HPK students could train twice with an interactive computer-based training object to discover the underlying concept before doing the final comprehension check. Students had a median of 76.9% of correct answers in the first, 90.9% in the second training, and answered 92% of the final assessment questions correctly. More important, 86% of all students succeeded with inductive learning, among them 83% of the HPK students and 89% of the LPK students. Prior knowledge did not predict performance on overall comprehension. This inductive instructional strategy fostered students' deep approaches to learning in a time-effective way.

E AREA LOW LEVEL WASTE FACILITY DOE 435.1 PERFORMANCE ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Wilhite, E

2008-03-31

This Performance Assessment for the Savannah River Site E-Area Low-Level Waste Facility was prepared to meet requirements of Chapter IV of the Department of Energy Order 435.1-1. The Order specifies that a Performance Assessment should provide reasonable assurance that a low-level waste disposal facility will comply with the performance objectives of the Order. The Order also requires assessments of impacts to water resources and to hypothetical inadvertent intruders for purposes of establishing limits on radionuclides that may be disposed near-surface. According to the Order, calculations of potential doses and releases from the facility should address a 1,000-year period after facility closure. The point of compliance for the performance measures relevant to the all pathways and air pathway performance objective, as well as to the impact on water resources assessment requirement, must correspond to the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste following the assumed end of active institutional controls 100 years after facility closure. During the operational and institutional control periods, the point of compliance for the all pathways and air pathway performance measures is the SRS boundary. However, for the water resources impact assessment, the point of compliance remains the point of highest projected dose or concentration beyond a 100-m buffer zone surrounding the disposed waste during the operational and institutional control periods. For performance measures relevant to radon and inadvertent intruders, the points of compliance are the disposal facility surface for all time periods and the disposal facility after the assumed loss of active institutional controls 100 years after facility closure, respectively. The E-Area Low-Level Waste Facility is located in the central region of the SRS known as the General Separations Area. It is an elbow-shaped, cleared area, which curves to the northwest

Sleep complaints affecting school performance at different educational levels.

Science.gov (United States)

Pagel, James F; Kwiatkowski, Carol F

2010-01-01

The clear association between reports of sleep disturbance and poor school performance has been documented for sleepy adolescents. This study extends that research to students outside the adolescent age grouping in an associated school setting (98 middle school students, 67 high school students, and 64 college students). Reported restless legs and periodic limb movements are significantly associated with lower GPA's in junior high students. Consistent with previous studies, daytime sleepiness was the sleep variable most likely to negatively affects high school students. Sleep onset and maintenance insomnia were the reported sleep variables significantly correlated with poorer school performance in college students. This study indicates that different sleep disorder variables negatively affect performance at different age and educational levels.

Guidance on the Technology Performance Level (TPL) Assessment Methodology

Energy Technology Data Exchange (ETDEWEB)

Weber, Jochem [National Renewable Energy Lab. (NREL), Golden, CO (United States); Roberts, Jesse D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Babarit, Aurelien [Ecole Centrale de Nantes (France). Lab. of Research in Hydrodynamics, Energetics and Atmospheric Environment (LHEEA); Costello, Ronan [Wave Venture, Penstraze (United Kingdom); Bull, Diana L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neilson, Kim [Ramboll, Copenhagen (Denmark); Bittencourt, Claudio [DNV GL, London (United Kingdom); Kennedy, Ben [Wave Venture, Penstraze (United Kingdom); Malins, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dykes, Katherine [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

This document presents the revised Technology Performance Level (TPL) assessment methodology. There are three parts to this revised methodology 1) the Stakeholder Needs and Assessment Guidance (this document), 2) the Technical Submission form, 3) the TPL scoring spreadsheet. The TPL assessment is designed to give a technology neutral or agnostic assessment of any wave energy converter technology. The focus of the TPL is on the performance of the technology in meeting the customer’s needs. The original TPL is described in [1, 2] and those references also detail the critical differences in the nature of the TPL when compared to the more widely used technology readiness level (TRL). (Wave energy TRL is described in [3]). The revised TPL is particularly intended to be useful to investors and also to assist technology developers to conduct comprehensive assessments in a way that is meaningful and attractive to investors. The revised TPL assessment methodology has been derived through a structured Systems Engineering approach. This was a formal process which involved analyzing customer and stakeholder needs through the discipline of Systems Engineering. The results of the process confirmed the high level of completeness of the original methodology presented in [1] (as used in the Wave Energy Prize judging) and now add a significantly increased level of detail in the assessment and an improved more investment focused structure. The revised TPL also incorporates the feedback of the Wave Energy Prize judges.

Dual-Task Performance: Influence of Frailty, Level of Physical Activity, and Cognition.

Science.gov (United States)

Giusti Rossi, Paulo; Pires de Andrade, Larissa; Hotta Ansai, Juliana; Silva Farche, Ana Claudia; Carnaz, Leticia; Dalpubel, Daniela; Ferriolli, Eduardo; Assis Carvalho Vale, Francisco; de Medeiros Takahashi, Anielle Cristhine

2018-03-08

Cognition and level of physical activity have been associated with frailty syndrome. The development of tools that assess deficits related to physical and cognitive frailties simultaneously are of common interest. However, little is known about how much these aspects influence the performance of dual-task tests. Our aims were (a) to verify the influence of frailty syndrome and objectively measured physical activity and cognition on the Timed Up and Go (TUG) test and Timed Up and Go associated with dual-task (TUG-DT) performances; and (b) to compare TUG and TUG-DT performances between older adults who develop frailty syndrome. Sixty-four community-dwelling older adults were divided into frail, prefrail, and nonfrail groups, according to frailty phenotype. Assessments included anamnesis, screening of frailty syndrome, cognitive assessment (Addenbrooke's cognitive examination), placement of a triaxial accelerometer to assess level of physical activity, and TUG and TUG-DT (TUG associated with a motor-cognitive task of calling a phone number) performances. After 7 days, the accelerometer was removed. A multiple linear regression was applied to identify which independent variables could explain performances in the TUG and TUG-DT. Subsequently, the analysis of covariance test, adjusted for age, cognition, and level of physical activity covariates, was used to compare test performances. There were no differences in cognition between groups. Significant differences in the level of physical activity were found in the frail group. Compared with the frail group, the nonfrail group required less time and fewer steps to complete the TUG. Regarding the TUG-DT, cognition and age influenced the time spent and number of steps, respectively; however, no differences were found between groups. Frail older adults presented worse performance in the TUG when compared with nonfrail older adults. The dual-task test does not differentiate older adults with frailty syndrome, regardless of

Health system performance at the district level in Indonesia after decentralization

Directory of Open Access Journals (Sweden)

Choi Yoonjoung

2010-03-01

Full Text Available Abstract Background Assessments over the last two decades have showed an overall low level of performance of the health system in Indonesia with wide variation between districts. The reasons advanced for these low levels of performance include the low level of public funding for health and the lack of discretion for health system managers at the district level. When, in 2001, Indonesia implemented a radical decentralization and significantly increased the central transfer of funds to district governments it was widely expected that the performance of the health system would improve. This paper assesses the extent to which the performance of the health system has improved since decentralization. Methods We measured a set of indicators relevant to assessing changes in performance of the health system between two surveys in three areas: utilization of maternal antenatal and delivery care; immunization coverage; and contraceptive source and use. We also measured respondents' demographic characteristics and their living circumstances. These measurements were made in population-based surveys in 10 districts in 2002-03 and repeated in 2007 in the same 10 districts using the same instruments and sampling methods. Results The dominant providers of maternal and child health in these 10 districts are in the private sector. There was a significant decrease in birth deliveries at home, and a corresponding increase in deliveries in health facilities in 5 of the 10 districts, largely due to increased use of private facilities with little change in the already low use of public facilities. Overall, there was no improvement in vaccination of mothers and their children. Of those using modern contraceptive methods, the majority obtained them from the private sector in all districts. Conclusions There has been little improvement in the performance of the health system since decentralization occurred in 2001 even though there have also been significant increases in

Image segmentation with a novel regularized composite shape prior based on surrogate study

Energy Technology Data Exchange (ETDEWEB)

Zhao, Tingting, E-mail: tingtingzhao@mednet.ucla.edu; Ruan, Dan, E-mail: druan@mednet.ucla.edu [The Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States)

2016-05-15

Purpose: Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum. Methods: In the variational image segmentation framework, a regularization for the composite shape prior is designed to incorporate the geometric relevance of individual training data to the target, which is inferred by an image-based surrogate relevance metric. Specifically, this regularization is imposed on the linear weights of composite shapes and serves as a hyperprior. The overall problem is formulated in a unified optimization setting and a variational block-descent algorithm is derived. Results: The performance of the proposed scheme is assessed in both corpus callosum segmentation from an MR image set and clavicle segmentation based on CT images. The resulted shape composition provides a proper preference for the geometrically relevant training data. A paired Wilcoxon signed rank test demonstrates statistically significant improvement of image segmentation accuracy, when compared to multiatlas label fusion method and three other benchmark active contour schemes. Conclusions: This work has developed a novel composite shape prior regularization, which achieves superior segmentation performance than typical benchmark schemes.

Image segmentation with a novel regularized composite shape prior based on surrogate study

International Nuclear Information System (INIS)

Zhao, Tingting; Ruan, Dan

2016-01-01

Purpose: Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum. Methods: In the variational image segmentation framework, a regularization for the composite shape prior is designed to incorporate the geometric relevance of individual training data to the target, which is inferred by an image-based surrogate relevance metric. Specifically, this regularization is imposed on the linear weights of composite shapes and serves as a hyperprior. The overall problem is formulated in a unified optimization setting and a variational block-descent algorithm is derived. Results: The performance of the proposed scheme is assessed in both corpus callosum segmentation from an MR image set and clavicle segmentation based on CT images. The resulted shape composition provides a proper preference for the geometrically relevant training data. A paired Wilcoxon signed rank test demonstrates statistically significant improvement of image segmentation accuracy, when compared to multiatlas label fusion method and three other benchmark active contour schemes. Conclusions: This work has developed a novel composite shape prior regularization, which achieves superior segmentation performance than typical benchmark schemes.

Outcomes of Gonioscopy-assisted Transluminal Trabeculotomy (GATT) in Eyes With Prior Incisional Glaucoma Surgery.

Science.gov (United States)

Grover, Davinder S; Godfrey, David G; Smith, Oluwatosin; Shi, Wei; Feuer, William J; Fellman, Ronald L

2017-01-01

To report on outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in eyes with prior incisional glaucoma surgery. A retrospective review was performed for all patients who underwent a GATT procedure with a history of prior incisional glaucoma surgery. Thirty-five eyes of 35 patients were treated. The mean age was 67.7 years. Nineteen eyes had a prior trabeculectomy, 13 eyes had a prior glaucoma drainage device, 4 eyes had a prior trabectome, and 5 eyes had prior endocyclophotocoagulation. Mean follow-up time was 22.7 months. For all eyes, the mean preoperative intraocular pressure (IOP) (SD) was 25.7 (6.5) mm Hg on 3.2 (1.0) glaucoma medications and at 24 months, the mean IOP (SD) was 15.4 (4.9) mm Hg on 2.0 (1.4) glaucoma medications (P<0.001). The prior trabeculectomy group had a preoperative IOP (SD) of 24.6 (6.4) mm Hg on 3.2 (1.0) medications and at month 24, the mean IOP (SD) was 16.7 (5.6) mm Hg on 2.1 (1.4) glaucoma medications. In the prior glaucoma drainage device group, the mean preoperative IOP (SD) was 27.0 (7.1) mm Hg on 3.4 (1.1) glaucoma medications and at 24 months, the mean IOP (SD) was 12.9 (2.6) mm Hg on 2.1 (1.2) glaucoma medications. At 24 months, the cumulative proportion of failure was 0.4 and the cumulative proportion of reoperation was 0.29. GATT appears to be safe and successful in treating 60% to 70% of open-angle patients with prior incisional glaucoma surgery. When considering all eyes, there was a significant decrease in IOP and required glaucoma medications at 24 months. This surgery should be considered in certain patients with open angles who have failed a primary traditional glaucoma surgery.

Field-measured drag area is a key correlate of level cycling time trial performance

Directory of Open Access Journals (Sweden)

James E. Peterman

2015-08-01

Full Text Available Drag area (Ad is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP and indirectly (Est AP. Also, a graded exercise test was performed to determine $\\dot {V}{O}_{2}$V̇O2 peak, lactate threshold (LT, and economy. $\\dot {V}{O}_{2}$V̇O2 peak ($\\mathrm{l}~\\min ^{-1}$lmin−1 and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively but were not significantly correlated to performance time (r = − 0.42 and −0.45. The correlation with performance time improved significantly (p < 0.05 when these variables were normalized to Ad. Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001 than any combination of non-normalized physiological measure. The best correlate with performance time was field-measured power output during the time trial normalized to Ad (r = − 0.92. AP only accounted for 54% of the variability in Ad. Accordingly, the correlation to performance time was significantly lower using power normalized to AP (r = − 0.75 or Est AP (r = − 0.71. In conclusion, unless normalized to Ad, level time trial performance in the field was not highly correlated to common laboratory measures. Furthermore, our field-measured Ad is easy to determine and was the single best predictor of level time trial performance.

Improved compressed sensing-based cone-beam CT reconstruction using adaptive prior image constraints

Science.gov (United States)

Lee, Ho; Xing, Lei; Davidi, Ran; Li, Ruijiang; Qian, Jianguo; Lee, Rena

2012-04-01

effective way for us to enhance the image quality at the matched regions between the prior and current images compared to the existing PICCS algorithm. Compared to the current CBCT imaging protocols, the APICCS algorithm allows an imaging dose reduction of 10-40 times due to the greatly reduced number of projections and lower x-ray tube current level coming from the low-dose protocol.

Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball

Science.gov (United States)

Giannopoulos, Nikiforos; Vagenas, George; Noutsos, Konstantinos; Barzouka, Karolina; Bergeles, Nikolaos

2017-01-01

Abstract This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2) and playing position (hitters vs. centers vs. opposites) considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs. PMID:28828084

Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball

Directory of Open Access Journals (Sweden)

Giannopoulos Nikiforos

2017-08-01

Full Text Available This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2 and playing position (hitters vs. centers vs. opposites considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs.

Enhanced fault-tolerant quantum computing in d-level systems.

Science.gov (United States)

Campbell, Earl T

2014-12-05

Error-correcting codes protect quantum information and form the basis of fault-tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transversal non-Clifford gate. Codes with the desired property are presented for d-level qudit systems with prime d. The codes use n=d-1 qudits and can detect up to ∼d/3 errors. We quantify the performance of these codes for one approach to quantum computation known as magic-state distillation. Unlike prior work, we find performance is always enhanced by increasing d.

Own and Others’ Prior Experiences Influence Children’s Imitation of Causal Acts

OpenAIRE

Williamson, Rebecca A.; Meltzoff, Andrew N.

2011-01-01

Young children learn from others’ examples, and they do so selectively. We examine whether the efficacy of prior experiences influences children’s imitation. Thirty-six-month-olds had initial experience on a causal learning task either by performing the task themselves or by watching an adult perform it. The nature of the experience was manipulated such that the actor had either an easy or a difficult experience completing the task. Next, a second adult demonstrated an innovative technique fo...

Can an intervention based on a serious videogame prior to cognitive behavioral therapy be helpful in bulimia nervosa? A clinical case study.

Directory of Open Access Journals (Sweden)

Cristina eGiner-Bartolomé

2015-07-01

Full Text Available Background: Several studies have highlighted the implications of impulsivity and novelty seeking for both the maintenance and the process of recovery from bulimia nervosa. Cognitive behavioral therapy (CBT is the treatment of choice for bulimia nervosa, but for some cases, this treatment alone might not be sufficient for reducing the high levels of impulsivity. The paper presents a case report of a patient with bulimia nervosa, examining the effectiveness of using a videogame (Playmancer as an additional intervention designed to address impulsivity. Design: Psychometric and neuropsychological measures were collected at baseline. After this assessment, Playmancer was applied prior to CBT, following an A-B-A-C-A single case experimental design. Impulsivity levels were assessed with the Conners’ Continuous Performance Test II (CPT-II. After the Playmancer treatment, the patient started CBT, and the levels of impulsivity were recorded again. Finally, psychometric and neuropsychological measures were collected after treatment. Weekly frequency of binges and vomiting were also recorded during the entire procedure. Results: After the videogame intervention, psychometric measures such as anxiety levels, impulsivity and novelty seeking decreased. Regarding the neuropsychological measures, impulsivity levels (measured with the CPT-II progressively decreased throughout the intervention, and an improvement in decision making capacities was observed. Furthermore, the frequency of binges also decreased during and after the videogame intervention. Discussion: This case report suggests that using the Playmancer videogame to reduce impulsivity prior to CBT may enhance the final results of the treatment for bulimia nervosa.

Can an intervention based on a serious videogame prior to cognitive behavioral therapy be helpful in bulimia nervosa? A clinical case study.

Science.gov (United States)

Giner-Bartolomé, Cristina; Fagundo, Ana B; Sánchez, Isabel; Jiménez-Murcia, Susana; Santamaría, Juan J; Ladouceur, Robert; Menchón, José M; Fernández-Aranda, Fernando

2015-01-01

Several studies have highlighted the implications of impulsivity and novelty seeking for both the maintenance and the process of recovery from bulimia nervosa (BN). Cognitive behavioral therapy (CBT) is the treatment of choice for BN, but for some cases, this treatment alone might not be sufficient for reducing the high levels of impulsivity. The paper presents a case report of a patient with BN, examining the effectiveness of using a videogame (VG; Playmancer) as an additional intervention designed to address impulsivity. Psychometric and neuropsychological measures were collected at baseline. After this assessment, Playmancer was applied prior to CBT, following an "A-B-A-C-A" single case experimental design. Impulsivity levels were assessed with the Conner's Continuous Performance Test II (CPT-II). After the Playmancer treatment, the patient started CBT, and the levels of impulsivity were recorded again. Finally, psychometric and neuropsychological measures were collected after treatment. Weekly frequency of binges and vomiting were also recorded during the entire procedure. After the VG intervention, psychometric measures such as anxiety levels, impulsivity and novelty seeking decreased. Regarding the neuropsychological measures, impulsivity levels (measured with the CPT-II) progressively decreased throughout the intervention, and an improvement in decision making capacities was observed. Furthermore, the frequency of binges also decreased during and after the VG intervention. This case report suggests that using the Playmancer VG to reduce impulsivity prior to CBT may enhance the final results of the treatment for BN.

Protective effects of acute exercise prior to doxorubicin on cardiac function of breast cancer patients: A proof-of-concept RCT.

Science.gov (United States)

Kirkham, A A; Shave, R E; Bland, K A; Bovard, J M; Eves, N D; Gelmon, K A; McKenzie, D C; Virani, S A; Stöhr, E J; Warburton, D E R; Campbell, K L

2017-10-15

Preclinical studies have reported that a single treadmill session performed 24h prior to doxorubicin provides cardio-protection. We aimed to characterize the acute change in cardiac function following an initial doxorubicin treatment in humans and determine whether an exercise session performed 24h prior to treatment changes this response. Breast cancer patients were randomized to either 30min of vigorous-intensity exercise 24h prior to the first doxorubicin treatment (n=13), or no vigorous exercise for 72h prior to treatment (control, n=11). Echocardiographically-derived left ventricular volumes, longitudinal strain, twist, E/A ratio, and circulating NT-proBNP, a marker of later cardiotoxicity, were measured before and 24-48h after the treatment. Following treatment in the control group, NT-proBNP, end-diastolic and stroke volumes, cardiac output, E/A ratio, strain, diastolic strain rate, twist, and untwist velocity significantly increased (all p≤0.01). Whereas systemic vascular resistance (pvolume overload, and changes in longitudinal strain and twist opposite in direction to documented longer-term changes. An exercise session performed 24h prior to treatment attenuated NT-proBNP release and increased systolic function. Future investigations should verify these findings in a larger cohort and across multiple courses of doxorubicin. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive and Motivational Challenges in Writing: Studying the Relation with Writing Performance across Students' Gender and Achievement Level

Science.gov (United States)

De Smedt, Fien; Merchie, Emmelien; Barendse, Mariska; Rosseel, Yves; De Naeghel, Jessie; Van Keer, Hilde

2018-01-01

In the past, several assessment reports on writing repeatedly showed that elementary school students do not develop the essential writing skills to be successful in school. In this respect, prior research has pointed to the fact that cognitive and motivational challenges are at the root of the rather basic level of elementary students' writing…

High-Level Performance Modeling of SAR Systems

Science.gov (United States)

Chen, Curtis

2006-01-01

SAUSAGE (Still Another Utility for SAR Analysis that s General and Extensible) is a computer program for modeling (see figure) the performance of synthetic- aperture radar (SAR) or interferometric synthetic-aperture radar (InSAR or IFSAR) systems. The user is assumed to be familiar with the basic principles of SAR imaging and interferometry. Given design parameters (e.g., altitude, power, and bandwidth) that characterize a radar system, the software predicts various performance metrics (e.g., signal-to-noise ratio and resolution). SAUSAGE is intended to be a general software tool for quick, high-level evaluation of radar designs; it is not meant to capture all the subtleties, nuances, and particulars of specific systems. SAUSAGE was written to facilitate the exploration of engineering tradeoffs within the multidimensional space of design parameters. Typically, this space is examined through an iterative process of adjusting the values of the design parameters and examining the effects of the adjustments on the overall performance of the system at each iteration. The software is designed to be modular and extensible to enable consideration of a variety of operating modes and antenna beam patterns, including, for example, strip-map and spotlight SAR acquisitions, polarimetry, burst modes, and squinted geometries.

Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation

DEFF Research Database (Denmark)

Mohr, Magni; Nielsen, Jens Jung; Bangsbo, Jens

2011-01-01

The effect of oral caffeine ingestion on intense intermittent exercise performance and muscle interstitial ion concentrations was examined. The study consists of two studies (S1 and S2). In S1 twelve subjects completed the Yo-Yo intermittent recovery level 2 (Yo-Yo IR2) test with prior caffeine (6...... mg/kg b.w.; CAF) or placebo (PLA) intake. In S2 six subjects performed one low intense (20 W) and three intense (50 W) 3-min (separated by 5 min) one-legged knee-extension exercise bouts with (CAF) and without (CON) prior caffeine supplementation for determination of muscle interstitial K(+) and Na...

Parametric Bayesian priors and better choice of negative examples improve protein function prediction.

Science.gov (United States)

Youngs, Noah; Penfold-Brown, Duncan; Drew, Kevin; Shasha, Dennis; Bonneau, Richard

2013-05-01

Computational biologists have demonstrated the utility of using machine learning methods to predict protein function from an integration of multiple genome-wide data types. Yet, even the best performing function prediction algorithms rely on heuristics for important components of the algorithm, such as choosing negative examples (proteins without a given function) or determining key parameters. The improper choice of negative examples, in particular, can hamper the accuracy of protein function prediction. We present a novel approach for choosing negative examples, using a parameterizable Bayesian prior computed from all observed annotation data, which also generates priors used during function prediction. We incorporate this new method into the GeneMANIA function prediction algorithm and demonstrate improved accuracy of our algorithm over current top-performing function prediction methods on the yeast and mouse proteomes across all metrics tested. Code and Data are available at: http://bonneaulab.bio.nyu.edu/funcprop.html

Effect Of Dietary Protein Levels On The Performance And Carcass ...

African Journals Online (AJOL)

Effect Of Dietary Protein Levels On The Performance And Carcass ... Nigerian Journal of Animal Production ... Response criteria such as weight gain and feed conversion ratio, among others, and carcass characteristics were measured.

Offending prior to first psychiatric contact

DEFF Research Database (Denmark)

Stevens, H; Agerbo, E; Dean, K

2012-01-01

There is a well-established association between psychotic disorders and subsequent offending but the extent to which those who develop psychosis might have a prior history of offending is less clear. Little is known about whether the association between illness and offending exists in non-psychot......-psychotic disorders. The aim of this study was to determine whether the association between mental disorder and offending is present prior to illness onset in psychotic and non-psychotic disorders.......There is a well-established association between psychotic disorders and subsequent offending but the extent to which those who develop psychosis might have a prior history of offending is less clear. Little is known about whether the association between illness and offending exists in non...

SLEEP COMPLAINTS AFFECTING SCHOOL PERFORMANCE AT DIFFERENT EDUCATIONAL LEVELS

Directory of Open Access Journals (Sweden)

James F Pagel

2010-11-01

Full Text Available The clear association between reports of sleep disturbance and poor school performance has been documented for sleepy adolescents. This study extends that research to students outside the adolescent age grouping in an associated school setting (98 middle school students, 67 high school students, and 64 college students. Reported restless legs and periodic limb movements are significantly associated with lower GPA’s in junior high students. Consistent with previous studies, daytime sleepiness was the sleep variable most likely to negatively affects high school students. Sleep onset and maintenance insomnia were the reported sleep variables significantly correlated with poorer school performance in college students. This study indicates that different sleep disorder variables negatively affect performance at different age and educational levels.

Personality Characteristics and Level of Performance of Male County Extension Agents in Wisconsin.

Science.gov (United States)

Pandya, Dasharathrai Navnitrai

The major purpose of this study was to determine the relationship between selected personality characteristics and attitudes of male extension agents in Wisconsin, and their level of job performance. The relationships between selected background factors and the level of agent's job performance were also studied. Subjects were 79 male county agents…

Effects of caffeine and anxiety level on psychomotor performance ...

African Journals Online (AJOL)

The study investigated the effects of caffeine and anxiety level on psychomotor performance. Sixty-eight (68) volunteer male and female students who were randomly selected from different academic faculties at the University of Lagos participated in this study. Their ages ranged from 18 to 32 years, with body weights ...

Terminology for pregnancy loss prior to viability

DEFF Research Database (Denmark)

Kolte, A M; Bernardi, L A; Christiansen, O B

2015-01-01

Pregnancy loss prior to viability is common and research in the field is extensive. Unfortunately, terminology in the literature is inconsistent. The lack of consensus regarding nomenclature and classification of pregnancy loss prior to viability makes it difficult to compare study results from...... different centres. In our opinion, terminology and definitions should be based on clinical findings, and when possible, transvaginal ultrasound. With this Early Pregnancy Consensus Statement, it is our goal to provide clear and consistent terminology for pregnancy loss prior to viability....

Improving Bayesian credibility intervals for classifier error rates using maximum entropy empirical priors.

Science.gov (United States)

Gustafsson, Mats G; Wallman, Mikael; Wickenberg Bolin, Ulrika; Göransson, Hanna; Fryknäs, M; Andersson, Claes R; Isaksson, Anders

2010-06-01

Successful use of classifiers that learn to make decisions from a set of patient examples require robust methods for performance estimation. Recently many promising approaches for determination of an upper bound for the error rate of a single classifier have been reported but the Bayesian credibility interval (CI) obtained from a conventional holdout test still delivers one of the tightest bounds. The conventional Bayesian CI becomes unacceptably large in real world applications where the test set sizes are less than a few hundred. The source of this problem is that fact that the CI is determined exclusively by the result on the test examples. In other words, there is no information at all provided by the uniform prior density distribution employed which reflects complete lack of prior knowledge about the unknown error rate. Therefore, the aim of the study reported here was to study a maximum entropy (ME) based approach to improved prior knowledge and Bayesian CIs, demonstrating its relevance for biomedical research and clinical practice. It is demonstrated how a refined non-uniform prior density distribution can be obtained by means of the ME principle using empirical results from a few designs and tests using non-overlapping sets of examples. Experimental results show that ME based priors improve the CIs when employed to four quite different simulated and two real world data sets. An empirically derived ME prior seems promising for improving the Bayesian CI for the unknown error rate of a designed classifier. Copyright 2010 Elsevier B.V. All rights reserved.

Spatially adapted augmentation of age-specific atlas-based segmentation using patch-based priors

Science.gov (United States)

Liu, Mengyuan; Seshamani, Sharmishtaa; Harrylock, Lisa; Kitsch, Averi; Miller, Steven; Chau, Van; Poskitt, Kenneth; Rousseau, Francois; Studholme, Colin

2014-03-01

One of the most common approaches to MRI brain tissue segmentation is to employ an atlas prior to initialize an Expectation- Maximization (EM) image labeling scheme using a statistical model of MRI intensities. This prior is commonly derived from a set of manually segmented training data from the population of interest. However, in cases where subject anatomy varies significantly from the prior anatomical average model (for example in the case where extreme developmental abnormalities or brain injuries occur), the prior tissue map does not provide adequate information about the observed MRI intensities to ensure the EM algorithm converges to an anatomically accurate labeling of the MRI. In this paper, we present a novel approach for automatic segmentation of such cases. This approach augments the atlas-based EM segmentation by exploring methods to build a hybrid tissue segmentation scheme that seeks to learn where an atlas prior fails (due to inadequate representation of anatomical variation in the statistical atlas) and utilize an alternative prior derived from a patch driven search of the atlas data. We describe a framework for incorporating this patch-based augmentation of EM (PBAEM) into a 4D age-specific atlas-based segmentation of developing brain anatomy. The proposed approach was evaluated on a set of MRI brain scans of premature neonates with ages ranging from 27.29 to 46.43 gestational weeks (GWs). Results indicated superior performance compared to the conventional atlas-based segmentation method, providing improved segmentation accuracy for gray matter, white matter, ventricles and sulcal CSF regions.

Incorporation prior belief in the general path model: A comparison of information sources

International Nuclear Information System (INIS)

Coble, Jamie; Hines, Wesley

2014-01-01

The general path model (GPM) is one approach for performing degradation-based, or Type III, prognostics. The GPM fits a parametric function to the collected observations of a prognostic parameter and extrapolates the fit to a failure threshold. This approach has been successfully applied to a variety of systems when a sufficient number of prognostic parameter observations are available. However, the parametric fit can suffer significantly when few data are available or the data are very noisy. In these instances, it is beneficial to include additional information to influence the fit to conform to a prior belief about the evolution of system degradation. Bayesian statistical approaches have been proposed to include prior information in the form of distributions of expected model parameters. This requires a number of run-to-failure cases with tracked prognostic parameters; these data may not be readily available for many systems. Reliability information and stressor-based (Type I and Type II, respectively) prognostic estimates can provide the necessary prior belief for the GPM. This article presents the Bayesian updating framework to include prior information in the GPM and compares the efficacy of including different information sources on two data sets.

Science Literacy and Prior Knowledge of Astronomy MOOC Students

Science.gov (United States)

Impey, Chris David; Buxner, Sanlyn; Wenger, Matthew; Formanek, Martin

2018-01-01

Many of science classes offered on Coursera fall into fall into the category of general education or general interest classes for lifelong learners, including our own, Astronomy: Exploring Time and Space. Very little is known about the backgrounds and prior knowledge of these students. In this talk we present the results of a survey of our Astronomy MOOC students. We also compare these results to our previous work on undergraduate students in introductory astronomy courses. Survey questions examined student demographics and motivations as well as their science and information literacy (including basic science knowledge, interest, attitudes and beliefs, and where they get their information about science). We found that our MOOC students are different than the undergraduate students in more ways than demographics. Many MOOC students demonstrated high levels of science and information literacy. With a more comprehensive understanding of our students’ motivations and prior knowledge about science and how they get their information about science, we will be able to develop more tailored learning experiences for these lifelong learners.

Predictors of academic performance in the discipline-specific bioscience paper: a retrospective qualitative study.

Science.gov (United States)

Khareedi, R

2018-05-01

The cohort of students enrolled in the discipline-specific bioscience paper reflects a structural diversity in that it includes students of multiple ethnicities, varied age groups, differing scholastic and life experiences. These divergent identities of students are known to influence academic performance. The purpose of this retrospective quantitative study was to determine the ability of a set of variables such as age, gender, ethnicity, level of prior education, the place from which prior education was obtained, work experience and prior academic achievement to predict academic performance in the discipline-specific bioscience paper. The sample for this study was a purposive sample of all oral health students who had enrolled in the paper at the Auckland University of Technology from 2011 to 2014. The desensitised empirical data of 116 students from the University's database were subject to multivariable regression analysis. Pearson's correlation coefficients were calculated. Prior academic achievement was a statistically significant predictor variable (P academic performance in the discipline-specific bioscience paper and was also positively correlated (r = 0.641, P academic achievement was the only variable that was demonstrated to be correlated to and predictive of the academic performance in the discipline-specific bioscience paper. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Multi-energy CT based on a prior rank, intensity and sparsity model (PRISM)

International Nuclear Information System (INIS)

Gao, Hao; Osher, Stanley; Yu, Hengyong; Wang, Ge

2011-01-01

We propose a compressive sensing approach for multi-energy computed tomography (CT), namely the prior rank, intensity and sparsity model (PRISM). To further compress the multi-energy image for allowing the reconstruction with fewer CT data and less radiation dose, the PRISM models a multi-energy image as the superposition of a low-rank matrix and a sparse matrix (with row dimension in space and column dimension in energy), where the low-rank matrix corresponds to the stationary background over energy that has a low matrix rank, and the sparse matrix represents the rest of distinct spectral features that are often sparse. Distinct from previous methods, the PRISM utilizes the generalized rank, e.g., the matrix rank of tight-frame transform of a multi-energy image, which offers a way to characterize the multi-level and multi-filtered image coherence across the energy spectrum. Besides, the energy-dependent intensity information can be incorporated into the PRISM in terms of the spectral curves for base materials, with which the restoration of the multi-energy image becomes the reconstruction of the energy-independent material composition matrix. In other words, the PRISM utilizes prior knowledge on the generalized rank and sparsity of a multi-energy image, and intensity/spectral characteristics of base materials. Furthermore, we develop an accurate and fast split Bregman method for the PRISM and demonstrate the superior performance of the PRISM relative to several competing methods in simulations. (papers)

Performance analysis of three-dimensional-triple-level cell and two-dimensional-multi-level cell NAND flash hybrid solid-state drives

Science.gov (United States)

Sakaki, Yukiya; Yamada, Tomoaki; Matsui, Chihiro; Yamaga, Yusuke; Takeuchi, Ken

2018-04-01

In order to improve performance of solid-state drives (SSDs), hybrid SSDs have been proposed. Hybrid SSDs consist of more than two types of NAND flash memories or NAND flash memories and storage-class memories (SCMs). However, the cost of hybrid SSDs adopting SCMs is more expensive than that of NAND flash only SSDs because of the high bit cost of SCMs. This paper proposes unique hybrid SSDs with two-dimensional (2D) horizontal multi-level cell (MLC)/three-dimensional (3D) vertical triple-level cell (TLC) NAND flash memories to achieve higher cost-performance. The 2D-MLC/3D-TLC hybrid SSD achieves up to 31% higher performance than the conventional 2D-MLC/2D-TLC hybrid SSD. The factors of different performance between the proposed hybrid SSD and the conventional hybrid SSD are analyzed by changing its block size, read/write/erase latencies, and write unit of 3D-TLC NAND flash memory, by means of a transaction-level modeling simulator.

High-Level Synthesis: Productivity, Performance, and Software Constraints

Directory of Open Access Journals (Sweden)

Yun Liang

2012-01-01

Full Text Available FPGAs are an attractive platform for applications with high computation demand and low energy consumption requirements. However, design effort for FPGA implementations remains high—often an order of magnitude larger than design effort using high-level languages. Instead of this time-consuming process, high-level synthesis (HLS tools generate hardware implementations from algorithm descriptions in languages such as C/C++ and SystemC. Such tools reduce design effort: high-level descriptions are more compact and less error prone. HLS tools promise hardware development abstracted from software designer knowledge of the implementation platform. In this paper, we present an unbiased study of the performance, usability and productivity of HLS using AutoPilot (a state-of-the-art HLS tool. In particular, we first evaluate AutoPilot using the popular embedded benchmark kernels. Then, to evaluate the suitability of HLS on real-world applications, we perform a case study of stereo matching, an active area of computer vision research that uses techniques also common for image denoising, image retrieval, feature matching, and face recognition. Based on our study, we provide insights on current limitations of mapping general-purpose software to hardware using HLS and some future directions for HLS tool development. We also offer several guidelines for hardware-friendly software design. For popular embedded benchmark kernels, the designs produced by HLS achieve 4X to 126X speedup over the software version. The stereo matching algorithms achieve between 3.5X and 67.9X speedup over software (but still less than manual RTL design with a fivefold reduction in design effort versus manual RTL design.

It Is Not Only Mentoring: The Combined Influences of Individual-Level and Team-Level Support on Job Performance

Science.gov (United States)

van Emmerik, I. J. Hetty

2008-01-01

Purpose: The paper aims to follow social exchange theory and group social capital theory, to predict positive relationships between (informal) mentoring and various support resources for two types of performance (i.e. perceptions of individual and team performance). Design/methodology/approach: The associations of individual-level mentoring and…

Gene regulatory network inference by point-based Gaussian approximation filters incorporating the prior information.

Science.gov (United States)

Jia, Bin; Wang, Xiaodong

2013-12-17

: The extended Kalman filter (EKF) has been applied to inferring gene regulatory networks. However, it is well known that the EKF becomes less accurate when the system exhibits high nonlinearity. In addition, certain prior information about the gene regulatory network exists in practice, and no systematic approach has been developed to incorporate such prior information into the Kalman-type filter for inferring the structure of the gene regulatory network. In this paper, an inference framework based on point-based Gaussian approximation filters that can exploit the prior information is developed to solve the gene regulatory network inference problem. Different point-based Gaussian approximation filters, including the unscented Kalman filter (UKF), the third-degree cubature Kalman filter (CKF3), and the fifth-degree cubature Kalman filter (CKF5) are employed. Several types of network prior information, including the existing network structure information, sparsity assumption, and the range constraint of parameters, are considered, and the corresponding filters incorporating the prior information are developed. Experiments on a synthetic network of eight genes and the yeast protein synthesis network of five genes are carried out to demonstrate the performance of the proposed framework. The results show that the proposed methods provide more accurate inference results than existing methods, such as the EKF and the traditional UKF.

A fast alignment method for breast MRI follow-up studies using automated breast segmentation and current-prior registration

Science.gov (United States)

Wang, Lei; Strehlow, Jan; Rühaak, Jan; Weiler, Florian; Diez, Yago; Gubern-Merida, Albert; Diekmann, Susanne; Laue, Hendrik; Hahn, Horst K.

2015-03-01

In breast cancer screening for high-risk women, follow-up magnetic resonance images (MRI) are acquired with a time interval ranging from several months up to a few years. Prior MRI studies may provide additional clinical value when examining the current one and thus have the potential to increase sensitivity and specificity of screening. To build a spatial correlation between suspicious findings in both current and prior studies, a reliable alignment method between follow-up studies is desirable. However, long time interval, different scanners and imaging protocols, and varying breast compression can result in a large deformation, which challenges the registration process. In this work, we present a fast and robust spatial alignment framework, which combines automated breast segmentation and current-prior registration techniques in a multi-level fashion. First, fully automatic breast segmentation is applied to extract the breast masks that are used to obtain an initial affine transform. Then, a non-rigid registration algorithm using normalized gradient fields as similarity measure together with curvature regularization is applied. A total of 29 subjects and 58 breast MR images were collected for performance assessment. To evaluate the global registration accuracy, the volume overlap and boundary surface distance metrics are calculated, resulting in an average Dice Similarity Coefficient (DSC) of 0.96 and root mean square distance (RMSD) of 1.64 mm. In addition, to measure local registration accuracy, for each subject a radiologist annotated 10 pairs of markers in the current and prior studies representing corresponding anatomical locations. The average distance error of marker pairs dropped from 67.37 mm to 10.86 mm after applying registration.

Can Production Subsidies Explain China's Export Performance? Evidence from Firm-level Data

DEFF Research Database (Denmark)

Gong, Yundan; Yu, Zhihong; Girma, Sourafel

2009-01-01

This paper analyses the relationship between production subsidies and firms" export performance using a very comprehensive and recent firm-level database and controlling for the endogeneity of subsidies. It documents robust evidence that production subsidies stimulate export activity at the inten......This paper analyses the relationship between production subsidies and firms" export performance using a very comprehensive and recent firm-level database and controlling for the endogeneity of subsidies. It documents robust evidence that production subsidies stimulate export activity...

Does attention speed up processing? Decreases and increases of processing rates in visual prior entry.

Science.gov (United States)

Tünnermann, Jan; Petersen, Anders; Scharlau, Ingrid

2015-03-02

Selective visual attention improves performance in many tasks. Among others, it leads to "prior entry"--earlier perception of an attended compared to an unattended stimulus. Whether this phenomenon is purely based on an increase of the processing rate of the attended stimulus or if a decrease in the processing rate of the unattended stimulus also contributes to the effect is, up to now, unanswered. Here we describe a novel approach to this question based on Bundesen's Theory of Visual Attention, which we use to overcome the limitations of earlier prior-entry assessment with temporal order judgments (TOJs) that only allow relative statements regarding the processing speed of attended and unattended stimuli. Prevalent models of prior entry in TOJs either indirectly predict a pure acceleration or cannot model the difference between acceleration and deceleration. In a paradigm that combines a letter-identification task with TOJs, we show that indeed acceleration of the attended and deceleration of the unattended stimuli conjointly cause prior entry. © 2015 ARVO.

Determination of performance criteria for high-level solidified nuclear waste

Energy Technology Data Exchange (ETDEWEB)

Heckman, R.A.; Holdsworth, T.

1979-05-07

To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste.

Determination of performance criteria for high-level solidified nuclear waste

International Nuclear Information System (INIS)

Heckman, R.A.; Holdsworth, T.

1979-01-01

To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste

The performance of broiler finisher birds fed varying levels of feather ...

African Journals Online (AJOL)

The performance of broiler finisher birds fed varying levels of feather meal as replacement for soya bean meal. ... meal increased, feed cost/ kg weight gain increased and both differed significantly (P<0.05) between treatment means, while the birds tolerated feather meal up to 7.5% inclusion level, 2.5% was the optimal.

Enterprise Performance in Asia: Using firm-level data for Policy ...

International Development Research Centre (IDRC) Digital Library (Canada)

Enterprise Performance in Asia: Using firm-level data for Policy-making. Micro and small enterprises play a critical role in job creation and economic ... prevent gender-based violence, and make digital platforms work for inclusive development.

A scale-free structure prior for graphical models with applications in functional genomics.

Directory of Open Access Journals (Sweden)

Paul Sheridan

Full Text Available The problem of reconstructing large-scale, gene regulatory networks from gene expression data has garnered considerable attention in bioinformatics over the past decade with the graphical modeling paradigm having emerged as a popular framework for inference. Analysis in a full Bayesian setting is contingent upon the assignment of a so-called structure prior-a probability distribution on networks, encoding a priori biological knowledge either in the form of supplemental data or high-level topological features. A key topological consideration is that a wide range of cellular networks are approximately scale-free, meaning that the fraction, , of nodes in a network with degree is roughly described by a power-law with exponent between and . The standard practice, however, is to utilize a random structure prior, which favors networks with binomially distributed degree distributions. In this paper, we introduce a scale-free structure prior for graphical models based on the formula for the probability of a network under a simple scale-free network model. Unlike the random structure prior, its scale-free counterpart requires a node labeling as a parameter. In order to use this prior for large-scale network inference, we design a novel Metropolis-Hastings sampler for graphical models that includes a node labeling as a state space variable. In a simulation study, we demonstrate that the scale-free structure prior outperforms the random structure prior at recovering scale-free networks while at the same time retains the ability to recover random networks. We then estimate a gene association network from gene expression data taken from a breast cancer tumor study, showing that scale-free structure prior recovers hubs, including the previously unknown hub SLC39A6, which is a zinc transporter that has been implicated with the spread of breast cancer to the lymph nodes. Our analysis of the breast cancer expression data underscores the value of the scale

Prognostic impact of physical activity prior to myocardial infarction

DEFF Research Database (Denmark)

Ejlersen, Hanne; Andersen, Zorana Jovanovic; von Euler-Chelpin, My Catarina

2017-01-01

the course of myocardial infarction by reducing case fatality and the subsequent risk of heart failure and mortality. Methods: A total of 14,223 participants in the Copenhagen City Heart Study were assessed at baseline in 1976-1978; 1,664 later developed myocardial infarction (mean age at myocardial...... estimated by logistic and Cox proportional hazards regression models, adjusted for age at myocardial infarction and other potential confounders. Results: A total of 425 (25.5%) myocardial infarctions were fatal. Higher levels of LTPA prior to myocardial infarction were associated with lower case fatality...

Measurement of health system performance at district level: A study protocol

Directory of Open Access Journals (Sweden)

Atul Sharma

2018-01-01

Full Text Available Background: Limited efforts have been observed in low and middle income countries to undertake health system performance assessment at district level. Absence of a comprehensive data collection tool and lack of a standardised single summary measure defining overall performance are some of the main problems. Present study has been undertaken to develop a summary composite health system performance index at district level. Methods: A broad range of indicators covering all six domains as per building block framework were finalized by an expert panel. The domains were classified into twenty sub-domains, with 70 input and process indicators to measure performance. Seven sub-domains for assessing health system outputs and outcomes were identified, with a total of 28 indicators. Districts in Haryana state from north India were selected for the study. Primary and secondary data will be collected from 378 health facilities, district and state health directorate headquarters. Indicators will be normalized, aggregated to generate composite performance index at district level. Domain specific scores will present the quality of individual building block domains in the public health system. Robustness of the results will be checked using sensitivity analysis. Expected impact for public health: The study presents a methodology for comprehensive assessment of all health system domains on basis of input, process, output and outcome indicators which has never been reported from India. Generation of this index will help identify policy and implementation areas of concern and point towards potential solutions. Results may also help understand relationships between individual building blocks and their sub-components.

Time from prior chemotherapy enhances prognostic risk grouping in the second-line setting of advanced urothelial carcinoma: a retrospective analysis of pooled, prospective phase 2 trials.

Science.gov (United States)

Sonpavde, Guru; Pond, Gregory R; Fougeray, Ronan; Choueiri, Toni K; Qu, Angela Q; Vaughn, David J; Niegisch, Guenter; Albers, Peter; James, Nicholas D; Wong, Yu-Ning; Ko, Yoo-Joung; Sridhar, Srikala S; Galsky, Matthew D; Petrylak, Daniel P; Vaishampayan, Ulka N; Khan, Awais; Vogelzang, Nicholas J; Beer, Tomasz M; Stadler, Walter M; O'Donnell, Peter H; Sternberg, Cora N; Rosenberg, Jonathan E; Bellmunt, Joaquim

2013-04-01

Outcomes for patients in the second-line setting of advanced urothelial carcinoma (UC) are dismal. The recognized prognostic factors in this context are Eastern Cooperative Oncology Group (ECOG) performance status (PS) >0, hemoglobin level (Hb) 0, LM, Hb statistic=0.638). Setting of prior chemotherapy (metastatic disease vs perioperative) and prior platinum agent (cisplatin or carboplatin) were not prognostic factors. External validation demonstrated a significant association of TFPC with PFS on univariable and most multivariable analyses, and with OS on univariable analyses. Limitations of retrospective analyses are applicable. Shorter TFPC enhances prognostic classification independent of ECOG-PS >0, Hb advanced UC. These data may facilitate drug development and interpretation of trials. Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

Directory of Open Access Journals (Sweden)

Fapojuwo Abraham O

2007-01-01

Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

Directory of Open Access Journals (Sweden)

Abraham O. Fapojuwo

2007-11-01

Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

Alliance capability as a mediator between experience and alliance performance

DEFF Research Database (Denmark)

Heimeriks, Koen; Duysters, Geert

This study centers around the way in which firms can enhance alliance performance through the development of alliance capabilities. Whereas most research has focused on inter-firm antecedents of alliance performance, research on intra-firm antecedents pointing to prior experience and internal...... alliance managers and Vice-Presidents of 151 firms. The survey covers over 2600 alliances for the period 1997-2001. This study not only finds that alliance capabilities partially mediate between alliance experience and alliance performance, but also yields novel insights into the micro-level building...

Hydrological performance assessment on siting the high level radioactive waste repository

International Nuclear Information System (INIS)

Guo Yonghai; Liu Shufen; Wang Ju; Wang Zhiming; Su Rui; Lv Chuanhe; Zong Zihua

2007-01-01

Based on the research experiences in China and some developed countries in the world, the processes and methods on hydrological performance assessment for the siting of high radioactive repository are discussed in this paper. The methods and contents of hydrological performance assessment are discussed respectively for region, area and site hydrological investigation stages. At the same time, the hydrological performance assessment of the potential site for high level radioactive waste in China is introduced. (authors)

Reproducing kernel Hilbert spaces of Gaussian priors

NARCIS (Netherlands)

Vaart, van der A.W.; Zanten, van J.H.; Clarke, B.; Ghosal, S.

2008-01-01

We review definitions and properties of reproducing kernel Hilbert spaces attached to Gaussian variables and processes, with a view to applications in nonparametric Bayesian statistics using Gaussian priors. The rate of contraction of posterior distributions based on Gaussian priors can be described

Prior Knowledge Assessment Guide

Science.gov (United States)

2014-12-01

assessment in a reasonable amount of time. Hands-on assessments can be extremely diverse in makeup and administration depending on the subject matter...DEVELOPING AND USING PRIOR KNOWLEDGE ASSESSMENTS TO TAILOR TRAINING D-3 ___ Brush and scrub ___ Orchards ___ Rice

Cognitive load predicts point-of-care ultrasound simulator performance.

Science.gov (United States)

Aldekhyl, Sara; Cavalcanti, Rodrigo B; Naismith, Laura M

2018-02-01

The ability to maintain good performance with low cognitive load is an important marker of expertise. Incorporating cognitive load measurements in the context of simulation training may help to inform judgements of competence. This exploratory study investigated relationships between demographic markers of expertise, cognitive load measures, and simulator performance in the context of point-of-care ultrasonography. Twenty-nine medical trainees and clinicians at the University of Toronto with a range of clinical ultrasound experience were recruited. Participants answered a demographic questionnaire then used an ultrasound simulator to perform targeted scanning tasks based on clinical vignettes. Participants were scored on their ability to both acquire and interpret ultrasound images. Cognitive load measures included participant self-report, eye-based physiological indices, and behavioural measures. Data were analyzed using a multilevel linear modelling approach, wherein observations were clustered by participants. Experienced participants outperformed novice participants on ultrasound image acquisition. Ultrasound image interpretation was comparable between the two groups. Ultrasound image acquisition performance was predicted by level of training, prior ultrasound training, and cognitive load. There was significant convergence between cognitive load measurement techniques. A marginal model of ultrasound image acquisition performance including prior ultrasound training and cognitive load as fixed effects provided the best overall fit for the observed data. In this proof-of-principle study, the combination of demographic and cognitive load measures provided more sensitive metrics to predict ultrasound simulator performance. Performance assessments which include cognitive load can help differentiate between levels of expertise in simulation environments, and may serve as better predictors of skill transfer to clinical practice.

Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

DEFF Research Database (Denmark)

Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

2015-01-01

Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test......) prior intake of sodium bicarbonate (0.4 g · kg−1 body weight). Heart rate and rating of perceived exertion (RPE) were measured during the test and venous blood samples were taken frequently. Results Yo-Yo IR2 performance was 14 % higher (P = 0.04) in SBC than in CON (735 ± 61 vs 646 ± 46 m, respectively......-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion....

Fractional Gaussian noise: Prior specification and model comparison

KAUST Repository

Sørbye, Sigrunn Holbek

2017-07-07

Fractional Gaussian noise (fGn) is a stationary stochastic process used to model antipersistent or persistent dependency structures in observed time series. Properties of the autocovariance function of fGn are characterised by the Hurst exponent (H), which, in Bayesian contexts, typically has been assigned a uniform prior on the unit interval. This paper argues why a uniform prior is unreasonable and introduces the use of a penalised complexity (PC) prior for H. The PC prior is computed to penalise divergence from the special case of white noise and is invariant to reparameterisations. An immediate advantage is that the exact same prior can be used for the autocorrelation coefficient ϕ(symbol) of a first-order autoregressive process AR(1), as this model also reflects a flexible version of white noise. Within the general setting of latent Gaussian models, this allows us to compare an fGn model component with AR(1) using Bayes factors, avoiding the confounding effects of prior choices for the two hyperparameters H and ϕ(symbol). Among others, this is useful in climate regression models where inference for underlying linear or smooth trends depends heavily on the assumed noise model.

Fractional Gaussian noise: Prior specification and model comparison

KAUST Repository

Sø rbye, Sigrunn Holbek; Rue, Haavard

2017-01-01

Fractional Gaussian noise (fGn) is a stationary stochastic process used to model antipersistent or persistent dependency structures in observed time series. Properties of the autocovariance function of fGn are characterised by the Hurst exponent (H), which, in Bayesian contexts, typically has been assigned a uniform prior on the unit interval. This paper argues why a uniform prior is unreasonable and introduces the use of a penalised complexity (PC) prior for H. The PC prior is computed to penalise divergence from the special case of white noise and is invariant to reparameterisations. An immediate advantage is that the exact same prior can be used for the autocorrelation coefficient ϕ(symbol) of a first-order autoregressive process AR(1), as this model also reflects a flexible version of white noise. Within the general setting of latent Gaussian models, this allows us to compare an fGn model component with AR(1) using Bayes factors, avoiding the confounding effects of prior choices for the two hyperparameters H and ϕ(symbol). Among others, this is useful in climate regression models where inference for underlying linear or smooth trends depends heavily on the assumed noise model.

What drives slow wave activity during early non-REM sleep: Learning during prior wake or effort?

Directory of Open Access Journals (Sweden)

Ziyang Li

Full Text Available What is the function of sleep in humans? One claim is that sleep consolidates learning. Slow wave activity (SWA, i.e. slow oscillations of frequency < 4 Hz, has been observed in electroencephalograms (EEG during sleep; it increases with prior wakefulness and decreases with sleep. Studies have claimed that increase in SWA in specific regions of the sleeping brain is correlated with overnight improved performance, i.e. overnight consolidation, on a demanding motor learning task. We wondered if SWA change during sleep is attributable to overnight consolidation or to metabolic demand. Participants executed out-and-back movements to a target using a pen-like cursor with their dominant hand while the target and cursor position were displayed on a screen. They trained on three different conditions on separate nights, differing in the amount and degree of rotation between the actual hand movement direction and displayed cursor movement direction. In the no-rotation (NR condition, there was no rotation. In the single rotation (SR condition, the amount of rotation remained the same throughout, and performance improved both across pre-sleep training and after sleep, i.e. overnight consolidation occurred; in the random rotation (RR condition, the amount of rotation varied randomly from trial to trial, and no overnight consolidation occurred; SR and RR were cognitively demanding. The average EEG power density of SWA for the first 30 min. of non-rapid eye movement sleep after training was computed. Both SR and RR elicited increase in SWA in the parietal region; furthermore, the topographic distribution of SWA in each was remarkably similar. No correlation was found between the overnight performance improvement on SR and the SWA change in the parietal region on measures of learning. Our results argue that regulation of SWA in early sleep is associated with high levels of cognitive effort during prior wakefulness, and not just overnight consolidation.

Performance Evaluation of Three-Level Z-Source Inverters Under Semiconductor-Failure Conditions

DEFF Research Database (Denmark)

Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede

2009-01-01

This paper evaluates and proposes various compensation methods for three-level Z-source inverters under semiconductor-failure conditions. Unlike the fault-tolerant techniques used in traditional three-level inverters, where either an extra phase-leg or collective switching states are used......, the proposed methods for three-level Z-source inverters simply reconfigure their relevant gating signals so as to ride-through the failed semiconductor conditions smoothly without any significant decrease in their ac-output quality and amplitude. These features are partly attributed to the inherent boost...... under semiconductor-failure conditions. For verifying these described performance features, PLECS simulation and experimental testing were performed with some results captured and shown in a later section for visual confirmation....

Lung cancer gene expression database analysis incorporating prior knowledge with support vector machine-based classification method

Directory of Open Access Journals (Sweden)

Huang Desheng

2009-07-01

Full Text Available Abstract Background A reliable and precise classification is essential for successful diagnosis and treatment of cancer. Gene expression microarrays have provided the high-throughput platform to discover genomic biomarkers for cancer diagnosis and prognosis. Rational use of the available bioinformation can not only effectively remove or suppress noise in gene chips, but also avoid one-sided results of separate experiment. However, only some studies have been aware of the importance of prior information in cancer classification. Methods Together with the application of support vector machine as the discriminant approach, we proposed one modified method that incorporated prior knowledge into cancer classification based on gene expression data to improve accuracy. A public well-known dataset, Malignant pleural mesothelioma and lung adenocarcinoma gene expression database, was used in this study. Prior knowledge is viewed here as a means of directing the classifier using known lung adenocarcinoma related genes. The procedures were performed by software R 2.80. Results The modified method performed better after incorporating prior knowledge. Accuracy of the modified method improved from 98.86% to 100% in training set and from 98.51% to 99.06% in test set. The standard deviations of the modified method decreased from 0.26% to 0 in training set and from 3.04% to 2.10% in test set. Conclusion The method that incorporates prior knowledge into discriminant analysis could effectively improve the capacity and reduce the impact of noise. This idea may have good future not only in practice but also in methodology.

Advanced ESL Students' Prior EFL Education and Their Perceptions of Oral Corrective Feedback

Science.gov (United States)

Lee, Eun Jeong

2016-01-01

The author in this study examines how advanced-level adult English as a Second Language (ESL) students' previous English as a Foreign Language (EFL) classroom experiences influence their perceptions of their teachers' oral corrective feedback (CF). It uses in-depth qualitative data to characterize the participants' prior English learning, and to…

20 CFR 666.120 - What are the procedures for negotiating annual levels of performance?

Science.gov (United States)

2010-04-01

... performance for each core indicator and the customer satisfaction indicators. In negotiating these levels, the... customer satisfaction; (3) The extent to which the levels of performance promote continuous improvement and... other States, taking into account factors including differences in economic conditions, participant...

Job crafting at the team and individual level: Implications for work engagement and performance

NARCIS (Netherlands)

Tims, M.; Bakker, A.B.; Derks, D.; Rhenen, van W.

2013-01-01

Previous research suggests that employee job crafting is positively related to job performance through employee work engagement. The present study expands this individual-level perspective to the team level by hypothesizing that team job crafting relates positively to team performance through team

Learning priors for Bayesian computations in the nervous system.

Directory of Open Access Journals (Sweden)

Max Berniker

Full Text Available Our nervous system continuously combines new information from our senses with information it has acquired throughout life. Numerous studies have found that human subjects manage this by integrating their observations with their previous experience (priors in a way that is close to the statistical optimum. However, little is known about the way the nervous system acquires or learns priors. Here we present results from experiments where the underlying distribution of target locations in an estimation task was switched, manipulating the prior subjects should use. Our experimental design allowed us to measure a subject's evolving prior while they learned. We confirm that through extensive practice subjects learn the correct prior for the task. We found that subjects can rapidly learn the mean of a new prior while the variance is learned more slowly and with a variable learning rate. In addition, we found that a Bayesian inference model could predict the time course of the observed learning while offering an intuitive explanation for the findings. The evidence suggests the nervous system continuously updates its priors to enable efficient behavior.

Valid MR imaging predictors of prior knee arthroscopy

International Nuclear Information System (INIS)

Discepola, Federico; Le, Huy B.Q.; Park, John S.; Clopton, Paul; Knoll, Andrew N.; Austin, Matthew J.; Resnick, Donald L.

2012-01-01

To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. κ statistics were used to analyze inter-observer agreement. Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p ≥ 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy. (orig.)

Valid MR imaging predictors of prior knee arthroscopy

Energy Technology Data Exchange (ETDEWEB)

Discepola, Federico; Le, Huy B.Q. [McGill University Health Center, Jewsih General Hospital, Division of Musculoskeletal Radiology, Montreal, Quebec (Canada); Park, John S. [Annapolis Radiology Associates, Division of Musculoskeletal Radiology, Annapolis, MD (United States); Clopton, Paul; Knoll, Andrew N.; Austin, Matthew J.; Resnick, Donald L. [University of California San Diego (UCSD), Division of Musculoskeletal Radiology, San Diego, CA (United States)

2012-01-15

To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. {kappa} statistics were used to analyze inter-observer agreement. Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p {>=} 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy. (orig.)

The Effects of Background Noise on the Performance of an Automatic Speech Recogniser

Science.gov (United States)

Littlefield, Jason; HashemiSakhtsari, Ahmad

2002-11-01

Ambient or environmental noise is a major factor that affects the performance of an automatic speech recognizer. Large vocabulary, speaker-dependent, continuous speech recognizers are commercially available. Speech recognizers, perform well in a quiet environment, but poorly in a noisy environment. Speaker-dependent speech recognizers require training prior to them being tested, where the level of background noise in both phases affects the performance of the recognizer. This study aims to determine whether the best performance of a speech recognizer occurs when the levels of background noise during the training and test phases are the same, and how the performance is affected when the levels of background noise during the training and test phases are different. The relationship between the performance of the speech recognizer and upgrading the computer speed and amount of memory as well as software version was also investigated.

Current use of pharmacogenetic testing: a national survey of thiopurine methyltransferase testing prior to azathioprine prescription.

Science.gov (United States)

Fargher, E A; Tricker, K; Newman, W; Elliott, R; Roberts, S A; Shaffer, J L; Bruce, I; Payne, K

2007-04-01

Azathioprine is an immunosuppressant prescribed for the treatment of inflammatory conditions and after organ transplantation. Risk of neutropaenia has limited the effective use of azathioprine (AZA) and driven requirements for careful monitoring and blood tests. Thiopurine methyltransferase (TPMT) is a genetically moderated key enzyme involved in the metabolism of AZA that can be used to stratify individuals into different levels of risk of developing neutropaenia. Two techniques can be used to measure TPMT status: enzyme-level testing (phenotype testing) and DNA based testing (genotype testing). To identify the current uptake of TPMT enzyme-level testing, TPMT genotype testing, and, the role of guidelines; to inform the prescribing and monitoring of AZA. A survey was mailed to a consultant dermatologist, gastroenterologist, and rheumatologist at every NHS Hospital Trust in England. The survey comprised mainly closed questions exploring: use of AZA and monitoring; use of TPMT enzyme-level testing and genotype testing; and, the role of guidelines to guide prescribing practice. A 70% (n=287) response rate was obtained. The majority of respondents reported prescribing AZA (99%, n=283). Prescribing and monitoring patterns differed between individual respondents and between the three disciplines. TPMT enzyme-level testing was reportedly used by 67% (n=189) of respondents, but this differed by discipline (dermatologists 94%, gastroenterologists 60%, rheumatologists 47%). In 91% of cases enzyme-level testing was carried out prior to prescribing AZA. Genotype testing is not typically available to NHS clinicians but 15 clinicians (six dermatologists, six gastroenterologists, three rheumatologists) reported using it. Most consultants (82%) reported using guidelines to inform their AZA prescribing and monitoring (dermatologists 81%, gastroenterologists 75%, rheumatologists 94%). Two-thirds of the consultants surveyed in England are using TPMT enzyme-level testing, prior to

Conscientiousness, openness to experience and extraversion as predictors of nursing work performance: a facet-level analysis.

Science.gov (United States)

Ellershaw, Julia; Fullarton, Christie; Rodwell, John; Mcwilliams, John

2016-03-01

This study examined the relationships between the personality traits of conscientiousness, openness and extraversion at trait and facet-levels and three indicators of work role performance; proficiency, 'adaptivity' and proactivity measured at individual, team and organisational levels. This is one of the first studies to explore the relationship between personality, measured at trait and facet-level and performance using a comprehensive range of performance indicators. An online survey of 393 nurses from health-care organisations across Australia was conducted to test hypothesised relationships. Path analyses revealed numerous relationships between personality, measured at both trait and facet-levels, and work role performance. Conscientiousness was highlighted as the strongest driver of work role performance across all the indicators, with extraversion also strongly associated with work role performance. Openness to experience, previously considered a week predictor of performance, was, when examined at the facet-level, related to all of the work role performance indicators. Results suggests a bandwidth effect, where the personality traits drive global performance while the facets drive specific performance. Better understanding of the relationship between personality and work role performance will help nurse managers to foster the fit between individual and organisation, improving job satisfaction, engagement, retention and performance in role. © 2015 John Wiley & Sons Ltd.

Instruction-level performance modeling and characterization of multimedia applications

Energy Technology Data Exchange (ETDEWEB)

Luo, Y. [Los Alamos National Lab., NM (United States). Scientific Computing Group; Cameron, K.W. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Computer Science

1999-06-01

One of the challenges for characterizing and modeling realistic multimedia applications is the lack of access to source codes. On-chip performance counters effectively resolve this problem by monitoring run-time behaviors at the instruction-level. This paper presents a novel technique of characterizing and modeling workloads at the instruction level for realistic multimedia applications using hardware performance counters. A variety of instruction counts are collected from some multimedia applications, such as RealPlayer, GSM Vocoder, MPEG encoder/decoder, and speech synthesizer. These instruction counts can be used to form a set of abstract characteristic parameters directly related to a processor`s architectural features. Based on microprocessor architectural constraints and these calculated abstract parameters, the architectural performance bottleneck for a specific application can be estimated. Meanwhile, the bottleneck estimation can provide suggestions about viable architectural/functional improvement for certain workloads. The biggest advantage of this new characterization technique is a better understanding of processor utilization efficiency and architectural bottleneck for each application. This technique also provides predictive insight of future architectural enhancements and their affect on current codes. In this paper the authors also attempt to model architectural effect on processor utilization without memory influence. They derive formulas for calculating CPI{sub 0}, CPI without memory effect, and they quantify utilization of architectural parameters. These equations are architecturally diagnostic and predictive in nature. Results provide promise in code characterization, and empirical/analytical modeling.

The effect of pre-course e-learning prior to advanced life support training: a randomised controlled trial.

Science.gov (United States)

Perkins, Gavin D; Fullerton, James N; Davis-Gomez, Nicole; Davies, Robin P; Baldock, Catherine; Stevens, Harry; Bullock, Ian; Lockey, Andrew S

2010-07-01

The role of e-learning in contemporary healthcare education is quickly developing. The aim of this study was to examine the relationship between the use of an e-learning simulation programme (Microsim, Laerdal, UK) prior to attending an Advanced Life Support (ALS) course and the subsequent relationship to candidate performance. An open label, multi-centre randomised controlled study was conducted. The control group received a course manual and pre-course MCQ four weeks prior to the face to face course. The intervention group in addition received the Microsim programme on a CD. The primary outcome was performance during a simulated cardiac arrest at the end of the course. Secondary outcomes were performance during multiple choice exams, resuscitation skills assessments and feedback to Microsim programme. 572 participants were randomised (287 Microsim, 285 control). There were no significant differences in the primary outcome (performance during a standard cardiac arrest simulation) or secondary outcomes. User evaluations were favorable. 79% would recommend it to colleagues. 9% stated Microsim could replace the entire ALS course, 25% parts. Over 70% of participants' perceived that Microsim improved their understanding of the key learning domains of the ALS course. Distributing Microsim to healthcare providers prior to attending an ALS courses did not improve either cognitive or psychomotor skills performance during cardiac arrest simulation testing. The challenge that lies ahead is to identify the optimal way to use e-learning as part of a blended approach to learning for this type of training programme.

Calibrated birth-death phylogenetic time-tree priors for bayesian inference.

Science.gov (United States)

Heled, Joseph; Drummond, Alexei J

2015-05-01

Here we introduce a general class of multiple calibration birth-death tree priors for use in Bayesian phylogenetic inference. All tree priors in this class separate ancestral node heights into a set of "calibrated nodes" and "uncalibrated nodes" such that the marginal distribution of the calibrated nodes is user-specified whereas the density ratio of the birth-death prior is retained for trees with equal values for the calibrated nodes. We describe two formulations, one in which the calibration information informs the prior on ranked tree topologies, through the (conditional) prior, and the other which factorizes the prior on divergence times and ranked topologies, thus allowing uniform, or any arbitrary prior distribution on ranked topologies. Although the first of these formulations has some attractive properties, the algorithm we present for computing its prior density is computationally intensive. However, the second formulation is always faster and computationally efficient for up to six calibrations. We demonstrate the utility of the new class of multiple-calibration tree priors using both small simulations and a real-world analysis and compare the results to existing schemes. The two new calibrated tree priors described in this article offer greater flexibility and control of prior specification in calibrated time-tree inference and divergence time dating, and will remove the need for indirect approaches to the assessment of the combined effect of calibration densities and tree priors in Bayesian phylogenetic inference. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

Indoor Air Quality in 24 California Residences Designed as High-Performance Homes

Energy Technology Data Exchange (ETDEWEB)

Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mullen, Nasim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2015-07-01

Today’s high performance green homes are reaching previously unheard of levels of airtightness and are using new materials, technologies and strategies, whose impacts on Indoor Air Quality (IAQ) cannot be fully anticipated from prior studies. This research study used pollutant measurements, home inspections, diagnostic testing and occupant surveys to assess IAQ in 24 new or deeply retrofitted homes designed to be high performance green buildings in California.

Effects of prior exposure to office noise and music on aspects of working memory.

Science.gov (United States)

Smith, Andrew; Waters, Beth; Jones, Hywel

2010-01-01

Previous research has suggested that prior exposure to noise reduces the effect of subsequent exposure due to habituation. Similarly, a number of studies have shown that exposure to Mozart's music leads to better subsequent spatial reasoning performance. Two studies were conducted to extend these findings. The first one examined whether habituation occurs to office noise (including speech) and, if so, how long it takes to develop. Thirty-six young adults participated in the first study which compared effects of office noise with quiet on the performance of a maths task. The study also examined the effects of prior exposure to the office noise on the subsequent effect of the noise. The results showed that performance was initially impaired by the office noise but that the effects of the noise were removed by 10 minutes of exposure between tasks. The second experiment attempted to replicate the "Mozart effect" which represents an improvement in spatial reasoning following listening to Mozart. The study also examined whether the Mozart effect could be explained by changes in mood. Twenty-four young adults participated in the study. The results replicated the Mozart effect and showed that it was not due to changes in mood. Overall, these results show that prior exposure to noise or music can influence aspects of working memory. Such effects need to be incorporated into models of effects of noise on cognition and attempts have to be made to eliminate alternative explanations rather than just describing changes that occur in specific contexts.

Effects of prior exposure to office noise and music on aspects of working memory

Directory of Open Access Journals (Sweden)

Andrew Smith

2010-01-01

Full Text Available Previous research has suggested that prior exposure to noise reduces the effect of subsequent exposure due to habituation. Similarly, a number of studies have shown that exposure to Mozart′s music leads to better subsequent spatial reasoning performance. Two studies were conducted to extend these findings. The first one examined whether habituation occurs to office noise (including speech and, if so, how long it takes to develop. Thirty-six young adults participated in the first study which compared effects of office noise with quiet on the performance of a maths task. The study also examined the effects of prior exposure to the office noise on the subsequent effect of the noise. The results showed that performance was initially impaired by the office noise but that the effects of the noise were removed by 10 minutes of exposure between tasks. The second experiment attempted to replicate the "Mozart effect" which represents an improvement in spatial reasoning following listening to Mozart. The study also examined whether the Mozart effect could be explained by changes in mood. Twenty-four young adults participated in the study. The results replicated the Mozart effect and showed that it was not due to changes in mood. Overall, these results show that prior exposure to noise or music can influence aspects of working memory. Such effects need to be incorporated into models of effects of noise on cognition and attempts have to be made to eliminate alternative explanations rather than just describing changes that occur in specific contexts.

Performance assessment for future low-level waste disposal facilities at ORNL

International Nuclear Information System (INIS)

Lee, D.W.; Kocher, D.C.

1989-01-01

This paper discusses the strategy for waste management on the Oak Ridge Reservation (ORR) and the approach to preparing future performance assessments that has evolved from previous performance assessment studies of low-level radioactive waste disposal on the ORR. The strategy for waste management is based on the concept that waste classification should be determined by performance assessment other than the sources of waste. This dose-based strategy for waste classification and management places special importance on the preparation and interpretation of waste disposal performance assessments for selecting appropriate disposal technologies and developing waste acceptance criteria. Additionally, the challenges to be overcome in the preparation of performance assessments are discussed. 7 refs

Effects of Repeated-Sprint Training in Hypoxia on Sea-Level Performance: A Meta-Analysis.

Science.gov (United States)

Brocherie, Franck; Girard, Olivier; Faiss, Raphaël; Millet, Grégoire P

2017-08-01

Repeated-sprint training in hypoxia (RSH) is a recent intervention regarding which numerous studies have reported effects on sea-level physical performance outcomes that are debated. No previous study has performed a meta-analysis of the effects of RSH. We systematically reviewed the literature and meta-analyzed the effects of RSH versus repeated-sprint training in normoxia (RSN) on key components of sea-level physical performance, i.e., best and mean (all sprint) performance during repeated-sprint exercise and aerobic capacity (i.e., maximal oxygen uptake [[Formula: see text

Effects of disulfiram on choice behavior in a rodent gambling task: association with catecholamine levels.

Science.gov (United States)

Di Ciano, Patricia; Manvich, Daniel F; Pushparaj, Abhiram; Gappasov, Andrew; Hess, Ellen J; Weinshenker, David; Le Foll, Bernard

2018-01-01

Gambling disorder is a growing societal concern, as recognized by its recent classification as an addictive disorder in the DSM-5. Case reports have shown that disulfiram reduces gambling-related behavior in humans. The purpose of the present study was to determine whether disulfiram affects performance on a rat gambling task, a rodent version of the Iowa gambling task in humans, and whether any changes were associated with alterations in dopamine and/or norepinephrine levels. Rats were administered disulfiram prior to testing on the rat gambling task or prior to analysis of dopamine or norepinephrine levels in brain homogenates. Rats in the behavioral task were divided into two subgroups (optimal vs suboptimal) based on their baseline levels of performance in the rat gambling task. Rats in the optimal group chose the advantageous strategy more, and rats in the suboptimal group (a parallel to problem gambling) chose the disadvantageous strategy more. Rats were not divided into optimal or suboptimal groups prior to neurochemical analysis. Disulfiram administered 2 h, but not 30 min, before the task dose-dependently improved choice behavior in the rats with an initial disadvantageous "gambling-like" strategy, while having no effect on the rats employing an advantageous strategy. The behavioral effects of disulfiram were associated with increased striatal dopamine and decreased striatal norepinephrine. These findings suggest that combined actions on dopamine and norepinephrine may be a useful treatment for gambling disorders.

ASPECT (Automated System-level Performance Evaluation and Characterization Tool), Phase II

Data.gov (United States)

National Aeronautics and Space Administration — SSCI has developed a suite of SAA tools and an analysis capability referred to as ASPECT (Automated System-level Performance Evaluation and Characterization Tool)....

Students' Level of Boredom, Boredom Coping Strategies, Epistemic Curiosity, and Graded Performance

Science.gov (United States)

Eren, Altay; Coskun, Hamit

2016-01-01

The authors examined the relationships among students' levels of boredom, boredom coping strategies, epistemic curiosity, and graded performance regarding mathematics lessons, with the intention to explore the mediating roles of boredom coping strategies and epistemic curiosity in the relationship between the level of boredom and graded…

Improving Open Access through Prior Learning Assessment

Science.gov (United States)

Yin, Shuangxu; Kawachi, Paul

2013-01-01

This paper explores and presents new data on how to improve open access in distance education through using prior learning assessments. Broadly there are three types of prior learning assessment (PLAR): Type-1 for prospective students to be allowed to register for a course; Type-2 for current students to avoid duplicating work-load to gain…

The effect of fasting on surgical performance

DEFF Research Database (Denmark)

Schefte, David Fenger; Rosenstock, Steffen Jais

2016-01-01

BACKGROUND: It is unknown whether fasting has any impact on surgical performance. This simulator-based study investigates whether fasting affects surgical performance. METHODS: Twelve healthy medical students [seven women, mean age 26.5 years (range 23-34)] with no prior experience with surgical...... simulators underwent a short course introduction to the LapSim(®) simulator. After having reached a predefined level, the participants performed five simulated salpingectomies on the LapSim(®) simulator 5-30 days after the initial introduction. The procedures took place at 9 a.m. and 2 p.m. after fasting...... in the longitudinal axis with the left hand. CONCLUSION: The simulator-based study suggests that 17 h of fasting does not deteriorate surgical performance. Further studies on the effect of fasting on surgical performance are needed....

Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks.

Science.gov (United States)

Reay, Jonathon L; Kennedy, David O; Scholey, Andrew B

2006-11-01

Single doses of the traditional herbal treatment Panax ginseng have recently been shown to lower blood glucose levels and elicit cognitive improvements in healthy, overnight-fasted volunteers. The specific mechanisms responsible for these effects are not known. However, cognitive improvements may be related to the glycaemic properties of Panax ginseng. Using a double-blind, placebo-controlled, balanced-crossover design, 27 healthy young adults completed a 10 minute "cognitive demand" test battery at baseline. They then consumed capsules containing either ginseng (extract G115) or a placebo and 30 minutes later a drink containing glucose or placebo. A further 30 minutes later (i.e. 60 minutes post-baseline/capsules) they completed the "cognitive demand" battery six times in immediate succession. Depending on the condition to which the participant was allocated on that particular day, the combination of capsules/drink treatments corresponded to a dose of: 0mg G115/0 mg glucose (placebo); 200mg G115/0 mg glucose (ginseng); 0 mg G115/25 g glucose (glucose) or 200 mg G115/25 g glucose (ginseng/glucose combination). The 10 minute "cognitive demand" battery comprised a Serial Threes subtraction task (2 min); a Serial Sevens subtraction task (2 min); a Rapid Visual Information Processing task (5 min); and a "mental fatigue" visual analogue scale. Blood glucose levels were measured prior to the day's treatment, and before and after the post-dose completions of the battery. The results showed that both Panax ginseng and glucose enhanced performance of a mental arithmetic task and ameliorated the increase in subjective feelings of mental fatigue experienced by participants during the later stages of the sustained, cognitively demanding task performance. Accuracy of performing the Rapid Visual Information Processing task (RVIP) was also improved following the glucose load. There was no evidence of a synergistic relationship between Panax ginseng and exogenous glucose ingestion

SENTINEL-2 LEVEL 1 PRODUCTS AND IMAGE PROCESSING PERFORMANCES

Directory of Open Access Journals (Sweden)

S. J. Baillarin

2012-07-01

. The stringent image quality requirements are also described, in particular the geo-location accuracy for both absolute (better than 12.5 m and multi-temporal (better than 0.3 pixels cases. Then, the prototyped image processing techniques (both radiometric and geometric will be addressed. The radiometric corrections will be first introduced. They consist mainly in dark signal and detector relative sensitivity correction, crosstalk correction and MTF restoration. Then, a special focus will be done on the geometric corrections. In particular the innovative method of automatic enhancement of the geometric physical model will be detailed. This method takes advantage of a Global Reference Image database, perfectly geo-referenced, to correct the physical geometric model of each image taken. The processing is based on an automatic image matching process which provides accurate ground control points between a given band of the image to refine and a reference image, allowing to dynamically calibrate the viewing model. The generation of the Global Reference Image database made of Sentinel-2 pre-calibrated mono-spectral images will be also addressed. In order to perform independent validation of the prototyping activity, an image simulator dedicated to Sentinel-2 has been set up. Thanks to this, a set of images have been simulated from various source images and combining different acquisition conditions and landscapes (mountains, deserts, cities …. Given disturbances have been also simulated so as to estimate the end to end performance of the processing chain. Finally, the radiometric and geometric performances obtained by the prototype will be presented. In particular, the geo-location performance of the level-1C products which widely fulfils the image quality requirements will be provided.

SENTINEL-2 Level 1 Products and Image Processing Performances

Science.gov (United States)

Baillarin, S. J.; Meygret, A.; Dechoz, C.; Petrucci, B.; Lacherade, S.; Tremas, T.; Isola, C.; Martimort, P.; Spoto, F.

2012-07-01

stringent image quality requirements are also described, in particular the geo-location accuracy for both absolute (better than 12.5 m) and multi-temporal (better than 0.3 pixels) cases. Then, the prototyped image processing techniques (both radiometric and geometric) will be addressed. The radiometric corrections will be first introduced. They consist mainly in dark signal and detector relative sensitivity correction, crosstalk correction and MTF restoration. Then, a special focus will be done on the geometric corrections. In particular the innovative method of automatic enhancement of the geometric physical model will be detailed. This method takes advantage of a Global Reference Image database, perfectly geo-referenced, to correct the physical geometric model of each image taken. The processing is based on an automatic image matching process which provides accurate ground control points between a given band of the image to refine and a reference image, allowing to dynamically calibrate the viewing model. The generation of the Global Reference Image database made of Sentinel-2 pre-calibrated mono-spectral images will be also addressed. In order to perform independent validation of the prototyping activity, an image simulator dedicated to Sentinel-2 has been set up. Thanks to this, a set of images have been simulated from various source images and combining different acquisition conditions and landscapes (mountains, deserts, cities …). Given disturbances have been also simulated so as to estimate the end to end performance of the processing chain. Finally, the radiometric and geometric performances obtained by the prototype will be presented. In particular, the geo-location performance of the level-1C products which widely fulfils the image quality requirements will be provided.

Training shortest-path tractography: Automatic learning of spatial priors

DEFF Research Database (Denmark)

Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde

2016-01-01

Tractography is the standard tool for automatic delineation of white matter tracts from diffusion weighted images. However, the output of tractography often requires post-processing to remove false positives and ensure a robust delineation of the studied tract, and this demands expert prior...... knowledge. Here we demonstrate how such prior knowledge, or indeed any prior spatial information, can be automatically incorporated into a shortest-path tractography approach to produce more robust results. We describe how such a prior can be automatically generated (learned) from a population, and we...

Acquisition of multiple prior distributions in tactile temporal order judgment

Directory of Open Access Journals (Sweden)

Yasuhito eNagai

2012-08-01

Full Text Available The Bayesian estimation theory proposes that the brain acquires the prior distribution of a task and integrates it with sensory signals to minimize the effect of sensory noise. Psychophysical studies have demonstrated that our brain actually implements Bayesian estimation in a variety of sensory-motor tasks. However, these studies only imposed one prior distribution on participants within a task period. In this study, we investigated the conditions that enable the acquisition of multiple prior distributions in temporal order judgment (TOJ of two tactile stimuli across the hands. In Experiment 1, stimulation intervals were randomly selected from one of two prior distributions (biased to right hand earlier and biased to left hand earlier in association with color cues (green and red, respectively. Although the acquisition of the two priors was not enabled by the color cues alone, it was significant when participants shifted their gaze (above or below in response to the color cues. However, the acquisition of multiple priors was not significant when participants moved their mouths (opened or closed. In Experiment 2, the spatial cues (above and below were used to identify which eye position or retinal cue position was crucial for the eye-movement-dependent acquisition of multiple priors in Experiment 1. The acquisition of the two priors was significant when participants moved their gaze to the cues (i.e., the cue positions on the retina were constant across the priors, as well as when participants did not shift their gazes (i.e., the cue positions on the retina changed according to the priors. Thus, both eye and retinal cue positions were effective in acquiring multiple priors. Based on previous neurophysiological reports, we discuss possible neural correlates that contribute to the acquisition of multiple priors.

Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity.

Science.gov (United States)

Reay, Jonathon L; Kennedy, David O; Scholey, Andrew B

2005-07-01

Single doses of the traditional herbal treatment Panax ginseng have recently been shown to elicit cognitive improvements in healthy young volunteers. The mechanisms by which ginseng improves cognitive performance are not known. However, they may be related to the glycaemic properties of some Panax species. Using a double-blind, placebo-controlled, balanced crossover design, 30 healthy young adults completed a 10 min test battery at baseline, and then six times in immediate succession commencing 60 min after the day's treatment (placebo, 200mg G115 or 400mg G115). The 10 min battery comprised a Serial Threes subtraction task (2 min); a Serial Sevens task (2 min); a Rapid Visual Information Processing task (5 min); then a 'mental fatigue' visual analogue scale. Blood glucose was measured prior to each day's treatment, and before, during and after the post-dose completions of the battery. Both the 200mg and 400mg treatments led to significant reductions in blood glucose levels at all three post-treatment measurements (p 0.005 in all cases). The most notable behavioural effects were associated with 200mg of ginseng and included significantly improved Serial Sevens subtraction task performance and significantly reduced subjective mental fatigue throughout all (with the exception of one time point in each case) of the post-dose completions of the 10 min battery (p 0.05). Overall these data suggest that Panax ginseng can improve performance and subjective feelings of mental fatigue during sustained mental activity. This effect may be related to the acute gluco-regulatory properties of the extract.

Entropy Econometrics for combining regional economic forecasts: A Data-Weighted Prior Estimator

Science.gov (United States)

Fernández-Vázquez, Esteban; Moreno, Blanca

2017-10-01

Forecast combination has been studied in econometrics for a long time, and the literature has shown the superior performance of forecast combination over individual predictions. However, there is still controversy on which is the best procedure to specify the forecast weights. This paper explores the possibility of using a procedure based on Entropy Econometrics, which allows setting the weights for the individual forecasts as a mixture of different alternatives. In particular, we examine the ability of the Data-Weighted Prior Estimator proposed by Golan (J Econom 101(1):165-193, 2001) to combine forecasting models in a context of small sample sizes, a relative common scenario when dealing with time series for regional economies. We test the validity of the proposed approach using a simulation exercise and a real-world example that aims at predicting gross regional product growth rates for a regional economy. The forecasting performance of the Data-Weighted Prior Estimator proposed is compared with other combining methods. The simulation results indicate that in scenarios of heavily ill-conditioned datasets the approach suggested dominates other forecast combination strategies. The empirical results are consistent with the conclusions found in the numerical experiment.

The effect of prior healthcare employment on the wages of registered nurses.

Science.gov (United States)

Yoo, Byung-Kwang; Kim, Minchul; Lin, Tzu-Chun; Sasaki, Tomoko; Ward, Debbie; Spetz, Joanne

2016-08-19

The proportion of registered nurses (RNs) with employment in health-related positions before their initial RN education has increased in the past two decades. Previous research found that prior health-related employment is positively associated with RN workforce supply, potentially due to the wage differences based on different career paths. This study's objective is to test the hypotheses that prior health-related employment is associated with differences in starting wages and with different rates of wage growth for experience as an RN. We conducted a cross-sectional analysis using the 2008 National Sample Survey of Registered Nurses (NSSRN) linked with county-level variables from the Area Health Resource File. We estimated a Heckman model where the second-stage equation's outcome variable was the logarithm of the RN hourly wage, accounting for the self-selection of working or not working as an RN (i.e., the first-stage equation's outcome variable). Key covariates included interaction terms between years of experience, experience squared, and six categories of prior health-related employment (manager, LPN/LVN, allied health, nursing aide, clerk, and all other healthcare positions). Additional covariates included demographics, weekly working hours, marital status, highest nursing degree, and county-level variables (e.g., unemployment rate). We estimated the marginal effect of experience on wage for each type of prior health-related employment, conducting separate analyses for RNs whose initial education was a Bachelor of Science in Nursing (BSN) (unweighted N = 10,345/weighted N = 945,429), RNs whose initial education was an Associate degree (unweighted N = 13,791/weighted N = 1,296,809), and total population combining the former groups (unweighted N = 24,136/weighted N = 2,242,238). Prior health-related employment was associated with higher wages, with the strongest wage differences among BSN-educated RNs. Among BSN-educated RNs, previous

Level-1 muon trigger performance with the full 2017 dataset

CERN Document Server

CMS Collaboration

2018-01-01

This document describes the performance of the CMS Level-1 Muon Trigger with the full dataset of 2017. Efficiency plots are included for each track finder (TF) individually and for the system as a whole. The efficiency is measured to be greater than 90% for all track finders.

Crystalline Silicon Solar Cells with Thin Silicon Passivation Film Deposited prior to Phosphorous Diffusion

Directory of Open Access Journals (Sweden)

Ching-Tao Li

2014-01-01

Full Text Available We demonstrate the performance improvement of p-type single-crystalline silicon (sc-Si solar cells resulting from front surface passivation by a thin amorphous silicon (a-Si film deposited prior to phosphorus diffusion. The conversion efficiency was improved for the sample with an a-Si film of ~5 nm thickness deposited on the front surface prior to high-temperature phosphorus diffusion, with respect to the samples with an a-Si film deposited on the front surface after phosphorus diffusion. The improvement in conversion efficiency is 0.4% absolute with respect to a-Si film passivated cells, that is, the cells with an a-Si film deposited on the front surface after phosphorus diffusion. The new technique provided a 0.5% improvement in conversion efficiency compared to the cells without a-Si passivation. Such performance improvements result from reduced surface recombination as well as lowered contact resistance, the latter of which induces a high fill factor of the solar cell.

Experimental Verification Of Hyper-V Performance Isolation Level

Directory of Open Access Journals (Sweden)

Krzysztof Rzecki

2014-01-01

Full Text Available The need for cost optimization in a broad sense constitutes the basis of operation of every enterprise. In the case of IT structure, which is present in almost every field of activity these days, one of the most commonly applied technologies leading to good cost-to-profit adjustment is virtualization. It consists in locating several operational systems with IT systems on a single server. In order for such optimization to be carried out correctly it has to be strictly controlled by means of allocating access to resources, which is known as performance isolation. Modern virtualizers allow to set up this allocation in quantitative terms (the number of processors, size of RAM, or disc space. It appears, however, that in qualitative terms (processor's time, RAM or hard disc bandwidth the actual allocation of resources does not always correspond with this configuration. This paper provides an experimental presentation of the achievable level of performance isolation of the Hyper-V virtualizer.

Is pre-operative imaging essential prior to ureteric stone surgery?

Science.gov (United States)

Youssef, F R; Wilkinson, B A; Hastie, K J; Hall, J

2012-09-01

The aim of this study was to identify patients not requiring ureteric stone surgery based on pre-operative imaging (within 24 hours) prior to embarking on semirigid ureteroscopy (R-URS) for urolithiasis. The imaging of all consecutive patients on whom R-URS for urolithiasis was performed over a 12-month period was reviewed. All patients had undergone a plain x-ray of the kidney, ureters and bladder (KUB), abdominal non-contrast computed tomography (NCCT-KUB) or both on the day of surgery. A total of 96 patients were identified for the study. Stone sizes ranged from 3 mm to 20 mm. Thirteen patients (14%) were cancelled as no stone(s) were identified on pre-operative imaging. Of the patients cancelled, 8 (62%) required NCCT-KUB to confirm spontaneous stone passage. One in seven patients were stone free on the day of surgery. This negates the need for unnecessary anaesthetic and instrumentation of the urinary tract, with the associated morbidity. Up-to-date imaging prior to embarking on elective ureteric stone surgery is highly recommended.

Adaptive local thresholding for robust nucleus segmentation utilizing shape priors

Science.gov (United States)

Wang, Xiuzhong; Srinivas, Chukka

2016-03-01

This paper describes a novel local thresholding method for foreground detection. First, a Canny edge detection method is used for initial edge detection. Then, tensor voting is applied on the initial edge pixels, using a nonsymmetric tensor field tailored to encode prior information about nucleus size, shape, and intensity spatial distribution. Tensor analysis is then performed to generate the saliency image and, based on that, the refined edge. Next, the image domain is divided into blocks. In each block, at least one foreground and one background pixel are sampled for each refined edge pixel. The saliency weighted foreground histogram and background histogram are then created. These two histograms are used to calculate a threshold by minimizing the background and foreground pixel classification error. The block-wise thresholds are then used to generate the threshold for each pixel via interpolation. Finally, the foreground is obtained by comparing the original image with the threshold image. The effective use of prior information, combined with robust techniques, results in far more reliable foreground detection, which leads to robust nucleus segmentation.

Effect of photoperiod prior to cold acclimation on freezing tolerance and carbohydrate metabolism in alfalfa (Medicago sativa L.).

Science.gov (United States)

Bertrand, Annick; Bipfubusa, Marie; Claessens, Annie; Rocher, Solen; Castonguay, Yves

2017-11-01

Cold acclimation proceeds sequentially in response to decreases in photoperiod and temperature. This study aimed at assessing the impact of photoperiod prior to cold acclimation on freezing tolerance and related biochemical and molecular responses in two alfalfa cultivars. The fall dormant cultivar Evolution and semi-dormant cultivar 6010 were grown in growth chambers under different photoperiods (8, 10, 12, 14 or 16h) prior to cold acclimation. Freezing tolerance was evaluated as well as carbohydrate concentrations, levels of transcripts encoding enzymes of carbohydrate metabolism as well as a K-3dehydrin, before and after cold acclimation. The fall dormant cultivar Evolution had a better freezing tolerance than the semi-dormant cultivar 6010. The effect of photoperiod prior to cold acclimation on the level of freezing tolerance differed between the two cultivars: an 8h-photoperiod induced the highest level of freezing tolerance in Evolution and the lowest in 6010. In Evolution, the 8h-induced superior freezing tolerance was associated with higher concentration of raffinose-family oligosaccharides (RFO). The transcript levels of sucrose synthase (SuSy) decreased whereas those of sucrose phosphatase synthase (SPS) and galactinol synthase (GaS) increased in response to cold acclimation in both cultivars. Our results indicate that RFO metabolism could be involved in short photoperiod-induced freezing tolerance in dormant alfalfa cultivars. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

40 CFR 57.302 - Performance level of interim constant controls.

Science.gov (United States)

2010-07-01

... correction of the effects of any serious deficiencies in the system. For the purpose of this paragraph, at... system if the smelter owner has not upgraded serious deficiencies in the constant control system in... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Performance level of interim constant...

A Clinician Guide to Altitude Training for Optimal Endurance Exercise Performance at Sea Level.

Science.gov (United States)

Constantini, Keren; Wilhite, Daniel P; Chapman, Robert F

2017-06-01

Constantini, Keren, Daniel P. Wilhite, and Robert F. Chapman. A clinician guide to altitude training for optimal endurance exercise performance at sea level. High Alt Med Biol. 18:93-101, 2017.-For well over 50 years, endurance athletes have been utilizing altitude training in an effort to enhance performance in sea level competition. This brief review will offer the clinician a series of evidence-based best-practice guidelines on prealtitude and altitude training considerations, which can ultimately maximize performance improvement outcomes.

Recognition of prior learning candidates’ experiences in a nurse training programme

Directory of Open Access Journals (Sweden)

Nomathemba B. Mothokoa

2018-06-01

Full Text Available Recognition of prior learning (RPL in South Africa is critical to the development of an equitable education and training system. Historically, nursing has been known as one of the professions that provides access to the training and education of marginalised groups who have minimal access to formal education. The advent of implementing RPL in nursing has, however, not been without challenges. The purpose of this study was to explore and describe the experiences of RPL nursing candidates related to a 4-year comprehensive nursing training programme at a nursing education institution in Gauteng. An exploratory, descriptive and contextual qualitative research design was undertaken. The research sample comprised 13 purposefully selected participants. Face-to-face individual interviews, using open-ended questions, were used to collect data, which were analysed using Tesch’s approach. Recognition of prior learning candidates experienced a number of realities as adult learners. On a positive note, their prior knowledge and experience supported them in their learning endeavours. Participants, however, experienced a number of challenges on personal, interpersonal and socialisation, and educational levels. It is important that opportunities are created to support and assist RPL candidates to complete their nursing training. This support structure, among others, should include the provision of RPL-related information, giving appropriate advice, coaching and mentoring, effective administration services, integrated curriculum design, and a variety of formative and summative assessment practices.

Estimating Functions with Prior Knowledge, (EFPK) for diffusions

DEFF Research Database (Denmark)

Nolsøe, Kim; Kessler, Mathieu; Madsen, Henrik

2003-01-01

In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction of a...... of an estimating function. It may be useful when the full Bayesian analysis is difficult to carry out for computational reasons. This is almost always the case for diffusions, which is the focus of this paper, though the method applies in other settings.......In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction...

Work-family conflicts and work performance.

Science.gov (United States)

Roth, Lawrence; David, Emily M

2009-08-01

Prior research indicates that work-family conflict interferes with family far more than it interferes with work. Conservation of resources provides a possible explanation: when shifting resources from family is no longer sufficient to maintain satisfactory work performance, then workers must acquire additional resources or reduce investments in work. One source of such additional resources could be high performance peers in the work group. The performance of workers with resource-rich peers may be less adversely affected by work-family conflict. In this study, 136 employees of a wholesale distribution firm (61% women, 62% minority) working in groups of 7 to 11 in manual labor and low-level administrative jobs rated their own work-to-family conflict. Their supervisors rated workers' performance. Hierarchical regression analysis indicated that work-to-family conflict increasingly adversely affected job performance as work group performance decreased. Hence, work group performance may be an important moderator of the effects of work-family conflict.

Variable Selection for Nonparametric Gaussian Process Priors: Models and Computational Strategies.

Science.gov (United States)

Savitsky, Terrance; Vannucci, Marina; Sha, Naijun

2011-02-01

This paper presents a unified treatment of Gaussian process models that extends to data from the exponential dispersion family and to survival data. Our specific interest is in the analysis of data sets with predictors that have an a priori unknown form of possibly nonlinear associations to the response. The modeling approach we describe incorporates Gaussian processes in a generalized linear model framework to obtain a class of nonparametric regression models where the covariance matrix depends on the predictors. We consider, in particular, continuous, categorical and count responses. We also look into models that account for survival outcomes. We explore alternative covariance formulations for the Gaussian process prior and demonstrate the flexibility of the construction. Next, we focus on the important problem of selecting variables from the set of possible predictors and describe a general framework that employs mixture priors. We compare alternative MCMC strategies for posterior inference and achieve a computationally efficient and practical approach. We demonstrate performances on simulated and benchmark data sets.

Taking it to another level: do personality-based human capital resources matter to firm performance?

Science.gov (United States)

Oh, In-Sue; Kim, Seongsu; Van Iddekinge, Chad H

2015-05-01

Drawing on the attraction-selection-attrition perspective, strategic human resource management (SHRM) scholarship, and recent human capital research, this study explores organization-level emergence of personality (i.e., personality-based human capital resources) and its direct, interactive, and (conditional) indirect effects on organization-level outcomes based on data from 6,709 managers across 71 firms. Results indicate that organization-level mean emotional stability, extraversion, and conscientiousness are positively related to organization-level managerial job satisfaction and labor productivity but not to financial performance. Furthermore, organization-level mean and variance in emotional stability interact to predict all three organization-level outcomes, and organization-level mean and variance in extraversion interact to predict firm financial performance. Specifically, the positive effects of organization-level mean emotional stability and extraversion are stronger when organization-level variance in these traits is lower. Finally, organization-level mean emotional stability, extraversion, and conscientiousness are all positively related to firm financial performance indirectly via labor productivity, and the indirect effects are more positive when organization-level variance in those personality traits is lower. Overall, the findings suggest that personality-based human capital resources demonstrate tangible effects on organization-level outcomes. Theoretical and practical implications of these findings are discussed along with study limitations and future research directions. (c) 2015 APA, all rights reserved.

Arthur Prior and 'Now'

DEFF Research Database (Denmark)

Blackburn, Patrick Rowan; Jørgensen, Klaus Frovin

2016-01-01

’s search led him through the work of Castañeda, and back to his own work on hybrid logic: the first made temporal reference philosophically respectable, the second made it technically feasible in a modal framework. With the aid of hybrid logic, Prior built a bridge from a two-dimensional UT calculus...

Selecting team players: Considering the impact of contextual performance and workplace deviance on selection decisions in the National Football League.

Science.gov (United States)

Whiting, Steven W; Maynes, Timothy D

2016-04-01

Contextual performance and workplace deviance likely influence team functioning and effectiveness and should therefore be considered when evaluating job candidates for team-based roles. However, obtaining this information is difficult given a lack of reliable sources and the desire of job applicants to present themselves in a favorable light. Thus, it is unknown whether those selecting employees for teams incorporate prior contextual performance and workplace deviance into their evaluations, or whether doing so improves the quality of selection decisions. To address these issues, we examined the impact of prior task performance, contextual performance, and workplace deviance on National Football League (NFL) decision maker (organizational insider) and external expert (organizational outsider) evaluations of college football players in the NFL draft, using a content analysis methodology to generate measures of contextual performance and workplace deviance. Our findings indicate that insiders value contextual performance more than outsiders, which is likely because of differing interests and goals that lead to different levels of motivation and/or ability to acquire information about prior contextual performance. We also propose that prior task performance, contextual performance, and workplace deviance will predict player performance in the NFL. Our results support this prediction for task and contextual performance. In addition, we investigated the quality of insider and outsider judgments using Brunswik's (1952) lens model. Implications of our findings for the team selection, contextual performance, and workplace deviance literatures are discussed. (c) 2016 APA, all rights reserved).

Impact of a health safety warning and prior authorisation on the use of piroxicam: a time-series study.

Science.gov (United States)

Carracedo-Martínez, Eduardo; Pia-Morandeira, Agustin; Figueiras, Adolfo

2012-03-01

The aim of this study was to assess the quantitative changes in systemic use of piroxicam after the issue of a health safety warning about its risks and the subsequent implementation of prior authorisation. We determined the number of monthly daily defined doses/1000 inhabitants/day (DHDs) of piroxicam in the period 2005-2008 in a health area in Spain. The data were analysed graphically, and the impact of the safety warning and introduction of prior authorisation were estimated by using segmented regression analysis. The graph showed that the number of DHDs of piroxicam was stable both before and after the health safety warning but registered a very marked decrease after implementation of prior authorisation, after which DHDs of piroxicam remained stable at a 98% inferior level compared with previous to prior authorisation. Segmented regression analysis showed no statistically significant immediate jump in piroxicam utilisation after the safety warning nor a change in the slope afterwards, but it did show a significant immediate jump after prior authorisation. Population exposure to systemic piroxicam remained unaffected by a previous health safety warning but declined sharply after the introduction of prior authorisation. Copyright © 2012 John Wiley & Sons, Ltd.

Design, installation and in-situ performance study of ultrasonic continuous level meter

International Nuclear Information System (INIS)

Surya Prakash, G.; Somayaji, K.M.

1995-01-01

The report discusses the design and the development of a continuous liquid level meter based on ultrasonic pulse-echo technique. A review of various methods for level measurement along with the details of pulse-echo technique are presented. Also discussed is the development of discrete level detectors based on ultrasonic techniques. Lastly, the procedures adopted for in-situ installation of these level meters in FBTR and RML are given along with the field performance study. Some of the typical merits and limitations of the method and the surface preparation procedure are also highlighted. (author) (author)

Perfectionism, Performance, and State Positive Affect and Negative Affect after a Classroom Test

Science.gov (United States)

Flett, Gordon L.; Blankstein, Kirk R.; Hewitt, Paul L.

2009-01-01

The current study examined the associations among trait dimensions of perfectionism, test performance, and levels of positive and negative affect after taking a test. A sample of 92 female university students completed the Multidimensional Perfectionism Scale one week prior to an actual class test. Measures of positive affect and negative affect…

The Influence of Cognitive Reasoning Level, Cognitive Restructuring Ability, Disembedding Ability, Working Memory Capacity, and Prior Knowledge On Students' Performance On Balancing Equations by Inspection.

Science.gov (United States)

Staver, John R.; Jacks, Tom

1988-01-01

Investigates the influence of five cognitive variables on high school students' performance on balancing chemical equations by inspection. Reports that reasoning, restructuring, and disembedding variables could be a single variable, and that working memory capacity does not influence overall performance. Results of hierarchical regression analysis…

Bayesian Prior Probability Distributions for Internal Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Miller, G.; Inkret, W.C.; Little, T.T.; Martz, H.F.; Schillaci, M.E

2001-07-01

The problem of choosing a prior distribution for the Bayesian interpretation of measurements (specifically internal dosimetry measurements) is considered using a theoretical analysis and by examining historical tritium and plutonium urine bioassay data from Los Alamos. Two models for the prior probability distribution are proposed: (1) the log-normal distribution, when there is some additional information to determine the scale of the true result, and (2) the 'alpha' distribution (a simplified variant of the gamma distribution) when there is not. These models have been incorporated into version 3 of the Bayesian internal dosimetric code in use at Los Alamos (downloadable from our web site). Plutonium internal dosimetry at Los Alamos is now being done using prior probability distribution parameters determined self-consistently from population averages of Los Alamos data. (author)

Remote ignitability analysis of high-level radioactive waste

International Nuclear Information System (INIS)

Lundholm, C.W.; Morgan, J.M.; Shurtliff, R.M.; Trejo, L.E.

1992-09-01

The Idaho Chemical Processing Plant (ICPP), was used to reprocess nuclear fuel from government owned reactors to recover the unused uranium-235. These processes generated highly radioactive liquid wastes which are stored in large underground tanks prior to being calcined into a granular solid. The Resource Conservation and Recovery Act (RCRA) and state/federal clean air statutes require waste characterization of these high level radioactive wastes for regulatory permitting and waste treatment purposes. The determination of the characteristic of ignitability is part of the required analyses prior to calcination and waste treatment. To perform this analysis in a radiologically safe manner, a remoted instrument was needed. The remote ignitability Method and Instrument will meet the 60 deg. C. requirement as prescribed for the ignitability in method 1020 of SW-846. The method for remote use will be equivalent to method 1020 of SW-846

Bayesian Model Comparison With the g-Prior

DEFF Research Database (Denmark)

Nielsen, Jesper Kjær; Christensen, Mads Græsbøll; Cemgil, Ali Taylan

2014-01-01

’s asymptotic MAP rule was an improvement, and in this paper we extend the work by Djuric in several ways. Specifically, we consider the elicitation of proper prior distributions, treat the case of real- and complex-valued data simultaneously in a Bayesian framework similar to that considered by Djuric......, and develop new model selection rules for a regression model containing both linear and non-linear parameters. Moreover, we use this framework to give a new interpretation of the popular information criteria and relate their performance to the signal-to-noise ratio of the data. By use of simulations, we also...... demonstrate that our proposed model comparison and selection rules outperform the traditional information criteria both in terms of detecting the true model and in terms of predicting unobserved data. The simulation code is available online....

Variations in task constraints shape emergent performance outcomes and complexity levels in balancing.

Science.gov (United States)

Caballero Sánchez, Carla; Barbado Murillo, David; Davids, Keith; Moreno Hernández, Francisco J

2016-06-01

This study investigated the extent to which specific interacting constraints of performance might increase or decrease the emergent complexity in a movement system, and whether this could affect the relationship between observed movement variability and the central nervous system's capacity to adapt to perturbations during balancing. Fifty-two healthy volunteers performed eight trials where different performance constraints were manipulated: task difficulty (three levels) and visual biofeedback conditions (with and without the center of pressure (COP) displacement and a target displayed). Balance performance was assessed using COP-based measures: mean velocity magnitude (MVM) and bivariate variable error (BVE). To assess the complexity of COP, fuzzy entropy (FE) and detrended fluctuation analysis (DFA) were computed. ANOVAs showed that MVM and BVE increased when task difficulty increased. During biofeedback conditions, individuals showed higher MVM but lower BVE at the easiest level of task difficulty. Overall, higher FE and lower DFA values were observed when biofeedback was available. On the other hand, FE reduced and DFA increased as difficulty level increased, in the presence of biofeedback. However, when biofeedback was not available, the opposite trend in FE and DFA values was observed. Regardless of changes to task constraints and the variable investigated, balance performance was positively related to complexity in every condition. Data revealed how specificity of task constraints can result in an increase or decrease in complexity emerging in a neurobiological system during balance performance.

Spectrally Consistent Satellite Image Fusion with Improved Image Priors

DEFF Research Database (Denmark)

Nielsen, Allan Aasbjerg; Aanæs, Henrik; Jensen, Thomas B.S.

2006-01-01

Here an improvement to our previous framework for satellite image fusion is presented. A framework purely based on the sensor physics and on prior assumptions on the fused image. The contributions of this paper are two fold. Firstly, a method for ensuring 100% spectrally consistency is proposed......, even when more sophisticated image priors are applied. Secondly, a better image prior is introduced, via data-dependent image smoothing....

Performance assessment for low-level waste disposal in the UK

Energy Technology Data Exchange (ETDEWEB)

Ashworth, A.B. [UK Dept. of the Environment, London (United Kingdom)

1995-12-31

British Nuclear Fuels plc (BNFL) operate a site for the disposal of Low Level Radioactive Waste at Drigg in West Cumbria, in North-West England. HMIP are responsible for the regulation of the site with regard to environmental discharges of radioactive materials, both operational and post-closure. This paper is concerned with post-closure matters only. Two post-closure performance assessments have been carried out for this site: one by the National Radiological Protection Board (NRPB) in 1987; and a subsequent one carried out on behalf of HMIP, completed in 1991. Currently, BNFL are preparing a Safety Case for continued operation of the Drigg site, and it expected that the core of this Case will comprise BNFL`s own analysis of post-closure performance. HMIP has developed procedures for the assessment of this Case, based upon experience of the previous Drigg assessments, and also upon the experience of similar work carried out in the assessment of Intermediate Level Waste (ILW) disposal at both deep and shallow potential sites. This paper describes the more important features of these procedures.

Personality, depressive symptoms and prior trauma exposure of new recruits at two Metropolitan Police Service academies in South Africa

OpenAIRE

U Subramaney; E Libhaber; N Pitts; M Vorster

2012-01-01

Background. Police officers are predisposed to trauma exposure. The development of depression and post-traumatic stress disorder (PTSD) may be influenced by personality style, prior exposure to traumatic events and prior depression. Objectives. To describe the personality profiles of new Metropolitan Police Service (MPS) officers, and to determine the association between personality profiles, trauma exposure and depressive symptoms. Methods. We performed a cross-sectional analysis o...

Performance assessment for a hypothetical low-level waste disposal facility

International Nuclear Information System (INIS)

Smith, C.S.; Rohe, M.J.; Ritter, P.D.

1997-01-01

Disposing of low-level waste (LLW) is a concern for many states throughout the United States. A common disposal method is below-grade concrete vaults. Performance assessment analyses make predictions of contaminant release, transport, ingestion, inhalation, or other routes of exposure, and the resulting doses for various disposal methods such as the below-grade concrete vaults. Numerous assumptions are required to simplify the processes associated with the disposal facility to make predictions feasible. In general, these assumptions are made conservatively so as to underestimate the performance of the facility. The objective of this report is to describe the methodology used in conducting a performance assessment for a hypothetical waste facility located in the northeastern United States using real data as much as possible. This report consists of the following: (a) a description of the disposal facility and site, (b) methods used to analyze performance of the facility, (c) the results of the analysis, and (d) the conclusions of this study

Performance assessment for a hypothetical low-level waste disposal facility

Energy Technology Data Exchange (ETDEWEB)

Smith, C.S.; Rohe, M.J.; Ritter, P.D. [and others

1997-01-01

Disposing of low-level waste (LLW) is a concern for many states throughout the United States. A common disposal method is below-grade concrete vaults. Performance assessment analyses make predictions of contaminant release, transport, ingestion, inhalation, or other routes of exposure, and the resulting doses for various disposal methods such as the below-grade concrete vaults. Numerous assumptions are required to simplify the processes associated with the disposal facility to make predictions feasible. In general, these assumptions are made conservatively so as to underestimate the performance of the facility. The objective of this report is to describe the methodology used in conducting a performance assessment for a hypothetical waste facility located in the northeastern United States using real data as much as possible. This report consists of the following: (a) a description of the disposal facility and site, (b) methods used to analyze performance of the facility, (c) the results of the analysis, and (d) the conclusions of this study.

Women's experiences of self-reporting health online prior to their first midwifery visit

DEFF Research Database (Denmark)

Johnsen, Helle; Clausen, Jette Aaroe; Hvidtjørn, Dorte

2018-01-01

BACKGROUND: Information and communication technologies are increasingly used in health care to meet demands of efficiency, safety and patient-centered care. At a large Danish regional hospital, women report their physical, mental health and personal needs prior to their first antenatal visit....... Little is known about the process of self-reporting health, and how this information is managed during the client-professional meeting. AIM: To explore women's experiences of self-reporting their health status and personal needs online prior to the first midwifery visit, and how this information may...... personal health', 'Reducing and generating risk', and 'Bridges and gaps'. Compared to reporting physical health information, more advanced levels of health literacy might be needed to self-assess mental health and personal needs. Self-reporting health can induce feelings of being normal but also increase...

Bayesian Inference for Structured Spike and Slab Priors

DEFF Research Database (Denmark)

Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

2014-01-01

Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...

Performance of the New Turbine Mid-Level Critical Care Ventilators.

Science.gov (United States)

Delgado, Carlos; Romero, Jose E; Puig, Jaume; Izquierdo, Ana; Ferrando, Carlos; Belda, F Javier; Soro, Marina

2017-01-01

During recent years, ventilators using turbines as flow-generating systems have become increasingly more relevant. This bench study was designed to compare triggering and pressurization of 7 turbine mid-level ICU ventilators. We used a dual-chamber lung model to test 7 mid-level ICU ventilators in pressure support mode with levels of 10, 15, and 20 cm H 2 O with 2 PEEP levels of 5 cm H 2 O and the minimum level allowed by the ventilator. A ventilator was connected to the master chamber to simulate 2 different effort levels. Pressure drop, trigger delay time, time to minimum pressure, and pressure time products (PTP) during trigger and the first 300 and 500 ms were analyzed. In the trigger evaluation, the Savina had the highest delay time, whereas the C2, the V60, and the Trilogy had the lowest pressure drops and PTP values in both effort levels. In pressurization capacity assessment using ideal PTP300 and PTP500 percentages, the C2 and the V680 had the best results, and the Carina and the Savina had lower values, with no differences between both effort levels. Differences between PEEP levels did not seem to be relevant. Pressure support mode for tested ventilators worked properly, but pressurization capacity and trigger function performance were clearly superior in the newest machines. The use of PEEP did not modify the results. Copyright © 2017 by Daedalus Enterprises.

Surface-Level Diversity and Decision-Making in Groups: When Does Deep-Level Similarity Help?

OpenAIRE

2006-01-01

Abstract We examined how surface-level diversity (based on race) and deep-level similarities influenced three-person decision-making groups on a hidden-profile task. Surface-level homogeneous groups perceived their information to be less unique and spent less time on the task than surface-level diverse groups. When the groups were given the opportunity to learn about their deep-level similarities prior to t...

Direct and indirect effects of ownership on firm-level environmental performance

Czech Academy of Sciences Publication Activity Database

Earnhart, D.; Lízal, Lubomír

2007-01-01

Roč. 45, č. 4 (2007), s. 66-87 ISSN 0012-8775 Institutional research plan: CEZ:AV0Z70850503 Keywords : ownership structure * firm-level environmental performance * transition economy Subject RIV: AH - Economics Impact factor: 0.413, year: 2007

Shape prior modeling using sparse representation and online dictionary learning.

Science.gov (United States)

Zhang, Shaoting; Zhan, Yiqiang; Zhou, Yan; Uzunbas, Mustafa; Metaxas, Dimitris N

2012-01-01

The recently proposed sparse shape composition (SSC) opens a new avenue for shape prior modeling. Instead of assuming any parametric model of shape statistics, SSC incorporates shape priors on-the-fly by approximating a shape instance (usually derived from appearance cues) by a sparse combination of shapes in a training repository. Theoretically, one can increase the modeling capability of SSC by including as many training shapes in the repository. However, this strategy confronts two limitations in practice. First, since SSC involves an iterative sparse optimization at run-time, the more shape instances contained in the repository, the less run-time efficiency SSC has. Therefore, a compact and informative shape dictionary is preferred to a large shape repository. Second, in medical imaging applications, training shapes seldom come in one batch. It is very time consuming and sometimes infeasible to reconstruct the shape dictionary every time new training shapes appear. In this paper, we propose an online learning method to address these two limitations. Our method starts from constructing an initial shape dictionary using the K-SVD algorithm. When new training shapes come, instead of re-constructing the dictionary from the ground up, we update the existing one using a block-coordinates descent approach. Using the dynamically updated dictionary, sparse shape composition can be gracefully scaled up to model shape priors from a large number of training shapes without sacrificing run-time efficiency. Our method is validated on lung localization in X-Ray and cardiac segmentation in MRI time series. Compared to the original SSC, it shows comparable performance while being significantly more efficient.

Levels of Management Commitment: A Moderator the Structural Relationships among Critical Success Factors of TQM, World-Class Performance in Operations, and Company Financial Performance

Directory of Open Access Journals (Sweden)

Wakhid Slamet Ciptono

2012-01-01

Full Text Available This study investigates the moderating impacts of the three levels of management commitment (top, middle, and low levels on the structural relationships among the constructs— six critical success factors of TQM (quality improvement program, supervisory leadership, supplier involvement, management commitment, training to improve products/services, cross-functional relationships; world-class performance in operations (world-class company practices, operational excellence practices, company non-financial performance; and company financial performance. It uses a sample of 1,332 managers in 140 strategic business units (SBUs within 49 oil and gas companies in Indonesia. The empirical results indicate that the goodness-of-fit of the unconstrained model is much better than that of the constrained model, and this is an indicative that the three level of management moderates the structural relationships among the constructs. Those are, three levels of management act as a moderator variable between critical success factors of TQM, world-class company practices, operational excellence practices, company non-financial performance, and company financial performance. Results further reveal that world-class performances in operations (world-class company practices, operational excellence practices, and company non-financial performance were positively mediated the impact of critical success factors of TQM on company financial performance. Results also point out that five of six critical success factors of TQM positively associated with world-class company practices and operational excellence practices under the three levels of management (top, middle, low. World-class company practices and operational excellence practices have direct and significant effects on company non-financial performance (productivity, operational reliability. Furthermore, empirical results suggest that there is a positive and significant relationship between company non

Growth Performance of Red Sokoto Bucks Fed Inclusion levels of ...

African Journals Online (AJOL)

This study was carried out to evaluate the growth performance of red Sokoto bucks fed two (2) inclusion levels of rawwater soaked and lime soaked Hibiscus sabdariffa seeds in rice offal based diets. A total of twenty one (21) red Sokoto bucks were randomly allotted into seven treatments with three (3) bucks per group while ...

Effect Of Different Protein Levels on The Performance Of Growing ...

African Journals Online (AJOL)

T4 was superior to other treatments in terms of feed to gain ratio, efficiency of feed utilization and reproductive performance. Snails in T1 with 10% CP failed to lay eggs and had the least developed reproductive system. A diet of 15-20% C. P is therefore recommended for growing snails. Key words: Protein levels, snails, ...

RELATIONSHIP BETWEEN THE LEVEL OF SELF-EFFICACY, PERFORMANCE INDICATORS, AND PARTICIPATION IN YOUTH BASKETBALL

Directory of Open Access Journals (Sweden)

Enrique Ortega

2009-01-01

Full Text Available The present study analyzed the relationship between the level of self-efficacy of the player with the ball in basketball, various performance indicators, and individual participation of the youth player in competition, with the goal of being able to establish initial values that help to define game styles and systems that are adapted to the characteristics of the youth player. In order to evaluate the levels of self-efficacy, a questionnaire was administered to 187 players from the under-16 age category. From a total of 22 games, the following variables related to the individual performance of the player were analyzed: a points scored; b shot attempts and shots made of 1, 2, and 3 points; c efficacy percentage of 1, 2, and 3-point shots; d rebounds made; and e personal fouls received. With regard to participation, the following variables were analyzed: f minutes played; g total time of ball possession; h number of ball possessions; i number of passes received; and j number of offensive phases in which the player participates. The results indicate that the performance and participation variables correctly classify 74.2% when differentiating between players with high and low levels of selfefficacy. The players with high levels of self-efficacy presented higher values in the different performance and participation variables than the players with low levels of self-efficacy.

Functional Movement Screening and Paddle-Sport Performance

Directory of Open Access Journals (Sweden)

Andrew Hatchett

2017-06-01

Full Text Available The purpose of the study reported here was to determine the relationship between an endurance paddle-sport athlete’s total functional movement screening (FMS score and individual race performance. Fifty elite level endurance canoeists and kayakers completed the seven-stage FMS protocol prior to the 2016 United States Canoe and Kayak Association National Championship race. Time taken to finish the race was then associated to overall FMS score and respective sub-scores. Total FMS score and various sub-scores were significantly related to race performance. Female and male athletes differed in which sub-scores were shown to be significantly correlated to finishing time. Outcomes from this study indicate that limitations in functional movement are related to endurance paddle-sport race performance.

Maximum entropy reconstruction of spin densities involving non uniform prior

International Nuclear Information System (INIS)

Schweizer, J.; Ressouche, E.; Papoular, R.J.; Zheludev, A.I.

1997-01-01

Diffraction experiments give microscopic information on structures in crystals. A method which uses the concept of maximum of entropy (MaxEnt), appears to be a formidable improvement in the treatment of diffraction data. This method is based on a bayesian approach: among all the maps compatible with the experimental data, it selects that one which has the highest prior (intrinsic) probability. Considering that all the points of the map are equally probable, this probability (flat prior) is expressed via the Boltzman entropy of the distribution. This method has been used for the reconstruction of charge densities from X-ray data, for maps of nuclear densities from unpolarized neutron data as well as for distributions of spin density. The density maps obtained by this method, as compared to those resulting from the usual inverse Fourier transformation, are tremendously improved. In particular, any substantial deviation from the background is really contained in the data, as it costs entropy compared to a map that would ignore such features. However, in most of the cases, before the measurements are performed, some knowledge exists about the distribution which is investigated. It can range from the simple information of the type of scattering electrons to an elaborate theoretical model. In these cases, the uniform prior which considers all the different pixels as equally likely, is too weak a requirement and has to be replaced. In a rigorous bayesian analysis, Skilling has shown that prior knowledge can be encoded into the Maximum Entropy formalism through a model m(rvec r), via a new definition for the entropy given in this paper. In the absence of any data, the maximum of the entropy functional is reached for ρ(rvec r) = m(rvec r). Any substantial departure from the model, observed in the final map, is really contained in the data as, with the new definition, it costs entropy. This paper presents illustrations of model testing

Performance Assessment Monitoring Plan for the Hanford Site Low-Level Waste Burial Grounds

International Nuclear Information System (INIS)

SONNICHSEN, J.C.

2000-01-01

As directed by the U.S. Department of Energy (DOE), Richland Operations Office (DOE-RL), Fluor Hanford, Inc. will implement the requirements of DOE Order 435.1, Radioactive Waste Management, as the requirements relate to the continued operation of the low-level waste disposal facilities on the Hanford Site. DOE Order 435.1 requires a disposal authorization statement authorizing operation (or continued operation) of a low-level waste disposal facility. The objective of this Order is to ensure that all DOE radioactive waste is managed in a manner that protects the environment and personnel and public health and safety. The manual (DOE Order 435.1 Manual) implementing the Order states that a disposal authorization statement shall be issued based on a review of the facility's performance assessment and composite analysis or appropriate Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980 documentation. The disposal authorization shall specify the limits and conditions on construction, design, operations, and closure of the low-level waste facility. Failure to obtain a disposal authorization statement shall result in shutdown of an operational disposal facility. In fulfillment of the requirements of DOE Order 435.1, a disposal authorization statement was issued on October 25, 1999, authorizing the Hanford Site to transfer, receive, possess, and dispose of low-level radioactive waste at the 200 East Area and the 200 West Area Low-Level Burial Grounds. The disposal authorization statement constitutes approval of the performance assessment and composite analysis, authorizes operation of the facility, and includes conditions that the disposal facility must meet. One of the conditions is that monitoring plans for the 200 East Area and 200 West Area Low-Level Burial Grounds be written and approved by the DOE-RL. The monitoring plan is to be updated and implemented within 1 year following issuance of the disposal authorization statement to

Levels of serum-circulating angiogenic factors within 1 week prior to delivery are closely related to conditions of pregnant women with pre-eclampsia, gestational hypertension, and/or fetal growth restriction.

Science.gov (United States)

Nanjo, Sakiko; Minami, Sawako; Mizoguchi, Mika; Yamamoto, Madoka; Yahata, Tamaki; Toujima, Saori; Shiro, Michihisa; Kobayashi, Aya; Muragaki, Yasuteru; Ino, Kazuhiko

2017-12-01

We aimed to investigate maternal serum angiogenic marker profiles within 1 week prior to delivery in cases of gestational hypertension (GH), pre-eclampsia (PE), and/or fetal growth restriction (FGR) with different clinical conditions. We enrolled 165 women with singleton pregnancy. The participants were classified based on three characteristics: (i) proteinuria (GH and PE); (ii) FGR (PE with FGR [PE + FGR], PE alone, and FGR alone); and (iii) onset (early onset PE [EO PE] and late-onset PE [LO PE]). All sera were obtained within 1 week prior to delivery, and soluble fms-like tyrosine kinase 1 (sFlt-1), soluble endoglin (sEng), and placental growth factor (PlGF) were measured with enzyme-linked immunosorbent assay. (i) In PE, a significantly increased sFlt-1, sEng, and sFlt-1 to PlGF ratio (sFlt-1/PlGF) and significantly decreased PlGF were observed compared with GH and Term control, whereas in GH, only sFlt-1/PlGF was significantly higher than Term control. (ii) In PE + FGR, similar changes were more markedly shown compared with PE alone. The FGR alone group exhibited similar tendencies as PE, although significant differences were found in PlGF and sEng levels. (iii) In EO PE, significant changes were observed in all factors compared with LO PE or Term control, while no significant change in PlGF levels was observed between LO PE and Term control. We demonstrated that the levels of circulating angiogenic factors just before delivery are correlated with the severity of hypertensive disorders of pregnancy and FGR. Profiling these specific markers may contribute to better understanding of the clinical conditions in individual patients and their pathogenesis. © 2017 Japan Society of Obstetrics and Gynecology.

The Peptide Vaccine Combined with Prior Immunization of a Conventional Diphtheria-Tetanus Toxoid Vaccine Induced Amyloid β Binding Antibodies on Cynomolgus Monkeys and Guinea Pigs

Directory of Open Access Journals (Sweden)

Akira Yano

2015-01-01

Full Text Available The reduction of brain amyloid beta (Aβ peptides by anti-Aβ antibodies is one of the possible therapies for Alzheimer’s disease. We previously reported that the Aβ peptide vaccine including the T-cell epitope of diphtheria-tetanus combined toxoid (DT induced anti-Aβ antibodies, and the prior immunization with conventional DT vaccine enhanced the immunogenicity of the peptide. Cynomolgus monkeys were given the peptide vaccine subcutaneously in combination with the prior DT vaccination. Vaccination with a similar regimen was also performed on guinea pigs. The peptide vaccine induced anti-Aβ antibodies in cynomolgus monkeys and guinea pigs without chemical adjuvants, and excessive immune responses were not observed. Those antibodies could preferentially recognize Aβ40, and Aβ42 compared to Aβ fibrils. The levels of serum anti-Aβ antibodies and plasma Aβ peptides increased in both animals and decreased the brain Aβ40 level of guinea pigs. The peptide vaccine could induce a similar binding profile of anti-Aβ antibodies in cynomolgus monkeys and guinea pigs. The peptide vaccination could be expected to reduce the brain Aβ peptides and their toxic effects via clearance of Aβ peptides by generated antibodies.

The Artemis workbench for system-level performance evaluation of embedded systems

NARCIS (Netherlands)

Pimentel, A.D.

2008-01-01

In this paper, we present an overview of the Artemis workbench, which provides modelling and simulation methods and tools for efficient performance evaluation and exploration of heterogeneous embedded multimedia systems. More specifically, we describe the Artemis system-level modelling methodology,

Hysteroscopic polypectomy prior to infertility treatment: A cost analysis and systematic review.

Science.gov (United States)

Mouhayar, Youssef; Yin, Ophelia; Mumford, Sunni L; Segars, James H

2017-06-01

The cost of fertility treatment is expensive and interventions that reduce cost can lead to greater efficiency and fewer embryos transferred. Endometrial polyps contribute to infertility and are frequently removed prior to infertility treatment. It is unclear whether polypectomy reduces fertility treatment cost and if so, the magnitude of cost reduction afforded by the procedure. The aim of this study was to determine whether performing office or operative hysteroscopic polypectomy prior to infertility treatment would be cost-effective. PubMed, Embase, and Cochrane libraries were used to identify publications reporting pregnancy rates after hysteroscopic polypectomy. Studies were required to have a polypectomy treatment group and control group of patients with polyps that were not resected. The charges of infertility treatments and polypectomy were obtained through infertility organizations and a private healthcare cost reporting website. These charges were applied to a decision tree model over the range of pregnancy rates observed in the representative studies to calculate an average cost per clinical or ongoing pregnancy. A sensitivity analysis was conducted to assess cost savings of polypectomy over a range of pregnancy rates and polypectomy costs. Pre-treatment office or operative hysteroscopic polypectomy ultimately saved €6658 ($7480) and €728 ($818), respectively, of the average cost per clinical pregnancy in women treated with four cycles of intrauterine insemination. Polypectomy prior to intrauterine insemination was cost-effective for clinical pregnancy rates greater than 30.2% for office polypectomy and 52.6% for operative polypectomy and for polypectomy price <€4414 ($4959). Office polypectomy or operative polypectomy saved €15,854 ($17,813) and €6644 ($7465), respectively, from the average cost per ongoing pregnancy for in vitro fertilization/intracytoplasmic sperm injection treated women and was cost-effective for ongoing pregnancy rates

Combining symbolic cues with sensory input and prior experience in an iterative Bayesian framework

Directory of Open Access Journals (Sweden)

Frederike Hermi Petzschner

2012-08-01

Full Text Available Perception and action are the result of an integration of various sources of information, such as current sensory input, prior experience, or the context in which a stimulus occurs. Often, the interpretation is not trivial hence needs to be learned from the co-occurrence of stimuli. Yet, how do we combine such diverse information to guide our action?Here we use a distance production-reproduction task to investigate the influence of auxiliary, symbolic cues, sensory input, and prior experience on human performance under three different conditions that vary in the information provided. Our results indicate that subjects can (1 learn the mapping of a verbal, symbolic cue onto the stimulus dimension and (2 integrate symbolic information and prior experience into their estimate of displacements.The behavioral results are explained by to two distinct generative models that represent different structural approaches of how a Bayesian observer would combine prior experience, sensory input, and symbolic cue information into a single estimate of displacement. The first model interprets the symbolic cue in the context of categorization, assuming that it reflects information about a distinct underlying stimulus range (categorical model. The second model applies a multi-modal integration approach and treats the symbolic cue as additional sensory input to the system, which is combined with the current sensory measurement and the subjects’ prior experience (cue-combination model. Notably, both models account equally well for the observed behavior despite their different structural assumptions. The present work thus provides evidence that humans can interpret abstract symbolic information and combine it with other types of information such as sensory input and prior experience. The similar explanatory power of the two models further suggest that issues such as categorization and cue-combination could be explained by alternative probabilistic approaches.

The Clinical Impact of Cardiology Consultation Prior to Major Vascular Surgery.

Science.gov (United States)

Davis, Frank M; Park, Yeo June; Grey, Scott F; Boniakowski, Anna E; Mansour, M Ashraf; Jain, Krishna M; Nypaver, Timothy; Grossman, Michael; Gurm, Hitinder; Henke, Peter K

2018-01-01

To understand statewide variation in preoperative cardiology consultation prior to major vascular surgery and to determine whether consultation was associated with differences in perioperative myocardial infarction (poMI). Medical consultation prior to major vascular surgery is obtained to reduce perioperative risk. Despite perceived benefit of preoperative consultation, evidence is lacking specifically for major vascular surgery on the effect of preoperative cardiac consultation. Patient and clinical data were obtained from a statewide vascular surgery registry between January 2012 and December 2014. Patients were risk stratified by revised cardiac risk index category and compared poMI between patients who did or did not receive a preoperative cardiology consultation. We then used logistic regression analysis to compare the rate of poMI across hospitals grouped into quartiles by rate of preoperative cardiology consultation. Our study population comprised 5191 patients undergoing open peripheral arterial bypass (n = 3037), open abdominal aortic aneurysm repair (n = 332), or endovascular aneurysm repair (n = 1822) at 29 hospitals. At the patient level, after risk-stratification by revised cardiac risk index category, there was no association between cardiac consultation and poMI. At the hospital level, preoperative cardiac consultation varied substantially between hospitals (6.9%-87.5%, P 66%) had a reduction in poMI (OR, 0.52; confidence interval: 0.28-0.98; P cardiology consultation for vascular surgery varies greatly between institutions, and does not appear to impact poMI at the patient level. However, reduction of poMI was noted at the hospitals with the highest rate of preoperative cardiology consultation as well as a variety of medical services, suggesting that other hospital culture effects play a role.

Intracranial aneurysm segmentation in 3D CT angiography: Method and quantitative validation with and without prior noise filtering

International Nuclear Information System (INIS)

Firouzian, Azadeh; Manniesing, Rashindra; Flach, Zwenneke H.; Risselada, Roelof; Kooten, Fop van; Sturkenboom, Miriam C.J.M.; Lugt, Aad van der; Niessen, Wiro J.

2011-01-01

Intracranial aneurysm volume and shape are important factors for predicting rupture risk, for pre-surgical planning and for follow-up studies. To obtain these parameters, manual segmentation can be employed; however, this is a tedious procedure, which is prone to inter- and intra-observer variability. Therefore there is a need for an automated method, which is accurate, reproducible and reliable. This study aims to develop and validate an automated method for segmenting intracranial aneurysms in Computed Tomography Angiography (CTA) data. Also, it is investigated whether prior smoothing improves segmentation robustness and accuracy. The proposed segmentation method is implemented in the level set framework, more specifically Geodesic Active Surfaces, in which a surface is evolved to capture the aneurysmal wall via an energy minimization approach. The energy term is composed of three different image features, namely; intensity, gradient magnitude and intensity variance. The method requires minimal user interaction, i.e. a single seed point inside the aneurysm needs to be placed, based on which image intensity statistics of the aneurysm are derived and used in defining the energy term. The method has been evaluated on 15 aneurysms in 11 CTA data sets by comparing the results to manual segmentations performed by two expert radiologists. Evaluation measures were Similarity Index, Average Surface Distance and Volume Difference. The results show that the automated aneurysm segmentation method is reproducible, and performs in the range of inter-observer variability in terms of accuracy. Smoothing by nonlinear diffusion with appropriate parameter settings prior to segmentation, slightly improves segmentation accuracy.

Influence of High Level Features of HVS on Performance of FSIM

Directory of Open Access Journals (Sweden)

P. Dostal

2013-12-01

Full Text Available In this paper the influence of information about high level features of Human Visual System (HVS on objective quality assessment is studied. This was done by extending the existing full-reference objective image quality metric – FSIM – where the different importance of certain areas of image is considered using Phase Congruency (PC algorithm. Here, the estimation of Region of Interest (ROI based on this algorithm is complemented by Fixation Density Maps (FDM containing the information about high level features of HVS. Use of another low level features based algorithm (Phase Spectrum of Fourier Transform was also considered and compared to the PC algorithm. The performance was evaluated qualitatively on images reconstructed according to ROI and quantitatively on images from LIVE database. The correlation between subjective and objective tests was calculated using Pearson’s Correlation Coefficient and Spearman’s Rank Order Coefficient. The statistical significance of the difference between correlation coefficients was assessed by Fisher r-to-z transformation. The performance of the metric was also compared to other state-of-the-art image quality metrics (SSIM, MS-SSIM, and FSIM.

Evaluating Levels of Project Planning and their Effects on Performance in the Nigerian Construction Industry

Directory of Open Access Journals (Sweden)

Godwin Idoro

2012-11-01

Full Text Available This study compares the level of project planning on public andprivate sectors projects and its impact on performance. Thepurpose is to create awareness of the level and effectivenessof the planning done by public and private clients in the deliveryof construction projects. A questionnaire survey administeredto a sample of 130 client representatives selected by stratifi edrandom sampling from the population of public and private clientsin the Nigerian construction industry is used and analysed usingdescriptive statistics, the t-test and Spearman correlation test. Theresults show that the level of preconstruction planning on privatesector projects is higher than that of public sector projects whilethe level of contract planning done by the latter is higher thanthat of the former. Furthermore, the performance of private sectorprojects is higher than that of public sector projects in many of theparameters used. However, the level of preparation of life-cyclecharts that concern project delivery time in both public and privatesectors projects is low and the level of project planning in the twocategories of projects has a limited impact on project performance.The understanding of how public and private sectors projectsperform in planning and its impact are expected to assist publicand private clients to know the challenges ahead of them in theireffort to improve the planning and performance of their projects.

Branch technical position for performance assessment of low-level radioactive waste disposal facilities

International Nuclear Information System (INIS)

Campbell, A.C.; Abramson, L.; Byrne, R.M.

1994-01-01

The U.S. Nuclear Regulatory Commission has developed a Draft Branch Technical Position on Performance Assessment of Low-Level Radioactive Waste Disposal Facilities. The draft technical position addresses important issues in performance assessment modeling and provides a framework and technical basis for conducting and evaluating performance assessments in a disposal facility license application. The technical position also addresses specific technical policy issues and augments existing NRC guidance pertaining to LLW performance assessment

Estimating security betas using prior information based on firm fundamentals

NARCIS (Netherlands)

Cosemans, M.; Frehen, R.; Schotman, P.C.; Bauer, R.

2010-01-01

This paper proposes a novel approach for estimating time-varying betas of individual stocks that incorporates prior information based on fundamentals. We shrink the rolling window estimate of beta towards a firm-specific prior that is motivated by asset pricing theory. The prior captures structural

Relationships among gender, cognitive style, academic major, and performance on the Piaget water-level task.

Science.gov (United States)

Hammer, R E; Hoffer, N; King, W L

1995-06-01

Many researchers have found that more college-age adults than would be expected fail Piaget's water-level task, with women failing more frequently than men. It has been hypothesized that differences in cognitive style may account for performance differences on the water-level task. In the present study, 27 male and 27 female architectural students and 27 male and 27 female liberal-arts students were assessed for their performance on both Piaget's Water-level Task and Witkin's Group Embedded Figures Test. No difference was found in performance of male and female architectural students on either task, but male liberal-arts students scored significantly higher than female liberal-arts students on both measures. A disembedding cognitive style predicted success on the water-level task for the architectural students but not for the liberal arts students.

Changes in driving behavior and cognitive performance with different breath alcohol concentration levels.

Science.gov (United States)

Liu, Yung-Ching; Fu, Shing-Mei

2007-06-01

This study examines the changes in driving behavior and cognitive performance of drivers with different breath alcohol concentration (BrAC) levels. Eight licensed drivers, aged between 20 and 30 years, with BrAC levels of 0.00, 0.25, 0.4 and 0.5 mg/l performed simulated driving tests under high- and low-load conditions. Subjects were asked to assess their subjective psychological load at specified intervals and perform various tasks. The outcome was measured in terms of reaction times for task completion, accuracy rates, and driver's driving behavior. The effects of BrAC vary depending on the task. Performance of tasks involving attention shift, information processing, and short-term memory showed significant deterioration with increasing BrAC, while dangerous external vehicle driving behavior occurred only when the BrAC reached 0.4 mg/l and the deterioration was marked. We can conclude that the cognitive faculty is the first to be impaired by drinking resulting in deteriorated performance in tasks related to divided attention, short-term memory, logical reasoning, followed by visual perception. On the other hand, increasing alcohol dose may not pose an immediate impact on the external vehicle driving behavior but may negatively affect the driver's motor behavior even at low BrAC levels. Experience and will power could compensate for the negative influence of alcohol enabling the drivers to remain in full steering control. This lag between alcohol consumption and impaired driving performance may mislead the drivers in thinking that they are still capable of safe steering and cause them to ignore the potential dangers of drunk driving.

34 CFR 303.403 - Prior notice; native language.

Science.gov (United States)

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Prior notice; native language. 303.403 Section 303.403... TODDLERS WITH DISABILITIES Procedural Safeguards General § 303.403 Prior notice; native language. (a... file a complaint and the timelines under those procedures. (c) Native language. (1) The notice must be...

Performance Assessment for the Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility

Energy Technology Data Exchange (ETDEWEB)

Annette L. Schafer; A. Jeffrey Sondrup; Arthur S. Rood

2012-05-01

This performance assessment for the Remote-Handled Low-Level Radioactive Waste Disposal Facility at the Idaho National Laboratory documents the projected radiological dose impacts associated with the disposal of low-level radioactive waste at the facility. This assessment evaluates compliance with the applicable radiological criteria of the U.S. Department of Energy and the U.S. Environmental Protection Agency for protection of the public and the environment. The calculations involve modeling transport of radionuclides from buried waste to surface soil and subsurface media, and eventually to members of the public via air, groundwater, and food chain pathways. Projections of doses are calculated for both offsite receptors and individuals who inadvertently intrude into the waste after site closure. The results of the calculations are used to evaluate the future performance of the low-level radioactive waste disposal facility and to provide input for establishment of waste acceptance criteria. In addition, one-factor-at-a-time, Monte Carlo, and rank correlation analyses are included for sensitivity and uncertainty analysis. The comparison of the performance assessment results to the applicable performance objectives provides reasonable expectation that the performance objectives will be met

Effects of Performance-Based Financial Incentives on Work Performance: A Study of Technical-Level Employees in the Private Sector in Sri Lanka

Science.gov (United States)

Wickramasinghe, Vathsala; Dabere, Sampath

2012-01-01

The objective of the study is to investigate the effect of performance-based financial incentives on work performance. The study hypothesized that the design features of performance-based financial incentive schemes themselves may influence individuals' work performance. For the study, survey methodology was used and 93 technical-level employees…

Resuscitation Prior to Emergency Endotracheal Intubation: Results of a National Survey

Directory of Open Access Journals (Sweden)

Robert S. Green

2016-09-01

Full Text Available Introduction: Respiratory failure is a common problem in emergency medicine (EM and critical care medicine (CCM. However, little is known about the resuscitation of critically ill patients prior to emergency endotracheal intubation (EETI. Our aim was to describe the resuscitation practices of EM and CCM physicians prior to EETI. Methods: A cross-sectional survey was developed and tested for content validity and retest reliability by members of the Canadian Critical Care Trials Group. The questionnaire was distributed to all EM and CCM physician members of three national organizations. Using three clinical scenarios (trauma, pneumonia, congestive heart failure, we assessed physician preferences for use and types of fluid and vasopressor medication in pre-EETI resuscitation of critically ill patients. Results: In total, 1,758 physicians were surveyed (response rate 50.2%, 882/1,758. Overall, physicians would perform pre-EETI resuscitation using either fluids or vasopressors in 54% (1,193/2,203 of cases. Most physicians would “always/often” administer intravenous fluid pre-EETI in the three clinical scenarios (81%, 1,484/1,830. Crystalloids were the most common fluid physicians would “always/often” administer in congestive heart failure (EM 43%; CCM 44%, pneumonia (EM 97%; CCM 95% and trauma (EM 96%; CCM 96%. Pre-EETI resuscitation using vasopressors was uncommon (4.9%. Training in CCM was associated with performing pre-EETI resuscitation (odds ratio, 2.20; 95% CI, [1.44-3.36], p<0.001. Conclusion: Pre-EETI resuscitation is common among Canadian EM and CCM physicians. Most physicians use crystalloids pre-EETI as a resuscitation fluid, while few would give vasopressors. Physicians with CCM training were more likely to perform pre-EETI resuscitation.

Investigating Patterns of Automation and Growth Performance among Low Level Users of Manufacturing Automation

DEFF Research Database (Denmark)

Matthiesen, Rikke Vestergaard; Kromann, Lene

instrument with a new, innovative way of characterizing and measuring automation levels in the production process. The survey data is merged with elaborate Danish register data on economic performance, market, and worker characteristics. The data is available from 2000 to 2010 across a broad range......-movers; companies that develop their level of automation further and companies that remain on the 2005 level up until 2010. We compare the presence of drivers and enablers in the 5-year period leading up to 2005 and investigate patterns in growth performance on a range of economic indicators between the two groups....... However, the cross sectional nature of most studies prohibits analysis of direction; is growth and economic performance the driver of manufacturing technology investment or vice versa. Longitudinal data is required to study this. The present study analyses panel data obtained using a retrospective survey...

Validating Performance Level Descriptors (PLDs) for the AP® Environmental Science Exam

Science.gov (United States)

Reshetar, Rosemary; Kaliski, Pamela; Chajewski, Michael; Lionberger, Karen

2012-01-01

This presentation summarizes a pilot study conducted after the May 2011 administration of the AP Environmental Science Exam. The study used analytical methods based on scaled anchoring as input to a Performance Level Descriptor validation process that solicited systematic input from subject matter experts.

Physiological Indices of Stress Prior to and Following Total Knee Arthroplasty Predict the Occurrence of Severe Post-Operative Pain.

Science.gov (United States)

Cremeans-Smith, Julie K; Greene, Kenneth; Delahanty, Douglas L

2016-05-01

The severe pain and disability associated with osteoarthritis often motivate individuals to undergo arthroplastic surgery. However, a significant number of surgical patients continue to experience pain following surgery. Prior research has implicated both the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) in the sensitization of pain receptors and chronic pain conditions. This study uses a prospective, observational, cohort design to examine whether physiological stress responses before and after surgery could predict post-operative pain severity. Participants included 110 patients undergoing total knee arthroplasty. Physiological indices of stress included the measurement of catecholamine and cortisol levels in 15-hour urine samples collected prior to and 1 month following surgery, as well as in-hospital heart rate and blood pressure (before and after surgery), which were abstracted from medical records. Patients completed the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) [Bellamy et al., J Orthop Rheumatol 1: , 95 (1988)] 2.5 weeks prior to surgery and at a 3-month follow-up. Contrary to expectations, lower stress hormone levels at baseline were related to more severe post-operative pain. Data at later time points, however, supported our hypothesis: cardiovascular tone shortly before surgery and urinary levels of epinephrine 1 month following surgery were positively related to pain severity 3 months later. Results suggest that the occurrence of post-operative pain can be predicted on the basis of stress physiology prior to and following arthroplastic surgery. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cardiopulmonary exercise testing prior to myeloablative allo-SCT: a feasibility study.

Science.gov (United States)

Kelsey, C R; Scott, J M; Lane, A; Schwitzer, E; West, M J; Thomas, S; Herndon, J E; Michalski, M G; Horwitz, M E; Hennig, T; Jones, L W

2014-10-01

The feasibility of symptom-limited cardiopulmonary exercise testing (CPET) prior to allo-SCT was assessed in addition to the prognostic value of CPET-derived measures. CPET was performed prospectively on 21 patients with hematologic malignancies, with assessments of peak (for example, peak oxygen consumption, VO2peak) and submaximal (for example, ventilatory threshold (VT)) measures of cardiopulmonary function. No serious adverse events were observed during CPET procedures, with 95% of patients achieving criteria for a peak test. Mean VO2peak was 24.7±6.4 mL kg(-1 )min(-1) (range: 10.9-35.5), equivalent to 29%±17% below that of age-matched healthy controls. All patients proceeded with the conditioning regimen followed by allo-SCT. Median follow-up was 25 months. During this period, 11 (52.4%) patients died (n=6, relapsed disease; n=5, non-relapse mortality (NRM)); 9 patients (43%) developed pulmonary toxicity. In univariate analyses, both peak and submaximal markers of cardiopulmonary function were predictors of OS, pulmonary toxicity and NRM. For OS, the HR for VO2peak and VT were 0.89 (95% CI, 0.8-0.99, P=0.04) and 0.84 (95% CI, 0.71-0.98, P=0.03), respectively. In conclusion, CPET is safe and feasible prior to allo-SCT. Patients have marked impairments in cardiopulmonary function prior to allo-SCT. CPET-derived metrics may complement conventional measures to improve risk stratification.

Performance assessment overview for subseabed disposal of high level radioactive waste

International Nuclear Information System (INIS)

Klett, R.D.

1997-06-01

The Subseabed Disposal Project (SDP) was part of an international program that investigated the feasibility of high-level radioactive waste disposal in the deep ocean sediments. This report briefly describes the seven-step iterative performance assessment procedures used in this study and presents representative results of the last iteration. The results of the performance are compared to interim standards developed for the SDP, to other conceptual repositories, and to related metrics. The attributes, limitations, uncertainties, and remaining tasks in the SDP feasibility phase are discussed

The effects of low levels of dietary trace minerals on the plasma levels, faecal excretion health and performance of pigs in a hot African climate

Directory of Open Access Journals (Sweden)

M.H. Boma

2009-09-01

Full Text Available The present study was performed in order to evaluate the effects of lower than usual industry levels of dietary trace minerals on plasma levels, faecal excretion, performance, mortality and morbidity in growing-finishing pigs in a hot African climate. Group 1 (n =100 pigs received a diet with common industry levels of trace minerals. Group 2 (n =100 pigs received reduced dietary trace mineral levels but were fed the same basic diet as Group 1. Mortality, morbidity, pig performance and carcass measurements were evaluated. Two pigs in Group 1 and three pigs in Group 2 died. Thirteen pigs in Group 1 and 27 pigs in Group 2 were medically treated (P 0.05 by the dietary levels of these trace minerals. Plasma trace mineral concentrations were not affected by the dietary treatment.

30 CFR 872.29 - What are prior balance replacement funds?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... general funds of the United States Treasury that are otherwise unappropriated. Under section 411(h)(1) of...

Investigating the Effectiveness of Inquiry-Based Instruction on Students with Different Prior Knowledge and Reading Abilities

Science.gov (United States)

Wang, Jing-Ru; Wang, Yuh-Chao; Tai, Hsin-Jung; Chen, Wen-Ju

2010-01-01

This study examined the differential impacts of an inquiry-based instruction on conceptual changes across levels of prior knowledge and reading ability. The instrument emphasized four simultaneously important components: conceptual knowledge, reading ability, attitude toward science, and learning environment. Although the learning patterns and…

Prior Work and Educational Experience Are Not Associated With Successful Completion of a Master's-Level, Distance Education Midwifery Program.

Science.gov (United States)

Niemczyk, Nancy A; Cutts, Alison; Perlman, Dana B

2018-03-01

In order to increase and diversify the midwifery workforce, admissions criteria for midwifery education programs must not contain unnecessary barriers to entry. Once accepted, students need to successfully complete the program. Many admissions criteria commonly used in midwifery education programs in the United States are not evidence based and could be unnecessary barriers to education. The primary objective of this study was to identify factors known during the admission process that were related to successful completion or failure to complete a midwifery program educating both student nurse-midwives (SNMs) and student midwives (SMs); a secondary objective was to quantify reasons for program noncompletion. This master's-level, distance education program educates a diverse group of both SNMs and SMs. A pilot, retrospective cohort study examined all students matriculating at the program from fall 2012 on and scheduled to graduate by summer 2016 (N = 58). Demographic information, admissions information, academic records, and advising notes were reviewed. Reasons for noncompletion were identified, and characteristics were compared between students who did and did not complete the program. Program completion was not significantly associated with students' status as nurses prior to admission, labor and delivery nursing experience, length of nursing experience, nursing degree held, presence of children at home, working while in school, or undergraduate grade point average. Being a nurse, years of nursing experience, type of nursing degree, or labor and delivery nursing experience were not associated with completion of this midwifery program. © 2018 by the American College of Nurse-Midwives.

Prior opportunities to identify abuse in children with abusive head trauma.

Science.gov (United States)

Letson, Megan M; Cooper, Jennifer N; Deans, Katherine J; Scribano, Philip V; Makoroff, Kathi L; Feldman, Kenneth W; Berger, Rachel P

2016-10-01

Infants with minor abusive injuries are at risk for more serious abusive injury, including abusive head trauma (AHT). Our study objective was to determine if children with AHT had prior opportunities to detect abuse and to describe the opportunities. All AHT cases from 7/1/2009 to 12/31/2011 at four tertiary care children's hospitals were included. A prior opportunity was defined as prior evaluation by either a medical or child protective services (CPS) professional when the symptoms and/or referral could be consistent with abuse but the diagnosis was not made and/or an alternate explanation was given and accepted. Two-hundred-thirty-two children with AHT were identified; median age (IQR) was 5.40 (3.30, 14.60) months. Ten percent (22/232) died. Of the 232 patients diagnosed with AHT, 31% (n=73) had a total of 120 prior opportunities. Fifty-nine children (25%) had at least one prior opportunity to identify abuse in a medical setting, representing 98 prior opportunities. An additional 14 (6%) children had 22 prior opportunities through previous CPS involvement. There were no differences between those with and without a prior opportunity based on age, gender, race, insurance, mortality, or institution. Children with prior opportunities in a medical setting were more likely to have chronic subdural hemorrhage (48 vs. 17%, p<0.01) and healing fractures (31 vs. 19%, p=0.05). The most common prior opportunities included vomiting 31.6% (38/120), prior CPS contact 20% (24/120), and bruising 11.7% (14/120). Improvements in earlier recognition of AHT and subsequent intervention might prevent additional injuries and reduce mortality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Variational segmentation problems using prior knowledge in imaging and vision

DEFF Research Database (Denmark)

Fundana, Ketut

This dissertation addresses variational formulation of segmentation problems using prior knowledge. Variational models are among the most successful approaches for solving many Computer Vision and Image Processing problems. The models aim at finding the solution to a given energy functional defined......, prior knowledge is needed to obtain the desired solution. The introduction of shape priors in particular, has proven to be an effective way to segment objects of interests. Firstly, we propose a prior-based variational segmentation model to segment objects of interest in image sequences, that can deal....... Many objects have high variability in shape and orientation. This often leads to unsatisfactory results, when using a segmentation model with single shape template. One way to solve this is by using more sophisticated shape models. We propose to incorporate shape priors from a shape sub...

A Bayesian hierarchical model with novel prior specifications for estimating HIV testing rates.

Science.gov (United States)

An, Qian; Kang, Jian; Song, Ruiguang; Hall, H Irene

2016-04-30

Human immunodeficiency virus (HIV) infection is a severe infectious disease actively spreading globally, and acquired immunodeficiency syndrome (AIDS) is an advanced stage of HIV infection. The HIV testing rate, that is, the probability that an AIDS-free HIV infected person seeks a test for HIV during a particular time interval, given no previous positive test has been obtained prior to the start of the time, is an important parameter for public health. In this paper, we propose a Bayesian hierarchical model with two levels of hierarchy to estimate the HIV testing rate using annual AIDS and AIDS-free HIV diagnoses data. At level one, we model the latent number of HIV infections for each year using a Poisson distribution with the intensity parameter representing the HIV incidence rate. At level two, the annual numbers of AIDS and AIDS-free HIV diagnosed cases and all undiagnosed cases stratified by the HIV infections at different years are modeled using a multinomial distribution with parameters including the HIV testing rate. We propose a new class of priors for the HIV incidence rate and HIV testing rate taking into account the temporal dependence of these parameters to improve the estimation accuracy. We develop an efficient posterior computation algorithm based on the adaptive rejection metropolis sampling technique. We demonstrate our model using simulation studies and the analysis of the national HIV surveillance data in the USA. Copyright © 2015 John Wiley & Sons, Ltd.

Detection of architectural distortion in prior screening mammograms using Gabor filters, phase portraits, fractal dimension, and texture analysis

International Nuclear Information System (INIS)

Rangayyan, Rangaraj M.; Prajna, Shormistha; Ayres, Fabio J.; Desautels, J.E.L.

2008-01-01

Mammography is a widely used screening tool for the early detection of breast cancer. One of the commonly missed signs of breast cancer is architectural distortion. The purpose of this study is to explore the application of fractal analysis and texture measures for the detection of architectural distortion in screening mammograms taken prior to the detection of breast cancer. A method based on Gabor filters and phase portrait analysis was used to detect initial candidates for sites of architectural distortion. A total of 386 regions of interest (ROIs) were automatically obtained from 14 ''prior mammograms'', including 21 ROIs related to architectural distortion. From the corresponding set of 14 ''detection mammograms'', 398 ROIs were obtained, including 18 related to breast cancer. For each ROI, the fractal dimension and Haralick's texture features were computed. The fractal dimension of the ROIs was calculated using the circular average power spectrum technique. The average fractal dimension of the normal (false-positive) ROIs was significantly higher than that of the ROIs with architectural distortion (p = 0.006). For the ''prior mammograms'', the best receiver operating characteristics (ROC) performance achieved, in terms of the area under the ROC curve, was 0.80 with a Bayesian classifier using four features including fractal dimension, entropy, sum entropy, and inverse difference moment. Analysis of the performance of the methods with free-response receiver operating characteristics indicated a sensitivity of 0.79 at 8.4 false positives per image in the detection of sites of architectural distortion in the ''prior mammograms''. Fractal dimension offers a promising way to detect the presence of architectural distortion in prior mammograms. (orig.)

Hierarchical Effects of School-, Classroom-, and Student-Level Factors on the Science Performance of Eighth-Grade Taiwanese Students

Science.gov (United States)

Tsai, Liang-Ting; Yang, Chih-Chien

2015-05-01

This study was conducted to understand the effect of student-, classroom-, and school-level factors on the science performance of 8th-grade Taiwanese students in the Trends in International Mathematics and Science Study (TIMSS) 2011 by using multilevel analysis. A total of 5,042 students from 153 classrooms of 150 schools participated in the TIMSS 2011 study, in which they were required to complete questionnaires. A 3-level multilevel analysis was used to assess the influence of factors at 3 levels on the science performance of 8th-grade Taiwanese students. The results showed that the provision of education resources at home, teachers' level of education, and school climate were the strongest predictor of science performance at the student, classroom, and school level, respectively. It was concluded that the science performance of 8th-grade Taiwanese students is driven largely by individual factors. Classroom-level factors accounted for a smaller proportion of the total variance in science performance than did school-level factors.

The Prior Can Often Only Be Understood in the Context of the Likelihood

Directory of Open Access Journals (Sweden)

Andrew Gelman

2017-10-01

Full Text Available A key sticking point of Bayesian analysis is the choice of prior distribution, and there is a vast literature on potential defaults including uniform priors, Jeffreys’ priors, reference priors, maximum entropy priors, and weakly informative priors. These methods, however, often manifest a key conceptual tension in prior modeling: a model encoding true prior information should be chosen without reference to the model of the measurement process, but almost all common prior modeling techniques are implicitly motivated by a reference likelihood. In this paper we resolve this apparent paradox by placing the choice of prior into the context of the entire Bayesian analysis, from inference to prediction to model evaluation.

Performance of engineered barriers for low-level waste

International Nuclear Information System (INIS)

Taplin, D.; Claridge, F.B.

1987-09-01

Geotechnical Resources Ltd., in association with Komex Consultants Ltd., was retained to collect, synthesize and evaluate the available information on the long term performance of engineered barriers for low-level radioactive wastes disposed in Canada. Literature was researched from Canadian, United States and European sources. A variety of barrier materials were assessed in the study and included natural clays, concrete and cement, metals, bentonite-sand admixes, bitumen and bituminous admixes, soil cement and polymeric membranes. The generalized geological and geotechnical conditions encountered within the soil and rock host media currently under consideration for disposal sites in southern Ontario were also summarized. Both internal barriers, or buffers, to immobilize the waste material and reduce radionuclide mobility, as well as external barriers to limit the migration of contaminants were examined. Microbial activities within the waste forms were analyzed, including cellulose degradation, methanogenesis and bicarbonate and organic reactions. Microbial interactions with the various engineered barrier materials under consideration were also assessed. Finally, the anticipated long term performances of the respective barrier materials under consideration were evaluated, along with the general suitability of the geological host media being proposed for disposal sites

Quantum steganography using prior entanglement

International Nuclear Information System (INIS)

Mihara, Takashi

2015-01-01

Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography

Quantum steganography using prior entanglement

Energy Technology Data Exchange (ETDEWEB)

Mihara, Takashi, E-mail: mihara@toyo.jp

2015-06-05

Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography.

Crowdsourcing prior information to improve study design and data analysis.

Directory of Open Access Journals (Sweden)

Jeffrey S Chrabaszcz

Full Text Available Though Bayesian methods are being used more frequently, many still struggle with the best method for setting priors with novel measures or task environments. We propose a method for setting priors by eliciting continuous probability distributions from naive participants. This allows us to include any relevant information participants have for a given effect. Even when prior means are near-zero, this method provides a principle way to estimate dispersion and produce shrinkage, reducing the occurrence of overestimated effect sizes. We demonstrate this method with a number of published studies and compare the effect of different prior estimation and aggregation methods.

Ractopamine levels on performance, carcass characteristics and quality of pig meat

Directory of Open Access Journals (Sweden)

Cesar Augusto Pospissil Garbossa

2013-05-01

Full Text Available This study evaluated the effect of ractopamine (RAC on the performance of finishing pigs and the meat quality of these animals. Seventy crossbred pigs (35 barrows and 35 females selected for high gain of lean meat, with initial weight of 77.1±0.32 kg were distributed in randomized blocks with five treatments (0, 5, 10, 15, and 20 ppm RAC in the diet and seven replications during 28 days. The experimental unit was represented by a male and a female pig. Regarding the performance variables, there was a linear increase in final weight with increasing levels of RAC, as well as in average daily weight gain. An improvement in feed conversion was observed for animals fed RAC, and the optimal level - estimated by the LRP model - was ~ 5 ppm. For feed intake, no significant effect on intake of digestible lysine and energy intake was observed. Carcass yield responses increased linearly with the RAC dose. Ash content, color component b* and loss drip linearly decreased with increasing doses of RAC. There was also a significant difference in the percentage of ether extract and crude protein in the loin, and treatment with 20 ppm RAC showed a lower amount of protein and larger amounts of lipids. Moisture content, color component L*, weight loss by cooking and defrosting, shear force and pH were not affected by the treatment. Concerning the lipid oxidation, there was no effect of RAC on the concentration of TBARS (thiobarbituric acid reactive substances under cooling and under freezing. Thus, all ractopamine levels improve performance compared with control and do not negatively affect the quality of fresh, chilled or frozen pig meat.

Investigation of Remedial Education Course Scores as a Predictor of Introduction-Level Course Performances

Science.gov (United States)

Ulmer, Ward; Means, Darris R.; Cawthon, Tony W.; Kristensen, Sheryl A.

2016-01-01

This study explores whether performance in remedial English and remedial math is a predictor of success in a college-level introduction English or college-level math class; and whether demographic variables increase the likelihood of remedial English and remedial math as a predictor of success in a college-level introduction English or…

Formulating informative, data-based priors for failure probability estimation in reliability analysis

International Nuclear Information System (INIS)

Guikema, Seth D.

2007-01-01

Priors play an important role in the use of Bayesian methods in risk analysis, and using all available information to formulate an informative prior can lead to more accurate posterior inferences. This paper examines the practical implications of using five different methods for formulating an informative prior for a failure probability based on past data. These methods are the method of moments, maximum likelihood (ML) estimation, maximum entropy estimation, starting from a non-informative 'pre-prior', and fitting a prior based on confidence/credible interval matching. The priors resulting from the use of these different methods are compared qualitatively, and the posteriors are compared quantitatively based on a number of different scenarios of observed data used to update the priors. The results show that the amount of information assumed in the prior makes a critical difference in the accuracy of the posterior inferences. For situations in which the data used to formulate the informative prior is an accurate reflection of the data that is later observed, the ML approach yields the minimum variance posterior. However, the maximum entropy approach is more robust to differences between the data used to formulate the prior and the observed data because it maximizes the uncertainty in the prior subject to the constraints imposed by the past data

Finding A Minimally Informative Dirichlet Prior Using Least Squares

International Nuclear Information System (INIS)

Kelly, Dana

2011-01-01

In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straightforward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson λ, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in the form of a standard distribution (e.g., beta, gamma), and so a beta distribution is used as an approximation in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial model for common-cause failure, must be estimated from data that are often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.

Construction and test of the PRIOR proton microscope; Aufbau und Test des Protonenmikroskops PRIOR

Energy Technology Data Exchange (ETDEWEB)

Lang, Philipp-Michael

2015-01-15

The study of High Energy Density Matter (HEDM) in the laboratory makes great demands on the diagnostics because these states can usually only be created for a short time and usual diagnostic techniques with visible light or X-rays come to their limit because of the high density. The high energy proton radiography technique that was developed in the 1990s at the Los Alamos National Laboratory is a very promising possibility to overcome those limits so that one can measure the density of HEDM with high spatial and time resolution. For this purpose the proton microscope PRIOR (Proton Radiography for FAIR) was set up at GSI, which not only reproduces the image, but also magnifies it by a factor of 4.2 and thereby penetrates matter with a density up to 20 g/cm{sup 2}. Straightaway a spatial resolution of less than 30 μm and a time resolution on the nanosecond scale was achieved. This work describes details to the principle, design and construction of the proton microscope as well as first measurements and simulations of essential components like magnetic lenses, a collimator and a scintillator screen. For the latter one it was possible to show that plastic scintillators can be used as converter as an alternative to the slower but more radiation resistant crystals, so that it is possible to reach a time resolution of 10 ns. Moreover the characteristics were investigated for the system at the commissioning in April 2014. Also the changes in the magnetic field due to radiation damage were studied. Besides that an overview about future applications is given. First experiments with Warm Dense Matter created by using a Pulsed Power Setup have already been performed. Furthermore the promising concept of combining proton radiography with particle therapy has been investigated in context of the PaNTERA project. An outlook on the possibilities with future experiments at the FAIR accelerator facility is given as well. Because of higher beam intensity an energy one can expect even