[Processing acoustically presented time intervals of seconds duration: an expression of the phonological loop of the working memory?].

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Grube, D

1996-01-01

Working memory has been proposed to contribute to the processing of time, rhythm and music; the question which component of working memory is involved is under discussion. The present study tests the hypothesis that the phonological loop component (Baddeley, 1986) is involved in the processing of auditorily presented time intervals of a few seconds' duration. Typical effects well known with short-term retention of verbal material could be replicated with short-term retention of temporal intervals: The immediate reproduction of time intervals was impaired under conditions of background music and articulatory suppression. Neither the accuracy nor the speed of responses in a (non-phonological) mental rotation task were diminished under these conditions. Processing of auditorily presented time intervals seems to be constrained by the capacity of the phonological loop: The immediate serial recall of sequences of time intervals was shown to be related to the immediate serial recall of words (memory span). The results confirm the notion that working memory resources, and especially the phonological loop component, underlie the processing of auditorily presented temporal information with a duration of a few seconds.

Impact of sampling interval in training data acquisition on intrafractional predictive accuracy of indirect dynamic tumor-tracking radiotherapy.

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Mukumoto, Nobutaka; Nakamura, Mitsuhiro; Akimoto, Mami; Miyabe, Yuki; Yokota, Kenji; Matsuo, Yukinori; Mizowaki, Takashi; Hiraoka, Masahiro

2017-08-01

To explore the effect of sampling interval of training data acquisition on the intrafractional prediction error of surrogate signal-based dynamic tumor-tracking using a gimbal-mounted linac. Twenty pairs of respiratory motions were acquired from 20 patients (ten lung, five liver, and five pancreatic cancer patients) who underwent dynamic tumor-tracking with the Vero4DRT. First, respiratory motions were acquired as training data for an initial construction of the prediction model before the irradiation. Next, additional respiratory motions were acquired for an update of the prediction model due to the change of the respiratory pattern during the irradiation. The time elapsed prior to the second acquisition of the respiratory motion was 12.6 ± 3.1 min. A four-axis moving phantom reproduced patients' three dimensional (3D) target motions and one dimensional surrogate motions. To predict the future internal target motion from the external surrogate motion, prediction models were constructed by minimizing residual prediction errors for training data acquired at 80 and 320 ms sampling intervals for 20 s, and at 500, 1,000, and 2,000 ms sampling intervals for 60 s using orthogonal kV x-ray imaging systems. The accuracies of prediction models trained with various sampling intervals were estimated based on training data with each sampling interval during the training process. The intrafractional prediction errors for various prediction models were then calculated on intrafractional monitoring images taken for 30 s at the constant sampling interval of a 500 ms fairly to evaluate the prediction accuracy for the same motion pattern. In addition, the first respiratory motion was used for the training and the second respiratory motion was used for the evaluation of the intrafractional prediction errors for the changed respiratory motion to evaluate the robustness of the prediction models. The training error of the prediction model was 1.7 ± 0.7 mm in 3D for all sampling

Sample size planning for composite reliability coefficients: accuracy in parameter estimation via narrow confidence intervals.

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Terry, Leann; Kelley, Ken

2012-11-01

Composite measures play an important role in psychology and related disciplines. Composite measures almost always have error. Correspondingly, it is important to understand the reliability of the scores from any particular composite measure. However, the point estimates of the reliability of composite measures are fallible and thus all such point estimates should be accompanied by a confidence interval. When confidence intervals are wide, there is much uncertainty in the population value of the reliability coefficient. Given the importance of reporting confidence intervals for estimates of reliability, coupled with the undesirability of wide confidence intervals, we develop methods that allow researchers to plan sample size in order to obtain narrow confidence intervals for population reliability coefficients. We first discuss composite reliability coefficients and then provide a discussion on confidence interval formation for the corresponding population value. Using the accuracy in parameter estimation approach, we develop two methods to obtain accurate estimates of reliability by planning sample size. The first method provides a way to plan sample size so that the expected confidence interval width for the population reliability coefficient is sufficiently narrow. The second method ensures that the confidence interval width will be sufficiently narrow with some desired degree of assurance (e.g., 99% assurance that the 95% confidence interval for the population reliability coefficient will be less than W units wide). The effectiveness of our methods was verified with Monte Carlo simulation studies. We demonstrate how to easily implement the methods with easy-to-use and freely available software. ©2011 The British Psychological Society.

Accuracy of 24-h whole-body (skeletal) retention of diphosphonate measurements

International Nuclear Information System (INIS)

Fogelman, I.; Scullion, J.E.; Bessent, R.; Cuthbert, G.F.

1982-01-01

The 24-h whole-body retention (WBR) of diphosphonate was a valuable test for the assessment of skeletal metabolism. However, the reproducibility, accuracy and possible sources of error in WBR measurements have not previously been studied. In 21 paired studies the technique was found to be highly reproducible (r=0.998, R<0.0001). The coefficient of variation for whole-body counts on day 1 was 0.1% and on day 2, 1.1%. A phantom was used to assess the possible error introduced by redistribution of tracer. The net whole-body count of the phantom representing the 24-h distribution was 98% of that of a uniform phantom. Ten subjects were counted twice within a few minutes to study the effect of repositioning, and showed a mean difference between counts of only 0.8%. Eleven subjects with traumatic fractures were studied to assess the possible contribution of focal lesions to WBR. It was found that nine subjects had normal values for WBR, while two had minimally elevated results. Twenty patients with renal disease but no apparent skeletal disease were also studied to assess the possible contribution of soft-tissue retention to WBR. A significant correlation between serum creatinine and WBR was found (r=0.72, P<0.001). However WBR results were always normal when serum creatinine values were <130 μmol/1. It is suggested that WBR measurement is accurate and the technique is hgihly reproducible. The presence of a focal lesion is unlikely to affect a WBR result significantly and if serum creatinine is the normal range then WBR can be assumed to reflect skeletal metabolism without further concern as to renal function. (orig.)

The contributions of encoding, retention, and recall to the Hebb effect.

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Oberauer, Klaus; Meyer, Nadine

2009-10-01

The article reports an experiment testing whether the Hebb repetition effect-the gradual improvement of immediate serial recall when the same list is repeated several times-depends on overt recall of the repeated lists. Previous reports which suggest that recall is critical confound the recall manipulation with retention interval. The present experiment orthogonally varies retention interval (0 or 9 s) and whether the list is to be recalled after the retention interval. Hebb repetition learning is assessed in a final test phase. A repetition effect was obtained in all four experimental conditions; it was larger for recalled than non-recalled lists, whereas retention interval had no effect. The results show that encoding is sufficient to generate cumulative long-term learning, which is strengthened by recall. Rehearsal, if it takes place in the retention interval at all, does not have the same effect on long-term learning as overt recall.

Inactivation of the Medial-Prefrontal Cortex Impairs Interval Timing Precision, but Not Timing Accuracy or Scalar Timing in a Peak-Interval Procedure in Rats

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Catalin V. Buhusi

2018-06-01

Full Text Available Motor sequence learning, planning and execution of goal-directed behaviors, and decision making rely on accurate time estimation and production of durations in the seconds-to-minutes range. The pathways involved in planning and execution of goal-directed behaviors include cortico-striato-thalamo-cortical circuitry modulated by dopaminergic inputs. A critical feature of interval timing is its scalar property, by which the precision of timing is proportional to the timed duration. We examined the role of medial prefrontal cortex (mPFC in timing by evaluating the effect of its reversible inactivation on timing accuracy, timing precision and scalar timing. Rats were trained to time two durations in a peak-interval (PI procedure. Reversible mPFC inactivation using GABA agonist muscimol resulted in decreased timing precision, with no effect on timing accuracy and scalar timing. These results are partly at odds with studies suggesting that ramping prefrontal activity is crucial to timing but closely match simulations with the Striatal Beat Frequency (SBF model proposing that timing is coded by the coincidental activation of striatal neurons by cortical inputs. Computer simulations indicate that in SBF, gradual inactivation of cortical inputs results in a gradual decrease in timing precision with preservation of timing accuracy and scalar timing. Further studies are needed to differentiate between timing models based on coincidence detection and timing models based on ramping mPFC activity, and clarify whether mPFC is specifically involved in timing, or more generally involved in attention, working memory, or response selection/inhibition.

Confidence intervals for modeling anthocyanin retention in grape pomace during nonisothermal heating.

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Mishra, D K; Dolan, K D; Yang, L

2008-01-01

Degradation of nutraceuticals in low- and intermediate-moisture foods heated at high temperature (>100 degrees C) is difficult to model because of the nonisothermal condition. Isothermal experiments above 100 degrees C are difficult to design because they require high pressure and small sample size in sealed containers. Therefore, a nonisothermal method was developed to estimate the thermal degradation kinetic parameter of nutraceuticals and determine the confidence intervals for the parameters and the predicted Y (concentration). Grape pomace at 42% moisture content (wb) was heated in sealed 202 x 214 steel cans in a steam retort at 126.7 degrees C for > 30 min. Can center temperature was measured by thermocouple and predicted using Comsol software. Thermal conductivity (k) and specific heat (C(p)) were estimated as quadratic functions of temperature using Comsol and nonlinear regression. The k and C(p) functions were then used to predict temperature inside the grape pomace during retorting. Similar heating experiments were run at different time-temperature treatments from 8 to 25 min for kinetic parameter estimation. Anthocyanin concentration in the grape pomace was measured using HPLC. Degradation rate constant (k(110 degrees C)) and activation energy (E(a)) were estimated using nonlinear regression. The thermophysical properties estimates at 100 degrees C were k = 0.501 W/m degrees C, Cp= 3600 J/kg and the kinetic parameters were k(110 degrees C)= 0.0607/min and E(a)= 65.32 kJ/mol. The 95% confidence intervals for the parameters and the confidence bands and prediction bands for anthocyanin retention were plotted. These methods are useful for thermal processing design for nutraceutical products.

Impact of different conditions on accuracy of five rules for principal components retention

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Zorić Aleksandar

2013-01-01

Full Text Available Polemics about criteria for nontrivial principal components are still present in the literature. Finding of a lot of papers, is that the most frequently used Guttman Kaiser’s criterion has very poor performance. In the last three years some new criteria were proposed. In this Monte Carlo experiment we aimed to investigate the impact that sample size, number of analyzed variables, number of supposed factors and proportion of error variance have on the accuracy of analyzed criteria for principal components retention. We compared the following criteria: Bartlett’s χ2 test, Horn’s Parallel Analysis, Guttman-Kaiser’s eigenvalue over one, Velicer’s MAP and CHull originally proposed by Ceulemans & Kiers. Factors were systematically combined resulting in 690 different combinations. A total of 138,000 simulations were performed. Novelty in this research is systematic variation of the error variance. Performed simulations showed that, in favorable research conditions, all analyzed criteria work properly. Bartlett’s and Horns criterion expressed the robustness in most of analyzed situations. Velicer’s MAP had the best accuracy in situations with small number of subjects and high number of variables. Results confirm earlier findings of Guttman-Kaiser’s criterion having the worse performance.

Uremic retention solute indoxyl sulfate level is associated with prolonged QTc interval in early CKD patients.

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Wei-Hua Tang

Full Text Available Total mortality and sudden cardiac death is highly prevalent in patients with chronic kidney disease (CKD. In CKD patients, the protein-bound uremic retention solute indoxyl sulfate (IS is independently associated with cardiovascular disease. However, the underlying mechanisms of this association have yet to be elucidated. The relationship between IS and cardiac electrocardiographic parameters was investigated in a prospective observational study among early CKD patients. IS arrhythmogenic effect was evaluated by in vitro cardiomyocyte electrophysiological study and mathematical computer simulation. In a cohort of 100 early CKD patients, patients with corrected QT (QTc prolongation had higher IS levels. Furthermore, serum IS level was independently associated with prolonged QTc interval. In vitro, the delay rectifier potassium current (IK was found to be significantly decreased after the treatment of IS in a dose-dependent manner. The modulation of IS to the IK was through the regulation of the major potassium ion channel protein Kv 2.1 phosphorylation. In a computer simulation, the decrease of IK by IS could prolong the action potential duration (APD and induce early afterdepolarization, which is known to be a trigger mechanism of lethal ventricular arrhythmias. In conclusion, serum IS level is independently associated with the prolonged QTc interval in early CKD patients. IS down-regulated IK channel protein phosphorylation and the IK current activity that in turn increased the cardiomyocyte APD and QTc interval in vitro and in the computer ORd model. These findings suggest that IS may play a role in the development of arrhythmogenesis in CKD patients.

Decomposing the interaction between retention interval and study/test practice: the role of retrievability.

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Jang, Yoonhee; Wixted, John T; Pecher, Diane; Zeelenberg, René; Huber, David E

2012-01-01

Even without feedback, test practice enhances delayed performance compared to study practice, but the size of the effect is variable across studies. We investigated the benefit of testing, separating initially retrievable items from initially nonretrievable items. In two experiments, an initial test determined item retrievability. Retrievable or nonretrievable items were subsequently presented for repeated study or test practice. Collapsing across items, in Experiment 1, we obtained the typical cross-over interaction between retention interval and practice type. For retrievable items, however, the cross-over interaction was quantitatively different, with a small study benefit for an immediate test and a larger testing benefit after a delay. For nonretrievable items, there was a large study benefit for an immediate test, but one week later there was no difference between the study and test practice conditions. In Experiment 2, initially nonretrievable items were given additional study followed by either an immediate test or even more additional study, and one week later performance did not differ between the two conditions. These results indicate that the effect size of study/test practice is due to the relative contribution of retrievable and nonretrievable items.

Retrieval practice after multiple context changes, but not long retention intervals, reduces the impact of a final context change on instrumental behavior.

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Trask, Sydney; Bouton, Mark E

2018-06-01

Recent evidence from this laboratory suggests that a context switch after operant learning consistently results in a decrement in responding. One way to reduce this decrement is to train the response in multiple contexts. One interpretation of this result, rooted in stimulus sampling theory, is that conditioning of a greater number of common stimulus elements arising from more contexts causes better generalization to new contexts. An alternative explanation is that each change of context causes more effortful retrieval, and practice involving effortful retrieval results in learning that is better able to transfer to new situations. The current experiments were designed to differentiate between these two explanations for the first time in an animal learning and memory task. Experiment 1 demonstrated that the detrimental impact of a context change on an instrumental nose-poking response can be reduced by training the response in multiple contexts. Experiment 2 then found that a training procedure which inserted extended retention intervals between successive training sessions did not reduce the detrimental impact of a final context change. This occurred even though the inserted retention intervals had a detrimental impact on responding (and, thus, presumably retrieval) similar to the effect that context switches had in Experiment 1. Together, the results suggest that effortful retrieval practice may not be sufficient to reduce the negative impact of a context change on instrumental behavior. A common elements explanation which supposes that physical and temporal contextual cues do not overlap may account for the findings more readily.

The robustness of false memory for emotional pictures.

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Bessette-Symons, Brandy A

2018-02-01

Emotional material is commonly reported to be more accurately recognised; however, there is substantial evidence of increased false alarm rates (FAR) for emotional material and several reports of stronger influences on response bias than accuracy. This pattern is more frequently reported for words than pictures. Research on the mechanisms underlying bias differences has mostly focused on word lists under short retention intervals. This article presents four series of experiments examining recognition memory for emotional pictures while varying arousal and the control over the content of the pictures at two retention intervals, and one study measuring the relatedness of the series picture sets. Under the shorter retention interval, emotion increased false alarms and reduced accuracy. Under the longer retention interval emotion increased hit rates and FAR, resulting in reduced accuracy and/or bias. At both retention intervals, the pattern of valence effects differed based on the arousal associated with the picture sets. Emotional pictures were found to be more related than neutral pictures in each set; however, the influence of relatedness alone does not provide an adequate explanation for all emotional differences. The results demonstrate substantial emotional differences in picture recognition that vary based on valence, arousal and retention interval.

A strategic approach to employee retention.

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Gering, John; Conner, John

2002-11-01

A sound retention strategy should incorporate a business plan, a value proposition, progress measures, and management influences. The business plan will indicate whether a healthcare organization will achieve a return on investment for its effort. A value proposition will showcase an organization's strengths and differentiate it from its competitors. Measuring progress toward meeting retention goals at regular intervals will help keep an organization on track. The best managers require accountability, rewarding employees for their successes and taking corrective action as necessary. Retention rate targets must be at a level that will achieve a competitive advantage in the served market.

Retention of autobiographical memories: an Internet-based diary study

NARCIS (Netherlands)

Kristo, G.; Janssen, S.M.J.; Murre, J.M.J.

2009-01-01

In this online study we examined the retention of recent personal events using an Internet-based diary technique. Each participant (N=878) recorded on a website one recent personal event and was contacted after a retention interval that ranged between 2 and 46 days. We investigated how well the

Accuracy of some simple models for predicting particulate interception and retention in agricultural systems

International Nuclear Information System (INIS)

Pinder, J.E. III; McLeod, K.W.; Adriano, D.C.

1989-01-01

The accuracy of three radionuclide transfer models for predicting the interception and retention of airborne particles by agricultural crops was tested using Pu-bearing aerosols released to the atmosphere from nuclear fuel facilities on the U.S. Department of Energy's Savannah River Plant, near Aiken, SC. The models evaluated were: (1) NRC, the model defined in U.S. Nuclear Regulatory Guide 1.109; (2) FOOD, a model similar to the NRC model that also predicts concentrations in grains; and (3) AGNS, a model developed from the NRC model for the southeastern United States. Plutonium concentrations in vegetation and grain were predicted from measured deposition rates and compared to concentrations observed in the field. Crops included wheat, soybeans, corn and cabbage. Although predictions of the three models differed by less than a factor of 4, they showed different abilities to predict concentrations observed in the field. The NRC and FOOD models consistently underpredicted the observed Pu concentrations for vegetation. The AGNS model was a more accurate predictor of Pu concentrations for vegetation. Both the FOOD and AGNS models accurately predicted the Pu concentrations for grains

Novel word retention in sequential bilingual children.

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Kan, Pui Fong

2014-03-01

Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after either a 2-month or a 4-month delay. Results showed that children retained more words in L1 than in L2 for both of the retention interval conditions. In addition, children's word retention was associated with their existing language knowledge and their fast-mapping performance within and across language. The patterns of association, however, were different between L1 and L2. These findings suggest that children's word retention might be related to the interactions of various components that are operating within a dynamic system.

Comparisons of methods for calculating retention and separation of chromatographic peaks

International Nuclear Information System (INIS)

Pauls, R.E.; Rogers, L.B.

1976-09-01

The accuracy and precision of calculating retention times from means and peak maxima have been examined using an exponentially modified Gaussian as a model for tailed chromotographic peaks. At different levels of random noise, retention times could be determined with nearly the same precision using either the mean or maximum. However, the accuracies and precisions of the maxima were affected by the number of points used in the digital smooth and by the number of points recorded per unit of standard deviation. For two peaks of similar shape, consistency in the selection of points should usually permit differences in retention to be determined accurately and with approximately the same precision using maxima, means, or half-heights on the leading side of the peak

The diagnostic accuracy of TCD for intracranial arterial stenosis/occlusion in patients with acute ischemic stroke: the importance of time interval between detection of TCD and CTA.

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Guan, Jingxia; Zhou, Qin; Ouyang, Huangqing; Zhang, Shaofeng; Lu, Zuneng

2013-11-01

To evaluate prospectively the diagnostic accuracy of transcranial doppler (TCD) as an additional screening tool for intracranial arterial steno-occlusive disease against computed tomography angiography (CTA) in patients with acute ischemic stroke (AIS) if both are performed in a short time interval. Between July 2011 and May 2012, 128 patients who were hospitalized within 24 hours of symptom onset and fulfilled the criteria for the clinical diagnosis of AIS were enrolled. Bedside detection of TCD was accomplished immediately after admission. High-resolution brain CTA was performed within 3 hours after the completion of TCD and the images were interpreted by a neuroradiologist blinded to TCD findings. The accuracy parameters of TCD against CTA were calculated after computation of true-positive, false-positive, true negative, and false-negative values. Among the 128 patients, there were 68 males and 60 females, aged 61.4 ± 17.5 years. The mean time interval between the detection of TCD and CTA was 89.7 (77.8) minutes. In 65% of patients, both examinations were performed with less than a half-hour interval between them. The diagnostic accuracy of TCD for different arteries showed slight distinction. Transcranial doppler demonstrated the most accurate diagnosis for middle cerebral artery (MCA), where TCD showed 35 true-positive, 0 false-negative, 1 false-positive, and 92 true-negative studies compared with CTA. Furthermore, elevated MCA velocities on TCD correlated well with the severity of intracranial stenosis detected on CTA. Vertebral artery (VA) is one of the arteries with the lowest sensitivity for TCD diagnosis (sensitivity 63.4%, specificity 96.5%, positive predictive value (PPV) 89.6%, negative predictive value (NPV) 84.8%, and accuracy 85.9%). In 20 cases (15.6%), TCD showed findings complementary to CTA (real-time embolization, collateral flow patterns, and steal phenomenon). Transcranial doppler shows high diagnostic accuracy against CTA if both are

Increasing accuracy in the interval analysis by the improved format of interval extension based on the first order Taylor series

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Li, Yi; Xu, Yan Long

2018-05-01

When the dependence of the function on uncertain variables is non-monotonic in interval, the interval of function obtained by the classic interval extension based on the first order Taylor series will exhibit significant errors. In order to reduce theses errors, the improved format of the interval extension with the first order Taylor series is developed here considering the monotonicity of function. Two typical mathematic examples are given to illustrate this methodology. The vibration of a beam with lumped masses is studied to demonstrate the usefulness of this method in the practical application, and the necessary input data of which are only the function value at the central point of interval, sensitivity and deviation of function. The results of above examples show that the interval of function from the method developed by this paper is more accurate than the ones obtained by the classic method.

Auditory proactive interference in monkeys: the roles of stimulus set size and intertrial interval.

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Bigelow, James; Poremba, Amy

2013-09-01

We conducted two experiments to examine the influences of stimulus set size (the number of stimuli that are used throughout the session) and intertrial interval (ITI, the elapsed time between trials) in auditory short-term memory in monkeys. We used an auditory delayed matching-to-sample task wherein the animals had to indicate whether two sounds separated by a 5-s retention interval were the same (match trials) or different (nonmatch trials). In Experiment 1, we randomly assigned stimulus set sizes of 2, 4, 8, 16, 32, 64, or 192 (trial-unique) for each session of 128 trials. Consistent with previous visual studies, overall accuracy was consistently lower when smaller stimulus set sizes were used. Further analyses revealed that these effects were primarily caused by an increase in incorrect "same" responses on nonmatch trials. In Experiment 2, we held the stimulus set size constant at four for each session and alternately set the ITI at 5, 10, or 20 s. Overall accuracy improved when the ITI was increased from 5 to 10 s, but it was the same across the 10- and 20-s conditions. As in Experiment 1, the overall decrease in accuracy during the 5-s condition was caused by a greater number of false "match" responses on nonmatch trials. Taken together, Experiments 1 and 2 showed that auditory short-term memory in monkeys is highly susceptible to proactive interference caused by stimulus repetition. Additional analyses of the data from Experiment 1 suggested that monkeys may make same-different judgments on the basis of a familiarity criterion that is adjusted by error-related feedback.

Rapid measurement of indocyanine green retention by pulse spectrophotometry: a validation study in 70 patients with Child-Pugh A cirrhosis before hepatectomy for hepatocellular carcinoma.

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Cheung, Tan To; Chan, See Ching; Chok, Kenneth S H; Chan, Albert C Y; Yu, Wan Ching; Poon, Ronnie T P; Lo, Chung Mau; Fan, Sheung Tat

2012-06-01

The indocyanine green (ICG) retention test is the most popular liver function test for selecting patients for major hepatectomy. Traditionally, it is done using spectrophotometry with serial blood sampling. The newly-developed pulse spectrophotometry is a faster alternative, but its accuracy on Child-Pugh A cirrhotic patients undergoing hepatectomy for hepatocellular carcinoma has not been well documented. This study aimed to assess the accuracy of the LiMON(®), one of the pulse spectrophotometry systems, in measuring preoperative ICG retention in these patients and to devise an easy formula for conversion of the results so that they can be compared with classical literature records where ICG retention was measured by the traditional method. We measured the liver function of 70 Child-Pugh A cirrhotic patients before hepatectomy for hepatocellular carcinoma from September 2008 to January 2009. ICG retention at 15 minutes measured by traditional spectrophotometry (ICGR15) was compared with ICG retention at 15 minutes measured by the LiMON (ICGR15(L)). The median ICGR15 was 14.7% (5.6%-32%) and the median ICGR15(L) was 10.4% (1.2%-28%). The mean difference between them was -4.3606. There was a strong correlation between ICGR15 and ICGR15(L) (correlation coefficient, 0.844; 95% confidence interval, 0.762-0.899). The following formula was devised: ICGR15=1.16XICGR15(L)+2.73. The LiMON provides a fast and repeatable way to measure ICG retention at 15 minutes, but with constant underestimation of the real value. Therefore, when comparing results obtained by traditional spectrophotometry and the LiMON, adjustment of results from the latter is necessary, and this can be done with a simple mathematical calculation using the above formula.

Improved motor sequence retention by motionless listening.

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Lahav, Amir; Katz, Tal; Chess, Roxanne; Saltzman, Elliot

2013-05-01

This study examined the effect of listening to a newly learned musical piece on subsequent motor retention of the piece. Thirty-six non-musicians were trained to play an unfamiliar melody on a piano keyboard. Next, they were randomly assigned to participate in three follow-up listening sessions over 1 week. Subjects who, during their listening sessions, listened to the same initial piece showed significant improvements in motor memory and retention of the piece despite the absence of physical practice. These improvements included increased pitch accuracy, time accuracy, and dynamic intensity of key pressing. Similar improvements, though to a lesser degree, were observed in subjects who, during their listening sessions, were distracted by another task. Control subjects, who after learning the piece had listened to nonmusical sounds, showed impaired motoric retention of the piece at 1 week from the initial acquisition day. These results imply that motor sequences can be established in motor memory without direct access to motor-related information. In addition, the study revealed that the listening-induced improvements did not generalize to the learning of a new musical piece composed of the same notes as the initial piece learned, limiting the effects to musical motor sequences that are already part of the individual's motor repertoire.

Fuzzy interval Finite Element/Statistical Energy Analysis for mid-frequency analysis of built-up systems with mixed fuzzy and interval parameters

Science.gov (United States)

Yin, Hui; Yu, Dejie; Yin, Shengwen; Xia, Baizhan

2016-10-01

This paper introduces mixed fuzzy and interval parametric uncertainties into the FE components of the hybrid Finite Element/Statistical Energy Analysis (FE/SEA) model for mid-frequency analysis of built-up systems, thus an uncertain ensemble combining non-parametric with mixed fuzzy and interval parametric uncertainties comes into being. A fuzzy interval Finite Element/Statistical Energy Analysis (FIFE/SEA) framework is proposed to obtain the uncertain responses of built-up systems, which are described as intervals with fuzzy bounds, termed as fuzzy-bounded intervals (FBIs) in this paper. Based on the level-cut technique, a first-order fuzzy interval perturbation FE/SEA (FFIPFE/SEA) and a second-order fuzzy interval perturbation FE/SEA method (SFIPFE/SEA) are developed to handle the mixed parametric uncertainties efficiently. FFIPFE/SEA approximates the response functions by the first-order Taylor series, while SFIPFE/SEA improves the accuracy by considering the second-order items of Taylor series, in which all the mixed second-order items are neglected. To further improve the accuracy, a Chebyshev fuzzy interval method (CFIM) is proposed, in which the Chebyshev polynomials is used to approximate the response functions. The FBIs are eventually reconstructed by assembling the extrema solutions at all cut levels. Numerical results on two built-up systems verify the effectiveness of the proposed methods.

Reduction in the absorption and retention of strontium in rats

Energy Technology Data Exchange (ETDEWEB)

Slat, B; Kostial, K; Harrison, G E

1971-12-01

Rats were fed a stock diet supplemented with calcium phosphate and sodium alginate, both separately and simultaneously, over a period of 4-5 months. Observations were made at intervals on the growth rate and on visual and histological abnormalities in some body tissues. No toxic effects were observed. The absorption and skeletal retention of calcium for rats on the combined supplements remained almost unchanged but the absorption and retention of strontium was reduced 7-fold.

Novel word retention in bilingual and monolingual speakers

Directory of Open Access Journals (Sweden)

Pui Fong eKan

2014-09-01

Full Text Available The goal of this research was to examine word retention in bilinguals and monolinguals. Long-term word retention is an essential part of vocabulary learning. Previous studies have documented that bilinguals outperform monolinguals in terms of retrieving newly-exposed words. Yet, little is known about whether or to what extent bilinguals are different from monolinguals in word retention. Participants were 30 English-speaking monolingual adults and 30 bilingual adults who speak Spanish as a home language and learned English as a second language during childhood. In a previous study (Kan, Sadagopan, Janich, & Andrade, 2014, the participants were exposed to the target novel words in English, Spanish, and Cantonese. In this current study, word retention was measured a week after the fast mapping task. No exposures were given during the one-week interval. Results showed that bilinguals and monolinguals retain a similar number of words. However, participants produced more words in English than in either Spanish or Cantonese. Correlation analyses revealed that language knowledge plays a role in the relationships between fast mapping and word retention. Specifically, within- and across-language relationships between bilinguals’ fast mapping and word retention were found in Spanish and English, by contrast, within-language relationships between monolinguals’ fast mapping and word retention were found in English and across-language relationships between their fast mapping and word retention performance in English and Cantonese. Similarly, bilinguals differed from monolinguals in the relationships among the word retention scores in three languages. Significant correlations were found among bilinguals’ retention scores. However, no such correlations were found among monolinguals’ retention scores. The overall findings suggest that bilinguals’ language experience and language knowledge most likely contribute to how they learn and retain new words.

Novel word retention in bilingual and monolingual speakers.

Science.gov (United States)

Kan, Pui Fong; Sadagopan, Neeraja

2014-01-01

The goal of this research was to examine word retention in bilinguals and monolinguals. Long-term word retention is an essential part of vocabulary learning. Previous studies have documented that bilinguals outperform monolinguals in terms of retrieving newly-exposed words. Yet, little is known about whether or to what extent bilinguals are different from monolinguals in word retention. Participants were 30 English-speaking monolingual adults and 30 bilingual adults who speak Spanish as a home language and learned English as a second language during childhood. In a previous study (Kan et al., 2014), the participants were exposed to the target novel words in English, Spanish, and Cantonese. In this current study, word retention was measured a week after the fast mapping task. No exposures were given during the one-week interval. Results showed that bilinguals and monolinguals retain a similar number of words. However, participants produced more words in English than in either Spanish or Cantonese. Correlation analyses revealed that language knowledge plays a role in the relationships between fast mapping and word retention. Specifically, within- and across-language relationships between bilinguals' fast mapping and word retention were found in Spanish and English, by contrast, within-language relationships between monolinguals' fast mapping and word retention were found in English and across-language relationships between their fast mapping and word retention performance in English and Cantonese. Similarly, bilinguals differed from monolinguals in the relationships among the word retention scores in three languages. Significant correlations were found among bilinguals' retention scores. However, no such correlations were found among monolinguals' retention scores. The overall findings suggest that bilinguals' language experience and language knowledge most likely contribute to how they learn and retain new words.

Effects of Training and Feedback on Accuracy of Predicting Rectosigmoid Neoplastic Lesions and Selection of Surveillance Intervals by Endoscopists Performing Optical Diagnosis of Diminutive Polyps.

Science.gov (United States)

Vleugels, Jasper L A; Dijkgraaf, Marcel G W; Hazewinkel, Yark; Wanders, Linda K; Fockens, Paul; Dekker, Evelien

2018-05-01

Real-time differentiation of diminutive polyps (1-5 mm) during endoscopy could replace histopathology analysis. According to guidelines, implementation of optical diagnosis into routine practice would require it to identify rectosigmoid neoplastic lesions with a negative predictive value (NPV) of more than 90%, using histologic findings as a reference, and agreement with histology-based surveillance intervals for more than 90% of cases. We performed a prospective study with 39 endoscopists accredited to perform colonoscopies on participants with positive results from fecal immunochemical tests in the Bowel Cancer Screening Program at 13 centers in the Netherlands. Endoscopists were trained in optical diagnosis using a validated module (Workgroup serrAted polypS and Polyposis). After meeting predefined performance thresholds in the training program, the endoscopists started a 1-year program (continuation phase) in which they performed narrow band imaging analyses during colonoscopies of participants in the screening program and predicted histological findings with confidence levels. The endoscopists were randomly assigned to groups that received feedback or no feedback on the accuracy of their predictions. Primary outcome measures were endoscopists' abilities to identify rectosigmoid neoplastic lesions (using histology as a reference) with NPVs of 90% or more, and selecting surveillance intervals that agreed with those determined by histology for at least 90% of cases. Of 39 endoscopists initially trained, 27 (69%) completed the training program. During the continuation phase, these 27 endoscopists performed 3144 colonoscopies in which 4504 diminutive polyps were removed. The endoscopists identified neoplastic lesions with a pooled NPV of 90.8% (95% confidence interval 88.6-92.6); their proposed surveillance intervals agreed with those determined by histologic analysis for 95.4% of cases (95% confidence interval 94.0-96.6). Findings did not differ between the group

[Systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography].

Science.gov (United States)

Fu, Qing; Wang, Jun; Liang, Tu; Xu, Xiaoyong; Jin, Yu

2013-11-01

A systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography (HILIC) was performed. The influences of mobile phase, stationary phase and buffer salt on the retention of carbohydrates were investigated. According to the results, the retention time of carbohydrates decreased as the proportion of acetonitrile in mobile phase decreased. Increased time of carbohydrates was observed as the concentration of buffer salt in mobile phase increased. The retention behavior of carbohydrates was also affected by organic solvent and HILIC stationary phase. Furthermore, an appropriate retention equation was used in HILIC mode. The retention equation lnk = a + blnC(B) + cC(B) could quantitatively describe the retention factors of carbohydrates of plant origin with good accuracy: the relative error of the predicted time to actual time was less than 0.3%. The evaluation results could provide guidance for carbohydrates to optimize the experimental conditions in HILIC method development especially for carbohydrate separation

Very long-term retention of basic science knowledge in doctors after graduation.

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Custers, Eugène J F M; Ten Cate, Olle T J

2011-04-01

Despite frequent complaints that biomedical knowledge is quickly forgotten after it has been learned, few investigations of actual long-term retention of basic science knowledge have been conducted in the medical domain. Our aim was to illuminate the long-term retention of basic science knowledge, particularly of unrehearsed knowledge. Using a cross-sectional study design, medical students and doctors in the Netherlands were tested for retention of basic science knowledge. Relationships between retention interval and proportion of correct answers on a knowledge test were investigated. The popular notion that most of basic science knowledge is forgotten shortly after graduation is not supported by our findings. With respect to the full test scores, which reflect a composite of unrehearsed and rehearsed knowledge, performance decreased from approximately 40% correct answers for students still in medical school, to 25-30% correct answers for doctors after many years of practice. When rehearsal during the retention interval is controlled for, it appears that little knowledge is lost for 1.5-2 years after it was last used; from then on, retention is best described by a negatively accelerated (logarithmic) forgetting curve. After ≥ 25 years, retention levels were in the range of 15-20%. Conclusions about the forgetting of unrehearsed knowledge in this study are in line with findings reported in other domains: it proceeds in accordance with the Ebbinghaus curve for meaningful material, except that in our findings the 'downward' part appears to start later than in most other studies. The limitations of the study are discussed and possible ramifications for medical education are proposed. © Blackwell Publishing Ltd 2011.

Retention among North American HIV-infected persons in clinical care, 2000-2008.

Science.gov (United States)

Rebeiro, Peter; Althoff, Keri N; Buchacz, Kate; Gill, John; Horberg, Michael; Krentz, Hartmut; Moore, Richard; Sterling, Timothy R; Brooks, John T; Gebo, Kelly A; Hogg, Robert; Klein, Marina; Martin, Jeffrey; Mugavero, Michael; Rourke, Sean; Silverberg, Michael J; Thorne, Jennifer; Gange, Stephen J

2013-03-01

Retention in care is key to improving HIV outcomes. The goal of this study was to describe 'churn' in patterns of entry, exit, and retention in HIV care in the United States and Canada. Adults contributing ≥1 CD4 count or HIV-1 RNA (HIV-lab) from 2000 to 2008 in North American AIDS Cohort Collaboration on Research and Design clinical cohorts were included. Incomplete retention was defined as lack of 2 HIV-laboratories (≥90 days apart) within 12 months, summarized by calendar year. Beta-binomial regression models were used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) of factors associated with incomplete retention. Among 61,438 participants, 15,360 (25%) with incomplete retention significantly differed in univariate analyses (P churn. In addition to the programmatic and policy implications, the findings of this study identify patient groups who may benefit from focused retention efforts.

Sequence-Specific Model for Peptide Retention Time Prediction in Strong Cation Exchange Chromatography.

Science.gov (United States)

Gussakovsky, Daniel; Neustaeter, Haley; Spicer, Victor; Krokhin, Oleg V

2017-11-07

The development of a peptide retention prediction model for strong cation exchange (SCX) separation on a Polysulfoethyl A column is reported. Off-line 2D LC-MS/MS analysis (SCX-RPLC) of S. cerevisiae whole cell lysate was used to generate a retention dataset of ∼30 000 peptides, sufficient for identifying the major sequence-specific features of peptide retention mechanisms in SCX. In contrast to RPLC/hydrophilic interaction liquid chromatography (HILIC) separation modes, where retention is driven by hydrophobic/hydrophilic contributions of all individual residues, SCX interactions depend mainly on peptide charge (number of basic residues at acidic pH) and size. An additive model (incorporating the contributions of all 20 residues into the peptide retention) combined with a peptide length correction produces a 0.976 R 2 value prediction accuracy, significantly higher than the additive models for either HILIC or RPLC. Position-dependent effects on peptide retention for different residues were driven by the spatial orientation of tryptic peptides upon interaction with the negatively charged surface functional groups. The positively charged N-termini serve as a primary point of interaction. For example, basic residues (Arg, His, Lys) increase peptide retention when located closer to the N-terminus. We also found that hydrophobic interactions, which could lead to a mixed-mode separation mechanism, are largely suppressed at 20-30% of acetonitrile in the eluent. The accuracy of the final Sequence-Specific Retention Calculator (SSRCalc) SCX model (∼0.99 R 2 value) exceeds all previously reported predictors for peptide LC separations. This also provides a solid platform for method development in 2D LC-MS protocols in proteomics and peptide retention prediction filtering of false positive identifications.

Retention of Knowledge following training of students in Basic Trauma Life Support.

Science.gov (United States)

Lim, K G; Lum, S K; Burud, I A S

2016-12-01

In the course of their undergraduate training at the International Medical University, students receive a Basic Trauma Life Support course. We wanted to test the long-term retention of knowledge (after 16 months) of third year medical students who had received training in Basic Trauma Life Support Method: To assess the retention of knowledge one cohort of students who received the training course were tested again 16 months later using the same 30 question One Best Answer quiz. Seventy-three students who underwent the course sat for the Retention test. The number of students who passed the Retention test was not significantly different from the test taken immediately after the course. The mean scores, 62.5% and 59.5% respectively, were however significantly different. Our study involves a relatively long interval between the course and retention of knowledge test shows encouraging results.

Retention of autobiographical memories: an Internet-based diary study.

Science.gov (United States)

Kristo, Gert; Janssen, Steve M J; Murre, Jaap M J

2009-11-01

In this online study we examined the retention of recent personal events using an Internet-based diary technique. Each participant (N=878) recorded on a website one recent personal event and was contacted after a retention interval that ranged between 2 and 46 days. We investigated how well the participants could recall the content, time, and details of their recorded event. We found a classic retention function. Details of the events were forgotten more rapidly than the content and the time of the events. There were no differences between the forgetting rates of the "who", "what" and "where" elements of the content component. Reminiscing, social sharing, pleasantness, and frequency of occurrence aided recall, but surprisingly importance and emotionality did not. They were, however, strongly associated with reminiscing and social sharing.

Predicting fecal coliform using the interval-to-interval approach and SWAT in the Miyun watershed, China.

Science.gov (United States)

Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu; Qiu, Jiali; Li, Yangyang

2017-06-01

Pathogens in manure can cause waterborne-disease outbreaks, serious illness, and even death in humans. Therefore, information about the transformation and transport of bacteria is crucial for determining their source. In this study, the Soil and Water Assessment Tool (SWAT) was applied to simulate fecal coliform bacteria load in the Miyun Reservoir watershed, China. The data for the fecal coliform were obtained at three sampling sites, Chenying (CY), Gubeikou (GBK), and Xiahui (XH). The calibration processes of the fecal coliform were conducted using the CY and GBK sites, and validation was conducted at the XH site. An interval-to-interval approach was designed and incorporated into the processes of fecal coliform calibration and validation. The 95% confidence interval of the predicted values and the 95% confidence interval of measured values were considered during calibration and validation in the interval-to-interval approach. Compared with the traditional point-to-point comparison, this method can improve simulation accuracy. The results indicated that the simulation of fecal coliform using the interval-to-interval approach was reasonable for the watershed. This method could provide a new research direction for future model calibration and validation studies.

Retention Among North American HIV–infected Persons in Clinical Care, 2000–2008

Science.gov (United States)

Rebeiro, Peter; Althoff, Keri N.; Buchacz, Kate; Gill, M. John; Horberg, Michael; Krentz, Hartmut; Moore, Richard; Sterling, Timothy R.; Brooks, John T.; Gebo, Kelly A.; Hogg, Robert; Klein, Marina; Martin, Jeffrey; Mugavero, Michael; Rourke, Sean; Silverberg, Michael J.; Thorne, Jennifer; Gange, Stephen J.

2013-01-01

Background Retention in care is key to improving HIV outcomes. Our goal was to describe “churn” in patterns of entry, exit, and retention in HIV care in the US and Canada. Methods Adults contributing ≥1 CD4 count or HIV-1 RNA (HIV-lab) from 2000–2008 in North American Cohort Collaboration on Research and Design (NA-ACCORD) clinical cohorts were included. Incomplete retention was defined as lack of 2 HIV-labs (≥90 days apart) within 12 months, summarized by calendar year. We used beta-binomial regression models to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) of factors associated with incomplete retention. Results Among 61,438 participants, 15,360 (25%) with incomplete retention significantly differed in univariate analyses (pchurn. In addition to the programmatic and policy implications, our findings identify patient groups who may benefit from focused retention efforts. PMID:23242158

Assessment of patency capsule retention using MR diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Klang, Eyal; Rozendorn, Noa; Amitai, Michal Marianne [Sheba Medical Center, Department of Diagnostic Imaging, Ramat Gan (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Kopylov, Uri; Ben-Horin, Shomron; Lahat, Adi; Yablecovitch, Doron; Eliakim, Rami [Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Sheba Medical Center, Department of Gastroenterology, Ramat Gan (Israel)

2017-12-15

Evaluate the ability of MR diffusion-weighted imaging (DWI) to predict patency capsule retention in Crohn's disease (CD). Clinical and imaging data were prospectively reviewed for 80 CD patients following patency capsule administration and MR-DWI under institutional review board (IRB) approval with informed consent. Two radiologists separately assessed the presence/absence of restricted diffusion in the distal ileum. Apparent diffusion coefficients (ADC) from three regions of interest on the ileal wall were averaged. The association between restricted diffusion and retention, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Ability of ADC to predict retention was assessed with receiver operating characteristic (ROC) curve analysis. Restricted diffusion in the distal ileum was associated with capsule retention (p = 0.001, p < 0.0001). Sensitivity, specificity, PPV and NPV of restricted diffusion for capsule retention were 100.0%, 46.2%, 30.0%, 100% and 100.0%, 56.9%, 34.9%, 100%, respectively, for two radiologists. Accuracy of ADC to predict retention was high (area under the curve = 0.851, p < 0.0001). An ADC of 1.47 mm{sup 2}/s showed 90.0% sensitivity and 50.0% specificity for retention. Sensitivity and NPV of restricted diffusion for patency capsule retention were 100%, suggesting that DWI may predict gastrointestinal tract capability to pass video camera endoscopy. (orig.)

Assessment of patency capsule retention using MR diffusion-weighted imaging

International Nuclear Information System (INIS)

Klang, Eyal; Rozendorn, Noa; Amitai, Michal Marianne; Kopylov, Uri; Ben-Horin, Shomron; Lahat, Adi; Yablecovitch, Doron; Eliakim, Rami

2017-01-01

Evaluate the ability of MR diffusion-weighted imaging (DWI) to predict patency capsule retention in Crohn's disease (CD). Clinical and imaging data were prospectively reviewed for 80 CD patients following patency capsule administration and MR-DWI under institutional review board (IRB) approval with informed consent. Two radiologists separately assessed the presence/absence of restricted diffusion in the distal ileum. Apparent diffusion coefficients (ADC) from three regions of interest on the ileal wall were averaged. The association between restricted diffusion and retention, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Ability of ADC to predict retention was assessed with receiver operating characteristic (ROC) curve analysis. Restricted diffusion in the distal ileum was associated with capsule retention (p = 0.001, p < 0.0001). Sensitivity, specificity, PPV and NPV of restricted diffusion for capsule retention were 100.0%, 46.2%, 30.0%, 100% and 100.0%, 56.9%, 34.9%, 100%, respectively, for two radiologists. Accuracy of ADC to predict retention was high (area under the curve = 0.851, p < 0.0001). An ADC of 1.47 mm 2 /s showed 90.0% sensitivity and 50.0% specificity for retention. Sensitivity and NPV of restricted diffusion for patency capsule retention were 100%, suggesting that DWI may predict gastrointestinal tract capability to pass video camera endoscopy. (orig.)

Effects of Different Types of True-False Questions on Memory Awareness and Long-Term Retention

Science.gov (United States)

Schaap, Lydia; Verkoeijen, Peter; Schmidt, Henk

2014-01-01

This study investigated the effects of two different true-false questions on memory awareness and long-term retention of knowledge. Participants took four subsequent knowledge tests on curriculum learning material that they studied at different retention intervals prior to the start of this study (i.e. prior to the first test). At the first and…

a New Approach for Accuracy Improvement of Pulsed LIDAR Remote Sensing Data

Science.gov (United States)

Zhou, G.; Huang, W.; Zhou, X.; He, C.; Li, X.; Huang, Y.; Zhang, L.

2018-05-01

In remote sensing applications, the accuracy of time interval measurement is one of the most important parameters that affect the quality of pulsed lidar data. The traditional time interval measurement technique has the disadvantages of low measurement accuracy, complicated circuit structure and large error. A high-precision time interval data cannot be obtained in these traditional methods. In order to obtain higher quality of remote sensing cloud images based on the time interval measurement, a higher accuracy time interval measurement method is proposed. The method is based on charging the capacitance and sampling the change of capacitor voltage at the same time. Firstly, the approximate model of the capacitance voltage curve in the time of flight of pulse is fitted based on the sampled data. Then, the whole charging time is obtained with the fitting function. In this method, only a high-speed A/D sampler and capacitor are required in a single receiving channel, and the collected data is processed directly in the main control unit. The experimental results show that the proposed method can get error less than 3 ps. Compared with other methods, the proposed method improves the time interval accuracy by at least 20 %.

Electrophysiological correlates of the retention of tones differing in timbre in auditory short-term memory.

Science.gov (United States)

Nolden, Sophie; Bermudez, Patrick; Alunni-Menichini, Kristelle; Lefebvre, Christine; Grimault, Stephan; Jolicoeur, Pierre

2013-11-01

We examined the electrophysiological correlates of retention in auditory short-term memory (ASTM) for sequences of one, two, or three tones differing in timbre but having the same pitch. We focused on event-related potentials (ERPs) during the retention interval and revealed a sustained fronto-central ERP component (most likely a sustained anterior negativity; SAN) that became more negative as memory load increased. Our results are consistent with recent ERP studies on the retention of pitch and suggest that the SAN reflects brain activity mediating the low-level retention of basic acoustic features in ASTM. The present work shows that the retention of timbre shares common features with the retention of pitch, hence supporting the notion that the retention of basic sensory features is an active process that recruits modality-specific brain areas. © 2013 Elsevier Ltd. All rights reserved.

Intact interval timing in circadian CLOCK mutants.

Science.gov (United States)

Cordes, Sara; Gallistel, C R

2008-08-28

While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval-timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/- and -/- mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing.

Diagnostic Accuracy 99mTc-DISIDA Scintigraphy in Biliary Atresia

International Nuclear Information System (INIS)

Hyun, In Young; Lee, Dong Soo; Lee, Kyung Han; Kim, Jong Ho; Chung, June Key; Suh, Jung Key; Lee, Myung Chul; Koh, Chang Soon

1994-01-01

We evaluated the diagnostic accuracy of 99m Tc-DISIDA scintigraphy as a mean of differentiating biliary atresia from neonatal hepatitis. 99m Tc-DISIDA scintigraphy was visually interpreted by assessing the presence or absence of radioactivity in the intestine or gall bladder. In patients without intestinal radioactivity, we measured the hepatic retention index and the hepatic uptake index. The hepatic retention index was expressed as the amount of change of liver activity from 5 minutes to 30 minutes postinjection. The hepatic uptake index was graded visually with 5 minute images using the following scoring scheme :grade 0 (normal hepatic uptake), grade 1 (decreased hepatic up take), grade 2 (hepatic uptake equal to cardiac uptake), and grade 3 (hepatic uptake less than cardiac uptake). Age, total bilirubin, and hepatic uptake index were compared between the biliary atresia and the neonatal hepatitis group, between neonatal hepatitis patients with and without intestinal radioactivity, and between the biliary atresia and neonatal hepatitis patients with absent intestinal radioactivity. The results were as follows : l) None of the 30 biliary atresia patients showed intestinal radioactivity, while 31/40 neonatal hepatitis patients showed intestinal radioactivity. The sensitivity, specificity, and accuracy of the presence of intestinal radioactivity or the diagnosis of biliary atresia was 100%, 78%, and 87%, respectively. 2) In patients with absent intestinal radioactivity the mean hepatic retention index was 1.5 ± 0.6 in the 16 biliary atresia patient,s, and 1.1 ± 0.2 in the 7 neonatal hepatitis patients(p 99m Tc-DISIDA scintigraphy is accurate in the differential diagnosis of biliary atresia and neonatal hepatitis. In patients without intestinal radioactivity, the hepatic retention index and hepatic uptake index, along with the patients age and total bilirubin level may supplement diagnosis and improve diagnostic accuracy.

Sensitivity and specificity of normality tests and consequences on reference interval accuracy at small sample size: a computer-simulation study.

Science.gov (United States)

Le Boedec, Kevin

2016-12-01

According to international guidelines, parametric methods must be chosen for RI construction when the sample size is small and the distribution is Gaussian. However, normality tests may not be accurate at small sample size. The purpose of the study was to evaluate normality test performance to properly identify samples extracted from a Gaussian population at small sample sizes, and assess the consequences on RI accuracy of applying parametric methods to samples that falsely identified the parent population as Gaussian. Samples of n = 60 and n = 30 values were randomly selected 100 times from simulated Gaussian, lognormal, and asymmetric populations of 10,000 values. The sensitivity and specificity of 4 normality tests were compared. Reference intervals were calculated using 6 different statistical methods from samples that falsely identified the parent population as Gaussian, and their accuracy was compared. Shapiro-Wilk and D'Agostino-Pearson tests were the best performing normality tests. However, their specificity was poor at sample size n = 30 (specificity for P Box-Cox transformation) on all samples regardless of their distribution or adjusting, the significance level of normality tests depending on sample size would limit the risk of constructing inaccurate RI. © 2016 American Society for Veterinary Clinical Pathology.

The effects of intervening interference on working memory for sound location as a function of inter-comparison interval.

Science.gov (United States)

Ries, Dennis T; Hamilton, Traci R; Grossmann, Aurora J

2010-09-01

This study examined the effects of inter-comparison interval duration and intervening interference on auditory working memory (AWM) for auditory location. Interaural phase differences were used to produce localization cues for tonal stimuli and the difference limen for interaural phase difference (DL-IPD) specified as the equivalent angle of incidence between two sound sources was measured in five different conditions. These conditions consisted of three different inter-comparison intervals [300 ms (short), 5000 ms (medium), and 15,000 ms (long)], the medium and long of which were presented both in the presence and absence of intervening tones. The presence of intervening stimuli within the medium and long inter-comparison intervals produced a significant increase in the DL-IPD compared to the medium and long inter-comparison intervals condition without intervening tones. The result obtained in the condition with a short inter-comparison interval was roughly equivalent to that obtained for the medium inter-comparison interval without intervening tones. These results suggest that the ability to retain information about the location of a sound within AWM decays slowly; however, the presence of intervening sounds readily disrupts the retention process. Overall, the results suggest that the temporal decay of information within AWM regarding the location of a sound from a listener's environment is so gradual that it can be maintained in trace memory for tens of seconds in the absence of intervening acoustic signals. Conversely, the presence of intervening sounds within the retention interval may facilitate the use of context memory, even for shorter retention intervals, resulting in a less detailed, but relevant representation of the location that is resistant to further degradation. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Blood Pressure Directed Booster Trainings Improve Intensive Care Unit Provider Retention of Excellent Cardiopulmonary Resuscitation Skills.

Science.gov (United States)

Wolfe, Heather; Maltese, Matthew R; Niles, Dana E; Fischman, Elizabeth; Legkobitova, Veronika; Leffelman, Jessica; Berg, Robert A; Nadkarni, Vinay M; Sutton, Robert M

2015-11-01

Brief, intermittent cardiopulmonary resuscitation (CPR) training sessions, "Booster Trainings," improve CPR skill acquisition and short-term retention. The objective of this study was to incorporate arterial blood pressure (ABP) tracings into Booster Trainings to improve CPR skill retention. We hypothesized that ABP-directed CPR "Booster Trainings" would improve intensive care unit (ICU) provider 3-month retention of excellent CPR skills without need for interval retraining. A CPR manikin creating a realistic relationship between chest compression depth and ABP was used for training/testing. Thirty-six ICU providers were randomized to brief, bedside ABP-directed CPR manikin skill retrainings: (1) Booster Plus (ABP visible during training and testing) versus (2) Booster Alone (ABP visible only during training, not testing) versus (3) control (testing, no intervention). Subjects completed skill tests pretraining (baseline), immediately after training (acquisition), and then retention was assessed at 12 hours, 3 and 6 months. The primary outcome was retention of excellent CPR skills at 3 months. Excellent CPR was defined as systolic blood pressure of 100 mm Hg or higher and compression rate 100 to 120 per minute. Overall, 14 of 24 (58%) participants acquired excellent CPR skills after their initial training (Booster Plus 75% vs 50% Booster Alone, P = 0.21). Adjusted for age, ABP-trained providers were 5.2× more likely to perform excellent CPR after the initial training (95% confidence interval [95% CI], 1.3-21.2; P = 0.02), and to retain these skills at 12 hours (adjusted odds ratio, 4.4; 95% CI, 1.3-14.9; P = 0.018) and 3 months (adjusted odds ratio, 4.1; 95% CI, 1.2-13.9; P = 0.023) when compared to baseline performance. The ABP-directed CPR booster trainings improved ICU provider 3-month retention of excellent CPR skills without the need for interval retraining.

Magnetic Resonance Fingerprinting with short relaxation intervals.

Science.gov (United States)

Amthor, Thomas; Doneva, Mariya; Koken, Peter; Sommer, Karsten; Meineke, Jakob; Börnert, Peter

2017-09-01

The aim of this study was to investigate a technique for improving the performance of Magnetic Resonance Fingerprinting (MRF) in repetitive sampling schemes, in particular for 3D MRF acquisition, by shortening relaxation intervals between MRF pulse train repetitions. A calculation method for MRF dictionaries adapted to short relaxation intervals and non-relaxed initial spin states is presented, based on the concept of stationary fingerprints. The method is applicable to many different k-space sampling schemes in 2D and 3D. For accuracy analysis, T 1 and T 2 values of a phantom are determined by single-slice Cartesian MRF for different relaxation intervals and are compared with quantitative reference measurements. The relevance of slice profile effects is also investigated in this case. To further illustrate the capabilities of the method, an application to in-vivo spiral 3D MRF measurements is demonstrated. The proposed computation method enables accurate parameter estimation even for the shortest relaxation intervals, as investigated for different sampling patterns in 2D and 3D. In 2D Cartesian measurements, we achieved a scan acceleration of more than a factor of two, while maintaining acceptable accuracy: The largest T 1 values of a sample set deviated from their reference values by 0.3% (longest relaxation interval) and 2.4% (shortest relaxation interval). The largest T 2 values showed systematic deviations of up to 10% for all relaxation intervals, which is discussed. The influence of slice profile effects for multislice acquisition is shown to become increasingly relevant for short relaxation intervals. In 3D spiral measurements, a scan time reduction of 36% was achieved, maintaining the quality of in-vivo T1 and T2 maps. Reducing the relaxation interval between MRF sequence repetitions using stationary fingerprint dictionaries is a feasible method to improve the scan efficiency of MRF sequences. The method enables fast implementations of 3D spatially

Retention and Deformation of Cobalt-Chromium and High-Impact Polyamide Clasps

Directory of Open Access Journals (Sweden)

Övül Kümbüloğlu

2018-04-01

Full Text Available Objective: The use of metal clasps especially in anterior region may cause aesthetic problems. Polyamide resin has been suggested as an alternative aesthetic denture clasp material. This study compared the retentive force and deformation of cobalt-chromium and polyamide clasps after 36 months of simulated clinical use. Materials and Methods: The retentive force for clasp removal was measured in distilled water using a custom-made apparatus with intervals corresponding to 0, 6, 12, 18, 24, 30 and 36 months of simulated clinical use. The distance (mm between the retentive and reciprocal clasp tips was measured using a microscope before and after the insertion-removal procedures. Results: Significant difference was observed in distance between clasp tips for metal clasps between baseline and 36 months for molars and premolars (p0.05. Conclusion: Polyamide clasps could be alternative to metal clasps particularly on premolars with reliable retention and deformation.

Retention of anatomy knowledge by student radiographers

International Nuclear Information System (INIS)

Hall, A. Susanne; Durward, Brian R.

2009-01-01

Introduction: Anatomy has long been regarded as an integral part of the core curriculum. However, anecdotal evidence suggests that long-term retention of anatomy knowledge may be deficient. This study aims to evidence whether student radiographers demonstrate the same level of knowledge of anatomy after a period of time has elapsed and to correlate to approaches to learning and studying. Methodology: A repeated measures design was utilised to measure retention of anatomy knowledge for both MCQs and short-response answers to a Practical Radiographic Anatomy Examination; alpha value p < 0.05. Fifty-one students from levels 2 and 3 were retested after a time lapse of 10 and 22 months respectively. The students were not aware that their knowledge was being retested. Approaches to learning and studying were measured using the ASSIST inventory. Results: Statistical analysis found no difference in performance on MCQ assessment, in either the combined sample or levels 2 and 3 separately, from baseline to retention occasions; average retention rate being 99%. However, a statistical difference in performance on PRAE assessment was found, with level 2 experiencing a larger reduction in scores; retention rate of 67% compared to level 3 at 77%. The students perceived themselves to be principally strategic in their approach to learning and studying but no strong relationships were found when correlated to test scores. Conclusion: The student radiographers in this study demonstrated varied anatomy retention rates dependent on assessment method employed and time interval that had elapsed. It is recommended that diverse teaching and assessment strategies are adopted to encourage a deeper approach to learning and studying.

Interval timing in genetically modified mice: a simple paradigm

OpenAIRE

Balci, F.; Papachristos, E. B.; Gallistel, C. R.; Brunner, D.; Gibson, J.; Shumyatsky, G. P.

2007-01-01

We describe a behavioral screen for the quantitative study of interval timing and interval memory in mice. Mice learn to switch from a short-latency feeding station to a long-latency station when the short latency has passed without a feeding. The psychometric function is the cumulative distribution of switch latencies. Its median measures timing accuracy and its interquartile interval measures timing precision. Next, using this behavioral paradigm, we have examined mice with a gene knockout ...

Application of FFTBM with signal mirroring to improve accuracy assessment of MELCOR code

International Nuclear Information System (INIS)

Saghafi, Mahdi; Ghofrani, Mohammad Bagher; D’Auria, Francesco

2016-01-01

Highlights: • FFTBM-SM is an improved Fast Fourier Transform Base Method by signal mirroring. • FFTBM-SM has been applied to accuracy assessment of MELCOR code predictions. • The case studied was Station Black-Out accident in PSB-VVER integral test facility. • FFTBM-SM eliminates fluctuations of accuracy indices when signals sharply change. • Accuracy assessment is performed in a more realistic and consistent way by FFTBM-SM. - Abstract: This paper deals with the application of Fast Fourier Transform Base Method (FFTBM) with signal mirroring (FFTBM-SM) to assess accuracy of MELCOR code. This provides deeper insights into how the accuracy of MELCOR code in predictions of thermal-hydraulic parameters varies during transients. The case studied was modeling of Station Black-Out (SBO) accident in PSB-VVER integral test facility by MELCOR code. The accuracy of this thermal-hydraulic modeling was previously quantified using original FFTBM in a few number of time-intervals, based on phenomenological windows of SBO accident. Accuracy indices calculated by original FFTBM in a series of time-intervals unreasonably fluctuate when the investigated signals sharply increase or decrease. In the current study, accuracy of MELCOR code is quantified using FFTBM-SM in a series of increasing time-intervals, and the results are compared to those with original FFTBM. Also, differences between the accuracy indices of original FFTBM and FFTBM-SM are investigated and correction factors calculated to eliminate unphysical effects in original FFTBM. The main findings are: (1) replacing limited number of phenomena-based time-intervals by a series of increasing time-intervals provides deeper insights about accuracy variation of the MELCOR calculations, and (2) application of FFTBM-SM for accuracy evaluation of the MELCOR predictions, provides more reliable results than original FFTBM by eliminating the fluctuations of accuracy indices when experimental signals sharply increase or

Application of FFTBM with signal mirroring to improve accuracy assessment of MELCOR code

Energy Technology Data Exchange (ETDEWEB)

Saghafi, Mahdi [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); Ghofrani, Mohammad Bagher, E-mail: ghofrani@sharif.edu [Department of Energy Engineering, Sharif University of Technology, Azadi Avenue, Tehran (Iran, Islamic Republic of); D’Auria, Francesco [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, San Piero a Grado, Pisa (Italy)

2016-11-15

Highlights: • FFTBM-SM is an improved Fast Fourier Transform Base Method by signal mirroring. • FFTBM-SM has been applied to accuracy assessment of MELCOR code predictions. • The case studied was Station Black-Out accident in PSB-VVER integral test facility. • FFTBM-SM eliminates fluctuations of accuracy indices when signals sharply change. • Accuracy assessment is performed in a more realistic and consistent way by FFTBM-SM. - Abstract: This paper deals with the application of Fast Fourier Transform Base Method (FFTBM) with signal mirroring (FFTBM-SM) to assess accuracy of MELCOR code. This provides deeper insights into how the accuracy of MELCOR code in predictions of thermal-hydraulic parameters varies during transients. The case studied was modeling of Station Black-Out (SBO) accident in PSB-VVER integral test facility by MELCOR code. The accuracy of this thermal-hydraulic modeling was previously quantified using original FFTBM in a few number of time-intervals, based on phenomenological windows of SBO accident. Accuracy indices calculated by original FFTBM in a series of time-intervals unreasonably fluctuate when the investigated signals sharply increase or decrease. In the current study, accuracy of MELCOR code is quantified using FFTBM-SM in a series of increasing time-intervals, and the results are compared to those with original FFTBM. Also, differences between the accuracy indices of original FFTBM and FFTBM-SM are investigated and correction factors calculated to eliminate unphysical effects in original FFTBM. The main findings are: (1) replacing limited number of phenomena-based time-intervals by a series of increasing time-intervals provides deeper insights about accuracy variation of the MELCOR calculations, and (2) application of FFTBM-SM for accuracy evaluation of the MELCOR predictions, provides more reliable results than original FFTBM by eliminating the fluctuations of accuracy indices when experimental signals sharply increase or

Liver scanning in short interval autopsy material of cancer patients

International Nuclear Information System (INIS)

Appelqvist, P.; Salmo, M.; Kostiainen, S.

1980-01-01

The accuracy of liverscanning alkaline phosphatase and 5'-nucleotidase in the detection of the hepatic metastases was studied in short interval autopsy material of 243 cancer patients. The highest percentage of correct diagnosis was by 5'-nucleotidase, alkaline phosphatase was the second, and scanning third. The overall accuracy of liver scan was 68 per cent. It was the better the shorter the time interval between scanning and autopsy. The higher percentage of incorrect diagnoses of the scan was related to a larger number of false positives, the causes of which were to be verified only in half of the cases. (orig.) [de

Application of the entropic coefficient for interval number optimization during interval assessment

Directory of Open Access Journals (Sweden)

Tynynyka A. N.

2017-06-01

Full Text Available In solving many statistical problems, the most precise choice of the distribution law of a random variable is required, the sample of which the authors observe. This choice requires the construction of an interval series. Therefore, the problem arises of assigning an optimal number of intervals, and this study proposes a number of formulas for solving it. Which of these formulas solves the problem more accurately? In [9], this question is investigated using the Pearson criterion. This article describes the procedure and on its basis gives formulas available in literature and proposed new formulas using the entropy coefficient. A comparison is made with the previously published results of applying Pearson's concord criterion for these purposes. Differences in the estimates of the accuracy of the formulas are found. The proposed new formulas for calculating the number of intervals showed the best results. Calculations have been made to compare the work of the same formulas for the distribution of sample data according to the normal law and the Rayleigh law.

A Neural Network-Based Interval Pattern Matcher

Directory of Open Access Journals (Sweden)

Jing Lu

2015-07-01

Full Text Available One of the most important roles in the machine learning area is to classify, and neural networks are very important classifiers. However, traditional neural networks cannot identify intervals, let alone classify them. To improve their identification ability, we propose a neural network-based interval matcher in our paper. After summarizing the theoretical construction of the model, we take a simple and a practical weather forecasting experiment, which show that the recognizer accuracy reaches 100% and that is promising.

Lactation yield: Interval level comparison of milk records for genetic ...

African Journals Online (AJOL)

Milk recording intervals was studied by analysing 1220 lactation records of Friesian x Arsi crossbred cows kept in south eastern highlands of Ethiopia. Milk Recording Intervals (MRI) comparison was made at 15, 30 and 45 day's length. Accuracy was measured in terms of percentage difference between actual and estimated ...

Increasing Free Throw Accuracy through Behavior Modeling and Goal Setting.

Science.gov (United States)

Erffmeyer, Elizabeth S.

A two-year behavior-modeling training program focusing on attention processes, retention processes, motor reproduction, and motivation processes was implemented to increase the accuracy of free throw shooting for a varsity intercollegiate women's basketball team. The training included specific learning keys, progressive relaxation, mental…

Predicting watershed sediment yields after wildland fire with the InVEST sediment retention model at large geographic extent in the western USA: accuracy and uncertainties

Science.gov (United States)

Sankey, J. B.; Kreitler, J.; McVay, J.; Hawbaker, T. J.; Vaillant, N.; Lowe, S. E.

2014-12-01

Wildland fire is a primary threat to watersheds that can impact water supply through increased sedimentation, water quality decline, and change the timing and amount of runoff leading to increased risk from flood and sediment natural hazards. It is of great societal importance in the western USA and throughout the world to improve understanding of how changing fire frequency, extent, and location, in conjunction with fuel treatments will affect watersheds and the ecosystem services they supply to communities. In this work we assess the utility of the InVEST Sediment Retention Model to accurately characterize vulnerability of burned watersheds to erosion and sedimentation. The InVEST tools are GIS-based implementations of common process models, engineered for high-end computing to allow the faster simulation of larger landscapes and incorporation into decision-making. The InVEST Sediment Retention Model is based on common soil erosion models (e.g., RUSLE -Revised Universal Soil Loss Equation) and determines which areas of the landscape contribute the greatest sediment loads to a hydrological network and conversely evaluate the ecosystem service of sediment retention on a watershed basis. We evaluate the accuracy and uncertainties for InVEST predictions of increased sedimentation after fire, using measured post-fire sedimentation rates available for many watersheds in different rainfall regimes throughout the western USA from an existing, large USGS database of post-fire sediment yield [synthesized in Moody J, Martin D (2009) Synthesis of sediment yields after wildland fire in different rainfall regimes in the western United States. International Journal of Wildland Fire 18: 96-115]. The ultimate goal of this work is to calibrate and implement the model to accurately predict variability in post-fire sediment yield as a function of future landscape heterogeneity predicted by wildfire simulations, and future landscape fuel treatment scenarios, within watersheds.

Potential of accuracy profile for method validation in inductively coupled plasma spectrochemistry

International Nuclear Information System (INIS)

Mermet, J.M.; Granier, G.

2012-01-01

Method validation is usually performed over a range of concentrations for which analytical criteria must be verified. One important criterion in quantitative analysis is accuracy, i.e. the contribution of both trueness and precision. The study of accuracy over this range is called an accuracy profile and provides experimental tolerance intervals. Comparison with acceptability limits fixed by the end user defines a validity domain. This work describes the computation involved in the building of the tolerance intervals, particularly for the intermediate precision with within-laboratory experiments and for the reproducibility with interlaboratory studies. Computation is based on ISO 5725‐4 and on previously published work. Moreover, the bias uncertainty is also computed to verify the bias contribution to accuracy. The various types of accuracy profile behavior are exemplified with results obtained by using ICP-MS and ICP-AES. This procedure allows the analyst to define unambiguously a validity domain for a given accuracy. However, because the experiments are time-consuming, the accuracy profile method is mainly dedicated to method validation. - Highlights: ► An analytical method is defined by its accuracy, i.e. both trueness and precision. ► The accuracy as a function of an analyte concentration is an accuracy profile. ► Profile basic concepts are explained for trueness and intermediate precision. ► Profile-based tolerance intervals have to be compared with acceptability limits. ► Typical accuracy profiles are given for both ICP-AES and ICP-MS techniques.

Interval methods: An introduction

DEFF Research Database (Denmark)

Achenie, L.E.K.; Kreinovich, V.; Madsen, Kaj

2006-01-01

This chapter contains selected papers presented at the Minisymposium on Interval Methods of the PARA'04 Workshop '' State-of-the-Art in Scientific Computing ''. The emphasis of the workshop was on high-performance computing (HPC). The ongoing development of ever more advanced computers provides...... the potential for solving increasingly difficult computational problems. However, given the complexity of modern computer architectures, the task of realizing this potential needs careful attention. A main concern of HPC is the development of software that optimizes the performance of a given computer....... An important characteristic of the computer performance in scientific computing is the accuracy of the Computation results. Often, we can estimate this accuracy by using traditional statistical techniques. However, in many practical situations, we do not know the probability distributions of different...

Interval timing in genetically modified mice: a simple paradigm.

Science.gov (United States)

Balci, F; Papachristos, E B; Gallistel, C R; Brunner, D; Gibson, J; Shumyatsky, G P

2008-04-01

We describe a behavioral screen for the quantitative study of interval timing and interval memory in mice. Mice learn to switch from a short-latency feeding station to a long-latency station when the short latency has passed without a feeding. The psychometric function is the cumulative distribution of switch latencies. Its median measures timing accuracy and its interquartile interval measures timing precision. Next, using this behavioral paradigm, we have examined mice with a gene knockout of the receptor for gastrin-releasing peptide that show enhanced (i.e. prolonged) freezing in fear conditioning. We have tested the hypothesis that the mutants freeze longer because they are more uncertain than wild types about when to expect the electric shock. The knockouts however show normal accuracy and precision in timing, so we have rejected this alternative hypothesis. Last, we conduct the pharmacological validation of our behavioral screen using d-amphetamine and methamphetamine. We suggest including the analysis of interval timing and temporal memory in tests of genetically modified mice for learning and memory and argue that our paradigm allows this to be done simply and efficiently.

Learned Interval Time Facilitates Associate Memory Retrieval

Science.gov (United States)

van de Ven, Vincent; Kochs, Sarah; Smulders, Fren; De Weerd, Peter

2017-01-01

The extent to which time is represented in memory remains underinvestigated. We designed a time paired associate task (TPAT) in which participants implicitly learned cue-time-target associations between cue-target pairs and specific cue-target intervals. During subsequent memory testing, participants showed increased accuracy of identifying…

Enhancing retention of partial dentures using elastomeric retention rings

Directory of Open Access Journals (Sweden)

Kakkirala Revathi

2015-01-01

Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

Using an integrated automated system to optimize retention and increase frequency of blood donations.

Science.gov (United States)

Whitney, J Garrett; Hall, Robert F

2010-07-01

This study examines the impact of an integrated, automated phone system to reinforce retention and increase frequency of donations among blood donors. Cultivated by incorporating data results over the past 7 years, the system uses computerized phone messaging to contact blood donors with individualized, multilevel notifications. Donors are contacted at planned intervals to acknowledge and recognize their donations, informed where their blood was sent, asked to participate in a survey, and reminded when they are eligible to donate again. The report statistically evaluates the impact of the various components of the system on donor retention and blood donations and quantifies the fiscal advantages to blood centers. By using information and support systems provided by the automated services and then incorporating the phlebotomists and recruiters to reinforce donor retention, both retention and donations will increase. © 2010 American Association of Blood Banks.

Improved Accuracy of Nonlinear Parameter Estimation with LAV and Interval Arithmetic Methods

Directory of Open Access Journals (Sweden)

Humberto Muñoz

2009-06-01

Full Text Available The reliable solution of nonlinear parameter es- timation problems is an important computational problem in many areas of science and engineering, including such applications as real time optimization. Its goal is to estimate accurate model parameters that provide the best fit to measured data, despite small- scale noise in the data or occasional large-scale mea- surement errors (outliers. In general, the estimation techniques are based on some kind of least squares or maximum likelihood criterion, and these require the solution of a nonlinear and non-convex optimiza- tion problem. Classical solution methods for these problems are local methods, and may not be reliable for finding the global optimum, with no guarantee the best model parameters have been found. Interval arithmetic can be used to compute completely and reliably the global optimum for the nonlinear para- meter estimation problem. Finally, experimental re- sults will compare the least squares, l2, and the least absolute value, l1, estimates using interval arithmetic in a chemical engineering application.

A simple, fast, and accurate thermodynamic-based approach for transfer and prediction of gas chromatography retention times between columns and instruments Part III: Retention time prediction on target column.

Science.gov (United States)

Hou, Siyuan; Stevenson, Keisean A J M; Harynuk, James J

2018-03-27

This is the third part of a three-part series of papers. In Part I, we presented a method for determining the actual effective geometry of a reference column as well as the thermodynamic-based parameters of a set of probe compounds in an in-house mixture. Part II introduced an approach for estimating the actual effective geometry of a target column by collecting retention data of the same mixture of probe compounds on the target column and using their thermodynamic parameters, acquired on the reference column, as a bridge between both systems. Part III, presented here, demonstrates the retention time transfer and prediction from the reference column to the target column using experimental data for a separate mixture of compounds. To predict the retention time of a new compound, we first estimate its thermodynamic-based parameters on the reference column (using geometric parameters determined previously). The compound's retention time on a second column (of previously determined geometry) is then predicted. The models and the associated optimization algorithms were tested using simulated and experimental data. The accuracy of predicted retention times shows that the proposed approach is simple, fast, and accurate for retention time transfer and prediction between gas chromatography columns. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Artificial neural network prediction of quantitative structure - retention relationships of polycyclic aromatic hydocarbons in gas chromatography

Directory of Open Access Journals (Sweden)

SNEZANA SREMAC

2005-11-01

Full Text Available A feed-forward artificial neural network (ANN model was used to link molecular structures (boiling points, connectivity indices and molecular weights and retention indices of polycyclic aromatic hydrocarbons (PAHs in linear temperature-programmed gas chromatography. A randomly taken subset of PAH retention data reported by Lee et al. [Anal. Chem. 51 (1979 768], containing retention index data for 30 PAHs, was used to make the ANN model. The prediction ability of the trained ANN was tested on unseen data for 18 PAHs from the same article, as well as on the retention data for 7 PAHs experimentally obtained in this work. In addition, two different data sets with known retention indices taken from the literature were analyzed by the same ANN model. It has been shown that the relative accuracy as the degree of agreement between the measured and the predicted retention indices in all testing sets, for most of the studied PAHs, were within the experimental error margins (±3%.

Retention and Healing Outcomes after Intentional Replantation.

Science.gov (United States)

Cho, Sin-Yeon; Lee, Yoon; Shin, Su-Jung; Kim, Euiseong; Jung, Il-Young; Friedman, Shimon; Lee, Seung-Jong

2016-06-01

Intentional replantation is an alternative to tooth extraction and prosthetic replacement when conventional endodontic treatment modalities are unfeasible or contraindicated. This study assessed tooth retention and healing after intentional replantation and explored predictors of these outcomes. Data of intentional replantation procedures performed between March 2000 and December 2010 were collected prospectively, excluding teeth with preoperative periodontal and root defects. A cohort of 159 teeth was followed up for 0.5-12 years. Retention and healed status without complications (periapical radiolucency, external root resorption, ankylosis, signs/symptoms, probing ≥6 mm) was recorded and analyzed with Kaplan-Meier survival analysis and Cox proportional hazard regression model (P regression identified extraoral time ≤15 minutes as predictor of complication-free healing (P < .04; hazard ratio, 2.767; 95% confidence interval, 1.053-7.272). This prospective cohort study of contemporary intentional replantation suggested a cumulative 12-year retention rate of 93% and healed rate of 77% after 3 years. Healing occurred 1.7 times more frequently in teeth replanted within 15 minutes. Although most complications occurred within 1 year after replantation, follow-up should extend for at least 3 years to capture late complications. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Retention of fissure sealants in young permanent molars affected by dental fluorosis: a 12-month clinical study.

Science.gov (United States)

Hasanuddin, S; Reddy, E R; Manjula, M; Srilaxmi, N; Rani, S T; Rajesh, A

2014-10-01

To evaluate and compare retention and caries occurance following placement of Clinpro and FUJI VII fissure sealants, by two different techniques simultaneously in unsealed, contralateral young permanent molars of 7- to 10-year-old children affected by mild to moderate dental fluorosis at various recall intervals of 1 week, 1, 3, 6 and 12 months. 80 schoolchildren with mild to moderate dental fluorosis were assigned to Group A and Group B with 40 children in each group. In Group A Clinpro fissure sealant and in Group B Fuji VII fissure sealant was used. In both the groups fissure sealants were applied by conventional fissure sealant technique (CST) on one side and enameloplasty sealant technique (EST) on the other side of the same arch. The applied fissure sealants were evaluated clinically for retention and caries incidence. Clinpro fissure sealant showed a retention rate of 95% when compared with Fuji VII (57.5%) at the end of 12 months, which was statistically significant. Regarding techniques, EST showed better results than CST in both the groups. Comparison of groups with respect to retention and techniques at different time periods was performed using Mann-Whitney U test (p < 0.05). Comparison of different time periods with respect to retention and technique in all the groups was performed using Wilcoxon matched pairs test by ranks (p < 0.05). Clinpro fissure sealant showed better retention at all treatment intervals, when compared with Fuji VII. Further follow-up is required to study the efficacy of the fissure sealant placement techniques.

A test of the reward-value hypothesis.

Science.gov (United States)

Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

2017-03-01

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

Robotic fish tracking method based on suboptimal interval Kalman filter

Science.gov (United States)

Tong, Xiaohong; Tang, Chao

2017-11-01

Autonomous Underwater Vehicle (AUV) research focused on tracking and positioning, precise guidance and return to dock and other fields. The robotic fish of AUV has become a hot application in intelligent education, civil and military etc. In nonlinear tracking analysis of robotic fish, which was found that the interval Kalman filter algorithm contains all possible filter results, but the range is wide, relatively conservative, and the interval data vector is uncertain before implementation. This paper proposes a ptimization algorithm of suboptimal interval Kalman filter. Suboptimal interval Kalman filter scheme used the interval inverse matrix with its worst inverse instead, is more approximate nonlinear state equation and measurement equation than the standard interval Kalman filter, increases the accuracy of the nominal dynamic system model, improves the speed and precision of tracking system. Monte-Carlo simulation results show that the optimal trajectory of sub optimal interval Kalman filter algorithm is better than that of the interval Kalman filter method and the standard method of the filter.

Genetic programming based quantitative structure-retention relationships for the prediction of Kovats retention indices.

Science.gov (United States)

Goel, Purva; Bapat, Sanket; Vyas, Renu; Tambe, Amruta; Tambe, Sanjeev S

2015-11-13

The development of quantitative structure-retention relationships (QSRR) aims at constructing an appropriate linear/nonlinear model for the prediction of the retention behavior (such as Kovats retention index) of a solute on a chromatographic column. Commonly, multi-linear regression and artificial neural networks are used in the QSRR development in the gas chromatography (GC). In this study, an artificial intelligence based data-driven modeling formalism, namely genetic programming (GP), has been introduced for the development of quantitative structure based models predicting Kovats retention indices (KRI). The novelty of the GP formalism is that given an example dataset, it searches and optimizes both the form (structure) and the parameters of an appropriate linear/nonlinear data-fitting model. Thus, it is not necessary to pre-specify the form of the data-fitting model in the GP-based modeling. These models are also less complex, simple to understand, and easy to deploy. The effectiveness of GP in constructing QSRRs has been demonstrated by developing models predicting KRIs of light hydrocarbons (case study-I) and adamantane derivatives (case study-II). In each case study, two-, three- and four-descriptor models have been developed using the KRI data available in the literature. The results of these studies clearly indicate that the GP-based models possess an excellent KRI prediction accuracy and generalization capability. Specifically, the best performing four-descriptor models in both the case studies have yielded high (>0.9) values of the coefficient of determination (R(2)) and low values of root mean squared error (RMSE) and mean absolute percent error (MAPE) for training, test and validation set data. The characteristic feature of this study is that it introduces a practical and an effective GP-based method for developing QSRRs in gas chromatography that can be gainfully utilized for developing other types of data-driven models in chromatography science

Fractional intestinal absorption and retention of calcium measured by whole-body counting. Application of a power function model

International Nuclear Information System (INIS)

Pors Nielsen, S.; Baerenholdt, O.; Munck, O.

1975-01-01

By application of a power function model, fractional intestinal calcium absorption was investigated with a new technique involving whole-body counting after successive oral and intravenous administration of standard doses of 47 Ca. The fractional calcium retention 7 days after the oral load of 47 Ca was also measured. Fractional calcium retention averaged 30.3% in normal subjects and 11.5% in 11 patients with intestinal malabsorption. In the same groups fractional calcium absorption averaged 46.6% and 16.4%, respectively. Fractional calcium retention and intestinal calcium absorption were significantly correlated to body surface area, and there was a well-defined relation between fractional retention and absorption of calcium. These studies demonstrate that measurements of fractional retention and fractional intestinal absorption of calcium can be combined by the use of a whole-body counter, that fractional retention and intestinal absorption are proportional to total body surface area and therefore probably also to the total bone mass, and that fractional retention and absorption are so closely interrelated that frational absorption can be estimated from fractional retention with reasonable accuracy in normal subjects. (auth.)

[Reflection of estimating postmortem interval in forensic entomology and the Daubert standard].

Science.gov (United States)

Xie, Dan; Peng, Yu-Long; Guo, Ya-Dong; Cai, Ji-Feng

2013-08-01

Estimating postmortem interval (PMI) is always the emphasis and difficulty in forensic practice. Forensic entomology plays a significant indispensable role. Recently, the theories and technologies of forensic entomology are increasingly rich. But many problems remain in the research and practice. With proposing the Daubert standard, the reliability and accuracy of estimation PMI by forensic entomology need more demands. This review summarizes the application of the Daubert standard in several aspects of ecology, quantitative genetics, population genetics, molecular biology, and microbiology in the practice of forensic entomology. It builds a bridge for basic research and forensic practice to provide higher accuracy for estimating postmortem interval by forensic entomology.

Deuterium in-vessel retention characterisation through the use of particle balance on Tore Supra

International Nuclear Information System (INIS)

Bucalossi, J.; Brosset, C.; Pegourie, B.; Tsitrone, E.; Dufour, E.; Eckedahl, A.; Geraud, A.; Goniche, M.; Gunn, J.; Loarer, T.; Monier-Garbet, P.; Vallet, J.C.; Vartanian, S.

2007-01-01

Fuel retention inside plasma facing components will be a crucial issue not only in fusion reactors of the future, but also in ITER. The estimation of the fraction of the fuel which remains trapped inside the vessel is quite a difficult task. Particle balance analysis provides information for the whole vacuum chamber as a function of time and can be use to monitor the tritium in-vessel retention in real-time. On Tore Supra with a careful choice and position of pressure sensors, proper calibration procedures, the accuracy of the balance is around 10%. Particle balance analysis have been performed on many long pulse discharges and deuterium in-vessel retention has been found to be a constant around 5 x 10 20 D/s after several minutes of plasma. The evolution of the retention rate with plasma parameters indicates that deuterium bulk implantation and diffusion could dominate codeposition with carbon atoms. Particle balance is a powerful tool that should be implemented in ITER

Factors affecting the retention of methyl iodide by iodide-impregnated carbon

International Nuclear Information System (INIS)

Hyder, M.L.; Malstrom, R.A.

1991-01-01

This paper comprises two sets of studies of methyl iodide retention by iodide-impregnated carbon. In the first of these, the retention of the methyl iodide on the carbon surface and its subsequent evolution were observed directly by a technique of combustion and phosphorescence. In the second, the methyl iodide retention in a standard test was compared with surface area measurements and the concentration of unreacted iodine. A correlation among these parameters was identified and characterized. Carbon quality was varied through the selection of used material with differing service histories. Air from the Savannah River Site reactor buildings is vented through carbon beds for control of radioiodine before release to the atmosphere. The carbon used is North American Carbon Co. type GX-176 coconut shell carbon impregnated with 1% triethylenedimaine (TEDA) and 2% potassium iodide by weight. Replacement intervals for the carbon have been as long as thirty months. Analysis of samples withdrawn at much shorter times has shown that the TEDA is lost after a few months, and the performance of the carbon for methyl iodide retention is dependent on the iodide impregnant. Efficient methyl iodide retention is not a requirement for carbon in this service; however, methyl iodide retention as measured by the ASTM Test D3803 (method B) has been found to correlate well with other desirable properties of the carbon such as radiation stability. The studies undertaken here were intended to shed light on the changes taking place in this carbon during long-term service and to provide a basis for simpler measurements of carbon quality

Identification of atrial fibrillation using electrocardiographic RR-interval difference

Science.gov (United States)

Eliana, M.; Nuryani, N.

2017-11-01

Automated detection of atrial fibrillation (AF) is an interesting topic. It is an account of very dangerous, not only as a trigger of embolic stroke, but it’s also related to some else chronical disease. In this study, we analyse the presence of AF by determining irregularities of RR-interval. We utilize the interval comparison to measure the degree of irregularities of RR-interval in a defined segment. The series of RR-interval is segmented with the length of 10 of them. In this study, we use interval comparison for the method. We were comparing all of the intervals there each other. Then we put the threshold to define the low difference and high difference (δ). A segment is defined as AF or Normal Sinus by the number of high δ, so we put the tolerance (β) of high δ there. We have used this method to test the 23 patients data from MIT-BIH. Using the approach and the clinical data we find accuracy, sensitivity, and specificity of 84.98%, 91.99%, and 77.85% respectively.

Quartz exposure, retention, and early silicosis in sheep.

Science.gov (United States)

Bégin, R; Dufresne, A; Cantin, A; Possmayer, F; Sébastien, P; Fabi, D; Bilodeau, G; Martel, M; Bisson, D; Pietrowski, B

1989-05-01

The purposes of this study were (1) to investigate the chronology of events in cellular and biochemical changes thought to be important in the development of silicosis, (2) to relate these to changes in lung function and radiograph, and (3) to evaluate the relation of quartz exposure and retention to individual response leading to early silicosis. Thirty-six sheep were exposed by repeated intratracheal infusion at 10-day intervals to 100 mg Minusil-5 in 100 ml saline (Si group), and 10 sheep were exposed at the same intervals to 100 ml saline (control). All sheep were investigated at 3-month intervals by chest radiograph, lung function, and lung lavage. At month 9, chest radiograph score of parenchymal opacities was significantly increased at 2.8 +/- 0.6 versus 0.4 +/- 0.4 in the Si group (p less than .05), establishing early radiologic silicosis. Lung function was significantly altered with reduction in lung compliance, vital capacity, and diffusion capacity (p less than .05). Lung lavage cellularity revealed significant increase in total cells (X 2.5), macrophages (X3), and neutrophils (X3). Albumin in BAL remained at the control level. Fibronectin production was significantly increased, as was the fibroblast growth activity, without significant change in procollagen 3 at this early stage of disease. Total phospholipids were significantly elevated in the Si-exposed sheep, and the profile demonstrated an increase in all the phospholipid components. Spontaneous release of hydrogen peroxide by alveolar cells was not increased, but in the presence of phorbol myristate acetate (PMA) higher levels of peroxide were found in the quartz-exposed sheep (p less than .05). The cellular and biochemical alterations of lung lavage preceded other changes. At month 12, there were good correlations (r greater than .49, p less than .001) between parameters evaluating related phenomena but poor correlations between measurements evaluating different aspects of the disorder. To

Use of in situ volumetric water content at field capacity to improve prediction of soil water retention properties

OpenAIRE

Al Majou , Hassan; Bruand , Ary; Duval , Odile

2008-01-01

International audience; Use of in situ volumetric water content at field capacity to improve prediction of soil water retention properties. Most pedotransfer functions (PTFs) developed over the last three decades to generate water retention characteristics use soil texture, bulk density and organic carbon content as predictors. Despite of the high number of PTFs published, most being class- or continuous-PTFs, accuracy of prediction remains limited. In this study, we compared the performance ...

Event- and interval-based measurement of stuttering: a review.

Science.gov (United States)

Valente, Ana Rita S; Jesus, Luis M T; Hall, Andreia; Leahy, Margaret

2015-01-01

Event- and interval-based measurements are two different ways of computing frequency of stuttering. Interval-based methodology emerged as an alternative measure to overcome problems associated with reproducibility in the event-based methodology. No review has been made to study the effect of methodological factors in interval-based absolute reliability data or to compute the agreement between the two methodologies in terms of inter-judge, intra-judge and accuracy (i.e., correspondence between raters' scores and an established criterion). To provide a review related to reproducibility of event-based and time-interval measurement, and to verify the effect of methodological factors (training, experience, interval duration, sample presentation order and judgment conditions) on agreement of time-interval measurement; in addition, to determine if it is possible to quantify the agreement between the two methodologies The first two authors searched for articles on ERIC, MEDLINE, PubMed, B-on, CENTRAL and Dissertation Abstracts during January-February 2013 and retrieved 495 articles. Forty-eight articles were selected for review. Content tables were constructed with the main findings. Articles related to event-based measurements revealed values of inter- and intra-judge greater than 0.70 and agreement percentages beyond 80%. The articles related to time-interval measures revealed that, in general, judges with more experience with stuttering presented significantly higher levels of intra- and inter-judge agreement. Inter- and intra-judge values were beyond the references for high reproducibility values for both methodologies. Accuracy (regarding the closeness of raters' judgements with an established criterion), intra- and inter-judge agreement were higher for trained groups when compared with non-trained groups. Sample presentation order and audio/video conditions did not result in differences in inter- or intra-judge results. A duration of 5 s for an interval appears to be

Accuracy and responses of genomic selection on key traits in apple breeding

NARCIS (Netherlands)

Muranty, Hélène; Troggio, Michela; Sadok, Ben Inès; Rifaï, Al Mehdi; Auwerkerken, Annemarie; Banchi, E.; Velasco, Riccardo; Stevanato, P.; Weg, van de W.E.; Guardo, Di M.; Kumar, S.; Laurens, François; Bink, M.C.A.M.

2015-01-01

The application of genomic selection in fruit tree crops is expected to enhance breeding efficiency by increasing prediction accuracy, increasing selection intensity and decreasing generation interval. The objectives of this study were to assess the accuracy of prediction and selection response in

Time-to-code converter with selection of time intervals on duration

International Nuclear Information System (INIS)

Atanasov, I.Kh.; Rusanov, I.R.; )

2001-01-01

Identification of elementary particles on the basis of time-of-flight represents the important approach of the preliminary selection procedure. Paper describes a time-to-code converter with preliminary selection of the measured time intervals as to duration. It consists of a time-to-amplitude converter, an analog-to-digital converter, a unit of selection of time intervals as to duration, a unit of total reset and CAMAC command decoder. The time-to-code converter enables to measure time intervals with 100 ns accuracy within 0-100 ns range. Output code capacity is of 10. Selection time constitutes 50 ns [ru

Prediction of gradient retention data for hydrophilic interaction liquid chromatographic separation of native and fluorescently labeled oligosaccharides.

Science.gov (United States)

Vaňková, Nikola; Česla, Petr

2017-02-17

In this work, we have investigated the predictive properties of mixed-mode retention model and oligomeric mixed-mode model, taking into account the contribution of monomeric units to the retention, in hydrophilic interaction liquid chromatography. The gradient retention times of native maltooligosaccharides and their fluorescent derivatives were predicted in the oligomeric series with number of monomeric glucose units in the range from two to seven. The maltooligosaccharides were separated on a packed column with carbamoyl-bonded silica stationary phase and 15 gradient profiles with different initial and final mobile phase composition were used with the gradient times 5; 7.5 and 10min. The predicted gradient retention times were compared for calculations based on isocratic retention data and gradient retention data, which provided better accuracy of the results. By comparing two different mobile phase additives, the more accurate retention times were predicted in mobile phases containing ammonium acetate. The acidic derivatives, prepared by reaction of an oligosaccharide with 2-aminobenzoic acid or 8-aminonaphthalene-1,3,6-trisulfonic acid, provided more accurate predictions of the retention data in comparison to native oligosaccharides or their neutral derivatives. The oligomeric mixed-mode model allowed prediction of gradient retention times using only one gradient profile, which significantly speeded-up the method development. Copyright © 2017 Elsevier B.V. All rights reserved.

Factors Related to the Accuracy of Self-Reported Dietary Intake of Children Aged 6 to 12 Years Elicited with Interviews: A Systematic Review.

Science.gov (United States)

Sharman, Stefanie J; Skouteris, Helen; Powell, Martine B; Watson, Brittany

2016-01-01

Understanding the relationship between children's dietary consumption and health is important. As such, it is crucial to explore factors related to the accuracy of children's reports of what they consumed. The objective was to evaluate factors related to the accuracy of self-reported dietary intake information elicited by interview methods from children aged 6 to 12 years. A systematic review of English articles using PsycINFO, PsycARTICLES, PsycEXTRA, PsycBOOKS, CINAHL Complete, Global Health, and MEDLINE Complete was performed. Search terms included interview, diet, children, and recall; studies were limited to those published from 1970 onward. Additional studies were identified using the reference lists of published articles. Studies that assessed children's dietary intake using direct observation, doubly labeled water, or the double-portion method and compared it with their recall of that intake (unassisted by parents) using an interview were included. The 45 studies that met the inclusion criteria showed that specific interview techniques designed to enhance children's recall accuracy had little effect. Rather, the timing of the interview appeared most important: The shorter the retention interval between children's consumption and their recall, the more accurate their memories. Children's age, body mass index, social desirability, food preferences, and cognitive ability were also related to accuracy. Factors related to the accuracy of children's dietary reporting should be taken into consideration when asking about consumption. Further research is required to examine whether other interview techniques, such as those developed to enhance children's recall of repeated staged events, can improve children's dietary reporting accuracy. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

INTERVAL STATE ESTIMATION FOR SINGULAR DIFFERENTIAL EQUATION SYSTEMS WITH DELAYS

Directory of Open Access Journals (Sweden)

T. A. Kharkovskaia

2016-07-01

Full Text Available The paper deals with linear differential equation systems with algebraic restrictions (singular systems and a method of interval observer design for this kind of systems. The systems contain constant time delay, measurement noise and disturbances. Interval observer synthesis is based on monotone and cooperative systems technique, linear matrix inequations, Lyapunov function theory and interval arithmetic. The set of conditions that gives the possibility for interval observer synthesis is proposed. Results of synthesized observer operation are shown on the example of dynamical interindustry balance model. The advantages of proposed method are that it is adapted to observer design for uncertain systems, if the intervals of admissible values for uncertain parameters are given. The designed observer is capable to provide asymptotically definite limits on the estimation accuracy, since the interval of admissible values for the object state is defined at every instant. The obtained result provides an opportunity to develop the interval estimation theory for complex systems that contain parametric uncertainty, varying delay and nonlinear elements. Interval observers increasingly find applications in economics, electrical engineering, mechanical systems with constraints and optimal flow control.

Measurement of subcritical multiplication by the interval distribution method

International Nuclear Information System (INIS)

Nelson, G.W.

1985-01-01

The prompt decay constant or the subcritical neutron multiplication may be determined by measuring the distribution of the time intervals between successive neutron counts. The distribution data is analyzed by least-squares fitting to a theoretical distribution function derived from a point reactor probability model. Published results of measurements with one- and two-detector systems are discussed. Data collection times are shorter, and statistical errors are smaller the nearer the system is to delayed critical. Several of the measurements indicate that a shorter data collection time and higher accuracy are possible with the interval distribution method than with the Feynman variance method

Hypoxia positron emission tomography imaging: combining information on perfusion and tracer retention to improve hypoxia specificity

DEFF Research Database (Denmark)

Busk, Morten; Munk, Ole L; Jakobsen, Steen S

2017-01-01

BACKGROUND: Static positron emission tomography (PET) allows mapping of tumor hypoxia, but low resolution and slow tracer retention/clearance results in poor image contrast and the risk of missing areas where hypoxic cells and necrosis are intermixed. Fully dynamic PET may improve accuracy but scan...

Multiple coding strategies in the retention of musical tones by possessors of absolute pitch.

Science.gov (United States)

Zatorre, R J; Beckett, C

1989-09-01

Eighteen musicians with absolute pitch (AP) confirmed by screening tests participated in tonal and verbal short-term-retention tasks. In the tonal task, subjects identified three successive piano tones by their letter names. Recall of these note names after 18 sec of counting backwards was near perfect. Recall after an 18-sec delay filled with random piano tones was also near perfect. In contrast, the same subjects demonstrated significant forgetting when required to retain letter trigrams while counting backwards for 18 sec. These results were essentially replicated in a second experiment using longer (27 sec) retention intervals, a more demanding verbal interference task, and an active musical interference task (singing a descending scale). We interpret these results as indicating that retention of note names by possessors of AP is not limited to verbal encoding; rather, multiple codes (e.g., auditory, kinesthetic, and visual imagery) are probably used.

When Does Testing Enhance Retention? A Distribution-Based Interpretation of Retrieval as a Memory Modifier

Science.gov (United States)

Halamish, Vered; Bjork, Robert A.

2011-01-01

Tests, as learning events, can enhance subsequent recall more than do additional study opportunities, even without feedback. Such advantages of testing tend to appear, however, only at long retention intervals and/or when criterion tests stress recall, rather than recognition, processes. We propose that the interaction of the benefits of testing…

The acquisition and retention of ECG interpretation skills after a standardized web-based ECG tutorial

DEFF Research Database (Denmark)

Rolskov Bojsen, Signe; Räder, Sune Bernd Emil Werner; Holst, Anders Gaardsdal

2015-01-01

BACKGROUND: Electrocardiogram (ECG) interpretation is of great importance for patient management. However, medical students frequently lack proficiency in ECG interpretation and rate their ECG training as inadequate. Our aim was to examine the effect of a standalone web-based ECG tutorial...... and to assess the retention of skills using multiple follow-up intervals. METHODS: 203 medical students were included in the study. All participants completed a pre-test, an ECG tutorial, and a post-test. The participants were also randomised to complete a retention-test after short (2-4 weeks), medium (10.......6), respectively). When comparing the pre-test to retention-test delta scores, junior students had learned significantly more than senior students (junior students improved 10.7 points and senior students improved 4.7 points, p = 0.003). CONCLUSION: A standalone web-based ECG tutorial can be an effective means...

Point and interval forecasts of mortality rates and life expectancy: A comparison of ten principal component methods

Directory of Open Access Journals (Sweden)

Han Lin Shang

2011-07-01

Full Text Available Using the age- and sex-specific data of 14 developed countries, we compare the point and interval forecast accuracy and bias of ten principal component methods for forecasting mortality rates and life expectancy. The ten methods are variants and extensions of the Lee-Carter method. Based on one-step forecast errors, the weighted Hyndman-Ullah method provides the most accurate point forecasts of mortality rates and the Lee-Miller method is the least biased. For the accuracy and bias of life expectancy, the weighted Hyndman-Ullah method performs the best for female mortality and the Lee-Miller method for male mortality. While all methods underestimate variability in mortality rates, the more complex Hyndman-Ullah methods are more accurate than the simpler methods. The weighted Hyndman-Ullah method provides the most accurate interval forecasts for mortality rates, while the robust Hyndman-Ullah method provides the best interval forecast accuracy for life expectancy.

Retention of external and internal markers by southern pine beetles (Coleoptera: Scolytidae) during gallery

Science.gov (United States)

Douglas J. Rhodes; Jane Leslie Hayes; Chris Steiner

1998-01-01

If retained, markers used in mark-release-recapture studies of bark beetle dispersal could provide valuable tools in the determination of post-dispersal fate. Retention of the internal marker rubidium (Rb) and of the external marker fluorescent powder during egg gallery construction, oviposition, and feeding were quantified at intervals from 0 to 96 hours by allowing...

Using an inverse modelling approach to evaluate the water retention in a simple water harvesting technique

Directory of Open Access Journals (Sweden)

K. Verbist

2009-10-01

Full Text Available In arid and semi-arid zones, runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Nevertheless, few efforts were observed to quantify the water harvesting processes of these techniques and to evaluate their efficiency. In this study, a combination of detailed field measurements and modelling with the HYDRUS-2D software package was used to visualize the effect of an infiltration trench on the soil water content of a bare slope in northern Chile. Rainfall simulations were combined with high spatial and temporal resolution water content monitoring in order to construct a useful dataset for inverse modelling purposes. Initial estimates of model parameters were provided by detailed infiltration and soil water retention measurements. Four different measurement techniques were used to determine the saturated hydraulic conductivity (K_sat independently. The tension infiltrometer measurements proved a good estimator of the K_sat value and a proxy for those measured under simulated rainfall, whereas the pressure and constant head well infiltrometer measurements showed larger variability. Six different parameter optimization functions were tested as a combination of soil-water content, water retention and cumulative infiltration data. Infiltration data alone proved insufficient to obtain high model accuracy, due to large scatter on the data set, and water content data were needed to obtain optimized effective parameter sets with small confidence intervals. Correlation between the observed soil water content and the simulated values was as high as R²=0.93 for ten selected observation points used in the model calibration phase, with overall correlation for the 22 observation points equal to 0.85. The model results indicate that the infiltration trench has a

Prediction of the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient-elution conditions.

Science.gov (United States)

D'Archivio, Angelo Antonio; Maggi, Maria Anna; Ruggieri, Fabrizio

2014-08-01

In this paper, a multilayer artificial neural network is used to model simultaneously the effect of solute structure and eluent concentration profile on the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient elution. The retention data of 24 triazines, including common herbicides and their metabolites, are collected under 13 different elution modes, covering the following experimental domain: starting acetonitrile volume fraction ranging between 40 and 60% and gradient slope ranging between 0 and 1% acetonitrile/min. The gradient parameters together with five selected molecular descriptors, identified by quantitative structure-retention relationship modelling applied to individual separation conditions, are the network inputs. Predictive performance of this model is evaluated on six external triazines and four unseen separation conditions. For comparison, retention of triazines is modelled by both quantitative structure-retention relationships and response surface methodology, which describe separately the effect of molecular structure and gradient parameters on the retention. Although applied to a wider variable domain, the network provides a performance comparable to that of the above "local" models and retention times of triazines are modelled with accuracy generally better than 7%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interval selection with machine-dependent intervals

OpenAIRE

Bohmova K.; Disser Y.; Mihalak M.; Widmayer P.

2013-01-01

We study an offline interval scheduling problem where every job has exactly one associated interval on every machine. To schedule a set of jobs, exactly one of the intervals associated with each job must be selected, and the intervals selected on the same machine must not intersect.We show that deciding whether all jobs can be scheduled is NP-complete already in various simple cases. In particular, by showing the NP-completeness for the case when all the intervals associated with the same job...

The effect of 2,3-dimercaptopropane sodium sulfonate on mercury retention in rats in relation to age

International Nuclear Information System (INIS)

Kostial, K.; Kargacin, B.; Blanusa, M.; Landeka, M.

1984-01-01

The effectiveness of DMPS (sodium 2,3-dimercaptopropane-l-sulfonate) in reducing inorganic mercury retention was studied in 2-, 6-, and 28-week-old albino rats. 203 Hg was administered IP. The chelating agent DMPS was administered by injection at a dose of 250 μmol/kg body weight three times, 1 day after 203 Hg administration and at 24 h intervals thereafter. The whole body retention determined 1, 2, 3, and 6 days after 203 Hg administration showed that DMPS decreased the body retention of mercury in all age groups, being about twice as effective in adult compared to suckling rats. The reduced effectiveness was due to the reduced efficacy of DMPS in reducing kidney retention in young animals. In other organs the effectiveness of DMPS was not age dependent. These and previous results obtained with different chelating agents and other metals indicate that age might be an important factor in chelation therapy in general. (orig.)

Lack of spacing effects during piano learning.

Directory of Open Access Journals (Sweden)

Melody Wiseheart

Full Text Available Spacing effects during retention of verbal information are easily obtained, and the effect size is large. Relatively little evidence exists on whether motor skill retention benefits from distributed practice, with even less evidence on complex motor skills. We taught a 17-note musical sequence on a piano to individuals without prior formal training. There were five lags between learning episodes: 0-, 1-, 5-, 10-, and 15-min. After a 5-min retention interval, participants' performance was measured using three criteria: accuracy of note playing, consistency in pressure applied to the keys, and consistency in timing. No spacing effect was found, suggesting that the effect may not always be demonstrable for complex motor skills or non-verbal abilities (timing and motor skills. Additionally, we taught short phrases from five songs, using the same set of lags and retention interval, and did not find any spacing effect for accuracy of song reproduction. Our findings indicate that although the spacing effect is one of the most robust phenomena in the memory literature (as demonstrated by verbal learning studies, the effect may vary when considered in the novel realm of complex motor skills such as piano performance.

Lack of spacing effects during piano learning.

Science.gov (United States)

Wiseheart, Melody; D'Souza, Annalise A; Chae, Jacey

2017-01-01

Spacing effects during retention of verbal information are easily obtained, and the effect size is large. Relatively little evidence exists on whether motor skill retention benefits from distributed practice, with even less evidence on complex motor skills. We taught a 17-note musical sequence on a piano to individuals without prior formal training. There were five lags between learning episodes: 0-, 1-, 5-, 10-, and 15-min. After a 5-min retention interval, participants' performance was measured using three criteria: accuracy of note playing, consistency in pressure applied to the keys, and consistency in timing. No spacing effect was found, suggesting that the effect may not always be demonstrable for complex motor skills or non-verbal abilities (timing and motor skills). Additionally, we taught short phrases from five songs, using the same set of lags and retention interval, and did not find any spacing effect for accuracy of song reproduction. Our findings indicate that although the spacing effect is one of the most robust phenomena in the memory literature (as demonstrated by verbal learning studies), the effect may vary when considered in the novel realm of complex motor skills such as piano performance.

Self-disclosure of HIV status, disclosure counseling, and retention in HIV care in Cameroon.

Science.gov (United States)

Breger, Tiffany L; Newman, Jamie E; Mfangam Molu, Brigitte; Akam, Wilfred; Balimba, Ashu; Atibu, Joseph; Kiumbu, Modeste; Azinyue, Innocent; Hemingway-Foday, Jennifer; Pence, Brian W

2017-07-01

Poor retention in care is common among HIV-positive adults in sub-Saharan Africa settings and remains a key barrier to HIV management. We quantify the associations of disclosure of HIV status and referral to disclosure counseling with successful retention in care using data from three Cameroon clinics participating in the Phase 1 International epidemiologic Databases to Evaluate AIDS Central Africa cohort. Of 1646 patients newly initiating antiretroviral therapy between January 2008 and January 2011, 43% were retained in care following treatment initiation. Self-disclosure of HIV status to at least one person prior to treatment initiation was associated with a minimal increase in the likelihood of being retained in care (risk ratio [RR] = 1.14; 95% confidence interval (CI): 0.94, 1.38). However, referral to disclosure counseling was associated with a moderate increase in retention (RR = 1.37; 95% CI: 1.21, 1.55) and was not significantly modified by prior disclosure status (p = .3). Our results suggest that while self-disclosure may not significantly improve retention among patients receiving care at these Cameroon sites, counseling services may play an important role regardless of prior disclosure status.

Retention and features of deuterium detrapping from radiation-induced damages in steels

International Nuclear Information System (INIS)

Tolstolutskaya, G.D.; Ruzhytskiy, V.V.; Karpov, S.A.; Kopanets, I.E.

2009-01-01

The accelerators and ion-beam analysis techniques are used for simulation of displacement damage and detailed investigation of distribution profiles of damage and impurity gas atoms (especially helium and hydrogen) in the irradiation of targets for a wide ranges of doses and particle energies. The influence of preimplanted helium and heavy ion-induced damage on deuterium trapping in austenitic and ferritic/martensitic steels was studied. The results obtained for 18Cr10NiTi stainless steel show that ion-implanted deuterium is weakly trapped by defects produced in 5 keV D + displacement cascades. The effective trapping temperature interval is between 300 and 600 K. The characteristics of trapping and the temperature range of hydrogen isotopes retention in traps formed by prior implantation of helium depend on the concentration of implanted helium and on the type of defects developed. The formation of helium bubbles in 18Cr10NiTi steel causes an order of magnitude increase in the content of retained deuterium atoms in the range of temperature 300-600 K and extends the interval of effective trapping temperatures to 1000 K. Energetic heavy-ion irradiation (1.4 MeV Ar + ) has been used for modeling defect cluster formation under displacement cascade conditions to simulate fusion reactor environments. It was found that retention of hydrogen and deuterium strongly increased in this case. It is shown that the presence of a surface-passive film considerably shifts the gas release interval to higher temperatures and reduces the deuterium surface recombination coefficient by several orders of magnitude.

An approach to solve group-decision-making problems with ordinal interval numbers.

Science.gov (United States)

Fan, Zhi-Ping; Liu, Yang

2010-10-01

The ordinal interval number is a form of uncertain preference information in group decision making (GDM), while it is seldom discussed in the existing research. This paper investigates how the ranking order of alternatives is determined based on preference information of ordinal interval numbers in GDM problems. When ranking a large quantity of ordinal interval numbers, the efficiency and accuracy of the ranking process are critical. A new approach is proposed to rank alternatives using ordinal interval numbers when every ranking ordinal in an ordinal interval number is thought to be uniformly and independently distributed in its interval. First, we give the definition of possibility degree on comparing two ordinal interval numbers and the related theory analysis. Then, to rank alternatives, by comparing multiple ordinal interval numbers, a collective expectation possibility degree matrix on pairwise comparisons of alternatives is built, and an optimization model based on this matrix is constructed. Furthermore, an algorithm is also presented to rank alternatives by solving the model. Finally, two examples are used to illustrate the use of the proposed approach.

Whole-body retention of 65Zn during pregnancy and lactation, and its secretion into milk in mice

International Nuclear Information System (INIS)

Matsusaka, N.

1978-01-01

The relationship between the maternal whole-body retention of 65 Zn during pregnancy and lactation was studied in mice. Mice administered 65 Zn late in gestation had extremely high retention before parturition which was followed by an abrupt decrease after parturition. The magnitude of the abrupt decrease of maternal body burden becomes smaller with an increase in the interval between administration of isotope and parturition, i.e., the greater the interval between administration and parturition, the smaller the fetal uptake of 65 Zn during intrauterine life. The amount of 65 Zn secreted into milk was estimated from the pup's body burden during the nursing period. When 65 Zn was administered 5 days after parturition to dams nursing eight pups each, the maximum body burden of the litter reached 64% of the initial dose 10 days after injection. In mouse dams, the secretion of 65 Zn in milk is an important elimination pathway in addition to excretion in feces

Task-Based Variability in Children's Singing Accuracy

Science.gov (United States)

Nichols, Bryan E.

2016-01-01

The purpose of this study was to explore the effect of task demands on children's singing accuracy. A 2 × 4 factorial design was used to examine the performance of fourth-grade children (N = 120) in solo and doubled response conditions. Each child sang four task types: single pitch, interval, pattern, and the song "Jingle Bells." The…

Role of male partner involvement in ART retention and adherence in Malawi's Option B+ program.

Science.gov (United States)

Wesevich, Austin; Mtande, Tiwonge; Saidi, Friday; Cromwell, Elizabeth; Tweya, Hannock; Hosseinipour, Mina C; Hoffman, Irving; Miller, William C; Rosenberg, Nora E

2017-11-01

Malawi's Option B+ program provides all HIV-infected pregnant women free lifelong antiretroviral therapy (ART), but challenges remain regarding retention and ART adherence, potentially due to male partner barriers. We explored relationships between male partner involvement and Option B+ retention and adherence. In 2014, a randomized controlled trial in Malawi compared male recruitment strategies for couple HIV testing and counseling (cHTC) at an antenatal clinic. This secondary analysis was conducted among the entire cohort (N = 200) of women, irrespective of randomization status. We assessed whether cHTC attendance, early disclosure of HIV-positive status, and partner ART reminders were associated with retention and adherence at one month after starting treatment. Retention was defined as attending HIV clinic follow-up within one day of running out of pills. Adherence was defined as taking ≥95% of ARTs by pill count. We used binomial regression to calculate adjusted risk ratios (aRR) and 95% confidence intervals (CI). Median female age was 26 years. Most women (79%) were retained; of these, 68% were adherent. Receiving cHTC was associated with improved retention (aRR 1.33, 95% CI 1.12, 1.59). Receiving male partner ART reminders was weakly associated with retention (aRR 1.16, 95% CI 0.96, 1.39). Disclosure within one day was not associated with retention (aRR 1.08, 95% CI: 0.91, 1.28). Among those who were retained, these three behaviors were not associated with improved 95% adherence. CHTC could play an important role in improving Option B+ retention. Increasing cHTC participation and enhancing adherence-related messages within cHTC are important.

Time-variant random interval natural frequency analysis of structures

Science.gov (United States)

Wu, Binhua; Wu, Di; Gao, Wei; Song, Chongmin

2018-02-01

This paper presents a new robust method namely, unified interval Chebyshev-based random perturbation method, to tackle hybrid random interval structural natural frequency problem. In the proposed approach, random perturbation method is implemented to furnish the statistical features (i.e., mean and standard deviation) and Chebyshev surrogate model strategy is incorporated to formulate the statistical information of natural frequency with regards to the interval inputs. The comprehensive analysis framework combines the superiority of both methods in a way that computational cost is dramatically reduced. This presented method is thus capable of investigating the day-to-day based time-variant natural frequency of structures accurately and efficiently under concrete intrinsic creep effect with probabilistic and interval uncertain variables. The extreme bounds of the mean and standard deviation of natural frequency are captured through the embedded optimization strategy within the analysis procedure. Three particularly motivated numerical examples with progressive relationship in perspective of both structure type and uncertainty variables are demonstrated to justify the computational applicability, accuracy and efficiency of the proposed method.

The Optimal Confidence Intervals for Agricultural Products’ Price Forecasts Based on Hierarchical Historical Errors

Directory of Open Access Journals (Sweden)

Yi Wang

2016-12-01

Full Text Available With the levels of confidence and system complexity, interval forecasts and entropy analysis can deliver more information than point forecasts. In this paper, we take receivers’ demands as our starting point, use the trade-off model between accuracy and informativeness as the criterion to construct the optimal confidence interval, derive the theoretical formula of the optimal confidence interval and propose a practical and efficient algorithm based on entropy theory and complexity theory. In order to improve the estimation precision of the error distribution, the point prediction errors are STRATIFIED according to prices and the complexity of the system; the corresponding prediction error samples are obtained by the prices stratification; and the error distributions are estimated by the kernel function method and the stability of the system. In a stable and orderly environment for price forecasting, we obtain point prediction error samples by the weighted local region and RBF (Radial basis function neural network methods, forecast the intervals of the soybean meal and non-GMO (Genetically Modified Organism soybean continuous futures closing prices and implement unconditional coverage, independence and conditional coverage tests for the simulation results. The empirical results are compared from various interval evaluation indicators, different levels of noise, several target confidence levels and different point prediction methods. The analysis shows that the optimal interval construction method is better than the equal probability method and the shortest interval method and has good anti-noise ability with the reduction of system entropy; the hierarchical estimation error method can obtain higher accuracy and better interval estimation than the non-hierarchical method in a stable system.

Influence of transportation cost on long-term retention in clinic for HIV patients in rural Haiti.

Science.gov (United States)

Sowah, Leonard A; Turenne, Franck V; Buchwald, Ulrike K; Delva, Guesly; Mesidor, Romaine N; Dessaigne, Camille G; Previl, Harold; Patel, Devang; Edozien, Anthony; Redfield, Robert R; Amoroso, Anthony

2014-12-01

With improved access to antiretroviral therapy in resource-constrained settings, long-term retention in HIV clinics has become an important means of reducing costs and improving outcomes. Published data on retention in HIV clinics beyond 24 months are, however, limited. In our clinic in rural Haiti, we hypothesized that individuals residing in locations with higher transportation costs to clinic would have poorer retention than those who had lower costs. We used a retrospective cohort design to evaluate potential predictors of HIV clinic retention. Patient information was abstracted from the electronic medical records. Cox proportional hazards regression was used to identify independent predictors of 4-year clinic retention. There were 410 patients in our cohort, 266 (64.9%) females and 144 (35.1%) males. Forty-five (11%) patients lived in locations with transportation costs >$2. Males were 1.5 times more likely to live in municipalities with transportation costs to clinic of >$2. Multivariate analysis suggested that age transportation cost were independent predictors of loss to follow-up (LTFU): risk ratio of 2.98, 95% confidence interval (CI): 1.73 to 4.96, P transportation costs greater than $2 were 1.9 times more likely to be lost to care compared with those who paid less for transportation. HIV treatment programs in resource-constrained settings may need to pay closer attention to issues related to transportation cost to improve patient retention.

Trajectory Optimization Based on Multi-Interval Mesh Refinement Method

Directory of Open Access Journals (Sweden)

Ningbo Li

2017-01-01

Full Text Available In order to improve the optimization accuracy and convergence rate for trajectory optimization of the air-to-air missile, a multi-interval mesh refinement Radau pseudospectral method was introduced. This method made the mesh endpoints converge to the practical nonsmooth points and decreased the overall collocation points to improve convergence rate and computational efficiency. The trajectory was divided into four phases according to the working time of engine and handover of midcourse and terminal guidance, and then the optimization model was built. The multi-interval mesh refinement Radau pseudospectral method with different collocation points in each mesh interval was used to solve the trajectory optimization model. Moreover, this method was compared with traditional h method. Simulation results show that this method can decrease the dimensionality of nonlinear programming (NLP problem and therefore improve the efficiency of pseudospectral methods for solving trajectory optimization problems.

Retention of a resin-based sealant and a glass ionomer used as a fissure sealant: A comparative clinical study

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Subramaniam P

2008-09-01

Full Text Available Sealing occlusal pits and fissures with resin-based sealants is a proven method of preventing occlusal caries. Retention of the sealant is very essential for its efficiency. This study evaluated the retention of glass ionomer used as a fissure sealant when compared to a self-cure resin-based sealant. One hundred and seven children between the ages of 6-9 years, with all four newly erupted permanent first molars were selected. Two permanent first molars on one side of the mouth were sealed with Delton, a resin-based sealant, and the contralateral two permanent first molars were sealed with Fuji VII glass ionomer cement. Evaluation of sealant retention was performed at regular intervals over 12 months, using Simonsen′s criteria. At the end of the study period, the retention of the resin sealant was seen to be superior to that of the glass ionomer sealant.

Molecular descriptor subset selection in theoretical peptide quantitative structure-retention relationship model development using nature-inspired optimization algorithms.

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Žuvela, Petar; Liu, J Jay; Macur, Katarzyna; Bączek, Tomasz

2015-10-06

In this work, performance of five nature-inspired optimization algorithms, genetic algorithm (GA), particle swarm optimization (PSO), artificial bee colony (ABC), firefly algorithm (FA), and flower pollination algorithm (FPA), was compared in molecular descriptor selection for development of quantitative structure-retention relationship (QSRR) models for 83 peptides that originate from eight model proteins. The matrix with 423 descriptors was used as input, and QSRR models based on selected descriptors were built using partial least squares (PLS), whereas root mean square error of prediction (RMSEP) was used as a fitness function for their selection. Three performance criteria, prediction accuracy, computational cost, and the number of selected descriptors, were used to evaluate the developed QSRR models. The results show that all five variable selection methods outperform interval PLS (iPLS), sparse PLS (sPLS), and the full PLS model, whereas GA is superior because of its lowest computational cost and higher accuracy (RMSEP of 5.534%) with a smaller number of variables (nine descriptors). The GA-QSRR model was validated initially through Y-randomization. In addition, it was successfully validated with an external testing set out of 102 peptides originating from Bacillus subtilis proteomes (RMSEP of 22.030%). Its applicability domain was defined, from which it was evident that the developed GA-QSRR exhibited strong robustness. All the sources of the model's error were identified, thus allowing for further application of the developed methodology in proteomics.

d'plus: A program to calculate accuracy and bias measures from detection and discrimination data.

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Macmillan, N A; Creelman, C D

1997-01-01

The program d'plus calculates accuracy (sensitivity) and response-bias parameters using Signal Detection Theory. Choice Theory, and 'nonparametric' models. is is appropriate for data from one-interval, two- and three-interval forced-choice, same different, ABX, and oddity experimental paradigms.

Levels of processing and the coding of position cues in motor short-term memory.

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Ho, L; Shea, J B

1978-06-01

The present study investigated the appropriateness of the levels-of-processing framework of memory for explaining retention of information in motor short-term memory. Subjects were given labels descriptive of the positions to be remembered by the experimenter (EL), were given no labels (NL), or provided their own labels (SL). A control group (CONT) was required to count backwards during the presentation of the criterion positions. The inclusion of a 30-sec filled retention interval as well as 0-sec and 30-sec unfilled retention intervals tested a prediction by Craik and Lockhart (1972), when attention is diverted from an item, information will be lost at a rate appropriate to its level of processing - that is, slower rates for deeper levels. Groups EL and SL had greater accuracy at recall for all three retention intervals than groups CONT and NL. In addition, there was no significant increase in error between 30-sec unfilled and 30-sec filled intervals for groups EL and SL, while there was a significant increase in error for groups CONT and NL. The data were interpreted in terms of Craik and Lockhart's (1972) levels-of-processing approach to memory.

Maximizing the retention level for proportional reinsurance under  -regulation of the finite time surplus process with unit-equalized interarrival time

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Sukanya Somprom

2016-07-01

Full Text Available The research focuses on an insurance model controlled by proportional reinsurance in the finite-time surplus process with a unit-equalized time interval. We prove the existence of the maximal retention level for independent and identically distributed claim processes under α-regulation, i.e., a model where the insurance company has to manage the probability of insolvency to be at most α. In addition, we illustrate the maximal retention level for exponential claims by applying the bisection technique.

Perioperative use of tamsulosin significantly decreases rates of urinary retention in men undergoing pelvic surgery.

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Poylin, Vitaliy; Curran, Thomas; Cataldo, Thomas; Nagle, Deborah

2015-09-01

Urinary retention is a common complication of pelvic surgery, leading to urinary tract infection and prolonged hospital stays. Tamsulosin is an alpha blocker that works by relaxing bladder neck muscles. It is used to treat benign prostatic hypertrophy and retention. We aim to investigate the potential benefits of preemptive tamsulosin use on rates of urinary retention in men undergoing pelvic surgery. This is a retrospective review of an institutional colorectal database. All men undergoing pelvic surgery between 2004 and 2013 were included. Patients given 0.4 mg of tamsulosin 3 days prior and after surgery at discretion of surgeon starting in 2007 were compared with patients receiving expectant postoperative management. One hundred eighty-five patients were included in the study (study group: N = 30; control group: N = 155). Study group patients were older (56.8 vs. 50.1 years). Overall urinary retention rate was 22% with significantly lower rates in the study group compared with control (6.7 vs. 25%; p = 0.029). Study group had higher rates of minimally invasive surgery (61 vs. 29.7%); however, this did not impact urinary retention rate (20.6 vs. 22.7% for minimally invasive surgery vs. open surgery; p = 0.85). Independent predictors of urinary retention included lack of preemptive tamsulosin (odds ratio (OR), 7.67; 95% confidence interval (CI), 1.4-41.7) and cancer location in the distal third of the rectum (OR, 18.8; 95% CI, 2.1-172.8). Preemptive perioperative use of tamsulosin may significantly decrease the incidence of urinary retention in men undergoing pelvic surgery. This may play a role in avoidance of urinary retention, particularly in patients with distal rectal cancer.

Improved Retention of Chest Compression Psychomotor Skills With Brief "Rolling Refresher" Training.

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Niles, Dana E; Nishisaki, Akira; Sutton, Robert M; Elci, Okan U; Meaney, Peter A; OʼConnor, Kathleen A; Leffelman, Jessica; Kramer-Johansen, Jo; Berg, Robert A; Nadkarni, Vinay

2017-08-01

High-quality cardiopulmonary resuscitation (CPR) is critical to improve survival from cardiac arrest. However, cardiopulmonary resuscitation knowledge and psychomotor skill proficiency are transient. We hypothesized that brief, in situ refresher training will improve chest compression (CC) psychomotor skill retention for bedside providers. Nurses completed a baseline skill evaluation of CC quality 6 months after traditional basic life support recertification. Data collected using ResusciAnne with SkillReporter included the following: CC depth, rate, complete release, and correct hand position. Total compliance was defined as 100% CC with depth of 50 mm or greater, rate of 100/min or greater, and more than 90% complete release. After the baseline evaluation, the subjects completed "Rolling Refresher" (RR) CC psychomotor training using audiovisual feedback every 2 to 3 months for 12 months until 30 seconds of CCs fulfilling total compliance criteria was achieved. Chest compression quality evaluations were repeated twice ("RR 6 month" and "RR 12 month" evaluation) after implementation of RR program. Thirty-seven providers enrolled and completed the baseline evaluation. Mean depth was 36.3 (9.7) mm, and 8% met criteria for depth, 35% for rate, and 5% for total compliance. After RRs were implemented, CC quality improved significantly at RR 6-month evaluation: odds ratio for meeting criteria were the following: depth of 35.1 (95% confidence interval = 2.5496, P = 0.009) and total compliance of 22.3 (95% confidence interval = 2.1239, P = 0.010). There was no difference in CC quality at RR 12-month versus RR 6-month evaluation. Retention of CC psychomotor skill quality is limited to 6 months after traditional basic life support recertification. Rolling Refresher CC training can significantly improve retention of CC psychomotor skills. Whether CC skills are improved, maintained, or deteriorate after 12 months of Refresher training and optimal frequency of Refreshers is

Urinary retention in women.

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Juma, Saad

2014-07-01

This review is a summary of the most pertinent published studies in the literature in the last 18 months that address cause, diagnosis, and management of urinary retention in women. Symptoms, uroflow, and pressure-flow studies have a low predictive value for and do not correlate with elevated postvoid residual urine (PVR). Anterior and posterior colporrhaphy do not cause de-novo bladder outlet obstruction in the majority of patients with elevated PVR, and the cause of elevated PVR may be other factors such as pain or anxiety causing abnormal relaxation of the pelvic floor and contributing to voiding difficulty. The risk of urinary retention in a future pregnancy after mid-urethral sling (MUS) is small. The risk of urinary tract infection and urinary retention after chemodenervation of the bladder with onabotulinumtoxin-A (100 IU) in patients with non-neurogenic urge incontinence is 33 and 5%, respectively. There is a lack of consensus among experts on the timing of sling takedown in the management of acute urinary retention following MUS procedures. There has been a significant progress in the understanding of the causation of urinary retention. Important areas that need further research (basic and clinical) are post-MUS and pelvic organ prolapse repair urinary retention and obstruction, and urinary retention owing to detrusor underactivity.

Procedural Documentation and Accuracy Assessment of Bathymetric Maps and Area/Capacity Tables for Small Reservoirs

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Wilson, Gary L.; Richards, Joseph M.

2006-01-01

Because of the increasing use and importance of lakes for water supply to communities, a repeatable and reliable procedure to determine lake bathymetry and capacity is needed. A method to determine the accuracy of the procedure will help ensure proper collection and use of the data and resulting products. It is important to clearly define the intended products and desired accuracy before conducting the bathymetric survey to ensure proper data collection. A survey-grade echo sounder and differential global positioning system receivers were used to collect water-depth and position data in December 2003 at Sugar Creek Lake near Moberly, Missouri. Data were collected along planned transects, with an additional set of quality-assurance data collected for use in accuracy computations. All collected data were imported into a geographic information system database. A bathymetric surface model, contour map, and area/capacity tables were created from the geographic information system database. An accuracy assessment was completed on the collected data, bathymetric surface model, area/capacity table, and contour map products. Using established vertical accuracy standards, the accuracy of the collected data, bathymetric surface model, and contour map product was 0.67 foot, 0.91 foot, and 1.51 feet at the 95 percent confidence level. By comparing results from different transect intervals with the quality-assurance transect data, it was determined that a transect interval of 1 percent of the longitudinal length of Sugar Creek Lake produced nearly as good results as 0.5 percent transect interval for the bathymetric surface model, area/capacity table, and contour map products.

An interpolated activity during the knowledge-of-results delay interval eliminates the learning advantages of self-controlled feedback schedules.

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Carter, Michael J; Ste-Marie, Diane M

2017-03-01

The learning advantages of self-controlled knowledge-of-results (KR) schedules compared to yoked schedules have been linked to the optimization of the informational value of the KR received for the enhancement of one's error-detection capabilities. This suggests that information-processing activities that occur after motor execution, but prior to receiving KR (i.e., the KR-delay interval) may underlie self-controlled KR learning advantages. The present experiment investigated whether self-controlled KR learning benefits would be eliminated if an interpolated activity was performed during the KR-delay interval. Participants practiced a waveform matching task that required two rapid elbow extension-flexion reversals in one of four groups using a factorial combination of choice (self-controlled, yoked) and KR-delay interval (empty, interpolated). The waveform had specific spatial and temporal constraints, and an overall movement time goal. The results indicated that the self-controlled + empty group had superior retention and transfer scores compared to all other groups. Moreover, the self-controlled + interpolated and yoked + interpolated groups did not differ significantly in retention and transfer; thus, the interpolated activity eliminated the typically found learning benefits of self-controlled KR. No significant differences were found between the two yoked groups. We suggest the interpolated activity interfered with information-processing activities specific to self-controlled KR conditions that occur during the KR-delay interval and that these activities are vital for reaping the associated learning benefits. These findings add to the growing evidence that challenge the motivational account of self-controlled KR learning advantages and instead highlights informational factors associated with the KR-delay interval as an important variable for motor learning under self-controlled KR schedules.

Achilles' ear? Inferior human short-term and recognition memory in the auditory modality.

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Bigelow, James; Poremba, Amy

2014-01-01

Studies of the memory capabilities of nonhuman primates have consistently revealed a relative weakness for auditory compared to visual or tactile stimuli: extensive training is required to learn auditory memory tasks, and subjects are only capable of retaining acoustic information for a brief period of time. Whether a parallel deficit exists in human auditory memory remains an outstanding question. In the current study, a short-term memory paradigm was used to test human subjects' retention of simple auditory, visual, and tactile stimuli that were carefully equated in terms of discriminability, stimulus exposure time, and temporal dynamics. Mean accuracy did not differ significantly among sensory modalities at very short retention intervals (1-4 s). However, at longer retention intervals (8-32 s), accuracy for auditory stimuli fell substantially below that observed for visual and tactile stimuli. In the interest of extending the ecological validity of these findings, a second experiment tested recognition memory for complex, naturalistic stimuli that would likely be encountered in everyday life. Subjects were able to identify all stimuli when retention was not required, however, recognition accuracy following a delay period was again inferior for auditory compared to visual and tactile stimuli. Thus, the outcomes of both experiments provide a human parallel to the pattern of results observed in nonhuman primates. The results are interpreted in light of neuropsychological data from nonhuman primates, which suggest a difference in the degree to which auditory, visual, and tactile memory are mediated by the perirhinal and entorhinal cortices.

A NOVEL APPROACH TO ARRHYTHMIA CLASSIFICATION USING RR INTERVAL AND TEAGER ENERGY

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CHANDRAKAR KAMATH

2012-12-01

Full Text Available It is hypothesized that a key characteristic of electrocardiogram (ECG signal is its nonlinear dynamic behaviour and that the nonlinear component changes more significantly between normal and arrhythmia conditions than the linear component. The usual statistical descriptors used in RR (R to R interval analysis do not capture the nonlinear disposition of RR interval variability. In this paper we explore a novel approach to extract the features from nonlinear component of the RR interval signal using Teager energy operator (TEO. The key feature of Teager energy is that it models the energy of the source that generated the signal rather than the energy of the signal itself. Hence any deviations in regular rhythmic activity of the heart get reflected in the Teager energy function. The classification evaluated on MIT-BIH database, with RR interval and mean of Teager energy computed over RR interval as features, exhibits an average accuracy that exceeds 99.79%.

The synaptic properties of cells define the hallmarks of interval timing in a recurrent neural network.

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Pérez, Oswaldo; Merchant, Hugo

2018-04-03

Extensive research has described two key features of interval timing. The bias property is associated with accuracy and implies that time is overestimated for short intervals and underestimated for long intervals. The scalar property is linked to precision and states that the variability of interval estimates increases as a function of interval duration. The neural mechanisms behind these properties are not well understood. Here we implemented a recurrent neural network that mimics a cortical ensemble and includes cells that show paired-pulse facilitation and slow inhibitory synaptic currents. The network produces interval selective responses and reproduces both bias and scalar properties when a Bayesian decoder reads its activity. Notably, the interval-selectivity, timing accuracy, and precision of the network showed complex changes as a function of the decay time constants of the modeled synaptic properties and the level of background activity of the cells. These findings suggest that physiological values of the time constants for paired-pulse facilitation and GABAb, as well as the internal state of the network, determine the bias and scalar properties of interval timing. Significant Statement Timing is a fundamental element of complex behavior, including music and language. Temporal processing in a wide variety of contexts shows two primary features: time estimates exhibit a shift towards the mean (the bias property) and are more variable for longer intervals (the scalar property). We implemented a recurrent neural network that includes long-lasting synaptic currents, which can not only produce interval selective responses but also follow the bias and scalar properties. Interestingly, only physiological values of the time constants for paired-pulse facilitation and GABAb, as well as intermediate background activity within the network can reproduce the two key features of interval timing. Copyright © 2018 the authors.

Postoperative Urinary Retention and Urinary Tract Infections Predict Midurethral Sling Mesh Complications.

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Punjani, Nahid; Winick-Ng, Jennifer; Welk, Blayne

2017-01-01

To determine if postoperative urinary retention and urinary tract infections (UTIs) were predictors of future mesh complications requiring surgical intervention after midurethral sling (MUS). Administrative data in Ontario, Canada, between 2002 and 2013 were used to identify all women who underwent a mesh-based MUS. The primary outcome was revision of the transvaginal mesh sling (including mesh removal/erosion/fistula, or urethrolysis). Two potential risk factors were analyzed: postoperative retention (within 30 days of procedure) and number of postoperative emergency room visits or hospital admissions for UTI symptoms. A total of 59,556 women had a MUS, of which 1598 (2.7%) required revision surgery. Of the 2025 women who presented to the emergency room or were admitted to hospital for postoperative retention, 212 (10.5%) required operative mesh revision. Of the 11,747 patients who had at least one postoperative UTI, 366 (3.1%) patients required operative mesh revision. In adjusted analysis, postoperative retention was significantly predictive of future reoperation (hazard ratio [HR] 3.46, 95% confidence interval [CI] 2.97-4.02), and this difference persisted when urethrolysis was excluded as a reason for sling revision (HR 3.08, 95% CI 2.62-3.63). Similarly, in adjusted analysis, each additional postoperative hospital visit for UTI symptoms increased the risk for surgical intervention for mesh complications (HR 1.74, 95% CI 1.61-1.87). Postoperative urinary retention and hospital presentation for UTI symptoms are associated with an increased risk of reoperation for MUS complications. These patients should be followed and investigated for mesh complications when appropriate. Copyright © 2016 Elsevier Inc. All rights reserved.

The Effect of Pixel Size on the Accuracy of Orthophoto Production

Science.gov (United States)

Kulur, S.; Yildiz, F.; Selcuk, O.; Yildiz, M. A.

2016-06-01

In our country, orthophoto products are used by the public and private sectors for engineering services and infrastructure projects, Orthophotos are particularly preferred due to faster and are more economical production according to vector digital photogrammetric production. Today, digital orthophotos provide an expected accuracy for engineering and infrastructure projects. In this study, the accuracy of orthophotos using pixel sizes with different sampling intervals are tested for the expectations of engineering and infrastructure projects.

Retention in HIV Care During Pregnancy and the Postpartum Period in the Option B+ Era: Systematic Review and Meta-Analysis of Studies in Africa.

Science.gov (United States)

Knettel, Brandon A; Cichowitz, Cody; Ngocho, James Samwel; Knippler, Elizabeth T; Chumba, Lilian N; Mmbaga, Blandina T; Watt, Melissa H

2018-04-15

Under Option B+ guidelines for prevention of mother-to-child transmission of HIV, pregnant and breastfeeding women initiate antiretroviral therapy for lifelong use. The objectives of this study were: (1) to synthesize data on retention in care over time in option B+ programs in Africa, and (2) to identify factors associated with retention in care. PubMed, EMBASE, and African Index Medicus were systematically searched from January 2012 to June 2017. Pooled estimates of the proportion of women retained were generated and factors associated with retention were analyzed thematically. Thirty-five articles were included in the final review; 22 reported retention rates (n = 60,890) and 25 reported factors associated with retention. Pooled estimates of retention were 72.9% (95% confidence interval: 66.4% to 78.9%) at 6 months for studies reporting option B+ were below those of the general adult population, necessitating interventions targeting the complex circumstances of women initiating care under option B+. Improved and standardized procedures to track and report retention are needed to accurately represent care engagement and capture undocumented transfers within the health system.

Inferring uncertainty from interval estimates: Effects of alpha level and numeracy

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Luke F. Rinne

2013-05-01

Full Text Available Interval estimates are commonly used to descriptively communicate the degree of uncertainty in numerical values. Conventionally, low alpha levels (e.g., .05 ensure a high probability of capturing the target value between interval endpoints. Here, we test whether alpha levels and individual differences in numeracy influence distributional inferences. In the reported experiment, participants received prediction intervals for fictitious towns' annual rainfall totals (assuming approximately normal distributions. Then, participants estimated probabilities that future totals would be captured within varying margins about the mean, indicating the approximate shapes of their inferred probability distributions. Results showed that low alpha levels (vs. moderate levels; e.g., .25 more frequently led to inferences of over-dispersed approximately normal distributions or approximately uniform distributions, reducing estimate accuracy. Highly numerate participants made more accurate estimates overall, but were more prone to inferring approximately uniform distributions. These findings have important implications for presenting interval estimates to various audiences.

Assessment of the thematic accuracy of land cover maps

DEFF Research Database (Denmark)

Høhle, Joachim

2015-01-01

were applied (‘Decision Tree’ and ‘Support Vector Machine’) using only two attributes (height above ground and normalized difference vegetation index) which both are derived from the images. The assessment of the thematic accuracy applied a stratified design and was based on accuracy measures...... methods perform equally for five classes. Trees are classified with a much better accuracy and a smaller confidence interval by means of the decision tree method. Buildings are classified by both methods with an accuracy of 99% (95% CI: 95%-100%) using independent 3D checkpoints. The average width......Several land cover maps are generated from aerial imagery and assessed by different approaches. The test site is an urban area in Europe for which six classes (‘building’, ‘hedge and bush’, ‘grass’, ‘road and parking lot’, ‘tree’, ‘wall and car port’) had to be derived. Two classification methods...

Impacts of Return-to-Work Type and Period on Job Retention in Workers with Occupational Injuries and Diseases.

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Jeong, Inchul; Park, Jae Bum; Kim, Hyoung Ryoul; Yoon, Jin Ha; Won, Jong Uk; Roh, Jaehoon

2018-01-01

Despite the necessity of job retention in achieving return-to-work (RTW) goals, many workers leave their jobs after returning to work. The objective of this study was to examine the impacts of RTW type and period on job retention in Korean workers with occupational injuries and diseases. Data were derived from the Panel Study of Worker's Compensation Insurance, including data from 2,000 systemically sampled workers who had finished recuperation in 2012; three waves of survey data were included in the analyses. Workers who returned to work (n = 1,610) were included in the analysis of the relationship between RTW type and job retention, and 664 workers who returned to their original workplaces were included in the analysis of the relationship between RTW period and job retention. The participants completed a questionnaire, and administrative data were provided by workers' compensation insurance. A Cox proportional-hazards regression analysis showed an increased hazard ratio (HR) for non-retention of 2.66 (95% confidence interval, 2.11-3.35) in reemployed workers compared to that in workers returning to their original workplaces. Among workers returning to their original workplaces, HRs for non-retention were increased in workers with a RTW period of 13-24 months (3.03 [1.52-6.04]) and > 24 months (5.33 [2.14-13.25]) compared to workers with a RTW period of ≤ 3 months. RTW type and period were significantly related to job retention, suggesting that policies for promoting job retention rate should be implemented. © 2018 The Korean Academy of Medical Sciences.

Pharmacological evidence that a failure to recruit NMDA receptors contributes to impaired fear extinction retention in adolescent rats.

Science.gov (United States)

Baker, Kathryn D; Richardson, Rick

2017-09-01

Adolescents, both humans and rodents, exhibit a marked impairment in extinction of fear relative to younger and older groups which could be caused by a failure to efficiently recruit NMDA receptors (NMDARs) in adolescence. It is well-established that systemic administration of NMDAR antagonists (e.g., MK801) before extinction training impairs the retention of extinction in adult and juvenile rodents, but it is unknown whether this is also the case for adolescents. Therefore, in the present study we investigated the effect of pharmacologically manipulating the NMDAR on extinction retention in adolescent rats. When extinction retention is typically impaired (i.e., after one session of extinction training) adolescent male rats given d-cycloserine (a partial NMDAR agonist) showed enhanced extinction retention relative to saline-treated animals while animals given MK801 (a non-competitive antagonist) did not exhibit any further impairment of extinction retention relative to the controls. In a further two experiments we demonstrated that when two sessions of extinction training separated by either 4 or 24h intervals were given to adolescent rats, saline-treated animals exhibited good extinction retention and the animals given MK801 before the second session exhibited impaired extinction retention. These findings suggest that extinction in adolescence does not initially involve NMDARs and this is a likely mechanism that contributes to the impaired fear inhibition observed at this age. However, NMDARs appear to be recruited with extended extinction training or after administration of a partial agonist, both of which lead to effective extinction retention. Copyright © 2016 Elsevier Inc. All rights reserved.

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

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Assefa, Yibeltal; Worku, Alemayehu; Wouters, Edwin; Koole, Olivier; Haile Mariam, Damen; Van Damme, Wim

2012-01-01

Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

Directory of Open Access Journals (Sweden)

Yibeltal Assefa

Full Text Available INTRODUCTION: Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. METHODS: Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. RESULTS: We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. CONCLUSION: The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

A New Uncertain Analysis Method for the Prediction of Acoustic Field with Random and Interval Parameters

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Mingjie Wang

2016-01-01

Full Text Available For the frequency response analysis of acoustic field with random and interval parameters, a nonintrusive uncertain analysis method named Polynomial Chaos Response Surface (PCRS method is proposed. In the proposed method, the polynomial chaos expansion method is employed to deal with the random parameters, and the response surface method is used to handle the interval parameters. The PCRS method does not require efforts to modify model equations due to its nonintrusive characteristic. By means of the PCRS combined with the existing interval analysis method, the lower and upper bounds of expectation, variance, and probability density function of the frequency response can be efficiently evaluated. Two numerical examples are conducted to validate the accuracy and efficiency of the approach. The results show that the PCRS method is more efficient compared to the direct Monte Carlo simulation (MCS method based on the original numerical model without causing significant loss of accuracy.

Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

International Nuclear Information System (INIS)

Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

2010-01-01

Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had 125 I and 638 patients had 103 Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline α-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm 3 , 25-45 cm 3 , 3 ; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline α-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

The role of radiation damage on retention and temperature intervals of helium and hydrogen detrapping in structural materials

Energy Technology Data Exchange (ETDEWEB)

Tolstolutskaya, G.D., E-mail: g.d.t@kipt.kharkov.ua [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., 61108 Kharkov (Ukraine); Ruzhytskyi, V.V.; Voyevodin, V.N.; Kopanets, I.E.; Karpov, S.A.; Nikitin, A.V. [National Science Center “Kharkov Institute of Physics and Technology”, 1, Akademicheskaya St., 61108 Kharkov (Ukraine)

2013-11-15

An experimental study of hydrogen/deuterium behavior in ferritic–martensitic stainless steels EP-450 (Cr13Mo2NbVB), EP-852 (Cr13Mo2VS), and RUSFER-EK-181 (Fe12Cr2WVTaB) is presented. The effect of displacement damage (dpa) resulting from irradiation with helium, hydrogen, and argon ions on features of deuterium detrapping and retention in steels was studied using ion implantation, nuclear reaction depth profiling, and thermal desorption spectrometry techniques. Numerical simulation on the basis of the continuum rate theory was applied for obtaining thermodynamic parameters of deuterium trapping and desorption in steels.

Effects of Impression Coping Design, Impression Technique, and Dental Undercuts on the Accuracy of Implant Impressions Assessed by 3-Dimensional Optical Scanning: An In Vitro Study.

Science.gov (United States)

Sabouhi, Mahmoud; Bajoghli, Farshad; Dakhilalian, Mansour; Beygi, Ali; Abolhasani, Majid

2016-04-01

The aim of this in vitro study was to evaluate the effect of the type and design of the impression copings on the accuracy of implant impressions in 2 different conditions. A reference model with 2 implants inserted in bilateral mandibular canines was fabricated. The posterior teeth were inserted as tilted to simulate intra-oral undercuts. The teeth were eliminated to create an edentulous condition. Three different impression techniques were performed (open high retentive [OH], open low retentive [OL], closed [C]) for each condition. Total of 48 casts were made. Two scan-bodies were secured on each cast, scanned by an optical scanner. Then, they were compared to the scan of the reference model, and the calculated mean errors were analyzed with a 2-way ANOVA and Tukey test. There was no significant difference between the complete and partially edentulous groups (F = 3.252, P = 0.079). There was significant difference between the different designs of the impression copings (F = 31.789, P impression copings was more important than the undercuts. The accuracy of the closed tray coping was greater than the low retentive coping and equal to the high retentive coping.

Accuracy of repeated kidney size estimation by ultrasonography and urography in children

International Nuclear Information System (INIS)

Hederstroem, E.; Forsberg, L.

1985-01-01

The accuracy of repeated sonographic and urographic kidney length measurements in kidney size evaluation was investigated in 80 children 0 to 14 years of age, mean age 4.5 years. At sonography 250 kidney lengths were compared. A difference of 0 to 1.0 cm in repeated length measurement was considered to be good accuracy and 94 per cent of right and 96 per cent of left kidney length were found within this interval-a better result than for urography with 76 per cent of repeated right kidney and 79 per cent of kidney lengths within the same interval (94 lengths). Both methods display a variation of kidney lengths which may lead to under- and overestimation of kidney size and growth. The investigation thus indicates good accuracy for repeated sonographic kidney size assessment which should be repeated often enough to estabilish a growth chart displaying the trend rather than rely too much on single measurements. Sonography can be highly recommended as a convenient and harmless alternative to urography. (orig.)

Retention of knowledge and skills in pediatric basic life support amongst pediatricians.

Science.gov (United States)

Binkhorst, Mathijs; Coopmans, Michelle; Draaisma, Jos M T; Bot, Petra; Hogeveen, Marije

2018-05-07

Retention of resuscitation skills is usually assessed at a predefined moment, which enables participants to prepare themselves, possibly introducing bias. In this multicenter study, we evaluated the retention of knowledge and skills in pediatric basic life support (PBLS) amongst 58 pediatricians and pediatric residents with an unannounced examination. Practical PBLS skills were assessed with a validated scoring instrument, theoretical knowledge with a 10-item multiple-choice test (MCQ). Participants self-assessed their PBLS capabilities using five-point Likert scales. Background data were collected with a questionnaire. Of our participants, 21% passed the practical PBLS exam: 29% failed on compressions/ventilations, 31% on other parts of the algorithm, 19% on both. Sixty-nine percent passed the theoretical test. Participants who more recently completed a PBLS course performed significantly better on the MCQ (p = 0.03). This association was less clear-cut for performance on the practical exam (p = 0.11). Older, attending pediatricians with more years of experience in pediatrics performed less well than their younger colleagues (p basic life support (PBLS) in daily practice. Poor retention of skills supposedly accounts for this incompetence. Without regular exposure, resuscitation skills usually deteriorate within 3 to 6 months after training. • Examination of resuscitation skills usually takes place after training. Also, in most studies evaluating retention of skills, participants are tested at a predefined moment. Inasmuch as participants are able to prepare themselves, these assessments do not reflect the ad hoc resuscitation capabilities of pediatricians and residents. What is New: • In this study, pediatricians and pediatric residents had to complete an unannounced PBLS exam at variable time intervals from last certification. Retention of PBLS skills was rather poor (pass rate 21%). • The PBLS skills of older, attending pediatricians with many

A model of interval timing by neural integration.

Science.gov (United States)

Simen, Patrick; Balci, Fuat; de Souza, Laura; Cohen, Jonathan D; Holmes, Philip

2011-06-22

We show that simple assumptions about neural processing lead to a model of interval timing as a temporal integration process, in which a noisy firing-rate representation of time rises linearly on average toward a response threshold over the course of an interval. Our assumptions include: that neural spike trains are approximately independent Poisson processes, that correlations among them can be largely cancelled by balancing excitation and inhibition, that neural populations can act as integrators, and that the objective of timed behavior is maximal accuracy and minimal variance. The model accounts for a variety of physiological and behavioral findings in rodents, monkeys, and humans, including ramping firing rates between the onset of reward-predicting cues and the receipt of delayed rewards, and universally scale-invariant response time distributions in interval timing tasks. It furthermore makes specific, well-supported predictions about the skewness of these distributions, a feature of timing data that is usually ignored. The model also incorporates a rapid (potentially one-shot) duration-learning procedure. Human behavioral data support the learning rule's predictions regarding learning speed in sequences of timed responses. These results suggest that simple, integration-based models should play as prominent a role in interval timing theory as they do in theories of perceptual decision making, and that a common neural mechanism may underlie both types of behavior.

Multiresolution Wavelet Analysis of Heartbeat Intervals Discriminates Healthy Patients from Those with Cardiac Pathology

Science.gov (United States)

Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

1998-02-01

We applied multiresolution wavelet analysis to the sequence of times between human heartbeats ( R-R intervals) and have found a scale window, between 16 and 32 heartbeat intervals, over which the widths of the R-R wavelet coefficients fall into disjoint sets for normal and heart-failure patients. This has enabled us to correctly classify every patient in a standard data set as belonging either to the heart-failure or normal group with 100% accuracy, thereby providing a clinically significant measure of the presence of heart failure from the R-R intervals alone. Comparison is made with previous approaches, which have provided only statistically significant measures.

Method of high precision interval measurement in pulse laser ranging system

Science.gov (United States)

Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

2013-09-01

Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

Calculation of solar irradiation prediction intervals combining volatility and kernel density estimates

International Nuclear Information System (INIS)

Trapero, Juan R.

2016-01-01

In order to integrate solar energy into the grid it is important to predict the solar radiation accurately, where forecast errors can lead to significant costs. Recently, the increasing statistical approaches that cope with this problem is yielding a prolific literature. In general terms, the main research discussion is centred on selecting the “best” forecasting technique in accuracy terms. However, the need of the users of such forecasts require, apart from point forecasts, information about the variability of such forecast to compute prediction intervals. In this work, we will analyze kernel density estimation approaches, volatility forecasting models and combination of both of them in order to improve the prediction intervals performance. The results show that an optimal combination in terms of prediction interval statistical tests can achieve the desired confidence level with a lower average interval width. Data from a facility located in Spain are used to illustrate our methodology. - Highlights: • This work explores uncertainty forecasting models to build prediction intervals. • Kernel density estimators, exponential smoothing and GARCH models are compared. • An optimal combination of methods provides the best results. • A good compromise between coverage and average interval width is shown.

Everyday Attention and Lecture Retention: The Effects of Time, Fidgeting, and Mind Wandering

Directory of Open Access Journals (Sweden)

James eFarley

2013-09-01

Full Text Available We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behaviour. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-minute lecture video, and at regular 5 minute intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behaviour was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual’s attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention.

A standardized method for the calibration of thermodynamic data for the prediction of gas chromatographic retention times.

Science.gov (United States)

McGinitie, Teague M; Ebrahimi-Najafabadi, Heshmatollah; Harynuk, James J

2014-02-21

A new method for calibrating thermodynamic data to be used in the prediction of analyte retention times is presented. The method allows thermodynamic data collected on one column to be used in making predictions across columns of the same stationary phase but with varying geometries. This calibration is essential as slight variances in the column inner diameter and stationary phase film thickness between columns or as a column ages will adversely affect the accuracy of predictions. The calibration technique uses a Grob standard mixture along with a Nelder-Mead simplex algorithm and a previously developed model of GC retention times based on a three-parameter thermodynamic model to estimate both inner diameter and stationary phase film thickness. The calibration method is highly successful with the predicted retention times for a set of alkanes, ketones and alcohols having an average error of 1.6s across three columns. Copyright © 2014 Elsevier B.V. All rights reserved.

Testing the shape-similarity hypothesis between particle-size distribution and water retention for Sicilian soils

Directory of Open Access Journals (Sweden)

Chiara Antinoro

2012-12-01

Full Text Available Application of the Arya and Paris (AP model to estimate the soil water retention curve requires a detailed description of the particlesize distribution (PSD but limited experimental PSD data are generally determined by the conventional sieve-hydrometer (SH method. Detailed PSDs can be obtained by fitting a continuous model to SH data or performing measurements by the laser diffraction (LD method. The AP model was applied to 40 Sicilian soils for which the PSD was measured by both the SH and LD methods. The scale factor was set equal to 1.38 (procedure AP1 or estimated by a logistical model with parameters gathered from literature (procedure AP2. For both SH and LD data, procedure AP2 allowed a more accurate prediction of the water retention than procedure AP1, confirming that it is not convenient to use a unique value of  for soils that are very different in texture. Despite the differences in PSDs obtained by the SH and LD methods, the water retention predicted by a given procedure (AP1 or AP2 using SH or LD data was characterized by the same level of accuracy. Discrepancies in the estimated water retention from the two PSD measurement methods were attributed to underestimation of the finest diameter frequency obtained by the LD method. Analysis also showed that the soil water retention estimated using the SH method was affected by an estimation bias that could be corrected by an optimization procedure (OPT. Comparison of a-distributions and water retention shape indices obtained by the two methods (SH or LD indicated that the shape-similarity hypothesis is better verified if the traditional sieve-hydrometer data are used to apply the AP model. The optimization procedure allowed more accurate predictions of the water retention curves than the traditional AP1 and AP2 procedures. Therefore, OPT can be considered a valid alternative to the more complex logistical model for estimating the water retention curve of Sicilian soils.

Urinary Retention Associated with Stroke.

Science.gov (United States)

Umemura, Takeru; Ohta, Hirotsugu; Yokota, Akira; Yarimizu, Shiroh; Nishizawa, Shigeru

Patients often exhibit urinary retention following a stroke. Various neuropathological and animal studies have implicated the medulla oblongata, pons, limbic system, frontal lobe as areas responsible for micturition control, although the exact area responsible for urinary retention after stroke is not clear. The purpose of this study was to identify the stroke area responsible for urinary retention by localizing the areas where strokes occur. We assessed 110 patients with cerebral infarction and 27 patients with cerebral hemorrhage (78 men, 59 women; mean age, 73.0 years) who had been admitted to our hospital between October, 2012 and September, 2013. We used computed tomography (CT) and magnetic resonance imaging (MRI) to investigate the stroke location, and evaluated whether post-stroke urinary retention occurred. Twelve (8.8%) of the 137 patients (7 men, 5 women; mean age, 78.8 years) exhibited urinary retention after a stroke. Stroke occurred in the right/left dominant hemisphere in 7 patients; nondominant hemisphere in 1; cerebellum in 3; and brainstem in 1. Strokes in the dominant hemisphere were associated with urinary retention (P = 0.0314), particularly in the area of the insula (P < 0.01). We concluded that stroke affecting the insula of the dominant hemisphere tends to cause urinary retention.

Achilles' ear? Inferior human short-term and recognition memory in the auditory modality.

Directory of Open Access Journals (Sweden)

James Bigelow

Full Text Available Studies of the memory capabilities of nonhuman primates have consistently revealed a relative weakness for auditory compared to visual or tactile stimuli: extensive training is required to learn auditory memory tasks, and subjects are only capable of retaining acoustic information for a brief period of time. Whether a parallel deficit exists in human auditory memory remains an outstanding question. In the current study, a short-term memory paradigm was used to test human subjects' retention of simple auditory, visual, and tactile stimuli that were carefully equated in terms of discriminability, stimulus exposure time, and temporal dynamics. Mean accuracy did not differ significantly among sensory modalities at very short retention intervals (1-4 s. However, at longer retention intervals (8-32 s, accuracy for auditory stimuli fell substantially below that observed for visual and tactile stimuli. In the interest of extending the ecological validity of these findings, a second experiment tested recognition memory for complex, naturalistic stimuli that would likely be encountered in everyday life. Subjects were able to identify all stimuli when retention was not required, however, recognition accuracy following a delay period was again inferior for auditory compared to visual and tactile stimuli. Thus, the outcomes of both experiments provide a human parallel to the pattern of results observed in nonhuman primates. The results are interpreted in light of neuropsychological data from nonhuman primates, which suggest a difference in the degree to which auditory, visual, and tactile memory are mediated by the perirhinal and entorhinal cortices.

Achilles’ Ear? Inferior Human Short-Term and Recognition Memory in the Auditory Modality

Science.gov (United States)

Bigelow, James; Poremba, Amy

2014-01-01

Studies of the memory capabilities of nonhuman primates have consistently revealed a relative weakness for auditory compared to visual or tactile stimuli: extensive training is required to learn auditory memory tasks, and subjects are only capable of retaining acoustic information for a brief period of time. Whether a parallel deficit exists in human auditory memory remains an outstanding question. In the current study, a short-term memory paradigm was used to test human subjects’ retention of simple auditory, visual, and tactile stimuli that were carefully equated in terms of discriminability, stimulus exposure time, and temporal dynamics. Mean accuracy did not differ significantly among sensory modalities at very short retention intervals (1–4 s). However, at longer retention intervals (8–32 s), accuracy for auditory stimuli fell substantially below that observed for visual and tactile stimuli. In the interest of extending the ecological validity of these findings, a second experiment tested recognition memory for complex, naturalistic stimuli that would likely be encountered in everyday life. Subjects were able to identify all stimuli when retention was not required, however, recognition accuracy following a delay period was again inferior for auditory compared to visual and tactile stimuli. Thus, the outcomes of both experiments provide a human parallel to the pattern of results observed in nonhuman primates. The results are interpreted in light of neuropsychological data from nonhuman primates, which suggest a difference in the degree to which auditory, visual, and tactile memory are mediated by the perirhinal and entorhinal cortices. PMID:24587119

Similarity of Students' Experiences and Accuracy of Faculty and Staff Perceptions: Issues for Student Retention.

Science.gov (United States)

Heinemann, Allen W.; And Others

Research on attrition of university students has recently examined "dropping out" as the culmination of a complex interactive process. In order to examine differences between successful students (persisters) and students who officially withdrew from a major university, and to examine the accuracy of faculty and staff perceptions of students'…

Evaluation of locally established reference intervals for hematology and biochemistry parameters in Western Kenya.

Science.gov (United States)

Odhiambo, Collins; Oyaro, Boaz; Odipo, Richard; Otieno, Fredrick; Alemnji, George; Williamson, John; Zeh, Clement

2015-01-01

Important differences have been demonstrated in laboratory parameters from healthy persons in different geographical regions and populations, mostly driven by a combination of genetic, demographic, nutritional, and environmental factors. Despite this, European and North American derived laboratory reference intervals are used in African countries for patient management, clinical trial eligibility, and toxicity determination; which can result in misclassification of healthy persons as having laboratory abnormalities. An observational prospective cohort study known as the Kisumu Incidence Cohort Study (KICoS) was conducted to estimate the incidence of HIV seroconversion and identify determinants of successful recruitment and retention in preparation for an HIV vaccine/prevention trial among young adults and adolescents in western Kenya. Laboratory values generated from the KICoS were compared to published region-specific reference intervals and the 2004 NIH DAIDS toxicity tables used for the trial. About 1106 participants were screened for the KICoS between January 2007 and June 2010. Nine hundred and fifty-three participants aged 16 to 34 years, HIV-seronegative, clinically healthy, and non-pregnant were selected for this analysis. Median and 95% reference intervals were calculated for hematological and biochemistry parameters. When compared with both published region-specific reference values and the 2004 NIH DAIDS toxicity table, it was shown that the use of locally established reference intervals would have resulted in fewer participants classified as having abnormal hematological or biochemistry values compared to US derived reference intervals from DAIDS (10% classified as abnormal by local parameters vs. >40% by US DAIDS). Blood urea nitrogen was most often out of range if US based intervals were used: 83% by US based reference intervals. Differences in reference intervals for hematological and biochemical parameters between western and African populations

Does skill retention benefit from retentivity and symbolic rehearsal? - two studies with a simulated process control task.

Science.gov (United States)

Kluge, Annette; Frank, Barbara; Maafi, Sanaz; Kuzmanovska, Aleksandra

2016-05-01

Two experiments were designed to compare two symbolic rehearsal refresher interventions (imaginary practice, a hidden introspective process) and investigate the role of retentivity in skill retention. Retentivity is investigated as the ability to memorise and reproduce information and associations that were learned a short time ago. Both experiments comprised initial training (week 1), a symbolic rehearsal for the experimental group (week 2) and a retention assessment (week 3). In the first study, the experimental group received a symbolic rehearsal, while the control group received no rehearsal. In the second study, the experimental group received the same symbolic rehearsal used in study 1, enhanced with rehearsal tasks addressing human-computer interaction. The results showed that both symbolic rehearsal interventions were equally likely to mitigate skill decay. The retentivity showed medium to high correlations with skill retention in both studies, and the results suggest that subjects high in retentivity benefit more from a symbolic rehearsal refresher intervention. Practitioner Summary: Skill decay becomes a problem in situations in which jobs require the correct mastery of non-routine situations. Two experimental studies with simulated process control tasks showed that symbolic rehearsal and retentivity can significantly mitigate skill decay and that subjects higher in retentivity benefit more from refresher interventions.

Modelling accuracy and variability of motor timing in treated and untreated Parkinson’s disease and healthy controls

Directory of Open Access Journals (Sweden)

Catherine Rhian Gwyn Jones

2011-12-01

Full Text Available Parkinson’s disease (PD is characterised by difficulty with the timing of movements. Data collected using the synchronization-continuation paradigm, an established motor timing paradigm, have produced varying results but with most studies finding impairment. Some of this inconsistency comes from variation in the medication state tested, in the inter-stimulus intervals (ISI selected, and in changeable focus on either the synchronization (tapping in time with a tone or continuation (maintaining the rhythm in the absence of the tone phase. We sought to re-visit the paradigm by testing across four groups of participants: healthy controls, medication naïve de novo PD patients, and treated PD patients both ‘on’ and ‘off’ dopaminergic medication. Four finger tapping intervals (ISI were used: 250ms, 500ms, 1000ms and 2000ms. Categorical predictors (group, ISI, and phase were used to predict accuracy and variability using a linear mixed model. Accuracy was defined as the relative error of a tap, and variability as the deviation of the participant’s tap from group predicted relative error. Our primary finding is that the treated PD group (PD patients ‘on’ and ‘off’ dopaminergic therapy showed a significantly different pattern of accuracy compared to the de novo group and the healthy controls at the 250ms interval. At this interval, the treated PD patients performed ‘ahead’ of the beat whilst the other groups performed ‘behind’ the beat. We speculate that this ‘hastening’ relates to the clinical phenomenon of motor festination. Across all groups, variability was smallest for both phases at the 500 ms interval, suggesting an innate preference for finger tapping within this range. Tapping variability for the two phases became increasingly divergent at the longer intervals, with worse performance in the continuation phase. The data suggest that patients with PD can be best discriminated from healthy controls on measures of

Efficient Work Team Scheduling: Using Psychological Models of Knowledge Retention to Improve Code Writing Efficiency

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Michael J. Pelosi

2014-12-01

Full Text Available Development teams and programmers must retain critical information about their work during work intervals and gaps in order to improve future performance when work resumes. Despite time lapses, project managers want to maximize coding efficiency and effectiveness. By developing a mathematically justified, practically useful, and computationally tractable quantitative and cognitive model of learning and memory retention, this study establishes calculations designed to maximize scheduling payoff and optimize developer efficiency and effectiveness.

A Dynamic Interval-Valued Intuitionistic Fuzzy Sets Applied to Pattern Recognition

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Zhenhua Zhang

2013-01-01

Full Text Available We present dynamic interval-valued intuitionistic fuzzy sets (DIVIFS, which can improve the recognition accuracy when they are applied to pattern recognition. By analyzing the degree of hesitancy, we propose some DIVIFS models from intuitionistic fuzzy sets (IFS and interval-valued IFS (IVIFS. And then we present a novel ranking condition on the distance of IFS and IVIFS and introduce some distance measures of DIVIFS satisfying the ranking condition. Finally, a pattern recognition example applied to medical diagnosis decision making is given to demonstrate the application of DIVIFS and its distances. The simulation results show that the DIVIFS method is more comprehensive and flexible than the IFS method and the IVIFS method.

NONLINEAR ASSIGNMENT-BASED METHODS FOR INTERVAL-VALUED INTUITIONISTIC FUZZY MULTI-CRITERIA DECISION ANALYSIS WITH INCOMPLETE PREFERENCE INFORMATION

OpenAIRE

TING-YU CHEN

2012-01-01

In the context of interval-valued intuitionistic fuzzy sets, this paper develops nonlinear assignment-based methods to manage imprecise and uncertain subjective ratings under incomplete preference structures and thereby determines the optimal ranking order of the alternatives for multiple criteria decision analysis. By comparing each interval-valued intuitionistic fuzzy number's score function, accuracy function, membership uncertainty index, and hesitation uncertainty index, a ranking proced...

Assessment of the delivery retention and distribution of a mucoadhesive vaginal mousse formulation

International Nuclear Information System (INIS)

Penglis, S.; Chatterton, B.; Kovacs, J.; Hunt, B.

2002-01-01

Full text: Local treatment is used for a number of vaginal conditions (eg candidiasis). Traditional vaginal delivery systems such as creams and foams may have limited residence time and uneven distribution within the vagina. Eight pre-menopausal women, mean age 27 were studied in a random crossover study with either commercially available vaginal cream or the test formulation, an aerosol mousse developed to provide a prolonged residence time and better distribution of vaginally applied medication. Both were labelled with 4MBq of 99m Tc DTPA. Following administration, distribution and retention were followed using a dual head gamma camera at short intervals for up to 7 hours with a delayed image at 24 hours. The vaginal image was divided into four quadrants and an external region, and geometric mean counts were calculated as an index of retention. External losses were collected on sanitary napkins, which were changed after each image acquisition. Despite the use of sanitary pads, by 24 hours 40% of the administered activity was not accounted for and this was probably lost during urination. There was no significant difference between the measured retention and distribution of the products. Scintigraphic techniques are useful in assessing the dynamics of local vaginal therapies. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

Military Retention. A Comparative Outlook

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Vasile Sminchise

2016-06-01

Full Text Available One of the main goals for human resources management structures and for armed forces leaders is to maintain all necessary personnel, both qualitatively and quantitatively for operational needs or for full required capabilities. The retention of military personnel is essential to keep morale and unit readiness and to reduce the costs for recruiting, training, replacement of manpower. Retention rates depend not only on money or other social measures. The goal for retention is to keep in use the most valuable resource that belongs to an organization: the human beings and their knowledge. The aim pf this paper is to provide a comparative analysis of retention measures in various countries based on Research and Technology Organisation report released in 2007 and, thus, provide more examples of retention measures as far as the Romanian military system is concerned.

Retention of Root Canal Posts

DEFF Research Database (Denmark)

Sahafi, A; Benetti, Ana Raquel; Flury, S

2015-01-01

The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement......, pretreatment with tribochemical silicate coating significantly increased retention of the posts. Increased cement film thickness resulted in decreased retention of untreated posts and of pretreated posts luted with zinc phosphate cement. Increased cement film thickness had no influence on retention...

Higher retention and viral suppression with adolescent-focused HIV clinic in South Africa.

Directory of Open Access Journals (Sweden)

Brian C Zanoni

Full Text Available To determine retention in care and virologic suppression among HIV-infected adolescents and young adults attending an adolescent-friendly clinic compared to those attending the standard pediatric clinic at the same site.Retrospective cohort analysis.Government supported, hospital-based antiretroviral clinic in KwaZulu-Natal, South Africa.Two hundred forty-one perinatally HIV-infected adolescents and young adults aged 13 to 24 years attending an adolescent-friendly clinic or the standard pediatric clinic from April 2007 to November 2015.Attendance in an adolescent-friendly clinic compared to a standard pediatric clinic.Retention in care defined as one clinic visit or pharmacy refill in the prior 6 months; HIV-1 viral suppression defined as < 400 copies/ml.Overall, among 241 adolescents and young adults, retention was 89% (214/241 and viral suppression was 81% (196/241. Retention was higher among those attending adolescent clinic (95% versus standard pediatric clinic (85%; OR 3.7; 95% confidence interval (CI 1.2-11.1; p = 0.018. Multivariable logistic regression adjusted for age at ART initiation, gender, pre-ART CD4 count, months on ART, and tuberculosis history indicated higher odds of retention in adolescents and young adults attending adolescent compared to standard clinic (AOR = 8.5; 95% CI 2.3-32.4; p = 0.002. Viral suppression was higher among adolescents and young adults attending adolescent (91% versus standard pediatric clinic (80%; OR 2.5; 95% CI 1.1-5.8; p = 0.028. A similar multivariable logistic regression model indicated higher odds of viral suppression in adolescents and young adults attending adolescent versus standard pediatric clinic (AOR = 3.8; 95% CI 1.5-9.7; p = 0.005.Adolescents and young adults attending an adolescent-friendly clinic had higher retention in care and viral suppression compared to adolescents attending the standard pediatric clinic. Further studies are needed to prospectively assess the impact of adolescent

Job embeddedness and nurse retention.

Science.gov (United States)

Reitz, O Ed; Anderson, Mary Ann; Hill, Pamela D

2010-01-01

Nurse retention is a different way of conceptualizing the employer-employee relationship when compared with turnover. Job embeddedness (JE), a construct based on retention, represents the sum of reasons why employees remain at their jobs. However, JE has not been investigated in relation to locale (urban or rural) or exclusively with a sample of registered nurses (RNs). The purpose of this study was to determine what factors (JE, age, gender, locale, and income) help predict nurse retention. A cross-sectional mailed survey design was used with RNs in different locales (urban or rural). Job embeddedness was measured by the score on the composite, standardized instrument. Nurse retention was measured by self-report items concerning intent to stay. A response rate of 49.3% was obtained. The typical respondent was female (96.1%), white, non-Hispanic (87.4%), and married (74.9%). Age and JE were predictive of nurse retention and accounted for 26% of the explained variance in intent to stay. Although age was a significant predictor of intent to stay, it accounted for only 1.4% of the variance while JE accounted for 24.6% of the variance of nurse retention (as measured by intent to stay). Older, more "embedded" nurses are more likely to remain employed in their current organization. Based on these findings, JE may form the basis for the development of an effective nurse retention program.

Pre-stimulus BOLD-network activation modulates EEG spectral activity during working memory retention

Directory of Open Access Journals (Sweden)

Mara eKottlow

2015-05-01

Full Text Available Working memory (WM processes depend on our momentary mental state and therefore exhibit considerable fluctuations. Here, we investigate the interplay of task-preparatory and task-related brain activity as represented by pre-stimulus BOLD-fluctuations and spectral EEG from the retention periods of a visual WM task. Visual WM is used to maintain sensory information in the brain enabling the performance of cognitive operations and is associated with mental health.We tested 22 subjects simultaneously with EEG and fMRI while performing a visuo-verbal Sternberg task with two different loads, allowing for the temporal separation of preparation, encoding, retention and retrieval periods.Four temporally coherent networks - the default mode network (DMN, the dorsal attention, the right and the left WM network - were extracted from the continuous BOLD data by means of a group ICA. Subsequently, the modulatory effect of these networks’ pre-stimulus activation upon retention-related EEG activity in the theta, alpha and beta frequencies was analyzed. The obtained results are informative in the context of state-dependent information processing.We were able to replicate two well-known load-dependent effects: the frontal-midline theta increase during the task and the decrease of pre-stimulus DMN activity. As our main finding, these two measures seem to depend on each other as the significant negative correlations at frontal-midline channels suggested. Thus, suppressed pre-stimulus DMN levels facilitated later task related frontal midline theta increases. In general, based on previous findings that neuronal coupling in different frequency bands may underlie distinct functions in WM retention, our results suggest that processes reflected by spectral oscillations during retention seem not only to be online synchronized with activity in different attention-related networks but are also modulated by activity in these networks during preparation intervals.

Calculation of retention time tolerance windows with absolute confidence from shared liquid chromatographic retention data.

Science.gov (United States)

Boswell, Paul G; Abate-Pella, Daniel; Hewitt, Joshua T

2015-09-18

Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user's system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called "retention projection" was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. Copyright © 2015 Elsevier B.V. All rights reserved.

Urinary retention in women

African Journals Online (AJOL)

Urinary retention in women. Urinary retention in women is often transient and of no known cause. ... stones, constipation, urethral cancer, uterine fibroids ... present with abnormal bladder function secondary to ... (CT), magnetic resonance imaging (MRI) or myelography ... full blood count, urea, electrolytes and creatinine can ...

Optimizing Time Intervals of Meteorological Data Used with Atmospheric Dose Modeling at SRS

International Nuclear Information System (INIS)

Simpkins, A.A.

1999-01-01

Measured tritium oxide concentrations in air have been compared with calculated values using routine release Gaussian plume models for different time intervals of meteorological data. These comparisons determined an optimum time interval of meteorological data used with atmospheric dose models at the Savannah River Site (SRS). Meteorological data of varying time intervals (1-yr to 10-yr) were used for the comparison. Insignificant differences are seen in using a one-year database as opposed to a five-year database. Use of a ten-year database results in slightly more conservative results. For meteorological databases of length one to five years the mean ratio of predicted to measured tritium oxide concentrations is approximately 1.25 whereas for the ten-year meteorological database the ration is closer to 1.35. Currently at the Savannah River Site a meteorological database of five years duration is used for all dose models. This study suggests no substantially improved accuracy using meteorological files of shorter or longer time intervals

Does Language Influence the Accuracy of Judgments of Stuttering in Children?

Science.gov (United States)

Einarsdottir, Johanna; Ingham, Roger J.

2009-01-01

Purpose: To determine whether stuttering judgment accuracy is influenced by familiarity with the stuttering speaker's language. Method: Audiovisual 7-min speech samples from nine 3- to 5-year-olds were used. Icelandic children who stutter (CWS), preselected for different levels of stuttering, were subdivided into 5-s intervals. Ten experienced…

76 FR 24089 - Credit Risk Retention

Science.gov (United States)

2011-04-29

... 17 CFR Part 246 Department of Housing and Urban Development 24 CFR Part 267 Credit Risk Retention... 2501-AD53 Credit Risk Retention AGENCIES: Office of the Comptroller of the Currency, Treasury (OCC..., Commission, FHFA, and HUD (the Agencies) are proposing rules to implement the credit risk retention...

Stepped-Wedge Cluster Randomized Controlled Trial to Promote Option B+ Retention in Central Mozambique.

Science.gov (United States)

Pfeiffer, James T; Napúa, Manuel; Wagenaar, Bradley H; Chale, Falume; Hoek, Roxanne; Micek, Mark; Manuel, João; Michel, Cathy; Cowan, Jessica Greenberg; Cowan, James F; Gimbel, Sarah; Sherr, Kenneth; Gloyd, Stephen; Chapman, Rachel R

2017-11-01

This randomized trial studied performance of Option B+ in Mozambique and evaluated an enhanced retention package in public clinics. The study was conducted at 6 clinics in Manica and Sofala Provinces in central Mozambique. Seven hundred sixty-one pregnant women tested HIV+, immediately initiated antiretroviral (ARV) therapy, and were followed to track retention at 6 clinics from May 2014 to May 2015. Clinics were randomly allocated within a stepped-wedge fashion to intervention and control periods. The intervention included (1) workflow modifications and (2) active patient tracking. Retention was defined as percentage of patients returning for 30-, 60-, and 90-day medication refills within 25-35 days of previous refills. During control periods, 52.3% of women returned for 30-day refills vs. 70.8% in intervention periods [odds ratio (OR): 1.80; 95% confidence interval (CI): 1.05 to 3.08]. At 60 days, 46.1% control vs. 57.9% intervention were retained (OR: 1.82; CI: 1.06 to 3.11), and at 90 days, 38.3% control vs. 41.0% intervention (OR: 1.04; CI: 0.60 to 1.82). In prespecified subanalyses, birth before pickups was strongly associated with failure-women giving birth before ARV pickup were 33.3 times (CI: 4.4 to 250.3), 7.5 times (CI: 3.6 to 15.9), and 3.7 times (CI: 2.2 to 6.0) as likely to not return for ARV pickups at 30, 60, and 90 days, respectively. The intervention was effective at 30 and 60 days, but not at 90 days. Combined 90-day retention (40%) and adherence (22.5%) were low. Efforts to improve retention are particularly important for women giving birth before ARV refills.

Retention capacity of correlated surfaces.

Science.gov (United States)

Schrenk, K J; Araújo, N A M; Ziff, R M; Herrmann, H J

2014-06-01

We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.

Retention capacity of correlated surfaces

OpenAIRE

Schrenk, K. J.; Araújo, N. A. M.; Ziff, R. M.; Herrmann, H. J.

2014-01-01

We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.

Effects of temperature and body size on radiocaesium retention in brown trout, Salmo trutta

International Nuclear Information System (INIS)

Ugedal, O.; Jonsson, B.; Njastad, O.; Naeumann, R.

1992-01-01

The elimination rate of radiocaesium in brown trout Salmo trutta L. was determined in the laboratory at four water temperatures (range 4.4 -15.6 0 C). In the experiments three or four homogeneous size-groups of fish (mean weights 23-496g) were studied at each temperature. The brown trout received acute oral doses of 134 Cs and were killed at intervals for radioactivity counting. The retention versus time curves were composed of two distinct exponential components. The long-lived component was quantitatively the most important for retention of radiocaesium. Elimination rate increased with increasing water temperature and decreased with increasing body weight. The biological half-life of 134 Cs (T b , days) was related to fresh body weight (W, g) and water temperature (t, 0 C) by the equation: T b = 290 x W 0.176 x e -0.106 x t . The elimination rate of Cs could be predicted from weight-specific metabolic rate as given by Elliott's equations for brown trout. (author)

Using Interval-Based Systems to Measure Behavior in Early Childhood Special Education and Early Intervention

Science.gov (United States)

Lane, Justin D.; Ledford, Jennifer R.

2014-01-01

The purpose of this article is to summarize the current literature on the accuracy and reliability of interval systems using data from previously published experimental studies that used either human observations of behavior or computer simulations. Although multiple comparison studies provided mathematical adjustments or modifications to interval…

The Elusive Universal Post-Mortem Interval Formula

Energy Technology Data Exchange (ETDEWEB)

Vass, Arpad Alexander [ORNL

2011-01-01

The following manuscript details our initial attempt at developing universal post-mortem interval formulas describing human decomposition. These formulas are empirically derived from data collected over the last 20 years from the University of Tennessee's Anthropology Research Facility, in Knoxville, Tennessee, USA. Two formulas were developed (surface decomposition and burial decomposition) based on temperature, moisture, and the partial pressure of oxygen, as being three of the four primary drivers for human decomposition. It is hoped that worldwide application of these formulas to environments and situations not readily studied in Tennessee will result in interdisciplinary cooperation between scientists and law enforcement personnel that will allow for future refinements of these models leading to increased accuracy.

Intestinal absorption and retention of cadmium in neonatal pigs compared to rats and guinea pigs

International Nuclear Information System (INIS)

Sasser, L.B.; Jarboe, G.E.

1980-01-01

The purpose of this study was to measure intestinal absorption and retention of cadmium in the newborn pig and to compare data from the pig, rat and guinea pig, three species that differ greatly in their ability to absorb macromolecules at birth. Newborn pigs were administered a single oral dose of 50 μCi of /sup 115m/Cd 24 hours after birth and killed at intervals between 1 and 14 days after dosing. Cd absorption and gastrointestinal retention were then determined; these data were compared with similar data from the rat and guinea pig. Cd absorption in the neonate appears to be a two-step process; mucosal uptake of Cd from the lumen, probably by pinocytosis, followed by transfer of a portion of this Cd into the body. This transfer process is similar, but does not entirely coincide with changes associated with protein absorption in the neonate

Dead-time corrections on long-interval measurements of short-lived activities

International Nuclear Information System (INIS)

Irfan, M.

1977-01-01

A method has been proposed to make correction for counting losses due to dead time where the counting interval is comparable to or larger than the half-life of the activity under investigation. Counts due to background and any long-lived activity present in the source have been taken into consideration. The method is, under certain circumstances, capable of providing a valuable check on the accuracy of the dead time of the counting system. (Auth.)

The Applicability of Confidence Intervals of Quantiles for the Generalized Logistic Distribution

Science.gov (United States)

Shin, H.; Heo, J.; Kim, T.; Jung, Y.

2007-12-01

The generalized logistic (GL) distribution has been widely used for frequency analysis. However, there is a little study related to the confidence intervals that indicate the prediction accuracy of distribution for the GL distribution. In this paper, the estimation of the confidence intervals of quantiles for the GL distribution is presented based on the method of moments (MOM), maximum likelihood (ML), and probability weighted moments (PWM) and the asymptotic variances of each quantile estimator are derived as functions of the sample sizes, return periods, and parameters. Monte Carlo simulation experiments are also performed to verify the applicability of the derived confidence intervals of quantile. As the results, the relative bias (RBIAS) and relative root mean square error (RRMSE) of the confidence intervals generally increase as return period increases and reverse as sample size increases. And PWM for estimating the confidence intervals performs better than the other methods in terms of RRMSE when the data is almost symmetric while ML shows the smallest RBIAS and RRMSE when the data is more skewed and sample size is moderately large. The GL model was applied to fit the distribution of annual maximum rainfall data. The results show that there are little differences in the estimated quantiles between ML and PWM while distinct differences in MOM.

Uncovering client retention antecedents in service organizations

Directory of Open Access Journals (Sweden)

Mari Jansen van Rensburg

2014-01-01

Full Text Available This paper develops a multi-dimensional model of retention to provide a more complete and integrated view of client retention and its determinants in service contexts. To uncover the antecedents of client retention, social and economic exchanges were reviewed under the fundamental ideas of the Social Exchange Theory. Findings from a survey of senior South African advertising executives suggest that client retention is the result of evaluative as well as relational factors that can influence client responses. Despite contractual obligations, advertisers are willing to pay the costs and make the sacrifices of switching should their expectations be unmet. An important contribution of this study is the use of multi-item scales to measure retention. The model developed provides valuable insight to agencies on client retention management and the optimal allocation of resources for maximum customer equity. This model may also be applied to other service organisations to provide insight to client retention.

Retention of black and white participants in the selenium and vitamin E cancer prevention trial (SWOG-coordinated intergroup study S0000).

Science.gov (United States)

Arnold, Kathryn B; Hermos, John A; Anderson, Karen B; Minasian, Lori; Tangen, Catherine M; Probstfield, Jeffrey F; Cook, Elise D

2014-12-01

Disproportionally low retention of minority populations can adversely affect the generalizability of clinical research trials. We determine the overall retention rates for White and Black participants from the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and explore participant and site characteristics associated with retention failure (study disengagement) for these groups. A secondary analysis of 28,118 White (age ≥55), and 4,322 Black (age ≥ 50) SELECT participants used multivariate Cox regression to estimate overall retention rates and to calculate HRs and 95% confidence intervals (CI). Blacks had higher age-adjusted risk of disengagement than Whites (HR, 1.92; 95% CI, 1.77-2.08). Among Black participants, those ages 50 to 54 were at three times the risk of disengagement than those ≥65 years of age (HR, 3.61; 95% CI, 2.41-5.41). Blacks age ≥65 had 1.6 times the risk of disengagement than Whites age ≥65 (HR, 1.60; 95% CI, 1.38-1.87). By 6 years after randomization, 84% of Whites and 69% of Blacks remained engaged in the study. Current smoking status was an independent risk factor for study disengagement for both White and Black participants. For both groups, sites whose staffs missed SELECT training sessions or who received SELECT Retention and Adherence grants were associated with increased and decreased disengagement risks, respectively. SELECT retention was disproportionately lower for Blacks than for Whites. The observed difference in retention rates for Blacks and Whites and factors identified by race for study disengagement in SELECT may inform retention efforts for future long-term, cancer prevention trials. ©2014 American Association for Cancer Research.

Retention of Emergency Care Knowledge.

Science.gov (United States)

Burckes, Mardie E.; Shao, Kung Ping Pam

1984-01-01

Data on the emergency care knowledge of college students were measured by a pretest, posttest, and retention test. A high relationship was found between students' posttest scores and retention test scores. Findings are discussed. (Author/DF)

The Time Is Up: Compression of Visual Time Interval Estimations of Bimodal Aperiodic Patterns

Science.gov (United States)

Duarte, Fabiola; Lemus, Luis

2017-01-01

The ability to estimate time intervals subserves many of our behaviors and perceptual experiences. However, it is not clear how aperiodic (AP) stimuli affect our perception of time intervals across sensory modalities. To address this question, we evaluated the human capacity to discriminate between two acoustic (A), visual (V) or audiovisual (AV) time intervals of trains of scattered pulses. We first measured the periodicity of those stimuli and then sought for correlations with the accuracy and reaction times (RTs) of the subjects. We found that, for all time intervals tested in our experiment, the visual system consistently perceived AP stimuli as being shorter than the periodic (P) ones. In contrast, such a compression phenomenon was not apparent during auditory trials. Our conclusions are: first, the subjects exposed to P stimuli are more likely to measure their durations accurately. Second, perceptual time compression occurs for AP visual stimuli. Lastly, AV discriminations are determined by A dominance rather than by AV enhancement. PMID:28848406

Convex Interval Games

NARCIS (Netherlands)

Alparslan-Gok, S.Z.; Brânzei, R.; Tijs, S.H.

2008-01-01

In this paper, convex interval games are introduced and some characterizations are given. Some economic situations leading to convex interval games are discussed. The Weber set and the Shapley value are defined for a suitable class of interval games and their relations with the interval core for

Experimental designs for modeling retention patterns and separation efficiency in analysis of fatty acid methyl esters by gas chromatography-mass spectrometry.

Science.gov (United States)

Skartland, Liv Kjersti; Mjøs, Svein A; Grung, Bjørn

2011-09-23

The retention behavior of components analyzed by chromatography varies with instrumental settings. Being able to predict how changes in these settings alter the elution pattern is useful, both with regards to component identification, as well as with regards to optimization of the chromatographic system. In this work, it is shown how experimental designs can be used for this purpose. Different experimental designs for response surface modeling of the separation of fatty acid methyl esters (FAME) as function of chromatographic conditions in GC have been evaluated. Full factorial, central composite, Doehlert and Box-Behnken designs were applied. A mixture of 38 FAMEs was separated on a polar cyanopropyl substituted polysilphenylene-siloxane phase capillary column. The temperature gradient, the start temperature of the gradient, and the carrier gas velocity were varied in the experiments. The modeled responses, as functions of chromatographic conditions, were retention time, retention indices, peak widths, separation efficiency and resolution between selected peak pairs. The designs that allowed inclusion of quadratic terms among the predictors performed significantly better than factorial design. Box-Behnken design provided the best results for prediction of retention, but the differences between the central composite, Doehlert and Box-Behnken designs were small. Retention indices could be modeled with much better accuracy than retention times. However, because the errors of predicted tR of closely eluting peaks were highly correlated, models of resolution (Rs) that were based on retention time had errors in the same range as corresponding models based on ECL. Copyright © 2011 Elsevier B.V. All rights reserved.

Accuracy Assessment of Different Digital Surface Models

Directory of Open Access Journals (Sweden)

Ugur Alganci

2018-03-01

Full Text Available Digital elevation models (DEMs, which can occur in the form of digital surface models (DSMs or digital terrain models (DTMs, are widely used as important geospatial information sources for various remote sensing applications, including the precise orthorectification of high-resolution satellite images, 3D spatial analyses, multi-criteria decision support systems, and deformation monitoring. The accuracy of DEMs has direct impacts on specific calculations and process chains; therefore, it is important to select the most appropriate DEM by considering the aim, accuracy requirement, and scale of each study. In this research, DSMs obtained from a variety of satellite sensors were compared to analyze their accuracy and performance. For this purpose, freely available Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER 30 m, Shuttle Radar Topography Mission (SRTM 30 m, and Advanced Land Observing Satellite (ALOS 30 m resolution DSM data were obtained. Additionally, 3 m and 1 m resolution DSMs were produced from tri-stereo images from the SPOT 6 and Pleiades high-resolution (PHR 1A satellites, respectively. Elevation reference data provided by the General Command of Mapping, the national mapping agency of Turkey—produced from 30 cm spatial resolution stereo aerial photos, with a 5 m grid spacing and ±3 m or better overall vertical accuracy at the 90% confidence interval (CI—were used to perform accuracy assessments. Gross errors and water surfaces were removed from the reference DSM. The relative accuracies of the different DSMs were tested using a different number of checkpoints determined by different methods. In the first method, 25 checkpoints were selected from bare lands to evaluate the accuracies of the DSMs on terrain surfaces. In the second method, 1000 randomly selected checkpoints were used to evaluate the methods’ accuracies for the whole study area. In addition to the control point approach, vertical cross

Assessment of nutrient retention by Natete wetland Kampala, Uganda

Science.gov (United States)

Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

New precession expressions, valid for long time intervals

Science.gov (United States)

Vondrák, J.; Capitaine, N.; Wallace, P.

2011-10-01

Context. The present IAU model of precession, like its predecessors, is given as a set of polynomial approximations of various precession parameters intended for high-accuracy applications over a limited time span. Earlier comparisons with numerical integrations have shown that this model is valid only for a few centuries around the basic epoch, J2000.0, while for more distant epochs it rapidly diverges from the numerical solution. In our preceding studies we also obtained preliminary developments for the precessional contribution to the motion of the equator: coordinates X,Y of the precessing pole and precession parameters ψA,ωA, suitable for use over long time intervals. Aims: The goal of the present paper is to obtain upgraded developments for various sets of precession angles that would fit modern observations near J2000.0 and at the same time fit numerical integration of the motions of solar system bodies on scales of several thousand centuries. Methods: We used the IAU 2006 solutions to represent the precession of the ecliptic and of the equator close to J2000.0 and, for more distant epochs, a numerical integration using the Mercury 6 package and solutions by Laskar et al. (1993, A&A, 270, 522) with upgraded initial conditions and constants to represent the ecliptic, and general precession and obliquity, respectively. From them, different precession parameters were calculated in the interval ± 200 millennia from J2000.0, and analytical expressions are found that provide a good fit for the whole interval. Results: Series for the various precessional parameters, comprising a cubic polynomial plus from 8 to 14 periodic terms, are derived that allow precession to be computed with an accuracy comparable to IAU 2006 around the central epoch J2000.0, a few arcseconds throughout the historical period, and a few tenths of a degree at the ends of the ± 200 millennia time span. Computer algorithms are provided that compute the ecliptic and mean equator poles and the

Four-Week Strategy-Based Training to Enhance Prospective Memory in Older Adults: Targeting Intention Retention Is More Beneficial than Targeting Intention Formation.

Science.gov (United States)

Ihle, Andreas; Albiński, Rafal; Gurynowicz, Kamila; Kliegel, Matthias

2018-01-01

So far, training of prospective memory (PM) focused on very short instances (single sessions) and targeted the intention-formation phase only. We aimed to compare the effectiveness of 2 different 4-week strategy-based PM training types, namely imagery training (targeting the encoding of the PM intention in the intention-formation phase) versus rehearsal training (targeting the maintenance of the PM intention in the intention-retention phase) in older adults. We used a 4-week training protocol (8 sessions in total, 2 sessions per week). From the 44 participants, 21 were randomly assigned to the imagery training (vividly imagining a mental picture to memorize the connection between the PM cue words and related actions during intention formation) and 23 to the rehearsal training (rehearsing the PM cue words during intention retention). The criterion PM task was assessed before and after the training. Comparing the effectiveness of both training types, we found a significant time by training type interaction on PM accuracy in terms of PM cue detection, F(1, 42) = 6.07, p = 0.018, η2p = 0.13. Subsequent analyses revealed that the rehearsal training was more effective in enhancing PM accuracy in terms of PM cue detection than the imagery training. Strategy-based PM training in older adults targeting the maintenance of the PM intention in the intention-retention phase may be more effective in enhancing PM accuracy in terms of PM cue detection than the strategy targeting the encoding of the PM intention in the intention-formation phase. This suggests that for successful prospective remembering, older adults may need more support to keep the PM cues active in memory while working on the ongoing task than to initially encode the PM intention. © 2018 S. Karger AG, Basel.

Restricted Interval Valued Neutrosophic Sets and Restricted Interval Valued Neutrosophic Topological Spaces

Directory of Open Access Journals (Sweden)

Anjan Mukherjee

2016-08-01

Full Text Available In this paper we introduce the concept of restricted interval valued neutrosophic sets (RIVNS in short. Some basic operations and properties of RIVNS are discussed. The concept of restricted interval valued neutrosophic topology is also introduced together with restricted interval valued neutrosophic finer and restricted interval valued neutrosophic coarser topology. We also define restricted interval valued neutrosophic interior and closer of a restricted interval valued neutrosophic set. Some theorems and examples are cites. Restricted interval valued neutrosophic subspace topology is also studied.

Confidence Intervals Verification for Simulated Error Rate Performance of Wireless Communication System

KAUST Repository

Smadi, Mahmoud A.

2012-12-06

In this paper, we derived an efficient simulation method to evaluate the error rate of wireless communication system. Coherent binary phase-shift keying system is considered with imperfect channel phase recovery. The results presented demonstrate the system performance under very realistic Nakagami-m fading and additive white Gaussian noise channel. On the other hand, the accuracy of the obtained results is verified through running the simulation under a good confidence interval reliability of 95 %. We see that as the number of simulation runs N increases, the simulated error rate becomes closer to the actual one and the confidence interval difference reduces. Hence our results are expected to be of significant practical use for such scenarios. © 2012 Springer Science+Business Media New York.

Accuracy of lung nodule density on HRCT: analysis by PSF-based image simulation.

Science.gov (United States)

Ohno, Ken; Ohkubo, Masaki; Marasinghe, Janaka C; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

2012-11-08

A computed tomography (CT) image simulation technique based on the point spread function (PSF) was applied to analyze the accuracy of CT-based clinical evaluations of lung nodule density. The PSF of the CT system was measured and used to perform the lung nodule image simulation. Then, the simulated image was resampled at intervals equal to the pixel size and the slice interval found in clinical high-resolution CT (HRCT) images. On those images, the nodule density was measured by placing a region of interest (ROI) commonly used for routine clinical practice, and comparing the measured value with the true value (a known density of object function used in the image simulation). It was quantitatively determined that the measured nodule density depended on the nodule diameter and the image reconstruction parameters (kernel and slice thickness). In addition, the measured density fluctuated, depending on the offset between the nodule center and the image voxel center. This fluctuation was reduced by decreasing the slice interval (i.e., with the use of overlapping reconstruction), leading to a stable density evaluation. Our proposed method of PSF-based image simulation accompanied with resampling enables a quantitative analysis of the accuracy of CT-based evaluations of lung nodule density. These results could potentially reveal clinical misreadings in diagnosis, and lead to more accurate and precise density evaluations. They would also be of value for determining the optimum scan and reconstruction parameters, such as image reconstruction kernels and slice thicknesses/intervals.

On the optimal design of risk retention in securitisation

Directory of Open Access Journals (Sweden)

Metin Kaptan

2011-09-01

Full Text Available This paper examines the optimal design of retention in securitisation, in order to maximize welfare of screening per unit of retention, assuming that screening is costly and that the bank intends to securitise its loans. In contrast to the focus of previous literature on tranche retention, we deviate from the constitutional mechanisms of tranche retention to present a pareto-optimal method of tranche retention. Unlike the current ad-hoc-regulations, we derive the optimal design of retention from a utility maximization problem. We show that the level of retention per tranche should be dependent on the rate of credit default, i.e. the higher the rate of default, the higher the optimal rate of retention required to provide an incentive to screen carefully. From this approach, it follows that the rate of retention per tranche should be higher, the higher the position within the ranking order of subordination. Accordingly, the efficiency of tranche retention can be enhanced, reducing the level of retention required to maintain a given level of screening-effort. This retention design entails a recovery of the bank’s equity capital, thereby increasing liquidity and lending capacities.

RBANS memory percentage retention: No evidence of incremental validity beyond RBANS scores for diagnostic classification of mild cognitive impairment and dementia and for prediction of daily function.

Science.gov (United States)

Jodouin, Kara A; O'Connell, Megan E; Morgan, Debra G

2017-01-01

RBANS percentage retention scores may be useful for diagnosis, but their incremental validity is unclear. Percentage retention versus RBANS immediate and delayed memory subtests and delayed index scores were compared for diagnostic classification and for prediction of function. Data from 173 memory clinic patients with an interdisciplinary diagnosis (no cognitive impairment, amnestic mild cognitive impairment [aMCI], and dementia due to Alzheimer's disease [AD]) and complete RBANS data were analyzed. Across diagnostic contrasts, list percentage retention classification accuracy was similar to List Learning delayed recall, but below the Delayed Memory Index (DMI). Similarly, for classifying no cognitive impairment versus aMCI or dementia due to AD, story percentage retention was similar to Story Memory subtests and below the DMI. For classifying aMCI versus AD; however, Story Memory exceeded the DMI, but was similar to Story Memory subtest scores. Similarly, for prediction of function percentage retention measures did not predict variance beyond that predicted by the RBANS subtest or index scores. In sum, there is no evidence that calculation of percentage retention for RBANS adds clinical utility beyond those provided by the standard RBANS scores.

Predicting turnover and retention in nursing home administrators: management and policy implications.

Science.gov (United States)

Singh, D A; Schwab, R C

2000-06-01

Administrator turnover and its impact on the quality of patient care are important concerns in the nursing home industry. This study evaluates a model to determine which factors, attitudes, and personal characteristics can predict tenure. Responses to a survey from 290 nursing home administrators (NHAs) who furnished data on their previous positions were analyzed using logistic regression methods. The extracted model correlates tenure with the administrator's past patterns of stability, community attachment, organizational commitment, and facility performance. The model is particularly effective (85% accuracy) in flagging NHAs who are likely to depart within their first 3 years of employment. Implications of these findings for recruitment, retention, and licensure policy are discussed.

Encoding vs. retention: differential effects of cue manipulation on working memory performance in schizophrenia.

Science.gov (United States)

Javitt, Daniel C; Rabinowicz, Esther; Silipo, Gail; Dias, Elisa C

2007-03-01

Deficits in working memory performance are among the most widely replicated findings in schizophrenia. Roles of encoding vs. memory retention in working memory remain unresolved. The present study evaluated working memory performance in schizophrenia using an AX-type continuous performance test (AX-CPT) paradigm. Participants included 48 subjects with schizophrenia and 27 comparison subjects. Behavior was obtained in 3 versions of the task, which differed based upon ease of cue interoperability. In a simple cue version of the task, cue letters were replaced with red or green circles. In the complex cue version, letter/color conjunctions served as cues. In the base version of the task, patients showed increased rates of false alarms to invalidly cued targets, similar to prior reports. However, when the cue stimuli were replaced with green or red circles to ease interpretation, patients showed similar false alarm rates to controls. When feature conjunction cues were used, patients were also disproportionately affected relative to controls. No significant group by interstimulus interval interaction effects were observed in either the simple or complex cue conditions, suggesting normal retention of information even in the presence of overall performance decrements. These findings suggest first, that cue manipulation disproportionately affects AX-CPT performance in schizophrenia and, second, that substantial behavioral deficits may be observed on working memory tasks even in the absence of disturbances in mnemonic retention.

Temporal determinants of long-term retention of olfactory memory in the cricket Gryllus bimaculatus.

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Matsumoto, Yukihisa; Mizunami, Makoto

2002-05-01

Temporal determinants of olfactory long-term memory retention in the cricket Gryllus bimaculatus were studied. Elementary appetitive and aversive conditioning procedures, as well as a differential conditioning procedure, were applied. In appetitive conditioning, peppermint odour was paired with a water reward. In aversive conditioning, vanilla odour was paired with saline solution. In differential conditioning, an appetitive conditioning trial was followed by an aversive conditioning trial. The odour preference of crickets was tested before and 2 h, 1 day and 4 days after training by allowing the crickets to choose between peppermint or vanilla sources. Differential conditioning or appetitive conditioning alone led to long-lasting memory retention with no significant decay from 2 h to 4 days after training, but retention after aversive conditioning was absent 1 day after training. Studies using differential conditioning have shown (i) that four trials are sufficient to cause a saturated level of acquisition, (ii) that conditioning is successful when the conditioned stimulus is presented immediately or 5 s before the onset of presentation of the unconditioned stimulus, (iii) that the optimal interval between trials is 2-5 min, and (iv) that anaesthetic treatment with CO2 given immediately after training results in memory disruption but that anaesthetic-resistant memory develops fully 20 min after training. This study demonstrates that a differential conditioning procedure is particularly effective for the formation of long-term memory.

Data Retention and Anonymity Services

Science.gov (United States)

Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

Retention among ART patients in the Highlands of Papua New Guinea: evaluating the PAPUA model.

Science.gov (United States)

Das, Sarthak; Carmone, Andy; Franke, Molly F; Frank, Dale; Kiromat, Hannelly; Kaima, Petronia; Kiromat, Mobumo

2014-02-01

Despite more than 10,000 patients on antiretroviral therapy (ART), there remains a dearth of operational research in Papua New Guinea related to HIV service delivery. This study examined the effectiveness of a locally developed model of HIV service delivery called PAPUA (Patient and Provider Unified Approach) in the Highlands of Papua New Guinea. The model emphasizes coordinated patient and provider support along with decentralized services to rural districts in the Highlands. We conducted a chart review among HIV-infected adults on ART at clinics in Eastern Highlands Province, where the PAPUA model was implemented in addition to the standard of care, and in Western Highlands Province, where the standard of care was implemented. We calculated yearly retention rates and used multivariable Cox proportional hazards regression analyses to compare retention rates across the provinces. Data for 2457 patients from the 2 provinces were analyzed. Among patients receiving ART under the PAPUA model in Eastern Highlands, the 12-, 24-, 36-, and 48-month retention proportions were 0.79, 0.73, 0.68, and 0.63, respectively. When we compared retention probabilities across the 2 provinces, patients receiving care under the PAPUA model had a 15% lower rate of attrition from care during the first 4 years of ART (hazard ratio, 0.85; 95% confidence interval: 0.74 to 0.99; P = 0.03), after adjusting for age, gender, and year of enrollment. The PAPUA model seems to be a promising intervention although it is inextricably linked to the limitations posed by a resource-constrained health system.

An ROC-type measure of diagnostic accuracy when the gold standard is continuous-scale.

Science.gov (United States)

Obuchowski, Nancy A

2006-02-15

ROC curves and summary measures of accuracy derived from them, such as the area under the ROC curve, have become the standard for describing and comparing the accuracy of diagnostic tests. Methods for estimating ROC curves rely on the existence of a gold standard which dichotomizes patients into disease present or absent. There are, however, many examples of diagnostic tests whose gold standards are not binary-scale, but rather continuous-scale. Unnatural dichotomization of these gold standards leads to bias and inconsistency in estimates of diagnostic accuracy. In this paper, we propose a non-parametric estimator of diagnostic test accuracy which does not require dichotomization of the gold standard. This estimator has an interpretation analogous to the area under the ROC curve. We propose a confidence interval for test accuracy and a statistical test for comparing accuracies of tests from paired designs. We compare the performance (i.e. CI coverage, type I error rate, power) of the proposed methods with several alternatives. An example is presented where the accuracies of two quick blood tests for measuring serum iron concentrations are estimated and compared.

Retention of Vaginal Breech Delivery Skills Taught in Simulation.

Science.gov (United States)

Stone, Heather; Crane, Joan; Johnston, Kathy; Craig, Catherine

2018-02-01

The optimal frequency of conducting simulation training for high-acuity, low-frequency events in obstetrics and gynaecology residency programs is unknown. This study evaluated retention over time of vaginal breech delivery skills taught in simulation, by comparing junior and senior residents. In addition, the residents' subjective comfort level to perform this skill clinically was assessed. This prospective cohort study included 22 obstetrics and gynaecology residents in a Canadian residency training program. Digital recordings were completed for pre-training, immediate post-training, and delayed (10-26 weeks later) post-training intervals of a vaginal breech delivery simulation, with skill assessment by a blinded observer using a binary checklist. Residents also completed questionnaires to assess their subjective comfort level at each interval. Junior and senior residents had significant improvements in vaginal breech delivery skills from the pre-training assessment to both the immediate post-training assessment (junior, P simulation 10-26 weeks later, although a decline in skills occurred over this time period. Comfort level was positively affected and retained. These results will aid in determining the frequency of simulation teaching for high-acuity, low-frequency events in a residency simulation curriculum. Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.

Intrinsic and Induced Arousal in the Short- and Long-Term Retention of Film Content by Elementary School Children in Puerto Rico. Technical Report No. 274.

Science.gov (United States)

Santiago, Salvador; Farley, Frank H.

A study was designed to examine the contribution of intrinsic arousal (individual differences) and induced arousal to children's comprehension of film content with short- and long-term retention intervals. Intrinsic arousal was measured by a salivary response measure; induced arousal was manipulated by white auditory noise. The latter was…

Cross-Linked Fluorescent Supramolecular Nanoparticles as Finite Tattoo Pigments with Controllable Intradermal Retention Times.

Science.gov (United States)

Choi, Jin-Sil; Zhu, Yazhen; Li, Hongsheng; Peyda, Parham; Nguyen, Thuy Tien; Shen, Mo Yuan; Yang, Yang Michael; Zhu, Jingyi; Liu, Mei; Lee, Mandy M; Sun, Shih-Sheng; Yang, Yang; Yu, Hsiao-Hua; Chen, Kai; Chuang, Gary S; Tseng, Hsian-Rong

2017-01-24

Tattooing has been utilized by the medical community for precisely demarcating anatomic landmarks. This practice is especially important for identifying biopsy sites of nonmelanoma skin cancer (NMSC) due to the long interval (i.e., up to 3 months) between the initial diagnostic biopsy and surgical treatment. Commercially available tattoo pigments possess several issues, which include causing poor cosmesis, being mistaken for a melanocytic lesion, requiring additional removal procedures when no longer desired, and potentially inducing inflammatory responses. The ideal tattoo pigment for labeling of skin biopsy sites for NMSC requires (i) invisibility under ambient light, (ii) fluorescence under a selective light source, (iii) a finite intradermal retention time (ca. 3 months), and (iv) biocompatibility. Herein, we introduce cross-linked fluorescent supramolecular nanoparticles (c-FSNPs) as a "finite tattoo" pigment, with optimized photophysical properties and intradermal retention time to achieve successful in vivo finite tattooing. Fluorescent supramolecular nanoparticles encapsulate a fluorescent conjugated polymer, poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene] (MPS-PPV), into a core via a supramolecular synthetic approach. FSNPs which possess fluorescent properties superior to those of the free MPS-PPV are obtained through a combinatorial screening process. Covalent cross-linking of FSNPs results in micrometer-sized c-FSNPs, which exhibit a size-dependent intradermal retention. The 1456 nm sized c-FSNPs display an ideal intradermal retention time (ca. 3 months) for NMSC lesion labeling, as observed in an in vivo tattoo study. In addition, the c-FSNPs induce undetectable inflammatory responses after tattooing. We believe that the c-FSNPs can serve as a "finite tattoo" pigment to label potential malignant NMSC lesions.

Best practices in doctoral retention: Mentoring

Directory of Open Access Journals (Sweden)

Judie L. Brill

2014-06-01

Full Text Available  The aim of this critical literature review is to outline best practices in doctoral retention and the successful approach of one university to improve graduation success by providing effective mentorship for faculty and students alike. The focus of this literature review is on distance learning relationships between faculty and doctoral students, regarding retention, persistence, and mentoring models. Key phrases and words used in the search and focusing on mentoring resulted in over 20,000 sources. The search was narrowed to include only doctoral study and mentoring. Research questions of interest were: Why do high attrition rates exist for doctoral students? What are the barriers to retention? What are the benefits of doctoral mentoring? What programs do institutions have in place to reduce attrition? The researchers found a key factor influencing doctoral student retention and success is effective faculty mentorship. In particular, the design of a mentoring and faculty training program to increase retention and provide for success after graduation is important. This research represents a key area of interest in the retention literature, as institutions continue to search for ways to better support students during their doctoral programs and post-graduation. DOI: 10.18870/hlrc.v4i2.186

Enhanced Personal Contact With HIV Patients Improves Retention in Primary Care: A Randomized Trial in 6 US HIV Clinics

Science.gov (United States)

Gardner, Lytt I.; Giordano, Thomas P.; Marks, Gary; Wilson, Tracey E.; Craw, Jason A.; Drainoni, Mari-Lynn; Keruly, Jeanne C.; Rodriguez, Allan E.; Malitz, Faye; Moore, Richard D.; Bradley-Springer, Lucy A.; Holman, Susan; Rose, Charles E.; Girde, Sonali; Sullivan, Meg; Metsch, Lisa R.; Saag, Michael; Mugavero, Michael J.; Drainoni, Mari-Lynn; Ferreira, Cintia; Koppelman, Lisa; McDoom, Maya; Naisteter, Michal; Osella, Karina; Ruiz, Glory; Skolnik, Paul; Sullivan, Meg; Gibbs-Cohen, Sophia; Desrivieres, Elana; Frederick, Mayange; Gravesande, Kevin; Holman, Susan; Johnson, Harry; Taylor, Tonya; Wilson, Tracey; Cheever, Laura; Malitz, Faye; Mills, Robert; Craw, Jason; Gardner, Lytt; Girde, Sonali; Marks, Gary; Batey, Scott; Gaskin, Stephanie; Mugavero, Michael; Murphree, Jill; Raper, Jim; Saag, Michael; Thogaripally, Suneetha; Willig, James; Zinski, Anne; Arya, Monisha; Bartholomew, David; Biggs, Tawanna; Budhwani, Hina; Davila, Jessica; Giordano, Tom; Miertschin, Nancy; Payne, Shapelle; Slaughter, William; Jenckes, Mollie; Keruly, Jeanne; McCray, Angie; McGann, Mary; Moore, Richard; Otterbein, Melissa; Zhou, Liming; Garzon, Carolyn; Jean-Simon, Jesline; Mercogliano, Kathy; Metsch, Lisa; Rodriguez, Allan; Saint-Jean, Gilbert; Shika, Marvin; Bradley-Springer, Lucy; Corwin, Marla

2014-01-01

Background. The aim of the study was to determine whether enhanced personal contact with human immunodeficiency virus (HIV)–infected patients across time improves retention in care compared with existing standard of care (SOC) practices, and whether brief skills training improves retention beyond enhanced contact. Methods. The study, conducted at 6 HIV clinics in the United States, included 1838 patients with a recent history of inconsistent clinic attendance, and new patients. Each clinic randomized participants to 1 of 3 arms and continued to provide SOC practices to all enrollees: enhanced contact with interventionist (EC) (brief face-to-face meeting upon returning for care visit, interim visit call, appointment reminder calls, missed visit call); EC + skills (organization, problem solving, and communication skills); or SOC only. The intervention was delivered by project staff for 12 months following randomization. The outcomes during that 12-month period were (1) percentage of participants attending at least 1 primary care visit in 3 consecutive 4-month intervals (visit constancy), and (2) proportion of kept/scheduled primary care visits (visit adherence). Results. Log-binomial risk ratios comparing intervention arms against the SOC arm demonstrated better outcomes in both the EC and EC + skills arms (visit constancy: risk ratio [RR], 1.22 [95% confidence interval {CI}, 1.09–1.36] and 1.22 [95% CI, 1.09–1.36], respectively; visit adherence: RR, 1.08 [95% CI, 1.05–1.11] and 1.06 [95% CI, 1.02–1.09], respectively; all Ps < .01). Intervention effects were observed in numerous patient subgroups, although they were lower in patients reporting unmet needs or illicit drug use. Conclusions. Enhanced contact with patients improved retention in HIV primary care compared with existing SOC practices. A brief patient skill-building component did not improve retention further. Additional intervention elements may be needed for patients reporting illicit

Enhanced personal contact with HIV patients improves retention in primary care: a randomized trial in 6 US HIV clinics.

Science.gov (United States)

Gardner, Lytt I; Giordano, Thomas P; Marks, Gary; Wilson, Tracey E; Craw, Jason A; Drainoni, Mari-Lynn; Keruly, Jeanne C; Rodriguez, Allan E; Malitz, Faye; Moore, Richard D; Bradley-Springer, Lucy A; Holman, Susan; Rose, Charles E; Girde, Sonali; Sullivan, Meg; Metsch, Lisa R; Saag, Michael; Mugavero, Michael J

2014-09-01

The aim of the study was to determine whether enhanced personal contact with human immunodeficiency virus (HIV)-infected patients across time improves retention in care compared with existing standard of care (SOC) practices, and whether brief skills training improves retention beyond enhanced contact. The study, conducted at 6 HIV clinics in the United States, included 1838 patients with a recent history of inconsistent clinic attendance, and new patients. Each clinic randomized participants to 1 of 3 arms and continued to provide SOC practices to all enrollees: enhanced contact with interventionist (EC) (brief face-to-face meeting upon returning for care visit, interim visit call, appointment reminder calls, missed visit call); EC + skills (organization, problem solving, and communication skills); or SOC only. The intervention was delivered by project staff for 12 months following randomization. The outcomes during that 12-month period were (1) percentage of participants attending at least 1 primary care visit in 3 consecutive 4-month intervals (visit constancy), and (2) proportion of kept/scheduled primary care visits (visit adherence). Log-binomial risk ratios comparing intervention arms against the SOC arm demonstrated better outcomes in both the EC and EC + skills arms (visit constancy: risk ratio [RR], 1.22 [95% confidence interval {CI}, 1.09-1.36] and 1.22 [95% CI, 1.09-1.36], respectively; visit adherence: RR, 1.08 [95% CI, 1.05-1.11] and 1.06 [95% CI, 1.02-1.09], respectively; all Ps effects were observed in numerous patient subgroups, although they were lower in patients reporting unmet needs or illicit drug use. Enhanced contact with patients improved retention in HIV primary care compared with existing SOC practices. A brief patient skill-building component did not improve retention further. Additional intervention elements may be needed for patients reporting illicit drug use or who have unmet needs. CDCHRSA9272007. Published by Oxford University

Driving factors of retention in care among HIV-positive MSM and transwomen in Indonesia: A cross-sectional study

Science.gov (United States)

Erasmus, Vicki; Coulter, Robert W. S.; Koirala, Sushil; Nampaisan, Oranuch; Pamungkas, Wirastra; Richardus, Jan Hendrik

2018-01-01

Little is known about the prevalence of and factors that influence retention in HIV-related care among Indonesian men who have sex with men (MSM) and transgender women (transwomen, or waria in Indonesian term). Therefore, we explored the driving factors of retention in care among HIV-positive MSM and waria in Indonesia. This cross-sectional study involved 298 self-reported HIV-positive MSM (n = 165) and waria (n = 133). Participants were recruited using targeted sampling and interviewed using a structured questionnaire. We applied a four-step model building process using multivariable logistic regression to examine how sociodemographic, predisposing, enabling, and reinforcing factors were associated with retention in care. Overall, 78.5% of participants were linked to HIV care within 3 months after diagnosis or earlier, and 66.4% were adequately retained in care (at least one health care visit every three months once a person is diagnosed with HIV). Being on antiretroviral therapy (adjusted odds ratio [AOR] = 6.00; 95% confidence interval [CI]: 2.93–12.3), using the Internet to find HIV-related information (AOR = 2.15; 95% CI: 1.00–4.59), and having medical insurance (AOR = 2.84; 95% CI: 1.27–6.34) were associated with adequate retention in care. Involvement with an HIV-related organization was associated negatively with retention in care (AOR = 0.47; 95% CI: 0.24–0.95). Future interventions should increase health insurance coverage and utilize the Internet to help MSM and waria to remain in HIV-related care, thereby assisting them in achieving viral suppression. PMID:29342172

Accuracy of endoscopic ultrasonography for diagnosing ulcerative early gastric cancers

Science.gov (United States)

Park, Jin-Seok; Kim, Hyungkil; Bang, Byongwook; Kwon, Kyesook; Shin, Youngwoon

2016-01-01

Abstract Although endoscopic ultrasonography (EUS) is the first-choice imaging modality for predicting the invasion depth of early gastric cancer (EGC), the prediction accuracy of EUS is significantly decreased when EGC is combined with ulceration. The aim of present study was to compare the accuracy of EUS and conventional endoscopy (CE) for determining the depth of EGC. In addition, the various clinic-pathologic factors affecting the diagnostic accuracy of EUS, with a particular focus on endoscopic ulcer shapes, were evaluated. We retrospectively reviewed data from 236 consecutive patients with ulcerative EGC. All patients underwent EUS for estimating tumor invasion depth, followed by either curative surgery or endoscopic treatment. The diagnostic accuracy of EUS and CE was evaluated by comparing the final histologic result of resected specimen. The correlation between accuracy of EUS and characteristics of EGC (tumor size, histology, location in stomach, tumor invasion depth, and endoscopic ulcer shapes) was analyzed. Endoscopic ulcer shapes were classified into 3 groups: definite ulcer, superficial ulcer, and ill-defined ulcer. The overall accuracy of EUS and CE for predicting the invasion depth in ulcerative EGC was 68.6% and 55.5%, respectively. Of the 236 patients, 36 patients were classified as definite ulcers, 98 were superficial ulcers, and 102 were ill-defined ulcers, In univariate analysis, EUS accuracy was associated with invasion depth (P = 0.023), tumor size (P = 0.034), and endoscopic ulcer shapes (P = 0.001). In multivariate analysis, there is a significant association between superficial ulcer in CE and EUS accuracy (odds ratio: 2.977; 95% confidence interval: 1.255–7.064; P = 0.013). The accuracy of EUS for determining tumor invasion depth in ulcerative EGC was superior to that of CE. In addition, ulcer shape was an important factor that affected EUS accuracy. PMID:27472672

CLSI-based transference of CALIPER pediatric reference intervals to Beckman Coulter AU biochemical assays.

Science.gov (United States)

Abou El Hassan, Mohamed; Stoianov, Alexandra; Araújo, Petra A T; Sadeghieh, Tara; Chan, Man Khun; Chen, Yunqi; Randell, Edward; Nieuwesteeg, Michelle; Adeli, Khosrow

2015-11-01

The CALIPER program has established a comprehensive database of pediatric reference intervals using largely the Abbott ARCHITECT biochemical assays. To expand clinical application of CALIPER reference standards, the present study is aimed at transferring CALIPER reference intervals from the Abbott ARCHITECT to Beckman Coulter AU assays. Transference of CALIPER reference intervals was performed based on the CLSI guidelines C28-A3 and EP9-A2. The new reference intervals were directly verified using up to 100 reference samples from the healthy CALIPER cohort. We found a strong correlation between Abbott ARCHITECT and Beckman Coulter AU biochemical assays, allowing the transference of the vast majority (94%; 30 out of 32 assays) of CALIPER reference intervals previously established using Abbott assays. Transferred reference intervals were, in general, similar to previously published CALIPER reference intervals, with some exceptions. Most of the transferred reference intervals were sex-specific and were verified using healthy reference samples from the CALIPER biobank based on CLSI criteria. It is important to note that the comparisons performed between the Abbott and Beckman Coulter assays make no assumptions as to assay accuracy or which system is more correct/accurate. The majority of CALIPER reference intervals were transferrable to Beckman Coulter AU assays, allowing the establishment of a new database of pediatric reference intervals. This further expands the utility of the CALIPER database to clinical laboratories using the AU assays; however, each laboratory should validate these intervals for their analytical platform and local population as recommended by the CLSI. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Thermodynamic-based retention time predictions of endogenous steroids in comprehensive two-dimensional gas chromatography.

Science.gov (United States)

Silva, Aline C A; Ebrahimi-Najafadabi, Heshmatollah; McGinitie, Teague M; Casilli, Alessandro; Pereira, Henrique M G; Aquino Neto, Francisco R; Harynuk, James J

2015-05-01

This work evaluates the application of a thermodynamic model to comprehensive two-dimensional gas chromatography (GC × GC) coupled with time-of-flight mass spectrometry for anabolic agent investigation. Doping control deals with hundreds of drugs that are prohibited in sports. Drug discovery in biological matrices is a challenging task that requires powerful tools when one is faced with the rapidly changing designer drug landscape. In this work, a thermodynamic model developed for the prediction of both primary and secondary retention times in GC × GC has been applied to trimethylsilylated hydroxyl (O-TMS)- and methoxime-trimethylsilylated carbonyl (MO-TMS)-derivatized endogenous steroids. This model was previously demonstrated on a pneumatically modulated GC × GC system, and is applied for the first time to a thermally modulated GC × GC system. Preliminary one-dimensional experiments allowed the calculation of thermodynamic parameters (ΔH, ΔS, and ΔC p ) which were successfully applied for the prediction of the analytes' interactions with the stationary phases of both the first-dimension column and the second-dimension column. The model was able to predict both first-dimension and second-dimension retention times with high accuracy compared with the GC × GC experimental measurements. Maximum differences of -8.22 s in the first dimension and 0.4 s in the second dimension were encountered for the O-TMS derivatives of 11β-hydroxyandrosterone and 11-ketoetiocholanolone, respectively. For the MO-TMS derivatives, the largest discrepancies were from testosterone (9.65 ) for the first-dimension retention times and 11-keto-etiocholanolone (0.4 s) for the second-dimension retention times.

A Study on Employee Retention Techniques

OpenAIRE

Savarimuthu, Dr. A; Hemalatha, N.

2013-01-01

The objective of perusing this study is to assess the level of satisfaction of employee retention techniques at GB Engineering Enterprises PVT Limited., Trichy.This study gains significance because of employee retention techniques can be approached from various angles. It is desirable state of existence involving retention strategies generally fall in to one of four categories salary, working conditions, job enrichment and education. These four elements together constitute. The structure of e...

Diagnostic accuracy of sonography for pleural effusion: systematic review

Directory of Open Access Journals (Sweden)

Alexandre Grimberg

Full Text Available CONTEXT AND OBJECTIVE: The initial method for evaluating the presence of pleural effusion was chest radiography. Isolated studies have shown that sonography has greater accuracy than radiography for this diagnosis; however, no systematic reviews on this matter are available in the literature. Thus, the aim of this study was to evaluate the accuracy of sonography in detecting pleural effusion, by means of a systematic review of the literature. DESIGN AND SETTING: This was a systematic review with meta-analysis on accuracy studies. This study was conducted in the Department of Diagnostic Imaging and in the Brazilian Cochrane Center, Discipline of Emergency Medicine and Evidence-Based Medicine, Department of Medicine, Universidade Federal de São Paulo (Unifesp, São Paulo, Brazil. METHOD: The following databases were searched: Cochrane Library, Medline, Web of Science, Embase and Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs. The references of relevant studies were also screened for additional citations of interest. Studies in which the accuracy of sonography for detecting pleural effusion was tested, with an acceptable reference standard (computed tomography or thoracic drainage, were included. RESULTS: Four studies were included. All of them showed that sonography had high sensitivity, specificity and accuracy for detecting pleural effusions. The mean sensitivity was 93% (95% confidence interval, CI: 89% to 96%, and specificity was 96% (95% CI: 95% to 98%. CONCLUSIONS: In different populations and clinical settings, sonography showed consistently high sensitivity, specificity and accuracy for detecting fluid in the pleural space.

Fission-product retention in HTGR fuels

International Nuclear Information System (INIS)

Homan, F.J.; Kania, M.J.; Tiegs, T.N.

1982-01-01

Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed

Parameter identification for structural dynamics based on interval analysis algorithm

Science.gov (United States)

Yang, Chen; Lu, Zixing; Yang, Zhenyu; Liang, Ke

2018-04-01

A parameter identification method using interval analysis algorithm for structural dynamics is presented in this paper. The proposed uncertain identification method is investigated by using central difference method and ARMA system. With the help of the fixed memory least square method and matrix inverse lemma, a set-membership identification technology is applied to obtain the best estimation of the identified parameters in a tight and accurate region. To overcome the lack of insufficient statistical description of the uncertain parameters, this paper treats uncertainties as non-probabilistic intervals. As long as we know the bounds of uncertainties, this algorithm can obtain not only the center estimations of parameters, but also the bounds of errors. To improve the efficiency of the proposed method, a time-saving algorithm is presented by recursive formula. At last, to verify the accuracy of the proposed method, two numerical examples are applied and evaluated by three identification criteria respectively.

Mobile Learning and Student Retention

Directory of Open Access Journals (Sweden)

Bharat Inder Fozdar

2007-06-01

Full Text Available Student retention in open and distance learning (ODL is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not been well researched. The main aim of our research, therefore, is to better understand and measure students’ attitudes and perceptions towards the effectiveness of mobile learning. Our hope is to determine how this technology can be optimally used to improve student retention at Bachelor of Science programmes at Indira Gandhi National Open University (IGNOU in India. For our research, we used a survey. Results of this survey clearly indicate that offering mobile learning could be one method improving retention of BSc students, by enhancing their teaching/ learning and improving the efficacy of IGNOU’s existing student support system. The biggest advantage of this technology is that it can be used anywhere, anytime. Moreover, as mobile phone usage in India explodes, it offers IGNOU easy access to a larger number of learners. This study is intended to help inform those who are seeking to adopt mobile learning systems with the aim of improving communication and enriching students’ learning experiences in their ODL institutions.

Visual-Spatial Attention Aids the Maintenance of Object Representations in Visual Working Memory

Science.gov (United States)

Williams, Melonie; Pouget, Pierre; Boucher, Leanne; Woodman, Geoffrey F.

2013-01-01

Theories have proposed that the maintenance of object representations in visual working memory is aided by a spatial rehearsal mechanism. In this study, we used two different approaches to test the hypothesis that overt and covert visual-spatial attention mechanisms contribute to the maintenance of object representations in visual working memory. First, we tracked observers’ eye movements while remembering a variable number of objects during change-detection tasks. We observed that during the blank retention interval, participants spontaneously shifted gaze to the locations that the objects had occupied in the memory array. Next, we hypothesized that if attention mechanisms contribute to the maintenance of object representations, then drawing attention away from the object locations during the retention interval would impair object memory during these change-detection tasks. Supporting this prediction, we found that attending to the fixation point in anticipation of a brief probe stimulus during the retention interval reduced change-detection accuracy even on the trials in which no probe occurred. These findings support models of working memory in which visual-spatial selection mechanisms contribute to the maintenance of object representations. PMID:23371773

Short-term memory across eye blinks.

Science.gov (United States)

Irwin, David E

2014-01-01

The effect of eye blinks on short-term memory was examined in two experiments. On each trial, participants viewed an initial display of coloured, oriented lines, then after a retention interval they viewed a test display that was either identical or different by one feature. Participants kept their eyes open throughout the retention interval on some blocks of trials, whereas on others they made a single eye blink. Accuracy was measured as a function of the number of items in the display to determine the capacity of short-term memory on blink and no-blink trials. In separate blocks of trials participants were instructed to remember colour only, orientation only, or both colour and orientation. Eye blinks reduced short-term memory capacity by approximately 0.6-0.8 items for both feature and conjunction stimuli. A third, control, experiment showed that a button press during the retention interval had no effect on short-term memory capacity, indicating that the effect of an eye blink was not due to general motoric dual-task interference. Eye blinks might instead reduce short-term memory capacity by interfering with attention-based rehearsal processes.

Retention of skills 2 years after completion of a postpartum hemorrhage simulation training program in rural Rwanda.

Science.gov (United States)

Nathan, Lisa M; Patauli, Desire; Nsabimana, Damien; Bernstein, Peter S; Rulisa, Stephen; Goffman, Dena

2016-09-01

To evaluate the long-term retention of skills gained by rural physicians who completed a postpartum hemorrhage simulation-training program. A quasi-experimental pre-post intervention study enrolled a convenience sample of generalist physicians in rural Rwanda. Participants underwent initial simulation training including pre- and post-training testing in February 2012. Simulation drills to assess skill retention were conducted in March 2014. Participants were scored based on their communication, evaluation, and management skills. Median scores and inter-quartile ranges were calculated and the Wilcoxon signed-rank sum test was used to compare the pre-training, post-training, and retention scores. Physician confidence was assessed using a survey. In total, 11 physicians were enrolled; eight were available for the 2-year skill-retention evaluation. Significant improvements were observed when comparing participants' pre-training and post-training communication (P=0.03), evaluation (P=0.05), and management (P=0.02) scores, and there were no changes between participants' post-training and 2-year communication (P>0.99), evaluation (P=0.16), and management (P=0.46) scores. There were no differences in the self-reported confidence measures across the duration of the study. Simulation training is an effective method for teaching postpartum hemorrhage-management skills to generalist physicians in rural areas and skills are retained for at least 2 years. Further studies could determine the optimal time intervals for refresher training. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

HPLC retention thermodynamics of grape and wine tannins.

Science.gov (United States)

Barak, Jennifer A; Kennedy, James A

2013-05-08

The effect of grape and wine tannin structure on retention thermodynamics under reversed-phase high-performance liquid chromatography conditions on a polystyrene divinylbenzene column was investigated. On the basis of retention response to temperature, an alternative retention factor was developed to approximate the combined temperature response of the complex, unresolvable tannin mixture. This alternative retention factor was based upon relative tannin peak areas separated by an abrupt change in solvent gradient. Using this alternative retention factor, retention thermodynamics were calculated. Van't Hoff relationships of the natural log of the alternative retention factor against temperature followed Kirchoff's relationship. An inverse quadratic equation was fit to the data, and from this the thermodynamic parameters for tannin retention were calculated. All tannin fractions exhibited exothermic, spontaneous interaction, with enthalpy-entropy compensation observed. Normalizing for tannin size, distinct tannin compositional effects on thermodynamic parameters were observed. The results of this study indicate that HPLC can be valuable for measuring the thermodynamics of tannin interaction with a hydrophobic surface and provides a potentially valuable alternative to calorimetry. Furthermore, the information gathered may provide insight into understanding red wine astringency quality.

Soil Water Retention Curve

Science.gov (United States)

Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

2016-12-01

Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

28 CFR 345.67 - Retention of benefits.

Science.gov (United States)

2010-07-01

... INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.67 Retention of benefits. (a) Job retention. Ordinarily, when an inmate is absent from the job for a significant period of time, the SOI will... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Retention of benefits. 345.67 Section 345...

Debridement, antibiotics, irrigation, and retention (DAIR) of the prosthesis after hip hemiarthroplasty infections. Does it work?

Science.gov (United States)

Kazimoglu, Cemal; Yalcin, Nadir; Onvural, Burak; Akcay, Serkan; Agus, Haluk

2015-08-01

Debridement, antibiotic, and implant retention (DAIR) is an attractive treatment modality after hip hemiarthroplasty (HA) infections. Data about the success of the procedure after acute onset infections is lacking. The aim of this study was to analyze the clinical outcome and associated risk factors. A multicenter, retrospective cohort study was designed, including 39 patients with acute onset prosthetic infection who had undergone debridement and irrigation with prosthesis retention. The primary outcome measure was infection eradication without prosthesis removal. We also analyzed how the success rate was influenced by the length of the interval between implantation of the prosthesis and the beginning of the treatment. The overall success rate was 41%. Sedimentation rate over 60 mm/h and the longer duration (2 weeks) after prosthesis implantation were found as factors negatively influencing the success rate. Our results indicated limited success to DAIR- treated patients with infected HA. The high failure rate of DAIR treatment after 2 weeks from the implantation should be taken into consideration.

Monitoring gas retention and slurry transport during the transfer of waste from Tank 241-C-106 to Tank 241-AY-102

International Nuclear Information System (INIS)

Stewart, C.W.; Erian, F.F.; Meyer, P.A.

1997-07-01

The retained gas volume can be estimated by several methods. All of these methods have significant uncertainties, but together they form a preponderance of evidence that describes the gas retention behavior of the tank. The methods are (1) an increase in nonconvective layer thickness; (2) a waste surface level rise (surface level effect [SLE] model); (3) the barometric pressure effect (BPE model); (4) direct void measurement; and (5) the consequences of the transfer process. The nonconvective layer thickness can be determined with sufficient accuracy to describe the overall waste configuration by means of temperature profiles or densitometer indications. However, the presence of a nonconvective layer does not necessarily indicate significant gas retention, and small changes in layer thickness that could quantify gas retention cannot be detected reliably with the methods available. The primary value of this measurement is in establishing the actual open-quotes fluffing factorclose quotes for thermal calculations. Surface level rise is not a useful measure of gas retention in Tank 241-C-106 (C-106) since the waste level fluctuates with regular makeup water additions. In Tank 241-AY-102 (AY-102) with the existing ventilation system it should be possible to determine the gas retention rate within 30-60% uncertainty from the surface level rise, should a significant rise be observed. The planned ventilation system upgrades in AY- 102 will greatly reduce the exhaust flow and the headspace humidity, and the evaporation rate should be significantly lower when transfers begin. This could reduce the uncertainty in gas retention rate estimates to around ± 10%

Energy Performance Certificate of building and confidence interval in assessment: An Italian case study

International Nuclear Information System (INIS)

Tronchin, Lamberto; Fabbri, Kristian

2012-01-01

The Directive 2002/91/CE introduced the Energy Performance Certificate (EPC), an energy policy tool. The aim of the EPC is to inform building buyers about the energy performance and energy costs of buildings. The EPCs represent a specific energy policy tool to orient the building sector and real-estate markets toward higher energy efficiency buildings. The effectiveness of the EPC depends on two factors: •The accuracy of energy performance evaluation made by independent experts. •The capability of the energy classification and of the scale of energy performance to control the energy index fluctuations. In this paper, the results of a case study located in Italy are shown. In this example, 162 independent technicians on energy performance of building evaluation have studied the same building. The results reveal which part of confidence intervals is dependent on software misunderstanding and that the energy classification ranges are able to tolerate the fluctuation of energy indices. The example was chosen in accordance with the legislation of the Emilia-Romagna Region on Energy Efficiency of Buildings. Following these results, some thermo-economic evaluation related to building and energy labelling are illustrated, as the EPC, which is an energy policy tool for the real-estate market and building sector to find a way to build or retrofit an energy efficiency building. - Highlights: ► Evaluation of the accuracy of energy performance of buildings in relation with the knowledge of independent experts. ► Round robin test based on 162 case studies on the confidence intervals expressed by independent experts. ► Statistical considerations between the confidence intervals expressed by independent experts and energy simulation software. ► Relation between “proper class” in energy classification of buildings and confidence intervals of independent experts.

First aid skill retention of first responders within the workplace

Directory of Open Access Journals (Sweden)

Masse Jeff

2011-02-01

Full Text Available Abstract Background Recent literature states that many necessary skills of CPR and first aid are forgotten shortly after certification. The purpose of this study was to determine the skill and knowledge decay in first aid in those who are paid to respond to emergency situations within a workplace. Methods Using a choking victim scenario, the sequence and accuracy of events were observed and recorded in 257 participants paid to act as first responders in large industrial or service industry settings. A multiple choice exam was also written to determine knowledge retention. Results First aid knowledge was higher in those who were trained at a higher level, and did not significantly decline over time. Those who had renewed their certificate one or more times performed better than those who had learned the information only once. During the choking scenario many skills were performed poorly, regardless of days since last training, such as hand placement and abdominal thrusts. Compressions following the victim becoming unconscious also showed classic signs of skill deterioration after 30 days. Conclusions As many skills deteriorate rapidly over the course of the first 90 days, changing frequency of certification is not necessarily the most obvious choice to increase retention of skill and knowledge. Alternatively, methods of regularly "refreshing" a skill should be explored that could be delivered at a high frequency - such as every 90 days.

International perspectives on retention and persistence

Directory of Open Access Journals (Sweden)

Gary Burkholder

2014-06-01

Full Text Available Access to higher education globally is increasing dramatically; attainment of tertiary degrees is a high priority, as educational attainment is associated with increased personal incomes as well as growth of the middle class in developing countries. The purpose of this essay is to briefly examine retention and persistence issues from a global perspective, review some retention strategies that have been employed at schools outside the United States, and to identify several key factors that related to retention and persistence globally, including access, infrastructure, financial consideration, and readiness for tertiary education.  There exists an opportunity to utilize knowledge gained in the evolution of the higher education system in the United States to help address the problems associated with retention and persistence.   DOI: 10.18870/hlrc.v4i2.208

Forensic use of the Greulich and Pyle atlas: prediction intervals and relevance

Energy Technology Data Exchange (ETDEWEB)

Chaumoitre, K.; Panuel, M. [APHM, Hopital Nord, Department of Medical Imaging, Marseille (France); Faculte de Medecine de Marseille, UMR 7268 ADES, Aix-Marseille Universite-EFS-CNRS, Marseille Cedex 15 (France); Saliba-Serre, B.; Adalian, P.; Signoli, M.; Leonetti, G. [Faculte de Medecine de Marseille, UMR 7268 ADES, Aix-Marseille Universite-EFS-CNRS, Marseille Cedex 15 (France)

2017-03-15

The Greulich and Pyle (GP) atlas is one of the most frequently used methods of bone age (BA) estimation. Our aim is to assess its accuracy and to calculate the prediction intervals at 95% for forensic use. The study was conducted on a multi-ethnic sample of 2614 individuals (1423 boys and 1191 girls) referred to the university hospital of Marseille (France) for simple injuries. Hand radiographs were analysed using the GP atlas. Reliability of GP atlas and agreement between BA and chronological age (CA) were assessed and prediction intervals at 95% were calculated. The repeatability was excellent and the reproducibility was good. Pearson's linear correlation coefficient between CA and BA was 0.983. The mean difference between BA and CA was -0.18 years (boys) and 0.06 years (girls). The prediction interval at 95% for CA was given for each GP category and ranged between 1.2 and more than 4.5 years. The GP atlas is a reproducible and repeatable method that is still accurate for the present population, with a high correlation between BA and CA. The prediction intervals at 95% are wide, reflecting individual variability, and should be known when the method is used in forensic cases. (orig.)

Strategies for improving employee retention.

Science.gov (United States)

Verlander, Edward G; Evans, Martin R

2007-03-28

This article proposes a solution to the perennial problem of talent retention in the clinical laboratory. It includes the presentation of 12 strategies that may be used to significantly improve institutional identity formation and establishment of the psychological contract that employees form with laboratory management. Identity formation and psychological contracting are deemed as essential in helping reduce employee turnover and increase retention. The 12 conversational strategies may be used as a set of best practices for all employees, but most importantly for new employees, and should be implemented at the critical moment when employees first join the laboratory. This time is referred to as "retention on-boarding"--the period of induction and laboratory orientation. Retention on-boarding involves a dialogue between employees and management that is focused on the psychological, practical, cultural, and political dimensions of the laboratory. It is placed in the context of the modern clinical laboratory, which is faced with employing and managing Generation X knowledge workers. Specific topics and broad content areas of those conversations are outlined.

Programming with Intervals

Science.gov (United States)

Matsakis, Nicholas D.; Gross, Thomas R.

Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.

Integration of genomic information into sport horse breeding programs for optimization of accuracy of selection.

Science.gov (United States)

Haberland, A M; König von Borstel, U; Simianer, H; König, S

2012-09-01

Reliable selection criteria are required for young riding horses to increase genetic gain by increasing accuracy of selection and decreasing generation intervals. In this study, selection strategies incorporating genomic breeding values (GEBVs) were evaluated. Relevant stages of selection in sport horse breeding programs were analyzed by applying selection index theory. Results in terms of accuracies of indices (r(TI) ) and relative selection response indicated that information on single nucleotide polymorphism (SNP) genotypes considerably increases the accuracy of breeding values estimated for young horses without own or progeny performance. In a first scenario, the correlation between the breeding value estimated from the SNP genotype and the true breeding value (= accuracy of GEBV) was fixed to a relatively low value of r(mg) = 0.5. For a low heritability trait (h(2) = 0.15), and an index for a young horse based only on information from both parents, additional genomic information doubles r(TI) from 0.27 to 0.54. Including the conventional information source 'own performance' into the before mentioned index, additional SNP information increases r(TI) by 40%. Thus, particularly with regard to traits of low heritability, genomic information can provide a tool for well-founded selection decisions early in life. In a further approach, different sources of breeding values (e.g. GEBV and estimated breeding values (EBVs) from different countries) were combined into an overall index when altering accuracies of EBVs and correlations between traits. In summary, we showed that genomic selection strategies have the potential to contribute to a substantial reduction in generation intervals in horse breeding programs.

Accuracy criteria recommended for the certification of gravimetric coal-mine-dust samplers

International Nuclear Information System (INIS)

Bowman, J.D.; Bartley, D.L.; Breuer, G.M.; Doemeny, L.J.; Murdock, D.J.

1984-07-01

Procedures for testing bias and precision of gravimetric coal-mine-dust sampling units are reviewed. Performance criteria for NIOSH certification of personal coal-mine dust samplers are considered. The NIOSH criterion is an accuracy of 25% at the 95% confidence interval. Size distributions of coal-mine-dust are discussed. Methods for determining size distributions are described. Sampling and sizing methods are considered. Cyclone parameter estimation is discussed. Bias computations for general sampling units are noted. Recommended procedures for evaluating bias and precision of gravimetric coal mine dust personal samplers are given. The authors conclude that when cyclones are operated at lower rates, the NIOSH accuracy criteria can be met

phosphorus retention data and metadata

Science.gov (United States)

phosphorus retention in wetlands data and metadataThis dataset is associated with the following publication:Lane , C., and B. Autrey. Phosphorus retention of forested and emergent marsh depressional wetlands in differing land uses in Florida, USA. Wetlands Ecology and Management. Springer Science and Business Media B.V;Formerly Kluwer Academic Publishers B.V., GERMANY, 24(1): 45-60, (2016).

A modified Wald interval for the area under the ROC curve (AUC) in diagnostic case-control studies.

Science.gov (United States)

Kottas, Martina; Kuss, Oliver; Zapf, Antonia

2014-02-19

The area under the receiver operating characteristic (ROC) curve, referred to as the AUC, is an appropriate measure for describing the overall accuracy of a diagnostic test or a biomarker in early phase trials without having to choose a threshold. There are many approaches for estimating the confidence interval for the AUC. However, all are relatively complicated to implement. Furthermore, many approaches perform poorly for large AUC values or small sample sizes. The AUC is actually a probability. So we propose a modified Wald interval for a single proportion, which can be calculated on a pocket calculator. We performed a simulation study to compare this modified Wald interval (without and with continuity correction) with other intervals regarding coverage probability and statistical power. The main result is that the proposed modified Wald intervals maintain and exploit the type I error much better than the intervals of Agresti-Coull, Wilson, and Clopper-Pearson. The interval suggested by Bamber, the Mann-Whitney interval without transformation and also the interval of the binormal AUC are very liberal. For small sample sizes the Wald interval with continuity has a comparable coverage probability as the LT interval and higher power. For large sample sizes the results of the LT interval and of the Wald interval without continuity correction are comparable. If individual patient data is not available, but only the estimated AUC and the total sample size, the modified Wald intervals can be recommended as confidence intervals for the AUC. For small sample sizes the continuity correction should be used.

Quantitative structure-retention relationships of pesticides in reversed-phase high-performance liquid chromatography based on WHIM and GETAWAY molecular descriptors

Energy Technology Data Exchange (ETDEWEB)

D' Archivio, Angelo Antonio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)], E-mail: darchivi@univaq.it; Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio [Dipartimento di Chimica, Ingegneria Chimica e Materiali, Universita degli Studi di L' Aquila, Via Vetoio, 67010 Coppito, L' Aquila (Italy)

2008-11-03

The ability of the Weighted Holistic Invariant Molecular (WHIM) and GEometry, Topology, and Atom-Weights AssemblY (GETAWAY) descriptors to represent the effect of molecular structure on the retention of pesticides in reversed-phase high-performance liquid chromatography (RP-HPLC) is investigated. To this end, two retention data sets previously collected in water-acetonitrile mobile phase are re-examined. The first data set (data-set-1) consists of retention data of 26 neutral compounds belonging to widely used pesticide classes, collected within the mobile phase composition range 40-65% (v/v) acetonitrile. The second data set (data-set-2) describes retention of phenoxy acid herbicides and structurally related compounds (benzoic acid and phenylacetic acid derivatives), as a whole covering the pK{sub a} range 2.3-4.3, as a function of mobile phase composition, ranging between 30 and 70% (v/v) acetonitrile, and pH, ranging between 2 and 5. For each data set, the mobile phase attributes are combined with WHIM or GETAWAY descriptors into 'mixed' predictive models in order to attempt retention modelling within the whole mobile phase composition range of analytical interest. Six- or seven-dimensional multilinear models, preliminarily selected using a genetic algorithm, were improved using a multi-layer artificial neural network (ANN) learned by back propagation. ANN performance was tested on three molecules not used in the learning stage and by leave-more-out cross validation. The results reveal that while WHIM descriptors seem not adequate to model retention of solutes of data-set-1, GETAWAY descriptors provide a satisfactory retention model. On the other hand WHIM and GETAWAY descriptors applied to data-set-2 provide a similar performance, even if slightly worse as compared with the above case. Accuracy of retention modelling in these cases is comparable or slightly poorer as compared with the results previously obtained by combining quantum chemical

Quantitative structure-retention relationships of pesticides in reversed-phase high-performance liquid chromatography based on WHIM and GETAWAY molecular descriptors

International Nuclear Information System (INIS)

D'Archivio, Angelo Antonio; Maggi, Maria Anna; Mazzeo, Pietro; Ruggieri, Fabrizio

2008-01-01

The ability of the Weighted Holistic Invariant Molecular (WHIM) and GEometry, Topology, and Atom-Weights AssemblY (GETAWAY) descriptors to represent the effect of molecular structure on the retention of pesticides in reversed-phase high-performance liquid chromatography (RP-HPLC) is investigated. To this end, two retention data sets previously collected in water-acetonitrile mobile phase are re-examined. The first data set (data-set-1) consists of retention data of 26 neutral compounds belonging to widely used pesticide classes, collected within the mobile phase composition range 40-65% (v/v) acetonitrile. The second data set (data-set-2) describes retention of phenoxy acid herbicides and structurally related compounds (benzoic acid and phenylacetic acid derivatives), as a whole covering the pK a range 2.3-4.3, as a function of mobile phase composition, ranging between 30 and 70% (v/v) acetonitrile, and pH, ranging between 2 and 5. For each data set, the mobile phase attributes are combined with WHIM or GETAWAY descriptors into 'mixed' predictive models in order to attempt retention modelling within the whole mobile phase composition range of analytical interest. Six- or seven-dimensional multilinear models, preliminarily selected using a genetic algorithm, were improved using a multi-layer artificial neural network (ANN) learned by back propagation. ANN performance was tested on three molecules not used in the learning stage and by leave-more-out cross validation. The results reveal that while WHIM descriptors seem not adequate to model retention of solutes of data-set-1, GETAWAY descriptors provide a satisfactory retention model. On the other hand WHIM and GETAWAY descriptors applied to data-set-2 provide a similar performance, even if slightly worse as compared with the above case. Accuracy of retention modelling in these cases is comparable or slightly poorer as compared with the results previously obtained by combining quantum chemical descriptors or usual

Accurate prediction of retention in hydrophilic interaction chromatography by back calculation of high pressure liquid chromatography gradient profiles.

Science.gov (United States)

Wang, Nu; Boswell, Paul G

2017-10-20

Gradient retention times are difficult to project from the underlying retention factor (k) vs. solvent composition (φ) relationships. A major reason for this difficulty is that gradients produced by HPLC pumps are imperfect - gradient delay, gradient dispersion, and solvent mis-proportioning are all difficult to account for in calculations. However, we recently showed that a gradient "back-calculation" methodology can measure these imperfections and take them into account. In RPLC, when the back-calculation methodology was used, error in projected gradient retention times is as low as could be expected based on repeatability in the k vs. φ relationships. HILIC, however, presents a new challenge: the selectivity of HILIC columns drift strongly over time. Retention is repeatable in short time, but selectivity frequently drifts over the course of weeks. In this study, we set out to understand if the issue of selectivity drift can be avoid by doing our experiments quickly, and if there any other factors that make it difficult to predict gradient retention times from isocratic k vs. φ relationships when gradient imperfections are taken into account with the back-calculation methodology. While in past reports, the accuracy of retention projections was >5%, the back-calculation methodology brought our error down to ∼1%. This result was 6-43 times more accurate than projections made using ideal gradients and 3-5 times more accurate than the same retention projections made using offset gradients (i.e., gradients that only took gradient delay into account). Still, the error remained higher in our HILIC projections than in RPLC. Based on the shape of the back-calculated gradients, we suspect the higher error is a result of prominent gradient distortion caused by strong, preferential water uptake from the mobile phase into the stationary phase during the gradient - a factor our model did not properly take into account. It appears that, at least with the stationary phase

Employee retention: a customer service approach.

Science.gov (United States)

Gerson, Richard F

2002-01-01

Employee retention is a huge problem. There are staff shortages in radiology because not enough people are entering the profession; too many people are leaving the profession for retirement, higher-paying jobs or jobs with less stress; and there are not enough opportunities for career advancement. Staff shortages are exacerbated by difficulty in retaining people who enter the profession. While much work has been focused on recruitment and getting more people "in the front door," I suggest that the bulk of future efforts be focused on employee retention and "closing the back door." Employee retention must be an ongoing process, not a program. Approaches to employee retention that focus on external things, i.e., things that the company can do to or for the employee, generally are not successful. The truth is that employee retention processes must focus on what the employee gets out of the job. The process must be a benefits-based approach that helps employees answer the question, "What's in it for me?" The retention processes must be ongoing and integrated into the daily culture of the company. The best way to keep your employees is to treat them like customers. Customer service works for external customers. We treat them nicely. We work to satisfy them. We help them achieve their goals. Why not do the same for our employees? If positive customer service policies and practices can satisfy and keep external customers, why not adapt these policies and practices for employees? And, there is a service/satisfaction link between employee retention and higher levels of customer satisfaction. Customers prefer dealing with the same employees over and over again. Employee turnover destroys a customer's confidence in the company. Just like a customer does not want to have to "train and educate" a new provider, they do not want to do the same for your "revolving door" employees. So, the key is to keep employees so they in turn will help you keep your customers. Because the

Deuterium retention in molten salt electrodeposition tungsten coatings

International Nuclear Information System (INIS)

Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

2016-01-01

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Deuterium retention in molten salt electrodeposition tungsten coatings

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

2016-12-15

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Concepts for improving the accuracy of gas balance measurement at ASDEX Upgrade

Energy Technology Data Exchange (ETDEWEB)

Härtl, T., E-mail: thomas.haertl@ipp.mpg.de; Rohde, V.; Mertens, V.

2013-10-15

The ITER fusion reactor which is under construction will use a deuterium–tritium gas mixture for operation. A fraction of this fusion fuel remains inside of the machine due to various mechanisms. The evaluation of this retention in present fusion experiments is of crucial importance to estimate the expected tritium inventory in ITER which shall be limited due to safety considerations. At ASDEX Upgrade (AUG) sufficiently time-resolved measurements should take place to extrapolate from current 10 s discharges to the at least intended 400 s ones of ITER. To achieve this, a new measurement system has been designed that enables accuracy of better than one per cent.

A Cost Benefit Analysis Between the Current Naval Officer Retention Bonus Plan and the Enlisted Retention Bonus Plan

Science.gov (United States)

2016-06-01

that personnel targeted for retention had a direct ability to affect the success of the transaction and company. High potential, job function, job level...and job title rounded out the top five reasons personnel were targeted for retention . In brief, this study found that slightly more than half of...lower income may value the job security provided by service in the military, thus making retention in the military a more attractive option. 4

Do technical parameters affect the diagnostic accuracy of virtual bronchoscopy in patients with suspected airways stenosis?

International Nuclear Information System (INIS)

Jones, Catherine M.; Athanasiou, Thanos; Nair, Sujit; Aziz, Omer; Purkayastha, Sanjay; Konstantinos, Vlachos; Paraskeva, Paraskevas; Casula, Roberto; Glenville, Brian; Darzi, Ara

2005-01-01

Purpose: Virtual bronchoscopy has gained popularity over the past decade as an alternative investigation to conventional bronchoscopy in the diagnosis, grading and monitoring of airway disease. The effect of technical parameters on diagnostic outcome from virtual bronchoscopy has not been determined. This meta-analysis aims to estimate accuracy of virtual compared to conventional bronchoscopy in patients with suspected airway stenosis, and evaluate the influence of technical parameters. Materials and methods: A MEDLINE search was used to identify relevant published studies. The primary endpoint was the 'correct diagnosis' of stenotic lesions on virtual compared to conventional bronchoscopy. Secondary endpoints included the effects of the technical parameters (pitch, collimation, reconstruction interval, rendering method, and scanner type), and date of publication on the diagnostic accuracy of virtual bronchoscopy. Results: Thirteen studies containing 454 patients were identified. Meta-analysis showed good overall diagnostic performance with 85% calculated pooled sensitivity (95% CI 77-91%), 87% specificity (95% CI 81-92%) and area under the curve (AUC) of 0.947. Subgroups included collimation of 3 mm or more (AUC 0.948), pitch of 1 (AUC 0.955), surface rendering technique (AUC 0.935), and reconstruction interval of more than 1.25 mm (AUC 0.914). There was no significant difference in accuracy accounting for publication date, scanner type or any of the above variables. Weighted regression analysis confirmed none of these variables could significantly account for study heterogeneity. Conclusion: Virtual bronchoscopy performs well in the investigation of patients with suspected airway stenosis. Overall sensitivity and specificity and diagnostic odds ratio for diagnosis of airway stenosis were high. The effects of pitch, collimation, reconstruction interval, rendering technique, scanner type, and publication date on diagnostic accuracy were not significant

Accuracy improvement in the TDR-based localization of water leaks

Directory of Open Access Journals (Sweden)

Andrea Cataldo

Full Text Available A time domain reflectometry (TDR-based system for the localization of water leaks has been recently developed by the authors. This system, which employs wire-like sensing elements to be installed along the underground pipes, has proven immune to the limitations that affect the traditional, acoustic leak-detection systems.Starting from the positive results obtained thus far, in this work, an improvement of this TDR-based system is proposed. More specifically, the possibility of employing a low-cost, water-absorbing sponge to be placed around the sensing element for enhancing the accuracy in the localization of the leak is addressed.To this purpose, laboratory experiments were carried out mimicking a water leakage condition, and two sensing elements (one embedded in a sponge and one without sponge were comparatively used to identify the position of the leak through TDR measurements. Results showed that, thanks to the water retention capability of the sponge (which maintains the leaked water more localized, the sensing element embedded in the sponge leads to a higher accuracy in the evaluation of the position of the leak. Keywords: Leak localization, TDR, Time domain reflectometry, Water leaks, Underground water pipes

Promoting Special Educator Teacher Retention

OpenAIRE

Jeremy E. Vittek

2015-01-01

This article is a critical review of the literature on special education teacher attrition and retention. The research focused on journal articles from 2004 to present. The results of the study helped define special educator attrition and retention. The major themes present in the findings were job satisfaction, administrative support, induction programs, and mentoring. The literature shows a clear need for comprehensi...

Neural Network Ensemble Based Approach for 2D-Interval Prediction of Solar Photovoltaic Power

Directory of Open Access Journals (Sweden)

Mashud Rana

2016-10-01

Full Text Available Solar energy generated from PhotoVoltaic (PV systems is one of the most promising types of renewable energy. However, it is highly variable as it depends on the solar irradiance and other meteorological factors. This variability creates difficulties for the large-scale integration of PV power in the electricity grid and requires accurate forecasting of the electricity generated by PV systems. In this paper we consider 2D-interval forecasts, where the goal is to predict summary statistics for the distribution of the PV power values in a future time interval. 2D-interval forecasts have been recently introduced, and they are more suitable than point forecasts for applications where the predicted variable has a high variability. We propose a method called NNE2D that combines variable selection based on mutual information and an ensemble of neural networks, to compute 2D-interval forecasts, where the two interval boundaries are expressed in terms of percentiles. NNE2D was evaluated for univariate prediction of Australian solar PV power data for two years. The results show that it is a promising method, outperforming persistence baselines and other methods used for comparison in terms of accuracy and coverage probability.

Flocculation of retention pond water

International Nuclear Information System (INIS)

Hart, B.T.; McGregor, R.J.

1982-05-01

An integral part of the water management strategy proposed by Ranger Uranium Mining Pty. Ltd. involves the collection of runoff water in a series of retention ponds. This water will subsequently be used in the uranium milling plant or released to Magela Creek. Runoff water collected during the wet season caused a section of Magela Creek to become turbid when it was released. The eroded material causing the turbidity was very highly dispersed and showed little tendency to sediment out in the retention ponds. Results of a preliminary study to determine the feasibility of clarifying retention pond water by flocculation with alum are presented. A concentration of 30 Mg/L alum reduced turbidity from an initial 340 NTU to less than 30 NTU in four hours

Evaluation of radiographers’ mammography screen-reading accuracy in Australia

International Nuclear Information System (INIS)

Debono, Josephine C; Poulos, Ann E; Houssami, Nehmat; Turner, Robin M; Boyages, John

2015-01-01

This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes

Evaluation of radiographers’ mammography screen-reading accuracy in Australia

Energy Technology Data Exchange (ETDEWEB)

Debono, Josephine C, E-mail: josephine.debono@bci.org.au [Westmead Breast Cancer Institute, Westmead, New South Wales (Australia); Poulos, Ann E [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Houssami, Nehmat [Screening and Test Evaluation Program, School of Public Health (A27), Sydney Medical School, University of Sydney, Sydney, New South Wales (Australia); Turner, Robin M [School of Public Health and Community Medicine, University of New South Wales, Sydney, New South Wales (Australia); Boyages, John [Macquarie University Cancer Institute, Macquarie University Hospital, Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales (Australia); Westmead Breast Cancer Institute, Westmead, New South Wales (Australia)

2015-03-15

This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes.

ECG Sensor Verification System with Mean-Interval Algorithm for Handling Sport Issue

Directory of Open Access Journals (Sweden)

Kuo-Kun Tseng

2016-01-01

Full Text Available With the development of biometric verification, we proposed a new algorithm and personal mobile sensor card system for ECG verification. The proposed new mean-interval approach can identify the user quickly with high accuracy and consumes a small amount of flash memory in the microprocessor. The new framework of the mobile card system makes ECG verification become a feasible application to overcome the issues of a centralized database. For a fair and comprehensive evaluation, the experimental results have been tested on public MIT-BIH ECG databases and our circuit system; they confirm that the proposed scheme is able to provide excellent accuracy and low complexity. Moreover, we also proposed a multiple-state solution to handle the heat rate changes of sports problem. It should be the first to address the issue of sports in ECG verification.

Nitrogen Saturation in Highly Retentive Watersheds?

Science.gov (United States)

Daley, M. L.; McDowell, W. H.

2009-12-01

Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

Difference equation model for isothermal gas chromatography expresses retention behavior of homologues of n-alkanes excluding the influence of holdup time

Science.gov (United States)

Wu, Liejun; Chen, Yongli; Caccamise, Sarah A.L.; Li, Qing X.

2012-01-01

A difference equation (DE) model is developed using the methylene retention increment (Δtz) of n-alkanes to avoid the influence of gas holdup time (tM). The effects of the equation orders (1st–5th) on the accuracy of a curve fitting show that a linear equation (LE) is less satisfactory and it is not necessary to use a complicated cubic or higher order equation. The relationship between the logarithm of Δtz and the carbon number (z) of the n-alkanes under isothermal conditions closely follows the quadratic equation for C3–C30 n-alkanes at column temperatures of 24–260 °C. The first and second order forward differences of the expression (Δlog Δtz and Δ2log Δtz, respectively) are linear and constant, respectively, which validates the DE model. This DE model lays a necessary foundation for further developing a retention model to accurately describe the relationship between the adjusted retention time and z of n-alkanes. PMID:22939376

Impact of tamsulosin on urinary retention following early catheter removal after robot-assisted laparoscopic radical prostatectomy: a prospective randomized controlled trial.

Science.gov (United States)

Jeong, In Gab; You, Dalsan; Yoon, Jong Hyun; Hong, Sungwoo; Lim, Ju Hyun; Hong, Jun Hyuk; Choo, Myung-Soo; Ahn, Hanjong; Kim, Choung-Soo

2014-02-01

To examine the impact of tamsulosin on the rate of acute urinary retention following early catheter removal after robot-assisted laparoscopic radical prostatectomy. A total of 236 patients who underwent robot-assisted laparoscopic radical prostatectomy for prostate cancer carried out by a single surgeon were enrolled in this randomized study. Patients were randomly divided into two groups: treatment with tamsulosin (0.4 mg) from 1 day before to 14 days after surgery (tamsulosin group), or no tamsulosin treatment (control group). The urethral catheter was removed on the fifth postoperative day. The primary end-point was the acute urinary retention rate. Changes in each domain of the International Continence Society male short-form questionnaire and uroflowmetry parameters were secondary end-points. The primary end-point was assessed in 218 patients (92.4%; n = 109 in each group). It was not assessed in 18 patients because of cystographic leak from the vesicourethral anastomosis. The acute urinary retention rate was lower in the tamsulosin group (7.3%) than in the control group (17.4%, P = 0.018). Multivariate logistic regression analysis identified tamsulosin treatment and the operative experience of the surgeon as independent risk factors for acute urinary retention. Tamsulosin-treated patients had a 0.30-fold lower risk of developing acute urinary retention compared with control patients (95% confidence interval 0.12-0.76; P = 0.011). None of the International Continence Society male questionnaire domain scores showed significant changes between the groups. Perioperative treatment with tamsulosin in patients undergoing robot-assisted laparoscopic radical prostatectomy reduces the rate of acute urinary retention after early catheter removal, without aggravating urinary incontinence. © 2013 The Japanese Urological Association.

Comparison of cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium nanoparticles in tumor-bearing mice.

Science.gov (United States)

Oyewumi, Moses O; Yokel, Robert A; Jay, Michael; Coakley, Tricia; Mumper, Russell J

2004-03-24

The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium (Gd) nanoparticles. Gd is a potential agent for neutron capture therapy (NCT) of tumors. Gd nanoparticles were engineered from oil-in-water microemulsion templates. To obtain folate-coated nanoparticles, a folate ligand [folic acid chemically linked to distearoylphosphatidylethanolamine (DSPE) via a PEG spacer MW 3350] was included in nanoparticle preparations. Similarly, control nanoparticles were coated with DSPE-PEG-MW 3350 (PEG-coated). Nanoparticles were characterized based on size, size distribution, morphology, biocompatibility and tumor cell uptake. In vivo studies were carried out in KB (human nasopharyngeal carcinoma) tumor-bearing athymic mice. Biodistribution and tumor retention studies were carried out at pre-determined time intervals after injection of nanoparticles (10 mg/kg). Gd nanoparticles did not aggregate platelets or activate neutrophils. The retention of nanoparticles in the blood 8, 16 and 24 h post-injection was 60%, 13% and 11% of the injected dose (ID), respectively. A maximum Gd tumor localization of 33+/-7 microg Gd/g was achieved. Both folate-coated and PEG-coated nanoparticles had comparable tumor accumulation. However, the cell uptake and tumor retention of folate-coated nanoparticles was significantly enhanced over PEG-coated nanoparticles. Thus, the benefits of folate ligand coating were to facilitate tumor cell internalization and retention of Gd-nanoparticles in the tumor tissue. The engineered nanoparticles may have potential in tumor-targeted delivery of Gd thereby enhancing the therapeutic success of NCT.

Trading speed and accuracy by coding time: a coupled-circuit cortical model.

Directory of Open Access Journals (Sweden)

Dominic Standage

2013-04-01

Full Text Available Our actions take place in space and time, but despite the role of time in decision theory and the growing acknowledgement that the encoding of time is crucial to behaviour, few studies have considered the interactions between neural codes for objects in space and for elapsed time during perceptual decisions. The speed-accuracy trade-off (SAT provides a window into spatiotemporal interactions. Our hypothesis is that temporal coding determines the rate at which spatial evidence is integrated, controlling the SAT by gain modulation. Here, we propose that local cortical circuits are inherently suited to the relevant spatial and temporal coding. In simulations of an interval estimation task, we use a generic local-circuit model to encode time by 'climbing' activity, seen in cortex during tasks with a timing requirement. The model is a network of simulated pyramidal cells and inhibitory interneurons, connected by conductance synapses. A simple learning rule enables the network to quickly produce new interval estimates, which show signature characteristics of estimates by experimental subjects. Analysis of network dynamics formally characterizes this generic, local-circuit timing mechanism. In simulations of a perceptual decision task, we couple two such networks. Network function is determined only by spatial selectivity and NMDA receptor conductance strength; all other parameters are identical. To trade speed and accuracy, the timing network simply learns longer or shorter intervals, driving the rate of downstream decision processing by spatially non-selective input, an established form of gain modulation. Like the timing network's interval estimates, decision times show signature characteristics of those by experimental subjects. Overall, we propose, demonstrate and analyse a generic mechanism for timing, a generic mechanism for modulation of decision processing by temporal codes, and we make predictions for experimental verification.

The Retention of Female Unrestricted Line Officers

National Research Council Canada - National Science Library

Pecenco, Elena G

2005-01-01

This thesis analyzes the retention of female Naval officers, focusing on the relationship between officer selection metrics and retention beyond minimum service obligation and the effect of lateral...

12 CFR 609.945 - Records retention.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate, accessible...

Employee Retention Strategies And Organizational Performance ...

African Journals Online (AJOL)

Implication of the results for practice is that any organization that fails to put in place adequate employee retention strategies is not likely to retain competent and motivated workforce in its employment and hence experience frequent labour turnover and poor organizational performance. Keywords: Employees, Retention ...

African Retentions in Blues and Jazz.

Science.gov (United States)

Meadows, Eddie S.

1979-01-01

The perseverance of African musical characteristics among American Blacks is an historic reality. African retentions have been recorded in Black music of the antebellum period. Various African scales and rhythms permeate Black American music today as evidenced in the retentions found in blues and jazz. (RLV)

Emotional Intelligence and Nursing Student Retention

Science.gov (United States)

Wilson, Victoria Jane

2013-01-01

The study examined the constructs of a Multi-Intelligence Model of Retention with four constructs: cognitive and emotional-social intelligence, student characteristics, and environmental factors. Data were obtained from sophomore students entering two diploma, nine associate, and five baccalaureate nursing programs. One year later, retention and…

Urinary Retention

Science.gov (United States)

... 2011. [4] Mevcha A, Drake MJ. Etiology and management of urinary retention in women. Indian Journal of Urology. 2010;26(2):230–235. August ... 30 a.m. to 5 p.m. eastern time, M-F Follow Us NIH… Turning Discovery Into ... Disease Urologic Diseases Endocrine Diseases Diet & Nutrition ...

Retention of airborne particles in granular bed filters

International Nuclear Information System (INIS)

Stroem, L.

1981-01-01

A literature survey was made on theoretical models for the prediction of particle retention in sand beds. Also data on observed retention was collected from the literature. Based on this information, a semi-empirical model was compiled. Comparison of the model with published retention data shows a general agreement. (Auth.)

Error and Uncertainty in the Accuracy Assessment of Land Cover Maps

Science.gov (United States)

Sarmento, Pedro Alexandre Reis

Traditionally the accuracy assessment of land cover maps is performed through the comparison of these maps with a reference database, which is intended to represent the "real" land cover, being this comparison reported with the thematic accuracy measures through confusion matrixes. Although, these reference databases are also a representation of reality, containing errors due to the human uncertainty in the assignment of the land cover class that best characterizes a certain area, causing bias in the thematic accuracy measures that are reported to the end users of these maps. The main goal of this dissertation is to develop a methodology that allows the integration of human uncertainty present in reference databases in the accuracy assessment of land cover maps, and analyse the impacts that uncertainty may have in the thematic accuracy measures reported to the end users of land cover maps. The utility of the inclusion of human uncertainty in the accuracy assessment of land cover maps is investigated. Specifically we studied the utility of fuzzy sets theory, more precisely of fuzzy arithmetic, for a better understanding of human uncertainty associated to the elaboration of reference databases, and their impacts in the thematic accuracy measures that are derived from confusion matrixes. For this purpose linguistic values transformed in fuzzy intervals that address the uncertainty in the elaboration of reference databases were used to compute fuzzy confusion matrixes. The proposed methodology is illustrated using a case study in which the accuracy assessment of a land cover map for Continental Portugal derived from Medium Resolution Imaging Spectrometer (MERIS) is made. The obtained results demonstrate that the inclusion of human uncertainty in reference databases provides much more information about the quality of land cover maps, when compared with the traditional approach of accuracy assessment of land cover maps. None

Multi-generational imputation of single nucleotide polymorphism marker genotypes and accuracy of genomic selection.

Science.gov (United States)

Toghiani, S; Aggrey, S E; Rekaya, R

2016-07-01

Availability of high-density single nucleotide polymorphism (SNP) genotyping platforms provided unprecedented opportunities to enhance breeding programmes in livestock, poultry and plant species, and to better understand the genetic basis of complex traits. Using this genomic information, genomic breeding values (GEBVs), which are more accurate than conventional breeding values. The superiority of genomic selection is possible only when high-density SNP panels are used to track genes and QTLs affecting the trait. Unfortunately, even with the continuous decrease in genotyping costs, only a small fraction of the population has been genotyped with these high-density panels. It is often the case that a larger portion of the population is genotyped with low-density and low-cost SNP panels and then imputed to a higher density. Accuracy of SNP genotype imputation tends to be high when minimum requirements are met. Nevertheless, a certain rate of genotype imputation errors is unavoidable. Thus, it is reasonable to assume that the accuracy of GEBVs will be affected by imputation errors; especially, their cumulative effects over time. To evaluate the impact of multi-generational selection on the accuracy of SNP genotypes imputation and the reliability of resulting GEBVs, a simulation was carried out under varying updating of the reference population, distance between the reference and testing sets, and the approach used for the estimation of GEBVs. Using fixed reference populations, imputation accuracy decayed by about 0.5% per generation. In fact, after 25 generations, the accuracy was only 7% lower than the first generation. When the reference population was updated by either 1% or 5% of the top animals in the previous generations, decay of imputation accuracy was substantially reduced. These results indicate that low-density panels are useful, especially when the generational interval between reference and testing population is small. As the generational interval

Black Student Retention in Higher Education.

Science.gov (United States)

Lang, Marvel, Ed.; Ford, Clinita A., Ed.

This collection focuses on problems in the recruitment, enrollment and retention of Blacks in higher education in America. The following chapters are provided: "The Black Student Retention Problem in Higher Education: Some Introductory Perspectives" (Marvel Lang); "Early Acceptance and Institutional Linkages in a Model Program of Recruitment,…

Minority Teacher Recruitment and Retention Strategies

Science.gov (United States)

Kearney-Gissendaner, Janet E.

2010-01-01

The tools and resources in this book help school leaders seamlessly incorporate minority teacher recruitment and retention programs into current human-resources activities. With details about exemplary minority teacher recruitment and retention programs, this book also showcases strategies for how to replicate such programs in your own school or…

Chosen interval methods for solving linear interval systems with special type of matrix

Science.gov (United States)

Szyszka, Barbara

2013-10-01

The paper is devoted to chosen direct interval methods for solving linear interval systems with special type of matrix. This kind of matrix: band matrix with a parameter, from finite difference problem is obtained. Such linear systems occur while solving one dimensional wave equation (Partial Differential Equations of hyperbolic type) by using the central difference interval method of the second order. Interval methods are constructed so as the errors of method are enclosed in obtained results, therefore presented linear interval systems contain elements that determining the errors of difference method. The chosen direct algorithms have been applied for solving linear systems because they have no errors of method. All calculations were performed in floating-point interval arithmetic.

Uncertainty analysis and allocation of joint tolerances in robot manipulators based on interval analysis

International Nuclear Information System (INIS)

Wu Weidong; Rao, S.S.

2007-01-01

Many uncertain factors influence the accuracy and repeatability of robots. These factors include manufacturing and assembly tolerances and deviations in actuators and controllers. The effects of these uncertain factors must be carefully analyzed to obtain a clear insight into the manipulator performance. In order to ensure the position and orientation accuracy of a robot end effector as well as to reduce the manufacturing cost of the robot, it is necessary to quantify the influence of the uncertain factors and optimally allocate the tolerances. This involves a study of the direct and inverse kinematics of robot end effectors in the presence of uncertain factors. This paper focuses on the optimal allocation of joint tolerances with consideration of the positional and directional errors of the robot end effector and the manufacturing cost. The interval analysis is used for predicting errors in the performance of robot manipulators. The Stanford manipulator is considered for illustration. The unknown joint variables are modeled as interval parameters due to the inherent uncertainty. The cost-tolerance model is assumed to be of an exponential form during optimization. The effects of the upper bounds on the minimum cost and relative deviations of the directional and positional errors of the end effector are also studied

The loss of short-term visual representations over time: decay or temporal distinctiveness?

Science.gov (United States)

Mercer, Tom

2014-12-01

There has been much recent interest in the loss of visual short-term memories over the passage of time. According to decay theory, visual representations are gradually forgotten as time passes, reflecting a slow and steady distortion of the memory trace. However, this is controversial and decay effects can be explained in other ways. The present experiment aimed to reexamine the maintenance and loss of visual information over the short term. Decay and temporal distinctiveness models were tested using a delayed discrimination task, in which participants compared complex and novel objects over unfilled retention intervals of variable length. Experiment 1 found no significant change in the accuracy of visual memory from 2 to 6 s, but the gap separating trials reliably influenced task performance. Experiment 2 found evidence for information loss at a 10-s retention interval, but temporally separating trials restored the fidelity of visual memory, possibly because temporally isolated representations are distinct from older memory traces. In conclusion, visual representations lose accuracy at some point after 6 s, but only within temporally crowded contexts. These findings highlight the importance of temporal distinctiveness within visual short-term memory. PsycINFO Database Record (c) 2014 APA, all rights reserved.

The development of adaptive memory: Young children show enhanced retention of animacy-related information.

Science.gov (United States)

Aslan, Alp; John, Thomas

2016-12-01

Previous developmental work has indicated that animacy is a foundational ontogenetic category that is given priority already early in life. Here, we investigated whether such priority is also present in children's episodic memory, examining whether young children show enhanced retention of animacy-related information. Kindergartners and younger and older elementary school children were presented with fictitious (non)words (e.g., BULA, LAFE) paired with properties characteristic of humans (e.g., "likes music"), (nonhuman) animals (e.g., "builds nests"), and inanimate things (e.g., "has four edges") and were asked to rate the animacy status of each nonword. After a retention interval, a surprise recognition test for the nonwords was administered. We found enhanced recognition of nonwords paired with human and animal properties compared with (the same) nonwords paired with inanimate properties. The size of this animacy advantage was comparable across age groups, suggesting developmental invariance of the advantage over the age range examined (i.e., 4-11years). The results support a functional-evolutionary view on memory, suggesting that already young children's memory is "tuned" to process and retain animacy. Copyright © 2016 Elsevier Inc. All rights reserved.

Pretreatment with buthionine sulfoximine enhanced uptake and retention of BSH in brain tumor

International Nuclear Information System (INIS)

Yoshida, F.; Yamamoto, T.; Nakai, K.; Zaboronok, A.; Matsuda, M.; Akutsu, H.; Ishikawa, E.; Shirakawa, M.; Matsumura, A.

2014-01-01

To determine the influence of buthionine sulfoximine (BSO) on boron biodistribution after sulfhydryl borane (BSH) administration for boron neutron capture therapy, the effectiveness of the combination of BSO with sulfhydril- (BSH) and non-sulfhydril (B 12 H 12 and BNH 3 ) boron compounds, and the interval between BSO and BSH administration, the retention of boron in tissues have been evaluated using a 9L rat tumor model. Simultaneous administration of BSH and BSO showed significantly higher boron accumulation compared to that without BSO, however there was no difference in tissue boron level between B 12 H 12 and BNH 3 administration with BSO or without BSO. The longer interval (6 h) between BSH and BSO administration related to the highest boron concentration in the brain and subcutaneous tumors compared to shorter intervals (0.5, 3 h). Boron concentration in subcutaneous and brain tumors was maintained for 6 and 12 h after the administration of BSH following BSO pretreatment. - Highlights: • Coadministration of BSH and BSO showed higher tumor boron uptake than BSH only. • Higher boron uptake was not observed after B 12 H 12 or BNH 3 administration. • The increase in tumor boron accumulation might be related to SH-groups. • BSO injection 6 h before BSH showed further increase in tumor boron uptake. • High boron concentration maintained for 6 and 12 h after BSH with BSO administration

76 FR 34010 - Credit Risk Retention

Science.gov (United States)

2011-06-10

... 2501-AD53 Credit Risk Retention AGENCIES: Office of the Comptroller of the Currency, Treasury (OCC... credit risk retention requirements of section 15G of the Securities Exchange Act of 1934, as added by the Dodd-Frank Wall Street Reform and Consumer Protection Act (``Credit Risk NPR'' or ``proposed rule...

Cytological Punctures in the Diagnosis of Renal Tumours: A Study on Accuracy and Reproducibility

DEFF Research Database (Denmark)

Kümmerlin, Intan P E D; Smedts, Frank; ten Kate, Fiebo J W

2009-01-01

BACKGROUND: Fine needle aspiration (FNA) cytology is under consideration as an auxiliary preoperative diagnostic technique in the diagnosis of renal masses. However, reports for FNA are contradictory with regard to diagnostic accuracy and applicability. OBJECTIVE: To evaluate the diagnostic...... accuracy and reproducibility of FNA from renal masses. DESIGN: FNAs performed in-bench (hematoxylin and eosin [H&E] stains) from 66 consecutive renal tumours (58 malignant and 8 benign tumours) were presented twice with a 6-mo interval to five pathologists with little experience in renal cytology...... benignity. CONCLUSION: Despite the lack of experience in renal cytology, all pathologists showed a high diagnostic yield and good overall accuracy in distinguishing between malignant and benign tumours. Concordance in subtyping varied widely among pathologists and was reliable only for clear cell renal cell...

Postpartum Engagement in HIV Care: An Important Predictor of Long-term Retention in Care and Viral Suppression.

Science.gov (United States)

Adams, Joëlla W; Brady, Kathleen A; Michael, Yvonne L; Yehia, Baligh R; Momplaisir, Florence M

2015-12-15

Human immunodeficiency virus (HIV)-infected women are at risk of virologic failure postpartum. We evaluated factors influencing retention in care and viral suppression in postpartum HIV-infected women. We conducted a retrospective cohort analysis (2005-2011) of 695 deliveries involving 561 HIV-infected women in Philadelphia. Multivariable logistic regression evaluated factors, including maternal age, race/ethnicity, substance use, antiretroviral therapy during pregnancy, timing of HIV diagnosis, previous pregnancy with HIV, adequacy of prenatal care, and postpartum HIV care engagement (≥ 1 CD4 count or viral load [VL] test within 90 days of delivery), associated with retention in care (≥ 1 CD4 count or VL test in each 6-month interval of the period with ≥ 60 days between tests) and viral suppression (VL ≤ 200 copies/mL at the last measure in the period) at 1 and 2 years postpartum. Overall, 38% of women engaged in HIV care within 90 days postpartum; with 39% and 31% retained in care and virally suppressed, respectively, at 1 year postpartum, and 25% and 34% retained in care and virally suppressed, respectively, at 2 years postpartum. In multivariable analyses, women who engaged in HIV care within 90 days of delivery were more likely to be retained (adjusted odds ratio [AOR], 11.38; 95% confidence interval [CI], 7.74-16.68) and suppressed (AOR, 2.60 [95% CI, 1.82-3.73]) at 1 year postpartum. This association persisted in the second year postpartum for both retention (AOR, 6.19 [95% CI, 4.04-9.50]) and suppression (AOR, 1.40 [95% CI, 1.01-1.95]). The prevalence of postpartum HIV-infected women retained in care and maintaining viral suppression is low. Interventions seeking to engage women in care shortly after delivery have the potential to improve clinical outcomes. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Affairs of State and Student Retention: An Exploratory Study of the Factors that Impact Student Retention in a Politically Turbulent Region

Science.gov (United States)

Ben-Tsur, Dalia

2007-01-01

This study examines the impact of a country's security unrest on student retention. It draws on the key factors that influence retention worldwide, adopts Bourdieu's notion of cultural capital and also brings in concepts related to terrorism and security unrest traditionally absent from theories on student retention. Based on a case study carried…

Technical note: Instantaneous sampling intervals validated from continuous video observation for behavioral recording of feedlot lambs.

Science.gov (United States)

Pullin, A N; Pairis-Garcia, M D; Campbell, B J; Campler, M R; Proudfoot, K L

2017-11-01

When considering methodologies for collecting behavioral data, continuous sampling provides the most complete and accurate data set whereas instantaneous sampling can provide similar results and also increase the efficiency of data collection. However, instantaneous time intervals require validation to ensure accurate estimation of the data. Therefore, the objective of this study was to validate scan sampling intervals for lambs housed in a feedlot environment. Feeding, lying, standing, drinking, locomotion, and oral manipulation were measured on 18 crossbred lambs housed in an indoor feedlot facility for 14 h (0600-2000 h). Data from continuous sampling were compared with data from instantaneous scan sampling intervals of 5, 10, 15, and 20 min using a linear regression analysis. Three criteria determined if a time interval accurately estimated behaviors: 1) ≥ 0.90, 2) slope not statistically different from 1 ( > 0.05), and 3) intercept not statistically different from 0 ( > 0.05). Estimations for lying behavior were accurate up to 20-min intervals, whereas feeding and standing behaviors were accurate only at 5-min intervals (i.e., met all 3 regression criteria). Drinking, locomotion, and oral manipulation demonstrated poor associations () for all tested intervals. The results from this study suggest that a 5-min instantaneous sampling interval will accurately estimate lying, feeding, and standing behaviors for lambs housed in a feedlot, whereas continuous sampling is recommended for the remaining behaviors. This methodology will contribute toward the efficiency, accuracy, and transparency of future behavioral data collection in lamb behavior research.

Critical evaluation of a simple retention time predictor based on LogKow as a complementary tool in the identification of emerging contaminants in water.

Science.gov (United States)

Bade, Richard; Bijlsma, Lubertus; Sancho, Juan V; Hernández, Felix

2015-07-01

There has been great interest in environmental analytical chemistry in developing screening methods based on liquid chromatography-high resolution mass spectrometry (LC-HRMS) for emerging contaminants. Using HRMS, compound identification relies on the high mass resolving power and mass accuracy attainable by these analyzers. When dealing with wide-scope screening, retention time prediction can be a complementary tool for the identification of compounds, and can also reduce tedious data processing when several peaks appear in the extracted ion chromatograms. There are many in silico, Quantitative Structure-Retention Relationship methods available for the prediction of retention time for LC. However, most of these methods use commercial software to predict retention time based on various molecular descriptors. This paper explores the applicability and makes a critical discussion on a far simpler and cheaper approach to predict retention times by using LogKow. The predictor was based on a database of 595 compounds, their respective LogKow values and a chromatographic run time of 18min. Approximately 95% of the compounds were found within 4.0min of their actual retention times, and 70% within 2.0min. A predictor based purely on pesticides was also made, enabling 80% of these compounds to be found within 2.0min of their actual retention times. To demonstrate the utility of the predictors, they were successfully used as an additional tool in the identification of 30 commonly found emerging contaminants in water. Furthermore, a comparison was made by using different mass extraction windows to minimize the number of false positives obtained. Copyright © 2015 Elsevier B.V. All rights reserved.

High Accuracy Nonlinear Control and Estimation for Machine Tool Systems

DEFF Research Database (Denmark)

Papageorgiou, Dimitrios

Component mass production has been the backbone of industry since the second industrial revolution, and machine tools are producing parts of widely varying size and design complexity. The ever-increasing level of automation in modern manufacturing processes necessitates the use of more...... sophisticated machine tool systems that are adaptable to different workspace conditions, while at the same time being able to maintain very narrow workpiece tolerances. The main topic of this thesis is to suggest control methods that can maintain required manufacturing tolerances, despite moderate wear and tear....... The purpose is to ensure that full accuracy is maintained between service intervals and to advice when overhaul is needed. The thesis argues that quality of manufactured components is directly related to the positioning accuracy of the machine tool axes, and it shows which low level control architectures...

Study of equivalent retention among different polymer-solvent systems in thermal field-flow fractionation

International Nuclear Information System (INIS)

Kim, Won Suk; Park, Young Hun; Lee, Dai Woon; Moon, Myeong Hee; Yu, Euy Kyung

1998-01-01

An equivalent retention has been experimentally observed in thermal field-flow fractionation (ThFF) for different polymer-solvent systems. It is shown that iso-retention between two sets of polymer-solvent systems can be obtained by adjusting the temperature difference (ΔT) according to the difference in the ration of ordinary diffusion coefficient to thermal diffusion coefficient. This method uses a compensation of field strength (ΔT) in ThFFF at a fixed condition of cold wall temperature. It is applied for the calculation of molecular weight of polymers based on a calibration run of different standards obtained at an adjusted ΔT. The polymer standards used in this study are polystyrene (PS), polymethylmethacrylate (PMMA), and polytetrahydrofuran (PTHF). Three carrier solvents, tetrahydrofuran (THF), methylethylketone (MEK) and ethylacetate (ETAc) were employed. Though the accuracy in the calculation of molecular weight is dependent on the difference in the slope of log λ vs. log M which is related to Mark-Houwink constant a, it shows reasonable agreement within about 6% of relative error in molecular weight calculation for the polymer-solvent systems having similar a value

Application of Rational Second Kind Chebyshev Functions for System of Integrodifferential Equations on Semi-Infinite Intervals

Directory of Open Access Journals (Sweden)

M. Tavassoli Kajani

2012-01-01

Full Text Available Rational Chebyshev bases and Galerkin method are used to obtain the approximate solution of a system of high-order integro-differential equations on the interval [0,∞. This method is based on replacement of the unknown functions by their truncated series of rational Chebyshev expansion. Test examples are considered to show the high accuracy, simplicity, and efficiency of this method.

A Model for Freshman Engineering Retention

Science.gov (United States)

Veenstra, Cindy P.; Dey, Eric L.; Herrin, Gary D.

2009-01-01

With the current concern over the growing need for more engineers, there is an immediate need to improve freshman engineering retention. A working model for freshman engineering retention is needed. This paper proposes such a model based on Tinto's Interactionalist Theory. Emphasis in this model is placed on pre-college characteristics as…

Retention of Content Utilizing a Flipped Classroom Approach.

Science.gov (United States)

Shatto, Bobbi; LʼEcuyer, Kristine; Quinn, Jerod

The flipped classroom experience promotes retention and accountability for learning. The authors report their evaluation of a flipped classroom for accelerated second-degree nursing students during their primary medical-surgical nursing course. Standardized HESI® scores were compared between a group of students who experienced the flipped classroom and a previous group who had traditional teaching methods. Short- and long-term retention was measured using standardized exams 3 months and 12 months following the course. Results indicated that short-term retention was greater and long- term retention was significantly great in the students who were taught using flipped classroom methodology.

Mucous retention cyst of the maxillary sinus.

Science.gov (United States)

Ruprecht, A; Batniji, S; el-Neweihi, E

1986-12-01

The mucous retention cyst is not a rare phenomenon. The incidence of dental patients was determined. Of 1685 patient radiographs reviewed, 44 (2.6%) had one or more mucous retention cysts in the maxillary sinuses.

[Study on retention and stability of linear occlusal complete dentures].

Science.gov (United States)

Zhang, Ping; Xu, Jun

2003-01-01

To learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force. Static retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire. Linear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures. Linear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.

Memory for non-native language: the role of lexical processing in the retention of surface form.

Science.gov (United States)

Sampaio, Cristina; Konopka, Agnieszka E

2013-01-01

Research on memory for native language (L1) has consistently shown that retention of surface form is inferior to that of gist (e.g., Sachs, 1967). This paper investigates whether the same pattern is found in memory for non-native language (L2). We apply a model of bilingual word processing to more complex linguistic structures and predict that memory for L2 sentences ought to contain more surface information than L1 sentences. Native and non-native speakers of English were tested on a set of sentence pairs with different surface forms but the same meaning (e.g., "The bullet hit/struck the bull's eye"). Memory for these sentences was assessed with a cued recall procedure. Responses showed that native and non-native speakers did not differ in the accuracy of gist-based recall but that non-native speakers outperformed native speakers in the retention of surface form. The results suggest that L2 processing involves more intensive encoding of lexical level information than L1 processing.

Memory strength and lineup presentation moderate effects of administrator influence on mistaken identifications.

Science.gov (United States)

Zimmerman, David M; Chorn, Jacqueline Austin; Rhead, Lindsey M; Evelo, Andrew J; Kovera, Margaret Bull

2017-12-01

Administrator/witness pairs (N = 313) were randomly assigned to target-absent lineups in a 2 (Suspect/Perpetrator Similarity: High Suspect Similarity vs. Low Suspect Similarity) × 2 (Retention Interval: 30 min vs. 1 week) × 2 (Lineup Presentation: Simultaneous vs. Sequential) × 2 (Administrator Knowledge: Single-Blind vs. Double-Blind) factorial design to test whether suspect similarity and memory strength constrain interpersonal expectancy effects on eyewitness identification accuracy. Administrators who knew which lineup member was the suspect (single-blind) or who administered simultaneous lineups were more likely to emit verbal and nonverbal behaviors that suggested to the witness who the suspect was. Additionally, single-blind administrators exerted more pressure on witnesses to choose the suspect as opposed to fillers. Administrator knowledge interacted with retention interval and lineup presentation to influence mistaken identifications of innocent suspects; witnesses were more likely to mistakenly identify an innocent suspect from single-blind than double-blind lineups when witness retention intervals were long and photographs were presented simultaneously. Contrary to our predictions, suspect/perpetrator similarity did not interact with other manipulated variables to influence identification decisions. Both sequential and double-blind procedures should be used to reduce the use of suggestive behavior during lineup administration. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Influence of time of placement of investments for burnout and the type of rings being used on the casting accuracy.

Science.gov (United States)

Shah, Shabir A; Naqash, Talib Amin; Padmanabhan, T V; Subramanium; Lambodaran; Nazir, Shazana

2014-03-01

The sole objective of casting procedure is to provide a metallic duplication of missing tooth structure, with as great accuracy as possible. The ability to produce well fitting castings require strict adherence to certain fundamentals. A study was undertaken to comparatively evaluate the effect on casting accuracy by subjecting the invested wax patterns to burnout after different time intervals. The effect on casting accuracy using metal ring into a pre heated burnout furnace and using split ring was also carried. The readings obtained were tabulated and subjected to statistical analysis.

Wind Effects on Retention Time in Highway Ponds

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

2007-01-01

is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress...... with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non...

Wind Effects on Retention Time in Highway Ponds

DEFF Research Database (Denmark)

Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

2008-01-01

is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress...... with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non...

Retention and failure morphology of prefabricated posts

DEFF Research Database (Denmark)

Sahafi, Alireza; Peutzfeldt, Anne; Asmussen, Erik

2004-01-01

PURPOSE: This study evaluated the effect of cement, post material, surface treatment, and shape (1) on the retention of posts luted in the root canals of extracted human teeth and (2) on the failure morphology. MATERIALS AND METHODS: Posts of titanium alloy (ParaPost XH), glass fiber (Para...... at 37 degrees C for 7 days, retention was determined by extraction of the posts. Failure morphology of extracted posts was analyzed and quantified stereomicroscopically. RESULTS: Type of luting cement, post material, and shape of post influenced the retention and failure morphology of the posts. Because...

Urinary retention associated with herpes zoster infection.

Science.gov (United States)

Cohen, L M; Fowler, J F; Owen, L G; Callen, J P

1993-01-01

Herpes zoster infection particularly involving the sacral dermatomes has been associated with bladder and bowel dysfunction, most commonly urinary retention. We report two patients who developed acute urinary retention, one of whom also had constipation, within days of herpes zoster skin lesions of the S2-S4 dermatomes. Herpes zoster is a reversible cause of neurogenic bladder and bowel dysfunction and should be considered in a patient that presents with acute urinary retention and/or constipation. Sensory abnormalities and flaccid detrusor paralysis are most likely involved in the pathogenesis.

On interval and cyclic interval edge colorings of (3,5)-biregular graphs

DEFF Research Database (Denmark)

Casselgren, Carl Johan; Petrosyan, Petros; Toft, Bjarne

2017-01-01

A proper edge coloring f of a graph G with colors 1,2,3,…,t is called an interval coloring if the colors on the edges incident to every vertex of G form an interval of integers. The coloring f is cyclic interval if for every vertex v of G, the colors on the edges incident to v either form an inte...

Drug Retention Times

Energy Technology Data Exchange (ETDEWEB)

Center for Human Reliability Studies

2007-05-01

The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

Determining the Chemical and Biological Availability of Zinc in Urban Stormwater Retention Ponds

Science.gov (United States)

Camponelli, K.; Casey, R.; Lev, S. M.; Landa, E. R.; Snodgrass, J.

2005-12-01

Highway runoff has the potential to negatively impact receiving systems due to transport of contaminants that accumulate on road surfaces. Metals such as copper and zinc are major components of automobile brake pads and tires, respectively. As these automobile parts are degraded, these metal containing particulates are deposited on the roadway and are washed into storm water retention ponds and surface water bodies during precipitation events. It has been estimated that 15 to 60% of the Zn in urban stormwater runoff comes from tire wear and that tire wear is a significant source of Zn to the environment with release inventories comparable to waste incineration sources. In urban and sub-urban systems, this large source of Zn can accumulate in stormwater retention ponds which serve as habitat for a variety of species. Understanding the chemical and biological availability of Zn to biota is integral to assessing the habitat quality of retention ponds. This study is a first effort to relate the amount and speciation of Zn in a retention pond to Zn inputs through highway-derived runoff events. In addition, results suggest that the chemical speciation and availability of particulate Zn can be related to the bioavailability and toxicity of Zn to pond organisms (i.e. larval amphibians). The study site in Owings Mills, MD is located next to a four-lane highway from which it receives runoff through a single culvert. Five species of anurans are known to utilize the pond as a breeding site and Zn in amphibian tissues and retention pond sediments were highly elevated at this site in 2001 and 2002. A recent analysis of pond sediments, soils, roadway dust and storm water collected at this site suggests that roadway particulate matter transported during runoff events is the dominant source of Zn in this system. Overall, Zn and other trace metals were found to be most abundant in the clay sized faction of pond sediments and soils. The pond cores were found to have higher Zn and Cu

Promoting Special Educator Teacher Retention

Directory of Open Access Journals (Sweden)

Jeremy E. Vittek

2015-06-01

Full Text Available This article is a critical review of the literature on special education teacher attrition and retention. The research focused on journal articles from 2004 to present. The results of the study helped define special educator attrition and retention. The major themes present in the findings were job satisfaction, administrative support, induction programs, and mentoring. The literature shows a clear need for comprehensive administrative support to improve job satisfaction and the likelihood a special educator will remain in their job.

The Rectangle Target Plot: A New Approach to the Graphical Presentation of Accuracy of Systems for Self-Monitoring of Blood Glucose.

Science.gov (United States)

Stephan, Peter; Schmid, Christina; Freckmann, Guido; Pleus, Stefan; Haug, Cornelia; Müller, Peter

2015-10-09

The measurement accuracy of systems for self-monitoring of blood glucose (SMBG) is usually analyzed by a method comparison in which the analysis results are displayed using difference plots or similar graphs. However, such plots become difficult to comprehend as the number of data points displayed increases. This article introduces a new approach, the rectangle target plot (RTP), which aims to provide a simplified and comprehensible visualization of accuracy data. The RTP is based on ISO 15197 accuracy evaluations of SMBG systems. Two-sided tolerance intervals for normally distributed data are calculated for absolute and relative differences at glucose concentrations Plotting these tolerance intervals generates a rectangle whose center indicates the systematic measurement difference of the investigated system relative to the comparison method. The size of the rectangle depends on the measurement variability. The RTP provides a means of displaying measurement accuracy data in a simple and comprehensible manner. The visualization is simplified by reducing the displayed information from typically 200 data points to just 1 rectangle. Furthermore, this allows data for several systems or several lots from 1 system to be displayed clearly and concisely in a single graph. © 2015 Diabetes Technology Society.

Retention performance of green roofs in three different climate regions

Science.gov (United States)

Sims, Andrew W.; Robinson, Clare E.; Smart, Charles C.; Voogt, James A.; Hay, Geoffrey J.; Lundholm, Jeremey T.; Powers, Brandon; O'Carroll, Denis M.

2016-11-01

Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier climates were found to have greater percent cumulative stormwater retention with Calgary (67%) having significantly better percent retention than both London (48%) and Halifax (34%). However, over the same study period the green roof in London retained the greatest depth of stormwater (598 mm), followed by the green roof in Halifax (471 mm) and then Calgary (411 mm). The impact of climate was largest for medium sized storms where the antecedent moisture condition (AMC) at the beginning of a rainfall event governs retention performance. Importantly AMC was a very good predictor of stormwater retention, with similar retention at all three sites for a given AMC, emphasizing that AMC is a relevant indicator of retention performance in any climate. For large rainfall events (i.e., >45 mm) green roof average retention ranged between 16% and 29% in all cities. Overall, drier climates have superior retention due to lower AMC in the media. However, moderate and wet climates still provide substantial total volume reduction benefits.

Herpes zoster-induced acute urinary retention.

Science.gov (United States)

Addison, Ben; Harvey, Martyn

2013-06-01

Urinary retention is a common acute presentation for men in their later decades. Potential contributing pathologies are numerous. We report an unusual case of acute urinary retention requiring catheterisation secondary to sacral herpes zoster reactivation (S2-4) in an 88-year-old man with minimal preceding obstructive symptoms. © 2013 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

[Nonparametric method of estimating survival functions containing right-censored and interval-censored data].

Science.gov (United States)

Xu, Yonghong; Gao, Xiaohuan; Wang, Zhengxi

2014-04-01

Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This pro vides some help to the medical survival data analysis.

Accuracy of different thresholds for the anti-HIV avidity index

Directory of Open Access Journals (Sweden)

Claudio Galli

2008-03-01

Full Text Available Surveillance programs for human immunodeficiency virus (HIV infection are based on the reporting of newly diagnosed cases. In order to guarantee a more accurate estimate of the trends and behaviours of infected people, simple and reliable methods aimed at identifying recent (< 6 months HIV infections are needed. We evaluated the accuracy of the avidity index (AI of anti-HIV antibodies on 357 serum samples obtained from 127 subjects for whom an estimated date of seroconversion was calculated on the basis of the interval between the last negative and first positive anti-HIV test result.The ROC curve analysis performed at different thresholds of the AI showed that a cutoff of 0.80 (93.0% sensitivity and 98.5% specificity yields the best overall accuracy (95.8% and should be employed for surveillance purposes, whereas the application of the anti-HIV AI on individual cases is not recommended.

The effect of pouring time on the dimensional accuracy of casts made from different irreversible hydrocolloid impression materials

Directory of Open Access Journals (Sweden)

Supneet Singh Wadhwa

2013-01-01

Full Text Available Aims and Objectives: To determine the time dependent accuracy of casts made from three different irreversible hydrocolloids. Materials and Methods: The effect of delayed pouring on the accuracy of three different irreversible hydrocolloid impression materials - Regular set CA 37(Cavex, The Netherlands, regular set chromatic (Jeltrate, Dentsply, and fast set (Hydrogum soft, Zhermack Clinical was investigated. A brass master die that contained two identical posts simulating two complete crown-tapered abutment preparations with reference grooves served as a standardized master model. A total of 120 impressions were made using specially prepared stock-perforated brass tray with 40 impressions of each material. The impressions were further sub-grouped according to four different storage time intervals: 0 min (immediately, 12 min, 30 min, and 1 h. The impressions were stored at room temperature in a zip-lock plastic bag. Interabutment and intraabutment distances were measured in the recovered stone dies (Type IV, Kalrock using a profile projector with an accuracy of 0.001 mm. The data so obtained was analyzed statistically. Results: Results of this study showed no statistically significant differences in the accuracy of casts obtained at different time intervals. Conclusion: Because it is not always possible to pour the impression immediately in routine clinical practice, all irreversible hydrocolloid materials studied could be stored in a zip-lock plastic bag for upto 1 h without any significant distortion.

Circadian profile of QT interval and QT interval variability in 172 healthy volunteers

DEFF Research Database (Denmark)

Bonnemeier, Hendrik; Wiegand, Uwe K H; Braasch, Wiebke

2003-01-01

of sleep. QT and R-R intervals revealed a characteristic day-night-pattern. Diurnal profiles of QT interval variability exhibited a significant increase in the morning hours (6-9 AM; P ... lower at day- and nighttime. Aging was associated with an increase of QT interval mainly at daytime and a significant shift of the T wave apex towards the end of the T wave. The circadian profile of ventricular repolarization is strongly related to the mean R-R interval, however, there are significant...

Visual working memory load-related changes in neural activity and functional connectivity.

Directory of Open Access Journals (Sweden)

Ling Li

Full Text Available BACKGROUND: Visual working memory (VWM helps us store visual information to prepare for subsequent behavior. The neuronal mechanisms for sustaining coherent visual information and the mechanisms for limited VWM capacity have remained uncharacterized. Although numerous studies have utilized behavioral accuracy, neural activity, and connectivity to explore the mechanism of VWM retention, little is known about the load-related changes in functional connectivity for hemi-field VWM retention. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we recorded electroencephalography (EEG from 14 normal young adults while they performed a bilateral visual field memory task. Subjects had more rapid and accurate responses to the left visual field (LVF memory condition. The difference in mean amplitude between the ipsilateral and contralateral event-related potential (ERP at parietal-occipital electrodes in retention interval period was obtained with six different memory loads. Functional connectivity between 128 scalp regions was measured by EEG phase synchronization in the theta- (4-8 Hz, alpha- (8-12 Hz, beta- (12-32 Hz, and gamma- (32-40 Hz frequency bands. The resulting matrices were converted to graphs, and mean degree, clustering coefficient and shortest path length was computed as a function of memory load. The results showed that brain networks of theta-, alpha-, beta-, and gamma- frequency bands were load-dependent and visual-field dependent. The networks of theta- and alpha- bands phase synchrony were most predominant in retention period for right visual field (RVF WM than for LVF WM. Furthermore, only for RVF memory condition, brain network density of theta-band during the retention interval were linked to the delay of behavior reaction time, and the topological property of alpha-band network was negative correlation with behavior accuracy. CONCLUSIONS/SIGNIFICANCE: We suggest that the differences in theta- and alpha- bands between LVF and RVF

Visual Working Memory Load-Related Changes in Neural Activity and Functional Connectivity

Science.gov (United States)

Li, Ling; Zhang, Jin-Xiang; Jiang, Tao

2011-01-01

Background Visual working memory (VWM) helps us store visual information to prepare for subsequent behavior. The neuronal mechanisms for sustaining coherent visual information and the mechanisms for limited VWM capacity have remained uncharacterized. Although numerous studies have utilized behavioral accuracy, neural activity, and connectivity to explore the mechanism of VWM retention, little is known about the load-related changes in functional connectivity for hemi-field VWM retention. Methodology/Principal Findings In this study, we recorded electroencephalography (EEG) from 14 normal young adults while they performed a bilateral visual field memory task. Subjects had more rapid and accurate responses to the left visual field (LVF) memory condition. The difference in mean amplitude between the ipsilateral and contralateral event-related potential (ERP) at parietal-occipital electrodes in retention interval period was obtained with six different memory loads. Functional connectivity between 128 scalp regions was measured by EEG phase synchronization in the theta- (4–8 Hz), alpha- (8–12 Hz), beta- (12–32 Hz), and gamma- (32–40 Hz) frequency bands. The resulting matrices were converted to graphs, and mean degree, clustering coefficient and shortest path length was computed as a function of memory load. The results showed that brain networks of theta-, alpha-, beta-, and gamma- frequency bands were load-dependent and visual-field dependent. The networks of theta- and alpha- bands phase synchrony were most predominant in retention period for right visual field (RVF) WM than for LVF WM. Furthermore, only for RVF memory condition, brain network density of theta-band during the retention interval were linked to the delay of behavior reaction time, and the topological property of alpha-band network was negative correlation with behavior accuracy. Conclusions/Significance We suggest that the differences in theta- and alpha- bands between LVF and RVF conditions in

Effects of accuracy motivation and anchoring on metacomprehension judgment and accuracy.

Science.gov (United States)

Zhao, Qin

2012-01-01

The current research investigates how accuracy motivation impacts anchoring and adjustment in metacomprehension judgment and how accuracy motivation and anchoring affect metacomprehension accuracy. Participants were randomly assigned to one of six conditions produced by the between-subjects factorial design involving accuracy motivation (incentive or no) and peer performance anchor (95%, 55%, or no). Two studies showed that accuracy motivation did not impact anchoring bias, but the adjustment-from-anchor process occurred. Accuracy incentive increased anchor-judgment gap for the 95% anchor but not for the 55% anchor, which induced less certainty about the direction of adjustment. The findings offer support to the integrative theory of anchoring. Additionally, the two studies revealed a "power struggle" between accuracy motivation and anchoring in influencing metacomprehension accuracy. Accuracy motivation could improve metacomprehension accuracy in spite of anchoring effect, but if anchoring effect is too strong, it could overpower the motivation effect. The implications of the findings were discussed.

Intrapuparial Development of Sarconesia Chlorogaster (Diptera: Calliphoridae) for Postmortem Interval Estimation (PMI).

Science.gov (United States)

Flissak, J C; Moura, M O

2018-02-28

Sarconesia chlorogaster (Wiedemann) (Diptera: Calliphoridae) is an endemic blow fly species of forensic importance in South America, and whose duration of pupal development is about 70% of the total immature development time. Therefore, morphological changes during this stage, if refined, may provide greater accuracy and reliability in the calculation of minimum postmortem interval. Considering the importance of this species, the main objective of this work was to identify and describe temporal intrapuparial morphological changes of S. chlorogaster. The development of S. chlorogaster reared on an artificial diet and at two constant temperatures (20 and 25ºC) was monitored. Every 8 h until the end of the pupal stage, 10 pupae were killed, fixed, and had their external morphology described and photographed. Of the 29 morphological characteristics described, 13 are potentially informative for estimating the age of S. chlorogaster. In general, body shape (presence or absence of tagmatization), general coloration, visible presence of the mouth hook (portion of the mandible), thoracic appendages, change in eye color, and bristle formation are the most useful characteristics for determining specific age. The results presented here make it possible to estimate the postmortem interval of a corpse using intrapuparial morphological characters, expanding one's ability to estimate postmortem interval.

Power cables thermal protection by interval simulation of imprecise dynamical systems

Energy Technology Data Exchange (ETDEWEB)

Bontempi, G. [Universite Libre de Brussels (Belgium). Dept. d' Informatique; Vaccaro, A.; Villacci, D. [Universita del Sannio Benevento (Italy). Dept. of Engineering

2004-11-01

The embedding of advanced simulation techniques in power cables enables improved thermal protection because of higher accuracy, adaptiveness and. flexibility. In particular, they make possible (i) the accurate solution of differential equations describing the cables thermal dynamics and (ii) the adoption of the resulting solution in the accomplishment of dedicated protective functions. However, the use of model-based protective systems is exposed to the uncertainty affecting some model components (e.g. weather along the line route, thermophysical properties of the soil, cable parameters). When uncertainty can be described in terms of probability distribution, well-known techniques, such as Monte Carlo, are used to simulate the system behaviour. On the other hand, when the description of uncertainty in probabilistic terms is unfeasible or problematic, nonprobabilistic alternatives should be taken into consideration. This paper will discuss and compare three interval-based techniques as alternatives to probabilistic methods in the simulation of power cable dynamics. The experimental session will assess the interval-based approaches by simulating the thermal behaviour of medium voltage power cables.(author)

Receipt of special education services following elementary school grade retention.

Science.gov (United States)

Silverstein, Michael; Guppy, Nicole; Young, Robin; Augustyn, Marilyn

2009-06-01

To estimate the proportion of children who receive an Individualized Education Program (IEP) following grade retention in elementary school. Longitudinal cohort study. Children retained in kindergarten or first (K/1) grade and third grade, presumably for academic reasons, were followed up through fifth grade. Presence or absence of an IEP. A total of 300 children retained in K/1 and 80 retained in third grade were included in the study. Of the K/1 retainees, 68.9% never received an IEP during the subsequent 4 to 5 years; of the third-grade retainees, 72.3% never received an IEP. Kindergarten/first-grade retainees in the highest quintile for socioeconomic status and those with suburban residence were less likely to receive an IEP than retained children in all other socioeconomic status quintiles (adjusted odds ratio, 0.17; 95% confidence interval, 0.05-0.62) and in rural communities (0.16; 0.06-0.44). Among K/1 retainees with persistently low academic achievement in math and reading, as assessed by standardized testing, 38.2% and 29.7%, respectively, never received an IEP. Most children retained in K/1 or third grade for academic reasons, including many of those who demonstrated sustained academic difficulties, never received an IEP during elementary school. Further studies are important to elucidate whether retained elementary schoolchildren are being denied their rights to special education services. In the meantime, early-grade retention may provide an opportunity for pediatricians to help families advocate for appropriate special education evaluations for children experiencing school difficulties.

Nuclear reactor melt-retention structure to mitigate direct containment heating

Science.gov (United States)

Tutu, Narinder K.; Ginsberg, Theodore; Klages, John R.

1991-01-01

A light water nuclear reactor melt-retention structure to mitigate the extent of direct containment heating of the reactor containment building. The structure includes a retention chamber for retaining molten core material away from the upper regions of the reactor containment building when a severe accident causes the bottom of the pressure vessel of the reactor to fail and discharge such molten material under high pressure through the reactor cavity into the retention chamber. In combination with the melt-retention chamber there is provided a passageway that includes molten core droplet deflector vanes and has gas vent means in its upper surface, which means are operable to deflect molten core droplets into the retention chamber while allowing high pressure steam and gases to be vented into the upper regions of the containment building. A plurality of platforms are mounted within the passageway and the melt-retention structure to direct the flow of molten core material and help retain it within the melt-retention chamber. In addition, ribs are mounted at spaced positions on the floor of the melt-retention chamber, and grid means are positioned at the entrance side of the retention chamber. The grid means develop gas back pressure that helps separate the molten core droplets from discharged high pressure steam and gases, thereby forcing the steam and gases to vent into the upper regions of the reactor containment building.

Measurement of the Retention Time of Different Ophthalmic Formulations with Ultrahigh-Resolution Optical Coherence Tomography.

Science.gov (United States)

Gagliano, Caterina; Papa, Vincenzo; Amato, Roberta; Malaguarnera, Giulia; Avitabile, Teresio

2018-04-01

Purpose/aim of the study: The purpose of this study was to measure the pre-corneal retention time of two marketed formulations (eye drops and eye gel) of a steroid-antibiotic fixed combination (FC) containing 0.1% dexamethasone and 0.3% netilmicin. Pre-corneal retention time was evaluated in 16 healthy subjects using an ultrahigh-resolution anterior segment spectral domain optical coherence tomography (OCT). All subjects randomly received both formulations of the FC (Netildex, SIFI, Italy). Central tear film thickness (CTFT) was measured before instillation (time 0) and then after 1, 10, 20, 30, 40 50, 60 and 120 min. The pre-corneal retention time was calculated by plotting CTFT as a function of time. Differences between time points and groups were analyzed by Student's t-test. CTFT increased significantly after the instillation of the eye gel formulation (p < 0.001). CTFT reached its maximum value 1 min after instillation and returned to baseline after 60 min. No effect on CTFT was observed after the instillation of eye drops. The difference between the two formulations was statistically significant at time 1 min (p < 0.0001), 10 min (p < 0.001) and 20 min (p < 0.01). The FC formulated as eye gel was retained on the ocular surface longer than the corresponding eye drop solution. Consequently, the use of the eye gel might extend the interval between instillations and decrease the frequency of administration.

effect of differentiated instructional strategies on students' retention

African Journals Online (AJOL)

PROF EKWUEME

show that retention ability was significantly higher in the experimental group ... Differentiated instruction, Lecture , Cognitive Achievement ,Retention ability, Geometry. ... thinking. Based on this knowledge, differentiated instruction applies an ...

The Causal Effects of Grade Retention on Behavioral Outcomes

Science.gov (United States)

Martorell, Paco; Mariano, Louis T.

2018-01-01

This study examines the impact of grade retention on behavioral outcomes under a comprehensive assessment-based student promotion policy in New York City. To isolate the causal effect of grade retention, we implement a fuzzy regression discontinuity (RD) design that exploits the fact that grade retention is largely determined by whether a student…

Relationship between potassium intake and radiocesium retention in the reindeer

International Nuclear Information System (INIS)

Holleman, D.F.; Luick, J.R.

1975-01-01

The effect of dietary potassium on radiocesium retention was studied in reindeer fed winter diets of lichens. Potassium added to the diet markedly decreased radiocesium retention; this suggests that seasonal changes in cesium retention observed earlier in reindeer might be caused largely by nutritional factors. Data indicate that a 20-fold increase in dietary potassium results in a 2-fold decrease in radiocesium retention

Record Retention Practices among the Nation's “Most Wired” Hospitals

OpenAIRE

Rinehart-Thompson, Laurie A.

2008-01-01

This exploratory study examined health record retention practices among health information management professionals in acute care general hospitals in the United States. A descriptive research design was used, and data were collected using a self-reporting survey. Respondents answered questions about record retention policies, the responsibility of health information professionals in policy administration, record retention periods, factors that determine retention periods, and other informati...

Autoshaping induces ethanol drinking in nondeprived rats: evidence of long-term retention but no induction of ethanol preference.

Science.gov (United States)

Tomie, Arthur; Kuo, Teresa; Apor, Khristine R; Salomon, Kimberly E; Pohorecky, Larissa A

2004-04-01

The effects of autoshaping procedures (paired vs. random) and sipper fluid (ethanol vs. water) on sipper-directed drinking were evaluated in male Long-Evans rats maintained with free access to food and water. For the paired/ethanol group (n=16), autoshaping procedures consisted of presenting the ethanol sipper (containing 0% to 28% unsweetened ethanol) conditioned stimulus (CS) followed by the response-independent presentation of food unconditioned stimulus (US). The random/ethanol group (n=8) received the sipper CS and food US randomly with respect to one another. The paired/water group (n=8) received only water in the sipper CS. The paired/ethanol group showed higher grams per kilogram ethanol intake than the random/ethanol group did at ethanol concentrations of 8% to 28%. The paired/ethanol group showed higher sipper CS-directed milliliter fluid consumption than the paired/water group did at ethanol concentrations of 1% to 6%, and 15%, 16%, 18%, and 20%. Following a 42-day retention interval, the paired/ethanol group showed superior retention of CS-directed drinking of 18% ethanol, relative to the random/ethanol group, and superior retention of CS-directed milliliter fluid drinking relative to the paired/water group. When tested for home cage ethanol preference using limited access two-bottle (28% ethanol vs. water) procedures, the paired/ethanol and random/ethanol groups did not differ on any drinking measures.

Studies on nitrogen retention in growing pigs

DEFF Research Database (Denmark)

Thorbek, G; Henckel, S; Chwalibog, André

1987-01-01

Nitrogen retention (RN) was measured in 60 barrows of Danish Landrace and a total of 470 balance periods was carried out during the growth period from 20 to 85 kg live weight. In the first serie (Expt A) six different feed compounds of high biological value (HBV) were fed to 48 barrows, while...... in the second serie (Expt B) 12 barrows were measured on feed compounds of HBV or low biological value (LBV). Three different levels of gross energy were used in Expt B. Individual differences of 10-20% in the pigs capability for nitrogen retention were observed. Nitrogen retention increased from 12 to 21 g N....../d on the HBV-compounds and was not influenced by increasing nitrogen or energy intake. Nitrogen retention was curvilinear in relation to metabolic live weight (kg0.75) in both series. A parabolic function on kg0.75 gave the best fit to the data with the following regression equations: Expt A + B: RN, g/d = 1...

The Association Between Health Program Participation and Employee Retention.

Science.gov (United States)

Mitchell, Rebecca J; Ozminkowski, Ronald J; Hartley, Stephen K

2016-09-01

Using health plan membership as a proxy for employee retention, the objective of this study was to examine whether use of health promotion programs was associated with employee retention. Propensity score weighted generalized linear regression models were used to estimate the association between telephonic programs or health risk surveys and retention. Analyses were conducted with six study samples based on type of program participation. Retention rates were highest for employees with either telephonic program activity or health risk surveys and lowest for employees who did not participate in any interventions. Participants ranged from 71% more likely to 5% less likely to remain with their employers compared with nonparticipants, depending on the sample used in analyses. Using health promotion programs in combination with health risk surveys may lead to improvements in employee retention.

Gatherings as a retention strategy.

Science.gov (United States)

Stokes, Lillian Gatlin

2003-01-01

Retention has long been an issue for minority students enrolled in nursing programs. Indiana University put into place an initiative to enhance retention. The initiative is "Gatherings" which provide a means for maintaining contact and direct communication with minority/international students. Gatherings allow students at varied levels in the program to interact with each other and to share issues and concerns. Over a five-year period, the benefits of this initiative have been voiced by students. These students have strongly encouraged continuation of "gatherings". Plans are underway to start similar sessions for all students.

Mentoring--a staff retention tool.

Science.gov (United States)

Kanaskie, Mary Louise

2006-01-01

Staff retention presents a common challenge for hospitals nationwide. Mentorship programs have been explored as one method of creating environments that promote staff retention. Successful achievement of nurse competencies identified in the Synergy Model for Patient Care can best be achieved in an environment that encourages and facilitates mentoring. Mentoring relationships in critical care provide the ongoing interactions, coaching, teaching, and role modeling to facilitate nurses' progression along this continuum. Mentoring relationships offer support and professional development for nurses at all levels within an organization as well as an optimistic outlook for the nursing profession.

Mechanistic failure mode investigation and resolution of parvovirus retentive filters.

Science.gov (United States)

LaCasse, Daniel; Lute, Scott; Fiadeiro, Marcus; Basha, Jonida; Stork, Matthew; Brorson, Kurt; Godavarti, Ranga; Gallo, Chris

2016-07-08

Virus retentive filters are a key product safety measure for biopharmaceuticals. A simplistic perception is that they function solely based on a size-based particle removal mechanism of mechanical sieving and retention of particles based on their hydrodynamic size. Recent observations have revealed a more nuanced picture, indicating that changes in viral particle retention can result from process pressure and/or flow interruptions. In this study, a mechanistic investigation was performed to help identify a potential mechanism leading to the reported reduced particle retention in small virus filters. Permeate flow rate or permeate driving force were varied and analyzed for their impact on particle retention in three commercially available small virus retentive filters. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:959-970, 2016. © 2016 American Institute of Chemical Engineers.

Neutral particle retention in the JET MK I divertor

International Nuclear Information System (INIS)

Ehrenberg, J.K.; Campbell, D.J.; Harbour, P.J.; Horton, L.D.; Loarte, A.; McCormick, G.K.; Monk, R.D.; Saibene, G.R.; Simonini, R.; Taroni, A.; Stamp, M.F.

1997-01-01

Retention of neutral deuterium and nitrogen in the JET MK I divertor has been investigated. Results show that ohmic plasma detachment reduces deuterium retention, that the magnetic divertor configuration has some influence on the achievable deuterium retention, and that nitrogen in nitrogen-seeded steady state detached H-mode discharges accumulates in the divertor. (orig.)

Supervised Classification High-Resolution Remote-Sensing Image Based on Interval Type-2 Fuzzy Membership Function

Directory of Open Access Journals (Sweden)

Chunyan Wang

2018-05-01

Full Text Available Because of the degradation of classification accuracy that is caused by the uncertainty of pixel class and classification decisions of high-resolution remote-sensing images, we proposed a supervised classification method that is based on an interval type-2 fuzzy membership function for high-resolution remote-sensing images. We analyze the data features of a high-resolution remote-sensing image and construct a type-1 membership function model in a homogenous region by supervised sampling in order to characterize the uncertainty of the pixel class. On the basis of the fuzzy membership function model in the homogeneous region and in accordance with the 3σ criterion of normal distribution, we proposed a method for modeling three types of interval type-2 membership functions and analyze the different types of functions to improve the uncertainty of pixel class expressed by the type-1 fuzzy membership function and to enhance the accuracy of classification decision. According to the principle that importance will increase with a decrease in the distance between the original, upper, and lower fuzzy membership of the training data and the corresponding frequency value in the histogram, we use the weighted average sum of three types of fuzzy membership as the new fuzzy membership of the pixel to be classified and then integrated into the neighborhood pixel relations, constructing a classification decision model. We use the proposed method to classify real high-resolution remote-sensing images and synthetic images. Additionally, we qualitatively and quantitatively evaluate the test results. The results show that a higher classification accuracy can be achieved with the proposed algorithm.

Multiresolution wavelet analysis of heartbeat intervals discriminates healthy patients from those with cardiac pathology

OpenAIRE

Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

1997-01-01

We applied multiresolution wavelet analysis to the sequence of times between human heartbeats (R-R intervals) and have found a scale window, between 16 and 32 heartbeats, over which the widths of the R-R wavelet coefficients fall into disjoint sets for normal and heart-failure patients. This has enabled us to correctly classify every patient in a standard data set as either belonging to the heart-failure or normal group with 100% accuracy, thereby providing a clinically significant measure of...

Estradiol enhances retention but not organization of hippocampus-dependent memory in intact male mice.

Science.gov (United States)

Al Abed, Alice Shaam; Sellami, Azza; Brayda-Bruno, Laurent; Lamothe, Valérie; Noguès, Xavier; Potier, Mylène; Bennetau-Pelissero, Catherine; Marighetto, Aline

2016-07-01

Because estrogens have mostly been studied in gonadectomized females, effects of chronic exposure to environmental estrogens in the general population are underestimated. Estrogens can enhance hippocampus-dependent memory through the modulation of information storage. However, declarative memory, the hippocampus-dependent memory of facts and events, demands more than abilities to retain information. Specifically, memory of repetitive events of everyday life such as "where I parked" requires abilities to organize/update memories to prevent proactive interference from similar memories of previous "parking events". Whether such organizational processes are estrogen-sensitive is unknown. We here studied, in intact young and aged adult mice, drinking-water (1μM) estradiol effects on both retention and organizational components of hippocampus-dependent memory, using a radial-maze task of everyday-like memory. Demand on retention vs organization was manipulated by varying the time-interval separating repetitions of similar events. Estradiol increased performance in young and aged mice under minimized organizational demand, but failed to improve the age-associated memory impairment and diminished performance in young mice under high organizational demand. In fact, estradiol prolonged mnemonic retention of successive events without improving organization abilities, hence resulted in more proactive interference from irrelevant memories. c-Fos imaging of testing-induced brain activations showed that the deterioration of young memory was associated with dentate gyrus dysconnectivity, reminiscent of that seen in aged mice. Our findings support the view that estradiol is promnesic but also reveal that such property can paradoxically impair memory. These findings have important outcomes regarding health issues relative to the impact of environmental estrogens in the general population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Suspect screening of large numbers of emerging contaminants in environmental waters using artificial neural networks for chromatographic retention time prediction and high resolution mass spectrometry data analysis.

Science.gov (United States)

Bade, Richard; Bijlsma, Lubertus; Miller, Thomas H; Barron, Leon P; Sancho, Juan Vicente; Hernández, Felix

2015-12-15

The recent development of broad-scope high resolution mass spectrometry (HRMS) screening methods has resulted in a much improved capability for new compound identification in environmental samples. However, positive identifications at the ng/L concentration level rely on analytical reference standards for chromatographic retention time (tR) and mass spectral comparisons. Chromatographic tR prediction can play a role in increasing confidence in suspect screening efforts for new compounds in the environment, especially when standards are not available, but reliable methods are lacking. The current work focuses on the development of artificial neural networks (ANNs) for tR prediction in gradient reversed-phase liquid chromatography and applied along with HRMS data to suspect screening of wastewater and environmental surface water samples. Based on a compound tR dataset of >500 compounds, an optimized 4-layer back-propagation multi-layer perceptron model enabled predictions for 85% of all compounds to within 2min of their measured tR for training (n=344) and verification (n=100) datasets. To evaluate the ANN ability for generalization to new data, the model was further tested using 100 randomly selected compounds and revealed 95% prediction accuracy within the 2-minute elution interval. Given the increasing concern on the presence of drug metabolites and other transformation products (TPs) in the aquatic environment, the model was applied along with HRMS data for preliminary identification of pharmaceutically-related compounds in real samples. Examples of compounds where reference standards were subsequently acquired and later confirmed are also presented. To our knowledge, this work presents for the first time, the successful application of an accurate retention time predictor and HRMS data-mining using the largest number of compounds to preliminarily identify new or emerging contaminants in wastewater and surface waters. Copyright © 2015 Elsevier B.V. All rights

Clinical accuracy of ExacTrac intracranial frameless stereotactic system

International Nuclear Information System (INIS)

Ackerly, T.; Lancaster, C. M.; Geso, M.; Roxby, K. J.

2011-01-01

Purpose: In this paper, the authors assess the accuracy of the Brainlab ExacTrac system for frameless intracranial stereotactic treatments in clinical practice. Methods: They recorded couch angle and image fusion results (comprising lateral, longitudinal, and vertical shifts, and rotation corrections about these axes) for 109 stereotactic radiosurgery and 166 stereotactic radiotherapy patient treatments. Frameless stereotactic treatments involve iterative 6D image fusion corrections applied until the results conform to customizable pass criteria, theirs being 0.7 mm and 0.5 deg. for each axis. The planning CT slice thickness was 1.25 mm. It has been reported in the literature that the CT slices' thickness impacts the accuracy of localization to bony anatomy. The principle of invariance with respect to patient orientation was used to determine spatial accuracy. Results: The data for radiosurgery comprised 927 image pairs, of which 532 passed (pass ratio of 57.4%). The data for radiotherapy comprised 15983 image pairs, of which 10 050 passed (pass ratio of 62.9%). For stereotactic radiotherapy, the combined uncertainty of ExacTrac calibration, image fusion, and intrafraction motion was (95% confidence interval) 0.290-0.302 and 0.306-0.319 mm in the longitudinal and lateral axes, respectively. The combined uncertainty of image fusion and intrafraction motion in the anterior-posterior coordinates was 0.174-0.182 mm. For stereotactic radiosurgery, the equivalent ranges are 0.323-0.393, 0.337-0.409, and 0.231-0.281 mm. The overall spatial accuracy was 1.24 mm for stereotactic radiotherapy (SRT) and 1.35 mm for stereotactic radiosurgery (SRS). Conclusions: The ExacTrac intracranial frameless stereotactic system spatial accuracy is adequate for clinical practice, and with the same pass criteria, SRT is more accurate than SRS. They now use frameless stereotaxy exclusively at their center.

Black carbon content in a ponderosa pine forest of eastern Oregon with varying seasons and intervals of prescribed burns

Science.gov (United States)

Matosziuk, L.; Hatten, J. A.

2016-12-01

Soil carbon represents a significant component of the global carbon cycle. While fire-based disturbance of forest ecosystems acts as a carbon source, the increased temperatures can initiate molecular changes to forest biomass that convert fast cycling organic carbon into more stable forms such as black carbon (BC), a product of incomplete combustion that contains highly-condensed aromatic structures and very low hydrogen and oxygen content. Such forms of carbon can remain in the soil for hundred to thousands of years, effectively creating a long-term carbon sink. The goal of this project is to understand how specific characteristics of prescribed burns, specifically the season of burn and the interval between burns, affect the formation, structure, and retention of these slowly degrading forms of carbon in the soil. Both O-horizon (forest floor) and mineral soil (0-15 cm cores) samples were collected from a season and interval of burn study in Malheur National Forest. The study area is divided into six replicate units, each of which is sub-divided into four treatment areas and a control. Beginning in 1997, each treatment area was subjected to: i) spring burns at five-year intervals, ii) fall burns at five-year intervals, iii) spring burns at 15-year intervals, or iv) fall burns at 15-year intervals. The bulk density, pH, and C/N content of each soil were measured to assess the effect of the burn treatments on the soil. Additionally, the amount and molecular structure of BC in each sample was quantified using the distribution of specific molecular markers (benzene polycarboxylic acids or BPCAs) that are present in the soil following acid digestion.

Radiodiagnosis of filled retention bronchial cysts and lung tuberculomes

International Nuclear Information System (INIS)

Gudz', A.E.

1987-01-01

Radiological semiotics of filled retention bronchial cysts in 23 patients and of lung tuberculomes in 52 is studied on the basis of the data on roentgenography, tomography and bronchography. Characteristic radiological signs of retention bronchial cysts and tuberculomes are determined. Significance of each radiological sign for differential diagnosis of filled retention bronchial cysts and lung tuberculomes is estimated

Postgraduation retention of medical students from Otago and Auckland medical programmes.

Science.gov (United States)

Shelker, William; Poole, Phillippa; Bagg, Warwick; Wood, Ian; Glue, Paul

2014-01-24

Auckland and Otago medical programmes have different methods for selecting students. This study compared postgraduate retention in New Zealand (NZ) of medical graduates from the two medical programmes, to assess whether different selection methods influenced retention. Other variables assessed included entrance category and age at graduation. Anonymised databases were created of all graduates from the Otago Faculty of Medicine (1999-2011) and the Auckland medical programme (2000-2012). Demographic and entry category data were recorded. Retention was defined as presence on the NZ Medical Register in December 2012. Risk differences (RD) were calculated to compare retention between the two medical programmes using the Mantel-Haenszel method. The influence of medical programme entrance category on retention was also tested. The influence of covariates on retaining graduates on the register was evaluated using a multiple logistic regression model. The postgraduate retention of graduates of the two medical programmes over 13 years was identical (Auckland 74.9%, Otago 73.6%, P=0.48). Retention of graduate and non-graduate entry students from both medical programmes was similar by 6 years after graduation. Age during medical school did not affect retention. University of attendance had no effect on postgraduation retention of students on the NZ Medical Register, suggesting that retention is not influenced by the different student selection methods at each programme. The data presented shows that New Zealand graduates regardless of programme completed show a similar profile in terms of retention.

Coherent oscillatory networks supporting short-term memory retention.

Science.gov (United States)

Payne, Lisa; Kounios, John

2009-01-09

Accumulating evidence suggests that top-down processes, reflected by frontal-midline theta-band (4-8 Hz) electroencephalogram (EEG) oscillations, strengthen the activation of a memory set during short-term memory (STM) retention. In addition, the amplitude of posterior alpha-band (8-13 Hz) oscillations during STM retention is thought to reflect a mechanism that protects fragile STM activations from interference by gating bottom-up sensory inputs. The present study addressed two important questions about these phenomena. First, why have previous studies not consistently found memory set-size effects on frontal-midline theta? Second, how does posterior alpha participate in STM retention? To answer these questions, large-scale network connectivity during STM retention was examined by computing EEG wavelet coherence during the retention period of a modified Sternberg task using visually-presented letters as stimuli. The results showed (a) increasing theta-band coherence between frontal-midline and left temporal-parietal sites with increasing memory load, and (b) increasing alpha-band coherence between midline parietal and left temporal/parietal sites with increasing memory load. These findings support the view that theta-band coherence, rather than amplitude, is the key factor in selective top-down strengthening of the memory set and demonstrate that posterior alpha-band oscillations associated with sensory gating are involved in STM retention by participating in the STM network.

Design and accuracy analysis of a metamorphic CNC flame cutting machine for ship manufacturing

Science.gov (United States)

Hu, Shenghai; Zhang, Manhui; Zhang, Baoping; Chen, Xi; Yu, Wei

2016-09-01

The current research of processing large size fabrication holes on complex spatial curved surface mainly focuses on the CNC flame cutting machines design for ship hull of ship manufacturing. However, the existing machines cannot meet the continuous cutting requirements with variable pass conditions through their fixed configuration, and cannot realize high-precision processing as the accuracy theory is not studied adequately. This paper deals with structure design and accuracy prediction technology of novel machine tools for solving the problem of continuous and high-precision cutting. The needed variable trajectory and variable pose kinematic characteristics of non-contact cutting tool are figured out and a metamorphic CNC flame cutting machine designed through metamorphic principle is presented. To analyze kinematic accuracy of the machine, models of joint clearances, manufacturing tolerances and errors in the input variables and error models considering the combined effects are derived based on screw theory after establishing ideal kinematic models. Numerical simulations, processing experiment and trajectory tracking experiment are conducted relative to an eccentric hole with bevels on cylindrical surface respectively. The results of cutting pass contour and kinematic error interval which the position error is from-0.975 mm to +0.628 mm and orientation error is from-0.01 rad to +0.01 rad indicate that the developed machine can complete cutting process continuously and effectively, and the established kinematic error models are effective although the interval is within a `large' range. It also shows the matching property between metamorphic principle and variable working tasks, and the mapping correlation between original designing parameters and kinematic errors of machines. This research develops a metamorphic CNC flame cutting machine and establishes kinematic error models for accuracy analysis of machine tools.

Use of geomorphic, hydrologic, and nitrogen mass balance data to model ecosystem nitrate retention in tidal freshwater wetlands

Directory of Open Access Journals (Sweden)

E. D. Seldomridge

2012-07-01

Full Text Available Geomorphic characteristics have been used as scaling parameters to predict water and other fluxes in many systems. In this study, we combined geomorphic analysis with in-situ mass balance studies of nitrate retention (NR to evaluate which geomorphic scaling parameters best predicted NR in a tidal freshwater wetland ecosystem. Geomorphic characteristics were measured for 267 individual marshes that constitute the freshwater tidal wetland ecosystem of the Patuxent River, Maryland. Nitrate retention was determined from mass balance measurements conducted at the inlets of marshes of varying size (671, 5705, and 536 873 m² over a period of several years. Mass balance measurements indicate that NR is proportional to total water flux over the tidal cycle. Relationships between estimated tidal prism (calculated water volume for spring tides and various geomorphic parameters (marsh area, total channel length, and inlet width were defined using measurements from air photos and compared to field data. From these data, NR equations were determined for each geomorphic parameter, and used to estimate NR for all marshes in the ecosystem for a reference spring (high tide. The resulting ecosystem NR estimates were evaluated for (a accuracy and completeness of geomorphic data, (b relationship between the geomorphic parameters and hydrologic flux, and (c the ability to adapt the geomorphic parameter to varying tidal conditions. This analysis indicated that inlet width data were the most complete and provided the best estimate of ecosystem nitrate retention. Predictions based on marsh area were significantly lower than the inlet width-based predictions. Cumulative probability distributions of nitrate retention indicate that the largest 3–4% of the marshes retained half of the total nitrate for the ecosystem.

Linking local retention, self-recruitment, and persistence in marine metapopulations

KAUST Repository

Lett, Christophe; Nguyen-Huu, Tri; Cuif, Marion; Saenz Agudelo, Pablo; Kaplan, David M.

2015-01-01

Three indices of larval retention have been used in the literature to assess the tendency for self-maintenance of local marine populations: local retention (LR), self-recruitment (SR), and relative local retention (RLR). Only one of these, LR

Evaluation of 131I retention in several adsorbers

International Nuclear Information System (INIS)

Catanoso, Marcela F.; Osso Junior, Joao Alberto

2011-01-01

Several iodine radioisotopes are used in nuclear medicine for treatment and diagnostic purposes. The radioisotope 131 I is used both in diagnosis and therapy due to its physical characteristics of decay by β - and its γ-ray emissions suitable for diagnosis. It is routinely produced at IPEN through the irradiation of TeO 2 targets in the IEA-R1m nuclear reactor. After the irradiation, the 131 I is separated by dry distillation, where the targets are put in an oven, heated at 760 deg C for 2 hours and the 131 I, volatile, is carried by an O 2 gas stream. The aim of this work was to evaluate the retention and elution of 131 I samples produced at IPEN in several adsorbers as part of a project aiming the purification of these radioisotopes, allowing the labeling of biomolecules. Samples of 131 I were used for retention and elution studies with the following adsorbers: commercial cartridges, anionic resin columns and cationic resin column. The results showed that Ag cartridges and anionic resins Dowex 1X8, Dowex 3 and IRA 400 had a great iodine retention but no elution after using specific eluents. The QMA light, acid alumina, neutral alumina and cationic resin Dowex 50WX4 showed high retention and elution and QMA plus and cationic resin Dowex 50WX8 and Dowex 50WX12 had a good retention but lower elution. Regarding to the better retention and elution, Ag cartridges and resins showed a higher percentage of iodine retention but lower elution yield and QMA light, acid and neutral alumina cartridges showed better results. (author)

Tolerance limits and tolerance intervals for ratios of normal random variables using a bootstrap calibration.

Science.gov (United States)

Flouri, Marilena; Zhai, Shuyan; Mathew, Thomas; Bebu, Ionut

2017-05-01

This paper addresses the problem of deriving one-sided tolerance limits and two-sided tolerance intervals for a ratio of two random variables that follow a bivariate normal distribution, or a lognormal/normal distribution. The methodology that is developed uses nonparametric tolerance limits based on a parametric bootstrap sample, coupled with a bootstrap calibration in order to improve accuracy. The methodology is also adopted for computing confidence limits for the median of the ratio random variable. Numerical results are reported to demonstrate the accuracy of the proposed approach. The methodology is illustrated using examples where ratio random variables are of interest: an example on the radioactivity count in reverse transcriptase assays and an example from the area of cost-effectiveness analysis in health economics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Leech method for diagnosing constipation: intra- and interobserver variability and accuracy

International Nuclear Information System (INIS)

Lorijn, Fleur de; Voskuijl, Wieger P.; Taminiau, Jan A.; Benninga, Marc A.; Rijn, Rick R. van; Henneman, Onno D.F.; Heijmans, Jarom; Reitsma, Johannes B.

2006-01-01

The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, ''the Leech method'', for assessing faecal loading. To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC). A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients. Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy. The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children. (orig.)

Plutonium fecal and urinary excretion functions: Derivation from a systematic whole-body retention function

International Nuclear Information System (INIS)

Sun, C.; Lee, D.

1999-01-01

Liver-bile secretion directly influences the content of plutonium in feces. To assess the reliability of plutonium metabolic models and to improve the accuracy of interpreting plutonium fecal data, the authors developed a compartmental model that simulates the metabolism of plutonium in humans. With this model, they can describe the transport of plutonium contaminants in the systemic organs and tissues of the body, including fecal and urine excretions, without using elaborate kinetic information. The parameter values of the models, which describe the translocation rates and recycling of plutonium in the body, can be derived from a multi-term exponential systemic function for whole-body retention. The analytical derivations and algorithms for solving translocation parameter values are established for the model and illustrated by applying them to the biokinetics and bioassay of plutonium. This study describes how to (1) design a physiological model for incorporating liver biliary secretion and for obtaining a fecal-excretion function, (2) develop an analytical solution for identifying the translocation-parameter values incorporating the recycling of plutonium in the body, and (3) derive a set of urinary and fecal excretion-functions from a published systemic whole-body retention function, generally acknowledged to be accurate, as a real and practical example

Plunger with simple retention valve

International Nuclear Information System (INIS)

Fekete, A.V.

1987-01-01

This patent describes a positive displacement retention valve apparatus in which the actual flow equals the theoretical maximum flow through the retention valve. The apparatus includes, in combination, a confined fluid flow conduit, a piston adapted for reciprocal movement within the fluid flow conduit between upstream and downstream limit positions, piston reciprocating means, and pressure responsive check valve means located upstream with respect to the piston in the fluid flow conduit. The pressure responsive check valve means operable to permit fluid flow therethrough in a downstream direction toward the piston, and to preclude fluid flow therethrough in an opposite direction. The piston is composed of parts which are relatively movable with respect to one another. The piston includes a simple retention valve consisting of a plug means, a cylinder having a minimum and a maximum internal cross section flow area therein and being reciprocal within the confined fluid flow conduit, and a seat on the cylinder for the plug means. The piston reciprocating means are operatively connected to the plug means

U.S. Marine Corps Enlisted Retention: An Analysis of Stakeholder Incentives for the Retention of Tier 1 First-Term Marines

Science.gov (United States)

2014-03-01

ERTF Enlisted Retention Task Force FFM fast filling military occupational specialty FTAP first-term alignment plan FY fiscal year GT general...Planning military ( FFM ) occupational specialties that are processed through boards to ensure the retention of highly qualified Marines. Fast-filling

Effects of high heat flux hydrogen and helium mixture beam irradiation on surface modification and hydrogen retention in tungsten materials

International Nuclear Information System (INIS)

Tokunaga, K.; Fujiwara, T.; Ezato, K.; Suzuki, S.; Akiba, M.; Kurishita, H.; Nagata, S.; Tsuchiya, B.; Tonegawa, A.; Yoshida, N.

2009-01-01

High heat flux experiments using a hydrogen-helium mixture beam have been carried out on powder metallurgy tungsten (PM-W) and ultra fine grain W-TiC alloy (W-0.5 wt%TiC-H 2 ). The energy of is 18 keV. Beam flux and heat flux at the beam center is 2.0 x 10 21 atoms/m 2 s and 7.0 MW/m 2 , respectively. Typical ratio of He/D ion is 0.25. Beam duration is 1.5-3 s and interval of beam shot start is 30 s. The samples are irradiated up to a fluence of 10 22 -10 24 He/m 2 by the repeated irradiation pulses. After the irradiation, surface modification by the irradiation and hydrogen retention, surface composition have been investigated. Surface modification by hydrogen-helium mixture beams is completely different from results of single beam irradiation. In particular, mixture beam irradiation causes remarkably high hydrogen retention.

Impaired Retention of Motor Learning of Writing Skills in Patients with Parkinson's Disease with Freezing of Gait.

Directory of Open Access Journals (Sweden)

Elke Heremans

Full Text Available Patients with Parkinson's disease (PD and freezing of gait (FOG suffer from more impaired motor and cognitive functioning than their non-freezing counterparts. This underlies an even higher need for targeted rehabilitation programs in this group. However, so far it is unclear whether FOG affects the ability for consolidation and generalization of motor learning and thus the efficacy of rehabilitation.To investigate the hallmarks of motor learning in people with FOG compared to those without by comparing the effects of an intensive motor learning program to improve handwriting.Thirty five patients with PD, including 19 without and 16 with FOG received six weeks of handwriting training consisting of exercises provided on paper and on a touch-sensitive writing tablet. Writing training was based on single- and dual-task writing and was supported by means of visual target zones. To investigate automatization, generalization and retention of learning, writing performance was assessed before and after training in the presence and absence of cues and dual tasking and after a six-week retention period. Writing amplitude was measured as primary outcome measure and variability of writing and dual-task accuracy as secondary outcomes.Significant learning effects were present on all outcome measures in both groups, both for writing under single- and dual-task conditions. However, the gains in writing amplitude were not retained after a retention period of six weeks without training in the patient group without FOG. Furthermore, patients with FOG were highly dependent on the visual target zones, reflecting reduced generalization of learning in this group.Although short-term learning effects were present in both groups, generalization and retention of motor learning were specifically impaired in patients with PD and FOG. The results of this study underscore the importance of individualized rehabilitation protocols.

Impaired Retention of Motor Learning of Writing Skills in Patients with Parkinson's Disease with Freezing of Gait.

Science.gov (United States)

Heremans, Elke; Nackaerts, Evelien; Vervoort, Griet; Broeder, Sanne; Swinnen, Stephan P; Nieuwboer, Alice

2016-01-01

Patients with Parkinson's disease (PD) and freezing of gait (FOG) suffer from more impaired motor and cognitive functioning than their non-freezing counterparts. This underlies an even higher need for targeted rehabilitation programs in this group. However, so far it is unclear whether FOG affects the ability for consolidation and generalization of motor learning and thus the efficacy of rehabilitation. To investigate the hallmarks of motor learning in people with FOG compared to those without by comparing the effects of an intensive motor learning program to improve handwriting. Thirty five patients with PD, including 19 without and 16 with FOG received six weeks of handwriting training consisting of exercises provided on paper and on a touch-sensitive writing tablet. Writing training was based on single- and dual-task writing and was supported by means of visual target zones. To investigate automatization, generalization and retention of learning, writing performance was assessed before and after training in the presence and absence of cues and dual tasking and after a six-week retention period. Writing amplitude was measured as primary outcome measure and variability of writing and dual-task accuracy as secondary outcomes. Significant learning effects were present on all outcome measures in both groups, both for writing under single- and dual-task conditions. However, the gains in writing amplitude were not retained after a retention period of six weeks without training in the patient group without FOG. Furthermore, patients with FOG were highly dependent on the visual target zones, reflecting reduced generalization of learning in this group. Although short-term learning effects were present in both groups, generalization and retention of motor learning were specifically impaired in patients with PD and FOG. The results of this study underscore the importance of individualized rehabilitation protocols.

Internal representations of temporal statistics and feedback calibrate motor-sensory interval timing.

Directory of Open Access Journals (Sweden)

Luigi Acerbi

Full Text Available Humans have been shown to adapt to the temporal statistics of timing tasks so as to optimize the accuracy of their responses, in agreement with the predictions of Bayesian integration. This suggests that they build an internal representation of both the experimentally imposed distribution of time intervals (the prior and of the error (the loss function. The responses of a Bayesian ideal observer depend crucially on these internal representations, which have only been previously studied for simple distributions. To study the nature of these representations we asked subjects to reproduce time intervals drawn from underlying temporal distributions of varying complexity, from uniform to highly skewed or bimodal while also varying the error mapping that determined the performance feedback. Interval reproduction times were affected by both the distribution and feedback, in good agreement with a performance-optimizing Bayesian observer and actor model. Bayesian model comparison highlighted that subjects were integrating the provided feedback and represented the experimental distribution with a smoothed approximation. A nonparametric reconstruction of the subjective priors from the data shows that they are generally in agreement with the true distributions up to third-order moments, but with systematically heavier tails. In particular, higher-order statistical features (kurtosis, multimodality seem much harder to acquire. Our findings suggest that humans have only minor constraints on learning lower-order statistical properties of unimodal (including peaked and skewed distributions of time intervals under the guidance of corrective feedback, and that their behavior is well explained by Bayesian decision theory.

Remote Sensing Based Two-Stage Sampling for Accuracy Assessment and Area Estimation of Land Cover Changes

Directory of Open Access Journals (Sweden)

Heinz Gallaun

2015-09-01

Full Text Available Land cover change processes are accelerating at the regional to global level. The remote sensing community has developed reliable and robust methods for wall-to-wall mapping of land cover changes; however, land cover changes often occur at rates below the mapping errors. In the current publication, we propose a cost-effective approach to complement wall-to-wall land cover change maps with a sampling approach, which is used for accuracy assessment and accurate estimation of areas undergoing land cover changes, including provision of confidence intervals. We propose a two-stage sampling approach in order to keep accuracy, efficiency, and effort of the estimations in balance. Stratification is applied in both stages in order to gain control over the sample size allocated to rare land cover change classes on the one hand and the cost constraints for very high resolution reference imagery on the other. Bootstrapping is used to complement the accuracy measures and the area estimates with confidence intervals. The area estimates and verification estimations rely on a high quality visual interpretation of the sampling units based on time series of satellite imagery. To demonstrate the cost-effective operational applicability of the approach we applied it for assessment of deforestation in an area characterized by frequent cloud cover and very low change rate in the Republic of Congo, which makes accurate deforestation monitoring particularly challenging.

Aerosol retention in the flooded steam generator bundle during SGTR

International Nuclear Information System (INIS)

Lind, Terttaliisa; Dehbi, Abdel; Guentay, Salih

2011-01-01

Research highlights: → High retention of aerosol particles in a steam generator bundle flooded with water. → Increasing particle inertia, i.e., particle size and velocity, increases retention. → Much higher retention of aerosol particles in the steam generator bundle flooded with water than in a dry bundle. → Much higher retention of aerosol particles in the steam generator bundle than in a bare pool. → Bare pool models have to be adapted to be applicable for flooded bundles. - Abstract: A steam generator tube rupture in a pressurized water reactor may cause accidental release of radioactive particles into the environment. Its specific significance is in its potential to bypass the containment thereby providing a direct pathway of the radioactivity from the primary circuit to the environment. Under certain severe accident scenarios, the steam generator bundle may be flooded with water. In addition, some severe accident management procedures are designed to minimize the release of radioactivity into the environment by flooding the defective steam generator secondary side with water when the steam generator has dried out. To extend our understanding of the particle retention phenomena in the flooded steam generator bundle, tests were conducted in the ARTIST and ARTIST II programs to determine the effect of different parameters on particle retention. The effects of particle type (spherical or agglomerate), particle size, gas mass flow rate, and the break submergence on particle retention were investigated. Results can be summarized as follows: increasing particle inertia was found to increase retention in the flooded bundle. Particle shape, i.e., agglomerate or spherical structure, did not affect retention significantly. Even with a very low submergence, 0.3 m above the tube break, significant aerosol retention took place underlining the importance of the jet-bundle interactions close to the tube break. Droplets were entrained from the water surface with

Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures

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Ionut Bebu

2016-06-01

Full Text Available For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR from several studies, the number needed to treat (NNT, and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates.

A clinical trial to evaluate the retention of a silver cermet-ionomer cement used as a fissure sealant.

Science.gov (United States)

Mills, R W; Ball, I A

1993-01-01

A randomized clinical trial was under-taken to compare the retention of a silver cermet-ionomer cement, Ketac Silver, with a conventional, autopolymerizing BIS-GMA resin sealant, Delton, using matched pairs of fissure sites within each subject's mouth. One hundred twenty matched contralateral pairs of fissure sites in first and second permanent molars of 53 school children were sealed with the two materials. The choice of site and material was selected at random. The ages of the children ranged from five to 16 years; first permanent molars were sealed in the five- to 10-year age group, and second permanent molars in the 11- to 16-year age group. Sealants were assessed as present, partly present, or absent at 6, 12, and 24 months. The number of pairs of sites available for reassessment declined from 102 at six months to 59 at 24 months as patients were lost to the study. Retention rates were higher for the Ketac Silver sealants at all three inspection intervals (P cermet cement was better retained than conventional resin sealants in younger children.

Liquid Effluent Retention Facility

Data.gov (United States)

Federal Laboratory Consortium — The Liquid Effluent Retention Facility (LERF) is located in the central part of the Hanford Site. LERF is permitted by the State of Washington and has three liquid...

Faculty Personality: A Factor of Student Retention

Science.gov (United States)

Shaw, Cassandra S.; Wu, Xiaodong; Irwin, Kathleen C.; Patrizi, L. A. Chad

2016-01-01

The purpose of this study was to determine the relationship between student retention and faculty personality as it was hypothesized that faculty personality has an effect on student retention. The methodology adopted for this study was quantitative and in two parts 1) using linear regression models to examine the impact or causality of faculty…

Motor Unit Interpulse Intervals During High Force Contractions.

Science.gov (United States)

Stock, Matt S; Thompson, Brennan J

2016-01-01

We examined the means, medians, and variability for motor-unit interpulse intervals (IPIs) during voluntary, high force contractions. Eight men (mean age = 22 years) attempted to perform isometric contractions at 90% of their maximal voluntary contraction force while bipolar surface electromyographic (EMG) signals were detected from the vastus lateralis and vastus medialis muscles. Surface EMG signal decomposition was used to determine the recruitment thresholds and IPIs of motor units that demonstrated accuracy levels ≥ 96.0%. Motor units with high recruitment thresholds demonstrated longer mean IPIs, but the coefficients of variation were similar across all recruitment thresholds. Polynomial regression analyses indicated that for both muscles, the relationship between the means and standard deviations of the IPIs was linear. The majority of IPI histograms were positively skewed. Although low-threshold motor units were associated with shorter IPIs, the variability among motor units with differing recruitment thresholds was comparable.

Diagnostic accuracy of routine blood examinations and CSF lactate level for post-neurosurgical bacterial meningitis.

Science.gov (United States)

Zhang, Yang; Xiao, Xiong; Zhang, Junting; Gao, Zhixian; Ji, Nan; Zhang, Liwei

2017-06-01

To evaluate the diagnostic accuracy of routine blood examinations and Cerebrospinal Fluid (CSF) lactate level for Post-neurosurgical Bacterial Meningitis (PBM) at a large sample-size of post-neurosurgical patients. The diagnostic accuracies of routine blood examinations and CSF lactate level to distinguish between PAM and PBM were evaluated with the values of the Area Under the Curve of the Receiver Operating Characteristic (AUC -ROC ) by retrospectively analyzing the datasets of post-neurosurgical patients in the clinical information databases. The diagnostic accuracy of routine blood examinations was relatively low (AUC -ROC CSF lactate level achieved rather high diagnostic accuracy (AUC -ROC =0.891; CI 95%, 0.852-0.922). The variables of patient age, operation duration, surgical diagnosis and postoperative days (the interval days between the neurosurgery and examinations) were shown to affect the diagnostic accuracy of these examinations. The variables were integrated with routine blood examinations and CSF lactate level by Fisher discriminant analysis to improve their diagnostic accuracy. As a result, the diagnostic accuracy of blood examinations and CSF lactate level was significantly improved with an AUC -ROC value=0.760 (CI 95%, 0.737-0.782) and 0.921 (CI 95%, 0.887-0.948) respectively. The PBM diagnostic accuracy of routine blood examinations was relatively low, whereas the accuracy of CSF lactate level was high. Some variables that are involved in the incidence of PBM can also affect the diagnostic accuracy for PBM. Taking into account the effects of these variables significantly improves the diagnostic accuracies of routine blood examinations and CSF lactate level. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Target Price Accuracy

Directory of Open Access Journals (Sweden)

Alexander G. Kerl

2011-04-01

Full Text Available This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio. However, target price accuracy is positively related to the level of detail of each report, company size and the reputation of the investment bank. The potential conflicts of interests between an analyst and a covered company do not bias forecast accuracy.

Retention of Millennial Employees in the Army Acquisition Workforce

Science.gov (United States)

2016-04-07

the job market affects the retention of all generations of employees, not only Millennials (Sorenson & Garman, 2013, p. 3). If the employees’ needs...having more at stake rather than having a specific fundamental difference in how they approach staying in a job . Millennial Retention Factors...that personal characteristics, plus preferred job characteristics, plus quality of work experience, equals high employee retention , as depicted in

Career satisfaction and retention risk among Wisconsin internists.

Science.gov (United States)

Giriyappa, Pradeep; Sullivan, Kandis K

2009-09-01

Physician career satisfaction has been studied extensively, but career satisfaction as it relates to retention is less well studied. The objective was to assess the relationship between career satisfaction and retention in primary care internal medicine physicians in Wisconsin. In this descriptive quantitative study, survey data was assessed for correlations between career satisfaction, risk to retention, and demographics. The survey included 1231 primary care internal medicine physicians in the Wisconsin Medical Directory (2007). Responses were measured by career satisfaction variables, and demographics and retention variables for the purpose of correlations and regression analysis. Survey responses included 573 physicians. An additional 85 physicians were disqualified. The final survey group included 1146 physicians for a response rate of 50%. A total of 116 physicians (20.2%) reported anticipating leaving their current position, 84 (14.7%) physicians reported anticipating leaving the career of medicine. Identified at risk for retention were 144 (25.1%) physicians. The lowest career satisfaction scores were reported in the areas of compensation (3.19) and practice (3.42) on a scale of 1 (very dissatisfied) to 5 (very satisfied). The highest correlations to retention were associated with practice, followed by compensation satisfaction. The level of significance for this study was identified as 0.05, and the P-value was 0.000. The study findings reveal a significant risk to the stability of continuity of care for patients, and may cost Wisconsin health care organizations more than $35 million in recruitment costs to replace departing physicians.

Dynamic detection-rate-based bit allocation with genuine interval concealment for binary biometric representation.

Science.gov (United States)

Lim, Meng-Hui; Teoh, Andrew Beng Jin; Toh, Kar-Ann

2013-06-01

Biometric discretization is a key component in biometric cryptographic key generation. It converts an extracted biometric feature vector into a binary string via typical steps such as segmentation of each feature element into a number of labeled intervals, mapping of each interval-captured feature element onto a binary space, and concatenation of the resulted binary output of all feature elements into a binary string. Currently, the detection rate optimized bit allocation (DROBA) scheme is one of the most effective biometric discretization schemes in terms of its capability to assign binary bits dynamically to user-specific features with respect to their discriminability. However, we learn that DROBA suffers from potential discriminative feature misdetection and underdiscretization in its bit allocation process. This paper highlights such drawbacks and improves upon DROBA based on a novel two-stage algorithm: 1) a dynamic search method to efficiently recapture such misdetected features and to optimize the bit allocation of underdiscretized features and 2) a genuine interval concealment technique to alleviate crucial information leakage resulted from the dynamic search. Improvements in classification accuracy on two popular face data sets vindicate the feasibility of our approach compared with DROBA.

Evaluation of electrical impedance ratio measurements in accuracy of electronic apex locators.

Science.gov (United States)

Kim, Pil-Jong; Kim, Hong-Gee; Cho, Byeong-Hoon

2015-05-01

The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL). The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data acquired were plotted to identify correlations between impedance and log-scaled frequency. The accuracy of the impedance ratio method used to detect the apical constriction (APC) in most EALs was evaluated using linear ramp function fitting. Changes of impedance ratios for various frequencies were evaluated for a variety of file positions. Among the ten papers selected in the search process, the first-order equations between log-scaled frequency and impedance were in the negative direction. When the model for the ratios was assumed to be a linear ramp function, the ratio values decreased if the file went deeper and the average ratio values of the left and right horizontal zones were significantly different in 8 out of 9 studies. The APC was located within the interval of linear relation between the left and right horizontal zones of the linear ramp model. Using the ratio method, the APC was located within a linear interval. Therefore, using the impedance ratio between electrical impedance measurements at different frequencies was a robust method for detection of the APC.

Assessing Potential Additional PFAS Retention Processes in the Subsurface

Science.gov (United States)

Brusseau, M. L.

2017-12-01

Understanding the transport and fate of per- and poly-fluorinated alkyl substances (PFASs) in the subsurface is critical for accurate risk assessments and design of effective remedial actions. Current conceptual and mathematical models are based on an assumption that solid-phase adsorption is the sole source of retention for PFASs. However, additional retention processes may be relevant for PFAS compounds in vadose-zone systems and in source zones that contain trapped immiscible organic liquids. These include adsorption at the air-water interface, partitioning to the soil atmosphere, adsorption at the NAPL-water interface, and absorption by NAPL. A multi-process retention model is proposed to account for these potential additional sources of PFAS retardation. An initial assessment of the relative magnitudes and significance of these retention processes was conducted for three representative PFASs, perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and 8:2 fluorotelomer alcohol (FTOH). Data collected from the literature were used to determine measured or estimated values for the relevant distribution coefficients, which were in turn used to calculate retardation factors for a representative porous medium. Adsorption at the air-water interface was shown to be a primary source of retention for PFOA and PFOS, contributing approximately 80% of total retardation. Adsorption to NAPL-water interfaces and absorption by bulk NAPL were also shown to be significant sources of retention for PFOS and PFOA. The latter process was the predominant source of retention for 8:2 FTOH, contributing 98% of total retardation. These results indicate that we may anticipate significant retention of PFASs by these additional processes. In such cases, retardation of PFASs in source areas may be significantly greater than what is typically estimated based on the standard assumption of solid-phase adsorption as the sole retention mechanism. This has significant ramifications for

A Smart High Accuracy Silicon Piezoresistive Pressure Sensor Temperature Compensation System

Directory of Open Access Journals (Sweden)

Guanwu Zhou

2014-07-01

Full Text Available Theoretical analysis in this paper indicates that the accuracy of a silicon piezoresistive pressure sensor is mainly affected by thermal drift, and varies nonlinearly with the temperature. Here, a smart temperature compensation system to reduce its effect on accuracy is proposed. Firstly, an effective conditioning circuit for signal processing and data acquisition is designed. The hardware to implement the system is fabricated. Then, a program is developed on LabVIEW which incorporates an extreme learning machine (ELM as the calibration algorithm for the pressure drift. The implementation of the algorithm was ported to a micro-control unit (MCU after calibration in the computer. Practical pressure measurement experiments are carried out to verify the system’s performance. The temperature compensation is solved in the interval from −40 to 85 °C. The compensated sensor is aimed at providing pressure measurement in oil-gas pipelines. Compared with other algorithms, ELM acquires higher accuracy and is more suitable for batch compensation because of its higher generalization and faster learning speed. The accuracy, linearity, zero temperature coefficient and sensitivity temperature coefficient of the tested sensor are 2.57% FS, 2.49% FS, 8.1 × 10−5/°C and 29.5 × 10−5/°C before compensation, and are improved to 0.13%FS, 0.15%FS, 1.17 × 10−5/°C and 2.1 × 10−5/°C respectively, after compensation. The experimental results demonstrate that the proposed system is valid for the temperature compensation and high accuracy requirement of the sensor.

Towards a chromatographic similarity index to establish localised quantitative structure-retention relationships for retention prediction. II Use of Tanimoto similarity index in ion chromatography.

Science.gov (United States)

Park, Soo Hyun; Talebi, Mohammad; Amos, Ruth I J; Tyteca, Eva; Haddad, Paul R; Szucs, Roman; Pohl, Christopher A; Dolan, John W

2017-11-10

Quantitative Structure-Retention Relationships (QSRR) are used to predict retention times of compounds based only on their chemical structures encoded by molecular descriptors. The main concern in QSRR modelling is to build models with high predictive power, allowing reliable retention prediction for the unknown compounds across the chromatographic space. With the aim of enhancing the prediction power of the models, in this work, our previously proposed QSRR modelling approach called "federation of local models" is extended in ion chromatography to predict retention times of unknown ions, where a local model for each target ion (unknown) is created using only structurally similar ions from the dataset. A Tanimoto similarity (TS) score was utilised as a measure of structural similarity and training sets were developed by including ions that were similar to the target ion, as defined by a threshold value. The prediction of retention parameters (a- and b-values) in the linear solvent strength (LSS) model in ion chromatography, log k=a - blog[eluent], allows the prediction of retention times under all eluent concentrations. The QSRR models for a- and b-values were developed by a genetic algorithm-partial least squares method using the retention data of inorganic and small organic anions and larger organic cations (molecular mass up to 507) on four Thermo Fisher Scientific columns (AS20, AS19, AS11HC and CS17). The corresponding predicted retention times were calculated by fitting the predicted a- and b-values of the models into the LSS model equation. The predicted retention times were also plotted against the experimental values to evaluate the goodness of fit and the predictive power of the models. The application of a TS threshold of 0.6 was found to successfully produce predictive and reliable QSRR models (Q ext(F2) 2 >0.8 and Mean Absolute Error<0.1), and hence accurate retention time predictions with an average Mean Absolute Error of 0.2min. Crown Copyright �

A review of trends in attrition rates for surgical faculty: a case for a sustainable retention strategy to cope with demographic and economic realities.

Science.gov (United States)

Satiani, Bhagwan; Williams, Thomas E; Brod, Heather; Way, David P; Ellison, E Christopher

2013-05-01

Our aim was to compare trends in retention of academic surgeons by reviewing surgical faculty attrition rates (leaving academic surgery for any reason) of 3 cohorts at 5-year intervals between 1996 and 2011. The Association of American Medical Colleges' Faculty Administrative Management On-Line User System database was queried for a retention report of all tenure/clinical track full-time MD faculty within our academic medical center on July 1, 1996 (group 1), July 1, 2001 (group 2), and July 1, 2006 (group 3). Retention was tracked for 5 years post snapshot. The individual 5-year cohort attrition rates (observed frequencies) were compared with combined attrition rates for all 3 groups (expected frequencies). Overall, attrition trends for groups 2 (lower) and 3 (higher) were significantly different than the trends for all groups combined. Minorities and professors at the full or associate rank in group 3 contributed to this difference. Faculty in group 3 leaving our academic medical center were significantly more likely to transition into nonacademic practice compared with the other 2 groups. Greater attrition in the last 5-year cohort, despite the increase in faculty positions, is worrisome. A continuous retention life cycle is critical if academic medical centers hope to compete for talent. Retention planning should include on-boarding programs for enculturation, monitoring of professional satisfaction, formalized mentoring of younger surgeons, retaining academic couples and a part-time workforce, leadership and talent management, exit interviews, and competitive financial packages. Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Targeting an efficient target-to-target interval for P300 speller brain–computer interfaces

Science.gov (United States)

Sellers, Eric W.; Wang, Xingyu

2013-01-01

Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain–computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, a P300 BCI using a 7 × 12 matrix explored new flash patterns (16-, 18- and 21-flash pattern) with different TTIs to assess the effects of TTI on P300 BCI performance. The new flash patterns were designed to minimize TTI, decrease repetition blindness, and examine the temporal relationship between each flash of a given stimulus by placing a minimum of one (16-flash pattern), two (18-flash pattern), or three (21-flash pattern) non-target flashes between each target flashes. Online results showed that the 16-flash pattern yielded the lowest classification accuracy among the three patterns. The results also showed that the 18-flash pattern provides a significantly higher information transfer rate (ITR) than the 21-flash pattern; both patterns provide high ITR and high accuracy for all subjects. PMID:22350331

Biofilm roughness determines Cryptosporidium parvum retention in environmental biofilms.

Science.gov (United States)

DiCesare, E A Wolyniak; Hargreaves, B R; Jellison, K L

2012-06-01

The genus Cryptosporidium is a group of waterborne protozoan parasites that have been implicated in significant outbreaks of gastrointestinal infections throughout the world. Biofilms trap these pathogens and can contaminate water supplies through subsequent release. Biofilm microbial assemblages were collected seasonally from three streams in eastern Pennsylvania and used to grow biofilms in laboratory microcosms. Daily oocyst counts in the influx and efflux flow allowed the calculation of daily oocyst retention in the biofilm. Following the removal of oocysts from the influx water, oocyst attachment to the biofilm declined to an equilibrium state within 5 days that was sustained for at least 25 days. Varying the oocyst loading rate for the system showed that biofilm retention could be saturated, suggesting that discrete binding sites determined the maximum number of oocysts retained. Oocyst retention varied seasonally but was consistent across all three sites; however, seasonal oocyst retention was not consistent across years at the same site. No correlation between oocyst attachment and any measured water quality parameter was found. However, oocyst retention was strongly correlated with biofilm surface roughness and roughness varied among seasons and across years. We hypothesize that biofilm roughness and oocyst retention are dependent on environmentally driven changes in the biofilm community rather than directly on water quality conditions. It is important to understand oocyst transport dynamics to reduce risks of human infection. Better understanding of factors controlling biofilm retention of oocysts should improve our understanding of oocyst transport at different scales.

Safeguards Workforce Repatriation, Retention and Utilization

Energy Technology Data Exchange (ETDEWEB)

Gallucci, Nicholas [Brookhaven National Lab. (BNL), Upton, NY (United States); Poe, Sarah [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-10-01

Brookhaven National Laboratory was tasked by NA-241 to assess the transition of former IAEA employees back to the United States, investigating the rate of retention and overall smoothness of the repatriation process among returning safeguards professionals. Upon conducting several phone interviews, study authors found that the repatriation process went smoothly for the vast majority and that workforce retention was high. However, several respondents expressed irritation over the minimal extent to which their safeguards expertise had been leveraged in their current positions. This sentiment was pervasive enough to prompt a follow-on study focusing on questions relating to the utilization rather than the retention of safeguards professionals. A second, web-based survey was conducted, soliciting responses from a larger sample pool. Results suggest that the safeguards workforce may be oversaturated, and that young professionals returning to the United States from Agency positions may soon encounter difficulties finding jobs in the field.

Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.

Science.gov (United States)

St Helen, Gideon; Havel, Christopher; Dempsey, Delia A; Jacob, Peyton; Benowitz, Neal L

2016-03-01

To measure the systemic retention of nicotine, propylene glycol (PG) and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. E-cigarette users recruited over the internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use. San Francisco, California, USA. Thirteen healthy, experienced adult e-cigarette users (six females and seven males). Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. E-cigarettes delivered an average of 1.33 (0.87-1.79) mg [mean and 95% confidence interval (CI)] of nicotine, and 93.8% of the inhaled dose, 1.22 (0.80-1.66) was systemically retained. Average maximum plasma nicotine concentration (Cmax ) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax ) was 2-5 minutes. One participant had Tmax of 30 minutes. 84.4% and 91.7% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 beats per minute after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarette users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. © 2015 Society for the Study of Addiction.

Relationship between management styles and nurses' retention at ...

African Journals Online (AJOL)

Conclusion: Management style and nurses' retention were significantly interrelated in terms of exploitative/authoritative management style. Recommendation, the researcher recommended that hospital leaders should plan and implement effective strategies to promote nurse retention. This can be done through creating a ...

Retention of gaseous isotopes

International Nuclear Information System (INIS)

Yarbro, O.O.; Mailen, J.C.; Stephenson, M.J.

1977-01-01

Retention of gaseous fission products during fuel reprocessing has, in the past, been limited to a modest retention of 131 I when processing fuels decayed less than about 180 days. The projected rapid growth of the nuclear power industry along with a desire to minimize environmental effects is leading to the reassessment of requirements for retention of gaseous fission products, including 131 I, 129 I, 85 Kr, 3 H, and 14 C. Starting in the late 1960s, a significant part of the LMFBR reprocessing development program has been devoted to understanding the behavior of gaseous fission products in plant process and effluent streams and the development of advanced systems for their removal. Systems for iodine control include methods for evolving up to 99% of the iodine from dissolver solutions to minimize its introduction and distribution throughout downstream equipment. An aqueous scrubbing system (Iodox) using 20 M HNO 3 as the scrubbing media effectively removes all significant iodine forms from off-gas streams while handling the kilogram quantities of iodine present in head-end and dissolver off-gas streams. Silver zeolite is very effective for removing iodine forms at low concentration from the larger-volume plant off-gas streams. Removal of iodine from plant liquid effluents by solid sorbents either prior to or following final vaporization appears feasible. Krypton is effectively released during dissolution and can be removed from the relatively small volume head-end and dissolver off-gas stream. Two methods appear applicable for removal and concentration of krypton: (1) selective absorption in fluorocarbons, and (2) cryogenic absorption in liquid nitrogen. The fluorocarbon absorption process appears to be rather tolerant of the normal contaminants (H 2 O, CO 2 , NOsub(x), and organics) present in typical reprocessing plant off-gas whereas the cryogenic system requires an extensive feed gas pretreatment system. Retention of tritium in a reprocessing plant is

Three-dimensional computed tomography measurement accuracy of varying Hill-Sachs lesion size.

Science.gov (United States)

Ho, Anthony; Kurdziel, Michael D; Koueiter, Denise M; Wiater, J Michael

2018-02-01

The glenoid track concept has been proposed to correlate shoulder stability with bone loss. Accurate assessment of Hill-Sachs lesion size preoperatively may affect surgical planning and postoperative outcomes; however, no measurement method has been universally accepted. This study aimed to assess the accuracy and reliability of measuring Hill-Sachs lesion sizes using 3-dimensional (3D) computed tomography (CT). Nine polyurethane humerus bone substitutes were used to create Hill-Sachs lesions of varying sizes with a combination of lesion depth (shallow, intermediate, and deep) and width (small, medium, and large). Specimens were scanned with a clinical CT scanner for size measurements and a micro-CT scanner for measurement of true lesion size. Six evaluators repeated measurements twice in a 2-week interval. Scans were measured by use of 3D CT reconstructions for length, width, and Hill-Sachs interval and with use of 2D CT for depth. The interclass correlation coefficient evaluated interobserver and intraobserver variability and percentage error, and Student t-tests assessed measurement accuracy. Interclass correlation coefficient reliability demonstrated strong agreement for all variables measured (0.856-0.975). Percentage error between measured length and measured depth and the true measurement significantly varied with respect to both lesion depth (P = .003 and P = .005, respectively) and lesion size (P = .049 and P = .004, respectively). The 3D CT imaging is effective and reproducible in determining lesion size. Determination of Hill-Sachs interval width is also reliable when it is applied to the glenoid track concept. Measured values on 3D and 2-dimensional imaging using a conventional CT scanner may slightly underestimate true measurements. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Interval stability for complex systems

Science.gov (United States)

Klinshov, Vladimir V.; Kirillov, Sergey; Kurths, Jürgen; Nekorkin, Vladimir I.

2018-04-01

Stability of dynamical systems against strong perturbations is an important problem of nonlinear dynamics relevant to many applications in various areas. Here, we develop a novel concept of interval stability, referring to the behavior of the perturbed system during a finite time interval. Based on this concept, we suggest new measures of stability, namely interval basin stability (IBS) and interval stability threshold (IST). IBS characterizes the likelihood that the perturbed system returns to the stable regime (attractor) in a given time. IST provides the minimal magnitude of the perturbation capable to disrupt the stable regime for a given interval of time. The suggested measures provide important information about the system susceptibility to external perturbations which may be useful for practical applications. Moreover, from a theoretical viewpoint the interval stability measures are shown to bridge the gap between linear and asymptotic stability. We also suggest numerical algorithms for quantification of the interval stability characteristics and demonstrate their potential for several dynamical systems of various nature, such as power grids and neural networks.

16 CFR 1203.16 - Dynamic strength of retention system test.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Dynamic strength of retention system test.... (2) The retention system strength test equipment shall consist of a dynamic impact apparatus that... stirrup. (2) Mark the pre-test position of the retention system, with the entire dynamic test apparatus...

Improvement of Accuracy in Environmental Dosimetry by TLD Cards Using Three-dimensional Calibration Method

Directory of Open Access Journals (Sweden)

HosseiniAliabadi S. J.

2015-06-01

Full Text Available Background: The angular dependency of response for TLD cards may cause deviation from its true value on the results of environmental dosimetry, since TLDs may be exposed to radiation at different angles of incidence from the surrounding area. Objective: A 3D setting of TLD cards has been calibrated isotropically in a standard radiation field to evaluate the improvement of the accuracy of measurement for environmental dosimetry. Method: Three personal TLD cards were rectangularly placed in a cylindrical holder, and calibrated using 1D and 3D calibration methods. Then, the dosimeter has been used simultaneously with a reference instrument in a real radiation field measuring the accumulated dose within a time interval. Result: The results show that the accuracy of measurement has been improved by 6.5% using 3D calibration factor in comparison with that of normal 1D calibration method. Conclusion: This system can be utilized in large scale environmental monitoring with a higher accuracy

A modelling study of long term green roof retention performance.

Science.gov (United States)

Stovin, Virginia; Poë, Simon; Berretta, Christian

2013-12-15

This paper outlines the development of a conceptual hydrological flux model for the long term continuous simulation of runoff and drought risk for green roof systems. A green roof's retention capacity depends upon its physical configuration, but it is also strongly influenced by local climatic controls, including the rainfall characteristics and the restoration of retention capacity associated with evapotranspiration during dry weather periods. The model includes a function that links evapotranspiration rates to substrate moisture content, and is validated against observed runoff data. The model's application to typical extensive green roof configurations is demonstrated with reference to four UK locations characterised by contrasting climatic regimes, using 30-year rainfall time-series inputs at hourly simulation time steps. It is shown that retention performance is dependent upon local climatic conditions. Volumetric retention ranges from 0.19 (cool, wet climate) to 0.59 (warm, dry climate). Per event retention is also considered, and it is demonstrated that retention performance decreases significantly when high return period events are considered in isolation. For example, in Sheffield the median per-event retention is 1.00 (many small events), but the median retention for events exceeding a 1 in 1 yr return period threshold is only 0.10. The simulation tool also provides useful information about the likelihood of drought periods, for which irrigation may be required. A sensitivity study suggests that green roofs with reduced moisture-holding capacity and/or low evapotranspiration rates will tend to offer reduced levels of retention, whilst high moisture-holding capacity and low evapotranspiration rates offer the strongest drought resistance. Copyright © 2013 Elsevier Ltd. All rights reserved.

A theoretical model of job retention for home health care nurses.

Science.gov (United States)

Ellenbecker, Carol Hall

2004-08-01

Predicted severe nursing shortages and an increasing demand for home health care services have made the retention of experienced, qualified nursing staff a priority for health care organizations. The purpose of this paper is to describe a theoretical model of job retention for home health care nurses. The theoretical model is an integration of the findings of empirical research related to intent to stay and retention, components of Neal's theory of home health care nursing practice and findings from earlier work to develop an instrument to measure home health care nurses' job satisfaction. The theoretical model identifies antecedents to job satisfaction of home health care nurses. The antecedents are intrinsic and extrinsic job characteristics. The model also proposes that job satisfaction is directly related to retention and indirectly related to retention though intent to stay. Individual nurse characteristics are indirectly related to retention through intent to stay. The individual characteristic of tenure is indirectly related to retention through autonomy, as an intrinsic characteristic of job satisfaction, and intent to stay. The proposed model can be used to guide research that explores gaps in knowledge about intent to stay and retention among home health care nurses.

Electric power demand forecasting using interval time series. A comparison between VAR and iMLP

International Nuclear Information System (INIS)

Garcia-Ascanio, Carolina; Mate, Carlos

2010-01-01

Electric power demand forecasts play an essential role in the electric industry, as they provide the basis for making decisions in power system planning and operation. A great variety of mathematical methods have been used for demand forecasting. The development and improvement of appropriate mathematical tools will lead to more accurate demand forecasting techniques. In order to forecast the monthly electric power demand per hour in Spain for 2 years, this paper presents a comparison between a new forecasting approach considering vector autoregressive (VAR) forecasting models applied to interval time series (ITS) and the iMLP, the multi-layer perceptron model adapted to interval data. In the proposed comparison, for the VAR approach two models are fitted per every hour, one composed of the centre (mid-point) and radius (half-range), and another one of the lower and upper bounds according to the interval representation assumed by the ITS in the learning set. In the case of the iMLP, only the model composed of the centre and radius is fitted. The other interval representation composed of the lower and upper bounds is obtained from the linear combination of the two. This novel approach, obtaining two bivariate models each hour, makes possible to establish, for different periods in the day, which interval representation is more accurate. Furthermore, the comparison between two different techniques adapted to interval time series allows us to determine the efficiency of these models in forecasting electric power demand. It is important to note that the iMLP technique has been selected for the comparison, as it has shown its accuracy in forecasting daily electricity price intervals. This work shows the ITS forecasting methods as a potential tool that will lead to a reduction in risk when making power system planning and operational decisions. (author)

Registered nurse retention strategies in nursing homes: a two-factor perspective.

Science.gov (United States)

Hunt, Selina R; Probst, Janice C; Haddock, Kathlyn S; Moran, Robert; Baker, Samuel L; Anderson, Ruth A; Corazzini, Kirsten

2012-01-01

As the American population ages and the proportion of individuals over the age of 65 expands, the demand for high-quality nursing home care will increase. However, nursing workforce instability threatens care quality and sustainability in this sector. Despite increasing attention to nursing home staff turnover, far less is known about registered nurse (RN) retention. In this study, the relationships between retention strategies, employee benefits, features of the practice environment, and RN retention were explored. Further, the utility of Herzberg's two-factor theory of motivation as a framework for nursing home retention studies was evaluated. This study was a secondary analysis of the nationally representative 2004 National Nursing Home Survey. The final sample of 1,174 participating nursing homes were either certified by Medicare or Medicaid or licensed by state agencies. We used a weighted multinomial logistic regression using an incremental approach to model the relationships. Although most nursing homes offered some combination of retention programs, the majority of strategies did not have a significant association with the level of RN retention reported by facilities. Director of nursing tenure and other extrinsic factors had the strongest association with RN retention in adjusted analyses. To improve RN retention, organizations may benefit greatly from stabilizing nursing home leadership, especially the director of nursing position. Second, managers of facilities with poor retention may consider adding career ladders for advancement, awarding attendance, and improving employee benefits. As a behavioral outcome of motivation and satisfaction, retention was not explained as expected using Herzberg's two-factor theory.

Statistical intervals a guide for practitioners

CERN Document Server

Hahn, Gerald J

2011-01-01

Presents a detailed exposition of statistical intervals and emphasizes applications in industry. The discussion differentiates at an elementary level among different kinds of statistical intervals and gives instruction with numerous examples and simple math on how to construct such intervals from sample data. This includes confidence intervals to contain a population percentile, confidence intervals on probability of meeting specified threshold value, and prediction intervals to include observation in a future sample. Also has an appendix containing computer subroutines for nonparametric stati

Statistics of return intervals between long heartbeat intervals and their usability for online prediction of disorders

International Nuclear Information System (INIS)

Bogachev, Mikhail I; Bunde, Armin; Kireenkov, Igor S; Nifontov, Eugene M

2009-01-01

We study the statistics of return intervals between large heartbeat intervals (above a certain threshold Q) in 24 h records obtained from healthy subjects. We find that both the linear and the nonlinear long-term memory inherent in the heartbeat intervals lead to power-laws in the probability density function P Q (r) of the return intervals. As a consequence, the probability W Q (t; Δt) that at least one large heartbeat interval will occur within the next Δt heartbeat intervals, with an increasing elapsed number of intervals t after the last large heartbeat interval, follows a power-law. Based on these results, we suggest a method of obtaining a priori information about the occurrence of the next large heartbeat interval, and thus to predict it. We show explicitly that the proposed method, which exploits long-term memory, is superior to the conventional precursory pattern recognition technique, which focuses solely on short-term memory. We believe that our results can be straightforwardly extended to obtain more reliable predictions in other physiological signals like blood pressure, as well as in other complex records exhibiting multifractal behaviour, e.g. turbulent flow, precipitation, river flows and network traffic.

Dynamic visual noise reduces confidence in short-term memory for visual information.

Science.gov (United States)

Kemps, Eva; Andrade, Jackie

2012-05-01

Previous research has shown effects of the visual interference technique, dynamic visual noise (DVN), on visual imagery, but not on visual short-term memory, unless retention of precise visual detail is required. This study tested the prediction that DVN does also affect retention of gross visual information, specifically by reducing confidence. Participants performed a matrix pattern memory task with three retention interval interference conditions (DVN, static visual noise and no interference control) that varied from trial to trial. At recall, participants indicated whether or not they were sure of their responses. As in previous research, DVN did not impair recall accuracy or latency on the task, but it did reduce recall confidence relative to static visual noise and no interference. We conclude that DVN does distort visual representations in short-term memory, but standard coarse-grained recall measures are insensitive to these distortions.

The use of adaptable automation: Effects of extended skill lay-off and changes in system reliability.

Science.gov (United States)

Sauer, Juergen; Chavaillaz, Alain

2017-01-01

This experiment aimed to examine how skill lay-off and system reliability would affect operator behaviour in a simulated work environment under wide-range and large-choice adaptable automation comprising six different levels. Twenty-four participants were tested twice during a 2-hr testing session, with the second session taking place 8 months after the first. In the middle of the second testing session, system reliability changed. The results showed that after the retention interval trust increased and self-confidence decreased. Complacency was unaffected by the lay-off period. Diagnostic speed slowed down after the retention interval but diagnostic accuracy was maintained. No difference between experimental conditions was found for automation management behaviour (i.e. level of automation chosen and frequency of switching between levels). There were few effects of system reliability. Overall, the findings showed that subjective measures were more sensitive to the impact of skill lay-off than objective behavioural measures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal effect on water retention curve of bentonite: experiment and thermodynamic modeling

International Nuclear Information System (INIS)

Qin Bing; Chen Zhenghai; Sun Faxin; Liu Yuemiao; Wang Ju

2012-01-01

The thermal effects on water retention curve of GMZ bentonite were investigated experimentally and theoretically. Water retention tests were conducted on GMZ bentonite at five temperatures ranging from 20℃ to 100℃. Test results showed that the water retention capacity and the hysteresis of the water retention curve decreased with increasing temperature, and that the water retention curves at different temperatures were almost parallel to each other. Based on the thermodynamics of sorption, a model was established to describe the temperature influence on the water retention curve. The model was validated by comparing the model predictions and the test results. (authors)

44 CFR 321.5 - Retention of industrial facilities.

Science.gov (United States)

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Retention of industrial facilities. 321.5 Section 321.5 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY..., DEPARTMENT OF ENERGY, MARITIME ADMINISTRATION) § 321.5 Retention of industrial facilities. (a) Industrial...

Effects of fire ash on soil water retention

NARCIS (Netherlands)

Stoof, C.R.; Wesseling, J.G.; Ritsema, C.J.

2010-01-01

Despite the pronounced effect of fire on soil hydrological systems, information on the direct effect of fire on soil water retention characteristics is limited and contradictory. To increase understanding in this area, the effect of fire on soil water retention was evaluated using laboratory burning

40 CFR 94.406 - Reports filing: record retention.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Reports filing: record retention. 94.406 Section 94.406 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Requirements, Voluntary Emission Recall Program § 94.406 Reports filing: record retention. (a) The reports...

21 CFR 320.38 - Retention of bioavailability samples.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Retention of bioavailability samples. 320.38... (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.38 Retention of bioavailability samples...

5 CFR 2411.14 - Record retention and preservation.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Record retention and preservation. 2411.14 Section 2411.14 Administrative Personnel FEDERAL LABOR RELATIONS AUTHORITY, GENERAL COUNSEL OF THE... OFFICIAL INFORMATION § 2411.14 Record retention and preservation. The Authority, the General Counsel, the...

48 CFR 2152.215-70 - Contractor records retention.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contractor records... PRECONTRACT PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 2152.215-70 Contractor records retention. As prescribed in 2115.071, insert the following clause: Contractor Records Retention (OCT 2005...

48 CFR 1652.204-70 - Contractor records retention.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contractor records... of FEHBP Clauses 1652.204-70 Contractor records retention. As prescribed in 1604.705 the following clause will be inserted in all FEHB Program contracts. Contractor Records Retention (JUL 2005...

Probability Distribution for Flowing Interval Spacing

International Nuclear Information System (INIS)

Kuzio, S.

2001-01-01

The purpose of this analysis is to develop a probability distribution for flowing interval spacing. A flowing interval is defined as a fractured zone that transmits flow in the Saturated Zone (SZ), as identified through borehole flow meter surveys (Figure 1). This analysis uses the term ''flowing interval spacing'' as opposed to fractured spacing, which is typically used in the literature. The term fracture spacing was not used in this analysis because the data used identify a zone (or a flowing interval) that contains fluid-conducting fractures but does not distinguish how many or which fractures comprise the flowing interval. The flowing interval spacing is measured between the midpoints of each flowing interval. Fracture spacing within the SZ is defined as the spacing between fractures, with no regard to which fractures are carrying flow. The Development Plan associated with this analysis is entitled, ''Probability Distribution for Flowing Interval Spacing'', (CRWMS M and O 2000a). The parameter from this analysis may be used in the TSPA SR/LA Saturated Zone Flow and Transport Work Direction and Planning Documents: (1) ''Abstraction of Matrix Diffusion for SZ Flow and Transport Analyses'' (CRWMS M and O 1999a) and (2) ''Incorporation of Heterogeneity in SZ Flow and Transport Analyses'', (CRWMS M and O 1999b). A limitation of this analysis is that the probability distribution of flowing interval spacing may underestimate the effect of incorporating matrix diffusion processes in the SZ transport model because of the possible overestimation of the flowing interval spacing. Larger flowing interval spacing results in a decrease in the matrix diffusion processes. This analysis may overestimate the flowing interval spacing because the number of fractures that contribute to a flowing interval cannot be determined from the data. Because each flowing interval probably has more than one fracture contributing to a flowing interval, the true flowing interval spacing could be

Psychological determinants of job retention in multiple sclerosis.

Science.gov (United States)

Ford, Helen L; Wicks, Charlotte R; Stroud, Amanda; Tennant, Alan

2018-01-01

Maintaining paid work is a key issue for people with multiple sclerosis (PwMS). Different factors, including psychological attributes, can influence job retention. Understanding their role should inform potential interventions to help PwMS retain employment. The aim of this study was to identify the key factors which improve job retention in an employed cohort of PwMS. This three-year longitudinal study used validated self-completed measures of physical and psychological factors at four time points over 28 months. Of 208 employed PwMS, just over 1 in 10 was no longer working at the end of the study. Three variables were predictive of continuing employment; low 'work instability' at baseline increased the odds of job retention by a factor of 12.76; high levels of self-efficacy by a factor of 4.66 and being less than 50 years of age increased the odds of job retention by a factor of 3.90. Path analysis demonstrated the mediating role of self-efficacy between the physical impact of MS and the level of work instability at exit. Screening for work instability and self-efficacy in a clinical setting followed by appropriate interventions to increase self-efficacy and reduce work instability could aid job retention in MS.

Two-sorted Point-Interval Temporal Logics

DEFF Research Database (Denmark)

Balbiani, Philippe; Goranko, Valentin; Sciavicco, Guido

2011-01-01

There are two natural and well-studied approaches to temporal ontology and reasoning: point-based and interval-based. Usually, interval-based temporal reasoning deals with points as particular, duration-less intervals. Here we develop explicitly two-sorted point-interval temporal logical framework...... whereby time instants (points) and time periods (intervals) are considered on a par, and the perspective can shift between them within the formal discourse. We focus on fragments involving only modal operators that correspond to the inter-sort relations between points and intervals. We analyze...

Confidence Intervals for Asbestos Fiber Counts: Approximate Negative Binomial Distribution.

Science.gov (United States)

Bartley, David; Slaven, James; Harper, Martin

2017-03-01

The negative binomial distribution is adopted for analyzing asbestos fiber counts so as to account for both the sampling errors in capturing only a finite number of fibers and the inevitable human variation in identifying and counting sampled fibers. A simple approximation to this distribution is developed for the derivation of quantiles and approximate confidence limits. The success of the approximation depends critically on the use of Stirling's expansion to sufficient order, on exact normalization of the approximating distribution, on reasonable perturbation of quantities from the normal distribution, and on accurately approximating sums by inverse-trapezoidal integration. Accuracy of the approximation developed is checked through simulation and also by comparison to traditional approximate confidence intervals in the specific case that the negative binomial distribution approaches the Poisson distribution. The resulting statistics are shown to relate directly to early research into the accuracy of asbestos sampling and analysis. Uncertainty in estimating mean asbestos fiber concentrations given only a single count is derived. Decision limits (limits of detection) and detection limits are considered for controlling false-positive and false-negative detection assertions and are compared to traditional limits computed assuming normal distributions. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2017.

High-intensity interval training: Modulating interval duration in overweight/obese men.

Science.gov (United States)

Smith-Ryan, Abbie E; Melvin, Malia N; Wingfield, Hailee L

2015-05-01

High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations. In a randomized controlled pilot design, we evaluated the effects of two types of interval training protocols, varying in intensity and interval duration, on clinical outcomes in overweight/obese men. Twenty-five men [body mass index (BMI) > 25 kg · m(2)] completed baseline body composition measures: fat mass (FM), lean mass (LM) and percent body fat (%BF) and fasting blood glucose, lipids and insulin (IN). A graded exercise cycling test was completed for peak oxygen consumption (VO2peak) and power output (PO). Participants were randomly assigned to high-intensity short interval (1MIN-HIIT), high-intensity interval (2MIN-HIIT) or control groups. 1MIN-HIIT and 2MIN-HIIT completed 3 weeks of cycling interval training, 3 days/week, consisting of either 10 × 1 min bouts at 90% PO with 1 min rests (1MIN-HIIT) or 5 × 2 min bouts with 1 min rests at undulating intensities (80%-100%) (2MIN-HIIT). There were no significant training effects on FM (Δ1.06 ± 1.25 kg) or %BF (Δ1.13% ± 1.88%), compared to CON. Increases in LM were not significant but increased by 1.7 kg and 2.1 kg for 1MIN and 2MIN-HIIT groups, respectively. Increases in VO2peak were also not significant for 1MIN (3.4 ml·kg(-1) · min(-1)) or 2MIN groups (2.7 ml · kg(-1) · min(-1)). IN sensitivity (HOMA-IR) improved for both training groups (Δ-2.78 ± 3.48 units; p < 0.05) compared to CON. HIIT may be an effective short-term strategy to improve cardiorespiratory fitness and IN sensitivity in overweight males.

Overinterpretation and misreporting of diagnostic accuracy studies: evidence of "spin".

Science.gov (United States)

Ochodo, Eleanor A; de Haan, Margriet C; Reitsma, Johannes B; Hooft, Lotty; Bossuyt, Patrick M; Leeflang, Mariska M G

2013-05-01

To estimate the frequency of distorted presentation and overinterpretation of results in diagnostic accuracy studies. MEDLINE was searched for diagnostic accuracy studies published between January and June 2010 in journals with an impact factor of 4 or higher. Articles included were primary studies of the accuracy of one or more tests in which the results were compared with a clinical reference standard. Two authors scored each article independently by using a pretested data-extraction form to identify actual overinterpretation and practices that facilitate overinterpretation, such as incomplete reporting of study methods or the use of inappropriate methods (potential overinterpretation). The frequency of overinterpretation was estimated in all studies and in a subgroup of imaging studies. Of the 126 articles, 39 (31%; 95% confidence interval [CI]: 23, 39) contained a form of actual overinterpretation, including 29 (23%; 95% CI: 16, 30) with an overly optimistic abstract, 10 (8%; 96% CI: 3%, 13%) with a discrepancy between the study aim and conclusion, and eight with conclusions based on selected subgroups. In our analysis of potential overinterpretation, authors of 89% (95% CI: 83%, 94%) of the studies did not include a sample size calculation, 88% (95% CI: 82%, 94%) did not state a test hypothesis, and 57% (95% CI: 48%, 66%) did not report CIs of accuracy measurements. In 43% (95% CI: 34%, 52%) of studies, authors were unclear about the intended role of the test, and in 3% (95% CI: 0%, 6%) they used inappropriate statistical tests. A subgroup analysis of imaging studies showed 16 (30%; 95% CI: 17%, 43%) and 53 (100%; 95% CI: 92%, 100%) contained forms of actual and potential overinterpretation, respectively. Overinterpretation and misreporting of results in diagnostic accuracy studies is frequent in journals with high impact factors. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120527/-/DC1. © RSNA, 2013.

Acute Retention of Urine Following Intraocular Surgery | Nwosu ...

African Journals Online (AJOL)

Hyperosmolar agents and carbonic anhydrase inhibitors are used to lower the intraocular pressure and thus minimize the chances of vitreous loss during intraocular surgery. However, these agents could precipitate urinary retention. This is a report on two elderly men who had perioperative acute urinary retention following ...

The Leech method for diagnosing constipation: intra- and interobserver variability and accuracy

Energy Technology Data Exchange (ETDEWEB)

Lorijn, Fleur de; Voskuijl, Wieger P.; Taminiau, Jan A.; Benninga, Marc A. [Emma Children' s Hospital, Department of Paediatric Gastroenterology and Nutrition, Amsterdam (Netherlands); Rijn, Rick R. van; Henneman, Onno D.F. [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Heijmans, Jarom [Emma Children' s Hospital, Department of Paediatric Gastroenterology and Nutrition, Amsterdam (Netherlands); Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Reitsma, Johannes B. [Academic Medical Centre, Department of Clinical Epidemiology and Biostatistics, Amsterdam (Netherlands)

2006-01-01

The data concerning the value of a plain abdominal radiograph in childhood constipation are inconsistent. Recently, positive results have been reported of a new radiographic scoring system, ''the Leech method'', for assessing faecal loading. To assess intra- and interobserver variability and determine diagnostic accuracy of the Leech method in identifying children with functional constipation (FC). A total of 89 children (median age 9.8 years) with functional gastrointestinal disorders were included in the study. Based on clinical parameters, 52 fulfilled the criteria for FC, six fulfilled the criteria for functional abdominal pain (FAP), and 31 for functional non-retentive faecal incontinence (FNRFI); the latter two groups provided the controls. To assess intra- and interobserver variability of the Leech method three scorers scored the same abdominal radiograph twice. A Leech score of 9 or more was considered as suggestive of constipation. ROC analysis was used to determine the diagnostic accuracy of the Leech method in separating patients with FC from control patients. Significant intraobserver variability was found between two scorers (P=0.005 and P<0.0001), whereas there was no systematic difference between the two scores of the other scorer (P=0.89). The scores between scorers differed systematically and displayed large variability. The area under the ROC curve was 0.68 (95% CI 0.58-0.80), indicating poor diagnostic accuracy. The Leech scoring method for assessing faecal loading on a plain abdominal radiograph is of limited value in the diagnosis of FC in children. (orig.)

Emotional intelligence, performance, and retention in clinical staff nurses.

Science.gov (United States)

Codier, Estelle; Kamikawa, Cindy; Kooker, Barbara M; Shoultz, Jan

2009-01-01

Emotional intelligence has been correlated with performance, retention, and organizational commitment in professions other than nursing. A 2006 pilot study provided the first evidence of a correlation between emotional intelligence and performance in clinical staff nurses. A follow-up study was completed, the purpose of which was to explore emotional intelligence, performance level, organizational commitment, and retention. A convenience sample of 350 nurses in a large medical center in urban Hawaii participated in this study. This article reports the findings pertaining to the subset of 193 clinical staff nurses who responded. The Mayer-Salovey-Caruso Emotional Intelligence Test instrument was used to measure emotional intelligence abilities. Performance was defined as ranking on a clinical ladder. Commitment was scored on a Likert scale. The following variables measured retention: total years in nursing, years in current job, total years anticipated in current job, and total anticipated career length. Emotional intelligence scores in clinical staff nurses correlated positively with both performance level and retention variables. Clinical staff nurses with higher emotional intelligence scores demonstrated higher performance, had longer careers, and greater job retention.

Some Characterizations of Convex Interval Games

NARCIS (Netherlands)

Brânzei, R.; Tijs, S.H.; Alparslan-Gok, S.Z.

2008-01-01

This paper focuses on new characterizations of convex interval games using the notions of exactness and superadditivity. We also relate big boss interval games with concave interval games and obtain characterizations of big boss interval games in terms of exactness and subadditivity.

Academic staff recruitment and retention challenges at the University ...

African Journals Online (AJOL)

Academic staff recruitment and retention challenges at the University of Botswana medical school. ... To document the medical school's staff recruitment and retention trends and challenges, and to propose ... AJOL African Journals Online.

Propagation of measurement accuracy to biomass soft-sensor estimation and control quality.

Science.gov (United States)

Steinwandter, Valentin; Zahel, Thomas; Sagmeister, Patrick; Herwig, Christoph

2017-01-01

In biopharmaceutical process development and manufacturing, the online measurement of biomass and derived specific turnover rates is a central task to physiologically monitor and control the process. However, hard-type sensors such as dielectric spectroscopy, broth fluorescence, or permittivity measurement harbor various disadvantages. Therefore, soft-sensors, which use measurements of the off-gas stream and substrate feed to reconcile turnover rates and provide an online estimate of the biomass formation, are smart alternatives. For the reconciliation procedure, mass and energy balances are used together with accuracy estimations of measured conversion rates, which were so far arbitrarily chosen and static over the entire process. In this contribution, we present a novel strategy within the soft-sensor framework (named adaptive soft-sensor) to propagate uncertainties from measurements to conversion rates and demonstrate the benefits: For industrially relevant conditions, hereby the error of the resulting estimated biomass formation rate and specific substrate consumption rate could be decreased by 43 and 64 %, respectively, compared to traditional soft-sensor approaches. Moreover, we present a generic workflow to determine the required raw signal accuracy to obtain predefined accuracies of soft-sensor estimations. Thereby, appropriate measurement devices and maintenance intervals can be selected. Furthermore, using this workflow, we demonstrate that the estimation accuracy of the soft-sensor can be additionally and substantially increased.

The establishment of tocopherol reference intervals for Hungarian adult population using a validated HPLC method.

Science.gov (United States)

Veres, Gábor; Szpisjak, László; Bajtai, Attila; Siska, Andrea; Klivényi, Péter; Ilisz, István; Földesi, Imre; Vécsei, László; Zádori, Dénes

2017-09-01

Evidence suggests that decreased α-tocopherol (the most biologically active substance in the vitamin E group) level can cause neurological symptoms, most likely ataxia. The aim of the current study was to first provide reference intervals for serum tocopherols in the adult Hungarian population with appropriate sample size, recruiting healthy control subjects and neurological patients suffering from conditions without symptoms of ataxia, myopathy or cognitive deficiency. A validated HPLC method applying a diode array detector and rac-tocol as internal standard was utilized for that purpose. Furthermore, serum cholesterol levels were determined as well for data normalization. The calculated 2.5-97.5% reference intervals for α-, β/γ- and δ-tocopherols were 24.62-54.67, 0.81-3.69 and 0.29-1.07 μm, respectively, whereas the tocopherol/cholesterol ratios were 5.11-11.27, 0.14-0.72 and 0.06-0.22 μmol/mmol, respectively. The establishment of these reference intervals may improve the diagnostic accuracy of tocopherol measurements in certain neurological conditions with decreased tocopherol levels. Moreover, the current study draws special attention to the possible pitfalls in the complex process of the determination of reference intervals as well, including the selection of study population, the application of internal standard and method validation and the calculation of tocopherol/cholesterol ratios. Copyright © 2017 John Wiley & Sons, Ltd.

Actual drawing of histological images improves knowledge retention.

Science.gov (United States)

Balemans, Monique C M; Kooloos, Jan G M; Donders, A Rogier T; Van der Zee, Catharina E E M

2016-01-01

Medical students have to process a large amount of information during the first years of their study, which has to be retained over long periods of nonuse. Therefore, it would be beneficial when knowledge is gained in a way that promotes long-term retention. Paper-and-pencil drawings for the uptake of form-function relationships of basic tissues has been a teaching tool for a long time, but now seems to be redundant with virtual microscopy on computer-screens and printers everywhere. Several studies claimed that, apart from learning from pictures, actual drawing of images significantly improved knowledge retention. However, these studies applied only immediate post-tests. We investigated the effects of actual drawing of histological images, using randomized cross-over design and different retention periods. The first part of the study concerned esophageal and tracheal epithelium, with 384 medical and biomedical sciences students randomly assigned to either the drawing or the nondrawing group. For the second part of the study, concerning heart muscle cells, students from the previous drawing group were now assigned to the nondrawing group and vice versa. One, four, and six weeks after the experimental intervention, the students were given a free recall test and a questionnaire or drawing exercise, to determine the amount of knowledge retention. The data from this study showed that knowledge retention was significantly improved in the drawing groups compared with the nondrawing groups, even after four or six weeks. This suggests that actual drawing of histological images can be used as a tool to improve long-term knowledge retention. © 2015 American Association of Anatomists.

Multivariate interval-censored survival data

DEFF Research Database (Denmark)

Hougaard, Philip

2014-01-01

Interval censoring means that an event time is only known to lie in an interval (L,R], with L the last examination time before the event, and R the first after. In the univariate case, parametric models are easily fitted, whereas for non-parametric models, the mass is placed on some intervals, de...

Evaluation of {sup 131}I retention in several adsorbers

Energy Technology Data Exchange (ETDEWEB)

Catanoso, Marcela F.; Osso Junior, Joao Alberto, E-mail: marcela.forli@gmail.co, E-mail: jaosso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia

2011-07-01

Several iodine radioisotopes are used in nuclear medicine for treatment and diagnostic purposes. The radioisotope {sup 131}I is used both in diagnosis and therapy due to its physical characteristics of decay by {beta}{sup -} and its {gamma}-ray emissions suitable for diagnosis. It is routinely produced at IPEN through the irradiation of TeO{sub 2} targets in the IEA-R1m nuclear reactor. After the irradiation, the {sup 131}I is separated by dry distillation, where the targets are put in an oven, heated at 760 deg C for 2 hours and the {sup 131}I, volatile, is carried by an O{sub 2} gas stream. The aim of this work was to evaluate the retention and elution of {sup 131}I samples produced at IPEN in several adsorbers as part of a project aiming the purification of these radioisotopes, allowing the labeling of biomolecules. Samples of {sup 131}I were used for retention and elution studies with the following adsorbers: commercial cartridges, anionic resin columns and cationic resin column. The results showed that Ag cartridges and anionic resins Dowex 1X8, Dowex 3 and IRA 400 had a great iodine retention but no elution after using specific eluents. The QMA light, acid alumina, neutral alumina and cationic resin Dowex 50WX4 showed high retention and elution and QMA plus and cationic resin Dowex 50WX8 and Dowex 50WX12 had a good retention but lower elution. Regarding to the better retention and elution, Ag cartridges and resins showed a higher percentage of iodine retention but lower elution yield and QMA light, acid and neutral alumina cartridges showed better results. (author)

Homogenization-based interval analysis for structural-acoustic problem involving periodical composites and multi-scale uncertain-but-bounded parameters.

Science.gov (United States)

Chen, Ning; Yu, Dejie; Xia, Baizhan; Liu, Jian; Ma, Zhengdong

2017-04-01

This paper presents a homogenization-based interval analysis method for the prediction of coupled structural-acoustic systems involving periodical composites and multi-scale uncertain-but-bounded parameters. In the structural-acoustic system, the macro plate structure is assumed to be composed of a periodically uniform microstructure. The equivalent macro material properties of the microstructure are computed using the homogenization method. By integrating the first-order Taylor expansion interval analysis method with the homogenization-based finite element method, a homogenization-based interval finite element method (HIFEM) is developed to solve a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters. The corresponding formulations of the HIFEM are deduced. A subinterval technique is also introduced into the HIFEM for higher accuracy. Numerical examples of a hexahedral box and an automobile passenger compartment are given to demonstrate the efficiency of the presented method for a periodical composite structural-acoustic system with multi-scale uncertain-but-bounded parameters.

Manager impact on retention of hospital staff: Part 2.

Science.gov (United States)

Taunton, R L; Krampitz, S D; Woods, C Q

1989-04-01

This is the second article in a two-part series based on a study of the impact of middle managers on retention of 71 hospital professionals. Research design, methods, and descriptive results were presented in Part 1 (March 1989). In Part 2, the impact of managers' motivation to manage, power, influence, and leadership style on retention is detailed. Recommendations for improving retention include interventions to increase employee job satisfaction and intent to stay, and to improve managers' performance and leadership.

The importance of localisation within 131J-retention measurements

International Nuclear Information System (INIS)

Greifeneder, G.; Aiginger, H.; Steger, F.; Flores, J.

1996-01-01

A widely used method to investigate thyroid gland carcinomas, but also disorders of the thyroid gland is the measurement of the 131 J-retention behaviour using a high-sensitivity whole-body counter (HWBC). Normally just the retention of oral administered Radioiodine is controlled. However, it is possible to visualize the distribution of 131 J (using a modified profilescantechnique) beside the retention in the human body and this provides much better information on human metabolism as will be demonstrated in the following

Urinary retention and post-void residual urine in men: separating truth from tradition.

Science.gov (United States)

Kaplan, Steven A; Wein, Alan J; Staskin, David R; Roehrborn, Claus G; Steers, William D

2008-07-01

The definitions of acute and chronic urinary retention remain empirical and subject to wide interpretation. Standardized criteria have not been established and many questions remain unanswered. Moreover, the definition of significant post-void residual urine is unclear. We reviewed several aspects of urinary retention that require clarification with the objective of stimulating discussion among urologists to establish an accurate and coherent definition of urinary retention and significant post-void residual urine, and clarify risk factors. A MEDLINE search for articles written in English and published before April 2007 was done using a list of terms related to urinary retention. Articles not directly relevant to urinary retention or post-void residual urine were excluded. The term urinary retention lacks precise clinical or urodynamic meaning. Use of this term to describe a symptom, a sign, and a condition further complicates the issue. Many factors can contribute to the development of retention, including bladder outlet obstruction, detrusor underactivity, and neurogenic bladder conditions. Community based studies and clinical trials in patients with benign prostatic enlargement and/or lower urinary tract symptoms yield different estimates of the incidence of retention and only provide information on the epidemiology of acute urinary retention. However, age, previous retention episodes, lower urinary tract symptoms, chronic inflammation, serum prostate specific antigen level, prostate size, and urodynamic variables appear to be predictors of acute urinary retention. Alpha-receptor antagonists and 5alpha-reductase inhibitors may be useful in preventing urinary retention episodes and progressive benign prostatic enlargement. Clinical trials on the short-term use of antimuscarinics have not provided evidence that these agents increase the risk of retention; data on longer term administration are needed. Clinicians are adopting less invasive approaches (eg

Krypton retention on solid adsorbents

International Nuclear Information System (INIS)

Monson, P.R. Jr.

1982-01-01

An experimental laboratory program was conducted to develop economical solid adsorbents for the retention of krypton from a dissolver off-gas stream. The study indicates that a solid adsorbent system is feasible and competitive with other developing systems which utilize fluorocarbon absorption nd cryogenic distillation. This technology may have potential applications not only in nuclear fuel reprocessing plants, but also in nuclear reactors and in environmental monitoring. Of the 13 prospective adsorbents evaluated with respect to adsorption capacity and cost, the commercially available hydrogen mordenite was the most cost-effective material at subambient temperatures (-40 0 to -80 0 C). Silver mordenite has a higher capacity for krypton retention, but is 50 times more expensive than hydrogen mordenite

The role of glucocorticoids in sodium retention in cirrhotic patients

DEFF Research Database (Denmark)

Hansen, Martin Højmark; Kristensen, Steffen Skott; Schaffalitzky de Muckadell, Ove B

2012-01-01

sodium retention evident in cirrhosis. The aim was to elucidate the role of glucocorticoids in sodium retention in decompensated cirrhotic patients. Methods. A randomized, double-blind, placebo-controlled, crossover study was performed in nine patients with alcoholic cirrhosis of the liver. A washout....... Conclusion. These results indicate that endogenous glucocorticoids contribute to the sodium retention in patients with alcoholic cirrhosis of the liver....

Employee Engagement as a Predictor of Seafarer Retention: A Study among Indian Officers

Directory of Open Access Journals (Sweden)

Yogendra Bhattacharya

2015-06-01

Full Text Available This paper is part of a study of employee engagement and its relationship with seafarer safety, performance and retention. This section focuses on the impact of seafarer turnover, identifies and understands drivers of retention and their relevance in shipping, and explores the relationship of engagement with retention. It determines the correlation between retention and engagement and analyses drivers of retention from the seafarer's perspective. It also identifies aspects of shipboard life that can contribute towards higher retention. The study confirms that engagement was significantly and positively related with retention levels, while factor analysis isolated six contributory factors. The study also reveals that retention levels of officers employed directly by ship owners and by managers did not differ significantly, nor did they significantly differ between senior and junior officers.

RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

Energy Technology Data Exchange (ETDEWEB)

Nelson, E

2007-02-28

The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

Proteinuric diseases with sodium retention: Is plasmin the link?

DEFF Research Database (Denmark)

Svenningsen, Per; Skøtt, Ole; Jensen, Boye L

2012-01-01

1. Sodium retention in disease states characterized by proteinuria, such as nephrotic syndrome, preeclampsia, and diabetic nephropathy, occurs through poorly understood mechanism(s). 2. In the nephrotic syndrome, data from experimental and clinical studies indicate that the sodium retention...... originates in the renal cortical collecting duct and involves hyper-activity of the epithelial sodium channel (ENaC). 3. The stimulus for the increased ENaC activity does not appear to involve any of the classical sodium retaining mechanisms, such as the renin-angiotensin-aldosterone system, arginine...... and diabetic nephropathy, which are also characterized by proteinuria and sodium retention. 7. In this review, we will examine the evidence for a role of urinary serine protease activity in the development of sodium and water retention in diseases characterised by proteinuria with a focus on the nephrotic...

[Mucoceles of the minor salivary glands. Extravasation mucoceles (mucus granulomas) and retention mucoceles (mucus retention cysts) (author's transl)].

Science.gov (United States)

Seifert, G; Donath, K; von Gumberz, C

1981-06-01

360 cases of salivary glands cysts (= 6%) were collected in the Salivary Glands Register (Institute of Pathology, University of Hamburg) from 1965 until 1979 among a total of 5739 register cases. 273 cases of the cystic lesions (= 76%) were mucoceles of the minor salivary glands. The analysis of these 273 cases revealed the following results: 1. Two types of mucoceles can be morphologically distinguished: extravasation mucoceles and retention mucoceles. 2. The extravasation mucocele is in our material (240 cases = 88.7%) the most frequent type of mucocele. The term "extravasation mucocele" of the anglo-american literature is identical with the term "mucus granuloma" ("Schleimgranulom") introduced by Hamperl (1932). 3. The main signs of the mucus granulomas are: predominant location (79%) at the lower lip, age peak in the 2nd decade and more frequent occurrence (in 60%) in the male sex. 4. Three stages of development can be distinguished in the pathogenesis of the mucus granulomas: an initial stage (interstitial mucus lakes), a resorption stage (mucus granulomas with macrophages, foam cells and foreign bodies giant cells) and a terminal stage with the development of a pseudocyst (capsule of collagen tissue, no epithelial demarcation). 5. The retention mucocele (synonym: mucus retention cyst) is a rare type of mucocele (33 cases = 11.3%). The main signs are: nearly equal occurrence in all oral regions, age peak in the 8th decade, moderate predominance of the female sex. 6. The retention mucoceles contain viscous mucous material, possess always an epithelial demarcation of the cysts differentiated analogous to the different segments of the salivary duct system and show as a rule no inflammatory reaction compared with the extravasation mucoceles. 7. Microtraumas and mucus congestions play the important role in the development of the extravasation mucocele. The final formation depends on the amount of the overflowed mucus and the intensity of the mucus phagocytosis. 8

Effects of variable attachment shapes and aligner material on aligner retention.

Science.gov (United States)

Dasy, Hiltrud; Dasy, Andreas; Asatrian, Greg; Rózsa, Noémi; Lee, Hao-Fu; Kwak, Jin Hee

2015-11-01

To evaluate the retention of four types of aligners on a dental arch with various attachments. For this study, three casts were manufactured, two of which contained attachments (ellipsoid and beveled), and one without any attachments to serve as a control. Four types of aligners were thermoformed: Clear-Aligner (CA)-soft, CA-medium, and CA-hard, with various thicknesses, and Essix ACE. Measurements of vertical displacement force during aligner removal were performed with the Gabo Qualimeter Eplexor. Means and standard deviations were next compared between different aligner thicknesses and attachment shapes. CA-soft, CA-medium, and CA-hard did not present a significant increase in retention, except when used in the presence of attachments. Additionally, CA-medium and CA-hard required significantly more force for removal. Essix ACE demonstrated a significant decrease in retention when used with ellipsoid attachments. The force value for Essix ACE removal from the cast with beveled attachments was comparable to that of CA-medium. Forces for aligner removal from the model without attachments showed a linear trend. Essix ACE did not show a continuous increase in retention for each model. Overall, ellipsoid attachments did not present a significant change in retention. In contrast, beveled attachments improved retention. Ellipsoid attachments had no significant influence on the force required for aligner removal and hence on aligner retention. Essix ACE showed significantly less retention than CA-hard on the models with attachments. Furthermore, beveled attachments were observed to increase retention significantly, compared with ellipsoid attachments and when using no attachments.

Distribution of pre-course BLS/AED manuals does not influence skill acquisition and retention in lay rescuers: a randomised study.

Science.gov (United States)

Papadimitriou, Lila; Xanthos, Theodoros; Bassiakou, Eleni; Stroumpoulis, Kostantinos; Barouxis, Dimitrios; Iacovidou, Nicolleta

2010-03-01

The present study aims to investigate whether the distribution of the Basic Life Support and Automated External Defibrillation (BLS/AED) manual, 4 weeks prior to the course, has an effect on skill acquisition, theoretical knowledge and skill retention, compared with courses where manuals were not distributed. A total of 303 laypeople were included in the present study. The courses were randomised with sealed envelopes in 12 courses, where manuals were distributed to participants (group A) and in 12 courses, where manuals were not distributed to participants (group B). The participants were formally evaluated at the end of the course, and at 1, 3 and 6 months after each course. The evaluation procedure was the same at all time intervals and consisted of two distinct parts: a written test and a simulated cardiac arrest scenario. No significant difference was observed between the two groups in skill acquisition at the time of initial training. Furthermore, there was no significant difference between the groups in performing BLS/AED skills at 1, 3 and 6 months after initial training. Theoretical knowledge in either group at the specified time intervals did not exhibit any significant difference. Significant deterioration of skills was observed in both groups between initial training and at 1 month after the course, as well as between the first and third month after the course. The present study shows that distribution of BLS/AED manuals 1 month prior to the course has no effect on theoretical knowledge, skill acquisition and skill retention in laypeople. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

The effects of sampling on the efficiency and accuracy of k-mer indexes: Theoretical and empirical comparisons using the human genome.

Science.gov (United States)

Almutairy, Meznah; Torng, Eric

2017-01-01

One of the most common ways to search a sequence database for sequences that are similar to a query sequence is to use a k-mer index such as BLAST. A big problem with k-mer indexes is the space required to store the lists of all occurrences of all k-mers in the database. One method for reducing the space needed, and also query time, is sampling where only some k-mer occurrences are stored. Most previous work uses hard sampling, in which enough k-mer occurrences are retained so that all similar sequences are guaranteed to be found. In contrast, we study soft sampling, which further reduces the number of stored k-mer occurrences at a cost of decreasing query accuracy. We focus on finding highly similar local alignments (HSLA) over nucleotide sequences, an operation that is fundamental to biological applications such as cDNA sequence mapping. For our comparison, we use the NCBI BLAST tool with the human genome and human ESTs. When identifying HSLAs, we find that soft sampling significantly reduces both index size and query time with relatively small losses in query accuracy. For the human genome and HSLAs of length at least 100 bp, soft sampling reduces index size 4-10 times more than hard sampling and processes queries 2.3-6.8 times faster, while still achieving retention rates of at least 96.6%. When we apply soft sampling to the problem of mapping ESTs against the genome, we map more than 98% of ESTs perfectly while reducing the index size by a factor of 4 and query time by 23.3%. These results demonstrate that soft sampling is a simple but effective strategy for performing efficient searches for HSLAs. We also provide a new model for sampling with BLAST that predicts empirical retention rates with reasonable accuracy by modeling two key problem factors.

Retrieval practice in the form of online homework improved information retention more when spaced 5 days rather than 1 day after class in two physiology courses.

Science.gov (United States)

Cadaret, Caitlin N; Yates, Dustin T

2018-06-01

Studies have shown that practicing temporally spaced retrieval of previously learned information via formal assessments increases student retention of the information. Our objective was to determine the impact of online homework administered as a first retrieval practice 1 or 5 days after introduction of physiology topics on long-term information retention. Students in two undergraduate courses, Anatomy and Physiology (ASCI 240) and Animal Physiological Systems (ASCI 340), were presented with information on a specific physiological system during each weekly laboratory and then completed an online homework assignment either 1 or 5 days later. Information retention was assessed via an in-class quiz the following week and by a comprehensive final exam at semester's end (4-13 wk later). Performance on homework assignments was generally similar between groups for both courses. Information retention at 1 wk did not differ due to timing of homework in either course. In both courses, however, students who received homework 5 days after class performed better on final exam questions relevant to that week's topic compared with their day 1 counterparts. These findings indicate that the longer period between introducing physiology information in class and assigning the first retrieval practice was more beneficial to long-term information retention than the shorter period, despite seemingly equivalent benefits in the shorter term. Since information is typically forgotten over time, we speculate that the longer interval necessitates greater retrieval effort in much the same way as built-in desirable difficulties, thus allowing for stronger conceptual connections and deeper comprehension.

Learning and retention of quantum concepts with different teaching methods

Science.gov (United States)

Deslauriers, Louis; Wieman, Carl

2011-06-01

We measured mastery and retention of conceptual understanding of quantum mechanics in a modern physics course. This was studied for two equivalent cohorts of students taught with different pedagogical approaches using the Quantum Mechanics Conceptual Survey. We measured the impact of pedagogical approach both on the original conceptual learning and on long-term retention. The cohort of students who had a very highly rated traditional lecturer scored 19% lower than the equivalent cohort that was taught using interactive engagement methods. However, the amount of retention was very high for both cohorts, showing only a few percent decrease in scores when retested 6 and 18 months after completion of the course and with no exposure to the material in the interim period. This high level of retention is in striking contrast to the retention measured for more factual learning from university courses and argues for the value of emphasizing conceptual learning.

Evaluation of electrical impedance ratio measurements in accuracy of electronic apex locators

Directory of Open Access Journals (Sweden)

Pil-Jong Kim

2015-05-01

Full Text Available Objectives The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL. Materials and Methods The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data acquired were plotted to identify correlations between impedance and log-scaled frequency. The accuracy of the impedance ratio method used to detect the apical constriction (APC in most EALs was evaluated using linear ramp function fitting. Changes of impedance ratios for various frequencies were evaluated for a variety of file positions. Results Among the ten papers selected in the search process, the first-order equations between log-scaled frequency and impedance were in the negative direction. When the model for the ratios was assumed to be a linear ramp function, the ratio values decreased if the file went deeper and the average ratio values of the left and right horizontal zones were significantly different in 8 out of 9 studies. The APC was located within the interval of linear relation between the left and right horizontal zones of the linear ramp model. Conclusions Using the ratio method, the APC was located within a linear interval. Therefore, using the impedance ratio between electrical impedance measurements at different frequencies was a robust method for detection of the APC.

Secrets of Retention

Science.gov (United States)

Poliniak, Susan

2012-01-01

Recruiting students is one thing, but keeping them in a chorus, orchestra, or band is another. Although a music director has no control over some variables, there is much that can be done to help students to stay. Several experts share their advice on retention. One expert said a teacher's own attitude and classroom strategies may be two of the…

[S1 Herpes zoster localization: acute urinary retention in woman].

Science.gov (United States)

Vella, Marco; Mastrocinque, Giuseppe; Romeo, Salvatore; Giammanco, Giovanni; Melloni, Darwin

2011-01-01

Acute urinary retention in women is rare. The varicella-zoster virus causes inflammatory lesions of the sensory-root ganglions, meninges and, less frequently, spinal cord. Herpes zoster has been reported to affect, although rarely, lower urinary tract innervations, and acute urinary retention can be thought to occur in the presence of sacral dermatome involvement. Usually it is located in S2-4 dermatome and the prognosis for acute urinary retention is benign resolving in about 20 days. We present a case in which the S1 dermatome was involved and acute urinary retention developed. After 10 days of specific therapy and self-catheterization the problem resolved.

Knowledge-based errors in anesthesia: a paired, controlled trial of learning and retention.

Science.gov (United States)

Goldhaber-Fiebert, Sara N; Goldhaber-Fiebert, Jeremy D; Rosow, Carl E

2009-01-01

Optimizing patient safety by improving the training of physicians is a major challenge of medical education. In this pilot study, we hypothesized that a brief lecture, targeted to rare but potentially dangerous situations, could improve anesthesia practitioners' knowledge levels with significant retention of learning at six months. In this paired controlled trial, anesthesia residents and attending physicians at Massachusetts General Hospital took the same 14-question multiple choice examination three times: at baseline, immediately after a brief lecture, and six months later. The lecture covered material on seven "intervention" questions; the remaining seven were "control" questions. The authors measured immediate knowledge acquisition, defined as the change in percentage of correct answers on intervention questions between baseline and post-lecture, and measured learning retention as the difference between baseline and six months. Both measurements were corrected for change in performance on control questions. Fifty of the 89 subjects completed all three examinations. The post-lecture increase in percentage of questions answered correctly, adjusted for control, was 22.2% [95% confidence interval (CI) 16.0-28.4%; P learning at six months. Exposing residents or other practitioners to this type of inexpensive teaching intervention may help them to avoid preventable uncommon errors that are rooted in unfamiliarity with the situation or the equipment. The methods used for this study may also be applied to compare the effect of various other teaching modalities while, at the same time, preserving participant anonymity and making adjustments for ongoing learning.

Measuring in-stream retention of copper by means of constant-rate additions.

Science.gov (United States)

Serra, A; Guasch, H; Martí, E; Geiszinger, A

2009-06-01

Human practices entail inputs of nutrients and toxicants such as heavy metals to the fluvial ecosystems. While nutrient dynamics in fluvial ecosystems have been widely studied for over three decades, dynamics of toxicants still remain unclear. In this investigation, the nutrient spiraling concept and associated methodologies to quantify nutrient retention in streams were applied to study copper (Cu) dynamics in streams. The present study aimed to quantify total dissolved Cu retention using a simplified system of indoor channels colonized with fluvial biofilms. Cu retention was studied at sub-toxic concentrations to avoid negative/lethal effects on biota. In addition, Cu retention was compared with retention estimates of a macronutrient, phosphate (PO(4)(3-)), which has been widely studied within the context of the nutrient spiraling concept. The methodology used allowed a successful quantification of Cu and PO(4)(3-) retention. The results showed higher retention efficiency for PO(4)(3-) than for Cu. The biofilm played a key role in retaining both solutes. Although retention efficiency for both solutes was higher in the experiments with colonized substrata compared to uncolonized substrata, we found a positive relationship between uptake rate and chlorophyll-a only for PO(4)(3-). Finally, retention efficiency for both solutes was influenced by water discharge, showing lower retention efficiencies under higher flow conditions. These results suggest that the fate and toxic effects of copper on stream biota may be strongly influenced by the prevailing environmental conditions. Our results indicate that the experimental approach considered can provide new insights into the investigation of retention of toxic compounds in fluvial systems and their controlling mechanisms.

Validation of Models Used to Inform Colorectal Cancer Screening Guidelines: Accuracy and Implications.

Science.gov (United States)

Rutter, Carolyn M; Knudsen, Amy B; Marsh, Tracey L; Doria-Rose, V Paul; Johnson, Eric; Pabiniak, Chester; Kuntz, Karen M; van Ballegooijen, Marjolein; Zauber, Ann G; Lansdorp-Vogelaar, Iris

2016-07-01

Microsimulation models synthesize evidence about disease processes and interventions, providing a method for predicting long-term benefits and harms of prevention, screening, and treatment strategies. Because models often require assumptions about unobservable processes, assessing a model's predictive accuracy is important. We validated 3 colorectal cancer (CRC) microsimulation models against outcomes from the United Kingdom Flexible Sigmoidoscopy Screening (UKFSS) Trial, a randomized controlled trial that examined the effectiveness of one-time flexible sigmoidoscopy screening to reduce CRC mortality. The models incorporate different assumptions about the time from adenoma initiation to development of preclinical and symptomatic CRC. Analyses compare model predictions to study estimates across a range of outcomes to provide insight into the accuracy of model assumptions. All 3 models accurately predicted the relative reduction in CRC mortality 10 years after screening (predicted hazard ratios, with 95% percentile intervals: 0.56 [0.44, 0.71], 0.63 [0.51, 0.75], 0.68 [0.53, 0.83]; estimated with 95% confidence interval: 0.56 [0.45, 0.69]). Two models with longer average preclinical duration accurately predicted the relative reduction in 10-year CRC incidence. Two models with longer mean sojourn time accurately predicted the number of screen-detected cancers. All 3 models predicted too many proximal adenomas among patients referred to colonoscopy. Model accuracy can only be established through external validation. Analyses such as these are therefore essential for any decision model. Results supported the assumptions that the average time from adenoma initiation to development of preclinical cancer is long (up to 25 years), and mean sojourn time is close to 4 years, suggesting the window for early detection and intervention by screening is relatively long. Variation in dwell time remains uncertain and could have important clinical and policy implications. © The

Variations in plasma ceruloplasmin and whole body retention of 67Cu in guinea pigs recovering from vitamin C deficiency

International Nuclear Information System (INIS)

Hosestenbach, R.D. Jr.; Harris, E.D.

1991-01-01

Parallels may be drawn between the symptoms of scurvy and copper deficiency. This realization led the authors to examine the effects of ascorbic acid supplementation on plasma ceruloplasmin and whole body turnover of copper in scorbutic guinea pigs. Weanling guinea pigs were fed an ascorbate free semi-purified diet for 10-14 days then randomly divided into 3 treatment groups receiving oral supplementation of ascorbic acid at levels: deficient, normal, and excess. In two experiments with different groups of animals, the plasma ceruloplasmin IU, measured by p-phenylenediamine oxidase activity, was significantly higher in the deficient groups, 53.5 ± 7.7 and 41.2 ± 9.2, than in the normal and excess groups, 18.3 ± 7.7, 21.6 ± 2.6 and 30.2 ± 9.2, 18.3 ± 2.6, respectively. 67 Cu was administered intraperitoneally and whole body gamma radiation was measured at 24 h intervals to determine excretion and retention rates of the 3 treatment groups. A higher retention of 67 Cu was observed in the deficient group, t1/2 = 4.8 days compared to 2.6 and 1.6 in the normal and excess groups, respectively. The affect of ascorbic acid on the regulatory mechanism of copper retention, either directly or indirectly, and the increase in plasma ceruloplasmin activity indicates ascorbic acid may perform a functional role in copper utilization in a biological system

Improving orbit prediction accuracy through supervised machine learning

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Peng, Hao; Bai, Xiaoli

2018-05-01

Due to the lack of information such as the space environment condition and resident space objects' (RSOs') body characteristics, current orbit predictions that are solely grounded on physics-based models may fail to achieve required accuracy for collision avoidance and have led to satellite collisions already. This paper presents a methodology to predict RSOs' trajectories with higher accuracy than that of the current methods. Inspired by the machine learning (ML) theory through which the models are learned based on large amounts of observed data and the prediction is conducted without explicitly modeling space objects and space environment, the proposed ML approach integrates physics-based orbit prediction algorithms with a learning-based process that focuses on reducing the prediction errors. Using a simulation-based space catalog environment as the test bed, the paper demonstrates three types of generalization capability for the proposed ML approach: (1) the ML model can be used to improve the same RSO's orbit information that is not available during the learning process but shares the same time interval as the training data; (2) the ML model can be used to improve predictions of the same RSO at future epochs; and (3) the ML model based on a RSO can be applied to other RSOs that share some common features.

Strategies to improve retention in randomised trials

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Brueton, Valerie C; Tierney, Jayne; Stenning, Sally; Harding, Seeromanie; Meredith, Sarah; Nazareth, Irwin; Rait, Greta

2013-01-01

Background Loss to follow-up from randomised trials can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to reduce loss to follow-up and improve retention but few have been formally evaluated. Objectives To quantify the effect of strategies to improve retention on the proportion of participants retained in randomised trials and to investigate if the effect varied by trial strategy and trial setting. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PreMEDLINE, EMBASE, PsycINFO, DARE, CINAHL, Campbell Collaboration's Social, Psychological, Educational and Criminological Trials Register, and ERIC. We handsearched conference proceedings and publication reference lists for eligible retention trials. We also surveyed all UK Clinical Trials Units to identify further studies. Selection criteria We included eligible retention trials of randomised or quasi-randomised evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance. Data collection and analysis We contacted authors to supplement or confirm data that we had extracted. For retention trials, we recorded data on the method of randomisation, type of strategy evaluated, comparator, primary outcome, planned sample size, numbers randomised and numbers retained. We used risk ratios (RR) to evaluate the effectiveness of the addition of strategies to improve retention. We assessed heterogeneity between trials using the Chi2 and I2 statistics. For main trials that hosted retention trials, we extracted data on disease area, intervention, population, healthcare setting, sequence generation and allocation concealment. Main results We identified 38 eligible retention trials. Included trials evaluated six broad types of strategies to improve retention. These

Mate retention tactics in Spain: personality, sex differences, and relationship status.

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de Miguel, Adelia; Buss, David M

2011-06-01

Mate retention is an important problem in romantic relationships because of mate poachers, infidelity, and the risk of outright defection. The current study (N=892) represents the first study of mate retention tactics conducted in Spain. We tested hypotheses about the effects of gender, relationship commitment status, and personality on mate retention tactics. Women and men differed in the use of resource display, appearance enhancement, intrasexual violence, and submission/self-abasement as mate retention tactics. Those in more committed relationships reported higher levels of resource display, appearance enhancement, love, and verbal signals of possession. Those in less committed relationships more often reported intentionally evoking jealousy in their partner as a mate retention tactic. Personality characteristics, particularly Neuroticism and Agreeableness, correlated in coherent ways with mate retention tactics, supporting two evolution-based hypotheses. Discussion focuses on the implications, future research directions, and interdisciplinary syntheses emerging between personality and social psychology and evolutionary psychology. © 2011 The Authors. Journal of Personality © 2011, Wiley Periodicals, Inc.

Kinetics of distribution and retention of /sup 3/H-oestradiol-17. beta. in rat tissues: a comparative study with free oestradiol and after its incorporation into liposomes

Energy Technology Data Exchange (ETDEWEB)

Jehan, Q; Srivasta, S; Setty, B S [Central Drug Research Inst., Lucknow (India). Div. of Endocrinology; Akhlaq, M; Ahmad, A [Central Drug Research Inst., Lucknow (India)

1982-01-01

With a view to impart selective uptake of estrogen by the target tissues of rat, liposomes in which (6,7-/sup 3/H) estradiol-17..beta.. constituted a part of lipid bilayer were used as carriers of the hormone. The distribution and retention of the radioactivity was determined in blood plasma, uterus, liver, kidney, spleen and leg muscle of ovariectomized rat at different time intervals up to 72 hr following a single intravenous injection of free estradiol (1.61 ..mu..Ci) or an equivalent amount of liposomal estradiol. When free estradiol was administered, uterus showed peak amount of radioactivity between 30 min to 2 hr and remained high up to 6 hr. In the other tissues examined, maximum amount of radioactivity was seen at 15 min followed by a marked fall at 30 min and also at other subsequent intervals. The pattern of uptake and retention of radioactivity after administration of liposomal estradiol was not much different from that of free estradiol between 1 and 6 hr. A moderate increase in the amount of radioactivity in the nongenital tissues at 24 hr was the only difference noticed with liposomal estradiol. It is concluded that targeting of estradiol preferentially to the uterus could not be achieved through a liposomal delivery system.

One process is not enough! A speed-accuracy tradeoff study of recognition memory.

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Boldini, Angela; Russo, Riccardo; Avons, S E

2004-04-01

Speed-accuracy tradeoff (SAT) methods have been used to contrast single- and dual-process accounts of recognition memory. In these procedures, subjects are presented with individual test items and are required to make recognition decisions under various time constraints. In this experiment, we presented word lists under incidental learning conditions, varying the modality of presentation and level of processing. At test, we manipulated the interval between each visually presented test item and a response signal, thus controlling the amount of time available to retrieve target information. Study-test modality match had a beneficial effect on recognition accuracy at short response-signal delays (deep than from shallow processing at study only at relatively long response-signal delays (> or =300 msec). The results are congruent with views suggesting that both fast familiarity and slower recollection processes contribute to recognition memory.

Factors for lifelong job retention among Swiss radiographers

International Nuclear Information System (INIS)

Lehmann, P.; Meystre, N. Richli; Mamboury, N.

2015-01-01

In Switzerland, a shortage of radiographers in the three radiology domains, radio-diagnostic, radiotherapy and nuclear medicine, is supposed to increase in the upcoming years. As job satisfaction has been shown to contribute to workplace retention, one purpose of the study was to explore the relationship between workplace retention and duration in the profession with job satisfaction. The study was based on two surveys. The institutional survey was addressed to all chiefs of radiology units in hospitals and ambulatory institutes (340, response rate 48%). All radiographers were asked to complete the individual survey (3000, response rate 25%). Two thirds of radiographers had been employed for five or more years in the same workplace, and nearly half intended to stay for 10 more years. The professional lifespan of radiographers is estimated to be approximately 27 years. 75% expressed their satisfaction with key aspects of professional activity, including the content of the work, autonomy, technology and their relationships with professionals and patients. These factors were not linked to a particular workplace, but to the profession itself. The radiographers build their own propitious work environment, even if salary and recognition by physicians are contributing to their dissatisfaction. The retention in the profession, consolidated by a high level of satisfaction, is an essential feature for a workforce policy. However, active measures for reinforcing retention are still necessary when considering that a lifelong career needs challenges and rewards. Additionally, the retention rate does not provide a guarantee adequacy for the future projected needs in the profession. - Highlights: • Retention in the profession, with a high level of satisfaction, is a major point for a workforce policy. • Job satisfaction of radiographers is not linked to a particular workplace, but to the profession itself. • The professional lifespan of radiographers in Switzerland is

Lymphatic involvement in the histopathogenesis of mucous retention cyst.

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Kundu, Sukalyan; Cheng, Jun; Maruyama, Satoshi; Suzuki, Makoto; Kawashima, Hiroyuki; Saku, Takashi

2007-01-01

Mucous retention cyst results from extravasation of saliva. Our intent was to study the role of lymphatics in its pathogenesis. Twenty-three surgical specimens of mucous retention cyst of the lip were examined for involvement of lymphatic vessels by a comparative immunohistochemical demonstration of lymphatic and blood vascular endothelial cells, as well as lymphatic and salivary contents. Mucous retention cysts were histopathologically classified into three stages: early, intermediate, and advanced. In the early stage, there was diffuse extravasation of mucous material in the interstitium of the lamina propria or the submucosal layer of the oral mucosa. In the intermediate stage, lymphatics, which were clearly revealed and immunohistochemically distinguished from blood vessels by monoclonal antibody D2-40, were dilated and finally ruptured, leaving fragments of lymphatic walls in the periphery of mucous pools. In the advanced stage, thick cyst walls of granulation tissue were formed around mucous retention. Lymphatics were no longer involved in the granulation tissue wall, which was actively driven by blood vessel formation. The results suggest that the lymphatic rupture seems to contribute to the enlargement in the pathogenesis of mucous retention cyst.

13 CFR 120.861 - Job creation or retention.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be specified...

Acute urinary retention attributable to sacral herpes zoster.

Science.gov (United States)

Acheson, J; Mudd, D

2004-11-01

Acute urinary retention in women is uncommon. A 63 year old woman presented with suprapubic pain, a palpable bladder, and multiple grouped vesicles on the right buttock. Catheterisation showed a residual of 2000 ml. A case is reported of acute urinary retention secondary to herpes zoster infection of the sacral nerves (S2-4).

Retention of zinc and calcium from the human colon

International Nuclear Information System (INIS)

Sandstroem, B.C.; Cederblad, A.; Kivistoe, B.S.; Stenquist, B.; Andersson, H.

1986-01-01

Colonic retention of zinc and calcium was studied after installation during colonoscopy of 30 mumol of zinc and 6.4 mmol of calcium labeled with 65 Zn and 47 Ca, and measurement of the whole-body retention of the radionuclides. After cecal installation in nine patients, retention (day 13) of zinc was 3.5 +/- 2.1% (mean +/- SD) and of calcium 3.5 +/- 2.7%. The calculated mean absorption was 4.1% for zinc and 14.1% for calcium. Application at the hepatic flexure in four patients resulted in a mean retention (day 13) of 1.2% for zinc and 0.6% for calcium. Under prevailing conditions, colonic absorption of zinc is relatively small, compared to the uptake after oral administration. Colonic absorption of calcium could, however, account for a substantial part of the total calcium uptake

Patient retention at dental school clinics: a marketing perspective.

Science.gov (United States)

Makarem, Suzanne C; Coe, Julie M

2014-11-01

The purpose of this investigation was to examine the drivers of patient retention at dental school clinics from a services marketing perspective. An analysis of patient characteristics at Virginia Commonwealth University School of Dentistry, screened between August 2010 and July 2011 (N=3604), was performed using descriptive statistics, cross-tabulations, and a binary logistic regression. The main findings were that 42 percent of patients in the study were retained and that no response to communication efforts (36 percent) and financial problems (28 percent) constituted the most common reasons for non-retention. Older age, having insurance, and living within a sixty-mile radius were significant drivers of retention (pskills to better service them, and consequently increasing retention. This will lead to providing a continuum of care and student education and to ensuring the sustainability and quality of the school's educational programs.

Short-term Retention of Relational Memory in Amnesia Revisited: Accurate Performance Depends on Hippocampal Integrity

Directory of Open Access Journals (Sweden)

Lydia T.S. Yee

2014-01-01

Full Text Available Traditionally, it has been proposed that the hippocampus and adjacent medial temporal lobe cortical structures are selectively critical for long-term declarative memory, which entails memory for inter-item and item-context relationships. Whether the hippocampus might also contribute to short-term retention of relational memory representations has remained controversial. In two experiments, we revisit this question by testing memory for relationships among items embedded in scenes using a standard working memory trial structure in which a sample stimulus is followed by a brief delay and the corresponding test stimulus. In each experimental block, eight trials using different exemplars of the same scene were presented. The exemplars contained the same items but with different spatial relationships among them. By repeating the pictures across trials, any potential contributions of item or scene memory to performance were minimized, and relational memory could be assessed more directly than has been done previously. When test displays were presented, participants indicated whether any of the item-location relationships had changed. Then, regardless of their responses (and whether any item did change its location, participants indicated on a forced-choice test, which item might have moved, guessing if necessary. Amnesic patients were impaired on the change detection test, and were frequently unable to specify the change after having reported correctly that a change had taken place. Comparison participants, by contrast, frequently identified the change even when they failed to report the mismatch, an outcome that speaks to the sensitivity of the change specification measure. These results confirm past reports of hippocampal contributions to short-term retention of relational memory representations, and suggest that the role of the hippocampus in memory has more to do with relational memory requirements than the length of a retention interval.

Wind Information Uplink to Aircraft Performing Interval Management Operations

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Ahmad, Nashat N.; Barmore, Bryan E.; Swieringa, Kurt A.

2016-01-01

Interval Management (IM) is an ADS-B-enabled suite of applications that use ground and flight deck capabilities and procedures designed to support the relative spacing of aircraft (Barmore et al., 2004, Murdoch et al. 2009, Barmore 2009, Swieringa et al. 2011; Weitz et al. 2012). Relative spacing refers to managing the position of one aircraft to a time or distance relative to another aircraft, as opposed to a static reference point such as a point over the ground or clock time. This results in improved inter-aircraft spacing precision and is expected to allow aircraft to be spaced closer to the applicable separation standard than current operations. Consequently, if the reduced spacing is used in scheduling, IM can reduce the time interval between the first and last aircraft in an overall arrival flow, resulting in increased throughput. Because IM relies on speed changes to achieve precise spacing, it can reduce costly, low-altitude, vectoring, which increases both efficiency and throughput in capacity-constrained airspace without negatively impacting controller workload and task complexity. This is expected to increase overall system efficiency. The Flight Deck Interval Management (FIM) equipment provides speeds to the flight crew that will deliver them to the achieve-by point at the controller-specified time, i.e., assigned spacing goal, after the target aircraft crosses the achieve-by point (Figure 1.1). Since the IM and target aircraft may not be on the same arrival procedure, the FIM equipment predicts the estimated times of arrival (ETA) for both the IM and target aircraft to the achieve-by point. This involves generating an approximate four-dimensional trajectory for each aircraft. The accuracy of the wind data used to generate those trajectories is critical to the success of the IM operation. There are two main forms of uncertainty in the wind information used by the FIM equipment. The first is the accuracy of the forecast modeling done by the weather

Specialized moisture retention eyewear for evaporative dry eye.

Science.gov (United States)

Waduthantri, Samanthila; Tan, Chien Hua; Fong, Yee Wei; Tong, Louis

2015-05-01

To evaluate the suitablity of commercially available moisture retention eyewear for treating evaporative dry eye. Eleven patients with evaporative dry eyes were prescibed moisture retention eyewear for 3 months in addition to regular lubricant eye drops. Frequency and severity of dry eye symptoms, corneal fluorescein staining and tear break up time (TBUT) were evaluated at baseline and 3-month post-treatment. Main outcome measure was global symptom score (based on severity and frequency of dry eye symptoms on a visual analog scale) and secondary outcomes were changes in sectoral corneal fluorescein staining and tear break up time (TBUT) from pre-treatment level. There was a significant improvement in dry eye symptoms after using moisture retention eyewear for 3 months (p eyes improved significantly (p dry eye symptoms in windy, air-conditioned environments or when doing vision-related daily tasks. This study shows that moisture retention eyewear might be a valuable adjunct in management of evaporative dry eye and this new design of commercially available eyewear could have a good acceptability rate.

Artisan retention in an organisation in South Africa

Directory of Open Access Journals (Sweden)

Lariska van Rooyen

2010-11-01

Research purpose: The objective of this study was to investigate the factors that are important for artisan retention at a South African organisation. Motivation for the study: Organisations that employ artisans need to understand what the main reasons are for keeping or losing artisans from the perspective of the artisans themselves. This information can be used to plan and implement interventions to deal with artisan retention in organisations. Research design, approach and method: A qualitative design was used and a purposive sample was taken (n = 14. A biographical questionnaire was administered and semi-structured interviews were conducted to gather data from artisans. Main findings: Remuneration had the highest rank of all the factors for the retention of artisans, closely followed by development opportunities. Other factors that were perceived as important for artisan retention included equality, recognition, management and the working environment, and working relationships. Practical implications: Organisations that employ artisans should especially attend to their remuneration and development opportunities. Contribution: The results of this study add to the knowledge of why artisans remain with a specific organisation.

Monte Carlo study of quantum number retention in hadron jets

International Nuclear Information System (INIS)

Hayward, S.K.; Weiss, N.

1992-01-01

We present a Monte Carlo study in which we used weighted quantum numbers of hadron jets in an attempt to identify the parent parton of these jets. Two-jet events produced by e + e- annihilation were studied using the Lund Monte Carlo program. It was found that the sign of the charge of the leading parton could be determined in a majority of events and that the quark jet could be distinguished from the antiquark jet in a majority of events containing baryons. A careful selection of a subset of the events by making cuts on the value of these weighted quantum numbers increased significantly the accuracy with which both the charge and the baryon number of the leading parton could be determined. Some success was also made in differentiating light-quark from heavy-quark events and in determining the leading quark flavor in the light-quark events. Unfortunately quantum number retention does not differentiate gluon jets from quark jets. The consequences of this for three-jet events and for jet identification in other reactions is discussed

Recruitment and Retention of New Emergency Medical Technician (EMT)-Basics and Paramedics.

Science.gov (United States)

Chapman, Susan A; Crowe, Remle P; Bentley, Melissa A

2016-12-01

The purpose of this paper is to describe factors important for the recruitment and retention of Emergency Medical Technician (EMT)-Basics and EMT-Paramedics new to the Emergency Medical Services (EMS) field (defined as two years or less of EMS employment) through an analysis of 10 years of Longitudinal EMT Attributes and Demographic Study (LEADS) data. Data were obtained from 10 years of LEADS surveys (1999-2008). Individuals new to the profession were identified through responses to a survey item. Their responses were analyzed using weights reflecting each individual's probability of selection. Means, proportions, and 95% confidence intervals (CIs) were determined and used to identify statistically significant differences. There were few changes in the demographic characteristics of new EMT-Basics and Paramedics across survey years. New EMT-Basics tended to be older and less likely to have a college degree than new EMT-Paramedics. More new EMT-Basics than EMT-Paramedics worked in rural areas and small towns and reported that they were working as a volunteer. There were differences between new EMT-Basics and EMT-Paramedics in several of the reasons for entering the profession and in facets of job satisfaction. The findings provide guidance for recruiters, educators, employers, and governmental EMS policy organizations and will provide better insight into how to attract and retain new entrants to the field. Chapman SA , Crowe RP , Bentley MA . Recruitment and retention of new Emergency Medical Technician (EMT)-Basics and Paramedics. Prehosp Disaster Med. 2016;31(Suppl. 1):s70-s86.

[Academic stress, desertion, and retention strategies for students in higher education].

Science.gov (United States)

Suárez-Montes, Nancy; Díaz-Subieta, Luz B

2015-04-01

A systematic review was performed to specify the characteristics of academic stress that affect the mental health of the university population. To do this, recent publications regarding academic stress, student desertion, and retention strategies were examined. Throughout this text, we present the results of the review in terms of the definitions of academic stress, student desertion, and retention strategies. In the same way, we examine the interpretative models with regard to student desertion and approach retention strategies in higher education. We also review retention experiences of several other countries. In terms of Colombia, we present aspects related to student desertion and retention programs from the point of view of the National Ministry of Education and from the experience of some universities with consolidated programs.

Employee satisfaction and employee retention: catalysts to patient satisfaction.

Science.gov (United States)

Collins, Kevin S; Collins, Sandra K; McKinnies, Richard; Jensen, Steven

2008-01-01

Over the last few years, most health care facilities have become intensely aware of the need to increase patient satisfaction. However, with today's more consumer-driven market, this can be a daunting task for even the most experienced health care manager. Recent studies indicate that focusing on employee satisfaction and subsequent employee retention may be strong catalysts to patient satisfaction. This study offers a review of how employee satisfaction and retention correlate with patient satisfaction and also examines the current ways health care organizations are focusing on employee satisfaction and retention.

Preliminary steps towards assessing aerosol retention in the break stage of a dry steam generator during severe accident SGTR sequences

International Nuclear Information System (INIS)

Herranz, L.E.; Lopez del Pra, C.; Sanchez Velasco, F.J.

2006-01-01

Severe accidents SGTR sequences are identified as major contributors to risk of PWRs. Their relevance lies in the potential radioactive release from reactor coolant system to the environment. Lack of knowledge on the source term attenuation capability of the steam generator has avoided its consideration in probabilistic safety studies and severe accident management guidelines. This paper describes a research program presently under way on the aerosol retention in the nearby of the tube breach within the secondary side of the steam generation in the absence of water. Its development has been internationally framed within the EU-SGTR and the ARTIST program. Experimental activities are focused on setting up a reliable database in which the influence of gas mass flow rate, breach configuration and particle nature in the aerosol retention are properly considered. Theoretical activities are aimed at developing a predictive tool (ARISG) capable of assessing source term attenuation in the scenario with reasonable accuracy. Given the major importance of jet aerodynamics, 3D CFD analyses are being conducted to assist both test interpretation and model development. (author)

Recycling retention functions

International Nuclear Information System (INIS)

Skrable, K.W.; Chabot, G.E.; Johnson, M.H.

1981-01-01

Beginning with the concept of any number of physiologically meaningful compartments that recycle material with a central extracellular fluid compartment and considering various excretion pathways, we solve the differential equations describing the kinetics by the method of Laplace to obtain concise algebraic expressions for the retentions. These expressions contain both fundamental and eigenvalue rate constants; the eigenvalue rate constants are obtained from the solution of a polynomial incorporating the fundamental rate constants. Mathematically exact expressions that predict the biodistribution resulting from continuous uptakes are used to obtain very simple mathematically exact steady state expressions as well as approximate expressions applicable to any time. These steady state and approximate expressions contain only the fundamental rate constants; also, they include a recycling factor that describes the increase in the biodistributions because of recycling. To obtain the values of the fundamental rate constants, short term kinetics studies along with data on the long term distributions are suggested. Retention functions obtained in this way predict both the short term and long term distributions; they therefore are useful in the interpretation of bioassay data and in the estimation of internal doses

Retention of minority participants in clinical research studies.

Science.gov (United States)

Keller, Colleen S; Gonzales, Adelita; Fleuriet, K Jill

2005-04-01

Recruitment of minority participants for clinical research studies has been the topic of several analytical works. Yet retention of participants, most notably minority and underserved populations, is less reported and understood, even though these populations have elevated health risks. This article describes two related, intervention-based formative research projects in which researchers used treatment theory to address issues of recruitment and retention of minority women participants in an exercise program to reduce obesity. Treatment theory incorporates a model of health promotion that allows investigators to identify and control sources of extraneous variables. The authors' research demonstrates that treatment theory can improve retention of minority women participants by considering critical inputs, mediating processes, and substantive participant characteristics in intervention design.