21 CFR 862.2150 - Continuous flow sequential multiple chemistry analyzer for clinical use.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Continuous flow sequential multiple chemistry..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2150 Continuous flow sequential multiple chemistry...

Modeling the energy content of combustible ship-scrapping waste at Alang-Sosiya, India, using multiple regression analysis.

PubMed

Reddy, M Srinivasa; Basha, Shaik; Joshi, H V; Sravan Kumar, V G; Jha, B; Ghosh, P K

2005-01-01

Alang-Sosiya is the largest ship-scrapping yard in the world, established in 1982. Every year an average of 171 ships having a mean weight of 2.10 x 10(6)(+/-7.82 x 10(5)) of light dead weight tonnage (LDT) being scrapped. Apart from scrapped metals, this yard generates a massive amount of combustible solid waste in the form of waste wood, plastic, insulation material, paper, glass wool, thermocol pieces (polyurethane foam material), sponge, oiled rope, cotton waste, rubber, etc. In this study multiple regression analysis was used to develop predictive models for energy content of combustible ship-scrapping solid wastes. The scope of work comprised qualitative and quantitative estimation of solid waste samples and performing a sequential selection procedure for isolating variables. Three regression models were developed to correlate the energy content (net calorific values (LHV)) with variables derived from material composition, proximate and ultimate analyses. The performance of these models for this particular waste complies well with the equations developed by other researchers (Dulong, Steuer, Scheurer-Kestner and Bento's) for estimating energy content of municipal solid waste.

Effects of a web-based tailored multiple-lifestyle intervention for adults: a two-year randomized controlled trial comparing sequential and simultaneous delivery modes.

PubMed

Schulz, Daniela N; Kremers, Stef P J; Vandelanotte, Corneel; van Adrichem, Mathieu J G; Schneider, Francine; Candel, Math J J M; de Vries, Hein

2014-01-27

Web-based computer-tailored interventions for multiple health behaviors can have a significant public health impact. Yet, few randomized controlled trials have tested this assumption. The objective of this paper was to test the effects of a sequential and simultaneous Web-based tailored intervention on multiple lifestyle behaviors. A randomized controlled trial was conducted with 3 tailoring conditions (ie, sequential, simultaneous, and control conditions) in the Netherlands in 2009-2012. Follow-up measurements took place after 12 and 24 months. The intervention content was based on the I-Change model. In a health risk appraisal, all respondents (N=5055) received feedback on their lifestyle behaviors that indicated whether they complied with the Dutch guidelines for physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking. Participants in the sequential (n=1736) and simultaneous (n=1638) conditions received tailored motivational feedback to change unhealthy behaviors one at a time (sequential) or all at the same time (simultaneous). Mixed model analyses were performed as primary analyses; regression analyses were done as sensitivity analyses. An overall risk score was used as outcome measure, then effects on the 5 individual lifestyle behaviors were assessed and a process evaluation was performed regarding exposure to and appreciation of the intervention. Both tailoring strategies were associated with small self-reported behavioral changes. The sequential condition had the most significant effects compared to the control condition after 12 months (T1, effect size=0.28). After 24 months (T2), the simultaneous condition was most effective (effect size=0.18). All 5 individual lifestyle behaviors changed over time, but few effects differed significantly between the conditions. At both follow-ups, the sequential condition had significant changes in smoking abstinence compared to the simultaneous condition (T1 effect size=0.31; T2 effect size=0.41). The sequential condition was more effective in decreasing alcohol consumption than the control condition at 24 months (effect size=0.27). Change was predicted by the amount of exposure to the intervention (total visiting time: beta=-.06; P=.01; total number of visits: beta=-.11; P<.001). Both interventions were appreciated well by respondents without significant differences between conditions. Although evidence was found for the effectiveness of both programs, no simple conclusive finding could be drawn about which intervention mode was more effective. The best kind of intervention may depend on the behavior that is targeted or on personal preferences and motivation. Further research is needed to identify moderators of intervention effectiveness. The results need to be interpreted in view of the high and selective dropout rates, multiple comparisons, and modest effect sizes. However, a large number of people were reached at low cost and behavioral change was achieved after 2 years. Nederlands Trial Register: NTR 2168; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2168 (Archived by WebCite at http://www.webcitation.org/6MbUqttYB).

Maternal risk factors predicting child physical characteristics and dysmorphology in fetal alcohol syndrome and partial fetal alcohol syndrome.

PubMed

May, Philip A; Tabachnick, Barbara G; Gossage, J Phillip; Kalberg, Wendy O; Marais, Anna-Susan; Robinson, Luther K; Manning, Melanie; Buckley, David; Hoyme, H Eugene

2011-12-01

Previous research in South Africa revealed very high rates of fetal alcohol syndrome (FAS), of 46-89 per 1000 among young children. Maternal and child data from studies in this community summarize the multiple predictors of FAS and partial fetal alcohol syndrome (PFAS). Sequential regression was employed to examine influences on child physical characteristics and dysmorphology from four categories of maternal traits: physical, demographic, childbearing, and drinking. Then, a structural equation model (SEM) was constructed to predict influences on child physical characteristics. Individual sequential regressions revealed that maternal drinking measures were the most powerful predictors of a child's physical anomalies (R² = .30, p < .001), followed by maternal demographics (R² = .24, p < .001), maternal physical characteristics (R²=.15, p < .001), and childbearing variables (R² = .06, p < .001). The SEM utilized both individual variables and the four composite categories of maternal traits to predict a set of child physical characteristics, including a total dysmorphology score. As predicted, drinking behavior is a relatively strong predictor of child physical characteristics (β = 0.61, p < .001), even when all other maternal risk variables are included; higher levels of drinking predict child physical anomalies. Overall, the SEM model explains 62% of the variance in child physical anomalies. As expected, drinking variables explain the most variance. But this highly controlled estimation of multiple effects also reveals a significant contribution played by maternal demographics and, to a lesser degree, maternal physical and childbearing variables. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Crop status evaluations and yield predictions

NASA Technical Reports Server (NTRS)

Haun, J. R.

1975-01-01

A model was developed for predicting the day 50 percent of the wheat crop is planted in North Dakota. This model incorporates location as an independent variable. The Julian date when 50 percent of the crop was planted for the nine divisions of North Dakota for seven years was regressed on the 49 variables through the step-down multiple regression procedure. This procedure begins with all of the independent variables and sequentially removes variables that are below a predetermined level of significance after each step. The prediction equation was tested on daily data. The accuracy of the model is considered satisfactory for finding the historic dates on which to initiate yield prediction model. Growth prediction models were also developed for spring wheat.

Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO₃ single extractions in a pot experiment with V-Cd treatments.

PubMed

Yang, Jie; Teng, Yanguo; Zuo, Rui; Song, Liuting

2015-06-01

The BCR sequential extraction procedure was compared with EDTA, HCl, and NaNO3 single extractions for evaluating vanadium bioavailability in alfalfa rhizosphere soil. The amounts of vanadium extracted by these methods were in the following order: BCR (bioavailable V) > EDTA ≈ HCl > NaNO3. Both correlation analysis and stepwise regression were adopted to illustrate the extractable vanadium between different reagents. The correlation coefficients between extracted vanadium and the vanadium contents in alfalfa roots were R NaNO3 = 0.948, R HCl = 0.902, R EDTA = 0.816, and R bioavailable V = 0.819. The stepwise multiple regression equation of the NaNO3 extraction was the most significant at a 95 % confidence interval. The influence of pH, total organic carbon, and cadmium content of soil to vanadium bioavailability were not definite. In summary, both the BCR sequential extraction and the single extraction methods were valid approaches for predicting vanadium bioavailability in alfalfa rhizosphere soil, especially the single extractions.

Effects of a Web-Based Tailored Multiple-Lifestyle Intervention for Adults: A Two-Year Randomized Controlled Trial Comparing Sequential and Simultaneous Delivery Modes

PubMed Central

Kremers, Stef PJ; Vandelanotte, Corneel; van Adrichem, Mathieu JG; Schneider, Francine; Candel, Math JJM; de Vries, Hein

2014-01-01

Background Web-based computer-tailored interventions for multiple health behaviors can have a significant public health impact. Yet, few randomized controlled trials have tested this assumption. Objective The objective of this paper was to test the effects of a sequential and simultaneous Web-based tailored intervention on multiple lifestyle behaviors. Methods A randomized controlled trial was conducted with 3 tailoring conditions (ie, sequential, simultaneous, and control conditions) in the Netherlands in 2009-2012. Follow-up measurements took place after 12 and 24 months. The intervention content was based on the I-Change model. In a health risk appraisal, all respondents (N=5055) received feedback on their lifestyle behaviors that indicated whether they complied with the Dutch guidelines for physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking. Participants in the sequential (n=1736) and simultaneous (n=1638) conditions received tailored motivational feedback to change unhealthy behaviors one at a time (sequential) or all at the same time (simultaneous). Mixed model analyses were performed as primary analyses; regression analyses were done as sensitivity analyses. An overall risk score was used as outcome measure, then effects on the 5 individual lifestyle behaviors were assessed and a process evaluation was performed regarding exposure to and appreciation of the intervention. Results Both tailoring strategies were associated with small self-reported behavioral changes. The sequential condition had the most significant effects compared to the control condition after 12 months (T1, effect size=0.28). After 24 months (T2), the simultaneous condition was most effective (effect size=0.18). All 5 individual lifestyle behaviors changed over time, but few effects differed significantly between the conditions. At both follow-ups, the sequential condition had significant changes in smoking abstinence compared to the simultaneous condition (T1 effect size=0.31; T2 effect size=0.41). The sequential condition was more effective in decreasing alcohol consumption than the control condition at 24 months (effect size=0.27). Change was predicted by the amount of exposure to the intervention (total visiting time: beta=–.06; P=.01; total number of visits: beta=–.11; P<.001). Both interventions were appreciated well by respondents without significant differences between conditions. Conclusions Although evidence was found for the effectiveness of both programs, no simple conclusive finding could be drawn about which intervention mode was more effective. The best kind of intervention may depend on the behavior that is targeted or on personal preferences and motivation. Further research is needed to identify moderators of intervention effectiveness. The results need to be interpreted in view of the high and selective dropout rates, multiple comparisons, and modest effect sizes. However, a large number of people were reached at low cost and behavioral change was achieved after 2 years. Trial Registration Nederlands Trial Register: NTR 2168; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2168 (Archived by WebCite at http://www.webcitation.org/6MbUqttYB). PMID:24472854

Sequential Processing and the Matching-Stimulus Interval Effect in ERP Components: An Exploration of the Mechanism Using Multiple Regression

PubMed Central

Steiner, Genevieve Z.; Barry, Robert J.; Gonsalvez, Craig J.

2016-01-01

In oddball tasks, increasing the time between stimuli within a particular condition (target-to-target interval, TTI; nontarget-to-nontarget interval, NNI) systematically enhances N1, P2, and P300 event-related potential (ERP) component amplitudes. This study examined the mechanism underpinning these effects in ERP components recorded from 28 adults who completed a conventional three-tone oddball task. Bivariate correlations, partial correlations and multiple regression explored component changes due to preceding ERP component amplitudes and intervals found within the stimulus series, rather than constraining the task with experimentally constructed intervals, which has been adequately explored in prior studies. Multiple regression showed that for targets, N1 and TTI predicted N2, TTI predicted P3a and P3b, and Processing Negativity (PN), P3b, and TTI predicted reaction time. For rare nontargets, P1 predicted N1, NNI predicted N2, and N1 predicted Slow Wave (SW). Findings show that the mechanism is operating on separate stages of stimulus-processing, suggestive of either increased activation within a number of stimulus-specific pathways, or very long component generator recovery cycles. These results demonstrate the extent to which matching-stimulus intervals influence ERP component amplitudes and behavior in a three-tone oddball task, and should be taken into account when designing similar studies. PMID:27445774

Sequential Processing and the Matching-Stimulus Interval Effect in ERP Components: An Exploration of the Mechanism Using Multiple Regression.

PubMed

Steiner, Genevieve Z; Barry, Robert J; Gonsalvez, Craig J

2016-01-01

In oddball tasks, increasing the time between stimuli within a particular condition (target-to-target interval, TTI; nontarget-to-nontarget interval, NNI) systematically enhances N1, P2, and P300 event-related potential (ERP) component amplitudes. This study examined the mechanism underpinning these effects in ERP components recorded from 28 adults who completed a conventional three-tone oddball task. Bivariate correlations, partial correlations and multiple regression explored component changes due to preceding ERP component amplitudes and intervals found within the stimulus series, rather than constraining the task with experimentally constructed intervals, which has been adequately explored in prior studies. Multiple regression showed that for targets, N1 and TTI predicted N2, TTI predicted P3a and P3b, and Processing Negativity (PN), P3b, and TTI predicted reaction time. For rare nontargets, P1 predicted N1, NNI predicted N2, and N1 predicted Slow Wave (SW). Findings show that the mechanism is operating on separate stages of stimulus-processing, suggestive of either increased activation within a number of stimulus-specific pathways, or very long component generator recovery cycles. These results demonstrate the extent to which matching-stimulus intervals influence ERP component amplitudes and behavior in a three-tone oddball task, and should be taken into account when designing similar studies.

Heterogeneous Suppression of Sequential Effects in Random Sequence Generation, but Not in Operant Learning.

PubMed

Shteingart, Hanan; Loewenstein, Yonatan

2016-01-01

There is a long history of experiments in which participants are instructed to generate a long sequence of binary random numbers. The scope of this line of research has shifted over the years from identifying the basic psychological principles and/or the heuristics that lead to deviations from randomness, to one of predicting future choices. In this paper, we used generalized linear regression and the framework of Reinforcement Learning in order to address both points. In particular, we used logistic regression analysis in order to characterize the temporal sequence of participants' choices. Surprisingly, a population analysis indicated that the contribution of the most recent trial has only a weak effect on behavior, compared to more preceding trials, a result that seems irreconcilable with standard sequential effects that decay monotonously with the delay. However, when considering each participant separately, we found that the magnitudes of the sequential effect are a monotonous decreasing function of the delay, yet these individual sequential effects are largely averaged out in a population analysis because of heterogeneity. The substantial behavioral heterogeneity in this task is further demonstrated quantitatively by considering the predictive power of the model. We show that a heterogeneous model of sequential dependencies captures the structure available in random sequence generation. Finally, we show that the results of the logistic regression analysis can be interpreted in the framework of reinforcement learning, allowing us to compare the sequential effects in the random sequence generation task to those in an operant learning task. We show that in contrast to the random sequence generation task, sequential effects in operant learning are far more homogenous across the population. These results suggest that in the random sequence generation task, different participants adopt different cognitive strategies to suppress sequential dependencies when generating the "random" sequences.

Sequential-Simultaneous Analysis of Japanese Children's Performance on the Japanese McCarthy.

ERIC Educational Resources Information Center

Ishikuma, Toshinori; And Others

This study explored the hypothesis that Japanese children perform significantly better on simultaneous processing than on sequential processing. The Kaufman Assessment Battery for Children (K-ABC) served as the criterion of the two types of mental processing. Regression equations to predict Sequential and Simultaneous processing from McCarthy…

Simultaneity, Sequentiality, and Speed: Organizational Messages about Multiple-Task Completion

ERIC Educational Resources Information Center

Stephens, Keri K.; Cho, Jaehee K.; Ballard, Dawna I.

2012-01-01

Workplace norms for task completion increasingly value speed and the ability to accomplish multiple tasks at once. This study situates this popularized issue of multitasking within the context of chronemics scholarship by addressing related issues of simultaneity, sequentiality, and speed. Ultimately, we consider 2 multiple-task completion…

Auditory processing and phonological awareness skills of five-year-old children with and without musical experience.

PubMed

Escalda, Júlia; Lemos, Stela Maris Aguiar; França, Cecília Cavalieri

2011-09-01

To investigate the relations between musical experience, auditory processing and phonological awareness of groups of 5-year-old children with and without musical experience. Participants were 56 5-year-old subjects of both genders, 26 in the Study Group, consisting of children with musical experience, and 30 in the Control Group, consisting of children without musical experience. All participants were assessed with the Simplified Auditory Processing Assessment and Phonological Awareness Test and the data was statistically analyzed. There was a statistically significant difference between the results of the sequential memory test for verbal and non-verbal sounds with four stimuli, phonological awareness tasks of rhyme recognition, phonemic synthesis and phonemic deletion. Analysis of multiple binary logistic regression showed that, with exception of the sequential verbal memory with four syllables, the observed difference in subjects' performance was associated with their musical experience. Musical experience improves auditory and metalinguistic abilities of 5-year-old children.

Comparative efficacy of simultaneous versus sequential multiple health behavior change interventions among adults: A systematic review of randomised trials.

PubMed

James, Erica; Freund, Megan; Booth, Angela; Duncan, Mitch J; Johnson, Natalie; Short, Camille E; Wolfenden, Luke; Stacey, Fiona G; Kay-Lambkin, Frances; Vandelanotte, Corneel

2016-08-01

Growing evidence points to the benefits of addressing multiple health behaviors rather than single behaviors. This review evaluates the relative effectiveness of simultaneous and sequentially delivered multiple health behavior change (MHBC) interventions. Secondary aims were to identify: a) the most effective spacing of sequentially delivered components; b) differences in efficacy of MHBC interventions for adoption/cessation behaviors and lifestyle/addictive behaviors, and; c) differences in trial retention between simultaneously and sequentially delivered interventions. MHBC intervention trials published up to October 2015 were identified through a systematic search. Eligible trials were randomised controlled trials that directly compared simultaneous and sequential delivery of a MHBC intervention. A narrative synthesis was undertaken. Six trials met the inclusion criteria and across these trials the behaviors targeted were smoking, diet, physical activity, and alcohol consumption. Three trials reported a difference in intervention effect between a sequential and simultaneous approach in at least one behavioral outcome. Of these, two trials favoured a sequential approach on smoking. One trial favoured a simultaneous approach on fat intake. There was no difference in retention between sequential and simultaneous approaches. There is limited evidence regarding the relative effectiveness of sequential and simultaneous approaches. Given only three of the six trials observed a difference in intervention effectiveness for one health behavior outcome, and the relatively consistent finding that the sequential and simultaneous approaches were more effective than a usual/minimal care control condition, it appears that both approaches should be considered equally efficacious. PROSPERO registration number: CRD42015027876. Copyright © 2016 Elsevier Inc. All rights reserved.

Acculturation Stress and Drinking Problems Among Urban Heavy Drinking Latinos in the Northeast

PubMed Central

Lee, Christina S.; Colby, Suzanne M.; Rohsenow, Damaris J.; López, Steven R.; Hernández, Lynn; Caetano, Raul

2014-01-01

This study investigates the relationship between level of acculturation and acculturation stress, and the extent to which each predicts problems related to drinking. Hispanics who met criteria for hazardous drinking completed measures of acculturation, acculturation stress, and drinking problems. Sequential multiple regression was used to determine whether levels of self-reported acculturation stress predicted concurrent alcohol problems after controlling for the predictive value of acculturation level. Acculturation stress accounted for significant variance in drinking problems while adjusting for acculturation, income, and education. Choosing to drink in response to acculturation stress should be an intervention target with Hispanic heavy drinkers. PMID:24215224

Acculturation stress and drinking problems among urban heavy drinking Latinos in the Northeast.

PubMed

Lee, Christina S; Colby, Suzanne M; Rohsenow, Damaris J; López, Steven R; Hernández, Lynn; Caetano, Raul

2013-01-01

This study investigates the relationship between the level of acculturation and acculturation stress and the extent to which each predicts problems related to drinking. Hispanics who met criteria for hazardous drinking completed measures of acculturation, acculturation stress, and drinking problems. Sequential multiple regression was used to determine whether the levels of self-reported acculturation stress predicted concurrent alcohol problems after controlling for the predictive value of the acculturation level. Acculturation stress accounted for a significant variance in drinking problems, while adjusting for acculturation, income, and education. Choosing to drink in response to acculturation stress should be an intervention target with Hispanic heavy drinkers.

Efficacy of premixed versus sequential administration of clonidine as an adjuvant to hyperbaric bupivacaine intrathecally in cesarean section

PubMed Central

Sachan, Prachee; Kumar, Nidhi; Sharma, Jagdish Prasad

2014-01-01

Background: Density of the drugs injected intrathecally is an important factor that influences spread in the cerebrospinal fluid. Mixing adjuvants with local anesthetics (LA) alters their density and hence their spread compared to when given sequentially in seperate syringes. Aims: To evaluate the efficacy of intrathecal administration of hyperbaric bupivacaine (HB) and clonidine as a mixture and sequentially in terms of block characteristics, hemodynamics, neonatal outcome, and postoperative pain. Setting and Design: Prospective randomized single blind study at a tertiary center from 2010 to 2012. Materials and Methods: Ninety full-term parturient scheduled for elective cesarean sections were divided into three groups on the basis of technique of intrathecal drug administration. Group M received mixture of 75 μg clonidine and 10 mg HB 0.5%. Group A received 75 μg clonidine after administration of 10 mg HB 0.5% through separate syringe. Group B received 75 μg clonidine before HB 0.5% (10 mg) through separate syringe. Statistical analysis used: Observational descriptive statistics, analysis of variance with Bonferroni multiple comparison post hoc test, and Chi-square test. Results: Time to achieve complete sensory and motor block was less in group A and B in which drugs were given sequentially. Duration of analgesia lasted longer in group B (474.3 ± 20.79 min) and group A (472.50 ± 22.11 min) than in group M (337 ± 18.22 min) with clinically insignificant influence on hemodynamic parameters and sedation. Conclusion: Sequential technique reduces time to achieve complete sensory and motor block, delays block regression, and significantly prolongs the duration of analgesia. However, it did not matter much whether clonidine was administered before or after HB. PMID:25886098

A Sequential Multiplicative Extended Kalman Filter for Attitude Estimation Using Vector Observations.

PubMed

Qin, Fangjun; Chang, Lubin; Jiang, Sai; Zha, Feng

2018-05-03

In this paper, a sequential multiplicative extended Kalman filter (SMEKF) is proposed for attitude estimation using vector observations. In the proposed SMEKF, each of the vector observations is processed sequentially to update the attitude, which can make the measurement model linearization more accurate for the next vector observation. This is the main difference to Murrell’s variation of the MEKF, which does not update the attitude estimate during the sequential procedure. Meanwhile, the covariance is updated after all the vector observations have been processed, which is used to account for the special characteristics of the reset operation necessary for the attitude update. This is the main difference to the traditional sequential EKF, which updates the state covariance at each step of the sequential procedure. The numerical simulation study demonstrates that the proposed SMEKF has more consistent and accurate performance in a wide range of initial estimate errors compared to the MEKF and its traditional sequential forms.

A Sequential Multiplicative Extended Kalman Filter for Attitude Estimation Using Vector Observations

PubMed Central

Qin, Fangjun; Jiang, Sai; Zha, Feng

2018-01-01

In this paper, a sequential multiplicative extended Kalman filter (SMEKF) is proposed for attitude estimation using vector observations. In the proposed SMEKF, each of the vector observations is processed sequentially to update the attitude, which can make the measurement model linearization more accurate for the next vector observation. This is the main difference to Murrell’s variation of the MEKF, which does not update the attitude estimate during the sequential procedure. Meanwhile, the covariance is updated after all the vector observations have been processed, which is used to account for the special characteristics of the reset operation necessary for the attitude update. This is the main difference to the traditional sequential EKF, which updates the state covariance at each step of the sequential procedure. The numerical simulation study demonstrates that the proposed SMEKF has more consistent and accurate performance in a wide range of initial estimate errors compared to the MEKF and its traditional sequential forms. PMID:29751538

Sequential infiltration synthesis for enhancing multiple-patterning lithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darling, Seth B.; Elam, Jeffrey W.; Tseng, Yu-Chih

Simplified methods of multiple-patterning photolithography using sequential infiltration synthesis to modify the photoresist such that it withstands plasma etching better than unmodified resist and replaces one or more hard masks and/or a freezing step in MPL processes including litho-etch-litho-etch photolithography or litho-freeze-litho-etch photolithography.

Using an innovative multiple regression procedure in a cancer population (Part 1): detecting and probing relationships of common interacting symptoms (pain, fatigue/weakness, sleep problems) as a strategy to discover influential symptom pairs and clusters

PubMed Central

Francoeur, Richard B

2015-01-01

Background The majority of patients with advanced cancer experience symptom pairs or clusters among pain, fatigue, and insomnia. Improved methods are needed to detect and interpret interactions among symptoms or diesease markers to reveal influential pairs or clusters. In prior work, I developed and validated sequential residual centering (SRC), a method that improves the sensitivity of multiple regression to detect interactions among predictors, by conditioning for multicollinearity (shared variation) among interactions and component predictors. Materials and methods Using a hypothetical three-way interaction among pain, fatigue, and sleep to predict depressive affect, I derive and explain SRC multiple regression. Subsequently, I estimate raw and SRC multiple regressions using real data for these symptoms from 268 palliative radiation outpatients. Results Unlike raw regression, SRC reveals that the three-way interaction (pain × fatigue/weakness × sleep problems) is statistically significant. In follow-up analyses, the relationship between pain and depressive affect is aggravated (magnified) within two partial ranges: 1) complete-to-some control over fatigue/weakness when there is complete control over sleep problems (ie, a subset of the pain–fatigue/weakness symptom pair), and 2) no control over fatigue/weakness when there is some-to-no control over sleep problems (ie, a subset of the pain–fatigue/weakness–sleep problems symptom cluster). Otherwise, the relationship weakens (buffering) as control over fatigue/weakness or sleep problems diminishes. Conclusion By reducing the standard error, SRC unmasks a three-way interaction comprising a symptom pair and cluster. Low-to-moderate levels of the moderator variable for fatigue/weakness magnify the relationship between pain and depressive affect. However, when the comoderator variable for sleep problems accompanies fatigue/weakness, only frequent or unrelenting levels of both symptoms magnify the relationship. These findings suggest that a countervailing mechanism involving depressive affect could account for the effectiveness of a cognitive behavioral intervention to reduce the severity of a pain, fatigue, and sleep disturbance cluster in a previous randomized trial. PMID:25565865

Using an innovative multiple regression procedure in a cancer population (Part 1): detecting and probing relationships of common interacting symptoms (pain, fatigue/weakness, sleep problems) as a strategy to discover influential symptom pairs and clusters.

PubMed

Francoeur, Richard B

2015-01-01

The majority of patients with advanced cancer experience symptom pairs or clusters among pain, fatigue, and insomnia. Improved methods are needed to detect and interpret interactions among symptoms or diesease markers to reveal influential pairs or clusters. In prior work, I developed and validated sequential residual centering (SRC), a method that improves the sensitivity of multiple regression to detect interactions among predictors, by conditioning for multicollinearity (shared variation) among interactions and component predictors. Using a hypothetical three-way interaction among pain, fatigue, and sleep to predict depressive affect, I derive and explain SRC multiple regression. Subsequently, I estimate raw and SRC multiple regressions using real data for these symptoms from 268 palliative radiation outpatients. Unlike raw regression, SRC reveals that the three-way interaction (pain × fatigue/weakness × sleep problems) is statistically significant. In follow-up analyses, the relationship between pain and depressive affect is aggravated (magnified) within two partial ranges: 1) complete-to-some control over fatigue/weakness when there is complete control over sleep problems (ie, a subset of the pain-fatigue/weakness symptom pair), and 2) no control over fatigue/weakness when there is some-to-no control over sleep problems (ie, a subset of the pain-fatigue/weakness-sleep problems symptom cluster). Otherwise, the relationship weakens (buffering) as control over fatigue/weakness or sleep problems diminishes. By reducing the standard error, SRC unmasks a three-way interaction comprising a symptom pair and cluster. Low-to-moderate levels of the moderator variable for fatigue/weakness magnify the relationship between pain and depressive affect. However, when the comoderator variable for sleep problems accompanies fatigue/weakness, only frequent or unrelenting levels of both symptoms magnify the relationship. These findings suggest that a countervailing mechanism involving depressive affect could account for the effectiveness of a cognitive behavioral intervention to reduce the severity of a pain, fatigue, and sleep disturbance cluster in a previous randomized trial.

Comment on "Cosmic-ray-driven reaction and greenhouse effect of halogenated molecules: Culprits for atmospheric ozone depletion and global climate change"

NASA Astrophysics Data System (ADS)

Nuccitelli, Dana; Cowtan, Kevin; Jacobs, Peter; Richardson, Mark; Way, Robert G.; Blackburn, Anne-Marie; Stolpe, Martin B.; Cook, John

2014-04-01

Lu (2013) (L13) argued that solar effects and anthropogenic halogenated gases can explain most of the observed warming of global mean surface air temperatures since 1850, with virtually no contribution from atmospheric carbon dioxide (CO2) concentrations. Here we show that this conclusion is based on assumptions about the saturation of the CO2-induced greenhouse effect that have been experimentally falsified. L13 also confuses equilibrium and transient response, and relies on data sources that have been superseeded due to known inaccuracies. Furthermore, the statistical approach of sequential linear regression artificially shifts variance onto the first predictor. L13's artificial choice of regression order and neglect of other relevant data is the fundamental cause of the incorrect main conclusion. Consideration of more modern data and a more parsimonious multiple regression model leads to contradiction with L13's statistical results. Finally, the correlation arguments in L13 are falsified by considering either the more appropriate metric of global heat accumulation, or data on longer timescales.

Terminating Sequential Delphi Survey Data Collection

ERIC Educational Resources Information Center

Kalaian, Sema A.; Kasim, Rafa M.

2012-01-01

The Delphi survey technique is an iterative mail or electronic (e-mail or web-based) survey method used to obtain agreement or consensus among a group of experts in a specific field on a particular issue through a well-designed and systematic multiple sequential rounds of survey administrations. Each of the multiple rounds of the Delphi survey…

Analyses of group sequential clinical trials.

PubMed

Koepcke, W

1989-12-01

In the first part of this article the methodology of group sequential plans is reviewed. After introducing the basic definition of such plans the main properties are shown. At the end of this section three different plans (Pocock, O'Brien-Fleming, Koepcke) are compared. In the second part of the article some unresolved issues and recent developments in the application of group sequential methods to long-term controlled clinical trials are discussed. These include deviation from the assumptions, life table methods, multiple-arm clinical trials, multiple outcome measures, and confidence intervals.

Context-Dependent Upper Limb Prosthesis Control for Natural and Robust Use.

PubMed

Amsuess, Sebastian; Vujaklija, Ivan; Goebel, Peter; Roche, Aidan D; Graimann, Bernhard; Aszmann, Oskar C; Farina, Dario

2016-07-01

Pattern recognition and regression methods applied to the surface EMG have been used for estimating the user intended motor tasks across multiple degrees of freedom (DOF), for prosthetic control. While these methods are effective in several conditions, they are still characterized by some shortcomings. In this study we propose a methodology that combines these two approaches for mutually alleviating their limitations. This resulted in a control method capable of context-dependent movement estimation that switched automatically between sequential (one DOF at a time) or simultaneous (multiple DOF) prosthesis control, based on an online estimation of signal dimensionality. The proposed method was evaluated in scenarios close to real-life situations, with the control of a physical prosthesis in applied tasks of varying difficulties. Test prostheses were individually manufactured for both able-bodied and transradial amputee subjects. With these prostheses, two amputees performed the Southampton Hand Assessment Procedure test with scores of 58 and 71 points. The five able-bodied individuals performed standardized tests, such as the box&block and clothes pin test, reducing the completion times by up to 30%, with respect to using a state-of-the-art pure sequential control algorithm. Apart from facilitating fast simultaneous movements, the proposed control scheme was also more intuitive to use, since human movements are predominated by simultaneous activations across joints. The proposed method thus represents a significant step towards intelligent, intuitive and natural control of upper limb prostheses.

A SEQUENTIAL, MULTIPLE-TREATMENT, TARGETED APPROACH TO REDUCE WOUND HEALING AND FAILURE OF GLAUCOMA FILTRATION SURGERY IN A RABBIT MODEL (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

PubMed Central

Sherwood, Mark Brian

2006-01-01

Purpose The purpose of this study was to evaluate the concept of targeting mediators of the scarring process at multiple points across the course of bleb failure, in order to prolong bleb survival. Methods There were three linked parts to the experiment. In the first part, a cannula glaucoma filtration surgery (GFS) was performed on 32 New Zealand White (NZW) rabbits, and bleb survival was assessed for six different regimens plus controls by grading bleb height and width. For the second part of the study, the same GFS surgery was performed on an additional 10 NZW rabbits. Two additional filtering blebs were treated with balanced saline solution (BSS), two received mitomycin-C (MMC) (0.4 mg/mL), and for the remaining six, a sequential regimen was given consisting of 200 mmol/L mannose-6-phosphate (M-6-P) solution at the time of surgery, followed by subconjunctival injections of antibody to connective tissue growth factor at days 2 and 4, and Ilomastat, a broad-spectrum matrix metalloproteinase inhibitor, at days 7, 12, and 20 postoperatively. Bleb survival was again assessed. In the final part of the experiment, blebs treated with either BSS, MMC, or the above sequential multitreatment regimen were examined histologically at 14 days postoperatively in three additional NZW rabbits. Results All six individual therapies selected resulted in some improvement of bleb survival compared to BSS control. Blebs treated with the new sequential, multitreatment protocol survived an average of 29 days (regression slope, P < .0001 compared to control), those receiving BSS an average of 17 days, and those treated with MMC (0.4 mg/mL) an average of 36 days. The sequential, multitreatment regimen was significantly superior to any of the six monotherapies for time to zero analysis (flattening) of the bleb (P < .002). Histologic examination of the bleb tissues showed a markedly less epithelial thinning, subepithelial collagen thinning, and goblet cell loss in the multitreatment group, when compared with the MMC blebs. Conclusions In a rabbit model of GFS, a sequential, targeted, multitreatment approach prolonged bleb survival compared to BSS controls and decreased bleb tissue morphological changes when compared to those treated with MMC. It is not known whether these findings can be reproduced in humans, and further work is needed to determine an optimum regimen and timing of therapeutic delivery. PMID:17471357

Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay

PubMed Central

Mahoney, J. Matthew; Titiz, Ali S.; Hernan, Amanda E.; Scott, Rod C.

2016-01-01

Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation. PMID:26866597

Importance of vital signs to the early diagnosis and severity of sepsis: association between vital signs and sequential organ failure assessment score in patients with sepsis.

PubMed

Kenzaka, Tsuneaki; Okayama, Masanobu; Kuroki, Shigehiro; Fukui, Miho; Yahata, Shinsuke; Hayashi, Hiroki; Kitao, Akihito; Sugiyama, Daisuke; Kajii, Eiji; Hashimoto, Masayoshi

2012-01-01

While much attention is given to the fifth vital sign, the utility of the 4 classic vital signs (blood pressure, respiratory rate, body temperature, and heart rate) has been neglected. The aim of this study was to assess a possible association between vital signs and the Sequential Organ Failure Assessment (SOFA) score in patients with sepsis. We performed a prospective, observational study of 206 patients with sepsis. Blood pressure, respiratory rate, body temperature, and heart rate were measured on arrival at the hospital. The SOFA score was also determined on the day of admission. Bivariate correlation analysis showed that all of the vital signs were correlated with the SOFA score. Multiple regression analysis indicated that decreased values of systolic blood pressure (multivariate regression coefficient [Coef] = -0.030, 95% confidence interval [CI] = -0.046 to -0.013) and diastolic blood pressure (Coef = -0.045, 95% CI = -0.070 to -0.019), increased respiratory rate (Coef = 0.176, 95% CI = 0.112 to 0.240), and increased shock index (Coef = 4.232, 95% CI = 2.401 to 6.062) significantly influenced the SOFA score. Increased respiratory rate and shock index were significantly correlated with disease severity in patients with sepsis. Evaluation of these signs may therefore improve early identification of severely ill patients at triage, allowing more aggressive and timely interventions to improve the prognosis of these patients.

Bioerodible System for Sequential Release of Multiple Drugs

PubMed Central

Sundararaj, Sharath C.; Thomas, Mark V.; Dziubla, Thomas D.; Puleo, David A.

2013-01-01

Because many complex physiological processes are controlled by multiple biomolecules, comprehensive treatment of certain disease conditions may be more effectively achieved by administration of more than one type of drug. Thus, the objective of the present research was to develop a multilayered, polymer-based system for sequential delivery of multiple drugs. The polymers used were cellulose acetate phthalate (CAP) complexed with Pluronic F-127 (P). After evaluating morphology of the resulting CAPP system, in vitro release of small molecule drugs and a model protein was studied from both single and multilayered devices. Drug release from single-layered CAPP films followed zero-order kinetics related to surface erosion of the association polymer. Release studies from multilayered CAPP devices showed the possibility of achieving intermittent release of one type of drug as well as sequential release of more than one type of drug. Mathematical modeling accurately predicted the release profiles for both single layer and multilayered devices. The present CAPP association polymer-based multilayer devices can be used for localized, sequential delivery of multiple drugs for the possible treatment of complex disease conditions, and perhaps for tissue engineering applications, that require delivery of more than one type of biomolecule. PMID:24096151

Synthesis of Polyheteroaromatic Compounds via Rhodium-Catalyzed Multiple C-H Bond Activation and Oxidative Annulation.

PubMed

Peng, Shiyong; Liu, Suna; Zhang, Sai; Cao, Shengyu; Sun, Jiangtao

2015-10-16

Polyheteroaromatic compounds are potential optoelectronic conjugated materials due to their electro- and photochemical properties. Transition-metal-catalyzed multiple C-H activation and sequential oxidative annulation allows rapidly assembling of those compounds from readily available starting materials. A rhodium-catalyzed cascade oxidative annulation of β-enamino esters or 4-aminocoumarins with internal alkynes is described to access those compounds, featuring multiple C-H/N-H bond cleavages and sequential C-C/C-N bond formations in one pot.

Multiple Ordinal Regression by Maximizing the Sum of Margins

PubMed Central

Hamsici, Onur C.; Martinez, Aleix M.

2016-01-01

Human preferences are usually measured using ordinal variables. A system whose goal is to estimate the preferences of humans and their underlying decision mechanisms requires to learn the ordering of any given sample set. We consider the solution of this ordinal regression problem using a Support Vector Machine algorithm. Specifically, the goal is to learn a set of classifiers with common direction vectors and different biases correctly separating the ordered classes. Current algorithms are either required to solve a quadratic optimization problem, which is computationally expensive, or are based on maximizing the minimum margin (i.e., a fixed margin strategy) between a set of hyperplanes, which biases the solution to the closest margin. Another drawback of these strategies is that they are limited to order the classes using a single ranking variable (e.g., perceived length). In this paper, we define a multiple ordinal regression algorithm based on maximizing the sum of the margins between every consecutive class with respect to one or more rankings (e.g., perceived length and weight). We provide derivations of an efficient, easy-to-implement iterative solution using a Sequential Minimal Optimization procedure. We demonstrate the accuracy of our solutions in several datasets. In addition, we provide a key application of our algorithms in estimating human subjects’ ordinal classification of attribute associations to object categories. We show that these ordinal associations perform better than the binary one typically employed in the literature. PMID:26529784

Evaluation of aroma enhancement for "Ecolly" dry white wines by mixed inoculation of selected Rhodotorula mucilaginosa and Saccharomyces cerevisiae.

PubMed

Wang, Xing-Chen; Li, Ai-Hua; Dizy, Marta; Ullah, Niamat; Sun, Wei-Xuan; Tao, Yong-Sheng

2017-08-01

To improve the aroma profile of Ecolly dry white wine, the simultaneous and sequential inoculations of selected Rhodotorula mucilaginosa and Saccharomyces cerevisiae were performed in wine making of this work. The two yeasts were mixed in various ratios for making the mixed inoculum. The amount of volatiles and aroma characteristics were determined the following year. Mixed fermentation improved both the varietal and fermentative aroma compound composition, especially that of (Z)-3-hexene-1-ol, nerol oxide, certain acetates and ethyls group compounds. Citrus, sweet fruit, acid fruit, berry, and floral aroma traits were enhanced by mixed fermentation; however, an animal note was introduced upon using higher amounts of R. mucilaginosa. Aroma traits were regressed with volatiles as observed by the partial least-square regression method. Analysis of correlation coefficients revealed that the aroma traits were the multiple interactions of volatile compounds, with the fermentative volatiles having more impact on aroma than varietal compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential Prediction of Literacy Achievement for Specific Learning Disabilities Contrasting in Impaired Levels of Language in Grades 4 to 9

ERIC Educational Resources Information Center

Sanders, Elizabeth A.; Berninger, Virginia W.; Abbott, Robert D.

2018-01-01

Sequential regression was used to evaluate whether language-related working memory components uniquely predict reading and writing achievement beyond cognitive-linguistic translation for students in Grades 4 through 9 (N = 103) with specific learning disabilities (SLDs) in subword handwriting (dysgraphia, n = 25), word reading and spelling…

Sequential Superresolution Imaging of Multiple Targets Using a Single Fluorophore

PubMed Central

Lidke, Diane S.; Lidke, Keith A.

2015-01-01

Fluorescence superresolution (SR) microscopy, or fluorescence nanoscopy, provides nanometer scale detail of cellular structures and allows for imaging of biological processes at the molecular level. Specific SR imaging methods, such as localization-based imaging, rely on stochastic transitions between on (fluorescent) and off (dark) states of fluorophores. Imaging multiple cellular structures using multi-color imaging is complicated and limited by the differing properties of various organic dyes including their fluorescent state duty cycle, photons per switching event, number of fluorescent cycles before irreversible photobleaching, and overall sensitivity to buffer conditions. In addition, multiple color imaging requires consideration of multiple optical paths or chromatic aberration that can lead to differential aberrations that are important at the nanometer scale. Here, we report a method for sequential labeling and imaging that allows for SR imaging of multiple targets using a single fluorophore with negligible cross-talk between images. Using brightfield image correlation to register and overlay multiple image acquisitions with ~10 nm overlay precision in the x-y imaging plane, we have exploited the optimal properties of AlexaFluor647 for dSTORM to image four distinct cellular proteins. We also visualize the changes in co-localization of the epidermal growth factor (EGF) receptor and clathrin upon EGF addition that are consistent with clathrin-mediated endocytosis. These results are the first to demonstrate sequential SR (s-SR) imaging using direct stochastic reconstruction microscopy (dSTORM), and this method for sequential imaging can be applied to any superresolution technique. PMID:25860558

Multiuser signal detection using sequential decoding

NASA Astrophysics Data System (ADS)

Xie, Zhenhua; Rushforth, Craig K.; Short, Robert T.

1990-05-01

The application of sequential decoding to the detection of data transmitted over the additive white Gaussian noise channel by K asynchronous transmitters using direct-sequence spread-spectrum multiple access is considered. A modification of Fano's (1963) sequential-decoding metric, allowing the messages from a given user to be safely decoded if its Eb/N0 exceeds -1.6 dB, is presented. Computer simulation is used to evaluate the performance of a sequential decoder that uses this metric in conjunction with the stack algorithm. In many circumstances, the sequential decoder achieves results comparable to those obtained using the much more complicated optimal receiver.

Development of binomial sequential sampling plans for forecasting Listronotus maculicollis (Coleoptera: Curculionidae) larvae based on the relationship to adult counts and turfgrass damage.

PubMed

McGraw, Benjamin A; Koppenhöfer, Albrecht M

2009-06-01

Binomial sequential sampling plans were developed to forecast weevil Listronotus maculicollis Kirby (Coleoptera: Curculionidae), larval damage to golf course turfgrass and aid in the development of integrated pest management programs for the weevil. Populations of emerging overwintered adults were sampled over a 2-yr period to determine the relationship between adult counts, larval density, and turfgrass damage. Larval density and composition of preferred host plants (Poa annua L.) significantly affected the expression of turfgrass damage. Multiple regression indicates that damage may occur in moderately mixed P. annua stands with as few as 10 larvae per 0.09 m2. However, > 150 larvae were required before damage became apparent in pure Agrostis stolonifera L. plots. Adult counts during peaks in emergence as well as cumulative counts across the emergence period were significantly correlated to future densities of larvae. Eight binomial sequential sampling plans based on two tally thresholds for classifying infestation (T = 1 and two adults) and four adult density thresholds (0.5, 0.85, 1.15, and 1.35 per 3.34 m2) were developed to forecast the likelihood of turfgrass damage by using adult counts during peak emergence. Resampling for validation of sample plans software was used to validate sampling plans with field-collected data sets. All sampling plans were found to deliver accurate classifications (correct decisions were made between 84.4 and 96.8%) in a practical timeframe (average sampling cost < 22.7 min).

Visual short-term memory for sequential arrays.

PubMed

Kumar, Arjun; Jiang, Yuhong

2005-04-01

The capacity of visual short-term memory (VSTM) for a single visual display has been investigated in past research, but VSTM for multiple sequential arrays has been explored only recently. In this study, we investigate the capacity of VSTM across two sequential arrays separated by a variable stimulus onset asynchrony (SOA). VSTM for spatial locations (Experiment 1), colors (Experiments 2-4), orientations (Experiments 3 and 4), and conjunction of color and orientation (Experiment 4) were tested, with the SOA across the two sequential arrays varying from 100 to 1,500 msec. We find that VSTM for the trailing array is much better than VSTM for the leading array, but when averaged across the two arrays VSTM has a constant capacity independent of the SOA. We suggest that multiple displays compete for retention in VSTM and that separating information into two temporally discrete groups does not enhance the overall capacity of VSTM.

Who is most affected by prenatal alcohol exposure: Boys or girls?

PubMed

May, Philip A; Tabachnick, Barbara; Hasken, Julie M; Marais, Anna-Susan; de Vries, Marlene M; Barnard, Ronel; Joubert, Belinda; Cloete, Marise; Botha, Isobel; Kalberg, Wendy O; Buckley, David; Burroughs, Zachary R; Bezuidenhout, Heidre; Robinson, Luther K; Manning, Melanie A; Adnams, Colleen M; Seedat, Soraya; Parry, Charles D H; Hoyme, H Eugene

2017-08-01

To examine outcomes among boys and girls that are associated with prenatal alcohol exposure. Boys and girls with fetal alcohol spectrum disorders (FASD) and randomly-selected controls were compared on a variety of physical and neurobehavioral traits. Sex ratios indicated that heavy maternal binge drinking may have significantly diminished viability to birth and survival of boys postpartum more than girls by age seven. Case control comparisons of a variety of physical and neurobehavioral traits at age seven indicate that both sexes were affected similarly for a majority of variables. However, alcohol-exposed girls had significantly more dysmorphology overall than boys and performed significantly worse on non-verbal IQ tests than males. A three-step sequential regression analysis, controlling for multiple covariates, further indicated that dysmorphology among girls was significantly more associated with five maternal drinking variables and three distal maternal risk factors. However, the overall model, which included five associated neurobehavioral measures at step three, was not significant (p=0.09, two-tailed test). A separate sequential logistic regression analysis of predictors of a FASD diagnosis, however, indicated significantly more negative outcomes overall for girls than boys (Nagelkerke R 2 =0.42 for boys and 0.54 for girls, z=-2.9, p=0.004). Boys and girls had mostly similar outcomes when prenatal alcohol exposure was linked to poor physical and neurocognitive development. Nevertheless, sex ratios implicate lower viability and survival of males by first grade, and girls have more dysmorphology and neurocognitive impairment than boys resulting in a higher probability of a FASD diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Time Series ARIMA Models of Undergraduate Grade Point Average.

ERIC Educational Resources Information Center

Rogers, Bruce G.

The Auto-Regressive Integrated Moving Average (ARIMA) Models, often referred to as Box-Jenkins models, are regression methods for analyzing sequential dependent observations with large amounts of data. The Box-Jenkins approach, a three-stage procedure consisting of identification, estimation and diagnosis, was used to select the most appropriate…

Piezoelectric actuator uses sequentially-excited multiple elements: A concept

NASA Technical Reports Server (NTRS)

Sabelman, E. E.

1972-01-01

Utilizing arrays of sequentially-excited piezoelectric elements to provide motion in a nonmagnetic motor provide built-in redundancy and long life required for deployment or actuation of devices on spacecraft. Linear-motion motor devices can also be fabricated.

Multiple independent identification decisions: a method of calibrating eyewitness identifications.

PubMed

Pryke, Sean; Lindsay, R C L; Dysart, Jennifer E; Dupuis, Paul

2004-02-01

Two experiments (N = 147 and N = 90) explored the use of multiple independent lineups to identify a target seen live. In Experiment 1, simultaneous face, body, and sequential voice lineups were used. In Experiment 2, sequential face, body, voice, and clothing lineups were used. Both studies demonstrated that multiple identifications (by the same witness) from independent lineups of different features are highly diagnostic of suspect guilt (G. L. Wells & R. C. L. Lindsay, 1980). The number of suspect and foil selections from multiple independent lineups provides a powerful method of calibrating the accuracy of eyewitness identification. Implications for use of current methods are discussed. ((c) 2004 APA, all rights reserved)

A novel method for the sequential removal and separation of multiple heavy metals from wastewater.

PubMed

Fang, Li; Li, Liang; Qu, Zan; Xu, Haomiao; Xu, Jianfang; Yan, Naiqiang

2018-01-15

A novel method was developed and applied for the treatment of simulated wastewater containing multiple heavy metals. A sorbent of ZnS nanocrystals (NCs) was synthesized and showed extraordinary performance for the removal of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ . The removal efficiencies of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ were 99.9%, 99.9%, 90.8% and 66.3%, respectively. Meanwhile, it was determined that solubility product (K sp ) of heavy metal sulfides was closely related to adsorption selectivity of various heavy metals on the sorbent. The removal efficiency of Hg 2+ was higher than that of Cd 2+ , while the K sp of HgS was lower than that of CdS. It indicated that preferential adsorption of heavy metals occurred when the K sp of the heavy metal sulfide was lower. In addition, the differences in the K sp of heavy metal sulfides allowed for the exchange of heavy metals, indicating the potential application for the sequential removal and separation of heavy metals from wastewater. According to the cumulative adsorption experimental results, multiple heavy metals were sequentially adsorbed and separated from the simulated wastewater in the order of the K sp of their sulfides. This method holds the promise of sequentially removing and separating multiple heavy metals from wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

Information Retrieval: A Sequential Learning Process.

ERIC Educational Resources Information Center

Bookstein, Abraham

1983-01-01

Presents decision-theoretic models which intrinsically include retrieval of multiple documents whereby system responds to request by presenting documents to patron in sequence, gathering feedback, and using information to modify future retrievals. Document independence model, set retrieval model, sequential retrieval model, learning model,…

Robustness of the sequential lineup advantage.

PubMed

Gronlund, Scott D; Carlson, Curt A; Dailey, Sarah B; Goodsell, Charles A

2009-06-01

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Maternal Risk Factors for Fetal Alcohol Spectrum Disorders in a Province in Italy*

PubMed Central

Ceccanti, Mauro; Fiorentino, Daniela; Coriale, Giovanna; Kalberg, Wendy O.; Buckley, David; Hoyme, H. Eugene; Gossage, J. Phillip; Robinson, Luther K.; Manning, Melanie; Romeo, Marina; Hasken, Julie M.; Tabachnick, Barbara; Blankenship, Jason

2016-01-01

Background Maternal risk factors for fetal alcohol spectrum disorders (FASD) in Italy and Mediterranean cultures need clarification, as there are few studies and most are plagued by inaccurate reporting of antenatal alcohol use. Methods Maternal interviews (n=905) were carried out in a population-based study of the prevalence and characteristics of FASD in the Lazio region of Italy which provided data for multivariate case control comparisons and multiple correlation models. Results Case control findings from interviews seven years post-partum indicate that mothers of children with FASD are significantly more likely than randomly-selected controls or community mothers to: be shorter; have higher body mass indexes (BMI); be married to a man with legal problems; report more drinking three months pre-pregnancy; engage in more current drinking and drinking alone; and have alcohol problems in her family. Logistic regression analysis of multiple candidate predictors of a FASD diagnosis indicates that alcohol problems in the child’s family is the most significant risk factor, making a diagnosis within the continuum of FASD 9 times more likely (95% C.I. = 1.6 to 50.7). Sequential multiple regression analysis of the child’s neuropsychological performance also identifies alcohol problems in the child’s family as the only significant maternal risk variable (p<.001) when controlling for other potential risk factors. Conclusions Underreporting of prenatal alcohol use has been demonstrated among Italian and other Mediterranean antenatal samples, and it was suspected in this sample. Nevertheless, several significant maternal risk factors for FASD have been identified. PMID:25456331

Maternal risk factors for fetal alcohol spectrum disorders in a province in Italy.

PubMed

Ceccanti, Mauro; Fiorentino, Daniela; Coriale, Giovanna; Kalberg, Wendy O; Buckley, David; Hoyme, H Eugene; Gossage, J Phillip; Robinson, Luther K; Manning, Melanie; Romeo, Marina; Hasken, Julie M; Tabachnick, Barbara; Blankenship, Jason; May, Philip A

2014-12-01

Maternal risk factors for fetal alcohol spectrum disorders (FASD) in Italy and Mediterranean cultures need clarification, as there are few studies and most are plagued by inaccurate reporting of antenatal alcohol use. Maternal interviews (n = 905) were carried out in a population-based study of the prevalence and characteristics of FASD in the Lazio region of Italy which provided data for multivariate case control comparisons and multiple correlation models. Case control findings from interviews seven years post-partum indicate that mothers of children with FASD are significantly more likely than randomly-selected controls or community mothers to: be shorter; have higher body mass indexes (BMI); be married to a man with legal problems; report more drinking three months pre-pregnancy; engage in more current drinking and drinking alone; and have alcohol problems in her family. Logistic regression analysis of multiple candidate predictors of a FASD diagnosis indicates that alcohol problems in the child's family is the most significant risk factor, making a diagnosis within the continuum of FASD 9 times more likely (95%C.I. = 1.6 to 50.7). Sequential multiple regression analysis of the child's neuropsychological performance also identifies alcohol problems in the child's family as the only significant maternal risk variable (p < .001) when controlling for other potential risk factors. Underreporting of prenatal alcohol use has been demonstrated among Italian and other Mediterranean antenatal samples, and it was suspected in this sample. Nevertheless, several significant maternal risk factors for FASD have been identified. Copyright © 2014. Published by Elsevier Ireland Ltd.

High speed polling protocol for multiple node network with sequential flooding of a polling message and a poll-answering message

NASA Technical Reports Server (NTRS)

Marvit, Maclen (Inventor); Kirkham, Harold (Inventor)

1995-01-01

The invention is a multiple interconnected network of intelligent message-repeating remote nodes which employs a remote node polling process performed by a master node by transmitting a polling message generically addressed to all remote nodes associated with the master node. Each remote node responds upon receipt of the generically addressed polling message by sequentially flooding the network with a poll-answering informational message and with the polling message.

Modeling Complex Equilibria in ITC Experiments: Thermodynamic Parameters Estimation for a Three Binding Site Model

PubMed Central

Le, Vu H.; Buscaglia, Robert; Chaires, Jonathan B.; Lewis, Edwin A.

2013-01-01

Isothermal Titration Calorimetry, ITC, is a powerful technique that can be used to estimate a complete set of thermodynamic parameters (e.g. Keq (or ΔG), ΔH, ΔS, and n) for a ligand binding interaction described by a thermodynamic model. Thermodynamic models are constructed by combination of equilibrium constant, mass balance, and charge balance equations for the system under study. Commercial ITC instruments are supplied with software that includes a number of simple interaction models, for example one binding site, two binding sites, sequential sites, and n-independent binding sites. More complex models for example, three or more binding sites, one site with multiple binding mechanisms, linked equilibria, or equilibria involving macromolecular conformational selection through ligand binding need to be developed on a case by case basis by the ITC user. In this paper we provide an algorithm (and a link to our MATLAB program) for the non-linear regression analysis of a multiple binding site model with up to four overlapping binding equilibria. Error analysis demonstrates that fitting ITC data for multiple parameters (e.g. up to nine parameters in the three binding site model) yields thermodynamic parameters with acceptable accuracy. PMID:23262283

Adults' strategies for simple addition and multiplication: verbal self-reports and the operand recognition paradigm.

PubMed

Metcalfe, Arron W S; Campbell, Jamie I D

2011-05-01

Accurate measurement of cognitive strategies is important in diverse areas of psychological research. Strategy self-reports are a common measure, but C. Thevenot, M. Fanget, and M. Fayol (2007) proposed a more objective method to distinguish different strategies in the context of mental arithmetic. In their operand recognition paradigm, speed of recognition memory for problem operands after solving a problem indexes strategy (e.g., direct memory retrieval vs. a procedural strategy). Here, in 2 experiments, operand recognition time was the same following simple addition or multiplication, but, consistent with a wide variety of previous research, strategy reports indicated much greater use of procedures (e.g., counting) for addition than multiplication. Operation, problem size (e.g., 2 + 3 vs. 8 + 9), and operand format (digits vs. words) had interactive effects on reported procedure use that were not reflected in recognition performance. Regression analyses suggested that recognition time was influenced at least as much by the relative difficulty of the preceding problem as by the strategy used. The findings indicate that the operand recognition paradigm is not a reliable substitute for strategy reports and highlight the potential impact of difficulty-related carryover effects in sequential cognitive tasks.

Least-squares sequential parameter and state estimation for large space structures

NASA Technical Reports Server (NTRS)

Thau, F. E.; Eliazov, T.; Montgomery, R. C.

1982-01-01

This paper presents the formulation of simultaneous state and parameter estimation problems for flexible structures in terms of least-squares minimization problems. The approach combines an on-line order determination algorithm, with least-squares algorithms for finding estimates of modal approximation functions, modal amplitudes, and modal parameters. The approach combines previous results on separable nonlinear least squares estimation with a regression analysis formulation of the state estimation problem. The technique makes use of sequential Householder transformations. This allows for sequential accumulation of matrices required during the identification process. The technique is used to identify the modal prameters of a flexible beam.

Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems.

PubMed

Harari, Colin M; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T; Lubner, Meghan G; Hinshaw, J Louis; Ziemlewicz, Timothy; Brace, Christopher L

2016-01-01

To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P < .05). Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P < .05). Ablations were generally smaller in vivo compared with ex vivo. The use of multiple antennas and simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015.

Development of a standardized sequential extraction protocol for simultaneous extraction of multiple actinide elements

DOE PAGES

Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.; ...

2017-02-07

Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

Data Networks Reliability

DTIC Science & Technology

1988-10-03

full achievable region is achievable if there is only a bounded degree of asynchronism. E. Arikan , in a Ph.D. thesis [Ari85], extended sequential...real co-operation is required to reduce the number of transmissions to O(log log N). 14 REFERENCES [Ari85] E. Arikan , "Sequential Decoding for Multiple

Humanizing Outgroups Through Multiple Categorization

PubMed Central

Prati, Francesca; Crisp, Richard J.; Meleady, Rose; Rubini, Monica

2016-01-01

In three studies, we examined the impact of multiple categorization on intergroup dehumanization. Study 1 showed that perceiving members of a rival university along multiple versus simple categorical dimensions enhanced the tendency to attribute human traits to this group. Study 2 showed that multiple versus simple categorization of immigrants increased the attribution of uniquely human emotions to them. This effect was explained by the sequential mediation of increased individuation of the outgroup and reduced outgroup threat. Study 3 replicated this sequential mediation model and introduced a novel way of measuring humanization in which participants generated attributes corresponding to the outgroup in a free response format. Participants generated more uniquely human traits in the multiple versus simple categorization conditions. We discuss the theoretical implications of these findings and consider their role in informing and improving efforts to ameliorate contemporary forms of intergroup discrimination. PMID:26984016

Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis

PubMed Central

Schwendicke, Falk; Göstemeyer, Gerd

2017-01-01

Objectives Single-visit root canal treatment has some advantages over conventional multivisit treatment, but might increase the risk of complications. We systematically evaluated the risk of complications after single-visit or multiple-visit root canal treatment using meta-analysis and trial-sequential analysis. Data Controlled trials comparing single-visit versus multiple-visit root canal treatment of permanent teeth were included. Trials needed to assess the risk of long-term complications (pain, infection, new/persisting/increasing periapical lesions ≥1 year after treatment), short-term pain or flare-up (acute exacerbation of initiation or continuation of root canal treatment). Sources Electronic databases (PubMed, EMBASE, Cochrane Central) were screened, random-effects meta-analyses performed and trial-sequential analysis used to control for risk of random errors. Evidence was graded according to GRADE. Study selection 29 trials (4341 patients) were included, all but 6 showing high risk of bias. Based on 10 trials (1257 teeth), risk of complications was not significantly different in single-visit versus multiple-visit treatment (risk ratio (RR) 1.00 (95% CI 0.75 to 1.35); weak evidence). Based on 20 studies (3008 teeth), risk of pain did not significantly differ between treatments (RR 0.99 (95% CI 0.76 to 1.30); moderate evidence). Risk of flare-up was recorded by 8 studies (1110 teeth) and was significantly higher after single-visit versus multiple-visit treatment (RR 2.13 (95% CI 1.16 to 3.89); very weak evidence). Trial-sequential analysis revealed that firm evidence for benefit, harm or futility was not reached for any of the outcomes. Conclusions There is insufficient evidence to rule out whether important differences between both strategies exist. Clinical significance Dentists can provide root canal treatment in 1 or multiple visits. Given the possibly increased risk of flare-ups, multiple-visit treatment might be preferred for certain teeth (eg, those with periapical lesions). PMID:28148534

Processing of Sequential and Holistic Stimuli in Left and Right Visual Fields,

DTIC Science & Technology

1980-10-01

1 7 A-A091 588 AIR =FORCE ACADEMY CO IF/G 5/10 I PROCESSING OF SEQUENTIAL AND HOLISTIC STIMULI IN LEFT AND RIGHT--ETC( U ) OCT 80 E H GALLUSCIO. D A...neocortical commissures sectioned to reduce grand mal seizures have added significantly to 1.. ... . ....... .......- , l - ’ ’ . .... . .. ’ r U I l...REALISTIC AUTISTIC MASLOW RATIONAL INTUITIVE MILNER VERBAL NON-VERBAL NEISSER SEQUENTIAL MULTIPLE ORNSTEIN ANALYTIC HOLISTIC C. S. PEIRCE EXPLICATIVE

Precise Sequential DNA Ligation on A Solid Substrate: Solid-Based Rapid Sequential Ligation of Multiple DNA Molecules

PubMed Central

Takita, Eiji; Kohda, Katsunori; Tomatsu, Hajime; Hanano, Shigeru; Moriya, Kanami; Hosouchi, Tsutomu; Sakurai, Nozomu; Suzuki, Hideyuki; Shinmyo, Atsuhiko; Shibata, Daisuke

2013-01-01

Ligation, the joining of DNA fragments, is a fundamental procedure in molecular cloning and is indispensable to the production of genetically modified organisms that can be used for basic research, the applied biosciences, or both. Given that many genes cooperate in various pathways, incorporating multiple gene cassettes in tandem in a transgenic DNA construct for the purpose of genetic modification is often necessary when generating organisms that produce multiple foreign gene products. Here, we describe a novel method, designated PRESSO (precise sequential DNA ligation on a solid substrate), for the tandem ligation of multiple DNA fragments. We amplified donor DNA fragments with non-palindromic ends, and ligated the fragment to acceptor DNA fragments on solid beads. After the final donor DNA fragments, which included vector sequences, were joined to the construct that contained the array of fragments, the ligation product (the construct) was thereby released from the beads via digestion with a rare-cut meganuclease; the freed linear construct was circularized via an intra-molecular ligation. PRESSO allowed us to rapidly and efficiently join multiple genes in an optimized order and orientation. This method can overcome many technical challenges in functional genomics during the post-sequencing generation. PMID:23897972

S.M.P. SEQUENTIAL MATHEMATICS PROGRAM.

ERIC Educational Resources Information Center

CICIARELLI, V; LEONARD, JOSEPH

A SEQUENTIAL MATHEMATICS PROGRAM BEGINNING WITH THE BASIC FUNDAMENTALS ON THE FOURTH GRADE LEVEL IS PRESENTED. INCLUDED ARE AN UNDERSTANDING OF OUR NUMBER SYSTEM, AND THE BASIC OPERATIONS OF WORKING WITH WHOLE NUMBERS--ADDITION, SUBTRACTION, MULTIPLICATION, AND DIVISION. COMMON FRACTIONS ARE TAUGHT IN THE FIFTH, SIXTH, AND SEVENTH GRADES. A…

Dose finding with the sequential parallel comparison design.

PubMed

Wang, Jessie J; Ivanova, Anastasia

2014-01-01

The sequential parallel comparison design (SPCD) is a two-stage design recommended for trials with possibly high placebo response. A drug-placebo comparison in the first stage is followed in the second stage by placebo nonresponders being re-randomized between drug and placebo. We describe how SPCD can be used in trials where multiple doses of a drug or multiple treatments are compared with placebo and present two adaptive approaches. We detail how to analyze data in such trials and give recommendations about the allocation proportion to placebo in the two stages of SPCD.

Constrained multiple indicator kriging using sequential quadratic programming

NASA Astrophysics Data System (ADS)

Soltani-Mohammadi, Saeed; Erhan Tercan, A.

2012-11-01

Multiple indicator kriging (MIK) is a nonparametric method used to estimate conditional cumulative distribution functions (CCDF). Indicator estimates produced by MIK may not satisfy the order relations of a valid CCDF which is ordered and bounded between 0 and 1. In this paper a new method has been presented that guarantees the order relations of the cumulative distribution functions estimated by multiple indicator kriging. The method is based on minimizing the sum of kriging variances for each cutoff under unbiasedness and order relations constraints and solving constrained indicator kriging system by sequential quadratic programming. A computer code is written in the Matlab environment to implement the developed algorithm and the method is applied to the thickness data.

Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems

PubMed Central

Harari, Colin M.; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T.; Lubner, Meghan G.; Hinshaw, J. Louis; Ziemlewicz, Timothy

2016-01-01

Purpose To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. Materials and Methods All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. Results On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P < .05). Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P < .05). Ablations were generally smaller in vivo compared with ex vivo. Conclusion The use of multiple antennas and simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015 PMID:26133361

One-step global parameter estimation of kinetic inactivation parameters for Bacillus sporothermodurans spores under static and dynamic thermal processes.

PubMed

Cattani, F; Dolan, K D; Oliveira, S D; Mishra, D K; Ferreira, C A S; Periago, P M; Aznar, A; Fernandez, P S; Valdramidis, V P

2016-11-01

Bacillus sporothermodurans produces highly heat-resistant endospores, that can survive under ultra-high temperature. High heat-resistant sporeforming bacteria are one of the main causes for spoilage and safety of low-acid foods. They can be used as indicators or surrogates to establish the minimum requirements for heat processes, but it is necessary to understand their thermal inactivation kinetics. The aim of the present work was to study the inactivation kinetics under both static and dynamic conditions in a vegetable soup. Ordinary least squares one-step regression and sequential procedures were applied for estimating these parameters. Results showed that multiple dynamic heating profiles, when analyzed simultaneously, can be used to accurately estimate the kinetic parameters while significantly reducing estimation errors and data collection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative structure-retention relationships for gas chromatographic retention indices of alkylbenzenes with molecular graph descriptors.

PubMed

Ivanciuc, O; Ivanciuc, T; Klein, D J; Seitz, W A; Balaban, A T

2001-02-01

Quantitative structure-retention relationships (QSRR) represent statistical models that quantify the connection between the molecular structure and the chromatographic retention indices of organic compounds, allowing the prediction of retention indices of novel, not yet synthesized compounds, solely from their structural descriptors. Using multiple linear regression, QSRR models for the gas chromatographic Kováts retention indices of 129 alkylbenzenes are generated using molecular graph descriptors. The correlational ability of structural descriptors computed from 10 molecular matrices is investigated, showing that the novel reciprocal matrices give numerical indices with improved correlational ability. A QSRR equation with 5 graph descriptors gives the best calibration and prediction results, demonstrating the usefulness of the molecular graph descriptors in modeling chromatographic retention parameters. The sequential orthogonalization of descriptors suggests simpler QSRR models by eliminating redundant structural information.

Genetic Parallel Programming: design and implementation.

PubMed

Cheang, Sin Man; Leung, Kwong Sak; Lee, Kin Hong

2006-01-01

This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially.

RACE/A: an architectural account of the interactions between learning, task control, and retrieval dynamics.

PubMed

van Maanen, Leendert; van Rijn, Hedderik; Taatgen, Niels

2012-01-01

This article discusses how sequential sampling models can be integrated in a cognitive architecture. The new theory Retrieval by Accumulating Evidence in an Architecture (RACE/A) combines the level of detail typically provided by sequential sampling models with the level of task complexity typically provided by cognitive architectures. We will use RACE/A to model data from two variants of a picture-word interference task in a psychological refractory period design. These models will demonstrate how RACE/A enables interactions between sequential sampling and long-term declarative learning, and between sequential sampling and task control. In a traditional sequential sampling model, the onset of the process within the task is unclear, as is the number of sampling processes. RACE/A provides a theoretical basis for estimating the onset of sequential sampling processes during task execution and allows for easy modeling of multiple sequential sampling processes within a task. Copyright © 2011 Cognitive Science Society, Inc.

Investigating Stage-Sequential Growth Mixture Models with Multiphase Longitudinal Data

ERIC Educational Resources Information Center

Kim, Su-Young; Kim, Jee-Seon

2012-01-01

This article investigates three types of stage-sequential growth mixture models in the structural equation modeling framework for the analysis of multiple-phase longitudinal data. These models can be important tools for situations in which a single-phase growth mixture model produces distorted results and can allow researchers to better understand…

Synthesizing genetic sequential logic circuit with clock pulse generator.

PubMed

Chuang, Chia-Hua; Lin, Chun-Liang

2014-05-28

Rhythmic clock widely occurs in biological systems which controls several aspects of cell physiology. For the different cell types, it is supplied with various rhythmic frequencies. How to synthesize a specific clock signal is a preliminary but a necessary step to further development of a biological computer in the future. This paper presents a genetic sequential logic circuit with a clock pulse generator based on a synthesized genetic oscillator, which generates a consecutive clock signal whose frequency is an inverse integer multiple to that of the genetic oscillator. An analogous electronic waveform-shaping circuit is constructed by a series of genetic buffers to shape logic high/low levels of an oscillation input in a basic sinusoidal cycle and generate a pulse-width-modulated (PWM) output with various duty cycles. By controlling the threshold level of the genetic buffer, a genetic clock pulse signal with its frequency consistent to the genetic oscillator is synthesized. A synchronous genetic counter circuit based on the topology of the digital sequential logic circuit is triggered by the clock pulse to synthesize the clock signal with an inverse multiple frequency to the genetic oscillator. The function acts like a frequency divider in electronic circuits which plays a key role in the sequential logic circuit with specific operational frequency. A cascaded genetic logic circuit generating clock pulse signals is proposed. Based on analogous implement of digital sequential logic circuits, genetic sequential logic circuits can be constructed by the proposed approach to generate various clock signals from an oscillation signal.

Patterns of Drug Use, Risky Behavior, and Health Status Among Persons Who Inject Drugs Living in San Diego, California: A Latent Class Analysis

PubMed Central

Roth, Alexis M.; Armenta, Richard A.; Wagner, Karla D.; Roesch, Scott C.; Bluthenthal, Ricky N.; Cuevas-Mota, Jazmine; Garfein, Richard S.

2015-01-01

Background Among persons who inject drugs (PWID), polydrug use (the practice of mixing multiple drugs/alcohol sequentially or simultaneously) increases risk for HIV transmission and unintentional overdose deaths. Research has shown local drug markets influence drug use practices. However, little is known about the impact of drug mixing in markets dominated by black tar heroin and methamphetamine, such as the western United States. Methods Data were collected through an ongoing longitudinal study examining drug use, risk behavior, and health status among PWID. Latent class analysis (LCA) was used to identify patterns of substance use (heroin, methamphetamine, prescription drugs, alcohol, and marijuana) via multiple administration routes (injecting, smoking, and swallowing). Logistic regression was used to identify behaviors and health indicators associated with drug use class. Results The sample included 511 mostly white (51.5%) males (73.8%), with mean age of 43.5 years. Two distinct classes of drug users predominated: methamphetamine by multiple routes (51%) and heroin by injection (49%). In multivariable logistic regression, class membership was associated with age, race, and housing status. PWID who were HIV-seropositive and reported prior sexually transmitted infections had increased odds of belonging to the methamphetamine class. Those who were HCV positive and reported previous opioid overdose had an increased odds of being in the primarily heroin injection class (all P-values < .05). Conclusion Risk behaviors and health outcomes differed between PWID who primarily inject heroin vs. those who use methamphetamine. The findings suggest that in a region where PWID mainly use black tar heroin or methamphetamine, interventions tailored to sub-populations of PWID could improve effectiveness. PMID:25313832

Comparison of regression and geostatistical methods for mapping Leaf Area Index (LAI) with Landsat ETM+ data over a boreal forest.

Treesearch

Mercedes Berterretche; Andrew T. Hudak; Warren B. Cohen; Thomas K. Maiersperger; Stith T. Gower; Jennifer Dungan

2005-01-01

This study compared aspatial and spatial methods of using remote sensing and field data to predict maximum growing season leaf area index (LAI) maps in a boreal forest in Manitoba, Canada. The methods tested were orthogonal regression analysis (reduced major axis, RMA) and two geostatistical techniques: kriging with an external drift (KED) and sequential Gaussian...

Estimating the optimal dynamic antipsychotic treatment regime: Evidence from the sequential multiple assignment randomized CATIE Schizophrenia Study

PubMed Central

Shortreed, Susan M.; Moodie, Erica E. M.

2012-01-01

Summary Treatment of schizophrenia is notoriously difficult and typically requires personalized adaption of treatment due to lack of efficacy of treatment, poor adherence, or intolerable side effects. The Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) Schizophrenia Study is a sequential multiple assignment randomized trial comparing the typical antipsychotic medication, perphenazine, to several newer atypical antipsychotics. This paper describes the marginal structural modeling method for estimating optimal dynamic treatment regimes and applies the approach to the CATIE Schizophrenia Study. Missing data and valid estimation of confidence intervals are also addressed. PMID:23087488

A Robust Real Time Direction-of-Arrival Estimation Method for Sequential Movement Events of Vehicles.

PubMed

Liu, Huawei; Li, Baoqing; Yuan, Xiaobing; Zhou, Qianwei; Huang, Jingchang

2018-03-27

Parameters estimation of sequential movement events of vehicles is facing the challenges of noise interferences and the demands of portable implementation. In this paper, we propose a robust direction-of-arrival (DOA) estimation method for the sequential movement events of vehicles based on a small Micro-Electro-Mechanical System (MEMS) microphone array system. Inspired by the incoherent signal-subspace method (ISM), the method that is proposed in this work employs multiple sub-bands, which are selected from the wideband signals with high magnitude-squared coherence to track moving vehicles in the presence of wind noise. The field test results demonstrate that the proposed method has a better performance in emulating the DOA of a moving vehicle even in the case of severe wind interference than the narrowband multiple signal classification (MUSIC) method, the sub-band DOA estimation method, and the classical two-sided correlation transformation (TCT) method.

Multi-Phenotypic subtyping of circulating tumor cells using sequential fluorescent quenching and restaining

NASA Astrophysics Data System (ADS)

Adams, Daniel L.; Alpaugh, R. Katherine; Tsai, Susan; Tang, Cha-Mei; Stefansson, Steingrimur

2016-09-01

In tissue biopsies formalin fixed paraffin embedded cancer blocks are micro-sectioned producing multiple semi-identical specimens which are analyzed and subtyped proteomically, and genomically, with numerous biomarkers. In blood based biopsies (BBBs), blood is purified for circulating tumor cells (CTCs) and clinical utility is typically limited to cell enumeration, as only 2-3 positive fluorescent markers and 1 negative marker can be used. As such, increasing the number of subtyping biomarkers on each individual CTC could dramatically enhance the clinical utility of BBBs, allowing in depth interrogation of clinically relevant CTCs. We describe a simple and inexpensive method for quenching the specific fluors of fluorescently stained CTCs followed by sequential restaining with additional biomarkers. As proof of principle a CTC panel, immunosuppression panel and stem cell panel were used to sequentially subtype individual fluorescently stained patient CTCs, suggesting a simple and universal technique to analyze multiple clinically applicable immunomarkers from BBBs.

Using Priced Options to Solve the Exposure Problem in Sequential Auctions

NASA Astrophysics Data System (ADS)

Mous, Lonneke; Robu, Valentin; La Poutré, Han

This paper studies the benefits of using priced options for solving the exposure problem that bidders with valuation synergies face when participating in multiple, sequential auctions. We consider a model in which complementary-valued items are auctioned sequentially by different sellers, who have the choice of either selling their good directly or through a priced option, after fixing its exercise price. We analyze this model from a decision-theoretic perspective and we show, for a setting where the competition is formed by local bidders, that using options can increase the expected profit for both buyers and sellers. Furthermore, we derive the equations that provide minimum and maximum bounds between which a synergy buyer's bids should fall in order for both sides to have an incentive to use the options mechanism. Next, we perform an experimental analysis of a market in which multiple synergy bidders are active simultaneously.

Double-blind photo lineups using actual eyewitnesses: an experimental test of a sequential versus simultaneous lineup procedure.

PubMed

Wells, Gary L; Steblay, Nancy K; Dysart, Jennifer E

2015-02-01

Eyewitnesses (494) to actual crimes in 4 police jurisdictions were randomly assigned to view simultaneous or sequential photo lineups using laptop computers and double-blind administration. The sequential procedure used in the field experiment mimicked how it is conducted in actual practice (e.g., using a continuation rule, witness does not know how many photos are to be viewed, witnesses resolve any multiple identifications), which is not how most lab experiments have tested the sequential lineup. No significant differences emerged in rates of identifying lineup suspects (25% overall) but the sequential procedure produced a significantly lower rate (11%) of identifying known-innocent lineup fillers than did the simultaneous procedure (18%). The simultaneous/sequential pattern did not significantly interact with estimator variables and no lineup-position effects were observed for either the simultaneous or sequential procedures. Rates of nonidentification were not significantly different for simultaneous and sequential but nonidentifiers from the sequential procedure were more likely to use the "not sure" response option than were nonidentifiers from the simultaneous procedure. Among witnesses who made an identification, 36% (41% of simultaneous and 32% of sequential) identified a known-innocent filler rather than a suspect, indicating that eyewitness performance overall was very poor. The results suggest that the sequential procedure that is used in the field reduces the identification of known-innocent fillers, but the differences are relatively small.

Randomized Controlled Trial for Behavioral Smoking and Weight Control Treatment: Effect of Concurrent Versus Sequential Intervention.

ERIC Educational Resources Information Center

Spring, Bonnie; Pagoto, Sherry; Pingitore, Regina; Doran, Neal; Schneider, Kristin; Hedeker, Don

2004-01-01

The authors compared simultaneous versus sequential approaches to multiple health behavior change in diet, exercise, and cigarette smoking. Female regular smokers (N = 315) randomized to 3 conditions received 16 weeks of behavioral smoking treatment, quit smoking at Week 5, and were followed for 9 months after quit date. Weight management was…

Extending the Simultaneous-Sequential Paradigm to Measure Perceptual Capacity for Features and Words

ERIC Educational Resources Information Center

Scharff, Alec; Palmer, John; Moore, Cathleen M.

2011-01-01

In perception, divided attention refers to conditions in which multiple stimuli are relevant to an observer. To measure the effect of divided attention in terms of perceptual capacity, we introduce an extension of the simultaneous-sequential paradigm. The extension makes predictions for fixed-capacity models as well as for unlimited-capacity…

Gold-catalyzed sequential annulations towards 3,4-fused bi/tri-cyclic furans involving a [3+2+2]-cycloaddition.

PubMed

Liu, Suna; Yang, Pu; Peng, Shiyong; Zhu, Chenghao; Cao, Shengyu; Li, Jian; Sun, Jiangtao

2017-01-17

A gold-catalyzed sequential annulation reaction to prepare 3,4-fused bicyclic furan compounds has been realized by employing 2-(1-alkynyl)-2-alken-1-ones and 1,3,5-triazines as the starting materials under mild reaction conditions. This protocol features multiple bond formation in a single operation with the incorporation of two nitrogen and two carbon atoms into the final products. A mechanistic investigation reveals that the sequential annulations involved an unprecedented stepwise [3+2+2]-cycloaddition.

Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis.

PubMed

Schwendicke, Falk; Göstemeyer, Gerd

2017-02-01

Single-visit root canal treatment has some advantages over conventional multivisit treatment, but might increase the risk of complications. We systematically evaluated the risk of complications after single-visit or multiple-visit root canal treatment using meta-analysis and trial-sequential analysis. Controlled trials comparing single-visit versus multiple-visit root canal treatment of permanent teeth were included. Trials needed to assess the risk of long-term complications (pain, infection, new/persisting/increasing periapical lesions ≥1 year after treatment), short-term pain or flare-up (acute exacerbation of initiation or continuation of root canal treatment). Electronic databases (PubMed, EMBASE, Cochrane Central) were screened, random-effects meta-analyses performed and trial-sequential analysis used to control for risk of random errors. Evidence was graded according to GRADE. 29 trials (4341 patients) were included, all but 6 showing high risk of bias. Based on 10 trials (1257 teeth), risk of complications was not significantly different in single-visit versus multiple-visit treatment (risk ratio (RR) 1.00 (95% CI 0.75 to 1.35); weak evidence). Based on 20 studies (3008 teeth), risk of pain did not significantly differ between treatments (RR 0.99 (95% CI 0.76 to 1.30); moderate evidence). Risk of flare-up was recorded by 8 studies (1110 teeth) and was significantly higher after single-visit versus multiple-visit treatment (RR 2.13 (95% CI 1.16 to 3.89); very weak evidence). Trial-sequential analysis revealed that firm evidence for benefit, harm or futility was not reached for any of the outcomes. There is insufficient evidence to rule out whether important differences between both strategies exist. Dentists can provide root canal treatment in 1 or multiple visits. Given the possibly increased risk of flare-ups, multiple-visit treatment might be preferred for certain teeth (eg, those with periapical lesions). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Q-learning residual analysis: application to the effectiveness of sequences of antipsychotic medications for patients with schizophrenia.

PubMed

Ertefaie, Ashkan; Shortreed, Susan; Chakraborty, Bibhas

2016-06-15

Q-learning is a regression-based approach that uses longitudinal data to construct dynamic treatment regimes, which are sequences of decision rules that use patient information to inform future treatment decisions. An optimal dynamic treatment regime is composed of a sequence of decision rules that indicate how to optimally individualize treatment using the patients' baseline and time-varying characteristics to optimize the final outcome. Constructing optimal dynamic regimes using Q-learning depends heavily on the assumption that regression models at each decision point are correctly specified; yet model checking in the context of Q-learning has been largely overlooked in the current literature. In this article, we show that residual plots obtained from standard Q-learning models may fail to adequately check the quality of the model fit. We present a modified Q-learning procedure that accommodates residual analyses using standard tools. We present simulation studies showing the advantage of the proposed modification over standard Q-learning. We illustrate this new Q-learning approach using data collected from a sequential multiple assignment randomized trial of patients with schizophrenia. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Subsonic Aircraft With Regression and Neural-Network Approximators Designed

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Hopkins, Dale A.

2004-01-01

At the NASA Glenn Research Center, NASA Langley Research Center's Flight Optimization System (FLOPS) and the design optimization testbed COMETBOARDS with regression and neural-network-analysis approximators have been coupled to obtain a preliminary aircraft design methodology. For a subsonic aircraft, the optimal design, that is the airframe-engine combination, is obtained by the simulation. The aircraft is powered by two high-bypass-ratio engines with a nominal thrust of about 35,000 lbf. It is to carry 150 passengers at a cruise speed of Mach 0.8 over a range of 3000 n mi and to operate on a 6000-ft runway. The aircraft design utilized a neural network and a regression-approximations-based analysis tool, along with a multioptimizer cascade algorithm that uses sequential linear programming, sequential quadratic programming, the method of feasible directions, and then sequential quadratic programming again. Optimal aircraft weight versus the number of design iterations is shown. The central processing unit (CPU) time to solution is given. It is shown that the regression-method-based analyzer exhibited a smoother convergence pattern than the FLOPS code. The optimum weight obtained by the approximation technique and the FLOPS code differed by 1.3 percent. Prediction by the approximation technique exhibited no error for the aircraft wing area and turbine entry temperature, whereas it was within 2 percent for most other parameters. Cascade strategy was required by FLOPS as well as the approximators. The regression method had a tendency to hug the data points, whereas the neural network exhibited a propensity to follow a mean path. The performance of the neural network and regression methods was considered adequate. It was at about the same level for small, standard, and large models with redundancy ratios (defined as the number of input-output pairs to the number of unknown coefficients) of 14, 28, and 57, respectively. In an SGI octane workstation (Silicon Graphics, Inc., Mountainview, CA), the regression training required a fraction of a CPU second, whereas neural network training was between 1 and 9 min, as given. For a single analysis cycle, the 3-sec CPU time required by the FLOPS code was reduced to milliseconds by the approximators. For design calculations, the time with the FLOPS code was 34 min. It was reduced to 2 sec with the regression method and to 4 min by the neural network technique. The performance of the regression and neural network methods was found to be satisfactory for the analysis and design optimization of the subsonic aircraft.

Sequential Tests of Multiple Hypotheses Controlling Type I and II Familywise Error Rates

PubMed Central

Bartroff, Jay; Song, Jinlin

2014-01-01

This paper addresses the following general scenario: A scientist wishes to perform a battery of experiments, each generating a sequential stream of data, to investigate some phenomenon. The scientist would like to control the overall error rate in order to draw statistically-valid conclusions from each experiment, while being as efficient as possible. The between-stream data may differ in distribution and dimension but also may be highly correlated, even duplicated exactly in some cases. Treating each experiment as a hypothesis test and adopting the familywise error rate (FWER) metric, we give a procedure that sequentially tests each hypothesis while controlling both the type I and II FWERs regardless of the between-stream correlation, and only requires arbitrary sequential test statistics that control the error rates for a given stream in isolation. The proposed procedure, which we call the sequential Holm procedure because of its inspiration from Holm’s (1979) seminal fixed-sample procedure, shows simultaneous savings in expected sample size and less conservative error control relative to fixed sample, sequential Bonferroni, and other recently proposed sequential procedures in a simulation study. PMID:25092948

Real and Non-Real Time Interaction: Unraveling Multiple Threads of Discourse.

ERIC Educational Resources Information Center

Black, Steven D.; And Others

1983-01-01

Compares discourse in several different media and finds that strict sequentiality is not a universal feature of discourse. Concludes that discourse in nonreal time media, such as electronic message systems, has multiple threads. (FL)

Synthesizing genetic sequential logic circuit with clock pulse generator

PubMed Central

2014-01-01

Background Rhythmic clock widely occurs in biological systems which controls several aspects of cell physiology. For the different cell types, it is supplied with various rhythmic frequencies. How to synthesize a specific clock signal is a preliminary but a necessary step to further development of a biological computer in the future. Results This paper presents a genetic sequential logic circuit with a clock pulse generator based on a synthesized genetic oscillator, which generates a consecutive clock signal whose frequency is an inverse integer multiple to that of the genetic oscillator. An analogous electronic waveform-shaping circuit is constructed by a series of genetic buffers to shape logic high/low levels of an oscillation input in a basic sinusoidal cycle and generate a pulse-width-modulated (PWM) output with various duty cycles. By controlling the threshold level of the genetic buffer, a genetic clock pulse signal with its frequency consistent to the genetic oscillator is synthesized. A synchronous genetic counter circuit based on the topology of the digital sequential logic circuit is triggered by the clock pulse to synthesize the clock signal with an inverse multiple frequency to the genetic oscillator. The function acts like a frequency divider in electronic circuits which plays a key role in the sequential logic circuit with specific operational frequency. Conclusions A cascaded genetic logic circuit generating clock pulse signals is proposed. Based on analogous implement of digital sequential logic circuits, genetic sequential logic circuits can be constructed by the proposed approach to generate various clock signals from an oscillation signal. PMID:24884665

System and method for detecting components of a mixture including tooth elements for alignment

DOEpatents

Sommer, Gregory Jon; Schaff, Ulrich Y.

2016-11-22

Examples are described including assay platforms having tooth elements. An impinging element may sequentially engage tooth elements on the assay platform to sequentially align corresponding detection regions with a detection unit. In this manner, multiple measurements may be made of detection regions on the assay platform without necessarily requiring the starting and stopping of a motor.

Combating speckle in SAR images - Vector filtering and sequential classification based on a multiplicative noise model

NASA Technical Reports Server (NTRS)

Lin, Qian; Allebach, Jan P.

1990-01-01

An adaptive vector linear minimum mean-squared error (LMMSE) filter for multichannel images with multiplicative noise is presented. It is shown theoretically that the mean-squared error in the filter output is reduced by making use of the correlation between image bands. The vector and conventional scalar LMMSE filters are applied to a three-band SIR-B SAR, and their performance is compared. Based on a mutliplicative noise model, the per-pel maximum likelihood classifier was derived. The authors extend this to the design of sequential and robust classifiers. These classifiers are also applied to the three-band SIR-B SAR image.

Disentangling formation of multiple-core holes in aminophenol molecules exposed to bright X-FEL radiation

NASA Astrophysics Data System (ADS)

Zhaunerchyk, V.; Kamińska, M.; Mucke, M.; Squibb, R. J.; Eland, J. H. D.; Piancastelli, M. N.; Frasinski, L. J.; Grilj, J.; Koch, M.; McFarland, B. K.; Sistrunk, E.; Gühr, M.; Coffee, R. N.; Bostedt, C.; Bozek, J. D.; Salén, P.; Meulen, P. v. d.; Linusson, P.; Thomas, R. D.; Larsson, M.; Foucar, L.; Ullrich, J.; Motomura, K.; Mondal, S.; Ueda, K.; Richter, R.; Prince, K. C.; Takahashi, O.; Osipov, T.; Fang, L.; Murphy, B. F.; Berrah, N.; Feifel, R.

2015-12-01

Competing multi-photon ionization processes, some leading to the formation of double core hole states, have been examined in 4-aminophenol. The experiments used the linac coherent light source (LCLS) x-ray free electron laser, in combination with a time-of-flight magnetic bottle electron spectrometer and the correlation analysis method of covariance mapping. The results imply that 4-aminophenol molecules exposed to the focused x-ray pulses of the LCLS sequentially absorb more than two x-ray photons, resulting in the formation of multiple core holes as well as in the sequential removal of photoelectrons and Auger electrons (so-called PAPA sequences).

Disentangling formation of multiple-core holes in aminophenol molecules exposed to bright X-FEL radiation

DOE PAGES

Zhaunerchyk, V.; Kaminska, M.; Mucke, M.; ...

2015-10-28

Competing multi-photon ionization processes, some leading to the formation of double core hole states, have been examined in 4-aminophenol. The experiments used the linac coherent light source (LCLS) x-ray free electron laser, in combination with a time-of-flight magnetic bottle electron spectrometer and the correlation analysis method of covariance mapping. Furthermore, the results imply that 4-aminophenol molecules exposed to the focused x-ray pulses of the LCLS sequentially absorb more than two x-ray photons, resulting in the formation of multiple core holes as well as in the sequential removal of photoelectrons and Auger electrons (so-called PAPA sequences).

Program Completion of a Web-Based Tailored Lifestyle Intervention for Adults: Differences between a Sequential and a Simultaneous Approach

PubMed Central

Schneider, Francine; de Vries, Hein; van Osch, Liesbeth ADM; van Nierop, Peter WM; Kremers, Stef PJ

2012-01-01

Background Unhealthy lifestyle behaviors often co-occur and are related to chronic diseases. One effective method to change multiple lifestyle behaviors is web-based computer tailoring. Dropout from Internet interventions, however, is rather high, and it is challenging to retain participants in web-based tailored programs, especially programs targeting multiple behaviors. To date, it is unknown how much information people can handle in one session while taking part in a multiple behavior change intervention, which could be presented either sequentially (one behavior at a time) or simultaneously (all behaviors at once). Objectives The first objective was to compare dropout rates of 2 computer-tailored interventions: a sequential and a simultaneous strategy. The second objective was to assess which personal characteristics are associated with completion rates of the 2 interventions. Methods Using an RCT design, demographics, health status, physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking were self-assessed through web-based questionnaires among 3473 adults, recruited through Regional Health Authorities in the Netherlands in the autumn of 2009. First, a health risk appraisal was offered, indicating whether respondents were meeting the 5 national health guidelines. Second, psychosocial determinants of the lifestyle behaviors were assessed and personal advice was provided, about one or more lifestyle behaviors. Results Our findings indicate a high non-completion rate for both types of intervention (71.0%; n = 2167), with more incompletes in the simultaneous intervention (77.1%; n = 1169) than in the sequential intervention (65.0%; n = 998). In both conditions, discontinuation was predicted by a lower age (sequential condition: OR = 1.04; P < .001; CI = 1.02-1.05; simultaneous condition: OR = 1.04; P < .001; CI = 1.02-1.05) and an unhealthy lifestyle (sequential condition: OR = 0.86; P = .01; CI = 0.76-0.97; simultaneous condition: OR = 0.49; P < .001; CI = 0.42-0.58). In the sequential intervention, being male (OR = 1.27; P = .04; CI = 1.01-1.59) also predicted dropout. When respondents failed to adhere to at least 2 of the guidelines, those receiving the simultaneous intervention were more inclined to drop out than were those receiving the sequential intervention. Conclusion Possible reasons for the higher dropout rate in our simultaneous intervention may be the amount of time required and information overload. Strategies to optimize program completion as well as continued use of computer-tailored interventions should be studied. Trial Registration Dutch Trial Register NTR2168 PMID:22403770

Program completion of a web-based tailored lifestyle intervention for adults: differences between a sequential and a simultaneous approach.

PubMed

Schulz, Daniela N; Schneider, Francine; de Vries, Hein; van Osch, Liesbeth A D M; van Nierop, Peter W M; Kremers, Stef P J

2012-03-08

Unhealthy lifestyle behaviors often co-occur and are related to chronic diseases. One effective method to change multiple lifestyle behaviors is web-based computer tailoring. Dropout from Internet interventions, however, is rather high, and it is challenging to retain participants in web-based tailored programs, especially programs targeting multiple behaviors. To date, it is unknown how much information people can handle in one session while taking part in a multiple behavior change intervention, which could be presented either sequentially (one behavior at a time) or simultaneously (all behaviors at once). The first objective was to compare dropout rates of 2 computer-tailored interventions: a sequential and a simultaneous strategy. The second objective was to assess which personal characteristics are associated with completion rates of the 2 interventions. Using an RCT design, demographics, health status, physical activity, vegetable consumption, fruit consumption, alcohol intake, and smoking were self-assessed through web-based questionnaires among 3473 adults, recruited through Regional Health Authorities in the Netherlands in the autumn of 2009. First, a health risk appraisal was offered, indicating whether respondents were meeting the 5 national health guidelines. Second, psychosocial determinants of the lifestyle behaviors were assessed and personal advice was provided, about one or more lifestyle behaviors. Our findings indicate a high non-completion rate for both types of intervention (71.0%; n = 2167), with more incompletes in the simultaneous intervention (77.1%; n = 1169) than in the sequential intervention (65.0%; n = 998). In both conditions, discontinuation was predicted by a lower age (sequential condition: OR = 1.04; P < .001; CI = 1.02-1.05; simultaneous condition: OR = 1.04; P < .001; CI = 1.02-1.05) and an unhealthy lifestyle (sequential condition: OR = 0.86; P = .01; CI = 0.76-0.97; simultaneous condition: OR = 0.49; P < .001; CI = 0.42-0.58). In the sequential intervention, being male (OR = 1.27; P = .04; CI = 1.01-1.59) also predicted dropout. When respondents failed to adhere to at least 2 of the guidelines, those receiving the simultaneous intervention were more inclined to drop out than were those receiving the sequential intervention. Possible reasons for the higher dropout rate in our simultaneous intervention may be the amount of time required and information overload. Strategies to optimize program completion as well as continued use of computer-tailored interventions should be studied. Dutch Trial Register NTR2168.

Impact of Multiple Pharmacy Use on Medication Adherence and Drug-drug Interactions in Older Adults with Medicare Part D

PubMed Central

Marcum, Zachary A.; Driessen, Julia; Thorpe, Carolyn T.; Gellad, Walid F.; Donohue, Julie M.

2014-01-01

Objective To assess the association between multiple pharmacy use and medication adherence and potential drug-drug interactions (DDIs) among older adults. Design, Setting, and Participants Cross-sectional propensity score-weighted analysis of 2009 claims data from a nationally representative sample of 926,956 Medicare Part D beneficiaries aged >65 continuously enrolled in fee-for-service Medicare and Part D that year, and filled >1 prescription at a community/retail or mail order pharmacy. Multiple pharmacy use was defined as concurrent (overlapping time periods) or sequential use (non-overlapping time periods) of >2 pharmacies in the year. Measurements Medication adherence was calculated using a proportion of days covered ≥0.80 for eight therapeutic categories (β-blockers, renin angiotensin system antagonists, calcium channel blockers, statins, sulfonylureas, biguanides [i.e., metformin], thiazolidinediones, and dipeptidyl peptidase-IV inhibitors). Potential DDIs arising from use of certain drugs across a broad set of classes were defined as the concurrent filling of two interacting drugs. Results Overall, 38.1% of the sample used multiple pharmacies. Those using multiple pharmacies (both concurrently and sequentially) consistently had higher adjusted odds of non-adherence (ranging from 1.10 to 1.31, p<0.001) across all chronic medication classes assessed after controlling for socio-demographic, health status and access to care factors, compared to single pharmacy users. The adjusted predicted probability of exposure to a DDI was also slightly higher for those using multiple pharmacies concurrently (3.6%) compared to single pharmacy users (3.2%, AOR 1.11, 95% CI 1.08–1.15) but lower in individuals using multiple pharmacies sequentially (2.8%, AOR 0.85, 95% CI 0.81–0.91). Conclusions Filling prescriptions at multiple pharmacies was associated with lower medication adherence across multiple chronic medications, and a small but statistically significant increase in DDIs among concurrent pharmacy users. PMID:24521363

A proposed method to detect kinematic differences between and within individuals.

PubMed

Frost, David M; Beach, Tyson A C; McGill, Stuart M; Callaghan, Jack P

2015-06-01

The primary objective was to examine the utility of a novel method of detecting "actual" kinematic changes using the within-subject variation. Twenty firefighters were assigned to one of two groups (lifting or firefighting). Participants performed 25 repetitions of two lifting or firefighting tasks, in three sessions. The magnitude and within-subject variation of several discrete kinematic measures were computed. Sequential averages of each variable were used to derive a cubic, quadratic and linear regression equation. The efficacy of each equation was examined by contrasting participants' sequential means to their 25-trial mean±1SD and 2SD. The magnitude and within-subject variation of each dependent measure was repeatable for all tasks; however, each participant did not exhibit the same movement patterns as the group. The number of instances across all variables, tasks and testing sessions whereby the 25-trial mean±1SD was contained within the boundaries established by the regression equations increased as the aggregate scores included more trials. Each equation achieved success in at least 88% of all instances when three trials were included in the sequential mean (95% with five trials). The within-subject variation may offer a means to examine participant-specific changes without having to collect a large number of trials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Classification and Sequential Pattern Analysis for Improving Managerial Efficiency and Providing Better Medical Service in Public Healthcare Centers

PubMed Central

Chung, Sukhoon; Rhee, Hyunsill; Suh, Yongmoo

2010-01-01

Objectives This study sought to find answers to the following questions: 1) Can we predict whether a patient will revisit a healthcare center? 2) Can we anticipate diseases of patients who revisit the center? Methods For the first question, we applied 5 classification algorithms (decision tree, artificial neural network, logistic regression, Bayesian networks, and Naïve Bayes) and the stacking-bagging method for building classification models. To solve the second question, we performed sequential pattern analysis. Results We determined: 1) In general, the most influential variables which impact whether a patient of a public healthcare center will revisit it or not are personal burden, insurance bill, period of prescription, age, systolic pressure, name of disease, and postal code. 2) The best plain classification model is dependent on the dataset. 3) Based on average of classification accuracy, the proposed stacking-bagging method outperformed all traditional classification models and our sequential pattern analysis revealed 16 sequential patterns. Conclusions Classification models and sequential patterns can help public healthcare centers plan and implement healthcare service programs and businesses that are more appropriate to local residents, encouraging them to revisit public health centers. PMID:21818426

Computed tomography synthesis from magnetic resonance images in the pelvis using multiple random forests and auto-context features

NASA Astrophysics Data System (ADS)

Andreasen, Daniel; Edmund, Jens M.; Zografos, Vasileios; Menze, Bjoern H.; Van Leemput, Koen

2016-03-01

In radiotherapy treatment planning that is only based on magnetic resonance imaging (MRI), the electron density information usually obtained from computed tomography (CT) must be derived from the MRI by synthesizing a so-called pseudo CT (pCT). This is a non-trivial task since MRI intensities are neither uniquely nor quantitatively related to electron density. Typical approaches involve either a classification or regression model requiring specialized MRI sequences to solve intensity ambiguities, or an atlas-based model necessitating multiple registrations between atlases and subject scans. In this work, we explore a machine learning approach for creating a pCT of the pelvic region from conventional MRI sequences without using atlases. We use a random forest provided with information about local texture, edges and spatial features derived from the MRI. This helps to solve intensity ambiguities. Furthermore, we use the concept of auto-context by sequentially training a number of classification forests to create and improve context features, which are finally used to train a regression forest for pCT prediction. We evaluate the pCT quality in terms of the voxel-wise error and the radiologic accuracy as measured by water-equivalent path lengths. We compare the performance of our method against two baseline pCT strategies, which either set all MRI voxels in the subject equal to the CT value of water, or in addition transfer the bone volume from the real CT. We show an improved performance compared to both baseline pCTs suggesting that our method may be useful for MRI-only radiotherapy.

Prediction of rat protein subcellular localization with pseudo amino acid composition based on multiple sequential features.

PubMed

Shi, Ruijia; Xu, Cunshuan

2011-06-01

The study of rat proteins is an indispensable task in experimental medicine and drug development. The function of a rat protein is closely related to its subcellular location. Based on the above concept, we construct the benchmark rat proteins dataset and develop a combined approach for predicting the subcellular localization of rat proteins. From protein primary sequence, the multiple sequential features are obtained by using of discrete Fourier analysis, position conservation scoring function and increment of diversity, and these sequential features are selected as input parameters of the support vector machine. By the jackknife test, the overall success rate of prediction is 95.6% on the rat proteins dataset. Our method are performed on the apoptosis proteins dataset and the Gram-negative bacterial proteins dataset with the jackknife test, the overall success rates are 89.9% and 96.4%, respectively. The above results indicate that our proposed method is quite promising and may play a complementary role to the existing predictors in this area.

Use of personalized Dynamic Treatment Regimes (DTRs) and Sequential Multiple Assignment Randomized Trials (SMARTs) in mental health studies

PubMed Central

Liu, Ying; ZENG, Donglin; WANG, Yuanjia

2014-01-01

Summary Dynamic treatment regimens (DTRs) are sequential decision rules tailored at each point where a clinical decision is made based on each patient’s time-varying characteristics and intermediate outcomes observed at earlier points in time. The complexity, patient heterogeneity, and chronicity of mental disorders call for learning optimal DTRs to dynamically adapt treatment to an individual’s response over time. The Sequential Multiple Assignment Randomized Trial (SMARTs) design allows for estimating causal effects of DTRs. Modern statistical tools have been developed to optimize DTRs based on personalized variables and intermediate outcomes using rich data collected from SMARTs; these statistical methods can also be used to recommend tailoring variables for designing future SMART studies. This paper introduces DTRs and SMARTs using two examples in mental health studies, discusses two machine learning methods for estimating optimal DTR from SMARTs data, and demonstrates the performance of the statistical methods using simulated data. PMID:25642116

[Pay attention to the application of the international intraocular retinoblastoma classification and sequential multiple modality treatment].

PubMed

Fan, X Q

2017-08-11

Retinoblastoma (RB) is the most common intraocular malignancy in childhood. It may seriously affect vision, and even threaten the life. The early diagnosis rate of RB in China remains low, and the majority of patients are at late phase with high rates of enucleation and mortality. The International Intraocular Retinoblastoma Classification and TNM staging system are guidances for therapeutic choices and bases for prognosis evaluation. Based on the sequential multi-method treatment modality, chemotherapy combined with local therapy is the mainstream in dealing with RB, which may maximize the results of eye saving and even vision retaining. New therapeutic techniques including supra-selective ophthalmic artery interventional chemotherapy and intravitreal chemotherapy can further improve the efficacy of treatment, especially the eye salvage rate. The overall level of RB treatment should be improved by promoting the international staging, new therapeutic techniques, and the sequential multiple modality treatment. (Chin J Ophthalmol, 2017, 53: 561 - 565) .

Accelerated drug release and clearance of PEGylated epirubicin liposomes following repeated injections: a new challenge for sequential low-dose chemotherapy

PubMed Central

Yang, Qiang; Ma, Yanling; Zhao, Yongxue; She, Zhennan; Wang, Long; Li, Jie; Wang, Chunling; Deng, Yihui

2013-01-01

Background Sequential low-dose chemotherapy has received great attention for its unique advantages in attenuating multidrug resistance of tumor cells. Nevertheless, it runs the risk of producing new problems associated with the accelerated blood clearance phenomenon, especially with multiple injections of PEGylated liposomes. Methods Liposomes were labeled with fluorescent phospholipids of 1,2-dipalmitoyl-snglycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) and epirubicin (EPI). The pharmacokinetics profile and biodistribution of the drug and liposome carrier following multiple injections were determined. Meanwhile, the antitumor effect of sequential low-dose chemotherapy was tested. To clarify this unexpected phenomenon, the production of polyethylene glycol (PEG)-specific immunoglobulin M (IgM), drug release, and residual complement activity experiments were conducted in serum. Results The first or sequential injections of PEGylated liposomes within a certain dose range induced the rapid clearance of subsequently injected PEGylated liposomal EPI. Of note, the clearance of EPI was two- to three-fold faster than the liposome itself, and a large amount of EPI was released from liposomes in the first 30 minutes in a complement-activation, direct-dependent manner. The therapeutic efficacy of liposomal EPI following 10 days of sequential injections in S180 tumor-bearing mice of 0.75 mg EPI/kg body weight was almost completely abolished between the sixth and tenth day of the sequential injections, even although the subsequently injected doses were doubled. The level of PEG-specific IgM in the blood increased rapidly, with a larger amount of complement being activated while the concentration of EPI in blood and tumor tissue was significantly reduced. Conclusion Our investigation implied that the accelerated blood clearance phenomenon and its accompanying rapid leakage and clearance of drug following sequential low-dose injections may reverse the unique pharmacokinetic–toxicity profile of liposomes which deserved our attention. Therefore, a more reasonable treatment regime should be selected to lessen or even eliminate this phenomenon. PMID:23576868

Multi-point objective-oriented sequential sampling strategy for constrained robust design

NASA Astrophysics Data System (ADS)

Zhu, Ping; Zhang, Siliang; Chen, Wei

2015-03-01

Metamodelling techniques are widely used to approximate system responses of expensive simulation models. In association with the use of metamodels, objective-oriented sequential sampling methods have been demonstrated to be effective in balancing the need for searching an optimal solution versus reducing the metamodelling uncertainty. However, existing infilling criteria are developed for deterministic problems and restricted to one sampling point in one iteration. To exploit the use of multiple samples and identify the true robust solution in fewer iterations, a multi-point objective-oriented sequential sampling strategy is proposed for constrained robust design problems. In this article, earlier development of objective-oriented sequential sampling strategy for unconstrained robust design is first extended to constrained problems. Next, a double-loop multi-point sequential sampling strategy is developed. The proposed methods are validated using two mathematical examples followed by a highly nonlinear automotive crashworthiness design example. The results show that the proposed method can mitigate the effect of both metamodelling uncertainty and design uncertainty, and identify the robust design solution more efficiently than the single-point sequential sampling approach.

Description and effects of sequential behavior practice in teacher education.

PubMed

Sharpe, T; Lounsbery, M; Bahls, V

1997-09-01

This study examined the effects of a sequential behavior feedback protocol on the practice-teaching experiences of undergraduate teacher trainees. The performance competencies of teacher trainees were analyzed using an alternative opportunities for appropriate action measure. Data support the added utility of sequential (Sharpe, 1997a, 1997b) behavior analysis information in systematic observation approaches to teacher education. One field-based undergraduate practicum using sequential behavior (i.e., field systems analysis) principles was monitored. Summarized are the key elements of the (a) classroom instruction provided as a precursor to the practice teaching experience, (b) practice teaching experience, and (c) field systems observation tool used for evaluation and feedback, including multiple-baseline data (N = 4) to support this approach to teacher education. Results point to (a) the strong relationship between sequential behavior feedback and the positive change in four preservice teachers' day-to-day teaching practices in challenging situational contexts, and (b) the relationship between changes in teacher practices and positive changes in the behavioral practices of gymnasium pupils. Sequential behavior feedback was also socially validated by the undergraduate participants and Professional Development School teacher supervisors in the study.

Sequential divergence and the multiplicative origin of community diversity

PubMed Central

Hood, Glen R.; Forbes, Andrew A.; Powell, Thomas H. Q.; Egan, Scott P.; Hamerlinck, Gabriela; Smith, James J.; Feder, Jeffrey L.

2015-01-01

Phenotypic and genetic variation in one species can influence the composition of interacting organisms within communities and across ecosystems. As a result, the divergence of one species may not be an isolated process, as the origin of one taxon could create new niche opportunities for other species to exploit, leading to the genesis of many new taxa in a process termed “sequential divergence.” Here, we test for such a multiplicative effect of sequential divergence in a community of host-specific parasitoid wasps, Diachasma alloeum, Utetes canaliculatus, and Diachasmimorpha mellea (Hymenoptera: Braconidae), that attack Rhagoletis pomonella fruit flies (Diptera: Tephritidae). Flies in the R. pomonella species complex radiated by sympatrically shifting and ecologically adapting to new host plants, the most recent example being the apple-infesting host race of R. pomonella formed via a host plant shift from hawthorn-infesting flies within the last 160 y. Using population genetics, field-based behavioral observations, host fruit odor discrimination assays, and analyses of life history timing, we show that the same host-related ecological selection pressures that differentially adapt and reproductively isolate Rhagoletis to their respective host plants (host-associated differences in the timing of adult eclosion, host fruit odor preference and avoidance behaviors, and mating site fidelity) cascade through the ecosystem and induce host-associated genetic divergence for each of the three members of the parasitoid community. Thus, divergent selection at lower trophic levels can potentially multiplicatively and rapidly amplify biodiversity at higher levels on an ecological time scale, which may sequentially contribute to the rich diversity of life. PMID:26499247

A 2-step penalized regression method for family-based next-generation sequencing association studies.

PubMed

Ding, Xiuhua; Su, Shaoyong; Nandakumar, Kannabiran; Wang, Xiaoling; Fardo, David W

2014-01-01

Large-scale genetic studies are often composed of related participants, and utilizing familial relationships can be cumbersome and computationally challenging. We present an approach to efficiently handle sequencing data from complex pedigrees that incorporates information from rare variants as well as common variants. Our method employs a 2-step procedure that sequentially regresses out correlation from familial relatedness and then uses the resulting phenotypic residuals in a penalized regression framework to test for associations with variants within genetic units. The operating characteristics of this approach are detailed using simulation data based on a large, multigenerational cohort.

The Digital Shoreline Analysis System (DSAS) Version 4.0 - An ArcGIS extension for calculating shoreline change

USGS Publications Warehouse

Thieler, E. Robert; Himmelstoss, Emily A.; Zichichi, Jessica L.; Ergul, Ayhan

2009-01-01

The Digital Shoreline Analysis System (DSAS) version 4.0 is a software extension to ESRI ArcGIS v.9.2 and above that enables a user to calculate shoreline rate-of-change statistics from multiple historic shoreline positions. A user-friendly interface of simple buttons and menus guides the user through the major steps of shoreline change analysis. Components of the extension and user guide include (1) instruction on the proper way to define a reference baseline for measurements, (2) automated and manual generation of measurement transects and metadata based on user-specified parameters, and (3) output of calculated rates of shoreline change and other statistical information. DSAS computes shoreline rates of change using four different methods: (1) endpoint rate, (2) simple linear regression, (3) weighted linear regression, and (4) least median of squares. The standard error, correlation coefficient, and confidence interval are also computed for the simple and weighted linear-regression methods. The results of all rate calculations are output to a table that can be linked to the transect file by a common attribute field. DSAS is intended to facilitate the shoreline change-calculation process and to provide rate-of-change information and the statistical data necessary to establish the reliability of the calculated results. The software is also suitable for any generic application that calculates positional change over time, such as assessing rates of change of glacier limits in sequential aerial photos, river edge boundaries, land-cover changes, and so on.

Sequential circuit design for radiation hardened multiple voltage integrated circuits

DOEpatents

Clark, Lawrence T [Phoenix, AZ; McIver, III, John K.

2009-11-24

The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

Weak Convergence of Bounded Influence Regression Estimates with Applications.

DTIC Science & Technology

1980-04-01

for bounded influence regression M-estimates and apply the results to sequential clinical trials , withI special reference to repeated significance...AUTHOR(s) S. CONTRACT O&GRANT NUIMBER(s) ,’ Raymond J. Carrol avv David/uppert v .. AFOSR-80-0 9. PERFORMING ORGANIZATION NAME AND ADDRESS PRO AM I...THIS PAGE (*%ten [)at& Eke 7") 2 1. Introduction. Our primary concern is the comparison of two treatments in a clinical setting, although our results

A fast and accurate online sequential learning algorithm for feedforward networks.

PubMed

Liang, Nan-Ying; Huang, Guang-Bin; Saratchandran, P; Sundararajan, N

2006-11-01

In this paper, we develop an online sequential learning algorithm for single hidden layer feedforward networks (SLFNs) with additive or radial basis function (RBF) hidden nodes in a unified framework. The algorithm is referred to as online sequential extreme learning machine (OS-ELM) and can learn data one-by-one or chunk-by-chunk (a block of data) with fixed or varying chunk size. The activation functions for additive nodes in OS-ELM can be any bounded nonconstant piecewise continuous functions and the activation functions for RBF nodes can be any integrable piecewise continuous functions. In OS-ELM, the parameters of hidden nodes (the input weights and biases of additive nodes or the centers and impact factors of RBF nodes) are randomly selected and the output weights are analytically determined based on the sequentially arriving data. The algorithm uses the ideas of ELM of Huang et al. developed for batch learning which has been shown to be extremely fast with generalization performance better than other batch training methods. Apart from selecting the number of hidden nodes, no other control parameters have to be manually chosen. Detailed performance comparison of OS-ELM is done with other popular sequential learning algorithms on benchmark problems drawn from the regression, classification and time series prediction areas. The results show that the OS-ELM is faster than the other sequential algorithms and produces better generalization performance.

Development of a multilayered association polymer system for sequential drug delivery

NASA Astrophysics Data System (ADS)

Chinnakavanam Sundararaj, Sharath kumar

As all the physiological processes in our body are controlled by multiple biomolecules, comprehensive treatment of certain disease conditions may be more effectively achieved by administration of more than one type of drug. Thus, the primary objective of this research was to develop a multilayered, polymer-based system for sequential delivery of multiple drugs. This particular device was designed aimed at the treatment of periodontitis, a highly prevalent oral inflammatory disease that affects 90% of the world population. This condition is caused by bacterial biofilm on the teeth, resulting in a chronic inflammatory response that leads to loss of alveolar bone and, ultimately, the tooth. Current treatment methods for periodontitis address specific parts of the disease, with no individual treatment serving as a complete therapy. The polymers used for the fabrication of this multilayered device consists of cellulose acetate phthalate (CAP) complexed with Pluronic F-127 (P). After evaluating morphology of the resulting CAPP system, in vitro release of small molecule drugs and a model protein was studied from both single and multilayered devices. Drug release from single-layered CAPP films followed zero-order kinetics related to surface erosion property of the association polymer. Release studies from multilayered CAPP devices showed the possibility of achieving intermittent release of one type of drug as well as sequential release of more than one type of drug. Mathematical modeling accurately predicted the release profiles for both single layer and multilayered devices. After the initial characterization of the CAPP system, the device was specifically modified to achieve sequential release of drugs aimed at the treatment of periodontitis. The four types of drugs used were metronidazole, ketoprofen, doxycycline, and simvastatin to eliminate infection, inhibit inflammation, prevent tissue destruction, and aid bone regeneration, respectively. To obtain different erosion times and achieve appropriate release profiles specific to the disease condition, the device was modified by increasing the number of layers or by inclusion of a slower eroding polymer layer. In all the cases, the device was able to release the four different drugs in the designed temporal sequence. Analysis of antibiotic and antiinflammatory bioactivity showed that drugs released from the devices retained 100% bioactivity. Following extensive studies on the in vitro sequential drug release from these devices, the in vivo drug release profiles were investigated. The CAPP devices with different release rates and dosage formulations were implanted in a rat calvarial onlay model, and the in vivo drug release and erosion was compared with in vitro results. In vivo studies showed sequential release of drugs comparable to those measured in vitro, with some difference in drug release rates observed. The present CAPP association polymer-based multilayer devices can be used for localized, sequential delivery of multiple drugs for the possible treatment of complex disease conditions, and perhaps for tissue engineering applications, that require delivery of more than one type of biomolecule. KEYWORDS: Multiple drug delivery, Periodontitis, Cellulose acetate phthalate, Pluronic F-127, Sequential drug release, in vitro drug release, in vivo drug release.

Racial/Ethnic Disparities in Primary Care Quality Among Type 2 Diabetes Patients, Medical Expenditure Panel Survey, 2012.

PubMed

Hu, Ruwei; Shi, Leiyu; Liang, Hailun; Haile, Geraldine Pierre; Lee, De-Chih

2016-08-04

Racial and ethnic disparities exist in diabetes prevalence, access to diabetes care, diabetes-related complications and mortality rates, and the quality of diabetes care among Americans. We explored racial and ethnic disparities in primary care quality among Americans with type 2 diabetes. We analyzed data on adults with type 2 diabetes derived from the household component of the 2012 Medical Expenditure Panel Survey. Multiple regression and multivariate logistic regressions were used to examine the association between race/ethnicity and primary care attributes related to first contact, longitudinality, comprehensiveness, and coordination, and clusters of confounding factors were added sequentially. Preliminary findings indicated differences in primary care quality between racial/ethnic minorities and whites across measures of first contact, longitudinality, comprehensiveness, and coordination. After controlling for confounding factors, these differences were no longer apparent; all racial/ethnic categories showed similar rates of primary care quality according to the 4 primary care domains of interest in the study. Results indicate equitable primary care quality for type 2 diabetes patients across 4 key domains of primary care after controlling for socioeconomic characteristics. Additional research is necessary to support these findings, particularly when considering smaller racial/ethnic groups and investigating outcomes related to diabetes.

MBS Measurement Tool for Swallow Impairment—MBSImp: Establishing a Standard

PubMed Central

Martin-Harris, Bonnie; Brodsky, Martin B.; Michel, Yvonne; Castell, Donald O.; Schleicher, Melanie; Sandidge, John; Maxwell, Rebekah; Blair, Julie

2014-01-01

The aim of this study was to test reliability, content, construct, and external validity of a new modified barium swallowing study (MBSS) tool (MBSImp) that is used to quantify swallowing impairment. Multiple regression, confirmatory factor, and correlation analyses were used to analyze 300 in- and outpatients with heterogeneous medical and surgical diagnoses who were sequentially referred for MBS exams at a university medical center and private tertiary care community hospital. Main outcome measures were the MBSImp and index scores of aspiration, health status, and quality of life. Inter- and intrarater concordance were 80% or greater for blinded scoring of MBSSs. Regression analysis revealed contributions of eight of nine swallow types to impressions of overall swallowing impairment (p ≤ 0.05). Factor analysis revealed 13 significant components (loadings ≥ 0.5) that formed two impairment groupings (oral and pharyngeal). Significant correlations were found between Oral and Pharyngeal Impairment scores and Penetration-Aspiration Scale scores, and indexes of intake status, nutrition, health status, and quality of life. The MBSImp demonstrated clinical practicality, favorable inter- and intrarater reliability following standardized training, content, and external validity. This study reflects potential for establishment of a new standard for quantification and comparison of oropharyngeal swallowing impairment across patient diagnoses as measured on MBSS. PMID:18855050

It's Deja Vu All over Again: Using Multiple-Spell Discrete-Time Survival Analysis.

ERIC Educational Resources Information Center

Willett, John B.; Singer, Judith D.

1995-01-01

The multiple-spell discrete-time survival analysis method is introduced and illustrated using longitudinal data on exit from and reentry into the teaching profession. The method is applicable to many educational problems involving the sequential occurrence of disparate events or episodes. (SLD)

Design and protocol of a randomized multiple behavior change trial: Make Better Choices 2 (MBC2).

PubMed

Pellegrini, Christine A; Steglitz, Jeremy; Johnston, Winter; Warnick, Jennifer; Adams, Tiara; McFadden, H G; Siddique, Juned; Hedeker, Donald; Spring, Bonnie

2015-03-01

Suboptimal diet and inactive lifestyle are among the most prevalent preventable causes of premature death. Interventions that target multiple behaviors are potentially efficient; however the optimal way to initiate and maintain multiple health behavior changes is unknown. The Make Better Choices 2 (MBC2) trial aims to examine whether sustained healthful diet and activity change are best achieved by targeting diet and activity behaviors simultaneously or sequentially. Study design approximately 250 inactive adults with poor quality diet will be randomized to 3 conditions examining the best way to prescribe healthy diet and activity change. The 3 intervention conditions prescribe: 1) an increase in fruit and vegetable consumption (F/V+), decrease in sedentary leisure screen time (Sed-), and increase in physical activity (PA+) simultaneously (Simultaneous); 2) F/V+ and Sed- first, and then sequentially add PA+ (Sequential); or 3) Stress Management Control that addresses stress, relaxation, and sleep. All participants will receive a smartphone application to self-monitor behaviors and regular coaching calls to help facilitate behavior change during the 9 month intervention. Healthy lifestyle change in fruit/vegetable and saturated fat intakes, sedentary leisure screen time, and physical activity will be assessed at 3, 6, and 9 months. MBC2 is a randomized m-Health intervention examining methods to maximize initiation and maintenance of multiple healthful behavior changes. Results from this trial will provide insight about an optimal technology supported approach to promote improvement in diet and physical activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Sequential multiple-assignment randomized trial design of neurobehavioral treatment for patients with metastatic malignant melanoma undergoing high-dose interferon-alpha therapy.

PubMed

Auyeung, S Freda; Long, Qi; Royster, Erica Bruce; Murthy, Smitha; McNutt, Marcia D; Lawson, David; Miller, Andrew; Manatunga, Amita; Musselman, Dominique L

2009-10-01

Interferon-alpha therapy, which is used to treat metastatic malignant melanoma, can cause patients to develop two distinct neurobehavioral symptom complexes: a mood syndrome and a neurovegetative syndrome. Interferon-alpha effects on serotonin metabolism appear to contribute to the mood and anxiety syndrome, while the neurovegetative syndrome appears to be related to interferon-alpha effects on dopamine. Our goal is to propose a design for utilizing a sequential, multiple assignment, randomized trial design for patients with malignant melanoma to test the relative efficacy of drugs that target serotonin versus dopamine metabolism during 4 weeks of intravenous, then 8 weeks of subcutaneous, interferon-alpha therapy. Patients will be offered participation in a double-blinded, randomized, controlled, 14-week trial involving two treatment phases. During the first month of intravenous interferon-alpha therapy, we will test the hypotheses that escitalopram will be more effective in reducing depressed mood, anxiety, and irritability, whereas methylphenidate will be more effective in diminishing interferon-alpha-induced neurovegetative symptoms, such as fatigue and psychomotor slowing. During the next 8 weeks of subcutaneous interferon therapy, participants whose symptoms do not improve significantly will be randomized to the alternate agent alone versus escitalopram and methylphenidate together. We present a prototype for a single-center, sequential, multiple assignment, randomized trial, which seeks to determine the efficacy of sequenced and targeted treatment for the two distinct symptom complexes suffered by patients treated with interferon-alpha. Because we cannot completely control for external factors, a relevant question is whether or not 'short-term' neuropsychiatric interventions can increase the number of interferon-alpha doses tolerated and improve long-term survival. This sequential, multiple assignment, randomized trial proposes a framework for developing optimal treatment strategies; however, additional studies are needed to determine the best strategy for treating or preventing neurobehavioral symptoms induced by the immunotherapy interferon-alpha.

Protocol Analysis as a Tool in Function and Task Analysis

DTIC Science & Technology

1999-10-01

Autocontingency The use of log-linear and logistic regression methods to analyse sequential data seems appealing , and is strongly advocated by...collection and analysis of observational data. Behavior Research Methods, Instruments, and Computers, 23(3), 415-429. Patrick, J. D. (1991). Snob : A

Timed sequential chemotherapy of cytoxan-refractory multiple myeloma with cytoxan and adriamycin based on induced tumor proliferation.

PubMed

Karp, J E; Humphrey, R L; Burke, P J

1981-03-01

Malignant plasma cell proliferation and induced humoral stimulatory activity (HSA) occur in vivo at a predictable time following drug administration. Sequential sera from 11 patients with poor-risk multiple myeloma (MM) undergoing treatment with Cytoxan (CY) 2400 mq/sq m were assayed for their in vitro effects on malignant bone marrow plasma cell tritiated thymidine (3HTdR) incorporation. Peak HSA was detected day 9 following CY. Sequential changes in marrow malignant plasma cell 3HTdR-labeling indices (LI) paralleled changes in serum activity, with peak LI occurring at the time of peak HS. An in vitro model of chemotherapy demonstrated that malignant plasma cell proliferation was enhanced by HSA, as determined by 3HTdR incorporation assay, 3HTdR LI, and tumor cells counts, and that stimulated plasma cells were more sensitive to cytotoxic effects of adriamycin (ADR) than were cells cultured in autologous pretreatment serum. Based on these studies, we designed a clinical trial to treat 12 CY-refractory poor-risk patients with MM in which ADR (60 mg/sq m) was administered at the time of peak HSA and residual tumor cell LI (day 9) following initial CY, 2400 mg/m (CY1ADR9). Eight of 12 (67%) responded to timed sequential chemotherapy with a greater than 50% decrement in monoclonal protein marker and a median survival projected to be greater than 8 mo duration (range 4-21+ mo). These clinical results using timed sequential CY1ADR9 compare favorably with results obtained using ADR in nonsequential chemotherapeutic regimens.

Simultaneous or Early Sequential Rupture of Multiple Intracranial Aneurysms: A Rare and Insufficiently Understood Entity.

PubMed

Hou, Kun; Zhao, Jinchuan; Zhang, Yang; Zhu, Xiaobo; Zhao, Yan; Li, Guichen

2016-05-01

Simultaneous or early sequential rupture of multiple intracranial aneurysms (MIAs) is encountered rarely, with no more than 10 cases having been reported. As a result of its rarity, there are a lot of questions concerning this entity need to be answered. A 67-year-old woman was admitted to the First Hospital of Jilin University (Eastern Division) from a local hospital after a sudden onset of severe headache, nausea, and vomiting. Head computed tomography (CT) at the local hospital revealed diffuse subarachnoid hemorrhage (SAH) that was concentrated predominately in the suprasellar cistern and interhemispheric fissure. During her transfer to our hospital, she experienced another episode of sudden headache. CT on admission to our hospital revealed that the SAH was increased with 2 isolated hematomas both in the interhemispheric fissure and the left paramedian frontal lobe. Further CT angiography and intraoperative findings were in favor of early sequential rupture of 2 intracranial aneurysms. To further elucidate the characteristics, mechanism, management, and prognosis of this specific entity, we conducted a comprehensive review of the literature. The mechanism of simultaneous or early sequential rupture of MIAs is still obscure. Transient elevation of blood pressure might play a role in the process, and preventing the sudden elevation of blood pressure might be beneficial for patients with aneurysmal SAH and MIAs. The management of simultaneously or early sequentially ruptured aneurysms is more complex for its difficulty in responsible aneurysm determination, urgency in treatment, toughness in intraoperative manipulation and poorness in prognosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Sequential Prediction of Literacy Achievement for Specific Learning Disabilities Contrasting in Impaired Levels of Language in Grades 4 to 9

PubMed Central

Sanders, Elizabeth A.; Berninger, Virginia W.; Abbott, Robert D.

2017-01-01

Sequential regression was used to evaluate whether language-related working memory components uniquely predict reading and writing achievement beyond cognitive-linguistic translation for students in grades 4–9 (N=103) with specific learning disabilities (SLDs) in subword handwriting (dysgraphia, n=25), word reading and spelling (dyslexia, n=60), or oral and written language (OWL LD, n=18). That is, SLDs are defined on basis of cascading level of language impairment (subword, word, and syntax/text). A 5-block regression model sequentially predicted literacy achievement from cognitive-linguistic translation (Block 1); working memory components for word form coding (Block 2), phonological and orthographic loops (Block 3), and supervisory focused or switching attention (Block4); and SLD groups (Block 5). Results showed that cognitive-linguistic translation explained an average of 27% and 15% of the variance in reading and writing achievement, respectively, but working memory components explained an additional 39% and 27% variance. Orthographic word form coding uniquely predicted nearly every measure, whereas attention switching only uniquely predicted reading. Finally, differences in reading and writing persisted between dyslexia and dysgraphia, with dysgraphia higher, even after controlling for Block 1 to 4 predictors. Differences in literacy achievement between students with dyslexia and OWL LD were largely explained by the Block 1 predictors. Applications to identifying and teaching students with these SLDs are discussed. PMID:28199175

Outcome of heart-lung and bilateral sequential lung transplantation for cystic fibrosis: a UK national study.

PubMed

Ganesh, J S; Rogers, C A; Bonser, R S; Banner, N R

2005-06-01

Cystic fibrosis (CF) patients requiring transplantation for respiratory failure may undergo either heart-lung (HLT) or bilateral sequential lung (BSLT) transplantation. The choice of operation varies between surgeons, centres and countries. The current authors investigated whether operation type influenced outcome in adult CF patients transplanted in the UK between July 1995 and June 2002. Propensity scores for receipt of BSLT versus HLT were derived using logistic regression. Cox regression was used to compare survival. In total, 88 BSLTs and 93 HLTs were identified. Patient characteristics were similar overall, but HLT recipients were more likely to be on long-term oxygen therapy and to have had prior resuscitation. There were 72 deaths (29 BSLT and 43 HLT) within 4 yrs. There was a trend towards higher unadjusted survival following BSLT, but, after adjustment, no difference was found (hazard ratio = 0.77; 95% confidence interval 0.29-2.06). Time to the first rejection episode and infection rates were also similar. A total of 82% of hearts from HLT recipients were used as domino heart transplants. In conclusion, after adjusting for comorbidity, donor factors and ischaemia time, it was found that heart-lung and bilateral sequential lung transplantation achieved a similar outcome. The use of domino heart transplantation ameliorated the impact of heart-lung transplantation on total organ availability.

Conjoin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sjaardema, Gregory

2010-08-06

Conjoin is a code for joining sequentially in time multiple exodusII database files. It is used to create a single results or restart file from multiple results or restart files which typically arise as the result of multiple restarted analyses. The resulting output file will be the union of the input files with a status variable indicating the status of each element at the various time planes.Combining multiple exodusII files arising from a restarted analysis or combining multiple exodusII files arising from a finite element analysis with dynamic topology changes.

General solutions to multiple testing problems. Translation of "Sonnemann, E. (1982). Allgemeine Lösungen multipler Test probleme. EDV in Medizin und Biologie 13(4), 120-128".

PubMed

Sonnemann, Eckart

2008-10-01

The introduction of sequentially rejective multiple test procedures (Einot and Gabriel, 1975; Naik, 1975; Holm, 1977; Holm, 1979) has caused considerable progress in the theory of multiple comparisons. Emphasizing the closure of multiple tests we give a survey of the general theory and its recent results in applications. Some new applications are given including a discussion of the connection with the theory of confidence regions.

The PMHT: solutions for some of its problems

NASA Astrophysics Data System (ADS)

Wieneke, Monika; Koch, Wolfgang

2007-09-01

Tracking multiple targets in a cluttered environment is a challenging task. Probabilistic Multiple Hypothesis Tracking (PMHT) is an efficient approach for dealing with it. Essentially PMHT is based on the method of Expectation-Maximization for handling with association conflicts. Linearity in the number of targets and measurements is the main motivation for a further development and extension of this methodology. Unfortunately, compared with the Probabilistic Data Association Filter (PDAF), PMHT has not yet shown its superiority in terms of track-lost statistics. Furthermore, the problem of track extraction and deletion is apparently not yet satisfactorily solved within this framework. Four properties of PMHT are responsible for its problems in track maintenance: Non-Adaptivity, Hospitality, Narcissism and Local Maxima. 1, 2 In this work we present a solution for each of them and derive an improved PMHT by integrating the solutions into the PMHT formalism. The new PMHT is evaluated by Monte-Carlo simulations. A sequential Likelihood-Ratio (LR) test for track extraction has been developed and already integrated into the framework of traditional Bayesian Multiple Hypothesis Tracking. 3 As a multi-scan approach, also the PMHT methodology has the potential for track extraction. In this paper an analogous integration of a sequential LR test into the PMHT framework is proposed. We present an LR formula for track extraction and deletion using the PMHT update formulae. As PMHT provides all required ingredients for a sequential LR calculation, the LR is thus a by-product of the PMHT iteration process. Therefore the resulting update formula for the sequential LR test affords the development of Track-Before-Detect algorithms for PMHT. The approach is illustrated by a simple example.

Actively learning human gaze shifting paths for semantics-aware photo cropping.

PubMed

Zhang, Luming; Gao, Yue; Ji, Rongrong; Xia, Yingjie; Dai, Qionghai; Li, Xuelong

2014-05-01

Photo cropping is a widely used tool in printing industry, photography, and cinematography. Conventional cropping models suffer from the following three challenges. First, the deemphasized role of semantic contents that are many times more important than low-level features in photo aesthetics. Second, the absence of a sequential ordering in the existing models. In contrast, humans look at semantically important regions sequentially when viewing a photo. Third, the difficulty of leveraging inputs from multiple users. Experience from multiple users is particularly critical in cropping as photo assessment is quite a subjective task. To address these challenges, this paper proposes semantics-aware photo cropping, which crops a photo by simulating the process of humans sequentially perceiving semantically important regions of a photo. We first project the local features (graphlets in this paper) onto the semantic space, which is constructed based on the category information of the training photos. An efficient learning algorithm is then derived to sequentially select semantically representative graphlets of a photo, and the selecting process can be interpreted by a path, which simulates humans actively perceiving semantics in a photo. Furthermore, we learn a prior distribution of such active graphlet paths from training photos that are marked as aesthetically pleasing by multiple users. The learned priors enforce the corresponding active graphlet path of a test photo to be maximally similar to those from the training photos. Experimental results show that: 1) the active graphlet path accurately predicts human gaze shifting, and thus is more indicative for photo aesthetics than conventional saliency maps and 2) the cropped photos produced by our approach outperform its competitors in both qualitative and quantitative comparisons.

Application and analysis of retroperitoneal laparoscopic partial nephrectomy with sequential segmental renal artery clamping for patients with multiple renal tumor: initial experience.

PubMed

Zhu, Jundong; Jiang, Fan; Li, Pu; Shao, Pengfei; Liang, Chao; Xu, Aiming; Miao, Chenkui; Qin, Chao; Wang, Zengjun; Yin, Changjun

2017-09-11

To explore the feasibility and safety of retroperitoneal laparoscopic partial nephrectomy with sequential segmental renal artery clamping for the patients with multiple renal tumor of who have solitary kidney or contralateral kidney insufficiency. Nine patients who have undergone retroperitoneal laparoscopic partial nephrectomy with sequential segmental renal artery clamping between October 2010 and January 2017 were retrospectively analyzed. Clinical materials and parameters during and after the operation were summarized. Nineteen tumors were resected in nine patients and the operations were all successful. The operation time ranged from 100 to 180 min (125 min); clamping time of segmental renal artery was 10 ~ 30 min (23 min); the amount of blood loss during the operation was 120 ~ 330 ml (190 ml); hospital stay after the operation is 3 ~ 6d (5d). There was no complication during the perioperative period, and the pathology diagnosis after the surgery showed that there were 13 renal clear cell carcinomas, two papillary carcinoma and four perivascular epithelioid cell tumors with negative margins from the 19 tumors. All patients were followed up for 3 ~ 60 months, and no local recurrence or metastasis was detected. At 3-month post-operation follow-up, the mean serum creatinine was 148.6 ± 28.1 μmol/L (p = 0.107), an increase of 3.0 μmol/L from preoperative baseline. For the patients with multiple renal tumors and solitary kidney or contralateral kidney insufficiency, retroperitoneal laparoscopic partial nephrectomy with sequential segmental renal artery clamping was feasible and safe, which minimized the warm ischemia injury to the kidney and preserved the renal function effectively.

An extended sequential goodness-of-fit multiple testing method for discrete data.

PubMed

Castro-Conde, Irene; Döhler, Sebastian; de Uña-Álvarez, Jacobo

2017-10-01

The sequential goodness-of-fit (SGoF) multiple testing method has recently been proposed as an alternative to the familywise error rate- and the false discovery rate-controlling procedures in high-dimensional problems. For discrete data, the SGoF method may be very conservative. In this paper, we introduce an alternative SGoF-type procedure that takes into account the discreteness of the test statistics. Like the original SGoF, our new method provides weak control of the false discovery rate/familywise error rate but attains false discovery rate levels closer to the desired nominal level, and thus it is more powerful. We study the performance of this method in a simulation study and illustrate its application to a real pharmacovigilance data set.

Multiple ionization of neon by soft x-rays at ultrahigh intensity

NASA Astrophysics Data System (ADS)

Guichard, R.; Richter, M.; Rost, J.-M.; Saalmann, U.; Sorokin, A. A.; Tiedtke, K.

2013-08-01

At the free-electron laser FLASH, multiple ionization of neon atoms was quantitatively investigated at photon energies of 93.0 and 90.5 eV. For ion charge states up to 6+, we compare the respective absolute photoionization yields with results from a minimal model and an elaborate description including standard sequential and direct photoionization channels. Both approaches are based on rate equations and take into account a Gaussian spatial intensity distribution of the laser beam. From the comparison we conclude that photoionization up to a charge of 5+ can be described by the minimal model which we interpret as sequential photoionization assisted by electron shake-up processes. For higher charges, the experimental ionization yields systematically exceed the elaborate rate-based prediction.

Uncertainty assessment of PM2.5 contamination mapping using spatiotemporal sequential indicator simulations and multi-temporal monitoring data.

PubMed

Yang, Yong; Christakos, George; Huang, Wei; Lin, Chengda; Fu, Peihong; Mei, Yang

2016-04-12

Because of the rapid economic growth in China, many regions are subjected to severe particulate matter pollution. Thus, improving the methods of determining the spatiotemporal distribution and uncertainty of air pollution can provide considerable benefits when developing risk assessments and environmental policies. The uncertainty assessment methods currently in use include the sequential indicator simulation (SIS) and indicator kriging techniques. However, these methods cannot be employed to assess multi-temporal data. In this work, a spatiotemporal sequential indicator simulation (STSIS) based on a non-separable spatiotemporal semivariogram model was used to assimilate multi-temporal data in the mapping and uncertainty assessment of PM2.5 distributions in a contaminated atmosphere. PM2.5 concentrations recorded throughout 2014 in Shandong Province, China were used as the experimental dataset. Based on the number of STSIS procedures, we assessed various types of mapping uncertainties, including single-location uncertainties over one day and multiple days and multi-location uncertainties over one day and multiple days. A comparison of the STSIS technique with the SIS technique indicate that a better performance was obtained with the STSIS method.

Uncertainty assessment of PM2.5 contamination mapping using spatiotemporal sequential indicator simulations and multi-temporal monitoring data

NASA Astrophysics Data System (ADS)

Yang, Yong; Christakos, George; Huang, Wei; Lin, Chengda; Fu, Peihong; Mei, Yang

2016-04-01

Because of the rapid economic growth in China, many regions are subjected to severe particulate matter pollution. Thus, improving the methods of determining the spatiotemporal distribution and uncertainty of air pollution can provide considerable benefits when developing risk assessments and environmental policies. The uncertainty assessment methods currently in use include the sequential indicator simulation (SIS) and indicator kriging techniques. However, these methods cannot be employed to assess multi-temporal data. In this work, a spatiotemporal sequential indicator simulation (STSIS) based on a non-separable spatiotemporal semivariogram model was used to assimilate multi-temporal data in the mapping and uncertainty assessment of PM2.5 distributions in a contaminated atmosphere. PM2.5 concentrations recorded throughout 2014 in Shandong Province, China were used as the experimental dataset. Based on the number of STSIS procedures, we assessed various types of mapping uncertainties, including single-location uncertainties over one day and multiple days and multi-location uncertainties over one day and multiple days. A comparison of the STSIS technique with the SIS technique indicate that a better performance was obtained with the STSIS method.

Heuristic and optimal policy computations in the human brain during sequential decision-making.

PubMed

Korn, Christoph W; Bach, Dominik R

2018-01-23

Optimal decisions across extended time horizons require value calculations over multiple probabilistic future states. Humans may circumvent such complex computations by resorting to easy-to-compute heuristics that approximate optimal solutions. To probe the potential interplay between heuristic and optimal computations, we develop a novel sequential decision-making task, framed as virtual foraging in which participants have to avoid virtual starvation. Rewards depend only on final outcomes over five-trial blocks, necessitating planning over five sequential decisions and probabilistic outcomes. Here, we report model comparisons demonstrating that participants primarily rely on the best available heuristic but also use the normatively optimal policy. FMRI signals in medial prefrontal cortex (MPFC) relate to heuristic and optimal policies and associated choice uncertainties. Crucially, reaction times and dorsal MPFC activity scale with discrepancies between heuristic and optimal policies. Thus, sequential decision-making in humans may emerge from integration between heuristic and optimal policies, implemented by controllers in MPFC.

Protective resources and perceptions of stress in a multi-ethnic sample of school-age children.

PubMed

Taxis, J Carole; Rew, Lynn; Jackson, Kate; Kouzekanani, Kamiar

2004-01-01

To investigate the relationship among protective resources of social connectedness, coping skills, and the perception of stress in 613 Hispanic and White school-aged children. A secondary analysis of data, part of a longitudinal cohort-sequential study designed to investigate health-risk behaviors in school-age children. Data were collected by computer-assisted self-interviewing from a non-probability sample of 8-12-year-olds in three independent school districts. Hierarchical multiple regression analysis indicated that social connectedness and the frequency of coping strategies used accounted for 18.8% of the variation in stress. "Feeling sick" was the primary stressor of the participants, while the two most frequently endorsed coping strategies were "watch TV or listen to music" and "draw, write, or read something." The findings are significant because nurses working with children are in a strategic position to assess risk factors and protective resources related to stress and intervene in a timely manner to assist children and families develop resiliency.

Biomass modeling of four water intensiveleading world crops using hyperspectral narrowbands in support of HyspIRI Mission

USGS Publications Warehouse

Marshall, Michael T.; Thenkabail, Prasad S.

2014-01-01

New satellite missions are expected to record high spectral resolution information globally and consistently for the first time, so it is important to identify modeling techniques that take advantage of these new data. In this paper, we estimate biomass for four major crops using ground-based hyperspectral narrowbands. The spectra and their derivatives are evaluated using three modeling techniques: two-band hyperspectral vegetation indices (HVIs), multiple band-HVIs (MB-HVIs) developed from Sequential Search Methods (SSM), and MB-HVIs developed from Principal Component Regression. Overall, the two-band HVIs and MB-HVIs developed from SSMs using first derivative transformed spectra in the visible blue and green and NIR explained more biomass variability and had lower error than the other approaches or transformations; however a better search criterion needs to be developed in order to reflect the true ability of the two-band HVI approach. Short-Wave Infrared 1 (1000 to 1700 nm) proved less effective, but still important in the final models.

Correlation-study about the ambient dose rate and the weather conditions

NASA Astrophysics Data System (ADS)

Furuya, Masato; Hatano, Yuko; Aoyama, Tomoo; Igarashi, Yasuhito; Kita, Kazuyuki; Ishizuka, Masahide

2016-04-01

The long-term radiation risks are believed to be heavily affected by the resuspension process. We therefore focus on the surface-atmosphere exchange process of released radioactive materials in this study. Radioactive materials were deposited on the soil and float in the air, and such complicated process are influenced by the weather conditions deeply. We need to reveal the correlation between the weather conditions and the ambient dose rate. In this study, we study the correlation between the weather conditions and the ambient dose rate with the correction of the decrease due to the radioactive decay. We found that there is a negative correlation between the ambient dose rate and the soil water content by the correlation coefficient. Using this result, we reconstruct the ambient dose rate from the weather conditions by the multiple regression analysis and found that the reconstructed data agree with the observation very well. Using Kalman filter, which can be sequentially updates the state estimate, we obtained such a good agreement.

A Technique of Fuzzy C-Mean in Multiple Linear Regression Model toward Paddy Yield

NASA Astrophysics Data System (ADS)

Syazwan Wahab, Nur; Saifullah Rusiman, Mohd; Mohamad, Mahathir; Amira Azmi, Nur; Che Him, Norziha; Ghazali Kamardan, M.; Ali, Maselan

2018-04-01

In this paper, we propose a hybrid model which is a combination of multiple linear regression model and fuzzy c-means method. This research involved a relationship between 20 variates of the top soil that are analyzed prior to planting of paddy yields at standard fertilizer rates. Data used were from the multi-location trials for rice carried out by MARDI at major paddy granary in Peninsular Malaysia during the period from 2009 to 2012. Missing observations were estimated using mean estimation techniques. The data were analyzed using multiple linear regression model and a combination of multiple linear regression model and fuzzy c-means method. Analysis of normality and multicollinearity indicate that the data is normally scattered without multicollinearity among independent variables. Analysis of fuzzy c-means cluster the yield of paddy into two clusters before the multiple linear regression model can be used. The comparison between two method indicate that the hybrid of multiple linear regression model and fuzzy c-means method outperform the multiple linear regression model with lower value of mean square error.

The impact of days off between cases on perioperative outcomes for robotic-assisted laparoscopic prostatectomy.

PubMed

Pearce, Shane M; Pariser, Joseph J; Patel, Sanjay G; Anderson, Blake B; Eggener, Scott E; Zagaja, Gregory P

2016-02-01

To examine the effect of days off between cases on perioperative outcomes for robotic-assisted laparoscopic prostatectomy (RALP). We analyzed a single-surgeon series of 2036 RALP cases between 2003 and 2014. Days between cases (DBC) was calculated as the number of days elapsed since the surgeon's previous RALP with the second start cases assigned 0 DBC. Surgeon experience was assessed by dividing sequential case experience into cases 0-99, cases 100-249, cases 250-999, and cases 1000+ based on previously reported learning curve data for RALP. Outcomes included estimated blood loss (EBL), operative time (OT), and positive surgical margins (PSMs). Multiple linear regression was used to assess the impact of the DBC and surgeon experience on EBL, OT, and PSM, while controlling for patient characteristics, surgical technique, and pathologic variables. Overall median DBC was 1 day (0-3) and declined with increasing surgeon case experience. Multiple linear regression demonstrated that each additional DBC was independently associated with increased EBL [β = 3.7, 95% CI (1.3-6.2), p < 0.01] and OT [β = 2.3 (1.4-3.2), p < 0.01], but was not associated with rate of PSM [β = 0.004 (-0.003-0.010), p = 0.2]. Increased experience was also associated with reductions in EBL and OT (p < 0.01). Surgeon experience of 1000+ cases was associated with a 10% reduction in PSM rate (p = 0.03) compared to cases 0-99. In a large single-surgeon RALP series, DBC was associated with increased blood loss and operative time, but not associated with positive surgical margins, when controlling for surgeon experience.

Resilience moderates the risk of depression and anxiety symptoms on suicidal ideation in patients with depression and/or anxiety disorders.

PubMed

Min, Jung-Ah; Lee, Chang-Uk; Chae, Jeong-Ho

2015-01-01

Few studies have investigated the role of protective factors for suicidal ideation, which include resilience and social support among psychiatric patients with depression and/or anxiety disorders who are at increased risk of suicide. Demographic data, history of childhood maltreatment, and levels of depression, anxiety, problematic alcohol use, resilience, perceived social support, and current suicidal ideation were collected from a total of 436 patients diagnosed with depression and/or anxiety disorders. Hierarchical multiple logistic regression analyses were used to identify the independent and interaction effects of potentially influencing factors. Moderate-severe suicidal ideation was reported in 24.5% of our sample. After controlling for relevant covariates, history of emotional neglect and sexual abuse, low resilience, and high depression and anxiety symptoms were sequentially included in the model. In the final model, high depression (adjusted odds ratio (OR)=9.33, confidence interval (CI) 3.99-21.77) and anxiety (adjusted OR=2.62, CI=1.24-5.53) were independently associated with moderate-severe suicidal ideation among risk factors whereas resilience was not. In the multiple logistic regression model that examined interaction effects between risk and protective factors, the interactions between resilience and depression (p<.001) and between resilience and anxiety were significant (p=.021). A higher level of resilience was protective against moderate-severe suicide ideation among those with higher levels of depression or anxiety symptoms. Our results indicate that resilience potentially moderates the risk of depression and anxiety symptoms on suicidal ideation in patients with depression and/or anxiety disorders. Assessment of resilience and intervention focused on resilience enhancement is suggested for suicide prevention. Copyright © 2014 Elsevier Inc. All rights reserved.

The association between hyperoxia and patient outcomes after cardiac arrest: Analysis of a high-resolution database

PubMed Central

Elmer, Jonathan; Scutella, Michael; Pullalarevu, Raghevesh; Wang, Bo; Vaghasia, Nishit; Trzeciak, Stephen; Rosario-Rivera, Bedda L.; Guyette, Francis X.; Rittenberger, Jon C.; Dezfulian, Cameron

2014-01-01

Purpose Previous observational studies have inconsistently associated early hyperoxia with worse outcomes after cardiac arrest and have methodological limitations. We tested this association using a high-resolution database controlling for multiple disease-specific markers of severity of illness and care processes. Methods This was a retrospective analysis of a single-center, prospective registry of consecutive cardiac arrest patients. We included patients who survived and were mechanically ventilated ≥24h after arrest. Our main exposure was arterial oxygen tension (PaO2), which we categorized hourly for 24 hours as severe hyperoxia (>300mmHg), moderate or probable hyperoxia (101-299mmHg), normoxia (60-100mmHg) or hypoxia (<60mmHg). We controlled for Utstein-style covariates, markers of disease severity and markers of care responsiveness. We performed unadjusted and multiple logistic regression to test the association between oxygen exposure and survival to discharge, and used ordered logistic regression to test the association of oxygen exposure with neurological outcome and Sequential Organ Failure Assessment (SOFA) score at 24h. Results Of 184 patients, 36% were exposed to severe hyperoxia and overall mortality was 54%. Severe hyperoxia, but not moderate or probable hyperoxia, was associated with decreased survival in both unadjusted and adjusted analysis (adjusted odds ratio (OR) for survival 0.83 per hour exposure, P=0.04). Moderate or probable hyperoxia was not associated with survival but was associated with improved SOFA score 24h (OR 0.92, P<0.01). Conclusion Severe hyperoxia was independently associated with decreased survival to hospital discharge. Moderate or probable hyperoxia was not associated with decreased survival and was associated with improved organ function at 24h. PMID:25472570

Spatial Representation in Blind Children. 3: Effects of Individual Differences.

ERIC Educational Resources Information Center

Fletcher, Janet F.

1981-01-01

Data from a study of spatial representation in blind children were subjected to two stepwise regression analyses to determine the relationships between several subject related variables and responses to "map" (cognitive map) and "route" (sequential memory) questions about the position of furniture in a recently explored room. (Author/SBH)

Factors Contributing to the Upward Transfer of Baccalaureate Aspirants Beginning at Community Colleges

ERIC Educational Resources Information Center

Wang, Xueli

2012-01-01

This study examined factors associated with the upward transfer of baccalaureate aspirants beginning at community colleges. Based on data from the National Education Longitudinal Study of 1988 and the Postsecondary Education Transcript Study, a sequential logistic regression analysis was conducted to predict bachelor's degree-seeking community…

Clinical Utility of Cancellation on the WISC-IV

ERIC Educational Resources Information Center

Zhu, Jianjun; Chen, Hsinyi

2013-01-01

This study examined empirical evidence for clinical utility of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) cancellation subtest by comparing data from 597 clinical and 597 matched control children. The results of dependent t and sequential logistic regression analyses demonstrated that (a) children with intellectual…

Effects of Estimation Bias on Multiple-Category Classification with an IRT-Based Adaptive Classification Procedure

ERIC Educational Resources Information Center

Yang, Xiangdong; Poggio, John C.; Glasnapp, Douglas R.

2006-01-01

The effects of five ability estimators, that is, maximum likelihood estimator, weighted likelihood estimator, maximum a posteriori, expected a posteriori, and Owen's sequential estimator, on the performances of the item response theory-based adaptive classification procedure on multiple categories were studied via simulations. The following…

A sampling and classification item selection approach with content balancing.

PubMed

Chen, Pei-Hua

2015-03-01

Existing automated test assembly methods typically employ constrained combinatorial optimization. Constructing forms sequentially based on an optimization approach usually results in unparallel forms and requires heuristic modifications. Methods based on a random search approach have the major advantage of producing parallel forms sequentially without further adjustment. This study incorporated a flexible content-balancing element into the statistical perspective item selection method of the cell-only method (Chen et al. in Educational and Psychological Measurement, 72(6), 933-953, 2012). The new method was compared with a sequential interitem distance weighted deviation model (IID WDM) (Swanson & Stocking in Applied Psychological Measurement, 17(2), 151-166, 1993), a simultaneous IID WDM, and a big-shadow-test mixed integer programming (BST MIP) method to construct multiple parallel forms based on matching a reference form item-by-item. The results showed that the cell-only method with content balancing and the sequential and simultaneous versions of IID WDM yielded results comparable to those obtained using the BST MIP method. The cell-only method with content balancing is computationally less intensive than the sequential and simultaneous versions of IID WDM.

Combined use of Kappa Free Light Chain Index and Isoelectrofocusing of Cerebro-Spinal Fluid in Diagnosing Multiple Sclerosis: Performances and Costs.

PubMed

Crespi, Ilaria; Sulas, Maria Giovanna; Mora, Riccardo; Naldi, Paola; Vecchio, Domizia; Comi, Cristoforo; Cantello, Roberto; Bellomo, Giorgio

2017-03-01

Isoelectrofocusing (IEF) to detect oligoclonal bands (OBCs) in cerebrospinal fluid (CSF) is the gold standard approach for evaluating intrathecal immunoglobulin synthesis in multiple sclerosis (MS) but the kappa free light chain index (KFLCi) is emerging as an alternative marker, and the combined/sequential uses of IEF and KFLCi have never been challenged. CSF and serum albumin, IgG, kFLC and lFLC were measured by nephelometry; albumin, IgG and kFLC quotients as well as Link and kFLC indexes were calculated; OCBs were evaluated by immunofixation. A total of 150 consecutive patients: 48 with MS, 32 with other neurological inflammatory diseases (NID), 62 with neurological non-inflammatory diseases (NNID), and 8 without any detectable neurological disease (NND) were investigated. Both IEF and KFLCi showed a similar accuracy as diagnostic tests for multiple sclerosis. The high sensitivity and specificity associated with the lower cost of KFLCi suggested to use this test first, followed by IEF as a confirmative procedure. The sequential use of IEF and KFLCi showed high diagnostic efficiency with cost reduction of 43 and 21%, if compared to the contemporary use of both tests, or the unique use of IEF in all patients. The "sequential testing" using KFLCi followed by IEF in MS represents an optimal procedure with accurate performance and lower costs.

Photoacoustic spectroscopy sample array vessels and photoacoustic spectroscopy methods for using the same

DOEpatents

Amonette, James E.; Autrey, S. Thomas; Foster-Mills, Nancy S.

2006-02-14

Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. Particularly, a photoacoustic spectroscopy sample array vessel including a vessel body having multiple sample cells connected thereto is disclosed. At least one acoustic detector is acoustically positioned near the sample cells. Methods for analyzing the multiple samples in the sample array vessels using photoacoustic spectroscopy are provided.

Temporal Characteristics of Radiologists' and Novices' Lesion Detection in Viewing Medical Images Presented Rapidly and Sequentially.

PubMed

Nakashima, Ryoichi; Komori, Yuya; Maeda, Eriko; Yoshikawa, Takeharu; Yokosawa, Kazuhiko

2016-01-01

Although viewing multiple stacks of medical images presented on a display is a relatively new but useful medical task, little is known about this task. Particularly, it is unclear how radiologists search for lesions in this type of image reading. When viewing cluttered and dynamic displays, continuous motion itself does not capture attention. Thus, it is effective for the target detection that observers' attention is captured by the onset signal of a suddenly appearing target among the continuously moving distractors (i.e., a passive viewing strategy). This can be applied to stack viewing tasks, because lesions often show up as transient signals in medical images which are sequentially presented simulating a dynamic and smoothly transforming image progression of organs. However, it is unclear whether observers can detect a target when the target appears at the beginning of a sequential presentation where the global apparent motion onset signal (i.e., signal of the initiation of the apparent motion by sequential presentation) occurs. We investigated the ability of radiologists to detect lesions during such tasks by comparing the performances of radiologists and novices. Results show that overall performance of radiologists is better than novices. Furthermore, the temporal locations of lesions in CT image sequences, i.e., when a lesion appears in an image sequence, does not affect the performance of radiologists, whereas it does affect the performance of novices. Results indicate that novices have greater difficulty in detecting a lesion appearing early than late in the image sequence. We suggest that radiologists have other mechanisms to detect lesions in medical images with little attention which novices do not have. This ability is critically important when viewing rapid sequential presentations of multiple CT images, such as stack viewing tasks.

Temporal Characteristics of Radiologists' and Novices' Lesion Detection in Viewing Medical Images Presented Rapidly and Sequentially

PubMed Central

Nakashima, Ryoichi; Komori, Yuya; Maeda, Eriko; Yoshikawa, Takeharu; Yokosawa, Kazuhiko

2016-01-01

Although viewing multiple stacks of medical images presented on a display is a relatively new but useful medical task, little is known about this task. Particularly, it is unclear how radiologists search for lesions in this type of image reading. When viewing cluttered and dynamic displays, continuous motion itself does not capture attention. Thus, it is effective for the target detection that observers' attention is captured by the onset signal of a suddenly appearing target among the continuously moving distractors (i.e., a passive viewing strategy). This can be applied to stack viewing tasks, because lesions often show up as transient signals in medical images which are sequentially presented simulating a dynamic and smoothly transforming image progression of organs. However, it is unclear whether observers can detect a target when the target appears at the beginning of a sequential presentation where the global apparent motion onset signal (i.e., signal of the initiation of the apparent motion by sequential presentation) occurs. We investigated the ability of radiologists to detect lesions during such tasks by comparing the performances of radiologists and novices. Results show that overall performance of radiologists is better than novices. Furthermore, the temporal locations of lesions in CT image sequences, i.e., when a lesion appears in an image sequence, does not affect the performance of radiologists, whereas it does affect the performance of novices. Results indicate that novices have greater difficulty in detecting a lesion appearing early than late in the image sequence. We suggest that radiologists have other mechanisms to detect lesions in medical images with little attention which novices do not have. This ability is critically important when viewing rapid sequential presentations of multiple CT images, such as stack viewing tasks. PMID:27774080

64 slice MDCT generally underestimates coronary calcium scores as compared to EBT: A phantom study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greuter, M. J. W.; Dijkstra, H.; Groen, J. M.

The objective of our study was the determination of the influence of the sequential and spiral acquisition modes on the concordance and deviation of the calcium score on 64-slice multi-detector computed tomography (MDCT) scanners in comparison to electron beam tomography (EBT) as the gold standard. Our methods and materials were an anthropomorphic cardio CT phantom with different calcium inserts scanned in sequential and spiral acquisition modes on three identical 64-slice MDCT scanners of manufacturer A and on three identical 64-slice MDCT scanners of manufacturer B and on an EBT system. Every scan was repeated 30 times with and 15 timesmore » without a small random variation in the phantom position for both sequential and spiral modes. Significant differences were observed between EBT and 64-slice MDCT data for all inserts, both acquisition modes, and both manufacturers of MDCT systems. High regression coefficients (0.90-0.98) were found between the EBT and 64-slice MDCT data for both scoring methods and both systems with high correlation coefficients (R{sup 2}>0.94). System A showed more significant differences between spiral and sequential mode than system B. Almost no differences were observed in scanners of the same manufacturer for the Agatston score and no differences for the Volume score. The deviations of the Agatston and Volume scores showed regression dependencies approximately equal to the square root of the absolute score. The Agatston and Volume scores obtained with 64-slice MDCT imaging are highly correlated with EBT-obtained scores but are significantly underestimated (-10% to -2%) for both sequential and spiral acquisition modes. System B is more independent of acquisition mode to calcium score than system A. The Volume score shows no intramanufacturer dependency and its use is advocated versus the Agatston score. Using the same cut points for MDCT-based calcium scores as for EBT-based calcium scores can result in classifying individuals into a too low risk category. System information and scanprotocol is therefore needed for every calcium score procedure to ensure a correct clinical interpretation of the obtained calcium score results.« less

Clinical and Radiologic Predictive Factors of Rib Fractures in Outpatients With Chest Pain.

PubMed

Zhang, Liang; McMahon, Colm J; Shah, Samir; Wu, Jim S; Eisenberg, Ronald L; Kung, Justin W

To identify the clinical and radiologic predictive factors of rib fractures in stable adult outpatients presenting with chest pain and to determine the utility of dedicated rib radiographs in this population of patients. Following Institutional Review Board approval, we performed a retrospective review of 339 consecutive cases in which a frontal chest radiograph and dedicated rib series had been obtained for chest pain in the outpatient setting. The frontal chest radiograph and dedicated rib series were sequentially reviewed in consensus by two fellowship-trained musculoskeletal radiologists blinded to the initial report. The consensus interpretation of the dedicated rib series was used as the gold standard. Multiple variable logistic regression analysis assessed clinical and radiological factors associated with rib fractures. Fisher exact test was used to assess differences in medical treatment between the 2 groups. Of the 339 patients, 53 (15.6%) had at least 1 rib fracture. Only 20 of the 53 (37.7%) patients' fractures could be identified on the frontal chest radiograph. The frontal chest radiograph had a sensitivity of 38% and specificity of 100% when using the rib series as the reference standard. No pneumothorax, new mediastinal widening or pulmonary contusion was identified. Multiple variable logistic regression analysis of clinical factors associated with the presence of rib fractures revealed a significant association of trauma history (odds ratio 5.7 [p < 0.05]) and age ≥40 (odds radio 3.1 [p < 0.05]). Multiple variable logistic regression analysis of radiographic factors associated with rib fractures in this population demonstrated a significant association of pleural effusion with rib fractures (odds ratio 18.9 [p < 0.05]). Patients with rib fractures received narcotic analgesia in 47.2% of the cases, significantly more than those without rib fractures (21.3%, p < 0.05). None of the patients required hospitalization. In the stable outpatient setting, rib fractures have a higher association with a history of minor trauma and age ≥40 in the adult population. Radiographic findings associated with rib fractures include pleural effusion. The frontal chest radiograph alone has low sensitivity in detecting rib fractures. The dedicated rib series detected a greater number of rib fractures. Although no patients required hospitalization, those with rib fractures were more likely to receive narcotic analgesia. Copyright © 2018 Elsevier Inc. All rights reserved.

Acute radiation nephritis. Its evolution on sequential bone imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palestro, C.; Fineman, D.; Goldsmith, S.J.

1988-11-01

Acute radiation nephritis typically affects the kidneys 3-12 months after radiation exposure and may occur with doses as low as 2500 rads. After an initial latent period, the affected portions of the kidneys become swollen and edematous, and develop multiple petechiae. Necrotizing vasculitis and interstitial hemorrhage occur, and the end stage is that of scarring. Two patients are presented in whom localized acute radiation nephritis developed, and whose kidneys demonstrated the characteristic sequential changes of this entity on serial bone imaging.

Three-dimensional mapping of equiprobable hydrostratigraphic units at the Frenchman Flat Corrective Action Unit, Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirley, C.; Pohlmann, K.; Andricevic, R.

1996-09-01

Geological and geophysical data are used with the sequential indicator simulation algorithm of Gomez-Hernandez and Srivastava to produce multiple, equiprobable, three-dimensional maps of informal hydrostratigraphic units at the Frenchman Flat Corrective Action Unit, Nevada Test Site. The upper 50 percent of the Tertiary volcanic lithostratigraphic column comprises the study volume. Semivariograms are modeled from indicator-transformed geophysical tool signals. Each equiprobable study volume is subdivided into discrete classes using the ISIM3D implementation of the sequential indicator simulation algorithm. Hydraulic conductivity is assigned within each class using the sequential Gaussian simulation method of Deutsch and Journel. The resulting maps show the contiguitymore » of high and low hydraulic conductivity regions.« less

Sequential Participation in a Multi-Institutional Mock Oral Examination Is Associated With Improved American Board of Surgery Certifying Examination First-Time Pass Rate.

PubMed

Fingeret, Abbey L; Arnell, Tracey; McNelis, John; Statter, Mindy; Dresner, Lisa; Widmann, Warren

We sought to determine whether sequential participation in a multi-institutional mock oral examination affected the likelihood of passing the American Board of Surgery Certifying Examination (ABSCE) in first attempt. Residents from 3 academic medical centers were able to participate in a regional mock oral examination in the fall and spring of their fourth and fifth postgraduate year from 2011 to 2014. Candidate׳s highest composite score of all mock orals attempts was classified as risk for failure, intermediate, or likely to pass. Factors including United States Medical Licensing Examination steps 1, 2, and 3, number of cases logged, American Board of Surgery In-Training Examination performance, American Board of Surgery Qualifying Examination (ABSQE) performance, number of attempts, and performance in the mock orals were assessed to determine factors predictive of passing the ABSCE. A total of 128 mock oral examinations were administered to 88 (71%) of 124 eligible residents. The overall first-time pass rate for the ABSCE was 82%. There was no difference in pass rates between participants and nonparticipants. Of them, 16 (18%) residents were classified as at risk, 47 (53%) as intermediate, and 25 (29%) as likely to pass. ABSCE pass rate for each group was as follows: 36% for at risk, 84% for intermediate, and 96% for likely pass. The following 4 factors were associated with first-time passing of ABSCE on bivariate analysis: mock orals participation in postgraduate year 4 (p = 0.05), sequential participation in mock orals (p = 0.03), ABSQE performance (p = 0.01), and best performance on mock orals (p = 0.001). In multivariable logistic regression, the following 3 factors remained associated with ABSCE passing: ABSQE performance, odds ratio (OR) = 2.9 (95% CI: 1.3-6.1); mock orals best performance, OR = 1.7 (1.2-2.4); and participation in multiple mock oral examinations, OR = 1.4 (1.1-2.7). Performance on a multi-institutional mock oral examination can identify residents at risk for failure of the ABSCE. Sequential participation in mock oral examinations is associated with improved ABSCE first-time pass rate. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

USGS Publications Warehouse

DeBoer, Jason A.; Pope, Kevin L.

2015-01-01

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment.

ON THE COMPLEMENTARITY OF PULSAR TIMING AND SPACE LASER INTERFEROMETRY FOR THE INDIVIDUAL DETECTION OF SUPERMASSIVE BLACK HOLE BINARIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spallicci, Alessandro D. A. M., E-mail: spallicci@cnrs-orleans.fr

2013-02-20

Gravitational waves coming from supermassive black hole binaries (SMBHBs) are targeted by both the Pulsar Timing Array (PTA) and Space Laser Interferometry (SLI). The possibility of a single SMBHB being tracked first by PTA, through inspiral, and later by SLI, up to merger and ring-down, has been previously suggested. Although the bounding parameters are drawn by the current PTA or the upcoming Square Kilometer Array (SKA), and by the New Gravitational Observatory (NGO), derived from the Laser Interferometer Space Antenna (LISA), this paper also addresses sequential detection beyond specific project constraints. We consider PTA-SKA, which is sensitive from 10{sup -9}more » to p Multiplication-Sign 10{sup -7} Hz (p = 4, 8), and SLI, which operates from s Multiplication-Sign 10{sup -5} up to 1 Hz (s = 1, 3). An SMBHB in the range of 2 Multiplication-Sign 10{sup 8}-2 Multiplication-Sign 10{sup 9} M {sub Sun} (the masses are normalized to a (1 + z) factor, the redshift lying between z = 0.2 and z = 1.5) moves from the PTA-SKA to the SLI band over a period ranging from two months to fifty years. By combining three supermassive black hole (SMBH)-host relations with three accretion prescriptions, nine astrophysical scenarios are formed. They are then related to three levels of pulsar timing residuals (50, 5, 1 ns), generating 27 cases. For residuals of 1 ns, sequential detection probability will never be better than 4.7 Multiplication-Sign 10{sup -4} yr{sup -2} or 3.3 Multiplication-Sign 10{sup -6} yr{sup -2} (per year to merger and per year of survey), according to the best and worst astrophysical scenarios, respectively; put differently this means one sequential detection every 46 or 550 years for an equivalent maximum time to merger and duration of the survey. The chances of sequential detection are further reduced by increasing values of the s parameter (they vanish for s = 10) and of the SLI noise, and by decreasing values of the remnant spin. The spread in the predictions diminishes when timing precision is improved or the SLI low-frequency cutoff is lowered. So while transit times and the SLI signal-to-noise ratio (S/N) may be adequate, the likelihood of sequential detection is severely hampered by the current estimates on the number-just a handful-of individual inspirals observable by PTA-SKA, and to a lesser extent by the wide gap between the pulsar timing and space interferometry bands, and by the severe requirements on pulsar timing residuals. Optimization of future operational scenarios for SKA and SLI is briefly dealt with, since a detection of even a single event would be of paramount importance for the understanding of SMBHBs and of the astrophysical processes connected to their formation and evolution.« less

C-learning: A new classification framework to estimate optimal dynamic treatment regimes.

PubMed

Zhang, Baqun; Zhang, Min

2017-12-11

A dynamic treatment regime is a sequence of decision rules, each corresponding to a decision point, that determine that next treatment based on each individual's own available characteristics and treatment history up to that point. We show that identifying the optimal dynamic treatment regime can be recast as a sequential optimization problem and propose a direct sequential optimization method to estimate the optimal treatment regimes. In particular, at each decision point, the optimization is equivalent to sequentially minimizing a weighted expected misclassification error. Based on this classification perspective, we propose a powerful and flexible C-learning algorithm to learn the optimal dynamic treatment regimes backward sequentially from the last stage until the first stage. C-learning is a direct optimization method that directly targets optimizing decision rules by exploiting powerful optimization/classification techniques and it allows incorporation of patient's characteristics and treatment history to improve performance, hence enjoying advantages of both the traditional outcome regression-based methods (Q- and A-learning) and the more recent direct optimization methods. The superior performance and flexibility of the proposed methods are illustrated through extensive simulation studies. © 2017, The International Biometric Society.

A multiple imputation strategy for sequential multiple assignment randomized trials

PubMed Central

Shortreed, Susan M.; Laber, Eric; Stroup, T. Scott; Pineau, Joelle; Murphy, Susan A.

2014-01-01

Sequential multiple assignment randomized trials (SMARTs) are increasingly being used to inform clinical and intervention science. In a SMART, each patient is repeatedly randomized over time. Each randomization occurs at a critical decision point in the treatment course. These critical decision points often correspond to milestones in the disease process or other changes in a patient’s health status. Thus, the timing and number of randomizations may vary across patients and depend on evolving patient-specific information. This presents unique challenges when analyzing data from a SMART in the presence of missing data. This paper presents the first comprehensive discussion of missing data issues typical of SMART studies: we describe five specific challenges, and propose a flexible imputation strategy to facilitate valid statistical estimation and inference using incomplete data from a SMART. To illustrate these contributions, we consider data from the Clinical Antipsychotic Trial of Intervention and Effectiveness (CATIE), one of the most well-known SMARTs to date. PMID:24919867

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap.

PubMed

Snyder, Dalton T; Szalwinski, Lucas J; Cooks, R Graham

2017-10-17

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MS n operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Sequential Prediction of Literacy Achievement for Specific Learning Disabilities Contrasting in Impaired Levels of Language in Grades 4 to 9.

PubMed

Sanders, Elizabeth A; Berninger, Virginia W; Abbott, Robert D

Sequential regression was used to evaluate whether language-related working memory components uniquely predict reading and writing achievement beyond cognitive-linguistic translation for students in Grades 4 through 9 ( N = 103) with specific learning disabilities (SLDs) in subword handwriting (dysgraphia, n = 25), word reading and spelling (dyslexia, n = 60), or oral and written language (oral and written language learning disabilities, n = 18). That is, SLDs are defined on the basis of cascading level of language impairment (subword, word, and syntax/text). A five-block regression model sequentially predicted literacy achievement from cognitive-linguistic translation (Block 1); working memory components for word-form coding (Block 2), phonological and orthographic loops (Block 3), and supervisory focused or switching attention (Block 4); and SLD groups (Block 5). Results showed that cognitive-linguistic translation explained an average of 27% and 15% of the variance in reading and writing achievement, respectively, but working memory components explained an additional 39% and 27% of variance. Orthographic word-form coding uniquely predicted nearly every measure, whereas attention switching uniquely predicted only reading. Finally, differences in reading and writing persisted between dyslexia and dysgraphia, with dysgraphia higher, even after controlling for Block 1 to 4 predictors. Differences in literacy achievement between students with dyslexia and oral and written language learning disabilities were largely explained by the Block 1 predictors. Applications to identifying and teaching students with these SLDs are discussed.

Comparing Assessments of Students' Knowledge by Computerized Open-Ended and Multiple-Choice Tests.

ERIC Educational Resources Information Center

Anbar, Michael

1991-01-01

Interactive computerized tests accepting unrestricted natural-language input were used to assess knowledge of clinical biophysics at the State University of New York at Buffalo. Comparison of responses to open-ended sequential questions and multiple-choice questions on the same material found the two formats test different aspects of competence.…

Benefit and predictive factors for speech perception outcomes in pediatric bilateral cochlear implant recipients.

PubMed

Chang, Young-Soo; Hong, Sung Hwa; Kim, Eun Yeon; Choi, Ji Eun; Chung, Won-Ho; Cho, Yang-Sun; Moon, Il Joon

2018-05-18

Despite recent advancement in the prediction of cochlear implant outcome, the benefit of bilateral procedures compared to bimodal stimulation and how we predict speech perception outcomes of sequential bilateral cochlear implant based on bimodal auditory performance in children remain unclear. This investigation was performed: (1) to determine the benefit of sequential bilateral cochlear implant and (2) to identify the associated factors for the outcome of sequential bilateral cochlear implant. Observational and retrospective study. We retrospectively analyzed 29 patients with sequential cochlear implant following bimodal-fitting condition. Audiological evaluations were performed; the categories of auditory performance scores, speech perception with monosyllable and disyllables words, and the Korean version of Ling. Audiological evaluations were performed before sequential cochlear implant with the bimodal fitting condition (CI1+HA) and one year after the sequential cochlear implant with bilateral cochlear implant condition (CI1+CI2). The good Performance Group (GP) was defined as follows; 90% or higher in monosyllable and bisyllable tests with auditory-only condition or 20% or higher improvement of the scores with CI1+CI2. Age at first implantation, inter-implant interval, categories of auditory performance score, and various comorbidities were analyzed by logistic regression analysis. Compared to the CI1+HA, CI1+CI2 provided significant benefit in categories of auditory performance, speech perception, and Korean version of Ling results. Preoperative categories of auditory performance scores were the only associated factor for being GP (odds ratio=4.38, 95% confidence interval - 95%=1.07-17.93, p=0.04). The children with limited language development in bimodal condition should be considered as the sequential bilateral cochlear implant and preoperative categories of auditory performance score could be used as the predictor in speech perception after sequential cochlear implant. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Toward a Better Understanding of Student Perceptions of Writing Feedback: A Mixed Methods Study

ERIC Educational Resources Information Center

Zumbrunn, Sharon; Marrs, Sarah; Mewborn, Caitlin

2016-01-01

This explanatory sequential mixed methods study investigated the writing feedback perceptions of middle and high school students (N = 598). The predictive and mediational roles of writing self-efficacy and perceptions of writing feedback on student writing self-regulation aptitude were examined using mediation regression analysis. To augment the…

Transitioning Transfer Students: Interactive Factors that Influence First-Year Retention

ERIC Educational Resources Information Center

Luo, Mingchu; Williams, James E.; Vieweg, Bruce

2007-01-01

This study examined the diverse patterns of interactive factors that influence transfer students' first-year retention at a midsize four-year university. The population for this study consisted of five cohorts totaling 1,713 full-time, degree-seeking transfer students. Sequential sets of logistic regression analyses on blocks of variables were…

Multiple Correlation versus Multiple Regression.

ERIC Educational Resources Information Center

Huberty, Carl J.

2003-01-01

Describes differences between multiple correlation analysis (MCA) and multiple regression analysis (MRA), showing how these approaches involve different research questions and study designs, different inferential approaches, different analysis strategies, and different reported information. (SLD)

A clinical study of electrophysiological correlates of behavioural comfort levels in cochlear implantees.

PubMed

Raghunandhan, S; Ravikumar, A; Kameswaran, Mohan; Mandke, Kalyani; Ranjith, R

2014-05-01

Indications for cochlear implantation have expanded today to include very young children and those with syndromes/multiple handicaps. Programming the implant based on behavioural responses may be tedious for audiologists in such cases, wherein matching an effective Measurable Auditory Percept (MAP) and appropriate MAP becomes the key issue in the habilitation program. In 'Difficult to MAP' scenarios, objective measures become paramount to predict optimal current levels to be set in the MAP. We aimed to (a) study the trends in multi-modal electrophysiological tests and behavioural responses sequentially over the first year of implant use; (b) generate normative data from the above; (c) correlate the multi-modal electrophysiological thresholds levels with behavioural comfort levels; and (d) create predictive formulae for deriving optimal comfort levels (if unknown), using linear and multiple regression analysis. This prospective study included 10 profoundly hearing impaired children aged between 2 and 7 years with normal inner ear anatomy and no additional handicaps. They received the Advanced Bionics HiRes 90 K Implant with Harmony Speech processor and used HiRes-P with Fidelity 120 strategy. They underwent, impedance telemetry, neural response imaging, electrically evoked stapedial response telemetry (ESRT), and electrically evoked auditory brainstem response (EABR) tests at 1, 4, 8, and 12 months of implant use, in conjunction with behavioural mapping. Trends in electrophysiological and behavioural responses were analyzed using paired t-test. By Karl Pearson's correlation method, electrode-wise correlations were derived for neural response imaging (NRI) thresholds versus most comfortable level (M-levels) and offset based (apical, mid-array, and basal array) correlations for EABR and ESRT thresholds versus M-levels were calculated over time. These were used to derive predictive formulae by linear and multiple regression analysis. Such statistically predicted M-levels were compared with the behaviourally recorded M-levels among the cohort, using Cronbach's alpha reliability test method for confirming the efficacy of this method. NRI, ESRT, and EABR thresholds showed statistically significant positive correlations with behavioural M-levels, which improved with implant use over time. These correlations were used to derive predicted M-levels using regression analysis. On an average, predicted M-levels were found to be statistically reliable and they were a fair match to the actual behavioural M-levels. When applied in clinical practice, the predicted values were found to be useful for programming members of the study group. However, individuals showed considerable deviations in behavioural M-levels, above and below the electrophysiologically predicted values, due to various factors. While the current method appears helpful as a reference to predict initial maps in 'difficult to Map' subjects, it is recommended that behavioural measures are mandatory to further optimize the maps for these individuals. The study explores the trends, correlations and individual variabilities that occur between electrophysiological tests and behavioural responses, recorded over time among a cohort of cochlear implantees. The statistical method shown may be used as a guideline to predict optimal behavioural levels in difficult situations among future implantees, bearing in mind that optimal M-levels for individuals can vary from predicted values. In 'Difficult to MAP' scenarios, following a protocol of sequential behavioural programming, in conjunction with electrophysiological correlates will provide the best outcomes.

The Detection and Interpretation of Interaction Effects between Continuous Variables in Multiple Regression.

ERIC Educational Resources Information Center

Jaccard, James; And Others

1990-01-01

Issues in the detection and interpretation of interaction effects between quantitative variables in multiple regression analysis are discussed. Recent discussions associated with problems of multicollinearity are reviewed in the context of the conditional nature of multiple regression with product terms. (TJH)

The B Cell Response to Foot-and-Mouth Disease Virus in Cattle following Sequential Vaccination with Multiple Serotypes.

PubMed

Grant, Clare F J; Carr, B Veronica; Kotecha, Abhay; van den Born, Erwin; Stuart, David I; Hammond, John A; Charleston, Bryan

2017-05-01

Foot-and-mouth disease virus (FMDV) is a highly contagious viral disease. Antibodies are pivotal in providing protection against FMDV infection. Serological protection against one FMDV serotype does not confer interserotype protection. However, some historical data have shown that interserotype protection can be induced following sequential FMDV challenge with multiple FMDV serotypes. In this study, we have investigated the kinetics of the FMDV-specific antibody-secreting cell (ASC) response following homologous and heterologous inactivated FMDV vaccination regimes. We have demonstrated that the kinetics of the B cell response are similar for all four FMDV serotypes tested following a homologous FMDV vaccination regime. When a heterologous vaccination regime was used with the sequential inoculation of three different inactivated FMDV serotypes (O, A, and Asia1 serotypes) a B cell response to FMDV SAT1 and serotype C was induced. The studies also revealed that the local lymphoid tissue had detectable FMDV-specific ASCs in the absence of circulating FMDV-specific ASCs, indicating the presence of short-lived ASCs, a hallmark of a T-independent 2 (TI-2) antigenic response to inactivated FMDV capsid. IMPORTANCE We have demonstrated the development of intraserotype response following a sequential vaccination regime of four different FMDV serotypes. We have found indication of short-lived ASCs in the local lymphoid tissue, further evidence of a TI-2 response to FMDV. Copyright © 2017 American Society for Microbiology.

Computer-Based Radiographic Quantification of Joint Space Narrowing Progression Using Sequential Hand Radiographs: Validation Study in Rheumatoid Arthritis Patients from Multiple Institutions.

PubMed

Ichikawa, Shota; Kamishima, Tamotsu; Sutherland, Kenneth; Fukae, Jun; Katayama, Kou; Aoki, Yuko; Okubo, Takanobu; Okino, Taichi; Kaneda, Takahiko; Takagi, Satoshi; Tanimura, Kazuhide

2017-10-01

We have developed a refined computer-based method to detect joint space narrowing (JSN) progression with the joint space narrowing progression index (JSNPI) by superimposing sequential hand radiographs. The purpose of this study is to assess the validity of a computer-based method using images obtained from multiple institutions in rheumatoid arthritis (RA) patients. Sequential hand radiographs of 42 patients (37 females and 5 males) with RA from two institutions were analyzed by a computer-based method and visual scoring systems as a standard of reference. The JSNPI above the smallest detectable difference (SDD) defined JSN progression on the joint level. The sensitivity and specificity of the computer-based method for JSN progression was calculated using the SDD and a receiver operating characteristic (ROC) curve. Out of 314 metacarpophalangeal joints, 34 joints progressed based on the SDD, while 11 joints widened. Twenty-one joints progressed in the computer-based method, 11 joints in the scoring systems, and 13 joints in both methods. Based on the SDD, we found lower sensitivity and higher specificity with 54.2 and 92.8%, respectively. At the most discriminant cutoff point according to the ROC curve, the sensitivity and specificity was 70.8 and 81.7%, respectively. The proposed computer-based method provides quantitative measurement of JSN progression using sequential hand radiographs and may be a useful tool in follow-up assessment of joint damage in RA patients.

Plasmacytoid dendritic cells induce NK cell-dependent, tumor antigen-specific T cell cross-priming and tumor regression in mice.

PubMed

Liu, Chengwen; Lou, Yanyan; Lizée, Gregory; Qin, Hong; Liu, Shujuan; Rabinovich, Brian; Kim, Grace J; Wang, Yi-Hong; Ye, Yang; Sikora, Andrew G; Overwijk, Willem W; Liu, Yong-Jun; Wang, Gang; Hwu, Patrick

2008-03-01

A prerequisite for strong adaptive antiviral immunity is the robust initial activation of the innate immune system, which is frequently mediated by TLR-activated plasmacytoid DCs (pDCs). Natural antitumor immunity is often comparatively weak, potentially due to the lack of TLR-mediated activation signals within the tumor microenvironment. To assess whether pDCs are capable of directly facilitating effective antitumor immune responses, mice bearing established subcutaneous B16 melanoma tumors were administered TLR9-activated pDCs directly into the tumor. We found that TLR9-activated pDCs induced robust, spontaneous CTL cross-priming against multiple B16 tumor antigens, leading to the regression of both treated tumors and untreated tumors at distant contralateral sites. This T cell cross-priming was mediated by conventional DCs (cDCs) and was completely dependent upon the early recruitment and activation of NK cells at the tumor site. NK cell recruitment was mediated by CCR5 via chemokines secreted by pDCs, and optimal IFN-gamma production by NK cells was mediated by OX40L expressed by pDCs. Our data thus demonstrated that activated pDCs are capable of initiating effective and systemic antitumor immunity through the orchestration of an immune cascade involving the sequential activation of NK cells, cDCs, and CD8(+) T cells.

Simultaneous and sequential hemorrhage of multiple cerebral cavernous malformations: a case report.

PubMed

Louis, Nundia; Marsh, Robert

2016-02-09

The etiology of cerebral cavernous malformation hemorrhage is not well understood. Causative physiologic parameters preceding hemorrhagic cavernous malformation events are often not reported. We present a case of an individual with sequential simultaneous hemorrhages in multiple cerebral cavernous malformations with a new onset diagnosis of hypertension. A 42-year-old white man was admitted to our facility with worsening headache, left facial and tongue numbness, dizziness, diplopia, and elevated blood pressure. His past medical history was significant for new onset diagnosis of hypertension and chronic seasonal allergies. Serial imaging over the ensuing 8 days revealed sequential hemorrhagic lesions. He underwent suboccipital craniotomy for resection of the lesions located in the fourth ventricle and right cerebellum. One month after surgery, he had near complete resolution of his symptoms with mild residual vertigo but symptomatic chronic hypertension. Many studies have focused on genetic and inflammatory mechanisms contributing to cerebral cavernous malformation rupture, but few have reported on the potential of hemodynamic changes contributing to cerebral cavernous malformation rupture. Systemic blood pressure changes clearly have an effect on angioma pressures. When considering the histopathological features of cerebral cavernous malformation architecture, changes in arterial pressure could cause meaningful alterations in hemorrhage propensity and patterns.

Beyond Multiple Regression: Using Commonality Analysis to Better Understand R[superscript 2] Results

ERIC Educational Resources Information Center

Warne, Russell T.

2011-01-01

Multiple regression is one of the most common statistical methods used in quantitative educational research. Despite the versatility and easy interpretability of multiple regression, it has some shortcomings in the detection of suppressor variables and for somewhat arbitrarily assigning values to the structure coefficients of correlated…

Multiplication factor versus regression analysis in stature estimation from hand and foot dimensions.

PubMed

Krishan, Kewal; Kanchan, Tanuj; Sharma, Abhilasha

2012-05-01

Estimation of stature is an important parameter in identification of human remains in forensic examinations. The present study is aimed to compare the reliability and accuracy of stature estimation and to demonstrate the variability in estimated stature and actual stature using multiplication factor and regression analysis methods. The study is based on a sample of 246 subjects (123 males and 123 females) from North India aged between 17 and 20 years. Four anthropometric measurements; hand length, hand breadth, foot length and foot breadth taken on the left side in each subject were included in the study. Stature was measured using standard anthropometric techniques. Multiplication factors were calculated and linear regression models were derived for estimation of stature from hand and foot dimensions. Derived multiplication factors and regression formula were applied to the hand and foot measurements in the study sample. The estimated stature from the multiplication factors and regression analysis was compared with the actual stature to find the error in estimated stature. The results indicate that the range of error in estimation of stature from regression analysis method is less than that of multiplication factor method thus, confirming that the regression analysis method is better than multiplication factor analysis in stature estimation. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Optical and structural properties of cobalt-permalloy slanted columnar heterostructure thin films

NASA Astrophysics Data System (ADS)

Sekora, Derek; Briley, Chad; Schubert, Mathias; Schubert, Eva

2017-11-01

Optical and structural properties of sequential Co-column-NiFe-column slanted columnar heterostructure thin films with an Al2O3 passivation coating are reported. Electron-beam evaporated glancing angle deposition is utilized to deposit the sequential multiple-material slanted columnar heterostructure thin films. Mueller matrix generalized spectroscopic ellipsometry data is analyzed with a best-match model approach employing the anisotropic Bruggeman effective medium approximation formalism to determine bulk-like and anisotropic optical and structural properties of the individual Co and NiFe slanted columnar material sub-layers. Scanning electron microscopy is applied to image the Co-NiFe sequential growth properties and to verify the results of the ellipsometric analysis. Comparisons to single-material slanted columnar thin films and optically bulk solid thin films are presented and discussed. We find that the optical and structural properties of each material sub-layer of the sequential slanted columnar heterostructure film are distinct from each other and resemble those of their respective single-material counterparts.

Hybrid Model Predictive Control for Sequential Decision Policies in Adaptive Behavioral Interventions.

PubMed

Dong, Yuwen; Deshpande, Sunil; Rivera, Daniel E; Downs, Danielle S; Savage, Jennifer S

2014-06-01

Control engineering offers a systematic and efficient method to optimize the effectiveness of individually tailored treatment and prevention policies known as adaptive or "just-in-time" behavioral interventions. The nature of these interventions requires assigning dosages at categorical levels, which has been addressed in prior work using Mixed Logical Dynamical (MLD)-based hybrid model predictive control (HMPC) schemes. However, certain requirements of adaptive behavioral interventions that involve sequential decision making have not been comprehensively explored in the literature. This paper presents an extension of the traditional MLD framework for HMPC by representing the requirements of sequential decision policies as mixed-integer linear constraints. This is accomplished with user-specified dosage sequence tables, manipulation of one input at a time, and a switching time strategy for assigning dosages at time intervals less frequent than the measurement sampling interval. A model developed for a gestational weight gain (GWG) intervention is used to illustrate the generation of these sequential decision policies and their effectiveness for implementing adaptive behavioral interventions involving multiple components.

Encoding Time in Feedforward Trajectories of a Recurrent Neural Network Model.

PubMed

Hardy, N F; Buonomano, Dean V

2018-02-01

Brain activity evolves through time, creating trajectories of activity that underlie sensorimotor processing, behavior, and learning and memory. Therefore, understanding the temporal nature of neural dynamics is essential to understanding brain function and behavior. In vivo studies have demonstrated that sequential transient activation of neurons can encode time. However, it remains unclear whether these patterns emerge from feedforward network architectures or from recurrent networks and, furthermore, what role network structure plays in timing. We address these issues using a recurrent neural network (RNN) model with distinct populations of excitatory and inhibitory units. Consistent with experimental data, a single RNN could autonomously produce multiple functionally feedforward trajectories, thus potentially encoding multiple timed motor patterns lasting up to several seconds. Importantly, the model accounted for Weber's law, a hallmark of timing behavior. Analysis of network connectivity revealed that efficiency-a measure of network interconnectedness-decreased as the number of stored trajectories increased. Additionally, the balance of excitation (E) and inhibition (I) shifted toward excitation during each unit's activation time, generating the prediction that observed sequential activity relies on dynamic control of the E/I balance. Our results establish for the first time that the same RNN can generate multiple functionally feedforward patterns of activity as a result of dynamic shifts in the E/I balance imposed by the connectome of the RNN. We conclude that recurrent network architectures account for sequential neural activity, as well as for a fundamental signature of timing behavior: Weber's law.

Support for distinct subcomponents of spatial working memory: a double dissociation between spatial-simultaneous and spatial-sequential performance in unilateral neglect.

PubMed

Wansard, Murielle; Bartolomeo, Paolo; Bastin, Christine; Segovia, Fermín; Gillet, Sophie; Duret, Christophe; Meulemans, Thierry

2015-01-01

Over the last decade, many studies have demonstrated that visuospatial working memory (VSWM) can be divided into separate subsystems dedicated to the retention of visual patterns and their serial order. Impaired VSWM has been suggested to exacerbate left visual neglect in right-brain-damaged individuals. The aim of this study was to investigate the segregation between spatial-sequential and spatial-simultaneous working memory in individuals with neglect. We demonstrated that patterns of results on these VSWM tasks can be dissociated. Spatial-simultaneous and sequential aspects of VSWM can be selectively impaired in unilateral neglect. Our results support the hypothesis of multiple VSWM subsystems, which should be taken into account to better understand neglect-related deficits.

Midline Shift is Unrelated to Subjective Pupillary Reactivity Assessment on Admission in Moderate and Severe Traumatic Brain Injury.

PubMed

Nourallah, Basil; Menon, David K; Zeiler, Frederick A

2018-04-04

This study aims to determine the relationship between pupillary reactivity, midline shift and basal cistern effacement on brain computed tomography (CT) in moderate-to-severe traumatic brain injury (TBI). All are important diagnostic and prognostic measures, but their relationship is unclear. A total of 204 patients with moderate-to-severe TBI, documented pupillary reactivity, and archived neuroimaging were included. Extent of midline shift and basal cistern effacement were extracted from admission brain CT. Mean midline shift was calculated for each ordinal category of pupillary reactivity and basal cistern effacement. Sequential Chi-square analysis was used to calculate a threshold midline shift for pupillary abnormalities and basal cistern effacement. Univariable and multiple logistic regression analyses were performed. Pupils were bilaterally reactive in 163 patients, unilaterally reactive in 24, and bilaterally unreactive in 17, with mean midline shift (mm) of 1.96, 3.75, and 2.56, respectively (p = 0.14). Basal cisterns were normal in 118 patients, compressed in 45, and absent in 41, with mean midline shift (mm) of 0.64, 2.97, and 5.93, respectively (p < 0.001). Sequential Chi-square analysis identified a threshold for abnormal pupils at a midline shift of 7-7.25 mm (p = 0.032), compressed basal cisterns at 2 mm (p < 0.001), and completely effaced basal cisterns at 7.5 mm (p < 0.001). Logistic regression revealed no association between midline shift and pupillary reactivity. With effaced basal cisterns, the odds ratio for normal pupils was 0.22 (95% CI 0.08-0.56; p = 0.0016) and for at least one unreactive pupil was 0.061 (95% CI 0.012-0.24; p < 0.001). Basal cistern effacement strongly predicted midline shift (OR 1.27; 95% CI 1.17-1.40; p < 0.001). Basal cistern effacement alone is associated with pupillary reactivity and is closely associated with midline shift. It may represent a uniquely useful neuroimaging marker to guide intervention in traumatic brain injury.

A Novel Ship-Tracking Method for GF-4 Satellite Sequential Images.

PubMed

Yao, Libo; Liu, Yong; He, You

2018-06-22

The geostationary remote sensing satellite has the capability of wide scanning, persistent observation and operational response, and has tremendous potential for maritime target surveillance. The GF-4 satellite is the first geostationary orbit (GEO) optical remote sensing satellite with medium resolution in China. In this paper, a novel ship-tracking method in GF-4 satellite sequential imagery is proposed. The algorithm has three stages. First, a local visual saliency map based on local peak signal-to-noise ratio (PSNR) is used to detect ships in a single frame of GF-4 satellite sequential images. Second, the accuracy positioning of each potential target is realized by a dynamic correction using the rational polynomial coefficients (RPCs) and automatic identification system (AIS) data of ships. Finally, an improved multiple hypotheses tracking (MHT) algorithm with amplitude information is used to track ships by further removing the false targets, and to estimate ships’ motion parameters. The algorithm has been tested using GF-4 sequential images and AIS data. The results of the experiment demonstrate that the algorithm achieves good tracking performance in GF-4 satellite sequential images and estimates the motion information of ships accurately.

Do Sequentially-Presented Answer Options Prevent the Use of Testwiseness Cues on Continuing Medical Education Tests?

ERIC Educational Resources Information Center

Willing, Sonja; Ostapczuk, Martin; Musch, Jochen

2015-01-01

Testwiseness--that is, the ability to find subtle cues towards the solution by the simultaneous comparison of the available answer options--threatens the validity of multiple-choice (MC) tests. Discrete-option multiple-choice (DOMC) has recently been proposed as a computerized alternative testing format for MC tests, and presumably allows for a…

The Effects of Multiple Exemplar Training on a Working Memory Task Involving Sequential Responding in Children with Autism

ERIC Educational Resources Information Center

Baltruschat, Lisa; Hasselhorn, Marcus; Tarbox, Jonathan; Dixon, Dennis R.; Najdowski, Adel; Mullins, Ryan David; Gould, Evelyn

2012-01-01

This study is part of a programmatic line of research into the use of basic positive reinforcement procedures for improving working memory in children with autism spectrum disorders. The authors evaluated the effects of multiple exemplar training, utilizing positive reinforcement, on performance of a "digit span backwards" task--a test of working…

Look Closer: The Alertness of People with Profound Intellectual and Multiple Disabilities during Multi-Sensory Storytelling, a Time Sequential Analysis

ERIC Educational Resources Information Center

Ten Brug, Annet; Munde, Vera S.; van der Putten, Annette A.J.; Vlaskamp, Carla

2015-01-01

Introduction: Multi-sensory storytelling (MSST) is a storytelling method designed for individuals with profound intellectual and multiple disabilities (PIMD). It is essential that listeners be alert during MSST, so that they become familiar with their personalised stories. Repetition and the presentation of stimuli are likely to affect the…

Error Control Coding Techniques for Space and Satellite Communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.; Cabral, Hermano A.; He, Jiali

1997-01-01

Bootstrap Hybrid Decoding (BHD) (Jelinek and Cocke, 1971) is a coding/decoding scheme that adds extra redundancy to a set of convolutionally encoded codewords and uses this redundancy to provide reliability information to a sequential decoder. Theoretical results indicate that bit error probability performance (BER) of BHD is close to that of Turbo-codes, without some of their drawbacks. In this report we study the use of the Multiple Stack Algorithm (MSA) (Chevillat and Costello, Jr., 1977) as the underlying sequential decoding algorithm in BHD, which makes possible an iterative version of BHD.

Using an innovative multiple regression procedure in a cancer population (Part II): fever, depressive affect, and mobility problems clarify an influential symptom pair (pain-fatigue/weakness) and cluster (pain-fatigue/weakness-sleep problems).

PubMed

Francoeur, Richard B

2015-01-01

Most patients with advanced cancer experience symptom pairs or clusters among pain, fatigue, and insomnia. However, only combinations where symptoms are mutually influential hold potential for identifying patient subgroups at greater risk, and in some contexts, interventions with "cross-over" (multisymptom) effects. Improved methods to detect and interpret interactions among symptoms, signs, or biomarkers are needed to reveal these influential pairs and clusters. I recently created sequential residual centering (SRC) to reduce multicollinearity in moderated regression, which enhances sensitivity to detect these interactions. I applied SRC to moderated regressions of single-item symptoms that interact to predict outcomes from 268 palliative radiation outpatients. I investigated: 1) the hypothesis that the interaction, pain × fatigue/weakness × sleep problems, predicts depressive affect only when fever presents, and 2) an exploratory analysis, when fever is absent, that the interaction, pain × fatigue/weakness × sleep problems × depressive affect, predicts mobility problems. In the fever context, three-way interactions (and derivative terms) of the four symptoms (pain, fatigue/weakness, fever, sleep problems) are tested individually and simultaneously; in the non-fever context, a single four-way interaction (and derivative terms) is tested. Fever interacts separately with fatigue/weakness and sleep problems; these comoderators each magnify the pain-depressive affect relationship along the upper or full range of pain values. In non-fever contexts, fatigue/weakness, sleep problems, and depressive affect comagnify the relationship between pain and mobility problems. Different mechanisms contribute to the pain × fatigue/weakness × sleep problems interaction, but all depend on the presence of fever, a sign/biomarker/symptom of proinflammatory sickness behavior. In non-fever contexts, depressive affect is no longer an outcome representing malaise from the physical symptoms of sickness, but becomes a fourth symptom of the interaction. In outpatient subgroups at heightened risk, single interventions could potentially relieve multiple symptoms when fever accompanies sickness malaise and in non-fever contexts with mobility problems. SRC strengthens insights into symptom pairs/clusters.

Early mortality in multiple myeloma: the time-dependent impact of comorbidity: A population-based study in 621 real-life patients.

PubMed

Ríos-Tamayo, Rafael; Sáinz, Juan; Martínez-López, Joaquín; Puerta, José Manuel; Chang, Daysi-Yoe-Ling; Rodríguez, Teresa; Garrido, Pilar; de Veas, José Luís García; Romero, Antonio; Moratalla, Lucía; López-Fernández, Elisa; González, Pedro Antonio; Sánchez, María José; Jiménez-Moleón, José Juan; Jurado, Manuel; Lahuerta, Juan José

2016-07-01

Multiple myeloma is a heterogeneous disease with variable survival; this variability cannot be fully explained by the current systems of risk stratification. Early mortality remains a serious obstacle to further improve the trend toward increased survival demonstrated in recent years. However, the definition of early mortality is not standardized yet. Importantly, no study has focused on the impact of comorbidity on early mortality in multiple myeloma to date. Therefore, we analyzed the role of baseline comorbidity in a large population-based cohort of 621 real-life myeloma patients over a 31-year period. To evaluate early mortality, a sequential multivariate regression model at 2, 6, and 12 months from diagnosis was performed. It was demonstrated that comorbidity had an independent impact on early mortality, which is differential and time-dependent. Besides renal failure, respiratory disease at 2 months, liver disease at 6 months, and hepatitis virus C infection at 12 months, were, respectively, associated with early mortality, adjusting for other well-established prognostic factors. On the other hand, the long-term monitoring in our study points out a modest downward trend in early mortality over time. This is the first single institution population-based study aiming to assess the impact of comorbidity on early mortality in multiple myeloma. It is suggested that early mortality should be analyzed at three key time points (2, 6, and 12 months), in order to allow comparisons between studies. Comorbidity plays a critical role in the outcome of myeloma patients in terms of early mortality. Am. J. Hematol. 91:700-704, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Prediction of hearing outcomes by multiple regression analysis in patients with idiopathic sudden sensorineural hearing loss.

PubMed

Suzuki, Hideaki; Tabata, Takahisa; Koizumi, Hiroki; Hohchi, Nobusuke; Takeuchi, Shoko; Kitamura, Takuro; Fujino, Yoshihisa; Ohbuchi, Toyoaki

2014-12-01

This study aimed to create a multiple regression model for predicting hearing outcomes of idiopathic sudden sensorineural hearing loss (ISSNHL). The participants were 205 consecutive patients (205 ears) with ISSNHL (hearing level ≥ 40 dB, interval between onset and treatment ≤ 30 days). They received systemic steroid administration combined with intratympanic steroid injection. Data were examined by simple and multiple regression analyses. Three hearing indices (percentage hearing improvement, hearing gain, and posttreatment hearing level [HLpost]) and 7 prognostic factors (age, days from onset to treatment, initial hearing level, initial hearing level at low frequencies, initial hearing level at high frequencies, presence of vertigo, and contralateral hearing level) were included in the multiple regression analysis as dependent and explanatory variables, respectively. In the simple regression analysis, the percentage hearing improvement, hearing gain, and HLpost showed significant correlation with 2, 5, and 6 of the 7 prognostic factors, respectively. The multiple correlation coefficients were 0.396, 0.503, and 0.714 for the percentage hearing improvement, hearing gain, and HLpost, respectively. Predicted values of HLpost calculated by the multiple regression equation were reliable with 70% probability with a 40-dB-width prediction interval. Prediction of HLpost by the multiple regression model may be useful to estimate the hearing prognosis of ISSNHL. © The Author(s) 2014.

Orphan therapies: making best use of postmarket data.

PubMed

Maro, Judith C; Brown, Jeffrey S; Dal Pan, Gerald J; Li, Lingling

2014-08-01

Postmarket surveillance of the comparative safety and efficacy of orphan therapeutics is challenging, particularly when multiple therapeutics are licensed for the same orphan indication. To make best use of product-specific registry data collected to fulfill regulatory requirements, we propose the creation of a distributed electronic health data network among registries. Such a network could support sequential statistical analyses designed to detect early warnings of excess risks. We use a simulated example to explore the circumstances under which a distributed network may prove advantageous. We perform sample size calculations for sequential and non-sequential statistical studies aimed at comparing the incidence of hepatotoxicity following initiation of two newly licensed therapies for homozygous familial hypercholesterolemia. We calculate the sample size savings ratio, or the proportion of sample size saved if one conducted a sequential study as compared to a non-sequential study. Then, using models to describe the adoption and utilization of these therapies, we simulate when these sample sizes are attainable in calendar years. We then calculate the analytic calendar time savings ratio, analogous to the sample size savings ratio. We repeat these analyses for numerous scenarios. Sequential analyses detect effect sizes earlier or at the same time as non-sequential analyses. The most substantial potential savings occur when the market share is more imbalanced (i.e., 90% for therapy A) and the effect size is closest to the null hypothesis. However, due to low exposure prevalence, these savings are difficult to realize within the 30-year time frame of this simulation for scenarios in which the outcome of interest occurs at or more frequently than one event/100 person-years. We illustrate a process to assess whether sequential statistical analyses of registry data performed via distributed networks may prove a worthwhile infrastructure investment for pharmacovigilance.

False Positives in Multiple Regression: Unanticipated Consequences of Measurement Error in the Predictor Variables

ERIC Educational Resources Information Center

Shear, Benjamin R.; Zumbo, Bruno D.

2013-01-01

Type I error rates in multiple regression, and hence the chance for false positive research findings, can be drastically inflated when multiple regression models are used to analyze data that contain random measurement error. This article shows the potential for inflated Type I error rates in commonly encountered scenarios and provides new…

Using Robust Standard Errors to Combine Multiple Regression Estimates with Meta-Analysis

ERIC Educational Resources Information Center

Williams, Ryan T.

2012-01-01

Combining multiple regression estimates with meta-analysis has continued to be a difficult task. A variety of methods have been proposed and used to combine multiple regression slope estimates with meta-analysis, however, most of these methods have serious methodological and practical limitations. The purpose of this study was to explore the use…

Use of Multiple Regression and Use-Availability Analyses in Determining Habitat Selection by Gray Squirrels (Sciurus Carolinensis)

Treesearch

John W. Edwards; Susan C. Loeb; David C. Guynn

1994-01-01

Multiple regression and use-availability analyses are two methods for examining habitat selection. Use-availability analysis is commonly used to evaluate macrohabitat selection whereas multiple regression analysis can be used to determine microhabitat selection. We compared these techniques using behavioral observations (n = 5534) and telemetry locations (n = 2089) of...

Building Regression Models: The Importance of Graphics.

ERIC Educational Resources Information Center

Dunn, Richard

1989-01-01

Points out reasons for using graphical methods to teach simple and multiple regression analysis. Argues that a graphically oriented approach has considerable pedagogic advantages in the exposition of simple and multiple regression. Shows that graphical methods may play a central role in the process of building regression models. (Author/LS)

Testing Different Model Building Procedures Using Multiple Regression.

ERIC Educational Resources Information Center

Thayer, Jerome D.

The stepwise regression method of selecting predictors for computer assisted multiple regression analysis was compared with forward, backward, and best subsets regression, using 16 data sets. The results indicated the stepwise method was preferred because of its practical nature, when the models chosen by different selection methods were similar…

Decreasing Multicollinearity: A Method for Models with Multiplicative Functions.

ERIC Educational Resources Information Center

Smith, Kent W.; Sasaki, M. S.

1979-01-01

A method is proposed for overcoming the problem of multicollinearity in multiple regression equations where multiplicative independent terms are entered. The method is not a ridge regression solution. (JKS)

Effects of transfer of embryos independently cultured in essential and sequential culture media on pregnancy rates in assisted reproduction cycles.

PubMed

Geber, Selmo; Bossi, Renata; Guimarães, Fernando; Valle, Marcello; Sampaio, Marcos

2012-10-01

Several culture media are available to be used in ART. However it is uncertain whether embryos would preferably benefit from one type of medium or the association of different media. We performed this study to evaluate the impact of simultaneous transfer of embryos independently cultured in two distinct culture media, on pregnancy outcome. A total of 722 couples who underwent infertility treatment were sequentially allocated into three groups: those who had half of the embryos individually cultured in MEM and the other half cultured in sequential media (MEM + Seq Group) (n = 243); those who had all embryos cultured only in sequential medium (Seq Group) (n = 239); and those who had all embryos cultured only in MEM (MEM Group) (n = 240). The pregnancy rate was higher in the MEM + Seq group (51.8 %) than the Seq group (36.7 %) (p < 0.001). However the pregnancy rate observed in the MEM group was similar to the others (44.2 %). When a logistic regression test was applied it demonstrated that the number of transferred embryos did not interfere in the pregnancy rates. Our results suggests that offering different culture conditions for sibling embryos with subsequent transfer of embryos that were kept in distinct culture media, might increase pregnancy rates in assisted reproduction cycles.

Reliability of chronic allograft nephropathy diagnosis in sequential protocol biopsies.

PubMed

Serón, Daniel; Moreso, Francesc; Fulladosa, Xavier; Hueso, Miguel; Carrera, Marta; Grinyó, Josep M

2002-02-01

Chronic allograft nephropathy (CAN) progresses rapidly during the first few months and slowly thereafter. Although the presence of CAN in protocol renal biopsies is a predictor of outcome, the reliability of this diagnosis according to Banff criteria has not been characterized. Renal lesions were evaluated according to the Banff criteria in sequential protocol biopsies performed at 4 and 14 months in 310 biopsies obtained from 155 patients. CAN progressed from 40 to 53% (P=0.001) while serum creatinine remained stable (146 +/- 44 vs. 147 +/- 48 micromol/L, P=NS). Graft survival in patients with and without CAN in the first biopsy was 74 versus 91% (P < 0.05), and in the second biopsy 75 versus 94% (P < 0.05). In 54 patients (35%) no CAN was present in both biopsies, 39 (25%) showed progression to CAN, 19 (12%) showed regression of CAN, and 43 (28%) showed CAN in both biopsies. Graft survival was: 100%, 81.6%, 82.6% and 69.4%, respectively (P < 0.01). Assuming that CAN does not regress and sampling error is normally distributed, we estimated that 25% of biopsies cannot be properly classified. The increase in the incidence of CAN between the 4th and 14th month is lower than the proportion of misclassified biopsies. Thus, monitoring the progression of CAN by means of two sequential biopsies at 4 and 14 months is inaccurate. We suggest that progression of scarring be monitored by means of a donor and a protocol biopsy performed during the first year evaluated with a quantitative approach.

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks

PubMed Central

Zhao, Rui; Yan, Ruqiang; Wang, Jinjiang; Mao, Kezhi

2017-01-01

In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM) has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks (LSTMs) are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods. PMID:28146106

Learning to Monitor Machine Health with Convolutional Bi-Directional LSTM Networks.

PubMed

Zhao, Rui; Yan, Ruqiang; Wang, Jinjiang; Mao, Kezhi

2017-01-30

In modern manufacturing systems and industries, more and more research efforts have been made in developing effective machine health monitoring systems. Among various machine health monitoring approaches, data-driven methods are gaining in popularity due to the development of advanced sensing and data analytic techniques. However, considering the noise, varying length and irregular sampling behind sensory data, this kind of sequential data cannot be fed into classification and regression models directly. Therefore, previous work focuses on feature extraction/fusion methods requiring expensive human labor and high quality expert knowledge. With the development of deep learning methods in the last few years, which redefine representation learning from raw data, a deep neural network structure named Convolutional Bi-directional Long Short-Term Memory networks (CBLSTM) has been designed here to address raw sensory data. CBLSTM firstly uses CNN to extract local features that are robust and informative from the sequential input. Then, bi-directional LSTM is introduced to encode temporal information. Long Short-Term Memory networks(LSTMs) are able to capture long-term dependencies and model sequential data, and the bi-directional structure enables the capture of past and future contexts. Stacked, fully-connected layers and the linear regression layer are built on top of bi-directional LSTMs to predict the target value. Here, a real-life tool wear test is introduced, and our proposed CBLSTM is able to predict the actual tool wear based on raw sensory data. The experimental results have shown that our model is able to outperform several state-of-the-art baseline methods.

Cyst-based measurements for assessing lymphangioleiomyomatosis in computed tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo, P., E-mail: pechinlo@mednet.edu.ucla; Brown, M. S.; Kim, H.

Purpose: To investigate the efficacy of a new family of measurements made on individual pulmonary cysts extracted from computed tomography (CT) for assessing the severity of lymphangioleiomyomatosis (LAM). Methods: CT images were analyzed using thresholding to identify a cystic region of interest from chest CT of LAM patients. Individual cysts were then extracted from the cystic region by the watershed algorithm, which separates individual cysts based on subtle edges within the cystic regions. A family of measurements were then computed, which quantify the amount, distribution, and boundary appearance of the cysts. Sequential floating feature selection was used to select amore » small subset of features for quantification of the severity of LAM. Adjusted R{sup 2} from multiple linear regression and R{sup 2} from linear regression against measurements from spirometry were used to compare the performance of our proposed measurements with currently used density based CT measurements in the literature, namely, the relative area measure and the D measure. Results: Volumetric CT data, performed at total lung capacity and residual volume, from a total of 49 subjects enrolled in the MILES trial were used in our study. Our proposed measures had adjusted R{sup 2} ranging from 0.42 to 0.59 when regressing against the spirometry measures, with p < 0.05. For previously used density based CT measurements in the literature, the best R{sup 2} was 0.46 (for only one instance), with the majority being lower than 0.3 or p > 0.05. Conclusions: The proposed family of CT-based cyst measurements have better correlation with spirometric measures than previously used density based CT measurements. They show potential as a sensitive tool for quantitatively assessing the severity of LAM.« less

Sequential glycan profiling at single cell level with the microfluidic lab-in-a-trench platform: a new era in experimental cell biology.

PubMed

O'Connell, Tríona M; King, Damien; Dixit, Chandra K; O'Connor, Brendan; Walls, Dermot; Ducrée, Jens

2014-09-21

It is now widely recognised that the earliest changes that occur on a cell when it is stressed or becoming diseased are alterations in its surface glycosylation. Current state-of-the-art technologies in glycoanalysis include mass spectrometry, protein microarray formats, techniques in cytometry and more recently, glyco-quantitative polymerase chain reaction (Glyco-qPCR). Techniques for the glycoprofiling of the surfaces of single cells are either limited to the analysis of large cell populations or are unable to handle multiple and/or sequential probing. Here, we report a novel approach of single live cell glycoprofiling enabled by the microfluidic "Lab-in-a-Trench" (LiaT) platform for performing capture and retention of cells, along with shear-free reagent loading and washing. The significant technical improvement on state-of-the-art is the demonstration of consecutive, spatio-temporally profiling of glycans on a single cell by sequential elution of the previous lectin probe using their corresponding free sugar. We have qualitatively analysed glycan density on the surface of individual cells. This has allowed us to qualitatively co-localise the observed glycans. This approach enables exhaustive glycoprofiling and glycan mapping on the surface of individual live cells with multiple lectins. The possibility of sequentially profiling glycans on cells will be a powerful new tool to add to current glycoanalytical techniques. The LiaT platform will enable cell biologists to perform many high sensitivity assays and also will also make a significant impact on biomarker research.

Automated microbial metabolism laboratory. [design of advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into test chambers

NASA Technical Reports Server (NTRS)

1974-01-01

The design and rationale of an advanced labeled release experiment based on single addition of soil and multiple sequential additions of media into each of four test chambers are outlined. The feasibility for multiple addition tests was established and various details of the methodology were studied. The four chamber battery of tests include: (1) determination of the effect of various atmospheric gases and selection of that gas which produces an optimum response; (2) determination of the effect of incubation temperature and selection of the optimum temperature for performing Martian biochemical tests; (3) sterile soil is dosed with a battery of C-14 labeled substrates and subjected to experimental temperature range; and (4) determination of the possible inhibitory effects of water on Martian organisms is performed initially by dosing with 0.01 ml and 0.5 ml of medium, respectively. A series of specifically labeled substrates are then added to obtain patterns in metabolic 14CO2 (C-14)O2 evolution.

Enhancing battery efficiency for pervasive health-monitoring systems based on electronic textiles.

PubMed

Zheng, Nenggan; Wu, Zhaohui; Lin, Man; Yang, Laurence Tianruo

2010-03-01

Electronic textiles are regarded as one of the most important computation platforms for future computer-assisted health-monitoring applications. In these novel systems, multiple batteries are used in order to prolong their operational lifetime, which is a significant metric for system usability. However, due to the nonlinear features of batteries, computing systems with multiple batteries cannot achieve the same battery efficiency as those powered by a monolithic battery of equal capacity. In this paper, we propose an algorithm aiming to maximize battery efficiency globally for the computer-assisted health-care systems with multiple batteries. Based on an accurate analytical battery model, the concept of weighted battery fatigue degree is introduced and the novel battery-scheduling algorithm called predicted weighted fatigue degree least first (PWFDLF) is developed. Besides, we also discuss our attempts during search PWFDLF: a weighted round-robin (WRR) and a greedy algorithm achieving highest local battery efficiency, which reduces to the sequential discharging policy. Evaluation results show that a considerable improvement in battery efficiency can be obtained by PWFDLF under various battery configurations and current profiles compared to conventional sequential and WRR discharging policies.

Multienzyme kinetics and sequential metabolism.

PubMed

Wienkers, Larry C; Rock, Brooke

2014-01-01

Enzymes are the catalysts of biological systems and are extremely efficient. A typical enzyme accelerates the rate of a reaction by factors of at least a million compared to the rate of the same reaction in the absence of the enzyme. In contrast to traditional catalytic enzymes, the family of cytochrome P450 (CYP) enzymes are catalytically promiscuous, and thus they possess remarkable versatility in substrates. The great diversity of reactions catalyzed by CYP enzymes appears to be based on two unique properties of these heme proteins, the ability of their iron to exist under multiple oxidation states with different reactivities and a flexible active site that can accommodate a wide variety of substrates. Herein is a discussion of two distinct types of kinetics observed with CYP enzymes. The first example is of CYP complex kinetic profiles when multiple CYP enzymes form the sample product. The second is sequential metabolism, in other words, the formation of multiple products from one CYP enzyme. Given the degree of CYP enzyme promiscuity, it is hardly surprising that there is also a high degree of complex kinetic profiles generated during the catalytic cycle.

Multiple-Instance Regression with Structured Data

NASA Technical Reports Server (NTRS)

Wagstaff, Kiri L.; Lane, Terran; Roper, Alex

2008-01-01

We present a multiple-instance regression algorithm that models internal bag structure to identify the items most relevant to the bag labels. Multiple-instance regression (MIR) operates on a set of bags with real-valued labels, each containing a set of unlabeled items, in which the relevance of each item to its bag label is unknown. The goal is to predict the labels of new bags from their contents. Unlike previous MIR methods, MI-ClusterRegress can operate on bags that are structured in that they contain items drawn from a number of distinct (but unknown) distributions. MI-ClusterRegress simultaneously learns a model of the bag's internal structure, the relevance of each item, and a regression model that accurately predicts labels for new bags. We evaluated this approach on the challenging MIR problem of crop yield prediction from remote sensing data. MI-ClusterRegress provided predictions that were more accurate than those obtained with non-multiple-instance approaches or MIR methods that do not model the bag structure.

Polymeric micelles for multi-drug delivery in cancer.

PubMed

Cho, Hyunah; Lai, Tsz Chung; Tomoda, Keishiro; Kwon, Glen S

2015-02-01

Drug combinations are common in cancer treatment and are rapidly evolving, moving beyond chemotherapy combinations to combinations of signal transduction inhibitors. For the delivery of drug combinations, i.e., multi-drug delivery, major considerations are synergy, dose regimen (concurrent versus sequential), pharmacokinetics, toxicity, and safety. In this contribution, we review recent research on polymeric micelles for multi-drug delivery in cancer. In concurrent drug delivery, polymeric micelles deliver multi-poorly water-soluble anticancer agents, satisfying strict requirements in solubility, stability, and safety. In sequential drug delivery, polymeric micelles participate in pretreatment strategies that "prime" solid tumors and enhance the penetration of secondarily administered anticancer agent or nanocarrier. The improved delivery of multiple poorly water-soluble anticancer agents by polymeric micelles via concurrent or sequential regimens offers novel and interesting strategies for drug combinations in cancer treatment.

Spatiotemporally and Sequentially-Controlled Drug Release from Polymer Gatekeeper-Hollow Silica Nanoparticles

NASA Astrophysics Data System (ADS)

Palanikumar, L.; Jeena, M. T.; Kim, Kibeom; Yong Oh, Jun; Kim, Chaekyu; Park, Myoung-Hwan; Ryu, Ja-Hyoung

2017-04-01

Combination chemotherapy has become the primary strategy against cancer multidrug resistance; however, accomplishing optimal pharmacokinetic delivery of multiple drugs is still challenging. Herein, we report a sequential combination drug delivery strategy exploiting a pH-triggerable and redox switch to release cargos from hollow silica nanoparticles in a spatiotemporal manner. This versatile system further enables a large loading efficiency for both hydrophobic and hydrophilic drugs inside the nanoparticles, followed by self-crosslinking with disulfide and diisopropylamine-functionalized polymers. In acidic tumour environments, the positive charge generated by the protonation of the diisopropylamine moiety facilitated the cellular uptake of the particles. Upon internalization, the acidic endosomal pH condition and intracellular glutathione regulated the sequential release of the drugs in a time-dependent manner, providing a promising therapeutic approach to overcoming drug resistance during cancer treatment.

The Domino Way to Heterocycles

PubMed Central

Padwa, Albert; Bur, Scott K.

2007-01-01

Sequential transformations enable the facile synthesis of complex target molecules from simple building blocks in a single preparative step. Their value is amplified if they also create multiple stereogenic centers. In the ongoing search for new domino processes, emphasis is usually placed on sequential reactions which occur cleanly and without forming by-products. As a prerequisite for an ideally proceeding one-pot sequential transformation, the reactivity pattern of all participating components has to be such that each building block gets involved in a reaction only when it is supposed to do so. The development of sequences that combine transformations of fundamentally different mechanisms broadens the scope of such procedures in synthetic chemistry. This mini review contains a representative sampling from the last 15 years on the kinds of reactions that have been sequenced into cascades to produce heterocyclic molecules. PMID:17940591

A Bayesian approach to tracking patients having changing pharmacokinetic parameters

NASA Technical Reports Server (NTRS)

Bayard, David S.; Jelliffe, Roger W.

2004-01-01

This paper considers the updating of Bayesian posterior densities for pharmacokinetic models associated with patients having changing parameter values. For estimation purposes it is proposed to use the Interacting Multiple Model (IMM) estimation algorithm, which is currently a popular algorithm in the aerospace community for tracking maneuvering targets. The IMM algorithm is described, and compared to the multiple model (MM) and Maximum A-Posteriori (MAP) Bayesian estimation methods, which are presently used for posterior updating when pharmacokinetic parameters do not change. Both the MM and MAP Bayesian estimation methods are used in their sequential forms, to facilitate tracking of changing parameters. Results indicate that the IMM algorithm is well suited for tracking time-varying pharmacokinetic parameters in acutely ill and unstable patients, incurring only about half of the integrated error compared to the sequential MM and MAP methods on the same example.

Association between prolonged breast-feeding and early childhood caries: a hierarchical approach.

PubMed

Nunes, Ana Margarida Melo; Alves, Claudia Maria Coelho; Borba de Araújo, Fernando; Ortiz, Tânia Mara Lopes; Ribeiro, Marizélia Rodrigues Costa; Silva, Antônio Augusto Moura da; Ribeiro, Cecília Claudia Costa

2012-12-01

This study was conducted to investigate the association between prolonged breastfeeding and early childhood caries(ECC) with adjustment for important confounders, using hieraschical approach. This retrospective cohort study involved 260 low-income children (18-42 months). The number of decayed teeth was used as a measure of caries. Following a theoretical framework, the hierarchical model was built in a forward fashion, by adding the following levels in succession: level 1: age; level 2: social variables; level 3: health variables; level 4: behavioral variables; level 5: oral hygiene-related variables; level 6: oral hygiene quality measured by visible plaque; and level 7: contamination by mutans streptococci. Sequential forward multiple Poisson regression analysis was employed. Breast-feeding was not a risk factor for ECC after adjustment for some confounders (incidence density ratio, 1.15; 95% confidence interval, 0.84-1.59, P = 0.363). Prolonged breast-feeding was not a risk factor for ECC while age, high sucrose comption between main meals and the quality of oral higiene were associated with disease in children. © 2012 John Wiley & Sons A/S.

Structural profiling of individual glycosphingolipids in a single thin-layer chromatogram by multiple sequential immunodetection matched with Direct IR-MALDI-o-TOF mass spectrometry.

PubMed

Souady, Jamal; Soltwisch, Jens; Dreisewerd, Klaus; Haier, Jörg; Peter-Katalinić, Jasna; Müthing, Johannes

2009-11-15

The thin-layer chromatography (TLC) immunoenzyme overlay assay is a widely used tool for antibody-mediated identification of glycosphingolipids (GSLs) in mixtures. However, because the majority of GSLs is left unexamined in a chromatogram of a single assay, we developed a novel method that permits detection of various GSLs by sequential multiple immunostaining combined with individual coloring of GSLs in the same chromatogram. Specific staining was achieved by means of primary anti-GSL antibodies, directed against lactosylceramide, globotriaosylceramide, and globotetraosylceramide, in conjunction with alkaline phosphatase (AP)- or horseradish peroxidase (HRP)-conjugated secondary antibodies together with the appropriate chromogenic substrates. Triple coloring with 5-bromo-4-chloro-3-indolyl phosphate (BCIP)-AP, Fast Red-AP, and 3,3'-diaminobenzidine (DAB)-HRP resulted in blue, red, and black precipitates, respectively, following three sequential immunostaining rounds. Structures of antibody-detected GSLs were determined by direct coupling of TLC with infrared matrix-assisted laser desorption/ionization orthogonal time-of-flight mass spectrometry. This combinatorial technique was used to demonstrate structural GSL profiling of crude lipid extracts from human hepatocellular cancer. This powerful technology allows efficient structural characterization of GSLs in small tissue samples and marks a further step forward in the emerging field of glycosphingolipidomics.

"Maxillary lateral incisor partial anodontia sequence": a clinical entity with epigenetic origin.

PubMed

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a "syndrome". Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called "Maxillary Lateral Incisor Partial Anodontia Sequence."

“Maxillary lateral incisor partial anodontia sequence”: a clinical entity with epigenetic origin

PubMed Central

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

ABSTRACT The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a “syndrome”. Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called “Maxillary Lateral Incisor Partial Anodontia Sequence.” PMID:29364376

Sequential Exposure of Bortezomib and Vorinostat is Synergistic in Multiple Myeloma Cells

PubMed Central

Nanavati, Charvi; Mager, Donald E.

2018-01-01

Purpose To examine the combination of bortezomib and vorinostat in multiple myeloma cells (U266) and xenografts, and to assess the nature of their potential interactions with semi-mechanistic pharmacodynamic models and biomarkers. Methods U266 proliferation was examined for a range of bortezomib and vorinostat exposure times and concentrations (alone and in combination). A non-competitive interaction model was used with interaction parameters that reflect the nature of drug interactions after simultaneous and sequential exposures. p21 and cleaved PARP were measured using immunoblotting to assess critical biomarker dynamics. For xenografts, data were extracted from literature and modeled with a PK/PD model with an interaction parameter. Results Estimated model parameters for simultaneous in vitro and xenograft treatments suggested additive drug effects. The sequence of bortezomib preincubation for 24 hours, followed by vorinostat for 24 hours, resulted in an estimated interaction term significantly less than 1, suggesting synergistic effects. p21 and cleaved PARP were also up-regulated the most in this sequence. Conclusions Semi-mechanistic pharmacodynamic modeling suggests synergistic pharmacodynamic interactions for the sequential administration of bortezomib followed by vorinostat. Increased p21 and cleaved PARP expression can potentially explain mechanisms of their enhanced effects, which require further PK/PD systems analysis to suggest an optimal dosing regimen. PMID:28101809

Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

ERIC Educational Resources Information Center

Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

2010-01-01

The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

Time-resolved non-sequential ray-tracing modelling of non-line-of-sight picosecond pulse LIDAR

NASA Astrophysics Data System (ADS)

Sroka, Adam; Chan, Susan; Warburton, Ryan; Gariepy, Genevieve; Henderson, Robert; Leach, Jonathan; Faccio, Daniele; Lee, Stephen T.

2016-05-01

The ability to detect motion and to track a moving object that is hidden around a corner or behind a wall provides a crucial advantage when physically going around the obstacle is impossible or dangerous. One recently demonstrated approach to achieving this goal makes use of non-line-of-sight picosecond pulse laser ranging. This approach has recently become interesting due to the availability of single-photon avalanche diode (SPAD) receivers with picosecond time resolution. We present a time-resolved non-sequential ray-tracing model and its application to indirect line-of-sight detection of moving targets. The model makes use of the Zemax optical design programme's capabilities in stray light analysis where it traces large numbers of rays through multiple random scattering events in a 3D non-sequential environment. Our model then reconstructs the generated multi-segment ray paths and adds temporal analysis. Validation of this model against experimental results is shown. We then exercise the model to explore the limits placed on system design by available laser sources and detectors. In particular we detail the requirements on the laser's pulse energy, duration and repetition rate, and on the receiver's temporal response and sensitivity. These are discussed in terms of the resulting implications for achievable range, resolution and measurement time while retaining eye-safety with this technique. Finally, the model is used to examine potential extensions to the experimental system that may allow for increased localisation of the position of the detected moving object, such as the inclusion of multiple detectors and/or multiple emitters.

Comparison of Statistical Approaches Dealing with Time-dependent Confounding in Drug Effectiveness Studies

PubMed Central

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W.; Tremlett, Helen

2017-01-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models (MSCMs) are frequently used to deal with such confounding. To avoid some of the problems of fitting MSCM, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as MSCM in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995 – 2008). PMID:27659168

Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies.

PubMed

Karim, Mohammad Ehsanul; Petkau, John; Gustafson, Paul; Platt, Robert W; Tremlett, Helen

2018-06-01

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

Sequential strand displacement beacon for detection of DNA coverage on functionalized gold nanoparticles.

PubMed

Paliwoda, Rebecca E; Li, Feng; Reid, Michael S; Lin, Yanwen; Le, X Chris

2014-06-17

Functionalizing nanomaterials for diverse analytical, biomedical, and therapeutic applications requires determination of surface coverage (or density) of DNA on nanomaterials. We describe a sequential strand displacement beacon assay that is able to quantify specific DNA sequences conjugated or coconjugated onto gold nanoparticles (AuNPs). Unlike the conventional fluorescence assay that requires the target DNA to be fluorescently labeled, the sequential strand displacement beacon method is able to quantify multiple unlabeled DNA oligonucleotides using a single (universal) strand displacement beacon. This unique feature is achieved by introducing two short unlabeled DNA probes for each specific DNA sequence and by performing sequential DNA strand displacement reactions. Varying the relative amounts of the specific DNA sequences and spacing DNA sequences during their coconjugation onto AuNPs results in different densities of the specific DNA on AuNP, ranging from 90 to 230 DNA molecules per AuNP. Results obtained from our sequential strand displacement beacon assay are consistent with those obtained from the conventional fluorescence assays. However, labeling of DNA with some fluorescent dyes, e.g., tetramethylrhodamine, alters DNA density on AuNP. The strand displacement strategy overcomes this problem by obviating direct labeling of the target DNA. This method has broad potential to facilitate more efficient design and characterization of novel multifunctional materials for diverse applications.

Structural and Functional Impacts of ER Coactivator Sequential Recruitment.

PubMed

Yi, Ping; Wang, Zhao; Feng, Qin; Chou, Chao-Kai; Pintilie, Grigore D; Shen, Hong; Foulds, Charles E; Fan, Guizhen; Serysheva, Irina; Ludtke, Steven J; Schmid, Michael F; Hung, Mien-Chie; Chiu, Wah; O'Malley, Bert W

2017-09-07

Nuclear receptors recruit multiple coactivators sequentially to activate transcription. This "ordered" recruitment allows different coactivator activities to engage the nuclear receptor complex at different steps of transcription. Estrogen receptor (ER) recruits steroid receptor coactivator-3 (SRC-3) primary coactivator and secondary coactivators, p300/CBP and CARM1. CARM1 recruitment lags behind the binding of SRC-3 and p300 to ER. Combining cryo-electron microscopy (cryo-EM) structure analysis and biochemical approaches, we demonstrate that there is a close crosstalk between early- and late-recruited coactivators. The sequential recruitment of CARM1 not only adds a protein arginine methyltransferase activity to the ER-coactivator complex, it also alters the structural organization of the pre-existing ERE/ERα/SRC-3/p300 complex. It induces a p300 conformational change and significantly increases p300 HAT activity on histone H3K18 residues, which, in turn, promotes CARM1 methylation activity on H3R17 residues to enhance transcriptional activity. This study reveals a structural role for a coactivator sequential recruitment and biochemical process in ER-mediated transcription. Copyright © 2017 Elsevier Inc. All rights reserved.

Adaptive x-ray threat detection using sequential hypotheses testing with fan-beam experimental data (Conference Presentation)

NASA Astrophysics Data System (ADS)

Thamvichai, Ratchaneekorn; Huang, Liang-Chih; Ashok, Amit; Gong, Qian; Coccarelli, David; Greenberg, Joel A.; Gehm, Michael E.; Neifeld, Mark A.

2017-05-01

We employ an adaptive measurement system, based on sequential hypotheses testing (SHT) framework, for detecting material-based threats using experimental data acquired on an X-ray experimental testbed system. This testbed employs 45-degree fan-beam geometry and 15 views over a 180-degree span to generate energy sensitive X-ray projection data. Using this testbed system, we acquire multiple view projection data for 200 bags. We consider an adaptive measurement design where the X-ray projection measurements are acquired in a sequential manner and the adaptation occurs through the choice of the optimal "next" source/view system parameter. Our analysis of such an adaptive measurement design using the experimental data demonstrates a 3x-7x reduction in the probability of error relative to a static measurement design. Here the static measurement design refers to the operational system baseline that corresponds to a sequential measurement using all the available sources/views. We also show that by using adaptive measurements it is possible to reduce the number of sources/views by nearly 50% compared a system that relies on static measurements.

Multiple acquisitions via sequential transfer of orphan spin polarization (MAeSTOSO): How far can we push residual spin polarization in solid-state NMR?

NASA Astrophysics Data System (ADS)

Gopinath, T.; Veglia, Gianluigi

2016-06-01

Conventional multidimensional magic angle spinning (MAS) solid-state NMR (ssNMR) experiments detect the signal arising from the decay of a single coherence transfer pathway (FID), resulting in one spectrum per acquisition time. Recently, we introduced two new strategies, namely DUMAS (DUal acquisition Magic Angle Spinning) and MEIOSIS (Multiple ExperIments via Orphan SpIn operatorS), that enable the simultaneous acquisitions of multidimensional ssNMR experiments using multiple coherence transfer pathways. Here, we combined the main elements of DUMAS and MEIOSIS to harness both orphan spin operators and residual polarization and increase the number of simultaneous acquisitions. We show that it is possible to acquire up to eight two-dimensional experiments using four acquisition periods per each scan. This new suite of pulse sequences, called MAeSTOSO for Multiple Acquisitions via Sequential Transfer of Orphan Spin pOlarization, relies on residual polarization of both 13C and 15N pathways and combines low- and high-sensitivity experiments into a single pulse sequence using one receiver and commercial ssNMR probes. The acquisition of multiple experiments does not affect the sensitivity of the main experiment; rather it recovers the lost coherences that are discarded, resulting in a significant gain in experimental time. Both merits and limitations of this approach are discussed.

Multiple magnet ingestion: is there a role for early surgical intervention?

PubMed

Salimi, Amrollah; Kooraki, Soheil; Esfahani, Shadi Abdar; Mehdizadeh, Mehrzad

2012-01-01

Children often swallow foreign bodies. Multiple magnet ingestion is rare, but can result in serious complications. This study presents three unique cases of multiple magnet ingestion: one case an 8-year-old boy with multiple magnet ingestion resulting in gastric obstruction and the other two cases with intestinal perforations due to multiple magnet intake. History and physical examination are unreliable in children who swallow multiple magnets. Sometimes radiological findings are not conclusive, whether one magnet is swallowed or more. If magnets are not moved in sequential radiology images, we recommend early surgical intervention before gastrointestinal complications develop. Toy companies, parents, physicians, and radiologists should be warned about the potential complications of such toys.

Computer retrieval of bibliographies using an editing program

USGS Publications Warehouse

Brethauer, G.E.; Brokaw, V.L.

1979-01-01

A simple program permits use of the text .editor 'qedx,' part of many computer systems, to input bibliographic entries and to retrieve specific entries which contain keywords of interest. Multiple keywords may be used sequentially to find specific entries.

Particle filters, a quasi-Monte-Carlo-solution for segmentation of coronaries.

PubMed

Florin, Charles; Paragios, Nikos; Williams, Jim

2005-01-01

In this paper we propose a Particle Filter-based approach for the segmentation of coronary arteries. To this end, successive planes of the vessel are modeled as unknown states of a sequential process. Such states consist of the orientation, position, shape model and appearance (in statistical terms) of the vessel that are recovered in an incremental fashion, using a sequential Bayesian filter (Particle Filter). In order to account for bifurcations and branchings, we consider a Monte Carlo sampling rule that propagates in parallel multiple hypotheses. Promising results on the segmentation of coronary arteries demonstrate the potential of the proposed approach.

A Quantile Regression Approach to Understanding the Relations Between Morphological Awareness, Vocabulary, and Reading Comprehension in Adult Basic Education Students

PubMed Central

Tighe, Elizabeth L.; Schatschneider, Christopher

2015-01-01

The purpose of this study was to investigate the joint and unique contributions of morphological awareness and vocabulary knowledge at five reading comprehension levels in Adult Basic Education (ABE) students. We introduce the statistical technique of multiple quantile regression, which enabled us to assess the predictive utility of morphological awareness and vocabulary knowledge at multiple points (quantiles) along the continuous distribution of reading comprehension. To demonstrate the efficacy of our multiple quantile regression analysis, we compared and contrasted our results with a traditional multiple regression analytic approach. Our results indicated that morphological awareness and vocabulary knowledge accounted for a large portion of the variance (82-95%) in reading comprehension skills across all quantiles. Morphological awareness exhibited the greatest unique predictive ability at lower levels of reading comprehension whereas vocabulary knowledge exhibited the greatest unique predictive ability at higher levels of reading comprehension. These results indicate the utility of using multiple quantile regression to assess trajectories of component skills across multiple levels of reading comprehension. The implications of our findings for ABE programs are discussed. PMID:25351773

ℓ(p)-Norm multikernel learning approach for stock market price forecasting.

PubMed

Shao, Xigao; Wu, Kun; Liao, Bifeng

2012-01-01

Linear multiple kernel learning model has been used for predicting financial time series. However, ℓ(1)-norm multiple support vector regression is rarely observed to outperform trivial baselines in practical applications. To allow for robust kernel mixtures that generalize well, we adopt ℓ(p)-norm multiple kernel support vector regression (1 ≤ p < ∞) as a stock price prediction model. The optimization problem is decomposed into smaller subproblems, and the interleaved optimization strategy is employed to solve the regression model. The model is evaluated on forecasting the daily stock closing prices of Shanghai Stock Index in China. Experimental results show that our proposed model performs better than ℓ(1)-norm multiple support vector regression model.

Sequential voluntary cough and aspiration or aspiration risk in Parkinson's disease.

PubMed

Hegland, Karen Wheeler; Okun, Michael S; Troche, Michelle S

2014-08-01

Disordered swallowing, or dysphagia, is almost always present to some degree in people with Parkinson's disease (PD), either causing aspiration or greatly increasing the risk for aspiration during swallowing. This likely contributes to aspiration pneumonia, a leading cause of death in this patient population. Effective airway protection is dependent upon multiple behaviors, including cough and swallowing. Single voluntary cough function is disordered in people with PD and dysphagia. However, the appropriate response to aspirate material is more than one cough, or sequential cough. The goal of this study was to examine voluntary sequential coughing in people with PD, with and without dysphagia. Forty adults diagnosed with idiopathic PD produced two trials of sequential voluntary cough. The cough airflows were obtained using pneumotachograph and facemask and subsequently digitized and recorded. All participants received a modified barium swallow study as part of their clinical care, and the worst penetration-aspiration score observed was used to determine whether the patient had dysphagia. There were significant differences in the compression phase duration, peak expiratory flow rates, and amount of air expired of the sequential cough produced by participants with and without dysphagia. The presence of dysphagia in people with PD is associated with disordered cough function. Sequential cough, which is important in removing aspirate material from large- and smaller-diameter airways, is also impaired in people with PD and dysphagia compared with those without dysphagia. There may be common neuroanatomical substrates for cough and swallowing impairment in PD leading to the co-occurrence of these dysfunctions.

Costs of achieving live birth from assisted reproductive technology: a comparison of sequential single and double embryo transfer approaches.

PubMed

Crawford, Sara; Boulet, Sheree L; Mneimneh, Allison S; Perkins, Kiran M; Jamieson, Denise J; Zhang, Yujia; Kissin, Dmitry M

2016-02-01

To assess treatment and pregnancy/infant-associated medical costs and birth outcomes for assisted reproductive technology (ART) cycles in a subset of patients using elective double embryo (ET) and to project the difference in costs and outcomes had the cycles instead been sequential single ETs (fresh followed by frozen if the fresh ET did not result in live birth). Retrospective cohort study using 2012 and 2013 data from the National ART Surveillance System. Infertility treatment centers. Fresh, autologous double ETs performed in 2012 among ART patients younger than 35 years of age with no prior ART use who cryopreserved at least one embryo. Sequential single and double ETs. Actual live birth rates and estimated ART treatment and pregnancy/infant-associated medical costs for double ET cycles started in 2012 and projected ART treatment and pregnancy/infant-associated medical costs if the double ET cycles had been performed as sequential single ETs. The estimated total ART treatment and pregnancy/infant-associated medical costs were $580.9 million for 10,001 double ETs started in 2012. If performed as sequential single ETs, estimated costs would have decreased by $195.0 million to $386.0 million, and live birth rates would have increased from 57.7%-68.0%. Sequential single ETs, when clinically appropriate, can reduce total ART treatment and pregnancy/infant-associated medical costs by reducing multiple births without lowering live birth rates. Published by Elsevier Inc.

River velocities from sequential multispectral remote sensing images

NASA Astrophysics Data System (ADS)

Chen, Wei; Mied, Richard P.

2013-06-01

We address the problem of extracting surface velocities from a pair of multispectral remote sensing images over rivers using a new nonlinear multiple-tracer form of the global optimal solution (GOS). The derived velocity field is a valid solution across the image domain to the nonlinear system of equations obtained by minimizing a cost function inferred from the conservation constraint equations for multiple tracers. This is done by deriving an iteration equation for the velocity, based on the multiple-tracer displaced frame difference equations, and a local approximation to the velocity field. The number of velocity equations is greater than the number of velocity components, and thus overly constrain the solution. The iterative technique uses Gauss-Newton and Levenberg-Marquardt methods and our own algorithm of the progressive relaxation of the over-constraint. We demonstrate the nonlinear multiple-tracer GOS technique with sequential multispectral Landsat and ASTER images over a portion of the Potomac River in MD/VA, and derive a dense field of accurate velocity vectors. We compare the GOS river velocities with those from over 12 years of data at four NOAA reference stations, and find good agreement. We discuss how to find the appropriate spatial and temporal resolutions to allow optimization of the technique for specific rivers.

Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform

PubMed Central

Lim, Pooi Khoon; Ng, Siew-Cheok; Jassim, Wissam A.; Redmond, Stephen J.; Zilany, Mohammad; Avolio, Alberto; Lim, Einly; Tan, Maw Pin; Lovell, Nigel H.

2015-01-01

We present a novel approach to improve the estimation of systolic (SBP) and diastolic blood pressure (DBP) from oscillometric waveform data using variable characteristic ratios between SBP and DBP with mean arterial pressure (MAP). This was verified in 25 healthy subjects, aged 28 ± 5 years. The multiple linear regression (MLR) and support vector regression (SVR) models were used to examine the relationship between the SBP and the DBP ratio with ten features extracted from the oscillometric waveform envelope (OWE). An automatic algorithm based on relative changes in the cuff pressure and neighbouring oscillometric pulses was proposed to remove outlier points caused by movement artifacts. Substantial reduction in the mean and standard deviation of the blood pressure estimation errors were obtained upon artifact removal. Using the sequential forward floating selection (SFFS) approach, we were able to achieve a significant reduction in the mean and standard deviation of differences between the estimated SBP values and the reference scoring (MLR: mean ± SD = −0.3 ± 5.8 mmHg; SVR and −0.6 ± 5.4 mmHg) with only two features, i.e., Ratio2 and Area3, as compared to the conventional maximum amplitude algorithm (MAA) method (mean ± SD = −1.6 ± 8.6 mmHg). Comparing the performance of both MLR and SVR models, our results showed that the MLR model was able to achieve comparable performance to that of the SVR model despite its simplicity. PMID:26087370

The influence of self-efficacy and outcome expectations on the relationship between perceived environment and physical activity in the workplace

PubMed Central

Prodaniuk, Tricia R; Plotnikoff, Ronald C; Spence, John C; Wilson, Phillip M

2004-01-01

Background Recent research and commentary contends that ecological approaches may be particularly useful for understanding and promoting physical activity participation in various settings including the workplace. Yet within the physical activity domain there is a lack of understanding of how ecological environment factors influence behaviour. Thus, the purpose of this study was to examine the relationships between perceived environment, social-cognitive variables, and physical activity behaviour. Methods Participants (N = 897) were employees from three large worksites who completed self-report inventories containing measures of self-efficacy, outcome expectations, perceptions of the workplace environment (PWES), and physical activity behaviour during both leisure-time and incorporated throughout the workday. Results Results of both bivariate and multiple regression analyses indicated the global PWES scores had a limited association with leisure-time physical activity (R2adj =.01). Sequential regression analyses supported a weak association between physical activity incorporated in the workplace and PWES (R2adj = .04) and the partial mediation of self-efficacy on the relationship between PWES and workplace physical activity (variance accounted for reduced to R2adj = .02 when self-efficacy was controlled). Conclusion Overall, the results of the present investigation indicate that self-efficacy acted as a partial mediator of the relationship between perceived environment and workplace physical activity participation. Implications of the findings for physical activity promotion using ecological-based approaches, and future directions for research from this perspective in worksite settings are discussed. PMID:15169560

Advanced statistics: linear regression, part II: multiple linear regression.

PubMed

Marill, Keith A

2004-01-01

The applications of simple linear regression in medical research are limited, because in most situations, there are multiple relevant predictor variables. Univariate statistical techniques such as simple linear regression use a single predictor variable, and they often may be mathematically correct but clinically misleading. Multiple linear regression is a mathematical technique used to model the relationship between multiple independent predictor variables and a single dependent outcome variable. It is used in medical research to model observational data, as well as in diagnostic and therapeutic studies in which the outcome is dependent on more than one factor. Although the technique generally is limited to data that can be expressed with a linear function, it benefits from a well-developed mathematical framework that yields unique solutions and exact confidence intervals for regression coefficients. Building on Part I of this series, this article acquaints the reader with some of the important concepts in multiple regression analysis. These include multicollinearity, interaction effects, and an expansion of the discussion of inference testing, leverage, and variable transformations to multivariate models. Examples from the first article in this series are expanded on using a primarily graphic, rather than mathematical, approach. The importance of the relationships among the predictor variables and the dependence of the multivariate model coefficients on the choice of these variables are stressed. Finally, concepts in regression model building are discussed.

Modeling Polytomous Item Responses Using Simultaneously Estimated Multinomial Logistic Regression Models

ERIC Educational Resources Information Center

Anderson, Carolyn J.; Verkuilen, Jay; Peyton, Buddy L.

2010-01-01

Survey items with multiple response categories and multiple-choice test questions are ubiquitous in psychological and educational research. We illustrate the use of log-multiplicative association (LMA) models that are extensions of the well-known multinomial logistic regression model for multiple dependent outcome variables to reanalyze a set of…

SIMPLE: a sequential immunoperoxidase labeling and erasing method.

PubMed

Glass, George; Papin, Jason A; Mandell, James W

2009-10-01

The ability to simultaneously visualize expression of multiple antigens in cells and tissues can provide powerful insights into cellular and organismal biology. However, standard methods are limited to the use of just two or three simultaneous probes and have not been widely adopted for routine use in paraffin-embedded tissue. We have developed a novel approach called sequential immunoperoxidase labeling and erasing (SIMPLE) that enables the simultaneous visualization of at least five markers within a single tissue section. Utilizing the alcohol-soluble peroxidase substrate 3-amino-9-ethylcarbazole, combined with a rapid non-destructive method for antibody-antigen dissociation, we demonstrate the ability to erase the results of a single immunohistochemical stain while preserving tissue antigenicity for repeated rounds of labeling. SIMPLE is greatly facilitated by the use of a whole-slide scanner, which can capture the results of each sequential stain without any information loss.

Learning multiple variable-speed sequences in striatum via cortical tutoring.

PubMed

Murray, James M; Escola, G Sean

2017-05-08

Sparse, sequential patterns of neural activity have been observed in numerous brain areas during timekeeping and motor sequence tasks. Inspired by such observations, we construct a model of the striatum, an all-inhibitory circuit where sequential activity patterns are prominent, addressing the following key challenges: (i) obtaining control over temporal rescaling of the sequence speed, with the ability to generalize to new speeds; (ii) facilitating flexible expression of distinct sequences via selective activation, concatenation, and recycling of specific subsequences; and (iii) enabling the biologically plausible learning of sequences, consistent with the decoupling of learning and execution suggested by lesion studies showing that cortical circuits are necessary for learning, but that subcortical circuits are sufficient to drive learned behaviors. The same mechanisms that we describe can also be applied to circuits with both excitatory and inhibitory populations, and hence may underlie general features of sequential neural activity pattern generation in the brain.

Effective Identification of Similar Patients Through Sequential Matching over ICD Code Embedding.

PubMed

Nguyen, Dang; Luo, Wei; Venkatesh, Svetha; Phung, Dinh

2018-04-11

Evidence-based medicine often involves the identification of patients with similar conditions, which are often captured in ICD (International Classification of Diseases (World Health Organization 2013)) code sequences. With no satisfying prior solutions for matching ICD-10 code sequences, this paper presents a method which effectively captures the clinical similarity among routine patients who have multiple comorbidities and complex care needs. Our method leverages the recent progress in representation learning of individual ICD-10 codes, and it explicitly uses the sequential order of codes for matching. Empirical evaluation on a state-wide cancer data collection shows that our proposed method achieves significantly higher matching performance compared with state-of-the-art methods ignoring the sequential order. Our method better identifies similar patients in a number of clinical outcomes including readmission and mortality outlook. Although this paper focuses on ICD-10 diagnosis code sequences, our method can be adapted to work with other codified sequence data.

Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis

PubMed Central

Peng, Shu; Pan, Yu‐Chen; Wang, Yaling; Xu, Zhe; Chen, Chao

2017-01-01

Abstract The introduction of controlled self‐assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme‐activated examples reported before, controlled self‐assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self‐assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof‐of‐principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis‐inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal‐to‐noise ratio. PMID:29201625

Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis.

PubMed

Peng, Shu; Pan, Yu-Chen; Wang, Yaling; Xu, Zhe; Chen, Chao; Ding, Dan; Wang, Yongjian; Guo, Dong-Sheng

2017-11-01

The introduction of controlled self-assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme-activated examples reported before, controlled self-assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self-assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof-of-principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis-inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal-to-noise ratio.

Regeneration of glass nanofluidic chips through a multiple-step sequential thermochemical decomposition process at high temperatures.

PubMed

Xu, Yan; Wu, Qian; Shimatani, Yuji; Yamaguchi, Koji

2015-10-07

Due to the lack of regeneration methods, the reusability of nanofluidic chips is a significant technical challenge impeding the efficient and economic promotion of both fundamental research and practical applications on nanofluidics. Herein, a simple method for the total regeneration of glass nanofluidic chips was described. The method consists of sequential thermal treatment with six well-designed steps, which correspond to four sequential thermal and thermochemical decomposition processes, namely, dehydration, high-temperature redox chemical reaction, high-temperature gasification, and cooling. The method enabled the total regeneration of typical 'dead' glass nanofluidic chips by eliminating physically clogged nanoparticles in the nanochannels, removing chemically reacted organic matter on the glass surface and regenerating permanent functional surfaces of dissimilar materials localized in the nanochannels. The method provides a technical solution to significantly improve the reusability of glass nanofluidic chips and will be useful for the promotion and acceleration of research and applications on nanofluidics.

Sequential Injection Analysis for Optimization of Molecular Biology Reactions

PubMed Central

Allen, Peter B.; Ellington, Andrew D.

2011-01-01

In order to automate the optimization of complex biochemical and molecular biology reactions, we developed a Sequential Injection Analysis (SIA) device and combined this with a Design of Experiment (DOE) algorithm. This combination of hardware and software automatically explores the parameter space of the reaction and provides continuous feedback for optimizing reaction conditions. As an example, we optimized the endonuclease digest of a fluorogenic substrate, and showed that the optimized reaction conditions also applied to the digest of the substrate outside of the device, and to the digest of a plasmid. The sequential technique quickly arrived at optimized reaction conditions with less reagent use than a batch process (such as a fluid handling robot exploring multiple reaction conditions in parallel) would have. The device and method should now be amenable to much more complex molecular biology reactions whose variable spaces are correspondingly larger. PMID:21338059

Enhancing lineup identification accuracy: two codes are better than one.

PubMed

Melara, R D; DeWitt-Rickards, T S; O'Brien, T P

1989-10-01

Ways of improving identification accuracy were explored by comparing the conventional visual lineup with an auditory/visual lineup, one that paired color photographs with voice recordings. This bimodal lineup necessitated sequential presentation of lineup members; Experiment 1 showed that performance in sequential lineups was better than performance in traditional simultaneous lineups. In Experiments 2A and 2B unimodal and bimodal lineups were compared by using a multiple-lineup paradigm: Ss viewed 3 videotaped episodes depicting standard police procedures and were tested in 4 sequential lineups. Bimodal lineups were more diagnostic than either visual or auditory lineups alone. The bimodal lineup led to a 126% improvement in number of correct identifications over the conventional visual lineup, with no concomitant increase in number of false identifications. These results imply strongly that bimodal procedures should be adopted in real-world lineups. The nature of memorial processes underlying this bimodal advantage is discussed.

Reducing sedation time for thyroplasty with arytenoid adduction with sequential anesthetic technique.

PubMed

Saadeh, Charles K; Rosero, Eric B; Joshi, Girish P; Ozayar, Esra; Mau, Ted

2017-12-01

To determine the extent to which a sequential anesthetic technique 1) shortens time under sedation for thyroplasty with arytenoid adduction (TP-AA), 2) affects the total operative time, and 3) changes the voice outcome compared to TP-AA performed entirely under sedation/analgesia. Case-control study. A new sequential anesthetic technique of performing most of the TP-AA surgery under general anesthesia (GA), followed by transition to sedation/analgesia (SA) for voice assessment, was developed to achieve smooth emergence from GA. Twenty-five TP-AA cases performed with the sequential GA-SA technique were compared with 25 TP-AA controls performed completely under sedation/analgesia. The primary outcome measure was the time under sedation. Voice improvement, as assessed by Consensus Auditory-Perceptual Evaluation of Voice, and total operative time were secondary outcome measures. With the conventional all-SA anesthetic, the duration of SA was 209 ± 26.3 minutes. With the sequential GA-SA technique, the duration of SA was 79.0 ± 18.9 minutes, a 62.3% reduction (P < 0.0001). There was no significant difference in the total operative time (209.5 vs. 200.9 minutes; P = 0.42) or in voice outcome. This sequential anesthetic technique has been easily adopted by multiple anesthesiologists and nurse anesthetists at our institution. TP-AA is effectively performed under sequential GA-SA technique with a significant reduction in the duration of time under sedation. This allows the surgeon to perform the technically more challenging part of the surgery under GA, without having to contend with variability in patient tolerance for laryngeal manipulation under sedation. 3b. Laryngoscope, 127:2813-2817, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

The Sequential Application of Macroalgal Biosorbents for the Bioremediation of a Complex Industrial Effluent

PubMed Central

Kidgell, Joel T.; de Nys, Rocky; Paul, Nicholas A.; Roberts, David A.

2014-01-01

Fe-treated biochar and raw biochar produced from macroalgae are effective biosorbents of metalloids and metals, respectively. However, the treatment of complex effluents that contain both metalloid and metal contaminants presents a challenging scenario. We test a multiple-biosorbent approach to bioremediation using Fe-biochar and biochar to remediate both metalloids and metals from the effluent from a coal-fired power station. First, a model was derived from published data for this effluent to predict the biosorption of 21 elements by Fe-biochar and biochar. The modelled outputs were then used to design biosorption experiments using Fe-biochar and biochar, both simultaneously and in sequence, to treat effluent containing multiple contaminants in excess of water quality criteria. The waste water was produced during ash disposal at an Australian coal-fired power station. The application of Fe-biochar and biochar, either simultaneously or sequentially, resulted in a more comprehensive remediation of metalloids and metals compared to either biosorbent used individually. The most effective treatment was the sequential use of Fe-biochar to remove metalloids from the waste water, followed by biochar to remove metals. Al, Cd, Cr, Cu, Mn, Ni, Pb, Zn were reduced to the lowest concentration following the sequential application of the two biosorbents, and their final concentrations were predicted by the model. Overall, 17 of the 21 elements measured were remediated to, or below, the concentrations that were predicted by the model. Both metalloids and metals can be remediated from complex effluent using biosorbents with different characteristics but derived from a single feedstock. Furthermore, the extent of remediation can be predicted for similar effluents using additive models. PMID:25061756

A multi-stage drop-the-losers design for multi-arm clinical trials.

PubMed

Wason, James; Stallard, Nigel; Bowden, Jack; Jennison, Christopher

2017-02-01

Multi-arm multi-stage trials can improve the efficiency of the drug development process when multiple new treatments are available for testing. A group-sequential approach can be used in order to design multi-arm multi-stage trials, using an extension to Dunnett's multiple-testing procedure. The actual sample size used in such a trial is a random variable that has high variability. This can cause problems when applying for funding as the cost will also be generally highly variable. This motivates a type of design that provides the efficiency advantages of a group-sequential multi-arm multi-stage design, but has a fixed sample size. One such design is the two-stage drop-the-losers design, in which a number of experimental treatments, and a control treatment, are assessed at a prescheduled interim analysis. The best-performing experimental treatment and the control treatment then continue to a second stage. In this paper, we discuss extending this design to have more than two stages, which is shown to considerably reduce the sample size required. We also compare the resulting sample size requirements to the sample size distribution of analogous group-sequential multi-arm multi-stage designs. The sample size required for a multi-stage drop-the-losers design is usually higher than, but close to, the median sample size of a group-sequential multi-arm multi-stage trial. In many practical scenarios, the disadvantage of a slight loss in average efficiency would be overcome by the huge advantage of a fixed sample size. We assess the impact of delay between recruitment and assessment as well as unknown variance on the drop-the-losers designs.

Isolating and Examining Sources of Suppression and Multicollinearity in Multiple Linear Regression

ERIC Educational Resources Information Center

Beckstead, Jason W.

2012-01-01

The presence of suppression (and multicollinearity) in multiple regression analysis complicates interpretation of predictor-criterion relationships. The mathematical conditions that produce suppression in regression analysis have received considerable attention in the methodological literature but until now nothing in the way of an analytic…

General Nature of Multicollinearity in Multiple Regression Analysis.

ERIC Educational Resources Information Center

Liu, Richard

1981-01-01

Discusses multiple regression, a very popular statistical technique in the field of education. One of the basic assumptions in regression analysis requires that independent variables in the equation should not be highly correlated. The problem of multicollinearity and some of the solutions to it are discussed. (Author)

Effectiveness of a myocardial infarction protocol in reducing door-to-ballon time.

PubMed

Correia, Luis Cláudio Lemos; Brito, Mariana; Kalil, Felipe; Sabino, Michael; Garcia, Guilherme; Ferreira, Felipe; Matos, Iracy; Jacobs, Peter; Ronzoni, Liliana; Noya-Rabelo, Márcia

2013-07-01

An adequate door-to-balloon time (<120 minutes) is the necessary condition for the efficacy of primary angioplasty in infarction to translate into effectiveness. To describe the effectiveness of a quality of care protocol in reducing the door-to-balloon time. Between May 2010 and August 2012, all individuals undergoing primary angioplasty in our hospital were analyzed. The door time was electronically recorded at the moment the patient took a number to be evaluated in the emergency room, which occurred prior to filling the check-in forms and to the triage. The balloon time was defined as the beginning of artery opening (introduction of the first device). The first 5 months of monitoring corresponded to the period of pre-implementation of the protocol. The protocol comprised the definition of a flowchart of actions from patient arrival at the hospital, the team's awareness raising in relation to the prioritization of time, and provision of a periodic feedback on the results and possible inadequacies. A total of 50 individuals were assessed. They were divided into five groups of 10 sequential patients (one group pre- and four groups post-protocol). The door-to-balloon time regarding the 10 cases recorded before protocol implementation was 200 ± 77 minutes. After protocol implementation, there was a progressive reduction of the door-to-balloon time to 142±78 minutes in the first 10 patients, then to 150±50 minutes, 131±37 minutes and, finally, 116±29 minutes in the three sequential groups of 10 patients, respectively. Linear regression between sequential patients and the door-to-balloon time (r = - 0.41) showed a regression coefficient of - 1.74 minutes. The protocol implementation proved effective in the reduction of the door-to-balloon time.

ℓ p-Norm Multikernel Learning Approach for Stock Market Price Forecasting

PubMed Central

Shao, Xigao; Wu, Kun; Liao, Bifeng

2012-01-01

Linear multiple kernel learning model has been used for predicting financial time series. However, ℓ 1-norm multiple support vector regression is rarely observed to outperform trivial baselines in practical applications. To allow for robust kernel mixtures that generalize well, we adopt ℓ p-norm multiple kernel support vector regression (1 ≤ p < ∞) as a stock price prediction model. The optimization problem is decomposed into smaller subproblems, and the interleaved optimization strategy is employed to solve the regression model. The model is evaluated on forecasting the daily stock closing prices of Shanghai Stock Index in China. Experimental results show that our proposed model performs better than ℓ 1-norm multiple support vector regression model. PMID:23365561

A Quantile Regression Approach to Understanding the Relations Among Morphological Awareness, Vocabulary, and Reading Comprehension in Adult Basic Education Students.

PubMed

Tighe, Elizabeth L; Schatschneider, Christopher

2016-07-01

The purpose of this study was to investigate the joint and unique contributions of morphological awareness and vocabulary knowledge at five reading comprehension levels in adult basic education (ABE) students. We introduce the statistical technique of multiple quantile regression, which enabled us to assess the predictive utility of morphological awareness and vocabulary knowledge at multiple points (quantiles) along the continuous distribution of reading comprehension. To demonstrate the efficacy of our multiple quantile regression analysis, we compared and contrasted our results with a traditional multiple regression analytic approach. Our results indicated that morphological awareness and vocabulary knowledge accounted for a large portion of the variance (82%-95%) in reading comprehension skills across all quantiles. Morphological awareness exhibited the greatest unique predictive ability at lower levels of reading comprehension whereas vocabulary knowledge exhibited the greatest unique predictive ability at higher levels of reading comprehension. These results indicate the utility of using multiple quantile regression to assess trajectories of component skills across multiple levels of reading comprehension. The implications of our findings for ABE programs are discussed. © Hammill Institute on Disabilities 2014.

Stepwise versus Hierarchical Regression: Pros and Cons

ERIC Educational Resources Information Center

Lewis, Mitzi

2007-01-01

Multiple regression is commonly used in social and behavioral data analysis. In multiple regression contexts, researchers are very often interested in determining the "best" predictors in the analysis. This focus may stem from a need to identify those predictors that are supportive of theory. Alternatively, the researcher may simply be interested…

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

Code of Federal Regulations, 2010 CFR

2010-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

Code of Federal Regulations, 2011 CFR

2011-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM−2.5.

Code of Federal Regulations, 2012 CFR

2012-07-01

... reference method samplers shall be of single-filter design (not multi-filter, sequential sample design... and multiplicative bias (comparative slope and intercept). (1) For each test site, calculate the mean...

A spatial scan statistic for multiple clusters.

PubMed

Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie

2011-10-01

Spatial scan statistics are commonly used for geographical disease surveillance and cluster detection. While there are multiple clusters coexisting in the study area, they become difficult to detect because of clusters' shadowing effect to each other. The recently proposed sequential method showed its better power for detecting the second weaker cluster, but did not improve the ability of detecting the first stronger cluster which is more important than the second one. We propose a new extension of the spatial scan statistic which could be used to detect multiple clusters. Through constructing two or more clusters in the alternative hypothesis, our proposed method accounts for other coexisting clusters in the detecting and evaluating process. The performance of the proposed method is compared to the sequential method through an intensive simulation study, in which our proposed method shows better power in terms of both rejecting the null hypothesis and accurately detecting the coexisting clusters. In the real study of hand-foot-mouth disease data in Pingdu city, a true cluster town is successfully detected by our proposed method, which cannot be evaluated to be statistically significant by the standard method due to another cluster's shadowing effect. Copyright © 2011 Elsevier Inc. All rights reserved.

Personalized long-term prediction of cognitive function: Using sequential assessments to improve model performance.

PubMed

Chi, Chih-Lin; Zeng, Wenjun; Oh, Wonsuk; Borson, Soo; Lenskaia, Tatiana; Shen, Xinpeng; Tonellato, Peter J

2017-12-01

Prediction of onset and progression of cognitive decline and dementia is important both for understanding the underlying disease processes and for planning health care for populations at risk. Predictors identified in research studies are typically accessed at one point in time. In this manuscript, we argue that an accurate model for predicting cognitive status over relatively long periods requires inclusion of time-varying components that are sequentially assessed at multiple time points (e.g., in multiple follow-up visits). We developed a pilot model to test the feasibility of using either estimated or observed risk factors to predict cognitive status. We developed two models, the first using a sequential estimation of risk factors originally obtained from 8 years prior, then improved by optimization. This model can predict how cognition will change over relatively long time periods. The second model uses observed rather than estimated time-varying risk factors and, as expected, results in better prediction. This model can predict when newly observed data are acquired in a follow-up visit. Performances of both models that are evaluated in10-fold cross-validation and various patient subgroups show supporting evidence for these pilot models. Each model consists of multiple base prediction units (BPUs), which were trained using the same set of data. The difference in usage and function between the two models is the source of input data: either estimated or observed data. In the next step of model refinement, we plan to integrate the two types of data together to flexibly predict dementia status and changes over time, when some time-varying predictors are measured only once and others are measured repeatedly. Computationally, both data provide upper and lower bounds for predictive performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Variable criteria sequential stopping rule: Validity and power with repeated measures ANOVA, multiple correlation, MANOVA and relation to Chi-square distribution.

PubMed

Fitts, Douglas A

2017-09-21

The variable criteria sequential stopping rule (vcSSR) is an efficient way to add sample size to planned ANOVA tests while holding the observed rate of Type I errors, α o , constant. The only difference from regular null hypothesis testing is that criteria for stopping the experiment are obtained from a table based on the desired power, rate of Type I errors, and beginning sample size. The vcSSR was developed using between-subjects ANOVAs, but it should work with p values from any type of F test. In the present study, the α o remained constant at the nominal level when using the previously published table of criteria with repeated measures designs with various numbers of treatments per subject, Type I error rates, values of ρ, and four different sample size models. New power curves allow researchers to select the optimal sample size model for a repeated measures experiment. The criteria held α o constant either when used with a multiple correlation that varied the sample size model and the number of predictor variables, or when used with MANOVA with multiple groups and two levels of a within-subject variable at various levels of ρ. Although not recommended for use with χ 2 tests such as the Friedman rank ANOVA test, the vcSSR produces predictable results based on the relation between F and χ 2 . Together, the data confirm the view that the vcSSR can be used to control Type I errors during sequential sampling with any t- or F-statistic rather than being restricted to certain ANOVA designs.

C-terminal amino acid residue loss for deprotonated peptide ions containing glutamic acid, aspartic acid, or serine residues at the C-terminus.

PubMed

Li, Zhong; Yalcin, Talat; Cassady, Carolyn J

2006-07-01

Deprotonated peptides containing C-terminal glutamic acid, aspartic acid, or serine residues were studied by sustained off-resonance irradiation collision-induced dissociation (SORI-CID) in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer with ion production by electrospray ionization (ESI). Additional studies were performed by post source decay (PSD) in a matrix-assisted laser desorption ionization/time-of-flight (MALDI/TOF) mass spectrometer. This work included both model peptides synthesized in our laboratory and bioactive peptides with more complex sequences. During SORI-CID and PSD, [M - H]- and [M - 2H]2- underwent an unusual cleavage corresponding to the elimination of the C-terminal residue. Two mechanisms are proposed to occur. They involve nucleophilic attack on the carbonyl carbon of the adjacent residue by either the carboxylate group of the C-terminus or the side chain carboxylate group of C-terminal glutamic acid and aspartic acid residues. To confirm the proposed mechanisms, AAAAAD was labelled by 18O specifically on the side chain of the aspartic acid residue. For peptides that contain multiple C-terminal glutamic acid residues, each of these residues can be sequentially eliminated from the deprotonated ions; a driving force may be the formation of a very stable pyroglutamatic acid neutral. For peptides with multiple aspartic acid residues at the C-terminus, aspartic acid residue loss is not sequential. For peptides with multiple serine residues at the C-terminus, C-terminal residue loss is sequential; however, abundant loss of other neutral molecules also occurs. In addition, the presence of basic residues (arginine or lysine) in the sequence has no effect on C-terminal residue elimination in the negative ion mode.

Different propagation speeds of recalled sequences in plastic spiking neural networks

NASA Astrophysics Data System (ADS)

Huang, Xuhui; Zheng, Zhigang; Hu, Gang; Wu, Si; Rasch, Malte J.

2015-03-01

Neural networks can generate spatiotemporal patterns of spike activity. Sequential activity learning and retrieval have been observed in many brain areas, and e.g. is crucial for coding of episodic memory in the hippocampus or generating temporal patterns during song production in birds. In a recent study, a sequential activity pattern was directly entrained onto the neural activity of the primary visual cortex (V1) of rats and subsequently successfully recalled by a local and transient trigger. It was observed that the speed of activity propagation in coordinates of the retinotopically organized neural tissue was constant during retrieval regardless how the speed of light stimulation sweeping across the visual field during training was varied. It is well known that spike-timing dependent plasticity (STDP) is a potential mechanism for embedding temporal sequences into neural network activity. How training and retrieval speeds relate to each other and how network and learning parameters influence retrieval speeds, however, is not well described. We here theoretically analyze sequential activity learning and retrieval in a recurrent neural network with realistic synaptic short-term dynamics and STDP. Testing multiple STDP rules, we confirm that sequence learning can be achieved by STDP. However, we found that a multiplicative nearest-neighbor (NN) weight update rule generated weight distributions and recall activities that best matched the experiments in V1. Using network simulations and mean-field analysis, we further investigated the learning mechanisms and the influence of network parameters on recall speeds. Our analysis suggests that a multiplicative STDP rule with dominant NN spike interaction might be implemented in V1 since recall speed was almost constant in an NMDA-dominant regime. Interestingly, in an AMPA-dominant regime, neural circuits might exhibit recall speeds that instead follow the change in stimulus speeds. This prediction could be tested in experiments.

A Method of Calculating Functional Independence Measure at Discharge from Functional Independence Measure Effectiveness Predicted by Multiple Regression Analysis Has a High Degree of Predictive Accuracy.

PubMed

Tokunaga, Makoto; Watanabe, Susumu; Sonoda, Shigeru

2017-09-01

Multiple linear regression analysis is often used to predict the outcome of stroke rehabilitation. However, the predictive accuracy may not be satisfactory. The objective of this study was to elucidate the predictive accuracy of a method of calculating motor Functional Independence Measure (mFIM) at discharge from mFIM effectiveness predicted by multiple regression analysis. The subjects were 505 patients with stroke who were hospitalized in a convalescent rehabilitation hospital. The formula "mFIM at discharge = mFIM effectiveness × (91 points - mFIM at admission) + mFIM at admission" was used. By including the predicted mFIM effectiveness obtained through multiple regression analysis in this formula, we obtained the predicted mFIM at discharge (A). We also used multiple regression analysis to directly predict mFIM at discharge (B). The correlation between the predicted and the measured values of mFIM at discharge was compared between A and B. The correlation coefficients were .916 for A and .878 for B. Calculating mFIM at discharge from mFIM effectiveness predicted by multiple regression analysis had a higher degree of predictive accuracy of mFIM at discharge than that directly predicted. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Students' conceptual performance on synthesis physics problems with varying mathematical complexity

NASA Astrophysics Data System (ADS)

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-06-01

A body of research on physics problem solving has focused on single-concept problems. In this study we use "synthesis problems" that involve multiple concepts typically taught in different chapters. We use two types of synthesis problems, sequential and simultaneous synthesis tasks. Sequential problems require a consecutive application of fundamental principles, and simultaneous problems require a concurrent application of pertinent concepts. We explore students' conceptual performance when they solve quantitative synthesis problems with varying mathematical complexity. Conceptual performance refers to the identification, follow-up, and correct application of the pertinent concepts. Mathematical complexity is determined by the type and the number of equations to be manipulated concurrently due to the number of unknowns in each equation. Data were collected from written tasks and individual interviews administered to physics major students (N =179 ) enrolled in a second year mechanics course. The results indicate that mathematical complexity does not impact students' conceptual performance on the sequential tasks. In contrast, for the simultaneous problems, mathematical complexity negatively influences the students' conceptual performance. This difference may be explained by the students' familiarity with and confidence in particular concepts coupled with cognitive load associated with manipulating complex quantitative equations. Another explanation pertains to the type of synthesis problems, either sequential or simultaneous task. The students split the situation presented in the sequential synthesis tasks into segments but treated the situation in the simultaneous synthesis tasks as a single event.

Sequential delivery of TAT-HSP27 and VEGF using microsphere/hydrogel hybrid systems for therapeutic angiogenesis.

PubMed

Shin, Seung-Hwa; Lee, Jangwook; Lim, Kwang Suk; Rhim, Taiyoun; Lee, Sang Kyung; Kim, Yong-Hee; Lee, Kuen Yong

2013-02-28

Ischemic disease is associated with high mortality and morbidity rates, and therapeutic angiogenesis via systemic or local delivery of protein drugs is one potential approach to treat the disease. In this study, we hypothesized that combined delivery of TAT-HSP27 (HSP27 fused with transcriptional activator) and VEGF could enhance the therapeutic efficacy in an ischemic mouse model, and that sequential release could be critical in therapeutic angiogenesis. Alginate hydrogels containing TAT-HSP27 as an anti-apoptotic agent were prepared, and porous PLGA microspheres loaded with VEGF as an angiogenic agent were incorporated into the hydrogels to prepare microsphere/hydrogel hybrid delivery systems. Sequential in vitro release of TAT-HSP27 and VEGF was achieved by the hybrid systems. TAT-HSP27 was depleted from alginate gels in 7 days, while VEGF was continually released for 28 days. The release rate of VEGF was attenuated by varying the porous structures of PLGA microspheres. Sequential delivery of TAT-HSP27 and VEGF was critical to protect against muscle degeneration and fibrosis, as well as to promote new blood vessel formation in the ischemic site of a mouse model. This approach to controlling the sequential release behaviors of multiple drugs could be useful in the design of novel drug delivery systems for therapeutic angiogenesis. Copyright © 2012 Elsevier B.V. All rights reserved.

Bursts and heavy tails in temporal and sequential dynamics of foraging decisions.

PubMed

Jung, Kanghoon; Jang, Hyeran; Kralik, Jerald D; Jeong, Jaeseung

2014-08-01

A fundamental understanding of behavior requires predicting when and what an individual will choose. However, the actual temporal and sequential dynamics of successive choices made among multiple alternatives remain unclear. In the current study, we tested the hypothesis that there is a general bursting property in both the timing and sequential patterns of foraging decisions. We conducted a foraging experiment in which rats chose among four different foods over a continuous two-week time period. Regarding when choices were made, we found bursts of rapidly occurring actions, separated by time-varying inactive periods, partially based on a circadian rhythm. Regarding what was chosen, we found sequential dynamics in affective choices characterized by two key features: (a) a highly biased choice distribution; and (b) preferential attachment, in which the animals were more likely to choose what they had previously chosen. To capture the temporal dynamics, we propose a dual-state model consisting of active and inactive states. We also introduce a satiation-attainment process for bursty activity, and a non-homogeneous Poisson process for longer inactivity between bursts. For the sequential dynamics, we propose a dual-control model consisting of goal-directed and habit systems, based on outcome valuation and choice history, respectively. This study provides insights into how the bursty nature of behavior emerges from the interaction of different underlying systems, leading to heavy tails in the distribution of behavior over time and choices.

Structural Optimization for Reliability Using Nonlinear Goal Programming

NASA Technical Reports Server (NTRS)

El-Sayed, Mohamed E.

1999-01-01

This report details the development of a reliability based multi-objective design tool for solving structural optimization problems. Based on two different optimization techniques, namely sequential unconstrained minimization and nonlinear goal programming, the developed design method has the capability to take into account the effects of variability on the proposed design through a user specified reliability design criterion. In its sequential unconstrained minimization mode, the developed design tool uses a composite objective function, in conjunction with weight ordered design objectives, in order to take into account conflicting and multiple design criteria. Multiple design criteria of interest including structural weight, load induced stress and deflection, and mechanical reliability. The nonlinear goal programming mode, on the other hand, provides for a design method that eliminates the difficulty of having to define an objective function and constraints, while at the same time has the capability of handling rank ordered design objectives or goals. For simulation purposes the design of a pressure vessel cover plate was undertaken as a test bed for the newly developed design tool. The formulation of this structural optimization problem into sequential unconstrained minimization and goal programming form is presented. The resulting optimization problem was solved using: (i) the linear extended interior penalty function method algorithm; and (ii) Powell's conjugate directions method. Both single and multi-objective numerical test cases are included demonstrating the design tool's capabilities as it applies to this design problem.

Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

PubMed Central

Yu, Pingfeng; Li, Mengyan; Dai, Zhaoyi; Alvarez, Pedro J. J.

2015-01-01

Many studies on phage biology are based on isolation methods that may inadvertently select for narrow-host-range phages. Consequently, broad-host-range phages, whose ecological significance is largely unexplored, are consistently overlooked. To enhance research on such polyvalent phages, we developed two sequential multihost isolation methods and tested both culture-dependent and culture-independent phage libraries for broad infectivity. Lytic phages isolated from activated sludge were capable of interspecies or even interorder infectivity without a significant reduction in the efficiency of plating (0.45 to 1.15). Two polyvalent phages (PX1 of the Podoviridae family and PEf1 of the Siphoviridae family) were characterized in terms of adsorption rate (3.54 × 10−10 to 8.53 × 10−10 ml/min), latent time (40 to 55 min), and burst size (45 to 99 PFU/cell), using different hosts. These phages were enriched with a nonpathogenic host (Pseudomonas putida F1 or Escherichia coli K-12) and subsequently used to infect model problematic bacteria. By using a multiplicity of infection of 10 in bacterial challenge tests, >60% lethality was observed for Pseudomonas aeruginosa relative to uninfected controls. The corresponding lethality for Pseudomonas syringae was ∼50%. Overall, this work suggests that polyvalent phages may be readily isolated from the environment by using different sequential hosts, and this approach should facilitate the study of their ecological significance as well as enable novel applications. PMID:26590277

Use of Empirical Estimates of Shrinkage in Multiple Regression: A Caution.

ERIC Educational Resources Information Center

Kromrey, Jeffrey D.; Hines, Constance V.

1995-01-01

The accuracy of four empirical techniques to estimate shrinkage in multiple regression was studied through Monte Carlo simulation. None of the techniques provided unbiased estimates of the population squared multiple correlation coefficient, but the normalized jackknife and bootstrap techniques demonstrated marginally acceptable performance with…

Enhance-Synergism and Suppression Effects in Multiple Regression

ERIC Educational Resources Information Center

Lipovetsky, Stan; Conklin, W. Michael

2004-01-01

Relations between pairwise correlations and the coefficient of multiple determination in regression analysis are considered. The conditions for the occurrence of enhance-synergism and suppression effects when multiple determination becomes bigger than the total of squared correlations of the dependent variable with the regressors are discussed. It…

Some controversial multiple testing problems in regulatory applications.

PubMed

Hung, H M James; Wang, Sue-Jane

2009-01-01

Multiple testing problems in regulatory applications are often more challenging than the problems of handling a set of mathematical symbols representing multiple null hypotheses under testing. In the union-intersection setting, it is important to define a family of null hypotheses relevant to the clinical questions at issue. The distinction between primary endpoint and secondary endpoint needs to be considered properly in different clinical applications. Without proper consideration, the widely used sequential gate keeping strategies often impose too many logical restrictions to make sense, particularly to deal with the problem of testing multiple doses and multiple endpoints, the problem of testing a composite endpoint and its component endpoints, and the problem of testing superiority and noninferiority in the presence of multiple endpoints. Partitioning the null hypotheses involved in closed testing into clinical relevant orderings or sets can be a viable alternative to resolving the illogical problems requiring more attention from clinical trialists in defining the clinical hypotheses or clinical question(s) at the design stage. In the intersection-union setting there is little room for alleviating the stringency of the requirement that each endpoint must meet the same intended alpha level, unless the parameter space under the null hypothesis can be substantially restricted. Such restriction often requires insurmountable justification and usually cannot be supported by the internal data. Thus, a possible remedial approach to alleviate the possible conservatism as a result of this requirement is a group-sequential design strategy that starts with a conservative sample size planning and then utilizes an alpha spending function to possibly reach the conclusion early.

The architecture of visual narrative comprehension: the interaction of narrative structure and page layout in understanding comics.

PubMed

Cohn, Neil

2014-01-01

How do people make sense of the sequential images in visual narratives like comics? A growing literature of recent research has suggested that this comprehension involves the interaction of multiple systems: The creation of meaning across sequential images relies on a "narrative grammar" that packages conceptual information into categorical roles organized in hierarchic constituents. These images are encapsulated into panels arranged in the layout of a physical page. Finally, how panels frame information can impact both the narrative structure and page layout. Altogether, these systems operate in parallel to construct the Gestalt whole of comprehension of this visual language found in comics.

Sequential Voluntary Cough and Aspiration or Aspiration Risk in Parkinson’s Disease

PubMed Central

Hegland, Karen Wheeler; Okun, Michael S.; Troche, Michelle S.

2015-01-01

Background Disordered swallowing, or dysphagia, is almost always present to some degree in people with Parkinson’s disease (PD), either causing aspiration or greatly increasing the risk for aspiration during swallowing. This likely contributes to aspiration pneumonia, a leading cause of death in this patient population. Effective airway protection is dependent upon multiple behaviors, including cough and swallowing. Single voluntary cough function is disordered in people with PD and dysphagia. However, the appropriate response to aspirate material is more than one cough, or sequential cough. The goal of this study was to examine voluntary sequential coughing in people with PD, with and without dysphagia. Methods Forty adults diagnosed with idiopathic PD produced two trials of sequential voluntary cough. The cough airflows were obtained using pneumotachograph and facemask and subsequently digitized and recorded. All participants received a modified barium swallow study as part of their clinical care, and the worst penetration–aspiration score observed was used to determine whether the patient had dysphagia. Results There were significant differences in the compression phase duration, peak expiratory flow rates, and amount of air expired of the sequential cough produced by participants with and without dysphagia. Conclusions The presence of dysphagia in people with PD is associated with disordered cough function. Sequential cough, which is important in removing aspirate material from large- and smaller-diameter airways, is also impaired in people with PD and dysphagia compared with those without dysphagia. There may be common neuroanatomical substrates for cough and swallowing impairment in PD leading to the co-occurrence of these dysfunctions. PMID:24792231

Sequential dengue virus infections detected in active and passive surveillance programs in Thailand, 1994-2010.

PubMed

Bhoomiboonchoo, Piraya; Nisalak, Ananda; Chansatiporn, Natkamol; Yoon, In-Kyu; Kalayanarooj, Siripen; Thipayamongkolgul, Mathuros; Endy, Timothy; Rothman, Alan L; Green, Sharone; Srikiatkhachorn, Anon; Buddhari, Darunee; Mammen, Mammen P; Gibbons, Robert V

2015-03-14

The effect of prior dengue virus (DENV) exposure on subsequent heterologous infection can be beneficial or detrimental depending on many factors including timing of infection. We sought to evaluate this effect by examining a large database of DENV infections captured by both active and passive surveillance encompassing a wide clinical spectrum of disease. We evaluated datasets from 17 years of hospital-based passive surveillance and nine years of cohort studies, including clinical and subclinical DENV infections, to assess the outcomes of sequential heterologous infections. Chi square or Fisher's exact test was used to compare proportions of infection outcomes such as disease severity; ANOVA was used for continuous variables. Multivariate logistic regression was used to assess risk factors for infection outcomes. Of 38,740 DENV infections, two or more infections were detected in 502 individuals; 14 had three infections. The mean ages at the time of the first and second detected infections were 7.6 ± 3.0 and 11.2 ± 3.0 years. The shortest time between sequential infections was 66 days. A longer time interval between sequential infections was associated with dengue hemorrhagic fever (DHF) in the second detected infection (OR 1.3, 95% CI 1.2-1.4). All possible sequential serotype pairs were observed among 201 subjects with DHF at the second detected infection, except DENV-4 followed by DENV-3. Among DENV infections detected in cohort subjects by active study surveillance and subsequent non-study hospital-based passive surveillance, hospitalization at the first detected infection increased the likelihood of hospitalization at the second detected infection. Increasing time between sequential DENV infections was associated with greater severity of the second detected infection, supporting the role of heterotypic immunity in both protection and enhancement. Hospitalization was positively associated between the first and second detected infections, suggesting a possible predisposition in some individuals to more severe dengue disease.

PC_Eyewitness: evaluating the New Jersey method.

PubMed

MacLin, Otto H; Phelan, Colin M

2007-05-01

One important variable in eyewitness identification research is lineup administration procedure. Lineups administered sequentially (one at a time) have been shown to reduce the number of false identifications in comparison with those administered simultaneously (all at once). As a result, some policymakers have adopted sequential administration. However, they have made slight changes to the method used in psychology laboratories. Eyewitnesses in the field are allowed to take multiple passes through a lineup, whereas participants in the laboratory are allowed only one pass. PC_Eyewitness (PCE) is a computerized system used to construct and administer simultaneous or sequential lineups in both the laboratory and the field. It is currently being used in laboratories investigating eyewitness identification in the United States, Canada, and abroad. A modified version of PCE is also being developed for a local police department. We developed a new module for PCE, the New Jersey module, to examine the effects of a second pass. We found that the sequential advantage was eliminated when the participants were allowed to view the lineup a second time. The New Jersey module, and steps we are taking to improve on the module, are presented here and are being made available to the research and law enforcement communities.

Derivatized versions of ligase enzymes for constructing DNA sequences

DOEpatents

Mariella, Jr., Raymond P.; Christian, Allen T [Tracy, CA; Tucker, James D [Novi, MN; Dzenitis, John M [Livermore, CA; Papavasiliou, Alexandros P [Oakland, CA

2006-08-15

A method of making very long, double-stranded synthetic poly-nucleotides. A multiplicity of short oligonucleotides is provided. The short oligonucleotides are sequentially hybridized to each other. Enzymatic ligation of the oligonucleotides provides a contiguous piece of PCR-ready DNA of predetermined sequence.

Predicting the relatiave vulnerability of near-coastal species to climate change using a rule-based ecoinformatics approach

EPA Science Inventory

Background/Questions/Methods Near-coastal species are threatened by multiple climate change drivers, including temperature increases, ocean acidification, and sea level rise. To identify vulnerable habitats, geographic regions, and species, we developed a sequential, rule-based...

Evaluating Pharmacokinetic and Pharmacodynamic Interactions with Computational Models in Cumulative Risk Assessment

EPA Science Inventory

Simultaneous or sequential exposure to multiple chemicals may cause interactions in the pharmacokinetics (PK) and/or pharmacodynamics (PD) of the individual chemicals. Such interactions can cause modification of the internal or target dose/response of one chemical in the mixture ...

A combined parasitological molecular approach for noninvasive characterization of parasitic nematode communities in wild hosts

USDA-ARS?s Scientific Manuscript database

Most hosts are concurrently or sequentially infected with multiple parasites, thus fully understanding interactions between individual parasite species and their hosts depends on accurate characterization of the parasite community. For parasitic nematodes, non-invasive methods for obtaining quantita...

An Effect Size for Regression Predictors in Meta-Analysis

ERIC Educational Resources Information Center

Aloe, Ariel M.; Becker, Betsy Jane

2012-01-01

A new effect size representing the predictive power of an independent variable from a multiple regression model is presented. The index, denoted as r[subscript sp], is the semipartial correlation of the predictor with the outcome of interest. This effect size can be computed when multiple predictor variables are included in the regression model…

Regression Analysis: Legal Applications in Institutional Research

ERIC Educational Resources Information Center

Frizell, Julie A.; Shippen, Benjamin S., Jr.; Luna, Andrew L.

2008-01-01

This article reviews multiple regression analysis, describes how its results should be interpreted, and instructs institutional researchers on how to conduct such analyses using an example focused on faculty pay equity between men and women. The use of multiple regression analysis will be presented as a method with which to compare salaries of…

RAWS II: A MULTIPLE REGRESSION ANALYSIS PROGRAM,

DTIC Science & Technology

This memorandum gives instructions for the use and operation of a revised version of RAWS, a multiple regression analysis program. The program...of preprocessed data, the directed retention of variable, listing of the matrix of the normal equations and its inverse, and the bypassing of the regression analysis to provide the input variable statistics only. (Author)

Incremental Net Effects in Multiple Regression

ERIC Educational Resources Information Center

Lipovetsky, Stan; Conklin, Michael

2005-01-01

A regular problem in regression analysis is estimating the comparative importance of the predictors in the model. This work considers the 'net effects', or shares of the predictors in the coefficient of the multiple determination, which is a widely used characteristic of the quality of a regression model. Estimation of the net effects can be a…

Floating Data and the Problem with Illustrating Multiple Regression.

ERIC Educational Resources Information Center

Sachau, Daniel A.

2000-01-01

Discusses how to introduce basic concepts of multiple regression by creating a large-scale, three-dimensional regression model using the classroom walls and floor. Addresses teaching points that should be covered and reveals student reaction to the model. Finds that the greatest benefit of the model is the low fear, walk-through, nonmathematical…

Ceruletide intravenous dose-response study by a simplified scintigraphic technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnamurthy, G.T.; Turner, F.E.; Mangham, D.

1985-04-01

The intravenous dose response of a ceruletide diethylamine (ceruletide) was established by a simplified scintigraphic technique where multiple graded doses were given sequentially on a single occasion. The gallbladder volume was presented nongeometrically by /sup 99m/Tc-IDA counts. The mean latent period, ejection period, and ejection rate were similar for all four groups of subjects given 1-20 ng/kg of ceruletide. The ejection fractions were similar to the values when the identical dose of ceruletide was administered sequentially either before or after another dose. A dose of 5 ng/kg produced the most physiologic type of emptying. Intravenous doses of 10 ng/kg andmore » larger caused adverse reactions in 42% of the total doses in the form of abdominal pain, nausea, systolic and diastolic hypotension, or bradycardia. It is concluded that the dose response of a cholecystokininlike agent (ceruletide) can be established reliably by a scintigraphic technique where multiple graded doses are given on a single occasion.« less

Mechanism Design for Task Procurement with Flexible Quality of Service

NASA Astrophysics Data System (ADS)

Gerding, Enrico H.; Larson, Kate; Rogers, Alex; Jennings, Nicholas R.

In this paper, we consider the problem where an agent wishes to complete a single computational task, but lacks the required resources. Instead, it must contract self-interested service providers, who are able to flexibly manipulate the quality of service they deliver, in order to maximise their own utility. We extend an existing model to allow for multiple such service providers to be contracted for the same task, and derive optimal task procurement mechanisms in the setting where the agent has full knowledge of the cost functions of these service providers (considering both simultaneous and sequential procurement). We then extend these results to the incomplete information setting where the agent must elicit cost information from the service providers, and we characterise a family of incentive-compatible and individually-rational mechanisms. We show empirically that sequential procurement always generates greater utility for the agent compared to simultaneous procurement, and that over a range of settings, contracting multiple providers is preferable to contracting just one.

Separation of left and right lungs using 3D information of sequential CT images and a guided dynamic programming algorithm

PubMed Central

Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin

2011-01-01

Objective this article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on CT examinations. Methods we developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. Results the scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing dataset of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. Conclusions The proposed method is able to robustly and accurately disconnect all connections between left and right lungs and the guided dynamic programming algorithm is able to remove redundant processing. PMID:21412104

Randomized Controlled Trial for Behavioral Smoking and Weight Control Treatment: Effect of Concurrent versus Sequential Intervention

PubMed Central

Spring, Bonnie; Doran, Neal; Pagoto, Sherry; Schneider, Kristin; Pingitore, Regina; Hedeker, Don

2014-01-01

Prospects for changing multiple health behaviors conjointly remain controversial. We compared effects on tobacco abstinence and weight gain of adding diet and exercise concurrently or after smoking treatment. Female regular smokers (n=315) randomized to 3 conditions received 16 weeks of behavioral smoking treatment, quit at week 5, and were followed for 9 months after the quit date. Weight management was added to the first 8 weeks for Early Diet (ED), the final 8 weeks for Late Diet (LD), and omitted for Control. Both Diet groups tended to show greater bio-verified abstinence than Control although differences were nonsignificant. Compared to Control, ED initially suppressed weight gain but lost that effect over time, whereas LD initially lacked but gradually acquired a weight suppression effect that stabilized [p = .004]. Behavioral weight control did not undermine smoking cessation and slowed the rate of weight gain when initiated after the smoking quit date, supporting a sequential approach to multiple behavior change. PMID:15482037

Separation of left and right lungs using 3-dimensional information of sequential computed tomography images and a guided dynamic programming algorithm.

PubMed

Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin

2011-01-01

This article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on computed tomography (CT) examinations. We developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. The scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing data set of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. The proposed method is able to robustly and accurately disconnect all connections between left and right lungs, and the guided dynamic programming algorithm is able to remove redundant processing.

Using Multiple and Logistic Regression to Estimate the Median WillCost and Probability of Cost and Schedule Overrun for Program Managers

DTIC Science & Technology

2017-03-23

PUBLIC RELEASE; DISTRIBUTION UNLIMITED Using Multiple and Logistic Regression to Estimate the Median Will- Cost and Probability of Cost and... Cost and Probability of Cost and Schedule Overrun for Program Managers Ryan C. Trudelle Follow this and additional works at: https://scholar.afit.edu...afit.edu. Recommended Citation Trudelle, Ryan C., "Using Multiple and Logistic Regression to Estimate the Median Will- Cost and Probability of Cost and

Impact of sequential proton density fat fraction for quantification of hepatic steatosis in nonalcoholic fatty liver disease.

PubMed

Idilman, Ilkay S; Keskin, Onur; Elhan, Atilla Halil; Idilman, Ramazan; Karcaaltincaba, Musturay

2014-05-01

To determine the utility of sequential MRI-estimated proton density fat fraction (MRI-PDFF) for quantification of the longitudinal changes in liver fat content in individuals with nonalcoholic fatty liver disease (NAFLD). A total of 18 consecutive individuals (M/F: 10/8, mean age: 47.7±9.8 years) diagnosed with NAFLD, who underwent sequential PDFF calculations for the quantification of hepatic steatosis at two different time points, were included in the study. All patients underwent T1-independent volumetric multi-echo gradient-echo imaging with T2* correction and spectral fat modeling. A close correlation for quantification of hepatic steatosis between the initial MRI-PDFF and liver biopsy was observed (rs=0.758, p<0.001). The median interval between two sequential MRI-PDFF measurements was 184 days. From baseline to the end of the follow-up period, serum GGT level and homeostasis model assessment score were significantly improved (p=0.015, p=0.006, respectively), whereas BMI, serum AST, and ALT levels were slightly decreased. MRI-PDFFs were significantly improved (p=0.004). A good correlation between two sequential MRI-PDFF calculations was observed (rs=0.714, p=0.001). With linear regression analyses, only delta serum ALT levels had a significant effect on delta MRI-PDFF calculations (r2=38.6%, p=0.006). At least 5.9% improvement in MRI-PDFF is needed to achieve a normalized abnormal ALT level. The improvement of MRI-PDFF score was associated with the improvement of biochemical parameters in patients who had improvement in delta MRI-PDFF (p<0.05). MRI-PDFF can be used for the quantification of the longitudinal changes of hepatic steatosis. The changes in serum ALT levels significantly reflected changes in MRI-PDFF in patients with NAFLD.

Sequential stages and distribution patterns of aging-related tau astrogliopathy (ARTAG) in the human brain.

PubMed

Kovacs, Gabor G; Xie, Sharon X; Robinson, John L; Lee, Edward B; Smith, Douglas H; Schuck, Theresa; Lee, Virginia M-Y; Trojanowski, John Q

2018-06-11

Aging-related tau astrogliopathy (ARTAG) describes tau pathology in astrocytes in different locations and anatomical regions. In the present study we addressed the question of whether sequential distribution patterns can be recognized for ARTAG or astroglial tau pathologies in both primary FTLD-tauopathies and non-FTLD-tauopathy cases. By evaluating 687 postmortem brains with diverse disorders we identified ARTAG in 455. We evaluated frequencies and hierarchical clustering of anatomical involvement and used conditional probability and logistic regression to model the sequential distribution of ARTAG and astroglial tau pathologies across different brain regions. For subpial and white matter ARTAG we recognize three and two patterns, respectively, each with three stages initiated or ending in the amygdala. Subependymal ARTAG does not show a clear sequential pattern. For grey matter (GM) ARTAG we recognize four stages including a striatal pathway of spreading towards the cortex and/or amygdala, and the brainstem, and an amygdala pathway, which precedes the involvement of the striatum and/or cortex and proceeds towards the brainstem. GM ARTAG and astrocytic plaque pathology in corticobasal degeneration follows a predominantly frontal-parietal cortical to temporal-occipital cortical, to subcortical, to brainstem pathway (four stages). GM ARTAG and tufted astrocyte pathology in progressive supranuclear palsy shows a striatum to frontal-parietal cortical to temporal to occipital, to amygdala, and to brainstem sequence (four stages). In Pick's disease cases with astroglial tau pathology an overlapping pattern with PSP can be appreciated. We conclude that tau-astrogliopathy type-specific sequential patterns cannot be simplified as neuron-based staging systems. The proposed cytopathological and hierarchical stages provide a conceptual approach to identify the initial steps of the pathogenesis of tau pathologies in ARTAG and primary FTLD-tauopathies.

"Mad or bad?": burden on caregivers of patients with personality disorders.

PubMed

Bauer, Rita; Döring, Antje; Schmidt, Tanja; Spießl, Hermann

2012-12-01

The burden on caregivers of patients with personality disorders is often greatly underestimated or completely disregarded. Possibilities for caregiver support have rarely been assessed. Thirty interviews were conducted with caregivers of such patients to assess illness-related burden. Responses were analyzed with a mixed method of qualitative and quantitative analysis in a sequential design. Patient and caregiver data, including sociodemographic and disease-related variables, were evaluated with regression analysis and regression trees. Caregiver statements (n = 404) were summarized into 44 global statements. The most frequent global statements were worries about the burden on other family members (70.0%), poor cooperation with clinical centers and other institutions (60.0%), financial burden (56.7%), worry about the patient's future (53.3%), and dissatisfaction with the patient's treatment and rehabilitation (53.3%). Linear regression and regression tree analysis identified predictors for more burdened caregivers. Caregivers of patients with personality disorders experience a variety of burdens, some disorder specific. Yet these caregivers often receive little attention or support.

Adaptive Online Sequential ELM for Concept Drift Tackling

PubMed Central

Basaruddin, Chan

2016-01-01

A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM) and Constructive Enhancement OS-ELM (CEOS-ELM) by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM). It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER) and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition. PMID:27594879

Controlled pattern imputation for sensitivity analysis of longitudinal binary and ordinal outcomes with nonignorable dropout.

PubMed

Tang, Yongqiang

2018-04-30

The controlled imputation method refers to a class of pattern mixture models that have been commonly used as sensitivity analyses of longitudinal clinical trials with nonignorable dropout in recent years. These pattern mixture models assume that participants in the experimental arm after dropout have similar response profiles to the control participants or have worse outcomes than otherwise similar participants who remain on the experimental treatment. In spite of its popularity, the controlled imputation has not been formally developed for longitudinal binary and ordinal outcomes partially due to the lack of a natural multivariate distribution for such endpoints. In this paper, we propose 2 approaches for implementing the controlled imputation for binary and ordinal data based respectively on the sequential logistic regression and the multivariate probit model. Efficient Markov chain Monte Carlo algorithms are developed for missing data imputation by using the monotone data augmentation technique for the sequential logistic regression and a parameter-expanded monotone data augmentation scheme for the multivariate probit model. We assess the performance of the proposed procedures by simulation and the analysis of a schizophrenia clinical trial and compare them with the fully conditional specification, last observation carried forward, and baseline observation carried forward imputation methods. Copyright © 2018 John Wiley & Sons, Ltd.

Randomness in the network inhibits cooperation based on the bounded rational collective altruistic decision

NASA Astrophysics Data System (ADS)

Ohdaira, Tetsushi

2014-07-01

Previous studies discussing cooperation employ the best decision that every player knows all information regarding the payoff matrix and selects the strategy of the highest payoff. Therefore, they do not discuss cooperation based on the altruistic decision with limited information (bounded rational altruistic decision). In addition, they do not cover the case where every player can submit his/her strategy several times in a match of the game. This paper is based on Ohdaira's reconsideration of the bounded rational altruistic decision, and also employs the framework of the prisoner's dilemma game (PDG) with sequential strategy. The distinction between this study and the Ohdaira's reconsideration is that the former covers the model of multiple groups, but the latter deals with the model of only two groups. Ohdaira's reconsideration shows that the bounded rational altruistic decision facilitates much more cooperation in the PDG with sequential strategy than Ohdaira and Terano's bounded rational second-best decision does. However, the detail of cooperation of multiple groups based on the bounded rational altruistic decision has not been resolved yet. This study, therefore, shows how randomness in the network composed of multiple groups affects the increase of the average frequency of mutual cooperation (cooperation between groups) based on the bounded rational altruistic decision of multiple groups. We also discuss the results of the model in comparison with related studies which employ the best decision.

Eating the elephant whole or in slices: views of participants in a smoking cessation intervention trial on multiple behaviour changes as sequential or concurrent tasks

PubMed Central

2012-01-01

Background This paper explores smoking cessation participants’ perceptions of attempting weight management alongside smoking cessation within the context of a health improvement intervention implemented in Glasgow, Scotland. Methods One hundred and thirty-eight participants were recruited from smoking cessation classes in areas of multiple deprivation in Glasgow and randomised to intervention, receiving dietary advice, or to control groups. The primary outcome of the study was to determine the % change in body weight. Semi-structured interviews were conducted with a purposive sample of 15 intervention and 15 control participants at weeks 6 (during the intervention) and 24 (at the end of the intervention). The current paper, though predominantly qualitative, links perceptions of behaviour modification to % weight change and cessation rates at week 24 thereby enabling a better understanding of the mediators influencing multiple behaviour change. Results Our findings suggest that participants who perceive separate behaviour changes as part of a broader approach to a healthier lifestyle, and hence attempt behaviour changes concurrently, may be at comparative advantage in positively achieving dual outcomes. Conclusions These findings highlight the need to assess participants’ preference for attempting multiple behaviour changes sequentially or simultaneously in addition to assessing their readiness to change. Further testing of this hypothesis is warranted. Trial Registration ISRCTN94961361 PMID:22759785

Tools to Support Interpreting Multiple Regression in the Face of Multicollinearity

PubMed Central

Kraha, Amanda; Turner, Heather; Nimon, Kim; Zientek, Linda Reichwein; Henson, Robin K.

2012-01-01

While multicollinearity may increase the difficulty of interpreting multiple regression (MR) results, it should not cause undue problems for the knowledgeable researcher. In the current paper, we argue that rather than using one technique to investigate regression results, researchers should consider multiple indices to understand the contributions that predictors make not only to a regression model, but to each other as well. Some of the techniques to interpret MR effects include, but are not limited to, correlation coefficients, beta weights, structure coefficients, all possible subsets regression, commonality coefficients, dominance weights, and relative importance weights. This article will review a set of techniques to interpret MR effects, identify the elements of the data on which the methods focus, and identify statistical software to support such analyses. PMID:22457655

Tools to support interpreting multiple regression in the face of multicollinearity.

PubMed

Kraha, Amanda; Turner, Heather; Nimon, Kim; Zientek, Linda Reichwein; Henson, Robin K

2012-01-01

While multicollinearity may increase the difficulty of interpreting multiple regression (MR) results, it should not cause undue problems for the knowledgeable researcher. In the current paper, we argue that rather than using one technique to investigate regression results, researchers should consider multiple indices to understand the contributions that predictors make not only to a regression model, but to each other as well. Some of the techniques to interpret MR effects include, but are not limited to, correlation coefficients, beta weights, structure coefficients, all possible subsets regression, commonality coefficients, dominance weights, and relative importance weights. This article will review a set of techniques to interpret MR effects, identify the elements of the data on which the methods focus, and identify statistical software to support such analyses.

The comparison between several robust ridge regression estimators in the presence of multicollinearity and multiple outliers

NASA Astrophysics Data System (ADS)

Zahari, Siti Meriam; Ramli, Norazan Mohamed; Moktar, Balkiah; Zainol, Mohammad Said

2014-09-01

In the presence of multicollinearity and multiple outliers, statistical inference of linear regression model using ordinary least squares (OLS) estimators would be severely affected and produces misleading results. To overcome this, many approaches have been investigated. These include robust methods which were reported to be less sensitive to the presence of outliers. In addition, ridge regression technique was employed to tackle multicollinearity problem. In order to mitigate both problems, a combination of ridge regression and robust methods was discussed in this study. The superiority of this approach was examined when simultaneous presence of multicollinearity and multiple outliers occurred in multiple linear regression. This study aimed to look at the performance of several well-known robust estimators; M, MM, RIDGE and robust ridge regression estimators, namely Weighted Ridge M-estimator (WRM), Weighted Ridge MM (WRMM), Ridge MM (RMM), in such a situation. Results of the study showed that in the presence of simultaneous multicollinearity and multiple outliers (in both x and y-direction), the RMM and RIDGE are more or less similar in terms of superiority over the other estimators, regardless of the number of observation, level of collinearity and percentage of outliers used. However, when outliers occurred in only single direction (y-direction), the WRMM estimator is the most superior among the robust ridge regression estimators, by producing the least variance. In conclusion, the robust ridge regression is the best alternative as compared to robust and conventional least squares estimators when dealing with simultaneous presence of multicollinearity and outliers.

An improved multiple linear regression and data analysis computer program package

NASA Technical Reports Server (NTRS)

Sidik, S. M.

1972-01-01

NEWRAP, an improved version of a previous multiple linear regression program called RAPIER, CREDUC, and CRSPLT, allows for a complete regression analysis including cross plots of the independent and dependent variables, correlation coefficients, regression coefficients, analysis of variance tables, t-statistics and their probability levels, rejection of independent variables, plots of residuals against the independent and dependent variables, and a canonical reduction of quadratic response functions useful in optimum seeking experimentation. A major improvement over RAPIER is that all regression calculations are done in double precision arithmetic.

Block coordination copolymers

DOEpatents

Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

2014-11-11

The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

Block coordination copolymers

DOEpatents

Koh, Kyoung Moo; Wong-Foy, Antek G.; Matzger, Adam J.; Benin, Annabelle I.; Willis, Richard R.

2012-12-04

The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

Block coordination copolymers

DOEpatents

Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

2012-11-13

The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

Multiple cranial neuropathy: a common diagnostic problem.

PubMed

Garg, R K; Karak, B

1999-10-01

Syndrome of multiple cranial palsies is a common clinical problem routinely encountered in neurological practice. Anatomical patterns of cranial nerves involvement help in localizing the lesion. Various infections, malignant neoplasms and autoimmune vasculitis are common disorders leading to various syndromes of multiple cranial nerve palsies. A large number of diffuse neurological disorders (e.g. Gullian-Barre syndrome, myopathies) may also present with syndrome of multiple cranial nerve palsies. Despite extensive biochemical and radiological work-up the accurate diagnosis may not be established. Few such patients represent "idiopathic" variety of multiple cranial nerve involvement and show good response to corticosteroids. Widespread and sequential involvements of cranial nerves frequently suggest possibility of malignant infiltration of meninges, however, confirmation of diagnosis may not be possible before autopsy.

Variables Associated with Communicative Participation in People with Multiple Sclerosis: A Regression Analysis

ERIC Educational Resources Information Center

Baylor, Carolyn; Yorkston, Kathryn; Bamer, Alyssa; Britton, Deanna; Amtmann, Dagmar

2010-01-01

Purpose: To explore variables associated with self-reported communicative participation in a sample (n = 498) of community-dwelling adults with multiple sclerosis (MS). Method: A battery of questionnaires was administered online or on paper per participant preference. Data were analyzed using multiple linear backward stepwise regression. The…

Predictors of postoperative outcomes of cubital tunnel syndrome treatments using multiple logistic regression analysis.

PubMed

Suzuki, Taku; Iwamoto, Takuji; Shizu, Kanae; Suzuki, Katsuji; Yamada, Harumoto; Sato, Kazuki

2017-05-01

This retrospective study was designed to investigate prognostic factors for postoperative outcomes for cubital tunnel syndrome (CubTS) using multiple logistic regression analysis with a large number of patients. Eighty-three patients with CubTS who underwent surgeries were enrolled. The following potential prognostic factors for disease severity were selected according to previous reports: sex, age, type of surgery, disease duration, body mass index, cervical lesion, presence of diabetes mellitus, Workers' Compensation status, preoperative severity, and preoperative electrodiagnostic testing. Postoperative severity of disease was assessed 2 years after surgery by Messina's criteria which is an outcome measure specifically for CubTS. Bivariate analysis was performed to select candidate prognostic factors for multiple linear regression analyses. Multiple logistic regression analysis was conducted to identify the association between postoperative severity and selected prognostic factors. Both bivariate and multiple linear regression analysis revealed only preoperative severity as an independent risk factor for poor prognosis, while other factors did not show any significant association. Although conflicting results exist regarding prognosis of CubTS, this study supports evidence from previous studies and concludes early surgical intervention portends the most favorable prognosis. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

The effect of social support on quality of life for tinnitus sufferers.

PubMed

Murphy, Colleen Eliza

2012-01-01

To examine the relationship between tinnitus severity, social support and three quality of life measures. Research into other conditions shows that social support helps achieve positive outcomes and improved quality of life. For tinnitus, research suggests social support does not impact on quality of life outcomes. However, research has been limited and the measures used have mixed tinnitus severity, tinnitus handicap and social support into one measure. The aim of this research was to examine the relationship using separate measures. One hundred fifty-four tinnitus sufferers (63.7% males, 36.3% females, Age M = 46.4, SD = 14.97) completed the assessment battery. Three sequential multiple regression analyses were conducted to test the hypothesis that social support moderates the effects of tinnitus severity on each of the dependent variables: tinnitus handicap, depression and general well-being. The severity of one's tinnitus significantly predicted tinnitus handicap, depression and general well-being, but social support did not moderate the relationship. Social support did have a direct relationship on level of depression and general well-being. Tinnitus handicaps appear to be unique but tinnitus sufferers do gain significant benefits from social support.

Meeting students halfway: Increasing self-efficacy and promoting knowledge change in astronomy

NASA Astrophysics Data System (ADS)

Bailey, Janelle M.; Lombardi, Doug; Cordova, Jacqueline R.; Sinatra, Gale M.

2017-12-01

Two motivational factors—self-efficacy and interest—may be especially relevant to deepening students' understanding of astronomy. We examined the relationship between students' self-efficacy for, interest in learning about, and changes in their knowledge of stars, as measured by the Star Properties Concept Inventory (SPCI). Approximately 700 undergraduate students taking introductory astronomy responded to surveys at the start and end of their semester-long course. A sequential multiple regression analysis showed that self-efficacy post explains an appreciable percentage of variance in SPCI posttest scores, more than twice the percentage explained by all the pretest variables (SPCI, self-efficacy, and interest) combined. Knowledge and self-efficacy improved significantly over instruction; interest did not. Follow-up analyses revealed that instructors whose classes increased in self-efficacy also had the greatest increases in knowledge scores. Interviews with these instructors suggest they provide their students with more opportunities for mastery experiences with elaborated, performance-related feedback, as well as strong positive verbal persuasion and vicarious experiences through peer instruction. Through increased understanding of the relationship between motivational constructs (e.g., self-efficacy, interest) and knowledge, we can both improve our models and better inform instruction.

The moderating role of rational beliefs in the relationship between irrational beliefs and posttraumatic stress symptomology.

PubMed

Hyland, Philip; Shevlin, Mark; Adamson, Gary; Boduszek, Daniel

2014-05-01

Rational Emotive Behaviour Therapy (REBT) assumes that rational beliefs act as cognitive protective factors against the development of psychopathology; however little empirical evidence exists regarding the nature of the possible protective effects that they offer. The current study investigates whether rational beliefs moderate the impact of irrational beliefs on posttraumatic stress symptomology (PTS). Three hundred and thirteen active law enforcement, military, and related emergency service personnel took part in the current study. Sequential moderated multiple regression analysis was employed to investigate: (i) the direct impact of irrational beliefs on PTS; (ii) the direct impact of rational beliefs on PTS; (iii) the moderating effects of rational beliefs in the relationship between irrational beliefs and PTS. The irrational beliefs predicted by REBT theory emerged as critical predictors of PTS symptomology, in particular Depreciation beliefs. Rational beliefs (Preferences, and Acceptance beliefs) had a direct, negative impact on levels of PTS, and Acceptance beliefs moderated the impact of Catastrophizing beliefs on PTS. Irrational beliefs are important cognitive vulnerability factors in symptoms of PTS, while rational beliefs (Acceptance) appear to have a protective role in the emergence of PTS symptoms, both directly and by moderating the impact of Catastrophizing beliefs.

The role of body image psychological flexibility on the treatment of eating disorders in a residential facility.

PubMed

Bluett, E J; Lee, E B; Simone, M; Lockhart, G; Twohig, M P; Lensegrav-Benson, Tera; Quakenbush-Roberts, Benita

2016-12-01

The purpose of this study was to test whether pre-treatment levels of psychological flexibility would longitudinally predict quality of life and eating disorder risk in patients at a residential treatment facility for eating disorders. Data on body image psychological flexibility, quality of life, and eating disorder risk were collected from 63 adolescent and 50 adult, female, residential patients (N=113) diagnosed with an eating disorder. These same measures were again collected at post-treatment. Sequential multiple regression analyses were performed to test whether pre-treatment levels of psychological flexibility longitudinally predicted quality of life and eating disorder risk after controlling for age and baseline effects. Pre-treatment psychological flexibility significantly predicted post-treatment quality of life with approximately 19% of the variation being attributable to age and pre-treatment psychological flexibility. Pre-treatment psychological flexibility also significantly predicted post-treatment eating disorder risk with nearly 30% of the variation attributed to age and pre-treatment psychological flexibility. This study suggests that levels of psychological flexibility upon entering treatment for an eating disorder longitudinally predict eating disorder outcome and quality of life. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cleanliness Policy Implementation: Evaluating Retribution Model to Rise Public Satisfaction

NASA Astrophysics Data System (ADS)

Dailiati, Surya; Hernimawati; Prihati; Chintia Utami, Bunga

2018-05-01

This research is based on the principal issues concerning the evaluation of cleanliness retribution policy which has not been optimally be able to improve the Local Revenue of Pekanbaru City and has not improved the cleanliness of Pekanbaru City. It was estimated to be caused by the performance of Garden and Sanitation Department are not in accordance with the requirement of society of Pekanbaru City. The research method used in this study is a mixed method with sequential exploratory strategy. The data collection used are observation, interview and documentation for qualitative research as well as questionnaires for quantitative research. The collected data were analyzed with interactive model of Miles and Huberman for qualitative research and multiple regression analysis for quantitative research. The research result indicated that the model of cleanliness policy implementation that can increase of PAD Pekanbaru City and be able to improve people’s satisfaction divided into two (2) which are the evaluation model and the society satisfaction model. The evaluation model influence by criteria/variable of effectiveness, efficiency, adequacy, equity, responsiveness, and appropriateness, while the society satisfaction model influence by variables of society satisfaction, intentions, goals, plans, programs, and appropriateness of cleanliness retribution collection policy.

The Contribution of Missed Clinic Visits to Disparities in HIV Viral Load Outcomes

PubMed Central

Westfall, Andrew O.; Gardner, Lytt I.; Giordano, Thomas P.; Wilson, Tracey E.; Drainoni, Mari-Lynn; Keruly, Jeanne C.; Rodriguez, Allan E.; Malitz, Faye; Batey, D. Scott; Mugavero, Michael J.

2015-01-01

Objectives. We explored the contribution of missed primary HIV care visits (“no-show”) to observed disparities in virological failure (VF) among Black persons and persons with injection drug use (IDU) history. Methods. We used patient-level data from 6 academic clinics, before the Centers for Disease Control and Prevention and Health Resources and Services Administration Retention in Care intervention. We employed staged multivariable logistic regression and multivariable models stratified by no-show visit frequency to evaluate the association of sociodemographic factors with VF. We used multiple imputations to assign missing viral load values. Results. Among 10 053 patients (mean age = 46 years; 35% female; 64% Black; 15% with IDU history), 31% experienced VF. Although Black patients and patients with IDU history were significantly more likely to experience VF in initial analyses, race and IDU parameter estimates were attenuated after sequential addition of no-show frequency. In stratified models, race and IDU were not statistically significantly associated with VF at any no-show level. Conclusions. Because missed clinic visits contributed to observed differences in viral load outcomes among Black and IDU patients, achieving an improved understanding of differential visit attendance is imperative to reducing disparities in HIV. PMID:26270301

How Internal Political Efficacy Translates Political Knowledge Into Political Participation

PubMed Central

Reichert, Frank

2016-01-01

This study presents evidence for the mediation effect of political knowledge through political self-efficacy (i.e. internal political efficacy) in the prediction of political participation. It employs an action theoretic approach—by and large grounded on the Theory of Planned Behaviour—and uses data from the German Longitudinal Election Study to examine whether political knowledge has distinct direct effects on voting, conventional, and/or unconventional political participation. It argues that political knowledge raises internal political efficacy and thereby indirectly increases the chance that a citizen will participate in politics. The results of mediated multiple regression analyses yield evidence that political knowledge indeed translates into internal political efficacy, thus it affects political participation of various kinds indirectly. However, internal political efficacy and intentions to participate politically yield simultaneous direct effects only on conventional political participation. Sequentially mediated effects appear for voting and conventional political participation, with political knowledge being mediated by internal political efficacy and subsequently also by behavioural intentions. The mediation patterns for unconventional political participation are less clear though. The discussion accounts for restrictions of this study and points to questions for answer by future research. PMID:27298633

Understanding and simulating the material behavior during multi-particle irradiations

PubMed Central

Mir, Anamul H.; Toulemonde, M.; Jegou, C.; Miro, S.; Serruys, Y.; Bouffard, S.; Peuget, S.

2016-01-01

A number of studies have suggested that the irradiation behavior and damage processes occurring during sequential and simultaneous particle irradiations can significantly differ. Currently, there is no definite answer as to why and when such differences are seen. Additionally, the conventional multi-particle irradiation facilities cannot correctly reproduce the complex irradiation scenarios experienced in a number of environments like space and nuclear reactors. Therefore, a better understanding of multi-particle irradiation problems and possible alternatives are needed. This study shows ionization induced thermal spike and defect recovery during sequential and simultaneous ion irradiation of amorphous silica. The simultaneous irradiation scenario is shown to be equivalent to multiple small sequential irradiation scenarios containing latent damage formation and recovery mechanisms. The results highlight the absence of any new damage mechanism and time-space correlation between various damage events during simultaneous irradiation of amorphous silica. This offers a new and convenient way to simulate and understand complex multi-particle irradiation problems. PMID:27466040

Sequential optimization of a terrestrial biosphere model constrained by multiple satellite based products

NASA Astrophysics Data System (ADS)

Ichii, K.; Kondo, M.; Wang, W.; Hashimoto, H.; Nemani, R. R.

2012-12-01

Various satellite-based spatial products such as evapotranspiration (ET) and gross primary productivity (GPP) are now produced by integration of ground and satellite observations. Effective use of these multiple satellite-based products in terrestrial biosphere models is an important step toward better understanding of terrestrial carbon and water cycles. However, due to the complexity of terrestrial biosphere models with large number of model parameters, the application of these spatial data sets in terrestrial biosphere models is difficult. In this study, we established an effective but simple framework to refine a terrestrial biosphere model, Biome-BGC, using multiple satellite-based products as constraints. We tested the framework in the monsoon Asia region covered by AsiaFlux observations. The framework is based on the hierarchical analysis (Wang et al. 2009) with model parameter optimization constrained by satellite-based spatial data. The Biome-BGC model is separated into several tiers to minimize the freedom of model parameter selections and maximize the independency from the whole model. For example, the snow sub-model is first optimized using MODIS snow cover product, followed by soil water sub-model optimized by satellite-based ET (estimated by an empirical upscaling method; Support Vector Regression (SVR) method; Yang et al. 2007), photosynthesis model optimized by satellite-based GPP (based on SVR method), and respiration and residual carbon cycle models optimized by biomass data. As a result of initial assessment, we found that most of default sub-models (e.g. snow, water cycle and carbon cycle) showed large deviations from remote sensing observations. However, these biases were removed by applying the proposed framework. For example, gross primary productivities were initially underestimated in boreal and temperate forest and overestimated in tropical forests. However, the parameter optimization scheme successfully reduced these biases. Our analysis shows that terrestrial carbon and water cycle simulations in monsoon Asia were greatly improved, and the use of multiple satellite observations with this framework is an effective way for improving terrestrial biosphere models.

Mutual Information Item Selection in Adaptive Classification Testing

ERIC Educational Resources Information Center

Weissman, Alexander

2007-01-01

A general approach for item selection in adaptive multiple-category classification tests is provided. The approach uses mutual information (MI), a special case of the Kullback-Leibler distance, or relative entropy. MI works efficiently with the sequential probability ratio test and alleviates the difficulties encountered with using other local-…

Scaffolding the Communication of People with Congenital Deafblindness: An Analysis of Sequential Interaction Patterns

ERIC Educational Resources Information Center

Damen, Saskia; Janssen, Marleen J.; Ruijssenaars, Wied A. J. J. M.; Schuengel, Carlo

2017-01-01

The High Quality Communication intervention aims to stimulate interpersonal communication between individuals with congenital deaf-blindness (CDB) and their social partners. Found effective in multiple-case experiments, the intervention is based on Trevarthen's theory of intersubjective development (Bråten & Trevarthen, 2007), which describes…

Analytical solution for multi-species contaminant transport in finite media with time-varying boundary conditions

USDA-ARS?s Scientific Manuscript database

Most analytical solutions available for the equations governing the advective-dispersive transport of multiple solutes undergoing sequential first-order decay reactions have been developed for infinite or semi-infinite spatial domains and steady-state boundary conditions. In this work we present an ...

Testing for Factorial Invariance in the Context of Construct Validation

ERIC Educational Resources Information Center

Dimitrov, Dimiter M.

2010-01-01

This article describes the logic and procedures behind testing for factorial invariance across groups in the context of construct validation. The procedures include testing for configural, measurement, and structural invariance in the framework of multiple-group confirmatory factor analysis (CFA). The "forward" (sequential constraint imposition)…

The Geometry of Enhancement in Multiple Regression

ERIC Educational Resources Information Center

Waller, Niels G.

2011-01-01

In linear multiple regression, "enhancement" is said to occur when R[superscript 2] = b[prime]r greater than r[prime]r, where b is a p x 1 vector of standardized regression coefficients and r is a p x 1 vector of correlations between a criterion y and a set of standardized regressors, x. When p = 1 then b [is congruent to] r and…

Quantifying and Reducing Uncertainty in Correlated Multi-Area Short-Term Load Forecasting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yannan; Hou, Zhangshuan; Meng, Da

2016-07-17

In this study, we represent and reduce the uncertainties in short-term electric load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the inter-dependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses.

An evaluation of asthma interventions for preteen students.

PubMed

Clark, Noreen M; Shah, Smita; Dodge, Julia A; Thomas, Lara J; Andridge, Rebecca R; Little, Roderick J A

2010-02-01

Asthma is a serious problem for low-income preteens living in disadvantaged communities. Among the chronic diseases of childhood and adolescence, asthma has the highest prevalence and related health care use. School-based asthma interventions have proven successful for older and younger students, but results have not been demonstrated for those in middle school. This randomized controlled study screened students 10-13 years of age in 19 middle schools in low-income communities in Detroit, Michigan. Of the 6,872 students who were screened, 1,292 students were identified with asthma. Schools were matched and randomly assigned to Program 1 or 2 or control. Baseline, 12, and 24 months data were collected by telephone (parents), at school (students) and from school system records. Measures were the students' asthma symptoms, quality of life, academic performance, self-regulation, and asthma management practices. Data were analyzed using multiple imputation with sequential regression analysis. Mixed models and Poisson regressions were used to develop final models. Neither program produced significant change in asthma symptoms or quality of life. One produced improved school grades (p = .02). The other enhanced self-regulation (p = .01) at 24 months. Both slowed the decline in self-regulation in undiagnosed preteens at 12 months and increased self-regulation at 24 months (p = .04; p = .003). Programs had effects on academic performance and self-regulation capacities of students. More developmentally focused interventions may be needed for students at this transitional stage. Disruptive factors in the schools may have reduced both program impact and the potential for outcome assessment.

An Evaluation of Asthma Interventions for Preteen Students

PubMed Central

Clark, Noreen M.; Shah, Smita; Dodge, Julia A.; Thomas, Lara J.; Andridge, Rebecca R.; Little, Roderick J.A.

2013-01-01

Background Asthma is a serious problem for low income, pre teens living in disadvantaged communities. Asthma prevalence and health care use are the highest of the chronic diseases of childhood and adolescence. School based asthma interventions have proven successful for older and younger students but results have not been demonstrated for those in middle school. Methods This randomized controlled study involved 6872 students 10–13 years of age and assessed two programs, 1) self-management and 2) self-management plus peer involvement, provided in 19 middle schools in low income, communities. 1292 students were identified with asthma. Schools were matched and randomly assigned to program one or two or control. Baseline, 12, and 24 months data were collected by telephone (parents), at school (students) and from school system records. Measures were the students’ asthma symptoms, quality of life, academic performance, self-regulation and asthma management practices. Data were analyzed using multiple imputation with sequential regression analysis. Mixed models and Poisson regressions were used to develop final models. Results Neither program produced change in asthma symptoms or quality of life. One produced improved school grades (p=0.02). The other enhanced self-regulation (p=0.01) at 24 months. Both slowed the decline in self-regulation in undiagnosed preteens at 12 months and increased self regulation at 24 months (p=0.04; p=0.003). Conclusion Programs had effects on academic performance and self-regulation capacities of students. More developmentally focused interventions may be needed for students at this transitional stage. Disruptive factors in the schools may have reduced both program impact and the potential for outcome assessment. PMID:20236406

Importance of the structure and nanoporosity of organic matter on the desorption kinetics of benzo[a]pyrene in sediments.

PubMed

Huang, Youda; Zhang, Dainan; Duan, Dandan; Yang, Yu; Xiong, Yongqiang; Ran, Yong

2017-06-01

The desorption kinetics and mechanism were investigated using a Tenax extraction technique on different sediments spiked with radiocarbon-labeled benzo[a]pyrene (BaP). Five sedimentary fractions were sequentially fractionated, and the only nonhydrolyzable organic carbon fractions (NHC) were characterized using advanced solid-state 13 C nuclear magnetic resonance spectroscopy (NMR), improved six end-member model, and a CO 2 gas adsorption technique. The sediments contained high percentages of algaenan and/or sporopollenin but low percentages of black carbon and lignin. A first-order, two-compartment kinetics model described the desorption process very well (R 2  > 0.990). Although some of the organic carbon fractions were significantly related to the desorption kinetics parameters, the NHC fractions showed the highly significant correlation. Moreover, the nanoporosity or specific surface area (SSA) of the NHC fractions was highly related to their OC contents and aliphatic C (R 2  = 0.960, p < 0.01). The multiple regression equations among the desorption kinetics parameters, structural parameters, and nanoporosity were well established (R 2 =>0.999). Nanoporosity and aromatic C were the dominant contributors. Furthermore, the enhanced percentages of desorbed BaP at elevated temperatures significantly showed a linear regression with the structure and nanoporosity. To our knowledge, the above evidence demonstrates for the first time that the transfer (or diffusion) of BaP in the nanopores of condensed aromatic components is the dominant mechanism of the desorption kinetics of BaP at organic matter particle scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

The architecture of visual narrative comprehension: the interaction of narrative structure and page layout in understanding comics

PubMed Central

Cohn, Neil

2014-01-01

How do people make sense of the sequential images in visual narratives like comics? A growing literature of recent research has suggested that this comprehension involves the interaction of multiple systems: The creation of meaning across sequential images relies on a “narrative grammar” that packages conceptual information into categorical roles organized in hierarchic constituents. These images are encapsulated into panels arranged in the layout of a physical page. Finally, how panels frame information can impact both the narrative structure and page layout. Altogether, these systems operate in parallel to construct the Gestalt whole of comprehension of this visual language found in comics. PMID:25071651

Trauma exposure and cigarette smoking: the impact of negative affect and affect-regulatory smoking motives.

PubMed

Farris, Samantha G; Zvolensky, Michael J; Beckham, Jean C; Vujanovic, Anka A; Schmidt, Norman B

2014-01-01

Cognitive-affective mechanisms related to the maintenance of smoking among trauma-exposed individuals are largely unknown. Cross-sectional data from trauma-exposed treatment-seeking smokers (n = 283) were utilized to test a series of multiple mediator models of trauma exposure and smoking, as mediated by the sequential effects of negative affect and affect-modulation smoking motives. The sequential effects of both mediators indirectly predicted the effect of greater trauma exposure types on nicotine dependence, a biochemical index of smoking, perceived barriers to smoking cessation, and greater withdrawal-related problems during past quit attempts. Negative affect and affect-modulation motives for smoking may contribute to the trauma-smoking association.

Trauma Exposure and Cigarette Smoking: The Impact of Negative Affect and Affect-Regulatory Smoking Motives

PubMed Central

Farris, Samantha G.; Zvolensky, Michael J.; Beckham, Jean C.; Vujanovic, Anka A.; Schmidt, Norman B.

2014-01-01

Cognitive-affective mechanisms related to the maintenance of smoking among trauma-exposed individuals are largely unknown. Cross-sectional data from trauma-exposed treatment-seeking smokers (n = 283) were utilized to test a series of multiple mediator models of trauma exposure and smoking, as mediated by the sequential effects of negative affect and affect-modulation smoking motives. The sequential effects of both mediators indirectly predicted the effect of greater trauma exposure types on nicotine dependence, a biochemical index of smoking, perceived barriers to smoking cessation, and greater withdrawal-related problems during past quit attempts. Negative affect and affect-modulation motives for smoking may contribute to the trauma-smoking association. PMID:25299617

Work–Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress

PubMed Central

Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

2018-01-01

After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work–family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work–family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work–family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women’s perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work–family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work–family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress. PMID:29719522

Efficient sequential and parallel algorithms for record linkage.

PubMed

Mamun, Abdullah-Al; Mi, Tian; Aseltine, Robert; Rajasekaran, Sanguthevar

2014-01-01

Integrating data from multiple sources is a crucial and challenging problem. Even though there exist numerous algorithms for record linkage or deduplication, they suffer from either large time needs or restrictions on the number of datasets that they can integrate. In this paper we report efficient sequential and parallel algorithms for record linkage which handle any number of datasets and outperform previous algorithms. Our algorithms employ hierarchical clustering algorithms as the basis. A key idea that we use is radix sorting on certain attributes to eliminate identical records before any further processing. Another novel idea is to form a graph that links similar records and find the connected components. Our sequential and parallel algorithms have been tested on a real dataset of 1,083,878 records and synthetic datasets ranging in size from 50,000 to 9,000,000 records. Our sequential algorithm runs at least two times faster, for any dataset, than the previous best-known algorithm, the two-phase algorithm using faster computation of the edit distance (TPA (FCED)). The speedups obtained by our parallel algorithm are almost linear. For example, we get a speedup of 7.5 with 8 cores (residing in a single node), 14.1 with 16 cores (residing in two nodes), and 26.4 with 32 cores (residing in four nodes). We have compared the performance of our sequential algorithm with TPA (FCED) and found that our algorithm outperforms the previous one. The accuracy is the same as that of this previous best-known algorithm.

Bursts and Heavy Tails in Temporal and Sequential Dynamics of Foraging Decisions

PubMed Central

Jung, Kanghoon; Jang, Hyeran; Kralik, Jerald D.; Jeong, Jaeseung

2014-01-01

A fundamental understanding of behavior requires predicting when and what an individual will choose. However, the actual temporal and sequential dynamics of successive choices made among multiple alternatives remain unclear. In the current study, we tested the hypothesis that there is a general bursting property in both the timing and sequential patterns of foraging decisions. We conducted a foraging experiment in which rats chose among four different foods over a continuous two-week time period. Regarding when choices were made, we found bursts of rapidly occurring actions, separated by time-varying inactive periods, partially based on a circadian rhythm. Regarding what was chosen, we found sequential dynamics in affective choices characterized by two key features: (a) a highly biased choice distribution; and (b) preferential attachment, in which the animals were more likely to choose what they had previously chosen. To capture the temporal dynamics, we propose a dual-state model consisting of active and inactive states. We also introduce a satiation-attainment process for bursty activity, and a non-homogeneous Poisson process for longer inactivity between bursts. For the sequential dynamics, we propose a dual-control model consisting of goal-directed and habit systems, based on outcome valuation and choice history, respectively. This study provides insights into how the bursty nature of behavior emerges from the interaction of different underlying systems, leading to heavy tails in the distribution of behavior over time and choices. PMID:25122498

Location Prediction Based on Transition Probability Matrices Constructing from Sequential Rules for Spatial-Temporal K-Anonymity Dataset

PubMed Central

Liu, Zhao; Zhu, Yunhong; Wu, Chenxue

2016-01-01

Spatial-temporal k-anonymity has become a mainstream approach among techniques for protection of users’ privacy in location-based services (LBS) applications, and has been applied to several variants such as LBS snapshot queries and continuous queries. Analyzing large-scale spatial-temporal anonymity sets may benefit several LBS applications. In this paper, we propose two location prediction methods based on transition probability matrices constructing from sequential rules for spatial-temporal k-anonymity dataset. First, we define single-step sequential rules mined from sequential spatial-temporal k-anonymity datasets generated from continuous LBS queries for multiple users. We then construct transition probability matrices from mined single-step sequential rules, and normalize the transition probabilities in the transition matrices. Next, we regard a mobility model for an LBS requester as a stationary stochastic process and compute the n-step transition probability matrices by raising the normalized transition probability matrices to the power n. Furthermore, we propose two location prediction methods: rough prediction and accurate prediction. The former achieves the probabilities of arriving at target locations along simple paths those include only current locations, target locations and transition steps. By iteratively combining the probabilities for simple paths with n steps and the probabilities for detailed paths with n-1 steps, the latter method calculates transition probabilities for detailed paths with n steps from current locations to target locations. Finally, we conduct extensive experiments, and correctness and flexibility of our proposed algorithm have been verified. PMID:27508502

Work-Family Conflict and Mental Health Among Female Employees: A Sequential Mediation Model via Negative Affect and Perceived Stress.

PubMed

Zhou, Shiyi; Da, Shu; Guo, Heng; Zhang, Xichao

2018-01-01

After the implementation of the universal two-child policy in 2016, more and more working women have found themselves caught in the dilemma of whether to raise a baby or be promoted, which exacerbates work-family conflicts among Chinese women. Few studies have examined the mediating effect of negative affect. The present study combined the conservation of resources model and affective events theory to examine the sequential mediating effect of negative affect and perceived stress in the relationship between work-family conflict and mental health. A valid sample of 351 full-time Chinese female employees was recruited in this study, and participants voluntarily answered online questionnaires. Pearson correlation analysis, structural equation modeling, and multiple mediation analysis were used to examine the relationships between work-family conflict, negative affect, perceived stress, and mental health in full-time female employees. We found that women's perceptions of both work-to-family conflict and family-to-work conflict were significant negatively related to mental health. Additionally, the results showed that negative affect and perceived stress were negatively correlated with mental health. The 95% confidence intervals indicated the sequential mediating effect of negative affect and stress in the relationship between work-family conflict and mental health was significant, which supported the hypothesized sequential mediation model. The findings suggest that work-family conflicts affected the level of self-reported mental health, and this relationship functioned through the two sequential mediators of negative affect and perceived stress.

Carbon Nanotube Growth Rate Regression using Support Vector Machines and Artificial Neural Networks

DTIC Science & Technology

2014-03-27

intensity D peak. Reprinted with permission from [38]. The SVM classifier is trained using custom written Java code leveraging the Sequential Minimal...Society Encog is a machine learning framework for Java , C++ and .Net applications that supports Bayesian Networks, Hidden Markov Models, SVMs and ANNs [13...SVM classifiers are trained using Weka libraries and leveraging custom written Java code. The data set is created as an Attribute Relationship File

Advanced statistics: linear regression, part I: simple linear regression.

PubMed

Marill, Keith A

2004-01-01

Simple linear regression is a mathematical technique used to model the relationship between a single independent predictor variable and a single dependent outcome variable. In this, the first of a two-part series exploring concepts in linear regression analysis, the four fundamental assumptions and the mechanics of simple linear regression are reviewed. The most common technique used to derive the regression line, the method of least squares, is described. The reader will be acquainted with other important concepts in simple linear regression, including: variable transformations, dummy variables, relationship to inference testing, and leverage. Simplified clinical examples with small datasets and graphic models are used to illustrate the points. This will provide a foundation for the second article in this series: a discussion of multiple linear regression, in which there are multiple predictor variables.

Cadmium partition in river sediments from an area affected by mining activities.

PubMed

Vasile, Georgiana D; Vlădescu, Luminiţa

2010-08-01

In this paper, the cadmium distribution in Certej River sediments in an area seriously affected by intense mining activities has been studied. The main objective of this study was the evaluation of partition of this metal into different operational defined fractions by sequential extractions. Community Bureau of Reference (BCR) sequential extraction was used to isolate different fractions. The sediment quality was assessed both upstream and downstream the pollution input points, along the Certej River, in order to reveal a possible accumulation of cadmium in sediments and the seasonal changes in cadmium concentrations in BCR sediment phases. Our results reveal that most of the cadmium content is divided between both the soluble and iron and manganese hydrated oxide fractions. Based on total cadmium concentrations in sediments, the enrichment factors were estimated using aluminum as normalizing element and the regression curve Cd/Al corresponding to the geochemical background of the studied area.

Remote sensing data with the conditional latin hypercube sampling and geostatistical approach to delineate landscape changes induced by large chronological physical disturbances.

PubMed

Lin, Yu-Pin; Chu, Hone-Jay; Wang, Cheng-Long; Yu, Hsiao-Hsuan; Wang, Yung-Chieh

2009-01-01

This study applies variogram analyses of normalized difference vegetation index (NDVI) images derived from SPOT HRV images obtained before and after the ChiChi earthquake in the Chenyulan watershed, Taiwan, as well as images after four large typhoons, to delineate the spatial patterns, spatial structures and spatial variability of landscapes caused by these large disturbances. The conditional Latin hypercube sampling approach was applied to select samples from multiple NDVI images. Kriging and sequential Gaussian simulation with sufficient samples were then used to generate maps of NDVI images. The variography of NDVI image results demonstrate that spatial patterns of disturbed landscapes were successfully delineated by variogram analysis in study areas. The high-magnitude Chi-Chi earthquake created spatial landscape variations in the study area. After the earthquake, the cumulative impacts of typhoons on landscape patterns depended on the magnitudes and paths of typhoons, but were not always evident in the spatiotemporal variability of landscapes in the study area. The statistics and spatial structures of multiple NDVI images were captured by 3,000 samples from 62,500 grids in the NDVI images. Kriging and sequential Gaussian simulation with the 3,000 samples effectively reproduced spatial patterns of NDVI images. However, the proposed approach, which integrates the conditional Latin hypercube sampling approach, variogram, kriging and sequential Gaussian simulation in remotely sensed images, efficiently monitors, samples and maps the effects of large chronological disturbances on spatial characteristics of landscape changes including spatial variability and heterogeneity.

Comparative effectiveness of adding weight control simultaneously or sequentially to smoking cessation quitlines: study protocol of a randomized controlled trial.

PubMed

Bush, Terry; Lovejoy, Jennifer; Javitz, Harold; Magnusson, Brooke; Torres, Alula Jimenez; Mahuna, Stacey; Benedict, Cody; Wassum, Ken; Spring, Bonnie

2016-07-22

Prevalence of multiple health risk behaviors is growing, and obesity and smoking are costly. Weight gain associated with quitting smoking is common and can interfere with quit success. Efficacy of adding weight management to tobacco cessation treatment has been tested with women in group sessions over an extended period of time, but has never been tested in real-world settings with men and women seeking help to quit. This paper describes the Best Quit study which tests the effectiveness of delivering tobacco and weight control interventions via existing quitline infrastructures. Eligible and consenting smokers (n = 2550) who call a telephone quitline will be randomized to one of three groups; the standard quitline or standard quitline plus a weight management program added either simultaneously or sequentially to the tobacco program. The study aims to test: 1) the effectiveness of the combined intervention on smoking cessation and weight, 2) the cost-effectiveness of the combined intervention on cessation and weight and 3) theoretically pre-specified mediators of treatment effects on cessation: reduced weight concerns, increased outcome expectancies about quitting and improved self-efficacy about quitting without weight gain. Baseline, 6 month and 12 month data will be analyzed using multivariate statistical analyses and groups will be compared on treatment adherence, quit rates and change in weight among abstinent participants. To determine if the association between group assignment and primary outcomes (30-day abstinence and change in weight at 6 months) is moderated by pre-determined baseline and process measures, interaction terms will be included in the regression models and their significance assessed. This study will generate information to inform whether adding weight management to a tobacco cessation intervention delivered by phone, mail and web for smokers seeking help to quit will help or harm quit rates and whether a simultaneous or sequential approach is better at increasing abstinence and reducing weight gain post quit. If proven effective, the combined intervention could be disseminated across the U.S. through quitlines and could encourage additional smokers who have not sought cessation treatment for fear of gaining weight to make quit attempts. Clinicaltrials.gov NCT01867983 . Registered: May 30, 2013.

Multifocal laser surgery: cutting enhancement by hydrodynamic interactions between cavitation bubbles.

PubMed

Toytman, I; Silbergleit, A; Simanovski, D; Palanker, D

2010-10-01

Transparent biological tissues can be precisely dissected with ultrafast lasers using optical breakdown in the tight focal zone. Typically, tissues are cut by sequential application of pulses, each of which produces a single cavitation bubble. We investigate the hydrodynamic interactions between simultaneous cavitation bubbles originating from multiple laser foci. Simultaneous expansion and collapse of cavitation bubbles can enhance the cutting efficiency, by increasing the resulting deformations in tissue, and the associated rupture zone. An analytical model of the flow induced by the bubbles is presented and experimentally verified. The threshold strain of the material rupture is measured in a model tissue. Using the computational model and the experimental value of the threshold strain one can compute the shape of the rupture zone in tissue resulting from application of multiple bubbles. With the threshold strain of 0.7 two simultaneous bubbles produce a continuous cut when applied at the distance 1.35 times greater than that required in sequential approach. Simultaneous focusing of the laser in multiple spots along the line of intended cut can extend this ratio to 1.7. Counterpropagating jets forming during collapse of two bubbles in materials with low viscosity can further extend the cutting zone-up to approximately a factor of 1.5.

Pharmacokinetics and Safety of Intravenous Murepavadin Infusion in Healthy Adult Subjects Administered Single and Multiple Ascending Doses.

PubMed

Wach, Achim; Dembowsky, Klaus; Dale, Glenn E

2018-04-01

Murepavadin is the first in class of the outer membrane protein-targeting antibiotics (OMPTA) and a pathogen-specific peptidomimetic antibacterial with a novel, nonlytic mechanism of action targeting Pseudomonas aeruginosa Murepavadin is being developed for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). The pharmacokinetics (PK) and safety of single and multiple doses of murepavadin were investigated in healthy male subjects. Part A of the study was a double-blind, randomized, placebo-controlled, single-ascending-dose investigation in 10 sequential cohorts where each cohort comprised 6 healthy male subjects; 4 subjects were randomized to murepavadin, and 2 subjects were randomized to placebo. Part B was a double-blind, randomized, placebo-controlled, multiple-ascending-dose investigation in 3 sequential cohorts. After a single dose of murepavadin, the geometric mean half-life (2.52 to 5.30 h), the total clearance (80.1 to 114 ml/h/kg), and the volume of distribution (415 to 724 ml/kg) were consistent across dose levels. The pharmacokinetics of the dosing regimens evaluated were dose proportional and linear. Murepavadin was well tolerated, adverse events were transient and generally mild, and no dose-limiting toxicity was identified. Copyright © 2018 American Society for Microbiology.

Deciding the liveness for a subclass of weighted Petri nets based on structurally circular wait

NASA Astrophysics Data System (ADS)

Liu, GuanJun; Chen, LiJing

2016-05-01

Weighted Petri nets as a kind of formal language are widely used to model and verify discrete event systems related to resource allocation like flexible manufacturing systems. System of Simple Sequential Processes with Multi-Resources (S3PMR, a subclass of weighted Petri nets and an important extension to the well-known System of Simple Sequential Processes with Resources, can model many discrete event systems in which (1) multiple processes may run in parallel and (2) each execution step of each process may use multiple units from multiple resource types. This paper gives a necessary and sufficient condition for the liveness of S3PMR. A new structural concept called Structurally Circular Wait (SCW) is proposed for S3PMR. Blocking Marking (BM) associated with an SCW is defined. It is proven that a marked S3PMR is live if and only if each SCW has no BM. We use an example of multi-processor system-on-chip to show that SCW and BM can precisely characterise the (partial) deadlocks for S3PMR. Simultaneously, two examples are used to show the advantages of SCW in preventing deadlocks of S3PMR. These results are significant for the further research on dealing with the deadlock problem.

A Novel System for Simultaneous or Sequential Integration of Multiple Gene-Loading Vectors into a Defined Site of a Human Artificial Chromosome

PubMed Central

Suzuki, Teruhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

2014-01-01

Human artificial chromosomes (HACs) are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV) into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system) via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming. PMID:25303219

A novel system for simultaneous or sequential integration of multiple gene-loading vectors into a defined site of a human artificial chromosome.

PubMed

Suzuki, Teruhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

2014-01-01

Human artificial chromosomes (HACs) are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV) into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system) via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming.

Dual tracer imaging of SPECT and PET probes in living mice using a sequential protocol

PubMed Central

Chapman, Sarah E; Diener, Justin M; Sasser, Todd A; Correcher, Carlos; González, Antonio J; Avermaete, Tony Van; Leevy, W Matthew

2012-01-01

Over the past 20 years, multimodal imaging strategies have motivated the fusion of Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scans with an X-ray computed tomography (CT) image to provide anatomical information, as well as a framework with which molecular and functional images may be co-registered. Recently, pre-clinical nuclear imaging technology has evolved to capture multiple SPECT or multiple PET tracers to further enhance the information content gathered within an imaging experiment. However, the use of SPECT and PET probes together, in the same animal, has remained a challenge. Here we describe a straightforward method using an integrated trimodal imaging system and a sequential dosing/acquisition protocol to achieve dual tracer imaging with 99mTc and 18F isotopes, along with anatomical CT, on an individual specimen. Dosing and imaging is completed so that minimal animal manipulations are required, full trimodal fusion is conserved, and tracer crosstalk including down-scatter of the PET tracer in SPECT mode is avoided. This technique will enhance the ability of preclinical researchers to detect multiple disease targets and perform functional, molecular, and anatomical imaging on individual specimens to increase the information content gathered within longitudinal in vivo studies. PMID:23145357

Noninvasive spectral imaging of skin chromophores based on multiple regression analysis aided by Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Nishidate, Izumi; Wiswadarma, Aditya; Hase, Yota; Tanaka, Noriyuki; Maeda, Takaaki; Niizeki, Kyuichi; Aizu, Yoshihisa

2011-08-01

In order to visualize melanin and blood concentrations and oxygen saturation in human skin tissue, a simple imaging technique based on multispectral diffuse reflectance images acquired at six wavelengths (500, 520, 540, 560, 580 and 600nm) was developed. The technique utilizes multiple regression analysis aided by Monte Carlo simulation for diffuse reflectance spectra. Using the absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are deduced numerically in advance, while oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments with human skin of the human hand during upper limb occlusion and of the inner forearm exposed to UV irradiation demonstrated the ability of the method to evaluate physiological reactions of human skin tissue.

Using the Coefficient of Determination "R"[superscript 2] to Test the Significance of Multiple Linear Regression

ERIC Educational Resources Information Center

Quinino, Roberto C.; Reis, Edna A.; Bessegato, Lupercio F.

2013-01-01

This article proposes the use of the coefficient of determination as a statistic for hypothesis testing in multiple linear regression based on distributions acquired by beta sampling. (Contains 3 figures.)

Attentional effects on orientation judgements are dependent on memory consolidation processes.

PubMed

Haskell, Christie; Anderson, Britt

2016-11-01

Are the effects of memory and attention on perception synergistic, antagonistic, or independent? Tested separately, memory and attention have been shown to affect the accuracy of orientation judgements. When multiple stimuli are presented sequentially versus simultaneously, error variance is reduced. When a target is validly cued, precision is increased. What if they are manipulated together? We combined memory and attention manipulations in an orientation judgement task to answer this question. Two circular gratings were presented sequentially or simultaneously. On some trials a brief luminance cue preceded the stimuli. Participants were cued to report the orientation of one of the two gratings by rotating a response grating. We replicated the finding that error variance is reduced on sequential trials. Critically, we found interacting effects of memory and attention. Valid cueing reduced the median, absolute error only when two stimuli appeared together and improved it to the level of performance on uncued sequential trials, whereas invalid cueing always increased error. This effect was not mediated by cue predictiveness; however, predictive cues reduced the standard deviation of the error distribution, whereas nonpredictive cues reduced "guessing". Our results suggest that, when the demand on memory is greater than a single stimulus, attention is a bottom-up process that prioritizes stimuli for consolidation. Thus attention and memory are synergistic.

The type of culture medium and the duration of in vitro culture do not influence birthweight of ART singletons.

PubMed

De Vos, A; Janssens, R; Van de Velde, H; Haentjens, P; Bonduelle, M; Tournaye, H; Verheyen, G

2015-01-01

Does the type of in vitro culture medium or the duration of in vitro culture influence singleton birthweight after IVF/ICSI treatment? In a comparison of two culture media, neither the medium nor the duration of culture (Day 3 versus Day 5 blastocyst transfer) had any effect on mean singleton birthweight. Previous studies indicated that in vitro culture of human embryos may affect birthweight of live born singletons. Both the type of culture medium and the duration of culture may be implicated. However, these studies are small and report conflicting results. A large retrospective analysis was performed including all singleton live births after transferring fresh Day 3 or Day 5 embryos. IVF and ICSI cycles performed between April 2004 and December 2009 at a tertiary care centre were included for analysis. A total of 2098 singleton live births resulting from singleton pregnancies were included for analysis. Two different sequential embryo culture media were concurrently used in an alternating way: Medicult (n = 1388) and Vitrolife (n = 710). Maternal age, maternal and paternal BMI, maternal parity, maternal smoking, main cause of infertility, cycle rank, stimulation protocol, method of fertilization (IVF or ICSI), time in culture and number of embryos transferred were taken into account. Embryo transfers were performed either on Day 3 (n = 1234) or on Day 5 (n = 864). Singleton birthweight was the primary outcome parameter. Gestational age and gender of the newborn were accounted for in the multiple regression analysis. No significant differences in mean singleton birthweight were observed between the two culture media: Medicult 3222 g (±15 SE) and Vitrolife 3251 g (±21 SE) (P = 0.264). The mean singleton birthweight was not different between Day 3 embryo transfers (3219 ± 16 g) and Day 5 blastocyst transfers (3250 ± 19 g; P = 0.209). Multiple regression analysis controlling for potential maternal, paternal, treatment and newborn confounders confirmed the non-significant differences in mean singleton birthweight between the two culture media. Likewise, the adjusted mean singleton birthweight was not different according to the duration of in vitro culture (P = 0.521). The conclusions are limited by its retrospective design; however, the two different sequential culture systems were used in an alternating way during the same time period. Pregnancy-associated factors possibly influencing birthweight (such as diabetes, hypertension, pre-eclampsia) were not included in the analysis. This large retrospective study does not support earlier concerns that both the type of culture medium and the duration of embryo culture influence singleton birthweight. However, a continuous surveillance of human embryo culture procedures (medium type, culture duration and other culture conditions) should remain a priority within assisted reproduction technology. None. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Identifying maternal and infant factors associated with newborn size in rural Bangladesh by partial least squares (PLS) regression analysis

PubMed Central

Rahman, Md. Jahanur; Shamim, Abu Ahmed; Klemm, Rolf D. W.; Labrique, Alain B.; Rashid, Mahbubur; Christian, Parul; West, Keith P.

2017-01-01

Birth weight, length and circumferences of the head, chest and arm are key measures of newborn size and health in developing countries. We assessed maternal socio-demographic factors associated with multiple measures of newborn size in a large rural population in Bangladesh using partial least squares (PLS) regression method. PLS regression, combining features from principal component analysis and multiple linear regression, is a multivariate technique with an ability to handle multicollinearity while simultaneously handling multiple dependent variables. We analyzed maternal and infant data from singletons (n = 14,506) born during a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural northwest Bangladesh. PLS regression results identified numerous maternal factors (parity, age, early pregnancy MUAC, living standard index, years of education, number of antenatal care visits, preterm delivery and infant sex) significantly (p<0.001) associated with newborn size. Among them, preterm delivery had the largest negative influence on newborn size (Standardized β = -0.29 − -0.19; p<0.001). Scatter plots of the scores of first two PLS components also revealed an interaction between newborn sex and preterm delivery on birth size. PLS regression was found to be more parsimonious than both ordinary least squares regression and principal component regression. It also provided more stable estimates than the ordinary least squares regression and provided the effect measure of the covariates with greater accuracy as it accounts for the correlation among the covariates and outcomes. Therefore, PLS regression is recommended when either there are multiple outcome measurements in the same study, or the covariates are correlated, or both situations exist in a dataset. PMID:29261760

Identifying maternal and infant factors associated with newborn size in rural Bangladesh by partial least squares (PLS) regression analysis.

PubMed

Kabir, Alamgir; Rahman, Md Jahanur; Shamim, Abu Ahmed; Klemm, Rolf D W; Labrique, Alain B; Rashid, Mahbubur; Christian, Parul; West, Keith P

2017-01-01

Birth weight, length and circumferences of the head, chest and arm are key measures of newborn size and health in developing countries. We assessed maternal socio-demographic factors associated with multiple measures of newborn size in a large rural population in Bangladesh using partial least squares (PLS) regression method. PLS regression, combining features from principal component analysis and multiple linear regression, is a multivariate technique with an ability to handle multicollinearity while simultaneously handling multiple dependent variables. We analyzed maternal and infant data from singletons (n = 14,506) born during a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural northwest Bangladesh. PLS regression results identified numerous maternal factors (parity, age, early pregnancy MUAC, living standard index, years of education, number of antenatal care visits, preterm delivery and infant sex) significantly (p<0.001) associated with newborn size. Among them, preterm delivery had the largest negative influence on newborn size (Standardized β = -0.29 - -0.19; p<0.001). Scatter plots of the scores of first two PLS components also revealed an interaction between newborn sex and preterm delivery on birth size. PLS regression was found to be more parsimonious than both ordinary least squares regression and principal component regression. It also provided more stable estimates than the ordinary least squares regression and provided the effect measure of the covariates with greater accuracy as it accounts for the correlation among the covariates and outcomes. Therefore, PLS regression is recommended when either there are multiple outcome measurements in the same study, or the covariates are correlated, or both situations exist in a dataset.

Sequential addition of short DNA oligos in DNA-polymerase-based synthesis reactions

DOEpatents

Gardner, Shea N; Mariella, Jr., Raymond P; Christian, Allen T; Young, Jennifer A; Clague, David S

2013-06-25

A method of preselecting a multiplicity of DNA sequence segments that will comprise the DNA molecule of user-defined sequence, separating the DNA sequence segments temporally, and combining the multiplicity of DNA sequence segments with at least one polymerase enzyme wherein the multiplicity of DNA sequence segments join to produce the DNA molecule of user-defined sequence. Sequence segments may be of length n, where n is an odd integer. In one embodiment the length of desired hybridizing overlap is specified by the user and the sequences and the protocol for combining them are guided by computational (bioinformatics) predictions. In one embodiment sequence segments are combined from multiple reading frames to span the same region of a sequence, so that multiple desired hybridizations may occur with different overlap lengths.

Long-term results and quality of life of patients undergoing sequential surgical treatment for severe acute pancreatitis complicated by infected pancreatic necrosis.

PubMed

Cinquepalmi, Lorenza; Boni, Luigi; Dionigi, Gianlorenzo; Rovera, Francesca; Diurni, Mario; Benevento, Angelo; Dionigi, Renzo

2006-01-01

Infected pancreatic necrosis (IPN) is one of the most severe complications of acute pancreatitis (AP). Sequential surgical debridement represents one of the most effective treatments in terms of morbidity and mortality. The aim of this paper is to describe the quality of life and long-term results (e.g., nutritional, muscular, and pancreatic function) of patients treated by sequential necrosectomy at the Department of Surgery of the University of Insubria (Varese, Italy). Data were collected on patients undergoing sequential surgical debridement as treatment for IPN. The severity of AP was evaluated using the Ranson criteria, the Acute Physiology and Chronic Health Evaluation (APACHE II) Score, and the Sepsis Score, as well as the extent of necrosis. The surgical approach was through a midline or subcostal laparotomy, followed by exploration of the peritoneal cavity, wide debridement, and peritoneal lavage. The abdomen was either left open or closed partially with a surgical zipper, with multiple re-laparotomies scheduled until debridement of necrotic tissue was complete. The long-term evaluation focused on late morbidity, performance status, and abdominal wall function. In the majority of patients (68%), mixed flora were isolated. Pseudomonas aeruginosa was the microorganism identified most commonly (59%), often associated with Candida albicans or C. glabrata. The mean total hospital stay was 71+/-38 days (range 13-146 days), of which 24+/-19 days (range 0-66 days) were in the intensive care unit. Eight patients died, the deaths being caused by multiple organ dysfunction syndrome in seven patients and hemorrhage from the splenic artery in one. Normal exocrine and endocrine pancreatic function was observed in 28 patients (88%). At discharge, four patients had steatorrhea, which was temporary. Eight patients (23%) developed pancreatic pseudocysts, and in six, cystogastostomy was performed. Most patients (29/32, 91%) developed a post-operative hernia, but only five required surgical repair. All patients had a Short Form (SF)-36 score>60%, and 20 of the 32 patients (68%) had scores>70-80% (good quality of life). The worst scores were related to alcoholic pancreatitis. The degree of pancreatic failure (exocrine and endocrine function) is not related to the amount of pancreatic necrosis. Even with a need for repeated laparotomy and multiple surgical procedures, the abdominal wall capacity as well as long-term quality of life remain excellent.

One-pot growth of two-dimensional lateral heterostructures via sequential edge-epitaxy

NASA Astrophysics Data System (ADS)

Sahoo, Prasana K.; Memaran, Shahriar; Xin, Yan; Balicas, Luis; Gutiérrez, Humberto R.

2018-01-01

Two-dimensional heterojunctions of transition-metal dichalcogenides have great potential for application in low-power, high-performance and flexible electro-optical devices, such as tunnelling transistors, light-emitting diodes, photodetectors and photovoltaic cells. Although complex heterostructures have been fabricated via the van der Waals stacking of different two-dimensional materials, the in situ fabrication of high-quality lateral heterostructures with multiple junctions remains a challenge. Transition-metal-dichalcogenide lateral heterostructures have been synthesized via single-step, two-step or multi-step growth processes. However, these methods lack the flexibility to control, in situ, the growth of individual domains. In situ synthesis of multi-junction lateral heterostructures does not require multiple exchanges of sources or reactors, a limitation in previous approaches as it exposes the edges to ambient contamination, compromises the homogeneity of domain size in periodic structures, and results in long processing times. Here we report a one-pot synthetic approach, using a single heterogeneous solid source, for the continuous fabrication of lateral multi-junction heterostructures consisting of monolayers of transition-metal dichalcogenides. The sequential formation of heterojunctions is achieved solely by changing the composition of the reactive gas environment in the presence of water vapour. This enables selective control of the water-induced oxidation and volatilization of each transition-metal precursor, as well as its nucleation on the substrate, leading to sequential edge-epitaxy of distinct transition-metal dichalcogenides. Photoluminescence maps confirm the sequential spatial modulation of the bandgap, and atomic-resolution images reveal defect-free lateral connectivity between the different transition-metal-dichalcogenide domains within a single crystal structure. Electrical transport measurements revealed diode-like responses across the junctions. Our new approach offers greater flexibility and control than previous methods for continuous growth of transition-metal-dichalcogenide-based multi-junction lateral heterostructures. These findings could be extended to other families of two-dimensional materials, and establish a foundation for the development of complex and atomically thin in-plane superlattices, devices and integrated circuits.

A retrospective study on sequential desensitization-rechallenge for antituberculosis drug allergy

PubMed Central

Chia, Faith Li-Ann; Tan, Sze-Chin; Tan, Teck-Choon; Leong, Khai-Pang; Tan, Justina Wei-Lyn; Tang, Chwee-Ying; Hou, Jin-Feng; Chan, Grace Yin-Lai; Chng, Hiok-Hee

2014-01-01

Background Antituberculosis (anti-TB) drug allergy often involves multiple concurrently administered drugs which subsequently need to be reinitiated as no better alternatives exist. Objective To describe the results of tailored sequential desensitization-rechallenge (D-R) for anti-TB drug allergy. Methods Consecutive patients who had undergone D-R to anti-TB drugs between 1 September 1997 and 31 January 2012 were recruited. Following resolution of the acute reaction, anti-TB drug was restarted at 1:6,000 to 1:3 of the final daily dose (FDD), with gradual single or multiple step daily dose escalation to the FDD. Subsequent drugs were sequentially added ≥3 days later when the preceding drug was tolerated. Full blood count and liver function tests were monitored prior to addition of each new drug. Results There were 11 patients of whom 10 were male, predominantly Chinese (8 patients). Regimens comprised at least 3 drugs: isoniazid (INH), rifampicin (RIF), ethambutol (EMB), pyrazinamide (PZA), or streptomycin. All patients had nonimmediate reactions, with cutaneous eruptions, where maculopapular exanthema (MPE) was the most common (8 patients). Drug-induced hypersensitivity syndrome (DIHS) occurred in 6 patients, and Stevens Johnson syndrome (SJS) in 2 patients. D-R to INH was successful in 7/9 patients (77.8%) and to RIF/EMB/PZA/streptomycin in all. Of the 2 patients who failed INH D-R, 1 developed fever and MPE on day 3, the other MPE on day 8. D-R with INH and RIF respectively was successful in 2 patients with SJS. Among DIHS patients, 1 failed D-R with INH (fever and MPE on day 3). There were 23/25 (92%) successful D-R among the 11 patients. All patients completed TB treatment of ≥5 months' duration with no cases of drug-resistant TB. Conclusion Tailored sequential TB drug D-R is successful where no better alternative therapies are available, with careful dose escalation and close monitoring, and after a careful risk-benefit assessment. PMID:25097851

Sequential Bayesian Geostatistical Inversion and Evaluation of Combined Data Worth for Aquifer Characterization at the Hanford 300 Area

NASA Astrophysics Data System (ADS)

Murakami, H.; Chen, X.; Hahn, M. S.; Over, M. W.; Rockhold, M. L.; Vermeul, V.; Hammond, G. E.; Zachara, J. M.; Rubin, Y.

2010-12-01

Subsurface characterization for predicting groundwater flow and contaminant transport requires us to integrate large and diverse datasets in a consistent manner, and quantify the associated uncertainty. In this study, we sequentially assimilated multiple types of datasets for characterizing a three-dimensional heterogeneous hydraulic conductivity field at the Hanford 300 Area. The datasets included constant-rate injection tests, electromagnetic borehole flowmeter tests, lithology profile and tracer tests. We used the method of anchored distributions (MAD), which is a modular-structured Bayesian geostatistical inversion method. MAD has two major advantages over the other inversion methods. First, it can directly infer a joint distribution of parameters, which can be used as an input in stochastic simulations for prediction. In MAD, in addition to typical geostatistical structural parameters, the parameter vector includes multiple point values of the heterogeneous field, called anchors, which capture local trends and reduce uncertainty in the prediction. Second, MAD allows us to integrate the datasets sequentially in a Bayesian framework such that it updates the posterior distribution, as a new dataset is included. The sequential assimilation can decrease computational burden significantly. We applied MAD to assimilate different combinations of the datasets, and then compared the inversion results. For the injection and tracer test assimilation, we calculated temporal moments of pressure build-up and breakthrough curves, respectively, to reduce the data dimension. A massive parallel flow and transport code PFLOTRAN is used for simulating the tracer test. For comparison, we used different metrics based on the breakthrough curves not used in the inversion, such as mean arrival time, peak concentration and early arrival time. This comparison intends to yield the combined data worth, i.e. which combination of the datasets is the most effective for a certain metric, which will be useful for guiding the further characterization effort at the site and also the future characterization projects at the other sites.

Associations between maternal long-chain polyunsaturated fatty acid concentrations and child cognition at 7 years of age: The MEFAB birth cohort.

PubMed

Brouwer-Brolsma, E M; van de Rest, O; Godschalk, R; Zeegers, M P A; Gielen, M; de Groot, R H M

2017-11-01

Concentrations of the fish fatty acids EPA and DHA are low among Dutch women of reproductive age. As the human brain incorporates high concentrations of these fatty acids in utero, particularly during third trimester of gestation, these low EPA and DHA concentrations may have adverse consequences for fetal brain development and functioning. Analyses were conducted using longitudinal observational data of 292 mother-child pairs participating in the MEFAB cohort. Maternal AA, DHA, and EPA were determined in plasma phospholipids - obtained in three trimesters - by gas-liquid chromatography. Cognitive function was assessed at 7 years of age, using the Kaufman Assessment Battery for Children, resulting in three main outcome parameters: sequential processing (short-term memory), simultaneous processing (problem-solving skills), and the mental processing composite score. Spline regression and linear regression analyses were used to analyse the data, while adjusting for potential relevant covariates. Only 2% of the children performed more than one SD below the mental processing composite norm score. Children with lower test scores (<25%) were more likely to have a younger mother with a higher pre-gestational BMI, less likely to be breastfed, and more likely to be born with a lower birth weight, compared to children with higher test scores (≥25%). Fully-adjusted linear regression models did not show associations of maternal AA, DHA, or EPA status during any of the pregnancy trimesters with childhood sequential and simultaneous processing. Maternal fatty acid status during pregnancy was not associated with cognitive performance in Dutch children at age 7. Copyright © 2017 Elsevier Ltd. All rights reserved.

The M Word: Multicollinearity in Multiple Regression.

ERIC Educational Resources Information Center

Morrow-Howell, Nancy

1994-01-01

Notes that existence of substantial correlation between two or more independent variables creates problems of multicollinearity in multiple regression. Discusses multicollinearity problem in social work research in which independent variables are usually intercorrelated. Clarifies problems created by multicollinearity, explains detection of…

[Prediction model of health workforce and beds in county hospitals of Hunan by multiple linear regression].

PubMed

Ling, Ru; Liu, Jiawang

2011-12-01

To construct prediction model for health workforce and hospital beds in county hospitals of Hunan by multiple linear regression. We surveyed 16 counties in Hunan with stratified random sampling according to uniform questionnaires,and multiple linear regression analysis with 20 quotas selected by literature view was done. Independent variables in the multiple linear regression model on medical personnels in county hospitals included the counties' urban residents' income, crude death rate, medical beds, business occupancy, professional equipment value, the number of devices valued above 10 000 yuan, fixed assets, long-term debt, medical income, medical expenses, outpatient and emergency visits, hospital visits, actual available bed days, and utilization rate of hospital beds. Independent variables in the multiple linear regression model on county hospital beds included the the population of aged 65 and above in the counties, disposable income of urban residents, medical personnel of medical institutions in county area, business occupancy, the total value of professional equipment, fixed assets, long-term debt, medical income, medical expenses, outpatient and emergency visits, hospital visits, actual available bed days, utilization rate of hospital beds, and length of hospitalization. The prediction model shows good explanatory and fitting, and may be used for short- and mid-term forecasting.

Linear and nonlinear regression techniques for simultaneous and proportional myoelectric control.

PubMed

Hahne, J M; Biessmann, F; Jiang, N; Rehbaum, H; Farina, D; Meinecke, F C; Muller, K-R; Parra, L C

2014-03-01

In recent years the number of active controllable joints in electrically powered hand-prostheses has increased significantly. However, the control strategies for these devices in current clinical use are inadequate as they require separate and sequential control of each degree-of-freedom (DoF). In this study we systematically compare linear and nonlinear regression techniques for an independent, simultaneous and proportional myoelectric control of wrist movements with two DoF. These techniques include linear regression, mixture of linear experts (ME), multilayer-perceptron, and kernel ridge regression (KRR). They are investigated offline with electro-myographic signals acquired from ten able-bodied subjects and one person with congenital upper limb deficiency. The control accuracy is reported as a function of the number of electrodes and the amount and diversity of training data providing guidance for the requirements in clinical practice. The results showed that KRR, a nonparametric statistical learning method, outperformed the other methods. However, simple transformations in the feature space could linearize the problem, so that linear models could achieve similar performance as KRR at much lower computational costs. Especially ME, a physiologically inspired extension of linear regression represents a promising candidate for the next generation of prosthetic devices.

All Together Now: Concurrent Learning of Multiple Structures in an Artificial Language

ERIC Educational Resources Information Center

Romberg, Alexa R.; Saffran, Jenny R.

2013-01-01

Natural languages contain many layers of sequential structure, from the distribution of phonemes within words to the distribution of phrases within utterances. However, most research modeling language acquisition using artificial languages has focused on only one type of distributional structure at a time. In two experiments, we investigated adult…

Undertaking Experiments in Social Sciences: Sequential, Multiple Time Series Designs for Consideration

ERIC Educational Resources Information Center

Phan, Huy P.; Ngu, Bing H.

2017-01-01

In social sciences, the use of stringent methodological approaches is gaining increasing emphasis. Researchers have recognized the limitations of cross-sectional, non-manipulative data in the study of causality. True experimental designs, in contrast, are preferred as they represent rigorous standards for achieving causal flows between variables.…

Hierarchical Modeling of Sequential Behavioral Data: Examining Complex Association Patterns in Mediation Models

ERIC Educational Resources Information Center

Dagne, Getachew A.; Brown, C. Hendricks; Howe, George W.

2007-01-01

This article presents new methods for modeling the strength of association between multiple behaviors in a behavioral sequence, particularly those involving substantively important interaction patterns. Modeling and identifying such interaction patterns becomes more complex when behaviors are assigned to more than two categories, as is the case…

Robustness of Ability Estimation to Multidimensionality in CAST with Implications to Test Assembly

ERIC Educational Resources Information Center

Zhang, Yanwei; Nandakumar, Ratna

2006-01-01

Computer Adaptive Sequential Testing (CAST) is a test delivery model that combines features of the traditional conventional paper-and-pencil testing and item-based computerized adaptive testing (CAT). The basic structure of CAST is a panel composed of multiple testlets adaptively administered to examinees at different stages. Current applications…

Numerically stable algorithm for combining census and sample estimates with the multivariate composite estimator

Treesearch

R. L. Czaplewski

2009-01-01

The minimum variance multivariate composite estimator is a relatively simple sequential estimator for complex sampling designs (Czaplewski 2009). Such designs combine a probability sample of expensive field data with multiple censuses and/or samples of relatively inexpensive multi-sensor, multi-resolution remotely sensed data. Unfortunately, the multivariate composite...

Nanomedicine for Early Disease Detection and Treatment

DTIC Science & Technology

2013-09-01

AD_________________ Award Number: W81XWH-11-1-0442 TITLE: Nanomedicine for early disease ...been developed to report and cure diseases . ESNM is prepared with multiple layers of polyelectrolytes, sequentially assembled on an inert gold...molecular characteristics of the patient and his/her specific diseased tissues with the treatment. In order to maximize therapeutic effects and

A Writing Intervention to Teach Simple Sentences and Descriptive Paragraphs to Adolescents with Writing Difficulties

ERIC Educational Resources Information Center

Datchuk, Shawn M.; Kubina, Richard M., Jr.

2017-01-01

The present study used a multiple-baseline, single-case experimental design to investigate the effects of a multicomponent intervention on construction of simple sentences and word sequences. The intervention entailed sequential delivery of sentence instruction and frequency building to a performance criterion and paragraph instruction.…

Adult Learners' Knowledge of Fraction Addition and Subtraction

ERIC Educational Resources Information Center

Muckridge, Nicole A.

2017-01-01

The purpose of this study was to examine adult developmental mathematics (ADM) students' knowledge of fraction addition and subtraction as it relates to their demonstrated fraction schemes and ability to disembed in multiplicative contexts with whole numbers. The study was conducted using a mixed methods sequential explanatory design. In the first…

Radiation Hardened Structured ASIC Platform with Compensation of Delay for Temperature and Voltage Variations for Multiple Redundant Temporal Voting Latch Technology

NASA Technical Reports Server (NTRS)

Ardalan, Sasan (Inventor)

2018-01-01

The invention relates to devices and methods of maintaining the current starved delay at a constant value across variations in voltage and temperature to increase the speed of operation of the sequential logic in the radiation hardened ASIC design.

New tracking implementation in the Deep Space Network

NASA Technical Reports Server (NTRS)

Berner, Jeff B.; Bryant, Scott H.

2001-01-01

As part of the Network Simplification Project, the tracking system of the Deep Space Network is being upgraded. This upgrade replaces the discrete logic sequential ranging system with a system that is based on commercial Digital Signal Processor boards. The new implementation allows both sequential and pseudo-noise types of ranging. The other major change is a modernization of the data formatting. Previously, there were several types of interfaces, delivering both intermediate data and processed data (called 'observables'). All of these interfaces were bit-packed blocks, which do not allow for easy expansion, and many of these interfaces required knowledge of the specific hardware implementations. The new interface supports four classes of data: raw (direct from the measuring equipment), derived (the observable data), interferometric (multiple antenna measurements), and filtered (data whose values depend on multiple measurements). All of the measurements are reported at the sky frequency or phase level, so that no knowledge of the actual hardware is required. The data is formatted into Standard Formatted Data Units, as defined by the Consultative Committee for Space Data Systems, so that expansion and cross-center usage is greatly enhanced.

Optimization of Multiple Related Negotiation through Multi-Negotiation Network

NASA Astrophysics Data System (ADS)

Ren, Fenghui; Zhang, Minjie; Miao, Chunyan; Shen, Zhiqi

In this paper, a Multi-Negotiation Network (MNN) and a Multi- Negotiation Influence Diagram (MNID) are proposed to optimally handle Multiple Related Negotiations (MRN) in a multi-agent system. Most popular, state-of-the-art approaches perform MRN sequentially. However, a sequential procedure may not optimally execute MRN in terms of maximizing the global outcome, and may even lead to unnecessary losses in some situations. The motivation of this research is to use a MNN to handle MRN concurrently so as to maximize the expected utility of MRN. Firstly, both the joint success rate and the joint utility by considering all related negotiations are dynamically calculated based on a MNN. Secondly, by employing a MNID, an agent's possible decision on each related negotiation is reflected by the value of expected utility. Lastly, through comparing expected utilities between all possible policies to conduct MRN, an optimal policy is generated to optimize the global outcome of MRN. The experimental results indicate that the proposed approach can improve the global outcome of MRN in a successful end scenario, and avoid unnecessary losses in an unsuccessful end scenario.

Physics Learning Styles in Higher Education

NASA Astrophysics Data System (ADS)

Loos, Rebecca; Ward, James

2012-03-01

Students in Physics learn in a variety ways depending on backgrounds and interests. This study proposes to evaluate how students in Physics learn using Howard Gardner's Theory of Multiple Intelligences. Physics utilizes numbers, conceptualization of models, observations and visualization skills, and the ability to understand and reflect on specific information. The main objective is to evaluate how Physics students learn specifically using spatial, visual and sequential approaches. This will be assessed by conducting a learning style survey provided by North Carolina State University (NCSU). The survey is completed online by the student after which the results are sent to NCSU. Students will print out the completed survey analysis for further evaluation. The NCSU results categorize students within five of ten learning styles. After the evaluation of Howard Gardner's Theory of Multiple Intelligences and the NCSU definitions of the ten learning styles, the NCSU sensing and visual learning styles will be defined as the Gardener's spatial, visual learning styles. NCSU's sequential learning style will be looked at separately. With the survey results, it can be determined if Physics students fall within the hypothesized learning styles.

Contact-free heart rate measurement using multiple video data

NASA Astrophysics Data System (ADS)

Hung, Pang-Chan; Lee, Kual-Zheng; Tsai, Luo-Wei

2013-10-01

In this paper, we propose a contact-free heart rate measurement method by analyzing sequential images of multiple video data. In the proposed method, skin-like pixels are firstly detected from multiple video data for extracting the color features. These color features are synchronized and analyzed by independent component analysis. A representative component is finally selected among these independent component candidates to measure the HR, which achieves under 2% deviation on average compared with a pulse oximeter in the controllable environment. The advantages of the proposed method include: 1) it uses low cost and high accessibility camera device; 2) it eases users' discomfort by utilizing contact-free measurement; and 3) it achieves the low error rate and the high stability by integrating multiple video data.

First-principles multiple-barrier diffusion theory. The case study of interstitial diffusion in CdTe

DOE PAGES

Yang, Ji -Hui; Park, Ji -Sang; Kang, Joongoo; ...

2015-02-17

The diffusion of particles in solid-state materials generally involves several sequential thermal-activation processes. However, presently, diffusion coefficient theory only deals with a single barrier, i.e., it lacks an accurate description to deal with multiple-barrier diffusion. Here, we develop a general diffusion coefficient theory for multiple-barrier diffusion. Using our diffusion theory and first-principles calculated hopping rates for each barrier, we calculate the diffusion coefficients of Cd, Cu, Te, and Cl interstitials in CdTe for their full multiple-barrier diffusion pathways. As a result, we found that the calculated diffusivity agrees well with the experimental measurement, thus justifying our theory, which is generalmore » for many other systems.« less

Impaired clinical utility of sequential patient GEM blood gas measurements associated with calibration schedule.

PubMed

Cembrowski, George S; Xu, Qian; Cembrowski, Adam R; Mei, Junyi; Sadrzadeh, Hossein

2017-11-01

Within- and/or between-instrument variation may falsely indicate patient trends or obscure real trends. We employ a methodology that transforms sequential intra-patient results into estimates of biologic and analytic variation. We previously derived realistic biologic variation (s b ) of blood gas (BG) and hematology analytes. We extend this methodology to derive the imprecision of two GEM 4000 BG analyzers. A laboratory data repository provided arterial BG, electrolyte and metabolite results generated by two GEM 4000s on ICU patients in 2012-2013. We tabulated consecutive pairs of intra-patient results separated by increasing time interval between consecutive tests. The average between pair variations were regressed against time with the y-intercept representing the sum of the biologic variation and short term analytic variation: y o 2 =s b 2 +s a 2 . Using an equivalent equation for the Radiometer ABL, the imprecision of the two GEMs was calculated: s aGEM =(y oGEM 2 -y oABL 2 +s aABL 2 ) 1/2 . This analysis was performed for nearly all measurements, regardless of time as well for values obtained over two 12h mutually exclusive periods, starting either at 2am or 2pm. Regression graphs were derived from 1800 patients' blood gas results with least 10,000 data pairs grouped into 2h intervals. The calculated s aGEM exceed the directly measured s aABL with many GEM sigma ratios of biologic variation/analytic variation being close to unity. All of the afternoon s aGEM exceeded their morning counterparts with pH, pCO 2 , K and bicarbonate being statistically significant. For many analytes, the average analytical variation of tandem GEMs approximates the biologic variation, indicating impaired clinical usefulness of tandem sequential measurements. A significant component of this variation is due to increased variation of the GEMs between 2pm and 2am. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

PubMed

Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D

2017-11-01

Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r 2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r 2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

SPReM: Sparse Projection Regression Model For High-dimensional Linear Regression *

PubMed Central

Sun, Qiang; Zhu, Hongtu; Liu, Yufeng; Ibrahim, Joseph G.

2014-01-01

The aim of this paper is to develop a sparse projection regression modeling (SPReM) framework to perform multivariate regression modeling with a large number of responses and a multivariate covariate of interest. We propose two novel heritability ratios to simultaneously perform dimension reduction, response selection, estimation, and testing, while explicitly accounting for correlations among multivariate responses. Our SPReM is devised to specifically address the low statistical power issue of many standard statistical approaches, such as the Hotelling’s T2 test statistic or a mass univariate analysis, for high-dimensional data. We formulate the estimation problem of SPREM as a novel sparse unit rank projection (SURP) problem and propose a fast optimization algorithm for SURP. Furthermore, we extend SURP to the sparse multi-rank projection (SMURP) by adopting a sequential SURP approximation. Theoretically, we have systematically investigated the convergence properties of SURP and the convergence rate of SURP estimates. Our simulation results and real data analysis have shown that SPReM out-performs other state-of-the-art methods. PMID:26527844

The effect of N-acetylcysteine on the incidence of contrast-induced kidney injury: A systematic review and trial sequential analysis.

PubMed

Wang, Nelson; Qian, Pierre; Kumar, Shejil; Yan, Tristan D; Phan, Kevin

2016-04-15

There have been a myriad of studies investigating the effectiveness of N-acetylcysteine (NAC) in the prevention of contrast induced nephropathy (CIN) in patients undergoing coronary angiography (CAG) with or without percutaneous coronary intervention (PCI). However the consensus is still out about the effectiveness of NAC pre-treatment due to vastly mixed results amongst the literature. The aim of this study was to conduct a meta-analysis and trial sequential analysis to determine the effects of pre-operative NAC in lowering the incidence of CIN in patients undergoing CAG and/or PCI. A systematic literature search was performed to include all randomized controlled trials (RCTs) comparing NAC versus control as pretreatment for CAG and/or PCI. A traditional meta-analysis and several subgroup analyses were conducted using traditional meta-analysis with relative risk (RR), trial sequential analysis, and meta-regression analysis. 43 RCTs met our inclusion criteria giving a total of 3277 patients in both control and treatment arms. There was a significant reduction in the risk of CIN in the NAC treated group compared to control (OR 0.666; 95% CI, 0.532-0.834; I2=40.11%; p=0.004). Trial sequential analysis, using a relative risk reduction threshold of 15%, indicates that the evidence is firm. The results of the present paper support the use of NAC in the prevention of CIN in patients undergoing CAG±PCI. Future studies should focus on the benefits of NAC amongst subgroups of high-risk patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sleep to the beat: A nap favours consolidation of timing.

PubMed

Verweij, Ilse M; Onuki, Yoshiyuki; Van Someren, Eus J W; Van der Werf, Ysbrand D

2016-06-01

Growing evidence suggests that sleep is important for procedural learning, but few studies have investigated the effect of sleep on the temporal aspects of motor skill learning. We assessed the effect of a 90-min day-time nap on learning a motor timing task, using 2 adaptations of a serial interception sequence learning (SISL) task. Forty-two right-handed participants performed the task before and after a 90-min period of sleep or wake. Electroencephalography (EEG) was recorded throughout. The motor task consisted of a sequential spatial pattern and was performed according to 2 different timing conditions, that is, either following a sequential or a random temporal pattern. The increase in accuracy was compared between groups using a mixed linear regression model. Within the sleep group, performance improvement was modeled based on sleep characteristics, including spindle- and slow-wave density. The sleep group, but not the wake group, showed improvement in the random temporal, but especially and significantly more strongly in the sequential temporal condition. None of the sleep characteristics predicted improvement on either general of the timing conditions. In conclusion, a daytime nap improves performance on a timing task. We show that performance on the task with a sequential timing sequence benefits more from sleep than motor timing. More important, the temporal sequence did not benefit initial learning, because differences arose only after an offline period and specifically when this period contained sleep. Sleep appears to aid in the extraction of regularities for optimal subsequent performance. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Anomalous weak values and the violation of a multiple-measurement Leggett-Garg inequality

NASA Astrophysics Data System (ADS)

Avella, Alessio; Piacentini, Fabrizio; Borsarelli, Michelangelo; Barbieri, Marco; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Degiovanni, Ivo Pietro; Genovese, Marco

2017-11-01

Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies, the so-called quantum technologies. The nonclassicality pointed out by Leggett-Garg inequalities has represented, with Bell inequalities, one of the most investigated subjects. In this article we study the connection of Leggett-Garg inequalities with a new emerging field of quantum measurement, the weak values in the case of a series of sequential measurements on a single object. In detail, we perform an experimental study of the four-time-correlator Leggett-Garg test, by exploiting single and sequential weak measurements performed on heralded single photons.

Sequential deconvolution from wave-front sensing using bivariate simplex splines

NASA Astrophysics Data System (ADS)

Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Xu, Rong; Liu, Changhai

2015-05-01

Deconvolution from wave-front sensing (DWFS) is an imaging compensation technique for turbulence degraded images based on simultaneous recording of short exposure images and wave-front sensor data. This paper employs the multivariate splines method for the sequential DWFS: a bivariate simplex splines based average slopes measurement model is built firstly for Shack-Hartmann wave-front sensor; next, a well-conditioned least squares estimator for the spline coefficients is constructed using multiple Shack-Hartmann measurements; then, the distorted wave-front is uniquely determined by the estimated spline coefficients; the object image is finally obtained by non-blind deconvolution processing. Simulated experiments in different turbulence strength show that our method performs superior image restoration results and noise rejection capability especially when extracting the multidirectional phase derivatives.

Simultaneous and Sequential Integration by Cre/loxP Site-Specific Recombination in Saccharomyces cerevisiae.

PubMed

Choi, Ho-Jung; Kim, Yeon-Hee

2018-05-28

A Cre/ loxP -δ-integration system was developed to allow sequential and simultaneous integration of a multiple gene expression cassette in Saccharomyces cerevisiae . To allow repeated integrations, the reusable Candida glabrata MARKER ( CgMARKER ) carrying loxP sequences was used, and the integrated CgMARKER was efficiently removed by inducing Cre recombinase. The XYLP and XYLB genes encoding endoxylanase and β-xylosidase, respectively, were used as model genes for xylan metabolism in this system, and the copy number of these genes was increased to 15.8 and 16.9 copies/cell, respectively, by repeated integration. This integration system is a promising approach for the easy construction of yeast strains with enhanced metabolic pathways through multicopy gene expression.

SOME STATISTICAL ISSUES RELATED TO MULTIPLE LINEAR REGRESSION MODELING OF BEACH BACTERIA CONCENTRATIONS

EPA Science Inventory

As a fast and effective technique, the multiple linear regression (MLR) method has been widely used in modeling and prediction of beach bacteria concentrations. Among previous works on this subject, however, several issues were insufficiently or inconsistently addressed. Those is...

MULTIPLE REGRESSION MODELS FOR HINDCASTING AND FORECASTING MIDSUMMER HYPOXIA IN THE GULF OF MEXICO

EPA Science Inventory

A new suite of multiple regression models were developed that describe the relationship between the area of bottom water hypoxia along the northern Gulf of Mexico and Mississippi-Atchafalaya River nitrate concentration, total phosphorus (TP) concentration, and discharge. Variabil...

Estimate the contribution of incubation parameters influence egg hatchability using multiple linear regression analysis

PubMed Central

Khalil, Mohamed H.; Shebl, Mostafa K.; Kosba, Mohamed A.; El-Sabrout, Karim; Zaki, Nesma

2016-01-01

Aim: This research was conducted to determine the most affecting parameters on hatchability of indigenous and improved local chickens’ eggs. Materials and Methods: Five parameters were studied (fertility, early and late embryonic mortalities, shape index, egg weight, and egg weight loss) on four strains, namely Fayoumi, Alexandria, Matrouh, and Montazah. Multiple linear regression was performed on the studied parameters to determine the most influencing one on hatchability. Results: The results showed significant differences in commercial and scientific hatchability among strains. Alexandria strain has the highest significant commercial hatchability (80.70%). Regarding the studied strains, highly significant differences in hatching chick weight among strains were observed. Using multiple linear regression analysis, fertility made the greatest percent contribution (71.31%) to hatchability, and the lowest percent contributions were made by shape index and egg weight loss. Conclusion: A prediction of hatchability using multiple regression analysis could be a good tool to improve hatchability percentage in chickens. PMID:27651666

Electromagnetic-induction logging to monitor changing chloride concentrations

USGS Publications Warehouse

Metzger, Loren F.; Izbicki, John A.

2013-01-01

Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality—possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

Efficient sequential and parallel algorithms for record linkage

PubMed Central

Mamun, Abdullah-Al; Mi, Tian; Aseltine, Robert; Rajasekaran, Sanguthevar

2014-01-01

Background and objective Integrating data from multiple sources is a crucial and challenging problem. Even though there exist numerous algorithms for record linkage or deduplication, they suffer from either large time needs or restrictions on the number of datasets that they can integrate. In this paper we report efficient sequential and parallel algorithms for record linkage which handle any number of datasets and outperform previous algorithms. Methods Our algorithms employ hierarchical clustering algorithms as the basis. A key idea that we use is radix sorting on certain attributes to eliminate identical records before any further processing. Another novel idea is to form a graph that links similar records and find the connected components. Results Our sequential and parallel algorithms have been tested on a real dataset of 1 083 878 records and synthetic datasets ranging in size from 50 000 to 9 000 000 records. Our sequential algorithm runs at least two times faster, for any dataset, than the previous best-known algorithm, the two-phase algorithm using faster computation of the edit distance (TPA (FCED)). The speedups obtained by our parallel algorithm are almost linear. For example, we get a speedup of 7.5 with 8 cores (residing in a single node), 14.1 with 16 cores (residing in two nodes), and 26.4 with 32 cores (residing in four nodes). Conclusions We have compared the performance of our sequential algorithm with TPA (FCED) and found that our algorithm outperforms the previous one. The accuracy is the same as that of this previous best-known algorithm. PMID:24154837

Sequential processing of GNSS-R delay-Doppler maps (DDM's) for ocean wind retrieval

NASA Astrophysics Data System (ADS)

Garrison, J. L.; Rodriguez-Alvarez, N.; Hoffman, R.; Annane, B.; Leidner, M.; Kaitie, S.

2016-12-01

The delay-Doppler map (DDM) is the fundamental data product from GNSS-Reflectometry (GNSS-R), generated by cross-correlating the scattered signal with a local signal model over a range of delays and Doppler frequencies. Delay and Doppler form a set of coordinates on the ocean surface and the shape of the DDM is related to the distribution of ocean slopes. Wind speed can thus be estimated by fitting a scattering model to the shape of the observed DDM or defining an observable (e.g. average power or leading edge slope) which characterizes the change in DDM shape. For spaceborne measurements, the DDM is composed of signals scattered from a glistening zone, which can extend for up to 100 km or more. Setting a reasonable resolution requirement (25 km or less) will limit the usable portion of the DDM at each observation to only a small region near the specular point. Cyclone-GNSS (CYGNSS) is a NASA mission to study developing tropical cyclones using GNSS-R. CYGNSS science requirements call for wind retrieval with an accuracy of 10 percent above 20 m/s within a 25 km resolution. This requirement can be met using an observable defined for DDM samples between +/- 0.25 chips in delay and +/- 1 kHz in Doppler, with some filtering of the observations using a minimum threshold for range corrected gain (RCG). An improved approach, to be reviewed in this presentation, sequentially processes multiple DDM's, to combine observations generated from different "looks" at the same points on the surface. Applying this sequential process to synthetic data indicates a significant improvement in wind retrieval accuracy over a 10 km grid covering a region around the specular point. The attached figure illustrates this improvement, using simulated CYGNSS DDM's generated using the wind fields from hurricanes Earl and Danielle (left). The middle plots show wind retrievals using only an observable defined within the 25 km resolution cell. The plots on the right side show the retrievals from sequential processing of multiple DDM's. Recently, the assimilation of GNSS-R retrievals into weather forecast models has been studied. The authors have begun to investigate the direct assimilation of other data products, such as the DDM itself, or the results of sequential processing.

Mean centering, multicollinearity, and moderators in multiple regression: The reconciliation redux.

PubMed

Iacobucci, Dawn; Schneider, Matthew J; Popovich, Deidre L; Bakamitsos, Georgios A

2017-02-01

In this article, we attempt to clarify our statements regarding the effects of mean centering. In a multiple regression with predictors A, B, and A × B (where A × B serves as an interaction term), mean centering A and B prior to computing the product term can clarify the regression coefficients (which is good) and the overall model fit R 2 will remain undisturbed (which is also good).

A Common Mechanism for Resistance to Oxime Reactivation of Acetylcholinesterase Inhibited by Organophosphorus Compounds

DTIC Science & Technology

2013-01-01

application of the Hammett equation with the constants rph in the chemistry of organophosphorus compounds, Russ. Chem. Rev. 38 (1969) 795–811. [13...of oximes and OP compounds and the ability of oximes to reactivate OP- inhibited AChE. Multiple linear regression equations were analyzed using...phosphonate pairs, 21 oxime/ phosphoramidate pairs and 12 oxime/phosphate pairs. The best linear regression equation resulting from multiple regression anal

Noise reduction methods for nucleic acid and macromolecule sequencing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuller, Ivan K.; Di Ventra, Massimiliano; Balatsky, Alexander

Methods, systems, and devices are disclosed for processing macromolecule sequencing data with substantial noise reduction. In one aspect, a method for reducing noise in a sequential measurement of a macromolecule comprising serial subunits includes cross-correlating multiple measured signals of a physical property of subunits of interest of the macromolecule, the multiple measured signals including the time data associated with the measurement of the signal, to remove or at least reduce signal noise that is not in the same frequency and in phase with the systematic signal contribution of the measured signals.

Novel applications of multitask learning and multiple output regression to multiple genetic trait prediction.

PubMed

He, Dan; Kuhn, David; Parida, Laxmi

2016-06-15

Given a set of biallelic molecular markers, such as SNPs, with genotype values encoded numerically on a collection of plant, animal or human samples, the goal of genetic trait prediction is to predict the quantitative trait values by simultaneously modeling all marker effects. Genetic trait prediction is usually represented as linear regression models. In many cases, for the same set of samples and markers, multiple traits are observed. Some of these traits might be correlated with each other. Therefore, modeling all the multiple traits together may improve the prediction accuracy. In this work, we view the multitrait prediction problem from a machine learning angle: as either a multitask learning problem or a multiple output regression problem, depending on whether different traits share the same genotype matrix or not. We then adapted multitask learning algorithms and multiple output regression algorithms to solve the multitrait prediction problem. We proposed a few strategies to improve the least square error of the prediction from these algorithms. Our experiments show that modeling multiple traits together could improve the prediction accuracy for correlated traits. The programs we used are either public or directly from the referred authors, such as MALSAR (http://www.public.asu.edu/~jye02/Software/MALSAR/) package. The Avocado data set has not been published yet and is available upon request. dhe@us.ibm.com. © The Author 2016. Published by Oxford University Press.

Simple and multiple linear regression: sample size considerations.

PubMed

Hanley, James A

2016-11-01

The suggested "two subjects per variable" (2SPV) rule of thumb in the Austin and Steyerberg article is a chance to bring out some long-established and quite intuitive sample size considerations for both simple and multiple linear regression. This article distinguishes two of the major uses of regression models that imply very different sample size considerations, neither served well by the 2SPV rule. The first is etiological research, which contrasts mean Y levels at differing "exposure" (X) values and thus tends to focus on a single regression coefficient, possibly adjusted for confounders. The second research genre guides clinical practice. It addresses Y levels for individuals with different covariate patterns or "profiles." It focuses on the profile-specific (mean) Y levels themselves, estimating them via linear compounds of regression coefficients and covariates. By drawing on long-established closed-form variance formulae that lie beneath the standard errors in multiple regression, and by rearranging them for heuristic purposes, one arrives at quite intuitive sample size considerations for both research genres. Copyright © 2016 Elsevier Inc. All rights reserved.

Multiple imputation for cure rate quantile regression with censored data.

PubMed

Wu, Yuanshan; Yin, Guosheng

2017-03-01

The main challenge in the context of cure rate analysis is that one never knows whether censored subjects are cured or uncured, or whether they are susceptible or insusceptible to the event of interest. Considering the susceptible indicator as missing data, we propose a multiple imputation approach to cure rate quantile regression for censored data with a survival fraction. We develop an iterative algorithm to estimate the conditionally uncured probability for each subject. By utilizing this estimated probability and Bernoulli sample imputation, we can classify each subject as cured or uncured, and then employ the locally weighted method to estimate the quantile regression coefficients with only the uncured subjects. Repeating the imputation procedure multiple times and taking an average over the resultant estimators, we obtain consistent estimators for the quantile regression coefficients. Our approach relaxes the usual global linearity assumption, so that we can apply quantile regression to any particular quantile of interest. We establish asymptotic properties for the proposed estimators, including both consistency and asymptotic normality. We conduct simulation studies to assess the finite-sample performance of the proposed multiple imputation method and apply it to a lung cancer study as an illustration. © 2016, The International Biometric Society.

Association Between Internalized HIV-Related Stigma and HIV Care Visit Adherence.

PubMed

Rice, Whitney S; Crockett, Kaylee B; Mugavero, Michael J; Raper, James L; Atkins, Ghislaine C; Turan, Bulent

2017-12-15

Internalized HIV-related stigma acts as a barrier to antiretroviral therapy (ART) adherence, but its effects on other HIV care continuum outcomes are unclear. Among 196 HIV clinic patients in Birmingham, AL, we assessed internalized HIV-related stigma and depressive symptom severity using validated multi-item scales and assessed ART adherence using a validated single-item measure. HIV visit adherence (attended out of total scheduled visits) was calculated using data from clinic records. Using covariate-adjusted regression analysis, we investigated the association between internalized stigma and visit adherence. Using path analytic methods with bootstrapping, we tested the mediating role of depressive symptoms in the association between internalized stigma and visit adherence and the mediating role of visit adherence in the association between internalized stigma and ART adherence. Higher internalized stigma was associated with lower visit adherence (B = -0.04, P = 0.04). Black (versus white) race and depressive symptoms were other significant predictors within this model. Mediation analysis yielded no indirect effect through depression in the association between internalized stigma and visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02) in the whole sample. Supplemental mediated moderation analyses revealed gender-specific effects. Additionally, the effect of internalized stigma on suboptimal ART adherence was mediated by lower visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02). Results highlight the importance of internalized HIV stigma to multiple and sequential HIV care continuum outcomes. Also, findings suggest multiple intervention targets, including addressing internalized stigma directly, reducing depressive symptoms, and promoting consistent engagement in care.

Drug effects on multiple and concurrent schedules of ethanol- and food-maintained behaviour: context-dependent selectivity

PubMed Central

Ginsburg, B C; Lamb, R J

2014-01-01

BACKGROUND AND PURPOSE Drugs that more potently or effectively reduce ethanol-maintained behaviour versus an alternative are considered selective and are considered promising pharmacotherapies for alcoholism. Such results are often obtained using separate groups or multiple schedules where ethanol and the alternative are available alone or sequentially. Recently, we observed that when ethanol and food were available sequentially under a multiple schedule, fluvoxamine and varenicline were selective; yet this selectivity disappeared when ethanol and food were concurrently available. EXPERIMENTAL APPROACH We examined the generality of these findings by comparing doses of several drugs required to decrease ethanol- and food-maintained responding under a multiple schedule and under a concurrent schedule. Effects were determined for chlordiazepoxide, 2,5-dimethoxy-4-iodoamphetamine (DOI), meta-chlorophenylpiperazine (mCPP), morphine, naltrexone and d-amphetamine. KEY RESULTS Under the multiple schedule, ED50 values for decreases in ethanol-maintained responding were significantly different and lower than ED50s for decreases in food-maintained responding (demonstrating selectivity) for each drug except for chlordiazepoxide (which was equipotent) and naltrexone (which did not affect responding). However, this selectivity vanished or even inverted under the concurrent schedule, such that ED50 values for decreasing ethanol- and food-maintained responding were not different (or, following DOI, the ED50 for food-maintained responding was lower than for ethanol-maintained responding). CONCLUSIONS AND IMPLICATIONS Results are consistent with those seen following fluvoxamine and varenicline administration, and suggest that selectivity is assay-dependent. These results indicate the need for careful interpretation of selective drug effects, especially when obtained in situations where ethanol or the alternative is the only programmed reinforcement available. PMID:24697498

Drug effects on multiple and concurrent schedules of ethanol- and food-maintained behaviour: context-dependent selectivity.

PubMed

Ginsburg, B C; Lamb, R J

2014-07-01

Drugs that more potently or effectively reduce ethanol-maintained behaviour versus an alternative are considered selective and are considered promising pharmacotherapies for alcoholism. Such results are often obtained using separate groups or multiple schedules where ethanol and the alternative are available alone or sequentially. Recently, we observed that when ethanol and food were available sequentially under a multiple schedule, fluvoxamine and varenicline were selective; yet this selectivity disappeared when ethanol and food were concurrently available. We examined the generality of these findings by comparing doses of several drugs required to decrease ethanol- and food-maintained responding under a multiple schedule and under a concurrent schedule. Effects were determined for chlordiazepoxide, 2,5-dimethoxy-4-iodoamphetamine (DOI), meta-chlorophenylpiperazine (mCPP), morphine, naltrexone and d-amphetamine. Under the multiple schedule, ED50 values for decreases in ethanol-maintained responding were significantly different and lower than ED50 s for decreases in food-maintained responding (demonstrating selectivity) for each drug except for chlordiazepoxide (which was equipotent) and naltrexone (which did not affect responding). However, this selectivity vanished or even inverted under the concurrent schedule, such that ED50 values for decreasing ethanol- and food-maintained responding were not different (or, following DOI, the ED50 for food-maintained responding was lower than for ethanol-maintained responding). Results are consistent with those seen following fluvoxamine and varenicline administration, and suggest that selectivity is assay-dependent. These results indicate the need for careful interpretation of selective drug effects, especially when obtained in situations where ethanol or the alternative is the only programmed reinforcement available. © 2014 The British Pharmacological Society.

The effects of multiple infections on the expression and evolution of virulence in a Daphnia-endoparasite system.

PubMed

Ben-Ami, Frida; Mouton, Laurence; Ebert, Dieter

2008-07-01

Multiple infections of a host by different strains of the same microparasite are common in nature. Although numerous models have been developed in an attempt to predict the evolutionary effects of intrahost competition, tests of the assumptions of these models are rare and the outcome is diverse. In the present study we examined the outcome of mixed-isolate infections in individual hosts, using a single clone of the waterflea Daphnia magna and three isolates of its semelparous endoparasite Pasteuria ramosa. We exposed individual Daphnia to single- and mixed-isolate infection treatments, both simultaneously and sequentially. Virulence was assessed by monitoring host mortality and fecundity, and parasite spore production was used as a measure of parasite fitness. Consistent with most assumptions, in multiply infected hosts we found that the virulence of mixed infections resembled that of the more virulent competitor, both in simultaneous multiple infections and in sequential multiple infections in which the virulent isolate was first to infect. The more virulent competitor also produced the vast majority of transmission stages. Only when the less virulent isolate was first to infect, the intrahost contest resembled scramble competition, whereby both isolates suffered by producing fewer transmission stages. Surprisingly, mixed-isolate infections resulted in lower fecundity-costs for the hosts, suggesting that parasite competition comes with an advantage for the host relative to single infections. Finally, spore production correlated positively with time-to-host-death. Thus, early-killing of more competitive isolates produces less transmission stages than less virulent, inferior isolates. Our results are consistent with the idea that less virulent parasite lines may be replaced by more virulent strains under conditions with high rates of multiple infections.

Undergraduate Student Motivation in Modularized Developmental Mathematics Courses

ERIC Educational Resources Information Center

Pachlhofer, Keith A.

2017-01-01

This study used the Motivated Strategies for Learning Questionnaire in modularized courses at three institutions across the nation (N = 189), and multiple regression was completed to investigate five categories of student motivation that predicted academic success and course completion. The overall multiple regression analysis was significant and…

MULGRES: a computer program for stepwise multiple regression analysis

Treesearch

A. Jeff Martin

1971-01-01

MULGRES is a computer program source deck that is designed for multiple regression analysis employing the technique of stepwise deletion in the search for most significant variables. The features of the program, along with inputs and outputs, are briefly described, with a note on machine compatibility.

Categorical Variables in Multiple Regression: Some Cautions.

ERIC Educational Resources Information Center

O'Grady, Kevin E.; Medoff, Deborah R.

1988-01-01

Limitations of dummy coding and nonsense coding as methods of coding categorical variables for use as predictors in multiple regression analysis are discussed. The combination of these approaches often yields estimates and tests of significance that are not intended by researchers for inclusion in their models. (SLD)

Comparison of the sequential organ failure assessment score with the King's College Hospital criteria and the model for end-stage liver disease score for the prognosis of acetaminophen-induced acute liver failure.

PubMed

Cholongitas, Evangelos; Theocharidou, Eleni; Vasianopoulou, Panayota; Betrosian, Alex; Shaw, Steve; Patch, David; O'Beirne, James; Agarwal, Banwari; Burroughs, Andrew K

2012-04-01

Acetaminophen-induced acute liver failure (ALF) is a complex multiorgan illness. An assessment of the prognosis is essential for the accurate identification of patients for whom survival without liver transplantation (LT) is unlikely. The aims of this study were the comparison of prognostic models [King's College Hospital (KCH), Model for End-Stage Liver Disease, Sequential Organ Failure Assessment (SOFA), and Acute Physiology and Chronic Health Evaluation II (APACHE II)] and the identification of independent prognostic indicators of outcome. We evaluated consecutive patients with severe acetaminophen-induced ALF who were admitted to the intensive care unit. At admission, demographic, clinical, and laboratory parameters were recorded. The discriminative ability of each prognostic score at the baseline was evaluated with the area under the receiver operating characteristic curve (AUC). In addition, using a multiple logistic regression, we assessed independent factors associated with outcome. In all, 125 consecutive patients with acetaminophen-induced ALF were evaluated: 67 patients (54%) survived with conservative medical management (group 1), and 58 patients (46%) either died without LT (28%) or underwent LT (18%; group 2). Group 1 patients had significantly lower median APACHE II (10 versus 14) and SOFA scores (9 versus 12) than group 2 patients (P < 0.001). The independent indicators associated with death or LT were a longer prothrombin time (P = 0.007), the inspiratory oxygen concentration (P = 0.005), and the lactate level at 12 hours (P < 0.001). The KCH criteria had the highest specificity (83%) but the lowest sensitivity (47%), and the SOFA score had the best discriminative ability (AUC = 0.79). In conclusion, for patients with acetaminophen-induced ALF, the SOFA score performed better than the other prognostic scores, and this reflected the presence of multiorgan dysfunction. A further evaluation of SOFA with the KCH criteria is warranted. Copyright © 2012 American Association for the Study of Liver Diseases.

The respective effects of soil heavy metal fractions by sequential extraction procedure and soil properties on the accumulation of heavy metals in rice grains and brassicas.

PubMed

Xiao, Ling; Guan, Dongsheng; Peart, M R; Chen, Yujuan; Li, Qiqi

2017-01-01

This study was carried out to examine heavy metal accumulation in rice grains and brassicas and to identify the different controls, such as soil properties and soil heavy metal fractions obtained by the Community Bureau of Reference (BCR) sequential extraction, in their accumulation. In Guangdong Province, South China, rice grain and brassica samples, along with their rhizospheric soil, were collected from fields on the basis of distance downstream from electroplating factories, whose wastewater was used for irrigation. The results showed that long-term irrigation using the electroplating effluent has not only enriched the rhizospheric soil with Cd, Cr, Cu, and Zn but has also increased their mobility and bioavailability. The average concentrations of Cd and Cr in rice grains and brassicas from closest to the electroplating factories were significantly higher than those from the control areas. Results from hybrid redundancy analysis (hRDA) and redundancy analysis (RDA) showed that the BCR fractions of soil heavy metals could explain 29.0 and 46.5 % of total eigenvalue for heavy metal concentrations in rice grains and brassicas, respectively, while soil properties could only explain 11.1 and 33.4 %, respectively. This indicated that heavy metal fractions exerted more control upon their concentrations in rice grains and brassicas than soil properties. In terms of metal interaction, an increase of residual Zn in paddy soil or a decrease of acid soluble Cd in the brassica soil could enhance the accumulation of Cd, Cu, Cr, and Pb in both rice grains and brassicas, respectively, while the reducible or oxidizable Cd in soil could enhance the plants' accumulation of Cr and Pb. The RDA showed an inhibition effect of sand content and CFO on the accumulation of heavy metals in rice grains and brassicas. Moreover, multiple stepwise linear regression could offer prediction for Cd, Cu, Cr, and Zn concentrations in the two crops by soil heavy metal fractions and soil properties.

Stimulus-to-matching-stimulus interval influences N1, P2, and P3b in an equiprobable Go/NoGo task.

PubMed

Steiner, Genevieve Z; Barry, Robert J; Gonsalvez, Craig J

2014-10-01

Previous research has shown that as the stimulus-to-matching-stimulus interval (including the target-to-target interval, TTI, and nontarget-to-nontarget interval, NNI) increases, the amplitude of the P300 ERP component increases systematically. Here, we extended previous P300 research and explored TTI and NNI effects on the various ERP components elicited in an auditory equiprobable Go/NoGo task. We also examined whether a similar mechanism was underpinning interval effects in early ERP components (e.g., N1). Thirty participants completed a specially-designed variable-ISI equiprobable task whilst their EEG activity was recorded. Component amplitudes were extracted using temporal PCA with unrestricted Varimax rotation. As expected, N1, P2, and P3b amplitudes increased as TTI and NNI increased, however, Processing Negativity (PN) and Slow Wave (SW) did not show the same systematic change with interval increments. To determine the origin of interval effects in sequential processing, a multiple regression analysis was conducted on each ERP component including stimulus type, interval, and all preceding components as predictors. These analyses showed that matching-stimulus interval predicted N1, P3b, and weakly predicted P2, but not PN or SW; SW was determined by P3b only. These results suggest that N1, P3b, and to some extent, P2, are affected by a similar temporal mechanism. However, the dissimilar pattern of results obtained for sequential ERP components indicates that matching-stimulus intervals are not affecting all aspects of stimulus processing. This argues against a global mechanism, such as a pathway-specific refractory effect, and suggests that stimulus processing is occurring in parallel pathways, some of which are not affected by temporal manipulations of matching-stimulus interval. Copyright © 2014 Elsevier B.V. All rights reserved.

Risk Factors for Multiple Organ Dysfunction Syndrome in Severe Stroke Patients

PubMed Central

Yang, Shuna; Li, Yue; Yuan, Junliang; Yang, Lei; Li, Shujuan; Hu, Wenli

2016-01-01

Background Severe stroke patients have poor clinical outcome which may be associated with development of multiple organ dysfunction syndrome (MODS). Therefore, the aim of our study was to investigate independent risk factors for development of MODS in severe stroke patients. Methods Ninety seven severe stroke patients were prospective recruited from Jan 2011 to Jun 2015. The development of MODS was identified by Sequential Organ Failure Assessment (SOFA) score (score ≥ 3, at least two organs), which was assessed on day 1, 4, 7, 10 and 14 after admission. Baseline characteristics, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Glasgow coma score (GCS) and cerebral imaging parameters were collected at admission. Cox regression was performed to determine predictors for the development of MODS. Medical complications after admission and in-hospital mortality were also investigated. Results 33 (34%) patients were in MODS group and 64 (66%) were in non-MODS group within 14 days after admission. Patients in MODS group had more smoker (51.5% vs 28.1%, p = 0.023), higher NIHSS score (23.48 ± 6.12 vs 19.81 ± 4.83, p = 0.004), higher APACHE II score (18.70 ± 5.18 vs 15.64 ± 4.36, p = 0.003) and lower GCS score (6.33 ± 2.48 vs 8.14 ± 2.73, p = 0.002). They also had higher rate of infarction in multi vascular territories (36.4% vs 10.9%, p = 0.003). The most common complication in all patients was pulmonary infection, while complication scores were comparable between two groups. Patients with MODS had higher in-hospital mortality (69.7% vs 9.4%, p = 0.000). In Cox regression, NIHSS score (RR = 1.084, 95% CI 1.019–1.153) and infarction in multi vascular territories (RR = 2.345 95% CI 1.105–4.978) were independent risk factors for development of MODS. Conclusions In acute phase of stroke, NIHSS score and infarction in multi vascular territories predicted MODS in severe stroke patients. Moreover, patients with MODS had higher in-hospital mortality, suggesting that early identification of MODS is critical important. PMID:27893797

Multiple Imputation of a Randomly Censored Covariate Improves Logistic Regression Analysis.

PubMed

Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

2016-01-01

Randomly censored covariates arise frequently in epidemiologic studies. The most commonly used methods, including complete case and single imputation or substitution, suffer from inefficiency and bias. They make strong parametric assumptions or they consider limit of detection censoring only. We employ multiple imputation, in conjunction with semi-parametric modeling of the censored covariate, to overcome these shortcomings and to facilitate robust estimation. We develop a multiple imputation approach for randomly censored covariates within the framework of a logistic regression model. We use the non-parametric estimate of the covariate distribution or the semiparametric Cox model estimate in the presence of additional covariates in the model. We evaluate this procedure in simulations, and compare its operating characteristics to those from the complete case analysis and a survival regression approach. We apply the procedures to an Alzheimer's study of the association between amyloid positivity and maternal age of onset of dementia. Multiple imputation achieves lower standard errors and higher power than the complete case approach under heavy and moderate censoring and is comparable under light censoring. The survival regression approach achieves the highest power among all procedures, but does not produce interpretable estimates of association. Multiple imputation offers a favorable alternative to complete case analysis and ad hoc substitution methods in the presence of randomly censored covariates within the framework of logistic regression.

Sequential resection of lung metastasis following partial hepatectomy for colorectal cancer.

PubMed

Ike, H; Shimada, H; Togo, S; Yamaguchi, S; Ichikawa, Y; Tanaka, K

2002-09-01

Multiple organ metastases from colorectal carcinoma may be considered incurable, but long survival after both liver and lung resection for metastases has been reported. A retrospective analysis of 48 patients who underwent lung resection for metastatic colorectal cancer between 1992 and 1999 was undertaken. Twenty-seven patients had lung metastasis alone, 15 had previous partial hepatectomy, and six had previous resection of local or lymph node recurrence. The relationship of clinical variables to survival was assessed. Survival was calculated from the time of first pulmonary resection. Five-year survival rates after resection of lung metastasis were 73 per cent in patients without preceding recurrence, 50 per cent following previous partial hepatectomy and zero after resection of previous local recurrence. Independent prognostic variables that significantly affected survival after thoracotomy were primary tumour histology and type of preceding recurrence. There was no significant difference in survival after lung resection between patients who had sequential liver and lung resection versus those who had lung resection alone. Sequential lung resection after partial hepatectomy for metastatic colorectal cancer may lead to long-term survival.

Diagnostic causal reasoning with verbal information.

PubMed

Meder, Björn; Mayrhofer, Ralf

2017-08-01

In diagnostic causal reasoning, the goal is to infer the probability of causes from one or multiple observed effects. Typically, studies investigating such tasks provide subjects with precise quantitative information regarding the strength of the relations between causes and effects or sample data from which the relevant quantities can be learned. By contrast, we sought to examine people's inferences when causal information is communicated through qualitative, rather vague verbal expressions (e.g., "X occasionally causes A"). We conducted three experiments using a sequential diagnostic inference task, where multiple pieces of evidence were obtained one after the other. Quantitative predictions of different probabilistic models were derived using the numerical equivalents of the verbal terms, taken from an unrelated study with different subjects. We present a novel Bayesian model that allows for incorporating the temporal weighting of information in sequential diagnostic reasoning, which can be used to model both primacy and recency effects. On the basis of 19,848 judgments from 292 subjects, we found a remarkably close correspondence between the diagnostic inferences made by subjects who received only verbal information and those of a matched control group to whom information was presented numerically. Whether information was conveyed through verbal terms or numerical estimates, diagnostic judgments closely resembled the posterior probabilities entailed by the causes' prior probabilities and the effects' likelihoods. We observed interindividual differences regarding the temporal weighting of evidence in sequential diagnostic reasoning. Our work provides pathways for investigating judgment and decision making with verbal information within a computational modeling framework. Copyright © 2017 Elsevier Inc. All rights reserved.

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

PubMed Central

Kuiken, Todd A; Hargrove, Levi J

2014-01-01

Objective Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main Results Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts' Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts' Law tasks with high levels of path efficiency. Significance These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control. PMID:25394366

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

NASA Astrophysics Data System (ADS)

Smith, Lauren H.; Kuiken, Todd A.; Hargrove, Levi J.

2014-12-01

Objective. Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach. We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main results. Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts’ Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts’ Law tasks with high levels of path efficiency. Significance. These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control.

Advanced Statistics for Exotic Animal Practitioners.

PubMed

Hodsoll, John; Hellier, Jennifer M; Ryan, Elizabeth G

2017-09-01

Correlation and regression assess the association between 2 or more variables. This article reviews the core knowledge needed to understand these analyses, moving from visual analysis in scatter plots through correlation, simple and multiple linear regression, and logistic regression. Correlation estimates the strength and direction of a relationship between 2 variables. Regression can be considered more general and quantifies the numerical relationships between an outcome and 1 or multiple variables in terms of a best-fit line, allowing predictions to be made. Each technique is discussed with examples and the statistical assumptions underlying their correct application. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of Thematic Mapper for water quality assessment

NASA Technical Reports Server (NTRS)

Horn, E. M.; Morrissey, L. A.

1984-01-01

The evaluation of simulated TM data obtained on an ER-2 aircraft at twenty-five predesignated sample sites for mapping water quality factors such as conductivity, pH, suspended solids, turbidity, temperature, and depth, is discussed. Using a multiple regression for the seven TM bands, an equation is developed for the suspended solids. TM bands 1, 2, 3, 4, and 6 are used with logarithm conductivity in a multiple regression. The assessment of regression equations for a high coefficient of determination (R-squared) and statistical significance is considered. Confidence intervals about the mean regression point are calculated in order to assess the robustness of the regressions used for mapping conductivity, turbidity, and suspended solids, and by regressing random subsamples of sites and comparing the resultant range of R-squared, cross validation is conducted.

Weed and Onion Response to multiple Applications of Goal Tender beginning at the 1-Leaf Stage of Onion

USDA-ARS?s Scientific Manuscript database

Broadleaf weed control in onion is difficult in part due to a lack of postemergence herbicide options at an early growth stage of onions. Onion tolerance to sequential applications of oxyfluorfen (Goal-Tender) alone and with bromoxynil (Buctril) beginning at the 1-lf stage of onions was evaluated n...

Evaluating Multiple Imputation Models for the Southern Annual Forest Inventory

Treesearch

Gregory A. Reams; Joseph M. McCollum

1999-01-01

The USDA Forest Service's Southern Research Station is implementing an annualized forest survey in thirteen states. The sample design is a systematic sample of five interpenetrating grids (panels), where each panel is measured sequentially. For example, panel one information is collected in year one, and panel five in year five. The area representative and time...

Coping and Psychological Adjustment among Mothers of Children with ASD: An Accelerated Longitudinal Study

ERIC Educational Resources Information Center

Benson, Paul R.

2014-01-01

Utilizing a cohort sequential design and multilevel modeling on a sample of 113 mothers, the effects of four coping strategies (engagement, disengagement, distraction, and cognitive reframing) on multiple measures of maternal adjustment were assessed over a 7 years period when children with autism spectrum disorders in the study were approximately…

MURI: Adaptive Waveform Design for Full Spectral Dominance

DTIC Science & Technology

2011-03-11

a three- dimensional urban tracking model, based on the nonlinear measurement model (that uses the urban multipath geometry with different types of ... the time evolution of the scattering function with a high dimensional dynamic system; a multiple particle filter technique is used to sequentially...integration of space -time coding with a fixed set of beams. It complements the

Fourth Graders' Cognitive Processes and Learning Strategies for Reading Illustrated Biology Texts: Eye Movement Measurements

ERIC Educational Resources Information Center

Jian, Yu-Cin

2016-01-01

Previous research suggests that multiple representations can improve science reading comprehension. This facilitation effect is premised on the observation that readers can efficiently integrate information in text and diagram formats; however, this effect in young readers is still contested. Using eye-tracking technology and sequential analysis,…

Attitudes toward Using Social Networking Sites in Educational Settings with Underperforming Latino Youth: A Mixed Methods Study

ERIC Educational Resources Information Center

Howard, Keith E.; Curwen, Margie Sauceda; Howard, Nicol R.; Colón-Muñiz, Anaida

2015-01-01

The researchers examined the online social networking attitudes of underperforming Latino high school students in an alternative education program that uses technology as the prime venue for learning. A sequential explanatory mixed methods study was used to cross-check multiple sources of data explaining students' levels of comfort with utilizing…

Extreme Quantile Estimation in Binary Response Models

DTIC Science & Technology

1990-03-01

in Cancer Research," Biometria , VoL 66, pp. 307-316. Hsi, B.P. [1969], ’The Multiple Sample Up-and-Down Method in Bioassay," Journal of the American...New Method of Estimation," Biometria , VoL 53, pp. 439-454. Wetherill, G.B. [1976], Sequential Methods in Statistics, London: Chapman and Hall. Wu, C.FJ

Multiple stage miniature stepping motor

DOEpatents

Niven, William A.; Shikany, S. David; Shira, Michael L.

1981-01-01

A stepping motor comprising a plurality of stages which may be selectively activated to effect stepping movement of the motor, and which are mounted along a common rotor shaft to achieve considerable reduction in motor size and minimum diameter, whereby sequential activation of the stages results in successive rotor steps with direction being determined by the particular activating sequence followed.

Bovine respiratory disease model based on dual infections with infection with bovine viral diarrhea virus and bovine corona virus

USDA-ARS?s Scientific Manuscript database

Bovine respiratory disease complex (BRDC) is the leading cause of economic loss in the U.S. cattle industry. BRDC likely results from simultaneous or sequential infections with multiple pathogens including both viruses and bacteria. Bovine viral diarrhea virus (BVDV) and bovine corona virus (BoCV...

Simulated impact of climate change on hydrology of multiple watersheds using traditional and recommended snowmelt runoff model methodology

USDA-ARS?s Scientific Manuscript database

For more than three decades, researchers have utilized the Snowmelt Runoff Model (SRM) to test the impacts of climate change on streamflow of snow-fed systems. In this study, the hydrological effects of climate change are modeled over three sequential years using SRM with both typical and recommende...

The [Gamma] Algorithm and Some Applications

ERIC Educational Resources Information Center

Castillo, Enrique; Jubete, Francisco

2004-01-01

In this paper the power of the [gamma] algorithm for obtaining the dual of a given cone and some of its multiple applications is discussed. The meaning of each sequential tableau appearing during the process is interpreted. It is shown that each tableau contains the generators of the dual cone of a given cone and that the algorithm updates the…

Parent-Infant Synchrony and the Construction of Shared Timing; Physiological Precursors, Developmental Outcomes, and Risk Conditions

ERIC Educational Resources Information Center

Feldman, Ruth

2007-01-01

Synchrony, a construct used across multiple fields to denote the temporal relationship between events, is applied to the study of parent-infant interactions and suggested as a model for intersubjectivity. Three types of timed relationships between the parent and child's affective behavior are assessed: concurrent, sequential, and organized in an…

Method and system for controlled combustion engines

DOEpatents

Oppenheim, A. K.

1990-01-01

A system for controlling combustion in internal combustion engines of both the Diesel or Otto type, which relies on establishing fluid dynamic conditions and structures wherein fuel and air are entrained, mixed and caused to be ignited in the interior of a multiplicity of eddies, and where these structures are caused to sequentially fill the headspace of the cylinders.

Parental Beliefs and Experiences Regarding Involvement in Intervention for Their Child with Speech Sound Disorder

ERIC Educational Resources Information Center

Watts Pappas, Nicole; McAllister, Lindy; McLeod, Sharynne

2016-01-01

Parental beliefs and experiences regarding involvement in speech intervention for their child with mild to moderate speech sound disorder (SSD) were explored using multiple, sequential interviews conducted during a course of treatment. Twenty-one interviews were conducted with seven parents of six children with SSD: (1) after their child's initial…

Sharing "Cat Games" and Cookies: Special Education Students Investigate Division

ERIC Educational Resources Information Center

Taber, Susan B.; Canonica, Michele

2008-01-01

Learning mathematics has traditionally been thought of as a sequential progression. Children learn to count to 10, then to 20, and then to 100. They learn to add without regrouping and then with regrouping. The authors teach addition before multiplication and the two-times table before the six-times table. They usually teach division as a separate…

75 FR 32773 - Auction of 218-219 MHz Service and Phase II 220 MHz Service Licenses Scheduled for December 7...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... licenses included in Auction 89 using the Commission's standard simultaneous multiple-round auction format... sequential bidding rounds. The initial bidding schedule will be announced in a public notice to be released.... For Auction 89, the Bureau proposes to employ a simultaneous stopping rule approach. A simultaneous...

ViSA: A Neurodynamic Model for Visuo-Spatial Working Memory, Attentional Blink, and Conscious Access

ERIC Educational Resources Information Center

Simione, Luca; Raffone, Antonino; Wolters, Gezinus; Salmas, Paola; Nakatani, Chie; Belardinelli, Marta Olivetti; van Leeuwen, Cees

2012-01-01

Two separate lines of study have clarified the role of selectivity in conscious access to visual information. Both involve presenting multiple targets and distracters: one "simultaneously" in a spatially distributed fashion, the other "sequentially" at a single location. To understand their findings in a unified framework, we propose a…

Sequential Rift Valley Fever Outbreaks in Kenya, Somalia, and Tanzania in 2006-2007 Associated with Multiple Lineages of the Virus

USDA-ARS?s Scientific Manuscript database

Routine testing for Campylobacter spp. in the food chain is primarily directed toward detection of C. jejuni and C. coli, thus the presence of novel Campylobacter spp., and their relative contribution to human illness, is not well understood. A survey to determine the presence of Campylobacter spp....

Benefits and Drawbacks of Using Multiple Instructors to Teach Single Courses

ERIC Educational Resources Information Center

Jones, Francis; Harris, Sara

2012-01-01

We set out to identify the benefits and drawbacks of using more than one instructor to teach single section science courses at a large research university. Nine courses were investigated involving widely differing subjects and levels. Teaching models included: sequential teaching with two to six instructors each covering only their own modules,…

INTRODUCTION TO A COMBINED MULTIPLE LINEAR REGRESSION AND ARMA MODELING APPROACH FOR BEACH BACTERIA PREDICTION

EPA Science Inventory

Due to the complexity of the processes contributing to beach bacteria concentrations, many researchers rely on statistical modeling, among which multiple linear regression (MLR) modeling is most widely used. Despite its ease of use and interpretation, there may be time dependence...

Determining the Spatial and Seasonal Variability in OM/OC Ratios across the U.S. Using Multiple Regression

EPA Science Inventory

Data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network are used to estimate organic mass to organic carbon (OM/OC) ratios across the United States by extending previously published multiple regression techniques. Our new methodology addresses com...

Analysis and Interpretation of Findings Using Multiple Regression Techniques

ERIC Educational Resources Information Center

Hoyt, William T.; Leierer, Stephen; Millington, Michael J.

2006-01-01

Multiple regression and correlation (MRC) methods form a flexible family of statistical techniques that can address a wide variety of different types of research questions of interest to rehabilitation professionals. In this article, we review basic concepts and terms, with an emphasis on interpretation of findings relevant to research questions…

Tracking the Gender Pay Gap: A Case Study

ERIC Educational Resources Information Center

Travis, Cheryl B.; Gross, Louis J.; Johnson, Bruce A.

2009-01-01

This article provides a short introduction to standard considerations in the formal study of wages and illustrates the use of multiple regression and resampling simulation approaches in a case study of faculty salaries at one university. Multiple regression is especially beneficial where it provides information on strength of association, specific…

Estimating air drying times of lumber with multiple regression

Treesearch

William T. Simpson

2004-01-01

In this study, the applicability of a multiple regression equation for estimating air drying times of red oak, sugar maple, and ponderosa pine lumber was evaluated. The equation allows prediction of estimated air drying times from historic weather records of temperature and relative humidity at any desired location.

Using Robust Variance Estimation to Combine Multiple Regression Estimates with Meta-Analysis

ERIC Educational Resources Information Center

Williams, Ryan

2013-01-01

The purpose of this study was to explore the use of robust variance estimation for combining commonly specified multiple regression models and for combining sample-dependent focal slope estimates from diversely specified models. The proposed estimator obviates traditionally required information about the covariance structure of the dependent…

Multiple Regression: A Leisurely Primer.

ERIC Educational Resources Information Center

Daniel, Larry G.; Onwuegbuzie, Anthony J.

Multiple regression is a useful statistical technique when the researcher is considering situations in which variables of interest are theorized to be multiply caused. It may also be useful in those situations in which the researchers is interested in studies of predictability of phenomena of interest. This paper provides an introduction to…

Using Monte Carlo Techniques to Demonstrate the Meaning and Implications of Multicollinearity

ERIC Educational Resources Information Center

Vaughan, Timothy S.; Berry, Kelly E.

2005-01-01

This article presents an in-class Monte Carlo demonstration, designed to demonstrate to students the implications of multicollinearity in a multiple regression study. In the demonstration, students already familiar with multiple regression concepts are presented with a scenario in which the "true" relationship between the response and…

Assessing the Impact of Influential Observations on Multiple Regression Analysis on Human Resource Research.

ERIC Educational Resources Information Center

Bates, Reid A.; Holton, Elwood F., III; Burnett, Michael F.

1999-01-01

A case study of learning transfer demonstrates the possible effect of influential observation on linear regression analysis. A diagnostic method that tests for violation of assumptions, multicollinearity, and individual and multiple influential observations helps determine which observation to delete to eliminate bias. (SK)

A field trial of ethyl hexanediol against Aedes dorsalis in Sonoma County, California.

PubMed

Rutledge, L C; Hooper, R L; Wirtz, R A; Gupta, R K

1989-09-01

The repellent ethyl hexanediol (2-ethyl-1,3-hexanediol) was tested against the mosquito Aedes dorsalis in a coastal salt marsh in California. The experimental design incorporated a linear regression model, sequential treatments and a proportional end point (95%) for protection time. The protection time of 0.10 mg/cm2 ethyl hexanediol was estimated at 0.8 h. This time is shorter than that obtained previously for deet (N,N-diethyl-3-methylbenzamide) against Ae. dorsalis (4.4 h).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, Troy Michael; Kress, Joel David; Bhat, Kabekode Ghanasham

Year 1 Objectives (August 2016 – December 2016) – The original Independence model is a sequentially regressed set of parameters from numerous data sets in the Aspen Plus modeling framework. The immediate goal with the basic data model is to collect and evaluate those data sets relevant to the thermodynamic submodels (pure substance heat capacity, solvent mixture heat capacity, loaded solvent heat capacities, and volatility data). These data are informative for the thermodynamic parameters involved in both vapor-liquid equilibrium, and in the chemical equilibrium of the liquid phase.

Ventromedial prefrontal and anterior cingulate cortex adopt choice and default reference frames during sequential multialternative choice

PubMed Central

Boorman, Erie D; Rushworth, Matthew F; Behrens, Tim E

2013-01-01

Although damage to medial frontal cortex causes profound decision-making impairments, it has been difficult to pinpoint the relative contributions of key anatomical subdivisions. Here we use fMRI to examine the contributions of human ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortex (dACC) during sequential choices between multiple alternatives – two key features of choices made in ecological settings. By carefully constructing options whose current value at any given decision was dissociable from their longer-term value, we were able to examine choices in current and long-term frames of reference. We present evidence showing that activity at choice and feedback in vmPFC and dACC was tied to the current choice and the best long-term option, respectively. vmPFC, mid-cingulate, and PCC encoded the relative value between the chosen and next-best option at each sequential decision, whereas dACC encoded the relative value of adapting choices from the option with the highest value in the longer-term. Furthermore, at feedback we identify temporally dissociable effects that predict repetition of the current choice and adaptation away from the long-term best option in vmPFC and dACC, respectively. These functional dissociations at choice and feedback suggest that sequential choices are subject to competing cortical mechanisms. PMID:23392656

Dry minor mergers and size evolution of high-z compact massive early-type galaxies

NASA Astrophysics Data System (ADS)

Oogi, Taira; Habe, Asao

2012-09-01

Recent observations show evidence that high-z (z ~ 2 - 3) early-type galaxies (ETGs) are quite compact than that with comparable mass at z ~ 0. Dry merger scenario is one of the most probable one that can explain such size evolution. However, previous studies based on this scenario do not succeed to explain both properties of high-z compact massive ETGs and local ETGs, consistently. We investigate effects of sequential, multiple dry minor (stellar mass ratio M2/M1<1/4) mergers on the size evolution of compact massive ETGs. We perform N-body simulations of the sequential minor mergers with parabolic and head-on orbits, including a dark matter component and a stellar component. We show that the sequential minor mergers of compact satellite galaxies are the most efficient in the size growth and in decrease of the velocity dispersion of the compact massive ETGs. The change of stellar size and density of the merger remnant is consistent with the recent observations. Furthermore, we construct the merger histories of candidates of high-z compact massive ETGs using the Millennium Simulation Database, and estimate the size growth of the galaxies by dry minor mergers. We can reproduce the mean size growth factor between z = 2 and z = 0, assuming the most efficient size growth obtained in the case of the sequential minor mergers in our simulations.

Variable-Domain Functional Regression for Modeling ICU Data.

PubMed

Gellar, Jonathan E; Colantuoni, Elizabeth; Needham, Dale M; Crainiceanu, Ciprian M

2014-12-01

We introduce a class of scalar-on-function regression models with subject-specific functional predictor domains. The fundamental idea is to consider a bivariate functional parameter that depends both on the functional argument and on the width of the functional predictor domain. Both parametric and nonparametric models are introduced to fit the functional coefficient. The nonparametric model is theoretically and practically invariant to functional support transformation, or support registration. Methods were motivated by and applied to a study of association between daily measures of the Intensive Care Unit (ICU) Sequential Organ Failure Assessment (SOFA) score and two outcomes: in-hospital mortality, and physical impairment at hospital discharge among survivors. Methods are generally applicable to a large number of new studies that record a continuous variables over unequal domains.

Price, Weather, and `Acreage Abandonment' in Western Great Plains Wheat Culture.

NASA Astrophysics Data System (ADS)

Michaels, Patrick J.

1983-07-01

Multivariate analyses of acreage abandonment patterns in the U.S. Great Plains winter wheat region indicate that the major mode of variation is an in-phase oscillation confined to the western half of the overall area, which is also the area with lowest average yields. This is one of the more agroclimatically marginal environments in the United States, with wide interannual fluctuations in both climate and profitability.We developed a multiple regression model to determine the relative roles of weather and expected price in the decision not to harvest. The overall model explained 77% of the spatial and temporal variation in abandonment. The 36.5% of the non-spatial variation was explained by two simple transformations of climatic data from three monthly aggregates-September-October, November-February and March-April. Price factors, expressed as indexed future delivery quotations,were barely significant, with only between 3 and 5% of the non-spatial variation explained, depending upon the model.The model was based upon weather, climate and price data from 1932 through 1975. It was tested by sequentially withholding three-year blocks of data, and using the respecified regression coefficients, along with observed weather and price, to estimate abandonment in the withheld years. Error analyses indicate no loss of model fidelity in the test mode. Also, prediction errors in the 1970-75 period, characterized by widely fluctuating prices, were not different from those in the rest of the model.The overall results suggest that the perceived quality of the crop, as influenced by weather, is a much more important determinant of the abandonment decision than are expected returns based upon price considerations.

Speciation distribution and mass balance of copper and zinc in urban rain, sediments, and road runoff.

PubMed

Zuo, Xiaojun; Fu, Dafang; Li, He

2012-11-01

Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.

Regularization Paths for Conditional Logistic Regression: The clogitL1 Package.

PubMed

Reid, Stephen; Tibshirani, Rob

2014-07-01

We apply the cyclic coordinate descent algorithm of Friedman, Hastie, and Tibshirani (2010) to the fitting of a conditional logistic regression model with lasso [Formula: see text] and elastic net penalties. The sequential strong rules of Tibshirani, Bien, Hastie, Friedman, Taylor, Simon, and Tibshirani (2012) are also used in the algorithm and it is shown that these offer a considerable speed up over the standard coordinate descent algorithm with warm starts. Once implemented, the algorithm is used in simulation studies to compare the variable selection and prediction performance of the conditional logistic regression model against that of its unconditional (standard) counterpart. We find that the conditional model performs admirably on datasets drawn from a suitable conditional distribution, outperforming its unconditional counterpart at variable selection. The conditional model is also fit to a small real world dataset, demonstrating how we obtain regularization paths for the parameters of the model and how we apply cross validation for this method where natural unconditional prediction rules are hard to come by.

Regularization Paths for Conditional Logistic Regression: The clogitL1 Package

PubMed Central

Reid, Stephen; Tibshirani, Rob

2014-01-01

We apply the cyclic coordinate descent algorithm of Friedman, Hastie, and Tibshirani (2010) to the fitting of a conditional logistic regression model with lasso (ℓ1) and elastic net penalties. The sequential strong rules of Tibshirani, Bien, Hastie, Friedman, Taylor, Simon, and Tibshirani (2012) are also used in the algorithm and it is shown that these offer a considerable speed up over the standard coordinate descent algorithm with warm starts. Once implemented, the algorithm is used in simulation studies to compare the variable selection and prediction performance of the conditional logistic regression model against that of its unconditional (standard) counterpart. We find that the conditional model performs admirably on datasets drawn from a suitable conditional distribution, outperforming its unconditional counterpart at variable selection. The conditional model is also fit to a small real world dataset, demonstrating how we obtain regularization paths for the parameters of the model and how we apply cross validation for this method where natural unconditional prediction rules are hard to come by. PMID:26257587

TG study of the Li0.4Fe2.4Zn0.2O4 ferrite synthesis

NASA Astrophysics Data System (ADS)

Lysenko, E. N.; Nikolaev, E. V.; Surzhikov, A. P.

2016-02-01

In this paper, the kinetic analysis of Li-Zn ferrite synthesis was studied using thermogravimetry (TG) method through the simultaneous application of non-linear regression to several measurements run at different heating rates (multivariate non-linear regression). Using TG-curves obtained for the four heating rates and Netzsch Thermokinetics software package, the kinetic models with minimal adjustable parameters were selected to quantitatively describe the reaction of Li-Zn ferrite synthesis. It was shown that the experimental TG-curves clearly suggest a two-step process for the ferrite synthesis and therefore a model-fitting kinetic analysis based on multivariate non-linear regressions was conducted. The complex reaction was described by a two-step reaction scheme consisting of sequential reaction steps. It is established that the best results were obtained using the Yander three-dimensional diffusion model at the first stage and Ginstling-Bronstein model at the second step. The kinetic parameters for lithium-zinc ferrite synthesis reaction were found and discussed.

Global Synchronization of Multiple Recurrent Neural Networks With Time Delays via Impulsive Interactions.

PubMed

Yang, Shaofu; Guo, Zhenyuan; Wang, Jun

2017-07-01

In this paper, new results on the global synchronization of multiple recurrent neural networks (NNs) with time delays via impulsive interactions are presented. Impulsive interaction means that a number of NNs communicate with each other at impulse instants only, while they are independent at the remaining time. The communication topology among NNs is not required to be always connected and can switch ON and OFF at different impulse instants. By using the concept of sequential connectivity and the properties of stochastic matrices, a set of sufficient conditions depending on time delays is derived to ascertain global synchronization of multiple continuous-time recurrent NNs. In addition, a counterpart on the global synchronization of multiple discrete-time NNs is also discussed. Finally, two examples are presented to illustrate the results.

Neutron multiplicity counting: Confidence intervals for reconstruction parameters

DOE PAGES

Verbeke, Jerome M.

2016-03-09

From nuclear materials accountability to homeland security, the need for improved nuclear material detection, assay, and authentication has grown over the past decades. Starting in the 1940s, neutron multiplicity counting techniques have enabled quantitative evaluation of masses and multiplications of fissile materials. In this paper, we propose a new method to compute uncertainties on these parameters using a model-based sequential Bayesian processor, resulting in credible regions in the fissile material mass and multiplication space. These uncertainties will enable us to evaluate quantitatively proposed improvements to the theoretical fission chain model. Additionally, because the processor can calculate uncertainties in real time,more » it is a useful tool in applications such as portal monitoring: monitoring can stop as soon as a preset confidence of non-threat is reached.« less

Memory and other properties of multiple test procedures generated by entangled graphs.

PubMed

Maurer, Willi; Bretz, Frank

2013-05-10

Methods for addressing multiplicity in clinical trials have attracted much attention during the past 20 years. They include the investigation of new classes of multiple test procedures, such as fixed sequence, fallback and gatekeeping procedures. More recently, sequentially rejective graphical test procedures have been introduced to construct and visualize complex multiple test strategies. These methods propagate the local significance level of a rejected null hypothesis to not-yet rejected hypotheses. In the graph defining the test procedure, hypotheses together with their local significance levels are represented by weighted vertices and the propagation rule by weighted directed edges. An algorithm provides the rules for updating the local significance levels and the transition weights after rejecting an individual hypothesis. These graphical procedures have no memory in the sense that the origin of the propagated significance level is ignored in subsequent iterations. However, in some clinical trial applications, memory is desirable to reflect the underlying dependence structure of the study objectives. In such cases, it would allow the further propagation of significance levels to be dependent on their origin and thus reflect the grouped parent-descendant structures of the hypotheses. We will give examples of such situations and show how to induce memory and other properties by convex combination of several individual graphs. The resulting entangled graphs provide an intuitive way to represent the underlying relative importance relationships between the hypotheses, are as easy to perform as the original individual graphs, remain sequentially rejective and control the familywise error rate in the strong sense. Copyright © 2012 John Wiley & Sons, Ltd.

Effects of multiple collections on spermatozoa quality of Persian sturgeon, Acipenser persicus: motility, density and seminal plasma composition.

PubMed

Aramli, M S; Kalbassi, M R; Gharibi, M R

2015-02-01

In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH-A2, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p < 0.05) after the second and third collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl(-) ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p < 0.05) of seminal plasma was observed. This study provides new data on the effects of multiple collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Mapping soil textural fractions across a large watershed in north-east Florida.

PubMed

Lamsal, S; Mishra, U

2010-08-01

Assessment of regional scale soil spatial variation and mapping their distribution is constrained by sparse data which are collected using field surveys that are labor intensive and cost prohibitive. We explored geostatistical (ordinary kriging-OK), regression (Regression Tree-RT), and hybrid methods (RT plus residual Sequential Gaussian Simulation-SGS) to map soil textural fractions across the Santa Fe River Watershed (3585 km(2)) in north-east Florida. Soil samples collected from four depths (L1: 0-30 cm, L2: 30-60 cm, L3: 60-120 cm, and L4: 120-180 cm) at 141 locations were analyzed for soil textural fractions (sand, silt and clay contents), and combined with textural data (15 profiles) assembled under the Florida Soil Characterization program. Textural fractions in L1 and L2 were autocorrelated, and spatially mapped across the watershed. OK performance was poor, which may be attributed to the sparse sampling. RT model structure varied among textural fractions, and the model explained variations ranged from 25% for L1 silt to 61% for L2 clay content. Regression residuals were simulated using SGS, and the average of simulated residuals were used to approximate regression residual distribution map, which were added to regression trend maps. Independent validation of the prediction maps showed that regression models performed slightly better than OK, and regression combined with average of simulated regression residuals improved predictions beyond the regression model. Sand content >90% in both 0-30 and 30-60 cm covered 80.6% of the watershed area. Copyright 2010 Elsevier Ltd. All rights reserved.

A novel simple QSAR model for the prediction of anti-HIV activity using multiple linear regression analysis.

PubMed

Afantitis, Antreas; Melagraki, Georgia; Sarimveis, Haralambos; Koutentis, Panayiotis A; Markopoulos, John; Igglessi-Markopoulou, Olga

2006-08-01

A quantitative-structure activity relationship was obtained by applying Multiple Linear Regression Analysis to a series of 80 1-[2-hydroxyethoxy-methyl]-6-(phenylthio) thymine (HEPT) derivatives with significant anti-HIV activity. For the selection of the best among 37 different descriptors, the Elimination Selection Stepwise Regression Method (ES-SWR) was utilized. The resulting QSAR model (R (2) (CV) = 0.8160; S (PRESS) = 0.5680) proved to be very accurate both in training and predictive stages.

Deriving percentage study weights in multi-parameter meta-analysis models: with application to meta-regression, network meta-analysis and one-stage individual participant data models.

PubMed

Riley, Richard D; Ensor, Joie; Jackson, Dan; Burke, Danielle L

2017-01-01

Many meta-analysis models contain multiple parameters, for example due to multiple outcomes, multiple treatments or multiple regression coefficients. In particular, meta-regression models may contain multiple study-level covariates, and one-stage individual participant data meta-analysis models may contain multiple patient-level covariates and interactions. Here, we propose how to derive percentage study weights for such situations, in order to reveal the (otherwise hidden) contribution of each study toward the parameter estimates of interest. We assume that studies are independent, and utilise a decomposition of Fisher's information matrix to decompose the total variance matrix of parameter estimates into study-specific contributions, from which percentage weights are derived. This approach generalises how percentage weights are calculated in a traditional, single parameter meta-analysis model. Application is made to one- and two-stage individual participant data meta-analyses, meta-regression and network (multivariate) meta-analysis of multiple treatments. These reveal percentage study weights toward clinically important estimates, such as summary treatment effects and treatment-covariate interactions, and are especially useful when some studies are potential outliers or at high risk of bias. We also derive percentage study weights toward methodologically interesting measures, such as the magnitude of ecological bias (difference between within-study and across-study associations) and the amount of inconsistency (difference between direct and indirect evidence in a network meta-analysis).

[Application of SAS macro to evaluated multiplicative and additive interaction in logistic and Cox regression in clinical practices].

PubMed

Nie, Z Q; Ou, Y Q; Zhuang, J; Qu, Y J; Mai, J Z; Chen, J M; Liu, X Q

2016-05-01

Conditional logistic regression analysis and unconditional logistic regression analysis are commonly used in case control study, but Cox proportional hazard model is often used in survival data analysis. Most literature only refer to main effect model, however, generalized linear model differs from general linear model, and the interaction was composed of multiplicative interaction and additive interaction. The former is only statistical significant, but the latter has biological significance. In this paper, macros was written by using SAS 9.4 and the contrast ratio, attributable proportion due to interaction and synergy index were calculated while calculating the items of logistic and Cox regression interactions, and the confidence intervals of Wald, delta and profile likelihood were used to evaluate additive interaction for the reference in big data analysis in clinical epidemiology and in analysis of genetic multiplicative and additive interactions.

Wavelet regression model in forecasting crude oil price

NASA Astrophysics Data System (ADS)

Hamid, Mohd Helmie; Shabri, Ani

2017-05-01

This study presents the performance of wavelet multiple linear regression (WMLR) technique in daily crude oil forecasting. WMLR model was developed by integrating the discrete wavelet transform (DWT) and multiple linear regression (MLR) model. The original time series was decomposed to sub-time series with different scales by wavelet theory. Correlation analysis was conducted to assist in the selection of optimal decomposed components as inputs for the WMLR model. The daily WTI crude oil price series has been used in this study to test the prediction capability of the proposed model. The forecasting performance of WMLR model were also compared with regular multiple linear regression (MLR), Autoregressive Moving Average (ARIMA) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) using root mean square errors (RMSE) and mean absolute errors (MAE). Based on the experimental results, it appears that the WMLR model performs better than the other forecasting technique tested in this study.

Multiple regression for physiological data analysis: the problem of multicollinearity.

PubMed

Slinker, B K; Glantz, S A

1985-07-01

Multiple linear regression, in which several predictor variables are related to a response variable, is a powerful statistical tool for gaining quantitative insight into complex in vivo physiological systems. For these insights to be correct, all predictor variables must be uncorrelated. However, in many physiological experiments the predictor variables cannot be precisely controlled and thus change in parallel (i.e., they are highly correlated). There is a redundancy of information about the response, a situation called multicollinearity, that leads to numerical problems in estimating the parameters in regression equations; the parameters are often of incorrect magnitude or sign or have large standard errors. Although multicollinearity can be avoided with good experimental design, not all interesting physiological questions can be studied without encountering multicollinearity. In these cases various ad hoc procedures have been proposed to mitigate multicollinearity. Although many of these procedures are controversial, they can be helpful in applying multiple linear regression to some physiological problems.

Testing Mediation Using Multiple Regression and Structural Equation Modeling Analyses in Secondary Data

ERIC Educational Resources Information Center

Li, Spencer D.

2011-01-01

Mediation analysis in child and adolescent development research is possible using large secondary data sets. This article provides an overview of two statistical methods commonly used to test mediated effects in secondary analysis: multiple regression and structural equation modeling (SEM). Two empirical studies are presented to illustrate the…

A Simple and Convenient Method of Multiple Linear Regression to Calculate Iodine Molecular Constants

ERIC Educational Resources Information Center

Cooper, Paul D.

2010-01-01

A new procedure using a student-friendly least-squares multiple linear-regression technique utilizing a function within Microsoft Excel is described that enables students to calculate molecular constants from the vibronic spectrum of iodine. This method is advantageous pedagogically as it calculates molecular constants for ground and excited…

Conjoint Analysis: A Study of the Effects of Using Person Variables.

ERIC Educational Resources Information Center

Fraas, John W.; Newman, Isadore

Three statistical techniques--conjoint analysis, a multiple linear regression model, and a multiple linear regression model with a surrogate person variable--were used to estimate the relative importance of five university attributes for students in the process of selecting a college. The five attributes include: availability and variety of…

An Exploratory Study of Face-to-Face and Cyberbullying in Sixth Grade Students

ERIC Educational Resources Information Center

Accordino, Denise B.; Accordino, Michael P.

2011-01-01

In a pilot study, sixth grade students (N = 124) completed a questionnaire assessing students' experience with bullying and cyberbullying, demographic information, quality of parent-child relationship, and ways they have dealt with bullying/cyberbullying in the past. Two multiple regression analyses were conducted. The multiple regression analysis…

The Use of Multiple Regression and Trend Analysis to Understand Enrollment Fluctuations. AIR Forum 1979 Paper.

ERIC Educational Resources Information Center

Campbell, S. Duke; Greenberg, Barry

The development of a predictive equation capable of explaining a significant percentage of enrollment variability at Florida International University is described. A model utilizing trend analysis and a multiple regression approach to enrollment forecasting was adapted to investigate enrollment dynamics at the university. Four independent…

The Use of Multiple Regression Models to Determine if Conjoint Analysis Should Be Conducted on Aggregate Data.

ERIC Educational Resources Information Center

Fraas, John W.; Newman, Isadore

1996-01-01

In a conjoint-analysis consumer-preference study, researchers must determine whether the product factor estimates, which measure consumer preferences, should be calculated and interpreted for each respondent or collectively. Multiple regression models can determine whether to aggregate data by examining factor-respondent interaction effects. This…

Double Cross-Validation in Multiple Regression: A Method of Estimating the Stability of Results.

ERIC Educational Resources Information Center

Rowell, R. Kevin

In multiple regression analysis, where resulting predictive equation effectiveness is subject to shrinkage, it is especially important to evaluate result replicability. Double cross-validation is an empirical method by which an estimate of invariance or stability can be obtained from research data. A procedure for double cross-validation is…

Epidemiologic Approaches to Evaluating the Potential for Human Papillomavirus Type Replacement Postvaccination

PubMed Central

Tota, Joseph E.; Ramanakumar, Agnihotram V.; Jiang, Mengzhu; Dillner, Joakim; Walter, Stephen D.; Kaufman, Jay S.; Coutlée, François; Villa, Luisa L.; Franco, Eduardo L.

2013-01-01

Currently, 2 vaccines exist that prevent infection by the genotypes of human papillomavirus (HPV) responsible for approximately 70% of cervical cancer cases worldwide. Although vaccination is expected to reduce the prevalence of these HPV types, there is concern about the effect this could have on the distribution of other oncogenic types. According to basic ecological principles, if competition exists between ≥2 different HPV types for niche occupation during natural infection, elimination of 1 type may lead to an increase in other type(s). Here, we discuss this issue of “type replacement” and present different epidemiologic approaches for evaluation of HPV type competition. Briefly, these approaches involve: 1) calculation of the expected frequency of coinfection under independence between HPV types for comparison with observed frequency; 2) construction of hierarchical logistic regression models for each vaccine-targeted type; and 3) construction of Kaplan-Meier curves and Cox models to evaluate sequential acquisition and clearance of HPV types according to baseline HPV status. We also discuss a related issue concerning diagnostic artifacts arising when multiple HPV types are present in specific samples (due to the inability of broad-spectrum assays to detect certain types present in lower concentrations). This may result in an apparent increase in previously undetected types postvaccination. PMID:23660798

Dissociation mediates the association between intimate partner violence and posttraumatic stress among treatment-seeking incarcerated women.

PubMed

DeCou, Christopher R; Lynch, Shannon M; Cole, Trevor T; Kaplan, Stephanie P

2016-01-01

Women in prison experience high rates of interpersonal trauma as well as elevated rates of posttraumatic stress disorder (PTSD) relative to women in the general population. The present study examined the relationship between recent intimate partner violence (IPV), additional forms of lifetime trauma exposure, trait dissociation, and posttraumatic stress among a sample of incarcerated female survivors of IPV. Participants were 186 treatment-seeking incarcerated women who reported experiences of IPV in the year prior to incarceration. Participants completed self-report measures of IPV, nonpartner-perpetrated lifetime trauma exposure, trait dissociation, and PTSD symptomatology. Associations among study variables were evaluated using sequential multiple regression. Participants reported experiencing several forms of interpersonal trauma. More than half of respondents (i.e., 53%) fell beyond a conservative cutoff score on the PTSD Checklist-Civilian Version, indicating clinically significant symptoms of PTSD. Trait dissociation partially mediated the association between IPV and PTSD symptoms above and beyond history of nonpartner-perpetrated violence. Trait dissociation emerged as the strongest independent predictor of PTSD symptoms and explained approximately 15% of the variance in PTSD symptoms. This finding highlights the need for additional research concerning dissociation among women in prison and warrants consideration in future research and intervention efforts focused on trauma recovery among incarcerated women.

The Perceptions of STEM from Eighth-Grade African-American Girls in a High-Minority Middle School

NASA Astrophysics Data System (ADS)

Hare, LaChanda N.

Even with the existence of STEM curriculum and STEM programs that target women and minorities, African-American females still lag behind other ethnic groups in STEM fields. Reasons for the underrepresentation of females in STEM fields can be traced back to the early years of schooling. The purpose of this study was to identify the factors that impact African-American females' perspectives of STEM subjects and STEM careers. An explanatory sequential mixed-methods approach was used for data collection with a survey, focus group, and interview. Forty male (N=12) and female (N=28) students from different ethnic groups were surveyed. The focus group and interview sessions consisted of 21 African-American females from two distinct groups: those enrolled in the school's STEM program (STEM) and those who were not enrolled in the STEM program (Non-STEM). The self-efficacy theory and social cognitive career theory served as the theoretical constructs guiding the data analysis. Multiple regression results showed that outcome expectation and personal disposition had the greatest influence on the females' interest in STEM content and STEM careers. Results from the qualitative portion of the study revealed that the learning environment and STEM self-efficacy had a significant impact on African-American females' interest in STEM.

Childhood trauma, depression, and sleep quality and their association with psychotic symptoms and suicidality in schizophrenia.

PubMed

Kilicaslan, Esin Evren; Esen, Asli Tugba; Kasal, Meltem Izci; Ozelci, Erdal; Boysan, Murat; Gulec, Mustafa

2017-12-01

This study involved the examination of the relationship between childhood trauma and both psychotic symptoms and suicidality in patients with schizophrenia after controlling for the possible confounding factors, such as clinical features, depression, and sleep quality. The Childhood Trauma Questionnaire-Short Form, Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS), Pittsburgh Sleep Quality Index (PSQI), and the suicidality subscale of Mini-International Neuropsychiatric Interview (MINI) were administered to 199 patients with schizophrenia. We used sequential multiple stepwise regression analyses in which positive symptoms, negative symptoms, overall psychopathology, total symptoms of schizophrenia, and suicidality were dependent variables. Depressive symptomatology and childhood physical abuse significantly contributed to positive, negative, general psychopathology, and global schizophrenia symptomatology. Interestingly, general psychopathology scores were negatively associated with childhood physical neglect. Also, subjective sleep quality significantly contributed to positive schizophrenia symptoms. Although prior suicide attempts and depression were significant antecedents of suicidal ideation, no association between suicidality and both childhood trauma and sleep was found. Childhood physical abuse could have an impact on psychopathology in schizophrenia. In addition to childhood trauma, depression, sleep disturbances, and clinical features should be considered and inquired about in the course of clinical care of schizophrenia patients. Copyright © 2017 Elsevier B.V. All rights reserved.

A simple method for HPLC retention time prediction: linear calibration using two reference substances.

PubMed

Sun, Lei; Jin, Hong-Yu; Tian, Run-Tao; Wang, Ming-Juan; Liu, Li-Na; Ye, Liu-Ping; Zuo, Tian-Tian; Ma, Shuang-Cheng

2017-01-01

Analysis of related substances in pharmaceutical chemicals and multi-components in traditional Chinese medicines needs bulk of reference substances to identify the chromatographic peaks accurately. But the reference substances are costly. Thus, the relative retention (RR) method has been widely adopted in pharmacopoeias and literatures for characterizing HPLC behaviors of those reference substances unavailable. The problem is it is difficult to reproduce the RR on different columns due to the error between measured retention time (t R ) and predicted t R in some cases. Therefore, it is useful to develop an alternative and simple method for prediction of t R accurately. In the present study, based on the thermodynamic theory of HPLC, a method named linear calibration using two reference substances (LCTRS) was proposed. The method includes three steps, procedure of two points prediction, procedure of validation by multiple points regression and sequential matching. The t R of compounds on a HPLC column can be calculated by standard retention time and linear relationship. The method was validated in two medicines on 30 columns. It was demonstrated that, LCTRS method is simple, but more accurate and more robust on different HPLC columns than RR method. Hence quality standards using LCTRS method are easy to reproduce in different laboratories with lower cost of reference substances.

Improved coverage of cDNA-AFLP by sequential digestion of immobilized cDNA.

PubMed

Weiberg, Arne; Pöhler, Dirk; Morgenstern, Burkhard; Karlovsky, Petr

2008-10-13

cDNA-AFLP is a transcriptomics technique which does not require prior sequence information and can therefore be used as a gene discovery tool. The method is based on selective amplification of cDNA fragments generated by restriction endonucleases, electrophoretic separation of the products and comparison of the band patterns between treated samples and controls. Unequal distribution of restriction sites used to generate cDNA fragments negatively affects the performance of cDNA-AFLP. Some transcripts are represented by more than one fragment while other escape detection, causing redundancy and reducing the coverage of the analysis, respectively. With the goal of improving the coverage of cDNA-AFLP without increasing its redundancy, we designed a modified cDNA-AFLP protocol. Immobilized cDNA is sequentially digested with several restriction endonucleases and the released DNA fragments are collected in mutually exclusive pools. To investigate the performance of the protocol, software tool MECS (Multiple Enzyme cDNA-AFLP Simulation) was written in Perl. cDNA-AFLP protocols described in the literature and the new sequential digestion protocol were simulated on sets of cDNA sequences from mouse, human and Arabidopsis thaliana. The redundancy and coverage, the total number of PCR reactions, and the average fragment length were calculated for each protocol and cDNA set. Simulation revealed that sequential digestion of immobilized cDNA followed by the partitioning of released fragments into mutually exclusive pools outperformed other cDNA-AFLP protocols in terms of coverage, redundancy, fragment length, and the total number of PCRs. Primers generating 30 to 70 amplicons per PCR provided the highest fraction of electrophoretically distinguishable fragments suitable for normalization. For A. thaliana, human and mice transcriptome, the use of two marking enzymes and three sequentially applied releasing enzymes for each of the marking enzymes is recommended.

Development of Potent Antiviral Drugs Inspired by Viral Hexameric DNA-Packaging Motors with Revolving Mechanism

PubMed Central

Pi, Fengmei; Zhao, Zhengyi; Chelikani, Venkata; Yoder, Kristine; Kvaratskhelia, Mamuka

2016-01-01

The intracellular parasitic nature of viruses and the emergence of antiviral drug resistance necessitate the development of new potent antiviral drugs. Recently, a method for developing potent inhibitory drugs by targeting biological machines with high stoichiometry and a sequential-action mechanism was described. Inspired by this finding, we reviewed the development of antiviral drugs targeting viral DNA-packaging motors. Inhibiting multisubunit targets with sequential actions resembles breaking one bulb in a series of Christmas lights, which turns off the entire string. Indeed, studies on viral DNA packaging might lead to the development of new antiviral drugs. Recent elucidation of the mechanism of the viral double-stranded DNA (dsDNA)-packaging motor with sequential one-way revolving motion will promote the development of potent antiviral drugs with high specificity and efficiency. Traditionally, biomotors have been classified into two categories: linear and rotation motors. Recently discovered was a third type of biomotor, including the viral DNA-packaging motor, beside the bacterial DNA translocases, that uses a revolving mechanism without rotation. By analogy, rotation resembles the Earth's rotation on its own axis, while revolving resembles the Earth's revolving around the Sun (see animations at http://rnanano.osu.edu/movie.html). Herein, we review the structures of viral dsDNA-packaging motors, the stoichiometries of motor components, and the motion mechanisms of the motors. All viral dsDNA-packaging motors, including those of dsDNA/dsRNA bacteriophages, adenoviruses, poxviruses, herpesviruses, mimiviruses, megaviruses, pandoraviruses, and pithoviruses, contain a high-stoichiometry machine composed of multiple components that work cooperatively and sequentially. Thus, it is an ideal target for potent drug development based on the power function of the stoichiometries of target complexes that work sequentially. PMID:27356896

A strategy for comprehensive identification of sequential constituents using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer, application study on chlorogenic acids in Flos Lonicerae Japonicae.

PubMed

Zhang, Jia-yu; Wang, Zi-jian; Li, Yun; Liu, Ying; Cai, Wei; Li, Chen; Lu, Jian-qiu; Qiao, Yan-jiang

2016-01-15

The analytical methodologies for evaluation of multi-component system in traditional Chinese medicines (TCMs) have been inadequate or unacceptable. As a result, the unclarity of multi-component hinders the sufficient interpretation of their bioactivities. In this paper, an ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap (UPLC-LTQ-Orbitrap)-based strategy focused on the comprehensive identification of TCM sequential constituents was developed. The strategy was characterized by molecular design, multiple ion monitoring (MIM), targeted database hits and mass spectral trees similarity filter (MTSF), and even more isomerism discrimination. It was successfully applied in the HRMS data-acquisition and processing of chlorogenic acids (CGAs) in Flos Lonicerae Japonicae (FLJ), and a total of 115 chromatographic peaks attributed to 18 categories were characterized, allowing a comprehensive revelation of CGAs in FLJ for the first time. This demonstrated that MIM based on molecular design could improve the efficiency to trigger MS/MS fragmentation reactions. Targeted database hits and MTSF searching greatly facilitated the processing of extremely large information data. Besides, the introduction of diagnostic product ions (DPIs) discrimination, ClogP analysis, and molecular simulation, raised the efficiency and accuracy to characterize sequential constituents especially position and geometric isomers. In conclusion, the results expanded our understanding on CGAs in FLJ, and the strategy could be exemplary for future research on the comprehensive identification of sequential constituents in TCMs. Meanwhile, it may propose a novel idea for analyzing sequential constituents, and is promising for quality control and evaluation of TCMs. Copyright © 2015 Elsevier B.V. All rights reserved.

Sequential Use of Anaplastic Lymphoma Kinase Inhibitors in Japanese Patients With ALK-Rearranged Non-Small-Cell Lung Cancer: A Retrospective Analysis.

PubMed

Asao, Tetsuhiko; Fujiwara, Yutaka; Itahashi, Kota; Kitahara, Shinsuke; Goto, Yasushi; Horinouchi, Hidehito; Kanda, Shintaro; Nokihara, Hiroshi; Yamamoto, Noboru; Takahashi, Kazuhisa; Ohe, Yuichiro

2017-07-01

Second-generation anaplastic lymphoma kinase (ALK) inhibitors, such as alectinib and ceritinib, have recently been approved for treatment of ALK-rearranged non-small-cell lung cancer (NSCLC). An optimal strategy for using 2 or more ALK inhibitors has not been established. We sought to investigate the clinical impact of sequential use of ALK inhibitors on these tumors in clinical practice. Patients with ALK-rearranged NSCLC treated from May 2010 to January 2016 at the National Cancer Center Hospital were identified, and their outcomes were evaluated retrospectively. Fifty-nine patients with ALK-rearranged NSCLC had been treated and 37 cases were assessable. Twenty-six received crizotinib, 21 received alectinib, and 13 (35.1%) received crizotinib followed by alectinib. Response rates and median progression-free survival (PFS) on crizotinib and alectinib (after crizotinib failure) were 53.8% (95% confidence interval [CI], 26.7%-80.9%) and 38.4% (95% CI, 12.0%-64.9%), and 10.7 (95% CI, 5.3-14.7) months and 16.6 (95% CI, 2.9-not calculable), respectively. The median PFS of patients on sequential therapy was 35.2 months (95% CI, 12.7 months-not calculable). The 5-year survival rate of ALK-rearranged patients who received 2 sequential ALK inhibitors from diagnosis was 77.8% (95% CI, 36.5%-94.0%). The combined PFS and 5-year survival rates in patients who received sequential ALK inhibitors were encouraging. Making full use of multiple ALK inhibitors might be important to prolonging survival in patients with ALK-rearranged NSCLC. Copyright © 2016 Elsevier Inc. All rights reserved.

Sequential experimental design based generalised ANOVA

NASA Astrophysics Data System (ADS)

Chakraborty, Souvik; Chowdhury, Rajib

2016-07-01

Over the last decade, surrogate modelling technique has gained wide popularity in the field of uncertainty quantification, optimization, model exploration and sensitivity analysis. This approach relies on experimental design to generate training points and regression/interpolation for generating the surrogate. In this work, it is argued that conventional experimental design may render a surrogate model inefficient. In order to address this issue, this paper presents a novel distribution adaptive sequential experimental design (DA-SED). The proposed DA-SED has been coupled with a variant of generalised analysis of variance (G-ANOVA), developed by representing the component function using the generalised polynomial chaos expansion. Moreover, generalised analytical expressions for calculating the first two statistical moments of the response, which are utilized in predicting the probability of failure, have also been developed. The proposed approach has been utilized in predicting probability of failure of three structural mechanics problems. It is observed that the proposed approach yields accurate and computationally efficient estimate of the failure probability.

Sequential experimental design based generalised ANOVA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, Souvik, E-mail: csouvik41@gmail.com; Chowdhury, Rajib, E-mail: rajibfce@iitr.ac.in

Over the last decade, surrogate modelling technique has gained wide popularity in the field of uncertainty quantification, optimization, model exploration and sensitivity analysis. This approach relies on experimental design to generate training points and regression/interpolation for generating the surrogate. In this work, it is argued that conventional experimental design may render a surrogate model inefficient. In order to address this issue, this paper presents a novel distribution adaptive sequential experimental design (DA-SED). The proposed DA-SED has been coupled with a variant of generalised analysis of variance (G-ANOVA), developed by representing the component function using the generalised polynomial chaos expansion. Moreover,more » generalised analytical expressions for calculating the first two statistical moments of the response, which are utilized in predicting the probability of failure, have also been developed. The proposed approach has been utilized in predicting probability of failure of three structural mechanics problems. It is observed that the proposed approach yields accurate and computationally efficient estimate of the failure probability.« less

Continued progress in the prevention of nail gun injuries among apprentice carpenters: what will it take to see wider spread injury reductions?

PubMed

Lipscomb, Hester J; Nolan, James; Patterson, Dennis; Dement, John M

2010-06-01

Nail guns are a common source of acute, and potentially serious, injury in residential construction. Data on nail gun injuries, hours worked and hours of tool use were collected in 2008 from union apprentice carpenters (n=464) through classroom surveys; this completed four years of serial cross-sectional data collection from apprentices. A predictive model of injury risk was constructed using Poisson regression. Injury rates declined 55% from baseline measures in 2005 with early training and increased use of tools with sequential actuation. Injury rates declined among users of tools with both actuation systems, but the rates of injury were consistently twice as high among those using tools with contact trip triggers. DISCUSSION AND IMPACT: Nail gun injuries can be reduced markedly through early training and use of tools with sequential actuation. These successful efforts need to be diffused broadly, including to the non-union sector. (c) 2010 Elsevier Ltd. All rights reserved.

Comparing the behavioural impact of a nudge-based handwashing intervention to high-intensity hygiene education: a cluster-randomised trial in rural Bangladesh.

PubMed

Grover, Elise; Hossain, Mohammed Kamal; Uddin, Saker; Venkatesh, Mohini; Ram, Pavani K; Dreibelbis, Robert

2018-01-01

To determine the impact of environmental nudges on handwashing behaviours among primary school children as compared to a high-intensity hygiene education intervention. In a cluster-randomised trial (CRT), we compared the rates of handwashing with soap (HWWS) after a toileting event among primary school students in rural Bangladesh. Eligible schools (government run, on-site sanitation and water, no hygiene interventions in last year, fewer than 450 students) were identified, and 20 schools were randomly selected and allocated without blinding to one of four interventions, five schools per group: simultaneous handwashing infrastructure and nudge construction, sequential infrastructure then nudge construction, simultaneous infrastructure and high-intensity hygiene education (HE) and sequential handwashing infrastructure and HE. The primary outcome, incidence of HWWS after a toileting event, was compared between the intervention groups at different data collection points with robust-Poisson regression analysis with generalised estimating equations, adjusting for school-level clustering of outcomes. The nudge intervention and the HE intervention were found to be equally effective at sustained impact over 5 months post-intervention (adjusted IRR 0.81, 95% CI 0.61-1.09). When comparing intervention delivery timing, the simultaneous delivery of the HE intervention significantly outperformed the sequential HE delivery (adjusted IRR 1.58 CI 1.20-2.08), whereas no significant difference was observed between sequential and simultaneous nudge intervention delivery (adjusted IRR 0.75, 95% CI 0.48-1.17). Our trial demonstrates sustained improved handwashing behaviour 5 months after the nudge intervention. The nudge intervention's comparable performance to a high-intensity hygiene education intervention is encouraging. © 2017 John Wiley & Sons Ltd.

Critical role of bevacizumab scheduling in combination with pre-surgical chemo-radiotherapy in MRI-defined high-risk locally advanced rectal cancer: Results of the BRANCH trial.

PubMed

Avallone, Antonio; Pecori, Biagio; Bianco, Franco; Aloj, Luigi; Tatangelo, Fabiana; Romano, Carmela; Granata, Vincenza; Marone, Pietro; Leone, Alessandra; Botti, Gerardo; Petrillo, Antonella; Caracò, Corradina; Iaffaioli, Vincenzo R; Muto, Paolo; Romano, Giovanni; Comella, Pasquale; Budillon, Alfredo; Delrio, Paolo

2015-10-06

We have previously shown that an intensified preoperative regimen including oxaliplatin plus raltitrexed and 5-fluorouracil/folinic acid (OXATOM/FUFA) during preoperative pelvic radiotherapy produced promising results in locally advanced rectal cancer (LARC). Preclinical evidence suggests that the scheduling of bevacizumab may be crucial to optimize its combination with chemo-radiotherapy. This non-randomized, non-comparative, phase II study was conducted in MRI-defined high-risk LARC. Patients received three biweekly cycles of OXATOM/FUFA during RT. Bevacizumab was given 2 weeks before the start of chemo-radiotherapy, and on the same day of chemotherapy for 3 cycles (concomitant-schedule A) or 4 days prior to the first and second cycle of chemotherapy (sequential-schedule B). Primary end point was pathological complete tumor regression (TRG1) rate. The accrual for the concomitant-schedule was early terminated because the number of TRG1 (2 out of 16 patients) was statistically inconsistent with the hypothesis of activity (30%) to be tested. Conversely, the endpoint was reached with the sequential-schedule and the final TRG1 rate among 46 enrolled patients was 50% (95% CI 35%-65%). Neutropenia was the most common grade ≥ 3 toxicity with both schedules, but it was less pronounced with the sequential than concomitant-schedule (30% vs. 44%). Postoperative complications occurred in 8/15 (53%) and 13/46 (28%) patients in schedule A and B, respectively. At 5 year follow-up the probability of PFS and OS was 80% (95%CI, 66%-89%) and 85% (95%CI, 69%-93%), respectively, for the sequential-schedule. These results highlights the relevance of bevacizumab scheduling to optimize its combination with preoperative chemo-radiotherapy in the management of LARC.

REML/BLUP and sequential path analysis in estimating genotypic values and interrelationships among simple maize grain yield-related traits.

PubMed

Olivoto, T; Nardino, M; Carvalho, I R; Follmann, D N; Ferrari, M; Szareski, V J; de Pelegrin, A J; de Souza, V Q

2017-03-22

Methodologies using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) in combination with sequential path analysis in maize are still limited in the literature. Therefore, the aims of this study were: i) to use REML/BLUP-based procedures in order to estimate variance components, genetic parameters, and genotypic values of simple maize hybrids, and ii) to fit stepwise regressions considering genotypic values to form a path diagram with multi-order predictors and minimum multicollinearity that explains the relationships of cause and effect among grain yield-related traits. Fifteen commercial simple maize hybrids were evaluated in multi-environment trials in a randomized complete block design with four replications. The environmental variance (78.80%) and genotype-vs-environment variance (20.83%) accounted for more than 99% of the phenotypic variance of grain yield, which difficult the direct selection of breeders for this trait. The sequential path analysis model allowed the selection of traits with high explanatory power and minimum multicollinearity, resulting in models with elevated fit (R 2 > 0.9 and ε < 0.3). The number of kernels per ear (NKE) and thousand-kernel weight (TKW) are the traits with the largest direct effects on grain yield (r = 0.66 and 0.73, respectively). The high accuracy of selection (0.86 and 0.89) associated with the high heritability of the average (0.732 and 0.794) for NKE and TKW, respectively, indicated good reliability and prospects of success in the indirect selection of hybrids with high-yield potential through these traits. The negative direct effect of NKE on TKW (r = -0.856), however, must be considered. The joint use of mixed models and sequential path analysis is effective in the evaluation of maize-breeding trials.

Physical activity in England: who is meeting the recommended level of participation through sports and exercise?

PubMed

Anokye, Nana Kwame; Pokhrel, Subhash; Buxton, Martin; Fox-Rushby, Julia

2013-06-01

Little is known about the correlates of meeting recommended levels of participation in physical activity (PA) and how this understanding informs public health policies on behaviour change. To analyse who meets the recommended level of participation in PA in males and females separately by applying 'process' modelling frameworks (single vs. sequential 2-step process). Using the Health Survey for England 2006, (n = 14 142; ≥ 16 years), gender-specific regression models were estimated using bivariate probit with selectivity correction and single probit models. A 'sequential, 2-step process' modelled participation and meeting the recommended level separately, whereas the 'single process' considered both participation and level together. In females, meeting the recommended level was associated with degree holders [Marginal effect (ME) = 0.013] and age (ME = -0.001), whereas in males, age was a significant correlate (ME = -0.003 to -0.004). The order of importance of correlates was similar across genders, with ethnicity being the most important correlate in both males (ME = -0.060) and females (ME = -0.133). In females, the 'sequential, 2-step process' performed better (ρ = -0.364, P < 0.001) than that in males (ρ = 0.154). The degree to which people undertake the recommended level of PA through vigorous activity varies between males and females, and the process that best predicts such decisions, i.e. whether it is a sequential, 2-step process or a single-step choice, is also different for males and females. Understanding this should help to identify subgroups that are less likely to meet the recommended level of PA (and hence more likely to benefit from any PA promotion intervention).

The Impact of Adjuvant Postoperative Radiation Therapy and Chemotherapy on Survival After Esophagectomy for Esophageal Carcinoma.

PubMed

Wong, Andrew T; Shao, Meng; Rineer, Justin; Lee, Anna; Schwartz, David; Schreiber, David

2017-06-01

The objective of this study was to analyze the impact on overall survival (OS) from the addition of postoperative radiation with or without chemotherapy after esophagectomy, using a large, hospital-based dataset. Previous retrospective studies have suggested an OS advantage for postoperative chemoradiation over surgery alone, although prospective data are lacking. The National Cancer Data Base was queried to select patients diagnosed with stage pT3-4Nx-0M0 or pT1-4N1-3M0 esophageal carcinoma (squamous cell or adenocarcinoma) from 1998 to 2011 treated with definitive esophagectomy ± postoperative radiation and/or chemotherapy. OS was analyzed using the Kaplan-Meier method and compared using the log-rank test. Multivariate Cox regression analysis was used to identify covariates associated with OS. There were 4893 patients selected, of whom 1153 (23.6%) received postoperative radiation. Most patients receiving radiation also received sequential/concomitant chemotherapy (89.9%). For the entire cohort, postoperative radiation was associated with a statistically significant but modest absolute improvement in survival (hazard ratio 0.77; 95% CI, 0.71-0.83; P < 0.001). On subgroup analysis, postoperative radiation was associated with improved OS for patients with node-positive disease (3-yr OS 34.3 % vs 27.8%, P < 0.001) or positive margins (3-yr OS 36.4% vs 18.0%, P < 0.001). When chemotherapy usage was incorporated, sequential chemotherapy was associated with the best survival (P < 0.001). Multivariate analysis revealed that the addition of chemotherapy to radiation therapy, whether sequentially or concurrently, was a strong prognostic factor for OS. In this hospital-based study, the addition of postoperative chemoradiation (either sequentially or concomitantly) after esophagectomy was associated with improved OS for patients with node-positive disease or positive margins.

Treating Children with Early-Onset Conduct Problems and Callous-Unemotional Traits: An Empirical Evaluation of KooLKIDS

ERIC Educational Resources Information Center

Houghton, Stephen; Carroll, Annemaree; Zadow, Corinne; O'connor, Emma Sanders; Hattie, John; Lynn, Sasha

2017-01-01

Children with early-onset conduct problems (EOCP) and callous-unemotional (CU) traits are highly resistant to treatment and cost society significantly more than their healthy counterparts. Employing a multiple baseline design, 13 males (9.0-10.2 years of age) with a history of school suspensions were sequentially introduced to KooLKIDS, a…

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM 2.5 and PM −2.5.

Code of Federal Regulations, 2014 CFR

2014-07-01

... section. All reference method samplers shall be of single-filter design (not multi-filter, sequential sample design). Each candidate method shall be setup and operated in accordance with its associated... precision specified in table C-4 of this subpart. (g) Test for additive and multiplicative bias (comparative...

40 CFR 53.35 - Test procedure for Class II and Class III methods for PM 2.5 and PM −2.5.

Code of Federal Regulations, 2013 CFR

2013-07-01

... section. All reference method samplers shall be of single-filter design (not multi-filter, sequential sample design). Each candidate method shall be setup and operated in accordance with its associated... precision specified in table C-4 of this subpart. (g) Test for additive and multiplicative bias (comparative...

Endovascular repair of multiple infrageniculate aneurysms in a patient with vascular type Ehlers-Danlos syndrome.

PubMed

Domenick, Natalie; Cho, Jae S; Abu Hamad, Ghassan; Makaroun, Michel S; Chaer, Rabih A

2011-09-01

Patients with vascular type Ehler-Danlos syndrome can develop aneurysms in unusual locations. We describe the case of a 33-year-old woman with vascular type Ehlers-Danlos syndrome who developed metachronous tibial artery aneurysms that were sequentially treated with endovascular means. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

The Development of Object Categorization in Young Children: Hierarchical Inclusiveness, Age, Perceptual Attribute, and Group versus Individual Analyses

ERIC Educational Resources Information Center

Bornstein, Marc H.; Arterberry, Martha E.

2010-01-01

Multiple levels of category inclusiveness in 4 object domains (animals, vehicles, fruit, and furniture) were examined using a sequential touching procedure and assessed in both individual and group analyses in eighty 12-, 18-, 24-, and 30-month-olds. The roles of stimulus discriminability and child motor development, fatigue, and actions were also…

Multiple laser pulse ignition method and apparatus

DOEpatents

Early, James W.

1998-01-01

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

Ridge: a computer program for calculating ridge regression estimates

Treesearch

Donald E. Hilt; Donald W. Seegrist

1977-01-01

Least-squares coefficients for multiple-regression models may be unstable when the independent variables are highly correlated. Ridge regression is a biased estimation procedure that produces stable estimates of the coefficients. Ridge regression is discussed, and a computer program for calculating the ridge coefficients is presented.

Simultaneous vs. sequential treatment for smoking and weight management in tobacco quitlines: 6 and 12 month outcomes from a randomized trial.

PubMed

Bush, Terry; Lovejoy, Jennifer; Javitz, Harold; Torres, Alula Jimenez; Wassum, Ken; Tan, Marcia M; Spring, Bonnie

2018-05-31

Smoking cessation often results in weight gain which discourages many smokers from quitting and can increase health risks. Treatments to reduce cessation-related weight gain have been tested in highly controlled trials of in-person treatment, but have never been tested in a real-world setting, which has inhibited dissemination. The Best Quit Study (BQS) is a replication and "real world" translation using telephone delivery of a prior in-person efficacy trial. randomized control trial in a quitline setting. Eligible smokers (n = 2540) were randomized to the standard 5-call quitline intervention or quitline plus simultaneous or sequential weight management. Regression analyses tested effectiveness of treatments on self-reported smoking abstinence and weight change at 6 and 12 months. Study enrollees were from 10 commercial employer groups and three state quitlines. Participants were between ages 18-72, 65.8% female, 68.2% white; 23.0% Medicaid-insured, and 76.3% overweight/obese. The follow-up response rate was lower in the simultaneous group than the control group at 6 months (p = 0.01). While a completers analysis of 30-day point prevalence abstinence detected no differences among groups at 6 or 12 months, multiply imputed abstinence showed quit rate differences at 6 months for:simultaneous (40.3%) vs. sequential (48.3%), p = 0.034 and simultaneous vs. control (44.9%), p = 0.043. At 12 months, multiply imputed abstinence, was significantly lower for the simultaneous group (40.7%) vs. control (46.0%), p < 0.05 and vs. sequential (46.3%), p < 0.05. Weight gain at 6 and 12 months was minimal and not different among treatment groups. The sequential group completed fewer total calls (3.75) vs. control (4.16) and vs. simultaneous group (3.83), p = 0.01, and fewer weight calls (0.94) than simultaneous (2.33), p < 0.0001. The number of calls completed predicted 30-day abstinence, p < 0.001, but not weight outcomes. This study offers a model for evaluating population-level public health interventions conducted in partnership with tobacco quitlines. Simultaneous (vs. sequential) delivery of phone/web weight management with cessation treatment in the quitline setting may adversely affect quit rate. Neither a simultaneous nor sequential approach to addressing weight produced any benefit on suppressing weight gain. This study highlights the need and the challenges of testing intensive interventions in real-world settings. ClinicalTrials.gov Identifier: NCT01867983 . Registered: May 30, 2013.