Modeling of a Sequential Two-Stage Combustor

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Liu, N.-S.; Gallagher, J. R.; Ryder, R. C.; Brankovic, A.; Hendricks, J. A.

2005-01-01

A sequential two-stage, natural gas fueled power generation combustion system is modeled to examine the fundamental aerodynamic and combustion characteristics of the system. The modeling methodology includes CAD-based geometry definition, and combustion computational fluid dynamics analysis. Graphical analysis is used to examine the complex vortical patterns in each component, identifying sources of pressure loss. The simulations demonstrate the importance of including the rotating high-pressure turbine blades in the computation, as this results in direct computation of combustion within the first turbine stage, and accurate simulation of the flow in the second combustion stage. The direct computation of hot-streaks through the rotating high-pressure turbine stage leads to improved understanding of the aerodynamic relationships between the primary and secondary combustors and the turbomachinery.

Time-lapse evaluation of human embryo development in single versus sequential culture media--a sibling oocyte study.

PubMed

Ciray, Haydar Nadir; Aksoy, Turan; Goktas, Cihan; Ozturk, Bilgen; Bahceci, Mustafa

2012-09-01

To compare the dynamics of early development between embryos cultured in single and sequential media. Randomized, comparative study. Private IVF centre. A total of 446 metaphase II oocytes from 51 couples who underwent oocyte retrieval procedure for intracytoplasmic sperm injection. Forty-nine resulted in embryo transfer. Oocytes were split between single and sequential media produced by the same manufacturer and cultured in a time-lapse incubator. Morphokinetic parameters until the embryos reached the 5-cell stage (t5), utilization, clinical pregnancy and implantation rates. Embryos cultured in single media were advanced from the first mitosis cycle and reached 2- to 5-cell stages earlier. There was not any difference between the durations for cell cycle two (cc2 = t3-t2) and s2 (t4-t3). The utilization, clinical pregnancy and implantation rates did not differ between groups. The proportion of cryopreserved day 6 embryos to two pronuclei oocytes was significantly higher in sequential than in single media. Morphokinetics of embryo development vary between single and sequential culture media at least until the 5-cell stage. The overall clinical and embryological parameters remain similar regardless of the culture system.

The parallel-sequential field subtraction technique for coherent nonlinear ultrasonic imaging

NASA Astrophysics Data System (ADS)

Cheng, Jingwei; Potter, Jack N.; Drinkwater, Bruce W.

2018-06-01

Nonlinear imaging techniques have recently emerged which have the potential to detect cracks at a much earlier stage than was previously possible and have sensitivity to partially closed defects. This study explores a coherent imaging technique based on the subtraction of two modes of focusing: parallel, in which the elements are fired together with a delay law and sequential, in which elements are fired independently. In the parallel focusing a high intensity ultrasonic beam is formed in the specimen at the focal point. However, in sequential focusing only low intensity signals from individual elements enter the sample and the full matrix of transmit-receive signals is recorded and post-processed to form an image. Under linear elastic assumptions, both parallel and sequential images are expected to be identical. Here we measure the difference between these images and use this to characterise the nonlinearity of small closed fatigue cracks. In particular we monitor the change in relative phase and amplitude at the fundamental frequencies for each focal point and use this nonlinear coherent imaging metric to form images of the spatial distribution of nonlinearity. The results suggest the subtracted image can suppress linear features (e.g. back wall or large scatters) effectively when instrumentation noise compensation in applied, thereby allowing damage to be detected at an early stage (c. 15% of fatigue life) and reliably quantified in later fatigue life.

Immortal time bias: a frequently unrecognized threat to validity in the evaluation of postoperative radiotherapy.

PubMed

Park, Henry S; Gross, Cary P; Makarov, Danil V; Yu, James B

2012-08-01

To evaluate the influence of immortal time bias on observational cohort studies of postoperative radiotherapy (PORT) and the effectiveness of sequential landmark analysis to account for this bias. First, we reviewed previous studies of the Surveillance, Epidemiology, and End Results (SEER) database to determine how frequently this bias was considered. Second, we used SEER to select three tumor types (glioblastoma multiforme, Stage IA-IVM0 gastric adenocarcinoma, and Stage II-III rectal carcinoma) for which prospective trials demonstrated an improvement in survival associated with PORT. For each tumor type, we calculated conditional survivals and adjusted hazard ratios of PORT vs. postoperative observation cohorts while restricting the sample at sequential monthly landmarks. Sixty-two percent of previous SEER publications evaluating PORT failed to use a landmark analysis. As expected, delivery of PORT for all three tumor types was associated with improved survival, with the largest associated benefit favoring PORT when all patients were included regardless of survival. Preselecting a cohort with a longer minimum survival sequentially diminished the apparent benefit of PORT. Although the majority of previous SEER articles do not correct for it, immortal time bias leads to altered estimates of PORT effectiveness, which are very sensitive to landmark selection. We suggest the routine use of sequential landmark analysis to account for this bias. Copyright © 2012 Elsevier Inc. All rights reserved.

Immortal Time Bias: A Frequently Unrecognized Threat to Validity in the Evaluation of Postoperative Radiotherapy

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

Park, Henry S.; Gross, Cary P.; Makarov, Danil V.

2012-08-01

Purpose: To evaluate the influence of immortal time bias on observational cohort studies of postoperative radiotherapy (PORT) and the effectiveness of sequential landmark analysis to account for this bias. Methods and Materials: First, we reviewed previous studies of the Surveillance, Epidemiology, and End Results (SEER) database to determine how frequently this bias was considered. Second, we used SEER to select three tumor types (glioblastoma multiforme, Stage IA-IVM0 gastric adenocarcinoma, and Stage II-III rectal carcinoma) for which prospective trials demonstrated an improvement in survival associated with PORT. For each tumor type, we calculated conditional survivals and adjusted hazard ratios of PORTmore » vs. postoperative observation cohorts while restricting the sample at sequential monthly landmarks. Results: Sixty-two percent of previous SEER publications evaluating PORT failed to use a landmark analysis. As expected, delivery of PORT for all three tumor types was associated with improved survival, with the largest associated benefit favoring PORT when all patients were included regardless of survival. Preselecting a cohort with a longer minimum survival sequentially diminished the apparent benefit of PORT. Conclusions: Although the majority of previous SEER articles do not correct for it, immortal time bias leads to altered estimates of PORT effectiveness, which are very sensitive to landmark selection. We suggest the routine use of sequential landmark analysis to account for this bias.« less

Sequential sampling: a novel method in farm animal welfare assessment.

PubMed

Heath, C A E; Main, D C J; Mullan, S; Haskell, M J; Browne, W J

2016-02-01

Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first 'basic' scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second 'cautious' scheme, an adaptation is made to ensure that correctly classifying a farm as 'bad' is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall association between lameness prevalence and the proportion of lame cows that were severely lame on a farm was found. However, as this association was found to not be consistent across all farms, the sampling scheme did not prove to be as useful as expected. The preferred scheme was therefore the 'cautious' scheme for which a sampling protocol has also been developed.

Sequential time interleaved random equivalent sampling for repetitive signal.

PubMed

Zhao, Yijiu; Liu, Jingjing

2016-12-01

Compressed sensing (CS) based sampling techniques exhibit many advantages over other existing approaches for sparse signal spectrum sensing; they are also incorporated into non-uniform sampling signal reconstruction to improve the efficiency, such as random equivalent sampling (RES). However, in CS based RES, only one sample of each acquisition is considered in the signal reconstruction stage, and it will result in more acquisition runs and longer sampling time. In this paper, a sampling sequence is taken in each RES acquisition run, and the corresponding block measurement matrix is constructed using a Whittaker-Shannon interpolation formula. All the block matrices are combined into an equivalent measurement matrix with respect to all sampling sequences. We implemented the proposed approach with a multi-cores analog-to-digital converter (ADC), whose ADC cores are time interleaved. A prototype realization of this proposed CS based sequential random equivalent sampling method has been developed. It is able to capture an analog waveform at an equivalent sampling rate of 40 GHz while sampled at 1 GHz physically. Experiments indicate that, for a sparse signal, the proposed CS based sequential random equivalent sampling exhibits high efficiency.

Can sequential parallel comparison design and two-way enriched design be useful in medical device clinical trials?

PubMed

Ivanova, Anastasia; Zhang, Zhiwei; Thompson, Laura; Yang, Ying; Kotz, Richard M; Fang, Xin

2016-01-01

Sequential parallel comparison design (SPCD) was proposed for trials with high placebo response. In the first stage of SPCD subjects are randomized between placebo and active treatment. In the second stage placebo nonresponders are re-randomized between placebo and active treatment. Data from the population of "all comers" and the subpopulations of placebo nonresponders then combined to yield a single p-value for treatment comparison. Two-way enriched design (TED) is an extension of SPCD where active treatment responders are also re-randomized between placebo and active treatment in Stage 2. This article investigates the potential uses of SPCD and TED in medical device trials.

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.

Identifying High-Rate Flows Based on Sequential Sampling

NASA Astrophysics Data System (ADS)

Zhang, Yu; Fang, Binxing; Luo, Hao

We consider the problem of fast identification of high-rate flows in backbone links with possibly millions of flows. Accurate identification of high-rate flows is important for active queue management, traffic measurement and network security such as detection of distributed denial of service attacks. It is difficult to directly identify high-rate flows in backbone links because tracking the possible millions of flows needs correspondingly large high speed memories. To reduce the measurement overhead, the deterministic 1-out-of-k sampling technique is adopted which is also implemented in Cisco routers (NetFlow). Ideally, a high-rate flow identification method should have short identification time, low memory cost and processing cost. Most importantly, it should be able to specify the identification accuracy. We develop two such methods. The first method is based on fixed sample size test (FSST) which is able to identify high-rate flows with user-specified identification accuracy. However, since FSST has to record every sampled flow during the measurement period, it is not memory efficient. Therefore the second novel method based on truncated sequential probability ratio test (TSPRT) is proposed. Through sequential sampling, TSPRT is able to remove the low-rate flows and identify the high-rate flows at the early stage which can reduce the memory cost and identification time respectively. According to the way to determine the parameters in TSPRT, two versions of TSPRT are proposed: TSPRT-M which is suitable when low memory cost is preferred and TSPRT-T which is suitable when short identification time is preferred. The experimental results show that TSPRT requires less memory and identification time in identifying high-rate flows while satisfying the accuracy requirement as compared to previously proposed methods.

Controlling the type I error rate in two-stage sequential adaptive designs when testing for average bioequivalence.

PubMed

Maurer, Willi; Jones, Byron; Chen, Ying

2018-05-10

In a 2×2 crossover trial for establishing average bioequivalence (ABE) of a generic agent and a currently marketed drug, the recommended approach to hypothesis testing is the two one-sided test (TOST) procedure, which depends, among other things, on the estimated within-subject variability. The power of this procedure, and therefore the sample size required to achieve a minimum power, depends on having a good estimate of this variability. When there is uncertainty, it is advisable to plan the design in two stages, with an interim sample size reestimation after the first stage, using an interim estimate of the within-subject variability. One method and 3 variations of doing this were proposed by Potvin et al. Using simulation, the operating characteristics, including the empirical type I error rate, of the 4 variations (called Methods A, B, C, and D) were assessed by Potvin et al and Methods B and C were recommended. However, none of these 4 variations formally controls the type I error rate of falsely claiming ABE, even though the amount of inflation produced by Method C was considered acceptable. A major disadvantage of assessing type I error rate inflation using simulation is that unless all possible scenarios for the intended design and analysis are investigated, it is impossible to be sure that the type I error rate is controlled. Here, we propose an alternative, principled method of sample size reestimation that is guaranteed to control the type I error rate at any given significance level. This method uses a new version of the inverse-normal combination of p-values test, in conjunction with standard group sequential techniques, that is more robust to large deviations in initial assumptions regarding the variability of the pharmacokinetic endpoints. The sample size reestimation step is based on significance levels and power requirements that are conditional on the first-stage results. This necessitates a discussion and exploitation of the peculiar properties of the power curve of the TOST testing procedure. We illustrate our approach with an example based on a real ABE study and compare the operating characteristics of our proposed method with those of Method B of Povin et al. Copyright © 2018 John Wiley & Sons, Ltd.

Improved minimum cost and maximum power two stage genome-wide association study designs.

PubMed

Stanhope, Stephen A; Skol, Andrew D

2012-01-01

In a two stage genome-wide association study (2S-GWAS), a sample of cases and controls is allocated into two groups, and genetic markers are analyzed sequentially with respect to these groups. For such studies, experimental design considerations have primarily focused on minimizing study cost as a function of the allocation of cases and controls to stages, subject to a constraint on the power to detect an associated marker. However, most treatments of this problem implicitly restrict the set of feasible designs to only those that allocate the same proportions of cases and controls to each stage. In this paper, we demonstrate that removing this restriction can improve the cost advantages demonstrated by previous 2S-GWAS designs by up to 40%. Additionally, we consider designs that maximize study power with respect to a cost constraint, and show that recalculated power maximizing designs can recover a substantial amount of the planned study power that might otherwise be lost if study funding is reduced. We provide open source software for calculating cost minimizing or power maximizing 2S-GWAS designs.

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.

The Nature of Phonological Encoding During Spoken Word Retrieval.

ERIC Educational Resources Information Center

Sullivan, Michael P.; Riffel, Brian

1999-01-01

Examined whether phonological selection occurs sequentially or in parallel. College students named picture primes and targets, with varied response stimulus intervals between primes and targets. Results were consistent with Dell's (1988) two-stage sequential model of encoding, which shows an initial parallel activation within a lexical network…

A path-level exact parallelization strategy for sequential simulation

NASA Astrophysics Data System (ADS)

Peredo, Oscar F.; Baeza, Daniel; Ortiz, Julián M.; Herrero, José R.

2018-01-01

Sequential Simulation is a well known method in geostatistical modelling. Following the Bayesian approach for simulation of conditionally dependent random events, Sequential Indicator Simulation (SIS) method draws simulated values for K categories (categorical case) or classes defined by K different thresholds (continuous case). Similarly, Sequential Gaussian Simulation (SGS) method draws simulated values from a multivariate Gaussian field. In this work, a path-level approach to parallelize SIS and SGS methods is presented. A first stage of re-arrangement of the simulation path is performed, followed by a second stage of parallel simulation for non-conflicting nodes. A key advantage of the proposed parallelization method is to generate identical realizations as with the original non-parallelized methods. Case studies are presented using two sequential simulation codes from GSLIB: SISIM and SGSIM. Execution time and speedup results are shown for large-scale domains, with many categories and maximum kriging neighbours in each case, achieving high speedup results in the best scenarios using 16 threads of execution in a single machine.

A novel acute HIV infection staging system based on 4th generation immunoassay.

PubMed

Ananworanich, Jintanat; Fletcher, James L K; Pinyakorn, Suteeraporn; van Griensven, Frits; Vandergeeten, Claire; Schuetz, Alexandra; Pankam, Tippawan; Trichavaroj, Rapee; Akapirat, Siriwat; Chomchey, Nitiya; Phanuphak, Praphan; Chomont, Nicolas; Michael, Nelson L; Kim, Jerome H; de Souza, Mark

2013-05-29

Fourth generation (4thG) immunoassay (IA) is becoming the standard HIV screening method but was not available when the Fiebig acute HIV infection (AHI) staging system was proposed. Here we evaluated AHI staging based on a 4thG IA (4thG staging). Screening for AHI was performed in real-time by pooled nucleic acid testing (NAT, n=48,828 samples) and sequential enzyme immunoassay (EIA, n=3,939 samples) identifying 63 subjects with non-reactive 2nd generation EIA (Fiebig stages I (n=25), II (n=7), III (n=29), IV (n=2)). The majority of samples tested (n=53) were subtype CRF_01AE (77%). NAT+ subjects were re-staged into three 4thG stages: stage 1 (n=20; 4th gen EIA-, 3rd gen EIA-), stage 2 (n=12; 4th gen EIA+, 3rd gen EIA-), stage 3 (n=31; 4th gen EIA+, 3rd gen EIA+, Western blot-/indeterminate). 4thG staging distinguishes groups of AHI subjects by time since presumed HIV exposure, pattern of CD8+ T, B and natural killer cell absolute numbers, and HIV RNA and DNA levels. This staging system further stratified Fiebig I subjects: 18 subjects in 4thG stage 1 had lower HIV RNA and DNA levels than 7 subjects in 4thG stage 2. Using 4th generation IA as part of AHI staging distinguishes groups of patients by time since exposure to HIV, lymphocyte numbers and HIV viral burden. It identifies two groups of Fiebig stage I subjects who display different levels of HIV RNA and DNA, which may have implication for HIV cure. 4th generation IA should be incorporated into AHI staging systems.

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.

Flexible sequential designs for multi-arm clinical trials.

PubMed

Magirr, D; Stallard, N; Jaki, T

2014-08-30

Adaptive designs that are based on group-sequential approaches have the benefit of being efficient as stopping boundaries can be found that lead to good operating characteristics with test decisions based solely on sufficient statistics. The drawback of these so called 'pre-planned adaptive' designs is that unexpected design changes are not possible without impacting the error rates. 'Flexible adaptive designs' on the other hand can cope with a large number of contingencies at the cost of reduced efficiency. In this work, we focus on two different approaches for multi-arm multi-stage trials, which are based on group-sequential ideas, and discuss how these 'pre-planned adaptive designs' can be modified to allow for flexibility. We then show how the added flexibility can be used for treatment selection and sample size reassessment and evaluate the impact on the error rates in a simulation study. The results show that an impressive overall procedure can be found by combining a well chosen pre-planned design with an application of the conditional error principle to allow flexible treatment selection. Copyright © 2014 John Wiley & Sons, Ltd.

Night sleep electroencephalogram power spectral analysis in excessive daytime sleepiness disorders.

PubMed

Reimão, R

1991-06-01

A group of 53 patients (40 males, 13 females) with mean age of 49 years, ranging from 30 to 70 years, was evaluated in the following excessive daytime sleepiness (EDS) disorders: obstructive sleep apnea syndrome (B4a), periodic movements in sleep (B5a), affective disorder (B2a), functional psychiatric non affective disorder (B2b). We considered all adult patients referred to the Center sequentially with no other distinctions but these three criteria: (a) EDS was the main complaint; (b) right handed; (c) not using psychotropic drugs for two weeks prior to the all-night polysomnography. EEG (C3/A1, C4/A2) samples from 2 to 10 minutes of each stage of the first REM cycle were chosen. The data was recorded simultaneously in magnetic tape and then fed into a computer for power spectral analysis. The percentage of power (PP) in each band calculated in relation to the total EEG power was determined of subsequent sections of 20.4 s for the following frequency bands: delta, theta, alpha and beta. The PP in all EDS patients sample had a tendency to decrease progressively from the slowest to the fastest frequency bands, in every sleep stage. PP distribution in the delta range increased progressively from stage 1 to stage 4; stage REM levels were close to stage 2 levels. In an EDS patients interhemispheric coherence was high in every band and sleep stage. B4a patients sample PP had a tendency to decrease progressively from the slowest to the fastest frequency bands, in every sleep stage; PP distribution in the delta range increased progressively from stage 1 to stage 4; stage REM levels were between stage 1 and stage 2 levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Diffusion tensor imaging analysis of sequential spreading of disease in amyotrophic lateral sclerosis confirms patterns of TDP-43 pathology.

PubMed

Kassubek, Jan; Müller, Hans-Peter; Del Tredici, Kelly; Brettschneider, Johannes; Pinkhardt, Elmar H; Lulé, Dorothée; Böhm, Sarah; Braak, Heiko; Ludolph, Albert C

2014-06-01

Diffusion tensor imaging can identify amyotrophic lateral sclerosis-associated patterns of brain alterations at the group level. Recently, a neuropathological staging system for amyotrophic lateral sclerosis has shown that amyotrophic lateral sclerosis may disseminate in a sequential regional pattern during four disease stages. The objective of the present study was to apply a new methodological diffusion tensor imaging-based approach to automatically analyse in vivo the fibre tracts that are prone to be involved at each neuropathological stage of amyotrophic lateral sclerosis. Two data samples, consisting of 130 diffusion tensor imaging data sets acquired at 1.5 T from 78 patients with amyotrophic lateral sclerosis and 52 control subjects; and 55 diffusion-tensor imaging data sets at 3.0 T from 33 patients with amyotrophic lateral sclerosis and 22 control subjects, were analysed by a tract of interest-based fibre tracking approach to analyse five tracts that become involved during the course of amyotrophic lateral sclerosis: the corticospinal tract (stage 1); the corticorubral and the corticopontine tracts (stage 2); the corticostriatal pathway (stage 3); the proximal portion of the perforant path (stage 4); and two reference pathways. The statistical analyses of tracts of interest showed differences between patients with amyotrophic lateral sclerosis and control subjects for all tracts. The significance level of the comparisons at the group level was lower, the higher the disease stage with corresponding involved fibre tracts. Both the clinical phenotype as assessed by the amyotrophic lateral sclerosis functional rating scale-revised and disease duration correlated significantly with the resulting staging scheme. In summary, the tract of interest-based technique allowed for individual analysis of predefined tract structures, thus making it possible to image in vivo the disease stages in amyotrophic lateral sclerosis. This approach can be used not only for individual clinical work-up purposes, but enlarges the spectrum of potential non-invasive surrogate markers as a neuroimaging-based read-out for amyotrophic lateral sclerosis studies within a clinical context. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

PubMed

Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

2014-04-01

A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Group-sequential three-arm noninferiority clinical trial designs

PubMed Central

Ochiai, Toshimitsu; Hamasaki, Toshimitsu; Evans, Scott R.; Asakura, Koko; Ohno, Yuko

2016-01-01

We discuss group-sequential three-arm noninferiority clinical trial designs that include active and placebo controls for evaluating both assay sensitivity and noninferiority. We extend two existing approaches, the fixed margin and fraction approaches, into a group-sequential setting with two decision-making frameworks. We investigate the operating characteristics including power, Type I error rate, maximum and expected sample sizes, as design factors vary. In addition, we discuss sample size recalculation and its’ impact on the power and Type I error rate via a simulation study. PMID:26892481

Sequential air sampler system : its use by the Virginia Department of Highways & Transportation.

DOT National Transportation Integrated Search

1975-01-01

The Department of Highways & Transportation needs an economical and efficient air quality sampling system for meeting requirements on air monitoring for proposed projects located In critical areas. Two sequential air sampling systems, the ERAI and th...

Evaluation of sequential extraction procedures for soluble and insoluble hexavalent chromium compounds in workplace air samples.

PubMed

Ashley, Kevin; Applegate, Gregory T; Marcy, A Dale; Drake, Pamela L; Pierce, Paul A; Carabin, Nathalie; Demange, Martine

2009-02-01

Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16740 have been published that describe sequential extraction techniques for soluble and insoluble Cr(VI) in samples collected from occupational settings. However, no published performance data were previously available for these Cr(VI) sequential extraction procedures. In this work, the sequential extraction methods outlined in the relevant international standards were investigated. The procedures tested involved the use of either deionized water or an ammonium sulfate/ammonium hydroxide buffer solution to target soluble Cr(VI) species. This was followed by extraction in a sodium carbonate/sodium hydroxide buffer solution to dissolve insoluble Cr(VI) compounds. Three-step sequential extraction with (1) water, (2) sulfate buffer and (3) carbonate buffer was also investigated. Sequential extractions were carried out on spiked samples of soluble, sparingly soluble and insoluble Cr(VI) compounds, and analyses were then generally carried out by using the diphenylcarbazide method. Similar experiments were performed on paint pigment samples and on airborne particulate filter samples collected from stainless steel welding. Potential interferences from soluble and insoluble Cr(III) compounds, as well as from Fe(II), were investigated. Interferences from Cr(III) species were generally absent, while the presence of Fe(II) resulted in low Cr(VI) recoveries. Two-step sequential extraction of spiked samples with (first) either water or sulfate buffer, and then carbonate buffer, yielded quantitative recoveries of soluble Cr(VI) and insoluble Cr(VI), respectively. Three-step sequential extraction gave excessively high recoveries of soluble Cr(VI), low recoveries of sparingly soluble Cr(VI), and quantitative recoveries of insoluble Cr(VI). Experiments on paint pigment samples using two-step extraction with water and carbonate buffer yielded varying percentages of relative fractions of soluble and insoluble Cr(VI). Sequential extractions of stainless steel welding fume air filter samples demonstrated the predominance of soluble Cr(VI) compounds in such samples. The performance data obtained in this work support the Cr(VI) sequential extraction procedures described in the international standards.

Temperature-assisted solute focusing with sequential trap/release zones in isocratic and gradient capillary liquid chromatography: Simulation and experiment

PubMed Central

Groskreutz, Stephen R.; Weber, Stephen G.

2016-01-01

In this work we characterize the development of a method to enhance temperature-assisted on-column solute focusing (TASF) called two-stage TASF. A new instrument was built to implement two-stage TASF consisting of a linear array of three independent, electronically controlled Peltier devices (thermoelectric coolers, TECs). Samples are loaded onto the chromatographic column with the first two TECs, TEC A and TEC B, cold. In the two-stage TASF approach TECs A and B are cooled during injection. TEC A is heated following sample loading. At some time following TEC A’s temperature rise, TEC B’s temperature is increased from the focusing temperature to a temperature matching that of TEC A. Injection bands are focused twice on-column, first on the initial TEC, e.g. single-stage TASF, then refocused on the second, cold TEC. Our goal is to understand the two-stage TASF approach in detail. We have developed a simple yet powerful digital simulation procedure to model the effect of changing temperature in the two focusing zones on retention, band shape and band spreading. The simulation can predict experimental chromatograms resulting from spatial and temporal temperature programs in combination with isocratic and solvent gradient elution. To assess the two-stage TASF method and the accuracy of the simulation well characterized solutes are needed. Thus, retention factors were measured at six temperatures (25–75 °C) at each of twelve mobile phases compositions (0.05–0.60 acetonitrile/water) for homologs of n-alkyl hydroxylbenzoate esters and n-alkyl p-hydroxyphenones. Simulations accurately reflect experimental results in showing that the two-stage approach improves separation quality. For example, two-stage TASF increased sensitivity for a low retention solute by a factor of 2.2 relative to single-stage TASF and 8.8 relative to isothermal conditions using isocratic elution. Gradient elution results for two-stage TASF were more encouraging. Application of two-stage TASF increased peak height for the least retained solute in the test mixture by a factor of 3.2 relative to single-stage TASF and 22.3 compared to isothermal conditions for an injection four-times the column volume. TASF improved resolution and increased peak capacity; for a 12-minute separation peak capacity increased from 75 under isothermal conditions to 146 using single-stage TASF, and 185 for two-stage TASF. PMID:27836226

Temperature-assisted solute focusing with sequential trap/release zones in isocratic and gradient capillary liquid chromatography: Simulation and experiment.

PubMed

Groskreutz, Stephen R; Weber, Stephen G

2016-11-25

In this work we characterize the development of a method to enhance temperature-assisted on-column solute focusing (TASF) called two-stage TASF. A new instrument was built to implement two-stage TASF consisting of a linear array of three independent, electronically controlled Peltier devices (thermoelectric coolers, TECs). Samples are loaded onto the chromatographic column with the first two TECs, TEC A and TEC B, cold. In the two-stage TASF approach TECs A and B are cooled during injection. TEC A is heated following sample loading. At some time following TEC A's temperature rise, TEC B's temperature is increased from the focusing temperature to a temperature matching that of TEC A. Injection bands are focused twice on-column, first on the initial TEC, e.g. single-stage TASF, then refocused on the second, cold TEC. Our goal is to understand the two-stage TASF approach in detail. We have developed a simple yet powerful digital simulation procedure to model the effect of changing temperature in the two focusing zones on retention, band shape and band spreading. The simulation can predict experimental chromatograms resulting from spatial and temporal temperature programs in combination with isocratic and solvent gradient elution. To assess the two-stage TASF method and the accuracy of the simulation well characterized solutes are needed. Thus, retention factors were measured at six temperatures (25-75°C) at each of twelve mobile phases compositions (0.05-0.60 acetonitrile/water) for homologs of n-alkyl hydroxylbenzoate esters and n-alkyl p-hydroxyphenones. Simulations accurately reflect experimental results in showing that the two-stage approach improves separation quality. For example, two-stage TASF increased sensitivity for a low retention solute by a factor of 2.2 relative to single-stage TASF and 8.8 relative to isothermal conditions using isocratic elution. Gradient elution results for two-stage TASF were more encouraging. Application of two-stage TASF increased peak height for the least retained solute in the test mixture by a factor of 3.2 relative to single-stage TASF and 22.3 compared to isothermal conditions for an injection four-times the column volume. TASF improved resolution and increased peak capacity; for a 12-min separation peak capacity increased from 75 under isothermal conditions to 146 using single-stage TASF, and 185 for two-stage TASF. Copyright © 2016 Elsevier B.V. All rights reserved.

[Sequential sampling plans to Orthezia praelonga Douglas (Hemiptera: Sternorrhyncha, Ortheziidae) in citrus].

PubMed

Costa, Marilia G; Barbosa, José C; Yamamoto, Pedro T

2007-01-01

The sequential sampling is characterized by using samples of variable sizes, and has the advantage of reducing sampling time and costs if compared to fixed-size sampling. To introduce an adequate management for orthezia, sequential sampling plans were developed for orchards under low and high infestation. Data were collected in Matão, SP, in commercial stands of the orange variety 'Pêra Rio', at five, nine and 15 years of age. Twenty samplings were performed in the whole area of each stand by observing the presence or absence of scales on plants, being plots comprised of ten plants. After observing that in all of the three stands the scale population was distributed according to the contagious model, fitting the Negative Binomial Distribution in most samplings, two sequential sampling plans were constructed according to the Sequential Likelihood Ratio Test (SLRT). To construct these plans an economic threshold of 2% was adopted and the type I and II error probabilities were fixed in alpha = beta = 0.10. Results showed that the maximum numbers of samples expected to determine control need were 172 and 76 samples for stands with low and high infestation, respectively.

Sample size determination in group-sequential clinical trials with two co-primary endpoints

PubMed Central

Asakura, Koko; Hamasaki, Toshimitsu; Sugimoto, Tomoyuki; Hayashi, Kenichi; Evans, Scott R; Sozu, Takashi

2014-01-01

We discuss sample size determination in group-sequential designs with two endpoints as co-primary. We derive the power and sample size within two decision-making frameworks. One is to claim the test intervention’s benefit relative to control when superiority is achieved for the two endpoints at the same interim timepoint of the trial. The other is when the superiority is achieved for the two endpoints at any interim timepoint, not necessarily simultaneously. We evaluate the behaviors of sample size and power with varying design elements and provide a real example to illustrate the proposed sample size methods. In addition, we discuss sample size recalculation based on observed data and evaluate the impact on the power and Type I error rate. PMID:24676799

[Two-stage hepatectomy for hepatic metastasis and supra renal vena cava reconstruction].

PubMed

Nicoluzzi, João Eduardo

2012-12-01

Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection. Herein we report the tecnical aspects of the management of a thirty-seven years-old woman with colorectal metastasis to the liver eligible because single resection could not achieve complete treatment, even in combination with chemotherapy, portal embolization, or radiofrequency, but tumors could be totally removed by two sequential resections.

Sampling strategies for subsampled segmented EPI PRF thermometry in MR guided high intensity focused ultrasound

PubMed Central

Odéen, Henrik; Todd, Nick; Diakite, Mahamadou; Minalga, Emilee; Payne, Allison; Parker, Dennis L.

2014-01-01

Purpose: To investigate k-space subsampling strategies to achieve fast, large field-of-view (FOV) temperature monitoring using segmented echo planar imaging (EPI) proton resonance frequency shift thermometry for MR guided high intensity focused ultrasound (MRgHIFU) applications. Methods: Five different k-space sampling approaches were investigated, varying sample spacing (equally vs nonequally spaced within the echo train), sampling density (variable sampling density in zero, one, and two dimensions), and utilizing sequential or centric sampling. Three of the schemes utilized sequential sampling with the sampling density varied in zero, one, and two dimensions, to investigate sampling the k-space center more frequently. Two of the schemes utilized centric sampling to acquire the k-space center with a longer echo time for improved phase measurements, and vary the sampling density in zero and two dimensions, respectively. Phantom experiments and a theoretical point spread function analysis were performed to investigate their performance. Variable density sampling in zero and two dimensions was also implemented in a non-EPI GRE pulse sequence for comparison. All subsampled data were reconstructed with a previously described temporally constrained reconstruction (TCR) algorithm. Results: The accuracy of each sampling strategy in measuring the temperature rise in the HIFU focal spot was measured in terms of the root-mean-square-error (RMSE) compared to fully sampled “truth.” For the schemes utilizing sequential sampling, the accuracy was found to improve with the dimensionality of the variable density sampling, giving values of 0.65 °C, 0.49 °C, and 0.35 °C for density variation in zero, one, and two dimensions, respectively. The schemes utilizing centric sampling were found to underestimate the temperature rise, with RMSE values of 1.05 °C and 1.31 °C, for variable density sampling in zero and two dimensions, respectively. Similar subsampling schemes with variable density sampling implemented in zero and two dimensions in a non-EPI GRE pulse sequence both resulted in accurate temperature measurements (RMSE of 0.70 °C and 0.63 °C, respectively). With sequential sampling in the described EPI implementation, temperature monitoring over a 192 × 144 × 135 mm3 FOV with a temporal resolution of 3.6 s was achieved, while keeping the RMSE compared to fully sampled “truth” below 0.35 °C. Conclusions: When segmented EPI readouts are used in conjunction with k-space subsampling for MR thermometry applications, sampling schemes with sequential sampling, with or without variable density sampling, obtain accurate phase and temperature measurements when using a TCR reconstruction algorithm. Improved temperature measurement accuracy can be achieved with variable density sampling. Centric sampling leads to phase bias, resulting in temperature underestimations. PMID:25186406

Cost-effective binomial sequential sampling of western bean cutworm, Striacosta albicosta (Lepidoptera: Noctuidae), egg masses in corn.

PubMed

Paula-Moraes, S; Burkness, E C; Hunt, T E; Wright, R J; Hein, G L; Hutchison, W D

2011-12-01

Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a native pest of dry beans (Phaseolus vulgaris L.) and corn (Zea mays L.). As a result of larval feeding damage on corn ears, S. albicosta has a narrow treatment window; thus, early detection of the pest in the field is essential, and egg mass sampling has become a popular monitoring tool. Three action thresholds for field and sweet corn currently are used by crop consultants, including 4% of plants infested with egg masses on sweet corn in the silking-tasseling stage, 8% of plants infested with egg masses on field corn with approximately 95% tasseled, and 20% of plants infested with egg masses on field corn during mid-milk-stage corn. The current monitoring recommendation is to sample 20 plants at each of five locations per field (100 plants total). In an effort to develop a more cost-effective sampling plan for S. albicosta egg masses, several alternative binomial sampling plans were developed using Wald's sequential probability ratio test, and validated using Resampling for Validation of Sampling Plans (RVSP) software. The benefit-cost ratio also was calculated and used to determine the final selection of sampling plans. Based on final sampling plans selected for each action threshold, the average sample number required to reach a treat or no-treat decision ranged from 38 to 41 plants per field. This represents a significant savings in sampling cost over the current recommendation of 100 plants.

One-stage sequential bilateral thoracic expansion for asphyxiating thoracic dystrophy (Jeune syndrome).

PubMed

Muthialu, Nagarajan; Mussa, Shafi; Owens, Catherine M; Bulstrode, Neil; Elliott, Martin J

2014-10-01

Jeune syndrome (asphyxiating thoracic dystrophy) is a rare disorder characterized by skeletal dysplasia, reduced diameter of the thoracic cage and extrathoracic organ involvement. Fatal, early respiratory insufficiency may occur. Two-stage lateral thoracic expansion has been reported, addressing each side sequentially over 3-12 months. While staged repair theoretically provides less invasive surgery in a small child with respiratory distress, we utilized a single stage, bilateral procedure aiming to rapidly maximize lung development. Combined bilateral surgery also offered the chance of rapid recovery, and reduced hospital stay. We present our early experience of this modification of existing surgical treatment for an extremely rare condition, thought to be generally fatal in early childhood. Nine children (6 males, 3 females; median age 30 months [3.5-75]) underwent thoracic expansion for Jeune syndrome in our centre. All patients required preoperative respiratory support (5 with tracheostomy, 8 requiring positive pressure ventilation regularly within each day/night cycle). Two children underwent sequential unilateral (2-month interval between stages) and 7 children bilateral thoracic expansion by means of staggered osteotomies of third to eighth ribs and plate fixation of fourth to fifth rib and sixth to seventh rib, leaving the remaining ribs floating. There was no operative mortality. There were 2 deaths within 3 months of surgery, due to pulmonary hypertension (1 following two-stage and 1 following single-stage thoracic expansion). At the median follow-up of 11 months (1-15), 3 children have been discharged home from their referring unit and 2 have significantly reduced respiratory support. One child remains on non-invasive ventilation and another is still ventilated with a high oxygen requirement. Jeune syndrome is a difficult condition to manage, but bilateral thoracic expansion offers an effective reduction in ventilator requirements in these children. While two-stage repair has been described previously, this is the first report of single-stage bilateral thoracic expansion. Single-stage repair is feasible and may offer better resource management and significant cost savings by potentially reducing theatre usage and overall length of stay (intensive care and hospital) without compromising clinical outcomes. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Handling missing values in the MDS-UPDRS.

PubMed

Goetz, Christopher G; Luo, Sheng; Wang, Lu; Tilley, Barbara C; LaPelle, Nancy R; Stebbins, Glenn T

2015-10-01

This study was undertaken to define the number of missing values permissible to render valid total scores for each Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part. To handle missing values, imputation strategies serve as guidelines to reject an incomplete rating or create a surrogate score. We tested a rigorous, scale-specific, data-based approach to handling missing values for the MDS-UPDRS. From two large MDS-UPDRS datasets, we sequentially deleted item scores, either consistently (same items) or randomly (different items) across all subjects. Lin's Concordance Correlation Coefficient (CCC) compared scores calculated without missing values with prorated scores based on sequentially increasing missing values. The maximal number of missing values retaining a CCC greater than 0.95 determined the threshold for rendering a valid prorated score. A second confirmatory sample was selected from the MDS-UPDRS international translation program. To provide valid part scores applicable across all Hoehn and Yahr (H&Y) stages when the same items are consistently missing, one missing item from Part I, one from Part II, three from Part III, but none from Part IV can be allowed. To provide valid part scores applicable across all H&Y stages when random item entries are missing, one missing item from Part I, two from Part II, seven from Part III, but none from Part IV can be allowed. All cutoff values were confirmed in the validation sample. These analyses are useful for constructing valid surrogate part scores for MDS-UPDRS when missing items fall within the identified threshold and give scientific justification for rejecting partially completed ratings that fall below the threshold. © 2015 International Parkinson and Movement Disorder Society.

C-reactive protein as a marker of melanoma progression.

PubMed

Fang, Shenying; Wang, Yuling; Sui, Dawen; Liu, Huey; Ross, Merrick I; Gershenwald, Jeffrey E; Cormier, Janice N; Royal, Richard E; Lucci, Anthony; Schacherer, Christopher W; Gardner, Julie M; Reveille, John D; Bassett, Roland L; Wang, Li-E; Wei, Qingyi; Amos, Christopher I; Lee, Jeffrey E

2015-04-20

To investigate the association between blood levels of C-reactive protein (CRP) in patients with melanoma and overall survival (OS), melanoma-specific survival (MSS), and disease-free survival. Two independent sets of plasma samples from a total of 1,144 patients with melanoma (587 initial and 557 confirmatory) were available for CRP determination. Kaplan-Meier method and Cox regression were used to evaluate the relationship between CRP and clinical outcome. Among 115 patients who underwent sequential blood draws, we evaluated the relationship between change in disease status and change in CRP using nonparametric tests. Elevated CRP level was associated with poorer OS and MSS in the initial, confirmatory, and combined data sets (combined data set: OS hazard ratio, 1.44 per unit increase of logarithmic CRP; 95% CI, 1.30 to 1.59; P < .001; MSS hazard ratio, 1.51 per unit increase of logarithmic CRP; 95% CI, 1.36 to 1.68; P < .001). These findings persisted after multivariable adjustment. As compared with CRP < 10 mg/L, CRP ≥ 10 mg/L conferred poorer OS in patients with any-stage, stage I/II, or stage III/IV disease and poorer disease-free survival in those with stage I/II disease. In patients who underwent sequential evaluation of CRP, an association was identified between an increase in CRP and melanoma disease progression. CRP is an independent prognostic marker in patients with melanoma. CRP measurement should be considered for incorporation into prospective studies of outcome in patients with melanoma and clinical trials of systemic therapies for those with melanoma. © 2015 by American Society of Clinical Oncology.

C-Reactive Protein As a Marker of Melanoma Progression

PubMed Central

Fang, Shenying; Wang, Yuling; Sui, Dawen; Liu, Huey; Ross, Merrick I.; Gershenwald, Jeffrey E.; Cormier, Janice N.; Royal, Richard E.; Lucci, Anthony; Schacherer, Christopher W.; Gardner, Julie M.; Reveille, John D.; Bassett, Roland L.; Wang, Li-E; Wei, Qingyi; Amos, Christopher I.; Lee, Jeffrey E.

2015-01-01

Purpose To investigate the association between blood levels of C-reactive protein (CRP) in patients with melanoma and overall survival (OS), melanoma-specific survival (MSS), and disease-free survival. Patients and Methods Two independent sets of plasma samples from a total of 1,144 patients with melanoma (587 initial and 557 confirmatory) were available for CRP determination. Kaplan-Meier method and Cox regression were used to evaluate the relationship between CRP and clinical outcome. Among 115 patients who underwent sequential blood draws, we evaluated the relationship between change in disease status and change in CRP using nonparametric tests. Results Elevated CRP level was associated with poorer OS and MSS in the initial, confirmatory, and combined data sets (combined data set: OS hazard ratio, 1.44 per unit increase of logarithmic CRP; 95% CI, 1.30 to 1.59; P < .001; MSS hazard ratio, 1.51 per unit increase of logarithmic CRP; 95% CI, 1.36 to 1.68; P < .001). These findings persisted after multivariable adjustment. As compared with CRP < 10 mg/L, CRP ≥ 10 mg/L conferred poorer OS in patients with any-stage, stage I/II, or stage III/IV disease and poorer disease-free survival in those with stage I/II disease. In patients who underwent sequential evaluation of CRP, an association was identified between an increase in CRP and melanoma disease progression. Conclusion CRP is an independent prognostic marker in patients with melanoma. CRP measurement should be considered for incorporation into prospective studies of outcome in patients with melanoma and clinical trials of systemic therapies for those with melanoma. PMID:25779565

Feasibility of bioengineered two-stages sequential batch reactor and filtration-adsorption process for complex agrochemical effluent.

PubMed

Manekar, Pravin; Biswas, Rima; Urewar, Chaitali; Pal, Sukdeb; Nandy, Tapas

2013-11-01

In the present study, the feasibility of a bioengineered two-stages sequential batch reactor (BTSSBR) followed by filtration-adsorption process was investigated to treat the agrochemical effluent by overcoming factor affecting process stability such as microbial imbalance and substrate sensitivity. An air stripper stripped 90% of toxic ammonia, and combined with other streams for bio-oxidation and filtration-adsorption. The BTSSBR system achieved bio-oxidation at 6 days hydraulic retention time by fending off microbial imbalance and substrate sensitivity. The maximum reduction in COD and BOD by heterotrophic bacteria in the first reactor was 87% and 90%, respectively. Removal of toxic ammoniacal-nitrogen by autotrophic bacteria in a post-second stage bio-oxidation was 97%. The optimum filtration and adsorption of pollutants were achieved at a filtration rate of 10 and 9 m(3)m(-2)h(-1), respectively. The treatment scheme comprising air stripper, BTSSBR and filtration-adsorption process showed a great promise for treating the agrochemical effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sampling strategies for subsampled segmented EPI PRF thermometry in MR guided high intensity focused ultrasound

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

Odéen, Henrik, E-mail: h.odeen@gmail.com; Diakite, Mahamadou; Todd, Nick

2014-09-15

Purpose: To investigate k-space subsampling strategies to achieve fast, large field-of-view (FOV) temperature monitoring using segmented echo planar imaging (EPI) proton resonance frequency shift thermometry for MR guided high intensity focused ultrasound (MRgHIFU) applications. Methods: Five different k-space sampling approaches were investigated, varying sample spacing (equally vs nonequally spaced within the echo train), sampling density (variable sampling density in zero, one, and two dimensions), and utilizing sequential or centric sampling. Three of the schemes utilized sequential sampling with the sampling density varied in zero, one, and two dimensions, to investigate sampling the k-space center more frequently. Two of the schemesmore » utilized centric sampling to acquire the k-space center with a longer echo time for improved phase measurements, and vary the sampling density in zero and two dimensions, respectively. Phantom experiments and a theoretical point spread function analysis were performed to investigate their performance. Variable density sampling in zero and two dimensions was also implemented in a non-EPI GRE pulse sequence for comparison. All subsampled data were reconstructed with a previously described temporally constrained reconstruction (TCR) algorithm. Results: The accuracy of each sampling strategy in measuring the temperature rise in the HIFU focal spot was measured in terms of the root-mean-square-error (RMSE) compared to fully sampled “truth.” For the schemes utilizing sequential sampling, the accuracy was found to improve with the dimensionality of the variable density sampling, giving values of 0.65 °C, 0.49 °C, and 0.35 °C for density variation in zero, one, and two dimensions, respectively. The schemes utilizing centric sampling were found to underestimate the temperature rise, with RMSE values of 1.05 °C and 1.31 °C, for variable density sampling in zero and two dimensions, respectively. Similar subsampling schemes with variable density sampling implemented in zero and two dimensions in a non-EPI GRE pulse sequence both resulted in accurate temperature measurements (RMSE of 0.70 °C and 0.63 °C, respectively). With sequential sampling in the described EPI implementation, temperature monitoring over a 192 × 144 × 135 mm{sup 3} FOV with a temporal resolution of 3.6 s was achieved, while keeping the RMSE compared to fully sampled “truth” below 0.35 °C. Conclusions: When segmented EPI readouts are used in conjunction with k-space subsampling for MR thermometry applications, sampling schemes with sequential sampling, with or without variable density sampling, obtain accurate phase and temperature measurements when using a TCR reconstruction algorithm. Improved temperature measurement accuracy can be achieved with variable density sampling. Centric sampling leads to phase bias, resulting in temperature underestimations.« less

Career Development in the College Years.

ERIC Educational Resources Information Center

Myers, Roger A.

This paper concerns itself with two relatively central issues in career development, life stages and choice behavior and focuses on the tasks of the college counselor in regards to them. Life stages refer to sequential series of tasks to be accomplished within time periods that can be specified. Choice behavior is the on-going process of making a…

Treatment of Middle East Respiratory Syndrome with a combination of lopinavir-ritonavir and interferon-β1b (MIRACLE trial): study protocol for a randomized controlled trial.

PubMed

Arabi, Yaseen M; Alothman, Adel; Balkhy, Hanan H; Al-Dawood, Abdulaziz; AlJohani, Sameera; Al Harbi, Shmeylan; Kojan, Suleiman; Al Jeraisy, Majed; Deeb, Ahmad M; Assiri, Abdullah M; Al-Hameed, Fahad; AlSaedi, Asim; Mandourah, Yasser; Almekhlafi, Ghaleb A; Sherbeeni, Nisreen Murad; Elzein, Fatehi Elnour; Memon, Javed; Taha, Yusri; Almotairi, Abdullah; Maghrabi, Khalid A; Qushmaq, Ismael; Al Bshabshe, Ali; Kharaba, Ayman; Shalhoub, Sarah; Jose, Jesna; Fowler, Robert A; Hayden, Frederick G; Hussein, Mohamed A

2018-01-30

It had been more than 5 years since the first case of Middle East Respiratory Syndrome coronavirus infection (MERS-CoV) was recorded, but no specific treatment has been investigated in randomized clinical trials. Results from in vitro and animal studies suggest that a combination of lopinavir/ritonavir and interferon-β1b (IFN-β1b) may be effective against MERS-CoV. The aim of this study is to investigate the efficacy of treatment with a combination of lopinavir/ritonavir and recombinant IFN-β1b provided with standard supportive care, compared to treatment with placebo provided with standard supportive care in patients with laboratory-confirmed MERS requiring hospital admission. The protocol is prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. Hospitalized adult patients with laboratory-confirmed MERS will be enrolled in this recursive, two-stage, group sequential, multicenter, placebo-controlled, double-blind randomized controlled trial. The trial is initially designed to include 2 two-stage components. The first two-stage component is designed to adjust sample size and determine futility stopping, but not efficacy stopping. The second two-stage component is designed to determine efficacy stopping and possibly readjustment of sample size. The primary outcome is 90-day mortality. This will be the first randomized controlled trial of a potential treatment for MERS. The study is sponsored by King Abdullah International Medical Research Center, Riyadh, Saudi Arabia. Enrollment for this study began in November 2016, and has enrolled thirteen patients as of Jan 24-2018. ClinicalTrials.gov, ID: NCT02845843 . Registered on 27 July 2016.

Towards the Integration of Dark- and Photo-Fermentative Waste Treatment. 4. Repeated Batch Sequential Dark- and Photofermentation using Starch as Substrate

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

Laurinavichene, T. V.; Belokopytov, B. F.; Laurinavichius, K. S.

In this study we demonstrated the technical feasibility of a prolonged, sequential two-stage integrated process under a repeated batch mode of starch fermentation. In this durable scheme, the photobioreactor with purple bacteria in the second stage was fed directly with dark culture from the first stage without centrifugation, filtration, or sterilization (not demonstrated previously). After preliminary optimization, both the dark- and the photo-stages were performed under repeated batch modes with different process parameters. Continuous H{sub 2} production in this system was observed at a H{sub 2} yield of up to 1.4 and 3.9 mole mole{sup -1} hexose during the dark-more » and photo-stage, respectively (for a total of 5.3 mole mole{sup -1} hexose), and rates of 0.9 and 0.5 L L{sup -1} d{sup -1}, respectively. Prolonged repeated batch H{sub 2} production was maintained for up to 90 days in each stage and was rather stable under non-aseptic conditions. Potential for improvements in these results are discussed.« less

Randomized open-label non-comparative multicenter phase II trial of sequential erlotinib and docetaxel versus docetaxel alone in patients with non-small-cell lung cancer after failure of first-line chemotherapy: GFPC 10.02 study.

PubMed

Auliac, J B; Chouaid, C; Greillier, L; Greiller, L; Monnet, I; Le Caer, H; Falchero, L; Corre, R; Descourt, R; Bota, S; Berard, H; Schott, R; Bizieux, A; Fournel, P; Labrunie, A; Marin, B; Vergnenegre, A

2014-09-01

Concomitant administration of erlotinib with standard chemotherapy does not appear to improve survival among patients with non-small-cell lung cancer (NSCLC), but preliminary studies suggest that sequential administration might be effective. To assess the efficacy and tolerability of second-line sequential administration of erlotinib and docetaxel in advanced NSCLC. In an open-label phase II trial, patients with advanced NSCLC, EGFR wild-type or unknown, PS 0-2, in whom initial cisplatin-based chemotherapy had failed were randomized to sequential erlotinib 150 mg/d (day 2-16)+docetaxel (75 mg/m(2) d1) (arm ED) or docetaxel (75 mg/m(2) d1) alone (arm D) (21-day cycle). The primary endpoint was the progression-free survival rate at 15 weeks (PFS 15). Secondary endpoints included PFS, overall survival (OS), the overall response rate (ORR) and tolerability. Based on a Simon optimal two-stage design, the ED strategy was rejected if the primary endpoint was below 33/66 patients at the end of the two Simon stages. 147 patients were randomized (median age: 60±8 years, PS 0/1/2: 44/83/20 patients; males: 78%). The ED strategy was rejected, with only 18 of 73 patients achieving PFS15 in arm ED at the end of stage 2 and 17 of 74 patients in arm D. In arms ED and D, respectively, median PFS was 2.2 and 2.5 months and median OS was 6.5 and 8.3 months. Sequential erlotinib and docetaxel was not more effective than docetaxel alone as second-line treatment for advanced NSCLC with wild-type or unknown EGFR status. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Could the clinical interpretability of subgroups detected using clustering methods be improved by using a novel two-stage approach?

PubMed

Kent, Peter; Stochkendahl, Mette Jensen; Christensen, Henrik Wulff; Kongsted, Alice

2015-01-01

Recognition of homogeneous subgroups of patients can usefully improve prediction of their outcomes and the targeting of treatment. There are a number of research approaches that have been used to recognise homogeneity in such subgroups and to test their implications. One approach is to use statistical clustering techniques, such as Cluster Analysis or Latent Class Analysis, to detect latent relationships between patient characteristics. Influential patient characteristics can come from diverse domains of health, such as pain, activity limitation, physical impairment, social role participation, psychological factors, biomarkers and imaging. However, such 'whole person' research may result in data-driven subgroups that are complex, difficult to interpret and challenging to recognise clinically. This paper describes a novel approach to applying statistical clustering techniques that may improve the clinical interpretability of derived subgroups and reduce sample size requirements. This approach involves clustering in two sequential stages. The first stage involves clustering within health domains and therefore requires creating as many clustering models as there are health domains in the available data. This first stage produces scoring patterns within each domain. The second stage involves clustering using the scoring patterns from each health domain (from the first stage) to identify subgroups across all domains. We illustrate this using chest pain data from the baseline presentation of 580 patients. The new two-stage clustering resulted in two subgroups that approximated the classic textbook descriptions of musculoskeletal chest pain and atypical angina chest pain. The traditional single-stage clustering resulted in five clusters that were also clinically recognisable but displayed less distinct differences. In this paper, a new approach to using clustering techniques to identify clinically useful subgroups of patients is suggested. Research designs, statistical methods and outcome metrics suitable for performing that testing are also described. This approach has potential benefits but requires broad testing, in multiple patient samples, to determine its clinical value. The usefulness of the approach is likely to be context-specific, depending on the characteristics of the available data and the research question being asked of it.

Stage III and oestrogen receptor negativity are associated with poor prognosis after adjuvant high-dose therapy in high-risk breast cancer

PubMed Central

Hohaus, S; Funk, L; Martin, S; Schlenk, R F; Abdallah, A; Hahn, U; Egerer, G; Goldschmidt, H; Schneeweiß, A; Fersis, N; Kaul, S; Wallwiener, D; Bastert, G; Haas, R

1999-01-01

We report on the efficacy and toxicity of a sequential high-dose therapy with peripheral blood stem cell (PBSC) support in 85 patients with high-risk stage II/III breast cancer. There were 71 patients with more than nine tumour-positive axillary lymph nodes. An induction therapy of two cycles of ifosfamide (total dose, 7.5 g m−2) and epirubicin (120 mg m−2) was given, and PBSC were harvested during G-CSF-supported leucocyte recovery following the second cycle. The PBSC-supported high-dose chemotherapy consisted of two cycles of ifosfamide (total dose, 12 000 mg m−2), carboplatin (900 mg m−2) and epirubicin (180 mg m−2). Patients were autografted with a median number of 3.7 × 106 CD34+ cells kg−1 (range, 1.9–26.5 × 106) resulting in haematological reconstitution within approximately 2 weeks following high-dose therapy. The toxicity was moderate in general, and there was no treatment-related toxic death. Twenty-one patients relapsed between 3 and 30 months following the last cycle of high-dose therapy (median, 11 months). The probability of disease-free and overall survival at 4 years were 60% and 83%, respectively. According to a multivariate analysis, patients with stage II disease had a significantly better probability of disease-free survival (74%) in comparison to patients with stage III disease (36%). The probability of disease-free survival was also significantly better for patients with oestrogen receptor-positive tumours (70%) compared to patients with receptor-negative ones (40%). Bone marrow samples collected from 52 patients after high-dose therapy were examined to evaluate the prognostic relevance of isolated tumour cells. The proportion of patients presenting with tumour cell-positive samples did not change in comparison to that observed before high-dose therapy (65% vs 71%), but a decrease in the incidence and concentration of tumour cells was observed over time after high-dose therapy. This finding was true for patients with relapse and for those in remission, which argues against a prognostic significance of isolated tumour cells in bone marrow. In conclusion, sequential high-dose chemotherapy with PBSC support can be safely administered to patients with high-risk stage II/III breast cancer. Further intensification of the therapy, including the addition of non-cross resistant drugs or immunological approaches such as the use of antibodies against HER-2/NEU, may be envisaged for patients with stage III disease and hormone receptor-negative tumours. © 1999 Cancer Research Campaign PMID:10188897

Sequential Classifier Training for Rice Mapping with Multitemporal Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Guo, Y.; Jia, X.; Paull, D.

2017-10-01

Most traditional methods for rice mapping with remote sensing data are effective when they are applied to the initial growing stage of rice, as the practice of flooding during this period makes the spectral characteristics of rice fields more distinguishable. In this study, we propose a sequential classifier training approach for rice mapping that can be used over the whole growing period of rice for monitoring various growth stages. Rice fields are firstly identified during the initial flooding period. The identified rice fields are used as training data to train a classifier that separates rice and non-rice pixels. The classifier is then used as a priori knowledge to assist the training of classifiers for later rice growing stages. This approach can be applied progressively to sequential image data, with only a small amount of training samples being required from each image. In order to demonstrate the effectiveness of the proposed approach, experiments were conducted at one of the major rice-growing areas in Australia. The proposed approach was applied to a set of multitemporal remote sensing images acquired by the Sentinel-2A satellite. Experimental results show that, compared with traditional spectral-indexbased algorithms, the proposed method is able to achieve more stable and consistent rice mapping accuracies and it reaches higher than 80% during the whole rice growing period.

Educator Perspectives on the Use of Alternative Assessment Methods within Taught Masters Programmes: An Exploratory Study Using Activity Theory and Q Methodology

ERIC Educational Resources Information Center

Deignan, Tim; Brown, Sally

2016-01-01

This article reports on an exploratory two-stage sequential mixed methods research study that investigated the views of university educators on the introduction of assessment methods other than essays, exams and dissertations within taught Masters programmes. In the first stage, interviews were conducted internationally with 45 participants and…

Basis Expansion Approaches for Regularized Sequential Dictionary Learning Algorithms With Enforced Sparsity for fMRI Data Analysis.

PubMed

Seghouane, Abd-Krim; Iqbal, Asif

2017-09-01

Sequential dictionary learning algorithms have been successfully applied to functional magnetic resonance imaging (fMRI) data analysis. fMRI data sets are, however, structured data matrices with the notions of temporal smoothness in the column direction. This prior information, which can be converted into a constraint of smoothness on the learned dictionary atoms, has seldomly been included in classical dictionary learning algorithms when applied to fMRI data analysis. In this paper, we tackle this problem by proposing two new sequential dictionary learning algorithms dedicated to fMRI data analysis by accounting for this prior information. These algorithms differ from the existing ones in their dictionary update stage. The steps of this stage are derived as a variant of the power method for computing the SVD. The proposed algorithms generate regularized dictionary atoms via the solution of a left regularized rank-one matrix approximation problem where temporal smoothness is enforced via regularization through basis expansion and sparse basis expansion in the dictionary update stage. Applications on synthetic data experiments and real fMRI data sets illustrating the performance of the proposed algorithms are provided.

Analysis of creative mathematic thinking ability in problem based learning model based on self-regulation learning

NASA Astrophysics Data System (ADS)

Munahefi, D. N.; Waluya, S. B.; Rochmad

2018-03-01

The purpose of this research identified the effectiveness of Problem Based Learning (PBL) models based on Self Regulation Leaning (SRL) on the ability of mathematical creative thinking and analyzed the ability of mathematical creative thinking of high school students in solving mathematical problems. The population of this study was students of grade X SMA N 3 Klaten. The research method used in this research was sequential explanatory. Quantitative stages with simple random sampling technique, where two classes were selected randomly as experimental class was taught with the PBL model based on SRL and control class was taught with expository model. The selection of samples at the qualitative stage was non-probability sampling technique in which each selected 3 students were high, medium, and low academic levels. PBL model with SRL approach effectived to students’ mathematical creative thinking ability. The ability of mathematical creative thinking of low academic level students with PBL model approach of SRL were achieving the aspect of fluency and flexibility. Students of academic level were achieving fluency and flexibility aspects well. But the originality of students at the academic level was not yet well structured. Students of high academic level could reach the aspect of originality.

Diagnostic test accuracy and prevalence inferences based on joint and sequential testing with finite population sampling.

PubMed

Su, Chun-Lung; Gardner, Ian A; Johnson, Wesley O

2004-07-30

The two-test two-population model, originally formulated by Hui and Walter, for estimation of test accuracy and prevalence estimation assumes conditionally independent tests, constant accuracy across populations and binomial sampling. The binomial assumption is incorrect if all individuals in a population e.g. child-care centre, village in Africa, or a cattle herd are sampled or if the sample size is large relative to population size. In this paper, we develop statistical methods for evaluating diagnostic test accuracy and prevalence estimation based on finite sample data in the absence of a gold standard. Moreover, two tests are often applied simultaneously for the purpose of obtaining a 'joint' testing strategy that has either higher overall sensitivity or specificity than either of the two tests considered singly. Sequential versions of such strategies are often applied in order to reduce the cost of testing. We thus discuss joint (simultaneous and sequential) testing strategies and inference for them. Using the developed methods, we analyse two real and one simulated data sets, and we compare 'hypergeometric' and 'binomial-based' inferences. Our findings indicate that the posterior standard deviations for prevalence (but not sensitivity and specificity) based on finite population sampling tend to be smaller than their counterparts for infinite population sampling. Finally, we make recommendations about how small the sample size should be relative to the population size to warrant use of the binomial model for prevalence estimation. Copyright 2004 John Wiley & Sons, Ltd.

Mixing modes in a population-based interview survey: comparison of a sequential and a concurrent mixed-mode design for public health research.

PubMed

Mauz, Elvira; von der Lippe, Elena; Allen, Jennifer; Schilling, Ralph; Müters, Stephan; Hoebel, Jens; Schmich, Patrick; Wetzstein, Matthias; Kamtsiuris, Panagiotis; Lange, Cornelia

2018-01-01

Population-based surveys currently face the problem of decreasing response rates. Mixed-mode designs are now being implemented more often to account for this, to improve sample composition and to reduce overall costs. This study examines whether a concurrent or sequential mixed-mode design achieves better results on a number of indicators of survey quality. Data were obtained from a population-based health interview survey of adults in Germany that was conducted as a methodological pilot study as part of the German Health Update (GEDA). Participants were randomly allocated to one of two surveys; each of the surveys had a different design. In the concurrent mixed-mode design ( n  = 617) two types of self-administered questionnaires (SAQ-Web and SAQ-Paper) and computer-assisted telephone interviewing were offered simultaneously to the respondents along with the invitation to participate. In the sequential mixed-mode design ( n  = 561), SAQ-Web was initially provided, followed by SAQ-Paper, with an option for a telephone interview being sent out together with the reminders at a later date. Finally, this study compared the response rates, sample composition, health indicators, item non-response, the scope of fieldwork and the costs of both designs. No systematic differences were identified between the two mixed-mode designs in terms of response rates, the socio-demographic characteristics of the achieved samples, or the prevalence rates of the health indicators under study. The sequential design gained a higher rate of online respondents. Very few telephone interviews were conducted for either design. With regard to data quality, the sequential design (which had more online respondents) showed less item non-response. There were minor differences between the designs in terms of their costs. Postage and printing costs were lower in the concurrent design, but labour costs were lower in the sequential design. No differences in health indicators were found between the two designs. Modelling these results for higher response rates and larger net sample sizes indicated that the sequential design was more cost and time-effective. This study contributes to the research available on implementing mixed-mode designs as part of public health surveys. Our findings show that SAQ-Paper and SAQ-Web questionnaires can be combined effectively. Sequential mixed-mode designs with higher rates of online respondents may be of greater benefit to studies with larger net sample sizes than concurrent mixed-mode designs.

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.

X-ray tomographic image magnification process, system and apparatus therefor

DOEpatents

Kinney, J.H.; Bonse, U.K.; Johnson, Q.C.; Nichols, M.C.; Saroyan, R.A.; Massey, W.N.; Nusshardt, R.

1993-09-14

A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising: (a) source means for providing a source of parallel x-ray beams, (b) staging means for staging and sequentially rotating a sample to be positioned in the path of the (c) x-ray image magnifier means positioned in the path of the beams downstream from the sample, (d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means, and (e) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor. 25 figures.

X-ray tomographic image magnification process, system and apparatus therefor

DOEpatents

Kinney, John H.; Bonse, Ulrich K.; Johnson, Quintin C.; Nichols, Monte C.; Saroyan, Ralph A.; Massey, Warren N.; Nusshardt, Rudolph

1993-01-01

A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising: a) source means for providing a source of parallel x-ray beams, b) staging means for staging and sequentially rotating a sample to be positioned in the path of the c) x-ray image magnifier means positioned in the path of the beams downstream from the sample, d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means, and e) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor.

Regional trends in the fractional solubility of Fe and other metals from North Atlantic aerosols (GEOTRACES cruises GA01 and GA03) following a two-stage leach

NASA Astrophysics Data System (ADS)

Shelley, Rachel U.; Landing, William M.; Ussher, Simon J.; Planquette, Helene; Sarthou, Geraldine

2018-04-01

The fractional solubility of aerosol-derived trace elements deposited to the ocean surface is a key parameter of many marine biogeochemical models. Despite this, it is currently poorly constrained, in part due to the complex interplay between the various processes that govern the solubilisation of aerosol trace elements. In this study, we used a sequential two-stage leach to investigate the regional variability in fractional solubility of a suite of aerosol trace elements (Al, Ti, Fe, Mn, Co, Ni, Cu, Zn, Cd, and Pb) from samples collected during three GEOTRACES cruises to the North Atlantic Ocean (GA01, GA03-2010, and GA03-2011). We present aerosol trace element solubility data from two sequential leaches that provide a solubility window, covering a conservative lower limit to an upper limit, the maximum potentially soluble fraction, and discuss why this upper limit of solubility could be used as a proxy for the bioavailable fraction in some regions. Regardless of the leaching solution used in this study (mild versus strong leach), the most heavily loaded samples generally had the lowest solubility. However, there were exceptions. Manganese fractional solubility was relatively uniform across the full range of atmospheric loading (32 ± 13 and 49 ± 13 % for ultra high-purity water and 25 % acetic acid leaches, respectively). This is consistent with other marine aerosol studies. Zinc and Cd fractional solubility also appeared to be independent of atmospheric loading. Although the average fractional solubilities of Zn and Cd (37 ± 28 and 55 ± 30 % for Zn and 39 ± 23 and 58 ± 26 % for Cd, for ultra high-purity water and 25 % acetic acid leaches, respectively) were similar to Mn, the range was greater, with several samples being 100 % soluble after the second leach. Finally, as the objective of this study was to investigate the regional variability in TE solubility, the samples were grouped according to air mass back trajectories (AMBTs). However, we conclude that AMBTs are not sufficiently discriminating to identify the aerosol sources or the potential effects of atmospheric processing on the physicochemical composition and solubility of the aerosols.

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.

Unipedal Diagnostic Lymphangiography Followed by Sequential CT Examinations in Patients With Idiopathic Chyluria: A Retrospective Study.

PubMed

Dong, Jian; Xin, Jianfeng; Shen, Wenbin; Chen, Xiaobai; Wen, Tingguo; Zhang, Chunyan; Wang, Rengui

2018-04-01

The objective of our study was to investigate the clinical value of diagnostic lymphangiography followed by sequential CT examinations in patients with idiopathic chyluria. Thirty-six patients with idiopathic chyluria underwent unipedal diagnostic lymphangiography and then underwent sequential CT examinations. The examinations were reviewed separately by two radiologists. Abnormal distribution of contrast medium, lymphourinary leakages, and retrograde flow were noted, and the range and distribution of lymphatic vessel lesions were recorded. The stage of idiopathic chyluria based on CT findings and the stage based on clinical findings were compared. Therapeutic management and follow-up were recorded. Statistical analyses were performed. Compared with CT studies performed after lymphangiography, diagnostic lymphangiography showed a unique capability to depict lymphourinary leakages in three patients. Lymphourinary fistulas and abnormal dilated lymphatic vessels were found in and around kidney in all patients. CT depicted retrograde flow of lymph fluid in 47.2% of patients. The consistency in staging chyluria based on CT findings and clinical findings was fair (κ = 0.455). Twenty-nine patients underwent conservative therapy, and seven underwent surgery. Surgical therapy was superior to conservative management (no recurrence, 85.7% of patients who underwent surgery vs 62.1% of patients who underwent conservative therapy; p = 0.025). From assessing the drainage of contrast medium on unipedal diagnostic lymphangiography and the redistribution of contrast medium on sequential CT examinations, it is possible to detect the existence of lymphourinary fistulas, the precise location of lymphatic anomalies, the distribution of collateral lymphatic vessels, and hydrodynamic pressure abnormality in the lymph circulation in patients with idiopathic chyluria. CT staging of chyluria provides additional information that can be used to guide therapeutic management.

Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

PubMed

NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

2017-08-01

Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

Fixed-Precision Sequential Sampling Plans for Estimating Alfalfa Caterpillar, Colias lesbia, Egg Density in Alfalfa, Medicago sativa, Fields in Córdoba, Argentina

PubMed Central

Serra, Gerardo V.; Porta, Norma C. La; Avalos, Susana; Mazzuferi, Vilma

2013-01-01

The alfalfa caterpillar, Colias lesbia (Fabricius) (Lepidoptera: Pieridae), is a major pest of alfalfa, Medicago sativa L. (Fabales: Fabaceae), crops in Argentina. Its management is based mainly on chemical control of larvae whenever the larvae exceed the action threshold. To develop and validate fixed-precision sequential sampling plans, an intensive sampling programme for C. lesbia eggs was carried out in two alfalfa plots located in the Province of Córdoba, Argentina, from 1999 to 2002. Using Resampling for Validation of Sampling Plans software, 12 additional independent data sets were used to validate the sequential sampling plan with precision levels of 0.10 and 0.25 (SE/mean), respectively. For a range of mean densities of 0.10 to 8.35 eggs/sample, an average sample size of only 27 and 26 sample units was required to achieve a desired precision level of 0.25 for the sampling plans of Green and Kuno, respectively. As the precision level was increased to 0.10, average sample size increased to 161 and 157 sample units for the sampling plans of Green and Kuno, respectively. We recommend using Green's sequential sampling plan because it is less sensitive to changes in egg density. These sampling plans are a valuable tool for researchers to study population dynamics and to evaluate integrated pest management strategies. PMID:23909840

A Fixed-Precision Sequential Sampling Plan for the Potato Tuberworm Moth, Phthorimaea operculella Zeller (Lepidoptera: Gelechidae), on Potato Cultivars.

PubMed

Shahbi, M; Rajabpour, A

2017-08-01

Phthorimaea operculella Zeller is an important pest of potato in Iran. Spatial distribution and fixed-precision sequential sampling for population estimation of the pest on two potato cultivars, Arinda ® and Sante ® , were studied in two separate potato fields during two growing seasons (2013-2014 and 2014-2015). Spatial distribution was investigated by Taylor's power law and Iwao's patchiness. Results showed that the spatial distribution of eggs and larvae was random. In contrast to Iwao's patchiness, Taylor's power law provided a highly significant relationship between variance and mean density. Therefore, fixed-precision sequential sampling plan was developed by Green's model at two precision levels of 0.25 and 0.1. The optimum sample size on Arinda ® and Sante ® cultivars at precision level of 0.25 ranged from 151 to 813 and 149 to 802 leaves, respectively. At 0.1 precision level, the sample sizes varied from 5083 to 1054 and 5100 to 1050 leaves for Arinda ® and Sante ® cultivars, respectively. Therefore, the optimum sample sizes for the cultivars, with different resistance levels, were not significantly different. According to the calculated stop lines, the sampling must be continued until cumulative number of eggs + larvae reached to 15-16 or 96-101 individuals at precision levels of 0.25 or 0.1, respectively. The performance of the sampling plan was validated by resampling analysis using resampling for validation of sampling plans software. The sampling plant provided in this study can be used to obtain a rapid estimate of the pest density with minimal effort.

Determination of the Pb, Cr, and Cd distribution patterns with various chlorine additives in the bottom ashes of a low-temperature two-stage fluidized bed incinerator by chemical sequential extraction.

PubMed

Peng, Tzu-Huan; Lin, Chiou-Liang; Wey, Ming-Yen

2015-09-15

A novel low-temperature two-stage fluidized bed (LTTSFB) incinerator has been successfully developed to control heavy-metal emissions during municipal solid waste (MSW) treatment. However, the characteristics of the residual metal patterns during this process are still unclear. The aim of this study was to investigate the metal patterns in the different partitions of the LTTSFB bottom ash by chemical sequential extraction. Artificial waste was used to simulate the MSW. Different parameters including the first-stage temperature, chloride additives, and operating gas velocity were also considered. Results indicated that during the low-temperature treatment process, a high metal mobility phase exists in the first-stage sand bed. The main patterns of Cd, Pb, and Cr observed were the water-soluble, exchangeable, and residual forms, respectively. With the different Cl additives, the results showed that polyvinyl chloride addition increased metal mobility in the LTTSFB bottom ash, while, sodium chloride addition may have reduced metal mobility due to the formation of eutectic material. The second-stage sand bed was found to have a lower risk of metal leaching. The results also suggested that, the residual ashes produced by the LTTSFB system must be taken into consideration given their high metal mobility. Copyright © 2015 Elsevier B.V. All rights reserved.

Progressive Sampling Technique for Efficient and Robust Uncertainty and Sensitivity Analysis of Environmental Systems Models: Stability and Convergence

NASA Astrophysics Data System (ADS)

Sheikholeslami, R.; Hosseini, N.; Razavi, S.

2016-12-01

Modern earth and environmental models are usually characterized by a large parameter space and high computational cost. These two features prevent effective implementation of sampling-based analysis such as sensitivity and uncertainty analysis, which require running these computationally expensive models several times to adequately explore the parameter/problem space. Therefore, developing efficient sampling techniques that scale with the size of the problem, computational budget, and users' needs is essential. In this presentation, we propose an efficient sequential sampling strategy, called Progressive Latin Hypercube Sampling (PLHS), which provides an increasingly improved coverage of the parameter space, while satisfying pre-defined requirements. The original Latin hypercube sampling (LHS) approach generates the entire sample set in one stage; on the contrary, PLHS generates a series of smaller sub-sets (also called `slices') while: (1) each sub-set is Latin hypercube and achieves maximum stratification in any one dimensional projection; (2) the progressive addition of sub-sets remains Latin hypercube; and thus (3) the entire sample set is Latin hypercube. Therefore, it has the capability to preserve the intended sampling properties throughout the sampling procedure. PLHS is deemed advantageous over the existing methods, particularly because it nearly avoids over- or under-sampling. Through different case studies, we show that PHLS has multiple advantages over the one-stage sampling approaches, including improved convergence and stability of the analysis results with fewer model runs. In addition, PLHS can help to minimize the total simulation time by only running the simulations necessary to achieve the desired level of quality (e.g., accuracy, and convergence rate).

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

PubMed

van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

2002-09-01

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method.

Characterization of alkyl carbon in forest soils by CPMAS 13C NMR spectroscopy and dipolar dephasing

USGS Publications Warehouse

Kogel-Knabner, I.; Hatcher, P.G.

1989-01-01

Samples obtained from forest soils at different stages of decomposition were treated sequentially with chloroform/methanol (extraction of lipids), sulfuric acid (hydrolysis), and sodium chlorite (delignification) to enrich them in refractory alkyl carbon. As revealed by NMR spectroscopy, this treatment yielded residues with high contents of alkyl carbon. In the NMR spectra of residues obtained from litter samples, resonances for carbohydrates are also present, indicating that these carbohydrates are tightly bound to the alkyl carbon structures. During decomposition in the soils this resistant carbohydrate fraction is lost almost completely. In the litter samples the alkyl carbon shows a dipolar dephasing behavior indicative of two structural components, a rigid and a more mobile component. As depth and decomposition increase, only the rigid component is observed. This fact could be due to selective degradation of the mobile component or to changes in molecular mobility during decomposition, e.g., because of an increase in cross linking or contact with the mineral matter of the soil.

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…

Sequential Sampling Plan of Anthonomus grandis (Coleoptera: Curculionidae) in Cotton Plants.

PubMed

Grigolli, J F J; Souza, L A; Mota, T A; Fernandes, M G; Busoli, A C

2017-04-01

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is one of the most important pests of cotton production worldwide. The objective of this work was to develop a sequential sampling plan for the boll weevil. The studies were conducted in Maracaju, MS, Brazil, in two seasons with cotton cultivar FM 993. A 10,000-m2 area of cotton was subdivided into 100 of 10- by 10-m plots, and five plants per plot were evaluated weekly, recording the number of squares with feeding + oviposition punctures of A. grandis in each plant. A sequential sampling plan by the maximum likelihood ratio test was developed, using a 10% threshold level of squares attacked. A 5% security level was adopted for the elaboration of the sequential sampling plan. The type I and type II error used was 0.05, recommended for studies with insects. The adjustment of the frequency distributions used were divided into two phases, so that the model that best fit to the data was the negative binomial distribution up to 85 DAE (Phase I), and from there the best fit was Poisson distribution (Phase II). The equations that define the decision-making for Phase I are S0 = -5.1743 + 0.5730N and S1 = 5.1743 + 0.5730N, and for the Phase II are S0 = -4.2479 + 0.5771N and S1 = 4.2479 + 0.5771N. The sequential sampling plan developed indicated the maximum number of sample units expected for decision-making is ∼39 and 31 samples for Phases I and II, respectively. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Interim analyses in 2 x 2 crossover trials.

PubMed

Cook, R J

1995-09-01

A method is presented for performing interim analyses in long term 2 x 2 crossover trials with serial patient entry. The analyses are based on a linear statistic that combines data from individuals observed for one treatment period with data from individuals observed for both periods. The coefficients in this linear combination can be chosen quite arbitrarily, but we focus on variance-based weights to maximize power for tests regarding direct treatment effects. The type I error rate of this procedure is controlled by utilizing the joint distribution of the linear statistics over analysis stages. Methods for performing power and sample size calculations are indicated. A two-stage sequential design involving simultaneous patient entry and a single between-period interim analysis is considered in detail. The power and average number of measurements required for this design are compared to those of the usual crossover trial. The results indicate that, while there is minimal loss in power relative to the usual crossover design in the absence of differential carry-over effects, the proposed design can have substantially greater power when differential carry-over effects are present. The two-stage crossover design can also lead to more economical studies in terms of the expected number of measurements required, due to the potential for early stopping. Attention is directed toward normally distributed responses.

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.

An Overview of Markov Chain Methods for the Study of Stage-Sequential Developmental Processes

ERIC Educational Resources Information Center

Kapland, David

2008-01-01

This article presents an overview of quantitative methodologies for the study of stage-sequential development based on extensions of Markov chain modeling. Four methods are presented that exemplify the flexibility of this approach: the manifest Markov model, the latent Markov model, latent transition analysis, and the mixture latent Markov model.…

A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

NASA Astrophysics Data System (ADS)

Hoseinzade, Zohre; Mokhtari, Ahmad Reza

2017-10-01

Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

Raman Spectroscopy of Experimental Oral Carcinogenesis: Study on Sequential Cancer Progression in Hamster Buccal Pouch Model.

PubMed

Kumar, Piyush; Bhattacharjee, Tanmoy; Ingle, Arvind; Maru, Girish; Krishna, C Murali

2016-10-01

Oral cancers suffer from poor 5-year survival rates, owing to late detection of the disease. Current diagnostic/screening tools need to be upgraded in view of disadvantages like invasiveness, tedious sample preparation, long output times, and interobserver variances. Raman spectroscopy has been shown to identify many disease conditions, including oral cancers, from healthy conditions. Further studies in exploring sequential changes in oral carcinogenesis are warranted. In this Raman spectroscopy study, sequential progression in experimental oral carcinogenesis in Hamster buccal pouch model was investigated using 3 approaches-ex vivo, in vivo sequential, and in vivo follow-up. In all these studies, spectral changes show lipid dominance in early stages while later stages and tumors showed increased protein to lipid ratio and nucleic acids. On similar lines, early weeks of 7,12-dimethylbenz(a)anthracene-treated and control groups showed higher overlap and low classification. The classification efficiency increased progressively, reached a plateau phase and subsequently increased up to 100% by 14 weeks. The misclassifications between treated and control spectra suggested some changes in controls as well, which was confirmed by a careful reexamination of histopathological slides. These findings suggests Raman spectroscopy may be able to identify microheterogeneity, which may often go unnoticed in conventional biochemistry wherein tissue extracts are employed, as well as in histopathology. In vivo findings, quite comparable to gold-standard supported ex vivo findings, give further proof of Raman spectroscopy being a promising label-free, noninvasive diagnostic adjunct for future clinical applications. © The Author(s) 2015.

Forging Professional Learning Communities: The Role of External Agency

ERIC Educational Resources Information Center

Sperandio, Jill; Kong, Peggy A.

2018-01-01

This article explored the effects of external agency on the establishment of professional learning communities (PLCs). The research was undertaken in the context of schools that have chosen to adopt the Primary Years Programme (PYP) of the International Baccalaureate (IB) worldwide. The study employed a two-stage qualitative sequential design…

READINESS AND READING FOR THE RETARDED CHILD.

ERIC Educational Resources Information Center

BERNSTEIN, BEBE

THIS TEACHER'S BOOK AND MANUAL, DESIGNED TO ACCOMPANY TWO WORKBOOKS, PRESENTS A FUNCTIONAL APPROACH TO READINESS AND READING FOR YOUNG EDUCABLE RETARDED CHILDREN. THE WORKBOOKS THEMSELVES OFFER PREPARATORY ACTIVITIES FOR CHILDREN AT THE READINESS LEVEL AND SEQUENTIAL ACTIVITIES AND MATERIALS FOR THOSE AT THE BEGINNING READING STAGE. THE TEACHER'S…

New image compression scheme for digital angiocardiography application

NASA Astrophysics Data System (ADS)

Anastassopoulos, George C.; Lymberopoulos, Dimitris C.; Kotsopoulos, Stavros A.; Kokkinakis, George C.

1993-06-01

The present paper deals with the development and evaluation of a new compression scheme, for angiocardiography images. This scheme provides considerable compression of the medical data file, through two different stages. The first stage obliterates the redundancy inside a single frame domain since the second stage obliterates the redundancy among the sequential frames. Within these stages the employed data compression ratio can be easily adjusted according to the needs of the angiocardiography applications, where still or moving (in slow or full motion) images are hauled. The developed scheme has been tailored on the real needs of the diagnosis oriented conferencing-teleworking processes, where Unified Image Viewing facilities are required.

Sequential versus "sandwich" sequencing of adjuvant chemoradiation for the treatment of stage III uterine endometrioid adenocarcinoma.

PubMed

Lu, Sharon M; Chang-Halpenny, Christine; Hwang-Graziano, Julie

2015-04-01

To compare the efficacy and tolerance of adjuvant chemotherapy and radiotherapy delivered in sequential (chemotherapy followed by radiation) versus "sandwich" fashion (chemotherapy, interval radiation, and remaining chemotherapy) after surgery in patients with FIGO stage III uterine endometrioid adenocarcinoma. From 2004 to 2011, we identified 51 patients treated at our institution fitting the above criteria. All patients received surgical staging followed by adjuvant chemoradiation (external-beam radiation therapy (EBRT) with or without high-dose rate (HDR) vaginal brachytherapy (VB)). Of these, 73% and 27% of patients received their adjuvant therapy in sequential and sandwich fashion, respectively. There were no significant differences in clinical or pathologic factors between patients treated with either regimen. Thirty-nine (76%) patients had stage IIIC disease. The majority of patients received 6 cycles of paclitaxel with carboplatin or cisplatin. Median EBRT dose was 45 Gy and 54% of patients received HDR VB boost (median dose 21 Gy). There were no significant differences in the estimated 5-year overall survival, local progression-free survival, and distant metastasis-free survival between the sequential and sandwich groups: 87% vs. 77% (p=0.37), 89% vs. 100% (p=0.21), and 78% vs. 85% (p=0.79), respectively. No grade 3-4 genitourinary or gastrointestinal toxicities were reported in either group. There was a trend towards higher incidence of grade 3-4 hematologic toxicity in the sandwich group. Adjuvant chemoradiation for FIGO stage III endometrioid uterine cancer given in either sequential or sandwich fashion appears to offer equally excellent early clinical outcomes and acceptably low toxicity. Copyright © 2015 Elsevier Inc. All rights reserved.

A Nonrandomized, Phase II Study of Sequential Irinotecan and Flavopiridol in Patients With Advanced Hepatocellular Carcinoma

PubMed Central

Ang, Celina; O'Reilly, Eileen M.; Carvajal, Richard D.; Capanu, Marinela; Gonen, Mithat; Doyle, Laurence; Ghossein, Ronald; Schwartz, Lawrence; Jacobs, Gria; Ma, Jennifer; Schwartz, Gary K.

2012-01-01

ABSTRACT BACKGROUND: Flavopiridol, a Cdk inhibitor, potentiates irinotecan-induced apoptosis. In a phase I trial of sequential irinotecan and flavopiridol, 2 patients with advanced hepatocellular carcinoma (HCC) had stable disease (SD) for ≥14 months. We thus studied the sequential combination of irinotecan and flavopiridol in patients with HCC. METHODS: Patients with advanced HCC naïve to systemic therapy, Child-Pugh ≤B8, and Karnofsky performance score (KPS) ≥70% received 100 mg/m2 irinotecan followed 7 hours later by flavopiridol 60 mg/m2 weekly for 4 of 6 weeks. The primary end point was an improvement in progression-free survival at 4 months (PFS-4) from 33% to 54%, using a Simon's two-stage design. Tumors were stained for p53. RESULTS: Only 16 patients in the first stage were enrolled: median age, 64 years; median KPS, 80%; Child-Pugh A, 87.5%; and stage III/IV, 25%/75%. The primary end point was not met; PFS-4 was 20%, leading to early termination of the study. Ten patients were evaluable for response: 1 had SD >1 year and 9 had disease progression. Grade 3 fatigue, dehydration, diarrhea, neutropenia with or without fever, lymphopenia, anemia, hyperbilirubinemia, and transaminitis occurred in ≥10% of the patients. Of the 9 patients who progressed, 5 had mutant p53 and 4 had wild-type p53. The patient with stable disease had wild-type p53. CONCLUSION: Sequential irinotecan and flavopiridol are ineffective and poorly tolerated in patients with advanced HCC. Despite our limited assessments, it is possible that the presence of wild-type p53 is necessary but not sufficient to predict response in HCC. PMID:23293699

Sequential parallel comparison design with binary and time-to-event outcomes.

PubMed

Silverman, Rachel Kloss; Ivanova, Anastasia; Fine, Jason

2018-04-30

Sequential parallel comparison design (SPCD) has been proposed to increase the likelihood of success of clinical trials especially trials with possibly high placebo effect. Sequential parallel comparison design is conducted with 2 stages. Participants are randomized between active therapy and placebo in stage 1. Then, stage 1 placebo nonresponders are rerandomized between active therapy and placebo. Data from the 2 stages are pooled to yield a single P value. We consider SPCD with binary and with time-to-event outcomes. For time-to-event outcomes, response is defined as a favorable event prior to the end of follow-up for a given stage of SPCD. We show that for these cases, the usual test statistics from stages 1 and 2 are asymptotically normal and uncorrelated under the null hypothesis, leading to a straightforward combined testing procedure. In addition, we show that the estimators of the treatment effects from the 2 stages are asymptotically normal and uncorrelated under the null and alternative hypothesis, yielding confidence interval procedures with correct coverage. Simulations and real data analysis demonstrate the utility of the binary and time-to-event SPCD. Copyright © 2018 John Wiley & Sons, Ltd.

Sequential inflammatory processes define human progression from M. tuberculosis infection to tuberculosis disease.

PubMed

Scriba, Thomas J; Penn-Nicholson, Adam; Shankar, Smitha; Hraha, Tom; Thompson, Ethan G; Sterling, David; Nemes, Elisa; Darboe, Fatoumatta; Suliman, Sara; Amon, Lynn M; Mahomed, Hassan; Erasmus, Mzwandile; Whatney, Wendy; Johnson, John L; Boom, W Henry; Hatherill, Mark; Valvo, Joe; De Groote, Mary Ann; Ochsner, Urs A; Aderem, Alan; Hanekom, Willem A; Zak, Daniel E

2017-11-01

Our understanding of mechanisms underlying progression from Mycobacterium tuberculosis infection to pulmonary tuberculosis disease in humans remains limited. To define such mechanisms, we followed M. tuberculosis-infected adolescents longitudinally. Blood samples from forty-four adolescents who ultimately developed tuberculosis disease (“progressors”) were compared with those from 106 matched controls, who remained healthy during two years of follow up. We performed longitudinal whole blood transcriptomic analyses by RNA sequencing and plasma proteome analyses using multiplexed slow off-rate modified DNA aptamers. Tuberculosis progression was associated with sequential modulation of immunological processes. Type I/II interferon signalling and complement cascade were elevated 18 months before tuberculosis disease diagnosis, while changes in myeloid inflammation, lymphoid, monocyte and neutrophil gene modules occurred more proximally to tuberculosis disease. Analysis of gene expression in purified T cells also revealed early suppression of Th17 responses in progressors, relative to M. tuberculosis-infected controls. This was confirmed in an independent adult cohort who received BCG re-vaccination; transcript expression of interferon response genes in blood prior to BCG administration was associated with suppression of IL-17 expression by BCG-specific CD4 T cells 3 weeks post-vaccination. Our findings provide a timeline to the different immunological stages of disease progression which comprise sequential inflammatory dynamics and immune alterations that precede disease manifestations and diagnosis of tuberculosis disease. These findings have important implications for developing diagnostics, vaccination and host-directed therapies for tuberculosis. Clincialtrials.gov, NCT01119521.

The effects of sequential use of oxytocin and sublingual nitroglycerin in the cases of retained placenta.

PubMed

Kashanian, Maryam; Hasankhani, Samira; Sheikhansari, Narges; Bahasadri, Shohreh; Homam, Homa

2016-10-01

To evaluate the effects of adding sublingual nitroglycerin to oxytocin, for delivery of retained placenta after vaginal delivery. The study was performed as a placebo controlled clinical trial on women who did not finish delivering placenta after 30 min of active management of the third stage of labor. In case group, 1 mg nitroglycerin and in the control group, placebo was prescribed sublingually. In total, 80 women finished the study. The number of manual removal of placenta did not show significant difference between the two groups [25 women (62.5%) in the case and 30 women (75%) in the control group, p = 0.335]. There was no significant difference between the two groups according to duration of the third stage of labor, hemoglobin index, decline in HB index >30% and maternal vital signs after treatment. There was no significant difference between the two groups according to adverse effects [eight women (20%) in the case group and four (10%) in the control group (p = 0.348)]. The sequential use of oxytocin and sublingual nitroglycerin could not lead to delivery of more placentas and did not reduce the necessity of manual removal of placenta in comparison with placebo.

The Place of Technology Integration in Saudi Pre-Service Teacher Education: Matching Policy with Practice

ERIC Educational Resources Information Center

Al-Zahrani, Abdulrahman

2015-01-01

The current study aims at understanding the place of technology integration in Saudi pre-service teacher education curriculum. To achieve this, a sequential qualitative approach was implemented in two main stages. First, national and curriculum policies were thematically analysed. Based on this, semi- structured interviews with three key…

Being "SMART" About Adolescent Conduct Problems Prevention: Executing a SMART Pilot Study in a Juvenile Diversion Agency.

PubMed

August, Gerald J; Piehler, Timothy F; Bloomquist, Michael L

2016-01-01

The development of adaptive treatment strategies (ATS) represents the next step in innovating conduct problems prevention programs within a juvenile diversion context. Toward this goal, we present the theoretical rationale, associated methods, and anticipated challenges for a feasibility pilot study in preparation for implementing a full-scale SMART (i.e., sequential, multiple assignment, randomized trial) for conduct problems prevention. The role of a SMART design in constructing ATS is presented. The SMART feasibility pilot study includes a sample of 100 youth (13-17 years of age) identified by law enforcement as early stage offenders and referred for precourt juvenile diversion programming. Prior data on the sample population detail a high level of ethnic diversity and approximately equal representations of both genders. Within the SMART, youth and their families are first randomly assigned to one of two different brief-type evidence-based prevention programs, featuring parent-focused behavioral management or youth-focused strengths-building components. Youth who do not respond sufficiently to brief first-stage programming will be randomly assigned a second time to either an extended parent- or youth-focused second-stage programming. Measures of proximal intervention response and measures of potential candidate tailoring variables for developing ATS within this sample are detailed. Results of the described pilot study will include information regarding feasibility and acceptability of the SMART design. This information will be used to refine a subsequent full-scale SMART. The use of a SMART to develop ATS for prevention will increase the efficiency and effectiveness of prevention programing for youth with developing conduct problems.

Gear tooth stress measurements of two helicopter planetary stages

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.

1992-01-01

Two versions of the planetary reduction stages from U.S. Army OH-58 helicopter main rotor transmissions were tested at NASA Lewis. One sequential and one nonsequential planetary were tested. Sun gear and ring gear teeth strains were measured, and stresses were calculated from the strains. The alternating stress at the fillet of both the loaded and unloaded sides of the teeth and at the root of the sun gear teeth are reported. Typical stress variations as the gear tooth moves through mesh are illustrated. At the tooth root location of the thin rimmed sun gear, a significant stress was produced by a phenomenon other than the passing of a planet gear. The load variation among the planets was studied. Each planet produced its own distinctive load distribution on the ring and sun gears. The load variation was less for a three planet, nonsequential design as compared to that of a four planet, sequential design. The reported results enhance the data base for gear stress levels and provide data for the validation of analytical methods.

Performance review using sequential sampling and a practice computer.

PubMed

Difford, F

1988-06-01

The use of sequential sample analysis for repeated performance review is described with examples from several areas of practice. The value of a practice computer in providing a random sample from a complete population, evaluating the parameters of a sequential procedure, and producing a structured worksheet is discussed. It is suggested that sequential analysis has advantages over conventional sampling in the area of performance review in general practice.

Comparison of human embryomorphokinetic parameters in sequential or global culture media.

PubMed

Kazdar, Nadia; Brugnon, Florence; Bouche, Cyril; Jouve, Guilhem; Veau, Ségolène; Drapier, Hortense; Rousseau, Chloé; Pimentel, Céline; Viard, Patricia; Belaud-Rotureau, Marc-Antoine; Ravel, Célia

2017-08-01

A prospective study on randomized patients was conducted to determine how morphokinetic parameters are altered in embryos grown in sequential versus global culture media. Eleven morphokinetic parameters of 160 single embryos transferred were analyzed by time lapse imaging involving two University-affiliated in vitro fertilization (IVF) centers. We found that the fading of the two pronuclei occurred earlier in global (22.56±2.15 hpi) versus sequential media (23.63±2.71 hpi; p=0.0297). Likewise, the first cleavage started earlier at 24.52±2.33 hpi vs 25.76±2.95 hpi (p=0.0158). Also, the first cytokinesis was shorter in global medium, lasting 18±10.2 minutes in global versus 36±37.8 minutes in sequential culture medium (p <0.0001). We also observed a significant shortening in the duration of the 2-cell stage in sequential medium: 10.64 h±2.75 versus 11.66 h±1.11 in global medium (p=0.0225) which suggested a faster progression of the embryos through their first mitotic cell cycle. In conclusion, morphokinetic analysis of human embryos by Time lapse imaging reveals significant differences in five kinetic variables according to culture medium. Our study highlights the need to adapt morphokinetic analysis accordingly to the type of media used to best support human early embryo development.

Sequential ensemble-based optimal design for parameter estimation: SEQUENTIAL ENSEMBLE-BASED OPTIMAL DESIGN

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

Man, Jun; Zhang, Jiangjiang; Li, Weixuan

2016-10-01

The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees ofmore » freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.« less

Reproductive success of kittiwakes and murres in sequential stages of the nesting period: Relationships with diet and oceanography

NASA Astrophysics Data System (ADS)

Renner, Heather M.; Drummond, Brie A.; Benson, Anna-Marie; Paredes, Rosana

2014-11-01

Reproductive success is one of the most easily-measured and widely studied demographic parameters of colonial nesting seabirds. Nevertheless, factors affecting the sequential stages (egg laying, incubation, chick-rearing) of reproductive success are less understood. We investigated the separate sequential stages of reproductive success in piscivorous black-legged kittiwakes (Rissa tridactyla) and thick-billed murres (Uria lomvia) using a 36-year dataset (1975-2010) on the major Pribilof Islands (St. Paul and St. George), which have recently had contrasting population trajectories. Our objectives were to evaluate how the proportion of successful nests varied among stages, and to quantify factors influencing the probability of nest success at each stage in each island. We modeled the probability of nest success at each stage using General Linear Mixed Models incorporating broad-scale and local climate variables, and diet as covariates as well as other measures of reproduction such as timing of breeding and reproductive output in the previous year and previous stage. For both species we found: (1) Success in previous stages of the breeding cycle and success in the prior year better explained overall success than any environmental variables. Phenology was also an important predictor of laying success for kittiwakes. (2) Fledging success was lower when chick diets contained oceanic fish found farther from the colonies and small invertebrates, rather than coastal fish species. (3) Differences in reproductive variables at St. Paul and St. George islands did not correspond to population trends between the two islands. Our results highlight the potential importance of adult condition and annual survival to kittiwake and murre productivity and ultimately, populations. Adult condition carrying over from the previous year ultimately seems to drive annual breeding success in a cascade effect. Furthermore, condition and survival appear to be important contributors to population dynamics at each island. Therefore, adult condition and survival prior to breeding, and factors that influence these parameters such as foraging conditions in the non-breeding season, may be important datasets for understanding drivers of seabird demography at the Pribilof Islands.

High-Efficiency Power Module

NASA Technical Reports Server (NTRS)

Simons, Rainee N (Inventor); Wintucky, Edwin G (Inventor)

2013-01-01

One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

High-Efficiency Power Module

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

2015-01-01

One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

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).

Performance of the architect EBV antibody panel for determination of Epstein-Barr virus infection stage in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis.

PubMed

Guerrero-Ramos, Alvaro; Patel, Mauli; Kadakia, Kinjal; Haque, Tanzina

2014-06-01

The Architect EBV antibody panel is a new chemiluminescence immunoassay system used to determine the stage of Epstein-Barr virus (EBV) infection based on the detection of IgM and IgG antibodies to viral capsid antigen (VCA) and IgG antibodies against Epstein-Barr nuclear antigen 1 (EBNA-1). We evaluated its diagnostic accuracy in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis (IM) using the RecomLine EBV IgM and IgG immunoblots as the reference standard. In addition, the use of the antibody panel in a sequential testing algorithm based on initial EBNA-1 IgG analysis was assessed for cost-effectiveness. Finally, we investigated the degree of cross-reactivity of the VCA IgM marker during other primary viral infections that may present with an EBV IM-like picture. High sensitivity (98.3% [95% confidence interval {CI}, 90.7 to 99.7%]) and specificity (94.2% [95% CI, 87.9 to 97.8%]) were found after testing 162 precharacterized archived serum samples. There was perfect agreement between the use of the antibody panel in sequential and parallel testing algorithms, but substantial cost savings (23%) were obtained with the sequential strategy. A high rate of reactive VCA IgM results was found in primary cytomegalovirus (CMV) infections (60.7%). In summary, the Architect EBV antibody panel performs satisfactorily in the investigation of EBV IM in immunocompetent adolescents and young adults, and the application of an EBNA-1 IgG-based sequential testing algorithm is cost-effective in this diagnostic setting. Concomitant testing for CMV is strongly recommended to aid in the interpretation of EBV serological patterns. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Performance of the Architect EBV Antibody Panel for Determination of Epstein-Barr Virus Infection Stage in Immunocompetent Adolescents and Young Adults with Clinical Suspicion of Infectious Mononucleosis

PubMed Central

Patel, Mauli; Kadakia, Kinjal; Haque, Tanzina

2014-01-01

The Architect EBV antibody panel is a new chemiluminescence immunoassay system used to determine the stage of Epstein-Barr virus (EBV) infection based on the detection of IgM and IgG antibodies to viral capsid antigen (VCA) and IgG antibodies against Epstein-Barr nuclear antigen 1 (EBNA-1). We evaluated its diagnostic accuracy in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis (IM) using the RecomLine EBV IgM and IgG immunoblots as the reference standard. In addition, the use of the antibody panel in a sequential testing algorithm based on initial EBNA-1 IgG analysis was assessed for cost-effectiveness. Finally, we investigated the degree of cross-reactivity of the VCA IgM marker during other primary viral infections that may present with an EBV IM-like picture. High sensitivity (98.3% [95% confidence interval {CI}, 90.7 to 99.7%]) and specificity (94.2% [95% CI, 87.9 to 97.8%]) were found after testing 162 precharacterized archived serum samples. There was perfect agreement between the use of the antibody panel in sequential and parallel testing algorithms, but substantial cost savings (23%) were obtained with the sequential strategy. A high rate of reactive VCA IgM results was found in primary cytomegalovirus (CMV) infections (60.7%). In summary, the Architect EBV antibody panel performs satisfactorily in the investigation of EBV IM in immunocompetent adolescents and young adults, and the application of an EBNA-1 IgG-based sequential testing algorithm is cost-effective in this diagnostic setting. Concomitant testing for CMV is strongly recommended to aid in the interpretation of EBV serological patterns. PMID:24695777

A two-stage stochastic optimization model for scheduling electric vehicle charging loads to relieve distribution-system constraints

DOE PAGES

Wu, Fei; Sioshansi, Ramteen

2017-05-25

Electric vehicles (EVs) hold promise to improve the energy efficiency and environmental impacts of transportation. However, widespread EV use can impose significant stress on electricity-distribution systems due to their added charging loads. This paper proposes a centralized EV charging-control model, which schedules the charging of EVs that have flexibility. This flexibility stems from EVs that are parked at the charging station for a longer duration of time than is needed to fully recharge the battery. The model is formulated as a two-stage stochastic optimization problem. The model captures the use of distributed energy resources and uncertainties around EV arrival timesmore » and charging demands upon arrival, non-EV loads on the distribution system, energy prices, and availability of energy from the distributed energy resources. We use a Monte Carlo-based sample-average approximation technique and an L-shaped method to solve the resulting optimization problem efficiently. We also apply a sequential sampling technique to dynamically determine the optimal size of the randomly sampled scenario tree to give a solution with a desired quality at minimal computational cost. Here, we demonstrate the use of our model on a Central-Ohio-based case study. We show the benefits of the model in reducing charging costs, negative impacts on the distribution system, and unserved EV-charging demand compared to simpler heuristics. Lastly, we also conduct sensitivity analyses, to show how the model performs and the resulting costs and load profiles when the design of the station or EV-usage parameters are changed.« less

Anomaly Detection in Dynamic Networks

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

Turcotte, Melissa

2014-10-14

Anomaly detection in dynamic communication networks has many important security applications. These networks can be extremely large and so detecting any changes in their structure can be computationally challenging; hence, computationally fast, parallelisable methods for monitoring the network are paramount. For this reason the methods presented here use independent node and edge based models to detect locally anomalous substructures within communication networks. As a first stage, the aim is to detect changes in the data streams arising from node or edge communications. Throughout the thesis simple, conjugate Bayesian models for counting processes are used to model these data streams. Amore » second stage of analysis can then be performed on a much reduced subset of the network comprising nodes and edges which have been identified as potentially anomalous in the first stage. The first method assumes communications in a network arise from an inhomogeneous Poisson process with piecewise constant intensity. Anomaly detection is then treated as a changepoint problem on the intensities. The changepoint model is extended to incorporate seasonal behavior inherent in communication networks. This seasonal behavior is also viewed as a changepoint problem acting on a piecewise constant Poisson process. In a static time frame, inference is made on this extended model via a Gibbs sampling strategy. In a sequential time frame, where the data arrive as a stream, a novel, fast Sequential Monte Carlo (SMC) algorithm is introduced to sample from the sequence of posterior distributions of the change points over time. A second method is considered for monitoring communications in a large scale computer network. The usage patterns in these types of networks are very bursty in nature and don’t fit a Poisson process model. For tractable inference, discrete time models are considered, where the data are aggregated into discrete time periods and probability models are fitted to the communication counts. In a sequential analysis, anomalous behavior is then identified from outlying behavior with respect to the fitted predictive probability models. Seasonality is again incorporated into the model and is treated as a changepoint model on the transition probabilities of a discrete time Markov process. Second stage analytics are then developed which combine anomalous edges to identify anomalous substructures in the network.« less

Phase 2 Sequential and Concurrent Chemoradiation for Advanced Nasopharyngeal Carcinoma (NPC)

ClinicalTrials.gov

2016-12-09

Stage II Lymphoepithelioma of the Nasopharynx; Stage II Squamous Cell Carcinoma of the Nasopharynx; Stage III Lymphoepithelioma of the Nasopharynx; Stage III Squamous Cell Carcinoma of the Nasopharynx; Stage IV Lymphoepithelioma of the Nasopharynx; Stage IV Squamous Cell Carcinoma of the Nasopharynx

Sequential Combination of Electro-Fenton and Electrochemical Chlorination Processes for the Treatment of Anaerobically-Digested Food Wastewater.

PubMed

Shin, Yong-Uk; Yoo, Ha-Young; Kim, Seonghun; Chung, Kyung-Mi; Park, Yong-Gyun; Hwang, Kwang-Hyun; Hong, Seok Won; Park, Hyunwoong; Cho, Kangwoo; Lee, Jaesang

2017-09-19

A two-stage sequential electro-Fenton (E-Fenton) oxidation followed by electrochemical chlorination (EC) was demonstrated to concomitantly treat high concentrations of organic carbon and ammonium nitrogen (NH 4 + -N) in real anaerobically digested food wastewater (ADFW). The anodic Fenton process caused the rapid mineralization of phenol as a model substrate through the production of hydroxyl radical as the main oxidant. The electrochemical oxidation of NH 4 + by a dimensionally stable anode (DSA) resulted in temporal concentration profiles of combined and free chlorine species that were analogous to those during the conventional breakpoint chlorination of NH 4 + . Together with the minimal production of nitrate, this confirmed that the conversion of NH 4 + to nitrogen gas was electrochemically achievable. The monitoring of treatment performance with varying key parameters (e.g., current density, H 2 O 2 feeding rate, pH, NaCl loading, and DSA type) led to the optimization of two component systems. The comparative evaluation of two sequentially combined systems (i.e., the E-Fenton-EC system versus the EC-E-Fenton system) using the mixture of phenol and NH 4 + under the predetermined optimal conditions suggested the superiority of the E-Fenton-EC system in terms of treatment efficiency and energy consumption. Finally, the sequential E-Fenton-EC process effectively mineralized organic carbon and decomposed NH 4 + -N in the real ADFW without external supply of NaCl.

Noninferiority, randomized, controlled trial comparing embryo development using media developed for sequential or undisturbed culture in a time-lapse setup.

PubMed

Hardarson, Thorir; Bungum, Mona; Conaghan, Joe; Meintjes, Marius; Chantilis, Samuel J; Molnar, Laszlo; Gunnarsson, Kristina; Wikland, Matts

2015-12-01

To study whether a culture medium that allows undisturbed culture supports human embryo development to the blastocyst stage equivalently to a well-established sequential media. Randomized, double-blinded sibling trial. Independent in vitro fertilization (IVF) clinics. One hundred twenty-eight patients, with 1,356 zygotes randomized into two study arms. Embryos randomly allocated into two study arms to compare embryo development on a time-lapse system using a single-step medium or sequential media. Percentage of good-quality blastocysts on day 5. Percentage of day 5 good-quality blastocysts was 21.1% (standard deviation [SD] ± 21.6%) and 22.2% (SD ± 22.1%) in the single-step time-lapse medium (G-TL) and the sequential media (G-1/G-2) groups, respectively. The mean difference (-1.2; 95% CI, -6.0; 3.6) between the two media systems for the primary end point was less than the noninferiority margin of -8%. There was a statistically significantly lower number of good-quality embryos on day 3 in the G-TL group [50.7% (SD ± 30.6%) vs. 60.8% (SD ± 30.7%)]. Four out of the 11 measured morphokinetic parameters were statistically significantly different for the two media used. The mean levels of ammonium concentration in the media at the end of the culture period was statistically significantly lower in the G-TL group as compared with the G-2 group. We have shown that a single-step culture medium supports blastocyst development equivalently to established sequential media. The ammonium concentrations were lower in the single-step media, and the measured morphokinetic parameters were modified somewhat. NCT01939626. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A sequential sampling account of response bias and speed-accuracy tradeoffs in a conflict detection task.

PubMed

Vuckovic, Anita; Kwantes, Peter J; Humphreys, Michael; Neal, Andrew

2014-03-01

Signal Detection Theory (SDT; Green & Swets, 1966) is a popular tool for understanding decision making. However, it does not account for the time taken to make a decision, nor why response bias might change over time. Sequential sampling models provide a way of accounting for speed-accuracy trade-offs and response bias shifts. In this study, we test the validity of a sequential sampling model of conflict detection in a simulated air traffic control task by assessing whether two of its key parameters respond to experimental manipulations in a theoretically consistent way. Through experimental instructions, we manipulated participants' response bias and the relative speed or accuracy of their responses. The sequential sampling model was able to replicate the trends in the conflict responses as well as response time across all conditions. Consistent with our predictions, manipulating response bias was associated primarily with changes in the model's Criterion parameter, whereas manipulating speed-accuracy instructions was associated with changes in the Threshold parameter. The success of the model in replicating the human data suggests we can use the parameters of the model to gain an insight into the underlying response bias and speed-accuracy preferences common to dynamic decision-making tasks. © 2013 American Psychological Association

A sequential treatment of intermediate tropical landfill leachate using a sequencing batch reactor (SBR) and coagulation.

PubMed

Yong, Zi Jun; Bashir, Mohammed J K; Ng, Choon Aun; Sethupathi, Sumathi; Lim, Jun-Wei

2018-01-01

The increase in landfill leachate generation is due to the increase of municipal solid waste (MSW) as global development continues. Landfill leachate has constantly been the most challenging issue in MSW management as it contains high amount of organic and inorganic compounds that might cause pollution to water resources. Biologically treated landfill leachate often fails to fulfill the regulatory discharge standards. Thus, to prevent environmental pollution, many landfill leachate treatment plants involve multiple stages treatment process. The Papan Landfill in Perak, Malaysia currently has no proper leachate treatment system. In the current study, sequential treatment via sequencing batch reactor (SBR) followed by coagulation was used to treat chemical oxygen demand (COD), ammoniacal nitrogen (NH 3 -N), total suspended solids (TSS), and colour from raw landfill leachate. SBR optimum aeration rate, L/min, optimal pH and dosage (g/L) of Alum for coagulation as a post-treatment were determined. The two-step sequential treatment by SBR followed by coagulation (Alum) achieved a removal efficiency of 84.89%, 94.25%, 91.82% and 85.81% for COD, NH 3 -N, TSS and colour, respectively. Moreover, the two-stage treatment process achieved 95.0% 95.0%, 95.3%, 100.0%, 87.2%, 62.9%, 50.0%, 41.3%, 41.2, 34.8, and 22.9 removals of Cadmium, Lead, Copper, Selenium, Barium, Iron, Silver, Nickel, Zinc, Arsenic, and Manganese, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential character of low-energy ternary and quaternary nuclear fission

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

Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Bulychev, A. O.

2016-09-15

An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collectivemore » deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.« less

How Do Parents Acquire Information to Support Their Child with a Disability and Navigate Individualised Funding Schemes?

ERIC Educational Resources Information Center

Tracey, Danielle; Johnston, Christine; Papps, Fiona Ann; Mahmic, Sylvana

2018-01-01

With the international trend towards individualised funding packages that allocate funds to individuals to spend on disability support needs, the challenge of ensuring parents can readily access useful information to make decisions becomes paramount. The present research used a two stage, mixed method sequential approach (with 291 parents surveyed…

Sequential biofiltration - A novel approach for enhanced biological removal of trace organic chemicals from wastewater treatment plant effluent.

PubMed

Müller, Johann; Drewes, Jörg E; Hübner, Uwe

2017-12-15

Recent studies revealed the benefits of oligotrophic and oxic conditions for the biological removal of many trace organic chemicals (TOrCs) during soil-aquifer treatment. These findings indicate an unused tuning potential that might also be applicable in engineered biofiltration systems with drastically reduced hydraulic retention times for an enhanced mitigation of TOrCs during wastewater treatment. This study introduces the novel approach of sequential biofiltration (SBF) for the advanced treatment of secondary effluent using two granular media filters operated in series with an intermediate aeration step aiming for oxic and oligotrophic conditions in the second filter stage. Results from the experiments conducted at pilot-scale confirm a reduced substrate availability and predominantly oxic conditions in the second filter stage of the SBF setup. An increased removal of several TOrCs was observed in an SBF system as compared to a conventional single-stage biofiltration unit operated at the same overall empty bed contact time (EBCT). Short-term tests with varying EBCTs in the first filter stage revealed a high degree of system robustness of TOrC mitigation when confronted with sudden hydraulic load variations. Higher removal of several TOrCs at increased EBCTs in the second filter stage indicates that EBCT might play a crucial role for the degradation of certain compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cluster designs to assess the prevalence of acute malnutrition by lot quality assurance sampling: a validation study by computer simulation.

PubMed

Olives, Casey; Pagano, Marcello; Deitchler, Megan; Hedt, Bethany L; Egge, Kari; Valadez, Joseph J

2009-04-01

Traditional lot quality assurance sampling (LQAS) methods require simple random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67x3 (67 clusters of three observations) and a 33x6 (33 clusters of six observations) sampling scheme to assess the prevalence of global acute malnutrition (GAM). Further, we explore the use of a 67x3 sequential sampling scheme for LQAS classification of GAM prevalence. Results indicate that, for independent clusters with moderate intracluster correlation for the GAM outcome, the three sampling designs maintain approximate validity for LQAS analysis. Sequential sampling can substantially reduce the average sample size that is required for data collection. The presence of intercluster correlation can impact dramatically the classification error that is associated with LQAS analysis.

Cognitive level and health decision-making in children: A preliminary study.

PubMed

Okwumabua, J O; Okwumabua, T M; Hayes, A; Stovall, K

1994-06-01

The study examines children's stage of cognitive development in relation to their patterns of health decision-making, including their cognitive capabilities in integrating the sequential stages of the decision-making process. A sample of 81 male (N=33) and female (N=48) students were drawn from two urban public schools in West Tennessee. All participants in the study were of African-American descent. The Centers for Disease Control Decision-Making Instrument was used to assess students' decision-making as well as their understanding of the decision-making process. The children's cognitive level was determined by their performance on three Piagetian conservation tasks. Findings revealed that both the preoperational and concrete operational children performed significantly below the formal operational children in terms of total correct responses to the decision-making scenarios. Error type analyses indicated that the preoperational children made more errors involving "skipped step" than did either the concrete or formal operational children. There were no significant differences between children's level of cognitive development and any other error type. Implications for health promotion and disease prevention programs among prevention practitioners who work regularly with children are discussed.

Bacterial diversity in the active stage of a bioremediation system for mineral oil hydrocarbon-contaminated soils.

PubMed

Popp, Nicole; Schlömann, Michael; Mau, Margit

2006-11-01

Soils contaminated with mineral oil hydrocarbons are often cleaned in off-site bioremediation systems. In order to find out which bacteria are active during the degradation phase in such systems, the diversity of the active microflora in a degrading soil remediation system was investigated by small-subunit (SSU) rRNA analysis. Two sequential RNA extracts from one soil sample were generated by a procedure incorporating bead beating. Both extracts were analysed separately by generating individual SSU rDNA clone libraries from cDNA of the two extracts. The sequencing results showed moderate diversity. The two clone libraries were dominated by Gammaproteobacteria, especially Pseudomonas spp. Alphaproteobacteria and Betaproteobacteria were two other large groups in the clone libraries. Actinobacteria, Firmicutes, Bacteroidetes and Epsilonproteobacteria were detected in lower numbers. The obtained sequences were predominantly related to genera for which cultivated representatives have been described, but were often clustered together in the phylogenetic tree, and the sequences that were most similar were originally obtained from soils and not from pure cultures. Most of the dominant genera in the clone libraries, e.g. Pseudomonas, Acinetobacter, Sphingomonas, Acidovorax and Thiobacillus, had already been detected in (mineral oil hydrocarbon) contaminated environmental samples. The occurrence of the genera Zymomonas and Rhodoferax was novel in mineral oil hydrocarbon-contaminated soil.

Optoelectronic image processing for cervical cancer screening

NASA Astrophysics Data System (ADS)

Narayanswamy, Ramkumar; Sharpe, John P.; Johnson, Kristina M.

1994-05-01

Automation of the Pap-smear cervical screening method is highly desirable as it relieves tedium for the human operators, reduces cost and should increase accuracy and provide repeatability. We present here the design for a high-throughput optoelectronic system which forms the first stage of a two stage system to automate pap-smear screening. We use a mathematical morphological technique called the hit-or-miss transform to identify the suspicious areas on a pap-smear slide. This algorithm is implemented using a VanderLugt architecture and a time-sequential ANDing smart pixel array.

Number of pins in two-stage stratified sampling for estimating herbage yield

Treesearch

William G. O' Regan; C. Eugene Conrad

1975-01-01

In a two-stage stratified procedure for sampling herbage yield, plots are stratified by a pin frame in stage one, and clipped. In stage two, clippings from selected plots are sorted, dried, and weighed. Sample size and distribution of plots between the two stages are determined by equations. A way to compute the effect of number of pins on the variance of estimated...

Enzymatic treatment to improve extraction of capsaicinoids and carotenoids from chili (Capsicum annuum) fruits.

PubMed

Salgado-Roman, Manuel; Botello-Alvarez, Enrique; Rico-Martínez, Ramiro; Jiménez-Islas, Hugo; Cárdenas-Manríquez, Marcela; Navarrete-Bolaños, José Luis

2008-11-12

Enzymatic treatments using noncommercial enzymes as a means to the improve the extraction of carotenoids and capsaicinoids from chili fruits are explored in this study. The results show that it is possible to obtain chili fruit powder with a higher concentration of both capsaicinoids and carotenoids than previously reported for similar processes. Furthermore, extraction yields above 96% for carotenoids and 85% for capsaicinoids as separate fractions can be achieved using a sequential and selective two-stage extraction. Evidence is presented demonstrating that the content and extraction yield depend directly on the extent of the enzymatic hydrolysis of chili cell walls, and higher yields are obtained when the sample is completely hydrolyzed. The enzymatic treatment described here is a promising alternative to current industrial practices, and it improves the extraction of carotenoids and capsaicinoids from chili fruits.

An adaptive sampling method for variable-fidelity surrogate models using improved hierarchical kriging

NASA Astrophysics Data System (ADS)

Hu, Jiexiang; Zhou, Qi; Jiang, Ping; Shao, Xinyu; Xie, Tingli

2018-01-01

Variable-fidelity (VF) modelling methods have been widely used in complex engineering system design to mitigate the computational burden. Building a VF model generally includes two parts: design of experiments and metamodel construction. In this article, an adaptive sampling method based on improved hierarchical kriging (ASM-IHK) is proposed to refine the improved VF model. First, an improved hierarchical kriging model is developed as the metamodel, in which the low-fidelity model is varied through a polynomial response surface function to capture the characteristics of a high-fidelity model. Secondly, to reduce local approximation errors, an active learning strategy based on a sequential sampling method is introduced to make full use of the already required information on the current sampling points and to guide the sampling process of the high-fidelity model. Finally, two numerical examples and the modelling of the aerodynamic coefficient for an aircraft are provided to demonstrate the approximation capability of the proposed approach, as well as three other metamodelling methods and two sequential sampling methods. The results show that ASM-IHK provides a more accurate metamodel at the same simulation cost, which is very important in metamodel-based engineering design problems.

A Mixed Methods Investigation of Mixed Methods Sampling Designs in Social and Health Science Research

ERIC Educational Resources Information Center

Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.; Jiao, Qun G.

2007-01-01

A sequential design utilizing identical samples was used to classify mixed methods studies via a two-dimensional model, wherein sampling designs were grouped according to the time orientation of each study's components and the relationship of the qualitative and quantitative samples. A quantitative analysis of 121 studies representing nine fields…

Sequential anaerobic/aerobic digestion for enhanced sludge stabilization: comparison of the process performance for mixed and waste sludge [corrected].

PubMed

Tomei, M Concetta; Carozza, Nicola Antonello

2015-05-01

Sequential anaerobic-aerobic digestion has been demonstrated as a promising alternative for enhanced sludge stabilization. In this paper, a feasibility study of the sequential digestion applied to real waste activated sludge (WAS) and mixed sludge is presented. Process performance is evaluated in terms of total solid (TS) and volatile solid (VS) removal, biogas production, and dewaterability trend in the anaerobic and double-stage digested sludge. In the proposed digestion lay out, the aerobic stage was operated with intermittent aeration to reduce the nitrogen load recycled to the wastewater treatment plant (WWTP). Experimental results showed a very good performance of the sequential digestion process for both waste and mixed sludge, even if, given its better digestibility, higher efficiencies are observed for mixed sludge. VS removal efficiencies in the anaerobic stage were 48 and 50% for waste and mixed sludge, respectively, while a significant additional improvement of the VS removal of 25% for WAS and 45% for mixed sludge has been obtained in the aerobic stage. The post-aerobic stage, operated with intermittent aeration, was also efficient in nitrogen removal, providing a significant decrease of the nitrogen content in the supernatant: nitrification efficiencies of 90 and 97% and denitrification efficiencies of 62 and 70% have been obtained for secondary and mixed sludges, respectively. A positive effect due to the aerobic stage was also observed on the sludge dewaterability in both cases. Biogas production, expressed as Nm(3)/(kgVSdestroyed), was 0.54 for waste and 0.82 for mixed sludge and is in the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days.

Being “SMART” about Adolescent Conduct Problems Prevention: Executing a SMART Pilot Study in a Juvenile Diversion Agency

PubMed Central

August, Gerald J.; Piehler, Timothy F.; Bloomquist, Michael L.

2014-01-01

OBJECTIVE The development of adaptive treatment strategies (ATS) represents the next step in innovating conduct problems prevention programs within a juvenile diversion context. Towards this goal, we present the theoretical rationale, associated methods, and anticipated challenges for a feasibility pilot study in preparation for implementing a full-scale SMART (i.e., sequential, multiple assignment, randomized trial) for conduct problems prevention. The role of a SMART design in constructing ATS is presented. METHOD The SMART feasibility pilot study includes a sample of 100 youth (13–17 years of age) identified by law enforcement as early stage offenders and referred for pre-court juvenile diversion programming. Prior data on the sample population detail a high level of ethnic diversity and approximately equal representations of both genders. Within the SMART, youth and their families are first randomly assigned to one of two different brief-type evidence-based prevention programs, featuring parent-focused behavioral management or youth-focused strengths-building components. Youth who do not respond sufficiently to brief first-stage programming will be randomly assigned a second time to either an extended parent- or youth-focused second-stage programming. Measures of proximal intervention response and measures of potential candidate tailoring variables for developing ATS within this sample are detailed. RESULTS Results of the described pilot study will include information regarding feasibility and acceptability of the SMART design. This information will be used to refine a subsequent full-scale SMART. CONCLUSIONS The use of a SMART to develop ATS for prevention will increase the efficiency and effectiveness of prevention programing for youth with developing conduct problems. PMID:25256135

Sequential EMT-MET induces neuronal conversion through Sox2

PubMed Central

He, Songwei; Chen, Jinlong; Zhang, Yixin; Zhang, Mengdan; Yang, Xiao; Li, Yuan; Sun, Hao; Lin, Lilong; Fan, Ke; Liang, Lining; Feng, Chengqian; Wang, Fuhui; Zhang, Xiao; Guo, Yiping; Pei, Duanqing; Zheng, Hui

2017-01-01

Direct neuronal conversion can be achieved with combinations of small-molecule compounds and growth factors. Here, by studying the first or induction phase of the neuronal conversion induced by defined 5C medium, we show that the Sox2-mediated switch from early epithelial–mesenchymal transition (EMT) to late mesenchymal–epithelial transition (MET) within a high proliferation context is essential and sufficient for the conversion from mouse embryonic fibroblasts (MEFs) to TuJ+ cells. At the early stage, insulin and basic fibroblast growth factor (bFGF)-induced cell proliferation, early EMT, the up-regulation of Stat3 and Sox2, and the subsequent activation of neuron projection. Up-regulated Sox2 then induced MET and directed cells towards a neuronal fate at the late stage. Inhibiting either stage of this sequential EMT-MET impaired the conversion. In addition, Sox2 could replace sequential EMT-MET to induce a similar conversion within a high proliferation context, and its functions were confirmed with other neuronal conversion protocols and MEFs reprogramming. Therefore, the critical roles of the sequential EMT-MET were implicated in direct cell fate conversion in addition to reprogramming, embryonic development and cancer progression. PMID:28580167

Development of a rapid method for the sequential extraction and subsequent quantification of fatty acids and sugars from avocado mesocarp tissue.

PubMed

Meyer, Marjolaine D; Terry, Leon A

2008-08-27

Methods devised for oil extraction from avocado (Persea americana Mill.) mesocarp (e.g., Soxhlet) are usually lengthy and require operation at high temperature. Moreover, methods for extracting sugars from avocado tissue (e.g., 80% ethanol, v/v) do not allow for lipids to be easily measured from the same sample. This study describes a new simple method that enabled sequential extraction and subsequent quantification of both fatty acids and sugars from the same avocado mesocarp tissue sample. Freeze-dried mesocarp samples of avocado cv. Hass fruit of different ripening stages were extracted by homogenization with hexane and the oil extracts quantified for fatty acid composition by GC. The resulting filter residues were readily usable for sugar extraction with methanol (62.5%, v/v). For comparison, oil was also extracted using the standard Soxhlet technique and the resulting thimble residue extracted for sugars as before. An additional experiment was carried out whereby filter residues were also extracted using ethanol. Average oil yield using the Soxhlet technique was significantly (P < 0.05) higher than that obtained by homogenization with hexane, although the difference remained very slight, and fatty acid profiles of the oil extracts following both methods were very similar. Oil recovery improved with increasing ripeness of the fruit with minor differences observed in the fatty acid composition during postharvest ripening. After lipid removal, methanolic extraction was superior in recovering sucrose and perseitol as compared to 80% ethanol (v/v), whereas mannoheptulose recovery was not affected by solvent used. The method presented has the benefits of shorter extraction time, lower extraction temperature, and reduced amount of solvent and can be used for sequential extraction of fatty acids and sugars from the same sample.

Estimation After a Group Sequential Trial.

PubMed

Milanzi, Elasma; Molenberghs, Geert; Alonso, Ariel; Kenward, Michael G; Tsiatis, Anastasios A; Davidian, Marie; Verbeke, Geert

2015-10-01

Group sequential trials are one important instance of studies for which the sample size is not fixed a priori but rather takes one of a finite set of pre-specified values, dependent on the observed data. Much work has been devoted to the inferential consequences of this design feature. Molenberghs et al (2012) and Milanzi et al (2012) reviewed and extended the existing literature, focusing on a collection of seemingly disparate, but related, settings, namely completely random sample sizes, group sequential studies with deterministic and random stopping rules, incomplete data, and random cluster sizes. They showed that the ordinary sample average is a viable option for estimation following a group sequential trial, for a wide class of stopping rules and for random outcomes with a distribution in the exponential family. Their results are somewhat surprising in the sense that the sample average is not optimal, and further, there does not exist an optimal, or even, unbiased linear estimator. However, the sample average is asymptotically unbiased, both conditionally upon the observed sample size as well as marginalized over it. By exploiting ignorability they showed that the sample average is the conventional maximum likelihood estimator. They also showed that a conditional maximum likelihood estimator is finite sample unbiased, but is less efficient than the sample average and has the larger mean squared error. Asymptotically, the sample average and the conditional maximum likelihood estimator are equivalent. This previous work is restricted, however, to the situation in which the the random sample size can take only two values, N = n or N = 2 n . In this paper, we consider the more practically useful setting of sample sizes in a the finite set { n 1 , n 2 , …, n L }. It is shown that the sample average is then a justifiable estimator , in the sense that it follows from joint likelihood estimation, and it is consistent and asymptotically unbiased. We also show why simulations can give the false impression of bias in the sample average when considered conditional upon the sample size. The consequence is that no corrections need to be made to estimators following sequential trials. When small-sample bias is of concern, the conditional likelihood estimator provides a relatively straightforward modification to the sample average. Finally, it is shown that classical likelihood-based standard errors and confidence intervals can be applied, obviating the need for technical corrections.

Dynamic fractionation of trace metals in soil and sediment samples using rotating coiled column extraction and sequential injection microcolumn extraction: a comparative study.

PubMed

Rosende, Maria; Savonina, Elena Yu; Fedotov, Petr S; Miró, Manuel; Cerdà, Víctor; Wennrich, Rainer

2009-09-15

Dynamic fractionation has been recognized as an appealing alternative to conventional equilibrium-based sequential extraction procedures (SEPs) for partitioning of trace elements (TE) in environmental solid samples. This paper reports the first attempt for harmonization of flow-through dynamic fractionation using two novel methods, the so-called sequential injection microcolumn (SIMC) extraction and rotating coiled column (RCC) extraction. In SIMC extraction, a column packed with the solid sample is clustered in a sequential injection system, while in RCC, the particulate matter is retained under the action of centrifugal forces. In both methods, the leachants are continuously pumped through the solid substrates by the use of either peristaltic or syringe pumps. A five-step SEP was selected for partitioning of Cu, Pb and Zn in water soluble/exchangeable, acid-soluble, easily reducible, easily oxidizable and moderately reducible fractions from 0.2 to 0.5 g samples at an extractant flow rate of 1.0 mL min(-1) prior to leachate analysis by inductively coupled plasma-atomic emission spectrometry. Similarities and discrepancies between both dynamic approaches were ascertained by fractionation of TE in certified reference materials, namely, SRM 2711 Montana Soil and GBW 07311 sediment, and two real soil samples as well. Notwithstanding the different extraction conditions set by both methods, similar trends of metal distribution were in generally found. The most critical parameters for reliable assessment of mobilizable pools of TE in worse-case scenarios are the size-distribution of sample particles, the density of particles, the content of organic matter and the concentration of major elements. For reference materials and a soil rich in organic matter, the extraction in RCC results in slightly higher recoveries of environmentally relevant fractions of TE, whereas SIMC leaching is more effective for calcareous soils.

Effectiveness of Implemented Interventions on Pathologic Nodal Staging of Non-Small Cell Lung Cancer.

PubMed

Ray, Meredith A; Faris, Nicholas R; Smeltzer, Matthew P; Fehnel, Carrie; Houston-Harris, Cheryl; Levy, Paul; Wiggins, Lynn; Sachdev, Vishal; Robbins, Todd; Spencer, David; Osarogiagbon, Raymond U

2018-03-10

Accurate pathologic nodal staging improves early-stage non-small-cell lung cancer survival. In an ongoing implementation study, we measured the impact of a surgical lymph node specimen collection kit and a more thorough pathologic gross dissection method, on attainment of guideline-recommended pathologic nodal staging quality. We prospectively collected data on curative-intent non-small cell lung cancer resections from 2009-2016 from 11 hospitals in 4 contiguous Dartmouth Hospital Referral Regions. We categorized patients into 4 groups based on exposure to the two interventions in our staggered implementation study design. We used Chi-squared tests to examine the differences in demographic and disease characteristics and surgical quality criteria across implementation groups. Of 2,469 patients, 1,615 (65%) received neither intervention; 167 (7%) received only the pathology intervention; 264 (11%) received only the surgery intervention; 423 (17%) had both. Rates of non-examination of lymph nodes reduced sequentially in the order of no intervention, novel dissection, kit, and combined interventions, including non-examination of: any lymph nodes, hilar/intrapulmonary and mediastinal nodes (p<0.001 for all comparisons). The rates of attainment of National Comprehensive Cancer Network, Commission on Cancer, American Joint Committee on Cancer, and American College of Surgeons Oncology Group guidelines increased significantly in the same sequential order (p<0.001 for all comparisons). The combined effect of two interventions to improve pathologic lymph node examination has a greater effect on attainment of a range of surgical quality criteria than either intervention alone. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Sequential injection spectrophotometric determination of oxybenzone in lipsticks.

PubMed

Salvador, A; Chisvert, A; Camarasa, A; Pascual-Martí, M C; March, J G

2001-08-01

A sequential injection (SI) procedure for the spectrophotometric determination of oxybenzone in lipsticks is reported. The colorimetric reaction between nickel and oxybenzone was used. SI parameters such as sample solution volume, reagent solution volume, propulsion flow rate and reaction coil length were studied. The limit of detection was 3 microg ml(-1). The sensitivity was 0.0108+/-0.0002 ml microg(-1). The relative standard deviations of the results were between 6 and 12%. The real concentrations of samples and the values obtained by HPLC were comparable. Microwave sample pre-treatment allowed the extraction of oxybenzone with ethanol, thus avoiding the use of toxic organic solvents. Ethanol was also used as carrier in the SI system. Seventy-two injections per hour can be performed, which means a sample frequency of 24 h(-1) if three replicates are measured for each sample.

Simultaneous sequential monitoring of efficacy and safety led to masking of effects.

PubMed

van Eekelen, Rik; de Hoop, Esther; van der Tweel, Ingeborg

2016-08-01

Usually, sequential designs for clinical trials are applied on the primary (=efficacy) outcome. In practice, other outcomes (e.g., safety) will also be monitored and influence the decision whether to stop a trial early. Implications of simultaneous monitoring on trial decision making are yet unclear. This study examines what happens to the type I error, power, and required sample sizes when one efficacy outcome and one correlated safety outcome are monitored simultaneously using sequential designs. We conducted a simulation study in the framework of a two-arm parallel clinical trial. Interim analyses on two outcomes were performed independently and simultaneously on the same data sets using four sequential monitoring designs, including O'Brien-Fleming and Triangular Test boundaries. Simulations differed in values for correlations and true effect sizes. When an effect was present in both outcomes, competition was introduced, which decreased power (e.g., from 80% to 60%). Futility boundaries for the efficacy outcome reduced overall type I errors as well as power for the safety outcome. Monitoring two correlated outcomes, given that both are essential for early trial termination, leads to masking of true effects. Careful consideration of scenarios must be taken into account when designing sequential trials. Simulation results can help guide trial design. Copyright © 2016 Elsevier Inc. All rights reserved.

A Bayesian Framework for Reliability Analysis of Spacecraft Deployments

NASA Technical Reports Server (NTRS)

Evans, John W.; Gallo, Luis; Kaminsky, Mark

2012-01-01

Deployable subsystems are essential to mission success of most spacecraft. These subsystems enable critical functions including power, communications and thermal control. The loss of any of these functions will generally result in loss of the mission. These subsystems and their components often consist of unique designs and applications for which various standardized data sources are not applicable for estimating reliability and for assessing risks. In this study, a two stage sequential Bayesian framework for reliability estimation of spacecraft deployment was developed for this purpose. This process was then applied to the James Webb Space Telescope (JWST) Sunshield subsystem, a unique design intended for thermal control of the Optical Telescope Element. Initially, detailed studies of NASA deployment history, "heritage information", were conducted, extending over 45 years of spacecraft launches. This information was then coupled to a non-informative prior and a binomial likelihood function to create a posterior distribution for deployments of various subsystems uSing Monte Carlo Markov Chain sampling. Select distributions were then coupled to a subsequent analysis, using test data and anomaly occurrences on successive ground test deployments of scale model test articles of JWST hardware, to update the NASA heritage data. This allowed for a realistic prediction for the reliability of the complex Sunshield deployment, with credibility limits, within this two stage Bayesian framework.

Loading, Release, Biodegradation, and Biocompatibility of a Nanovector Delivery System

NASA Technical Reports Server (NTRS)

Ferrai, Mauro; Tasciotti, Ennio

2012-01-01

A nanovector multistage system has been created to overcome or bypass sequential barriers within the human body, in order to deliver a therapeutic or imaging agent to a specific location. This innovation consists of a composition that includes two or more stages of particles, such that smaller, later-stage particles are contained in the larger, early-stage particles. An active agent, such as a therapeutic agent or imaging agent, is preferentially delivered and/or localized to a particular target site in the body of a subject. The multistage composition overcomes multiple biological barriers in the body. The multistage composition also allows for simultaneous delivery and localization at the same or different target sites of multiple active agents.

Biased lineups: sequential presentation reduces the problem.

PubMed

Lindsay, R C; Lea, J A; Nosworthy, G J; Fulford, J A; Hector, J; LeVan, V; Seabrook, C

1991-12-01

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.

Screening and staging for non-small cell lung cancer by serum laser Raman spectroscopy.

PubMed

Wang, Hong; Zhang, Shaohong; Wan, Limei; Sun, Hong; Tan, Jie; Su, Qiucheng

2018-08-05

Lung cancer is the leading cause of cancer-related death worldwide. Current clinical screening methods to detect lung cancer are expensive and associated with many complications. Raman spectroscopy is a spectroscopic technique that offers a convenient method to gain molecular information about biological samples. In this study, we measured the serum Raman spectral intensity of healthy volunteers and patients with different stages of non-small cell lung cancer. The purpose of this study was to evaluate the application of serum laser Raman spectroscopy as a low cost alternative method in the screening and staging of non-small cell lung cancer (NSCLC). The Raman spectra of the sera of peripheral venous blood were measured with a LabRAM HR 800 confocal Micro Raman spectrometer for individuals from five groups including 14 healthy volunteers (control group), 23 patients with stage I NSCLC (stage I group), 24 patients with stage II NSCLC (stage II group), 19 patients with stage III NSCLC (stage III group), 11 patients with stage IV NSCLC (stage IV group). Each serum sample was measured 3 times at different spots and the average spectra represented the signal of Raman spectra in each case. The Raman spectrum signal data of the five groups were statistically analyzed by analysis of variance (ANOVA), principal component analysis (PCA), linear discriminant analysis (LDA), and cross-validation. Raman spectral intensity was sequentially reduced in serum samples from control group, stage I group, stage II group and stage III/IV group. The strongest peak intensity was observed in the control group, and the weakest one was found in the stage III/IV group at bands of 848 cm -1 , 999 cm -1 , 1152 cm -1 , 1446 cm -1 and 1658 cm -1 (P < 0.05). Linear discriminant analysis showed that the sensitivity to identify healthy people, stage I, stage II, and stage III/IV NSCLC was 86%, 65%, 75%, and 87%, respectively; the specificity was 95%, 94%, 88%, and 93%, respectively; and the overall accuracy rate was 92% (71/77). The laser Raman spectroscopy can effectively identify patients with stage I, stage II or stage III/IV Non-Small Cell Lung cancer using patient serum samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Sequential solvent extraction for forms of antimony in five selected coals

USGS Publications Warehouse

Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

2008-01-01

Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and two from the Illinois Basin in the United States. The Sb abundance in these samples is in the range of 0.11-0.43 ??g/g. The forms of Sb in coals were studied by sequential solvent extraction. The six forms of Sb are water soluble, ion changeable, organic matter bound, carbonate bound, silicate bound, and sulfide bound. Results of sequential extraction show that silicate-bound Sb is the most abundant form in these coals. Silicate- plus sulfide-bound Sb accounts for more than half of the total Sb in all coals. Bituminous coals are higher in organic matterbound Sb than anthracite and natural coke, indicating that the Sb in the organic matter may be incorporated into silicate and sulfide minerals during metamorphism. ?? 2008 by The University of Chicago. All rights reserved.

One-sided truncated sequential t-test: application to natural resource sampling

Treesearch

Gary W. Fowler; William G. O' Regan

1974-01-01

A new procedure for constructing one-sided truncated sequential t-tests and its application to natural resource sampling are described. Monte Carlo procedures were used to develop a series of one-sided truncated sequential t-tests and the associated approximations to the operating characteristic and average sample number functions. Different truncation points and...

Extracellular annexins and dynamin are important for sequential steps in myoblast fusion

PubMed Central

Leikina, Evgenia; Melikov, Kamran; Sanyal, Sarmistha; Verma, Santosh K.; Eun, Bokkee; Gebert, Claudia; Pfeifer, Karl; Lizunov, Vladimir A.; Kozlov, Michael M.

2013-01-01

Myoblast fusion into multinucleated myotubes is a crucial step in skeletal muscle development and regeneration. Here, we accumulated murine myoblasts at the ready-to-fuse stage by blocking formation of early fusion intermediates with lysophosphatidylcholine. Lifting the block allowed us to explore a largely synchronized fusion. We found that initial merger of two cell membranes detected as lipid mixing involved extracellular annexins A1 and A5 acting in a functionally redundant manner. Subsequent stages of myoblast fusion depended on dynamin activity, phosphatidylinositol(4,5)bisphosphate content, and cell metabolism. Uncoupling fusion from preceding stages of myogenesis will help in the analysis of the interplay between protein machines that initiate and complete cell unification and in the identification of additional protein players controlling different fusion stages. PMID:23277424

Cluster designs to assess the prevalence of acute malnutrition by lot quality assurance sampling: a validation study by computer simulation

PubMed Central

Olives, Casey; Pagano, Marcello; Deitchler, Megan; Hedt, Bethany L; Egge, Kari; Valadez, Joseph J

2009-01-01

Traditional lot quality assurance sampling (LQAS) methods require simple random sampling to guarantee valid results. However, cluster sampling has been proposed to reduce the number of random starting points. This study uses simulations to examine the classification error of two such designs, a 67×3 (67 clusters of three observations) and a 33×6 (33 clusters of six observations) sampling scheme to assess the prevalence of global acute malnutrition (GAM). Further, we explore the use of a 67×3 sequential sampling scheme for LQAS classification of GAM prevalence. Results indicate that, for independent clusters with moderate intracluster correlation for the GAM outcome, the three sampling designs maintain approximate validity for LQAS analysis. Sequential sampling can substantially reduce the average sample size that is required for data collection. The presence of intercluster correlation can impact dramatically the classification error that is associated with LQAS analysis. PMID:20011037

Sequential Anaerobic/Aerobic Digestion for Enhanced Carbon/Nitrogen Removal and Cake Odor Reduction.

PubMed

Ahmad, Muneer; Denee, Marco Abel; Jiang, Hao; Eskicioglu, Cigdem; Kadota, Paul; Gregonia, Theresa

2016-12-01

  Anaerobic digestion (AD) has been proven to be an effective process for the treatment of wastewater sludge. However, it produces high levels of ammonia in the digester effluent, which may jeopardize meeting stringent nutrient discharge limits. In this study, the effect of a sequential anaerobic/aerobic (AN/AERO) digestion and a single-stage conventional AN digestion (as control) was investigated on mixed (primary + secondary) sludge generated by the Annacis Island wastewater treatment plant (WWTP) (BC, Canada). An overall sludge retention time (SRT) of 22.5 days under three different scenarios was chosen based on the current operational SRT of the digesters at the Annacis Island WWTP. The steady state results have shown that sequential AN/AERO digestion configurations achieved up to 11% higher volatile solids (VS) removal and 72% lower ammonia generation over single-stage conventional AN digestion. Furthermore, sequential AN/AERO system also showed enhanced dewaterability, improved fecal coliform destruction and reduced digested cake odors over control digesters.

On Two-Stage Multiple Comparison Procedures When There Are Unequal Sample Sizes in the First Stage.

ERIC Educational Resources Information Center

Wilcox, Rand R.

1984-01-01

Two stage multiple-comparison procedures give an exact solution to problems of power and Type I errors, but require equal sample sizes in the first stage. This paper suggests a method of evaluating the experimentwise Type I error probability when the first stage has unequal sample sizes. (Author/BW)

Ensemble Sampling vs. Time Sampling in Molecular Dynamics Simulations of Thermal Conductivity

DOE PAGES

Gordiz, Kiarash; Singh, David J.; Henry, Asegun

2015-01-29

In this report we compare time sampling and ensemble averaging as two different methods available for phase space sampling. For the comparison, we calculate thermal conductivities of solid argon and silicon structures, using equilibrium molecular dynamics. We introduce two different schemes for the ensemble averaging approach, and show that both can reduce the total simulation time as compared to time averaging. It is also found that velocity rescaling is an efficient mechanism for phase space exploration. Although our methodology is tested using classical molecular dynamics, the ensemble generation approaches may find their greatest utility in computationally expensive simulations such asmore » first principles molecular dynamics. For such simulations, where each time step is costly, time sampling can require long simulation times because each time step must be evaluated sequentially and therefore phase space averaging is achieved through sequential operations. On the other hand, with ensemble averaging, phase space sampling can be achieved through parallel operations, since each ensemble is independent. For this reason, particularly when using massively parallel architectures, ensemble sampling can result in much shorter simulation times and exhibits similar overall computational effort.« less

Clinical Significance of Plasma Epstein-Barr Virus DNA in Pulmonary Lymphoepithelioma-like Carcinoma (LELC) Patients.

PubMed

Xie, Mian; Wu, Xiaojun; Wang, Fang; Zhang, Jinjun; Ben, Xiaosong; Zhang, Jiexia; Li, Xiaoxiang

2018-02-01

Primary pulmonary lymphoepithelioma-like carcinoma (LELC) is a histologically distinctive subtype of NSCLC and an Epstein-Barr virus (EBV)-associated epithelial neoplasm. We investigated the clinical significance of plasma concentrations of EBV DNA in patients with pulmonary LELC. Two independent sets of plasma samples from a total of 429 patients with patients with pulmonary LELC (287 initial and 142 confirmatory) were available for EBV DNA determination. Plasma samples from the patients were subjected to a real-time quantitative polymerase chain reaction before treatment and 3 months after radical resection. Cutoff points were determined for pretreatment plasma EBV DNA concentration (low <4000 copies/mL versus high ≥4000 copies/mL) on the basis of a measure of heterogeneity with the log-rank test statistic with respect to overall survival (OS). The Kaplan-Meier method and Cox regression were used to evaluate the relationship between plasma EBV DNA concentrations and clinical outcome. Among patients with advanced-stage pulmonary LELC who underwent sequential blood draws, we evaluated the relationship between change in disease status and change in EBV DNA concentrations by using nonparametric tests. High EBV DNA concentration was associated with shorter OS in the initial, confirmatory, and combined data sets (combined data set hazard ratio = 3.67, 95% confidence interval: 2.72-4.38, p < 0.001). These findings persisted after multivariable adjustment. Compared with low EBV DNA concentration, high EBV DNA concentration was associated with shorter OS in patients with any stage of disease. High EBV DNA concentration was also associated with shorter disease-free survival (DFS) in patients with stage I/II disease. Patients with persistently detectable plasma EBV DNA had significantly poorer OS (p < 0.001) and DFS (p < 0.001) than did patients with undetectable EBV DNA 3 months after radical resection. In patients who underwent sequential evaluation of EBV DNA, an association was identified between an increase in EBV DNA concentration and a poor response to treatment and disease progression of pulmonary LELC. High baseline EBV DNA concentration is an independent poor prognostic marker in patients with pulmonary LELC. These results should be confirmed in larger prospective trials. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

PubMed

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2013-02-01

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design. Copyright © 2012 Elsevier Ltd. All rights reserved.

Matrix solid phase dispersion-assisted BCR sequential extraction method for metal partitioning in surface estuarine sediments.

PubMed

Martínez-Fernández, Marta; Barciela-Alonso, María Carmen; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

2011-01-15

The BCR (the Community Bureau of Reference) of the European Union sequential extraction scheme for metal partitioning in estuarine sediments has been accelerated by using a matrix solid phase dispersion (MSPD) approach. The MSPD assisted BCR procedure consists of passing the extractants proposed by conventional BCR protocol (0.11 M acetic acid, 0.1M hydroxylammonium chloride and 8.8M hydrogen peroxide plus 1M ammonium acetate) through the dispersed sample packaged inside a disposable syringe. Different silica-, magnesium- and aluminium-based materials were tested as dispersing agents and sea sand was found to offer the best performances. Variables for assisting the three stages of the BCR protocol were optimized, and accurate results were obtained when assisting the first and the third stages (exchangeable and oxidizable fractions, respectively). However, lack of accuracy was observed when assisting the second step (reducible fraction) and this result agrees with most of the assisted BCR procedures for which extracting the reducible fraction is the most troublesome stage. The organic matter oxidation (third stage) was successfully assisted by passing hydrogen peroxide at 50°C through the dispersed sample inside de syringe just before passing ammonium acetate. Therefore, the time-consuming and unsafe conventional organic matter oxidation processes, commonly performed even for microwave/ultrasounds assisted BCR procedures, are totally avoided. Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector. The target elements were Cd, Co, Cr, Mn, Ni, Sr and Zn (first stage), Cd, Co and Ni (second stage), and Co, Cr, Mn, Ni, Sr and Zn (third stage). Repeatability of the method (n=7) was good, and RSDs values of 9, 10, 10, 8, 8, 3 and 8% was obtained for Cd, Co, Cr, Mn, Ni, Sr and Zn, respectively (first stage); 10, 9 and 9% for Cd, Co and Ni, respectively (second stage); and 6, 2, 3, 4, 7 and 9% Co, Cr, Mn, Ni, Sr and Zn, respectively (third stage). The procedure was also validated by analysing two certified reference materials (CRM 601 and CRM 701). Good accuracy was obtained for the target elements extracted at the first stage: Cd (4.0 ± 0.1 and 7.3 ± 0.09 μg g(-1) in CRM 601 and CRM 701, respectively), Cr (0.36 ± 0.008 and 2.21 ± 0.08 μg g(-1) in CRM 601 and CRM 701, respectively), Ni (8.0 ± 0.3 and 15.4 ± 0.3 μg g(-1) in CRM 601 and CRM 701, respectively) and Zn (262 ± 3 and 203 ± 3 μg g(-1) in CRM 601 and CRM 701, respectively). Also, good accuracy was observed for elements extracted at the third step: Cd (1.8 ± 0.09 and 0.29 ± 0.03 μg g(-1) in CRM 601 and CRM 701, respectively), Cr (145 ± 4 μg g(-1) in CRM 701), Ni (8.2 ± 0.7 and 15.1 ± 0.5 μg g(-1) in CRM 601 and CRM 701, respectively) and Zn (45 ± 0.7 μg g(-1) in CRM 701). Copyright © 2010 Elsevier B.V. All rights reserved.

Growth patterns of an intertidal gastropod as revealed by oxygen isotope analysis

NASA Astrophysics Data System (ADS)

Bean, J. R.; Hill, T. M.; Guerra, C.

2007-12-01

The size and morphology of mollusk shells are affected by environmental conditions. As a result, it is difficult to assess growth rate, population age structure, shell morphologies associated with ontogenetic stages, and to compare life history patterns across various environments. Oxygen isotope analysis is a useful tool for estimating minimum ages and growth rates of calcium carbonate secreting organisms. Calcite shell material from members of two northern California populations of the intertidal muricid gastropod Acanthinucella spirata was sampled for isotopic analysis. Individual shells were sampled from apex to margin, thus providing a sequential record of juvenile and adult growth. A. spirata were collected from a sheltered habitat in Tomales Bay and from an exposed reef in Bolinas. Abiotic factors, such as temperature, wave exposure, and substrate consistency, and biotic composition differ significantly between these sites, possibly resulting in local adaptations and variation in life history and growth patterns. Shell morphology of A. spirata changes with age as internal shell margin thickenings of denticle rows associated with external growth bands are irregularly accreted. It is not known when, either seasonally and/or ontogentically, these thickenings and bands form or whether inter or intra-populational variation exists. Preliminary results demonstrate the seasonal oxygen isotopic variability present at the two coastal sites, indicating 5-6 degC changes from winter to summertime temperatures; these data are consistent with local intertidal temperature records. Analysis of the seasonal patterns indicate that: 1) differences in growth rate and seasonal growth patterns at different ontogenetic stages within populations, and 2) differences in growth patterns and possibly age structure between the two A. spirata populations. These findings indicate that isotopic analyses, in addition to field observations and morphological measurements, are necessary to assess life history strategies and compare population dynamics under varying environmental conditions.

Precision alignment and mounting apparatus

NASA Technical Reports Server (NTRS)

Preston, Dennis R. (Inventor)

1993-01-01

An alignment and mounting apparatus for mounting two modules (10,12) includes a first portion having a cylindrical alignment pin (16) projecting normal to a module surface, a second portion having a three-stage alignment guide (18) including a shoehorn flange (34), a Y-slot (42) and a V-block (22) which sequentially guide the alignment pin (16) with successively finer precision and a third portion in the form of a spring-loaded captive fastener (20) for connecting the two modules after alignment is achieved.

A novel approach for small sample size family-based association studies: sequential tests.

PubMed

Ilk, Ozlem; Rajabli, Farid; Dungul, Dilay Ciglidag; Ozdag, Hilal; Ilk, Hakki Gokhan

2011-08-01

In this paper, we propose a sequential probability ratio test (SPRT) to overcome the problem of limited samples in studies related to complex genetic diseases. The results of this novel approach are compared with the ones obtained from the traditional transmission disequilibrium test (TDT) on simulated data. Although TDT classifies single-nucleotide polymorphisms (SNPs) to only two groups (SNPs associated with the disease and the others), SPRT has the flexibility of assigning SNPs to a third group, that is, those for which we do not have enough evidence and should keep sampling. It is shown that SPRT results in smaller ratios of false positives and negatives, as well as better accuracy and sensitivity values for classifying SNPs when compared with TDT. By using SPRT, data with small sample size become usable for an accurate association analysis.

Crystal Growth and Dissolution of Methylammonium Lead Iodide Perovskite in Sequential Deposition: Correlation between Morphology Evolution and Photovoltaic Performance.

PubMed

Hsieh, Tsung-Yu; Huang, Chi-Kai; Su, Tzu-Sen; Hong, Cheng-You; Wei, Tzu-Chien

2017-03-15

Crystal morphology and structure are important for improving the organic-inorganic lead halide perovskite semiconductor property in optoelectronic, electronic, and photovoltaic devices. In particular, crystal growth and dissolution are two major phenomena in determining the morphology of methylammonium lead iodide perovskite in the sequential deposition method for fabricating a perovskite solar cell. In this report, the effect of immersion time in the second step, i.e., methlyammonium iodide immersion in the morphological, structural, optical, and photovoltaic evolution, is extensively investigated. Supported by experimental evidence, a five-staged, time-dependent evolution of the morphology of methylammonium lead iodide perovskite crystals is established and is well connected to the photovoltaic performance. This result is beneficial for engineering optimal time for methylammonium iodide immersion and converging the solar cell performance in the sequential deposition route. Meanwhile, our result suggests that large, well-faceted methylammonium lead iodide perovskite single crystal may be incubated by solution process. This offers a low cost route for synthesizing perovskite single crystal.

The Perceptions of Change and Change Readiness in Junior and Senior Engineering & Technology Students

NASA Astrophysics Data System (ADS)

Moler, Perry J.

The purpose of this study was to understand what perceptions junior and senior engineering & technology students have about change, change readiness, and selected attributes, skills, and abilities. The selected attributes, skills, and abilities for this study were lifelong learning, leadership, and self-efficacy. The business environment of today is dynamic, with any number of internal and external events requiring an organization to adapt through the process of organizational development. Organizational developments affect businesses as a whole, but these developments are more evident in fields related to engineering and technology. Which require employees working through such developments be flexible and adaptable to a new professional environment. This study was an Explanatory Sequential Mixed Methods design, with Stage One being an online survey that collected individuals' perceptions of change, change readiness, and associated attributes, skills, and abilities. Stage Two was a face-to-face interview with a random sample of individuals who agreed to be interviewed in Stage One. This process was done to understand why students' perceptions are what they are. By using a mixed-method study, a more complete understanding of the current perceptions of students was developed, thus allowing external stakeholders' such as Human Resource managers more insight into the individuals they seek to recruit. The results from Stage One, one sample T-test with a predicted mean of 3.000 for this study indicated that engineering & technology students have a positive perceptions of Change Mean = 3.7024; Change Readiness Mean = 3.9313; Lifelong Learning Mean = 4.571; Leadership = 4.036; and Self-Efficacy Mean = 4.321. A One-way ANOVA was also conducted to understand the differences between traditional and non-traditional student regarding change and change readiness. The results of the ANOVA test indicated there were no significant differences between these two groups. The results from Stage Two showed that students perceived change as both positive and negative. This perception stems from their life experiences rather than from educational or professional experiences. The same can be said for the concepts of change readiness, lifelong learning, leadership, and self-efficacy. This indicates that engineering & technology programs should implement these concepts into their curriculum to better prepare engineering & technology students to enter into professional careers.

Mathematical Problem Solving through Sequential Process Analysis

ERIC Educational Resources Information Center

Codina, A.; Cañadas, M. C.; Castro, E.

2015-01-01

Introduction: The macroscopic perspective is one of the frameworks for research on problem solving in mathematics education. Coming from this perspective, our study addresses the stages of thought in mathematical problem solving, offering an innovative approach because we apply sequential relations and global interrelations between the different…

On the origin of multiply-impulsive emission from solar flares. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Karpen, J. T.

1980-01-01

A set of solar hard X-ray bursts observed with the hard X-ray burst spectrometer on board the OSO-5 satellite was analyzed. The multiply-impulsive two stage events were selected on the basis of both morphological characteristics and association with appropriate phenomena at other wavelengths. Coincident radio, soft X-ray, H-alpha interplanetary particle, and magnetographic data were obtained from several observatories, to aid in developing a comprehensive picture of the physical processes underlying these complex bursts. Two classes of multiply impulsive bursts were identified: events whose components spikes apparently originate in one location, and events in which groups of spikes appear to come from separate regions which flare sequentially. The origin of multiplicity in the case of a single source region remains unidentified. Purely impulsive emissions show no sign of betatron acceleration, thus eliminating this mechanisn as a candidate for inducing multiply spiked structure. The majority of the two stage bursts, however, exhibited spectral behavior consistent with the betatron model, for the first few minutes of the second stage. Betatron acceleration thus has been identified as a common second stage phenomenon.

Vibration Based Sun Gear Damage Detection

NASA Technical Reports Server (NTRS)

Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

2013-01-01

Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

Process for conversion of lignin to reformulated hydrocarbon gasoline

DOEpatents

Shabtai, Joseph S.; Zmierczak, Wlodzimierz W.; Chornet, Esteban

1999-09-28

A process for converting lignin into high-quality reformulated hydrocarbon gasoline compositions in high yields is disclosed. The process is a two-stage, catalytic reaction process that produces a reformulated hydrocarbon gasoline product with a controlled amount of aromatics. In the first stage, a lignin material is subjected to a base-catalyzed depolymerization reaction in the presence of a supercritical alcohol as a reaction medium, to thereby produce a depolymerized lignin product. In the second stage, the depolymerized lignin product is subjected to a sequential two-step hydroprocessing reaction to produce a reformulated hydrocarbon gasoline product. In the first hydroprocessing step, the depolymerized lignin is contacted with a hydrodeoxygenation catalyst to produce a hydrodeoxygenated intermediate product. In the second hydroprocessing step, the hydrodeoxygenated intermediate product is contacted with a hydrocracking/ring hydrogenation catalyst to produce the reformulated hydrocarbon gasoline product which includes various desirable naphthenic and paraffinic compounds.

Development of a sequential workflow based on LC-PRM for the verification of endometrial cancer protein biomarkers in uterine aspirate samples.

PubMed

Martinez-Garcia, Elena; Lesur, Antoine; Devis, Laura; Campos, Alexandre; Cabrera, Silvia; van Oostrum, Jan; Matias-Guiu, Xavier; Gil-Moreno, Antonio; Reventos, Jaume; Colas, Eva; Domon, Bruno

2016-08-16

About 30% of endometrial cancer (EC) patients are diagnosed at an advanced stage of the disease, which is associated with a drastic decrease in the 5-year survival rate. The identification of biomarkers in uterine aspirate samples, which are collected by a minimally invasive procedure, would improve early diagnosis of EC. We present a sequential workflow to select from a list of potential EC biomarkers, those which are the most promising to enter a validation study. After the elimination of confounding contributions by residual blood proteins, 52 potential biomarkers were analyzed in uterine aspirates from 20 EC patients and 18 non-EC controls by a high-resolution accurate mass spectrometer operated in parallel reaction monitoring mode. The differential abundance of 26 biomarkers was observed, and among them ten proteins showed a high sensitivity and specificity (AUC > 0.9). The study demonstrates that uterine aspirates are valuable samples for EC protein biomarkers screening. It also illustrates the importance of a biomarker verification phase to fill the gap between discovery and validation studies and highlights the benefits of high resolution mass spectrometry for this purpose. The proteins verified in this study have an increased likelihood to become a clinical assay after a subsequent validation phase.

A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

ERIC Educational Resources Information Center

Luong, Ming; Stevens, Jeff

2015-01-01

The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

Sequential biases in accumulating evidence

PubMed Central

Huggins, Richard; Dogo, Samson Henry

2015-01-01

Whilst it is common in clinical trials to use the results of tests at one phase to decide whether to continue to the next phase and to subsequently design the next phase, we show that this can lead to biased results in evidence synthesis. Two new kinds of bias associated with accumulating evidence, termed ‘sequential decision bias’ and ‘sequential design bias’, are identified. Both kinds of bias are the result of making decisions on the usefulness of a new study, or its design, based on the previous studies. Sequential decision bias is determined by the correlation between the value of the current estimated effect and the probability of conducting an additional study. Sequential design bias arises from using the estimated value instead of the clinically relevant value of an effect in sample size calculations. We considered both the fixed‐effect and the random‐effects models of meta‐analysis and demonstrated analytically and by simulations that in both settings the problems due to sequential biases are apparent. According to our simulations, the sequential biases increase with increased heterogeneity. Minimisation of sequential biases arises as a new and important research area necessary for successful evidence‐based approaches to the development of science. © 2015 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. PMID:26626562

Dipolar-dephasing 13C NMR studies of decomposed wood and coalified xylem tissue: Evidence for chemical structural changes associated with defunctionalization of lignin structural units during coalification

USGS Publications Warehouse

Hatcher, P.G.

1988-01-01

A series of decomposed and coalified gymnosperm woods was examined by conventional solid-state 13C nuclear magnetic resonance (NMR) and by dipolar-dephasing NMR techniques. The results of these NMR studies for a histologically related series of samples provide clues as to the nature of codification reactions that lead to the defunctionalization of lignin-derived aromatic structures. These reactions sequentially involve the following: (1) loss of methoxyl carbons from guaiacyl structural units with replacement by hydroxyls and increased condensation; (2) loss of hydroxyls or aryl ethers with replacement by hydrogen as rank increases from lignin to high-volatile bituminous coal; (3) loss of alkyl groups with continued replacement by hydrogen. The dipolar-dephasing data show that the early stages of coalification in samples examined (lignin to lignite) involve a decreasing degree of protonation on aromatic rings and suggest that condensation is significant during coalification at this early stage. An increasing degree of protonation on aromatic rings is observed as the rank of the sample increases from lignite to anthracite.

Three-year-olds obey the sample size principle of induction: the influence of evidence presentation and sample size disparity on young children's generalizations.

PubMed

Lawson, Chris A

2014-07-01

Three experiments with 81 3-year-olds (M=3.62years) examined the conditions that enable young children to use the sample size principle (SSP) of induction-the inductive rule that facilitates generalizations from large rather than small samples of evidence. In Experiment 1, children exhibited the SSP when exemplars were presented sequentially but not when exemplars were presented simultaneously. Results from Experiment 3 suggest that the advantage of sequential presentation is not due to the additional time to process the available input from the two samples but instead may be linked to better memory for specific individuals in the large sample. In addition, findings from Experiments 1 and 2 suggest that adherence to the SSP is mediated by the disparity between presented samples. Overall, these results reveal that the SSP appears early in development and is guided by basic cognitive processes triggered during the acquisition of input. Copyright © 2013 Elsevier Inc. All rights reserved.

Two-step sequential pretreatment for the enhanced enzymatic hydrolysis of coffee spent waste.

PubMed

Ravindran, Rajeev; Jaiswal, Swarna; Abu-Ghannam, Nissreen; Jaiswal, Amit K

2017-09-01

In the present study, eight different pretreatments of varying nature (physical, chemical and physico-chemical) followed by a sequential, combinatorial pretreatment strategy was applied to spent coffee waste to attain maximum sugar yield. Pretreated samples were analysed for total reducing sugar, individual sugars and generation of inhibitory compounds such as furfural and hydroxymethyl furfural (HMF) which can hinder microbial growth and enzyme activity. Native spent coffee waste was high in hemicellulose content. Galactose was found to be the predominant sugar in spent coffee waste. Results showed that sequential pretreatment yielded 350.12mg of reducing sugar/g of substrate, which was 1.7-fold higher than in native spent coffee waste (203.4mg/g of substrate). Furthermore, extensive delignification was achieved using sequential pretreatment strategy. XRD, FTIR, and DSC profiles of the pretreated substrates were studied to analyse the various changes incurred in sequentially pretreated spent coffee waste as opposed to native spent coffee waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hoping for More: The Influence of Outcome Desirability on Information Seeking and Predictions about Relative Quantities

ERIC Educational Resources Information Center

Scherer, Aaron M.; Windschitl, Paul D.; O'Rourke, Jillian; Smith, Andrew R.

2012-01-01

People must often engage in sequential sampling in order to make predictions about the relative quantities of two options. We investigated how directional motives influence sampling selections and resulting predictions in such cases. We used a paradigm in which participants had limited time to sample items and make predictions about which side of…

Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

ERIC Educational Resources Information Center

Cizdziel, James V.

2011-01-01

In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

The value of sequential bone marrow biopsy and laparotomy and splenectomy in a series of 127 consecutive untreated patients with non-Hodgkin's lymphoma.

PubMed Central

Rosenberg, S. A.; Dorfman, R. F.; Kaplan, H. S.

1975-01-01

The information derived from sequential routine bone marrow biopsies and exploratory laparotomy with splenectomy in 127 consecutive untreated protocol patients with malignant lymphomata other than Hodgkin's disease is reviewed. Of the 61 patients with diffuse lymphomata, 36% changed stage after these diagnostic procedures, usually to a more advanced stage. Of the 66 patients with nodular lymphomata, 62% had a change in stage, almost all to more advanced stages, usually as a result of bone marrow biopsy. The correlation of pathological stages to clinical stages is presented for each of the Rappaport classification subgroups and for several age groups. The precise indications for exploratory laparotomy with splenectomy cannot yet be defined. These will have to await the results of current clinical trials, which may reveal to what degree an improvement in therapeutic results has been achieved as a result of a better knowledge of the extent of disease. PMID:1237307

To Catch a Thief.

ERIC Educational Resources Information Center

Lindsay, R. C. L.

1998-01-01

Describes the differences between normal and sequential lineups and their effects on eyewitnesses to crime. After a staged crime in a college lab, students were shown photographs in either normal lineup style or sequential style. 35% of eyewitnesses shown all photographs at the same time mistakenly picked an innocent person. Only 18% shown…

Sequential Pointing in Children and Adults.

ERIC Educational Resources Information Center

Badan, Maryse; Hauert, Claude-Alain; Mounoud, Pierre

2000-01-01

Four experiments investigated the development of visuomotor control in sequential pointing in tasks varying in difficulty among 6- to 10-year-olds and adults. Comparisons across difficulty levels and ages suggest that motor development is not a uniform fine-tuning of stable strategies. Findings raise argument for stage characteristics of…

Adult Development: Implications for Adult Education. Overview. ERIC Digest No. 41.

ERIC Educational Resources Information Center

Naylor, Michele

Various researchers, including Carl Jung, Charlotte Buhler, Erik Erikson, and Robert Havighurst, have formulated sequential models of adult development. More recent investigators, such as Daniel Levinson, Roger Gould, and Gail Sheehy have formulated age-related sequential models of adult development that view the various stages of adulthood in…

Development of a sequential injection-square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode.

PubMed

dos Santos, Luciana B O; Infante, Carlos M C; Masini, Jorge C

2010-03-01

This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level.

Safety of two sequential whole bladder photodynamic therapy (WBPDT) treatments in the management of resistant bladder cancer

NASA Astrophysics Data System (ADS)

Nseyo, Unyime O.; Barnes, C. R.; Martin, Jessicca I.; Lamm, Donald L.; Carpenter, Cindy

2003-06-01

While 55 - 60% of newly diagnosed bladder cancers are superficial, a significant number recur as higher grade and/or stage tumors. WBPDT has been used to treat some of these recurrent superficial tumors, although its use has been associated with dose-dependent side effects. Preclinical investigation of three sequential WBPDT treatments using lower PDT dose in normal canine bladder resulted in a lack of permanent bladder contracture. Lower dose single PDT treatment has shown less durable tumor response; however, sequential WBPDT treatments with lower dose may result in durable tumor response. Five patients (4 male, 1 female), average age 65.6 (62-72 years), with recurrent or resistant superficial TCC of the bladder received two WBPDT treatments. First treatment occurred at baseline and the second treatment at 6 months. Photofrin (1.5 mg/kg) was given intravenously 48 hours prior to each cystoscopic treatment with laser light (630 nm, Coherent Lambda-Plus laser). Total light treatment doses were 1500 - 2500 Joules at baseline and 1000- 1500 Joules at 6 months. Moderate irritative bladder symptoms occurred in all patients the first week post PDT. No cases of bladder contracture have occurred. 4 of 5 patients showed no evidence of disease during the follow-up period (12 - 18 months post second treatment). One patient had a recurrence at 18 months post second treatment. Mean disease-free interval is 16.2 months. The safety of two sequential WBPDT treatments is suggested by this preliminary data. Assessment of efficacy will be possible wit a large number of patients and a longer follow-up period.

Preliminary Examination of the Interstellar Collector of Stardust

NASA Technical Reports Server (NTRS)

Westphal, A. J.; Allen, C.; Bastien, R.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Butterworth, A. L.; Floss, C.; Flynn, G.;

Clinical experiences derived from implementation of an easy to use concept for treatment of wound healing by secondary intention and guidance in selection of appropriate dressings.

PubMed

Braumann, Chris; Guenther, Nina; Menenakos, Charalambos; Muenzberg, Helga; Pirlich, Matthias; Lochs, Herbert; Mueller, Joachim M

2011-06-01

The main objective of this case-cohort-type observational study conducted at different Surgical Departments of the Charité-Universitätsmedizin in Berlin was to evaluate the sequential use concept first described by Systagenix Wound Management in 2007. Fifty-two patients with different wound healing by secondary intention were treated for 7 weeks at the Charité-Universitätsmedizin in Berlin. A multidisciplinary team worked together to reach consensus in wound assessment; in classification of infection status according to the criteria described by European Wound Management Association (EWMA); in treatment protocol and on dressings to be used to 'cover' wounds. Before dressing application, all wounds were cleaned from debris. Following the sequential use concept, wounds classified as stages 2 and 3 were dressed with SILVERCEL(®) and TIELLE(®) or TIELLE PLUS(®) to 'clean' the wounds. After 2-3 weeks, treatment was changed to PROMOGRAN PRISMA(®) and TIELLE(®) to 'close and cover' wounds, thus providing optimal wound healing. Wounds classified as non infected were dressed with PROMOGRAN PRISMA(®) and TIELLE(®) during the complete treatment period. Patients were asked to evaluate the treatment using a simplified questionnaire developed at the Charité-Universitätsmedizin in Berlin. Wounds comprised 37 surgical procedures, 8 chronic mixed ulcer, 4 pressure sores, 1 diabetic foot ulcer, 1 venous leg ulcer, and 1 mixed arterial/venous ulcer. At baseline, 12 wounds were classified as stage 3, 38 wounds as stage 2 and 2 wounds as stage 1. After 7 weeks of treatment, all patients showed a positive clinical response to the sequential use treatment. Results of wound size showed a high significant progression of wound healing expressed with a profound reduction of wound area (P in all measurements <0·001, chi-square test) and improved granulation. This study summarises the clinical experiences derived from the evaluation of the sequential use concept in the daily clinical practice of wound treatment. On the basis of the wound healing results, patients' evaluation of treatment and the clinicians' and staff experiences, this concept was implemented at different Surgical Departments of the Charité-Universitätsmedizin in Berlin. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Some sequential, distribution-free pattern classification procedures with applications

NASA Technical Reports Server (NTRS)

Poage, J. L.

1971-01-01

Some sequential, distribution-free pattern classification techniques are presented. The decision problem to which the proposed classification methods are applied is that of discriminating between two kinds of electroencephalogram responses recorded from a human subject: spontaneous EEG and EEG driven by a stroboscopic light stimulus at the alpha frequency. The classification procedures proposed make use of the theory of order statistics. Estimates of the probabilities of misclassification are given. The procedures were tested on Gaussian samples and the EEG responses.

Sequential sampling of ribes populations in the control of white pine blister rust (Cronartium ribicola Fischer) in California

Treesearch

Harold R. Offord

1966-01-01

Sequential sampling based on a negative binomial distribution of ribes populations required less than half the time taken by regular systematic line transect sampling in a comparison test. It gave the same control decision as the regular method in 9 of 13 field trials. A computer program that permits sequential plans to be built readily for other white pine regions is...

Relative Quantification and Higher-Order Modeling of the Plasma Glycan Cancer Burden Ratio in Ovarian Cancer Case-Control Samples

PubMed Central

Hecht, Elizabeth S.; Scholl, Elizabeth H.; Walker, S. Hunter; Taylor, Amber D.; Cliby, William A.; Motsinger-Reif, Alison A.; Muddiman, David C.

2016-01-01

An early-stage, population-wide biomarker for ovarian cancer (OVC) is essential to reverse its high mortality rate. Aberrant glycosylation by OVC has been reported, but studies have yet to identify an N-glycan with sufficiently high specificity. We curated a human biorepository of 82 case-control plasma samples, with 27%, 12%, 46%, and 15% falling across stages I–IV, respectively. For relatve quantitation, glycans were analyzed by the individuality normalization when labeling with glycan hydrazide tags (INLIGHT) strategy for enhanced electrospray ionization, MS/MS analysis. Sixty-three glycan cancer burden ratios (GBRs), defined as the log10 ratio of the case-control extracted ion chromatogram abundances, were calculated above the limit of detection. The final GBR models, built using stepwise forward regression, included three significant terms: OVC stage, normalized mean GBR, and tag chemical purity; glycan class, fucosylation, or sialylation were not significant variables. After Bonferroni correction, seven N-glycans were identified as significant (p < 0.05), and after false discovery rate correction, an additional four glycans were determined to be significant (p < 0.05), with one borderline (p = 0.05). For all N-glycans, the vectors of the effects from stages II–IV were sequentially reversed, suggesting potential biological changes in OVC morphology or in host response. PMID:26347193

Sampling methods, dispersion patterns, and fixed precision sequential sampling plans for western flower thrips (Thysanoptera: Thripidae) and cotton fleahoppers (Hemiptera: Miridae) in cotton.

PubMed

Parajulee, M N; Shrestha, R B; Leser, J F

2006-04-01

A 2-yr field study was conducted to examine the effectiveness of two sampling methods (visual and plant washing techniques) for western flower thrips, Frankliniella occidentalis (Pergande), and five sampling methods (visual, beat bucket, drop cloth, sweep net, and vacuum) for cotton fleahopper, Pseudatomoscelis seriatus (Reuter), in Texas cotton, Gossypium hirsutum (L.), and to develop sequential sampling plans for each pest. The plant washing technique gave similar results to the visual method in detecting adult thrips, but the washing technique detected significantly higher number of thrips larvae compared with the visual sampling. Visual sampling detected the highest number of fleahoppers followed by beat bucket, drop cloth, vacuum, and sweep net sampling, with no significant difference in catch efficiency between vacuum and sweep net methods. However, based on fixed precision cost reliability, the sweep net sampling was the most cost-effective method followed by vacuum, beat bucket, drop cloth, and visual sampling. Taylor's Power Law analysis revealed that the field dispersion patterns of both thrips and fleahoppers were aggregated throughout the crop growing season. For thrips management decision based on visual sampling (0.25 precision), 15 plants were estimated to be the minimum sample size when the estimated population density was one thrips per plant, whereas the minimum sample size was nine plants when thrips density approached 10 thrips per plant. The minimum visual sample size for cotton fleahoppers was 16 plants when the density was one fleahopper per plant, but the sample size decreased rapidly with an increase in fleahopper density, requiring only four plants to be sampled when the density was 10 fleahoppers per plant. Sequential sampling plans were developed and validated with independent data for both thrips and cotton fleahoppers.

Sulfide oxidation and acid mine drainage formation within two active tailings impoundments in the Golden Quadrangle of the Apuseni Mountains, Romania.

PubMed

Sima, Mihaela; Dold, Bernhard; Frei, Linda; Senila, Marin; Balteanu, Dan; Zobrist, Jurg

2011-05-30

Sulfidic mine tailings have to be classified as one of the major source of hazardous materials leading to water contamination. This study highlights the processes leading to sulfide oxidation and acid mine drainage (AMD) formation in the active stage of two tailings impoundments located in the southern part of the Apuseni Mountains, in Romania, a well-known region for its long-term gold-silver and metal mining activity. Sampling was undertaken when both impoundments were still in operation in order to assess their actual stage of oxidation and long-term behavior in terms of the potential for acid mine drainage generation. Both tailings have high potential for AMD formation (2.5 and 3.7 wt.% of pyrite equivalent, respectively) with lesser amount of carbonates (5.6 and 3.6 wt.% of calcite equivalent) as neutralization potential (ABA=-55.6 and -85.1 tCaCO(3)/1000 t ) and showed clear signs of sulfide oxidation yet during operation. Sequential extraction results indicate a stronger enrichment and mobility of elements in the oxidized tailings: Fe as Fe(III) oxy-hydroxides and oxides (transformation from sulfide minerals, leaching in oxidation zone), Ca mainly in water soluble and exchangeable form where gypsum and calcite are dissolved and higher mobility of Cu for Ribita and Pb for Mialu. Two processes leading to the formation of mine drainage at this stage could be highlighted (1) a neutral Fe(II) plume forming in the impoundment with ferrihydrite precipitation at its outcrop and (2) acid mine drainage seeping in the unsaturated zone of the active dam, leading to the formation of schwertmannite at its outcrop. Copyright © 2011 Elsevier B.V. All rights reserved.

The subtyping of primary aldosteronism by adrenal vein sampling: sequential blood sampling causes factitious lateralization.

PubMed

Rossitto, Giacomo; Battistel, Michele; Barbiero, Giulio; Bisogni, Valeria; Maiolino, Giuseppe; Diego, Miotto; Seccia, Teresa M; Rossi, Gian Paolo

2018-02-01

The pulsatile secretion of adrenocortical hormones and a stress reaction occurring when starting adrenal vein sampling (AVS) can affect the selectivity and also the assessment of lateralization when sequential blood sampling is used. We therefore tested the hypothesis that a simulated sequential blood sampling could decrease the diagnostic accuracy of lateralization index for identification of aldosterone-producing adenoma (APA), as compared with bilaterally simultaneous AVS. In 138 consecutive patients who underwent subtyping of primary aldosteronism, we compared the results obtained simultaneously bilaterally when starting AVS (t-15) and 15 min after (t0), with those gained with a simulated sequential right-to-left AVS technique (R ⇒ L) created by combining hormonal values obtained at t-15 and at t0. The concordance between simultaneously obtained values at t-15 and t0, and between simultaneously obtained values and values gained with a sequential R ⇒ L technique, was also assessed. We found a marked interindividual variability of lateralization index values in the patients with bilaterally selective AVS at both time point. However, overall the lateralization index simultaneously determined at t0 provided a more accurate identification of APA than the simulated sequential lateralization indexR ⇒ L (P = 0.001). Moreover, regardless of which side was sampled first, the sequential AVS technique induced a sequence-dependent overestimation of lateralization index. While in APA patients the concordance between simultaneous AVS at t0 and t-15 and between simultaneous t0 and sequential technique was moderate-to-good (K = 0.55 and 0.66, respectively), in non-APA patients, it was poor (K = 0.12 and 0.13, respectively). Sequential AVS generates factitious between-sides gradients, which lower its diagnostic accuracy, likely because of the stress reaction arising upon starting AVS.

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain

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

Alonso, E.; Aparicio, I.; Santos, J.L.

2009-01-15

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible andmore » exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal)« less

Sequential extraction of metals from mixed and digested sludge from aerobic WWTPs sited in the south of Spain.

PubMed

Alonso, E; Aparicio, I; Santos, J L; Villar, P; Santos, A

2009-01-01

The content of heavy metals is the major limitation to the application of sewage sludge in soil. However, assessment of the pollution by total metal determination does not reveal the true environmental impact. It is necessary to apply sequential extraction techniques to obtain suitable information about their bioavailability or toxicity. In this paper, sequential extraction of metals from sludge before and after aerobic digestion was applied to sludge from five WWTPs in southern Spain to obtain information about the influence of the digestion treatment in the concentration of the metals. The percentage of each metal as residual, oxidizable, reducible and exchangeable form was calculated. For this purpose, sludge samples were collected from two different points of the plants, namely, sludge from the mixture (primary and secondary sludge) tank (mixed sludge, MS) and the digested-dewatered sludge (final sludge, FS). Heavy metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Ti and Zn, were extracted following the sequential extraction scheme proposed by the Standards, Measurements and Testing Programme of the European Commission and determined by inductively-coupled plasma atomic emission spectrometry. The total concentration of heavy metals in the measured sludge samples did not exceed the limits set out by European legislation and were mainly associated with the two less-available fractions (27-28% as oxidizable metal and 44-50% as residual metal). However, metals as Co (64% in MS and 52% in FS samples), Mn (82% in MS and 79% in FS), Ni (32% in MS and 26% in FS) and Zn (79% in MS and 62% in FS) were present at important percentages as available forms. In addition, results showed a clear increase of the concentration of metals after sludge treatment in the proportion of two less-available fractions (oxidizable and residual metal).

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable properties

NASA Astrophysics Data System (ADS)

Ellingham, Thomas; Kharbas, Hrishikesh; Manitiu, Mihai; Scholz, Guenter; Turng, Lih-Sheng

2018-03-01

A three-stage molding process involving microcellular injection molding with core retraction and an "out-of-mold" expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

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

Chen, Pei-Chun; Chen, Yen-Ching; Research Center for Gene, Environment, and Human Health, College of Public Health, National Taiwan University, Taiwan

Purpose: To identify germline polymorphisms to predict concurrent chemoradiation therapy (CCRT) response in esophageal cancer patients. Materials and Methods: A total of 139 esophageal cancer patients treated with CCRT (cisplatin-based chemotherapy combined with 40 Gy of irradiation) and subsequent esophagectomy were recruited at the National Taiwan University Hospital between 1997 and 2008. After excluding confounding factors (i.e., females and patients aged {>=}70 years), 116 patients were enrolled to identify single nucleotide polymorphisms (SNPs) associated with specific CCRT responses. Genotyping arrays and mass spectrometry were used sequentially to determine germline polymorphisms from blood samples. These polymorphisms remain stable throughout disease progression,more » unlike somatic mutations from tumor tissues. Two-stage design and additive genetic models were adopted in this study. Results: From the 26 SNPs identified in the first stage, 2 SNPs were found to be significantly associated with CCRT response in the second stage. Single nucleotide polymorphism rs16863886, located between SGPP2 and FARSB on chromosome 2q36.1, was significantly associated with a 3.93-fold increase in pathologic complete response to CCRT (95% confidence interval 1.62-10.30) under additive models. Single nucleotide polymorphism rs4954256, located in ZRANB3 on chromosome 2q21.3, was associated with a 3.93-fold increase in pathologic complete response to CCRT (95% confidence interval 1.57-10.87). The predictive accuracy for CCRT response was 71.59% with these two SNPs combined. Conclusions: This is the first study to identify germline polymorphisms with a high accuracy for predicting CCRT response in the treatment of esophageal cancer.« less

Win-Stay, Lose-Sample: a simple sequential algorithm for approximating Bayesian inference.

PubMed

Bonawitz, Elizabeth; Denison, Stephanie; Gopnik, Alison; Griffiths, Thomas L

2014-11-01

People can behave in a way that is consistent with Bayesian models of cognition, despite the fact that performing exact Bayesian inference is computationally challenging. What algorithms could people be using to make this possible? We show that a simple sequential algorithm "Win-Stay, Lose-Sample", inspired by the Win-Stay, Lose-Shift (WSLS) principle, can be used to approximate Bayesian inference. We investigate the behavior of adults and preschoolers on two causal learning tasks to test whether people might use a similar algorithm. These studies use a "mini-microgenetic method", investigating how people sequentially update their beliefs as they encounter new evidence. Experiment 1 investigates a deterministic causal learning scenario and Experiments 2 and 3 examine how people make inferences in a stochastic scenario. The behavior of adults and preschoolers in these experiments is consistent with our Bayesian version of the WSLS principle. This algorithm provides both a practical method for performing Bayesian inference and a new way to understand people's judgments. Copyright © 2014 Elsevier Inc. All rights reserved.

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

Consumption of psychoactive substances in educational institutions: an inquiry into the state of affairs in the schools of Córdoba.

PubMed

Lucchese, M S M; Burrone, M S; Enders, J E; Fernández, A R

2014-01-01

This study describes and analyses the consumption of psychoactive substances in educational institutions, the school environment conditions and its relation to the school standing of the students. In the first stage, a quantitative evaluation was performed, based on the records of the Second National Survey of Secondary School Students carried out in Córdoba in 2005; the second stage used a qualitative approach. A multistage probabilistic sample of 4593 students was used for the quantitative assessment. The analysis comprised summary measurements, multivariate and factorial correspondence analysis, in all cases with a significance level of p < 0.05. For the qualitative stage, an ethnographic approach was applied. The state schools were chosen using an intentional, cumulative and sequential sampling method. Ten in-depth interviews were carried out to gather qualitative data that was analyzed using the comparative constant method. Results evince that consumption is lower among morning-shift students and that grade repetition and behavior problems are associated to consumption of illegal drugs. Furthermore, it was detected that students in night-shift schools with low academic and disciplinary demand standards have a higher probability of consumption. It is clear that as academic standards decrease, consumption increases.

Estimation of mortality for stage-structured zooplankton populations: What is to be done?

NASA Astrophysics Data System (ADS)

Ohman, Mark D.

2012-05-01

Estimation of zooplankton mortality rates in field populations is a challenging task that some contend is inherently intractable. This paper examines several of the objections that are commonly raised to efforts to estimate mortality. We find that there are circumstances in the field where it is possible to sequentially sample the same population and to resolve biologically caused mortality, albeit with error. Precision can be improved with sampling directed by knowledge of the physical structure of the water column, combined with adequate sample replication. Intercalibration of sampling methods can make it possible to sample across the life history in a quantitative manner. Rates of development can be constrained by laboratory-based estimates of stage durations from temperature- and food-dependent functions, mesocosm studies of molting rates, or approximation of development rates from growth rates, combined with the vertical distributions of organisms in relation to food and temperature gradients. Careful design of field studies guided by the assumptions of specific estimation models can lead to satisfactory mortality estimates, but model uncertainty also needs to be quantified. We highlight additional issues requiring attention to further advance the field, including the need for linked cooperative studies of the rates and causes of mortality of co-occurring holozooplankton and ichthyoplankton.

Collection methods and quality assessment for Esche-richia coli, water quality, and microbial source tracking data within Tumacácori National Historical Park and the upper Santa Cruz River, Arizona, 2015-16

USGS Publications Warehouse

Paretti, Nicholas; Coes, Alissa L.; Kephart, Christopher M.; Mayo, Justine

2018-03-05

Tumacácori National Historical Park protects the culturally important Mission, San José de Tumacácori, while also managing a portion of the ecologically diverse riparian corridor of the Santa Cruz River. This report describes the methods and quality assurance procedures used in the collection of water samples for the analysis of Escherichia coli (E. coli), microbial source tracking markers, suspended sediment, water-quality parameters, turbidity, and the data collection for discharge and stage; the process for data review and approval is also described. Finally, this report provides a quantitative assessment of the quality of the E. coli, microbial source tracking, and suspended sediment data.The data-quality assessment revealed that bias attributed to field and laboratory contamination was minimal, with E. coli detections in only 3 out of 33 field blank samples analyzed. Concentrations in the field blanks were several orders of magnitude lower than environmental concentrations. The microbial source tracking (MST) field blank was below the detection limit for all MST markers analyzed. Laboratory blanks for E. coli at the USGS Arizona Water Science Center and laboratory blanks for MST markers at the USGS Ohio Water Microbiology Laboratory were all below the detection limit. Irreplicate data for E. coli and suspended sediment indicated that bias was not introduced to the data by combining samples collected using discrete sampling methods with samples collected using automatic sampling methods.The split and sequential E. coli replicate data showed consistent analytical variability and a single equation was developed to explain the variability of E. coli concentrations. An additional analysis of analytical variability for E. coli indicated analytical variability around 18 percent relative standard deviation and no trend was observed in the concentration during the processing and analysis of multiple split-replicates. Two replicate samples were collected for MST and individual markers were compared for a base flow and flood sample. For the markers found in common between the two types of samples, the relative standard deviation for the base flow sample was more than 3 times greater than the markers in the flood sample. Sequential suspended sediment replicates had a relative standard deviation of about 1.3 percent, indicating that environmental and analytical variability was minimal.A holding time review and laboratory study analysis supported the extended holding times required for this investigation. Most concentrations for flood and base-flow samples were within the theoretical variability specified in the most probable number approach suggesting that extended hold times did not overly influence the final concentrations reported.

Spatial Patterns and Sequential Sampling Plans for Predators of Aphis glycines (Hemiptera: Aphididae) in Minnesota Soybean.

PubMed

Tran, Anh K; Koch, Robert L

2017-06-01

The soybean aphid, Aphis glycines Matsumura, is an economically important soybean pest. Many studies have demonstrated that predatory insects are important in suppressing A. glycines population growth. However, to improve the utilization of predators in A. glycines management, sampling plans need to be developed and validated for predators. Aphid predators were sampled in soybean fields near Rosemount, Minnesota, from 2006-2007 and 2013-2015 with sample sizes of 20-80 plants. Sampling plans were developed for Orius insidiosus (Say), Harmonia axyridis (Pallas), and all aphidophagous Coccinellidae species combined. Taylor's power law parameters from the regression of log variance versus log mean suggested aggregated spatial patterns for immature and adult stages combined for O. insidiosus, H. axyridis, and Coccinellidae in soybean fields. Using the parameters from Taylor's power law and Green's method, sequential fixed-precision sampling plans were developed to estimate the density for each predator taxon at desired precision levels of 0.10 and 0.25. To achieve a desired precision of 0.10 and 0.25, the average sample number (ASN) ranged from 398-713 and 64-108 soybean plants, respectively, for all species. Resulting ASNs were relatively large and assumed impractical for most purposes; therefore, the desired precision levels were adjusted to determine the level of precision associated with a more practical ASN. Final analysis indicated an ASN of 38 soybean plants provided precision of 0.32-0.40 for the predators. Development of sampling plans should provide guidance for improved estimation of predator densities for A. glycines pest management programs and for research purposes. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging.

PubMed

Marques, Manuel J; Bradu, Adrian; Podoleanu, Adrian Gh

2014-05-01

We report a Talbot bands-based optical coherence tomography (OCT) system capable of producing longitudinal B-scan OCT images and en-face scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo. The OCT channel employs a broadband optical source and a spectrometer. A gap is created between the sample and reference beams while on their way towards the spectrometer's dispersive element to create Talbot bands. The spatial separation of the two beams facilitates collection by an SLO channel of optical power originating exclusively from the retina, deprived from any contribution from the reference beam. Three different modes of operation are presented, constrained by the minimum integration time of the camera used in the spectrometer and by the galvo-scanners' scanning rate: (i) a simultaneous acquisition mode over the two channels, useful for small size imaging, that conserves the pixel-to-pixel correspondence between them; (ii) a hybrid sequential mode, where the system switches itself between the two regimes and (iii) a sequential "on-demand" mode, where the system can be used in either OCT or SLO regimes for as long as required. The two sequential modes present varying degrees of trade-off between pixel-to-pixel correspondence and independent full control of parameters within each channel. Images of the optic nerve and fovea regions obtained in the simultaneous (i) and in the hybrid sequential mode (ii) are presented.

Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging

PubMed Central

Marques, Manuel J.; Bradu, Adrian; Podoleanu, Adrian Gh.

2014-01-01

We report a Talbot bands-based optical coherence tomography (OCT) system capable of producing longitudinal B-scan OCT images and en-face scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo. The OCT channel employs a broadband optical source and a spectrometer. A gap is created between the sample and reference beams while on their way towards the spectrometer’s dispersive element to create Talbot bands. The spatial separation of the two beams facilitates collection by an SLO channel of optical power originating exclusively from the retina, deprived from any contribution from the reference beam. Three different modes of operation are presented, constrained by the minimum integration time of the camera used in the spectrometer and by the galvo-scanners’ scanning rate: (i) a simultaneous acquisition mode over the two channels, useful for small size imaging, that conserves the pixel-to-pixel correspondence between them; (ii) a hybrid sequential mode, where the system switches itself between the two regimes and (iii) a sequential “on-demand” mode, where the system can be used in either OCT or SLO regimes for as long as required. The two sequential modes present varying degrees of trade-off between pixel-to-pixel correspondence and independent full control of parameters within each channel. Images of the optic nerve and fovea regions obtained in the simultaneous (i) and in the hybrid sequential mode (ii) are presented. PMID:24877006

Polymorphism in liver-stage malaria vaccine candidate proteins: immune evasion and implications for vaccine design.

PubMed

Flanagan, Katie L; Wilson, Kirsty L; Plebanski, Magdalena

2016-01-01

The pre-erythrocytic stage of infection by malaria parasites represents a key target for vaccines that aim to eradicate malaria. Two important broad immune evasion strategies that can interfere with vaccine efficacy include the induction of dendritic cell (DC) dysfunction and regulatory T cells (Tregs) by blood-stage malaria parasites, leading to inefficient priming of T cells targeting liver-stage infections. The parasite also uses 'surgical strike' strategies, whereby polymorphism in pre-erythrocytic antigens can interfere with host immunity. Specifically, we review how even single amino acid changes in T cell epitopes can lead to loss of binding to major histocompatibility complex (MHC), lack of cross-reactivity, or antagonism and immune interference, where simultaneous or sequential stimulation with related variants of the same T cell epitope can cause T cell anergy or the conversion of effector to immunosuppressive T cell phenotypes.

A Simulation Approach to Assessing Sampling Strategies for Insect Pests: An Example with the Balsam Gall Midge

PubMed Central

Carleton, R. Drew; Heard, Stephen B.; Silk, Peter J.

2013-01-01

Estimation of pest density is a basic requirement for integrated pest management in agriculture and forestry, and efficiency in density estimation is a common goal. Sequential sampling techniques promise efficient sampling, but their application can involve cumbersome mathematics and/or intensive warm-up sampling when pests have complex within- or between-site distributions. We provide tools for assessing the efficiency of sequential sampling and of alternative, simpler sampling plans, using computer simulation with “pre-sampling” data. We illustrate our approach using data for balsam gall midge (Paradiplosis tumifex) attack in Christmas tree farms. Paradiplosis tumifex proved recalcitrant to sequential sampling techniques. Midge distributions could not be fit by a common negative binomial distribution across sites. Local parameterization, using warm-up samples to estimate the clumping parameter k for each site, performed poorly: k estimates were unreliable even for samples of n∼100 trees. These methods were further confounded by significant within-site spatial autocorrelation. Much simpler sampling schemes, involving random or belt-transect sampling to preset sample sizes, were effective and efficient for P. tumifex. Sampling via belt transects (through the longest dimension of a stand) was the most efficient, with sample means converging on true mean density for sample sizes of n∼25–40 trees. Pre-sampling and simulation techniques provide a simple method for assessing sampling strategies for estimating insect infestation. We suspect that many pests will resemble P. tumifex in challenging the assumptions of sequential sampling methods. Our software will allow practitioners to optimize sampling strategies before they are brought to real-world applications, while potentially avoiding the need for the cumbersome calculations required for sequential sampling methods. PMID:24376556

Variable aperture-based ptychographical iterative engine method

NASA Astrophysics Data System (ADS)

Sun, Aihui; Kong, Yan; Meng, Xin; He, Xiaoliang; Du, Ruijun; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

2018-02-01

A variable aperture-based ptychographical iterative engine (vaPIE) is demonstrated both numerically and experimentally to reconstruct the sample phase and amplitude rapidly. By adjusting the size of a tiny aperture under the illumination of a parallel light beam to change the illumination on the sample step by step and recording the corresponding diffraction patterns sequentially, both the sample phase and amplitude can be faithfully reconstructed with a modified ptychographical iterative engine (PIE) algorithm. Since many fewer diffraction patterns are required than in common PIE and the shape, the size, and the position of the aperture need not to be known exactly, this proposed vaPIE method remarkably reduces the data acquisition time and makes PIE less dependent on the mechanical accuracy of the translation stage; therefore, the proposed technique can be potentially applied for various scientific researches.

Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling.

PubMed

Koopmeiners, Joseph S; Feng, Ziding

2011-01-01

The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves.

Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling

PubMed Central

Koopmeiners, Joseph S.; Feng, Ziding

2013-01-01

The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves. PMID:24039313

Quantifying the combined effects of pronase and benzalkonium chloride in removing late-stage Listeria monocytogenes-Escherichia coli dual-species biofilms.

PubMed

Rodríguez-López, Pedro; Puga, Carmen H; Orgaz, Belén; Cabo, Marta L

2017-09-01

This work presents the assessment of the effectivity of a pronase (PRN)-benzalkonium chloride (BAC) sequential treatment in removing Listeria monocytogenes-Escherichia coli dual-species biofilms grown on stainless steel (SS) using fluorescence microscopy and plate count assays. The effects of PRN-BAC on the occupied area (OA) by undamaged cells in 168 h dual-species samples were determined using a first-order factorial design. Empirical equations significantly (r 2 = 0.927) described a negative individual effect of BAC and a negative interactive effect of PRN-BAC achieving OA reductions up to 46%. After treatment, high numbers of remaining attached and released viable and cultivable E. coli cells were detected in PRN-BAC combinations when low BAC concentrations were used. Therefore, at appropriate BAC doses, in addition to biofilm removal, sequential application of PRN and BAC represents an appealing strategy for pathogen control on SS surfaces while hindering the dispersion of live cells into the environment.

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media

PubMed Central

Hennings, Justin M.; Zimmer, Randall L.; Nabli, Henda; Davis, J. Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L.

2015-01-01

Objective: Validate single versus sequential culture media for murine embryo development. Design: Prospective laboratory experiment. Setting: Assisted Reproduction Laboratory. Animals: Murine embryos. Interventions: Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. Main Outcome Measures: On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4’,6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Results: Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Conclusions: Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. PMID:26668049

Improved Murine Blastocyst Quality and Development in a Single Culture Medium Compared to Sequential Culture Media.

PubMed

Hennings, Justin M; Zimmer, Randall L; Nabli, Henda; Davis, J Wade; Sutovsky, Peter; Sutovsky, Miriam; Sharpe-Timms, Kathy L

2016-03-01

Validate single versus sequential culture media for murine embryo development. Prospective laboratory experiment. Assisted Reproduction Laboratory. Murine embryos. Thawed murine zygotes cultured for 3 or 5 days (d3 or d5) in single or sequential embryo culture media developed for human in vitro fertilization. On d3, zygotes developing to the 8 cell (8C) stage or greater were quantified using 4',6-diamidino-2-phenylindole (DAPI), and quality was assessed by morphological analysis. On d5, the number of embryos reaching the blastocyst stage was counted. DAPI was used to quantify total nuclei and inner cell mass nuclei. Localization of ubiquitin C-terminal hydrolase L1 (UCHL1) and ubiquitin C-terminal hydrolase L3 (UCHL3) was reference points for evaluating cell quality. Comparing outcomes in single versus to sequential media, the odds of embryos developing to the 8C stage on d3 were 2.34 time greater (P = .06). On d5, more embryos reached the blastocyst stage (P = <.0001), hatched, and had significantly more trophoblast cells (P = .005) contributing to the increased total cell number. Also at d5, localization of distinct cytoplasmic UCHL1 and nuclear UCHL3 was found in high-quality hatching blastocysts. Localization of UCHL1 and UCHL3 was diffuse and inappropriately dispersed throughout the cytoplasm in low-quality nonhatching blastocysts. Single medium yields greater cell numbers, an increased growth rate, and more hatching of murine embryos. Cytoplasmic UCHL1 and nuclear UHCL3 localization patterns were indicative of embryo quality. Our conclusions are limited to murine embryos but one might speculate that single medium may also be more beneficial for human embryo culture. Human embryo studies are needed. © The Author(s) 2015.

The artificial and natural isotopes distribution in sedge (Carex L.) biomass from the Yenisei River flood-plain: Adaptation of the sequential elution technique.

PubMed

Kropacheva, Marya; Melgunov, Mikhail; Makarova, Irina

2017-02-01

The study of migration pathways of artificial isotopes in the flood-plain biogeocoenoses, impacted by the nuclear fuel cycle plants, requires determination of isotope speciations in the biomass of higher terrestrial plants. The optimal method for their determination is the sequential elution technique (SET). The technique was originally developed to study atmospheric pollution by metals and has been applied to lichens, terrestrial and aquatic bryophytes. Due to morphological and physiological differences, it was necessary to adapt SET for new objects: coastal macrophytes growing on the banks of the Yenisei flood-plain islands in the near impact zone of Krasnoyarsk Mining and Chemical Combine (KMCC). In the first version of SET, 20 mM Na 2 EDTA was used as a reagent at the first stage; in the second version of SET, it was 1 M CH 3 COONH 4 . Four fractions were extracted. Fraction I included elements from the intercellular space and those connected with the outer side of the cell wall. Fraction II contained intracellular elements; fraction III contained elements firmly bound in the cell wall and associated structures; fraction IV contained insoluble residue. Adaptation of SET has shown that the first stage should be performed immediately after sampling. Separation of fractions III and IV can be neglected, since the output of isotopes into the IV fraction is at the level of error detection. The most adequate version of SET for terrestrial vascular plants is the version using 20 mM Na 2 EDTA at the first stage. Isotope 90 Sr is most sensitive to the technique changes. Its distribution depends strongly on both the extractant used at stage 1 and duration of the first stage. Distribution of artificial radionuclides in the biomass of terrestrial vascular plants can vary from year to year and depends significantly on the age of the plant. Copyright © 2016 Elsevier Ltd. All rights reserved.

Meta-analyses and adaptive group sequential designs in the clinical development process.

PubMed

Jennison, Christopher; Turnbull, Bruce W

2005-01-01

The clinical development process can be viewed as a succession of trials, possibly overlapping in calendar time. The design of each trial may be influenced by results from previous studies and other currently proceeding trials, as well as by external information. Results from all of these trials must be considered together in order to assess the efficacy and safety of the proposed new treatment. Meta-analysis techniques provide a formal way of combining the information. We examine how such methods can be used in combining results from: (1) a collection of separate studies, (2) a sequence of studies in an organized development program, and (3) stages within a single study using a (possibly adaptive) group sequential design. We present two examples. The first example concerns the combining of results from a Phase IIb trial using several dose levels or treatment arms with those of the Phase III trial comparing the treatment selected in Phase IIb against a control This enables a "seamless transition" from Phase IIb to Phase III. The second example examines the use of combination tests to analyze data from an adaptive group sequential trial.

The NIMA Kinase Is Required To Execute Stage-Specific Mitotic Functions after Initiation of Mitosis

PubMed Central

Govindaraghavan, Meera; Lad, Alisha A.

2014-01-01

The G2-M transition in Aspergillus nidulans requires the NIMA kinase, the founding member of the Nek kinase family. Inactivation of NIMA results in a late G2 arrest, while overexpression of NIMA is sufficient to promote mitotic events independently of cell cycle phase. Endogenously tagged NIMA-GFP has dynamic mitotic localizations appearing first at the spindle pole body and then at nuclear pore complexes before transitioning to within nuclei and the mitotic spindle and back at the spindle pole bodies at mitotic exit, suggesting that it functions sequentially at these locations. Since NIMA is indispensable for mitotic entry, it has been difficult to determine the requirement of NIMA for subaspects of mitosis. We show here that when NIMA is partially inactivated, although mitosis can be initiated, a proportion of cells fail to successfully generate two daughter nuclei. We further define the mitotic defects to show that normal NIMA function is required for the formation of a bipolar spindle, nuclear pore complex disassembly, completion of chromatin segregation, and the normal structural rearrangements of the nuclear envelope required to generate two nuclei from one. In the remaining population of cells that enter mitosis with inadequate NIMA, two daughter nuclei are generated in a manner dependent on the spindle assembly checkpoint, indicating highly penetrant defects in mitotic progression without sufficient NIMA activity. This study shows that NIMA is required not only for mitotic entry but also sequentially for successful completion of stage-specific mitotic events. PMID:24186954

Two-Stage Variable Sample-Rate Conversion System

NASA Technical Reports Server (NTRS)

Tkacenko, Andre

2009-01-01

A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

Ethanol production from rape straw by a two-stage pretreatment under mild conditions.

PubMed

Romero, Inmaculada; López-Linares, Juan C; Delgado, Yaimé; Cara, Cristóbal; Castro, Eulogio

2015-08-01

The growing interest on rape oil as raw material for biodiesel production has resulted in an increasing availability of rape straw, an agricultural residue that is an attractive renewable source for the production of second-generation bioethanol. Pretreatment is one of the key steps in such a conversion process. In this work, a sequential two-stage pretreatment with dilute sulfuric acid (130 °C, 60 min, 2% w/v H2SO4) followed by H2O2 (1-5% w/v) in alkaline medium (NaOH) at low temperature (60, 90 °C) and at different pretreatment times (30-90 min) was investigated. The first-acid stage allows the solubilisation of hemicellulose fraction into fermentable sugars. The second-alkaline peroxide stage allows the delignification of the solid material whilst the cellulose remaining in rape straw turned highly digestible by cellulases. Simultaneous saccharification and fermentation with 15% (w/v) delignified substrate at 90 °C, 5% H2O2 for 60 min, led to a maximum ethanol production of 53 g/L and a yield of 85% of the theoretical.

Enzymatic synthesis of extra virgin olive oil based infant formula fat analogues containing ARA and DHA: one-stage and two-stage syntheses.

PubMed

Pande, Garima; Sabir, Jamal S M; Baeshen, Nabih A; Akoh, Casimir C

2013-11-06

Structured lipids (SLs) with high palmitic acid content at the sn-2 position enriched with arachidonic acid (ARA) and docosahexaenoic acid (DHA) were produced using extra virgin olive oil, tripalmitin, ARA and DHA single cell oil free fatty acids. Four types of SLs were synthesized using immobilized lipases, Novozym 435 and Lipozyme TL IM, based on one-stage (one-pot) and two-stage (sequential) syntheses. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, melting and crystallization profiles, tocopherols, and phenolic compounds. All the SLs had >50 mol % palmitic acid at the sn-2 position. The predominant TAGs in all SLs were PPO and OPO. The total tocopherol content of SL1-1, SL1-2, SL2-1, and SL2-2 were 70.46, 68.79, 79.64, and 79.31 μg/g, respectively. SL1-2 had the highest melting completion (42.0 °C) and crystallization onset (27.6 °C) temperatures. All the SLs produced in this study may be suitable as infant formula fat analogues.

The Recrystallization Behavior of Unalloyed Mg and a Mg-Al Alloy

NASA Astrophysics Data System (ADS)

Murphy, Aeriel D.; Allison, John E.

2018-02-01

The static recrystallization behavior of pure Mg and Mg-4Al was characterized over a range of annealing temperatures. The electron backscatter diffraction grain orientation spread technique was used to quantify the level of recrystallization at various annealing times. Recrystallization kinetics were characterized using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) relationship and it was found that two sequential annealing stages exist. Stage 1 involves heterogeneous nucleation of recrystallization in regions with a high stored energy, including twins and grain boundaries, and can be represented by an Avrami exponent of n 1 ranging from 0.35 to 0.6. During Stage 2, recrystallization occurred predominately in the interior of deformed grains with incomplete recrystallization generally observed even at annealing times in excess of two weeks. The second recrystallization stage exhibited a much lower Avrami exponent, n 2, ranging from 0.02 to 0.2. Increasing the starting grain size in the pure Mg condition led to a significant delay in recrystallization. The addition of Al had a minimal effect on the recrystallization kinetics of Mg.

Presence of angiotensin converting enzyme isoforms in larval lepidoptera (Spodoptera littoralis).

PubMed

Lemeire, E; Van Camp, J; Smagghe, G

2007-01-01

In this research the presence of angiotensin converting enzyme (ACE) in larvae of the lepidopteran Spodoptera littoralis was evaluated. Making use of the substrate Abz-FRK-(Dnp)P-OH and the specific inhibitor captopril at 10 microM, ACE activity was determined in a fluorescence assay for intact larvae, hemolymph, head, midgut and dorsal tissue. In dorsal tissue and hemolymph, ACE activity was highest. These data are consistent with a possible role for ACE in contractions of the dorsal vessel and metabolism of circulating peptide hormones in the hemolymph. After the presence of ACE was confirmed, a sequential procedure of anion exchange and size exclusion chromatography was applied to purify ACE from whole wandering larvae (last stage). With this procedure, three different ACE pools were collected that cleaved the fluorogenic substrate Abz-FRK-(Dnp)P-OH. Activity could be inhibited by a final concentration of 2.5 microM captopril. In addition, two out of three samples eluted at different salt concentration and thus ACE 1, 2 and 3 represent at least two different ACE isoforms. These data reveal that ACE is present in S. littoralis and that at least two out of three isolated ACE forms are truly isoforms.

Development and Validation of the Cognitive Behavioral Physical Activity Questionnaire.

PubMed

Schembre, Susan M; Durand, Casey P; Blissmer, Bryan J; Greene, Geoffrey W

2015-01-01

Develop and demonstrate preliminary validation of a brief questionnaire aimed at assessing social cognitive determinants of physical activity (PA) in a college population. Quantitative and observational. A midsized northeastern university. Convenience sample of 827 male and female college students age 18 to 24 years. International Physical Activity Questionnaire and a PA stage-of-change algorithm. A sequential process of survey development, including item generation and data reduction analyses by factor analysis, was followed with the goal of creating a parsimonious questionnaire. Structural equation modeling was used for confirmatory factor analysis and construct validation was confirmed against self-reported PA and stage of change. Validation analyses were replicated in a second, independent sample of 1032 college students. Fifteen items reflecting PA self-regulation, outcome expectations, and personal barriers explained 65% of the questionnaire data and explained 28.6% and 39.5% of the variance in total PA and moderate-to-vigorous-intensity PA, respectively. Scale scores were distinguishable across the stages of change. Findings were similar when the Cognitive Behavioral Physical Activity Questionnaire (CBPAQ) was tested in a similar and independent sample of college students (40%; R (2) moderate-to-vigorous-intensity PA = .40; p < .001). The CBPAQ successfully explains and predicts PA behavior in a college population, warranting its incorporation into future studies aiming at understanding and improving on PA behavior in college students.

Structural changes in cell wall pectins during strawberry fruit development.

PubMed

Paniagua, Candelas; Santiago-Doménech, Nieves; Kirby, Andrew R; Gunning, A Patrick; Morris, Victor J; Quesada, Miguel A; Matas, Antonio J; Mercado, José A

2017-09-01

Strawberry (Fragaria × anannasa Duch.) is one of the most important soft fruit. Rapid loss of firmness occurs during the ripening process, resulting in a short shelf life and high economic losses. To get insight into the role of pectin matrix in the softening process, cell walls from strawberry fruit at two developmental stages, unripe-green and ripe-red, were extracted and sequentially fractionated with different solvents to obtain fractions enriched in a specific component. The yield of cell wall material as well as the per fresh weight contents of the different fractions decreased in ripe fruit. The largest reduction was observed in the pectic fractions extracted with a chelating agent (trans-1,2- diaminocyclohexane-N,N,N'N'-tetraacetic acid, CDTA fraction) and those covalently bound to the wall (extracted with Na 2 CO 3 ). Uronic acid content of these two fractions also decreased significantly during ripening, but the amount of soluble pectins extracted with phenol:acetic acid:water (PAW) and water increased in ripe fruit. Fourier transform infrared spectroscopy of the different fractions showed that the degree of esterification decreased in CDTA pectins but increased in soluble fractions at ripen stage. The chromatographic analysis of pectin fractions by gel filtration revealed that CDTA, water and, mainly PAW polyuronides were depolymerised in ripe fruit. By contrast, the size of Na 2 CO 3 pectins was not modified. The nanostructural characteristics of CDTA and Na 2 CO 3 pectins were analysed by atomic force microscopy (AFM). Isolated pectic chains present in the CDTA fractions were significantly longer and more branched in samples from green fruit than those from red fruit. No differences in contour length were observed in Na 2 CO 3 strands between samples of both stages. However, the percentage of branched chains decreased from 19.7% in unripe samples to 3.4% in ripe fruit. The number of pectin aggregates was higher in green fruit samples of both fractions. These results show that the nanostructural complexity of pectins present in CDTA and Na 2 CO 3 fractions diminishes during fruit development, and this correlates with the solubilisation of pectins and the softening of the fruit. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Advanced neuroblastoma: improved response rate using a multiagent regimen (OPEC) including sequential cisplatin and VM-26.

PubMed

Shafford, E A; Rogers, D W; Pritchard, J

1984-07-01

Forty-two children, all over one year of age, were given vincristine, cyclophosphamide, and sequentially timed cisplatin and VM-26 (OPEC) or OPEC and doxorubicin (OPEC-D) as initial treatment for newly diagnosed stage III or IV neuroblastoma. Good partial response was achieved in 31 patients (74%) overall and in 28 (78%) of 36 patients whose treatment adhered to the chemotherapy protocol, compared with a 65% response rate achieved in a previous series of children treated with pulsed cyclophosphamide and vincristine with or without doxorubicin. Only six patients, including two of the six children whose treatment did not adhere to protocol, failed to respond, but there were five early deaths from treatment-related complications. Tumor response to OPEC, which was the less toxic of the two regimens, was at least as good as tumor response to OPEC-D. Cisplatin-induced morbidity was clinically significant in only one patient and was avoided in others by careful monitoring of glomerular filtration rate and hearing. Other centers should test the efficacy of OPEC or equivalent regimens in the treatment of advanced neuroblastoma.

Heavy metals and its chemical speciation in sewage sludge at different stages of processing.

PubMed

Tytła, Malwina; Widziewicz, Kamila; Zielewicz, Ewa

2016-01-01

The analysis of heavy metal concentrations and forms in sewage sludge constitutes an important issue in terms of both health and environmental hazards the metals pose. The total heavy metals concentration enables only the assessment of its contamination. Hence the knowledge of chemical forms is required to determine their environmental mobility and sludge final disposal. Heavy metals speciation was studied by using four-stage sequential extraction BCR (Community Bureau of Reference). This study was aimed at determining the total concentration of selected heavy metals (Zn, Cu, Ni, Pb, Cd, Cr and Hg) and their chemical forms (except for Hg) in sludge collected at different stages of its processing at two municipal Wastewater Treatment Plants in southern Poland. Metals contents in sludge samples were determined by using flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). This study shows that Zn and Cu appeared to be the most abundant in sludge, while Cd and Hg were in the lowest concentrations. The sewage sludge revealed the domination of immobile fractions over the mobile ones. The oxidizable and residual forms were dominant for all the heavy metals. There was also a significant difference in metals speciation between sludges of different origin which was probably due to differences in wastewater composition and processes occurring in biological stage of wastewater treatment. The results indicate a negligible capability of metals to migrate from sludge into the environment. Our research revealed a significant impact of thickening, stabilization and hygienization on the distribution of heavy metals in sludge and their mobility.

Biomolecular signatures of diabetic wound healing by structural mass spectrometry

PubMed Central

Hines, Kelly M.; Ashfaq, Samir; Davidson, Jeffrey M.; Opalenik, Susan R.; Wikswo, John P.; McLean, John A.

2013-01-01

Wound fluid is a complex biological sample containing byproducts associated with the wound repair process. Contemporary techniques, such as immunoblotting and enzyme immunoassays, require extensive sample manipulation and do not permit the simultaneous analysis of multiple classes of biomolecular species. Structural mass spectrometry, implemented as ion mobility-mass spectrometry (IM-MS), comprises two sequential, gas-phase dispersion techniques well suited for the study of complex biological samples due to its ability to separate and simultaneously analyze multiple classes of biomolecules. As a model of diabetic wound healing, polyvinyl alcohol (PVA) sponges were inserted subcutaneously into non-diabetic (control) and streptozotocin-induced diabetic rats to elicit a granulation tissue response and to collect acute wound fluid. Sponges were harvested at days 2 or 5 to capture different stages of the early wound healing process. Utilizing IM-MS, statistical analysis, and targeted ultra-performance liquid chromatography (UPLC) analysis, biomolecular signatures of diabetic wound healing have been identified. The protein S100-A8 was highly enriched in the wound fluids collected from day 2 diabetic rats. Lysophosphatidylcholine (20:4) and cholic acid also contributed significantly to the differences between diabetic and control groups. This report provides a generalized workflow for wound fluid analysis demonstrated with a diabetic rat model. PMID:23452326

Diagnostic accuracy of sequential co-registered PET+MR in comparison to PET/CT in local thoracic staging of malignant pleural mesothelioma.

PubMed

Martini, Katharina; Meier, Andreas; Opitz, Isabelle; Weder, Walter; Veit-Haibach, Patrick; Stahel, Rolf A; Frauenfelder, Thomas

2016-04-01

To investigate the diagnostic accuracy of sequential co-registered PET+MR (PET+MR) for local staging of malignant pleural mesothelioma (MPM) compared to PET/CT. In a prospective clinical trial 34 consecutive patients (median age 66 years; range 40-79 years; 1 female, 33 male) with known MPM, who underwent PET/CT and PET+MR exams for either staging or re-staging/follow-up were evaluated. Imaging was conducted using a tri-modality PET/CT-MR set-up (Discovery PET/CT 690, 3T Discovery MR 750w, both GE Healthcare, Waukesha, WI, USA). In 26 cases histopathology served as standard of reference. Two independent readers evaluated images for T and N stage, confidence level (sure to unsure; 1-3) and subjective overall image quality (very good to non-diagnostic; 1-4). Inter-observer agreement of T and N stages (Cohen's kappa) and interclass correlation coefficient (ICC) between PET/CT vs. PET+MR was calculated. Inter observer agreement for evaluation of T and N Stage in PET/CT images was excellent (k=0.844 and k=0.824, respectively), whereas PET+MR imaging showed substantial agreement in T and N stage (k=0.729 and k=0.691, respectively). The ICC of PET/CT vs. PET+MR for evaluation of both, T and N Stage, was excellent (ICC=0.951 and ICC=0.93, respectively). Diagnostic confidence was scored significantly higher in PET+MR compared to PET/CT (mean score=1.66 and 1.93, respectively; p=0.004). Image quality was diagnostic for all image series. Comparing pT and pN stage vs cT and cN stage (n=26 cases), both imaging modalities showed excellent agreement for T stage (ICCPET+MR=0.888 vs. ICCPET/CT=0.853, respectively) and substantial to moderate agreement for N stage (ICCPET+MR=0.683 vs. ICC=0.595PET/CT, respectively). Our findings suggest that diagnostic accuracy of PET+MR is comparable to PET/CT for local staging of MPM, whereas radiologists felt significantly more confident staging PET+MR compared to PET/CT images (p=0003), using dedicated sequences. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Continuous hydrogen and methane production from Agave tequilana bagasse hydrolysate by sequential process to maximize energy recovery efficiency.

PubMed

Montiel Corona, Virginia; Razo-Flores, Elías

2018-02-01

Continuous H 2 and CH 4 production in a two-stage process to increase energy recovery from agave bagasse enzymatic-hydrolysate was studied. In the first stage, the effect of organic loading rate (OLR) and stirring speed on volumetric hydrogen production rate (VHPR) was evaluated in a continuous stirred tank reactor (CSTR); by controlling the homoacetogenesis with the agitation speed and maintaining an OLR of 44 g COD/L-d, it was possible to reach a VHPR of 6 L H 2 /L-d, equivalent to 1.34 kJ/g bagasse. In the second stage, the effluent from CSTR was used as substrate to feed a UASB reactor for CH 4 production. Volumetric methane production rate (VMPR) of 6.4 L CH 4 /L-d was achieved with a high OLR (20 g COD/L-d) and short hydraulic retention time (HRT, 14 h), producing 225 mL CH 4 /g-bagasse equivalent to 7.88 kJ/g bagasse. The two-stage continuous process significantly increased energy conversion efficiency (56%) compared to one-stage hydrogen production (8.2%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimal Therapy Scheduling Based on a Pair of Collaterally Sensitive Drugs.

PubMed

Yoon, Nara; Vander Velde, Robert; Marusyk, Andriy; Scott, Jacob G

2018-05-07

Despite major strides in the treatment of cancer, the development of drug resistance remains a major hurdle. One strategy which has been proposed to address this is the sequential application of drug therapies where resistance to one drug induces sensitivity to another drug, a concept called collateral sensitivity. The optimal timing of drug switching in these situations, however, remains unknown. To study this, we developed a dynamical model of sequential therapy on heterogeneous tumors comprised of resistant and sensitive cells. A pair of drugs (DrugA, DrugB) are utilized and are periodically switched during therapy. Assuming resistant cells to one drug are collaterally sensitive to the opposing drug, we classified cancer cells into two groups, [Formula: see text] and [Formula: see text], each of which is a subpopulation of cells resistant to the indicated drug and concurrently sensitive to the other, and we subsequently explored the resulting population dynamics. Specifically, based on a system of ordinary differential equations for [Formula: see text] and [Formula: see text], we determined that the optimal treatment strategy consists of two stages: an initial stage in which a chosen effective drug is utilized until a specific time point, T, and a second stage in which drugs are switched repeatedly, during which each drug is used for a relative duration (i.e., [Formula: see text]-long for DrugA and [Formula: see text]-long for DrugB with [Formula: see text] and [Formula: see text]). We prove that the optimal duration of the initial stage, in which the first drug is administered, T, is shorter than the period in which it remains effective in decreasing the total population, contrary to current clinical intuition. We further analyzed the relationship between population makeup, [Formula: see text], and the effect of each drug. We determine a critical ratio, which we term [Formula: see text], at which the two drugs are equally effective. As the first stage of the optimal strategy is applied, [Formula: see text] changes monotonically to [Formula: see text] and then, during the second stage, remains at [Formula: see text] thereafter. Beyond our analytic results, we explored an individual-based stochastic model and presented the distribution of extinction times for the classes of solutions found. Taken together, our results suggest opportunities to improve therapy scheduling in clinical oncology.

Parallelization of Finite Element Analysis Codes Using Heterogeneous Distributed Computing

NASA Technical Reports Server (NTRS)

Ozguner, Fusun

1996-01-01

Performance gains in computer design are quickly consumed as users seek to analyze larger problems to a higher degree of accuracy. Innovative computational methods, such as parallel and distributed computing, seek to multiply the power of existing hardware technology to satisfy the computational demands of large applications. In the early stages of this project, experiments were performed using two large, coarse-grained applications, CSTEM and METCAN. These applications were parallelized on an Intel iPSC/860 hypercube. It was found that the overall speedup was very low, due to large, inherently sequential code segments present in the applications. The overall execution time T(sub par), of the application is dependent on these sequential segments. If these segments make up a significant fraction of the overall code, the application will have a poor speedup measure.

Mercury Speciation by X-ray Absorption Fine Structure Spectroscopy and Sequential Chemical Extractions: A Comparison of Speciation Methods

USGS Publications Warehouse

Kim, C.S.; Bloom, N.S.; Rytuba, J.J.; Brown, Gordon E.

2003-01-01

Determining the chemical speciation of mercury in contaminated mining and industrial environments is essential for predicting its solubility, transport behavior, and potential bioavailability as well as for designing effective remediation strategies. In this study, two techniques for determining Hg speciation-X-ray absorption fine structure (XAFS) spectroscopy and sequential chemical extractions (SCE)-are independently applied to a set of samples with Hg concentrations ranging from 132 to 7539 mg/kg to determine if the two techniques provide comparable Hg speciation results. Generally, the proportions of insoluble HgS (cinnabar, metacinnabar) and HgSe identified by XAFS correlate well with the proportion of Hg removed in the aqua regia extraction demonstrated to remove HgS and HgSe. Statistically significant (> 10%) differences are observed however in samples containing more soluble Hg-containing phases (HgCl2, HgO, Hg3S2O 4). Such differences may be related to matrix, particle size, or crystallinity effects, which could affect the apparent solubility of Hg phases present. In more highly concentrated samples, microscopy techniques can help characterize the Hg-bearing species in complex multiphase natural samples.

Human embryonic stem cell lines derived from single blastomeres of two 4-cell stage embryos

PubMed Central

Geens, Mieke; Mateizel, Ileana; Sermon, Karen; De Rycke, Martine; Spits, Claudia; Cauffman, Greet; Devroey, Paul; Tournaye, Herman; Liebaers, Inge; Van de Velde, Hilde

2009-01-01

BACKGROUND Recently, we demonstrated that single blastomeres of a 4-cell stage human embryo are able to develop into blastocysts with inner cell mass and trophectoderm. To further investigate potency at the 4-cell stage, we aimed to derive pluripotent human embryonic stem cells (hESC) from single blastomeres. METHODS Four 4-cell stage embryos were split on Day 2 of preimplantation development and the 16 blastomeres were individually cultured in sequential medium. On Day 3 or 4, the blastomere-derived embryos were plated on inactivated mouse embryonic fibroblasts (MEFs). RESULTS Ten out of sixteen blastomere-derived morulae attached to the MEFs, and two produced an outgrowth. They were mechanically passaged onto fresh MEFs as described for blastocyst ICM-derived hESC, and shown to express the typical stemness markers by immunocytochemistry and/or RT–PCR. In vivo pluripotency was confirmed by the presence of all three germ layers in the teratoma obtained after injection in immunodeficient mice. The first hESC line displays a mosaic normal/abnormal 46, XX, dup(7)(q33qter), del(18)(q23qter) karyotype. The second hESC line displays a normal 46, XY karyotype. CONCLUSION We report the successful derivation and characterization of two hESC lines from single blastomeres of four split 4-cell stage human embryos. These two hESC lines were derived from distinct embryos, proving that at least one of the 4-cell stage blastomeres is pluripotent. PMID:19633307

A Bayesian sequential design with adaptive randomization for 2-sided hypothesis test.

PubMed

Yu, Qingzhao; Zhu, Lin; Zhu, Han

2017-11-01

Bayesian sequential and adaptive randomization designs are gaining popularity in clinical trials thanks to their potentials to reduce the number of required participants and save resources. We propose a Bayesian sequential design with adaptive randomization rates so as to more efficiently attribute newly recruited patients to different treatment arms. In this paper, we consider 2-arm clinical trials. Patients are allocated to the 2 arms with a randomization rate to achieve minimum variance for the test statistic. Algorithms are presented to calculate the optimal randomization rate, critical values, and power for the proposed design. Sensitivity analysis is implemented to check the influence on design by changing the prior distributions. Simulation studies are applied to compare the proposed method and traditional methods in terms of power and actual sample sizes. Simulations show that, when total sample size is fixed, the proposed design can obtain greater power and/or cost smaller actual sample size than the traditional Bayesian sequential design. Finally, we apply the proposed method to a real data set and compare the results with the Bayesian sequential design without adaptive randomization in terms of sample sizes. The proposed method can further reduce required sample size. Copyright © 2017 John Wiley & Sons, Ltd.

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...

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.

Sequential anaerobic/aerobic digestion of waste activated sludge: analysis of the process performance and kinetic study.

PubMed

Tomei, M Concetta; Rita, Sara; Mininni, Giuseppe

2011-12-15

Sequential anaerobic-aerobic digestion was applied to waste activated sludge (WAS) of a full scale wastewater treatment plant. The study was performed with the objective of testing the sequential digestion process on WAS, which is characterized by worse digestibility in comparison with the mixed sludge. Process performance was evaluated in terms of biogas production, volatile solids (VS) and COD reduction, and patterns of biopolymers (proteins and polysaccharides) in the subsequent digestion stages. VS removal efficiency of 40%, in the anaerobic phase, and an additional removal of 26%, in the aerobic one, were observed. For total COD removal efficiencies of 35% and 25% for anaerobic and aerobic stage respectively, were obtained. Kinetics of VS degradation process was analyzed by assuming a first order equation with respect to VS concentration. Evaluated kinetic parameters were 0.44 ± 0.20 d(-1) and 0.25 ± 0.15 d(-1) for the anaerobic stage and aerobic stage, respectively. With regard to biopolymers, in the anaerobic phase the content of proteins and polysaccharides increased to 50% and 69%, respectively, whereas in the subsequent aerobic phase, a decrease of 71% for proteins and 67% for polysaccharides was observed. The average specific biogas production 0.74 m(3)/(kg VS destroyed), was in the range of values reported in the specialized literature for conventional anaerobic mesophilic WAS digestion. Copyright © 2011 Elsevier B.V. All rights reserved.

Studying the Effect of Deposition Conditions on the Performance and Reliability of MEMS Gas Sensors

PubMed Central

Sadek, Khaled; Moussa, Walied

2007-01-01

In this paper, the reliability of a micro-electro-mechanical system (MEMS)-based gas sensor has been investigated using Three Dimensional (3D) coupled multiphysics Finite Element (FE) analysis. The coupled field analysis involved a two-way sequential electrothermal fields coupling and a one-way sequential thermal-structural fields coupling. An automated substructuring code was developed to reduce the computational cost involved in simulating this complicated coupled multiphysics FE analysis by up to 76 percent. The substructured multiphysics model was then used to conduct a parametric study of the MEMS-based gas sensor performance in response to the variations expected in the thermal and mechanical characteristics of thin films layers composing the sensing MEMS device generated at various stages of the microfabrication process. Whenever possible, the appropriate deposition variables were correlated in the current work to the design parameters, with good accuracy, for optimum operation conditions of the gas sensor. This is used to establish a set of design rules, using linear and nonlinear empirical relations, which can be utilized in real-time at the design and development decision-making stages of similar gas sensors to enable the microfabrication of these sensors with reliable operation.

Sequential Dictionary Learning From Correlated Data: Application to fMRI Data Analysis.

PubMed

Seghouane, Abd-Krim; Iqbal, Asif

2017-03-22

Sequential dictionary learning via the K-SVD algorithm has been revealed as a successful alternative to conventional data driven methods such as independent component analysis (ICA) for functional magnetic resonance imaging (fMRI) data analysis. fMRI datasets are however structured data matrices with notions of spatio-temporal correlation and temporal smoothness. This prior information has not been included in the K-SVD algorithm when applied to fMRI data analysis. In this paper we propose three variants of the K-SVD algorithm dedicated to fMRI data analysis by accounting for this prior information. The proposed algorithms differ from the K-SVD in their sparse coding and dictionary update stages. The first two algorithms account for the known correlation structure in the fMRI data by using the squared Q, R-norm instead of the Frobenius norm for matrix approximation. The third and last algorithm account for both the known correlation structure in the fMRI data and the temporal smoothness. The temporal smoothness is incorporated in the dictionary update stage via regularization of the dictionary atoms obtained with penalization. The performance of the proposed dictionary learning algorithms are illustrated through simulations and applications on real fMRI data.

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.

In situ analysis of chemical components induced by steaming between fresh ginseng, steamed ginseng, and red ginseng.

PubMed

In, Gyo; Ahn, Nam-Geun; Bae, Bong-Seok; Lee, Myoung-Woo; Park, Hee-Won; Jang, Kyoung Hwa; Cho, Byung-Goo; Han, Chang Kyun; Park, Chae Kyu; Kwak, Yi-Seong

2017-07-01

The chemical constituents of Panax ginseng are changed by processing methods such as steaming or sun drying. In the present study, the chemical change of Panax ginseng induced by steaming was monitored in situ . Samples were separated from the same ginseng root by incision during the steaming process, for in situ monitoring. Sampling was sequentially performed in three stages; FG (fresh ginseng) → SG (steamed ginseng) → RG (red ginseng) and 60 samples were prepared and freeze dried. The samples were then analyzed to determine 43 constituents among three stages of P. ginseng . The results showed that six malonyl-ginsenoside (Rg1, Rb1, Rb3, Rc, Rd, Rb2) and 15 amino acids were decreased in concentration during the steaming process. In contrast, ginsenoside-Rh1, 20( S )-Rg2, 20( S, R )-Rg3 and Maillard reaction product such as AF (arginine-fructose), AFG (arginine-fructose-glucose), and maltol were newly generated or their concentrations were increased. This study elucidates the dynamic changes in the chemical components of P. ginseng when the steaming process was induced. These results are thought to be helpful for quality control and standardization of herbal drugs using P. ginseng and they also provide a scientific basis for pharmacological research of processed ginseng (Red ginseng).

Sequential elution process

DOEpatents

Kingsley, I.S.

1987-01-06

A process and apparatus are disclosed for the separation of complex mixtures of carbonaceous material by sequential elution with successively stronger solvents. In the process, a column containing glass beads is maintained in a fluidized state by a rapidly flowing stream of a weak solvent, and the sample is injected into this flowing stream such that a portion of the sample is dissolved therein and the remainder of the sample is precipitated therein and collected as a uniform deposit on the glass beads. Successively stronger solvents are then passed through the column to sequentially elute less soluble materials. 1 fig.

Re-Examining Group Development in Adventure Therapy Groups.

ERIC Educational Resources Information Center

DeGraaf, Don; Ashby, Jeff

1998-01-01

Small-group development is an important aspect of adventure therapy. Supplementing knowledge of sequential stages of group development with knowledge concerning within-stage nonsequential development yields a richer understanding of groups. Integrating elements of the individual counseling relationship (working alliance, transference, and real…

Graphic and movie illustrations of human prenatal development and their application to embryological education based on the human embryo specimens in the Kyoto collection.

PubMed

Yamada, Shigehito; Uwabe, Chigako; Nakatsu-Komatsu, Tomoko; Minekura, Yutaka; Iwakura, Masaji; Motoki, Tamaki; Nishimiya, Kazuhiko; Iiyama, Masaaki; Kakusho, Koh; Minoh, Michihiko; Mizuta, Shinobu; Matsuda, Tetsuya; Matsuda, Yoshimasa; Haishi, Tomoyuki; Kose, Katsumi; Fujii, Shingo; Shiota, Kohei

2006-02-01

Morphogenesis in the developing embryo takes place in three dimensions, and in addition, the dimension of time is another important factor in development. Therefore, the presentation of sequential morphological changes occurring in the embryo (4D visualization) is essential for understanding the complex morphogenetic events and the underlying mechanisms. Until recently, 3D visualization of embryonic structures was possible only by reconstruction from serial histological sections, which was tedious and time-consuming. During the past two decades, 3D imaging techniques have made significant advances thanks to the progress in imaging and computer technologies, computer graphics, and other related techniques. Such novel tools have enabled precise visualization of the 3D topology of embryonic structures and to demonstrate spatiotemporal 4D sequences of organogenesis. Here, we describe a project in which staged human embryos are imaged by the magnetic resonance (MR) microscope, and 3D images of embryos and their organs at each developmental stage were reconstructed based on the MR data, with the aid of computer graphics techniques. On the basis of the 3D models of staged human embryos, we constructed a data set of 3D images of human embryos and made movies to illustrate the sequential process of human morphogenesis. Furthermore, a computer-based self-learning program of human embryology is being developed for educational purposes, using the photographs, histological sections, MR images, and 3D models of staged human embryos. Copyright 2005 Wiley-Liss, Inc.

Comparison between sequentional treatment with diode and alexandrite lasers versus alexandrite laser alone in the treatment of hirsutism.

PubMed

Nilforoushzadeh, Mohammad Ali; Naieni, Farahnaz Fatemi; Siadat, Amir Hossein; Rad, Leila

2011-11-01

Laser systems that are commonly used for the treatment of hirsutism include the ruby laser (694 nm), the diode laser (800 nm), the alexandrite laser (755 nm) and the Nd:YAG laser (1084 nm). The diode laser and alexandrite laser are considered effective in treatment of hirsutism in dark-skinned patients. The response of hairs to these laser systems is variable and not complete. In this study, we compared the efficacy of these two laser systems for permanent hair removal. This was a randomized, controlled clinical trial that was performed with women of the age range 15-45 years old. After obtaining informed consent, the samples were randomized into two groups using random allocation software. The first group was treated with alexandrite laser alone (four sessions, two months apart). The second group was treated sequentially with diode laser for the first two sessions and alexandrite laser for the next two sessions. Overall, 111 patients (57 patients in the alexandrite laser group and 54 patients in the sequential diode-alexandrite laser group) were evaluated. There was no significant difference regarding mean of hair reduction between the two groups during the courses of treatment. Except for the first session, there was no significant difference regarding percent of patient satisfaction between the two groups (P value >0.05). Comparison between the two groups showed no significant difference one month, three months and six months after the last treatment (P value >0.05). Regarding the results of our study, there is no significant difference between sequential treatment with diode and alexandrite lasers versus alexandrite laser alone in the treatment of hirsutism. We suggest that in further studies, the efficacy of sequential treatment with other laser systems is evaluated against single treatment methods.

SEMIPARAMETRIC ADDITIVE RISKS REGRESSION FOR TWO-STAGE DESIGN SURVIVAL STUDIES

PubMed Central

Li, Gang; Wu, Tong Tong

2011-01-01

In this article we study a semiparametric additive risks model (McKeague and Sasieni (1994)) for two-stage design survival data where accurate information is available only on second stage subjects, a subset of the first stage study. We derive two-stage estimators by combining data from both stages. Large sample inferences are developed. As a by-product, we also obtain asymptotic properties of the single stage estimators of McKeague and Sasieni (1994) when the semiparametric additive risks model is misspecified. The proposed two-stage estimators are shown to be asymptotically more efficient than the second stage estimators. They also demonstrate smaller bias and variance for finite samples. The developed methods are illustrated using small intestine cancer data from the SEER (Surveillance, Epidemiology, and End Results) Program. PMID:21931467

Alternatives to the sequential lineup: the importance of controlling the pictures.

PubMed

Lindsay, R C; Bellinger, K

1999-06-01

Because sequential lineups reduce false-positive choices, their use has been recommended (R. C. L. Lindsay, 1999; R. C. L. Lindsay & G. L. Wells, 1985). Blind testing is included in the recommended procedures. Police, concerned about blind testing, devised alternative procedures, including self-administered sequential lineups, to reduce use of relative judgments (G. L. Wells, 1984) while permitting the investigating officer to conduct the procedure. Identification data from undergraduates exposed to a staged crime (N = 165) demonstrated that 4 alternative identification procedures tested were less effective than the original sequential lineup. Allowing witnesses to control the photographs resulted in higher rates of false-positive identification. Self-reports of using relative judgments were shown to be postdictive of decision accuracy.

Entomophytophagy ('Sequential Predatory, then Phytophagous Behaviour') in an Indian Braconid 'Parasitoid' Wasp (Hymenoptera): Specialized Larval Morphology, Biology and Description of a New Species.

PubMed

Ranjith, A P; Quicke, Donald L J; Saleem, U K A; Butcher, Buntika A; Zaldívar-Riverón, Alejandro; Nasser, M

2016-01-01

The vast majority of braconid wasps are parasitoids of other insects. Although a few cases of pure phytophagy (primary gall production and seed predation) are known, no previous entomophytophagous species (i.e. ones that display entomophagy and phytophagy sequentially), has been discovered among braconids. We describe the detailed biology and specialized larval morphology for the first confirmed entomophytophagous braconid species. Leaf galls on Garuga pinnata Roxb. (Burseraceae) in India, induced by the psyllid, Phacopteron lentiginosum Buckton (Hemiptera: Psylloidea, Phacopteronidae) were sampled throughout a period of several months and found to suffer a high level of attack by a new species Bracon garugaphagae Ranjith & Quicke which is here described and illustrated. The wasps oviposit singly into the galls without paralysing the psyllids. The larvae first attack psyllid nymphs which they seek out within the gall, kill them with a single bite and consume them. Unique dorsal abdominal tubercles, with eversible tips present on the abdominal segments of the larvae that are used to help maintain larval position while feeding, are illustrated. After consuming all available prey, the larvae continue feeding on gall tissue until mature enough to spin cocoons and pupate. The new species illustrates, for the first time, a possible intermediate stage in the evolution of pure phytophagy within the Braconidae. Interestingly, the two unrelated seed predator Bracon species are also associated with Burseraceae, perhaps indicating that this plant family is particularly suited as a food for braconine wasps.

A Method To Determine the Kinetics of Solute Mixing in Liquid/Liquid Formulation Dual-Chamber Syringes.

PubMed

Werk, Tobias; Mahler, Hanns-Christian; Ludwig, Imke Sonja; Luemkemann, Joerg; Huwyler, Joerg; Hafner, Mathias

Dual-chamber syringes were originally designed to separate a solid substance and its diluent. However, they can also be used to separate liquid formulations of two individual drug products, which cannot be co-formulated due to technical or regulatory issues. A liquid/liquid dual-chamber syringe can be designed to achieve homogenization and mixing of both solutions prior to administration, or it can be used to sequentially inject both solutions. While sequential injection can be easily achieved by a dual-chamber syringe with a bypass located at the needle end of the syringe barrel, mixing of the two fluids may provide more challenges. Within this study, the mixing behavior of surrogate solutions in different dual-chamber syringes is assessed. Furthermore, the influence of parameters such as injection angle, injection speed, agitation, and sample viscosity were studied. It was noted that mixing was poor for the commercial dual-chamber syringes (with a bypass designed as a longitudinal ridge) when the two liquids significantly differ in their physical properties (viscosity, density). However, an optimized dual-chamber syringe design with multiple bypass channels resulted in improved mixing of liquids. Dual-chamber syringes were originally designed to separate a solid substance and its diluent. However, they can also be used to separate liquid formulations of two individual drug products. A liquid/liquid dual-chamber syringe can be designed to achieve homogenization and mixing of both solutions prior to administration, or it can be used to sequentially inject both solutions. While sequential injection can be easily achieved by a dual-chamber syringe with a bypass located at the needle end of the syringe barrel, mixing of the two fluids may provide more challenges. Within this study, the mixing behavior of surrogate solutions in different dual-chamber syringes is assessed. Furthermore, the influence of parameters such as injection angle, injection speed, agitation, and sample viscosity were studied. It was noted that mixing was poor for the commercially available dual-chamber syringes when the two liquids significantly differ in viscosity and density. However, an optimized dual-chamber syringe design resulted in improved mixing of liquids. © PDA, Inc. 2017.

Evaluating CO2 mineralization capacity of sedimentary rock Using BCR sequential extraction procedures

NASA Astrophysics Data System (ADS)

Yang, Gang-Ting; Yu, Chi-Wen; Yang, Hsiao-Ming; Chiao, Chung-Hui; Yang, Ming-Wei

2015-04-01

To relief the high concentration of carbon dioxide in the atmosphere, carbon capture and storage (CCS) is gradually becoming an important concept to reduce greenhouse gas emissions. In IPCC Special Report on CCS, the storage mechanisms for geological formations are categorized into structural/stratigraphic, hydrodynamic and geochemical trappings. Geochemical trapping is considered as a storage mechanism, which can further increase storage capacity, effectiveness and security in terms of permanent CO2 sequestration. The injected CO2 can have geochemical interactions with pore fluid and reservoir rocks and transform into minerals. It is important to evaluate the capacity of reservoir rock for sequestrating CO2. In this study, sedimentary rock samples were collected from a 2-km-deep well in Midwestern Taiwan; and, the BCR sequential extraction experiments developed by European Union Measurement and Testing Programme were conducted. BCR was designed for extracting three major phases from soil, including exchangeable phase and carbonates (the first stage), reducible phase (the second stage) and oxidizable phase (the third stage). The chemistry of extracted solutions and rock residues were measured with ICP-MS and XRF, respectively. According to the results of XRF, considerable amounts of calcium and iron can be extracted by BCR procedures but other cations are negligible. In general, shale has a higher capacity of CO2 sequestration than sandstone. The first stage of extraction can release about 6 (sandstone) to 18.5 (shale) g of calcium from 1 kg rock, which are equivalent to 6.6 and 20.4 g CO2/kg rock, respectively. In the second stage extraction, 0.71 (sandstone) to 1.38 (shale) g/kg rock of iron can be released and can mineralized 0.56 to 1.08 g CO2/kg rock. However, there are no considerable cations extracted in the third stage of BCR as shown by the XRF analysis. In addition, the results of ICP-MS show that Mg can be released in the order of 10-3 g from 1 kg rock while cations of Zn, Co, Ni, Cd, Pb, Cu and Ba are in the order of 10-4 g.

Sequential therapy in advanced non-small-cell lung cancer with weekly paclitaxel followed by cisplatin-gemcitabine-vinorelbine. A phase II study.

PubMed

Feliu, J; Martin, G; Lizón, J; Chacón, J I; Dorta, J; de Castro, J; Rodríguez, A; Sánchez Heras, B; Torrego, J C; Espinosa, E; González Barón, M

2001-10-01

New effective therapies are needed to improve the outcome of patients with advanced non-small-cell lung cancer (NSCLC). The aim of this study was to assess the response rate and survival obtained with a sequential regimen of chemotherapy. Patients with newly diagnosed stage IIIb-IV NSCLC were included. They all had measurable disease and a good performance status (0-2 in the Eastern Cooperative Oncology Group scale). Chemotherapy consisted of weekly paclitaxel 150 mg/m2 x 6, followed two weeks later by cisplatin 100 mg/m2 on day 1, gemcitabine 1,000 mg/m2 on days 1 and 14, and vinorelbine 25 mg/m2 on days 1 and 14 (CGV). CGV was administered every 28 days for a maximum of six courses. Fifty-two patients were included, 19 (37%) with stage IIIb and 33 (63%) with stage IV disease. After therapy with weekly paclitaxel. 29 partial responses were obtained (56%, 95% confidence interval (95% CI): 38%-67%), whereas 15 patients had stable disease (29%) and eight had a progression (15%). After CGV, there were four complete remissions (8%) and 24 partial responses (46%), for an overall response rate of 54% (95% CI: 37%-65%). Eight patients had stable disease (15%) and 16 had a progression (31%). No patient progressing after paclitaxel responded to CGV, whereas 5 out of 15 patients with stable disease reached a partial response with CGV (33%). On the contrary, 5 out of 29 patients with a partial response to paclitaxel progressed after CGV (17%). Median survival has not been reached after a median follow-up of 14 months. Median time to progression was nine months. Fifty-six percent of patients remain alive at one year. Two hundred eighty-nine courses of paclitaxel and 170 of CGV were given, with a median of 5.5 and 3.4 per patient, respectively (ranges 2-6 and 0-6. respectively). WHO grade 3-4 toxicities for paclitaxel were: neutropenia in two patients (4/) and peripheral neuropathy in five (10%). Two patients had allergic reactions requiring paclitaxel withdrawal, whereas four (8%) had hyperglycemia >250 mg/ml. Grade 3-4 toxicities for CGV were: neutropenia in ten patients (20%), peripheral neuropathy in six (12%), anemia in four (8%), nausea/vomiting in five (10%). thrombocytopenia in two (4%), and fatigue in four (8%). Our results suggest that sequential chemotherapy with weekly paclitaxel followed by CGV is highly active in patients with advanced NSCLC and has an acceptable toxicity. This schedule deserves further evaluation in a phase III study.

Variable aperture-based ptychographical iterative engine method.

PubMed

Sun, Aihui; Kong, Yan; Meng, Xin; He, Xiaoliang; Du, Ruijun; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

2018-02-01

A variable aperture-based ptychographical iterative engine (vaPIE) is demonstrated both numerically and experimentally to reconstruct the sample phase and amplitude rapidly. By adjusting the size of a tiny aperture under the illumination of a parallel light beam to change the illumination on the sample step by step and recording the corresponding diffraction patterns sequentially, both the sample phase and amplitude can be faithfully reconstructed with a modified ptychographical iterative engine (PIE) algorithm. Since many fewer diffraction patterns are required than in common PIE and the shape, the size, and the position of the aperture need not to be known exactly, this proposed vaPIE method remarkably reduces the data acquisition time and makes PIE less dependent on the mechanical accuracy of the translation stage; therefore, the proposed technique can be potentially applied for various scientific researches. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Effect of two-stage sintering on dielectric properties of BaTi0.9Zr0.1O3 ceramics

NASA Astrophysics Data System (ADS)

Rani, Rekha; Rani, Renu; Kumar, Parveen; Juneja, J. K.; Raina, K. K.; Prakash, Chandra

2011-09-01

The effect of two-stage sintering on the dielectric properties of BaTi0.9Zr0.1O3 ceramics prepared by solid state route was investigated and is presented here. It has been found that under suitable two-stage sintering conditions, dense BaTi0.9Zr0.1O3 ceramics with improved electrical properties can be synthesized. The density was found to have a value of 5.49 g cc-1 for normally sintered samples, whereas in the case of the two-stage sintered sample it was 5.85 g cc-1. Dielectric measurements were done as a function of frequency and temperature. A small decrease in the Curie temperature was observed with modification in dielectric loss for two-stage sintered ceramic samples.

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…

Outcome and cost analysis of bilateral sequential same-day cartilage tympanoplasty compared with bilateral staged tympanoplasty.

PubMed

Olusesi, A D; Oyeniran, O

2017-05-01

Few studies have compared bilateral same-day with staged tympanoplasty using cartilage graft materials. A prospective randomised observational study was performed of 38 chronic suppurative otitis media patients (76 ears) who were assigned to undergo bilateral sequential same-day tympanoplasty (18 patients, 36 ears) or bilateral sequential tympanoplasty performed 3 months apart (20 patients, 40 ears). Disease duration, intra-operative findings, combined duration of surgery, post-operative graft appearance at 6 weeks, post-operative complications, re-do rate and relative cost of surgery were recorded. Tympanic membrane perforations were predominantly subtotal (p = 0.36, odds ratio = 0.75). Most grafts were harvested from the conchal cartilage and fewer from the tragus (p = 0.59, odds ratio = 1.016). Types of complication, post-operative hearing gain and revision rates were similar in both patient groups. Surgical outcomes are not significantly different for same-day and bilateral cartilage tympanoplasty, but same-day surgery has the added benefit of a lower cost.

[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) .

Global geomorphology: Report of Working Group Number 1

NASA Technical Reports Server (NTRS)

Douglas, I.

1985-01-01

Remote sensing was considered invaluable for seeing landforms in their regional context and in relationship to each other. Sequential images, such as those available from LANDSAT orbits provide a means of detecting landform change and the operation of large scale processes, such as major floods in semiarid regions. The use of remote sensing falls into two broad stages: (1) the characterization or accurate description of the features of the Earth's surface; and (2) the study of landform evolution. Recommendations for future research are made.

Simplified pupal surveys of Aedes aegypti (L.) for entomologic surveillance and dengue control.

PubMed

Barrera, Roberto

2009-07-01

Pupal surveys of Aedes aegypti (L.) are useful indicators of risk for dengue transmission, although sample sizes for reliable estimations can be large. This study explores two methods for making pupal surveys more practical yet reliable and used data from 10 pupal surveys conducted in Puerto Rico during 2004-2008. The number of pupae per person for each sampling followed a negative binomial distribution, thus showing aggregation. One method found a common aggregation parameter (k) for the negative binomial distribution, a finding that enabled the application of a sequential sampling method requiring few samples to determine whether the number of pupae/person was above a vector density threshold for dengue transmission. A second approach used the finding that the mean number of pupae/person is correlated with the proportion of pupa-infested households and calculated equivalent threshold proportions of pupa-positive households. A sequential sampling program was also developed for this method to determine whether observed proportions of infested households were above threshold levels. These methods can be used to validate entomological thresholds for dengue transmission.

The Actor and His Body.

ERIC Educational Resources Information Center

Rubin, Lucille S., Ed.

Fourteen brief articles deal with training actors to use their bodies effectively on stage. The articles discuss the following topics: the concept of succession-sequential movement (movement that passes through the body joint by joint); learning physical action through staged fight sequences; techniques of empty-handed combat; protecting students…

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry

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

Tfaily, Malak M.; Chu, Rosalie K.; Toyoda, Jason

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO2. The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition.more » In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H2O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl3) mixture, or acetonitrile (ACN) and CHCl3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types.« less

Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry.

PubMed

Tfaily, Malak M; Chu, Rosalie K; Toyoda, Jason; Tolić, Nikola; Robinson, Errol W; Paša-Tolić, Ljiljana; Hess, Nancy J

2017-06-15

A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO 2 . The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition. In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H 2 O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl 3 ) mixture, or acetonitrile (ACN) and CHCl 3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample is used for each solvent type. Furthermore, a comparison of SOM composition from the different sample types revealed that our sequential protocol allows for ecosystem comparisons based on the diversity of compounds present, which in turn could provide new insights about source and processing of organic compounds in different soil and sediment types. Copyright © 2017 Elsevier B.V. All rights reserved.

Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

PubMed

Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

2015-03-01

This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

Advanced Turbo-Charging Research and Development

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

None

2008-02-27

The objective of this project is to conduct analysis, design, procurement and test of a high pressure ratio, wide flow range, and high EGR system with two stages of turbocharging. The system needs to meet the stringent 2010MY emissions regulations at 20% + better fuel economy than its nearest gasoline competitor while allowing equivalent vehicle launch characteristics and higher torque capability than its nearest gasoline competitor. The system will also need to meet light truck/ SUV life requirements, which will require validation or development of components traditionally used only in passenger car applications. The conceived system is termed 'seriessequential turbocharger'more » because the turbocharger system operates in series at appropriate times and also sequentially when required. This is accomplished using intelligent design and control of flow passages and valves. Components of the seriessequential system will also be applicable to parallel-sequential systems which are also expected to be in use for future light truck/SUV applications.« less

Contrasting Effects of Cattle Manure Applications and Root-Induced Changes on Heavy Metal Dynamics in the Rhizosphere of Soybean in an Acidic Haplic Fluvisol: A Chronological Pot Experiment.

PubMed

Chu, Qingnan; Sha, Zhimin; Osaki, Mitsuru; Watanabe, Toshihiro

2017-04-19

To characterize the dynamic mobilization of heavy metals (HM) in a crop-soil system affected by cattle manure (CM) application, soybean [Glycine max L. Merr. cv. Toyoharuka] crops were exposed in a chronological pot experiment to three CM application rates and sampled at two vegetative stages and two reproductive stages. A sequential extraction procedure for metal fractionation, soil pH, microbial activity, and plant HM uptake was determined. In non-rhizopshere soil, with CM application a liming effect was detected, and increased microbial activity was detected at the reproductive stage. CM application shifted Cd from available state to oxide-bound pool in non-rhizosphere soil; however, shifts in Cd from an oxide-bound pool to the available state were observed in rhizosphere soil. CM application stabilized the available Zn and Pb to oxide-bound Zn and organic-bound Pb in both non-rhizosphere and rhizosphere soils, and the stabilizing degree increased with higher CM application rates. The promoted Zn immobilization in the rhizosphere was due to the liming effects induced by added CM that counteracted the root-induced acidification. On the basis of a stepwise multiple regression analysis, the shift of Cd and Pb fractionation was mainly related to microbial activity. Adding manure inhibited Zn and Pb uptake but promoted Cd uptake by soybean, and a greater influence was detected at the reproductive stage, at which CM application increased the root Cd-absorbing power but did not significantly affect the Zn- and Pb-absorbing powers. In an agricultural context, long-term CM application, even at the recommended rate of 10.13 Mg ha -1 , may cause a soybean Zn deficiency and high Pb accumulation in Haplic Fluvisols, although CM is often considered as an environmentally friendly fertilizer.

The longitudinal sagittal growth changes of maxilla and mandible according to quantitative cervical vertebral maturation.

PubMed

Chen, Lili; Lin, Jiuxiang; Xu, Tianmin; Long, Xiaosi

2009-04-01

To investigate the longitudinal sagittal growth changes of maxilla and mandible according to the quantitative cervical vertebral maturation (QCVM) for adolescents with normal occlusion, mixed longitudinal data were used. The samples included 87 adolescents aged from 8 to 18 y old with normal occlusion (32 males, 55 females) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year, lasting for 6 y. The longitudinal sagittal growth changes of maxilla and mandible according to QCVM were measured. There were some significant differences between maxilla and mandible according to QCVM. The sagittal growth change of maxilla showed a trend towards high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. The sagittal growth change of mandible showed a trend towards accelerating velocity-->high velocity-->decelerating velocity-->completing velocity from QCVM stage I to stage IV. With sagittal relationship, growth magnitude was almost the same between maxilla and mandible at QCVM stage I. At stage II the growth of mandible exceeded that of maxilla and growth in mandible continued at stages III and IV, while the maxilla ceased to grow. Growth magnitude was greater and the growth duration was longer with male mandible. It is concluded that the longitudinal sagittal growth changes of maxilla and mandible on the basis of QCVM is of value in the orthodontic practice.

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

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.

Impedance-matched Marx generators

NASA Astrophysics Data System (ADS)

Stygar, W. A.; LeChien, K. R.; Mazarakis, M. G.; Savage, M. E.; Stoltzfus, B. S.; Austin, K. N.; Breden, E. W.; Cuneo, M. E.; Hutsel, B. T.; Lewis, S. A.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Reisman, D. B.; Sceiford, M. E.; Wisher, M. L.

2017-04-01

We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs). The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with L C time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22 -Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19 -Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.

Group Sequential Testing of the Predictive Accuracy of a Continuous Biomarker with Unknown Prevalence

PubMed Central

Koopmeiners, Joseph S.; Feng, Ziding

2015-01-01

Group sequential testing procedures have been proposed as an approach to conserving resources in biomarker validation studies. Previously, Koopmeiners and Feng (2011) derived the asymptotic properties of the sequential empirical positive predictive value (PPV) and negative predictive value curves, which summarize the predictive accuracy of a continuous marker, under case-control sampling. A limitation of their approach is that the prevalence can not be estimated from a case-control study and must be assumed known. In this manuscript, we consider group sequential testing of the predictive accuracy of a continuous biomarker with unknown prevalence. First, we develop asymptotic theory for the sequential empirical PPV and NPV curves when the prevalence must be estimated, rather than assumed known in a case-control study. We then discuss how our results can be combined with standard group sequential methods to develop group sequential testing procedures and bias-adjusted estimators for the PPV and NPV curve. The small sample properties of the proposed group sequential testing procedures and estimators are evaluated by simulation and we illustrate our approach in the context of a study to validate a novel biomarker for prostate cancer. PMID:26537180

A sequential data assimilation approach for the joint reconstruction of mantle convection and surface tectonics

NASA Astrophysics Data System (ADS)

Bocher, M.; Coltice, N.; Fournier, A.; Tackley, P. J.

2016-01-01

With the progress of mantle convection modelling over the last decade, it now becomes possible to solve for the dynamics of the interior flow and the surface tectonics to first order. We show here that tectonic data (like surface kinematics and seafloor age distribution) and mantle convection models with plate-like behaviour can in principle be combined to reconstruct mantle convection. We present a sequential data assimilation method, based on suboptimal schemes derived from the Kalman filter, where surface velocities and seafloor age maps are not used as boundary conditions for the flow, but as data to assimilate. Two stages (a forecast followed by an analysis) are repeated sequentially to take into account data observed at different times. Whenever observations are available, an analysis infers the most probable state of the mantle at this time, considering a prior guess (supplied by the forecast) and the new observations at hand, using the classical best linear unbiased estimate. Between two observation times, the evolution of the mantle is governed by the forward model of mantle convection. This method is applied to synthetic 2-D spherical annulus mantle cases to evaluate its efficiency. We compare the reference evolutions to the estimations obtained by data assimilation. Two parameters control the behaviour of the scheme: the time between two analyses, and the amplitude of noise in the synthetic observations. Our technique proves to be efficient in retrieving temperature field evolutions provided the time between two analyses is ≲10 Myr. If the amplitude of the a priori error on the observations is large (30 per cent), our method provides a better estimate of surface tectonics than the observations, taking advantage of the information within the physics of convection.

A Sequential Sextet (Portraits of Faith Stages in One Family).

ERIC Educational Resources Information Center

Gross, Francis L., Jr.

1981-01-01

Discusses faith in the context of Catholic education as a way of knowing. Describes James Fowler's developmental theories showing the presence of a sequence in the way individuals experience intellectual growth. Presents six short theoretical characterizations showing a family in six stages of faith development. (DMM)

A priori evaluation of two-stage cluster sampling for accuracy assessment of large-area land-cover maps

USGS Publications Warehouse

Wickham, J.D.; Stehman, S.V.; Smith, J.H.; Wade, T.G.; Yang, L.

2004-01-01

Two-stage cluster sampling reduces the cost of collecting accuracy assessment reference data by constraining sample elements to fall within a limited number of geographic domains (clusters). However, because classification error is typically positively spatially correlated, within-cluster correlation may reduce the precision of the accuracy estimates. The detailed population information to quantify a priori the effect of within-cluster correlation on precision is typically unavailable. Consequently, a convenient, practical approach to evaluate the likely performance of a two-stage cluster sample is needed. We describe such an a priori evaluation protocol focusing on the spatial distribution of the sample by land-cover class across different cluster sizes and costs of different sampling options, including options not imposing clustering. This protocol also assesses the two-stage design's adequacy for estimating the precision of accuracy estimates for rare land-cover classes. We illustrate the approach using two large-area, regional accuracy assessments from the National Land-Cover Data (NLCD), and describe how the a priorievaluation was used as a decision-making tool when implementing the NLCD design.

A PRIOR EVALUATION OF TWO-STAGE CLUSTER SAMPLING FOR ACCURACY ASSESSMENT OF LARGE-AREA LAND-COVER MAPS

EPA Science Inventory

Two-stage cluster sampling reduces the cost of collecting accuracy assessment reference data by constraining sample elements to fall within a limited number of geographic domains (clusters). However, because classification error is typically positively spatially correlated, withi...

Single-stage laparoscopic common bile duct exploration and cholecystectomy versus two-stage endoscopic stone extraction followed by laparoscopic cholecystectomy for patients with gallbladder stones with common bile duct stones: systematic review and meta-analysis of randomized trials with trial sequential analysis.

PubMed

Singh, Anand Narayan; Kilambi, Ragini

2018-03-30

The ideal management of common bile duct (CBD) stones associated with gall stones is a matter of debate. We planned a meta-analysis of randomized trials comparing single-stage laparoscopic CBD exploration and cholecystectomy (LCBDE) with two-stage preoperative endoscopic stone extraction followed by cholecystectomy (ERCP + LC). We searched the Pubmed/Medline, Web of science, Science citation index, Google scholar and Cochrane Central Register of Controlled trials electronic databases till June 2017 for all English language randomized trials comparing the two approaches. Statistical analysis was performed using Review Manager (RevMan) [Computer program], Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014 and results were expressed as odds ratio for dichotomous variables and mean difference for continuous. p value ≤ 0.05 was considered significant. Trial sequential analysis (TSA) was performed using TSA version 0.9.5.5 (Copenhagen: The Copenhagen Trial Unit, Centre for Clinical Intervention Research, 2016). PROSPERO trial registration number is CRD42017074673. A total of 11 trials were included in the analysis, with a total of 1513 patients (751-LCBDE; 762-ERCP + LC). LCBDE was found to have significantly lower rates of technical failure [OR 0.59, 95% CI (0.38, 0.93), p = 0.02] and shorter hospital stay [MD - 1.63, 95% CI (- 3.23, - 0.03), p = 0.05]. There was no significant difference in mortality [OR 0.37, 95% CI (0.09, 1.51), p = 0.17], morbidity [OR 0.97, 95% CI (0.70, 1.33), p = 0.84], cost [MD - 379.13, 95% CI (- 784.80, 111.2), p = 0.13] or recurrent/retained stones [OR 1.01, 95% CI (0.38, 2.73), p = 0.98]. TSA showed that although the Z-curve crossed the boundaries of conventional significance, the estimated information size is yet to be achieved. Single-stage LCBDE is superior to ERCP + LC in terms of technical success and shorter hospital stay in good-risk patients with gallstones and CBD stones, where expertise, operative time and instruments are available.

Forced guidance and distribution of practice in sequential information processing.

NASA Technical Reports Server (NTRS)

Decker, L. R.; Rogers, C. A., Jr.

1973-01-01

Distribution of practice and forced guidance were used in a sequential information-processing task in an attempt to increase the capacity of human information-processing mechanisms. A reaction time index of the psychological refractory period was used as the response measure. Massing of practice lengthened response times while forced guidance shortened them. Interpretation was in terms of load reduction upon the response-selection stage of the information-processing system.-

MSFC Skylab airlock module, volume 1. [systems design and performance

NASA Technical Reports Server (NTRS)

1974-01-01

The history and development of the Skylab Airlock Module and Payload Shroud is presented from initial concept through final design. A summary is given of the Airlock features and systems. System design and performance are presented for the Spent Stage Experiment Support Module, structure and mechanical systems, mass properties, thermal and environmental control systems, EVA/IVA suite system, electrical power system, sequential system, sequential system, and instrumentation system.

The effect of two-stage pretreatment on the physical and chemical characteristic of oil palm empty fruit bunch for bioethanol production

NASA Astrophysics Data System (ADS)

Burhani, Dian; Putri, Ary Mauliva Hada; Waluyo, Joko; Nofiana, Yulia; Sudiyani, Yanni

2017-11-01

This study investigated the effect of two-stage pretreatment using dilute H2SO4 followed by dilute NaOH on the physical characteristic of oil palm empty fruit bunch including crystallinity index, chemical bonding and morphology. Its effect on chemical characteristic, especially the sugar recovery have also been observed. The results showed a low crystallinity degree measured from acid-alkaline OPEFB which was confirmed by the FTIR spectra with the decrease intensity of CH2 bending vibration at 1433 cm-1 and crystallinity index in the amount of 57.53 %. Silica-bodies which was noticed from the raw OPEFB was successfully removed after the sequential pretreatment. High cellulose and lignin removal around 90 % and 73.1 %, respectively with a trace of acetic acid and no furfural content were achieved at the end of the pretreatment.

Enhanced biodiesel production in Neochloris oleoabundans by a semi-continuous process in two stage photobioreactors.

PubMed

Yoon, Se Young; Hong, Min Eui; Chang, Won Seok; Sim, Sang Jun

2015-07-01

Under autotrophic conditions, highly productive biodiesel production was achieved using a semi-continuous culture system in Neochloris oleoabundans. In particular, the flue gas generated by combustion of liquefied natural gas and natural solar radiation were used for cost-effective microalgal culture system. In semi-continuous culture, the greater part (~80%) of the culture volume containing vegetative cells grown under nitrogen-replete conditions in a first photobioreactor (PBR) was directly transferred to a second PBR and cultured sequentially under nitrogen-deplete conditions for accelerating oil accumulation. As a result, in semi-continuous culture, the productivities of biomass and biodiesel in the cells were increased by 58% (growth phase) and 51% (induction phase) compared to the cells in batch culture, respectively. The semi-continuous culture system using two stage photobioreactors is a very efficient strategy to further improve biodiesel production from microalgae under photoautotrophic conditions.

Restoring paleomagnetic data in complex superposed folding settings: The Boltaña anticline (Southern Pyrenees)

NASA Astrophysics Data System (ADS)

Mochales, T.; Pueyo, E. L.; Casas, A. M.; Barnolas, A.

2016-03-01

Complex kinematic scenarios in fold-and-thrust belts often produce superposed and non-coaxial folding. Interpretation of primary linear indicators must be based on a careful restoration to the undeformed stage following the reverse order of the deformation events. Therefore, sequential restoration to the ancient coordinate system is of key importance to obtain reliable kinematic interpretations using paleomagnetic data. In this paper, a new paleomagnetic study in the western flank of the Boltaña anticline (Southern Pyrenees) illustrates a case study of a complex tectonic setting having superposed, non-coaxial folds. The first stage of NW-SE folding linked to the oblique Boltaña anticline took place during Lutetian times. The second stage was linked to the vertical axis rotation and placed the Boltaña anticline in its present-day N-S configuration. Our data support a long-lasting Lutetian to Priabonian period with main rotational activity during the Bartonian-Priabonian; other authors support a VAR coeval with anticlinal growth. The third stage resulted in southwards tilting related to the emplacement of the N120E striking Guarga basement thrust (Oligocene-Early Miocene). Based on this deformational history, a sequential restoration was applied and compared with the classic bedding correction. At the site scale, single bedding correction gives errors ranging between 31° and - 31° in the estimation of vertical axis rotations. At the locality scale, in sites grouped in three folds (from W to E Arbella, Planillo and San Felizes), the bedding corrected data display rotation values in accordance with those found in the Ainsa Basin by other authors. Sequential restoration (based on the afore-mentioned evolution in three-steps) improves both some locality-means and the internal consistency of the data. Therefore, reasonably-constrained sequential restoration becomes essential to reconstruct the actual history of superposed folding areas.

Sequential search leads to faster, more efficient fragment-based de novo protein structure prediction.

PubMed

de Oliveira, Saulo H P; Law, Eleanor C; Shi, Jiye; Deane, Charlotte M

2018-04-01

Most current de novo structure prediction methods randomly sample protein conformations and thus require large amounts of computational resource. Here, we consider a sequential sampling strategy, building on ideas from recent experimental work which shows that many proteins fold cotranslationally. We have investigated whether a pseudo-greedy search approach, which begins sequentially from one of the termini, can improve the performance and accuracy of de novo protein structure prediction. We observed that our sequential approach converges when fewer than 20 000 decoys have been produced, fewer than commonly expected. Using our software, SAINT2, we also compared the run time and quality of models produced in a sequential fashion against a standard, non-sequential approach. Sequential prediction produces an individual decoy 1.5-2.5 times faster than non-sequential prediction. When considering the quality of the best model, sequential prediction led to a better model being produced for 31 out of 41 soluble protein validation cases and for 18 out of 24 transmembrane protein cases. Correct models (TM-Score > 0.5) were produced for 29 of these cases by the sequential mode and for only 22 by the non-sequential mode. Our comparison reveals that a sequential search strategy can be used to drastically reduce computational time of de novo protein structure prediction and improve accuracy. Data are available for download from: http://opig.stats.ox.ac.uk/resources. SAINT2 is available for download from: https://github.com/sauloho/SAINT2. saulo.deoliveira@dtc.ox.ac.uk. Supplementary data are available at Bioinformatics online.

Staging presymptomatic type 1 diabetes: a scientific statement of JDRF, the Endocrine Society, and the American Diabetes Association.

PubMed

Insel, Richard A; Dunne, Jessica L; Atkinson, Mark A; Chiang, Jane L; Dabelea, Dana; Gottlieb, Peter A; Greenbaum, Carla J; Herold, Kevan C; Krischer, Jeffrey P; Lernmark, Åke; Ratner, Robert E; Rewers, Marian J; Schatz, Desmond A; Skyler, Jay S; Sosenko, Jay M; Ziegler, Anette-G

2015-10-01

Insights from prospective, longitudinal studies of individuals at risk for developing type 1 diabetes have demonstrated that the disease is a continuum that progresses sequentially at variable but predictable rates through distinct identifiable stages prior to the onset of symptoms. Stage 1 is defined as the presence of β-cell autoimmunity as evidenced by the presence of two or more islet autoantibodies with normoglycemia and is presymptomatic, stage 2 as the presence of β-cell autoimmunity with dysglycemia and is presymptomatic, and stage 3 as onset of symptomatic disease. Adoption of this staging classification provides a standardized taxonomy for type 1 diabetes and will aid the development of therapies and the design of clinical trials to prevent symptomatic disease, promote precision medicine, and provide a framework for an optimized benefit/risk ratio that will impact regulatory approval, reimbursement, and adoption of interventions in the early stages of type 1 diabetes to prevent symptomatic disease. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection

PubMed Central

Kremastinou, J.; Polymerou, V.; Lavranos, D.; Aranda Arrufat, A.; Harwood, J.; Martínez Lorenzo, M. J.; Ng, K. P.; Queiros, L.; Vereb, I.

2016-01-01

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum. The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results. PMID:27358468

Mentor judgements and decision-making in the assessment of student nurse competence in practice: A mixed-methods study.

PubMed

Burden, Sarah; Topping, Anne Elizabeth; O'Halloran, Catherine

2018-05-01

To investigate how mentors form judgements and reach summative assessment decisions regarding student competence in practice. Competence assessment is a significant component of pre-registration nursing programmes in the United Kingdom. Concerns exist that assessments are subjective, lack consistency and that mentors fail to judge student performance as unsatisfactory. A two-stage sequential embedded mixed-methods design. Data collected 2012-2013. This study involved a whole student cohort completing a UK undergraduate adult nursing programme (N = 41). Stage 1: quantitative data on mentor conduct of assessment interviews and the final decision recorded (N = 330 from 270 mentors) were extracted from student Practice Assessment Documents (PADs). Stage 2: mentor feedback in student PADs was used in Stimulated Recall interviews with a purposive sample of final placement mentors (N = 17). These were thematically analysed. Findings were integrated to develop a theoretically driven model of mentor decision-making. Course assessment strategies and documentation had limited effect in framing mentor judgements and decisions. Rather, mentors amassed impressions, moderated by expectations of an "idealized student" by practice area and programme stage that influenced their management and outcome of the assessment process. These impressions were accumulated and combined into judgements that informed the final decision. This process can best be understood and conceptualized through the Brunswik's lens model of social judgement. Mentor decisions were reasoned and there was a shared understanding of judgement criteria and their importance. This impression-based nature of mentor decision-making questions the reliability and validity of competency-based assessments used in nursing pre-registration programmes. © 2017 John Wiley & Sons Ltd.

Strongyloides stercoralis-infected dogs as a model for human disseminated strongyloidiasis

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

Aikens, L.M.

1989-01-01

The route of migration of Strongyloides stercoralis third-stage infective larvae was explored in primary and autogenous infections in the dog. Larvae was radiolabeled by one of two means: (1) by culture of the free-living L3 stage in a nutrient medium, deficient in methionine, supplemented with ({sup 75}Se)Selenomethionine, and (2) by feeding of ({sup 75}Se)Selenomethionine-labeled bacteria to microbiverous L1 and L2 stages. Third-stage labeled larvae were then injected into 10-day-old pups either subcutaneously, to study primary migration, or into the distal ileum, to study autogenous migration. At intervals after infection pups were killed and whole body compressed organ autoradiography done onmore » individual tissues to determine organ-specific larval transit sites. Autoradiographic recoveries were analyzed in the context of a series of mathematical models designed to test migratory route hypotheses. Postulated routes of migration for primary infections included (1) the Null Hypothesis or Scramble Route in which larvae migrate to the intestines by any available route, (2) the Classical Pulmonary Route in which larvae migrate sequentially from skin, to blood, to lungs, to the trachea, esophagus and intestines, and (3) the Head Migration Route in which larvae move from caudal to cranial sites within the skin and muscle before entering the intestines. Postulated routes for autoinfective migration reiterated 1 and 2 above. Least squares comparisons, of calculated models to observed autoradiographic distributions, led us to conclude that there was no reason to reject the simplest assumption that larvae move by any available route to the definitive site in both forms of migration. Sampling through tracheostomy sites in 14 pups for larval migrants confirmed this conclusion.« less

The Effect of Sequential Dependence on the Sampling Distributions of KR-20, KR-21, and Split-Halves Reliabilities.

ERIC Educational Resources Information Center

Sullins, Walter L.

Five-hundred dichotomously scored response patterns were generated with sequentially independent (SI) items and 500 with dependent (SD) items for each of thirty-six combinations of sampling parameters (i.e., three test lengths, three sample sizes, and four item difficulty distributions). KR-20, KR-21, and Split-Half (S-H) reliabilities were…

Implementing reduced-risk integrated pest management in fresh-market cabbage: influence of sampling parameters, and validation of binomial sequential sampling plans for the cabbage looper (Lepidoptera Noctuidae).

PubMed

Burkness, Eric C; Hutchison, W D

2009-10-01

Populations of cabbage looper, Trichoplusiani (Lepidoptera: Noctuidae), were sampled in experimental plots and commercial fields of cabbage (Brasicca spp.) in Minnesota during 1998-1999 as part of a larger effort to implement an integrated pest management program. Using a resampling approach and the Wald's sequential probability ratio test, sampling plans with different sampling parameters were evaluated using independent presence/absence and enumerative data. Evaluations and comparisons of the different sampling plans were made based on the operating characteristic and average sample number functions generated for each plan and through the use of a decision probability matrix. Values for upper and lower decision boundaries, sequential error rates (alpha, beta), and tally threshold were modified to determine parameter influence on the operating characteristic and average sample number functions. The following parameters resulted in the most desirable operating characteristic and average sample number functions; action threshold of 0.1 proportion of plants infested, tally threshold of 1, alpha = beta = 0.1, upper boundary of 0.15, lower boundary of 0.05, and resampling with replacement. We found that sampling parameters can be modified and evaluated using resampling software to achieve desirable operating characteristic and average sample number functions. Moreover, management of T. ni by using binomial sequential sampling should provide a good balance between cost and reliability by minimizing sample size and maintaining a high level of correct decisions (>95%) to treat or not treat.

Extended follow-up of the CYCLOFA-LUNE trial comparing two sequential induction and maintenance treatment regimens for proliferative lupus nephritis based either on cyclophosphamide or on cyclosporine A.

PubMed

Závada, J; Sinikka Pesicková, S; Rysavá, R; Horák, P; Hrncír, Z; Lukác, J; Rovensky, J; Vítová, J; Havrda, M; Rychlík, I; Böhmova, J; Vlasáková, V; Slatinská, J; Zadrazil, J; Olejárová, M; Tegzova, D; Tesar, V

2014-01-01

Objective To evaluate the extended follow-up of the CYCLOFA-LUNE trial, a randomized prospective trial comparing two sequential induction and maintenance treatment regimens for proliferative lupus nephritis based either on cyclophosphamide (CPH) or cyclosporine A (CyA). Patients and methods Data for kidney function and adverse events were collected by a cross-sectional survey for 38 of 40 patients initially randomized in the CYCLOFA-LUNE trial. Results The median follow-up time was 7.7 years (range 5.0-10.3). Rates of renal impairment and end-stage renal disease, adverse events (death, cardiovascular event, tumor, premature menopause) did not differ between the CPH and CyA group, nor did mean serum creatinine, 24 h proteinuria and SLICC damage score at last follow-up. Most patients in both groups were still treated with glucocorticoids, other immunosuppressant agents and blood pressure lowering drugs. Conclusion An immunosuppressive regimen based on CyA achieved similar clinical results to that based on CPH in the very long term.

GOST: A generic ordinal sequential trial design for a treatment trial in an emerging pandemic.

PubMed

Whitehead, John; Horby, Peter

2017-03-01

Conducting clinical trials to assess experimental treatments for potentially pandemic infectious diseases is challenging. Since many outbreaks of infectious diseases last only six to eight weeks, there is a need for trial designs that can be implemented rapidly in the face of uncertainty. Outbreaks are sudden and unpredictable and so it is essential that as much planning as possible takes place in advance. Statistical aspects of such trial designs should be evaluated and discussed in readiness for implementation. This paper proposes a generic ordinal sequential trial design (GOST) for a randomised clinical trial comparing an experimental treatment for an emerging infectious disease with standard care. The design is intended as an off-the-shelf, ready-to-use robust and flexible option. The primary endpoint is a categorisation of patient outcome according to an ordinal scale. A sequential approach is adopted, stopping as soon as it is clear that the experimental treatment has an advantage or that sufficient advantage is unlikely to be detected. The properties of the design are evaluated using large-sample theory and verified for moderate sized samples using simulation. The trial is powered to detect a generic clinically relevant difference: namely an odds ratio of 2 for better rather than worse outcomes. Total sample sizes (across both treatments) of between 150 and 300 patients prove to be adequate in many cases, but the precise value depends on both the magnitude of the treatment advantage and the nature of the ordinal scale. An advantage of the approach is that any erroneous assumptions made at the design stage about the proportion of patients falling into each outcome category have little effect on the error probabilities of the study, although they can lead to inaccurate forecasts of sample size. It is important and feasible to pre-determine many of the statistical aspects of an efficient trial design in advance of a disease outbreak. The design can then be tailored to the specific disease under study once its nature is better understood.

Minimizing the Maximum Expected Sample Size in Two-Stage Phase II Clinical Trials with Continuous Outcomes

PubMed Central

Wason, James M. S.; Mander, Adrian P.

2012-01-01

Two-stage designs are commonly used for Phase II trials. Optimal two-stage designs have the lowest expected sample size for a specific treatment effect, for example, the null value, but can perform poorly if the true treatment effect differs. Here we introduce a design for continuous treatment responses that minimizes the maximum expected sample size across all possible treatment effects. The proposed design performs well for a wider range of treatment effects and so is useful for Phase II trials. We compare the design to a previously used optimal design and show it has superior expected sample size properties. PMID:22651118

Increasing efficiency of preclinical research by group sequential designs

PubMed Central

Piper, Sophie K.; Rex, Andre; Florez-Vargas, Oscar; Karystianis, George; Schneider, Alice; Wellwood, Ian; Siegerink, Bob; Ioannidis, John P. A.; Kimmelman, Jonathan; Dirnagl, Ulrich

2017-01-01

Despite the potential benefits of sequential designs, studies evaluating treatments or experimental manipulations in preclinical experimental biomedicine almost exclusively use classical block designs. Our aim with this article is to bring the existing methodology of group sequential designs to the attention of researchers in the preclinical field and to clearly illustrate its potential utility. Group sequential designs can offer higher efficiency than traditional methods and are increasingly used in clinical trials. Using simulation of data, we demonstrate that group sequential designs have the potential to improve the efficiency of experimental studies, even when sample sizes are very small, as is currently prevalent in preclinical experimental biomedicine. When simulating data with a large effect size of d = 1 and a sample size of n = 18 per group, sequential frequentist analysis consumes in the long run only around 80% of the planned number of experimental units. In larger trials (n = 36 per group), additional stopping rules for futility lead to the saving of resources of up to 30% compared to block designs. We argue that these savings should be invested to increase sample sizes and hence power, since the currently underpowered experiments in preclinical biomedicine are a major threat to the value and predictiveness in this research domain. PMID:28282371

Blastocyst culture using single versus sequential media in clinical IVF: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Sfontouris, Ioannis A; Martins, Wellington P; Nastri, Carolina O; Viana, Iara G R; Navarro, Paula A; Raine-Fenning, Nick; van der Poel, Sheryl; Rienzi, Laura; Racowsky, Catherine

2016-10-01

The purpose of this study was to undertake a review of the available evidence comparing the use of a single medium versus sequential media for embryo culture to the blastocyst stage in clinical IVF. We searched the Cochrane Central, PubMed, Scopus, ClinicalTrials.gov, Current Controlled Trials and WHO International Clinical Trials Registry Platform to identify randomized controlled trials comparing single versus sequential media for blastocyst culture and ongoing pregnancy rate. Included studies randomized either oocytes/zygotes or women. Eligible oocyte/zygote studies were analyzed to assess the risk difference (RD) and 95 % confidence intervals (CI) between the two media systems; eligible woman-based studies were analyzed to assess the risk ratio (RR) and 95 % CI for clinical pregnancy rate. No differences were observed between single and sequential media for either ongoing pregnancy per randomized woman (relative risk (RR) = 0.9, 95 % CI = 0.7 to 1.3, two studies including 246 women, I 2  = 0 %) or clinical pregnancy per randomized woman (RR = 1.0, 95 % CI = 0.7 to 1.4, one study including 100 women); or miscarriage per clinical pregnancy: RR = 1.3, 95 % CI = 0.4 to 4.3, two studies including 246 participants, I 2  = 0 %). Single media use was associated with an increase blastocyst formation per randomized oocyte/zygote (relative distribution (RD) = +0.06, 95 % CI = +0.01 to +0.12, ten studies including 7455 oocytes/zygotes, I 2  = 83 %) but not top/high blastocyst formation (RD = +0.05, 95 % CI = -0.01 to +0.11, five studies including 3879 oocytes/zygotes, I 2  = 93 %). The overall quality of the evidence was very low for all these four outcomes. Although using a single medium for extended culture has some practical advantages and blastocyst formation rates appear to be higher, there is insufficient evidence to recommend either sequential or single-step media as being superior for the culture of embryos to days 5/6. Future studies comparing these two media systems in well-designed trials should be performed.

Co-expression of HoxA9 and bcr-abl genes in chronic myeloid leukemia.

PubMed

Tedeschi, Fabián A; Cardozo, Maria A; Valentini, Rosanna; Zalazar, Fabián E

2010-05-01

We have analyzed the co-expression of the bcr-abl and HoxA9 genes in the follow-up of patients with chronic myeloid leukemia (CML). In the present work we measured the HoxA9 and bcr-abl gene expression in sequential samples. In all patients, bcr-abl and HoxA9 were expressed at detectable levels in every sample. When the results were expressed in relation to abl, two different situations were found: (a) patients clinically stable at second sampling, with low relative risk at diagnosis (low Sokal's score), did not show significant differences in both bcr-abl and HoxA9 levels in the sequential samples analyzed, and (b) patients with poor prognosis (showing intermediate or high Sokal's score at diagnosis) had increased expression of bcr-abl as well as HoxA9 genes (p < 0.05). Since HoxA9 gene expression remains at relatively constant levels throughout adult life, our results could reflect actual changes in the expression rate of this gene associated with bcr-abl during the progression of CML.

Alcohol and the pancreas. II. Pancreatic morphology of advanced alcoholic pancreatitis.

PubMed

Noronha, M; Bordalo, O; Dreiling, D A

1981-08-01

The histopathology of advanced chronic alcoholic pancreatitis is dominated by cellular degeneration, atrophy and fibrosis. Sequential changes in the histopathology of alcoholic pancreatic disease has been defined and traced from initial injury to end-stage disease. These sequential histopathologies have been correlated with clinical syndrome and secretory patterns. The data are more consistent with a toxic-metabolic pathogenesis of alcoholic pancreatitis than the previous Big Duct and Small Duct hypotheses.

Adrenal vein sampling in primary aldosteronism: concordance of simultaneous vs sequential sampling.

PubMed

Almarzooqi, Mohamed-Karji; Chagnon, Miguel; Soulez, Gilles; Giroux, Marie-France; Gilbert, Patrick; Oliva, Vincent L; Perreault, Pierre; Bouchard, Louis; Bourdeau, Isabelle; Lacroix, André; Therasse, Eric

2017-02-01

Many investigators believe that basal adrenal venous sampling (AVS) should be done simultaneously, whereas others opt for sequential AVS for simplicity and reduced cost. This study aimed to evaluate the concordance of sequential and simultaneous AVS methods. Between 1989 and 2015, bilateral simultaneous sets of basal AVS were obtained twice within 5 min, in 188 consecutive patients (59 women and 129 men; mean age: 53.4 years). Selectivity was defined by adrenal-to-peripheral cortisol ratio ≥2, and lateralization was defined as an adrenal aldosterone-to-cortisol ratio ≥2, the contralateral side. Sequential AVS was simulated using right sampling at -5 min (t = -5) and left sampling at 0 min (t = 0). There was no significant difference in mean selectivity ratio (P = 0.12 and P = 0.42 for the right and left sides respectively) and in mean lateralization ratio (P = 0.93) between t = -5 and t = 0. Kappa for selectivity between 2 simultaneous AVS was 0.71 (95% CI: 0.60-0.82), whereas it was 0.84 (95% CI: 0.76-0.92) and 0.85 (95% CI: 0.77-0.93) between sequential and simultaneous AVS at respectively -5 min and at 0 min. Kappa for lateralization between 2 simultaneous AVS was 0.84 (95% CI: 0.75-0.93), whereas it was 0.86 (95% CI: 0.78-0.94) and 0.80 (95% CI: 0.71-0.90) between sequential AVS and simultaneous AVS at respectively -5 min at 0 min. Concordance between simultaneous and sequential AVS was not different than that between 2 repeated simultaneous AVS in the same patient. Therefore, a better diagnostic performance is not a good argument to select the AVS method. © 2017 European Society of Endocrinology.

Chemoradiotherapy for stage III non-small cell lung cancer: have we reached the limit?

PubMed

Xu, Peng; Le Pechoux, Cecile

2015-12-01

Lung cancer is the leading cause of cancer-related mortality in men and the second leading cause in women. Approximately 85% of lung cancer patients have non-small cell lung cancer (NSCLC), and most present with advanced stage at diagnosis. The current treatment for such patients is chemoradiation (CRT) provided concurrently preferably or sequentially with chemotherapy, using conventionally fractionated radiation doses in the range of 60 to 66 Gy in 30 to 33 fractions. An individual patient data based metaanalysis has shown that in good performance status (PS), concomitant CRT was associated to improved survival by 4.5% compared to sequential combination (5-year survival rate of 15.1% and 10.6% respectively). In the recent years, improvement of modern technique of radiotherapy (RT) and new chemotherapy drugs may be favorable for the patients. Furthermore, the positron emission tomography-computed tomography (PET-CT) contributes to improved delineation of RT especially in terms of nodal involvement. Improving outcomes for patients with stage III disease remains a challenge, this review will address the questions that are considered fundamental to improving outcome in patients with stage III NSCLC.

Feasibility of sequential adjuvant chemotherapy with a 3-month oxaliplatin-based regimen followed by 3 months of capecitabine in patients with stage III and high-risk stage II colorectal cancer: JSWOG-C2 study

PubMed Central

Tsuruta, Atsushi; Yamashita, Kazuki; Tanioka, Hiroaki; Tsuji, Akihito; Inukai, Michio; Yamakawa, Toshiki; Yamatsuji, Tomoki; Yoshimitsu, Masanori; Toyota, Kazuhiro; Yamano, Taketoshi; Nagasaka, Takeshi; Okajima, Masazumi

2016-01-01

Background Six months of oxaliplatin-based chemotherapy is the standard adjuvant chemotherapy for completely resected stage III colorectal cancer (CRC). Also, patients with stage II CRC who are considered to be at high risk of disease recurrence often receive the same adjuvant chemotherapy treatment. We prospectively investigated the extent and degree of neuropathy suffered by stage III and high-risk stage II resectable CRC patients who underwent sequential approach involving 3 months of an oxaliplatin-based regimen followed by 3 months of capecitabine. Patients and methods Patients with completely resected stage III and high-risk stage II CRC aged ≥20 years were eligible. Patients were treated with folinic acid, fluorouracil, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) for 3 months followed by capecitabine (2,500 mg/m2 on days 1–14 every 3 weeks) for 3 months. Primary end points were frequency and the grade of oxaliplatin-induced neurotoxicity as evaluated using the physician-based Common Terminology Criteria for Adverse Events version 4.0 (CTCAE) grading and the patient-based scale, self-reported Patient Neurotoxicity Questionnaire. Results Ninety-one patients were enrolled and 86 patients assessed. Eighty-four percent of patients completed the planned oxaliplatin-based therapy for 3 months, and 63% of patients completed all treatments for the full 6 months. Overall incidences of grade 3 or 4 peripheral sensory or motor neuropathy according to the CTCAE were 3.5% and 1.2%, respectively. Regarding the peripheral sensory neuropathy, the proportion of Patient Neurotoxicity Questionnaire (grade C–E) and CTCAE (grade 2–4) at months 1.5/3/6 were 11.3/22.1/29.4% and 5.3/4.4/11.3%, respectively (Spearman correlation coefficient: 0.47). Conclusion A sequential approach to adjuvant chemotherapy with 3 months of an oxaliplatin-based regimen followed by 3 months of capecitabine was tolerated by patients and associated with a low incidence of neuropathy. PMID:27920498

Feasibility of sequential adjuvant chemotherapy with a 3-month oxaliplatin-based regimen followed by 3 months of capecitabine in patients with stage III and high-risk stage II colorectal cancer: JSWOG-C2 study.

PubMed

Tsuruta, Atsushi; Yamashita, Kazuki; Tanioka, Hiroaki; Tsuji, Akihito; Inukai, Michio; Yamakawa, Toshiki; Yamatsuji, Tomoki; Yoshimitsu, Masanori; Toyota, Kazuhiro; Yamano, Taketoshi; Nagasaka, Takeshi; Okajima, Masazumi

2016-01-01

Six months of oxaliplatin-based chemotherapy is the standard adjuvant chemotherapy for completely resected stage III colorectal cancer (CRC). Also, patients with stage II CRC who are considered to be at high risk of disease recurrence often receive the same adjuvant chemotherapy treatment. We prospectively investigated the extent and degree of neuropathy suffered by stage III and high-risk stage II resectable CRC patients who underwent sequential approach involving 3 months of an oxaliplatin-based regimen followed by 3 months of capecitabine. Patients with completely resected stage III and high-risk stage II CRC aged ≥20 years were eligible. Patients were treated with folinic acid, fluorouracil, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) for 3 months followed by capecitabine (2,500 mg/m 2 on days 1-14 every 3 weeks) for 3 months. Primary end points were frequency and the grade of oxaliplatin-induced neurotoxicity as evaluated using the physician-based Common Terminology Criteria for Adverse Events version 4.0 (CTCAE) grading and the patient-based scale, self-reported Patient Neurotoxicity Questionnaire. Ninety-one patients were enrolled and 86 patients assessed. Eighty-four percent of patients completed the planned oxaliplatin-based therapy for 3 months, and 63% of patients completed all treatments for the full 6 months. Overall incidences of grade 3 or 4 peripheral sensory or motor neuropathy according to the CTCAE were 3.5% and 1.2%, respectively. Regarding the peripheral sensory neuropathy, the proportion of Patient Neurotoxicity Questionnaire (grade C-E) and CTCAE (grade 2-4) at months 1.5/3/6 were 11.3/22.1/29.4% and 5.3/4.4/11.3%, respectively (Spearman correlation coefficient: 0.47). A sequential approach to adjuvant chemotherapy with 3 months of an oxaliplatin-based regimen followed by 3 months of capecitabine was tolerated by patients and associated with a low incidence of neuropathy.

Determination of cadmium and lead in table salt by sequential multi-element flame atomic absorption spectrometry.

PubMed

Amorim, Fábio A C; Ferreira, Sérgio L C

2005-02-28

In the present paper, a simultaneous pre-concentration procedure for the sequential determination of cadmium and lead in table salt samples using flame atomic absorption spectrometry is proposed. This method is based on the liquid-liquid extraction of cadmium(II) and lead(II) ions as dithizone complexes and direct aspiration of the organic phase for the spectrometer. The sequential determination of cadmium and lead is possible using a computer program. The optimization step was performed by a two-level fractional factorial design involving the variables: pH, dithizone mass, shaking time after addition of dithizone and shaking time after addition of solvent. In the studied levels these variables are not significant. The experimental conditions established propose a sample volume of 250mL and the extraction process using 4.0mL of methyl isobutyl ketone. This way, the procedure allows determination of cadmium and lead in table salt samples with a pre-concentration factor higher than 80, and detection limits of 0.3ngg(-1) for cadmium and 4.2ngg(-1) for lead. The precision expressed as relative standard deviation (n = 10) were 5.6 and 2.6% for cadmium concentration of 2 and 20ngg(-1), respectively, and of 3.2 and 1.1% for lead concentration of 20 and 200ngg(-1), respectively. Recoveries of cadmium and lead in several samples, measured by standard addition technique, proved also that this procedure is not affected by the matrix and can be applied satisfactorily for the determination of cadmium and lead in saline samples. The method was applied for the evaluation of the concentration of cadmium and lead in table salt samples consumed in Salvador City, Bahia, Brazil.

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.

Environmentally friendly microwave-assisted sequential extraction method followed by ICP-OES and ion-chromatographic analysis for rapid determination of sulphur forms in coal samples.

PubMed

Mketo, Nomvano; Nomngongo, Philiswa N; Ngila, J Catherine

2018-05-15

A rapid three-step sequential extraction method was developed under microwave radiation followed by inductively coupled plasma-optical emission spectroscopic (ICP-OES) and ion-chromatographic (IC) analysis for the determination of sulphur forms in coal samples. The experimental conditions of the proposed microwave-assisted sequential extraction (MW-ASE) procedure were optimized by using multivariate mathematical tools. Pareto charts generated from 2 3 full factorial design showed that, extraction time has insignificant effect on the extraction of sulphur species, therefore, all the sequential extraction steps were performed for 5 min. The optimum values according to the central composite designs and counter plots of the response surface methodology were 200 °C (microwave temperature) and 0.1 g (coal amount) for all the investigated extracting reagents (H 2 O, HCl and HNO 3 ). When the optimum conditions of the proposed MW-ASE procedure were applied in coal CRMs, SARM 18 showed more organic sulphur (72%) and the other two coal CRMs (SARMs 19 and 20) were dominated by sulphide sulphur species (52-58%). The sum of the sulphur forms from the sequential extraction steps have shown consistent agreement (95-96%) with certified total sulphur values on the coal CRM certificates. This correlation, in addition to the good precision (1.7%) achieved by the proposed procedure, suggests that the sequential extraction method is reliable, accurate and reproducible. To safe-guard the destruction of pyritic and organic sulphur forms in extraction step 1, water was used instead of HCl. Additionally, the notorious acidic mixture (HCl/HNO 3 /HF) was replaced by greener reagent (H 2 O 2 ) in the last extraction step. Therefore, the proposed MW-ASE method can be applied in routine laboratories for the determination of sulphur forms in coal and coal related matrices. Copyright © 2018 Elsevier B.V. All rights reserved.

Sulfur K-edge XANES and acid volatile sulfide analyses of changes in chemical speciation of S and Fe during sequential extraction of trace metals in anoxic sludge from biogas reactors.

PubMed

Shakeri Yekta, Sepehr; Gustavsson, Jenny; Svensson, Bo H; Skyllberg, Ulf

2012-01-30

The effect of sequential extraction of trace metals on sulfur (S) speciation in anoxic sludge samples from two lab-scale biogas reactors augmented with Fe was investigated. Analyses of sulfur K-edge X-ray absorption near edge structure (S XANES) spectroscopy and acid volatile sulfide (AVS) were conducted on the residues from each step of the sequential extraction. The S speciation in sludge samples after AVS analysis was also determined by S XANES. Sulfur was mainly present as FeS (≈ 60% of total S) and reduced organic S (≈ 30% of total S), such as organic sulfide and thiol groups, in the anoxic solid phase. Sulfur XANES and AVS analyses showed that during first step of the extraction procedure (the removal of exchangeable cations), a part of the FeS fraction corresponding to 20% of total S was transformed to zero-valent S, whereas Fe was not released into the solution during this transformation. After the last extraction step (organic/sulfide fraction) a secondary Fe phase was formed. The change in chemical speciation of S and Fe occurring during sequential extraction procedure suggests indirect effects on trace metals associated to the FeS fraction that may lead to incorrect results. Furthermore, by S XANES it was verified that the AVS analysis effectively removed the FeS fraction. The present results identified critical limitations for the application of sequential extraction for trace metal speciation analysis outside the framework for which the methods were developed. Copyright © 2011 Elsevier B.V. All rights reserved.

Estimating accuracy of land-cover composition from two-stage cluster sampling

USGS Publications Warehouse

Stehman, S.V.; Wickham, J.D.; Fattorini, L.; Wade, T.D.; Baffetta, F.; Smith, J.H.

2009-01-01

Land-cover maps are often used to compute land-cover composition (i.e., the proportion or percent of area covered by each class), for each unit in a spatial partition of the region mapped. We derive design-based estimators of mean deviation (MD), mean absolute deviation (MAD), root mean square error (RMSE), and correlation (CORR) to quantify accuracy of land-cover composition for a general two-stage cluster sampling design, and for the special case of simple random sampling without replacement (SRSWOR) at each stage. The bias of the estimators for the two-stage SRSWOR design is evaluated via a simulation study. The estimators of RMSE and CORR have small bias except when sample size is small and the land-cover class is rare. The estimator of MAD is biased for both rare and common land-cover classes except when sample size is large. A general recommendation is that rare land-cover classes require large sample sizes to ensure that the accuracy estimators have small bias. ?? 2009 Elsevier Inc.

Microfabricated thermal modulator for comprehensive two-dimensional micro gas chromatography: design, thermal modeling, and preliminary testing.

PubMed

Kim, Sung-Jin; Reidy, Shaelah M; Block, Bruce P; Wise, Kensall D; Zellers, Edward T; Kurabayashi, Katsuo

2010-07-07

In comprehensive two-dimensional gas chromatography (GC x GC), a modulator is placed at the juncture between two separation columns to focus and re-inject eluting mixture components, thereby enhancing the resolution and the selectivity of analytes. As part of an effort to develop a microGC x microGC prototype, in this report we present the design, fabrication, thermal operation, and initial testing of a two-stage microscale thermal modulator (microTM). The microTM contains two sequential serpentine Pyrex-on-Si microchannels (stages) that cryogenically trap analytes eluting from the first-dimension column and thermally inject them into the second-dimension column in a rapid, programmable manner. For each modulation cycle (typically 5 s for cooling with refrigeration work of 200 J and 100 ms for heating at 10 W), the microTM is kept approximately at -50 degrees C by a solid-state thermoelectric cooling unit placed within a few tens of micrometres of the device, and heated to 250 degrees C at 2800 degrees C s(-1) by integrated resistive microheaters and then cooled back to -50 degrees C at 250 degrees C s(-1). Thermal crosstalk between the two stages is less than 9%. A lumped heat transfer model is used to analyze the device design with respect to the rates of heating and cooling, power dissipation, and inter-stage thermal crosstalk as a function of Pyrex-membrane thickness, air-gap depth, and stage separation distance. Experimental results are in agreement with trends predicted by the model. Preliminary tests using a conventional capillary column interfaced to the microTM demonstrate the capability for enhanced sensitivity and resolution as well as the modulation of a mixture of alkanes.

Sequentially reweighted TV minimization for CT metal artifact reduction.

PubMed

Zhang, Xiaomeng; Xing, Lei

2013-07-01

Metal artifact reduction has long been an important topic in x-ray CT image reconstruction. In this work, the authors propose an iterative method that sequentially minimizes a reweighted total variation (TV) of the image and produces substantially artifact-reduced reconstructions. A sequentially reweighted TV minimization algorithm is proposed to fully exploit the sparseness of image gradients (IG). The authors first formulate a constrained optimization model that minimizes a weighted TV of the image, subject to the constraint that the estimated projection data are within a specified tolerance of the available projection measurements, with image non-negativity enforced. The authors then solve a sequence of weighted TV minimization problems where weights used for the next iteration are computed from the current solution. Using the complete projection data, the algorithm first reconstructs an image from which a binary metal image can be extracted. Forward projection of the binary image identifies metal traces in the projection space. The metal-free background image is then reconstructed from the metal-trace-excluded projection data by employing a different set of weights. Each minimization problem is solved using a gradient method that alternates projection-onto-convex-sets and steepest descent. A series of simulation and experimental studies are performed to evaluate the proposed approach. Our study shows that the sequentially reweighted scheme, by altering a single parameter in the weighting function, flexibly controls the sparsity of the IG and reconstructs artifacts-free images in a two-stage process. It successfully produces images with significantly reduced streak artifacts, suppressed noise and well-preserved contrast and edge properties. The sequentially reweighed TV minimization provides a systematic approach for suppressing CT metal artifacts. The technique can also be generalized to other "missing data" problems in CT image reconstruction.

Optimization of the superconducting phase of hydrogen sulfide

NASA Astrophysics Data System (ADS)

Degtyarenko, N. N.; Masur, E. A.

2015-12-01

The electron and phonon spectra, as well as the densities of electron and phonon states of the SH3 phase and the stable orthorhombic structure of hydrogen sulfide SH2, are calculated for the pressure interval 100-225 GPa. It is found that the I4/ mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH3 phase. Sequential stages for obtaining and conservation of the SH2 phase are proposed. The properties of two (SH2 and SH3) superconducting phases of hydrogen sulfide are compared.

Using Nazarov Electrocyclization to Stage Chemoselective [1,2]-Migrations: Stereoselective Synthesis of Functionalized Cyclopentenones

PubMed Central

Lebœuf, David; Huang, Jie; Gandon, Vincent

2012-01-01

Highly functionalized cyclopentenones are prepared stereospecifically based on a chemoselective copper(II)-mediated Nazarov/Wagner-Meerwein rearrangement sequence. After the initial 4π electrocyclization, this reaction involves two sequential [1,2]-migrations depending upon both migratory ability and steric bulk of the substituents at C1 and C5. This sequence can be achieved by using a catalytic quantity of copper(II) in combination with a weak Lewis acid. The mechanism of the reaction is also supported by DFT computations. PMID:21953873

Prediction of human breast and colon cancers from imbalanced data using nearest neighbor and support vector machines.

PubMed

Majid, Abdul; Ali, Safdar; Iqbal, Mubashar; Kausar, Nabeela

2014-03-01

This study proposes a novel prediction approach for human breast and colon cancers using different feature spaces. The proposed scheme consists of two stages: the preprocessor and the predictor. In the preprocessor stage, the mega-trend diffusion (MTD) technique is employed to increase the samples of the minority class, thereby balancing the dataset. In the predictor stage, machine-learning approaches of K-nearest neighbor (KNN) and support vector machines (SVM) are used to develop hybrid MTD-SVM and MTD-KNN prediction models. MTD-SVM model has provided the best values of accuracy, G-mean and Matthew's correlation coefficient of 96.71%, 96.70% and 71.98% for cancer/non-cancer dataset, breast/non-breast cancer dataset and colon/non-colon cancer dataset, respectively. We found that hybrid MTD-SVM is the best with respect to prediction performance and computational cost. MTD-KNN model has achieved moderately better prediction as compared to hybrid MTD-NB (Naïve Bayes) but at the expense of higher computing cost. MTD-KNN model is faster than MTD-RF (random forest) but its prediction is not better than MTD-RF. To the best of our knowledge, the reported results are the best results, so far, for these datasets. The proposed scheme indicates that the developed models can be used as a tool for the prediction of cancer. This scheme may be useful for study of any sequential information such as protein sequence or any nucleic acid sequence. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A phase 1 study to evaluate effect of food on veliparib pharmacokinetics and relative bioavailability in subjects with solid tumors.

PubMed

Mostafa, Nael M; Chiu, Yi-Lin; Rosen, Lee S; Bessudo, Alberto; Kovacs, Xenia; Giranda, Vincent L

2014-09-01

A phase 1 study was conducted to evaluate the bioavailability and food effect of a new veliparib formulation in subjects with solid tumors. Subjects (planned: Stage I, N = 20; Stage II, N = 16) received four regimens of a single oral dose of veliparib utilizing a group-sequential design. Subjects were administered single doses of 40 mg veliparib supplied as four 10 mg current formulation, four 10 mg new formulation and one 40 mg new formulation under fasting conditions and under non-fasting conditions. Serial blood samples were collected for the determination of veliparib pharmacokinetics. At the end of Stage I, the relative bioavailability between each pair of regimens was assessed by a two one-sided tests procedure from the analyses of the natural logarithms of C(max) and AUC. A 92.7 % confidence interval within the 0.80-1.25 range between each regimen pair determined bioequivalence. Four 10 mg current formulation capsules, four 10 mg new formulation and one 40 mg new formulation were bioequivalent with respect to C(max) and AUC under fasting conditions. The administration of a high-fat meal did not have a significant effect on AUC and only caused a slight decrease in veliparib C(max) (17 %) and a delay of approximately 1 h in T(max). The 40 mg new capsule was bioequivalent to currently used formulation. Food had no effect on the extent of veliparib absorption and only a small (17 %) decrease in peak exposure of veliparib.

Treatment results of nasopharyngeal carcinoma: a 15-year single institutional experience.

PubMed

Khademi, Bijan; Mahmoodi, Jalal; Omidvari, Shapour; Mohammadianpanah, Mohammad

2006-06-01

Nasopharyngeal Carcinoma (NPC) is a common malignant neoplasm of the head and neck that occurs most commonly in people in the South Eastern Asia but its condition in Iran is not much clear. In this retrospective study, we evaluated the treatment characteristics determining the outcome in patients with NPC. In this retrospective study, we reviewed the records of one hundred and seven patients with biopsy proven diagnosis of NPC who were referred to the radiation oncology department, Nemazee Hospital, Shiraz University of Medical Sciences, Iran, during the time period from January 1985 to December 2000. Eightyfive patients (79.4%) received 60-70Gy radiation (1.8- 2Gy/fraction, one fraction per day, and 5 fractions per week). Sixty-two patients (57.5%) received radiotherapy combined with adjuvant chemotherapy which consisted of cisplatin and 5-fluorouracil. Eighty-six patients (80.4%) had WHO II-III histopathologic diagnosis. According to the AJCC 1997 staging system, 4 (3.6%), 3 (2.7%), 33 (30.8%) and 67 (62%) patients were in stages I, II, III and IV, respectively. With a median follow-up of 12 months, the 2-year overall and disease-free survival rates were 35% and 21%, respectively. According to the multivariate analysis for overall survival, patients under 40 years had a better prognosis (p=0.041). Node stage and stage of disease were significant prognostic factors (p=0.0001). On multivariate analysis for disease-free survival, age and node stage were significant prognostic factors. The patients who received more than 60Gy radiation had a better prognosis (p=0.02), however; sequential adjuvant chemotherapy had no impact on survival and response (p=0.6). Our experience confirmed earlier reports showing poor outcomes for locoregionally advanced nasopharyngeal carcinomas. This study failed to demonstrate improvement in the outcome regarding overall and disease-free survival by adding sequential adjuvant chemotherapy after radiotherapy for patients with advanced NPC.

Parallelization of sequential Gaussian, indicator and direct simulation algorithms

NASA Astrophysics Data System (ADS)

Nunes, Ruben; Almeida, José A.

2010-08-01

Improving the performance and robustness of algorithms on new high-performance parallel computing architectures is a key issue in efficiently performing 2D and 3D studies with large amount of data. In geostatistics, sequential simulation algorithms are good candidates for parallelization. When compared with other computational applications in geosciences (such as fluid flow simulators), sequential simulation software is not extremely computationally intensive, but parallelization can make it more efficient and creates alternatives for its integration in inverse modelling approaches. This paper describes the implementation and benchmarking of a parallel version of the three classic sequential simulation algorithms: direct sequential simulation (DSS), sequential indicator simulation (SIS) and sequential Gaussian simulation (SGS). For this purpose, the source used was GSLIB, but the entire code was extensively modified to take into account the parallelization approach and was also rewritten in the C programming language. The paper also explains in detail the parallelization strategy and the main modifications. Regarding the integration of secondary information, the DSS algorithm is able to perform simple kriging with local means, kriging with an external drift and collocated cokriging with both local and global correlations. SIS includes a local correction of probabilities. Finally, a brief comparison is presented of simulation results using one, two and four processors. All performance tests were carried out on 2D soil data samples. The source code is completely open source and easy to read. It should be noted that the code is only fully compatible with Microsoft Visual C and should be adapted for other systems/compilers.

Conditional estimation using prior information in 2-stage group sequential designs assuming asymptotic normality when the trial terminated early.

PubMed

Shimura, Masashi; Maruo, Kazushi; Gosho, Masahiko

2018-04-23

Two-stage designs are widely used to determine whether a clinical trial should be terminated early. In such trials, a maximum likelihood estimate is often adopted to describe the difference in efficacy between the experimental and reference treatments; however, this method is known to display conditional bias. To reduce such bias, a conditional mean-adjusted estimator (CMAE) has been proposed, although the remaining bias may be nonnegligible when a trial is stopped for efficacy at the interim analysis. We propose a new estimator for adjusting the conditional bias of the treatment effect by extending the idea of the CMAE. This estimator is calculated by weighting the maximum likelihood estimate obtained at the interim analysis and the effect size prespecified when calculating the sample size. We evaluate the performance of the proposed estimator through analytical and simulation studies in various settings in which a trial is stopped for efficacy or futility at the interim analysis. We find that the conditional bias of the proposed estimator is smaller than that of the CMAE when the information time at the interim analysis is small. In addition, the mean-squared error of the proposed estimator is also smaller than that of the CMAE. In conclusion, we recommend the use of the proposed estimator for trials that are terminated early for efficacy or futility. Copyright © 2018 John Wiley & Sons, Ltd.

IDENTIFICATION OF SOURCES AND ESTIMATION OF EMISSION PROFILES FROM HIGHLY TIME-RESOLVED POLLUTANT MEASUREMENTS IN TAMPA, FL

EPA Science Inventory

Aerosol slurry samples were collected at 30-min intervals for sequential 1-month periods at each of two sites (Sydney and "Dairy") in the Tampa Bay area during the 2002 Bay Regional Atmospheric Chemistry Experiment using the University of Maryland Semicontinuous Elements in Aeros...

Early stages of figure-ground segregation during perception of the face-vase.

PubMed

Pitts, Michael A; Martínez, Antígona; Brewer, James B; Hillyard, Steven A

2011-04-01

The temporal sequence of neural processes supporting figure-ground perception was investigated by recording ERPs associated with subjects' perceptions of the face-vase figure. In Experiment 1, subjects continuously reported whether they perceived the face or the vase as the foreground figure by pressing one of two buttons. Each button press triggered a probe flash to the face region, the vase region, or the borders between the two. The N170/vertex positive potential (VPP) component of the ERP elicited by probes to the face region was larger when subjects perceived the faces as figure. Preceding the N170/VPP, two additional components were identified. First, when the borders were probed, ERPs differed in amplitude as early as 110 msec after probe onset depending on subjects' figure-ground perceptions. Second, when the face or vase regions were probed, ERPs were more positive (at ∼ 150-200 msec) when that region was perceived as figure versus background. These components likely reflect an early "border ownership" stage, and a subsequent "figure-ground segregation" stage of processing. To explore the influence of attention on these stages of processing, two additional experiments were conducted. In Experiment 2, subjects selectively attended to the face or vase region, and the same early ERP components were again produced. In Experiment 3, subjects performed an identical selective attention task, but on a display lacking distinctive figure-ground borders, and neither of the early components were produced. Results from these experiments suggest sequential stages of processing underlying figure-ground perception, each which are subject to modifications by selective attention.

Early Stages of Figure–Ground Segregation during Perception of the Face–Vase

PubMed Central

Pitts, Michael A.; Martínez, Antígona; Brewer, James B.; Hillyard, Steven A.

2011-01-01

The temporal sequence of neural processes supporting figure–ground perception was investigated by recording ERPs associated with subjects’ perceptions of the face–vase figure. In Experiment 1, subjects continuously reported whether they perceived the face or the vase as the foreground figure by pressing one of two buttons. Each button press triggered a probe flash to the face region, the vase region, or the borders between the two. The N170/vertex positive potential (VPP) component of the ERP elicited by probes to the face region was larger when subjects perceived the faces as figure. Preceding the N170/VPP, two additional components were identified. First, when the borders were probed, ERPs differed in amplitude as early as 110 msec after probe onset depending on subjects’ figure–ground perceptions. Second, when the face or vase regions were probed, ERPs were more positive (at ~150–200 msec) when that region was perceived as figure versus background. These components likely reflect an early “border ownership” stage, and a subsequent “figure–ground segregation” stage of processing. To explore the influence of attention on these stages of processing, two additional experiments were conducted. In Experiment 2, subjects selectively attended to the face or vase region, and the same early ERP components were again produced. In Experiment 3, subjects performed an identical selective attention task, but on a display lacking distinctive figure–ground borders, and neither of the early components were produced. Results from these experiments suggest sequential stages of processing underlying figure–ground perception, each which are subject to modifications by selective attention. PMID:20146604

The effect of sequential therapy with lansoprazole and ecabet sodium in treating iatrogenic gastric ulcer after endoscopic submucosal dissection: a randomized prospective study.

PubMed

Ahn, Ji Yong; Choi, Chang Hwan; Lee, Jang Wook; Park, Sung Jin; Kim, Jeong Wook; Chang, Sae Kyung; Han, Seung Bong

2015-02-01

Ecabet sodium (ES) is a new non-systemic anti-ulcer agent belonging to the category of gastroprotective agents. In this study we aimed to compare the efficacy of a combination therapy with lansoprazole (LS) followed by ES with LS alone in treating endoscopic submucosal dissection (ESD)-induced iatrogenic gastric ulcers. Patients diagnosed with gastric adenomas or early gastric cancer were randomly divided into either the LS group (30 mg once daily for 4 weeks; n = 45) or the LS + ES group (LS 30 mg once daily for one week followed by ES 1500 mg twice daily for 3 weeks; n = 45). Four weeks after ESD, a follow-up endoscopy was conducted to evaluate the proportions of ulcer reduction and ulcer stages in the two groups. In all, 79 patients were included in the final analyses. Both treatment modalities were well-tolerated in most patients, with a drug compliance of over 80%. There were no significant differences between the two groups in terms of the proportions of ulcer reduction (0.9503 ± 0.1215 in the LS group vs 0.9192 ± 0.0700 in the LS + ES group, P = 0.169) or ulcer stage (P = 0.446). The prevalence of adverse events related to drugs and bleeding were also similar between the two groups. Sequential therapy with LS + ES is as effective as LS alone against ESD-induced gastric ulcers. © 2014 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Acute Toxicity and Efficacy of Current Medical Countermeasures against VM in Guinea Pigs: A Comparison to VX and VR

DTIC Science & Technology

2013-05-01

and diazepam with and without pretreatment with pyridostigmine bromide . The 24 hr median lethal dose (MLD) of VM was determined using a sequential... pyridostigmine bromide . The 24 hr median lethal dose (MLD) of VM was determined using a sequential stage approach. The efficacy of medical...with and without pyridostigmine bromide (PB) pretreatment against lethal intoxication with VM, VR or VX. Methods Animals: Adult male Hartley

Assessment of in vitro cyto/genotoxicity of sequentially treated electroplating effluent on the human hepatocarcinoma HuH-7 cell line.

PubMed

Naik, Umesh Chandra; Das, Mihir Tanay; Sauran, Swati; Thakur, Indu Shekhar

2014-03-01

The present study compares in vitro toxicity of electroplating effluent after the batch treatment process with that obtained after the sequential treatment process. Activated charcoal prepared from sugarcane bagasse through chemical carbonization, and tolerant indigenous bacteria, Bacillus sp. strain IST105, were used individually and sequentially for the treatment of electroplating effluent. The sequential treatment involving activated charcoal followed by bacterial treatment removed 99% of Cr(VI) compared with the batch processes, which removed 40% (charcoal) and 75% (bacteria), respectively. Post-treatment in vitro cyto/genotoxicity was evaluated by the MTT test and the comet assay in human HuH-7 hepatocarcinoma cells. The sequentially treated sample showed an increase in LC50 value with a 6-fold decrease in comet-assay DNA migration compared with that of untreated samples. A significant decrease in DNA migration and an increase in LC50 value of treated effluent proved the higher effectiveness of the sequential treatment process over the individual batch processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Orbit Determination Using Vinti’s Solution

DTIC Science & Technology

2016-09-15

Surveillance Network STK Systems Tool Kit TBP Two Body Problem TLE Two-line Element Set xv Acronym Definition UKF Unscented Kalman Filter WPAFB Wright...simplicity, stability, and speed. On the other hand, Kalman filters would be best suited for sequential estimation of stochastic or random components of a...be likened to how an Unscented Kalman Filter samples a system’s nonlinearities directly, avoiding linearizing the dynamics in the partials matrices

Surgical Management of Simultaneous Anterior Cruciate Ligament and Patellar Tendon Ruptures: A Systematic Review.

PubMed

Meheux, Carlos J; Jack, Robert A; McCulloch, Patrick C; Lintner, David M; Harris, Joshua D

2017-12-28

This study performs a systematic review to determine (1) if a significant difference exists in return to preinjury activity level between one- and two-stage treatment of combined anterior cruciate ligament (ACL) and patellar tendon (PT) tears; and (2) if a significant difference exists in the number of postoperative complications between the two differing surgical treatment approaches. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and registered on PROSPERO. MEDLINE, Cochrane Central Register of Controlled Trials, SCOPUS, and Sport Discus were searched for English language level I-IV evidence studies on either one- (simultaneous) or two-stage (sequential) surgical treatment of simultaneously sustained ipsilateral ACL and PT tears. The approach to initial evaluation, diagnosis, treatment, and outcomes were qualitatively analyzed. Methodological quality assessment of all included studies was completed using the Methodological Index for Non-randomized Studies (MINORS). The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess quality of evidence and provide strength of recommendation. Statistical analyses were done using Fischer's exact test. Eleven articles (18 patients; 83% males; mean age, 31.1 ± 10.1 years; mean follow-up, 2.2 ± 1.7 years; and mean MINORS 7.8/16) were analyzed. Eight patients had a one-stage procedure (primary PT repair and ACL reconstruction), and 10 patients underwent a two-stage procedure (primary PT repair first followed by ACL reconstruction) with mean 28 ± 45.7 weeks (5 weeks-3 years) between surgeries. The rate for return to preinjury activity level after surgery was not significantly different between one- (88%) and two-stage (100%) ( p  = 0.444). There was a significantly higher complication rate ( p  = 0.023) in the one-stage (stiffness, instability, and patella baja) versus two-stage surgery (no complications). There was no significant difference in return to preinjury activity level between one- and two-stage PT repair and ACL reconstruction. However, the one-stage combined surgery had a significantly higher complication rate compared with two-stage surgery. The level of evidence is IV. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

An EEG Investigation of the Differences in the Hemispheric Specialization of Formal and Concrete Operational Persons.

ERIC Educational Resources Information Center

Dilling, Richard A.; And Others

This study attempts to raise and answer the question as to whether lateral specialization of the brain could explain some of the differences in persons at different stages of intellectual development from birth to adulthood according to Piaget's theory of individual development via sequential, qualitatively different stages.…

Single-pipetting microfluidic assay device for rapid detection of Salmonella from poultry package.

PubMed

Fronczek, Christopher F; You, David J; Yoon, Jeong-Yeol

2013-02-15

A direct, sensitive, near-real-time, handheld optical immunoassay device was developed to detect Salmonella typhimurium in the naturally occurring liquid from fresh poultry packages (hereafter "chicken matrix"), with just single pipetting of sample (i.e., no filtration, culturing and/or isolation, thus reducing the assay time and the error associated with them). Carboxylated, polystyrene microparticles were covalently conjugated with anti-Salmonella, and the immunoagglutination due to the presence of Salmonella was detected by reading the Mie scatter signals from the microfluidic channels using a handheld device. The presence of chicken matrix did not affect the light scatter signal, since the optical parameters (particle size d, wavelength of incident light λ and scatter angle θ) were optimized to minimize the effect of sample matrix (animal tissues and blood proteins, etc.). The sample was loaded into a microfluidic chip that was split into two channels, one pre-loaded with vacuum-dried, antibody-conjugated particles and the other with vacuum-dried, bovine serum albumin-conjugated particles. This eliminated the need for a separate negative control, effectively minimizing chip-to-chip and sample-to-sample variations. Particles and the sample were diffused in-channel through chemical agitation by Tween 80, also vacuum-dried within the microchannels. Sequential mixing of the sample to the reagents under a strict laminar flow condition synergistically improved the reproducibility and linearity of the assay. In addition, dried particles were shown to successfully detect lower Salmonella concentrations for up to 8 weeks. The handheld device contains simplified circuitry eliminating unnecessary adjustment stages, providing a stable signal, thus maximizing sensitivity. Total assay time was 10 min, and the detection limit 10 CFU mL(-1) was observed in all matrices, demonstrating the suitability of this device for field assays. Copyright © 2012 Elsevier B.V. All rights reserved.

Photoluminescence upconversion at GaAs /InGa P2 interfaces driven by a sequential two-photon absorption mechanism

NASA Astrophysics Data System (ADS)

Hylton, N. P.; Hinrichsen, T. F.; Vaquero-Stainer, A. R.; Yoshida, M.; Pusch, A.; Hopkinson, M.; Hess, O.; Phillips, C. C.; Ekins-Daukes, N. J.

2016-06-01

This paper reports on the results of an investigation into the nature of photoluminescence upconversion at GaAs /InGa P2 interfaces. Using a dual-beam excitation experiment, we demonstrate that the upconversion in our sample proceeds via a sequential two-photon optical absorption mechanism. Measurements of photoluminescence and upconversion photoluminescence revealed evidence of the spatial localization of carriers in the InGa P2 material, arising from partial ordering of the InGa P2 . We also observed the excitation of a two-dimensional electron gas at the GaAs /InGa P2 heterojunction that manifests as a high-energy shoulder in the GaAs photoluminescence spectrum. Furthermore, the results of upconversion photoluminescence excitation spectroscopy demonstrate that the photon energy onset of upconversion luminescence coincides with the energy of the two-dimensional electron gas at the GaAs /InGa P2 interface, suggesting that charge accumulation at the interface can play a crucial role in the upconversion process.

Recommendations for choosing an analysis method that controls Type I error for unbalanced cluster sample designs with Gaussian outcomes.

PubMed

Johnson, Jacqueline L; Kreidler, Sarah M; Catellier, Diane J; Murray, David M; Muller, Keith E; Glueck, Deborah H

2015-11-30

We used theoretical and simulation-based approaches to study Type I error rates for one-stage and two-stage analytic methods for cluster-randomized designs. The one-stage approach uses the observed data as outcomes and accounts for within-cluster correlation using a general linear mixed model. The two-stage model uses the cluster specific means as the outcomes in a general linear univariate model. We demonstrate analytically that both one-stage and two-stage models achieve exact Type I error rates when cluster sizes are equal. With unbalanced data, an exact size α test does not exist, and Type I error inflation may occur. Via simulation, we compare the Type I error rates for four one-stage and six two-stage hypothesis testing approaches for unbalanced data. With unbalanced data, the two-stage model, weighted by the inverse of the estimated theoretical variance of the cluster means, and with variance constrained to be positive, provided the best Type I error control for studies having at least six clusters per arm. The one-stage model with Kenward-Roger degrees of freedom and unconstrained variance performed well for studies having at least 14 clusters per arm. The popular analytic method of using a one-stage model with denominator degrees of freedom appropriate for balanced data performed poorly for small sample sizes and low intracluster correlation. Because small sample sizes and low intracluster correlation are common features of cluster-randomized trials, the Kenward-Roger method is the preferred one-stage approach. Copyright © 2015 John Wiley & Sons, Ltd.

Optimization of multi-stage dynamic treatment regimes utilizing accumulated data.

PubMed

Huang, Xuelin; Choi, Sangbum; Wang, Lu; Thall, Peter F

2015-11-20

In medical therapies involving multiple stages, a physician's choice of a subject's treatment at each stage depends on the subject's history of previous treatments and outcomes. The sequence of decisions is known as a dynamic treatment regime or treatment policy. We consider dynamic treatment regimes in settings where each subject's final outcome can be defined as the sum of longitudinally observed values, each corresponding to a stage of the regime. Q-learning, which is a backward induction method, is used to first optimize the last stage treatment then sequentially optimize each previous stage treatment until the first stage treatment is optimized. During this process, model-based expectations of outcomes of late stages are used in the optimization of earlier stages. When the outcome models are misspecified, bias can accumulate from stage to stage and become severe, especially when the number of treatment stages is large. We demonstrate that a modification of standard Q-learning can help reduce the accumulated bias. We provide a computational algorithm, estimators, and closed-form variance formulas. Simulation studies show that the modified Q-learning method has a higher probability of identifying the optimal treatment regime even in settings with misspecified models for outcomes. It is applied to identify optimal treatment regimes in a study for advanced prostate cancer and to estimate and compare the final mean rewards of all the possible discrete two-stage treatment sequences. Copyright © 2015 John Wiley & Sons, Ltd.

Comparison and Field Validation of Binomial Sampling Plans for Oligonychus perseae (Acari: Tetranychidae) on Hass Avocado in Southern California.

PubMed

Lara, Jesus R; Hoddle, Mark S

2015-08-01

Oligonychus perseae Tuttle, Baker, & Abatiello is a foliar pest of 'Hass' avocados [Persea americana Miller (Lauraceae)]. The recommended action threshold is 50-100 motile mites per leaf, but this count range and other ecological factors associated with O. perseae infestations limit the application of enumerative sampling plans in the field. Consequently, a comprehensive modeling approach was implemented to compare the practical application of various binomial sampling models for decision-making of O. perseae in California. An initial set of sequential binomial sampling models were developed using three mean-proportion modeling techniques (i.e., Taylor's power law, maximum likelihood, and an empirical model) in combination with two-leaf infestation tally thresholds of either one or two mites. Model performance was evaluated using a robust mite count database consisting of >20,000 Hass avocado leaves infested with varying densities of O. perseae and collected from multiple locations. Operating characteristic and average sample number results for sequential binomial models were used as the basis to develop and validate a standardized fixed-size binomial sampling model with guidelines on sample tree and leaf selection within blocks of avocado trees. This final validated model requires a leaf sampling cost of 30 leaves and takes into account the spatial dynamics of O. perseae to make reliable mite density classifications for a 50-mite action threshold. Recommendations for implementing this fixed-size binomial sampling plan to assess densities of O. perseae in commercial California avocado orchards are discussed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RACE/A: An Architectural Account of the Interactions between Learning, Task Control, and Retrieval Dynamics

ERIC Educational Resources Information Center

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…

A novel procedure for Rubidium separation and its isotope measurements on geological samples by MC-ICP-MS

NASA Astrophysics Data System (ADS)

Ma, J.; Zhang, Z.; Wei, G.; Zhang, L.

2017-12-01

A method including a novel column Rb separation procedure and high-precision Rb isotope measurement in geological materials by using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in standard-sample-bracketing (SSB) mode has been developed. Sr-Spec resin was employed, in which the distribution coefficients for Rb, K, Ba and Sr are different in nitric acid, to sequentially separate them from the matrix. The dissolved samples were loaded on the column in 3 M HNO3, the main matrix such as Al, Ca, Fe, Mg, Mn and Na were removed by rinsing with 4.5 mL HNO3, Rb and K were then sequentially eluted by 3 M HNO3 in different volumes. After that, Ba was eluted by 8 M HNO3, and Sr was finally eluted by Milli-Q water. This enable us to collect the pure Rb, K, Ba and Sr one by one with recovery close to 100% for their isotopic compositions measurement on MC-ICP-MS. We here focus on Rb isotope measurement. The measurement using MC-ICP-MS yielded an internal precision for δ87Rb of < ± 0.03‰ (2SE), and the external precision was generally better than ± 0.06‰ (2SD) based on the long-term results of the Rb standard solutions NIST SRM 984. A series of geological rock standards, were analyzed using this method, and the results indicate significant Rb isotope differences in different geologic materials. This will provide a powerful tool to investigate Rb isotope fractionation during geological processes.Based on this method, Rb isotope compositions from a basaltic weathering profile were carried out. The data show the lighter Rb (85Rb) isotope is preferentially leached from the weathering profile and remains heavy Rb isotope (87Rb) in the weathered residues during the incipient weathering stage. From the moderate to advanced weathering stage, the significant variations of Rb isotope were observed and multiple factors, such as leaching, adsorption, desorption, and precipitation, should play important role in fractionating Rb isotope.

Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size determination

NASA Astrophysics Data System (ADS)

Koziel, Slawomir; Bekasiewicz, Adrian

2018-02-01

In this article, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement for yielding the optimal designs at the high-fidelity electromagnetic (EM) simulation model level. For the sake of computational efficiency, the first step is realized at the level of a low-fidelity (coarse-discretization) EM model by sequential construction and relocation of small design space segments (patches) in order to create a path connecting the extreme Pareto front designs obtained beforehand. The second stage involves response correction techniques and local response surface approximation models constructed by reusing EM simulation data acquired in the first step. A major contribution of this work is an automated procedure for determining the patch dimensions. It allows for appropriate selection of the number of patches for each geometry variable so as to ensure reliability of the optimization process while maintaining its low cost. The importance of this procedure is demonstrated by comparing it with uniform patch dimensions.

Novel Designs of Quantum Reversible Counters

NASA Astrophysics Data System (ADS)

Qi, Xuemei; Zhu, Haihong; Chen, Fulong; Zhu, Junru; Zhang, Ziyang

2016-11-01

Reversible logic, as an interesting and important issue, has been widely used in designing combinational and sequential circuits for low-power and high-speed computation. Though a significant number of works have been done on reversible combinational logic, the realization of reversible sequential circuit is still at premature stage. Reversible counter is not only an important part of the sequential circuit but also an essential part of the quantum circuit system. In this paper, we designed two kinds of novel reversible counters. In order to construct counter, the innovative reversible T Flip-flop Gate (TFG), T Flip-flop block (T_FF) and JK flip-flop block (JK_FF) are proposed. Based on the above blocks and some existing reversible gates, the 4-bit binary-coded decimal (BCD) counter and controlled Up/Down synchronous counter are designed. With the help of Verilog hardware description language (Verilog HDL), these counters above have been modeled and confirmed. According to the simulation results, our circuits' logic structures are validated. Compared to the existing ones in terms of quantum cost (QC), delay (DL) and garbage outputs (GBO), it can be concluded that our designs perform better than the others. There is no doubt that they can be used as a kind of important storage components to be applied in future low-power computing systems.

Effective Sequential Classifier Training for SVM-Based Multitemporal Remote Sensing Image Classification

NASA Astrophysics Data System (ADS)

Guo, Yiqing; Jia, Xiuping; Paull, David

2018-06-01

The explosive availability of remote sensing images has challenged supervised classification algorithms such as Support Vector Machines (SVM), as training samples tend to be highly limited due to the expensive and laborious task of ground truthing. The temporal correlation and spectral similarity between multitemporal images have opened up an opportunity to alleviate this problem. In this study, a SVM-based Sequential Classifier Training (SCT-SVM) approach is proposed for multitemporal remote sensing image classification. The approach leverages the classifiers of previous images to reduce the required number of training samples for the classifier training of an incoming image. For each incoming image, a rough classifier is firstly predicted based on the temporal trend of a set of previous classifiers. The predicted classifier is then fine-tuned into a more accurate position with current training samples. This approach can be applied progressively to sequential image data, with only a small number of training samples being required from each image. Experiments were conducted with Sentinel-2A multitemporal data over an agricultural area in Australia. Results showed that the proposed SCT-SVM achieved better classification accuracies compared with two state-of-the-art model transfer algorithms. When training data are insufficient, the overall classification accuracy of the incoming image was improved from 76.18% to 94.02% with the proposed SCT-SVM, compared with those obtained without the assistance from previous images. These results demonstrate that the leverage of a priori information from previous images can provide advantageous assistance for later images in multitemporal image classification.

Particle rejuvenation of Rao-Blackwellized sequential Monte Carlo smoothers for conditionally linear and Gaussian models

NASA Astrophysics Data System (ADS)

Nguyen, Ngoc Minh; Corff, Sylvain Le; Moulines, Éric

2017-12-01

This paper focuses on sequential Monte Carlo approximations of smoothing distributions in conditionally linear and Gaussian state spaces. To reduce Monte Carlo variance of smoothers, it is typical in these models to use Rao-Blackwellization: particle approximation is used to sample sequences of hidden regimes while the Gaussian states are explicitly integrated conditional on the sequence of regimes and observations, using variants of the Kalman filter/smoother. The first successful attempt to use Rao-Blackwellization for smoothing extends the Bryson-Frazier smoother for Gaussian linear state space models using the generalized two-filter formula together with Kalman filters/smoothers. More recently, a forward-backward decomposition of smoothing distributions mimicking the Rauch-Tung-Striebel smoother for the regimes combined with backward Kalman updates has been introduced. This paper investigates the benefit of introducing additional rejuvenation steps in all these algorithms to sample at each time instant new regimes conditional on the forward and backward particles. This defines particle-based approximations of the smoothing distributions whose support is not restricted to the set of particles sampled in the forward or backward filter. These procedures are applied to commodity markets which are described using a two-factor model based on the spot price and a convenience yield for crude oil data.

High pressure studies using two-stage diamond micro-anvils grown by chemical vapor deposition

DOE PAGES

Vohra, Yogesh K.; Samudrala, Gopi K.; Moore, Samuel L.; ...

2015-06-10

Ultra-high static pressures have been achieved in the laboratory using a two-stage micro-ball nanodiamond anvils as well as a two-stage micro-paired diamond anvils machined using a focused ion-beam system. The two-stage diamond anvils’ designs implemented thus far suffer from a limitation of one diamond anvil sliding past another anvil at extreme conditions. We describe a new method of fabricating two-stage diamond micro-anvils using a tungsten mask on a standard diamond anvil followed by microwave plasma chemical vapor deposition (CVD) homoepitaxial diamond growth. A prototype two stage diamond anvil with 300 μm culet and with a CVD diamond second stage ofmore » 50 μm in diameter was fabricated. We have carried out preliminary high pressure X-ray diffraction studies on a sample of rare-earth metal lutetium sample with a copper pressure standard to 86 GPa. Furthermore, the micro-anvil grown by CVD remained intact during indentation of gasket as well as on decompression from the highest pressure of 86 GPa.« less

Integrated Primary Care Readiness and Behaviors Scale: Development and validation in behavioral health professionals.

PubMed

Blaney, Cerissa L; Redding, Colleen A; Paiva, Andrea L; Rossi, Joseph S; Prochaska, James O; Blissmer, Bryan; Burditt, Caitlin T; Nash, Justin M; Bayley, Keri Dotson

2018-03-01

Although integrated primary care (IPC) is growing, several barriers remain. Better understanding of behavioral health professionals' (BHPs') readiness for and engagement in IPC behaviors could improve IPC research and training. This study developed measures of IPC behaviors and stage of change. The sample included 319 licensed, practicing BHPs with a range of interests and experience with IPC. Sequential measurement development procedures, with split-half cross-validation were conducted. Exploratory principal components analyses (N = 152) and confirmatory factor analyses (N = 167) yielded a 12-item scale with 2 factors: consultation/practice management (CPM) and intervention/knowledge (IK). A higher-order Integrated Primary Care Behavior Scale (IPCBS) model showed good fit to the data, and excellent internal consistencies. The multivariate analysis of variance (MANOVA) on the IPCBS demonstrated significant large-sized differences across stage and behavior groups. The IPCBS demonstrated good psychometric properties and external validation, advancing research, education, and training for IPC practice. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Occurrence and abundance of carbohydrates and amino compounds in sequentially extracted labile soil organic matter fractions.

USDA-ARS?s Scientific Manuscript database

This study aimed to investigate the content of carbohydrates and amino compounds in three labile fraction of soil organic matter (SOM). Soil samples were collected from two agricultural fields in southern Italy and the light fraction (LF), the 500–53-µm particulate organic matter (POM) and the mobil...

A Study of the Feasibility for Vocational Rehabilitation of a Perplexing Group of Mental Health Patients. Final Report.

ERIC Educational Resources Information Center

Cohen, Albert; Orzech, David

This project explored the feasibility for vocational rehabilitation of a perplexing group of patients awaiting separation from a state mental hospital. The patients were of dubious employability. The design was a series of sequential stages through which the 98 workshop participants passed, with attrition taking place at each stage. The program…

Re-Thinking Stages of Cognitive Development: An Appraisal of Connectionist Models of the Balance Scale Task

ERIC Educational Resources Information Center

Quinlan, Philip T.; van der Maas, Han L. J.; Jansen, Brenda R. J.; Booij, Olaf; Rendell, Mark

2007-01-01

The present paper re-appraises connectionist attempts to explain how human cognitive development appears to progress through a series of sequential stages. Models of performance on the Piagetian balance scale task are the focus of attention. Limitations of these models are discussed and replications and extensions to the work are provided via the…

Quantum Otto engine using a single ion and a single thermal bath

NASA Astrophysics Data System (ADS)

Biswas, Asoka; Chand, Suman

2016-05-01

Quantum heat engines employ a quantum system as the working fluid, that gives rise to large work efficiency, beyond the limit for classical heat engines. Existing proposals for implementing quantum heat engines require that the system interacts with the hot bath and the cold bath (both modelled as a classical system) in an alternative fashion and therefore assumes ability to switch off the interaction with the bath during a certain stage of the heat-cycle. However, it is not possible to decouple a quantum system from its always-on interaction with the bath without use of complex pulse sequences. It is also hard to identify two different baths at two different temperatures in quantum domain, that sequentially interact with the system. Here, we show how to implement a quantum Otto engine without requiring to decouple the bath in a sequential manner. This is done by considering a single thermal bath, coupled to a single trapped ion. The electronic degree of freedom of the ion is chosen as a two-level working fluid while the vibrational degree of freedom plays the role of the cold bath. Measuring the electronic state mimics the release of heat into the cold bath. Thus, our model is fully quantum and exhibits very large work efficiency, asymptotically close to unity.

Multidrug Resistance among New Tuberculosis Cases: Detecting Local Variation through Lot Quality-Assurance Sampling

PubMed Central

Lynn Hedt, Bethany; van Leth, Frank; Zignol, Matteo; Cobelens, Frank; van Gemert, Wayne; Viet Nhung, Nguyen; Lyepshina, Svitlana; Egwaga, Saidi; Cohen, Ted

2012-01-01

Background Current methodology for multidrug-resistant TB (MDR TB) surveys endorsed by the World Health Organization provides estimates of MDR TB prevalence among new cases at the national level. On the aggregate, local variation in the burden of MDR TB may be masked. This paper investigates the utility of applying lot quality-assurance sampling to identify geographic heterogeneity in the proportion of new cases with multidrug resistance. Methods We simulated the performance of lot quality-assurance sampling by applying these classification-based approaches to data collected in the most recent TB drug-resistance surveys in Ukraine, Vietnam, and Tanzania. We explored three classification systems—two-way static, three-way static, and three-way truncated sequential sampling—at two sets of thresholds: low MDR TB = 2%, high MDR TB = 10%, and low MDR TB = 5%, high MDR TB = 20%. Results The lot quality-assurance sampling systems identified local variability in the prevalence of multidrug resistance in both high-resistance (Ukraine) and low-resistance settings (Vietnam). In Tanzania, prevalence was uniformly low, and the lot quality-assurance sampling approach did not reveal variability. The three-way classification systems provide additional information, but sample sizes may not be obtainable in some settings. New rapid drug-sensitivity testing methods may allow truncated sequential sampling designs and early stopping within static designs, producing even greater efficiency gains. Conclusions Lot quality-assurance sampling study designs may offer an efficient approach for collecting critical information on local variability in the burden of multidrug-resistant TB. Before this methodology is adopted, programs must determine appropriate classification thresholds, the most useful classification system, and appropriate weighting if unbiased national estimates are also desired. PMID:22249242

Use of sequential endorectal US to predict the tumor response of preoperative chemoradiotherapy in rectal cancer.

PubMed

Li, Ning; Dou, Lizhou; Zhang, Yueming; Jin, Jing; Wang, Guiqi; Xiao, Qin; Li, Yexiong; Wang, Xin; Ren, Hua; Fang, Hui; Wang, Weihu; Wang, Shulian; Liu, Yueping; Song, Yongwen

2017-03-01

Accurate prediction of the response to preoperative chemoradiotherapy (CRT) potentially assists in the individualized selection of treatment. Endorectal US (ERUS) is widely used for the pretreatment staging of rectal cancer, but its use for preoperatively predicting the effects of CRT is not well evaluated because of the inflammation, necrosis, and fibrosis induced by CRT. This study assessed the value of sequential ERUS in predicting the efficacy of preoperative CRT for locally advanced rectal cancer. Forty-one patients with clinical stage II/III rectal adenocarcinoma were enrolled prospectively. Radiotherapy was delivered to the pelvis with concurrent chemotherapy of capecitabine and oxaliplatin. Total mesorectal excision was performed 6 to 8 weeks later. EUS measurements of primary tumor maximum diameter were performed before (ERUS1), during (ERUS2), and 6 to 8 weeks after (ERUS3) CRT, and the ratios of these were calculated. Correlations between ERUS values, tumor regression grade (TRG), T down-staging rate, and pathologic complete response (pCR) rate were assessed, and survival was analyzed. There was no significant correlation between ERUS2/ERUS1 and TRG. The value of ERUS3/ERUS1 correlated with pCR rate and TRG but not T down-staging rate. An ERUS3 value of 6.3 mm and ERUS3/ERUS1 of 52% were used as the cut-off for predicting pCR, and patients were divided into good and poor prognosis groups. Although not statistically significant, 3-year recurrence and survival rates of the good prognosis group were better than those of the poor prognosis group. Sequential ERUS may predict therapeutic efficacy of preoperative CRT for locally advanced rectal cancer. (Clinical trial registration number: NCT01582750.). Copyright © 2017 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Simultaneous capture and sequential detection of two malarial biomarkers on magnetic microparticles.

PubMed

Markwalter, Christine F; Ricks, Keersten M; Bitting, Anna L; Mudenda, Lwiindi; Wright, David W

2016-12-01

We have developed a rapid magnetic microparticle-based detection strategy for malarial biomarkers Plasmodium lactate dehydrogenase (pLDH) and Plasmodium falciparum histidine-rich protein II (PfHRPII). In this assay, magnetic particles functionalized with antibodies specific for pLDH and PfHRPII as well as detection antibodies with distinct enzymes for each biomarker are added to parasitized lysed blood samples. Sandwich complexes for pLDH and PfHRPII form on the surface of the magnetic beads, which are washed and sequentially re-suspended in detection enzyme substrate for each antigen. The developed simultaneous capture and sequential detection (SCSD) assay detects both biomarkers in samples as low as 2.0parasites/µl, an order of magnitude below commercially available ELISA kits, has a total incubation time of 35min, and was found to be reproducible between users over time. This assay provides a simple and efficient alternative to traditional 96-well plate ELISAs, which take 5-8h to complete and are limited to one analyte. Further, the modularity of the magnetic bead-based SCSD ELISA format could serve as a platform for application to other diseases for which multi-biomarker detection is advantageous. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Infrared target tracking via weighted correlation filter

NASA Astrophysics Data System (ADS)

He, Yu-Jie; Li, Min; Zhang, JinLi; Yao, Jun-Ping

2015-11-01

Design of an effective target tracker is an important and challenging task for many applications due to multiple factors which can cause disturbance in infrared video sequences. In this paper, an infrared target tracking method under tracking by detection framework based on a weighted correlation filter is presented. This method consists of two parts: detection and filtering. For the detection stage, we propose a sequential detection method for the infrared target based on low-rank representation. For the filtering stage, a new multi-feature weighted function which fuses different target features is proposed, which takes the importance of the different regions into consideration. The weighted function is then incorporated into a correlation filter to compute a confidence map more accurately, in order to indicate the best target location based on the detection results obtained from the first stage. Extensive experimental results on different video sequences demonstrate that the proposed method performs favorably for detection and tracking compared with baseline methods in terms of efficiency and accuracy.

A sequential test for assessing observed agreement between raters.

PubMed

Bersimis, Sotiris; Sachlas, Athanasios; Chakraborti, Subha

2018-01-01

Assessing the agreement between two or more raters is an important topic in medical practice. Existing techniques, which deal with categorical data, are based on contingency tables. This is often an obstacle in practice as we have to wait for a long time to collect the appropriate sample size of subjects to construct the contingency table. In this paper, we introduce a nonparametric sequential test for assessing agreement, which can be applied as data accrues, does not require a contingency table, facilitating a rapid assessment of the agreement. The proposed test is based on the cumulative sum of the number of disagreements between the two raters and a suitable statistic representing the waiting time until the cumulative sum exceeds a predefined threshold. We treat the cases of testing two raters' agreement with respect to one or more characteristics and using two or more classification categories, the case where the two raters extremely disagree, and finally the case of testing more than two raters' agreement. The numerical investigation shows that the proposed test has excellent performance. Compared to the existing methods, the proposed method appears to require significantly smaller sample size with equivalent power. Moreover, the proposed method is easily generalizable and brings the problem of assessing the agreement between two or more raters and one or more characteristics under a unified framework, thus providing an easy to use tool to medical practitioners. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent developments in biohythane production from household food wastes: A review.

PubMed

Bolzonella, David; Battista, Federico; Cavinato, Cristina; Gottardo, Marco; Micolucci, Federico; Lyberatos, Gerasimos; Pavan, Paolo

2018-06-01

Biohythane is a hydrogen-methane blend with hydrogen concentration between 10 and 30% v/v. It can be produced from different organic substrates by two sequential anaerobic stages: a dark fermentation step followed by a second an anaerobic digestion step, for hydrogen and methane production, respectively. The advantages of this blend compared to either hydrogen or methane, as separate biofuels, are first presented in this work. The two-stage anaerobic process and the main operative parameters are then discussed. Attention is focused on the production of biohythane from household food wastes, one of the most abundant organic substrate available for anaerobic digestion: the main milestones and the future trends are exposed. In particular, the possibility to co-digest food wastes and sewage sludge to improve the process yield is discussed. Finally, the paper illustrates the developments of biohythane application in the automotive sector as well as its reduced environmental burden. Copyright © 2018 Elsevier Ltd. All rights reserved.

An apparatus for sequentially combining microvolumes of reagents by infrasonic mixing.

PubMed

Camien, M N; Warner, R C

1984-05-01

A method employing high-speed infrasonic mixing for obtaining timed samples for following the progress of a moderately rapid chemical reaction is described. Drops of 10 to 50 microliter each of two reagents are mixed to initiate the reaction, followed, after a measured time interval, by mixing with a drop of a third reagent to quench the reaction. The method was developed for measuring the rate of denaturation of covalently closed, circular DNA in NaOH at several temperatures. For this purpose the timed samples were analyzed by analytical ultracentrifugation. The apparatus was tested by determination of the rate of hydrolysis of 2,4-dinitrophenyl acetate in an alkaline buffer. The important characteristics of the method are (i) it requires very small volumes of sample and reagents; (ii) the components of the reaction mixture are pre-equilibrated and mixed with no transfer outside the prescribed constant temperature environment; (iii) the mixing is very rapid; and (iv) satisfactorily precise measurements of relatively short time intervals (approximately 2 sec minimum) between sequential mixings of the components are readily obtainable.

Split Flow Online Solid-Phase Extraction Coupled with Inductively Coupled Plasma Mass Spectrometry System for One-Shot Data Acquisition of Quantification and Recovery Efficiency.

PubMed

Furukawa, Makoto; Takagai, Yoshitaka

2016-10-04

Online solid-phase extraction (SPE) coupled with inductively coupled plasma mass spectrometry (ICPMS) is a useful tool in automatic sequential analysis. However, it cannot simultaneously quantify the analytical targets and their recovery percentages (R%) in one-shot samples. We propose a system that simultaneously acquires both data in a single sample injection. The main flowline of the online solid-phase extraction is divided into main and split flows. The split flow line (i.e., bypass line), which circumvents the SPE column, was placed on the main flow line. Under program-controlled switching of the automatic valve, the ICPMS sequentially measures the targets in a sample before and after column preconcentration and determines the target concentrations and the R% on the SPE column. This paper describes the system development and two demonstrations to exhibit the analytical significance, i.e., the ultratrace amounts of radioactive strontium ( 90 Sr) using commercial Sr-trap resin and multielement adsorbability on the SPE column. This system is applicable to other flow analyses and detectors in online solid phase extraction.

An evaluation of inferential procedures for adaptive clinical trial designs with pre-specified rules for modifying the sample size.

PubMed

Levin, Gregory P; Emerson, Sarah C; Emerson, Scott S

2014-09-01

Many papers have introduced adaptive clinical trial methods that allow modifications to the sample size based on interim estimates of treatment effect. There has been extensive commentary on type I error control and efficiency considerations, but little research on estimation after an adaptive hypothesis test. We evaluate the reliability and precision of different inferential procedures in the presence of an adaptive design with pre-specified rules for modifying the sampling plan. We extend group sequential orderings of the outcome space based on the stage at stopping, likelihood ratio statistic, and sample mean to the adaptive setting in order to compute median-unbiased point estimates, exact confidence intervals, and P-values uniformly distributed under the null hypothesis. The likelihood ratio ordering is found to average shorter confidence intervals and produce higher probabilities of P-values below important thresholds than alternative approaches. The bias adjusted mean demonstrates the lowest mean squared error among candidate point estimates. A conditional error-based approach in the literature has the benefit of being the only method that accommodates unplanned adaptations. We compare the performance of this and other methods in order to quantify the cost of failing to plan ahead in settings where adaptations could realistically be pre-specified at the design stage. We find the cost to be meaningful for all designs and treatment effects considered, and to be substantial for designs frequently proposed in the literature. © 2014, The International Biometric Society.

Lexical Diversity and Omission Errors as Predictors of Language Ability in the Narratives of Sequential Spanish-English Bilinguals: A Cross-Language Comparison

ERIC Educational Resources Information Center

Jacobson, Peggy F.; Walden, Patrick R.

2013-01-01

Purpose: This study explored the utility of language sample analysis for evaluating language ability in school-age Spanish-English sequential bilingual children. Specifically, the relative potential of lexical diversity and word/morpheme omission as predictors of typical or atypical language status was evaluated. Method: Narrative samples were…

Type I and Type II Error Rates and Overall Accuracy of the Revised Parallel Analysis Method for Determining the Number of Factors

ERIC Educational Resources Information Center

Green, Samuel B.; Thompson, Marilyn S.; Levy, Roy; Lo, Wen-Juo

2015-01-01

Traditional parallel analysis (T-PA) estimates the number of factors by sequentially comparing sample eigenvalues with eigenvalues for randomly generated data. Revised parallel analysis (R-PA) sequentially compares the "k"th eigenvalue for sample data to the "k"th eigenvalue for generated data sets, conditioned on"k"-…

40 CFR 53.34 - Test procedure for methods for PM10 and Class I methods for PM2.5.

Code of Federal Regulations, 2010 CFR

2010-07-01

... simultaneous PM10 or PM2.5 measurements as necessary (see table C-4 of this subpart), each set consisting of...) in appendix A to this subpart). (f) Sequential samplers. For sequential samplers, the sampler shall be configured for the maximum number of sequential samples and shall be set for automatic collection...

Sequential Leaching of Chromium Contaminated Sediments - A Study Characterizing Natural Attenuation

NASA Astrophysics Data System (ADS)

Musa, D.; Ding, M.; Beroff, S.; Rearick, M.; Perkins, G.; WoldeGabriel, G. W.; Ware, D.; Harris, R.; Kluk, E.; Katzman, D.; Reimus, P. W.; Heikoop, J. M.

2015-12-01

Natural attenuation is an important process in slowing down the transport of hexavalent chromium, Cr(VI), an anthropogenic environmental contaminant, either by adsorption of Cr(VI) to sediments, or by reduction to nontoxic trivalent chromium, Cr(III). The capacity and mechanism of attenuation is explored in this sequential leaching study of different particle size fractions of chromium contaminated sediments and similar uncontaminated sediments from the regional aquifer near Los Alamos, New Mexico. Using this leaching protocol each sediment sample is split in two: one half is leached three times using a 0.1 M sodium bicarbonate/carbonate solution, while the second half is leached three times using a 0.01 M nitric acid, followed by two consecutively increasing magnitudes of nitric acid concentrations. Based on the amphoteric nature of chromium, alkaline leaching is used to establish the amount of Cr(VI) sorbed on the sediment, whereas acid leaching is used to establish the amount of Cr(III). The weak acid is predicted to release the attenuated anthropogenic Cr(III), without affecting Cr-bearing minerals. The sequential, stronger, acid is anticipated to leach Cr(III)-incorporated in the minerals. The efficiency and validation of the sequential leaching method is assessed by comparing the leaching behavior of bentonite and biotite samples, with and without loaded Cr(VI). A 97% chromium mass balance of leached Cr(VI)-loaded bentonite and biotite proves the viability of this method for further use on leaching contaminated sediments. By comparing contaminated and uncontaminated sediment leachate results, of chromium and other major and trace elements, the signature of anthropogenic chromium is determined. Further mineralogical characterization of the sediments provides a quantitative measure of the natural attenuation capacity for chromium. Understanding these results is pertinent in delineating the optimal procedure for the remediation of Cr(VI) in the regional aquifer near Los Alamos.

Reduction of display artifacts by random sampling

NASA Technical Reports Server (NTRS)

Ahumada, A. J., Jr.; Nagel, D. C.; Watson, A. B.; Yellott, J. I., Jr.

1983-01-01

The application of random-sampling techniques to remove visible artifacts (such as flicker, moire patterns, and paradoxical motion) introduced in TV-type displays by discrete sequential scanning is discussed and demonstrated. Sequential-scanning artifacts are described; the window of visibility defined in spatiotemporal frequency space by Watson and Ahumada (1982 and 1983) and Watson et al. (1983) is explained; the basic principles of random sampling are reviewed and illustrated by the case of the human retina; and it is proposed that the sampling artifacts can be replaced by random noise, which can then be shifted to frequency-space regions outside the window of visibility. Vertical sequential, single-random-sequence, and continuously renewed random-sequence plotting displays generating 128 points at update rates up to 130 Hz are applied to images of stationary and moving lines, and best results are obtained with the single random sequence for the stationary lines and with the renewed random sequence for the moving lines.

Feed additive production by fermentation of herb Polygonum hydropiper L. and cassava pulp with simultaneous flavonoid dissolution.

PubMed

Song, Zhen-Tao; Zhu, Ming-Jun

2017-03-01

Fermentation of herb Polygonum hydropiper L. (PHL) and cassava pulp (CP) for feed additive production with simultaneous flavonoid dissolution was investigated, and a two-stage response surface methodology (RSM) based on Plackett-Burman factorial design (PB design) was used to optimize the flavonoid dissolution and protein content. Using the screening function of PB design, four different significant factors for the two response variables were acquired: factors A (CP) and B (PHL) for the flavonoid dissolution versus factors G (inoculum size) and H (fermentation time) for protein content. Then, two RSMs were used sequentially to improve the values of the two response variables separately. The mutual corroboration of the experimental results in the present study confirmed the validity of the associated experimental design. The validation experiment showed a flavonoid dissolution rate of 94.00%, and a protein content of 18.20%, gaining an increase in 21.20% and 199.10% over the control, respectively. The present study confirms the feasibility of feed additive production by Saccharomyces cerevisiae with CP and PHL and simultaneous optimization of flavonoid dissolution and protein content using a two-stage RSM. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

A Bayesian-frequentist two-stage single-arm phase II clinical trial design.

PubMed

Dong, Gaohong; Shih, Weichung Joe; Moore, Dirk; Quan, Hui; Marcella, Stephen

2012-08-30

It is well-known that both frequentist and Bayesian clinical trial designs have their own advantages and disadvantages. To have better properties inherited from these two types of designs, we developed a Bayesian-frequentist two-stage single-arm phase II clinical trial design. This design allows both early acceptance and rejection of the null hypothesis ( H(0) ). The measures (for example probability of trial early termination, expected sample size, etc.) of the design properties under both frequentist and Bayesian settings are derived. Moreover, under the Bayesian setting, the upper and lower boundaries are determined with predictive probability of trial success outcome. Given a beta prior and a sample size for stage I, based on the marginal distribution of the responses at stage I, we derived Bayesian Type I and Type II error rates. By controlling both frequentist and Bayesian error rates, the Bayesian-frequentist two-stage design has special features compared with other two-stage designs. Copyright © 2012 John Wiley & Sons, Ltd.

Proposed hardware architectures of particle filter for object tracking

NASA Astrophysics Data System (ADS)

Abd El-Halym, Howida A.; Mahmoud, Imbaby Ismail; Habib, SED

2012-12-01

In this article, efficient hardware architectures for particle filter (PF) are presented. We propose three different architectures for Sequential Importance Resampling Filter (SIRF) implementation. The first architecture is a two-step sequential PF machine, where particle sampling, weight, and output calculations are carried out in parallel during the first step followed by sequential resampling in the second step. For the weight computation step, a piecewise linear function is used instead of the classical exponential function. This decreases the complexity of the architecture without degrading the results. The second architecture speeds up the resampling step via a parallel, rather than a serial, architecture. This second architecture targets a balance between hardware resources and the speed of operation. The third architecture implements the SIRF as a distributed PF composed of several processing elements and central unit. All the proposed architectures are captured using VHDL synthesized using Xilinx environment, and verified using the ModelSim simulator. Synthesis results confirmed the resource reduction and speed up advantages of our architectures.

Combined techniques for characterising pasta structure reveals how the gluten network slows enzymic digestion rate.

PubMed

Zou, Wei; Sissons, Mike; Gidley, Michael J; Gilbert, Robert G; Warren, Frederick J

2015-12-01

The aim of the present study is to characterise the influence of gluten structure on the kinetics of starch hydrolysis in pasta. Spaghetti and powdered pasta were prepared from three different cultivars of durum semolina, and starch was also purified from each cultivar. Digestion kinetic parameters were obtained through logarithm-of-slope analysis, allowing identification of sequential digestion steps. Purified starch and semolina were digested following a single first-order rate constant, while pasta and powdered pasta followed two sequential first-order rate constants. Rate coefficients were altered by pepsin hydrolysis. Confocal microscopy revealed that, following cooking, starch granules were completely swollen for starch, semolina and pasta powder samples. In pasta, they were completely swollen in the external regions, partially swollen in the intermediate region and almost intact in the pasta strand centre. Gluten entrapment accounts for sequential kinetic steps in starch digestion of pasta; the compact microstructure of pasta also reduces digestion rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Sequential Optimization Sampling Method for Metamodels with Radial Basis Functions

PubMed Central

Pan, Guang; Ye, Pengcheng; Yang, Zhidong

2014-01-01

Metamodels have been widely used in engineering design to facilitate analysis and optimization of complex systems that involve computationally expensive simulation programs. The accuracy of metamodels is strongly affected by the sampling methods. In this paper, a new sequential optimization sampling method is proposed. Based on the new sampling method, metamodels can be constructed repeatedly through the addition of sampling points, namely, extrema points of metamodels and minimum points of density function. Afterwards, the more accurate metamodels would be constructed by the procedure above. The validity and effectiveness of proposed sampling method are examined by studying typical numerical examples. PMID:25133206

Determination of nitrite and nitrate in water samples by an automated hydrodynamic sequential injection method.

PubMed

Somnam, Sarawut; Jakmunee, Jaroon; Grudpan, Kate; Lenghor, Narong; Motomizu, Shoji

2008-12-01

An automated hydrodynamic sequential injection (HSI) system with spectrophotometric detection was developed. Thanks to the hydrodynamic injection principle, simple devices can be used for introducing reproducible microliter volumes of both sample and reagent into the flow channel to form stacked zones in a similar fashion to those in a sequential injection system. The zones were then pushed to the detector and a peak profile was recorded. The determination of nitrite and nitrate in water samples by employing the Griess reaction was chosen as a model. Calibration graphs with linearity in the range of 0.7 - 40 muM were obtained for both nitrite and nitrate. Detection limits were found to be 0.3 muM NO(2)(-) and 0.4 muM NO(3)(-), respectively, with a sample throughput of 20 h(-1) for consecutive determination of both the species. The developed system was successfully applied to the analysis of water samples, employing simple and cost-effective instrumentation and offering higher degrees of automation and low chemical consumption.

Guided transect sampling - a new design combining prior information and field surveying

Treesearch

Anna Ringvall; Goran Stahl; Tomas Lamas

2000-01-01

Guided transect sampling is a two-stage sampling design in which prior information is used to guide the field survey in the second stage. In the first stage, broad strips are randomly selected and divided into grid-cells. For each cell a covariate value is estimated from remote sensing data, for example. The covariate is the basis for subsampling of a transect through...

Tracking vaginal, anal and oral infection in a mouse papillomavirus infection model.

PubMed

Hu, Jiafen; Budgeon, Lynn R; Cladel, Nancy M; Balogh, Karla; Myers, Roland; Cooper, Timothy K; Christensen, Neil D

2015-12-01

Noninvasive and practical techniques to longitudinally track viral infection are sought after in clinical practice. We report a proof-of-principle study to monitor the viral DNA copy number using a newly established mouse papillomavirus (MmuPV1) mucosal infection model. We hypothesized that viral presence could be identified and quantified by collecting lavage samples from cervicovaginal, anal and oral sites. Nude mice infected at these sites with infectious MmuPV1 were tracked for up to 23 weeks starting at 6 weeks post-infection. Viral DNA copy number was determined by SYBR Green Q-PCR analysis. In addition, we tracked viral DNA load through three complete oestrous cycles to pinpoint whether there was a correlation between the DNA load and the four stages of the oestrous cycle. Our results showed that high viral DNA copy number was reproducibly detected from both anal and cervicovaginal lavage samples. The infection and disease progression were further confirmed by histology, cytology, in situ hybridization, immunohistochemistry and transmission electron microscopy. Interestingly, the viral copy number fluctuated over the oestrous cycle, with the highest level at the oestrus stage, implying that multiple sampling might be necessary to provide a reliable diagnosis. Virus DNA was detected in oral lavage samples at a later time after infection. Lower viral DNA load was found in oral samples when compared with those in anal and vaginal tracts. To our knowledge, our study is the first in vivo study to sequentially monitor papillomavirus infection from mucosal anal, oral and vaginal tracts in a preclinical model.

Fuel mixture stratification as a method for improving homogeneous charge compression ignition engine operation

DOEpatents

Dec, John E [Livermore, CA; Sjoberg, Carl-Magnus G [Livermore, CA

2006-10-31

A method for slowing the heat-release rate in homogeneous charge compression ignition ("HCCI") engines that allows operation without excessive knock at higher engine loads than are possible with conventional HCCI. This method comprises injecting a fuel charge in a manner that creates a stratified fuel charge in the engine cylinder to provide a range of fuel concentrations in the in-cylinder gases (typically with enough oxygen for complete combustion) using a fuel with two-stage ignition fuel having appropriate cool-flame chemistry so that regions of different fuel concentrations autoignite sequentially.

Sequential lineup laps and eyewitness accuracy.

PubMed

Steblay, Nancy K; Dietrich, Hannah L; Ryan, Shannon L; Raczynski, Jeanette L; James, Kali A

2011-08-01

Police practice of double-blind sequential lineups prompts a question about the efficacy of repeated viewings (laps) of the sequential lineup. Two laboratory experiments confirmed the presence of a sequential lap effect: an increase in witness lineup picks from first to second lap, when the culprit was a stranger. The second lap produced more errors than correct identifications. In Experiment 2, lineup diagnosticity was significantly higher for sequential lineup procedures that employed a single versus double laps. Witnesses who elected to view a second lap made significantly more errors than witnesses who chose to stop after one lap or those who were required to view two laps. Witnesses with prior exposure to the culprit did not exhibit a sequential lap effect.

Information extraction during simultaneous motion processing.

PubMed

Rideaux, Reuben; Edwards, Mark

2014-02-01

When confronted with multiple moving objects the visual system can process them in two stages: an initial stage in which a limited number of signals are processed in parallel (i.e. simultaneously) followed by a sequential stage. We previously demonstrated that during the simultaneous stage, observers could discriminate between presentations containing up to 5 vs. 6 spatially localized motion signals (Edwards & Rideaux, 2013). Here we investigate what information is actually extracted during the simultaneous stage and whether the simultaneous limit varies with the detail of information extracted. This was achieved by measuring the ability of observers to extract varied information from low detail, i.e. the number of signals presented, to high detail, i.e. the actual directions present and the direction of a specific element, during the simultaneous stage. The results indicate that the resolution of simultaneous processing varies as a function of the information which is extracted, i.e. as the information extraction becomes more detailed, from the number of moving elements to the direction of a specific element, the capacity to process multiple signals is reduced. Thus, when assigning a capacity to simultaneous motion processing, this must be qualified by designating the degree of information extraction. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Machine learning based detection of age-related macular degeneration (AMD) and diabetic macular edema (DME) from optical coherence tomography (OCT) images

PubMed Central

Wang, Yu; Zhang, Yaonan; Yao, Zhaomin; Zhao, Ruixue; Zhou, Fengfeng

2016-01-01

Non-lethal macular diseases greatly impact patients’ life quality, and will cause vision loss at the late stages. Visual inspection of the optical coherence tomography (OCT) images by the experienced clinicians is the main diagnosis technique. We proposed a computer-aided diagnosis (CAD) model to discriminate age-related macular degeneration (AMD), diabetic macular edema (DME) and healthy macula. The linear configuration pattern (LCP) based features of the OCT images were screened by the Correlation-based Feature Subset (CFS) selection algorithm. And the best model based on the sequential minimal optimization (SMO) algorithm achieved 99.3% in the overall accuracy for the three classes of samples. PMID:28018716

Effectiveness of the Treatment Readiness and Induction Program for Increasing Adolescent Motivation for Change

PubMed Central

Becan, Jennifer E.; Knight, Danica K.; Crawley, Rachel D.; Joe, George W.; Flynn, Patrick M.

2014-01-01

Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (Time 1) and 35 days after admission (Time 2). The design consisted of a comparison sample (n = 281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n = 238). Repeated measures ANCOVAs were conducted using each Time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. PMID:25456094

An NCME Instructional Module on Quality Control Procedures in the Scoring, Equating, and Reporting of Test Scores

ERIC Educational Resources Information Center

Allalouf, Avi

2007-01-01

There is significant potential for error in long production processes that consist of sequential stages, each of which is heavily dependent on the previous stage, such as the SER (Scoring, Equating, and Reporting) process. Quality control procedures are required in order to monitor this process and to reduce the number of mistakes to a minimum. In…

Online sequential Monte Carlo smoother for partially observed diffusion processes

NASA Astrophysics Data System (ADS)

Gloaguen, Pierre; Étienne, Marie-Pierre; Le Corff, Sylvain

2018-12-01

This paper introduces a new algorithm to approximate smoothed additive functionals of partially observed diffusion processes. This method relies on a new sequential Monte Carlo method which allows to compute such approximations online, i.e., as the observations are received, and with a computational complexity growing linearly with the number of Monte Carlo samples. The original algorithm cannot be used in the case of partially observed stochastic differential equations since the transition density of the latent data is usually unknown. We prove that it may be extended to partially observed continuous processes by replacing this unknown quantity by an unbiased estimator obtained for instance using general Poisson estimators. This estimator is proved to be consistent and its performance are illustrated using data from two models.

Using extreme phenotype sampling to identify the rare causal variants of quantitative traits in association studies.

PubMed

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J; Murcray, Cassandra Elizabeth; Conti, David

2011-12-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. © 2011 Wiley Periodicals, Inc.

Using Extreme Phenotype Sampling to Identify the Rare Causal Variants of Quantitative Traits in Association Studies

PubMed Central

Li, Dalin; Lewinger, Juan Pablo; Gauderman, William J.; Murcray, Cassandra Elizabeth; Conti, David

2014-01-01

Variants identified in recent genome-wide association studies based on the common-disease common-variant hypothesis are far from fully explaining the hereditability of complex traits. Rare variants may, in part, explain some of the missing hereditability. Here, we explored the advantage of the extreme phenotype sampling in rare-variant analysis and refined this design framework for future large-scale association studies on quantitative traits. We first proposed a power calculation approach for a likelihood-based analysis method. We then used this approach to demonstrate the potential advantages of extreme phenotype sampling for rare variants. Next, we discussed how this design can influence future sequencing-based association studies from a cost-efficiency (with the phenotyping cost included) perspective. Moreover, we discussed the potential of a two-stage design with the extreme sample as the first stage and the remaining nonextreme subjects as the second stage. We demonstrated that this two-stage design is a cost-efficient alternative to the one-stage cross-sectional design or traditional two-stage design. We then discussed the analysis strategies for this extreme two-stage design and proposed a corresponding design optimization procedure. To address many practical concerns, for example measurement error or phenotypic heterogeneity at the very extremes, we examined an approach in which individuals with very extreme phenotypes are discarded. We demonstrated that even with a substantial proportion of these extreme individuals discarded, an extreme-based sampling can still be more efficient. Finally, we expanded the current analysis and design framework to accommodate the CMC approach where multiple rare-variants in the same gene region are analyzed jointly. PMID:21922541

Correlates of Canadian Native Children's Reading Performance: From Cognitive Styles to Cognitive Processes

ERIC Educational Resources Information Center

Das, J. P.; Janzen, Troy; Georgiou, George K.

2007-01-01

Individual differences in reading and cognitive processing among a sample of generally poor readers were studied in order to answer two major questions: Do they have a specific cognitive style that favors global-simultaneous strategies and a weak sequential strategy? If they do not have a distinct cognitive style or strategy, but are merely poor…

Decision making and sequential sampling from memory

PubMed Central

Shadlen, Michael N.; Shohamy, Daphna

2016-01-01

Decisions take time, and as a rule more difficult decisions take more time. But this only raises the question of what consumes the time. For decisions informed by a sequence of samples of evidence, the answer is straightforward: more samples are available with more time. Indeed the speed and accuracy of such decisions are explained by the accumulation of evidence to a threshold or bound. However, the same framework seems to apply to decisions that are not obviously informed by sequences of evidence samples. Here we proffer the hypothesis that the sequential character of such tasks involves retrieval of evidence from memory. We explore this hypothesis by focusing on value-based decisions and argue that mnemonic processes can account for regularities in choice and decision time. We speculate on the neural mechanisms that link sampling of evidence from memory to circuits that represent the accumulated evidence bearing on a choice. We propose that memory processes may contribute to a wider class of decisions that conform to the regularities of choice-reaction time predicted by the sequential sampling framework. PMID:27253447

Determination of yeast assimilable nitrogen content in wine fermentations by sequential injection analysis with spectrophotometric detetection.

PubMed

Muik, Barbara; Edelmann, Andrea; Lendl, Bernhard; Ayora-Cañada, María José

2002-09-01

An automated method for measuring the primary amino acid concentration in wine fermentations by sequential injection analysis with spectrophotometric detection was developed. Isoindole-derivatives from the primary amino acid were formed by reaction with o-phthaldialdehyde and N-acetyl- L-cysteine and measured at 334 nm with respect to a baseline point at 700 nm to compensate the observed Schlieren effect. As the reaction kinetic was strongly matrix dependent the analytical readout at the final reaction equilibrium has been evaluated. Therefore four parallel reaction coils were included in the flow system to be capable of processing four samples simultaneously. Using isoleucine as the representative primary amino acid in wine fermentations a linear calibration curve from 2 to 10 mM isoleucine, corresponding to 28 to 140 mg nitrogen/L (N/L) was obtained. The coefficient of variation of the method was 1.5% at a throughput of 12 samples per hour. The developed method was successfully used to monitor two wine fermentations during alcoholic fermentation. The results were in agreement with an external reference method based on high performance liquid chromatography. A mean-t-test showed no significant differences between the two methods at a confidence level of 95%.

Adaptive web sampling.

PubMed

Thompson, Steven K

2006-12-01

A flexible class of adaptive sampling designs is introduced for sampling in network and spatial settings. In the designs, selections are made sequentially with a mixture distribution based on an active set that changes as the sampling progresses, using network or spatial relationships as well as sample values. The new designs have certain advantages compared with previously existing adaptive and link-tracing designs, including control over sample sizes and of the proportion of effort allocated to adaptive selections. Efficient inference involves averaging over sample paths consistent with the minimal sufficient statistic. A Markov chain resampling method makes the inference computationally feasible. The designs are evaluated in network and spatial settings using two empirical populations: a hidden human population at high risk for HIV/AIDS and an unevenly distributed bird population.

[Multi-disciplinary treatment increases the survival rate of late stage pharyngeal, laryngeal or cervical esophageal cancers treated by free jejunal flap reconstruction after cancer resection].

PubMed

Zhu, Y M; Zhang, H; Ni, S; Wang, J; Li, D Z; Liu, S Y

2016-05-23

To investigate the survival status of patients with pharyngeal, laryngeal or cervical esophageal cancers, who received free jejunal flap (FJF) to repair the defects following tumor resection, and to analyze the effect of multi-disciplinary treatment on their survival. Fifty-eight patients with pharyngeal, laryngeal or cervical esophageal cancer underwent free jejunal flap (FJF) reconstruction after cancer resection between 2010 and 2013. All their clinical records were reviewed and analyzed. The success rate of flap transplantation was 91.4% (53/58). The 2-year overall survival rates (OSR) of cervical esophageal cancer and hypopharyngeal cancer patients were 67.5% and 49.3%, respectively, both were significantly better than that of laryngeal cancer. The main causes of death were local recurrence and distant metastases. The group with no short-term complications had a better two-year OSR (59.0%) than the group with short-term complications (46.6%), however, the difference between them was not significant (P=0.103). The 2-year survival rate of the initial treatment group was 65.0%, better than that of the salvage treatment group (49.4%), but the difference was not significant (P=0.051). For the stage III and IV patients, the multi-disciplinary treatment group had a significantly better 2-year OSR (64.7%) than the single or sequential treatment group (37.0%, P=0.016). Free jejunal flap reconstruction is an ideal option for repairing the cervical digestive tract circumferential defects caused by tumor resection with a high success rate and a low mortality. Compared with the single or sequential treatment, multi-disciplinary treatment can significantly improve the survival rate of late-stage hypopharyngeal and cervical esophageal cancer patients.

Phase II design with sequential testing of hypotheses within each stage.

PubMed

Poulopoulou, Stavroula; Karlis, Dimitris; Yiannoutsos, Constantin T; Dafni, Urania

2014-01-01

The main goal of a Phase II clinical trial is to decide, whether a particular therapeutic regimen is effective enough to warrant further study. The hypothesis tested by Fleming's Phase II design (Fleming, 1982) is [Formula: see text] versus [Formula: see text], with level [Formula: see text] and with a power [Formula: see text] at [Formula: see text], where [Formula: see text] is chosen to represent the response probability achievable with standard treatment and [Formula: see text] is chosen such that the difference [Formula: see text] represents a targeted improvement with the new treatment. This hypothesis creates a misinterpretation mainly among clinicians that rejection of the null hypothesis is tantamount to accepting the alternative, and vice versa. As mentioned by Storer (1992), this introduces ambiguity in the evaluation of type I and II errors and the choice of the appropriate decision at the end of the study. Instead of testing this hypothesis, an alternative class of designs is proposed in which two hypotheses are tested sequentially. The hypothesis [Formula: see text] versus [Formula: see text] is tested first. If this null hypothesis is rejected, the hypothesis [Formula: see text] versus [Formula: see text] is tested next, in order to examine whether the therapy is effective enough to consider further testing in a Phase III study. For the derivation of the proposed design the exact binomial distribution is used to calculate the decision cut-points. The optimal design parameters are chosen, so as to minimize the average sample number (ASN) under specific upper bounds for error levels. The optimal values for the design were found using a simulated annealing method.

Multi-Attribute Sequential Search

ERIC Educational Resources Information Center

Bearden, J. Neil; Connolly, Terry

2007-01-01

This article describes empirical and theoretical results from two multi-attribute sequential search tasks. In both tasks, the DM sequentially encounters options described by two attributes and must pay to learn the values of the attributes. In the "continuous" version of the task the DM learns the precise numerical value of an attribute when she…

Residents Living in Residential Care Facilities: United States, 2010

MedlinePlus

... NSRCF used a stratified two-stage probability sample design. The first stage was the selection of RCFs ... was 99%. A detailed description of NSRCF sampling design, data collection, and procedures is provided both in ...

Sequential Injection Chromatography with an Ultra-short Monolithic Column for the Low-Pressure Separation of α-Tocopherol and γ-Oryzanol in Vegetable Oils and Nutrition Supplements.

PubMed

Thaithet, Sujitra; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai

2017-01-01

A low-pressure separation procedure of α-tocopherol and γ-oryzanol was developed based on a sequential injection chromatography (SIC) system coupled with an ultra-short (5 mm) C-18 monolithic column, as a lower cost and more compact alternative to the HPLC system. A green sample preparation, dilution with a small amount of hexane followed by liquid-liquid extraction with 80% ethanol, was proposed. Very good separation resolution (R s = 3.26), a satisfactory separation time (10 min) and a total run time including column equilibration (16 min) were achieved. The linear working range was found to be 0.4 - 40 μg with R 2 being more than 0.99. The detection limits of both analytes were 0.28 μg with the repeatability within 5% RSD (n = 7). Quantitative analyses of the two analytes in vegetable oil and nutrition supplement samples, using the proposed SIC method, agree well with the results from HPLC.

Sequential Extraction Results and Mineralogy of Mine Waste and Stream Sediments Associated With Metal Mines in Vermont, Maine, and New Zealand

USGS Publications Warehouse

Piatak, N.M.; Seal, R.R.; Sanzolone, R.F.; Lamothe, P.J.; Brown, Z.A.; Adams, M.

2007-01-01

We report results from sequential extraction experiments and the quantitative mineralogy for samples of stream sediments and mine wastes collected from metal mines. Samples were from the Elizabeth, Ely Copper, and Pike Hill Copper mines in Vermont, the Callahan Mine in Maine, and the Martha Mine in New Zealand. The extraction technique targeted the following operationally defined fractions and solid-phase forms: (1) soluble, adsorbed, and exchangeable fractions; (2) carbonates; (3) organic material; (4) amorphous iron- and aluminum-hydroxides and crystalline manganese-oxides; (5) crystalline iron-oxides; (6) sulfides and selenides; and (7) residual material. For most elements, the sum of an element from all extractions steps correlated well with the original unleached concentration. Also, the quantitative mineralogy of the original material compared to that of the residues from two extraction steps gave insight into the effectiveness of reagents at dissolving targeted phases. The data are presented here with minimal interpretation or discussion and further analyses and interpretation will be presented elsewhere.

Constraint treatment techniques and parallel algorithms for multibody dynamic analysis. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Chiou, Jin-Chern

1990-01-01

Computational procedures for kinematic and dynamic analysis of three-dimensional multibody dynamic (MBD) systems are developed from the differential-algebraic equations (DAE's) viewpoint. Constraint violations during the time integration process are minimized and penalty constraint stabilization techniques and partitioning schemes are developed. The governing equations of motion, a two-stage staggered explicit-implicit numerical algorithm, are treated which takes advantage of a partitioned solution procedure. A robust and parallelizable integration algorithm is developed. This algorithm uses a two-stage staggered central difference algorithm to integrate the translational coordinates and the angular velocities. The angular orientations of bodies in MBD systems are then obtained by using an implicit algorithm via the kinematic relationship between Euler parameters and angular velocities. It is shown that the combination of the present solution procedures yields a computationally more accurate solution. To speed up the computational procedures, parallel implementation of the present constraint treatment techniques, the two-stage staggered explicit-implicit numerical algorithm was efficiently carried out. The DAE's and the constraint treatment techniques were transformed into arrowhead matrices to which Schur complement form was derived. By fully exploiting the sparse matrix structural analysis techniques, a parallel preconditioned conjugate gradient numerical algorithm is used to solve the systems equations written in Schur complement form. A software testbed was designed and implemented in both sequential and parallel computers. This testbed was used to demonstrate the robustness and efficiency of the constraint treatment techniques, the accuracy of the two-stage staggered explicit-implicit numerical algorithm, and the speed up of the Schur-complement-based parallel preconditioned conjugate gradient algorithm on a parallel computer.

Differentially co-expressed interacting protein pairs discriminate samples under distinct stages of HIV type 1 infection.

PubMed

Yoon, Dukyong; Kim, Hyosil; Suh-Kim, Haeyoung; Park, Rae Woong; Lee, KiYoung

2011-01-01

Microarray analyses based on differentially expressed genes (DEGs) have been widely used to distinguish samples across different cellular conditions. However, studies based on DEGs have not been able to clearly determine significant differences between samples of pathophysiologically similar HIV-1 stages, e.g., between acute and chronic progressive (or AIDS) or between uninfected and clinically latent stages. We here suggest a novel approach to allow such discrimination based on stage-specific genetic features of HIV-1 infection. Our approach is based on co-expression changes of genes known to interact. The method can identify a genetic signature for a single sample as contrasted with existing protein-protein-based analyses with correlational designs. Our approach distinguishes each sample using differentially co-expressed interacting protein pairs (DEPs) based on co-expression scores of individual interacting pairs within a sample. The co-expression score has positive value if two genes in a sample are simultaneously up-regulated or down-regulated. And the score has higher absolute value if expression-changing ratios are similar between the two genes. We compared characteristics of DEPs with that of DEGs by evaluating their usefulness in separation of HIV-1 stage. And we identified DEP-based network-modules and their gene-ontology enrichment to find out the HIV-1 stage-specific gene signature. Based on the DEP approach, we observed clear separation among samples from distinct HIV-1 stages using clustering and principal component analyses. Moreover, the discrimination power of DEPs on the samples (70-100% accuracy) was much higher than that of DEGs (35-45%) using several well-known classifiers. DEP-based network analysis also revealed the HIV-1 stage-specific network modules; the main biological processes were related to "translation," "RNA splicing," "mRNA, RNA, and nucleic acid transport," and "DNA metabolism." Through the HIV-1 stage-related modules, changing stage-specific patterns of protein interactions could be observed. DEP-based method discriminated the HIV-1 infection stages clearly, and revealed a HIV-1 stage-specific gene signature. The proposed DEP-based method might complement existing DEG-based approaches in various microarray expression analyses.

Assessing Compliance-Effect Bias in the Two Stage Least Squares Estimator

ERIC Educational Resources Information Center

Reardon, Sean; Unlu, Fatih; Zhu, Pei; Bloom, Howard

2011-01-01

The proposed paper studies the bias in the two-stage least squares, or 2SLS, estimator that is caused by the compliance-effect covariance (hereafter, the compliance-effect bias). It starts by deriving the formula for the bias in an infinite sample (i.e., in the absence of finite sample bias) under different circumstances. Specifically, it…

Collection and Characterization of Samples for Establishment of a Serum Repository for Lyme Disease Diagnostic Test Development and Evaluation

PubMed Central

Molins, Claudia R.; Sexton, Christopher; Young, John W.; Ashton, Laura V.; Pappert, Ryan; Beard, Charles B.

2014-01-01

Serological assays and a two-tiered test algorithm are recommended for laboratory confirmation of Lyme disease. In the United States, the sensitivity of two-tiered testing using commercially available serology-based assays is dependent on the stage of infection and ranges from 30% in the early localized disease stage to near 100% in late-stage disease. Other variables, including subjectivity in reading Western blots, compliance with two-tiered recommendations, use of different first- and second-tier test combinations, and use of different test samples, all contribute to variation in two-tiered test performance. The availability and use of sample sets from well-characterized Lyme disease patients and controls are needed to better assess the performance of existing tests and for development of improved assays. To address this need, the Centers for Disease Control and Prevention and the National Institutes of Health prospectively collected sera from patients at all stages of Lyme disease, as well as healthy donors and patients with look-alike diseases. Patients and healthy controls were recruited using strict inclusion and exclusion criteria. Samples from all included patients were retrospectively characterized by two-tiered testing. The results from two-tiered testing corroborated the need for novel and improved diagnostics, particularly for laboratory diagnosis of earlier stages of infection. Furthermore, the two-tiered results provide a baseline with samples from well-characterized patients that can be used in comparing the sensitivity and specificity of novel diagnostics. Panels of sera and accompanying clinical and laboratory testing results are now available to Lyme disease serological test users and researchers developing novel tests. PMID:25122862

Different molecular signatures in magnetic resonance imaging-staged facioscapulohumeral muscular dystrophy muscles.

PubMed

Tasca, Giorgio; Pescatori, Mario; Monforte, Mauro; Mirabella, Massimiliano; Iannaccone, Elisabetta; Frusciante, Roberto; Cubeddu, Tiziana; Laschena, Francesco; Ottaviani, Pierfrancesco; Ricci, Enzo

2012-01-01

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease. Histopathology, gene expression profiling and real time PCR were performed on biopsies from FSHD muscles with different MRI pattern (T1-weighted normal/T2-STIR normal and T1-weighted normal/T2-STIR hyperintense). Data were compared with those from inflammatory myopathies, dysferlinopathies and normal controls. In order to validate obtained results, two additional FSHD samples with different MRI pattern were analyzed. Myopathic and inflammatory changes characterized T2-STIR hyperintense FSHD muscles, at variance with T2-STIR normal muscles. These two states could be easily distinguished from each other by their transcriptional profile. The comparison between T2-STIR hyperintense FSHD muscles and inflammatory myopathy muscles showed peculiar changes, although many alterations were shared among these conditions. At the single muscle level, different stages of the disease correspond to the two MRI patterns. T2-STIR hyperintense FSHD muscles are more similar to inflammatory myopathies than to T2-STIR normal FSHD muscles or other muscular dystrophies, and share with them upregulation of genes involved in innate and adaptive immunity. Our data suggest that selective inflammation, together with perturbation in biological processes such as neoangiogenesis, lipid metabolism and adipokine production, may contribute to the sequential bursts of muscle degeneration that involve individual muscles in an asynchronous manner in this disease.

A Two-Stage Method to Determine Optimal Product Sampling considering Dynamic Potential Market

PubMed Central

Hu, Zhineng; Lu, Wei; Han, Bing

2015-01-01

This paper develops an optimization model for the diffusion effects of free samples under dynamic changes in potential market based on the characteristics of independent product and presents a two-stage method to figure out the sampling level. The impact analysis of the key factors on the sampling level shows that the increase of the external coefficient or internal coefficient has a negative influence on the sampling level. And the changing rate of the potential market has no significant influence on the sampling level whereas the repeat purchase has a positive one. Using logistic analysis and regression analysis, the global sensitivity analysis gives a whole analysis of the interaction of all parameters, which provides a two-stage method to estimate the impact of the relevant parameters in the case of inaccuracy of the parameters and to be able to construct a 95% confidence interval for the predicted sampling level. Finally, the paper provides the operational steps to improve the accuracy of the parameter estimation and an innovational way to estimate the sampling level. PMID:25821847

Understanding and preventing type 1 diabetes through the unique working model of TrialNet.

PubMed

Battaglia, Manuela; Anderson, Mark S; Buckner, Jane H; Geyer, Susan M; Gottlieb, Peter A; Kay, Thomas W H; Lernmark, Åke; Muller, Sarah; Pugliese, Alberto; Roep, Bart O; Greenbaum, Carla J; Peakman, Mark

2017-11-01

Type 1 diabetes is an autoimmune disease arising from the destruction of pancreatic insulin-producing beta cells. The disease represents a continuum, progressing sequentially at variable rates through identifiable stages prior to the onset of symptoms, through diagnosis and into the critical periods that follow, culminating in a variable depth of beta cell depletion. The ability to identify the very earliest of these presymptomatic stages has provided a setting in which prevention strategies can be trialled, as well as furnishing an unprecedented opportunity to study disease evolution, including intrinsic and extrinsic initiators and drivers. This niche opportunity is occupied by Type 1 Diabetes TrialNet, an international consortium of clinical trial centres that leads the field in intervention and prevention studies, accompanied by deep longitudinal bio-sampling. In this review, we focus on discoveries arising from this unique bioresource, comprising more than 70,000 samples, and outline the processes and science that have led to new biomarkers and mechanistic insights, as well as identifying new challenges and opportunities. We conclude that via integration of clinical trials and mechanistic studies, drawing in clinicians and scientists and developing partnership with industry, TrialNet embodies an enviable and unique working model for understanding a disease that to date has no cure and for designing new therapeutic approaches.

Understanding and preventing type 1 diabetes through the unique working model of TrialNet

PubMed Central

Anderson, Mark S.; Buckner, Jane H.; Geyer, Susan M.; Gottlieb, Peter A.; Kay, Thomas W. H.; Lernmark, Åke; Muller, Sarah; Pugliese, Alberto; Roep, Bart O.; Greenbaum, Carla J.

2018-01-01

Type 1 diabetes is an autoimmune disease arising from the destruction of pancreatic insulin-producing beta cells. The disease represents a continuum, progressing sequentially at variable rates through identifiable stages prior to the onset of symptoms, through diagnosis and into the critical periods that follow, culminating in a variable depth of beta cell depletion. The ability to identify the very earliest of these presymptomatic stages has provided a setting in which prevention strategies can be trialled, as well as furnishing an unprecedented opportunity to study disease evolution, including intrinsic and extrinsic initiators and drivers. This niche opportunity is occupied by Type 1 Diabetes TrialNet, an international consortium of clinical trial centres that leads the field in intervention and prevention studies, accompanied by deep longitudinal bio-sampling. In this review, we focus on discoveries arising from this unique bioresource, comprising more than 70,000 samples, and outline the processes and science that have led to new biomarkers and mechanistic insights, as well as identifying new challenges and opportunities. We conclude that via integration of clinical trials and mechanistic studies, drawing in clinicians and scientists and developing partnership with industry, TrialNet embodies an enviable and unique working model for understanding a disease that to date has no cure and for designing new therapeutic approaches. PMID:28770323

Elemental Redistribution at the Onset of Soil Genesis from Basalt as Measured in a Soil Lysimeter System

NASA Astrophysics Data System (ADS)

Wang, Y.; Umanzor, M.; Alves Meira Neto, A.; Sengupta, A.; Amistadi, M. K.; Root, R.; Troch, P.; Chorover, J.

2017-12-01

Elemental translocation, resulting in enrichment or depletion relative to parent rock, is a consequence of mineral dissolution and precipitation reactions of soil genesis. Accurate measurement of translocation in natural systems is complicated by factors such as parent material heterogeneity and dust deposition. In the present work, a fully controlled and monitored 10° sloping soil lysimeter with known homogeneous initial conditions, was utilized to investigate initial stages of soil genesis from 1 m3 of crushed basalt. Throughout the two-year experiment, periodic irrigation coupled with sensor measurements enabled monitoring of changes in internal moisture states. A total 15-meter water influx resulted in distinct efflux patterns, wetting and drying cycles, as well as high volume water storage. Biological changes, such as algal and grass emergence, were visible on the soil surface, and microbial colonization throughout the profile was measured in a companion study, suggesting that biogeochemical hotspots may have formed. Forensic excavation and sampling of 324 voxels captured the final state heterogeneity of the lysimeter with respect to length and depth. Total elemental concentrations and a five-step sequential extraction (SE) scheme quantified elemental redistributions into operationally-defined pools including exchangeable, poorly-crystalline (hydr)oxides, and crystalline (hydr)oxides. Data were correlated to water flux and storage that was determined from sensor and tracer data over the two years of rock-water interaction; then used to map 2D cross-sections and identify geochemical hotspots. Total and SE Fe concentrations were used to establish a governing mass balance equation, and sub mass balance equations with unique partitioning coefficients of Fe were developed for each SE pool, respectively. The results help to explain elemental (e.g., Fe) lability and redistribution due to physical and geochemical weathering during the initial stages of soil genesis.

Measuring factor IX activity of nonacog beta pegol with commercially available one-stage clotting and chromogenic assay kits: a two-center study.

PubMed

Bowyer, A E; Hillarp, A; Ezban, M; Persson, P; Kitchen, S

2016-07-01

Essentials Validated assays are required to precisely measure factor IX (FIX) activity in FIX products. N9-GP and two other FIX products were assessed in various coagulation assay systems at two sites. Large variations in FIX activity measurements were observed for N9-GP using some assays. One-stage and chromogenic assays accurately measuring FIX activity for N9-GP were identified. Background Measurement of factor IX activity (FIX:C) with activated partial thromboplastin time-based one-stage clotting assays is associated with a large degree of interlaboratory variation in samples containing glycoPEGylated recombinant FIX (rFIX), i.e. nonacog beta pegol (N9-GP). Validation and qualification of specific assays and conditions are necessary for the accurate assessment of FIX:C in samples containing N9-GP. Objectives To assess the accuracy of various one-stage clotting and chromogenic assays for measuring FIX:C in samples containing N9-GP as compared with samples containing rFIX or plasma-derived FIX (pdFIX) across two laboratory sites. Methods FIX:C, in severe hemophilia B plasma spiked with a range of concentrations (from very low, i.e. 0.03 IU mL(-1) , to high, i.e. 0.90 IU mL(-1) ) of N9-GP, rFIX (BeneFIX), and pdFIX (Mononine), was determined at two laboratory sites with 10 commercially available one-stage clotting assays and two chromogenic FIX:C assays. Assays were performed with a plasma calibrator and different analyzers. Results A high degree of variation in FIX:C measurement was observed for one-stage clotting assays for N9-GP as compared with rFIX or pdFIX. Acceptable N9-GP recovery was observed in the low-concentration to high-concentration samples tested with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays. Similar patterns of FIX:C measurement were observed at both laboratory sites, with minor differences probably being attributable to the use of different analyzers. Conclusions These results suggest that, of the reagents tested, FIX:C in N9-GP-containing plasma samples can be most accurately measured with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays. © 2016 International Society on Thrombosis and Haemostasis.

Comparison of secondary ion mass spectrometry and micromilling/continuous flow isotope ratio mass spectrometry techniques used to acquire intra-otolith delta18O values of wild Atlantic salmon (Salmo salar).

PubMed

Hanson, N N; Wurster, C M; Todd, C D

2010-09-15

The chemical signals in the sequential layers of fish otoliths have the potential to provide fisheries biologists with temporal and spatial details of migration which are difficult to obtain without expensive tracking methods. Signal resolution depends, however, on the extraction technique used. We compared the use of mechanical micromilling and continuous flow isotope ratio mass spectrometry (CF-IRMS) methods with secondary ion mass spectrometry (SIMS) to obtain delta(18)O profiles from otoliths of wild Atlantic salmon (Salmo salar) and used these to corroborate the time of freshwater emigration of the juvenile with macroscopic patterns within the otolith. Both techniques showed the transition occurring at the same visible feature on the otolith, allowing future analyses to easily identify the juvenile (freshwater) versus adult (marine) life-stages. However, SIMS showed a rapid and abrupt transition whereas micromilling provided a less distinct signal. The number of samples that could be obtained per unit area sampled using SIMS was 2 to 3 times greater than that when using micromilling/CF-IRMS although the delta(18)O values and analytical precisions (approximately 0.2 per thousand) of the two methods were comparable. In addition, SIMS delta(18)O results were used to compare otolith aragonite values with predicted values calculated using various isotope fractionation equations. Copyright 2010 John Wiley & Sons, Ltd.

Prevalence and genotyping ofToxoplasma gondii among Saudi pregnant women in Saudi Arabia.

PubMed

Alghamdi, Jawahir; Elamin, Maha Hussein; Alhabib, Samia

2016-11-01

Introduction: Toxoplasma gondii ( T. gondii ) is an intracellular protozoan that can infect all mammals, who serve as intermediate host. It causes congenital, neurological, eyes complications and mild or asymptomatic infections in humans. Purpose of this study: To investigate not only the prevalence of T. gondii , but also to find out its genotyping using multiple sequential molecular methods to predict exactly the precise genotyping of T. gondii among Saudi pregnant women. Methods: A cross-sectional study was conducted using multi-stage methods. Initial stage involved enrolment of 250 Saudi pregnant women from multi-centre healthcare and community based settings in the capital of Saudi Arabia Riyadh. The second stage was embracement of the laboratory investigation that included Enzyme immunoassay (ELISA), DNA extraction, PCR, nested-PCR assay, and genotyping of the seropositive cases. Results: 203 women agreed to take part in our study with a response rate of 81.2% (203/250). Using ELISA, we found that the prevalence of Toxoplasma gondii IgG and IgM antibodies was 32.5% and 6.4%, respectively. We found that 29 samples (80.6%) were of genotype II; however 7 samples (19.4%) were of genotype III. Conclusion: Defining the population structure of T. gondii from Saudi Arabia has important implications for transmission, immunogenicity, pathogenesis, and in planning preventive strategies. Relationship between such variation in structure and disease manifestation in pregnant women is still difficult to assess due to the role of host immune status and genetic background on the control of infection, and of other parasitic features such as the infecting dose or parasite stage. Our finding of the genotyping of T. gondii might facilitate and inform future studies on comparative genomics and identification of genes that control important biological phenotypes including pathogenesis and transmission among Saudi women.

Coupling of acrylic dyeing wastewater treatment by heterogeneous Fenton oxidation in a continuous stirred tank reactor with biological degradation in a sequential batch reactor.

PubMed

Esteves, Bruno M; Rodrigues, Carmen S D; Boaventura, Rui A R; Maldonado-Hódar, F J; Madeira, Luís M

2016-01-15

This work deals with the treatment of a recalcitrant effluent, from the dyeing stage of acrylic fibres, by combination of the heterogeneous Fenton's process in a continuous stirred tank reactor (CSTR) with biological degradation in a sequential batch reactor (SBR). Three different catalysts (a commercial Fe/ZSM-5 zeolite and two distinct Fe-containing activated carbons - ACs - prepared by wet impregnation of iron acetate and iron nitrate) were employed on the Fenton's process, and afterwards a parametric study was carried out to determine the effect of the main operating conditions, namely the hydrogen peroxide feed concentration, temperature and contact time. Under the best operating conditions found, using the activated carbon impregnated with iron nitrate, 62.7% of discolouration and 39.9% of total organic carbon (TOC) reduction were achieved, at steady-state. Furthermore, a considerable increase in the effluent's biodegradability was attained (BOD5:COD ratio increased from <0.001 to 0.27 and SOUR - specific oxygen uptake rate - from <0.2 to 11.1 mg O2/(gVSS·h)), alongside a major decrease in its toxicity (from 92.1 to 94.0% of Vibrio fischeri inhibition down to 6.9-9.9%). This allowed the application of the subsequent biological degradation stage. The combination of the two processes provided a treated effluent that clearly complies with the legislated discharge limits. It was also found that the iron leaching from the three catalysts tested was very small in all runs, a crucial factor for the stability and long-term use of such materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

A mixed-methods research approach to the review of competency standards for orthotist/prosthetists in Australia.

PubMed

Ash, Susan; O'Connor, Jackie; Anderson, Sarah; Ridgewell, Emily; Clarke, Leigh

2015-06-01

The requirement for an allied health workforce is expanding as the global burden of disease increases internationally. To safely meet the demand for an expanded workforce of orthotist/prosthetists in Australia, competency based standards, which are up-to-date and evidence-based, are required. The aims of this study were to determine the minimum level for entry into the orthotic/prosthetic profession; to develop entry level competency standards for the profession; and to validate the developed entry-level competency standards within the profession nationally, using an evidence-based approach. A mixed-methods research design was applied, using a three-step sequential exploratory design, where step 1 involved collecting and analyzing qualitative data from two focus groups; step 2 involved exploratory instrument development and testing, developing the draft competency standards; and step 3 involved quantitative data collection and analysis - a Delphi survey. In stage 1 (steps 1 and 2), the two focus groups - an expert and a recent graduate group of Australian orthotist/prosthetists - were led by an experienced facilitator, to identify gaps in the current competency standards and then to outline a key purpose, and work roles and tasks for the profession. The resulting domains and activities of the first draft of the competency standards were synthesized using thematic analysis. In stage 2 (step 3), the draft-competency standards were circulated to a purposive sample of the membership of the Australian Orthotic Prosthetic Association, using three rounds of Delphi survey. A project reference group of orthotist/prosthetists reviewed the results of both stages. In stage 1, the expert (n = 10) and the new graduate (n = 8) groups separately identified work roles and tasks, which formed the initial draft of the competency standards. Further drafts were refined and performance criteria added by the project reference group, resulting in the final draft-competency standards. In stage 2, the final draft-competency standards were circulated to 56 members (n = 44 final round) of the Association, who agreed on the key purpose, 6 domains, 18 activities, and 68 performance criteria of the final competency standards. This study outlines a rigorous and evidence-based mixed-methods approach for developing and endorsing professional competency standards, which is representative of the views of the profession of orthotist/prosthetists.

Sequential changes in biliary lipids and gallbladder ion transport during gallstone formation.

PubMed Central

Giurgiu, D I; Saunders-Kirkwood, K D; Roslyn, J J; Abedin, M Z

1997-01-01

OBJECTIVE: This study sought to correlate gallbladder (GB) Na+ and Cl-) fluxes with biliary lipid composition during the various stages of gallstone (GS) formation. SUMMARY BACKGROUND DATA: GS formation is associated with altered GB ion transport and increased biliary lipid and Ca2+ concentrations. Nonetheless, the longitudinal relationship between ion transport and biliary lipid changes during GS formation has not been defined. METHODS: Prairie dogs were fed standard (n = 18) or 1.2% cholesterol-enriched (n = 30) diets for 4 to 21 days. Hepatic and GB bile were analyzed for lipids and Ca2+. Animals were designated either Pre-Crystal, Crystal, or GS based on absence or presence of crystals or GS, respectively. GBs were mounted in Ussing chambers, electrophysiologic parameters were recorded, and unidirectional Na+ and Cl- fluxes measured. RESULTS: Short-circuit current and potential difference were similar during Pre-Crystal and Crystal stages but significantly reduced during GS stage compared to controls and Pre-Crystals. Transepithelial resistance was similar in all groups. Net Na+ absorption was increased during Pre-Crystal but decreased during GS stage due to increased mucosa-to-serosa and serosa-to-mucosa flux, respectively. Increased serosa-to-mucosa flux of both Na+ and Cl- characterized the Crystal stage. Biliary lipids and Ca2+ increased progressively during various stages of GS formation and correlated positively with unidirectional fluxes of Na+ and Cl-. CONCLUSION: GB epithelial ion transport changes sequentially during GS formation, with the early Pre-Crystal stage characterized by increased Na+ absorption, and the later Crystal stage accompanied by prosecretory stimuli on Na+ and Cl- fluxes, which may be due to elevated GB bile Ca2+ and total bile acids. Images Figure 1. Figure 3. Figure 4. PMID:9114797

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.

Uncoupled hydrogen and volatile fatty acids generation in a two-step biotechnological anaerobic process fed with actual site wastewater.

PubMed

Monti, Matilde; Scoma, Alberto; Martinez, Gonzalo; Bertin, Lorenzo; Fava, Fabio

2015-05-25

Among agro-wastes, olive mill wastewater (OMW) truly qualifies as a high impact organic residue due to its biochemical-rich composition and high annual production. In the present investigation, dephenolized OMW (OMWdeph) was employed as the feedstock for a biotechnological two-stage anaerobic process dedicated to the production of biohydrogen and volatile fatty acids (VFAs), respectively. To this end, two identically configured packed-bed biofilm reactors were operated sequentially. In the first, the hydraulic retention time was set to 1 day, whereas in the second it was equal to 5 days. The rationale was to decouple the hydrolysis of the organic macronutrients held by the OMWdeph, so as to quantitatively generate a biogas enriched in H2 (first stage aim), for the acidogenesis of the residual components left after hydrolysis, to then produce a highly concentrated mixture of VFAs (second stage aim). Results showed that the generation of H2 and VFAs was effectively split, with carbohydrates and lipids, respectively, being the main substrates of the two processes. About 250 ml H2 L(-1) day(-1) was produced, corresponding to a yield of 0.36 mol mol(-1) of consumed carbohydrates (expressed as glucose equivalents). The overall concentration of VFAs in the acidogenic process was 13.80 g COD L(-1), so that 2.76 g COD L(-1) day(-1) was obtained. Second generation biorefineries use a selected fraction of an organic waste to conduct a microbiologically-driven pathway towards the generation of one target molecule. With the proposed approach, a greater value of the waste was attained, since the multi-purpose two-stage process did not entail competition for substrates between the first and the second steps. Copyright © 2014 Elsevier B.V. All rights reserved.

Plane-Based Sampling for Ray Casting Algorithm in Sequential Medical Images

PubMed Central

Lin, Lili; Chen, Shengyong; Shao, Yan; Gu, Zichun

2013-01-01

This paper proposes a plane-based sampling method to improve the traditional Ray Casting Algorithm (RCA) for the fast reconstruction of a three-dimensional biomedical model from sequential images. In the novel method, the optical properties of all sampling points depend on the intersection points when a ray travels through an equidistant parallel plan cluster of the volume dataset. The results show that the method improves the rendering speed at over three times compared with the conventional algorithm and the image quality is well guaranteed. PMID:23424608

Transition play in team performance of volleyball: a log-linear analysis.

PubMed

Eom, H J; Schutz, R W

1992-09-01

The purpose of this study was to develop and test a method to analyze and evaluate sequential skill performances in a team sport. An on-line computerized system was developed to record and summarize the sequential skill performances in volleyball. Seventy-two sample games from the third Federation of International Volleyball Cup men's competition were videotaped and grouped into two categories according to the final team standing and game outcome. Log-linear procedures were used to investigate the nature and degree of the relationship in the first-order (pass-to-set, set-to-spike) and second-order (pass-to-spike) transition plays. Results showed that there was a significant dependency in both the first-order and second-order transition plays, indicating that the outcome of a skill performance is highly influenced by the quality of a preceding skill performance. In addition, the pattern of the transition plays was stable and consistent, regardless of the classification status: Game Outcome, Team Standing, or Transition Process. The methodology and subsequent results provide valuable aids for a thorough understanding of the characteristics of transition plays in volleyball. In addition, the concept of sequential performance analysis may serve as an example for sport scientists in investigating probabilistic patterns of motor performance.

Adaptive decision making in a dynamic environment: a test of a sequential sampling model of relative judgment.

PubMed

Vuckovic, Anita; Kwantes, Peter J; Neal, Andrew

2013-09-01

Research has identified a wide range of factors that influence performance in relative judgment tasks. However, the findings from this research have been inconsistent. Studies have varied with respect to the identification of causal variables and the perceptual and decision-making mechanisms underlying performance. Drawing on the ecological rationality approach, we present a theory of the judgment and decision-making processes involved in a relative judgment task that explains how people judge a stimulus and adapt their decision process to accommodate their own uncertainty associated with those judgments. Undergraduate participants performed a simulated air traffic control conflict detection task. Across two experiments, we systematically manipulated variables known to affect performance. In the first experiment, we manipulated the relative distances of aircraft to a common destination while holding aircraft speeds constant. In a follow-up experiment, we introduced a direct manipulation of relative speed. We then fit a sequential sampling model to the data, and used the best fitting parameters to infer the decision-making processes responsible for performance. Findings were consistent with the theory that people adapt to their own uncertainty by adjusting their criterion and the amount of time they take to collect evidence in order to make a more accurate decision. From a practical perspective, the paper demonstrates that one can use a sequential sampling model to understand performance in a dynamic environment, allowing one to make sense of and interpret complex patterns of empirical findings that would otherwise be difficult to interpret using standard statistical analyses. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Language experience differentiates prefrontal and subcortical activation of the cognitive control network in novel word learning

PubMed Central

King, Kelly E.; Hernandez, Arturo E.

2012-01-01

The purpose of this study was to examine the cognitive control mechanisms in adult English speaking monolinguals compared to early sequential Spanish-English bilinguals during the initial stages of novel word learning. Functional magnetic resonance imaging during a lexico-semantic task after only two hours of exposure to novel German vocabulary flashcards showed that monolinguals activated a broader set of cortical control regions associated with higher-level cognitive processes, including the supplementary motor area (SMA), anterior cingulate (ACC), and dorsolateral prefrontal cortex (DLPFC), as well as the caudate, implicated in cognitive control of language. However, bilinguals recruited a more localized subcortical network that included the putamen, associated more with motor control of language. These results suggest that experience managing multiple languages may differentiate the learning strategy and subsequent neural mechanisms of cognitive control used by bilinguals compared to monolinguals in the early stages of novel word learning. PMID:23194816

Divergent pathways to influence: Cognition and behavior differentially mediate the effects of optimism on physical and mental quality of life in Chinese university students.

PubMed

Ramsay, Jonathan E; Yang, Fang; Pang, Joyce S; Lai, Ching-Man; Ho, Roger Cm; Mak, Kwok-Kei

2015-07-01

Previous research has indicated that both cognitive and behavioral variables mediate the positive effect of optimism on quality of life; yet few attempts have been made to accommodate these constructs into a single explanatory framework. Adopting Fredrickson's broaden-and-build perspective, we examined the relationships between optimism, self-rated health, resilience, exercise, and quality of life in 365 Chinese university students using path analysis. For physical quality of life, a two-stage model, in which the effects of optimism were sequentially mediated by cognitive and behavioral variables, provided the best fit. A one-stage model, with full mediation by cognitive variables, provided the best fit for mental quality of life. This suggests that optimism influences physical and mental quality of life via different pathways. © The Author(s) 2013.

Binding intensity and metal partitioning in soils affected by mining and smelting activities in Minas Gerais, Brazil.

PubMed

Lopes, G; Costa, E T S; Penido, E S; Sparks, D L; Guilherme, L R G

2015-09-01

Mining and smelting activities are potential sources of heavy metal contamination, which pose a threat to human health and ecological systems. This study investigated single and sequential extractions of Zn, Pb, and Cd in Brazilian soils affected by mining and smelting activities. Soils from a Zn mining area (soils A, B, C, D, E, and the control soil) and a tailing from a smelting area were collected in Minas Gerais state, Brazil. The samples were subjected to single (using Mehlich I solution) and sequential extractions. The risk assessment code (RAC), the redistribution index (U ts ), and the reduced partition index (I R ) have been applied to the sequential extraction data. Zinc and Cd, in soil samples from the mining area, were found mainly associated with carbonate forms. This same pattern did not occur for Pb. Moreover, the Fe-Mn oxides and residual fractions had important contributions for Zn and Pb in those soils. For the tailing, more than 70 % of Zn and Cd were released in the exchangeable fraction, showing a much higher mobility and availability of these metals at this site, which was also supported by results of RAC and I R . These differences in terms of mobility might be due to different chemical forms of the metals in the two sites, which are attributable to natural occurrence as well as ore processing.

The efficacy of two electrodes radiofrequency technique: comparison study using a cadaveric interspinous ligament and temperature measurement using egg white.

PubMed

Lee, Chang-Hyung; Derby, Richard; Choi, Hyun-Seok; Lee, Sang-Heon; Kim, Se Hoon; Kang, Yoon Kyu

2010-01-01

One technique in radiofrequency neurotomies uses 2 electrodes that are simultaneously placed to lie parallel to one another. Comparing lesions on cadaveric interspinous ligament tissue and measuring the temperature change in egg white allows us to accurately measure quantitatively the area of the lesion. Fresh cadaver spinal tissue and egg white tissue were used. A series of samples were prepared with the electrodes placed 1 to 7 mm apart. Using radiofrequency, the needle electrodes were heated in sequential or simultaneous order and the distance of the escaped lesion area and temperature were measured. Samples of cadaver interspinous ligament showed sequential heating of the needles limits the placement of the needle electrodes up to 2 mm apart from each other and up to 4 mm apart when heated simultaneously. The temperature at the escaped lesion area decreased according to the distance for egg white. There was a significant difference in temperature at the escaped lesion area up to 6 mm apart and the temperature was above 50 degrees celsius up to 5 mm in simultaneous lesion and 3 mm in the sequential lesion. The limitations of this study include cadaveric experimentation and use of intraspinous ligament rather than medial branch of the dorsal ramus which is difficult to identify. Heating the 2 electrodes simultaneously appears to coagulate a wider area and potentially produce better results in less time.

A two-stage cluster sampling method using gridded population data, a GIS, and Google Earth(TM) imagery in a population-based mortality survey in Iraq.

PubMed

Galway, Lp; Bell, Nathaniel; Sae, Al Shatari; Hagopian, Amy; Burnham, Gilbert; Flaxman, Abraham; Weiss, Wiliam M; Rajaratnam, Julie; Takaro, Tim K

2012-04-27

Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

PubMed Central

2012-01-01

Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings. PMID:22540266

Longitudinal study of relative growth rates of the maxilla and the mandible according to quantitative cervical vertebral maturation.

PubMed

Chen, Lili; Liu, Jiarong; Xu, Tianmin; Lin, Jiuxiang

2010-06-01

The purpose of this study was to investigate the relative growth rates (RGR) of the maxilla and the mandible according to quantitative cervical vertebral maturation (QCVM) of adolescents with normal occlusion. Mixed longitudinal data were used. The sample included 87 adolescents (32 boys, 55 girls) from 8 to 18 years of age with normal occlusion, selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year for 6 consecutive years. The growth magnitude (GM) and RGR of the maxilla and the mandible were measured and analyzed. GM and RGR were not always consistent, because subjects had different periods of time between the QCVM stages. GM was not as reliable as RGR. RGR had no significant sex differences in the maxilla and the mandible, in spite of different decelerating curves. However, statistically significant sex differences were found in the GM of mandibular measurements. The greatest growth potentials were not synchronized between the maxilla and the mandible. For both sexes, the greatest RGR of maxillary length and height was in QCVM stage I; then, deceleration occurred. The greatest RGR of mandibular length and height was in QCVM stage II, and the next largest was in QCVM stage I. Understanding the RGR can provide references for orthodontic treatment and orthognathic surgery. 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Economic Factors in Tunnel Construction

DOT National Transportation Integrated Search

1979-02-01

This report describes a new cost estimating system for tunneling. The system is designed so that it may be used to aid planners, engineers, and designers in evaluating the cost impact of decisions they may make during the sequential stages of plannin...

Features of computerized clinical decision support systems supportive of nursing practice: a literature review.

PubMed

Lee, Seonah

2013-10-01

This study aimed to organize the system features of decision support technologies targeted at nursing practice into assessment, problem identification, care plans, implementation, and outcome evaluation. It also aimed to identify the range of the five stage-related sequential decision supports that computerized clinical decision support systems provided. MEDLINE, CINAHL, and EMBASE were searched. A total of 27 studies were reviewed. The system features collected represented the characteristics of each category from patient assessment to outcome evaluation. Several features were common across the reviewed systems. For the sequential decision support, all of the reviewed systems provided decision support in sequence for patient assessment and care plans. Fewer than half of the systems included problem identification. There were only three systems operating in an implementation stage and four systems in outcome evaluation. Consequently, the key steps for sequential decision support functions were initial patient assessment, problem identification, care plan, and outcome evaluation. Providing decision support in such a full scope will effectively help nurses' clinical decision making. By organizing the system features, a comprehensive picture of nursing practice-oriented computerized decision support systems was obtained; however, the development of a guideline for better systems should go beyond the scope of a literature review.

Sequential Designs Based on Bayesian Uncertainty Quantification in Sparse Representation Surrogate Modeling

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

Chen, Ray -Bing; Wang, Weichung; Jeff Wu, C. F.

A numerical method, called OBSM, was recently proposed which employs overcomplete basis functions to achieve sparse representations. While the method can handle non-stationary response without the need of inverting large covariance matrices, it lacks the capability to quantify uncertainty in predictions. We address this issue by proposing a Bayesian approach which first imposes a normal prior on the large space of linear coefficients, then applies the MCMC algorithm to generate posterior samples for predictions. From these samples, Bayesian credible intervals can then be obtained to assess prediction uncertainty. A key application for the proposed method is the efficient construction ofmore » sequential designs. Several sequential design procedures with different infill criteria are proposed based on the generated posterior samples. As a result, numerical studies show that the proposed schemes are capable of solving problems of positive point identification, optimization, and surrogate fitting.« less

Sequential Designs Based on Bayesian Uncertainty Quantification in Sparse Representation Surrogate Modeling

DOE PAGES

Chen, Ray -Bing; Wang, Weichung; Jeff Wu, C. F.

2017-04-12

A numerical method, called OBSM, was recently proposed which employs overcomplete basis functions to achieve sparse representations. While the method can handle non-stationary response without the need of inverting large covariance matrices, it lacks the capability to quantify uncertainty in predictions. We address this issue by proposing a Bayesian approach which first imposes a normal prior on the large space of linear coefficients, then applies the MCMC algorithm to generate posterior samples for predictions. From these samples, Bayesian credible intervals can then be obtained to assess prediction uncertainty. A key application for the proposed method is the efficient construction ofmore » sequential designs. Several sequential design procedures with different infill criteria are proposed based on the generated posterior samples. As a result, numerical studies show that the proposed schemes are capable of solving problems of positive point identification, optimization, and surrogate fitting.« less

Sequential (step-by-step) detection, identification and quantitation of extra virgin olive oil adulteration by chemometric treatment of chromatographic profiles.

PubMed

Capote, F Priego; Jiménez, J Ruiz; de Castro, M D Luque

2007-08-01

An analytical method for the sequential detection, identification and quantitation of extra virgin olive oil adulteration with four edible vegetable oils--sunflower, corn, peanut and coconut oils--is proposed. The only data required for this method are the results obtained from an analysis of the lipid fraction by gas chromatography-mass spectrometry. A total number of 566 samples (pure oils and samples of adulterated olive oil) were used to develop the chemometric models, which were designed to accomplish, step-by-step, the three aims of the method: to detect whether an olive oil sample is adulterated, to identify the type of adulterant used in the fraud, and to determine how much aldulterant is in the sample. Qualitative analysis was carried out via two chemometric approaches--soft independent modelling of class analogy (SIMCA) and K nearest neighbours (KNN)--both approaches exhibited prediction abilities that were always higher than 91% for adulterant detection and 88% for type of adulterant identification. Quantitative analysis was based on partial least squares regression (PLSR), which yielded R2 values of >0.90 for calibration and validation sets and thus made it possible to determine adulteration with excellent precision according to the Shenk criteria.

Estimation of infection prevalence and sensitivity in a stratified two-stage sampling design employing highly specific diagnostic tests when there is no gold standard.

PubMed

Miller, Ezer; Huppert, Amit; Novikov, Ilya; Warburg, Alon; Hailu, Asrat; Abbasi, Ibrahim; Freedman, Laurence S

2015-11-10

In this work, we describe a two-stage sampling design to estimate the infection prevalence in a population. In the first stage, an imperfect diagnostic test was performed on a random sample of the population. In the second stage, a different imperfect test was performed in a stratified random sample of the first sample. To estimate infection prevalence, we assumed conditional independence between the diagnostic tests and develop method of moments estimators based on expectations of the proportions of people with positive and negative results on both tests that are functions of the tests' sensitivity, specificity, and the infection prevalence. A closed-form solution of the estimating equations was obtained assuming a specificity of 100% for both tests. We applied our method to estimate the infection prevalence of visceral leishmaniasis according to two quantitative polymerase chain reaction tests performed on blood samples taken from 4756 patients in northern Ethiopia. The sensitivities of the tests were also estimated, as well as the standard errors of all estimates, using a parametric bootstrap. We also examined the impact of departures from our assumptions of 100% specificity and conditional independence on the estimated prevalence. Copyright © 2015 John Wiley & Sons, Ltd.

Optimal flexible sample size design with robust power.

PubMed

Zhang, Lanju; Cui, Lu; Yang, Bo

2016-08-30

It is well recognized that sample size determination is challenging because of the uncertainty on the treatment effect size. Several remedies are available in the literature. Group sequential designs start with a sample size based on a conservative (smaller) effect size and allow early stop at interim looks. Sample size re-estimation designs start with a sample size based on an optimistic (larger) effect size and allow sample size increase if the observed effect size is smaller than planned. Different opinions favoring one type over the other exist. We propose an optimal approach using an appropriate optimality criterion to select the best design among all the candidate designs. Our results show that (1) for the same type of designs, for example, group sequential designs, there is room for significant improvement through our optimization approach; (2) optimal promising zone designs appear to have no advantages over optimal group sequential designs; and (3) optimal designs with sample size re-estimation deliver the best adaptive performance. We conclude that to deal with the challenge of sample size determination due to effect size uncertainty, an optimal approach can help to select the best design that provides most robust power across the effect size range of interest. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Computerized Hammer Sounding Interpretation for Concrete Assessment with Online Machine Learning.

PubMed

Ye, Jiaxing; Kobayashi, Takumi; Iwata, Masaya; Tsuda, Hiroshi; Murakawa, Masahiro

2018-03-09

Developing efficient Artificial Intelligence (AI)-enabled systems to substitute the human role in non-destructive testing is an emerging topic of considerable interest. In this study, we propose a novel hammering response analysis system using online machine learning, which aims at achieving near-human performance in assessment of concrete structures. Current computerized hammer sounding systems commonly employ lab-scale data to validate the models. In practice, however, the response signal patterns can be far more complicated due to varying geometric shapes and materials of structures. To deal with a large variety of unseen data, we propose a sequential treatment for response characterization. More specifically, the proposed system can adaptively update itself to approach human performance in hammering sounding data interpretation. To this end, a two-stage framework has been introduced, including feature extraction and the model updating scheme. Various state-of-the-art online learning algorithms have been reviewed and evaluated for the task. To conduct experimental validation, we collected 10,940 response instances from multiple inspection sites; each sample was annotated by human experts with healthy/defective condition labels. The results demonstrated that the proposed scheme achieved favorable assessment accuracy with high efficiency and low computation load.

Biochemical and genetic diagnosis of the primary hyperoxalurias: a review.

PubMed

Rumsby, G

2000-01-01

The primary hyperoxalurias are a group of inherited disorders of endogenous oxalate overproduction. Diagnosis of the two best-characterized disorders, primary hyperoxaluria (PH) Types 1 and 2, is achieved by sequential measurement of alanine:glyoxylate aminotransferase and glyoxylate reductase enzyme activity in a single needle liver biopsy. While genetic analysis of PH2 is still at a relatively early stage, the AGXT gene defective in the Type 1 disorder is well characterized, and a number of mutations have been identified. To determine whether mutation analysis could replace enzymatic analysis for the diagnosis of PH1, DNA samples from 127 consecutive unrelated patients in whom there was a high clinical suspicion of primary hyperoxaluria were analyzed for the presence of the G630A and T853C mutations, which together account for approximately 34% of the mutant alleles in our patient cohort. The sensitivity of mutation detection was 47% in those patients with enzymologically confirmed Type 1 disease, showing that mutation analysis cannot effectively replace enzymology at the present time. However, there is little doubt of the value of genetic methods (mutation and linkage analysis) for diagnosing PH1 (and eventually PH2) in other family members and for prenatal diagnosis and carrier testing.

Characteristics of HIV target CD4 T cells collected using different sampling methods from the genital tract of HIV seronegative women.

PubMed

Iyer, Smita S; Sabula, Michael J; Mehta, C Christina; Haddad, Lisa B; Brown, Nakita L; Amara, Rama R; Ofotokun, Igho; Sheth, Anandi N

2017-01-01

Understanding the immune profile of CD4 T cells, the primary targets for HIV, in the female genital tract (FGT) is critical for evaluating and developing effective biomedical HIV prevention strategies in women. However, longitudinal investigation of HIV susceptibility markers expressed by FGT CD4 T cells has been hindered by low cellular yield and risk of sampling-associated trauma. We investigated three minimally invasive FGT sampling methods to characterize and compare CD4 T cell yield and phenotype with the goal of establishing feasible sampling strategies for immune profiling of mucosal CD4 T cells. FGT samples were collected bimonthly from 12 healthy HIV negative women of reproductive age in the following order: 1) Cervicovaginal lavage (CVL), 2) two sequential endocervical flocked swabs (FS), and 3) two sequential endocervical cytobrushes (CB1, CB2). Cells were isolated and phentoyped via flow cytometry. CD4 T cell recovery was highest from each individual CB compared to either CVL or FS (p < 0.0001). The majority of CD4 T cells within the FGT, regardless of sampling method, expressed CCR5 relative to peripheral blood (p < 0.01). Within the CB, CCR5+ CD4 T cells expressed significantly higher levels of α4β7, CD69, and low levels of CD27 relative to CCR5- CD4 T cells (all p < 0.001). We also identified CD4 Treg lineage cells expressing CCR5 among CB samples. Using three different mucosal sampling methods collected longitudinally we demonstrate that CD4 T cells within the FGT express CCR5 and α4β7 and are highly activated, attributes which could act in concert to facilitate HIV acquisition. FS and CB sampling methods can allow for investigation of strategies to reduce HIV target cells in the FGT and could inform the design and interpretation microbicide and vaccine studies in women.

How Does Mentoring Contribute to Gen Y Employees’ Intention to Stay? An Indian Perspective

PubMed Central

Naim, Mohammad Faraz; Lenka, Usha

2017-01-01

The present study is aimed at investigating the impact of mentoring on intention to stay of Gen Y employees working in Indian IT industry. Also, the mediating roles of perceived organization support and affective commitment are examined. Primary data were collected from a sample of 314 Gen Y employees (born between 1980-2000) from IT industry in Delhi, NCR India. Data analysis was carried out using AMOS and SPSS to test sequential mediation. Findings reveal that mentoring has a direct influence on intention to stay of Gen Y employees and perceived organization support and affective commitment sequentially mediate the relationship between the two. This study contributes to the literature on mentoring, perceived organization support, affective commitment, and intention to stay. PMID:28580029

Pathways for learning two languages: lexical and grammatical associations within and across languages in sequential bilingual children*

PubMed Central

PHAM, GIANG

2018-01-01

This study examines the strength and direction of lexical-grammatical associations within and between first and second languages (L1 and L2) in a longitudinal sample of sequential bilinguals. Thirty-three children who spoke Vietnamese (L1) and English (L2) completed picture-naming and story-telling tasks in each language at four yearly intervals. Hierarchical linear modeling across Years 1–4 revealed bidirectional within-language associations and a unidirectional cross-language association from the L1 to L2. Results suggest a conditional relationship between languages in which the L1 supports L2 growth, but not vice versa. Findings contribute to defining pathways for L1 and L2 learning across domains and languages. PMID:29670455

Predictor-corrector framework for the sequential assembly of optical systems based on wavefront sensing.

PubMed

Schindlbeck, Christopher; Pape, Christian; Reithmeier, Eduard

2018-04-16

Alignment of optical components is crucial for the assembly of optical systems to ensure their full functionality. In this paper we present a novel predictor-corrector framework for the sequential assembly of serial optical systems. Therein, we use a hybrid optical simulation model that comprises virtual and identified component positions. The hybrid model is constantly adapted throughout the assembly process with the help of nonlinear identification techniques and wavefront measurements. This enables prediction of the future wavefront at the detector plane and therefore allows for taking corrective measures accordingly during the assembly process if a user-defined tolerance on the wavefront error is violated. We present a novel notation for the so-called hybrid model and outline the work flow of the presented predictor-corrector framework. A beam expander is assembled as demonstrator for experimental verification of the framework. The optical setup consists of a laser, two bi-convex spherical lenses each mounted to a five degree-of-freedom stage to misalign and correct components, and a Shack-Hartmann sensor for wavefront measurements.

Sequential recognition of the pre-mRNA branch point by U2AF65 and a novel spliceosome-associated 28-kDa protein.

PubMed Central

Gaur, R K; Valcárcel, J; Green, M R

1995-01-01

Splicing of pre-mRNAs occurs via a lariat intermediate in which an intronic adenosine, embedded within a branch point sequence, forms a 2',5'-phosphodiester bond (RNA branch) with the 5' end of the intron. How the branch point is recognized and activated remains largely unknown. Using site-specific photochemical cross-linking, we have identified two proteins that specifically interact with the branch point during the splicing reaction. U2AF65, an essential splicing factor that binds to the adjacent polypyrimidine tract, crosslinks to the branch point at the earliest stage of spliceosome formation in an ATP-independent manner. A novel 28-kDa protein, which is a constituent of the mature spliceosome, contacts the branch point after the first catalytic step. Our results indicate that the branch point is sequentially recognized by distinct splicing factors in the course of the splicing reaction. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 PMID:7493318

Spatial expression of Hox cluster genes in the ontogeny of a sea urchin

NASA Technical Reports Server (NTRS)

Arenas-Mena, C.; Cameron, A. R.; Davidson, E. H.

2000-01-01

The Hox cluster of the sea urchin Strongylocentrous purpuratus contains ten genes in a 500 kb span of the genome. Only two of these genes are expressed during embryogenesis, while all of eight genes tested are expressed during development of the adult body plan in the larval stage. We report the spatial expression during larval development of the five 'posterior' genes of the cluster: SpHox7, SpHox8, SpHox9/10, SpHox11/13a and SpHox11/13b. The five genes exhibit a dynamic, largely mesodermal program of expression. Only SpHox7 displays extensive expression within the pentameral rudiment itself. A spatially sequential and colinear arrangement of expression domains is found in the somatocoels, the paired posterior mesodermal structures that will become the adult perivisceral coeloms. No such sequential expression pattern is observed in endodermal, epidermal or neural tissues of either the larva or the presumptive juvenile sea urchin. The spatial expression patterns of the Hox genes illuminate the evolutionary process by which the pentameral echinoderm body plan emerged from a bilateral ancestor.

Sequential high intensity focused ultrasound (HIFU) ablation in the treatment of benign multinodular goitre: an observational retrospective study.

PubMed

Lang, Brian H H; Woo, Yu-Cho; Chiu, Keith Wan-Hang

2018-03-19

Assessing the efficacy and safety of sequential high-intensity focused ultrasound (HIFU) ablation in a multinodular goitre (MNG) by comparing them with single HIFU ablation. One hundred and four (84.6%) patients underwent single ablation of a single nodule (group I), while 19 (15.4%) underwent sequential ablation of two relatively-dominant nodules in a MNG (group II). Extent of shrinkage per nodule [by volume reduction ratio (VRR)], pain scores (by 0-10 visual analogue scale) during and after ablation, and rate of vocal cord palsy (VCP), skin burn and nausea/vomiting were compared between the two groups. All 19 (100%) sequential ablations completed successfully. The 3- and 6-month VRR of each nodule were comparable between the two groups (p > 0.05) and in group II, the 3- and 6-month VRR between the first and second nodules were comparable (p = 0.710 and p = 0.548, respectively). Pain score was significantly higher in group II in the morning after ablation (2.29 vs 1.15, p = 0.047) and nausea/vomiting occurred significantly more frequently in group II (15.8% vs 0.0%, p = 0.012). However, VCP and skin burn were comparable (p > 0.05). Sequential ablation had comparable efficacy and safety as single ablation. However, patients undergoing sequential ablation are at higher likelihood of pain in the following morning and nausea/vomiting after ablation. • Sequential HIFU ablation is well-tolerated in patients with two dominant thyroid nodules • More pain is experienced in the morning following sequential HIFU ablation • More nausea/vomiting is experienced following sequential HIFU ablation.

Sequential cloud-point extraction for toxicological screening analysis of medicaments in human plasma by high pressure liquid chromatography with diode array detector.

PubMed

Madej, Katarzyna; Persona, Karolina; Wandas, Monika; Gomółka, Ewa

2013-10-18

A complex extraction system with the use of cloud-point extraction technique (CPE) was developed for sequential isolation of basic and acidic/neutral medicaments from human plasma/serum, screened by HPLC/DAD method. Eight model drugs (paracetamol, promazine, chlorpromazine, amitriptyline, salicyclic acid, opipramol, alprazolam and carbamazepine) were chosen for the study of optimal CPE conditions. The CPE technique consists in partition of an aqueous sample with addition of a surfactant into two phases: micelle-rich phase with the isolated compounds and water phase containing a surfactant below the critical micellar concentration, mainly under influence of temperature change. The proposed extraction system consists of two chief steps: isolation of basic compounds (from pH 12) and then isolation of acidic/neutral compounds (from pH 6) using surfactant Triton X-114 as the extraction medium. Extraction recovery varied from 25.2 to 107.9% with intra-day and inter-day precision (RSD %) ranged 0.88-1087 and 5.32-17.96, respectively. The limits of detection for the studied medicaments at λ 254nm corresponded to therapeutic or low toxic plasma concentration levels. Usefulness of the proposed CPE-HPLC/DAD method for toxicological drug screening was tested via its application to analysis of two serum samples taken from patients suspected of drug overdosing. Published by Elsevier B.V.

Knee Kinematics is Altered Post-Fatigue While Performing a Crossover Task

PubMed Central

Cortes, Nelson; Greska, Eric; Ambegaonkar, Jatin P.; Kollock, Roger O.; Caswell, Shane V.; Onate, James A.

2013-01-01

Purpose To examine the effect of a sequential fatigue protocol on lower extremity biomechanics during a crossover cutting task in female soccer players. Methods Eighteen female collegiate soccer players alternated between a fatigue protocol and two consecutive unanticipated crossover trials until fatigue was reached. Lower extremity biomechanics were evaluated during the crossover using a 3D motion capture system and two force plates. Repeated measures ANOVAs analyzed differences between three sequential stages of fatigue (pre, 50%, 100%) for each dependent variable (α=0.05). Results Knee flexion angles at initial contact (IC) for pre- (−32±9°) and 50% (−29±11°) were significantly higher than at 100% fatigue (−22±9°) (p<0.001 and p=0.015, respectively). Knee adduction angles at IC for pre- (9±5°) and 50% (8±4°) were significantly higher (p=0.006 and p=0.049, respectively) than at 100% fatigue (6±4°). Conclusions Fatigue altered sagittal and frontal knee kinematics after 50% fatigue whereupon participants had diminished knee control at initial contact. Interventions should attempt to reduce the negative effects of fatigue on lower extremity biomechanics by promotion appropriate frontal plane alignment, and increased knee flexion during fatigue status. PMID:24045915

A comparison of two worlds: How does Bayes hold up to the status quo for the analysis of clinical trials?

PubMed

Pressman, Alice R; Avins, Andrew L; Hubbard, Alan; Satariano, William A

2011-07-01

There is a paucity of literature comparing Bayesian analytic techniques with traditional approaches for analyzing clinical trials using real trial data. We compared Bayesian and frequentist group sequential methods using data from two published clinical trials. We chose two widely accepted frequentist rules, O'Brien-Fleming and Lan-DeMets, and conjugate Bayesian priors. Using the nonparametric bootstrap, we estimated a sampling distribution of stopping times for each method. Because current practice dictates the preservation of an experiment-wise false positive rate (Type I error), we approximated these error rates for our Bayesian and frequentist analyses with the posterior probability of detecting an effect in a simulated null sample. Thus for the data-generated distribution represented by these trials, we were able to compare the relative performance of these techniques. No final outcomes differed from those of the original trials. However, the timing of trial termination differed substantially by method and varied by trial. For one trial, group sequential designs of either type dictated early stopping of the study. In the other, stopping times were dependent upon the choice of spending function and prior distribution. Results indicate that trialists ought to consider Bayesian methods in addition to traditional approaches for analysis of clinical trials. Though findings from this small sample did not demonstrate either method to consistently outperform the other, they did suggest the need to replicate these comparisons using data from varied clinical trials in order to determine the conditions under which the different methods would be most efficient. Copyright © 2011 Elsevier Inc. All rights reserved.

A comparison of two worlds: How does Bayes hold up to the status quo for the analysis of clinical trials?

PubMed Central

Pressman, Alice R.; Avins, Andrew L.; Hubbard, Alan; Satariano, William A.

2014-01-01

Background There is a paucity of literature comparing Bayesian analytic techniques with traditional approaches for analyzing clinical trials using real trial data. Methods We compared Bayesian and frequentist group sequential methods using data from two published clinical trials. We chose two widely accepted frequentist rules, O'Brien–Fleming and Lan–DeMets, and conjugate Bayesian priors. Using the nonparametric bootstrap, we estimated a sampling distribution of stopping times for each method. Because current practice dictates the preservation of an experiment-wise false positive rate (Type I error), we approximated these error rates for our Bayesian and frequentist analyses with the posterior probability of detecting an effect in a simulated null sample. Thus for the data-generated distribution represented by these trials, we were able to compare the relative performance of these techniques. Results No final outcomes differed from those of the original trials. However, the timing of trial termination differed substantially by method and varied by trial. For one trial, group sequential designs of either type dictated early stopping of the study. In the other, stopping times were dependent upon the choice of spending function and prior distribution. Conclusions Results indicate that trialists ought to consider Bayesian methods in addition to traditional approaches for analysis of clinical trials. Though findings from this small sample did not demonstrate either method to consistently outperform the other, they did suggest the need to replicate these comparisons using data from varied clinical trials in order to determine the conditions under which the different methods would be most efficient. PMID:21453792

Study of shallow junction formation by boron-containing cluster ion implantation of silicon and two-stage annealing

NASA Astrophysics Data System (ADS)

Lu, Xin-Ming

Shallow junction formation made by low energy ion implantation and rapid thermal annealing is facing a major challenge for ULSI (ultra large scale integration) as the line width decreases down to the sub micrometer region. The issues include low beam current, the channeling effect in low energy ion implantation and TED (transient enhanced diffusion) during annealing after ion implantation. In this work, boron containing small cluster ions, such as GeB, SiB and SiB2, was generated by using the SNICS (source of negative ion by cesium sputtering) ion source to implant into Si substrates to form shallow junctions. The use of boron containing cluster ions effectively reduces the boron energy while keeping the energy of the cluster ion beam at a high level. At the same time, it reduces the channeling effect due to amorphization by co-implanted heavy atoms like Ge and Si. Cluster ions have been used to produce 0.65--2keV boron for low energy ion implantation. Two stage annealing, which is a combination of low temperature (550°C) preannealing and high temperature annealing (1000°C), was carried out to anneal the Si sample implanted by GeB, SiBn clusters. The key concept of two-step annealing, that is, the separation of crystal regrowth, point defects removal with dopant activation from dopant diffusion, is discussed in detail. The advantages of the two stage annealing include better lattice structure, better dopant activation and retarded boron diffusion. The junction depth of the two stage annealed GeB sample was only half that of the one-step annealed sample, indicating that TED was suppressed by two stage annealing. Junction depths as small as 30 nm have been achieved by two stage annealing of sample implanted with 5 x 10-4/cm2 of 5 keV GeB at 1000°C for 1 second. The samples were evaluated by SIMS (secondary ion mass spectrometry) profiling, TEM (transmission electron microscopy) and RBS (Rutherford Backscattering Spectrometry)/channeling. Cluster ion implantation in combination with two-step annealing is effective in fabricating ultra-shallow junctions.

Missing observations in multiyear rotation sampling designs

NASA Technical Reports Server (NTRS)

Gbur, E. E.; Sielken, R. L., Jr. (Principal Investigator)

1982-01-01

Because Multiyear estimation of at-harvest stratum crop proportions is more efficient than single year estimation, the behavior of multiyear estimators in the presence of missing acquisitions was studied. Only the (worst) case when a segment proportion cannot be estimated for the entire year is considered. The effect of these missing segments on the variance of the at-harvest stratum crop proportion estimator is considered when missing segments are not replaced, and when missing segments are replaced by segments not sampled in previous years. The principle recommendations are to replace missing segments according to some specified strategy, and to use a sequential procedure for selecting a sampling design; i.e., choose an optimal two year design and then, based on the observed two year design after segment losses have been taken into account, choose the best possible three year design having the observed two year parent design.

Synergistic effect of nanotopography and bioactive ions on peri-implant bone response

PubMed Central

Su, Yingmin; Komasa, Satoshi; Li, Peiqi; Nishizaki, Mariko; Chen, Luyuan; Terada, Chisato; Yoshimine, Shigeki; Nishizaki, Hiroshi; Okazaki, Joji

2017-01-01

Both bioactive ion chemistry and nanoscale surface modifications are beneficial for enhanced osseointegration of endosseous implants. In this study, a facile synthesis approach to the incorporation of bioactive Ca2+ ions into the interlayers of nanoporous structures (Ca-nano) formed on a Ti6Al4V alloy surface was developed by sequential chemical and heat treatments. Samples with a machined surface and an Na+ ion-incorporated nanoporous surface (Na-nano) fabricated by concentrated alkali and heat treatment were used in parallel for comparison. The bone response was investigated by microcomputed tomography assessment, sequential fluorescent labeling analysis, and histological and histomorphometric evaluation after 8 weeks of implantation in rat femurs. No significant differences were found in the nanotopography, surface roughness, or crystalline properties of the Ca-nano and Na-nano surfaces. Bone–implant contact was better in the Ca-nano and Na-nano implants than in the machined implant. The Ca-nano implant was superior to the Na-nano implant in terms of enhancing the volume of new bone formation. The bone formation activity consistently increased for the Ca-nano implant but ceased for the Na-nano implant in the late healing stage. These results suggest that Ca-nano implants have promising potential for application in dentistry and orthopedics. PMID:28184162

Two-color above-threshold and two-photon sequential double ionization beyond the dipole approximation

NASA Astrophysics Data System (ADS)

Grum-Grzhimailo, A. N.; Gryzlova, E. V.; Kuzmina, E. I.; Chetverkina, A. S.; Strakhova, S. I.

2015-04-01

Two nonlinear atomic photoprocesses are theoretically considered with the emphasis on the photoelectron angular distributions and their modifications due to violation of the dipole approximation: sequential two-photon double ionization and two-color above threshold ionization. These reactions are now accessible with X-ray free electron lasers. Both processes are exemplified by the ionization of krypton: from the 4p shell in the sequential two-photon double ionization and from the 2s shell in the two-color above-threshold ionization, which are compared to the Ar(3p) and Ne(1s) ionization, respectively. Noticeable nondipole effects are predicted.

Ethanol production from bamboo using mild alkaline pre-extraction followed by alkaline hydrogen peroxide pretreatment.

PubMed

Yuan, Zhaoyang; Wen, Yangbing; Kapu, Nuwan Sella

2018-01-01

A sequential two-stage pretreatment process comprising alkaline pre-extraction and alkaline hydrogen peroxide pretreatment (AHP) was investigated to convert bamboo carbohydrates into bioethanol. The results showed that mild alkaline pre-extraction using 8% (w/w) sodium hydroxide (NaOH) at 100°C for 180min followed by AHP pretreatment with 4% (w/w) hydrogen peroxide (H 2 O 2 ) was sufficient to generate a substrate that could be efficiently digested with low enzyme loadings. Moreover, alkali pre-extraction enabled the use of lower H 2 O 2 charges in AHP treatment. Two-stage pretreatment followed by enzymatic hydrolysis with only 9FPU/g cellulose led to the recovery of 87% of the original sugars in the raw feedstock. The use of the pentose-hexose fermenting Saccharomyces cerevisiae SR8u strain enabled the utilization of 95.7% sugars in the hydrolysate to reach 4.6%w/v ethanol titer. The overall process also enabled the recovery of 62.9% lignin and 93.8% silica at high levels of purity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Two stages of directed forgetting: Electrophysiological evidence from a short-term memory task.

PubMed

Gao, Heming; Cao, Bihua; Qi, Mingming; Wang, Jing; Zhang, Qi; Li, Fuhong

2016-06-01

In this study, a short-term memory test was used to investigate the temporal course and neural mechanism of directed forgetting under different memory loads. Within each trial, two memory items with high or low load were presented sequentially, followed by a cue indicating whether the presented items should be remembered. After an interval, subjects were asked to respond to the probe stimuli. The ERPs locked to the cues showed that (a) the effect of cue type was initially observed during the P2 (160-240 ms) time window, with more positive ERPs for remembering relative to forgetting cues; (b) load effects were observed during the N2-P3 (250-500 ms) time window, with more positive ERPs for the high-load than low-load condition; (c) the cue effect was also observed during the N2-P3 time window, with more negative ERPs for forgetting versus remembering cues. These results demonstrated that directed forgetting involves two stages: task-relevance identification and information discarding. The cue effects during the N2 epoch supported the view that directed forgetting is an active process. © 2016 Society for Psychophysiological Research.

STOPDVTs: Development and testing of a clinical assessment tool to guide nursing assessment of postoperative patients for Deep Vein Thrombosis.

PubMed

O'Brien, Alanna; Redley, Bernice; Wood, Beverley; Botti, Mari; Hutchinson, Anastasia F

2018-03-01

To develop and test a clinical tool to guide nurses' assessment of postoperative patients for Deep Vein Thrombosis. Preventing venous thromboembolism in hospitalised patients is an international patient safety priority. Despite high-level evidence for optimal venous thromboembolism prophylaxis, implementation is inconsistent and the incidence of Deep Vein Thrombosis remains high. A two-stage sequential multi-method design was used. In stage 1, the STOPDVTs tool was developed using a review of the literature and focus groups with local clinical experts. Stage 2 involved pilot testing the tool with 38 surgical nurses who conducted repeated assessments on a prospective sample of 50 postoperative orthopaedic patients. Stage 1: The focus group members who were members of the nursing leadership team agreed on eight local and systemic signs and symptoms that should be included in a nursing patient assessment tool for early Deep Vein Thrombosis. Local symptoms were pain in the limbs, calf swelling and tightness, changes in the affected limb's skin temperature. Systemic signs included in the tool were as follows: increased shortness of breath, increased respiratory and heart rates, and decreased oxygen saturation. Stage 2: The STOPDVTs tool had acceptable face and content validity, the agreement between the expert nurse and surgical nurses on assessments of individual signs and symptoms varied between 44%-94%. Surgical nurses were less likely than the expert nurse to identify signs indicative of Deep Vein Thrombosis. Despite finding the STOPDVTs clinical assessment tool was a useful guide for nursing assessment, surgical nurses often underestimated the potential importance of clinical signs. The findings reveal a gap in nursing knowledge and skill in assessing for Deep Vein Thrombosis in postoperative orthopaedic patients. This study identified a possible risk to patient safety related to under-recognition of the signs and symptoms of possible Deep Vein Thrombosis (DVT) in postoperative orthopaedic patients. The findings demonstrate the feasibility of developing and implementing a protocol for consistent screening by nurses for possible DVT in the postoperative period. © 2018 John Wiley & Sons Ltd.

Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

USGS Publications Warehouse

Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

2011-01-01

Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

Phosphorus Concentrations in Sequentially Fractionated Soil Samples as Affected by Digestion Methods

PubMed Central

do Nascimento, Carlos A. C.; Pagliari, Paulo H.; Schmitt, Djalma; He, Zhongqi; Waldrip, Heidi

2015-01-01

Sequential fractionation has helped improving our understanding of the lability and bioavailability of P in soil. Nevertheless, there have been no reports on how manipulation of the different fractions prior to analyses affects the total P (TP) concentrations measured. This study investigated the effects of sample digestion, filtration, and acidification on the TP concentrations determined by ICP-OES in 20 soil samples. Total P in extracts were either determined without digestion by ICP-OES, or ICP-OES following block digestion, or autoclave digestion. The effects of sample filtration, and acidification on undigested alkaline extracts prior to ICP-OES were also evaluated. Results showed that, TP concentrations were greatest in the block-digested extracts, though the variability introduced by the block-digestion was the highest. Acidification of NaHCO3 extracts resulted in lower TP concentrations, while acidification of NaOH randomly increased or decreased TP concentrations. The precision observed with ICP-OES of undigested extracts suggests this should be the preferred method for TP determination in sequentially extracted samples. Thus, observations reported in this work would be helpful in appropriate sample handling for P determination, thereby improving the precision of P determination. The results are also useful for literature data comparison and discussion when there are differences in sample treatments. PMID:26647644

Effectiveness of the Treatment Readiness and Induction Program for increasing adolescent motivation for change.

PubMed

Becan, Jennifer E; Knight, Danica K; Crawley, Rachel D; Joe, George W; Flynn, Patrick M

2015-03-01

Success in substance abuse treatment is improved by problem recognition, desire to seek help, and readiness to engage in treatment, all of which are important aspects of motivation. Interventions that facilitate these at treatment induction for adolescents are especially needed. The purpose of this study is to assess the effectiveness of TRIP (Treatment Readiness and Induction Program) in promoting treatment motivation. Data represent 519 adolescents from 6 residential programs who completed assessments at treatment intake (time 1) and 35 days after admission (time 2). The design consisted of a comparison sample (n=281) that had enrolled in treatment prior to implementation of TRIP (standard operating practice) and a sample of clients that had entered treatment after TRIP began and received standard operating practice enhanced by TRIP (n=238). Repeated measures ANCOVAs were conducted using each time 2 motivation scale as a dependent measure. Motivation scales were conceptualized as representing sequential stages of change. LISREL was used to test a structural model involving TRIP participation, gender, drug use severity, juvenile justice involvement, age, race-ethnicity, prior treatment, and urgency as predictors of the stages of treatment motivation. Compared to standard practice, adolescents receiving TRIP demonstrated greater gains in problem recognition, even after controlling for the other variables in the model. The model fit was adequate, with TRIP directly affecting problem recognition and indirectly affecting later stages of change (desire for help and treatment readiness). Future studies should examine which specific components of TRIP affect change in motivation. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in hydrogen isotope ratios in sequential plumage stages: an implication for the creation of isotope-base maps for tracking migratory birds.

PubMed

Duxbury, J M; Holroyd, G L; Muehlenbachs, K

2003-09-01

Accurate reference maps are important in the use of stable-isotopes to track the movements of migratory birds. Reference maps created by the analysis of samples collected from young at the nest site are more accurate than simply referring to naturally occurring patterns of hydrogen isotope ratios created by precipitation cycles. Ratios of hydrogen isotopes in the nutrients incorporated early in the development of young birds can be derived from endogenous, maternal sources. Base-maps should be created with the analysis of tissue samples from hatchlings after local the isotopic signature of exogenous nutrients is dominant. Migratory species such as Peregrine Falcons are known to use endogenous sources in the creation of their eggs, therefore knowledge of what plumage stage best represents the local hydrogen ratios would assist in the planning of nest visits. We conducted diet manipulation experiments involving Japanese Quail and Peregrine Falcons to determine the plumage stage when hydrogen isotope ratios were indicative of a switch in their food source. The natal down of both the quail and falcons reflected the diet of breeding adult females. The hydrogen isotope ratios of a new food source were dominant in the juvenile down of the young falcons, although a further shift was detected in the final juvenile plumage. The juvenile plumage is grown during weeks 3-4 after hatch on Peregrine Falcons. Nest visits for the purpose of collecting feathers for isotope-base-map creation should be made around 4 weeks after the presumed hatch of the young falcons.

Antioxidant activity and protective effect of banana peel against oxidative hemolysis of human erythrocyte at different stages of ripening.

PubMed

Sundaram, Shanthy; Anjum, Shadma; Dwivedi, Priyanka; Rai, Gyanendra Kumar

2011-08-01

Phytochemicals such as polyphenols and carotenoids are gaining importance because of their contribution to human health and their multiple biological effects such as antioxidant, antimutagenic, anticarcinogenic, and cytoprotective activities and their therapeutic properties. Banana peel is a major by-product in pulp industry and it contains various bioactive compounds like polyphenols, carotenoids, and others. In the present study, effect of ripening, solvent polarity on the content of bioactive compounds of crude banana peel and the protective effect of peel extracts of unripe, ripe, and leaky ripe banana fruit on hydrogen peroxide-induced hemolysis and their antioxidant capacity were investigated. Banana (Musa paradisica) peel at different stages of ripening (unripe, ripe, leaky ripe) were treated with 70% acetone, which were partitioned in order of polarity with water, ethyl acetate, chloroform (CHCl₃), and hexane sequentially. The antioxidant activity of the samples was evaluated by the red cell hemolysis assay, free radical scavenging (1,1-diphenyl-2-picrylhydrazyl free radical elimination) and superoxide dismutase activities. The Folin-Ciocalteu's reagent assay was used to estimate the phenolic content of extracts. The findings of this investigation suggest that the unripe banana peel sample had higher antioxidant potency than ripe and leaky ripe. Further on fractionation, ethyl acetate and water soluble fractions of unripe peel displayed high antioxidant activity than CHCl₃ and hexane fraction, respectively. A positive correlation between free radical scavenging capacity and the content of phenolic compound were found in unripe, ripe, and leaky ripe stages of banana peel.

Evaluation of Bayesian Sequential Proportion Estimation Using Analyst Labels

NASA Technical Reports Server (NTRS)

Lennington, R. K.; Abotteen, K. M. (Principal Investigator)

1980-01-01

The author has identified the following significant results. A total of ten Large Area Crop Inventory Experiment Phase 3 blind sites and analyst-interpreter labels were used in a study to compare proportional estimates obtained by the Bayes sequential procedure with estimates obtained from simple random sampling and from Procedure 1. The analyst error rate using the Bayes technique was shown to be no greater than that for the simple random sampling. Also, the segment proportion estimates produced using this technique had smaller bias and mean squared errors than the estimates produced using either simple random sampling or Procedure 1.

Effects of model complexity and priors on estimation using sequential importance sampling/resampling for species conservation

USGS Publications Warehouse

Dunham, Kylee; Grand, James B.

2016-01-01

We examined the effects of complexity and priors on the accuracy of models used to estimate ecological and observational processes, and to make predictions regarding population size and structure. State-space models are useful for estimating complex, unobservable population processes and making predictions about future populations based on limited data. To better understand the utility of state space models in evaluating population dynamics, we used them in a Bayesian framework and compared the accuracy of models with differing complexity, with and without informative priors using sequential importance sampling/resampling (SISR). Count data were simulated for 25 years using known parameters and observation process for each model. We used kernel smoothing to reduce the effect of particle depletion, which is common when estimating both states and parameters with SISR. Models using informative priors estimated parameter values and population size with greater accuracy than their non-informative counterparts. While the estimates of population size and trend did not suffer greatly in models using non-informative priors, the algorithm was unable to accurately estimate demographic parameters. This model framework provides reasonable estimates of population size when little to no information is available; however, when information on some vital rates is available, SISR can be used to obtain more precise estimates of population size and process. Incorporating model complexity such as that required by structured populations with stage-specific vital rates affects precision and accuracy when estimating latent population variables and predicting population dynamics. These results are important to consider when designing monitoring programs and conservation efforts requiring management of specific population segments.

Phosphorus concentrations in sequentially fractionated soil samples as affected by digestion methods

USDA-ARS?s Scientific Manuscript database

Sequential fractionation has been used for several decades for improving our understanding on the effects of agricultural practices and management on the lability and bioavailability of phosphorus in soil, manure, and other soil amendments. Nevertheless, there have been no reports on how manipulatio...

The sequential injection system with adsorptive stripping voltammetric detection.

PubMed

Kubiak, W W; Latonen, R M; Ivaska, A

2001-03-16

Two sequential injection systems have been developed for adsorptive stripping voltammetric measurement. One is for substances adsorbing at mercury, e.g. riboflavin. In this case, a simple arrangement with only sample aspiration is needed. Reproducibility was 3% and detection limit 0.07 muM. The measuring system was applied to determination of riboflavin in vitamin pills and to study the photodegradation process of riboflavin in aqueous solutions. In the second case, metal ions were determined. They have to be complexed before deposition on the mercury surface. Thus, both the sample and the ligand have to be aspirated in the system. In this case, the reproducibility was approximately 6% and the detection limit <0.1 ppm for cadmium, lead and copper when complexation with oxine was used. Dimethylglyoxime was used in determination of nickel and cobalt and nioxime complexes were used in determination of nickel and copper. With these complexing agents, the reproducibility was the same as with oxine, but the metals could be determined at concentrations lower than 0.01 ppm. Application of two ligands in a SIA system with AdSV detection was also studied. Simultaneous determination of copper, lead, cadmium and cobalt was possible by using oxine and dimethylglyoxime. Copper and nickel were simultaneously determined by using dimethylglyoxime and nioxime.

A two-stage design for multiple testing in large-scale association studies.

PubMed

Wen, Shu-Hui; Tzeng, Jung-Ying; Kao, Jau-Tsuen; Hsiao, Chuhsing Kate

2006-01-01

Modern association studies often involve a large number of markers and hence may encounter the problem of testing multiple hypotheses. Traditional procedures are usually over-conservative and with low power to detect mild genetic effects. From the design perspective, we propose a two-stage selection procedure to address this concern. Our main principle is to reduce the total number of tests by removing clearly unassociated markers in the first-stage test. Next, conditional on the findings of the first stage, which uses a less stringent nominal level, a more conservative test is conducted in the second stage using the augmented data and the data from the first stage. Previous studies have suggested using independent samples to avoid inflated errors. However, we found that, after accounting for the dependence between these two samples, the true discovery rate increases substantially. In addition, the cost of genotyping can be greatly reduced via this approach. Results from a study of hypertriglyceridemia and simulations suggest the two-stage method has a higher overall true positive rate (TPR) with a controlled overall false positive rate (FPR) when compared with single-stage approaches. We also report the analytical form of its overall FPR, which may be useful in guiding study design to achieve a high TPR while retaining the desired FPR.

Phylogenetic analysis accounting for age-dependent death and sampling with applications to epidemics.

PubMed

Lambert, Amaury; Alexander, Helen K; Stadler, Tanja

2014-07-07

The reconstruction of phylogenetic trees based on viral genetic sequence data sequentially sampled from an epidemic provides estimates of the past transmission dynamics, by fitting epidemiological models to these trees. To our knowledge, none of the epidemiological models currently used in phylogenetics can account for recovery rates and sampling rates dependent on the time elapsed since transmission, i.e. age of infection. Here we introduce an epidemiological model where infectives leave the epidemic, by either recovery or sampling, after some random time which may follow an arbitrary distribution. We derive an expression for the likelihood of the phylogenetic tree of sampled infectives under our general epidemiological model. The analytic concept developed in this paper will facilitate inference of past epidemiological dynamics and provide an analytical framework for performing very efficient simulations of phylogenetic trees under our model. The main idea of our analytic study is that the non-Markovian epidemiological model giving rise to phylogenetic trees growing vertically as time goes by can be represented by a Markovian "coalescent point process" growing horizontally by the sequential addition of pairs of coalescence and sampling times. As examples, we discuss two special cases of our general model, described in terms of influenza and HIV epidemics. Though phrased in epidemiological terms, our framework can also be used for instance to fit macroevolutionary models to phylogenies of extant and extinct species, accounting for general species lifetime distributions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Decoupling of mass transport mechanisms in the stagewise swelling of multiple emulsions.

PubMed

Bahtz, Jana; Gunes, Deniz Z; Hughes, Eric; Pokorny, Lea; Riesch, Francesca; Syrbe, Axel; Fischer, Peter; Windhab, Erich J

2015-05-19

This contribution reports on the mass transport kinetics of osmotically imbalanced water-in-oil-in-water (W1/O/W2) emulsions. Although frequently studied, the control of mass transport in W1/O/W2 emulsions is still challenging. We describe a microfluidics-based method to systematically investigate the impact of various parameters, such as osmotic pressure gradient, oil phase viscosity, and temperature, on the mass transport. Combined with optical microscopy analyses, we are able to identify and decouple the various mechanisms, which control the dynamic droplet size of osmotically imbalanced W1/O/W2 emulsions. So, swelling kinetics curves with a very high accuracy are generated, giving a basis for quantifying the kinetic aspects of transport. Two sequential swelling stages, i.e., a lag stage and an osmotically dominated stage, with different mass transport mechanisms are identified. The determination and interpretation of the different stages are the prerequisite to control and trigger the swelling process. We show evidence that both mass transport mechanisms can be decoupled from each other. Rapid osmotically driven mass transport only takes place in a second stage induced by structural changes of the oil phase in a lag stage, which allow an osmotic exchange between both water phases. Such structural changes are strongly facilitated by spontaneous water-in-oil emulsification. The duration of the lag stage is pressure-independent but significantly influenced by the oil phase viscosity and temperature.

Ascent performance feasibility for next-generation spacecraft

NASA Astrophysics Data System (ADS)

Mancuso, Salvatore Massimo

This thesis deals with the optimization of the ascent trajectories for single-stage suborbital (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem has been solved using the sequential gradient-restoration algorithm. For the TSTO case, some modifications to the original version of the algorithm have been necessary in order to deal with discontinuities due to staging and the fact that the functional being minimized depends on interface conditions. The optimization problem is studied for different values of the initial thrust-to-weight ratio in the range 1.3 to 1.6, engine specific impulse in the range 400 to 500 sec, and spacecraft structural factor in the range 0.08 to 0.12. For the TSTO configuration, two subproblems are studied: uniform structural factor between stages and nonuniform structural factor between stages. Due to the regular behavior of the results obtained, engineering approximations have been developed which connect the maximum payload weight to the engine specific impulse and spacecraft structural factor; in turn, this leads to useful design considerations. Also, performance sensitivity to the scale of the aerodynamic drag is studied, and it is shown that its effect on payload weight is relatively small, even for drag changes approaching ± 50%. The main conclusions are that: the design of a SSSO configuration appears to be feasible; the design of a SSTO configuration might be comfortably feasible, marginally feasible, or unfeasible, depending on the parameter values assumed; the design of a TSTO configuration is not only feasible, but its payload appears to be considerably larger than that of a SSTO configuration. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, it appears that aerodynamic improvements do not yield significant improvements in payload weight.

Proteomic biomarkers apolipoprotein A1, truncated transthyretin and connective tissue activating protein III enhance the sensitivity of CA125 for detecting early stage epithelial ovarian cancer.

PubMed

Clarke, Charlotte H; Yip, Christine; Badgwell, Donna; Fung, Eric T; Coombes, Kevin R; Zhang, Zhen; Lu, Karen H; Bast, Robert C

2011-09-01

The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P=0.015, McNemar's test). Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. Copyright © 2011. Published by Elsevier Inc.

Proteomic Biomarkers Apolipoprotein A1, Truncated Transthyretin and Connective Tissue Activating Protein III Enhance the Sensitivity of CA125 for Detecting Early Stage Epithelial Ovarian Cancer

PubMed Central

Clarke, Charlotte H.; Yip, Christine; Badgwell, Donna; Fung, Eric T.; Coombes, Kevin R.; Zhang, Zhen; Lu, Karen H.; Bast, Robert C.

2011-01-01

Objective The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Methods Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. Results In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P= 0.015, McNemar's test). Conclusion Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. PMID:21708402

Adjuvant chemotherapy with sequential cytokine-induced killer (CIK) cells in stage IB non-small cell lung cancer.

PubMed

Li, Da-Peng; Li, Wei; Feng, Jun; Chen, Kai; Tao, Min

2015-01-01

For non-small cell lung cancer (NSCLC) patients at stage IB, adjuvant chemotherapy does not improve survival. Evidence suggests that dendritic cell (DC)-activated cytokine-induced killer (DC-CIK) cell therapy in addition to chemotherapy improves survival for stage I-IIIA NSCLC patients after surgery, but there are not enough data to confirm this benefit specifically for those at stage IB. Herein, we retrospectively evaluated the efficacy and safety of this therapy administered to stage IB NSCLC patients. Sixty-six patients were treated with four-cycle adjuvant chemotherapy initiated 3 weeks after surgical resection. In addition, 28 of these patients underwent DC-CIK therapy on a trimonthly basis (average 3.1 times, range 1-6) beginning 1 month after chemotherapy. The disease-free survival (DFS) rates of the two groups were statistically similar, although patients who received DC-CIK therapy showed slightly higher 1- and 2-year DFS rates (100.0% and 96.4%, respectively, compared with 81.6% and 76.3%). More importantly, patients in the DC-CIK therapy group had significantly longer overall survival (p=0.018). For patients who received treatment after recurrence, the DC-CIK therapy group had longer progression-free survival compared with the chemotherapy-only group. In addition, patients given DC-CIK therapy experienced less fatigue and appetite loss. The rate of adverse side effects was similar between the two groups. In conclusion, for these stage IB NSCLC patients, DC-CIK therapy significantly improved 2-year DFS rates compared with those who received chemotherapy only. DC-CIK therapy also benefited patients' quality of life, and adverse events were acceptable.

Optimization of the combined proton acceleration regime with a target composition scheme

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

Yao, W. P.; Graduate School, China Academy of Engineering Physics, Beijing 100088; Li, B. W., E-mail: li-baiwen@iapcm.ac.cn

A target composition scheme to optimize the combined proton acceleration regime is presented and verified by two-dimensional particle-in-cell simulations by using an ultra-intense circularly polarized (CP) laser pulse irradiating an overdense hydrocarbon (CH) target, instead of a pure hydrogen (H) one. The combined acceleration regime is a two-stage proton acceleration scheme combining the radiation pressure dominated acceleration (RPDA) stage and the laser wakefield acceleration (LWFA) stage sequentially together. Protons get pre-accelerated in the first stage when an ultra-intense CP laser pulse irradiating an overdense CH target. The wakefield is driven by the laser pulse after penetrating through the overdense CHmore » target and propagating in the underdense tritium plasma gas. With the pre-accelerate stage, protons can now get trapped in the wakefield and accelerated to much higher energy by LWFA. Finally, protons with higher energies (from about 20 GeV up to about 30 GeV) and lower energy spreads (from about 18% down to about 5% in full-width at half-maximum, or FWHM) are generated, as compared to the use of a pure H target. It is because protons can be more stably pre-accelerated in the first RPDA stage when using CH targets. With the increase of the carbon-to-hydrogen density ratio, the energy spread is lower and the maximum proton energy is higher. It also shows that for the same laser intensity around 10{sup 22} W cm{sup −2}, using the CH target will lead to a higher proton energy, as compared to the use of a pure H target. Additionally, proton energy can be further increased by employing a longitudinally negative gradient of a background plasma density.« less

Improving Hospital-wide Patient Scheduling Decisions by Clinical Pathway Mining.

PubMed

Gartner, Daniel; Arnolds, Ines V; Nickel, Stefan

2015-01-01

Recent research has highlighted the need for solving hospital-wide patient scheduling problems. Inpatient scheduling, patient activities have to be scheduled on scarce hospital resources such that temporal relations between activities (e.g. for recovery times) are ensured. Common objectives are, among others, the minimization of the length of stay (LOS). In this paper, we consider a hospital-wide patient scheduling problem with LOS minimization based on uncertain clinical pathways. We approach the problem in three stages: First, we learn most likely clinical pathways using a sequential pattern mining approach. Second, we provide a mathematical model for patient scheduling and finally, we combine the two approaches. In an experimental study carried out using real-world data, we show that our approach outperforms baseline approaches on two metrics.

A simple GPU-accelerated two-dimensional MUSCL-Hancock solver for ideal magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Bard, Christopher M.; Dorelli, John C.

2014-02-01

We describe our experience using NVIDIA's CUDA (Compute Unified Device Architecture) C programming environment to implement a two-dimensional second-order MUSCL-Hancock ideal magnetohydrodynamics (MHD) solver on a GTX 480 Graphics Processing Unit (GPU). Taking a simple approach in which the MHD variables are stored exclusively in the global memory of the GTX 480 and accessed in a cache-friendly manner (without further optimizing memory access by, for example, staging data in the GPU's faster shared memory), we achieved a maximum speed-up of ≈126 for a 10242 grid relative to the sequential C code running on a single Intel Nehalem (2.8 GHz) core. This speedup is consistent with simple estimates based on the known floating point performance, memory throughput and parallel processing capacity of the GTX 480.

Heat accumulation during sequential cortical bone drilling.

PubMed

Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

2016-03-01

Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from <0.5 °C to nearly 13 °C. The difference between drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Sequential ALK Inhibitors Can Select for Lorlatinib-Resistant Compound ALK Mutations in ALK-Positive Lung Cancer.

PubMed

Yoda, Satoshi; Lin, Jessica J; Lawrence, Michael S; Burke, Benjamin J; Friboulet, Luc; Langenbucher, Adam; Dardaei, Leila; Prutisto-Chang, Kylie; Dagogo-Jack, Ibiayi; Timofeevski, Sergei; Hubbeling, Harper; Gainor, Justin F; Ferris, Lorin A; Riley, Amanda K; Kattermann, Krystina E; Timonina, Daria; Heist, Rebecca S; Iafrate, A John; Benes, Cyril H; Lennerz, Jochen K; Mino-Kenudson, Mari; Engelman, Jeffrey A; Johnson, Ted W; Hata, Aaron N; Shaw, Alice T

2018-06-01

The cornerstone of treatment for advanced ALK-positive lung cancer is sequential therapy with increasingly potent and selective ALK inhibitors. The third-generation ALK inhibitor lorlatinib has demonstrated clinical activity in patients who failed previous ALK inhibitors. To define the spectrum of ALK mutations that confer lorlatinib resistance, we performed accelerated mutagenesis screening of Ba/F3 cells expressing EML4-ALK. Under comparable conditions, N -ethyl- N -nitrosourea (ENU) mutagenesis generated numerous crizotinib-resistant but no lorlatinib-resistant clones harboring single ALK mutations. In similar screens with EML4-ALK containing single ALK resistance mutations, numerous lorlatinib-resistant clones emerged harboring compound ALK mutations. To determine the clinical relevance of these mutations, we analyzed repeat biopsies from lorlatinib-resistant patients. Seven of 20 samples (35%) harbored compound ALK mutations, including two identified in the ENU screen. Whole-exome sequencing in three cases confirmed the stepwise accumulation of ALK mutations during sequential treatment. These results suggest that sequential ALK inhibitors can foster the emergence of compound ALK mutations, identification of which is critical to informing drug design and developing effective therapeutic strategies. Significance: Treatment with sequential first-, second-, and third-generation ALK inhibitors can select for compound ALK mutations that confer high-level resistance to ALK-targeted therapies. A more efficacious long-term strategy may be up-front treatment with a third-generation ALK inhibitor to prevent the emergence of on-target resistance. Cancer Discov; 8(6); 714-29. ©2018 AACR. This article is highlighted in the In This Issue feature, p. 663 . ©2018 American Association for Cancer Research.

The target-to-foils shift in simultaneous and sequential lineups.

PubMed

Clark, Steven E; Davey, Sherrie L

2005-04-01

A theoretical cornerstone in eyewitness identification research is the proposition that witnesses, in making decisions from standard simultaneous lineups, make relative judgments. The present research considers two sources of support for this proposal. An experiment by G. L. Wells (1993) showed that if the target is removed from a lineup, witnesses shift their responses to pick foils, rather than rejecting the lineups, a result we will term a target-to-foils shift. Additional empirical support is provided by results from sequential lineups which typically show higher accuracy than simultaneous lineups, presumably because of a decrease in the use of relative judgments in making identification decisions. The combination of these two lines of research suggests that the target-to-foils shift should be reduced in sequential lineups relative to simultaneous lineups. Results of two experiments showed an overall advantage for sequential lineups, but also showed a target-to-foils shift equal in size for simultaneous and sequential lineups. Additional analyses indicated that the target-to-foils shift in sequential lineups was moderated in part by an order effect and was produced with (Experiment 2) or without (Experiment 1) a shift in decision criterion. This complex pattern of results suggests that more work is needed to understand the processes which underlie decisions in simultaneous and sequential lineups.

Merging parallel tempering with sequential geostatistical resampling for improved posterior exploration of high-dimensional subsurface categorical fields

NASA Astrophysics Data System (ADS)

Laloy, Eric; Linde, Niklas; Jacques, Diederik; Mariethoz, Grégoire

2016-04-01

The sequential geostatistical resampling (SGR) algorithm is a Markov chain Monte Carlo (MCMC) scheme for sampling from possibly non-Gaussian, complex spatially-distributed prior models such as geologic facies or categorical fields. In this work, we highlight the limits of standard SGR for posterior inference of high-dimensional categorical fields with realistically complex likelihood landscapes and benchmark a parallel tempering implementation (PT-SGR). Our proposed PT-SGR approach is demonstrated using synthetic (error corrupted) data from steady-state flow and transport experiments in categorical 7575- and 10,000-dimensional 2D conductivity fields. In both case studies, every SGR trial gets trapped in a local optima while PT-SGR maintains an higher diversity in the sampled model states. The advantage of PT-SGR is most apparent in an inverse transport problem where the posterior distribution is made bimodal by construction. PT-SGR then converges towards the appropriate data misfit much faster than SGR and partly recovers the two modes. In contrast, for the same computational resources SGR does not fit the data to the appropriate error level and hardly produces a locally optimal solution that looks visually similar to one of the two reference modes. Although PT-SGR clearly surpasses SGR in performance, our results also indicate that using a small number (16-24) of temperatures (and thus parallel cores) may not permit complete sampling of the posterior distribution by PT-SGR within a reasonable computational time (less than 1-2 weeks).

Patterning by heritage in mouse molar row development.

PubMed

Prochazka, Jan; Pantalacci, Sophie; Churava, Svatava; Rothova, Michaela; Lambert, Anne; Lesot, Hervé; Klein, Ophir; Peterka, Miroslav; Laudet, Vincent; Peterkova, Renata

2010-08-31

It is known from paleontology studies that two premolars have been lost during mouse evolution. During mouse mandible development, two bud-like structures transiently form that may represent rudimentary precursors of the lost premolars. However, the interpretation of these structures and their significance for mouse molar development are highly controversial because of a lack of molecular data. Here, we searched for typical tooth signaling centers in these two bud-like structures, and followed their fate using molecular markers, 3D reconstructions, and lineage tracing in vitro. Transient signaling centers were indeed found to be located at the tips of both the anterior and posterior rudimentary buds. These centers expressed a similar set of molecular markers as the "primary enamel knot" (pEK), the signaling center of the first molar (M1). These two transient signaling centers were sequentially patterned before and anterior to the M1 pEK. We also determined the dynamics of the M1 pEK, which, slightly later during development, spread up to the field formerly occupied by the posterior transient signaling center. It can be concluded that two rudimentary tooth buds initiate the sequential development of the mouse molars and these have previously been mistaken for early stages of M1 development. Although neither rudiment progresses to form an adult tooth, the posterior one merges with the adjacent M1, which may explain the anterior enlargement of the M1 during mouse family evolution. This study highlights how rudiments of lost structures can stay integrated and participate in morphogenesis of functional organs and help in understanding their evolution, as Darwin suspected long ago.

Administration of Concurrent Vaginal Brachytherapy During Chemotherapy for Treatment of Endometrial Cancer

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

Nagar, Himanshu; Boothe, Dustin; Parikh, Amar

2013-11-15

Purpose: To evaluate the tolerability and toxicity of administering vaginal brachytherapy (VB) concurrently during chemotherapy compared with the sequential approach for patients with endometrial cancer. Methods and Materials: A retrospective analysis of 372 surgically staged patients with endometrial cancer American Joint Committee on Cancer 2009 stages I to IV treated with adjuvant postoperative radiation therapy (RT) at our institution from 2001 to 2012 was conducted. All patients received VB + external beam RT (EBRT) + 6 cycles of adjuvant carboplatin- and paclitaxel-based chemotherapy. The VB mean dose was 15.08 Gy (range, 15-20 Gy), with 3 to 4 weekly applications, andmore » the EBRT mean dose was 45 Gy delivered with 3-dimensional or intensity modulated RT techniques. Hematologic, gastrointestinal (GI), and genitourinary (GU) toxicities were assessed by Common Toxicity Criteria (CTC) and compared between sequential and concurrent chemotherapy and VB schedules. Results: Among patients who received RT and adjuvant chemotherapy, 180 of 372 patients (48%) received RT sandwiched between cycles 3 and 4 of chemotherapy. A separate group of 192 patients (52%) were treated with VB during the first 3 cycles of chemotherapy, with a weekly application on nonchemotherapy days, and received the EBRT portion in a sandwiched fashion. Patients treated with VB during chemotherapy had a decreased overall treatment time by 4 weeks (P<.001; 95% confidence interval: 3.99-4.02) and sustained no difference in CTC-graded acute hematologic, GI, or GU toxicities in comparison with the patients treated with VB and chemotherapy in a sequential manner (P>.05). CTC grade 3 or 4 hematologic, GI, and GU toxicities were zero. Conclusions: VB during chemotherapy is well tolerated, decreases overall treatment time, and does not render more toxicity than the sequential regimen.« less

[Administration of Palonosetron and Phenotropil for Prophylaxis of the N-V-D Stage of Acute Radiation Syndrome].

PubMed

Drachouv, I S; Bykov, V N; Seleznev, A B

2016-01-01

Experiments on small (rats) and large (dogs) animals have shown that a sequential administration of Palonosetron and Phenotropil decreases the intensity of the main manifestations of the N-V-D stage of acute radiation syndrome. These data show the appropriateness of a combined administration of Palonosetron and Phenotropil to prevent a reduced work capacity in the individuals participating in elimination of the consequences of accidents associated with overexposure to radiation.

ASSESSMENT OF A SEQUENTIAL EXTRACTION PROCEDURE FOR PERTURBED LEAD-CONTAMINATED SAMPLES WITH AND WITHOUT PHOSPHOROUS AMENDMENTS

EPA Science Inventory

Sequential extraction procedures are used to determine the solid-phase association in which elements of interest exist in soil and sediment matrices. Foundational work by Tessier et al. (1) has found widespread acceptance and has worked tolerably as an operational definition for...

Sequential Requests and the Problem of Message Sampling.

ERIC Educational Resources Information Center

Cantrill, James Gerard

S. Jackson and S. Jacobs's criticism of "single message" designs in communication research served as a framework for a study that examined the differences between various sequential request paradigms. The study sought to answer the following questions: (1) What were the most naturalistic request sequences assured to replicate…

Phosphorus concentrations in sequentially fractionated soil samples as affected by digestion methods

USDA-ARS?s Scientific Manuscript database

Sequential fractionation has been used for several decades for improving our understanding on the effects of agricultural practices and management on the lability and bioavailability of P in soil, manure, and other soil amendments. Nevertheless, there have been no reports on how manipulation of diff...

Radiotherapy timing in the treatment of limited-stage small cell lung cancer: the impact of thoracic and brain irradiation on survival.

PubMed

Scotti, Vieri; Meattini, Icro; Franzese, Ciro; Saieva, Calogero; Bertocci, Silvia; Meacci, Fiammetta; Furfaro, Ilaria; Scartoni, Daniele; Cecchini, Sara; Desideri, Isacco; Ferrari, Katia; Bruni, Alessio; De Luca Cardillo, Carla; Bastiani, Paolo; Agresti, Benedetta; Mangoni, Monica; Livi, Lorenzo; Biti, Giampaolo

2014-01-01

Small cell lung cancer is an aggressive histologic subtype of lung cancer in which the role of chemotherapy and radiotherapy has been well established in limited-stage disease. We retrospectively reviewed a series of limited-stage small cell lung cancers treated with chemotherapy and thoracic and brain radiotherapy. A total of 124 patients affected by limited-stage small cell lung cancer has been treated over 10 years in our Institute. Fifty-three patients (42.8%) had concomitant radio-chemotherapy treatment and 71 patients (57.2%) a sequential treatment. Eighty-eight patients (70.9%) underwent an association of a platinum-derived drug (cisplatinum or carboplatinum) and etoposide. Prophylactic cranial irradiation was planned in all patients with histologically proven complete response to primary radio-chemotherapy. With a mean follow-up of 2.2 years, complete response was obtained in 50.8% of cases. We found a significant difference between different radio-chemotherapy association approaches (P = 0.007): percentages of overall survival were respectively 10.0%, 12.9% and 5.6% in early, late concomitant and sequential radio-chemotherapy timing. Cranial prophylaxis did not seem to influence overall survival (P = 0.21) or disease-free survival for local relapse (P = 0.34). Concomitant radio-chemotherapy is the best approach according to our experience. Our results show a benefit of prophylactic cranial irradiation in distant metastasis-free survival.

Two stage algorithm vs commonly used approaches for the suspect screening of complex environmental samples analyzed via liquid chromatography high resolution time of flight mass spectroscopy: A test study.

PubMed

Samanipour, Saer; Baz-Lomba, Jose A; Alygizakis, Nikiforos A; Reid, Malcolm J; Thomaidis, Nikolaos S; Thomas, Kevin V

2017-06-09

LC-HR-QTOF-MS recently has become a commonly used approach for the analysis of complex samples. However, identification of small organic molecules in complex samples with the highest level of confidence is a challenging task. Here we report on the implementation of a two stage algorithm for LC-HR-QTOF-MS datasets. We compared the performances of the two stage algorithm, implemented via NIVA_MZ_Analyzer™, with two commonly used approaches (i.e. feature detection and XIC peak picking, implemented via UNIFI by Waters and TASQ by Bruker, respectively) for the suspect analysis of four influent wastewater samples. We first evaluated the cross platform compatibility of LC-HR-QTOF-MS datasets generated via instruments from two different manufacturers (i.e. Waters and Bruker). Our data showed that with an appropriate spectral weighting function the spectra recorded by the two tested instruments are comparable for our analytes. As a consequence, we were able to perform full spectral comparison between the data generated via the two studied instruments. Four extracts of wastewater influent were analyzed for 89 analytes, thus 356 detection cases. The analytes were divided into 158 detection cases of artificial suspect analytes (i.e. verified by target analysis) and 198 true suspects. The two stage algorithm resulted in a zero rate of false positive detection, based on the artificial suspect analytes while producing a rate of false negative detection of 0.12. For the conventional approaches, the rates of false positive detection varied between 0.06 for UNIFI and 0.15 for TASQ. The rates of false negative detection for these methods ranged between 0.07 for TASQ and 0.09 for UNIFI. The effect of background signal complexity on the two stage algorithm was evaluated through the generation of a synthetic signal. We further discuss the boundaries of applicability of the two stage algorithm. The importance of background knowledge and experience in evaluating the reliability of results during the suspect screening was evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential Multiplex Analyte Capturing for Phosphoprotein Profiling*

PubMed Central

Poetz, Oliver; Henzler, Tanja; Hartmann, Michael; Kazmaier, Cornelia; Templin, Markus F.; Herget, Thomas; Joos, Thomas O.

2010-01-01

Microarray-based sandwich immunoassays can simultaneously detect dozens of proteins. However, their use in quantifying large numbers of proteins is hampered by cross-reactivity and incompatibilities caused by the immunoassays themselves. Sequential multiplex analyte capturing addresses these problems by repeatedly probing the same sample with different sets of antibody-coated, magnetic suspension bead arrays. As a miniaturized immunoassay format, suspension bead array-based assays fulfill the criteria of the ambient analyte theory, and our experiments reveal that the analyte concentrations are not significantly changed. The value of sequential multiplex analyte capturing was demonstrated by probing tumor cell line lysates for the abundance of seven different receptor tyrosine kinases and their degree of phosphorylation and by measuring the complex phosphorylation pattern of the epidermal growth factor receptor in the same sample from the same cavity. PMID:20682761

Stage Structure of Moral Development: A Comparison of Alternative Models.

ERIC Educational Resources Information Center

Hau, Kit-Tai

This study evaluated the stage structure of several quasi-simplex and non-simplex models of moral development in two domains of moral development in a British and a Chinese sample. Analyses were based on data reported by Sachs (1992): the Chinese sample consisted of 1,005 students from grade 9 to post-college, and the British sample consisted of…

THE PARADOX OF SIGN LANGUAGE MORPHOLOGY

PubMed Central

Aronoff, Mark; Meir, Irit; Sandler, Wendy

2011-01-01

Sign languages have two strikingly different kinds of morphological structure: sequential and simultaneous. The simultaneous morphology of two unrelated sign languages, American and Israeli Sign Language, is very similar and is largely inflectional, while what little sequential morphology we have found differs significantly and is derivational. We show that at least two pervasive types of inflectional morphology, verb agreement and classifier constructions, are iconically grounded in spatiotemporal cognition, while the sequential patterns can be traced to normal historical development. We attribute the paucity of sequential morphology in sign languages to their youth. This research both brings sign languages much closer to spoken languages in their morphological structure and shows how the medium of communication contributes to the structure of languages.* PMID:22223926

Two-Stage Processing of Aesthetic Information in the Human Brain Revealed by Neural Adaptation Paradigm.

PubMed

Iwasaki, Miho; Noguchi, Yasuki; Kakigi, Ryusuke

2018-06-07

Some researchers in aesthetics assume visual features related to aesthetic perception (e.g. golden ratio and symmetry) commonly embedded in masterpieces. If this is true, an intriguing hypothesis is that the human brain has neural circuitry specialized for the processing of visual beauty. We presently tested this hypothesis by combining a neuroimaging technique with the repetition suppression (RS) paradigm. Subjects (non-experts in art) viewed two images of sculptures sequentially presented. Some sculptures obeyed the golden ratio (canonical images), while the golden proportion were impaired in other sculptures (deformed images). We found that the occipito-temporal cortex in the right hemisphere showed the RS when a canonical sculpture (e.g. Venus de Milo) was repeatedly presented, but not when its deformed version was repeated. Furthermore, the right parietal cortex showed the RS to the canonical proportion even when two sculptures had different identities (e.g. Venus de Milo as the first stimulus and David di Michelangelo as the second), indicating that this region encodes the golden ratio as an abstract rule shared by different sculptures. Those results suggest two separate stages of neural processing for aesthetic information (one in the occipito-temporal and another in the parietal regions) that are hierarchically arranged in the human brain.

Sperm removal during copulation confirmed in the oldest extant damselfly, Hemiphlebia mirabilis

PubMed Central

2016-01-01

Postcopulatory sexual selection may favour mechanisms to reduce sperm competition, like physical sperm removal by males. To investigate the origin of sperm removal, I studied the reproductive behaviour and mechanisms of sperm competition in the only living member of the oldest damselfly family, Hemiphlebia mirabilis, one species that was considered extinct in the 1980s. This species displays scramble competition behaviour. Males search for females with short flights and both sexes exhibit a conspicuous “abdominal flicking”. This behaviour is used by males during an elaborate precopulatory courtship, unique among Odonata. Females use a similar display to reject male attempts to form tandem, but eventually signal receptivity by a particular body position. Males immobilise females during courtship using their legs, which, contrarily to other damselflies, never autotomise. Copulation is short (range 4.1–18.7 min), and occurs in two sequential stages. In the first stage, males remove part of the stored sperm, and inseminate during the second stage, at the end of mating. The male genital ligula matches the size and form of female genitalia, and ends by two horns covered by back-oriented spines. The volume of sperm in females before copulation was 2.7 times larger than the volume stored in females whose copulation was interrupted at the end of stage I, indicative of a significant sperm removal. These results point out that sperm removal is an old character in the evolution of odonates, possibly dating back to the Permian. PMID:27257552

Robust multiperson detection and tracking for mobile service and social robots.

PubMed

Li, Liyuan; Yan, Shuicheng; Yu, Xinguo; Tan, Yeow Kee; Li, Haizhou

2012-10-01

This paper proposes an efficient system which integrates multiple vision models for robust multiperson detection and tracking for mobile service and social robots in public environments. The core technique is a novel maximum likelihood (ML)-based algorithm which combines the multimodel detections in mean-shift tracking. First, a likelihood probability which integrates detections and similarity to local appearance is defined. Then, an expectation-maximization (EM)-like mean-shift algorithm is derived under the ML framework. In each iteration, the E-step estimates the associations to the detections, and the M-step locates the new position according to the ML criterion. To be robust to the complex crowded scenarios for multiperson tracking, an improved sequential strategy to perform the mean-shift tracking is proposed. Under this strategy, human objects are tracked sequentially according to their priority order. To balance the efficiency and robustness for real-time performance, at each stage, the first two objects from the list of the priority order are tested, and the one with the higher score is selected. The proposed method has been successfully implemented on real-world service and social robots. The vision system integrates stereo-based and histograms-of-oriented-gradients-based human detections, occlusion reasoning, and sequential mean-shift tracking. Various examples to show the advantages and robustness of the proposed system for multiperson tracking from mobile robots are presented. Quantitative evaluations on the performance of multiperson tracking are also performed. Experimental results indicate that significant improvements have been achieved by using the proposed method.

Determination of the mode of occurrence of As, Cr, and Hg in three Chinese coal samples by sequential acid leaching

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

Wang, B.; Li, W.; Wang, G.

2007-07-01

Sequential acid leaching was used to leach minerals and the trace elements they contain. One-step leaching uses concentrated nitric acid as solvent, while three-step leaching uses 5M hydrochloric acid, concentrated hydrofluoric acid, and concentrated hydrochloric acid as solvents. The sequential acid leaching by three-and one-step leach was also examined. The results showed that one-step leaching could leach over 80% of arsenic from coal samples, and also could leach mercury to a certain degree. During one-step leaching, little chromium is removed, but it is available to leach by three-step leaching; and during the sequential acid leaching by three and one-step leaching,more » almost 98% ash is leached. The result of acid leaching could also give detailed information on mode of occurrence of As, Cr, and Hg, which could be classified into: silicate association, pyrite association, organic association, and carbonates and sulfates association. Over half of chromium in the three coals is associated with organic matters and the rest is associated with silicates. The mode of occurrence of arsenic and mercury is mainly associated with different mineral matters depending on the coal samples studied.« less

Inverse sequential detection of parameter changes in developing time series

NASA Technical Reports Server (NTRS)

Radok, Uwe; Brown, Timothy J.

1992-01-01

Progressive values of two probabilities are obtained for parameter estimates derived from an existing set of values and from the same set enlarged by one or more new values, respectively. One probability is that of erroneously preferring the second of these estimates for the existing data ('type 1 error'), while the second probability is that of erroneously accepting their estimates for the enlarged test ('type 2 error'). A more stable combined 'no change' probability which always falls between 0.5 and 0 is derived from the (logarithmic) width of the uncertainty region of an equivalent 'inverted' sequential probability ratio test (SPRT, Wald 1945) in which the error probabilities are calculated rather than prescribed. A parameter change is indicated when the compound probability undergoes a progressive decrease. The test is explicitly formulated and exemplified for Gaussian samples.

Proton nuclear magnetic resonance studies on the variant-3 neurotoxin from Centruroides sculpturatus Ewing: Sequential assignment of resonances

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

Nettesheim, D.G.; Klevit, R.E.; Drobny, G.

1989-02-21

The authors report the sequential assignment of resonances to specific residues in the proton nuclear magnetic resonance spectrum of the variant-3 neurotoxin from the scorpion Centruroides sculpturatus Ewing (range southwestern U.S.A.). A combination of two-dimensional NMR experiments such as 2D-COSY, 2D-NOESY, and single- and double-RELAY coherence transfer spectroscopy has been employed on samples of the protein dissolved in D{sub 2}O and in H{sub 2}O for assignment purposes. These studies provide a basis for the determination of the solution-phase conformation of this protein and for undertaking detailed structure-function studies of these neurotoxins that modulate the flow of sodium current by bindingmore » to the sodium channels of excitable membranes.« less

The Orientation of Gastric Biopsy Samples Improves the Inter-observer Agreement of the OLGA Staging System.

PubMed

Cotruta, Bogdan; Gheorghe, Cristian; Iacob, Razvan; Dumbrava, Mona; Radu, Cristina; Bancila, Ion; Becheanu, Gabriel

2017-12-01

Evaluation of severity and extension of gastric atrophy and intestinal metaplasia is recommended to identify subjects with a high risk for gastric cancer. The inter-observer agreement for the assessment of gastric atrophy is reported to be low. The aim of the study was to evaluate the inter-observer agreement for the assessment of severity and extension of gastric atrophy using oriented and unoriented gastric biopsy samples. Furthermore, the quality of biopsy specimens in oriented and unoriented samples was analyzed. A total of 35 subjects with dyspeptic symptoms addressed for gastrointestinal endoscopy that agreed to enter the study were prospectively enrolled. The OLGA/OLGIM gastric biopsies protocol was used. From each subject two sets of biopsies were obtained (four from the antrum, two oriented and two unoriented, two from the gastric incisure, one oriented and one unoriented, four from the gastric body, two oriented and two unoriented). The orientation of the biopsy samples was completed using nitrocellulose filters (Endokit®, BioOptica, Milan, Italy). The samples were blindly examined by two experienced pathologists. Inter-observer agreement was evaluated using kappa statistic for inter-rater agreement. The quality of histopathology specimens taking into account the identification of lamina propria was analyzed in oriented vs. unoriented samples. The samples with detectable lamina propria mucosae were defined as good quality specimens. Categorical data was analyzed using chi-square test and a two-sided p value <0.05 was considered statistically significant. A total of 350 biopsy samples were analyzed (175 oriented / 175 unoriented). The kappa index values for oriented/unoriented OLGA 0/I/II/III and IV stages have been 0.62/0.13, 0.70/0.20, 0.61/0.06, 0.62/0.46, and 0.77/0.50, respectively. For OLGIM 0/I/II/III stages the kappa index values for oriented/unoriented samples were 0.83/0.83, 0.88/0.89, 0.70/0.88 and 0.83/1, respectively. No case of OLGIM IV stage was found in the present case series. Good quality histopathology specimens were described in 95.43% of the oriented biopsy samples, and in 89.14% of the unoriented biopsy samples, respectively (p=0.0275). The orientation of gastric biopsies specimens improves the inter-observer agreement for the assessment of gastric atrophy.

Monitoring lipase/esterase activity by stopped flow in a sequential injection analysis system using p-nitrophenyl butyrate.

PubMed

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J

2015-01-27

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05-1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed.

Monitoring Lipase/Esterase Activity by Stopped Flow in a Sequential Injection Analysis System Using p-Nitrophenyl Butyrate

PubMed Central

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J.

2015-01-01

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05–1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed. PMID:25633600

Electron Microscopy Imaging of Zinc Soaps Nucleation in Oil Paint.

PubMed

Hermans, Joen; Osmond, Gillian; van Loon, Annelies; Iedema, Piet; Chapman, Robyn; Drennan, John; Jack, Kevin; Rasch, Ronald; Morgan, Garry; Zhang, Zhi; Monteiro, Michael; Keune, Katrien

2018-06-04

Using the recently developed techniques of electron tomography, we have explored the first stages of disfiguring formation of zinc soaps in modern oil paintings. The formation of complexes of zinc ions with fatty acids in paint layers is a major threat to the stability and appearance of many late 19th and early 20th century oil paintings. Moreover, the occurrence of zinc soaps in oil paintings leading to defects is disturbingly common, but the chemical reactions and migration mechanisms leading to large zinc soap aggregates or zones remain poorly understood. State-of-the-art scanning (SEM) and transmission (TEM) electron microscopy techniques, primarily developed for biological specimens, have enabled us to visualize the earliest stages of crystalline zinc soap growth in a reconstructed zinc white (ZnO) oil paint sample. In situ sectioning techniques and sequential imaging within the SEM allowed three-dimensional tomographic reconstruction of sample morphology. Improvements in the detection and discrimination of backscattered electrons enabled us to identify local precipitation processes with small atomic number contrast. The SEM images were correlated to low-dose and high-sensitivity TEM images, with high-resolution tomography providing unprecedented insight into the structure of nucleating zinc soaps at the molecular level. The correlative approach applied here to study phase separation, and crystallization processes specific to a problem in art conservation creates possibilities for visualization of phase formation in a wide range of soft materials.

Face identification with frequency domain matched filtering in mobile environments

NASA Astrophysics Data System (ADS)

Lee, Dong-Su; Woo, Yong-Hyun; Yeom, Seokwon; Kim, Shin-Hwan

2012-06-01

Face identification at a distance is very challenging since captured images are often degraded by blur and noise. Furthermore, the computational resources and memory are often limited in the mobile environments. Thus, it is very challenging to develop a real-time face identification system on the mobile device. This paper discusses face identification based on frequency domain matched filtering in the mobile environments. Face identification is performed by the linear or phase-only matched filter and sequential verification stages. The candidate window regions are decided by the major peaks of the linear or phase-only matched filtering outputs. The sequential stages comprise a skin-color test and an edge mask filtering test, which verify color and shape information of the candidate regions in order to remove false alarms. All algorithms are built on the mobile device using Android platform. The preliminary results show that face identification of East Asian people can be performed successfully in the mobile environments.

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

Beeston, Michael Philip; University of Exeter in Cornwall; Tuen van Elteren, Johannes

A methodology is presented to study the physico-chemical processes in old tailings ponds using an array of analytical-physical chemistry approaches. A case study was conducted on the sorption/desorption behaviour of arsenic in tailings pond 2406, at the King Edward Mine (KEM) in Cornwall, UK. The tailings pond was in operation from approximately 1907 to 1921. The methodology involves two principal stages: (1) sequential extraction followed by subsequent arsenic species determination to characterise the material with regards to the association of arsenic with soil phases and identification of As (III/V) in the easily accessible soil phase; (2) batch contacting/equilibrating the tailingsmore » pond material with As(III/V), followed by a similar procedure as in stage 1 to establish the material's As(III/V) phase distribution kinetics/thermodynamics. By extrapolating the data from present day samples we infer past and future elemental mobility. From this study it is concluded that adsorption and desorption from tailings material is a rapid process for the most unstable soil phases (non-specific and specific) and a slow process for the more stable phases (poorly crystalline and well crystalline). The hypothetical application of this conclusion to the tailings from dam 2406 is that, during the initial phases of the dam's creation (ca. 100 years ago), when arsenic was both in solution and bound to mineralogical components, arsenic must have dispersed into the environment as a result of slow As(V) adsorption/phase distribution processes. Aging of the tailings material sees the movement of the arsenic to the more stable soil phases, producing a situation that is seen at present day.« less

Effect of aerobic pre-treatment on hydrogen and methane production in a two-stage anaerobic digestion process using food waste with different compositions.

PubMed

Rafieenia, Razieh; Girotto, Francesca; Peng, Wei; Cossu, Raffaello; Pivato, Alberto; Raga, Roberto; Lavagnolo, Maria Cristina

2017-01-01

Aerobic pre-treatment was applied prior to two-stage anaerobic digestion process. Three different food wastes samples, namely carbohydrate rich, protein rich and lipid rich, were prepared as substrates. Effect of aerobic pre-treatment on hydrogen and methane production was studied. Pre-aeration of substrates showed no positive impact on hydrogen production in the first stage. All three categories of pre-aerated food wastes produced less hydrogen compared to samples without pre-aeration. In the second stage, methane production increased for aerated protein rich and carbohydrate rich samples. In addition, the lag phase for carbohydrate rich substrate was shorter for aerated samples. Aerated protein rich substrate yielded the best results among substrates for methane production, with a cumulative production of approximately 351ml/gVS. With regard to non-aerated substrates, lipid rich was the best substrate for CH 4 production (263ml/gVS). Pre-aerated P substrate was the best in terms of total energy generation which amounted to 9.64kJ/gVS. This study revealed aerobic pre-treatment to be a promising option for use in achieving enhanced substrate conversion efficiencies and CH 4 production in a two-stage AD process, particularly when the substrate contains high amounts of proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a Two-Stage Mars Ascent Vehicle Using In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Paxton, Laurel; Vaughan, David

2014-01-01

Mars Sample Return (MSR) and Mars In-Situ Resource Utilization (ISRU) present two main challenges for the advancement of Mars science. MSR would demonstrate Mars lift-off capability, while ISRU would test the ability to produce fuel and oxidizer using Martian resources, a crucial step for future human missions. A two-stage Mars Ascent Vehicle (MAV) concept was developed to support sample return as well as in-situ propellant production. The MAV would be powered by a solid rocket first stage and a LOX-propane second stage. A liquid second-stage provides higher orbit insertion reliability than a solid second stage as well as a degree of complexity eventually required for manned missions. Propane in particular offers comparable performance to methane without requiring cryogenic storage. The total MAV mass would be 119.9 kg to carry an 11 kg payload to orbit. The feasibility of in-situ fuel and oxidizer production was also examined. Two potential schemes were evaluated for production capability, size and power requirements. The schemes examined utilize CO2 and water as starting blocks to produce LOX and a propane blend. The infrastructure required to fuel and launch the MAV was also explored.

Note: A wide temperature range MOKE system with annealing capability.

PubMed

Chahil, Narpinder Singh; Mankey, G J

2017-07-01

A novel sample stage integrated with a longitudinal MOKE system has been developed for wide temperature range measurements and annealing capabilities in the temperature range 65 K < T < 760 K. The sample stage incorporates a removable platen and copper block with inserted cartridge heater and two thermocouple sensors. It is supported and thermally coupled to a cold finger with two sapphire bars. The sapphire based thermal coupling enables the system to perform at higher temperatures without adversely affecting the cryostat and minimizes thermal drift in position. In this system the hysteresis loops of magnetic samples can be measured simultaneously while annealing the sample in a magnetic field.

A simple two-stage design for quantitative responses with application to a study in diabetic neuropathic pain.

PubMed

Whitehead, John; Valdés-Márquez, Elsa; Lissmats, Agneta

2009-01-01

Two-stage designs offer substantial advantages for early phase II studies. The interim analysis following the first stage allows the study to be stopped for futility, or more positively, it might lead to early progression to the trials needed for late phase II and phase III. If the study is to continue to its second stage, then there is an opportunity for a revision of the total sample size. Two-stage designs have been implemented widely in oncology studies in which there is a single treatment arm and patient responses are binary. In this paper the case of two-arm comparative studies in which responses are quantitative is considered. This setting is common in therapeutic areas other than oncology. It will be assumed that observations are normally distributed, but that there is some doubt concerning their standard deviation, motivating the need for sample size review. The work reported has been motivated by a study in diabetic neuropathic pain, and the development of the design for that trial is described in detail. Copyright 2008 John Wiley & Sons, Ltd.

Rheo-optical near-infrared (NIR) spectroscopy study of partially miscible polymer blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG)

NASA Astrophysics Data System (ADS)

Shinzawa, Hideyuki; Mizukado, Junji

2018-03-01

Tensile deformations of a partially miscible blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG) is studied by a rheo-optical characterization near-infrared (NIR) technique to probe deformation behavior during tensile deformation. Sets of NIR spectra of the polymer samples were collected by using an acousto-optic tunable filter (AOTF) NIR spectrometer coupled with a tensile testing machine as an excitation device. While deformations of the samples were readily captured as strain-dependent NIR spectra, the entire feature of the spectra was overwhelmed with the baseline fluctuation induced by the decrease in the sample thickness and subsequent change in the light scattering. Several pretreatment techniques, including multiplicative scatter collection (MSC) and null-space projection, are subjected to the NIR spectra prior to the determination of the sequential order of the spectral intensity changes by two-dimensional (2D) correlation analysis. The comparison of the MSC and null-space projection provided an interesting insight into the system, especially deformation-induced variation of light scattering observed during the tensile testing of the polymer sample. In addition, the sequential order determined with the 2D correlation spectra revealed that orientation of a specific part of PMMA chain occurs before that of the others because of the interaction between Cdbnd O group of PMMA and terminal sbnd OH group of PEG.

Creating fast flow channels in paper fluidic devices to control timing of sequential reactions.

PubMed

Jahanshahi-Anbuhi, Sana; Chavan, Puneet; Sicard, Clémence; Leung, Vincent; Hossain, S M Zakir; Pelton, Robert; Brennan, John D; Filipe, Carlos D M

2012-12-07

This paper reports the development of a method to control the flow rate of fluids within paper-based microfluidic analytical devices. We demonstrate that by simply sandwiching paper channels between two flexible films, it is possible to accelerate the flow of water through paper by over 10-fold. The dynamics of this process are such that the height of the liquid is dependent on time to the power of 1/3. This dependence was validated using three different flexible films (with markedly different contact angles) and three different fluids (water and two silicon oils with different viscosities). These covered channels provide a low-cost method for controlling the flow rate of fluid in paper channels, and can be added following printing of reagents to control fluid flow in selected fluidic channels. Using this method, we redesigned a previously published bidirectional lateral flow pesticide sensor to allow more rapid detection of pesticides while eliminating the need to run the assay in two stages. The sensor is fabricated with sol-gel entrapped reagents (indoxyl acetate in a substrate zone and acetylcholinesterase, AChE, in a sensing zone) present in an uncovered "slow" flow channel, with a second, covered "fast" channel used to transport pesticide samples to the sensing region through a simple paper-flap valve. In this manner, pesticides reach the sensing region first to allow preincubation, followed by delivery of the substrate to generate a colorimetric signal. This format results in a uni-directional device that detects the presence of pesticides two times faster than the original bidirectional sensors.

The dynamics of herpesvirus reactivations during and after severe drug eruptions: their relation to the clinical phenotype and therapeutic outcome.

PubMed

Ishida, T; Kano, Y; Mizukawa, Y; Shiohara, T

2014-06-01

Drug-induced hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms (DIHS/DRESS) and Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) represent contrasting poles of severe drug eruptions, and sequential reactivations of several herpesviruses have exclusively been demonstrated in the former. No previous studies, however, were extended beyond the acute stage. We sought to investigate whether herpesvirus reactivations could also be observed in SJS/TEN and beyond the acute stage of both diseases. Patients with SJS (n = 16), SJS/TEN overlap (n = 2), TEN (n = 10), and DIHS/DRESS (n = 34) were enrolled. We performed a retrospective analysis of Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and cytomegalovirus (CMV) DNA loads sequentially determined by real-time polymerase chain reaction during a 2-year period after onset. Persistently increased EBV loads were detected in SJS during the acute stage and long after resolution, but not in others. In contrast, high HHV-6 loads were exclusively detected in DIHS/DRESS during the acute stage. The dynamics of herpesvirus reactivation varied in DIHS/DRESS according to the use of systemic corticosteroids: While EBV loads were higher in patients not receiving systemic corticosteroids, CMV and HHV-6 loads were higher in those receiving them. Distinct patterns of herpesvirus reactivation according to the pathological phenotype and to the use of systemic corticosteroids were observed during the acute stage and follow-up period, which may contribute, at least in part, to the difference in the clinical manifestations and long-term outcomes. Systemic corticosteroids during the acute stage may improve the outcomes in DIHS/DRESS. © 2014 The Authors. Allergy Published by John Wiley & Sons Ltd.

Kullback-Leibler information function and the sequential selection of experiments to discriminate among several linear models

NASA Technical Reports Server (NTRS)

Sidik, S. M.

1972-01-01

The error variance of the process prior multivariate normal distributions of the parameters of the models are assumed to be specified, prior probabilities of the models being correct. A rule for termination of sampling is proposed. Upon termination, the model with the largest posterior probability is chosen as correct. If sampling is not terminated, posterior probabilities of the models and posterior distributions of the parameters are computed. An experiment was chosen to maximize the expected Kullback-Leibler information function. Monte Carlo simulation experiments were performed to investigate large and small sample behavior of the sequential adaptive procedure.

Cell wall invertase as a regulator in determining sequential development of endosperm and embryo through glucose signaling early in seed development.

PubMed

Wang, Lu; Liao, Shengjin; Ruan, Yong-Ling

2013-01-01

Seed development depends on coordination among embryo, endosperm and seed coat. Endosperm undergoes nuclear division soon after fertilization, whereas embryo remains quiescent for a while. Such a developmental sequence is of great importance for proper seed development. However, the underlying mechanism remains unclear. Recent results on the cellular domain- and stage-specific expression of invertase genes in cotton and Arabidopsis revealed that cell wall invertase may positively and specifically regulate nuclear division of endosperm after fertilization, thereby playing a role in determining the sequential development of endosperm and embryo, probably through glucose signaling.

A Risk-Constrained Multi-Stage Decision Making Approach to the Architectural Analysis of Mars Missions

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Pavone, Marco; Balaram, J. (Bob)

2012-01-01

This paper presents a novel risk-constrained multi-stage decision making approach to the architectural analysis of planetary rover missions. In particular, focusing on a 2018 Mars rover concept, which was considered as part of a potential Mars Sample Return campaign, we model the entry, descent, and landing (EDL) phase and the rover traverse phase as four sequential decision-making stages. The problem is to find a sequence of divert and driving maneuvers so that the rover drive is minimized and the probability of a mission failure (e.g., due to a failed landing) is below a user specified bound. By solving this problem for several different values of the model parameters (e.g., divert authority), this approach enables rigorous, accurate and systematic trade-offs for the EDL system vs. the mobility system, and, more in general, cross-domain trade-offs for the different phases of a space mission. The overall optimization problem can be seen as a chance-constrained dynamic programming problem, with the additional complexity that 1) in some stages the disturbances do not have any probabilistic characterization, and 2) the state space is extremely large (i.e, hundreds of millions of states for trade-offs with high-resolution Martian maps). To this purpose, we solve the problem by performing an unconventional combination of average and minimax cost analysis and by leveraging high efficient computation tools from the image processing community. Preliminary trade-off results are presented.

Multidrug resistance among new tuberculosis cases: detecting local variation through lot quality-assurance sampling.

PubMed

Hedt, Bethany Lynn; van Leth, Frank; Zignol, Matteo; Cobelens, Frank; van Gemert, Wayne; Nhung, Nguyen Viet; Lyepshina, Svitlana; Egwaga, Saidi; Cohen, Ted

2012-03-01

Current methodology for multidrug-resistant tuberculosis (MDR TB) surveys endorsed by the World Health Organization provides estimates of MDR TB prevalence among new cases at the national level. On the aggregate, local variation in the burden of MDR TB may be masked. This paper investigates the utility of applying lot quality-assurance sampling to identify geographic heterogeneity in the proportion of new cases with multidrug resistance. We simulated the performance of lot quality-assurance sampling by applying these classification-based approaches to data collected in the most recent TB drug-resistance surveys in Ukraine, Vietnam, and Tanzania. We explored 3 classification systems- two-way static, three-way static, and three-way truncated sequential sampling-at 2 sets of thresholds: low MDR TB = 2%, high MDR TB = 10%, and low MDR TB = 5%, high MDR TB = 20%. The lot quality-assurance sampling systems identified local variability in the prevalence of multidrug resistance in both high-resistance (Ukraine) and low-resistance settings (Vietnam). In Tanzania, prevalence was uniformly low, and the lot quality-assurance sampling approach did not reveal variability. The three-way classification systems provide additional information, but sample sizes may not be obtainable in some settings. New rapid drug-sensitivity testing methods may allow truncated sequential sampling designs and early stopping within static designs, producing even greater efficiency gains. Lot quality-assurance sampling study designs may offer an efficient approach for collecting critical information on local variability in the burden of multidrug-resistant TB. Before this methodology is adopted, programs must determine appropriate classification thresholds, the most useful classification system, and appropriate weighting if unbiased national estimates are also desired.

Preservation Effect of Two-Stage Cinnamon Bark (Cinnamomum Burmanii) Oleoresin Microcapsules On Vacuum-Packed Ground Beef During Refrigerated Storage

NASA Astrophysics Data System (ADS)

Irfiana, D.; Utami, R.; Khasanah, L. U.; Manuhara, G. J.

2017-04-01

The purpose of this study was to determine the effect of two stage cinnamon bark oleoresin microcapsules (0%, 0.5% and 1%) on the TPC (Total Plate Count), TBA (thiobarbituric acid), pH, and RGB color (Red, Green, and Blue) of vacuum-packed ground beef during refrigerated storage (at 0, 4, 8, 12, and 16 days). This study showed that the addition of two stage cinnamon bark oleoresin microcapsules affected the quality of vacuum-packed ground beef during 16 days of refrigerated storage. The results showed that the TPC value of the vacuum-packed ground beef sample with the addition 0.5% and 1% microcapsules was lower than the value of control sample. The TPC value of the control sample, sample with additional 0.5% and 1% microcapsules were 5.94; 5.46; and 5.16 log CFU/g respectively. The TBA value of vacuum-packed ground beef were 0.055; 0.041; and 0.044 mg malonaldehyde/kg, resepectively on the 16th day of storage. The addition of two-stage cinnamon bark oleoresin microcapsules could inhibit the growth of microbia and decrease the oxidation process of vacuum-packed ground beef. Moreover, the change of vacuum-packed ground beef pH and RGB color with the addition 0.5% and 1% microcapsules were less than those of the control sample. The addition of 1% microcapsules showed the best effect in preserving the vacuum-packed ground beef.

Adherence to AIOM (Italian Association of Medical Oncology) lung cancer guidelines in Italian clinical practice: Results from the RIGHT-3 (research for the identification of the most effective and highly accepted clinical guidelines for cancer treatment) study.

PubMed

Barni, Sandro; Maiello, Evaristo; Di Maio, Massimo; Ardizzoni, Andrea; Cappuzzo, Federico; Maranzano, Ernesto; Novello, Silvia; Bennati, Chiara; Ori, Alessandra; Rizzoli, Sara; Crinò, Lucio

2015-11-01

Clinical practice guidelines represent a key tool to improve quality and reduce variability of cancer care. In 2004, Italian Association of Medical Oncology (AIOM) launched the RIGHT (research for the identification of the most effective and highly accepted clinical guidelines for cancer treatment) program. The third step, RIGHT-3, evaluated the concordance between AIOM lung cancer guidelines and Italian clinical practice. RIGHT-3 was a retrospective observational study, conducted in 53 Italian centers treating lung cancer. Sampling from AIOM database of 230 centers was stratified by presence of thoracic surgery and geographic distribution. To describe the adherence to AIOM guidelines (2009 edition), 11 indicators regarding diagnostic and treatment procedures were identified. Patients with non-small-cell lung cancer (NSCLC) diagnosis who had first visit in 2010 were divided into 3 groups, based on TNM stage: I-II-IIIA (5 indicators), IIIB (3 indicators) and IV (3 indicators). 708 patients were enrolled; 680 were eligible: 225 patients in stage I-II-IIIA; 156 patients in stage IIIB; 299 patients in stage IV. Cyto-histological diagnosis was available in 96%, 97%, 96% of stage I-II-IIIA, IIIB, IV respectively. Positron-emission tomography was performed in 64% of stage I-II-IIIA and 46% of stage IIIB. 88% of stage I-II patients eligible for surgery underwent lobectomy; after surgery, 61% of stage II and 57% of stage IIIA patients received adjuvant chemotherapy. Among stage IIIB patients who received combined chemo- radiotherapy, sequential approach was more common than concomitant treatment (86% vs. 14%). Among stage IV patients, 87% received platinum-based first-line treatment, and 70% received second-line. The RIGHT-3 study showed that, in 2010, adherence to Italian NSCLC guidelines was high for many indicators (including those related to treatment of stage IV patients), but lower for some diagnostic procedures. Guidelines adherence monitoring can be useful to reduce variability in cancer care. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sequential and Simultaneous Processing in Children with Learning Disabilities: An Attempted Replication.

ERIC Educational Resources Information Center

Bain, Sherry K.

1993-01-01

Analysis of Kaufman Assessment Battery for Children (K-ABC) Sequential and Simultaneous Processing scores of 94 children (ages 6-12) with learning disabilities produced factor patterns generally supportive of the traditional K-ABC Mental Processing structure with the exception of Spatial Memory. The sample exhibited relative processing strengths…

A model of cardiopulmonary bypass staged training integrating technical and non-technical skills dedicated to cardiac trainees.

PubMed

Fouilloux, V; Doguet, F; Kotsakis, A; Dubrowski, A; Berdah, S

2015-03-01

To develop a standardized simulation-based curriculum to teach medical knowledge and technical, communication and critical thinking skills necessary to initiate and wean from cardiopulmonary bypass (CPB) to junior cardiac trainees (CTs) in France. Performance on post-curricular tests was compared between CTs who participated in the new curriculum to those who did not. The simulation-based curriculum was developed by content and education experts. Simulations sequentially taught the skills necessary for initiating and weaning from CPB as well as managing crises by adding fidelity and complexity to scenarios. Nine CTs were randomly assigned to the new curriculum (n=5) or the traditional curriculum (n=4). Skills were assessed using tests of medical knowledge and technical, communication (GRS) and critical thinking (SCT) skills. A two-sample Wilcoxon rank-sum test compared average scores between the two groups. Alpha of 0.05 was set to indicate statistically significant differences. The resutls revealed that CTs in the new curriculum significantly outperformed CTs in the traditional curriculum on technical (18.2 vs 14.8, p=0.05) and communication (3.5 vs 2.2, p=0.013) skills. There was no significant difference between CTs in the new curriculum in the Script Concordance Test (16.5 vs 14.8, p=0.141) and knowledge tests (26.9 vs 24.6, p=0.14) compared to CTs in the traditional curriculum. Our new curriculum teaches communication and technical skills necessary for CPB. The results of this pilot study are encouraging and relevant. They give grounds for future research with a larger panel of trainees. Based on the current distribution of scores, a sample size of 12 CTs per group should yield significant results for all tests. © The Author(s) 2014.

Chemical and functional properties of cell wall polymers from two cherry varieties at two developmental stages.

PubMed

Basanta, María F; de Escalada Plá, Marina F; Stortz, Carlos A; Rojas, Ana M

2013-01-30

The cell wall polysaccharides of Regina and Sunburst cherry varieties at two developmental stages were extracted sequentially, and their changes in monosaccharide composition and functional properties were studied. The loosely-attached pectins presented a lower d-galacturonic acid/rhamnose ratio than ionically-bound pectins, as well as lower thickening effects of their respective 2% aqueous solution: the lowest Newtonian viscosity and shear rate dependence during the pseudoplastic phase. The main constituents of the cell wall matrix were covalently bound pectins (probably through diferulate cross-linkings), with long arabinan side chains at the RG-I cores. This pectin domain was also anchored into the XG-cellulose elastic network. Ripening occurred with a decrease in the proportion of HGs, water extractable GGM and xylogalacturonan, and with a concomitant increase in neutral sugars. Ripening was also associated with higher viscosities and thickening effects, and to larger distribution of molecular weights. The highest firmness and compactness of Regina cherry may be associated with its higher proportion of calcium-bound HGs localized in the middle lamellae of cell walls, as well as to some higher molar proportion of NS (Rha and Ara) in covalently bound pectins. These pectins showed significantly better hydration properties than hemicellulose and cellulose network. Chemical composition and functional properties of cell wall polymers were dependent on cherry variety and ripening stage, and helped explain the contrasting firmness of Regina and Sunburst varieties. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Preparation of Term Papers Based upon a Research-Process Model.

ERIC Educational Resources Information Center

Feldmann, Rodney Mansfield; Schloman, Barbara Frick

1990-01-01

Described is an alternative method of term paper preparation which provides a step-by-step sequence of assignments and provides feedback to the students at all stages in the preparation of the report. An example of this model is provided including 13 sequential assignments. (CW)

Exposure Control Using Adaptive Multi-Stage Item Bundles.

ERIC Educational Resources Information Center

Luecht, Richard M.

This paper presents a multistage adaptive testing test development paradigm that promises to handle content balancing and other test development needs, psychometric reliability concerns, and item exposure. The bundled multistage adaptive testing (BMAT) framework is a modification of the computer-adaptive sequential testing framework introduced by…

Recombinant Temporal Aberration Detection Algorithms for Enhanced Biosurveillance

PubMed Central

Murphy, Sean Patrick; Burkom, Howard

2008-01-01

Objective Broadly, this research aims to improve the outbreak detection performance and, therefore, the cost effectiveness of automated syndromic surveillance systems by building novel, recombinant temporal aberration detection algorithms from components of previously developed detectors. Methods This study decomposes existing temporal aberration detection algorithms into two sequential stages and investigates the individual impact of each stage on outbreak detection performance. The data forecasting stage (Stage 1) generates predictions of time series values a certain number of time steps in the future based on historical data. The anomaly measure stage (Stage 2) compares features of this prediction to corresponding features of the actual time series to compute a statistical anomaly measure. A Monte Carlo simulation procedure is then used to examine the recombinant algorithms’ ability to detect synthetic aberrations injected into authentic syndromic time series. Results New methods obtained with procedural components of published, sometimes widely used, algorithms were compared to the known methods using authentic datasets with plausible stochastic injected signals. Performance improvements were found for some of the recombinant methods, and these improvements were consistent over a range of data types, outbreak types, and outbreak sizes. For gradual outbreaks, the WEWD MovAvg7+WEWD Z-Score recombinant algorithm performed best; for sudden outbreaks, the HW+WEWD Z-Score performed best. Conclusion This decomposition was found not only to yield valuable insight into the effects of the aberration detection algorithms but also to produce novel combinations of data forecasters and anomaly measures with enhanced detection performance. PMID:17947614

Continuity of the sequential product of sequential quantum effect algebras

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

Lei, Qiang, E-mail: leiqiang@hit.edu.cn; Su, Xiaochao, E-mail: hitswh@163.com; Wu, Junde, E-mail: wjd@zju.edu.cn

In order to study quantum measurement theory, sequential product defined by A∘B = A{sup 1/2}BA{sup 1/2} for any two quantum effects A, B has been introduced. Physically motivated conditions ask the sequential product to be continuous with respect to the strong operator topology. In this paper, we study the continuity problems of the sequential product A∘B = A{sup 1/2}BA{sup 1/2} with respect to other important topologies, such as norm topology, weak operator topology, order topology, and interval topology.

Coordinated control of a space manipulator tested by means of an air bearing free floating platform

NASA Astrophysics Data System (ADS)

Sabatini, Marco; Gasbarri, Paolo; Palmerini, Giovanni B.

2017-10-01

A typical approach studied for the guidance of next generation space manipulators (satellites with robotic arms aimed at autonomously performing on-orbit operations) is to decouple the platform and the arm maneuvers, which are supposed to happen sequentially, mainly because of safety concerns. This control is implemented in this work as a two-stage Sequential control, where a first stage calls for the motion of the platform and the second stage calls for the motion of the manipulator. A second novel strategy is proposed, considering the platform and the manipulator as a single multibody system subject to a Coordinated control, with the goal of approaching and grasping a target spacecraft. At the scope, a region that the end effector can reach by means of the arm motion with limited reactions on the platform is identified (the so called Reaction Null workspace). The Coordinated control algorithm performs a gain modulation (finalized to a balanced contribution of the platform and arm motion) as a function of the target position within this Reaction Null map. The result is a coordinated maneuver in which the end effector moves thanks to the platform motion, predominant in a first phase, and to the arm motion, predominant when the Reaction-Null workspace is reached. In this way the collision avoidance and attitude over-control issues are automatically considered, without the need of splitting the mission in independent (and overall sub-optimal) segments. The guidance and control algorithms are first simulated by means of a multibody code, and successively tested in the lab by means of a free floating platform equipped with a robotic arm, moving frictionless on a flat granite table thanks to air bearings and on-off thrusters; the results will be discussed in terms of optimality of the fuel consumption and final accuracy.

Evaluating the Validity of a Two-stage Sample in a Birth Cohort Established from Administrative Databases.

PubMed

El-Zein, Mariam; Conus, Florence; Benedetti, Andrea; Parent, Marie-Elise; Rousseau, Marie-Claude

2016-01-01

When using administrative databases for epidemiologic research, a subsample of subjects can be interviewed, eliciting information on undocumented confounders. This article presents a thorough investigation of the validity of a two-stage sample encompassing an assessment of nonparticipation and quantification of the extent of bias. Established through record linkage of administrative databases, the Québec Birth Cohort on Immunity and Health (n = 81,496) aims to study the association between Bacillus Calmette-Guérin vaccination and asthma. Among 76,623 subjects classified in four Bacillus Calmette-Guérin-asthma strata, a two-stage sampling strategy with a balanced design was used to randomly select individuals for interviews. We compared stratum-specific sociodemographic characteristics and healthcare utilization of stage 2 participants (n = 1,643) with those of eligible nonparticipants (n = 74,980) and nonrespondents (n = 3,157). We used logistic regression to determine whether participation varied across strata according to these characteristics. The effect of nonparticipation was described by the relative odds ratio (ROR = ORparticipants/ORsource population) for the association between sociodemographic characteristics and asthma. Parental age at childbirth, area of residence, family income, and healthcare utilization were comparable between groups. Participants were slightly more likely to be women and have a mother born in Québec. Participation did not vary across strata by sex, parental birthplace, or material and social deprivation. Estimates were not biased by nonparticipation; most RORs were below one and bias never exceeded 20%. Our analyses evaluate and provide a detailed demonstration of the validity of a two-stage sample for researchers assembling similar research infrastructures.

[Clinical patterns and stages of multiple organ failure in the elderly].

PubMed

Wang, S

1990-05-01

Multiple organ failure in the elderly (MOFE) is a new clinical syndrome different from multiple organ failure (MOF) caused by trauma occurring most often in young and mid-aged persons. The authors retrospectively analysed 158 cases of MOFE hospitalized in the past 12 years and commented on its definition, diagnostic criteria, clinical patterns and stages. The suggested definition of MOFE is the sequential 2 or more organs failure within a short period in the elderly patients (greater than or equal to 60 years old) with multiple organ chronic diseases in the presence of aging of organs and age-related malfunction. The most common precipitating factors are pulmonary infections and acute attack of chronic cardiac, cerebral and renal diseases. The interval between failures of various organs is mostly less than 10 days and seldom longer than 1 month. MOFE has 3 different patterns: rapid pattern with single phase; delayed pattern with two phases and recurrent pattern with multiple phase. In the last pattern the patients suffer from multiple attacks of multiple organ failure. It is only seen in MOFE, but not in MOF. The presentation of this particular pattern is related to the following facts: (1). A few organs or only the heart and lungs are involved. (2) Kidney, brain and hemopoietic system etc. usually with poor prognosis are not involved. (3) The age of patients are relatively younger. (4) More resuscitation experiences have been accumulated and better resuscitation measures are available. The clinical course of MOFE can be divided into 3 stages: prefailure stage (stage I), failure compensations stage (stage II) and decompensation stage (stage III).(ABSTRACT TRUNCATED AT 250 WORDS)

Novel clinical staging for patients with end-stage gastrointestinal carcinoma.

PubMed

Yasuda, Naokuni; Nakashima, Osamu; Ohnaka, Toru; Kamisaka, Koji; Tsunoda, Akira; Kusano, Mitsuo

2006-01-01

We created a new clinical staging system for end-stage gastrointestinal (GI) carcinoma to clarify the therapeutic goals for these patients. Data were obtained from a retrospective review of medical charts. Based on daily clinical observation of 144 patients with end-stage GI carcinoma, we classified the terminal stages as A, B, C, and D. The mean durations of terminal stages A, B, C, and D were 19, 16.6, 6.6, and 1.8 days, respectively, in patients with end-stage gastric cancer and 28.5, 9.1, 5.4, and 1.9 days, respectively, in patients with colorectal cancer. Moreover, 88.0% of patients with gastric carcinoma and 82.6% of patients with colorectal carcinoma passed through terminal stages A, B, C, and D sequentially. The patients in terminal stage B experienced temporary relief of symptoms, but those in terminal stage C did not (P < 0.05). These terminal stages can easily be judged by clinical observation and may be an effective new tool with which to manage patients with end-stage GI carcinoma and their families.

The effectiveness of municipal sewage sludge application on the stabilization of Pb, Zn, and Cd in a soil contaminated from mining activities.

PubMed

Xenidis, A; Stouraiti, C; Moirou, A

2001-01-01

The effectiveness of municipal sewage sludge for the stabilisation of Pb, Zn and Cd in a heavily contaminated soil was evaluated by performing pot experiments on soil-sludge mixtures. The soil sample originated from the Montevecchio mining district, Sardinia, Italy, and presented high Pb, Zn and Cd content, as well as US EPA TCLP solubility values for Pb and Cd, which exceeded the respective regulatory limits. Sewage sludge application increased the soil pH. Stabilisation experiments showed that 10% w/w sewage sludge addition effectively reduced Pb and Cd solubilities below the TCLP regulatory limits. At the same addition rate, the EDTA extractable fraction of Pb, Zn, Cd in the treated soil was reduced by 12, 47 and 50% respectively compared with the untreated sample. The five-stage sequential extraction procedure applied on the untreated and treated soil samples, showed a remarkable shift of the metals towards more stable forms. The reducible fractions of Zn and Cd and the residual fraction of Pb were increased by 12, 20 and 18% respectively, while a corresponding decrease in the mobile fractions (exchangeable and carbonate) occurred which accounted for 14, 23 and 25% respectively.

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.

Key considerations for the experimental training and evaluation of cancer odour detection dogs: lessons learnt from a double-blind, controlled trial of prostate cancer detection

PubMed Central

2014-01-01

Background Cancer detection using sniffer dogs is a potential technology for clinical use and research. Our study sought to determine whether dogs could be trained to discriminate the odour of urine from men with prostate cancer from controls, using rigorous testing procedures and well-defined samples from a major research hospital. Methods We attempted to train ten dogs by initially rewarding them for finding and indicating individual prostate cancer urine samples (Stage 1). If dogs were successful in Stage 1, we then attempted to train them to discriminate prostate cancer samples from controls (Stage 2). The number of samples used to train each dog varied depending on their individual progress. Overall, 50 unique prostate cancer and 67 controls were collected and used during training. Dogs that passed Stage 2 were tested for their ability to discriminate 15 (Test 1) or 16 (Tests 2 and 3) unfamiliar prostate cancer samples from 45 (Test 1) or 48 (Tests 2 and 3) unfamiliar controls under double-blind conditions. Results Three dogs reached training Stage 2 and two of these learnt to discriminate potentially familiar prostate cancer samples from controls. However, during double-blind tests using new samples the two dogs did not indicate prostate cancer samples more frequently than expected by chance (Dog A sensitivity 0.13, specificity 0.71, Dog B sensitivity 0.25, specificity 0.75). The other dogs did not progress past Stage 1 as they did not have optimal temperaments for the sensitive odour discrimination training. Conclusions Although two dogs appeared to have learnt to select prostate cancer samples during training, they did not generalise on a prostate cancer odour during robust double-blind tests involving new samples. Our study illustrates that these rigorous tests are vital to avoid drawing misleading conclusions about the abilities of dogs to indicate certain odours. Dogs may memorise the individual odours of large numbers of training samples rather than generalise on a common odour. The results do not exclude the possibility that dogs could be trained to detect prostate cancer. We recommend that canine olfactory memory is carefully considered in all future studies and rigorous double-blind methods used to avoid confounding effects. PMID:24575737

Combination free electron and gaseous laser

DOEpatents

Brau, Charles A.; Rockwood, Stephen D.; Stein, William E.

1980-01-01

A multiple laser having one or more gaseous laser stages and one or more free electron stages. Each of the free electron laser stages is sequentially pumped by a microwave linear accelerator. Subsequently, the electron beam is directed through a gaseous laser, in the preferred embodiment, and in an alternative embodiment, through a microwave accelerator to lower the energy level of the electron beam to pump one or more gaseous lasers. The combination laser provides high pulse repetition frequencies, on the order of 1 kHz or greater, high power capability, high efficiency, and tunability in the synchronous production of multiple beams of coherent optical radiation.

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.

Direct comparison of XAFS spectroscopy and sequential extraction for arsenic speciation in coal

USGS Publications Warehouse

Huggins, Frank E.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.A.; Finkelman, R.B.

2000-01-01

The speciation of arsenic in an Ohio bituminous coal and a North Dakota lignite has been examined by the complementary methods of arsenic XAFS spectroscopy and sequential extraction by aqueous solutions of ammonium acetate, HCl, HF, and HNO3. In order to facilitate a more direct comparison of the two methods, the arsenic XAFS spectra were obtained from aliquots of the coal prepared after each stage of the leaching procedure. For the aliquots, approximately linear correlations (r2 > 0.98 for the Ohio coal, > 0.90 for the ND lignite) were observed between the height of the edge-step in the XAFS analysis and the concentration of arsenic measured by instrumental neutron activation analysis. Results from the leaching sequence indicate that there are two major arsenic forms present in both coals; one is removed by leaching with HCl and the other by HNO3. Whereas the XAFS spectral signatures of the arsenic leached by HCl are compatible with arsenate for both coals, the arsenic leached by HNO3 is identified as arsenic associated with pyrite for the Ohio coal and as an As3+ species for the North Dakota lignite. Minor arsenate forms persist in both coals after the final leaching with nitric acid. The arsenate forms extracted in HCl are believed to be oxidation products derived from the other major arsenic forms upon exposure of the pulverized coals to air.

Reducing noise component on medical images

NASA Astrophysics Data System (ADS)

Semenishchev, Evgeny; Voronin, Viacheslav; Dub, Vladimir; Balabaeva, Oksana

2018-04-01

Medical visualization and analysis of medical data is an actual direction. Medical images are used in microbiology, genetics, roentgenology, oncology, surgery, ophthalmology, etc. Initial data processing is a major step towards obtaining a good diagnostic result. The paper considers the approach allows an image filtering with preservation of objects borders. The algorithm proposed in this paper is based on sequential data processing. At the first stage, local areas are determined, for this purpose the method of threshold processing, as well as the classical ICI algorithm, is applied. The second stage uses a method based on based on two criteria, namely, L2 norm and the first order square difference. To preserve the boundaries of objects, we will process the transition boundary and local neighborhood the filtering algorithm with a fixed-coefficient. For example, reconstructed images of CT, x-ray, and microbiological studies are shown. The test images show the effectiveness of the proposed algorithm. This shows the applicability of analysis many medical imaging applications.

The Application of Concurrent Engineering Tools and Design Structure Matrix in Designing Tire

NASA Astrophysics Data System (ADS)

Ginting, Rosnani; Fachrozi Fitra Ramadhan, T.

2016-02-01

The development of automobile industry in Indonesia is growing rapidly. This phenomenon causes companies related to the automobile industry such as tire industry must develop products based on customers’ needs and considering the timeliness of delivering the product to the customer. It could be reached by applying strategic planning in developing an integrated concept of product development. This research was held in PT. XYZ that applied the sequential approach in designing and developing products. The need to improve in one stage of product development could occur re-designing that needs longer time in developing a new product. This research is intended to get an integrated product design concept of tire pertaining to the customer's needs using Concurrent Engineering Tools by implementing the two-phased of product development. The implementation of Concurrent Engineering approach results in applying the stage of project planning, conceptual design, and product modules. The product modules consist of four modules that using Product Architecture - Design Structure Matrix to ease the designing process of new product development.

Three-Stage Production Cost Modeling Approach for Evaluating the Benefits of Intra-Hour Scheduling between Balancing Authorities

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

Samaan, Nader A.; Milligan, Michael; Hunsaker, Matthew

This paper introduces a Production Cost Modeling (PCM) approach to evaluate the benefits of intra-hour scheduling between Balancing Authorities (BAs). The system operation is modeled in a three-stage sequential manner: day ahead (DA)-hour ahead (HA)-real time (RT). In addition to contingency reserve, each BA will need to carry out “up” and “down” load following and regulation reserve capacity requirements in the DA and HA time frames. In the real-time simulation, only contingency and regulation reserves are carried out as load following is deployed. To model current real-time operation with hourly schedules, a new constraint was introduced to force each BAmore » net exchange schedule deviation from HA schedules to be within NERC ACE limits. Case studies that investigate the benefits of moving from hourly exchange schedules between WECC BAs into 10-min exchange schedules under two different levels of wind and solar penetration (11% and 33%) are presented.« less

Three-Stage Production Cost Modeling Approach for Evaluating the Benefits of Intra-Hour Scheduling Between Balancing Authorities

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

Samaan, Nader; Milligan, Michael; Hunsaker, Matt

This paper introduces a production cost modeling approach for evaluating the benefits of intra-hour scheduling among Balancing Authorities (BAs). System operation is modeled in a three-stage sequential manner: day ahead (DA)-hour ahead (HA) real time (RT). In addition to contingency reserve, each BA will need to carry out 'up' and 'down' load following and regulation reserve capacity requirements in the DA and HA time frames. In the RT simulation, only contingency and regulation reserves are carried out as load following is deployed. To model current RT operation with hourly schedules, a new constraint was introduced to force each BA netmore » exchange schedule deviation from HA schedules to be within North American Electric Reliability Corporation (NERC) area control error (ACE) limits. Case studies that investigate the benefits of moving from hourly exchange schedules between Western Electricity Coordinating Council (WECC) BAs into 10-minute exchange schedules under two different levels of wind and solar penetration (11% and 33%) are presented.« less