Relating Complexity and Error Rates of Ontology Concepts. More Complex NCIt Concepts Have More Errors.

PubMed

Min, Hua; Zheng, Ling; Perl, Yehoshua; Halper, Michael; De Coronado, Sherri; Ochs, Christopher

2017-05-18

Ontologies are knowledge structures that lend support to many health-information systems. A study is carried out to assess the quality of ontological concepts based on a measure of their complexity. The results show a relation between complexity of concepts and error rates of concepts. A measure of lateral complexity defined as the number of exhibited role types is used to distinguish between more complex and simpler concepts. Using a framework called an area taxonomy, a kind of abstraction network that summarizes the structural organization of an ontology, concepts are divided into two groups along these lines. Various concepts from each group are then subjected to a two-phase QA analysis to uncover and verify errors and inconsistencies in their modeling. A hierarchy of the National Cancer Institute thesaurus (NCIt) is used as our test-bed. A hypothesis pertaining to the expected error rates of the complex and simple concepts is tested. Our study was done on the NCIt's Biological Process hierarchy. Various errors, including missing roles, incorrect role targets, and incorrectly assigned roles, were discovered and verified in the two phases of our QA analysis. The overall findings confirmed our hypothesis by showing a statistically significant difference between the amounts of errors exhibited by more laterally complex concepts vis-à-vis simpler concepts. QA is an essential part of any ontology's maintenance regimen. In this paper, we reported on the results of a QA study targeting two groups of ontology concepts distinguished by their level of complexity, defined in terms of the number of exhibited role types. The study was carried out on a major component of an important ontology, the NCIt. The findings suggest that more complex concepts tend to have a higher error rate than simpler concepts. These findings can be utilized to guide ongoing efforts in ontology QA.

Fluctuation Dynamics of Exchange Rates on Indian Financial Market

NASA Astrophysics Data System (ADS)

Sarkar, A.; Barat, P.

Here we investigate the scaling behavior and the complexity of the average daily exchange rate returns of the Indian Rupee against four foreign currencies namely US Dollar, Euro, Great Britain Pound and Japanese Yen. Our analysis revealed that the average daily exchange rate return of the Indian Rupee against the US Dollar exhibits a persistent scaling behavior and follow Levy stable distribution. On the contrary the average daily exchange rate returns of the other three foreign currencies show randomness and follow Gaussian distribution. Moreover, it is seen that the complexity of the average daily exchange rate return of the Indian Rupee against US Dollar is less than the other three exchange rate returns.

Effects of guided breath exercise on complex behaviour of heart rate dynamics.

PubMed

Tavares, Bruna S; de Paula Vidigal, Giovanna; Garner, David M; Raimundo, Rodrigo D; de Abreu, Luiz Carlos; Valenti, Vitor E

2017-11-01

Cardiac autonomic regulation is influenced by changes in respiratory rate, which has been demonstrated by linear analysis of heart rate variability (HRV). Conversely, the complex behaviour is not well defined for HRV during this physiological state. In this sense, Higuchi Fractal Dimension is applied directly to the time series. It analyses the fractal dimension of discrete time sequences and is simpler and faster than correlation dimension and many other classical measures derived from chaos theory. We investigated chaotic behaviour of heart rate dynamics during guided breath exercises. We investigated 21 healthy male volunteers aged between 18 and 30 years. HRV was analysed 10 min before and 10 min during guided breath exercises. HRV was analysed in the time and frequency domain for linear analysis and through HFD for non-linear analysis. Linear analysis indicated that SDNN, pNN50, RMSSD, LF, HF and LF/HF increased during guided breath exercises. HFD analysis illustrated that between K max 20 to K max 120 intervals, was enhanced during guided breath exercises. Guided breath exercises acutely increased chaotic behaviour of HRV measured by HFD. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

The High Cost of Complexity in Experimental Design and Data Analysis: Type I and Type II Error Rates in Multiway ANOVA.

ERIC Educational Resources Information Center

Smith, Rachel A.; Levine, Timothy R.; Lachlan, Kenneth A.; Fediuk, Thomas A.

2002-01-01

Notes that the availability of statistical software packages has led to a sharp increase in use of complex research designs and complex statistical analyses in communication research. Reports a series of Monte Carlo simulations which demonstrate that this complexity may come at a heavier cost than many communication researchers realize. Warns…

Aging and the complexity of cardiovascular dynamics

NASA Technical Reports Server (NTRS)

Kaplan, D. T.; Furman, M. I.; Pincus, S. M.; Ryan, S. M.; Lipsitz, L. A.; Goldberger, A. L.

1991-01-01

Biomedical signals often vary in a complex and irregular manner. Analysis of variability in such signals generally does not address directly their complexity, and so may miss potentially useful information. We analyze the complexity of heart rate and beat-to-beat blood pressure using two methods motivated by nonlinear dynamics (chaos theory). A comparison of a group of healthy elderly subjects with healthy young adults indicates that the complexity of cardiovascular dynamics is reduced with aging. This suggests that complexity of variability may be a useful physiological marker.

[The clinical economic analysis of application of immune correcting preparations to prevent respiratory infections and their complications in frequently ill children of early school age].

PubMed

Maiorov, R V; Derbenov, D P

2014-01-01

The article presents the results of clinical economic analysis of effect of different immune correcting preparations on rate of respiratory infections in 548 frequently ill children of early school age. It is established that preventive immune correction with lysates of bacteria or glucosaminyl muramyl dipeptide in aggregate with vitamin mineral complex results in statistically significant decreasing of rate of respiratory infections and dramatic decreasing of direct and indirect costs of treatment of infectious diseases of respiratory ways. The preventive application of juice of cone-flower herb or interferon in aggregate with vitamnin mineral complex statistically significantly decreases rate of respiratory infections and negligibly decreases direct and indirect costs of their treatment.

Fractal Based Analysis of the Influence of Odorants on Heart Activity

NASA Astrophysics Data System (ADS)

Namazi, Hamidreza; Kulish, Vladimir V.

2016-12-01

An important challenge in heart research is to make the relation between the features of external stimuli and heart activity. Olfactory stimulation is an important type of stimulation that affects the heart activity, which is mapped on Electrocardiogram (ECG) signal. Yet, no one has discovered any relation between the structures of olfactory stimuli and the ECG signal. This study investigates the relation between the structures of heart rate and the olfactory stimulus (odorant). We show that the complexity of the heart rate is coupled with the molecular complexity of the odorant, where more structurally complex odorant causes less fractal heart rate. Also, odorant having higher entropy causes the heart rate having lower approximate entropy. The method discussed here can be applied and investigated in case of patients with heart diseases as the rehabilitation purpose.

Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization

NASA Astrophysics Data System (ADS)

Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

2015-08-01

The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress.

Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization

PubMed Central

Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

2015-01-01

The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress. PMID:26286628

Multiscale entropy analysis of heart rate variability in heart failure, hypertensive, and sinoaortic-denervated rats: classical and refined approaches.

PubMed

Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Castania, Jaci Airton; da Silva, Carlos Alberto Aguiar; Valencia, Jose Fernando; Murta, Luiz Otavio; Salgado, Helio Cesar; Fazan, Rubens; Porta, Alberto

2016-07-01

The analysis of heart rate variability (HRV) by nonlinear methods has been gaining increasing interest due to their ability to quantify the complexity of cardiovascular regulation. In this study, multiscale entropy (MSE) and refined MSE (RMSE) were applied to track the complexity of HRV as a function of time scale in three pathological conscious animal models: rats with heart failure (HF), spontaneously hypertensive rats (SHR), and rats with sinoaortic denervation (SAD). Results showed that HF did not change HRV complexity, although there was a tendency to decrease the entropy in HF animals. On the other hand, SHR group was characterized by reduced complexity at long time scales, whereas SAD animals exhibited a smaller short- and long-term irregularity. We propose that short time scales (1 to 4), accounting for fast oscillations, are more related to vagal and respiratory control, whereas long time scales (5 to 20), accounting for slow oscillations, are more related to sympathetic control. The increased sympathetic modulation is probably the main reason for the lower entropy observed at high scales for both SHR and SAD groups, acting as a negative factor for the cardiovascular complexity. This study highlights the contribution of the multiscale complexity analysis of HRV for understanding the physiological mechanisms involved in cardiovascular regulation. Copyright © 2016 the American Physiological Society.

An analysis of relational complexity in an air traffic control conflict detection task.

PubMed

Boag, Christine; Neal, Andrew; Loft, Shayne; Halford, Graeme S

2006-11-15

Theoretical analyses of air traffic complexity were carried out using the Method for the Analysis of Relational Complexity. Twenty-two air traffic controllers examined static air traffic displays and were required to detect and resolve conflicts. Objective measures of performance included conflict detection time and accuracy. Subjective perceptions of mental workload were assessed by a complexity-sorting task and subjective ratings of the difficulty of different aspects of the task. A metric quantifying the complexity of pair-wise relations among aircraft was able to account for a substantial portion of the variance in the perceived complexity and difficulty of conflict detection problems, as well as reaction time. Other variables that influenced performance included the mean minimum separation between aircraft pairs and the amount of time that aircraft spent in conflict.

Multi-complexity ensemble measures for gait time series analysis: application to diagnostics, monitoring and biometrics.

PubMed

Gavrishchaka, Valeriy; Senyukova, Olga; Davis, Kristina

2015-01-01

Previously, we have proposed to use complementary complexity measures discovered by boosting-like ensemble learning for the enhancement of quantitative indicators dealing with necessarily short physiological time series. We have confirmed robustness of such multi-complexity measures for heart rate variability analysis with the emphasis on detection of emerging and intermittent cardiac abnormalities. Recently, we presented preliminary results suggesting that such ensemble-based approach could be also effective in discovering universal meta-indicators for early detection and convenient monitoring of neurological abnormalities using gait time series. Here, we argue and demonstrate that these multi-complexity ensemble measures for gait time series analysis could have significantly wider application scope ranging from diagnostics and early detection of physiological regime change to gait-based biometrics applications.

Quasi-likelihood generalized linear regression analysis of fatality risk data

DOT National Transportation Integrated Search

2009-01-01

Transportation-related fatality risks is a function of many interacting human, vehicle, and environmental factors. Statisitcally valid analysis of such data is challenged both by the complexity of plausable structural models relating fatality rates t...

Initial fractal exponent of heart-rate variability is associated with success of early resuscitation in patients with severe sepsis or septic shock: a prospective cohort study

PubMed Central

Brown, Samuel M.; Tate, Quinn; Jones, Jason P.; Knox, Daniel; Kuttler, Kathryn G.; Lanspa, Michael; Rondina, Matthew T.; Grissom, Colin K.; Behera, Subhasis; Mathews, V.J.; Morris, Alan

2013-01-01

Introduction Heart-rate variability reflects autonomic nervous system tone as well as the overall health of the baroreflex system. We hypothesized that loss of complexity in heart-rate variability upon ICU admission would be associated with unsuccessful early resuscitation of sepsis. Methods We prospectively enrolled patients admitted to ICUs with severe sepsis or septic shock from 2009 to 2011. We studied 30 minutes of EKG, sampled at 500 Hz, at ICU admission and calculated heart-rate complexity via detrended fluctuation analysis. Primary outcome was vasopressor independence at 24 hours after ICU admission. Secondary outcome was 28-day mortality. Results We studied 48 patients, of whom 60% were vasopressor independent at 24 hours. Five (10%) died within 28 days. The ratio of fractal alpha parameters was associated with both vasopressor independence and 28-day mortality (p=0.04) after controlling for mean heart rate. In the optimal model, SOFA score and the long-term fractal alpha parameter were associated with vasopressor independence. Conclusions Loss of complexity in heart rate variability is associated with worse outcome early in severe sepsis and septic shock. Further work should evaluate whether complexity of heart rate variability (HRV) could guide treatment in sepsis. PMID:23958243

Medically complex pregnancies and early breastfeeding behaviors: a retrospective analysis.

PubMed

Kozhimannil, Katy B; Jou, Judy; Attanasio, Laura B; Joarnt, Lauren K; McGovern, Patricia

2014-01-01

Breastfeeding is beneficial for women and infants, and medical contraindications are rare. Prenatal and labor-related complications may hinder breastfeeding, but supportive hospital practices may encourage women who intend to breastfeed. We measured the relationship between having a complex pregnancy (entering pregnancy with hypertension, diabetes, or obesity) and early infant feeding, accounting for breastfeeding intentions and supportive hospital practices. We performed a retrospective analysis of data from a nationally-representative survey of women who gave birth in 2011-2012 in a US hospital (N = 2400). We used logistic regression to examine the relationship between pregnancy complexity and breastfeeding. Self-reported prepregnancy diabetes or hypertension, gestational diabetes, or obesity indicated a complex pregnancy. The outcome was feeding status 1 week postpartum; any breastfeeding was evaluated among women intending to breastfeed (N = 1990), and exclusive breastfeeding among women who intended to exclusively breastfeed (N = 1418). We also tested whether breastfeeding intentions or supportive hospital practices mediated the relationship between pregnancy complexity and infant feeding status. More than 33% of women had a complex pregnancy; these women had 30% lower odds of intending to breastfeed (AOR = 0.71; 95% CI, 0.52-0.98). Rates of intention to exclusively breastfeed were similar for women with and without complex pregnancies. Women who intended to breastfeed had similar rates of any breastfeeding 1 week postpartum regardless of pregnancy complexity, but complexity was associated with >30% lower odds of exclusive breastfeeding 1 week among women who intended to exclusively breastfeed (AOR = 0.68; 95% CI, 0.47-0.98). Supportive hospital practices were strongly associated with higher odds of any or exclusive breastfeeding 1 week postpartum (AOR = 4.03; 95% CI, 1.81-8.94; and AOR = 2.68; 95% CI, 1.70-4.23, respectively). Improving clinical and hospital support for women with complex pregnancies may increase breastfeeding rates and the benefits of breastfeeding for women and infants.

Software analysis handbook: Software complexity analysis and software reliability estimation and prediction

NASA Technical Reports Server (NTRS)

Lee, Alice T.; Gunn, Todd; Pham, Tuan; Ricaldi, Ron

1994-01-01

This handbook documents the three software analysis processes the Space Station Software Analysis team uses to assess space station software, including their backgrounds, theories, tools, and analysis procedures. Potential applications of these analysis results are also presented. The first section describes how software complexity analysis provides quantitative information on code, such as code structure and risk areas, throughout the software life cycle. Software complexity analysis allows an analyst to understand the software structure, identify critical software components, assess risk areas within a software system, identify testing deficiencies, and recommend program improvements. Performing this type of analysis during the early design phases of software development can positively affect the process, and may prevent later, much larger, difficulties. The second section describes how software reliability estimation and prediction analysis, or software reliability, provides a quantitative means to measure the probability of failure-free operation of a computer program, and describes the two tools used by JSC to determine failure rates and design tradeoffs between reliability, costs, performance, and schedule.

Bayesian uncertainty analysis for complex systems biology models: emulation, global parameter searches and evaluation of gene functions.

PubMed

Vernon, Ian; Liu, Junli; Goldstein, Michael; Rowe, James; Topping, Jen; Lindsey, Keith

2018-01-02

Many mathematical models have now been employed across every area of systems biology. These models increasingly involve large numbers of unknown parameters, have complex structure which can result in substantial evaluation time relative to the needs of the analysis, and need to be compared to observed data of various forms. The correct analysis of such models usually requires a global parameter search, over a high dimensional parameter space, that incorporates and respects the most important sources of uncertainty. This can be an extremely difficult task, but it is essential for any meaningful inference or prediction to be made about any biological system. It hence represents a fundamental challenge for the whole of systems biology. Bayesian statistical methodology for the uncertainty analysis of complex models is introduced, which is designed to address the high dimensional global parameter search problem. Bayesian emulators that mimic the systems biology model but which are extremely fast to evaluate are embeded within an iterative history match: an efficient method to search high dimensional spaces within a more formal statistical setting, while incorporating major sources of uncertainty. The approach is demonstrated via application to a model of hormonal crosstalk in Arabidopsis root development, which has 32 rate parameters, for which we identify the sets of rate parameter values that lead to acceptable matches between model output and observed trend data. The multiple insights into the model's structure that this analysis provides are discussed. The methodology is applied to a second related model, and the biological consequences of the resulting comparison, including the evaluation of gene functions, are described. Bayesian uncertainty analysis for complex models using both emulators and history matching is shown to be a powerful technique that can greatly aid the study of a large class of systems biology models. It both provides insight into model behaviour and identifies the sets of rate parameters of interest.

Impact of Spacecraft Shielding on Direct Ionization Soft Error Rates for sub-130 nm Technologies

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Xapsos, Michael A.; Stauffer, Craig A.; Jordan, Michael M.; Sanders, Anthony B.; Ladbury, Raymond L.; Oldham, Timothy R.; Marshall, Paul W.; Heidel, David F.; Rodbell, Kenneth P.

2010-01-01

We use ray tracing software to model various levels of spacecraft shielding complexity and energy deposition pulse height analysis to study how it affects the direct ionization soft error rate of microelectronic components in space. The analysis incorporates the galactic cosmic ray background, trapped proton, and solar heavy ion environments as well as the October 1989 and July 2000 solar particle events.

Impact of Spacecraft Shielding on Direct Ionization Soft Error Rates for Sub-130 nm Technologies

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Xapsos, Michael A.; Stauffer, Craig A.; Jordan, Thomas M.; Sanders, Anthony B.; Ladbury, Raymond L.; Oldham, Timothy R.; Marshall, Paul W.; Heidel, David F.; Rodbell, Kenneth P.

2010-01-01

We use ray tracing software to model various levels of spacecraft shielding complexity and energy deposition pulse height analysis to study how it affects the direct ionization soft error rate of microelectronic components in space. The analysis incorporates the galactic cosmic ray background, trapped proton, and solar heavy ion environments as well as the October 1989 and July 2000 solar particle events.

Cognitive Complexity, Attitudinal Affect, and Dispersion in Affect Ratings for Products.

PubMed

Durand, Richard M

1979-04-01

The purpose of this study was to examine the relationships between cognitive complexity, attitudinal affect, and dispersion of affect scores (N = 102 male business administration undergraduates). Models of automobiles and toothpaste brands were the content domains studied. Analysis using Pearson product-moment correlation supported the hypothesis that cognitive complex Ss had a lower level of affect and greater dispersion of affect scores than did simpler Ss.

Gender- and age-related differences in heart rate dynamics: are women more complex than men?

NASA Technical Reports Server (NTRS)

Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

1994-01-01

OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

Supramolecular structure of glibenclamide and β-cyclodextrins complexes.

PubMed

Lucio, David; Irache, Juan Manuel; Font, María; Martínez-Ohárriz, María Cristina

2017-09-15

Glibenclamide is an antidiabetic drug showing low bioavailability as consequence of its low solubility. To solve this drawback, the interaction with cyclodextrins has been proposed. The formation of GB-βCDs inclusion complexes was carried out using different methods, βCD derivatives and drug-to-cyclodextrin ratios. The structures of the corresponding complexes have been studied by molecular modelling, X-ray diffraction and differential thermal analysis. The dissolution behavior of inclusion complexes has been compared to that of pure GB. Dimeric inclusion complexes were obtained with different CD disposals, head-to-head for βCD and head-to-tail for HPβCD and RMβCD. Amorphous inclusion complexes were obtained by employing methods of freeze-drying or coevaporation in ammonia-water. However, crystalline structures were formed by kneading and coevaporation in ethanol/water in the case of GB-βCD complexes. The arrangement of these structures depended on the GB:βCD ratio, yielding cage type structures for 1:3 and 1:5 ratios and channel-type structures for higher GB contents. The amount of GB released and its dissolution rate was considerably increased by the use of amorphous inclusion complexes; whereas, slower GB release rates were found from crystalline inclusion complexes formed by kneading or coevaporation in ethanol/water. In addition, it was found that the porous structure strongly conditioned the GB dissolution rate from crystalline products. Copyright © 2017 Elsevier B.V. All rights reserved.

Route complexity and simulated physical ageing negatively influence wayfinding.

PubMed

Zijlstra, Emma; Hagedoorn, Mariët; Krijnen, Wim P; van der Schans, Cees P; Mobach, Mark P

2016-09-01

The aim of this age-simulation field experiment was to assess the influence of route complexity and physical ageing on wayfinding. Seventy-five people (aged 18-28) performed a total of 108 wayfinding tasks (i.e., 42 participants performed two wayfinding tasks and 33 performed one wayfinding task), of which 59 tasks were performed wearing gerontologic ageing suits. Outcome variables were wayfinding performance (i.e., efficiency and walking speed) and physiological outcomes (i.e., heart and respiratory rates). Analysis of covariance showed that persons on more complex routes (i.e., more floor and building changes) walked less efficiently than persons on less complex routes. In addition, simulated elderly participants perform worse in wayfinding than young participants in terms of speed (p < 0.001). Moreover, a linear mixed model showed that simulated elderly persons had higher heart rates and respiratory rates compared to young people during a wayfinding task, suggesting that simulated elderly consumed more energy during this task. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands

NASA Astrophysics Data System (ADS)

Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S. Ahmad

2015-04-01

A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s-1 scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction.

Spatiotemporal Permutation Entropy as a Measure for Complexity of Cardiac Arrhythmia

NASA Astrophysics Data System (ADS)

Schlemmer, Alexander; Berg, Sebastian; Lilienkamp, Thomas; Luther, Stefan; Parlitz, Ulrich

2018-05-01

Permutation entropy (PE) is a robust quantity for measuring the complexity of time series. In the cardiac community it is predominantly used in the context of electrocardiogram (ECG) signal analysis for diagnoses and predictions with a major application found in heart rate variability parameters. In this article we are combining spatial and temporal PE to form a spatiotemporal PE that captures both, complexity of spatial structures and temporal complexity at the same time. We demonstrate that the spatiotemporal PE (STPE) quantifies complexity using two datasets from simulated cardiac arrhythmia and compare it to phase singularity analysis and spatial PE (SPE). These datasets simulate ventricular fibrillation (VF) on a two-dimensional and a three-dimensional medium using the Fenton-Karma model. We show that SPE and STPE are robust against noise and demonstrate its usefulness for extracting complexity features at different spatial scales.

Dynamic analysis of heartbeat rate signals of epileptics using multidimensional phase space reconstruction approach

NASA Astrophysics Data System (ADS)

Su, Zhi-Yuan; Wu, Tzuyin; Yang, Po-Hua; Wang, Yeng-Tseng

2008-04-01

The heartbeat rate signal provides an invaluable means of assessing the sympathetic-parasympathetic balance of the human autonomic nervous system and thus represents an ideal diagnostic mechanism for detecting a variety of disorders such as epilepsy, cardiac disease and so forth. The current study analyses the dynamics of the heartbeat rate signal of known epilepsy sufferers in order to obtain a detailed understanding of the heart rate pattern during a seizure event. In the proposed approach, the ECG signals are converted into heartbeat rate signals and the embedology theorem is then used to construct the corresponding multidimensional phase space. The dynamics of the heartbeat rate signal are then analyzed before, during and after an epileptic seizure by examining the maximum Lyapunov exponent and the correlation dimension of the attractors in the reconstructed phase space. In general, the results reveal that the heartbeat rate signal transits from an aperiodic, highly-complex behaviour before an epileptic seizure to a low dimensional chaotic motion during the seizure event. Following the seizure, the signal trajectories return to a highly-complex state, and the complex signal patterns associated with normal physiological conditions reappear.

Multifractality and heteroscedastic dynamics: An application to time series analysis

NASA Astrophysics Data System (ADS)

Nascimento, C. M.; Júnior, H. B. N.; Jennings, H. D.; Serva, M.; Gleria, Iram; Viswanathan, G. M.

2008-01-01

An increasingly important problem in physics concerns scale invariance symmetry in diverse complex systems, often characterized by heteroscedastic dynamics. We investigate the nature of the relationship between the heteroscedastic and fractal aspects of the dynamics of complex systems, by analyzing the sensitivity to heteroscedasticity of the scaling properties of weakly nonstationary time series. By using multifractal detrended fluctuation analysis, we study the singularity spectra of currency exchange rate fluctuations, after partially or completely eliminating n-point correlations via data shuffling techniques. We conclude that heteroscedasticity can significantly increase multifractality and interpret these findings in the context of self-organizing and adaptive complex systems.

Academic status does not affect outcome following complex hepato-pancreato-biliary procedures.

PubMed

Altieri, Maria S; Yang, Jie; Groves, Donald; Yin, Donglei; Cagino, Kristen; Talamini, Mark; Pryor, Aurora

2018-05-01

There is a growing debate regarding outcomes following complex hepato-pancreato-biliary (HPB) procedures. The purpose of our study is to examine if facility type has any impact on complications, readmission rates, emergency department (ED) visit rates, and length of stay (LOS) for patients undergoing HPB surgery. The SPARCS administrative database was used to identify patients undergoing complex HPB procedures between 2012 and 2014 in New York. Univariate generalized linear mixed models were fit to estimate the marginal association between outcomes such as overall/severe complication rates, 30-day and 1-year readmission rates, 30-day and 1-year ED-visit rates, and potential risk factors. Univariate linear mixed models were used to estimate the marginal association between possible risk factors and LOS. Facility type, as well as any variables found to be significant in our univariate analysis (p = 0.05), was further included in the multivariable regression models. There were 4122 complex HPB procedures performed. Academic facilities were more likely to have a higher hospital volume (p < 0001). Surgery at academic facilities were less likely to have coexisting comorbidities; however, they were more likely to have metastatic cancer and/or liver disease (p = 0.0114, < 0. 0001, and = 0.0299, respectively). Postoperatively, patients at non-academic facilities experienced higher overall complication rates, and higher severe complication rates, when compared to those at academic facilities (p < 0.0001 and = 0.0018, respectively). Further analysis via adjustment for possible confounding factors, however, revealed no significant difference in the risk of severe complications between the two facility types. Such adjustment also demonstrated higher 30-day readmission risk in patients who underwent their surgery at an academic facility. No significant difference was found when comparing the outcomes of academic and non-academic facilities, after adjusting for age, gender, race, region, insurance, and hospital volume. Patients from academic facilities were more likely to be readmitted within the first 30-days after surgery.

Complexity reduction of biochemical rate expressions.

PubMed

Schmidt, Henning; Madsen, Mads F; Danø, Sune; Cedersund, Gunnar

2008-03-15

The current trend in dynamical modelling of biochemical systems is to construct more and more mechanistically detailed and thus complex models. The complexity is reflected in the number of dynamic state variables and parameters, as well as in the complexity of the kinetic rate expressions. However, a greater level of complexity, or level of detail, does not necessarily imply better models, or a better understanding of the underlying processes. Data often does not contain enough information to discriminate between different model hypotheses, and such overparameterization makes it hard to establish the validity of the various parts of the model. Consequently, there is an increasing demand for model reduction methods. We present a new reduction method that reduces complex rational rate expressions, such as those often used to describe enzymatic reactions. The method is a novel term-based identifiability analysis, which is easy to use and allows for user-specified reductions of individual rate expressions in complete models. The method is one of the first methods to meet the classical engineering objective of improved parameter identifiability without losing the systems biology demand of preserved biochemical interpretation. The method has been implemented in the Systems Biology Toolbox 2 for MATLAB, which is freely available from http://www.sbtoolbox2.org. The Supplementary Material contains scripts that show how to use it by applying the method to the example models, discussed in this article.

Phonetic complexity and stuttering in Spanish

PubMed Central

Howell, Peter; Au-Yeung, James

2007-01-01

The current study investigated whether phonetic complexity affected stuttering rate for Spanish speakers. The speakers were assigned to three age groups (6-11, 12-17 and 18 years plus) that were similar to those used in an earlier study on English. The analysis was performed using Jakielski's (1998) Index of Phonetic Complexity (IPC) scheme in which each word is given an IPC score based on the number of complex attributes it includes for each of eight factors. Stuttering on function words for Spanish did not correlate with IPC score for any age group. This mirrors the finding for English that stuttering on these words is not affected by phonetic complexity. The IPC scores of content words correlated positively with stuttering rate for 6-11 year old and adult speakers. Comparison was made between the languages to establish whether or not experience with the factors determines the problem they pose for speakers (revealed by differences in stuttering rate). Evidence was obtained that four factors found to be important determinants of stuttering on content words in English for speakers aged 12 and above, also affected Spanish speakers. This occurred despite large differences in frequency of usage of these factors. It is concluded that phonetic factors affect stuttering rate irrespective of a speaker's experience with that factor. PMID:17364620

Phonetic complexity and stuttering in Spanish.

PubMed

Howell, Peter; Au-Yeung, James

2007-02-01

The current study investigated whether phonetic complexity affected stuttering rate for Spanish speakers. The speakers were assigned to three age groups (6-11, 12-17 and 18-years plus) that were similar to those used in an earlier study on English. The analysis was performed using Jakielski's Index of Phonetic Complexity (IPC) scheme in which each word is given an IPC score based on the number of complex attributes it includes for each of eight factors. Stuttering on function words for Spanish did not correlate with IPC score for any age group. This mirrors the finding for English that stuttering on these words is not affected by phonetic complexity. The IPC scores of content words correlated positively with stuttering rate for 6-11-year-old and adult speakers. Comparison was made between the languages to establish whether or not experience with the factors determines the problem they pose for speakers (revealed by differences in stuttering rate). Evidence was obtained that four factors found to be important determinants of stuttering on content words in English for speakers aged 12 and above, also affected Spanish speakers. This occurred despite large differences in frequency of usage of these factors. It is concluded that phonetic factors affect stuttering rate irrespective of a speaker's experience with that factor.

A Complex-Valued Firing-Rate Model That Approximates the Dynamics of Spiking Networks

PubMed Central

Schaffer, Evan S.; Ostojic, Srdjan; Abbott, L. F.

2013-01-01

Firing-rate models provide an attractive approach for studying large neural networks because they can be simulated rapidly and are amenable to mathematical analysis. Traditional firing-rate models assume a simple form in which the dynamics are governed by a single time constant. These models fail to replicate certain dynamic features of populations of spiking neurons, especially those involving synchronization. We present a complex-valued firing-rate model derived from an eigenfunction expansion of the Fokker-Planck equation and apply it to the linear, quadratic and exponential integrate-and-fire models. Despite being almost as simple as a traditional firing-rate description, this model can reproduce firing-rate dynamics due to partial synchronization of the action potentials in a spiking model, and it successfully predicts the transition to spike synchronization in networks of coupled excitatory and inhibitory neurons. PMID:24204236

Designing novel cellulase systems through agent-based modeling and global sensitivity analysis.

PubMed

Apte, Advait A; Senger, Ryan S; Fong, Stephen S

2014-01-01

Experimental techniques allow engineering of biological systems to modify functionality; however, there still remains a need to develop tools to prioritize targets for modification. In this study, agent-based modeling (ABM) was used to build stochastic models of complexed and non-complexed cellulose hydrolysis, including enzymatic mechanisms for endoglucanase, exoglucanase, and β-glucosidase activity. Modeling results were consistent with experimental observations of higher efficiency in complexed systems than non-complexed systems and established relationships between specific cellulolytic mechanisms and overall efficiency. Global sensitivity analysis (GSA) of model results identified key parameters for improving overall cellulose hydrolysis efficiency including: (1) the cellulase half-life, (2) the exoglucanase activity, and (3) the cellulase composition. Overall, the following parameters were found to significantly influence cellulose consumption in a consolidated bioprocess (CBP): (1) the glucose uptake rate of the culture, (2) the bacterial cell concentration, and (3) the nature of the cellulase enzyme system (complexed or non-complexed). Broadly, these results demonstrate the utility of combining modeling and sensitivity analysis to identify key parameters and/or targets for experimental improvement.

Designing novel cellulase systems through agent-based modeling and global sensitivity analysis

PubMed Central

Apte, Advait A; Senger, Ryan S; Fong, Stephen S

2014-01-01

Experimental techniques allow engineering of biological systems to modify functionality; however, there still remains a need to develop tools to prioritize targets for modification. In this study, agent-based modeling (ABM) was used to build stochastic models of complexed and non-complexed cellulose hydrolysis, including enzymatic mechanisms for endoglucanase, exoglucanase, and β-glucosidase activity. Modeling results were consistent with experimental observations of higher efficiency in complexed systems than non-complexed systems and established relationships between specific cellulolytic mechanisms and overall efficiency. Global sensitivity analysis (GSA) of model results identified key parameters for improving overall cellulose hydrolysis efficiency including: (1) the cellulase half-life, (2) the exoglucanase activity, and (3) the cellulase composition. Overall, the following parameters were found to significantly influence cellulose consumption in a consolidated bioprocess (CBP): (1) the glucose uptake rate of the culture, (2) the bacterial cell concentration, and (3) the nature of the cellulase enzyme system (complexed or non-complexed). Broadly, these results demonstrate the utility of combining modeling and sensitivity analysis to identify key parameters and/or targets for experimental improvement. PMID:24830736

Concentration-independent pH detection with a luminescent dimetallic Eu(III)-based probe.

PubMed

Moore, Jeremiah D; Lord, Richard L; Cisneros, G Andrés; Allen, Matthew J

2012-10-24

A pH-responsive, luminescent, dimetallic Eu(III)-containing complex has been synthesized and exhibits a unique mechanism of response. The luminescence-decay rate of the complex is slow, due to a lack of water molecules coordinated to the Eu(III) ions. However, the luminescence-decay rate decreases with increasing pH over a biologically relevant range of 4-8. Physical characterization and computational analysis suggest that the pH response is due to protonation of a bridging alkoxide at lower pH values. Modulation of the luminescence-decay rate is independent from the concentration of Eu(III), which we expect to be useful in the non-invasive imaging of in vivo pH.

Characterization of local complex structures in a recurrence plot to improve nonlinear dynamic discriminant analysis.

PubMed

Ding, Hang

2014-01-01

Structures in recurrence plots (RPs), preserving the rich information of nonlinear invariants and trajectory characteristics, have been increasingly analyzed in dynamic discrimination studies. The conventional analysis of RPs is mainly focused on quantifying the overall diagonal and vertical line structures through a method, called recurrence quantification analysis (RQA). This study extensively explores the information in RPs by quantifying local complex RP structures. To do this, an approach was developed to analyze the combination of three major RQA variables: determinism, laminarity, and recurrence rate (DLR) in a metawindow moving over a RP. It was then evaluated in two experiments discriminating (1) ideal nonlinear dynamic series emulated from the Lorenz system with different control parameters and (2) data sets of human heart rate regulations with normal sinus rhythms (n = 18) and congestive heart failure (n = 29). Finally, the DLR was compared with seven major RQA variables in terms of discriminatory power, measured by standardized mean difference (DSMD). In the two experiments, DLR resulted in the highest discriminatory power with DSMD = 2.53 and 0.98, respectively, which were 7.41 and 2.09 times the best performance from RQA. The study also revealed that the optimal RP structures for the discriminations were neither typical diagonal structures nor vertical structures. These findings indicate that local complex RP structures contain some rich information unexploited by RQA. Therefore, future research to extensively analyze complex RP structures would potentially improve the effectiveness of the RP analysis in dynamic discrimination studies.

Functional complexity and ecosystem stability: an experimental approach

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

Van Voris, P.; O'Neill, R.V.; Shugart, H.H.

1978-01-01

The complexity-stability hypothesis was experimentally tested using intact terrestrial microcosms. Functional complexity was defined as the number and significance of component interactions (i.e., population interactions, physical-chemical reactions, biological turnover rates) influenced by nonlinearities, feedbacks, and time delays. It was postulated that functional complexity could be nondestructively measured through analysis of a signal generated from the system. Power spectral analysis of hourly CO/sub 2/ efflux, from eleven old-field microcosms, was analyzed for the number of low frequency peaks and used to rank the functional complexity of each system. Ranking of ecosystem stability was based on the capacity of the system tomore » retain essential nutrients and was measured by net loss of Ca after the system was stressed. Rank correlation supported the hypothesis that increasing ecosystem functional complexity leads to increasing ecosystem stability. The results indicated that complex functional dynamics can serve to stabilize the system. The results also demonstrated that microcosms are useful tools for system-level investigations.« less

42 CFR 421.501 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... licensed medical professional, for a billed item or service identified by data analysis techniques or probe... rate based on the results of a probe review prior to the initiation of complex medical review. Medical... licensed medical professional, for a billed item or service identified by data analysis techniques or probe...

42 CFR 421.501 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... licensed medical professional, for a billed item or service identified by data analysis techniques or probe... rate based on the results of a probe review prior to the initiation of complex medical review. Medical... licensed medical professional, for a billed item or service identified by data analysis techniques or probe...

42 CFR 421.501 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... licensed medical professional, for a billed item or service identified by data analysis techniques or probe... rate based on the results of a probe review prior to the initiation of complex medical review. Medical... licensed medical professional, for a billed item or service identified by data analysis techniques or probe...

Ancillary Ligand Effects upon the Photochemistry of Mn(bpy)(CO)3X Complexes (X = Br-, PhCC-).

PubMed

Yempally, Veeranna; Moncho, Salvador; Hasanayn, Faraj; Fan, Wai Yip; Brothers, Edward N; Bengali, Ashfaq A

2017-09-18

The photochemistry of two Mn(bpy)(CO) 3 X complexes (X = PhCC - , Br - ) has been studied in the coordinating solvents THF (terahydrofuran) and MeCN (acetonitrile) employing time-resolved infrared spectroscopy. The two complexes are found to exhibit strikingly different photoreactivities and solvent dependencies. In MeCN, photolysis of 1-(CO)(Br) [1 = Mn(bpy)(CO) 2 ] affords the ionic complex [1-(MeCN) 2 ]Br as a final product. In contrast, photolysis of 1-(CO)(CCPh) in MeCN results in facial to meridional isomerization of the parent complex. When THF is used as solvent, photolysis results in facial to meridional isomerization in both complexes, though the isomerization rate is larger for X = Br - . Pronounced differences are also observed in the photosubstitution chemistry of the two complexes where both the rate of MeCN exchange from 1-(MeCN)(X) by THFA (tetrahydrofurfurylamine) and the nature of the intermediates generated in the reaction are dependent upon X. DFT calculations are used to support analysis of some of the experiments.

Analysis of Numerical Models for Dispersion of Chemical/Biological Agents in Complex Building Environments

DTIC Science & Technology

2004-11-01

variation in ventilation rates over time and the distribution of ventilation air within a building, and to estimate the impact of envelope air ... tightening efforts on infiltration rates. • It may be used to determine the indoor air quality performance of a building before construction, and to

Determination of association constants at moderately fast chemical exchange: complexation of camphor enantiomers by alpha-cyclodextrin.

PubMed

Bernatowicz, Piotr; Nowakowski, Michał; Dodziuk, Helena; Ejchart, Andrzej

2006-08-01

Association constants in weak molecular complexes can be determined by analysis of chemical shifts variations resulting from changes of guest to host concentration ratio. In the regime of very fast exchange, i.e., when exchange rate is several orders of magnitude larger than the Larmor angular frequency difference of the observed resonance in free and complexed molecule, the apparent position of averaged resonance is a population-weighted mean of resonances of particular forms involved in the equilibrium. The assumption of very fast exchange is often, however, tacitly admitted in literature even in cases where the process of interest is much slower than required. We show that such an unjustified simplification may, under certain circumstances, lead to significant underestimation of association constant and, in consequence, to non-negligible errors in Gibbs free energy under determination. We present a general method, based on iterative numerical NMR line shape analysis, which allows one for the compensation of chemical exchange effects, and delivers both the correct association constants and the exchange rates. The latter are not delivered by the other mentioned method. Practical application of our algorithm is illustrated by the case of camphor-alpha-cyclodextrin complexes.

Psychophysiology of Aggression, Psychopathy, and Conduct Problems: A Meta-Analysis

ERIC Educational Resources Information Center

Lorber, Michael F.

2004-01-01

A meta-analysis of 95 studies was conducted to investigate the relations of heart rate (HR) and electrodermal activity (EDA) with aggression, psychopathy, and conduct problems. Analyses revealed a complex constellation of interactive effects, with a failure in some cases of autonomic patterns to generalize across antisocial spectrum behavior…

Complexity and time asymmetry of heart rate variability are altered in acute mental stress.

PubMed

Visnovcova, Z; Mestanik, M; Javorka, M; Mokra, D; Gala, M; Jurko, A; Calkovska, A; Tonhajzerova, I

2014-07-01

We aimed to study the complexity and time asymmetry of short-term heart rate variability (HRV) as an index of complex neurocardiac control in response to stress using symbolic dynamics and time irreversibility methods. ECG was recorded at rest and during and after two stressors (Stroop, arithmetic test) in 70 healthy students. Symbolic dynamics parameters (NUPI, NCI, 0V%, 1V%, 2LV%, 2UV%), and time irreversibility indices (P%, G%, E) were evaluated. Additionally, HRV magnitude was quantified by linear parameters: spectral powers in low (LF) and high frequency (HF) bands. Our results showed a reduction of HRV complexity in stress (lower NUPI with both stressors, lower NCI with Stroop). Pattern classification analysis revealed significantly higher 0V% and lower 2LV% with both stressors, indicating a shift in sympathovagal balance, and significantly higher 1V% and lower 2UV% with Stroop. An unexpected result was found in time irreversibility: significantly lower G% and E with both stressors, P% index significantly declined only with arithmetic test. Linear HRV analysis confirmed vagal withdrawal (lower HF) with both stressors; LF significantly increased with Stroop and decreased with arithmetic test. Correlation analysis revealed no significant associations between symbolic dynamics and time irreversibility. Concluding, symbolic dynamics and time irreversibility could provide independent information related to alterations of neurocardiac control integrity in stress-related disease.

[Study on the mode of inheritance for familial polycystic ovary syndrome].

PubMed

Mao, W; Li, M; Chen, Y; Lu, C; Wang, Y; Zhang, X; Qiao, J; Wang, A

2001-02-01

To investigate the mode of inheritance of polycystic ovary syndrome(PCOS). The first female relatives with irregular cycle and the first male relatives with premature balding in each nuclear family were designated the affected. Their prevalence rates in families were respectively calculated. Analyses of segregation ratio were carried out among 139 nuclear families with PCOS by the methods of simple segregation and complex segregation of genetic epidemiology, respectively. The prevalence rates of irregular cycle among mothers and sisters with PCOS were 37.4% and 33.1% respectively, and the prevalence rates of premature balding among fathers and brothers of patients were 19.4% and 6.5%, respectively. The simple segregation analysis indicated that the segregation ratio of PCOS trait in siblings was 0.3023, the complex segregation analysis indicated that it fitted in with the inheritance model of co-dominant disorder with full penetrance and sporadic cases. The frequency of homozygote of disease gene in population was 0.046. PCOS presents the mode of co-dominant inheritance with complete penetrance.

Methodology and Results of Mathematical Modelling of Complex Technological Processes

NASA Astrophysics Data System (ADS)

Mokrova, Nataliya V.

2018-03-01

The methodology of system analysis allows us to draw a mathematical model of the complex technological process. The mathematical description of the plasma-chemical process was proposed. The importance the quenching rate and initial temperature decrease time was confirmed for producing the maximum amount of the target product. The results of numerical integration of the system of differential equations can be used to describe reagent concentrations, plasma jet rate and temperature in order to achieve optimal mode of hardening. Such models are applicable both for solving control problems and predicting future states of sophisticated technological systems.

Sleep stage classification with low complexity and low bit rate.

PubMed

Virkkala, Jussi; Värri, Alpo; Hasan, Joel; Himanen, Sari-Leena; Müller, Kiti

2009-01-01

Standard sleep stage classification is based on visual analysis of central (usually also frontal and occipital) EEG, two-channel EOG, and submental EMG signals. The process is complex, using multiple electrodes, and is usually based on relatively high (200-500 Hz) sampling rates. Also at least 12 bit analog to digital conversion is recommended (with 16 bit storage) resulting in total bit rate of at least 12.8 kbit/s. This is not a problem for in-house laboratory sleep studies, but in the case of online wireless self-applicable ambulatory sleep studies, lower complexity and lower bit rates are preferred. In this study we further developed earlier single channel facial EMG/EOG/EEG-based automatic sleep stage classification. An algorithm with a simple decision tree separated 30 s epochs into wakefulness, SREM, S1/S2 and SWS using 18-45 Hz beta power and 0.5-6 Hz amplitude. Improvements included low complexity recursive digital filtering. We also evaluated the effects of a reduced sampling rate, reduced number of quantization steps and reduced dynamic range on the sleep data of 132 training and 131 testing subjects. With the studied algorithm, it was possible to reduce the sampling rate to 50 Hz (having a low pass filter at 90 Hz), and the dynamic range to 244 microV, with an 8 bit resolution resulting in a bit rate of 0.4 kbit/s. Facial electrodes and a low bit rate enables the use of smaller devices for sleep stage classification in home environments.

Spectral simplicity of apparent complexity. II. Exact complexities and complexity spectra

NASA Astrophysics Data System (ADS)

Riechers, Paul M.; Crutchfield, James P.

2018-03-01

The meromorphic functional calculus developed in Part I overcomes the nondiagonalizability of linear operators that arises often in the temporal evolution of complex systems and is generic to the metadynamics of predicting their behavior. Using the resulting spectral decomposition, we derive closed-form expressions for correlation functions, finite-length Shannon entropy-rate approximates, asymptotic entropy rate, excess entropy, transient information, transient and asymptotic state uncertainties, and synchronization information of stochastic processes generated by finite-state hidden Markov models. This introduces analytical tractability to investigating information processing in discrete-event stochastic processes, symbolic dynamics, and chaotic dynamical systems. Comparisons reveal mathematical similarities between complexity measures originally thought to capture distinct informational and computational properties. We also introduce a new kind of spectral analysis via coronal spectrograms and the frequency-dependent spectra of past-future mutual information. We analyze a number of examples to illustrate the methods, emphasizing processes with multivariate dependencies beyond pairwise correlation. This includes spectral decomposition calculations for one representative example in full detail.

Divergence times and the evolution of morphological complexity in an early land plant lineage (Marchantiopsida) with a slow molecular rate.

PubMed

Villarreal A, Juan Carlos; Crandall-Stotler, Barbara J; Hart, Michelle L; Long, David G; Forrest, Laura L

2016-03-01

We present a complete generic-level phylogeny of the complex thalloid liverworts, a lineage that includes the model system Marchantia polymorpha. The complex thalloids are remarkable for their slow rate of molecular evolution and for being the only extant plant lineage to differentiate gas exchange tissues in the gametophyte generation. We estimated the divergence times and analyzed the evolutionary trends of morphological traits, including air chambers, rhizoids and specialized reproductive structures. A multilocus dataset was analyzed using maximum likelihood and Bayesian approaches. Relative rates were estimated using local clocks. Our phylogeny cements the early branching in complex thalloids. Marchantia is supported in one of the earliest divergent lineages. The rate of evolution in organellar loci is slower than for other liverwort lineages, except for two annual lineages. Most genera diverged in the Cretaceous. Marchantia polymorpha diversified in the Late Miocene, giving a minimum age estimate for the evolution of its sex chromosomes. The complex thalloid ancestor, excluding Blasiales, is reconstructed as a plant with a carpocephalum, with filament-less air chambers opening via compound pores, and without pegged rhizoids. Our comprehensive study of the group provides a temporal framework for the analysis of the evolution of critical traits essential for plants during land colonization. © 2015 Royal Botanic Garden Edinburgh. New Phytologist © 2015 New Phytologist Trust.

A Business School Living Learning Community: A Complexity Theory Study of Collaborative Engagement Using Network Analysis

ERIC Educational Resources Information Center

De Iulio, Edward B.

2017-01-01

As funding for institutions of higher education becomes tighter, state and federal entities have turned to student retention and graduation rates as measures of success to determine levels of financial support. A concept, supported by student development theories, used to increase retention and graduation rates is creating living learning…

Managing Rater Effects through the Use of FACETS Analysis: The Case of a University Placement Test

ERIC Educational Resources Information Center

Wu, Siew Mei; Tan, Susan

2016-01-01

Rating essays is a complex task where students' grades could be adversely affected by test-irrelevant factors such as rater characteristics and rating scales. Understanding these factors and controlling their effects are crucial for test validity. Rater behaviour has been extensively studied through qualitative methods such as questionnaires and…

Lack of consensus among competency ratings of the same occupation: noise or substance?

PubMed

Lievens, Filip; Sanchez, Juan I; Bartram, Dave; Brown, Anna

2010-05-01

Although rating differences among incumbents of the same occupation have traditionally been viewed as error variance in the work analysis domain, such differences might often capture substantive discrepancies in how incumbents approach their work. This study draws from job crafting, creativity, and role theories to uncover situational factors (i.e., occupational activities, context, and complexity) related to differences among competency ratings of the same occupation. The sample consisted of 192 incumbents from 64 occupations. Results showed that 25% of the variance associated with differences in competency ratings of the same occupation was related to the complexity, the context, and primarily the nature of the occupation's work activities. Consensus was highest for occupations involving equipment-related activities and direct contact with the public. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Copper(II) complexes as catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine

NASA Astrophysics Data System (ADS)

Khattar, Raghvi; Yadav, Anjana; Mathur, Pavan

2015-05-01

Two new mononuclear copper(II) complexes [Cu (L) (NO3)2] (1) and [Cu (L) Br2] (2) where (L = bis(1-(pyridin-2-ylmethyl)-benzimidazol-2-ylmethyl)ether) are synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, UV-Visible, IR spectroscopy, EPR and cyclic voltammetry. The complexes exhibit different coordination structures; the E1/2 value of the complex (1) is found to be relatively more cathodic than that of complex (2). X-band EPR spectra at low temperature in DMF supports a tetragonally distorted complex (1) while complex (2) shows three different g values suggesting a rhombic geometry. These complexes were utilized as a catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine assisted by molecular oxygen. The initial rate of reaction is dependent on the concentration of Cu(II) complex as well as substrate, and was found to be higher for the nitrate bound complex, while presence of acetate anion acts as a mild inhibitor of the reaction, as it is likely to pick up protons generated during the course of reaction. The inhibition suggests that the generated protons are further required in another important catalytic step.

Reduced heart rate variability during sleep in long-duration spaceflight.

PubMed

Xu, D; Shoemaker, J K; Blaber, A P; Arbeille, P; Fraser, K; Hughson, R L

2013-07-15

Limited data are available to describe the regulation of heart rate (HR) during sleep in spaceflight. Sleep provides a stable supine baseline during preflight Earth recordings for comparison of heart rate variability (HRV) over a wide range of frequencies using both linear, complexity, and fractal indicators. The current study investigated the effect of long-duration spaceflight on HR and HRV during sleep in seven astronauts aboard the International Space Station up to 6 mo. Measurements included electrocardiographic waveforms from Holter monitors and simultaneous movement records from accelerometers before, during, and after the flights. HR was unchanged inflight and elevated postflight [59.6 ± 8.9 beats per minute (bpm) compared with preflight 53.3 ± 7.3 bpm; P < 0.01]. Compared with preflight data, HRV indicators from both time domain and power spectral analysis methods were diminished inflight from ultralow to high frequencies and partially recovered to preflight levels after landing. During inflight and at postflight, complexity and fractal properties of HR were not different from preflight properties. Slow fluctuations (<0.04 Hz) in HR presented moderate correlations with movements during sleep, partially accounting for the reduction in HRV. In summary, substantial reduction in HRV was observed with linear, but not with complexity and fractal, methods of analysis. These results suggest that periodic elements that influence regulation of HR through reflex mechanisms are altered during sleep in spaceflight but that underlying system complexity and fractal dynamics were not altered.

Highly Active N,O Zinc Guanidine Catalysts for the Ring-Opening Polymerization of Lactide.

PubMed

Schäfer, Pascal M; Fuchs, Martin; Ohligschläger, Andreas; Rittinghaus, Ruth; McKeown, Paul; Akin, Enver; Schmidt, Maximilian; Hoffmann, Alexander; Liauw, Marcel A; Jones, Matthew D; Herres-Pawlis, Sonja

2017-09-22

New zinc guanidine complexes with N,O donor functionalities were prepared, characterized by X-Ray crystallography, and examined for their catalytic activity in the solvent-free ring-opening polymerization (ROP) of technical-grade rac-lactide at 150 °C. All complexes showed a high activity. The fastest complex [ZnCl 2 (DMEGasme)] (C1) produced colorless poly(lactide) (PLA) after 90 min with a conversion of 52 % and high molar masses (M w =69 100, polydispersity=1.4). The complexes were tested with different monomer-to-initiator ratios to determine the rate constant k p . Furthermore, a polymerization with the most active complex C1 was monitored by in situ Raman spectroscopy. Overall, conversion of up to 90 % can be obtained. End-group analysis was performed to clarify the mechanism. All four complexes combine robustness against impurities in the lactide with high polymerization rates, and they represent the fastest robust lactide ROP catalysts to date, opening new avenues to a sustainable ROP catalyst family for industrial use. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of the methods for assessing socio-economic development level of urban areas

NASA Astrophysics Data System (ADS)

Popova, Olga; Bogacheva, Elena

2017-01-01

The present paper provides a targeted analysis of current approaches (ratings) in the assessment of socio-economic development of urban areas. The survey focuses on identifying standardized methodologies to area assessment techniques formation that will result in developing the system of intelligent monitoring, dispatching, building management, scheduling and effective management of an administrative-territorial unit. This system is characterized by complex hierarchical structure, including tangible and intangible properties (parameters, attributes). Investigating the abovementioned methods should increase the administrative-territorial unit's attractiveness for investors and residence. The research aims at studying methods for evaluating socio-economic development level of the Russian Federation territories. Experimental and theoretical territory estimating methods were revealed. Complex analysis of the characteristics of the areas was carried out and evaluation parameters were determined. Integral indicators (resulting rating criteria values) as well as the overall rankings (parameters, characteristics) were analyzed. The inventory of the most widely used partial indicators (parameters, characteristics) of urban areas was revealed. The resulting criteria of rating values homogeneity were verified and confirmed by determining the root mean square deviation, i.e. divergence of indices. The principal shortcomings of assessment methodologies were revealed. The assessment methods with enhanced effectiveness and homogeneity were proposed.

Permutation entropy analysis of heart rate variability for the assessment of cardiovascular autonomic neuropathy in type 1 diabetes mellitus.

PubMed

Carricarte Naranjo, Claudia; Sanchez-Rodriguez, Lazaro M; Brown Martínez, Marta; Estévez Báez, Mario; Machado García, Andrés

2017-07-01

Heart rate variability (HRV) analysis is a relevant tool for the diagnosis of cardiovascular autonomic neuropathy (CAN). To our knowledge, no previous investigation on CAN has assessed the complexity of HRV from an ordinal perspective. Therefore, the aim of this work is to explore the potential of permutation entropy (PE) analysis of HRV complexity for the assessment of CAN. For this purpose, we performed a short-term PE analysis of HRV in healthy subjects and type 1 diabetes mellitus patients, including patients with CAN. Standard HRV indicators were also calculated in the control group. A discriminant analysis was used to select the variables combination with best discriminative power between control and CAN patients groups, as well as for classifying cases. We found that for some specific temporal scales, PE indicators were significantly lower in CAN patients than those calculated for controls. In such cases, there were ordinal patterns with high probabilities of occurrence, while others were hardly found. We posit this behavior occurs due to a decrease of HRV complexity in the diseased system. Discriminant functions based on PE measures or probabilities of occurrence of ordinal patterns provided an average of 75% and 96% classification accuracy. Correlations of PE and HRV measures showed to depend only on temporal scale, regardless of pattern length. PE analysis at some specific temporal scales, seem to provide additional information to that obtained with traditional HRV methods. We concluded that PE analysis of HRV is a promising method for the assessment of CAN. Copyright © 2017 Elsevier Ltd. All rights reserved.

Desorption of Hg(II) and Sb(V) on extracellular polymeric substances: effects of pH, EDTA, Ca(II) and temperature shocks.

PubMed

Zhang, Daoyong; Lee, Duu-Jong; Pan, Xiangliang

2013-01-01

Extracellular polymeric substances (EPS) existed ubiquitously in biological systems affect the mobility and availability of heavy metals in the environments. The adsorption-desorption behaviors of Hg(II) and Sb(V) on EPS were investigated. The sorption rates follow Sb(V) > Hg(II), and the desorption rates follow reverse order. Applications of ethylene diamine tetraacetic acid (EDTA), Ca(II) and pH shocks affect desorption rates and desorbed quantities of Hg(II) from EPS-Hg complex. Temperature shock minimally affects the desorption rate of Hg(II). Conversely, the EPS-Sb complex is stable subjected to EDTA, Ca(II), temperature or pH shocks. The excitation-emission matrix (EEM) fluorescence spectroscopy and fast-Fourier (FT-IR) analysis showed that Hg(II) and Sb(V) principally interacted with polysaccharides and protein-like compounds in the EPS, respectively. The EPS-Hg complex presents a time bomb that may release high levels of Hg(II) in short time period under environmental shocks. Copyright © 2012 Elsevier Ltd. All rights reserved.

Complexity Analysis and Algorithms for Optimal Resource Allocation in Wireless Networks

DTIC Science & Technology

2012-09-01

independent orthogonal signaling such as OFDM . The general formulation will exploit the concept of ‘interference alignment’ which is known to provide...substantial rate gain over OFDM signalling for general interference channels. We have successfully analyzed the complexity to characterize the optimal...categories: PaperReceived Gennady Lyubeznik, Zhi-Quan Luo, Meisam Razaviyayn. On the degrees of freedom achievable through interference alignment in a MIMO

Water-soluble loratadine inclusion complex: analytical control of the preparation by microwave irradiation.

PubMed

Nacsa, A; Ambrus, R; Berkesi, O; Szabó-Révész, P; Aigner, Z

2008-11-04

The majority of active pharmaceutical ingredients are poorly soluble in water. The rate-determining step of absorption is the dissolution of these drugs. Inclusion complexation with cyclodextrin derivatives can lead to improved aqueous solubility and bioavailability of pharmacons due to the formation of co-crystals through hydrogen-bonding between the components. Inclusion complexes of loratadine were prepared by a convenient new method involving microwave irradiation and the products were compared with those of a conventional preparation method. Dissolution studies demonstrated that the solubility and rate of dissolution of loratadine increased in both of the methods used. The interactions between the components were investigated by thermal analysis and Fourier Transform Infrared studies. The microwave treatment did not cause any chemical changes in the loratadine molecule.

Complex character analysis of heart rate variability following brain asphyxia.

PubMed

Cai, Yuanyuan; Qiu, Yihong; Wei, Lan; Zhang, Wei; Hu, Sijun; Smith, Peter R; Crabtree, Vincent P; Tong, Shanbao; Thakor, Nitish V; Zhu, Yisheng

2006-05-01

In the present study Renyi entropy and L-Z complexity were used to characterize heart rate variability (HRV) of rats that were suffered from brain asphyxia and ischemia. Two groups of rats were studied: (a) rats (n=5) injected with NAALADase inhibitor, 2-PMPA, which has been proven neuroprotective in asphyxia injury and (b) control subjects (n=5) without medication. Renyi entropy and L-Z complexity of the R-R intervals (RRI) at different experiment stages were investigated in the two groups. The results show that both measures indicate less injury and better recovery in the drug injection group. The dynamic change of 90 min RRI signal after the asphyxia was investigated. The sudden reduction of the two parameters shows their sensitivity to the asphyxia insult.

Robust hierarchical state-space models reveal diel variation in travel rates of migrating leatherback turtles.

PubMed

Jonsen, Ian D; Myers, Ransom A; James, Michael C

2006-09-01

1. Biological and statistical complexity are features common to most ecological data that hinder our ability to extract meaningful patterns using conventional tools. Recent work on implementing modern statistical methods for analysis of such ecological data has focused primarily on population dynamics but other types of data, such as animal movement pathways obtained from satellite telemetry, can also benefit from the application of modern statistical tools. 2. We develop a robust hierarchical state-space approach for analysis of multiple satellite telemetry pathways obtained via the Argos system. State-space models are time-series methods that allow unobserved states and biological parameters to be estimated from data observed with error. We show that the approach can reveal important patterns in complex, noisy data where conventional methods cannot. 3. Using the largest Atlantic satellite telemetry data set for critically endangered leatherback turtles, we show that the diel pattern in travel rates of these turtles changes over different phases of their migratory cycle. While foraging in northern waters the turtles show similar travel rates during day and night, but on their southward migration to tropical waters travel rates are markedly faster during the day. These patterns are generally consistent with diving data, and may be related to changes in foraging behaviour. Interestingly, individuals that migrate southward to breed generally show higher daytime travel rates than individuals that migrate southward in a non-breeding year. 4. Our approach is extremely flexible and can be applied to many ecological analyses that use complex, sequential data.

Healthcare tariffs for specialist inpatient neurorehabilitation services: rationale and development of a UK casemix and costing methodology.

PubMed

Turner-Stokes, Lynne; Sutch, Stephen; Dredge, Robert

2012-03-01

To describe the rationale and development of a casemix model and costing methodology for tariff development for specialist neurorehabilitation services in the UK. Patients with complex needs incur higher treatment costs. Fair payment should be weighted in proportion to costs of providing treatment, and should allow for variation over time CASEMIX MODEL AND BAND-WEIGHTING: Case complexity is measured by the Rehabilitation Complexity Scale (RCS). Cases are divided into five bands of complexity, based on the total RCS score. The principal determinant of costs in rehabilitation is staff time. Total staff hours/week (estimated from the Northwick Park Nursing and Therapy Dependency Scales) are analysed within each complexity band, through cross-sectional analysis of parallel ratings. A 'band-weighting' factor is derived from the relative proportions of staff time within each of the five bands. Total unit treatment costs are obtained from retrospective analysis of provider hospitals' budget and accounting statements. Mean bed-day costs (total unit cost/occupied bed days) are divided broadly into 'variable' and 'non-variable' components. In the weighted costing model, the band-weighting factor is applied to the variable portion of the bed-day cost to derive a banded cost, and thence a set of cost-multipliers. Preliminary data from one unit are presented to illustrate how this weighted costing model will be applied to derive a multilevel banded payment model, based on serial complexity ratings, to allow for change over time.

Hypothesis testing for the validation of the kinetic spectrophotometric methods for the determination of lansoprazole in bulk and drug formulations via Fe(III) and Zn(II) chelates.

PubMed

Rahman, Nafisur; Kashif, Mohammad

2010-03-01

Point and interval hypothesis tests performed to validate two simple and economical, kinetic spectrophotometric methods for the assay of lansoprazole are described. The methods are based on the formation of chelate complex of the drug with Fe(III) and Zn(II). The reaction is followed spectrophotometrically by measuring the rate of change of absorbance of coloured chelates of the drug with Fe(III) and Zn(II) at 445 and 510 nm, respectively. The stoichiometric ratio of lansoprazole to Fe(III) and Zn(II) complexes were found to be 1:1 and 2:1, respectively. The initial-rate and fixed-time methods are adopted for determination of drug concentrations. The calibration graphs are linear in the range 50-200 µg ml⁻¹ (initial-rate method), 20-180 µg ml⁻¹ (fixed-time method) for lansoprazole-Fe(III) complex and 120-300 (initial-rate method), and 90-210 µg ml⁻¹ (fixed-time method) for lansoprazole-Zn(II) complex. The inter-day and intra-day precision data showed good accuracy and precision of the proposed procedure for analysis of lansoprazole. The point and interval hypothesis tests indicate that the proposed procedures are not biased. Copyright © 2010 John Wiley & Sons, Ltd.

The study of RMB exchange rate complex networks based on fluctuation mode

NASA Astrophysics Data System (ADS)

Yao, Can-Zhong; Lin, Ji-Nan; Zheng, Xu-Zhou; Liu, Xiao-Feng

2015-10-01

In the paper, we research on the characteristics of RMB exchange rate time series fluctuation with methods of symbolization and coarse gaining. First, based on fluctuation features of RMB exchange rate, we define the first type of fluctuation mode as one specific foreign currency against RMB in four days' fluctuating situations, and the second type as four different foreign currencies against RMB in one day's fluctuating situation. With the transforming method, we construct the unique-currency and multi-currency complex networks. Further, through analyzing the topological features including out-degree, betweenness centrality and clustering coefficient of fluctuation-mode complex networks, we find that the out-degree distribution of both types of fluctuation mode basically follows power-law distributions with exponents between 1 and 2. The further analysis reveals that the out-degree and the clustering coefficient generally obey the approximated negative correlation. With this result, we confirm previous observations showing that the RMB exchange rate exhibits a characteristic of long-range memory. Finally, we analyze the most probable transmission route of fluctuation modes, and provide probability prediction matrix. The transmission route for RMB exchange rate fluctuation modes exhibits the characteristics of partially closed loop, repeat and reversibility, which lays a solid foundation for predicting RMB exchange rate fluctuation patterns with large volume of data.

Revisiting Rossion and Pourtois with new ratings for automated complexity, familiarity, beauty, and encounter.

PubMed

Forsythe, Alex; Street, Nichola; Helmy, Mai

2017-08-01

Differences between norm ratings collected when participants are asked to consider more than one picture characteristic are contrasted with the traditional methodological approaches of collecting ratings separately for image constructs. We present data that suggest that reporting normative data, based on methodological procedures that ask participants to consider multiple image constructs simultaneously, could potentially confounded norm data. We provide data for two new image constructs, beauty and the extent to which participants encountered the stimuli in their everyday lives. Analysis of this data suggests that familiarity and encounter are tapping different image constructs. The extent to which an observer encounters an object predicts human judgments of visual complexity. Encountering an image was also found to be an important predictor of beauty, but familiarity with that image was not. Taken together, these results suggest that continuing to collect complexity measures from human judgments is a pointless exercise. Automated measures are more reliable and valid measures, which are demonstrated here as predicting human preferences.

Recurrence-plot-based measures of complexity and their application to heart-rate-variability data.

PubMed

Marwan, Norbert; Wessel, Niels; Meyerfeldt, Udo; Schirdewan, Alexander; Kurths, Jürgen

2002-08-01

The knowledge of transitions between regular, laminar or chaotic behaviors is essential to understand the underlying mechanisms behind complex systems. While several linear approaches are often insufficient to describe such processes, there are several nonlinear methods that, however, require rather long time observations. To overcome these difficulties, we propose measures of complexity based on vertical structures in recurrence plots and apply them to the logistic map as well as to heart-rate-variability data. For the logistic map these measures enable us not only to detect transitions between chaotic and periodic states, but also to identify laminar states, i.e., chaos-chaos transitions. The traditional recurrence quantification analysis fails to detect the latter transitions. Applying our measures to the heart-rate-variability data, we are able to detect and quantify the laminar phases before a life-threatening cardiac arrhythmia occurs thereby facilitating a prediction of such an event. Our findings could be of importance for the therapy of malignant cardiac arrhythmias.

Accuracy of pedicle screw insertion by AIRO® intraoperative CT in complex spinal deformity assessed by a new classification based on technical complexity of screw insertion.

PubMed

Rajasekaran, S; Bhushan, Manindra; Aiyer, Siddharth; Kanna, Rishi; Shetty, Ajoy Prasad

2018-01-09

To develop a classification based on the technical complexity encountered during pedicle screw insertion and to evaluate the performance of AIRO ® CT navigation system based on this classification, in the clinical scenario of complex spinal deformity. 31 complex spinal deformity correction surgeries were prospectively analyzed for performance of AIRO ® mobile CT-based navigation system. Pedicles were classified according to complexity of insertion into five types. Analysis was performed to estimate the accuracy of screw placement and time for screw insertion. Breach greater than 2 mm was considered for analysis. 452 pedicle screws were inserted (T1-T6: 116; T7-T12: 171; L1-S1: 165). The average Cobb angle was 68.3° (range 60°-104°). We had 242 grade 2 pedicles, 133 grade 3, and 77 grade 4, and 44 pedicles were unfit for pedicle screw insertion. We noted 27 pedicle screw breach (medial: 10; lateral: 16; anterior: 1). Among lateral breach (n = 16), ten screws were planned for in-out-in pedicle screw insertion. Among lateral breach (n = 16), ten screws were planned for in-out-in pedicle screw insertion. Average screw insertion time was 1.76 ± 0.89 min. After accounting for planned breach, the effective breach rate was 3.8% resulting in 96.2% accuracy for pedicle screw placement. This classification helps compare the accuracy of screw insertion in range of conditions by considering the complexity of screw insertion. Considering the clinical scenario of complex pedicle anatomy in spinal deformity AIRO ® navigation showed an excellent accuracy rate of 96.2%.

Examination of Factors that Influence the Operation Income and Expenditure Balance Difference Rate of 20 Educational Foundation Universities.

PubMed

Nakajima, Hisato; Yano, Kouya; Nagasawa, Kaoko; Katou, Satoka; Yokota, Kuninobu

2017-01-01

The objective of this study is to examine the factors that influence the operation income and expenditure balance ratio of school corporations running university hospitals by multiple regression analysis. 1. We conducted cluster analysis of the financial ratio and classified the school corporations into those running colleges and universities.2. We conducted multiple regression analysis using the operation income and expenditure balance ratio of the colleges as the variables and the Diagnosis Procedure Combination data as the explaining variables.3. The predictive expression was used for multiple regression analysis. 1. The school corporations were divided into those running universities (7), colleges (20) and others. The medical income ratio and the debt ratio were high and the student payment ratio was low in the colleges.2. The numbers of emergency care hospitalizations, operations, radiation therapies, and ambulance conveyances, and the complexity index had a positive influence on the operation income and expenditure balance ratio. On the other hand, the number of general anesthesia procedures, the cover rate index, and the emergency care index had a negative influence.3. The predictive expression was as follows.Operation income and expenditure balance ratio = 0.027 × number of emergency care hospitalizations + 0.005 × number of operations + 0.019 × number of radiation therapies + 0.007 × number of ambulance conveyances - 0.003 × number of general anesthesia procedures + 648.344 × complexity index - 5877.210 × cover rate index - 2746.415 × emergency care index - 38.647Conclusion: In colleges, the number of emergency care hospitalizations, the number of operations, the number of radiation therapies, and the number of ambulance conveyances and the complexity index were factors for gaining ordinary profit.

The Kinetic Mechanism of Phenylalanine Hydroxylase: Intrinsic Binding and Rate Constants from Single Turnover Experiments†

PubMed Central

Roberts, Kenneth M.; Pavon, Jorge Alex; Fitzpatrick, Paul F.

2013-01-01

Phenylalanine hydroxylase (PheH) catalyzes the key step in the catabolism of dietary phenylalanine, its hydroxylation to tyrosine using tetrahydrobiopterin (BH4) and O2. A complete kinetic mechanism for PheH was determined by global analysis of single turnover data in the reaction of PheHΔ117, a truncated form of the enzyme lacking the N-terminal regulatory domain. Formation of the productive PheHΔ117-BH4-phenylalanine complex begins with the rapid binding of BH4 (Kd = 65 µM). Subsequent addition of phenylalanine to the binary complex to form the productive ternary complex (Kd = 130 µM) is approximately ten-fold slower. Both substrates can also bind to the free enzyme to form inhibitory binary complexes. O2 rapidly binds to the productive ternary complex; this is followed by formation of an unidentified intermediate, detectable as a decrease in absorbance at 340 nm, with a rate constant of 140 s−1. Formation of the 4a-hydroxypterin and Fe(IV)O intermediates is ten-fold slower and is followed by the rapid hydroxylation of the amino acid. Product release is the rate-determining step and largely determines kcat. Similar reactions using 6-methyltetrahydropterin indicate a preference for the physiological pterin during hydroxylation. PMID:23327364

[Indices of pigment formation in complex cytomorphological research on human pigmented skin neoplasms].

PubMed

Naleskina, L A

1985-01-01

Analysis of the topography peculiarities and distribution of oxidized melanine and its precursors (DOPA-oxide activity and catecholamine) in pigment nevuses and malignant melanomas of skin shows that the studied peculiarities are a complex of intersupplementary markers of melanine formation, correlate with the quality and the degree of proliferative process expression in tumours of this genesis and may be used for their malignancy rating.

Bidirectional selection between two classes in complex social networks.

PubMed

Zhou, Bin; He, Zhe; Jiang, Luo-Luo; Wang, Nian-Xin; Wang, Bing-Hong

2014-12-19

The bidirectional selection between two classes widely emerges in various social lives, such as commercial trading and mate choosing. Until now, the discussions on bidirectional selection in structured human society are quite limited. We demonstrated theoretically that the rate of successfully matching is affected greatly by individuals' neighborhoods in social networks, regardless of the type of networks. Furthermore, it is found that the high average degree of networks contributes to increasing rates of successful matches. The matching performance in different types of networks has been quantitatively investigated, revealing that the small-world networks reinforces the matching rate more than scale-free networks at given average degree. In addition, our analysis is consistent with the modeling result, which provides the theoretical understanding of underlying mechanisms of matching in complex networks.

Including Thermal Fluctuations in Actomyosin Stable States Increases the Predicted Force per Motor and Macroscopic Efficiency in Muscle Modelling

PubMed Central

2016-01-01

Muscle contractions are generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. To simulate actomyosin complex stable states, mathematical models usually define an energy landscape with a corresponding number of wells. The jumps between these wells are defined through rate constants. Almost all previous models assign these wells an infinite sharpness by imposing a relatively simple expression for the detailed balance, i.e., the ratio of the rate constants depends exponentially on the sole myosin elastic energy. Physically, this assumption corresponds to neglecting thermal fluctuations in the actomyosin complex stable states. By comparing three mathematical models, we examine the extent to which this hypothesis affects muscle model predictions at the single cross-bridge, single fiber, and organ levels in a ceteris paribus analysis. We show that including fluctuations in stable states allows the lever arm of the myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the infinitely sharp minima case is characterized by fewer jumps between states. Moreover, the analysis predicts that thermal fluctuations enable a more efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges. PMID:27626630

Numerical Approximation of Elasticity Tensor Associated With Green-Naghdi Rate.

PubMed

Liu, Haofei; Sun, Wei

2017-08-01

Objective stress rates are often used in commercial finite element (FE) programs. However, deriving a consistent tangent modulus tensor (also known as elasticity tensor or material Jacobian) associated with the objective stress rates is challenging when complex material models are utilized. In this paper, an approximation method for the tangent modulus tensor associated with the Green-Naghdi rate of the Kirchhoff stress is employed to simplify the evaluation process. The effectiveness of the approach is demonstrated through the implementation of two user-defined fiber-reinforced hyperelastic material models. Comparisons between the approximation method and the closed-form analytical method demonstrate that the former can simplify the material Jacobian evaluation with satisfactory accuracy while retaining its computational efficiency. Moreover, since the approximation method is independent of material models, it can facilitate the implementation of complex material models in FE analysis using shell/membrane elements in abaqus.

A Simple Approach to Evaluate the Kinetic Rate Constant for ATP Synthesis in Resting Human Skeletal Muscle at 7 T

PubMed Central

Ren, Jimin; Sherry, A. Dean; Malloy, Craig R.

2015-01-01

Inversion transfer (IT) is a well-established technique with multiple attractive features for analysis of kinetics. However, its application in measurement of ATP synthesis rate in vivo has lagged behind the more common ST techniques. One well-recognized issue with IT is the complexity of data analysis in comparison to much simpler analysis by ST. This complexity arises, in part, because the γ-ATP spin is involved in multiple chemical reactions and magnetization exchanges, whereas Pi is involved in a single reaction, Pi → γ-ATP. By considering the reactions involving γ-ATP only as a lumped constant, the rate constant for the reaction of physiological interest, kPi→γATP, can be determined. Here, we present a new IT data analysis method to evaluate kPi→γATP using data collected from resting human skeletal muscle at 7T. The method is based on the basic Bloch-McConnell equation, which relates kPi→γATP with ṁPi, the rate of Pi magnetization change. The kPi→γATP value is accessed from ṁPi data by more familiar linear correlation approaches. For a group of human subjects (n = 15), the kPi→γATP value derived for resting calf muscle was 0.066 ± 0.017 s−1, in agreement with literature reported values. In this study we also explored possible time-saving strategies to speed up data acquisition for kPi→γATP evaluation using simulations. The analysis indicates that it is feasible to carry out a 31P inversion transfer experiment in ~10 minutes or shorter at 7T with reasonable outcome in kPi→γATP variance for measurement of ATP synthesis in resting human skeletal muscle. We believe that this new IT data analysis approach will facilitate the wide acceptance of IT to evaluate ATP synthesis rate in vivo. PMID:25943328

Pharmacokinetic Steady-States Highlight Interesting Target-Mediated Disposition Properties.

PubMed

Gabrielsson, Johan; Peletier, Lambertus A

2017-05-01

In this paper, we derive explicit expressions for the concentrations of ligand L, target R and ligand-target complex RL at steady state for the classical model describing target-mediated drug disposition, in the presence of a constant-rate infusion of ligand. We demonstrate that graphing the steady-state values of ligand, target and ligand-target complex, we obtain striking and often singular patterns, which yield a great deal of insight and understanding about the underlying processes. Deriving explicit expressions for the dependence of L, R and RL on the infusion rate, and displaying graphs of the relations between L, R and RL, we give qualitative and quantitive information for the experimentalist about the processes involved. Understanding target turnover is pivotal for optimising these processes when target-mediated drug disposition (TMDD) prevails. By a combination of mathematical analysis and simulations, we also show that the evolution of the three concentration profiles towards their respective steady-states can be quite complex, especially for lower infusion rates. We also show how parameter estimates obtained from iv bolus studies can be used to derive steady-state concentrations of ligand, target and complex. The latter may serve as a template for future experimental designs.

Weighing up the weighted case mix tool (WCMT): a psychometric investigation using confirmatory factor analysis.

PubMed

Duane, B G; Humphris, G; Richards, D; Okeefe, E J; Gordon, K; Freeman, R

2014-12-01

To assess the use of the WCMT in two Scottish health boards and to consider the impact of simplifying the tool to improve efficient use. A retrospective analysis of routine WCMT data (47,276 cases). Public Dental Service (PDS) within NHS Lothian and Highland. The WCMT consists of six criteria. Each criterion is measured independently on a four-point scale to assess patient complexity and the dental care for the disabled/impaired patient. Psychometric analyses on the data-set were conducted. Conventional internal consistency coefficients were calculated. Latent variable modelling was performed to assess the 'fit' of the raw data to a pre-specified measurement model. A Confirmatory Factor Analysis (CFA) was used to test three potential changes to the existing WCMT that included, the removal of the oral risk factor question, the removal of original weightings for scoring the Tool, and collapsing the 4-point rating scale to three categories. The removal of the oral risk factor question had little impact on the reliability of the proposed simplified CMT to discriminate between levels of patient complexity. The removal of weighting and collapsing each item's rating scale to three categories had limited impact on reliability of the revised tool. The CFA analysis provided strong evidence that a new, proposed simplified Case Mix Tool (sCMT) would operate closely to the pre-specified measurement model (the WMCT). A modified sCMT can demonstrate, without reducing reliability, a useful measure of the complexity of patient care. The proposed sCMT may be implemented within primary care dentistry to record patient complexity as part of an oral health assessment.

Kinetics of the substitution of dehydroacetic acid in tris (dehydroacetato) Fe(III) complex by 8-hydroxyquinoline, di- and tetra-hydroxyquinone

NASA Astrophysics Data System (ADS)

Fouad, D. M.; Ismail, N. M.; El-Gahami, M. A.; Ibrahim, S. A.

2007-06-01

The ligand substitution reactions of dehydroacetic acid (Hdha) in [Fe(dha) 3] with second ligand such as 8-hydroxyquinoline (Hquin), 1,4-dihydroxyanthraquinone (H 2dhaq) and 1,4,5,8-tetra-hydroxyanthraquinone (H 4thaq) were investigated spectrophotometrically by in low polarity solvents like benzene, chloroform and dichloromethane. It is deduced that the substitution reaction takes place through one successive step. The reaction was performed at four different temperatures (5-25) °C, and it exhibits a first order dependence on the concentration of the starting complex. The observed rate constant depends on the concentration of both leaving and entering ligands. The evaluation of the kinetic data gives activation parameters which support an associative mechanism in the transition states and the higher rate of substitution of the dha in Fe(dha) 3 complex is due to entropy effect. The solid complexes were synthesized and characterized by elemental analysis, IR and UV-vis spectral techniques.

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.

Chemokinetic accumulation of human neutrophils on immune complex-coated substrata: analysis at a boundary

PubMed Central

1984-01-01

The locomotory behavior of human blood neutrophil leukocytes was studied at a boundary between two surfaces with different chemokinetic properties. This was achieved by time-lapse cinematography of neutrophils moving on coverslips coated with BSA, then part-coated with immune complexes by adding anti-BSA IgG with a straight-line boundary between the BSA and the immune complexes. Cell locomotion was filmed in microscopic fields bisected by the boundary, and kinetic behavior was assessed by comparing speed (orthokinesis), turning behavior (klinokinesis), and the rate of diffusion of the cells on each side of the boundary, using a recently described mathematical analysis of kinesis. In the absence of serum or complement, the proportion of motile cells and their speed and rate of diffusion were greater on BSA than on antiBSA, but there was no consistent difference in turning behavior between cells on the two surfaces. The immune complexes were therefore negatively chemokinetic in comparison with BSA, and this resulted from a negative orthokinesis with little or no contribution from klinokinesis. As would be predicted theoretically, this resulted in gradual accumulation of cells on the immune complexes even in the absence of a chemotactic factor. In further studies, a parallel plate flow chamber was used to show that, under conditions of flow, neutrophils accumulated much more rapidly on a surface coated with BSA- anti-BSA than on BSA alone. Moreover, neutrophils on immune complex- coated surfaces lost their ability to form rosettes with IgG-coated erythrocytes. This suggests that neutrophils on immune complex-coated surfaces redistribute their Fc receptors (RFc gamma) to the under surface, and that the lowered speed of locomotion is due to tethering of neutrophils by substratum-bound IgG-Fc. PMID:6490719

Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons.

PubMed

Isaacman, Gabriel; Chan, Arthur W H; Nah, Theodora; Worton, David R; Ruehl, Chris R; Wilson, Kevin R; Goldstein, Allen H

2012-10-02

Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using recently developed soft ionization gas chromatography techniques. Nucleated motor oil particles are oxidized in a flow tube reactor to investigate the relative reaction rates of observed hydrocarbon classes: alkanes, cycloalkanes, bicycloalkanes, tricycloalkanes, and steranes. Oxidation of hydrocarbons in a complex aerosol is found to be efficient, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ∼20% per nonaromatic ring present. These differences in rates are expected to alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Due to this expected shift toward ring-opening reactions heterogeneous oxidation of the unreacted hydrocarbon mixture is less likely to proceed through fragmentation pathways in more oxidized particles. Based on the observed oxidation-induced changes in composition, isomer-resolved analysis has potential utility for determining the photochemical age of atmospheric particulate matter with respect to heterogeneous oxidation.

Classical technical analysis of Latin American market indices. Correlations in Latin American Currencies (ARS, CLP, MXP) exchange rates with respect to DEM, GBP, JPY and USD

NASA Astrophysics Data System (ADS)

Ausloos, M.; Ivanova, K.

2004-06-01

The classical technical analysis methods of financial time series based on the moving average and momentum is recalled. Illustrations use the IBM share price and Latin American (Argentinian MerVal, Brazilian Bovespa and Mexican IPC) market indices. We have also searched for scaling ranges and exponents in exchange rates between Latin American currencies ($ARS$, $CLP$, $MXP$) and other major currencies $DEM$, $GBP$, $JPY$, $USD$, and $SDR$s. We have sorted out correlations and anticorrelations of such exchange rates with respect to $DEM$, $GBP$, $JPY$ and $USD$. They indicate a very complex or speculative behavior.

Identification of Anisomerous Motor Imagery EEG Signals Based on Complex Algorithms

PubMed Central

Zhang, Zhiwen; Duan, Feng; Zhou, Xin; Meng, Zixuan

2017-01-01

Motor imagery (MI) electroencephalograph (EEG) signals are widely applied in brain-computer interface (BCI). However, classified MI states are limited, and their classification accuracy rates are low because of the characteristics of nonlinearity and nonstationarity. This study proposes a novel MI pattern recognition system that is based on complex algorithms for classifying MI EEG signals. In electrooculogram (EOG) artifact preprocessing, band-pass filtering is performed to obtain the frequency band of MI-related signals, and then, canonical correlation analysis (CCA) combined with wavelet threshold denoising (WTD) is used for EOG artifact preprocessing. We propose a regularized common spatial pattern (R-CSP) algorithm for EEG feature extraction by incorporating the principle of generic learning. A new classifier combining the K-nearest neighbor (KNN) and support vector machine (SVM) approaches is used to classify four anisomerous states, namely, imaginary movements with the left hand, right foot, and right shoulder and the resting state. The highest classification accuracy rate is 92.5%, and the average classification accuracy rate is 87%. The proposed complex algorithm identification method can significantly improve the identification rate of the minority samples and the overall classification performance. PMID:28874909

Are Complexity Metrics Reliable in Assessing HRV Control in Obese Patients During Sleep?

PubMed

Cabiddu, Ramona; Trimer, Renata; Borghi-Silva, Audrey; Migliorini, Matteo; Mendes, Renata G; Oliveira, Antonio D; Costa, Fernando S M; Bianchi, Anna M

2015-01-01

Obesity is associated with cardiovascular mortality. Linear methods, including time domain and frequency domain analysis, are normally applied on the heart rate variability (HRV) signal to investigate autonomic cardiovascular control, whose imbalance might promote cardiovascular disease in these patients. However, given the cardiac activity non-linearities, non-linear methods might provide better insight. HRV complexity was hereby analyzed during wakefulness and different sleep stages in healthy and obese subjects. Given the short duration of each sleep stage, complexity measures, normally extracted from long-period signals, needed be calculated on short-term signals. Sample entropy, Lempel-Ziv complexity and detrended fluctuation analysis were evaluated and results showed no significant differences among the values calculated over ten-minute signals and longer durations, confirming the reliability of such analysis when performed on short-term signals. Complexity parameters were extracted from ten-minute signal portions selected during wakefulness and different sleep stages on HRV signals obtained from eighteen obese patients and twenty controls. The obese group presented significantly reduced complexity during light and deep sleep, suggesting a deficiency in the control mechanisms integration during these sleep stages. To our knowledge, this study reports for the first time on how the HRV complexity changes in obesity during wakefulness and sleep. Further investigation is needed to quantify altered HRV impact on cardiovascular mortality in obesity.

Are Complexity Metrics Reliable in Assessing HRV Control in Obese Patients During Sleep?

PubMed Central

Cabiddu, Ramona; Trimer, Renata; Borghi-Silva, Audrey; Migliorini, Matteo; Mendes, Renata G.; Oliveira Jr., Antonio D.; Costa, Fernando S. M.; Bianchi, Anna M.

2015-01-01

Obesity is associated with cardiovascular mortality. Linear methods, including time domain and frequency domain analysis, are normally applied on the heart rate variability (HRV) signal to investigate autonomic cardiovascular control, whose imbalance might promote cardiovascular disease in these patients. However, given the cardiac activity non-linearities, non-linear methods might provide better insight. HRV complexity was hereby analyzed during wakefulness and different sleep stages in healthy and obese subjects. Given the short duration of each sleep stage, complexity measures, normally extracted from long-period signals, needed be calculated on short-term signals. Sample entropy, Lempel-Ziv complexity and detrended fluctuation analysis were evaluated and results showed no significant differences among the values calculated over ten-minute signals and longer durations, confirming the reliability of such analysis when performed on short-term signals. Complexity parameters were extracted from ten-minute signal portions selected during wakefulness and different sleep stages on HRV signals obtained from eighteen obese patients and twenty controls. The obese group presented significantly reduced complexity during light and deep sleep, suggesting a deficiency in the control mechanisms integration during these sleep stages. To our knowledge, this study reports for the first time on how the HRV complexity changes in obesity during wakefulness and sleep. Further investigation is needed to quantify altered HRV impact on cardiovascular mortality in obesity. PMID:25893856

Clinical features and treatment outcome of non-small cell lung cancer (NSCLC) patients with uncommon or complex epidermal growth factor receptor (EGFR) mutations

PubMed Central

Fassan, Matteo; Indraccolo, Stefano; Calabrese, Fiorella; Favaretto, Adolfo; Bonanno, Laura; Polo, Valentina; Zago, Giulia; Lunardi, Francesca; Attili, Ilaria; Pavan, Alberto; Rugge, Massimo; Guarneri, Valentina; Conte, PierFranco; Pasello, Giulia

2017-01-01

Introduction Tyrosine-kinase inhibitors (TKIs) represent the best treatment for advanced non-small cell lung cancer (NSCLC) with common exon 19 deletion or exon 21 epidermal growth factor receptor mutation (EGFRm). This is an observational study investigating epidemiology, clinical features and treatment outcome of NSCLC cases harbouring rare/complex EGFRm. Results Among 764 non-squamous NSCLC cases with known EGFRm status, 26(3.4%) harboured rare/complex EGFRm. Patients receiving first-line TKIs (N = 17) achieved median Progression Free Survival (PFS) and Overall Survival (OS) of 53 (IC 95%, 2–105) and 84 (CI 95%, 27–141) weeks respectively, without significant covariate impact. Response Rate and Disease Control Rate (DCR) were 47% and 65%, respectively. Uncommon exon 19 mutations achieved longer OS and PFS and higher DCR compared with exon 18 and 20 mutations. No additional gene mutation was discovered by MassARRAY analysis. TKIs were globally well tolerated. Materials and methods A retrospective review of advanced non-squamous NSCLC harbouring rare/complex EGFRm referred to our Center between 2010 and 2015 was performed. Additional molecular pathways disregulation was explored in selected cases, through MassARRAY analysis. Conclusions Peculiar clinical features and lower TKIs sensitivity of uncommon/complex compared with common EGFRm were shown. Exon 19 EGFRm achieved the best TKIs treatment outcome, while the optimal treatment of exon 18 and 20 mutations should be further clarified. PMID:28427238

An analytical platform for mass spectrometry-based identification and chemical analysis of RNA in ribonucleoprotein complexes.

PubMed

Taoka, Masato; Yamauchi, Yoshio; Nobe, Yuko; Masaki, Shunpei; Nakayama, Hiroshi; Ishikawa, Hideaki; Takahashi, Nobuhiro; Isobe, Toshiaki

2009-11-01

We describe here a mass spectrometry (MS)-based analytical platform of RNA, which combines direct nano-flow reversed-phase liquid chromatography (RPLC) on a spray tip column and a high-resolution LTQ-Orbitrap mass spectrometer. Operating RPLC under a very low flow rate with volatile solvents and MS in the negative mode, we could estimate highly accurate mass values sufficient to predict the nucleotide composition of a approximately 21-nucleotide small interfering RNA, detect post-transcriptional modifications in yeast tRNA, and perform collision-induced dissociation/tandem MS-based structural analysis of nucleolytic fragments of RNA at a sub-femtomole level. Importantly, the method allowed the identification and chemical analysis of small RNAs in ribonucleoprotein (RNP) complex, such as the pre-spliceosomal RNP complex, which was pulled down from cultured cells with a tagged protein cofactor as bait. We have recently developed a unique genome-oriented database search engine, Ariadne, which allows tandem MS-based identification of RNAs in biological samples. Thus, the method presented here has broad potential for automated analysis of RNA; it complements conventional molecular biology-based techniques and is particularly suited for simultaneous analysis of the composition, structure, interaction, and dynamics of RNA and protein components in various cellular RNP complexes.

Analysis of Ligand-Receptor Association and Intermediate Transfer Rates in Multienzyme Nanostructures with All-Atom Brownian Dynamics Simulations.

PubMed

Roberts, Christopher C; Chang, Chia-En A

2016-08-25

We present the second-generation GeomBD Brownian dynamics software for determining interenzyme intermediate transfer rates and substrate association rates in biomolecular complexes. Substrate and intermediate association rates for a series of enzymes or biomolecules can be compared between the freely diffusing disorganized configuration and various colocalized or complexed arrangements for kinetic investigation of enhanced intermediate transfer. In addition, enzyme engineering techniques, such as synthetic protein conjugation, can be computationally modeled and analyzed to better understand changes in substrate association relative to native enzymes. Tools are provided to determine nonspecific ligand-receptor association residence times, and to visualize common sites of nonspecific association of substrates on receptor surfaces. To demonstrate features of the software, interenzyme intermediate substrate transfer rate constants are calculated and compared for all-atom models of DNA origami scaffold-bound bienzyme systems of glucose oxidase and horseradish peroxidase. Also, a DNA conjugated horseradish peroxidase enzyme was analyzed for its propensity to increase substrate association rates and substrate local residence times relative to the unmodified enzyme. We also demonstrate the rapid determination and visualization of common sites of nonspecific ligand-receptor association by using HIV-1 protease and an inhibitor, XK263. GeomBD2 accelerates simulations by precomputing van der Waals potential energy grids and electrostatic potential grid maps, and has a flexible and extensible support for all-atom and coarse-grained force fields. Simulation software is written in C++ and utilizes modern parallelization techniques for potential grid preparation and Brownian dynamics simulation processes. Analysis scripts, written in the Python scripting language, are provided for quantitative simulation analysis. GeomBD2 is applicable to the fields of biophysics, bioengineering, and enzymology in both predictive and explanatory roles.

Modeling of Mitochondria Bioenergetics Using a Composable Chemiosmotic Energy Transduction Rate Law: Theory and Experimental Validation

PubMed Central

Chang, Ivan; Heiske, Margit; Letellier, Thierry; Wallace, Douglas; Baldi, Pierre

2011-01-01

Mitochondrial bioenergetic processes are central to the production of cellular energy, and a decrease in the expression or activity of enzyme complexes responsible for these processes can result in energetic deficit that correlates with many metabolic diseases and aging. Unfortunately, existing computational models of mitochondrial bioenergetics either lack relevant kinetic descriptions of the enzyme complexes, or incorporate mechanisms too specific to a particular mitochondrial system and are thus incapable of capturing the heterogeneity associated with these complexes across different systems and system states. Here we introduce a new composable rate equation, the chemiosmotic rate law, that expresses the flux of a prototypical energy transduction complex as a function of: the saturation kinetics of the electron donor and acceptor substrates; the redox transfer potential between the complex and the substrates; and the steady-state thermodynamic force-to-flux relationship of the overall electro-chemical reaction. Modeling of bioenergetics with this rate law has several advantages: (1) it minimizes the use of arbitrary free parameters while featuring biochemically relevant parameters that can be obtained through progress curves of common enzyme kinetics protocols; (2) it is modular and can adapt to various enzyme complex arrangements for both in vivo and in vitro systems via transformation of its rate and equilibrium constants; (3) it provides a clear association between the sensitivity of the parameters of the individual complexes and the sensitivity of the system's steady-state. To validate our approach, we conduct in vitro measurements of ETC complex I, III, and IV activities using rat heart homogenates, and construct an estimation procedure for the parameter values directly from these measurements. In addition, we show the theoretical connections of our approach to the existing models, and compare the predictive accuracy of the rate law with our experimentally fitted parameters to those of existing models. Finally, we present a complete perturbation study of these parameters to reveal how they can significantly and differentially influence global flux and operational thresholds, suggesting that this modeling approach could help enable the comparative analysis of mitochondria from different systems and pathological states. The procedures and results are available in Mathematica notebooks at http://www.igb.uci.edu/tools/sb/mitochondria-modeling.html. PMID:21931590

Modeling of mitochondria bioenergetics using a composable chemiosmotic energy transduction rate law: theory and experimental validation.

PubMed

Chang, Ivan; Heiske, Margit; Letellier, Thierry; Wallace, Douglas; Baldi, Pierre

2011-01-01

Mitochondrial bioenergetic processes are central to the production of cellular energy, and a decrease in the expression or activity of enzyme complexes responsible for these processes can result in energetic deficit that correlates with many metabolic diseases and aging. Unfortunately, existing computational models of mitochondrial bioenergetics either lack relevant kinetic descriptions of the enzyme complexes, or incorporate mechanisms too specific to a particular mitochondrial system and are thus incapable of capturing the heterogeneity associated with these complexes across different systems and system states. Here we introduce a new composable rate equation, the chemiosmotic rate law, that expresses the flux of a prototypical energy transduction complex as a function of: the saturation kinetics of the electron donor and acceptor substrates; the redox transfer potential between the complex and the substrates; and the steady-state thermodynamic force-to-flux relationship of the overall electro-chemical reaction. Modeling of bioenergetics with this rate law has several advantages: (1) it minimizes the use of arbitrary free parameters while featuring biochemically relevant parameters that can be obtained through progress curves of common enzyme kinetics protocols; (2) it is modular and can adapt to various enzyme complex arrangements for both in vivo and in vitro systems via transformation of its rate and equilibrium constants; (3) it provides a clear association between the sensitivity of the parameters of the individual complexes and the sensitivity of the system's steady-state. To validate our approach, we conduct in vitro measurements of ETC complex I, III, and IV activities using rat heart homogenates, and construct an estimation procedure for the parameter values directly from these measurements. In addition, we show the theoretical connections of our approach to the existing models, and compare the predictive accuracy of the rate law with our experimentally fitted parameters to those of existing models. Finally, we present a complete perturbation study of these parameters to reveal how they can significantly and differentially influence global flux and operational thresholds, suggesting that this modeling approach could help enable the comparative analysis of mitochondria from different systems and pathological states. The procedures and results are available in Mathematica notebooks at http://www.igb.uci.edu/tools/sb/mitochondria-modeling.html.

Management, Analysis, and Visualization of Experimental and Observational Data – The Convergence of Data and Computing

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

Bethel, E. Wes; Greenwald, Martin; Kleese van Dam, Kerstin

Scientific user facilities—particle accelerators, telescopes, colliders, supercomputers, light sources, sequencing facilities, and more—operated by the U.S. Department of Energy (DOE) Office of Science (SC) generate ever increasing volumes of data at unprecedented rates from experiments, observations, and simulations. At the same time there is a growing community of experimentalists that require real-time data analysis feedback, to enable them to steer their complex experimental instruments to optimized scientific outcomes and new discoveries. Recent efforts in DOE-SC have focused on articulating the data-centric challenges and opportunities facing these science communities. Key challenges include difficulties coping with data size, rate, and complexity inmore » the context of both real-time and post-experiment data analysis and interpretation. Solutions will require algorithmic and mathematical advances, as well as hardware and software infrastructures that adequately support data-intensive scientific workloads. This paper presents the summary findings of a workshop held by DOE-SC in September 2015, convened to identify the major challenges and the research that is needed to meet those challenges.« less

Management, Analysis, and Visualization of Experimental and Observational Data -- The Convergence of Data and Computing

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

Bethel, E. Wes; Greenwald, Martin; Kleese van Dam, Kersten

Scientific user facilities---particle accelerators, telescopes, colliders, supercomputers, light sources, sequencing facilities, and more---operated by the U.S. Department of Energy (DOE) Office of Science (SC) generate ever increasing volumes of data at unprecedented rates from experiments, observations, and simulations. At the same time there is a growing community of experimentalists that require real-time data analysis feedback, to enable them to steer their complex experimental instruments to optimized scientific outcomes and new discoveries. Recent efforts in DOE-SC have focused on articulating the data-centric challenges and opportunities facing these science communities. Key challenges include difficulties coping with data size, rate, and complexity inmore » the context of both real-time and post-experiment data analysis and interpretation. Solutions will require algorithmic and mathematical advances, as well as hardware and software infrastructures that adequately support data-intensive scientific workloads. This paper presents the summary findings of a workshop held by DOE-SC in September 2015, convened to identify the major challenges and the research that is needed to meet those challenges.« less

Precise calculation of a bond percolation transition and survival rates of nodes in a complex network.

PubMed

Kawamoto, Hirokazu; Takayasu, Hideki; Jensen, Henrik Jeldtoft; Takayasu, Misako

2015-01-01

Through precise numerical analysis, we reveal a new type of universal loopless percolation transition in randomly removed complex networks. As an example of a real-world network, we apply our analysis to a business relation network consisting of approximately 3,000,000 links among 300,000 firms and observe the transition with critical exponents close to the mean-field values taking into account the finite size effect. We focus on the largest cluster at the critical point, and introduce survival probability as a new measure characterizing the robustness of each node. We also discuss the relation between survival probability and k-shell decomposition.

The cytochrome b6f complex at the crossroad of photosynthetic electron transport pathways.

PubMed

Tikhonov, Alexander N

2014-08-01

Regulation of photosynthetic electron transport at the level of the cytochrome b6f complex provides efficient performance of the chloroplast electron transport chain (ETC). In this review, after brief overview of the structural organization of the chloroplast ETC, the consideration of the problem of electron transport control is focused on the plastoquinone (PQ) turnover and its interaction with the b6f complex. The data available show that the rates of plastoquinol (PQH2) formation in PSII and its diffusion to the b6f complex do not limit the overall rate of electron transfer between photosystem II (PSII) and photosystem I (PSI). Analysis of experimental and theoretical data demonstrates that the rate-limiting step in the intersystem chain of electron transport is determined by PQH2 oxidation at the Qo-site of the b6f complex, which is accompanied by the proton release into the thylakoid lumen. The acidification of the lumen causes deceleration of PQH2 oxidation, thus impeding the intersystem electron transport. Two other mechanisms of regulation of the intersystem electron transport have been considered: (i) "state transitions" associated with the light-induced redistribution of solar energy between PSI and PSII, and (ii) redistribution of electron fluxes between alternative pathways (noncyclic electron transport and cyclic electron flow around PSI). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

In vivo quantitative analysis of Talin turnover in response to force

PubMed Central

Hákonardóttir, Guðlaug Katrín; López-Ceballos, Pablo; Herrera-Reyes, Alejandra Donají; Das, Raibatak; Coombs, Daniel; Tanentzapf, Guy

2015-01-01

Cell adhesion to the extracellular matrix (ECM) allows cells to form and maintain three-dimensional tissue architecture. Cell–ECM adhesions are stabilized upon exposure to mechanical force. In this study, we used quantitative imaging and mathematical modeling to gain mechanistic insight into how integrin-based adhesions respond to increased and decreased mechanical forces. A critical means of regulating integrin-based adhesion is provided by modulating the turnover of integrin and its adhesion complex (integrin adhesion complex [IAC]). The turnover of the IAC component Talin, a known mechanosensor, was analyzed using fluorescence recovery after photobleaching. Experiments were carried out in live, intact flies in genetic backgrounds that increased or decreased the force applied on sites of adhesion. This analysis showed that when force is elevated, the rate of assembly of new adhesions increases such that cell–ECM adhesion is stabilized. Moreover, under conditions of decreased force, the overall rate of turnover, but not the proportion of adhesion complex components undergoing turnover, increases. Using point mutations, we identify the key functional domains of Talin that mediate its response to force. Finally, by fitting a mathematical model to the data, we uncover the mechanisms that mediate the stabilization of ECM-based adhesion during development. PMID:26446844

Factors Associated With Emergency Department Visits: A Multistate Analysis of Adult Fee-for-Service Medicaid Beneficiaries.

PubMed

Agarwal, Parul; Bias, Thomas K; Madhavan, Suresh; Sambamoorthi, Nethra; Frisbee, Stephanie; Sambamoorthi, Usha

2016-04-27

The objective of this study was to examine the association of patient- and county-level factors with the emergency department (ED) visits among adult fee-for-service (FFS) Medicaid beneficiaries residing in Maryland, Ohio, and West Virginia. A cross-sectional design using retrospective observational data was implemented. Patient-level data were obtained from 2010 Medicaid Analytic eXtract files. Information on county-level health-care resources was obtained from the Area Health Resource file and County Health Rankings file. In adjusted analyses, the following patient-level factors were associated with higher number of ED visits: African Americans (incidence rate ratios [IRR] = 1.47), Hispanics (IRR = 1.63), polypharmacy (IRR = 1.89), and tobacco use (IRR = 2.23). Patients with complex chronic illness had a higher number of ED visits (IRR = 3.33). The county-level factors associated with ED visits were unemployment rate (IRR = 0.94) and number of urgent care clinics (IRR = 0.96). Patients with complex healthcare needs had a higher number of ED visits as compared to those without complex healthcare needs. The study results provide important baseline context for future policy analysis studies around Medicaid expansion options.

Development of the photosynthetic apparatus of Cunninghamia lanceolata in light and darkness.

PubMed

Xue, Xian; Wang, Qi; Qu, Yanli; Wu, Hongyang; Dong, Fengqin; Cao, Haoyan; Wang, Hou-Ling; Xiao, Jianwei; Shen, Yingbai; Wan, Yinglang

2017-01-01

Here, we compared the development of dark- and light-grown Chinese fir (Cunninghamia lanceolata) cotyledons, which synthesize chlorophyll in the dark, representing a different phenomenon from angiosperm model plants. We determined that the grana lamellar membranes were well developed in both chloroplasts and etiochloroplasts. The accumulation of thylakoid membrane protein complexes was similar between chloroplasts and etiochloroplasts. Measurement of chlorophyll fluorescence parameters indicated that photosystem II (PSII) had low photosynthetic activities, whereas the photosystem I (PSI)-driven cyclic electron flow (CEF) rate exceeded the rate of PSII-mediated photon harvesting in etiochloroplasts. Analysis of the protein contents in etiochloroplasts indicated that the light-harvesting complex II remained mostly in its monomeric conformation. The ferredoxin NADP + oxidoreductase and NADH dehydrogenase-like complexes were relatively abundantly expressed in etiochloroplasts for Chinese fir. Our transcriptome analysis contributes a global expression database for Chinese fir cotyledons, providing background information on the regulatory mechanisms of different genes involved in the development of dark- and light-grown cotyledons. In conclusion, we provide a novel description of the early developmental status of the light-dependent and light-independent photosynthetic apparatuses in gymnosperms. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Existence of species complex largely reduced barcoding success for invasive species of Tephritidae: a case study in Bactrocera spp.

PubMed

Jiang, F; Jin, Q; Liang, L; Zhang, A B; Li, Z H

2014-11-01

Fruit flies in the family Tephritidae are the economically important pests that have many species complexes. DNA barcoding has gradually been verified as an effective tool for identifying species in a wide range of taxonomic groups, and there are several publications on rapid and accurate identification of fruit flies based on this technique; however, comprehensive analyses of large and new taxa for the effectiveness of DNA barcoding for fruit flies identification have been rare. In this study, we evaluated the COI barcode sequences for the diagnosis of fruit flies using 1426 sequences for 73 species of Bactrocera distributed worldwide. Tree-based [neighbour-joining (NJ)]; distance-based, such as Best Match (BM), Best Close Match (BCM) and Minimum Distance (MD); and character-based methods were used to evaluate the barcoding success rates obtained with maintaining the species complex in the data set, treating a species complex as a single taxon unit, and removing the species complex. Our results indicate that the average divergence between species was 14.04% (0.00-25.16%), whereas within a species this was 0.81% (0.00-9.71%); the existence of species complexes largely reduced the barcoding success for Tephritidae, for example relatively low success rates (74.4% based on BM and BCM and 84.8% based on MD) were obtained when the sequences from species complexes were included in the analysis, whereas significantly higher success rates were achieved if the species complexes were treated as a single taxon or removed from the data set - BM (98.9%), BCM (98.5%) and MD (97.5%), or BM (98.1%), BCM (97.4%) and MD (98.2%). © 2014 John Wiley & Sons Ltd.

Backbone dynamics in an intramolecular prolylpeptide-SH3 complex from the diphtheria toxin repressor, DtxR

PubMed Central

Bhattacharya, Nilakshee; Yi, Myunggi; Zhou, Huan-Xiang; Logan, Timothy M.

2008-01-01

Summary The diphtheria toxin repressor contains an SH3-like domain that forms an intramolecular complex with a proline-rich (Pr) peptide segment and stabilizes the inactive state of the repressor. Upon activation of DtxR by transition metals, this intramolecular complex must dissociate as the SH3 domain and Pr segment form different interactions in the active repressor. In this study we investigate the dynamics of this intramolecular complex using backbone amide nuclear spin relaxation rates determined using NMR spectroscopy and molecular dynamics trajectories. The SH3 domain in the unbound and bound states showed typical dynamics in that the secondary structures were fairly ordered with high generalized order parameters and low effective correlation times while residues in the loops connecting β-strands exhibited reduced generalized order parameters and required additional motional terms to adequately model the relaxation rates. Residues forming the Pr segment exhibited low order parameters with internal rotational correlation times on the order of 0.6 – 1 ns. Further analysis showed that the SH3 domain was rich in millisecond timescale motions while the Pr segment was rich in motions on the 100s μs timescale. Molecular dynamics simultations indicated structural rearrangements that may contribute to the observed relaxation rates and, together with the observed relaxation rate data, suggested that the Pr segment exhibits a binding ↔ unbinding equilibrium. The results of this study provide new insights into the nature of the intramolecular complex and provide a better understanding of the biological role of the SH3 domain in regulating DtxR activity. PMID:17976643

Informed decision-making in elective major vascular surgery: analysis of 145 surgeon-patient consultations.

PubMed

Etchells, Edward; Ferrari, Michel; Kiss, Alex; Martyn, Nikki; Zinman, Deborah; Levinson, Wendy

2011-06-01

Prior studies show significant gaps in the informed decision-making process, a central goal of surgical care. These studies have been limited by their focus on low-risk decisions, single visits rather than entire consultations, or both. Our objectives were, first, to rate informed decision-making for major elective vascular surgery based on audiotapes of actual physician-patient conversations and, second, to compare ratings of informed decision-making for first visits to ratings for multiple visits by the same patient over time. We prospectively enrolled patients for whom vascular surgical treatment was a potential option at a tertiary care outpatient vascular surgery clinic. We audio-taped all surgeon-patient conversations, including multiple visits when necessary, until a decision was made. Using an existing method, we evaluated the transcripts for elements of decision-making, including basic elements (e.g., an explanation of the clinical condition), intermediate elements (e.g., risks and benefits) and complex elements (e.g., uncertainty around the decision). We analyzed 145 surgeon-patient consultations. Overall, 45% of consultations contained complex elements, whereas 23% did not contain the basic elements of decision-making. For the 67 consultations that involved multiple visits, ratings were significantly higher when evaluating all visits (50% complex elements) compared with evaluating only the first visit (33% complex elements, p < 0.001.) We found that 45% of consultations contained complex elements, which is higher than prior studies with similar methods. Analyzing decision-making over multiple visits yielded different results than analyzing decision-making for single visits.

Flat plate vs. concentrator solar photovoltaic cells - A manufacturing cost analysis

NASA Technical Reports Server (NTRS)

Granon, L. A.; Coleman, M. G.

1980-01-01

The choice of which photovoltaic system (flat plate or concentrator) to use for utilizing solar cells to generate electricity depends mainly on the cost. A detailed, comparative manufacturing cost analysis of the two types of systems is presented. Several common assumptions, i.e., cell thickness, interest rate, power rate, factory production life, polysilicon cost, and direct labor rate are utilized in this analysis. Process sequences, cost variables, and sensitivity analyses have been studied, and results of the latter show that the most important parameters which determine manufacturing costs are concentration ratio, manufacturing volume, and cell efficiency. The total cost per watt of the flat plate solar cell is $1.45, and that of the concentrator solar cell is $1.85, the higher cost being due to the increased process complexity and material costs.

Kinetics of the reduction of cobalt(III) amine complexes by 1-hydroxy-1-methylethyl radicals

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

Kusaba, K.; Ogino, Hiroshi; Bakac, A.

1989-03-08

In order to better understand the rate constants for the reduction of several cobalt complexes by 1-hydroxy-1-methylene radicals ({sup {sm bullet}}C(CH{sub 3}){sub 2}OH), the reactions of {sup {sm bullet}}(CH{sub 3}){sub 2}OH with several cobalt(III) complexes of bidentate amines have been studied. The Marcus-Hush theory was deemed the most appropriate for analysis of the kinetic data. The correlation between the kinetics of the reduction of the Co(III) amines by C(CH{sub 3}){sub 2}OH and the reduction of the first d-d band for Co(III) complexes is discussed. 21 refs., 2 figs., 1 tab.

Quantitative Assessment of Heart Rate Dynamics during Meditation: An ECG Based Study with Multi-Fractality and Visibility Graph

PubMed Central

Bhaduri, Anirban; Ghosh, Dipak

2016-01-01

The cardiac dynamics during meditation is explored quantitatively with two chaos-based non-linear techniques viz. multi-fractal detrended fluctuation analysis and visibility network analysis techniques. The data used are the instantaneous heart rate (in beats/minute) of subjects performing Kundalini Yoga and Chi meditation from PhysioNet. The results show consistent differences between the quantitative parameters obtained by both the analysis techniques. This indicates an interesting phenomenon of change in the complexity of the cardiac dynamics during meditation supported with quantitative parameters. The results also produce a preliminary evidence that these techniques can be used as a measure of physiological impact on subjects performing meditation. PMID:26909045

Quantitative Assessment of Heart Rate Dynamics during Meditation: An ECG Based Study with Multi-Fractality and Visibility Graph.

PubMed

Bhaduri, Anirban; Ghosh, Dipak

2016-01-01

The cardiac dynamics during meditation is explored quantitatively with two chaos-based non-linear techniques viz. multi-fractal detrended fluctuation analysis and visibility network analysis techniques. The data used are the instantaneous heart rate (in beats/minute) of subjects performing Kundalini Yoga and Chi meditation from PhysioNet. The results show consistent differences between the quantitative parameters obtained by both the analysis techniques. This indicates an interesting phenomenon of change in the complexity of the cardiac dynamics during meditation supported with quantitative parameters. The results also produce a preliminary evidence that these techniques can be used as a measure of physiological impact on subjects performing meditation.

Risk factors in laparoscopic cholecystectomy: a multivariate analysis.

PubMed

Kanakala, Venkatesh; Borowski, David W; Pellen, Michael G C; Dronamraju, Shridhar S; Woodcock, Sean A A; Seymour, Keith; Attwood, Stephen E A; Horgan, Liam F

2011-01-01

Laparoscopic cholecystectomy (LC) is the operation of choice in the treatment of symptomatic gallstone disease. The aim of this study is to identify risk factors for LC, outcomes include operating time, length of stay, conversion rate, morbidity and mortality. All patients undergoing LC between 1998 and 2007 in a single district general hospital. Risk factors were examined using uni- and multivariate analysis. 2117 patients underwent LC, with 1706 (80.6%) patients operated on electively. Male patients were older, had more co-morbidity and more emergency surgery than females. The median post-operative hospital stay was one day, and was positively correlated with the complexity of surgery. Conversion rates were higher in male patients (OR 1.47, p = 0.047) than in females, and increased with co-morbidity. Emergency surgery (OR 1.75, p = 0.005), male gender (OR 1.68, p = 0.005), increasing co-morbidity and complexity of surgery were all positively associated with the incidence of complications (153/2117 [7.2%]), whereas only male gender was significantly associated with mortality (OR 5.71, p = 0.025). Adverse outcome from LC is particularly associated with male gender, but also the patient's co-morbidity, complexity and urgency of surgery. Risk-adjusted outcome analysis is desirable to ensure an informed consent process. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Are we under-utilizing the talents of primary care personnel? A job analytic examination

PubMed Central

Hysong, Sylvia J; Best, Richard G; Moore, Frank I

2007-01-01

Background Primary care staffing decisions are often made unsystematically, potentially leading to increased costs, dissatisfaction, turnover, and reduced quality of care. This article aims to (1) catalogue the domain of primary care tasks, (2) explore the complexity associated with these tasks, and (3) examine how tasks performed by different job titles differ in function and complexity, using Functional Job Analysis to develop a new tool for making evidence-based staffing decisions. Methods Seventy-seven primary care personnel from six US Department of Veterans Affairs (VA) Medical Centers, representing six job titles, participated in two-day focus groups to generate 243 unique task statements describing the content of VA primary care. Certified job analysts rated tasks on ten dimensions representing task complexity, skills, autonomy, and error consequence. Two hundred and twenty-four primary care personnel from the same clinics then completed a survey indicating whether they performed each task. Tasks were catalogued using an adaptation of an existing classification scheme; complexity differences were tested via analysis of variance. Results Objective one: Task statements were categorized into four functions: service delivery (65%), administrative duties (15%), logistic support (9%), and workforce management (11%). Objective two: Consistent with expectations, 80% of tasks received ratings at or below the mid-scale value on all ten scales. Objective three: Service delivery and workforce management tasks received higher ratings on eight of ten scales (multiple functional complexity dimensions, autonomy, human error consequence) than administrative and logistic support tasks. Similarly, tasks performed by more highly trained job titles received higher ratings on six of ten scales than tasks performed by lower trained job titles. Contrary to expectations, the distribution of tasks across functions did not significantly vary by job title. Conclusion Primary care personnel are not being utilized to the extent of their training; most personnel perform many tasks that could reasonably be performed by personnel with less training. Primary care clinics should use evidence-based information to optimize job-person fit, adjusting clinic staff mix and allocation of work across staff to enhance efficiency and effectiveness. PMID:17397534

Automatic QRS complex detection using two-level convolutional neural network.

PubMed

Xiang, Yande; Lin, Zhitao; Meng, Jianyi

2018-01-29

The QRS complex is the most noticeable feature in the electrocardiogram (ECG) signal, therefore, its detection is critical for ECG signal analysis. The existing detection methods largely depend on hand-crafted manual features and parameters, which may introduce significant computational complexity, especially in the transform domains. In addition, fixed features and parameters are not suitable for detecting various kinds of QRS complexes under different circumstances. In this study, based on 1-D convolutional neural network (CNN), an accurate method for QRS complex detection is proposed. The CNN consists of object-level and part-level CNNs for extracting different grained ECG morphological features automatically. All the extracted morphological features are used by multi-layer perceptron (MLP) for QRS complex detection. Additionally, a simple ECG signal preprocessing technique which only contains difference operation in temporal domain is adopted. Based on the MIT-BIH arrhythmia (MIT-BIH-AR) database, the proposed detection method achieves overall sensitivity Sen = 99.77%, positive predictivity rate PPR = 99.91%, and detection error rate DER = 0.32%. In addition, the performance variation is performed according to different signal-to-noise ratio (SNR) values. An automatic QRS detection method using two-level 1-D CNN and simple signal preprocessing technique is proposed for QRS complex detection. Compared with the state-of-the-art QRS complex detection approaches, experimental results show that the proposed method acquires comparable accuracy.

On the application of under-decimated filter banks

NASA Technical Reports Server (NTRS)

Lin, Y.-P.; Vaidyanathan, P. P.

1994-01-01

Maximally decimated filter banks have been extensively studied in the past. A filter bank is said to be under-decimated if the number of channels is more than the decimation ratio in the subbands. A maximally decimated filter bank is well known for its application in subband coding. Another application of maximally decimated filter banks is in block filtering. Convolution through block filtering has the advantages that parallelism is increased and data are processed at a lower rate. However, the computational complexity is comparable to that of direct convolution. More recently, another type of filter bank convolver has been developed. In this scheme, the convolution is performed in the subbands. Quantization and bit allocation of subband signals are based on signal variance, as in subband coding. Consequently, for a fixed rate, the result of convolution is more accurate than is direct convolution. This type of filter bank convolver also enjoys the advantages of block filtering, parallelism, and a lower working rate. Nevertheless, like block filtering, there is no computational saving. In this article, under-decimated systems are introduced to solve the problem. The new system is decimated only by half the number of channels. Two types of filter banks can be used in the under-decimated system: the discrete Fourier transform (DFT) filter banks and the cosine modulated filter banks. They are well known for their low complexity. In both cases, the system is approximately alias free, and the overall response is equivalent to a tunable multilevel filter. Properties of the DFT filter banks and the cosine modulated filter banks can be exploited to simultaneously achieve parallelism, computational saving, and a lower working rate. Furthermore, for both systems, the implementation cost of the analysis or synthesis bank is comparable to that of one prototype filter plus some low-complexity modulation matrices. The individual analysis and synthesis filters have complex coefficients in the DFT filter banks but have real coefficients in the cosine modulated filter banks.

On the application of under-decimated filter banks

NASA Astrophysics Data System (ADS)

Lin, Y.-P.; Vaidyanathan, P. P.

1994-11-01

Maximally decimated filter banks have been extensively studied in the past. A filter bank is said to be under-decimated if the number of channels is more than the decimation ratio in the subbands. A maximally decimated filter bank is well known for its application in subband coding. Another application of maximally decimated filter banks is in block filtering. Convolution through block filtering has the advantages that parallelism is increased and data are processed at a lower rate. However, the computational complexity is comparable to that of direct convolution. More recently, another type of filter bank convolver has been developed. In this scheme, the convolution is performed in the subbands. Quantization and bit allocation of subband signals are based on signal variance, as in subband coding. Consequently, for a fixed rate, the result of convolution is more accurate than is direct convolution. This type of filter bank convolver also enjoys the advantages of block filtering, parallelism, and a lower working rate. Nevertheless, like block filtering, there is no computational saving. In this article, under-decimated systems are introduced to solve the problem. The new system is decimated only by half the number of channels. Two types of filter banks can be used in the under-decimated system: the discrete Fourier transform (DFT) filter banks and the cosine modulated filter banks. They are well known for their low complexity. In both cases, the system is approximately alias free, and the overall response is equivalent to a tunable multilevel filter. Properties of the DFT filter banks and the cosine modulated filter banks can be exploited to simultaneously achieve parallelism, computational saving, and a lower working rate.

Properties of lotus seed starch-glycerin monostearin complexes formed by high pressure homogenization.

PubMed

Chen, Bingyan; Zeng, Shaoxiao; Zeng, Hongliang; Guo, Zebin; Zhang, Yi; Zheng, Baodong

2017-07-01

Starch-lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high pressure homogenization (HPH) process, and the effect of HPH on the physicochemical properties of LS-GMS complexes was investigated. The results of Fourier transform infrared spectroscopy and complex index analysis showed that LS-GMS complexes were formed at 40MPa by HPH and the complex index increased with the increase of homogenization pressure. Scanning electron microscopy displayed LS-GMS complexes present more nest-shape structure with increasing homogenization pressure. X-ray diffraction and differential scanning calorimetry results revealed that V-type crystalline polymorph was formed between LS and GMS, with higher homogenization pressure producing an increasingly stable complex. LS-GMS complex inhibited starch granules swelling, solubility and pasting development, which further reduced peak and breakdown viscosity. During storage, LS-GMS complexes prepared by 70-100MPa had higher Avrami exponent values and lower recrystallization rates compared with native starch, which suggested a lower retrogradation trendency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel Method For Low-Rate Ddos Attack Detection

NASA Astrophysics Data System (ADS)

Chistokhodova, A. A.; Sidorov, I. D.

2018-05-01

The relevance of the work is associated with an increasing number of advanced types of DDoS attacks, in particular, low-rate HTTP-flood. Last year, the power and complexity of such attacks increased significantly. The article is devoted to the analysis of DDoS attacks detecting methods and their modifications with the purpose of increasing the accuracy of DDoS attack detection. The article details low-rate attacks features in comparison with conventional DDoS attacks. During the analysis, significant shortcomings of the available method for detecting low-rate DDoS attacks were found. Thus, the result of the study is an informal description of a new method for detecting low-rate denial-of-service attacks. The architecture of the stand for approbation of the method is developed. At the current stage of the study, it is possible to improve the efficiency of an already existing method by using a classifier with memory, as well as additional information.

Visibility graph analysis on quarterly macroeconomic series of China based on complex network theory

NASA Astrophysics Data System (ADS)

Wang, Na; Li, Dong; Wang, Qiwen

2012-12-01

The visibility graph approach and complex network theory provide a new insight into time series analysis. The inheritance of the visibility graph from the original time series was further explored in the paper. We found that degree distributions of visibility graphs extracted from Pseudo Brownian Motion series obtained by the Frequency Domain algorithm exhibit exponential behaviors, in which the exponential exponent is a binomial function of the Hurst index inherited in the time series. Our simulations presented that the quantitative relations between the Hurst indexes and the exponents of degree distribution function are different for different series and the visibility graph inherits some important features of the original time series. Further, we convert some quarterly macroeconomic series including the growth rates of value-added of three industry series and the growth rates of Gross Domestic Product series of China to graphs by the visibility algorithm and explore the topological properties of graphs associated from the four macroeconomic series, namely, the degree distribution and correlations, the clustering coefficient, the average path length, and community structure. Based on complex network analysis we find degree distributions of associated networks from the growth rates of value-added of three industry series are almost exponential and the degree distributions of associated networks from the growth rates of GDP series are scale free. We also discussed the assortativity and disassortativity of the four associated networks as they are related to the evolutionary process of the original macroeconomic series. All the constructed networks have “small-world” features. The community structures of associated networks suggest dynamic changes of the original macroeconomic series. We also detected the relationship among government policy changes, community structures of associated networks and macroeconomic dynamics. We find great influences of government policies in China on the changes of dynamics of GDP and the three industries adjustment. The work in our paper provides a new way to understand the dynamics of economic development.

Mechanistic Basis for High Stereoselectivity and Broad Substrate Scope in the (salen)Co(III)-Catalyzed Hydrolytic Kinetic Resolution

PubMed Central

Ford, David D.; Nielsen, Lars P. C.; Zuend, Stephan J.; Jacobsen, Eric N.

2013-01-01

In the (salen)Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of terminal epoxides, the rate- and stereoselectivity-determining epoxide ring-opening step occurs by a cooperative bimetallic mechanism with one Co(III) complex acting as a Lewis acid and another serving to deliver the hydroxide nucleophile. In this paper, we analyze the basis for the extraordinarily high stereoselectivity and broad substrate scope observed in the HKR. We demonstrate that the stereochemistry of each of the two (salen)Co(III) complexes in the rate-determining transition structure is important for productive catalysis: a measurable rate of hydrolysis occurs only if the absolute stereochemistry of each of these (salen)Co(III) complexes is the same. Experimental and computational studies provide strong evidence that stereochemical communication in the HKR is mediated by the stepped conformation of the salen ligand, and not the shape of the chiral diamine backbone of the ligand. A detailed computational analysis reveals that the epoxide binds the Lewis acidic Co(III) complex in a well-defined geometry imposed by stereoelectronic, rather than steric effects. This insight serves as the basis of a complete stereochemical and transition structure model that sheds light on the reasons for the broad substrate generality of the HKR. PMID:24041239

Mechanistic basis for high stereoselectivity and broad substrate scope in the (salen)Co(III)-catalyzed hydrolytic kinetic resolution.

PubMed

Ford, David D; Nielsen, Lars P C; Zuend, Stephan J; Musgrave, Charles B; Jacobsen, Eric N

2013-10-16

In the (salen)Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of terminal epoxides, the rate- and stereoselectivity-determining epoxide ring-opening step occurs by a cooperative bimetallic mechanism with one Co(III) complex acting as a Lewis acid and another serving to deliver the hydroxide nucleophile. In this paper, we analyze the basis for the extraordinarily high stereoselectivity and broad substrate scope observed in the HKR. We demonstrate that the stereochemistry of each of the two (salen)Co(III) complexes in the rate-determining transition structure is important for productive catalysis: a measurable rate of hydrolysis occurs only if the absolute stereochemistry of each of these (salen)Co(III) complexes is the same. Experimental and computational studies provide strong evidence that stereochemical communication in the HKR is mediated by the stepped conformation of the salen ligand, and not the shape of the chiral diamine backbone of the ligand. A detailed computational analysis reveals that the epoxide binds the Lewis acidic Co(III) complex in a well-defined geometry imposed by stereoelectronic rather than steric effects. This insight serves as the basis of a complete stereochemical and transition structure model that sheds light on the reasons for the broad substrate generality of the HKR.

Forest Inventory and Analysis (FIA) annual inventory answers the question: What is happening to pinyon-juniper woodlands?

Treesearch

John D. Shaw; Brytten E. Steed; Larry T. DeBlander

2005-01-01

Widespread mortality in the pinyon-juniper forest type is associated with several years of drought in the southwestern United States. A complex of drought, insects, and disease is responsible for pinyon mortality rates approaching 100% in some areas, while other areas have experienced little or no mortality. Implementation of the Forest Inventory and Analysis (FIA)...

Free energy landscape of the Michaelis complex of lactate dehydrogenase: A network analysis of atomistic simulations

NASA Astrophysics Data System (ADS)

Pan, Xiaoliang; Schwartz, Steven

2015-03-01

It has long been recognized that the structure of a protein is a hierarchy of conformations interconverting on multiple time scales. However, the conformational heterogeneity is rarely considered in the context of enzymatic catalysis in which the reactant is usually represented by a single conformation of the enzyme/substrate complex. Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate with concomitant interconversion of two forms of the cofactor nicotinamide adenine dinucleotide (NADH and NAD+). Recent experimental results suggest that multiple substates exist within the Michaelis complex of LDH, and they are catalytic competent at different reaction rates. In this study, millisecond-scale all-atom molecular dynamics simulations were performed on LDH to explore the free energy landscape of the Michaelis complex, and network analysis was used to characterize the distribution of the conformations. Our results provide a detailed view of the kinetic network the Michaelis complex and the structures of the substates at atomistic scale. It also shed some light on understanding the complete picture of the catalytic mechanism of LDH.

Pt-Mechanistic Study of the β-Hydrogen Elimination from Organoplatinum(II) Enolate Complexes

PubMed Central

Alexanian, Erik J.; Hartwig, John F.

2010-01-01

A detailed mechanistic investigation of the thermal reactions of a series of bisphosphine alkylplatinum(II) enolate complexes is reported. The reactions of methylplatinum enolate complexes in the presence of added phosphine form methane and either free or coordinated enone, depending on the steric properties of the enone. Kinetic studies were conducted to determine the relationship between the rates and mechanism of β-hydrogen elimination from enolate complexes and the rates and mechanism of β-hydrogen elimination from alkyl complexes. The rates of reactions of the enolates were inversely dependent on the concentration of added phosphine, indicating that β-hydrogen elimination from the enolate complexes occurs after reversible dissociation of a phosphine. A normal, primary kinetic isotope effect was measured, and this effect was consistent with rate-limiting β-hydrogen elimination or C-H bond-forming reductive elimination to form methane. Reactions of substituted enolate complexes were also studied to determine the effect of the steric and electronic properties of the enolate complexes on the rates of β-hydrogen elimination. These studies showed that reactions of the alkylplatinum enolate complexes were retarded by electron-withdrawing substituents on the enolate and that reactions of enolate complexes possessing alkyl substituents at the β-position occurred at rates that were similar to those of complexes lacking alkyl substituents at this position. Despite the trend in electronic effects on the rates of reactions of enolate complexes and the substantial electronic differences between an enolate and an alkyl ligand, the rates of decomposition of the enolate complexes were similar to those of the analogous alkyl complexes. To the extent that the rates of reaction of the two types of complex are different, those involving β-hydrogen elimination from the enolate ligand were faster. A difference between the identity of the rate-determining step for decomposition of the two classes of complexes and an effect of stereochemistry on the selectivity for β-hydrogen elimination are possible origins of the observed phenomena. PMID:18954048

Polypeptide Translocation Through the Mitochondrial TOM Channel: Temperature-Dependent Rates at the Single-Molecule Level.

PubMed

Mahendran, Kozhinjampara R; Lamichhane, Usha; Romero-Ruiz, Mercedes; Nussberger, Stephan; Winterhalter, Mathias

2013-01-03

The TOM protein complex facilitates the transfer of nearly all mitochondrial preproteins across outer mitochondrial membranes. Here we characterized the effect of temperature on facilitated translocation of a mitochondrial presequence peptide pF1β. Ion current fluctuations analysis through single TOM channels revealed thermodynamic and kinetic parameters of substrate binding and allowed determining the energy profile of peptide translocation. The activation energy for the on-rate and off-rate of the presequence peptide into the TOM complex was symmetric with respect to the electric field and estimated to be about 15 and 22 kT per peptide. These values are above that expected for free diffusion of ions in water (6 kT) and reflect the stronger interaction in the channel. Both values are in the range for typical enzyme kinetics and suggest one process without involving large conformational changes within the channel protein.

Multivariate Analysis of Income Inequality: Data from 32 Nations.

ERIC Educational Resources Information Center

Stack, Steven

To analyze income inequality in 32 nations, the research tested hypotheses based upon eight socioeconomic variables. The first seven variables, often tested in income research, were: political participation, industrial development, population growth, educational level, inflation rate, economic growth, and technological complexity. The eighth…

Mathematical modeling and fuzzy availability analysis for serial processes in the crystallization system of a sugar plant

NASA Astrophysics Data System (ADS)

Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram

2017-03-01

The binary states, i.e., success or failed state assumptions used in conventional reliability are inappropriate for reliability analysis of complex industrial systems due to lack of sufficient probabilistic information. For large complex systems, the uncertainty of each individual parameter enhances the uncertainty of the system reliability. In this paper, the concept of fuzzy reliability has been used for reliability analysis of the system, and the effect of coverage factor, failure and repair rates of subsystems on fuzzy availability for fault-tolerant crystallization system of sugar plant is analyzed. Mathematical modeling of the system is carried out using the mnemonic rule to derive Chapman-Kolmogorov differential equations. These governing differential equations are solved with Runge-Kutta fourth-order method.

Evaluation of physiologic complexity in time series using generalized sample entropy and surrogate data analysis

NASA Astrophysics Data System (ADS)

Eduardo Virgilio Silva, Luiz; Otavio Murta, Luiz

2012-12-01

Complexity in time series is an intriguing feature of living dynamical systems, with potential use for identification of system state. Although various methods have been proposed for measuring physiologic complexity, uncorrelated time series are often assigned high values of complexity, errouneously classifying them as a complex physiological signals. Here, we propose and discuss a method for complex system analysis based on generalized statistical formalism and surrogate time series. Sample entropy (SampEn) was rewritten inspired in Tsallis generalized entropy, as function of q parameter (qSampEn). qSDiff curves were calculated, which consist of differences between original and surrogate series qSampEn. We evaluated qSDiff for 125 real heart rate variability (HRV) dynamics, divided into groups of 70 healthy, 44 congestive heart failure (CHF), and 11 atrial fibrillation (AF) subjects, and for simulated series of stochastic and chaotic process. The evaluations showed that, for nonperiodic signals, qSDiff curves have a maximum point (qSDiffmax) for q ≠1. Values of q where the maximum point occurs and where qSDiff is zero were also evaluated. Only qSDiffmax values were capable of distinguish HRV groups (p-values 5.10×10-3, 1.11×10-7, and 5.50×10-7 for healthy vs. CHF, healthy vs. AF, and CHF vs. AF, respectively), consistently with the concept of physiologic complexity, and suggests a potential use for chaotic system analysis.

Growth mechanisms of MgO nanocrystals via a sol-gel synthesis using different complexing agents

PubMed Central

2014-01-01

In the preparation of nanostructured materials, it is important to optimize synthesis parameters in order to obtain the desired material. This work investigates the role of complexing agents, oxalic acid and tartaric acid, in the production of MgO nanocrystals. Results from simultaneous thermogravimetric analysis (STA) show that the two different synthesis routes yield precursors with different thermal profiles. It is found that the thermal profiles of the precursors can reveal the effects of crystal growth during thermal annealing. X-ray diffraction confirms that the final products are pure, single phase and of cubic shape. It is also found that complexing agents can affect the rate of crystal growth. The structures of the oxalic acid and tartaric acid as well as the complexation sites play very important roles in the formation of the nanocrystals. The complexing agents influence the rate of growth which affects the final crystallite size of the materials. Surprisingly, it is also found that oxalic acid and tartaric acid act as surfactants inhibiting crystal growth even at a high temperature of 950°C and a long annealing time of 36 h. The crystallite formation routes are proposed to be via linear and branched polymer networks due to the different structures of the complexing agents. PMID:24650322

The structure and stability of aqueous rare-earth elements in hydrothermal fluids: New results on neodymium(III) aqua and chloroaqua complexes in aqueous solutions to 500 °C and 520 MPa

USGS Publications Warehouse

Mayanovic, Robert A.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

2009-01-01

X-ray absorption spectroscopy (XAS) measurements were made at the Nd L3-edge on neodymium(III) aqua and chloroaqua complexes in low pH aqueous solutions from 25 to 500????C and up to 520??MPa. Analysis of the extended X-ray absorption fine structure of the XAS spectra measured from a 0.07??m Nd/0.16??m HNO3 aqueous solution reveals a contraction of the Nd-O distance of the Nd3+ aqua ion at a uniform rate of ~ 0.013????/100????C and a uniform reduction of the number of coordinated H2O molecules from 10.0 ?? 0.9 to 7.4 ?? 0.9 over the range from 25 to 500????C and up to 370??MPa. The rate of reduction of the first-shell water molecules with temperature for Nd3+ (26%) is intermediate between the rate for the Gd3+ aqua ion (22% from 25 to 500????C) and the rates for the Eu3+ (29% from 25 to 400????C) and the Yb3+ aqua ions (42% from 25 to 500????C) indicating an intermediate stability of the Nd3+ aqua ion consistent with the tetrad effect. Nd L3-edge XAS measurements of 0.05??m NdCl3 aqueous solution at 25 to 500????C and up to 520??MPa show that stepwise inner-sphere complexes most likely of the type Nd(H2O)?? - nCln+3 - n occur in the solution at elevated temperatures, where ?? ??? 9 at 150????C decreasing to ~ 6 at 500????C and the number of chloride ions (n) of the chloroaqua complexes increases uniformly with temperature from 1.2 ?? 0.2 to 2.0 ?? 0.2 in the solution upon increase of temperature from 150 to 500????C. Conversely, the number of H2O ligands of Nd(H2O)?? - nCln+3 - n complexes is uniformly reduced with temperature from 7.5 ?? 0.8 to 3.7 ?? 0.3 in the aqueous solution, in the same temperature range. These data show greater stability of neodymium(III) than gadolinium(III) and ytterbium(III) chloride complexes in low pH aqueous solutions at elevated temperatures. Our data suggest a greater stability of aqueous light REE than that of heavy REE chloride complexes in low pH fluids at elevated temperatures consistent with REE analysis of fluids from deep-sea hydrothermal vents. ?? 2008 Elsevier B.V.

Constraining processes of landscape change with combined in situ cosmogenic 14C-10Be analysis

NASA Astrophysics Data System (ADS)

Hippe, Kristina

2017-10-01

Reconstructing Quaternary landscape evolution today frequently builds upon cosmogenic-nuclide surface exposure dating. However, the study of complex surface exposure chronologies on the 102-104 years' timescale remains challenging with the commonly used long-lived radionuclides (10Be, 26Al, 36Cl). In glacial settings, key points are the inheritance of nuclides accumulated in a rock surface during a previous exposure episode and (partial) shielding of a rock surface after the main deglaciation event, e.g. during phases of glacier readvance. Combining the short-lived in situ cosmogenic 14C isotope with 10Be dating provides a valuable approach to resolve and quantify complex exposure histories and burial episodes within Lateglacial and Holocene timescales. The first studies applying the in situ14C-10Be pair have demonstrated the great benefit from in situ14C analysis for unravelling complex glacier chronologies in various glacial environments worldwide. Moreover, emerging research on in situ14C in sedimentary systems highlights the capacity of combined in situ14C-10Be analysis to quantify sediment transfer times in fluvial catchments or to constrain changes in surface erosion rates. Nevertheless, further methodological advances are needed to obtain truly routine and widely available in situ14C analysis. Future development in analytical techniques has to focus on improving the analytical reproducibility, reducing the background level and determining more accurate muonic production rates. These improvements should allow extending the field of applications for combined in situ14C-10Be analysis in Earth surface sciences and open up a number of promising applications for dating young sedimentary deposits and the quantification of recent changes in surface erosion dynamics.

A simple approach to evaluate the kinetic rate constant for ATP synthesis in resting human skeletal muscle at 7 T.

PubMed

Ren, Jimin; Sherry, A Dean; Malloy, Craig R

2016-09-01

Inversion transfer (IT) is a well-established technique with multiple attractive features for analysis of kinetics. However, its application in measurement of ATP synthesis rate in vivo has lagged behind the more common saturation transfer (ST) techniques. One well-recognized issue with IT is the complexity of data analysis in comparison with much simpler analysis by ST. This complexity arises, in part, because the γ-ATP spin is involved in multiple chemical reactions and magnetization exchanges, whereas Pi is involved in a single reaction, Pi → γ-ATP. By considering the reactions involving γ-ATP only as a lumped constant, the rate constant for the reaction of physiological interest, kPi→γATP , can be determined. Here, we present a new IT data analysis method to evaluate kPi→γATP using data collected from resting human skeletal muscle at 7 T. The method is based on the basic Bloch-McConnell equation, which relates kPi→γATP to m˙Pi, the rate of Pi magnetization change. The kPi→γATP value is accessed from m˙Pi data by more familiar linear correlation approaches. For a group of human subjects (n = 15), the kPi→γATP value derived for resting calf muscle was 0.066 ± 0.017 s(-1) , in agreement with literature-reported values. In this study we also explored possible time-saving strategies to speed up data acquisition for kPi→γATP evaluation using simulations. The analysis indicates that it is feasible to carry out a (31) P IT experiment in about 10 min or less at 7 T with reasonable outcome in kPi→γATP variance for measurement of ATP synthesis in resting human skeletal muscle. We believe that this new IT data analysis approach will facilitate the wide acceptance of IT to evaluate ATP synthesis rate in vivo. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students.

PubMed

Dimitriev, Dimitriy A; Saperova, Elena V; Dimitriev, Aleksey D

2016-01-01

Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger's State-Trait Anxiety Inventory was used to assess the level of SA. Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation.

Biological reduction of chlorinated solvents: Batch-scale geochemical modeling

NASA Astrophysics Data System (ADS)

Kouznetsova, Irina; Mao, Xiaomin; Robinson, Clare; Barry, D. A.; Gerhard, Jason I.; McCarty, Perry L.

2010-09-01

Simulation of biodegradation of chlorinated solvents in dense non-aqueous phase liquid (DNAPL) source zones requires a model that accounts for the complexity of processes involved and that is consistent with available laboratory studies. This paper describes such a comprehensive modeling framework that includes microbially mediated degradation processes, microbial population growth and decay, geochemical reactions, as well as interphase mass transfer processes such as DNAPL dissolution, gas formation and mineral precipitation/dissolution. All these processes can be in equilibrium or kinetically controlled. A batch modeling example was presented where the degradation of trichloroethene (TCE) and its byproducts and concomitant reactions (e.g., electron donor fermentation, sulfate reduction, pH buffering by calcite dissolution) were simulated. Local and global sensitivity analysis techniques were applied to delineate the dominant model parameters and processes. Sensitivity analysis indicated that accurate values for parameters related to dichloroethene (DCE) and vinyl chloride (VC) degradation (i.e., DCE and VC maximum utilization rates, yield due to DCE utilization, decay rate for DCE/VC dechlorinators) are important for prediction of the overall dechlorination time. These parameters influence the maximum growth rate of the DCE and VC dechlorinating microorganisms and, thus, the time required for a small initial population to reach a sufficient concentration to significantly affect the overall rate of dechlorination. Self-inhibition of chlorinated ethenes at high concentrations and natural buffering provided by the sediment were also shown to significantly influence the dechlorination time. Furthermore, the analysis indicated that the rates of the competing, nonchlorinated electron-accepting processes relative to the dechlorination kinetics also affect the overall dechlorination time. Results demonstrated that the model developed is a flexible research tool that is able to provide valuable insight into the fundamental processes and their complex interactions during bioremediation of chlorinated ethenes in DNAPL source zones.

NMR Investigation of Chloromethane Complexes of Cryptophane-A and Its Analogue with Butoxy Groups

PubMed Central

2014-01-01

Host–guest complexes between cryptophane-A as host and dichloromethane and chloroform as guests are investigated using 1H and 13C NMR spectroscopy. Moreover, a related cryptophane, with the methoxy groups replaced by butoxy units (cryptophane-But), and its complexes with the same guests were also studied. Variable temperature spectra showed effects of chemical exchange between the free and bound guests, as well as of conformational exchange of the host. The guest exchange was studied quantitatively by exchange spectroscopy or line shape analysis. Extraction of kinetic and thermodynamic parameters led to the characterization of the affinity between guests and hosts. On the other hand, the host exchange was investigated by means of 13C Carr–Purcell–Meiboom–Gill (CPMG) relaxation dispersion which aims at the determination of the transverse relaxation rate R2, the inverse of the transverse relaxation time T2, as a function of the repetition of the π pulses in a CPMG train. The variation of the measured transverse relaxation rate with the repetition rate νCPMG indicated conformational exchange occurring on the microsecond–millisecond time scale. Structural information was obtained through measurements of cross-relaxation rates, both within the host and between the host and the guest protons. The NMR results were supported by DFT calculations. PMID:24472055

An analysis of landing rates and separations at the Dallas/Fort Worth International Airport

NASA Technical Reports Server (NTRS)

Ballin, Mark G.; Erzberger, Heinz

1996-01-01

Advanced air traffic management systems such as the Center/TRACON Automation System (CTAS) should yield a wide range of benefits, including reduced aircraft delays and controller workload. To determine the traffic-flow benefits achievable from future terminal airspace automation, live radar information was used to perform an analysis of current aircraft landing rates and separations at the Dallas/Fort Worth International Airport. Separation statistics that result when controllers balance complex control procedural constraints in order to maintain high landing rates are presented. In addition, the analysis estimates the potential for airport capacity improvements by determining the unused landing opportunities that occur during rush traffic periods. Results suggest a large potential for improving the accuracy and consistency of spacing between arrivals on final approach, and they support earlier simulation findings that improved air traffic management would increase capacity and reduce delays.

Precise Calculation of a Bond Percolation Transition and Survival Rates of Nodes in a Complex Network

PubMed Central

Kawamoto, Hirokazu; Takayasu, Hideki; Jensen, Henrik Jeldtoft; Takayasu, Misako

2015-01-01

Through precise numerical analysis, we reveal a new type of universal loopless percolation transition in randomly removed complex networks. As an example of a real-world network, we apply our analysis to a business relation network consisting of approximately 3,000,000 links among 300,000 firms and observe the transition with critical exponents close to the mean-field values taking into account the finite size effect. We focus on the largest cluster at the critical point, and introduce survival probability as a new measure characterizing the robustness of each node. We also discuss the relation between survival probability and k-shell decomposition. PMID:25885791

Complexation facilitated reduction of aromatic N-oxides by aqueous Fe(II)-tiron complex: reaction kinetics and mechanisms.

PubMed

Chen, Yiling; Zhang, Huichun

2013-10-01

Rapid reduction of carbadox (CDX), olaquindox and several other aromatic N-oxides were investigated in aqueous solution containing Fe(II) and tiron. Consistent with previous work, the 1:2 Fe(II)-tiron complex, FeL2(6-), is the dominant reactive species as its concentration linearly correlates with the observed rate constant kobs under various conditions. The N-oxides without any side chains were much less reactive, suggesting direct reduction of the N-oxides is slow. UV-vis spectra suggest FeL2(6-) likely forms 5- or 7-membered rings with CDX and olaquindox through the N and O atoms on the side chain. The formed inner-sphere complexes significantly facilitated electron transfer from FeL2(6-) to the N-oxides. Reduction products of the N-oxides were identified by HPLC/QToF-MS to be the deoxygenated analogs. QSAR analysis indicated neither the first electron transfer nor N-O bond cleavage is the rate-limiting step. Calculations of the atomic spin densities of the anionic N-oxides confirmed the extensive delocalization between the aromatic ring and the side chain, suggesting complex formation can significantly affect the reduction kinetics. Our results suggest the complexation facilitated N-oxide reduction by Fe(II)-tiron involves a free radical mechanism, and the subsequent deoxygenation might also benefit from the weak complexation of Fe(II) with the N-oxide O atom.

Relationship of Complexity Factor Ratings With Operational Errors

DTIC Science & Technology

2007-05-01

losing information about their interrelationships. Prior to the analysis, the Kaiser-Meyer-Olkin ( KMO ) measure of sampling adequacy was examined to...test whether partial correlations among the variables were small. KMO values of .6 and above are required for a good solution. A KMO of .87 was

The Effect of Multispectral Image Fusion Enhancement on Human Efficiency

DTIC Science & Technology

2017-03-20

human visual system by applying a technique commonly used in visual percep- tion research : ideal observer analysis. Using this approach, we establish...applications, analytic tech- niques, and procedural methods used across studies. This paper uses ideal observer analysis to establish a frame- work that allows...augmented similarly to incorpo- rate research involving more complex stimulus content. Additionally, the ideal observer can be adapted for a number of

Synthesis and spectral studies of heterocyclic azo dye complexes with some transition metals

NASA Astrophysics Data System (ADS)

Jarad, A. J.; Majeed, I. Y.; Hussein, A. O.

2018-05-01

6-(2-benzathiazolyl azo) -3,5-dimethylphenol was formed by grouping the 2-benzothiazole diazonium chloride with 3,5-dimethylphenol. Azo ligand(L) was resolved on the origin by 1H and 13CNMR, FTIR and UV-Vis spectral analysis. Complexation of tridentate ligand (L) with Co2+, Ni2+, Cu2+ and Zn2+ in aqueous of ethyl alcohol with a 1:2 metal:ligand, and at ideal pH.. The formation of metal chelates are assigned using flame atomic absorption, FTIR and UV-Vis spectral analysis, other than conductivity and magnetic estates. The nature of the metal chelates were carried out by mole ratio and continuous variation mechanism, Beer’s law followed the rate (0.0001 - 3×0.0001 M) concentration. High molar absorptivity for the complex solutions were observed. On the origin data an octahedral geometry were described for the metal chelates. Biological activity of the ready compounds were assayed.

Distinguishing fiction from non-fiction with complex networks

NASA Astrophysics Data System (ADS)

Larue, David M.; Carr, Lincoln D.; Jones, Linnea K.; Stevanak, Joe T.

2014-03-01

Complex Network Measures are applied to networks constructed from texts in English to demonstrate an initial viability in textual analysis. Texts from novels and short stories obtained from Project Gutenberg and news stories obtained from NPR are selected. Unique word stems in a text are used as nodes in an associated unweighted undirected network, with edges connecting words occurring within a certain number of words somewhere in the text. Various combinations of complex network measures are computed for each text's network. Fisher's Linear Discriminant analysis is used to build a parameter optimizing the ability to separate the texts according to their genre. Success rates in the 70% range for correctly distinguishing fiction from non-fiction were obtained using edges defined as within four words, using 400 word samples from 400 texts from each of the two genres with some combinations of measures such as the power-law exponents of degree distributions and clustering coefficients.

Oxygen Atom Exchange between H2O and Non-Heme Oxoiron(IV) Complexes: Ligand Dependence and Mechanism.

PubMed

Puri, Mayank; Company, Anna; Sabenya, Gerard; Costas, Miquel; Que, Lawrence

2016-06-20

Detailed studies of oxygen atom exchange (OAE) between H2(18)O and synthetic non-heme oxoiron(IV) complexes supported by tetradentate and pentadentate ligands provide evidence that they proceed by a common mechanism but within two different kinetic regimes, with OAE rates that span 2 orders of magnitude. The first kinetic regime involves initial reversible water association to the Fe(IV) complex, which is evidenced by OAE rates that are linearly dependent on [H2(18)O] and H2O/D2O KIEs of 1.6, while the second kinetic regime involves a subsequent rate determining proton-transfer step between the bound aqua and oxo ligands that is associated with saturation behavior with [H2(18)O] and much larger H2O/D2O KIEs of 5-6. [Fe(IV)(O)(TMC)(MeCN)](2+) (1) and [Fe(IV)(O)(MePy2TACN)](2+) (9) are examples of complexes that exhibit kinetic behavior in the first regime, while [Fe(IV)(O)(N4Py)](2+) (3), [Fe(IV)(O)(BnTPEN)](2+) (4), [Fe(IV)(O)(1Py-BnTPEN)](2+) (5), [Fe(IV)(O)(3Py-BnTPEN)](2+) (6), and [Fe(IV)(O)(Me2Py2TACN)](2+) (8) represent complexes that fall in the second kinetic regime. Interestingly, [Fe(IV)(O)(PyTACN)(MeCN)](2+) (7) exhibits a linear [H2(18)O] dependence below 0.6 M and saturation above 0.6 M. Analysis of the temperature dependence of the OAE rates shows that most of these complexes exhibit large and negative activation entropies, consistent with the proposed mechanism. One exception is complex 9, which has a near-zero activation entropy and is proposed to undergo ligand-arm dissociation during the RDS to accommodate H2(18)O binding. These results show that the observed OAE kinetic behavior is highly dependent on the nature of the supporting ligand and are of relevance to studies of non-heme oxoiron(IV) complexes in water or acetonitrile/water mixtures for applications in photocatalysis and water oxidation chemistry.

Advancing Clinical Proteomics via Analysis Based on Biological Complexes: A Tale of Five Paradigms.

PubMed

Goh, Wilson Wen Bin; Wong, Limsoon

2016-09-02

Despite advances in proteomic technologies, idiosyncratic data issues, for example, incomplete coverage and inconsistency, resulting in large data holes, persist. Moreover, because of naïve reliance on statistical testing and its accompanying p values, differential protein signatures identified from such proteomics data have little diagnostic power. Thus, deploying conventional analytics on proteomics data is insufficient for identifying novel drug targets or precise yet sensitive biomarkers. Complex-based analysis is a new analytical approach that has potential to resolve these issues but requires formalization. We categorize complex-based analysis into five method classes or paradigms and propose an even-handed yet comprehensive evaluation rubric based on both simulated and real data. The first four paradigms are well represented in the literature. The fifth and newest paradigm, the network-paired (NP) paradigm, represented by a method called Extremely Small SubNET (ESSNET), dominates in precision-recall and reproducibility, maintains strong performance in small sample sizes, and sensitively detects low-abundance complexes. In contrast, the commonly used over-representation analysis (ORA) and direct-group (DG) test paradigms maintain good overall precision but have severe reproducibility issues. The other two paradigms considered here are the hit-rate and rank-based network analysis paradigms; both of these have good precision-recall and reproducibility, but they do not consider low-abundance complexes. Therefore, given its strong performance, NP/ESSNET may prove to be a useful approach for improving the analytical resolution of proteomics data. Additionally, given its stability, it may also be a powerful new approach toward functional enrichment tests, much like its ORA and DG counterparts.

Quantitative chemical exchange saturation transfer (qCEST) MRI - omega plot analysis of RF-spillover-corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate.

PubMed

Wu, Renhua; Xiao, Gang; Zhou, Iris Yuwen; Ran, Chongzhao; Sun, Phillip Zhe

2015-03-01

Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST-weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH-dependent exchange rate followed a dominantly base-catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd.

Analysis of single-molecule fluorescence spectroscopic data with a Markov-modulated Poisson process.

PubMed

Jäger, Mark; Kiel, Alexander; Herten, Dirk-Peter; Hamprecht, Fred A

2009-10-05

We present a photon-by-photon analysis framework for the evaluation of data from single-molecule fluorescence spectroscopy (SMFS) experiments using a Markov-modulated Poisson process (MMPP). A MMPP combines a discrete (and hidden) Markov process with an additional Poisson process reflecting the observation of individual photons. The algorithmic framework is used to automatically analyze the dynamics of the complex formation and dissociation of Cu2+ ions with the bidentate ligand 2,2'-bipyridine-4,4'dicarboxylic acid in aqueous media. The process of association and dissociation of Cu2+ ions is monitored with SMFS. The dcbpy-DNA conjugate can exist in two or more distinct states which influence the photon emission rates. The advantage of a photon-by-photon analysis is that no information is lost in preprocessing steps. Different model complexities are investigated in order to best describe the recorded data and to determine transition rates on a photon-by-photon basis. The main strength of the method is that it allows to detect intermittent phenomena which are masked by binning and that are difficult to find using correlation techniques when they are short-lived.

An online sleep apnea detection method based on recurrence quantification analysis.

PubMed

Nguyen, Hoa Dinh; Wilkins, Brek A; Cheng, Qi; Benjamin, Bruce Allen

2014-07-01

This paper introduces an online sleep apnea detection method based on heart rate complexity as measured by recurrence quantification analysis (RQA) statistics of heart rate variability (HRV) data. RQA statistics can capture nonlinear dynamics of a complex cardiorespiratory system during obstructive sleep apnea. In order to obtain a more robust measurement of the nonstationarity of the cardiorespiratory system, we use different fixed amount of neighbor thresholdings for recurrence plot calculation. We integrate a feature selection algorithm based on conditional mutual information to select the most informative RQA features for classification, and hence, to speed up the real-time classification process without degrading the performance of the system. Two types of binary classifiers, i.e., support vector machine and neural network, are used to differentiate apnea from normal sleep. A soft decision fusion rule is developed to combine the results of these classifiers in order to improve the classification performance of the whole system. Experimental results show that our proposed method achieves better classification results compared with the previous recurrence analysis-based approach. We also show that our method is flexible and a strong candidate for a real efficient sleep apnea detection system.

[Complex formation between alpha-chymotrypsin and block copolymers based on ethylene and propylene oxide, induced by high pressure].

PubMed

Topchieva, I N; Sorokina, E M; Kurganov, B I; Zhulin, V M; Makarova, Z G

1996-06-01

A new method of formation of non-covalent adducts based on an amphiphilic diblock copolymer of ethylene and propylene oxides with molecular mass of 2 kDa and alpha-chymotrypsin (ChT) under high pressure, has been developed. The composition of the complexes corresponds to seven polymer molecules per one ChT molecule in the pressure range of 1.1 to 400 MPa. The complexes fully retain the catalytic activity. Kinetic constants (Km and kcat) for enzymatic hydrolysis of N-benzoyl-L-tyrosine ethyl ester catalyzed by the complexes are identical with the corresponding values for native ChT. Analysis of kinetics of thermal inactivation of the complexes revealed that the constant of the rate of the slow inactivation step is markedly lower than for ChT.

The Impact of Noise on the Reliability of Heart-Rate Variability and Complexity Analysis in Trauma Patients

DTIC Science & Technology

2013-01-01

endotracheal intubations, 30 transfusions, 18 tube thoracos- tomies, 9 cardiopulmonary resuscitations , 8 needle decompressions, 1 angio-embolization...monitoring in very low birth weight neonates : a randomized trial, J. Pediatr. 6 (2011) 900–906. [11] J.R. Moorman, J.B. Delos, A.A. Flower, H. Cao, B.P...Kovatchev, J.S. Richman, D.E. Lake, Cardiovascular oscillations at the bedside: early diagnosis of neonatal sepsis using heart rate characteristics

Population dose-response analysis of daily seizure count following vigabatrin therapy in adult and pediatric patients with refractory complex partial seizures.

PubMed

Nielsen, Jace C; Hutmacher, Matthew M; Wesche, David L; Tolbert, Dwain; Patel, Mahlaqa; Kowalski, Kenneth G

2015-01-01

Vigabatrin is an irreversible inhibitor of γ-aminobutyric acid transaminase (GABA-T) and is used as an adjunctive therapy for adult patients with refractory complex partial seizures (rCPS). The purpose of this investigation was to describe the relationship between vigabatrin dosage and daily seizure rate for adults and children with rCPS and identify relevant covariates that might impact seizure frequency. This population dose-response analysis used seizure-count data from three pediatric and two adult randomized controlled studies of rCPS patients. A negative binomial distribution model adequately described daily seizure data. Mean seizure rate decreased with time after first dose and was described using an asymptotic model. Vigabatrin drug effects were best characterized by a quadratic model using normalized dosage as the exposure metric. Normalized dosage was an estimated parameter that allowed for individualized changes in vigabatrin exposure based on body weight. Baseline seizure rate increased with decreasing age, but age had no impact on vigabatrin drug effects after dosage was normalized for body weight differences. Posterior predictive checks indicated the final model was capable of simulating data consistent with observed daily seizure counts. Total normalized vigabatrin dosages of 1, 3, and 6 g/day were predicted to reduce seizure rates 23.2%, 45.6%, and 48.5%, respectively. © 2014, The American College of Clinical Pharmacology.

The effects of daily weather variables on psychosis admissions to psychiatric hospitals

NASA Astrophysics Data System (ADS)

McWilliams, Stephen; Kinsella, Anthony; O'Callaghan, Eadbhard

2013-07-01

Several studies have noted seasonal variations in admission rates of patients with psychotic illnesses. However, the changeable daily meteorological patterns within seasons have never been examined in any great depth in the context of admission rates. A handful of small studies have posed interesting questions regarding a potential link between psychiatric admission rates and meteorological variables such as environmental temperature (especially heat waves) and sunshine. In this study, we used simple non-parametric testing and more complex ARIMA and time-series regression analysis to examine whether daily meteorological patterns (wind speed and direction, barometric pressure, rainfall, sunshine, sunlight and temperature) exert an influence on admission rates for psychotic disorders across 12 regions in Ireland. Although there were some weak but interesting trends for temperature, barometric pressure and sunshine, the meteorological patterns ultimately did not exert a clinically significant influence over admissions for psychosis. Further analysis is needed.

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

Stein, R.L.

A procedure for the analysis of observed isotope effects on rates of complex reactions is outlined which can be applied to kinetic isotope effect data for any reaction having a virtual transition state whose structure can be varied by adjusting a reaction parameter. This procedure is applied to the basic hydrolysis of p-nitroacetanilide. 3 tables. (DLC)

Understanding Catalan University Dropout from a Cross-National Approach

ERIC Educational Resources Information Center

Rodríguez-Gómez, David; Feixas, Mònica; Gairín, Joaquín; Muñoz, José Luís

2015-01-01

The dropout rate is an indicator of complex analysis and there is no consensus on its significance. Universities lack systematized, univocal methods for collecting student dropout data, making measurement problematic. In consequence, the formulas applied to analyze this phenomenon differ between countries and it is therefore an immense challenge…

Improving estimation of kinetic parameters in dynamic force spectroscopy using cluster analysis

NASA Astrophysics Data System (ADS)

Yen, Chi-Fu; Sivasankar, Sanjeevi

2018-03-01

Dynamic Force Spectroscopy (DFS) is a widely used technique to characterize the dissociation kinetics and interaction energy landscape of receptor-ligand complexes with single-molecule resolution. In an Atomic Force Microscope (AFM)-based DFS experiment, receptor-ligand complexes, sandwiched between an AFM tip and substrate, are ruptured at different stress rates by varying the speed at which the AFM-tip and substrate are pulled away from each other. The rupture events are grouped according to their pulling speeds, and the mean force and loading rate of each group are calculated. These data are subsequently fit to established models, and energy landscape parameters such as the intrinsic off-rate (koff) and the width of the potential energy barrier (xβ) are extracted. However, due to large uncertainties in determining mean forces and loading rates of the groups, errors in the estimated koff and xβ can be substantial. Here, we demonstrate that the accuracy of fitted parameters in a DFS experiment can be dramatically improved by sorting rupture events into groups using cluster analysis instead of sorting them according to their pulling speeds. We test different clustering algorithms including Gaussian mixture, logistic regression, and K-means clustering, under conditions that closely mimic DFS experiments. Using Monte Carlo simulations, we benchmark the performance of these clustering algorithms over a wide range of koff and xβ, under different levels of thermal noise, and as a function of both the number of unbinding events and the number of pulling speeds. Our results demonstrate that cluster analysis, particularly K-means clustering, is very effective in improving the accuracy of parameter estimation, particularly when the number of unbinding events are limited and not well separated into distinct groups. Cluster analysis is easy to implement, and our performance benchmarks serve as a guide in choosing an appropriate method for DFS data analysis.

The 2-Oxoacid Dehydrogenase Complexes in Mitochondria Can Produce Superoxide/Hydrogen Peroxide at Much Higher Rates Than Complex I*

PubMed Central

Quinlan, Casey L.; Goncalves, Renata L. S.; Hey-Mogensen, Martin; Yadava, Nagendra; Bunik, Victoria I.; Brand, Martin D.

2014-01-01

Several flavin-dependent enzymes of the mitochondrial matrix utilize NAD+ or NADH at about the same operating redox potential as the NADH/NAD+ pool and comprise the NADH/NAD+ isopotential enzyme group. Complex I (specifically the flavin, site IF) is often regarded as the major source of matrix superoxide/H2O2 production at this redox potential. However, the 2-oxoglutarate dehydrogenase (OGDH), branched-chain 2-oxoacid dehydrogenase (BCKDH), and pyruvate dehydrogenase (PDH) complexes are also capable of considerable superoxide/H2O2 production. To differentiate the superoxide/H2O2-producing capacities of these different mitochondrial sites in situ, we compared the observed rates of H2O2 production over a range of different NAD(P)H reduction levels in isolated skeletal muscle mitochondria under conditions that favored superoxide/H2O2 production from complex I, the OGDH complex, the BCKDH complex, or the PDH complex. The rates from all four complexes increased at higher NAD(P)H/NAD(P)+ ratios, although the 2-oxoacid dehydrogenase complexes produced superoxide/H2O2 at high rates only when oxidizing their specific 2-oxoacid substrates and not in the reverse reaction from NADH. At optimal conditions for each system, superoxide/H2O2 was produced by the OGDH complex at about twice the rate from the PDH complex, four times the rate from the BCKDH complex, and eight times the rate from site IF of complex I. Depending on the substrates present, the dominant sites of superoxide/H2O2 production at the level of NADH may be the OGDH and PDH complexes, but these activities may often be misattributed to complex I. PMID:24515115

Reducing cognitive load while teaching complex instruction to occupational therapy students.

PubMed

Pociask, Fredrick D; DiZazzo-Miller, Rosanne; Samuel, Preethy S

2013-01-01

Cognitive load theory is a field of research used to improve the learning of complex cognitive tasks by matching instruction to the learner's cognitive architecture. We used an experimental posttest control-group design to test the effectiveness of instruction designed to reduce cognitive load (CL) and improve instructional effectiveness in teaching complex instruction to 24 first-year master's students under authentic classroom conditions. We modified historically taught instruction using an isolated-to-interacting-elements sequencing approach intended to reduce high CL levels. We compared control and modified instructional formats using written assessment scores, subjective ratings of CL, and task completion times. Analysis of variance revealed significant differences for postinstruction, posttest CL ratings, and delayed written posttest scores (p < .05). No significant differences were identified for posttest completion times. Findings suggest that this approach can be used to improve instructional efficiency in teaching human locomotion to occupational therapy students. Copyright © 2013 by the American Occupational Therapy Association, Inc.

Fetal Heart Rate Monitoring During Surgical Correction of Spontaneous Pneumothorax During Pregnancy: Lessons in In Utero Resuscitation.

PubMed

Wilson, Bailey; Burt, Bryan; Baker, Byron; Clark, Steven L; Belfort, Michael; Gandhi, Manisha

2016-01-01

Spontaneous pneumothorax during pregnancy has potentially serious implications for the mother and fetus. When surgical correction is required, complex maternal physiologic alterations may significantly affect fetal well-being. A woman underwent thoracoscopic lung resection and pleurodesis at 29 weeks of gestation. At various points during the procedure, maternal hemodynamic and respiratory consequences of anesthetic and surgical management resulted in severe fetal heart rate (FHR) decelerations and bradycardia. In each instance, physiologic manipulations based on an understanding of the likely cause of fetal hypoxia allowed correction of the FHR abnormalities without delivery. Nonsurgical perinatal intervention based on FHR monitoring and analysis of the likely pathophysiologic abnormalities underlying fetal decelerations may allow the gravid woman to undergo complex procedures and continue the pregnancy.

Edge Fracture in Complex Fluids.

PubMed

Hemingway, Ewan J; Kusumaatmaja, Halim; Fielding, Suzanne M

2017-07-14

We study theoretically the edge fracture instability in sheared complex fluids, by means of linear stability analysis and direct nonlinear simulations. We derive an exact analytical expression for the onset of edge fracture in terms of the shear-rate derivative of the fluid's second normal stress difference, the shear-rate derivative of the shear stress, the jump in shear stress across the interface between the fluid and the outside medium (usually air), the surface tension of that interface, and the rheometer gap size. We provide a full mechanistic understanding of the edge fracture instability, carefully validated against our simulations. These findings, which are robust with respect to choice of rheological constitutive model, also suggest a possible route to mitigating edge fracture, potentially allowing experimentalists to achieve and accurately measure flows stronger than hitherto possible.

The integrated manual and automatic control of complex flight systems

NASA Technical Reports Server (NTRS)

Schmidt, D. K.

1986-01-01

The topics of research in this program include pilot/vehicle analysis techniques, identification of pilot dynamics, and control and display synthesis techniques for optimizing aircraft handling qualities. The project activities are discussed. The current technical activity is directed at extending and validating the active display synthesis procedure, and the pilot/vehicle analysis of the NLR rate-command flight configurations in the landing task. Two papers published by the researchers are attached as appendices.

Non-extensivity and complexity in the earthquake activity at the West Corinth rift (Greece)

NASA Astrophysics Data System (ADS)

Michas, Georgios; Vallianatos, Filippos; Sammonds, Peter

2013-04-01

Earthquakes exhibit complex phenomenology that is revealed from the fractal structure in space, time and magnitude. For that reason other tools rather than the simple Poissonian statistics seem more appropriate to describe the statistical properties of the phenomenon. Here we use Non-Extensive Statistical Physics [NESP] to investigate the inter-event time distribution of the earthquake activity at the west Corinth rift (central Greece). This area is one of the most seismotectonically active areas in Europe, with an important continental N-S extension and high seismicity rates. NESP concept refers to the non-additive Tsallis entropy Sq that includes Boltzmann-Gibbs entropy as a particular case. This concept has been successfully used for the analysis of a variety of complex dynamic systems including earthquakes, where fractality and long-range interactions are important. The analysis indicates that the cumulative inter-event time distribution can be successfully described with NESP, implying the complexity that characterizes the temporal occurrences of earthquakes. Further on, we use the Tsallis entropy (Sq) and the Fischer Information Measure (FIM) to investigate the complexity that characterizes the inter-event time distribution through different time windows along the evolution of the seismic activity at the West Corinth rift. The results of this analysis reveal a different level of organization and clusterization of the seismic activity in time. Acknowledgments. GM wish to acknowledge the partial support of the Greek State Scholarships Foundation (IKY).

An improved method of measuring heart rate using a webcam

NASA Astrophysics Data System (ADS)

Liu, Yi; Ouyang, Jianfei; Yan, Yonggang

2014-09-01

Measuring heart rate traditionally requires special equipment and physical contact with the subject. Reliable non-contact and low-cost measurements are highly desirable for convenient and comfortable physiological self-assessment. Previous work has shown that consumer-grade cameras can provide useful signals for remote heart rate measurements. In this paper a simple and robust method of measuring the heart rate using low-cost webcam is proposed. Blood volume pulse is extracted by proper Region of Interest (ROI) and color channel selection from image sequences of human faces without complex computation. Heart rate is subsequently quantified by spectrum analysis. The method is successfully applied under natural lighting conditions. Results of experiments show that it takes less time, is much simpler, and has similar accuracy to the previously published and widely used method of Independent Component Analysis (ICA). Benefitting from non-contact, convenience, and low-costs, it provides great promise for popularization of home healthcare and can further be applied to biomedical research.

Modeling association among demographic parameters in analysis of open population capture-recapture data.

PubMed

Link, William A; Barker, Richard J

2005-03-01

We present a hierarchical extension of the Cormack-Jolly-Seber (CJS) model for open population capture-recapture data. In addition to recaptures of marked animals, we model first captures of animals and losses on capture. The parameter set includes capture probabilities, survival rates, and birth rates. The survival rates and birth rates are treated as a random sample from a bivariate distribution, thus the model explicitly incorporates correlation in these demographic rates. A key feature of the model is that the likelihood function, which includes a CJS model factor, is expressed entirely in terms of identifiable parameters; losses on capture can be factored out of the model. Since the computational complexity of classical likelihood methods is prohibitive, we use Markov chain Monte Carlo in a Bayesian analysis. We describe an efficient candidate-generation scheme for Metropolis-Hastings sampling of CJS models and extensions. The procedure is illustrated using mark-recapture data for the moth Gonodontis bidentata.

Modeling association among demographic parameters in analysis of open population capture-recapture data

USGS Publications Warehouse

Link, William A.; Barker, Richard J.

2005-01-01

We present a hierarchical extension of the Cormack–Jolly–Seber (CJS) model for open population capture–recapture data. In addition to recaptures of marked animals, we model first captures of animals and losses on capture. The parameter set includes capture probabilities, survival rates, and birth rates. The survival rates and birth rates are treated as a random sample from a bivariate distribution, thus the model explicitly incorporates correlation in these demographic rates. A key feature of the model is that the likelihood function, which includes a CJS model factor, is expressed entirely in terms of identifiable parameters; losses on capture can be factored out of the model. Since the computational complexity of classical likelihood methods is prohibitive, we use Markov chain Monte Carlo in a Bayesian analysis. We describe an efficient candidate-generation scheme for Metropolis–Hastings sampling of CJS models and extensions. The procedure is illustrated using mark-recapture data for the moth Gonodontis bidentata.

Common multifractality in the heart rate variability and brain activity of healthy humans

NASA Astrophysics Data System (ADS)

Lin, D. C.; Sharif, A.

2010-06-01

The influence from the central nervous system on the human multifractal heart rate variability (HRV) is examined under the autonomic nervous system perturbation induced by the head-up-tilt body maneuver. We conducted the multifractal factorization analysis to factor out the common multifractal factor in the joint fluctuation of the beat-to-beat heart rate and electroencephalography data. Evidence of a central link in the multifractal HRV was found, where the transition towards increased (decreased) HRV multifractal complexity is associated with a stronger (weaker) multifractal correlation between the central and autonomic nervous systems.

Attrition in trials evaluating complex interventions for schizophrenia: Systematic review and meta-analysis.

PubMed

Szymczynska, P; Walsh, S; Greenberg, L; Priebe, S

2017-07-01

Essential criteria for the methodological quality and validity of randomized controlled trials are the drop-out rates from both the experimental intervention and the study as a whole. This systematic review and meta-analysis assessed these drop-out rates in non-pharmacological schizophrenia trials. A systematic literature search was used to identify relevant trials with ≥100 sample size and to extract the drop-out data. The rates of drop-out from the experimental intervention and study were calculated with meta-analysis of proportions. Meta-regression was applied to explore the association between the study and sample characteristics and the drop-out rates. 43 RCTs were found, with drop-out from intervention ranging from 0% to 63% and study drop-out ranging from 4% to 71%. Meta-analyses of proportions showed an overall drop-out rate of 14% (95% CI: 13-15%) at the experimental intervention level and 20% (95% CI: 17-24%) at the study level. Meta-regression showed that the active intervention drop-out rates were predicted by the number of intervention sessions. In non-pharmacological schizophrenia trials, drop-out rates of less than 20% can be achieved for both the study and the experimental intervention. A high heterogeneity of drop-out rates across studies shows that even lower rates are achievable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption and photocatalytic properties of transition metal Zinc(II) complex based on 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid

NASA Astrophysics Data System (ADS)

Qiao, Yu; Ren, Shan-Shan; Liu, Li-Hui; Guan, Wei-Sheng; Li, Zhi-Min; Che, Guang-Bo; Liu, Chun-Bo; Wang, Yan-Yan; Wang, Qing-Wei; Li, Xiu-Ying; Zhu, En-Wei

2018-06-01

A new coordination polymeric zinc(II) complex, namely, [Zn2(L)(H2O)3]n·nNO3(1), (H3L = 5-(4-(tetrazol-5-yl)phenyl)isophthalic acid) has been synthesized under solvothermal conditions and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction analysis and powder X-ray diffraction. Complex 1 exhibits a three-dimensional structure with a Schläfli symbol of 44•69•82 topologies, constructed from two crystallographically independent five and six coordinated mode with metal center and connected H3L ligands. The complex has good thermal stability and excellent photoluminescent property. Furthermore, by comparing the photoluminescent and photocatalytic mutation results induced by interconversion of metal ions, we confirm that the properties mutation induced by metal ions is much controllable and obvious. In addition, the complex exhibits significantly enhanced photocatalytic activity for methylene blue (MB) under UV light irradiation (λ < 400 nm), and the degradation rate could reach 75% in 80 min. Meanwhile trapping experiments indicated that the •O2- and h+ are the main activated species.

Testing convergent and parallel adaptations in talpids humeral mechanical performance by means of geometric morphometrics and finite element analysis.

PubMed

Piras, P; Sansalone, G; Teresi, L; Kotsakis, T; Colangelo, P; Loy, A

2012-07-01

The shape and mechanical performance in Talpidae humeri were studied by means of Geometric Morphometrics and Finite Element Analysis, including both extinct and extant taxa. The aim of this study was to test whether the ability to dig, quantified by humerus mechanical performance, was characterized by convergent or parallel adaptations in different clades of complex tunnel digger within Talpidae, that is, Talpinae+Condylura (monophyletic) and some complex tunnel diggers not belonging to this clade. Our results suggest that the pattern underlying Talpidae humerus evolution is evolutionary parallelism. However, this insight changed to true convergence when we tested an alternative phylogeny based on molecular data, with Condylura moved to a more basal phylogenetic position. Shape and performance analyses, as well as specific comparative methods, provided strong evidence that the ability to dig complex tunnels reached a functional optimum in distantly related taxa. This was also confirmed by the lower phenotypic variance in complex tunnel digger taxa, compared to non-complex tunnel diggers. Evolutionary rates of phenotypic change showed a smooth deceleration in correspondence with the most recent common ancestor of the Talpinae+Condylura clade. Copyright © 2012 Wiley Periodicals, Inc.

Glutathione-complexed [2Fe-2S] clusters function in Fe-S cluster storage and trafficking.

PubMed

Fidai, Insiya; Wachnowsky, Christine; Cowan, J A

2016-10-01

Glutathione-coordinated [2Fe-2S] complex is a non-protein-bound [2Fe-2S] cluster that is capable of reconstituting the human iron-sulfur cluster scaffold protein IscU. This complex demonstrates physiologically relevant solution chemistry and is a viable substrate for iron-sulfur cluster transport by Atm1p exporter protein. Herein, we report on some of the possible functional and physiological roles for this novel [2Fe-2S](GS4) complex in iron-sulfur cluster biosynthesis and quantitatively characterize its role in the broader network of Fe-S cluster transfer reactions. UV-vis and circular dichroism spectroscopy have been used in kinetic studies to determine second-order rate constants for [2Fe-2S] cluster transfer from [2Fe-2S](GS4) complex to acceptor proteins, such as human IscU, Schizosaccharomyces pombe Isa1, human and yeast glutaredoxins (human Grx2 and Saccharomyces cerevisiae Grx3), and human ferredoxins. Second-order rate constants for cluster extraction from these holo proteins were also determined by varying the concentration of glutathione, and a likely common mechanism for cluster uptake was determined by kinetic analysis. The results indicate that the [2Fe-2S](GS4) complex is stable under physiological conditions, and demonstrates reversible cluster exchange with a wide range of Fe-S cluster proteins, thereby supporting a possible physiological role for such centers.

Symbolic dynamics of heart rate variability - a promising tool to investigate cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD)?

PubMed

Tonhajzerova, Ingrid; Farsky, Ivan; Mestanik, Michal; Visnovcova, Zuzana; Mestanikova, Andrea; Hrtanek, Igor; Ondrejka, Igor

2016-06-01

We aimed to evaluate complex cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD) by using heart rate variability (HRV) nonlinear analysis - symbolic dynamics. We examined 29 boys with untreated ADHD and 25 healthy boys (age 8-13 years). ADHD symptoms were evaluated by ADHD-RS-IV scale. ECG was recorded in 3 positions: baseline supine position, orthostasis, and clinostasis. Symbolic dynamics indices were used for the assessment of complex cardiac sympathovagal regulation: normalised complexity index (NCI), normalised unpredictability index (NUPI), and pattern classification measures (0V%, 1V%, 2LV%, 2UV%). The results showed that HRV complexity was significantly reduced at rest (NUPI) and during standing position (NCI, NUPI) in ADHD group compared to controls. Cardiac-linked sympathetic index 0V% was significantly higher during all posture positions and cardiovagal index 2LV% was significantly lower to standing in boys suffering from ADHD. Importantly, ADHD symptom inattention positively correlated with 0V%, and negatively correlated with NCI, NUPI. Concluding, symbolic dynamics revealed impaired complex neurocardiac control characterised by potential cardiac beta-adrenergic overactivity and vagal deficiency at rest and to posture changes in boys suffering from ADHD that is correlated with inattention. We suggest that symbolic dynamics indices could represent promising cardiac biomarkers in ADHD.

Effects of distributions of energy of transfer rates on spectral hole burning in photosynthetic pigment-protein complexes

NASA Astrophysics Data System (ADS)

Ahmouda, Somaya

To perform photosynthesis, plants, algae and bacteria possess well organized and closely coupled photosynthetic pigment-protein complexes. Information on energy transfer in photosynthetic complexes is important to understand their functioning and possibly to design new and improved photovoltaic devices. The information on energy transfer processes contained in the narrow zero-phonon lines at low temperatures is hidden under the inhomogeneous broadening. Thus, it has been proven difficult to analyze the spectroscopic properties of these complexes in sufficient detail by conventional spectroscopy methods. In this context the high resolution spectroscopy techniques such as Spectral Hole Burning are powerful tools designed to get around the inhomogeneous broadening. Spectral Hole Burning involves selective excitation by a laser which removes molecules with the zero-phonon transitions resonant with this laser. This thesis focuses on the effects of the distributions of the energy transfer rates (homogeneous line widths) on the evolution of spectral holes. These distributions are a consequence of the static disorder in the photosynthetic pigment-protein complexes. The qualitative effects of different types of the line width distributions on the evolution of spectral holes have been and explored by numerical simulations, an example of analysis of the original experimental data has been presented as well.

Ground-Based Aerosol Measurements | Science Inventory ...

EPA Pesticide Factsheets

Atmospheric particulate matter (PM) is a complex chemical mixture of liquid and solid particles suspended in air (Seinfeld and Pandis 2016). Measurements of this complex mixture form the basis of our knowledge regarding particle formation, source-receptor relationships, data to test and verify complex air quality models, and how PM impacts human health, visibility, global warming, and ecological systems (EPA 2009). Historically, PM samples have been collected on filters or other substrates with subsequent chemical analysis in the laboratory and this is still the major approach for routine networks (Chow 2005; Solomon et al. 2014) as well as in research studies. In this approach, air, at a specified flow rate and time period, is typically drawn through an inlet, usually a size selective inlet, and then drawn through filters, 1 INTRODUCTION Atmospheric particulate matter (PM) is a complex chemical mixture of liquid and solid particles suspended in air (Seinfeld and Pandis 2016). Measurements of this complex mixture form the basis of our knowledge regarding particle formation, source-receptor relationships, data to test and verify complex air quality models, and how PM impacts human health, visibility, global warming, and ecological systems (EPA 2009). Historically, PM samples have been collected on filters or other substrates with subsequent chemical analysis in the laboratory and this is still the major approach for routine networks (Chow 2005; Solomo

Diffusional encounter of barnase and barstar.

PubMed

Spaar, Alexander; Dammer, Christian; Gabdoulline, Razif R; Wade, Rebecca C; Helms, Volkhard

2006-03-15

We present an analysis of trajectories from Brownian dynamics simulations of diffusional protein-protein encounter for the well-studied system of barnase and barstar. This analysis reveals details about the optimal association pathways, the regions of the encounter complex, possible differences of the pathways for dissociation and association, the coupling of translational and rotation motion, and the effect of mutations on the trajectories. We found that a small free-energy barrier divides the energetically most favorable region into a region of the encounter complex above the barnase binding interface and a region around a second energy minimum near the RNA binding loop. When entering the region of the encounter complex from the region near the RNA binding loop, barstar has to change its orientation to increase the electrostatic attraction between the proteins. By concentrating the analysis on the successful binding trajectories, we found that the region of the second minimum is not essential for the binding of barstar to barnase. Nevertheless, this region may be helpful to steer barstar into the region of the encounter complex. When applying the same analysis to several barnase mutants, we found that single mutations may drastically change the free-energy landscape and may significantly alter the population of the two minima. Therefore, certain protein-protein pairs may require careful adaptation of the positions of encounter and transition states when interpreting mutation effects on kinetic rates of association and/or dissociation.

Quantitative semi-automated analysis of morphogenesis with single-cell resolution in complex embryos.

PubMed

Giurumescu, Claudiu A; Kang, Sukryool; Planchon, Thomas A; Betzig, Eric; Bloomekatz, Joshua; Yelon, Deborah; Cosman, Pamela; Chisholm, Andrew D

2012-11-01

A quantitative understanding of tissue morphogenesis requires description of the movements of individual cells in space and over time. In transparent embryos, such as C. elegans, fluorescently labeled nuclei can be imaged in three-dimensional time-lapse (4D) movies and automatically tracked through early cleavage divisions up to ~350 nuclei. A similar analysis of later stages of C. elegans development has been challenging owing to the increased error rates of automated tracking of large numbers of densely packed nuclei. We present Nucleitracker4D, a freely available software solution for tracking nuclei in complex embryos that integrates automated tracking of nuclei in local searches with manual curation. Using these methods, we have been able to track >99% of all nuclei generated in the C. elegans embryo. Our analysis reveals that ventral enclosure of the epidermis is accompanied by complex coordinated migration of the neuronal substrate. We can efficiently track large numbers of migrating nuclei in 4D movies of zebrafish cardiac morphogenesis, suggesting that this approach is generally useful in situations in which the number, packing or dynamics of nuclei present challenges for automated tracking.

Metagenomic analysis of a desulphurisation system used to treat biogas from vinasse methanisation.

PubMed

Dias, Marcela França; Colturato, Luis Felipe; de Oliveira, João Paulo; Leite, Laura Rabelo; Oliveira, Guilherme; Chernicharo, Carlos Augusto; de Araújo, Juliana Calabria

2016-04-01

We investigated the response of microbial community to changes in H2S loading rate in a microaerated desulphurisation system treating biogas from vinasse methanisation. H2S removal efficiency was high, and both COD and DO seemed to be important parameters to biomass activity. DGGE analysis retrieved sequences of sulphide-oxidising bacteria (SOB), such as Thioalkalimicrobium sp. Deep sequencing analysis revealed that the microbial community was complex and remained constant throughout the experiment. Most sequences belonged to Firmicutes and Proteobacteria, and, to a lesser extent, Bacteroidetes, Chloroflexi, and Synergistetes. Despite the high sulphide removal efficiency, the abundance of the taxa of SOB was low, and was negatively affected by the high sulphide loading rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymer producing palladium complexes of unidentate phosphines in the methoxycarbonylation of ethene.

PubMed

Smith, Graeme; Vautravers, Nicolas R; Cole-Hamilton, David J

2009-02-07

A wide range of unidentate phosphines have been studied as ligands for the palladium-catalysed methoxycarbonylation of ethene in the presence of methanesulfonic acid using methanol as the solvent. At high phosphine to Pd ratios, methyl propanoate is formed at a low rate. However, at P-Pd ratios of 4 : 1, some unidentate phosphines promote the formation of polyketone with moderate rates. Analysis of all the phosphines shows that good electron donating power, combined with small size, favours polyketone formation.

An efficient genome-wide association test for multivariate phenotypes based on the Fisher combination function.

PubMed

Yang, James J; Li, Jia; Williams, L Keoki; Buu, Anne

2016-01-05

In genome-wide association studies (GWAS) for complex diseases, the association between a SNP and each phenotype is usually weak. Combining multiple related phenotypic traits can increase the power of gene search and thus is a practically important area that requires methodology work. This study provides a comprehensive review of existing methods for conducting GWAS on complex diseases with multiple phenotypes including the multivariate analysis of variance (MANOVA), the principal component analysis (PCA), the generalizing estimating equations (GEE), the trait-based association test involving the extended Simes procedure (TATES), and the classical Fisher combination test. We propose a new method that relaxes the unrealistic independence assumption of the classical Fisher combination test and is computationally efficient. To demonstrate applications of the proposed method, we also present the results of statistical analysis on the Study of Addiction: Genetics and Environment (SAGE) data. Our simulation study shows that the proposed method has higher power than existing methods while controlling for the type I error rate. The GEE and the classical Fisher combination test, on the other hand, do not control the type I error rate and thus are not recommended. In general, the power of the competing methods decreases as the correlation between phenotypes increases. All the methods tend to have lower power when the multivariate phenotypes come from long tailed distributions. The real data analysis also demonstrates that the proposed method allows us to compare the marginal results with the multivariate results and specify which SNPs are specific to a particular phenotype or contribute to the common construct. The proposed method outperforms existing methods in most settings and also has great applications in GWAS on complex diseases with multiple phenotypes such as the substance abuse disorders.

Molecular analysis and distribution of multidrug-resistant Enterococcus faecium isolates belonging to clonal complex 17 in a tertiary care center in Mexico City

PubMed Central

2013-01-01

Background Enterococcus faecium has recently emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. A high rate of resistance to different antibiotics has been associated with virulent clonal complex 17 isolates carrying the esp and hyl genes and the purK1 allele. Results Twelve clinical vancomycin-resistant Enterococcus faecium (VREF) isolates were obtained from pediatric patients at the Hospital Infantil de México Federico Gómez (HIMFG). Among these VREF isolates, 58.3% (7/12) were recovered from urine, while 41.7% (5/12) were recovered from the bloodstream. The VREF isolates showed a 100% rate of resistance to ampicillin, amoxicillin-clavulanate, ciprofloxacin, clindamycin, chloramphenicol, streptomycin, gentamicin, rifampicin, erythromycin and teicoplanin. In addition, 16.7% (2/12) of the isolates were resistant to linezolid, and 66.7% (8/12) were resistant to tetracycline and doxycycline. PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates, esp in 83.3% (10/12) of the isolates and hyl in 50% (6/12) of the isolates. Phylogenetic analysis via molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and demonstrated 44% similarity among the VREF isolates. MLST analysis identified four different sequence types (ST412, ST757, ST203 and ST612). Conclusion This study provides the first report of multidrug-resistant VREF isolates belonging to clonal complex 17 from a tertiary care center in Mexico City. Multidrug resistance and genetic determinants of virulence confer advantages among VREF in the colonization of their host. Therefore, the prevention and control of the spread of nosocomial infections caused by VREF is crucial for identifying new emergent subclones that could be challenging to treat in subsequent years. PMID:24330424

Evaluation of AA5052 alloy anode in alkaline electrolyte with organic rare-earth complex additives for aluminium-air batteries

NASA Astrophysics Data System (ADS)

Wang, Dapeng; Li, Heshun; Liu, Jie; Zhang, Daquan; Gao, Lixin; Tong, Lin

2015-10-01

Behaviours of the AA5052 aluminium alloy anode of the alkaline aluminium-air battery are studied by the hydrogen evolution test, the electrochemical measurements and the surface analysis method. The combination of amino-acid and rare earth as electrolyte additives effectively retards the self-corrosion of AA5052 aluminium alloy in 4 M NaOH solution. It shows that the combination of L-cysteine and cerium nitrate has a synergistic effect owing to the formation of a complex film on AA5052 alloy surface. The organic rare-earth complex can decrease the anodic polarisation, suppress the hydrogen evolution and increase the anodic utilization rate.

Filter-based multiscale entropy analysis of complex physiological time series.

PubMed

Xu, Yuesheng; Zhao, Liang

2013-08-01

Multiscale entropy (MSE) has been widely and successfully used in analyzing the complexity of physiological time series. We reinterpret the averaging process in MSE as filtering a time series by a filter of a piecewise constant type. From this viewpoint, we introduce filter-based multiscale entropy (FME), which filters a time series to generate multiple frequency components, and then we compute the blockwise entropy of the resulting components. By choosing filters adapted to the feature of a given time series, FME is able to better capture its multiscale information and to provide more flexibility for studying its complexity. Motivated by the heart rate turbulence theory, which suggests that the human heartbeat interval time series can be described in piecewise linear patterns, we propose piecewise linear filter multiscale entropy (PLFME) for the complexity analysis of the time series. Numerical results from PLFME are more robust to data of various lengths than those from MSE. The numerical performance of the adaptive piecewise constant filter multiscale entropy without prior information is comparable to that of PLFME, whose design takes prior information into account.

Renormalization group approach to power-law modeling of complex metabolic networks.

PubMed

Hernández-Bermejo, Benito

2010-08-07

In the modeling of complex biological systems, and especially in the framework of the description of metabolic pathways, the use of power-law models (such as S-systems and GMA systems) often provides a remarkable accuracy over several orders of magnitude in concentrations, an unusually broad range not fully understood at present. In order to provide additional insight in this sense, this article is devoted to the renormalization group analysis of reactions in fractal or self-similar media. In particular, the renormalization group methodology is applied to the investigation of how rate-laws describing such reactions are transformed when the geometric scale is changed. The precise purpose of such analysis is to investigate whether or not power-law rate-laws present some remarkable features accounting for the successes of power-law modeling. As we shall see, according to the renormalization group point of view the answer is positive, as far as power-laws are the critical solutions of the renormalization group transformation, namely power-law rate-laws are the renormalization group invariant solutions. Moreover, it is shown that these results also imply invariance under the group of concentration scalings, thus accounting for the reported power-law model accuracy over several orders of magnitude in metabolite concentrations. Copyright 2010 Elsevier Ltd. All rights reserved.

A Wearable Microfluidic Sensing Patch for Dynamic Sweat Secretion Analysis.

PubMed

Nyein, Hnin Yin Yin; Tai, Li-Chia; Ngo, Quynh Phuong; Chao, Minghan; Zhang, George B; Gao, Wei; Bariya, Mallika; Bullock, James; Kim, Hyungjin; Fahad, Hossain M; Javey, Ali

2018-05-25

Wearable sweat sensing is a rapidly rising research area driven by its promising potential in health, fitness, and diagnostic applications. Despite the growth in the field, major challenges in relation to sweat metrics remain to be addressed. These challenges include sweat rate monitoring for its complex relation with sweat compositions and sweat sampling for sweat dynamics studies. In this work, we present a flexible microfluidic sweat sensing patch that enhances real-time electrochemical sensing and sweat rate analysis via sweat sampling. The device contains a spiral-patterned microfluidic component that is embedded with ion-selective sensors and an electrical impedance-based sweat rate sensor on a flexible plastic substrate. The patch is enabled to autonomously perform sweat analysis by interfacing the sensing component with a printed circuit board that is capable of on-site signal conditioning, analysis, and transmission. Progressive sweat flow in the microfluidic device, governed by the pressure induced by the secreted sweat, enhances sweat sampling and electrochemical detection via a defined sweat collection chamber and a directed sweat route. The characteristic of the sweat rate sensor is validated through a theoretical simulation, and the precision and accuracy of the flow rate is verified with a commercial syringe pump and a Macroduct sweat collector. On-body simultaneous monitoring of ion (H + , Na + , K + , Cl - ) concentration and sweat rate is also demonstrated for sensor functionality. This sweat sensing patch provides an integrated platform for a comprehensive sweat secretion analysis and facilitates physiological and clinical investigations by closely monitoring interrelated sweat parameters.

A model of clutter for complex, multivariate geospatial displays.

PubMed

Lohrenz, Maura C; Trafton, J Gregory; Beck, R Melissa; Gendron, Marlin L

2009-02-01

A novel model of measuring clutter in complex geospatial displays was compared with human ratings of subjective clutter as a measure of convergent validity. The new model is called the color-clustering clutter (C3) model. Clutter is a known problem in displays of complex data and has been shown to affect target search performance. Previous clutter models are discussed and compared with the C3 model. Two experiments were performed. In Experiment 1, participants performed subjective clutter ratings on six classes of information visualizations. Empirical results were used to set two free parameters in the model. In Experiment 2, participants performed subjective clutter ratings on aeronautical charts. Both experiments compared and correlated empirical data to model predictions. The first experiment resulted in a .76 correlation between ratings and C3. The second experiment resulted in a .86 correlation, significantly better than results from a model developed by Rosenholtz et al. Outliers to our correlation suggest further improvements to C3. We suggest that (a) the C3 model is a good predictor of subjective impressions of clutter in geospatial displays, (b) geospatial clutter is a function of color density and saliency (primary C3 components), and (c) pattern analysis techniques could further improve C3. The C3 model could be used to improve the design of electronic geospatial displays by suggesting when a display will be too cluttered for its intended audience.

Canadian experience with the pipeline embolization device for repair of unruptured intracranial aneurysms.

PubMed

O'Kelly, C J; Spears, J; Chow, M; Wong, J; Boulton, M; Weill, A; Willinsky, R A; Kelly, M; Marotta, T R

2013-02-01

Flow-diverting stents, such as the PED, have emerged as a novel means of treating complex intracranial aneurysms. This retrospective analysis of the initial Canadian experience provides insight into technical challenges, clinical and radiographic outcomes, and complication rates after the use of flow-diverting stents for unruptured aneurysms. Cases were compiled from 7 Canadian centers between July 2008 and December 2010. Each center prospectively tracked their initial experience; these data were retrospectively updated and pooled for analysis. During the defined study period, 97 cases of unruptured aneurysm were treated with the PED, with successful stent deployment in 94 cases. The overall complete or near-complete occlusion rate was 83%, with a median follow-up at 1.25 years (range 0.25-2.5 years). Progressive occlusion was witnessed over time, with complete or near-complete occlusion in 65% of aneurysms followed through 6 months, and 90% of aneurysms followed through 1 year. Multivariate analysis found previous aneurysm treatment and female sex predictive of persistent aneurysm filling. Most patients were stable or improved (88%), with the most favorable outcomes observed in patients with cavernous carotid aneurysms. The overall mortality rate was 6%. Postprocedural aneurysm hemorrhage occurred in 3 patients (3%), while ipsilateral distal territory hemorrhage was observed in 4 patients (3.4%). Flow-diverting stents represent an important tool in the treatment of complex intracranial aneurysms. The relative efficacy and morbidity of this treatment must be considered in the context of available alternate interventions.

Comparison of colorimetry and electrothermal atomic absorption spectroscopy for the quantification of non-transferrin bound iron in human sera.

PubMed

Jittangprasert, Piyada; Wilairat, Prapin; Pootrakul, Pensri

2004-12-01

This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand for binding iron from low molecular weight iron complexes present in the serum but without removing iron from the transferrin protein. After ultrafiltration the Fe (III)-NTA complex was then quantified by both methods. Kinetic study of the rate of the Fe (II)-BPT complex formation for various excess amounts of NTA ligand was also carried out. The kinetic data show that a minimum time duration (> 60 minutes) is necessary for complete complex formation when large excess of NTA is used. Calibration curves given by colorimetric and ETAAS methods were linear over the range of 0.15-20 microM iron (III). The colorimetric and ETAAS methods exhibited detection limit (3sigma) of 0.13 and 0.14 microM, respectively. The NTBI concentrations from 55 thalassemic serum samples measured employing BPT as chromogen were statistically compared with the results determined by ETAAS. No significant disagreement at 95% confidence level was observed. It is, therefore, possible to select any one of these two techniques for determination of NTBI in serum samples of thalassemic patients. However, the colorimetric procedure requires a longer analysis time because of a slow rate of exchange of NTA ligand with BPT, leading to the slow rate of formation of the colored complex.

Humans' perceptions of animal mentality: ascriptions of thinking.

PubMed

Rasmussen, J L; Rajecki, D W; Craft, H D

1993-09-01

On rating scales, 294 students indicated whether it was reasonable to say that a dog, cat, bird, fish, and school-age child had the capacity for 12 commonplace human mental operations or experiences. Factor analysis of responses identified 2 levels of attributions, simple thinking and complex thinking. The child and all animals were credited with simple thinking, but respondents were much more likely to ascribe complex thinking to the child. (A pilot study with 8 animal-behavior professionals generally replicated these results.) Certain mental categories (e.g., emotion) were judged by students to be simple for all target types; others (e.g., conservation) were judged to be universally complex. Further factoring revealed articulate ascriptions for key mental categories. Play and imagine was seen as simple in the animals but complex for the child, but enumeration and sorting and dream were seen as simple in the child but complex for the animals.

Influence of dose rate on the induction of simple and complex chromosome exchanges by gamma rays.

PubMed

Loucas, Bradford D; Eberle, Richard; Bailey, Susan M; Cornforth, Michael N

2004-10-01

Single-color painting of whole chromosomes, or protocols in which only a few chromosomes are distinctively painted, will always fail to detect a proportion of complex exchanges because they frequently produce pseudosimple painting patterns that are indistinguishable from those produced by bona fide simple exchanges. When 24-color multi-fluor FISH (mFISH) was employed for the purpose of distinguishing (truly) simple from pseudosimple exchanges, it was confirmed that the acute low-LET radiation dose-response relationship for simple exchanges lacked significant upward curvature. This result has been interpreted to indicate that the formation of simple exchanges requires only one chromosome locus be damaged (e.g. broken) by radiation to initiate an exchange-not two, as classical cytogenetic theory maintains. Because a one-lesion mechanism implies single-track action, it follows that the production of simple exchanges should not be influenced by changes in dose rate. To examine this prediction, we irradiated noncycling primary human fibroblasts with graded doses of (137)Cs gamma rays at an acute dose rate of 1.10 Gy/min and compared, using mFISH, the yield of simple exchanges to that observed after exposure to the same radiation delivered at a chronic dose rate of 0.08 cGy/min. The shape of the dose response was found to be quasi-linear for both dose rates, but, counter to providing support for a one-lesion mechanism, the yield of simple aberrations was greatly reduced by protracted exposure. Although chronic doses were delivered at rates low enough to produce damage exclusively by single-track action, this did not altogether eliminate the formation of complex aberrations, an analysis of which leads to the conclusion that a single track of low-LET radiation is capable of inducing complex exchanges requiring up to four proximate breaks for their formation. For acute exposures, the ratio of simple reciprocal translocations to simple dicentrics was near unity.

Visual Complexity and Affect: Ratings Reflect More Than Meets the Eye.

PubMed

Madan, Christopher R; Bayer, Janine; Gamer, Matthias; Lonsdorf, Tina B; Sommer, Tobias

2017-01-01

Pictorial stimuli can vary on many dimensions, several aspects of which are captured by the term 'visual complexity.' Visual complexity can be described as, "a picture of a few objects, colors, or structures would be less complex than a very colorful picture of many objects that is composed of several components." Prior studies have reported a relationship between affect and visual complexity, where complex pictures are rated as more pleasant and arousing. However, a relationship in the opposite direction, an effect of affect on visual complexity, is also possible; emotional arousal and valence are known to influence selective attention and visual processing. In a series of experiments, we found that ratings of visual complexity correlated with affective ratings, and independently also with computational measures of visual complexity. These computational measures did not correlate with affect, suggesting that complexity ratings are separately related to distinct factors. We investigated the relationship between affect and ratings of visual complexity, finding an 'arousal-complexity bias' to be a robust phenomenon. Moreover, we found this bias could be attenuated when explicitly indicated but did not correlate with inter-individual difference measures of affective processing, and was largely unrelated to cognitive and eyetracking measures. Taken together, the arousal-complexity bias seems to be caused by a relationship between arousal and visual processing as it has been described for the greater vividness of arousing pictures. The described arousal-complexity bias is also of relevance from an experimental perspective because visual complexity is often considered a variable to control for when using pictorial stimuli.

Visual Complexity and Affect: Ratings Reflect More Than Meets the Eye

PubMed Central

Madan, Christopher R.; Bayer, Janine; Gamer, Matthias; Lonsdorf, Tina B.; Sommer, Tobias

2018-01-01

Pictorial stimuli can vary on many dimensions, several aspects of which are captured by the term ‘visual complexity.’ Visual complexity can be described as, “a picture of a few objects, colors, or structures would be less complex than a very colorful picture of many objects that is composed of several components.” Prior studies have reported a relationship between affect and visual complexity, where complex pictures are rated as more pleasant and arousing. However, a relationship in the opposite direction, an effect of affect on visual complexity, is also possible; emotional arousal and valence are known to influence selective attention and visual processing. In a series of experiments, we found that ratings of visual complexity correlated with affective ratings, and independently also with computational measures of visual complexity. These computational measures did not correlate with affect, suggesting that complexity ratings are separately related to distinct factors. We investigated the relationship between affect and ratings of visual complexity, finding an ‘arousal-complexity bias’ to be a robust phenomenon. Moreover, we found this bias could be attenuated when explicitly indicated but did not correlate with inter-individual difference measures of affective processing, and was largely unrelated to cognitive and eyetracking measures. Taken together, the arousal-complexity bias seems to be caused by a relationship between arousal and visual processing as it has been described for the greater vividness of arousing pictures. The described arousal-complexity bias is also of relevance from an experimental perspective because visual complexity is often considered a variable to control for when using pictorial stimuli. PMID:29403412

Complexity growth in massive gravity theories, the effects of chirality, and more

NASA Astrophysics Data System (ADS)

Ghodrati, Mahdis

2017-11-01

To study the effect of parity violation on the rate of complexity growth, by using "complexity=action " conjecture, we find the complexity growth rates in different solutions of the chiral theory of topologically massive gravity (TMG) and parity-preserving theory of new massive gravity (NMG). Using the results, one can see that decreasing the parameter μ , which increases the effect of the Chern-Simons term and increases chirality, would increase the rate of growth of complexity. Also one can observe a stronger correlation between complexity growth and temperature rather than complexity growth and entropy. At the end we comment on the possible meaning of the deforming term of chiral Liouville action for the rate of complexity growth of warped conformal field theories in the tensor network renormalization picture.

Effects of lability of metal complex on free ion measurement using DMT.

PubMed

Weng, Liping; Van Riemsdijk, Willem H; Temminghoff, Erwin J M

2010-04-01

Very low concentrations of free metal ion in natural samples can be measured using the Donnan membrane technique (DMT) based on ion transport kinetics. In this paper, the possible effects of slow dissociation of metal complexes on the interpretation of kinetic DMT are investigated both theoretically and experimentally. The expressions of the lability parameter, Lgrangian , were derived for DMT. Analysis of new experimental studies using synthetic solution containing NTA as the ligand and Cu(2+) ions shows that when the ionic strength is low (

An Analogy Using Pennies and Dimes to Explain Chemical Kinetics Concepts

ERIC Educational Resources Information Center

Cortes-Figueroa, Jose E.; Perez, Wanda I.; Lopez, Jose R.; Moore-Russo, Deborah A.

2011-01-01

In this article, the authors present an analogy that uses coins and graphical analysis to teach kinetics concepts and resolve pseudo-first-order rate constants related to transition-metal complexes ligand-solvent exchange reactions. They describe an activity that is directed to upper-division undergraduate and graduate students. The activity…

Estimation of beech pyrolysis kinetic parameters by Shuffled Complex Evolution.

PubMed

Ding, Yanming; Wang, Changjian; Chaos, Marcos; Chen, Ruiyu; Lu, Shouxiang

2016-01-01

The pyrolysis kinetics of a typical biomass energy feedstock, beech, was investigated based on thermogravimetric analysis over a wide heating rate range from 5K/min to 80K/min. A three-component (corresponding to hemicellulose, cellulose and lignin) parallel decomposition reaction scheme was applied to describe the experimental data. The resulting kinetic reaction model was coupled to an evolutionary optimization algorithm (Shuffled Complex Evolution, SCE) to obtain model parameters. To the authors' knowledge, this is the first study in which SCE has been used in the context of thermogravimetry. The kinetic parameters were simultaneously optimized against data for 10, 20 and 60K/min heating rates, providing excellent fits to experimental data. Furthermore, it was shown that the optimized parameters were applicable to heating rates (5 and 80K/min) beyond those used to generate them. Finally, the predicted results based on optimized parameters were contrasted with those based on the literature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interactive effects of soil acidity and fluoride on soil solution aluminium chemistry and barley (Hordeum vulgare L.) root growth.

PubMed

Manoharan, V; Loganathan, P; Tillman, R W; Parfitt, R L

2007-02-01

A greenhouse study was conducted to determine if concentrations of fluoride (F), which would be added to acid soils via P fertilisers, were detrimental to barley root growth. Increasing rates of F additions to soil significantly increased the soil solution concentrations of aluminium (Al) and F irrespective of the initial adjusted soil pH, which ranged from 4.25 to 5.48. High rates of F addition severely restricted root growth; the effect was more pronounced in the strongly acidic soil. Speciation calculations demonstrated that increasing rates of F additions substantially increased the concentrations of Al-F complexes in the soil. Stepwise regression analysis showed that it was the combination of the activities of AlF2(1+) and AlF(2+) complexes that primarily controlled barley root growth. The results suggested that continuous input of F to soils, and increased soil acidification, may become an F risk issue in the future.

A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures.

PubMed

Agarwal, Prateek; Abdullah, Kalil G; Ramayya, Ashwin G; Nayak, Nikhil R; Lucas, Timothy H

2017-06-29

Reversal of therapeutic anticoagulation prior to emergency neurosurgical procedures is required in the setting of intracranial hemorrhage. Multifactor prothrombin complex concentrate (PCC) promises rapid efficacy but may increase the probability of thrombotic complications compared to fresh frozen plasma (FFP). To compare the rate of thrombotic complications in patients treated with PCC or FFP to reverse therapeutic anticoagulation prior to emergency neurosurgical procedures in the setting of intracranial hemorrhage at a level I trauma center. Sixty-three consecutive patients on warfarin therapy presenting with intracranial hemorrhage who received anticoagulation reversal prior to emergency neurosurgical procedures were retrospectively identified between 2007 and 2016. They were divided into 2 cohorts based on reversal agent, either PCC (n = 28) or FFP (n = 35). The thrombotic complications rates within 72 h of reversal were compared using the χ 2 test. A multivariate propensity score matching analysis was used to limit the threat to interval validity from selection bias arising from differences in demographics, laboratory values, history, and clinical status. Thrombotic complications were uncommon in this neurosurgical population, occurring in 1.59% (1/63) of treated patients. There was no significant difference in the thrombotic complication rate between groups, 3.57% (1/28; PCC group) vs 0% (0/35; FFP group). Propensity score matching analysis validated this finding after controlling for any selection bias. In this limited sample, thrombotic complication rates were similar between use of PCC and FFP for anticoagulation reversal in the management of intracranial hemorrhage prior to emergency neurosurgical procedures. Copyright © 2017 by the Congress of Neurological Surgeons

Scaling behavior of online human activity

NASA Astrophysics Data System (ADS)

Zhao, Zhi-Dan; Cai, Shi-Min; Huang, Junming; Fu, Yan; Zhou, Tao

2012-11-01

The rapid development of the Internet technology enables humans to explore the web and record the traces of online activities. From the analysis of these large-scale data sets (i.e., traces), we can get insights about the dynamic behavior of human activity. In this letter, the scaling behavior and complexity of human activity in the e-commerce, such as music, books, and movies rating, are comprehensively investigated by using the detrended fluctuation analysis technique and the multiscale entropy method. Firstly, the interevent time series of rating behaviors of these three types of media show similar scaling properties with exponents ranging from 0.53 to 0.58, which implies that the collective behaviors of rating media follow a process embodying self-similarity and long-range correlation. Meanwhile, by dividing the users into three groups based on their activities (i.e., rating per unit time), we find that the scaling exponents of the interevent time series in the three groups are different. Hence, these results suggest that a stronger long-range correlations exist in these collective behaviors. Furthermore, their information complexities vary in the three groups. To explain the differences of the collective behaviors restricted to the three groups, we study the dynamic behavior of human activity at the individual level, and find that the dynamic behaviors of a few users have extremely small scaling exponents associated with long-range anticorrelations. By comparing the interevent time distributions of four representative users, we can find that the bimodal distributions may bring forth the extraordinary scaling behaviors. These results of the analysis of the online human activity in the e-commerce may not only provide insight into its dynamic behaviors but may also be applied to acquire potential economic interest.

Development and optimization of SPE-HPLC-UV/ELSD for simultaneous determination of nine bioactive components in Shenqi Fuzheng Injection based on Quality by Design principles.

PubMed

Wang, Lu; Qu, Haibin

2016-03-01

A method combining solid phase extraction, high performance liquid chromatography, and ultraviolet/evaporative light scattering detection (SPE-HPLC-UV/ELSD) was developed according to Quality by Design (QbD) principles and used to assay nine bioactive compounds within a botanical drug, Shenqi Fuzheng Injection. Risk assessment and a Plackett-Burman design were utilized to evaluate the impact of 11 factors on the resolutions and signal-to-noise of chromatographic peaks. Multiple regression and Pareto ranking analysis indicated that the sorbent mass, sample volume, flow rate, column temperature, evaporator temperature, and gas flow rate were statistically significant (p < 0.05) in this procedure. Furthermore, a Box-Behnken design combined with response surface analysis was employed to study the relationships between the quality of SPE-HPLC-UV/ELSD analysis and four significant factors, i.e., flow rate, column temperature, evaporator temperature, and gas flow rate. An analytical design space of SPE-HPLC-UV/ELSD was then constructed by calculated Monte Carlo probability. In the presented approach, the operating parameters of sample preparation, chromatographic separation, and compound detection were investigated simultaneously. Eight terms of method validation, i.e., system-suitability tests, method robustness/ruggedness, sensitivity, precision, repeatability, linearity, accuracy, and stability, were accomplished at a selected working point. These results revealed that the QbD principles were suitable in the development of analytical procedures for samples in complex matrices. Meanwhile, the analytical quality and method robustness were validated by the analytical design space. The presented strategy provides a tutorial on the development of a robust QbD-compliant quantitative method for samples in complex matrices.

Mass spectrometric screening of ligands with lower off-rate from a clicked-based pooled library.

PubMed

Arai, Satoshi; Hirosawa, Shota; Oguchi, Yusuke; Suzuki, Madoka; Murata, Atsushi; Ishiwata, Shin'ichi; Takeoka, Shinji

2012-08-13

This paper describes a convenient screening method using ion trap electrospray ionization mass spectrometry to classify ligands to a target molecule in terms of kinetic parameters. We demonstrate this method in the screening of ligands to a hexahistidine tag from a pooled library synthesized by click chemistry. The ion trap mass spectrometry analysis revealed that higher stabilities of ligand-target complexes in the gas phase were related to lower dissociation rate constants, i.e., off-rates in solution. Finally, we prepared a fluorescent probe utilizing the ligand with lowest off-rate and succeeded in performing single molecule observations of hexahistidine-tagged myosin V walking on actin filaments.

Conditional Probabilities of Large Earthquake Sequences in California from the Physics-based Rupture Simulator RSQSim

NASA Astrophysics Data System (ADS)

Gilchrist, J. J.; Jordan, T. H.; Shaw, B. E.; Milner, K. R.; Richards-Dinger, K. B.; Dieterich, J. H.

2017-12-01

Within the SCEC Collaboratory for Interseismic Simulation and Modeling (CISM), we are developing physics-based forecasting models for earthquake ruptures in California. We employ the 3D boundary element code RSQSim (Rate-State Earthquake Simulator of Dieterich & Richards-Dinger, 2010) to generate synthetic catalogs with tens of millions of events that span up to a million years each. This code models rupture nucleation by rate- and state-dependent friction and Coulomb stress transfer in complex, fully interacting fault systems. The Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) fault and deformation models are used to specify the fault geometry and long-term slip rates. We have employed the Blue Waters supercomputer to generate long catalogs of simulated California seismicity from which we calculate the forecasting statistics for large events. We have performed probabilistic seismic hazard analysis with RSQSim catalogs that were calibrated with system-wide parameters and found a remarkably good agreement with UCERF3 (Milner et al., this meeting). We build on this analysis, comparing the conditional probabilities of sequences of large events from RSQSim and UCERF3. In making these comparisons, we consider the epistemic uncertainties associated with the RSQSim parameters (e.g., rate- and state-frictional parameters), as well as the effects of model-tuning (e.g., adjusting the RSQSim parameters to match UCERF3 recurrence rates). The comparisons illustrate how physics-based rupture simulators might assist forecasters in understanding the short-term hazards of large aftershocks and multi-event sequences associated with complex, multi-fault ruptures.

Performance evaluation of hospitals that provide care in the public health system, Brazil.

PubMed

Ramos, Marcelo Cristiano de Azevedo; da Cruz, Lucila Pedroso; Kishima, Vanessa Chaer; Pollara, Wilson Modesto; de Lira, Antônio Carlos Onofre; Couttolenc, Bernard François

2015-01-01

OBJECTIVE To analyze if size, administrative level, legal status, type of unit and educational activity influence the hospital network performance in providing services to the Brazilian Unified Health System. METHODS This cross-sectional study evaluated data from the Hospital Information System and the Cadastro Nacional de Estabelecimentos de Saúde (National Registry of Health Facilities), 2012, in Sao Paulo, Southeastern Brazil. We calculated performance indicators, such as: the ratio of hospital employees per bed; mean amount paid for admission; bed occupancy rate; average length of stay; bed turnover index and hospital mortality rate. Data were expressed as mean and standard deviation. The groups were compared using analysis of variance (ANOVA) and Bonferroni correction. RESULTS The hospital occupancy rate in small hospitals was lower than in medium, big and special-sized hospitals. Higher hospital occupancy rate and bed turnover index were observed in hospitals that include education in their activities. The hospital mortality rate was lower in specialized hospitals compared to general ones, despite their higher proportion of highly complex admissions. We found no differences between hospitals in the direct and indirect administration for most of the indicators analyzed. CONCLUSIONS The study indicated the importance of the scale effect on efficiency, and larger hospitals had a higher performance. Hospitals that include education in their activities had a higher operating performance, albeit with associated importance of using human resources and highly complex structures. Specialized hospitals had a significantly lower rate of mortality than general hospitals, indicating the positive effect of the volume of procedures and technology used on clinical outcomes. The analysis related to the administrative level and legal status did not show any significant performance differences between the categories of public hospitals.

Approximate Bayesian estimation of extinction rate in the Finnish Daphnia magna metapopulation.

PubMed

Robinson, John D; Hall, David W; Wares, John P

2013-05-01

Approximate Bayesian computation (ABC) is useful for parameterizing complex models in population genetics. In this study, ABC was applied to simultaneously estimate parameter values for a model of metapopulation coalescence and test two alternatives to a strict metapopulation model in the well-studied network of Daphnia magna populations in Finland. The models shared four free parameters: the subpopulation genetic diversity (θS), the rate of gene flow among patches (4Nm), the founding population size (N0) and the metapopulation extinction rate (e) but differed in the distribution of extinction rates across habitat patches in the system. The three models had either a constant extinction rate in all populations (strict metapopulation), one population that was protected from local extinction (i.e. a persistent source), or habitat-specific extinction rates drawn from a distribution with specified mean and variance. Our model selection analysis favoured the model including a persistent source population over the two alternative models. Of the closest 750,000 data sets in Euclidean space, 78% were simulated under the persistent source model (estimated posterior probability = 0.769). This fraction increased to more than 85% when only the closest 150,000 data sets were considered (estimated posterior probability = 0.774). Approximate Bayesian computation was then used to estimate parameter values that might produce the observed set of summary statistics. Our analysis provided posterior distributions for e that included the point estimate obtained from previous data from the Finnish D. magna metapopulation. Our results support the use of ABC and population genetic data for testing the strict metapopulation model and parameterizing complex models of demography. © 2013 Blackwell Publishing Ltd.

Performance evaluation of hospitals that provide care in the public health system, Brazil

PubMed Central

Ramos, Marcelo Cristiano de Azevedo; da Cruz, Lucila Pedroso; Kishima, Vanessa Chaer; Pollara, Wilson Modesto; de Lira, Antônio Carlos Onofre; Couttolenc, Bernard François

2015-01-01

OBJECTIVE To analyze if size, administrative level, legal status, type of unit and educational activity influence the hospital network performance in providing services to the Brazilian Unified Health System. METHODS This cross-sectional study evaluated data from the Hospital Information System and the Cadastro Nacional de Estabelecimento s de Saúde (National Registry of Health Facilities), 2012, in Sao Paulo, Southeastern Brazil. We calculated performance indicators, such as: the ratio of hospital employees per bed; mean amount paid for admission; bed occupancy rate; average length of stay; bed turnover index and hospital mortality rate. Data were expressed as mean and standard deviation. The groups were compared using analysis of variance (ANOVA) and Bonferroni correction. RESULTS The hospital occupancy rate in small hospitals was lower than in medium, big and special-sized hospitals. Higher hospital occupancy rate and bed turnover index were observed in hospitals that include education in their activities. The hospital mortality rate was lower in specialized hospitals compared to general ones, despite their higher proportion of highly complex admissions. We found no differences between hospitals in the direct and indirect administration for most of the indicators analyzed. CONCLUSIONS The study indicated the importance of the scale effect on efficiency, and larger hospitals had a higher performance. Hospitals that include education in their activities had a higher operating performance, albeit with associated importance of using human resources and highly complex structures. Specialized hospitals had a significantly lower rate of mortality than general hospitals, indicating the positive effect of the volume of procedures and technology used on clinical outcomes. The analysis related to the administrative level and legal status did not show any significant performance differences between the categories of public hospitals. PMID:26247385

[Design of a Front-end Device of Heart Rate Variability Analysis System Based on Photoplethysmography].

PubMed

Shi, Lei; Sun, Peng; Pang, Yu; Luo, Zhiyong; Wang, Wei; Wang, Yanxiang

2016-02-01

Heart rate variability (HRV) is the difference between the successive changes in the heartbeat cycle, and it is produced in the autonomic nervous system modulation of the sinus node of the heart. The HRV is a valuable indicator in predicting the sudden cardiac death and arrhythmic events. Traditional analysis of HRV is based on a multielectrocardiogram (ECG), but the ECG signal acquisition is complex, so we have designed an HRV analysis system based on photoplethysmography (PPG). PPG signal is collected by a microcontroller from human's finger, and it is sent to the terminal via USB-Serial module. The terminal software not only collects the data and plot waveforms, but also stores the data for future HRV analysis. The system is small in size, low in power consumption, and easy for operation. It is suitable for daily care no matter whether it is used at home or in a hospital.

Search algorithm complexity modeling with application to image alignment and matching

NASA Astrophysics Data System (ADS)

DelMarco, Stephen

2014-05-01

Search algorithm complexity modeling, in the form of penetration rate estimation, provides a useful way to estimate search efficiency in application domains which involve searching over a hypothesis space of reference templates or models, as in model-based object recognition, automatic target recognition, and biometric recognition. The penetration rate quantifies the expected portion of the database that must be searched, and is useful for estimating search algorithm computational requirements. In this paper we perform mathematical modeling to derive general equations for penetration rate estimates that are applicable to a wide range of recognition problems. We extend previous penetration rate analyses to use more general probabilistic modeling assumptions. In particular we provide penetration rate equations within the framework of a model-based image alignment application domain in which a prioritized hierarchical grid search is used to rank subspace bins based on matching probability. We derive general equations, and provide special cases based on simplifying assumptions. We show how previously-derived penetration rate equations are special cases of the general formulation. We apply the analysis to model-based logo image alignment in which a hierarchical grid search is used over a geometric misalignment transform hypothesis space. We present numerical results validating the modeling assumptions and derived formulation.

Thermodynamic Analysis of Chemically Reacting Mixtures-Comparison of First and Second Order Models.

PubMed

Pekař, Miloslav

2018-01-01

Recently, a method based on non-equilibrium continuum thermodynamics which derives thermodynamically consistent reaction rate models together with thermodynamic constraints on their parameters was analyzed using a triangular reaction scheme. The scheme was kinetically of the first order. Here, the analysis is further developed for several first and second order schemes to gain a deeper insight into the thermodynamic consistency of rate equations and relationships between chemical thermodynamic and kinetics. It is shown that the thermodynamic constraints on the so-called proper rate coefficient are usually simple sign restrictions consistent with the supposed reaction directions. Constraints on the so-called coupling rate coefficients are more complex and weaker. This means more freedom in kinetic coupling between reaction steps in a scheme, i.e., in the kinetic effects of other reactions on the rate of some reaction in a reacting system. When compared with traditional mass-action rate equations, the method allows a reduction in the number of traditional rate constants to be evaluated from data, i.e., a reduction in the dimensionality of the parameter estimation problem. This is due to identifying relationships between mass-action rate constants (relationships which also include thermodynamic equilibrium constants) which have so far been unknown.

Investigating Reports of Complex Regional Pain Syndrome: An Analysis of HPV-16/18-Adjuvanted Vaccine Post-Licensure Data

PubMed Central

Huygen, Frank; Verschueren, Kristin; McCabe, Candida; Stegmann, Jens-Ulrich; Zima, Julia; Mahaux, Olivia; Van Holle, Lionel; Angelo, Maria-Genalin

2015-01-01

Complex regional pain syndrome (CRPS) is a chronic pain disorder that typically follows trauma or surgery. Suspected CRPS reported after vaccination with human papillomavirus (HPV) vaccines led to temporary suspension of proactive recommendation of HPV vaccination in Japan. We investigated the potential CRPS signal in relation to HPV-16/18-adjuvanted vaccine (Cervarix®) by database review of CRPS cases with independent expert confirmation; a disproportionality analysis and analyses of temporality; an observed versus expected analysis using published background incidence rates; systematic reviews of aggregate safety data, and a literature review. The analysis included 17 case reports of CRPS: 10 from Japan (0.14/100,000 doses distributed) and seven from the United Kingdom (0.08/100,000). Five cases were considered by independent experts to be confirmed CRPS. Quantitative analyses did not suggest an association between CRPS and HPV-16/18-adjuvanted vaccine. Observed CRPS incidence after HPV-16/18 vaccination was statistically significantly below expected rates. Systematic database reviews using search terms varying in specificity and sensitivity did not identify new cases. No CRPS was reported during clinical development and no unexpected results found in the literature. There is not sufficient evidence to suggest an increased risk of developing CRPS following vaccination with HPV-16/18-adjuvanted vaccine. Post-licensure safety surveillance confirms the acceptable benefit-risk of HPV-16/18 vaccination. PMID:26501109

Reliable Real-time Calculation of Heart-rate Complexity in Critically Ill Patients Using Multiple Noisy Waveform Sources

DTIC Science & Technology

2014-01-01

systems Machine learning Automatic data processing 1 Introduction Heart-rate complexity (HRC) is a method of quantifying the amount of complex...5. Batchinsky AI, Skinner J, Necsoiu C, et al. New measures of heart-rate complexity: effect of chest trauma and hemorrhage. J Trauma. 2010;68:1178–85

Perturbation solutions of combustion instability problems

NASA Technical Reports Server (NTRS)

Googerdy, A.; Peddieson, J., Jr.; Ventrice, M.

1979-01-01

A method involving approximate modal analysis using the Galerkin method followed by an approximate solution of the resulting modal-amplitude equations by the two-variable perturbation method (method of multiple scales) is applied to two problems of pressure-sensitive nonlinear combustion instability in liquid-fuel rocket motors. One problem exhibits self-coupled instability while the other exhibits mode-coupled instability. In both cases it is possible to carry out the entire linear stability analysis and significant portions of the nonlinear stability analysis in closed form. In the problem of self-coupled instability the nonlinear stability boundary and approximate forms of the limit-cycle amplitudes and growth and decay rates are determined in closed form while the exact limit-cycle amplitudes and growth and decay rates are found numerically. In the problem of mode-coupled instability the limit-cycle amplitudes are found in closed form while the growth and decay rates are found numerically. The behavior of the solutions found by the perturbation method are in agreement with solutions obtained using complex numerical methods.

[Analysis of Foetal Heart Rate Data using Complex Software: Comparison of Recurrence Plot of Foetal Heart Rate with the Course of Pregnancy -].

PubMed

Jörn, H; Morgenstern, B; Wassenberg, B; Rath, W

2004-08-01

Is it useful to further analyse foetal heart rate to improve the prediction of pregnancy complications? The analysis of the foetal heart rate is usually based on the variability of the heart rate, i. e. the more variable the heart rate presents - except a decrease - the better the condition of the foetus is. The same concept is applied in our own analysis which differs only in the presentation of the data. We analysed 25 non-stress-tests from unselected third trimester pregnancies using sophisticated software. The recurrence plot (RP) is able to rearrange data from foetal heart rate monitoring in order to make the heart rate variability visible. We developed criteria for a normal and an abnormal test result describing the structure of the diagram to predict an uneventful and a high-risk pregnancy, respectively. 11 out of 11 patients with uneventful course and outcome of pregnancy showed a coarse and blurred RP pattern. 12 out of 14 (86 %) patients developing either intrauterine growth retardation or preeclampsia and requiring caesarean section because of foetal heart rate abnormalities showed a fine and clear RP pattern. Our preliminary results show that it makes sense to further evaluate foetal heart rate variability in order to predict pregnancy complications. Computer programs including the algorithms needed (calculation of the recurrence plot) are not expensive and easy to handle. A widespread use of these programs represents the basis requirement for large controlled clinical trials.

Beyond the conventional understanding of water-rock reactivity

NASA Astrophysics Data System (ADS)

Fischer, Cornelius; Luttge, Andreas

2017-01-01

A common assumption is that water-rock reaction rates should converge to a mean value. There is, however, an emerging consensus on the genuine nature of reaction rate variations under identical chemical conditions. Thus, the further use of mean reaction rates for the prediction of material fluxes is environmentally and economically risky, manifest for example in the management of nuclear waste or the evolution of reservoir rocks. Surface-sensitive methods and resulting information about heterogeneous surface reactivity illustrate the inherent rate variability. Consequently, a statistical analysis was developed in order to quantify the heterogeneity of surface rates. We show how key components of the rate combine to give an overall rate and how the identification of those individual rate contributors provide mechanistic insight into complex heterogeneous reactions. This generates a paradigm change by proposing a new pathway to reaction model parameterization and for the prediction of reaction rates.

Driving factors of interactions between the exchange rate market and the commodity market: A wavelet-based complex network perspective

NASA Astrophysics Data System (ADS)

Wen, Shaobo; An, Haizhong; Chen, Zhihua; Liu, Xueyong

2017-08-01

In traditional econometrics, a time series must be in a stationary sequence. However, it usually shows time-varying fluctuations, and it remains a challenge to execute a multiscale analysis of the data and discover the topological characteristics of conduction in different scales. Wavelet analysis and complex networks in physical statistics have special advantages in solving these problems. We select the exchange rate variable from the Chinese market and the commodity price index variable from the world market as the time series of our study. We explore the driving factors behind the behavior of the two markets and their topological characteristics in three steps. First, we use the Kalman filter to find the optimal estimation of the relationship between the two markets. Second, wavelet analysis is used to extract the scales of the relationship that are driven by different frequency wavelets. Meanwhile, we search for the actual economic variables corresponding to different frequency wavelets. Finally, a complex network is used to search for the transfer characteristics of the combination of states driven by different frequency wavelets. The results show that statistical physics have a unique advantage over traditional econometrics. The Chinese market has time-varying impacts on the world market: it has greater influence when the world economy is stable and less influence in times of turmoil. The process of forming the state combination is random. Transitions between state combinations have a clustering feature. Based on these characteristics, we can effectively reduce the information burden on investors and correctly respond to the government's policy mix.

Crew Launch Vehicle Mobile Launcher Solid Rocket Motor Plume Induced Environment

NASA Technical Reports Server (NTRS)

Vu, Bruce T.; Sulyma, Peter

2008-01-01

The plume-induced environment created by the Ares 1 first stage, five-segment reusable solid rocket motor (RSRMV) will impose high heating rates and impact pressures on Launch Complex 39. The extremes of these environments pose a potential threat to weaken or even cause structural components to fail if insufficiently designed. Therefore the ability to accurately predict these environments is critical to assist in specifying structural design requirements to insure overall structural integrity and flight safety. This paper presents the predicted thermal and pressure environments induced by the launch of the Crew Launch Vehicle (CLV) from Launch Complex (LC) 39. Once the environments are predicted, a follow-on thermal analysis is required to determine the surface temperature response and the degradation rate of the materials. An example of structures responding to the plume-induced environment will be provided.

A volumetric ablation model of EPDM considering complex physicochemical process in porous structure of char layer

NASA Astrophysics Data System (ADS)

Yang, Liu; Xiao-Jing, Yu; Jian-Ming, Ma; Yi-Wen, Guan; Jiang, Li; Qiang, Li; Sa, Yang

2017-06-01

A volumetric ablation model for EPDM (ethylene- propylene-diene monomer) is established in this paper. This model considers the complex physicochemical process in the porous structure of a char layer. An ablation physics model based on a porous structure of a char layer and another model of heterogeneous volumetric ablation char layer physics are then built. In the model, porosity is used to describe the porous structure of a char layer. Gas diffusion and chemical reactions are introduced to the entire porous structure. Through detailed formation analysis, the causes of the compact or loose structure in the char layer and chemical vapor deposition (CVD) reaction between pyrolysis gas and char layer skeleton are introduced. The Arrhenius formula is adopted to determine the methods for calculating carbon deposition rate C which is the consumption rate caused by thermochemical reactions in the char layer, and porosity evolution. The critical porosity value is used as a criterion for char layer porous structure failure under gas flow and particle erosion. This critical porosity value is obtained by fitting experimental parameters and surface porosity of the char layer. Linear ablation and mass ablation rates are confirmed with the critical porosity value. Results of linear ablation and mass ablation rate calculations generally coincide with experimental results, suggesting that the ablation analysis proposed in this paper can accurately reflect practical situations and that the physics and mathematics models built are accurate and reasonable.

A Force-Activated Trip Switch Triggers Rapid Dissociation of a Colicin from Its Immunity Protein

PubMed Central

Farrance, Oliver E.; Hann, Eleanore; Kaminska, Renata; Housden, Nicholas G.; Derrington, Sasha R.; Kleanthous, Colin; Radford, Sheena E.; Brockwell, David J.

2013-01-01

Colicins are protein antibiotics synthesised by Escherichia coli strains to target and kill related bacteria. To prevent host suicide, colicins are inactivated by binding to immunity proteins. Despite their high avidity (Kd≈fM, lifetime ≈4 days), immunity protein release is a pre-requisite of colicin intoxication, which occurs on a timescale of minutes. Here, by measuring the dynamic force spectrum of the dissociation of the DNase domain of colicin E9 (E9) and immunity protein 9 (Im9) complex using an atomic force microscope we show that application of low forces (<20 pN) increases the rate of complex dissociation 106-fold, to a timescale (lifetime ≈10 ms) compatible with intoxication. We term this catastrophic force-triggered increase in off-rate a trip bond. Using mutational analysis, we elucidate the mechanism of this switch in affinity. We show that the N-terminal region of E9, which has sparse contacts with the hydrophobic core, is linked to an allosteric activator region in E9 (residues 21–30) whose remodelling triggers immunity protein release. Diversion of the force transduction pathway by the introduction of appropriately positioned disulfide bridges yields a force resistant complex with a lifetime identical to that measured by ensemble techniques. A trip switch within E9 is ideal for its function as it allows bipartite complex affinity, whereby the stable colicin:immunity protein complex required for host protection can be readily converted to a kinetically unstable complex whose dissociation is necessary for cellular invasion and competitor death. More generally, the observation of two force phenotypes for the E9:Im9 complex demonstrates that force can re-sculpt the underlying energy landscape, providing new opportunities to modulate biological reactions in vivo; this rationalises the commonly observed discrepancy between off-rates measured by dynamic force spectroscopy and ensemble methods. PMID:23431269

Immunostimulatory oligonucleotide-induced metaphase cytogenetics detect chromosomal aberrations in 80% of CLL patients: A study of 132 CLL cases with correlation to FISH, IgVH status, and CD38 expression.

PubMed

Dicker, Frank; Schnittger, Susanne; Haferlach, Torsten; Kern, Wolfgang; Schoch, Claudia

2006-11-01

Compared with fluorescence in situ hybridization (FISH), conventional metaphase cytogenetics play only a minor prognostic role in chronic lymphocytic leukemia (CLL) so far, due to technical problems resulting from limited proliferation of CLL cells in vitro. Here, we present a simple method for in vitro stimulation of CLL cells that overcomes this limitation. In our unselected patient population, 125 of 132 cases could be successfully stimulated for metaphase generation by culture with the immunostimulatory CpG-oligonucleotide DSP30 plus interleukin 2. Of 125 cases, 101 showed chromosomal aberrations. The aberration rate is comparable to the rate detected by parallel interphase FISH. In 47 patients, conventional cytogenetics detected additional aberrations not detected by FISH analysis. A complex aberrant karyotype, defined as one having at least 3 aberrations, was detected in 30 of 125 patients, compared with only one such case as defined by FISH. Conventional cytogenetics frequently detected balanced and unbalanced translocations. A significant correlation of the poor-prognosis unmutated IgV(H) status with unbalanced translocations and of the likewise poor-prognosis CD38 expression to balanced translocations and complex aberrant karyotype was found. We demonstrate that FISH analysis underestimates the complexity of chromosomal aberrations in CLL. Therefore, conventional cytogenetics may define subgroups of patients with high risk of progression.

The luminescence properties of the heteroleptic [Re(CO)3(N∩N)Cl] and [Re(CO)3(N∩N)(CH3CN)](+) complexes in view of the combined Marcus-Jortner and Mulliken-Hush formalism.

PubMed

Woźna, Agnieszka; Kapturkiewicz, Andrzej

2015-11-11

The luminescence properties of the heteroleptic fac-Re(CO)3(+) complexes with α-diimine N∩N ligands, neutral [Re(CO)3(N∩N)Cl] and cationic [Re(CO)3(N∩N)(CH3CN)](+) species, have been studied in acetonitrile solutions at room temperature. The investigated complexes exhibit the metal to ligand charge-transfer (MLCT) phosphorescence with the emission characteristics strongly affected by the nature of coordinated α-diimine N∩N ligands. The observed trends can be quantitatively described by invoking the electronic interactions between (3)*LC and (3)*MLCT states as well as the spin-orbit interactions between (3)*MLCT and (1)*MLCT states, respectively. All quantities necessary for the description can be straightforwardly accounted from analysis of the radiative (1)*MLCT ← S0 and (3)*MLCT → S0 charge transfer processes. It is also demonstrated that the radiative kr and non-radiative knr decay rate constants of the excited (3)*MLCT states can be interpreted within the same set of parameters. As expected from the Mulliken-Hush formalism the both processes are strictly related that allows prediction of the non-radiative knr rate constants using the parameters available from analysis of the radiative (1)*MLCT ← S0 and (3)*MLCT → S0 charge transfer processes.

Classification of time-of-flight secondary ion mass spectrometry spectra from complex Cu-Fe sulphides by principal component analysis and artificial neural networks.

PubMed

Kalegowda, Yogesh; Harmer, Sarah L

2013-01-08

Artificial neural network (ANN) and a hybrid principal component analysis-artificial neural network (PCA-ANN) classifiers have been successfully implemented for classification of static time-of-flight secondary ion mass spectrometry (ToF-SIMS) mass spectra collected from complex Cu-Fe sulphides (chalcopyrite, bornite, chalcocite and pyrite) at different flotation conditions. ANNs are very good pattern classifiers because of: their ability to learn and generalise patterns that are not linearly separable; their fault and noise tolerance capability; and high parallelism. In the first approach, fragments from the whole ToF-SIMS spectrum were used as input to the ANN, the model yielded high overall correct classification rates of 100% for feed samples, 88% for conditioned feed samples and 91% for Eh modified samples. In the second approach, the hybrid pattern classifier PCA-ANN was integrated. PCA is a very effective multivariate data analysis tool applied to enhance species features and reduce data dimensionality. Principal component (PC) scores which accounted for 95% of the raw spectral data variance, were used as input to the ANN, the model yielded high overall correct classification rates of 88% for conditioned feed samples and 95% for Eh modified samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Promoting Recruitment using Information Management Efficiently (PRIME): a stepped-wedge, cluster randomised trial of a complex recruitment intervention embedded within the REstart or Stop Antithrombotics Randomised Trial.

PubMed

Maxwell, Amy E; Parker, Richard A; Drever, Jonathan; Rudd, Anthony; Dennis, Martin S; Weir, Christopher J; Al-Shahi Salman, Rustam

2017-12-28

Few interventions are proven to increase recruitment in clinical trials. Recruitment to RESTART, a randomised controlled trial of secondary prevention after stroke due to intracerebral haemorrhage, has been slower than expected. Therefore, we sought to investigate an intervention to boost recruitment to RESTART. We conducted a stepped-wedge, cluster randomised trial of a complex intervention to increase recruitment, embedded within the RESTART trial. The primary objective was to investigate if the PRIME complex intervention (a recruitment co-ordinator who conducts a recruitment review, provides access to bespoke stroke audit data exports, and conducts a follow-up review after 6 months) increases the recruitment rate to RESTART. We included 72 hospital sites located in England, Wales, or Scotland that were active in RESTART in June 2015. All sites began in the control state and were allocated using block randomisation stratified by hospital location (Scotland versus England/Wales) to start the complex intervention in one of 12 different months. The primary outcome was the number of patients randomised into RESTART per month per site. We quantified the effect of the complex intervention on the primary outcome using a negative binomial, mixed model adjusting for site, December/January months, site location, and background time trends in recruitment rate. We recruited and randomised 72 sites and recorded their monthly recruitment to RESTART over 24 months (March 2015 to February 2017 inclusive), providing 1728 site-months of observations for the primary analysis. The adjusted rate ratio for the number of patients randomised per month after allocation to the PRIME complex intervention versus control time before allocation to the PRIME complex intervention was 1.06 (95% confidence interval 0.55 to 2.03, p = 0.87). Although two thirds of respondents to the 6-month follow-up questionnaire agreed that the audit reports were useful, only six patients were reported to have been randomised using the audit reports. Respondents frequently reported resource and time pressures as being key barriers to running the audit reports. The PRIME complex intervention did not significantly improve the recruitment rate to RESTART. Further research is needed to establish if PRIME might be beneficial at an earlier stage in a prevention trial or for prevention dilemmas that arise more often in clinical practice.

Scale-Dependent Rates of Uranyl Surface Complexation Reaction in Sediments

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

Liu, Chongxuan; Shang, Jianying; Kerisit, Sebastien N.

Scale-dependency of uranyl[U(VI)] surface complexation rates was investigated in stirred flow-cell and column systems using a U(VI)-contaminated sediment from the US Department of Energy, Hanford site, WA. The experimental results were used to estimate the apparent rate of U(VI) surface complexation at the grain-scale and in porous media. Numerical simulations using molecular, pore-scale, and continuum models were performed to provide insights into and to estimate the rate constants of U(VI) surface complexation at the different scales. The results showed that the grain-scale rate constant of U(VI) surface complexation was over 3 to 10 orders of magnitude smaller, dependent on themore » temporal scale, than the rate constant calculated using the molecular simulations. The grain-scale rate was faster initially and slower with time, showing the temporal scale-dependency. The largest rate constant at the grain-scale decreased additional 2 orders of magnitude when the rate was scaled to the porous media in the column. The scaling effect from the grain-scale to the porous media became less important for the slower sorption sites. Pore-scale simulations revealed the importance of coupled mass transport and reactions in both intragranular and inter-granular domains, which caused both spatial and temporal dependence of U(VI) surface complexation rates in the sediment. Pore-scale simulations also revealed a new rate-limiting mechanism in the intragranular porous domains that the rate of coupled diffusion and surface complexation reaction was slower than either process alone. The results provided important implications for developing models to scale geochemical/biogeochemical reactions.« less

A bimetallic aluminum(salen) complex for the synthesis of 1,3-oxathiolane-2-thiones and 1,3-dithiolane-2-thiones.

PubMed

Clegg, William; Harrington, Ross W; North, Michael; Villuendas, Pedro

2010-09-17

The combined use of the bimetallic aluminum(salen) complex [Al(salen)](2)O and tetrabutylammonium bromide (or tributylamine) is found to catalyze the reaction between epoxides and carbon disulfide. In most cases, at 50 °C, the reaction produces 1,3-oxathiolane-2-thiones, while at 90 °C, 1,3-dithiolane-2-thiones are the main product. The structure and stereochemistry of three of the 1,3-dithiolane-2-thiones is unambiguously determined by X-ray crystallographic analysis, and this is used to correct errors in the literature concerning the synthesis of cyclic di- and trithiocarbonates. The kinetics of 1,3-oxathiolane-2-thione synthesis are determined, and the resulting rate equation, along with a stereochemical analysis of the reaction and catalyst modification studies, is used to determine a mechanism for the synthesis of 1,3-oxathiolane-2-thiones which contrasts with the mechanism previously determined for cyclic carbonate synthesis using the same bimetallic aluminum(salen) complex.

A comparative analysis of alternative approaches for quantifying nonlinear dynamics in cardiovascular system.

PubMed

Chen, Yun; Yang, Hui

2013-01-01

Heart rate variability (HRV) analysis has emerged as an important research topic to evaluate autonomic cardiac function. However, traditional time and frequency-domain analysis characterizes and quantify only linear and stationary phenomena. In the present investigation, we made a comparative analysis of three alternative approaches (i.e., wavelet multifractal analysis, Lyapunov exponents and multiscale entropy analysis) for quantifying nonlinear dynamics in heart rate time series. Note that these extracted nonlinear features provide information about nonlinear scaling behaviors and the complexity of cardiac systems. To evaluate the performance, we used 24-hour HRV recordings from 54 healthy subjects and 29 heart failure patients, available in PhysioNet. Three nonlinear methods are evaluated not only individually but also in combination using three classification algorithms, i.e., linear discriminate analysis, quadratic discriminate analysis and k-nearest neighbors. Experimental results show that three nonlinear methods capture nonlinear dynamics from different perspectives and the combined feature set achieves the best performance, i.e., sensitivity 97.7% and specificity 91.5%. Collectively, nonlinear HRV features are shown to have the promise to identify the disorders in autonomic cardiovascular function.

State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students

PubMed Central

Dimitriev, Aleksey D.

2016-01-01

Objectives Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. Methods A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of SA. Results Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. Conclusions The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation. PMID:26807793

[The impact of harmful occupational factors on the morbidity rate of workers of the railway-car repair plant].

PubMed

Sudeikina, N A; Kurenkova, G V; Lemeshevskaya, E P

The rail transport is the one of the leading sectors of the national economy. More than 50% of the employees of the enterprises of the railway complex work under the unfavourable impact of hazardous and dangerous substances and occupational factors. In the literature issues of working conditions and health of employees of railway carrepairing plant are hardly highlighted. The aim of the study is the evaluation of the morbidity rate shaped under the influence of harmful occupational factors for the elaboration of preventive measures. In the work there were used generally accepted methods of hygienic studies, analysis of morbidity rate with temporary disability (TD), according to records of periodic medical examinations, occupational prevalence. The railway car-repairing plant was established to be characterized by the complex of harmful factors of the working environment and labor process: noise, local vibration, industrial aerosols of complex composition, chemicals, low light, hardness of the labor process. The levels of incidence with temporal disability in the studied groups, depending on the work seniority in the harmful labor conditions, significantly decrease with the experience from 5 to 9 years and increase with the experience more than 10 years. Executed in-depth analysis as of the both morbidity rate and TD, as well results of periodic medical examinations of workers of main shops shows that overall indices of the morbidity rate and TD are significantly higher than in the comparison group; levels of the morbidity rate and TD in the observed groups significantly decline depending on the length of service in hazardous working conditions with a length of the experience offrom 5 to 9 years and increase with the increase in the length of experience of 10 years or more. In the structure of morbidity and TD leading positions are occupied by diseases of the respiratory system, musculoskeletal system and connective tissue, circulatory system and digestive system, diseases of the eye and its appendages. The health damage risk coefficients in the studied groups of workers and the average losses of working time due to the morbidity with TD per 1 employee in all shops are higher than those in the comparison group. The level of the occupational morbidity rate is very low. Harmful working conditions contribute to the development of general and occupationally related diseases.

A Novel Method for Assessing Task Complexity in Outpatient Clinical-Performance Measures.

PubMed

Hysong, Sylvia J; Amspoker, Amber B; Petersen, Laura A

2016-04-01

Clinical-performance measurement has helped improve the quality of health-care; yet success in attaining high levels of quality across multiple domains simultaneously still varies considerably. Although many sources of variability in care quality have been studied, the difficulty required to complete the clinical work itself has received little attention. We present a task-based methodology for evaluating the difficulty of clinical-performance measures (CPMs) by assessing the complexity of their component requisite tasks. Using Functional Job Analysis (FJA), subject-matter experts (SMEs) generated task lists for 17 CPMs; task lists were rated on ten dimensions of complexity, and then aggregated into difficulty composites. Eleven outpatient work SMEs; 133 VA Medical Centers nationwide. Clinical Performance: 17 outpatient CPMs (2000-2008) at 133 VA Medical Centers nationwide. Measure Difficulty: for each CPM, the number of component requisite tasks and the average rating across ten FJA complexity scales for the set of tasks comprising the measure. Measures varied considerably in the number of component tasks (M = 10.56, SD = 6.25, min = 5, max = 25). Measures of chronic care following acute myocardial infarction exhibited significantly higher measure difficulty ratings compared to diabetes or screening measures, but not to immunization measures ([Formula: see text] = 0.45, -0.04, -0.05, and -0.06 respectively; F (3, 186) = 3.57, p = 0.015). Measure difficulty ratings were not significantly correlated with the number of component tasks (r = -0.30, p = 0.23). Evaluating the difficulty of achieving recommended CPM performance levels requires more than simply counting the tasks involved; using FJA to assess the complexity of CPMs' component tasks presents an alternate means of assessing the difficulty of primary-care CPMs and accounting for performance variation among measures and performers. This in turn could be used in designing performance reward programs, or to match workflow to clinician time and effort.

Soil Organic Carbon Sequestration by Tillage and Crop Rotation: A Global Data Analysis

DOE Data Explorer

West, Tristram O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Post, Wilfred M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2002-01-01

Changes in agricultural management can potentially increase the accumulation rate of soil organic carbon (SOC), thereby sequestering CO2 from the atmosphere. This study was conducted to quantify potential soil carbon (C) sequestration rates for different crops in response to decreasing tillage intensity or enhancing rotation complexity, and to estimate the duration of time over which sequestration may occur. Analyses of C sequestration rates were completed using a global database of 67 long-term agricultural experiments, consisting of 276 paired treatments. Results indicate, on average, that a change from conventional tillage (CT) to no-till (NT) can sequester 57 ± 14 g C m^–2 yr^–1, excluding wheat (Triticum aestivum L.)-fallow systems which may not result in SOC accumulation with a change from CT to NT. Enhancing rotation complexity can sequester an average 14 ± 11 g C m^–2 yr^–1, excluding a change from continuous corn (Zea mays L.) to corn-soybean (Glycine max L.) which may not result in a significant accumulation of SOC. Carbon sequestration rates, with a change from CT to NT, can be expected to peak in 5-10 yr with SOC reaching a new equilibrium in 15-20 yr. Following initiation of an enhancement in rotation complexity, SOC may reach a new equilibrium in approximately 40-60 yr. Carbon sequestration rates, estimated for a number of individual crops and crop rotations in this study, can be used in spatial modeling analyses to more accurately predict regional, national, and global C sequestration potentials.

A complex breastfeeding promotion and support intervention in a developing country: study protocol for a randomized clinical trial

PubMed Central

2014-01-01

Background Breastfeeding has countless benefits to mothers, children and community at large, especially in developing countries. Studies from Lebanon report disappointingly low breastfeeding exclusivity and continuation rates. Evidence reveals that antenatal breastfeeding education, professional lactation support, and peer lay support are individually effective at increasing breastfeeding duration and exclusivity, particularly in low-income settings. Given the complex nature of the breastfeeding ecosystem and its barriers in Lebanon, we hypothesize that a complex breastfeeding support intervention, which is centered on the three components mentioned above, would significantly increase breastfeeding rates. Methods/Design A multi-center randomized controlled trial. Study population: 443 healthy pregnant women in their first trimester will be randomized to control or intervention group. Intervention: A “prenatal/postnatal” professional and peer breastfeeding support package continuing till 6 months postpartum, guided by the Social Network and Social Support Theory. Control group will receive standard prenatal and postnatal care. Mothers will be followed up from early pregnancy till five years after delivery. Outcome measures: Total and exclusive breastfeeding rates, quality of life at 1, 3 and 6 months postpartum, maternal breastfeeding knowledge and attitudes at 6 months postpartum, maternal exclusive breastfeeding rates of future infants up to five years from baseline, cost-benefit and cost-effectiveness analyses of the intervention. Statistical analysis: Descriptive and regression analysis will be conducted under the intention to treat basis using the most recent version of SPSS. Discussion Exclusive breastfeeding is a cost-effective public health measure that has a significant impact on infant morbidity and mortality. In a country with limited healthcare resources like Lebanon, developing an effective breastfeeding promotion and support intervention that is easily replicated across various settings becomes a priority. If positive, the results of this study would provide a generalizable model to bolster breastfeeding promotion efforts and contribute to improved child health in Lebanon and the Middle East and North Africa (MENA) region. Trial registration Current Controlled Trials ISRCTN17875591 PMID:24428951

Complexity of the heart rhythm after heart transplantation by entropy of transition network for RR-increments of RR time intervals between heartbeats.

PubMed

Makowiec, Danuta; Struzik, Zbigniew; Graff, Beata; Wdowczyk-Szulc, Joanna; Zarczynska-Buchnowiecka, Marta; Gruchala, Marcin; Rynkiewicz, Andrzej

2013-01-01

Network models have been used to capture, represent and analyse characteristics of living organisms and general properties of complex systems. The use of network representations in the characterization of time series complexity is a relatively new but quickly developing branch of time series analysis. In particular, beat-to-beat heart rate variability can be mapped out in a network of RR-increments, which is a directed and weighted graph with vertices representing RR-increments and the edges of which correspond to subsequent increments. We evaluate entropy measures selected from these network representations in records of healthy subjects and heart transplant patients, and provide an interpretation of the results.

Bioelectrical Markers of ADHD: Enhancement of Direct EEG Analysis

ERIC Educational Resources Information Center

Martín-Brufau, Ramón; Nombela Gómez, Manuel

2017-01-01

Introduction: So far some methods to help diagnosis of ADHD grounded in EEG decomposition by the FFT method and the discovery of the relationship between different frequency bands, the most clarifying the TBR rate in the prefrontal regions, have been proposed. This procedure requires a complex gadgetry so we evaluate the advantages of a simple…

Relationship between Effective Application of Machine Learning and Malware Detection: A Quantitative Study

ERIC Educational Resources Information Center

Enfinger, Kerry Wayne

2016-01-01

The number of malicious files present in the public domain continues to rise at a substantial rate. Current anti-malware software utilizes a signature-based method to detect the presence of malicious software. Generating these pattern signatures is time consuming due to malicious code complexity and the need for expert analysis, however, by making…

Genomic study and Medical Subject Headings enrichment analysis of early pregnancy rate and antral follicle numbers in Nelore heifers

USDA-ARS?s Scientific Manuscript database

Zebu animals (Bos indicus) are known to take longer to reach puberty when compared to taurine animals (Bos taurus), limiting the supply of animals for harvest or breeding and impacting profitability. Genomic information can be a helpful tool to better understand complex traits, and improve genetic g...

"Vergara" and the Complexities of Teacher Employment Policies. ECS Education Policy Analysis

ERIC Educational Resources Information Center

Rowland, Julie

2015-01-01

Teaching quality is a crucial factor in student success, contributing to students' short- and long-term learning opportunities. High-quality teaching not only contributes to the improvement of student test scores and graduation rates but also gives students a "strong foundation from which to advance and achieve" in the future. Long term,…

The Roles of Internal Representation and Processing in Problem Solving Involving Insight: A Computational Complexity Perspective

ERIC Educational Resources Information Center

Wareham, Todd

2017-01-01

In human problem solving, there is a wide variation between individuals in problem solution time and success rate, regardless of whether or not this problem solving involves insight. In this paper, we apply computational and parameterized analysis to a plausible formalization of extended representation change theory (eRCT), an integration of…

Advances in electronic-nose technologies developed for biomedical applications

Treesearch

Dan Wilson; Manuela Baietto

2011-01-01

The research and development of new electronic-nose applications in the biomedical field has accelerated at a phenomenal rate over the past 25 years. Many innovative e-nose technologies have provided solutions and applications to a wide variety of complex biomedical and healthcare problems. The purposes of this review are to present a comprehensive analysis of past and...

An investigation of multi-rate sound decay under strongly non-diffuse conditions: The crypt of the Cathedral of Cadiz

NASA Astrophysics Data System (ADS)

Martellotta, Francesco; Álvarez-Morales, Lidia; Girón, Sara; Zamarreño, Teófilo

2018-05-01

Multi-rate sound decays are often found and studied in complex systems of coupled volumes where diffuse field conditions generally apply, although the openings connecting different sub-spaces are by themselves potential causes of non-diffuse behaviour. However, in presence of spaces in which curved surfaces clearly prevent diffuse field behaviour from being established, things become more complex and require more sophisticated tools (or, better, combinations of them) to be fully understood. As an example of such complexity, the crypt of the Cathedral of Cadiz is a relatively small space characterised by a central vaulted rotunda, with five radial galleries with flat and low ceiling. In addition, the crypt is connected to the main cathedral volume by means of several small openings. Acoustic measurements carried out in the crypt pointed out the existence of at least two decay processes combined, in some points, with flutter echoes. Application of conventional methods of analysis pointed out the existence of significant differences between early decay time and reverberation time, but was inconclusive in explaining the origin of the observed phenomena. The use of more robust Bayesian analysis permitted the conclusion that the late decay appearing in the crypt had a different rate than that observed in the cathedral, thus excluding the explanation based on acoustic coupling of different volumes. Finally, processing impulse responses collected by means of a B-format microphone to obtain directional intensity maps demonstrated that the late decay was originated from the rotunda where a repetitive reflection pattern appeared between the floor and the dome causing both flutter echoes and a longer reverberation time.

Advances in heart rate variability signal analysis: joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society.

PubMed

Sassi, Roberto; Cerutti, Sergio; Lombardi, Federico; Malik, Marek; Huikuri, Heikki V; Peng, Chung-Kang; Schmidt, Georg; Yamamoto, Yoshiharu

2015-09-01

Following the publication of the Task Force document on heart rate variability (HRV) in 1996, a number of articles have been published to describe new HRV methodologies and their application in different physiological and clinical studies. This document presents a critical review of the new methods. A particular attention has been paid to methodologies that have not been reported in the 1996 standardization document but have been more recently tested in sufficiently sized populations. The following methods were considered: Long-range correlation and fractal analysis; Short-term complexity; Entropy and regularity; and Nonlinear dynamical systems and chaotic behaviour. For each of these methods, technical aspects, clinical achievements, and suggestions for clinical application were reviewed. While the novel approaches have contributed in the technical understanding of the signal character of HRV, their success in developing new clinical tools, such as those for the identification of high-risk patients, has been rather limited. Available results obtained in selected populations of patients by specialized laboratories are nevertheless of interest but new prospective studies are needed. The investigation of new parameters, descriptive of the complex regulation mechanisms of heart rate, has to be encouraged because not all information in the HRV signal is captured by traditional methods. The new technologies thus could provide after proper validation, additional physiological, and clinical meaning. Multidisciplinary dialogue and specialized courses in the combination of clinical cardiology and complex signal processing methods seem warranted for further advances in studies of cardiac oscillations and in the understanding normal and abnormal cardiac control processes. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Effect of ultrasonic waves on the water turbidity during the oxidation of phenol. Formation of (hydro)peroxo complexes.

PubMed

Villota, Natalia; Lomas, Jose M; Camarero, Luis M

2017-11-01

Analysis of the kinetics of aqueous phenol oxidation by a sono-Fenton process reveals that the via involving ortho-substituted intermediates prevails: catechol (25.0%), hydroquinone (7.7%) and resorcinol (0.6%). During the oxidation, water rapidly acquires color that reaches its maximum intensity at the maximum concentration of p-benzoquinone. Turbidity formation occurs at a slower rate. Oxidant dosage determines the nature of the intermediates, being trihydroxylated benzenes (pyrogallol, hydroxyhydroquinone) and muconic acid the main precursors causing turbidity. It is found that the concentration of iron species and ultrasonic waves affects the intensity of the turbidity. The pathway of (hydro)peroxo-iron(II) complexes formation is proposed. Operating with 20.0-27.8mgFe 2+ /kW rates leads to formation of (hydro)peroxo-iron(II) complexes, which induce high turbidity levels. These species would dissociate into ZZ-muconic acid and ferrous ions. Applying relationships around 13.9mgFe 2+ /kW, the formation of (hydro)peroxo-iron(III) complexes would occur, which could react with carboxylic acids (2,5-dioxo-3-hexenedioic acid). That reaction induces turbidity slower. This is due to the organic substrate reacting with two molecules of the (hydro)peroxo complex. Therefore, it is necessary to accelerate the iron regeneration, intensifying the ultrasonic irradiation. Afterwards, this complex would dissociate into maleic acid and ferric ions. Copyright © 2017 Elsevier B.V. All rights reserved.

Rotation and strain rate of Sulawesi from geometrical velocity field

NASA Astrophysics Data System (ADS)

Sarsito, D. A.; Susilo, Simons, W. J. F.; Abidin, H. Z.; Sapiie, B.; Triyoso, W.; Andreas, H.

2017-07-01

One of methods that can be used to determine the tectonic deformation status is rate estimation from geometric rotation and strain using quantitative velocity data from GPS observations. Microplate Sulawesi region located in the zone of triple junction (Eurasia, Australia and Philippine Sea Plates) has very complex tectonic and seismic condition, which is why become very important to know its recent deformation status in order to study neo-tectonic and disaster mitigation. Deformation rate quantification is estimated in two parameters: rotation and geodetic strain rate of each GPS station Delaunay triangle in the study area. The analysis in this study is not done using the grids since there is no rheological information at location that can be used as the interpolation-extrapolation constraints. Our analysis reveals that Sulawesi is characterized by rapid rotation in several different domains and compression-strain pattern that varies depending on the type and boundary conditions of microplate. This information is useful for studying neo tectonic deformation status and earthquake disaster mitigation.

Dissolution of Fe(III) (hydr) oxides by metal-EDTA complexes

NASA Astrophysics Data System (ADS)

Ngwack, Bernd; Sigg, Laura

1997-03-01

The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA CaEDTA ≫ PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced.

Surface functions during mitosis. III. Quantitative analysis of ligand- receptor movement into the cleavage furrow: diffusion vs. flow

PubMed Central

1982-01-01

The surface distribution of concanavalin A (Con A) bound to cell membrane receptors varies dramatically as a function of mitotic phase. The lectin is distributed diffusely on cells labeled and observed between mid-prophase and early anaphase, whereas cells observed in late anaphase or telophase demonstrate a marked accumulation of Con A- receptor complexes over the developing cleavage furrow (Berlin, Oliver, and Walter. 1978. Cell. 15:327-341). In this report, we first use a system based on video intensification fluorescence microscopy to describe the simultaneous changes in cell shape and in lectin-receptor complex topography during progression of single cells through the mitotic cycle. The video analysis establishes that fluorescein succinyl Con A (F-S Con A)-receptor complex redistribution begins coincident with the first appearance of the cleavage furrow and is essentially complete within 2-3 min. This remarkable redistribution of surface fluorescence occurs during only a modest change in cell shape from a sphere to a belted cylinder. It reflects the translocation of complexes and not the accumulation of excess labeled membrane in the cleavage furrow: first, bound fluorescent cholera toxin which faithfully outlines the plasma membrane is not accumulated in the cleavage furrow, and, second, electron microscopy of peroxidase-Con A labeled cells undergoing cleavage shows that there is a high linear density of lectin within the furrow while Con A is virtually eliminated from the poles. The rate of surface movement of F-S Con A was quantitated by photon counting during a repetitive series of laser-excited fluorescence scans across dividing cells. Results were analyzed in terms of two alternative models of movement: a flow model in which complexes moved unidirectionally at constant velocity, and a diffusion model in which complexes could diffuse freely but were trapped at the cleavage furrow. According to these models, the observed rates of accumulation were attainable at either an effective flow velocity of approximately 1 micron/min, or an effective diffusion coefficient of approximately 10(- 9) cm2/s. However, in separate experiments the lectin-receptor diffusion rate measured directly by the method of fluorescence recovery after photobleaching (FRAP) on metaphase cells was only approximately 10(-10) cm2/s. Most importantly, photobleaching experiments during the actual period of F-S Con A accumulation showed that lectin-receptor movement during cleavage occurs unidirectionally. These results rule out diffusion and make a process of oriented flow of ligand-receptor complexes the most likely mechanism for ligand-receptor accumulation in the cleavage furrow. PMID:7119007

Arrhenius analysis of the electrophorus electricus acetylcholinesterase-catalyzed hydrolysis of acetylthiocholine.

PubMed

Oakes, Jesse; Nguyen, Tina; Britt, B Mark

2003-06-01

Ellman's method was used to determine the Michaelis-Menten parameters for the hydrolysis of acetylthiocholine by Electrophorus electricus acetylcholinesterase from 12 to 37 degrees C. Arrhenius analysis revealed that the activation energy for formation of the enzyme/substrate complex is 22.2 +/- 1.1 kJ/mole. The Arrhenius plot of k(cat) is markedly curved and attributed to comparable rates of acylation and deacylation due to the absence of evidence for a temperature-dependent enzyme conformational change by differential scanning calorimetry.

Mitochondrial Respiration in Human Colorectal and Breast Cancer Clinical Material Is Regulated Differently

PubMed Central

Koit, Andre; Ounpuu, Lyudmila; Klepinin, Aleksandr; Chekulayev, Vladimir; Timohhina, Natalja; Tepp, Kersti; Puurand, Marju; Truu, Laura; Heck, Karoliina; Valvere, Vahur; Guzun, Rita

2017-01-01

We conducted quantitative cellular respiration analysis on samples taken from human breast cancer (HBC) and human colorectal cancer (HCC) patients. Respiratory capacity is not lost as a result of tumor formation and even though, functionally, complex I in HCC was found to be suppressed, it was not evident on the protein level. Additionally, metabolic control analysis was used to quantify the role of components of mitochondrial interactosome. The main rate-controlling steps in HBC are complex IV and adenine nucleotide transporter, but in HCC, complexes I and III. Our kinetic measurements confirmed previous studies that respiratory chain complexes I and III in HBC and HCC can be assembled into supercomplexes with a possible partial addition from the complex IV pool. Therefore, the kinetic method can be a useful addition in studying supercomplexes in cell lines or human samples. In addition, when results from culture cells were compared to those from clinical samples, clear differences were present, but we also detected two different types of mitochondria within clinical HBC samples, possibly linked to two-compartment metabolism. Taken together, our data show that mitochondrial respiration and regulation of mitochondrial membrane permeability have substantial differences between these two cancer types when compared to each other to their adjacent healthy tissue or to respective cell cultures. PMID:28781720

Phenotyping the quality of complex medium components by simple online-monitored shake flask experiments.

PubMed

Diederichs, Sylvia; Korona, Anna; Staaden, Antje; Kroutil, Wolfgang; Honda, Kohsuke; Ohtake, Hisao; Büchs, Jochen

2014-11-07

Media containing yeast extracts and other complex raw materials are widely used for the cultivation of microorganisms. However, variations in the specific nutrient composition can occur, due to differences in the complex raw material ingredients and in the production of these components. These lot-to-lot variations can affect growth rate, product yield and product quality in laboratory investigations and biopharmaceutical production processes. In the FDA's Process Analytical Technology (PAT) initiative, the control and assessment of the quality of critical raw materials is one key aspect to maintain product quality and consistency. In this study, the Respiration Activity Monitoring System (RAMOS) was used to evaluate the impact of different yeast extracts and commercial complex auto-induction medium lots on metabolic activity and product yield of four recombinant Escherichia coli variants encoding different enzymes. Under non-induced conditions, the oxygen transfer rate (OTR) of E. coli was not affected by a variation of the supplemented yeast extract lot. The comparison of E. coli cultivations under induced conditions exhibited tremendous differences in OTR profiles and volumetric activity for all investigated yeast extract lots of different suppliers as well as lots of the same supplier independent of the E. coli variant. Cultivation in the commercial auto-induction medium lots revealed the same reproducible variations. In cultivations with parallel offline analysis, the highest volumetric activity was found at different cultivation times. Only by online monitoring of the cultures, a distinct cultivation phase (e.g. glycerol depletion) could be detected and chosen for comparable and reproducible offline analysis of the yield of functional product. This work proves that cultivations conducted in complex media may be prone to significant variation in final product quality and quantity if the quality of the raw material for medium preparation is not thoroughly checked. In this study, the RAMOS technique enabled a reliable and reproducible screening and phenotyping of complex raw material lots by online measurement of the respiration activity. Consequently, complex raw material lots can efficiently be assessed if the distinct effects on culture behavior and final product quality and quantity are visualized.

Cardiac interbeat interval dynamics from childhood to senescence : comparison of conventional and new measures based on fractals and chaos theory

NASA Technical Reports Server (NTRS)

Pikkujamsa, S. M.; Makikallio, T. H.; Sourander, L. B.; Raiha, I. J.; Puukka, P.; Skytta, J.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1999-01-01

BACKGROUND: New methods of R-R interval variability based on fractal scaling and nonlinear dynamics ("chaos theory") may give new insights into heart rate dynamics. The aims of this study were to (1) systematically characterize and quantify the effects of aging from early childhood to advanced age on 24-hour heart rate dynamics in healthy subjects; (2) compare age-related changes in conventional time- and frequency-domain measures with changes in newly derived measures based on fractal scaling and complexity (chaos) theory; and (3) further test the hypothesis that there is loss of complexity and altered fractal scaling of heart rate dynamics with advanced age. METHODS AND RESULTS: The relationship between age and cardiac interbeat (R-R) interval dynamics from childhood to senescence was studied in 114 healthy subjects (age range, 1 to 82 years) by measurement of the slope, beta, of the power-law regression line (log power-log frequency) of R-R interval variability (10(-4) to 10(-2) Hz), approximate entropy (ApEn), short-term (alpha(1)) and intermediate-term (alpha(2)) fractal scaling exponents obtained by detrended fluctuation analysis, and traditional time- and frequency-domain measures from 24-hour ECG recordings. Compared with young adults (<40 years old, n=29), children (<15 years old, n=27) showed similar complexity (ApEn) and fractal correlation properties (alpha(1), alpha(2), beta) of R-R interval dynamics despite lower spectral and time-domain measures. Progressive loss of complexity (decreased ApEn, r=-0.69, P<0.001) and alterations of long-term fractal-like heart rate behavior (increased alpha(2), r=0.63, decreased beta, r=-0.60, P<0.001 for both) were observed thereafter from middle age (40 to 60 years, n=29) to old age (>60 years, n=29). CONCLUSIONS: Cardiac interbeat interval dynamics change markedly from childhood to old age in healthy subjects. Children show complexity and fractal correlation properties of R-R interval time series comparable to those of young adults, despite lower overall heart rate variability. Healthy aging is associated with R-R interval dynamics showing higher regularity and altered fractal scaling consistent with a loss of complex variability.

Effects of complex carbon addition to soil CO2 efflux and isotopic composition to soils near dead and live piñon pine trees

NASA Astrophysics Data System (ADS)

Powers, H.; McDowell, N.; Breecker, D. O.

2010-12-01

We test the hypothesis that soils collected near dead and living pinus edulous (piñon pine) trees should show a difference in their capacities to decompose complex carbon compounds. Since soils near dead trees have a large amount of cellulose and other complex carbon, the soil microbial community should be selected to metabolize cellulose. We collected soils from both live and dead piñon trees, added cellulose to half of the replicates, and placed them in microcosms for incubation. The microcosms were periodically sampled by a trace gas analyzer (TGA100, Campbell Scientific, USA) for CO2 concentration and δ13C and δ18O analysis. We found that CO2 evolution rates from live soils were significantly higher than rates from dead soils (1.1 and 0.6 ug CO2 g-1 soil s-1 respectively); soils with added cellulose displayed higher rates (1.1 and 0.8 and ug CO2 g-1 soil s-1). We did not see any significant differences in δ13C values between treatments, but there was a difference in δ18O between soils treated with cellulose and soils with no cellulose. Soils from both dead and live trees showed an increase in CO2 efflux when cellulose was added; however there was no distinguishable difference in efflux rate between live and dead soils in the cellulose added treatments.

Measuring disorganized speech in schizophrenia: automated analysis explains variance in cognitive deficits beyond clinician-rated scales.

PubMed

Minor, K S; Willits, J A; Marggraf, M P; Jones, M N; Lysaker, P H

2018-04-25

Conveying information cohesively is an essential element of communication that is disrupted in schizophrenia. These disruptions are typically expressed through disorganized symptoms, which have been linked to neurocognitive, social cognitive, and metacognitive deficits. Automated analysis can objectively assess disorganization within sentences, between sentences, and across paragraphs by comparing explicit communication to a large text corpus. Little work in schizophrenia has tested: (1) links between disorganized symptoms measured via automated analysis and neurocognition, social cognition, or metacognition; and (2) if automated analysis explains incremental variance in cognitive processes beyond clinician-rated scales. Disorganization was measured in schizophrenia (n = 81) with Coh-Metrix 3.0, an automated program that calculates basic and complex language indices. Trained staff also assessed neurocognition, social cognition, metacognition, and clinician-rated disorganization. Findings showed that all three cognitive processes were significantly associated with at least one automated index of disorganization. When automated analysis was compared with a clinician-rated scale, it accounted for significant variance in neurocognition and metacognition beyond the clinician-rated measure. When combined, these two methods explained 28-31% of the variance in neurocognition, social cognition, and metacognition. This study illustrated how automated analysis can highlight the specific role of disorganization in neurocognition, social cognition, and metacognition. Generally, those with poor cognition also displayed more disorganization in their speech-making it difficult for listeners to process essential information needed to tie the speaker's ideas together. Our findings showcase how implementing a mixed-methods approach in schizophrenia can explain substantial variance in cognitive processes.

Uncertainty analysis of multi-rate kinetics of uranium desorption from sediments

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

Zhang, Xiaoying; Liu, Chongxuan; Hu, Bill X.

2014-01-01

A multi-rate expression for uranyl [U(VI)] surface complexation reactions has been proposed to describe diffusion-limited U(VI) sorption/desorption in heterogeneous subsurface sediments. An important assumption in the rate expression is that its rate constants follow a certain type probability distribution. In this paper, a Bayes-based, Differential Evolution Markov Chain method was used to assess the distribution assumption and to analyze parameter and model structure uncertainties. U(VI) desorption from a contaminated sediment at the US Hanford 300 Area, Washington was used as an example for detail analysis. The results indicated that: 1) the rate constants in the multi-rate expression contain uneven uncertaintiesmore » with slower rate constants having relative larger uncertainties; 2) the lognormal distribution is an effective assumption for the rate constants in the multi-rate model to simualte U(VI) desorption; 3) however, long-term prediction and its uncertainty may be significantly biased by the lognormal assumption for the smaller rate constants; and 4) both parameter and model structure uncertainties can affect the extrapolation of the multi-rate model with a larger uncertainty from the model structure. The results provide important insights into the factors contributing to the uncertainties of the multi-rate expression commonly used to describe the diffusion or mixing-limited sorption/desorption of both organic and inorganic contaminants in subsurface sediments.« less

Quantitative semi-automated analysis of morphogenesis with single-cell resolution in complex embryos

PubMed Central

Giurumescu, Claudiu A.; Kang, Sukryool; Planchon, Thomas A.; Betzig, Eric; Bloomekatz, Joshua; Yelon, Deborah; Cosman, Pamela; Chisholm, Andrew D.

2012-01-01

A quantitative understanding of tissue morphogenesis requires description of the movements of individual cells in space and over time. In transparent embryos, such as C. elegans, fluorescently labeled nuclei can be imaged in three-dimensional time-lapse (4D) movies and automatically tracked through early cleavage divisions up to ~350 nuclei. A similar analysis of later stages of C. elegans development has been challenging owing to the increased error rates of automated tracking of large numbers of densely packed nuclei. We present Nucleitracker4D, a freely available software solution for tracking nuclei in complex embryos that integrates automated tracking of nuclei in local searches with manual curation. Using these methods, we have been able to track >99% of all nuclei generated in the C. elegans embryo. Our analysis reveals that ventral enclosure of the epidermis is accompanied by complex coordinated migration of the neuronal substrate. We can efficiently track large numbers of migrating nuclei in 4D movies of zebrafish cardiac morphogenesis, suggesting that this approach is generally useful in situations in which the number, packing or dynamics of nuclei present challenges for automated tracking. PMID:23052905

Heart rate and respiratory rhythm dynamics on ascent to high altitude.

PubMed Central

Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

1995-01-01

OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress. PMID:7488453

Heart rate and respiratory rhythm dynamics on ascent to high altitude

NASA Technical Reports Server (NTRS)

Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

1995-01-01

OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.

Magnesium degradation as determined by artificial neural networks.

PubMed

Willumeit, Regine; Feyerabend, Frank; Huber, Norbert

2013-11-01

Magnesium degradation under physiological conditions is a highly complex process in which temperature, the use of cell culture growth medium and the presence of CO2, O2 and proteins can influence the corrosion rate and the composition of the resulting corrosion layer. Due to the complexity of this process it is almost impossible to predict the parameters that are most important and whether some parameters have a synergistic effect on the corrosion rate. Artificial neural networks are a mathematical tool that can be used to approximate and analyse non-linear problems with multiple inputs. In this work we present the first analysis of corrosion data obtained using this method, which reveals that CO2 and the composition of the buffer system play a crucial role in the corrosion of magnesium, whereas O2, proteins and temperature play a less prominent role. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Direct visualization reveals kinetics of meiotic chromosome synapsis

DOE PAGES

Rog, Ofer; Dernburg, Abby  F.

2015-03-17

The synaptonemal complex (SC) is a conserved protein complex that stabilizes interactions along homologous chromosomes (homologs) during meiosis. The SC regulates genetic exchanges between homologs, thereby enabling reductional division and the production of haploid gametes. Here, we directly observe SC assembly (synapsis) by optimizing methods for long-term fluorescence recording in C. elegans. We report that synapsis initiates independently on each chromosome pair at or near pairing centers—specialized regions required for homolog associations. Once initiated, the SC extends rapidly and mostly irreversibly to chromosome ends. Quantitation of SC initiation frequencies and extension rates reveals that initiation is a rate-limiting step inmore » homolog interactions. Eliminating the dynein-driven chromosome movements that accompany synapsis severely retards SC extension, revealing a new role for these conserved motions. This work provides the first opportunity to directly observe and quantify key aspects of meiotic chromosome interactions and will enable future in vivo analysis of germline processes.« less

Linear and nonlinear features of fetal heart rate on the assessment of fetal development in the course of pregnancy and the impact of fetal gender.

PubMed

Spyridou, K; Chouvarda, I; Hadjileontiadis, L; Maglaveras, N

2018-01-30

This work aims to investigate the impact of gestational age and fetal gender on fetal heart rate (FHR) tracings. Different linear and nonlinear parameters indicating correlation or complexity were used to study the influence of fetal age and gender on FHR tracings. The signals were recorded from 99 normal pregnant women in a singleton pregnancy at gestational ages from 28 to 40 weeks, before the onset of labor. There were 56 female fetuses and 43 male. Analysis of FHR shows that the means as well as measures of irregularity of FHR, such as approximate entropy and algorithmic complexity, decrease as gestation progresses. There were also indications that mutual information and multiscale entropy were lower in male fetuses in early pregnancy. Fetal age and gender seem to influence FHR tracings. Taking this into consideration would improve the interpretation of FHR monitoring.

Interpreting expressive performance through listener judgments of musical tension

PubMed Central

Farbood, Morwaread M.; Upham, Finn

2013-01-01

This study examines listener judgments of musical tension for a recording of a Schubert song and its harmonic reduction. Continuous tension ratings collected in an experiment and quantitative descriptions of the piece's musical features, include dynamics, pitch height, harmony, onset frequency, and tempo, were analyzed from two different angles. In the first part of the analysis, the different processing timescales for disparate features contributing to tension were explored through the optimization of a predictive tension model. The results revealed the optimal time windows for harmony were considerably longer (~22 s) than for any other feature (~1–4 s). In the second part of the analysis, tension ratings for the individual verses of the song and its harmonic reduction were examined and compared. The results showed that although the average tension ratings between verses were very similar, differences in how and when participants reported tension changes highlighted performance decisions made in the interpretation of the score, ambiguity in tension implications of the music, and the potential importance of contrast between verses and phrases. Analysis of the tension ratings for the harmonic reduction also provided a new perspective for better understanding how complex musical features inform listener tension judgments. PMID:24416024

Analysis of Maneuvering Targets with Complex Motions by Two-Dimensional Product Modified Lv's Distribution for Quadratic Frequency Modulation Signals.

PubMed

Jing, Fulong; Jiao, Shuhong; Hou, Changbo; Si, Weijian; Wang, Yu

2017-06-21

For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF) and modified scaled Fourier transform (mSFT), an effective parameter estimation algorithm is proposed-referred to as the Two-Dimensional product modified Lv's distribution (2D-PMLVD)-for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT) and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.

A novel role for WAVE1 in controlling actin network growth rate and architecture

PubMed Central

Sweeney, Meredith O.; Collins, Agnieszka; Padrick, Shae B.; Goode, Bruce L.

2015-01-01

Branched actin filament networks in cells are assembled through the combined activities of Arp2/3 complex and different WASP/WAVE proteins. Here we used TIRF and electron microscopy to directly compare for the first time the assembly kinetics and architectures of actin filament networks produced by Arp2/3 complex and dimerized VCA regions of WAVE1, WAVE2, or N-WASP. WAVE1 produced strikingly different networks from WAVE2 or N-WASP, which comprised unexpectedly short filaments. Further analysis showed that the WAVE1-specific activity stemmed from an inhibitory effect on filament elongation both in the presence and absence of Arp2/3 complex, which was observed even at low stoichiometries of WAVE1 to actin monomers, precluding an effect from monomer sequestration. Using a series of VCA chimeras, we mapped the elongation inhibitory effects of WAVE1 to its WH2 (“V”) domain. Further, mutating a single conserved lysine residue potently disrupted WAVE1's inhibitory effects. Taken together, our results show that WAVE1 has unique activities independent of Arp2/3 complex that can govern both the growth rates and architectures of actin filament networks. Such activities may underlie previously observed differences between the cellular functions of WAVE1 and WAVE2. PMID:25473116

Anaerobic treatment of complex chemical wastewater in a sequencing batch biofilm reactor: process optimization and evaluation of factor interactions using the Taguchi dynamic DOE methodology.

PubMed

Venkata Mohan, S; Chandrasekhara Rao, N; Krishna Prasad, K; Murali Krishna, P; Sreenivas Rao, R; Sarma, P N

2005-06-20

The Taguchi robust experimental design (DOE) methodology has been applied on a dynamic anaerobic process treating complex wastewater by an anaerobic sequencing batch biofilm reactor (AnSBBR). For optimizing the process as well as to evaluate the influence of different factors on the process, the uncontrollable (noise) factors have been considered. The Taguchi methodology adopting dynamic approach is the first of its kind for studying anaerobic process evaluation and process optimization. The designed experimental methodology consisted of four phases--planning, conducting, analysis, and validation connected sequence-wise to achieve the overall optimization. In the experimental design, five controllable factors, i.e., organic loading rate (OLR), inlet pH, biodegradability (BOD/COD ratio), temperature, and sulfate concentration, along with the two uncontrollable (noise) factors, volatile fatty acids (VFA) and alkalinity at two levels were considered for optimization of the anae robic system. Thirty-two anaerobic experiments were conducted with a different combination of factors and the results obtained in terms of substrate degradation rates were processed in Qualitek-4 software to study the main effect of individual factors, interaction between the individual factors, and signal-to-noise (S/N) ratio analysis. Attempts were also made to achieve optimum conditions. Studies on the influence of individual factors on process performance revealed the intensive effect of OLR. In multiple factor interaction studies, biodegradability with other factors, such as temperature, pH, and sulfate have shown maximum influence over the process performance. The optimum conditions for the efficient performance of the anaerobic system in treating complex wastewater by considering dynamic (noise) factors obtained are higher organic loading rate of 3.5 Kg COD/m3 day, neutral pH with high biodegradability (BOD/COD ratio of 0.5), along with mesophilic temperature range (40 degrees C), and low sulfate concentration (700 mg/L). The optimization resulted in enhanced anaerobic performance (56.7%) from a substrate degradation rate (SDR) of 1.99 to 3.13 Kg COD/m3 day. Considering the obtained optimum factors, further validation experiments were carried out, which showed enhanced process performance (3.04 Kg COD/m3-day from 1.99 Kg COD/m3 day) accounting for 52.13% improvement with the optimized process conditions. The proposed method facilitated a systematic mathematical approach to understand the complex multi-species manifested anaerobic process treating complex chemical wastewater by considering the uncontrollable factors. Copyright (c) 2005 Wiley Periodicals, Inc.

A new metric for assessing IMRT modulation complexity and plan deliverability.

PubMed

McNiven, Andrea L; Sharpe, Michael B; Purdie, Thomas G

2010-02-01

To evaluate the utility of a new complexity metric, the modulation complexity score (MCS), in the treatment planning and quality assurance processes and to evaluate the relationship of the metric with deliverability. A multisite (breast, rectum, prostate, prostate bed, lung, and head and neck) and site-specific (lung) dosimetric evaluation has been completed. The MCS was calculated for each beam and the overall treatment plan. A 2D diode array (MapCHECK, Sun Nuclear, Melbourne, FL) was used to acquire measurements for each beam. The measured and planned dose (PINNACLE3, Phillips, Madison, WI) was evaluated using different percent differences and distance to agreement (DTA) criteria (3%/ 3 mm and 2%/ 1 mm) and the relationship between the dosimetric results and complexity (as measured by the MCS or simple beam parameters) assessed. For the multisite analysis (243 plans total), the mean MCS scores for each treatment site were breast (0.92), rectum (0.858), prostate (0.837), prostate bed (0.652), lung (0.631), and head and neck (0.356). The MCS allowed for compilation of treatment site-specific statistics, which is useful for comparing different techniques, as well as for comparison of individual treatment plans with the typical complexity levels. For the six plans selected for dosimetry, the average diode percent pass rate was 98.7% (minimum of 96%) for 3%/3 mm evaluation criteria. The average difference in absolute dose measurement between the planned and measured dose was 1.7 cGy. The detailed lung analysis also showed excellent agreement between the measured and planned dose, as all beams had a diode percentage pass rate for 3%/3 mm criteria of greater than 95.9%, with an average pass rate of 99.0%. The average absolute maximum dose difference for the lung plans was 0.7 cGy. There was no direct correlation between the MCS and simple beam parameters which could be used as a surrogate for complexity level (i.e., number of segments or MU). An evaluation criterion of 2%/ 1 mm reliably allowed for the identification of beams that are dosimetrically robust. In this study we defined a robust beam or plan as one that maintained a diode percentage pass rate greater than 90% at 2%/ 1 mm, indicating delivery that was deemed accurate when compared to the planned dose, even under stricter evaluation criterion. MCS and MU threshold criteria were determined by defining a required specificity of 1.0. A MCS threshold of 0.8 allowed for identification of robust deliverability with a sensitivity of 0.36. In contrast, MU had a lower sensitivity of 0.23 for a threshold of 50 MU. The MCS allows for a quantitative assessment of plan complexity, on a fixed scale, that can be applied to all treatment sites and can provide more information related to dose delivery than simple beam parameters. This could prove useful throughout the entire treatment planning and QA process.

Simultaneous separation of inorganic anions and metal-citrate complexes on a zwitterionic stationary phase with on-column complexation.

PubMed

Nesterenko, Ekaterina P; Nesterenko, Pavel N; Paull, Brett

2008-12-05

The retention and separation selectivity of inorganic anions and on-column derivatised negatively charged citrate or oxalate metal complexes on reversed-phase stationary phases dynamically coated with N-(dodecyl-N,N-dimethylammonio)undecanoate (DDMAU) has been investigated. The retention mechanism for the metal-citrate complexes was predominantly anion exchange, although the amphoteric/zwitterionic nature of the stationary phase coating undoubtedly also contributed to the unusual separation selectivity shown. A mixture of 10 inorganic anions and metal cations was achieved using a 20 cm monolithic DDMAU modified column and a 1 mM citrate eluent, pH 4.0, flow rate equal to 0.8 mL/min. Selectivity was found to be strongly pH dependent, allowing additional scope for manipulation of solute retention, and thus application to complex samples. This is illustrated with the analysis of an acidic mine drainage sample with a range of inorganic anions and transition metal cations, varying significantly in their concentrations levels.

Charge–transfer reaction of 2,3-dichloro-1,4-naphthoquinone with crizotinib: Spectrophotometric study, computational molecular modeling and use in development of microwell assay for crizotinib

PubMed Central

Alzoman, Nourah Z.; Alshehri, Jamilah M.; Darwish, Ibrahim A.; Khalil, Nasr Y.; Abdel-Rahman, Hamdy M.

2014-01-01

The reaction of 2,3-dichloro-1,4-naphthoquinone (DCNQ) with crizotinib (CZT; a novel drug used for treatment of non-small cell lung cancer) was investigated in different solvents of varying dielectric constants and polarity indexes. The reaction produced a red-colored product. Spectrophotometric investigations confirmed that the reaction proceeded through charge–transfer (CT) complex formation. The molar absorptivity of the complex was found to be linearly correlated with the dielectric constant and polarity index of the solvent; the correlation coefficients were 0.9567 and 0.9069, respectively. The stoichiometric ratio of DCNQ:CZT was found to be 2:1 and the association constant of the complex was found to be 1.07 × 102 l/mol. The kinetics of the reaction was studied; the order of the reaction, rate and rate constant were determined. Computational molecular modeling for the complex between DCNQ and CZT was conducted, the sites of interaction on CZT molecule were determined, and the mechanism of the reaction was postulated. The reaction was employed as a basis in the development of a novel 96-microwell assay for CZT in a linear range of 4–500 μg/ml. The assay limits of detection and quantitation were 2.06 and 6.23 μg/ml, respectively. The assay was validated as per the guidelines of the International Conference on Harmonization (ICH) and successfully applied to the analysis of CZT in its bulk and capsules with good accuracy and precision. The assay has high throughput and consumes a minimum volume of organic solvents thus it reduces the exposures of the analysts to the toxic effects of organic solvents, and significantly reduces the analysis cost. PMID:25685046

Automation of a high risk medication regime algorithm in a home health care population.

PubMed

Olson, Catherine H; Dierich, Mary; Westra, Bonnie L

2014-10-01

Create an automated algorithm for predicting elderly patients' medication-related risks for readmission and validate it by comparing results with a manual analysis of the same patient population. Outcome and Assessment Information Set (OASIS) and medication data were reused from a previous, manual study of 911 patients from 15 Medicare-certified home health care agencies. The medication data was converted into standardized drug codes using APIs managed by the National Library of Medicine (NLM), and then integrated in an automated algorithm that calculates patients' high risk medication regime scores (HRMRs). A comparison of the results between algorithm and manual process was conducted to determine how frequently the HRMR scores were derived which are predictive of readmission. HRMR scores are composed of polypharmacy (number of drugs), Potentially Inappropriate Medications (PIM) (drugs risky to the elderly), and Medication Regimen Complexity Index (MRCI) (complex dose forms, instructions or administration). The algorithm produced polypharmacy, PIM, and MRCI scores that matched with 99%, 87% and 99% of the scores, respectively, from the manual analysis. Imperfect match rates resulted from discrepancies in how drugs were classified and coded by the manual analysis vs. the automated algorithm. HRMR rules lack clarity, resulting in clinical judgments for manual coding that were difficult to replicate in the automated analysis. The high comparison rates for the three measures suggest that an automated clinical tool could use patients' medication records to predict their risks of avoidable readmissions. Copyright © 2014 Elsevier Inc. All rights reserved.

Impact of pharmacy benefit design on prescription drug utilization: a fixed effects analysis of plan sponsor data.

PubMed

Roebuck, M Christopher; Liberman, Joshua N

2009-06-01

To study the impact of various elements of pharmacy benefit design on both the absolute and relative utilization of generics, brands, retail pharmacy, and mail service. Panel data on 1,074 plan sponsors covering 21.6 million individuals over 12 calendar quarters (2005-2007). A retrospective analysis of pharmacy claims. To control for potential endogeneity, linear fixed effects models were estimated for each of six dependent variables: the generic utilization rate, the brand utilization rate, the generic dispensing rate (GDR), the retail pharmacy utilization rate, the mail service utilization rate, and the mail distribution rate. Most member cost-share variables were nonlinearly associated with changes in prescription drug utilization. Marginal effects were generally greater in magnitude for brand out-of-pocket costs than for generic out-of-pocket costs. Time dummies, as well as other pharmacy benefit design elements, also yielded significant results. Prior estimates of the effect of member cost sharing on prescription drug utilization may be biased if complex benefit designs, mail service fulfillment, and unmeasured factors such as pharmaceutical pipelines are not accounted for. Commonly cited relative utilization metrics, such as GDR, may be misleading if not examined alongside absolute prescription drug utilization.

Drought-Related Mortality in Pinyon-Juniper Woodlands: A Test Case for the FIA Annual Inventory System

Treesearch

John D. Shaw

2006-01-01

Several years of drought in the Southwest United States are associated with widespread mortality in the pinyon-juniper forest type. A complex of drought, insects, and disease is responsible for pinyon mortality rates approaching 100 percent in some areas, while other areas have experienced little or no mortality. Implementation of the Forest Inventory and Analysis...

Analysis of high speed flow, thermal and structural interactions

NASA Technical Reports Server (NTRS)

Thornton, Earl A.

1994-01-01

Research for this grant focused on the following tasks: (1) the prediction of severe, localized aerodynamic heating for complex, high speed flows; (2) finite element adaptive refinement methodology for multi-disciplinary analyses; (3) the prediction of thermoviscoplastic structural response with rate-dependent effects and large deformations; (4) thermoviscoplastic constitutive models for metals; and (5) coolant flow/structural heat transfer analyses.

Using steady-state equations for transient flow calculation in natural gas pipelines

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

Maddox, R.N.; Zhou, P.

1984-04-02

Maddox and Zhou have extended their technique for calculating the unsteady-state behavior of straight gas pipelines to complex pipeline systems and networks. After developing the steady-state flow rate and pressure profile for each pipe in the network, analysts can perform the transient-state analysis in the real-time step-wise manner described for this technique.

Efficient use of single molecule time traces to resolve kinetic rates, models and uncertainties

NASA Astrophysics Data System (ADS)

Schmid, Sonja; Hugel, Thorsten

2018-03-01

Single molecule time traces reveal the time evolution of unsynchronized kinetic systems. Especially single molecule Förster resonance energy transfer (smFRET) provides access to enzymatically important time scales, combined with molecular distance resolution and minimal interference with the sample. Yet the kinetic analysis of smFRET time traces is complicated by experimental shortcomings—such as photo-bleaching and noise. Here we recapitulate the fundamental limits of single molecule fluorescence that render the classic, dwell-time based kinetic analysis unsuitable. In contrast, our Single Molecule Analysis of Complex Kinetic Sequences (SMACKS) considers every data point and combines the information of many short traces in one global kinetic rate model. We demonstrate the potential of SMACKS by resolving the small kinetic effects caused by different ionic strengths in the chaperone protein Hsp90. These results show an unexpected interrelation between conformational dynamics and ATPase activity in Hsp90.

Family medicine outpatient encounters are more complex than those of cardiology and psychiatry.

PubMed

Katerndahl, David; Wood, Robert; Jaén, Carlos Roberto

2011-01-01

comparison studies suggest that the guideline-concordant care provided for specific medical conditions is less optimal in primary care compared with cardiology and psychiatry settings. The purpose of this study is to estimate the relative complexity of patient encounters in general/family practice, cardiology, and psychiatry settings. secondary analysis of the 2000 National Ambulatory Medical Care Survey data for ambulatory patients seen in general/family practice, cardiology, and psychiatry settings was performed. The complexity for each variable was estimated as the quantity weighted by variability and diversity. there is minimal difference in the unadjusted input and total encounter complexity of general/family practice and cardiology; psychiatry's input is less complex. Cardiology encounters involved more input quantitatively, but the diversity of general/family practice input eliminated the difference. Cardiology also involved more complex output. However, when the duration of visit is factored in, the complexity of care provided per hour in general/family practice is 33% more relative to cardiology and 5 times more relative to psychiatry. care during family physician visits is more complex per hour than the care during visits to cardiologists or psychiatrists. This may account for a lower rate of completion of process items measured for quality of care.

Pulse radiolysis studies of the reactions of bromine atoms and dimethyl sulfoxide bromine atom complexes with alcohols

NASA Astrophysics Data System (ADS)

Sumiyoshi, Takashi; Fujiyoshi, Ryoko; Katagiri, Miho; Sawamura, Sadashi

2007-05-01

Dimethylsulfoxide (DMSO)-Br complexes were generated by pulse radiolysis of DMSO/bromomethane mixtures and the formation mechanism and spectral characteristics of the formed complexes were investigated in detail. The rate constant for the reaction of bromine atoms with DMSO and the extinction coefficient of the complex were obtained to be 4.6×10 9 M -1 s -1 and 6300 M -1 cm -1 at the absorption maximum of 430 nm. Rate constants for the reaction of bromine atoms with a series of alcohols were determined in CBrCl 3 solutions applying a competitive kinetic method using the DMSO-Br complex as the reference system. The obtained rate constants were ˜10 8 M -1 s -1, one or two orders larger than those reported for highly polar solvents. Rate constants of DMSO-Br complexes with alcohols were determined to be ˜ 10 7 M -1 s -1. A comparison of the reactivities of Br atoms and DMSO-Br complexes with those of chlorine atoms and chlorine atom complexes which are ascribed to hydrogen abstracting reactants strongly indicates that hydrogen abstraction from alcohols is not the rate determining step in the case of Br atoms and DMSO-Br complexes.

Radiotherapy and nipple-areolar complex necrosis after nipple-sparing mastectomy: a systematic review and meta-analysis.

PubMed

Zheng, Yajuan; Zhong, Miaochun; Ni, Chao; Yuan, Hongjun; Zhang, Jingxia

2017-03-01

To perform a meta-analysis to determine the effect of radiotherapy (RT) on nipple-areolar complex (NAC) and skin flap necrosis, and local recurrence in women who undergo nipple-sparing mastectomy (NSM) and immediate breast reconstruction. Medline, PubMed, Cochrane, and Google Scholar databases were searched until October 16, 2015. Randomized-controlled-trials, prospective, retrospective, and cohort studies were included. The primary outcome was the NAC necrosis rate, and the secondary outcomes were the skin flap necrosis and local recurrence rates. Of 186 studies identified, 2 prospective and 5 retrospective studies including a total of 3692 patients were included in the meta-analysis. Five, 3, and 2 studies reported data of NAC necrosis (3461 breasts), skin flap necrosis (2490 breasts), and local recurrence (988 breasts), respectively. Pooled results showed no difference in the odds of NAC necrosis [odds ratio (OR) = 1.250, 95% confidence interval (CI) 0.481-3.247, P = 0.647], or local recurrence (OR = 0.564, 95% CI 0.056-5.710, P = 0.627) between patients who received and did not receive RT. Patients treated with RT had a higher likelihood of skin flap necrosis (OR = 2.534, 95% CI 1.720-3.735, P < 0.001). Significant heterogeneity, however, was noted in the analysis of NAC and local recurrence. Because of the limitations of the small number of studies and heterogeneity in the analysis, this study does not allow drawing any definitive conclusions and highlights the need of well-controlled trials to determine the effect of RT in patients undergoing NSM.

C++, objected-oriented programming, and astronomical data models

NASA Technical Reports Server (NTRS)

Farris, A.

1992-01-01

Contemporary astronomy is characterized by increasingly complex instruments and observational techniques, higher data collection rates, and large data archives, placing severe stress on software analysis systems. The object-oriented paradigm represents a significant new approach to software design and implementation that holds great promise for dealing with this increased complexity. The basic concepts of this approach will be characterized in contrast to more traditional procedure-oriented approaches. The fundamental features of objected-oriented programming will be discussed from a C++ programming language perspective, using examples familiar to astronomers. This discussion will focus on objects, classes and their relevance to the data type system; the principle of information hiding; and the use of inheritance to implement generalization/specialization relationships. Drawing on the object-oriented approach, features of a new database model to support astronomical data analysis will be presented.

Impact of PID on industrial rooftop PV-installations

NASA Astrophysics Data System (ADS)

Buerhop, Claudia; Fecher, Frank W.; Pickel, Tobias; Patel, Tirth; Zetzmann, Cornelia; Camus, Christian; Hauch, Jens; Brabec, Christoph J.

2017-08-01

Potential induced degradation (PID) causes severe damage and financial losses even in modern PV-installations. In Germany, approximately 19% of PV-installations suffer from PID and resulting power loss. This paper focuses on the impact of PID in real installations and how different evaluated time intervals influence the performance ratio (PR) and the determined degradation rate. The analysis focuses exemplarily on a 314 kWp PV-system in the Atlantic coastal climate. IR-imaging is used for identifying PID without operation interruption. Historic electric performance data are available from a monitoring system for several years on system level, string level as well as punctually measured module string IV- curves. The data sets are combined for understanding the PID behavior of this PV plant. The number of PID affected cells within a string varies strongly between 1 to 22% with the string position on the building complex. With increasing number of PID-affected cells the performance ratio decreases down to 60% for daily and monthly periods. Local differences in PID evolution rates are identified. An average PR-reduction of -3.65% per year is found for the PV-plant. On the string level the degradation rate varied up to 8.8% per year depending on the string position and the time period. The analysis reveals that PID generation and evolution in roof-top installations on industrial buildings with locally varying operation conditions can be fairly complex. The results yield that local operating conditions, e.g. ambient weather conditions as well as surrounding conditions on an industrial building, seem to have a dominating impact on the PID evolution rate.

Effect of Methamphetamine Dependence on Heart Rate Variability

PubMed Central

Henry, Brook L.; Minassian, Arpi; Perry, William

2010-01-01

Background Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology, and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. Method HRV was assessed using time domain, frequency domain, and nonlinear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. Results The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Conclusion Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use. PMID:21182570

Linked Sensitivity Analysis, Calibration, and Uncertainty Analysis Using a System Dynamics Model for Stroke Comparative Effectiveness Research.

PubMed

Tian, Yuan; Hassmiller Lich, Kristen; Osgood, Nathaniel D; Eom, Kirsten; Matchar, David B

2016-11-01

As health services researchers and decision makers tackle more difficult problems using simulation models, the number of parameters and the corresponding degree of uncertainty have increased. This often results in reduced confidence in such complex models to guide decision making. To demonstrate a systematic approach of linked sensitivity analysis, calibration, and uncertainty analysis to improve confidence in complex models. Four techniques were integrated and applied to a System Dynamics stroke model of US veterans, which was developed to inform systemwide intervention and research planning: Morris method (sensitivity analysis), multistart Powell hill-climbing algorithm and generalized likelihood uncertainty estimation (calibration), and Monte Carlo simulation (uncertainty analysis). Of 60 uncertain parameters, sensitivity analysis identified 29 needing calibration, 7 that did not need calibration but significantly influenced key stroke outcomes, and 24 not influential to calibration or stroke outcomes that were fixed at their best guess values. One thousand alternative well-calibrated baselines were obtained to reflect calibration uncertainty and brought into uncertainty analysis. The initial stroke incidence rate among veterans was identified as the most influential uncertain parameter, for which further data should be collected. That said, accounting for current uncertainty, the analysis of 15 distinct prevention and treatment interventions provided a robust conclusion that hypertension control for all veterans would yield the largest gain in quality-adjusted life years. For complex health care models, a mixed approach was applied to examine the uncertainty surrounding key stroke outcomes and the robustness of conclusions. We demonstrate that this rigorous approach can be practical and advocate for such analysis to promote understanding of the limits of certainty in applying models to current decisions and to guide future data collection. © The Author(s) 2016.

Combined analysis of modeled and monitored SO2 concentrations at a complex smelting facility.

PubMed

Rehbein, Peter J G; Kennedy, Michael G; Cotsman, David J; Campeau, Madonna A; Greenfield, Monika M; Annett, Melissa A; Lepage, Mike F

2014-03-01

Vale Canada Limited owns and operates a large nickel smelting facility located in Sudbury, Ontario. This is a complex facility with many sources of SO2 emissions, including a mix of source types ranging from passive building roof vents to North America's tallest stack. In addition, as this facility performs batch operations, there is significant variability in the emission rates depending on the operations that are occurring. Although SO2 emission rates for many of the sources have been measured by source testing, the reliability of these emission rates has not been tested from a dispersion modeling perspective. This facility is a significant source of SO2 in the local region, making it critical that when modeling the emissions from this facility for regulatory or other purposes, that the resulting concentrations are representative of what would actually be measured or otherwise observed. To assess the accuracy of the modeling, a detailed analysis of modeled and monitored data for SO2 at the facility was performed. A mobile SO2 monitor sampled at five locations downwind of different source groups for different wind directions resulting in a total of 168 hr of valid data that could be used for the modeled to monitored results comparison. The facility was modeled in AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model) using site-specific meteorological data such that the modeled periods coincided with the same times as the monitored events. In addition, great effort was invested into estimating the actual SO2 emission rates that would likely be occurring during each of the monitoring events. SO2 concentrations were modeled for receptors around each monitoring location so that the modeled data could be directly compared with the monitored data. The modeled and monitored concentrations were compared and showed that there were no systematic biases in the modeled concentrations. This paper is a case study of a Combined Analysis of Modelled and Monitored Data (CAMM), which is an approach promulgated within air quality regulations in the Province of Ontario, Canada. Although combining dispersion models and monitoring data to estimate or refine estimates of source emission rates is not a new technique, this study shows how, with a high degree of rigor in the design of the monitoring and filtering of the data, it can be applied to a large industrial facility, with a variety of emission sources. The comparison of modeled and monitored SO2 concentrations in this case study also provides an illustration of the AERMOD model performance for a large industrial complex with many sources, at short time scales in comparison with monitored data. Overall, this analysis demonstrated that the AERMOD model performed well.

Simulating evolution of protein complexes through gene duplication and co-option.

PubMed

Haarsma, Loren; Nelesen, Serita; VanAndel, Ethan; Lamine, James; VandeHaar, Peter

2016-06-21

We present a model of the evolution of protein complexes with novel functions through gene duplication, mutation, and co-option. Under a wide variety of input parameters, digital organisms evolve complexes of 2-5 bound proteins which have novel functions but whose component proteins are not independently functional. Evolution of complexes with novel functions happens more quickly as gene duplication rates increase, point mutation rates increase, protein complex functional probability increases, protein complex functional strength increases, and protein family size decreases. Evolution of complexity is inhibited when the metabolic costs of making proteins exceeds the fitness gain of having functional proteins, or when point mutation rates get so large the functional proteins undergo deleterious mutations faster than new functional complexes can evolve. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and characterization of lecithin stabilized glibenclamide nanocrystals for enhanced solubility and drug delivery.

PubMed

Kumar, B Sajeev; Saraswathi, R; Kumar, K Venkates; Jha, S K; Venkates, D P; Dhanaraj, S A

2014-05-01

Novel LNCs (lipid nanocrystals) were developed with an aim to improve the solubility, stability and targeting efficiency of the model drug glibenclamide (GLB). PEG 20000, Tween 80 and soybean lecithin were used as polymer, surfactant and complexing agent, respectively. GLB nanocrystals (NCs) were prepared by precipitation process and complexed using hot and cold melt technique. The LNCs were evaluated by drug loading, saturation solubility (SL), optical clarity, in vitro dissolution, solid state characterization, in vivo and stability analysis. LNCs exhibited a threefold increase in SL and a higher dissolution rate than GLB. The percentage dissolution efficiency was found to decrease with increase in PEG 20000. The average particle size was in the range of 155-842 nm and zeta potential values tend to increase after complexation. X-ray powder diffractometry and differential scanning calorimetry results proved the crystallinity prevailed in the samples. Spherical shaped particles (<1000 nm) with a lipid coat on the surface were observed in scanning electron microscopy analysis. Fourier transform infrared results proved the absence of interaction between drug and polymer and stability study findings proved that LNCs were stable. In vivo study findings showed a decrease in drug concentration to pancreas in male Wistar rats. It can be concluded that LNCs are could offer enhanced solubility, dissolution rate and stability for poorly water soluble drugs. The targeting efficiency of LNCs was decreased and further membrane permeability studies ought to be carried out.

Nonstent Combination Interventional Therapy for Treatment of Benign Cicatricial Airway Stenosis

PubMed Central

Qiu, Xiao-Jian; Zhang, Jie; Wang, Ting; Pei, Ying-Hua; Xu, Min

2015-01-01

Background: Benign cicatricial airway stenosis (BCAS) is a life-threatening disease. While there are numerous therapies, all have their defects, and stenosis can easily become recurrent. This study aimed to investigate the efficacy and complications of nonstent combination interventional therapy (NSCIT) when used for the treatment of BCAS of different causes and types. Methods: This study enrolled a cohort of patients with BCAS resulting from tuberculosis, intubation, tracheotomy, and other origins. The patients were assigned to three groups determined by their type of stenosis: Web-like stenosis, granulation stenosis, and complex stenosis, and all patients received NSCIT. The efficacy and complications of treatment in each group of patients were observed. The Chi-square test, one-factor analysis of variance (ANOVA), and the paired t-test were used to analyze different parameters. Results: The 10 patients with web-like stenosis and six patients with granulation stenosis exhibited durable remission rates of 100%. Among 41 patients with complex stenosis, 36 cases (88%) experienced remission and 29 cases (71%) experienced durable remission. When five patients with airway collapse were eliminated from the analysis, the overall remission rate was 97%. The average treatment durations for patients with web-like stenosis, granulation stenosis, and complex stenosis were 101, 21, and 110 days, respectively, and the average number of treatments was five, two, and five, respectively. Conclusions: NSCIT demonstrated good therapeutic efficacy and was associated with few complications. However, this approach was ineffective for treating patients with airway collapse or malacia. PMID:26265607

Nonstent Combination Interventional Therapy for Treatment of Benign Cicatricial Airway Stenosis.

PubMed

Qiu, Xiao-Jian; Zhang, Jie; Wang, Ting; Pei, Ying-Hua; Xu, Min

2015-08-20

Benign cicatricial airway stenosis (BCAS) is a life-threatening disease. While there are numerous therapies, all have their defects, and stenosis can easily become recurrent. This study aimed to investigate the efficacy and complications of nonstent combination interventional therapy (NSCIT) when used for the treatment of BCAS of different causes and types. This study enrolled a cohort of patients with BCAS resulting from tuberculosis, intubation, tracheotomy, and other origins. The patients were assigned to three groups determined by their type of stenosis: Web-like stenosis, granulation stenosis, and complex stenosis, and all patients received NSCIT. The efficacy and complications of treatment in each group of patients were observed. The Chi-square test, one-factor analysis of variance (ANOVA), and the paired t -test were used to analyze different parameters. The 10 patients with web-like stenosis and six patients with granulation stenosis exhibited durable remission rates of 100%. Among 41 patients with complex stenosis, 36 cases (88%) experienced remission and 29 cases (71%) experienced durable remission. When five patients with airway collapse were eliminated from the analysis, the overall remission rate was 97%. The average treatment durations for patients with web-like stenosis, granulation stenosis, and complex stenosis were 101, 21, and 110 days, respectively, and the average number of treatments was five, two, and five, respectively. NSCIT demonstrated good therapeutic efficacy and was associated with few complications. However, this approach was ineffective for treating patients with airway collapse or malacia.

Multiple roles of mobile active center loops in the E1 component of the Escherichia coli pyruvate dehydrogenase complex - Linkage of protein dynamics to catalysis

PubMed Central

Jordan, Frank; Arjunan, Palaniappa; Kale, Sachin; Nemeria, Natalia S.; Furey, William

2009-01-01

The region encompassing residues 401–413 on the E1 component of the pyruvate dehydrogenase multienzyme complex from Escherichia coli comprises a loop (the inner loop) which was not seen in the X-ray structure in the presence of thiamin diphosphate, the required cofactor for the enzyme. This loop is seen in the presence of a stable analogue of the pre-decarboxylation intermediate, the covalent adduct between the substrate analogue methyl acetylphosphonate and thiamin diphosphate, C2α-phosphonolactylthiamin diphosphate. It has been shown that the residue H407 and several other residues on this loop are required to reduce the mobility of the loop so electron density corresponding to it can be seen once the pre-decarboxylation intermediate is formed. Concomitantly, the loop encompassing residues 541–557 (the outer loop) appears to work in tandem with the inner loop and there is a hydrogen bond between the two loops ensuring their correlated motion. The inner loop was shown to: a) sequester the active center from carboligase side reactions; b) assist the interaction between the E1 and the E2 components, thereby affecting the overall reaction rate of the entire multienzyme complex; c) control substrate access to the active center. Using viscosity effects on kinetics it was shown that formation of the pre-decarboxylation intermediate is specifically affected by loop movement. A cysteine-less variant was created for the E1 component, onto which cysteines were substituted at selected loop positions. Introducing an electron spin resonance spin label and an 19F NMR label onto these engineered cysteines, the loop mobility was examined: a) both methods suggested that in the absence of ligand, the loop exists in two conformations; b) line-shape analysis of the NMR signal at different temperatures, enabled estimation of the rate constant for loop movement, and this rate constant was found to be of the same order of magnitude as the turnover number for the enzyme under the same conditions. Furthermore, this analysis gave important insights into rate-limiting thermal loop dynamics. Overall, the results suggest that the dynamic properties correlate with catalytic events on the E1 component of the pyruvate dehydrogenase complex. PMID:20160956

SU-E-T-418: Explore the Sensitive of the Planar Quality Assurance to the MLC Error with Different Beam Complexity in Intensity-Modulate Radiation Therapy

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

Wang, J; Peng, J; Xie, J

2015-06-15

Purpose: The purpose of this study is to investigate the sensitivity of the planar quality assurance to MLC errors with different beam complexities in intensity-modulate radiation therapy. Methods: sixteen patients’ planar quality assurance (QA) plans in our institution were enrolled in this study, including 10 dynamic MLC (DMLC) IMRT plans measured by Portal Dosimetry and 6 static MLC (SMLC) IMRT plans measured by Mapcheck. The gamma pass rate was calculated using vender’s software. The field numbers were 74 and 40 for DMLC and SMLC, respectively. A random error was generated and introduced to these fields. The modified gamma pass ratemore » was calculated by comparing the original measured fluence and modified fields’ fluence. A decreasing gamma pass rate was acquired using the original gamma pass rate minus the modified gamma pass rate. Eight complexity scores were calculated in MATLAB based on the fluence and MLC sequence of these fields. The complexity scores include fractal dimension, monitor unit of field, modulation index, fluence map complexity, weighted average of field area, weighted average of field perimeter, and small aperture ratio ( <5cm{sup 2} and <50cm{sup 2}). The Spearman’s rank correlation coefficient was implemented to analyze the correlation between these scores and decreasing gamma rate. Results: The relation between the decreasing gamma pass rate and field complexity was insignificant for most complexity scores. The most significant complexity score was fluence map complexity for SMLC, which have ρ =0.4274 (p-value=0.0063). For DMLC, the most significant complex score was fractal dimension, which have ρ=−0.3068 (p-value=0.0081). Conclusions: According to the primarily Result of this study, the sensitivity gamma pass rate was not strongly relate to the field complexity.« less

Loop Analysis of Causal Feedback in Epidemiology: An Illustration Relating To Urban Neighborhoods and Resident Depressive Experiences

PubMed Central

2008-01-01

The causal feedback implied by urban neighborhood conditions that shape human health experiences, that in turn shape neighborhood conditions through a complex causal web, raises a challenge for traditional epidemiological causal analyses. This article introduces the loop analysis method, and builds off of a core loop model linking neighborhood property vacancy rate, resident depressive symptoms, rate of neighborhood death, and rate of neighborhood exit in a feedback network. I justify and apply loop analysis to the specific example of depressive symptoms and abandoned urban residential property to show how inquiries into the behavior of causal systems can answer different kinds of hypotheses, and thereby compliment those of causal modeling using statistical models. Neighborhood physical conditions that are only indirectly influenced by depressive symptoms may nevertheless manifest in the mental health experiences of their residents; conversely, neighborhood physical conditions may be a significant mental health risk for the population of neighborhood residents. I find that participatory greenspace programs are likely to produce adaptive responses in depressive symptoms and different neighborhood conditions, which are different in character to non-participatory greenspace interventions. PMID:17706851

Ethanol production improvement driven by genome-scale metabolic modeling and sensitivity analysis in Scheffersomyces stipitis

PubMed Central

2017-01-01

The yeast Scheffersomyces stipitis naturally produces ethanol from xylose, however reaching high ethanol yields is strongly dependent on aeration conditions. It has been reported that changes in the availability of NAD(H/+) cofactors can improve fermentation in some microorganisms. In this work genome-scale metabolic modeling and phenotypic phase plane analysis were used to characterize metabolic response on a range of uptake rates. Sensitivity analysis was used to assess the effect of ARC on ethanol production indicating that modifying ARC by inhibiting the respiratory chain ethanol production can be improved. It was shown experimentally in batch culture using Rotenone as an inhibitor of the mitochondrial NADH dehydrogenase complex I (CINADH), increasing ethanol yield by 18%. Furthermore, trajectories for uptakes rates, specific productivity and specific growth rate were determined by modeling the batch culture, to calculate ARC associated to the addition of CINADH inhibitor. Results showed that the increment in ethanol production via respiratory inhibition is due to excess in ARC, which generates an increase in ethanol production. Thus ethanol production improvement could be predicted by a change in ARC. PMID:28658270

Ethanol production improvement driven by genome-scale metabolic modeling and sensitivity analysis in Scheffersomyces stipitis.

PubMed

Acevedo, Alejandro; Conejeros, Raúl; Aroca, Germán

2017-01-01

The yeast Scheffersomyces stipitis naturally produces ethanol from xylose, however reaching high ethanol yields is strongly dependent on aeration conditions. It has been reported that changes in the availability of NAD(H/+) cofactors can improve fermentation in some microorganisms. In this work genome-scale metabolic modeling and phenotypic phase plane analysis were used to characterize metabolic response on a range of uptake rates. Sensitivity analysis was used to assess the effect of ARC on ethanol production indicating that modifying ARC by inhibiting the respiratory chain ethanol production can be improved. It was shown experimentally in batch culture using Rotenone as an inhibitor of the mitochondrial NADH dehydrogenase complex I (CINADH), increasing ethanol yield by 18%. Furthermore, trajectories for uptakes rates, specific productivity and specific growth rate were determined by modeling the batch culture, to calculate ARC associated to the addition of CINADH inhibitor. Results showed that the increment in ethanol production via respiratory inhibition is due to excess in ARC, which generates an increase in ethanol production. Thus ethanol production improvement could be predicted by a change in ARC.

Single-cell computational analysis of light harvesting in a flat-panel photo-bioreactor.

PubMed

Loomba, Varun; Huber, Gregor; von Lieres, Eric

2018-01-01

Flat-panel photo-bioreactors (PBRs) are customarily applied for investigating growth of microalgae. Optimal design and operation of such reactors is still a challenge due to complex non-linear combinations of various impact factors, particularly hydrodynamics, light irradiation, and cell metabolism. A detailed analysis of single-cell light reception can lead to novel insights into the complex interactions of light exposure and algae movement in the reactor. The combined impacts of hydrodynamics and light irradiation on algae cultivation in a flat-panel PBR were studied by tracing the light exposure of individual cells over time. Hydrodynamics and turbulent mixing in this air-sparged bioreactor were simulated using the Eulerian approach for the liquid phase and a slip model for the gas phase velocity profiles. The liquid velocity was then used for tracing single cells and their light exposure, using light intensity profiles obtained from solving the radiative transfer equation at different wavelengths. The residence times of algae cells in defined dark and light zones of the PBR were statistically analyzed for different algal concentrations and sparging rates. The results indicate poor mixing caused by the reactor design which can be only partially improved by increased sparging rates. The results provide important information for optimizing algal biomass productivity by improving bioreactor design and operation and can further be utilized for an in-depth analysis of algal growth by using advanced models of cell metabolism.

Factors Influencing Parents' Preferences and Parents' Perceptions of Child Preferences of Picturebooks

PubMed Central

Wagner, Laura

2017-01-01

This study examined factors influencing parents' preferences and their perceptions of their children's preferences for picturebooks. First, a content analysis was conducted on a set of picturebooks (N = 87) drawn from the sample described in Wagner (2013); Then, parents (N = 149) rated the books and several content properties were examined for their ability to predict parents' preferences and their perception of their children's preferences. The initial content analysis found correlated clusters of disparate measures of complexity (linguistic, cognitive, narrative) and identified a distinctive sub-genre of modern books featuring female protagonists. The experimental preference analysis found that parents' own preferences were most influenced by the books' age and status; parents' perceptions of their children's preferences were influenced by gender, with parents perceiving their sons (but not daughters) as dis-preferring books with female protagnoists. In addition, influences of the child's reading ability and the linguistic complexity of the book on preferences suggested a sensitivity to the cultural practice of joint book-reading. PMID:28919869

Electrostatic rate enhancement and transient complex of protein-protein association.

PubMed

Alsallaq, Ramzi; Zhou, Huan-Xiang

2008-04-01

The association of two proteins is bounded by the rate at which they, via diffusion, find each other while in appropriate relative orientations. Orientational constraints restrict this rate to approximately 10(5)-10(6) M(-1) s(-1). Proteins with higher association rates generally have complementary electrostatic surfaces; proteins with lower association rates generally are slowed down by conformational changes upon complex formation. Previous studies (Zhou, Biophys J 1997;73:2441-2445) have shown that electrostatic enhancement of the diffusion-limited association rate can be accurately modeled by $k_{\\bf D}$ = $k_{D}0\\ {exp} ( - \\langle U_{el} \\rangle;{\\star}/k_{B} T),$ where k(D) and k(D0) are the rates in the presence and absence of electrostatic interactions, respectively, U(el) is the average electrostatic interaction energy in a "transient-complex" ensemble, and k(B)T is the thermal energy. The transient-complex ensemble separates the bound state from the unbound state. Predictions of the transient-complex theory on four protein complexes were found to agree well with the experiment when the electrostatic interaction energy was calculated with the linearized Poisson-Boltzmann (PB) equation (Alsallaq and Zhou, Structure 2007;15:215-224). Here we show that the agreement is further improved when the nonlinear PB equation is used. These predictions are obtained with the dielectric boundary defined as the protein van der Waals surface. When the dielectric boundary is instead specified as the molecular surface, electrostatic interactions in the transient complex become repulsive and are thus predicted to retard association. Together these results demonstrate that the transient-complex theory is predictive of electrostatic rate enhancement and can help parameterize PB calculations. (c) 2007 Wiley-Liss, Inc.

Diagnosis of complex acid-base disorders: physician performance versus the microcomputer.

PubMed

Schreck, D M; Zacharias, D; Grunau, C F

1986-02-01

Patients with acid-base disturbances that are often complex frequently present to the emergency department. The sometimes hectic nature of the ED can preclude the appropriate quantitative analysis required by these disorders, especially when mixed disturbances are present. A computer program using generally accepted acid-base and electrolyte formulae was developed for use on the Apple II+ or IBM-PC microcomputer. Each of a series of 35 acid-base disturbances incorporating single, double, and triple disorders was correctly identified by the computer in less than 45 seconds. Problem sets based on the same 35 disturbances were presented to 21 physician-subjects at various levels of training from the emergency medicine, internal medicine, pediatrics, surgery, and family practice specialties. Although the physicians were given unlimited time and the necessary formulae to reach a diagnosis, they were requested to perform their analyses in the same fashion used in the ED. Although times varied widely, no physician spent more than five minutes on any problem. The physician correct response rates were 86%, 49%, and 17% for single, double, and triple disorders, respectively. The primary disorder correct response rate was 89% for double disorders and 94% for triple disorders. The primary and secondary disorder correct response rate was 58% for triple disorders. The data suggest that the microcomputer may be beneficial in the rapid assessment of complex disorders.

Spatial and temporal variability in sedimentation rates associated with cutoff channel infill deposits: Ain River, France

USGS Publications Warehouse

Piégay, H.; Hupp, C.R.; Citterio, A.; Dufour, S.; Moulin, B.; Walling, D.E.

2008-01-01

Floodplain development is associated with lateral accretion along stable channel geometry. Along shifting rivers, the floodplain sedimentation is more complex because of changes in channel position but also cutoff channel presence, which exhibit specific overflow patterns. In this contribution, the spatial and temporal variability of sedimentation rates in cutoff channel infill deposits is related to channel changes of a shifting gravel bed river (Ain River, France). The sedimentation rates estimated from dendrogeomorphic analysis are compared between and within 14 cutoff channel infills. Detailed analyses along a single channel infill are performed to assess changes in the sedimentation rates through time by analyzing activity profiles of the fallout radionuclides 137Cs and unsupported 210Pb. Sedimentation rates are also compared within the channel infills with rates in other plots located in the adjacent floodplain. Sedimentation rates range between 0.65 and 2.4 cm a−1 over a period of 10 to 40 years. The data provide additional information on the role of distance from the bank, overbank flow frequency, and channel geometry in controlling the sedimentation rate. Channel infills, lower than adjacent floodplains, exhibit higher sedimentation rates and convey overbank sediment farther away within the floodplain. Additionally, channel degradation, aggradation, and bank erosion, which reduce or increase the distance between the main channel and the cutoff channel aquatic zone, affect local overbank flow magnitude and frequency and therefore sedimentation rates, thereby creating a complex mosaic of sedimentation zones within the floodplain and along the cutoff channel infills. Last, the dendrogeomorphic and 137Cs approaches are cross validated for estimating the sedimentation rate within a channel infill.

Fiber estimation and tractography in diffusion MRI: Development of simulated brain images and comparison of multi-fiber analysis methods at clinical b-values

PubMed Central

Wilkins, Bryce; Lee, Namgyun; Gajawelli, Niharika; Law, Meng; Leporé, Natasha

2015-01-01

Advances in diffusion-weighted magnetic resonance imaging (DW-MRI) have led to many alternative diffusion sampling strategies and analysis methodologies. A common objective among methods is estimation of white matter fiber orientations within each voxel, as doing so permits in-vivo fiber-tracking and the ability to study brain connectivity and networks. Knowledge of how DW-MRI sampling schemes affect fiber estimation accuracy, and consequently tractography and the ability to recover complex white-matter pathways, as well as differences between results due to choice of analysis method and which method(s) perform optimally for specific data sets, all remain important problems, especially as tractography-based studies become common. In this work we begin to address these concerns by developing sets of simulated diffusion-weighted brain images which we then use to quantitatively evaluate the performance of six DW-MRI analysis methods in terms of estimated fiber orientation accuracy, false-positive (spurious) and false-negative (missing) fiber rates, and fiber-tracking. The analysis methods studied are: 1) a two-compartment “ball and stick” model (BSM) (Behrens et al., 2003); 2) a non-negativity constrained spherical deconvolution (CSD) approach (Tournier et al., 2007); 3) analytical q-ball imaging (QBI) (Descoteaux et al., 2007); 4) q-ball imaging with Funk-Radon and Cosine Transform (FRACT) (Haldar and Leahy, 2013); 5) q-ball imaging within constant solid angle (CSA) (Aganj et al., 2010); and 6) a generalized Fourier transform approach known as generalized q-sampling imaging (GQI) (Yeh et al., 2010). We investigate these methods using 20, 30, 40, 60, 90 and 120 evenly distributed q-space samples of a single shell, and focus on a signal-to-noise ratio (SNR = 18) and diffusion-weighting (b = 1000 s/mm2) common to clinical studies. We found the BSM and CSD methods consistently yielded the least fiber orientation error and simultaneously greatest detection rate of fibers. Fiber detection rate was found to be the most distinguishing characteristic between the methods, and a significant factor for complete recovery of tractography through complex white-matter pathways. For example, while all methods recovered similar tractography of prominent white matter pathways of limited fiber crossing, CSD (which had the highest fiber detection rate, especially for voxels containing three fibers) recovered the greatest number of fibers and largest fraction of correct tractography for a complex three-fiber crossing region. The synthetic data sets, ground-truth, and tools for quantitative evaluation are publically available on the NITRC website as the project “Simulated DW-MRI Brain Data Sets for Quantitative Evaluation of Estimated Fiber Orientations” at http://www.nitrc.org/projects/sim_dwi_brain PMID:25555998

Fiber estimation and tractography in diffusion MRI: development of simulated brain images and comparison of multi-fiber analysis methods at clinical b-values.

PubMed

Wilkins, Bryce; Lee, Namgyun; Gajawelli, Niharika; Law, Meng; Leporé, Natasha

2015-04-01

Advances in diffusion-weighted magnetic resonance imaging (DW-MRI) have led to many alternative diffusion sampling strategies and analysis methodologies. A common objective among methods is estimation of white matter fiber orientations within each voxel, as doing so permits in-vivo fiber-tracking and the ability to study brain connectivity and networks. Knowledge of how DW-MRI sampling schemes affect fiber estimation accuracy, tractography and the ability to recover complex white-matter pathways, differences between results due to choice of analysis method, and which method(s) perform optimally for specific data sets, all remain important problems, especially as tractography-based studies become common. In this work, we begin to address these concerns by developing sets of simulated diffusion-weighted brain images which we then use to quantitatively evaluate the performance of six DW-MRI analysis methods in terms of estimated fiber orientation accuracy, false-positive (spurious) and false-negative (missing) fiber rates, and fiber-tracking. The analysis methods studied are: 1) a two-compartment "ball and stick" model (BSM) (Behrens et al., 2003); 2) a non-negativity constrained spherical deconvolution (CSD) approach (Tournier et al., 2007); 3) analytical q-ball imaging (QBI) (Descoteaux et al., 2007); 4) q-ball imaging with Funk-Radon and Cosine Transform (FRACT) (Haldar and Leahy, 2013); 5) q-ball imaging within constant solid angle (CSA) (Aganj et al., 2010); and 6) a generalized Fourier transform approach known as generalized q-sampling imaging (GQI) (Yeh et al., 2010). We investigate these methods using 20, 30, 40, 60, 90 and 120 evenly distributed q-space samples of a single shell, and focus on a signal-to-noise ratio (SNR = 18) and diffusion-weighting (b = 1000 s/mm(2)) common to clinical studies. We found that the BSM and CSD methods consistently yielded the least fiber orientation error and simultaneously greatest detection rate of fibers. Fiber detection rate was found to be the most distinguishing characteristic between the methods, and a significant factor for complete recovery of tractography through complex white-matter pathways. For example, while all methods recovered similar tractography of prominent white matter pathways of limited fiber crossing, CSD (which had the highest fiber detection rate, especially for voxels containing three fibers) recovered the greatest number of fibers and largest fraction of correct tractography for complex three-fiber crossing regions. The synthetic data sets, ground-truth, and tools for quantitative evaluation are publically available on the NITRC website as the project "Simulated DW-MRI Brain Data Sets for Quantitative Evaluation of Estimated Fiber Orientations" at http://www.nitrc.org/projects/sim_dwi_brain. Copyright © 2014 Elsevier Inc. All rights reserved.

Processing parameters associated with scale-up of balloon film production

NASA Technical Reports Server (NTRS)

Simpson, D. M.; Harrison, I. R.

1993-01-01

A method is set forth for assessing strain-rate profiles that can be used to develop a scale-up theory for blown-film extrusion. Strain rates are evaluated by placing four ink dots on the stalk of an extruded bubble to follow the displacements of the dots as a function of time. The instantaneous Hencky strain is obtained with the displacement data and plotted for analysis. Specific attention is given to potential sources of error in the distance measurements and corrections for these complex bubble geometries. The method is shown to be effective for deriving strain-rate data related to different processing parameters for the production of balloon film. The strain rates can be compared to frostline height, blow-up ratio, and take-up ratio to optimize these processing variables.

Multiperspective analysis of workforce challenges and their effects on consumer and family quality of life.

PubMed

Larson, Sheryl A; Hewitt, Amy S; Lakin, K Charlie

2004-11-01

The impacts of direct support professional turnover, wages, and vacancy rates as reported in interviews with 372 adult service recipients and 20 county managers and surveys of 183 families, 520 service coordinators, 228 direct support professionals, and 184 residential and 82 vocational managers were examined. Direct support professional turnover, wages, and vacancy rates were reported to be barriers to high quality supports, serving people waiting for services, and providing in-home or respite services. Higher direct support professional turnover was associated with lower wages and supports in urban counties. Multivariate analyses of covariance revealed a complex pattern of significant associations between quality of life outcomes; level of mental retardation, medical status, site size (for vocational settings); and direct support professional vacancy rates, average wage, and turnover rates.

Linking clinician interaction and coordination to clinical performance in Patient-Aligned Care Teams.

PubMed

Hysong, Sylvia J; Thomas, Candice L; Spitzmüller, Christiane; Amspoker, Amber B; Woodard, LeChauncy; Modi, Varsha; Naik, Aanand D

2016-01-15

Team coordination within clinical care settings is a critical component of effective patient care. Less is known about the extent, effectiveness, and impact of coordination activities among professionals within VA Patient-Aligned Care Teams (PACTs). This study will address these gaps by describing the specific, fundamental tasks and practices involved in PACT coordination, their impact on performance measures, and the role of coordination task complexity. First, we will use a web-based survey of coordination practices among 1600 PACTs in the national VHA. Survey findings will characterize PACT coordination practices and assess their association with clinical performance measures. Functional job analysis, using 6-8 subject matter experts who are 3rd and 4th year residents in VA Primary Care rotations, will be utilized to identify the tasks involved in completing clinical performance measures to standard. From this, expert ratings of coordination complexity will be used to determine the level of coordinative complexity required for each of the clinical performance measures drawn from the VA External Peer Review Program (EPRP). For objective 3, data collected from the first two methods will evaluate the effect of clinical complexity on the relationships between measures of PACT coordination and their ratings on the clinical performance measures. Results from this study will support successful implementation of coordinated team-based work in clinical settings by providing knowledge regarding which aspects of care require the most complex levels of coordination and how specific coordination practices impact clinical performance.

AR(p) -based detrended fluctuation analysis

NASA Astrophysics Data System (ADS)

Alvarez-Ramirez, J.; Rodriguez, E.

2018-07-01

Autoregressive models are commonly used for modeling time-series from nature, economics and finance. This work explored simple autoregressive AR(p) models to remove long-term trends in detrended fluctuation analysis (DFA). Crude oil prices and bitcoin exchange rate were considered, with the former corresponding to a mature market and the latter to an emergent market. Results showed that AR(p) -based DFA performs similar to traditional DFA. However, the former DFA provides information on stability of long-term trends, which is valuable for understanding and quantifying the dynamics of complex time series from financial systems.

[Recurrence plot analysis of HRV for brain ischemia and asphyxia].

PubMed

Chen, Xiaoming; Qiu, Yihong; Zhu, Yisheng

2008-02-01

Heart rate variability (HRV) is the tiny variability existing in the cycles of the heart beats, which reflects the corresponding balance between sympathetic and vagus nerves. Since the nonlinear characteristic of HRV is confirmed, the Recurrence Plot method, a nonlinear dynamic analysis method based on the complexity, could be used to analyze HRV. The results showed the recurrence plot structures and some quantitative indices (L-Mean, L-Entr) during asphyxia insult vary significantly as compared to those in normal conditions, which offer a new method to monitor brain asphyxia injury.

Stage call: Cardiovascular reactivity to audition stress in musicians

PubMed Central

Chanwimalueang, Theerasak; Aufegger, Lisa; Adjei, Tricia; Wasley, David; Cruder, Cinzia; Mandic, Danilo P.

2017-01-01

Auditioning is at the very center of educational and professional life in music and is associated with significant psychophysical demands. Knowledge of how these demands affect cardiovascular responses to psychosocial pressure is essential for developing strategies to both manage stress and understand optimal performance states. To this end, we recorded the electrocardiograms (ECGs) of 16 musicians (11 violinists and 5 flutists) before and during performances in both low- and high-stress conditions: with no audience and in front of an audition panel, respectively. The analysis consisted of the detection of R-peaks in the ECGs to extract heart rate variability (HRV) from the notoriously noisy real-world ECGs. Our data analysis approach spanned both standard (temporal and spectral) and advanced (structural complexity) techniques. The complexity science approaches—namely, multiscale sample entropy and multiscale fuzzy entropy—indicated a statistically significant decrease in structural complexity in HRV from the low- to the high-stress condition and an increase in structural complexity from the pre-performance to performance period, thus confirming the complexity loss theory and a loss in degrees of freedom due to stress. Results from the spectral analyses also suggest that the stress responses in the female participants were more parasympathetically driven than those of the male participants. In conclusion, our findings suggest that interventions to manage stress are best targeted at the sensitive pre-performance period, before an audition begins. PMID:28437466

Mathematical morphology-based shape feature analysis for Chinese character recognition systems

NASA Astrophysics Data System (ADS)

Pai, Tun-Wen; Shyu, Keh-Hwa; Chen, Ling-Fan; Tai, Gwo-Chin

1995-04-01

This paper proposes an efficient technique of shape feature extraction based on the application of mathematical morphology theory. A new shape complexity index for preclassification of machine printed Chinese Character Recognition (CCR) is also proposed. For characters represented in different fonts/sizes or in a low resolution environment, a more stable local feature such as shape structure is preferred for character recognition. Morphological valley extraction filters are applied to extract the protrusive strokes from four sides of an input Chinese character. The number of extracted local strokes reflects the shape complexity of each side. These shape features of characters are encoded as corresponding shape complexity indices. Based on the shape complexity index, data base is able to be classified into 16 groups prior to recognition procedures. The performance of associating with shape feature analysis reclaims several characters from misrecognized character sets and results in an average of 3.3% improvement of recognition rate from an existing recognition system. In addition to enhance the recognition performance, the extracted stroke information can be further analyzed and classified its own stroke type. Therefore, the combination of extracted strokes from each side provides a means for data base clustering based on radical or subword components. It is one of the best solutions for recognizing high complexity characters such as Chinese characters which are divided into more than 200 different categories and consist more than 13,000 characters.

Minimal effects of latitude on present-day speciation rates in New World birds

PubMed Central

Rabosky, Daniel L.; Title, Pascal O.; Huang, Huateng

2015-01-01

The tropics contain far greater numbers of species than temperate regions, suggesting that rates of species formation might differ systematically between tropical and non-tropical areas. We tested this hypothesis by reconstructing the history of speciation in New World (NW) land birds using BAMM, a Bayesian framework for modelling complex evolutionary dynamics on phylogenetic trees. We estimated marginal distributions of present-day speciation rates for each of 2571 species of birds. The present-day rate of speciation varies approximately 30-fold across NW birds, but there is no difference in the rate distributions for tropical and temperate taxa. Using macroevolutionary cohort analysis, we demonstrate that clades with high tropical membership do not produce species more rapidly than temperate clades. For nearly any value of present-day speciation rate, there are far more species in the tropics than the temperate zone. Any effects of latitude on speciation rate are marginal in comparison to the dramatic variation in rates among clades. PMID:26019156

Coupled-cluster treatment of molecular strong-field ionization

NASA Astrophysics Data System (ADS)

Jagau, Thomas-C.

2018-05-01

Ionization rates and Stark shifts of H2, CO, O2, H2O, and CH4 in static electric fields have been computed with coupled-cluster methods in a basis set of atom-centered Gaussian functions with a complex-scaled exponent. Consideration of electron correlation is found to be of great importance even for a qualitatively correct description of the dependence of ionization rates and Stark shifts on the strength and orientation of the external field. The analysis of the second moments of the molecular charge distribution suggests a simple criterion for distinguishing tunnel and barrier suppression ionization in polyatomic molecules.

Electrostatic Rate Enhancement and Transient Complex of Protein-Protein Association

PubMed Central

Alsallaq, Ramzi; Zhou, Huan-Xiang

2012-01-01

The association of two proteins is bounded by the rate at which they, via diffusion, find each other while in appropriate relative orientations. Orientational constraints restrict this rate to ~105 – 106 M−1s−1. Proteins with higher association rates generally have complementary electrostatic surfaces; proteins with lower association rates generally are slowed down by conformational changes upon complex formation. Previous studies (Zhou, Biophys. J. 1997;73:2441–2445) have shown that electrostatic enhancement of the diffusion-limited association rate can be accurately modeled by kD = kD0 exp(−*/ kBT), where kD and kD0 are the rates in the presence and absence of electrostatic interactions, respectively, * is the average electrostatic interaction energy in a “transient-complex” ensemble, and kBT is thermal energy. The transient-complex ensemble separates the bound state from the unbound state. Predictions of the transient-complex theory on four protein complexes were found to agree well with experiment when the electrostatic interaction energy was calculated with the linearized Poisson-Boltzmann (PB) equation (Alsallaq and Zhou, Structure 2007, 15:215–224). Here we show that the agreement is further improved when the nonlinear PB equation is used. These predictions are obtained with the dielectric boundary defined as the protein van der Waals surface. When the dielectric boundary is instead specified as the molecular surface, electrostatic interactions in the transient complex become repulsive and are thus predicted to retard association. Together these results demonstrate that the transient-complex theory is predictive of electrostatic rate enhancement and can help parameterize PB calculations. PMID:17932929

The dependence of crowding on flanker complexity and target-flanker similarity

PubMed Central

Bernard, Jean-Baptiste; Chung, Susana T.L.

2013-01-01

We examined the effects of the spatial complexity of flankers and target-flanker similarity on the performance of identifying crowded letters. On each trial, observers identified the middle character of random strings of three characters (“trigrams”) briefly presented at 10° below fixation. We tested the 26 lowercase letters of the Times-Roman and Courier fonts, a set of 79 characters (letters and non-letters) of the Times-Roman font, and the uppercase letters of two highly complex ornamental fonts, Edwardian and Aristocrat. Spatial complexity of characters was quantified by the length of the morphological skeleton of each character, and target-flanker similarity was defined based on a psychometric similarity matrix. Our results showed that (1) letter identification error rate increases with flanker complexity up to a certain value, beyond which error rate becomes independent of flanker complexity; (2) the increase of error rate is slower for high-complexity target letters; (3) error rate increases with target-flanker similarity; and (4) mislocation error rate increases with target-flanker similarity. These findings, combined with the current understanding of the faulty feature integration account of crowding, provide some constraints of how the feature integration process could cause perceptual errors. PMID:21730225

Study on viscosity of conventional and polymer modified asphalt binders in steady and dynamic shear domain

NASA Astrophysics Data System (ADS)

Saboo, Nikhil; Singh, Bhupendra; Kumar, Praveen; Vikram, Durgesh

2018-02-01

This study focuses on evaluating the flow behavior of conventional and polymer modified asphalt binders in steady- and dynamic-shear domain, for a temperature range of 20-70 °C, using a Dynamic Shear Rheometer (DSR). Steady-shear viscosity and frequency sweep tests were carried out on two conventional (VG 10 and VG 30) and two polymer (SBS and EVA) modified asphalt binders. Applicability of the Cox-Merz principle was evaluated and complex viscosity master curves were analyzed at five different reference temperatures. Cross model was used to simulate the complex viscosity master curves at different temperatures. It was found that asphalt binders exhibited shear-thinning behavior at all the test temperatures. The critical shear rate increased with increase in temperature and was found to be lowest for plastomeric modified asphalt binder. The Cox-Merz principle was found to be valid in the zero-shear viscosity (ZSV) domain and deviated at higher frequency/shear rate for all the binders. Results from the study indicated that the ratio of ZSV can be successfully used as shift factors for construction of master curves at different reference temperatures. Cross model was found to be suitable in simulating the complex viscosity master curves at all the test temperatures. Analysis of model parameters indicated that a strong relationship exists between ZSV and the critical shear rate. ZSV and critical shear rate varied exponentially with temperature. This relationship was used to propose a simple equation for assessing the shift factors for construction of master curves.

Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

PubMed Central

Bogdanovich, Jose M.; Bozinovic, Francisco

2016-01-01

Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2), in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO2) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s), either monofractal or weak multifractal dynamics are observed depending on whether Ta < 15 °C or Ta > 15 °C respectively. For larger time scales, r(VO2) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system. PMID:27781179

Nonlinear temperature effects on multifractal complexity of metabolic rate of mice.

PubMed

Labra, Fabio A; Bogdanovich, Jose M; Bozinovic, Francisco

2016-01-01

Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r ( VO 2 ), in the laboratory mouse Mus musculus , assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO 2 ) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 10 2 s), either monofractal or weak multifractal dynamics are observed depending on whether T a < 15 °C or T a > 15 °C respectively. For larger time scales, r(VO 2 ) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ ( q ), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b . We also show that the long-range correlation structure of r(VO 2 ) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

SU-E-T-159: Evaluation of a Patient Specific QA Tool Based On TG119

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

Ashmeg, S; Zhang, Y; O'Daniel, J

2014-06-01

Purpose: To evaluate the accuracy of a 3D patient specific QA tool by analysis of the results produced from associated software in homogenous phantom and heterogonous patient CT. Methods: IMRT and VMAT plans of five test suites introduced by TG119 were created in ECLIPSE on a solid water phantom. The ten plans -of increasing complexity- were delivered to Delta4 to give a 3D measurement. The Delta4's “Anatomy” software uses the measured dose to back-calculate the energy fluence of the delivered beams, which is used for dose calculation in a patient CT using a pencilbeam algorithm. The effect of the modulatedmore » beams' complexity on the accuracy of the “Anatomy” calculation was evaluated. Both measured and Anatomy doses were compared to ECLIPSE calculation using 3% - 3mm gamma criteria.We also tested the effect of heterogeneity by analyzing the results of “Anatomy” calculation on a Brain VMAT and a 3D conformal lung cases. Results: In homogenous phantom, the gamma passing rates were found to be as low as 74.75% for a complex plan with high modulation. The mean passing rates were 91.47% ± 6.35% for “Anatomy” calculation and 99.46% ± 0.62% for Delta4 measurements.As for the heterogeneous cases, the rates were 96.54%±3.67% and 83.87%±9.42% for Brain VMAT and 3D lung respectively. This increased error in the lung case could be due to the use of the pencil beam algorithm as opposed to the AAA used by ECLIPSE.Also, gamma analysis showed high discrepancy along the beam edge in the “Anatomy” calculated results. This suggests a poor beam modeling in the penumbra region. Conclusion: The results show various sources of errors in “Anatomy” calculations. These include beam modeling in the penumbra region, complexity of a modulated beam (shown in homogenous phantom and brain cases) and dose calculation algorithms (3D conformal lung case)« less

Dramatic Influence of an Anionic Donor on the Oxygen-Atom Transfer Reactivity of a MnV–Oxo Complex

PubMed Central

Neu, Heather M; Quesne, Matthew G; Yang, Tzuhsiung; Prokop-Prigge, Katharine A; Lancaster, Kyle M; Donohoe, James; DeBeer, Serena; de Visser, Sam P; Goldberg, David P

2014-01-01

Addition of an anionic donor to an MnV(O) porphyrinoid complex causes a dramatic increase in 2-electron oxygen-atom-transfer (OAT) chemistry. The 6-coordinate [MnV(O)(TBP8Cz)(CN)]− was generated from addition of Bu4N+CN− to the 5-coordinate MnV(O) precursor. The cyanide-ligated complex was characterized for the first time by Mn K-edge X-ray absorption spectroscopy (XAS) and gives Mn–O=1.53 Å, Mn–CN=2.21 Å. In combination with computational studies these distances were shown to correlate with a singlet ground state. Reaction of the CN− complex with thioethers results in OAT to give the corresponding sulfoxide and a 2e−-reduced MnIII(CN)− complex. Kinetic measurements reveal a dramatic rate enhancement for OAT of approximately 24 000-fold versus the same reaction for the parent 5-coordinate complex. An Eyring analysis gives ΔH≠=14 kcal mol−1, ΔS≠=−10 cal mol−1 K−1. Computational studies fully support the structures, spin states, and relative reactivity of the 5- and 6-coordinate MnV(O) complexes. PMID:25256417

Effect of Simvastatin, Coenzyme Q10, Resveratrol, Acetylcysteine and Acetylcarnitine on Mitochondrial Respiration.

PubMed

Fišar, Z; Hroudová, J; Singh, N; Kopřivová, A; Macečková, D

2016-01-01

Some therapeutic and/or adverse effects of drugs may be related to their effects on mitochondrial function. The effects of simvastatin, resveratrol, coenzyme Q10, acetylcysteine, and acetylcarnitine on Complex I-, Complex II-, or Complex IV-linked respiratory rate were determined in isolated brain mitochondria. The protective effects of these biologically active compounds on the calcium-induced decrease of the respiratory rate were also studied. We observed a significant inhibitory effect of simvastatin on mitochondrial respiration (IC50 = 24.0 μM for Complex I-linked respiration, IC50 = 31.3 μM for Complex II-linked respiration, and IC50 = 42.9 μM for Complex IV-linked respiration); the inhibitory effect of resveratrol was found at very high concentrations (IC50 = 162 μM for Complex I-linked respiration, IC50 = 564 μM for Complex II-linked respiration, and IC50 = 1454 μM for Complex IV-linked respiration). Concentrations required for effective simvastatin- or resveratrol-induced inhibition of mitochondrial respiration were found much higher than concentrations achieved under standard dosing of these drugs. Acetylcysteine and acetylcarnitine did not affect the oxygen consumption rate of mitochondria. Coenzyme Q10 induced an increase of Complex I-linked respiration. The increase of free calcium ions induced partial inhibition of the Complex I+II-linked mitochondrial respiration, and all tested drugs counteracted this inhibition. None of the tested drugs showed mitochondrial toxicity (characterized by respiratory rate inhibition) at drug concentrations achieved at therapeutic drug intake. Resveratrol, simvastatin, and acetylcarnitine had the greatest neuroprotective potential (characterized by protective effects against calcium-induced reduction of the respiratory rate).

First integrative trend analysis for a great ape species in Borneo.

PubMed

Santika, Truly; Ancrenaz, Marc; Wilson, Kerrie A; Spehar, Stephanie; Abram, Nicola; Banes, Graham L; Campbell-Smith, Gail; Curran, Lisa; d'Arcy, Laura; Delgado, Roberto A; Erman, Andi; Goossens, Benoit; Hartanto, Herlina; Houghton, Max; Husson, Simon J; Kühl, Hjalmar S; Lackman, Isabelle; Leiman, Ashley; Llano Sanchez, Karmele; Makinuddin, Niel; Marshall, Andrew J; Meididit, Ari; Mengersen, Kerrie; Musnanda; Nardiyono; Nurcahyo, Anton; Odom, Kisar; Panda, Adventus; Prasetyo, Didik; Purnomo; Rafiastanto, Andjar; Raharjo, Slamet; Ratnasari, Dessy; Russon, Anne E; Santana, Adi H; Santoso, Eddy; Sapari, Iman; Sihite, Jamartin; Suyoko, Ahmat; Tjiu, Albertus; Utami-Atmoko, Sri Suci; van Schaik, Carel P; Voigt, Maria; Wells, Jessie; Wich, Serge A; Willems, Erik P; Meijaard, Erik

2017-07-07

For many threatened species the rate and drivers of population decline are difficult to assess accurately: species' surveys are typically restricted to small geographic areas, are conducted over short time periods, and employ a wide range of survey protocols. We addressed methodological challenges for assessing change in the abundance of an endangered species. We applied novel methods for integrating field and interview survey data for the critically endangered Bornean orangutan (Pongo pygmaeus), allowing a deeper understanding of the species' persistence through time. Our analysis revealed that Bornean orangutan populations have declined at a rate of 25% over the last 10 years. Survival rates of the species are lowest in areas with intermediate rainfall, where complex interrelations between soil fertility, agricultural productivity, and human settlement patterns influence persistence. These areas also have highest threats from human-wildlife conflict. Survival rates are further positively associated with forest extent, but are lower in areas where surrounding forest has been recently converted to industrial agriculture. Our study highlights the urgency of determining specific management interventions needed in different locations to counter the trend of decline and its associated drivers.

Molecular inclusion complex of curcumin-β-cyclodextrin nanoparticle to enhance curcumin skin permeability from hydrophilic matrix gel.

PubMed

Rachmawati, Heni; Edityaningrum, Citra Ariani; Mauludin, Rachmat

2013-12-01

Curcumin (CUR) has various pharmacological effects, but its extensive first-pass metabolism and short elimination half-life limit its bioavailability. Therefore, transdermal application has become a potential alternative to delivery CUR. To increase CUR solubility for the development of a transparent homogenous gel and also enhance the permeation rate of CUR into the skin, β-cyclodextrin-curcumin nanoparticle complex (BCD-CUR-N) was developed. CUR encapsulation efficiency was increased by raising the percentage of CUR to BCD up to 20%. The mean particle size of the best CUR loading formula was 156 nm. All evaluation data using infrared spectroscopy, Raman spectroscopy, powder X-ray diffractometry, differential thermal analysis and scanning electron microscopy confirmed the successful formation of the inclusion complex. BCD-CUR-N increased the CUR dissolution rate of 10-fold (p < 0.01). In addition, the improvement of CUR permeability acrossed skin model tissue was observed in gel containing the BCD-CUR-N and was about 1.8-fold when compared with the free CUR gel (p < 0.01). Overall, CUR in the form of the BCD-CUR-N improved the solubility further on the penetration of CUR.

The sh2-R allele of the maize shrunken-2 locus was caused by a complex chromosomal rearrangement.

PubMed

Kramer, Vance; Shaw, Janine R; Senior, M Lynn; Hannah, L Curtis

2015-03-01

The mutant that originally defined the shrunken - 2 locus of maize is shown here to be the product of a complex chromosomal rearrangement. The maize shrunken-2 gene (sh2) encodes the large subunit of the heterotetrameric enzyme, adenosine diphosphate glucose pyrophosphorylases and a rate-limiting enzyme in starch biosynthesis. The sh2 gene was defined approximately 72 years ago by the isolation of a loss-of-function allele conditioning a shrunken, but viable seed. In subsequent years, the realization that this allele, termed zsh2-R or sh2-Reference, causes an extremely high level of sucrose to accumulate in the developing seed led to a revolution in the sweet corn industry. Now, the vast majority of sweet corns grown throughout the world contain this mutant allele. Through initial Southern analysis followed by genomic sequencing, the work reported here shows that this allele arose through a complex set of events involving at least three breaks of chromosome 3 as well as an intra-chromosomal inversion. These findings provide an explanation for some previously reported, unexpected observations concerning rates of recombination within and between genes in this region.

Electron transfer reaction of oxo(salen)chromium(V) ion with anilines.

PubMed

Premsingh, Sundarsingh; Venkataramanan, Natarajan Sathiyamoorthy; Rajagopal, Seenivasan; Mirza, Shama P; Vairamani, Mariappanadar; Rao, P Sambasiva; Velavan, K

2004-09-06

The kinetics of oxidation of 16 meta-, ortho-, and para-substituted anilines with nine oxo(salen)chromium(V) ions have been studied by spectrophotometric, ESIMS, and EPR techniques. During the course of the reaction, two new peaks with lambda(max) at 470 and 730 nm appear in the absorption spectrum, and these peaks are due to the formation of emeraldine forms of oligomers of aniline supported by the ESIMS peaks with m/z values 274 and 365 (for the trimer and tetramer of aniline). The rate of the reaction is highly sensitive to the change of substituents in the aryl moiety of aniline and in the salen ligand of chromium(V) complexes. Application of the Hammett equation to analyze kinetic data yields a rho value of -3.8 for the substituent variation in aniline and +2.2 for the substituent variation in the salen ligand of the metal complex. On the basis of the spectral, kinetic, and product analysis studies, a mechanism involving an electron transfer from the nitrogen of aniline to the metal complex in the rate controlling step has been proposed. The Marcus equation has been successfully applied to this system, and the calculated values are compliant with the measured values.

Characterization of brightness and stoichiometry of bright particles by flow-fluorescence fluctuation spectroscopy.

PubMed

Johnson, Jolene; Chen, Yan; Mueller, Joachim D

2010-11-03

Characterization of bright particles at low concentrations by fluorescence fluctuation spectroscopy (FFS) is challenging, because the event rate of particle detection is low and fluorescence background contributes significantly to the measured signal. It is straightforward to increase the event rate by flow, but the high background continues to be problematic for fluorescence correlation spectroscopy. Here, we characterize the use of photon-counting histogram analysis in the presence of flow. We demonstrate that a photon-counting histogram efficiently separates the particle signal from the background and faithfully determines the brightness and concentration of particles independent of flow speed, as long as undersampling is avoided. Brightness provides a measure of the number of fluorescently labeled proteins within a complex and has been used to determine stoichiometry of protein complexes in vivo and in vitro. We apply flow-FFS to determine the stoichiometry of the group specific antigen protein within viral-like particles of the human immunodeficiency virus type-1 from the brightness. Our results demonstrate that flow-FFS is a sensitive method for the characterization of complex macromolecular particles at low concentrations. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Quantitative determination of conformational, dynamic, and kinetic parameters of a ligand-protein/DNA complex from a complete relaxation and conformational exchange matrix analysis of intermolecular transferred NOESY.

PubMed

Moseley, H N; Lee, W; Arrowsmith, C H; Krishna, N R

1997-05-06

We report a quantitative analysis of the 13C-edited intermolecular transferred NOESY (inter-TrNOESY) spectrum of the trp-repressor/operator complex (trp-rep/op) with [ul-13C/15N]-L-tryptophan corepressor using a computer program implementing complete relaxation and conformational exchange matrix (CORCEMA) methodology [Moseley et al. (1995) J. Magn. Reson. 108B, 243-261]. Using complete mixing time curves of three inter-TrNOESY peaks between the tryptophan and the Trp-rep/op, this self-consistent analysis determined the correlation time of the bound species (tauB = 13.5 ns) and the exchange off-rate (k(off) = 3.6 s(-1)) of the corepressor. In addition, the analysis estimated the correlation time of the free species (tauF approximately 0.15 ns). Also, we demonstrate the sensitivity of these inter-TrNOESY peaks to several factors including the k(off) and orientation of the tryptophan corepressor within the binding site. The analysis indicates that the crystal structure orientation for the corepressor is compatible with the solution NMR data.

Commercial Discount Rate Estimation for Efficiency Standards Analysis

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

Fujita, K. Sydny

2016-04-13

Underlying each of the Department of Energy's (DOE's) federal appliance and equipment standards are a set of complex analyses of the projected costs and benefits of regulation. Any new or amended standard must be designed to achieve significant additional energy conservation, provided that it is technologically feasible and economically justified (42 U.S.C. 6295(o)(2)(A)). A proposed standard is considered economically justified when its benefits exceed its burdens, as represented by the projected net present value of costs and benefits. DOE performs multiple analyses to evaluate the balance of costs and benefits of commercial appliance and equipment e efficiency standards, at themore » national and individual building or business level, each framed to capture different nuances of the complex impact of standards on the commercial end user population. The Life-Cycle Cost (LCC) analysis models the combined impact of appliance first cost and operating cost changes on a representative commercial building sample in order to identify the fraction of customers achieving LCC savings or incurring net cost at the considered efficiency levels.1 Thus, the choice of commercial discount rate value(s) used to calculate the present value of energy cost savings within the Life-Cycle Cost model implicitly plays a key role in estimating the economic impact of potential standard levels.2 This report is intended to provide a more in-depth discussion of the commercial discount rate estimation process than can be readily included in standard rulemaking Technical Support Documents (TSDs).« less

Automatic classification for mammogram backgrounds based on bi-rads complexity definition and on a multi content analysis framework

NASA Astrophysics Data System (ADS)

Wu, Jie; Besnehard, Quentin; Marchessoux, Cédric

2011-03-01

Clinical studies for the validation of new medical imaging devices require hundreds of images. An important step in creating and tuning the study protocol is the classification of images into "difficult" and "easy" cases. This consists of classifying the image based on features like the complexity of the background, the visibility of the disease (lesions). Therefore, an automatic medical background classification tool for mammograms would help for such clinical studies. This classification tool is based on a multi-content analysis framework (MCA) which was firstly developed to recognize image content of computer screen shots. With the implementation of new texture features and a defined breast density scale, the MCA framework is able to automatically classify digital mammograms with a satisfying accuracy. BI-RADS (Breast Imaging Reporting Data System) density scale is used for grouping the mammograms, which standardizes the mammography reporting terminology and assessment and recommendation categories. Selected features are input into a decision tree classification scheme in MCA framework, which is the so called "weak classifier" (any classifier with a global error rate below 50%). With the AdaBoost iteration algorithm, these "weak classifiers" are combined into a "strong classifier" (a classifier with a low global error rate) for classifying one category. The results of classification for one "strong classifier" show the good accuracy with the high true positive rates. For the four categories the results are: TP=90.38%, TN=67.88%, FP=32.12% and FN =9.62%.

Revitalizing Complex Analysis: A Transition-to-Proof Course Centered on Complex Topics

ERIC Educational Resources Information Center

Sachs, Robert

2017-01-01

A new transition course centered on complex topics would help in revitalizing complex analysis in two ways: first, provide early exposure to complex functions, sparking greater interest in the complex analysis course; second, create extra time in the complex analysis course by eliminating the "complex precalculus" part of the course. In…

A finite element framework for multiscale/multiphysics analysis of structures with complex microstructures

NASA Astrophysics Data System (ADS)

Varghese, Julian

This research work has contributed in various ways to help develop a better understanding of textile composites and materials with complex microstructures in general. An instrumental part of this work was the development of an object-oriented framework that made it convenient to perform multiscale/multiphysics analyses of advanced materials with complex microstructures such as textile composites. In addition to the studies conducted in this work, this framework lays the groundwork for continued research of these materials. This framework enabled a detailed multiscale stress analysis of a woven DCB specimen that revealed the effect of the complex microstructure on the stress and strain energy release rate distribution along the crack front. In addition to implementing an oxidation model, the framework was also used to implement strategies that expedited the simulation of oxidation in textile composites so that it would take only a few hours. The simulation showed that the tow architecture played a significant role in the oxidation behavior in textile composites. Finally, a coupled diffusion/oxidation and damage progression analysis was implemented that was used to study the mechanical behavior of textile composites under mechanical loading as well as oxidation. A parametric study was performed to determine the effect of material properties and the number of plies in the laminate on its mechanical behavior. The analyses indicated a significant effect of the tow architecture and other parameters on the damage progression in the laminates.

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction.

PubMed

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

2017-01-01

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl 2 ]·2H 2 O (1) , [Co(L)Cl 2 (H 2 O) 2 ] (2) and [Ni(L)Cl 2 (H 2 O) 2 ] (3) , having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1 . The esterification of butanol gave butyl acetate with 100% selectivity.

Exploring stability of entropy analysis for signal with different trends

NASA Astrophysics Data System (ADS)

Zhang, Yin; Li, Jin; Wang, Jun

2017-03-01

Considering the effects of environment disturbances and instrument systems, the actual detecting signals always are carrying different trends, which result in that it is difficult to accurately catch signals complexity. So choosing steady and effective analysis methods is very important. In this paper, we applied entropy measures-the base-scale entropy and approximate entropy to analyze signal complexity, and studied the effect of trends on the ideal signal and the heart rate variability (HRV) signals, that is, linear, periodic, and power-law trends which are likely to occur in actual signals. The results show that approximate entropy is unsteady when we embed different trends into the signals, so it is not suitable to analyze signal with trends. However, the base-scale entropy has preferable stability and accuracy for signal with different trends. So the base-scale entropy is an effective method to analyze the actual signals.

Angular Rate Sensing with GyroWheel Using Genetic Algorithm Optimized Neural Networks.

PubMed

Zhao, Yuyu; Zhao, Hui; Huo, Xin; Yao, Yu

2017-07-22

GyroWheel is an integrated device that can provide three-axis control torques and two-axis angular rate sensing for small spacecrafts. Large tilt angle of its rotor and de-tuned spin rate lead to a complex and non-linear dynamics as well as difficulties in measuring angular rates. In this paper, the problem of angular rate sensing with the GyroWheel is investigated. Firstly, a simplified rate sensing equation is introduced, and the error characteristics of the method are analyzed. According to the analysis results, a rate sensing principle based on torque balance theory is developed, and a practical way to estimate the angular rates within the whole operating range of GyroWheel is provided by using explicit genetic algorithm optimized neural networks. The angular rates can be determined by the measurable values of the GyroWheel (including tilt angles, spin rate and torque coil currents), the weights and the biases of the neural networks. Finally, the simulation results are presented to illustrate the effectiveness of the proposed angular rate sensing method with GyroWheel.

Sex differences in the fetal heart rate variability indices of twins.

PubMed

Tendais, Iva; Figueiredo, Bárbara; Gonçalves, Hernâni; Bernardes, João; Ayres-de-Campos, Diogo; Montenegro, Nuno

2015-03-01

To evaluate the differences in linear and complex heart rate dynamics in twin pairs according to fetal sex combination [male-female (MF), male-male (MM), and female-female (FF)]. Fourteen twin pairs (6 MF, 3 MM, and 5 FF) were monitored between 31 and 36.4 weeks of gestation. Twenty-six fetal heart rate (FHR) recordings of both twins were simultaneously acquired and analyzed with a system for computerized analysis of cardiotocograms. Linear and nonlinear FHR indices were calculated. Overall, MM twins presented higher intrapair average in linear indices than the other pairs, whereas FF twins showed higher sympathetic-vagal balance. MF twins exhibited higher intrapair average in entropy indices and MM twins presented lower entropy values than FF twins considering the (automatically selected) threshold rLu. MM twin pairs showed higher intrapair differences in linear heart rate indices than MF and FF twins, whereas FF twins exhibited lower intrapair differences in entropy indices. The results of this exploratory study suggest that twins have sex-specific differences in linear and nonlinear indices of FHR. MM twins expressed signs of a more active autonomic nervous system and MF twins showed the most active complexity control system. These results suggest that fetal sex combination should be taken into consideration when performing detailed evaluation of the FHR in twins.

Fluctuations in Wikipedia access-rate and edit-event data

NASA Astrophysics Data System (ADS)

Kämpf, Mirko; Tismer, Sebastian; Kantelhardt, Jan W.; Muchnik, Lev

2012-12-01

Internet-based social networks often reflect extreme events in nature and society by drastic increases in user activity. We study and compare the dynamics of the two major complex processes necessary for information spread via the online encyclopedia ‘Wikipedia’, i.e., article editing (information upload) and article access (information viewing) based on article edit-event time series and (hourly) user access-rate time series for all articles. Daily and weekly activity patterns occur in addition to fluctuations and bursting activity. The bursts (i.e., significant increases in activity for an extended period of time) are characterized by a power-law distribution of durations of increases and decreases. For describing the recurrence and clustering of bursts we investigate the statistics of the return intervals between them. We find stretched exponential distributions of return intervals in access-rate time series, while edit-event time series yield simple exponential distributions. To characterize the fluctuation behavior we apply detrended fluctuation analysis (DFA), finding that most article access-rate time series are characterized by strong long-term correlations with fluctuation exponents α≈0.9. The results indicate significant differences in the dynamics of information upload and access and help in understanding the complex process of collecting, processing, validating, and distributing information in self-organized social networks.

Use of an uncertainty analysis for genome-scale models as a prediction tool for microbial growth processes in subsurface environments.

PubMed

Klier, Christine

2012-03-06

The integration of genome-scale, constraint-based models of microbial cell function into simulations of contaminant transport and fate in complex groundwater systems is a promising approach to help characterize the metabolic activities of microorganisms in natural environments. In constraint-based modeling, the specific uptake flux rates of external metabolites are usually determined by Michaelis-Menten kinetic theory. However, extensive data sets based on experimentally measured values are not always available. In this study, a genome-scale model of Pseudomonas putida was used to study the key issue of uncertainty arising from the parametrization of the influx of two growth-limiting substrates: oxygen and toluene. The results showed that simulated growth rates are highly sensitive to substrate affinity constants and that uncertainties in specific substrate uptake rates have a significant influence on the variability of simulated microbial growth. Michaelis-Menten kinetic theory does not, therefore, seem to be appropriate for descriptions of substrate uptake processes in the genome-scale model of P. putida. Microbial growth rates of P. putida in subsurface environments can only be accurately predicted if the processes of complex substrate transport and microbial uptake regulation are sufficiently understood in natural environments and if data-driven uptake flux constraints can be applied.

A neural circuit transforming temporal periodicity information into a rate-based representation in the mammalian auditory system.

PubMed

Dicke, Ulrike; Ewert, Stephan D; Dau, Torsten; Kollmeier, Birger

2007-01-01

Periodic amplitude modulations (AMs) of an acoustic stimulus are presumed to be encoded in temporal activity patterns of neurons in the cochlear nucleus. Physiological recordings indicate that this temporal AM code is transformed into a rate-based periodicity code along the ascending auditory pathway. The present study suggests a neural circuit for the transformation from the temporal to the rate-based code. Due to the neural connectivity of the circuit, bandpass shaped rate modulation transfer functions are obtained that correspond to recorded functions of inferior colliculus (IC) neurons. In contrast to previous modeling studies, the present circuit does not employ a continuously changing temporal parameter to obtain different best modulation frequencies (BMFs) of the IC bandpass units. Instead, different BMFs are yielded from varying the number of input units projecting onto different bandpass units. In order to investigate the compatibility of the neural circuit with a linear modulation filterbank analysis as proposed in psychophysical studies, complex stimuli such as tones modulated by the sum of two sinusoids, narrowband noise, and iterated rippled noise were processed by the model. The model accounts for the encoding of AM depth over a large dynamic range and for modulation frequency selective processing of complex sounds.

Kinetics of the reduction of bushveld complex chromite ore at 1416 °C

NASA Astrophysics Data System (ADS)

Soykan, O.; Eric, R. H.; King, R. P.

1991-12-01

The kinetics of the reduction of chromite ore from the LG-6 layer of the Bushveld Complex of the Transvaal in South Africa were studied at 1416 °C by the thermogravimetric analysis (TGA) technique. Spectroscopic graphite powder was employed as the reductant. The aim of this article is to present a kinetic model that satisfactorily describes the solid-state carbothermic reduction of chromite. A generalized rate model based on an ionic diffusion mechanism was developed. The model included the contribution of the interfacial area between partially reduced and unreduced zones in chromite particles and diffusion. The kinetic model described the process for degrees of reduction from 10 to 75 pet satisfactorily. It was observed that at a given particle size, the rate of reduction was controlled mainly by interfacial area up to about 40 pet reduction, after which the rate was dominated by diffusion. On the other hand, for a given degree of reduction, the contribution of the interfacial area to the rate increased, while that of diffusion decreased, with a decrease in the particle size. The value of the diffusion coefficient for the Fe2+ species at 1416 °C was calculated to be 2.63 x 10-2 cm2/s.

Exome sequencing coupled with mRNA analysis identifies NDUFAF6 as a Leigh gene.

PubMed

Bianciardi, Laura; Imperatore, Valentina; Fernandez-Vizarra, Erika; Lopomo, Angela; Falabella, Micol; Furini, Simone; Galluzzi, Paolo; Grosso, Salvatore; Zeviani, Massimo; Renieri, Alessandra; Mari, Francesca; Frullanti, Elisa

2016-11-01

We report here the case of a young male who started to show verbal fluency disturbance, clumsiness and gait anomalies at the age of 3.5years and presented bilateral striatal necrosis. Clinically, the diagnosis was compatible with Leigh syndrome but the underlying molecular defect remained elusive even after exome analysis using autosomal/X-linked recessive or de novo models. Dosage of respiratory chain activity on fibroblasts, but not in muscle, underlined a deficit in complex I. Re-analysis of heterozygous probably pathogenic variants, inherited from one healthy parent, identified the p.Ala178Pro in NDUFAF6, a complex I assembly factor. RNA analysis showed an almost mono-allelic expression of the mutated allele in blood and fibroblasts and puromycin treatment on cultured fibroblasts did not lead to the rescue of the maternal allele expression, not supporting the involvement of nonsense-mediated RNA decay mechanism. Complementation assay underlined a recovery of complex I activity after transduction of the wild-type gene. Since the second mutation was not detected and promoter methylation analysis resulted normal, we hypothesized a non-exonic event in the maternal allele affecting a regulatory element that, in conjunction with the paternal mutation, leads to the autosomal recessive disorder and the different allele expression in various tissues. This paper confirms NDUFAF6 as a genuine morbid gene and proposes the coupling of exome sequencing with mRNA analysis as a method useful for enhancing the exome sequencing detection rate when the simple application of classical inheritance models fails. Copyright © 2016 Elsevier Inc. All rights reserved.

CFD three dimensional wake analysis in complex terrain

NASA Astrophysics Data System (ADS)

Castellani, F.; Astolfi, D.; Terzi, L.

2017-11-01

Even if wind energy technology is nowadays fully developed, the use of wind energy in very complex terrain is still challenging. In particular, it is challenging to characterize the combination effects of wind ow over complex terrain and wake interactions between nearby turbines and this has a practical relevance too, for the perspective of mitigating anomalous vibrations and loads as well improving the farm efficiency. In this work, a very complex terrain site has been analyzed through a Reynolds-averaged CFD (Computational Fluid Dynamics) numerical wind field model; in the simulation the inuence of wakes has been included through the Actuator Disk (AD) approach. In particular, the upstream turbine of a cluster of 4 wind turbines having 2.3 MW of rated power is studied. The objective of this study is investigating the full three-dimensional wind field and the impact of three-dimensionality on the evolution of the waked area between nearby turbines. A post-processing method of the output of the CFD simulation is developed and this allows to estimate the wake lateral deviation and the wake width. The reliability of the numerical approach is inspired by and crosschecked through the analysis of the operational SCADA (Supervisory Control and Data Acquisition) data of the cluster of interest.

Intercellular Variation in Signaling through the TGF-β Pathway and Its Relation to Cell Density and Cell Cycle Phase*

PubMed Central

Zieba, Agata; Pardali, Katerina; Söderberg, Ola; Lindbom, Lena; Nyström, Erik; Moustakas, Aristidis; Heldin, Carl-Henrik; Landegren, Ulf

2012-01-01

Fundamental open questions in signal transduction remain concerning the sequence and distribution of molecular signaling events among individual cells. In this work, we have characterized the intercellular variability of transforming growth factor β-induced Smad interactions, providing essential information about TGF-β signaling and its dependence on the density of cell populations and the cell cycle phase. By employing the recently developed in situ proximity ligation assay, we investigated the dynamics of interactions and modifications of Smad proteins and their partners under native and physiological conditions. We analyzed the kinetics of assembly of Smad complexes and the influence of cellular environment and relation to mitosis. We report rapid kinetics of formation of Smad complexes, including native Smad2-Smad3-Smad4 trimeric complexes, in a manner influenced by the rate of proteasomal degradation of these proteins, and we found a striking cell to cell variation of signaling complexes. The single-cell analysis of TGF-β signaling in genetically unmodified cells revealed previously unknown aspects of regulation of this pathway, and it provided a basis for analysis of these signaling events to diagnose pathological perturbations in patient samples and to evaluate their susceptibility to drug treatment. PMID:22442258

Studies on the electrodeposition of tin from acidic chloride-gluconate solutions

NASA Astrophysics Data System (ADS)

Rudnik, Ewa; Włoch, Grzegorz

2013-01-01

Electrodeposition of tin from acidic chloride-gluconate baths was investigated. Equilibrium distribution of tin(II) species showed domination of Sn(II)-gluconate complexes, but for Sn2+ concentrations 50 mM or higher increased percentage of Sn(II)-chloride complexes was found. Cyclic voltammetry, anodic stripping analysis and potentiostatic measurements indicated that rate of the cathodic process is determined by the release of metal cations from gluconate complexes in diluted bath (5 mM), but for more concentrated solutions reduction of Sn(II) ions run under diffusion control. Studies of anodic response showed that it depends on the Sn(II)/Glu ratio in the bath and deposition potential due to development of different planes of metal crystal. Average effective diffusion coefficients of metal species were determined. Morphology and structure tin deposits were also presented.

Impaired activity of CCA-adding enzyme TRNT1 impacts OXPHOS complexes and cellular respiration in SIFD patient-derived fibroblasts.

PubMed

Liwak-Muir, Urszula; Mamady, Hapsatou; Naas, Turaya; Wylie, Quinlan; McBride, Skye; Lines, Matthew; Michaud, Jean; Baird, Stephen D; Chakraborty, Pranesh K; Holcik, Martin

2016-06-18

SIFD (Sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay) is a novel form of congenital sideroblastic anemia associated with B-cell immunodeficiency, periodic fevers, and developmental delay caused by mutations in the CCA-adding enzyme TRNT1, but the precise molecular pathophysiology is not known. We show that the disease causing mutations in patient-derived fibroblasts do not affect subcellular localization of TRNT1 and show no gross morphological differences when compared to control cells. Analysis of cellular respiration and oxidative phosphorylation (OXPHOS) complexes demonstrates that both basal and maximal respiration rates are decreased in patient cells, which may be attributed to an observed decrease in the abundance of select proteins of the OXPHOS complexes. Our data provides further insight into cellular pathophysiology of SIFD.

Identifying predictors of time-inhomogeneous viral evolutionary processes.

PubMed

Bielejec, Filip; Baele, Guy; Rodrigo, Allen G; Suchard, Marc A; Lemey, Philippe

2016-07-01

Various factors determine the rate at which mutations are generated and fixed in viral genomes. Viral evolutionary rates may vary over the course of a single persistent infection and can reflect changes in replication rates and selective dynamics. Dedicated statistical inference approaches are required to understand how the complex interplay of these processes shapes the genetic diversity and divergence in viral populations. Although evolutionary models accommodating a high degree of complexity can now be formalized, adequately informing these models by potentially sparse data, and assessing the association of the resulting estimates with external predictors, remains a major challenge. In this article, we present a novel Bayesian evolutionary inference method, which integrates multiple potential predictors and tests their association with variation in the absolute rates of synonymous and non-synonymous substitutions along the evolutionary history. We consider clinical and virological measures as predictors, but also changes in population size trajectories that are simultaneously inferred using coalescent modelling. We demonstrate the potential of our method in an application to within-host HIV-1 sequence data sampled throughout the infection of multiple patients. While analyses of individual patient populations lack statistical power, we detect significant evidence for an abrupt drop in non-synonymous rates in late stage infection and a more gradual increase in synonymous rates over the course of infection in a joint analysis across all patients. The former is predicted by the immune relaxation hypothesis while the latter may be in line with increasing replicative fitness during the asymptomatic stage.

Ultraclean air for prevention of postoperative infection after posterior spinal fusion with instrumentation: a comparison between surgeries performed with and without a vertical exponential filtered air-flow system.

PubMed

Gruenberg, Marcelo F; Campaner, Gustavo L; Sola, Carlos A; Ortolan, Eligio G

2004-10-15

This study retrospectively compared infection rates between adult patients after posterior spinal instrumentation procedures performed in a conventional versus an ultraclean air operating room. To evaluate if the use of ultraclean air technology could decrease the infection rate after posterior spinal arthrodesis with instrumentation. Postoperative wound infection after posterior arthrodesis remains a feared complication in spinal surgery. Although this frequent complication results in a significant problem, the employment of ultraclean air technology, as it is commonly used for arthroplasty, has not been reported as a possible alternative to reduce the infection rate after complex spine surgery. One hundred seventy-nine patients having posterior spinal fusion with instrumentation were divided into 2 groups: group I included 139 patients operated in a conventional operating room, and group II included 40 patients operated in a vertical laminar flow operating room. Patient selection was performed favoring ultraclean air technology for elective cases in which high infection risk was considered. A statistical analysis of the infection rate and its associated risk factors between both groups was assessed. We observed 18 wound infections in group I and 0 in group II. Comparison of infection rates using the chi-squared test showed a statistically significant difference (P <0.017). The use of ultraclean air technology reduced the infection rate after complex spinal procedures and appears to be an interesting alternative that still needs to be prospectively studied with a randomized protocol.

[Research of Identify Spatial Object Using Spectrum Analysis Technique].

PubMed

Song, Wei; Feng, Shi-qi; Shi, Jing; Xu, Rong; Wang, Gong-chang; Li, Bin-yu; Liu, Yu; Li, Shuang; Cao Rui; Cai, Hong-xing; Zhang, Xi-he; Tan, Yong

2015-06-01

The high precision scattering spectrum of spatial fragment with the minimum brightness of 4.2 and the resolution of 0.5 nm has been observed using spectrum detection technology on the ground. The obvious differences for different types of objects are obtained by the normalizing and discrete rate analysis of the spectral data. Each of normalized multi-frame scattering spectral line shape for rocket debris is identical. However, that is different for lapsed satellites. The discrete rate of the single frame spectrum of normalized space debris for rocket debris ranges from 0.978% to 3.067%, and the difference of oscillation and average value is small. The discrete rate for lapsed satellites ranges from 3.118 4% to 19.472 7%, and the difference of oscillation and average value relatively large. The reason is that the composition of rocket debris is single, while that of the lapsed satellites is complex. Therefore, the spectrum detection technology on the ground can be used to the classification of the spatial fragment.

Modeling the pharyngeal pressure during adult nasal high flow therapy.

PubMed

Kumar, Haribalan; Spence, Callum J T; Tawhai, Merryn H

2015-12-01

Subjects receiving nasal high flow (NHF) via wide-bore nasal cannula may experience different levels of positive pressure depending on the individual response to NHF. In this study, airflow in the nasal airway during NHF-assisted breathing is simulated and nasopharyngeal airway pressure numerically computed, to determine whether the relationship between NHF and pressure can be described by a simple equation. Two geometric models are used for analysis. In the first, 3D airway geometry is reconstructed from computed tomography images of an adult nasal airway. For the second, a simplified geometric model is derived that has the same cross-sectional area as the complex model, but is more readily amenable to analysis. Peak airway pressure is correlated as a function of nasal valve area, nostril area and cannula flow rate, for NHF rates of 20, 40 and 60 L/min. Results show that airway pressure is related by a power law to NHF rate, valve area, and nostril area. Copyright © 2015 Elsevier B.V. All rights reserved.

Crack propagation in aluminum sheets reinforced with boron-epoxy

NASA Technical Reports Server (NTRS)

Roderick, G. L.

1979-01-01

An analysis was developed to predict both the crack growth and debond growth in a reinforced system. The analysis was based on the use of complex variable Green's functions for cracked, isotropic sheets and uncracked, orthotropic sheets to calculate inplane and interlaminar stresses, stress intensities, and strain-energy-release rates. An iterative solution was developed that used the stress intensities and strain-energy-release rates to predict crack and debond growths, respectively, on a cycle-by-cycle basis. A parametric study was made of the effects of boron-epoxy composite reinforcement on crack propagation in aluminum sheets. Results show that the size of the debond area has a significant effect on the crack propagation in the aluminum. For small debond areas, the crack propagation rate is reduced significantly, but these small debonds have a strong tendency to enlarge. Debond growth is most likely to occur in reinforced systems that have a cracked metal sheet reinforced with a relatively thin composite sheet.

Influence of Proton Acceptors on the Proton-Coupled Electron Transfer Reaction Kinetics of a Ruthenium-Tyrosine Complex.

PubMed

Lennox, J Christian; Dempsey, Jillian L

2017-11-22

A polypyridyl ruthenium complex with fluorinated bipyridine ligands and a covalently bound tyrosine moiety was synthesized, and its photo-induced proton-coupled electron transfer (PCET) reactivity in acetonitrile was investigated with transient absorption spectroscopy. Using flash-quench methodology with methyl viologen as an oxidative quencher, a Ru 3+ species is generated that is capable of initiating the intramolecular PCET oxidation of the tyrosine moiety. Using a series of substituted pyridine bases, the reaction kinetics were found to vary as a function of proton acceptor concentration and identity, with no significant H/D kinetic isotope effect. Through analysis of the kinetics traces and comparison to a control complex without the tyrosine moiety, PCET reactivity was found to proceed through an equilibrium electron transfer followed by proton transfer (ET-PT) pathway in which irreversible deprotonation of the tyrosine radical cation shifts the ET equilibrium, conferring a base dependence on the reaction. Comprehensive kinetics modeling allowed for deconvolution of complex kinetics and determination of rate constants for each elementary step. Across the five pyridine bases explored, spanning a range of 4.2 pK a units, a linear free-energy relationship was found for the proton transfer rate constant with a slope of 0.32. These findings highlight the influence that proton transfer driving force exerts on PCET reaction kinetics.

Formulation of ternary complexes of glyburide with hydroxypropyl-β-cyclodextrin and other solubilizing agents and their effect on release behavior of glyburide in aqueous and buffered media at different agitation speeds.

PubMed

Singh, Sachin Kumar; Srinivasan, K K; Singare, Dhananjay S; Gowthamarajan, K; Prakash, Dev

2012-11-01

Glyburide, a sulfonylurea derivative, widely used as hypoglycaemic agent. In the present study, an attempt has been made to investigate the most effective third component which can be used with hydroxylpropyl-β-cyclodextrin (HPβCd) to form a ternary complex with glyburide in order to enhance its dissolution rate, as well as reduce the amount of HPβCd used for formulating the binary complex with glyburide. Moreover, the objective of this study was also to develop a discriminatory dissolution media in order to discriminate the effect of the different solubilizing agents used for formulating the ternary complex system. Sodium lauryl sulphate, Poloxamer-188, Polyvinylpyrrolidone K-30, lactose and L-arginine were used to formulate ternary system along with HPβCd and glyburide. The ternary system formulated with glyburide:HPβCd:L-arginine in a proportion of 1:1:0.5 has shown the fastest dissolution rate when compared to other solubilizing agents. Unbuffered aqueous media with stirring speed 50 rpm has produced the most discriminatory dissolution profiles. The DSC thermograms and the powder X-ray analysis revealed the decrease in crystallinity of the drug. This was an indication of amorphous solid dispersion or molecular encapsulation of the drug into the cyclodextrin cavity.

Pentachlorophenol dechlorination with zero valent iron: a Raman and GCMS study of the complex role of surficial iron oxides.

PubMed

Gunawardana, Buddhika; Swedlund, Peter J; Singhal, Naresh; Nieuwoudt, Michel K

2018-04-20

The dechlorination of chlorinated organic pollutants by zero valent iron (ZVI) is an important water treatment process with a complex dependence on many variables. This complexity means that there are reported inconsistencies in terms of dechlorination with ZVI and the effect of ZVI acid treatment, which are significant and are as yet unexplained. This study aims to decipher some of this complexity by combining Raman spectroscopy with gas chromatography-mass spectrometry (GC-MS) to investigate the influence of the mineralogy of the iron oxide phases on the surface of ZVI on the reductive dechlorination of pentachlorophenol (PCP). Two electrolytic iron samples (ZVI-T and ZVI-H) were found to have quite different PCP dechlorination reactivity in batch reactors under anoxic conditions. Raman analysis of the "as-received" ZVI-T indicated the iron was mainly covered with the ferrous oxide (FeO) wustite, which is non-conducting and led to a low rate of PCP dechlorination. In contrast, the dominant oxide on the "as-received" ZVI-H was magnetite which is conducting and, compared to ZVI-T, the ZVI-H rate of PCP dechlorination was four times faster. Treating the ZVI-H sample with 1 N H 2 SO 4 made small change to the composition of the oxide layers and also minute change to the rate of PCP dechlorination. However, treating the ZVI-T sample with H 2 SO 4 led to the loss of wustite so that magnetite became the dominant oxide and the rate of PCP dechlorination increased to that of the ZVI-H material. In conclusion, this study clearly shows that iron oxide mineralogy can be a contributing factor to apparent inconsistencies in the literature related to ZVI performance towards dechlorination and the effect of acid treatment on ZVI reactivity.

Reference evapotranspiration from coarse-scale and dynamically downscaled data in complex terrain: Sensitivity to interpolation and resolution

NASA Astrophysics Data System (ADS)

Strong, Courtenay; Khatri, Krishna B.; Kochanski, Adam K.; Lewis, Clayton S.; Allen, L. Niel

2017-05-01

The main objective of this study was to investigate whether dynamically downscaled high resolution (4-km) climate data from the Weather Research and Forecasting (WRF) model provide physically meaningful additional information for reference evapotranspiration (E) calculation compared to the recently published GridET framework that uses interpolation from coarser-scale simulations run at 32-km resolution. The analysis focuses on complex terrain of Utah in the western United States for years 1985-2010, and comparisons were made statewide with supplemental analyses specifically for regions with irrigated agriculture. E was calculated using the standardized equation and procedures proposed by the American Society of Civil Engineers from hourly data, and climate inputs from WRF and GridET were debiased relative to the same set of observations. For annual mean values, E from WRF (EW) and E from GridET (EG) both agreed well with E derived from observations (r2 = 0.95, bias < 2 mm). Domain-wide, EW and EG were well correlated spatially (r2 = 0.89), however local differences ΔE =EW -EG were as large as +439 mm year-1 (+26%) in some locations, and ΔE averaged +36 mm year-1. After linearly removing the effects of contrasts in solar radiation and wind speed, which are characteristically less reliable under downscaling in complex terrain, approximately half the residual variance was accounted for by contrasts in temperature and humidity between GridET and WRF. These contrasts stemmed from GridET interpolating using an assumed lapse rate of Γ = 6.5 K km-1, whereas WRF produced a thermodynamically-driven lapse rate closer to 5 K km-1 as observed in mountainous terrain. The primary conclusions are that observed lapse rates in complex terrain differ markedly from the commonly assumed Γ = 6.5 K km-1, these lapse rates can be realistically resolved via dynamical downscaling, and use of constant Γ produces differences in E of order as large as 102 mm year-1.

Interaction of rate- and size-effect using a dislocation density based strain gradient viscoplasticity model

NASA Astrophysics Data System (ADS)

Nguyen, Trung N.; Siegmund, Thomas; Tomar, Vikas; Kruzic, Jamie J.

2017-12-01

Size effects occur in non-uniform plastically deformed metals confined in a volume on the scale of micrometer or sub-micrometer. Such problems have been well studied using strain gradient rate-independent plasticity theories. Yet, plasticity theories describing the time-dependent behavior of metals in the presence of size effects are presently limited, and there is no consensus about how the size effects vary with strain rates or whether there is an interaction between them. This paper introduces a constitutive model which enables the analysis of complex load scenarios, including loading rate sensitivity, creep, relaxation and interactions thereof under the consideration of plastic strain gradient effects. A strain gradient viscoplasticity constitutive model based on the Kocks-Mecking theory of dislocation evolution, namely the strain gradient Kocks-Mecking (SG-KM) model, is established and allows one to capture both rate and size effects, and their interaction. A formulation of the model in the finite element analysis framework is derived. Numerical examples are presented. In a special virtual creep test with the presence of plastic strain gradients, creep rates are found to diminish with the specimen size, and are also found to depend on the loading rate in an initial ramp loading step. Stress relaxation in a solid medium containing cylindrical microvoids is predicted to increase with decreasing void radius and strain rate in a prior ramp loading step.

Disciplinary discourses: rates of cesarean section explained by medicine, midwifery, and feminism.

PubMed

Lee, Amy Su May; Kirkman, Maggie

2008-05-01

In the context of international concern about increasing rates of cesarean sections, we used discourse analysis to examine explanations arising from feminism and the disciplines of medicine and midwifery, and found that each was positioned differently in relation to the rising rates. Medical discourses asserted that doctors are authorities on birth and that, although cesareans are sometimes medically necessary, women recklessly choose unnecessary cesareans against medical advice. Midwifery discourses portrayed medicine as paternalistic toward both women and midwifery, and feminist discourses situated birth and women's bodies in the context of a patriarchally structured society. The findings illustrate the complex ways in which this intervention in birth is discursively constructed, and demonstrate its significance as a site of disciplinary conflict.

Economic Analysis Case Studies of Battery Energy Storage with SAM

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

DiOrio, Nicholas; Dobos, Aron; Janzou, Steven

2015-11-01

Interest in energy storage has continued to increase as states like California have introduced mandates and subsidies to spur adoption. This energy storage includes customer sited behind-the-meter storage coupled with photovoltaics (PV). This paper presents case study results from California and Tennessee, which were performed to assess the economic benefit of customer-installed systems. Different dispatch strategies, including manual scheduling and automated peak-shaving were explored to determine ideal ways to use the storage system to increase the system value and mitigate demand charges. Incentives, complex electric tariffs, and site specific load and PV data were used to perform detailed analysis. Themore » analysis was performed using the free, publically available System Advisor Model (SAM) tool. We find that installation of photovoltaics with a lithium-ion battery system priced at $300/kWh in Los Angeles under a high demand charge utility rate structure and dispatched using perfect day-ahead forecasting yields a positive net-present value, while all other scenarios cost the customer more than the savings accrued. Different dispatch strategies, including manual scheduling and automated peak-shaving were explored to determine ideal ways to use the storage system to increase the system value and mitigate demand charges. Incentives, complex electric tariffs, and site specific load and PV data were used to perform detailed analysis. The analysis was performed using the free, publically available System Advisor Model (SAM) tool. We find that installation of photovoltaics with a lithium-ion battery system priced at $300/kWh in Los Angeles under a high demand charge utility rate structure and dispatched using perfect day-ahead forecasting yields a positive net-present value, while all other scenarios cost the customer more than the savings accrued.« less

Novel application of multi dynamic trend analysis as a sensitive tool for detecting the effects of aging and congestive heart failure on heart rate variability

NASA Astrophysics Data System (ADS)

Lin, Yu-Cheng; Lin, Yu-Hsuan; Lo, Men-Tzung; Peng, Chung-Kang; Huang, Norden E.; Yang, Cheryl C. H.; Kuo, Terry B. J.

2016-02-01

The complex fluctuations in heart rate variability (HRV) reflect cardiac autonomic modulation and are an indicator of congestive heart failure (CHF). This paper proposes a novel nonlinear approach to HRV investigation, the multi dynamic trend analysis (MDTA) method, based on the empirical mode decomposition algorithm of the Hilbert-Huang transform combined with a variable-sized sliding-window method. Electrocardiographic signal data obtained from the PhysioNet database were used. These data were from subjects with CHF (mean age = 59.4 ± 8.4), an age-matched elderly healthy control group (59.3 ± 10.6), and a healthy young group (30.3 ± 4.8); the HRVs of these subjects were processed using the MDTA method, time domain analysis, and frequency domain analysis. Among all HRV parameters, the MDTA absolute value slope (MDTS) and MDTA deviation (MDTD) exhibited the greatest area under the curve (AUC) of the receiver operating characteristics in distinguishing between the CHF group and the healthy controls (AUC = 1.000) and between the healthy elderly subject group and the young subject group (AUC = 0.834 ± 0.067 for MDTS; 0.837 ± 0.066 for MDTD). The CHF subjects presented with lower MDTA indices than those of the healthy elderly subject group. Furthermore, the healthy elderly subjects exhibited lower MDTA indices than those of the young controls. The MDTA method can adaptively and automatically identify the intrinsic fluctuation on variable temporal and spatial scales when investigating complex fluctuations in the cardiac autonomic regulation effects of aging and CHF.

The evolution of genital complexity and mating rates in sexually size dimorphic spiders.

PubMed

Kuntner, Matjaž; Cheng, Ren-Chung; Kralj-Fišer, Simona; Liao, Chen-Pan; Schneider, Jutta M; Elgar, Mark A

2016-11-09

Genital diversity may arise through sexual conflict over polyandry, where male genital features function to manipulate female mating frequency against her interest. Correlated genital evolution across animal groups is consistent with this view, but a link between genital complexity and mating rates remains to be established. In sexually size dimorphic spiders, golden orbweaving spiders (Nephilidae) males mutilate their genitals to form genital plugs, but these plugs do not always prevent female polyandry. In a comparative framework, we test whether male and female genital complexity coevolve, and how these morphologies, as well as sexual cannibalism, relate to the evolution of mating systems. Using a combination of comparative tests, we show that male genital complexity negatively correlates with female mating rates, and that levels of sexual cannibalism negatively correlate with male mating rates. We also confirm a positive correlation between male and female genital complexity. The macroevolutionary trajectory is consistent with a repeated evolution from polyandry to monandry coinciding with the evolution towards more complex male genitals. These results are consistent with the predictions from sexual conflict theory, although sexual conflict may not be the only mechanism responsible for the evolution of genital complexity and mating systems. Nevertheless, our comparative evidence suggests that in golden orbweavers, male genital complexity limits female mating rates, and sexual cannibalism by females coincides with monogyny.

Source analysis of auditory steady-state responses in acoustic and electric hearing.

PubMed

Luke, Robert; De Vos, Astrid; Wouters, Jan

2017-02-15

Speech is a complex signal containing a broad variety of acoustic information. For accurate speech reception, the listener must perceive modulations over a range of envelope frequencies. Perception of these modulations is particularly important for cochlear implant (CI) users, as all commercial devices use envelope coding strategies. Prolonged deafness affects the auditory pathway. However, little is known of how cochlear implantation affects the neural processing of modulated stimuli. This study investigates and contrasts the neural processing of envelope rate modulated signals in acoustic and CI listeners. Auditory steady-state responses (ASSRs) are used to study the neural processing of amplitude modulated (AM) signals. A beamforming technique is applied to determine the increase in neural activity relative to a control condition, with particular attention paid to defining the accuracy and precision of this technique relative to other tomographies. In a cohort of 44 acoustic listeners, the location, activity and hemispheric lateralisation of ASSRs is characterised while systematically varying the modulation rate (4, 10, 20, 40 and 80Hz) and stimulation ear (right, left and bilateral). We demonstrate a complex pattern of laterality depending on both modulation rate and stimulation ear that is consistent with, and extends, existing literature. We present a novel extension to the beamforming method which facilitates source analysis of electrically evoked auditory steady-state responses (EASSRs). In a cohort of 5 right implanted unilateral CI users, the neural activity is determined for the 40Hz rate and compared to the acoustic cohort. Results indicate that CI users activate typical thalamic locations for 40Hz stimuli. However, complementary to studies of transient stimuli, the CI population has atypical hemispheric laterality, preferentially activating the contralateral hemisphere. Copyright © 2016. Published by Elsevier Inc.

Macromolecular Rate Theory (MMRT) Provides a Thermodynamics Rationale to Underpin the Convergent Temperature Response in Plant Leaf Respiration

NASA Astrophysics Data System (ADS)

Liang, L. L.; Arcus, V. L.; Heskel, M.; O'Sullivan, O. S.; Weerasinghe, L. K.; Creek, D.; Egerton, J. J. G.; Tjoelker, M. G.; Atkin, O. K.; Schipper, L. A.

2017-12-01

Temperature is a crucial factor in determining the rates of ecosystem processes such as leaf respiration (R) - the flux of plant respired carbon dioxide (CO2) from leaves to the atmosphere. Generally, respiration rate increases exponentially with temperature as modelled by the Arrhenius equation, but a recent study (Heskel et al., 2016) showed a universally convergent temperature response of R using an empirical exponential/polynomial model whereby the exponent in the Arrhenius model is replaced by a quadratic function of temperature. The exponential/polynomial model has been used elsewhere to describe shoot respiration and plant respiration. What are the principles that underlie these empirical observations? Here, we demonstrate that macromolecular rate theory (MMRT), based on transition state theory for chemical kinetics, is equivalent to the exponential/polynomial model. We re-analyse the data from Heskel et al. 2016 using MMRT to show this equivalence and thus, provide an explanation based on thermodynamics, for the convergent temperature response of R. Using statistical tools, we also show the equivalent explanatory power of MMRT when compared to the exponential/polynomial model and the superiority of both of these models over the Arrhenius function. Three meaningful parameters emerge from MMRT analysis: the temperature at which the rate of respiration is maximum (the so called optimum temperature, Topt), the temperature at which the respiration rate is most sensitive to changes in temperature (the inflection temperature, Tinf) and the overall curvature of the log(rate) versus temperature plot (the so called change in heat capacity for the system, ). The latter term originates from the change in heat capacity between an enzyme-substrate complex and an enzyme transition state complex in enzyme-catalysed metabolic reactions. From MMRT, we find the average Topt and Tinf of R are 67.0±1.2 °C and 41.4±0.7 °C across global sites. The average curvature (average negative) is -1.2±0.1 kJ.mol-1K-1. MMRT extends the classic transition state theory to enzyme-catalysed reactions and scales up to more complex processes including micro-organism growth rates and ecosystem processes.

A mechanistic approach on the self-organization of the two-component thermoreversible hydrogel of riboflavin and melamine.

PubMed

Saha, Abhijit; Manna, Swarup; Nandi, Arun K

2007-12-18

The riboflavin (R) and melamine (M) supramolecular complex in the mole ratio of 3:1 (RM31) produces a thermoreversible gel in aqueous medium. The gelation mechanism has been elucidated from morphological investigations using optical, electron, and atomic force microscopy together with time-dependent circular dichroism (CD) and photoluminescence (PL) spectroscopy. Optical microscopy indicates spherulitic morphology at lower gelation temperature (

Classroom Use of a Verbal Measure of Information Rate: An Exploratory Study.

ERIC Educational Resources Information Center

Finkler, Deana; Thompson, Patricia

The Verbal Measure of Information Rate (VMIR) is a measure of information rate which reflects the elements, features, and changes in a complex environment. Subjects rated 14 bipolar adjective pairs to indicate an appropriate description of the learning situation or information load (simple-complex, novel-familiar). The measure was administered to…

Jupiter Data Analysis Program: Analysis of Voyager wideband plasma wave observations

NASA Technical Reports Server (NTRS)

Kurth, W. S.

1983-01-01

Voyager plasma wave wideband frames from the Jovian encounters are analyzed. The 511 frames which were analyzed were chosen on the basis of low-rate spectrum analyzer data from the plasma wave receiver. These frames were obtained in regions and during times of various types of plasma or radio wave activity as determined by the low-rate, low-resolution data and were processed in order to provide high resolution measurements of the plasma wave spectrum for use in the study of a number of outstanding problems. Chorus emissions at Jupiter were analyzed. The detailed temporal and spectral form of the very complex chorus emissions near L = 8 on the Voyager 1 inbound passage was compared to both terrestrial chorus emissions as well as to the theory which was developed to explain the terrestrial waves.

Electrocatalytic Hydrogen Production by a Nickel(II) Complex with a Phosphinopyridyl Ligand.

PubMed

Tatematsu, Ryo; Inomata, Tomohiko; Ozawa, Tomohiro; Masuda, Hideki

2016-04-18

A novel nickel(II) complex [Ni(L)2 Cl]Cl with a bidentate phosphinopyridyl ligand 6-((diphenylphosphino)methyl)pyridin-2-amine (L) was synthesized as a metal-complex catalyst for hydrogen production from protons. The ligand can stabilize a low Ni oxidation state and has an amine base as a proton transfer site. The X-ray structure analysis revealed a distorted square-pyramidal Ni(II)  complex with two bidentate L ligands in a trans arrangement in the equatorial plane and a chloride anion at the apex. Electrochemical measurements with the Ni(II) complex in MeCN indicate a higher rate of hydrogen production under weak acid conditions using acetic acid as the proton source. The catalytic current increases with the stepwise addition of protons, and the turnover frequency is 8400 s(-1) in 0.1 m [NBu4 ][ClO4 ]/MeCN in the presence of acetic acid (290 equiv) at an overpotential of circa 590 mV. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Behaviour of Zinc Complexes and Zinc Sulphide Nanoparticles Revealed by Using Screen Printed Electrodes and Spectrometry

PubMed Central

Nejdl, Lukas; Ruttkay-Nedecky, Branislav; Kudr, Jiří; Kremplova, Monika; Cernei, Natalia; Prasek, Jan; Konecna, Marie; Hubalek, Jaromir; Zitka, Ondrej; Kynicky, Jindrich; Kopel, Pavel; Kizek, Rene; Adam, Vojtech

2013-01-01

In this study, we focused on microfluidic electrochemical analysis of zinc complexes (Zn(phen)(his)Cl2, Zn(his)Cl2) and ZnS quantum dots (QDs) using printed electrodes. This method was chosen due to the simple (easy to use) instrumentation and variable setting of flows. Reduction signals of zinc under the strictly defined and controlled conditions (pH, temperature, flow rate, accumulation time and applied potential) were studied. We showed that the increasing concentration of the complexes (Zn(phen)(his)Cl2, Zn(his)Cl2) led to a decrease in the electrochemical signal and a significant shift of the potential to more positive values. The most likely explanation of this result is that zinc is strongly bound in the complex and its distribution on the electrode is very limited. Changing the pH from 3.5 to 5.5 resulted in a significant intensification of the Zn(II) reduction signal. The complexes were also characterized by UV/VIS spectrophotometry, chromatography, and ESI-QTOF mass spectrometry. PMID:24233071

Eruption processes and deposit characteristics at the monogenetic Mt. Gambier Volcanic Complex, SE Australia: implications for alternating magmatic and phreatomagmatic activity

NASA Astrophysics Data System (ADS)

van Otterloo, Jozua; Cas, Raymond A. F.; Sheard, Malcolm J.

2013-08-01

The ˜5 ka Mt. Gambier Volcanic Complex in the Newer Volcanics Province, Australia is an extremely complex monogenetic, volcanic system that preserves at least 14 eruption points aligned along a fissure system. The complex stratigraphy can be subdivided into six main facies that record alternations between magmatic and phreatomagmatic eruption styles in a random manner. The facies are (1) coherent to vesicular fragmental alkali basalt (effusive/Hawaiian spatter and lava flows); (2) massive scoriaceous fine lapilli with coarse ash (Strombolian fallout); (3) bedded scoriaceous fine lapilli tuff (violent Strombolian fallout); (4) thin-medium bedded, undulating very fine lapilli in coarse ash (dry phreatomagmatic surge-modified fallout); (5) palagonite-altered, cross-bedded, medium lapilli to fine ash (wet phreatomagmatic base surges); and (6) massive, palagonite-altered, very poorly sorted tuff breccia and lapilli tuff (phreato-Vulcanian pyroclastic flows). Since most deposits are lithified, to quantify the grain size distributions (GSDs), image analysis was performed. The facies are distinct based on their GSDs and the fine ash to coarse+fine ash ratios. These provide insights into the fragmentation intensities and water-magma interaction efficiencies for each facies. The eruption chronology indicates a random spatial and temporal sequence of occurrence of eruption styles, except for a "magmatic horizon" of effusive activity occurring at both ends of the volcanic complex simultaneously. The eruption foci are located along NW-SE trending lineaments, indicating that the complex was fed by multiple dykes following the subsurface structures related to the Tartwaup Fault System. Possible factors causing vent migration along these dykes and changes in eruption styles include differences in magma ascent rates, viscosity, crystallinity, degassing and magma discharge rate, as well as hydrological parameters.

The relationship between the INTERMED patient complexity instrument and Level of Care Utilisation System (LOCUS).

PubMed

Thurber, Steven; Wilson, Ann; Realmuto, George; Specker, Sheila

2018-03-01

To investigate the concurrent and criterion validity of two independently developed measurement instruments, INTERMED and LOCUS, designed to improve the treatment and clinical management of patients with complex symptom manifestations. Participants (N = 66) were selected from hospital records based on the complexity of presenting symptoms, with tripartite diagnoses across biological, psychiatric and addiction domains. Biopsychosocial information from hospital records were submitted to INTERMED and LOCUS grids. In addition, Global Assessment of Functioning (GAF) ratings were gathered for statistical analyses. The product moment correlation between INTERMED and LOCUS was 0.609 (p = .01). Inverse zero-order correlations for INTERMED and LOCUS total score and GAF were obtained. However, only the beta weight for LOCUS and GAF was significant. An exploratory principal components analysis further illuminated areas of convergence between the instruments. INTERMED and LOCUS demonstrated shared variance. INTERMED appeared more sensitive to complex medical conditions and severe physiological reactions, whereas LOCUS findings are more strongly related to psychiatric symptoms. Implications are discussed.

Evaluation of a complex healthcare intervention to increase smoking cessation in pregnant women: interrupted time series analysis with economic evaluation.

PubMed

Bell, Ruth; Glinianaia, Svetlana V; Waal, Zelda van der; Close, Andrew; Moloney, Eoin; Jones, Susan; Araújo-Soares, Vera; Hamilton, Sharon; Milne, Eugene Mg; Shucksmith, Janet; Vale, Luke; Willmore, Martyn; White, Martin; Rushton, Steven

2018-01-01

To evaluate the effectiveness of a complex intervention to improve referral and treatment of pregnant smokers in routine practice, and to assess the incremental costs to the National Health Service (NHS) per additional woman quitting smoking. Interrupted time series analysis of routine data before and after introducing the intervention, within-study economic evaluation. Eight acute NHS hospital trusts and 12 local authority areas in North East England. 37 726 records of singleton delivery including 10 594 to mothers classified as smoking during pregnancy. A package of measures implemented in trusts and smoking cessation services, aimed at increasing the proportion of pregnant smokers quitting during pregnancy, comprising skills training for healthcare and smoking cessation staff; universal carbon monoxide monitoring with routine opt-out referral for smoking cessation support; provision of carbon monoxide monitors and supporting materials; and an explicit referral pathway and follow-up protocol. Referrals to smoking cessation services; probability of quitting smoking during pregnancy; additional costs to health services; incremental cost per additional woman quitting. After introduction of the intervention, the referral rate increased more than twofold (incidence rate ratio=2.47, 95% CI 2.16 to 2.81) and the probability of quitting by delivery increased (adjusted OR=1.81, 95% CI 1.54 to 2.12). The additional cost per delivery was £31 and the incremental cost per additional quit was £952; 31 pregnant women needed to be treated for each additional quitter. The implementation of a system-wide complex healthcare intervention was associated with significant increase in rates of quitting by delivery. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Characterization of Factors Affecting Nanoparticle Tracking Analysis Results With Synthetic and Protein Nanoparticles.

PubMed

Krueger, Aaron B; Carnell, Pauline; Carpenter, John F

2016-04-01

In many manufacturing and research areas, the ability to accurately monitor and characterize nanoparticles is becoming increasingly important. Nanoparticle tracking analysis is rapidly becoming a standard method for this characterization, yet several key factors in data acquisition and analysis may affect results. Nanoparticle tracking analysis is prone to user input and bias on account of a high number of parameters available, contains a limited analysis volume, and individual sample characteristics such as polydispersity or complex protein solutions may affect analysis results. This study systematically addressed these key issues. The integrated syringe pump was used to increase the sample volume analyzed. It was observed that measurements recorded under flow caused a reduction in total particle counts for both polystyrene and protein particles compared to those collected under static conditions. In addition, data for polydisperse samples tended to lose peak resolution at higher flow rates, masking distinct particle populations. Furthermore, in a bimodal particle population, a bias was seen toward the larger species within the sample. The impacts of filtration on an agitated intravenous immunoglobulin sample and operating parameters including "MINexps" and "blur" were investigated to optimize the method. Taken together, this study provides recommendations on instrument settings and sample preparations to properly characterize complex samples. Copyright © 2016. Published by Elsevier Inc.

The experience of seeking, gaining and maintaining employment after traumatic spinal cord injury and the vocational pathways involved.

PubMed

Hilton, Gillean; Unsworth, Carolyn A; Stuckey, Ruth; Murphy, Gregory C

2018-01-01

Vocational potential in people with spinal cord injury (SCI) are unrealised with rates of employment substantially lower than in the labour force participation of the general population and the pre-injury employment rates. To understand the experience and pathway of people achieving employment outcome after traumatic spinal cord injury by; classifying participants into employment outcome groups of stable, unstable and without employment; identifying pre and post-injury pathways for participants in each group and, exploring the experiences of people of seeking, gaining and maintaining employment. Thirty-one participants were interviewed. Mixed methods approach including interpretive phenomenological analysis and vocational pathway mapping of quantitative data. The most common pathway identified was from study and work pre-injury to stable employment post-injury. Four super-ordinate themes were identified from the interpretive phenomenological analysis; expectations of work, system impacts, worker identity and social supports. Implications for clinical practice include fostering cultural change, strategies for system navigation, promotion of worker identity and optimal use of social supports. The findings increase insight and understanding of the complex experience of employment after spinal cord injury. There is opportunity to guide experimental research, policy development and education concerning the complexity of the return to work experience and factors that influence pathways.

Identifying online user reputation of user-object bipartite networks

NASA Astrophysics Data System (ADS)

Liu, Xiao-Lu; Liu, Jian-Guo; Yang, Kai; Guo, Qiang; Han, Jing-Ti

2017-02-01

Identifying online user reputation based on the rating information of the user-object bipartite networks is important for understanding online user collective behaviors. Based on the Bayesian analysis, we present a parameter-free algorithm for ranking online user reputation, where the user reputation is calculated based on the probability that their ratings are consistent with the main part of all user opinions. The experimental results show that the AUC values of the presented algorithm could reach 0.8929 and 0.8483 for the MovieLens and Netflix data sets, respectively, which is better than the results generated by the CR and IARR methods. Furthermore, the experimental results for different user groups indicate that the presented algorithm outperforms the iterative ranking methods in both ranking accuracy and computation complexity. Moreover, the results for the synthetic networks show that the computation complexity of the presented algorithm is a linear function of the network size, which suggests that the presented algorithm is very effective and efficient for the large scale dynamic online systems.

Automated digital magnetofluidics

NASA Astrophysics Data System (ADS)

Schneider, J.; Garcia, A. A.; Marquez, M.

2008-08-01

Drops can be moved in complex patterns on superhydrophobic surfaces using a reconfigured computer-controlled x-y metrology stage with a high degree of accuracy, flexibility, and reconfigurability. The stage employs a DMC-4030 controller which has a RISC-based, clock multiplying processor with DSP functions, accepting encoder inputs up to 22 MHz, provides servo update rates as high as 32 kHz, and processes commands at rates as fast as 40 milliseconds. A 6.35 mm diameter cylindrical NdFeB magnet is translated by the stage causing water drops to move by the action of induced magnetization of coated iron microspheres that remain in the drop and are attracted to the rare earth magnet through digital magnetofluidics. Water drops are easily moved in complex patterns in automated digital magnetofluidics at an average speed of 2.8 cm/s over a superhydrophobic polyethylene surface created by solvent casting. With additional components, some potential uses for this automated microfluidic system include characterization of superhydrophobic surfaces, water quality analysis, and medical diagnostics.

Unsteady Analysis of Turbine Main Flow Coupled with Secondary Air Flow

NASA Technical Reports Server (NTRS)

Hah, Chunill

2006-01-01

Two numerical approaches are used to model the interaction between the turbine main gas flow and the wheelspace cavity seal flow. The 3-D, unsteady Reynolds-averaged Navier-Stokes equations are solved with a CFD code based on a structured grid to study the interaction between the turbine main gas flow and the wheelspace cavity seal flow. A CFD code based on an unstructured grid is used to solve detailed flow feature in the cavity seal which has a complex geometry. The numerical results confirm various observations from earlier experimental studies under similar flow conditions. When the flow rate through the rim cavity seal is increased, the ingestion of the main turbine flow into the rim seal area decreases drastically. However, a small amount of main gas flow is ingested to the rim seal area even with very high level of seal flow rate. This is due to the complex nature of 3-D, unsteady flow interaction near the hub of the turbine stage.

A new method for 3D thinning of hybrid shaped porous media using artificial intelligence. Application to trabecular bone.

PubMed

Jennane, Rachid; Aufort, Gabriel; Benhamou, Claude Laurent; Ceylan, Murat; Ozbay, Yüksel; Ucan, Osman Nuri

2012-04-01

Curve and surface thinning are widely-used skeletonization techniques for modeling objects in three dimensions. In the case of disordered porous media analysis, however, neither is really efficient since the internal geometry of the object is usually composed of both rod and plate shapes. This paper presents an alternative to compute a hybrid shape-dependent skeleton and its application to porous media. The resulting skeleton combines 2D surfaces and 1D curves to represent respectively the plate-shaped and rod-shaped parts of the object. For this purpose, a new technique based on neural networks is proposed: cascade combinations of complex wavelet transform (CWT) and complex-valued artificial neural network (CVANN). The ability of the skeleton to characterize hybrid shaped porous media is demonstrated on a trabecular bone sample. Results show that the proposed method achieves high accuracy rates about 99.78%-99.97%. Especially, CWT (2nd level)-CVANN structure converges to optimum results as high accuracy rate-minimum time consumption.

Stress reaction process-based hierarchical recognition algorithm for continuous intrusion events in optical fiber prewarning system

NASA Astrophysics Data System (ADS)

Qu, Hongquan; Yuan, Shijiao; Wang, Yanping; Yang, Dan

2018-04-01

To improve the recognition performance of optical fiber prewarning system (OFPS), this study proposed a hierarchical recognition algorithm (HRA). Compared with traditional methods, which employ only a complex algorithm that includes multiple extracted features and complex classifiers to increase the recognition rate with a considerable decrease in recognition speed, HRA takes advantage of the continuity of intrusion events, thereby creating a staged recognition flow inspired by stress reaction. HRA is expected to achieve high-level recognition accuracy with less time consumption. First, this work analyzed the continuity of intrusion events and then presented the algorithm based on the mechanism of stress reaction. Finally, it verified the time consumption through theoretical analysis and experiments, and the recognition accuracy was obtained through experiments. Experiment results show that the processing speed of HRA is 3.3 times faster than that of a traditional complicated algorithm and has a similar recognition rate of 98%. The study is of great significance to fast intrusion event recognition in OFPS.

Multiple choice questions can be designed or revised to challenge learners' critical thinking.

PubMed

Tractenberg, Rochelle E; Gushta, Matthew M; Mulroney, Susan E; Weissinger, Peggy A

2013-12-01

Multiple choice (MC) questions from a graduate physiology course were evaluated by cognitive-psychology (but not physiology) experts, and analyzed statistically, in order to test the independence of content expertise and cognitive complexity ratings of MC items. Integration of higher order thinking into MC exams is important, but widely known to be challenging-perhaps especially when content experts must think like novices. Expertise in the domain (content) may actually impede the creation of higher-complexity items. Three cognitive psychology experts independently rated cognitive complexity for 252 multiple-choice physiology items using a six-level cognitive complexity matrix that was synthesized from the literature. Rasch modeling estimated item difficulties. The complexity ratings and difficulty estimates were then analyzed together to determine the relative contributions (and independence) of complexity and difficulty to the likelihood of correct answers on each item. Cognitive complexity was found to be statistically independent of difficulty estimates for 88 % of items. Using the complexity matrix, modifications were identified to increase some item complexities by one level, without affecting the item's difficulty. Cognitive complexity can effectively be rated by non-content experts. The six-level complexity matrix, if applied by faculty peer groups trained in cognitive complexity and without domain-specific expertise, could lead to improvements in the complexity targeted with item writing and revision. Targeting higher order thinking with MC questions can be achieved without changing item difficulties or other test characteristics, but this may be less likely if the content expert is left to assess items within their domain of expertise.

On improving the performance of nonphotochemical quenching in CP29 light-harvesting antenna complex

NASA Astrophysics Data System (ADS)

Berman, Gennady P.; Nesterov, Alexander I.; Sayre, Richard T.; Still, Susanne

2016-03-01

We model and simulate the performance of charge-transfer in nonphotochemical quenching (NPQ) in the CP29 light-harvesting antenna-complex associated with photosystem II (PSII). The model consists of five discrete excitonic energy states and two sinks, responsible for the potentially damaging processes and charge-transfer channels, respectively. We demonstrate that by varying (i) the parameters of the chlorophyll-based dimer, (ii) the resonant properties of the protein-solvent environment interaction, and (iii) the energy transfer rates to the sinks, one can significantly improve the performance of the NPQ. Our analysis suggests strategies for improving the performance of the NPQ in response to environmental changes, and may stimulate experimental verification.

Enhanced lithium storage performance of hierarchical CuO nanomaterials with surface fractal characteristics

NASA Astrophysics Data System (ADS)

Li, Ang; He, Renyue; Bian, Zhuo; Song, Huaihe; Chen, Xiaohong; Zhou, Jisheng

2018-06-01

Self-assembled hierarchical CuO nanostructures with fractal structures were prepared by a mild method and exhibited excellent lithium storage properties, certain of which even demonstrated a high reversible capacity of 827 mAh g-1 at a rate of 0.1 C. An interesting phenomenon was observed that the electrochemical performance varies along with the structure complexity, and the products with higher surface factal dimensions exhibited larger capability and better cyclability. Structural and electrochemical analysis methods were used to explore the lithiation kinetics of the samples and the reasons for the outstanding electrochemical performances related to the complexities of hierarchical nanostructures and the irregularities of surface and mass distribution.

Short relaxation times but long transient times in both simple and complex reaction networks

PubMed Central

Henry, Adrien; Martin, Olivier C.

2016-01-01

When relaxation towards an equilibrium or steady state is exponential at large times, one usually considers that the associated relaxation time τ, i.e. the inverse of the decay rate, is the longest characteristic time in the system. However, that need not be true, other times such as the lifetime of an infinitesimal perturbation can be much longer. In the present work, we demonstrate that this paradoxical property can arise even in quite simple systems such as a linear chain of reactions obeying mass action (MA) kinetics. By mathematical analysis of simple reaction networks, we pin-point the reason why the standard relaxation time does not provide relevant information on the potentially long transient times of typical infinitesimal perturbations. Overall, we consider four characteristic times and study their behaviour in both simple linear chains and in more complex reaction networks taken from the publicly available database ‘Biomodels’. In all these systems, whether involving MA rates, Michaelis–Menten reversible kinetics, or phenomenological laws for reaction rates, we find that the characteristic times corresponding to lifetimes of tracers and of concentration perturbations can be significantly longer than τ. PMID:27411726

Sputtering, Plasma Chemistry, and RF Sheath Effects in Low-Temperature and Fusion Plasma Modeling

NASA Astrophysics Data System (ADS)

Jenkins, Thomas G.; Kruger, Scott E.; McGugan, James M.; Pankin, Alexei Y.; Roark, Christine M.; Smithe, David N.; Stoltz, Peter H.

2016-09-01

A new sheath boundary condition has been implemented in VSim, a plasma modeling code which makes use of both PIC/MCC and fluid FDTD representations. It enables physics effects associated with DC and RF sheath formation - local sheath potential evolution, heat/particle fluxes, and sputtering effects on complex plasma-facing components - to be included in macroscopic-scale plasma simulations that need not resolve sheath scale lengths. We model these effects in typical ICRF antenna operation scenarios on the Alcator C-Mod fusion device, and present comparisons of our simulation results with experimental data together with detailed 3D animations of antenna operation. Complex low-temperature plasma chemistry modeling in VSim is facilitated by MUNCHKIN, a standalone python/C++/SQL code that identifies possible reaction paths for a given set of input species, solves 1D rate equations for the ensuing system's chemical evolution, and generates VSim input blocks with appropriate cross-sections/reaction rates. These features, as well as principal path analysis (to reduce the number of simulated chemical reactions while retaining accuracy) and reaction rate calculations from user-specified distribution functions, will also be demonstrated. Supported by the U.S. Department of Energy's SBIR program, Award DE-SC0009501.

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

Pilgrim, Corey D.; Zavarin, Mavrik; Casey, William H.

Here, the rates of ligand exchange into the geochemically important [NpO 2(CO 3) 3] 4– aqueous complex are measured as a function of pressure in order to complement existing data on the isostructural [UO 2(CO 3) 3] 4– complex. Experiments are conducted at pH conditions where the rate of exchange is independent of the proton concentration. Unexpectedly, the experiments show a distinct difference in the pressure dependencies of rates of exchange for the uranyl and neptunyl complexes.

Analysis of Instantaneous Linear, Nonlinear and Complex Cardiovascular Dynamics from Videophotoplethysmography.

PubMed

Valenza, Gaetano; Iozzia, Luca; Cerina, Luca; Mainardi, Luca; Barbieri, Riccardo

2018-05-01

There is a fast growing interest in the use of non-contact devices for health and performance assessment in humans. In particular, the use of non-contact videophotoplethysmography (vPPG) has been recently demonstrated as a feasible way to extract cardiovascular information. Nevertheless, proper validation of vPPG-derived heartbeat dynamics is still missing. We aim to an in-depth validation of time-varying, linear and nonlinear/complex dynamics of the pulse rate variability extracted from vPPG. We apply inhomogeneous pointprocess nonlinear models to assess instantaneous measures defined in the time, frequency, and bispectral domains as estimated through vPPG and standard ECG. Instantaneous complexity measures, such as the instantaneous Lyapunov exponents and the recently defined inhomogeneous point-process approximate and sample entropy, were estimated as well. Video recordings were processed using our recently proposed method based on zerophase principal component analysis. Experimental data were gathered from 60 young healthy subjects (age: 24±3 years) undergoing postural changes (rest-to-stand maneuver). Group averaged results show that there is an overall agreement between linear and nonlinear/complexity indices computed from ECG and vPPG during resting state conditions. However, important differences are found, particularly in the bispectral and complexity domains, in recordings where the subjects has been instructed to stand up. Although significant differences exist between cardiovascular estimates from vPPG and ECG, it is very promising that instantaneous sympathovagal changes, as well as time-varying complex dynamics, were correctly identified, especially during resting state. In addition to a further improvement of the video signal quality, more research is advocated towards a more precise estimation of cardiovascular dynamics by a comprehensive nonlinear/complex paradigm specifically tailored to the non-contact quantification. Schattauer GmbH.

Defining and Detecting Complex Peak Relationships in Mass Spectral Data: The Mz.unity Algorithm.

PubMed

Mahieu, Nathaniel G; Spalding, Jonathan L; Gelman, Susan J; Patti, Gary J

2016-09-20

Analysis of a single analyte by mass spectrometry can result in the detection of more than 100 degenerate peaks. These degenerate peaks complicate spectral interpretation and are challenging to annotate. In mass spectrometry-based metabolomics, this degeneracy leads to inflated false discovery rates, data sets containing an order of magnitude more features than analytes, and an inefficient use of resources during data analysis. Although software has been introduced to annotate spectral degeneracy, current approaches are unable to represent several important classes of peak relationships. These include heterodimers and higher complex adducts, distal fragments, relationships between peaks in different polarities, and complex adducts between features and background peaks. Here we outline sources of peak degeneracy in mass spectra that are not annotated by current approaches and introduce a software package called mz.unity to detect these relationships in accurate mass data. Using mz.unity, we find that data sets contain many more complex relationships than we anticipated. Examples include the adduct of glutamate and nicotinamide adenine dinucleotide (NAD), fragments of NAD detected in the same or opposite polarities, and the adduct of glutamate and a background peak. Further, the complex relationships we identify show that several assumptions commonly made when interpreting mass spectral degeneracy do not hold in general. These contributions provide new tools and insight to aid in the annotation of complex spectral relationships and provide a foundation for improved data set identification. Mz.unity is an R package and is freely available at https://github.com/nathaniel-mahieu/mz.unity as well as our laboratory Web site http://pattilab.wustl.edu/software/ .

2-Deoxyglucose conjugated platinum (II) complexes for targeted therapy: design, synthesis, and antitumor activity.

PubMed

Mi, Qian; Ma, Yuru; Gao, Xiangqian; Liu, Ran; Liu, Pengxing; Mi, Yi; Fu, Xuegang; Gao, Qingzhi

2016-11-01

Malignant neoplasms exhibit an elevated rate of glycolysis over normal cells. To target the Warburg effect, we designed a new series of 2-deoxyglucose (2-DG) conjugated platinum (II) complexes for glucose transporter 1 (GLUT1)-mediated anticancer drug delivery. The potential GLUT1 transportability of the complexes was investigated through a comparative molecular docking analysis utilizing the latest GLUT1 protein crystal structure. The key binding site for 2-DG as GLUT1's substrate was identified with molecular dynamics simulation, and the docking study demonstrated that the 2-DG conjugated platinum (II) complexes can be recognized by the same binding site as potential GLUT1 substrate. The conjugates were synthesized and evaluated for in vitro cytotoxicity study with seven human cancer cell lines. The results of this study revealed that 2-DG conjugated platinum (II) complexes are GLUT1 transportable substrates and exhibit improved cytotoxicities in cancer cell lines that over express GLUT1 when compared to the clinical drug, Oxaliplatin. The correlation between GLUT1 expression and antitumor effects are also confirmed. The study provides fundamental information supporting the potential of the 2-DG conjugated platinum (II) complexes as lead compounds for further pharmaceutical R&D.

ECG Signal Analysis and Arrhythmia Detection using Wavelet Transform

NASA Astrophysics Data System (ADS)

Kaur, Inderbir; Rajni, Rajni; Marwaha, Anupma

2016-12-01

Electrocardiogram (ECG) is used to record the electrical activity of the heart. The ECG signal being non-stationary in nature, makes the analysis and interpretation of the signal very difficult. Hence accurate analysis of ECG signal with a powerful tool like discrete wavelet transform (DWT) becomes imperative. In this paper, ECG signal is denoised to remove the artifacts and analyzed using Wavelet Transform to detect the QRS complex and arrhythmia. This work is implemented in MATLAB software for MIT/BIH Arrhythmia database and yields the sensitivity of 99.85 %, positive predictivity of 99.92 % and detection error rate of 0.221 % with wavelet transform. It is also inferred that DWT outperforms principle component analysis technique in detection of ECG signal.

[Complex Trauma-related Disorders in Research and Practice].

PubMed

Metzner, Franka; Pahlke, Stephanie; Diesing, Alice; Marin, Nina; Klasen, Fionna; Pawils, Silke; Schulte-Markwort, Michael; Richter-Appelt, Hertha

2018-03-01

Complex Trauma-related Disorders in Research and Practice Frequent traumata in childhood and adolescence are long-term or repeated interpersonal traumata caused by perpetrators in the close environment of the minors. For the description of the extensive symptoms after interpersonal Type II traumata, the complex trauma-related disorders Complex Posttraumatic Stress Disorder (CPTSD) or Disorder of Extreme Stress Not Otherwise Specified (DESNOS) and the Developmental Trauma Disorder (DTD) are being discussed for inclusion in the classification systems for mental disorders. Scientific knowledge and practical experiences regarding CPTSD, DESNOS and DTD in children and adolescents up to 18 years were examined by 1) a Systematic Review of 1,070 publications identified by database research and additional search strategies, and 2) a nationwide online survey of 374 psychotherapists and psychiatrists for children and adolescents in Germany. Of 13 included empirical studies (8 CPTSD or DESNOS, 5 DTD), 9 were conducted in the USA, 4 based on file coding and 3 on secondary data analysis and only 7 reported diagnosis rates (range: 0-78 %). Of the interviewed therapists, 100 % considered the CPTSD as being met with at least one patient with interpersonal traumata up to 18 years of age in 2014 and 99 % gave this estimate for the DTD. Two thirds of therapists rated the diagnostic option CPTSD and DTD as "very often" or "often" helpful for their therapeutic work with children and adolescents. While empirical data available is to be considered insufficient and characterized by methodological limitations, the relevance of complex trauma-related disorders is perceived as high by practitioners.

Evidence of non-extensivity and complexity in the seismicity observed during 2011-2012 at the Santorini volcanic complex, Greece

NASA Astrophysics Data System (ADS)

Vallianatos, F.; Tzanis, A.; Michas, G.; Papadakis, G.

2012-04-01

Since the middle of summer 2011, an increase in the seismicity rates of the volcanic complex system of Santorini Island, Greece, was observed. In the present work, the temporal distribution of seismicity, as well as the magnitude distribution of earthquakes, have been studied using the concept of Non-Extensive Statistical Physics (NESP; Tsallis, 2009) along with the evolution of Shanon entropy H (also called information entropy). The analysis is based on the earthquake catalogue of the Geodynamic Institute of the National Observatory of Athens for the period July 2011-January 2012 (http://www.gein.noa.gr/). Non-Extensive Statistical Physics, which is a generalization of Boltzmann-Gibbs statistical physics, seems a suitable framework for studying complex systems. The observed distributions of seismicity rates at Santorini can be described (fitted) with NESP models to exceptionally well. This implies the inherent complexity of the Santorini volcanic seismicity, the applicability of NESP concepts to volcanic earthquake activity and the usefulness of NESP in investigating phenomena exhibiting multifractality and long-range coupling effects. Acknowledgments. This work was supported in part by the THALES Program of the Ministry of Education of Greece and the European Union in the framework of the project entitled "Integrated understanding of Seismicity, using innovative Methodologies of Fracture mechanics along with Earthquake and non extensive statistical physics - Application to the geodynamic system of the Hellenic Arc. SEISMO FEAR HELLARC". GM and GP wish to acknowledge the partial support of the Greek State Scholarships Foundation (ΙΚΥ).

Heart Rate Dynamics after Combined Strength and Endurance Training in Middle-Aged Women: Heterogeneity of Responses

PubMed Central

Goldberger, Ary L.; Tulppo, Mikko P.; Laaksonen, David E.; Nyman, Kai; Keskitalo, Marko; Häkkinen, Arja; Häkkinen, Keijo

2013-01-01

The loss of complexity in physiological systems may be a dynamical biomarker of aging and disease. In this study the effects of combined strength and endurance training compared with those of endurance training or strength training alone on heart rate (HR) complexity and traditional HR variability indices were examined in middle-aged women. 90 previously untrained female volunteers between the age of 40 and 65 years completed a 21 week progressive training period of either strength training, endurance training or their combination, or served as controls. Continuous HR time series were obtained during supine rest and submaximal steady state exercise. The complexity of HR dynamics was assessed using multiscale entropy analysis. In addition, standard time and frequency domain measures were also computed. Endurance training led to increases in HR complexity and selected time and frequency domain measures of HR variability (P<0.01) when measured during exercise. Combined strength and endurance training or strength training alone did not produce significant changes in HR dynamics. Inter-subject heterogeneity of responses was particularly noticeable in the combined training group. At supine rest, no training-induced changes in HR parameters were observed in any of the groups. The present findings emphasize the potential utility of endurance training in increasing the complex variability of HR in middle-aged women. Further studies are needed to explore the combined endurance and strength training adaptations and possible gender and age related factors, as well as other mechanisms, that may mediate the effects of different training regimens on HR dynamics. PMID:24013586

Recurrence quantification analysis of heart rate variability and respiratory flow series in patients on weaning trials.

PubMed

Arcentales, Andrés; Giraldo, Beatriz F; Caminal, Pere; Benito, Salvador; Voss, Andreas

2011-01-01

Autonomic nervous system regulates the behavior of cardiac and respiratory systems. Its assessment during the ventilator weaning can provide information about physio-pathological imbalances. This work proposes a non linear analysis of the complexity of the heart rate variability (HRV) and breathing duration (T(Tot)) applying recurrence plot (RP) and their interaction joint recurrence plot (JRP). A total of 131 patients on weaning trials from mechanical ventilation were analyzed: 92 patients with successful weaning (group S) and 39 patients that failed to maintain spontaneous breathing (group F). The results show that parameters as determinism (DET), average diagonal line length (L), and entropy (ENTR), are statistically significant with RP for T(Tot) series, but not with HRV. When comparing the groups with JRP, all parameters have been relevant. In all cases, mean values of recurrence quantification analysis are higher in the group S than in the group F. The main differences between groups were found on the diagonal and vertical structures of the joint recurrence plot.

Frame sequences analysis technique of linear objects movement

NASA Astrophysics Data System (ADS)

Oshchepkova, V. Y.; Berg, I. A.; Shchepkin, D. V.; Kopylova, G. V.

2017-12-01

Obtaining data by noninvasive methods are often needed in many fields of science and engineering. This is achieved through video recording in various frame rate and light spectra. In doing so quantitative analysis of movement of the objects being studied becomes an important component of the research. This work discusses analysis of motion of linear objects on the two-dimensional plane. The complexity of this problem increases when the frame contains numerous objects whose images may overlap. This study uses a sequence containing 30 frames at the resolution of 62 × 62 pixels and frame rate of 2 Hz. It was required to determine the average velocity of objects motion. This velocity was found as an average velocity for 8-12 objects with the error of 15%. After processing dependencies of the average velocity vs. control parameters were found. The processing was performed in the software environment GMimPro with the subsequent approximation of the data obtained using the Hill equation.

Modeling the cardiovascular system using a nonlinear additive autoregressive model with exogenous input

NASA Astrophysics Data System (ADS)

Riedl, M.; Suhrbier, A.; Malberg, H.; Penzel, T.; Bretthauer, G.; Kurths, J.; Wessel, N.

2008-07-01

The parameters of heart rate variability and blood pressure variability have proved to be useful analytical tools in cardiovascular physics and medicine. Model-based analysis of these variabilities additionally leads to new prognostic information about mechanisms behind regulations in the cardiovascular system. In this paper, we analyze the complex interaction between heart rate, systolic blood pressure, and respiration by nonparametric fitted nonlinear additive autoregressive models with external inputs. Therefore, we consider measurements of healthy persons and patients suffering from obstructive sleep apnea syndrome (OSAS), with and without hypertension. It is shown that the proposed nonlinear models are capable of describing short-term fluctuations in heart rate as well as systolic blood pressure significantly better than similar linear ones, which confirms the assumption of nonlinear controlled heart rate and blood pressure. Furthermore, the comparison of the nonlinear and linear approaches reveals that the heart rate and blood pressure variability in healthy subjects is caused by a higher level of noise as well as nonlinearity than in patients suffering from OSAS. The residue analysis points at a further source of heart rate and blood pressure variability in healthy subjects, in addition to heart rate, systolic blood pressure, and respiration. Comparison of the nonlinear models within and among the different groups of subjects suggests the ability to discriminate the cohorts that could lead to a stratification of hypertension risk in OSAS patients.

Interfacial hydration, dynamics and electron transfer: multi-scale ET modeling of the transient [myoglobin, cytochrome b5] complex.

PubMed

Keinan, Shahar; Nocek, Judith M; Hoffman, Brian M; Beratan, David N

2012-10-28

Formation of a transient [myoglobin (Mb), cytochrome b(5) (cyt b(5))] complex is required for the reductive repair of inactive ferri-Mb to its functional ferro-Mb state. The [Mb, cyt b(5)] complex exhibits dynamic docking (DD), with its cyt b(5) partner in rapid exchange at multiple sites on the Mb surface. A triple mutant (Mb(3M)) was designed as part of efforts to shift the electron-transfer process to the simple docking (SD) regime, in which reactive binding occurs at a restricted, reactive region on the Mb surface that dominates the docked ensemble. An electrostatically-guided brownian dynamics (BD) docking protocol was used to generate an initial ensemble of reactive configurations of the complex between unrelaxed partners. This ensemble samples a broad and diverse array of heme-heme distances and orientations. These configurations seeded all-atom constrained molecular dynamics simulations (MD) to generate relaxed complexes for the calculation of electron tunneling matrix elements (T(DA)) through tunneling-pathway analysis. This procedure for generating an ensemble of relaxed complexes combines the ability of BD calculations to sample the large variety of available conformations and interprotein distances, with the ability of MD to generate the atomic level information, especially regarding the structure of water molecules at the protein-protein interface, that defines electron-tunneling pathways. We used the calculated T(DA) values to compute ET rates for the [Mb(wt), cyt b(5)] complex and for the complex with a mutant that has a binding free energy strengthened by three D/E → K charge-reversal mutations, [Mb(3M), cyt b(5)]. The calculated rate constants are in agreement with the measured values, and the mutant complex ensemble has many more geometries with higher T(DA) values than does the wild-type Mb complex. Interestingly, water plays a double role in this electron-transfer system, lowering the tunneling barrier as well as inducing protein interface remodeling that screens the repulsion between the negatively-charged propionates of the two hemes.

Epidemiology and Outcomes After In-Hospital Cardiac Arrest After Pediatric Cardiac Surgery

PubMed Central

Gupta, Punkaj; Jacobs, Jeffrey P.; Pasquali, Sara K.; Hill, Kevin D.; Gaynor, J. William; O’Brien, Sean M.; He, Max; Sheng, Shubin; Schexnayder, Stephen M.; Berg, Robert A.; Nadkarni, Vinay M.; Imamura, Michiaki; Jacobs, Marshall L.

2014-01-01

Background Multicenter data regarding cardiac arrest in children undergoing heart operations are limited. We describe epidemiology and outcomes associated with postoperative cardiac arrest in a large multiinstitutional cohort. Methods Patients younger than 18 years in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2007 through 2012) were included. Patient factors, operative characteristics, and outcomes were described for patients with and without postoperative cardiac arrest. Multivariable models were used to evaluate the association of center volume with cardiac arrest rate and mortality after cardiac arrest, adjusting for patient and procedural factors. Results Of 70,270 patients (97 centers), 1,843 (2.6%) had postoperative cardiac arrest. Younger age, lower weight, and presence of preoperative morbidities (all p < 0.0001) were associated with cardiac arrest. Arrest rate increased with procedural complexity across common benchmark operations, ranging from 0.7% (ventricular septal defect repair) to 12.7% (Norwood operation). Cardiac arrest was associated with significant mortality risk across procedures, ranging from 15.4% to 62.3% (all p < 0.0001). In multivariable analysis, arrest rate was not associated with center volume (odds ratio, 1.06; 95% confidence interval, 0.71 to 1.57 in low- versus high-volume centers). However, mortality after cardiac arrest was higher in low-volume centers (odds ratio, 2.00; 95% confidence interval, 1.52 to 2.63). This association was present for both high- and low-complexity operations. Conclusions Cardiac arrest carries a significant mortality risk across the stratum of procedural complexity. Although arrest rates are not associated with center volume, lower-volume centers have increased mortality after cardiac arrest. Further study of mechanisms to prevent cardiac arrest and to reduce mortality in those with an arrest is warranted. PMID:25443018

Scalable modulation technology and the tradeoff of reach, spectral efficiency, and complexity

NASA Astrophysics Data System (ADS)

Bosco, Gabriella; Pilori, Dario; Poggiolini, Pierluigi; Carena, Andrea; Guiomar, Fernando

2017-01-01

Bandwidth and capacity demand in metro, regional, and long-haul networks is increasing at several tens of percent per year, driven by video streaming, cloud computing, social media and mobile applications. To sustain this traffic growth, an upgrade of the widely deployed 100-Gbit/s long-haul optical systems, based on polarization multiplexed quadrature phase-shift keying (PM-QPSK) modulation format associated with coherent detection and digital signal processing (DSP), is mandatory. In fact, optical transport techniques enabling a per-channel bit rate beyond 100 Gbit/s have recently been the object of intensive R and D activities, aimed at both improving the spectral efficiency and lowering the cost per bit in fiber transmission systems. In this invited contribution, we review the different available options to scale the per-channel bit-rate to 400 Gbit/s and beyond, i.e. symbol-rate increase, use of higher-order quadrature amplitude modulation (QAM) modulation formats and use of super-channels with DSP-enabled spectral shaping and advanced multiplexing technologies. In this analysis, trade-offs of system reach, spectral efficiency and transceiver complexity are addressed. Besides scalability, next generation optical networks will require a high degree of flexibility in the transponders, which should be able to dynamically adapt the transmission rate and bandwidth occupancy to the light path characteristics. In order to increase the flexibility of these transponders (often referred to as "flexponders"), several advanced modulation techniques have recently been proposed, among which sub-carrier multiplexing, hybrid formats (over time, frequency and polarization), and constellation shaping. We review these techniques, highlighting their limits and potential in terms of performance, complexity and flexibility.

Optimal JPWL Forward Error Correction Rate Allocation for Robust JPEG 2000 Images and Video Streaming over Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Agueh, Max; Diouris, Jean-François; Diop, Magaye; Devaux, François-Olivier; De Vleeschouwer, Christophe; Macq, Benoit

2008-12-01

Based on the analysis of real mobile ad hoc network (MANET) traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC) rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS) to wireless clients is demonstrated.

Dynamical behavior of susceptible-infected-recovered-susceptible epidemic model on weighted networks

NASA Astrophysics Data System (ADS)

Wu, Qingchu; Zhang, Fei

2018-02-01

We study susceptible-infected-recovered-susceptible epidemic model in weighted, regular, and random complex networks. We institute a pairwise-type mathematical model with a general transmission rate to evaluate the influence of the link-weight distribution on the spreading process. Furthermore, we develop a dimensionality reduction approach to derive the condition for the contagion outbreak. Finally, we analyze the influence of the heterogeneity of weight distribution on the outbreak condition for the scenario with a linear transmission rate. Our theoretical analysis is in agreement with stochastic simulations, showing that the heterogeneity of link-weight distribution can have a significant effect on the epidemic dynamics.

Nilpotent singularities and dynamics in an SIR type of compartmental model with hospital resources

NASA Astrophysics Data System (ADS)

Shan, Chunhua; Yi, Yingfei; Zhu, Huaiping

2016-03-01

An SIR type of compartmental model with a standard incidence rate and a nonlinear recovery rate was formulated to study the impact of available resources of public health system especially the number of hospital beds. Cusp, focus and elliptic type of nilpotent singularities of codimension 3 are discovered and analyzed in this three dimensional model. Complex dynamics of disease transmission including multi-steady states and multi-periodicity are revealed by bifurcation analysis. Large-amplitude oscillations found in our model provide a more reasonable explanation for disease recurrence. With clinical data, our studies have practical implications for the prevention and control of infectious diseases.

Measuring the uncertainty of coupling

NASA Astrophysics Data System (ADS)

Zhao, Xiaojun; Shang, Pengjian

2015-06-01

A new information-theoretic measure, called coupling entropy, is proposed here to detect the causal links in complex systems by taking into account the inner composition alignment of temporal structure. It is a permutation-based asymmetric association measure to infer the uncertainty of coupling between two time series. The coupling entropy is found to be effective in the analysis of Hénon maps, where different noises are added to test its accuracy and sensitivity. The coupling entropy is also applied to analyze the relationship between unemployment rate and CPI change in the U.S., where the CPI change turns out to be the driving variable while the unemployment rate is the responding one.

Microcracking, microcrack-induced delamination, and longitudinal splitting of advanced composite structures

NASA Technical Reports Server (NTRS)

Nairn, John A.

1992-01-01

A combined analytical and experimental study was conducted to analyze microcracking, microcrack-induced delamination, and longitudinal splitting in polymer matrix composites. Strain energy release rates, calculated by a variational analysis, were used in a failure criterion to predict microcracking. Predictions and test results were compared for static, fatigue, and cyclic thermal loading. The longitudinal splitting analysis accounted for the effects of fiber bridging. Test data are analyzed and compared for longitudinal splitting and delamination under mixed-mode loading. This study emphasizes the importance of using fracture mechanics analyses to understand the complex failure processes that govern composite strength and life.

Diagnosis and treatment of posterior sacroiliac complex pain: a systematic review with comprehensive analysis of the published data.

PubMed

King, Wade; Ahmed, Shihab U; Baisden, Jamie; Patel, Nileshkumar; Kennedy, David J; Duszynski, Belinda; MacVicar, John

2015-02-01

To assess the evidence on the validity of sacral lateral branch blocks and the effectiveness of sacral lateral branch thermal radiofrequency neurotomy in managing sacroiliac complex pain. Systematic review with comprehensive analysis of all published data. Six reviewers searched the literature on sacral lateral branch interventions. Each assessed the methodologies of studies found and the quality of the evidence presented. The outcomes assessed were diagnostic validity and effectiveness of treatment for sacroiliac complex pain. The evidence found was appraised in accordance with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system of evaluating scientific evidence. The searches yielded two primary publications on sacral lateral branch blocks and 15 studies of the effectiveness of sacral lateral branch thermal radiofrequency neurotomy. One study showed multisite, multidepth sacral lateral branch blocks can anesthetize the posterior sacroiliac ligaments. Therapeutic studies show sacral lateral branch thermal radiofrequency neurotomy can relieve sacroiliac complex pain to some extent. The evidence of the validity of these blocks and the effectiveness of this treatment were rated as moderate in accordance with the GRADE system. The literature on sacral lateral branch interventions is sparse. One study demonstrates the face validity of multisite, multidepth sacral lateral branch blocks for diagnosis of posterior sacroiliac complex pain. Some evidence of moderate quality exists on therapeutic procedures, but it is insufficient to determine the indications and effectiveness of sacral lateral branch thermal radiofrequency neurotomy, and more research is required. Wiley Periodicals, Inc.

Exact solutions for oscillatory shear sweep behaviors of complex fluids from the Oldroyd 8-constant framework

NASA Astrophysics Data System (ADS)

Saengow, Chaimongkol; Giacomin, A. Jeffrey

2018-03-01

In this paper, we provide a new exact framework for analyzing the most commonly measured behaviors in large-amplitude oscillatory shear flow (LAOS), a popular flow for studying the nonlinear physics of complex fluids. Specifically, the strain rate sweep (also called the strain sweep) is used routinely to identify the onset of nonlinearity. By the strain rate sweep, we mean a sequence of LAOS experiments conducted at the same frequency, performed one after another, with increasing shear rate amplitude. In this paper, we give exact expressions for the nonlinear complex viscosity and the corresponding nonlinear complex normal stress coefficients, for the Oldroyd 8-constant framework for oscillatory shear sweeps. We choose the Oldroyd 8-constant framework for its rich diversity of popular special cases (we list 18 of these). We evaluate the Fourier integrals of our previous exact solution to get exact expressions for the real and imaginary parts of the complex viscosity, and for the complex normal stress coefficients, as functions of both test frequency and shear rate amplitude. We explore the role of infinite shear rate viscosity on strain rate sweep responses for the special case of the corotational Jeffreys fluid. We find that raising η∞ raises the real part of the complex viscosity and lowers the imaginary. In our worked examples, we thus first use the corotational Jeffreys fluid, and then, for greater accuracy, we use the Johnson-Segalman fluid, to describe the strain rate sweep response of molten atactic polystyrene. For our comparisons with data, we use the Spriggs relations to generalize the Oldroyd 8-constant framework to multimode. Our generalization yields unequivocally, a longest fluid relaxation time, used to assign Weissenberg and Deborah numbers to each oscillatory shear flow experiment. We then locate each experiment in the Pipkin space.

Effects of head-down bed rest on complex heart rate variability: Response to LBNP testing

NASA Technical Reports Server (NTRS)

Goldberger, Ary L.; Mietus, Joseph E.; Rigney, David R.; Wood, Margie L.; Fortney, Suzanne M.

1994-01-01

Head-down bed rest is used to model physiological changes during spaceflight. We postulated that bed rest would decrease the degree of complex physiological heart rate variability. We analyzed continuous heart rate data from digitized Holter recordings in eight healthy female volunteers (age 28-34 yr) who underwent a 13-day 6 deg head-down bed rest study with serial lower body negative pressure (LBNP) trials. Heart rate variability was measured on a 4-min data sets using conventional time and frequency domain measures as well as with a new measure of signal 'complexity' (approximate entropy). Data were obtained pre-bed rest (control), during bed rest (day 4 and day 9 or 11), and 2 days post-bed rest (recovery). Tolerance to LBNP was significantly reduced on both bed rest days vs. pre-bed rest. Heart rate variability was assessed at peak LBNP. Heart rate approximate entropy was significantly decreased at day 4 and day 9 or 11, returning toward normal during recovery. Heart rate standard deviation and the ratio of high- to low-power frequency did not change significantly. We conclude that short-term bed rest is associated with a decrease in the complex variability of heart rate during LBNP testing in healthy young adult women. Measurement of heart rate complexity, using a method derived from nonlinear dynamics ('chaos theory'), may provide a sensitive marker of this loss of physiological variability, complementing conventional time and frequency domain statistical measures.

Synthesis and characterization of carbazolide-based iridium PNP pincer complexes. Mechanistic and computational investigation of alkene hydrogenation: evidence for an Ir(III)/Ir(V)/Ir(III) catalytic cycle.

PubMed

Cheng, Chen; Kim, Bong Gon; Guironnet, Damien; Brookhart, Maurice; Guan, Changjian; Wang, David Y; Krogh-Jespersen, Karsten; Goldman, Alan S

2014-05-07

New carbazolide-based iridium pincer complexes ((carb)PNP)Ir(C2H4), 3a, and ((carb)PNP)Ir(H)2, 3b, have been prepared and characterized. The dihydride, 3b, reacts with ethylene to yield the cis-dihydride ethylene complex cis-((carb)PNP)Ir(C2H4)(H)2. Under ethylene this complex reacts slowly at 70 °C to yield ethane and the ethylene complex, 3a. Kinetic analysis establishes that the reaction rate is dependent on ethylene concentration and labeling studies show reversible migratory insertion to form an ethyl hydride complex prior to formation of 3a. Exposure of cis-((carb)PNP)Ir(C2H4)(H)2 to hydrogen results in very rapid formation of ethane and dihydride, 3b. DFT analysis suggests that ethane elimination from the ethyl hydride complex is assisted by ethylene through formation of ((carb)PNP)Ir(H)(Et)(C2H4) and by H2 through formation of ((carb)PNP)Ir(H)(Et)(H2). Elimination of ethane from Ir(III) complex ((carb)PNP)Ir(H)(Et)(H2) is calculated to proceed through an Ir(V) complex ((carb)PNP)Ir(H)3(Et) which reductively eliminates ethane with a very low barrier to return to the Ir(III) dihydride, 3b. Under catalytic hydrogenation conditions (C2H4/H2), cis-((carb)PNP)Ir(C2H4)(H)2 is the catalyst resting state, and the catalysis proceeds via an Ir(III)/Ir(V)/Ir(III) cycle. This is in sharp contrast to isoelectronic (PCP)Ir systems in which hydrogenation proceeds through an Ir(III)/Ir(I)/Ir(III) cycle. The basis for this remarkable difference is discussed.

A general computation model based on inverse analysis principle used for rheological analysis of W/O rapeseed and soybean oil emulsions

NASA Astrophysics Data System (ADS)

Vintila, Iuliana; Gavrus, Adinel

2017-10-01

The present research paper proposes the validation of a rigorous computation model used as a numerical tool to identify rheological behavior of complex emulsions W/O. Considering a three-dimensional description of a general viscoplastic flow it is detailed the thermo-mechanical equations used to identify fluid or soft material's rheological laws starting from global experimental measurements. Analyses are conducted for complex emulsions W/O having generally a Bingham behavior using the shear stress - strain rate dependency based on a power law and using an improved analytical model. Experimental results are investigated in case of rheological behavior for crude and refined rapeseed/soybean oils and four types of corresponding W/O emulsions using different physical-chemical composition. The rheological behavior model was correlated with the thermo-mechanical analysis of a plane-plane rheometer, oil content, chemical composition, particle size and emulsifier's concentration. The parameters of rheological laws describing the industrial oils and the W/O concentrated emulsions behavior were computed from estimated shear stresses using a non-linear regression technique and from experimental torques using the inverse analysis tool designed by A. Gavrus (1992-2000).

Elective ventilation for organ donation: law, policy and public ethics.

PubMed

Coggon, John

2013-03-01

This paper examines questions concerning elective ventilation, contextualised within English law and policy. It presents the general debate with reference both to the Exeter Protocol on elective ventilation, and the considerable developments in legal principle since the time that that protocol was declared to be unlawful. I distinguish different aspects of what might be labelled elective ventilation policies under the following four headings: 'basic elective ventilation'; 'epistemically complex elective ventilation'; 'practically complex elective ventilation'; and 'epistemically and practically complex elective ventilation'. I give a legal analysis of each. In concluding remarks on their potential practical viability, I emphasise the importance not just of ascertaining the legal and ethical acceptability of these and other forms of elective ventilation, but also of assessing their professional and political acceptability. This importance relates both to the successful implementation of the individual practices, and to guarding against possible harmful effects in the wider efforts to increase the rates of posthumous organ donation.

The "Chaos Theory" and nonlinear dynamics in heart rate variability analysis: does it work in short-time series in patients with coronary heart disease?

PubMed

Krstacic, Goran; Krstacic, Antonija; Smalcelj, Anton; Milicic, Davor; Jembrek-Gostovic, Mirjana

2007-04-01

Dynamic analysis techniques may quantify abnormalities in heart rate variability (HRV) based on nonlinear and fractal analysis (chaos theory). The article emphasizes clinical and prognostic significance of dynamic changes in short-time series applied on patients with coronary heart disease (CHD) during the exercise electrocardiograph (ECG) test. The subjects were included in the series after complete cardiovascular diagnostic data. Series of R-R and ST-T intervals were obtained from exercise ECG data after sampling digitally. The range rescaled analysis method determined the fractal dimension of the intervals. To quantify fractal long-range correlation's properties of heart rate variability, the detrended fluctuation analysis technique was used. Approximate entropy (ApEn) was applied to quantify the regularity and complexity of time series, as well as unpredictability of fluctuations in time series. It was found that the short-term fractal scaling exponent (alpha(1)) is significantly lower in patients with CHD (0.93 +/- 0.07 vs 1.09 +/- 0.04; P < 0.001). The patients with CHD had higher fractal dimension in each exercise test program separately, as well as in exercise program at all. ApEn was significant lower in CHD group in both RR and ST-T ECG intervals (P < 0.001). The nonlinear dynamic methods could have clinical and prognostic applicability also in short-time ECG series. Dynamic analysis based on chaos theory during the exercise ECG test point out the multifractal time series in CHD patients who loss normal fractal characteristics and regularity in HRV. Nonlinear analysis technique may complement traditional ECG analysis.

Solute-solvent complex switching dynamics of chloroform between acetone and dimethylsulfoxide-two-dimensional IR chemical exchange spectroscopy.

PubMed

Kwak, Kyungwon; Rosenfeld, Daniel E; Chung, Jean K; Fayer, Michael D

2008-11-06

Hydrogen bonds formed between C-H and various hydrogen bond acceptors play important roles in the structure of proteins and organic crystals, and the mechanisms of C-H bond cleavage reactions. Chloroform, a C-H hydrogen bond donor, can form weak hydrogen-bonded complexes with acetone and with dimethylsulfoxide (DMSO). When chloroform is dissolved in a mixed solvent consisting of acetone and DMSO, both types of hydrogen-bonded complexes exist. The two complexes, chloroform-acetone and chloroform-DMSO, are in equilibrium, and they rapidly interconvert by chloroform exchanging hydrogen bond acceptors. This fast hydrogen bond acceptor substitution reaction is probed using ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy. Deuterated chloroform is used in the experiments, and the 2D-IR spectrum of the C-D stretching mode is measured. The chemical exchange of the chloroform hydrogen bonding partners is tracked by observing the time-dependent growth of off-diagonal peaks in the 2D-IR spectra. The measured substitution rate is 1/30 ps for an acetone molecule to replace a DMSO molecule in a chloroform-DMSO complex and 1/45 ps for a DMSO molecule to replace an acetone molecule in a chloroform-acetone complex. Free chloroform exists in the mixed solvent, and it acts as a reactive intermediate in the substitution reaction, analogous to a SN1 type reaction. From the measured rates and the equilibrium concentrations of acetone and DMSO, the dissociation rates for the chloroform-DMSO and chloroform-acetone complexes are found to be 1/24 ps and 1/5.5 ps, respectively. The difference between the measured rate for the complete substitution reaction and the rate for complex dissociation corresponds to the diffusion limited rate. The estimated diffusion limited rate agrees well with the result from a Smoluchowski treatment of diffusive reactions.

[Laboratory surveillance for invasive meningococcal disease in Chile, 2006-2012].

PubMed

Araya, Pamela; Díaz, Janepsy; Seoane, Mabel; Fernández, Jorge; Terrazas, Solana; Canals, Andrea; Vaquero, Alejandra; Barra, Gisselle; Hormazábal, Juan C; Pidal, Paola; Valenzuela, M Teresa

2014-08-01

Laboratory surveillance of Invasive Meningococcal Disease (IMD) is performed by the Institute of Public Health of Chile. It confirms identification, classifies in serogroups and analyzes the genetic profiles of Neisseria meningitidis isolates from laboratories throughout the country. To show the results of this surveillance from 2006 to 2012. A descriptive data analysis of the confirmed cases of IMD and serological characterization, susceptibility and genetic profiles of the isolates. The analysis was disaggregated by serogroup, age and region. From 2006 to 2012, 486 isolates of N. meningitidis were confirmed. In 2011 a rise in IMD rates was observed due to an increase in W serogroup cases, mainly affecting children aged 5 years or less. Serogroup W became the most prevalent during 2012 (58.3%), replacing the historically prevalent serogroup B. Predominating strains belonged to ST-32 complex/ET-5 complex (40, 4% of strains) and ST-41/44 complex/ Lineage 3 (45, 9% of strains). Laboratory surveillance has allowed the early detection of increasing IMD caused by serogroup W, which is emergent in Chile. This information has reinforced the daily monitoring of new cases, in collaboration with all the clinical laboratories of the country.

Two-dimensional turbulent flow chromatography coupled on-line to liquid chromatography-mass spectrometry for solution-based ligand screening against multiple proteins.

PubMed

Zhou, Jian-Liang; An, Jing-Jing; Li, Ping; Li, Hui-Jun; Jiang, Yan; Cheng, Jie-Fei

2009-03-20

We present herein a novel bioseparation/chemical analysis strategy for protein-ligand screening and affinity ranking in compound mixtures, designed to increase screening rates and improve sensitivity and ruggedness in performance. The strategy is carried out by combining on-line two-dimensional turbulent flow chromatography (2D-TFC) with liquid chromatography-mass spectrometry (LC-MS), and accomplished through the following steps: (1) a reversed-phase TFC stage to separate the protein/ligand complex from the unbound free molecules, (2) an on-line dissociation process to release the bound ligands from the complexes, and (3) a second mixed-mode cation-exchange/reversed-phase TFC stage to trap the bound ligands and to remove the proteins and salts, followed by LC-MS analysis for identification and determination of the binding affinities. The technique can implement an ultra-fast isolation of protein/ligand complex with the retention time of a complex peak in about 5s, and on-line prepare the "clean" sample to be directly compatible with the LC-MS analysis. The improvement in performance of this 2D-TFC/LC-MS approach over the conventional approach has been demonstrated by determining affinity-selected ligands of the target proteins acetylcholinesterase and butyrylcholinesterase from a small library with known binding affinities and a steroidal alkaloid library composed of structurally similar compounds. Our results show that 2D-TFC/LC-MS is a generic and efficient tool for high-throughput screening of ligands with low-to-high binding affinities, and structure-activity relationship evaluation.

Analysis of spontaneous MEG activity in mild cognitive impairment and Alzheimer's disease using spectral entropies and statistical complexity measures

NASA Astrophysics Data System (ADS)

Bruña, Ricardo; Poza, Jesús; Gómez, Carlos; García, María; Fernández, Alberto; Hornero, Roberto

2012-06-01

Alzheimer's disease (AD) is the most common cause of dementia. Over the last few years, a considerable effort has been devoted to exploring new biomarkers. Nevertheless, a better understanding of brain dynamics is still required to optimize therapeutic strategies. In this regard, the characterization of mild cognitive impairment (MCI) is crucial, due to the high conversion rate from MCI to AD. However, only a few studies have focused on the analysis of magnetoencephalographic (MEG) rhythms to characterize AD and MCI. In this study, we assess the ability of several parameters derived from information theory to describe spontaneous MEG activity from 36 AD patients, 18 MCI subjects and 26 controls. Three entropies (Shannon, Tsallis and Rényi entropies), one disequilibrium measure (based on Euclidean distance ED) and three statistical complexities (based on Lopez Ruiz-Mancini-Calbet complexity LMC) were used to estimate the irregularity and statistical complexity of MEG activity. Statistically significant differences between AD patients and controls were obtained with all parameters (p < 0.01). In addition, statistically significant differences between MCI subjects and controls were achieved by ED and LMC (p < 0.05). In order to assess the diagnostic ability of the parameters, a linear discriminant analysis with a leave-one-out cross-validation procedure was applied. The accuracies reached 83.9% and 65.9% to discriminate AD and MCI subjects from controls, respectively. Our findings suggest that MCI subjects exhibit an intermediate pattern of abnormalities between normal aging and AD. Furthermore, the proposed parameters provide a new description of brain dynamics in AD and MCI.

Communication patterns in a psychotherapy following traumatic brain injury: A quantitative case study based on symbolic dynamics

PubMed Central

2011-01-01

Background The role of psychotherapy in the treatment of traumatic brain injury is receiving increased attention. The evaluation of psychotherapy with these patients has been conducted largely in the absence of quantitative data concerning the therapy itself. Quantitative methods for characterizing the sequence-sensitive structure of patient-therapist communication are now being developed with the objective of improving the effectiveness of psychotherapy following traumatic brain injury. Methods The content of three therapy session transcripts (sessions were separated by four months) obtained from a patient with a history of several motor vehicle accidents who was receiving dialectical behavior therapy was scored and analyzed using methods derived from the mathematical theory of symbolic dynamics. Results The analysis of symbol frequencies was largely uninformative. When repeated triples were examined a marked pattern of change in content was observed over the three sessions. The context free grammar complexity and the Lempel-Ziv complexity were calculated for each therapy session. For both measures, the rate of complexity generation, expressed as bits per minute, increased longitudinally during the course of therapy. The between-session increases in complexity generation rates are consistent with calculations of mutual information. Taken together these results indicate that there was a quantifiable increase in the variability of patient-therapist verbal behavior during the course of therapy. Comparison of complexity values against values obtained from equiprobable random surrogates established the presence of a nonrandom structure in patient-therapist dialog (P = .002). Conclusions While recognizing that only limited conclusions can be based on a case history, it can be noted that these quantitative observations are consistent with qualitative clinical observations of increases in the flexibility of discourse during therapy. These procedures can be of particular value in the examination of therapies following traumatic brain injury because, in some presentations, these therapies are complicated by deficits that result in subtle distortions of language that produce significant post-injury social impairment. Independently of the mathematical analysis applied to the investigation of therapy-generated symbol sequences, our experience suggests that the procedures presented here are of value in training therapists. PMID:21794113

Gas-Driven Fracturing of Saturated Granular Media

NASA Astrophysics Data System (ADS)

Campbell, James M.; Ozturk, Deren; Sandnes, Bjørnar

2017-12-01

Multiphase flows in deformable porous materials are important in numerous geological and geotechnical applications; however, the complex flow behavior makes subsurface transport processes difficult to control—or even characterize. Here, we study gas-driven (pneumatic) fracturing of a wet unconsolidated granular packing confined in a Hele-Shaw cell, and we present an in-depth analysis of both pore-scale phenomena and large-scale pattern formation. The process is governed by a complex interplay among pressure, capillary, frictional, and viscous forces. At low gas-injection rates, fractures grow in a stick-slip fashion and branch out to form a simply connected network. We observe the emergence of a characteristic length scale—the separation distance between fracture branches—creating an apparent uniform spatial fracture density. We conclude that the well-defined separation distance is the result of local compaction fronts surrounding fractures and keeping them apart. A scaling argument is presented that predicts fracture density as a function of granular friction, grain size, and capillary interactions. We study the influence of the gas-injection rate and find that the system undergoes a fluidization transition above a critical injection rate, resulting in directional growth of the fractures, and a fracture density that increases with an increasing rate. A dimensionless fluidization number F is defined as the ratio of viscous to frictional forces, and our experiments reveal a frictional regime for F <1 characterized by stick-slip, rate-independent growth, with a transition to a viscous regime (F >1 ) characterized by continuous growth in several fracture branches simultaneously.

Fluorescent recovery after photobleaching (FRAP) analysis of nuclear export rates identifies intrinsic features of nucleocytoplasmic transport.

PubMed

Cardarelli, Francesco; Tosti, Luca; Serresi, Michela; Beltram, Fabio; Bizzarri, Ranieri

2012-02-17

A quantitative description of carrier-mediated nuclear export in live cells is presented. To this end, we fused a prototypical leucine-rich nuclear export signal (NES) to GFP as a cargo model and expressed the fluorescent chimera in live CHO-K1 cells. By modeling FRAP data, we calculate the NES affinity for the export machinery and the maximum rate of nuclear export achievable at saturation of endogenous carriers. The measured active-export time through the Nuclear Pore Complex (NPC) is 18 ms, remarkably similar to the previously determined active-import rate. Also, our results reveal that active export/import and active export/passive diffusion fluxes are uncoupled, thus complementing previous reports on active import/passive diffusion uncoupling. These findings suggest differential gating at the NPC level.

High frame-rate computational ghost imaging system using an optical fiber phased array and a low-pixel APD array.

PubMed

Liu, Chunbo; Chen, Jingqiu; Liu, Jiaxin; Han, Xiang'e

2018-04-16

To obtain a high imaging frame rate, a computational ghost imaging system scheme is proposed based on optical fiber phased array (OFPA). Through high-speed electro-optic modulators, the randomly modulated OFPA can provide much faster speckle projection, which can be precomputed according to the geometry of the fiber array and the known phases for modulation. Receiving the signal light with a low-pixel APD array can effectively decrease the requirement on sampling quantity and computation complexity owing to the reduced data dimensionality while avoiding the image aliasing due to the spatial periodicity of the speckles. The results of analysis and simulation show that the frame rate of the proposed imaging system can be significantly improved compared with traditional systems.

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at √{s}=8 TeV with the ATLAS detector

NASA Astrophysics Data System (ADS)

Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S. H.; AbouZeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adamczyk, L.; Adelman, J.; Adersberger, M.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agheorghiesei, C.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akatsuka, S.; Akerstedt, H.; Åkesson, T. P. A.; Akilli, E.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albicocco, P.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alshehri, A. A.; Alstaty, M. I.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Angerami, A.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antel, C.; Antonelli, M.; Antonov, A.; Antrim, D. J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Araujo Ferraz, V.; Arce, A. T. H.; Ardell, R. E.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagnaia, P.; Bahrasemani, H.; Baines, J. T.; Bajic, M.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisits, M.-S.; Barkeloo, J. T.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska-Blenessy, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beermann, T. A.; Begalli, M.; Begel, M.; Behr, J. K.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernardi, G.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethani, A.; Bethke, S.; Bevan, A. J.; Beyer, J.; Bianchi, R. M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; Bilbao De Mendizabal, J.; Billoud, T. R. V.; Bilokon, H.; Bindi, M.; Bingul, A.; Bini, C.; Biondi, S.; Bisanz, T.; Bittrich, C.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blair, R. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blue, A.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bokan, P.; Bold, T.; Boldyrev, A. S.; Bolz, A. E.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Boscherini, D.; Bosman, M.; Bossio Sola, J. D.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Briglin, D. L.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruni, L. S.; Brunt, BH; Bruschi, M.; Bruscino, N.; Bryant, P.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Buehrer, F.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burch, T. J.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burger, A. M.; Burghgrave, B.; Burka, K.; Burke, S.; Burmeister, I.; Burr, J. T. P.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Callea, G.; Caloba, L. P.; Calvente Lopez, S.; Calvet, D.; Calvet, S.; Calvet, T. P.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Camincher, C.; Campana, S.; Campanelli, M.; Camplani, A.; Campoverde, A.; Canale, V.; Cano Bret, M.; Cantero, J.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, I.; Carli, T.; Carlino, G.; Carlson, B. T.; Carminati, L.; Carney, R. M. D.; Caron, S.; Carquin, E.; Carrá, S.; Carrillo-Montoya, G. D.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Casper, D. W.; Castelijn, R.; Castillo Gimenez, V.; Castro, N. F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavallaro, E.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Celebi, E.; Ceradini, F.; Cerda Alberich, L.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, S. K.; Chan, W. S.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chau, C. C.; Chavez Barajas, C. A.; Che, S.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, H. 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A.; Van Den Wollenberg, W.; van der Graaf, H.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varni, C.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vasquez, G. A.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veeraraghavan, V.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, A. T.; Vermeulen, J. C.; Vetterli, M. C.; Viaux Maira, N.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vishwakarma, A.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vogel, M.; Vokac, P.; Volpi, G.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Wagner, W.; Wagner-Kuhr, J.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, Q.; Wang, R.; Wang, S. M.; Wang, T.; Wang, W.; Wang, W.; Wang, Z.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, A. F.; Webb, S.; Weber, M. S.; Weber, S. W.; Weber, S. A.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weirich, M.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M. D.; Werner, P.; Wessels, M.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A. S.; White, A.; White, M. J.; White, R.; Whiteson, D.; Whitmore, B. W.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilk, F.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, J. A.; Wingerter-Seez, I.; Winkels, E.; Winklmeier, F.; Winston, O. J.; Winter, B. T.; Wittgen, M.; Wobisch, M.; Wolf, T. M. H.; Wolff, R.; Wolter, M. W.; Wolters, H.; Wong, V. W. S.; Worm, S. D.; Wosiek, B. K.; Wotschack, J.; Wozniak, K. W.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xi, Z.; Xia, L.; Xu, D.; Xu, L.; Xu, T.; Yabsley, B.; Yacoob, S.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamatani, M.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yigitbasi, E.; Yildirim, E.; Yorita, K.; Yoshihara, K.; Young, C.; Young, C. J. S.; Yu, J.; Yu, J.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zacharis, G.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanzi, D.; Zeitnitz, C.; Zemaityte, G.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, L.; Zhang, M.; Zhang, P.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Y.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, M.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zou, R.; zur Nedden, M.; Zwalinski, L.

2017-12-01

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. An analysis of a triple-differential decay rate in t-channel production is used to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb-1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fraction of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ - = 0.002 π + 0.017 π + 0.016 π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [ g R/V L ∈ [-0.12, 0.17] and Im [ g R/VL ∈ [-0.07, 0.06]. Constraints are also placed on the ratios | V R/ V L| and | g L/ V L|. In addition, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model. [Figure not available: see fulltext.

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at s=8$$ \\sqrt{s}=8 $$ TeV with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-12-04

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. We use an analysis of a triple-differential decay rate in t-channel production to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fractionmore » of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ -= 0.002π + 0.017π + 0.016π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [g R/V L ϵ [-0.12, 0.17] and Im [g R/V L ϵ [-0.07, 0.06]. Constraints are also placed on the ratios |V R/V L| and |g L/V L|. Additionally, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model.« less

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at $$ \\sqrt{s}=8 $$ TeV with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-12-04

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. We use an analysis of a triple-differential decay rate in t-channel production to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fractionmore » of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ -= 0.002π + 0.017π + 0.016π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [g R/V L ϵ [-0.12, 0.17] and Im [g R/V L ϵ [-0.07, 0.06]. Constraints are also placed on the ratios |V R/V L| and |g L/V L|. Additionally, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model.« less

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at s=8$$ \\sqrt{s}=8 $$ TeV with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. We use an analysis of a triple-differential decay rate in t-channel production to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fractionmore » of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ -= 0.002π + 0.017π + 0.016π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [g R/V L ϵ [-0.12, 0.17] and Im [g R/V L ϵ [-0.07, 0.06]. Constraints are also placed on the ratios |V R/V L| and |g L/V L|. Additionally, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model.« less

Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at $$ \\sqrt{s}=8 $$ TeV with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

The electroweak production and subsequent decay of single top quarks in the t-channel is determined by the properties of the Wtb vertex, which can be described by the complex parameters of an effective Lagrangian. We use an analysis of a triple-differential decay rate in t-channel production to simultaneously determine five generalised helicity fractions and phases, as well as the polarisation of the produced top quark. The complex parameters are then constrained. This analysis is based on 20.2 fb -1 of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the ATLAS detector at the LHC. The fractionmore » of decays containing transversely polarised W bosons is measured to be f 1 = 0.30 ± 0.05. The phase between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be δ -= 0.002π + 0.017π + 0.016π , giving no indication of CP violation. The fractions of longitudinal or transverse W bosons accompanied by right-handed b-quarks are also constrained. Based on these measurements, limits are placed at 95% CL on the ratio of the complex coupling parameters Re [g R/V L ϵ [-0.12, 0.17] and Im [g R/V L ϵ [-0.07, 0.06]. Constraints are also placed on the ratios |V R/V L| and |g L/V L|. Additionally, the polarisation of single top quarks in the t-channel is constrained to be P > 0.72 (95% CL). None of the above measurements make assumptions about the value of any of the other parameters or couplings and all of them are in agreement with the Standard Model.« less

Quantitative chemical exchange saturation transfer (qCEST) MRI--RF spillover effect-corrected omega plot for simultaneous determination of labile proton fraction ratio and exchange rate.

PubMed

Sun, Phillip Zhe; Wang, Yu; Dai, ZhuoZhi; Xiao, Gang; Wu, Renhua

2014-01-01

Chemical exchange saturation transfer (CEST) MRI is sensitive to dilute proteins and peptides as well as microenvironmental properties. However, the complexity of the CEST MRI effect, which varies with the labile proton content, exchange rate and experimental conditions, underscores the need for developing quantitative CEST (qCEST) analysis. Towards this goal, it has been shown that omega plot is capable of quantifying paramagnetic CEST MRI. However, the use of the omega plot is somewhat limited for diamagnetic CEST (DIACEST) MRI because it is more susceptible to direct radio frequency (RF) saturation (spillover) owing to the relatively small chemical shift. Recently, it has been found that, for dilute DIACEST agents that undergo slow to intermediate chemical exchange, the spillover effect varies little with the labile proton ratio and exchange rate. Therefore, we postulated that the omega plot analysis can be improved if RF spillover effect could be estimated and taken into account. Specifically, simulation showed that both labile proton ratio and exchange rate derived using the spillover effect-corrected omega plot were in good agreement with simulated values. In addition, the modified omega plot was confirmed experimentally, and we showed that the derived labile proton ratio increased linearly with creatine concentration (p < 0.01), with little difference in their exchange rate (p = 0.32). In summary, our study extends the conventional omega plot for quantitative analysis of DIACEST MRI. Copyright © 2014 John Wiley & Sons, Ltd.

Factor Analysis of Computer-Based Multidimensional Aptitude Battery-Second Edition Intelligence Testing from Rated U.S. Air Force Pilots

DTIC Science & Technology

2012-09-01

intelligence continues to evolve as attention to cognitive processes and mechanisms, a deeper understanding of related issues, and new theories ...hierarchical models that describe specific abilities arranged according to increasing specificity and developmental complexity [6-8]. Theories have also...persistence) not tapped directly by existing measures of intellectual ability. Wechsler’s theory of intelligence is central to the development of the mostly

Combat Casualties Undergoing Lifesaving Interventions Have Decreased Heart Rate Complexity at Multiple Time Scales

DTIC Science & Technology

2013-01-01

almost half of the cases, related to delays in hemorrhage control during transportation or in resuscitation efforts. Earlier detection of hemorrhagic...restored to normal values with fluid resuscitation [311. On further analysis, we found that SampEn retained its ability to discriminate survivors from...information about HR dynamics in the neonatal ICU setting. They have developed a real time index, termed HR characteristics, which takes into

Aircraft Flight Safety: A Bibliography. (La Securite en Vol: Une Bibliographie)

DTIC Science & Technology

1993-12-01

having been installed 93A27135 with the wrong bolts during maintenance. An DRURY , COLIN G. (New York State Univ., analysis of the complex events...accident rates. The REJMAN, MICHAEL H.; SYMONDS, COLIN J.; 0 conclusion made is that, Judgement Training has SHEPHERD, ERIC W. (City of London Polytech...from training 0 software to controlled dynamic simulations 93N19702 conducted with mockups, tooling, and subjects in SYMONDS, COLIN J.; REJMAN

Flow injection method for sulphide determination using an organic mercury compound

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

Yaqoob, M.; Anwar, M.; Masood, A.S.

1991-04-01

A simple flow injection analysis method is described for the determination of soluble sulfide, based on the complexation of sulfide with p-hydroxymercurbenzoic acid, in the presence of dithizone used as an indicator. The reaction is very rapid, with a sampling rate of 90/hr. and requires a very short length post injection reaction coil. The detection limit and precision are 0.01 mM and 0.7%, respectively.

Iterative Calibration: A Novel Approach for Calibrating the Molecular Clock Using Complex Geological Events.

PubMed

Loeza-Quintana, Tzitziki; Adamowicz, Sarah J

2018-02-01

During the past 50 years, the molecular clock has become one of the main tools for providing a time scale for the history of life. In the era of robust molecular evolutionary analysis, clock calibration is still one of the most basic steps needing attention. When fossil records are limited, well-dated geological events are the main resource for calibration. However, biogeographic calibrations have often been used in a simplistic manner, for example assuming simultaneous vicariant divergence of multiple sister lineages. Here, we propose a novel iterative calibration approach to define the most appropriate calibration date by seeking congruence between the dates assigned to multiple allopatric divergences and the geological history. Exploring patterns of molecular divergence in 16 trans-Bering sister clades of echinoderms, we demonstrate that the iterative calibration is predominantly advantageous when using complex geological or climatological events-such as the opening/reclosure of the Bering Strait-providing a powerful tool for clock dating that can be applied to other biogeographic calibration systems and further taxa. Using Bayesian analysis, we observed that evolutionary rate variability in the COI-5P gene is generally distributed in a clock-like fashion for Northern echinoderms. The results reveal a large range of genetic divergences, consistent with multiple pulses of trans-Bering migrations. A resulting rate of 2.8% pairwise Kimura-2-parameter sequence divergence per million years is suggested for the COI-5P gene in Northern echinoderms. Given that molecular rates may vary across latitudes and taxa, this study provides a new context for dating the evolutionary history of Arctic marine life.

Rate-loss analysis of an efficient quantum repeater architecture

NASA Astrophysics Data System (ADS)

Guha, Saikat; Krovi, Hari; Fuchs, Christopher A.; Dutton, Zachary; Slater, Joshua A.; Simon, Christoph; Tittel, Wolfgang

2015-08-01

We analyze an entanglement-based quantum key distribution (QKD) architecture that uses a linear chain of quantum repeaters employing photon-pair sources, spectral-multiplexing, linear-optic Bell-state measurements, multimode quantum memories, and classical-only error correction. Assuming perfect sources, we find an exact expression for the secret-key rate, and an analytical description of how errors propagate through the repeater chain, as a function of various loss-and-noise parameters of the devices. We show via an explicit analytical calculation, which separately addresses the effects of the principle nonidealities, that this scheme achieves a secret-key rate that surpasses the Takeoka-Guha-Wilde bound—a recently found fundamental limit to the rate-vs-loss scaling achievable by any QKD protocol over a direct optical link—thereby providing one of the first rigorous proofs of the efficacy of a repeater protocol. We explicitly calculate the end-to-end shared noisy quantum state generated by the repeater chain, which could be useful for analyzing the performance of other non-QKD quantum protocols that require establishing long-distance entanglement. We evaluate that shared state's fidelity and the achievable entanglement-distillation rate, as a function of the number of repeater nodes, total range, and various loss-and-noise parameters of the system. We extend our theoretical analysis to encompass sources with nonzero two-pair-emission probability, using an efficient exact numerical evaluation of the quantum state propagation and measurements. We expect our results to spur formal rate-loss analysis of other repeater protocols and also to provide useful abstractions to seed analyses of quantum networks of complex topologies.

Executive Function and Remission of Geriatric Depression: The Role of Semantic Strategy

PubMed Central

Morimoto, Sarah Shizuko; Gunning, Faith M.; Murphy, Christopher F.; Kanellopoulos, Dora; Kelly, Robert E.; Alexopoulos, George S.

2013-01-01

BACKGROUND This study tested the hypothesis that use of semantic organizational strategy in approaching the Mattis Dementia Rating Scale (MDRS) Complex Verbal Initiation Perseveration (I/P) task, a test of semantic fluency, is the function specifically associated with remission of late-life depression. METHOD 70 elders with major depression participated in a 12-week escitalopram treatment trial. Neuropsychological performance was assessed at baseline after a 2-week drug washout period. Patients with a Hamilton Depression Rating Scale Score less than or equal to 7 for two consecutive weeks and who no longer met DSM-IV criteria were considered to be remitted. Cox proportional hazards survival analysis was used to examine the relationship between subtests of the I/P, other neuropsychological domains and remission rate. Participants’ performance on the CV I/P was coded for perseverations, and use of semantic strategy. RESULTS The relationship of performance on the Complex Verbal I/P and remission rate was significant. No other subtest of the MDRS I/P evidenced this association. There was no significant relationship of speed, confrontation naming, verbal memory or perseveration with remission rate. Remitters’ use of verbal strategy was significantly greater than non-remitters. CONCLUSIONS Geriatric depressed patients who showed decrements in performance on a semantic fluency task showed poorer remission rates than those who showed adequate performance on this measure. Executive impairment in verbal strategy explained performance. This finding supports the concept that executive functioning exerts a “top down” effect on other basic cognitive processes, perhaps as a result of frontostriatal network dysfunction implicated in geriatric depression. PMID:20808124

VLSI (Very Large Scale Integrated Circuits) Device Reliability Models.

DTIC Science & Technology

1984-12-01

CIRCUIT COMPLEXITY FAILURE RATES FOR... A- 40 MOS SSI/MSI DEVICES IN FAILURE PER 106 HOURS TABLE 5.1.2.5-19: C1 AND C2 CIRCUIT COMPLEXITY FAILURE RATES FOR...A- 40 MOS SSI/MSI DEVICES IN FAILURE PER 106 HOURS TABLE 5.1.2.5-19: Cl AND C2 CIRCUIT COMPLEXITY FAILURE RATES FOR... A-41 LINEAR DEVICES IN...19 National Semiconductor 20 Nitron 21 Raytheon 22 Sprague 23 Synertek 24 Teledyne Crystalonics 25 TRW Semiconductor 26 Zilog The following companies

Dose rate prediction methodology for remote handled transuranic waste workers at the waste isolation pilot plant.

PubMed

Hayes, Robert

2002-10-01

An approach is described for estimating future dose rates to Waste Isolation Pilot Plant workers processing remote handled transuranic waste. The waste streams will come from the entire U.S. Department of Energy complex and can take on virtually any form found from the processing sequences for defense-related production, radiochemistry, activation and related work. For this reason, the average waste matrix from all generator sites is used to estimate the average radiation fields over the facility lifetime. Innovative new techniques were applied to estimate expected radiation fields. Non-linear curve fitting techniques were used to predict exposure rate profiles from cylindrical sources using closed form equations for lines and disks. This information becomes the basis for Safety Analysis Report dose rate estimates and for present and future ALARA design reviews when attempts are made to reduce worker doses.

Binding proteins enhance specific uptake rate by increasing the substrate-transporter encounter rate.

PubMed

Bosdriesz, Evert; Magnúsdóttir, Stefanía; Bruggeman, Frank J; Teusink, Bas; Molenaar, Douwe

2015-06-01

Microorganisms rely on binding-protein assisted, active transport systems to scavenge for scarce nutrients. Several advantages of using binding proteins in such uptake systems have been proposed. However, a systematic, rigorous and quantitative analysis of the function of binding proteins is lacking. By combining knowledge of selection pressure and physiochemical constraints, we derive kinetic, thermodynamic, and stoichiometric properties of binding-protein dependent transport systems that enable a maximal import activity per amount of transporter. Under the hypothesis that this maximal specific activity of the transport complex is the selection objective, binding protein concentrations should exceed the concentration of both the scarce nutrient and the transporter. This increases the encounter rate of transporter with loaded binding protein at low substrate concentrations, thereby enhancing the affinity and specific uptake rate. These predictions are experimentally testable, and a number of observations confirm them. © 2015 FEBS.

Rate Dependence of Elementary Rearrangements and Spatiotemporal Correlations in the 3D Flow of Soft Solids

NASA Astrophysics Data System (ADS)

Vasisht, Vishwas V.; Dutta, Sudeep K.; Del Gado, Emanuela; Blair, Daniel L.

2018-01-01

We use a combination of confocal microscopy, rheology, and molecular dynamics simulations to investigate jammed emulsions under shear, by analyzing the 3D droplets rearrangements in the shear frame. Our quantitative analysis of local dynamics reveals elementary nonaffine rearrangements that underlie the onset of the flow at small strains. We find that the mechanism of unjamming and the upturn in the material flow curve are associated to a qualitative change in spatiotemporal correlations of such rearrangements with the applied shear rate. At high shear rates, droplet clusters follow coordinated, stringlike motion. Conversely, at low shear rates, the elementary nonaffine rearrangements exhibit longer-ranged correlations, with complex spatiotemporal patterns. The 3D microscopic details provide novel insights into the specific features of the material flow curve, common to a large class of technologically relevant soft disordered solids and new fundamental ingredients for constitutive models.

Numerical analysis of stress effects on Frank loop evolution during irradiation in austenitic Fe&z.sbnd;Cr&z.sbnd;Ni alloy

NASA Astrophysics Data System (ADS)

Tanigawa, Hiroyasu; Katoh, Yutai; Kohyama, Akira

1995-08-01

Effects of applied stress on early stages of interstitial type Frank loop evolution were investigated by both numerical calculation and irradiation experiments. The final objective of this research is to propose a comprehensive model of complex stress effects on microstructural evolution under various conditions. In the experimental part of this work, the microstructural analysis revealed that the differences in resolved normal stress caused those in the nucleation rates of Frank loops on {111} crystallographic family planes, and that with increasing external applied stress the total nucleation rate of Frank loops was increased. A numerical calculation was carried out primarily to evaluate the validity of models of stress effects on nucleation processes of Frank loop evolution. The calculation stands on rate equuations which describe evolution of point defects, small points defect clusters and Frank loops. The rate equations of Frank loop evolution were formulated for {111} planes, considering effects of resolved normal stress to clustering processes of small point defects and growth processes of Frank loops, separately. The experimental results and the predictions from the numerical calculation qualitatively coincided well with each other.

Do numerical rating scales and the Roland-Morris Disability Questionnaire capture changes that are meaningful to patients with persistent back pain?

PubMed

Hush, Julia M; Refshauge, Kathryn M; Sullivan, Gerard; De Souza, Lorraine; McAuley, James H

2010-07-01

To investigate patients' views about two common outcome measures used for back pain: Numerical Rating Scales for pain and the Roland-Morris Disability Questionnaire. Thirty-six working adults who had previously sought primary care for back pain and who could speak and read English. Eight focus groups were conducted to explore participants' views about the 11-point Numerical Rating Scales and the 24-item Roland-Morris Disability Questionnaire. Each group was led by a facilitator and an interview topic guide was used. Audio recordings of focus groups were transcribed verbatim. Framework analysis was used to chart participants' views and an interpretive analysis performed to explain the findings. Participants reported that neither the Roland-Morris nor the Numerical Rating Scales captured the complex personal experience of pain or relevant changes in their condition. The time-frame of assessment was identified as particularly problematic and the Roland-Morris did not capture relevant functional domains. This study provides empirical data that working adults with persistent back pain consider these clinical outcome measures largely inadequate. These measures currently used for back pain may contribute to misleading conclusions about treatment efficacy and patient recovery.

A retrospective analysis of antimicrobial resistance in bacterial pathogens in an equine hospital (2012-2015).

PubMed

van Spijk, J N; Schmitt, S; Fürst, A E; Schoster, A

2016-06-01

Antimicrobial resistance has become an important concern in veterinary medicine. The aim of this study was to describe the rate of antimicrobial resistance in common equine pathogens and to determine the occurrence of multidrug-resistant isolates. A retrospective analysis of all susceptibility testing results from bacterial pathogens cultured from horses at the University of Zurich Equine Hospital (2012-2015) was performed. Strains exhibiting resistance to 3 or more antimicrobial categories were defined as multidrug-resistant. Susceptibility results from 303 bacterial pathogens were analyzed, most commonly Escherichia coli (60/303, 20%) and Staphylococcus aureus (40/303, 13%). High rates of acquired resistance against commonly used antimicrobials were found in most of the frequently isolated equine pathogens. The highest rate of multidrug resistance was found in isolates of Acinetobacter baumannii (23/24, 96%), followed by Enterobacter cloacae complex (24/28, 86%) and Escherichia coli (48/60, 80%). Overall, 60% of Escherichia coli isolates were phenotypically ESBL-producing and 68% of Staphylococcus spp. were phenotypically methicillin-resistant. High rates of acquired antimicrobial resistance towards commonly used antibiotics are concerning and underline the importance of individual bacteriological and antimicrobial susceptibility testing to guide antimicrobial therapy. Minimizing and optimizing antimicrobial therapy in horses is needed.

A Large Deviations Analysis of Certain Qualitative Properties of Parallel Tempering and Infinite Swapping Algorithms

DOE PAGES

Doll, J.; Dupuis, P.; Nyquist, P.

2017-02-08

Parallel tempering, or replica exchange, is a popular method for simulating complex systems. The idea is to run parallel simulations at different temperatures, and at a given swap rate exchange configurations between the parallel simulations. From the perspective of large deviations it is optimal to let the swap rate tend to infinity and it is possible to construct a corresponding simulation scheme, known as infinite swapping. In this paper we propose a novel use of large deviations for empirical measures for a more detailed analysis of the infinite swapping limit in the setting of continuous time jump Markov processes. Usingmore » the large deviations rate function and associated stochastic control problems we consider a diagnostic based on temperature assignments, which can be easily computed during a simulation. We show that the convergence of this diagnostic to its a priori known limit is a necessary condition for the convergence of infinite swapping. The rate function is also used to investigate the impact of asymmetries in the underlying potential landscape, and where in the state space poor sampling is most likely to occur.« less

Grain-Size Based Additivity Models for Scaling Multi-rate Uranyl Surface Complexation in Subsurface Sediments

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

Zhang, Xiaoying; Liu, Chongxuan; Hu, Bill X.

This study statistically analyzed a grain-size based additivity model that has been proposed to scale reaction rates and parameters from laboratory to field. The additivity model assumed that reaction properties in a sediment including surface area, reactive site concentration, reaction rate, and extent can be predicted from field-scale grain size distribution by linearly adding reaction properties for individual grain size fractions. This study focused on the statistical analysis of the additivity model with respect to reaction rate constants using multi-rate uranyl (U(VI)) surface complexation reactions in a contaminated sediment as an example. Experimental data of rate-limited U(VI) desorption in amore » stirred flow-cell reactor were used to estimate the statistical properties of multi-rate parameters for individual grain size fractions. The statistical properties of the rate constants for the individual grain size fractions were then used to analyze the statistical properties of the additivity model to predict rate-limited U(VI) desorption in the composite sediment, and to evaluate the relative importance of individual grain size fractions to the overall U(VI) desorption. The result indicated that the additivity model provided a good prediction of the U(VI) desorption in the composite sediment. However, the rate constants were not directly scalable using the additivity model, and U(VI) desorption in individual grain size fractions have to be simulated in order to apply the additivity model. An approximate additivity model for directly scaling rate constants was subsequently proposed and evaluated. The result found that the approximate model provided a good prediction of the experimental results within statistical uncertainty. This study also found that a gravel size fraction (2-8mm), which is often ignored in modeling U(VI) sorption and desorption, is statistically significant to the U(VI) desorption in the sediment.« less

Modelling effects of diquat under realistic exposure patterns in genetically differentiated populations of the gastropod Lymnaea stagnalis

PubMed Central

Ducrot, Virginie; Péry, Alexandre R. R.; Lagadic, Laurent

2010-01-01

Pesticide use leads to complex exposure and response patterns in non-target aquatic species, so that the analysis of data from standard toxicity tests may result in unrealistic risk forecasts. Developing models that are able to capture such complexity from toxicity test data is thus a crucial issue for pesticide risk assessment. In this study, freshwater snails from two genetically differentiated populations of Lymnaea stagnalis were exposed to repeated acute applications of environmentally realistic concentrations of the herbicide diquat, from the embryo to the adult stage. Hatching rate, embryonic development duration, juvenile mortality, feeding rate and age at first spawning were investigated during both exposure and recovery periods. Effects of diquat on mortality were analysed using a threshold hazard model accounting for time-varying herbicide concentrations. All endpoints were significantly impaired at diquat environmental concentrations in both populations. Snail evolutionary history had no significant impact on their sensitivity and responsiveness to diquat, whereas food acted as a modulating factor of toxicant-induced mortality. The time course of effects was adequately described by the model, which thus appears suitable to analyse long-term effects of complex exposure patterns based upon full life cycle experiment data. Obtained model outputs (e.g. no-effect concentrations) could be directly used for chemical risk assessment. PMID:20921047

Modelling effects of diquat under realistic exposure patterns in genetically differentiated populations of the gastropod Lymnaea stagnalis.

PubMed

Ducrot, Virginie; Péry, Alexandre R R; Lagadic, Laurent

2010-11-12

Pesticide use leads to complex exposure and response patterns in non-target aquatic species, so that the analysis of data from standard toxicity tests may result in unrealistic risk forecasts. Developing models that are able to capture such complexity from toxicity test data is thus a crucial issue for pesticide risk assessment. In this study, freshwater snails from two genetically differentiated populations of Lymnaea stagnalis were exposed to repeated acute applications of environmentally realistic concentrations of the herbicide diquat, from the embryo to the adult stage. Hatching rate, embryonic development duration, juvenile mortality, feeding rate and age at first spawning were investigated during both exposure and recovery periods. Effects of diquat on mortality were analysed using a threshold hazard model accounting for time-varying herbicide concentrations. All endpoints were significantly impaired at diquat environmental concentrations in both populations. Snail evolutionary history had no significant impact on their sensitivity and responsiveness to diquat, whereas food acted as a modulating factor of toxicant-induced mortality. The time course of effects was adequately described by the model, which thus appears suitable to analyse long-term effects of complex exposure patterns based upon full life cycle experiment data. Obtained model outputs (e.g. no-effect concentrations) could be directly used for chemical risk assessment.

Analysis of Hydrogen Atom Abstraction from Ethylbenzene by an FeVO(TAML) Complex.

PubMed

Shen, Longzhu Q; Kundu, Soumen; Collins, Terrence J; Bominaar, Emile L

2017-04-17

It was shown previously (Chem. Eur. J. 2015, 21, 1803) that the rate of hydrogen atom abstraction, k, from ethylbenzene (EB) by TAML complex [Fe V (O)B*] - (1) in acetonitrile exhibits a large kinetic isotope effect (KIE ∼ 26) in the experimental range 233-243 K. The extrapolated tangents of ln(k/T) vs T -1 plots for EB-d 10 and EB gave a large, negative intercept difference, Int(EB) - Int(EB-d 10 ) = -34.5 J mol -1 K -1 for T -1 → 0, which is shown to be exclusively due to an isotopic mass effect on tunneling. A decomposition of the apparent activation barrier in terms of electronic, ZPE, thermal enthalpic, tunneling, and entropic contributions is presented. Tunneling corrections to ΔH ⧧ and ΔS ⧧ are estimated to be large. The DFT prediction, using functional B3LYP and basis set 6-311G, for the electronic contribution is significantly smaller than suggested by experiment. However, the agreement improves after correction for the basis set superposition error in the interaction between EB and 1. The kinetic model employed has been used to predict rate constants outside the experimental temperature range, which enabled us to compare the reactivity of 1 with those of other hydrogen abstracting complexes.

Dense infraspecific sampling reveals rapid and independent trajectories of plastome degradation in a heterotrophic orchid complex.

PubMed

Barrett, Craig F; Wicke, Susann; Sass, Chodon

2018-05-01

Heterotrophic plants provide excellent opportunities to study the effects of altered selective regimes on genome evolution. Plastid genome (plastome) studies in heterotrophic plants are often based on one or a few highly divergent species or sequences as representatives of an entire lineage, thus missing important evolutionary-transitory events. Here, we present the first infraspecific analysis of plastome evolution in any heterotrophic plant. By combining genome skimming and targeted sequence capture, we address hypotheses on the degree and rate of plastome degradation in a complex of leafless orchids (Corallorhiza striata) across its geographic range. Plastomes provide strong support for relationships and evidence of reciprocal monophyly between C. involuta and the endangered C. bentleyi. Plastome degradation is extensive, occurring rapidly over a few million years, with evidence of differing rates of genomic change among the two principal clades of the complex. Genome skimming and targeted sequence capture differ widely in coverage depth overall, with depth in targeted sequence capture datasets varying immensely across the plastome as a function of GC content. These findings will help to fill a knowledge gap in models of heterotrophic plastid genome evolution, and have implications for future studies in heterotrophs. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Characterization of Modified Tapioca Starch Solutions and Their Sprays for High Temperature Coating Applications

PubMed Central

Naz, M. Y.; Sulaiman, S. A.; Ariwahjoedi, B.; Shaari, Ku Zilati Ku

2014-01-01

The objective of the research was to understand and improve the unusual physical and atomization properties of the complexes/adhesives derived from the tapioca starch by addition of borate and urea. The characterization of physical properties of the synthesized adhesives was carried out by determining the effect of temperature, shear rate, and mass concentration of thickener/stabilizer on the complex viscosity, density, and surface tension. In later stage, phenomenological analyses of spray jet breakup of heated complexes were performed in still air. Using a high speed digital camera, the jet breakup dynamics were visualized as a function of the system input parameters. The further analysis of the grabbed images confirmed the strong influence of the input processing parameters on full cone spray patternation. It was also predicted that the heated starch adhesive solutions generate a dispersed spray pattern by utilizing the partial evaporation of the spraying medium. Below 40°C of heating temperature, the radial spray cone width and angle did not vary significantly with increasing Reynolds and Weber numbers at early injection phases leading to increased macroscopic spray propagation. The discharge coefficient, mean flow rate, and mean flow velocity were significantly influenced by the load pressure but less affected by the temperature. PMID:24592165

Specificity and kinetics of haloalkane dehalogenase.

PubMed

Schanstra, J P; Kingma, J; Janssen, D B

1996-06-21

Haloalkane dehalogenase converts halogenated alkanes to their corresponding alcohols. The active site is buried inside the protein and lined with hydrophobic residues. The reaction proceeds via a covalent substrate-enzyme complex. This paper describes a steady-state and pre-steady-state kinetic analysis of the conversion of a number of substrates of the dehalogenase. The kinetic mechanism for the "natural" substrate 1,2-dichloroethane and for the brominated analog and nematocide 1,2-dibromoethane are given. In general, brominated substrates had a lower Km, but a similar kcat than the chlorinated analogs. The rate of C-Br bond cleavage was higher than the rate of C-Cl bond cleavage, which is in agreement with the leaving group abilities of these halogens. The lower Km for brominated compounds therefore originates both from the higher rate of C-Br bond cleavage and from a lower Ks for bromo-compounds. However, the rate-determining step in the conversion (kcat) of 1, 2-dibromoethane and 1,2-dichloroethane was found to be release of the charged halide ion out of the active site cavity, explaining the different Km but similar kcat values for these compounds. The study provides a basis for the analysis of rate-determining steps in the hydrolysis of various environmentally important substrates.

Identifying Changes of Complex Flood Dynamics with Recurrence Analysis

NASA Astrophysics Data System (ADS)

Wendi, D.; Merz, B.; Marwan, N.

2016-12-01

Temporal changes in flood hazard system are known to be difficult to detect and attribute due to multiple drivers that include complex processes that are non-stationary and highly variable. These drivers, such as human-induced climate change, natural climate variability, implementation of flood defense, river training, or land use change, could impact variably on space-time scales and influence or mask each other. Flood time series may show complex behavior that vary at a range of time scales and may cluster in time. Moreover hydrological time series (i.e. discharge) are often subject to measurement errors, such as rating curve error especially in the case of extremes where observation are actually derived through extrapolation. This study focuses on the application of recurrence based data analysis techniques (recurrence plot) for understanding and quantifying spatio-temporal changes in flood hazard in Germany. The recurrence plot is known as an effective tool to visualize the dynamics of phase space trajectories i.e. constructed from a time series by using an embedding dimension and a time delay, and it is known to be effective in analyzing non-stationary and non-linear time series. Sensitivity of the common measurement errors and noise on recurrence analysis will also be analyzed and evaluated against conventional methods. The emphasis will be on the identification of characteristic recurrence properties that could associate typical dynamic to certain flood events.

Molecular complexity of successive bacterial epidemics deconvoluted by comparative pathogenomics.

PubMed

Beres, Stephen B; Carroll, Ronan K; Shea, Patrick R; Sitkiewicz, Izabela; Martinez-Gutierrez, Juan Carlos; Low, Donald E; McGeer, Allison; Willey, Barbara M; Green, Karen; Tyrrell, Gregory J; Goldman, Thomas D; Feldgarden, Michael; Birren, Bruce W; Fofanov, Yuriy; Boos, John; Wheaton, William D; Honisch, Christiane; Musser, James M

2010-03-02

Understanding the fine-structure molecular architecture of bacterial epidemics has been a long-sought goal of infectious disease research. We used short-read-length DNA sequencing coupled with mass spectroscopy analysis of SNPs to study the molecular pathogenomics of three successive epidemics of invasive infections involving 344 serotype M3 group A Streptococcus in Ontario, Canada. Sequencing the genome of 95 strains from the three epidemics, coupled with analysis of 280 biallelic SNPs in all 344 strains, revealed an unexpectedly complex population structure composed of a dynamic mixture of distinct clonally related complexes. We discovered that each epidemic is dominated by micro- and macrobursts of multiple emergent clones, some with distinct strain genotype-patient phenotype relationships. On average, strains were differentiated from one another by only 49 SNPs and 11 insertion-deletion events (indels) in the core genome. Ten percent of SNPs are strain specific; that is, each strain has a unique genome sequence. We identified nonrandom temporal-spatial patterns of strain distribution within and between the epidemic peaks. The extensive full-genome data permitted us to identify genes with significantly increased rates of nonsynonymous (amino acid-altering) nucleotide polymorphisms, thereby providing clues about selective forces operative in the host. Comparative expression microarray analysis revealed that closely related strains differentiated by seemingly modest genetic changes can have significantly divergent transcriptomes. We conclude that enhanced understanding of bacterial epidemics requires a deep-sequencing, geographically centric, comparative pathogenomics strategy.

Modelling lifetime cost consequences of toric compared with standard IOLs in cataract surgery of astigmatic patients in four European countries.

PubMed

Laurendeau, C; Lafuma, A; Berdeaux, G

2009-09-01

To compare the lifetime costs of freeing astigmatic patients from spectacles after bilateral cataract surgery implanting toric intraocular lenses (IOLs: i.e., Acrysof Toric) versus monofocal IOLs, in France, Italy, Germany and Spain. A Markov model followed patient cohorts from cataract surgery until death. Prevalence rates of patients not needing spectacles and the types of spectacles prescribed for those requiring them were obtained from clinical trials and national surveys. The economic perspective was societal. Mortality rates were incorporated into the model. Discount rates were applied. A sensitivity analysis was performed on non-discounted costs. Fewer patients with toric IOLs needed spectacles for distance vision than patients with monofocal IOLs. With monofocal IOLs more than 66% of patients needed complex spectacles compared to less than 25% implanted with toric IOLs. In France and Italy, toric IOLs reduced overall costs relative to otherwise high spectacle costs after cataract surgery. Savings were 897.0 euros (France), 822.5 euros (Germany), 895.8 euros (Italy) and 391.6 euros (Spain), without discounting. On applying a 3% discount rate the costs became 691.7 euros, 646.4 euros, 693.9 euros and 308.2 euros, respectively. Bilateral toric IOL implants in astigmatic patients decreased spectacle dependence for distance vision and the need for complex spectacles. The economic consequences for patients depended on the national spectacle costs usually incurred after cataract surgery.

In vivo analysis of Purkinje cell firing properties during postnatal mouse development

PubMed Central

Arancillo, Marife; White, Joshua J.; Lin, Tao; Stay, Trace L.

2014-01-01

Purkinje cell activity is essential for controlling motor behavior. During motor behavior Purkinje cells fire two types of action potentials: simple spikes that are generated intrinsically and complex spikes that are induced by climbing fiber inputs. Although the functions of these spikes are becoming clear, how they are established is still poorly understood. Here, we used in vivo electrophysiology approaches conducted in anesthetized and awake mice to record Purkinje cell activity starting from the second postnatal week of development through to adulthood. We found that the rate of complex spike firing increases sharply at 3 wk of age whereas the rate of simple spike firing gradually increases until 4 wk of age. We also found that compared with adult, the pattern of simple spike firing during development is more irregular as the cells tend to fire in bursts that are interrupted by long pauses. The regularity in simple spike firing only reached maturity at 4 wk of age. In contrast, the adult complex spike pattern was already evident by the second week of life, remaining consistent across all ages. Analyses of Purkinje cells in alert behaving mice suggested that the adult patterns are attained more than a week after the completion of key morphogenetic processes such as migration, lamination, and foliation. Purkinje cell activity is therefore dynamically sculpted throughout postnatal development, traversing several critical events that are required for circuit formation. Overall, we show that simple spike and complex spike firing develop with unique developmental trajectories. PMID:25355961

Nanovehicles as a novel target strategy for hyperthermic intraperitoneal chemotherapy: a multidisciplinary study of peritoneal carcinomatosis

PubMed Central

Nowacki, Maciej; Wisniewski, Marek; Werengowska-Ciecwierz, Karolina; Roszek, Katarzyna; Czarnecka, Joanna; Łakomska, I.; Kloskowski, Tomasz; Tyloch, Dominik; Debski, Robert; Pietkun, Katarzyna; Pokrywczynska, Marta; Grzanka, Dariusz; Czajkowski, Rafał; Drewa, Gerard; Jundziłł, A.; Agyin, Joseph K.; Habib, Samy L.; Terzyk, Artur P.; Drewa, Tomasz

2015-01-01

In general, detection of peritoneal carcinomatosis (PC) occurs at the late stage when there is no treatment option. In the present study, we designed novel drug delivery systems that are functionalized with anti-CD133 antibodies. The C1, C2 and C3 complexes with cisplatin were introduced into nanotubes, either physically or chemically. The complexes were reacted with anti-CD133 antibody to form the labeled product of A0-o-CX-chem-CD133. Cytotoxicity screening of all the complexes was performed on CHO cells. Data showed that both C2 and C3 Pt-complexes are more cytotoxic than C1. Flow-cytometry analysis showed that nanotubes conjugated to CD133 antibody have the ability to target cells expressing the CD133 antigen which is responsible for the emergence of resistance to chemotherapy and disease recurrence. The shortest survival rate was observed in the control mice group (K3) where no hyperthermic intraperitoneal chemotherapy procedures were used. On the other hand, the longest median survival rate was observed in the group treated with A0-o-C1-chem-CD133. In summary, we designed a novel drug delivery system based on carbon nanotubes loaded with Pt-prodrugs and functionalized with anti-CD133 antibodies. Our data demonstrates the effectiveness of the new drug delivery system and provides a novel therapeutic modality in the treatment of melanoma. PMID:26254295

Cu(II), Co(II) and Ni(II) complexes of new Schiff base ligand: Synthesis, thermal and spectroscopic characterizations

NASA Astrophysics Data System (ADS)

Refat, Moamen S.; El-Sayed, Mohamed Y.; Adam, Abdel Majid A.

2013-04-01

Cu(II), Co(II), and Ni(II) complexes were synthesized from 2-[(5-o-chlorophenylazo-2-hydroxybenzylidin)amino]-phenol Schiff base (H2L). Metal ions coordinate in a tetradentate or hexadentate features with these O2N donor ligand, which are characterized by elemental analyses, magnetic moments, infrared, Raman laser, electronic, and 1H NMR spectral studies. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). Reactions with Cu(II), Co(II) and Ni(II), resulted [Cu(H2L)(H2O)2(Cl)]Cl, [Co(H2L)(H2O)3]Cl2ṡ3H2O and [Ni(H2L)(H2O)2]Cl2ṡ6H2O. The thermal decomposition behavior of H2L complexes has been investigated by thermogravimetric analysis (TG/DTG) at a heating rate of 10 °C min-1 under nitrogen atmosphere. The brightness side in this study is to take advantage for the preparation and characterizations of single phases of CuO, CoO and NiO nanoparticles using H2L complexes as precursors via a solid-state decomposition procedure. The crystalline structures of products using X-ray diffractometer (XRD), morphology of particles by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) were investigated.

Generative complexity of Gray-Scott model

NASA Astrophysics Data System (ADS)

Adamatzky, Andrew

2018-03-01

In the Gray-Scott reaction-diffusion system one reactant is constantly fed in the system, another reactant is reproduced by consuming the supplied reactant and also converted to an inert product. The rate of feeding one reactant in the system and the rate of removing another reactant from the system determine configurations of concentration profiles: stripes, spots, waves. We calculate the generative complexity-a morphological complexity of concentration profiles grown from a point-wise perturbation of the medium-of the Gray-Scott system for a range of the feeding and removal rates. The morphological complexity is evaluated using Shannon entropy, Simpson diversity, approximation of Lempel-Ziv complexity, and expressivity (Shannon entropy divided by space-filling). We analyse behaviour of the systems with highest values of the generative morphological complexity and show that the Gray-Scott systems expressing highest levels of the complexity are composed of the wave-fragments (similar to wave-fragments in sub-excitable media) and travelling localisations (similar to quasi-dissipative solitons and gliders in Conway's Game of Life).

Integrating genome-wide association study summaries and element-gene interaction datasets identified multiple associations between elements and complex diseases.

PubMed

He, Awen; Wang, Wenyu; Prakash, N Tejo; Tinkov, Alexey A; Skalny, Anatoly V; Wen, Yan; Hao, Jingcan; Guo, Xiong; Zhang, Feng

2018-03-01

Chemical elements are closely related to human health. Extensive genomic profile data of complex diseases offer us a good opportunity to systemically investigate the relationships between elements and complex diseases/traits. In this study, we applied gene set enrichment analysis (GSEA) approach to detect the associations between elements and complex diseases/traits though integrating element-gene interaction datasets and genome-wide association study (GWAS) data of complex diseases/traits. To illustrate the performance of GSEA, the element-gene interaction datasets of 24 elements were extracted from the comparative toxicogenomics database (CTD). GWAS summary datasets of 24 complex diseases or traits were downloaded from the dbGaP or GEFOS websites. We observed significant associations between 7 elements and 13 complex diseases or traits (all false discovery rate (FDR) < 0.05), including reported relationships such as aluminum vs. Alzheimer's disease (FDR = 0.042), calcium vs. bone mineral density (FDR = 0.031), magnesium vs. systemic lupus erythematosus (FDR = 0.012) as well as novel associations, such as nickel vs. hypertriglyceridemia (FDR = 0.002) and bipolar disorder (FDR = 0.027). Our study results are consistent with previous biological studies, supporting the good performance of GSEA. Our analyzing results based on GSEA framework provide novel clues for discovering causal relationships between elements and complex diseases. © 2017 WILEY PERIODICALS, INC.

Electron microscopy and in vitro deneddylation reveal similar architectures and biochemistry of isolated human and Flag-mouse COP9 signalosome complexes

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

Rockel, Beate; Schmaler, Tilo; Huang, Xiaohua

2014-07-25

Highlights: • Deneddylation rates of human erythrocyte and mouse fibroblast CSN are very similar. • 3D models of native human and mouse CSN reveal common architectures. • The cryo-structure of native mammalian CSN shows a horseshoe subunit arrangement. - Abstract: The COP9 signalosome (CSN) is a regulator of the ubiquitin (Ub) proteasome system (UPS). In the UPS, proteins are Ub-labeled for degradation by Ub ligases conferring substrate specificity. The CSN controls a large family of Ub ligases called cullin-RING ligases (CRLs), which ubiquitinate cell cycle regulators, transcription factors and DNA damage response proteins. The CSN possesses structural similarities with themore » 26S proteasome Lid complex and the translation initiation complex 3 (eIF3) indicating similar ancestry and function. Initial structures were obtained 14 years ago by 2D electron microscopy (EM). Recently, first 3D molecular models of the CSN were created on the basis of negative-stain EM and single-particle analysis, mostly with recombinant complexes. Here, we compare deneddylating activity and structural features of CSN complexes purified in an elaborate procedure from human erythrocytes and efficiently pulled down from mouse Flag-CSN2 B8 fibroblasts. In an in vitro deneddylation assay both the human and the mouse CSN complexes deneddylated Nedd8-Cul1 with comparable rates. 3D structural models of the erythrocyte CSN as well as of the mouse Flag-CSN were generated by negative stain EM and by cryo-EM. Both complexes show a central U-shaped segment from which several arms emanate. This structure, called the horseshoe, is formed by the PCI domain subunits. CSN5 and CSN6 point away from the horseshoe. Compared to 3D models of negatively stained CSN complexes, densities assigned to CSN2 and CSN4 are better defined in the cryo-map. Because biochemical and structural results obtained with CSN complexes isolated from human erythrocytes and purified by Flag-CSN pulldown from mouse B8 fibroblasts are very similar, Flag-CSN pulldowns are a proper alternative to CSN preparation from erythrocytes.« less

Benchmarking quantitative label-free LC-MS data processing workflows using a complex spiked proteomic standard dataset.

PubMed

Ramus, Claire; Hovasse, Agnès; Marcellin, Marlène; Hesse, Anne-Marie; Mouton-Barbosa, Emmanuelle; Bouyssié, David; Vaca, Sebastian; Carapito, Christine; Chaoui, Karima; Bruley, Christophe; Garin, Jérôme; Cianférani, Sarah; Ferro, Myriam; Van Dorssaeler, Alain; Burlet-Schiltz, Odile; Schaeffer, Christine; Couté, Yohann; Gonzalez de Peredo, Anne

2016-01-30

Proteomic workflows based on nanoLC-MS/MS data-dependent-acquisition analysis have progressed tremendously in recent years. High-resolution and fast sequencing instruments have enabled the use of label-free quantitative methods, based either on spectral counting or on MS signal analysis, which appear as an attractive way to analyze differential protein expression in complex biological samples. However, the computational processing of the data for label-free quantification still remains a challenge. Here, we used a proteomic standard composed of an equimolar mixture of 48 human proteins (Sigma UPS1) spiked at different concentrations into a background of yeast cell lysate to benchmark several label-free quantitative workflows, involving different software packages developed in recent years. This experimental design allowed to finely assess their performances in terms of sensitivity and false discovery rate, by measuring the number of true and false-positive (respectively UPS1 or yeast background proteins found as differential). The spiked standard dataset has been deposited to the ProteomeXchange repository with the identifier PXD001819 and can be used to benchmark other label-free workflows, adjust software parameter settings, improve algorithms for extraction of the quantitative metrics from raw MS data, or evaluate downstream statistical methods. Bioinformatic pipelines for label-free quantitative analysis must be objectively evaluated in their ability to detect variant proteins with good sensitivity and low false discovery rate in large-scale proteomic studies. This can be done through the use of complex spiked samples, for which the "ground truth" of variant proteins is known, allowing a statistical evaluation of the performances of the data processing workflow. We provide here such a controlled standard dataset and used it to evaluate the performances of several label-free bioinformatics tools (including MaxQuant, Skyline, MFPaQ, IRMa-hEIDI and Scaffold) in different workflows, for detection of variant proteins with different absolute expression levels and fold change values. The dataset presented here can be useful for tuning software tool parameters, and also testing new algorithms for label-free quantitative analysis, or for evaluation of downstream statistical methods. Copyright © 2015 Elsevier B.V. All rights reserved.

The Spatial Structure of Planform Migration - Curvature Relation of Meandering Rivers

NASA Astrophysics Data System (ADS)

Guneralp, I.; Rhoads, B. L.

2005-12-01

Planform dynamics of meandering rivers have been of fundamental interest to fluvial geomorphologists and engineers because of the intriguing complexity of these dynamics, the role of planform change in floodplain development and landscape evolution, and the economic and social consequences of bank erosion and channel migration. Improved understanding of the complex spatial structure of planform change and capacity to predict these changes are important for effective stream management, engineering and restoration. The planform characteristics of a meandering river channel are integral to its planform dynamics. Active meandering rivers continually change their positions and shapes as a consequence of hydraulic forces exerted on the channel banks and bed, but as the banks and bed change through sediment transport, so do the hydraulic forces. Thus far, this complex feedback between form and process is incompletely understood, despite the fact that the characteristics and the dynamics of meandering rivers have been studied extensively. Current theoretical models aimed at predicting planform dynamics relate rates of meander migration to local and upstream planform curvature where weighting of the influence of curvature on migration rate decays exponentially over distance. This theoretical relation, however, has not been rigorously evaluated empirically. Furthermore, although models based on exponential-weighting of curvature effects yield fairly realistic predictions of meander migration, such models are incapable of reproducing complex forms of bend development, such as double heading or compound looping. This study presents the development of a new methodology based on parametric cubic spline interpolation for the characterization of channel planform and the planform curvature of meandering rivers. The use of continuous mathematical functions overcomes the reliance on bend-averaged values or piece-wise discrete approximations of planform curvature - a major limitation of previous studies. Continuous curvature series can be related to measured rates of lateral migration to explore empirically the relationship between spatially extended curvature and local bend migration. The methodology is applied to a study reach along a highly sinuous section of the Embarras River in Illinois, USA, which contains double-headed asymmetrical loops. To identify patterns of channel planform and rates of lateral migration for a study reach along Embarrass River in central Illinois, geographical information systems analysis of historical aerial photography over a period from 1936 to 1998 was conducted. Results indicate that parametric cubic spline interpolation provides excellent characterization of the complex planforms and planform curvatures of meandering rivers. The findings also indicate that the spatial structure of migration rate-curvature relation may be more complex than a simple exponential distance-decay function. The study represents a first step toward unraveling the spatial structure of planform evolution of meandering rivers and for developing models of planform dynamics that accurately relate spatially extended patterns of channel curvature to local rates of lateral migration. Such knowledge is vital for improving the capacity to accurately predict planform change of meandering rivers.

Heart Rate Complexity in Response to Upright Tilt in Persons with Down Syndrome

ERIC Educational Resources Information Center

Agiovlasitis, Stamatis; Baynard, Tracy; Pitetti, Kenneth H.; Fernhall, Bo

2011-01-01

People with Down syndrome (DS) show altered autonomic response to sympatho-excitation. Cardiac autonomic modulation may be examined with heart rate (HR) complexity which is associated uniquely with cardiovascular risk. This study examined whether the response of HR complexity to passive upright tilt differs between persons with and without DS and…

Social complexity, modernity and suicide: an assessment of Durkheim's suicide from the perspective of a non-linear analysis of complex social systems.

PubMed

Condorelli, Rosalia

2016-01-01

Can we share even today the same vision of modernity which Durkheim left us by its suicide analysis? or can society 'surprise us'? The answer to these questions can be inspired by several studies which found that beginning the second half of the twentieth century suicides in western countries more industrialized and modernized do not increase in a constant, linear way as modernization and social fragmentation process increases, as well as Durkheim's theory seems to lead us to predict. Despite continued modernizing process, they found stabilizing or falling overall suicide rate trends. Therefore, a gradual process of adaptation to the stress of modernization associated to low social integration levels seems to be activated in modern society. Assuming this perspective, the paper highlights as this tendency may be understood in the light of the new concept of social systems as complex adaptive systems, systems which are able to adapt to environmental perturbations and generate as a whole surprising, emergent effects due to nonlinear interactions among their components. So, in the frame of Nonlinear Dynamical System Modeling, we formalize the logic of suicide decision-making process responsible for changes at aggregate level in suicide growth rates by a nonlinear differential equation structured in a logistic way, and in so doing we attempt to capture the mechanism underlying the change process in suicide growth rate and to test the hypothesis that system's dynamics exhibits a restrained increase process as expression of an adaptation process to the liquidity of social ties in modern society. In particular, a Nonlinear Logistic Map is applied to suicide data in a modern society such as the Italian one from 1875 to 2010. The analytic results, seeming to confirm the idea of the activation of an adaptation process to the liquidity of social ties, constitutes an opportunity for a more general reflection on the current configuration of modern society, by relating the Durkheimian Theory with the Halbwachs' Theory and most current visions of modernity such as the Baumanian one. Complexity completes the interpretative framework by rooting the generating mechanism of adaptation process in the precondition of a new General Theory of Systems making the non linearity property of social system's interactions and surprise the functioning and evolution rule of social systems.

Using open-ended data to enrich survey results on the meanings of self-rated health: a study among women in underprivileged communities in Beirut, Lebanon.

PubMed

Salem, Mylene Tewtel; Abdulrahim, Sawsan; Zurayk, Huda

2009-12-01

This study extends the debate on self-rated health by using different sources of data in the same study to explore the meanings of self-rated health among women who live in socio-economically disadvantaged communities in Beirut, Lebanon. Using data from the Urban Health Study, a cross-sectional household survey of 1,869 women between 15 and 59 years of age, multiple logistic regression models were developed to assess factors associated with self-rated health. Also, open-ended data was used to analyze women's explanations of their self-rated health ratings. Self-rated health was found to be a complex concept, associated not only with physical health but also with a combination of social, psychological, and behavioral factors. This open-ended analysis revealed new meanings of self-rated health that are often not included in self-rated health epidemiologic research, such as women's experiences with pain and fatigue, as well as exposure to financial stressors and the legacy of wars. We argue that triangulating survey and open-ended data provides a better understanding of the context-specific social and cultural meanings of self-rated health.

Accounting for rate instability and spatial patterns in the boundary analysis of cancer mortality maps

PubMed Central

Goovaerts, Pierre

2006-01-01

Boundary analysis of cancer maps may highlight areas where causative exposures change through geographic space, the presence of local populations with distinct cancer incidences, or the impact of different cancer control methods. Too often, such analysis ignores the spatial pattern of incidence or mortality rates and overlooks the fact that rates computed from sparsely populated geographic entities can be very unreliable. This paper proposes a new methodology that accounts for the uncertainty and spatial correlation of rate data in the detection of significant edges between adjacent entities or polygons. Poisson kriging is first used to estimate the risk value and the associated standard error within each polygon, accounting for the population size and the risk semivariogram computed from raw rates. The boundary statistic is then defined as half the absolute difference between kriged risks. Its reference distribution, under the null hypothesis of no boundary, is derived through the generation of multiple realizations of the spatial distribution of cancer risk values. This paper presents three types of neutral models generated using methods of increasing complexity: the common random shuffle of estimated risk values, a spatial re-ordering of these risks, or p-field simulation that accounts for the population size within each polygon. The approach is illustrated using age-adjusted pancreatic cancer mortality rates for white females in 295 US counties of the Northeast (1970–1994). Simulation studies demonstrate that Poisson kriging yields more accurate estimates of the cancer risk and how its value changes between polygons (i.e. boundary statistic), relatively to the use of raw rates or local empirical Bayes smoother. When used in conjunction with spatial neutral models generated by p-field simulation, the boundary analysis based on Poisson kriging estimates minimizes the proportion of type I errors (i.e. edges wrongly declared significant) while the frequency of these errors is predicted well by the p-value of the statistical test. PMID:19023455

Isolation and Characterization of Proteolytic Ruminal Bacteria from Sheep and Goats Fed the Tannin-Containing Shrub Legume Calliandra calothyrsus

PubMed Central

McSweeney, Christopher S.; Palmer, Brian; Bunch, Rowan; Krause, Denis O.

1999-01-01

Tannins in forages complex with protein and reduce the availability of nitrogen to ruminants. Ruminal bacteria that ferment protein or peptides in the presence of tannins may benefit digestion of these diets. Bacteria from the rumina of sheep and goats fed Calliandra calothyrsus (3.6% N and 6% condensed tannin) were isolated on proteinaceous agar medium overlaid with either condensed (calliandra tannin) or hydrolyzable (tannic acid) tannin. Fifteen genotypes were identified, based on 16S ribosomal DNA-restriction fragment length polymorphism analysis, and all were proteolytic and fermented peptides to ammonia. Ten of the isolates grew to high optical density (OD) on carbohydrates (glucose, cellobiose, xylose, xylan, starch, and maltose), while the other isolates did not utilize or had low growth on these substrates. In pure culture, representative isolates were unable to ferment protein that was present in calliandra or had been complexed with tannin. One isolate, Lp1284, had high protease activity (80 U), a high specific growth rate (0.28), and a high rate of ammonia production (734 nmol/min/ml/OD unit) on Casamino Acids and Trypticase Peptone. Phylogenetic analysis of the 16S ribosomal DNA sequence showed that Lp1284 was related (97.6%) to Clostridium botulinum NCTC 7273. Purified plant protein and casein also supported growth of Lp1284 and were fermented to ammonia. This is the first report of a proteolytic, ammonia-hyperproducing bacterium from the rumen. In conclusion, a diverse group of proteolytic and peptidolytic bacteria were present in the rumen, but the isolates could not digest protein that was complexed with condensed tannin. PMID:10388706

Tachydysrhythmia treatment and adverse events in patients with wolff-Parkinson-white syndrome.

PubMed

Siegelman, Jeffrey N; Marill, Keith A; Adler, Jonathan N

2014-09-01

Current guidelines recommend avoiding atrioventricular-nodal blocking agents (AVNB) when treating tachydysrhythmias in Wolff-Parkinson-White syndrome (WPW) patients. We investigated medications selected and resulting outcomes for patients with tachydysrhythmias and WPW. In this single-center retrospective cohort study, we searched a hospital-wide database for the following inclusion criteria: WPW, tachycardia, and intravenous antidysrhythmics. The composite outcome of adverse events was acceleration of tachycardia, new hypotension, new malignant dysrhythmia, and cardioversion. The difference in binomial proportions of patients meeting the composite outcome after AVNB or non-AVNB (NAVNB) treatment was calculated after dividing the groups by QRS duration. A random-effects mixed linear analysis was performed to analyze the vital sign response. The initial database search yielded 1158 patient visits, with 60 meeting inclusion criteria. Patients' median age was 52.5 years; 53% were male, 43% presented in wide complex tachycardia (WCT), with 75% in atrial fibrillation (AF) or flutter. AVNBs were administered in 42 (70%) patient visits. For those patients with WCT in AF, the difference in proportions of patients meeting the composite outcome after AVNBs vs. NAVNBs treatment was an increase of 3% (95% confidence interval [CI] -39%-49%), and for those with narrow complex AF it was a decrease of 13% (95% CI -37%-81%). No instances of malignant dysrhythmia occurred. Mixed linear analysis showed no statistically significant effects on heart rate, though suggested a trend toward increasing heart rate after AVNB in wide complex AF. In this sample of WPW-associated tachydysrhythmia patients, many were treated with AVNBs. The composite outcome was similarly met after use of either AVNB or NAVNB, and no malignant dysrhythmias were observed. Copyright © 2014 Elsevier Inc. All rights reserved.

Generalization of the Activated Complex Theory of Reaction Rates. I. Quantum Mechanical Treatment

DOE R&D Accomplishments Database

Marcus, R. A.

1964-01-01

In its usual form activated complex theory assumes a quasi-equilibrium between reactants and activated complex, a separable reaction coordinate, a Cartesian reaction coordinate, and an absence of interaction of rotation with internal motion in the complex. In the present paper a rate expression is derived without introducing the Cartesian assumption. The expression bears a formal resemblance to the usual one and reduces to it when the added assumptions of the latter are introduced.

Objective measures of renal mass anatomic complexity predict rates of major complications following partial nephrectomy.

PubMed

Simhan, Jay; Smaldone, Marc C; Tsai, Kevin J; Canter, Daniel J; Li, Tianyu; Kutikov, Alexander; Viterbo, Rosalia; Chen, David Y T; Greenberg, Richard E; Uzzo, Robert G

2011-10-01

The association between tumor complexity and postoperative complications after partial nephrectomy (PN) has not been well characterized. We evaluated whether increasing renal tumor complexity, quantitated by nephrometry score (NS), is associated with increased complication rates following PN using the Clavien-Dindo classification system (CCS). We queried our prospectively maintained kidney cancer database for patients undergoing PN from 2007 to 2010 for whom NS was available. All patients underwent PN. Tumors were categorized into low- (NS: 4-6), moderate- (NS: 7-9), and high-complexity (NS: 10-12) lesions. Complication rates within 30 d were graded (CCS: I-5), stratified as minor (CCS: I or 2) or major (CCS: 3-5), and compared between groups. A total of 390 patients (mean age: 58.0 ± 11.9 yr; 66.9% male) undergoing PN (44.6% open, 55.4% robotic) for low- (28%), moderate- (55.6%), and high-complexity (16.4%) tumors (mean tumor size: 3.74 ± 2.4 cm; median: 3.2 cm) from 2007 to 2010 were identified. Tumor size, estimated blood loss, and ischemia time all significantly differed (p<0.0001) between groups; patient age, body mass index (BMI), and operative time were comparable. When stratified by CCS, minor and major complication rates for all patients were 26.7% and 11.5%, respectively. Minor complication rates were comparable (26.6 vs. 24.9 vs 32.8%; p=0.45), whereas major complication rates differed (6.4 vs. 11.1 vs. 21.9%; p=0.009) among tumor complexity groups. Controlling for age, gender, BMI, type of surgical approach, operative duration, and tumor complexity, prolonged operative time (odds ratio [OR]: 1.01; confidence interval [CI], 1.0-1.02) and high tumor complexity (OR: 5.4; CI, 1.2-24.2) were associated with the postoperative development of a major complication. Lack of external validation is a limitation of this study. Increasing tumor complexity is associated with the development of major complications after PN. This association should be validated externally and integrated into the decision-making process when counseling patients with complex renal tumors. Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Fractal structure of sequential behaviour patterns: an indicator of stress

USGS Publications Warehouse

Alados, C.L.; Escos, J.M; Emlen, J.M.

1996-01-01

The detection of stress arising from parasitic infection bySarcoptes scabieisand from pregnancy is explored, using a fractal analysis of head lifting behaviour and feeding–non-feeding activity sequences in female Spanish ibex,Capra pyrenaica, under natural conditions. Because organisms under stress increase their metabolic rate and, in consequence, energy consumption, it follows that stress will, generally, lead to a reduction in complexity (fractal dimension) of exploratory behaviour. In the present study the fractal dimension of the three measures of complexity used declined with stress, both from pregnancy and from parasitic infection. This observation provides a new and effective way to assess the general state of animals’ health in the field, without the need for capture and handling.

On improving the performance of nonphotochemical quenching in CP29 light-harvesting antenna complex

DOE PAGES

Berman, Gennady Petrovich; Nesterov, Alexander I.; Sayre, Richard Thomas; ...

2016-02-02

In this study, we model and simulate the performance of charge-transfer in nonphotochemical quenching (NPQ) in the CP29 light-harvesting antenna-complex associated with photosystem II (PSII). The model consists of five discrete excitonic energy states and two sinks, responsible for the potentially damaging processes and charge-transfer channels, respectively. We demonstrate that by varying (i) the parameters of the chlorophyll-based dimer, (ii) the resonant properties of the protein-solvent environment interaction, and (iii) the energy transfer rates to the sinks, one can significantly improve the performance of the NPQ. In conclusion, our analysis suggests strategies for improving the performance of the NPQ inmore » response to environmental changes, and may stimulate experimental verification.« less

The Aristotle Comprehensive Complexity score predicts mortality and morbidity after congenital heart surgery.

PubMed

Bojan, Mirela; Gerelli, Sébastien; Gioanni, Simone; Pouard, Philippe; Vouhé, Pascal

2011-04-01

The Aristotle Comprehensive Complexity (ACC) score has been proposed for complexity adjustment in the analysis of outcome after congenital heart surgery. The score is the sum of the Aristotle Basic Complexity score, largely used but poorly related to mortality and morbidity, and of the Comprehensive Complexity items accounting for comorbidities and procedure-specific and anatomic variability. This study aims to demonstrate the ability of the ACC score to predict 30-day mortality and morbidity assessed by the length of the intensive care unit (ICU) stay. We retrospectively enrolled patients undergoing congenital heart surgery in our institution. We modeled the ACC score as a continuous variable, mortality as a binary variable, and length of ICU stay as a censored variable. For each mortality and morbidity model we performed internal validation by bootstrapping and assessed overall performance by R(2), calibration by the calibration slope, and discrimination by the c index. Among all 1,454 patients enrolled, 30-day mortality rate was 3.4% and median length of ICU stay was 3 days. The ACC score strongly related to mortality, but related to length of ICU stay only during the first postoperative week. For the mortality model, R(2) = 0.24, calibration slope = 0.98, c index = 0.86, and 95% confidence interval was 0.82 to 0.91. For the morbidity model, R(2) = 0.094, calibration slope = 0.94, c index = 0.64, and 95% confidence interval was 0.62 to 0.66. The ACC score predicts 30-day mortality and length of ICU stay during the first postoperative week. The score is an adequate tool for complexity adjustment in the analysis of outcome after congenital heart surgery. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Proteomic analysis highlights the molecular complexities of native Kv4 channel macromolecular complexes.

PubMed

Marionneau, Céline; Townsend, R Reid; Nerbonne, Jeanne M

2011-04-01

Voltage-gated K(+) (Kv) channels are key determinants of membrane excitability in the nervous and cardiovascular systems, functioning to control resting membrane potentials, shape action potential waveforms and influence the responses to neurotransmitters and neurohormones. Consistent with this functional diversity, multiple types of Kv currents, with distinct biophysical properties and cellular/subcellular distributions, have been identified. Rapidly activating and inactivating Kv currents, typically referred to as I(A) (A-type) in neurons, for example, regulate repetitive firing rates, action potential back-propagation (into dendrites) and modulate synaptic responses. Currents with similar properties, referred to as I(to,f) (fast transient outward), expressed in cardiomyocytes, control the early phase of myocardial action potential repolarization. A number of studies have demonstrated critical roles for pore-forming (α) subunits of the Kv4 subfamily in the generation of native neuronal I(A) and cardiac I(to,f) channels. Studies in heterologous cells have also suggested important roles for a number of Kv channel accessory and regulatory proteins in the generation of functional I(A) and I(to,f) channels. Quantitative mass spectrometry-based proteomic analysis is increasingly recognized as a rapid and, importantly, unbiased, approach to identify the components of native macromolecular protein complexes. The recent application of proteomic approaches to identify the components of native neuronal (and cardiac) Kv4 channel complexes has revealed even greater complexity than anticipated. The continued emphasis on development of improved biochemical and analytical proteomic methods seems certain to accelerate progress and to provide important new insights into the molecular determinants of native ion channel protein complexes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Flow distribution analysis on the cooling tube network of ITER thermal shield

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

Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun

2014-01-29

Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube networkmore » for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.« less

Discovering functional interdependence relationship in PPI networks for protein complex identification.

PubMed

Lam, Winnie W M; Chan, Keith C C

2012-04-01

Protein molecules interact with each other in protein complexes to perform many vital functions, and different computational techniques have been developed to identify protein complexes in protein-protein interaction (PPI) networks. These techniques are developed to search for subgraphs of high connectivity in PPI networks under the assumption that the proteins in a protein complex are highly interconnected. While these techniques have been shown to be quite effective, it is also possible that the matching rate between the protein complexes they discover and those that are previously determined experimentally be relatively low and the "false-alarm" rate can be relatively high. This is especially the case when the assumption of proteins in protein complexes being more highly interconnected be relatively invalid. To increase the matching rate and reduce the false-alarm rate, we have developed a technique that can work effectively without having to make this assumption. The name of the technique called protein complex identification by discovering functional interdependence (PCIFI) searches for protein complexes in PPI networks by taking into consideration both the functional interdependence relationship between protein molecules and the network topology of the network. The PCIFI works in several steps. The first step is to construct a multiple-function protein network graph by labeling each vertex with one or more of the molecular functions it performs. The second step is to filter out protein interactions between protein pairs that are not functionally interdependent of each other in the statistical sense. The third step is to make use of an information-theoretic measure to determine the strength of the functional interdependence between all remaining interacting protein pairs. Finally, the last step is to try to form protein complexes based on the measure of the strength of functional interdependence and the connectivity between proteins. For performance evaluation, PCIFI was used to identify protein complexes in real PPI network data and the protein complexes it found were matched against those that were previously known in MIPS. The results show that PCIFI can be an effective technique for the identification of protein complexes. The protein complexes it found can match more known protein complexes with a smaller false-alarm rate and can provide useful insights into the understanding of the functional interdependence relationships between proteins in protein complexes.

Comparison of higher order spectra in heart rate signals during two techniques of meditation: Chi and Kundalini meditation.

PubMed

Goshvarpour, Ateke; Goshvarpour, Atefeh

2013-02-01

The human heartbeat is one of the important examples of complex physiologic fluctuations. For the first time in this study higher order spectra of heart rate signals during meditation have explored. Specifically, the aim of this study was to analysis and compares the contribution of quadratic phase coupling of human heart rate variability during two forms of meditation: (1) Chinese Chi (or Qigong) meditation and (2) Kundalini Yoga meditation. For this purpose, Bispectrum was estimated by using biased, parametric and the direct (FFT) method. The results show that the mean Bispectrum magnitude of heart rate signals increased during Kundalini Yoga meditation, but it decreased significantly during Chi meditation. However, in both meditation techniques phase-coupled harmonics are shifted to the higher frequencies during meditation. In addition, it has shown that not only there are significant differences between rest and meditation states, but also heart rate patterns appear to be influenced by different types of meditation.

Kinetics of acid hydrolysis and reactivity of some antibacterial hydrophilic iron(II) imino-complexes

NASA Astrophysics Data System (ADS)

Shaker, Ali Mohamed; Nassr, Lobna Abdel-Mohsen Ebaid; Adam, Mohamed Shaker Saied; Mohamed, Ibrahim Mohamed Abdelhalim

2015-05-01

Kinetic study of acid hydrolysis of some hydrophilic Fe(II) Schiff base amino acid complexes with antibacterial properties was performed using spectrophotometry. The Schiff base ligands were derived from sodium 2-hydroxybenzaldehyde-5-sulfonate and glycine, L-alanine, L-leucine, L-isoleucine, DL-methionine, DL-serine, or L-phenylalanine. The reaction was studied in aqueous media under conditions of pseudo-first order kinetics. Moreover, the acid hydrolysis was studied at different temperatures and the activation parameters were calculated. The general rate equation was suggested as follows: rate = k obs [Complex], where k obs = k 2 [H+]. The evaluated rate constants and activation parameters are consistent with the hydrophilicity of the investigated complexes.

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction

PubMed Central

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

2017-01-01

Abstract In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl2]·2H2O (1), [Co(L)Cl2(H2O)2] (2) and [Ni(L)Cl2(H2O)2] (3), having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1. The esterification of butanol gave butyl acetate with 100% selectivity. PMID:29491815

Rice tolerance to suboptimal low temperatures relies on the maintenance of the photosynthetic capacity.

PubMed

Gazquez, Ayelén; Vilas, Juan Manuel; Colman Lerner, Jorge Esteban; Maiale, Santiago Javier; Calzadilla, Pablo Ignacio; Menéndez, Ana Bernardina; Rodríguez, Andrés Alberto

2018-06-01

The purpose of this research was to identify differences between two contrasting rice cultivars in their response to suboptimal low temperatures stress. A transcriptomic analysis of the seedlings was performed and results were complemented with biochemical and physiological analyses. The microarray analysis showed downregulation of many genes related with PSII and particularly with the oxygen evolving complex in the sensitive cultivar IR50. Complementary studies indicated that the PSII performance, the degree of oxygen evolving complex coupling with the PSII core and net photosynthetic rate diminished in this cultivar in response to the stress. However, the tolerant cultivar Koshihikari was able to maintain its energy equilibrium by sustaining the photosynthetic capacity. The increase of oleic acid in Koshihikari could be related with membrane remodelling of the chloroplasts and hence contribute to tolerance. Overall, these results work as a ground for future analyses that look forward to characterize possible mechanisms to tolerate this stress. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Crystal Structure and Antitumor Activity of the Novel Zwitterionic Complex of tri-n-Butyltin(IV) with 2-Thiobarbituric Acid

PubMed Central

Balas, Vasilios I.; Hadjikakou, Sotiris K.; Hadjiliadis, Nick; Kourkoumelis, Nikolaos; Light, Mark E.; Hursthouse, Mike; Metsios, Apostolos K.; Karkabounas, Spyros

2008-01-01

A novel tri-n-butyl(IV) derivative of 2-thiobarbituric acid (HTBA) of formula [(n-Bu)3Sn(TBA) H2O] (1) has been synthesized and characterized by elemental analysis and 119Sn-NMR and FT-IR spectroscopic techniques. The crystal structure of complex 1 has been determined by single crystal X-ray diffraction analysis at 120(2) K. The geometry around Sn(IV) is trigonal bipyramidal. Three n-butyl groups and one oxygen atom from a deprotonated 2-thiobarbituric ligand are bonded to the metal center. The geometry is completed with one oxygen from a water molecule. Compound 1 exhibits potent, in vitro, cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat, polycyclic aromatic hydrocarbons (PAH, benzo[a]pyrene) carcinogenesis. In addition, the inhibition caused by 1, in the rate of lipoxygenase (LOX) catalyzed oxidation reaction of linoleic acid to hyperoxolinoleic acid, has been also kinetically and theoretically studied. The results are compared to that of cisplatin. PMID:18401456

A holistic approach to determine tree structural complexity based on laser scanning data and fractal analysis.

PubMed

Seidel, Dominik

2018-01-01

The three-dimensional forest structure affects many ecosystem functions and services provided by forests. As forests are made of trees it seems reasonable to approach their structure by investigating individual tree structure. Based on three-dimensional point clouds from laser scanning, a newly developed holistic approach is presented that enables to calculate the box dimension as a measure of structural complexity of individual trees using fractal analysis. It was found that the box dimension of trees was significantly different among the tested species, among trees belonging to the same species but exposed to different growing conditions (at gap vs. forest interior) or to different kinds of competition (intraspecific vs. interspecific). Furthermore, it was shown that the box dimension is positively related to the trees' growth rate. The box dimension was identified as an easy to calculate measure that integrates the effect of several external drivers of tree structure, such as competition strength and type, while simultaneously providing information on structure-related properties, like tree growth.

Systematic analysis of protein turnover in primary cells.

PubMed

Mathieson, Toby; Franken, Holger; Kosinski, Jan; Kurzawa, Nils; Zinn, Nico; Sweetman, Gavain; Poeckel, Daniel; Ratnu, Vikram S; Schramm, Maike; Becher, Isabelle; Steidel, Michael; Noh, Kyung-Min; Bergamini, Giovanna; Beck, Martin; Bantscheff, Marcus; Savitski, Mikhail M

2018-02-15

A better understanding of proteostasis in health and disease requires robust methods to determine protein half-lives. Here we improve the precision and accuracy of peptide ion intensity-based quantification, enabling more accurate protein turnover determination in non-dividing cells by dynamic SILAC-based proteomics. This approach allows exact determination of protein half-lives ranging from 10 to >1000 h. We identified 4000-6000 proteins in several non-dividing cell types, corresponding to 9699 unique protein identifications over the entire data set. We observed similar protein half-lives in B-cells, natural killer cells and monocytes, whereas hepatocytes and mouse embryonic neurons show substantial differences. Our data set extends and statistically validates the previous observation that subunits of protein complexes tend to have coherent turnover. Moreover, analysis of different proteasome and nuclear pore complex assemblies suggests that their turnover rate is architecture dependent. These results illustrate that our approach allows investigating protein turnover and its implications in various cell types.

Coherent transport and energy flow patterns in photosynthesis under incoherent excitation.

PubMed

Pelzer, Kenley M; Can, Tankut; Gray, Stephen K; Morr, Dirk K; Engel, Gregory S

2014-03-13

Long-lived coherences have been observed in photosynthetic complexes after laser excitation, inspiring new theories regarding the extreme quantum efficiency of photosynthetic energy transfer. Whether coherent (ballistic) transport occurs in nature and whether it improves photosynthetic efficiency remain topics of debate. Here, we use a nonequilibrium Green's function analysis to model exciton transport after excitation from an incoherent source (as opposed to coherent laser excitation). We find that even with an incoherent source, the rate of environmental dephasing strongly affects exciton transport efficiency, suggesting that the relationship between dephasing and efficiency is not an artifact of coherent excitation. The Green's function analysis provides a clear view of both the pattern of excitonic fluxes among chromophores and the multidirectionality of energy transfer that is a feature of coherent transport. We see that even in the presence of an incoherent source, transport occurs by qualitatively different mechanisms as dephasing increases. Our approach can be generalized to complex synthetic systems and may provide a new tool for optimizing synthetic light harvesting materials.

Structural Design and Monitoring Analysis of Foundation Pit Support in Yiwu Huishang Tiandi

NASA Astrophysics Data System (ADS)

Zhang, Chunsu

2017-08-01

Huishang Tiandi deep foundation pit in Yiwu is a two-story basement,which is located in the downtown area and adjacent to the city center main traffic trunk. The surrounding environment is too com-plex to slope. The excavation depth is large, the formation is weak and complex, and the groundwater level is high.In order to ensure the safety of the foundation wall and the surrounding environment, the deformation of the foundation pit support is strictly controlled, and the deformation and internal force of the foundation supporting structure and the surrounding building are monitored.The deformation law of the foundation pit is obtained through the analysis of the horizontal displacement, the deformation rate of the supporting struc-ture, the surrounding environment of the foundation pit and the internal force of the anchor cable. The relia-bility and rationality of the design of foundation pit support are verified. It is of reference value for the de-sign and construction of other deep foundation pit engineering in Yiwu area.

Recommended care adherence: improved by patient reminder letters but with potential attenuation by the healthcare process complexity.

PubMed

Zhang, Zhou; Fish, Jason

2012-01-01

American adults receive the recommended care just over half of the time for all recommended services. Many patient reminder strategies have attempted to increase the adherence rates for preventative and chronic disease management. However, there is a lack of data available in relation to adherence rates for symptom-specific recommended services and a lack of data identifying any contributions from the organisational structures to these adherence rates. To identify the efficacy and differences in patient reminder letter strategies on various categories of recommended services, as well as to analyse the relationship between a novel quantification of a healthcare system's process complexity with adherence rates. Retrospective cohort study analysing pilot data collected from an urban, academic healthcare provider utilising patient reminder letters. Adults attending one academic medical centre's outpatient practice from 2008 to 2009. Two reminder letters sent chronologically if the recommended care was not completed in the appropriate time frame. Adherence rates of each recommended service at baseline, after first and second reminder letters, and non-adherence rates despite the reminder letter intervention. Process flow complexity was calculated as a composite score combining elements of fastest time to complete routine order, number of different steps in routine order, number of departments involved, and number of sites patients visit. Patient adherence rates increased for all the recommended services after the first reminder letter. Preventative and Chronic Disease Management recommendations demonstrated additional moderate increases after the second reminder letter. Referrals and Radiologogy and Diagnostic Testing (acute, symptom specific) and Labs (acute and nonacute) demonstrated additional minimal adherence rate increases after the second reminder letter. Comparison of the process flow complexity demonstrated an inverse relationship between process complexity and adherence rates, particularly for non-acute orders. One reminder letter seemed to be sufficient for most recommended care. The complexity of the healthcare process may be an important predictive factor for patient adherence.

A new complexity measure for time series analysis and classification

NASA Astrophysics Data System (ADS)

Nagaraj, Nithin; Balasubramanian, Karthi; Dey, Sutirth

2013-07-01

Complexity measures are used in a number of applications including extraction of information from data such as ecological time series, detection of non-random structure in biomedical signals, testing of random number generators, language recognition and authorship attribution etc. Different complexity measures proposed in the literature like Shannon entropy, Relative entropy, Lempel-Ziv, Kolmogrov and Algorithmic complexity are mostly ineffective in analyzing short sequences that are further corrupted with noise. To address this problem, we propose a new complexity measure ETC and define it as the "Effort To Compress" the input sequence by a lossless compression algorithm. Here, we employ the lossless compression algorithm known as Non-Sequential Recursive Pair Substitution (NSRPS) and define ETC as the number of iterations needed for NSRPS to transform the input sequence to a constant sequence. We demonstrate the utility of ETC in two applications. ETC is shown to have better correlation with Lyapunov exponent than Shannon entropy even with relatively short and noisy time series. The measure also has a greater rate of success in automatic identification and classification of short noisy sequences, compared to entropy and a popular measure based on Lempel-Ziv compression (implemented by Gzip).

Triazolylidene-Iridium Complexes with a Pendant Pyridyl Group for Cooperative Metal-Ligand Induced Catalytic Dehydrogenation of Amines.

PubMed

Valencia, Marta; Pereira, Ana; Müller-Bunz, Helge; Belderraín, Tomás R; Pérez, Pedro J; Albrecht, Martin

2017-07-03

Two iridium(III) complexes containing a C,N-bidentate pyridyl-triazolylidene ligand were prepared that are structurally very similar but differ in their pendant substituent. Whereas complex 1 contains a non-coordinating pyridyl unit, complex 2 has a phenyl group on the triazolylidene substituent. The presence of the basic pyridyl unit has distinct effects on the catalytic activity of the complex in the oxidative dehydrogenation of benzylic amines, inducing generally higher rates, higher selectivity towards formation of imines versus secondary amines, and notable quantities of tertiary amines when compared to the phenyl-functionalized analogue. The role of the pyridyl functionality has been elucidated from a set of stoichiometric experiments, which demonstrate hydrogen bonding between the pendant pyridyl unit and the amine protons of the substrate. Such N pyr ⋅⋅⋅H-N interactions are demonstrated by X-ray diffraction analysis, 1 H NMR, and IR spectroscopy, and suggest a pathway of substrate bond-activation that involves concerted substrate binding through the Lewis acidic iridium center and the Lewis basic pyridyl site appended to the triazolylidene ligand, in agreement with ligand-metal cooperative substrate activation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantifying the complexity of medical research.

PubMed

Rodriguez-Esteban, Raul; Loging, William T

2013-11-15

A crucial phenomenon of our times is the diminishing marginal returns of investments in pharmaceutical research and development. A potential reason is that research into diseases is becoming increasingly complex, and thus more burdensome, for humans to handle. We sought to investigate whether we could measure research complexity by analyzing the published literature. Through the text mining of the publication record of multiple diseases, we have found that the complexity and novelty of disease research has been increasing over the years. Surprisingly, we have also found that research on diseases with higher publication rate does not possess greater complexity or novelty than that on less-studied diseases. We have also shown that the research produced about a disease can be seen as a differentiated area of knowledge within the wider biomedical research. For our analysis, we have conceptualized disease research as a parallel multi-agent search in which each scientific agent (a scientist) follows a search path based on a model of a disease. We have looked at trends in facts published for diseases, measured their diversity and turnover using the entropy measure and found similar patterns across disease areas. raul.rodriguez-esteban@roche.com.

Two supramolecular complexes based on polyoxometalates and Co-EDTA units via covalent connection or non-covalent interaction

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

Teng, Chunlin; Xiao, Hanxi; Cai, Qing

Two new 3D network organic-inorganic hybrid supramolecular complexes ([Na{sub 6}(CoEDTA){sub 2}(H{sub 2}O){sub 13}]·(H{sub 2}SiW{sub 12}O{sub 40})·xH{sub 2}O)n (1) and [CoH{sub 4}EDTA(H{sub 2}O)]{sub 2}(SiW{sub 12}O{sub 40})·15H{sub 2}O (2) (H{sub 4}EDTA=Ethylenediamine tetraacetic acid) have been successfully synthesized by solution method, and characterized by infrared spectrum (IR), thermogravimetric-differential thermal analysis (TG-DTA), cyclic voltammetry (CV) and single{sup −}crystal X-ray diffraction (XRD). Both of the complexes are the supramolecules, but with different liking mode, they are two representative models of supramolecule. complex (1) is a 3D infinite network supramolecular coordination polymer with a rare multi-metal sturcture of sodium-cobalt-containing, which is mainly linked through coordinate-covalent bonds.more » While complex (2) is normal supramolecule, which linked by non-covalent interactions, such as H-bonding interaction, electrostatic interaction and van der waals force. Both of complex (1) and (2) exhibit good catalytic activities for catalytic oxidation of methanol, when the initial concentration of methanol is 3.0 g m{sup −3}, flow rate is 10 mL min{sup −1}, and the quality of catalyst is 0.2 g, for complex (1) and complex (2) the maximum elimination rates of methanol are 85% (150 °C) and 92% (120 °C), respectively. - Graphical abstract: Two new organic-inorganic hybrid supramolecular complexes based on Co-EDTA, and Keggin polyanions have been successfully synthesized with different pH value by solution method. They are attributed to two representative models of supramolecule. Complex(1) is an infinite coordination polymer with a rare multi-metal sturcture of sodium-cobalt-containing, which is mainly linked through covalent bonds. Complex (2) is a normal supramolecule, which linked by non-covalent interactions of H-bonding interaction, electrostatic interaction and van der waals force. - Highlights: • Two supramolecules are linked by covalent or non-covalent interactions. • They are attributed to two representative models of supramolecule. • A rare multi-metal infinite supramolecular coordination polymer was formed. • They exhibit good catalytic activities for catalytic oxidation of methanol.« less

Electrochemical Reduction of CO 2 Catalyzed by Re(pyridine-oxazoline)(CO) 3 Cl Complexes

DOE PAGES

Nganga, John K.; Samanamu, Christian R.; Tanski, Joseph M.; ...

2017-03-09

In a series of rhenium tricarbonyl complexes coordinated by asymmetric diimine ligands containing a pyridine moiety bound to an oxazoline ring were synthesized, structurally and electrochemically characterized, and screened for CO 2 reduction ability. We reported complexes are of the type Re(N-N)(CO) 3Cl, with N-N = 2-(pyridin-2-yl)-4,5-dihydrooxazole (1), 5-methyl-2-(pyridin-2-yl)-4,5-dihydrooxazole (2), and 5-phenyl-2-(pyridin-2-yl)-4,5-dihydrooxazole (3). The electrocatalytic reduction of CO 2 by these complexes was observed in a variety of solvents and proceeds more quickly in acetonitrile than in dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). The analysis of the catalytic cycle for electrochemical CO 2 reduction by 1 in acetonitrile using densitymore » functional theory (DFT) supports the C–O bond cleavage step being the rate-determining step (RDS) (ΔG ‡ = 27.2 kcal mol –1). Furthermore, the dependency of the turnover frequencies (TOFs) on the donor number (DN) of the solvent also supports that C–O bond cleavage is the rate-determining step. Moreover, the calculations using explicit solvent molecules indicate that the solvent dependence likely arises from a protonation-first mechanism. Unlike other complexes derived from fac-Re(bpy)(CO) 3Cl (I; bpy = 2,2'-bipyridine), in which one of the pyridyl moieties in the bpy ligand is replaced by another imine, no catalytic enhancement occurs during the first reduction potential. Remarkably, catalysts 1 and 2 display relative turnover frequencies, (i cat/i p) 2, up to 7 times larger than that of I.« less

Retrievals of Surface Air Temperature Using Multiple Satellite Data Combinations over Complex Terrain in the Korean Peninsula

NASA Astrophysics Data System (ADS)

Jang, K.; Won, M.; Yoon, S.; Lim, J.

2016-12-01

Surface air temperature (Tair) is a fundamental factor for terrestrial environments and plays a major role in the fields of applied meteorology, climatology, and ecology. The satellite remotely sensed data offers the opportunity to estimate Tair on the earth's surface with high spatial and temporal resolutions. The Moderate Resolution Imaging Spectroradiometer (MODIS) provides effective Tair retrievals although restricted to clear sky condition. MODIS Tair over complex terrain can result in significant retrieval errors due to the retrieval height mismatch to the elevation of local weather stations. In this study, we propose the methodology to estimate Tair over complex terrain for all sky conditions using multiple satellite data fusion based on the pixel-wise regression method. The combination of synergistic information from MODIS Tair and the brightness temperature (Tb) retrievals at 37 GHz frequency from the satellite microwave sensor were used for analysis. The air temperature lapse rate was applied to estimate the near-surface Tair considering the complex terrain such as mountainous regions. The retrieval results produced from this study showed a good agreement (RMSE < 2.5 K) with weather measurements from the Korea Forest Service (KFS) for mountain regions and the Korea Meteorology Administration (KMA). The gaps in the MODIS Tair data due to cloud contamination were successfully filled using the proposed method which yielded similar accuracy as retrievals of clear sky. The results of this study indicate that the satellite data fusion can continuously produce Tair retrievals with reasonable accuracy and that the application of the temperature lapse rate can lead to improvement of the reliability over complex terrains such as the Korean Peninsula.

Deuterium kinetic isotope effects on the dissociation of a protein-fatty acid complex in the gas phase.

PubMed

Liu, Lan; Michelsen, Klaus; Kitova, Elena N; Schnier, Paul D; Brown, Alex; Klassen, John S

2012-04-04

Deuterium kinetic isotope effects (KIEs) are reported for the first time for the dissociation of a protein-ligand complex in the gas phase. Temperature-dependent rate constants were measured for the loss of neutral ligand from the deprotonated ions of the 1:1 complex of bovine β-lactoglobulin (Lg) and palmitic acid (PA), (Lg + PA)(n-) → Lg(n-) + PA, at the 6- and 7- charge states. At 25 °C, partial or complete deuteration of the acyl chain of PA results in a measurable inverse KIE for both charge states. The magnitude of the KIEs is temperature dependent, and Arrhenius analysis of the rate constants reveals that deuteration of PA results in a decrease in activation energy. In contrast, there is no measurable deuterium KIE for the dissociation of the (Lg + PA) complex in aqueous solution at pH 8. Deuterium KIEs were calculated using conventional transition-state theory with an assumption of a late dissociative transition state (TS), in which the ligand is free of the binding pocket. The vibrational frequencies of deuterated and non-deuterated PA in the gas phase and in various solvents (n-hexane, 1-chlorohexane, acetone, and water) were established computationally. The KIEs calculated from the corresponding differences in zero-point energies account qualitatively for the observation of an inverse KIE but do not account for the magnitude of the KIEs nor their temperature dependence. It is proposed that the dissociation of the (Lg + PA) complex in aqueous solution also proceeds through a late TS in which the acyl chain is extensively hydrated such that there is no significant differential change in the vibrational frequencies along the reaction coordinate and, consequently, no significant KIE.

Flattening of Caribbean coral reefs: region-wide declines in architectural complexity

PubMed Central

Alvarez-Filip, Lorenzo; Dulvy, Nicholas K.; Gill, Jennifer A.; Côté, Isabelle M.; Watkinson, Andrew R.

2009-01-01

Coral reefs are rich in biodiversity, in large part because their highly complex architecture provides shelter and resources for a wide range of organisms. Recent rapid declines in hard coral cover have occurred across the Caribbean region, but the concomitant consequences for reef architecture have not been quantified on a large scale to date. We provide, to our knowledge, the first region-wide analysis of changes in reef architectural complexity, using nearly 500 surveys across 200 reefs, between 1969 and 2008. The architectural complexity of Caribbean reefs has declined nonlinearly with the near disappearance of the most complex reefs over the last 40 years. The flattening of Caribbean reefs was apparent by the early 1980s, followed by a period of stasis between 1985 and 1998 and then a resumption of the decline in complexity to the present. Rates of loss are similar on shallow (<6 m), mid-water (6–20 m) and deep (>20 m) reefs and are consistent across all five subregions. The temporal pattern of declining architecture coincides with key events in recent Caribbean ecological history: the loss of structurally complex Acropora corals, the mass mortality of the grazing urchin Diadema antillarum and the 1998 El Nino Southern Oscillation-induced worldwide coral bleaching event. The consistently low estimates of current architectural complexity suggest regional-scale degradation and homogenization of reef structure. The widespread loss of architectural complexity is likely to have serious consequences for reef biodiversity, ecosystem functioning and associated environmental services. PMID:19515663

Functional Regression Models for Epistasis Analysis of Multiple Quantitative Traits.

PubMed

Zhang, Futao; Xie, Dan; Liang, Meimei; Xiong, Momiao

2016-04-01

To date, most genetic analyses of phenotypes have focused on analyzing single traits or analyzing each phenotype independently. However, joint epistasis analysis of multiple complementary traits will increase statistical power and improve our understanding of the complicated genetic structure of the complex diseases. Despite their importance in uncovering the genetic structure of complex traits, the statistical methods for identifying epistasis in multiple phenotypes remains fundamentally unexplored. To fill this gap, we formulate a test for interaction between two genes in multiple quantitative trait analysis as a multiple functional regression (MFRG) in which the genotype functions (genetic variant profiles) are defined as a function of the genomic position of the genetic variants. We use large-scale simulations to calculate Type I error rates for testing interaction between two genes with multiple phenotypes and to compare the power with multivariate pairwise interaction analysis and single trait interaction analysis by a single variate functional regression model. To further evaluate performance, the MFRG for epistasis analysis is applied to five phenotypes of exome sequence data from the NHLBI's Exome Sequencing Project (ESP) to detect pleiotropic epistasis. A total of 267 pairs of genes that formed a genetic interaction network showed significant evidence of epistasis influencing five traits. The results demonstrate that the joint interaction analysis of multiple phenotypes has a much higher power to detect interaction than the interaction analysis of a single trait and may open a new direction to fully uncovering the genetic structure of multiple phenotypes.

Dynamic NMR study of ethene exchange in cationic CNN-type platinum(II) complexes.

PubMed

Plutino, M Rosaria; Fenech, Lucia; Stoccoro, Sergio; Rizzato, Silvia; Castellano, Carlo; Albinati, Alberto

2010-01-18

Cationic ethylene platinum(II) complexes of the type [Pt(CNN)(C(2)H(4))](+), containing a methyl fragment and different diimines (NN), or terdentate (kappaC-kappa(2)NN') anionic ligands, were synthesized and fully characterized both as solids and in solution [NN = 2,2'-dipyridylamine, 1; 2,2'-dipyridylsulfide, 2; 1,10-phenanthroline, 3; 4,7-diphenyl-1,10-phenanthroline, 4; 3,4,7,8-tetramethyl-1,10-phenanthroline, 5; 2,2'-bipyridine, 6; HC-NN = 6-tert-butyl-2,2'-bipyridine, 7; 6-neo-pentyl-2,2'-bipyridine, 8; 6-phenyl-2,2'-bipyridine, 9; 6-(alpha-methyl)benzyl-2,2'-bipyridine, 10; 6-(alpha-ethyl)benzyl-2,2'-bipyridine, 11; 6-(alpha,alpha-dimethyl)benzyl-2,2'-bipyridine, 12]. Crystals suitable for X-ray analysis of complexes 5 and 7 were obtained. Ethene exchange at the cyclometalated platinum(II) complexes 7, 8, and 10-12 was studied by (1)H NMR line-broadening experiments in chloroform-d, as a function of both temperature and olefin concentrations. For the other prepared complexes the process was too fast to be monitored on the NMR time scale even at the lowest temperature. The ethylene exchange rates show a linear dependence on the concentration of the free ligand, with a negligible k(1) term indicating that either a solvolytic or a dissociative pathway to the products is absent or negligible. The values of the second-order rate constants k(exc), as obtained by linear regression analysis of the experimental data at 298 K, are in a range of ca. 10(4)-10(5) s(-1) m(-1). The activation entropies are negative, ranging between -129 and -112 J K(-1) mol(-1), as expected for associative processes. The activation process is largely entropy controlled: the TDeltaS()() contribution to the free energy of activation is extremely large, amounting to more than 80% for all complexes, with a smaller enthalpy contribution. All the experimental findings evidence that the mechanism takes place via an associative attack by the entering olefin, through a well-ordered, stable pentacoordinated transition state with the two ethene molecules on the trigonal plane. The reactivity of [Pt(CNN)(C(2)H(4))](+) complexes is strongly dependent on the choice of coordinated 6-substituted-2,2'-bipyridines, especially when the terdentate anionic fragment is capable of generating steric crowding and congestion on the coordination plane.

Information Transfer Analysis of Spontaneous Low-frequency Fluctuations in Cerebral Hemodynamics and Cardiovascular Dynamics

NASA Astrophysics Data System (ADS)

Katura, Takusige; Tanaka, Naoki; Obata, Akiko; Sato, Hiroki; Maki, Atsushi

2005-08-01

In this study, from the information-theoretic viewpoint, we analyzed the interrelation between the spontaneous low-frequency fluctuations around 0.1Hz in the hemoglobin concentration in the cerebral cortex, mean arterial blood pressure and the heart rate. For this analysis, as measures of information transfer, we used transfer entropy (TE) proposed for two-factor systems by Schreiber and intrinsic transfer entropy (ITE) introduced for further analysis of three-factor systems by extending the original TE. In our analysis, information transfer analysis based on both TE and ITE suggests the systemic cardiovascular fluctuations alone cannot account for the cerebrovascular fluctuations, that is, the regulation of the regional cerebral energetic metabolism is important as a candidate of its generation mechanism Such an information transfer analysis seems useful to reveal the interrelation between the elements regulated each other in a complex manner.

Hybrid Structure White Organic Light Emitting Diode for Enhanced Efficiency by Varied Doping Rate.

PubMed

Kim, Dong-Eun; Kang, Min-Jae; Park, Gwang-Ryeol; Kim, Nam-Kyu; Lee, Burm-Jong; Kwon, Young-Soo; Shin, Hoon-Kyu

2016-03-01

Novel materials based on Zn(HPB)2 and Ir-complexes were synthesized as blue or red emitters, respectively. White organic light emitting diodes were fabricated using the Zn(HPB)2 as a blue emitting layer, Ir-complexes as a red emitting layer and Alq3 as a green emitting layer. The obtained experimental results, were based on white OLEDs fabricated using double emission layers of Zn(HPB)2 and Alq3:Ir-complexes. The doping rate of the Ir-complexes was varied at 0.4%, 0.6%, 0.8% and 1.0%. When the doping rate of the Alq3:Ir-complexes was 0.6%, a white emission was achieved. The Commission Internationale de l'Eclairage coordinates of the device's white emission were (0.316, 0.331) at an applied voltage of 10.75 V.

Pressure dependence of carbonate exchange with [NpO 2(CO 3) 3] 4– in aqueous solutions

DOE PAGES

Pilgrim, Corey D.; Zavarin, Mavrik; Casey, William H.

2016-12-13

Here, the rates of ligand exchange into the geochemically important [NpO 2(CO 3) 3] 4– aqueous complex are measured as a function of pressure in order to complement existing data on the isostructural [UO 2(CO 3) 3] 4– complex. Experiments are conducted at pH conditions where the rate of exchange is independent of the proton concentration. Unexpectedly, the experiments show a distinct difference in the pressure dependencies of rates of exchange for the uranyl and neptunyl complexes.

Water soluble biocompatible vesicles based on polysaccharides and oligosaccharides inclusion complexes for carotenoid delivery.

PubMed

Polyakov, Nikolay E; Kispert, Lowell D

2015-09-05

Since carotenoids are highly hydrophobic, air- and light-sensitive hydrocarbon compounds, developing methods for increasing their bioavailability and stability towards irradiation and reactive oxygen species is an important goal. Application of inclusion complexes of "host-guest" type with polysaccharides and oligosaccharides such as arabinogalactan, cyclodextrins and glycyrrhizin minimizes the disadvantages of carotenoids when these compounds are used in food processing (colors and antioxidant capacity) as well as for production of therapeutic formulations. Cyclodextrin complexes which have been used demonstrated enhanced storage stability but suffered from poor solubility. Polysaccharide and oligosaccharide based inclusion complexes play an important role in pharmacology by providing increased solubility and stability of lipophilic drugs. In addition they are used as drug delivery systems to increase absorption rate and bioavailability of the drugs. In this review we summarize the existing data on preparation methods, analysis, and chemical reactivity of carotenoids in inclusion complexes with cyclodextrin, arabinogalactan and glycyrrhizin. It was demonstrated that incorporation of carotenoids into the "host" macromolecule results in significant changes in their physical and chemical properties. In particular, polysaccharide complexes show enhanced photostability of carotenoids in water solutions. A significant decrease in the reactivity towards metal ions and reactive oxygen species in solution was also detected. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design and Demonstration of Automated Data Analysis Algorithms for Ultrasonic Inspection of Complex Composite Panels with Bonds

DTIC Science & Technology

2016-02-01

certification process. INTRODUCTION The ultrasonic inspection of aerospace composites has been demonstrated to be one of the most effective methods to...normal part conditions. Anomalous indications studied in this program include inserted materials, porosity, ply ‘laps and gaps’, and wrinkles . Inserted...partially scanned inserts at the radii. Wrinkles , laps and gaps have also been included in the truth table, but detection rates for these flaws are

Development, Verification and Experimental Analysis of High-Fidelity Mathematical Models for Control Moment Gyros

DTIC Science & Technology

2011-12-01

therefore a more general approach uses the pseudo-inverse shown in Equation (12) to obtain the commanded gimbal rate.     1 /T T b N CMG...gimbal motor. Approaching the problem from this perspective increases the complexity significantly and the relationship between motor current and...included in this document confirms the equations that Schaub and Junkins developed. The approaches used in the two derivations are sufficiently

Tracking Central Hypovolemia with ECG in Humans: Cautions for the Use of Heart Period Variability in Patient Monitoring

DTIC Science & Technology

2010-06-01

without influences that may confound the re- sults (e.g., pain, anxiety , transport conditions, caregiver in- terventions). Second, rather than being...32. Ryan KL, Rickards CA, Muniz GW, Moralez G, Convertino VA: Interindi- vidual variability in heart rate variability ( HRV ) and complexity measure...Raimondi G, Legramante JM, Macerata A: Revisiting the potential of time-domain indexes in short-term HRV analysis. Biomed Tech (Berl) 51:190Y193, 2006

Heat transfer correlations for multilayer insulation systems

NASA Astrophysics Data System (ADS)

Krishnaprakas, C. K.; Badari Narayana, K.; Dutta, Pradip

2000-01-01

Multilayer insulation (MLI) blankets are extensively used in spacecrafts as lightweight thermal protection systems. Heat transfer analysis of MLI is sometimes too complex to use in practical design applications. Hence, for practical engineering design purposes, it is necessary to have simpler procedures to evaluate the heat transfer rate through MLI. In this paper, four different empirical models for heat transfer are evaluated by fitting against experimentally observed heat flux through MLI blankets of various configurations, and the results are discussed.

Epidemic spreading in time-varying community networks.

PubMed

Ren, Guangming; Wang, Xingyuan

2014-06-01

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q < qc. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

Visibility graph analysis of very short-term heart rate variability during sleep

NASA Astrophysics Data System (ADS)

Hou, F. Z.; Li, F. W.; Wang, J.; Yan, F. R.

2016-09-01

Based on a visibility-graph algorithm, complex networks were constructed from very short-term heart rate variability (HRV) during different sleep stages. Network measurements progressively changed from rapid eye movement (REM) sleep to light sleep and then deep sleep, exhibiting promising ability for sleep assessment. Abnormal activation of the cardiovascular controls with enhanced 'small-world' couplings and altered fractal organization during REM sleep indicates that REM could be a potential risk factor for adverse cardiovascular event, especially in males, older individuals, and people who are overweight. Additionally, an apparent influence of gender, aging, and obesity on sleep was demonstrated in healthy adults, which may be helpful for establishing expected sleep-HRV patterns in different populations.

Structure of turbulent non-premixed flames modeled with two-step chemistry

NASA Technical Reports Server (NTRS)

Chen, J. H.; Mahalingam, S.; Puri, I. K.; Vervisch, L.

1992-01-01

Direct numerical simulations of turbulent diffusion flames modeled with finite-rate, two-step chemistry, A + B yields I, A + I yields P, were carried out. A detailed analysis of the turbulent flame structure reveals the complex nature of the penetration of various reactive species across two reaction zones in mixture fraction space. Due to this two zone structure, these flames were found to be robust, resisting extinction over the parameter ranges investigated. As in single-step computations, mixture fraction dissipation rate and the mixture fraction were found to be statistically correlated. Simulations involving unequal molecular diffusivities suggest that the small scale mixing process and, hence, the turbulent flame structure is sensitive to the Schmidt number.

[Definite of nutritional status in patients with metabolic syndrome with the use of modern methods of nutrimetabolomica].

PubMed

Viskunova, A A; Kaganov, B S; Sharafetdinov, Kh Kh; Plotnikova, O A; Pogozheva, A V; Vorozhko, I V

2010-01-01

A comprehensive assessment of nutritional status in 73 patients with metabolic syndrome was assessed. The consumption food pattern of the majority of examined patients have had increased energy intake with excessive fat consumption inadequate intake of complex carbohydrates. In patients with type 2 diabetes inadequate compensation of carbohydrate and lipid metabolism was marked. When assessing body composition method bioelectrical impedance analysis increased content of adipose tissue was revealed are positively correlated with insulin and tumor necrosis factor-alpha. According to indirect calorimetry, increase in the level of resting energy expenditure, reducing the rate of oxidation of fat, increase the rate of oxidation of protein and carbohydrates was noted.

Dairy herd mastitis and reproduction: using simulation to aid interpretation of results from discrete time survival analysis.

PubMed

Hudson, Christopher D; Bradley, Andrew J; Breen, James E; Green, Martin J

2015-04-01

Probabilistic sensitivity analysis (PSA) is a simulation-based technique for evaluating the relative importance of different inputs to a complex process model. It is commonly employed in decision analysis and for evaluation of the potential impact of uncertainty in research findings on clinical practice, but has a wide variety of other possible applications. In this example, it was used to evaluate the association between herd-level udder health and reproductive performance in dairy herds. Although several recent studies have found relatively large associations between mastitis and fertility at the level of individual inseminations or lactations, the current study demonstrated that herd-level intramammary infection status is highly unlikely to have a clinically significant impact on the overall reproductive performance of a dairy herd under typical conditions. For example, a large increase in incidence rate of clinical mastitis (from 92 to 131 cases per 100 cows per year) would be expected to increase a herd's modified FERTEX score (a cost-based measure of overall reproductive performance) by just £4.50(1) per cow per year. The herd's background level of submission rate (proportion of eligible cows served every 21 days) and pregnancy risk (proportion of inseminations leading to a pregnancy) correlated strongly with overall reproductive performance and explained a large proportion of the between-herd variation in performance. PSA proved to be a highly useful technique to aid understanding of results from a complex statistical model, and has great potential for a wide variety of applications within the field of veterinary science. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits.

PubMed

Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U

2016-01-01

One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants' personality traits as described in the 'Big Five Inventory' (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits.

Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits

PubMed Central

Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U.

2016-01-01

One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants’ personality traits as described in the ‘Big Five Inventory’ (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits. PMID:27445933