Initiation and continuation of long-acting reversible contraception in the United States military healthcare system.

PubMed

Chiles, Daniel P; Roberts, Timothy A; Klein, David A

2016-09-01

Long-acting reversible contraception is more effective for pregnancy prevention than shorter-acting contraceptive methods and has the potential to reduce healthcare disparities and costs. However, long-acting reversible contraception is underused in the United States. One population of interest is beneficiaries of the United States military healthcare system who have access to universal healthcare, including no-cost, no-copay contraception with unlimited method switching, and comprise a large, actual use cohort. Efforts to increase long-acting reversible contraception initiation and continuation in this population may improve health outcomes and mitigate the profound consequences of unintended or mistimed pregnancy on readiness and cost to the military. We aimed to determine long-acting reversible contraception initiation and continuation rates among the diverse population with universal healthcare who are enrolled in the US military healthcare system. This study is a retrospective cohort of >1.7 million women, aged 14-40 years, who were enrolled in the US military healthcare system, TRICARE Prime, between October 2009 and September 2014. Individuals were assessed for long-acting reversible contraception initiation and continuation with the use of medical billing records. Method continuation and factors that were associated with early method discontinuation were evaluated with the Kaplan-Meier estimator and Cox proportional hazard models. During the study dates, 188,533 women initiated long-acting reversible contraception. Of these, 74.6% women selected intrauterine contraceptives. Method initiation rates remained relatively stable (41.7-50.1/1000 women/year) for intrauterine methods, although the rate for subdermal implants increased from 6.1-23.0/1000 women/year. In analysis of women who selected intrauterine contraceptives, 61.2% continued their method at 36 months, and 48.8% continued at 60 months. Among women who selected the implant, 32.0% continued their method at 36 months; however, 45.8% continued until 33 months (ie, 3 months before the currently recommended expiration date). Compared with intrauterine contraceptive users, implant users were more likely to discontinue their method during the 36 months after insertion (hazard ratio, 1.59; 95% confidence interval, 1.56-1.62; P < .001). Adolescents aged 14-19 years were the least likely age group to discontinue the implant before 36 months; women aged 35-40 years were the least likely to discontinue an intrauterine contraceptive before 60 months. In multivariable analysis that controlled for demographic factors and contraceptive type, early contraceptive method discontinuation was most likely among women aged 20-24 years, implant users, and women with method initiation in military clinics. In the US military healthcare system, TRICARE Prime, the initiation of long-acting reversible contraception is low but increasing, and continuation rates are high. This evidence supports long-acting reversible contraception as first-line recommendations for women of all ages who seek contraception. Published by Elsevier Inc.

CRADA No. BNL-C-97-10 between BNL and Cotton, Inc. Final abstract and final report [Final Report of Research carried out under DOE CRADA No. BNL-C-97-10 - "Prediction of Yield in Cotton"

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

None, None

The objectives of this work were to determine if the numbér of fiber cell initials varied genetically and to compare the number of initials with that of mature fibers obtained at harvest time. The method used to count the number of fiber cell initials is direct, simple, quick and done while the plant is growing. In contrast, the currently used commercial process is indirect and needs large amount mature fibers gathered at harvest time. However, all current work on cotton yield is based on fiber numbers obtained by the indirect commercial process. Consequently, it was necessary to compare results obtainedmore » from the two methods using the same plants as the source of material. The results show that the number of fiber initials per ovule differed significantly (P>0.05) for seven cultivars in 1995 and 1996. AIso, a 1997 study shows the number of fiber initials varied by 15% over boll positions and environments, with rankings among cultivars generally consistent across boll positions and sampling times. Finally, although there were differences among cultivars for initial fiber cell number, all cultivars had nearly the same number of mature lint fibers per seed. This last finding is significant. It indicates that the rate of fiber cell initiation varies among cultivars; the lower the rate, the greater the difference between the number of initials and the number of mature fiber cells. If the rate of fiber initiation is relatively high, the number of initials and mature fibers differs by about 11%; if it is low, the difference is as high as 31%. Cotton breeders may be able to use genetic differences for the number of fiber initials and/or the rate of fiber cell initiation in crop improvement programs.« less

Survey Methods to Optimize Response Rate in the National Dental Practice-Based Research Network.

PubMed

Funkhouser, Ellen; Vellala, Kavya; Baltuck, Camille; Cacciato, Rita; Durand, Emily; McEdward, Deborah; Sowell, Ellen; Theisen, Sarah E; Gilbert, Gregg H

2017-09-01

Surveys of health professionals typically have low response rates, and these rates have been decreasing in the recent years. We report on the methods used in a successful survey of dentist members of the National Dental Practice-Based Research Network. The objectives were to quantify the (1) increase in response rate associated with successive survey methods, (2) time to completion with each successive step, (3) contribution from the final method and personal contact, and (4) differences in response rate and mode of response by practice/practitioner characteristics. Dentist members of the network were mailed an invitation describing the study. Subsequently, up to six recruitment steps were followed: initial e-mail, two e-mail reminders at 2-week intervals, a third e-mail reminder with postal mailing a paper questionnaire, a second postal mailing of paper questionnaire, and staff follow-up. Of the 1,876 invited, 160 were deemed ineligible and 1,488 (87% of 1,716 eligible) completed the survey. Completion by step: initial e-mail, 35%; second e-mail, 15%; third e-mail, 7%; fourth e-mail/first paper, 11%; second paper, 15%; and staff follow-up, 16%. Overall, 76% completed the survey online and 24% on paper. Completion rates increased in absolute numbers and proportionally with later methods of recruitment. Participation rates varied little by practice/practitioner characteristics. Completion on paper was more likely by older dentists. Multiple methods of recruitment resulted in a high participation rate: Each step and method produced incremental increases with the final step producing the largest increase.

Simplified Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2005-01-01

A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two time step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting rates of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx are obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3). The temperature of the gas entering the turbine (T4) was also correlated as a function of the initial combustor temperature (T3), equivalence ratio, water to fuel mass ratio, and pressure.

Typewriting: The Sight Method of Teaching Typewriting

ERIC Educational Resources Information Center

Ruddle, Eleanor S.

1970-01-01

Research with beginning typewriting students supports the use of the sight method-looking at the fingers and keyboard during the initial learning stages. The sight method increases the rate and degree of accuracy. (CH)

Syringe Pump Performance Maintained with IV Filter Use During Low Flow Rate Delivery for Pediatric Patients.

PubMed

Chau, Destiny F; Vasilopoulos, Terrie; Schoepf, Miriam; Zhang, Christina; Fahy, Brenda G

2016-09-01

Complex surgical and critically ill pediatric patients rely on syringe infusion pumps for precise delivery of IV medications. Low flow rates and in-line IV filter use may affect drug delivery. To determine the effects of an in-line filter to remove air and/or contaminants on syringe pump performance at low flow rates, we compared the measured rates with the programmed flow rates with and without in-line IV filters. Standardized IV infusion assemblies with and without IV filters (filter and control groups) attached to a 10-mL syringe were primed and then loaded onto a syringe pump and connected to a 16-gauge, 16-cm single-lumen catheter. The catheter was suspended in a normal saline fluid column to simulate the back pressure from central venous circulation. The delivered infusate was measured by gravimetric methods at predetermined time intervals, and flow rate was calculated. Experimental trials for initial programmed rates of 1.0, 0.8, 0.6, and 0.4 mL/h were performed in control and filter groups. For each trial, the flow rate was changed to double the initial flow rate and was then returned to the initial flow rate to analyze pump performance for titration of rates often required during medication administration. These conditions (initial rate, doubling of initial rate, and return to initial rate) were analyzed separately for steady-state flow rate and time to steady state, whereas their average was used for percent deviation analysis. Differences between control and filter groups were assessed using Student t tests with adjustment for multiplicity (using n = 3 replications per group). Mean time from 0 to initial flow (startup delay) was <1 minute in both groups with no statistical difference between groups (P = 1.0). The average time to reach steady-state flow after infusion startup or rate changes was not statistically different between the groups (range, 0.8-5.5 minutes), for any flow rate or part of the trial (initial rate, doubling of initial rate, and return to initial rate), although the study was underpowered to detect small time differences. Overall, the mean steady-state flow rate for each trial was below the programmed flow rate with negative mean percent deviations for each trial. In the 1.0-mL/h initial rate trial, the steady-state flow rate attained was lower in the filter than the control group for the initial rate (P = 0.04) and doubling of initial rate (P = 0.04) with a trend during the return to initial rate (P = 0.06), although this same effect was not observed when doubling the initial rate trials of 0.8 or 0.6 mL/h or any other rate trials compared with the control group. With low flow rates used in complex surgical and pediatric critically ill patients, the addition of IV filters did not confer statistically significant changes in startup delay, flow variability, or time to reach steady-state flow of medications administered by syringe infusion pumps. The overall flow rate was lower than programmed flow rate with or without a filter.

Hierarchical Leak Detection and Localization Method in Natural Gas Pipeline Monitoring Sensor Networks

PubMed Central

Wan, Jiangwen; Yu, Yang; Wu, Yinfeng; Feng, Renjian; Yu, Ning

2012-01-01

In light of the problems of low recognition efficiency, high false rates and poor localization accuracy in traditional pipeline security detection technology, this paper proposes a type of hierarchical leak detection and localization method for use in natural gas pipeline monitoring sensor networks. In the signal preprocessing phase, original monitoring signals are dealt with by wavelet transform technology to extract the single mode signals as well as characteristic parameters. In the initial recognition phase, a multi-classifier model based on SVM is constructed and characteristic parameters are sent as input vectors to the multi-classifier for initial recognition. In the final decision phase, an improved evidence combination rule is designed to integrate initial recognition results for final decisions. Furthermore, a weighted average localization algorithm based on time difference of arrival is introduced for determining the leak point’s position. Experimental results illustrate that this hierarchical pipeline leak detection and localization method could effectively improve the accuracy of the leak point localization and reduce the undetected rate as well as false alarm rate. PMID:22368464

Hierarchical leak detection and localization method in natural gas pipeline monitoring sensor networks.

PubMed

Wan, Jiangwen; Yu, Yang; Wu, Yinfeng; Feng, Renjian; Yu, Ning

2012-01-01

In light of the problems of low recognition efficiency, high false rates and poor localization accuracy in traditional pipeline security detection technology, this paper proposes a type of hierarchical leak detection and localization method for use in natural gas pipeline monitoring sensor networks. In the signal preprocessing phase, original monitoring signals are dealt with by wavelet transform technology to extract the single mode signals as well as characteristic parameters. In the initial recognition phase, a multi-classifier model based on SVM is constructed and characteristic parameters are sent as input vectors to the multi-classifier for initial recognition. In the final decision phase, an improved evidence combination rule is designed to integrate initial recognition results for final decisions. Furthermore, a weighted average localization algorithm based on time difference of arrival is introduced for determining the leak point's position. Experimental results illustrate that this hierarchical pipeline leak detection and localization method could effectively improve the accuracy of the leak point localization and reduce the undetected rate as well as false alarm rate.

Chlamydia testing and diagnosis following initiation of long-acting reversible contraception: A retrospective cohort study.

PubMed

Rose, Sally B; Garrett, Susan M; Stanley, James; Pullon, Susan R H

2017-12-01

Long-acting reversible contraception (LARC) effectively protects against pregnancy but provides no protection against sexually transmitted infections (STIs). To compare rates of chlamydia testing and diagnosis for women initiating long-acting versus oral contraception. Retrospective cohort study involving data collection for 6160 women initiating post-abortion contraception at a large New Zealand regional public hospital abortion clinic (2009-2012), with chlamydia testing data obtained from the local laboratory during two-year follow up. Negative binomial regression modelling examined the effect of contraceptive method on two outcome measures: chlamydia testing and chlamydia diagnosis (adjusting for potential covariates of age, ethnicity, past chlamydia infection, pregnancy history) in year one and two of follow up. Two thousand seven hundred and twenty nine women (44%) received a LARC and 1764 (28.6%) were prescribed oral contraception. Adjusted testing rates differed by contraceptive method only in year one (P < 0.01): with higher rates among copper intrauterine device users (relative risk (RR) 1.2, 95% CI 1.06-1.35), and lower rates for implant users (RR 0.84, 95% CI 0.72-0.99) compared with oral contraceptive users (reference group). No significant differences were observed in chlamydia diagnosis rates by contraceptive method (P > 0.05). Younger age, past chlamydia infection, Maori and Pacific ethnicity were associated with higher rates of chlamydia diagnosis (P < 0.01). Known STI-related risk factors (age, ethnicity, past infection) but not contraceptive method were independently related to rates of subsequent chlamydia diagnosis. This suggests that increased LARC uptake would not occur at the expense of chlamydia control. Regular screening and risk reduction advice (including condom use) are important chlamydia control measures for at-risk groups. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Analytical Method of Approximating the Motion of a Spinning Vehicle with Variable Mass and Inertia Properties Acted Upon by Several Disturbing Parameters

NASA Technical Reports Server (NTRS)

Buglia, James J.; Young, George R.; Timmons, Jesse D.; Brinkworth, Helen S.

1961-01-01

An analytical method has been developed which approximates the dispersion of a spinning symmetrical body in a vacuum, with time-varying mass and inertia characteristics, under the action of several external disturbances-initial pitching rate, thrust misalignment, and dynamic unbalance. The ratio of the roll inertia to the pitch or yaw inertia is assumed constant. Spin was found to be very effective in reducing the dispersion due to an initial pitch rate or thrust misalignment, but was completely Ineffective in reducing the dispersion of a dynamically unbalanced body.

DON'T BE TRICKED BY YOUR INTEGRATED RATE PLOT!

EPA Science Inventory

Reaction order can be determined from kinetic data in a variety of ways. Two methods commonly employed are comparison of initial rates (while varying reactant concentration) and plotting integrated rate expressions. Both of these are introduced in general and physical chemistry t...

Initiation of Farm Safety Programs in the Arkansas Delta: A Case Study of Participatory Methods

ERIC Educational Resources Information Center

Richter, Jan S.; Hall, Becky G.; Deere, G. David

2007-01-01

Context: Outreach to high-risk communities is one of the goals of Area Health Education Centers. One such population is the farm community, which is known to suffer high rates of traumatic events. Purpose: To describe a participatory methods initiative by the Arkansas Delta Area Health Education Center and other agencies to address farm-related…

Initial-boundary layer associated with the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq system

NASA Astrophysics Data System (ADS)

Fei, Mingwen; Han, Daozhi; Wang, Xiaoming

2017-01-01

In this paper, we study the vanishing Darcy number limit of the nonlinear Darcy-Brinkman-Oberbeck-Boussinesq system (DBOB). This singular perturbation problem involves singular structures both in time and in space giving rise to initial layers, boundary layers and initial-boundary layers. We construct an approximate solution to the DBOB system by the method of multiple scale expansions. The convergence with optimal convergence rates in certain Sobolev norms is established rigorously via the energy method.

The course of early disinhibited social engagement among post-institutionalized adopted children

PubMed Central

Lawler, Jamie M.; Koss, Kalsea J.; Doyle, Colleen M.; Gunnar, Megan R.

2016-01-01

Background Approximately 20% of post-institutionalized (PI) children exhibit disinhibited social engagement (DSE) or the propensity to approach and engage strangers. There is little longitudinal research examining changes in DSE after adoption, or methods of identifying children with persistent behaviors. Methods DSE was assessed observationally four times during the first two years post-adoption in PI children 16-36 months at adoption (n=68) relative to same-age non-adopted children (n=52). At age 5, a validated interview determined which PI children met criteria for Disinhibited Social Engagement Disorder (DSED). Results DSE trajectories initially increased and then stabilized. PIs had higher DSE levels initially and a steeper increase rate than NAs. When separated into physical and non-physical DSE components, group differences arose in initial physical DSE and the rate of change of non-physical DSE. DSE rate of increase predicted DSED diagnosis, as did longer institutional duration and poorer institutional care. Conclusions The rate of increase in DSE post-adoption, rather than the level observed at adoption, is predictive of disordered social engagement by age 5 years. PMID:27460336

Rapid, convenient method for screening imidazole-containing compounds for heme oxygenase inhibition.

PubMed

Vlahakis, Jason Z; Rahman, Mona N; Roman, Gheorghe; Jia, Zongchao; Nakatsu, Kanji; Szarek, Walter A

2011-01-01

Sensitive assays for measuring heme oxygenase activity have been based on the gas-chromatographic detection of carbon monoxide using elaborate, expensive equipment. The present study describes a rapid and convenient method for screening imidazole-containing candidates for inhibitory activity against heme oxygenase using a plate reader, based on the spectroscopic evaluation of heme degradation. A PowerWave XS plate reader was used to monitor the absorbance (as a function of time) of heme bound to purified truncated human heme oxygenase-1 (hHO-1) in the individual wells of a standard 96-well plate (with or without the addition of a test compound). The degradation of heme by heme oxygenase-1 was initiated using l-ascorbic acid, and the collected relevant absorbance data were analyzed by three different methods to calculate the percent control activity occurring in wells containing test compounds relative to that occurring in control wells with no test compound present. In the cases of wells containing inhibitory compounds, significant shifts in λ(max) from 404 to near 412 nm were observed as well as a decrease in the rate of heme degradation relative to that of the control. Each of the three methods of data processing (overall percent drop in absorbance over 1.5h, initial rate of reaction determined over the first 5 min, and estimated pseudo first-order reaction rate constant determined over 1.5h) gave similar and reproducible results for percent control activity. The fastest and easiest method of data analysis was determined to be that using initial rates, involving data acquisition for only 5 min once reactions have been initiated using l-ascorbic acid. The results of the study demonstrate that this simple assay based on the spectroscopic detection of heme represents a rapid, convenient method to determine the relative inhibitory activity of candidate compounds, and is useful in quickly screening a series or library of compounds for heme oxygenase inhibition. Copyright © 2010 Elsevier Inc. All rights reserved.

Recruitment of private practices for primary care research: experience in a preventive services clinical trial.

PubMed

McBride, P E; Massoth, K M; Underbakke, G; Solberg, L I; Beasley, J W; Plane, M B

1996-10-01

Recruitment of community primary care practices for studies to improve health service delivery is important to many health care organizations. Prior studies have focused on individual physician recruitment or academic settings. This descriptive study evaluated the efficiency and utility of three different recruitment methods to encourage community practice participation in a preventive services research trial. Primary care practices in four midwestern states were recruited using different sources for initial mailings (physician lists, practice lists, and a managed care organization's primary care network) and different recruiting methods. Outcome measures included response rates, participation rates, and comparative costs of each method. Of the 86 eligible practices contacted, 52 (60%) consented to participate. Mailing to individual physicians was the most cumbersome and expensive method and had the lowest response rate. Initial contacts with practice medical directors increased the participation rate substantially, and practice recruitment meetings improved both study participation and practice-project communication. Experience with these three methods suggests that the most efficient way to recruit practices for participation in a preventive services research trial involves targeted mailings and phone calls to medical directors, followed by on-site practice meetings.

Perceptions of Supervision Processes and Practices in Initial Contract, Tenured, and Distinguished-Rated Teachers as They Relate to Self-Learning and Growth in One Large Suburban School District

ERIC Educational Resources Information Center

Watters, Chad M.

2017-01-01

The purpose of this mixed methods study is to examine the perceptions of supervision practices in initial contract, tenured, and distinguished-rated teachers at the elementary level in one large, suburban school district. This study described teacher perceptions of clinical and alternative supervision practices. Six research questions guided this…

Contraceptive discontinuation and pregnancy postabortion in Nepal: a longitudinal cohort study.

PubMed

Puri, Mahesh; Henderson, Jillian T; Harper, Cynthia C; Blum, Maya; Joshi, Deepak; Rocca, Corinne H

2015-04-01

To examine postabortion contraceptive discontinuation and pregnancy in Nepal, where abortion was decriminalized in 2002. We conducted an observational cohort study of 654 women obtaining abortions from four public and nongovernmental facilities in 2011. Patients completed questionnaires at their abortion visit and 6 and 12 months later. We used Cox proportional hazards models to assess contraceptive discontinuation and pregnancy by method initiated postabortion and other sociodemographic and reproductive factors. Among the 78% (508/654) of women who initiated a modern contraceptive method within 3 months postabortion, the 1-year contraceptive discontinuation rate was 62 per 100 person-years. Discontinuation was far lower among the 5% of women using long-acting reversible methods (21/100 person-years) than among those using condoms (74/100 person-years), pills (61/100 person-years) and the injectable [64/100 person-years; adjusted hazard ratio (aHR)=0.32 (0.15-0.68)]. Unmarried women and those not living with their husband experienced higher contraceptive discontinuation [aHR=2.16 (1.47-3.17)]. The 1-year pregnancy rate for all women was 9/100 person-years. Pregnancy was highest among those who initiated no modern method postabortion (13/100 person-years) and condoms (12/100 person-years), and pregnancy was lowest among users of long-acting reversible methods (3/100 person-years). The poorest women were at increased pregnancy risk [aHR=2.31 (1.32-4.10)]. Women using intrauterine devices and implants experienced greatly reduced contraceptive discontinuation and pregnancy within a year postabortion, although initiation of these long-acting methods was low. Increased availability of long-acting methods in Nepal and similar settings may help to prevent unwanted pregnancy and attendant maternal mortality and morbidities. Initiation of modern contraception was high postabortion; however, 1-year discontinuation was high for the condom, pill and injectable, the methods most commonly used. Rates for intrauterine devices and implants were low. Results support efforts to facilitate patient knowledge and access to the full range of contraceptives, including long-acting reversible methods. Copyright © 2015 Elsevier Inc. All rights reserved.

Dynamic Fracture Properties of Rocks Subjected to Static Pre-load Using Notched Semi-circular Bend Method

NASA Astrophysics Data System (ADS)

Chen, Rong; Li, Kang; Xia, Kaiwen; Lin, Yuliang; Yao, Wei; Lu, Fangyun

2016-10-01

A dynamic load superposed on a static pre-load is a key problem in deep underground rock engineering projects. Based on a modified split Hopkinson pressure bar test system, the notched semi-circular bend (NSCB) method is selected to investigate the fracture initiation toughness of rocks subjected to pre-load. In this study, a two-dimensional ANSYS finite element simulation model is developed to calculate the dimensionless stress intensity factor. Three groups of NSCB specimen are tested under a pre-load of 0, 37 and 74 % of the maximum static load and with the loading rate ranging from 0 to 60 GPa m1/2 s-1. The results show that under a given pre-load, the fracture initiation toughness of rock increases with the loading rate, resembling the typical rate dependence of materials. Furthermore, the dynamic rock fracture toughness decreases with the static pre-load at a given loading rate. The total fracture toughness, defined as the sum of the dynamic fracture toughness and initial stress intensity factor calculated from the pre-load, increases with the pre-load at a given loading rate. An empirical equation is used to represent the effect of loading rate and pre-load force, and the results show that this equation can depict the trend of the experimental data.

18 CFR 342.3 - Indexing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Indexing. 342.3 Section....3 Indexing. (a) Rate changes. A rate charged by a carrier may be changed, at any time, to a level... December 31, 1994. (5) When an initial rate, or rate changed by a method other than indexing, takes effect...

18 CFR 342.3 - Indexing.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Indexing. 342.3 Section....3 Indexing. (a) Rate changes. A rate charged by a carrier may be changed, at any time, to a level... December 31, 1994. (5) When an initial rate, or rate changed by a method other than indexing, takes effect...

18 CFR 342.3 - Indexing.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Indexing. 342.3 Section....3 Indexing. (a) Rate changes. A rate charged by a carrier may be changed, at any time, to a level... December 31, 1994. (5) When an initial rate, or rate changed by a method other than indexing, takes effect...

18 CFR 342.3 - Indexing.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Indexing. 342.3 Section....3 Indexing. (a) Rate changes. A rate charged by a carrier may be changed, at any time, to a level... December 31, 1994. (5) When an initial rate, or rate changed by a method other than indexing, takes effect...

Novel kinetic spectrophotometric method for estimation of certain biologically active phenolic sympathomimetic drugs in their bulk powders and different pharmaceutical formulations

NASA Astrophysics Data System (ADS)

Omar, Mahmoud A.; Badr El-Din, Khalid M.; Salem, Hesham; Abdelmageed, Osama H.

2018-03-01

A simple, selective and sensitive kinetic spectrophotometric method was described for estimation of four phenolic sympathomimetic drugs namely; terbutaline sulfate, fenoterol hydrobromide, isoxsuprine hydrochloride and etilefrine hydrochloride. This method is depended on the oxidation of the phenolic drugs with Folin-Ciocalteu reagent in presence of sodium carbonate. The rate of color development at 747-760 nm was measured spectrophotometrically. The experimental parameters controlling the color development were fully studied and optimized. The reaction mechanism for color development was proposed. The calibration graphs for both the initial rate and fixed time methods were constructed, where linear correlations were found in the general concentration ranges of 3.65 × 10- 6-2.19 × 10- 5 mol L- 1 and 2-24.0 μg mL- 1 with correlation coefficients in the following range 0.9992-0.9999, 0.9991-0.9998 respectively. The limits of detection and quantitation for the initial rate and fixed time methods were found to be in general concentration range 0.109-0.273, 0.363-0.910 and 0.210-0.483, 0.700-1.611 μg mL- 1 respectively. The developed method was validated according to ICH and USP 30 -NF 25 guidelines. The suggested method was successfully implemented to the estimation of these drugs in their commercial pharmaceutical formulations and the recovery percentages obtained were ranged from 97.63% ± 1.37 to 100.17% ± 0.95 and 97.29% ± 0.74 to 100.14 ± 0.81 for initial rate and fixed time methods respectively. The data obtained from the analysis of dosage forms were compared with those obtained by reported methods. Statistical analysis of these results indicated no significant variation in the accuracy and precision of both the proposed and reported methods.

Study of Survival Rate After Cardiopulmonary Resuscitation (CPR) in Hospitals of Kermanshah in 2013

PubMed Central

Goodarzi, Afshin; Jalali, Amir; Almasi, Afshin; Naderipour, Arsalan; Kalhori, Reza Pourmirza; Khodadadi, Amineh

2015-01-01

Background: After CPR, the follow-up of survival rate and caused complications are the most important practices of the medical group. This study was performed aimed at determining the follow-up results after CPR in patients of university hospitals in Kermanshah in 2014. Methods: In this prospective study, 320 samples were examined. A purposive sampling method was used, and data was collected using a researcher-made information form with content and face validity and reliability of r= 0.79. Data was analyzed with STATA9 software and statistical tests, including calculation of the success rate, relative risk (RR), chi-square and Fisher at significance level of P < 0.05. Results: The initial success rate of cardiopulmonary resuscitation was equal to 15.3%, while the ultimate success rate (discharged alive from the hospital) was as 10.6%. The six-month success rate after resuscitation was 8.78% than those who were discharged alive. There were no significant statistical differences between different age groups regarding the initial success rate of resuscitation (P = 0.14), and the initial resuscitation success rate was higher in patients in morning shift (P = 0.02). Conclusion: By the results of study, it is recommended to increase the medical - nursing knowledge and techniques for personnel in the evening and night shifts. Also, an appropriate dissemination of health care staff in working shifts should be done to increase the success rate of CPR procedure. PMID:25560341

Size-guided multi-seed heuristic method for geometry optimization of clusters: Application to benzene clusters.

PubMed

Takeuchi, Hiroshi

2018-05-08

Since searching for the global minimum on the potential energy surface of a cluster is very difficult, many geometry optimization methods have been proposed, in which initial geometries are randomly generated and subsequently improved with different algorithms. In this study, a size-guided multi-seed heuristic method is developed and applied to benzene clusters. It produces initial configurations of the cluster with n molecules from the lowest-energy configurations of the cluster with n - 1 molecules (seeds). The initial geometries are further optimized with the geometrical perturbations previously used for molecular clusters. These steps are repeated until the size n satisfies a predefined one. The method locates putative global minima of benzene clusters with up to 65 molecules. The performance of the method is discussed using the computational cost, rates to locate the global minima, and energies of initial geometries. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Regional Variation in Breast Cancer Rates in the United States (Past Initiative)

Cancer.gov

Five institutions are being funded to conduct research using epidemiologic and statistical methods for determining whether various factors may account for the geographic differences in breast cancer rates in the United States.

A dual method for optimal control problems with initial and final boundary constraints.

NASA Technical Reports Server (NTRS)

Pironneau, O.; Polak, E.

1973-01-01

This paper presents two new algorithms belonging to the family of dual methods of centers. The first can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states. The second one can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states and with affine instantaneous inequality constraints on the control. Convergence is established for both algorithms. Qualitative reasoning indicates that the rate of convergence is linear.

Breast feeding initiation rate across Western countries: does religion matter? An ecological study

PubMed Central

Cohen, Emmanuel; Kramer, Michael S

2016-01-01

Background Breast feeding initiation rates remain below 80% in some Western countries. Many individual-level determinants are known; however, less is known regarding cultural and societal determinants, such as religion, that could explain population-level variations. We examined the correlations of the proportions of Catholics and Protestants with the breast feeding initiation rates across and within Western countries. Methods Using publicly available data, we carried out an ecological study comparing the proportions of Catholics and Protestants with the rates of breast feeding initiation. We correlated data at the country level, and additionally explored within-country data in five Western countries: France (Departments), Ireland (counties), the UK (countries), Canada (provinces) and the USA (states). Our analyses accounted for human development index, gross domestic product and population density. Results We observed a negative correlation (r=−0.30) between the proportion of Catholics and the rate of breast feeding initiation in Western countries. This correlation was consistent when using within-country data in France (r=−0.27), Ireland (r=−0.23), the UK (r=−0.79) and Canada (r=−0.62). In the USA, the positive correlation (r=0.26) between a state's proportion of Catholics and its breast feeding initiation rate was confounded by race, education and socioeconomic status (SES). After controlling for education and SES, the state proportion of non-Hispanic white Catholics was negatively correlated (r=−0.29) with the rate of breast feeding initiation. Conclusions In this ecological study, we found consistent negative correlations between Catholicism and breast feeding initiation rates. Qualitative and quantitative studies at the individual level are needed to confirm and explain our findings. Our results suggest that women living in a country or region where Catholicism has historically dominated are less likely to initiate breast feeding, and that breast feeding promotion policies should be adapted to better fit populations' cultural and religious norms. PMID:28588983

Fast two-position initial alignment for SINS using velocity plus angular rate measurements

NASA Astrophysics Data System (ADS)

Chang, Guobin

2015-10-01

An improved two-position initial alignment model for strapdown inertial navigation system is proposed. In addition to the velocity, angular rates are incorporated as measurements. The measurement equations in full three channels are derived in both navigation and body frames and the latter of which is found to be preferred. The cross-correlation between the process and the measurement noises is analyzed and addressed in the Kalman filter. The incorporation of the angular rates, without introducing additional device or external signal, speeds up the convergence of estimating the attitudes, especially the heading. In the simulation study, different algorithms are tested with different initial errors, and the advantages of the proposed method compared to the conventional one are validated by the simulation results.

Regulation of proteasomal degradation by modulating proteasomal initiation regions

PubMed Central

Takahashi, Kazunobu; Matouschek, Andreas; Inobe, Tomonao

2016-01-01

Methods for regulating the concentrations of specific cellular proteins are valuable tools for biomedical studies. Artificial regulation of protein degradation by the proteasome is receiving increasing attention. Efficient proteasomal protein degradation requires a degron with two components: a ubiquitin tag that is recognized by the proteasome and a disordered region at which the proteasome engages the substrate and initiates degradation. Here we show that degradation rates can be regulated by modulating the disordered initiation region by the binding of modifier molecules, in vitro and in vivo. These results suggest that artificial modulation of proteasome initiation is a versatile method for conditionally inhibiting the proteasomal degradation of specific proteins. PMID:26278914

Accuracy of neutron self-activation method with iodine-containing scintillators for quantifying 128I generation using decay-fitting technique

NASA Astrophysics Data System (ADS)

Nohtomi, Akihiro; Wakabayashi, Genichiro

2015-11-01

We evaluated the accuracy of a self-activation method with iodine-containing scintillators in quantifying 128I generation in an activation detector; the self-activation method was recently proposed for photo-neutron on-line measurements around X-ray radiotherapy machines. Here, we consider the accuracy of determining the initial count rate R0, observed just after termination of neutron irradiation of the activation detector. The value R0 is directly related to the amount of activity generated by incident neutrons; the detection efficiency of radiation emitted from the activity should be taken into account for such an evaluation. Decay curves of 128I activity were numerically simulated by a computer program for various conditions including different initial count rates (R0) and background rates (RB), as well as counting statistical fluctuations. The data points sampled at minute intervals and integrated over the same period were fit by a non-linear least-squares fitting routine to obtain the value R0 as a fitting parameter with an associated uncertainty. The corresponding background rate RB was simultaneously calculated in the same fitting routine. Identical data sets were also evaluated by a well-known integration algorithm used for conventional activation methods and the results were compared with those of the proposed fitting method. When we fixed RB = 500 cpm, the relative uncertainty σR0 /R0 ≤ 0.02 was achieved for R0/RB ≥ 20 with 20 data points from 1 min to 20 min following the termination of neutron irradiation used in the fitting; σR0 /R0 ≤ 0.01 was achieved for R0/RB ≥ 50 with the same data points. Reasonable relative uncertainties to evaluate initial count rates were reached by the decay-fitting method using practically realistic sampling numbers. These results clarified the theoretical limits of the fitting method. The integration method was found to be potentially vulnerable to short-term variations in background levels, especially instantaneous contaminations by spike-like noise. The fitting method easily detects and removes such spike-like noise.

Is there an ideal stimulation regimen for IVF for poor responders and does it change with age?

PubMed Central

Osianlis, Tiki; Catt, James

2008-01-01

Purpose To determine whether there is a superior treatment modality for ‘poor’ responders. Method Retrospective analysis of three stimulation regimens, with patients stratified based on age, stimulation regime and response in previous cycles (“poor’ responder or “non poor” responder). Fertilisation, embryo utilisation and clinical pregnancy rates were assessed. There were a total of 1,608 cycles in the ‘poor’ responder and 8,489 cycles in the ‘non poor’ responder groups. Results In ‘poor’ responders there was no significant difference in fertilisation rate, nor utilisation rate between the three stimulation regimes and no differences in the pregnancy rate/initiated cycle irrespective of age and stimulation regimen in any of the groups. ‘Non poor’ responders had a significantly greater pregnancy rate/initiated cycle for all stimulation regimens in both age groups compared with ‘poor’ responders. Conclusion This large retrospective study of ‘poor’ responders has not shown a difference in pregnancy rates/initiated cycle between stimulation regimens. PMID:18982442

Quantitative assessments of arousal by analyzing microsaccade rates and pupil fluctuations prior to slow eye movements.

PubMed

Honda, Shogo; Kohama, Takeshi; Tanaka, Tatsuro; Yoshida, Hisashi

2014-01-01

It is well known that a decline of arousal level causes of poor performance of movements or judgments. Our previous study indicates that microsaccade (MS) rates and pupil fluctuations change before slow eye movements (SEMs) (Honda et al. 2013). However, SEM detection of this study was obscure and insufficient. In this study, we propose a new SEM detection method and analyze MS rates and pupil fluctuations while subjects maintain their gaze on a target. We modified Shin et al.'s method, which is optimized for EOG (electrooculography) signals, to extract the period of sustaining SEMs using a general eye tracker. After SEM detection, we analyzed MS rates and pupil fluctuations prior to the initiation of SEMs. As a result, we were able to detect SEMs more precisely than in our previous study. Moreover, the results of eye movements and pupil fluctuations analyses show that gradual rise of MS rate and longitudinal miosis are observed prior to the initiation of SEMs, which is consistent with our previous study. These findings suggest that monitoring eye movements and pupil fluctuations may evaluate the arousal level more precisely. Further, we found that these tendencies become more significant when they are restricted to the initial SEMs.

Strain-Rate Dependence of Deformation-Twinning in Tantalum

NASA Astrophysics Data System (ADS)

Abeywardhana, Jayalath; Germann, Tim; Ravelo, Ramon

2017-06-01

Large-Scale molecular dynamics (MD) simulations are used to model quasi-isentropic compression and expansion (QIC) in tantalum crystals varying the rate of deformation between the range 108 -1012s-1 and compressive pressures up to 100 GPa. The atomic interactions were modeled employing an embedded-atom method (EAM) potential of Ta. Isentropic expansion was done employing samples initially compressed to pressures of 60 and 100 GPa followed by uniaxial and quasi-isentropically expansion to zero pressure. The effect of initial dislocation density on twinning was also examined by varying the initial defect density of the Ta samples (1010 -1012cm-2). At these high-strain rates, a threshold in strain-rate on deformation twining is observed. Under expansion or compression, deformation twinning increases with strain rate for strain-rates >109s-1 . Below this value, small fraction of twins nucleates but anneal out with time. Samples with lower fraction of twins equilibrate to defect states containing higher screw dislocation densities from those with initially higher twinning fractions. This work was supported by the Department of Energy under contract DE-AC52-06NA25396 and by the Air Force Office of Scientific Research under AFOSR Award No. FA9550-12-1-0476.

A hybrid method for synthetic aperture ladar phase-error compensation

NASA Astrophysics Data System (ADS)

Hua, Zhili; Li, Hongping; Gu, Yongjian

2009-07-01

As a high resolution imaging sensor, synthetic aperture ladar data contain phase-error whose source include uncompensated platform motion and atmospheric turbulence distortion errors. Two previously devised methods, rank one phase-error estimation algorithm and iterative blind deconvolution are reexamined, of which a hybrid method that can recover both the images and PSF's without any a priori information on the PSF is built to speed up the convergence rate by the consideration in the choice of initialization. To be integrated into spotlight mode SAL imaging model respectively, three methods all can effectively reduce the phase-error distortion. For each approach, signal to noise ratio, root mean square error and CPU time are computed, from which we can see the convergence rate of the hybrid method can be improved because a more efficient initialization set of blind deconvolution. Moreover, by making a further discussion of the hybrid method, the weight distribution of ROPE and IBD is found to be an important factor that affects the final result of the whole compensation process.

Investigating the spring bloom initiation and net community production in the Subantarctic Southern Ocean using high-resolution in situ glider data

NASA Astrophysics Data System (ADS)

thomalla, sandy; Racault, Marie-Fanny; Swart, Sebastiaan; Monteiro, Pedro

2014-05-01

Phytoplankton bloom phenology has important consequences for marine ecosystems, fisheries and carbon export to the ocean interior. As such, it is important to examine the drivers of phytoplankton bloom initiation and their sensitivity to inter-annual climate variability and change. In this study we use ~6 months of in-situ high-resolution glider data to investigate the spring bloom initiation in the subantarctic zone (SAZ) of the Southern Ocean by implementing three different methods; a rate of change method, a threshold method and a cumulative sum method. The bloom initiation dates are critically compared to one another and the drivers of discrepancies assessed to inform on the sensitivities of different methods to processes driving the seasonal evolution of phytoplankton biomass in the subantarctic. The bloom initiation dates combined with in situ glider data of chlorophyll, light, and mixed layer depth allow us to resolve both Sverdrup's Critical Depth and Behrenfeld's Disturbance Recovery models through the water column and thus determine the seasonal evolution of net community production and respiration rates and the potential for carbon export. The outputs of the two different models are compared to one another in the context of their sensitivities to water column processes thereby refining their ability to address specific system scale questions. The novelty of this study is that gliders provide an unprecedented dataset to assess the seasonal cycle of phytoplankton biomass throughout the water column at high resolution, thus enhancing our understanding of net community production and export processes at submeso-space and sub-seasonal time scales.

Attitude algorithm and initial alignment method for SINS applied in short-range aircraft

NASA Astrophysics Data System (ADS)

Zhang, Rong-Hui; He, Zhao-Cheng; You, Feng; Chen, Bo

2017-07-01

This paper presents an attitude solution algorithm based on the Micro-Electro-Mechanical System and quaternion method. We completed the numerical calculation and engineering practice by adopting fourth-order Runge-Kutta algorithm in the digital signal processor. The state space mathematical model of initial alignment in static base was established, and the initial alignment method based on Kalman filter was proposed. Based on the hardware in the loop simulation platform, the short-range flight simulation test and the actual flight test were carried out. The results show that the error of pitch, yaw and roll angle is fast convergent, and the fitting rate between flight simulation and flight test is more than 85%.

Variables Affecting Pharmacy Students’ Patient Care Interventions during Advanced Pharmacy Practice Experiences

PubMed Central

Patterson, Brandon J.; Sen, Sanchita; Bingham, Angela L.; Bowen, Jane F.; Ereshefsky, Benjamin; Siemianowski, Laura A.

2016-01-01

Objective. To identify the temporal effect and factors associated with student pharmacist self-initiation of interventions during acute patient care advanced pharmacy practice experiences (APPE). Methods. During the APPE, student pharmacists at an academic medical center recorded their therapeutic interventions and who initiated the intervention throughout clinical rotations. At the end of the APPE student pharmacists completed a demographic survey. Results. Sixty-two student pharmacists were included. Factors associated with lower rates of self-initiated interventions were infectious diseases and pediatrics APPEs and an intention to pursue a postgraduate residency. Timing of the APPE, previous specialty elective course completion, and previous hospital experience did not result in any significant difference in self-initiated recommendations. Conclusion. Preceptors should not base practice experience expectations for self-initiated interventions on previous student experience or future intentions. Additionally, factors leading to lower rates of self-initiated interventions on infectious diseases or pediatrics APPEs should be explored. PMID:27756924

The successive projection algorithm as an initialization method for brain tumor segmentation using non-negative matrix factorization.

PubMed

Sauwen, Nicolas; Acou, Marjan; Bharath, Halandur N; Sima, Diana M; Veraart, Jelle; Maes, Frederik; Himmelreich, Uwe; Achten, Eric; Van Huffel, Sabine

2017-01-01

Non-negative matrix factorization (NMF) has become a widely used tool for additive parts-based analysis in a wide range of applications. As NMF is a non-convex problem, the quality of the solution will depend on the initialization of the factor matrices. In this study, the successive projection algorithm (SPA) is proposed as an initialization method for NMF. SPA builds on convex geometry and allocates endmembers based on successive orthogonal subspace projections of the input data. SPA is a fast and reproducible method, and it aligns well with the assumptions made in near-separable NMF analyses. SPA was applied to multi-parametric magnetic resonance imaging (MRI) datasets for brain tumor segmentation using different NMF algorithms. Comparison with common initialization methods shows that SPA achieves similar segmentation quality and it is competitive in terms of convergence rate. Whereas SPA was previously applied as a direct endmember extraction tool, we have shown improved segmentation results when using SPA as an initialization method, as it allows further enhancement of the sources during the NMF iterative procedure.

A comparative study of different methods for calculating electronic transition rates

NASA Astrophysics Data System (ADS)

Kananenka, Alexei A.; Sun, Xiang; Schubert, Alexander; Dunietz, Barry D.; Geva, Eitan

2018-03-01

We present a comprehensive comparison of the following mixed quantum-classical methods for calculating electronic transition rates: (1) nonequilibrium Fermi's golden rule, (2) mixed quantum-classical Liouville method, (3) mean-field (Ehrenfest) mixed quantum-classical method, and (4) fewest switches surface-hopping method (in diabatic and adiabatic representations). The comparison is performed on the Garg-Onuchic-Ambegaokar benchmark charge-transfer model, over a broad range of temperatures and electronic coupling strengths, with different nonequilibrium initial states, in the normal and inverted regimes. Under weak to moderate electronic coupling, the nonequilibrium Fermi's golden rule rates are found to be in good agreement with the rates obtained via the mixed quantum-classical Liouville method that coincides with the fully quantum-mechanically exact results for the model system under study. Our results suggest that the nonequilibrium Fermi's golden rule can serve as an inexpensive yet accurate alternative to Ehrenfest and the fewest switches surface-hopping methods.

Simplified Two-Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydorgen/Oxygen

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2005-01-01

A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two-time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (> 1 x 10(exp -20) moles/cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T4). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/air fuel and for the H2/O2. A similar correlation is also developed using data from NASA s Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T4) as a function of overall fuel/air ratio, pressure and initial temperature (T3). High values of the regression coefficient R2 are obtained.

Summary of Simplified Two Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydrogen/Oxygen

NASA Technical Reports Server (NTRS)

Marek, C. John; Molnar, Melissa

2005-01-01

A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (greater than l x 10(exp -20)) moles per cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T(sub 4)). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/Air fuel and for H2/O2. A similar correlation is also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T(sub 4)) as a function of overall fuel/air ratio, pressure and initial temperature (T(sub 3)). High values of the regression coefficient R squared are obtained.

New Reduced Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2004-01-01

A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes that are being developed at Glenn. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx were obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3). The temperature of the gas entering the turbine (T4) was also correlated as a function of the initial combustor temperature (T3), equivalence ratio, water to fuel mass ratio, and pressure.

Trauma airway management in emergency departments: a multicentre, prospective, observational study in Japan.

PubMed

Nakao, Shunichiro; Kimura, Akio; Hagiwara, Yusuke; Hasegawa, Kohei

2015-02-04

Although successful airway management is essential for emergency trauma care, comprehensive studies are limited. We sought to characterise current trauma care practice of airway management in the emergency departments (EDs) in Japan. Analysis of data from a prospective, observational, multicentre registry-the Japanese Emergency Airway Network (JEAN) registry. 13 academic and community EDs from different geographic regions across Japan. 723 trauma patients who underwent emergency intubation from March 2010 through August 2012. ED characteristics, patient and operator demographics, methods of airway management, intubation success or failure at each attempt and adverse events. A total of 723 trauma patients who underwent emergency intubation were eligible for the analysis. Traumatic cardiac arrest comprised 32.6% (95% CI 29.3% to 36.1%) of patients. Rapid sequence intubation (RSI) was the initial method chosen in 23.9% (95% CI 21.0% to 27.2%) of all trauma patients and in 35.5% (95% CI 31.4% to 39.9%) of patients without cardiac arrest. Overall, intubation was successful in ≤3 attempts in 96% of patients (95% CI 94.3% to 97.2%). There was a wide variation in the initial methods of intubation; RSI as the initial method was performed in 0-50.9% of all trauma patients among 12 EDs. Similarly, there was a wide variation in success rates and adverse event rates across the EDs. Success rates varied between 35.5% and 90.5% at the first attempt, and 85.1% and 100% within three attempts across the 12 EDs. In this multicentre prospective study in Japan, we observed a high overall success rate in airway management during trauma care. However, the methods of intubation and success rates were highly variable among hospitals. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

New approach for determination of sulfadiazine in pharmaceutical preparations using 4(4-sulphophenylazo)pyrogallol: Kinetic spectrophotometric method.

PubMed

Naser, Naser A; Alasedi, Kasim M; Khan, Zainab A

2018-05-04

A new trend describes the development and validation of a simple, sensitive and selective kinetic spectrophotometric methods for the determination of sulfadiazine in pharmaceutical formulations has been conducted. In this paper, sulfadiazine was derivatized as a new organic compound 4(4-sulphophenylazo) pyrogallol, 4-SPAP, by coupling pyrogallol with diazotized sulfadiazine in medium of controlled pH. 4-SPAP was characterized by techniques of FT-IR, H-NMR, GC-Mass, TG and DSC thermal analysis methods. Solvatochromic behavior in solvents of various polarities was also investigated. The determination of sulfadiazine was accomplished by initial rate and fixed time methods. These methods were based on the reaction of the compound containing sulfadiazine, 4-SPAP, with Ca(II) to form colored product with a maximum absorbance at 520 nm. The two methods were adopted for constructing the calibration curves and examined for their suitability for the quantitation of sulfadiazine in pharmaceuticals. The limit of detection (LOD) and limit of quantification (LOQ) were found to be, by initial rate method, 0.35 and 1.05 μg·mL -1 and that by fixed time method were found to be 0.69 and 2.07 μg·mL -1 , respectively. The percent relative standard deviations (%RSD) for the results ranged from 1.04% to 1.76% and 0.85% to 1.42% for the initial rate and fixed time methods of the proposed kinetic spectrophotometric method, respectively. The existence of common excipients in the pharmaceutical formulation did not produce any significant interference. Statistical comparison was reported as indicated from the F- and t-test data of the proposed methods with that of reference method showing excellent agreement and indicating no significant difference in their accuracy and precision. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of empirical Bayes methods to predict the rate of decline in ERG at the individual level among patients with retinitis pigmentosa.

PubMed

Qiu, Weiliang; Sandberg, Michael A; Rosner, Bernard

2018-05-31

Retinitis pigmentosa is one of the most common forms of inherited retinal degeneration. The electroretinogram (ERG) can be used to determine the severity of retinitis pigmentosa-the lower the ERG amplitude, the more severe the disease is. In practice for career, lifestyle, and treatment counseling, it is of interest to predict the ERG amplitude of a patient at a future time. One approach is prediction based on the average rate of decline for individual patients. However, there is considerable variation both in initial amplitude and in rate of decline. In this article, we propose an empirical Bayes (EB) approach to incorporate the variations in initial amplitude and rate of decline for the prediction of ERG amplitude at the individual level. We applied the EB method to a collection of ERGs from 898 patients with 3 or more visits over 5 or more years of follow-up tested in the Berman-Gund Laboratory and observed that the predicted values at the last (kth) visit obtained by using the proposed method based on data for the first k-1 visits are highly correlated with the observed values at the kth visit (Spearman correlation =0.93) and have a higher correlation with the observed values than those obtained based on either the population average decline rate or those obtained based on the individual decline rate. The mean square errors for predicted values obtained by the EB method are also smaller than those predicted by the other methods. Copyright © 2018 John Wiley & Sons, Ltd.

40 CFR 63.7822 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... determine the volumetric flow rate of the stack gas. (iii) Method 3, 3A, or 3B to determine the dry... of particulate matter, grains per dry standard cubic foot (gr/dscf); Q = Volumetric flow rate of... flow-weighted concentration for each test run using Equation 2 of this section as follows: ER20MY03.001...

40 CFR 63.7822 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... determine the volumetric flow rate of the stack gas. (iii) Method 3, 3A, or 3B to determine the dry... of particulate matter, grains per dry standard cubic foot (gr/dscf); Q = Volumetric flow rate of... flow-weighted concentration for each test run using Equation 2 of this section as follows: ER20MY03.001...

40 CFR 63.7822 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... determine the volumetric flow rate of the stack gas. (iii) Method 3, 3A, or 3B to determine the dry... of particulate matter, grains per dry standard cubic foot (gr/dscf); Q = Volumetric flow rate of... flow-weighted concentration for each test run using Equation 2 of this section as follows: ER20MY03.001...

Peptide kinetics from picoseconds to microseconds using boxed molecular dynamics: Power law rate coefficients in cyclisation reactions

NASA Astrophysics Data System (ADS)

Shalashilin, Dmitrii V.; Beddard, Godfrey S.; Paci, Emanuele; Glowacki, David R.

2012-10-01

Molecular dynamics (MD) methods are increasingly widespread, but simulation of rare events in complex molecular systems remains a challenge. We recently introduced the boxed molecular dynamics (BXD) method, which accelerates rare events, and simultaneously provides both kinetic and thermodynamic information. We illustrate how the BXD method may be used to obtain high-resolution kinetic data from explicit MD simulations, spanning picoseconds to microseconds. The method is applied to investigate the loop formation dynamics and kinetics of cyclisation for a range of polypeptides, and recovers a power law dependence of the instantaneous rate coefficient over six orders of magnitude in time, in good agreement with experimental observations. Analysis of our BXD results shows that this power law behaviour arises when there is a broad and nearly uniform spectrum of reaction rate coefficients. For the systems investigated in this work, where the free energy surfaces have relatively small barriers, the kinetics is very sensitive to the initial conditions: strongly non-equilibrium conditions give rise to power law kinetics, while equilibrium initial conditions result in a rate coefficient with only a weak dependence on time. These results suggest that BXD may offer us a powerful and general algorithm for describing kinetics and thermodynamics in chemical and biochemical systems.

Single-Specimen Technique to Establish the J-Resistance of Linear Viscoelastic Solids with Constant Poisson's Ratio

NASA Technical Reports Server (NTRS)

Gutierrez-Lemini, Danton; McCool, Alex (Technical Monitor)

2001-01-01

A method is developed to establish the J-resistance function for an isotropic linear viscoelastic solid of constant Poisson's ratio using the single-specimen technique with constant-rate test data. The method is based on the fact that, for a test specimen of fixed crack size under constant rate, the initiation J-integral may be established from the crack size itself, the actual external load and load-point displacement at growth initiation, and the relaxation modulus of the viscoelastic solid, without knowledge of the complete test record. Since crack size alone, of the required data, would be unknown at each point of the load-vs-load-point displacement curve of a single-specimen test, an expression is derived to estimate it. With it, the physical J-integral at each point of the test record may be established. Because of its basis on single-specimen testing, not only does the method not require the use of multiple specimens with differing initial crack sizes, but avoids the need for tracking crack growth as well.

A rate-based transcutaneous CO2 sensor for noninvasive respiration monitoring.

PubMed

Chatterjee, M; Ge, X; Kostov, Y; Luu, P; Tolosa, L; Woo, H; Viscardi, R; Falk, S; Potts, R; Rao, G

2015-05-01

The pain and risk of infection associated with invasive blood sampling for blood gas measurements necessitate the search for reliable noninvasive techniques. In this work we developed a novel rate-based noninvasive method for a safe and fast assessment of respiratory status. A small sampler was built to collect the gases diffusing out of the skin. It was connected to a CO2 sensor through gas-impermeable tubing. During a measurement, the CO2 initially present in the sampler was first removed by purging it with nitrogen. The gases in the system were then recirculated between the sampler and the CO2 sensor, and the CO2 diffusion rate into the sampler was measured. Because the measurement is based on the initial transcutaneous diffusion rate, reaching mass transfer equilibrium and heating the skin is no longer required, thus, making it much faster and safer than traditional method. A series of designed experiments were performed to analyze the effect of the measurement parameters such as sampler size, measurement location, subject positions, and movement. After the factor analysis tests, the prototype was sent to a level IV NICU for clinical trial. The results show that the measured initial rate of increase in CO2 partial pressure is linearly correlated with the corresponding arterial blood gas measurements. The new approach can be used as a trending tool, making frequent blood sampling unnecessary for respiratory status monitoring.

Unicameral bone cysts: a comparison of injection of steroid and grafting with autologous bone marrow.

PubMed

Cho, H S; Oh, J H; Kim, H-S; Kang, H G; Lee, S H

2007-02-01

Open surgery is rarely justified for the initial treatment of a unicameral bone cyst, but there is some debate concerning the relative effectiveness of closed methods. This study compared the results of steroid injection with those of autologous bone marrow grafting for the treatment of unicameral bone cysts. Between 1990 and 2001, 30 patients were treated by steroid injection and 28 by grafting with autologous bone marrow. The overall success rates were 86.7% and 92.0%, respectively (p>0.05). The success rate after the initial procedure was 23.3% in the steroid group and 52.0% in those receiving autologous bone marrow (p<0.05), and the respective cumulative success rates after second injections were 63.3% and 80.0% (p>0.05). The mean number of procedures required was 2.19 (1 to 5) and 1.57 (1 to 3) (p<0.05), the mean interval to healing was 12.5 months (4 to 32) and 14.3 months (7 to 36) (p>0.05), and the rate of recurrence after the initial procedure was 41.7% and 13.3% in the steroid and in the autologous bone marrow groups, respectively (p<0.05). Although the overall rates of success of both methods were similar, the steroid group had higher recurrence after a single procedure and required more injections to achieve healing.

Determination of acidity and nucleophilicity in thiols by reaction with monobromobimane and fluorescence detection.

PubMed

Sardi, Florencia; Manta, Bruno; Portillo-Ledesma, Stephanie; Knoops, Bernard; Comini, Marcelo A; Ferrer-Sueta, Gerardo

2013-04-01

A method based on the differential reactivity of thiol and thiolate with monobromobimane (mBBr) has been developed to measure nucleophilicity and acidity of protein and low-molecular-weight thiols. Nucleophilicity of the thiolate is measured as the pH-independent second-order rate constant of its reaction with mBBr. The ionization constants of the thiols are obtained through the pH dependence of either second-order rate constant or initial rate of reaction. For readily available thiols, the apparent second-order rate constant is measured at different pHs and then plotted and fitted to an appropriate pH function describing the observed number of ionization equilibria. For less available thiols, such as protein thiols, the initial rate of reaction is determined in a wide range of pHs and fitted to the appropriate pH function. The method presented here shows excellent sensitivity, allowing the use of nanomolar concentrations of reagents. The method is suitable for scaling and high-throughput screening. Example determinations of nucleophilicity and pK(a) are presented for captopril and cysteine as low-molecular-weight thiols and for human peroxiredoxin 5 and Trypanosoma brucei monothiol glutaredoxin 1 as protein thiols. Copyright © 2013 Elsevier Inc. All rights reserved.

Post-marketing surveillance of Norplant((R)) contraceptive implants: II. Non-reproductive health(1).

PubMed

2001-04-01

This controlled cohort study aimed to evaluate the safety and efficacy of Norplant contraceptive implants in developing countries. Women initiating Norplant implants were index subjects and women initiating intrauterine devices (IUDs) or surgical sterilization were controls. Consenting participants at 32 clinics in eight developing countries were admitted and followed-up every 6 months for 5 years. Major and less serious health events during follow-up were recorded. Incidence rate ratios of health events adjusted for clinic were estimated for initial and current method use. This paper reports non-reproductive health events. The study involved 7,977 women initiating use of Norplant, 6,625 of IUD, and 1,419 of sterilization. Five years follow-up was completed for 94.6% of the women. The study accumulated 78,323 woman-years of observation. The initial method chosen accounted for 84.4% or more of observed woman-years in users of Norplant, IUD, or sterilization. Twenty-two of the recorded 34 deaths were due to accidents, suicide or homicide. Few deaths or major health events were due to cancer or acute cardiovascular diseases and were not associated with the contraceptive method used. The incidence rates of major health events were low and with two exceptions, there was no significant excess risk of serious morbidity for Norplant users compared with controls; among Norplant initiators gallbladder disease occurred at an incidence rate of 1.5 per 1,000 woman-years and was weakly associated with use of Norplant (rate ratio 1.52 [95% C.I. 1.02, 2.27]). For current Norplant users compared to controls, the rate ratio of a combined variable of hypertension and borderline hypertension was significantly elevated (1.81, [1.12, 2.92]). The occurrence of less serious health events was also low and several of them were significantly more often reported among Norplant users. Headache-migraine, weight gain, mood disturbances, pruritus, eczema, and acne had incidence rates among Norplant users of 11.5, 4.5, 2.8, 1.5, 1.4, and 0.9 per 1,000 woman-years, respectively, and were significantly higher than in controls. Respiratory health problems, nonspecific symptoms, and several ill-defined conditions were also significantly more often reported for Norplant users, but some of the excess incidence may be attributable to reporting and detection bias. The study confirms the safety with respect to serious disease of Norplant, IUDs, and sterilization.

Studies on DNA damage: discordant responses of rate of DNA disentanglement (viscosimetrically evaluated) and alkaline elution rate, obtained for several compounds. Possible explanations of the discrepancies.

PubMed

Parodi, S; Balbi, C; Abelmoschi, M L; Pala, M; Russo, P; Santi, L

1983-12-01

Alkaline elution is a well-known method for detecting DNA damage. Recently we have developed a viscosimetric method that is even more sensitive than alkaline elution. Here we report that the two methods, although apparently both revealing alkaline DNA fragmentation, can give dramatically different results for a significant series of compounds. We suspect that alkaline elution might reveal not only DNA fragmentation but also the extent of disentanglement of chromatin structure, whereas this DNA disentanglement rate, when evaluated viscosimetrically , is more strictly correlated with the initiation of DNA unwinding.

An inviscid-viscous interaction approach to the calculation of dynamic stall initiation on airfoils

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

Cebeci, T.; Platzer, M.F.; Jang, H.M.

An interactive boundary-layer method is described for computing unsteady incompressible flow over airfoils, including the initiation of dynamic stall. The inviscid unsteady panel method developed by Platzer and Teng is extended to include viscous effects. The solutions of the boundary-layer equations are obtained with an inverse finite-difference method employing an interaction law based on the Hilbert integral, and the algebraic eddy-viscosity formulation of Cebeci and Smith. The method is applied to airfoils subject to periodic and ramp-type motions and its abilities are examined for a range of angles of attack, reduced frequency, and pitch rate.

Advanced bridge safety initiative, task 3 : slab bridge load rating using AASHTO methodology and finite element analysis - an analysis of 20 bridges.

DOT National Transportation Integrated Search

2011-12-01

Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

Advanced bridge safety initiative, task 1 : development of improved analytical load rating procedures for flat-slab concrete bridges - a thesis and guidelines.

DOT National Transportation Integrated Search

2010-01-01

Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

Experience of treatment of patients with granulomatous lobular mastitis

PubMed Central

Hur, Sung Mo; Cho, Dong Hui; Lee, Se Kyung; Choi, Min-Young; Bae, Soo Youn; Koo, Min Young; Kim, Sangmin; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo; Nam, Seok-Jin; Yang, Jung-Hyun

2013-01-01

Purpose To present the author's experience with various treatment methods of granulomatous lobular mastitis (GLM) and to determine effective treatment methods of GLM. Methods Fifty patients who were diagnosed with GLM were classified into five groups based on the initial treatment methods they underwent, which included observation (n = 8), antibiotics (n = 3), steroid (n = 13), drainage (n = 14), and surgical excision (n = 12). The treatment processes in each group were examined and their clinical characteristics, treatment processes, and results were analyzed respectively. Results Success rates with each initial treatment were observation, 87.5%; antibiotics, 33.3%; steroids, 30.8%; drainage, 28.6%; and surgical excision, 91.7%. In most cases of observation, the lesions were small and the symptoms were mild. A total of 23 patients underwent surgical excision during treatment. Surgical excision showed particularly fast recovery, high success rate (90.3%) and low recurrence rate (8.7%). Conclusion The clinical course of GLM is complex and the outcome of each treatment type are variable. Surgery may play an important role when a lesion is determined to be mass-forming or appears localized as an abscess pocket during breast examination or imaging study. PMID:23833753

Cardiac biplane strain imaging: initial in vivo experience

NASA Astrophysics Data System (ADS)

Lopata, R. G. P.; Nillesen, M. M.; Verrijp, C. N.; Singh, S. K.; Lammens, M. M. Y.; van der Laak, J. A. W. M.; van Wetten, H. B.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

2010-02-01

In this study, first we propose a biplane strain imaging method using a commercial ultrasound system, yielding estimation of the strain in three orthogonal directions. Secondly, an animal model of a child's heart was introduced that is suitable to simulate congenital heart disease and was used to test the method in vivo. The proposed approach can serve as a framework to monitor the development of cardiac hypertrophy and fibrosis. A 2D strain estimation technique using radio frequency (RF) ultrasound data was applied. Biplane image acquisition was performed at a relatively low frame rate (<100 Hz) using a commercial platform with an RF interface. For testing the method in vivo, biplane image sequences of the heart were recorded during the cardiac cycle in four dogs with an aortic stenosis. Initial results reveal the feasibility of measuring large radial, circumferential and longitudinal cumulative strain (up to 70%) at a frame rate of 100 Hz. Mean radial strain curves of a manually segmented region-of-interest in the infero-lateral wall show excellent correlation between the measured strain curves acquired in two perpendicular planes. Furthermore, the results show the feasibility and reproducibility of assessing radial, circumferential and longitudinal strains simultaneously. In this preliminary study, three beagles developed an elevated pressure gradient over the aortic valve (Δp: 100-200 mmHg) and myocardial hypertrophy. One dog did not develop any sign of hypertrophy (Δp = 20 mmHg). Initial strain (rate) results showed that the maximum strain (rate) decreased with increasing valvular stenosis (-50%), which is in accordance with previous studies. Histological findings corroborated these results and showed an increase in fibrotic tissue for the hearts with larger pressure gradients (100, 200 mmHg), as well as lower strain and strain rate values.

Drug resistance characteristics of Mycobacterium tuberculosis isolates to four first-line antituberculous drugs from tuberculosis patients with AIDS in Beijing, China.

PubMed

Gao, Gui-ju; Lian, Lulu; Sun, Yue; Wei, Jianhao; Xiao, Jiang; Wang, Xiaoying; Zhang, Ling; Zhao, Xiuqin; Yang, Di; Zhao, Hong-xin; Zhao, Hui; Wang, Hui-zhu; Wan, Kang-lin; Li, Xing-wang

2015-02-01

The objective of this study was to investigate the drug resistance characteristics of Mycobacterium tuberculosis isolates to four first-line antituberculous drugs (ATDs) from tuberculosis (TB) patients with AIDS in Beijing, China. All M. tuberculosis strains were isolated from specimens from TB patients with AIDS hospitalised between April 2010 and October 2012. Isolates were cultured by mycobacterial culture methods and were identified by multilocus PCR. Drug sensitivity testing was performed by the proportion method with the following first-line ATDs: isoniazid; rifampicin; streptomycin; and ethambutol. Results were compared with the drug resistance status of M. tuberculosis strains isolated from TB patients without HIV infection in Beijing. Among 41 M. tuberculosis isolates from TB patients with AIDS, the rates of total drug resistance (58.5%), initial drug resistance (46.7%) and acquired drug resistance (90.9%) were significantly higher than in TB patients without HIV infection (34.1%, 24.5% and 48.5%, respectively; P<0.05). In TB patients with AIDS, the rates of acquired drug resistance (90.9%) and acquired multidrug-resistant TB (MDR-TB) (54.5%) were significantly higher than the rates of initial drug resistance (46.7%) and initial MDR-TB (10.0%) (P<0.05). In patients with TB without HIV infection, the rate of acquired drug resistance (48.5%) was significantly higher than the rate of initial drug resistance (24.5%) (P<0.05). M. tuberculosis drug resistance in TB patients with AIDS is significantly more serious than in TB patients without HIV infection. These results showed that more attention should be paid to M. tuberculosis drug resistance in AIDS patients. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

THE EFFECT OF STEP RATE MANIPULATION ON FOOT STRIKE PATTERN OF LONG DISTANCE RUNNERS.

PubMed

Allen, Darrell J; Heisler, Hollie; Mooney, Jennifer; Kring, Richard

2016-02-01

Running gait retraining to change foot strike pattern in runners from a heel strike pattern to a non heel- strike pattern has been shown to reduce impact forces and may help to reduce running related injuries. Step rate manipulation above preferred is known to help decrease step length, foot inclination angle, and vertical mass excursion, but has not yet been evaluated as a method to change foot strike pattern. The purpose of this study was to investigate the effect of step rate manipulation on foot strike pattern in shod recreational runners who run with a heel strike pattern. A secondary purpose was to describe the effect of step rate manipulation at specific percentages above preferred on foot inclination angle at initial contact. Forty volunteer runners, who were self-reported heel strikers and had a weekly running mileage of at least 10 miles, were recruited. Runners were confirmed to be heel strikers during the warm up period on the treadmill. The subject's step rate was determined at their preferred running pace. A metronome was used to increase step rate above the preferred step rate by 5%, 10% and 15%. 2D video motion analysis was utilized to determine foot strike pattern and to measure foot inclination angle at initial contact for each step rate condition. There was a statistically significant change in foot strike pattern from a heel strike pattern to a mid-foot or forefoot strike pattern at both 10% and 15% step rates above preferred. Seven of the 40 subjects (17.5%) changed from a heel- strike pattern to a non- heel strike pattern at +10% and 12 of the 40 subjects (30%) changed to a non-heel strike pattern at +15%. Mean foot inclination angle at initial contact showed a statistically significant change (reduction) as step rate increased. Step rate manipulation of 10% or greater may be enough to change foot strike pattern from a heel strike to a mid-foot or forefoot strike pattern in a small percentage of recreational runners who run in traditional running shoes. If changing the foot strike pattern is the main goal, other gait re-training methods may be needed to make a change from a heel strike to a non-heel strike pattern. Step rate manipulation shows a progressive reduction of foot inclination angle at 5%, 10%, and 15% above preferred step rate which reduces the severity of the heel strike at initial contact. Step rate manipulation of at least +10% above preferred may be an effective running gait retraining method for clinicians to decrease the severity of heel strike and possibly assist a runner to change to a non-heel strike pattern. 3.

Experience of treatment of patients with granulomatous lobular mastitis.

PubMed

Hur, Sung Mo; Cho, Dong Hui; Lee, Se Kyung; Choi, Min-Young; Bae, Soo Youn; Koo, Min Young; Kim, Sangmin; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo; Nam, Seok-Jin; Yang, Jung-Hyun; Lee, Jeong Eon

2013-07-01

To present the author's experience with various treatment methods of granulomatous lobular mastitis (GLM) and to determine effective treatment methods of GLM. Fifty patients who were diagnosed with GLM were classified into five groups based on the initial treatment methods they underwent, which included observation (n = 8), antibiotics (n = 3), steroid (n = 13), drainage (n = 14), and surgical excision (n = 12). The treatment processes in each group were examined and their clinical characteristics, treatment processes, and results were analyzed respectively. Success rates with each initial treatment were observation, 87.5%; antibiotics, 33.3%; steroids, 30.8%; drainage, 28.6%; and surgical excision, 91.7%. In most cases of observation, the lesions were small and the symptoms were mild. A total of 23 patients underwent surgical excision during treatment. Surgical excision showed particularly fast recovery, high success rate (90.3%) and low recurrence rate (8.7%). The clinical course of GLM is complex and the outcome of each treatment type are variable. Surgery may play an important role when a lesion is determined to be mass-forming or appears localized as an abscess pocket during breast examination or imaging study.

Online automatic tuning and control for fed-batch cultivation

PubMed Central

van Straten, Gerrit; van der Pol, Leo A.; van Boxtel, Anton J. B.

2007-01-01

Performance of controllers applied in biotechnological production is often below expectation. Online automatic tuning has the capability to improve control performance by adjusting control parameters. This work presents automatic tuning approaches for model reference specific growth rate control during fed-batch cultivation. The approaches are direct methods that use the error between observed specific growth rate and its set point; systematic perturbations of the cultivation are not necessary. Two automatic tuning methods proved to be efficient, in which the adaptation rate is based on a combination of the error, squared error and integral error. These methods are relatively simple and robust against disturbances, parameter uncertainties, and initialization errors. Application of the specific growth rate controller yields a stable system. The controller and automatic tuning methods are qualified by simulations and laboratory experiments with Bordetella pertussis. PMID:18157554

Estimating error rates for firearm evidence identifications in forensic science

PubMed Central

Song, John; Vorburger, Theodore V.; Chu, Wei; Yen, James; Soons, Johannes A.; Ott, Daniel B.; Zhang, Nien Fan

2018-01-01

Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed congruent matching cells (CMC) method for image comparisons, its application to firearm evidence identification, and its usage and initial tests for error rate estimation. The CMC method divides compared topography images into correlation cells. Four identification parameters are defined for quantifying both the topography similarity of the correlated cell pairs and the pattern congruency of the registered cell locations. A declared match requires a significant number of CMCs, i.e., cell pairs that meet all similarity and congruency requirements. Initial testing on breech face impressions of a set of 40 cartridge cases fired with consecutively manufactured pistol slides showed wide separation between the distributions of CMC numbers observed for known matching and known non-matching image pairs. Another test on 95 cartridge cases from a different set of slides manufactured by the same process also yielded widely separated distributions. The test results were used to develop two statistical models for the probability mass function of CMC correlation scores. The models were applied to develop a framework for estimating cumulative false positive and false negative error rates and individual error rates of declared matches and non-matches for this population of breech face impressions. The prospect for applying the models to large populations and realistic case work is also discussed. The CMC method can provide a statistical foundation for estimating error rates in firearm evidence identifications, thus emulating methods used for forensic identification of DNA evidence. PMID:29331680

Pharmacy claims data versus patient self-report to measure contraceptive method continuation.

PubMed

Triebwasser, Jourdan E; Higgins, Stephanie; Secura, Gina M; Zhao, Qiuhong; Peipert, Jeffrey F

2015-07-01

To compare self-reported 12-month continuation of oral contraceptive pills (OCPs), patch, and ring versus continuation by pharmacy claims data. Women in the Contraceptive CHOICE Project who chose OCPs, the patch, or the ring as their initial method were included. Continuation was assessed by periodic telephone survey and by obtaining prescription claims data. Continuation was defined as no gap of more than 30 days. Kaplan-Meier survival functions were used to estimate continuation rates and cumulative unintended pregnancy rates. Kappa statistic assessed the level of agreement between self-report and claims data. We analyzed 1510 women who initiated use by 3 months and provided information on discontinuation. Of OCP users, 59% continued their method at 12 months by self-report versus 38% by pharmacy claims. Patch and ring users had self-reported/pharmacy continuation of 45%/28% and 57%/37%, respectively. Kappa coefficients and their 95% confidence intervals between the two measurements were 0.46 (0.40, 0.52), 0.54 (0.39, 0.68), and 0.54 (0.47, 0.61) for OCP, patch, and ring, respectively. Among women who self-reported continuation, unintended pregnancy rates were 0.4% in those who continued by pharmacy claims versus 4.9% in those who discontinued according to claims data. Contraceptive continuation rates differ by self-report versus pharmacy claims with women overestimating their continuation by self-report. This article directly compares contraception continuation rates by self-report and by pharmacy claims data. The study suggests that previously reported continuation rates from survey data overestimate specific method use. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimating error rates for firearm evidence identifications in forensic science.

PubMed

Song, John; Vorburger, Theodore V; Chu, Wei; Yen, James; Soons, Johannes A; Ott, Daniel B; Zhang, Nien Fan

2018-03-01

Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed congruent matching cells (CMC) method for image comparisons, its application to firearm evidence identification, and its usage and initial tests for error rate estimation. The CMC method divides compared topography images into correlation cells. Four identification parameters are defined for quantifying both the topography similarity of the correlated cell pairs and the pattern congruency of the registered cell locations. A declared match requires a significant number of CMCs, i.e., cell pairs that meet all similarity and congruency requirements. Initial testing on breech face impressions of a set of 40 cartridge cases fired with consecutively manufactured pistol slides showed wide separation between the distributions of CMC numbers observed for known matching and known non-matching image pairs. Another test on 95 cartridge cases from a different set of slides manufactured by the same process also yielded widely separated distributions. The test results were used to develop two statistical models for the probability mass function of CMC correlation scores. The models were applied to develop a framework for estimating cumulative false positive and false negative error rates and individual error rates of declared matches and non-matches for this population of breech face impressions. The prospect for applying the models to large populations and realistic case work is also discussed. The CMC method can provide a statistical foundation for estimating error rates in firearm evidence identifications, thus emulating methods used for forensic identification of DNA evidence. Published by Elsevier B.V.

Surrounding community residents’ expectations of HOPE VI for their community, health and physical activity

PubMed Central

Dulin-Keita, Akilah; Hannon, Lonnie; Buys, David; Casazza, Krista; Clay, Olivio

2016-01-01

Using a community-engaged participatory research approach, this study identified surrounding community residents’ expectations for how a HOPE VI housing initiative might affect their community and individual health and physical activity. Fifty-nine women and men engaged in concept mapping, which is a mixed methods approach, where participants generate, sort, and rate ideas. Participants generated 197 unique statements. Thirteen thematic clusters related to expected changes for the community, health and physical activity emerged. Residents’ rated ‘Increased Pride in the Neighborhood’ and ‘Increased Safety’ as the most important factors related to HOPE VI whereas ‘Drawbacks of HOPE VI’ was rated as least important. This research provides insight into the potential impacts of housing initiatives from the perspective of those most affected by such initiatives. The findings also highlight environmental changes as potential mechanisms that may improve residents’ perceptions of the community and encourage healthy lifestyles. PMID:27667912

Simulating initial attack with two fire containment models

Treesearch

Romain M. Mees

1985-01-01

Given a variable rate of fireline construction and an elliptical fire growth model, two methods for estimating the required number of resources, time to containment, and the resulting fire area were compared. Five examples illustrate some of the computational differences between the simple and the complex methods. The equations for the two methods can be used and...

Method of Real-Time Principal-Component Analysis

NASA Technical Reports Server (NTRS)

Duong, Tuan; Duong, Vu

2005-01-01

Dominant-element-based gradient descent and dynamic initial learning rate (DOGEDYN) is a method of sequential principal-component analysis (PCA) that is well suited for such applications as data compression and extraction of features from sets of data. In comparison with a prior method of gradient-descent-based sequential PCA, this method offers a greater rate of learning convergence. Like the prior method, DOGEDYN can be implemented in software. However, the main advantage of DOGEDYN over the prior method lies in the facts that it requires less computation and can be implemented in simpler hardware. It should be possible to implement DOGEDYN in compact, low-power, very-large-scale integrated (VLSI) circuitry that could process data in real time.

Deducing the Kinetics of Protein Synthesis In Vivo from the Transition Rates Measured In Vitro

PubMed Central

Rudorf, Sophia; Thommen, Michael; Rodnina, Marina V.; Lipowsky, Reinhard

2014-01-01

The molecular machinery of life relies on complex multistep processes that involve numerous individual transitions, such as molecular association and dissociation steps, chemical reactions, and mechanical movements. The corresponding transition rates can be typically measured in vitro but not in vivo. Here, we develop a general method to deduce the in-vivo rates from their in-vitro values. The method has two basic components. First, we introduce the kinetic distance, a new concept by which we can quantitatively compare the kinetics of a multistep process in different environments. The kinetic distance depends logarithmically on the transition rates and can be interpreted in terms of the underlying free energy barriers. Second, we minimize the kinetic distance between the in-vitro and the in-vivo process, imposing the constraint that the deduced rates reproduce a known global property such as the overall in-vivo speed. In order to demonstrate the predictive power of our method, we apply it to protein synthesis by ribosomes, a key process of gene expression. We describe the latter process by a codon-specific Markov model with three reaction pathways, corresponding to the initial binding of cognate, near-cognate, and non-cognate tRNA, for which we determine all individual transition rates in vitro. We then predict the in-vivo rates by the constrained minimization procedure and validate these rates by three independent sets of in-vivo data, obtained for codon-dependent translation speeds, codon-specific translation dynamics, and missense error frequencies. In all cases, we find good agreement between theory and experiment without adjusting any fit parameter. The deduced in-vivo rates lead to smaller error frequencies than the known in-vitro rates, primarily by an improved initial selection of tRNA. The method introduced here is relatively simple from a computational point of view and can be applied to any biomolecular process, for which we have detailed information about the in-vitro kinetics. PMID:25358034

Longitudinal Investigation of Smoking Initiation and Relapse Among Younger and Older US Military Personnel

PubMed Central

Trone, Daniel W.; Peterson, Arthur V.; Jacobson, Isabel G.; Littman, Alyson J.; Maynard, Charles; Seelig, Amber D.; Crum-Cianflone, Nancy F.; Bricker, Jonathan B.

2015-01-01

Objectives. We examined whether military service, including deployment and combat experience, were related to smoking initiation and relapse. Methods. We included older (panel 1) and younger (panel 2) participants in the Millennium Cohort Study. Never smokers were followed for 3 to 6 years for smoking initiation, and former smokers were followed for relapse. Complementary log-log regression models estimated the relative risk (RR) of initiation and relapse by military exposure while adjusting for demographic, health, and lifestyle factors. Results. Deployment with combat experience predicted higher initiation rate (panel 1: RR = 1.44; 95% confidence interval [CI] = 1.28, 1.62; panel 2: RR = 1.26; 95% CI = 1.04, 1.54) and relapse rate (panel 1 only: RR = 1.48; 95% CI = 1.36, 1.62). Depending on the panel, previous mental health disorders, life stressors, and other military and nonmilitary characteristics independently predicted initiation and relapse. Conclusions. Deployment with combat experience and previous mental disorder may identify military service members in need of intervention to prevent smoking initiation and relapse. PMID:25880953

A Review: Pharmaceutical and Pharmacokinetic Aspect of Nanocrystalline Suspensions.

PubMed

Shah, Dhaval A; Murdande, Sharad B; Dave, Rutesh H

2016-01-01

Nanocrystals have emerged as a potential formulation strategy to eliminate the bioavailability-related problems by enhancing the initial dissolution rate and moderately super-saturating the thermodynamic solubility. This review contains an in-depth knowledge of, the processing method for formulation, an accurate quantitative assessment of the solubility and dissolution rates and their correlation to observe pharmacokinetic data. Poor aqueous solubility is considered the major hurdle in the development of pharmaceutical compounds. Because of a lack of understanding with regard to the change in the thermodynamic and kinetic properties (i.e., solubility and dissolution rate) upon nanosizing, we critically reviewed the literatures for solubility determination to understand the significance and accuracy of the implemented analytical method. In the latter part, we reviewed reports that have quantitatively studied the effect of the particle size and the surface area change on the initial dissolution rate enhancement using alternative approaches besides the sink condition dissolution. The lack of an apparent relationship between the dissolution rate enhancement and the observed bioavailability are discussed by reviewing the reported in vivo data on animal models along with the particle size and food effect. The review will provide comprehensive information to the pharmaceutical scientist in the area of nanoparticulate drug delivery.

Process relevant screening of cellulolytic organisms for consolidated bioprocessing.

PubMed

Antonov, Elena; Schlembach, Ivan; Regestein, Lars; Rosenbaum, Miriam A; Büchs, Jochen

2017-01-01

Although the biocatalytic conversion of cellulosic biomass could replace fossil oil for the production of various compounds, it is often not economically viable due to the high costs of cellulolytic enzymes. One possibility to reduce costs is consolidated bioprocessing (CBP), integrating cellulase production, hydrolysis of cellulose, and the fermentation of the released sugars to the desired product into one process step. To establish such a process, the most suitable cellulase-producing organism has to be identified. Thereby, it is crucial to evaluate the candidates under target process conditions. In this work, the chosen model process was the conversion of cellulose to the platform chemical itaconic acid by a mixed culture of a cellulolytic fungus with Aspergillus terreus as itaconic acid producer. Various cellulase producers were analyzed by the introduced freeze assay that measures the initial carbon release rate, quantifying initial cellulase activity under target process conditions. Promising candidates were then characterized online by monitoring their respiration activity metabolizing cellulose to assess the growth and enzyme production dynamics. The screening of five different cellulase producers with the freeze assay identified Trichoderma   reesei and Penicillium   verruculosum as most promising. The measurement of the respiration activity revealed a retarded induction of cellulase production for P.   verruculosum but a similar cellulase production rate afterwards, compared to T.   reesei . The freeze assay measurement depicted that P.   verruculosum reaches the highest initial carbon release rate among all investigated cellulase producers. After a modification of the cultivation procedure, these results were confirmed by the respiration activity measurement. To compare both methods, a correlation between the measured respiration activity and the initial carbon release rate of the freeze assay was introduced. The analysis revealed that the different initial enzyme/cellulose ratios as well as a discrepancy in cellulose digestibility are the main differences between the two approaches. With two complementary methods to quantify cellulase activity and the dynamics of cellulase production for CBP applications, T.   reesei and P.   verruculosum were identified as compatible candidates for the chosen model process. The presented methods can easily be adapted to screen for suitable cellulose degrading organisms for various other applications.

Direct Numerical Simulation of a Temporally Evolving Incompressible Plane Wake: Effect of Initial Conditions on Evolution and Topology

NASA Technical Reports Server (NTRS)

Sondergaard, R.; Cantwell, B.; Mansour, N.

1997-01-01

Direct numerical simulations have been used to examine the effect of the initial disturbance field on the development of three-dimensionality and the transition to turbulence in the incompressible plane wake. The simulations were performed using a new numerical method for solving the time-dependent, three-dimensional, incompressible Navier-Stokes equations in flows with one infinite and two periodic directions. The method uses standard Fast Fourier Transforms and is applicable to cases where the vorticity field is compact in the infinite direction. Initial disturbances fields examined were combinations of two-dimensional waves and symmetric pairs of 60 deg oblique waves at the fundamental, subharmonic, and sub-subharmonic wavelengths. The results of these simulations indicate that the presence of 60 deg disturbances at the subharmonic streamwise wavelength results in the development of strong coherent three-dimensional structures. The resulting strong three-dimensional rate-of-strain triggers the growth of intense fine scale motions. Wakes initiated with 60 deg disturbances at the fundamental streamwise wavelength develop weak coherent streamwise structures, and do not develop significant fine scale motions, even at high Reynolds numbers. The wakes which develop strong three-dimensional structures exhibit growth rates on par with experimentally observed turbulent plane wakes. Wakes which develop only weak three-dimensional structures exhibit significantly lower late time growth rates. Preliminary studies of wakes initiated with an oblique fundamental and a two-dimensional subharmonic, which develop asymmetric coherent oblique structures at the subharmonic wavelength, indicate that significant fine scale motions only develop if the resulting oblique structures are above an angle of approximately 45 deg.

Advanced bridge safety initiative : recommended practices for live load testing of existing flat-slab concrete bridges - task 5.

DOT National Transportation Integrated Search

2012-12-01

Current AASHTO provisions for load rating flat-slab concrete bridges use the equivalent strip : width method, which is regarded as overly conservative compared to more advanced analysis : methods and field live load testing. It has been shown that li...

Design and performance of limestone drains to increase pH and remove metals from acidic mine drainage, Chapter 2

USGS Publications Warehouse

Cravotta,, Charles A.; Watzlaf, George R.

2002-01-01

Data on the construction characteristics and the composition of influent and effluent at 13 underground, limestone-filled drains in Pennsylvania and Maryland are reported to evaluate the design and performance of limestone drains for the attenuation of acidity and dissolved metals in acidic mine drainage. On the basis of the initial mass of limestone, dimensions of the drains, and average flow rates, the initial porosity and average detention time for each drain were computed. Calculated porosity ranged from 0.12 to 0.50 with corresponding detention times at average flow from 1.3 to 33 h. The effectiveness of treatment was dependent on influent chemistry, detention time, and limestone purity. At two sites where influent contained elevated dissolved Al (>5 mg/liter), drain performance declined rapidly; elsewhere the drains consistently produced near-neutral effluent, even when influent contained small concentrations of dissolved Fe^+ (<5 mg/liter). Rates of limestone dissolution computed on the basis of average long-term Ca ion flux normalized by initial mass and purity of limestone at each of the drains ranged from 0.008 to 0.079 year-1. Data for alkalinity concentration and flux during 11-day closed-container tests using an initial mass of 4kg crushed limestone and a solution volume of 2.3 liter yielded dissolution rate constants that were comparable to these long-term field rates. An analytical method is proposed using closed-container test data to evaluate long-term performance (longevity) or to estimate the mass of limestone needed for a limestone treatment. This method condisers flow rate, influent alkalinity, steady-state alkalinity of effluent, and desired effluent alkalinity or detention time at a future time(s) and aplies first-order rate laws for limestone dissolution (continuous) and production of alkalinity (bounded).

Effect of surface crystallographic orientation on the oxidation behavior of Ni-based alloy

NASA Astrophysics Data System (ADS)

Wang, Xu; Szpunar, J. A.; Zhang, Lina

2015-02-01

Dependence of initial oxidation behavior on crystalline orientation of Haynes 230 at 900 °C was investigated by a novel method. Analysis of oxidation rate reveals that the oxide thicknesses are different for grains having different orientations. Orientation mapping was performed on oxidized specimen and grains having near {1 1 1} were easily indexed by electron backscattered diffraction. We determined that planes with deviation angle lower than 20° were all well indexed after oxidation. Results demonstrate that substrate orientation plays an important role on oxidation rate during the initial stage.

On determining dose rate constants spectroscopically.

PubMed

Rodriguez, M; Rogers, D W O

2013-01-01

To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of (125)I and (103)Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089-6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated (125)I and (103)Pd sources. Spectra generated by 14 (125)I and 6 (103)Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 × 2.7 × 0.05 cm(3) voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the (125)I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for (103)Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were ≤0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. The ratio of the intensity of the 31 keV line relative to that of the main peak in (125)I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The (103)Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different investigations are in much better agreement with the calculations using the NCRP Report 58 and NNDC(2000) initial spectra with average discrepancies of 0.9% and 1.7% for the (125)I and (103)Pd seeds, respectively. However, there are no differences in the calculated TG-43U1 brachytherapy parameters using either initial spectrum in both cases. Similarly, there were no differences outside the statistical uncertainties of 0.1% or 0.2%, in the average energy, air kerma/history, dose rate/history, and dose rate constant when calculated using either the full photon spectrum or the main-peaks-only spectrum. Our calculated dose rate constants based on using the calculated on-axis spectrum and a line or dual-point source model are in excellent agreement (0.5% on average) with the values of Chen and Nath, verifying the accuracy of their more approximate method of going from the spectrum to the dose rate constant. However, the dose rate constants based on full seed models differ by between +4.6% and -1.5% from those based on the line or dual-point source approximations. These results suggest that the main value of spectroscopic measurements is to verify full Monte Carlo models of the seeds by comparison to the calculated spectra.

Funding policies and postabortion long-acting reversible contraception: results from a cluster randomized trial.

PubMed

Rocca, Corinne H; Thompson, Kirsten M J; Goodman, Suzan; Westhoff, Carolyn L; Harper, Cynthia C

2016-06-01

Almost one-half of women having an abortion in the United States have had a previous procedure, which highlights a failure to provide adequate preventive care. Provision of intrauterine devices and implants, which have high upfront costs, can be uniquely challenging in the abortion care setting. We conducted a study of a clinic-wide training intervention on long-acting reversible contraception and examined the effect of the intervention, insurance coverage, and funding policies on the use of long-acting contraceptives after an abortion. This subanalysis of a cluster, randomized trial examines data from the 648 patients who had undergone an abortion who were recruited from 17 reproductive health centers across the United States. The trial followed participants 18-25 years old who did not desire pregnancy for a year. We measured the effect of the intervention, health insurance, and funding policies on contraceptive outcomes, which included intrauterine device and implant counseling and selection at the abortion visit, with the use of logistic regression with generalized estimating equations for clustering. We used survival analysis to model the actual initiation of these methods over 1 year. Women who obtained abortion care at intervention sites were more likely to report intrauterine device and implant counseling (70% vs 41%; adjusted odds ratio, 3.83; 95% confidence interval, 2.37-6.19) and the selection of these methods (36% vs 21%; adjusted odds ratio, 2.11; 95% confidence interval, 1.39-3.21). However, the actual initiation of methods was similar between study arms (22/100 woman-years each; adjusted hazard ratio, 0.88; 95% confidence interval, 0.51-1.51). Health insurance and funding policies were important for the initiation of intrauterine devices and implants. Compared with uninsured women, those women with public health insurance had a far higher initiation rate (adjusted hazard ratio, 2.18; 95% confidence interval, 1.31-3.62). Women at sites that provide state Medicaid enrollees abortion coverage also had a higher initiation rate (adjusted hazard ratio, 1.73; 95% confidence interval, 1.04-2.88), as did those at sites with state mandates for private health insurance to cover contraception (adjusted hazard ratio, 1.80; 95% confidence interval, 1.06-3.07). Few of the women with private insurance used it to pay for the abortion (28%), but those who did initiated long-acting contraceptive methods at almost twice the rate as women who paid for it themselves or with donated funds (adjusted hazard ratio, 1.94; 95% confidence interval, 1.10-3.43). The clinic-wide training increased long-acting reversible contraceptive counseling and selection but did not change initiation for abortion patients. Long-acting method use after abortion was associated strongly with funding. Restrictions on the coverage of abortion and contraceptives in abortion settings prevent the initiation of desired long-acting methods. Copyright © 2015 Elsevier Inc. All rights reserved.

Long-Acting Reversible Contraception Counseling and Use for Older Adolescents and Nulliparous Women.

PubMed

Gibbs, Susannah E; Rocca, Corinne H; Bednarek, Paula; Thompson, Kirsten M J; Darney, Philip D; Harper, Cynthia C

2016-12-01

The majority of pregnancies during adolescence are unintended, and few adolescents use long-acting reversible contraception (LARC) due in part to health care providers' misconceptions about nulliparous women's eligibility for the intrauterine device. We examined differences in LARC counseling, selection, and initiation by age and parity in a study with a provider's LARC training intervention. Sexually active women aged 18-25 years receiving contraceptive counseling (n = 1,500) were enrolled at 20 interventions and 20 control clinics and followed for 12 months. We assessed LARC counseling and selection, by age and parity, with generalized estimated equations with robust standard errors. We assessed LARC use over 1 year with Cox proportional hazards models with shared frailty for clustering. Women in the intervention had increased LARC counseling, selection, and initiation, with similar effects among older adolescent and nulliparous women, and among young adult and parous women. Across study arms, older adolescents were as likely as young adults to receive LARC counseling (adjusted odds ratio [aOR] = .85; 95% confidence interval [CI]: .63-1.15), select LARC (aOR = .86; 95% CI: .64-1.17), and use LARC methods (adjusted hazard ratio [aHR] = .94; 95% CI: .69-1.27). Nulliparous women were less likely to receive counseling (aOR = .57; 95% CI: .42-.79) and to select LARC (aOR = .53; 95% CI: .37-.75) than parous women, and they initiated LARC methods at lower rates (aHR = .65; 95% CI: .48-.90). Nulliparous women had similar rates of implant initiation but lower rates of intrauterine device initiation (aHR = .59; 95% CI: .41-.85). Continued efforts should be made to improve counseling and access to LARC methods for nulliparous women of all ages. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Recruitment Methods and Show Rates to a Prostate Cancer Early Detection Program for High-Risk Men: A Comprehensive Analysis

PubMed Central

Giri, Veda N.; Coups, Elliot J.; Ruth, Karen; Goplerud, Julia; Raysor, Susan; Kim, Taylor Y.; Bagden, Loretta; Mastalski, Kathleen; Zakrzewski, Debra; Leimkuhler, Suzanne; Watkins-Bruner, Deborah

2009-01-01

Purpose Men with a family history (FH) of prostate cancer (PCA) and African American (AA) men are at higher risk for PCA. Recruitment and retention of these high-risk men into early detection programs has been challenging. We report a comprehensive analysis on recruitment methods, show rates, and participant factors from the Prostate Cancer Risk Assessment Program (PRAP), which is a prospective, longitudinal PCA screening study. Materials and Methods Men 35–69 years are eligible if they have a FH of PCA, are AA, or have a BRCA1/2 mutation. Recruitment methods were analyzed with respect to participant demographics and show to the first PRAP appointment using standard statistical methods Results Out of 707 men recruited, 64.9% showed to the initial PRAP appointment. More individuals were recruited via radio than from referral or other methods (χ2 = 298.13, p < .0001). Men recruited via radio were more likely to be AA (p<0.001), less educated (p=0.003), not married or partnered (p=0.007), and have no FH of PCA (p<0.001). Men recruited via referrals had higher incomes (p=0.007). Men recruited via referral were more likely to attend their initial PRAP visit than those recruited by radio or other methods (χ2 = 27.08, p < .0001). Conclusions This comprehensive analysis finds that radio leads to higher recruitment of AA men with lower socioeconomic status. However, these are the high-risk men that have lower show rates for PCA screening. Targeted motivational measures need to be studied to improve show rates for PCA risk assessment for these high-risk men. PMID:19758657

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

Biodrying of sewage sludge: kinetics of volatile solids degradation under different initial moisture contents and air-flow rates.

PubMed

Villegas, Manuel; Huiliñir, Cesar

2014-12-01

This study focuses on the kinetics of the biodegradation of volatile solids (VS) of sewage sludge for biodrying under different initial moisture contents (Mc) and air-flow rates (AFR). For the study, a 3(2) factorial design, whose factors were AFR (1, 2 or 3L/minkgTS) and initial Mc (59%, 68% and 78% w.b.), was used. Using seven kinetic models and a nonlinear regression method, kinetic parameters were estimated and the models were analyzed with two statistical indicators. Initial Mc of around 68% increases the temperature matrix and VS consumption, with higher moisture removal at lower initial Mc values. Lower AFRs gave higher matrix temperatures and VS consumption, while higher AFRs increased water removal. The kinetic models proposed successfully simulate VS biodegradation, with root mean square error (RMSE) between 0.007929 and 0.02744, and they can be used as a tool for satisfactory prediction of VS in biodrying. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generalized quantum kinetic expansion: Higher-order corrections to multichromophoric Förster theory

NASA Astrophysics Data System (ADS)

Wu, Jianlan; Gong, Zhihao; Tang, Zhoufei

2015-08-01

For a general two-cluster energy transfer network, a new methodology of the generalized quantum kinetic expansion (GQKE) method is developed, which predicts an exact time-convolution equation for the cluster population evolution under the initial condition of the local cluster equilibrium state. The cluster-to-cluster rate kernel is expanded over the inter-cluster couplings. The lowest second-order GQKE rate recovers the multichromophoric Förster theory (MCFT) rate. The higher-order corrections to the MCFT rate are systematically included using the continued fraction resummation form, resulting in the resummed GQKE method. The reliability of the GQKE methodology is verified in two model systems, revealing the relevance of higher-order corrections.

The nano-epsilon dot method for strain rate viscoelastic characterisation of soft biomaterials by spherical nano-indentation.

PubMed

Mattei, G; Gruca, G; Rijnveld, N; Ahluwalia, A

2015-10-01

Nano-indentation is widely used for probing the micromechanical properties of materials. Based on the indentation of surfaces using probes with a well-defined geometry, the elastic and viscoelastic constants of materials can be determined by relating indenter geometry and measured load and displacement to parameters which represent stress and deformation. Here we describe a method to derive the viscoelastic properties of soft hydrated materials at the micro-scale using constant strain rates and stress-free initial conditions. Using a new self-consistent definition of indentation stress and strain and corresponding unique depth-independent expression for indentation strain rate, the epsilon dot method, which is suitable for bulk compression testing, is transformed to nano-indentation. We demonstrate how two materials can be tested with a displacement controlled commercial nano-indentor using the nano-espilon dot method (nano-ε̇M) to give values of instantaneous and equilibrium elastic moduli and time constants with high precision. As samples are tested in stress-free initial conditions, the nano-ε̇M could be useful for characterising the micro-mechanical behaviour of soft materials such as hydrogels and biological tissues at cell length scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

Suicide Following Deliberate Self-Harm.

PubMed

Olfson, Mark; Wall, Melanie; Wang, Shuai; Crystal, Stephen; Gerhard, Tobias; Blanco, Carlos

2017-08-01

The authors sought to identify risk factors for repeat self-harm and completed suicide over the following year among adults with deliberate self-harm. A national cohort of Medicaid-financed adults clinically diagnosed with deliberate self-harm (N=61,297) was followed for up to 1 year. Repeat self-harm per 1,000 person-years and suicide rates per 100,000 person-years (based on cause of death information from the National Death Index) were determined. Hazard ratios of repeat self-harm and suicide were estimated by Cox proportional hazard models. During the 12 months after nonfatal self-harm, the rate of repeat self-harm was 263.2 per 1,000 person-years and the rate of completed suicide was 439.1 per 100,000 person-years, or 37.2 times higher than in a matched general population cohort. The hazard of suicide was higher after initial self-harm events involving violent as compared with nonviolent methods (hazard ratio=7.5, 95% CI=5.5-10.1), especially firearms (hazard ratio=15.86, 95% CI=10.7-23.4; computed with poisoning as reference), and to a lesser extent after events of patients who had recently received outpatient mental health care (hazard ratio=1.6, 95% CI=1.2-2.0). Compared with self-harm patients using nonviolent methods, those who used violent methods were at significantly increased risk of suicide during the first 30 days after the initial event (hazard ratio=17.5, 95% CI=11.2-27.3), but not during the following 335 days. Adults treated for deliberate self-harm frequently repeat self-harm in the following year. Patients who use a violent method for their initial self-harm, especially firearms, have an exceptionally high risk of suicide, particularly right after the initial event, which highlights the importance of careful assessment and close follow-up of this group.

On determining dose rate constants spectroscopically

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

Rodriguez, M.; Rogers, D. W. O.

2013-01-15

Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of {sup 125}I and {sup 103}Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089-6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated {sup 125}I and {sup 103}Pd sources. Methods: Spectra generated by 14 {sup 125}I and 6 {sup 103}Pd seedsmore » were calculated in vacuo at 10 cm from the source in a 2.7 Multiplication-Sign 2.7 Multiplication-Sign 0.05 cm{sup 3} voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the {sup 125}I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for {sup 103}Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were Less-Than-Or-Slanted-Equal-To 0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in {sup 125}I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The {sup 103}Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different investigations are in much better agreement with the calculations using the NCRP Report 58 and NNDC(2000) initial spectra with average discrepancies of 0.9% and 1.7% for the {sup 125}I and {sup 103}Pd seeds, respectively. However, there are no differences in the calculated TG-43U1 brachytherapy parameters using either initial spectrum in both cases. Similarly, there were no differences outside the statistical uncertainties of 0.1% or 0.2%, in the average energy, air kerma/history, dose rate/history, and dose rate constant when calculated using either the full photon spectrum or the main-peaks-only spectrum. Conclusions: Our calculated dose rate constants based on using the calculated on-axis spectrum and a line or dual-point source model are in excellent agreement (0.5% on average) with the values of Chen and Nath, verifying the accuracy of their more approximate method of going from the spectrum to the dose rate constant. However, the dose rate constants based on full seed models differ by between +4.6% and -1.5% from those based on the line or dual-point source approximations. These results suggest that the main value of spectroscopic measurements is to verify full Monte Carlo models of the seeds by comparison to the calculated spectra.« less

Rates and determinants of early initiation of breastfeeding and exclusive breast feeding at 42 days postnatal in six low and middle-income countries: A prospective cohort study

PubMed Central

2015-01-01

Background Early initiation of breastfeeding after birth and exclusive breastfeeding through six months of age confers many health benefits for infants; both are crucial high impact, low-cost interventions. However, determining accurate global rates of these crucial activities has been challenging. We use population-based data to describe: (1) rates of early initiation of breastfeeding (defined as within 1 hour of birth) and of exclusive breastfeeding at 42 days post-partum; and (2) factors associated with failure to initiate early breastfeeding and exclusive breastfeeding at 42 days post-partum. Methods Prospectively collected data from women and their live-born infants enrolled in the Global Network’s Maternal and Newborn Health Registry between January 1, 2010-December 31, 2013 included women-infant dyads in 106 geographic areas (clusters) at 7 research sites in 6 countries (Kenya, Zambia, India [2 sites], Pakistan, Argentina and Guatemala). Rates and risk factors for failure to initiate early breastfeeding were investigated for the entire cohort and rates and risk factors for failure to maintain exclusive breastfeeding was assessed in a sub-sample studied at 42 days post-partum. Result A total of 255,495 live-born women-infant dyads were included in the study. Rates and determinants for the exclusive breastfeeding sub-study at 42 days post-partum were assessed from among a sub-sample of 105,563 subjects. Although there was heterogeneity by site, and early initiation of breastfeeding after delivery was high, the Pakistan site had the lowest rates of early initiation of breastfeeding. The Pakistan site also had the highest rate of lack of exclusive breastfeeding at 42 days post-partum. Across all regions, factors associated with failure to initiate early breastfeeding included nulliparity, caesarean section, low birth weight, resuscitation with bag and mask, and failure to place baby on the mother’s chest after delivery. Factors associated with failure to achieve exclusive breastfeeding at 42 days varied across the sites. The only factor significant in all sites was multiple gestation. Conclusions In this large, prospective, population-based, observational study, rates of both early initiation of breastfeeding and exclusive breastfeeding at 42 days post-partum were high, except in Pakistan. Factors associated with these key breastfeeding indicators should assist with more effective strategies to scale-up these crucial public health interventions. Trial registration Registration at the Clinicaltrials.gov website (ID# NCT01073475). PMID:26063291

Polarization control of spontaneous emission for rapid quantum-state initialization

NASA Astrophysics Data System (ADS)

DiLoreto, C. S.; Rangan, C.

2017-04-01

We propose an efficient method to selectively enhance the spontaneous emission rate of a quantum system by changing the polarization of an incident control field, and exploiting the polarization dependence of the system's spontaneous emission rate. This differs from the usual Purcell enhancement of spontaneous emission rates as it can be selectively turned on and off. Using a three-level Λ system in a quantum dot placed in between two silver nanoparticles and a linearly polarized, monochromatic driving field, we present a protocol for rapid quantum state initialization, while maintaining long coherence times for control operations. This process increases the overall amount of time that a quantum system can be effectively utilized for quantum operations, and presents a key advance in quantum computing.

Investigating the Mechanism of Heteroaromatic Decarboxylation Using Solvent Kinetic Isotope Effects and Eyring Transition-State Theory

ERIC Educational Resources Information Center

Mundle, Scott O. C.; Opinska, Liliana Guevara; Kluger, Ronald; Dicks, Andrew P.

2011-01-01

An upper-level mechanistic organic experiment is outlined where undergraduates measure kinetic rate constants for decarboxylation of pyrrole-2-carboxylic acid by the initial-rates method. UV spectroscopy is used to monitor reactant disappearance in both hydrochloric acid and deuterium chloride at different temperatures. Individual data are pooled…

Nursery response of Acacia koa seedlings to container size, irrigation method, and fertilization rate

Treesearch

R. Kasten Dumroese; Anthony S. Davis; Douglass F. Jacobs

2011-01-01

Planting koa (Acacia koa A. Gray) in Hawai'i, USA aids in restoration of disturbed sites essential to conservation of endemic species. Survival and growth of planted seedlings under vegetative competition typically increases with initial plant size. Increasing container size and fertilizer rate may produce larger seedlings, but high fertilization can lead to...

14 CFR 121.420 - Flight navigators: Initial and transition ground training.

Code of Federal Regulations, 2013 CFR

2013-01-01

... limitations and methods of compensation. (6) Cruise control charts and data, including fuel consumption rates... type airplane: (1) Limitations on climb, cruise, and descent speeds. (2) Each item of navigational...

14 CFR 121.420 - Flight navigators: Initial and transition ground training.

Code of Federal Regulations, 2012 CFR

2012-01-01

... limitations and methods of compensation. (6) Cruise control charts and data, including fuel consumption rates... type airplane: (1) Limitations on climb, cruise, and descent speeds. (2) Each item of navigational...

Initial dissolution kinetics of cocrystal of carbamazepine with nicotinamide.

PubMed

Hattori, Yusuke; Sato, Maiko; Otsuka, Makoto

2015-11-01

Objectives of this study are investigating the initial dissolution kinetics of the cocrystal of carbamazepine (CBZ) with nicotinamide (NIC) and understanding its initial dissolution process. Cocrystal solids of CBZ with NIC were prepared by co-milling and solvent evaporation methods. The formation of cocrystal solid was verified via X-ray diffraction measurement. Dissolution tests of the solids were performed using an original flow cell and ultraviolet-visible spectroscopic detector. The spectra monitored in situ were analyzed to determine the dissolved compounds separately using the classical least squares regression method. The initial dissolution profiles were interpreted using simultaneous model of dissolution and phase changes. In the initial dissolution, CBZ in the cocrystal structure dissolved in water and it was suggested that CBZ reached a metastable intermediate state simultaneously with dissolution. The cocrystal solid prepared by solvent evaporation provided a higher rate constant of the phase change than that prepared by co-milling. Our results thus support the use of evaporation as the method of choice to produce ordered cocrystal structures. We suggest that CBZ forms dihydrate during the dissolution process; however, during the initial phase of dissolution, CBZ changes to a metastable intermediate phase. © 2015 Royal Pharmaceutical Society.

Effects of syllable-initial voicing and speaking rate on the temporal characteristics of monosyllabic words.

PubMed

Allen, J S; Miller, J L

1999-10-01

Two speech production experiments tested the validity of the traditional method of creating voice-onset-time (VOT) continua for perceptual studies in which the systematic increase in VOT across the continuum is accompanied by a concomitant decrease in the duration of the following vowel. In experiment 1, segmental durations were measured for matched monosyllabic words beginning with either a voiced stop (e.g., big, duck, gap) or a voiceless stop (e.g., pig, tuck, cap). Results from four talkers showed that the change from voiced to voiceless stop produced not only an increase in VOT, but also a decrease in vowel duration. However, the decrease in vowel duration was consistently less than the increase in VOT. In experiment 2, results from four new talkers replicated these findings at two rates of speech, as well as highlighted the contrasting temporal effects on vowel duration of an increase in VOT due to a change in syllable-initial voicing versus a change in speaking rate. It was concluded that the traditional method of creating VOT continua for perceptual experiments, although not perfect, approximates natural speech by capturing the basic trade-off between VOT and vowel duration in syllable-initial voiced versus voiceless stop consonants.

Consistent initial conditions for the Saint-Venant equations in river network modeling

NASA Astrophysics Data System (ADS)

Yu, Cheng-Wei; Liu, Frank; Hodges, Ben R.

2017-09-01

Initial conditions for flows and depths (cross-sectional areas) throughout a river network are required for any time-marching (unsteady) solution of the one-dimensional (1-D) hydrodynamic Saint-Venant equations. For a river network modeled with several Strahler orders of tributaries, comprehensive and consistent synoptic data are typically lacking and synthetic starting conditions are needed. Because of underlying nonlinearity, poorly defined or inconsistent initial conditions can lead to convergence problems and long spin-up times in an unsteady solver. Two new approaches are defined and demonstrated herein for computing flows and cross-sectional areas (or depths). These methods can produce an initial condition data set that is consistent with modeled landscape runoff and river geometry boundary conditions at the initial time. These new methods are (1) the pseudo time-marching method (PTM) that iterates toward a steady-state initial condition using an unsteady Saint-Venant solver and (2) the steady-solution method (SSM) that makes use of graph theory for initial flow rates and solution of a steady-state 1-D momentum equation for the channel cross-sectional areas. The PTM is shown to be adequate for short river reaches but is significantly slower and has occasional non-convergent behavior for large river networks. The SSM approach is shown to provide a rapid solution of consistent initial conditions for both small and large networks, albeit with the requirement that additional code must be written rather than applying an existing unsteady Saint-Venant solver.

Utilization of cardiac computed tomography angiography and outpatient invasive coronary angiography in Ontario, Canada.

PubMed

Roifman, Idan; Rezai, Mohammad R; Wijeysundera, Harindra C; Chow, Benjamin J W; Wright, Graham A; Tu, Jack V

2015-01-01

Cardiac computed tomography angiography (coronary CTA) has emerged as a non-invasive method of diagnosing coronary artery disease. The extent of utilization and uptake of this technology since initiation of its funding by the government of Ontario is unknown. The aim of our study was to examine coronary CTA utilization and the rates of elective invasive coronary angiography and revascularization before and after funding initiation. We studied all coronary CTAs performed on adults in Ontario after initiation of funding. We also used an interrupted time series analysis to compare the average monthly rates of invasive angiography and revascularization before and after initiation of funding. There was an initial steep increase in age-and sex-standardized rates of coronary CTA from 5.0 to 11.4/100,000 over the first two quarters after funding initiation. Afterwards, there was a gradual increase in utilization from 11.4 to 17.1/100,000 over two subsequent calendar years. There was a significant reduction in both the mean monthly outpatient invasive coronary angiography (from 20.7 to 19.9 per 100,000 (p = 0.0004)) and revascularization (from 4.9 to 4.4 per 100,000 (p < 0.0001)) rates in the three years following introduction of the coronary CTA billing code as compared to the three prior to its introduction. Since the introduction of coronary CTA funding in Ontario, there has been a steady and controlled increase in its utilization. The increasing use of coronary CTA was associated with a reduction in both the rates of invasive angiography and revascularization. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

76 FR 17846 - Objective Merit Review of Discretionary Financial Assistance and Other Transaction Authority...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-31

... initiative, and the idea, method or approach would be ineligible for assistance under a recent, current, or... strengths and weaknesses of the applications. ii. An overall consensus rating will be determined for each... unsolicited proposal and represents a unique or innovative idea, method, or approach which would not be...

White Dwarf Asteroseismology and the 12C(α,γ)16O Rate

NASA Astrophysics Data System (ADS)

Metcalfe, Travis S.

2003-04-01

Due to a new global analysis method, it is now possible to measure the internal composition of pulsating white dwarf stars, even with relatively simple theoretical models. The precise internal mixture of carbon and oxygen is the largest single source of uncertainty in ages derived from white dwarf cosmochronometry, and it contains information about the rate of the astrophysically important, but experimentally uncertain, 12C(α,γ)16O nuclear reaction. Recent determinations of the internal composition and structure of two helium-atmosphere variable (DBV) white dwarf stars, GD 358 and CBS 114, initially led to conflicting implied rates for the 12C(α,γ)16O reaction. If both stars were formed through single-star evolution, then the initial analyses of their pulsation frequencies must have differed in some systematic way. I present improved fits to the two sets of pulsation data, resolving the tension between the initial results and leading to a value for the 12C(α,γ)16O reaction rate that is consistent with recent laboratory measurements.

The rate of fatality and demographic characteristics associated with various suicide methods: a community-based study in Northern Taiwan.

PubMed

Lee, Chun-Yi; Wu, Ya-Wen; Chen, Chih-Ken; Wang, Liang-Jen

2014-01-01

Understanding lethality and risk factors of suicide methods is an initial step in suicide prevention. To investigate the fatality rate and demographic characteristics of various suicide methods. This study enrolled consecutive individuals with episodes of suicide attempts registered in a surveillance database in a city with a high rate of suicide mortality in Taiwan, from January 1, 2006, to December 31, 2010. In total, 3,089 suicide attempt events (including 2,583 nonfatal suicides and 506 completed suicides) occurred during the study period. Overall, the fatality rate of suicides was 16.4%. Charcoal burning accounted for the most suicide deaths (37.6%), with a fatality rate of 50.1%. Suicide by hanging carried the highest fatality rate (81.2%). Males tended to choose more lethal methods and had higher fatality rates compared with females. Elders and married persons were less likely to attempt suicide by charcoal burning. The case fatality ratio increased along with age among suicide attempts, but not in those using charcoal burning. The choice of suicide methods and lethality might be influenced by one's demographic characteristics. RESULTS from this study may provide clues for establishing suicide prevention strategies such as restricting access to common lethal suicide methods in the high-risk group.

Scalable Production of Glioblastoma Tumor-initiating Cells in 3 Dimension Thermoreversible Hydrogels

NASA Astrophysics Data System (ADS)

Li, Qiang; Lin, Haishuang; Wang, Ou; Qiu, Xuefeng; Kidambi, Srivatsan; Deleyrolle, Loic P.; Reynolds, Brent A.; Lei, Yuguo

2016-08-01

There is growing interest in developing drugs that specifically target glioblastoma tumor-initiating cells (TICs). Current cell culture methods, however, cannot cost-effectively produce the large numbers of glioblastoma TICs required for drug discovery and development. In this paper we report a new method that encapsulates patient-derived primary glioblastoma TICs and grows them in 3 dimension thermoreversible hydrogels. Our method allows long-term culture (~50 days, 10 passages tested, accumulative ~>1010-fold expansion) with both high growth rate (~20-fold expansion/7 days) and high volumetric yield (~2.0 × 107 cells/ml) without the loss of stemness. The scalable method can be used to produce sufficient, affordable glioblastoma TICs for drug discovery.

The influence of microwave-assisted drying techniques on the rehydration behavior of blueberries (Vaccinium corymbosum L.).

PubMed

Zielinska, Magdalena; Markowski, Marek

2016-04-01

The aim of this study was to determine the effect of: (a) different drying methods, (b) hot air temperature in a convection oven, and (c) the moisture content of fruits dehydrated by multi-stage drying which involves a transition between different stages of drying, on the rehydration kinetics of dry blueberries. Models describing rehydration kinetics were also studied. Blueberries dehydrated by multi-stage microwave-assisted drying, which involved a hot air pre-drying step at 80 °C until the achievement of a moisture content of 1.95 kg H2O kg(-1)DM, were characterized by significantly higher rates of initial and successive rehydration as well as smaller initial loss of soluble solids in comparison with the samples dried by other methods. The highest initial rehydration rate and the smallest loss of soluble solids after 30 min of soaking were determined at 0.46 min(-1) and 0.29 kg DM kg(-1)DM, respectively. The Peleg model and the first-order-kinetic model fit the experimental data well. Copyright © 2015 Elsevier Ltd. All rights reserved.

Concentration dependence of biotransformation in fish liver S9: Optimizing substrate concentrations to estimate hepatic clearance for bioaccumulation assessment.

PubMed

Lo, Justin C; Allard, Gayatri N; Otton, S Victoria; Campbell, David A; Gobas, Frank A P C

2015-12-01

In vitro bioassays to estimate biotransformation rate constants of contaminants in fish are currently being investigated to improve bioaccumulation assessments of hydrophobic contaminants. The present study investigates the relationship between chemical substrate concentration and in vitro biotransformation rate of 4 environmental contaminants (9-methylanthracene, pyrene, chrysene, and benzo[a]pyrene) in rainbow trout (Oncorhynchus mykiss) liver S9 fractions and methods to determine maximum first-order biotransformation rate constants. Substrate depletion experiments using a series of initial substrate concentrations showed that in vitro biotransformation rates exhibit strong concentration dependence, consistent with a Michaelis-Menten kinetic model. The results indicate that depletion rate constants measured at initial substrate concentrations of 1 μM (a current convention) could underestimate the in vitro biotransformation potential and may cause bioconcentration factors to be overestimated if in vitro biotransformation rates are used to assess bioconcentration factors in fish. Depletion rate constants measured using thin-film sorbent dosing experiments were not statistically different from the maximum depletion rate constants derived using a series of solvent delivery-based depletion experiments for 3 of the 4 test chemicals. Multiple solvent delivery-based depletion experiments at a range of initial concentrations are recommended for determining the concentration dependence of in vitro biotransformation rates in fish liver fractions, whereas a single sorbent phase dosing experiment may be able to provide reasonable approximations of maximum depletion rates of very hydrophobic substances. © 2015 SETAC.

Electrokinetic remediation prefield test methods

NASA Technical Reports Server (NTRS)

Hodko, Dalibor (Inventor)

2000-01-01

Methods for determining the parameters critical in designing an electrokinetic soil remediation process including electrode well spacing, operating current/voltage, electroosmotic flow rate, electrode well wall design, and amount of buffering or neutralizing solution needed in the electrode wells at operating conditions are disclosed These methods are preferably performed prior to initiating a full scale electrokinetic remediation process in order to obtain efficient remediation of the contaminants.

A simplified method for assessing particle deposition rate in aircraft cabins

NASA Astrophysics Data System (ADS)

You, Ruoyu; Zhao, Bin

2013-03-01

Particle deposition in aircraft cabins is important for the exposure of passengers to particulate matter, as well as the airborne infectious diseases. In this study, a simplified method is proposed for initial and quick assessment of particle deposition rate in aircraft cabins. The method included: collecting the inclined angle, area, characteristic length, and freestream air velocity for each surface in a cabin; estimating the friction velocity based on the characteristic length and freestream air velocity; modeling the particle deposition velocity using the empirical equation we developed previously; and then calculating the particle deposition rate. The particle deposition rates for the fully-occupied, half-occupied, 1/4-occupied and empty first-class cabin of the MD-82 commercial airliner were estimated. The results show that the occupancy did not significantly influence the particle deposition rate of the cabin. Furthermore, the simplified human model can be used in the assessment with acceptable accuracy. Finally, the comparison results show that the particle deposition rate of aircraft cabins and indoor environments are quite similar.

Can simple mobile phone applications provide reliable counts of respiratory rates in sick infants and children? An initial evaluation of three new applications.

PubMed

Black, James; Gerdtz, Marie; Nicholson, Pat; Crellin, Dianne; Browning, Laura; Simpson, Julie; Bell, Lauren; Santamaria, Nick

2015-05-01

Respiratory rate is an important sign that is commonly either not recorded or recorded incorrectly. Mobile phone ownership is increasing even in resource-poor settings. Phone applications may improve the accuracy and ease of counting of respiratory rates. The study assessed the reliability and initial users' impressions of four mobile phone respiratory timer approaches, compared to a 60-second count by the same participants. Three mobile applications (applying four different counting approaches plus a standard 60-second count) were created using the Java Mobile Edition and tested on Nokia C1-01 phones. Apart from the 60-second timer application, the others included a counter based on the time for ten breaths, and three based on the time interval between breaths ('Once-per-Breath', in which the user presses for each breath and the application calculates the rate after 10 or 20 breaths, or after 60s). Nursing and physiotherapy students used the applications to count respiratory rates in a set of brief video recordings of children with different respiratory illnesses. Limits of agreement (compared to the same participant's standard 60-second count), intra-class correlation coefficients and standard errors of measurement were calculated to compare the reliability of the four approaches, and a usability questionnaire was completed by the participants. There was considerable variation in the counts, with large components of the variation related to the participants and the videos, as well as the methods. None of the methods was entirely reliable, with no limits of agreement better than -10 to +9 breaths/min. Some of the methods were superior to the others, with ICCs from 0.24 to 0.92. By ICC the Once-per-Breath 60-second count and the Once-per-Breath 20-breath count were the most consistent, better even than the 60-second count by the participants. The 10-breath approaches performed least well. Users' initial impressions were positive, with little difference between the applications found. This study provides evidence that applications running on simple phones can be used to count respiratory rates in children. The Once-per-Breath methods are the most reliable, outperforming the 60-second count. For children with raised respiratory rates the 20-breath version of the Once-per-Breath method is faster, so it is a more suitable option where health workers are under time pressure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Perchlorate reduction by autotrophic bacteria in the presence of zero-valent iron.

PubMed

Yu, Xueyuan; Amrhein, Christopher; Deshusses, Marc A; Matsumoto, Mark R

2006-02-15

A series of batch experiments were performed to study the combination of zero-valent iron (ZVI) with perchlorate-reducing microorganisms (PRMs) to remove perchlorate from groundwater. In this method, H2 produced during the process of iron corrosion by water is used by PRMs as an electron donor to reduce perchlorate to chloride. Perchlorate degradation rates followed Monod kinetics, with a normalized maximum utilization rate (rmax) of 9200 microg g(-1) (dry wt) h(-1) and a half-velocity constant (Ks) of 8900 microg L(-1). The overall rate of perchlorate reduction was affected by the biomass density within the system. An increase in the OD600 from 0.025 to 0.08 led to a corresponding 4-fold increase of perchlorate reduction rate. PRM adaptation to the local environment and initiation of perchlorate reduction was rapid under neutral pH conditions. At the initial OD600 of 0.015, perchlorate reduction followed pseudo-first-order reaction rates with constants of 0.059 and 0.033 h(-1) at initial pH 7 and 8, respectively. Once perchlorate reduction was established, the bioreductive process was insensitive to the increases of pH from near neutral to 9.0. In the presence of nitrate, perchlorate reduction rate was reduced, but not inhibited completely.

Quantum kinetic expansion in the spin-boson model: Matrix formulation and system-bath factorized initial state.

PubMed

Gong, Zhihao; Tang, Zhoufei; Wang, Haobin; Wu, Jianlan

2017-12-28

Within the framework of the hierarchy equation of motion (HEOM), the quantum kinetic expansion (QKE) method of the spin-boson model is reformulated in the matrix representation. The equivalence between the two formulations (HEOM matrices and quantum operators) is numerically verified from the calculation of the time-integrated QKE rates. The matrix formulation of the QKE is extended to the system-bath factorized initial state. Following a one-to-one mapping between HEOM matrices and quantum operators, a quantum kinetic equation is rederived. The rate kernel is modified by an extra term following a systematic expansion over the site-site coupling. This modified QKE is numerically tested for its reliability by calculating the time-integrated rate and non-Markovian population kinetics. For an intermediate-to-strong dissipation strength and a large site-site coupling, the population transfer is found to be significantly different when the initial condition is changed from the local equilibrium to system-bath factorized state.

Uptake of Free HPV Vaccination among Young Women: A Comparison of Rural versus Urban Rates

ERIC Educational Resources Information Center

Crosby, Richard A.; Casey, Baretta R.; Vanderpool, Robin; Collins, Tom; Moore, Gregory R.

2011-01-01

Purpose: To contrast rates of initial HPV vaccine uptake, offered at no cost, between a rural clinic, a rural community college, and an urban college clinic and to identify rural versus urban differences in uptake of free booster doses. Methods: Young rural women attending rural clinics (n = 246), young women attending a rural community college (n…

Effect of High Strain-Rate Deformation and Aging Temperature on the Evolution of Structure, Microhardness, and Wear Resistance of Low-Alloyed Cu-Cr-Zr Alloy

NASA Astrophysics Data System (ADS)

Kheifets, A. E.; Khomskaya, I. V.; Korshunov, L. G.; Zel'dovich, V. I.; Frolova, N. Yu.

2018-04-01

The effect of the preliminary high strain-rate deformation, performed via the method of dynamic channel-angular pressing (DCAP), and subsequent annealings on the tribological properties of a dispersionhardened Cu-0.092 wt % Cr-0.086 wt % Zr alloy has been investigated. It has been shown that the surfacelayer material of the alloy with a submicrocrystalline (SMC) structure obtained by the DCAP method can be strengthened using severe plastic deformation by sliding friction at the expense of creating a nanocrystalline structure with crystallites of 15-60 nm in size. It has been shown that the SMC structure obtained by the high strain-rate DCAP deformation decreases the wear rate of the samples upon sliding friction by a factor of 1.4 compared to the initial coarse-grained state. The maximum values of the microhardness and minimum values of the coefficient of friction and shear strength have been obtained in the samples preliminarily subjected to DCAP and aging at 400°C. The attained level of microhardness is 3350 MPa, which exceeds the microhardness of the alloy in the initial coarse-grained state by five times.

Using CFD Techniques to Predict Slosh Force Frequency and Damping Rate

NASA Technical Reports Server (NTRS)

Marsell, Brandon; Gangadharan, Sathya; Chatman, Yadira; Sudermann, James

2009-01-01

Resonant effects and energy dissipation due to sloshing fuel inside propellant tanks are problems that arise in the initial design of any spacecraft or launch vehicle. A faster and more reliable method for calculating these effects during the design stages is needed. Using Computational Fluid Dynamics (CFD) techniques, a model of these fuel tanks can be created and used to predict important parameters such as resonant slosh frequency and damping rate. This initial study addresses the case of free surface slosh. Future studies will focus on creating models for tanks fitted with propellant management devices (PMD) such as diaphragms and baffles.

Radical Polymerization of Diene Hydrocarbons in a Presence of Peroxide of Hydrogen and Solvent. 1. Effectiveness of Initiation and Rate of Expansion H2O2 during Oligomerization in Metallic Equipment

DTIC Science & Technology

1990-04-10

the hydroxyl groups. These are liquid oligobutadienes of brand R-15M and R-45M (firm "Sinclair Retgochemical Suc."/OSA) [5, 6, 10] and hydroxyl... ionic mechanism. Most promising, in view of simplicity and cheapness, is considered the I DOC - 90010000 PAGE - method of the radical polymerization of...Initiators of polimerization in this method are the hydroxyl radicals, which are generated during the homolytic decomposition of peroxide of hydrogen PDO

High initiation and long duration of breastfeeding despite absence of early skin-to-skin contact in Karen refugees on the Thai-Myanmar border: a mixed methods study

PubMed Central

2012-01-01

Background Early skin-to-skin contact (SSC) after birth is recommended as part of the United Nations Children’s Fund (UNICEF) baby friendly health initiative to promote optimum breastfeeding. This paper reports rates of breastfeeding initiation and duration in a low resource environment, where early SSC is not practised, and explores views of pregnant women and midwives surrounding breastfeeding and swaddling. Methods Data from records from a single hospital on the Thai-Myanmar border where refugee women gave birth during a one-year period (2010) were used to determine breastfeeding initiation rates and the time of the first breastfeed, and duration of breastfeeding of the previous alive child in multigravidae. Focus group discussions (FGD) were conducted to obtain information from pregnant women attending antenatal care about their intended or previous duration of breastfeeding and views on breastfeeding. Interviews with local midwives explored reasons for high rates of breastfeeding in this setting and the practice of newborn swaddling. Results Of 1404 live births in 2010 in Maela refugee camp there were 982 evaluable mother-newborn pairs, including 80 infants born before 37 weeks gestation. Initiation of breastfeeding within the first hour after birth and exclusive breastfeeding at discharge in term mother-newborn pairs was 91.2% (823/902) and 99.3% (896/902); and before 37 weeks gestation, 48.8% (39/80) and 98.8% (79/80). Reported duration of previous breastfeeding was 19 (range 2 to 72) months. During FGD all primigravidae (n = 17) intended to breastfeed and all multigravidae (n = 33) had previously breastfed; expected or previous duration of feeding was for more than one year or longer. The major theme identified during FGD was breastfeeding is “good”. Women stated their intention to breastfeed with certainty. This certainty was echoed during the interviews with midwifery staff. SSC requires a delay in early swaddling that in Karen people, with animistic beliefs, could risk loss of the spirit of the newborn or attract malevolent spirits. Conclusions In a population with a strong culture of breastfeeding and robust breastfeeding practices, high rates of initiation and duration of breastfeeding were found despite a lack of early skin-to-skin contact. Local preferences, traditions and practices that protect, support and maintain high rates of breastfeeding should be promoted. PMID:23241099

Can Mentors Channeling Youthful Minority and Female Students into Optical Sciences be Funded and Fostered by Use of Mc Leod's Patent-pending Naturoptics?

NASA Astrophysics Data System (ADS)

de Sousa, Beatriz; Ferreira, Nadja; Mc Leod, Roger D.

2007-04-01

We wish to begin the repair of impaired youthful vision, using methods taught by Roger D. Mc Leod, to his adult associates for their own, restricted, personal use. Certain nations could benefit if we are able extend the development of franchise-protected and pending patent-protected methods around the globe. We prefer concentrating our initial efforts among young minority and female students, particularly those involving some indigenous heritage. This approach will be using applied optics/Naturoptics and other applied mathematics/sciences as corrective and financially motivational driving tools. Funding, accessible without time-consuming red tape, could be from money generated by Naturoptics , at a rate, for initially visually-impaired mentors, who will learn the method, free, as they are repaired. Mentored teaching will earn an equivalent of half the usual rate of 95 per individual initial 25-minute session, provided that there are satisfactory non-disclosure agreements. Improvements are guaranteed, on Snellen charts, or other equivalent vision charts, of one line per session, after the beginning visit, or the session is free. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.3

Manipulation of three-dimensional Richtmyer-Meshkov instability by initial interfacial principal curvatures

NASA Astrophysics Data System (ADS)

Guan, Ben; Zhai, Zhigang; Si, Ting; Lu, Xiyun; Luo, Xisheng

2017-03-01

The characteristics of three-dimensional (3D) Richtmyer-Meshkov instability (RMI) in the early stages are studied numerically. By designing 3D interfaces that initially possess various identical and opposite principal curvature combinations, the growth rate of perturbations can be effectively manipulated. The weighted essentially nonoscillatory scheme and the level set method combined with the real ghost fluid method are used to simulate the flow. The results indicate that the interface development and the shock propagation in 3D cases are much more complicated than those in 2D case, and the evolution of 3D interfaces is heavily dependent on the initial interfacial principal curvatures. The 3D structure of wave patterns induces high pressure zones in the flow field, and the pressure oscillations change the local instabilities of interfaces. In the linear stages, the perturbation growth rate follows regularity as the interfacial principal curvatures vary, which is further predicted by the stability theory of 2D and 3D interfaces. It is also found that hysteresis effects exist at the onset of the linear stages in the 3D case for the same initial perturbations as the 2D case, resulting in different evolutions of 3D RMI in the nonlinear stages.

Very high pressure liquid chromatography using fully porous particles: quantitative analysis of fast gradient separations without post-run times.

PubMed

Stankovich, Joseph J; Gritti, Fabrice; Stevenson, Paul G; Beaver, Lois Ann; Guiochon, Georges

2014-01-10

Using a column packed with fully porous particles, four methods for controlling the flow rates at which gradient elution runs are conducted in very high pressure liquid chromatography (VHPLC) were tested to determine whether reproducible thermal conditions could be achieved, such that subsequent analyses would proceed at nearly the same initial temperature. In VHPLC high flow rates are achieved, producing fast analyses but requiring high inlet pressures. The combination of high flow rates and high inlet pressures generates local heat, leading to temperature changes in the column. Usually in this case a post-run time is input into the analytical method to allow the return of the column temperature to its initial state. An alternative strategy involves operating the column without a post-run equilibration period and maintaining constant temperature variations for subsequent analysis after conducting one or a few separations to bring the column to a reproducible starting temperature. A liquid chromatography instrument equipped with a pressure controller was used to perform constant pressure and constant flow rate VHPLC separations. Six replicate gradient separations of a nine component mixture consisting of acetophenone, propiophenone, butyrophenone, valerophenone, hexanophenone, heptanophenone, octanophenone, benzophenone, and acetanilide dissolved in water/acetonitrile (65:35, v/v) were performed under various experimental conditions: constant flow rate, two sets of constant pressure, and constant pressure operation with a programmed flow rate. The relative standard deviations of the response factors for all the analytes are lower than 5% across the methods. Programming the flow rate to maintain a fairly constant pressure instead of using instrument controlled constant pressure improves the reproducibility of the retention times by a factor of 5, when plotting the chromatograms in time. Copyright © 2013 Elsevier B.V. All rights reserved.

Growth of graphene films from non-gaseous carbon sources

DOEpatents

Tour, James; Sun, Zhengzong; Yan, Zheng; Ruan, Gedeng; Peng, Zhiwei

2015-08-04

In various embodiments, the present disclosure provides methods of forming graphene films by: (1) depositing a non-gaseous carbon source onto a catalyst surface; (2) exposing the non-gaseous carbon source to at least one gas with a flow rate; and (3) initiating the conversion of the non-gaseous carbon source to the graphene film, where the thickness of the graphene film is controllable by the gas flow rate. Additional embodiments of the present disclosure pertain to graphene films made in accordance with the methods of the present disclosure.

Evaluating the 'Focus on Normal Birth and Reducing Caesarean section Rates Rapid Improvement Programme': A mixed method study in England.

PubMed

Marshall, Joyce L; Spiby, Helen; McCormick, Felicia

2015-02-01

caesarean section plays an important role in ensuring safety of mother and infant but rising rates are not accompanied by measurable improvements in maternal or neonatal mortality or morbidity. The 'Focus on Normal Birth and Reducing Caesarean section Rates Rapid Improvement Programme' was a facilitative initiative developed to promote opportunities for normal birth and reduce caesarean section rates in England. to evaluate the 'Focus on Normal Birth and Reducing Caesarean section Rates' programme, by assessment of: impact on caesarean section rates, use of service improvements tools and participants׳ perceptions of factors that sustain or hinder work within participating maternity units. a mixed methods approach included analysis of mode of birth data, web-based questionnaires and in-depth semi-structured telephone interviews. twenty Hospital Trusts in England (selected from 68 who applied) took part in the 'Focus on Normal Birth and Reducing Caesarean section Rates Rapid Improvement Programme' initiative. In each hospital Trust, the head of midwifery, an obstetrician, the relevant lead for organisational development, a supervisor of midwives, or a clinical midwife and a service user representative were invited to participate in the independent evaluation. collection and analysis of mode of birth data from 20 participating hospital Trusts, web-based questionnaires administered to key individuals in all 20 Trusts and in-depth semi-structured telephone interviews conducted with key individuals in a sample of six Trusts. there was a marginal decline of 0.5% (25.9% from 26.4%) in mean total caesarean section rate in the period 1 January 2009 to 31 January 2010 compared to the baseline period (1 July-31 December 2008). Reduced total caesarean section rates were achieved in eight trusts, all with higher rates at the beginning of the initiative. Features associated with lower caesarean section rates included a shared philosophy prioritising normal birth, clear communication across disciplines and strong leadership at a range of levels, including executive support and clinical leaders within each discipline. it is important that the philosophy and organisational context of care are examined to identify potential barriers and facilitative factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prediction of in situ root decomposition rates in an interspecific context from chemical and morphological traits

PubMed Central

Aulen, Maurice; Shipley, Bill; Bradley, Robert

2012-01-01

Background and Aims We quantitatively relate in situ root decomposition rates of a wide range of trees and herbs used in agroforestry to root chemical and morphological traits in order to better describe carbon fluxes from roots to the soil carbon pool across a diverse group of plant species. Methods In situ root decomposition rates were measured over an entire year by an intact core method on ten tree and seven herb species typical of agroforestry systems and were quantified using decay constants (k values) from Olson's single exponential model. Decay constants were related to root chemical (total carbon, nitrogen, soluble carbon, cellulose, hemicellulose, lignin) and morphological (specific root length, specific root length) traits. Traits were measured for both absorbing and non-absorbing roots. Key Results From 61 to 77 % of the variation in the different root traits and 63 % of that in root decomposition rates was interspecific. N was positively correlated, but total carbon and lignin were negatively correlated with k values. Initial root traits accounted for 75 % of the variation in interspecific decomposition rates using partial least squares regressions; partial slopes attributed to each trait were consistent with functional ecology expectations. Conclusions Easily measured initial root traits can be used to predict rates of root decomposition in soils in an interspecific context. PMID:22003237

A comparative study of turbulence decay using Navier-Stokes and a discrete particle simulation

NASA Technical Reports Server (NTRS)

Goswami, A.; Baganoff, D.; Lele, S.; Feiereisen, W.

1993-01-01

A comparative study of the two dimensional temporal decay of an initial turbulent state of flow is presented using a direct Navier-Stokes simulation and a particle method, ranging from the near continuum to more rarefied regimes. Various topics related to matching the initial conditions between the two simulations are considered. The determination of the initial velocity distribution function in the particle method was found to play an important role in the comparison. This distribution was first developed by matching the initial Navier-Stokes state of stress, but was found to be inadequate beyond the near continuum regime. An alternative approach of using the Lees two-sided Maxwellian to match the initial strain-rate is discussed. Results of the comparison of the temporal decay of mean kinetic energy are presented for a range of Knudsen numbers. As expected, good agreement was observed for the near continuum regime, but the differences found for the more rarefied conditions were unexpectedly small.

Turbulence-assisted shear exfoliation of graphene using household detergent and a kitchen blender

NASA Astrophysics Data System (ADS)

Varrla, Eswaraiah; Paton, Keith R.; Backes, Claudia; Harvey, Andrew; Smith, Ronan J.; McCauley, Joe; Coleman, Jonathan N.

2014-09-01

To facilitate progression from the lab to commercial applications, it will be necessary to develop simple, scalable methods to produce high quality graphene. Here we demonstrate the production of large quantities of defect-free graphene using a kitchen blender and household detergent. We have characterised the scaling of both graphene concentration and production rate with the mixing parameters: mixing time, initial graphite concentration, rotor speed and liquid volume. We find the production rate to be invariant with mixing time and to increase strongly with mixing volume, results which are important for scale-up. Even in this simple system, concentrations of up to 1 mg ml-1 and graphene masses of >500 mg can be achieved after a few hours mixing. The maximum production rate was ~0.15 g h-1, much higher than for standard sonication-based exfoliation methods. We demonstrate that graphene production occurs because the mean turbulent shear rate in the blender exceeds the critical shear rate for exfoliation.To facilitate progression from the lab to commercial applications, it will be necessary to develop simple, scalable methods to produce high quality graphene. Here we demonstrate the production of large quantities of defect-free graphene using a kitchen blender and household detergent. We have characterised the scaling of both graphene concentration and production rate with the mixing parameters: mixing time, initial graphite concentration, rotor speed and liquid volume. We find the production rate to be invariant with mixing time and to increase strongly with mixing volume, results which are important for scale-up. Even in this simple system, concentrations of up to 1 mg ml-1 and graphene masses of >500 mg can be achieved after a few hours mixing. The maximum production rate was ~0.15 g h-1, much higher than for standard sonication-based exfoliation methods. We demonstrate that graphene production occurs because the mean turbulent shear rate in the blender exceeds the critical shear rate for exfoliation. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03560g

Mapping of medical acronyms and initialisms to Medical Subject Headings (MeSH) across selected systems

PubMed Central

Shultz, Mary

2006-01-01

Introduction: Given the common use of acronyms and initialisms in the health sciences, searchers may be entering these abbreviated terms rather than full phrases when searching online systems. The purpose of this study is to evaluate how various MEDLINE Medical Subject Headings (MeSH) interfaces map acronyms and initialisms to the MeSH vocabulary. Methods: The interfaces used in this study were: the PubMed MeSH database, the PubMed Automatic Term Mapping feature, the NLM Gateway Term Finder, and Ovid MEDLINE. Acronyms and initialisms were randomly selected from 2 print sources. The test data set included 415 randomly selected acronyms and initialisms whose related meanings were found to be MeSH terms. Each acronym and initialism was entered into each MEDLINE MeSH interface to determine if it mapped to the corresponding MeSH term. Separately, 46 commonly used acronyms and initialisms were tested. Results: While performance differed widely, the success rates were low across all interfaces for the randomly selected terms. The common acronyms and initialisms tested at higher success rates across the interfaces, but the differences between the interfaces remained. Conclusion: Online interfaces do not always map medical acronyms and initialisms to their corresponding MeSH phrases. This may lead to inaccurate results and missed information if acronyms and initialisms are used in search strategies. PMID:17082832

Heart rate changes during electroconvulsive therapy

PubMed Central

2013-01-01

Background This observational study documented heart rate over the entire course of electrically induced seizures and aimed to evaluate the effects of stimulus electrode placement, patients' age, stimulus dose, and additional predictors. Method In 119 consecutive patients with 64 right unilateral (RUL) and 55 bifrontal (BF) electroconvulsive treatments, heart rate graphs based on beat-to-beat measurements were plotted up to durations of 130 s. Results In RUL stimulation, the initial drop in heart rate lasted for 12.5 ± 2.6 s (mean ± standard deviation). This depended on stimulus train duration, age, and baseline heart rate. In seizures induced with BF electrode placement, a sympathetic response was observed within the first few seconds of the stimulation phase (median 3.5 s). This was also the case with subconvulsive stimulations. The mean peak heart rate in all 119 treatments amounted to 135 ± 20 bpm and depended on baseline heart rate and seizure duration; electrode placement, charge dose, and age were insignificant in regression analysis. A marked decline in heart rate in connection with seizure cessation occurred in 71% of treatments. Conclusions A significant independent effect of stimulus electrode positioning on cardiac action was evident only in the initial phase of the seizures. Electrical stimulation rather than the seizure causes the initial heart rate increase in BF treatments. The data reveal no rationale for setting the stimulus doses as a function of intraictal peak heart rates (‘benchmark method’). The marked decline in heart rate at the end of most seizures is probably mediated by a baroreceptor reflex. PMID:23764036

Advantages of estimating rate corrections during dynamic propagation of spacecraft rates: Applications to real-time attitude determination of SAMPEX

NASA Technical Reports Server (NTRS)

Challa, M. S.; Natanson, G. A.; Baker, D. F.; Deutschmann, J. K.

1994-01-01

This paper describes real-time attitude determination results for the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), a gyroless spacecraft, using a Kalman filter/Euler equation approach denoted the real-time sequential filter (RTSF). The RTSF is an extended Kalman filter whose state vector includes the attitude quaternion and corrections to the rates, which are modeled as Markov processes with small time constants. The rate corrections impart a significant robustness to the RTSF against errors in modeling the environmental and control torques, as well as errors in the initial attitude and rates, while maintaining a small state vector. SAMPLEX flight data from various mission phases are used to demonstrate the robustness of the RTSF against a priori attitude and rate errors of up to 90 deg and 0.5 deg/sec, respectively, as well as a sensitivity of 0.0003 deg/sec in estimating rate corrections in torque computations. In contrast, it is shown that the RTSF attitude estimates without the rate corrections can degrade rapidly. RTSF advantages over single-frame attitude determination algorithms are also demonstrated through (1) substantial improvements in attitude solutions during sun-magnetic field coalignment and (2) magnetic-field-only attitude and rate estimation during the spacecraft's sun-acquisition mode. A robust magnetometer-only attitude-and-rate determination method is also developed to provide for the contingency when both sun data as well as a priori knowledge of the spacecraft state are unavailable. This method includes a deterministic algorithm used to initialize the RTSF with coarse estimates of the spacecraft attitude and rates. The combined algorithm has been found effective, yielding accuracies of 1.5 deg in attitude and 0.01 deg/sec in the rates and convergence times as little as 400 sec.

Automatic characterization of sleep need dissipation dynamics using a single EEG signal.

PubMed

Garcia-Molina, Gary; Bellesi, Michele; Riedner, Brady; Pastoor, Sander; Pfundtner, Stefan; Tononi, Giulio

2015-01-01

In the two-process model of sleep regulation, slow-wave activity (SWA, i.e. the EEG power in the 0.5-4 Hz frequency band) is considered a direct indicator of sleep need. SWA builds up during non-rapid eye movement (NREM) sleep, declines before the onset of rapid-eye-movement (REM) sleep, remains low during REM and the level of increase in successive NREM episodes gets progressively lower. Sleep need dissipates with a speed that is proportional to SWA and can be characterized in terms of the initial sleep need, and the decay rate. The goal in this paper is to automatically characterize sleep need from a single EEG signal acquired at a frontal location. To achieve this, a highly specific and reasonably sensitive NREM detection algorithm is proposed that leverages the concept of a single-class Kernel-based classifier. Using automatic NREM detection, we propose a method to estimate the decay rate and the initial sleep need. This method was tested on experimental data from 8 subjects who recorded EEG during three nights at home. We found that on average the estimates of the decay rate and the initial sleep need have higher values when automatic NREM detection was used as compared to manual NREM annotation. However, the average variability of these estimates across multiple nights of the same subject was lower when the automatic NREM detection classifier was used. While this method slightly over estimates the sleep need parameters, the reduced variability across subjects makes it more effective for within subject statistical comparisons of a given sleep intervention.

Substance Use among Male Sex Workers in Vietnam: Prevalence, Onset, and Interactions with Sexual Risk

PubMed Central

Yu, Gary; Clatts, Michael C.; Goldsamt, Lloyd A.; Giang, Le Minh

2014-01-01

Background HIV research in Vietnam has focused primarily on its large heroin injector population. Data on men who have sex with men [MSM], particularly the large and growing population of men who exchange sex for money or other material rewards, male sex workers [MSWs], is very limited. Methods Data derive from a cross-sectional study of MSW, age 16-35, recruited using community sampling methods in three cities in 2010-2011, including Hanoi, Ho Chi Minh City [HCMC], and Nha Trang City (n=710). Assessments included demographic characteristics, substance use, sexual risk, and use of health services. A series of “event” questions were used to assess the influence of alcohol and drugs on sexual risk. Results Both tobacco and alcohol are initiated at a young age and most participants currently use both substances overall across all three cities. While alcohol and tobacco use precede the initiation of sex work, stimulant and opiate use are initiated following the initiation of sex work. There was substantial overlap between substance use and sexual risk, and this overlap was strongest in sexual events involving male and female elective partners rather than sex work clients. Conclusion Although rates of HIV infection in this group are low, this may be an artifact of the young age of the sample. High rates of drug use, including alcohol, tobacco and illicit drugs, coupled with high rates of ulcerative STIs such as HPV, suggest the potential for rapid amplification of STI/HIV risk among MSW and their complex sex partnering networks. PMID:25488636

Development and Optimization of HPLC Analysis of Metronidazole, Diloxanide, Spiramycin and Cliquinol in Pharmaceutical Dosage Forms Using Experimental Design.

PubMed

Elkhoudary, Mahmoud M; Abdel Salam, Randa A; Hadad, Ghada M

2016-11-01

A new simple, sensitive, rapid and accurate gradient reversed-phase high-performance liquid chromatography with photodiode array detector (RP-HPLC-DAD) was developed and validated for simultaneous analysis of Metronidazole (MNZ), Spiramycin (SPY), Diloxanidefuroate (DIX) and Cliquinol (CLQ) using statistical experimental design. Initially, a resolution V fractional factorial design was used in order to screen five independent factors: the column temperature (°C), pH, phosphate buffer concentration (mM), flow rate (ml/min) and the initial fraction of mobile phase B (%). pH, flow rate and initial fraction of mobile phase B were identified as significant, using analysis of variance. The optimum conditions of separation determined with the aid of central composite design were: (1) initial mobile phase concentration: phosphate buffer/methanol (50/50, v/v), (2) phosphate buffer concentration (50 mM), (3) pH (4.72), (4) column temperature 30°C and (5) mobile phase flow rate (0.8 ml min -1 ). Excellent linearity was observed for all of the standard calibration curves, and the correlation coefficients were above 0.9999. Limits of detection for all of the analyzed compounds ranged between 0.02 and 0.11 μg ml -1 ; limits of quantitation ranged between 0.06 and 0.33 μg ml -1 The proposed method showed good prediction ability. The optimized method was validated according to ICH guidelines. Three commercially available tablets were analyzed showing good % recovery and %RSD. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ozone-initiated disinfection kinetics of Escherichia coli in water.

PubMed

Zuma, Favourite; Lin, Johnson; Jonnalagadda, Sreekanth B

2009-01-01

The effect of ozonation on the rate of disinfection of Escherichia coli was investigated as a function of ozone concentration, ozonation duration and flow rates. Ozone was generated in situ using Corona discharge method using compressed oxygen stream and depending on the oxygen flux the ozone concentrations ranged from 0.91-4.72 mg/L. The rate of disinfection of all the three microbes followed pseudo-first-order kinetics with respect to the microbe count and first order with respect to ozone concentration. The influence of pH and temperature the aqueous systems on the rate of ozone initiated disinfection of the microbe was investigated. The inactivation was faster at lower pH than at basic pH. Molecular ozone is found more effective in disinfection than hydroxyl radicals. Two reported mechanisms for antimicrobial activity of ozone in water systems from the literature are discussed. Based on the experimental findings a probable rate law and mechanism are proposed. Ozonation of natural waters significantly decreased the BOD levels of the control and microbe contaminated waters.

3D Simulation of Multiple Simultaneous Hydraulic Fractures with Different Initial Lengths in Rock

NASA Astrophysics Data System (ADS)

Tang, X.; Rayudu, N. M.; Singh, G.

2017-12-01

Hydraulic fracturing is widely used technique for extracting shale gas. During this process, fractures with various initial lengths are induced in rock mass with hydraulic pressure. Understanding the mechanism of propagation and interaction between these induced hydraulic cracks is critical for optimizing the fracking process. In this work, numerical results are presented for investigating the effect of in-situ parameters and fluid properties on growth and interaction of multi simultaneous hydraulic fractures. A fully coupled 3D fracture simulator, TOUGH- GFEM is used for simulating the effect of different vital parameters, including in-situ stress, initial fracture length, fracture spacing, fluid viscosity and flow rate on induced hydraulic fractures growth. This TOUGH-GFEM simulator is based on 3D finite volume method (FVM) and partition of unity element method (PUM). Displacement correlation method (DCM) is used for calculating multi - mode (Mode I, II, III) stress intensity factors. Maximum principal stress criteria is used for crack propagation. Key words: hydraulic fracturing, TOUGH, partition of unity element method , displacement correlation method, 3D fracturing simulator

A quasi-Newton algorithm for large-scale nonlinear equations.

PubMed

Huang, Linghua

2017-01-01

In this paper, the algorithm for large-scale nonlinear equations is designed by the following steps: (i) a conjugate gradient (CG) algorithm is designed as a sub-algorithm to obtain the initial points of the main algorithm, where the sub-algorithm's initial point does not have any restrictions; (ii) a quasi-Newton algorithm with the initial points given by sub-algorithm is defined as main algorithm, where a new nonmonotone line search technique is presented to get the step length [Formula: see text]. The given nonmonotone line search technique can avoid computing the Jacobian matrix. The global convergence and the [Formula: see text]-order convergent rate of the main algorithm are established under suitable conditions. Numerical results show that the proposed method is competitive with a similar method for large-scale problems.

Modeling of ultrasonic degradation of non-volatile organic compounds by Langmuir-type kinetics.

PubMed

Chiha, Mahdi; Merouani, Slimane; Hamdaoui, Oualid; Baup, Stéphane; Gondrexon, Nicolas; Pétrier, Christian

2010-06-01

Sonochemical degradation of phenol (Ph), 4-isopropylphenol (4-IPP) and Rhodamine B (RhB) in aqueous solutions was investigated for a large range of initial concentrations in order to analyze the reaction kinetics. The initial rates of substrate degradation and H(2)O(2) formation as a function of initial concentrations were determined. The obtained results show that the degradation rate increases with increasing initial substrate concentration up to a plateau and that the sonolytic destruction occurs mainly through reactions with hydroxyl radicals in the interfacial region of cavitation bubbles. The rate of H(2)O(2) formation decreases with increasing substrate concentration and reaches a minimum, followed by almost constant production rate for higher substrate concentrations. Sonolytic degradation data were analyzed by the models of Okitsu et al. [K. Okitsu, K. Iwasaki, Y. Yobiko, H. Bandow, R. Nishimura, Y. Maeda, Sonochemical degradation of azo dyes in aqueous solution: a new heterogeneous kinetics model taking into account the local concentration OH radicals and azo dyes, Ultrason. Sonochem. 12 (2005) 255-262.] and Seprone et al. [N. Serpone, R. Terzian, H. Hidaka, E. Pelizzetti, Ultrasonic induced dehalogenation and oxidation of 2-, 3-, and 4-chlorophenol in air-equilibrated aqueous media. Similarities with irradiated semiconductor particulates, J. Phys. Chem. 98 (1994) 2634-2640.] developed on the basis of a Langmuir-type mechanism. The five linearized forms of the Okitsu et al.'s equation as well as the non-linear curve fitting analysis method were discussed. Results show that it is not appropriate to use the coefficient of determination of the linear regression method for comparing the best-fitting. Among the five linear expressions of the Okitsu et al.'s kinetic model, form-2 expression very well represent the degradation data for Ph and 4-IPP. Non-linear curve fitting analysis method was found to be the more appropriate method to determine the model parameters. An excellent representation of the experimental results of sonolytic destruction of RhB was obtained using the Serpone et al.'s model. The Serpone et al.'s model gives a worse fit for the sonolytic degradation data of Ph and 4-IPP. These results indicate that Ph and 4-IPP undergo degradation predominantly at the bubble/solution interface, whereas RhB undergoes degradation at both bubble/solution interface and in the bulk solution. (c) 2010 Elsevier B.V. All rights reserved.

Time-dependent importance sampling in semiclassical initial value representation calculations for time correlation functions. II. A simplified implementation.

PubMed

Tao, Guohua; Miller, William H

2012-09-28

An efficient time-dependent (TD) Monte Carlo (MC) importance sampling method has recently been developed [G. Tao and W. H. Miller, J. Chem. Phys. 135, 024104 (2011)] for the evaluation of time correlation functions using the semiclassical (SC) initial value representation (IVR) methodology. In this TD-SC-IVR method, the MC sampling uses information from both time-evolved phase points as well as their initial values, and only the "important" trajectories are sampled frequently. Even though the TD-SC-IVR was shown in some benchmark examples to be much more efficient than the traditional time-independent sampling method (which uses only initial conditions), the calculation of the SC prefactor-which is computationally expensive, especially for large systems-is still required for accepted trajectories. In the present work, we present an approximate implementation of the TD-SC-IVR method that is completely prefactor-free; it gives the time correlation function as a classical-like magnitude function multiplied by a phase function. Application of this approach to flux-flux correlation functions (which yield reaction rate constants) for the benchmark H + H(2) system shows very good agreement with exact quantum results. Limitations of the approximate approach are also discussed.

Effect of moisture content on fed batch composting reactor of vegetable and fruit wastes.

PubMed

Jolanun, B; Tripetchkul, S; Chiemchaisri, C; Chaiprasert, P; Towprayoon, S

2005-03-01

Vegetable and fruit wastes mixed with sawdust were composted in a laboratory scale reactor by controlling the waste feeding rate at 21 kg m(-3) day(-1) and aeration rate at 10.6 l m(-3) min(-1). The effects of initial moisture content on organic matter degradation and process performance of fed batch composting were investigated. The absolute amount of removal, removal percentage, and removal rate of dry mass obtained were substantially different among the initial moisture contents. The rapid rise of moisture content and the lowest absolute amount of removal observed were achieved in the 50% condition. The initial moisture content yielding the largest absolute amount of removal in both feeding and curing stage was 30% whereas the removal percentage and rate constant of waste decomposition were highest in the 50% condition. Examined by traditional soil physics method, the moisture content at 50-55% was suitable for satisfying the degree of free air space (65-70%) of compost during the fed batch composting. Most degradable organic matter was mainly consumed in the feeding stage as indicated by a higher removal rate of dry mass in all cases. It is recommended that the initial moisture content of 30% and mode of aeration and agitation should be adopted for achieving practical fed batch composting of vegetable and fruit wastes. The study also demonstrated that the composting kinetics of vegetable and fruit wastes mixed with sawdust can be described by a first order model.

Calculating erosion rates of river bank sediment by combining field measurements of erodibility parameters and small-scale topographic features – A case study at the Danube River

USDA-ARS?s Scientific Manuscript database

This paper examines the application of a method for calculating fluvial erosion on river banks. In the investigated area the determination of potential erosion rates are essential to estimating the initiated river widening processes and their effect on navigation. A mini-jet device was employed, for...

Interaction of Repetitively Pulsed High Energy Laser Radiation With Matter

NASA Astrophysics Data System (ADS)

Hugenschmidt, Manfred

1986-10-01

The paper is concerned with laser target interaction processes involving new methods of improving the overall energy balance. As expected theoretically, this can be achieved with high repetition rate pulsed lasers even for initially highly reflecting materials, such as metals. Experiments were performed by using a pulsed CO2 laser at mean powers up to 2 kW and repetition rates up to 100 Hz. The rates of temperature rise of aluminium for example were thereby increased by lore than a factor of 3 as compared to cw-radiation of comparable power density. Similar improvements were found for the overall absorptivities that were increased by this method by more than an order of magnitude.

Sterilization failures in Singapore: an examination of ligation techniques and failure rates.

PubMed

Cheng, M C; Wong, Y M; Rochat, R W; Ratnam, S S

1977-04-01

The University Department of Obstetrics and Gynecology, Kandang Kerbau Hospital in Singapore, initiated a study in early 1974 of failure rates for various methods of sterilization and the factors responsible for the failures. During the period January 1974 to March 1976, 51 cases of first pregnancy following ligation were discovered. Cumulative failure rates at 24 months were 0.34 per 100 women for abdominal sterilization, 1.67 for culdoscopic, 3.12 for vaginal, and 4.49 for laparoscopic procedures. Findings for 35 patients who underwent religation showed that recanalization and the establishment of a fistulous opening caused the majority of failures. Clearly, more effective methods of tubal occlusion in sterilization are needed.

Forming first impressions of children: the role of attention-deficit/hyperactivity disorder symptoms and emotion dysregulation.

PubMed

Lee, Christine A; Milich, Richard; Lorch, Elizabeth P; Flory, Kate; Owens, Julie Sarno; Lamont, Andrea E; Evans, Steven W

2018-05-01

Previous research on peer status of children with attention-deficit/hyperactivity disorder (ADHD) has focused on already-established peer groups, rendering the specific social behaviors that influence peers' initial impressions largely unknown. Recently, theorists have argued that emotion dysregulation is a key aspect of ADHD, with empirical work finding relations between emotion dysregulation and social outcomes. Therefore, the current study focuses on the initial interactions among children varying in ADHD symptoms duringh a novel playgroup, proposing that emotion dysregulation displayed during the playgroup may serve as a possible pathway between ADHD symptoms and peers' initial negative impressions. Participants were 233 elementary-age children ranging from 8 to 10 years old (M = 8.83, 70% male). Parents and teachers rated children's ADHD symptoms and related impairment; 51% of the children met criteria for an ADHD diagnosis. Then, children participated with unfamiliar peers in a three-hour playgroup that included three structured and two unstructured tasks. After the tasks, children and staff rated each child on social outcomes. Coders unaware of child's diagnostic status watched videos of the groups and rated each child's global emotion dysregulation during each task. Using multiple raters and methods, ADHD severity was associated with more negative peer ratings, through observed emotion dysregulation. Results were consistent for both parent and teacher ratings of ADHD severity as well as for both peer ratings of likeability and staff ratings of perceived peer likeability. When focusing on improving peers' initial impressions of children with ADHD symptoms, emotion dysregulation may be a valuable target for intervention. © 2017 Association for Child and Adolescent Mental Health.

Increased work in cardiac trabeculae causes decreased mitochondrial NADH fluorescence followed by slow recovery.

PubMed Central

Brandes, R; Bers, D M

1996-01-01

The oxidative phosphorylation rate in isolated mitochondria is stimulated by increased [ADP], resulting in decreased [NADH]. In intact hearts, however, increased mechanical work has generally not been shown to cause an increase in [ADP]. Therefore, increased [NADH] has been suggested as an alternative for stimulating the phosphorylation rate. Such a rise in [NADH] could result from stimulation of various substrate dehydrogenases by increased intracellular [Ca2+] (e.g., during increased pacing frequency). We have monitored mitochondrial [NADH] in isolated rat ventricular trabeculae, using a novel fluorescence spectroscopy method where a native fluorescence signal was used to correct for motion artifacts. Work was controlled by increased pacing frequency and assessed using time-averaged force. At low-pacing rates (approximately 0.1 Hz), [NADH] immediately decreased during contraction and then slowly recovered (approximately 5 s) before the next contraction. At higher rates, [NADH] initially decreased by an amount related to pacing rate (i.e., work). However, during prolonged stimulation, [NADH] slowly (approximately 60 s) recovered to a new steady-state level below the initial level. We conclude that 1) during increased work, oxidative phosphorylation is not initially stimulated by increased mitochondrial [NADH]; and 2) increased pacing frequency slowly causes stimulation of NADH production. Images FIGURE 2 FIGURE 4 PMID:8842239

Treatment of febrile geriatric patients with suspected urinary tract infections in a hospital with high rates of ESBL producing bacteria: a cohort study

PubMed Central

Shimoni, Zvi; Cohen, Regev; Avdiaev, Ruslan; Froom, Paul

2016-01-01

Purpose To determine the consequences of treating febrile geriatric patients with a suspected urinary tract infection (UTI) with antibiotics that have high resistance rates due primarily to extended-spectrum β-lactamase (ESBL) producing bacteria. Methods In this cohort study, we selected 257 consecutive hospitalised patients aged ≥70 years with a chief symptom of fever, possibly due to a UTI and initially treated with antibiotics with rates in our hospital of urinary culture resistance >20%. Patients with severe sepsis were excluded. The main outcomes measures were in vitro bacterial resistance to initial antibiotic therapy (BRIAT), response to therapy, hospitalisation days and mortality. Results Urine cultures were positive in 64.2% (165 of 257) of the patients and BRIAT occurred in 28.0% (72 of 257). Response rates were 100% (93 of 93) in those with bacteria sensitive to initial antibiotic therapy, 95.7% (88 of 92) in the culture negative patients, and 66.7% (48 of 72) in those with BRIAT (p<0.001). There were no deaths due to deterioration during the initial treatment period because of BRIAT. In the patients with BRIAT, the median length of hospitalisation was 3 days longer than that in the other patients (7 and 4 days, respectively, p<0.001). Conclusions We conclude that initial broad spectrum antibiotic treatment could potentially lower the median length of hospitalisation by 3 days in many hospitalised geriatric patients without an extra-urinary tract source for their fever. This benefit needs to be balanced against the risk to the individual patient and to the general public of increasing bacterial resistance rates to broader spectrum antibiotics often held in reserve. PMID:27986743

Applying constraints on model-based methods: Estimation of rate constants in a second order consecutive reaction

NASA Astrophysics Data System (ADS)

Kompany-Zareh, Mohsen; Khoshkam, Maryam

2013-02-01

This paper describes estimation of reaction rate constants and pure ultraviolet/visible (UV-vis) spectra of the component involved in a second order consecutive reaction between Ortho-Amino benzoeic acid (o-ABA) and Diazoniom ions (DIAZO), with one intermediate. In the described system, o-ABA was not absorbing in the visible region of interest and thus, closure rank deficiency problem did not exist. Concentration profiles were determined by solving differential equations of the corresponding kinetic model. In that sense, three types of model-based procedures were applied to estimate the rate constants of the kinetic system, according to Levenberg/Marquardt (NGL/M) algorithm. Original data-based, Score-based and concentration-based objective functions were included in these nonlinear fitting procedures. Results showed that when there is error in initial concentrations, accuracy of estimated rate constants strongly depends on the type of applied objective function in fitting procedure. Moreover, flexibility in application of different constraints and optimization of the initial concentrations estimation during the fitting procedure were investigated. Results showed a considerable decrease in ambiguity of obtained parameters by applying appropriate constraints and adjustable initial concentrations of reagents.

Tracing children's vocabulary development from preschool through the school-age years: An 8-year longitudinal study

PubMed Central

Kang, Cuiping; Liu, Hongyun; Zhang, Yuping; McBride-Chang, Catherine; Tardif, Twila; Li, Hong; Liang, Weilan; Zhang, Zhixiang; Shu, Hua

2014-01-01

In this 8-year longitudinal study, we traced the vocabulary growth of Chinese children, explored potential precursors of vocabulary knowledge, and investigated how vocabulary growth predicted future reading skills. Two hundred sixty-four (264) native Chinese children from Beijing were measured on a variety of reading and language tasks over 8 years. Between the ages of 4 to 10 years, they were administered tasks of vocabulary and related cognitive skills. At age 11, comprehensive reading skills, including character recognition, reading fluency, and reading comprehension were examined. Individual differences in vocabulary developmental profiles were estimated using the intercept-slope cluster method. Vocabulary development was then examined in relation to later reading outcomes. Three subgroups of lexical growth were classified, namely high-high (with a large initial vocabulary size and a fast growth rate), low-high (with a small initial vocabulary size and a fast growth rate) and low-low (with a small initial vocabulary size and a slow growth rate) groups. Low-high and low-low groups were distinguishable mostly through phonological skills, morphological skills and other reading-related cognitive skills. Childhood vocabulary development (using intercept and slope) explained subsequent reading skills. Findings suggest that language-related and reading-related cognitive skills differ among groups with different developmental trajectories of vocabulary, and the initial size and growth rate of vocabulary may be two predictors for later reading development. PMID:24962559

Parent-rated externalizing behavior in preschoolers: the predictive utility of structured interviews, teacher reports, and classroom observations.

PubMed

Doctoroff, Greta L; Arnold, David H

2004-12-01

This study investigated multiple forms of home and school assessment as predictors of parent-rated behavior problems across a preschool year. Participants were a community sample of 79 preschool children, their parents, and their teachers. Parent ratings of behavior problems were obtained toward the beginning of the school year and approximately 6 months later. Behavior problems were also assessed early in the school year using parent structured interviews, teacher-rating scales, and classroom observations of problem and prosocial behavior. Consistent with hypotheses, each assessment method significantly predicted year-end parent ratings of behavior problems, even above initial ratings.

Ecological content validation of the Information Assessment Method for parents (IAM-parent): A mixed methods study.

PubMed

Bujold, M; El Sherif, R; Bush, P L; Johnson-Lafleur, J; Doray, G; Pluye, P

2018-02-01

This mixed methods study content validated the Information Assessment Method for parents (IAM-parent) that allows users to systematically rate and comment on online parenting information. Quantitative data and results: 22,407 IAM ratings were collected; of the initial 32 items, descriptive statistics showed that 10 had low relevance. Qualitative data and results: IAM-based comments were collected, and 20 IAM users were interviewed (maximum variation sample); the qualitative data analysis assessed the representativeness of IAM items, and identified items with problematic wording. Researchers, the program director, and Web editors integrated quantitative and qualitative results, which led to a shorter and clearer IAM-parent. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Direct Method for Continuous Determination of Iron Oxidation by Autotrophic Bacteria

PubMed Central

Steiner, Michael; Lazaroff, Norman

1974-01-01

A method for direct, continuous determination of ferric ions produced in autotrophic iron oxidation, which depends upon the measurement of ferric ion absorbance at 304 nm, is described. The use of initial rates is shown to compensate for such changes in extinction during oxidation, which are due to dependence of the extinction coefficient on the ratio of complexing anions to ferric ions. A graphical method and a computer method are given for determination of absolute ferric ion concentration, at any time interval, in reaction mixtures containing Thiobacillus ferrooxidans and ferrous ions at known levels of SO42+ and hydrogen ion concentrations. Some examples are discussed of the applicability of these methods to study of the rates of ferrous ion oxidation related to sulfate concentration. PMID:4441066

Electron beam switched discharge for rapidly pulsed lasers

DOEpatents

Pleasance, Lyn D.; Murray, John R.; Goldhar, Julius; Bradley, Laird P.

1981-01-01

Method and apparatus for electrical excitation of a laser gas by application of a pulsed voltage across the gas, followed by passage of a pulsed, high energy electron beam through the gas to initiate a discharge suitable for laser excitation. This method improves upon current power conditioning techniques and is especially useful for driving rare gas halide lasers at high repetition rates.

Kinetics and Mechanism of Iodide Oxidation by Iron(III): A Clock Reaction Approach

ERIC Educational Resources Information Center

Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

2008-01-01

A simple method for studying the kinetics of a chemical reaction is described and the significance of reaction orders in deducing reaction mechanisms is demonstrated. In this student laboratory experiment, oxidation of iodide by iron(III) ions in an acidic medium is transformed into a clock reaction. By means of the initial rates method, it is…

Northwest Manufacturing Initiative

DTIC Science & Technology

2013-03-26

Testing of Metallic Materials] specifications. For high temperature tests, a heated water bath was use while for low temperature testing down to...Weld metal and heat affected zones were evaluated using Charpy and E399 fracture toughness methods. The influence of temperature , loading rate, CVN...determine the influence of fracture test methods and welding procedures on toughness. Room temperature E399 tests, (CTS) were carried out under

Molten salt-directed synthesis method for LiMn2O4 nanorods as a cathode material for a lithium-ion battery with superior cyclability

NASA Astrophysics Data System (ADS)

Kebede, Mesfin A.; Ozoemena, Kenneth I.

2017-02-01

A molten salt synthesis technique has been used to prepare nanorods of Mn2O3 and single-crystal LiMn2O4 nanorods cathode material with superior capacity retention. The molten salt-directed synthesis involved the use of NaCl as the eutectic melt. The as-synthesized LiMn2O4 nanorods cathode material showed superior electrochemical performance compared to the LiMn2O4 sample obtained via the solid state method. The as-synthesized LiMn2O4 nanorods maintained more than 95% of the initial discharge capacity of 107 mA h g-1 over 100 cycles at a rate of 0.1 C, whereas the LiMn2O4 sample synthesized using the solid state reaction method maintained 88% of the initial discharge capacity of 98 mA h g-1 over 100 cycles at a rate of 0.1 C. Compared to the literature, the molten salt-directed method for the preparation of high-performance LiMn2O4 is simpler and less expensive, with greater potential for industrial scale-up.

Cytomegalovirus retinitis in patients with AIDS after initiating antiretroviral therapy

PubMed Central

Jabs, Douglas A.; Van Natta, Mark L.; Holland, Gary N.; Danis, Ronald

2016-01-01

Purpose To evaluate the rates of new-onset cytomegalovirus (CMV) retinitis and worsening existing CMV retinitis in patients with AIDS after initiating combination antiretroviral therapy (cART) and the role of an immune recovery inflammatory syndrome (IRIS). Design Cohort study Methods Immune recovery was defined as an increase in CD4+ T cells to ≥100 cells/μL; rates of new-onset CMV retinitis and of worsening of CMV retinitis (either increasing border activity or retinitis progression) were compared between those with and without immune recovery. Results Among patients without CMV retinitis, 1 of 75 patients with immune recovery developed CMV retinitis in the first 6 months after initiating cART vs. 1 of 31 without immune recovery (P=0.14). Among patients with CMV retinitis, the rates of retinitis progression and increasing retinitis border activity among patients during the first 6 months after initiating cART in those with immune recovery were 0.11/PY (95% confidence interval [CI] 0, 0.62) and 0.11/PY (95% CI 0, 0.62), respectively, vs. 0.67/PY (95% CI 0.22, 1.56) and 0.40/PY (95% CI 0.08, 1.17), respectively, for those without immune recovery (P=0.11 and 0.47). Conclusions Among persons with AIDS who experience immune recovery, there was neither an increased rate of new-onset CMV retinitis nor worsening of existing CMV retinitis in the first 6 months after initiating cART vs. those without immune recovery. These data are consistent with the known 3–6 month lag in recovery of specific immunity to CMV after initiating cART and suggest that “immune recovery retinitis”, a proposed IRIS phenomenon, is rare. PMID:27984023

Rates of Initial Virological Suppression and Subsequent Virological Failure After Initiating Highly Active Antiretroviral Therapy: The Impact of Aboriginal Ethnicity and Injection Drug Use

PubMed Central

Martin, L.J.; Houston, S.; Yasui, Y.; Wild, T.C.; Saunders, L.D.

2010-01-01

Objectives: To compare rates of initial virological suppression and subsequent virological failure by Aboriginal ethnicity after starting highly active antiretroviral therapy (HAART). Methods: We conducted a retrospective cohort study of antiretroviral-naïve HIV-patients starting HAART in January 1999-June 2005 (baseline), followed until December 31, 2005 in Alberta, Canada. We compared the odds of achieving initial virological suppression (viral load <500 copies/mL) by Aboriginal ethnicity using logistic regression and, among those achieving suppression, rates of virological failure (the first of two consecutive viral loads > 1000 copies/mL) by Aboriginal ethnicity using cumulative incidence curves and Cox proportional hazards models. Sex, injection drug use as an HIV exposure category (IDU), baseline age, CD4 cell count, viral load, calendar year, and HAART regimen were considered as potential confounders. Results: Of 461 study patients, 37% were Aboriginal and 48% were IDUs; 71% achieved initial virological suppression and were followed for 730.4 person-years. After adjusting for confounding variables, compared to non-Aboriginals with other exposures, the odds of achieving initial virological suppression were lower for Aboriginal IDUs (odds ratio (OR)=0.33, 95% CI=0.19-0.60, p=0.0002), non-Aboriginal IDUs (OR=0.30, 95% CI=0.15-0.60, p=0.0006), and Aboriginals with other exposures (OR=0.38, 95% CI=0.21-0.67, p=0.0009). Among those achieving suppression, Aboriginals experienced higher virological failure rates ≥1 year after suppression (hazard ratio=3.35, 95% CI=1.68-6.65, p=0.0006). Conclusions: Future research should investigate adherence among Aboriginals and IDUs treated with HAART and explore their treatment experiences to assess ways to improve outcomes. PMID:21187007

Parental R-Rated Movie Restriction and Early-Onset Alcohol Use*

PubMed Central

Tanski, Susanne E.; Dal Cin, Sonya; Stoolmiller, Mike; Sargent, James D.

2010-01-01

Objective: The aim of this study was to determine if parental restriction regarding Restricted-rated movies (R movies) predicts lower rates of early-onset alcohol use. Method: Students from 15 northern New England middle schools were surveyed in 1999, and never-drinkers were resurveyed 13–26 months later to determine alcohol use. Drinking was determined by the question, “Have you ever had beer, wine, or other drink with alcohol that your parents didn't know about?” R-movie restriction was assessed by the question, “How often do your parents allow you to watch movies that are rated R?” Results: The sample included 2,406 baseline never-drinkers who were surveyed at follow-up, of whom 14.8% had initiated alcohol use. At baseline, 20% reported never being allowed to watch R movies, and 21% reported being allowed all the time. Adolescents allowed to watch R-rated movies had higher rates of alcohol initiation (2.9% initiation among never allowed, 12.5% once in a while, 18.8% sometimes, and 24.4% all the time). Controlling for sociodemographics, personality characteristics, and authoritative parenting style, the adjusted odds ratios for initiating alcohol use were 3.0 (95% CI [1.7, 5.1]) for those once in a while allowed, 3.3 [1.9, 5.6] for those sometimes allowed, and 3.5 [2.0, 6.0] for those always allowed to watch R-rated movies. Alcohol initiation was more likely if R-rated movie restriction relaxed over time; tightening of restriction had a protective effect (p < .001). A structural model was developed that modeled two latent parenting constructs: (a) authoritative parenting and (b) media parenting. Both constructs had direct inverse paths to trying alcohol and indirect paths through lower exposure to R-rated movies. Conclusions: After accounting for differences in authoritative parenting style, adolescents reporting lesser restrictions for R movies have higher odds of future alcohol use. The structural model suggests that media parenting operates independently from authoritative parenting and should be incorporated explicitly into parenting prevention programs. PMID:20409440

Titanium subhydride potassium perchlorate (TiH1.65/KClO4) burn rates from hybrid closed bomb-strand burner experiments.

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

Cooper, Marcia A.; Oliver, Michael S.

2012-08-01

A hybrid closed bomb-strand burner is used to measure the burning behavior of the titanium subhydride potassium perchlorate pyrotechnic with an equivalent hydrogen concentration of 1.65. This experimental facility allows for simultaneous measurement of the closed bomb pressure rise and pyrotechnic burn rate as detected by electrical break wires over a range of pressures. Strands were formed by pressing the pyrotechnic powders to bulk densities between 60% and 90% theoretical maximum density. The burn rate dependance on initial density and vessel pressure are measured. At all initial strand densities, the burn is observed to transition from conductive to convective burningmore » within the strand. The measured vessel pressure history is further analyzed following the closed bomb analysis methods developed for solid propellants.« less

Film Implementation of a Neutron Detector (FIND): Critical Materials Properties

DTIC Science & Technology

2007-09-01

In the implementation of the TRR method used initially,2 a pulsed titanium -sapphire laser with a repetition rate of 82 MHz and a pulse width of...for this fluorescence to appear. The carriers are excited by a very short (20 fs) laser pulse generated by a titanium -sapphire laser oscillator...were made using the following methods: • Lifetime: time-resolved (pump-probe) reflectivity method with dual fiber laser system • Mobility: free

76 FR 25328 - New Mexico Green Initiatives, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-04

... Mexico Green Initiatives, LLC's application for market-based rate authority, with an accompanying rate... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER11-3431-000] New Mexico Green Initiatives, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

Developmental dysplasia of the hip: impact of sonographic newborn hip screening on the outcome of early treated decentered hip joints-a single center retrospective comparative cohort study based on Graf's method of hip ultrasonography.

PubMed

Tschauner, Christian; Fürntrath, Frank; Saba, Yasaman; Berghold, Andrea; Radl, Roman

2011-12-01

PURPOSE/BACKGROUND/INTRODUCTION: The aim of this study was to retrospectively evaluate the impact of neonatal sonographic hip screening using Graf's method for the management and outcome of orthopaedic treatment of decentered hip joints with developmental dysplasia of the hip (DDH), using three decades (1978-2007) of clinical information compiled in a medical database. Three representative cohorts of consecutive cases of decentered hip joints were selected according to different search criteria and inclusion and exclusion parameters: (1) cohort 1 (1978-1982; n = 80), without sonographic screening; (2) cohort 2.1 (1994-1996; n = 91), with nationwide established general sonographic screening according to the Graf-method; (3) cohort 2.2 (2003-2005; n = 91), with sonographic screening including referred cases for open reduction from non-screened populations. These three cohorts were compared for the following parameters: age at initial treatment, successful closed reduction, necessary overhead traction, necessary adductor-tenotomy, rate of open reduction, rate of avascular necrosis (AVN) and rate of secondary acetabuloplasty. The age at initial treatment was reduced from 5.5 months in the first cohort to 2 months in the two subsequent two cohorts and the rate of successful closed reduction increased from 88.7 to 98.9 and 95.6%, respectively. There was a statistically significant improvement in six out of seven parameters with sonographic hip screening; only the rate of secondary acetabuloplasty did not improve significantly. Compared to the era before the institution of a sonographic hip screening programme according to the Graf-method in Austria in 1992, ultrasound screening based-treatment of decentered hip joints has become safer, shorter and simpler: "safer" means lower rate of AVN, "shorter" means less treatment time due to earlier onset and "simpler" means that the devices are now less invasive and highly standardized.

Nonparametric evaluation of birth cohort trends in disease rates.

PubMed

Tarone, R E; Chu, K C

2000-01-01

Although interpretation of age-period-cohort analyses is complicated by the non-identifiability of maximum likelihood estimates, changes in the slope of the birth-cohort effect curve are identifiable and have potential aetiologic significance. A nonparametric test for a change in the slope of the birth-cohort trend has been developed. The test is a generalisation of the sign test and is based on permutational distributions. A method for identifying interactions between age and calendar-period effects is also presented. The nonparametric method is shown to be powerful in detecting changes in the slope of the birth-cohort trend, although its power can be reduced considerably by calendar-period patterns of risk. The method identifies a previously unidentified decrease in the birth-cohort risk of lung-cancer mortality from 1912 to 1919, which appears to reflect a reduction in the initiation of smoking by young men at the beginning of the Great Depression (1930s). The method also detects an interaction between age and calendar period in leukemia mortality rates, reflecting the better response of children to chemotherapy. The proposed nonparametric method provides a data analytic approach, which is a useful adjunct to log-linear Poisson analysis of age-period-cohort models, either in the initial model building stage, or in the final interpretation stage.

Reconstruction of disease transmission rates: Applications to measles, dengue, and influenza.

PubMed

Lange, Alexander

2016-07-07

Transmission rates are key in understanding the spread of infectious diseases. Using the framework of compartmental models, we introduce a simple method to reconstruct time series of transmission rates directly from incidence or disease-related mortality data. The reconstruction employs differential equations, which model the time evolution of infective stages and strains. Being sensitive to initial values, the method produces asymptotically correct solutions. The computations are fast, with time complexity being quadratic. We apply the reconstruction to data of measles (England and Wales, 1948-1967), dengue (Thailand, 1982-1999), and influenza (U.S., 1910-1927). The Measles example offers comparison with earlier work. Here we re-investigate reporting corrections, include and exclude demographic information. The dengue example deals with the failure of vector-control measures in reducing dengue hemorrhagic fever (DHF) in Thailand. Two competing mechanisms have been held responsible: strain interaction and demographic transitions. Our reconstruction reveals that both explanations are possible, showing that the increase in DHF cases is consistent with decreasing transmission rates resulting from reduced vector counts. The flu example focuses on the 1918/1919 pandemic, examining the transmission rate evolution for an invading strain. Our analysis indicates that the pandemic strain could have circulated in the population for many months before the pandemic was initiated by an event of highly increased transmission. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Novel Method for Characterizing Fatigue Delamination Growth Under Mode I Using the Double Cantilever Beam Specimen

NASA Technical Reports Server (NTRS)

Carvalho, Nelson; Murri, G.

2014-01-01

A novel method is proposed to obtain Mode I delamination growth rate from a Double Cantilever Beam (DCB) specimen. In the proposed method, Unidirectional (UD) DCB specimens are tested in fatigue at different initial maximum energy release rates levels. The growth rate data obtained in the first increments of crack growth at each maximum energy release rate level are used to generate a Paris Law equation, which characterizes delamination growth rate without fiber-bridging, and can also be used to determine a delamination onset curve. The remaining delamination growth rate data from each test are used to determine a modified Paris law, which characterizes the delamination growth rate in a DCB specimen, explicitly accounting for fiber-bridging. The proposed expression captures well the scatter in experimental data obtained using the DCB specimens, suggesting its adequacy. The Paris Law characterizing delamination growth rate without fiber-bridging predicts higher delamination growth rates for the same maximum energy release rate applied, leading to a conservative estimate for delamination growth. This is particularly relevant, since in generic ply interfaces, fiber-bridging is less predominant than in UD DCB specimens. Failing to account for fiber-bridging in UD DCB specimens may underestimate the delamination growth rate, yielding non-conservative predictions.

Provider-Initiated Late Preterm Births in Brazil: Differences between Public and Private Health Services

PubMed Central

Leal, Maria do Carmo; Esteves-Pereira, Ana Paula; Nakamura-Pereira, Marcos; Torres, Jacqueline Alves; Domingues, Rosa Maria Soares Madeira; Dias, Marcos Augusto Bastos; Moreira, Maria Elizabeth; Theme-Filha, Mariza; da Gama, Silvana Granado Nogueira

2016-01-01

Background A large proportion of the rise in prematurity worldwide is owing to late preterm births, which may be due to the expansion of obstetric interventions, especially pre-labour caesarean section. Late preterm births pose similar risks to overall prematurity, making this trend a concern. In this study, we describe factors associated with provider-initiated late preterm birth and verify differences in provider-initiated late preterm birth rates between public and private health services according to obstetric risk. Methods This is a sub-analysis of a national population-based survey of postpartum women entitled “Birth in Brazil”, performed between 2011 and 2012. We included 23,472 singleton live births. We performed non-conditional multiple logistic regressions assessing associated factors and analysing differences between public and private health services. Results Provider-initiated births accounted for 38% of late preterm births; 32% in public health services and 61% in private health services. They were associated with previous preterm birth(s) and maternal pathologies for women receiving both public and private services and with maternal age ≥35 years for women receiving public services. Women receiving private health services had higher rates of provider-initiated late preterm birth (rate of 4.8%) when compared to the ones receiving public services (rate of 2.4%), regardless of obstetric risk–adjusted OR of 2.3 (CI 1.5–3.6) for women of low obstetric risk and adjusted OR of 1.6 (CI 1.1–2.3) for women of high obstetric risk. Conclusion The high rates of provider-initiated late preterm birth suggests a considerable potential for reduction, as such prematurity can be avoided, especially in women of low obstetric risk. To promote healthy births, we advise introducing policies with incentives for the adoption of new models of birth care. PMID:27196102

Reduction in the write error rate of voltage-induced dynamic magnetization switching using the reverse bias method

NASA Astrophysics Data System (ADS)

Ikeura, Takuro; Nozaki, Takayuki; Shiota, Yoichi; Yamamoto, Tatsuya; Imamura, Hiroshi; Kubota, Hitoshi; Fukushima, Akio; Suzuki, Yoshishige; Yuasa, Shinji

2018-04-01

Using macro-spin modeling, we studied the reduction in the write error rate (WER) of voltage-induced dynamic magnetization switching by enhancing the effective thermal stability of the free layer using a voltage-controlled magnetic anisotropy change. Marked reductions in WER can be achieved by introducing reverse bias voltage pulses both before and after the write pulse. This procedure suppresses the thermal fluctuations of magnetization in the initial and final states. The proposed reverse bias method can offer a new way of improving the writing stability of voltage-driven spintronic devices.

The Effect of Temperature and Ionic Strength on the Oxidation of Iodide by Iron(III): A Clock Reaction Kinetic Study

ERIC Educational Resources Information Center

Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

2012-01-01

A laboratory exercise has recently been reported in which the students use the initial rates method based on the clock reaction approach to deduce the rate law and propose a reaction mechanism for the oxidation of iodide by iron(III) ions. The same approach is used in the exercise proposed herein; the students determine the dependence of the…

Diabatic forcing and intialization with assimilation of cloud water and rainwater in a forecast model

NASA Technical Reports Server (NTRS)

Raymond, William H.; Olson, William S.; Callan, Geary

1995-01-01

In this study, diabatic forcing, and liquid water assimilation techniques are tested in a semi-implicit hydrostatic regional forecast model containing explicit representations of grid-scale cloud water and rainwater. Diabatic forcing, in conjunction with diabatic contributions in the initialization, is found to help the forecast retain the diabatic signal found in the liquid water or heating rate data, consequently reducing the spinup time associated with grid-scale precipitation processes. Both observational Special Sensor Microwave/Imager (SSM/I) and model-generated data are used. A physical retrieval method incorporating SSM/I radiance data is utilized to estimate the 3D distribution of precipitating storms. In the retrieval method the relationship between precipitation distributions and upwelling microwave radiances is parameterized, based upon cloud ensemble-radiative model simulations. Regression formulae relating vertically integrated liquid and ice-phase precipitation amounts to latent heating rates are also derived from the cloud ensemble simulations. Thus, retrieved SSM/I precipitation structures can be used in conjunction with the regression-formulas to infer the 3D distribution of latent heating rates. These heating rates are used directly in the forecast model to help initiate Tropical Storm Emily (21 September 1987). The 14-h forecast of Emily's development yields atmospheric precipitation water contents that compare favorably with coincident SSM/I estimates.

Rapid, efficient charging of lead-acid and nickel-zinc traction cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1978-01-01

Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

Automated startup of the MIT research reactor

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

Kwok, K.S.

1992-01-01

This summary describes the development, implementation, and testing of a generic method for performing automated startups of nuclear reactors described by space-independent kinetics under conditions of closed-loop digital control. The technique entails first obtaining a reliable estimate of the reactor's initial degree of subcriticality and then substituting that estimate into a model-based control law so as to permit a power increase from subcritical on a demanded trajectory. The estimation of subcriticality is accomplished by application of the perturbed reactivity method. The shutdown reactor is perturbed by the insertion of reactivity at a known rate. Observation of the resulting period permitsmore » determination of the initial degree of subcriticality. A major advantage to this method is that repeated estimates are obtained of the same quantity. Hence, statistical methods can be applied to improve the quality of the calculation.« less

Precise Hypocenter Determination around Palu Koro Fault: a Preliminary Results

NASA Astrophysics Data System (ADS)

Fawzy Ismullah, M. Muhammad; Nugraha, Andri Dian; Ramdhan, Mohamad; Wandono

2017-04-01

Sulawesi area is located in complex tectonic pattern. High seismicity activity in the middle of Sulawesi is related to Palu Koro fault (PKF). In this study, we determined precise hypocenter around PKF by applying double-difference method. We attempt to investigate of the seismicity rate, geometry of the fault and distribution of focus depth around PKF. We first re-pick P-and S-wave arrival time of the PKF events to determine the initial hypocenter location using Hypoellipse method through updated 1-D seismic velocity. Later on, we relocated the earthquake event using double-difference method. Our preliminary results show the distribution of relocated events are located around PKF and have smaller residual time than the initial location. We will enhance the hypocenter location through updating of arrival time by applying waveform cross correlation method as input for double-difference relocation.

Breastfeeding rates in Hong Kong: a comparison of the 1987 and 1997 birth cohorts.

PubMed

Leung, Gabriel M; Ho, Lai-Ming; Lam, Tai-Hing

2002-09-01

Low breastfeeding rates are an issue of international public health concern. Anecdotal reports suggest very low breastfeeding rates in Asia, but no population-based studies have been conducted in the region. To determine the secular trend in breastfeeding practice in an Asian postindustrialized metropolitan community, we examined data from two population-based birth cohorts of Hong Kong infants in 1987 and 1997. Annual population rates of breastfeeding initiation and duration were estimated from the birth cohorts, considering the change in breastfeeding rates over 10 years with correction for sociodemographic and birth characteristics. Factors associated with breastfeeding practice were identified using multivariate logistic regression modeling in a pooled analysis of individual data of both cohorts. Overall, 26.8 percent of mothers initiated breastfeeding in 1987, and the rate increased to 33.5 percent in 1997. The rate would have been 27.4 percent in 1987 if the distributions of method of delivery, birthweight, birth order, maternal age, education, and employment status had been the same as in 1997. Only 7.6 percent of infants remained on the breast for more than 1 month in 1987 compared with 20.4 percent a decade later. Similarly, the rate for breastfeeding more than 3 months increased from 3.9 to 10.3 percent. Total breastfeeding duration was significantly longer in 1997 than 10 years earlier. This is the first systematic report of secular variations of breastfeeding rates in Asia. Hong Kong should set higher but realistic goals for breastfeeding that emphasize both initiation and maintenance. Given the wide latitude for improvement in terms of readily modifiable risk factors, such as smoking and cesarean section, these new goals should focus on improving rates in these targeted groups where breastfeeding rates are lowest.

Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

NASA Technical Reports Server (NTRS)

Stefanski, Philip L.

2014-01-01

A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

[The quantitative recovery of microbes during testing of disinfectants for instruments].

PubMed

Höller, C; Gundermann, K O

1990-02-01

The efficacy of a disinfectant can only be determined exactly, when quantitative as well as qualitative tests are being performed. Aim of this study was to ascertain whether the earlier published method of a germ carrier test could be applied also to the testing of disinfectants for instruments. Rubber tubes of 1 cm length were used as germ carriers, Staph. aureus, Pseud. aerug., Proteus mir., E. coli and Cand. alb. as test organisms. The culture media were CASO-agar and -broth, latter containing 20% defibrinated sheep blood in some experiments. Two disinfectants on aldehyde-basis and one disinfectant on phenol-basis and on biguanide-basis, respectively, were used for the disinfectant tests. The rubber tubes were contaminated with bacterial suspension, dried upright on sterile filters and then put into 10 ml CASO-broth. After high speed vortexing of the germ carriers the bacterial count was determined. Following factors that were believed to probably having an influence on the recovery rate of bacteria were investigated: 1. the amount of fluid staying on the rubber tubes; 2. the drying time; 3. the vortexing time; 4. repeated vortexing; 5. variations of the initial concentration of bacteria on the rubber tubes; 6. addition of inactivating substances. ad 1. The mean amount of fluid staying on the tubes was 0.0056 g. ad 2. Drying times longer than 30 to 60 min resulted partly in considerably lower bacterial counts. ad. 3. and 4. Neither extension of vortexing time nor repeated vortexing of the same germ carrier could raise the recovery rate of bacteria. ad 5. Higher initial concentration of bacteria on the rubber tubes could not be achieved. The recovery rate of bacteria was reliable even when the initial bacterial concentration was low. ad 6. Addition of inactivating substances to the CASO-broth had no influence on the recovery rate of bacteria. The test method was checked by testing four disinfectants for instruments and proved itself a good and reliable quantitative method.

The ketogenic diet: initiation at goal calories versus gradual caloric advancement.

PubMed

Bansal, Seema; Cramp, Laura; Blalock, Dan; Zelleke, Tesfaye; Carpenter, Jessica; Kao, Amy

2014-01-01

Inpatient initiation of the ketogenic diet has historically involved fasting followed by gradual advancement of calories and/or diet ratio. Complications during this initiation period are common. We sought to determine if the initiation of the diet at goal calories would reduce these complications while maintaining efficacy. Sixty patients were admitted to a tertiary care hospital for elective initiation of the ketogenic diet between October 2007 and January 2013. All patients were placed on a ketogenic diet initiation pathway. In 2010, the pathway was modified from gradual caloric advancement to initiation at goal calories. We selected 30 consecutive patients before and after the change for comparison. Each child's record was reviewed for the occurrence of hypoglycemia, number of days to reach full ketosis (defined as 4 + urine ketones), acidosis requiring commencement of sodium citrate, length of admission, and long-term efficacy. Both methods of initiation had similar rates of dehydration, vomiting, lethargy, and irritability. More patients initiated at goal received sodium citrate (P = 0.005); however, mean daily values of carbon dioxide were not significantly different. Onset of ketosis was slightly delayed (P = 0.009) in patients initiated at goal, but length of stay was not affected (P > 0.1). Hypoglycemia was uncommon and rates were similar between the groups. Efficacy at 3 months was better in patients initiated at full calories (P < 0.05). Initiation of the ketogenic diet full calories is a reasonable alternative to the current standard practice of gradual advancement of calories and/or diet ratio. Copyright © 2014 Elsevier Inc. All rights reserved.

Getting a Valid Survey Response From 662 Plastic Surgeons in the 21st Century.

PubMed

Reinisch, John F; Yu, Daniel C; Li, Wai-Yee

2016-01-01

Web-based surveys save time and money. As electronic questionnaires have increased in popularity, telephone and mailed surveys have declined. With any survey, a response rate of 75% or greater is critical for the validity of any study. We wanted to determine which survey method achieved the highest response among academic plastic surgeons. All American Association of Plastic Surgeons members were surveyed regarding authorship issues. They were randomly assigned to receive the questionnaire through 1 of 4 methods: (A) emailed with a link to an online survey; (B) regular mail; (C) regular mail + $1 bill, and (D) regular mail + $5 bill. Two weeks after the initial mailing, the number of responses was collected, and nonresponders were contacted to remind them to participate. The study was closed after 10 weeks. Survey costs were calculated based on the actual cost of sending the initial survey, including stationary, printing, postage (groups B-D), labor, and cost of any financial incentives. Cost of reminders to nonresponders was calculated at $5 per reminder, giving a total survey cost. Of 662 surveys sent, 54 were returned because of incorrect address/email, retirement, or death. Four hundred seventeen of the remaining 608 surveys were returned and analyzed. The response rate was lowest in the online group and highest in those mailed with a monetary incentive. Despite the convenience and low initial cost of web-based surveys, this generated the lowest response. We obtained statistically significant response rates (79% and 84%) only by using postal mail with monetary incentives and reminders. The inclusion of a $1 bill represented the greatest value and cost-effective survey method, based on cost per response.

Rates of breastfeeding initiation among newborns.

PubMed

Maimburg, Rikke Damkjær

2017-06-01

Rates of breastfeeding initiation in hospitals with a tertiary neonatal intensive care unit are limited. A follow-up study with prospectively collected data in a Danish university hospital with approximately 5000 annual births was conducted. Between 1 February 2015 and 30 June 2015, 1939 newborns were enrolled in the study. Rates of frequencies for initiation of breastfeeding were calculated. High initiations rates for breastfeeding were found among term-born infants. Newborns of multiparous women had the highest initiation rate of 91.7% and newborns delivered by cesarean section had the lowest initiation rate of 73.3%. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemiluminescence as a condition monitoring method for thermal aging and lifetime prediction of an HTPB elastomer.

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

Gillen, Kenneth Todd; Minier, Leanna M. G.; Celina, Mathias C.

Chemiluminescence (CL) has been applied as a condition monitoring technique to assess aging related changes in a hydroxyl-terminated-polybutadiene based polyurethane elastomer. Initial thermal aging of this polymer was conducted between 110 and 50 C. Two CL methods were applied to examine the degradative changes that had occurred in these aged samples: isothermal 'wear-out' experiments under oxygen yielding initial CL intensity and 'wear-out' time data, and temperature ramp experiments under inert conditions as a measure of previously accumulated hydroperoxides or other reactive species. The sensitivities of these CL features to prior aging exposure of the polymer were evaluated on the basismore » of qualifying this method as a quick screening technique for quantification of degradation levels. Both the techniques yielded data representing the aging trends in this material via correlation with mechanical property changes. Initial CL rates from the isothermal experiments are the most sensitive and suitable approach for documenting material changes during the early part of thermal aging.« less

Could Early Antiretroviral Therapy Entail More Risks than Benefits in sub-Saharan African HIV-Infected Adults? A Model-Based Analysis

PubMed Central

Anglaret, Xavier; Scott, Callie A.; Walensky, Rochelle P.; Ouattara, Eric; Losina, Elena; Moh, Raoul; Becker, Jessica E.; Uhler, Lauren; Danel, Christine; Messou, Eugene; Eholié, Serge; Freedberg, Kenneth A.

2013-01-01

Background Initiation of antiretroviral therapy (ART) in all HIV-infected adults, regardless of count, is a proposed strategy for reducing HIV transmission. We investigated the conditions under which starting ART early could entail more risks than benefits for patients with high CD4 counts. Methods We used a simulation model to compare ART initiation upon entry to care (“immediate ART”) to initiation at CD4 ≤350 cells/μL (“WHO 2010 ART”) in African adults with CD4 counts >500 cells/μL. We varied inputs to determine the combination of parameters (population characteristics, conditions of care, treatment outcomes) that would result in higher 15-year mortality with immediate ART. Results Fifteen-year mortality was 56.7% for WHO 2010 and 51.8% for immediate ART. In one-way sensitivity analysis, lower 15-year mortality was consistently achieved with immediate ART unless the rate of fatal ART toxicity was >1.0/100PY, the rate of withdrawal from care was >1.2-fold higher or the rate of ART failure due to poor adherence was >4.3-fold higher on immediate ART. In multi-way sensitivity analysis, immediate ART led to higher mortality when moderate rates of fatal ART toxicity (0.25/100PY) were combined with rates of withdrawal from care >1.1-fold higher and rates of treatment failure >2.1-fold higher on immediate ART than on WHO 2010 ART. Conclusions In sub-Saharan Africa, ART initiation at entry into care would improve long-term survival of patients with high CD4 counts, unless it is associated with increased withdrawal from care and decreased adherence. In early ART trials, a focus on retention and adherence will be critical. PMID:22809695

Electron beam-switched discharge for rapidly pulsed lasers

DOEpatents

Pleasance, L.D.; Murray, J.R.; Goldhar, J.; Bradley, L.P.

1979-12-11

A method and apparatus are designed for electrical excitation of a laser gas by application of a pulsed voltage across the gas, followed by passage of a pulsed, high energy electron beam through the gas to initiate a discharge suitable for laser excitation. This method improves upon current power conditioning techniques and is especially useful for driving rare gas halide lasers at high repetition rates.

Nanomaterials for sodium-ion batteries

DOEpatents

Liu, Jun; Cao, Yuliang; Xiao, Lifen; Yang, Zhenguo; Wang, Wei; Choi, Daiwon; Nie, Zimin

2015-05-05

A crystalline nanowire and method of making a crystalline nanowire are disclosed. The method includes dissolving a first nitrate salt and a second nitrate salt in an acrylic acid aqueous solution. An initiator is added to the solution, which is then heated to form polyacrylatyes. The polyacrylates are dried and calcined. The nanowires show high reversible capacity, enhanced cycleability, and promising rate capability for a battery or capacitor.

40 CFR 63.7732 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... hexane); n = Number of exhaust streams sampled; and Qi = Volumetric flow rate of effluent gas from... organic compounds (TOC), using hexane as the calibration gas. (2) Determine the average VOHAP, TGNMO, or... the concentration of TGNMO or TOC in ppmv as hexane as measured by Method 25 or 25A in 40 CFR part 60...

40 CFR 63.7732 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... hexane); n = Number of exhaust streams sampled; and Qi = Volumetric flow rate of effluent gas from... organic compounds (TOC), using hexane as the calibration gas. (2) Determine the average VOHAP, TGNMO, or... the concentration of TGNMO or TOC in ppmv as hexane as measured by Method 25 or 25A in 40 CFR part 60...

40 CFR 63.7732 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... hexane); n = Number of exhaust streams sampled; and Qi = Volumetric flow rate of effluent gas from... organic compounds (TOC), using hexane as the calibration gas. (2) Determine the average VOHAP, TGNMO, or... the concentration of TGNMO or TOC in ppmv as hexane as measured by Method 25 or 25A in 40 CFR part 60...

40 CFR 63.7732 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... hexane); n = Number of exhaust streams sampled; and Qi = Volumetric flow rate of effluent gas from... organic compounds (TOC), using hexane as the calibration gas. (2) Determine the average VOHAP, TGNMO, or... the concentration of TGNMO or TOC in ppmv as hexane as measured by Method 25 or 25A in 40 CFR part 60...

40 CFR 63.7824 - What test methods and other procedures must I use to establish and demonstrate initial compliance...

Code of Federal Regulations, 2010 CFR

2010-07-01

... select sampling port locations and the number of traverse points. Sampling ports must be located at the... Method 25 (40 CFR part 60, appendix A), milligrams per dry standard cubic meters (mg/dscm) for each day... = Conversion factor (mg/lb); and K = Daily production rate of sinter, tons/hr. (4) Continue the sampling and...

40 CFR 63.7824 - What test methods and other procedures must I use to establish and demonstrate initial compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... select sampling port locations and the number of traverse points. Sampling ports must be located at the... Method 25 (40 CFR part 60, appendix A), milligrams per dry standard cubic meters (mg/dscm) for each day... = Conversion factor (mg/lb); and K = Daily production rate of sinter, tons/hr. (4) Continue the sampling and...

Effect of cryopreservation methods and precryopreservation storage on bottlenose dolphin (Tursiops truncatus) spermatozoa.

PubMed

Robeck, T R; O'Brien, J K

2004-05-01

Research was conducted to develop an effective method for cryopreserving bottlenose dolphin (Tursiops truncatus) semen processed immediately after collection or after 24-h liquid storage. In each of two experiments, four ejaculates were collected from three males. In experiment 1, three cryopreservation methods (CM1, CM2, and CM3), two straw sizes (0.25 and 0.5 ml), and three thawing rates (slow, medium, and fast) were evaluated. Evaluations were conducted at collection, prefreeze, and 0-, 3-, and 6-h postthaw. A sperm motility index (SMI; total motility [TM] x % progressive motility [PPM] x kinetic rating [KR, scale of 0-5]) was calculated and expressed as a percentage MI of the initial ejaculate. For all ejaculates, initial TM and PPM were greater than 85%, and KR was five. At 0-h postthaw, differences in SMI among cryopreservation methods and thaw rates were observed (P < 0.05), but no effect of straw size was observed. In experiment 2, ejaculates were divided into four aliquots for dilution (1:1) and storage at 4 degrees C with a skim milk- glucose or a N-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES)-TRIS egg yolk solution and at 21 degrees C with a Hepes-Tyrode balanced salt solution (containing bovine albumin and HEPES) (TALP) medium or no dilution. After 24 h, samples were frozen and thawed (CM3, 0.5-ml straws, fast thawing rate) at 20 x 10(6) spermatozoa ml(-1) (low concentration) or at 100 x 10(6) spermatozoa ml(-1) (standard concentration). The SMI at 0-h postthaw was higher for samples stored at 4 degrees C than for samples stored at 21 degrees C (P < 0.001), and at 6-h postthaw, the SMI was higher for samples frozen at the standard concentration than for samples frozen at the low concentration (P < 0.05). For both experiments, acrosome integrity was similar across treatments. In summary, a semen cryopreservation protocol applied to fresh or liquid-stored semen maintained high levels of initial ejaculate sperm characteristics.

Microwave-induced electrostatic etching: generation of highly reactive magnesium for application in Grignard reagent formation.

PubMed

van de Kruijs, Bastiaan H P; Dressen, Mark H C L; Meuldijk, Jan; Vekemans, Jef A J M; Hulshof, Lumbertus A

2010-04-07

A detailed study regarding the influence of microwave irradiation on the formation of a series of Grignard reagents in terms of rates and selectivities has revealed that these heterogeneous reactions may display a beneficial microwave effect. The interaction between microwaves and magnesium turnings generates violent electrostatic discharges. These discharges on magnesium lead to melting of the magnesium surface, thus generating highly active magnesium particles. As compared to conventional operation the microwave-induced discharges on the magnesium surface lead to considerably shorter initiation times for the insertion of magnesium in selected substrates (i.e. halothiophenes, halopyridines, octyl halides, and halobenzenes). Thermographic imaging and surface characterization by scanning electron microscopy showed that neither selective heating nor a "specific" microwave effect was causing the reduction in initiation times. This novel and straightforward initiation method eliminates the use of toxic and environmentally adverse initiators. Thus, this initiation method limits the formation of by-products. We clearly demonstrated that microwave irradiation enables fast Grignard reagent formation. Therefore, microwave technology is promising for process intensification of Grignard based coupling reactions.

Subunit III-depleted cytochrome c oxidase provides insight into the process of proton uptake by proteins

PubMed Central

Varanasi, Lakshman; Hosler, Jonathan P.

2011-01-01

We review studies of subunit III-depleted cytochrome c oxidase (CcO III (−)) that elucidate the structural basis of steady-state proton uptake from solvent into an internal proton transfer pathway. The removal of subunit III from R. sphaeroides CcO makes proton uptake into the D pathway a rate-determining step, such that measurements of the pH dependence of steady-state O2 consumption can be used to compare the rate and functional pKa of proton uptake by D pathways containing different initial proton acceptors. The removal of subunit III also promotes spontaneous suicide inactivation by CcO, greatly shortening its catalytic lifespan. Because the probability of suicide inactivation is controlled by the rate at which the D pathway delivers protons to the active site, measurements of catalytic lifespan provide a second method to compare the relative efficacy of proton uptake by engineered CcO III (−) forms. These simple experimental systems have been used to explore general questions of proton uptake by proteins, such as the functional value of an initial proton acceptor, whether an initial acceptor must be surface-exposed, which side chains will function as initial proton acceptors and whether multiple acceptors can speed proton uptake. PMID:22023935

The characteristics of electrical trees in the inner and outer layers of different voltage rating XLPE cable insulation

NASA Astrophysics Data System (ADS)

Xie, Ansheng; Li, Shengtao; Zheng, Xiaoquan; Chen, George

2009-06-01

The statistical initiation and propagation characteristics of electrical trees in cross-linked polyethylene (XLPE) cables with different voltage ratings from 66 to 500 kV were investigated under a constant test voltage of 50 Hz/7 kV (the 66 kV rating cable is from UK, the others from China). It was found that the characteristics of electrical trees in the inner region of 66 kV cable insulation differed considerably from those in the outer region under the same test conditions; however, no significant differences appeared in the 110 kV rating cable and above. The initiation time of electrical trees in both the inner and the outer regions of the 66 kV cable is much shorter than that in higher voltage rating cables; in addition the growth rate of electrical trees in the 66 kV cable is much larger than that in the higher voltage rating cables. By using x-ray diffraction, differential scanning calorimetry and thermogravimetry methods, it was revealed that besides the extrusion process, the molecular weight of base polymer material and its distribution are the prime factors deciding the crystallization state. The crystallization state and the impurity content are responsible for the resistance to electrical trees. Furthermore, it was proposed that big spherulites will cooperate with high impurity content in enhancing the initiation and growth processes of electrical trees via the 'synergetic effect'. Finally, dense and small spherulites, high crystallinity, high purity level of base polymer material and super-clean production processes are desirable for higher voltage rating cables.

A more direct measure of supernova rates in starburst galaxies

NASA Technical Reports Server (NTRS)

Van Buren, Dave; Greenhouse, Matthew A.

1994-01-01

We determine ages for young supernova remnants in the starburst galaxies M82 and NGC 253 by applying Chevalier's model for radio emission from supernova blast waves expanding into the ejecta of their precursor stars. Absolute ages are determined by calibrating the model with radio observations of Cas A. We derive supernova rates of 0.10 and 0.08/yr for M82 and NGC 253, respectively. Assuming L (sub FIR) to be proportional to the supernova rate, we find r(sub SN) approximately equal 2 x 10(exp -12) x L(sub FIR), solar yr(exp -1) for these archetypal starburst galaxies. This approach is unique in that the supernova rate is derived from direct observation of supernova remnants rather than from star formation rates and an assumed initial mass function (IMF). We suggest that the approach presented here can be used to derive star-formation rates that are more directly related to observable quantities than those derived by other methods. We find that the supernova rate, far infrared (FIR) luminosity, and dynamical mass of the M82 starburst place few constraints on the initial mass function (IMF) slope and mass limits.

Woodstove smoke and CO emissions: comparison of reference methods with the VIP sampler.

PubMed

Jaasma, D R; Champion, M C; Shelton, J W

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO2 concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six different woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.

Woodstove smoke and CO emissions: Comparison of reference methods with the VIP sampler

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

Jaasma, D.R.; Champion, M.C.; Shelton, J.W.

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO{sub 2} concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six differentmore » woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.« less

Initial Results of an MDO Method Evaluation Study

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia M.; Kodiyalam, Srinivas

1998-01-01

The NASA Langley MDO method evaluation study seeks to arrive at a set of guidelines for using promising MDO methods by accumulating and analyzing computational data for such methods. The data are collected by conducting a series of re- producible experiments. In the first phase of the study, three MDO methods were implemented in the SIGHT: framework and used to solve a set of ten relatively simple problems. In this paper, we comment on the general considerations for conducting method evaluation studies and report some initial results obtained to date. In particular, although the results are not conclusive because of the small initial test set, other formulations, optimality conditions, and sensitivity of solutions to various perturbations. Optimization algorithms are used to solve a particular MDO formulation. It is then appropriate to speak of local convergence rates and of global convergence properties of an optimization algorithm applied to a specific formulation. An analogous distinction exists in the field of partial differential equations. On the one hand, equations are analyzed in terms of regularity, well-posedness, and the existence and unique- ness of solutions. On the other, one considers numerous algorithms for solving differential equations. The area of MDO methods studies MDO formulations combined with optimization algorithms, although at times the distinction is blurred. It is important to

Research on the Treatment of Aluminum Alloy Chemical Milling Wastewater with Fenton Process

NASA Astrophysics Data System (ADS)

Zong-liang, Huang; Ru, Li; Peng, Luo; Jun-li, Gu

2018-03-01

The aluminum alloy chemical milling wastewater was treated by Fenton method. The effect of pH value, reaction time, rotational speed, H2O2 dosage, Fe2+ dosage and the molar ratio between H2O2 and Fe2+ on the COD removal rate of aluminum alloy chemical milling wastewater were investigated by single factor experiment and orthogonal experiment. The results showed that the optimum operating conditions for Fenton oxidation were as follows: the initial pH value was 3, the rotational speed was 250r/min, the molar ratio of H2O2 and Fe2+ was 8, the reaction time was 90 min. Under the optimum conditions, the removal rate of the wastewater’s COD is about 72.36%. In the reaction kinetics that aluminum alloy chemical milling wastewater was oxidized and degraded by Fenton method under the optimum conditions, the reaction sequence of the initial COD was 0.8204.

Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smooth particle hydrodynamics

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

Pan, Wenxiao; Daily, Michael D.; Baker, Nathan A.

2015-12-01

We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. The numerical method is first verified in simple systems and then applied to the calculation of ligand binding to an acetylcholinesterase monomer. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) boundary condition, is considered on the reactive boundaries. This new boundary condition treatment allows for the analysis of enzymes with "imperfect" reaction rates. Rates for inhibitor binding to mAChE are calculated atmore » various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.« less

Assessment of the point-source method for estimating dose rates to members of the public from exposure to patients with 131I thyroid treatment

DOE PAGES

Dewji, Shaheen Azim; Bellamy, Michael B.; Hertel, Nolan E.; ...

2015-09-01

The U.S. Nuclear Regulatory Commission (USNRC) initiated a contract with Oak Ridge National Laboratory (ORNL) to calculate radiation dose rates to members of the public that may result from exposure to patients recently administered iodine-131 ( 131I) as part of medical therapy. The main purpose was to compare dose rate estimates based on a point source and target with values derived from more realistic simulations that considered the time-dependent distribution of 131I in the patient and attenuation of emitted photons by the patient’s tissues. The external dose rate estimates were derived using Monte Carlo methods and two representations of themore » Phantom with Movable Arms and Legs, previously developed by ORNL and the USNRC, to model the patient and a nearby member of the public. Dose rates to tissues and effective dose rates were calculated for distances ranging from 10 to 300 cm between the phantoms and compared to estimates based on the point-source method, as well as to results of previous studies that estimated exposure from 131I patients. The point-source method overestimates dose rates to members of the public in very close proximity to an 131I patient but is a broadly accurate method of dose rate estimation at separation distances of 300 cm or more at times closer to administration.« less

Teen pregnancy prevention: current perspectives.

PubMed

Lavin, Claudia; Cox, Joanne E

2012-08-01

Teen pregnancy has been subject of public concern for many years. In the United States, despite nearly 2 decades of declining teen pregnancy and birth rates, the problem persists, with significant disparities present across racial groups and in state-specific rates. This review examines recent trends, pregnancy prevention initiatives and family planning policies that address the special needs of vulnerable youth. Unintended teen pregnancies impose potentially serious social and health burdens on teen parents and their children, as well as costs to society. Trends in teen pregnancy and birth rates show continued decline, but state and racial disparities have widened. Demographic factors and policy changes have contributed to these disparities. Research supports comprehensive pregnancy prevention initiatives that are multifaceted and promote consistent and correct use of effective methods of contraception for youth at risk of becoming pregnant. There is strong consensus that effective teen pregnancy prevention strategies should be multifaceted, focusing on delay of sexual activity especially in younger teens while promoting consistent and correct use of effective methods of contraception for those youth who are or plan to be sexually active. There is a need for further research to identify effective interventions for vulnerable populations.

Kinetics of waterborne fluoropolymers prepared by one-step semi-continuous emulsion polymerization of chlorotrifluoroethylene, vinyl acetate, butyl acrylate and Veova 10

NASA Astrophysics Data System (ADS)

Liu, H. Z.; Wang, M. H.; Wang, Z. F.; Bian, J. M.

2018-01-01

Due to using gaseous fluorine monomer with toxicity, waterborne fluoropolymers are synthesized by semi-continuous high-pressure emulsion polymerization method which differs from free-pressure emulsion polymerization. To dates, the research on preparing process and kinetics for high-pressure emulsion polymerization is reported relatively less, which hinders researchers from understanding of mechanisms for monomer-fluorinated emulsion polymerization. The paper also provides a new method by element auxiliary analysis to calculate kinetics parameters of high-pressure emulsion polymerization. Based on aforementioned consideration, waterborne fluoropolymers were prepared by copolymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), butyl acrylate (BA) and vinyl ester of versatic acid (Veova 10) using potassium persulfate as initiator and mixed surfactants. The kinetics of emulsion polymerization of waterborne fluoropolymers was then investigated. Effects of emulsifier concentration, initiator concentration, and polymerization temperature on polymerization rate (Rp) were evaluated, and relationship was described as Rp∝[I]0.10 and Rp∝[E]0.12. The apparent activation energy was determined to be 33.61 kJ·mol-1. Moreover, the relative conversion rate of CTFE with the other monomers was observed, and results indicated that CTFE monomer more uniformly copolymerized with the other monomers. The resulting emulsion properties and pressure change in an autoclave were evaluated at different stirring rates. The initial reaction time, defined as the beginning time of dropwise addition, was determined by the change in solid content and particle size of emulsion.

Hospital employee assault rates before and after enactment of the california hospital safety and security act.

PubMed

Casteel, Carri; Peek-Asa, Corinne; Nocera, Maryalice; Smith, Jamie B; Blando, James; Goldmacher, Suzi; O'Hagan, Emily; Valiante, David; Harrison, Robert

2009-02-01

This study examines changes in violent event rates to hospital employees before and after enactment of the California Hospital Safety and Security Act in 1995. We compared pre- and post-initiative employee assault rates in California (n = 116) emergency departments and psychiatric units with those in New Jersey (n = 50), where statewide workplace violence initiatives do not exist. Poisson regression with generalized estimating equations was used to compare assault rates between a 3-year pre-enactment period (1993-1995) and a 6-year post-enactment period (1996-2001) using New Jersey hospitals as a temporal control. Assault rates among emergency department employees decreased 48% in California post-enactment, compared with emergency department employee assault rates in New Jersey (rate ratio [RR] = 0.52, 95% confidence interval [CI]: 0.31, 0.90). Emergency department employee assault rates decreased in smaller facilities (RR = 0.46, 95% CI: 0.21, 0.96) and for-profit-controlled hospitals (RR = 0.39, 95% CI: 0.19, 0.79) post-enactment. Among psychiatric units, for-profit-controlled hospitals (RR = 0.41, 95% CI: 0.19, 0.85) and hospitals located in smaller communities (RR = 0.44, 95% CI: 0.21, 0.92) experienced decreased assault rates post-enactment. Policy may be an effective method to increase safety to health care workers.

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution.

PubMed

Hopkins, Melanie J; Smith, Andrew B

2015-03-24

How ecological and morphological diversity accrues over geological time has been much debated by paleobiologists. Evidence from the fossil record suggests that many clades reach maximal diversity early in their evolutionary history, followed by a decline in evolutionary rates as ecological space fills or due to internal constraints. Here, we apply recently developed methods for estimating rates of morphological evolution during the post-Paleozoic history of a major invertebrate clade, the Echinoidea. Contrary to expectation, rates of evolution were lowest during the initial phase of diversification following the Permo-Triassic mass extinction and increased over time. Furthermore, although several subclades show high initial rates and net decreases in rates of evolution, consistent with "early bursts" of morphological diversification, at more inclusive taxonomic levels, these bursts appear as episodic peaks. Peak rates coincided with major shifts in ecological morphology, primarily associated with innovations in feeding strategies. Despite having similar numbers of species in today's oceans, regular echinoids have accrued far less morphological diversity than irregular echinoids due to lower intrinsic rates of morphological evolution and less morphological innovation, the latter indicative of constrained or bounded evolution. These results indicate that rates of evolution are extremely heterogenous through time and their interpretation depends on the temporal and taxonomic scale of analysis.

Dual-cycle dielectrophoretic collection rates for probing the dielectric properties of nanoparticles

PubMed Central

Bakewell, David J; Holmes, David

2013-01-01

A new DEP spectroscopy method and supporting theoretical model is developed to systematically quantify the dielectric properties of nanoparticles using continuously pulsed DEP collection rates. Initial DEP collection rates, that are dependent on the nanoparticle dielectric properties, are an attractive alternative to the crossover frequency method for determining dielectric properties. The new method introduces dual-cycle amplitude modulated and frequency-switched DEP (dual-cycle DEP) where the first collection rate with a fixed frequency acts as a control, and the second collection rate frequency is switched to a chosen value, such that, it can effectively probe the dielectric properties of the nanoparticles. The application of the control means that measurement variation between DEP collection experiments is reduced so that the frequency-switched probe collection is more effective. A mathematical model of the dual-cycle method is developed that simulates the temporal dynamics of the dual-cycle DEP nanoparticle collection system. A new statistical method is also developed that enables systematic bivariate fitting of the multifrequency DEP collection rates to the Clausius–Mossotti function, and is instrumental for determining dielectric properties. A Monte-Carlo simulation validates that collection rates improve estimation of the dielectric properties, compared with the crossover method, by exploiting a larger number of independent samples. Experiments using 200 nm diameter latex nanospheres suspended in 0.2 mS/m KCl buffer yield a nanoparticle conductivity of 26 mS/m that lies within 8% of the expected value. The results show that the dual-frequency method has considerable promise particularly for automated DEP investigations and associated technologies. PMID:23172363

Response Surface Methodology for Design of Porous Hollow Sphere Thermal Insulator

NASA Astrophysics Data System (ADS)

Shohani, Nazanin; Pourmahdian, Saeed; Shirkavand Hadavand, Behzad

2017-11-01

In this study, response surface method is used for synthesizing polystyrene (PS) as sacrificial templates and optimizing the particle size. Three factors of initiator, stabilizer concentration and also stirring rate were selected as variable factors. Then, three different concentration of tetraethyl orthosilicate (TEOS) added to reaction media and core-shell structure with PS core and silica shell was developed. Finally, core-shell structure was changed to hollow silica sphere for using as thermal insulator. We observed that increased initiator concentration caused to larger PS particles, increase the stirring rate caused the smaller PS and also with increased the stabilizer concentration obtained that particle size decrease then after 2.5% began to increase. Also the optimum amount of TEOS was found.

Hearing conservation in the primary aluminium industry

PubMed Central

Frisch, N.; Dixon-Ernst, C.; Chesson, B. J.; Cullen, M. R.

2016-01-01

Background Noise-induced hearing loss has been an intractable problem for heavy industry. Aims To report our experience in reducing the incidence of age-corrected confirmed 10 dB hearing shifts (averaged over 2, 3 and 4kHz) in employees in the primary aluminium industry in Australia over the period 2006–13. Methods We analysed annual audiometric data to determine the number of permanent hearing shifts that occurred in employees in two bauxite mines, three alumina refineries and two aluminium smelters. Annual hearing shift rates were calculated based on the number of employees tested per year. Hearing conservation initiatives undertaken during the study period are described. An assessment of similar exposure group noise exposures was also undertaken to determine the magnitude of noise exposure reduction during the study period. Results Across all operations, hearing shift rates declined from 5.5% per year in 2006 to 1.3% per year in 2013 (P < 0.001). The decline in shift rates was greater in mines and refineries, where baseline shift rates were higher, than in smelter workers. Modest reductions in noise exposure occurred during the study period. Conclusions We observed a substantial decline in hearing shift rates during the study period. We describe the hearing conservation initiatives that were collectively associated with this decline. We suspect these initiatives could be deployed relatively easily and at modest cost in other industries with noise-exposed employees. PMID:26470945

A study on the sensitivity of self-powered neutron detectors (SPNDs)

NASA Astrophysics Data System (ADS)

Lee, Wanno; Cho, Gyuseong; Kim, Kwanghyun; Kim, Hee Joon; choi, Yuseon; Park, Moon Chu; Kim, Soongpyung

2001-08-01

Self-powered neutron detectors (SPNDs) are widely used in reactors to monitor neutron flux, while they have several advantages such as small size, and relatively simple electronics required in conjunction with those usages, they have some intrinsic problems of the low level of output current-a slow response time and the rapid change of sensitivity-that make it difficult to use for a long term. Monte Carlo simulation was used to calculate the escape probability as a function of the birth position of emitted beta particle for geometry of rhodium-based SPNDs. A simple numerical method calculated the initial generation rate of beta particles and the change of generation rate due to rhodium burnup. Using results of the simulation and the simple numerical method, the burnup profile of rhodium number density and the neutron sensitivity were calculated as a function of burnup time in reactors. This method was verified by the comparison of this and other papers, and data of YGN3.4 (Young Gwang Nuclear plant 3, 4) about the initial sensitivity. In addition, for improvement of some properties of rhodium-based SPNDs, which are currently used, a modified geometry is proposed. The proposed geometry, which is tube-type, is able to increase the initial sensitivity due to increase of the escape probability. The escape probability was calculated by changing the thickness of the insulator and compared solid-type with tube-type about each insulator thickness. The method used here can be applied to the analysis and design of other types of SPNDs.

Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smoothed particle hydrodynamics

DOE PAGES

Pan, Wenxiao; Daily, Michael; Baker, Nathan A.

2015-05-07

Background: The calculation of diffusion-controlled ligand binding rates is important for understanding enzyme mechanisms as well as designing enzyme inhibitors. Methods: We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) BC, is considered on the reactive boundaries. This new BC treatment allows for the analysis of enzymes with “imperfect” reaction rates. Results: The numerical method is first verified in simple systems and thenmore » applied to the calculation of ligand binding to a mouse acetylcholinesterase (mAChE) monomer. Rates for inhibitor binding to mAChE are calculated at various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Conclusions: Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.« less

Time-optimal trajectory planning for underactuated spacecraft using a hybrid particle swarm optimization algorithm

NASA Astrophysics Data System (ADS)

Zhuang, Yufei; Huang, Haibin

2014-02-01

A hybrid algorithm combining particle swarm optimization (PSO) algorithm with the Legendre pseudospectral method (LPM) is proposed for solving time-optimal trajectory planning problem of underactuated spacecrafts. At the beginning phase of the searching process, an initialization generator is constructed by the PSO algorithm due to its strong global searching ability and robustness to random initial values, however, PSO algorithm has a disadvantage that its convergence rate around the global optimum is slow. Then, when the change in fitness function is smaller than a predefined value, the searching algorithm is switched to the LPM to accelerate the searching process. Thus, with the obtained solutions by the PSO algorithm as a set of proper initial guesses, the hybrid algorithm can find a global optimum more quickly and accurately. 200 Monte Carlo simulations results demonstrate that the proposed hybrid PSO-LPM algorithm has greater advantages in terms of global searching capability and convergence rate than both single PSO algorithm and LPM algorithm. Moreover, the PSO-LPM algorithm is also robust to random initial values.

Polarization Resistance Measurement in Tap Water: The Influence of Rust Electrochemical Activity

NASA Astrophysics Data System (ADS)

Vasyliev, Georgii

2017-08-01

Corrosion rate of mild steel in tap water during 4300 h was estimated by LPR and weight-loss methods coupled with OCP measurements. The LPR results were found to be overestimated compared to the weight-loss data within initial 2000 h of exposure. The electrochemical activity of the rust separated from the metal surface was studied by cycling voltammetry using a home-built powder graphite electrode. High redox currents corresponding to the initial 2000 h of exposure were detected. Rust composition was characterized with IR and XRD, and the highest amounts of electrochemically active β- and γ-FeOOH were again detected for the initial 2000 h. Current consumption in rust transformation processes during LPR measurement in the galvanostatic mode accounts for overestimation of the corrosion rate. The time dependence of rust electrochemical activity correlates with OCP variation with time. During initial 2000 h, OCP values are shifted by 50 mV to cathodic side. For the period of a higher rust electrochemical activity, the use of a reduced B is suggested to increase accuracy of LPR technique in tap water.

Finite-element nonlinear transient response computer programs PLATE 1 and CIVM-PLATE 1 for the analysis of panels subjected to impulse or impact loads

NASA Technical Reports Server (NTRS)

Spilker, R. L.; Witmer, E. A.; French, S. E.; Rodal, J. J. A.

1980-01-01

Two computer programs are described for predicting the transient large deflection elastic viscoplastic responses of thin single layer, initially flat unstiffened or integrally stiffened, Kirchhoff-Lov ductile metal panels. The PLATE 1 program pertains to structural responses produced by prescribed externally applied transient loading or prescribed initial velocity distributions. The collision imparted velocity method PLATE 1 program concerns structural responses produced by impact of an idealized nondeformable fragment. Finite elements are used to represent the structure in both programs. Strain hardening and strain rate effects of initially isotropic material are considered.

20171015 - Integrating Toxicity, Toxicokinetic, and Exposure Data for Risk-based Chemical Alternatives Assessment (ISES)

EPA Science Inventory

In order to predict the margin between the dose needed for adverse chemical effects and actual human exposure rates, data on hazard, exposure, and toxicokinetics are needed. In vitro methods, biomonitoring, and mathematical modeling have provided initial estimates for many extant...

ERDA/Lewis research center photovoltaic systems test facility

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Johnson, J. A.; Knapp, W. D.; Rigo, H.; Stover, J.; Suhay, R.

1977-01-01

A national photovoltaic power systems test facility (of initial 10-kW peak power rating) is described. It consists of a solar array to generate electrical power, test-hardware for several alternate methods of power conversion, electrical energy storage systems, and an instrumentation and data acquisition system.

Interpersonal Complementarity in the Mental Health Intake: A Mixed-Methods Study

ERIC Educational Resources Information Center

Rosen, Daniel C.; Miller, Alisa B.; Nakash, Ora; Halperin, Lucila; Alegria, Margarita

2012-01-01

The study examined which socio-demographic differences between clients and providers influenced interpersonal complementarity during an initial intake session; that is, behaviors that facilitate harmonious interactions between client and provider. Complementarity was assessed using blinded ratings of 114 videotaped intake sessions by trained…

Methods and Measures Used for Follow-up at 15 Years of the English and Romanian Adoptee (ERA) Study

ERIC Educational Resources Information Center

Monographs of the Society for Research in Child Development, 2010

2010-01-01

This chapter covers the methods and measures used in the ERA study, with a special focus on age 15 outcomes. First, the authors outline the sample participation rate for the 15-year follow-up--the percentages in all cases referring to the numbers at the time of initial sample contact. They then describe the measures used in this monograph,…

Creep strain and creep-life prediction for alloy 718 using the omega method

NASA Astrophysics Data System (ADS)

Yeom, Jong-Taek; Kim, Jong-Yup; Na, Young-Sang; Park, Nho-Kwang

2003-12-01

The creep behavior of Alloy 718 was investigated in relation to the MPCs omega (Ω) method. To evaluate the creep model and determine material parameters, constant load creep tests were performed at different initial stresses in a temperature range between 550°C and 700°C. The imaginary initial strain rate ɛ limits^. _0 and omega (Ω), considered to be important variables in the model, were expressed as a function of initial stress and temperature. For these variables, power-law and hyperbolic sine-law equations were used as constitutive equations for the creep of Alloy 718. To consider the effect of γ″ coarsening leading to a radical drop of tensile strength and creep strength at temperatures above 650°C, different material constants at the temperatures above 650°C were applied. The reliability of the models was investigated in relation to the creep curve and creep life.

Hydrocarbon polymeric binder for advanced solid propellant

NASA Technical Reports Server (NTRS)

Potts, J. E. (Editor)

1972-01-01

A series of DEAB initiated isoprene polymerizations were run in the 5-gallon stirred autoclave reactor. Polymerization run parameters such as initiator concentration and feed rate were correlated with the molecular weight to provide a basis for molecular weight control in future runs. Synthetic methods were developed for the preparation of n-1,3-alkadienes. By these methods, 1,3-nonadiene was polymerized using DEAB initiator to give an ester-telechelic polynonadiene. This was subsequently hydrogenated with copper chromite catalyst to give a hydroxyl terminated saturated liquid hydrocarbon prepolymer having greatly improved viscosity characteristics and a Tg 18 degrees lower than that of the hydrogenated polyisoprenes. The hydroxyl-telechelic saturated polymers prepared by the hydrogenolysis of ester-telechelic polyisoprene were reached with diisocyanates under conditions favoring linear chain extension gel permeation chromatography was used to monitor this condensation polymerization. Fractions having molecular weights above one million were produced.

Reduction of radial-head subluxation in children by triage nurses in the emergency department: a cluster-randomized controlled trial

PubMed Central

Dixon, Andrew; Clarkin, Chantalle; Barrowman, Nick; Correll, Rhonda; Osmond, Martin H.; Plint, Amy C.

2014-01-01

Background: Radial-head subluxation is an easily identified and treated injury. We investigated whether triage nurses in the emergency department can safely reduce radial-head subluxation at rates that are not substantially lower than those of emergency department physicians. Methods: We performed an open, noninferiority, cluster-randomized control trial. Children aged 6 years and younger who presented to the emergency department with a presentation consistent with radial-head subluxation and who had sustained a known injury in the previous 12 hours were assigned to either nurse-initiated or physician-initiated treatment, depending on the day. The primary outcome was the proportion of children who had a successful reduction (return to normal arm usage). We used a noninferiority margin of 10%. Results: In total, 268 children were eligible for inclusion and 245 were included in the final analysis. Of the children assigned to receive physician-initiated care, 96.7% (117/121) had a successful reduction performed by a physician. Of the children assigned to receive nurse-treatment care, 84.7% (105/124) had a successful reduction performed by a nurse. The difference in the proportion of successful radial head subluxations between the groups was 12.0% (95% confidence interval [CI] 4.8% to 19.7%). Noninferiority of nurse-initiated radial head subluxation was not shown. Interpretation: In this trial, the rate of successful radial-head subluxation performed by nurses was inferior to the physician success rate. Although the success rate in the nurse-initiated care group did not meet the non-inferiority margin, nurses were able to reduce radial head subluxation for almost 85% of children who presented with probable radial-head subluxation. Trial registration: Clinical Trials.gov, no. NCT00993954. PMID:24664649

Temporal trends of time to antiretroviral treatment initiation, interruption and modification: examination of patients diagnosed with advanced HIV in Australia.

PubMed

Wright, Stephen T; Law, Matthew G; Cooper, David A; Keen, Phillip; McDonald, Ann; Middleton, Melanie; Woolley, Ian; Kelly, Mark; Petoumenos, Kathy

2015-01-01

HIV prevention strategies are moving towards reducing plasma HIV RNA viral load in all HIV-positive persons, including those undiagnosed, treatment naïve, on or off antiretroviral therapy. A proxy population for those undiagnosed are patients that present late to care with advanced HIV. The objectives of this analysis are to examine factors associated with patients presenting with advanced HIV, and establish rates of treatment interruption and modification after initiating ART. We deterministically linked records from the Australian HIV Observational Database to the Australian National HIV Registry to obtain information related to HIV diagnosis. Logistic regression was used to identify factors associated with advanced HIV diagnosis. We used survival methods to evaluate rates of ART initiation by diagnosis CD4 count strata and by calendar year of HIV diagnosis. Cox models were used to determine hazard of first ART treatment interruption (duration >30 days) and time to first major ART modification. Factors associated (p<0.05) with increased odds of advanced HIV diagnosis were sex, older age, heterosexual mode of HIV exposure, born overseas and rural-regional care setting. Earlier initiation of ART occurred at higher rates in later periods (2007-2012) in all diagnosis CD4 count groups. We found an 83% (69, 91%) reduction in the hazard of first treatment interruption comparing 2007-2012 versus 1996-2001 (p<0.001), and no difference in ART modification for patients diagnosed with advanced HIV. Recent HIV diagnoses are initiating therapy earlier in all diagnosis CD4 cell count groups, potentially lowering community viral load compared to earlier time periods. We found a marked reduction in the hazard of first treatment interruption, and found no difference in rates of major modification to ART by HIV presentation status in recent periods.

A Statewide System for Improving Influenza Vaccination Rates in Hospital Employees

PubMed Central

Polgreen, Philip M.; Polgreen, Linnea A.; Evans, Thomas; Helms, Charles

2010-01-01

OBJECTIVE To describe and report the progress of a provider-initiated approach to increase influenza immunization rates for healthcare workers. DESIGN Observational study. SETTING The State of Iowa. SUBJECTS Acute care hospitals in Iowa. METHODS Hospitals reported rates of employee influenza vaccination to a provider-based collaborative during 2 influenza seasons (2006–2007 and 2007–2008). Hospital characteristics related to higher vaccination rates were examined. RESULTS One hundred (87.0%) of 115 Iowa hospitals and/or health systems participated in season 1; individual hospital vaccination rates ranged from 43.5% to 99.2% (mean, 72.4%; median, 73.1%). In season 2, 115 (100%) of 115 Iowa hospitals and/or health systems participated. Individual hospital vaccination rates ranged from 53.6% to 100% (mean, 79.5%; median, 82.0%). In both seasons, urban and large hospitals had vaccination rates that were 6.3% to 7.6% lower than those of hospitals in other locations. Hospitals that used declination statements had influenza vaccination rates 12.6% higher than hospitals that did not use declination statements in season 2. CONCLUSION The initial vaccination rates were high for healthcare workers in Iowa, especially in smaller rural hospitals, and rates increased during season 2. The successful voluntary approach for reporting influenza vaccination rates that we describe provides an efficient platform for collecting and disseminating other statewide measures of healthcare quality. PMID:19327039

The association between parental interaction style and children’s joint engagement in families with toddlers with autism

PubMed Central

Patterson, Stephanie Y; Elder, Lauren; Gulsrud, Amanda; Kasari, Connie

2014-01-01

Purpose This study examines the relationship between parental interaction style (responsive vs directive) and child-initiated joint engagement within caregiver–child interactions with toddlers diagnosed with autism spectrum disorders. Method Videotaped interactions of 85 toddler–caregiver dyads were coded for child engagement and both parental responsiveness and directiveness. Results Altogether, children spent less than one-third of the interaction jointly engaged. After controlling for child characteristics, parental style was associated with the initiator (child or parent) of joint engagement. Specifically, responsiveness predicted total time in child-initiated joint engagement, while directiveness predicted total time in parent-initiated joint engagement. Children’s social behaviours were associated with child-initiated joint engagement. Discussion Social initiations are a key target for children with autism spectrum disorders. Results demonstrate that child initiations and global social behaviour ratings are associated with parental responsivity. Responsivity may be a critical factor to facilitate children’s initiations. PMID:24104518

High single-session success rate of endoscopic bilateral stent-in-stent placement with modified large cell Niti-S stents for malignant hilar biliary obstruction.

PubMed

Kogure, Hirofumi; Isayama, Hiroyuki; Nakai, Yousuke; Tsujino, Takeshi; Matsubara, Saburo; Yashima, Yoko; Ito, Yukiko; Hamada, Tsuyoshi; Takahara, Naminatsu; Miyabayashi, Koji; Mizuno, Suguru; Mohri, Dai; Kawakubo, Kazumichi; Sasaki, Takashi; Yamamoto, Natsuyo; Hirano, Kenji; Sasahira, Naoki; Tada, Minoru; Koike, Kazuhiko

2014-01-01

Endoscopic bilateral self-expandable metallic stent (SEMS) placement in a stent-in-stent method for malignant hilar biliary obstruction is technically challenging. Technical difficulties in the initial placement and reinterventions for stent occlusion are disadvantages inherent to this stent-in-stent method. We previously reported the feasibility of Niti-S large cell D-type biliary stents (LCD). This multicenter prospective consecutive study evaluated the efficacy of bilateral SEMS placement using modified LCD with large and uniform cells, a slimmer delivery system and high radial force. From July 2010 to June 2011, 26 consecutive patients with unresectable malignant hilar biliary obstruction underwent endoscopic bilateral placement of modified LCD in a stent-in-stent method at three tertiary hospitals. Ten patients had gallbladder cancer, eight had cholangiocarcinoma, four had lymph node metastasis, two had intrahepatic cholangiocarcinoma, and two had liver metastasis. Single-session and final technical success rate was 96% and 100%, respectively. Functional success rate was 89%. Stent occlusion occurred in 11 patients (42%) because of sludge (n = 7) or tumor ingrowth (n = 4). Endoscopic bilateral reintervention was technically easy and successful: six patients had stent clearance by balloon sweeping and five had plastic stent placement. According to Kaplan-Meier analysis, median survival and stent patency were 220 days and 157 days, respectively. Modified LCD achieved a high technical success rate both in the initial stent-in-stent placement and in bilateral reinterventions in patients with malignant hilar biliary obstruction. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Observer perceptions of pain in children with cognitive impairments: vignette development and validation.

PubMed

Genik, Lara M; McMurtry, C Meghan; Breau, Lynn M

2015-01-01

Develop vignettes depicting different pain types in verbal and nonverbal children with cognitive impairments that could help examine pain assessment and management decisions of secondary caregivers, and conduct initial convergent and divergent validity analyses. For six vignettes, 76 undergraduate students (38 females, mean age = 19.55) rated (0-10): pain intensity, difficulty rating pain intensity, need for medical attention and need for other attention (e.g., physical comfort). Ratings significantly varied by pain source (e.g., headache was rated more painful than injections). Verbal ability did not impact ratings. Vignettes could serve as an alternative method to study pain decisions by caregivers of children with cognitive impairments when ethical barriers limit more naturalistic research.

The solution of linear systems of equations with a structural analysis code on the NAS CRAY-2

NASA Technical Reports Server (NTRS)

Poole, Eugene L.; Overman, Andrea L.

1988-01-01

Two methods for solving linear systems of equations on the NAS Cray-2 are described. One is a direct method; the other is an iterative method. Both methods exploit the architecture of the Cray-2, particularly the vectorization, and are aimed at structural analysis applications. To demonstrate and evaluate the methods, they were installed in a finite element structural analysis code denoted the Computational Structural Mechanics (CSM) Testbed. A description of the techniques used to integrate the two solvers into the Testbed is given. Storage schemes, memory requirements, operation counts, and reformatting procedures are discussed. Finally, results from the new methods are compared with results from the initial Testbed sparse Choleski equation solver for three structural analysis problems. The new direct solvers described achieve the highest computational rates of the methods compared. The new iterative methods are not able to achieve as high computation rates as the vectorized direct solvers but are best for well conditioned problems which require fewer iterations to converge to the solution.

The Effect of the Heat Flux on the Self-Ignition of Oriented Strand Board

NASA Astrophysics Data System (ADS)

Hirle, Siegfried; Balog, Karol

2017-06-01

This article deals with the initiation phase of flaming and smouldering burning of oriented strand board. The influence of heat flux on thermal degradation of OSB boards, time to ignition, heat release rate and mass loss rate using thermal analysis and vertical electrical radiation panel methods were studied. Significant information on the influence of the heat flux density and the thickness of the material on time to ignition was obtained.

The copper intrauterine device for emergency contraception: an opportunity to provide the optimal emergency contraception method and transition to highly effective contraception.

PubMed

Dermish, Amna I; Turok, David K

2013-07-01

Worldwide, 40% of all pregnancies are unintended. Widespread, over-the-counter availability of oral emergency contraception (EC) has not reduced unintended pregnancy rates. The EC visit presents an opportunity to initiate a highly effective method of contraception in a population at high risk of unintended pregnancy who are actively seeking to avoid pregnancy. The copper intrauterine device (IUD), the most effective method of EC, continues to provide contraception as effective as sterilization for up to 12 years, and it should be offered as the first-line method of EC wherever possible. Increased demand for and supply of the copper IUD for EC may have an important role in reducing rates of unintended pregnancy. The EC visit should include access to the copper IUD as optimal care but should ideally include access to all highly effective methods of contraception.

Hiring Practices for Human Resource Professionals: Implications for Counseling and Curriculum Development.

ERIC Educational Resources Information Center

Goza, Barbara K.; Lau, Andrea DeBellis

1992-01-01

Employers (n=107) of human resource professionals described their hiring practices. Only 13 companies had human resource internship placements for college students. Most widely used methods for recruiting were newspapers, informal channels, and internal recruitment. Highest rating for initial screening criteria were given to job experience in…

20 CFR 227.2 - Initial supplemental annuity rate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Initial supplemental annuity rate. 227.2... COMPUTING SUPPLEMENTAL ANNUITIES § 227.2 Initial supplemental annuity rate. The supplemental annuity rate... supplemental annuity rate is $43 for an employee with 30 or more years of service. ...

Studies of Low Luminosity Active Galactic Nuclei with Monte Carlo and Magnetohydrodynamic Simulations

NASA Astrophysics Data System (ADS)

Hilburn, Guy Louis

Results from several studies are presented which detail explorations of the physical and spectral properties of low luminosity active galactic nuclei. An initial Sagittarius A* general relativistic magnetohydrodynamic simulation and Monte Carlo radiation transport model suggests accretion rate changes as the dominant flaring method. A similar study on M87 introduces new methods to the Monte Carlo model for increased consistency in highly energetic sources. Again, accretion rate variation seems most appropriate to explain spectral transients. To more closely resolve the methods of particle energization in active galactic nuclei accretion disks, a series of localized shearing box simulations explores the effect of numerical resolution on the development of current sheets. A particular focus on numerically describing converged current sheet formation will provide new methods for consideration of turbulence in accretion disks.

Effectiveness of Ear Splint Therapy for Ear Deformities

PubMed Central

2017-01-01

Objective To present our experience with ear splint therapy for babies with ear deformities, and thereby demonstrate that this therapy is an effective and safe intervention without significant complications. Methods This was a retrospective study of 54 babies (35 boys and 19 girls; 80 ears; age ≤3 months) with ear deformities who had received ear splint therapy at the Center for Torticollis, Department of Physical Medicine and Rehabilitation, Ajou University Hospital between December 2014 and February 2016. Before the initiation of ear splint therapy, ear deformities were classified with reference to the standard terminology. We compared the severity of ear deformity before and after ear splint therapy by using the physician's ratings. We also compared the physician's ratings and the caregiver's ratings on completion of ear splint therapy. Results Among these 54 babies, 41 children (58 ears, 72.5%) completed the ear splint therapy. The mean age at initiation of therapy was 52.91±18.26 days and the treatment duration was 44.27±32.06 days. Satyr ear, forward-facing ear lobe, Darwinian notch, overfolded ear, and cupped ear were the five most common ear deformities. At the completion of therapy, the final physician's ratings of ear deformities were significantly improved compared to the initial ratings (8.28±1.44 vs. 2.51±0.92; p<0.001). There was no significant difference between the physician's ratings and the caregiver's ratings at the completion of ear splint therapy (8.28±1.44 vs. 8.0±1.61; p=0.297). Conclusion We demonstrated that ear splint therapy significantly improved ear deformities in babies, as measured by quantitative rating scales. Ear splint therapy is an effective and safe intervention for babies with ear deformities. PMID:28289646

[Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

PubMed

Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

1994-01-01

Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

A new highly sensitive method to assess respiration rates and kinetics of natural planktonic communities by use of the switchable trace oxygen sensor and reduced oxygen concentrations.

PubMed

Tiano, Laura; Garcia-Robledo, Emilio; Revsbech, Niels Peter

2014-01-01

Oxygen respiration rates in pelagic environments are often difficult to quantify as the resolutions of our methods for O2 concentration determination are marginal for observing significant decreases during bottle incubations of less than 24 hours. Here we present the assessment of a new highly sensitive method, that combine Switchable Trace Oxygen (STOX) sensors and all-glass bottle incubations, where the O2 concentration was artificially lowered. The detection limit of respiration rate by this method is inversely proportional to the O2 concentration, down to <2 nmol L(-1) h(-1) for water with an initial O2 concentration of 500 nmol L(-1). The method was tested in Danish coastal waters and in oceanic hypoxic waters. It proved to give precise measurements also with low oxygen consumption rates (∼7 nmol L(-1) h(-1)), and to significantly decrease the time required for incubations (≤14 hours) compared to traditional methods. This method provides continuous real time measurements, allowing for a number of diverse possibilities, such as modeling the rate of oxygen decrease to obtain kinetic parameters. Our data revealed apparent half-saturation concentrations (Km values) one order of magnitude lower than previously reported for marine bacteria, varying between 66 and 234 nmol L(-1) O2. Km values vary between different microbial planktonic communities, but our data show that it is possible to measure reliable respiration rates at concentrations ∼0.5-1 µmol L(-1) O2 that are comparable to the ones measured at full air saturation.

Reaction Event Counting Statistics of Biopolymer Reaction Systems with Dynamic Heterogeneity.

PubMed

Lim, Yu Rim; Park, Seong Jun; Park, Bo Jung; Cao, Jianshu; Silbey, Robert J; Sung, Jaeyoung

2012-04-10

We investigate the reaction event counting statistics (RECS) of an elementary biopolymer reaction in which the rate coefficient is dependent on states of the biopolymer and the surrounding environment and discover a universal kinetic phase transition in the RECS of the reaction system with dynamic heterogeneity. From an exact analysis for a general model of elementary biopolymer reactions, we find that the variance in the number of reaction events is dependent on the square of the mean number of the reaction events when the size of measurement time is small on the relaxation time scale of rate coefficient fluctuations, which does not conform to renewal statistics. On the other hand, when the size of the measurement time interval is much greater than the relaxation time of rate coefficient fluctuations, the variance becomes linearly proportional to the mean reaction number in accordance with renewal statistics. Gillespie's stochastic simulation method is generalized for the reaction system with a rate coefficient fluctuation. The simulation results confirm the correctness of the analytic results for the time dependent mean and variance of the reaction event number distribution. On the basis of the obtained results, we propose a method of quantitative analysis for the reaction event counting statistics of reaction systems with rate coefficient fluctuations, which enables one to extract information about the magnitude and the relaxation times of the fluctuating reaction rate coefficient, without a bias that can be introduced by assuming a particular kinetic model of conformational dynamics and the conformation dependent reactivity. An exact relationship is established between a higher moment of the reaction event number distribution and the multitime correlation of the reaction rate for the reaction system with a nonequilibrium initial state distribution as well as for the system with the equilibrium initial state distribution.

New closed analytical solutions for geometrically thick fluid tori around black holes. Numerical evolution and the onset of the magneto-rotational instability

NASA Astrophysics Data System (ADS)

Witzany, V.; Jefremov, P.

2018-06-01

Context. When a black hole is accreting well below the Eddington rate, a geometrically thick, radiatively inefficient state of the accretion disk is established. There is a limited number of closed-form physical solutions for geometrically thick (nonselfgravitating) toroidal equilibria of perfect fluids orbiting a spinning black hole, and these are predominantly used as initial conditions for simulations of accretion in the aforementioned mode. However, different initial configurations might lead to different results and thus observational predictions drawn from such simulations. Aims: We aim to expand the known equilibria by a number of closed multiparametric solutions with various possibilities of rotation curves and geometric shapes. Then, we ask whether choosing these as initial conditions influences the onset of accretion and the asymptotic state of the disk. Methods: We have investigated a set of examples from the derived solutions in detail; we analytically estimate the growth of the magneto-rotational instability (MRI) from their rotation curves and evolve the analytically obtained tori using the 2D magneto-hydrodynamical code HARM. Properties of the evolutions are then studied through the mass, energy, and angular-momentum accretion rates. Results: The rotation curve has a decisive role in the numerical onset of accretion in accordance with our analytical MRI estimates: in the first few orbital periods, the average accretion rate is linearly proportional to the initial MRI rate in the toroids. The final state obtained from any initial condition within the studied class after an evolution of ten or more orbital periods is mostly qualitatively identical and the quantitative properties vary within a single order of magnitude. The average values of the energy of the accreted fluid have an irregular dependency on initial data, and in some cases fluid with energies many times its rest mass is systematically accreted.

Metronidazole combined with nystatin (vagitories) in the prevention of bacterial vaginosis after initial treatment with oral metronidazole.

PubMed

Pulkkinen, P; Saranen, M; Kaaja, R

1993-01-01

In a double-blind trial comprising 66 patients we assessed the effect of metronidazole-nystatin vagitories on the prevention of bacterial vaginosis (BV) in women using IUD as a contraceptive method after an initial oral single dose of 2.0 g metronidazole and 7 days of intravaginal metronidazole-nystatin or placebo treatment. The prophylactic treatment consisted of metronidazole-nystatin or placebo vagitories applied at bedtime for 3 days after menstruation over 6 consecutive menstrual periods. The patients were randomized in two study groups: a treatment group of 32 patients (group A) and a placebo group of 34 patients (group B). The overall objective cure rate after the initial treatment was 97% in group A and 91% in group B. After 6 months of follow-up, the overall cumulative objective cure rate in group A was 100%, and 76% in group B. The single-dose oral treatment was well tolerated and no notable side effects were recorded.

Did our current initial treatment practice change after EAU/ESPU vesicoureteral reflux risk grouping?

PubMed

Tokat, Eda; Gurocak, Serhat; Ure, Iyimser; Acar, Cenk; Sınık, Zafer; Tan, Mustafa Ozgur

2018-06-02

The "European Association of Urology (EAU) Guidelines on Vesicoureteral Reflux (VUR) in Children (September 2012)" established risk classification by analyzing and defining risk factors for each patient. In this study we aimed to investigate how our initial treatment procedures were affected by EAU/ESPU guideline vesicoureteral reflux risk grouping and to compare the early clinical results of treatments performed before and after the risk classification in our patients with VUR. 334 renal units with regular clinical follow-up who were treated owing to VUR (vesicoureteral reflux) between years 2009 and 2017 were retrospectively reviewed. Preoperative clinical parameters such as grade and laterality of reflux, presence of renal scar, initial and follow-up treatments, findings of medical treatment and surgical procedures were analyzed. The initial medical and surgical methods were compared by categorizing patients according to risk groups before and after 2013. Mean age and follow-up duration were 71.4(6-216) months and 47(4-141) months, respectively. Among the preoperative parameters, only high EAU risk group (p = 0.01) and treating lower urinary tract symptoms (p < 0.001) were determining the postoperative success rates significantly, while age, sex, and presence of renal scar at DMSA were not affecting the success of treatment significantly. While no significant difference in medical and surgical treatment rates is observed after risk grouping system in low risk group, the percentages of patients who are treated with surgical methods initially were significantly decreased in moderate and high risk groups (p = 0.002 and p = 0.012, respectively). We determined that VUR risk grouping did not change clinical success significantly in all risk groups. Despite the fact that EAU/ESPU VUR risk classification changed our current practice in terms of initial treatment method, this different approach did not seem to affect early clinical success positively. There is still an absolute need for studies with larger sample size and long-term follow-up to reach more reliable results. Therapeutic. Level 4. Copyright © 2018 Elsevier Inc. All rights reserved.

Validated selective spectrophotometric methods for the kinetic determination of desloratidine in tablets and in the presence of its parent drug.

PubMed

Derayea, S M Sayed

2014-11-01

Two novel selective validated methods have been developed for analysis of desloratidine (DSL) in its tablets formulation. Both were kinetic spectrophotometric methods, depend on the interaction of the secondary amino group in DSL with acetaldehyde to give N-vinylpiperidyl product. The formed N-vinylpiperidyl compound was reacted with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil) to form colored N-vinylpiperidyl-substituted benzoquinone derivatives. The formed blue-colored derivative was measured at 672 nm. The reaction conditions were carefully studied and all factors were optimized. The molar ratio between the reactants was estimated and a suggested reaction mechanism was presented. The analysis was carried out using initial rate and fixed time (at 6 min) methods. The linear concentration ranges were 3-50 and 10 - 60 μg mL-1 with limits of detection of 3.2 and 2.2 μg mL-1 for the initial rate and fixed time methods, respectively. ICH guidelines were applied for analytical performance validation of the proposed methods. The presence of common excipients in the pharmaceutical formulation did not produce any significant interference, as well as from loratadine, which is the parent compound of DSL. Different commercially available tablets formulations containing were successfully analyzed, with, the percentage recovery ranging from 97.28-100.90 ± 0.7 2-1.41%. The obtained results were compared statistically with the reported method results. The proposed methods have similar accuracy and precision as the reported as indicated from the F- and t-test data.

Factors Associated with Breastfeeding Initiation: A Comparison between France and French-Speaking Canada

PubMed Central

Girard, Lisa-Christine; Côté, Sylvana M.; de Lauzon-Guillain, Blandine; Dubois, Lise; Falissard, Bruno; Forhan, Anne; Doyle, Orla; Bernard, Jonathan Y.; Heude, Barbara; Saurel-Cubizolles, Marie-Josephe; Kaminski, Monique; Boivin, Michel; Tremblay, Richard E.

2016-01-01

Background Breastfeeding is associated with multiple domains of health for both mothers and children. Nevertheless, breastfeeding initiation is low within certain developed countries. Furthermore, comparative studies of initiation rates using harmonised data across multiple regions is scarce. Objective The aim of the present study was to investigate and compare individual-level determinants of breastfeeding initiation using two French-speaking cohorts. Methods Participants included ~ 3,900 mothers enrolled in two cohort studies in Canada and France. Interviews, questionnaires, and medical records were utilised to collect information on maternal, family, and medical factors associated with breastfeeding initiation. Results Rates of breastfeeding initiation were similar across cohorts, slightly above 70%. Women in both Canada and France who had higher levels of maternal education, were born outside of their respective countries and who did not smoke during pregnancy were more likely to initiate breastfeeding with the cohort infant. Notably, cohort effects of maternal education at the university level were found, whereby having ‘some university’ was not statistically significant for mothers in France. Further, younger mothers in Canada, who delivered by caesarean section and who had previous children, had reduced odds of breastfeeding initiation. These results were not found for mothers in France. Conclusions and Implications for Practice While some similar determinants were observed, programming efforts to increase breastfeeding initiation should be tailored to the characteristics of specific geographical regions which may be heavily impacted by the social, cultural and political climate of the region, in addition to individual and family level factors. PMID:27902741

Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

PubMed Central

Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong

2014-01-01

An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219

Nonlinear scalar forcing based on a reaction analogy

NASA Astrophysics Data System (ADS)

Daniel, Don; Livescu, Daniel

2017-11-01

We present a novel reaction analogy (RA) based forcing method for generating stationary passive scalar fields in incompressible turbulence. The new method can produce more general scalar PDFs (e.g. double-delta) than current methods, while ensuring that scalar fields remain bounded, unlike existent forcing methodologies that can potentially violate naturally existing bounds. Such features are useful for generating initial fields in non-premixed combustion or for studying non-Gaussian scalar turbulence. The RA method mathematically models hypothetical chemical reactions that convert reactants in a mixed state back into its pure unmixed components. Various types of chemical reactions are formulated and the corresponding mathematical expressions derived. For large values of the scalar dissipation rate, the method produces statistically steady double-delta scalar PDFs. Gaussian scalar statistics are recovered for small values of the scalar dissipation rate. In contrast, classical forcing methods consistently produce unimodal Gaussian scalar fields. The ability of the new method to produce fully developed scalar fields is discussed using 2563, 5123, and 10243 periodic box simulations.

Community Rates of Breastfeeding Initiation.

PubMed

Grubesic, Tony H; Durbin, Kelly M

2016-11-01

Breastfeeding initiation rates vary considerably across racial and ethnic groups, maternal age, and education level, yet there are limited data concerning the influence of geography on community rates of breastfeeding initiation. This study aimed to describe how community rates of breastfeeding initiation vary in geographic space, highlighting "hot spots" and "cool spots" of initiation and exploring the potential connections between race, socioeconomic status, and urbanization levels on these patterns. Birth certificate data from the Kentucky Department of Health for 2004-2010 were combined with county-level geographic base files, Census 2010 demographic and socioeconomic data, and Rural-Urban Continuum Codes to conduct a spatial statistical analysis of community rates of breastfeeding initiation. Between 2004 and 2010, the average rate of breastfeeding initiation for Kentucky increased from 43.84% to 49.22%. Simultaneously, the number of counties identified as breastfeeding initiation hot spots also increased, displaying a systematic geographic pattern in doing so. Cool spots of breastfeeding initiation persisted in rural, Appalachian Kentucky. Spatial regression results suggested that unemployment, income, race, education, location, and the availability of International Board Certified Lactation Consultants are connected to breastfeeding initiation. Not only do spatial analytics facilitate the identification of breastfeeding initiation hot spots and cool spots, but they can be used to better understand the landscape of breastfeeding initiation and help target breastfeeding education and/or support efforts.

Replication Validity of Initial Association Studies: A Comparison between Psychiatry, Neurology and Four Somatic Diseases

PubMed Central

Dumas-Mallet, Estelle; Button, Katherine; Boraud, Thomas; Munafo, Marcus; Gonon, François

2016-01-01

Context There are growing concerns about effect size inflation and replication validity of association studies, but few observational investigations have explored the extent of these problems. Objective Using meta-analyses to measure the reliability of initial studies and explore whether this varies across biomedical domains and study types (cognitive/behavioral, brain imaging, genetic and “others”). Methods We analyzed 663 meta-analyses describing associations between markers or risk factors and 12 pathologies within three biomedical domains (psychiatry, neurology and four somatic diseases). We collected the effect size, sample size, publication year and Impact Factor of initial studies, largest studies (i.e., with the largest sample size) and the corresponding meta-analyses. Initial studies were considered as replicated if they were in nominal agreement with meta-analyses and if their effect size inflation was below 100%. Results Nominal agreement between initial studies and meta-analyses regarding the presence of a significant effect was not better than chance in psychiatry, whereas it was somewhat better in neurology and somatic diseases. Whereas effect sizes reported by largest studies and meta-analyses were similar, most of those reported by initial studies were inflated. Among the 256 initial studies reporting a significant effect (p<0.05) and paired with significant meta-analyses, 97 effect sizes were inflated by more than 100%. Nominal agreement and effect size inflation varied with the biomedical domain and study type. Indeed, the replication rate of initial studies reporting a significant effect ranged from 6.3% for genetic studies in psychiatry to 86.4% for cognitive/behavioral studies. Comparison between eight subgroups shows that replication rate decreases with sample size and “true” effect size. We observed no evidence of association between replication rate and publication year or Impact Factor. Conclusion The differences in reliability between biological psychiatry, neurology and somatic diseases suggest that there is room for improvement, at least in some subdomains. PMID:27336301

Assessment of safety and efficacy of lamotrigine over the course of 1-year observation in Japanese patients with bipolar disorder: post-marketing surveillance study report

PubMed Central

Terao, Takeshi; Ishida, Atsuko; Kimura, Toshifumi; Yoshida, Mitsuhiro; Hara, Terufumi

2017-01-01

Background A post-marketing surveillance (PMS) study was conducted with a 1-year observation period to assess the safety and efficacy of lamotrigine in routine clinical practice in patients with bipolar disorder (BD). Patients and methods Central enrollment method was used to recruit patients diagnosed with BD who were being treated for the first time with lamotrigine to prevent the recurrence/relapse of BD mood episodes. Adverse drug reactions (ADRs) and recurrence/relapse were assessed. Improvement of mania and depression was also assessed using the Hamilton’s Rating Scale for Depression (HAM-D) and the Young Mania Rating Scale (YMRS) at treatment initiation, 4–6 months post treatment initiation, and 10–12 months post treatment initiation. Results A total of 237/989 patients (24.0%) reported ADRs, most commonly rash (9.1%), and the incidence of serious ADRs was 3.3% (33/989 patients). Skin disorders occurred in 130 patients (13.1%), mostly within 8 weeks post treatment. A total of 237/703 patients (33.7%) experienced recurrence/relapse of mood episodes. The 25th percentile of the time to recurrence/relapse of mood episodes was 105 days. Remission of depression symptoms (HAM-D ≤7) occurred in 147/697 patients (21.1%) at treatment initiation, rising to 361 patients (67.4%) at 10–12 months post treatment. Remission of manic symptoms (YMRS ≤13) occurred in 615/676 patients (91.0%) at treatment initiation, rising to 500 patients (97.3%) at 10–12 months post treatment. Conclusion The results of this PMS study suggest that lamotrigine is a well-tolerated and effective drug for preventing recurrence/relapse of BD in clinical practice. PMID:28652744

T wave alternans during exercise and atrial pacing in humans

NASA Technical Reports Server (NTRS)

Hohnloser, S. H.; Klingenheben, T.; Zabel, M.; Li, Y. G.; Albrecht, P.; Cohen, R. J.

1997-01-01

INTRODUCTION: Evidence is accumulating that microvolt T wave alternans (TWA) is a marker of increased risk for ventricular tachyarrhythmias. Initially, atrial pacing was used to elevate heart rate and elicit TWA. More recently, a noninvasive approach has been developed that elevates heart rate using exercise. METHODS AND RESULTS: In 30 consecutive patients with a history of ventricular tachyarrhythmias, the spectral method was used to detect TWA during both atrial pacing and submaximal exercise testing. The concordance rate for the presence or absence of TWA using the two measurement methods was 84%. There was a patient-specific heart rate threshold for the detection of TWA that averaged 100 +/- 14 beats/min during exercise compared with 97 +/- 9 beats/min during right atrial pacing (P = NS). Beyond this threshold, there was a significant and comparable increase in level of TWA with decreasing pacing cycle length and increasing exercise heart rates. CONCLUSIONS: The present study is the first to demonstrate that microvolt TWA can be assessed reliably and noninvasively during exercise stress. There is a patient-specific heart rate threshold beyond which TWA continues to increase with increasing heart rates. Heart rate thresholds for the onset of TWA measured during atrial pacing and exercise stress were comparable, indicating that heart rate alone appears to be the main factor of determining the onset of TWA during submaximal exercise stress.

Interaction of repetitively pulsed high energy laser radiation with matter

NASA Astrophysics Data System (ADS)

Hugenschmidt, M.

1986-05-01

Laser target interaction processes and methods of improving the overall energy balance are discussed. This can be achieved with high repetition rate pulsed lasers even for initially highly reflecting materials, such as metals. Experiments were performed using a pulsed CO2 laser at mean powers up to 2 KW and repetition rates up to 100 Hz. The rates of temperature rise of aluminum for example are increased by more than a factor of 3 as compared to cw-radiation of comparable power density. Similar improvements are found for the overall absorptivities, that are increased by more than an order of magnitude.

Recent Initiatives in the Republic of Srpska to Enhance Appropriate Use of Antibiotics in Ambulatory Care; Their Influence and Implications.

PubMed

Bojanić, Ljubica; Marković-Peković, Vanda; Škrbić, Ranko; Stojaković, Nataša; Ðermanović, Mirjana; Bojanić, Janja; Fürst, Jurij; Kurdi, Amanj B; Godman, Brian

2018-01-01

Introduction: There are increasing concerns world-wide with growing rates of antibiotic resistance necessitating urgent action. There have been a number of initiatives in the Republic of Srpska in recent years to address this and improve rational antibiotic prescribing and dispensing despite limited resources to fund multiple initiatives. Objective: Analyse antibiotic utilization patterns in the Republic of Srpska following these multiple initiatives as a basis for developing future programmes in the Republic if needed. Methods: Observational retrospective study of total outpatient antibiotic utilization from 2010 to 2015, based on data obtained from the Public Health Institute, alongside documentation of ongoing initiatives to influence utilization. The quality of antibiotic utilization principally assessed according to ESAC, ECDC, and WHO quality indicators and DU 90% (the drug utilization 90%) profile as well as vs. neighboring countries. Results: Following multiple initiatives, antibiotic utilization remained relatively stable in the Republic at 15.6 to 18.4 DIDs, with a decreasing trend in recent years, with rates comparable or lower than neighboring countries. Amoxicillin and the penicillins accounted for 29-40 and 50% of total utilization, respectively. Overall, limited utilization of co-amoxiclav (7-11%), cephalosporins, macrolides, and quinolones, as well as low use of third and fourth generation cephalosporins vs. first and second cephalosporins. However, increasing utilization of co-amoxiclav and azithromycin, as well as higher rates of quinolone utilization compared to some countries, was seen. Conclusions: Multiple interventions in the Republic of Srpska in recent years have resulted in one of the lowest utilization of antibiotics when compared with similar countries, acting as an exemplar to others. However, there are some concerns with current utilization of co-amoxiclav and azithromycin which are being addressed. This will be the subject of future research activities.

Dynamic evolutionary change in post-Paleozoic echinoids and the importance of scale when interpreting changes in rates of evolution

PubMed Central

Hopkins, Melanie J.; Smith, Andrew B.

2015-01-01

How ecological and morphological diversity accrues over geological time has been much debated by paleobiologists. Evidence from the fossil record suggests that many clades reach maximal diversity early in their evolutionary history, followed by a decline in evolutionary rates as ecological space fills or due to internal constraints. Here, we apply recently developed methods for estimating rates of morphological evolution during the post-Paleozoic history of a major invertebrate clade, the Echinoidea. Contrary to expectation, rates of evolution were lowest during the initial phase of diversification following the Permo-Triassic mass extinction and increased over time. Furthermore, although several subclades show high initial rates and net decreases in rates of evolution, consistent with “early bursts” of morphological diversification, at more inclusive taxonomic levels, these bursts appear as episodic peaks. Peak rates coincided with major shifts in ecological morphology, primarily associated with innovations in feeding strategies. Despite having similar numbers of species in today’s oceans, regular echinoids have accrued far less morphological diversity than irregular echinoids due to lower intrinsic rates of morphological evolution and less morphological innovation, the latter indicative of constrained or bounded evolution. These results indicate that rates of evolution are extremely heterogenous through time and their interpretation depends on the temporal and taxonomic scale of analysis. PMID:25713369

Association between adherence to an antimicrobial stewardship program and mortality among hospitalised cancer patients with febrile neutropaenia: a prospective cohort study

PubMed Central

2014-01-01

Background Initial management of chemotherapy-induced febrile neutropaenia (FN) comprises empirical therapy with a broad-spectrum antimicrobial. Currently, there is sufficient evidence to indicate which antibiotic regimen should be administered initially. However, no randomized trial has evaluated whether adherence to an antimicrobial stewardship program (ASP) results in lower rates of mortality in this setting. The present study sought to assess the association between adherence to an ASP and mortality among hospitalised cancer patients with FN. Methods We conducted a prospective cohort study in a single tertiary hospital from October 2009 to August 2011. All adult patients who were admitted to the haematology ward with cancer and FN were followed up for 28 days. ASP adherence to the initial antimicrobial prescription was determined. The mortality rates of patients who were treated with antibiotics according to the ASP protocol were compared with those of patients treated with other antibiotic regimens. The multivariate Cox proportional hazards model and propensity score were used to estimate 28-day mortality risk. Results A total of 307 FN episodes in 169 subjects were evaluated. The rate of adherence to the ASP was 53%. In a Cox regression analysis, adjusted for propensity scores and other potential confounding factors, ASP adherence was independently associated with lower mortality (hazard ratio, 0.36; 95% confidence interval, 0.14–0.92). Conclusions Antimicrobial selection is important for the initial management of patients with FN, and adherence to the ASP, which calls for the rational use of antibiotics, was associated with lower mortality rates in this setting. PMID:24884397

Evaluation of Foreign Investment in Power Plants using Real Options

NASA Astrophysics Data System (ADS)

Kato, Moritoshi; Zhou, Yicheng

This paper proposes new methods for evaluating foreign investment in power plants under market uncertainty using a real options approach. We suppose a thermal power plant project in a deregulated electricity market. One of our proposed methods is that we calculate the cash flow generated by the project in a reference year using actual market data to incorporate periodic characteristics of energy prices into a yearly cash flow model. We make the stochastic yearly cash flow model with the initial value which is the cash flow in the reference year, and certain trend and volatility. Then we calculate the real options value (ROV) of the project which has abandonment options using the yearly cash flow model. Another our proposed method is that we evaluate foreign currency/domestic currency exchange rate risk by representing ROV in foreign currency as yearly pay off and exchanging it to ROV in domestic currency using a stochastic exchange rate model. We analyze the effect of the heat rate and operation and maintenance costs of the power plant on ROV, and evaluate exchange rate risk through numerical examples. Our proposed method will be useful for the risk management of foreign investment in power plants.

DNS Study of the Ignition of n-Heptane Fuel Spray under HCCI Conditions

NASA Astrophysics Data System (ADS)

Wang, Yunliang; Rutland, Christopher J.

2004-11-01

Direct numerical simulations are carried out to investigate the mixing and auto-ignition processes of n-heptane fuel spray in a turbulent field using a skeletal chemistry mechanism with 44 species and 112 reactions. For the solution of the carrier gas fluid, we use the Eulerian method, while for the fuel spray, the Lagrangian method is used. We use an eighth-order finite difference scheme to calculate spacial derivatives and a fourth-order Runge-Kutta scheme for the time integration. The initial gas temperature is 926 K and the initial gas pressure is 30 atmospheres. The initial global equivalence ratio based on the fuel concentration is around 0.4. The initial droplet diameter is 60 macrons and the droplet temperature is 300 K. Evolutions of averaged temperature, species mass fraction, heat release and reaction rate are presented. Contours of temperature and species mass fractions are presented. The objective is to understand the mechanism of ignition under Homogeneous Charged Compression Ignition (HCCI) conditions, aiming at providing some useful information of HCCI combustion, which is one of the critical issues to be resolved.

Boiling water jet outflow from a thin nozzle: spatial modeling

NASA Astrophysics Data System (ADS)

Bolotnova, R. Kh.; Korobchinskaya, V. A.

2017-09-01

This study presents dual-temperature two-phase model for liquid-vapor mixture with account for evaporation and inter-phase heat transfer (taken in single-velocity single-pressure approximation). Simulation was performed using the shock-capturing method and moving Lagrangian grids. Analysis was performed for simulated and experimental values of nucleation frequency (for refining the initial number and radius of microbubbles) which affect the evaporation rate. Validity of 2D and 1D simulation was examined through comparison with experimental data. The peculiarities of the water-steam formation at the initial stage of outflow through a thin nozzle were studied for different initial equilibrium states of water for the conditions close to chosen experimental conditions.

Bedload transport associated with high stream power, Jordan River, Israel

PubMed Central

Inbar, Moshe; Schick, Asher P.

1979-01-01

During a flood of a magnitude that recurs once in 100 years, boulders up to 1700 mm in size were transported in the Jordan and Meshushim Rivers, northern Israel. Bedload discharge rates were estimated for periods of 3-72 hr of peak flow by a combination of hydrologic and geomorphic methods. Bedload transport rate is proportional to unit stream power in excess of that necessary for initial motion, raised to the power 3/2, as has been shown for data on other rivers. PMID:16592661

PLATINO, a nine-year follow-up study of COPD in the city of São Paulo, Brazil: the problem of underdiagnosis*

PubMed Central

Moreira, Graciane Laender; Manzano, Beatriz Martins; Gazzotti, Mariana Rodrigues; Nascimento, Oliver Augusto; Perez-Padilla, Rogelio; Menezes, Ana Maria Baptista; Jardim, José Roberto

2014-01-01

OBJECTIVE: To determine the underdiagnosis rate in new COPD cases at the end of a nine-year follow-up period-in the study designated "Projeto Latino-Americano de Investigação em Obstrução Pulmonar" (PLATINO, Latin-American Pulmonary Obstruction Investigation Project)-and compare that with the underdiagnosis rate during the initial phase of the study, as well as to identify the clinical features exhibited by the subjects who were not diagnosed until the end of the follow-up phase. METHODS: The study population comprised the 1,000 residents of the city of São Paulo, Brazil, who took part in the PLATINO study. Of those, 613 participated in the follow-up phase, during which the subjects were assessed with the same instruments and equipment employed in the initial phase of the study. We used the chi-square test or the independent sample t-test to analyze the underdiagnosis rate and to identify the characteristics of the subjects who were not diagnosed until the end of the follow-up phase. RESULTS: The underdiagnosis rate for new COPD cases at the end of the nine-year follow-up period was 70.0%. The underdiagnosis rate during the follow-up phase was 17.5% lower than that reported for the initial phase of the study. The subjects who were not diagnosed until the end of the follow-up phase presented with fewer respiratory symptoms, better pulmonary function, and less severe disease than did those previously diagnosed with COPD. CONCLUSIONS: The underdiagnosis rate for new COPD cases was lower in the follow-up phase of the study than in the initial phase. The subjects who were not diagnosed until the end of the follow-up phase of the PLATINO study presented with the same clinical profile as did those who were not diagnosed in the initial phase. These findings underscore the need for spirometry in order to confirm the diagnosis of COPD and provide early intervention. PMID:24626267

Sample substitution can be an acceptable data-collection strategy: the case of the Belgian Health Interview Survey.

PubMed

Demarest, Stefaan; Molenberghs, Geert; Van der Heyden, Johan; Gisle, Lydia; Van Oyen, Herman; de Waleffe, Sandrine; Van Hal, Guido

2017-11-01

Substitution of non-participating households is used in the Belgian Health Interview Survey (BHIS) as a method to obtain the predefined net sample size. Yet, possible effects of applying substitution on response rates and health estimates remain uncertain. In this article, the process of substitution with its impact on response rates and health estimates is assessed. The response rates (RR)-both at household and individual level-according to the sampling criteria were calculated for each stage of the substitution process, together with the individual accrual rate (AR). Unweighted and weighted health estimates were calculated before and after applying substitution. Of the 10,468 members of 4878 initial households, 5904 members (RRind: 56.4%) of 2707 households (RRhh: 55.5%) participated. For the three successive (matched) substitutes, the RR dropped to 45%. The composition of the net sample resembles the one of the initial samples. Applying substitution did not produce any important distorting effects on the estimates. Applying substitution leads to an increase in non-participation, but does not impact the estimations.

Growth trajectories of mathematics achievement: Longitudinal tracking of student academic progress.

PubMed

Mok, Magdalena M C; McInerney, Dennis M; Zhu, Jinxin; Or, Anthony

2015-06-01

A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). This study aimed at modelling the mathematics growth of students over a span of 6 years from Grade 3 to Grade 9. The sample comprised secondary longitudinal data collected in three waves from n = 866 Hong Kong students when they were in Grade 3, Grade 6, and Grade 9. Mathematics achievement was measured thrice on a vertical scale linked with anchor items. Linear and nonlinear latent growth models were used to assess students' growth. Gender differences were also examined. A nonlinear latent growth curve with a decelerated rate had a good fit to the data. Initial achievement and growth rate were negatively correlated. No gender difference was found. Mathematics growth from Grade 6 to Grade 9 was slower than that from Grade 3 to Grade 6. Students with lower initial achievement improved at a faster rate than those who started at a higher level. Gender did not affect growth rate. © 2014 The British Psychological Society.

Real-time CT-video registration for continuous endoscopic guidance

NASA Astrophysics Data System (ADS)

Merritt, Scott A.; Rai, Lav; Higgins, William E.

2006-03-01

Previous research has shown that CT-image-based guidance could be useful for the bronchoscopic assessment of lung cancer. This research drew upon the registration of bronchoscopic video images to CT-based endoluminal renderings of the airway tree. The proposed methods either were restricted to discrete single-frame registration, which took several seconds to complete, or required non-real-time buffering and processing of video sequences. We have devised a fast 2D/3D image registration method that performs single-frame CT-Video registration in under 1/15th of a second. This allows the method to be used for real-time registration at full video frame rates without significantly altering the physician's behavior. The method achieves its speed through a gradient-based optimization method that allows most of the computation to be performed off-line. During live registration, the optimization iteratively steps toward the locally optimal viewpoint at which a CT-based endoluminal view is most similar to a current bronchoscopic video frame. After an initial registration to begin the process (generally done in the trachea for bronchoscopy), subsequent registrations are performed in real-time on each incoming video frame. As each new bronchoscopic video frame becomes available, the current optimization is initialized using the previous frame's optimization result, allowing continuous guidance to proceed without manual re-initialization. Tests were performed using both synthetic and pre-recorded bronchoscopic video. The results show that the method is robust to initialization errors, that registration accuracy is high, and that continuous registration can proceed on real-time video at >15 frames per sec. with minimal user-intervention.

Production of Monodisperse Cerium Oxide Microspheres with Diameters near 100 µm by Internal-Gelation Sol-Gel Methods

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

Katalenich, Jeffrey A.; Kitchen, Brian B.; Pierson, Bruce

Cerium dioxide microspheres with uniform diameters between 65 – 211 µm were fabricated using internal gelation sol-gel methods. Although uniform microspheres are produced for nuclear fuel applications with diameters above 300 µm, sol-gel microspheres with diameters of 50 - 200 µm have historically been made by emulsion techniques and had poor size uniformity [1, 2]. An internal gelation, sol-gel apparatus was designed and constructed to accommodate the production of small, uniform microspheres whereby cerium-containing solutions were dispersed into flowing silicone oil and heated in a gelation column to initiate solidification [3, 4]. Problems with premature feed gelation and microsphere coalescencemore » were overcome by equipment modifications unique among known internal gelation setups. Microspheres were fabricated and sized in batches as a function of dispersing needle diameter and silicone oil flow rate in the two-fluid nozzle in order to determine the range of sizes possible and corresponding degree of monodispersity. Initial experiments with poor size uniformity were linked to microsphere coalescence in the gelation column prior to solidification as well as excessive flow rates for the cerium feed solution. Average diameter standard deviations as low as 2.23% were observed after optimization of flow rates and minimization of coalescence reactions.« less

Production of monodisperse cerium oxide microspheres with diameters near 100 µm by internal-gelation sol–gel methods

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

Katalenich, Jeffrey A.; Kitchen, Brian B.; Pierson, Bruce D.

Cerium dioxide microspheres with uniform diameters between 65 – 211 µm were fabricated using internal gelation sol-gel methods. Although uniform microspheres are produced for nuclear fuel applications with diameters above 300 µm, sol-gel microspheres with diameters of 50 - 200 µm have historically been made by emulsion techniques and had poor size uniformity [1, 2]. An internal gelation, sol-gel apparatus was designed and constructed to accommodate the production of small, uniform microspheres whereby cerium-containing solutions were dispersed into flowing silicone oil and heated in a gelation column to initiate solidification [3, 4]. Problems with premature feed gelation and microsphere coalescencemore » were overcome by equipment modifications unique among known internal gelation setups. Microspheres were fabricated and sized in batches as a function of dispersing needle diameter and silicone oil flow rate in the two-fluid nozzle in order to determine the range of sizes possible and corresponding degree of monodispersity. Initial experiments with poor size uniformity were linked to microsphere coalescence in the gelation column prior to solidification as well as excessive flow rates for the cerium feed solution. Average diameter standard deviations as low as 2.23% were observed after optimization of flow rates and minimization of coalescence reactions.« less

Models for integrated pest control and their biological implications.

PubMed

Tang, Sanyi; Cheke, Robert A

2008-09-01

Successful integrated pest management (IPM) control programmes depend on many factors which include host-parasitoid ratios, starting densities, timings of parasitoid releases, dosages and timings of insecticide applications and levels of host-feeding and parasitism. Mathematical models can help us to clarify and predict the effects of such factors on the stability of host-parasitoid systems, which we illustrate here by extending the classical continuous and discrete host-parasitoid models to include an IPM control programme. The results indicate that one of three control methods can maintain the host level below the economic threshold (ET) in relation to different ET levels, initial densities of host and parasitoid populations and host-parasitoid ratios. The effects of host intrinsic growth rate and parasitoid searching efficiency on host mean outbreak period can be calculated numerically from the models presented. The instantaneous pest killing rate of an insecticide application is also estimated from the models. The results imply that the modelling methods described can help in the design of appropriate control strategies and assist management decision-making. The results also indicate that a high initial density of parasitoids (such as in inundative releases) and high parasitoid inter-generational survival rates will lead to more frequent host outbreaks and, therefore, greater economic damage. The biological implications of this counter intuitive result are discussed.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis

PubMed Central

Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole

2018-01-01

Background With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. Objective The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. Methods The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. Results A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). Conclusions The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. PMID:29792293

An Empirical Method Permitting Rapid Determination of the Area, Rate and Distribution of Water-Drop Impingement on an Airfoil of Arbitrary Section at Subsonic Speeds

NASA Technical Reports Server (NTRS)

Bergrun, N. R.

1951-01-01

An empirical method for the determination of the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The procedure represents an initial step toward the development of a method which is generally applicable in the design of thermal ice-prevention equipment for airplane wing and tail surfaces. Results given by the proposed empirical method are expected to be sufficiently accurate for the purpose of heated-wing design, and can be obtained from a few numerical computations once the velocity distribution over the airfoil has been determined. The empirical method presented for incompressible flow is based on results of extensive water-drop. trajectory computations for five airfoil cases which consisted of 15-percent-thick airfoils encompassing a moderate lift-coefficient range. The differential equations pertaining to the paths of the drops were solved by a differential analyzer. The method developed for incompressible flow is extended to the calculation of area and rate of impingement on straight wings in subsonic compressible flow to indicate the probable effects of compressibility for airfoils at low subsonic Mach numbers.

Bacterial meningitis in children under 15 years of age in Nepal.

PubMed

Shrestha, Rajani Ghaju; Tandukar, Sarmila; Ansari, Shamshul; Subedi, Akriti; Shrestha, Anisha; Poudel, Rekha; Adhikari, Nabaraj; Basnyat, Shital Raj; Sherchand, Jeevan Bahadur

2015-08-19

Bacterial meningitis in children is a life-threatening problem resulting in severe morbidity and mortality. For the prompt initiation of antibacterial therapy, rapid and reliable diagnostic methods are of utmost importance. Therefore, this study was designed to find out the rate of bacterial pathogens of meningitis from suspected cases by performing conventional methods and latex agglutination. A descriptive type of study was carried out from May 2012 to April 2013. Cerebrospinal fluid (CSF) specimens from 252 suspected cases of meningitis were subjected for Gram staining, bacterial culture and latex agglutination test. The identification of growth of bacteria was done following standard microbiological methods recommended by American Society for Microbiology. Antibiotic sensitivity testing was done by modified Kirby-Bauer disk diffusion method. From the total 252 suspected cases, 7.2 % bacterial meningitis was revealed by Gram staining and culture methods whereas latex agglutination method detected 5.6 %. Gram-negative organisms contributed the majority of the cases (72.2 %) with Haemophilus influenzae as the leading pathogen for meningitis. Overall, 33.3 % mortality rate was found. In conclusion, a significant rate of bacterial meningitis was found in this study prompting concern for national wide surveillance.

Role of HIV Infection Duration and CD4 Cell Level at Initiation of Combination Anti-Retroviral Therapy on Risk of Failure

PubMed Central

Lodi, Sara; Phillips, Andrew; Fidler, Sarah; Hawkins, David; Gilson, Richard; McLean, Ken; Fisher, Martin; Post, Frank; Johnson, Anne M.; Walker-Nthenda, Louise; Dunn, David; Porter, Kholoud

2013-01-01

Background The development of HIV drug resistance and subsequent virological failure are often cited as potential disadvantages of early cART initiation. However, their long-term probability is not known, and neither is the role of duration of infection at the time of initiation. Methods Patients enrolled in the UK Register of HIV seroconverters were followed-up from cART initiation to last HIV-RNA measurement. Through survival analysis we examined predictors of virologic failure (2HIV-RNA ≥400 c/l while on cART) including CD4 count and HIV duration at initiation. We also estimated the cumulative probabilities of failure and drug resistance (from the available HIV nucleotide sequences) for early initiators (cART within 12 months of seroconversion). Results Of 1075 starting cART at a median (IQR) CD4 count 272 (190,370) cells/mm3 and HIV duration 3 (1,6) years, virological failure occurred in 163 (15%). Higher CD4 count at initiation, but not HIV infection duration at cART initiation, was independently associated with lower risk of failure (p=0.033 and 0.592 respectively). Among 230 patients initiating cART early, 97 (42%) discontinued it after a median of 7 months; cumulative probabilities of resistance and failure by 8 years were 7% (95% CI 4,11) and 19% (13,25), respectively. Conclusion Although the rate of discontinuation of early cART in our cohort was high, the long-term rate of virological failure was low. Our data do not support early cART initiation being associated with increased risk of failure and drug resistance. PMID:24086588

Statistical Methods for Rapid Aerothermal Analysis and Design Technology: Validation

NASA Technical Reports Server (NTRS)

DePriest, Douglas; Morgan, Carolyn

2003-01-01

The cost and safety goals for NASA s next generation of reusable launch vehicle (RLV) will require that rapid high-fidelity aerothermodynamic design tools be used early in the design cycle. To meet these requirements, it is desirable to identify adequate statistical models that quantify and improve the accuracy, extend the applicability, and enable combined analyses using existing prediction tools. The initial research work focused on establishing suitable candidate models for these purposes. The second phase is focused on assessing the performance of these models to accurately predict the heat rate for a given candidate data set. This validation work compared models and methods that may be useful in predicting the heat rate.

Quantifying Hydrate Formation in Gas-rich Environments Using the Method of Characteristics

NASA Astrophysics Data System (ADS)

You, K.; Flemings, P. B.; DiCarlo, D. A.

2015-12-01

Methane hydrates hold a vast amount of methane globally, and have huge energy potential. Methane hydrates in gas-rich environments are the most promising production targets. We develop a one-dimensional analytical solution based on the method of characteristics to explore hydrate formation in such environments (Figure 1). Our solution shows that hydrate saturation is constant with time and space in a homogeneous system. Hydrate saturation is controlled by the initial thermodynamic condition of the system, and changed by the gas fractional flow. Hydrate saturation increases with the initial distance from the hydrate phase boundary. Different gas fractional flows behind the hydrate solidification front lead to different gas saturations at the hydrate solidification front. The higher the gas saturation at the front, the less the volume available to be filled by hydrate, and hence the lower the hydrate saturation. The gas fractional flow depends on the relative permeability curves, and the forces that drive the flow. Viscous forces (the drive for flow induced from liquid pressure gradient) dominate the flow, and hydrate saturation is independent on the gas supply rates and the flow directions at high gas supply rates. Hydrate saturation can be estimated as one minus the ratio of the initial to equilibrium salinity. Gravity forces (the drive for flow induced from the gravity) dominate the flow, and hydrate saturation depends on the flow rates and the flow directions at low gas supply rates. Hydrate saturation is highest for upward flow, and lowest for downward flow. Hydrate saturation decreases with the flow rate for upward flow, and increases with the flow rate for downward flow. This analytical solution illuminates how hydrate is formed by gas (methane, CO2, ethane, propane) flowing into brine-saturated sediments at both the laboratory and geological scales (Figure 1). It provides an approach to generalize the understanding of hydrate solidification in gas-rich environments, although complicated numerical models have been developed previously. Examples of gas expulsion into hydrate stability zones and the associated hydrate formation in both laboratory and geological scales, and CO2 sequestration into CO2-hydrates near the seafloor and under the permafrost will be presented.

Music therapy CD creation for initial pediatric radiation therapy: a mixed methods analysis.

PubMed

Barry, Philippa; O'Callaghan, Clare; Wheeler, Greg; Grocke, Denise

2010-01-01

A mixed methods research design was used to investigate the effects of a music therapy CD (MTCD) creation intervention on pediatric oncology patients' distress and coping during their first radiation therapy treatment. The music therapy method involved children creating a music CD using interactive computer-based music software, which was "remixed" by the music therapist-researcher to extend the musical material. Eleven pediatric radiation therapy outpatients aged 6 to 13 years were randomly assigned to either an experimental group, in which they could create a music CD prior to their initial treatment to listen to during radiation therapy, or to a standard care group. Quantitative and qualitative analyses generated multiple perceptions from the pediatric patients, parents, radiation therapy staff, and music therapist-researcher. Ratings of distress during initial radiation therapy treatment were low for all children. The comparison between the two groups found that 67% of the children in the standard care group used social withdrawal as a coping strategy, compared to 0% of the children in the music therapy group; this trend approached significance (p = 0.076). MTCD creation was a fun, engaging, and developmentally appropriate intervention for pediatric patients, which offered a positive experience and aided their use of effective coping strategies to meet the demands of their initial radiation therapy treatment.

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

Projecting insect voltinism under high and low greenhouse gas emission conditions

Treesearch

Shi Chen; Shelby J. Fleischer; Patrick C. Tobin; Michael C. Saunders

2011-01-01

We develop individual-based Monte Carlo methods to explore how climate change can alter insect voltinism under varying greenhouse gas emissions scenarios by using input distributions of diapause termination or spring emergence, development rate, and diapause initiation, linked to daily temperature and photoperiod. We show concurrence of these projections with a field...

New Structures and Approaches for Teacher Preparation: Do They Make a Difference in Teacher Retention?

ERIC Educational Resources Information Center

Harris, Steven A.; Camp, William E.; Adkison, Judith

Low initial employment rates and high attrition among teachers are factors recognized as major contributors to the national teacher shortage. This research compared the effectiveness of three teacher preparation methods used in Texas: alternative certification programs (ACPs), Centers for Professional Development and Technology (CPDTs), and…

40 CFR 63.1365 - Test methods and initial compliance procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... temperature of 760 °C, the design evaluation must document that these conditions exist. (ii) For a combustion... autoignition temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B...

40 CFR 63.1365 - Test methods and initial compliance procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... temperature of 760 °C, the design evaluation must document that these conditions exist. (ii) For a combustion... autoignition temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B...

40 CFR 63.1365 - Test methods and initial compliance procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... temperature of 760 °C, the design evaluation must document that these conditions exist. (ii) For a combustion... autoignition temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B...

40 CFR 63.1365 - Test methods and initial compliance procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... temperature of 760 °C, the design evaluation must document that these conditions exist. (ii) For a combustion... autoignition temperature of the organic HAP, must consider the vent stream flow rate, and must establish the design minimum and average temperature in the combustion zone and the combustion zone residence time. (B...

Effectiveness, Safety, and Pharmacokinetics of Quetiapine in Aggressive Children with Conduct Disorder

ERIC Educational Resources Information Center

Findling, Robert L.; Reed, Michael D.; O'Riordan, Mary Ann; Demeter, Christine A.; Stansbrey, Robert J.; McNamara, Nora K.

2006-01-01

Objective: To provide an initial description of the effectiveness and pharmacokinetics (PK) of quetiapine in aggressive children with conduct disorder (CD). Method: This 8-week, open-label outpatient trial, enrolled patients ages 6 to 12 years with CD. Outcome measures included the Rating of Aggression Against People and/or Property Scale…

A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

2002-01-01

Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

Initiation reactions in acetylene pyrolysis

DOE PAGES

Zador, Judit; Fellows, Madison D.; Miller, James A.

2017-05-10

In gas-phase combustion systems the interest in acetylene stems largely from its role in molecular weight growth processes. The consensus is that above 1500 K acetylene pyrolysis starts mainly with the homolytic fission of the C–H bond creating an ethynyl radical and an H atom. However, below ~1500 K this reaction is too slow to initiate the chain reaction. It has been hypothesized that instead of dissociation, self-reaction initiates this process. Nevertheless, rigorous theoretical or direct experimental evidence is lacking, to an extent that even the molecular mechanism is debated in the literature. In this work we use rigorous abmore » initio transition-state theory master equation methods to calculate pressure- and temperature-dependent rate coefficients for the association of two acetylene molecules and related reactions. We establish the role of vinylidene, the high-energy isomer of acetylene in this process, compare our results with available experimental data, and assess the competition between the first-order and second-order initiation steps. As a result, we also show the effect of the rapid isomerization among the participating wells and highlight the need for time-scale analysis when phenomenological rate coefficients are compared to observed time scales in certain experiments.« less

Breast-feeding initiation and exclusive breast-feeding in rural Vietnam.

PubMed

Duong, Dat V; Binns, Colin W; Lee, Andy H

2004-09-01

To investigate the initiation of breast-feeding and exclusive breast-feeding within the first week after delivery for women in rural Vietnam. An interviewer-administered survey was conducted on a sample of rural women who gave birth during August-October 2002. Quang Xuong District, Thanh Hoa Province of Vietnam. Four hundred and sixty-three women participated in the study, of whom 181 delivered at the district hospital (39.1%), 229 at a commune health centre (49.5%) and 53 at home attended by a traditional birth attendant (11.4%). Although the initiation and exclusive breast-feeding rates were relatively high at 98.3% and 83.6% respectively, the premature introduction of complementary food was a great concern. Logistic regression analysis showed that, together with socio-cultural determinants such as feeding preferences of the husband and maternal grandmother, feeding practices of friends, factors relating to delivery methods, delivery locations and health problems could influence the initiation rate and breast-feeding patterns. To promote breast-feeding practices of rural mothers, health education on breast-feeding should take into account local socio-cultural features in addition to improving the counselling skills of health workers.

A study of two statistical methods as applied to shuttle solid rocket booster expenditures

NASA Technical Reports Server (NTRS)

Perlmutter, M.; Huang, Y.; Graves, M.

1974-01-01

The state probability technique and the Monte Carlo technique are applied to finding shuttle solid rocket booster expenditure statistics. For a given attrition rate per launch, the probable number of boosters needed for a given mission of 440 launches is calculated. Several cases are considered, including the elimination of the booster after a maximum of 20 consecutive launches. Also considered is the case where the booster is composed of replaceable components with independent attrition rates. A simple cost analysis is carried out to indicate the number of boosters to build initially, depending on booster costs. Two statistical methods were applied in the analysis: (1) state probability method which consists of defining an appropriate state space for the outcome of the random trials, and (2) model simulation method or the Monte Carlo technique. It was found that the model simulation method was easier to formulate while the state probability method required less computing time and was more accurate.

The intensive and extensive margins of contraceptive use: comparing the effects of method choice and method initiation.

PubMed

Thomas, Adam; Karpilow, Quentin

2016-08-01

The risk of pregnancy is estimated to be 20 times as high among women who use oral contraception, and 90 times as high among condom users, as among women who use certain long-acting contraceptive methods. We explored the population-level implications of this variation in contraceptive efficacy. We used the FamilyScape 3.0 microsimulation model to study the effects on the nonmarital pregnancy rate of movements along two different margins of contraceptive behavior: the extensive margin, which captures decisions about whether to initiate use of any method of contraception among noncontraceptors; and the intensive margin, which captures the choice of methods among contraceptors. The model is populated with a nationally representative sample of 50,000 women who are of childbearing age. The impact on the number of nonmarital pregnancies would not be substantially different if noncontraceptors adopted long-acting methods than if they began using oral contraception. Moreover, the nonmarital pregnancy rate would be reduced by about twice as much if a subset of noncontraceptors began using condoms as if an equal number of pill users took up long-acting methods. The prevailing emphasis on long-acting contraception is somewhat misplaced. Policymakers and practitioners will have the largest effects on fertility outcomes if they can change the behavior of sexually active women who neglect to use birth control when they are not seeking pregnancy. Women's decisions about which methods to use are less impactful than their decisions about whether to use contraception at all. The policies that affect method choice are likely to differ from the policies that address the underlying motivations of noncontraceptors who are not seeking pregnancy. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of the initial configuration for user-object reputation systems

NASA Astrophysics Data System (ADS)

Wu, Ying-Ying; Guo, Qiang; Liu, Jian-Guo; Zhang, Yi-Cheng

2018-07-01

Identifying the user reputation accurately is significant for the online social systems. For different fair rating parameter q, by changing the parameter values α and β of the beta probability distribution (RBPD) for ranking online user reputation, we investigate the effect of the initial configuration of the RBPD method for the online user ranking performance. Experimental results for the Netflix and MovieLens data sets show that when the parameter q equals to 0.8 and 0.9, the accuracy value AUC would increase about 4.5% and 3.5% for the Netflix data set, while the AUC value increases about 1.5% for the MovieLens data set when the parameter q is 0.9. Furthermore, we investigate the evolution characteristics of the AUC value for different α and β, and find that as the rating records increase, the AUC value increases about 0.2 and 0.16 for the Netflix and MovieLens data sets, indicating that online users' reputations will increase as they rate more and more objects.

Routine vs extended outpatient EEG for the detection of interictal epileptiform discharges

PubMed Central

Britton, Jeffrey W.; Rajasekaran, Vijayalakshmi; Fabris, Rachel R.; Cherian, Perumpillichira J.; Kelly-Williams, Kristen M.; So, Elson L.; Nickels, Katherine C.; Wong-Kisiel, Lily C.; Lagerlund, Terrence D.; Cascino, Gregory D.; Worrell, Gregory A.; Wirrell, Elaine C.

2016-01-01

Objective: To compare the yield of epileptiform abnormalities on 30-minute recordings with those greater than 45 minutes. Methods: We performed a prospective observational cross-sectional study of all outpatient routine EEGs comparing the rate of interictal epileptiform discharges (IEDs) and clinical events during the initial 30 minutes (routine) with those occurring in the remaining 30–60 minutes (extended). A relative increase of 10% was considered clinically significant. Results: EEGs from 1,803 patients were included; overall EEG duration was 59.4 minutes (SD ±6.5). Of 426 patients with IEDs at any time during the EEG, 81 (19.1%, 95% confidence interval 15.6–23) occurred only after the initial 30 minutes. The rate of late IEDs was not associated with age, indication, IED type, or sleep deprivation. Longer recording times also increased event capture rate by approximately 30%. Conclusions: The yield of IED and event detection is increased in extended outpatient EEGs compared to 30-minute studies. PMID:26984946

The preparation of Fe2O3-ZSM-5 catalysts by metal-organic chemical vapour deposition method for catalytic wet peroxide oxidation of m-cresol.

PubMed

Yang, Yi; Zhang, Huiping; Yan, Ying

2018-03-01

Fe 2 O 3 -ZSM-5 catalysts (0.6 wt% Fe load) prepared by metal-organic chemical vapour deposition (MOCVD) method were evaluated in the catalytic wet peroxide oxidation (CWPO) of m -cresol in a batch reactor. The catalysts have a good iron dispersion and small iron crystalline size, and exhibit high stability during reaction. In addition, the kinetics of the reaction were studied and the initial oxidation rate equation was given. Catalysts were first characterized by N 2 adsorption-desorption isotherms, scanning electronic microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results show that extra-framework Fe 3+ species (presenting in the form of Fe 2 O 3 ) are successfully loaded on ZSM-5 supports by MOCVD method. Performances of catalysts were tested and effects of different temperature, stirring rate, catalyst amount on hydrogen peroxide, m -cresol, total organic carbon (TOC) conversion and Fe leaching concentration were studied. Results reveal that catalytic activity increased with higher temperature, faster stirring rate and larger catalyst amount. In all circumstances, m -cresol conversion could reach 99% in 0.5-2.5 h, and the highest TOC removal (80.5%) is obtained after 3 h under conditions of 60°C, 400 r.p.m. and catalyst amount of 2.5 g l -1 . The iron-leaching concentrations are less than 1.1 mg l -1 under all conditions. The initial oxidation rate equation [Formula: see text] is obtained for m -cresol degradation with Fe 2 O 3 -ZSM-5 catalysts.

Method for estimating spatially variable seepage loss and hydraulic conductivity in intermittent and ephemeral streams

USGS Publications Warehouse

Niswonger, R.G.; Prudic, David E.; Fogg, G.E.; Stonestrom, David A.; Buckland, E.M.

2008-01-01

A method is presented for estimating seepage loss and streambed hydraulic conductivity along intermittent and ephemeral streams using streamflow front velocities in initially dry channels. The method uses the kinematic wave equation for routing streamflow in channels coupled to Philip's equation for infiltration. The coupled model considers variations in seepage loss both across and along the channel. Water redistribution in the unsaturated zone is also represented in the model. Sensitivity of the streamflow front velocity to parameters used for calculating seepage loss and for routing streamflow shows that the streambed hydraulic conductivity has the greatest sensitivity for moderate to large seepage loss rates. Channel roughness, geometry, and slope are most important for low seepage loss rates; however, streambed hydraulic conductivity is still important for values greater than 0.008 m/d. Two example applications are presented to demonstrate the utility of the method.

Results of Ponseti Brasil Program: Multicentric Study in 1621 Feet: Preliminary Results.

PubMed

Nogueira, Monica P; Queiroz, Ana C D B F; Melanda, Alessandro G; Tedesco, Ana P; Brandão, Antonio L G; Beling, Claudio; Violante, Francisco H; Brandão, Gilberto F; Ferreira, Laura F A; Brambila, Leandro S; Leite, Leopoldina M; Zabeu, Jose L; Kim, Jung H; Fernandes, Kalyana E; Arima, Marcia A S; Aguilar, Maria D P Q; Farias Filho, Orlando C D; Oliveira Filho, Oscar B D A; Pinho, Solange D S; Moulin, Paulo; Volpi, Reinaldo; Fox, Mark; Greenwald, Miles F; Lyle, Brandon; Morcuende, Jose A

The Ponseti method has been shown to be the most effective treatment for congenital clubfoot. The current challenge is to establish sustainable national clubfoot treatment programs that utilize the Ponseti method and integrate it within a nation's governmental health system. The Brazilian Ponseti Program (Programa Ponseti Brasil) has increased awareness of the utility of the Ponseti method and has trained >500 Brazilian orthopaedic surgeons in it. A group of 18 of those surgeons had been able to reproduce the Ponseti clubfoot treatment, and compiled their initial results through structured spreadsheet. The study compiled 1040 patients for a total of 1621 feet. The average follow-up time was 2.3 years with an average correction time of approximately 3 months. Patients required an average of 6.40 casts to achieve correction. This study demonstrates that good initial correction rates are reproducible after training; from 1040 patients only 1.4% required a posteromedial release. Level IV.

Crack orientation and depth estimation in a low-pressure turbine disc using a phased array ultrasonic transducer and an artificial neural network.

PubMed

Yang, Xiaoxia; Chen, Shili; Jin, Shijiu; Chang, Wenshuang

2013-09-13

Stress corrosion cracks (SCC) in low-pressure steam turbine discs are serious hidden dangers to production safety in the power plants, and knowing the orientation and depth of the initial cracks is essential for the evaluation of the crack growth rate, propagation direction and working life of the turbine disc. In this paper, a method based on phased array ultrasonic transducer and artificial neural network (ANN), is proposed to estimate both the depth and orientation of initial cracks in the turbine discs. Echo signals from cracks with different depths and orientations were collected by a phased array ultrasonic transducer, and the feature vectors were extracted by wavelet packet, fractal technology and peak amplitude methods. The radial basis function (RBF) neural network was investigated and used in this application. The final results demonstrated that the method presented was efficient in crack estimation tasks.

Crack Orientation and Depth Estimation in a Low-Pressure Turbine Disc Using a Phased Array Ultrasonic Transducer and an Artificial Neural Network

PubMed Central

Yang, Xiaoxia; Chen, Shili; Jin, Shijiu; Chang, Wenshuang

2013-01-01

Stress corrosion cracks (SCC) in low-pressure steam turbine discs are serious hidden dangers to production safety in the power plants, and knowing the orientation and depth of the initial cracks is essential for the evaluation of the crack growth rate, propagation direction and working life of the turbine disc. In this paper, a method based on phased array ultrasonic transducer and artificial neural network (ANN), is proposed to estimate both the depth and orientation of initial cracks in the turbine discs. Echo signals from cracks with different depths and orientations were collected by a phased array ultrasonic transducer, and the feature vectors were extracted by wavelet packet, fractal technology and peak amplitude methods. The radial basis function (RBF) neural network was investigated and used in this application. The final results demonstrated that the method presented was efficient in crack estimation tasks. PMID:24064602

Quantification of the transient mass flow rate in a simplex swirl injector

NASA Astrophysics Data System (ADS)

Khil, Taeock; Kim, Sunghyuk; Cho, Seongho; Yoon, Youngbin

2009-07-01

When a heat release and acoustic pressure fluctuations are generated in a combustor by irregular and local combustions, these fluctuations affect the mass flow rate of the propellants injected through the injectors. In addition, variations of the mass flow rate caused by these fluctuations bring about irregular combustion, which is associated with combustion instability, so it is very important to identify a mass variation through the pressure fluctuation on the injector and to investigate its transfer function. Therefore, quantification of the variation of the mass flow rate generated in a simplex swirl injector via the injection pressure fluctuation was the subject of an initial study. To acquire the transient mass flow rate in the orifice with time, the axial velocity of flows and the liquid film thickness in the orifice were measured. The axial velocity was acquired through a theoretical approach after measuring the pressure in the orifice. In an effort to understand the flow area in the orifice, the liquid film thickness was measured by an electric conductance method. In the results, the mass flow rate calculated from the axial velocity and the liquid film thickness measured by the electric conductance method in the orifice was in good agreement with the mass flow rate acquired by the direct measuring method in a small error range within 1% in the steady state and within 4% for the average mass flow rate in a pulsated state. Also, the amplitude (gain) of the mass flow rate acquired by the proposed direct measuring method was confirmed using the PLLIF technique in the low pressure fluctuation frequency ranges with an error under 6%. This study shows that our proposed method can be used to measure the mass flow rate not only in the steady state but also in the unsteady state (or the pulsated state). Moreover, this method shows very high accuracy based on the experimental results.

A sequential bioequivalence design with a potential ethical advantage.

PubMed

Fuglsang, Anders

2014-07-01

This paper introduces a two-stage approach for evaluation of bioequivalence, where, in contrast to the designs of Diane Potvin and co-workers, two stages are mandatory regardless of the data obtained at stage 1. The approach is derived from Potvin's method C. It is shown that under circumstances with relatively high variability and relatively low initial sample size, this method has an advantage over Potvin's approaches in terms of sample sizes while controlling type I error rates at or below 5% with a minute occasional trade-off in power. Ethically and economically, the method may thus be an attractive alternative to the Potvin designs. It is also shown that when using the method introduced here, average total sample sizes are rather independent of initial sample size. Finally, it is shown that when a futility rule in terms of sample size for stage 2 is incorporated into this method, i.e., when a second stage can be abolished due to sample size considerations, there is often an advantage in terms of power or sample size as compared to the previously published methods.

Combined Uncertainty and A-Posteriori Error Bound Estimates for CFD Calculations: Theory and Implementation

NASA Technical Reports Server (NTRS)

Barth, Timothy J.

2014-01-01

Simulation codes often utilize finite-dimensional approximation resulting in numerical error. Some examples include, numerical methods utilizing grids and finite-dimensional basis functions, particle methods using a finite number of particles. These same simulation codes also often contain sources of uncertainty, for example, uncertain parameters and fields associated with the imposition of initial and boundary data,uncertain physical model parameters such as chemical reaction rates, mixture model parameters, material property parameters, etc.

Optimization of gas chromatographic method for the enantioseparation of arylpropionic non-steroidal anti-inflammatory drug methyl esters.

PubMed

Petrović, Marinko; Debeljak, Zeljko; Blazević, Nikola

2005-09-15

The gas chromatography (GC) method for enantioseparation of well-known non-steroidal anti-inflammatory drugs ibuprofen, fenoprofen and ketoprofen methyl esters mixture was developed. Best enantioseparation was performed on capillary column with heptakis-(2,3-di-O-methyl-6-O-t-butyldimethyl-silyl)-beta-cyclodextrin stationary phase and hydrogen used as a carrier gas. Initial temperature, program rate and carrier pressure were optimized to obtain best resolution between enantiomers.

An empirical method for estimating travel times for wet volcanic mass flows

USGS Publications Warehouse

Pierson, Thomas C.

1998-01-01

Travel times for wet volcanic mass flows (debris avalanches and lahars) can be forecast as a function of distance from source when the approximate flow rate (peak discharge near the source) can be estimated beforehand. The near-source flow rate is primarily a function of initial flow volume, which should be possible to estimate to an order of magnitude on the basis of geologic, geomorphic, and hydrologic factors at a particular volcano. Least-squares best fits to plots of flow-front travel time as a function of distance from source provide predictive second-degree polynomial equations with high coefficients of determination for four broad size classes of flow based on near-source flow rate: extremely large flows (>1 000 000 m3/s), very large flows (10 000–1 000 000 m3/s), large flows (1000–10 000 m3/s), and moderate flows (100–1000 m3/s). A strong nonlinear correlation that exists between initial total flow volume and flow rate for "instantaneously" generated debris flows can be used to estimate near-source flow rates in advance. Differences in geomorphic controlling factors among different flows in the data sets have relatively little effect on the strong nonlinear correlations between travel time and distance from source. Differences in flow type may be important, especially for extremely large flows, but this could not be evaluated here. At a given distance away from a volcano, travel times can vary by approximately an order of magnitude depending on flow rate. The method can provide emergency-management officials a means for estimating time windows for evacuation of communities located in hazard zones downstream from potentially hazardous volcanoes.

Theory and simulation of the time-dependent rate coefficients of diffusion-influenced reactions.

PubMed Central

Zhou, H X; Szabo, A

1996-01-01

A general formalism is developed for calculating the time-dependent rate coefficient k(t) of an irreversible diffusion-influenced reaction. This formalism allows one to treat most factors that affect k(t), including rotational Brownian motion and conformational gating of reactant molecules and orientation constraint for product formation. At long times k(t) is shown to have the asymptotic expansion k(infinity)[1 + k(infinity) (pie Dt)-1/2 /4 pie D + ...], where D is the relative translational diffusion constant. An approximate analytical method for calculating k(t) is presented. This is based on the approximation that the probability density of the reactant pair in the reactive region keeps the equilibrium distribution but with a decreasing amplitude. The rate coefficient then is determined by the Green function in the absence of chemical reaction. Within the framework of this approximation, two general relations are obtained. The first relation allows the rate coefficient for an arbitrary amplitude of the reactivity to be found if the rate coefficient for one amplitude of the reactivity is known. The second relation allows the rate coefficient in the presence of conformational gating to be found from that in the absence of conformational gating. The ratio k(t)/k(0) is shown to be the survival probability of the reactant pair at time t starting from an initial distribution that is localized in the reactive region. This relation forms the basis of the calculation of k(t) through Brownian dynamics simulations. Two simulation procedures involving the propagation of nonreactive trajectories initiated only from the reactive region are described and illustrated on a model system. Both analytical and simulation results demonstrate the accuracy of the equilibrium-distribution approximation method. PMID:8913584

An efficient global energy optimization approach for robust 3D plane segmentation of point clouds

NASA Astrophysics Data System (ADS)

Dong, Zhen; Yang, Bisheng; Hu, Pingbo; Scherer, Sebastian

2018-03-01

Automatic 3D plane segmentation is necessary for many applications including point cloud registration, building information model (BIM) reconstruction, simultaneous localization and mapping (SLAM), and point cloud compression. However, most of the existing 3D plane segmentation methods still suffer from low precision and recall, and inaccurate and incomplete boundaries, especially for low-quality point clouds collected by RGB-D sensors. To overcome these challenges, this paper formulates the plane segmentation problem as a global energy optimization because it is robust to high levels of noise and clutter. First, the proposed method divides the raw point cloud into multiscale supervoxels, and considers planar supervoxels and individual points corresponding to nonplanar supervoxels as basic units. Then, an efficient hybrid region growing algorithm is utilized to generate initial plane set by incrementally merging adjacent basic units with similar features. Next, the initial plane set is further enriched and refined in a mutually reinforcing manner under the framework of global energy optimization. Finally, the performances of the proposed method are evaluated with respect to six metrics (i.e., plane precision, plane recall, under-segmentation rate, over-segmentation rate, boundary precision, and boundary recall) on two benchmark datasets. Comprehensive experiments demonstrate that the proposed method obtained good performances both in high-quality TLS point clouds (i.e., http://SEMANTIC3D.NET)

Growth rate measurement in free jet experiments

NASA Astrophysics Data System (ADS)

Charpentier, Jean-Baptiste; Renoult, Marie-Charlotte; Crumeyrolle, Olivier; Mutabazi, Innocent

2017-07-01

An experimental method was developed to measure the growth rate of the capillary instability for free liquid jets. The method uses a standard shadow-graph imaging technique to visualize a jet, produced by extruding a liquid through a circular orifice, and a statistical analysis of the entire jet. The analysis relies on the computation of the standard deviation of a set of jet profiles, obtained in the same experimental conditions. The principle and robustness of the method are illustrated with a set of emulated jet profiles. The method is also applied to free falling jet experiments conducted for various Weber numbers and two low-viscosity solutions: a Newtonian and a viscoelastic one. Growth rate measurements are found in good agreement with linear stability theory in the Rayleigh's regime, as expected from previous studies. In addition, the standard deviation curve is used to obtain an indirect measurement of the initial perturbation amplitude and to identify beads on a string structure on the jet. This last result serves to demonstrate the capability of the present technique to explore in the future the dynamics of viscoelastic liquid jets.

The development and evaluation of ultrasound for the treatment of bacterial suspensions. A study of frequency, power and sonication time on cultured Bacillus species.

PubMed

Joyce, E; Phull, S S; Lorimer, J P; Mason, T J

2003-10-01

Some species of bacteria produce colonies and spores which agglomerate in spherical clusters (Bacillus subtilis) and this serves as a protection for the organisms inside against biocidal attack. Flocs of fine particles e.g. clay can entrap bacteria which can also protect them against the biocides. It is because of problems such as these that alternative methods of disinfecting water are under active investigation. One such method is the use of power ultrasound, either alone or in combination with other methods. Ultrasound is able to inactivate bacteria and deagglomerate bacterial clusters or flocs through a number of physical, mechanical and chemical effects arising from acoustic cavitation. The aim of this study was to investigate the effect of power ultrasound at different powers and frequencies on Bacillus subtilis. Viable plate count techniques were used as a measure of microbial activity. Results showed a significant increase in percent kill for Bacillus species with increasing duration of exposure and intensity of ultrasound in the low-kilohertz range (20 and 38 kHz). Results obtained at two higher frequencies (512 and 850 kHz) indicated a significant increase in bacteria count suggesting declumping. In assessing the bacterial kill with time under different sonication regimes three types of behaviour were characterized: High power ultrasound (lower frequencies) in low volumes of bacterial suspension results in a continuous reduction in bacterial cell numbers i.e. the kill rate predominates. High power ultrasound (lower frequencies) in larger volumes results in an initial rise in cell numbers suggesting declumping of the bacteria but this initial rise then falls as the declumping finishes and the kill rate becomes more important. Low intensity ultrasound (higher frequencies) gives an initial rise in cell numbers as a result of declumping. The kill rate is low and so there is no significant subsequent decrease in bacterial cell numbers.

Control of Growth Rate by Initial Substrate Concentration at Values Below Maximum Rate

PubMed Central

Gaudy, Anthony F.; Obayashi, Alan; Gaudy, Elizabeth T.

1971-01-01

The hyperbolic relationship between specific growth rate, μ, and substrate concentration, proposed by Monod and used since as the basis for the theory of steady-state growth in continuous-flow systems, was tested experimentally in batch cultures. Use of a Flavobacterium sp. exhibiting a high saturation constant for growth in glucose minimal medium allowed direct measurement of growth rate and substrate concentration throughout the growth cycle in medium containing a rate-limiting initial concentration of glucose. Specific growth rates were also measured for a wide range of initial glucose concentrations. A plot of specific growth rate versus initial substrate concentration was found to fit the hyperbolic equation. However, the instantaneous relationship between specific growth rate and substrate concentration during growth, which is stated by the equation, was not observed. Well defined exponential growth phases were developed at initial substrate concentrations below that required for support of the maximum exponential growth rate and a constant doubling time was maintained until 50% of the substrate had been used. It is suggested that the external substrate concentration initially present “sets” the specific growth rate by establishing a steady-state internal concentration of substrate, possibly through control of the number of permeation sites. PMID:5137579

A New Highly Sensitive Method to Assess Respiration Rates and Kinetics of Natural Planktonic Communities by Use of the Switchable Trace Oxygen Sensor and Reduced Oxygen Concentrations

PubMed Central

Tiano, Laura; Garcia-Robledo, Emilio; Revsbech, Niels Peter

2014-01-01

Oxygen respiration rates in pelagic environments are often difficult to quantify as the resolutions of our methods for O2 concentration determination are marginal for observing significant decreases during bottle incubations of less than 24 hours. Here we present the assessment of a new highly sensitive method, that combine Switchable Trace Oxygen (STOX) sensors and all-glass bottle incubations, where the O2 concentration was artificially lowered. The detection limit of respiration rate by this method is inversely proportional to the O2 concentration, down to <2 nmol L−1 h−1 for water with an initial O2 concentration of 500 nmol L−1. The method was tested in Danish coastal waters and in oceanic hypoxic waters. It proved to give precise measurements also with low oxygen consumption rates (∼7 nmol L−1 h−1), and to significantly decrease the time required for incubations (≤14 hours) compared to traditional methods. This method provides continuous real time measurements, allowing for a number of diverse possibilities, such as modeling the rate of oxygen decrease to obtain kinetic parameters. Our data revealed apparent half-saturation concentrations (Km values) one order of magnitude lower than previously reported for marine bacteria, varying between 66 and 234 nmol L−1 O2. Km values vary between different microbial planktonic communities, but our data show that it is possible to measure reliable respiration rates at concentrations ∼0.5–1 µmol L−1 O2 that are comparable to the ones measured at full air saturation. PMID:25127458

Study on Corrosion-induced Crack Initiation and Propagation of Sustaining Loaded RCbeams

NASA Astrophysics Data System (ADS)

Zhong, X. P.; Li, Y.; Yuan, C. B.; Yang, Z.; Chen, Y.

2018-05-01

For 13 pieces of reinforced concrete beams with HRB500 steel bars under long-term sustained loads, at time of corrosion-induced initial crack of concrete, and corrosion-induced crack widths of 0.3mm and 1mm, corrosion of steel bars and time-varying behavior of corrosion-induced crack width were studied by the ECWD (Electro-osmosis - constant Current – Wet and Dry cycles) accelerated corrosion method. The results show that when cover thickness was between 30 and 50mm,corrosion rates of steel bars were between 0.8% and 1.7% at time of corrosion-induced crack, and decreased with increasing concrete cover thickness; when corrosion-induced crack width was 0.3mm, the corrosion rate decreased with increasing steel bar diameter, and increased with increasing cover thickness; its corrosion rate varied between 0.98% and 4.54%; when corrosion-induced crack width reached 1mm, corrosion rate of steel bars was between 4% and 4.5%; when corrosion rate of steel bars was within 5%, the maximum and average corrosion-induced crack and corrosion rate of steel bars had a good linear relationship. The calculation model predicting the maximum and average width of corrosion-induced crack is given in this paper.

An evaluation of long-term preservation methods for brown bear (Ursus arctos) faecal DNA samples

USGS Publications Warehouse

Murphy, M.A.; Waits, L.P.; Kendall, K.C.; Wasser, S.K.; Higbee, J.A.; Bogden, R.

2002-01-01

Relatively few large-scale faecal DNA studies have been initiated due to difficulties in amplifying low quality and quantity DNA template. To improve brown bear faecal DNA PCR amplification success rates and to determine post collection sample longevity, five preservation methods were evaluated: 90% ethanol, DETs buffer, silica-dried, oven-dried stored at room temperature, and oven-dried stored at -20??C. Preservation effectiveness was evaluated for 50 faecal samples by PCR amplification of a mitochondrial DNA (mtDNA) locus (???146 bp) and a nuclear DNA (nDNA) locus (???200 bp) at time points of one week, one month, three months and six months. Preservation method and storage time significantly impacted mtDNA and nDNA amplification success rates. For mtDNA, all preservation methods had ??? 75% success at one week, but storage time had a significant impact on the effectiveness of the silica preservation method. Ethanol preserved samples had the highest success rates for both mtDNA (86.5%) and nDNA (84%). Nuclear DNA amplification success rates ranged from 26-88%, and storage time had a significant impact on all methods but ethanol. Preservation method and storage time should be important considerations for researchers planning projects utilizing faecal DNA. We recommend preservation of faecal samples in 90% ethanol when feasible, although when collecting in remote field conditions or for both DNA and hormone assays a dry collection method may be advantageous.

Longitudinal Cognitive Trajectories of Women Veterans from the Women’s Health Initiative Memory Study

PubMed Central

Padula, Claudia B.; Weitlauf, Julie C.; Rosen, Allyson C.; Reiber, Gayle; Cochrane, Barbara B.; Naughton, Michelle J.; Li, Wenjun; Rissling, Michelle; Yaffe, Kristine; Hunt, Julie R.; Stefanick, Marcia L.; Goldstein, Mary K.; Espeland, Mark A.

2016-01-01

Purpose of the Study: A comparison of longitudinal global cognitive functioning in women Veteran and non-Veteran participants in the Women’s Health Initiative (WHI). Design and Methods: We studied 7,330 women aged 65–79 at baseline who participated in the WHI Hormone Therapy Trial and its ancillary Memory Study (WHIMS). Global cognitive functioning (Modified Mini-Mental State Examination [3MSE]) in Veterans (n = 279) and non-Veterans (n = 7,051) was compared at baseline and annually for 8 years using generalized linear modeling methods. Results: Compared with non-Veterans, Veteran women were older, more likely to be Caucasian, unmarried, and had higher rates of educational and occupational attainment. Results of unadjusted baseline analyses suggest 3MSE scores were similar between groups. Longitudinal analyses, adjusted for age, education, ethnicity, and WHI trial assignment revealed differences in the rate of cognitive decline between groups over time, such that scores decreased more in Veterans relative to non-Veterans. This relative difference was more pronounced among Veterans who were older, had higher educational/occupational attainment and greater baseline prevalence of cardiovascular risk factors (e.g., smoking) and cardiovascular disease (e.g., angina, stroke). Implications: Veteran status was associated with higher prevalence of protective factors that may have helped initially preserve cognitive functioning. However, findings ultimately revealed more pronounced cognitive decline among Veteran relative to non-Veteran participants, likely suggesting the presence of risks that may impact neuropathology and the effects of which were initially masked by Veterans’ greater cognitive reserve. PMID:26615021

Influence of a counteradvertising media campaign on initiation of smoking: the Florida "truth" campaign.

PubMed Central

Sly, D F; Hopkins, R S; Trapido, E; Ray, S

2001-01-01

OBJECTIVES: The purpose of this study was to assess the short-term effects of television advertisements from the Florida "truth" campaign on rates of smoking initiation. METHODS: A follow-up survey of young people aged 12 to 17 years (n = 1820) interviewed during the first 6 months of the advertising campaign was conducted. Logistic regression analyses were used to estimate the independent effects of the campaign on smoking initiation while other factors were controlled for. RESULTS: Youths scoring at intermediate and high levels on a media effect index were less likely to initiate smoking than youths who could not confirm awareness of television advertisements. Adjusted odds ratios between the media index and measures of initiation were similar within categories of age, sex, susceptibility, and whether a parent smoked. CONCLUSIONS: Exposure to the "truth" media campaign lowered the risk of youth smoking initiation. However, the analysis did not demonstrate that all such media programs will be effective. PMID:11211631

The Childhood Obesity Declines Project: Implications for Research and Evaluation Approaches.

PubMed

Young-Hyman, Deborah; Morris, Kathryn; Kettel Khan, Laura; Dawkins-Lyn, Nicola; Dooyema, Carrie; Harris, Carole; Jernigan, Jan; Ottley, Phyllis; Kauh, Tina

2018-03-01

Childhood obesity remains prevalent and is increasing in some disadvantaged populations. Numerous research, policy and community initiatives are undertaken to impact this pandemic. Understudied are natural experiments. The need to learn from these efforts is paramount. Resulting evidence may not be readily available to inform future research, community initiatives, and policy development/implementation. We discuss the implications of using an adaptation of the Systematic Screening and Assessment (SSA) method to evaluate the Childhood Obesity Declines (COBD) project. The project examined successful initiatives, programs and policies in four diverse communities which were concurrent with significant declines in child obesity. In the context of other research designs and evaluation schemas, rationale for use of SSA is presented. Evidence generated by this method is highlighted and guidance suggested for evaluation of future studies of community-based childhood obesity prevention initiatives. Support for the role of stakeholder collaboratives, in particular the National Collaborative on Childhood Obesity Research, as a synergistic vehicle to accelerate research on childhood obesity is discussed. SSA mapped active processes and provided contextual understanding of multi-level/component simultaneous efforts to reduce rates of childhood obesity in community settings. Initiatives, programs and policies were not necessarily coordinated. And although direct attribution of intervention/initiative/policy components could not be made, the what, by who, how, to whom was temporally associated with statistically significant reductions in childhood obesity. SSA provides evidence for context and processes which are not often evaluated in other data analytic methods. SSA provides an additional tool to layer with other evaluation approaches.

Deriving Childhood Temperament Measures from Emotion-eliciting Behavioral Episodes: Scale Construction and Initial Validation

PubMed Central

Gagne, Jeffrey R.; Van Hulle, Carol A.; Aksan, Nazan; Essex, Marilyn J.; Goldsmith, H. Hill

2010-01-01

The authors describe the development and initial validation of a home-based version of the Laboratory Temperament Assessment Battery (Lab-TAB), which was designed to assess childhood temperament using a comprehensive series of emotion-eliciting behavioral episodes. This paper provides researchers with general guidelines for assessing specific behaviors using the Lab-TAB and for forming behavioral composites that correspond to commonly researched temperament dimensions. We used mother ratings and independent post-visit observer ratings to provide validity evidence in a community sample of 4.5 year-old children. 12 Lab-TAB behavioral episodes were employed, yielding 24 within-episode temperament components that collapsed into 9 higher-level composites (Anger, Sadness, Fear, Shyness, Positive Expression, Approach, Active Engagement, Persistence, and Inhibitory Control). These dimensions of temperament are similar to those found in questionnaire-based assessments. Correlations among the 9 composites were low to moderate, suggesting relative independence. As expected, agreement between Lab-TAB measures and post-visit observer ratings was stronger than agreement between the Lab-TAB and mother questionnaire. However, for Active Engagement and Shyness, mother ratings did predict child behavior in the Lab-TAB quite well. Findings demonstrate the feasibility of emotion-eliciting temperament assessment methodologies, suggest appropriate methods for data aggregation into trait-level constructs, and set some expectations for associations between Lab-TAB dimensions and the degree of cross-method convergence between the Lab-TAB and other commonly used temperament assessments. PMID:21480723

A Nonlinear Least Squares Approach to Time of Death Estimation Via Body Cooling.

PubMed

Rodrigo, Marianito R

2016-01-01

The problem of time of death (TOD) estimation by body cooling is revisited by proposing a nonlinear least squares approach that takes as input a series of temperature readings only. Using a reformulation of the Marshall-Hoare double exponential formula and a technique for reducing the dimension of the state space, an error function that depends on the two cooling rates is constructed, with the aim of minimizing this function. Standard nonlinear optimization methods that are used to minimize the bivariate error function require an initial guess for these unknown rates. Hence, a systematic procedure based on the given temperature data is also proposed to determine an initial estimate for the rates. Then, an explicit formula for the TOD is given. Results of numerical simulations using both theoretical and experimental data are presented, both yielding reasonable estimates. The proposed procedure does not require knowledge of the temperature at death nor the body mass. In fact, the method allows the estimation of the temperature at death once the cooling rates and the TOD have been calculated. The procedure requires at least three temperature readings, although more measured readings could improve the estimates. With the aid of computerized recording and thermocouple detectors, temperature readings spaced 10-15 min apart, for example, can be taken. The formulas can be straightforwardly programmed and installed on a hand-held device for field use. © 2015 American Academy of Forensic Sciences.

Developing a policy guidance for financing dental care in Iran using the RAND Appropriateness Method.

PubMed

Jadidfard, M P; Yazdani, S; Khoshnevisan, M H

2013-12-01

This study aimed to provide recommendations on health care financing with special emphasis on dental care. The RAND Appropriateness Method was employed to obtain the collective opinion of a multidisciplinary panel of experts on a set of recommendation statements regarding Iranian dental care financing. An initial set of recommendations were identified from a literature review. Panel members, selected purposively and by peer nomination, each rated the appropriateness and necessity of the recommendations in a structured process of two rounds. Each recommendation was classified as inappropriate, uncertain, appropriate but not necessary, or appropriate and necessary according to the median rating score and the level of disagreement among the panellists. Of 28 initial recommendations, 25 were agreed on as appropriate, of which 22 were considered as necessary. Altogether, these recommendations provide a holistic picture of an oral health system's financing in three domains: revenue collection, pooling of revenues and purchasing of dental services. The policy guidance recommendations are intended to provide the Iranian oral health authorities with an evidence-base for financing dental care. The recommendations may be transferrable, at least in part, particularly to developing countries with similar hybrid health system structures. Finally, the method used to develop the recommendations can serve as a model for use elsewhere.

Factors affecting initial disability allowance rates for the Disability Insurance and Supplemental Security Income programs: the role of the demographic and diagnostic composition of applicants and local labor market conditions.

PubMed

Rupp, Kalman

2012-01-01

Various factors outside the control of decision makers may affect the rate at which disability applications are allowed or denied during the initial step of eligibility determination in the Social Security Disability Insurance (DI) and Supplemental Security Income (SSI) programs. In this article, using individual-level data on applications, I estimate the role of three important factors--the demographic characteristics of applicants, the diagnostic mix of applicants, and the local unemployment rate--in affecting the probability of an initial allowance and state allowance rates. I use a random sample of initial determinations from 1993 through 2008 and a fixed-effects multiple regression framework. The empirical results show that the demographic and diagnostic characteristics of applicants and the local unemployment rate substantially affect the initial allowance rate. An increase in the local unemployment rate tends to be associated with a decrease in the initial allowance rate. This negative relationship holds for adult DI and SSI applicants and for SSI childhood applicants.

Predicting areas of sustainable error growth in quasigeostrophic flows using perturbation alignment properties

NASA Astrophysics Data System (ADS)

Rivière, G.; Hua, B. L.

2004-10-01

A new perturbation initialization method is used to quantify error growth due to inaccuracies of the forecast model initial conditions in a quasigeostrophic box ocean model describing a wind-driven double gyre circulation. This method is based on recent analytical results on Lagrangian alignment dynamics of the perturbation velocity vector in quasigeostrophic flows. More specifically, it consists in initializing a unique perturbation from the sole knowledge of the control flow properties at the initial time of the forecast and whose velocity vector orientation satisfies a Lagrangian equilibrium criterion. This Alignment-based Initialization method is hereafter denoted as the AI method.In terms of spatial distribution of the errors, we have compared favorably the AI error forecast with the mean error obtained with a Monte-Carlo ensemble prediction. It is shown that the AI forecast is on average as efficient as the error forecast initialized with the leading singular vector for the palenstrophy norm, and significantly more efficient than that for total energy and enstrophy norms. Furthermore, a more precise examination shows that the AI forecast is systematically relevant for all control flows whereas the palenstrophy singular vector forecast leads sometimes to very good scores and sometimes to very bad ones.A principal component analysis at the final time of the forecast shows that the AI mode spatial structure is comparable to that of the first eigenvector of the error covariance matrix for a "bred mode" ensemble. Furthermore, the kinetic energy of the AI mode grows at the same constant rate as that of the "bred modes" from the initial time to the final time of the forecast and is therefore characterized by a sustained phase of error growth. In this sense, the AI mode based on Lagrangian dynamics of the perturbation velocity orientation provides a rationale of the "bred mode" behavior.

Stepwise kinetic equilibrium models of quantitative polymerase chain reaction.

PubMed

Cobbs, Gary

2012-08-16

Numerous models for use in interpreting quantitative PCR (qPCR) data are present in recent literature. The most commonly used models assume the amplification in qPCR is exponential and fit an exponential model with a constant rate of increase to a select part of the curve. Kinetic theory may be used to model the annealing phase and does not assume constant efficiency of amplification. Mechanistic models describing the annealing phase with kinetic theory offer the most potential for accurate interpretation of qPCR data. Even so, they have not been thoroughly investigated and are rarely used for interpretation of qPCR data. New results for kinetic modeling of qPCR are presented. Two models are presented in which the efficiency of amplification is based on equilibrium solutions for the annealing phase of the qPCR process. Model 1 assumes annealing of complementary targets strands and annealing of target and primers are both reversible reactions and reach a dynamic equilibrium. Model 2 assumes all annealing reactions are nonreversible and equilibrium is static. Both models include the effect of primer concentration during the annealing phase. Analytic formulae are given for the equilibrium values of all single and double stranded molecules at the end of the annealing step. The equilibrium values are then used in a stepwise method to describe the whole qPCR process. Rate constants of kinetic models are the same for solutions that are identical except for possibly having different initial target concentrations. Analysis of qPCR curves from such solutions are thus analyzed by simultaneous non-linear curve fitting with the same rate constant values applying to all curves and each curve having a unique value for initial target concentration. The models were fit to two data sets for which the true initial target concentrations are known. Both models give better fit to observed qPCR data than other kinetic models present in the literature. They also give better estimates of initial target concentration. Model 1 was found to be slightly more robust than model 2 giving better estimates of initial target concentration when estimation of parameters was done for qPCR curves with very different initial target concentration. Both models may be used to estimate the initial absolute concentration of target sequence when a standard curve is not available. It is argued that the kinetic approach to modeling and interpreting quantitative PCR data has the potential to give more precise estimates of the true initial target concentrations than other methods currently used for analysis of qPCR data. The two models presented here give a unified model of the qPCR process in that they explain the shape of the qPCR curve for a wide variety of initial target concentrations.

CHAP-2 heat-transfer analysis of the Fort St. Vrain reactor core

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

Kotas, J.F.; Stroh, K.R.

1983-01-01

The Los Alamos National Laboratory is developing the Composite High-Temperature Gas-Cooled Reactor Analysis Program (CHAP) to provide advanced best-estimate predictions of postulated accidents in gas-cooled reactor plants. The CHAP-2 reactor-core model uses the finite-element method to initialize a two-dimensional temperature map of the Fort St. Vrain (FSV) core and its top and bottom reflectors. The code generates a finite-element mesh, initializes noding and boundary conditions, and solves the nonlinear Laplace heat equation using temperature-dependent thermal conductivities, variable coolant-channel-convection heat-transfer coefficients, and specified internal fuel and moderator heat-generation rates. This paper discusses this method and analyzes an FSV reactor-core accident thatmore » simulates a control-rod withdrawal at full power.« less

Optimal interpolation and the Kalman filter. [for analysis of numerical weather predictions

NASA Technical Reports Server (NTRS)

Cohn, S.; Isaacson, E.; Ghil, M.

1981-01-01

The estimation theory of stochastic-dynamic systems is described and used in a numerical study of optimal interpolation. The general form of data assimilation methods is reviewed. The Kalman-Bucy, KB filter, and optimal interpolation (OI) filters are examined for effectiveness in performance as gain matrices using a one-dimensional form of the shallow-water equations. Control runs in the numerical analyses were performed for a ten-day forecast in concert with the OI method. The effects of optimality, initialization, and assimilation were studied. It was found that correct initialization is necessary in order to localize errors, especially near boundary points. Also, the use of small forecast error growth rates over data-sparse areas was determined to offset inaccurate modeling of correlation functions near boundaries.

Breast-feeding intention, initiation and duration among Hong Kong Chinese women: a prospective longitudinal study.

PubMed

Wang, Wenru; Lau, Ying; Chow, Aloysius; Chan, Kin Sin

2014-06-01

to (1) estimate the breast-feeding intention, initiation and duration rate; (2) identify the reasons to initiate and wean breast feeding and (3) explore predictors of breast-feeding duration. a prospective longitudinal study antenatal clinics of five regional hospitals from four clusters in Hong Kong a population-based sample of 2098 women in the second trimester of pregnancy was recruited with a systematic sampling method. three different sets of self-administered questionnaires were used to measure the breast-feeding intention, initiation and duration, demographic, socio-economic, obstetric, complications of pregnancy and intrapartum variables at three time points. Reasons for initiating and weaning breast feeding, the formal and informal supportive resources of participants during breast feeding were collated at the third time points. the rates of artificial feeding and breast feeding were 41.1% and 58.9%, whereas breast-feeding intention and initiation rates were 85.3% and 67.0%, respectively. The breast-feeding duration rates were 11.1%, 10.3%, 10.7% and 26.7%, for the 'within <1 week', '1-3 weeks', '>3-6 weeks' and '>6 weeks' groups. The common reasons for initiating breast feeding were that breast feeding is beneficial for both the baby (89.8%) and mother (39.7%). Reasons for weaning breast feeding were insufficient breast milk (32.7%), tiredness and fatigue (39.7%) and return to work (29.6%). Partner, relatives and nurse midwives were important supportive resource during breast feeding. Ordinal logistic regression analysis identified five predictive factors of breast-feeding duration. Participants who were working part-time or were housewives (p=0.037), had monthly family income of

A dose assessment method for arbitrary geometries with virtual reality in the nuclear facilities decommissioning

NASA Astrophysics Data System (ADS)

Chao, Nan; Liu, Yong-kuo; Xia, Hong; Ayodeji, Abiodun; Bai, Lu

2018-03-01

During the decommissioning of nuclear facilities, a large number of cutting and demolition activities are performed, which results in a frequent change in the structure and produce many irregular objects. In order to assess dose rates during the cutting and demolition process, a flexible dose assessment method for arbitrary geometries and radiation sources was proposed based on virtual reality technology and Point-Kernel method. The initial geometry is designed with the three-dimensional computer-aided design tools. An approximate model is built automatically in the process of geometric modeling via three procedures namely: space division, rough modeling of the body and fine modeling of the surface, all in combination with collision detection of virtual reality technology. Then point kernels are generated by sampling within the approximate model, and when the material and radiometric attributes are inputted, dose rates can be calculated with the Point-Kernel method. To account for radiation scattering effects, buildup factors are calculated with the Geometric-Progression formula in the fitting function. The effectiveness and accuracy of the proposed method was verified by means of simulations using different geometries and the dose rate results were compared with that derived from CIDEC code, MCNP code and experimental measurements.

Detonation Initiation of Heterogeneous Melt-Cast High Explosives

NASA Astrophysics Data System (ADS)

Chuzeville, Vincent; Baudin, Gerard; Lefrancois, Alexandre; Boulanger, Remi; Catoire, Laurent

2015-06-01

The melt-cast explosives' shock initiation mechanisms are less investigated than pressed and cast-cured ones. If the existence of hot-spots is widely recognized, their formation mechanism is not yet established. We study here two melt-cast explosives, NTO-TNT 60:40 and RDX-TNT 60:40 in order to establish a relation between the microstructure and the reaction rate using a two-phase model based on a ZND approach. Such a model requires the reaction rate, the equations of state of the unreacted phase and of the detonation products and an interaction model between the two phases to describe the reaction zone thermodynamics. The reaction rate law can be written in a factorized form including the number of initiation sites, the explosive's deflagration velocity around hot spots and a function depending on gas volume fraction produced by the deflagration front propagation. The deflagration velocity mainly depends on pressure and is determined from pop-plot tests using the hypothesis of the single curve build-up. This hypothesis has been verified for our two melt-cast explosives. The function depending on gas volume fraction is deduced from microstructural observations and from an analogy with the solid nucleation and growth theory. It has been established for deflagration fronts growing from grain's surface and a given initial grain size distribution. The model requires only a few parameters, calibrated thanks to an inversion method. A good agreement is obtained between experiments and numerical simulations.

The economic and clinical burden of early versus late initiation of celecoxib among patients with osteoarthritis

PubMed Central

Shelbaya, Ahmed; Solem, Caitlyn T; Walker, Chris; Wan, Yin; Johnson, Courtney; Cappelleri, Joseph C

2018-01-01

Objective This study aimed to evaluate the characteristics associated with early versus late initiation of celecoxib treatment after osteoarthritis (OA) diagnosis and whether economic and safety outcomes differ between patients with early versus late initiation of celecoxib. Methods Adults (≥18 years) with a confirmed OA diagnosis (International Classification of Diseases, 9th Edition, Clinical Modifications code: 715.XX), ≥12 months of continuous pre- and post-index enrollment, and ≥1 post-index claim for celecoxib were included from the MarketScan® Commercial Claims and Encounter Database (2009–2013). Index date was defined as initial OA diagnosis. Patients were categorized as initiating celecoxib early (within 6 months of index date) or late (≥6 months after index date). Logistic regressions were used to assess characteristics associated with early versus late celecoxib initiation. Key outcomes included health care resource utilization (HCRU) and costs post-index, and adverse event incidence post-celecoxib initiation. Unadjusted and adjusted comparisons (using generalized linear models with a gamma distribution for costs and Poisson distribution for event and resource utilization) were made between early and late celecoxib initiators. Results Of the 62,434 OA patients identified, 27,402 were early and 35,032 were late initiators. Post-index hospital admissions and length of stay did not differ statistically between early versus late initiators after controlling for pre-index event rates and covariates, but early patients had significantly fewer outpatient (incidence rate ratio [IRR]: 0.96; 95% confidence interval [CI]: 0.95, 0.97) and emergency room visits (IRR: 0.89; 95% CI: 0.84, 0.95). After adjustment for key covariates, early initiators (versus late initiators) had lower all-cause (US$12,909 versus US$13,781, P<0.001) and OA-related (US$4,988 versus US$5,178, P=0.015) costs per person-year. Early initiators had no statistically significant difference in the incidence of post-celecoxib cardiovascular (IRR: 0.92; 95% CI: 0.73, 1.14), gastrointestinal (IRR: 1.25; 95% CI: 0.81, 1.92), or renal (IRR: 1.19; 95% CI: 0.65, 2.18) events, controlling for pre-index event rates and covariates when compared to late initiators. Conclusion In this real-world cohort, patients initiated on celecoxib early (versus late) had significantly lower costs and HCRU; this may warrant consideration when making treatment decisions for OA patients. PMID:29670383

Strain energy release rate analysis of delamination in a tapered laminate subjected to tension load

NASA Technical Reports Server (NTRS)

Salpekar, S. A.; Raju, I. S.; Obrien, T. K.

1990-01-01

A tapered composite laminate subjected to tension load was analyzed using the finite-element method. The glass/epoxy laminate has a (+ or - 45)sub 3 group of plies dropped in three distinct steps, each 20 ply-thicknesses apart, thus forming a taper angle of 5.71 degrees. Steep gradients of interlaminar normal and shear stress on a potential delamination interface suggest the existence of stress singularities at the points of material and geometric discontinuities created by the internal plydrops. The delamination was assumed to initiate at the thin end of the taper on a -45/+45 interface and the delamination growth was simulated in both directions, i.e., along the taper and into the thin region. The strain-energy-release rate for a delamination growing into the thin laminate consisted predominantly of mode I (opening) component. For a delamination growing along the tapered region, the strain-energy-release rate was initially all mode I, but the proportion of mode I decreased with increase in delamination size until eventually total G was all mode II. The total G for both delamination tips increased with increase in delamination size, indicating that a delamination initiating at the end of the taper will grow unstably along the taper and into the thin laminate simultaneously.

Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration

USGS Publications Warehouse

Heilweil, Victor M.; Benoit, Jerome; Healy, Richard W.

2015-01-01

Spreading-basin methods have resulted in more than 130 million cubic meters of recharge to the unconfined Navajo Sandstone of southern Utah in the past decade, but infiltration rates have slowed in recent years because of reduced hydraulic gradients and clogging. Trench infiltration is a promising alternative technique for increasing recharge and minimizing evaporation. This paper uses a variably saturated flow model to further investigate the relative importance of the following variables on rates of trench infiltration to unconfined aquifers: saturated hydraulic conductivity, trench spacing and dimensions, initial water-table depth, alternate wet/dry periods, and number of parallel trenches. Modeling results showed (1) increased infiltration with higher hydraulic conductivity, deeper initial water tables, and larger spacing between parallel trenches, (2) deeper or wider trenches do not substantially increase infiltration, (3) alternating wet/dry periods result in less overall infiltration than keeping the trenches continuously full, and (4) larger numbers of parallel trenches within a fixed area increases infiltration but with a diminishing effect as trench spacing becomes tighter. An empirical equation for estimating expected trench infiltration rates as a function of hydraulic conductivity and initial water-table depth was derived and can be used for evaluating feasibility of trench infiltration in other hydrogeologic settings

Evaluation of a Small-Crack Monitoring System

NASA Technical Reports Server (NTRS)

Newman, John A.; Johnston, William M.

2010-01-01

A new system has been developed to obtain fatigue crack growth rate data from a series of images acquired during fatigue testing of specimens containing small surface cracks that initiate at highly-polished notches. The primary benefit associated with replica-based crack growth rate data methods is preserving a record of the crack configuration during the life of the specimen. Additionally, this system has the benefits of both reducing time and labor, and not requiring introduction of surface replica media into the crack. Fatigue crack growth rate data obtained using this new system are found to be in good agreement with similar results obtained from surface replicas.

Epidemiological analysis of factors influencing rate of progress in Echinococcus granulosus control in New Zealand.

PubMed Central

Burridge, M. J.; Schwabe, C. W.

1977-01-01

The factors influencing the rate of progress in Echinococcus granulosus control in New Zealand were analysed by hydatid control area using stepwise multiple regression techniques. The results indicated that the rate of progress was related positively to initial E. granulosus prevalence in dogs and the efficiency with which local authorities implemented national control policy, and negatively to the Maori proportion in the local population and the number of dogs per owner. Problems in analysis of the New Zealand data are discussed and improved methods of monitoring progress in hydatid disease control programmes are described. Images Fig. 1 PMID:265340

Session 1: Public health nutrition. Breast-feeding practices in Ireland.

PubMed

Tarrant, Roslyn C; Kearney, John M

2008-11-01

Breast-feeding is the superior infant feeding method from birth, with research consistently demonstrating its numerous short- and long-term health benefits for both mother and infant. As a global recommendation the WHO advises that mothers should exclusively breast-feed for the first 6-months of life, thus delaying the introduction of solids during this time. Historically, Irish breast-feeding initiation rates have remained strikingly low in comparison with international data and there has been little improvement in breast-feeding duration rates. There is wide geographical variation in terms of breast-feeding initiation both internationally and in Ireland. Some of these differences in breast-feeding rates may be associated with differing socio-economic characteristics. A recent cross-sectional prospective study of 561 pregnant women attending a Dublin hospital and followed from the antenatal period to 6 months post partum has found that 47% of the Irish-national mothers initiated breast-feeding, while only 24% were still offering 'any' breast milk to their infants at 6 weeks. Mothers' positive antenatal feeding intention to breast-feed is indicated as one of the most important independent determinants of initiation and 'any' breast-feeding at 6 weeks, suggesting that the antenatal period should be targeted as an effective time to influence and affect mothers' attitudes and beliefs pertaining to breast-feeding. These results suggest that the 'cultural' barrier towards breast-feeding appears to still prevail in Ireland and consequently an environment that enables women to breast-feed is far from being achieved. Undoubtedly, a shift towards a more positive and accepting breast-feeding culture is required if national breast-feeding rates are to improve.

Sandia fracture challenge 2: Sandia California's modeling approach

DOE PAGES

Karlson, Kyle N.; James W. Foulk, III; Brown, Arthur A.; ...

2016-03-09

The second Sandia Fracture Challenge illustrates that predicting the ductile fracture of Ti-6Al-4V subjected to moderate and elevated rates of loading requires thermomechanical coupling, elasto-thermo-poro-viscoplastic constitutive models with the physics of anisotropy and regularized numerical methods for crack initiation and propagation. We detail our initial approach with an emphasis on iterative calibration and systematically increasing complexity to accommodate anisotropy in the context of an isotropic material model. Blind predictions illustrate strengths and weaknesses of our initial approach. We then revisit our findings to illustrate the importance of including anisotropy in the failure process. Furthermore, mesh-independent solutions of continuum damage modelsmore » having both isotropic and anisotropic yields surfaces are obtained through nonlocality and localization elements.« less

Determining next steps in a hand hygiene improvement initiative by examining variation in hand hygiene compliance rates.

PubMed

Homa, Karen; Kirkland, Kathryn B

2011-01-01

Health care worker hand hygiene (HH) is a major quality and safety concern since poor hand hygiene has been linked with hospital associated infections. Dartmouth-Hitchcock Medical Center has been involved in a 4-year initiative to improve hand hygiene. In 2006, HH compliance occurred 41% of the time and by 2009, it had improved to 91%. We wanted to understand some of the unexplained variability in HH to help determine where to target more specific strategies. To help determine where some of the variability in HH compliance rates occurred, an analysis of means chart was used to determine whether role type of the health care worker and hospital areas had significantly different HH rates compared with the overall HH rate. The overall HH rate between March 2008 and December 2009 was 87%. There was a wide and significant variation between the 16 groups of 2 types of health care workers in 8 hospital areas from the lowest rate of 64% to a high of 96%. Analysis of means revealed significant differences in HH rates relative to the type of worker and hospital areas. Although the method does not inform the organization of what type of intervention will work where and why, it allows high and low performing groups to be identified, so that organizations can learn from them to generate and test theories.

40 CFR 60.700 - Applicability and designation of affected facility.

Code of Federal Regulations, 2012 CFR

2012-07-01

... compounds (TOC) (less methane and ethane) in the vent stream less than 300 ppmv as measured by Method 18 or... maximum production rate at which the affected facility will be operated, or 180 days after the initial... limits in these standards are expressed in terms of TOC, measured as TOC less methane and ethane. This...

40 CFR 60.700 - Applicability and designation of affected facility.

Code of Federal Regulations, 2011 CFR

2011-07-01

... compounds (TOC) (less methane and ethane) in the vent stream less than 300 ppmv as measured by Method 18 or... maximum production rate at which the affected facility will be operated, or 180 days after the initial... limits in these standards are expressed in terms of TOC, measured as TOC less methane and ethane. This...

A Logistic Regression Analysis of Student Experience Factors for the Enhancement of Developmental Post-Secondary Retention Initiatives

ERIC Educational Resources Information Center

Shenkle, Michael Thomas

2017-01-01

In response to stagnant undergraduate completion rates and growing demands for post-secondary accountability, institutions are actively pursuing effective, broadly applicable methods for promoting student success. One notable scarcity in existing research is found in the tailoring of broad academic interventions to better meet the specific needs…

Lessons Learned: How Early College High Schools Offer a Pathway for High School Reform

ERIC Educational Resources Information Center

Kaniuka, Theodore Stefan; Vickers, Melinda

2010-01-01

In 2002, Early College High Schools Initiative became a reality across the United States for students and educators looking for ways to improve student graduation rates, college attendance, and overall student achievement. This mixed method case study found that (a) the early college high school environment supported the academic success of…

FECAL INDICATOR BACTERIA MEASUREMENTS BY QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) ANALYSIS IN FRESH ARCHIVED DNA EXTRACT OF WATER SAMPLE FILTRATES

EPA Science Inventory

The U.S. EPA has initiated a new recreational water study to evaluate the correlation between illness rates in swimmers and Enterococcus concentrations determined by the mEI agar membrane filter (MF) method and several new technologies including QPCR analysis. Results of this stu...

Information content of incubation experiments for inverse estimation of pools in the Rothamsted carbon model: a Bayesian perspective

NASA Astrophysics Data System (ADS)

Scharnagl, B.; Vrugt, J. A.; Vereecken, H.; Herbst, M.

2010-02-01

A major drawback of current soil organic carbon (SOC) models is that their conceptually defined pools do not necessarily correspond to measurable SOC fractions in real practice. This not only impairs our ability to rigorously evaluate SOC models but also makes it difficult to derive accurate initial states of the individual carbon pools. In this study, we tested the feasibility of inverse modelling for estimating pools in the Rothamsted carbon model (ROTHC) using mineralization rates observed during incubation experiments. This inverse approach may provide an alternative to existing SOC fractionation methods. To illustrate our approach, we used a time series of synthetically generated mineralization rates using the ROTHC model. We adopted a Bayesian approach using the recently developed DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm to infer probability density functions of the various carbon pools at the start of incubation. The Kullback-Leibler divergence was used to quantify the information content of the mineralization rate data. Our results indicate that measured mineralization rates generally provided sufficient information to reliably estimate all carbon pools in the ROTHC model. The incubation time necessary to appropriately constrain all pools was about 900 days. The use of prior information on microbial biomass carbon significantly reduced the uncertainty of the initial carbon pools, decreasing the required incubation time to about 600 days. Simultaneous estimation of initial carbon pools and decomposition rate constants significantly increased the uncertainty of the carbon pools. This effect was most pronounced for the intermediate and slow pools. Altogether, our results demonstrate that it is particularly difficult to derive reasonable estimates of the humified organic matter pool and the inert organic matter pool from inverse modelling of mineralization rates observed during incubation experiments.

Change in brain and lesion volumes after CEE therapies

PubMed Central

Espeland, Mark A.; Hogan, Patricia E.; Resnick, Susan M.; Bryan, R. Nick; Robinson, Jennifer G.; Goveas, Joseph S.; Davatzikos, Christos; Kuller, Lewis H.; Williamson, Jeff D.; Bushnell, Cheryl D.; Shumaker, Sally A.

2014-01-01

Objectives: To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen–based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. Methods: A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Results: Total brain volume decreased an average of 3.22 cm3/y in the active arm and 3.07 cm3/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm3/y (p = 0.88). Conclusions: Conjugated equine estrogen–based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings. PMID:24384646

Reirradiation of Large-Volume Recurrent Glioma With Pulsed Reduced-Dose-Rate Radiotherapy

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

Adkison, Jarrod B.; Tome, Wolfgang; Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI

2011-03-01

Purpose: Pulsed reduced-dose-rate radiotherapy (PRDR) is a reirradiation technique that reduces the effective dose rate and increases the treatment time, allowing sublethal damage repair during irradiation. Patients and Methods: A total of 103 patients with recurrent glioma underwent reirradiation using PRDR (86 considered to have Grade 4 at PRDR). PRDR was delivered using a series of 0.2-Gy pulses at 3-min intervals, creating an apparent dose rate of 0.0667 Gy/min to a median dose of 50 Gy (range, 20-60) delivered in 1.8-2.0-Gy fractions. The mean treatment volume was 403.5 {+-} 189.4 cm{sup 3} according to T{sub 2}-weighted magnetic resonance imaging andmore » a 2-cm margin. Results: For the initial or upgraded Grade 4 cohort (n = 86), the median interval from the first irradiation to PRDR was 14 months. Patients undergoing PRDR within 14 months of the first irradiation (n = 43) had a median survival of 21 weeks. Those treated {>=}14 months after radiotherapy had a median survival of 28 weeks (n = 43; p = 0.004 and HR = 1.82 with a 95% CI ranging from 1.25 to 3.10). These data compared favorably to historical data sets, because only 16% of the patients were treated at first relapse (with 46% treated at the second relapse, 32% at the third or fourth relapse, and 4% at the fourth or fifth relapse). The median survival since diagnosis and retreatment was 6.3 years and 11.4 months for low-grade, 4.1 years and 5.6 months for Grade 3, and 1.6 years and 5.1 months for Grade 4 tumors, respectively, according to the initial histologic findings. Multivariate analysis revealed age at the initial diagnosis, initial low-grade disease, and Karnofsky performance score of {>=}80 to be significant predictors of survival after initiation of PRDR. Conclusion: PRDR allowed for safe retreatment of larger volumes to high doses with palliative benefit.« less

"It's almost expected": rural Australian Aboriginal women's reflections on smoking initiation and maintenance: a qualitative study

PubMed Central

2011-01-01

Background Despite declining smoking rates among the general Australian population, rates among Indigenous Australians remain high, with 47% of the Indigenous population reporting daily smoking - twice that of other Australians. Among women, smoking rates are highest in younger age groups, with more than half of Aboriginal women smoking during pregnancy. A lack of research focused on understanding the social context of smoking by Aboriginal women in rural Australia limits our ability to reduce these rates. This study aimed to explore the factors contributing to smoking initiation among rural Aboriginal women and girls and the social context within which smoking behaviour occurs. Methods We conducted three focus groups with 14 Aboriginal women and service providers and 22 individual interviews with Aboriginal women from four rural communities to explore their perceptions of the factors contributing to smoking initiation among Aboriginal girls. Results Four inter-related factors were considered important to understanding the social context in which girls start smoking: colonisation and the introduction of tobacco; normalization of smoking within separate Aboriginal social networks; disadvantage and stressful lives; and the importance of maintaining relationships within extended family and community networks. Within this context, young girls use smoking to attain status and as a way of asserting Aboriginal identity and group membership, a way of belonging, not of rebelling. Family and social structures were seen as providing strong support, but limited the capacity of parents to influence children not to smoke. Marginalization was perceived to contribute to limited aspirations and opportunities, leading to pleasure-seeking in the present rather than having goals for the future. Conclusions The results support the importance of addressing contextual factors in any strategies aimed at preventing smoking initiation or supporting cessation among Aboriginal girls and women. It is critical to acknowledge Aboriginal identity and culture as a source of empowerment; and to recognise the role of persistent marginalization in contributing to the high prevalence and initiation of smoking. PMID:22152218

Suicide rates in European OECD nations converged during the period 1990-2010.

PubMed

Bremberg, Sven G

2017-05-01

The aim of this study was to investigate, with multiple regression analyses, the effect of selected characteristics on the rate of decrease of suicide rates in 21 OECD (Organisation for Economic Co-operation and Development) nations over the period 1990-2010, with initial levels of suicide rates taken into account. The rate of decrease seems mainly (83%) to be determined by the initial suicide rates in 1990. In nations with relatively high initial rates, the rates decreased faster. The suicide rates also converged. The study indicates that beta convergence alone explained most of the cross-national variations.

Development of the Expert System Domain Advisor and Analysis Tool

DTIC Science & Technology

1991-09-01

analysis. Typical of the current methods in use at this time is the " tarot metric". This method defines a decision rule whose output is whether to go...B - TAROT METRIC B. ::TTRODUCTION The system chart of ESEM, Figure 1, shows the following three risk-based decision points: i. At prolect initiation...34 decisions. B-I 201 PRELIMINARY T" B-I. Evaluais Factan for ES Deyelopsineg FACTORS POSSIBLE VALUE RATINGS TAROT metric (overall suitability) Poor, Fair

Ionizing radiation post-curing of objects produced by stereolithography and other methods

DOEpatents

Howell, David H.; Eberle, Claude C.; Janke, Christopher J.

2000-01-01

An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

Method for nondestructive fuel assay of laser fusion targets

DOEpatents

Farnum, Eugene H.; Fries, R. Jay

1976-01-01

A method for nondestructively determining the deuterium and tritium content of laser fusion targets by counting the x rays produced by the interaction of tritium beta particles with the walls of the microballoons used to contain the deuterium and tritium gas mixture under high pressure. The x rays provide a direct measure of the tritium content and a means for calculating the deuterium content using the initial known D-T ratio and the known deuterium and tritium diffusion rates.

Implementation of a vibrationally linked chemical reaction model for DSMC

NASA Technical Reports Server (NTRS)

Carlson, A. B.; Bird, Graeme A.

1994-01-01

A new procedure closely linking dissociation and exchange reactions in air to the vibrational levels of the diatomic molecules has been implemented in both one- and two-dimensional versions of Direct Simulation Monte Carlo (DSMC) programs. The previous modeling of chemical reactions with DSMC was based on the continuum reaction rates for the various possible reactions. The new method is more closely related to the actual physics of dissociation and is more appropriate to the particle nature of DSMC. Two cases are presented: the relaxation to equilibrium of undissociated air initially at 10,000 K, and the axisymmetric calculation of shuttle forebody heating during reentry at 92.35 km and 7500 m/s. Although reaction rates are not used in determining the dissociations or exchange reactions, the new method produces rates which agree astonishingly well with the published rates derived from experiment. The results for gas properties and surface properties also agree well with the results produced by earlier DSMC models, equilibrium air calculations, and experiment.

Reoperations after tricuspid valve repair: re-repair versus replacement

PubMed Central

Hwang, Ho Young; Kim, Kyung-Hwan; Kim, Ki-Bong

2016-01-01

Background Data demonstrating results of reoperation after initial tricuspid valve repair are scarce. We evaluated outcomes of tricuspid reoperations after tricuspid valve repair and compared the results of tricuspid re-repair with those of tricuspid valve replacement (TVR). Methods From 1994 to 2012, 53 patients (56±15 years, male:female =14:39) underwent tricuspid reoperations due to recurrent tricuspid regurgitation (TR) after initial repair. Twenty-two patients underwent tricuspid re-repair (TAP group) and 31 patients underwent TVR (TVR group). Results Early mortality occurred in 6 patients (11%). Early mortality and incidence of postoperative complications were similar between the 2 groups. There were 14 cases of late mortality including 9 cardiac deaths. Five- and 10-year free from cardiac death rates were 82% and 67%, respectively, without any intergroup difference. Recurrent TR (> moderate) developed in 6 TAP group patients and structural valve deterioration occurred in 1 TVR group patient (P=0.002). Isolated tricuspid valve surgery (P=0.044) and presence of atrial fibrillation during the follow-up (P=0.051) were associated with recurrent TR after re-repair. However, the overall tricuspid valve-related event rates were similar between the 2 groups with 5- and 10-year rates of 61% and 41%, respectively. Conclusions Tricuspid valve reoperation after initial repair resulted in high rates of operative mortality and complications. Long-term event-free rate was similar regardless of the type of surgery. However, great care might be needed when performing re-repair in patients with atrial fibrillation and those who had isolated tricuspid valve disease due to high recurrence of TR after re-repair. PMID:26904221

Research on the water-entry attitude of a submersible aircraft.

PubMed

Xu, BaoWei; Li, YongLi; Feng, JinFu; Hu, JunHua; Qi, Duo; Yang, Jian

2016-01-01

The water entry of a submersible aircraft, which is transient, highly coupled, and nonlinear, is complicated. After analyzing the mechanics of this process, the change rate of every variable is considered. A dynamic model is build and employed to study vehicle attitude and overturn phenomenon during water entry. Experiments are carried out and a method to organize experiment data is proposed. The accuracy of the method is confirmed by comparing the results of simulation of dynamic model and experiment under the same condition. Based on the analysis of the experiment and simulation, the initial attack angle and angular velocity largely influence the water entry of vehicle. Simulations of water entry with different initial and angular velocities are completed, followed by an analysis, and the motion law of vehicle is obtained. To solve the problem of vehicle stability and control during water entry, an approach is proposed by which the vehicle sails with a zero attack angle after entering water by controlling the initial angular velocity. With the dynamic model and optimization research algorithm, calculation is performed, and the optimal initial angular velocity of water-entry is obtained. The outcome of simulations confirms that the effectiveness of the propose approach by which the initial water-entry angular velocity is controlled.

Increased Risk of Non-Fatal Myocardial Infarction Following Testosterone Therapy Prescription in Men

PubMed Central

Finkle, William D.; Greenland, Sander; Ridgeway, Gregory K.; Adams, John L.; Frasco, Melissa A.; Cook, Michael B.; Fraumeni, Joseph F.; Hoover, Robert N.

2014-01-01

Background An association between testosterone therapy (TT) and cardiovascular disease has been reported and TT use is increasing rapidly. Methods We conducted a cohort study of the risk of acute non-fatal myocardial infarction (MI) following an initial TT prescription (N = 55,593) in a large health-care database. We compared the incidence rate of MI in the 90 days following the initial prescription (post-prescription interval) with the rate in the one year prior to the initial prescription (pre-prescription interval) (post/pre). We also compared post/pre rates in a cohort of men prescribed phosphodiesterase type 5 inhibitors (PDE5I; sildenafil or tadalafil, N = 167,279), and compared TT prescription post/pre rates with the PDE5I post/pre rates, adjusting for potential confounders using doubly robust estimation. Results In all subjects, the post/pre-prescription rate ratio (RR) for TT prescription was 1.36 (1.03, 1.81). In men aged 65 years and older, the RR was 2.19 (1.27, 3.77) for TT prescription and 1.15 (0.83, 1.59) for PDE5I, and the ratio of the rate ratios (RRR) for TT prescription relative to PDE5I was 1.90 (1.04, 3.49). The RR for TT prescription increased with age from 0.95 (0.54, 1.67) for men under age 55 years to 3.43 (1.54, 7.56) for those aged ≥75 years (ptrend = 0.03), while no trend was seen for PDE5I (ptrend = 0.18). In men under age 65 years, excess risk was confined to those with a prior history of heart disease, with RRs of 2.90 (1.49, 5.62) for TT prescription and 1.40 (0.91, 2.14) for PDE5I, and a RRR of 2.07 (1.05, 4.11). Discussion In older men, and in younger men with pre-existing diagnosed heart disease, the risk of MI following initiation of TT prescription is substantially increased. PMID:24489673

[Death rate by malnutrition in children under the age of five, Colombia].

PubMed

Quiroga, Edwin Fernando

2012-01-01

Much higher mortalities occur in children under five in developing countries with high poverty rates compared with developed countries. Causes of death are related to perinatal conditions, measles, HIV/AIDS, diarrhea, respiratory diseases and others. Throughout the world, malnutrition has been identified as the underlying cause of approximately half of these deaths. Death rate due to malnutrition was described using an adjusted method that takes into account the difficulties of identifying malnutrition as a direct cause of death. A descriptive study included analysis of the International Classification of Diseases (ICD-10) vital statistics from 2003-2007. Death rates were estimated, a method of analysis of multiple causes was applied for infectious diseases, along with calculations of death probabilities. Malnutrition was associated with infectious diseases. The frequency of infectious disease as a direct cause of death was almost seven times higher in cases with the antecedent of malnutrition. When adjusted death rate values were used, the initial value increased nearly five times. The probability of death after the adjustment for inadequate classification increased approximately four times. The Analysis of Multiple Causes Method was established as an effective method in analyzing malnutrition and infectious diesease mortality in Colombia. Malnutrition may be a direct underlying cause of death in one of eight deaths in children <1 year old and one of three deaths in 1-4-year-olds.

Maximum initial growth-rate of strong-shock-driven Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Abarzhi, Snezhana I.; Bhowmich, Aklant K.; Dell, Zachary R.; Pandian, Arun; Stanic, Milos; Stellingwerf, Robert F.; Swisher, Nora C.

2017-10-01

We focus on classical problem of dependence on the initial conditions of the initial growth-rate of strong shocks driven Richtmyer-Meshkov instability (RMI) by developing a novel empirical model and by employing rigorous theories and Smoothed Particle Hydrodynamics (SPH) simulations to describe the simulations data with statistical confidence in a broad parameter regime. For given values of the shock strength, fluids' density ratio, and wavelength of the initial perturbation of the fluid interface, we find the maximum value of RMI initial growth-rate, the corresponding amplitude scale of the initial perturbation, and the maximum fraction of interfacial energy. This amplitude scale is independent of the shock strength and density ratio, and is characteristic quantity of RMI dynamics. We discover the exponential decay of the ratio of the initial and linear growth-rates of RMI with the initial perturbation amplitude that excellently agrees with available data. National Science Foundation, USA.

Maximum initial growth-rate of strong-shock-driven Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Abarzhi, Snezhana I.; Bhowmich, Aklant K.; Dell, Zachary R.; Pandian, Arun; Stanic, Milos; Stellingwerf, Robert F.; Swisher, Nora C.

2017-11-01

We focus on classical problem of dependence on the initial conditions of the initial growth-rate of strong shocks driven Richtmyer-Meshkov instability (RMI) by developing a novel empirical model and by employing rigorous theories and Smoothed Particle Hydrodynamics (SPH) simulations to describe the simulations data with statistical confidence in a broad parameter regime. For given values of the shock strength, fluids' density ratio, and wavelength of the initial perturbation of the fluid interface, we find the maximum value of RMI initial growth-rate, the corresponding amplitude scale of the initial perturbation, and the maximum fraction of interfacial energy. This amplitude scale is independent of the shock strength and density ratio, and is characteristic quantity of RMI dynamics. We discover the exponential decay of the ratio of the initial and linear growth-rates of RMI with the initial perturbation amplitude that excellently agrees with available data. National Science Foundation, USA.

High-risk occupations for suicide.

PubMed

Roberts, S E; Jaremin, B; Lloyd, K

2013-06-01

High occupational suicide rates are often linked to easy occupational access to a method of suicide. This study aimed to compare suicide rates across all occupations in Britain, how they have changed over the past 30 years, and how they may vary by occupational socio-economic group. Method We used national occupational mortality statistics, census-based occupational populations and death inquiry files (for the years 1979-1980, 1982-1983 and 2001-2005). The main outcome measures were suicide rates per 100 000 population, percentage changes over time in suicide rates, standardized mortality ratios (SMRs) and proportional mortality ratios (PMRs). Several occupations with the highest suicide rates (per 100 000 population) during 1979-1980 and 1982-1983, including veterinarians (ranked first), pharmacists (fourth), dentists (sixth), doctors (tenth) and farmers (thirteenth), have easy occupational access to a method of suicide (pharmaceuticals or guns). By 2001-2005, there had been large significant reductions in suicide rates for each of these occupations, so that none ranked in the top 30 occupations. Occupations with significant increases over time in suicide rates were all manual occupations whereas occupations with suicide rates that decreased were mainly professional or non-manual. Variation in suicide rates that was explained by socio-economic group almost doubled over time from 11.4% in 1979-1980 and 1982-1983 to 20.7% in 2001-2005. Socio-economic forces now seem to be a major determinant of high occupational suicide rates in Britain. As the increases in suicide rates among manual occupations occurred during a period of economic prosperity, carefully targeted suicide prevention initiatives could be beneficial.

Kinetics of successive seeding of monodisperse polystyrene latexes. I - Initiation via potassium persulfate. II - Azo initiators with and without inhibitors

NASA Technical Reports Server (NTRS)

Sudol, E. D.; El-Aasser, M. S.; Vanderhoff, J. W.

1986-01-01

The polymerization kinetics of monodisperse polystyrene latexes with diameters of 1 micron are studied. The monodisperse latexes were prepared by the successive seeding method using 1 mM K2S2O8 with an 8 percent emulsifier surface coverage and 0.5 mM K2S2O8 with a 4 percent emulsifier surface coverage, and the kinetics were measured in a piston/cylinder dialometer. The data reveal that the polymerization rate decreases with increasing particle size; and the surface charge decreases with increasing particle size. The effects of initiators (AIBN and AMBN) and inhibitors (NH24SCN, NaNO2, and hydroquinone) on the product monodispersity and polymerization kinetics of latexes with diameters greater than 1 micron are investigated in a second experiment. It is observed that hydroquinone combined with AMBN are most effective in reducing nucleation without causing flocculation. It is noted that the kinetic transition from emulsion to bulk is complete for a particle size exceeding 1 micron in which the polymerization rate is independent of the particle size.

Denitrification using a monopolar electrocoagulation/flotation (ECF) process.

PubMed

Emamjomeh, Mohammad M; Sivakumar, Muttucumaru

2009-01-01

Nitrate levels are limited due to health concerns in potable water. Nitrate is a common contaminant in water supplies, and especially prevalent in surface water supplies and shallow wells. Nitrate is a stable and highly soluble ion with low potential for precipitation or adsorption. These properties make it difficult to remove using conventional water treatment methods. A laboratory batch electrocoagulation/flotation (ECF) reactor was designed to investigate the effects of different parameters such as electrolysis time, electrolyte pH, initial nitrate concentration, and current rate on the nitrate removal efficiency. The optimum nitrate removal was observed at a pH range of between 9 and 11. It appeared that the nitrate removal rate was 93% when the initial nitrate concentration and electrolysis time respectively were 100 mg L(-1)-NO(3)(-) and 40 min. The results showed a linear relationship between the electrolysis time for total nitrate removal and the initial nitrate concentration. It is concluded that the electrocoagulation technology for denitrification can be an effective preliminary process when the ammonia byproduct must be effectively removed by the treatment facilities.

High-rate operant behavior in two mouse strains: a response-bout analysis.

PubMed

Johnson, Joshua E; Pesek, Erin F; Newland, M Christopher

2009-06-01

Operant behavior sometimes occurs in bouts characterized by an initiation rate, within-bout response rate, and bout length. The generality of this structure was tested using high-rate nose-poking in mice. Reinforcement of short interresponse times produced high response rates while a random-interval schedule held reinforcement rates constant. BALB/c mice produced bouts that were more frequent, longer, and contained a higher within-bout rate of responding (nine nose-pokes/s) than did the C57BL/6 mice (five nose-pokes/s). Adding a running wheel decreased total nose-pokes and bout length, and increased bout-initiation rate. Free-feeding reduced nose-poking by decreasing bout-initiation rate. Photoperiod reversal decreased bout-initiation rate but not total nose-poke rate. Despite strain differences in bout structure, both strains responded similarly to the interventions. The three bout measures were correlated with overall rate but not with each other. Log-survival analyses provided independent descriptors of the structure of high-rate responding in these two strains.

GraphPrints: Towards a Graph Analytic Method for Network Anomaly Detection

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

Harshaw, Chris R; Bridges, Robert A; Iannacone, Michael D

This paper introduces a novel graph-analytic approach for detecting anomalies in network flow data called \\textit{GraphPrints}. Building on foundational network-mining techniques, our method represents time slices of traffic as a graph, then counts graphlets\\textemdash small induced subgraphs that describe local topology. By performing outlier detection on the sequence of graphlet counts, anomalous intervals of traffic are identified, and furthermore, individual IPs experiencing abnormal behavior are singled-out. Initial testing of GraphPrints is performed on real network data with an implanted anomaly. Evaluation shows false positive rates bounded by 2.84\\% at the time-interval level, and 0.05\\% at the IP-level with 100\\% truemore » positive rates at both.« less

On the accuracy of the LSC-IVR approach for excitation energy transfer in molecular aggregates

NASA Astrophysics Data System (ADS)

Teh, Hung-Hsuan; Cheng, Yuan-Chung

2017-04-01

We investigate the applicability of the linearized semiclassical initial value representation (LSC-IVR) method to excitation energy transfer (EET) problems in molecular aggregates by simulating the EET dynamics of a dimer model in a wide range of parameter regime and comparing the results to those obtained from a numerically exact method. It is found that the LSC-IVR approach yields accurate population relaxation rates and decoherence rates in a broad parameter regime. However, the classical approximation imposed by the LSC-IVR method does not satisfy the detailed balance condition, generally leading to incorrect equilibrium populations. Based on this observation, we propose a post-processing algorithm to solve the long time equilibrium problem and demonstrate that this long-time correction method successfully removed the deviations from exact results for the LSC-IVR method in all of the regimes studied in this work. Finally, we apply the LSC-IVR method to simulate EET dynamics in the photosynthetic Fenna-Matthews-Olson complex system, demonstrating that the LSC-IVR method with long-time correction provides excellent description of coherent EET dynamics in this typical photosynthetic pigment-protein complex.

Gas embolotherapy: Bubble evolution in acoustic droplet vaporization and design of a benchtop microvascular model

NASA Astrophysics Data System (ADS)

Wong, Zheng Zheng

This work was motivated by an ongoing development of a potential embolotherapy technique to occlude blood flow to tumors using gas bubbles selectively formed by in vivo acoustic droplet vaporization (ADV) of liquid perfluorocarbon droplets. Mechanisms behind the ADV, transport and lodging of emboli need to be understood before gas embolotherapy can translate to the clinic. Evolution of a bubble from acoustic droplet vaporization in a rigid tube, under physiological and room temperature conditions, was observed via ultra-high speed imaging. Effective radii and radial expansion ratios were obtained by processing the images using Image] software. At physiological temperature, a radial expansion ratio of 5.05 was attained, consistent with theoretical prediction. The initial radial growth rate was linear, after which the growth rate increased proportionally with square root of time. Nondimensionalization revealed that the subsequent growth rate also varied inversely with square root of initial radius. Eventually growth became asymptotic. No collapse was observed. A theoretical model derived from a modified Bernoulli equation, and a computational model by Ye & Bull (2004), were compared respectively with experimental results. Initial growth rates were predicted correctly by both models. Experimental results showed heavy damping of growth rate as the bubble grew towards the wall, whereas both models predicted an overshoot in growth followed by multiple oscillations. The theoretical model broke down near the wall; the computational model gave a reasonable bubble shape near the wall but would require correct initial pressure values to be accurate. At room temperature, the expansion ratio shot to 1.43 initially and oscillated down to 1.11, far below the theoretical prediction. Failure of the bubble to expand fully could be due to unconsumed or condensed liquid perfluorocarbon. A new fabrication method via non-lithographic means was devised to make a circular-lumen microchannel out of PDMS, with a diameter as small as 80 microns to mimic the size of a medium arteriole. The microchannel was endothelialized successfully, with a fairly homogeneous distribution along the length. Cell viability assays confirmed the viability of cells maintained in the microchannel. Bubble motion experiments performed with the benchtop microvascular model demonstrated its feasibility.

Establishment of joint attention in dyads involving hearing mothers of deaf and hearing children, and its relation to adaptive social behavior.

PubMed

Nowakowski, Matilda E; Tasker, Susan L; Schmidt, Louis A

2009-01-01

Mounting evidence points to joint attention as a mediating variable in children's adaptive behavior development. Joint attention in interactions between hearing mothers and congenitally deaf (n = 27) and hearing (n = 29) children, ages 18-36 months, was examined. All deaf children had severe to profound hearing loss. Mother-child interactions were coded for maternally initiated and child-initiated success rates in establishing joint attention; mothers completed ratings of their children's adaptive behavior. Hearing mother-deaf child dyads had significantly lower maternally initiated success rates. No significant between-group differences on child-initiated success rates were shown. Maternal ratings of adaptive behavior were significantly lower for deaf children, and related positively and significantly to both child-initiated and maternally initiated success rates. The findings suggest that mother-child interactions that are low in successful establishment of joint attention might mediate the development of socioemotional problems evident in deaf children with hearing families.

A comparative study of the single-mode Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Bai, X.; Deng, X.-L.; Jiang, L.

2018-07-01

In this work, the single-mode Richtmyer-Meshkov instability is studied numerically to find a reasonable nonlinear theoretical model which can be applied to predict the interface evolution from the linear stage to the early nonlinear stage. The cut-cell-based sharp-interface methods MuSiC+ (Chang et al. in J Comput Phys 242:946-990, 2013) and CCGF (Bai and Deng in Adv Appl Math Mech 9(5):1052-1075, 2017) are applied to generate numerical results for comparisons. Classical Air-SF6 and Air-Helium conditions are applied in this study, and initial amplitude and Atwood number are varied for comparison. Comparisons to the simulation results from the literature show the applicability of MuSiC+ and CCGF. Comparisons to the nonlinear theoretical models show that ZS (Zhang and Sohn in Phys Lett A 212:149-155, 1996; Phys Fluids 9:1106-1124, 1997), SEA (Sadot et al. in Phys Rev Lett 80:1654-1657, 1998), and DR (Dimonte and Ramaprabhu in Phys Fluids 22:014104, 2010) models are valid for both spike and bubble growth rates, and MIK (Mikaelian in Phys Rev E 67:026319, 2003) and ZG (Zhang and Guo in J Fluid Mech 786:47-61, 2016) models are valid for bubble growth rate, when the initial perturbation is small and the Atwood number is low, but only the DR model is applicable for both spike and bubble growth rates when the initial perturbation amplitude and the Atwood number are large. A new term of non-dimensional initial perturbation amplitude is presented and multiplied to the DR model to get a unified fitted DR model, which gives consistent results to the simulation ones for small and large initial amplitudes.

Quantifying the risks and benefits of efavirenz use in HIV-infected women of childbearing age in the United States

PubMed Central

Hsu, HE; Rydzak, CE; Cotich, KL; Wang, B; Sax, PE; Losina, E; Freedberg, KA; Goldie, SJ; Lu, Z; Walensky, RP

2010-01-01

Objectives We quantified the benefits (life expectancy gains) and harms (efavirenz-related teratogenicity) associated with using efavirenz in HIV-infected women of childbearing age in the United States. Methods We used data from the Women’s Interagency HIV Study in an HIV disease simulation model to estimate life expectancy in women who receive an efavirenz-based initial antiretroviral regimen compared with those who delay efavirenz use and receive a boosted protease inhibitor-based initial regimen. To estimate excess risk of teratogenic events with and without efavirenz exposure per 100,000 women, we incorporated literature-based rates of pregnancy, live births, and teratogenic events into a decision analytic model. We assumed a teratogenicity risk of 2.90 events/100 live births in women exposed to efavirenz during pregnancy and 2.68/100 live births in unexposed women. Results Survival for HIV-infected women who received an efavirenz-based initial antiretroviral therapy regimen was 0.89 years greater than for women receiving non-efavirenz-based initial therapy (28.91 vs. 28.02 years). The rate of teratogenic events was 77.26/100,000 exposed women, compared with 72.46/100,000 unexposed women. Survival estimates were sensitive to variations in treatment efficacy and AIDS-related mortality. Estimates of excess teratogenic events were most sensitive to pregnancy rates and number of teratogenic events/100 live births in efavirenz-exposed women. Conclusions Use of non-efavirenz-based initial antiretroviral therapy in HIV-infected women of childbearing age may reduce life expectancy gains from antiretroviral treatment, but may also prevent teratogenic events. Decision-making regarding efavirenz use presents a tradeoff between these two risks; this study can inform discussions between patients and health care providers. PMID:20561082

Improvement of Early Antenatal Care Initiation

PubMed Central

Oumudee, Nurlisa; Armeeroh, Masuenah; Nima, Niamina; Duerahing, Nurosanah

2018-01-01

Background: Although antenatal care (ANC) coverage has been increasing in low- and middle-income countries, the adherence to the ANC initiation standards at gestational age <12 weeks was inadequate including Thailand. The study aimed to improve the rate of early ANC initiation by training the existing local health volunteers (LHVs) in 3 southernmost provinces of Thailand. Methods: A clustered nonrandomized intervention study was conducted from November 2012 to February 2014. One district of each province was selected to be the study intervention districts for that province. A total of 124 LHVs in the intervention districts participated in the knowledge–counseling intervention. It was organized as half-day workshop using 2 training modules each comprising a 30-minute lecture followed by counseling practice in pairs for 1 hour. Outcome was the rate of early ANC initiation among women giving birth, and its association with intervention, meeting an LHV, and months after training was analyzed. Results: Of 6677 women, 3178 and 3499 women were in the control and intervention groups, respectively. Rates of early ANC were significantly improved after the intervention (adjusted odds ratio [OR]: 1.29, 95% confidence interval [CI]: 1.17-1.43, P < .001) and meeting an LHV (adjusted OR: 2.06, 95% CI: 1.86-2.29, P < .001), but lower at 6 months after training (adjusted OR: 0.76, 95% CI: 0.60-0.96, P = .002). Almost all women (99.7%) in the intervention group who met an LHV reported that they were encouraged to attend early ANC. Conclusion: Training LHVs in communities by knowledge–counseling intervention significantly improved early ANC initiation, but the magnitude of change was still limited. PMID:29657959

A comparative study of the single-mode Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Bai, X.; Deng, X.-L.; Jiang, L.

2017-11-01

In this work, the single-mode Richtmyer-Meshkov instability is studied numerically to find a reasonable nonlinear theoretical model which can be applied to predict the interface evolution from the linear stage to the early nonlinear stage. The cut-cell-based sharp-interface methods MuSiC+ (Chang et al. in J Comput Phys 242:946-990, 2013) and CCGF (Bai and Deng in Adv Appl Math Mech 9(5):1052-1075, 2017) are applied to generate numerical results for comparisons. Classical Air-SF6 and Air-Helium conditions are applied in this study, and initial amplitude and Atwood number are varied for comparison. Comparisons to the simulation results from the literature show the applicability of MuSiC+ and CCGF. Comparisons to the nonlinear theoretical models show that ZS (Zhang and Sohn in Phys Lett A 212:149-155, 1996; Phys Fluids 9:1106-1124, 1997), SEA (Sadot et al. in Phys Rev Lett 80:1654-1657, 1998), and DR (Dimonte and Ramaprabhu in Phys Fluids 22:014104, 2010) models are valid for both spike and bubble growth rates, and MIK (Mikaelian in Phys Rev E 67:026319, 2003) and ZG (Zhang and Guo in J Fluid Mech 786:47-61, 2016) models are valid for bubble growth rate, when the initial perturbation is small and the Atwood number is low, but only the DR model is applicable for both spike and bubble growth rates when the initial perturbation amplitude and the Atwood number are large. A new term of non-dimensional initial perturbation amplitude is presented and multiplied to the DR model to get a unified fitted DR model, which gives consistent results to the simulation ones for small and large initial amplitudes.

Deciphering mRNA Sequence Determinants of Protein Production Rate

NASA Astrophysics Data System (ADS)

Szavits-Nossan, Juraj; Ciandrini, Luca; Romano, M. Carmen

2018-03-01

One of the greatest challenges in biophysical models of translation is to identify coding sequence features that affect the rate of translation and therefore the overall protein production in the cell. We propose an analytic method to solve a translation model based on the inhomogeneous totally asymmetric simple exclusion process, which allows us to unveil simple design principles of nucleotide sequences determining protein production rates. Our solution shows an excellent agreement when compared to numerical genome-wide simulations of S. cerevisiae transcript sequences and predicts that the first 10 codons, which is the ribosome footprint length on the mRNA, together with the value of the initiation rate, are the main determinants of protein production rate under physiological conditions. Finally, we interpret the obtained analytic results based on the evolutionary role of the codons' choice for regulating translation rates and ribosome densities.

Quality Improvement Initiatives Lead to Reduction in Nulliparous Term Singleton Vertex Cesarean Delivery Rate

PubMed Central

Vadnais, Mary A.; Hacker, Michele R.; Shah, Neel T.; Jordan, JoAnn; Modest, Anna M.; Siegel, Molly; Golen, Toni H.

2018-01-01

Background The nulliparous term singleton vertex (NTSV) cesarean delivery rate has been recognized as a meaningful benchmark. Variation in the NTSV cesarean delivery rate among hospitals and providers suggests many hospitals may be able to safely improve their rates. The NTSV cesarean delivery rate at the authors’ institution was higher than state and national averages. This study was conducted to determine the influence of a set of quality improvement interventions on the NTSV cesarean delivery rate. Methods From 2008 through 2015, at a single tertiary care academic medical center, a multi-strategy approach that included provider education, provider feedback, and implementation of new policies was used to target evidence-based and inferred factors that influence the NTSV cesarean delivery rate. Data on mode of delivery, maternal outcomes, and neonatal outcomes were collected from birth certificates and administrative claims data. The Cochran-Armitage test and linear regression were used to calculate the p-trend for categorical and continuous variables, respectively. Results More than 20,000 NTSV deliveries were analyzed, including more than 15,000 during the intervention period. The NTSV cesarean delivery rate declined from 35% to 21% over eight years. The total cesarean delivery rate declined as well. Increase in meconium aspiration syndrome and maternal transfusion were observed. Conclusion Quality improvement initiatives can decrease the NTSV cesarean delivery rate. Any increased incidence of fetal or maternal complications associated with decreased NTSV cesarean delivery rate should be considered in the context of the risks and benefits of vaginal delivery compared to cesarean delivery. PMID:28334563

Forced Ignition Study Based On Wavelet Method

NASA Astrophysics Data System (ADS)

Martelli, E.; Valorani, M.; Paolucci, S.; Zikoski, Z.

2011-05-01

The control of ignition in a rocket engine is a critical problem for combustion chamber design. Therefore it is essential to fully understand the mechanism of ignition during its earliest stages. In this paper the characteristics of flame kernel formation and initial propagation in a hydrogen-argon-oxygen mixing layer are studied using 2D direct numerical simulations with detailed chemistry and transport properties. The flame kernel is initiated by adding an energy deposition source term in the energy equation. The effect of unsteady strain rate is studied by imposing a 2D turbulence velocity field, which is initialized by means of a synthetic field. An adaptive wavelet method, based on interpolating wavelets is used in this study to solve the compressible reactive Navier- Stokes equations. This method provides an alternative means to refine the computational grid points according to local demands of the physical solution. The present simulations show that in the very early instants the kernel perturbed by the turbulent field is characterized by an increased burning area and a slightly increased rad- ical formation. In addition, the calculations show that the wavelet technique yields a significant reduction in the number of degrees of freedom necessary to achieve a pre- scribed solution accuracy.

Have we left some behind? Trends in socio-economic inequalities in breastfeeding initiation: a population-based epidemiological surveillance study.

PubMed

Nickel, Nathan C; Martens, Patricia J; Chateau, Dan; Brownell, Marni D; Sarkar, Joykrishna; Goh, Chun Yan; Burland, Elaine; Taylor, Carole; Katz, Alan

2014-07-31

Breastfeeding is associated with improved health. Surveillance data show that breastfeeding initiation rates have increased; however, limited work has examined trends in socio-economic inequalities in initiation. The study's research question was whether socio-economic inequalities in breastfeeding initiation have changed over the past 20 years. This population-based study is a project within PATHS Equity for Children. Analyses used hospital discharge data for Manitoba mother-infant dyads with live births, 1988-2011 (n=316,027). Income quintiles were created, each with ~20% of dyads. Three-year, overall and by-quintile breastfeeding initiation rates were estimated for Manitoba and two hospitals. Age-adjusted rates were estimated for Manitoba. Rates were modelled using generalized linear models. Three measures, rate ratios (RRs), rate differences (RDs) and concentration indices, assessed inequality at each time point. We also compared concentration indices with Gini coefficients to assess breastfeeding inequality vis-à-vis income inequality. Trend analyses tested for changes over time. Manitoba and Hospital A initiation rates increased; Hospital B rates did not change. Significant inequalities existed in nearly every period, across all three measures: RRs, RDs and concentration indices. RRs and concentration indices suggested little to no change in inequality from 1988 to 2011. RDs for Manitoba (comparing initiation in the highest to lowest income quintiles) did not change significantly over time. RDs decreased for Hospital A, suggesting decreasing socio-economic inequalities in breastfeeding; RDs increased for Hospital B. Income inequality increased significantly in Manitoba during the study period. Overall breastfeeding initiation rates can improve while inequality persists or worsens.

Spent Fuel Assay with an Ultra-High Rate HPGe Spectrometer

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

Fast, James; Fulsom, Bryan; Pitts, Karl

2015-07-01

Traditional verification of spent nuclear fuel (SNF) includes determination of initial enrichment, burnup and cool down time (IE, BU, CT). Along with neutron measurements, passive gamma assay provides important information for determining BU and CT. Other gamma-ray-based assay methods such as passive tomography and active delayed gamma offer the potential to measure the spatial distribution of fission products and the fissile isotopic concentration of the fuel, respectively. All fuel verification methods involving gamma-ray spectroscopy require that the spectrometers manage very high count rates while extracting the signatures of interest. PNNL has developed new digital filtering and analysis techniques to producemore » an ultra-high rate gamma-ray spectrometer from a standard coaxial high-purity germanium (HPGe) crystal. This 37% relative efficiency detector has been operated for SNF measurements at input count rates of 500-1300 kcps and throughput in excess of 150 kcps. Optimized filtering algorithms preserve the spectroscopic capability of the system even at these high rates. This paper will present the results of both passive and active SNF measurement performed with this system at PNNL. (authors)« less

Geographic Factors and Human Papillomavirus (HPV) Vaccination Initiation Among Adolescent Girls in the United States

PubMed Central

Henry, Kevin A.; Stroup, Antoinette M.; Warner, Echo L; Kepka, Deanna

2015-01-01

Background This study is among the first to explore geographic factors that may be associated with HPV vaccine uptake in the United States. Methods Data from the 2011 and 2012 National Immunization Survey-Teen for 20,565 female adolescents aged 13-17 years were analyzed to examine associations of HPV vaccine initiation (receipt of at least one dose) with ZIP code-level geographic factors. Logistic regression including individual and geographic factors was used to estimate the odds of HPV vaccine initiation. Results Approximately 53% of girls initiated the HPV vaccine in both years. Girls in high poverty communities had higher HPV vaccine initiation compared to those in low poverty communities (61.1% vs .52.4%; Adjusted Odds Ratio [AOR] 1.18,95%CI 1.04-1.33). Initiation was higher among girls in communities where the majority of the population was Hispanic (69.0% vs. 49.9%;AOR 1.64, 95%CI 1.43-1.87) or non-Hispanic mixed race (60.4% vs. 49.9%; AOR 1.30, 95%CI 1.17-1.44) compared to majority non-Hispanic white communities. Interactions between individual-level race/ethnicity and community racial–ethnic composition indicated significantly higher odds of initiation among Hispanic girls living in Hispanic communities compared to Hispanic girls living in predominately NHW (AOR 2.23;95%CI 1.87-2.65) or NHB (AOR 1.90; 95%CI 1.20-3.04)communities, respectively Conclusion Initiation rates of HPV vaccination among teen girls were highest in the poorest communities and among Hispanics living in communities where the racial–ethnic composition was predominantly Hispanic or mixed race. Impact Given low HPV vaccination rates in the United States, these results provide important evidence to inform public health interventions to increase HPV vaccination. PMID:26768989

High repetition rate laser induced fluorescence applied to Surfatron Induced Plasmas

NASA Astrophysics Data System (ADS)

van der Mullen, J. J. A. M.; Palomares, J. M.; Carbone, E. A. D.; Graef, W.; Hübner, S.

2012-05-01

The reaction kinetics in the excitation space of Ar and the conversion space of Ar-molecule mixtures are explored using a combination of high rep-rate YAG-Dye laser systems with a well defined and easily controllable Surfatron Induced Plasma set-up. Applying the method of Saturation Time Resolved Laser Induced Fluorescence (SaTiRe-LIF), we could trace excitation and conversion channels and determine rates of electron and heavy particle excitation kinetics. The time resolved density disturbances observed in the Ar excitation space, which are initiated by the laser, reveal the excitation channels and corresponding rates; responses of the molecular radiation in Ar-molecule mixtures corresponds to the presence of conversion processes induced by heavy particle excitation kinetics.

Evaluation of 6 remote First Nations community-based buprenorphine programs in northwestern Ontario: Retrospective study.

PubMed

Mamakwa, Solomon; Kahan, Meldon; Kanate, Dinah; Kirlew, Mike; Folk, David; Cirone, Sharon; Rea, Sara; Parsons, Pierre; Edwards, Craig; Gordon, Janet; Main, Fiona; Kelly, Len

2017-02-01

To evaluate established opioid addiction treatment programs that use traditional healing in combination with buprenorphine-naloxone maintenance treatment in 6 First Nations communities in the Sioux Lookout region of northwestern Ontario. Retrospective cohort study. Six First Nations communities in northwestern Ontario. A total of 526 First Nations participants in opioid-dependence treatment programs. Buprenorphine-naloxone substitution therapy and First Nations healing programming. Retention rates and urine drug screening (UDS) results. Treatment retention rates at 6, 12, and 18 months were 84%, 78%, and 72%, respectively. We estimate that the rate at 24 months will also be more than 70%. The UDS programming varied and was implemented in only 1 community. Initially urine testing was voluntary and it then became mandatory. Screening with either method found the proportion of urine samples with negative results for illicit opioids ranged between 84% and 95%. The program's treatment retention rates and negative UDS results were higher than those reported for most methadone and buprenorphine-naloxone programs, despite a patient population where severe posttraumatic stress disorder is endemic, and despite the programs' lack of resources and addiction expertise. Community-based programs like these overcome the initial challenge of cultural competence. First Nations communities in other provinces should establish their own buprenorphinenaloxone programs, using local primary care physicians as prescribers. Sustainable core funding is needed for programming, long-term aftercare, and trauma recovery for such initiatives. Copyright© the College of Family Physicians of Canada.

Evaluation of 6 remote First Nations community-based buprenorphine programs in northwestern Ontario

PubMed Central

Mamakwa, Solomon; Kahan, Meldon; Kanate, Dinah; Kirlew, Mike; Folk, David; Cirone, Sharon; Rea, Sara; Parsons, Pierre; Edwards, Craig; Gordon, Janet; Main, Fiona; Kelly, Len

2017-01-01

Abstract Objective To evaluate established opioid addiction treatment programs that use traditional healing in combination with buprenorphine-naloxone maintenance treatment in 6 First Nations communities in the Sioux Lookout region of northwestern Ontario. Design Retrospective cohort study. Setting Six First Nations communities in northwestern Ontario. Participants A total of 526 First Nations participants in opioid-dependence treatment programs. Intervention Buprenorphine-naloxone substitution therapy and First Nations healing programming. Main outcome measures Retention rates and urine drug screening (UDS) results. Results Treatment retention rates at 6, 12, and 18 months were 84%, 78%, and 72%, respectively. We estimate that the rate at 24 months will also be more than 70%. The UDS programming varied and was implemented in only 1 community. Initially urine testing was voluntary and it then became mandatory. Screening with either method found the proportion of urine samples with negative results for illicit opioids ranged between 84% and 95%. Conclusion The program’s treatment retention rates and negative UDS results were higher than those reported for most methadone and buprenorphine-naloxone programs, despite a patient population where severe posttraumatic stress disorder is endemic, and despite the programs’ lack of resources and addiction expertise. Community-based programs like these overcome the initial challenge of cultural competence. First Nations communities in other provinces should establish their own buprenorphinenaloxone programs, using local primary care physicians as prescribers. Sustainable core funding is needed for programming, long-term aftercare, and trauma recovery for such initiatives. PMID:28209683

The Role of Motivation in Family-Based Guided Self-Help Treatment for Pediatric Obesity

PubMed Central

Norman, Gregory J.; Crow, Scott J.; Rock, Cheryl L.; Boutelle, Kerri N.

2014-01-01

Abstract Background: Identifying factors associated with effective treatment for childhood obesity is important to improving weight loss outcomes. The current study investigated whether child or parent motivation throughout the course of treatment predicted reductions in BMI. Methods: Fifty 8- to 12-year-old children with overweight and obesity (BMI percentiles 85–98%) and their parents participated in a guided self-help weight loss program, which included 12 brief sessions across 5 months. Parents and interventionists reported on child and parent motivation level at each session. Multilevel slopes-as-outcome models were used to examine growth trajectories for both child and parent BMI across sessions. Results: Greater interventionist-rated child motivation predicted greater reductions in child BMI; parent motivation did not. However, interventionist-rated parent motivation predicted greater reductions in parent BMI, and its impact on BMI became more pronounced over the course of treatment, such that sustained motivation was more important than initial motivation. Children who were older, Latino, or who had lower initial BMIs had slower reductions in BMI. Conclusions: This study suggests that motivation may be an important predictor of reduced BMI in child obesity treatment, with sustained motivation being more important than initial motivation. In particular, interventionist-rated, but not parent-rated, motivation is a robust predictor of child and parent BMI outcomes. Future research may evaluate whether motivational interventions can enhance outcome, with particular attention to improving outcomes for Latino children. PMID:25181608

Kinetics of thermal and photo-initiated release of tris (1,3-dichloro-2-propyl) phosphate (TDCP) flame retardant from polyurethane foam materials.

PubMed

Ghanem, Raed A

2015-01-01

Kinetics of thermal and photo-initiated release of Tris (1.3-dichloro-2-propyl) phosphate (TDCP) from the polyurethane foam (PUF) materials were studied using a validated chromatographic method with linear calibration curve in the range of 0.03-400 μg mL(-1). Time dependence of TDCP leaching from foam samples was found to follow first-order kinetics; with rate constants directly dependent on ageing temperatures and intensity of UV radiation, rate constants for the thermally and photo initiated were 3.6 × 10(-3), 1.03 × 10(-2), 3.6 × 10(-2) and 3.94 × 10(-2) day(-1), respectively. Migration of TDCP from foam samples simulating skin or oral exposure were observed from all samples regardless of their ageing history, the presence of biological fluids found to enhance the migration rate. Oral exposure to foam material contains TDCP, which was simulated using the Head-over-Heels test, reveals that an average amount of ∼ 1.7% wt./wt. of the total amount of TDCP was found to leach into biological fluids, and it significantly increased to ∼ 6.0% wt./wt. due to ageing conditions. Direct contact between foam material and skin simulated by using the Contact Blotting test reveals that TDCP is transferred from both aged and un-aged samples at different rates, due to the presence of biological fluids; the transferred amount is increased with ageing conditions.

IFACEwat: the interfacial water-implemented re-ranking algorithm to improve the discrimination of near native structures for protein rigid docking.

PubMed

Su, Chinh; Nguyen, Thuy-Diem; Zheng, Jie; Kwoh, Chee-Keong

2014-01-01

Protein-protein docking is an in silico method to predict the formation of protein complexes. Due to limited computational resources, the protein-protein docking approach has been developed under the assumption of rigid docking, in which one of the two protein partners remains rigid during the protein associations and water contribution is ignored or implicitly presented. Despite obtaining a number of acceptable complex predictions, it seems to-date that most initial rigid docking algorithms still find it difficult or even fail to discriminate successfully the correct predictions from the other incorrect or false positive ones. To improve the rigid docking results, re-ranking is one of the effective methods that help re-locate the correct predictions in top high ranks, discriminating them from the other incorrect ones. Our results showed that the IFACEwat increased both the numbers of the near-native structures and improved their ranks as compared to the initial rigid docking ZDOCK3.0.2. In fact, the IFACEwat achieved a success rate of 83.8% for Antigen/Antibody complexes, which is 10% better than ZDOCK3.0.2. As compared to another re-ranking technique ZRANK, the IFACEwat obtains success rates of 92.3% (8% better) and 90% (5% better) respectively for medium and difficult cases. When comparing with the latest published re-ranking method F2Dock, the IFACEwat performed equivalently well or even better for several Antigen/Antibody complexes. With the inclusion of interfacial water, the IFACEwat improves mostly results of the initial rigid docking, especially for Antigen/Antibody complexes. The improvement is achieved by explicitly taking into account the contribution of water during the protein interactions, which was ignored or not fully presented by the initial rigid docking and other re-ranking techniques. In addition, the IFACEwat maintains sufficient computational efficiency of the initial docking algorithm, yet improves the ranks as well as the number of the near native structures found. As our implementation so far targeted to improve the results of ZDOCK3.0.2, and particularly for the Antigen/Antibody complexes, it is expected in the near future that more implementations will be conducted to be applicable for other initial rigid docking algorithms.

Probing collagen-enzyme mechanochemistry in native tissue with dynamic, enzyme-induced creep

PubMed Central

Zareian, Ramin; Church, Kelli P.; Saeidi, Nima; Flynn, Brendan P.; Beale, John W.; Ruberti, Jeffrey W.

2012-01-01

Mechanical strain or stretch of collagen has been shown to be protective of fibrils against both thermal and enzymatic degradation. The details of this mechanochemical relationship could change our understanding of load-bearing tissue formation, growth, maintenance and disease in vertebrate animals. However, extracting a quantitative relationship between strain and the rate of enzymatic degradation is extremely difficult in bulk tissue due to confounding diffusion effects. In this investigation, we develop a dynamic, enzyme-induced creep assay and diffusion/reaction rate scaling arguments to extract a lower bound on the relationship between strain and the cutting rate of bacterial collagenase (BC) at low strains. The assay method permits continuous, forced probing of enzyme-induced strain which is very sensitive to degradation rate differences between specimens at low initial strain. The results, obtained on uniaxially-loaded strips of bovine corneal tissue (0.1, 0.25 or 0.5 N), demonstrate that small differences in strain alter the enzymatic cutting rate of the BC substantially. It was estimated that a change in tissue elongation of only 1.5% (at ~5% strain) reduces the maximum cutting-rate of the enzyme by more than half. Estimation of the average load per monomer in the tissue strips indicates that this protective “cutoff” occurs when the collagen monomers are transitioning from an entropic to an energetic mechanical regime. The continuous tracking of the enzymatic cleavage rate as a function of strain during the initial creep response indicates that the decrease in the cleavage rate of the BC is non-linear (initially-steep between 4.5 and 6.5% then flattens out from 6.5–9.5%). The high sensitivity to strain at low strain implies that even lightly-loaded collagenous tissue may exhibit significant strain-protection. The dynamic, enzyme-induced creep assay described herein has the potential to permit the rapid characterization of collagen/enzyme mechanochemistry in many different tissue types. PMID:20429513

Clinically relevant reductions in HbA1c without hypoglycaemia: results across four studies of saxagliptin

PubMed Central

Karyekar, C S; Frederich, R; Ravichandran, S

2013-01-01

BackgroundIn four 24-week controlled studies, the antihyperglycaemic efficacy of saxagliptin was demonstrated in patients with type 2 diabetes mellitus as add-on therapy to glyburide, a thiazolidinedione, or metformin, and when used in initial combination with metformin vs. metformin monotherapy in drug-naive patients. MethodsData from these studies were analysed to compare the proportions of patients who achieved specific reductions from baseline in glycated haemoglobin [HbA1c; reductions of ≥ 0.5% and ≥ 0.7% in all studies (prespecified); reductions ≥ 1.0% in the add-on studies and ≥ 1.0% to ≥ 2.5% in the initial combination study (post hoc)] for saxagliptin vs. comparator at week 24. We report overall rates of glycaemic response defined by these reductions in HbA1c and rates of response without experiencing hypoglycaemia. ResultsLarge glycaemic response rates were higher with saxagliptin 2.5 and 5 mg/day than with comparator (HbA1c ≥ 1.0%, 31.7–50.3% vs. 10.3–20.0%) as add-on therapy and higher with saxagliptin 5 mg/day as initial combination with metformin than with metformin monotherapy (HbA1c ≥ 2.0%, 68.3% vs. 49.8%) in drug-naive patients. Addition of saxagliptin was associated with a low incidence of hypoglycaemia; overall response rates and response rates excluding patients who experienced hypoglycaemia were similar. Analysis of several demographic and baseline clinical variables revealed no consistent correlations with response to saxagliptin. ConclusionsWhether receiving saxagliptin as an add-on therapy to glyburide, a thiazolidinedione, or metformin or in initial combination with metformin, a greater percentage of patients achieve clinically relevant large reductions in HbA1c vs. comparator, with a low incidence of hypoglycaemia. PMID:23795975

Factors associated with the recruitment and retention of social workers in Wales: employer and employee perspectives.

PubMed

Evans, Sherrill; Huxley, Peter

2009-05-01

Despite acute staffing shortages in social work, workforce planning within the UK social care sector is compromised by poor workforce intelligence. This study aimed to inform the evidence base providing new data on recruitment and retention in Wales, examining what personal and organizational characteristics are associated with intentions to leave, and what initiatives or incentives might mediate that effect. A multi-method design facilitated comparisons between two data sources--a census of all 22 Welsh local authority employers about recruitment and retention practices and a survey of all social workers and senior practitioners employed in social services (n = 998; response rate 45.9%) about demography, workforce characteristics, working patterns, morale and plans and reasons for leaving one's job. Vacancy (mean 14.4%) and turnover (mean 15%) rates were statistically significantly higher in children's services than in adult services; vacancy rates were also higher in authorities that offered higher starting salaries. The provision of certain types of traineeship might also be associated with higher vacancy rates but these results should be treated with some caution. There was little evidence that recruitment and retention initiatives were associated with lower vacancy or turnover rates, despite employers' perceptions about their effectiveness. Social workers derived a lot of satisfaction from their work, but more than a quarter wanted to leave their job within 6 months, and almost as many were actively seeking alternative employment. Intention to leave was explained by job and employer satisfaction, and negative feelings about pay. Senior practitioners and staff members with longer lengths of service were less likely to want to leave, even if they were dissatisfied with their job or employer. Job and employer dissatisfaction was associated with retention initiatives related to facilities, good caseload management and home-working, suggesting that dissatisfied staff might remain in employment for longer if these initiatives were in place.

Deformation Behavior of a Coarse-Grained Mg-8Al-1.5Ca-0.2Sr Magnesium Alloy at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Lou, Yan; Liu, Xiao

2018-02-01

The compression tests were carried out on a coarse-grained Mg-8Al-1.5Ca-0.2Sr magnesium alloy samples at temperatures from 300 to 450 °C and strain rates from 0.001 to 10 s-1. The flow stress curves were analyzed using the double-differentiation method, and double minima were detected on the flow curves. The first set of minima is shown to identify the critical strain for twinning, while the second set indicates the critical strain for the initiation of dynamic recrystallization (DRX). Twin variant selection was numerically identified by comprehensive analysis of the Schmid factors for different deformation modes and the accommodation strains imposed on neighboring grains. It was found that twinning is initiated before DRX. Dynamic recrystallization volume increases with strain rate at a given deformation temperature. At high strain rate, various twin variants are activated to accommodate deformation, leading to the formation of twin intersections and high DRX volume. Fully dynamic recrystallized structure can be obtained at both high and low strain rates due to the high mobility of the grain and twin boundaries at the temperature of 400 °C.

Prognostic value of heart rate turbulence for risk assessment in patients with unstable angina and non-ST elevation myocardial infarction

PubMed Central

Harris, Patricia RE; Stein, Phyllis K; Fung, Gordon L; Drew, Barbara J

2013-01-01

Background We sought to examine the prognostic value of heart rate turbulence derived from electrocardiographic recordings initiated in the emergency department for patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina. Methods Twenty-four-hour Holter recordings were started in patients with cardiac symptoms approximately 45 minutes after arrival in the emergency department. Patients subsequently diagnosed with NSTEMI or unstable angina who had recordings with ≥18 hours of sinus rhythm and sufficient data to compute Thrombolysis In Myocardial Infarction (TIMI) risk scores were chosen for analysis (n = 166). Endpoints were emergent re-entry to the cardiac emergency department and/or death at 30 days and one year. Results In Cox regression models, heart rate turbulence and TIMI risk scores together were significant predictors of 30-day (model chi square 13.200, P = 0.001, C-statistic 0.725) and one-year (model chi square 31.160, P < 0.001, C-statistic 0.695) endpoints, outperforming either measure alone. Conclusion Measurement of heart rate turbulence, initiated upon arrival at the emergency department, may provide additional incremental value in the risk assessment for patients with NSTEMI or unstable angina. PMID:23976860

Towards adjoint-based inversion of time-dependent mantle convection with nonlinear viscosity

NASA Astrophysics Data System (ADS)

Li, Dunzhu; Gurnis, Michael; Stadler, Georg

2017-04-01

We develop and study an adjoint-based inversion method for the simultaneous recovery of initial temperature conditions and viscosity parameters in time-dependent mantle convection from the current mantle temperature and historic plate motion. Based on a realistic rheological model with temperature-dependent and strain-rate-dependent viscosity, we formulate the inversion as a PDE-constrained optimization problem. The objective functional includes the misfit of surface velocity (plate motion) history, the misfit of the current mantle temperature, and a regularization for the uncertain initial condition. The gradient of this functional with respect to the initial temperature and the uncertain viscosity parameters is computed by solving the adjoint of the mantle convection equations. This gradient is used in a pre-conditioned quasi-Newton minimization algorithm. We study the prospects and limitations of the inversion, as well as the computational performance of the method using two synthetic problems, a sinking cylinder and a realistic subduction model. The subduction model is characterized by the migration of a ridge toward a trench whereby both plate motions and subduction evolve. The results demonstrate: (1) for known viscosity parameters, the initial temperature can be well recovered, as in previous initial condition-only inversions where the effective viscosity was given; (2) for known initial temperature, viscosity parameters can be recovered accurately, despite the existence of trade-offs due to ill-conditioning; (3) for the joint inversion of initial condition and viscosity parameters, initial condition and effective viscosity can be reasonably recovered, but the high dimension of the parameter space and the resulting ill-posedness may limit recovery of viscosity parameters.

Training with video imaging improves the initial intubation success rates of paramedic trainees in an operating room setting.

PubMed

Levitan, R M; Goldman, T S; Bryan, D A; Shofer, F; Herlich, A

2001-01-01

Video imaging of intubation as seen by the laryngoscopist has not been a part of traditional instruction methods, and its potential impact on novice intubation success rates has not been evaluated. We prospectively tracked the success rates of novice intubators in paramedic classes who were required to watch a 26-minute instructional videotape made with a direct laryngoscopy imaging system (video group). We compared the prospectively obtained intubation success rate of the video group against retrospectively collected data from prior classes of paramedic students (traditional group) in the same training program. All classes received the same didactic airway instruction, same mannequin practice time, same paramedic textbook, and were trained in the same operating room with the same teaching staff. The traditional group (n=113, total attempts 783) had a mean individual intubation success rate of 46.7% (95% confidence interval 42.2% to 51.3%). The video group (n=36, total attempts 102) had a mean individual intubation success rate of 88.1% (95% confidence interval 79.6% to 96.5%). The difference in mean intubation success rates between the 2 groups was 41.4% (95% confidence interval 31.1% to 50.7%, P <.0001). The 2 groups did not differ in respect to age, male sex, or level of education. An instructional videotape made with the direct laryngoscopy video system significantly improved the initial success rates of novice intubators in an operating room setting.

Dynamics of gas cell coalescence during baking expansion of leavened dough.

PubMed

Miś, Antoni; Nawrocka, Agnieszka; Lamorski, Krzysztof; Dziki, Dariusz

2018-01-01

The investigation of the dynamics of gas cell coalescence, i.e. a phenomenon that deteriorates the homogeneity of the cellular structure of bread crumb, was carried out performing simultaneously measurements of the dough volume, pressure, and viscosity. It was demonstrated that, during the baking expansion of chemically leavened wheat flour dough, the maximum growth rate of the gas cell radius determined from the ratio of pressure exerted by the expanded dough to its viscosity was on average four-fold lower than that calculated from volume changes in the gas phase of the dough. Such a high discrepancy was interpreted as a result of the course of coalescence, and a formula for determination of its rate was developed. The coalescence rate in the initial baking expansion phase had negative values, indicating nucleation of newly formed gas cells, which increased the number of gas cells even by 8%. In the next baking expansion phase, the coalescence rate started to exhibit positive values, reflecting dominance of the coalescence phenomenon over nucleation. The maximum coalescence rates indicate that, during the period of the most intensive dough expansion, the number of gas cells decreased by 2-3% within one second. At the end of the formation of bread crumb, the number of the gas cells declined by 55-67% in comparison with the initial value. The correctness of the results was positively verified using X-ray micro-computed tomography. The developed method can be a useful tool for more profound exploration of the coalescence phenomenon at various stages of evolution of the cellular structure and its determinants, which may contribute to future development of more effective methods for improving the texture and sensory quality of bread crumb. Copyright © 2017 Elsevier Ltd. All rights reserved.

Current state of biomarker development for clinical application in epithelial ovarian cancer

PubMed Central

Moore, Richard G.; MacLaughlan, Shannon; Bast, Robert C.

2011-01-01

Each year in the United States over 15,000 women die of epithelial ovarian cancer (EOC)and 22,000 are diagnosed with the disease. The incidence of ovarian cancer has remained stable over the past decade however, survival rates have improved steadily. Increases in survival rates can be attributed to the advances in surgical management, development of effective cytotoxic drugs and the route of administration of chemotherapy. Ovarian cancer survival rates could also be improved through screening and early detection. Disappointingly, effective screening methods have not been established and continue to be elusive. Historically the goal of a screening test was to achieve a positive predictive value (PPV) greater than 10% in order be considered cost effective and have an acceptable risk for the population being screened. Despite the inability of currently available screening algorithms to achieve the desired PPV there may be an advantage in producing a stage migration to lower stages at the time of diagnoses, thereby resulting in improved survival. Equally important recent studies have demonstrated that women who have their initial surgery performed by gynecologic oncologists, and women who have their surgeries at centers experienced in the treatment of ovarian cancer have higher survival rates. For these reasons it is essential that all women at high risk for ovarian cancer receive their initial care by gynecologic oncologists and at centers with multidisciplinary teams experienced in the optimal care of ovarian cancer patients. With this in mind, methods that facilitate the accurate triage of women who will ultimately be diagnosed with ovarian cancer could play a significant role in improving survival rates for these patients. This review article will examine the current state of biomarker use in ovarian cancer screening, risk assessment and for monitoring ovarian cancer patients. PMID:19879639

Treatment of Ammonia Nitrogen Wastewater in Low Concentration by Two-Stage Ozonization.

PubMed

Luo, Xianping; Yan, Qun; Wang, Chunying; Luo, Caigui; Zhou, Nana; Jian, Chensheng

2015-09-23

Ammonia nitrogen wastewater (about 100 mg/L) was treated by two-stage ozone oxidation method. The effects of ozone flow rate and initial pH on ammonia removal were studied, and the mechanism of ammonia nitrogen removal by ozone oxidation was discussed. After the primary stage of ozone oxidation, the ammonia removal efficiency reached 59.32% and pH decreased to 6.63 under conditions of 1 L/min ozone flow rate and initial pH 11. Then, the removal efficiency could be over 85% (the left ammonia concentration was lower than 15 mg/L) after the second stage, which means the wastewater could have met the national discharge standards of China. Besides, the mechanism of ammonia removal by ozone oxidation was proposed by detecting the products of the oxidation: ozone oxidation directly and ·OH oxidation; ammonia was mainly transformed into NO₃(-)-N, less into NO₂(-)-N, not into N₂.

State-specific tunneling lifetimes from classical trajectories: H-atom dissociation in electronically excited pyrrole

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

Xie, Weiwei; Domcke, Wolfgang; Farantos, Stavros C.

A trajectory method of calculating tunneling probabilities from phase integrals along straight line tunneling paths, originally suggested by Makri and Miller [J. Chem. Phys. 91, 4026 (1989)] and recently implemented by Truhlar and co-workers [Chem. Sci. 5, 2091 (2014)], is tested for one- and two-dimensional ab initio based potentials describing hydrogen dissociation in the {sup 1}B{sub 1} excited electronic state of pyrrole. The primary observables are the tunneling rates in a progression of bending vibrational states lying below the dissociation barrier and their isotope dependences. Several initial ensembles of classical trajectories have been considered, corresponding to the quasiclassical and themore » quantum mechanical samplings of the initial conditions. It is found that the sampling based on the fixed energy Wigner density gives the best agreement with the quantum mechanical dissociation rates.« less

Importance of size and distribution of Ni nanoparticles for the hydrodeoxygenation of microalgae oil.

PubMed

Song, Wenji; Zhao, Chen; Lercher, Johannes A

2013-07-22

Improved synthetic approaches for preparing small-sized Ni nanoparticles (d=3 nm) supported on HBEA zeolite have been explored and compared with the traditional impregnation method. The formation of surface nickel silicate/aluminate involved in the two precipitation processes are inferred to lead to the stronger interaction between the metal and the support. The lower Brønsted acid concentrations of these two Ni/HBEA catalysts compared with the parent zeolite caused by the partial exchange of Brønsted acid sites by Ni(2+) cations do not influence the hydrodeoxygenation rates, but alter the product selectivity. Higher initial rates and higher stability have been achieved with these optimized catalysts for the hydrodeoxygenation of stearic acid and microalgae oil. Small metal particles facilitate high initial catalytic activity in the fresh sample and size uniformity ensures high catalyst stability. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Cole, K.C.; Noel, D.; Hechler, J.J.

Data are presented on physicochemical tests carried out on room-temperature aged samples of a commercially available carbon-epoxy composite prepreg system. The analytical methods used included Fourier transform IR (FTIR) spectroscopy, reverse-phase liquid chromatography (RPLC), high-speed RPLC, high-performance size-exclusion chromatography, differential scanning calorimetry and thermogravimetry, and pyrolysis/gas chromatography. All data indicated significant changes in these samples due to aging, with the most sensitive indices being those of FTIR and RPLC procedures. Results indicate that the number of unreacted epoxy groups decreased steadily at a rate of 0.34 percent per day, based on the initial amount, and the number of free amine-hardenermore » molecules decreased at a rate of 1.05 percent per day. The amount of initial epoxy-amine reaction product increased significantly over the first 30 days, but then declined, due to further reactions of these to give higher-molecular-weight products. 23 refs.« less

Nonlinear stress waves in a perfectly flexible string. [for aerodynamic decelerating system

NASA Technical Reports Server (NTRS)

Fan, D.-N.; Mcgarvey, J. F.

1977-01-01

This paper discusses nonlinear stress-wave propagation in a perfectly flexible string obeying a quasilinear (rate-dependent) constitutive equation. Wave speeds and compatibility relations valid along various families of characteristics were determined. It was shown that the compatibility relations associated with the transverse as well as the longitudinal waves readily yield a physical interpretation when they are expressed in suitable variables and in vector form. Coding based on the present information was completed for the machine solution of a class of mixed initial- and boundary-value problems of practical interest. Computer simulation of the stress-wave interaction in the 40-foot lanyard in the Arcas 'Rocoz' system during deployment was carried out using a stress-strain relation for nylon at the strain rate of 30/second. A method for estimating the maximum tension and strain in a string during the initial loading phase is proposed.

Optimization of cell seeding in a 2D bio-scaffold system using computational models.

PubMed

Ho, Nicholas; Chua, Matthew; Chui, Chee-Kong

2017-05-01

The cell expansion process is a crucial part of generating cells on a large-scale level in a bioreactor system. Hence, it is important to set operating conditions (e.g. initial cell seeding distribution, culture medium flow rate) to an optimal level. Often, the initial cell seeding distribution factor is neglected and/or overlooked in the design of a bioreactor using conventional seeding distribution methods. This paper proposes a novel seeding distribution method that aims to maximize cell growth and minimize production time/cost. The proposed method utilizes two computational models; the first model represents cell growth patterns whereas the second model determines optimal initial cell seeding positions for adherent cell expansions. Cell growth simulation from the first model demonstrates that the model can be a representation of various cell types with known probabilities. The second model involves a combination of combinatorial optimization, Monte Carlo and concepts of the first model, and is used to design a multi-layer 2D bio-scaffold system that increases cell production efficiency in bioreactor applications. Simulation results have shown that the recommended input configurations obtained from the proposed optimization method are the most optimal configurations. The results have also illustrated the effectiveness of the proposed optimization method. The potential of the proposed seeding distribution method as a useful tool to optimize the cell expansion process in modern bioreactor system applications is highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.

Code of Federal Regulations, 2011 CFR

2011-10-01

... predetermined rate of speed exceeded. 236.503 Section 236.503 Transportation Other Regulations Relating to... § 236.503 Automatic brake application; initiation when predetermined rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when the speed of...

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.

Code of Federal Regulations, 2010 CFR

2010-10-01

... predetermined rate of speed exceeded. 236.503 Section 236.503 Transportation Other Regulations Relating to... § 236.503 Automatic brake application; initiation when predetermined rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when the speed of...

Mechanistic and kinetic investigation on OH-initiated oxidation of tetrabromobisphenol A.

PubMed

He, Maoxia; Li, Xin; Zhang, Shiqing; Sun, Jianfei; Cao, Haijie; Wang, Wenxing

2016-06-01

Detailed mechanism of the OH-initiated transformation of tetrabromobisphenol A (TBBPA) has been investigated by quantum chemical methods in this paper. Abstraction reactions of hydrogen atoms from the OH groups and CH3 groups of TBBPA are the dominant pathways of the initial reactions. The produced phenolic-type radical and alkyl-type radical may transfer to 4,4'-(ethene-1,1-diyl)bis(2,6-dibromophenol), 4-acetyl-2,6-dibromophenol and 2,6-dibromobenzoquinone at high temperature. In water, major products are 2,6-dibromo-p-hydroquinone, 4-isopropylene-2,6-dibromophenol and 4-(2-hydroxyisopropyl)-2,6-dibromophenol resulting from the addition reactions. Total rate constants of the initial reaction are 1.02 × 10(-12) cm(3) molecule(-1) s(-1) in gas phase and 1.93 × 10(-12) cm(3) molecule(-1) s(-1) in water at 298 K. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validating Whole-Airway CFD Predictions of DPI Aerosol Deposition at Multiple Flow Rates

PubMed Central

Tian, Geng; Khajeh-Hosseini-Dalasm, Navvab; Hindle, Michael

2016-01-01

Abstract Background: The objective of this study was to compare aerosol deposition predictions of a new whole-airway CFD model with available in vivo data for a dry powder inhaler (DPI) considered across multiple inhalation waveforms, which affect both the particle size distribution (PSD) and particle deposition. Methods: The Novolizer DPI with a budesonide formulation was selected based on the availability of 2D gamma scintigraphy data in humans for three different well-defined inhalation waveforms. Initial in vitro cascade impaction experiments were conducted at multiple constant (square-wave) particle sizing flow rates to characterize PSDs. The whole-airway CFD modeling approach implemented the experimentally determined PSDs at the point of aerosol formation in the inhaler. Complete characteristic airway geometries for an adult were evaluated through the lobar bronchi, followed by stochastic individual pathway (SIP) approximations through the tracheobronchial region and new acinar moving wall models of the alveolar region. Results: It was determined that the PSD used for each inhalation waveform should be based on a constant particle sizing flow rate equal to the average of the inhalation waveform's peak inspiratory flow rate (PIFR) and mean flow rate [i.e., AVG(PIFR, Mean)]. Using this technique, agreement with the in vivo data was acceptable with <15% relative differences averaged across the three regions considered for all inhalation waveforms. Defining a peripheral to central deposition ratio (P/C) based on alveolar and tracheobronchial compartments, respectively, large flow-rate-dependent differences were observed, which were not evident in the original 2D in vivo data. Conclusions: The agreement between the CFD predictions and in vivo data was dependent on accurate initial estimates of the PSD, emphasizing the need for a combination in vitro–in silico approach. Furthermore, use of the AVG(PIFR, Mean) value was identified as a potentially useful method for characterizing a DPI aerosol at a constant flow rate. PMID:27082824

Experimental design data for the biosynthesis of citric acid using Central Composite Design method.

PubMed

Kola, Anand Kishore; Mekala, Mallaiah; Goli, Venkat Reddy

2017-06-01

In the present investigation, we report that statistical design and optimization of significant variables for the microbial production of citric acid from sucrose in presence of filamentous fungi A. niger NCIM 705. Various combinations of experiments were designed with Central Composite Design (CCD) of Response Surface Methodology (RSM) for the production of citric acid as a function of six variables. The variables are; initial sucrose concentration, initial pH of medium, fermentation temperature, incubation time, stirrer rotational speed, and oxygen flow rate. From experimental data, a statistical model for this process has been developed. The optimum conditions reported in the present article are initial concentration of sucrose of 163.6 g/L, initial pH of medium 5.26, stirrer rotational speed of 247.78 rpm, incubation time of 8.18 days, fermentation temperature of 30.06 °C and flow rate of oxygen of 1.35 lpm. Under optimum conditions the predicted maximum citric acid is 86.42 g/L. The experimental validation carried out under the optimal values and reported citric acid to be 82.0 g/L. The model is able to represent the experimental data and the agreement between the model and experimental data is good.

Impact of Introducing the Line Probe Assay on Time to Treatment Initiation of MDR-TB in Delhi, India

PubMed Central

Singla, Neeta; Satyanarayana, Srinath; Sachdeva, Kuldeep Singh; Van den Bergh, Rafael; Reid, Tony; Tayler-Smith, Katherine; Myneedu, V. P.; Ali, Engy; Enarson, Donald A.; Behera, Digamber; Sarin, Rohit

2014-01-01

Setting National Institute of Tuberculosis and Respiratory Diseases (erstwhile Lala Ram Sarup Institute) in Delhi, India. Objectives To evaluate before and after the introduction of the line Probe Assay (LPA) a) the overall time to MDR-TB diagnosis and treatment initiation; b) the step-by-step time lapse at each stage of patient management; and c) the lost to follow-up rates. Methods A retrospective cohort analysis was done using data on MDR-TB patients diagnosed during 2009–2012 under Revised National Tuberculosis Control Programme at the institute. Results Following the introduction of the LPA in 2011, the overall median time from identification of patients suspected for MDR-TB to the initiation of treatment was reduced from 157 days (IQR 127–200) to 38 days (IQR 30–79). This reduction was attributed mainly to a lower diagnosis time at the laboratory. Lost to follow-up rates were also significantly reduced after introduction of the LPA (12% versus 39% pre-PLA). Conclusion Introduction of the LPA was associated with a major reduction in the delay between identification of patients suspected for MDR-TB and initiation of treatment, attributed mainly to a reduction in diagnostic time in the laboratory. PMID:25058124

Smear Conversion, Treatment Outcomes and the Time of Default in Registered Tuberculosis Patients on RNTCP DOTS in Puducherry, Southern India

PubMed Central

Jayakumar, Niranjana; Gnanasekaran, Dhivyalakshmi

2014-01-01

Background: Revised National Tuberculosis Control Programme (RNTCP) in India has achieved improved cure rates. Objectives: This study describes the achievements under RNTCP in terms of conversion rates, treatment outcomes and pattern of time of default in patients on directly observed short-course treatment for Tuberculosis in Puducherry, Southern India. Settings: Retrospective cohort study; Tuberculosis Unit in District Tuberculosis Centre, Puducherry, India. Materials and Methods: Cohort analysis of patients of registered at the Tuberculosis Unit during 1st and 2nd quarter of the year 2011. Details about sputum conversion, treatment outcome and time of default were obtained from the tuberculosis register. Statistical Analysis: Kaplan-Meier plots & log rank tests. Results: RNTCP targets with respect to success rate (85.7%), death rate (2.7%) and failure rate (2.1%) in new cases have been achieved but the sputum conversion rate (88%) and default rate (5.9%) targets have not been achieved. The overall default rate for all registered TB patients was 7.4%; significantly higher in category II. In retreatment cases registered as treatment after default, the default rate was high (9%). The cumulative default rate; though similar in the initial two months of treatment; was consistently higher in category II as compared to that in category I. Nearly 40% of all defaulters interrupted treatment between the second and fourth month after treatment initiation. Conclusion: Defaulting from treatment is more common among the retreatment cases and usually occurs during the transition phase from intensive phase to continuation phase. PMID:25478371

Measuring and improving cervical, breast, and colorectal cancer screening rates in a multi-site urban practice in Toronto, Canada.

PubMed

Feldman, Joshua; Davie, Sam; Kiran, Tara

2017-01-01

Our Family Health Team is located in Toronto, Canada and provides care to over 35 000 patients. Like many practices in Canada, we took an opportunistic approach to cervical, breast, and colorectal cancer screening. We wanted to shift to a proactive, population-based approach but were unable to systematically identify patients overdue for screening or calculate baseline screening rates. Our initiative had two goals: (1) to develop a method for systematically identifying patients eligible for screening and whether they were overdue and (2) to increase screening rates for cervical, breast, and colorectal cancer. Using external government data in combination with our practice's electronic medical record, we developed a process to identify patients eligible and overdue for cancer screening. After generating baseline data, we implemented an evidence-based, multifaceted intervention to improve cancer screening rates. We sent a personalized reminder letter to overdue patients, provided physicians with practice-level audit and feedback, and improved our electronic reminder function by updating charts with accurate data on the Fecal Occult Blood Test (FOBT). Following our initial intervention, we sought to maintain and further improve our screening rates by experimenting with alternative recall methods and collecting patient feedback. Screening rates significantly improved for all three cancers. Between March 2014 and December 2016, the cervical cancer screening rate increased from 60% to 71% (p<0.05), the breast cancer screening rate increased from 56% to 65% (p<0.05), and the overall colorectal screening rate increased from 59% to 70% (p<0.05). The increase in colorectal screening rates was largely due to an increase in FOBT screening from 18% to 25%, while colonoscopy screening remained relatively unchanged, shifting from 45% to 46%. We also found that patients living in low income neighbourhoods were less likely to be screened. Following our intervention, this equity gap narrowed modestly for breast and colorectal cancer but did not change for cervical cancer screening. Our future improvement efforts will be focused on reducing the gap in screening between patients living in low-income and high-income neighbourhoods while maintaining overall gains.

Treatment of caries in relation to lesion severity: implications for minimum intervention dentistry.

PubMed

Brennan, D S; Balasubramanian, M; Spencer, A J

2015-01-01

To date there is little evidence of minimum intervention in relation to treatment patterns, particularly for initial carious lesions. The objective of this study was to investigate treatment provided to patients with a main diagnosis of coronal caries in relation to the severity of the caries lesion. A random sample of Australian dentists was surveyed by mailed questionnaires in 2009-2010 (response rate 67%). Data on services, patient characteristics and main diagnosis were collected from a service log. Models of service rates adjusted for age, sex, insurance status and reason for visit showed that compared to the reference category of gross caries lesions, there were higher rates [rate ratio, 95% CI] of restorative services for initial [1.63, 1.31-2.03] and cavitated [1.69, 1.39-2.05] lesions, higher rates of prophylaxis for initial [3.77, 2.09-6.79] and cavitated [3.88, 2.29-6.58] lesions, lower rates of endodontic services for initial [0.07, 0.02-0.30] and cavitated [0.11, 0.04-0.30] lesions, and lower rates of extraction for initial [0.15, 0.06-0.34] and cavitated [0.15, 0.07-0.31] lesions. Treatment of coronal caries was characterized by high rates of restorative services, but gross lesions had lower restorative rates and higher rates of endodontic and extraction services. There was little differentiation in treatment of coronal caries between initial and cavitated lesions, suggesting scope for increased management of initial carious lesions by the adoption of more minimum intervention approaches. Copyright © 2014 Elsevier Ltd. All rights reserved.

Initial high anti-emetic efficacy of granisetron with dexamethasone is not maintained over repeated cycles.

PubMed Central

de Wit, R.; van den Berg, H.; Burghouts, J.; Nortier, J.; Slee, P.; Rodenburg, C.; Keizer, J.; Fonteyn, M.; Verweij, J.; Wils, J.

1998-01-01

We have reported previously that the anti-emetic efficacy of single agent 5HT3 antagonists is not maintained when analysed with the measurement of cumulative probabilities. Presently, the most effective anti-emetic regimen is a combination of a 5HT3 antagonist plus dexamethasone. We, therefore, assessed the sustainment of efficacy of such a combination in 125 patients, scheduled to receive cisplatin > or = 70 mg m(-2) either alone or in combination with other cytotoxic drugs. Anti-emetic therapy was initiated with 10 mg of dexamethasone and 3 mg of granisetron intravenously, before cisplatin. On days 1-6, patients received 8 mg of dexamethasone and 1 mg of granisetron twice daily by oral administration. Protection was assessed during all cycles and calculated based on cumulative probability analyses using the method of Kaplan-Meier and a model for transitional probabilities. Irrespective of the type of analysis used, the anti-emetic efficacy of granisetron/dexamethasone decreased over cycles. The initial complete acute emesis protection rate of 66% decreased to 30% according to the method of Kaplan-Meier and to 39% using the model for transitional probabilities. For delayed emesis, the initial complete protection rate of 52% decreased to 21% (Kaplan-Meier) and to 43% (transitional probabilities). In addition, we observed that protection failure in the delayed emesis period adversely influenced the acute emesis protection in the next cycle. We conclude that the anti-emetic efficacy of a 5HT3 antagonist plus dexamethasone is not maintained over multiple cycles of highly emetogenic chemotherapy, and that the acute emesis protection is adversely influenced by protection failure in the delayed emesis phase. PMID:9652766

Green Building Premium Cost Analysis in Indonesia Using Work Breakdown Structure Method

NASA Astrophysics Data System (ADS)

Basten, V.; Latief, Y.; Berawi, M. A.; Riswanto; Muliarto, H.

2018-03-01

The concept of green building in the construction industry is indispensable for mitigating environmental issues such as waste, pollution, and carbon emissions. There are some countries that have Green Building rating tools. Indonesia particularly is the country which has Greenship rating tools but the number of Green Building is relatively low. Development of building construction is depended on building investors or owner initiation, so this research is conducted to get the building aspects that have significant effect on the attractiveness using The Green Building Concept. The method in this research is work breakdown structure method that detailing the green building activities. The particular activities will be processed to get the cost elements for the green building achievement that it was targeted to improve better than conventional building. The final result of the study was a very significant work package on green building construction in the city of Indonesia case study.

Reducing microwave absorption with fast frequency modulation.

PubMed

Qin, Juehang; Hubler, A

2017-05-01

We study the response of a two-level quantum system to a chirp signal, using both numerical and analytical methods. The numerical method is based on numerical solutions of the Schrödinger solution of the two-level system, while the analytical method is based on an approximate solution of the same equations. We find that when two-level systems are perturbed by a chirp signal, the peak population of the initially unpopulated state exhibits a high sensitivity to frequency modulation rate. We also find that the aforementioned sensitivity depends on the strength of the forcing, and weaker forcings result in a higher sensitivity, where the frequency modulation rate required to produce the same reduction in peak population would be lower. We discuss potential applications of this result in the field of microwave power transmission, as it shows applying fast frequency modulation to transmitted microwaves used for power transmission could decrease unintended absorption of microwaves by organic tissue.

The Impact of Graduate First Project on Students with Disabilities: Perceptions of Key Personnel

ERIC Educational Resources Information Center

Foley, Tamera Garrett

2012-01-01

The Graduate First initiative was implemented to address the dropout crisis among students with disabilities in the state of Georgia, who continue to demonstrate a rate of attrition twice that of their non-disabled peers (Georgia Department of Education [GA DOE], 2010). This mixed method case study explored the perceptions and experiences of a…

40 CFR 63.7322 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2011 CFR

2011-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... rate of particulate matter (lb/ton of coke) from a control device applied to pushing emissions where a... combined weight in tons of coke pushed during the duration of each test run according to the procedures in...

40 CFR 63.7322 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2010 CFR

2010-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... rate of particulate matter (lb/ton of coke) from a control device applied to pushing emissions where a... combined weight in tons of coke pushed during the duration of each test run according to the procedures in...

40 CFR 63.7322 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2012 CFR

2012-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... rate of particulate matter (lb/ton of coke) from a control device applied to pushing emissions where a... combined weight in tons of coke pushed during the duration of each test run according to the procedures in...

40 CFR 63.7322 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2014 CFR

2014-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... rate of particulate matter (lb/ton of coke) from a control device applied to pushing emissions where a... combined weight in tons of coke pushed during the duration of each test run according to the procedures in...

40 CFR 63.7322 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2013 CFR

2013-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... rate of particulate matter (lb/ton of coke) from a control device applied to pushing emissions where a... combined weight in tons of coke pushed during the duration of each test run according to the procedures in...

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

Podlivaev, A. I., E-mail: AIPodlivayev@mephi.ru; Openov, L. A.

The initial stage of hydrogen desorption from fully hydrogenated carbon nanotubes (3.0) and (2.2) is numerically studied by the molecular dynamics method. The temperature dependence of the desorption rate is directly determined at T = 1800–2500 K. The characteristic desorption times are determined at temperatures outside this range by extrapolation. It is shown that hydrogen desorption leads to the appearance of electronic states in the band gap.

Development of an Educational Video to Improve Patient Knowledge and Communication with Their Healthcare Providers about Colorectal Cancer Screening

ERIC Educational Resources Information Center

Katz, Mira L.; Heaner, Sarah; Reiter, Paul; van Putten, Julie; Murray, Lee; McDougle, Leon; Cegala, Donald J.; Post, Douglas; David, Prabu; Slater, Michael; Paskett, Electra D.

2009-01-01

Background: Low rates of colorectal cancer (CRC) screening persist due to individual, provider, and system level barriers. Purpose: To develop and obtain initial feedback about a CRC screening educational video from community members and medical professionals. Methods: Focus groups of patients were conducted prior to the development of the CRC…

Big plans.

PubMed

Fitch, Kevin F; Doyle, James F

2005-09-01

In Elmhurst Memorial Healthcare's capital planning method: Future replacement costs of assets are estimated by inflating their historical cost over their lives. A balanced model is created initially based on the assumption that rates of revenue growth, inflation, investment income, and interest expense are all equal. Numbers then can be adjusted to account for possible variations, such as excesses or shortages in investment or debt balances.

Human Papillomavirus (HPV) Risk Factors, Vaccination Patterns, and Vaccine Perceptions among a Sample of Male College Students

ERIC Educational Resources Information Center

Fontenot, Holly B.; Collins Fantasia, Heidi; Charyk, Anna; Sutherland, Melissa A.

2014-01-01

Objective: To examine human papillomavirus (HPV) vaccination rates, including initiation and completion of the vaccine series, and barriers to vaccination in a sample of male college students. Participants: Male students between the ages of 18 and 25 who reported being currently or previously sexually active (N = 735). Methods: A cross-sectional…

Use of the "Intervention Selection Profile-Social Skills" to Identify Social Skill Acquisition Deficits: A Preliminary Validation Study

ERIC Educational Resources Information Center

Kilgus, Stephen P.; von der Embse, Nathaniel P.; Scott, Katherine; Paxton, Sara

2015-01-01

The purpose of this investigation was to develop and initially validate the "Intervention Selection Profile-Social Skills" (ISP-SS), a novel brief social skills assessment method intended for use at Tier 2. Participants included 54 elementary school teachers and their 243 randomly selected students. Teachers rated students on two rating…

Firefly

DTIC Science & Technology

2012-05-29

Hunter College has completed work on baseline measurements of relaxation times for pentacene at various temperatures in order to determine optimal...temperatures for measuring relaxation rate as a function of doping. We have also repeated these measurements on pentacene samples at 2 different...P3HT using a time-lag method. 2 Technical Accomplishments This Period Relaxation Measurements on Pentacene . As described initially in the 1Q

Multiple laser pulse ignition method and apparatus

DOEpatents

Early, James W.

1998-01-01

Two or more laser light pulses with certain differing temporal lengths and peak pulse powers can be employed sequentially to regulate the rate and duration of laser energy delivery to fuel mixtures, thereby improving fuel ignition performance over a wide range of fuel parameters such as fuel/oxidizer ratios, fuel droplet size, number density and velocity within a fuel aerosol, and initial fuel temperatures.

Unstructured and adaptive mesh generation for high Reynolds number viscous flows

NASA Technical Reports Server (NTRS)

Mavriplis, Dimitri J.

1991-01-01

A method for generating and adaptively refining a highly stretched unstructured mesh suitable for the computation of high-Reynolds-number viscous flows about arbitrary two-dimensional geometries was developed. The method is based on the Delaunay triangulation of a predetermined set of points and employs a local mapping in order to achieve the high stretching rates required in the boundary-layer and wake regions. The initial mesh-point distribution is determined in a geometry-adaptive manner which clusters points in regions of high curvature and sharp corners. Adaptive mesh refinement is achieved by adding new points in regions of large flow gradients, and locally retriangulating; thus, obviating the need for global mesh regeneration. Initial and adapted meshes about complex multi-element airfoil geometries are shown and compressible flow solutions are computed on these meshes.

From screen to structure with a harvestable microfluidic device.

PubMed

Stojanoff, Vivian; Jakoncic, Jean; Oren, Deena A; Nagarajan, V; Poulsen, Jens-Christian Navarro; Adams-Cioaba, Melanie A; Bergfors, Terese; Sommer, Morten O A

2011-08-01

Advances in automation have facilitated the widespread adoption of high-throughput vapour-diffusion methods for initial crystallization screening. However, for many proteins, screening thousands of crystallization conditions fails to yield crystals of sufficient quality for structural characterization. Here, the rates of crystal identification for thaumatin, catalase and myoglobin using microfluidic Crystal Former devices and sitting-drop vapour-diffusion plates are compared. It is shown that the Crystal Former results in a greater number of identified initial crystallization conditions compared with vapour diffusion. Furthermore, crystals of thaumatin and lysozyme obtained in the Crystal Former were used directly for structure determination both in situ and upon harvesting and cryocooling. On the basis of these results, a crystallization strategy is proposed that uses multiple methods with distinct kinetic trajectories through the protein phase diagram to increase the output of crystallization pipelines.

Application of excitation and emission matrix fluorescence (EEM) and UV-vis absorption to monitor the characteristics of Alizarin Red S (ARS) during electro-Fenton degradation process.

PubMed

Lai, Bo; Zhou, Yuexi; Wang, Juling; Yang, Zhishan; Chen, Zhiqiang

2013-11-01

Oxidative degradation of Alizarin Red S (ARS) in aqueous solutions by using electro-Fenton was studied. At first, effect of operating parameters such as current density, aeration rate and initial pH on the degradation of ARS were studied by using UV-vis spectrum, respectively. Then, under the optimal operating conditions (current density: 10.0mAcm(-2), aeration rate: 1000mLmin(-1), initial pH: 2.8), the identification of degradation products of ARS was carried out by using GC-MS and HPLC, meanwhile its degradation pathway was proposed according to the intermediates. Considering the location, intensity and intensity ratio of fluorescence center peak of the ARS in aqueous solution, a convenient and quick monitoring method by using excitation-emission matrix fluorescence spectrum technology was developed to monitor the degradation degree of ARS through electro-Fenton process. Furthermore, it is suggested that the developed method would be promising for the quick analysis and evaluation of the degradation degree of the pollutants with π-conjugated system. Copyright © 2013 Elsevier Ltd. All rights reserved.

What Makes a Successful Survey? A Systematic Review of Surveys Used in Anterior Cruciate Ligament Reconstruction.

PubMed

Ekhtiari, Seper; Kay, Jeffrey; de Sa, Darren; Simunovic, Nicole; Musahl, Volker; Peterson, Devin C; Ayeni, Olufemi R

2017-05-01

To characterize and assess the methodological quality of patient and physician surveys related to anterior cruciate ligament reconstruction, and to analyze the factors influencing response rate. The databases MEDLINE, Embase, and PubMed were searched from database inception to search date and screened in duplicate for relevant studies. Data regarding survey characteristics, response rates, and distribution methods were extracted. A previously published list of recommendations for high-quality surveys in orthopaedics was used as a scale to assess survey quality (12 items scored 0, 1, or 2; maximum score = 24). Of the initial 1,276 studies, 53 studies published between 1986 and 2016 met the inclusion criteria. Sixty-four percent of studies were distributed to physicians, compared with 32% distributed to patients and less than 4% to coaches. The median number of items in each survey was 10.5, and the average response rate was 73% (range: 18% to 100%). In-person distribution was the most common method (40%), followed by web-based methods (28%) and mail (25%). Response rates were highest for surveys targeted at patients (77%, P < .0001) and those delivered in-person (94%, P < .0001). The median quality score was 12/24 (range = 8.5/24 to 21/24). There was high inter-rater agreement using the quality scale (intraclass correlation coefficient = 0.92), but there was no correlation with the response rate (Rho = -0.01, P = .97). Response rates vary based on target audience and distribution methods, with patients responding at a significantly higher rate than physicians and in-person distribution yielding significantly higher response rates than web or mail surveys. Level IV, systematic review of Level IV studies. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Changes in breastfeeding initiation at hospital discharge between first and second births in Nova Scotia: a population-based cohort study

PubMed Central

Nix, Kimberley; Dodds, Linda

2017-01-01

Background: Breastfeeding has well-recognized health benefits for infants and mothers. However, little research has been conducted to investigate changes in breastfeeding from one pregnancy to another. This study was conducted to describe rates of breastfeeding initiation at hospital discharge for women's first and second births and to identify factors associated with changes in initiation at the second birth. Methods: We conducted a longitudinal, population-based cohort study involving women residing in Nova Scotia who delivered a first and second live-born singleton between 2007 and 2013. Separate analyses were conducted among women who breastfed their first infant and among women who did not breastfeed their first infant. Results: Of the 9643 (82.6%) mothers who initiated breastfeeding in the first birth, 973 (10.3%) did not initiate breastfeeding in the second birth. Of first-birth noninitiators, 526 (26.3%) initiated breastfeeding in the second birth. With the exception of smoking and cesarean births, factors that were associated with breastfeeding initiation in the second birth depended on breastfeeding initiation status in the first birth. These factors were associated with increased odds of not breastfeeding in the second birth among the subset of mothers who breastfed in the first birth, and decreased odds of breastfeeding in the second birth among the subset of mothers who did not breastfeed in the first birth. Interpretation: Most women continue the same method of infant feeding after their first and second births. Identifying factors associated with change in breastfeeding status between the first and second births may help to inform interventions for optimal breastfeeding initiation in the second birth. PMID:28401137

An instrumental variable approach finds no associated harm or benefit from early dialysis initiation in the United States

PubMed Central

Scialla, Julia J.; Liu, Jiannong; Crews, Deidra C.; Guo, Haifeng; Bandeen-Roche, Karen; Ephraim, Patti L.; Tangri, Navdeep; Sozio, Stephen M.; Shafi, Tariq; Miskulin, Dana C.; Michels, Wieneke M.; Jaar, Bernard G.; Wu, Albert W.; Powe, Neil R.; Boulware, L. Ebony

2014-01-01

The estimated glomerular filtration rate (eGFR) at dialysis initiation has been rising. Observational studies suggest harm, but may be confounded by unmeasured factors. As instrumental variable methods may be less biased we performed a retrospective cohort study of 310,932 patients starting dialysis between 2006 to 2008 and registered in the United States Renal Data System in order to describe geographic variation in eGFR at dialysis initiation and determine its association with mortality. Patients were grouped into 804 health service areas by zip code. Individual eGFR at dialysis initiation averaged 10.8 ml/min/1.73m2 but varied geographically. Only 11% of the variation in mean health service areas-level eGFR at dialysis initiation was accounted for by patient characteristics. We calculated demographic-adjusted mean eGFR at dialysis initiation in the health service areas using the 2006 and 2007 incident cohort as our instrument and estimated the association between individual eGFR at dialysis initiation and mortality in the 2008 incident cohort using the 2 stage residual inclusion method. Among 89,547 patients starting dialysis in 2008 with eGFR 5 to 20 ml/min/1.73m2, eGFR at initiation was not associated with mortality over a median of 15.5 months [hazard ratio 1.025 per 1 ml/min/1.73m2 for eGFR 5 to 14 ml/min/1.73m2; and 0.973 per 1 ml/min/1.73m2 for eGFR 14 to 20 ml/min/1.73m2]. Thus, there was no associated harm or benefit from early dialysis initiation in the United States. PMID:24786707

Tuberculosis Prevention in the Private Sector: Using Claims-Based Methods to Identify and Evaluate Latent Tuberculosis Infection Treatment With Isoniazid Among the Commercially Insured.

PubMed

Stockbridge, Erica L; Miller, Thaddeus L; Carlson, Erin K; Ho, Christine

Targeted identification and treatment of people with latent tuberculosis infection (LTBI) are key components of the US tuberculosis elimination strategy. Because of recent policy changes, some LTBI treatment may shift from public health departments to the private sector. To (1) develop methodology to estimate initiation and completion of treatment with isoniazid for LTBI using claims data, and (2) estimate treatment completion rates for isoniazid regimens from commercial insurance claims. Medical and pharmacy claims data representing insurance-paid services rendered and prescriptions filled between January 2011 and March 2015 were analyzed. Four million commercially insured individuals 0 to 64 years of age. Six-month and 9-month treatment completion rates for isoniazid LTBI regimens. There was an annual isoniazid LTBI treatment initiation rate of 12.5/100 000 insured persons. Of 1074 unique courses of treatment with isoniazid for which treatment completion could be assessed, almost half (46.3%; confidence interval, 43.3-49.3) completed 6 or more months of therapy. Of those, approximately half (48.9%; confidence interval, 44.5-53.3) completed 9 months or more. Claims data can be used to identify and evaluate LTBI treatment with isoniazid occurring in the commercial sector. Completion rates were in the range of those found in public health settings. These findings suggest that the commercial sector may be a valuable adjunct to more traditional venues for tuberculosis prevention. In addition, these newly developed claims-based methods offer a means to gain important insights and open new avenues to monitor, evaluate, and coordinate tuberculosis prevention.

Modeling of the static recrystallization for 7055 aluminum alloy by cellular automaton

NASA Astrophysics Data System (ADS)

Zhang, Tao; Lu, Shi-hong; Zhang, Jia-bin; Li, Zheng-fang; Chen, Peng; Gong, Hai; Wu, Yun-xin

2017-09-01

In order to simulate the flow behavior and microstructure evolution during the pass interval period of the multi-pass deformation process, models of static recovery (SR) and static recrystallization (SRX) by the cellular automaton (CA) method for the 7055 aluminum alloy were established. Double-pass hot compression tests were conducted to acquire flow stress and microstructure variation during the pass interval period. With the basis of the material constants obtained from the compression tests, models of the SR, incubation period, nucleation rate and grain growth were fitted by least square method. A model of the grain topology and a statistical computation of the CA results were also introduced. The effects of the pass interval time, temperature, strain, strain rate and initial grain size on the microstructure variation for the SRX of the 7055 aluminum alloy were studied. The results show that a long pass interval time, large strain, high temperature and large strain rate are beneficial for finer grains during the pass interval period. The stable size of the static recrystallized grain is not concerned with the initial grain size, but mainly depends on the strain rate and temperature. The SRX plays a vital role in grain refinement, while the SR has no effect on the variation of microstructure morphology. Using flow stress and microstructure comparisons of the simulated and experimental CA results, the established CA models can accurately predict the flow stress and microstructure evolution during the pass interval period, and provide guidance for the selection of optimized parameters for the multi-pass deformation process.

Crystallographic effects during radiative melting of semitransparent materials

NASA Astrophysics Data System (ADS)

Webb, B. W.; Viskanta, R.

1987-10-01

Experiments have been performed to illustrate crystallogrpahic effects during radiative melting of unconfined vertical layers of semitransparent material. Radiative melting of a polycrystalline paraffin was performed and the instantaneous layer weight and transmittance were measured using a cantilever beam technique and thermopile radiation detector, respectively. The effects of radiative flux, initial solid subcooling, spectral distribution of the irradiation, and crystal structure of the solid as determined qualitatively by the sample solidification rate were studied. Experimental results show conclusively the dominant influence of cystallographic effects in the form of multiple internal scattering of radiation during the melting process. A theoretical model is formulated to predict the melting rate of the material. Radiation transfer is treated by solving the one-dimensional radiative transfer equation for an absorbing-scattering medium using the discrete ordinates method. Melting rate and global layer reflectance as predicted by the model agree well with experimental data. Parametric studies conducted with the model illustrate the sensitivity of the melting behavior to such variables as incident radiative flux, initial layer opacity (material extinction coefficient), and scattering asymmetry factor.

Disease progression model in subjects with mild cognitive impairment from the Alzheimer's disease neuroimaging initiative: CSF biomarkers predict population subtypes

PubMed Central

Samtani, Mahesh N; Raghavan, Nandini; Shi, Yingqi; Novak, Gerald; Farnum, Michael; Lobanov, Victor; Schultz, Tim; Yang, Eric; DiBernardo, Allitia; Narayan, Vaibhav A

2013-01-01

AIM The objective is to develop a semi-mechanistic disease progression model for mild cognitive impairment (MCI) subjects. The model aims to describe the longitudinal progression of ADAS-cog scores from the Alzheimer's disease neuroimaging initiative trial that had data from 198 MCI subjects with cerebrospinal fluid (CSF) information who were followed for 3 years. METHOD Various covariates were tested on disease progression parameters and these variables fell into six categories: imaging volumetrics, biochemical, genetic, demographic, cognitive tests and CSF biomarkers. RESULTS CSF biomarkers were associated with both baseline disease score and disease progression rate in subjects with MCI. Baseline disease score was also correlated with atrophy measured using hippocampal volume. Progression rate was also predicted by executive functioning as measured by the Trail B-test. CONCLUSION CSF biomarkers have the ability to discriminate MCI subjects into sub-populations that exhibit markedly different rates of disease progression on the ADAS-cog scale. These biomarkers can therefore be utilized for designing clinical trials enriched with subjects that carry the underlying disease pathology. PMID:22534009

Radiation Damage Workshop

NASA Technical Reports Server (NTRS)

Stella, P. M.

1984-01-01

The availability of data regarding the radiation behavior of GaAs and silicon solar cells is discussed as well as efforts to provide sufficient information. Other materials are considered too immature for reasonable radiation evaluation. The lack of concern over the possible catastrophic radiation degradation in cascade cells is a potentially serious problem. Lithium counterdoping shows potential for removing damage in irradiated P-type material, although initial efficiencies are not comparable to current state of the art. The possibility of refining the lithium doping method to maintain high initial efficiencies and combining it with radiation tolerant structures such as thin BSF cells or vertical junction cells could provide a substantial improvement in EOL efficiencies. Laser annealing of junctions, either those formed ion implantation or diffusion, may not only improve initial cell performance but might also reduce the radiation degradation rate.

Quench dynamics in superconducting nanojunctions: Metastability and dynamical Yang-Lee zeros

NASA Astrophysics Data System (ADS)

Souto, R. Seoane; Martín-Rodero, A.; Yeyati, A. Levy

2017-10-01

We study the charge transfer dynamics following the formation of a phase or voltage biased superconducting nanojunction using a full counting statistics analysis. We demonstrate that the evolution of the zeros of the generating function allows one to identify the population of different many body states much in the same way as the accumulation of Yang-Lee zeros of the partition function in equilibrium statistical mechanics is connected to phase transitions. We give an exact expression connecting the dynamical zeros to the charge transfer cumulants and discuss when an approximation based on "dominant" zeros is valid. We show that, for generic values of the parameters, the system gets trapped into a metastable state characterized by a nonequilibrium population of the many body states which is dependent on the initial conditions. We study in particular the effect of the switching rates in the dynamics showing that, in contrast to intuition, the deviation from thermal equilibrium increases for the slower rates. In the voltage biased case the steady state is reached independent of the initial conditions. Our method allows us to obtain accurate results for the steady state current and noise in quantitative agreement with steady state methods developed to describe the multiple Andreev reflections regime. Finally, we discuss the system dynamics after a sudden voltage drop showing the possibility of tuning the many body states population by an appropriate choice of the initial voltage, providing a feasible experimental way to access the quench dynamics and control the state of the system.

Photocatalytic removal of doxycycline from aqueous solution using ZnO nano-particles: a comparison between UV-C and visible light.

PubMed

Pourmoslemi, Shabnam; Mohammadi, Ali; Kobarfard, Farzad; Amini, Mohsen

2016-10-01

Zinc oxide nano-particles were synthesized, characterized and used for photocatalytic degradation of doxycycline using UV-C and visible light. Effects of several operational factors including initial pH of antibiotic solution, initial antibiotic concentration and ZnO nano-particles loading amount were investigated. Comparing photocatalytic degradation and mineralization of doxycycline under UV-C and visible light showed successful application of the method under both light sources. However, reaction rate was higher under UV-C irradiation, which degraded doxycycline almost completely in 5 hours, and 68% mineralization was achieved. Synthesized ZnO nano-particles were successfully applied for photocatalytic degradation of doxycycline in a pharmaceutical wastewater sample. The process was fitted to the pseudo first order kinetic model with rate constants in the range of 6-22(×10 -3 ) mg L -1 min -1 with respect to initial concentration of doxycycline under UV-C irradiation. The Langmuir-Hinshelwood model was also employed for describing the photocatalytic reaction with surface reaction kinetic constant k c and equilibrium adsorption constant K LH values calculated as 0.12 mg L -1 min -1 and 2.2 L mg -1 , respectively. Degradation of doxycycline was followed by UV-visible spectroscopy and a validated stability indicating high-performance liquid chromatography method that was developed using stressed samples of doxycycline and could selectively determine doxycycline in the presence of its degradation products. Mass spectrometry was used for determining final degradation products.

Sexual initiation, contraceptive use, and pregnancy among young adolescents.

PubMed

Finer, Lawrence B; Philbin, Jesse M

2013-05-01

To present new data on sexual initiation, contraceptive use, and pregnancy among US adolescents aged 10 to 19, and to compare the youngest adolescents' behaviors with those of older adolescents. Using nationally representative data from several rounds of the National Survey of Family Growth, we performed event history (ie, survival) analyses to examine timing of sexual initiation and contraceptive use. We calculated adolescent pregnancy rates by single year of age using data from the National Center for Health Statistics, the Guttmacher Institute, and the US Census Bureau. Sexual activity is and has long been rare among those 12 and younger; most is nonconsensual. By contrast, most older teens (aged 17-19) are sexually active. Approximately 30% of those aged 15 to 16 have had sex. Pregnancy rates among the youngest teens are exceedingly low, for example, ∼1 per 10 000 girls aged 12. Contraceptive uptake among girls as young as 15 is similar to that of their older counterparts, whereas girls who start having sex at 14 or younger are less likely to have used a method at first sex and take longer to begin using contraception. Sexual activity and pregnancy are rare among the youngest adolescents, whose behavior represents a different public health concern than the broader issue of pregnancies to older teens. Health professionals can improve outcomes for teenagers by recognizing the higher likelihood of nonconsensual sex among younger teens and by teaching and making contraceptive methods available to teen patients before they become sexually active.

Association Between Direct-to-Consumer Advertising and Testosterone Testing and Initiation in the United States, 2009-2013.

PubMed

Layton, J Bradley; Kim, Yoonsang; Alexander, G Caleb; Emery, Sherry L

2017-03-21

Testosterone initiation increased substantially in the United States from 2000 to 2013, especially among men without clear indications. Direct-to-consumer advertising (DTCA) also increased during this time. To investigate associations between televised DTCA and testosterone testing and initiation in the United States. Ecologic study conducted in designated market areas (DMAs) in the United States. Monthly testosterone advertising ratings were linked to DMA-level testosterone use data from 2009-2013 derived from commercial insurance claims. Associations between DTCA and testosterone testing, initiation, and initiation without recent baseline tests were estimated using Poisson generalized estimating equations. Monthly Nielsen ratings for testosterone DTCA in the 75 largest DMAs. (1) Rates of new serum testosterone testing; (2) rates of testosterone initiation (in-office injection, surgical implant, or pharmacy dispensing) for all testosterone products combined and for specific brands; and (3) rates of testosterone initiation without recent serum testosterone testing. Of 17 228 599 commercially insured men in the 75 DMAs, 1 007 990 (mean age, 49.6 [SD, 11.5] years) had new serum testosterone tests and 283 317 (mean age, 51.8 [SD, 11.3] years) initiated testosterone treatment. Advertising intensity varied by geographic region and time, with the highest intensity seen in the southeastern United States and with months ranging from no ad exposures to a mean of 13.6 exposures per household. Nonbranded advertisements were common prior to 2012, with branded advertisements becoming more common during and after 2012. Each household advertisement exposure was associated with a monthly increase in rates of new testosterone testing (rate ratio [RR], 1.006; 95% CI, 1.004-1.008), initiation (RR, 1.007; 95% CI, 1.004-1.010), and initiation without a recent test (RR, 1.008; 95% CI, 1.002-1.013). Mean absolute rate increases were 0.14 tests (95% CI, 0.09-0.19), 0.05 new initiations (95% CI, 0.03-0.08), and 0.02 initiations without a recent test (95% CI, 0.01-0.03) per 10 000 men for each monthly ad exposure over the entire period. Among US men residing in the 75 designated market areas, regional exposure to televised direct-to-consumer advertising was associated with greater testosterone testing, new initiation, and initiation without recent testing.

Suicide by health professionals: a retrospective mortality study in Australia, 2001-2012.

PubMed

Milner, Allison J; Maheen, Humaira; Bismark, Marie M; Spittal, Matthew J

2016-09-19

To report age-standardised rates and methods of suicide by health professionals, and to compare these with suicide rates for other occupations. Retrospective mortality study. All intentional self-harm cases recorded by the National Coronial Information System during the period 2001-2012 were initially included. Cases were excluded if the person was unemployed at the time of death, if their employment status was unknown or occupational information was missing, or if they were under 20 years of age at the time of death. Suicide rates were calculated using Australian Bureau of Statistics population-level data from the 2006 census. Suicide rates and method of suicide by occupational group. Suicide rates for female health professionals were higher than for women in other occupations (medical practitioners: incidence rate ratio [IRR], 2.52; 95% CI, 1.55-4.09; P < 0.001; nurses and midwives: IRR, 2.65; 95% CI, 2.22-3.15; P < 0.001). Suicide rates for male medical practitioners were not significantly higher than for other occupations, but the suicide rate for male nurses and midwives was significantly higher than for men working outside the health professions (IRR, 1.50; 95% CI 1.12-2.01; P = 0.006). The suicide rate for health professionals with ready access to prescription medications was higher than for those in health professions without such access or in non-health professional occupations. The most frequent method of suicide used by health professionals was self-poisoning. Our results indicate the need for targeted prevention of suicide by health professionals.

A measurement and modeling study of temperature in living and fixed tissue during and after radiofrequency exposure.

PubMed

Bermingham, Jacqueline F; Chen, Yuen Y; McIntosh, Robert L; Wood, Andrew W

2014-04-01

Fluorescent intensity of the dye Rhodamine-B (Rho-B) decreases with increasing temperature. We show that in fresh rat brain tissue samples in a custom-made radiofrequency (RF) tissue exposure device, temperature rise due to RF radiation as measured by absorbed dye correlates well with temperature measured nearby by fiber optic probes. Estimates of rate of initial temperature rise (using both probe measurement and the dye method) accord well with estimates of local specific energy absorption rate (SAR). We also modeled the temperature characteristics of the exposure device using combined electromagnetic and finite-difference thermal modeling. Although there are some differences in the rate of cooling following cessation of RF exposure, there is reasonable agreement between modeling and both probe measurement and dye estimation of temperature. The dye method also permits measurement of regional temperature rise (due to RF). There is no clear evidence of local differential RF absorption, but further refinement of the method may be needed to fully clarify this issue. © 2014 Wiley Periodicals, Inc.

Ultra-High Rate Measurements of Spent Fuel Gamma-Ray Emissions

NASA Astrophysics Data System (ADS)

Rodriguez, Douglas; Vandevender, Brent; Wood, Lynn; Glasgow, Brian; Taubman, Matthew; Wright, Michael; Dion, Michael; Pitts, Karl; Runkle, Robert; Campbell, Luke; Fast, James

2014-03-01

Presently there are over 200,000 irradiated spent nuclear fuel (SNF) assemblies in the world, each containing a concerning amount of weapons-usable material. Both facility operators and safeguards inspectors want to improve composition determination. Current measurements are expensive and difficult so new methods are developed through models. Passive measurements are limited since a few specific decay products and the associated down-scatter overwhelm the gamma rays of interest. Active interrogation methods produce gamma rays beyond 3 MeV, minimizing the impact of the passive emissions that drop off sharply above this energy. New devices like the Ultra-High Rate Germanium (UHRGe) detector are being developed to advance these novel measurement methods. Designed for reasonable resolution at 106 s-1 output rates (compared to ~ 1 - 10 e 3 s-1 standards), SNF samples were directly measured using UHRGe and compared to models. Model verification further enables using Los Alamos National Laboratory SNF assembly models, developed under the Next Generation Safeguards Initiative, to determine emission and signal expectations. Measurement results and future application requirements for UHRGe will be discussed.

Replication RCT of Early Universal Prevention Effects on Young Adult Substance Misuse

PubMed Central

Spoth, Richard; Trudeau, Linda; Redmond, Cleve; Shin, Chungyeol

2014-01-01

Objective For many substances, more frequent and problematic use occurs in young adulthood; these types of use are predicted by the timing of initiation during adolescence. We replicated and extended an earlier study examining whether delayed substance initiation during adolescence, resulting from universal preventive interventions implemented in middle school, reduces problematic use in young adulthood. Method Participants were middle school students from 36 Iowa schools randomly assigned to the Strengthening Families Program plus Life Skills Training (SFP 10–14 + LST), LST-only, or a control condition. Self-report questionnaires were collected at 11 time points, including four during young adulthood. The intercept (average level) and rate of change (slope) in young adult frequency measures (drunkenness, alcohol-related problems, cigarettes, and illicit drugs) across ages 19–22 were modeled as outcomes influenced by growth factors describing substance initiation during adolescence. Analyses entailed testing a two-step hierarchical latent growth curve model; models included the effects of baseline risk, intervention condition assignment, and their interaction. Results Analyses showed significant indirect intervention effects on the average levels of all young adult outcomes, through effects on adolescent substance initiation growth factors, along with intervention by risk interaction effects favoring the higher-risk subsample. Additional direct effects on young adult use were observed in some cases. Relative reduction rates were larger for the higher-risk subsample at age 22, ranging from 5.8% to 36.4% on outcomes showing significant intervention effects. Conclusions Universal preventive interventions implemented during early adolescence have the potential to decrease the rates of substance use and associated problems, into young adulthood. PMID:24821095

Life cycle contributions of copper from vessel painting and maintenance activities

PubMed Central

Earley, Patrick J.; Swope, Brandon L.; Barbeau, Katherine; Bundy, Randelle; McDonald, Janessa A.; Rivera-Duarte, Ignacio

2013-01-01

Copper-based epoxy and ablative antifouling painted panels were exposed in natural seawater to evaluate environmental loading parameters. In situ loading factors including initial exposure, passive leaching, and surface refreshment were measured utilizing two protocols developed by the US Navy: the dome method and the in-water hull cleaning sampling method. Cleaning techniques investigated included a soft-pile carpet and a medium duty 3M™ pad for fouling removal. Results show that the passive leach rates of copper peaked three days after both initial deployment and cleaning events (CEs), followed by a rapid decrease over about 15 days and a slow approach to asymptotic levels on approximately day 30. Additionally, copper was more bioavailable during a CE in comparison to the passive leaching that immediately followed. A paint life cycle model quantifying annual copper loading estimates for each paint and cleaning method based on a three-year cycle of painting, episodic cleaning, and passive leaching is presented. PMID:24199998

Power series solution of the inhomogeneous exclusion process

NASA Astrophysics Data System (ADS)

Szavits-Nossan, Juraj; Romano, M. Carmen; Ciandrini, Luca

2018-05-01

We develop a power series method for the nonequilibrium steady state of the inhomogeneous one-dimensional totally asymmetric simple exclusion process (TASEP) in contact with two particle reservoirs and with site-dependent hopping rates in the bulk. The power series is performed in the entrance or exit rates governing particle exchange with the reservoirs, and the corresponding particle current is computed analytically up to the cubic term in the entry or exit rate, respectively. We also show how to compute higher-order terms using combinatorial objects known as Young tableaux. Our results address the long outstanding problem of finding the exact nonequilibrium steady state of the inhomogeneous TASEP. The findings are particularly relevant to the modeling of mRNA translation in which the rate of translation initiation, corresponding to the entrance rate in the TASEP, is typically small.

Effects of Aggregation on Blood Sedimentation and Conductivity

PubMed Central

Zhbanov, Alexander; Yang, Sung

2015-01-01

The erythrocyte sedimentation rate (ESR) test has been used for over a century. The Westergren method is routinely used in a variety of clinics. However, the mechanism of erythrocyte sedimentation remains unclear, and the 60 min required for the test seems excessive. We investigated the effects of cell aggregation during blood sedimentation and electrical conductivity at different hematocrits. A sample of blood was drop cast into a small chamber with two planar electrodes placed on the bottom. The measured blood conductivity increased slightly during the first minute and decreased thereafter. We explored various methods of enhancing or retarding the erythrocyte aggregation. Using experimental measurements and theoretical calculations, we show that the initial increase in blood conductivity was indeed caused by aggregation, while the subsequent decrease in conductivity resulted from the deposition of erythrocytes. We present a method for calculating blood conductivity based on effective medium theory. Erythrocytes are modeled as conducting spheroids surrounded by a thin insulating membrane. A digital camera was used to investigate the erythrocyte sedimentation behavior and the distribution of the cell volume fraction in a capillary tube. Experimental observations and theoretical estimations of the settling velocity are provided. We experimentally demonstrate that the disaggregated cells settle much slower than the aggregated cells. We show that our method of measuring the electrical conductivity credibly reflected the ESR. The method was very sensitive to the initial stage of aggregation and sedimentation, while the sedimentation curve for the Westergren ESR test has a very mild slope in the initial time. We tested our method for rapid estimation of the Westergren ESR. We show a correlation between our method of measuring changes in blood conductivity and standard Westergren ESR method. In the future, our method could be examined as a potential means of accelerating ESR tests in clinical practice. PMID:26047511

Evaluation of Traditional and Contemporary Methods for Detecting Syphacia obvelata and Aspiculuris tetraptera in Laboratory Mice

PubMed Central

Gerwin, Philip M; Arbona, Rodolfo J Ricart; Riedel, Elyn R; Lepherd, Michelle L; Henderson, Ken S; Lipman, Neil S

2017-01-01

There is no consensus regarding the best practice for detecting murine pinworm infections. Initially, we evaluated 7 fecal concentration methods by using feces containing Aspiculuris tetraptera (AT) eggs (n = 20 samples per method). Sodium nitrate flotation, sodium nitrate centrifugation, Sheather sugar centrifugation, and zinc sulfate centrifugation detected eggs in 100% of samples; zinc sulfate flotation and water sedimentation detected eggs in 90%. All had better detection rates than Sheather sugar flotation (50%). To determine optimal detection methods, Swiss Webster mice were exposed to Syphacia obvelata (SO; n = 60) or AT (n = 60). We compared the following methods at days 0, 30, and 90, beginning 21 or 28 d after SO and AT exposure, respectively: fecal concentration (AT only), anal tape test (SO only), direct examination of intestinal contents (cecum and colon), Swiss roll histology (cecum and colon), and PCR analysis (pooled fur swab and feces). Detection rates for SO-exposed mice were: PCR analysis, 45%; Swiss roll histology, 30%; intestinal content exam, 27%; and tape test, 27%. The SO detection rate for PCR analysis was significantly greater than that for the tape test. Detection rates for AT-exposed mice were: intestinal content exam, 53%; PCR analysis, 33%; fecal flotation, 22%; and Swiss roll histology, 17%. The AT detection rate of PCR analysis combined with intestinal content examination was greater than for PCR analysis only and the AT detection rate of intestinal content examination was greater than for Swiss roll histology. Combining PCR analysis with intestinal content examination detected 100% of infected animals. No single test detected all positive animals. We recommend combining PCR analysis with intestinal content examination for optimal pinworm detection. PMID:28905712

Age at smoking initiation and self-rated health among second grade high school boys and girls in Scania, Sweden, a cross-sectional study.

PubMed

Hansen, Kristina; Lindström, Martin; Rosvall, Maria

2015-11-18

Smoking is usually initiated early in life and most adult regular smokers have started smoking before 18 years of age. A younger age at smoking initiation is associated with risk taking behaviours and worse health outcomes regarding psychological and somatic conditions, suggested to be caused by exposure during critical developmental periods. The present study aims to investigate self-rated health among second grade high school boys and girls related to age at smoking initiation (<14 years of age and ≥ 14 years of age) among current and former smokers, compared to never smokers. Data was derived from the Scania public health survey among children and adolescents in 2012. The study was cross-sectional with retrospective information about first time cigarette smoking experiences among 3245 boys and 3434 girls in second grade of high school. Self-rated health was assessed with the question "How do you rate your general health". Associations of age at smoking initiation, current smoking status and poor self-rated health were investigated with logistic regression models. Crude odds ratios of poor self-rated health were increased for all smoking groups compared to never smokers. Former smoking boys and currently smoking girls with early smoking initiation had the highest odds ratios of poor self-rated health, with odds ratios (OR) 2.4 (95 % confidence interval (CI): 1.5-3.7) and OR 2.9 (95 % CI: 2.3-3.6), respectively. After adjustments for sociodemographic factors, health-related behaviours, psychosocial factors, weight and functional disabilities, the results were attenuated, but remained statistically significant regarding former and current smoking boys with early smoking initiation, OR 2.0 (95 % CI: 1.1-3.7) and OR 1.7 (95 % CI: 1.1-2.4) and for current smoking girls with early and later smoking initiation, OR 2.1 (95 % CI: 1.5-2.8) and OR 1.5 (95 % CI: 1.1-2.0). Boys and girls in second grade of high school with early smoking initiation reported poorer self-rated health than later initiators and never smokers. Poorer self-rated health persisted also after smoking cessation among early initiating boys. Further studies are needed to understand the adverse health effects associated with timing of smoking initiation.

Loss to follow-up among children and adolescents growing up with HIV infection: age really matters

PubMed Central

Kranzer, Katharina; Bradley, John; Musaazi, Joseph; Nyathi, Mary; Gunguwo, Hilary; Ndebele, Wedu; Dixon, Mark; Ndhlovu, Mbongeni; Rehman, Andrea; Khan, Palwasha; Vogt, Florian; Apollo, Tsitsi; Ferrand, Rashida Abbas

2017-01-01

Abstract Introduction: Globally, increasing numbers of HIV-infected children are reaching adolescence due to antiretroviral therapy (ART). We investigated rates of loss-to-follow-up (LTFU) from HIV care services among children as they transition from childhood through adolescence. Methods: Individuals aged 5–19 years initiated on ART in a public-sector HIV clinic in Bulawayo, Zimbabwe, between 2005 and 2009 were included in a retrospective cohort study. Participants were categorized into narrow age-bands namely: 5–9 (children), 10–14 (young adolescents) and 15–19 (older adolescents). The effect of age at ART initiation, current age (using a time-updated Lexis expansion) and transitioning from one age group to the next on LTFU was estimated using Poisson regression. Results: Of 2273 participants, 1013, 875 and 385 initiated ART aged 5–9, 10–14 and 15–19 years, respectively. Unlike those starting ART as children, individuals starting ART as young adolescents had higher LTFU rates after moving to the older adolescent age-band (Adjusted rate ratio (ARR) 1.54; 95% CI: 0.94–2.55) and similarly, older adolescents had higher LTFU rates after transitioning to being young adults (ARR 1.79; 95% CI: 1.05–3.07). In older adolescents, the LTFU rate among those who started ART in that age-band was higher compared to the rate among those starting ART at a younger age (ARR = 1.70; 95% CI: 1.05, 2.77). This however did not hold true for other age-groups. Conclusions: Adolescents had higher rates of LTFU compared to other age-groups, with older adolescents at particularly high risk in all analyses. Age-updated analyses that examine movement across narrow age-bands are paramount in understanding how developmental heterogeneity in children affects HIV outcomes. PMID:28715158

Initial fuel temperature effects on burning rate of pool fire.

PubMed

Chen, Bing; Lu, Shou-Xiang; Li, Chang-Hai; Kang, Quan-Sheng; Lecoustre, Vivien

2011-04-15

The influence of the initial fuel temperature on the burning behavior of n-heptane pool fire was experimentally studied at the State Key Laboratory of Fire Science (SKLFS) large test hall. Circular pool fires with diameters of 100mm, 141 mm, and 200 mm were considered with initial fuel temperatures ranging from 290 K to 363 K. Burning rate and temperature distributions in fuel and vessel wall were recorded during the combustion. The burning rate exhibited five typical stages: initial development, steady burning, transition, bulk boiling burning, and decay. The burning rate during the steady burning stage was observed to be relatively independent of the initial fuel temperature. In contrast, the burning rate of the bulk boiling burning stage increases with increased initial fuel temperature. It was also observed that increased initial fuel temperature decreases the duration of steady burning stage. When the initial temperature approaches the boiling point, the steady burning stage nearly disappears and the burning rate moves directly from the initial development stage to the transition stage. The fuel surface temperature increases to its boiling point at the steady burning stage, shortly after ignition, and the bulk liquid reaches boiling temperature at the bulk boiling burning stage. No distinguished cold zone is formed in the fuel bed. However, boiling zone is observed and the thickness increases to its maximum value when the bulk boiling phenomena occurs. Copyright © 2011 Elsevier B.V. All rights reserved.

[Analysis of diagnosis and treatment of Alport syndrome].

PubMed

An, X G; Zhang, Y Q; Ding, J; Wang, F; Xiao, H J; Yao, Y

2016-09-01

To investigate the clinical characteristics and the status of diagnosis and treatment of patients with Alport syndrome in China. Patients with affirmative diagnosis of Alport syndrome from Department of Pedatrics, Peking University First Hospital in the past 20 years (1995-2015) were analyzed retrospectively. The clinical data including initial symptoms, visit reasons, age at onset of disease, family history, hereditary mode, methods of diagnosis, misdiagnosis and mistreatment were collected. A total of 398 patients with Alport syndrome were included in this study, 48.2% of patients had the onset of symptoms before age of 3 years. The rate of onset of symptoms and diagnosis before age of 17 years were 95.7%. The initial symptoms included gross hematuria (37.2%), microscopic hematuria and proteinuria (25.1%), microscopic hematuria (14.8%), edema of eyelid and lower limbs (10.3%), increased foam in urine (4.3%), etc.; 39.5% of patients had no symptoms of urinary tract. Only 14.0% of the patients were diagnosed as Alport syndrome for the first time, and 86.0% of the patients were misdiagnosed. Hormones and immunosuppressive agents were used in 19.0% of patients diagnosed as Alport syndrome, and in 43.0% of patients there was misdiagnosis. Skin biopsy and immunofluorescence of type Ⅳ collagen ɑ5 chain in epithelial basement membrane had a detection rate of 77.8%. Electron microscopy of glomerular basement membrane had a detection rate of 92.6%, and genetic testing 96.6%. The time interval of diagnosis was 18.2 months and was gradually shortened in recent years. Alport syndrome developed at a very young age. Hematuria was the most frequent initial symptom. There was a high rate of misdiagnosis and mistreatment for Alport syndrome. Genetic testing for Alport syndrome had advantages of high detection rate, genetic consultation and prenatal diagnosis.

Dental Homes for Children With Autism

PubMed Central

Chi, Donald L.; Momany, Elizabeth T.; Mancl, Lloyd A.; Lindgren, Scott D.; Zinner, Samuel H.; Steinman, Kyle J.

2015-01-01

Introduction Medicaid-enrolled children with autism spectrum disorder (ASD) encounter significant barriers to dental care. Iowa’s I-Smile Program was implemented in 2006 to improve dental use for all children in Medicaid. This study compared dental home and preventive dental utilization rates for Medicaid-enrolled children by ASD status and within three time periods (pre-implementation, initial implementation, maturation) and determined I-Smile’s longitudinal influence on ASD-related dental use disparities. Methods Data from 2002–2011 were analyzed for newly Medicaid-enrolled children aged 3–17 years (N=30,059), identified each child’s ASD status, and assessed whether the child had a dental home or utilized preventive dental care. Log-linear regression models were used to generate rate ratios. Analyses were conducted in 2015. Results In 2003–2011, 9.8% of children with ASD had dental homes compared with 8% of children without ASD; 36.3% of children with ASD utilized preventive care compared to 45.7% of children without ASD. There were no significant differences in dental home rates by ASD status during pre-implementation, initial implementation, or maturation. There were no significant differences in preventive dental utilization by ASD status during pre-implementation or initial implementation, but children with ASD were significantly less likely to utilize preventive care during maturation (rate ratio=0.79, p<0.001). Longitudinal trends in dental home and preventive dental utilization rates were not significant (p=0.54 and p=0.71, respectively). Conclusions Among newly Medicaid-enrolled children in Iowa’s I-Smile Program, those with ASDs were not less likely than those without ASD to have dental homes but were significantly less likely to utilize preventive dental care. PMID:26514624

Radiologic Placement of Uncovered Stents for the Treatment of Malignant Colonic Obstruction Proximal to the Descending Colon

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

Yoon, Jehong; Kwon, Se Hwan, E-mail: Kwon98@khu.ac.kr; Lee, Chang-Kyun

PurposeTo evaluate the safety, feasibility, and patency rates of radiologic placement of uncovered stents for the treatment of malignant colonic obstruction proximal to the descending colon.Materials and MethodsThis was a retrospective, single-center study. From May 2003 to March 2015, 53 image-guided placements of uncovered stents (44 initial placements, 9 secondary placements) were attempted in 44 patients (male:female = 23:21; mean age, 71.8 years). The technical and clinical success, complication rates, and patency rates of the stents were also evaluated. Technical success was defined as the successful deployment of the stent under fluoroscopic guidance alone and clinical success was defined as the relief of obstructivemore » symptoms or signs within 48 h of stent deployment.ResultsIn total, 12 (27.3 %) patients underwent preoperative decompression, while 32 (72.7 %) underwent decompression with palliative intent. The technical success rate was 93.2 % (41/44) for initial placement and 88.9 % (8/9) for secondary placement. Secondary stent placement in the palliative group was required in nine patients after successful initial stent placement due to stent obstruction from tumor ingrowth (n = 7) and stent migration (n = 2). The symptoms of obstruction were relieved in all successful cases (100 %). In the palliative group, the patency rates were 94.4 % at 1 month, 84.0 % at 3 months, 64.8 % at 6 months, and 48.6 % at 12 months.ConclusionsThe radiologic placement of uncovered stents for the treatment of malignant obstruction proximal to the descending colon is feasible and safe, and provides acceptable clinical results.« less

Recruiting Ethnically Diverse General Internal Medicine Patients for a Telephone Survey on Physician-Patient Communication

PubMed Central

Nápoles-Springer, Anna M; Santoyo, Jasmine; Stewart, Anita L

2005-01-01

BACKGROUND Limited evidence exists on the effectiveness of recruitment methods among diverse populations. OBKECTIVE Describe response rates by recruitment stage, ethnic-language group, and type of initial contact letter (for African-American and Latino patients). DESIGN Tracking of response status by recruitment stage and ethnic-language group and a randomized trial of ethnically tailored initial letters nested within a cross-sectional telephone survey on physician-patient communication. PARTICIPANTS Adult general medicine patients with ≥1 visit during the preceding year, stratified by 4 categories: African-American (N= 1,400), English-speaking Latino (N= 894), Spanish-speaking Latino (N= 965), and non-Latino white (N= 1,400). MEASUREMENTS AND RESULTS Ethnically tailored initial letters referred to shortages of African-American (or Latino) physicians and the need to learn about the experiences of African-American (or Latino) patients communicating with physicians. Of 2,482 patients contacted, eligible, and able to participate (identified eligibles), 69.9% completed the survey. Thirty-nine percent of the sampling frame was unable to be contacted, with losses higher among non-Latino whites (46.5%) and African Americans (44.2%) than among English-speaking (32.3%) and Spanish-speaking Latinos (25.1%). For identified eligibles, response rates were highest among Spanish-speaking Latinos (75.2%), lowest for non-Latino whites (66.4%), and intermediate for African Americans (69.7%) and English-speaking Latinos (68.1%). There were no differences in overall response rates between patients receiving ethnically tailored letters (72.2%) and those receiving general letters (70.0%). CONCLUSIONS Household contact and individual response rates differed by ethnic-language group, highlighting the importance of tracking losses by stage and subpopulation. Careful attention to recruitment yielded acceptable response rates among all groups. PMID:15963168

Modified Cisplatin/Interferon α-2b/Doxorubicin/Fluorouracil (PIAF) chemotherapy in patients with no hepatitis or cirrhosis is associated with improved response rate, resectability and survival of initially unresectable hepatocellular carcinoma

PubMed Central

Kaseb, Ahmed O.; Shindoh, Junichi; Patt, Yehuda Z.; Roses, Robert E.; Zimmitti, Giuseppe; Lozano, Richard D.; Hassan, Manal M.; Hassabo, Hesham M.; Curley, Steven A.; Aloia, Thomas A.; Abbruzzese, James L.; Vauthey, Jean-Nicolas

2013-01-01

Purpose The purposes of this study was to evaluate the factors associated with response rate, resectability, and survival after cisplatin/interferon α-2b/doxorubicin/5-flurouracil (PIAF) combination therapy in patients with initially unresectable hepatocellular carcinoma (HCC). Patients and Methods The study included two groups of patients treated with conventional high-dose PIAF (n=84) between 1994 and 2003 and those without hepatitis or cirrhosis treated with modified PIAF (n=33) between 2003 and 2012. Tolerance of chemotherapy, best radiographic response, rate of conversion to curative surgery, and overall survival were analyzed and compared between the two groups, and multivariate and logistic regression analyses were applied to identify predictors of response and survival. Results The modified PIAF group had a higher median number of PIAF cycles (4 vs. 2, P = .049), higher objective response rate (36% vs. 15%, P = .013), higher rate of conversion to curative surgery (33% vs. 10%, P = .004), and longer median overall survival (21.3 vs. 10.6 months, P = .002). Multivariate analyses confirmed that positive hepatitis B serology (hazard ratio [HR], 1.68; 95% CI, 1.08 to 2.59) and Eastern Cooperative Oncology Group performance status ≥2 (HR, 1.75; 95% CI 1.04 to 2.93) were associated with worse survival while curative surgical resection after PIAF treatment (HR, 0.15; 95% CI, 0.07 to 0.35) was associated with improved survival. Conclusions In patients with initially unresectable HCC, the modified PIAF regimen in patients with no hepatitis or cirrhosis is associated with improved response, resectability, and survival. PMID:23821538

An EGR performance evaluation and decision-making approach based on grey theory and grey entropy analysis

PubMed Central

2018-01-01

Exhaust gas recirculation (EGR) is one of the main methods of reducing NOX emissions and has been widely used in marine diesel engines. This paper proposes an optimized comprehensive assessment method based on multi-objective grey situation decision theory, grey relation theory and grey entropy analysis to evaluate the performance and optimize rate determination of EGR, which currently lack clear theoretical guidance. First, multi-objective grey situation decision theory is used to establish the initial decision-making model according to the main EGR parameters. The optimal compromise between diesel engine combustion and emission performance is transformed into a decision-making target weight problem. After establishing the initial model and considering the characteristics of EGR under different conditions, an optimized target weight algorithm based on grey relation theory and grey entropy analysis is applied to generate the comprehensive evaluation and decision-making model. Finally, the proposed method is successfully applied to a TBD234V12 turbocharged diesel engine, and the results clearly illustrate the feasibility of the proposed method for providing theoretical support and a reference for further EGR optimization. PMID:29377956

An EGR performance evaluation and decision-making approach based on grey theory and grey entropy analysis.

PubMed

Zu, Xianghuan; Yang, Chuanlei; Wang, Hechun; Wang, Yinyan

2018-01-01

Exhaust gas recirculation (EGR) is one of the main methods of reducing NOX emissions and has been widely used in marine diesel engines. This paper proposes an optimized comprehensive assessment method based on multi-objective grey situation decision theory, grey relation theory and grey entropy analysis to evaluate the performance and optimize rate determination of EGR, which currently lack clear theoretical guidance. First, multi-objective grey situation decision theory is used to establish the initial decision-making model according to the main EGR parameters. The optimal compromise between diesel engine combustion and emission performance is transformed into a decision-making target weight problem. After establishing the initial model and considering the characteristics of EGR under different conditions, an optimized target weight algorithm based on grey relation theory and grey entropy analysis is applied to generate the comprehensive evaluation and decision-making model. Finally, the proposed method is successfully applied to a TBD234V12 turbocharged diesel engine, and the results clearly illustrate the feasibility of the proposed method for providing theoretical support and a reference for further EGR optimization.

Magnetometer-only attitude and rate determination for a gyro-less spacecraft

NASA Technical Reports Server (NTRS)

Natanson, G. A.; Challa, M. S.; Deutschmann, J.; Baker, D. F.

1994-01-01

Attitude determination algorithms that requires only the earth's magnetic field will be useful for contingency conditions. One way to determine attitude is to use the time derivative of the magnetic field as the second vector in the attitude determination process. When no gyros are available, however, attitude determination becomes difficult because the rates must be propagated via integration of Euler's equation, which in turn requires knowledge of the initial rates. The spacecraft state to be determined must then include not only the attitude but also rates. This paper describes a magnetometer-only attitude determination scheme with no a priori knowledge of the spacecraft state, which uses a deterministic algorithm to initialize an extended Kalman filter. The deterministic algorithm uses Euler's equation to relate the time derivatives of the magnetic field in the reference and body frames and solves the resultant transcendental equations for the coarse attitude and rates. An important feature of the filter is that its state vector also includes corrections to the propagated rates, thus enabling it to generate highly accurate solutions. The method was tested using in-flight data from the Solar, Anomalous, and Magnetospheric Particles Explorer (SAMPEX), a Small Explorer spacecraft. SAMPEX data using several eclipse periods were used to simulate conditions that may exist during the failure of the on-board digital sun sensor. The combined algorithm has been found effective, yielding accuracies of 1.5 deg in attitude (within even nominal mission requirements) and 0.01 degree per second (deg/sec) in the rates.

Increasing low birth weight rates: deliveries in a tertiary hospital in istanbul.

PubMed

Akin, Yasemin; Cömert, Serdar; Turan, Cem; Unal, Orhan; Piçak, Abdülkadir; Ger, Lale; Telatar, Berrin

2010-09-01

Prevalence of low birth weight deliveries may vary across different environments. The necessity of determination of regional data prompted this study. Information of all deliveries from January 2004 to December 2008 was obtained from delivery registry records retrospectively. Initial data including birth weight, vital status, sex, maternal age and mode of delivery were recorded using medical files. The frequency of low birth weight, very low birth weight, extremely low birth weight and stillbirth deliveries were determined. Among 19,533 total births, there were 450 (23.04 per 1000) stillbirths. Low birth weight rate was 10.61%. A significant increase in yearly distribution of low birth weight deliveries was observed (P<0.001). Very low birth weight and extremely low birth weight delivery rates were 3.14% and 1.58% respectively. Among 2073 low birth weight infants, 333 (16.06%) were stillbirths. The stillbirth delivery rate and the birth of a female infant among low birth weight deliveries were significantly higher than infants with birth weight ≥2500g (P<0.001, OR=28.37), (P<0.001) retrospectively. There was no statistical difference between low birth weight and maternal age. The rate of cesarean section among low birth weight infants was 49.4%. High low birth weight and stillbirth rates, as well as the increase in low birth weight deliveries over the past five years in this study are striking. For reduction of increased low birth weight rates, appropriate intervention methods should be initiated.

Further study on the wheel-rail impact response induced by a single wheel flat: the coupling effect of strain rate and thermal stress

NASA Astrophysics Data System (ADS)

Jing, Lin; Han, Liangliang

2017-12-01

A comprehensive dynamic finite-element simulation method was proposed to study the wheel-rail impact response induced by a single wheel flat based on a 3-D rolling contact model, where the influences of the structural inertia, strain rate effect of wheel-rail materials and thermal stress due to the wheel-rail sliding friction were considered. Four different initial conditions (i.e. pure mechanical loading plus rate-independent, pure mechanical loading plus rate-dependent, thermo-mechanical loading plus rate-independent, and thermo-mechanical loading plus rate-dependent) were involved into explore the corresponding impact responses in term of the vertical impact force, von-Mises equivalent stress, equivalent plastic strain and shear stress. Influences of train speed, flat length and axle load on the flat-induced wheel-rail impact response were discussed, respectively. The results indicate that the maximum thermal stresses are occurred on the tread of the wheel and on the top surface of the middle rail; the strain rate hardening effect contributes to elevate the von-Mises equivalent stress and restrain the plastic deformation; and the initial thermal stress due to the sliding friction will aggravate the plastic deformation of wheel and rail. Besides, the wheel-rail impact responses (i.e. impact force, von-Mises equivalent stress, equivalent plastic strain, and XY shear stress) induced by a flat are sensitive to the train speed, flat length and axle load.

Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities.

PubMed

Chen, Xuanzhen; Peng, Yong; Peng, Shan; Yao, Song; Chen, Chao; Xu, Ping

2017-01-01

This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture.

Geography of primary mental health care through the Better Access initiative in South Australia 2006-2010.

PubMed

Carson, Dean; Bidargaddi, Niranjan; Schrader, Geoffrey; Allison, Stephen; Jones, Gabrielle Margaret; Bastiampillai, Tarun; Strobel, Jörg

2016-06-01

To examine how the rates of the use of particular face-to-face primary mental health care services changed in the first 4 years (2006-2010) of the Better Access initiative in both urban and rural regions of South Australia. Time-series analysis of the number of psychology session, psychiatry assessment and general practitioner care plan services recorded in Medicare Australia data. South Australia. Pre-existing data set of South Australian residents who accessed Medicare between 2006 and 2010 MAIN OBJECTIVE MEASURE: Number of services per 100 000 population (service rate). Psychology session service rates increased in all regions, but continued to follow a 'location gradient', being higher in areas closer to Adelaide and lower in areas more distant from Adelaide. Psychiatry assessment service rates increased in Adelaide but did not change in other regions. Rates in remote areas were subject to substantial variation over time. General practitioner care plan service rates increased in Adelaide and in the Riverland, but declined in the Murray Mallee region. Overall, service rates increased in Adelaide and nearby regions, but the results for rural and remote regions were mixed. Possible explanations for the geographical variability include population characteristics (such as socio-economic status), methods of service delivery (visiting practitioners, telepsych), the relative proportion of total health services provided by general practitioners versus other practitioners, or real variations in the need for primary mental health services. © 2015 National Rural Health Alliance Inc.

Circulatory Responses to Asphyxia Differ if the Asphyxia Occurs In Utero or Ex Utero in Near-Term Lambs

PubMed Central

Sobotka, Kristina S.; Morley, Colin; Ong, Tracey; Polglase, Graeme R.; Aridas, James D. S.; Miller, Suzanne L.; Schmölzer, Georg M.; Klingenberg, Claus; Moss, Timothy J. M.; Jenkin, Graham; Hooper, Stuart B.

2014-01-01

Background A cornerstone of neonatal resuscitation teaching suggests that a rapid vagal-mediated bradycardia is one of the first signs of perinatal compromise. As this understanding is based primarily on fetal studies, we investigated whether the heart rate and blood pressure response to total asphyxia is influenced by whether the animal is in utero or ex utero. Methods Fetal sheep were instrumented at ∼139 days of gestation and then asphyxiated by umbilical cord occlusion until mean arterial blood pressure decreased to ∼20 mmHg. Lambs were either completely submerged in amniotic fluid (in utero; n = 8) throughout the asphyxia or were delivered and then remained ex utero (ex utero; n = 8) throughout the asphyxia. Heart rate and arterial blood pressure were continuously recorded. Results Heart rate was higher in ex utero lambs than in utero lambs. Heart rates in in utero lambs rapidly decreased, while heart rates in ex utero lambs initially increased following cord occlusion (for ∼1.5 min) before they started to decrease. Mean arterial pressure initially increased then decreased in both groups. Conclusions Heart rate response to asphyxia was markedly different depending upon whether the lamb was in utero or ex utero. This indicates that the cardiovascular responses to perinatal asphyxia are significantly influenced by the newborn's local environment. As such, based solely on heart rate, the stage and severity of a perinatal asphyxic event may not be as accurate as previously assumed. PMID:25393411

Changes in healthcare-associated Staphylococcus aureus bloodstream infections after the introduction of a national hand hygiene initiative.

PubMed

Barnett, Adrian G; Page, Katie; Campbell, Megan; Brain, David; Martin, Elizabeth; Rashleigh-Rolls, Rebecca; Halton, Kate; Hall, Lisa; Jimmieson, Nerina; White, Katherine; Paterson, David; Graves, Nicholas

2014-08-01

Interventions that prevent healthcare-associated infection should lead to fewer deaths and shorter hospital stays. Cleaning hands (with soap or alcohol) is an effective way to prevent the transmission of organisms, but rates of compliance with hand hygiene are sometimes disappointingly low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infection. We examined whether the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for healthcare-associated Staphylococcus aureus bloodstream infections were examined in 38 Australian hospitals across 6 states. We used Poisson regression and examined 12 possible patterns of change, with the best fitting pattern chosen using the Akaike information criterion. Monthly bed-days were included to control for increased hospital use over time. The National Hand Hygiene Initiative was associated with a reduction in infection rates in 4 of the 6 states studied. Two states showed an immediate reduction in rates of 17% and 28%, 2 states showed a linear decrease in rates of 8% and 11% per year, and 2 showed no change in infection rates. The intervention was associated with reduced infection rates in most states. The failure in 2 states may have been because those states already had effective initiatives before the national initiative's introduction or because infection rates were already low and could not be further reduced.

The impact of new insights and revised practice guidelines on prescribing drugs in the treatment of Type 2 diabetes mellitus

PubMed Central

Lub, René; Denig, Petra; van den Berg, Paul B; Hoogenberg, Klaas; de Jong-van den Berg, Lolkje T W

2006-01-01

Aims The aim of this study was to investigate the impact of new insights and revised guidelines on initial and follow-up treatment with antihyperglycaemic drugs over the period 1998–2003. Methods The InterAction Database (IADB), which contains pharmacy dispensing data from 53 community pharmacies in the Northern and Eastern part of the Netherlands, was used in this study. Prevalence and incidence rates of oral antihyperglycaemic drug use were calculated for each year. Follow-up treatment was compared for two cohorts of initial users of oral antihyperglycaemic drugs, starting treatment either 1 year before or 1 year after guideline revision. Results The prevalence and incidence rate of oral antihyperglycaemic drug use increased over the study period from 1.8% to 2.4% (P < 0.001) and 0.3% to 0.4% (P= 0.04). The proportion of metformin as initial treatment increased rapidly in the observation period from 14% to 50% (P < 0.001). Initial users of metformin in 2000 received additional treatment with a sulphonylurea in the follow-up period less often compared with those who started metformin in 1998 (46%vs. 60%, P < 0.004). In contrast, initial users of sulphonylurea in 2000 received additional treatment with metformin more often compared with those who started a sulphonylurea in 1998 (42%vs. 36%, P < 0.008). The new drugs, thiazolidinediones and meglitinides, were seldom used as initial treatment Conclusions New insights and the revision of the practice guideline were followed by a significant increase in both initial and follow-up treatment with metformin among patients with Type 2 diabetes mellitus. PMID:16796700

ISS Contingency Attitude Control Recovery Method for Loss of Automatic Thruster Control

NASA Technical Reports Server (NTRS)

Bedrossian, Nazareth; Bhatt, Sagar; Alaniz, Abran; McCants, Edward; Nguyen, Louis; Chamitoff, Greg

2008-01-01

In this paper, the attitude control issues associated with International Space Station (ISS) loss of automatic thruster control capability are discussed and methods for attitude control recovery are presented. This scenario was experienced recently during Shuttle mission STS-117 and ISS Stage 13A in June 2007 when the Russian GN&C computers, which command the ISS thrusters, failed. Without automatic propulsive attitude control, the ISS would not be able to regain attitude control after the Orbiter undocked. The core issues associated with recovering long-term attitude control using CMGs are described as well as the systems engineering analysis to identify recovery options. It is shown that the recovery method can be separated into a procedure for rate damping to a safe harbor gravity gradient stable orientation and a capability to maneuver the vehicle to the necessary initial conditions for long term attitude hold. A manual control option using Soyuz and Progress vehicle thrusters is investigated for rate damping and maneuvers. The issues with implementing such an option are presented and the key issue of closed-loop stability is addressed. A new non-propulsive alternative to thruster control, Zero Propellant Maneuver (ZPM) attitude control method is introduced and its rate damping and maneuver performance evaluated. It is shown that ZPM can meet the tight attitude and rate error tolerances needed for long term attitude control. A combination of manual thruster rate damping to a safe harbor attitude followed by a ZPM to Stage long term attitude control orientation was selected by the Anomaly Resolution Team as the alternate attitude control method for such a contingency.

Assessing the Efficacy of Restricting Access to Barbecue Charcoal for Suicide Prevention in Taiwan: A Community-Based Intervention Trial

PubMed Central

Chen, Ying-Yeh; Chen, Feng; Chang, Shu-Sen; Wong, Jacky; Yip, Paul S F

2015-01-01

Objective Charcoal-burning suicide has recently been spreading to many Asian countries. There have also been several cases involving this new method of suicide in Western countries. Restricting access to suicide means is one of the few suicide-prevention measures that have been supported by empirical evidence. The current study aims to assess the effectiveness of a community intervention program that restricts access to charcoal to prevent suicide in Taiwan. Methods and Findings A quasi-experimental design is used to compare method-specific (charcoal-burning suicide, non-charcoal-burning suicide) and overall suicide rates in New Taipei City (the intervention site, with a population of 3.9 million) with two other cities (Taipei City and Kaohsiung City, the control sites, each with 2.7 million residents) before (Jan 1st 2009- April 30th 2012) and after (May 1st 2012-Dec. 31st 2013) the initiation of a charcoal-restriction program on May 1st 2012. The program mandates the removal of barbecue charcoal from open shelves to locked storage in major retail stores in New Taipei City. No such restriction measure was implemented in the two control sites. Generalized linear regression models incorporating secular trends were used to compare the changes in method-specific and overall suicide rates before and after the initiation of the restriction measure. A simulation approach was used to estimate the number of lives saved by the intervention. Compared with the pre-intervention period, the estimated rate reduction of charcoal-burning suicide in New Taipei City was 37% (95% CI: 17%, 50%) after the intervention. Taking secular trends into account, the reduction was 30% (95% CI: 14%, 44%). No compensatory rise in non-charcoal-burning suicide was observed in New Taipei City. No significant reduction in charcoal-burning suicide was observed in the other two control sites. The simulation approach estimated that 91 (95%CI [55, 128]) lives in New Taipei City were saved during the 20 months of the intervention. Conclusion Our results demonstrate that the charcoal-restriction program reduced method-specific and overall suicides. This study provides strong empirical evidence that restricting the accessibility of common lethal methods of suicide can effectively reduce suicide rates. PMID:26305374

Thermal casting process for the preparation of anisotropic membranes and the resultant membrane

DOEpatents

Caneba, Gerard T. M.; Soong, David S.

1987-01-01

A method for providing anisotropic polymer membranes from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

Thermal casting process for the preparation of membranes

DOEpatents

Caneba, G.T.M.; Soong, D.S.

1985-07-10

Disclosed is a method for providing anisotropic polymer membrane from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

A physician-led initiative to improve clinical documentation results in improved health care documentation, case mix index, and increased contribution margin.

PubMed

Aiello, Francesco A; Judelson, Dejah R; Durgin, Jonathan M; Doucet, Danielle R; Simons, Jessica P; Durocher, Dawn M; Flahive, Julie M; Schanzer, Andres

2018-05-04

Clinical documentation is the key determinant of inpatient acuity of illness and payer reimbursement. Every inpatient hospitalization is placed into a diagnosis related group with a relative value based on documented procedures, conditions, comorbidities and complications. The Case Mix Index (CMI) is an average of these diagnosis related groups and directly impacts physician profiling, medical center profiling, reimbursement, and quality reporting. We hypothesize that a focused, physician-led initiative to improve clinical documentation of vascular surgery inpatients results in increased CMI and contribution margin. A physician-led coding initiative to educate physicians on the documentation of comorbidities and conditions was initiated with concurrent chart review sessions with coding specialists for 3 months, and then as needed, after the creation of a vascular surgery documentation guide. Clinical documentation and billing for all carotid endarterectomy (CEA) and open infrainguinal procedures (OIPs) performed between January 2013 and July 2016 were stratified into precoding and postcoding initiative groups. Age, duration of stay, direct costs, actual reimbursements, contribution margin (CM), CMI, rate of complication or comorbidity, major complication or comorbidity, severity of illness, and risk of mortality assigned to each discharge were abstracted. Data were compared over time by standardizing Centers for Medicare and Medicaid Services (CMS) values for each diagnosis related group and using a CMS base rate reimbursement. Among 458 CEA admissions, postcoding initiative CEA patients (n = 253) had a significantly higher CMI (1.36 vs 1.25; P = .03), CM ($7859 vs $6650; P = .048), and CMS base rate reimbursement ($8955 vs $8258; P = .03) than precoding initiative CEA patients (n = 205). The proportion of admissions with a documented major complication or comorbidity and complication or comorbidity was significantly higher after the coding initiative (43% vs 27%; P < .01). Among 504 OIPs, postcoding initiative patients (n = 227) had a significantly higher CMI (2.23 vs 2.05; P < .01), actual reimbursement ($23,203 vs $19,909; P < .01), CM ($12,165 vs $8840; P < .01), and CMS base rate reimbursement ($14,649 vs $13,496; P < .01) than precoding initiative patients (n = 277). The proportion of admissions with a documented major complication or comorbidity and complication or comorbidity was significantly higher after the coding initiative (61% vs 43%; P < .01). For both CEA and OIPs, there were no differences in age, duration of stay, total direct costs, or primary insurance status between the precoding and postcoding patient groups. Accurate and detailed clinical documentation is required for key stakeholders to characterize the acuity of inpatient admissions and ensure appropriate reimbursement; it is also a key component of risk-adjustment methods for assessing quality of care. A physician-led documentation initiative significantly increased CMI and CM. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

A Contribution to the Problem of Initiation of a Combustion Source in an Oil-Saturated Bed

NASA Astrophysics Data System (ADS)

Koznacheev, I. A.; Dobrego, K. V.

2013-11-01

The problem on in-situ self-ignition of an oil-saturated bed under the conditions of forced filtration of an oxygen-containing gas has been solved with analytical and numerical methods with account of the burnout of a deficient gas component. The influence of the burnout of this component and of convective removal of heat from the bed on the time of its self-ignition has been determined. Recommendations for the optimum regime of initiation of the self-ignition of the bed with account of variation of the blast flow rate and the oxygen content have been given.

Medication safety initiative in reducing medication errors.

PubMed

Nguyen, Elisa E; Connolly, Phyllis M; Wong, Vivian

2010-01-01

The purpose of the study was to evaluate whether a Medication Pass Time Out initiative was effective and sustainable in reducing medication administration errors. A retrospective descriptive method was used for this research, where a structured Medication Pass Time Out program was implemented following staff and physician education. As a result, the rate of interruptions during the medication administration process decreased from 81% to 0. From the observations at baseline, 6 months, and 1 year after implementation, the percent of doses of medication administered without interruption improved from 81% to 99%. Medication doses administered without errors at baseline, 6 months, and 1 year improved from 98% to 100%.

18 CFR 154.202 - Filings to initiate a new rate schedule.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Filings to initiate a new rate schedule. 154.202 Section 154.202 Conservation of Power and Water Resources FEDERAL ENERGY... Procedures for Changing Tariffs § 154.202 Filings to initiate a new rate schedule. (a) When the filing is to...

18 CFR 154.202 - Filings to initiate a new rate schedule.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Filings to initiate a new rate schedule. 154.202 Section 154.202 Conservation of Power and Water Resources FEDERAL ENERGY... Procedures for Changing Tariffs § 154.202 Filings to initiate a new rate schedule. (a) When the filing is to...

18 CFR 154.202 - Filings to initiate a new rate schedule.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Filings to initiate a new rate schedule. 154.202 Section 154.202 Conservation of Power and Water Resources FEDERAL ENERGY... Procedures for Changing Tariffs § 154.202 Filings to initiate a new rate schedule. (a) When the filing is to...

18 CFR 154.202 - Filings to initiate a new rate schedule.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Filings to initiate a new rate schedule. 154.202 Section 154.202 Conservation of Power and Water Resources FEDERAL ENERGY... Procedures for Changing Tariffs § 154.202 Filings to initiate a new rate schedule. (a) When the filing is to...

18 CFR 154.202 - Filings to initiate a new rate schedule.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Filings to initiate a new rate schedule. 154.202 Section 154.202 Conservation of Power and Water Resources FEDERAL ENERGY... Procedures for Changing Tariffs § 154.202 Filings to initiate a new rate schedule. (a) When the filing is to...

38 CFR 4.88c - Ratings for inactive nonpulmonary tuberculosis initially entitled after August 19, 1968.

Code of Federal Regulations, 2010 CFR

2010-07-01

... nonpulmonary tuberculosis initially entitled after August 19, 1968. 4.88c Section 4.88c Pensions, Bonuses, and... tuberculosis initially entitled after August 19, 1968. Rating For 1 year after date of inactivity, following active tuberculosis 100 Thereafter: Rate residuals under the specific body system or systems affected...

38 CFR 4.88c - Ratings for inactive nonpulmonary tuberculosis initially entitled after August 19, 1968.

Code of Federal Regulations, 2013 CFR

2013-07-01

... nonpulmonary tuberculosis initially entitled after August 19, 1968. 4.88c Section 4.88c Pensions, Bonuses, and... tuberculosis initially entitled after August 19, 1968. Rating For 1 year after date of inactivity, following active tuberculosis 100 Thereafter: Rate residuals under the specific body system or systems affected...

38 CFR 4.88c - Ratings for inactive nonpulmonary tuberculosis initially entitled after August 19, 1968.

Code of Federal Regulations, 2011 CFR

2011-07-01

... nonpulmonary tuberculosis initially entitled after August 19, 1968. 4.88c Section 4.88c Pensions, Bonuses, and... tuberculosis initially entitled after August 19, 1968. Rating For 1 year after date of inactivity, following active tuberculosis 100 Thereafter: Rate residuals under the specific body system or systems affected...

38 CFR 4.88c - Ratings for inactive nonpulmonary tuberculosis initially entitled after August 19, 1968.

Code of Federal Regulations, 2014 CFR

2014-07-01

... nonpulmonary tuberculosis initially entitled after August 19, 1968. 4.88c Section 4.88c Pensions, Bonuses, and... tuberculosis initially entitled after August 19, 1968. Rating For 1 year after date of inactivity, following active tuberculosis 100 Thereafter: Rate residuals under the specific body system or systems affected...

38 CFR 4.88c - Ratings for inactive nonpulmonary tuberculosis initially entitled after August 19, 1968.

Code of Federal Regulations, 2012 CFR

2012-07-01

... nonpulmonary tuberculosis initially entitled after August 19, 1968. 4.88c Section 4.88c Pensions, Bonuses, and... tuberculosis initially entitled after August 19, 1968. Rating For 1 year after date of inactivity, following active tuberculosis 100 Thereafter: Rate residuals under the specific body system or systems affected...

47 CFR 76.930 - Initiation of review of basic cable service and equipment rates.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Initiation of review of basic cable service and...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Rate Regulation § 76.930 Initiation of review of basic cable service and equipment rates. A cable operator shall file its schedule of...

Condensation and dissociation rates for gas phase metal clusters from molecular dynamics trajectory calculations

DOE PAGES

Yang, Huan; Goudeli, Eirini; Hogan, Christopher J.

2018-04-24

In gas phase synthesis systems, clusters form and grow via condensation, in which a monomer binds to an existing cluster. While a hard sphere equation is frequently used to predict the condensation rate coefficient, this equation neglects the influences of potential interactions and cluster internal energy on the condensation process. Here, we present a collision rate theory-Molecular Dynamics simulation approach to calculate condensation probabilities and condensation rate coefficients; we use this approach to examine atomic condensation onto 6-56 atom Au and Mg clusters. The probability of condensation depends upon the initial relative velocity ( v) between atom and cluster andmore » the initial impact parameter ( b). In all cases there is a well-defined region of b-v space where condensation is highly probable, and outside of which the condensation probability drops to zero. For Au clusters with more than 10 atoms, we find that at gas temperatures in the 300-1200 K range, the condensation rate coefficient exceeds the hard sphere rate coefficient by a factor of 1.5-2.0. Conversely, for Au clusters with 10 or fewer atoms, and for 14 atom and 28 atom Mg clusters, as cluster equilibration temperature increases the condensation rate coefficient drops to values below the hard sphere rate coefficient. Calculations also yield the self-dissociation rate coefficient, which is found to vary considerably with gas temperature. Finally, calculations results reveal that grazing (high b) atom-cluster collisions at elevated velocity (> 1000 m s -1) can result in the colliding atom rebounding (bounce) from the cluster surface or binding while another atom dissociates (replacement). In conclusion, the presented method can be applied in developing rate equations to predict material formation and growth rates in vapor phase systems.« less

Condensation and dissociation rates for gas phase metal clusters from molecular dynamics trajectory calculations.

PubMed

Yang, Huan; Goudeli, Eirini; Hogan, Christopher J

2018-04-28

In gas phase synthesis systems, clusters form and grow via condensation, in which a monomer binds to an existing cluster. While a hard-sphere equation is frequently used to predict the condensation rate coefficient, this equation neglects the influences of potential interactions and cluster internal energy on the condensation process. Here, we present a collision rate theory-molecular dynamics simulation approach to calculate condensation probabilities and condensation rate coefficients. We use this approach to examine atomic condensation onto 6-56-atom Au and Mg clusters. The probability of condensation depends upon the initial relative velocity (v) between atom and cluster and the initial impact parameter (b). In all cases, there is a well-defined region of b-v space where condensation is highly probable, and outside of which the condensation probability drops to zero. For Au clusters with more than 10 atoms, we find that at gas temperatures in the 300-1200 K range, the condensation rate coefficient exceeds the hard-sphere rate coefficient by a factor of 1.5-2.0. Conversely, for Au clusters with 10 or fewer atoms and for 14- and 28-atom Mg clusters, as cluster equilibration temperature increases, the condensation rate coefficient drops to values below the hard-sphere rate coefficient. Calculations also yield the self-dissociation rate coefficient, which is found to vary considerably with gas temperature. Finally, calculations results reveal that grazing (high b) atom-cluster collisions at elevated velocity (>1000 m s -1 ) can result in the colliding atom rebounding (bounce) from the cluster surface or binding while another atom dissociates (replacement). The presented method can be applied in developing rate equations to predict material formation and growth rates in vapor phase systems.

Condensation and dissociation rates for gas phase metal clusters from molecular dynamics trajectory calculations

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

Yang, Huan; Goudeli, Eirini; Hogan, Christopher J.

In gas phase synthesis systems, clusters form and grow via condensation, in which a monomer binds to an existing cluster. While a hard sphere equation is frequently used to predict the condensation rate coefficient, this equation neglects the influences of potential interactions and cluster internal energy on the condensation process. Here, we present a collision rate theory-Molecular Dynamics simulation approach to calculate condensation probabilities and condensation rate coefficients; we use this approach to examine atomic condensation onto 6-56 atom Au and Mg clusters. The probability of condensation depends upon the initial relative velocity ( v) between atom and cluster andmore » the initial impact parameter ( b). In all cases there is a well-defined region of b-v space where condensation is highly probable, and outside of which the condensation probability drops to zero. For Au clusters with more than 10 atoms, we find that at gas temperatures in the 300-1200 K range, the condensation rate coefficient exceeds the hard sphere rate coefficient by a factor of 1.5-2.0. Conversely, for Au clusters with 10 or fewer atoms, and for 14 atom and 28 atom Mg clusters, as cluster equilibration temperature increases the condensation rate coefficient drops to values below the hard sphere rate coefficient. Calculations also yield the self-dissociation rate coefficient, which is found to vary considerably with gas temperature. Finally, calculations results reveal that grazing (high b) atom-cluster collisions at elevated velocity (> 1000 m s -1) can result in the colliding atom rebounding (bounce) from the cluster surface or binding while another atom dissociates (replacement). In conclusion, the presented method can be applied in developing rate equations to predict material formation and growth rates in vapor phase systems.« less

Condensation and dissociation rates for gas phase metal clusters from molecular dynamics trajectory calculations

NASA Astrophysics Data System (ADS)

Yang, Huan; Goudeli, Eirini; Hogan, Christopher J.

2018-04-01

In gas phase synthesis systems, clusters form and grow via condensation, in which a monomer binds to an existing cluster. While a hard-sphere equation is frequently used to predict the condensation rate coefficient, this equation neglects the influences of potential interactions and cluster internal energy on the condensation process. Here, we present a collision rate theory-molecular dynamics simulation approach to calculate condensation probabilities and condensation rate coefficients. We use this approach to examine atomic condensation onto 6-56-atom Au and Mg clusters. The probability of condensation depends upon the initial relative velocity (v) between atom and cluster and the initial impact parameter (b). In all cases, there is a well-defined region of b-v space where condensation is highly probable, and outside of which the condensation probability drops to zero. For Au clusters with more than 10 atoms, we find that at gas temperatures in the 300-1200 K range, the condensation rate coefficient exceeds the hard-sphere rate coefficient by a factor of 1.5-2.0. Conversely, for Au clusters with 10 or fewer atoms and for 14- and 28-atom Mg clusters, as cluster equilibration temperature increases, the condensation rate coefficient drops to values below the hard-sphere rate coefficient. Calculations also yield the self-dissociation rate coefficient, which is found to vary considerably with gas temperature. Finally, calculations results reveal that grazing (high b) atom-cluster collisions at elevated velocity (>1000 m s-1) can result in the colliding atom rebounding (bounce) from the cluster surface or binding while another atom dissociates (replacement). The presented method can be applied in developing rate equations to predict material formation and growth rates in vapor phase systems.

Performance and Reliability of Bonded Interfaces for High-temperature Packaging: Annual Progress Report

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

DeVoto, Douglas J.

2017-10-19

As maximum device temperatures approach 200 °Celsius, continuous operation, sintered silver materials promise to maintain bonds at these high temperatures without excessive degradation rates. A detailed characterization of the thermal performance and reliability of sintered silver materials and processes has been initiated for the next year. Future steps in crack modeling include efforts to simulate crack propagation directly using the extended finite element method (X-FEM), a numerical technique that uses the partition of unity method for modeling discontinuities such as cracks in a system.

N-15 NMR Spectroscopy as a Method for Comparing the Rates of Imidization of Several Diamines

NASA Technical Reports Server (NTRS)

Johnson, J. Christopher; Kuczmarski, Maria A.

2006-01-01

The relative rates of the conversion of amide-acid to imide was measured for a series or aromatic diamines that have been identified as potential replacements for 4,4'-methylene dianiline (MDA) in high-temperature polyimides and polymer composites. These rates were compared with the N-15 NMR resonances of the unreacted amines. The initial rates of imidization track with the difference in chemical shift between the amine nitrogens in MDA and those in the subject diamines. This comparison demonstrated that N-15 NMR spectroscopy is appropriate for the rapid screening of candidate diamines to determine their reactivity relative to MDA, and can serve to provide guidance to the process of creating the time-temperature profiles used in processing these materials into polymer matrix composites.

Birth rates for U.S. teenagers reach historic lows for all age and ethnic groups.

PubMed

Hamilton, Brady E; Ventura, Stephanie J

2012-04-01

The widespread significant declines in teen childbearing that began after 1991 have strengthened in recent years. The teen birth rate dropped 17 percent from 2007 through 2010, a record low, and 44 percent from 1991. Rates fell across all teen age groups, racial and ethnic groups, and nearly all states. The drop in the U.S. rate has importantly affected the number of births to teenagers. If the 1991 rates had prevailed through the years 1992–2010, there would have been an estimated 3.4 million additional births to teenagers during that period. The impact of strong pregnancy prevention messages directed to teenagers has been credited with the birth rate declines (9–11). Recently released data from the National Survey of Family Growth, conducted by the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics (NCHS), have shown increased use of contraception at first initiation of sex and use of dual methods of contraception (that is, condoms and hormonal methods) among sexually active female and male teenagers. These trends may have contributed to the recent birth rate declines (12). All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

Identifying Important Attributes for Prognostic Prediction in Traumatic Brain Injury Patients. A Hybrid Method of Decision Tree and Neural Network.

PubMed

Pourahmad, Saeedeh; Hafizi-Rastani, Iman; Khalili, Hosseinali; Paydar, Shahram

2016-10-17

Generally, traumatic brain injury (TBI) patients do not have a stable condition, particularly after the first week of TBI. Hence, indicating the attributes in prognosis through a prediction model is of utmost importance since it helps caregivers with treatment-decision options, or prepares the relatives for the most-likely outcome. This study attempted to determine and order the attributes in prognostic prediction in TBI patients, based on early clinical findings. A hybrid method was employed, which combines a decision tree (DT) and an artificial neural network (ANN) in order to improve the modeling process. The DT approach was applied as the initial analysis of the network architecture to increase accuracy in prediction. Afterwards, the ANN structure was mapped from the initial DT based on a part of the data. Subsequently, the designed network was trained and validated by the remaining data. 5-fold cross-validation method was applied to train the network. The area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, and accuracy rate were utilized as performance measures. The important attributes were then determined from the trained network using two methods: change of mean squared error (MSE), and sensitivity analysis (SA). The hybrid method offered better results compared to the DT method. The accuracy rate of 86.3 % vs. 82.2 %, sensitivity value of 55.1 % vs. 47.6 %, specificity value of 93.6 % vs. 91.1 %, and the area under the ROC curve of 0.705 vs. 0.695 were achieved for the hybrid method and DT, respectively. However, the attributes' order by DT method was more consistent with the clinical literature. The combination of different modeling methods can enhance their performance. However, it may create some complexities in computations and interpretations. The outcome of the present study could deliver some useful hints in prognostic prediction on the basis of early clinical findings for TBI patients.

Effect of Initial Conditions on Reproducibility of Scientific Research

PubMed Central

Djulbegovic, Benjamin; Hozo, Iztok

2014-01-01

Background: It is estimated that about half of currently published research cannot be reproduced. Many reasons have been offered as explanations for failure to reproduce scientific research findings- from fraud to the issues related to design, conduct, analysis, or publishing scientific research. We also postulate a sensitive dependency on initial conditions by which small changes can result in the large differences in the research findings when attempted to be reproduced at later times. Methods: We employed a simple logistic regression equation to model the effect of covariates on the initial study findings. We then fed the input from the logistic equation into a logistic map function to model stability of the results in repeated experiments over time. We illustrate the approach by modeling effects of different factors on the choice of correct treatment. Results: We found that reproducibility of the study findings depended both on the initial values of all independent variables and the rate of change in the baseline conditions, the latter being more important. When the changes in the baseline conditions vary by about 3.5 to about 4 in between experiments, no research findings could be reproduced. However, when the rate of change between the experiments is ≤2.5 the results become highly predictable between the experiments. Conclusions: Many results cannot be reproduced because of the changes in the initial conditions between the experiments. Better control of the baseline conditions in-between the experiments may help improve reproducibility of scientific findings. PMID:25132705

Screen test for cadmium and nickel plates as developed and used within the Aerospace Corporation

NASA Technical Reports Server (NTRS)

Phan, A. H.; Zimmerman, A. H.

1994-01-01

A new procedure described here was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

Stability of Ertapenem 100 mg/mL in Manufacturer’s Glass Vials or Syringes at 4°C and 23°C

PubMed Central

Walker, Scott E; Law, Shirley; Perks, William; Iazzetta, John

2015-01-01

Background: Prophylactic administration of ertapenem as a single 1-g IV dose has been shown to reduce sepsis after prostate biopsy. Objective: To evaluate the stability of ertapenem after reconstitution with 0.9% sodium chloride to a final concentration of 100 mg/mL and storage in the manufacturer’s original glass vials or polypropylene syringes. Methods: On study day 0, 100 mg/mL solutions of ertapenem were retained in the manufacturer’s glass vials or packaged in polypropylene syringes and stored at 4°C or 23°C without protection from fluorescent room light. Samples were assayed periodically over 18 days using a validated, stability-indicating liquid chromatographic method with ultra-violet detection. A beyond-use date was determined as the time for the concentration to decline to 90% of the initial (day 0) concentration, based on the fastest degradation rate, with 95% confidence. Results: Reconstituted solutions stored in the manufacturer’s glass vials or polypropylene syringes exhibited a first-order degradation rate, such that 10% of the initial concentration was lost in the first 2.5 days when stored at 4°C or within the first 6.75 h when stored at room temperature (23°C). Analysis of variance showed differences in the percentage remaining due to temperature (p < 0.001) and study day (p < 0.001) but not type of container (p = 0.98). When a 95% CI for the degradation rate was calculated and used to determine a beyond-use date, it was established that more than 90% of the initial concentration would remain for 2.35 days at 4°C and for 0.23 day (about 5 h, 30 min) at room temperature. Conclusions: A 100 mg/mL ertapenem solution stored in the manufacturer’s glass vial or a polypropylene syringe will retain more than 90.5% of the initial concentration when stored for 48 h at 4°C and for an additional 1 h at 23°C. PMID:25964683

Simultaneous 3D–2D image registration and C-arm calibration: Application to endovascular image-guided interventions

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

Mitrović, Uroš; Pernuš, Franjo; Likar, Boštjan

Purpose: Three-dimensional to two-dimensional (3D–2D) image registration is a key to fusion and simultaneous visualization of valuable information contained in 3D pre-interventional and 2D intra-interventional images with the final goal of image guidance of a procedure. In this paper, the authors focus on 3D–2D image registration within the context of intracranial endovascular image-guided interventions (EIGIs), where the 3D and 2D images are generally acquired with the same C-arm system. The accuracy and robustness of any 3D–2D registration method, to be used in a clinical setting, is influenced by (1) the method itself, (2) uncertainty of initial pose of the 3Dmore » image from which registration starts, (3) uncertainty of C-arm’s geometry and pose, and (4) the number of 2D intra-interventional images used for registration, which is generally one and at most two. The study of these influences requires rigorous and objective validation of any 3D–2D registration method against a highly accurate reference or “gold standard” registration, performed on clinical image datasets acquired in the context of the intervention. Methods: The registration process is split into two sequential, i.e., initial and final, registration stages. The initial stage is either machine-based or template matching. The latter aims to reduce possibly large in-plane translation errors by matching a projection of the 3D vessel model and 2D image. In the final registration stage, four state-of-the-art intrinsic image-based 3D–2D registration methods, which involve simultaneous refinement of rigid-body and C-arm parameters, are evaluated. For objective validation, the authors acquired an image database of 15 patients undergoing cerebral EIGI, for which accurate gold standard registrations were established by fiducial marker coregistration. Results: Based on target registration error, the obtained success rates of 3D to a single 2D image registration after initial machine-based and template matching and final registration involving C-arm calibration were 36%, 73%, and 93%, respectively, while registration accuracy of 0.59 mm was the best after final registration. By compensating in-plane translation errors by initial template matching, the success rates achieved after the final stage improved consistently for all methods, especially if C-arm calibration was performed simultaneously with the 3D–2D image registration. Conclusions: Because the tested methods perform simultaneous C-arm calibration and 3D–2D registration based solely on anatomical information, they have a high potential for automation and thus for an immediate integration into current interventional workflow. One of the authors’ main contributions is also comprehensive and representative validation performed under realistic conditions as encountered during cerebral EIGI.« less

Every antibiotic, every day: Maximizing the impact of prospective audit and feedback on total antibiotic use

PubMed Central

Decloe, Melissa; Gill, Suzanne; Ho, Grace; McCready, Janine; Powis, Jeff

2017-01-01

Background The success of antimicrobial stewardship is dependent on how often it is completed and which antimicrobials are targeted. We evaluated the impact of an antimicrobial stewardship program (ASP) in three non-ICU settings where all systemic antibiotics, regardless of spectrum, were targeted on the first weekday after initiation. Methods Prospective audit and feedback (PAAF) was initiated on the surgical, respiratory, and medical wards of a community hospital on July 1, 2010, October 1, 2010, and April 1, 2012, respectively. We evaluated rates of total antibiotic use, measured in days on therapy (DOTs), among all patients admitted to the wards before and after PAAF initiation using an interrupted time series analysis. Changes in antibiotic costs, rates of C. difficile infection (CDI), mortality, readmission, and length of stay were evaluated using univariate analyses. Results Time series modelling demonstrated that total antibiotic use decreased (± standard error) by 100 ± 51 DOTs/1,000 patient-days on the surgical wards (p = 0.049), 100 ± 46 DOTs/1,000 patient-days on the respiratory ward (p = 0.029), and 91 ± 33 DOTs/1,000 patient-days on the medical wards (p = 0.006) immediately following PAAF initiation. Reductions in antibiotic use were sustained up to 50 months after intervention initiation, and were accompanied by decreases in antibiotic costs. There were no significant changes to patient outcomes on the surgical and respiratory wards following intervention initiation. On the medical wards, however, readmission increased from 4.6 to 5.6 per 1,000 patient-days (p = 0.043), while mortality decreased from 7.4 to 5.0 per 1,000 patient-days (p = 0.001). CDI rates showed a non-significant declining trend after PAAF initiation. Conclusions ASPs can lead to cost-effective, sustained reductions in total antibiotic use when interventions are conducted early in the course of therapy and target all antibiotics. Shifting to such a model may help strengthen the effectiveness of ASPs in non-ICU settings. PMID:28562638

Simultaneous PET-MRI Studies of the Concordance of Atrophy and Hypometabolism in Syndromic Variants of Alzheimer's Disease and Frontotemporal Dementia: An Extended Case Series.

PubMed

Moodley, Kuven K; Perani, Daniela; Minati, Ludovico; Della Rosa, Pasquale Anthony; Pennycook, Frank; Dickson, John C; Barnes, Anna; Contarino, Valeria Elisa; Michopoulou, Sofia; D'Incerti, Ludovico; Good, Catriona; Fallanca, Federico; Vanoli, Emilia Giovanna; Ell, Peter J; Chan, Dennis

2015-01-01

Simultaneous PET-MRI is used to compare patterns of cerebral hypometabolism and atrophy in six different dementia syndromes. The primary objective was to conduct an initial exploratory study regarding the concordance of atrophy and hypometabolism in syndromic variants of Alzheimer's disease (AD) and frontotemporal dementia (FTD). The secondary objective was to determine the effect of image analysis methods on determination of atrophy and hypometabolism. PET and MRI data were acquired simultaneously on 24 subjects with six variants of AD and FTD (n = 4 per group). Atrophy was rated visually and also quantified with measures of cortical thickness. Hypometabolism was rated visually and also quantified using atlas- and SPM-based approaches. Concordance was measured using weighted Cohen's kappa. Atrophy-hypometabolism concordance differed markedly between patient groups; kappa scores ranged from 0.13 (nonfluent/agrammatic variant of primary progressive aphasia, nfvPPA) to 0.49 (posterior cortical variant of AD, PCA). Heterogeneity was also observed within groups; the confidence intervals of kappa scores ranging from 0-0.25 for PCA to 0.29-0.61 for nfvPPA. More widespread MRI and PET changes were identified using quantitative methods than on visual rating. The marked differences in concordance identified in this initial study may reflect differences in the molecular pathologies underlying AD and FTD syndromic variants but also operational differences in the methods used to diagnose these syndromes. The superior ability of quantitative methodologies to detect changes on PET and MRI, if confirmed on larger cohorts, may favor their usage over qualitative visual inspection in future clinical diagnostic practice.

Oppositional Defiant Disorder toward Adults and Oppositional Defiant Disorder toward Peers: Initial Evidence for Two Separate Constructs

ERIC Educational Resources Information Center

Taylor, Ted K.; Burns, G. Leonard; Rusby, Julie C.; Foster, E. Michael

2006-01-01

Confirmatory factor analysis of 25 items on the Child and Adolescent Disruptive Behavior Inventory (CADBI, Version 2.3; G. L. Burns, T. K. Taylor, & J. C. Rusby, 2001) was conducted on teacher ratings of 824 kindergarten children and replicated on 534 children. Model fit was improved when correcting for 2 method effects: (a) adjacent items and…

40 CFR 63.9916 - What test methods and other procedures must I use to establish and demonstrate initial compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... compliance with the operating limits? For a wet scrubber subject to operating limits for pressure drop and scrubber water flow rate in § 63.9890(b), you must establish site-specific operating limits according to... monitoring system (CPMS) required in § 63.9920, measure and record the pressure drop and scrubber water flow...