Analyzing Double Delays at Newark Liberty International Airport

NASA Technical Reports Server (NTRS)

Evans, Antony D.; Lee, Paul

2016-01-01

When weather or congestion impacts the National Airspace System, multiple different Traffic Management Initiatives can be implemented, sometimes with unintended consequences. One particular inefficiency that is commonly identified is in the interaction between Ground Delay Programs (GDPs) and time based metering of internal departures, or TMA scheduling. Internal departures under TMA scheduling can take large GDP delays, followed by large TMA scheduling delays, because they cannot be easily fitted into the overhead stream. In this paper we examine the causes of these double delays through an analysis of arrival operations at Newark Liberty International Airport (EWR) from June to August 2010. Depending on how the double delay is defined between 0.3 percent and 0.8 percent of arrivals at EWR experienced double delays in this period. However, this represents between 21 percent and 62 percent of all internal departures in GDP and TMA scheduling. A deep dive into the data reveals that two causes of high internal departure scheduling delays are upstream flights making up time between their estimated departure clearance times (EDCTs) and entry into time based metering, which undermines the sequencing and spacing underlying the flight EDCTs, and high demand on TMA, when TMA airborne metering delays are high. Data mining methods (currently) including logistic regression, support vector machines and K-nearest neighbors are used to predict the occurrence of double delays and high internal departure scheduling delays with accuracies up to 0.68. So far, key indicators of double delay and high internal departure scheduling delay are TMA virtual runway queue size, and the degree to which estimated runway demand based on TMA estimated times of arrival has changed relative to the estimated runway demand based on EDCTs. However, more analysis is needed to confirm this.

Dynamic Generation of Reduced Ontologies to Support Resource Constraints of Mobile Devices

ERIC Educational Resources Information Center

Schrimpsher, Dan

2011-01-01

As Web Services and the Semantic Web become more important, enabling technologies such as web service ontologies will grow larger. At the same time, use of mobile devices to access web services has doubled in the last year. The ability of these resource constrained devices to download and reason across these ontologies to support service discovery…

Effects of two trimming methods of dairy cattle on concrete or rubber-covered slatted floors.

PubMed

Ouweltjes, W; Holzhauer, M; van der Tol, P P J; van der Werf, J

2009-03-01

This study monitored claw health, claw conformation, locomotion, activity, and step traits of cows from a single dairy herd that were trimmed according to the standard Dutch method or with an alternative "concave" trimming method. Half of the cows were kept in a stall section with concrete slatted floors in the alleys. The other cows were kept in a pen within the same housing with an identical concrete slatted floor in the alleys, but with a rubber top layer. All experimental cows were kept in the same environment for at least 3 mo before and after trimming. It was hypothesized that trimming for more-concave soles (i.e., with 3 to 5 mm of sole dug out under the claw bone) was preferred to the standard Dutch trimming with flat sole surfaces for cows kept in stalls with soft alley floors. None of the claw health or locomotion traits differed for the trimming methods. No interactions were found between flooring and trimming method. Floor effects were significant for several traits. Cows on the rubber-topped floors had significantly fewer sole hemorrhages (prevalence of 22 vs. 48% in mo 3) and larger claws (claw length 76.1 +/- 5.0 vs. 72.5 +/- 4.9 mm; heel height 49.3 +/- 6.3 vs. 46.0 +/- 6.4 mm; claw diagonal 129 +/- 6.4 vs. 125 +/- 6.9 mm), spent more time standing in the alleys (55.4 +/- 2.8 vs. 49.6 +/- 2.8%), and had higher activity (61.0 +/- 3.7 vs. 53.0 +/- 3.7 steps/h). This suggests greater claw comfort on rubber flooring compared with concrete flooring. Kinetic patterns during claw-floor contact while walking were similar for all treatments. During the double-support (stance) phase, claw-floor contact area increased to a maximum in the first 30% of double-support phase time, remained more or less stable until 80% of double-support phase time, and sharply decreased as the animal pushed off as shown by the change in center of pressure. A gradual change of center of pressure in the medial direction during double-support phase time was shown. The research hypothesis was rejected, but soft alley floors had subtle beneficial effects.

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

NASA Astrophysics Data System (ADS)

Ahmed, Nesreen S.; Menzel, Robert; Wang, Yifan; Garcia-Gallastegui, Ainara; Bawaked, Salem M.; Obaid, Abdullah Y.; Basahel, Sulaiman N.; Mokhtar, Mohamed

2017-02-01

Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

Gender and ergonomics: a case study on the 'non-formal' work of women nurses.

PubMed

Salerno, Silvana; Livigni, Lucilla; Magrini, Andrea; Talamanca, Irene Figà

2012-01-01

Women's work activities are often characterised by 'non-formal actions' (such as giving support). Gender differences in ergonomics may be due to this peculiarity. We applied the method of organisational congruencies (MOC) to ascertain the 'non-formal' work portion of nurses employed in three hospital units (haematology, emergency room and general medicine) during the three work shifts in a major University Hospital in Rome, Italy. We recorded a total of 802 technical actions performed by nine nurses in 72 h of work. Twenty-six percent of the actions in direct patient's care were communicative actions (mainly giving psychological support) while providing physical care. These 'double actions' are often not considered to be a formal part of the job by hospital management. In our case study, the 'non-formal' work of nurses (psychological support) is mainly represented by double actions while taking physical care of the patients. The dual task paradigm in gender oriented research is discussed in terms of its implications in prevention in occupational health. The main purpose of the study was to assess all the formal and non-formal activities of women in the nursing work setting. Offering psychological support to patients is often not considered to be a formal part of the job. Our case study found that nurses receive no explicit guidelines on this activity and no time is assigned to perform it. In measuring the burden of providing psychological support to patients, we found that this is often done while nurses are performing tasks of physical care for the patients (double actions). The article discusses the significance of non-formal psychological work load of women nurses through double actions from the ergonomic point view.

Double photoionization of Be-like (Be-F5+) ions

NASA Astrophysics Data System (ADS)

Abdel Naby, Shahin; Pindzola, Michael; Colgan, James

2015-04-01

The time-dependent close-coupling method is used to study the single photon double ionization of Be-like (Be - F5+) ions. Energy and angle differential cross sections are calculated to fully investigate the correlated motion of the two photoelectrons. Symmetric and antisymmetric amplitudes are presented along the isoelectronic sequence for different energy sharing of the emitted electrons. Our total double photoionization cross sections are in good agreement with available theoretical results and experimental measurements along the Be-like ions. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California and the National Institute for Computational Sciences in Knoxville, Tennessee.

The use of tobacco tax revenues to fund the Guam Cancer Registry: A double win for cancer control.

PubMed

David, Annette M; Haddock, Robert L; Bordallo, Renata; Dirige, Janet T; Mery, Les

2017-06-01

Cancer registries that provide reliable data on cancer incidence, mortality and burden are essential to cancer control. However, establishing sustainable local funding mechanisms to support cancer registries remains a challenge in many countries. Guam, an unincorporated Territory of the United States of America in the Western Pacific, enacted a bill that raised tobacco taxes, and earmarked a percentage of tobacco tax revenues to support its Cancer Registry. This provided a reliable funding stream for the Registry, allowing for continued staffing and capacity building; at the same time, youth tobacco consumption decreased following the tax increase. Linking tobacco tax revenues to cancer registry support is a feasible strategy with a double benefit: higher tobacco prices from higher tobacco taxes reduce tobacco-related cancer risk while assuring the long-term viability of systematic cancer data collection and dissemination.

The use of tobacco tax revenues to fund the Guam Cancer Registry: A double win for cancer control

PubMed Central

David, Annette M.; Haddock, Robert L; Bordallo, Renata; Dirige, Janet T.; Mery, Les

2017-01-01

Cancer registries that provide reliable data on cancer incidence, mortality and burden are essential to cancer control. However, establishing sustainable local funding mechanisms to support cancer registries remains a challenge in many countries. Guam, an unincorporated Territory of the United States of America in the Western Pacific, enacted a bill that raised tobacco taxes, and earmarked a percentage of tobacco tax revenues to support its Cancer Registry. This provided a reliable funding stream for the Registry, allowing for continued staffing and capacity building; at the same time, youth tobacco consumption decreased following the tax increase. Linking tobacco tax revenues to cancer registry support is a feasible strategy with a double benefit: higher tobacco prices from higher tobacco taxes reduce tobacco-related cancer risk while assuring the long-term viability of systematic cancer data collection and dissemination. PMID:29130031

Interlimb relation during the double support phase of gait: an electromyographic, mechanical and energy-based analysis.

PubMed

Sousa, Andreia S P; Silva, Augusta; Tavares, João Manuel R S

2013-03-01

The purpose of this study is to analyse the interlimb relation and the influence of mechanical energy on metabolic energy expenditure during gait. In total, 22 subjects were monitored as to electromyographic activity, ground reaction forces and VO2 consumption (metabolic power) during gait. The results demonstrate a moderate negative correlation between the activity of tibialis anterior, biceps femoris and vastus medialis of the trailing limb during the transition between mid-stance and double support and that of the leading limb during double support for the same muscles, and between these and gastrocnemius medialis and soleus of the trailing limb during double support. Trailing limb soleus during the transition between mid-stance and double support was positively correlated to leading limb tibialis anterior, vastus medialis and biceps femoris during double support. Also, the trailing limb centre of mass mechanical work was strongly influenced by the leading limbs, although only the mechanical power related to forward progression of both limbs was correlated to metabolic power. These findings demonstrate a consistent interlimb relation in terms of electromyographic activity and centre of mass mechanical work, being the relations occurred in the plane of forward progression the more important to gait energy expenditure.

The Behavioral Economics of Choice and Interval Timing

PubMed Central

Jozefowiez, J.; Staddon, J. E. R.; Cerutti, D. T.

2009-01-01

We propose a simple behavioral economic model (BEM) describing how reinforcement and interval timing interact. The model assumes a Weber-law-compliant logarithmic representation of time. Associated with each represented time value are the payoffs that have been obtained for each possible response. At a given real time, the response with the highest payoff is emitted. The model accounts for a wide range of data from procedures such as simple bisection, metacognition in animals, economic effects in free-operant psychophysical procedures and paradoxical choice in double-bisection procedures. Although it assumes logarithmic time representation, it can also account for data from the time-left procedure usually cited in support of linear time representation. It encounters some difficulties in complex free-operant choice procedures, such as concurrent mixed fixed-interval schedules as well as some of the data on double bisection, that may involve additional processes. Overall, BEM provides a theoretical framework for understanding how reinforcement and interval timing work together to determine choice between temporally differentiated reinforcers. PMID:19618985

Photoionization of Ne8+

NASA Astrophysics Data System (ADS)

Pindzola, M. S.; Abdel-Naby, Sh. A.; Robicheaux, F.; Colgan, J.

2014-05-01

Single and double photoionization cross sections for Ne8+ are calculated using a non-perturbative fully relativistic time-dependent close-coupling method. A Bessel function expansion is used to include both dipole and quadrupole effects in the radiation field interaction and the repulsive interaction between electrons includes both the Coulomb and Gaunt interactions. The fully correlated ground state of Ne8+ is obtained by solving a time-independent inhomogeneous set of close-coupled equations. Propagation of the time-dependent close-coupled equations yields single and double photoionization cross sections for Ne8+ at energies easily accessible at advanced free electron laser facilities. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California, NICS in Knoxville, Tennessee, and OLCF in Oak Ridge, Tennessee.

Research and Development Supporting a Next Generation Germanium Double Beta Decay Experiment

NASA Astrophysics Data System (ADS)

Rielage, Keith; Elliott, Steve; Chu, Pinghan; Goett, Johnny; Massarczyk, Ralph; Xu, Wenqin

2015-10-01

To improve the search for neutrinoless double beta decay, the next-generation experiments will increase in source mass and continue to reduce backgrounds in the region of interest. A promising technology for the next generation experiment is large arrays of Germanium p-type point contact detectors enriched in 76-Ge. The experience, expertise and lessons learned from the MAJORANA DEMONSTRATOR and GERDA experiments naturally lead to a number of research and development activities that will be useful in guiding a future experiment utilizing Germanium. We will discuss some R&D activities including a hybrid cryostat design, background reduction in cabling, connectors and electronics, and modifications to reduce assembly time. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

Multi Laser Pulse Investigation of the DEAS Concept in Hypersonic Flow

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

Minucci, M.A.S.; Toro, P.G.P.; Oliveira, A.C.

2004-03-30

The present paper presents recent experimental results on the Laser-Supported Directed Energy 'Air Spike' - DEAS in hypersonic flow achieved by the Laboratory of Aerothermodynamics and Hypersonics - LAH, Brazil. Two CO2 TEA lasers, sharing the same optical cavity, have been used in conjunction with the IEAv 0.3m Hypersonic Shock Tunnel - HST to demonstrate the Laser-Supported DEAS concept. A single and double laser pulse, generated during the tunnel useful test time, were focused through a NaCl lens upstream of a Double Apollo Disc model fitted with seven piezoelectric pressure transducers and six platinum thin film heat transfer gauges. Themore » objective being to corroborate previous results as well as to obtain additional pressure and heat flux distributions information when two laser pulses are used.« less

Time-series Spectroscopy of Two Candidate Double Degenerates in the Open Cluster NGC 6633

NASA Astrophysics Data System (ADS)

Williams, Kurtis A.; Serna-Grey, Donald; Chakraborty, Subho; Gianninas, A.; Canton, Paul A.

2015-12-01

SNe Ia are heavily used tools in precision cosmology, yet we still are not certain what the progenitor systems are. General plausibility arguments suggest there is potential for identifying double degenerate SN Ia progenitors in intermediate-age open star clusters. We present time-resolved high-resolution spectroscopy of two white dwarfs (WDs) in the field of the open cluster NGC 6633 that had previously been identified as candidate double degenerates in the cluster. However, three hours of continuous observations of each candidate failed to detect any significant radial velocity variations at the ≳10 km s-1 level, making it highly unlikely that either WD is a double degenerate that will merge within a Hubble Time. The WD LAWDS NGC 6633 4 has a radial velocity inconsistent with cluster membership at the 2.5σ level, while the radial velocity of LAWDS NGC 6633 7 is consistent with cluster membership. We conservatively conclude that LAWDS 7 is a viable massive double degenerate candidate, though unlikely to be a Type Ia progenitor. Astrometric data from GAIA will likely be needed to determine if either WD is truly a cluster member. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Influence of restricted vision and knee joint range of motion on gait properties during level walking and stair ascent and descent.

PubMed

Demura, Tomohiro; Demura, Shin-ich

2011-01-01

Because elderly individuals experience marked declines in various physical functions (e.g., vision, joint function) simultaneously, it is difficult to clarify the individual effects of these functional declines on walking. However, by imposing vision and joint function restrictions on young men, the effects of these functional declines on walking can be clarified. The authors aimed to determine the effect of restricted vision and range of motion (ROM) of the knee joint on gait properties while walking and ascending or descending stairs. Fifteen healthy young adults performed level walking and stair ascent and descent during control, vision restriction, and knee joint ROM restriction conditions. During level walking, walking speed and step width decreased, and double support time increased significantly with vision and knee joint ROM restrictions. Stance time, step width, and walking angle increased only with knee joint ROM restriction. Stance time, swing time, and double support time were significantly longer in level walking, stair descent, and stair ascent, in that order. The effects of vision and knee joint ROM restrictions were significantly larger than the control conditions. In conclusion, vision and knee joint ROM restrictions affect gait during level walking and stair ascent and descent. This effect is marked in stair ascent with knee joint ROM restriction.

Examination of factors affecting gait properties in healthy older adults: focusing on knee extension strength, visual acuity, and knee joint pain.

PubMed

Demura, Tomohiro; Demura, Shin-ichi; Uchiyama, Masanobu; Sugiura, Hiroki

2014-01-01

Gait properties change with age because of a decrease in lower limb strength and visual acuity or knee joint disorders. Gait changes commonly result from these combined factors. This study aimed to examine the effects of knee extension strength, visual acuity, and knee joint pain on gait properties of for 181 healthy female older adults (age: 76.1 (5.7) years). Walking speed, cadence, stance time, swing time, double support time, step length, step width, walking angle, and toe angle were selected as gait parameters. Knee extension strength was measured by isometric dynamometry; and decreased visual acuity and knee joint pain were evaluated by subjective judgment whether or not such factors created a hindrance during walking. Among older adults without vision problems and knee joint pain that affected walking, those with superior knee extension strength had significantly greater walking speed and step length than those with inferior knee extension strength (P < .05). Persons with visual acuity problems had higher cadence and shorter stance time. In addition, persons with pain in both knees showed slower walking speed and longer stance time and double support time. A decrease of knee extension strength and visual acuity and knee joint pain are factors affecting gait in the female older adults. Decreased knee extension strength and knee joint pain mainly affect respective distance and time parameters of the gait.

Dynamics of corticospinal motor control during overground and treadmill walking in humans.

PubMed

Roeder, Luisa; Boonstra, Tjeerd Willem; Smith, Simon S; Kerr, Graham K

2018-05-30

Increasing evidence suggests cortical involvement in the control of human gait. However, the nature of corticospinal interactions remains poorly understood. We performed time-frequency analysis of electrophysiological activity acquired during treadmill and overground walking in 22 healthy, young adults. Participants walked at their preferred speed (4.2, SD 0.4 km h -1 ), which was matched across both gait conditions. Event-related power, corticomuscular coherence (CMC) and inter-trial coherence (ITC) were assessed for EEG from bilateral sensorimotor cortices and EMG from the bilateral tibialis anterior (TA) muscles. Cortical power, CMC and ITC at theta, alpha, beta and gamma frequencies (4-45 Hz) increased during the double support phase of the gait cycle for both overground and treadmill walking. High beta (21-30 Hz) CMC and ITC of EMG was significantly increased during overground compared to treadmill walking, as well as EEG power in theta band (4-7 Hz). The phase spectra revealed positive time lags at alpha, beta and gamma frequencies, indicating that the EEG response preceded the EMG response. The parallel increases in power, CMC and ITC during double support suggest evoked responses at spinal and cortical populations rather than a modulation of ongoing corticospinal oscillatory interactions. The evoked responses are not consistent with the idea of synchronization of ongoing corticospinal oscillations, but instead suggest coordinated cortical and spinal inputs during the double support phase. Frequency-band dependent differences in power, CMC and ITC between overground and treadmill walking suggest differing neural control for the two gait modalities, emphasizing the task-dependent nature of neural processes during human walking.

One-pot synthesis of carbon supported calcined-Mg/Al layered double hydroxides for antibiotic removal by slow pyrolysis of biomass waste

PubMed Central

Tan, Xiaofei; Liu, Shaobo; Liu, Yunguo; Gu, Yanling; Zeng, Guangming; Cai, Xiaoxi; Yan, ZhiLi; Yang, Chunping; Hu, Xinjiang; Chen, Bo

2016-01-01

A biochar supported calcined-Mg/Al layered double hydroxides composite (CLDHs/BC) was synthesized by a one-pot slow pyrolysis of LDHs preloaded bagasse biomass. Multiple characterizations of the product illustrated that the calcined-Mg/Al layered double hydroxides (CLDHs) were successfully coated onto the biochar in slow pyrolysis of pre-treated biomass. The as-synthesized CLDHs/BC could efficiently remove antibiotic tetracycline from aqueous solutions. The coating of CLDHs significantly increased the adsorption ability of biochar, and CLDHs/BC exhibited more than 2 times higher adsorption capacity than that of the pristine biochar (BC) in the tested pH range. The maximum adsorption capacity of CLDHs/BC for tetracycline was 1118.12 mg/g at 318 K. The experimental results suggested that the interaction with LDHs on biochar played a dominant role in tetracycline adsorption, accompanied with π–π interaction and hydrogen bond. This study provides a feasible and simple approach for the preparation of high-performance material for antibiotics contaminated wastewater treatment in a cost-effective way. PMID:28000759

One-pot synthesis of carbon supported calcined-Mg/Al layered double hydroxides for antibiotic removal by slow pyrolysis of biomass waste

NASA Astrophysics Data System (ADS)

Tan, Xiaofei; Liu, Shaobo; Liu, Yunguo; Gu, Yanling; Zeng, Guangming; Cai, Xiaoxi; Yan, Zhili; Yang, Chunping; Hu, Xinjiang; Chen, Bo

2016-12-01

A biochar supported calcined-Mg/Al layered double hydroxides composite (CLDHs/BC) was synthesized by a one-pot slow pyrolysis of LDHs preloaded bagasse biomass. Multiple characterizations of the product illustrated that the calcined-Mg/Al layered double hydroxides (CLDHs) were successfully coated onto the biochar in slow pyrolysis of pre-treated biomass. The as-synthesized CLDHs/BC could efficiently remove antibiotic tetracycline from aqueous solutions. The coating of CLDHs significantly increased the adsorption ability of biochar, and CLDHs/BC exhibited more than 2 times higher adsorption capacity than that of the pristine biochar (BC) in the tested pH range. The maximum adsorption capacity of CLDHs/BC for tetracycline was 1118.12 mg/g at 318 K. The experimental results suggested that the interaction with LDHs on biochar played a dominant role in tetracycline adsorption, accompanied with π-π interaction and hydrogen bond. This study provides a feasible and simple approach for the preparation of high-performance material for antibiotics contaminated wastewater treatment in a cost-effective way.

A Bright Side to the Work-Family Interface: Husbands' Support as a Resource in Double-and-Triple-Duty Caregiving Wives' Work Lives.

PubMed

DePasquale, Nicole; Polenick, Courtney A; Davis, Kelly D; Berkman, Lisa F; Cabot, Thomas D

2017-06-16

This study examined how women who combine long-term care employment with unpaid, informal caregiving roles for children (double-duty-child caregivers), older adults (double-duty-elder caregivers), and both children and older adults (triple-duty caregivers) differed from their workplace-only caregiving counterparts on workplace factors related to job retention (i.e., job satisfaction and turnover intentions) and performance (i.e., perceived obligation to work while sick and emotional exhaustion). The moderating effects of perceived spouse support were also examined. Regression analyses were conducted on survey data from 546 married, heterosexual women employed in U.S.-based nursing homes. Compared to workplace-only caregivers, double-duty-elder and triple-duty caregivers reported more emotional exhaustion. Double-duty-child caregivers reported lower turnover intentions and both double-and-triple-duty caregivers felt less obligated to work while sick when perceiving greater support from husbands. Results indicate that double-and-triple-duty caregiving women's job retention and obligation to work while sick may depend on perceived spouse support, highlighting the important role husbands play in their wives' professional lives. Findings also lend support to the emerging literature on marriage-to-work positive spillover, and suggest that long-term care organizations should target marital relationships in family-friendly initiatives to retain and engage double-and-triple-duty caregiving employees. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ankle antagonist coactivation in the double-support phase of walking: Stroke vs. healthy subjects.

PubMed

Silva, Augusta; Sousa, Andreia S P; Silva, Cláudia; Tavares, João Manuel R S; Santos, Rubim; Sousa, Filipa

2015-01-01

Lesions in ipsilateral systems related to postural control in the ipsilesional side may justify the lower performance of stroke subjects during walking. To analyze bilateral ankle antagonist coactivation during double support in stroke subjects. Sixteen (8 females; 8 males) subjects with a first isquemic stroke and 22 controls (12 females; 10 males) participated in this study. The double-support phase was assessed through ground reaction forces and the electromyography of ankle muscles was assessed in both limbs. The ipsilesional limb presented statistically significant differences from the control when assuming specific roles during double support. The tibialis anterior and soleus pair was the one in which this atypical behavior was more pronounced. The ipsilesional limb presents a dysfunctional behavior when a higher postural control activity was demanded.

Metronome Cueing of Walking Reduces Gait Variability after a Cerebellar Stroke.

PubMed

Wright, Rachel L; Bevins, Joseph W; Pratt, David; Sackley, Catherine M; Wing, Alan M

2016-01-01

Cerebellar stroke typically results in increased variability during walking. Previous research has suggested that auditory cueing reduces excessive variability in conditions such as Parkinson's disease and post-stroke hemiparesis. The aim of this case report was to investigate whether the use of a metronome cue during walking could reduce excessive variability in gait parameters after a cerebellar stroke. An elderly female with a history of cerebellar stroke and recurrent falling undertook three standard gait trials and three gait trials with an auditory metronome. A Vicon system was used to collect 3-D marker trajectory data. The coefficient of variation was calculated for temporal and spatial gait parameters. SDs of the joint angles were calculated and used to give a measure of joint kinematic variability. Step time, stance time, and double support time variability were reduced with metronome cueing. Variability in the sagittal hip, knee, and ankle angles were reduced to normal values when walking to the metronome. In summary, metronome cueing resulted in a decrease in variability for step, stance, and double support times and joint kinematics. Further research is needed to establish whether a metronome may be useful in gait rehabilitation after cerebellar stroke and whether this leads to a decreased risk of falling.

Metronome Cueing of Walking Reduces Gait Variability after a Cerebellar Stroke

PubMed Central

Wright, Rachel L.; Bevins, Joseph W.; Pratt, David; Sackley, Catherine M.; Wing, Alan M.

2016-01-01

Cerebellar stroke typically results in increased variability during walking. Previous research has suggested that auditory cueing reduces excessive variability in conditions such as Parkinson’s disease and post-stroke hemiparesis. The aim of this case report was to investigate whether the use of a metronome cue during walking could reduce excessive variability in gait parameters after a cerebellar stroke. An elderly female with a history of cerebellar stroke and recurrent falling undertook three standard gait trials and three gait trials with an auditory metronome. A Vicon system was used to collect 3-D marker trajectory data. The coefficient of variation was calculated for temporal and spatial gait parameters. SDs of the joint angles were calculated and used to give a measure of joint kinematic variability. Step time, stance time, and double support time variability were reduced with metronome cueing. Variability in the sagittal hip, knee, and ankle angles were reduced to normal values when walking to the metronome. In summary, metronome cueing resulted in a decrease in variability for step, stance, and double support times and joint kinematics. Further research is needed to establish whether a metronome may be useful in gait rehabilitation after cerebellar stroke and whether this leads to a decreased risk of falling. PMID:27313563

Changes in the physical activity of acute stroke survivors between inpatient and community living with early supported discharge: an observational cohort study.

PubMed

Kerr, A; Rowe, P; Esson, D; Barber, M

2016-12-01

To describe and compare patterns of physical activity among stroke survivors during their hospital stay and community living with early supported discharge. Observational cohort study of physical activity before and after early supported discharge. UK National Health Service stroke units and participants' homes. Forty-one stroke survivors with a mean age of 69 (standard deviation 11) years, and a median Modified Rivermead Mobility Index of 33.5 [interquartile range (IQR) 25.8 to 35.3]. The primary outcome measures were time spent in sitting/standing/walking and number of steps taken, as recorded by a physical activity monitor. There were statistical differences (P<0.001) for all categories of physical activity. After early supported discharge to the community, participants took more than twice the number of steps {median 474 (IQR 189 to 773) vs. 1193 (IQR 512 to 2856), median difference 636 [95% confidence interval (CI) 262 to 931]} and spent more than double the time in standing [median 51 (IQR 22 to 128) minutes vs. 100 (IQR 51 to 178) minutes, median difference 28 (95% CI 11 to 68)] compared with their hospital stay. Community living with early supported discharge promoted higher levels of physical activity in medically stable stroke survivors. The near-doubling of activity may serve as a guideline for what is achievable during stroke rehabilitation. Number UKCRN 15472. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

An Intensification Approach to Double-Block Algebra: A Pilot Implementation of Intensified Algebra in A Large Urban School District

ERIC Educational Resources Information Center

Tidd, Simon T.; Stoelinga, Timothy M.; Bush-Richards, Angela M.; De Sena, Donna L.; Dwyer, Theodore J.

2018-01-01

Double-block instruction has become a popular strategy for supporting struggling mathematics students in algebra I. Despite its widespread adoption, little consistent evidence supports the attributes of a successful double-block design or the effectiveness of this instructional strategy. In this study, the authors examine a pilot implementation of…

Support-Staff Jobs Double in 20 Years, Outpacing Enrollment

ERIC Educational Resources Information Center

Brainard, Jeffrey; Fain, Paul; Masterson, Kathryn

2009-01-01

Colleges have added managers and support personnel at a steady, vigorous clip over the past 20 years, new research shows, far outpacing the growth in student enrollment and instructors. Support staff--like budget analysts, computer specialists, and loan counselors--nearly doubled from 1987 to 2007. Meanwhile, jobs for instructors increased by only…

Development of independent locomotion in children with a severe visual impairment.

PubMed

Hallemans, Ann; Ortibus, Els; Truijen, Steven; Meire, Francoise

2011-01-01

Locomotion of children and adults with a visual impairment (ages 1-44, n = 28) was compared to that of age-related individuals with normal vision (n = 60). Participants walked barefoot at preferred speed while their gait was recorded by a Vicon(®) system. Walking speed, heading angle, step frequency, stride length, step width, stance phase duration and double support time were determined. Differences between groups, relationships with age and possible interaction effects were investigated. With increasing age overall improvements in gait parameters are observed. Differences between groups were a slower walking speed, a shorter stride length, a prolonged duration of stance and of double support in the individuals with a visual impairment. These may be considered either as adaptations to balance problems or as strategies to allow to foot to probe the ground. Copyright © 2011 Elsevier Ltd. All rights reserved.

Towards a model of pion generalized parton distributions from Dyson-Schwinger equations

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

Moutarde, H.

2015-04-10

We compute the pion quark Generalized Parton Distribution H{sup q} and Double Distributions F{sup q} and G{sup q} in a coupled Bethe-Salpeter and Dyson-Schwinger approach. We use simple algebraic expressions inspired by the numerical resolution of Dyson-Schwinger and Bethe-Salpeter equations. We explicitly check the support and polynomiality properties, and the behavior under charge conjugation or time invariance of our model. We derive analytic expressions for the pion Double Distributions and Generalized Parton Distribution at vanishing pion momentum transfer at a low scale. Our model compares very well to experimental pion form factor or parton distribution function data.

Gait parameter risk factors for falls under simple and dual task conditions in cognitively impaired older people.

PubMed

Taylor, Morag E; Delbaere, Kim; Mikolaizak, A Stefanie; Lord, Stephen R; Close, Jacqueline C T

2013-01-01

Impaired gait may contribute to the increased rate of falls in cognitively impaired older people. We investigated whether gait under simple and dual task conditions could predict falls in this group. The study sample consisted of 64 community dwelling older people with mild to moderate cognitive impairment. Participants walked at their preferred speed under three conditions: (a) simple walking, (b) walking while carrying a glass of water and (c) walking while counting backwards from 30. Spatiotemporal gait parameters were measured using the GAITRite(®) mat. Falls were recorded prospectively for 12months with the assistance of carers. Twenty-two (35%) people fell two or more times in the 12month follow-up period. There was a significant main effect of gait condition and a significant main effect of faller status for mean value measures (velocity, stride length, double support time and stride width) and for variability measures (swing time variability and stride length variability). Examination of individual gait parameters indicated that the multiple fallers walked more slowly, had shorter stride length, spent longer time in double support, had a wider support width and showed more variability in stride length and swing time (p<0.05). There was no significant interaction between gait condition and faller status for any of the gait variables. In conclusion, dual task activities adversely affect gait in cognitively impaired older people. Multiple fallers performed worse in each gait condition but the addition of a functional or cognitive secondary task provided no added benefit in discriminating fallers from non-fallers with cognitive impairment. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of cognitive challenge on the postural control of patients with ACL reconstruction under visual and surface perturbations.

PubMed

Lion, Alexis; Gette, Paul; Meyer, Christophe; Seil, Romain; Theisen, Daniel

2018-02-01

Our study aimed to evaluate the effect of cognitive challenge on double-leg postural control under visual and surface perturbations of patients with anterior cruciate ligament reconstruction (ACLR) cleared to return to sport. Double-leg stance postural control of 19 rehabilitated patients with ACLR (age: 24.8 ± 6.7 years, time since surgery: 9.2 ± 1.6 months) and 21 controls (age: 24.9 ± 3.7 years) was evaluated in eight randomized situations combining two cognitive (with and without silent backward counting in steps of seven), two visual (eyes open, eyes closed) and two surface (stable support, foam support) conditions. Sway area and sway path of the centre of foot pressure were measured during three 20-s recordings for each situation. Higher values indicated poorer postural control. Generally, postural control of patients with ACLR and controls was similar for sway area and sway path (p > 0.05). The lack of visual anchorage and the disturbance of the plantar input by the foam support increased sway area and sway path (p < 0.001) similarly in both groups. The addition of the cognitive task decreased sway area and sway path (p < 0.001) similarly in both groups. Patients with ACLR who recently completed their rehabilitation have normalized postural control during double-leg stance tests. The use of a dual task paradigm under increased task complexity modified postural control, but in a similar way in patients with ACLR than in healthy controls. Double-leg stance tests, even under challenging conditions, are not sensitive enough to reveal postural control differences between rehabilitated patients with ACLR and controls. Copyright © 2017 Elsevier B.V. All rights reserved.

A hippotherapy simulator is effective to shift weight bearing toward the affected side during gait in patients with stroke.

PubMed

Sung, Yun-Hee; Kim, Chang-Ju; Yu, Byong-Kyu; Kim, Kyeong-Mi

2013-01-01

We investigated whether a hippotherapy simulator has influence on symmetric body weight bearing during gait in patients with stroke. Stroke patients were divided into a control group (n = 10) that received conventional rehabilitation for 60 min/day, 5 times/week for 4 weeks and an experimental group (n = 10) that used a hippotherapy simulator for 15 min/day, 5 times/week for 4 weeks after conventional rehabilitation for 45 min/day. Temporospatial gait assessed using OptoGait and trunk muscles (abdominis and erector spinae on affected side) activity evaluated using surface electromyography during sit-to-stand and gait. Prior to starting the experiment, pre-testing was performed. At the end of the 4-week intervention, we performed post-testing. Activation of the erector spinae in the experimental group was significantly increased compared to that in the control group (p < 0.01), whereas activation of the rectus abdominis decreased during sit-to-stand. Of the gait parameters, load response, single support, total double support, and pre-swing showed significant changes in the experimental group with a hippotherapy simulator compared to control group (p < 0.05). Moreover, activation of the erector spinae and rectus abdominis in gait correlate with changes of gait parameters including load response, single support, total double support, and pre-swing in experimental group. These findings suggest that use of a hippotherapy simulator to patients with stroke can improve asymmetric weight bearing by influencing trunk muscles.

Effects of load carriage and footwear on lower extremity kinetics and kinematics during overground walking.

PubMed

Dames, Kevin D; Smith, Jeremy D

2016-10-01

Kinetic and kinematic responses during walking vary by footwear condition. Load carriage also influences gait patterns, but it is unclear how an external load influences barefoot walking. Twelve healthy adults (5 women, 7 men) with no known gait abnormalities participated in this study (age=23±3years, height=1.73±0.11m, and mass=70.90±12.67kg). Ground reaction forces and 3D motion were simultaneously collected during overground walking at 1.5ms -1 in four conditions: Barefoot Unloaded, Shod Unloaded, Barefoot Loaded, and Shod Loaded. Barefoot walking reduced knee and hip joint ranges of motion, as well as stride length, stance time, swing time, and double support time. Load carriage increased stance and double support times. The 15% body weight load increased GRFs ∼15%. Walking barefoot reduced peak anteroposterior GRFs but not peak vertical GRFs. Load carriage increased hip, knee, and ankle joint moments and powers, while walking barefoot increased knee and hip moments and powers. Thus, spatiotemporal and kinematic adjustments to walking barefoot decrease GRFs but increase knee and hip kinetic measures during overground walking. The ankle seems to be less affected by these footwear conditions. Regardless of footwear, loading requires larger GRFs, joint loads, and joint powers. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of SuperUlam on Supporting Concentration and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study.

PubMed

Udani, Jay K

2013-01-01

Background. SuperUlam is a proprietary blend of natural ingredients aimed at supporting brain health. We aimed to evaluate the effect of SuperUlam on attention and mood in healthy adults. Methods. Twenty healthy individuals aged 35-65 were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Study duration was 3 weeks and consisted of 3 visits. Measurement of cognitive function included computer-based testing of reaction time, complex attention, working memory, sustained attention, and executive functioning. Mood testing was performed via the profile of mood states (POMS) survey and the Chalder fatigue scale. Results. Cognitive function testing demonstrated a significant improvement from baseline in executive functioning, cognitive flexibility, reaction time, and working memory in the product group only (P < 0.05). When comparing the study product to placebo, the data demonstrated a significant decrease in tension, depression, and anger (P < 0.05). There was no significant difference between the product and placebo in the other measures of mood, including vigor, fatigue, confusion, and total mood disturbance. No adverse events were reported. Conclusions. Supplementation with SuperUlam is safe to consume with potential benefits to cognitive function and mood.

Effects of SuperUlam on Supporting Concentration and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

PubMed Central

Udani, Jay K

2013-01-01

Background. SuperUlam is a proprietary blend of natural ingredients aimed at supporting brain health. We aimed to evaluate the effect of SuperUlam on attention and mood in healthy adults. Methods. Twenty healthy individuals aged 35–65 were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Study duration was 3 weeks and consisted of 3 visits. Measurement of cognitive function included computer-based testing of reaction time, complex attention, working memory, sustained attention, and executive functioning. Mood testing was performed via the profile of mood states (POMS) survey and the Chalder fatigue scale. Results. Cognitive function testing demonstrated a significant improvement from baseline in executive functioning, cognitive flexibility, reaction time, and working memory in the product group only (P < 0.05). When comparing the study product to placebo, the data demonstrated a significant decrease in tension, depression, and anger (P < 0.05). There was no significant difference between the product and placebo in the other measures of mood, including vigor, fatigue, confusion, and total mood disturbance. No adverse events were reported. Conclusions. Supplementation with SuperUlam is safe to consume with potential benefits to cognitive function and mood. PMID:24371452

Observation of the Double Beta Decay of ^48Ca^*

NASA Astrophysics Data System (ADS)

Piepke, Andreas

1996-10-01

Neutrino-less double beta decay is at present the most sensitive kinematic test for finite neutrino mass. The unfolding of a neutrino mass (or a mass limit) from measured decay rates, however, relies on complicated nuclear structure calculations. In the absence of any rigorous test for these calculations the investigation of the very rare two-neutrino double beta decay (β β 2ν) decay serves to verify the validity of the nuclear models. Among all candidate nuclei the double beta decay ^48Caarrow ^48Ti is unique, since it is the only one which can be treated ``exactly'' in the nuclear shell model. Taking advantage of this special situation, isotopically enriched ^48Ca (enrichment 73% ), in form of finely powdered CaCO_3, was exposed in the Irvine time projection chamber located at the Hoover dam, 72 m below ground. The ongoing data analysis shows strong evidence for the presence of a β β 2ν signal i.e. a two electron spectrum with the expected endpoint of 4.3 MeV. The experimental half life appears to agree with most shell model calculations. A detailed discussion of the results will be presented.(Work in collaboration with A. Balysh, V.I. Lebedev, A. Pronsky, KIAE Moscow, A. De Silva, M.K. Moe, M.A. Nelson, M.A. Vient, UC Irvine and K. Lou, P. Vogel, Caltech.) ^* Supported by U.S. Department of Energy. A.P. acknowledges support of the Alexander von Humboldt Foundation.

Building of nested components by a double-nozzle droplet deposition process

NASA Astrophysics Data System (ADS)

Li, SuLi; Wei, ZhengYing; Du, Jun; Zhao, Guangxi; Wang, Xin; Lu, BingHeng

2016-07-01

According to the nested components jointed with multiple parts,a double-nozzle droplet deposition process was put forward in this paper, and the experimental system was developed. Through the research on the properties of support materials and the process of double-nozzle droplet deposition, the linkage control of the metal droplet deposition and the support material extrusion was realized, and a nested component with complex construction was fabricated directly. Compared with the traditional forming processes, this double-nozzle deposition process has the advantages of short cycle, low cost and so on. It can provide an approach way to build the nested parts.

Cost-effectiveness of possible future smoking cessation strategies in Hungary: results from the EQUIPTMOD.

PubMed

Németh, Bertalan; Józwiak-Hagymásy, Judit; Kovács, Gábor; Kovács, Attila; Demjén, Tibor; Huber, Manuel B; Cheung, Kei-Long; Coyle, Kathryn; Lester-George, Adam; Pokhrel, Subhash; Vokó, Zoltán

2018-01-25

To evaluate potential health and economic returns from implementing smoking cessation interventions in Hungary. The EQUIPTMOD, a Markov-based economic model, was used to assess the cost-effectiveness of three implementation scenarios: (a) introducing a social marketing campaign; (b) doubling the reach of existing group-based behavioural support therapies and proactive telephone support; and (c) a combination of the two scenarios. All three scenarios were compared with current practice. The scenarios were chosen as feasible options available for Hungary based on the outcome of interviews with local stakeholders. Life-time costs and quality-adjusted life years (QALYs) were calculated from a health-care perspective. The analyses used various return on investment (ROI) estimates, including incremental cost-effectiveness ratios (ICERs), to compare the scenarios. Probabilistic sensitivity analyses assessed the extent to which the estimated mean ICERs were sensitive to the model input values. Introducing a social marketing campaign resulted in an increase of 0.3014 additional quitters per 1 000 smokers, translating to health-care cost-savings of €0.6495 per smoker compared with current practice. When the value of QALY gains was considered, cost-savings increased to €14.1598 per smoker. Doubling the reach of existing group-based behavioural support therapies and proactive telephone support resulted in health-care savings of €0.2539 per smoker (€3.9620 with the value of QALY gains), compared with current practice. The respective figures for the combined scenario were €0.8960 and €18.0062. Results were sensitive to model input values. According to the EQUIPTMOD modelling tool, it would be cost-effective for the Hungarian authorities introduce a social marketing campaign and double the reach of existing group-based behavioural support therapies and proactive telephone support. Such policies would more than pay for themselves in the long term. © 2018 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

Wide variation of prostate-specific antigen doubling time of untreated, clinically localized, low-to-intermediate grade, prostate carcinoma.

PubMed

Choo, Richard; Klotz, Laurence; Deboer, Gerrit; Danjoux, Cyril; Morton, Gerard C

2004-08-01

To assess the prostate specific antigen (PSA) doubling time of untreated, clinically localized, low-to-intermediate grade prostate carcinoma. A prospective single-arm cohort study has been in progress since November 1995 to assess the feasibility of a watchful-observation protocol with selective delayed intervention for clinically localized, low-to-intermediate grade prostate adenocarcinoma. The PSA doubling time was estimated from a linear regression of ln(PSA) against time, assuming a simple exponential growth model. As of March 2003, 231 patients had at least 6 months of follow-up (median 45) and at least three PSA measurements (median 8, range 3-21). The distribution of the doubling time was: < 2 years, 26 patients; 2-5 years, 65; 5-10 years, 42; 10-20 years, 26; 20-50 years, 16; >50 years, 56. The median doubling time was 7.0 years; 42% of men had a doubling time of >10 years. The doubling time of untreated clinically localized, low-to-intermediate grade prostate cancer varies widely.

Measurement of efficiency in calculus removal with a frequency-doubled Alexandrite laser on pigs' jaws

NASA Astrophysics Data System (ADS)

Pilgrim, Christian G.; Rechmann, Peter; Goldin, Dan S.; Hennig, Thomas

2000-03-01

Periodontal therapy aims in a most sufficient cleaning of tooth surfaces from supra- and subgingival calculus. As a standard dental procedure teeth are treated with ultrasonic devices. The competence of the frequency doubled Alexandrite laser for a highly effective and selective removal of calculus has been repeatedly proved. Aim of the study presented here was to determine the efficiency at simulated clinical conditions of the frequency doubled Alexandrite laser (laboratory prototype, q-switched, fiber guided, wavelength 377 nm, pulse duration 1 microsecond, pulse repetition rate 70 Hz, water cooling) by quantifying it's calculus removing efficiency. The evaluated data were compared to those obtained with an ultrasonic calculus remover. In the first part of the study sample material consisted of 23 pigs' jaws. They were divided into two groups. The teeth of one group were cleaned on their buccal surfaces using an ultrasonic device (Sonosoft Lux, KaVo, Biberach, Germany; tip #9). Than hand-guided cleaning was performed until no further improvement in cleanness was visible. Cleaning time was measured. Photographic documentation was taken before and after the treatment. The teeth in the second group were cleaned engaging a frequency doubled Alexandrite laser. Treatment time was measured and photographs were taken in the same way. In the second part of the study 21 surfaces of human teeth set up in an artificial pocket model were treated with both systems again. Measurements followed the same protocol. The results strongly support the use of the frequency doubled Alexandrite laser for calculus removal.

LENS (lithography enhancement toward nano scale): a European project to support double exposure and double patterning technology development

NASA Astrophysics Data System (ADS)

Cantu, Pietro; Baldi, Livio; Piacentini, Paolo; Sytsma, Joost; Le Gratiet, Bertrand; Gaugiran, Stéphanie; Wong, Patrick; Miyashita, Hiroyuki; Atzei, Luisa R.; Buch, Xavier; Verkleij, Dick; Toublan, Olivier; Perez-Murano, Francesco; Mecerreyes, David

2010-04-01

In 2009 a new European initiative on Double Patterning and Double Exposure lithography process development was started in the framework of the ENIAC Joint Undertaking. The project, named LENS (Lithography Enhancement Towards Nano Scale), involves twelve companies from five different European Countries (Italy, Netherlands, France, Belgium Spain; includes: IC makers (Numonyx and STMicroelectronics), a group of equipment and materials companies (ASML, Lam Research srl, JSR, FEI), a mask maker (Dai Nippon Photomask Europe), an EDA company (Mentor Graphics) and four research and development institutes (CEA-Leti, IMEC, Centro Nacional de Microelectrónica, CIDETEC). The LENS project aims to develop and integrate the overall infrastructure required to reach patterning resolutions required by 32nm and 22nm technology nodes through the double patterning and pitch doubling technologies on existing conventional immersion exposure tools, with the purpose to allow the timely development of 32nm and 22nm technology nodes for memories and logic devices, providing a safe alternative to EUV, Higher Refraction Index Fluids Immersion Lithography and maskless lithography, which appear to be still far from maturity. The project will cover the whole lithography supply chain including design, masks, materials, exposure tools, process integration, metrology and its final objective is the demonstration of 22nm node patterning on available 1.35 NA immersion tools on high complexity mask set.

Unique characteristics of motor adaptation during walking in young children.

PubMed

Musselman, Kristin E; Patrick, Susan K; Vasudevan, Erin V L; Bastian, Amy J; Yang, Jaynie F

2011-05-01

Children show precocious ability in the learning of languages; is this the case with motor learning? We used split-belt walking to probe motor adaptation (a form of motor learning) in children. Data from 27 children (ages 8-36 mo) were compared with those from 10 adults. Children walked with the treadmill belts at the same speed (tied belt), followed by walking with the belts moving at different speeds (split belt) for 8-10 min, followed again by tied-belt walking (postsplit). Initial asymmetries in temporal coordination (i.e., double support time) induced by split-belt walking were slowly reduced, with most children showing an aftereffect (i.e., asymmetry in the opposite direction to the initial) in the early postsplit period, indicative of learning. In contrast, asymmetries in spatial coordination (i.e., center of oscillation) persisted during split-belt walking and no aftereffect was seen. Step length, a measure of both spatial and temporal coordination, showed intermediate effects. The time course of learning in double support and step length was slower in children than in adults. Moreover, there was a significant negative correlation between the size of the initial asymmetry during early split-belt walking (called error) and the aftereffect for step length. Hence, children may have more difficulty learning when the errors are large. The findings further suggest that the mechanisms controlling temporal and spatial adaptation are different and mature at different times.

Dynamics of vacuum-sealed, double-leaf partitions

NASA Astrophysics Data System (ADS)

Kavanaugh, Joshua Stephen

The goal of this research is to investigate the feasibility and potential effectiveness of using vacuum-sealed, double-leaf partitions for applications in noise control. Substantial work has been done previously on double-leaf partitions where the acoustics of the inner chamber and mechanical vibrations of structural supports are passively and actively controlled. The work presented here is unique in that the proposed system aims to eliminate the need for active acoustic control of transmitted acoustic energy by removing all the air between the two panels of the double partition. Therefore, the only remaining energy paths would be along the boundary and at the points where there are intermediate structural supports connecting the two panels. The eventual goal of the research is to develop a high-loss double-leaf partition that simplifies active control by removing the need for control of the air cavity and channeling all the energy into discrete structural paths. The work presented here is a first step towards the goal of designing a high-loss, actively-controlled double-leaf partition with an air-evacuated inner chamber. One experiment is conducted to investigate the effects of various levels of vacuum on the response of a double-leaf partition whose panels are mechanically coupled only at the boundary. Another experiment is conducted which investigates the effect of changing the stiffness of an intermediate support coupling the two panels of a double-leaf partition in which a vacuum has been applied to the inner cavity. The available equipment was able to maintain a 99% vacuum between the panels. Both experiments are accompanied by analytical models used to investigate the importance of various dynamic parameters. Results show that the vacuum-sealed system shows some potential for increased transmission loss, primarily by the changing the natural frequencies of the double-leaf partition.

Kinematic Analysis Quantifies Gait Abnormalities Associated with Lameness in Broiler Chickens and Identifies Evolutionary Gait Differences

PubMed Central

Caplen, Gina; Hothersall, Becky; Murrell, Joanna C.; Nicol, Christine J.; Waterman-Pearson, Avril E.; Weeks, Claire A.; Colborne, G. Robert

2012-01-01

This is the first time that gait characteristics of broiler (meat) chickens have been compared with their progenitor, jungle fowl, and the first kinematic study to report a link between broiler gait parameters and defined lameness scores. A commercial motion-capturing system recorded three-dimensional temporospatial information during walking. The hypothesis was that the gait characteristics of non-lame broilers (n = 10) would be intermediate to those of lame broilers (n = 12) and jungle fowl (n = 10, tested at two ages: immature and adult). Data analysed using multi-level models, to define an extensive range of baseline gait parameters, revealed inter-group similarities and differences. Natural selection is likely to have made jungle fowl walking gait highly efficient. Modern broiler chickens possess an unbalanced body conformation due to intense genetic selection for additional breast muscle (pectoral hypertrophy) and whole body mass. Together with rapid growth, this promotes compensatory gait adaptations to minimise energy expenditure and triggers high lameness prevalence within commercial flocks; lameness creating further disruption to the gait cycle and being an important welfare issue. Clear differences were observed between the two lines (short stance phase, little double-support, low leg lift, and little back displacement in adult jungle fowl; much double-support, high leg lift, and substantial vertical back movement in sound broilers) presumably related to mass and body conformation. Similarities included stride length and duration. Additional modifications were also identified in lame broilers (short stride length and duration, substantial lateral back movement, reduced velocity) presumably linked to musculo-skeletal abnormalities. Reduced walking velocity suggests an attempt to minimise skeletal stress and/or discomfort, while a shorter stride length and time, together with longer stance and double-support phases, are associated with instability. We envisage a key future role for this highly quantitative methodology in pain assessment (associated with broiler lameness) including experimental examination of therapeutic agent efficacy. PMID:22815823

Gait and Functional Mobility Deficits in Fragile X-Associated Tremor/Ataxia Syndrome.

PubMed

O'Keefe, Joan A; Robertson-Dick, Erin E; Hall, Deborah A; Berry-Kravis, Elizabeth

2016-08-01

Fragile X-associated tremor/ataxia syndrome (FXTAS) results from a "premutation" (PM) size CGG repeat expansion in the fragile X mental retardation 1 (FMR1) gene. Cerebellar gait ataxia is the primary feature in some FXTAS patients causing progressive disability. However, no studies have quantitatively characterized gait and mobility deficits in FXTAS. We performed quantitative gait and mobility analysis in seven FMR1 PM carriers with FXTAS and ataxia, six PM carriers without FXTAS, and 18 age-matched controls. We studied four independent gait domains, trunk range of motion (ROM), and movement transitions using an instrumented Timed Up and Go (i-TUG). We correlated these outcome measures with FMR1 molecular variables and clinical severity scales. PM carriers with FXTAS were globally impaired in every gait performance domain except trunk ROM compared to controls. These included total i-TUG duration, stride velocity, gait cycle time, cadence, double-limb support and swing phase times, turn duration, step time before turn, and turn-to-sit duration, and increased gait variability on several measures. Carriers without FXTAS did not differ from controls on any parameters, but double-limb support time was close to significance. Balance and disability scales correlated with multiple gait and movement transition parameters, while the FXTAS Rating Scale did not. This is the first study to quantitatively examine gait and movement transitions in FXTAS patients. Gait characteristics were consistent with those from previous cohorts with cerebellar ataxia. Sensitive measures like the i-TUG may help determine efficacy of interventions, characterize disease progression, and provide early markers of disease in FXTAS.

Topological view of quantum tunneling coherent destruction

NASA Astrophysics Data System (ADS)

Bernardini, Alex E.; Chinaglia, Mariana

2017-08-01

Quantum tunneling of the ground and first excited states in a quantum superposition driven by a novel analytical configuration of a double-well (DW) potential is investigated. Symmetric and asymmetric potentials are considered as to support quantum mechanical zero mode and first excited state analytical solutions. Reporting about a symmetry breaking that supports the quantum conversion of a zero-mode stable vacuum into an unstable tachyonic quantum state, two inequivalent topological scenarios are supposed to drive stable tunneling and coherent tunneling destruction respectively. A complete prospect of the Wigner function dynamics, vector field fluxes and the time dependence of stagnation points is obtained for the analytical potentials that support stable and tachyonic modes.

Assessment of gait in subcortical vascular encephalopathy by computerized analysis: a cross-sectional and longitudinal study.

PubMed

Bäzner, H; Oster, M; Daffertshofer, M; Hennerici, M

2000-11-01

In subcortical vascular encephalopathy (SVE) gait disturbance is a common and early clinical sign which might be used to monitor disease progression. In the absence of reliable scales and with regard to the equivocal results of highly complex gait imaging devices we assessed the natural course of SVE in a prospective study, using a new straight forward technique to quantify and compare sequential gait studies. We report the results of 300 computerized gait analyses in 119 patients with SVE and 63 age-matched controls. Thirty-nine SVE patients were re-evaluated to monitor the natural course of the disease and to study the correlation of gait disturbances with MRI changes and neuropsychological findings. The system consists of a set of shoes containing 16 load sensors and a measuring-unit reading each sensor at 20-ms intervals. By off-line analysis we graded each recording on a Gait Disorder Score (GDS) with six variables indicating gait steadiness: step frequency, length of gait lines (which represent the movement of the centre of gravity during heel to toe movement), length of single support lines, variability of single and of double support lines, and double support time. In cross-sectional analysis, patients with SVE showed cadence (steps/min) to be reduced at 87.3 +/- 19.5 (96.4 +/- 7.8 in controls, P < 0.05). Length of gait lines was significantly less: 0.70 +/- 0.13 vs. 0.80 +/- 0.05 in controls, with length of single support gait lines reduced at 0.42 +/- 0.14 in SVE (0.58 +/- 0.06 in controls, P < 0.05). Variability of both single support lines (5.69 +/- 1.90%; 4.24 +/- 1.07% in controls, P < 0.05) and double support lines was elevated (3.59 +/- 1.62% vs. 2.54 +/- 0.59%), while duration of double support phases was increased (0.19 +/- 0.10 s vs. 0.13 +/- 0.02 s in controls, P < 0.05). The progressive character of the disease was demonstrated by increasing GDS values in 39 SVE patients with a frontal gait disorder who were re-investigated after a mean interval of 26 months (5.4 +/- 4.5 vs. 8.4 +/- 5.5, P < 0.05). This study shows the value of a new and practicable gait analysis system for the evaluation of gait disorders and it quantifies the deterioration of gait in SVE patients.

Predicting chaos for infinite dimensional dynamical systems: The Kuramoto-Sivashinsky equation, a case study

NASA Technical Reports Server (NTRS)

Smyrlis, Yiorgos S.; Papageorgiou, Demetrios T.

1991-01-01

The results of extensive computations are presented in order to accurately characterize transitions to chaos for the Kuramoto-Sivashinsky equation. In particular, the oscillatory dynamics in a window that supports a complete sequence of period doubling bifurcations preceding chaos is followed. As many as thirteen period doublings are followed and used to compute the Feigenbaum number for the cascade and so enable, for the first time, an accurate numerical evaluation of the theory of universal behavior of nonlinear systems, for an infinite dimensional dynamical system. Furthermore, the dynamics at the threshold of chaos exhibit a fractal behavior which is demonstrated and used to compute a universal scaling factor that enables the self-similar continuation of the solution into a chaotic regime.

Characterization of geostationary particle signatures based on the 'injection boundary' model

NASA Technical Reports Server (NTRS)

Mauk, B. H.; Meng, C.-I.

1983-01-01

A simplified analytical procedure is used to characterize the details of geostationary particle signatures, in order to lend support to the 'injection boundary' concept. The signatures are generated by the time-of-flight effects evolving from an initial sharply defined, double spiraled boundary configuration. Complex and highly variable dispersion patterns often observed by geostationary satellites are successfully reproduced through the exclusive use of the most fundamental convection configuration characteristics. Many of the details of the patterns have not been previously presented. It is concluded that most of the dynamical dispersion features can be mapped to the double spiral boundary without further ad hoc assumptions, and that predicted and observed dispersion patterns exhibit symmetries distinct from those associated with the quasi-stationary particle convection patterns.

Zygomatic Implants: The Impact of Zygoma Bone Support on Biomechanics.

PubMed

Romeed, Shihab; Malik, Raheel; Dunne, Stephen

2012-03-20

Abstract Maxillectomy and severely resorbed maxilla are challenging to restore with provision of removable prostheses. Dental implants are essential to restore aesthetics and function and subsequently quality of life in such group of patients. Zygomatic implants reduce the complications associated with bone grafting procedures and simplify the rehabilitation of atrophic maxilla and maxillectomy. The purpose of this study was to compare, by means of three-dimensional finite element analysis, the impact of different zygomatic bone support (10, 15, and 20mm) on the biomechanics of zygomatic implants. Results indicated maximum stresses within the fixture were increased by three times, when bone support decreased from 20 to 10mm, and concentrated at fixture/bone interface. However, stresses within the abutment screw and abutment itself were not significantly different regardless of the bone support level. Supporting bone at 10mm suffered double the stresses of 15 and 20mm. Fixture's deflection was decreased by two to three times when bone level support increased to 15mm and 20mm respectively. It was concluded that zygomatic bone support should not be less than 15mm and abutment screw is not at risk of fracture regardless of the zygomatic bone support.

Zygomatic implants: the impact of zygoma bone support on biomechanics.

PubMed

Romeed, Shihab A; Malik, Raheel; Dunne, Stephen M

2014-06-01

Maxillectomy and severely resorbed maxilla are challenging to restore with provision of removable prostheses. Dental implants are essential to restore esthetics and function and subsequently quality of life in such group of patients. Zygomatic implants reduce the complications associated with bone grafting procedures and simplify the rehabilitation of atrophic maxilla and maxillectomy. The purpose of this study was to compare, by means of 3-dimensional finite element analysis, the impact of different zygomatic bone support (10, 15, and 20 mm) on the biomechanics of zygomatic implants. Results indicated that maximum stresses within the fixture were increased by 3 times when bone support decreased from 20 to 10 mm and were concentrated at the fixture/bone interface. However, stresses within the abutment screw and the abutment itself were not significantly different regardless of the bone support level. Supporting bone at 10 mm sustained double the stresses of 15 and 20 mm. Fixture's deflection was decreased by 2 to 3 times when bone support level increased to 15 mm and 20 mm, respectively. It was concluded that zygomatic bone support should not be less than 15 mm, and abutment screw is not at risk of fracture regardless of the zygomatic bone support.

Sub-Surface Windscreen for Outdoor Measurement of Infrasound

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J. (Inventor); Shams, Qamar A. (Inventor)

2014-01-01

A windscreen is configured for measuring outdoor infrasonic sound. The windscreen includes a container and a microphone. The container defines a chamber. The microphone is disposed in the chamber and can be operatively supported by the floor. The microphone is configured for detecting infrasonic sound. The container is advantageously formed from material that exhibits an acoustic impedance of between 0 and approximately 3150 times the acoustic impedance of air. A reflector plate may be disposed in the container. The reflector plate operatively can support the microphone and provides a doubling effect of infrasonic pressure at the microphone.

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT SEISMIC ANALYSIS IN SUPPORT OF INCREASED LIQUID LEVEL IN 241-AP TANK FARMS

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

MACKEY TC; ABBOTT FG; CARPENTER BG

2007-02-16

The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the DST System at Hanford. The "Double-Shell Tank (DST) Integrity Project - DST Thermal and Seismic Project" is in support of Tri-Party Agreement Milestone M-48-14.

Pilot-in-the Loop CFD Method Development

DTIC Science & Technology

2016-10-20

State University. All software supporting piloted simulations must run at real time speeds or faster. This requirement drives the number of...objects in the environment. In turn, this flowfield affects the local aerodynamics of the main rotor blade sections, affecting blade air loads, and...model, empirical models of ground effect and rotor / airframe interactions) are disabled when running in fully coupled mode, so as to not “double count

Coupled Hydrodynamic Instability Growth on Oblique Interfaces with a Reflected Rarefaction

NASA Astrophysics Data System (ADS)

Rasmus, A. M.; Flippo, K. A.; di Stefano, C. A.; Doss, F. W.; Hager, J. D.; Merritt, E. C.; Cardenas, T.; Schmidt, D. W.; Kline, J. L.; Kuranz, C. C.

2017-10-01

Hydrodynamic instabilities play an important role in the evolution of inertial confinement fusion and astrophysical phenomena. Three of the Omega-EP long pulse beams (10 ns square pulse, 14 kJ total energy, 1.1 mm spot size) drive a supported shock across a heavy-to-light, oblique, interface. Single- and double-mode initial conditions seed coupled Richtmyer-Meshkov (RM), Rayleigh-Taylor (RT), and Kelvin-Helmholtz (KH) growth. At early times, growth is dominated by RM and KH, whereas at late times a rarefaction from laser turn-off reaches the interface, leading to decompression and RT growth. The addition of a thirty degree tilt does not alter mix width to within experimental error bars, even while significantly altering spike and bubble morphology. The results of single and double-mode experiments along with simulations using the multi-physics hydro-code RAGE will be presented. This work performed under the auspices of the U.S. Department of Energy by LANL under contract DE-AC52-06NA25396. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956. This material is partially supported by DOE Office of Science Graduate Student Research (SCGSR) program.

Analytical and experimental investigation on transmission loss of clamped double panels: implication of boundary effects.

PubMed

Xin, F X; Lu, T J

2009-03-01

The air-borne sound insulation performance of a rectangular double-panel partition clamp mounted on an infinite acoustic rigid baffle is investigated both analytically and experimentally and compared with that of a simply supported one. With the clamped (or simply supported) boundary accounted for by using the method of modal function, a double series solution for the sound transmission loss (STL) of the structure is obtained by employing the weighted residual (Galerkin) method. Experimental measurements with Al double-panel partitions having air cavity are subsequently carried out to validate the theoretical model for both types of the boundary condition, and good overall agreement is achieved. A consistency check of the two different models (based separately on clamped modal function and simply supported modal function) is performed by extending the panel dimensions to infinite where no boundaries exist. The significant discrepancies between the two different boundary conditions are demonstrated in terms of the STL versus frequency plots as well as the panel deflection mode shapes.

The effect of three different types of walking aids on spatio-temporal gait parameters in community-dwelling older adults.

PubMed

Härdi, Irene; Bridenbaugh, Stephanie A; Gschwind, Yves J; Kressig, Reto W

2014-04-01

Gait and balance impairments lead to falls and injuries in older people. Walking aids are meant to increase gait safety and prevent falls, yet little is known about how their use alters gait parameters. This study aimed to quantify gait in older adults during walking without and with different walking aids and to compare gait parameters to matched controls. This retrospective study included 65 older (≥60 years) community dwellers who used a cane, crutch or walker and 195 independently mobile-matched controls. Spatio-temporal gait parameters were measured with an electronic walkway system during normal walking. When walking unaided or aided, walking aid users had significantly worse gait than matched controls. Significant differences between the walking aid groups were found for stride time variability (cane vs. walker) in walking unaided only. Gait performances significantly improved when assessed with vs. without the walking aid for the cane (increased stride time and length, decreased cadence and stride length variability), crutch (increased stride time and length, decreased cadence, stride length variability and double support) and walker (increased gait speed and stride length, decreased base of support and double support) users. Gait in older adults who use a walking aid is more irregular and unstable than gait in independently mobile older adults. Walking aid users have better gait when using their walking aid than when walking without it. The changes in gait were different for the different types of walking aids used. These study results may help better understand gait in older adults and differentiate between pathological gait changes and compensatory gait changes due to the use of a walking aid.

Ratios of double to single ionization of He and Ne by strong 400-nm laser pulses using the quantitative rescattering theory

NASA Astrophysics Data System (ADS)

Chen, Zhangjin; Li, Xiaojin; Zatsarinny, Oleg; Bartschat, Klaus; Lin, C. D.

2018-01-01

We present numerical simulations of the ratio between double and single ionization of He and Ne by intense laser pulses at wavelengths of 390 and 400 nm, respectively. The yields of doubly charged ions due to nonsequential double ionization (NSDI) are obtained by employing the quantitative rescattering (QRS) model. In this model, the NSDI ionization probability is expressed as a product of the returning electron wave packet (RWP) and the total scattering cross sections for laser-free electron impact excitation and electron impact ionization of the parent ion. According to the QRS theory, the same RWP is also responsible for the emission of high-energy above-threshold ionization photoelectrons. To obtain absolute double-ionization yields, the RWP is generated by solving the time-dependent Schrödinger equation (TDSE) within a one-electron model. The same TDSE results can also be taken to obtain single-ionization yields. By using the TDSE results to calibrate single ionization and the RWP obtained from the strong-field approximation, we further simplify the calculation such that the nonuniform laser intensity distribution in the focused laser beam can be accounted for. In addition, laser-free electron impact excitation and ionization cross sections are calculated using the state-of-the-art many-electron R -matrix theory. The simulation results for double-to-single-ionization ratios are found to compare well with experimental data and support the validity of the nonsequential double-ionization mechanism for the covered intensity region.

The Double ABCX Model of Family Stress and Adaptation: An Empirical Test by Analysis of Structural Equations with Latent Variables.

ERIC Educational Resources Information Center

Lavee, Yoav; And Others

1985-01-01

Examined relationships among major variables of the Double ABCX model of family stress and adaptation using data on Army families' adaptation to the crisis of relocation overseas. Results support the notion of pile-up of demands. Family system resources and social support are both found to facilitate adaptation. (Author/BL)

What is Swanson's Law & why Should you Care?

NASA Astrophysics Data System (ADS)

Hansen, S. F.; Partain, L.; Hansen, R. T.

2015-12-01

For 40 years the cost of Solar Photovoltaics (PV) has decreased by a factor of 2 for every 10X increase in its cumulative-installed electric-generating capacity (CC). The straight line, log-log, experimental and historical data fit of cost versus CC is called Swanson's Law for its accurate fit of the rapid decrease in cost over 6 orders of magnitude increase in CC with time. Now Solar PV is cost competitive with coal and natural gas in some regions and provides 1% of the world's electric generating capacity. The Law can next be tested to predict the future. With 2 more orders of magnitude increase in CC, Solar PV could provide 10% and then 100% of the world's current electric capacity, as the Law projects costs falling by another factor of 4. For the last 10 years CC has doubled every 2 years under strong public policy support. If this doubling and policy support are extended, an order-of-magnitude increase (10X) will occur every 6.6 yrs and installed solar PV capacity could reach 100% of the current world's consumption in 13 years or by 2028. The world's solar resource, accessible indefinitely and yearly to PV, is over 1000 times current consumption while coal, uranium, petroleum and natural gas are finite, limited resources, destined to be depleted within our lifetimes or the lives of our children or grandchildren. In 2015 a 56 MW fossil fueled power plant was shut down at Stanford University and replaced with Solar PV and geothermal to save money and eliminate greenhouse gas emissions. If more such shut downs could follow this same 2 year doubling time as Solar PV, then the replacements could exceed 14,000 within 26 years or by 2041, including all 7000 current coal-fired plants plus an equivalent number fueled by uranium, petroleum and natural gas. These shut-downs, including all current fossil-fueled-power plants, could start reversing the human-generated, greenhouse-gas-induced, global climate changes by 2041.

Development of a double-layered ceramic filter for aerosol filtration at high-temperatures: the filter collection efficiency.

PubMed

de Freitas, Normanda L; Gonçalves, José A S; Innocentini, Murilo D M; Coury, José R

2006-08-25

The performance of double-layered ceramic filters for aerosol filtration at high temperatures was evaluated in this work. The filtering structure was composed of two layers: a thin granular membrane deposited on a reticulate ceramic support of high porosity. The goal was to minimize the high pressure drop inherent of granular structures, without decreasing their high collection efficiency for small particles. The reticulate support was developed using the technique of ceramic replication of polyurethane foam substrates of 45 and 75 pores per inch (ppi). The filtering membrane was prepared by depositing a thin layer of granular alumina-clay paste on one face of the support. Filters had their permeability and fractional collection efficiency analyzed for filtration of an airborne suspension of phosphatic rock in temperatures ranging from ambient to 700 degrees C. Results revealed that collection efficiency decreased with gas temperature and was enhanced with filtration time. Also, the support layer influenced the collection efficiency: the 75 ppi support was more effective than the 45 ppi. Particle collection efficiency dropped considerably for particles below 2 microm in diameter. The maximum collection occurred for particle diameters of approximately 3 microm, and decreased again for diameters between 4 and 8 microm. Such trend was successfully represented by the proposed correlation, which is based on the classical mechanisms acting on particle collection. Inertial impaction seems to be the predominant collection mechanism, with particle bouncing/re-entrainment acting as detachment mechanisms.

How to measure separations and angles between intra-molecular fluorescent markers

NASA Astrophysics Data System (ADS)

Flyvbjerg, Henrik; Mortensen, Kim I.; Sung, Jongmin; Spudich, James A.

We demonstrate a novel, yet simple tool for the study of structure and function of biomolecules by extending two-colour co-localization microscopy to fluorescent molecules with fixed orientations and in intra-molecular proximity. From each color-separated microscope image in a time-lapse movie and using only simple means, we simultaneously determine both the relative (x,y)-separation of the fluorophores and their individual orientations in space with accuracy and precision. The positions and orientations of two domains of the same molecule are thus time-resolved. Using short double-stranded DNA molecules internally labelled with two fixed fluorophores, we demonstrate the accuracy and precision of our method using the known structure of double-stranded DNA as a benchmark, resolve 10-base-pair differences in fluorophore separations, and determine the unique 3D orientation of each DNA molecule, thereby establishing short, double-labelled DNA molecules as probes of 3D orientation of anything to which one can attach them firmly. This work was supported by a Lundbeck fellowship to K.I.M; a Stanford Bio-X fellowship to J.S. and Grants from the NIH (GM33289) to J.A.S. and the Human Frontier Science Program (GP0054/2009-C) to J.A.S. and H.F.

A Study of Applying Pulsed Remote Field Eddy Current in Ferromagnetic Pipes Testing

PubMed Central

Luo, Qingwang; Shi, Yibing; Wang, Zhigang; Zhang, Wei; Li, Yanjun

2017-01-01

Pulsed Remote Field Eddy Current Testing (PRFECT) attracts the attention in the testing of ferromagnetic pipes because of its continuous spectrum. This paper simulated the practical PRFECT of pipes by using ANSYS software and employed Least Squares Support Vector Regression (LSSVR) to extract the zero-crossing time to analyze the pipe thickness. As a result, a secondary peak is found in zero-crossing time when transmitter passed by a defect. The secondary peak will lead to wrong quantification and the localization of defects, especially when defects are found only at the transmitter location. Aiming to eliminate the secondary peaks, double sensing coils are set in the transition zone and Wiener deconvolution filter is applied. In the proposed method, position dependent response of the differential signals from the double sensing coils is calibrated by employing zero-mean normalization. The methods proposed in this paper are validated by analyzing the simulation signals and can improve the practicality of PRFECT of ferromagnetic pipes. PMID:28475141

A Study of Applying Pulsed Remote Field Eddy Current in Ferromagnetic Pipes Testing.

PubMed

Luo, Qingwang; Shi, Yibing; Wang, Zhigang; Zhang, Wei; Li, Yanjun

2017-05-05

Pulsed Remote Field Eddy Current Testing (PRFECT) attracts the attention in the testing of ferromagnetic pipes because of its continuous spectrum. This paper simulated the practical PRFECT of pipes by using ANSYS software and employed Least Squares Support Vector Regression (LSSVR) to extract the zero-crossing time to analyze the pipe thickness. As a result, a secondary peak is found in zero-crossing time when transmitter passed by a defect. The secondary peak will lead to wrong quantification and the localization of defects, especially when defects are found only at the transmitter location. Aiming to eliminate the secondary peaks, double sensing coils are set in the transition zone and Wiener deconvolution filter is applied. In the proposed method, position dependent response of the differential signals from the double sensing coils is calibrated by employing zero-mean normalization. The methods proposed in this paper are validated by analyzing the simulation signals and can improve the practicality of PRFECT of ferromagnetic pipes.

Exploring the contributions of the supplementary eye field to subliminal inhibition using double-pulse transcranial magnetic stimulation.

PubMed

Chiau, Hui-Yan; Muggleton, Neil G; Juan, Chi-Hung

2017-01-01

It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Discussing mental illness in Chinese social media: the impact of influential sources on stigmatization and support among their followers.

PubMed

Wang, Weirui; Liu, Yu

2016-01-01

A content analysis was conducted to examine depression-related discourses by public opinion leaders and mainstream media in the Chinese social media platform Sina Weibo, as well as the impact of these discourses on their followers. The study revealed that stereotypical presentations of people with depression by influential sources often promoted stigmatization of or reduced support for depressed individuals among their followers. Environmental and genetic attributions for the disease in the original posts reduced stigmatization in the response posts. Information about recovery and treatment proved to be a double-edged sword, reducing stigmatization and support among followers at the same time. The use of a crime context to discuss depression in the original posts often promoted stigmatization, while discussing it in a health context increased support in the response posts.

Student Scientific Research within Communities-of-Practice (Abstract)

NASA Astrophysics Data System (ADS)

Genet, R.; Armstrong, J.; Blanko, P.; Boyce, G. B. P.; Brewer, M.; Buchheim, R.; Calanog, J.; Castaneda, D.; Chamberlin, R.; Clark, R. K.; Collins, D.; Conti, D.; Cormier, S.; FItzgerald, M.; Estrada, C.; Estrada, R.; Freed, R.; Gomez, E.; Hardersen, P.; Harshaw, R.; Johnson, J.; Kafka, S.; Kenney, J.; Monanan, K.; Ridgely, J.; Rowe, D.; Silliman, M.; Stojimirovic, I.; Tock, K.; Walker, D.

2017-12-01

(Abstract only) Social learning theory suggests that students who wish to become scientists will benefit by being active researchers early in their educational careers. As coauthors of published research, they identify themselves as scientists. This provides them with the inspiration, motivation, and staying power that many will need to complete the long educational process. This hypothesis was put to the test over the past decade by a one-semester astronomy research seminar where teams of students managed their own research. Well over a hundred published papers coauthored by high school and undergraduate students at a handful of schools substantiated this hypothesis. However, one could argue that this was a special case. Astronomy, after all, is supported by a large professional-amateur community-of-practice. Furthermore, the specific area of research - double star astrometry - was chosen because the observations could be quickly made, the data reduction and analysis was straight forward, and publication of the research was welcomed by the Journal of Double Star Observations. A recently initiated seminar development and expansion program - supported in part by the National Science Foundation - is testing a more general hypothesis that: (1) the seminar can be successfully adopted by many other schools; (2) research within astronomy can be extended from double star astrometry to time series photometry of variable stars, exoplanet transits, and asteroids; and (3) the seminar model can be extended to a science beyond astronomy: environmental science' specifically atmospheric science. If the more general hypothesis is also supported, seminars that similarly feature published high school and undergraduate student team research could have the potential to significantly improve science education by increasing the percentage of students who complete the education required to become professional scientists.

The relationship between brain volume and walking outcomes in older adults with and without diabetic peripheral neuropathy.

PubMed

Manor, Brad; Newton, Elizabeth; Abduljalil, Amir; Novak, Vera

2012-09-01

Diabetic peripheral neuropathy (DPN) alters walking. Yet, the compensatory role of central locomotor circuits remains unclear. We hypothesized that walking outcomes would be more closely related to regional gray matter volumes in older adults with DPN as compared with nonneuropathic diabetic patients and nondiabetic control subjects. Clinically important outcomes of walking (i.e., speed, stride duration variability, and double support time) were measured in 29 patients with DPN (type 2 diabetes with foot-sole somatosensory impairment), 68 diabetic (DM) patients (type 2 diabetes with intact foot-sole sensation), and 89 control subjects. Global and regional gray matter volumes were calculated from 3 Tesla magnetic resonance imaging. DPN subjects walked more slowly (P = 0.005) with greater stride duration variability (P < 0.001) and longer double support (P < 0.001) as compared with DM and control subjects. Diabetes was associated with less cerebellar gray matter volume (P < 0.001), but global gray matter volume was similar between groups. DPN subjects with lower gray matter volume globally (P < 0.004) and regionally (i.e., cerebellum, right-hemisphere dorsolateral prefrontal cortex, basal ganglia, P < 0.005) walked more slowly with greater stride duration variability and/or longer double support. Each relationship was stronger in DPN than DM subjects. In control subjects, brain volumes did not relate to walking patterns. Strong relationships between brain volumes and walking outcomes were observed in the DPN group and to a lesser extent the DM group, but not in control subjects. Individuals with DPN may be more dependent upon supraspinal elements of the motor control system to regulate several walking outcomes linked to poor health in elderly adults.

The Relationship Between Brain Volume and Walking Outcomes in Older Adults With and Without Diabetic Peripheral Neuropathy

PubMed Central

Manor, Brad; Newton, Elizabeth; Abduljalil, Amir; Novak, Vera

2012-01-01

OBJECTIVE Diabetic peripheral neuropathy (DPN) alters walking. Yet, the compensatory role of central locomotor circuits remains unclear. We hypothesized that walking outcomes would be more closely related to regional gray matter volumes in older adults with DPN as compared with nonneuropathic diabetic patients and nondiabetic control subjects. RESEARCH DESIGN AND METHODS Clinically important outcomes of walking (i.e., speed, stride duration variability, and double support time) were measured in 29 patients with DPN (type 2 diabetes with foot-sole somatosensory impairment), 68 diabetic (DM) patients (type 2 diabetes with intact foot-sole sensation), and 89 control subjects. Global and regional gray matter volumes were calculated from 3 Tesla magnetic resonance imaging. RESULTS DPN subjects walked more slowly (P = 0.005) with greater stride duration variability (P < 0.001) and longer double support (P < 0.001) as compared with DM and control subjects. Diabetes was associated with less cerebellar gray matter volume (P < 0.001), but global gray matter volume was similar between groups. DPN subjects with lower gray matter volume globally (P < 0.004) and regionally (i.e., cerebellum, right-hemisphere dorsolateral prefrontal cortex, basal ganglia, P < 0.005) walked more slowly with greater stride duration variability and/or longer double support. Each relationship was stronger in DPN than DM subjects. In control subjects, brain volumes did not relate to walking patterns. CONCLUSIONS Strong relationships between brain volumes and walking outcomes were observed in the DPN group and to a lesser extent the DM group, but not in control subjects. Individuals with DPN may be more dependent upon supraspinal elements of the motor control system to regulate several walking outcomes linked to poor health in elderly adults. PMID:22665216

Student Scientific Research within Communities-of-Practice

NASA Astrophysics Data System (ADS)

Genet, Russell; Armstrong, James; Blanko, Philip; Boyce, Grady Boyce, Pat; Brewer, Mark; Buchheim, Robert; Calanog, Jae; Castaneda, Diana; Chamberlin, Rebecca; Clark, R. Kent; Collins, Dwight; Conti, Dennis Cormier, Sebastien; Fitzgerald, Michael; Estrada, Chris; Estrada, Reed; Freed, Rachel Gomez, Edward; Hardersen, Paul; Harshaw, Richard; Johnson, Jolyon Kafka, Stella; Kenney, John; Mohanan, Kakkala; Ridgely, John; Rowe, David Silliman, Mark; Stojimirovic, Irena; Tock, Kalee; Walker, Douglas; Wallen, Vera

2017-06-01

Social learning theory suggests that students who wish to become scientists will benefit by being active researchers early in their educational careers. As coauthors of published research, they identify themselves as scientists. This provides them with the inspiration, motivation, and staying power that many will need to complete the long educational process. This hypothesis was put to the test over the past decade by a one-semester astronomy research seminar where teams of students managed their own research. Well over a hundred published papers coauthored by high school and undergraduate students at a handful of schools substantiated this hypothesis. However, one could argue that this was a special case. Astronomy, after all, is supported by a large professional-amateur community-of-practice. Furthermore, the specific area of research-double star astrometry-was chosen because the observations could be quickly made, the data reduction and analysis was straight forward, and publication of the research was welcomed by the Journal of Double Star Observations. A recently initiated seminar development and expansion program-supported in part by the National Science Foundation-is testing a more general hypothesis that: (1) the seminar can be successfully adopted by many other schools; (2) research within astronomy can be extended from double star astrometry to time series photometry of variable stars, exoplanet transits, and asteroids; and (3) the seminar model can be extended to a science beyond astronomy: environmental science-specifically atmospheric science. If the more general hypothesis is also supported, seminars that similarly feature published high school and undergraduate student team research could have the potential to significantly improve science education by increasing the percentage of students who complete the education required to become professional scientists.

New Planar Wire Array Experiments on the LTD Generator at U Michigan

NASA Astrophysics Data System (ADS)

Weller, M. E.; Safronova, A. S.; Kantsyrev, V. L.; Shrestha, I.; Shlyaptseva, V. V.; Cooper, M. C.; Lorance, M. Y.; Stafford, A.; Petkov, E. E.; Jordan, N. M.; Patel, S. G.; Steiner, A. M.; Yager-Elorriaga, D. A.; Gilgenbach, R. M.

2014-10-01

Experiments on planar wire array z-pinches have been carried out on the MAIZE Linear Transformer Driver (LTD) generator at the University of Michigan (UM) for the first time. Specifically, Al (Al 5056, 95% Al, 5% Mg) double planar wire arrays (DPWAs) comprising six wires in each plane with interplanar gaps of 3.0 mm and 6.0 mm and interwire gaps of 0.7 mm and 1.0 mm were imploded with x-ray time-integrated spectra indicating electron temperatures of over 450 eV for K-shell Al and Mg, while producing mostly optically thin lines. In addition to x-ray time-integrated spectra, the diagnostics included x-ray time-integrated pinhole cameras, two silicon diodes, and shadowgraphy, which are analyzed and compared. The MAIZE LTD is capable of supplying up 1.0 MA, 100 kV pulses with 100 ns rise time into a matched load. However, for these experiments the LTD was charged to +-70 kV resulting in up to 0.5 MA with a current rise time of approximately 150 ns. Future experiments and the importance of studying planar wire arrays on LTD devices are discussed. This work supported by NNSA under DOE Cooperative Agreement DE-NA0001984. S. Patel & A. Steiner supported by Sandia. D. Yager-Elorriaga supported by NSF GF.

Comparison of Pelican single-use multibite biopsy forceps and traditional double-bite forceps: evaluation in a porcine model.

PubMed

Zaidman, Jeffrey S; Frederick, William G; Furth, Emma E; Su, Chinyu G; Ginsberg, Gregory G

2006-10-01

The multibite biopsy forceps is intended for consecutive acquisition of numerous tissue specimens with a single pass. The Pelican multibite forceps is equipped with a sleeve for tissue retention that allows up to 6 specimens to be obtained with each pass of the device through the accessory channel. Reducing the need for device exchange could decrease the total procedure time for colon cancer surveillance in patients with longstanding inflammatory bowel disease (IBD). The aim of this study was to evaluate a new multibite biopsy forceps in comparison with a standard double-bite forceps. Prospective randomized animal model trial. Multicenter university and community hospitals. By using a live porcine model, multiple colonoscopic biopsy specimens were obtained with both the Pelican multibite forceps and the Radial Jaw 3 (RJ3) double-bite forceps to mimic colorectal cancer surveillance in patients with IBD. Six biopsy specimens were obtained with each of 6 passes when using the Pelican forceps, and 2 biopsy specimens were obtained with each of 18 passes when using the RJ3 forceps. All trials were timed. Two independent pathologists blinded to the forceps used evaluated the specimens. Tissue acquisition when using the Pelican multibite forceps was significantly faster than with a standard double-bite forceps. The devices compared equivalently for specimen retention and quality. The operator could not be blinded to the devices used. This study uses an animal model to extrapolate how the devices might perform in human use. These findings support the evaluation of the Pelican forceps for colon cancer surveillance in patients with longstanding IBD.

Fiscal Year 2011 United States Army Annual Financial Report. America’s Army: At a Strategic Crossroads

DTIC Science & Technology

2011-01-01

successful in any operational scenario. In FY 2011, the Army updated the Cost of the Doctrinal Army Model using improved and refined methods and the...8,100 severely wounded Soldiers and veterans with cases spanning from Post- Traumatic Stress Disorder to double amputees. This population is supported... method dubbed “EoIP” (Everything over Internet Protocol). Getting the right information at the right time requires universal accessibility

The double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2-428.

PubMed

Santander-García, M; Rodríguez-Gil, P; Corradi, R L M; Jones, D; Miszalski, B; Boffin, H M J; Rubio-Díez, M M; Kotze, M M

2015-03-05

The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (M(⊙)). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche lobe as the star expands during the asymptotic giant branch phase. The excess gas eventually forms a common envelope surrounding both stars. Drag forces then result in the envelope being ejected into a bipolar planetary nebula whose equator is coincident with the orbital plane of the system. Systems in which both stars have ejected their envelopes and are evolving towards the white dwarf stage are said to be double degenerate. Here we report that Henize 2-428 has a double-degenerate core with a combined mass of ∼1.76M(⊙), which is above the Chandrasekhar limit (the maximum mass of a stable white dwarf) of 1.4M(⊙). This, together with its short orbital period (4.2 hours), suggests that the system should merge in 700 million years, triggering a type Ia supernova event. This supports the hypothesis of the double-degenerate, super-Chandrasekhar evolutionary pathway for the formation of type Ia supernovae.

A Micro-Computer Based Decision Support System for Response Surface Methodology

DTIC Science & Technology

1990-03-01

d = -(a+em) *(gab+en)*x/ ((a+tem) *(qap+tem)); app = ap+d*az; bpp = bp+d*bz; aold = az; am = ap/ bpp ; bm = bp/ bpp ; az = app/ bpp ; bz = 1.0; if (( fabs (az...x = x+one; ser = ser+cof[j]/x; ) return (tmp+log(stp*ser));) double betacf(a,b,x) double a, b, x; ( double tem,qapqam,qab,em,d; double bz, bpp ,bp,bm...aold)) < (eps* fabs (az))) goto done; printf("lpause in BETACF\

Accessing the biocompatibility of layered double hydroxide by intramuscular implantation: histological and microcirculation evaluation

PubMed Central

Cunha, Vanessa Roberta Rodrigues; de Souza, Rodrigo Barbosa; da Fonseca Martins, Ana Maria Cristina Rebello Pinto; Koh, Ivan Hong Jun; Constantino, Vera Regina Leopoldo

2016-01-01

Biocompatibility of layered double hydroxides (LDHs), also known as hydrotalcite-like materials or double metal hydroxides, was investigated by in vivo assays via intramuscular tablets implantation in rat abdominal wall. The tablets were composed by chloride ions intercalated into LDH of magnesium/aluminum (Mg2Al-Cl) and zinc/aluminum (Zn2Al-Cl). The antigenicity and tissue integration capacity of LDHs were assessed histologically after 7 and 28 days post-implantation. No fibrous capsule nearby the LDH was noticed for both materials as well any sign of inflammatory reactions. Sidestream Dark Field imaging, used to monitor in real time the microcirculation in tissues, revealed overall integrity of the microcirculatory network neighboring the tablets, with no blood flow obstruction, bleeding and/or increasing of leukocyte endothelial adhesion. After 28 days Mg2Al-Cl promoted multiple collagen invaginations (mostly collagen type-I) among its fragments while Zn2Al-Cl induced predominantly collagen type–III. This work supports previous results in the literature about LDHs compatibility with living matter, endorsing them as functional materials for biomedical applications. PMID:27480483

The Double Burden of Undernutrition and Overnutrition in Developing Countries: an Update.

PubMed

Abdullah, Asnawi

2015-09-01

Many developing countries have achieved a remarkable improvement in nutrition status in the past decades. However, the prevalence of undernutrition remains a serious problem. At the same time, the prevalence of obesity is increasing substantially, and in some countries, it has approached that of developed countries. This article provides an update on this double burden of malnutrition (DBMN) in developing nations. One hundred countries (lower, middle-lower, and upper-middle income countries) were selected and analysed, and to support the analysis, a systematic review of current published studies was performed. The results show that DBMN already exists in almost all developing countries and that the DBMN ratio (i.e., overweight/underweight) has increased as income per capita has increased. DBMN may manifest within the community, household, or individual. In addition to common factors, poor nutrition in early childhood is suggested as another important driving factor behind the rising obesity rate in most developing countries. A life-course approach has been proposed to prevent undernutrition and overnutrition and should be integrated into the development of health systems to control double burden in developing countries.

Accessing the biocompatibility of layered double hydroxide by intramuscular implantation: histological and microcirculation evaluation.

PubMed

Cunha, Vanessa Roberta Rodrigues; de Souza, Rodrigo Barbosa; da Fonseca Martins, Ana Maria Cristina Rebello Pinto; Koh, Ivan Hong Jun; Constantino, Vera Regina Leopoldo

2016-08-02

Biocompatibility of layered double hydroxides (LDHs), also known as hydrotalcite-like materials or double metal hydroxides, was investigated by in vivo assays via intramuscular tablets implantation in rat abdominal wall. The tablets were composed by chloride ions intercalated into LDH of magnesium/aluminum (Mg2Al-Cl) and zinc/aluminum (Zn2Al-Cl). The antigenicity and tissue integration capacity of LDHs were assessed histologically after 7 and 28 days post-implantation. No fibrous capsule nearby the LDH was noticed for both materials as well any sign of inflammatory reactions. Sidestream Dark Field imaging, used to monitor in real time the microcirculation in tissues, revealed overall integrity of the microcirculatory network neighboring the tablets, with no blood flow obstruction, bleeding and/or increasing of leukocyte endothelial adhesion. After 28 days Mg2Al-Cl promoted multiple collagen invaginations (mostly collagen type-I) among its fragments while Zn2Al-Cl induced predominantly collagen type-III. This work supports previous results in the literature about LDHs compatibility with living matter, endorsing them as functional materials for biomedical applications.

An Evaluation of optional timing/synchronization features to support selection of an optimum design for the DCS digital communication network

NASA Technical Reports Server (NTRS)

Bradley, D. B.; Cain, J. B., III; Williard, M. W.

1978-01-01

The task was to evaluate the ability of a set of timing/synchronization subsystem features to provide a set of desirable characteristics for the evolving Defense Communications System digital communications network. The set of features related to the approaches by which timing/synchronization information could be disseminated throughout the network and the manner in which this information could be utilized to provide a synchronized network. These features, which could be utilized in a large number of different combinations, included mutual control, directed control, double ended reference links, independence of clock error measurement and correction, phase reference combining, and self organizing.

Abnormal gait pattern emerges during curved trajectories in high-functioning Parkinsonian patients walking in line at normal speed

PubMed Central

Godi, Marco; Giardini, Marica; Arcolin, Ilaria; Nardone, Antonio; Giordano, Andrea; Schieppati, Marco

2018-01-01

Background Several patients with Parkinson´s disease (PD) can walk normally along straight trajectories, and impairment in their stride length and cadence may not be easily discernible. Do obvious abnormalities occur in these high-functioning patients when more challenging trajectories are travelled, such as circular paths, which normally implicate a graded modulation in the duration of the interlimb gait cycle phases? Methods We compared a cohort of well-treated mildly to moderately affected PD patients to a group of age-matched healthy subjects (HS), by deliberately including HS spontaneously walking at the same speed of the patients with PD. All participants performed, in random order: linear and circular walking (clockwise and counter-clockwise) at self-selected speed. By means of pressure-sensitive insoles, we recorded walking speed, cadence, duration of single support, double support, swing phase, and stride time. Stride length-cadence relationships were built for linear and curved walking. Stride-to-stride variability of temporal gait parameters was also estimated. Results Walking speed, cadence or stride length were not different between PD and HS during linear walking. Speed, cadence and stride length diminished during curved walking in both groups, stride length more in PD than HS. In PD compared to HS, the stride length-cadence relationship was altered during curved walking. Duration of the double-support phase was also increased during curved walking, as was variability of the single support, swing phase and double support phase. Conclusion The spatio-temporal gait pattern and variability are significantly modified in well-treated, high-functioning patients with PD walking along circular trajectories, even when they exhibit no changes in speed in straight-line walking. The increased variability of the gait phases during curved walking is an identifying characteristic of PD. We discuss our findings in term of interplay between control of balance and of locomotor progression: the former is challenged by curved trajectories even in high-functioning patients, while the latter may not be critically affected. PMID:29750815

Double layer mixed matrix membrane adsorbers improving capacity and safety hemodialysis

NASA Astrophysics Data System (ADS)

Saiful; Borneman, Z.; Wessling, M.

2018-05-01

Double layer mixed matrix membranes adsorbers have been developed for blood toxin removal by embedding activated carbon into cellulose acetate macroporous membranes. The membranes are prepared by phase inversion method via water vapor induced phase separation followed by an immersion precipitation step. Double layer MMM consisting of an active support and a separating layer. The active support layer consists of activated carbon particles embedded in macroporous cellulose acetate; the separating layer consists of particle free cellulose acetate. The double layer membrane possess an open and interconnected macroporous structure with a high loading of activated carbon available for blood toxins removal. The MMM AC has a swelling degree of 6.5 %, porosity of 53 % and clean water flux of 800 Lm-2h-1bar-1. The prepared membranes show a high dynamic Creatinine (Crt) removal during hemodilysis process. The Crt removal by adsorption contributes to amore than 83 % of the total removal. The double layer adsorptive membrane proves hemodialysis membrane can integrated with adsorption, in which blood toxins are removed in one step.

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

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

Ahmed, Nesreen S.; Surface Chemistry and Catalytic Studies Group, King Abdulaziz University; Menzel, Robert

Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%,more » respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH. - Graphical abstract: CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary, two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. - Highlights: • CuAl LDH/GO and CoAl LDH/GO hybrid materials with different LDH compositions were prepared. • Hybrids were fully characterised and their catalytic efficiency over the Classic Ullman Reaction was studied. • CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) in 25 min reaction times. • GO provides a light-weight, charge complementary, two-dimensional material that interacts effectively with the 2D LDHs. • After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.« less

Contributions of muscles and passive dynamics to swing initiation over a range of walking speeds.

PubMed

Fox, Melanie D; Delp, Scott L

2010-05-28

Stiff-knee gait is a common walking problem in cerebral palsy characterized by insufficient knee flexion during swing. To identify factors that may limit knee flexion in swing, it is necessary to understand how unimpaired subjects successfully coordinate muscles and passive dynamics (gravity and velocity-related forces) to accelerate the knee into flexion during double support, a critical phase just prior to swing that establishes the conditions for achieving sufficient knee flexion during swing. It is also necessary to understand how contributions to swing initiation change with walking speed, since patients with stiff-knee gait often walk slowly. We analyzed muscle-driven dynamic simulations of eight unimpaired subjects walking at four speeds to quantify the contributions of muscles, gravity, and velocity-related forces (i.e. Coriolis and centrifugal forces) to preswing knee flexion acceleration during double support at each speed. Analysis of the simulations revealed contributions from muscles and passive dynamics varied systematically with walking speed. Preswing knee flexion acceleration was achieved primarily by hip flexor muscles on the preswing leg with assistance from biceps femoris short head. Hip flexors on the preswing leg were primarily responsible for the increase in preswing knee flexion acceleration during double support with faster walking speed. The hip extensors and abductors on the contralateral leg and velocity-related forces opposed preswing knee flexion acceleration during double support. Copyright 2010 Elsevier Ltd. All rights reserved.

Contributions of muscles and passive dynamics to swing initiation over a range of walking speeds

PubMed Central

Fox, Melanie D.; Delp, Scott L.

2010-01-01

Stiff-knee gait is a common walking problem in cerebral palsy characterized by insufficient knee flexion during swing. To identify factors that may limit knee flexion in swing, it is necessary to understand how unimpaired subjects successfully coordinate muscles and passive dynamics (gravity and velocity-related forces) to accelerate the knee into flexion during double support, a critical phase just prior to swing that establishes the conditions for achieving sufficient knee flexion during swing. It is also necessary to understand how contributions to swing initiation change with walking speed, since patients with stiff-knee gait often walk slowly. We analyzed muscle-driven dynamic simulations of eight unimpaired subjects walking at four speeds to quantify the contributions of muscles, gravity, and velocity-related forces (i.e. Coriolis and centrifugal forces) to preswing knee flexion acceleration during double support at each speed. Analysis of the simulations revealed contributions from muscles and passive dynamics varied systematically with walking speed. Preswing knee flexion acceleration was achieved primarily by hip flexor muscles on the preswing leg with assistance from biceps femoris short head. Hip flexors on the preswing leg were primarily responsible for the increase in preswing knee flexion acceleration during double support with faster walking speed. The hip extensors and abductors on the contralateral leg and velocity-related forces opposed preswing knee flexion acceleration during double support. PMID:20236644

Forecasting Hourly Water Demands With Seasonal Autoregressive Models for Real-Time Application

NASA Astrophysics Data System (ADS)

Chen, Jinduan; Boccelli, Dominic L.

2018-02-01

Consumer water demands are not typically measured at temporal or spatial scales adequate to support real-time decision making, and recent approaches for estimating unobserved demands using observed hydraulic measurements are generally not capable of forecasting demands and uncertainty information. While time series modeling has shown promise for representing total system demands, these models have generally not been evaluated at spatial scales appropriate for representative real-time modeling. This study investigates the use of a double-seasonal time series model to capture daily and weekly autocorrelations to both total system demands and regional aggregated demands at a scale that would capture demand variability across a distribution system. Emphasis was placed on the ability to forecast demands and quantify uncertainties with results compared to traditional time series pattern-based demand models as well as nonseasonal and single-seasonal time series models. Additional research included the implementation of an adaptive-parameter estimation scheme to update the time series model when unobserved changes occurred in the system. For two case studies, results showed that (1) for the smaller-scale aggregated water demands, the log-transformed time series model resulted in improved forecasts, (2) the double-seasonal model outperformed other models in terms of forecasting errors, and (3) the adaptive adjustment of parameters during forecasting improved the accuracy of the generated prediction intervals. These results illustrate the capabilities of time series modeling to forecast both water demands and uncertainty estimates at spatial scales commensurate for real-time modeling applications and provide a foundation for developing a real-time integrated demand-hydraulic model.

Chern Numbers Hiding in Time of Flight Images

NASA Astrophysics Data System (ADS)

Satija, Indubala; Zhao, Erhai; Ghosh, Parag; Bray-Ali, Noah

2011-03-01

Since the experimental realization of synthetic magnetic fields in neural ultracold atoms, transport measurement such as quantized Hall conductivity remains an open challenge. Here we propose a novel and feasible scheme to measure the topological invariants, namely the chern numbers, in the time of flight images. We study both the commensurate and the incommensurate flux, with the later being the main focus here. The central concept underlying our proposal is the mapping between the chern numbers and the size of the dimerized states that emerge when the two-dimensional hopping is tuned to the highly anisotropic limit. In a uncoupled double quantum Hall system exhibiting time reversal invariance, only odd-sized dimer correlation functions are non-zero and hence encode quantized spin current. Finally, we illustrate that inspite of highly fragmented spectrum, a finite set of chern numbers are meaningful. Our results are supported by direct numerical computation of transverse conductivity. NBA acknowledges support from a National Research Council postdoctoral research associateship.

Current clinical use of reteplase for thrombolysis. A pharmacokinetic-pharmacodynamic perspective.

PubMed

Martin, U; Kaufmann, B; Neugebauer, G

1999-04-01

Clinical evaluation of a new thrombolytic agent should start with a dose that provides adequate efficacy and has an acceptably low bleeding risk; this results in a narrow therapeutic window at the upper end of the dose-response curve. Angiographic patency of the infarct-related artery is still the clinical surrogate end-point for mortality in phase II dose-ranging studies. There is experimental and clinical evidence that the area under the concentration-time curve (AUC) for plasminogenolytic activity of a thrombolytic agent is positively correlated with patency of the infarct-related artery. Dose-ranging studies of the novel recombinant plasminogen activator reteplase in healthy volunteers enabled computation of a linear regression curve by which a clinical starting dose could be calculated for an adapted target AUC that would be clinically effective. Pharmacokinetic analysis also revealed that the half-life of reteplase is 4 times longer than that of the reference thrombolytic alteplase, thus allowing bolus injection. The suggested single bolus starting dose of 10U was supported by results from studies in a canine model of coronary thrombolysis. The feedback of insufficiently high patency rates compared with the increased efficacy of front-loaded and accelerated alteplase demanded optimisation strategies for reteplase. Animal experiments suggested that a double bolus regimen of reteplase would be preferable to doubling the single bolus dose. Pharmacokinetic modelling suggested a time interval of 30 min between the 2 bolus injections. Selection of the tested double bolus regimens was conservative and empirical. First, the previously tested single bolus of 15U was divided to 10 + 5U; secondly, the second bolus dose was increased to 10U. This strategy proved to be successful. The current dosage recommendation for reteplase is a double bolus intravenous injection of 10 + 10U, each over 2 min, 30 min apart. This produces a reduction in mortality in patients with acute myocardial infarction that is equivalent to that produced by front-loaded and accelerated infusion of alteplase.

A test of the stress-buffering model of social support in smoking cessation: is the relationship between social support and time to relapse mediated by reduced withdrawal symptoms?

PubMed

Creswell, Kasey G; Cheng, Yu; Levine, Michele D

2015-05-01

Social support has been linked to quitting smoking, but the mechanisms by which social support affects cessation are poorly understood. The current study tested a stress-buffering model of social support, which posits that social support protects or "buffers" individuals from stress related to quitting smoking. We hypothesized that social support would be negatively associated with risk of relapse, and that this effect would be mediated by reduced withdrawal and depressive symptoms (i.e., cessation-related stress) over time. Further, we predicted that trait neuroticism would moderate this mediational effect, such that individuals high in negative affectivity would show the greatest stress-buffering effects of social support. Participants were weight-concerned women (n = 349) ages 18-65 enrolled in a randomized, double-blind, placebo-controlled smoking cessation trial of bupropion and cognitive behavioral therapy. Social support was assessed at baseline, and biochemically-verified abstinence, withdrawal-related symptoms, and depressive symptoms were assessed at 1-, 3-, 6-, and 12-months follow-up. Social support was negatively related to risk of relapse in survival models and negatively related to withdrawal symptoms and depression in mixed effects models. These relationships held after controlling for the effects of pre-quit day negative affect and depression symptoms, assignment to treatment condition, and number of cigarettes smoked per day. A temporal mediation model showed that the effect of social support on risk of relapse was mediated by reductions in withdrawal symptoms over time but not by depression over time. Contrary to hypotheses, we did not find that neuroticism moderated this mediation effect. Increased social support may buffer women from the harmful effects of cessation-related withdrawal symptoms, which in turn improve cessation outcomes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Test of the Stress-Buffering Model of Social Support in Smoking Cessation: Is the Relationship Between Social Support and Time to Relapse Mediated by Reduced Withdrawal Symptoms?

PubMed Central

Cheng, Yu; Levine, Michele D.

2015-01-01

Introduction: Social support has been linked to quitting smoking, but the mechanisms by which social support affects cessation are poorly understood. The current study tested a stress-buffering model of social support, which posits that social support protects or “buffers” individuals from stress related to quitting smoking. We hypothesized that social support would be negatively associated with risk of relapse, and that this effect would be mediated by reduced withdrawal and depressive symptoms (i.e., cessation-related stress) over time. Further, we predicted that trait neuroticism would moderate this mediational effect, such that individuals high in negative affectivity would show the greatest stress-buffering effects of social support. Methods: Participants were weight-concerned women (n = 349) ages 18–65 enrolled in a randomized, double-blind, placebo-controlled smoking cessation trial of bupropion and cognitive behavioral therapy. Social support was assessed at baseline, and biochemically-verified abstinence, withdrawal-related symptoms, and depressive symptoms were assessed at 1-, 3-, 6-, and 12-months follow-up. Results: Social support was negatively related to risk of relapse in survival models and negatively related to withdrawal symptoms and depression in mixed effects models. These relationships held after controlling for the effects of pre-quit day negative affect and depression symptoms, assignment to treatment condition, and number of cigarettes smoked per day. A temporal mediation model showed that the effect of social support on risk of relapse was mediated by reductions in withdrawal symptoms over time but not by depression over time. Contrary to hypotheses, we did not find that neuroticism moderated this mediation effect. Conclusions: Increased social support may buffer women from the harmful effects of cessation-related withdrawal symptoms, which in turn improve cessation outcomes. PMID:25257978

Therapeutic horse riding improves cognition, mood arousal, and ambulation in children with dyspraxia.

PubMed

Hession, Caren E; Eastwood, Brian; Watterson, David; Lehane, Christine M; Oxley, Nigel; Murphy, Barbara A

2014-01-01

The objectives of this study were to evaluate the effects of the physical motion of a horse (riding therapy) combined with the audiovisual perception of this motion on a group of children with dyspraxia in terms of cognition, mood arousal, and gait variability. The study design was a pretest/post-test. The study was conducted at the Fettercairn Youth Horse Project, Fettercairn, Tallaght, Dublin. Forty (40) children ranging from 6 to 15 years of age with a primary diagnosis of dyspraxia were the study subjects. Children meeting inclusion criteria participated in six 30-minute horse-riding sessions and two 30-minute audiovisual screening sessions. A Standard Progressive Matrices test (also known as the Ravens test) was used to measure aspects of general intelligence. A Childhood Depression Inventory (CDI) questionnaire was used to assess cognitive, affective, and behavioral signs of depression. A GAITRite Pressure Mapping System analyzed foot function and gait variability by measuring single and double support, cycle time, cadence, toe in/out, and stride length. Significant improvements were evident on the Ravens test and the CDI by the end of the study period. The amount of both single and double support required while completing the walking task also was significantly reduced. Improvements were visible on toe in/out values, cycle time, and cadence. Changes in stride length did not reach statistical significance. These findings support the theory that riding therapy and/or the perception of beat-based rhythms, as experienced by the rider on the horse, stimulates cognition, mood, and gait parameters. In addition, the data also pointed to the potential value of an audiovisual approach to equine therapy.

Effect of transversus abdominis plane block in combination with general anesthesia on perioperative opioid consumption, hemodynamics, and recovery in living liver donors: The prospective, double-blinded, randomized study.

PubMed

Erdogan, Mehmet A; Ozgul, Ulku; Uçar, Muharrem; Yalin, Mehmet R; Colak, Yusuf Z; Çolak, Cemil; Toprak, Huseyin I

2017-04-01

Transversus abdominis plane (TAP) block provides effective postoperative analgesia after abdominal surgeries. It can be also a useful strategy to reduce perioperative opioid consumption, support intraoperative hemodynamic stability, and promote early recovery from anesthesia. The aim of this prospective randomized double-blind study was to assess the effect of subcostal TAP blocks on perioperative opioid consumption, hemodynamic, and recovery time in living liver donors. The prospective, double-blinded, randomized controlled study was conducted with 49 living liver donors, aged 18-65 years, who were scheduled to undergo right hepatectomy. Patients who received subcostal TAP block in combination with general anesthesia were allocated into Group 1, and patients who received general anesthesia alone were allocated into Group 2. The TAP blocks were performed bilaterally by obtaining an image with real-time ultrasound guidance using 0.5% bupivacaine diluted with saline to reach a total volume of 40 mL. The primary outcome measure in our study was perioperative remifentanil consumption. Secondary outcomes were mean blood pressure (MBP), heart rate (HR), mean desflurane requirement, anesthesia recovery time, frequency of emergency vasopressor use, total morphine use, and length of hospital stay. Total remifentanil consumption and the anesthesia recovery time were significantly lower in Group 1 compared with Group 2. Postoperative total morphine use and length of hospital stay were also reduced. Changes in the MAP and HR were similar in the both groups. There were no significant differences in HR and MBP between groups at any time. Combining subcostal TAP blocks with general anesthesia significantly reduced perioperative and postoperative opioid consumption, provided shorter anesthesia recovery time, and length of hospital stay in living liver donors. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Historical contingency and ecological determinism interact to prime speciation in sticklebacks, Gasterosteus.

PubMed Central

Taylor, E B; McPhail, J D

2000-01-01

Historical contingency and determinism are often cast as opposing paradigms under which evolutionary diversification operates. It may be, however, that both factors act together to promote evolutionary divergence, although there are few examples of such interaction in nature. We tested phylogenetic predictions of an explicit historical model of divergence (double invasions of freshwater by marine ancestors) in sympatric species of three-spined sticklebacks (Gasterosteus aculeatus) where determinism has been implicated as an important factor driving evolutionary novelty. Microsatellite DNA variation at six loci revealed relatively low genetic variation in freshwater populations, supporting the hypothesis that they were derived by colonization of freshwater by more diverse marine ancestors. Phylogenetic and genetic distance analyses suggested that pairs of sympatric species have evolved multiple times, further implicating determinism as a factor in speciation. Our data also supported predictions based on the hypothesis that the evolution of sympatric species was contingent upon 'double invasions' of postglacial lakes by ancestral marine sticklebacks. Sympatric sticklebacks, therefore, provide an example of adaptive radiation by determinism contingent upon historical conditions promoting unique ecological interactions, and illustrate how contingency and determinism may interact to generate geographical variation in species diversity PMID:11133026

Layered double hydroxide supported gold nanoclusters by glutathione-capped Au nanoclusters precursor method for highly efficient aerobic oxidation of alcohols.

PubMed

Li, Lun; Dou, Liguang; Zhang, Hui

2014-04-07

M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 ± 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ∼0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h(-1)) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.

J-tube technique for double-j stent insertion during laparoscopic upper urinary tract surgical procedures.

PubMed

Kim, Hyung Suk; Lee, Byung Ki; Jung, Jin-Woo; Lee, Jung Keun; Byun, Seok-Soo; Lee, Sang Eun; Jeong, Chang Wook

2014-11-01

Double-J stent insertion has been generally performed during laparoscopic upper urinary tract (UUT) surgical procedures to prevent transient urinary tract obstruction and postoperative flank pain from ureteral edema and blood clots. Several restrictive conditions that make this procedure difficult and time consuming, however, include the coiled distal ends of the flexible Double-J stent and the limited bending angle of the laparoscopic instruments. To overcome these limitations, we devised a Double-J stent insertion method using the new J-tube technique. Between July 2011 and May 2013, Double-J stents were inserted using the J-tube technique in 33 patients who underwent a laparoscopic UUT surgical procedure by a single surgeon. The mean stent placement time was 4.8±2.7 minutes, and there were no intraoperative complications. In conclusion, the J-tube technique is a safe and time-saving method for Double-J stent insertion during laparoscopic surgical procedures.

Buffered Lidocaine With Sodium Bicarbonate did not Increase Inferior Alveolar Nerve Block Success Rate in Patients Having Symptomatic Irreversible Pulpitis.

PubMed

Parirokh, Masoud

2016-03-01

Effect of buffered 4% lidocaine on the success of the inferior alveolar nerve block in patients with symptomatic irreversible pulpitis: a prospective, randomized, double-blind study. Schellenberg J, Drum M, Reader A, Nusstein J, Fowler S, Beck M. J Endod 2015;41(6):791-6. The study was supported by Meyers/Reader Graduate Endodontic Support Fund Double blinded randomized controlled trial. Copyright © 2016 Elsevier Inc. All rights reserved.

Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators.

PubMed

Laroia, N; Phelps, D L; Roy, J

2007-04-18

Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment. To assess the effects of double walled incubator versus a single wall incubator on insensible water loss, rate of oxygen consumption, episodes of hypothermia, time to regain birth weight, duration of hospitalization and infant mortality in premature infants. The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of electronic databases: Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966 - 2006), EMBASE, previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants in all published languages, and CINAHL (1982 - 2006). Only studies using random or quasi-random methods of allocation were considered for this review. Eligible studies assessed at least one of the outcome variables identified as important to this topic. Independent data extraction and quality assessment of included trials was conducted by the review authors. Data were analyzed using generic inverse variance methodology and weighted mean difference (WMD). Results are presented with 95% confidence intervals. Meta-analysis was undertaken using a fixed effect model. Three studies met the criteria. Four other studies were excluded, as they did not compare double versus single wall incubators (details of the studies are given in the included and excluded studies section). Double wall incubators have the advantage of decreasing heat loss, decreasing heat production and decreasing radiant heat loss when compared to single wall incubators. There is also the advantage of reduced oxygen consumption. A minimal increase in conductive heat loss was noted when compared to single wall incubators. All of these effects are small and do not support the proposition that double wall incubators have a beneficial effect on long term outcomes including mortality or the duration of hospitalization. Although it appears that caring for extremely small infants in double wall incubators may theoretically result in shorter hospitalization and may have metabolic advantages, this review was unable to find any data in the literature to support or refute this hypothesis. The studies do not provide any evidence that the small decrease in heat loss improves clinical outcome. Therefore, the available data is insufficient to directly guide clinical practice.

Indirect double photoionization of water

NASA Astrophysics Data System (ADS)

Resccigno, T. N.; Sann, H.; Orel, A. E.; Dörner, R.

2011-05-01

The vertical double ionization thresholds of small molecules generally lie above the dissociation limits corresponding to formation of two singly charged fragments. This gives the possibility of populating singly charged molecular ions by photoionization in the Franck-Condon region at energies below the lowest dication state, but above the dissociation limit into two singly charged fragment ions. This process can produce a superexcited neutral fragment that autoionizes at large internuclear separation. We study this process in water, where absorption of a photon produces an inner-shell excited state of H2O+ that fragments to H++OH*. The angular distribution of secondary electrons produced by OH* when it autoionizes produces a characteristic asymmetric pattern that reveals the distance, and therefore the time, at which the decay takes place. LBNL, Berkeley, CA, J. W. Goethe Universität, Frankfurt, Germany. Work performed under auspices of US DOE and supported by OBES, Div. of Chemical Sciences.

Fascin-1 knock-down of human glioma cells reduces their microvilli/filopodia while improving their susceptibility to lymphocyte-mediated cytotoxicity

PubMed Central

Hoa, Neil T; Ge, Lisheng; Erickson, Kate L; Kruse, Carol A; Cornforth, Andrew N; Kuznetsov, Yurii; McPherson, Alex; Martini, Filippo; Jadus, Martin R

2015-01-01

Cancer cells derived from Glioblastoma multiforme possess membranous protrusions allowing these cells to infiltrate surrounding tissue, while resisting lymphocyte cytotoxicity. Microvilli and filopodia are supported by actin filaments cross-linked by fascin. Fascin-1 was genetically silenced within human U251 glioma cells; these knock-down glioma cells lost their microvilli/filopodia. The doubling time of these fascin-1 knock-down cells was doubled that of shRNA control U251 cells. Fascin-1 knock-down cells lost their transmigratory ability responding to interleukin-6 or insulin-like growth factor-1. Fascin-1 silenced U251 cells were more easily killed by cytolytic lymphocytes. Fascin-1 knock-down provides unique opportunities to augment glioma immunotherapy by simultaneously targeting several key glioma functions: like cell transmigration, cell division and resisting immune responses. PMID:25901196

Double Scaling in the Relaxation Time in the β -Fermi-Pasta-Ulam-Tsingou Model

NASA Astrophysics Data System (ADS)

Lvov, Yuri V.; Onorato, Miguel

2018-04-01

We consider the original β -Fermi-Pasta-Ulam-Tsingou system; numerical simulations and theoretical arguments suggest that, for a finite number of masses, a statistical equilibrium state is reached independently of the initial energy of the system. Using ensemble averages over initial conditions characterized by different Fourier random phases, we numerically estimate the time scale of equipartition and we find that for very small nonlinearity it matches the prediction based on exact wave-wave resonant interaction theory. We derive a simple formula for the nonlinear frequency broadening and show that when the phenomenon of overlap of frequencies takes place, a different scaling for the thermalization time scale is observed. Our result supports the idea that the Chirikov overlap criterion identifies a transition region between two different relaxation time scalings.

In vivo measurement of the potential doubling time by flowcytometry in oropharyngeal cancer treated by conventional radiotherapy.

PubMed

Bourhis, J; Wilson, G; Wibault, P; Bosq, J; Chavaudra, N; Janot, F; Luboinski, B; Eschwege, F; Malaise, E P

1993-08-01

Experimental and clinical studies suggest that the pre-treatment potential doubling time could be predictive of tumor control in patients treated by conventional radiotherapy and could help to identify the rapidly growing tumors for which accelerated radiotherapy is required. To test this hypothesis, we studied prospectively 48 patients with a squamous cell carcinoma of the oropharynx and treated by conventional radiotherapy (70 Gy/7 weeks). The duration of S phase, the labeling index and the potential doubling time were obtained by flowcytometry measurements of a tumor biopsy obtained after injection of 200 mg bromodeoxyuridine to the patient. Three parameters were significantly associated with an increased risk of relapse namely the tumors size (T4; p < 0.01), the nodal status (> or = N2; p < 0.05) and the site of the primary within the oropharynx (p = 0.08). The S phase, labeling index, DNA index and potential doubling time were not significantly associated with an increased risk of relapse. However when considering only the T2 subgroup of patients, high labeling indexes and short potential doubling time were associated with an increased risk of relapse: the mean pre-treatment potential doubling time of the tumors which relapsed was 3.21 versus 5.5 days when there was no evidence of local relapse (p < 0.05). The mean labeling index for the group of tumors associated with a tumor recurrence was 11.7% compared to 7.3% when there was no evidence of relapse (p = 0.02). Factors other than proliferation play a role in determining the outcome of oropharyngeal cancers treated by conventional radiotherapy. However there was a significant correlation between short potential doubling time, high labeling index and tumor recurrence in the T2 subgroup of patients. The finding of significance for potential doubling time and labeling index in the T2 subset of tumors may be a reflexion of the more homogeneous nature of these tumors with regard to prognostic variables.

11. Corner of Derrick Showing Bolted Joints and DoublePipe/Wood Beam ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Corner of Derrick Showing Bolted Joints and Double-Pipe/Wood Beam Support For Bull Wheel, Looking Southeast - David Renfrew Oil Rig, East side of Connoquenessing Creek, 0.4 mile North of confluence with Thorn Creek, Renfrew, Butler County, PA

Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

PubMed

Beaulieu, M L; Palmieri-Smith, R M

2014-08-01

Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Biomechanical characteristics of single-row repair in comparison to double-row repair with consideration of the suture configuration and suture material.

PubMed

Baums, M H; Buchhorn, G H; Spahn, G; Poppendieck, B; Schultz, W; Klinger, H-M

2008-11-01

The aim of the study was to evaluate the time zero mechanical properties of single- versus double-row configuration for rotator cuff repair in an animal model with consideration of the stitch technique and suture material. Thirty-two fresh-frozen sheep shoulders were randomly assigned to four repair groups: suture anchor single-row repair coupled with (1) braided, nonabsorbable polyester suture sized USP No. 2 (SRAE) or (2) braided polyblend polyethylene suture sized No. 2 (SRAH). The double-row repair was coupled with (3) USP No. 2 (DRAE) or (4) braided polyblend polyethylene suture No. 2 (DRAH). Arthroscopic Mason-Allen stitches were used (single-row) and combined with medial horizontal mattress stitches (double-row). Shoulders were cyclically loaded from 10 to 180 N. Displacement to gap formation of 5- and 10-mm at the repair site, cycles to failure, and the mode of failure were determined. The ultimate tensile strength was verified in specimens that resisted to 3,000 cycles. DRAE and DRAH had a lower frequency of 5- (P = 0.135) and 10-mm gap formation (P = 0.135). All DRAE and DRAH resisted 3,000 cycles while only three SRAE and one SRAH resisted 3,000 cycles (P < 0.001). The ultimate tensile strength in double-row specimens was significantly higher than in others (P < 0.001). There was no significant variation in using different suture material (P > 0.05). Double-row suture anchor repair with arthroscopic Mason-Allen/medial mattress stitches provides initial strength superior to single-row repair with arthroscopic Mason-Allen stitches under isometric cyclic loading as well as under ultimate loading conditions. Our results support the concept of double-row fixation with arthroscopic Mason-Allen/medial mattress stitches in rotator cuff tears with improvement of initial fixation strength and ultimate tensile load. Use of new polyblend polyethylene suture material seems not to increase the initial biomechanical aspects of the repair construct.

Double checking: a second look

PubMed Central

Chreim, Samia; Forster, Alan

2015-01-01

Abstract Rationale, aims and objectives Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: ‘How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?’ Method This is part of a larger qualitative study based on 85 semi‐structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Results Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time‐consuming procedure, double checking trusted as an accepted and stand‐alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in‐family approach, and resilience. Conclusion(s) Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. PMID:26568537

Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.

PubMed

Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas

2015-07-01

In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

Daring the Foolish to Take Darwin Tests: The Ethical Double Bind of Betting On Natural Hazards

NASA Astrophysics Data System (ADS)

Halpern, J. B.

2017-12-01

While couched in the framework of concentrating minds betting on natural hazards carries an ethical cost. When children dare each other to do risky things parents know that when such dares are taken harm frequently occurs. Giving those who claim that there is no hazard financial reasons to avoid ameliorative actions or to double down in support of their public stance requires a moral calculation. Challenging the conclusions of those who accept such bets while denying danger will lead them to attempt to save face by increasing risk to themselves or others. Thus such wagers, whether person to person or on betting markets, require balancing between alerting the opposing party and others to the risks of not taking action, the associated scientific consensus and the possible harmful outcomes of the bets themselves. This talk will describe strategies for minimizing potential harm while maximizing the instructive component of climate bets. Best practices include having the bet rest on a technical issue that can be authoritatively resolved in a short time. Unfortunately the nature of natural hazard risks makes it difficult to meet all of these criteria, but those making such bets should be aware of the ethical double bind

Examining the nootropic effects of a special extract of Bacopa monniera on human cognitive functioning: 90 day double-blind placebo-controlled randomized trial.

PubMed

Stough, Con; Downey, Luke A; Lloyd, Jenny; Silber, Beata; Redman, Stephanie; Hutchison, Chris; Wesnes, Keith; Nathan, Pradeep J

2008-12-01

While Ayurvedic medicine has touted the cognitive enhancing effects of Bacopa monniera for centuries, there is a need for double-blind placebo-controlled investigations. One hundred and seven healthy participants were recruited for this double-blind placebo-controlled independent group design investigation. Sixty-two participants completed the study with 80% treatment compliance. Neuropsychological testing using the Cognitive Drug Research cognitive assessment system was conducted at baseline and after 90 days of treatment with a special extract of Bacopa monniera (2 x 150 mg KeenMind) or placebo. The Bacopa monniera product significantly improved performance on the 'Working Memory' factor, more specifically spatial working memory accuracy. The number of false-positives recorded in the Rapid visual information processing task was also reduced for the Bacopa monniera group following the treatment period. The current study provides support for the two other published studies reporting cognitive enhancing effects in healthy humans after a 90 day administration of the Bacopa monniera extract. Further studies are required to ascertain the effective dosage range, the time required to attain therapeutic levels and the effects over a longer term of administration. (c) 2008 John Wiley & Sons, Ltd.

Paediatric nurses' understanding of the process and procedure of double-checking medications.

PubMed

Dickinson, Annette; McCall, Elaine; Twomey, Bernadette; James, Natalie

2010-03-01

To understand paediatric nurses' understanding and practice regarding double-checking medication and identify facilitators and barriers to the process of independent double-checking (IDC). A system of double-checking medications has been proposed as a way of minimising medication error particularly in situations involving high-risk medications, complex processes such as calculating doses, or high-risk patient populations such as infants and children. While recommendations have been made in support of IDC in paediatric settings little is known about nursing practice and the facilitators and barriers to this process. A descriptive qualitative design was used. Data were collected via three focus group interviews. Six to seven paediatric nurses participated in homogenous groups based on level of practice. Data were analysed using thematic analysis. This study demonstrates that, while IDC is accepted and promoted as best practice in a paediatric setting, there is a lack of clarity as to what this means. This study supports other studies in relation to the influence of workload, distraction and environmental factors on the administration process but highlights the need for more research in relation to the impact of the power dynamic between junior and senior nurses. The issue of automaticity has been unexplored in relation to nursing practice but this study indicates that this may have an important influence on how care is delivered to patients. While the focus of this study was in the paediatric setting, the findings have relevance to other settings and population groups. The adoption of IDC in health care settings must have in place: policy and guidelines that clearly define the process of checking, educational support, an environment that supports peer critique and review, well-designed medication areas and accessible resources to support drug administration.

The effects of double-shifts (15.5 hours) on sleep, fatigue and health.

PubMed

Kecklund, G; Ekstedt, M; Akerstedt, T; Dahlgren, A; Samuelson, B

2001-12-01

The aim of the present study was to investigate how "double-shifts" (15.5 hours) affects sleep, fatigue and self-rated health. The study was carried out on male construction workers of which 80% were long-distance commuters. The schedule involved two work periods and each work period involved two double shifts in a row. The subjects filled in a sleep/wake diary at 8 times across a year and a questionnaire at 3 times. They also wore an actigraph during one shift cycle. The results showed that sleepiness, and to a certain extent, mental fatigue increased during double shifts and accumulated across days. The short rest time (8.5 hours) between days caused insufficient sleep and approximately 5.5 hours of sleep was obtained between double shifts. Questionnaire data showed that complaints of insufficient sleep, exhaustion on awakening and pain symptoms increased across the year. It was concluded that a shift system involving double shifts has a negative effect on fatigue, recovery and health-related well-being.

Testing the Double Bind Hypothesis: Faculty Recommendations of Minority Women Fellowship Applicants.

ERIC Educational Resources Information Center

Brown, Shirley Vining

1995-01-01

Examines faculty and scientist recommendations of applicants to the National Science Foundation's (NSF) Graduate Fellowship Program, 1976-91. Data from the Cumulative Index on National Science Foundation Fellowships Applicants and Awardees are used. Data analysis supports the double bind hypothesis that minority women are doubly disadvantaged…

Modeling early events in Francisella tularensis pathogenesis.

PubMed

Gillard, Joseph J; Laws, Thomas R; Lythe, Grant; Molina-París, Carmen

2014-01-01

Computational models can provide valuable insights into the mechanisms of infection and be used as investigative tools to support development of medical treatments. We develop a stochastic, within-host, computational model of the infection process in the BALB/c mouse, following inhalational exposure to Francisella tularensis SCHU S4. The model is mechanistic and governed by a small number of experimentally verifiable parameters. Given an initial dose, the model generates bacterial load profiles corresponding to those produced experimentally, with a doubling time of approximately 5 h during the first 48 h of infection. Analytical approximations for the mean number of bacteria in phagosomes and cytosols for the first 24 h post-infection are derived and used to verify the stochastic model. In our description of the dynamics of macrophage infection, the number of bacteria released per rupturing macrophage is a geometrically-distributed random variable. When combined with doubling time, this provides a distribution for the time taken for infected macrophages to rupture and release their intracellular bacteria. The mean and variance of these distributions are determined by model parameters with a precise biological interpretation, providing new mechanistic insights into the determinants of immune and bacterial kinetics. Insights into the dynamics of macrophage suppression and activation gained by the model can be used to explore the potential benefits of interventions that stimulate macrophage activation.

Double peak-induced distance error in short-time-Fourier-transform-Brillouin optical time domain reflectometers event detection and the recovery method.

PubMed

Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi

2015-10-01

The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system.

Development of a Double Glass Mounting Method Using Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) and its Evaluation for Permanent Mounting of Small Nematodes.

PubMed

Zahabiun, Farzaneh; Sadjjadi, Seyed Mahmoud; Esfandiari, Farideh

2015-01-01

Permanent slide preparation of nematodes especially small ones is time consuming, difficult and they become scarious margins. Regarding this problem, a modified double glass mounting method was developed and compared with classic method. A total of 209 nematode samples from human and animal origin were fixed and stained with Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) followed by double glass mounting and classic dehydration method using Canada balsam as their mounting media. The slides were evaluated in different dates and times, more than four years. Different photos were made with different magnification during the evaluation time. The double glass mounting method was stable during this time and comparable with classic method. There were no changes in morphologic structures of nematodes using double glass mounting method with well-defined and clear differentiation between different organs of nematodes in this method. Using this method is cost effective and fast for mounting of small nematodes comparing to classic method.

Development of a Double Glass Mounting Method Using Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) and its Evaluation for Permanent Mounting of Small Nematodes

PubMed Central

ZAHABIUN, Farzaneh; SADJJADI, Seyed Mahmoud; ESFANDIARI, Farideh

2015-01-01

Background: Permanent slide preparation of nematodes especially small ones is time consuming, difficult and they become scarious margins. Regarding this problem, a modified double glass mounting method was developed and compared with classic method. Methods: A total of 209 nematode samples from human and animal origin were fixed and stained with Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) followed by double glass mounting and classic dehydration method using Canada balsam as their mounting media. The slides were evaluated in different dates and times, more than four years. Different photos were made with different magnification during the evaluation time. Results: The double glass mounting method was stable during this time and comparable with classic method. There were no changes in morphologic structures of nematodes using double glass mounting method with well-defined and clear differentiation between different organs of nematodes in this method. Conclusion: Using this method is cost effective and fast for mounting of small nematodes comparing to classic method. PMID:26811729

The influence of double-credit evidence-based continuing medical education on presenters and learners.

PubMed

Lawrence, Steven L; Morzinski, Jeffrey A; Radjenovich, Mary Ellen

2008-07-01

Medical specialties are adopting methods to improve continuing medical education (CME). A "double credit" option, sponsored by the American Academy of Family Physicians, is now available for presentations submitted and approved as evidence based (EB). To compare usual and double-credit CME presentations to determine differences in preparation resources and time, and to compare conference attendees' satisfaction. Those not submitting double-credit applications were asked about perceived barriers. Three pretested, written surveys were administered at a 2.5 day CME conference held annually in Southeastern Wisconsin. Subjects were 38 presenters and 172 attendees, mostly primary care physicians. Twelve presentations were approved for double-credit; these presenters used a greater percentage of on-line EB resources to prepare their talks (64% versus 23%), and preparation required an additional 4.75 hours on average. Over 90% of attendees perceived greater conference quality due to the EB emphasis. Top barriers to double-credit EB applications were time limits and perceptions that topics were inappropriate. Double-credit presenters use a greater percentage of EB resources, while their counterparts used more professional experience to prepare CME presentations. Attendees reported improved quality and value with increased EB CME. Time is a perceived and real factor in preparing double-credit applications.

Lowering postprandial glycemia in children with type 1 diabetes after Italian pizza "margherita" (TyBoDi2 Study).

PubMed

De Palma, Alessandra; Giani, Elisa; Iafusco, Dario; Bosetti, Alessandra; Macedoni, Maddalena; Gazzarri, Alessandra; Spiri, Daniele; Scaramuzza, Andrea E; Zuccotti, Gian Vincenzo

2011-04-01

Continuous subcutaneous insulin infusion is considered a safe and effective way to administer insulin in pediatric patients with type 1 diabetes, but achieving satisfactory and stable glycemic control is difficult. Several factors contribute to control, including fine-tuning the basal infusion rate and bolus type and timing. We evaluated the most effective type and timing of a pump-delivered, preprandial bolus in children with type 1 diabetes for a pizza "margherita" meal. We assessed the response of 38 children with type 1 diabetes to a meal based on pizza "margherita" (with mozzarella cheese and tomato sauce) after different types and timings of a bolus dose. The glucose levels for 6 h after the meal were lower (i.e., closer to the therapeutic target of <140 mg/dL) when the bolus doses were administered as a simple bolus 15 min before the meal (area under the curve [AUC] 0-6 h, 6.9 ± 14.9 mg/dL/min) versus a simple bolus administered immediately before the meal (AUC 0-6 h, 4.2 ± 25.9 mg/dL/min) (P = not significant) versus a double-wave bolus 30/70 extended over a 6-h period administered 15 min before the meal (AUC 0-6 h, 1.9 ± 21.3 mg/dL/min) (P = not significant) versus a double-wave bolus 30/70 extended over a 6-h period administered immediately before the meal (AUC 0-6 h, 13.3 ± 15.6 mg/dL/min) (P = 0.01). In the case of a pizza "margherita," our data support the injection of the simple bolus 15 min before a meal, rather than immediately before or delivered as a double-wave bolus, to control the glycemic rise usually observed.

The Ship Movement Trajectory Prediction Algorithm Using Navigational Data Fusion.

PubMed

Borkowski, Piotr

2017-06-20

It is essential for the marine navigator conducting maneuvers of his ship at sea to know future positions of himself and target ships in a specific time span to effectively solve collision situations. This article presents an algorithm of ship movement trajectory prediction, which, through data fusion, takes into account measurements of the ship's current position from a number of doubled autonomous devices. This increases the reliability and accuracy of prediction. The algorithm has been implemented in NAVDEC, a navigation decision support system and practically used on board ships.

Investigation of potential of differential absorption Lidar techniques for remote sensing of atmospheric pollutants

NASA Technical Reports Server (NTRS)

Butler, C. F.; Shipley, S. T.; Allen, R. J.

1981-01-01

The NASA multipurpose differential absorption lidar (DIAL) system uses two high conversion efficiency dye lasers which are optically pumped by two frequency-doubled Nd:YAG lasers mounted rigidly on a supporting structure that also contains the transmitter, receiver, and data system. The DIAL system hardware design and data acquisition system are described. Timing diagrams, logic diagrams, and schematics, and the theory of operation of the control electronics are presented. Success in obtaining remote measurements of ozone profiles with an airborne systems is reported and results are analyzed.

The Ship Movement Trajectory Prediction Algorithm Using Navigational Data Fusion

PubMed Central

Borkowski, Piotr

2017-01-01

It is essential for the marine navigator conducting maneuvers of his ship at sea to know future positions of himself and target ships in a specific time span to effectively solve collision situations. This article presents an algorithm of ship movement trajectory prediction, which, through data fusion, takes into account measurements of the ship’s current position from a number of doubled autonomous devices. This increases the reliability and accuracy of prediction. The algorithm has been implemented in NAVDEC, a navigation decision support system and practically used on board ships. PMID:28632176

Response characteristic of high-speed on/off valve with double voltage driving circuit

NASA Astrophysics Data System (ADS)

Li, P. X.; Su, M.; Zhang, D. B.

2017-07-01

High-speed on/off valve, an important part of turbocharging system, its quick response has a direct impact on the turbocharger pressure cycle. The methods of improving the response characteristic of high speed on/off valve include increasing the magnetic force of armature and the voltage, decreasing the mass and current of coil. The less coil number of turns, the solenoid force is smaller. The special armature structure and the magnetic material will raise cost. In this paper a new scheme of double voltage driving circuit is investigated, in which the original driving circuit of high-speed on/off valve is replaced by double voltage driving circuit. The detailed theoretical analysis and simulations were carried out on the double voltage driving circuit, it showed that the switching time and delay time of the valve respectively are 3.3ms, 5.3ms, 1.9ms and 1.8ms. When it is driven by the double voltage driving circuit, the switching time and delay time of this valve are reduced, optimizing its response characteristic. By the comparison related factors (such as duty cycle or working frequency) about influences on response characteristic, the superior of double voltage driving circuit has been further confirmed.

Development of double-pair double difference location algorithm and its application to the regular earthquakes and non-volcanic tremors

NASA Astrophysics Data System (ADS)

Guo, H.; Zhang, H.

2016-12-01

Relocating high-precision earthquakes is a central task for monitoring earthquakes and studying the structure of earth's interior. The most popular location method is the event-pair double-difference (DD) relative location method, which uses the catalog and/or more accurate waveform cross-correlation (WCC) differential times from event pairs with small inter-event separations to the common stations to reduce the effect of the velocity uncertainties outside the source region. Similarly, Zhang et al. [2010] developed a station-pair DD location method which uses the differential times from common events to pairs of stations to reduce the effect of the velocity uncertainties near the source region, to relocate the non-volcanic tremors (NVT) beneath the San Andreas Fault (SAF). To utilize advantages of both DD location methods, we have proposed and developed a new double-pair DD location method to use the differential times from pairs of events to pairs of stations. The new method can remove the event origin time and station correction terms from the inversion system and cancel out the effects of the velocity uncertainties near and outside the source region simultaneously. We tested and applied the new method on the northern California regular earthquakes to validate its performance. In comparison, among three DD location methods, the new double-pair DD method can determine more accurate relative locations and the station-pair DD method can better improve the absolute locations. Thus, we further proposed a new location strategy combining station-pair and double-pair differential times to determine accurate absolute and relative locations at the same time. For NVTs, it is difficult to pick the first arrivals and derive the WCC event-pair differential times, thus the general practice is to measure station-pair envelope WCC differential times. However, station-pair tremor locations are scattered due to the low-precision relative locations. The ability that double-pair data can be directly constructed from the station-pair data means that double-pair DD method can be used for improving NVT locations. We have applied the new method to the NVTs beneath the SAF near Cholame, California. Compared to the previous results, the new double-pair DD tremor locations are more concentrated and show more detailed structures.

The Double Star Orbit Initial Value Problem

NASA Astrophysics Data System (ADS)

Hensley, Hagan

2018-04-01

Many precise algorithms exist to find a best-fit orbital solution for a double star system given a good enough initial value. Desmos is an online graphing calculator tool with extensive capabilities to support animations and defining functions. It can provide a useful visual means of analyzing double star data to arrive at a best guess approximation of the orbital solution. This is a necessary requirement before using a gradient-descent algorithm to find the best-fit orbital solution for a binary system.

The comparation of effects and security of double-J stent retention and ureteroscopy lithotripsy in the treatment of symptomatic ureteral calculi during pregnancy.

PubMed

Tan, Shu-Tao; Chen, Xiaonan; Sun, Ming; Wu, Bin

2018-06-01

To describe the efficacy of double-J stent retention and ureteroscopy lithotripsy, we performed a study to evaluate the management of symptomatic ureteral calculi during pregnancy. From January 2005 and June 2015, 53 pregnant women with symptomatic ureteral calculi were admitted and treated in our hospital. According to the treatment techniques, there were divided into two groups: double-J stent retention group (30 cases) and ureteroscopy lithotripsy group (23 cases). We collected the characteristics and treatment outcome of the patients. Double-J stent retention was performed on 30 patients. And the stents were successfully inserted in 25 patients (83.3%). 4 cases got complication in double-J group (16%). The mean operating time, medical cost and hospitalization time of double-J group were 20.6 min, 1632 yuan and 1.3 days. Ureteroscopy lithotripsy was performed on 23 patients. 20 patients were operated successfully (87.0%). 2 cases got complication in ureteroscopy group (10.0%). The mean operating time, medical cost and hospitalization time of ureteroscopy group were 41.5 min, 2792 yuan and 6.0 days. In summary, both double-J stent retention and ureteroscopy lithotripsy are effective and safe in the managation of ureteral calculi during pregnancy. Copyright © 2018 Elsevier B.V. All rights reserved.

Source Repeatability of Time-Lapse Offset VSP Surveys for Monitoring CO2 Injection

NASA Astrophysics Data System (ADS)

Zhang, Z.; Huang, L.; Rutledge, J. T.; Denli, H.; Zhang, H.; McPherson, B. J.; Grigg, R.

2009-12-01

Time-lapse vertical seismic profiling (VSP) surveys have the potential to remotely track the migration of injected CO2 within a geologic formation. To accurately detect small changes due to CO2 injection, the sources of time-lapse VSP surveys must be located exactly at the same positions. However, in practice, the source locations can vary from one survey to another survey. Our numerical simulations demonstrate that a variation of a few meters in the VSP source locations can result in significant changes in time-lapse seismograms. To address the source repeatability issue, we apply double-difference tomography to downgoing waves of time-lapse offset VSP data to invert for the source locations and the velocity structures simultaneously. In collaboration with Resolute Natural Resources, Navajo National Oil and Gas Company, and the Southwest Regional Partnership on Carbon Sequestration under the support of the U.S. Department of Energy’s National Energy Technology Laboratory, one baseline and two repeat offset VSP datasets were acquired in 2007-2009 for monitoring CO2 injection at the Aneth oil field in Utah. A cemented geophone string was used to acquire the data for one zero-offset and seven offset source locations. During the data acquisition, there was some uncertainty in the repeatability of the source locations relative to the baseline survey. Our double-difference tomography results of the Aneth time-lapse VSP data show that the source locations for different surveys are separated up to a few meters. Accounting for these source location variations during VSP data analysis will improve reliability of time-lapse VSP monitoring.

Adaptive changes in spatiotemporal gait characteristics in women during pregnancy.

PubMed

Błaszczyk, Janusz W; Opala-Berdzik, Agnieszka; Plewa, Michał

2016-01-01

Spatiotemporal gait cycle characteristics were assessed at early (P1), and late (P2) pregnancy, as well as at 2 months (PP1) and 6 months (PP2) postpartum. A substantial decrease in walking speed was observed throughout the pregnancy, with the slowest speed (1±0.2m/s) being during the third trimester. Walking at slower velocity resulted in complex adaptive adjustments to their spatiotemporal gait pattern, including a shorter step length and an increased duration of both their stance and double-support phases. Duration of the swing phase remained the least susceptible to changes. Habitual walking velocity (1.13±0.2m/s) and the optimal gait pattern were fully recovered 6 months after childbirth. Documented here adaptive changes in the preferred gait pattern seem to result mainly from the altered body anthropometry leading to temporary balance impairments. All the observed changes within stride cycle aimed to improve gait safety by focusing on its dynamic stability. The pregnant women preferred to walk at a slower velocity which allowed them to spend more time in double-support compared with their habitual pattern. Such changes provided pregnant women with a safer and more tentative ambulation that reduced the single-support period and, hence, the possibility of instability. As pregnancy progressed a significant increase in stance width and a decrease in step length was observed. Both factors allow also for gait stability improvement. Copyright © 2015 Elsevier B.V. All rights reserved.

A systematic review of the clinical performance of tooth-retained and implant-retained double crown prostheses with a follow-up of ≥ 3 years.

PubMed

Verma, Rohini; Joda, Tim; Brägger, Urs; Wittneben, Julia-Gabriela

2013-01-01

The objective of this review was to systematically screen the literature for data related to the survival and complication rates observed with dental or implant double crown abutments and removable prostheses under functional loading for at least 3 years. A systematic review of the dental literature from January 1966 to December 2009 was performed in electronic databases (PubMed and Embase) as well as by an extensive hand search to investigate the clinical outcomes of double crown reconstructions. From the total of 2412 titles retrieved from the search, 65 were selected for full-text review. Subsequently, 17 papers were included for data extraction. An estimation of the cumulative survival and complication rates was not feasible due to the lack of detailed information. Tooth survival rates for telescopic abutment teeth ranged from 82.5% to 96.5% after an observation period of 3.4 to 6 years, and for tooth-supported double crown retained dentures from 66.7% to 98.6% after an observation period of 6 to 10 years. The survival rates of implants were between 97.9% and 100% and for telescopic-retained removable dental prostheses with two mandibular implants, 100% after 3.0 and 10.4 years. The major biological complications affecting the tooth abutments were gingival inflammation, periodontal disease, and caries. The most frequent technical complications were loss of cementation and loss of facings. The main findings of this review are: (I) double crown tooth abutments and dentures demonstrated a wide range of survival rates. (II) Implant-supported mandibular overdentures demonstrated a favorable long-term prognosis. (III) A greater need for prosthetic maintenance is required for both tooth-supported and implant-supported reconstructions. (IV) Future areas of research would involve designing appropriate longitudinal studies for comparisons of survival and complication rates of different reconstruction designs. © 2012 by the American College of Prosthodontists.

Spatiotemporal Parameters are not Substantially Influenced by Load Carriage or Inclination During Treadmill and Overground Walking

PubMed Central

Seay, Joseph F.; Gregorczyk, Karen N.; Hasselquist, Leif

2016-01-01

Abstract Influences of load carriage and inclination on spatiotemporal parameters were examined during treadmill and overground walking. Ten soldiers walked on a treadmill and overground with three load conditions (00 kg, 20 kg, 40 kg) during level, uphill (6% grade) and downhill (-6% grade) inclinations at self-selected speed, which was constant across conditions. Mean values and standard deviations for double support percentage, stride length and a step rate were compared across conditions. Double support percentage increased with load and inclination change from uphill to level walking, with a 0.4% stance greater increase at the 20 kg condition compared to 00 kg. As inclination changed from uphill to downhill, the step rate increased more overground (4.3 ± 3.5 steps/min) than during treadmill walking (1.7 ± 2.3 steps/min). For the 40 kg condition, the standard deviations were larger than the 00 kg condition for both the step rate and double support percentage. There was no change between modes for step rate standard deviation. For overground compared to treadmill walking, standard deviation for stride length and double support percentage increased and decreased, respectively. Changes in the load of up to 40 kg, inclination of 6% grade away from the level (i.e., uphill or downhill) and mode (treadmill and overground) produced small, yet statistically significant changes in spatiotemporal parameters. Variability, as assessed by standard deviation, was not systematically lower during treadmill walking compared to overground walking. Due to the small magnitude of changes, treadmill walking appears to replicate the spatiotemporal parameters of overground walking. PMID:28149338

Is Virtual Surgical Planning in Orthognathic Surgery Faster Than Conventional Planning? A Time and Workflow Analysis of an Office-Based Workflow for Single- and Double-Jaw Surgery.

PubMed

Steinhuber, Thomas; Brunold, Silvia; Gärtner, Catherina; Offermanns, Vincent; Ulmer, Hanno; Ploder, Oliver

2018-02-01

The purpose of this study was to measure and compare the working time for virtual surgical planning (VSP) in orthognathic surgery in a largely office-based workflow in comparison with conventional surgical planning (CSP) regarding the type of surgery, staff involved, and working location. This prospective cohort study included patients treated with orthognathic surgery from May to December 2016. For each patient, both CSP with manual splint fabrication and VSP with fabrication of computer-aided design-computer-aided manufacturing splints were performed. The predictor variables were planning method (CSP or VSP) and type of surgery (single or double jaw), and the outcome was time. Descriptive and analytic statistics, including analysis of variance for repeated measures, were computed. The sample was composed of 40 patients (25 female and 15 male patients; mean age, 24.6 years) treated with single-jaw surgery (n = 18) or double-jaw surgery (n = 22). The mean times for planning single-jaw surgery were 145.5 ± 11.5 minutes for CSP and 109.3 ± 10.8 minutes for VSP, and those for planning double-jaw surgery were 224.1 ± 11.2 minutes and 149.6 ± 15.3 minutes, respectively. Besides the expected result that the working time was shorter for single-versus double-jaw surgery (P < .001), it was shown that VSP shortened the working time significantly versus CSP (P < .001). The reduction of time through VSP was relatively stronger for double-jaw surgery (P < .001 for interaction). All differences between CSP and VSP regarding profession (except for the surgeon's time investment) and location were statistically significant (P < .01). The surgeon's time to plan single-jaw surgery was 37.0 minutes for CSP and 41.2 minutes for VSP; for double-jaw surgery, it was 53.8 minutes and 53.6 minutes, respectively. Office-based VSP for orthognathic surgery was significantly faster for single- and double-jaw surgery. The time investment of the surgeon was equal for both methods, and all other steps of the workflow differed significantly compared with CSP. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

The Effect of Three Methods of Supporting the Double Bass on Muscle Tension.

ERIC Educational Resources Information Center

Dennis, Allan

1984-01-01

Using different methods of holding the double bass, college students performed Beethoven's Symphony No. 9. Audio recordings of performance were rated. Muscle tension readings from the left arm, right arm, upper back, and lower back were taken, using electromyography. Results suggest nonsignificant differences in both performance quality and muscle…

Total Maxillary Reconstruction With a Bi-Paddle Double-Barrel Osteocutaneous Fibular Flap and Arteriovenous Saphenous Loop After a Globe-Sparing Total Maxillectomy Due to Osteosarcoma.

PubMed

Tseng, Wan-Ling; Chang, Tzu-Yen; Hung, Kuo-Shu; Chen, Szu-Han; Hsiao, Jenn-Ren; Lee, Yao-Chou

2017-01-01

The titanium mesh or bone graft is usually used for orbital support after a globe-sparing total maxillectomy. However, its use can invite complications, such as infection, exposure, and absorption, especially for patients who require adjuvant radiotherapy. Here, the authors present a patient who received total maxillary reconstruction with an osteocutaneous fibular flap. A 53-year-old man with the diagnosis of maxillary osteosarcoma received a globe-sparing total maxillectomy. A bi-paddle double-barrel osteocutaneous fibular flap was used for orbital support, alveolar ridge recreation, and oro-sino-nasal separation. The short pedicle length inherent in the double-barrel design of the fibular flap was overcome by creating an arteriovenous saphenous loop. The postoperative recovery was uneventful. During the 9 months follow-up, the patient was tumor-free and satisfied with his appearance, speech, and intake functions. Reconstruction with a bi-paddle double-barrel osteocutaneous fibular flap after a globe-sparing total maxillectomy can achieve satisfactory aesthetic and functional results.

Extracorporeal Life Support Bridge to Ventricular Assist Device: The Double Bridge Strategy.

PubMed

Marasco, Silvana F; Lo, Casey; Murphy, Deirdre; Summerhayes, Robyn; Quayle, Margaret; Zimmet, Adam; Bailey, Michael

2016-01-01

In patients requiring left ventricular assist device (LVAD) support, it can be difficult to ascertain suitability for long-term mechanical support with LVAD and eventual transplantation. LVAD implantation in a shocked patient is associated with increased morbidity and mortality. Interest is growing in the utilization of extracorporeal life support (ECLS) as a bridge-to-bridge support for these critically unwell patients. Here, we reviewed our experience with ECLS double bridging. We hypothesized that ECLS double bridging would stabilize end-organ dysfunction and reduce ventricular assist device (VAD) implant perioperative mortality. We conducted a retrospective review of prospectively collected data for 58 consecutive patients implanted with a continuous-flow LVAD between January 2010 and December 2013 at The Alfred Hospital, Melbourne, Victoria, Australia. Twenty-three patients required ECLS support pre-LVAD while 35 patients underwent LVAD implantation without an ECLS bridge. Preoperative morbidity in the ECLS bridge group was reflected by increased postoperative intensive care duration, blood loss, blood product use, and postoperative renal failure, but without negative impact upon survival when compared with the no ECLS group. ECLS stabilization improved end-organ function pre-VAD implant with significant improvements in hepatic and renal dysfunction. This series demonstrates that the use of ECLS bridge to VAD stabilizes end-organ dysfunction and reduces VAD implant perioperative mortality from that traditionally reported in these "crash and burn" patients. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A time-resolved Langmuir double-probe method for the investigation of pulsed magnetron discharges

NASA Astrophysics Data System (ADS)

Welzel, Th.; Dunger, Th.; Kupfer, H.; Richter, F.

2004-12-01

Langmuir probes are important means for the characterization of plasma discharges. For measurements in plasmas used for the deposition of thin films, the Langmuir double probe is especially suited. With the increasing popularity of pulsed deposition discharges, there is also an increasing need for time-resolved characterization methods. For Langmuir probes, several single-probe approaches to time-resolved measurements are reported but very few for the double probe. We present a time-resolved Langmuir double-probe technique, which is applied to a pulsed magnetron discharge at several 100 kHz used for MgO deposition. The investigations show that a proper treatment of the current measurement is necessary to obtain reliable results. In doing so, a characteristic time dependence of the charge-carrier density during the "pulse on" time containing maximum values of almost 2•1011cm-3 was found. This characteristic time dependence varies with the pulse frequency and the duty cycle. A similar time dependence of the electron temperature is only observed when the probe is placed near the magnesium target.

Double-time correlation functions of two quantum operations in open systems

NASA Astrophysics Data System (ADS)

Ban, Masashi

2017-10-01

A double-time correlation function of arbitrary two quantum operations is studied for a nonstationary open quantum system which is in contact with a thermal reservoir. It includes a usual correlation function, a linear response function, and a weak value of an observable. Time evolution of the correlation function can be derived by means of the time-convolution and time-convolutionless projection operator techniques. For this purpose, a quasidensity operator accompanied by a fictitious field is introduced, which makes it possible to derive explicit formulas for calculating a double-time correlation function in the second-order approximation with respect to a system-reservoir interaction. The derived formula explicitly shows that the quantum regression theorem for calculating the double-time correlation function cannot be used if a thermal reservoir has a finite correlation time. Furthermore, the formula is applied for a pure dephasing process and a linear dissipative process. The quantum regression theorem and the the Leggett-Garg inequality are investigated for an open two-level system. The results are compared with those obtained by exact calculation to examine whether the formula is a good approximation.

Double lung point in an 18-month-old child: a case report and literature review

PubMed Central

2015-01-01

Objective Double lung point is a rare sign of pneumothorax in clinical practice. In this report I presented an 18-month-old child who presented with bilateral pneumothorax. Data synthesis and case presentation Ultrasonography examination revealed conventional lung point sign on the right and double lung point on the left side. Thoracentesis was attempted and closed thoracic drainage was performed on the right side, but no gas was drawn on the left side. Clinical implication of double lung point sign found in chest ultrasonography is that the size of pneumothorax is limited and conservative treatment is enough. Conclusions To the best of our knowledge, this is the first case of double lung point identified with ultrasonography in child. The strength of the case is that the double lung point sign is supported by computed tomography (CT). Furthermore, we propose that the presence of double lung point indicates limited pneumothorax and conservative management may well be attempted. PMID:25922750

The double slit experiment and the time reversed fire alarm

NASA Astrophysics Data System (ADS)

Halabi, Tarek

2011-03-01

When both slits of the double slit experiment are open, closing one paradoxically increases the detection rate at some points on the detection screen. Feynman famously warned that temptation to "understand" such a puzzling feature only draws us into blind alleys. Nevertheless, we gain insight into this feature by drawing an analogy between the double slit experiment and a time reversed fire alarm. Much as closing the slit increases probability of a future detection, ruling out fire drill scenarios, having heard the fire alarm, increases probability of a past fire (using Bayesian inference). Classically, Bayesian inference is associated with computing probabilities of past events. We therefore identify this feature of the double slit experiment with a time reversed thermodynamic arrow. We believe that much of the enigma of quantum mechanics is simply due to some variation of time's arrow.

The Howard Hughes Medical Institute cassette for storage phosphor plates

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

Staudenmann, J.; Zotterman, W.L.; Cook, D.W.

1994-03-01

New cassettes for 201 mm{times}252 mm (8{double_prime}{times}10{double_prime}) and 201 mm{times}400 mm (8{double_prime}{times}15.75{double_prime}) storage phosphor plates have been developed at the Synchrotron Resource of the Howard Hughes Medical Institute. The purpose for this work was mainly twofold. Firstly, to diminish the number of manual operations when putting the storage phosphor plate into the cassette or when extracting it from the cassette. Secondly, to render such a cassette much lighter than the former metal cassette previously in use. These two goals were achieved by making new cassettes that are operated as one piece instead of two or three independent parts as withmore » the former systems. The cassettes have been extensively tested and found to be very useful.« less

Social Context and Problem Factors among Youth with Juvenile Justice Involvement Histories.

PubMed

Voisin, Dexter R; Sales, Jessica M; Hong, Jun Sung; Jackson, Jerrold M; Rose, Eve S; DiClemente, Ralph J

2017-01-01

Youth with juvenile justice histories often reside in poorly resourced communities and report high rates of depression, gang involved networks, and STI-sexual related risk behaviors, compared to their counterparts. The primary aim of this study was to examine the relationship between social context (ie, a combined index score comprised of living in public housing, being a recipient of free school lunch, and witnessing community violence) and risk factors that are disproportionately worse for juvenile justice youth such as depression, gang involved networks and STI sexual risk behaviors. Data were collected from a sample of detained youth ages 14 to 16 (N = 489). Questions assessed demographics, social context, depression, gang-involved networks, and STI risk behaviors. Multiple logistic regression models, controlling for age, gender, race, school enrollment, and family social support, indicated that participants who reported poorer social context had double the odds of reporting being depressed; three times higher odds of being in a gang; three times higher odds of personally knowing a gang member; and double the odds of having engaged in STI-risk behaviors. These results provide significant information that can help service providers target certain profiles of youth with juvenile justice histories for early intervention initiatives.

The impact of using electronic patient records on practices of reading and writing.

PubMed

Laitinen, Heleena; Kaunonen, Marja; Åstedt-Kurki, Paivi

2014-12-01

The aim of this study was to investigate the use of electronic patient records in daily practice. In four wards of a large hospital district in Finland, N = 43 patients' care and activities were observed and analysed in terms of the Grounded Theory method. The findings revealed that using electronic patient records created a particular process of writing and reading. Wireless technology enabled simultaneous patient involvement and point-of-care documentation, additionally supporting real-time reading. Remote and retrospective documentation was distant in terms of both space and time. The remoteness caused double documentation, reduced accuracy and less-efficient use of time. 'Non-reading' practices were witnessed in retrospective reading, causing delays in patient care and increase in workload. Similarly, if documentation was insufficient or non-existent, the consequences were found to be detrimental to the patients. The use of an electronic patient record system has a significant impact on patient care. Therefore, it is crucial to develop wireless technology and interdisciplinary collaboration in order to improve and support high-quality patient care. © The Author(s) 2013.

Survival rates of teeth, implants, and double crown-retained removable dental prostheses: a systematic literature review.

PubMed

Koller, Beatrice; Att, Wael; Strub, Jorg-Rudolf

2011-01-01

The aim of this systematic literature review was to investigate the survival rates of teeth, implants, and double crown-retained removable dental prostheses (RDPs). A systematic review of the literature published from January 1973 through May 2010 was conducted using electronic databases and hand-searching to assess the clinical outcomes of teeth, implants, and double crown-retained RDPs. This review yielded 512 articles, which were narrowed down to 11. The included studies demonstrated tooth survival rates between 60.6% and 95.3% after an observation period of 4 to 10 years. The survival rates of RDPs supported by teeth ranged between 90.0% and 95.1% after 4 and 5.3 years, respectively. The survival rates of implants supporting prostheses in the mandible were between 97% and 100% after an observation period between 3 and 10.4 years. The survival rates of implant-retained RDPs in the mandible ranged between 95% and 100% after 9 and 10.4 years. Teeth and implants supporting prostheses in the maxilla, as well as the RDPs themselves, demonstrated a survival rate of 100% after 3.2 years. The current literature does not provide sufficient information regarding the long-term outcome of double crown-retained RDPs. Further studies based on a higher level of evidence are needed to validate the outcomes of this treatment modality.

Estimating crustal heterogeneity from double-difference tomography

USGS Publications Warehouse

Got, J.-L.; Monteiller, V.; Virieux, J.; Okubo, P.

2006-01-01

Seismic velocity parameters in limited, but heterogeneous volumes can be inferred using a double-difference tomographic algorithm, but to obtain meaningful results accuracy must be maintained at every step of the computation. MONTEILLER et al. (2005) have devised a double-difference tomographic algorithm that takes full advantage of the accuracy of cross-spectral time-delays of large correlated event sets. This algorithm performs an accurate computation of theoretical travel-time delays in heterogeneous media and applies a suitable inversion scheme based on optimization theory. When applied to Kilauea Volcano, in Hawaii, the double-difference tomography approach shows significant and coherent changes to the velocity model in the well-resolved volumes beneath the Kilauea caldera and the upper east rift. In this paper, we first compare the results obtained using MONTEILLER et al.'s algorithm with those obtained using the classic travel-time tomographic approach. Then, we evaluated the effect of using data series of different accuracies, such as handpicked arrival-time differences ("picking differences"), on the results produced by double-difference tomographic algorithms. We show that picking differences have a non-Gaussian probability density function (pdf). Using a hyperbolic secant pdf instead of a Gaussian pdf allows improvement of the double-difference tomographic result when using picking difference data. We completed our study by investigating the use of spatially discontinuous time-delay data. ?? Birkha??user Verlag, Basel, 2006.

Accuracy and reading time for six strategies using digital breast tomosynthesis in women with mammographically negative dense breasts.

PubMed

Tagliafico, Alberto Stefano; Calabrese, Massimo; Bignotti, Bianca; Signori, Alessio; Fisci, Erica; Rossi, Federica; Valdora, Francesca; Houssami, Nehmat

2017-12-01

To compare six strategies using digital breast tomosynthesis in women with mammographically negative dense breasts. This is a substudy of the 'ASTOUND' trial. 163 women who underwent tomosynthesis with synthetically reconstructed projection images (S-2D) inclusive of 13 (7.9%) cases diagnosed with breast cancer at histopathology after surgery were evaluated. Accuracy measures and screen-reading time of six reading strategies were assessed: (A) Single reading of S-2D alone, (B) single reading of tomosynthesis alone, (C) single reading of joint interpretation of tomosynthesis + S-2D, (D) double-reading of S-2D alone, (E) double reading of tomosynthesis alone, (F) double reading of joint interpretation of tomosynthesis + S-2D. The median age of the patients was 53 years (range, 36-88 years). The highest global accuracy was obtained with double reading of tomosynthesis + S2D (F) with an AUC of 0.979 (p<0.001) and a mean reading time of 154 s versus 34 s for the fastest strategy (single reading of S-2D alone). The AUCs for the other five strategies did not differ from each other. Double reading of tomosynthesis+ S2D had the best accuracy of six screen-reading strategies although it had the longest reading time. • Tomosynthesis acquisitions are progressively implemented with reconstructed synthesized 2D images • Double reading using S-2D plus tomosynthesis had the highest global accuracy (p<0.001). • Double reading of S-2D plus tomosynthesis increased reading time.

Time allocated to mathematics in post-primary schools in Ireland: are we in double trouble?

NASA Astrophysics Data System (ADS)

O'Meara, Niamh; Prendergast, Mark

2018-05-01

Mathematics educators and legislators worldwide have begun placing a greater emphasis on teaching mathematics for understanding and through the use of real-life applications. Revised curricula have led to the time allocated to mathematics in effected countries being scrutinised. This has resulted in policy-makers and educationalists worldwide calling for the inclusion of double class periods on the mathematics timetable. Research from the United States suggests that the introduction of double or block periods allow for the objectives of revised curricula to be realized. The aim of this study, which is set in the school context, is first to ascertain if schools in Ireland are scheduling double periods for mathematics at both lower post-primary level (Junior Cycle) and upper post-primary level (Senior Cycle). It also seeks to determine if there is a link between teachers' levels of satisfaction with the time allocated to mathematics and the provision of double periods and to get insights from teachers in relation to their opinions on what can be achieved through the introduction of such classes. Questionnaires were sent to 400 post-primary schools (approximately 1600 teachers) which were selected using stratified sampling techniques. It was found that 8.7% of mathematics teachers reported the provision of double periods at Junior Cycle while 55% reported that double periods were included on their timetable at Senior Cycle. The study also identified a link between teachers' levels of satisfaction with the time allocated to mathematics and the provision of double periods. Finally, teachers felt that double periods allowed for new teaching methodologies, which were promoted by the revised curricula, to be implemented and teaching for understanding was also more feasible. In essence, it was found that double periods have an influence on the mathematical experience of post-primary students as well as the teaching approaches employed.

New Technique for Barium Daughter Ion Identification in a Liquid Xe-136 Double Beta Decay Experiment

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

Fairbank, William

2016-06-08

This work addresses long-standing issues of fundamental interest in elementary particle physics. The most important outcome of this work is a new limit on neutrinoless double beta decay. This is an extremely rare and long-sought-after type of radioactive decay. If discovered, it would require changes in the standard model of the elementary constituents of matter, and would prove that neutrinos and antineutrinos are the same, a revolutionary concept in particle physics. Neutrinos are major components of the matter in the universe that are so small and so weakly interacting with other matter that their masses have not yet been discovered.more » A discovery of neutrinoless double beta decay could help determine the neutrino masses. An important outcome of the work on this project was the Colorado State University role in operating the EXO-200 neutrinoless double beta decay experiment and in analysis of the data from this experiment. One type of double beta decay of the isotope 136Xe, the two-neutrino variety, was discovered in this work. Although the other type of double beta decay, the neutrinoless variety, was not yet discovered in this work, a world’s best sensitivity of 1.9x10 25 year half-life was obtained. This result rules out a previous claim of a positive result in a different isotope. This work also establishes that the masses of the neutrinos are less than one millionth of that of electrons. A unique EXO-200 analysis, in which the CSU group had a leading role, has established for the first time ever in a liquid noble gas the fraction of daughter atoms from alpha and beta decay that are ionized. This result has important impact on other pending studies, including nucleon decay and barium tagging. Novel additional discoveries include multiphoton ionization of liquid xenon with UV pulsed lasers, which may find application in calibration of future noble liquid detectors, and studies of association and dissociation reactions of Ba + ions in gaseous xenon. Through this project, we are substantially closer to demonstrating “barium tagging”, i.e., detection of single daughter 136Ba atoms from 136Xe double beta decay. Milestones achieved include obtaining spectra of small numbers of Ba atoms and cryoprobe advances toward trapping single 136Ba atoms in solid xenon and probe extraction for detection. One of the other benefits to society is the training of six Ph.D. students in a variety of state-of-the-art technologies, half under primary support of this grant and half with partial support, with four finishing their Ph.D. degrees and two well on their way.« less

Photon induced non-linear quantized double layer charging in quaternary semiconducting quantum dots.

PubMed

Nair, Vishnu; Ananthoju, Balakrishna; Mohapatra, Jeotikanta; Aslam, M

2018-03-15

Room temperature quantized double layer charging was observed in 2 nm Cu 2 ZnSnS 4 (CZTS) quantum dots. In addition to this we observed a distinct non-linearity in the quantized double layer charging arising from UV light modulation of double layer. UV light irradiation resulted in a 26% increase in the integral capacitance at the semiconductor-dielectric (CZTS-oleylamine) interface of the quantum dot without any change in its core size suggesting that the cause be photocapacitive. The increasing charge separation at the semiconductor-dielectric interface due to highly stable and mobile photogenerated carriers cause larger electrostatic forces between the quantum dot and electrolyte leading to an enhanced double layer. This idea was supported by a decrease in the differential capacitance possible due to an enhanced double layer. Furthermore the UV illumination enhanced double layer gives us an AC excitation dependent differential double layer capacitance which confirms that the charging process is non-linear. This ultimately illustrates the utility of a colloidal quantum dot-electrolyte interface as a non-linear photocapacitor. Copyright © 2017 Elsevier Inc. All rights reserved.

Time-dependent density-functional theory with optimized effective potential and self-interaction correction and derivative discontinuity for the treatment of double ionization of He and Be atoms in intense laser fields

NASA Astrophysics Data System (ADS)

Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.

2013-05-01

We present a self-interaction-free time-dependent density-functional theory (TDDFT) for the treatment of double-ionization processes of many-electron systems. The method is based on the extension of the Krieger-Li-Iafrate (KLI) treatment of the optimized effective potential (OEP) theory and the incorporation of an explicit self-interaction correction (SIC) term. In the framework of the time-dependent density functional theory, we have performed three-dimensional (3D) calculations of double ionization of He and Be atoms by intense near-infrared laser fields. We make use of the exchange-correlation potential with the integer discontinuity which improves the description of the double-ionization process. We found that a proper description of the double ionization requires the TDDFT exchange-correlation potential with the discontinuity with respect to the variation of the total particle number (TPN). The results for the intensity-dependent rates of double ionization of He and Be atoms are presented.

Double-outlet right ventricle revisited.

PubMed

Ebadi, Ameneh; Spicer, Diane E; Backer, Carl L; Fricker, F Jay; Anderson, Robert H

2017-08-01

Double-outlet right ventricle is a form of ventriculoarterial connection. The definition formulated by the International Society for Nomenclature of Paediatric and Congenital Heart Disease is based on hearts with both arterial trunks supported in their greater part by a morphologically right ventricle. Bilateral infundibula and ventricular septal defects are highly debated criteria. This study examines the anatomic controversies surrounding double-outlet right ventricle. We show that hearts with double-outlet right ventricle can have atrioventricular-to-arterial valvular continuity. We emphasize the difference between the interventricular communication and the zone of deficient ventricular septation. The hearts examined were from the University of Florida in Gainesville; Johns Hopkins All Children's Hospital, St Petersburg, Fla; and Lurie Children's Hospital, Chicago, Ill. Each specimen had at least 75% of both arterial roots supported by the morphologically right ventricle, with a total of 100 hearts examined. The morphologic method was used to assess anatomic features, including arterial-atrioventricular valvular continuity, subarterial infundibular musculature, and the location of the hole between the ventricles. Most hearts had fibrous continuity between one of the arterial valves and an atrioventricular valve, with bilateral infundibula in 23%, and intact ventricular septum in 5%. Bilateral infundibula are not a defining feature of double-outlet right ventricle, representing only 23% of the specimens in our sample. The interventricular communication can have a posteroinferior muscular rim or extend to become perimembranous (58%). Double-outlet right ventricle can exist with an intact ventricular septum. Copyright © 2017 The American Association for Thoracic Surgery. All rights reserved.

Double versus single high-dose melphalan 200 mg/m2 and autologous stem cell transplantation for multiple myeloma: a region-based study in 484 patients from the Nordic area

PubMed Central

Björkstrand, Bo; Klausen, Tobias W.; Remes, Kari; Gruber, Astrid; Knudsen, Lene M.; Bergmann, Olav J.; Lenhoff, Stig; Johnsen, Hans E.

2009-01-01

Autologous stem cell transplantation is still considered the standard of care in young patients with multiple myeloma (MM). This disease is the most common indication for high-dose therapy (HDT) supported by hematopoietic stem cell transplantation and much data support the benefit of this procedure. Results of randomized studies are in favor of tandem autologous transplantation although the effect on overall survival is unclear. Based on sequential registration trials in the Nordic area, we aimed to evaluate the outcome of conventional single or double HDT. During 1994–2000 we registered a total of 484 previously untreated patients under the age of 60 years at diagnosis who on a regional basis initially were treated with single [Trial NMSG #5/94 and #7/98 (N=383)] or double [Trial Huddinge Karolinska Turku Herlev (N=101)] high-dose melphalan (200 mg/m2) therapy supported by autologous stem cell transplantation. A complete or very good partial response was achieved by 40% of patients in the single transplant group and 60% of patients in the double transplant group (p=0.0006). The probability of surviving progression free for five years after the diagnosis was 25% (95% CL 18–32%) in the singletransplant group and 46% (95% CL 33–55%) in the double transplant group (p=0.0014). The estimated overall five-year survival rate was 60% in the single transplant group and 64% in the doubletransplant (p=0.9). In a multivariate analysis of variables, including single versus double transplantation, β2 microglobulin level, age, sex and disease stage, only β2 microglobulin level was predictive for overall survival (p>0.0001) and progression free survival (p=0.001). In accordance with these results, a 1:1 case-control matched comparison between double and single transplantation did not identify significant differences in overall and progression free survival. In this retrospective analysis up front double transplantation with melphalan (200 mg/m2) as compared to single transplantation did not seem to improve the final outcome among patients in the Nordic area. These data are in accordance with recent publications from the Bologna 96 trial indicating that a second transplant should not be recommended up front as standard care.

Gait Pattern Alterations during Walking, Texting and Walking and Texting during Cognitively Distractive Tasks while Negotiating Common Pedestrian Obstacles

PubMed Central

Licence, Sammy; Smith, Robynne; McGuigan, Miranda P.; Earnest, Conrad P.

2015-01-01

Objectives Mobile phone texting is a common daily occurrence with a paucity of research examining corresponding gait characteristics. To date, most studies have participants walk in a straight line vs. overcoming barriers and obstacles that occur during regular walking. The aim of our study is to examine the effect of mobile phone texting during periods of cognitive distraction while walking and negotiating barriers synonymous with pedestrian traffic. Methods Thirty participants (18-50y) completed three randomized, counter-balanced walking tasks over a course during: (1) normal walking (control), (2) texting and walking, and (3) texting and walking whilst being cognitively distraction via a standard mathematical test performed while negotiating the obstacle course. We analyzed gait characteristics during course negotiation using a 3-dimensional motion analysis system and a general linear model and Dunnet-Hsu post-hoc procedure the normal walking condition to assess gait characteristic differences. Primary outcomes included the overall time to complete the course time and barrier contact. Secondary outcomes included obstacle clearance height, step frequency, step time, double support phase and lateral deviation. Results Participants took significantly longer (mean ± SD) to complete the course while texting (24.96±4.20 sec) and during cognitive distraction COG (24.09±3.36 sec) vs. normal walking (19.32±2.28 sec; all, P<0.001). No significant differences were noted for barrier contacts (P = 0.28). Step frequency, step time, double support phase and lateral deviation all increased in duration during the texting and cognitive distraction trial. Texting and being cognitively distracted also increased obstacle clearance versus the walking condition (all, P<0.02). Conclusions Texting while walking and/or being cognitively distracted significantly affect gait characteristics concordant to mobile phone usage resulting in a more cautious gate pattern. Future research should also examine a similar study in older participants who may be at a greater risk of tripping with such walking deviations. PMID:26222430

Quantitative Evaluation of Muscle Function, Gait, and Postural Control in People Experiencing Critical Illness After Discharge From the Intensive Care Unit.

PubMed

Kiriella, Jeevaka B; Araujo, Tamara; Vergara, Martin; Lopez-Hernandez, Laura; Cameron, Jill I; Herridge, Margaret; Gage, William H; Mathur, Sunita

2018-01-01

The path to recovery of muscle strength and mobility following discharge from the intensive care unit (ICU) has not been well described. The study objective was to quantify muscle function, gait, and postural control at 3 and 6 months after discharge in people who were recovering from critical illness and who were ventilated for 7 days or more. This was a nested longitudinal study with continuous inclusion of individuals over a 2-year period and with age- and sex-matched controls. Twenty-four people were tested at 3 months after ICU discharge; 16 of them (67%) were reevaluated at 6 months (post-ICU group). Healthy controls (n = 12) were tested at a single time point. Muscle function of the knee extensors (KEs), plantar flexors (PFs), and dorsiflexors (DFs) was assessed on a dynamometer. Gait was measured using an electronic walkway, and postural control was measured with 2 portable force plates. Muscle weakness was observed across all muscle groups at 3 months, with the greatest strength reductions in the ankle PFs (45%) and DFs (30%). Muscle power was reduced in the PFs and DFs but was not reduced in the KEs. Gait in the post-ICU group was characterized by a narrower step, longer stride, and longer double-support time than in the controls. Improvements were found in KE strength and in stride time and double-support time during gait at 6 months. Leg muscle strength and power had moderate associations with gait velocity, step width, and stride length (r = .44-.65). The small heterogeneous sample of people with a high level of function was a limitation of this study. Muscle strength and power were impaired at 6 months after ICU discharge and were associated with gait parameters. Future studies are needed to examine the role of muscle strength and power training in post-ICU rehabilitation programs to improve mobility. © 2017 American Physical Therapy Association

Mitigating the effects of charge noise and improving the coherence of a quantum dot hybrid qubit

NASA Astrophysics Data System (ADS)

Thorgrimsson, Brandur; Kim, Dohun; Yang, Yuan-Chi; Simmons, C. B.; Ward, Daniel R.; Foote, Ryan H.; Savage, D. E.; Lagally, M. G.; Friesen, Mark; Coppersmith, S. N.; Eriksson, M. A.

The quantum dot hybrid qubit, which can be viewed as a hybrid between a charge and spin qubit, is formed with three electrons in a double dot. The qubit is operated without any magnetic fields and exhibits both spin-qubit-like stability and charge-qubit-like speeds. Here we show that charge noise is the main source of decoherence for the hybrid qubit, and demonstrate that its effect can be mitigated in two ways: by modifying the qubit's internal parameters or by changing its operating regime. By combining these methods, we have increased a hybrid qubit's free induction decay time from 11 ns to 127 ns, and its Rabi decay time from 33 ns to over 1 μs. Additionally, we show that the longest Rabi decay times are not limited by fluctuations of the qubit energy but by fluctuations of the Rabi frequency (both of which arise from charge noise). This work was supported in part by ARO (W911NF-12-0607) and by NSF (DMR-1206915 and PHY-1104660). Development and maintenance of the growth facilities used for fabricating samples was supported by DOE (DE-FG02-03ER46028). This research utilized NSF-supported shared facilities at the University of Wisconsin-Madison.

A prospective comparison of performance during back-to-back, anterograde manual spiral enteroscopy and double-balloon enteroscopy.

PubMed

Despott, Edward J; Murino, Alberto; Bourikas, Leonidas; Nakamura, Masanao; Ramachandra, Vino; Fraser, Chris

2015-05-01

Spiral enteroscopy is a recently introduced technology alternative to balloon-assisted enteroscopy for examination of the small bowel. To compare small bowel insertion depths and procedure duration by spiral enteroscopy and double-balloon enteroscopy performed in the same cohort of patients, in immediate succession, using the same method of insertion depth estimation. A prospective, back-to-back comparative study was performed in 15 patients. Spiral enteroscopy procedures were performed first and a tattoo was placed to mark the most distal point. Double-balloon enteroscopy passed the tattoo placed at spiral enteroscopy in 14/15 cases (93%). Median insertion depths for double-balloon enteroscopy and spiral enteroscopy were 265cm and 175cm, respectively (P=0.004). Median time to achieve maximal depth of insertion was significantly shorter for spiral enteroscopy compared with double-balloon enteroscopy (24min vs. 45min, respectively; P=0.0005). However, in 14 patients no differences were found in median time to reach the same insertion depth (P=0.28). Double-balloon enteroscopy achieved significantly greater small bowel insertion depth than spiral enteroscopy. Although overall double-balloon enteroscopy procedure duration was longer, the time taken to reach the same small bowel insertion depth by both spiral enteroscopy and double-balloon enteroscopy was similar. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Quantitative Gait Markers and Incident Fall Risk in Older Adults

PubMed Central

Holtzer, Roee; Lipton, Richard B.; Wang, Cuiling

2009-01-01

Background Identifying quantitative gait markers of falls in older adults may improve diagnostic assessments and suggest novel intervention targets. Methods We studied 597 adults aged 70 and older (mean age 80.5 years, 62% women) enrolled in an aging study who received quantitative gait assessments at baseline. Association of speed and six other gait markers (cadence, stride length, swing, double support, stride length variability, and swing time variability) with incident fall rate was studied using generalized estimation equation procedures adjusted for age, sex, education, falls, chronic illnesses, medications, cognition, disability as well as traditional clinical tests of gait and balance. Results Over a mean follow-up period of 20 months, 226 (38%) of the 597 participants fell. Mean fall rate was 0.44 per person-year. Slower gait speed (risk ratio [RR] per 10 cm/s decrease 1.069, 95% confidence interval [CI] 1.001–1.142) was associated with higher risk of falls in the fully adjusted models. Among six other markers, worse performance on swing (RR 1.406, 95% CI 1.027–1.926), double-support phase (RR 1.165, 95% CI 1.026–1.321), swing time variability (RR 1.007, 95% CI 1.004–1.010), and stride length variability (RR 1.076, 95% CI 1.030–1.111) predicted fall risk. The associations remained significant even after accounting for cognitive impairment and disability. Conclusions Quantitative gait markers are independent predictors of falls in older adults. Gait speed and other markers, especially variability, should be further studied to improve current fall risk assessments and to develop new interventions. PMID:19349593

Comparative analysis of human gait while wearing thong-style flip-flops versus sneakers.

PubMed

Shroyer, Justin F; Weimar, Wendi H

2010-01-01

Flip-flops are becoming a common footwear option. Casual observation has indicated that individuals wear flip-flops beyond their structural limit and have a different gait while wearing flip-flops versus shoes. This alteration in gait may cause the anecdotal foot and lower-limb discomfort associated with wearing flip-flops. To investigate the effect of sneakers versus thong-style flip-flops on gait kinematics and kinetics, 56 individuals (37 women and 19 men) were randomly assigned to a footwear order (flip-flops or sneakers first) and were asked to wear the assigned footwear on the day before and the day of testing. On each testing day, participants were videotaped as they walked at a self-selected pace across a force platform. A 2 (sex) x 2 (footwear) repeated-measures analysis of variance (P = .05) was used for statistical analysis. Significant interaction effects of footwear and sex were found for maximal anterior force, attack angle, and ankle angle during the swing phase. Footwear significantly affected stride length, ankle angle at the beginning of double support and during the swing phase, maximal braking impulse, and stance time. Flip-flops resulted in a shorter stride, a larger ankle angle at the beginning of double support and during the swing phase, a smaller braking impulse, and a shorter stance time compared with sneakers. The effects of footwear on gait kinetics and kinematics is extensive, but there is limited research on the effect of thong-style flip-flops on gait. These results suggest that flip-flops have an effect on several kinetic and kinematic variables compared with sneakers.

Age-related changes in gait adaptability in response to unpredictable obstacles and stepping targets.

PubMed

Caetano, Maria Joana D; Lord, Stephen R; Schoene, Daniel; Pelicioni, Paulo H S; Sturnieks, Daina L; Menant, Jasmine C

2016-05-01

A large proportion of falls in older people occur when walking. Limitations in gait adaptability might contribute to tripping; a frequently reported cause of falls in this group. To evaluate age-related changes in gait adaptability in response to obstacles or stepping targets presented at short notice, i.e.: approximately two steps ahead. Fifty older adults (aged 74±7 years; 34 females) and 21 young adults (aged 26±4 years; 12 females) completed 3 usual gait speed (baseline) trials. They then completed the following randomly presented gait adaptability trials: obstacle avoidance, short stepping target, long stepping target and no target/obstacle (3 trials of each). Compared with the young, the older adults slowed significantly in no target/obstacle trials compared with the baseline trials. They took more steps and spent more time in double support while approaching the obstacle and stepping targets, demonstrated poorer stepping accuracy and made more stepping errors (failed to hit the stepping targets/avoid the obstacle). The older adults also reduced velocity of the two preceding steps and shortened the previous step in the long stepping target condition and in the obstacle avoidance condition. Compared with their younger counterparts, the older adults exhibited a more conservative adaptation strategy characterised by slow, short and multiple steps with longer time in double support. Even so, they demonstrated poorer stepping accuracy and made more stepping errors. This reduced gait adaptability may place older adults at increased risk of falling when negotiating unexpected hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Multimodal Freight Distribution to Support Increased Port Operations

DOT National Transportation Integrated Search

2016-10-01

To support improved port operations, three different aspects of multimodal freight distribution are investigated: (i) Efficient load planning for double stack trains at inland ports; (ii) Optimization of a multimodal network for environmental sustain...

Design of the forward straw tube tracker for the PANDA experiment

NASA Astrophysics Data System (ADS)

Smyrski, J.; Apostolou, A.; Biernat, J.; Czyżycki, W.; Filo, G.; Fioravanti, E.; Fiutowski, T.; Gianotti, P.; Idzik, M.; Korcyl, G.; Korcyl, K.; Lisowski, E.; Lisowski, F.; Płażek, J.; Przyborowski, D.; Przygoda, W.; Ritman, J.; Salabura, P.; Savrie, M.; Strzempek, P.; Swientek, K.; Wintz, P.; Wrońska, A.

2017-06-01

The design of the Forward Tracker for the Forward Spectrometer of the PANDA experiment is described. The tracker consists of 6 tracking stations, each comprising 4 planar double layers of straw tube detectors, and has a total material budget of only 2% X0. The straws are made self-supporting by a 1 bar over-pressure of the working gas mixture (Ar/CO2). This allows to use lightweight and compact rectangular support frames for the double layers and to split the frames into pairs of C-shaped half-frames for an easier installation on the beam line.

Doubling the number of physics majors who teach

NASA Astrophysics Data System (ADS)

Marder, Michael

2009-03-01

The American Physical Society has adopted a doubling initiative to increase the number of physics majors. One of the main motivations is to increase the number of physics majors certified to teach secondary physics. I will review some of the possible strategies for reaching this goal, and discuss some of the steps we have taken with UTeach, the program for secondary science and mathematics teacher preparation at The University of Texas at Austin.I will discuss the roles of curriculum revision, financial support, and community support in convincing majors to teach. Finally, I will talk about the expansion of UTeach into engineering.

Comparison of Clinical Efficacy of Lateral and Lateral and Medial Double-plating Fixation of Distal Femoral Fractures.

PubMed

Bai, Zhibiao; Gao, Shichang; Hu, Zhenming; Liang, Anlin

2018-03-20

The present study was performed to compare the clinical efficacy of lateral plate and lateral and medial double-plating fixation of distal femoral fractures and explore the indication of lateral and medial double-plating fixation of the distal femoral fractures. From March 2006 to April 2014, 48 and 12 cases of distal femoral fractures were treated with lateral plate (single plate) and lateral and medial plates (double plates), respectively. During the surgery, after setting the lateral plate for the distal femoral fractures, if the varus stress test of the knee was positive and the lateral collateral ligament rupture was excluded, lateral and medial double-plating fixation was used for the stability of the fragments. All the patients were followed up at an average period of 15.9 months. The average operation time, the intraoperative hemorrhage and the fracture union time of the two groups were compared. One year after operation, knee function was evaluated by the Kolmert's standard. There was no significant difference in the average operation time, intraoperative hemorrhage, fracture healing time and excellent and good rates of postoperative knee function between two groups. Positive Varus stress test during operation can be an indication for lateral and medial double-plating fixation of distal femoral fractures.

Speech Recognition Using Neural Nets and Dynamic Time Warping

DTIC Science & Technology

1988-12-01

flost tmap [~J20J0[16J; mnt r, Ci: double diet ; double minimum =99M9.9; for (r =0; r < fysize ; ri-i-){ for (c =0; c f xeize ; c+ +){ diet 6 .0; for...i)[1] = (location[iflO] 0); Lmindist (I map, inp, close) double inp[16J; mrt close [2] float tmap [20(201[161 double diet ; double minimum 9.99e31

Sequential Double lonization: The Timing of Release

NASA Astrophysics Data System (ADS)

Pfeiffer, A.

2011-05-01

The timing of electron release in strong field double ionization poses great challenges both for conceptual definition and for conducting experimental measurement. Here we present coincidence momentum measurements of the doubly charged ion and of the two electrons arising from double ionization of Argon using elliptically (close to circularly) polarized laser pulses. Based on a semi-classical model, the ionization times are calculated from the measured electron momenta across a large intensity range. Exploiting the attoclock technique we have direct access to timings on a coarse and on a fine scale, similar to the hour and the minute hand of a clock. In our attoclock, the magnitude of the electron momenta follows the envelope of the laser pulse and gives a coarse timing for the electron releases (the hour hand), while the fine timing (the minute hand) is provided by the emission angle of the electrons. The first of our findings is that due to depletion the averaged ionization time moves towards the beginning of the pulse with increasing intensity, confirming the results of Maharjan et al., and that the ion momentum distribution projected onto the minor polarization axis shows a bifurcation from a 3-peak to a 4-peak structure. This effect can be fully understood by modeling the process semi-classically in the independent electron approximation following the simple man's model. The ionization time measurement performed with the attoclock shows that the release time of the first electron is in good agreement with the semi-classical simulation performed on the basis of Sequential Double lonization (SDI), whereas the ionization of the second electron occurs significantly earlier than predicted. This observation suggests that electron correlation and other Non-Sequential Double lonization (NSDI) mechanisms may play an important role also in the case of strong field double ionization by close-to-circularly polarized laser pulses. The timing of electron release in strong field double ionization poses great challenges both for conceptual definition and for conducting experimental measurement. Here we present coincidence momentum measurements of the doubly charged ion and of the two electrons arising from double ionization of Argon using elliptically (close to circularly) polarized laser pulses. Based on a semi-classical model, the ionization times are calculated from the measured electron momenta across a large intensity range. Exploiting the attoclock technique we have direct access to timings on a coarse and on a fine scale, similar to the hour and the minute hand of a clock. In our attoclock, the magnitude of the electron momenta follows the envelope of the laser pulse and gives a coarse timing for the electron releases (the hour hand), while the fine timing (the minute hand) is provided by the emission angle of the electrons. The first of our findings is that due to depletion the averaged ionization time moves towards the beginning of the pulse with increasing intensity, confirming the results of Maharjan et al., and that the ion momentum distribution projected onto the minor polarization axis shows a bifurcation from a 3-peak to a 4-peak structure. This effect can be fully understood by modeling the process semi-classically in the independent electron approximation following the simple man's model. The ionization time measurement performed with the attoclock shows that the release time of the first electron is in good agreement with the semi-classical simulation performed on the basis of Sequential Double lonization (SDI), whereas the ionization of the second electron occurs significantly earlier than predicted. This observation suggests that electron correlation and other Non-Sequential Double lonization (NSDI) mechanisms may play an important role also in the case of strong field double ionization by close-to-circularly polarized laser pulses. In collaboration with C. Cirelli and M. Smolarski, Physics Department, ETH Zurich, 8093 Zurich, Switzerland; R. Doerner, Institut fiir Kernphysik, Johann Wolfgang Goethe Universitat, 60438 Frankfurt am Main, Germany; and U. Keller, ETH Zurich.

Critical fluctuations near the pitchfork bifurcations of period-doubling maps

NASA Astrophysics Data System (ADS)

Noble, Andrew; Karimeddiny, Saba; Hastings, Alan; Machta, Jonathan

2015-03-01

Period-doubling maps, such as the logistic map, have been a subject of intense study in both physics and biology. The period-doubling route to chaos proceeds through a sequence of supercritical pitchfork bifurcations. Here, motivated by applications to population ecology, we investigate the asymptotic behavior of period-doubling bifurcations subject to environmental or demographic noise. We demonstrate, analytically, that fluctuations in the vicinity of each noisy pitchfork bifurcation are described by finite-size mean-field theory. Our results establish an exact correspondence between the bifurcations of far-from-equilibrium systems and the mean-field critical phenomena of equilibrium systems. This material is based upon work supported by the National Science Foundation under INSPIRE Grant No. 1344187.

Coulomb double helical structure

NASA Astrophysics Data System (ADS)

Kamimura, Tetsuo; Ishihara, Osamu

2012-01-01

Structures of Coulomb clusters formed by dust particles in a plasma are studied by numerical simulation. Our study reveals the presence of various types of self-organized structures of a cluster confined in a prolate spheroidal electrostatic potential. The stable configurations depend on a prolateness parameter for the confining potential as well as on the number of dust particles in a cluster. One-dimensional string, two-dimensional zigzag structure and three-dimensional double helical structure are found as a result of the transition controlled by the prolateness parameter. The formation of stable double helical structures resulted from the transition associated with the instability of angular perturbations on double strings. Analytical perturbation study supports the findings of numerical simulations.

A Portable Double-Slit Quantum Eraser with Individual Photons

ERIC Educational Resources Information Center

Dimitrova, T. L.; Weis, A.

2011-01-01

The double-slit experiment has played an important role in physics, from supporting the wave theory of light, via the discussions of the wave-particle duality of light (and matter) to the foundations of modern quantum optics. Today it keeps playing an active role in the context of quantum optics experiments involving single photons. In this paper,…

Dual-cone double-helical downhole logging device

DOEpatents

Yu, Jiunn S.

1984-01-01

A broadband downhole logging device includes a double-helix coil wrapped over a dielectric support and surrounded by a dielectric shield. The device may also include a second coil longitudinally aligned with a first coil and enclosed within the same shield for measuring magnetic permeability of downhole formations and six additional coils for accurately determining downhole parameters.

The Mechanism of Viral Replication. Structure of Replication Complexes of Encephalomyocarditis Virus

PubMed Central

Thach, Sigrid S.; Dobbertin, Darrell; Lawrence, Charles; Golini, Fred; Thach, Robert E.

1974-01-01

The structure of the purified replicative intermediate of encephalomyocarditis virus was determined by electron microscopy. Approximately 80% of the replicative intermediate complexes were characterized by a filament of double-stranded RNA of widely variable length, which had a “bush” of single-stranded RNA at one end. In many examples one or more additional single-stranded bushes were appended internally to the double-stranded RNA filament. These results support the view that before deproteinization, replicative intermediate contains little if any double-stranded RNA. Images PMID:4366773

The influence of age on gait parameters during the transition from a wide to a narrow pathway.

PubMed

Shkuratova, Nataliya; Taylor, Nicholas

2008-06-01

The ability to negotiate pathways of different widths is a prerequisite of daily living. However, only a few studies have investigated changes in gait parameters in response to walking on narrow pathways. The aim of this study is to examine the influence of age on gait adjustments during the transition from a wide to a narrow pathway. Two-group repeated measures design. Gait Laboratory. Twenty healthy older participants (mean [M] = 74.3 years, Standard deviation [SD] = 7.2 years); 20 healthy young participants (M = 26.6 years, SD = 6.1 years). Making the transition from walking on a wide pathway (68 cm) to walking on a narrow pathway (15 cm). Step length, step time, step width, double support time and base of support. Healthy older participants were able to make the transition from a wide to a narrow pathway successfully. There was only one significant interaction, between age and base of support (p < 0.003). Older adults decreased their base of support only when negotiating the transition step, while young participants started decreasing their base of support prior to the negotiation of transition step (p < 0.01). Adjustments to the transition from a wide to a narrow pathway are largely unaffected by normal ageing. Difficulties in making the transition to a narrow pathway during walking should not be attributed to normal age-related changes. (c) 2008 John Wiley & Sons, Ltd.

Multi-dimensional stable fundamental solitons and excitations in PT-symmetric harmonic-Gaussian potentials with unbounded gain-and-loss distributions

NASA Astrophysics Data System (ADS)

Chen, Yong; Yan, Zhenya

2018-04-01

We demonstrate the parity-time- (PT-) symmetric harmonic-Gaussian potential with unbounded gain-and-loss distribution can support entirely-real linear spectra, stable spatial and spatio-temporal solitons in an inhomogeneous nonlinear medium (e.g., cubic nonlinear Schrödinger equation with the self-focusing and defocusing cases). Exact analytical solitons are derived in both one-dimensional (1D) and higher-dimensional (e.g., 2D, 3D) geometries such that they are verified to be stable in the given parameters regions. Particularly, several families of numerical fundamental solitons (especially the 1D double-peaked solitons, 2D vortex solitons, and 3D double bullets) can be found to be stable around the propagation parameters for exact solitons. Other significant properties of solitons are also explored including the interactions of solitons, stable soliton excitations, and transverse power flows. The results may excite the corresponding theoretical analysis and experiment designs.

Design options for improving protective gloves for industrial assembly work.

PubMed

Dianat, Iman; Haslegrave, Christine M; Stedmon, Alex W

2014-07-01

The study investigated the effects of wearing two new designs of cotton glove on several hand performance capabilities and compared them against the effects of barehanded, single-layered and double cotton glove conditions when working with hand tools (screwdriver and pliers). The new glove designs were based on the findings of subjective hand discomfort assessments for this type of work and aimed to match the glove thickness to the localised pressure and sensitivity in different areas of the hand as well as to provide adequate dexterity for fine manipulative tasks. The results showed that the first prototype glove and the barehanded condition were comparable and provided better dexterity and higher handgrip strength than double thickness gloves. The results support the hypothesis that selective thickness in different areas of the hand could be applied by glove manufacturers to improve the glove design, so that it can protect the hands from the environment and at the same time allow optimal hand performance capabilities. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Cognitive, psychomotor, and subjective effects of sodium oxybate and triazolam in healthy volunteers

PubMed Central

Carter, Lawrence P.; Griffiths, Roland R.; Mintzer, Miriam Z.

2009-01-01

Rationale Illicit gamma-hydroxybutyrate (GHB) has received attention as a “date rape drug” that produces robust amnesia; however, there is little experimental evidence in support of GHB’s amnestic effects. Objectives This study compared the cognitive effects of GHB (sodium oxybate) with those of triazolam in healthy volunteers. Materials and methods Doses of sodium oxybate (1.125, 2.25, and 4.5 g/70 kg), triazolam (0.125, 0.25, and 0.5 mg/70 kg), and placebo were administered to 15 volunteers under repeated measures, counterbalanced, double-blind, double-dummy conditions. The time course and peak physiological, psychomotor, subjective, and cognitive effects were examined. Results Sodium oxybate and triazolam produced similar increases in participant ratings of drug effects. Performance on psychomotor, working memory, and episodic memory tasks was impaired to a greater extent after triazolam than sodium oxybate. Conclusions Together, these data suggest that sodium oxybate produces less psychomotor and cognitive impairment than triazolam at doses that produce equivalent participant-rated subjective effects in healthy volunteers. PMID:19543883

Complete transposition of the great arteries with double outlet right ventricle in a dog.

PubMed

Koo, S T; LeBlanc, N L; Scollan, K F; Sisson, D D

2016-06-01

A 2-year old intact male Collie dog presented to the cardiology service at Oregon State University for evaluation of cyanosis and suspected congenital cardiac disease. Echocardiography revealed a constellation of cardiac abnormalities including a single large vessel exiting the right ventricle with a diminutive left ventricular outflow tract, a ventricular septal defect, and marked concentric right ventricular hypertrophy with moderate right atrial dilation. Cardiac-gated computed tomography confirmed the previous anomalies in addition to supporting a diagnosis of complete transposition of the great arteries, double outlet right ventricle, and pulmonic hypoplasia with a single coronary ostium. Prominent bronchoesophageal collateral vessels were concurrently identified. Clinically, the dog was stable despite mild cyanosis that worsened with exercise; no intervention was elected at the time. This case report describes a rare combination of congenital cardiac defects and the usefulness of cardiac-gated cross-sectional imaging in the anatomic diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

A silk sericin/silicone nerve guidance conduit promotes regeneration of a transected sciatic nerve.

PubMed

Xie, Hongjian; Yang, Wen; Chen, Jianghai; Zhang, Jinxiang; Lu, Xiaochen; Zhao, Xiaobo; Huang, Kun; Li, Huili; Chang, Panpan; Wang, Zheng; Wang, Lin

2015-10-28

Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long-term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up-regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone-double-conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Double anisotropic electrically conductive flexible Janus-typed membranes.

PubMed

Li, Xiaobing; Ma, Qianli; Tian, Jiao; Xi, Xue; Li, Dan; Dong, Xiangting; Yu, Wensheng; Wang, Xinlu; Wang, Jinxian; Liu, Guixia

2017-12-07

Novel type III anisotropic conductive films (ACFs), namely flexible Janus-typed membranes, were proposed, designed and fabricated for the first time. Flexible Janus-typed membranes composed of ordered Janus nanobelts were constructed by electrospinning, which simultaneously possess fluorescence and double electrically conductive anisotropy. For the fabrication of the Janus-typed membrane, Janus nanobelts comprising a conductive side and an insulative-fluorescent side were primarily fabricated, and then the Janus nanobelts are arranged into parallel arrays using an aluminum rotary drum as the collector to obtain a single anisotropically conductive film. Subsequently, a secondary electrospinning process was applied to the as-prepared single anisotropically conductive films to acquire the final Janus-typed membrane. For this Janus-typed membrane, namely its left-to-right structure, anisotropic electrical conduction synchronously exists on both sides, and furthermore, the two electrically conductive directions are perpendicular. By modulating the amount of Eu(BA) 3 phen complex and conducting polyaniline (PANI), the characteristics and intensity of the fluorescence-electricity dual-function in the membrane can be tuned. The high integration of this peculiar Janus-typed membrane with simultaneous double electrically conductive anisotropy-fluorescent dual-functionality is successfully realized in this study. This design philosophy and preparative technique will provide support for the design and construction of new types of special nanostructures with multi-functionality.

Glassy dielectric response in Tb2NiMnO6 double perovskite with similarities to a Griffiths phase

NASA Astrophysics Data System (ADS)

Nhalil, Hariharan; Nair, Harikrishnan S.; Bhat, H. L.; Elizabeth, Suja

2013-12-01

Results of frequency-dependent and temperature-dependent dielectric measurements performed on the double-perovskite Tb2NiMnO6 are presented. The real (\\epsilon_1 (f,T)) and imaginary (\\epsilon_2 (f,T)) parts of dielectric permittivity show three plateaus suggesting dielectric relaxation originating from the bulk, grain boundaries and the sample-electrode interfaces, respectively. The \\epsilon_1 (f,T) and \\epsilon_2 (f,T) are successfully simulated by a RC circuit model. The complex plane of impedance, Z'\\text{-}Z'' , is simulated using a series network with a resistor R and a constant phase element. Through the analysis of \\epsilon (f,T) using the modified Debye model, two different relaxation time regimes separated by a characteristic temperature, T^* , are identified. The temperature variation of R and C corresponding to the bulk and the parameter α from modified Debye fit lend support to this hypothesis. Interestingly, the T^* compares with the Griffiths temperature for this compound observed in magnetic measurements. Though these results cannot be interpreted as magnetoelectric coupling, the relationship between lattice and magnetism is markedly clear. We assume that the observed features have their origin in the polar nanoregions which originate from the inherent cationic defect structure of double perovskites.

Profile of an individual supporting member

NASA Astrophysics Data System (ADS)

During the past 2 years, the number of Individual Supporting Members in AGU has more than doubled. This increase in interest is primarily due to the AGU-GIFT program and its efforts to seek the voluntary support of all members. Your response has been encouraging, and we believe the number can be doubled again in the next 18 months.Who is the typical Individual Supporting Member? The first step in the development of a “profile” was to find the age pattern. The eldest was born in 1892—Congratulations on your 90th year!—and the youngest in 1948. One would hardly expect to find a Gaussian distribution. In fact there was no evidence of a “peak,” but 50% were born between 1910 and 1930—with the median age being 62—just beginning to harvest the fruits of senior citizenship. For comparison, the median age for the total membership of AGU is 42.

Inverse problem of the vibrational band gap of periodically supported beam

NASA Astrophysics Data System (ADS)

Shi, Xiaona; Shu, Haisheng; Dong, Fuzhen; Zhao, Lei

2017-04-01

The researches of periodic structures have a long history with the main contents confined in the field of forward problem. In this paper, the inverse problem is considered and an overall frame is proposed which includes two main stages, i.e., the band gap criterion and its optimization. As a preliminary investigation, the inverse problem of the flexural vibrational band gap of a periodically supported beam is analyzed. According to existing knowledge of its forward problem, the band gap criterion is given in implicit form. Then, two cases with three independent parameters, namely the double supported case and the triple one, are studied in detail and the explicit expressions of the feasible domain are constructed by numerical fitting. Finally, the parameter optimization of the double supported case with three variables is conducted using genetic algorithm aiming for the best mean attenuation within specified frequency band.

Compressive and rarefactive double layers in non-uniform plasma with q-nonextensive distributed electrons

NASA Astrophysics Data System (ADS)

Shan, S. Ali; Saleem, H.

2018-05-01

Electrostatic solitary waves and double layers (DLs) formed by the coupled ion acoustic (IA) and drift waves have been investigated in non-uniform plasma using q-nonextensive distribution function for the electrons and assuming ions to be cold Ti< Te. It is found that both compressive and rarefactive nonlinear structures (solitary waves and DLs) are possible in such a system. The steeper gradients are supportive for compressive solitary (and double layers) and destructive for rarefactive ones. The q-nonextensivity parameter q and the magnitudes of gradient scale lengths of density and temperature have significant effects on the amplitude of the double layers (and double layers) as well as on the speed of these structures. This theoretical model is general which has been applied here to the F-region ionosphere for illustration.

Age-related changes in the center of mass velocity control during walking.

PubMed

Chong, Raymond K Y; Chastan, Nathalie; Welter, Marie-Laure; Do, Manh-Cuong

2009-07-10

During walking, the body center of mass oscillates along the vertical plane. Its displacement is highest at mid-swing and lowest at terminal swing during the transition to double support. Its vertical velocity (CoMv) has been observed to increase as the center of mass falls between mid- and late swing but is reduced just before double support. This suggests that braking of the center of mass is achieved with active neural control. We tested whether this active control deteriorates with aging (Experiment 1) and during a concurrent cognitive task (Experiment 2). At short steps of <0.4m, CoMv control was low and similar among all age groups. All groups braked the CoMv at longer steps of >0.4m but older subjects did so to a lesser extent. During the cognitive task, young subjects increased CoMv control (i.e. increase in CoMv braking) while maintaining step length and walking speed. Older subjects on the other hand, did not increase CoMv control but rather maintain it by reducing both step length and walking speed. These results suggest that active braking of the CoM during the transition to double support predominates in steps >0.4m. It could be a manifestation of the balance control system, since the braking occurs at late stance where body weight is being shifted to the contralateral side. The active braking mechanism also appears to require some attentional resource. In aging, reducing step length and speed are strategic to maintaining effective center of mass control during the transition to double support. However, the lesser degree of control in older adults indicates a true age-related deficit.

Cost as a technology driver. [in aerospace R and D

NASA Technical Reports Server (NTRS)

Fitzgerald, P. E., Jr.; Savage, M.

1976-01-01

Cost managment as a guiding factor in optimum development of technology, and proper timing of cost-saving programs in the development of a system or technology with payoffs in development and operational advances are discussed and illustrated. Advances enhancing the performance of hardware or software advances raising productivity or reducing cost, are outlined, with examples drawn from: thermochemical thrust maximization, development of cryogenic storage tanks, improvements in fuel cells for Space Shuttle, design of a spacecraft pyrotechnic initiator, cost cutting by reduction in the number of parts to be joined, and cost cutting by dramatic reductions in circuit component number with small-scale double-diffused integrated circuitry. Program-focused supporting research and technology models are devised to aid judicious timing of cost-conscious research programs.

The Role of Adaptation in Body Load-Regulating Mechanisms During Locomotion

NASA Technical Reports Server (NTRS)

Ruttley, Tara; Holt, Christopher; Mulavara, Ajitkumar; Bloomberg, Jacob

2010-01-01

Body loading is a fundamental parameter that modulates motor output during locomotion, and is especially important for controlling the generation of stepping patterns, dynamic balance, and termination of locomotion. Load receptors that regulate and control posture and stance in locomotion include the Golgi tendon organs and muscle spindles at the hip, knee, and ankle joints, and the Ruffini endings and the Pacinian corpuscles in the soles of the feet. Increased body weight support (BWS) during locomotion results in an immediate reorganization of locomotor control, such as a reduction in stance and double support duration and decreased hip, ankle, and knee angles during the gait cycle. Previous studies on the effect during exposure to increased BWS while walking showed a reduction in lower limb joint angles and gait cycle timing that represents a reorganization of locomotor control. Until now, no studies have investigated how locomotor control responds after a period of exposure to adaptive modification in the body load sensing system. The goal of this research was to determine the adaptive properties of body load-regulating mechanisms in locomotor control during locomotion. We hypothesized that body load-regulating mechanisms contribute to locomotor control, and adaptive changes in these load-regulating mechanisms require reorganization to maintain forward locomotion. Head-torso coordination, lower limb movement patterns, and gait cycle timing were evaluated before and after a 30-minute adaptation session during which subjects walked on a treadmill at 5.4 km/hr with 40% body weight support (BWS). Before and after the adaptation period, head-torso and lower limb 3D kinematic data were obtained while performing a goal directed task during locomotion with 0% BWS using a video-based motion analysis system, and gait cycle timing parameters were collected by foot switches positioned under the heel and toe of the subjects shoes. Subjects showed adaptive modification in the body load-regulating mechanisms that included increased head movement amplitude, increased knee and ankle flexion, and increased stance, stride, and double support time, with no change in the performance of the task with respect to that measured before exposure to BWS. These changes in locomotor control are opposite to that reported during 40% BWS exposure and indicative of an after-effect after removal of the adaptive stimulus. Therefore, it is evident that just 30 minutes of 40% BWS during locomotion was sufficient to induce adaptive modifications in the body load sensing systems that contribute to reorganization of sensory contributions to stable locomotor control.

Probing the Circumstellar Disks of Be Stars with Contemporaneous Optical and IR Spectroscopy

NASA Astrophysics Data System (ADS)

Bjorkman, Karen S.; Hesselbach, E. N.; Wisniewski, J. P.; Bjorkman, J. E.

2006-12-01

Asymmetric double-peaked hydrogen emission line profiles in classical Be stars have been interpreted as evidence of one-armed density waves in the circumstellar disks. Contemporaneous optical and IR spectroscopy can aid in mapping the density structure of these one-armed waves as a function of radius. Furthermore, variability has been detected in these stars over both short (days to weeks) and longer (months) time-scales. We present preliminary results from contemporaneous Ritter Observatory (Hα) and IRTF SpeX (0.8-5.4 μm) spectroscopy of 16 classical Be stars observed in September 2005 and January 2006. The data illustrate a range of line profiles common in Be stars and show significant variability. These observations are the first of a larger project to utilize combined optical and IR data to investigate the physical details of these circumstellar disks. This research has been supported in part by a NASA GSRP fellowship to JPW, a NASA LTSA grant to KSB, and an NSF grant to JEB. We thank the NASA IRTF for observing time allocations and support. We thank the Ritter observing team, and especially Nancy Morrison, for crucial assistance with the supporting optical observations.

Should drivers be operating within an automation-free bandwidth? Evaluating haptic steering support systems with different levels of authority.

PubMed

Petermeijer, Sebastiaan M; Abbink, David A; de Winter, Joost C F

2015-02-01

The aim of this study was to compare continuous versus bandwidth haptic steering guidance in terms of lane-keeping behavior, aftereffects, and satisfaction. An important human factors question is whether operators should be supported continuously or only when tolerance limits are exceeded. We aimed to clarify this issue for haptic steering guidance by investigating costs and benefits of both approaches in a driving simulator. Thirty-two participants drove five trials, each with a different level of haptic support: no guidance (Manual); guidance outside a 0.5-m bandwidth (Band1); a hysteresis version of Band1, which guided back to the lane center once triggered (Band2); continuous guidance (Cont); and Cont with double feedback gain (ContS). Participants performed a reaction time task while driving. Toward the end of each trial, the guidance was unexpectedly disabled to investigate aftereffects. All four guidance systems prevented large lateral errors (>0.7 m). Cont and especially ContS yielded smaller lateral errors and higher time to line crossing than Manual, Band1, and Band2. Cont and ContS yielded short-lasting aftereffects, whereas Band1 and Band2 did not. Cont yielded higher self-reported satisfaction and faster reaction times than Band1. Continuous and bandwidth guidance both prevent large driver errors. Continuous guidance yields improved performance and satisfaction over bandwidth guidance at the cost of aftereffects and variability in driver torque (indicating human-automation conflicts). The presented results are useful for designers of haptic guidance systems and support critical thinking about the costs and benefits of automation support systems.

Neuropsychological Training of Attention Improves MS-Related Fatigue: Results of a Randomized, Placebo-Controlled, Double-Blind Pilot Study.

PubMed

Flachenecker, Peter; Meissner, Heike; Frey, Rebecca; Guldin, Wolfgang

2017-01-01

Attentional deficits may be pathophysiologically relevant in MS-associated fatigue. Thirty MS patients with fatigue and attentional deficits in neuropsychological testing participated in this randomized, placebo-controlled, double-blind trial. The intervention group (IG; n = 14) was treated with 10 h of computerized, specific neuropsychological training performing simple reaction time tasks, whereas the control group (CG; n = 16) also runs through computerized, but unspecific neuropsychological training using tasks without time components. The subjective feeling of fatigue was assessed with the Würzburg Fatigue Inventory for Multiple Sclerosis (WEIMuS) questionnaire, and testing of alertness was used as an objective measure at baseline and after the 2-week study period. Reaction times of alertness were significantly decreased in IG but not CG after 2 weeks. The subjective feeling of fatigue was ameliorated in both groups but more pronounced in IG. Effect sizes were below 0.7 for alertness and WEIMuS scores in CG but large and clinically meaningful in IG for both measures. Our pilot study suggests that neuropsychological training of attention may improve both measures of fatigue. The parallel improvement of attentional deficits and subjective fatigue after specific neuropsychological training support previous findings that fatigue may be at least partially caused by impaired intensity of attention. © 2017 S. Karger AG, Basel.

Predictive implications of Gompertz's law

NASA Astrophysics Data System (ADS)

Richmond, Peter; Roehner, Bertrand M.

2016-04-01

Gompertz's law tells us that for humans above the age of 35 the death rate increases exponentially with a doubling time of about 10 years. Here, we show that the same law continues to hold up to age 106. At that age the death rate is about 50%. Beyond 106 there is so far no convincing statistical evidence available because the number of survivors are too small even in large nations. However, assuming that Gompertz's law continues to hold beyond 106, we conclude that the mortality rate becomes equal to 1 at age 120 (meaning that there are 1000 deaths in a population of one thousand). In other words, the upper bound of human life is near 120. The existence of this fixed-point has interesting implications. It allows us to predict the form of the relationship between death rates at age 35 and the doubling time of Gompertz's law. In order to test this prediction, we first carry out a transversal analysis for a sample of countries comprising both industrialized and developing nations. As further confirmation, we also develop a longitudinal analysis using historical data over a time period of almost two centuries. Another prediction arising from this fixed-point model, is that, above a given population threshold, the lifespan of the oldest persons is independent of the size of their national community. This prediction is also supported by empirical evidence.

15. The second story in the north segment of the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. The second story in the north segment of the building was originally constructed as a restaurant. The north wall of the dining room retains the original wood wainscot and double-hung windows. At some undetermined time, a building was constructed on the adjacent property; blocking the windows in the dining room. Several chimneys with stove-pipe connections occur in the room. The members seen on the floor are part of a system recently installed to support the failing roof. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

Timing of head movements is consistent with energy minimization in walking ungulates

PubMed Central

Loscher, David M.; Meyer, Fiete; Kracht, Kerstin

2016-01-01

Many ungulates show a conspicuous nodding motion of the head when walking. Until now, the functional significance of this behaviour remained unclear. Combining in vivo kinematics of quadrupedal mammals with a computer model, we show that the timing of vertical displacements of the head and neck is consistent with minimizing energy expenditure for carrying these body parts in an inverted pendulum walking gait. Varying the timing of head movements in the model resulted in increased metabolic cost estimate for carrying the head and neck of up to 63%. Oscillations of the head–neck unit result in weight force oscillations transmitted to the forelimbs. Advantageous timing increases the load in single support phases, in which redirecting the trajectory of the centre of mass (COM) is thought to be energetically inexpensive. During double support, in which—according to collision mechanics—directional changes of the impulse of the COM are expensive, the observed timing decreases the load. Because the head and neck comprise approximately 10% of body mass, the effect shown here should also affect the animals' overall energy expenditure. This mechanism, working analogously in high-tech backpacks for energy-saving load carriage, is widespread in ungulates, and provides insight into how animals economize locomotion. PMID:27903873

Translations from Kommunist, Number 8, June 1977

DTIC Science & Technology

1977-08-16

of the assignments of the 10th Five-Year Plan, which we have no doubt will be achieved, will 10 enable us to double the country’s industrial...resolved the problem of doubling the volume of trade. Now we are going farther, seeking to triple it. Judging from the results of the past two...equipment. Within that time the capital-labor ratio in agriculture rose 2.5 times; its power-labor ratio more than doubled , while electric power

Influence of the charge double layer on solid oxide fuel cell stack behavior

NASA Astrophysics Data System (ADS)

Whiston, Michael M.; Bilec, Melissa M.; Schaefer, Laura A.

2015-10-01

While the charge double layer effect has traditionally been characterized as a millisecond phenomenon, longer timescales may be possible under certain operating conditions. This study simulates the dynamic response of a previously developed solid oxide fuel cell (SOFC) stack model that incorporates the charge double layer via an equivalent circuit. The model is simulated under step load changes. Baseline conditions are first defined, followed by consideration of minor and major deviations from the baseline case. This study also investigates the behavior of the SOFC stack with a relatively large double layer capacitance value, as well as operation of the SOFC stack under proportional-integral (PI) control. Results indicate that the presence of the charge double layer influences the SOFC stack's settling time significantly under the following conditions: (i) activation and concentration polarizations are significantly increased, or (ii) a large value of the double layer capacitance is assumed. Under normal (baseline) operation, on the other hand, the charge double layer effect diminishes within milliseconds, as expected. It seems reasonable, then, to neglect the charge double layer under normal operation. However, careful consideration should be given to potential variations in operation or material properties that may give rise to longer electrochemical settling times.

The Double ABCX Model of Adaptation in Racially Diverse Families with a School-Age Child with Autism

ERIC Educational Resources Information Center

Manning, Margaret M.; Wainwright, Laurel; Bennett, Jillian

2011-01-01

In this study, the Double ABCX model of family adaptation was used to explore the impact of severity of autism symptoms, behavior problems, social support, religious coping, and reframing, on outcomes related to family functioning and parental distress. The sample included self-report measures collected from 195 families raising school-age…

Family Quality of Life and Psychological Well-Being in Parents of Children with Autism Spectrum Disorders: A Double ABCX Model

ERIC Educational Resources Information Center

Pozo, P.; Sarriá, E.; Brioso, A.

2014-01-01

Background: This study examined family quality of life (FQOL) and psychological well-being from a multidimensional perspective. The proposed model was based on the double ABCX model, with severity of the disorder, behaviour problems, social support, sense of coherence (SOC) and coping strategies as components. Method: One hundred and eighteen…

Frustration by competing interactions in the highly-distorted double perovskites La2NaRuO6 and La2NaOsO6

NASA Astrophysics Data System (ADS)

Aczel, A. A.; Bugaris, D. E.; Li, L.; Yan, J.-Q.; de La Cruz, C.; Zur Loye, H.-C.; Nagler, S. E.

2013-03-01

The usual classical behavior of S = 3/2, B-site ordered double perovskites results in simple, commensurate magnetic ground states. In contrast, heat capacity and neutron powder diffraction measurements for the S = 3/2 systems La2NaB'O6 (B' = Ru, Os) reveal an incommensurate magnetic ground state for La2NaRuO6 and a drastically suppressed ordered moment for La2NaOsO6. This behavior is attributed to the large monoclinic structural distortions of these double perovskites. The distortions have the effect of weakening the nearest neighbor superexchange interactions, presumably to an energy scale that is comparable to the next nearest neighbor superexchange. The exotic ground states in these materials can then arise from a competition between these two types of antiferromagnetic interactions, providing a novel mechanism for achieving frustration in the double perovskite family. Work at ORNL is supported by the Division of Scientific User Facilities and the Materials Science and Engineering Division, DOE Basic Energy Sciences. Work at the University of South Carolina is supported by the Heterogeneous Functional Materials Research Center, funded by DOE under award number de-sc0001061.

Layered double hydroxide supported gold nanoclusters by glutathione-capped Au nanoclusters precursor method for highly efficient aerobic oxidation of alcohols

NASA Astrophysics Data System (ADS)

Li, Lun; Dou, Liguang; Zhang, Hui

2014-03-01

M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h-1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h-1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen. Electronic supplementary information (ESI) available: Details in experimental and further characterization. See DOI: 10.1039/c3nr05604j

Double Reformatsky reaction: divergent synthesis of δ-hydroxy-β-ketoesters.

PubMed

Mineno, Masahiro; Sawai, Yasuhiro; Kanno, Kazuaki; Sawada, Naotaka; Mizufune, Hideya

2013-06-21

The double Reformatsky reaction, tandem addition of two molecules of zinc alkanoate to a carbonyl compound, and its synthetic application to a series of δ-hydroxy-β-ketoesters has been developed. The key to accelerate the double Reformatsky reaction is considered to be a complex-induced proximity effect of the in situ generated zinc alkoxide coordinated with the pyridyl group of the substrate or bidentate amines. A noteworthy feature of the reaction system is its high tolerance of functional groups due to the moderate nucleophilicity of organozinc reagents and the mild reaction conditions. Moreover, spectroscopic and crystallographic analyses of the zinc complex of the double Reformatsky product support the proposed mechanism of reaction site discrimination for ketones, aldehydes, nitriles, carboxylic acid anhydrides, and esters.

Polymer system for gettering hydrogen

DOEpatents

Shepodd, Timothy Jon; Whinnery, LeRoy L.

2000-01-01

A novel composition comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen.

Polymer formulations for gettering hydrogen

DOEpatents

Shepodd, Timothy Jon; Whinnery, LeRoy L.

1998-11-17

A novel composition comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen.

Accuracy of the lattice-Boltzmann method using the Cell processor

NASA Astrophysics Data System (ADS)

Harvey, M. J.; de Fabritiis, G.; Giupponi, G.

2008-11-01

Accelerator processors like the new Cell processor are extending the traditional platforms for scientific computation, allowing orders of magnitude more floating-point operations per second (flops) compared to standard central processing units. However, they currently lack double-precision support and support for some IEEE 754 capabilities. In this work, we develop a lattice-Boltzmann (LB) code to run on the Cell processor and test the accuracy of this lattice method on this platform. We run tests for different flow topologies, boundary conditions, and Reynolds numbers in the range Re=6 350 . In one case, simulation results show a reduced mass and momentum conservation compared to an equivalent double-precision LB implementation. All other cases demonstrate the utility of the Cell processor for fluid dynamics simulations. Benchmarks on two Cell-based platforms are performed, the Sony Playstation3 and the QS20/QS21 IBM blade, obtaining a speed-up factor of 7 and 21, respectively, compared to the original PC version of the code, and a conservative sustained performance of 28 gigaflops per single Cell processor. Our results suggest that choice of IEEE 754 rounding mode is possibly as important as double-precision support for this specific scientific application.

Single chip camera device having double sampling operation

NASA Technical Reports Server (NTRS)

Fossum, Eric R. (Inventor); Nixon, Robert (Inventor)

2002-01-01

A single chip camera device is formed on a single substrate including an image acquisition portion for control portion and the timing circuit formed on the substrate. The timing circuit also controls the photoreceptors in a double sampling mode in which are reset level is first read and then after an integration time a charged level is read.

Cartilage formation in the CELLS 'double bubble' hardware

NASA Technical Reports Server (NTRS)

Duke, P. J.; Arizpe, Jorge; Montufar-Solis, Dina

1991-01-01

The CELLS experiment scheduled to be flown on the first International Microgravity Laboratory is designed to study the effect of microgravity on the cartilage formation, by measuring parameters of growth in a differentiating cartilage cell culture. This paper investigates the conditions for this experiment by studying cartilage differentiation in the 'bubble exchange' hardware with the 'double bubble' design in which the bubbles are joined by a flange which also overlays the gasket. Four types of double bubbles (or double gas permeable membranes) were tested: injection-molded bubbles 0.01- and 0.005-in. thick, and compression molded bubbles 0.015- and 0.01-in. thick. It was found that double bubble membranes of 0.005- and 0.010-in. thickness supported cartilage differentiation, while the 0.015-in. bubbles did not. It was also found that nodule count, used in this study as a parameter, is not the best measure of the amount of cartilage differentiation.

Routine Microsecond Molecular Dynamics Simulations with AMBER on GPUs. 1. Generalized Born

PubMed Central

2012-01-01

We present an implementation of generalized Born implicit solvent all-atom classical molecular dynamics (MD) within the AMBER program package that runs entirely on CUDA enabled NVIDIA graphics processing units (GPUs). We discuss the algorithms that are used to exploit the processing power of the GPUs and show the performance that can be achieved in comparison to simulations on conventional CPU clusters. The implementation supports three different precision models in which the contributions to the forces are calculated in single precision floating point arithmetic but accumulated in double precision (SPDP), or everything is computed in single precision (SPSP) or double precision (DPDP). In addition to performance, we have focused on understanding the implications of the different precision models on the outcome of implicit solvent MD simulations. We show results for a range of tests including the accuracy of single point force evaluations and energy conservation as well as structural properties pertainining to protein dynamics. The numerical noise due to rounding errors within the SPSP precision model is sufficiently large to lead to an accumulation of errors which can result in unphysical trajectories for long time scale simulations. We recommend the use of the mixed-precision SPDP model since the numerical results obtained are comparable with those of the full double precision DPDP model and the reference double precision CPU implementation but at significantly reduced computational cost. Our implementation provides performance for GB simulations on a single desktop that is on par with, and in some cases exceeds, that of traditional supercomputers. PMID:22582031

Density-Functional Theory with Optimized Effective Potential and Self-Interaction Correction for the Double Ionization of He and Be Atoms

NASA Astrophysics Data System (ADS)

Heslar, John; Telnov, Dmitry; Chu, Shih-I.

2012-06-01

We present a self-interaction-free (SIC) time-dependent density-functional theory (TDDFT) for the treatment of double ionization processes of many-electron systems. The method is based on the Krieger-Li-Iafrate (KLI) treatment of the optimized effective potential (OEP) theory and the incorporation of an explicit self-interaction correction (SIC) term. In the framework of the time-dependent density functional theory, we have performed 3D calculations of double ionization of He and Be atoms by strong near-infrared laser fields. We make use of the exchange-correlation potential with the integer discontinuity which improves the description of the double ionization process. We found that proper description of the double ionization requires the TDDFT exchange-correlation potential with the discontinuity with respect to the variation of the spin particle numbers (SPN) only. The results for the intensity-dependent probabilities of single and double ionization are presented and reproduce the famous ``knee'' structure.

Prognosis of Combining Remaining Teeth and Implants in Double-Crown-Retained Removable Dental Prostheses: A Systematic Review and Meta-Analysis.

PubMed

Lian, Meifei; Zhao, Kai; Feng, Yunzhi; Yao, Qian

The reliability of combining natural teeth and implants in one removable prosthesis is controversial. This systematic review was conducted to evaluate the prognosis of combined tooth/implant-supported double-crown-retained removable dental prostheses (DCR-RDPs) and to compare them with solely implant-supported prostheses with a minimum observation period of 3 years. Electronic database (PubMed, Embase, Central, and SCI) and manual searches up to August 2016 were conducted to identify human clinical studies on tooth/implant-supported DCR-RDPs. Literature selection and data extraction were accomplished by two independent reviewers. Meta-analyses of survival and complication rates were performed separately for combined tooth/implant-supported and solely implant-supported DCRRDPs. Among the initially identified 366 articles, 17 were included in a quantitative analysis. The estimated overall cumulative survival rate (CSR) for implants in combined tooth/implant-supported DCRRDPs was 98.72% (95% confidence interval [95% CI]: 96.98% to 99.82%), and that for implants in solely implant-supported DCR-RDPs was 98.83% (95% CI: 97.45% to 99.75%). The summary CSR for abutment teeth was 92.96% (95% CI: 85.38% to 98.12%). Double-crown-retained dentures with both abutment types showed high CSRs, most of which were approximately 100%. Regarding prosthetic maintenance treatment, the estimated incidence for patients treated with combined tooth/implant-supported RDPs was 0.164 (95% CI: 0.089 to 0.305) per patient per year (T/P/Y) and that for patients restored with solely implant-supported RDPs was 0.260 (95% CI: 0.149 to 0.454) T/P/Y. Based on four studies with combined tooth/implant-supported DCR-RDPs, no intrusion phenomena were encountered. Subject to the limitations of the present review, combining remaining teeth and implants in DCR-RDPs is a reliable and predictable treatment modality for partially edentulous patients. Comparable high survival rates and minor biologic or technical complications are observed for combined tooth/implant-supported and solely implant-supported DCR-RDPs. Due to the heterogeneity of the included studies, the results must be interpreted with caution.

DNA concentration modulation on supported lipid bilayers switched by surface acoustic waves.

PubMed

Hennig, Martin; Wolff, Manuel; Neumann, Jürgen; Wixforth, Achim; Schneider, Matthias F; Rädler, Joachim O

2011-12-20

Spatially addressable arrays of molecules embedded in or anchored to supported lipid bilayers are important for on-chip screening and binding assays; however, methods to sort or accumulate components in a fluid membrane on demand are still limited. Here we apply in-plane surface acoustic shear waves (SAWs) to laterally accumulate double-stranded DNA segments electrostatically bound to a cationic supported lipid bilayer. The fluorescently labeled DNA segments are found to segregate into stripe patterns with a spatial frequency corresponding to the periodicity of the standing SAW wave (~10 μm). The DNA molecules are accumulated 10-fold in the regions of SAW antinodes. The superposition of two orthogonal sets of SAW sources creates checkerboard like arrays of DNA demonstrating the potential to generate arrayed fields dynamically. The pattern relaxation time of 0.58 s, which is independent of the segment length, indicates a sorting and relaxation mechanism dominated by lipid diffusion rather than DNA self-diffusion. © 2011 American Chemical Society

Doubling Up When Times Are Tough: A Study of Obligations to Share a Home in Response to Economic Hardship

PubMed Central

Seltzer, Judith A.; Lau, Charles Q.; Bianchi, Suzanne M.

2012-01-01

This study uses a factorial vignette design embedded in an Internet survey to investigate attitudes toward an adult child and parent living together in response to economic hardship. Over half of Americans said the desirability of intergenerational co-residence depends on particularistic aspects of the family, notably the quality of family relationships. Support for co-residence is greatest when the adult child is single rather than partnered. Support is weaker if the adult child is cohabiting rather than married to the partner, although groups with greater exposure to cohabitation make less of a distinction between cohabitation and marriage. Presence of a grandchild does not affect views about co-residence. There is more support for sharing a home when a mother needs a place to live than when the adult child does. Responses to open-ended questions show that individuals invoke both universalistic family obligations and particularistic qualities of family relationships to explain their attitudes. PMID:23017934

The role of DNA double-strand breaks in spontaneous homologous recombination in S. cerevisiae.

PubMed

Lettier, Gaëlle; Feng, Qi; de Mayolo, Adriana Antúnez; Erdeniz, Naz; Reid, Robert J D; Lisby, Michael; Mortensen, Uffe H; Rothstein, Rodney

2006-11-10

Homologous recombination (HR) is a source of genomic instability and the loss of heterozygosity in mitotic cells. Since these events pose a severe health risk, it is important to understand the molecular events that cause spontaneous HR. In eukaryotes, high levels of HR are a normal feature of meiosis and result from the induction of a large number of DNA double-strand breaks (DSBs). By analogy, it is generally believed that the rare spontaneous mitotic HR events are due to repair of DNA DSBs that accidentally occur during mitotic growth. Here we provide the first direct evidence that most spontaneous mitotic HR in Saccharomyces cerevisiae is initiated by DNA lesions other than DSBs. Specifically, we describe a class of rad52 mutants that are fully proficient in inter- and intra-chromosomal mitotic HR, yet at the same time fail to repair DNA DSBs. The conclusions are drawn from genetic analyses, evaluation of the consequences of DSB repair failure at the DNA level, and examination of the cellular re-localization of Rad51 and mutant Rad52 proteins after introduction of specific DSBs. In further support of our conclusions, we show that, as in wild-type strains, UV-irradiation induces HR in these rad52 mutants, supporting the view that DNA nicks and single-stranded gaps, rather than DSBs, are major sources of spontaneous HR in mitotic yeast cells.

A Randomized, Double-Blind, Crossover Comparison of MK-0929 and Placebo in the Treatment of Adults with ADHD

ERIC Educational Resources Information Center

Rivkin, Anna; Alexander, Robert C.; Knighton, Jennifer; Hutson, Pete H.; Wang, Xiaojing J.; Snavely, Duane B.; Rosah, Thomas; Watt, Alan P.; Reimherr, Fred W.; Adler, Lenard A.

2012-01-01

Objective: Preclinical models, receptor localization, and genetic linkage data support the role of D4 receptors in the etiology of ADHD. This proof-of-concept study was designed to evaluate MK-0929, a selective D4 receptor antagonist as treatment for adult ADHD. Method: A randomized, double-blind, placebo-controlled, crossover study was conducted…

Fear of falling and gait parameters in older adults with and without fall history.

PubMed

Makino, Keitaro; Makizako, Hyuma; Doi, Takehiko; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao; Shimada, Hiroyuki

2017-12-01

Fear of falling (FOF) is associated with spatial and temporal gait parameters in older adults. FOF is prevalent among older adults, both those with and without fall history. It is still unclear whether the relationships between FOF and gait parameters are affected by fall history. The aim of the present study was to compare gait parameters by the presence of FOF and fall history. A total of 3575 older adults (mean age 71.7 years, 49.7% female) met the inclusion criteria for the present study. We assessed the presence of fall history and FOF by face-to-face interview, and gait parameters (gait speed, stride length, step rate, double support time and variation of stride length) at a comfortable speed using a computerized electronic walkway. Prevalences of fall history and FOF were as follows: non-fallers without FOF 52.6% (n = 1881); fallers without FOF 6.3% (n = 227); non-fallers with FOF 34.4% (n = 1229); and fallers with FOF 6.7% (n = 238). Analysis of covariance showed significant differences among the four groups in all gait variables even after adjusting for age, sex and number of medications used. It should be noted that non-fallers with FOF showed significantly slower gait speed, shorter stride length and longer double support time than did non-fallers without FOF (P < 0.001). The present results suggest that spatial and temporal gait parameters are influenced by FOF, even in the absence of fall history. The assessment of FOF might be helpful for better understanding of age-related changes in gait control. Geriatr Gerontol Int 2017; 17: 2455-2459. © 2017 Japan Geriatrics Society.

The oscillatory behavior of the CoM facilitates mechanical energy balance between push-off and heel strike.

PubMed

Kim, Seyoung; Park, Sukyung

2012-01-10

Humans use equal push-off and heel strike work during the double support phase to minimize the mechanical work done on the center of mass (CoM) during the gait. Recently, a step-to-step transition was reported to occur over a period of time greater than that of the double support phase, which brings into question whether the energetic optimality is sensitive to the definition of the step-to-step transition. To answer this question, the ground reaction forces (GRFs) of seven normal human subjects walking at four different speeds (1.1-2.4 m/s) were measured, and the push-off and heel strike work for three differently defined step-to-step transitions were computed based on the force, work, and velocity. To examine the optimality of the work and the impulse data, a hybrid theoretical-empirical analysis is presented using a dynamic walking model that allows finite time for step-to-step transitions and incorporates the effects of gravity within this period. The changes in the work and impulse were examined parametrically across a range of speeds. The results showed that the push-off work on the CoM was well balanced by the heel strike work for all three definitions of the step-to-step transition. The impulse data were well matched by the optimal impulse predictions (R(2)>0.7) that minimized the mechanical work done on the CoM during the gait. The results suggest that the balance of push-off and heel strike energy is a consistent property arising from the overall gait dynamics, which implies an inherited oscillatory behavior of the CoM, possibly by spring-like leg mechanics. Copyright © 2011 Elsevier Ltd. All rights reserved.

Corporate Support of Higher Education 1979.

ERIC Educational Resources Information Center

Council for Financial Aid to Education, New York, NY.

Results of an annual survey of corporate giving to higher education show corporate support continuing to advance, both in dollar amounts and in relation to several important indicators. Among the highlights are these: national estimates show education support at a new high of $870 million, a 17.6 percent rise over 1978 and almost double the 1975…

Peptostreptococcus productus strain that grows rapidly with CO as the energy source.

PubMed Central

Lorowitz, W H; Bryant, M P

1984-01-01

Anaerobic bacteria were enriched with a sewage digestor sludge inoculum and a mineral medium supplemented with B-vitamins and 0.05% yeast extract and with a 50% CO-30% N2-20% CO2 (2 atm [202 kPa]) gas phase. Microscopic observation revealed an abundance of gram-positive cocci, 1.0 by 1.4 micron, which occurred in pairs or chains. The coccus, strain U-1, was isolated by using roll tubes with CO as the energy source. Based on morphology, sugars fermented, fermentation products from glucose (H2, acetate, lactate, and succinate), and other features, strain U-1 was identified as Peptostreptococcus productus IIb (similar to the type strain). The doubling time with up to 50% CO was 1.5 h; acetate and CO2 were the major products. In addition, no significant change in the doubling time was observed with 90% CO. Some stock strains were also able to use CO, although not as well. Strain U-1 produced acetate during growth with H2-CO2. Other C1 compounds did not support growth. Most probable numbers of CO utilizers morphologically identical with strain U-1 were 7.5 X 10(6) and 1.1 X 10(5) cells per g for anaerobic digestor sludge and human feces, respectively. PMID:6430231

High-repetition-rate setup for pump-probe time-resolved XUV-IR experiments employing ion and electron momentum imaging

NASA Astrophysics Data System (ADS)

Pathak, Shashank; Robatjazi, Seyyed Javad; Wright Lee, Pearson; Raju Pandiri, Kanaka; Rolles, Daniel; Rudenko, Artem

2017-04-01

J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan KS, USA We report on the development of a versatile experimental setup for XUV-IR pump-probe experiments using a 10 kHz high-harmonic generation (HHG) source and two different charged-particle momentum imaging spectrometers. The HHG source, based on a commercial KM Labs eXtreme Ultraviolet Ultrafast Source, is capable of delivering XUV radiation of less than 30 fs pulse duration in the photon energy range of 17 eV to 100 eV. It can be coupled either to a conventional velocity map imaging (VMI) setup with an atomic, molecular, or nanoparticle target; or to a novel double-sided VMI spectrometer equipped with two delay-line detectors for coincidence studies. An overview of the setup and results of first pump-probe experiments including studies of two-color double ionization of Xe and time-resolved dynamics of photoionized CO2 molecule will be presented. This project is supported in part by National Science Foundation (NSF-EPSCOR) Award No. IIA-1430493 and in part by the Chemical science, Geosciences, and Bio-Science division, Office of Basic Energy Science, Office of science, U.S. Department of Energy. K.

Double incontinence in a cohort of nulliparous pregnant women.

PubMed

Espuña-Pons, Montserrat; Solans-Domènech, Maite; Sánchez, Emília

2012-11-01

To estimate the frequency of double incontinence, and to identify associated risk factors during pregnancy and postpartum in previously continent nulliparous women. A cohort study in healthy, nulliparous, continent pregnant women, attending the public healthcare system of Catalonia (Spain) was designed. The field work was conducted during the control visits of pregnancy, at the time of delivery, and in the postpartum. Double incontinence was defined as a situation in which participants reported simultaneously urinary incontinence (UI) and anal incontinence with the help of a self-administered questionnaire. Prevalence rates, and their corresponding confidence intervals (95% CI), were calculated, as well as the impact on daily life. Multivariable logistic regressions in pregnancy and postpartum were estimated to assess the association of potential risk factors. The prevalence rate of double incontinence during pregnancy was 8.6% (95% CI: 7.0-10.3). Age over 35 years, and family history of UI were associated to a higher risk of double incontinence. After delivery, the prevalence rate decreased to 3.5% (95% CI: 2.4-4.6); only 6.7% of women with double incontinence in pregnancy had a persistency of their symptoms in early postpartum. Instrumental vaginal deliveries carried 2.2 times more risk of double incontinence than spontaneous ones. Episiotomy implied a higher risk for double incontinence. Symptoms of double incontinence are prevalent during first pregnancy; age and other intrinsic factors may favor the occurrence of double incontinence throughout gestation, while instrumental delivery and episiotomy increase the risk of double incontinence in the postpartum period. Copyright © 2012 Wiley Periodicals, Inc.

The impact of surface chemistry on the performance of localized solar-driven evaporation system

PubMed Central

Yu, Shengtao; Zhang, Yao; Duan, Haoze; Liu, Yanming; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2015-01-01

This report investigates the influence of surface chemistry (or wettability) on the evaporation performance of free-standing double-layered thin film on the surface of water. Such newly developed evaporation system is composed of top plasmonic light-to-heat conversion layer and bottom porous supporting layer. Under solar light illumination, the induced plasmonic heat will be localized within the film. By modulating the wettability of such evaporation system through the control of surface chemistry, the evaporation rates are differentiated between hydrophilized and hydrophobized anodic aluminum oxide membrane-based double layered thin films. Additionally, this work demonstrated that the evaporation rate mainly depends on the wettability of bottom supporting layer rather than that of top light-to-heat conversion layer. The findings in this study not only elucidate the role of surface chemistry of each layer of such double-layered evaporation system, but also provide additional design guidelines for such localized evaporation system in applications including desalination, distillation and power generation. PMID:26337561

The impact of surface chemistry on the performance of localized solar-driven evaporation system.

PubMed

Yu, Shengtao; Zhang, Yao; Duan, Haoze; Liu, Yanming; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2015-09-04

This report investigates the influence of surface chemistry (or wettability) on the evaporation performance of free-standing double-layered thin film on the surface of water. Such newly developed evaporation system is composed of top plasmonic light-to-heat conversion layer and bottom porous supporting layer. Under solar light illumination, the induced plasmonic heat will be localized within the film. By modulating the wettability of such evaporation system through the control of surface chemistry, the evaporation rates are differentiated between hydrophilized and hydrophobized anodic aluminum oxide membrane-based double layered thin films. Additionally, this work demonstrated that the evaporation rate mainly depends on the wettability of bottom supporting layer rather than that of top light-to-heat conversion layer. The findings in this study not only elucidate the role of surface chemistry of each layer of such double-layered evaporation system, but also provide additional design guidelines for such localized evaporation system in applications including desalination, distillation and power generation.

A bilayer Double Semion Model with Symmetry-Enriched Topological Order

NASA Astrophysics Data System (ADS)

Ortiz, Laura; Martin-Delgado, Miguel Angel

We construct a new model of two-dimensional quantum spin systems that combines intrinsic topological orders and a global symmetry called flavour symmetry. It is referred as the bilayer Doubled Semion model (bDS) and is an instance of symmetry-enriched topological order. A honeycomb bilayer lattice is introduced to combine a Double Semion Topolgical Order with a global spin-flavour symmetry to get the fractionalization of its quasiparticles. The bDS model exhibits non-trival braiding self-statistics of excitations and its dual model constitutes a Symmetry-Protected Topological Order with novel edge states. This dual model gives rise to a bilayer Non-Trivial Paramagnet that is invariant under the flavour symmetry and the well-known spin flip symmetry. We acknowledge financial support from the Spanish MINECO Grants FIS2012-33152, FIS2015-67411, and the CAM research consortium QUITEMAD+, Grant No. S2013/ICE-2801. The research of M.A.M.-D. has been supported in part by the U.S. Army Research Office throu.

Observation of a Discrete Time Crystal

NASA Astrophysics Data System (ADS)

Kyprianidis, A.; Zhang, J.; Hess, P.; Becker, P.; Lee, A.; Smith, J.; Pagano, G.; Potter, A.; Vishwanath, A.; Potirniche, I.-D.; Yao, N.; Monroe, C.

2017-04-01

Spontaneous symmetry breaking is a key concept in the understanding of many physical phenomena, such as the formation of spatial crystals and the phase transition from paramagnetism to magnetic order. While the breaking of time translation symmetry is forbidden in equilibrium systems, it is possible for non-equilibrium Floquet driven systems to break a discrete time translation symmetry, and we present clear signatures of the formation of such a discrete time crystal. We apply a time periodic Hamiltonian to a chain of interacting spins under many-body localization conditions and observe the system's sub-harmonic response at twice that period. This spontaneous doubling of the periodicity is robust to external perturbations. We represent the spins with a linear chain of trapped 171Yb+ ions in an rf Paul trap, generate spin-spin interactions through spin-dependent optical dipole forces, and measure each spin using state-dependent fluorescence. This work is supported by the ARO Atomic Physics Program, the AFOSR MURI on Quantum Measurement and Verification, and the NSF Physics Frontier Center at JQI.

Speeded Recognition of Ungrammaticality: Double Violations.

ERIC Educational Resources Information Center

Moore, Timothy E.; Biederman, Irving

1979-01-01

The speed at which sentences with various kinds of violations could be rejected was studied. Compatible with the sequential model was the finding that noun-verb and adjective-noun double violations did not result in shorter reaction times than noun-verb single violations, although double violations were judged less acceptable. (Author/RD)

Towards NV-based magnetic sensing in the time domain

NASA Astrophysics Data System (ADS)

Urbach, Elana; Sumarac, Tamara; Lovchinsky, Igor; Landig, Renate; Sanchez-Yamagishi, Javier; Andersen, Trond; Park, Hongkun; Lukin, Mikhail

2017-04-01

The study of protein folding dynamics is an outstanding problem in the biological sciences. We show that nitrogen-vacancy (NV) centers in diamond can be used to dynamically sense the conformational states of individual proteins under ambient conditions. We present preliminary data on time-domain detection of electronic spin labels which were chemically attached to the proteins, as well as label-free detection of native hydrogen nuclear spins within the protein. In addition, we discuss work towards polarizing boron-11 spins in atomically-thin hexagonal boron nitride using Hartmann-Hahn double resonance, with the ultimate goal of studying many-body spin dynamics and performing quantum simulation. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE1144152.

Containerless Measurements of Density and Viscosity of Fe-Co Alloys

NASA Technical Reports Server (NTRS)

Lee, Jonghyun; Choufani, Paul; Bradshaw, Richard C.; Hyers, Robert W.; Matson, Douglas M.

2012-01-01

During the past years, extensive collaborative research has been done to understand phase selection in undercooled metals using novel containerless processing techniques such as electrostatic and electromagnetic levitation. Of major interest is controlling a two-step solidification process, double recalescence, in which the metastable phase forms first and then transforms to the stable phase after a certain delay time. The previous research has shown that the delay time is greatly influenced by the internal convection velocity. In the prediction of internal flow, the fidelity of the results depends on the accuracy of the material properties. This research focuses on the measurements of density and viscosity of Fe-Co alloys which will be used for the fluid simulations whose results will support upcoming International Space Station flight experiments.

Market reaction to a bid-ask spread change: A power-law relaxation dynamics

NASA Astrophysics Data System (ADS)

Ponzi, Adam; Lillo, Fabrizio; Mantegna, Rosario N.

2009-07-01

We study the relaxation dynamics of the bid-ask spread and of the midprice after a sudden variation of the spread in a double auction financial market. We find that the spread decays as a power law to its normal value. We measure the price reversion dynamics and the permanent impact, i.e., the long-time effect on price, of a generic event altering the spread and we find an approximately linear relation between immediate and permanent impact. We hypothesize that the power-law decay of the spread is a consequence of the strategic limit order placement of liquidity providers. We support this hypothesis by investigating several quantities, such as order placement rates and distribution of prices and times of submitted orders, which affect the decay of the spread.

Phenotypes and Karyotypes of Human Malignant Mesothelioma Cell Lines

PubMed Central

Relan, Vandana; Morrison, Leanne; Parsonson, Kylie; Clarke, Belinda E.; Duhig, Edwina E.; Windsor, Morgan N.; Matar, Kevin S.; Naidoo, Rishendran; Passmore, Linda; McCaul, Elizabeth; Courtney, Deborah; Yang, Ian A.; Fong, Kwun M.; Bowman, Rayleen V.

2013-01-01

Background Malignant mesothelioma is an aggressive tumour of serosal surfaces most commonly pleura. Characterised cell lines represent a valuable tool to study the biology of mesothelioma. The aim of this study was to develop and biologically characterise six malignant mesothelioma cell lines to evaluate their potential as models of human malignant mesothelioma. Methods Five lines were initiated from pleural biopsies, and one from pleural effusion of patients with histologically proven malignant mesothelioma. Mesothelial origin was assessed by standard morphology, Transmission Electron Microscopy (TEM) and immunocytochemistry. Growth characteristics were assayed using population doubling times. Spectral karyotyping was performed to assess chromosomal abnormalities. Authentication of donor specific derivation was undertaken by DNA fingerprinting using a panel of SNPs. Results Most of cell lines exhibited spindle cell shape, with some retaining stellate shapes. At passage 2 to 6 all lines stained positively for calretinin and cytokeratin 19, and demonstrated capacity for anchorage-independent growth. At passage 4 to 16, doubling times ranged from 30–72 hours, and on spectral karyotyping all lines exhibited numerical chromosomal abnormalities ranging from 41 to 113. Monosomy of chromosomes 8, 14, 22 or 17 was observed in three lines. One line displayed four different karyotypes at passage 8, but only one karyotype at passage 42, and another displayed polyploidy at passage 40 which was not present at early passages. At passages 5–17, TEM showed characteristic features of mesothelioma ultrastructure in all lines including microvilli and tight intercellular junctions. Conclusion These six cell lines exhibit varying cell morphology, a range of doubling times, and show diverse passage-dependent structural chromosomal changes observed in malignant tumours. However they retain characteristic immunocytochemical protein expression profiles of mesothelioma during maintenance in artificial culture systems. These characteristics support their potential as in vitro model systems for studying cellular, molecular and genetic aspects of mesothelioma. PMID:23516439

L-Acetylcarnitine in dysthymic disorder in elderly patients: a double-blind, multicenter, controlled randomized study vs. fluoxetine.

PubMed

Bersani, Giuseppe; Meco, Giuseppe; Denaro, Alessandro; Liberati, Damien; Colletti, Chiara; Nicolai, Raffaella; Bersani, Francesco Saverio; Koverech, Aleardo

2013-10-01

L-Acetylcarnitine (LAC), the acetyl ester of carnitine naturally present in the central nervous system and involved in several neural pathways, has been demonstrated to be active in various animal experimental models resembling some features of human depression. The aim of the study is to verify whether LAC can have an antidepressant action in a population of elderly patients with dysthymic disorder in comparison with a traditional antidepressant such as fluoxetine. Multicentric, double-blind, double-dummy, controlled, randomized study based on a observation period of 7 weeks. 80 patients with DSM-IV diagnosis of dysthymic disorder were enrolled in the study and subdivided into 2 groups. Group A patients received LAC plus placebo; group B patients received fluoxetine 20 mg/die plus placebo. Clinical assessment was performed through several psychometric scales at 6 different moments. Group A patients showed a statistically significant improvement in the following scales: HAM-D, HAM-A, BDI and Touluse Pieron Test. Comparison between the two groups, A and B, generally showed very similar clinical progression. The results obtained with LAC and fluoxetine were equivalent. As the subjects in this study were of senile age, it is possible to hypothesize that the LAC positive effect on mood could be associated with improvement in subjective cognitive symptomatology. The difference in the latency time of clinical response (1 week of LAC treatment, compared with the 2 weeks' latency time with fluoxetine) suggests the existence of different mechanisms of action possibly in relation to the activation of rapid support processes of neuronal activity. Copyright © 2012 Elsevier B.V. and ECNP. All rights reserved.

Characterizing substrate–surface interactions on alumina-supported metal catalysts by dynamic nuclear polarization-enhanced double-resonance NMR spectroscopy [Characterizing substrate-surface interactions on alumina supported metal catalysts by DNP-enhanced double-resonance NMR spectroscopy

DOE PAGES

Perras, Frederic A.; Padmos, J. Daniel; Johnson, Robert L.; ...

2017-01-23

The characterization of nanometer-scale interactions between carbon-containing substrates and alumina surfaces is of paramount importance to industrial and academic catalysis applications, but it is also very challenging. Here, we demonstrate that dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS) allows the unambiguous description of the coordination geometries and conformations of the substrates at the alumina surface through high-resolution measurements of 13C– 27Al distances. We apply this new technique to elucidate the molecular-level geometry of 13C-enriched methionine and natural abundance poly(vinyl alcohol) adsorbed on γ-Al 2O 3-supported Pd catalysts, and we support these results with element-specific X-ray absorption near-edge measurements. Furthermore,more » this work clearly demonstrates a surprising bimodal coordination of methionine at the Pd–Al 2O 3 interface.« less

Characterizing substrate–surface interactions on alumina-supported metal catalysts by dynamic nuclear polarization-enhanced double-resonance NMR spectroscopy [Characterizing substrate-surface interactions on alumina supported metal catalysts by DNP-enhanced double-resonance NMR spectroscopy

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

Perras, Frederic A.; Padmos, J. Daniel; Johnson, Robert L.

The characterization of nanometer-scale interactions between carbon-containing substrates and alumina surfaces is of paramount importance to industrial and academic catalysis applications, but it is also very challenging. Here, we demonstrate that dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS) allows the unambiguous description of the coordination geometries and conformations of the substrates at the alumina surface through high-resolution measurements of 13C– 27Al distances. We apply this new technique to elucidate the molecular-level geometry of 13C-enriched methionine and natural abundance poly(vinyl alcohol) adsorbed on γ-Al 2O 3-supported Pd catalysts, and we support these results with element-specific X-ray absorption near-edge measurements. Furthermore,more » this work clearly demonstrates a surprising bimodal coordination of methionine at the Pd–Al 2O 3 interface.« less

Canonical formulation and conserved charges of double field theory

DOE PAGES

Naseer, Usman

2015-10-26

We provide the canonical formulation of double field theory. It is shown that this dynamics is subject to primary and secondary constraints. The Poisson bracket algebra of secondary constraints is shown to close on-shell according to the C-bracket. We also give a systematic way of writing boundary integrals in doubled geometry. Finally, by including appropriate boundary terms in the double field theory Hamiltonian, expressions for conserved energy and momentum of an asymptotically flat doubled space-time are obtained and applied to a number of solutions.

Foot pressure analysis of gait pattern in older Japanese females requiring different personal care support levels.

PubMed

Takayanagi, Naoto; Sudo, Motoki; Fujii, Masahiko; Sakai, Hirokazu; Morimoto, Keiko; Tomisaki, Masumi; Niki, Yoshifumi; Tokimitsu, Ichiro

2018-03-01

[Purpose] This study evaluated gait parameters and foot pressure in two regions of the feet among older females with different personal care support needs to analyze factors that contribute to higher support requirements. [Subjects and Methods] Thirty-two older females were divided into support-need and care-need level groups. Gait parameters (speed, cadence, step length, step width, gait angle, toe angle, double support phase, swing phase, and stance phase) and foot pressure during a 5-m walk were measured and analyzed in the two groups. [Results] The percentage of the double support phase on both feet and the right stance phase were significantly higher in the care-need level group, while that of the right swing phase was significantly lower than that of the support-need level group. Additionally, the phase showing peak pressure on the left rear foot was significantly delayed and the left forefoot pressure in the terminal stance was significantly lower in the care-need level group than in the support-need level group. [Conclusion] These findings show that the temporal duration parameters and foot pressure on a particular side were significantly different between the two groups and suggest that these differences were associated with a higher care level.

Polymer formulations for gettering hydrogen

DOEpatents

Shepodd, T.J.; Whinnery, L.L.

1998-11-17

A novel composition is described comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen. 1 fig.

Practice and attitudes regarding double gloving among staff surgeons and surgical trainees.

PubMed

Lipson, Mark E; Deardon, Rob; Switzer, Noah J; de Gara, Chris; Ball, Chad G; Grondin, Sean C

2018-06-01

Despite supporting evidence, many staff surgeons and surgical trainees do not routinely double glove. We performed a study to assess rates of and attitudes toward double gloving and the use of eye protection in the operating room. We conducted an electronic survey among all staff surgeons and surgical trainees at 2 tertiary care centres in Alberta between September and November 2015.We analyzed the data using log-binomial regression for binary outcomes to account for multiple independent variables and interactions. For 2-group comparisons, we used a 2-group test of proportions. The response rate was 34.3% (361/1051); 205/698 staff surgeons (29.4%) and 156/353 surgical trainees (44.2%) responded. Trainees were more likely than staff surgeons to ever double glove in the operating room ( p = 0.01) and to do so routinely ( p = 0.01). Staff surgeons were more likely than trainees to never double glove ( p = 0.01). A total of 300/353 respondents (85.0%) reported using eye protection routinely in the operating room. Needle-stick injury was common (184 staff surgeons [92.5%], 115 trainees [74.7%]). Reduced tactile feedback, decreased manual dexterity and discomfort/poor fit were perceived barriers to double gloving. Rates of double gloving leave room for improvement. Surgical trainees were more likely than staff surgeons to double glove. Barriers remain to routine double gloving among staff surgeons and trainees. Increased education on the benefits of double gloving and early introduction of this practice may increase uptake.

Detecting double compressed MPEG videos with the same quantization matrix and synchronized group of pictures structure

NASA Astrophysics Data System (ADS)

Aghamaleki, Javad Abbasi; Behrad, Alireza

2018-01-01

Double compression detection is a crucial stage in digital image and video forensics. However, the detection of double compressed videos is challenging when the video forger uses the same quantization matrix and synchronized group of pictures (GOP) structure during the recompression history to conceal tampering effects. A passive approach is proposed for detecting double compressed MPEG videos with the same quantization matrix and synchronized GOP structure. To devise the proposed algorithm, the effects of recompression on P frames are mathematically studied. Then, based on the obtained guidelines, a feature vector is proposed to detect double compressed frames on the GOP level. Subsequently, sparse representations of the feature vectors are used for dimensionality reduction and enrich the traces of recompression. Finally, a support vector machine classifier is employed to detect and localize double compression in temporal domain. The experimental results show that the proposed algorithm achieves the accuracy of more than 95%. In addition, the comparisons of the results of the proposed method with those of other methods reveal the efficiency of the proposed algorithm.

Morphologies, Preparations and Applications of Layered Double Hydroxide Micro-/Nanostructures

PubMed Central

Kuang, Ye; Zhao, Lina; Zhang, Shuai; Zhang, Fazhi; Dong, Mingdong; Xu, Sailong

2010-01-01

Layered double hydroxides (LDHs), also well-known as hydrotalcite-like layered clays, have been widely investigated in the fields of catalysts and catalyst support, anion exchanger, electrical and optical functional materials, flame retardants and nanoadditives. This feature article focuses on the progress in micro-/nanostructured LDHs in terms of morphology, and also on the preparations, applications, and perspectives of the LDHs with different morphologies. PMID:28883378

Stress and Family Quality of Life in Parents of Children with Autism Spectrum Disorder: Parent Gender and the Double ABCX Model

ERIC Educational Resources Information Center

McStay, Rebecca L.; Trembath, David; Dissanayake, Cheryl

2014-01-01

Past research has supported the utility of the Double ABCX model of family adaptation for parents raising a child with autism spectrum disorder (ASD). What remains unclear is the impact of family-related variables on outcomes in both mothers and fathers within the same family. We explored the potential predictors of maternal and paternal stress…

Tenfold increase in the Rabi decay time of the quantum dot hybrid qubit

NASA Astrophysics Data System (ADS)

Thorgrimsson, Brandur; Kim, Dohun; Simmons, C. B.; Ward, Daniel R.; Foote, Ryan H.; Savage, D. E.; Lagally, M. G.; Friesen, Mark; Coppersmith, S. N.; Eriksson, M. A.

The quantum dot hybrid qubit is formed from three electrons in a double quantum dot. In previous work, we showed that the hybrid qubit has the speed of a charge qubit and the stability of a spin qubit. Here, we show that the hybrid qubit is also highly tunable, and can be tuned into regimes with desirable coherence properties. By changing the interdot tunnel rate by only 25%, from 5 GHz to 6.25 GHz, we are able to increase the Rabi decay time by a factor of ten, from 18 ns to 177 ns. We attribute this improvement to the refinement of an extended ``sweet spot'' in the energy dispersion of the hybrid qubit, where the qubit is less susceptible to charge noise, which is a dominant source of decoherence. This work was supported in part by ARO (W911NF-12-0607) and NSF (DMR-1206915 and PHY-1104660). Development and maintenance of the growth facilities used for fabricating samples is sup- ported by DOE (DE-FG02-03ER46028). This research utilized NSF-supported shared facilities at the University of Wisconsin-Madison.

[Subjective Gait Stability in the Elderly].

PubMed

Hirsch, Theresa; Lampe, Jasmin; Michalk, Katrin; Röder, Lotte; Munsch, Karoline; Marquardt, Jonas

2017-07-10

It can be assumed that the feeling of gait stability or gait instability in the elderly may be independent of a possible fear of falling or a history of falling when walking. Up to now, there has been a lack of spatiotemporal gait parameters for older people who subjectively feel secure when walking. The aim of the study is to analyse the distribution of various gait parameters for older people who subjectively feel secure when walking. In a cross-sectional study, the gait parameters stride time, step time, stride length, step length, double support, single support, and walking speed were measured using a Vicon three-dimensional motion capture system (Plug-In Gait Lower-Body Marker Set) in 31 healthy people aged 65 years and older (mean age 72 ± 3.54 years) who subjectively feel secure when walking. There was a homogeneous distribution in the gait parameters examined, with no abnormalities. The mean values have a low variance with narrow confidence intervals. This study provides evidence that people who subjectively feel secure when walking demonstrate similarly objective gait parameters..

Implementation of Super-Encryption with Trithemius Algorithm and Double Transposition Cipher in Securing PDF Files on Android Platform

NASA Astrophysics Data System (ADS)

Budiman, M. A.; Rachmawati, D.; Jessica

2018-03-01

This study aims to combine the trithemus algorithm and double transposition cipher in file security that will be implemented to be an Android-based application. The parameters being examined are the real running time, and the complexity value. The type of file to be used is a file in PDF format. The overall result shows that the complexity of the two algorithms with duper encryption method is reported as Θ (n 2). However, the processing time required in the encryption process uses the Trithemius algorithm much faster than using the Double Transposition Cipher. With the length of plaintext and password linearly proportional to the processing time.

Corticosteroid therapy in refractory shock following cardiac arrest: a randomized, double-blind, placebo-controlled, trial.

PubMed

Donnino, Michael W; Andersen, Lars W; Berg, Katherine M; Chase, Maureen; Sherwin, Robert; Smithline, Howard; Carney, Erin; Ngo, Long; Patel, Parth V; Liu, Xiaowen; Cutlip, Donald; Zimetbaum, Peter; Cocchi, Michael N

2016-04-03

The purpose of this study was to determine whether the provision of corticosteroids improves time to shock reversal and outcomes in patients with post-cardiac arrest shock. We conducted a randomized, double-blind trial of post-cardiac arrest patients in shock, defined as vasopressor support for a minimum of 1 hour. Patients were randomized to intravenous hydrocortisone 100 mg or placebo every 8 hours for 7 days or until shock reversal. The primary endpoint was time to shock reversal. Fifty patients were included with 25 in each group. There was no difference in time to shock reversal between groups (hazard ratio: 0.83 [95% CI: 0.40-1.75], p = 0.63). We found no difference in secondary outcomes including shock reversal (52% vs. 60%, p = 0.57), good neurological outcome (24% vs. 32%, p = 0.53) or survival to discharge (28% vs. 36%, p = 0.54) between the hydrocortisone and placebo groups. Of the patients with a baseline cortisol < 15 ug/dL, 100% (6/6) in the hydrocortisone group achieved shock reversal compared to 33% (1/3) in the placebo group (p = 0.08). All patients in the placebo group died (100%; 3/3) whereas 50% (3/6) died in the hydrocortisone group (p = 0.43). In a population of cardiac arrest patients with vasopressor-dependent shock, treatment with hydrocortisone did not improve time to shock reversal, rate of shock reversal, or clinical outcomes when compared to placebo. Clinicaltrials.gov: NCT00676585, registration date: May 9, 2008.

Protecting Children and Supporting Families.

ERIC Educational Resources Information Center

Wolf, Kathy Goetz, Ed.

1997-01-01

This serial "double issue" focuses on protecting children and supporting families through greater collaboration between child welfare services and family resource programs. The issue includes the featured articles: (1) "Making the Media a Constructive Force in Child Welfare" (Kathy Bonk), which discusses how the media and child welfare agencies…

Double-deprotected chemically amplified photoresists (DD-CAMP): higher-order lithography

NASA Astrophysics Data System (ADS)

Earley, William; Soucie, Deanna; Hosoi, Kenji; Takahashi, Arata; Aoki, Takashi; Cardineau, Brian; Miyauchi, Koichi; Chun, Jay; O'Sullivan, Michael; Brainard, Robert

2017-03-01

The synthesis and lithographic evaluation of 193-nm and EUV photoresists that utilize a higher-order reaction mechanism of deprotection is presented. Unique polymers utilize novel blocking groups that require two acid-catalyzed steps to be removed. When these steps occur with comparable reaction rates, the overall reaction can be higher order (<= 1.85). The LWR of these resists is plotted against PEB time for a variety of compounds to acquire insight into the effectiveness of the proposed higher-order mechanisms. Evidence acquired during testing of these novel photoresist materials supports the conclusion that higher-order reaction kinetics leads to improved LWR vs. control resists.

Biomechanical properties of double- and single-row suture anchor repair for surgical treatment of insertional Achilles tendinopathy.

PubMed

Beitzel, Knut; Mazzocca, Augustus D; Obopilwe, Elifho; Boyle, James W; McWilliam, James; Rincon, Lina; Dhar, Yasmin; Arciero, Robert A; Amendola, Annunziato

2013-07-01

Because of intratendinous ossifications, retrocalcaneal bursitis, or intratendinous necrosis commonly found in insertional tendinosis, it is often necessary to detach the tendon partially or entirely from its tendon-to-bone junction. Double-row repair for insertional Achilles tendinopathy will generate an increased contact area and demonstrate higher biomechanical stability. Controlled laboratory study. Eighteen cadaver Achilles tendons were split longitudinally and detached, exposing the calcaneus; an ostectomy was performed and the tendon was reattached to the calcaneus in 1 of 2 ways: 2 suture anchors (single row) or a 4-anchor (double row) construct. Footprint area measurements over time, displacement after cyclic loading (2000 cycles), and final load to failure were measured. The double-row refixation technique was statistically superior to the single-row technique in footprint area measurement initially and 5 minutes after repair (P = .009 and P = .01, respectively) but not after 24 hours (P = .713). The double-row construct demonstrated significantly improved measures for peak load (433.9 ± 84.3 N vs 212.0 ± 49.7 N; P = .042), load at yield (354.7 ± 106.2 N vs 198.7 ± 39.5 N; P = .01), and slope (51.8 ± 9.9 N/mm vs 66.7 ± 16.2 N/mm; P = .021). Cyclic loading did not demonstrate significant differences between the 2 constructs. Double-row construct for reinsertion of a completely detached Achilles tendon using proximal and distal rows resulted in significantly larger contact area initially and 5 minutes after repair and led to significantly higher peak load to failure on destructive testing. In treatment for insertional Achilles tendinosis, the tendon often has to be detached and anatomically reattached to its insertion at the calcaneus. To our knowledge there is a lack of biomechanical studies supporting either a number or a pattern of suture anchor fixation. Because the stresses going across the insertion site of the Achilles tendon are significant during rehabilitation and weightbearing activities, it is imperative to have a strong construct that allows satisfactory healing during the early postoperative process.

Computing the variations in the self-similar properties of the various gait intervals in Parkinson disease patients.

PubMed

Manjeri Keloth, Sana; Arjunan, Sridhar P; Kumar, Dinesh

2017-07-01

This study has investigated the stride, swing, stance and double support intervals of gait for Parkinson's disease (PD) patients with different levels of severity. Self-similar properties of the gait signal were analyzed to investigate the changes in the gait pattern of the healthy and PD patients. To understand the self-similar property, detrended fluctuation analysis was performed. The analysis shows that the PD patients have less defined gait when compared to healthy. The study also shows that among the stance and swing phase of stride interval, the self-similarity is less for swing interval when compared to the stance interval of gait and decreases with the severity of gait. Also, PD patients show decreased self-similar patterns in double support interval of gait. This suggest that there are less rhythmic gait intervals and a sense of urgency to remain in support phase of gait by the PD patients.

Antioxidant effects of 14 Chinese traditional medicinal herbs against human low-density lipoprotein oxidation.

PubMed

Lin, Hsin-Hung; Charles, Albert Linton; Hsieh, Chang-Wei; Lee, Ya-Chi; Ciou, Jhih-Ying

2015-01-01

The relationship between the antioxidant activities and inhibitory effect of 14 Chinese medicinal herbs against oxidized low-density lipoprotein (LDL) formation was evaluated. Prolongation of the lag phase of LDL oxidation depended on the concentration of the herbs. The concentration of each herb that was able to prolong the lag time by about two-fold was calculated and expressed as doubling-time concentration. The lower the doubling-time concentration, the stronger the inhibitory effect exhibited toward LDL oxidation. Among them, Chrysanthemi Flos (Chrysanthemum morifolium ramat; gān jú huā), Crataegi Fructus (Crataegus pinnatifida Bge. var. major N.E.Br.; shān zhā), and Roselle (Hibiscus sabdariffa Linn.; luò shén) showed significant inhibitory effects. Correlation coefficients between doubling-time concentration and radical-scavenging activities were high; the total phenolic content was also high. In conclusion, phenolic compounds contributed not only to antioxidant activities, but also to the inhibitory effect against LDL oxidation. Chrysanthemi Flos, Crataegi Fructus, and H. sabdariffa, with lower doubling-time concentrations, could be potent phytochemical agents to reduce LDL oxidation and prevent the progression of atherosclerosis.

Naltrexone versus acamprosate in the treatment of alcohol dependence: A multi-centre, randomized, double-blind, placebo-controlled trial.

PubMed

Morley, Kirsten C; Teesson, Maree; Reid, Sophie C; Sannibale, Claudia; Thomson, Clare; Phung, Nghi; Weltman, Martin; Bell, James R; Richardson, Kylie; Haber, Paul S

2006-10-01

To compare the efficacy of acamprosate and naltrexone in the treatment of alcohol dependence. A double-blind, placebo-controlled trial. Three treatment centres in Australia. A total of 169 alcohol dependent subjects were given naltrexone (50 mg/day), acamprosate (1998 mg/day) or placebo for 12 weeks. All subjects were offered manualized compliance therapy, a brief intervention that targets problems that may affect treatment compliance such as ambivalence and misperceptions about medication. Time to the first drink, time to first relapse, drinks per drinking day and cumulative abstinence. In intention-to-treat analyses, there were no differences between groups on outcome measures of drinking, craving or biochemical markers. Similarly, analyses of the 94 subjects that completed the study in full and demonstrated 80% compliance, revealed no significant treatment effects. Differential treatment effects were identified after stratification according to scores on the Alcohol Dependence Scale (ADS) and Depression Anxiety and Stress Scale (DASS). A significant beneficial treatment effect on time to first relapse was revealed for subjects with 'no depression' allocated to naltrexone (n = 56; P < 0.01). In addition, a significant beneficial treatment effect was revealed in subjects with 'low dependence' allocated to naltrexone (n = 34; P < 0.05). The results of this study support the efficacy of naltrexone in the relapse prevention of alcoholism amongst those with low levels of clinical depression and alcohol dependence severity. No effect of acamprosate was found in our sample.

Pd/Ni-WO3 anodic double layer gasochromic device

DOEpatents

Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland; Liu, Ping

2004-04-20

An anodic double layer gasochromic sensor structure for optical detection of hydrogen in improved response time and with improved optical absorption real time constants, comprising: a glass substrate; a tungsten-doped nickel oxide layer coated on the glass substrate; and a palladium layer coated on the tungsten-doped nickel oxide layer.

Attosecond Spectroscopy Probing Electron Correlation Dynamics

NASA Astrophysics Data System (ADS)

Winney, Alexander H.

Electrons are the driving force behind every chemical reaction. The exchange, ionization, or even relaxation of electrons is behind every bond broken or formed. According to the Bohr model of the atom, it takes an electron 150 as to orbit a proton[6]. With this as a unit time scale for an electron, it is clear that a pulse duration of several femtoseconds will not be sufficient to understanding electron dynamics. Our work demonstrates both technical and scientific achievements that push the boundaries of attosecond dynamics. TDSE studies show that amplification the yield of high harmonic generation (HHG) may be possible with transverse confinement of the electron. XUV-pump-XUV-probe shows that the yield of APT train can be sufficient for 2-photon double ionization studies. A zero dead-time detection system allows for the measurement of state-resolved double ionization for the first time. Exploiting attosecond angular streaking[7] probes sequential and non-sequential double ionization via electron-electron correlations with attosecond time resolution. Finally, using recoil frame momentum correlation, the fast dissociation of CH 3I reveals important orbital ionization dynamics of non-dissociative & dissociative, single & double ionization.

Pre- and post-head processing for single- and double-scrambled sentences of a head-final language as measured by the eye tracking method.

PubMed

Tamaoka, Katsuo; Asano, Michiko; Miyaoka, Yayoi; Yokosawa, Kazuhiko

2014-04-01

Using the eye-tracking method, the present study depicted pre- and post-head processing for simple scrambled sentences of head-final languages. Three versions of simple Japanese active sentences with ditransitive verbs were used: namely, (1) SO₁O₂V canonical, (2) SO₂O₁V single-scrambled, and (3) O₁O₂SV double-scrambled order. First pass reading times indicated that the third noun phrase just before the verb in both single- and double-scrambled sentences required longer reading times compared to canonical sentences. Re-reading times (the sum of all fixations minus the first pass reading) showed that all noun phrases including the crucial phrase before the verb in double-scrambled sentences required longer re-reading times than those required for single-scrambled sentences; single-scrambled sentences had no difference from canonical ones. Therefore, a single filler-gap dependency can be resolved in pre-head anticipatory processing whereas two filler-gap dependencies require much greater cognitive loading than a single case. These two dependencies can be resolved in post-head processing using verb agreement information.

Theoretical analysis of optical poling and frequency doubling effect based on classical model

NASA Astrophysics Data System (ADS)

Feng, Xi; Li, Fuquan; Lin, Aoxiang; Wang, Fang; Chai, Xiangxu; Wang, Zhengping; Zhu, Qihua; Sun, Xun; Zhang, Sen; Sun, Xibo

2018-03-01

Optical poling and frequency doubling effect is one of the effective manners to induce second order nonlinearity and realize frequency doubling in glass materials. The classical model believes that an internal electric field is built in glass when it's exposed by fundamental and frequency-doubled light at the same time, and second order nonlinearity appears as a result of the electric field and the orientation of poles. The process of frequency doubling in glass is quasi phase matched. In this letter, the physical process of poling and doubling process in optical poling and frequency doubling effect is deeply discussed in detail. The magnitude and direction of internal electric field, second order nonlinear coefficient and its components, strength and direction of frequency doubled output signal, quasi phase matched coupled wave equations are given in analytic expression. Model of optical poling and frequency doubling effect which can be quantitatively analyzed are constructed in theory, which set a foundation for intensive study of optical poling and frequency doubling effect.

Nonlinear Diamagnetic Stabilization of Double Tearing Modes in Cylindrical MHD Simulations

NASA Astrophysics Data System (ADS)

Abbott, Stephen; Germaschewski, Kai

2014-10-01

Double tearing modes (DTMs) may occur in reversed-shear tokamak configurations if two nearby rational surfaces couple and begin reconnecting. During the DTM's nonlinear evolution it can enter an ``explosive'' growth phase leading to complete reconnection, making it a possible driver for off-axis sawtooth crashes. Motivated by similarities between this behavior and that of the m = 1 kink-tearing mode in conventional tokamaks we investigate diamagnetic drifts as a possible DTM stabilization mechanism. We extend our previous linear studies of an m = 2 , n = 1 DTM in cylindrical geometry to the fully nonlinear regime using the MHD code MRC-3D. A pressure gradient similar to observed ITB profiles is used, together with Hall physics, to introduce ω* effects. We find the diamagnetic drifts can have a stabilizing effect on the nonlinear DTM through a combination of large scale differential rotation and mechanisms local to the reconnection layer. MRC-3D is an extended MHD code based on the libMRC computational framework. It supports nonuniform grids in curvilinear coordinates with parallel implicit and explicit time integration.

Ultrafast electronic dynamics driven by nuclear motion

NASA Astrophysics Data System (ADS)

Vendrell, Oriol

2016-05-01

The transfer of electrical charge on a microscopic scale plays a fundamental role in chemistry, in biology, and in technological applications. In this contribution, we will discuss situations in which nuclear motion plays a central role in driving the electronic dynamics of photo-excited or photo-ionized molecular systems. In particular, we will explore theoretically the ultrafast transfer of a double electron hole between the functional groups of glycine after K-shell ionization and subsequent Auger decay. Although a large energy gap of about 15 eV initially exists between the two electronic states involved and coherent electronic dynamics play no role in the hole transfer, we will illustrate how the double hole can be transferred within 3 to 4 fs between both functional ends of the glycine molecule driven solely by specific nuclear displacements and non-Born-Oppenheimer effects. This finding challenges the common wisdom that nuclear dynamics of the molecular skeleton are unimportant for charge transfer processes at the few-femtosecond time scale and shows that they can even play a prominent role. We thank the Hamburg Centre for Ultrafast Imaging and the Volkswagen Foundation for financial support.

Solute-solvent interactions in chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane at 308.15 K according to ultrasonic and viscosity data

NASA Astrophysics Data System (ADS)

Gangani, B. J.; Patel, J. P.; Parsania, P. H.

2015-12-01

The density, viscosity and ultrasonic speed (2 MHz) of chloroform solutions of halogenated symmetric double Schiff bases of 1,1'-bis(4-aminophenyl)cyclohexane were investigated at 308.15 K. Various acoustical parameters such as specific acoustical impedance ( Z), adiabatic compressibility ( Ka), Rao's molar sound function ( R m), van der Waals constant ( b), internal pressure (π), free volume ( V f), intermolecular free path length ( L f), classical absorption coefficient (α/ f 2)Cl) and viscous relaxation time (τ) were determine using ultrasonic speed ( U), viscosity (η) and density (ρ) data of Schiff bases solutions and correlated with concentration. Linear increase of Z, b, R, τ, and (α/ f 2)Cl except π (nonlinear) and linear decrease of Ka and L f except V f (nonlinear) with increasing concentration of Schiff bases suggested presence of strong molecular interactions in the solutions. The positive values of solvation number further supported strong molecular interactions in the solutions. The nature and position of halogen substituent also affected the strength of molecular interactions.

Direct evidence of double-slope power spectra in the high-latitude ionospheric plasma

NASA Astrophysics Data System (ADS)

Spicher, A.; Miloch, W. J.; Moen, J. I.

2014-03-01

We report direct observations of the double-slope power spectra for plasma irregularities in the F layer of the polar ionosphere. The investigation of cusp irregularities ICI-2 sounding rocket, which was launched into the polar cusp ionosphere, intersected enhanced plasma density regions with decameter-scale irregularities. Density measurements at unprecedented high resolution with multi-Needle Langmuir Probes allowed for a detailed study of the plasma irregularities down to kinetic scales. Spectral analysis reveals double-slope power spectra for regions of enhanced fluctuations associated mainly with density gradients, with the steepening of the spectra occurring close to the oxygen gyrofrequency. These findings are further supported with the first results from the ICI-3 rocket, which flew through regions with strong precipitation and velocity shears. Previously, double-slope spectra have been observed in the equatorial ionosphere. The present work gives a direct evidence that the double-slope power spectra can be common in the high-latitude ionosphere.

Apparatus for observing a hostile environment

DOEpatents

Nance, Thomas A.; Boylston, Micah L.; Robinson, Casandra W.; Sexton, William C.; Heckendorn, Frank M.

2000-01-01

An apparatus is provided for observing a hostile environment, comprising a housing and a camera capable of insertion within the housing. The housing is a double wall assembly with an inner and outer wall with an hermetically sealed chamber therebetween. A housing for an optical system used to observe a hostile environment is provided, comprising a transparent, double wall assembly. The double wall assembly has an inner wall and an outer wall with an hermetically sealed chamber therebetween. The double wall assembly has an opening and a void area in communication with the opening. The void area of the housing is adapted to accommodate the optical system within said void area. An apparatus for protecting an optical system used to observe a hostile environment is provided comprising a housing; a tube positioned within the housing; and a base for supporting the housing and the tube. The housing comprises a double wall assembly having an inner wall and an outerwall with an hermetically sealed chamber therebetween. The tube is adapted to house the optical system therein.

A double medium model for diffusion in fluid-bearing rock

NASA Astrophysics Data System (ADS)

Wang, H. F.

1993-09-01

The concept of a double porosity medium to model fluid flow in fractured rock has been applied to model diffusion in rock containing a small amount of a continuous fluid phase that surrounds small volume elements of the solid matrix. The model quantifies the relative role of diffusion in the fluid and solid phases of the rock. The fluid is the fast diffusion path, but the solid contains the volumetrically significant amount of the diffusing species. The double medium model consists of two coupled differential equations. One equation is the diffusion equation for the fluid concentration; it contains a source term for change in the average concentration of the diffusing species in the solid matrix. The second equation represents the assumption that the change in average concentration in a solid element is proportional to the difference between the average concentration in the solid and the concentration in the fluid times the solid-fluid partition coefficient. The double medium model is shown to apply to laboratory data on iron diffusion in fluid-bearing dunite and to measured oxygen isotope ratios at marble-metagranite contacts. In both examples, concentration profiles are calculated for diffusion taking place at constant temperature, where a boundary value changes suddenly and is subsequently held constant. Knowledge of solid diffusivities can set a lower bound to the length of time over which diffusion occurs, but only the product of effective fluid diffusivity and time is constrained for times longer than the characteristic solid diffusion time. The double medium results approach a local, grain-scale equilibrium model for times that are large relative to the time constant for solid diffusion.

Interactive Internet Based Pendulum for Learning Mechatronics

NASA Astrophysics Data System (ADS)

Sethson, Magnus R.

2003-01-01

This paper describes an Internet based remote experimental setup of a double lined pendulum mechanism for students experiments at the M. Sc. Level. Some of the first year experience using this web-based setup in classes is referred. In most of the courses given at the division of mechanical engineering systems at Linkoeping Institute of Technology we provide experimental setups to enhance the teaching Of M.Sc. students. Many of these experimental setups involve mechatronical systems. Disciplines like fluid power, electronics, and mechanics and also software technologies are used in each experiment. As our campus has recently been split into two different cities some new concepts for distance learning have been studied. The one described here tries to implement remotely controlled mechatronic setups for teaching basic programming of real-time operating systems and analysis of the dynamics of mechanical systems. The students control the regulators for the pendulum through a web interface and get measurement results and a movie back through their email. The present setup uses a double linked pendulum that is controlled by a DC-motor and monitored through both camera and angular position sensors. All software needed is hosted on a double-processor PC running the RedHat 7.1. distribution complemented with real-time scheduling using DIAPM-RTAI 1.7. The Internet site is presented to the students using PHP, Apache and MySQL. All of the used software originates from the open source domain. The experience from integrating these technologies and security issues is discussed together with the web-camera interface. One of the important experiences from this project so far is the need for a good visual feedback. This is both in terms of video speed but also in resolution. It has been noticed that when the students makes misstates and wants to search the failure they want clear, large images with high resolution to support their personal believes in the cause of the failure. Even if the student does not need a high resolution image to get the idea of the mechanics and the function of the pendulum, they need such high quality images to get confidence in the hardware. It is important to support this when the ability to direct hand-on contact with the hardware is taken away. Some of the experiences in combining open source software; real-time scheduling and measurement hardware into a cost efficient way is also discussed. The pendulum has been available publicly on the Internet but has now been removed due to security issues.

'Someone batting in my corner': experiences of smoking-cessation support via text message.

PubMed

Douglas, Nicolas; Free, Caroline

2013-11-01

The txt2stop trial demonstrated that smoking-cessation support delivered by text message doubles biochemically verified abstinence at 6 months. There was no significant heterogeneity in any of the pre-specified subgroups. To explore participants' experiences of the txt2stop intervention via a qualitative study using telephone interviews. Qualitative telephone interviews in the community. Thematic content analysis of 1283 feedback forms was conducted to develop a topic guide for 25 telephone interviews. Key themes were identified and described. Any differences in the experiences of those who did, and did not, successfully quit were specifically explored. Participants liked the fact that smoking-cessation support delivered by text message was convenient, easy to access, and chemical free. They reported that the intervention was a reminder that they were quitting and why, provided emotional support, was a reminder of the physical benefits of stopping smoking, and they saved messages so they could refer back to them. However, the intervention was not helpful for all. Receiving texts about smoking could also stimulate craving, and the timing, frequency, and duration of messages were not optimal for some participants. Those who did not quit reported that additional factors influenced them, such as periods of stress or social events, or reported that they had been unable to cope with the physical effects of withdrawal, and combining text-message support with medication could help with this. Although the intervention did stimulate craving in some participants at some times, recipients reported that it also provided emotional support and reinforcement at temporally appropriate moments. It was successful at helping people to quit smoking but could be used together with other forms of smoking-cessation support.

‘Someone batting in my corner’: experiences of smoking-cessation support via text message

PubMed Central

Douglas, Nicolas; Free, Caroline

2013-01-01

Background The txt2stop trial demonstrated that smoking-cessation support delivered by text message doubles biochemically verified abstinence at 6 months. There was no significant heterogeneity in any of the pre-specified subgroups. Aim To explore participants’ experiences of the txt2stop intervention via a qualitative study using telephone interviews. Design and setting Qualitative telephone interviews in the community. Method Thematic content analysis of 1283 feedback forms was conducted to develop a topic guide for 25 telephone interviews. Key themes were identified and described. Any differences in the experiences of those who did, and did not, successfully quit were specifically explored. Results Participants liked the fact that smoking-cessation support delivered by text message was convenient, easy to access, and chemical free. They reported that the intervention was a reminder that they were quitting and why, provided emotional support, was a reminder of the physical benefits of stopping smoking, and they saved messages so they could refer back to them. However, the intervention was not helpful for all. Receiving texts about smoking could also stimulate craving, and the timing, frequency, and duration of messages were not optimal for some participants. Those who did not quit reported that additional factors influenced them, such as periods of stress or social events, or reported that they had been unable to cope with the physical effects of withdrawal, and combining text-message support with medication could help with this. Conclusion Although the intervention did stimulate craving in some participants at some times, recipients reported that it also provided emotional support and reinforcement at temporally appropriate moments. It was successful at helping people to quit smoking but could be used together with other forms of smoking-cessation support. PMID:24267860

Hohlraum-driven mid-Z (SiO2) double-shell implosions on the omega laser facility and their scaling to NIF.

PubMed

Robey, H F; Amendt, P A; Milovich, J L; Park, H-S; Hamza, A V; Bono, M J

2009-10-02

High-convergence, hohlraum-driven implosions of double-shell capsules using mid-Z (SiO2) inner shells have been performed on the OMEGA laser facility [T. R. Boehly, Opt. Commun. 133, 495 (1997)]. These experiments provide an essential extension of the results of previous low-Z (CH) double-shell implosions [P. A. Amendt, Phys. Rev. Lett. 94, 065004 (2005)] to materials of higher density and atomic number. Analytic modeling, supported by highly resolved 2D numerical simulations, is used to account for the yield degradation due to interfacial atomic mixing. This extended experimental database from OMEGA enables a validation of the mix model, and provides a means for quantitatively assessing the prospects for high-Z double-shell implosions on the National Ignition Facility [Paisner, Laser Focus World 30, 75 (1994)].

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions

PubMed Central

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-01-01

A series of different types of wax esters (represented by RCOOR′) were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS3 (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2]+, [RCO]+ and [RCO – H2O]+ that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: 1) [RCOOH2]+ for saturated wax esters, 2) [RCOOH2]+, [RCO]+ and [RCO – H2O]+ for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and 3) [RCOOH2]+ and [RCO]+ for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R′]+ and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2]+ ions for all types of wax esters and [R′ – 2H]+ ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions. PMID:26178197

Characterization of Wax Esters by Electrospray Ionization Tandem Mass Spectrometry: Double Bond Effect and Unusual Product Ions.

PubMed

Chen, Jianzhong; Green, Kari B; Nichols, Kelly K

2015-08-01

A series of different types of wax esters (represented by RCOOR') were systematically studied by using electrospray ionization (ESI) collision-induced dissociation tandem mass spectrometry (MS/MS) along with pseudo MS(3) (in-source dissociation combined with MS/MS) on a quadrupole time-of-flight (Q-TOF) mass spectrometer. The tandem mass spectra patterns resulting from dissociation of ammonium/proton adducts of these wax esters were influenced by the wax ester type and the collision energy applied. The product ions [RCOOH2](+), [RCO](+) and [RCO-H2O](+) that have been reported previously were detected; however, different primary product ions were demonstrated for the three wax ester types including: (1) [RCOOH2](+) for saturated wax esters, (2) [RCOOH2](+), [RCO](+) and [RCO-H2O](+) for unsaturated wax esters containing only one double bond in the fatty acid moiety or with one additional double bond in the fatty alcohol moiety, and (3) [RCOOH2](+) and [RCO](+) for unsaturated wax esters containing a double bond in the fatty alcohol moiety alone. Other fragments included [R'](+) and several series of product ions for all types of wax esters. Interestingly, unusual product ions were detected, such as neutral molecule (including water, methanol and ammonia) adducts of [RCOOH2](+) ions for all types of wax esters and [R'-2H](+) ions for unsaturated fatty acyl-containing wax esters. The patterns of tandem mass spectra for different types of wax esters will inform future identification and quantification approaches of wax esters in biological samples as supported by a preliminary study of quantification of isomeric wax esters in human meibomian gland secretions.

Adenovirus Core Protein VII Protects the Viral Genome from a DNA Damage Response at Early Times after Infection▿

PubMed Central

Karen, Kasey A.; Hearing, Patrick

2011-01-01

Adenovirus has a linear, double-stranded DNA genome that is perceived by the cellular Mre11-Rad50-Nbs1 (MRN) DNA repair complex as a double-strand break. If unabated, MRN elicits a double-strand break repair response that blocks viral DNA replication and ligates the viral genomes into concatemers. There are two sets of early viral proteins that inhibit the MRN complex. The E1B-55K/E4-ORF6 complex recruits an E3 ubiquitin ligase and targets MRN proteins for proteasome-dependent degradation. The E4-ORF3 protein inhibits MRN through sequestration. The mechanism that prevents MRN recognition of the viral genome prior to the expression of these early proteins was previously unknown. Here we show a temporal correlation between the loss of viral core protein VII from the adenovirus genome and a gain of checkpoint signaling due to the double-strand break repair response. While checkpoint signaling corresponds to the recognition of the viral genome, core protein VII binding to and checkpoint signaling at viral genomes are largely mutually exclusive. Transcription is known to release protein VII from the genome, and the inhibition of transcription shows a decrease in checkpoint signaling. Finally, we show that the nuclease activity of Mre11 is dispensable for the inhibition of viral DNA replication during a DNA damage response. These results support a model involving the protection of the incoming viral genome from checkpoint signaling by core protein VII and suggest that the induction of an MRN-dependent DNA damage response may inhibit adenovirus replication by physically masking the origins of DNA replication rather than altering their integrity. PMID:21345950

Evidence of chaotic pattern in solar flux through a reproducible sequence of period-doubling-type bifurcations

NASA Technical Reports Server (NTRS)

Ashrafi, S.; Roszman, L.

1991-01-01

A preliminary study of the limits to solar flux intensity prediction, and of whether the general lack of predictability in the solar flux arises from the nonlinear chaotic nature of the Sun's physical activity is presented. Statistical analysis of a chaotic signal can extract only its most gross features, and detailed physical models fail, since even the simplest equations of motion for a nonlinear system can exhibit chaotic behavior. A recent theory by Feigenbaum suggests that nonlinear systems that can be led into chaotic behavior through a sequence of period-doubling bifurcations will exhibit a universal behavior. As the control parameter is increased, the bifurcation points occur in such a way that a proper ratio of these will approach the universal Feigenbaum number. Experimental evidence supporting the applicability of the Feigenbaum scenario to solar flux data is sparse. However, given the hypothesis that the Sun's convection zones are similar to a Rayleigh-Bernard mechanism, we can learn a great deal from the remarkable agreement observed between the prediction by theory (period doubling - a universal route to chaos) and the amplitude decrease of the signal's regular subharmonics. It is shown that period-doubling-type bifurcation is a possible route to a chaotic pattern of solar flux that is distinguishable from the logarithm of its power spectral density. This conclusion is the first positive step toward a reformulation of solar flux by a nonlinear chaotic approach. The ultimate goal of this research is to be able to predict an estimate of the upper and lower bounds for solar flux within its predictable zones. Naturally, it is an important task to identify the time horizons beyond which predictability becomes incompatible with computability.

Evidence of chaotic pattern in solar flux through a reproducible sequence of period-doubling-type bifurcations

NASA Technical Reports Server (NTRS)

Ashrafi, S.; Roszman, L.

1991-01-01

Presented here is a preliminary study of the limits to solar flux intensity prediction, and of whether the general lack of predictability in the solar flux arises from the nonlinear chaotic nature of the Sun's physical activity. Statistical analysis of a chaotic signal can extract only its most gross features, and detailed physical models fail, since even the simplest equations of motion for a nonlinear system can exhibit chaotic behavior. A recent theory by Feigenbaum suggests that nonlinear systems that can be led into chaotic behavior through a sequence of period-doubling bifurcations will exhibit a universal behavior. As the control parameter is increased, the bifurcation points occur in such a way that a proper ratio of these will approach the universal Feigenbaum number. Experimental evidence supporting the applicability of the Feigenbaum scenario to solar flux data is sparse. However, given the hypothesis that the Sun's convection zones are similar to a Rayleigh-Bernard mechanism, we can learn a great deal from the remarkable agreement observed between the prediction by theory (period doubling - a universal route to chaos) and the amplitude decrease of the signal's regular subharmonics. The authors show that period-doubling-type bifurcation is a possible route to a chaotic pattern of solar flux that is distinguishable from the logarithm of its power spectral density. This conclusion is the first positive step toward a reformulation of solar flux by a nonlinear chaotic approach. The ultimate goal of this research is to be able to predict an estimate of the upper and lower bounds for solar flux within its predictable zones. Naturally, it is an important task to identify the time horizons beyond which predictability becomes incompatible with computability.

Differences of Ballet Turns ("Pirouette") Performance between Experienced and Novice Ballet Dancers

ERIC Educational Resources Information Center

Lin, Chia-Wei; Chen, Shing-Jye; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

2014-01-01

Purpose: This study investigated the different postural control strategies exhibited by experienced and novice dancers in ballet turns ("pirouettes"). Method: Thirteen novice and 13 experienced dancers performed ballet turns with dominant-leg support. The peak push force was measured in the double-leg support phase. The inclination…

Simple and Double Alfven Waves: Hamiltonian Aspects

NASA Astrophysics Data System (ADS)

Webb, G. M.; Zank, G. P.; Hu, Q.; le Roux, J. A.; Dasgupta, B.

2011-12-01

We discuss the nature of simple and double Alfvén waves. Simple waves depend on a single phase variable \\varphi, but double waves depend on two independent phase variables \\varphi1 and \\varphi2. The phase variables depend on the space and time coordinates x and t. Simple and double Alfvén waves have the same integrals, namely, the entropy, density, magnetic pressure, and group velocity (the sum of the Alfvén and fluid velocities) are constant throughout the flow. We present examples of both simple and double Alfvén waves, and discuss Hamiltonian formulations of the waves.

Designing torus-doubling solutions to discrete time systems by hybrid projective synchronization

NASA Astrophysics Data System (ADS)

Xie, Hui; Wen, Guilin

2013-11-01

Doubling of torus occurs in high dimensional nonlinear systems, which is related to a certain kind of typical second bifurcations. It is a nontrivial task to create a torus-doubling solution with desired dynamical properties based on the classical bifurcation theories. In this paper, dead-beat hybrid projective synchronization is employed to build a novel method for designing stable torus-doubling solutions into discrete time systems with proper properties to achieve the purpose of utilizing bifurcation solutions as well as avoiding the possible conflict of physical meaning of the created solution. Although anti-controls of bifurcation and chaos synchronizations are two different topics in nonlinear dynamics and control, the results imply that it is possible to develop some new interdisciplinary methods between chaos synchronization and anti-controls of bifurcations.

Evolution of households’ responses to the groundwater arsenic crisis in Bangladesh: information on environmental health risks can have increasing behavioral impact over time

PubMed Central

Balasubramanya, Soumya; Pfaff, Alexander; Bennear, Lori; Tarozzi, Alessandro; Ahmed, Kazi Matin; Schoenfeld, Amy; van Geen, Alexander

2014-01-01

A national campaign of well testing through 2003 enabled households in rural Bangladesh to switch, at least for drinking, from high-arsenic wells to neighboring lower-arsenic wells. We study the well-switching dynamics over time by re-interviewing, in 2008, a randomly selected subset of households in the Araihazar region who had been interviewed in 2005. Contrary to concerns that the impact of arsenic information on switching behavior would erode over time, we find that not only was 2003–2005 switching highly persistent but also new switching by 2008 doubled the share of households at unsafe wells who had switched. The passage of time also had a cost: 22% of households did not recall test results by 2008. The loss of arsenic knowledge led to staying at unsafe wells and switching from safe wells. Our results support ongoing well testing for arsenic to reinforce this beneficial information. PMID:25383015

Flammable gas double shell tank expert elicitation presentations (Part A and Part B)

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

Bratzel, D.R.

1998-04-17

This document is a compilation of presentation packages and white papers for the Flammable Gas Double Shell Tank Expert Elicitation Workshop {number_sign}2. For each presentation given by the different authors, a separate section was developed. The purpose for issuing these workshop presentation packages and white papers as a supporting document is to provide traceability and a Quality Assurance record for future reference to these packages.

Action detection by double hierarchical multi-structure space-time statistical matching model

NASA Astrophysics Data System (ADS)

Han, Jing; Zhu, Junwei; Cui, Yiyin; Bai, Lianfa; Yue, Jiang

2018-03-01

Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space-time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space-time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances.

Action detection by double hierarchical multi-structure space–time statistical matching model

NASA Astrophysics Data System (ADS)

Han, Jing; Zhu, Junwei; Cui, Yiyin; Bai, Lianfa; Yue, Jiang

2018-06-01

Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space-time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space-time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances.

Experimenting with mixing and layered convection in phono-trachytic magmas: Implications on reservoir dynamics

NASA Astrophysics Data System (ADS)

de Campos, C. P.; Civetta, L.; Dingwell, D. B.; Perugini, D.; Petrelli, M.; Fehr, T. K.

2006-12-01

Abundant geochemical and volcanological data on the Campanian Ignimbrite, (>200 km3, 39 ka) Phlegrean Fields, Italy, support the existence of a layered magmatic reservoir, which evolved via 1) replenishment of the chamber with trachytic magma and 2) short-term pre-eruptive mixing between new trachytic and phono- trachytic resident magmas. We have initiated an experimental program in order to constrain the dynamics of such mingling/mixing events. We used melted natural products from these two magmas of sub-equal but distinct composition, which are thought to have been involved in the origin of this magmatic system as end-members (phono-trachyte = end- member A and trachyte = end-member B). The two were then stirred together and sampled by experiment termination as a time series, ranging from 1-hour up to 1-week. Stirring under constant low flow velocity (0.5 rotations per minute) generated at first homogenization and mixing of the starting compositions. Then separate convection cells and compositional layering for major and minor elements emerged. Calculated density distributions along sections from the experimental glasses, after decoupling, are very similar to density distributions in aqueous systems under double-diffusive convection. In order to test double- diffusive decoupled convection in this system, we performed 87Sr/86Sr-isotopic and Sr- LA-ICP-MS- measurements, using the 25-hour experimental glasses. The effective chemical separation of different convection cells has been confirmed with clearly distinct isotopic signatures for both bottom and top cells. Comparison with natural samples from the Campanian Ignimbrite strengthens the importance of the role of a double-diffusive similar convection as a major differentiation process leading to layering in this system. Our results support the effectiveness of a DDC-driven fractionation for moderately high-silica magmas under high near-liquidus temperatures, before the onset of fractional crystallization.

Characterizations of double pulsing in neutron multiplicity and coincidence counting systems

DOE PAGES

Koehler, Katrina E.; Henzl, Vladimir; Croft, Stephen; ...

2016-06-29

Passive neutron coincidence/multiplicity counters are subject to non-ideal behavior, such as double pulsing and dead time. It has been shown in the past that double-pulsing exhibits a distinct signature in a Rossi-alpha distribution, which is not readily noticed using traditional Multiplicity Shift Register analysis. But, it has been assumed that the use of a pre-delay in shift register analysis removes any effects of double pulsing. Here, we use high-fidelity simulations accompanied by experimental measurements to study the effects of double pulsing on multiplicity rates. By exploiting the information from the double pulsing signature peak observable in the Rossi-alpha distribution, themore » double pulsing fraction can be determined. Algebraic correction factors for the multiplicity rates in terms of the double pulsing fraction have been developed. We also discuss the role of these corrections across a range of scenarios.« less

Improved Electrochemical Cycling Durability in a Nickel Oxide Double-Layered Film.

PubMed

Hou, Shuai; Zhang, Xiang; Tian, Yanlong; Zhao, Jiupeng; Geng, Hongbin; Qu, Huiying; Zhang, Hangchuan; Zhang, Kun; Wang, Binsheng; Gavrilyuk, Alexander; Li, Yao

2017-11-16

For the first time, a crystalline-amorphous double-layered NiO x film has been prepared by reactive radio frequency magnetron sputtering. This film has exhibited improved electrochemical cycling durability, whereas other electrochromic parameters have been maintained at the required level, namely, a short coloration/bleaching time (0.8 s/1.1 s) and an enhanced transmittance modulation range (62.2 %) at λ=550 nm. Additionally, the double-layered film has shown better reversibility than that of amorphous and crystalline single-layered films. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pulse intensity characterization of the LCLS nanosecond double-bunch mode of operation

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

Sun, Yanwen; Decker, Franz-Josef; Turner, James

The recent demonstration of the 'nanosecond double-bunch' operation mode,i.e.two X-ray pulses separated in time between 0.35 and hundreds of nanoseconds and by increments of 0.35 ns, offers new opportunities to investigate ultrafast dynamics in diverse systems of interest. However, in order to reach its full potential, this mode of operation requires the precise characterization of the intensity of each X-ray pulse within each pulse pair for any time separation. Here, a transmissive single-shot diagnostic that achieves this goal for time separations larger than 0.7 ns with a precision better than 5% is presented. Lastly, it also provides real-time monitoring feedbackmore » to help tune the accelerator parameters to deliver double pulse intensity distributions optimized for specific experimental goals.« less

Pulse intensity characterization of the LCLS nanosecond double-bunch mode of operation

DOE PAGES

Sun, Yanwen; Decker, Franz-Josef; Turner, James; ...

2018-03-27

The recent demonstration of the 'nanosecond double-bunch' operation mode,i.e.two X-ray pulses separated in time between 0.35 and hundreds of nanoseconds and by increments of 0.35 ns, offers new opportunities to investigate ultrafast dynamics in diverse systems of interest. However, in order to reach its full potential, this mode of operation requires the precise characterization of the intensity of each X-ray pulse within each pulse pair for any time separation. Here, a transmissive single-shot diagnostic that achieves this goal for time separations larger than 0.7 ns with a precision better than 5% is presented. Lastly, it also provides real-time monitoring feedbackmore » to help tune the accelerator parameters to deliver double pulse intensity distributions optimized for specific experimental goals.« less

Servo Driven Corotation: Development of AN Inertial Clock.

NASA Astrophysics Data System (ADS)

Cheung, Wah-Kwan Stephen

An inertial clock to test non-metricity of gravity is proposed here. A first, room-temperature, servo corotation -protected, double magnetically suspended precision rotor system is developed for this purpose. The specific goal was to exhibit the properties of such a clock in its entirety at whatever level of precision was achievable. A monolithic system has been completed for these preliminary studies. It includes particular development of individual experimental sub-systems (a hybrid double magnetic suspension; a diffusion pumping system; a microcomputer -controlled eddy-current drive system; and the angular period measuring schemes for the doubly suspended rotors). Double magnetic suspension had been investigated by Beams for other purposes. The upper transducer is optical but parametrized and the lower transducer employs the frequency modulation characteristic of a LC tank circuit. The doubly suspended rotors corotate so that the upper rotor is servoed to rotate at the same angular velocity as that of the lower rotor. This creates a "drag free" environment for the lower rotor and effectively eliminates the gas drag on the lower rotor. Consequently, the decay time constant of the lower rotor increases. With other means of protection, the lower rotor will then, with perfect system operation, suffer no drag and therefore become the inertial time keeper. A commercial microcomputer is introduced to execute the servo-corotation. The tests thus far are, with one exception, run at atmospheric pressure. An idealized analysis for open and closed loop corotation is shown. Such analysis includes only the viscous drag acting on the corotating rotors. The analysis suggests that angular position control be added to the present feedback drive which is of derivative nature only. Open and closed corotation runs show that a strong torsional coupling besides that of the gas drag exists between the rotors. When misalignment of the support pole pieces is deliberately made significant, a stronger coupling between the rotors results. The coupling is suspected to be magnetic in nature. The complicated geometry of the double magnetic suspension scheme makes it difficult to evaluate the known mechanical cranking effect applied to this situation.

Motion of the center of mass in children with spastic hemiplegia: balance, energy transfer, and work performed by the affected leg vs. the unaffected leg.

PubMed

Feng, Jing; Pierce, Rosemary; Do, K Patrick; Aiona, Michael

2014-01-01

Asymmetry between limbs in people with spastic hemiplegic cerebral palsy (HEMI) adversely affects limb coordination and energy generation and consumption. This study compared how the affected leg and the unaffected leg of children with HEMI would differ based on which leg trails. Full-body gait analysis data and force-plate data were analyzed for 31 children (11.9 ± 3.8 years) with HEMI and 23 children (11.1 ± 3.1 years) with typical development (TD). Results showed that peak posterior center of mass-center of pressure (COM-COP) inclination angles of HEMI were smaller than TD when the affected leg trailed but not when the unaffected leg trailed. HEMI showed greater peak medial COM-COP inclination angles and wider step width than TD, no matter which leg trailed. More importantly, when the affected leg of HEMI trailed, it did not perform enough positive work during double support to propel COM motion. Consequently, the unaffected leg had to perform additional positive work during the early portion of single support, which costs more energy. When the unaffected leg trailed, the affected leg performed more negative work during double support; therefore, more positive work was still needed during early single support, but energy efficiency was closer to that of TD. Energy recovery factor was lower when the affected leg trailed than when the unaffected leg trailed; both were lower than TD. These findings suggest that the trailing leg plays a significant role in propelling COM motion during double support, and the 'unaffected' side of HEMI may not be completely unaffected. It is important to strengthen both legs. Copyright © 2013 Elsevier B.V. All rights reserved.

Local concurrent error detection and correction in data structures using virtual backpointers

NASA Technical Reports Server (NTRS)

Li, C. C.; Chen, P. P.; Fuchs, W. K.

1987-01-01

A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data structures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared databased of Virtual Double Linked Lists.

Local concurrent error detection and correction in data structures using virtual backpointers

NASA Technical Reports Server (NTRS)

Li, Chung-Chi Jim; Chen, Paul Peichuan; Fuchs, W. Kent

1989-01-01

A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data strutures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared database of Virtual Double Linked Lists.

Evaluation of the Comet Assay for Assessing the Dose-Response Relationship of DNA Damage Induced by Ionizing Radiation

PubMed Central

Wang, Yan; Xu, Chang; Du, Li Qing; Cao, Jia; Liu, Jian Xiang; Su, Xu; Zhao, Hui; Fan, Fei-Yue; Wang, Bing; Katsube, Takanori; Fan, Sai Jun; Liu, Qiang

2013-01-01

Dose- and time-response curves were combined to assess the potential of the comet assay in radiation biodosimetry. The neutral comet assay was used to detect DNA double-strand breaks in lymphocytes caused by γ-ray irradiation. A clear dose-response relationship with DNA double-strand breaks using the comet assay was found at different times after irradiation (p < 0.001). A time-response relationship was also found within 72 h after irradiation (p < 0.001). The curves for DNA double-strand breaks and DNA repair in vitro of human lymphocytes presented a nice model, and a smooth, three-dimensional plane model was obtained when the two curves were combined. PMID:24240807

Pressure RElieving Support SUrfaces: a Randomised Evaluation 2 (PRESSURE 2): study protocol for a randomised controlled trial.

PubMed

Brown, Sarah; Smith, Isabelle L; Brown, Julia M; Hulme, Claire; McGinnis, Elizabeth; Stubbs, Nikki; Nelson, E Andrea; Muir, Delia; Rutherford, Claudia; Walker, Kay; Henderson, Valerie; Wilson, Lyn; Gilberts, Rachael; Collier, Howard; Fernandez, Catherine; Hartley, Suzanne; Bhogal, Moninder; Coleman, Susanne; Nixon, Jane E

2016-12-20

Pressure ulcers represent a major burden to patients, carers and the healthcare system, affecting approximately 1 in 17 hospital and 1 in 20 community patients. They impact greatly on an individual's functional status and health-related quality of life. The mainstay of pressure ulcer prevention practice is the provision of pressure redistribution support surfaces and patient repositioning. The aim of the PRESSURE 2 study is to compare the two main mattress types utilised within the NHS: high-specification foam and alternating pressure mattresses, in the prevention of pressure ulcers. PRESSURE 2 is a multicentre, open-label, randomised, double triangular, group sequential, parallel group trial. A maximum of 2954 'high-risk' patients with evidence of acute illness will be randomised on a 1:1 basis to receive either a high-specification foam mattress or alternating-pressure mattress in conjunction with an electric profiling bed frame. The primary objective of the trial is to compare mattresses in terms of the time to developing a new Category 2 or above pressure ulcer by 30 days post end of treatment phase. Secondary endpoints include time to developing new Category 1 and 3 or above pressure ulcers, time to healing of pre-existing Category 2 pressure ulcers, health-related quality of life, cost-effectiveness, incidence of mattress change and safety. Validation objectives are to determine the responsiveness of the Pressure Ulcer Quality of Life-Prevention instrument and the feasibility of having a blinded endpoint assessment using photography. The trial will have a maximum of three planned analyses with unequally spaced reviews at event-driven coherent cut-points. The futility boundaries are constructed as non-binding to allow a decision for stopping early to be overruled by the Data Monitoring and Ethics Committee. The double triangular, group sequential design of the PRESSURE 2 trial will provide an efficient design through the possibility of early stopping for demonstrating either superiority, inferiority of mattresses or futility of the trial. The trial optimises the potential for producing robust clinical evidence on the effectiveness of two commonly used mattresses in clinical practice earlier than in a conventional design. ISRCTN01151335 . Registered on 14 May 2013. Protocol version: 5.0, dated 25 September 2015 Trial sponsor: Clare Skinner, Faculty Head of Research Support, University of Leeds, Leeds, LS2 9JT; 0113 343 4897; C.E.Skinner@leeds.ac.uk.

Carbon Redox-Polymer-Gel Hybrid Supercapacitors.

PubMed

Vlad, A; Singh, N; Melinte, S; Gohy, J-F; Ajayan, P M

2016-02-26

Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances.

Enhanced activity of CaFeMg layered double hydroxides-supported gold nanodendrites for the electrochemical evolution of oxygen and hydrogen in alkaline media

NASA Astrophysics Data System (ADS)

Havakeshian, Elaheh; Salavati, Hossein; Taei, Masoumeh; Hasheminasab, Fatemeh; Seddighi, Mohadeseh

2018-02-01

In this study, Au was electrodeposited on a support of CaFeMg layered double hydroxide and then, its catalytic activity was investigated for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Field emission scanning electron microscopy images showed that a uniform porous film of aggregated nano-particles of the LDH has been decorated with Au nanodendrite-like structures (AuNDs@LDH). The results obtained from polarization curves, Tafel plots and electrochemical impedance spectroscopy showed that the AuNDs@LDH exhibits lower overpotential, higher current density, faster kinetics and enhanced stability for both of the OER and HER, in comparison with the single AuNPs and LDH catalysts.

English Language Support for Engineering Students and Professors

NASA Astrophysics Data System (ADS)

Teshigawara, Mihoko

The University of Tokushima Graduate School of Advanced Technology and Science has launched the International Affiliated Double-Degree Program. In this program students pursue double degrees in engineering at the graduate level organized between the Graduate School and one of its 11 overseas partner institutions. Since the Graduate School is committed to offering content lectures in English, the faculty members involved need a good command of English. Future outgoing students also have to improve their English (and the local language spoken at the partner institution) to conduct academic activities at the partner institution successfully. This paper describes the author‧s continuing efforts toward the provision and improvement of English language support for engineering students and instructors, touching on similar activities elsewhere.

Long-term outcomes and risk factors of biliary stent dysfunction after endoscopic double stenting for malignant biliary and duodenal obstructions.

PubMed

Matsumoto, Kazuyuki; Kato, Hironari; Tsutsumi, Koichiro; Mizukawa, Sho; Yabe, Syuntaro; Seki, Hiroyuki; Akimoto, Yutaka; Uchida, Daisuke; Tomoda, Takeshi; Yamamoto, Naoki; Horiguchi, Shigeru; Kuwaki, Kenji; Okada, Hiroyuki

2017-07-01

Few reports describe the endoscopic double-stenting procedure for malignant biliary and duodenal obstructions. We evaluated the clinical outcomes from double stenting, and analyzed the risk factors for biliary stent dysfunction following double stenting. Eighty-one patients who underwent endoscopic double stenting for malignant biliary and duodenal obstructions were retrospectively analyzed. We determined the stent dysfunction rate and the biliary stent dysfunction risk factors, and analyzed the endoscopic reintervention results. Overall survival time and survival time following double stenting were 365 (38-1673) days and 73 (20-954) days, respectively. After double stenting, the 3-month and 6-month duodenal stent dysfunction rates were 14% and 41%, respectively. Reintervention technical success rate was 100% (10/10), and mean gastric outlet obstruction scoring system scores improved from 0.7 to 2.4 points (P < 0.001). The 3-month and 6-month biliary stent dysfunction rates were 26% and 41%, respectively. The reintervention technical and clinical success rates were 95% (20/21) and 81% (17/21), respectively. Risk factors for biliary stent dysfunction following double stenting were events associated with duodenal stent dysfunction (odds ratio [OR], 11.1; 95% confidence interval [CI], 2.09-87.4; P = 0.0044) and the biliary stent end's location (OR, 6.93; 95% CI, 1.37-40.2; P = 0.0019). Some patients had stent dysfunction irrespective of the survival period after double stenting. Endoscopic reintervention was technically feasible and clinically effective even after double stenting. Duodenal stent dysfunction and biliary stent end's location were risk factors for biliary stent dysfunction. © 2017 Japan Gastroenterological Endoscopy Society.

Activities and Achievements of the Double Star Committee of the Socié té Astronomique de France

NASA Astrophysics Data System (ADS)

Agati, Jean-Louis; Caille, Sébastien; Debackère, André; Durand, Pierre; Losse, Florent; Manté, René; Mauroy, Florence; Mauroy, Pascal; Morlet, Guy; Pinlou, Claude; Salaman, Maurice; Soulié, Edgar; Thorel, Yvonne; Thorel, Jean-Claude

2007-08-01

In a synthesis article (see ref. below), the double star expert Paul COUTEAU put the work of French pioneers of double stars observation in the perspective of the double star work carried in the world. After Antoine Yvon VILLARCEAU and Camille FLAMMARION, one prominent pioneer of double stars was Robert JONCKHEERE (1888toiles Doubles, Maurice DURUY (1894le with a 40-cm and later a 60-cm telescope at Le Rouret (Alpes1995) had started the measurement of double stars as an amateur. He was granted permission to measure them with the 38-cm of the Paris Observatory and made an impressive number of measures during his long 2006) made double star observations for the book which was then in preparation under the title La revue des constellations. Their measures remained unpublished; but publication of the measures made by Robert SAGOT is in preparation. At about the same time, the neurology professor Jacques LE BEAU (1908toiles doubles visuelles. That book triggered the interest of more amateur astronomers for double stars and indirectly influenced the creation of a group of double star observers which was transformed into the Commission des É toiles Doubles

Cell Size Regulation in Bacteria

NASA Astrophysics Data System (ADS)

Amir, Ariel

2014-05-01

Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

Children's multiplicative transformations of discrete and continuous quantities.

PubMed

Barth, Hilary; Baron, Andrew; Spelke, Elizabeth; Carey, Susan

2009-08-01

Recent studies have documented an evolutionarily primitive, early emerging cognitive system for the mental representation of numerical quantity (the analog magnitude system). Studies with nonhuman primates, human infants, and preschoolers have shown this system to support computations of numerical ordering, addition, and subtraction involving whole number concepts prior to arithmetic training. Here we report evidence that this system supports children's predictions about the outcomes of halving and perhaps also doubling transformations. A total of 138 kindergartners and first graders were asked to reason about the quantity resulting from the doubling or halving of an initial numerosity (of a set of dots) or an initial length (of a bar). Controls for dot size, total dot area, and dot density ensured that children were responding to the number of dots in the arrays. Prior to formal instruction in symbolic multiplication, division, or rational number, halving (and perhaps doubling) computations appear to be deployed over discrete and possibly continuous quantities. The ability to apply simple multiplicative transformations to analog magnitude representations of quantity may form a part of the toolkit that children use to construct later concepts of rational number.

The structure of poly(carbonsuboxide) on the atomic scale: a solid-state NMR study.

PubMed

Schmedt auf der Günne, Jörn; Beck, Johannes; Hoffbauer, Wilfried; Krieger-Beck, Petra

2005-07-18

In this contribution we present a study of the structure of amorphous poly(carbonsuboxide) (C3O2)x by 13C solid-state NMR spectroscopy supported by infrared spectroscopy and chemical analysis. Poly(carbonsuboxide) was obtained by polymerization of carbonsuboxide C3O2, which in turn was synthesized from malonic acid bis(trimethylsilylester). Two different 13C labeling schemes were applied to probe inter- and intramonomeric bonds in the polymer by dipolar solid-state NMR methods and also to allow quantitative 13C MAS NMR spectra. Four types of carbon environments can be distinguished in the NMR spectra. Double-quantum and triple-quantum 2D correlation experiments were used to assign the observed peaks using the through-space and through-bond dipolar coupling. In order to obtain distance constraints for the intermonomeric bonds, double-quantum constant-time experiments were performed. In these experiments an additional filter step was applied to suppress contributions from not directly bonded 13C,13C spin pairs. The 13C NMR intensities, chemical shifts, connectivities and distances gave constraints for both the polymerization mechanism and the short-range order of the polymer. The experimental results were complemented by bond lengths predicted by density functional theory methods for several previously suggested models. Based on the presented evidence we can unambiguously exclude models based on gamma-pyronic units and support models based on alpha-pyronic units. The possibility of planar ladder- and bracelet-like alpha-pyronic structures is discussed.

Senators breathe new life into efforts to double federal dollars for R&D

NASA Astrophysics Data System (ADS)

Folger, Peter

At a press conference held Thursday, June 25, Senator Bill Frist (R-Tenn.) announced that he and Senator Jay Rockefeller (D-W.Va.) were introducing a bill to double federal support for research and development (R&D) over the next 12 years.This latest development gives a boost to legislation introduced last October by Senators Phil Gramm (R-Tex.) and Joe Lieberman (D-Conn.) to double R&D spending in a decade. The earlier bill, numbered S. 1305, garnered only 18 Senate cosponsors in 8 months and appears to be mired in the Labor and Human Resources Committee with little hope of moving to the Senate floor.

Delusion of inanimate doubles: description of a case of focal retrograde amnesia.

PubMed

Abbate, Carlo; Trimarchi, Pietro Davide; Salvi, Gian Pietro; Quarenghi, Anna Maria; Vergani, Carlo; Luzzatti, Claudio

2012-01-01

This paper reports the case of a patient, M.P., who developed delusion of inanimate doubles, without Capgras syndrome, after traumatic brain injury. His delusional symptoms were studied longitudinally and the cognitive impairments associated with delusion were investigated. Data suggest that M.P. did 'perceive' the actual differences between doubles and originals rather than 'confabulate' them. The cognitive profile, characterized by retrograde episodic amnesia, but neither object processing impairment nor confabulations, supports this hypothesis. The study examines the nature of object misidentification based on Ellis' and Staton's account and proposes a new account based on concurrent unbiased retrieval of semantic memory traces and biased recollection of episodic memory traces.

Planar Lattice Instability in LA2CUO4.1 across the Superconducting Transition

NASA Astrophysics Data System (ADS)

Acosta-Alejandro, Manuel; Mustre-de Leon, Jose; Conradson, Steven

2001-03-01

The local atomic structure of La2CuO4.1 around Cu K-edge is analyzed for 10

Individuality and universality in the growth-division laws of single E. coli cells

NASA Astrophysics Data System (ADS)

Kennard, Andrew S.; Osella, Matteo; Javer, Avelino; Grilli, Jacopo; Nghe, Philippe; Tans, Sander J.; Cicuta, Pietro; Cosentino Lagomarsino, Marco

2016-01-01

The mean size of exponentially dividing Escherichia coli cells in different nutrient conditions is known to depend on the mean growth rate only. However, the joint fluctuations relating cell size, doubling time, and individual growth rate are only starting to be characterized. Recent studies in bacteria reported a universal trend where the spread in both size and doubling times is a linear function of the population means of these variables. Here we combine experiments and theory and use scaling concepts to elucidate the constraints posed by the second observation on the division control mechanism and on the joint fluctuations of sizes and doubling times. We found that scaling relations based on the means collapse both size and doubling-time distributions across different conditions and explain how the shape of their joint fluctuations deviates from the means. Our data on these joint fluctuations highlight the importance of cell individuality: Single cells do not follow the dependence observed for the means between size and either growth rate or inverse doubling time. Our calculations show that these results emerge from a broad class of division control mechanisms requiring a certain scaling form of the "division hazard rate function," which defines the probability rate of dividing as a function of measurable parameters. This "model free" approach gives a rationale for the universal body-size distributions observed in microbial ecosystems across many microbial species, presumably dividing with multiple mechanisms. Additionally, our experiments show a crossover between fast and slow growth in the relation between individual-cell growth rate and division time, which can be understood in terms of different regimes of genome replication control.

A Pilot Study of the Impact of Double-Dose Robust Vocabulary Instruction on Children's Vocabulary Growth

ERIC Educational Resources Information Center

Arthur, Ann M.; Davis, Dawn L.

2016-01-01

Double-dose instruction, in which instructional lessons are supplemented to provide additional instructional time, is a mechanism used in some schools for boosting outcomes in certain academic areas. The purpose of this study was to examine the effects of double-dose vocabulary instruction, relative to single-dose and business-as-usual control…

Classification of Double Deficit Groups across Time: An Analysis of Group Stability from Kindergarten to Second Grade

ERIC Educational Resources Information Center

Steacy, Laura M.; Kirby, John R.; Parrila, Rauno; Compton, Donald L.

2014-01-01

The Double Deficit Hypothesis of dyslexia is one approach to classifying students with reading disabilities. The theory offers four distinct groups of readers: (a) average readers, (b) students with phonological deficits, (c) students with naming speed deficits, and (d) students with double deficits: those having both (b) and (c). This study…

The effectiveness of cut-proof glove liners: cut and puncture resistance, dexterity, and sensibility.

PubMed

Salkin, J A; Stuchin, S A; Kummer, F J; Reininger, R

1995-11-01

Five types of commercial glove liners (within double latex gloves) were compared to single and double latex gloves for cut and puncture resistance and for relative manual dexterity and degree of sensibility. An apparatus was constructed to test glove-pseudofinger constructs in either a cutting or puncture mode. Cutting forces, cutting speed, and type of blade (serrated or scalpel blade) were varied and the time to cut-through measured by an electrical conductivity circuit. Penetration forces were similarly determined with a scalpel blade and a suture needle using a spring scale loading apparatus. Dexterity was measured with an object placement task among a group of orthopedic surgeons. Sensibility was assessed with Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry using standard techniques and rating scales. A subjective evaluation was performed at the end of testing. Time to cut-through for the liners ranged from 2 to 30 seconds for a rapid oscillating scalpel and 4 to 40 seconds for a rapid oscillating serrated knife under minimal loads. When a 1 kg load was added, times to cut-through ranged from 0.4 to 1.0 second. In most cases, the liners were superior to double latex. On average, 100% more force was required to penetrate the liners with a scalpel and 50% more force was required to penetrate the liners with a suture needle compared to double latex. Object placement task times were not significantly liners compared to double latex gloves. Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry showed no difference in sensibility among the various liners and double latex gloves. Subjects felt that the liners were minimally to moderately impairing. An acclimation period may be required for their effective use.

31P NMR spectroscopy studies of phospholipid metabolism in human melanoma xenograft lines differing in rate of tumour cell proliferation.

PubMed

Lyng, H; Olsen, D R; Petersen, S B; Rofstad, E K

1995-04-01

The concentration of phospholipid metabolites in tumours has been hypothesized to be related to rate of cell membrane turnover and may reflect rate of cell proliferation. The purpose of the study reported here was to investigate whether 31P NMR resonance ratios involving the phosphomonoester (PME) or phosphodiester (PDE) resonance are correlated to fraction of cells in S-phase or volume-doubling time in experimental tumours. Four human melanoma xenograft lines (BEX-t, HUX-t, SAX-t, WIX-t) were included in the study. The tumours were grown subcutaneously in male BALB/c-nu/nu mice. 31P NMR spectroscopy was performed at a magnetic field strength of 4.7 T. Fraction of cells in S-phase was measured by flow cytometry. Tumour volume-doubling time was determined by Gompertzian analysis of volumetric growth data. BEX-t and SAX-t tumours differed in fraction of cells in S-phase and volume-doubling time, but showed similar 31P NMR resonance ratios. BEX-t and WIX-t tumours showed significantly different 31P NMR resonance ratios but similar fractions of cells in S-phase. The 31P NMR resonance ratios were significantly different for small and large HUX-t tumours even though fraction of cells in S-phase and volume-doubling time did not differ with tumour volume. None of the 31P NMR resonance ratios showed significant increase with increasing fraction of cells in S-phase or significant decrease with increasing tumour volume-doubling time across the four xenograft lines.(ABSTRACT TRUNCATED AT 250 WORDS)

The growth rate of bone sarcomas and survival after radiotherapy with tourniquet-induced hypoxia: a clinical study. [/sup 60/Co

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

Balmukhanov, S.B.; Turdugulov, I.; Karibjanova, Z.

1982-04-15

The volume doubling time of primary bone sarcomas and lung metastases was determined by measurements made on serial radiographs. For the primary tumors, the volume doubling times were lognormal distributed and varied in the range of 20-200 days with a mean around 50 days. The volume doubling times of the metastases also showed a log-normal distribution in the range of 10-100 days, but with a mean twice as short as that of the primaries. Radiation therapy was given with three-four doses of 20-25 Gy to the tumors that, together with the surrounding normal tissues, had been made hypoxic by themore » application of a tourniquet. Amputations were not performed unless required eventually by some serious late radiation damage, such as grave functional deficiency, and/or painful fibrosis and ankyloses. In no case did microscopic examination of the amputated tissues reveal the persistance of any viable, neoplastic cell. The five-year survival of a total of 69 patients was 26%. Survival expectancy was found to be closely related to the volume doubling time of the tumors, as was the incidence of the metastases. The data stress the importance of volume doubling time as a predictive factor and indicate, furthermore, that treatment with a few massive radiation doses in combination with tourniquet-induced hypoxia is effective in the local control of bone sarcomas. The severe late reaction of the normal tissues to the treatment will, however, require amputations in most of the five-year survivors.« less

Time-dependent electrophoresis of a dielectric spherical particle embedded in Brinkman medium

NASA Astrophysics Data System (ADS)

Saad, E. I.; Faltas, M. S.

2018-04-01

An expression for electrophoretic apparent velocity slip in the time-dependent flow of an electrolyte solution saturated in a charged porous medium within an electric double layer adjacent to a dielectric plate under the influence of a tangential uniform electric field is derived. The velocity slip is used as a boundary condition to solve the electrophoretic motion of an impermeable dielectric spherical particle embedded in an electrolyte solution saturated in porous medium under the unsteady Darcy-Brinkman model. Throughout the system, a uniform electric field is applied and maintains with constant strength. Two cases are considered, when the electric double layer enclosing the particle is thin, but finite and when of a particle with a thick double layer. Expressions for the electrophoretic mobility of the particle as functions of the relevant parameters are found. Our results indicate that the time scale for the growth of mobility is significant and small for high permeability. Generally, the effect of the relaxation time for starting electrophoresis is negligible, irrespective of the thickness of the double layer and permeability of the medium. The effects of the elapsed time, permeability, mass density and Debye length parameters on the fluid velocity, the electrophoretic mobility and the acceleration are shown graphically.

The 2011 Draconids: The First European Airborne Meteor Observation Campaign

NASA Astrophysics Data System (ADS)

Vaubaillon, Jeremie; Koten, Pavel; Margonis, Anastasios; Toth, Juraj; Rudawska, Regina; Gritsevich, Maria; Zender, Joe; McAuliffe, Jonathan; Pautet, Pierre-Dominique; Jenniskens, Peter; Koschny, Detlef; Colas, Francois; Bouley, Sylvain; Maquet, Lucie; Leroy, Arnaud; Lecacheux, Jean; Borovicka, Jiri; Watanabe, Junichi; Oberst, Jürgen

2015-02-01

On 8 October 2011, the Draconid meteor shower (IAU, DRA) was predicted to cause two brief outbursts of meteors, visible from locations in Europe. For the first time, a European airborne meteor observation campaign was organized, supported by ground-based observations. Two aircraft were deployed from Kiruna, Sweden, carrying six scientists, 19 cameras and eight crew members. The flight geometry was chosen such that it was possible to obtain double-station observations of many meteors. The instrument setup on the aircraft as well as on the ground is described in full detail. The main peak from 1900-dust ejecta happened at the predicted time and at the predicted rate. The second peak was observed from the earlier flight and from the ground, and was caused most likely by trails ejected in the nineteenth century. A total of 250 meteors were observed, for which light curve data were derived. The trajectory, velocity, deceleration and orbit of 35 double station meteors were measured. The magnitude distribution index was high, as a result of which there was no excess of meteors near the horizon. The light curve proved to be extremely flat on average, which was unexpected. Observations of spectra allowed us to derive the compositional information of the Draconids meteoroids and showed an early release of sodium, usually interpreted as resulting from fragile meteoroids. Lessons learned from this experience are derived for future airborne meteor shower observation campaigns.

Radiation-induced chromosomal instability in BALB/c and C57BL/6 mice: the difference is as clear as black and white

NASA Technical Reports Server (NTRS)

Ponnaiya, B.; Cornforth, M. N.; Ullrich, R. L.

1997-01-01

Genomic instability has been proposed to be the earliest step in radiation-induced tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-induced instability. BALB/c white mice are considerably more sensitive to radiation-induced mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the "delayed" appearance of chromosomal aberrations after exposure to 137Cs gamma radiation, as a measure of radiation-induced genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of chromatid-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of chromatid-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-induced instability in the process of tumorigenesis.

New Double-Periodic Soliton Solutions for the (2+1)-Dimensional Breaking Soliton Equation

NASA Astrophysics Data System (ADS)

Liu, Jian-Guo; Tian, Yu

2018-05-01

Under investigation is the (2+1)-dimensional breaking soliton equation. Based on a special ansätz functions and the bilinear form, some entirely new double-periodic soliton solutions for the (2+1)-dimensional breaking soliton equation are presented. With the help of symbolic computation software Mathematica, many important and interesting properties for these obtained solutions are revealed with some figures. Supported by National Natural Science Foundation of China under Grant No. 61377067

Spatial-temporal parameters of gait in women with fibromyalgia.

PubMed

Heredia Jiménez, José María; Aparicio García-Molina, Virginia A; Porres Foulquie, Jesús M; Delgado Fernández, Manuel; Soto Hermoso, Victor M

2009-05-01

The aim of the present study was to determine if there are differences in such parameters among patients affected by fibromyalgia (FM) and healthy subjects and whether the degree of affectation by FM can decrease the gait parameters. We studied 55 women with FM and 44 controls. Gait analysis was performed using an instrumented walkway for measurement of the kinematic parameters of gait (GAITRite system), and patients completed a Spanish version of Fibromyalgia Impact Questionnaire (FIQ). Significant differences (p < 0.001) between FM and control groups were found in velocity, stride length, cadence, single support ratio, double support ratio, stance phase ratio, and swing phase ratio. There were significant inverse correlations between FIQ and velocity, stride length, swing phase, and single support, whereas significant direct correlations were found with stance phase and double support. Gait parameters of women affected by FM were severely impaired when compared to those of healthy women. Different factors such as lack of physical activity, bradikinesia, overweight, fatigue, and pain together with a lower isometric force in the legs can be responsible for the alterations in gait and poorer life quality of women with FM.

Computational study of the shift of the G band of double-walled carbon nanotubes due to interlayer interactions

NASA Astrophysics Data System (ADS)

Popov, Valentin N.; Levshov, Dmitry I.; Sauvajol, Jean-Louis; Paillet, Matthieu

2018-04-01

The interactions between the layers of double-walled carbon nanotubes induce a measurable shift of the G bands relative to the isolated layers. While experimental data on this shift in freestanding double-walled carbon nanotubes has been reported in the past several years, a comprehensive theoretical description of the observed shift is still lacking. The prediction of this shift is important for supporting the assignment of the measured double-walled nanotubes to particular nanotube types. Here, we report a computational study of the G-band shift as a function of the semiconducting inner layer radius and interlayer separation. We find that with increasing interlayer separation, the G band shift decreases, passes through zero and becomes negative, and further increases in absolute value for the wide range of considered inner layer radii. The theoretical predictions are shown to agree with the available experimental data within the experimental uncertainty.

Capture of SO3 isomers in the oxidation of sulfur monoxide with molecular oxygen.

PubMed

Wu, Zhuang; Lu, Bo; Feng, Ruijuan; Xu, Jian; Lu, Yan; Wan, Huabin; Eckhardt, André K; Schreiner, Peter R; Xie, Changjian; Guo, Hua; Zeng, Xiaoqing

2018-02-13

When mixing SO with O 2 in N 2 , Ne, or Ar, an end-on complex OS-OO forms in the gas phase and can subsequently be trapped at cryogenic temperatures (2.8-15.0 K). Upon infrared light irradiation, OS-OO converts to SO 3 and SO 2 + O with the concomitant formation of a rare 1,2,3-dioxathiirane 2-oxide, i.e., cyclic OS([double bond, length as m-dash]O)O. Unexpectedly, the ring-closure of 16 OS- 18 O 18 O yields a ca. 2 : 1 mixture of cyclic 18 OS([double bond, length as m-dash] 16 O) 18 O and 16 OS([double bond, length as m-dash] 18 O) 18 O. The characterization of OS-OO and OS([double bond, length as m-dash]O)O with IR and UV/Vis spectroscopy is supported by high-level ab initio computations.

Current-voltage characteristics of double stranded versus single stranded DNA molecules

NASA Astrophysics Data System (ADS)

Hartzell, B.; Chen, Hong; Heremans, J. J.; McCord, B.; Soghomonian, V.

2004-03-01

Investigation of DNA conductivity has focused on the native, duplex structure, with controversial results. Here, we present the influence of the double-helical structure on charge transport through lambda DNA molecules. The current-voltage (I-V) characteristics of both disulfide-labeled double stranded DNA (dsDNA) and disulfide-labeled single stranded DNA (ssDNA) were measured. The ssDNA was formed from the dsDNA using two different methods for comparison purposes: a thermal/chemical denaturation and enzymatic digestion utilizing lambda exonuclease. Resulting I-V characteristics of both the double stranded and single stranded samples were close-to-linear when measured at room temperature. However, the ssDNA samples consistently gave conductivity values about two orders of magnitude smaller in amplitude. Our results suggest an integral relationship between the native structure of DNA with its stacked base pairs and the molecule's ability to support charge transport.(NSF NIRT 0103034)

Recollision induced excitation-ionization with counter-rotating two-color circularly polarized laser field

NASA Astrophysics Data System (ADS)

Ben, Shuai; Guo, Pei-Ying; Pan, Xue-Fei; Xu, Tong-Tong; Song, Kai-Li; Liu, Xue-Shen

2017-07-01

Nonsequential double ionization of Ar by a counter-rotating two-color circularly polarized laser field is theoretically investigated. At the combined intensity in the "knee" structure range, the double ionization occurs mainly through recollision induced excitation followed by subsequent ionization of Ar+∗ . By tracing the history of the recollision trajectories, we explain how the relative intensity ratio of the two colors controls the correlated electron dynamics and optimizes the ionization yields. The major channels contributing to enhancing the double ionization are through the elliptical trajectories with smaller travel time but not through the triangle shape or the other long cycle trajectories. Furthermore, the correlated electron dynamics could be limited to the attosecond time scale by adjusting the relative intensity ratio. Finally, the double ionization from doubly excited complex at low laser intensity is qualitatively discussed.

Filtration performance of microporous ceramic supports.

PubMed

Belouatek, Aissa; Ouagued, Abdellah; Belhakem, Mustapha; Addou, Ahmed

2008-04-24

The use of inorganic membranes in pollution treatment is actually limited by the cost of such membranes. Advantages of inorganic membranes are their chemical, thermal and pH properties. The purpose of this work was the development of microporous ceramic materials based on clay for liquid waste processing. The supports or ceramic filters having various compositions were prepared and thermally treated at 1100 degrees C. The results show that, at the temperature studied, porosity varied according to the support composition from 12% for the double-layered (ceramic) support to 47% for the activated carbon- filled support with a mean pore diameter between 0.8 and 1.3 microm, respectively. Volumes of 5 l of distilled water were filtered tangentially for 3 h under an applied pressure of 3.5 and 5.5 bar. The retention of tubular supports prepared was tested with molecules of varying size (Evans blue, NaCl and Sacharose). The study of the liquid filtration and flow through these supports showed that the retention rate depends on support composition and pore diameter, and solute molecular weight. The S1 support (mixture of barbotine and 1% (w/w) activated carbon) gave a flux for distilled water of 68 L/m2 h while the double-layered support resulted in a flux of 8 L/m2 h for the same solution at the pressure of 3.5 bar. At a pressure of 5.5 bar an increase in the distilled water flux through the various supports was observed. It was significant for the S1 support (230 L/m h).

Double layers in expanding plasmas and their relevance to the auroral plasma processes

NASA Astrophysics Data System (ADS)

Singh, Nagendra; Khazanov, George

2003-04-01

When a dense plasma consisting of a cold and a sufficiently warm electron population expands, a rarefaction shock forms [, 1978]. In the expansion of the polar wind in the magnetosphere, it has been previously shown that when a sufficiently warm electron population also exists, in addition to the usual cold ionospheric one, a discontinuity forms in the electrostatic potential distribution along the magnetic field lines [, 1984]. Despite the lack of spatial resolution and the assumption of quasi-neutrality in the polar wind models, such discontinuities have been called double layers (DLs). Recently similar discontinuities have been invoked to partly explain the auroral acceleration of electrons and ions in the upward current region [, 2000]. By means of one-dimensional Vlasov simulations of expanding plasmas, for the first time we make here the connection between (1) the rarefaction shocks, (2) the discontinuities in the potential distributions, and (3) DLs. We show that when plasmas expand from opposite directions into a deep density cavity with a potential drop across it and when the plasma on the high-potential side contains hot and cold electron populations, the temporal evolution of the potential and the plasma distribution generates evolving multiple double layers with an extended density cavity between them. One of the DLs is the rarefaction-shock (RFS) and it forms by the reflections of the cold electrons coming from the high-potential side; it supports a part of the potential drop approximately determined by the hot electron temperature. The other DLs evolve from charge separations arising either from reflection of ions coming from the low-potential side or stemming from plasma instabilities; they support the rest of the potential drop. The instabilities forming these additional double layers involve electron-ion (e-i) Buneman or ion-ion (i-i) two-stream interactions. The electron-electron two-stream interactions on the high-potential side of the RFS generate electron-acoustic waves, which evolve into electron phase-space holes. The ion population originating from the low-potential side and trapped by the RFS is energized by the e-i and i-i instabilities and it eventually precipitates into the high-potential plasma along with an electron beam. Applications of these findings to the auroral plasma physics are discussed.

Double Layers in Expanding Plasmas and Their Relevance to the Auroral Plasma Processes

NASA Technical Reports Server (NTRS)

Singh, Nagendra; Khazanov, George

2003-01-01

When a dense plasma consisting of a cold and a sufficiently warm electron population expands, a rarefaction shock forms [Bezzerides et al., 1978]. In the expansion of the polar wind in the magnetosphere, it has been previously shown that when a sufficiently warm electron population also exists, in addition to the usual cold ionospheric one, a discontinuity forms in the electrostatic potential distribution along the magnetic field lines [Barakat and Schunk, 1984]. Despite the lack of spatial resolution and the assumption of quasi-neutrality in the polar wind models, such discontinuities have been called double layers (DLs). Recently similar discontinuities have been invoked to partly explain the auroral acceleration of electrons and ions in the upward current region [Ergun et al., 2000]. By means of one-dimensional Vlasov simulations of expanding plasmas, for the first time we make here the connection between (1) the rarefaction shocks, (2) the discontinuities in the potential distributions, and (3) DLs. We show that when plasmas expand from opposite directions into a deep density cavity with a potential drop across it and when the plasma on the high-potential side contains hot and cold electron populations, the temporal evolution of the potential and the plasma distribution generates evolving multiple double layers with an ,extended density cavity between them. One of the DLs is the rarefaction-shock (RFS) and it forms by the reflections of the cold electrons coming from the high-potential side; it supports a part of the potential drop approximately determined by the hot electron temperature. The other DLs evolve from charge separations arising either from reflection of ions coming from the low-potential side or stemming from plasma instabilities; they support the rest of the potential drop. The instabilities forming these additional double layers involve electron-ion (e-i) Buneman or ion-ion (i-i) two-stream interactions. The electron-electron two-stream interactions on the high-potential side of the RFS generate electron-acoustic waves, which evolve into electron phase-space holes. The ion population originating from the low-potential side and trapped by the RFS is energized by the e-i and i-i instabilities and it eventually precipitates into the high-potential plasma along with an electron beam. Applications of these findings to the auroral plasma physics are discussed.

An efficient algorithm for double-difference tomography and location in heterogeneous media, with an application to the Kilauea volcano

USGS Publications Warehouse

Monteiller, V.; Got, J.-L.; Virieux, J.; Okubo, P.

2005-01-01

Improving our understanding of crustal processes requires a better knowledge of the geometry and the position of geological bodies. In this study we have designed a method based upon double-difference relocation and tomography to image, as accurately as possible, a heterogeneous medium containing seismogenic objects. Our approach consisted not only of incorporating double difference in tomography but also partly in revisiting tomographic schemes for choosing accurate and stable numerical strategies, adapted to the use of cross-spectral time delays. We used a finite difference solution to the eikonal equation for travel time computation and a Tarantola-Valette approach for both the classical and double-difference three-dimensional tomographic inversion to find accurate earthquake locations and seismic velocity estimates. We estimated efficiently the square root of the inverse model's covariance matrix in the case of a Gaussian correlation function. It allows the use of correlation length and a priori model variance criteria to determine the optimal solution. Double-difference relocation of similar earthquakes is performed in the optimal velocity model, making absolute and relative locations less biased by the velocity model. Double-difference tomography is achieved by using high-accuracy time delay measurements. These algorithms have been applied to earthquake data recorded in the vicinity of Kilauea and Mauna Loa volcanoes for imaging the volcanic structures. Stable and detailed velocity models are obtained: the regional tomography unambiguously highlights the structure of the island of Hawaii and the double-difference tomography shows a detailed image of the southern Kilauea caldera-upper east rift zone magmatic complex. Copyright 2005 by the American Geophysical Union.

Doubling Time for Nonexponential Families of Functions

ERIC Educational Resources Information Center

Gordon, Sheldon P.

2010-01-01

One special characteristic of any exponential growth or decay function f(t) = Ab[superscript t] is its unique doubling time or half-life, each of which depends only on the base "b". The half-life is used to characterize the rate of decay of any radioactive substance or the rate at which the level of a medication in the bloodstream decays as it is…

Selectivity of Electronic Coherence and Attosecond Ionization Delays in Strong-Field Double Ionization

NASA Astrophysics Data System (ADS)

Kobayashi, Yuki; Reduzzi, Maurizio; Chang, Kristina F.; Timmers, Henry; Neumark, Daniel M.; Leone, Stephen R.

2018-06-01

Experiments are presented on real-time probing of coherent electron dynamics in xenon initiated by strong-field double ionization. Attosecond transient absorption measurements allow for characterization of electronic coherences as well as relative ionization timings in multiple electronic states of Xe+ and Xe2 + . A high degree of coherence g =0.4 is observed between P3 2 0-P3 0 0 of Xe2 + , whereas for other possible pairs of states the coherences are below the detection limits of the experiments. A comparison of the experimental results with numerical simulations based on an uncorrelated electron-emission model shows that the coherences produced by strong-field double ionization are more selective than predicted. Surprisingly short ionization time delays, 0.85 fs, 0.64 fs, and 0.75 fs relative to Xe+ formation, are also measured for the P2 3 , P0 3 , and P1 3 states of Xe2 + , respectively. Both the unpredicted selectivity in the formation of coherence and the subfemtosecond time delays of specific states provide new insight into correlated electron dynamics in strong-field double ionization.

Dynamic behavior of a magnetic bearing supported jet engine rotor with auxiliary bearings

NASA Technical Reports Server (NTRS)

Homaifar, Abdollah (Editor); Kelly, John C., Jr. (Editor); Flowers, G. T.; Xie, H.; Sinha, S. C.

1994-01-01

This paper presents a study of the dynamic behavior of a rotor system supported by auxiliary bearings. The steady-state behavior of a simulation model based upon a production jet engine is explored over a wide range of operating conditions for varying rotor imbalance, support stiffness and damping. Interesting dynamical phenomena, such as chaos, subharmonic responses, and double-valued responses, are presented and discussed.

Dynamic behavior of a magnetic bearing supported jet engine rotor with auxiliary bearings

NASA Technical Reports Server (NTRS)

Flowers, George T.; Xie, Huajun; Sinha, S. C.

1995-01-01

This paper presents a study of the dynamic behavior of a rotor system supported by auxiliary bearings. The steady-state behavior of a simulation model based upon a production jet engine is explored over a wide range of operating conditions for varying rotor imbalance, support stiffness, and damping. Interesting dynamical phenomena, such as chaos, subharmonic responses, and double-valued responses, are presented and discussed.

Luteal Phase Support in the Intrauterine Insemination (IUI) Cycles: A Randomized Double Blind, Placebo Controlled Study

PubMed Central

Hossein Rashidi, Batool; Davari Tanha, Fatemeh; Rahmanpour, Haleh; Ghazizadeh, Mahya

2014-01-01

Objective: To evaluate the impact of luteal phase support with vaginal progesterone on pregnancy rates in the intrauterine insemination (IUI) cycles, stimulated with clomiphene citrate and human menopausal gonadotropin (hMG), in sub fertile couples. Materials and methods: This prospective, randomized, double blind study was performed in a tertiary infertility center from March 2011 to January 2012. It consisted of 253 sub fertile couples undergoing ovarian stimulation for IUI cycles. They underwent ovarian stimulation with clomiphene citrate (100 mg) and hMG (75 IU) in preparation for the IUI cycle. Study group (n = 127) received luteal phase support in the form of vaginal progesterone (400 mg twice a day), and control group (n = 126) received placebo. Clinical pregnancy and abortion rates were assessed and compared between the two groups. Results: The clinical pregnancy rate was not significantly higher for supported cycles than that for the unsupported ones (15.75% vs. 12.69%, p = 0.3). The abortion rate in the patients with progesterone luteal support compared to placebo group was not statistically different (10% vs. 18.75%, p = 0.45). Conclusion: It seems that luteal phase support with vaginal progesterone was not enhanced the success of IUI cycles outcomes, when clomiphene citrate and hMG were used for ovulation stimulation. PMID:25530766

Research advisory board members' contributions and expectations in the USA.

PubMed

Pinto, R M; Spector, Anya Y; Rahman, R; Gastolomendo, J D

2015-06-01

This study focuses on the Implementation Community Collaborative Board (I-CCB) to identify members' anticipated contributions to and returns from the I-CCB; examine whether or not members achieved these contributions and returns over time; and explore barriers and facilitators that influenced accomplishments. Longitudinal study with repeated semi-structured in-depth interviews; baseline captured anticipated contributions and returns; 6- and 18-month follow-ups short- and longer-term achievements. We used content analysis to code/reduce text into variables, describe, count and compare categories. Participants anticipated involvement in I-CCB dynamics/governance and in research tasks/procedures. Anticipated returns included social support. Participants exerting influence on I-CCB's research agenda stayed the same over time. Participants conducting research doubled between follow-ups; those writing grant proposals increased by 50%. Participants receiving emotional support remained the same. Challenges: meetings steered by researchers; lack of time; use of jargon. Facilitators: outreaching to community; being affected by HIV; having overlapping identities/roles as researcher, service consumer and/or practitioner. Research partners can maximize facilitators, redress barriers and improve advisory board members' retention. Findings may help optimize the functioning of advisory boards worldwide. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Scaling of Average Weighted Receiving Time on Double-Weighted Koch Networks

NASA Astrophysics Data System (ADS)

Dai, Meifeng; Ye, Dandan; Hou, Jie; Li, Xingyi

2015-03-01

In this paper, we introduce a model of the double-weighted Koch networks based on actual road networks depending on the two weight factors w,r ∈ (0, 1]. The double weights represent the capacity-flowing weight and the cost-traveling weight, respectively. Denote by wFij the capacity-flowing weight connecting the nodes i and j, and denote by wCij the cost-traveling weight connecting the nodes i and j. Let wFij be related to the weight factor w, and let wCij be related to the weight factor r. This paper assumes that the walker, at each step, starting from its current node, moves to any of its neighbors with probability proportional to the capacity-flowing weight of edge linking them. The weighted time for two adjacency nodes is the cost-traveling weight connecting the two nodes. We define the average weighted receiving time (AWRT) on the double-weighted Koch networks. The obtained result displays that in the large network, the AWRT grows as power-law function of the network order with the exponent, represented by θ(w,r) = ½ log2(1 + 3wr). We show that the AWRT exhibits a sublinear or linear dependence on network order. Thus, the double-weighted Koch networks are more efficient than classic Koch networks in receiving information.

Label-free CMOS bio sensor with on-chip noise reduction scheme for real-time quantitative monitoring of biomolecules.

PubMed

Seong-Jin Kim; Euisik Yoon

2012-06-01

We present a label-free CMOS field-effect transistor sensing array to detect the surface potential change affected by the negative charge in DNA molecules for real-time monitoring and quantification. The proposed CMOS bio sensor includes a new sensing pixel architecture implemented with correlated double sampling for reducing offset fixed pattern noise and 1/f noise of the sensing devices. We incorporated non-surface binding detection which allows real-time continuous monitoring of DNA concentrations without immobilizing them on the sensing surface. Various concentrations of 19-bp oligonucleotides solution can be discriminated using the prototype device fabricated in 1- μm double-poly double-metal standard CMOS process. The detection limit was measured as 1.1 ng/μl with a dynamic range of 40 dB and the transient response time was measured less than 20 seconds.

Maintenance of longitudinal foot arch after different mid/hind-foot arthrodesis procedures in a cadaveric model.

PubMed

Chen, Yanxi; Zhang, Kun; Qiang, Minfei; Hao, Yini

2014-02-01

Currently, the optimal treatment of flatfoot remains inconclusive. Our objectives were to understand the effect of different arthrodeses on maintenance of foot arch and provide experimental basis for rational selection in treatment of flatfoot. Sixteen fresh-frozen cadaver feet amputated above the ankle along with a section of leg were studied from ten males and six females. We used standard clinical techniques and hardware for making the arthrodeses. Plantar pressure in the medial and lateral longitudinal arch distribution was measured with a plantar pressure mapping system under different loading conditions. Values of plantar pressure reaction, mean and maximum dynamic peak pressure between all group pairs were statistically significant (P<0.05). The plantar pressure reaction appeared at the load of 960 N in the medial arch of the unoperated foot, compared with 1080 N after subtalar arthrodesis, 1200 N after talonavicular arthrodesis, 1080 N after calcaneocuboid arthrodesis, 1320 N after double arthrodesis, and 1560 N after triple arthrodesis. The plantar pressure reaction appeared at the load of 360 N in the lateral arch of the unoperated foot, compared with 600 N after subtalar arthrodesis, 600 N after talonavicular arthrodesis, 840 N after calcaneocuboid arthrodesis, 960 N after double arthrodesis, and 1440 N after triple arthrodesis. The triple arthrodesis provided the highest support to both arches; the double arthrodesis appeared to be similar to talonavicular arthrodesis in supporting the medial arch and similar to calcaneocuboid arthrodesis in supporting the lateral arch; subtalar arthrodesis was less effective in supporting both arches. Copyright © 2013 Elsevier Ltd. All rights reserved.

Immobilization of endo-polygalacturonase from Aspergillus niger on various types of macromolecular supports.

PubMed

Pifferi, P G; Tramontini, M; Malacarne, A

1989-04-20

Endo-polygalacturonase (endo-PG) was immobilized on a wide range of natural and synthetic macromolecular supports and their modified derivatives representing many chemical classes, including esters, amides, phenols, alkyl- and arylamines, and carboxyl derivatives. The immobilization entailed methods of adsorption alone as well as covalent bond formation using glutaraldehyde or carbodiimide or via the diazo-coupling reaction. The most promising system proved to be immobilization on trimalehylchitosan (TMC) via adsorption followed by treatment with glutaraldehyde (GA). The binding capacity of the support is on the order of 13,000 IU/g, half of which is active. Various properties of immobilized endo-PG were evaluated. The optimum pH of the enzyme shifted to the alkaline side. The relative catalytic activity was considerably high even at room temperature and remained so above 70 degrees C. The thermal stability at pH 3-4 was notably improved by immobilization, the half-time doubling. Finally, the apparent K(m) was greater for immobilized endo-PG than for native enzyme, while the V(max) was smaller for the immobilized enzyme.

Reducing errors through a web-based self-management support system.

PubMed

Ekstedt, Mirjam; Børøsund, Elin; Svenningsen, Ina K; Ruland, Cornelia M

2014-01-01

Web-based self-management support systems SMSS, can successfully assist a wide range of patients with information and self-management support. O or as a stand-alone service, are e-messages. This study describes how one component of a multi component SMSS, an e-message service, in which patients with breast cancer could direct questions to nurses, physicians or social workers at the hospital where they were being treated, had an influence on safety and continuity of care. Ninety-one dialogues consisting of 284 messages were analysed. The communications between patients and the healthcare team revealed that the e-messages service served as a means for quality assurance of information, for double-checking and for coordination of care. We give examples of how an e-mail service may improve patients' knowledge in a process of taking control over their own care - increasingly important in a time of growing complexity and specialization in healthcare. It remains to be tested whether an e-message service can improve continuity of care and prevent or mitigate medical mishaps.

Scintillating fibres coupled to silicon photomultiplier prototypes for fast beam monitoring and thin timing detectors

NASA Astrophysics Data System (ADS)

Papa, A.; Kettle, P.-R.; Ripiccini, E.; Rutar, G.

2016-07-01

Several scintillating fibre prototypes (single- and double-layers) made of 250 μm multi-clad square fibres coupled to silicon photomultiplier have been studied using electrons, positrons and muons at different energies. Current measurements show promising results: already for a single fibre layer and minimum ionizing particles we obtain a detection efficiency ≥ 95 % (mean collected light/fibre ≈ 8 phe), a timing resolution of 550 ps/fibre and a foreseen spatial resolution < 100 μm, based on the achieved negligible optical cross-talk between fibres (< 1 %). We will also discuss the performances of a double-layer staggered prototype configuration, for which a full detection efficiency (≥ 99 %) has been measured together with a timing resolution of ≈ 400 ps for double hit events.

The mechanism of double-exponential growth in hyper-inflation

NASA Astrophysics Data System (ADS)

Mizuno, T.; Takayasu, M.; Takayasu, H.

2002-05-01

Analyzing historical data of price indices, we find an extraordinary growth phenomenon in several examples of hyper-inflation in which, price changes are approximated nicely by double-exponential functions of time. In order to explain such behavior we introduce the general coarse-graining technique in physics, the Monte Carlo renormalization group method, to the price dynamics. Starting from a microscopic stochastic equation describing dealers’ actions in open markets, we obtain a macroscopic noiseless equation of price consistent with the observation. The effect of auto-catalytic shortening of characteristic time caused by mob psychology is shown to be responsible for the double-exponential behavior.

2.5-D poroelastic wave modelling in double porosity media

NASA Astrophysics Data System (ADS)

Liu, Xu; Greenhalgh, Stewart; Wang, Yanghua

2011-09-01

To approximate seismic wave propagation in double porosity media, the 2.5-D governing equations of poroelastic waves are developed and numerically solved. The equations are obtained by taking a Fourier transform in the strike or medium-invariant direction over all of the field quantities in the 3-D governing equations. The new memory variables from the Zener model are suggested as a way to represent the sum of the convolution integrals for both the solid particle velocity and the macroscopic fluid flux in the governing equations. By application of the memory equations, the field quantities at every time step need not be stored. However, this approximation allows just two Zener relaxation times to represent the very complex double porosity and dual permeability attenuation mechanism, and thus reduce the difficulty. The 2.5-D governing equations are numerically solved by a time-splitting method for the non-stiff parts and an explicit fourth-order Runge-Kutta method for the time integration and a Fourier pseudospectral staggered-grid for handling the spatial derivative terms. The 2.5-D solution has the advantage of producing a 3-D wavefield (point source) for a 2-D model but is much more computationally efficient than the full 3-D solution. As an illustrative example, we firstly show the computed 2.5-D wavefields in a homogeneous single porosity model for which we reformulated an analytic solution. Results for a two-layer, water-saturated double porosity model and a laterally heterogeneous double porosity structure are also presented.

Double Magnetic Reconnection Driven by Kelvin-Helmholtz Vortices

NASA Astrophysics Data System (ADS)

Horton, W., Jr.; Faganello, M.; Califano, F.; Pegoraro, F.

2017-12-01

Simulations and theory for the solar wind driven magnetic reconnection in the flanks of the magnetopause is shown to be intrinsically 3D with the secular growth of couple pairs of reconnection regions off the equatorial plane. We call the process double mid-latitude reconnection and show supporting 3D simulations and theory descripting the secular growth of the magnetic reconnection with the resulting mixing of the solar wind plasma with the magnetosphere plasma. The initial phase develops Kelvin-Helmholtz vortices at low-latitude and, through the propagation of Alfven waves far from the region where the stresses are generated, creates a standard quasi-2D low latitude boundary layer magnetic reconnection but off the equatorial plane and with a weak guide field component. The reconnection exponential growth is followed by a secularly growing nonlinear phase that gradually closes the solar wind field lines on the Earth. The nonlinear field line structure provides a channel for penetration of the SW plasma into the MS as observed by spacecraft [THEMIS and Cluster]. The simulations show the amount of solar wind plasma brought into the magnetosphere by tracing the time evolution of the areas corresponding to double reconnected field lines with Poincare maps. The results for the solar wind plasma brought into the magnetosphere seems consistent with the observed plasma transport. Finally, we have shown how the intrinsic 3D nature of the doubly reconnected magnetic field lines leads to the generation of twisted magnetic spatial structures that differ from the quasi-2D magnetic islands structures.

Characterization of the COD removal, electricity generation, and bacterial communities in microbial fuel cells treating molasses wastewater.

PubMed

Lee, Yun-Yeong; Kim, Tae G; Cho, Kyung-Suk

2016-11-09

The chemical oxygen demand (COD) removal, electricity generation, and microbial communities were compared in 3 types of microbial fuel cells (MFCs) treating molasses wastewater. Single-chamber MFCs without and with a proton exchange membrane (PEM), and double-chamber MFC were constructed. A total of 10,000 mg L(-1) COD of molasses wastewater was continuously fed. The COD removal, electricity generation, and microbial communities in the two types of single-chamber MFCs were similar, indicating that the PEM did not enhance the reactor performance. The COD removal in the single-chamber MFCs (89-90%) was higher than that in the double-chamber MFC (50%). However, electricity generation in the double-chamber MFC was higher than that in the single-chamber MFCs. The current density (80 mA m(-2)) and power density (17 mW m(-2)) in the double-chamber MFC were 1.4- and 2.2-times higher than those in the single-chamber MFCs, respectively. The bacterial community structures in single- and double-chamber MFCs were also distinguishable. The amount of Proteobacteria in the double-chamber MFC was 2-3 times higher than those in the single-chamber MFCs. For the archaeal community, Methanothrix (96.4%) was remarkably dominant in the single-chamber MFCs, but Methanobacterium (35.1%), Methanosarcina (28.3%), and Methanothrix (16.2%) were abundant in the double-chamber MFC.

Atomoxetine Increased Effect over Time in Adults with Attention-Deficit/Hyperactivity Disorder Treated for up to 6 Months: Pooled Analysis of Two Double-Blind, Placebo-Controlled, Randomized Trials.

PubMed

Wietecha, Linda A; Clemow, David B; Buchanan, Andrew S; Young, Joel L; Sarkis, Elias H; Findling, Robert L

2016-07-01

Changes in the magnitude of efficacy throughout 26 weeks of atomoxetine treatment, along with impact of dosing, were evaluated in adults with ADHD from two randomized, double-blind, placebo-controlled studies. Pooled placebo (n = 485) and atomoxetine (n = 518) patients, dosed 25, 40, 60, 80 (target dose), or 100 mg daily, were assessed. Change from baseline in Conners' Adult ADHD Rating Scale-Investigator Rated Scale: Screening Version (CAARS) total ADHD symptoms score and Adult ADHD Investigator Symptom Rating Scale (AISRS) total score were analyzed using mixed-model repeated measures, with least squares mean change, effect size, and response rate calculated at 1, 2, 4, 8, 12, 16, 22, and 26 weeks. Decreases on CAARS for atomoxetine- versus placebo-treated patients were consistently statistically significantly greater at every time point beginning at one week (P ≤ 0.006, 0.28 effect size). By 4 weeks, comparison was -13.19 compared with -8.84 (P < 0.0001, 0.45 effect size). By 26 weeks, mean change was -15.42 versus -9.71 (0.52 effect size); increase in effect size over time was most pronounced in the 80 mg group (0.82 effect size). AISRS demonstrated similar results. Atomoxetine response rate (CAARS 50% decrease) continued to increase throughout 26 weeks. Atomoxetine treatment in adults with ADHD was associated with small effect sizes after 4 weeks and moderate effect sizes by 6 months of treatment. The data support increased effect size and response rate over time during longer-term treatment at target dose. © 2016 Eli Lilly and Company. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.

Paediatric nurses' adherence to the double-checking process during medication administration in a children's hospital: an observational study.

PubMed

Alsulami, Zayed; Choonara, Imti; Conroy, Sharon

2014-06-01

To evaluate how closely double-checking policies are followed by nurses in paediatric areas and also to identify the types, frequency and rates of medication administration errors that occur despite the double-checking process. Double-checking by two nurses is an intervention used in many UK hospitals to prevent or reduce medication administration errors. There is, however, insufficient evidence to either support or refute the practice of double-checking in terms of medication error risk reduction. Prospective observational study. This was a prospective observational study of paediatric nurses' adherence to the double-checking process for medication administration from April-July 2012. Drug dose administration events (n = 2000) were observed. Independent drug dose calculation, rate of administering intravenous bolus drugs and labelling of flush syringes were the steps with lowest adherence rates. Drug dose calculation was only double-checked independently in 591 (30%) drug administrations. There was a statistically significant difference in nurses' adherence rate to the double-checking steps between weekdays and weekends in nine of the 15 evaluated steps. Medication administration errors (n = 191) or deviations from policy were observed, at a rate of 9·6% of drug administrations. These included 64 drug doses, which were left for parents to administer without nurse observation. There was variation between paediatric nurses' adherence to double-checking steps during medication administration. The most frequent type of administration errors or deviation from policy involved the medicine being given to the parents to administer to the child when the nurse was not present. © 2013 John Wiley & Sons Ltd.

Energy levels of double triangular graphene quantum dots

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

Liang, F. X.; Jiang, Z. T., E-mail: ztjiang616@hotmail.com; Zhang, H. Y.

2014-09-28

We investigate theoretically the energy levels of the coupled double triangular graphene quantum dots (GQDs) based on the tight-binding Hamiltonian model. The double GQDs including the ZZ-type, ZA-type, and AA-type GQDs with the two GQDs having the zigzag or armchair boundaries can be coupled together via different interdot connections, such as the direct coupling, the chains of benzene rings, and those of carbon atoms. It is shown that the energy spectrum of the coupled double GQDs is the amalgamation of those spectra of the corresponding two isolated GQDs with the modification triggered by the interdot connections. The interdot connection ismore » inclined to lift up the degeneracies of the energy levels in different degree, and as the connection changes from the direct coupling to the long chains, the removal of energy degeneracies is suppressed in ZZ-type and AA-type double GQDs, which indicates that the two coupled GQDs are inclined to become decoupled. Then we consider the influences on the spectra of the coupled double GQDs induced by the electric fields applied on the GQDs or the connection, which manifests as the global spectrum redistribution or the local energy level shift. Finally, we study the symmetrical and asymmetrical energy spectra of the double GQDs caused by the substrates supporting the two GQDs, clearly demonstrating how the substrates affect the double GQDs' spectrum. This research elucidates the energy spectra of the coupled double GQDs, as well as the mechanics of manipulating them by the electric field and the substrates, which would be a significant reference for designing GQD-based devices.« less

Double ionization in R -matrix theory using a two-electron outer region

NASA Astrophysics Data System (ADS)

Wragg, Jack; Parker, J. S.; van der Hart, H. W.

2015-08-01

We have developed a two-electron outer region for use within R -matrix theory to describe double ionization processes. The capability of this method is demonstrated for single-photon double ionization of He in the photon energy region between 80 and 180 eV. The cross sections are in agreement with established data. The extended R -matrix with time dependence method also provides information on higher-order processes, as demonstrated by the identification of signatures for sequential double ionization processes involving an intermediate He+ state with n =2 .

X-ray Photoelectron Spectroscopy Analysis of Gold Surfaces after Removal of Thiolated DNA Oligomers by Ultraviolet/Ozone Treatment

PubMed Central

Mirsaleh-Kohan, Nasrin; Bass, Andrew D.; Sanche, Léon

2012-01-01

Well ordered films of molecular DNA can be formed by the attachment of thiolated DNA oligonucleotides to a supporting gold substrate. The gold substrate represents a significant fraction of the total cost of preparing such films and it is thus important to determine whether such substrates can be reused. Here we investigate with X-ray Photoelectron Spectroscopy the suitability of UV/ozonolysis previously employed to remove alkanethiols from gold, for removing 40-mer, single and double stranded synthetic DNA. We find that while UV/O3 can indeed remove thiolated DNA from gold slides, the treatment times required permit the implantation of additional organic contaminants. PMID:20000594

X-ray photoelectron spectroscopy analysis of gold surfaces after removal of thiolated DNA oligomers by ultraviolet/ozone treatment.

PubMed

Mirsaleh-Kohan, Nasrin; Bass, Andrew D; Sanche, Léon

2010-05-04

Well-ordered films of molecular DNA can be formed by the attachment of thiolated DNA oligonucleotides to a supporting gold substrate. The gold substrate represents a significant fraction of the total cost of preparing such films, and it is thus important to determine whether such substrates can be reused. Here, we investigate with X-ray photoelectron spectroscopy the suitability of UV/ozonolysis previously employed to remove alkanethiols from gold, for removing 40-mer, single- and double-stranded synthetic DNA. We find that while UV/O(3) can indeed remove thiolated DNA from gold slides, the treatment times required permit the implantation of additional organic contaminants.

The double-deficit hypothesis: a comprehensive analysis of the evidence.

PubMed

Vukovic, Rose K; Siegel, Linda S

2006-01-01

The double-deficit hypothesis of developmental dyslexia proposes that deficits in phonological processing and naming speed represent independent sources of dysfunction in dyslexia. The present article is a review of the evidence for the double-deficit hypothesis, including a discussion of recent findings related to the hypothesis. Studies in this area have been characterized by variability in methodology--how dyslexia is defined and identified, and how dyslexia subtypes are classified. Such variability sets limitations on the extent to which conclusions may be drawn with respect to the double-deficit hypothesis. Furthermore, the literature is complicated by the persistent finding that measures of phonological processing and naming speed are significantly correlated, resulting in a statistical artifact that makes it difficult to disentangle the influence of naming speed from that of phonological processing. Longitudinal and intervention studies of the double-deficit hypothesis are needed to accumulate evidence that investigates a naming speed deficit that is independent of a phonological deficit for readers with dyslexia. The existing evidence does not support a persistent core deficit in naming speed for readers with dyslexia.

Conformational changes in fragments D and double-D from human fibrin(ogen) upon binding the peptide ligand Gly-His-Arg-Pro-amide.

PubMed

Everse, S J; Spraggon, G; Veerapandian, L; Doolittle, R F

1999-03-09

The structure of fragment double-D from human fibrin has been solved in the presence and absence of the peptide ligands that simulate the two knobs exposed by the removal of fibrinopeptides A and B, respectively. All told, six crystal structures have been determined, three of which are reported here for the first time: namely, fragments D and double-D with the peptide GHRPam alone and double-D in the absence of any peptide ligand. Comparison of the structures has revealed a series of conformational changes that are brought about by the various knob-hole interactions. Of greatest interest is a moveable "flap" of two negatively charged amino acids (Glubeta397 and Aspbeta398) whose side chains are pinned back to the coiled coil with a calcium atom bridge until GHRPam occupies the beta-chain pocket. Additionally, in the absence of the peptide ligand GPRPam, GHRPam binds to the gamma-chain pocket, a new calcium-binding site being formed concomitantly.

Gold Nanoparticles Supported on a Layered Double Hydroxide as Efficient Catalysts for the One-Pot Synthesis of Flavones.

PubMed

Yatabe, Takafumi; Jin, Xiongjie; Yamaguchi, Kazuya; Mizuno, Noritaka

2015-11-02

Flavones are a class of natural products with diverse biological activities and have frequently been synthesized by step-by-step procedures using stoichiometric amounts of reagents. Herein, a catalytic one-pot procedure for the synthesis of flavone and its derivatives is developed. In the presence of gold nanoparticles supported on a Mg-Al layered double hydroxide (Au/LDH), various kinds of flavones can be synthesized starting from 2'-hydroxyacetophenones and benzaldehydes (or benzyl alcohols). The present one-pot procedure consists of a sequence of several reactions, and Au/LDH can catalyze all these different types of reactions. The catalysis is shown to be truly heterogeneous, and Au/LDH can be readily recovered and reused. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon Redox-Polymer-Gel Hybrid Supercapacitors

PubMed Central

Vlad, A.; Singh, N.; Melinte, S.; Gohy, J.-F.; Ajayan, P.M.

2016-01-01

Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances. PMID:26917470

Load to Failure and Stiffness

PubMed Central

Esquivel, Amanda O.; Duncan, Douglas D.; Dobrasevic, Nikola; Marsh, Stephanie M.; Lemos, Stephen E.

2015-01-01

Background: Rotator cuff tendinopathy is a frequent cause of shoulder pain that can lead to decreased strength and range of motion. Failures after using the single-row technique of rotator cuff repair have led to the development of the double-row technique, which is said to allow for more anatomical restoration of the footprint. Purpose: To compare 5 different types of suture patterns while maintaining equality in number of anchors. The hypothesis was that the Mason-Allen–crossed cruciform transosseous-equivalent technique is superior to other suture configurations while maintaining equality in suture limbs and anchors. Study Design: Controlled laboratory study. Methods: A total of 25 fresh-frozen cadaveric shoulders were randomized into 5 suture configuration groups: single-row repair with simple stitch technique; single-row repair with modified Mason-Allen technique; double-row Mason-Allen technique; double-row cross-bridge technique; and double-row suture bridge technique. Load and displacement were recorded at 100 Hz until failure. Stiffness and bone mineral density were also measured. Results: There was no significant difference in peak load at failure, stiffness, maximum displacement at failure, or mean bone mineral density among the 5 suture configuration groups (P < .05). Conclusion: According to study results, when choosing a repair technique, other factors such as number of sutures in the repair should be considered to judge the strength of the repair. Clinical Relevance: Previous in vitro studies have shown the double-row rotator cuff repair to be superior to the single-row repair; however, clinical research does not necessarily support this. This study found no difference when comparing 5 different repair methods, supporting research that suggests the number of sutures and not the pattern can affect biomechanical properties. PMID:26665053

Stabilization and analytical tuning rule of double-loop control scheme for unstable dead-time process

NASA Astrophysics Data System (ADS)

Ugon, B.; Nandong, J.; Zang, Z.

2017-06-01

The presence of unstable dead-time systems in process plants often leads to a daunting challenge in the design of standard PID controllers, which are not only intended to provide close-loop stability but also to give good performance-robustness overall. In this paper, we conduct stability analysis on a double-loop control scheme based on the Routh-Hurwitz stability criteria. We propose to use this unstable double-loop control scheme which employs two P/PID controllers to control first-order or second-order unstable dead-time processes typically found in process industries. Based on the Routh-Hurwitz stability necessary and sufficient criteria, we establish several stability regions which enclose within them the P/PID parameter values that guarantee close-loop stability of the double-loop control scheme. A systematic tuning rule is developed for the purpose of obtaining the optimal P/PID parameter values within the established regions. The effectiveness of the proposed tuning rule is demonstrated using several numerical examples and the result are compared with some well-established tuning methods reported in the literature.

The Decline of the Military Ethos and Profession of Arms: An Argument Against Autonomous Lethal Engagements

DTIC Science & Technology

2012-10-01

very limited to support near-term, clear-cut, small-scale tactical objectives avoiding mass applications which could compromise long term strategic...principles of double effect and double intent factor into the calculus of the use of force as well.26 The professional community is divided on the...lethal force and those who prosecute it and a lack of empathy for those who it is waged upon.54 Finally, Hartle writes that one purpose of professional

A Double-Blind, Randomized Pilot Trial of Chromium Picolinate for Overweight Individuals with Binge-Eating Disorder: Effects on Glucose Regulation.

PubMed

Sala, Margarita; Breithaupt, Lauren; Bulik, Cynthia M; Hamer, Robert M; La Via, Maria C; Brownley, Kimberly A

2017-03-04

Chromium treatment has been shown to improve glucose regulation in some populations. The purpose of this study was to evaluate whether chromium picolinate (CrPic) supplementation improves glucose regulation in overweight individuals with binge-eating disorder (BED). In this double-blinded randomized pilot trial, participants (N = 24) were randomized to high (HIGH, 1000 mcg/day, n = 8) or moderate (MOD, 600 mcg/day, n = 9) dose of CrPic or placebo (PL, n = 7) for 6 months. Participants completed an oral glucose tolerance test (OGTT) at baseline, 3 months, and 6 months. Fixed effects models were used to estimate mean change in glucose area under the curve (AUC), insulin AUC , and insulin sensitivity index (ISI). Results revealed a significant group and time interaction (p < 0.04) for glucose AUC , with glucose AUC increasing significantly in the PL group (p < 0.02) but decreasing significantly in the MOD group (p < 0.03) at 6 months. Insulin AUC increased significantly over time (main effect, p < 0.02), whereas ISI decreased significantly over time (main effect, p < 0.03). As anticipated, a moderate dose of CrPic was associated with improved glycemic control, whereas PL was associated with decreased glycemic control. It was unexpected that the improved glycemic control seen in the MOD dose group was not seen in the HIGH dose group. However, although participants randomized to the HIGH dose group did not have improved glycemic control, they had better glycemic control than participants randomized to the PL group. These findings support the need for larger trials.

A retrospective comparative study of arthroscopic fixation in acute Rockwood type IV acromioclavicular joint dislocation: single versus double paired Endobutton technique.

PubMed

Xu, Jian; Liu, Haifeng; Lu, Wei; Li, Dingfu; Zhu, Weimin; Ouyang, Kan; Wu, Bing; Peng, Liangquan; Wang, Daping

2018-05-24

Rockwood type IV acromioclavicular joint (ACJ) dislocation is a trauma usually needs surgical treatment. Paired EndoButton technique (PET) is used in treating such condition. However, the effect of using different types of PET (single versus double PET) for fixation remains controversial. This study aims to evaluate and compare the efficacy of single and double PET and to provide a suitable option for the surgeons. We retrospectively reviewed the charts of patients with acute Rockwood type IV ACJ dislocation who had undergone arthroscopic fixation using single or double PET fixation between March 2009 and March 2015. Seventy-eight consecutive patients identified from chart review were picked and were divided into the single and double PET group with 39 cases in each group. The indexes of visual analog scale score (VAS) for pain, the radiographs of the affected shoulder at different time points of the follow-up, the time of return to activities and sports, the constant functional score, and the Karlsson acromioclavicular joint (ACJ) score, were assessed in a minimum of 2 years postoperation. The average coracoclavicular (CC) and acromioclavicular (AC) distances of the affected joints in the double PET group were significantly smaller than those of the single PET group 2 years postoperation (P < 0.05). The average AC and CC distances in the healthy shoulder joints were significantly smaller than those of the affected joints in the single PET group (P < 0.05); however, these values were not significantly different from those of the affected joints in the double PET group (P > 0.05). The mean VAS pain score was not significantly different, while significant difference was found for the number and times of cases return to activities and sports, constant functional score, and Karlsson ACJ score (P < 0.05) between the two groups. Therefore, the double PET group has better outcome than the single PET group. Complications including redislocation, button slippage, erosion, or AC joint instability occurred in the single PET group, while the complication in the double PET group was rare. Compared with the single PET, the double PET group achieved better outcome with less complications in arthroscopically treating acute Rockwood type IV ACJ dislocation.

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2013 CFR

2013-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2012 CFR

2012-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

40 CFR 270.18 - Specific part B information requirements for waste piles.

Code of Federal Regulations, 2014 CFR

2014-07-01

... future time; (ii) The double liner and leak (leachate) detection, collection, and removal system, if the..., where applicable; (d) A description of how each waste pile, including the double liner system, leachate...

Solar system applications of Mie theory and of radiative transfer of polarized light

NASA Technical Reports Server (NTRS)

Whitehill, L. P.

1972-01-01

A theory of the multiple scattering of polarized light is discussed using the doubling method of van de Hulst. The concept of the Stokes parameters is derived and used to develop the form of the scattering phase matrix of a single particle. The diffuse reflection and transmission matrices of a single scattering plane parallel atmosphere are expressed as a function of the phase matrix, and the symmetry properties of these matrices are examined. Four matrices are required to describe scattering and transmission. The scattering matrix that results from the addition of two identical layers is derived. Using the doubling method, the scattering and transmission matrices of layers of arbitrary optical thickness can be derived. The doubling equations are then rewritten in terms of their Fourier components. Computation time is reduced since each Fourier component doubles independently. Computation time is also reduced through the use of symmetry properties.

Biodegradable double-targeted PTX-mPEG-PLGA nanoparticles for ultrasound contrast enhanced imaging and antitumor therapy in vitro.

PubMed

Ma, Jing; Shen, Ming; Xu, Chang Song; Sun, Ying; Duan, You Rong; Du, Lian Fang

2016-11-29

A porous-structure nano-scale ultrasound contrast agent (UCA) was made of monomethoxypoly (ethylene glycol)-poly (lactic-co-glycolic acid) (mPEG-PLGA), and modified by double-targeted antibody: anti-carcinoembryonic antigen (CEA) and anti-carbohydrate antigen 19-9 (CA19-9), as a double-targeted nanoparticles (NPs). Anti-tumor drug paclitaxel (PTX) was encapsulated in the double-targeted nanoparticles (NPs). The morphor and release curve were characterized. We verified a certain anticancer effect of PTX-NPs through cytotoxicity experiments. The cell uptake result showed much more NPs may be facilitated to ingress the cells or tissues with ultrasound (US) or ultrasound targeted microbubble destruction (UTMD) transient sonoporation in vitro. Ultrasound contrast-enhanced images in vitro and in vivo were investigated. Compared with SonoVue, the NPs prolonged imaging time in rabbit kidneys and tumor of nude mice, which make it possible to further enhance anti-tumor effects by extending retention time in the tumor region. The novel double-targeted NPs with the function of ultrasound contrast enhanced imaging and anti-tumor therapy can be a promising way in clinic.

Generating cycle flow between dark and light zones with double paddlewheels to improve microalgal growth in a flat plate photo-bioreactor.

PubMed

Cheng, Jun; Xu, Junchen; Lu, Hongxiang; Ye, Qing; Liu, Jianzhong; Zhou, Junhu

2018-08-01

Double paddlewheels were proposed to generate cycle flow for increasing horizontal fluid velocity between dark and light zones in a flat plate photo-bioreactor, which strengthened the mass transfer and the mixing effect to improve microalgal growth with 15% CO 2 . Numerical fluid dynamics were used to simulate the cycle flow field with double paddlewheels. The local flow field measured with particle image velocimetry fitted well with the numerical simulation results. The horizontal fluid velocity in the photo-bioreactor was markedly increased from 5.8 × 10 -5  m/s to 0.45 m/s with the rotation of double paddlewheels, resulting in a decreased dark/light cycle period. Therefore, bubble formation time and diameter reduced by 24.4% and 27.4%, respectively. Meanwhile, solution mixing time reduced by 31.3% and mass transfer coefficient increased by 41.2%. The biomass yield of microalgae Nannochloropsis Oceanic increased by 127.1% with double paddlewheels under 15% CO 2 condition. Copyright © 2018 Elsevier Ltd. All rights reserved.

An increased estimate of the merger rate of double neutron stars from observations of a highly relativistic system.

PubMed

Burgay, M; D'Amico, N; Possenti, A; Manchester, R N; Lyne, A G; Joshi, B C; McLaughlin, M A; Kramer, M; Sarkissian, J M; Camilo, F; Kalogera, V; Kim, C; Lorimer, D R

2003-12-04

The merger of close binary systems containing two neutron stars should produce a burst of gravitational waves, as predicted by the theory of general relativity. A reliable estimate of the double-neutron-star merger rate in the Galaxy is crucial in order to predict whether current gravity wave detectors will be successful in detecting such bursts. Present estimates of this rate are rather low, because we know of only a few double-neutron-star binaries with merger times less than the age of the Universe. Here we report the discovery of a 22-ms pulsar, PSR J0737-3039, which is a member of a highly relativistic double-neutron-star binary with an orbital period of 2.4 hours. This system will merge in about 85 Myr, a time much shorter than for any other known neutron-star binary. Together with the relatively low radio luminosity of PSR J0737-3039, this timescale implies an order-of-magnitude increase in the predicted merger rate for double-neutron-star systems in our Galaxy (and in the rest of the Universe).

Double Standards and First Principles: Framing Teaching Assistant Support for Pupils with Special Educational Needs

ERIC Educational Resources Information Center

Webster, Rob; Blatchford, Peter; Bassett, Paul; Brown, Penelope; Martin, Clare; Russell, Anthony

2010-01-01

Teaching assistants (TAs) are part of a growing international trend toward paraprofessionals working in public services. There has been controversy over TAs' deployment and appropriate role when supporting the learning of pupils with special educational needs (SEN) in mainstream schools. Such debates have been transformed by findings from a large…

A Double Dose of Disadvantage: Language Experiences for Low-Income Children in Home and School

ERIC Educational Resources Information Center

Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley M.

2018-01-01

There is a virtual consensus regarding the types of language processes, interactions, and material supports that are central for young children to become proficient readers and writers (Shanahan et al., 2008). In this study, we examine these supports in both home and school contexts during children's critical transitional kindergarten year.…

[Double mulching application for Panax notoginseng growing seedlings].

PubMed

Ou, Xiao-Hong; Fang, Yan; Shi, Ya-Na; Guo, Lan-Ping; Wang, Li; Yang, Yan; Jin, Hang; Liu, Da-Hui

2014-02-01

In order to improve the irrigation for Panax notginseng growing seedlings, different mulching ways were carried out to investigate the effects of double mulching. Field experiment was applied to study soil moisture, soil temperature and bulk density of different mulching ways while the germination rate and seedlings growth also were investigated. Compared with the traditional single mulching with pine leaves or straw, double mulching using plastic film combined with pine leaves or straw could reduce 2/3 volumes of irrigation at the early seedling time Double mulching treatments didn't need to irrigate for 40 days from seeding to germination, and kept soil moisture and temperature steady at whole seedling time about 30% and 9.0-16.6 degrees C, respectively. The steady soil moisture and temperature benefited to resist late spring cold and germinate earlier while kept germination regularly, higher rate and seedlings quality. In contrast, single mulching using pine leaves or straw had poor soil moisture and temperature preserving, needed to irrigate every 12-day, meanwhile dropped the germination and booming time 14 days and 24-26 days, respectively, reduced germination rate about 11.3%-8.7%. However, single pine leaves mulching was better than straw mulching. In addition, though better effects of soil moisture and temperature preserving as well as earlier and higher rate of germination with single plastic films mulching had, some disadvantages had also been observed, such as daily soil temperature changed greatly, seedling bed soil hardened easily, more moss and weeds resulted difficulty in later management. To the purpose of saving water and labor as well as getting higher germination rate and seedlings quality, double mulching using plastic films combined pine leaves at the early time and single mulching removing plastic films at the later time is suggested to apply in the growing seedlings of P. notoginseng.

Piloting a Collaborative Web-Based System for Testing ICD-11.

PubMed

Donada, Marc; Kostanjsek, Nenad; Della Mea, Vincenzo; Celik, Can; Jakob, Robert

2017-01-01

The 11^th revision of the International Classification of Diseases (ICD-11), for the first time in ICD history, deployed web-based collaboration of experts and ICT tools. To ensure that ICD-11 is working well, it needs to be systematically field tested in different settings, across the world. This will be done by means of a number of experiments. In order to support its implementation, a web-based system (ICDfit) has been designed and developed. The present paper illustrates the current prototype of the system and its technical testing. the system has been designed according to WHO requirements, and implemented using PHP and MySQL. Then, a preliminary technical test has been designed and run in January 2016, involving 8 users. They had to carry out double coding, that is, coding case summaries with both ICD-10 and ICD-11, and answering quick questions on the coding difficulty. the 8 users coded 632 cases each, spending an average of 163 seconds per case. While we found an issue in the mechanism used to record coding times, no further issues were found. the proposed system seems to be technically adequate for supporting future ICD-11 testing.

Adverse effect on syngeneic islet transplantation by transgenic coexpression of decoy receptor 3 and heme oxygenase-1 in the islet of NOD mice.

PubMed

Huang, S-H; Lin, G-J; Chien, M-W; Chu, C-H; Yu, J-C; Chen, T-W; Hueng, D-Y; Liu, Y-L; Sytwu, H-K

2013-03-01

Decoy receptor 3 (DcR3) blocks both Fas ligand- and LIGHT-induced pancreatic β-cell damage in autoimmune diabetes. Heme oxygenase 1 (HO-1) possesses antiapoptotic, anti-inflammatory, and antioxidative effects that protect cells against various forms of attack by the immune system. Previously, we have demonstrated that transgenic islets overexpressing DcR3 or murine HO-1 (mHO-1) exhibit longer survival times than nontransgenic islets in syngeneic islet transplantation. In this study, we evaluated whether DcR3 and mHO-1 double-transgenic islets of NOD mice could provide better protective effects and achieve longer islet graft survival than DcR3 or mHO-1 single-transgenic islets after islet transplantation. We generated DcR3 and mHO-1 double-transgenic NOD mice that specifically overexpress DcR3 and HO-1 in islets. Seven hundred islets isolated from double-transgenic, single-transgenic, or nontransgenic NOD mice were syngeneically transplanted into the kidney capsules of newly diabetic female recipients. Unexpectedly, there was no significant difference in the survival time between double-transgenic or nontransgenic NOD islet grafts, and the survival times of double-transgenic NOD islet grafts were even shorter than those of DcR3 or mHO-1 single-transgenic islets. Our data indicate that transplantation of double-transgenic islets that coexpress HO-1 and DcR3 did not result in a better outcome. On the contrary, this strategy even caused an adverse effect in syngeneic islet transplantation. Copyright © 2013 Elsevier Inc. All rights reserved.

On the impact of GNSS ambiguity resolution: geometry, ionosphere, time and biases

NASA Astrophysics Data System (ADS)

Khodabandeh, A.; Teunissen, P. J. G.

2018-06-01

Integer ambiguity resolution (IAR) is the key to fast and precise GNSS positioning and navigation. Next to the positioning parameters, however, there are several other types of GNSS parameters that are of importance for a range of different applications like atmospheric sounding, instrumental calibrations or time transfer. As some of these parameters may still require pseudo-range data for their estimation, their response to IAR may differ significantly. To infer the impact of ambiguity resolution on the parameters, we show how the ambiguity-resolved double-differenced phase data propagate into the GNSS parameter solutions. For that purpose, we introduce a canonical decomposition of the GNSS network model that, through its decoupled and decorrelated nature, provides direct insight into which parameters, or functions thereof, gain from IAR and which do not. Next to this qualitative analysis, we present for the GNSS estimable parameters of geometry, ionosphere, timing and instrumental biases closed-form expressions of their IAR precision gains together with supporting numerical examples.

The impact of weight classification on safety: timing steps to adapt to external constraints

PubMed Central

Gill, S.V.

2015-01-01

Objectives: The purpose of the current study was to evaluate how weight classification influences safety by examining adults’ ability to meet a timing constraint: walking to the pace of an audio metronome. Methods: With a cross-sectional design, walking parameters were collected as 55 adults with normal (n=30) and overweight (n=25) body mass index scores walked to slow, normal, and fast audio metronome paces. Results: Between group comparisons showed that at the fast pace, those with overweight body mass index (BMI) had longer double limb support and stance times and slower cadences than the normal weight group (all ps<0.05). Examinations of participants’ ability to meet the metronome paces revealed that participants who were overweight had higher cadences at the slow and fast paces (all ps<0.05). Conclusions: Findings suggest that those with overweight BMI alter their gait to maintain biomechanical stability. Understanding how excess weight influences gait adaptation can inform interventions to improve safety for individuals with obesity. PMID:25730658

Holographic space and time: Emergent in what sense?

NASA Astrophysics Data System (ADS)

Vistarini, Tiziana

2017-08-01

This paper proposes a metaphysics for holographic duality. In addition to the AdS/CFT correspondence I also consider the dS/CFT conjecture of duality. Both involve non-perturbative string theory and both are exact dualities. But while the AdS/CFT keeps time at the margins of the story, the dS/CFT conjecture gives to time the "space" it deserves by presenting an interesting holographic model of it. My goals in this paper can be summarized in the following way. First, I argue that the formal structure and physical content of the duality do not support the standard philosophical reading of the relation in terms of grounding. Second, I put forward a philosophical scheme mainly extrapolated from the double aspect monism theory. I read holographic duality in this framework as it seems to fit the mathematical and physical structure of the duality smoothly. Inside this framework I propose a notion of spacetime emergence alternative to those ones commonly debated in the AdS/CFT physics and philosophy circles.

Temperature-dependent microindentation data of an epoxy composition in the glassy region

NASA Astrophysics Data System (ADS)

Minster, Jiří; Králík, Vlastimil

2015-02-01

The short-term instrumented microindentation technique was applied for assessing the influence of temperature in the glassy region on the time-dependent mechanical properties of an average epoxy resin mix near to its native state. Linear viscoelasticity theory with the assumption of time-independent Poisson ratio value forms the basis for processing the experimental results. The sharp standard Berkovich indenter was used to measure the local mechanical properties at temperatures 20, 24, 28, and 35 °C. The short-term viscoelastic compliance histories were defined by the Kohlrausch-Williams-Watts double exponential function. The findings suggest that depth-sensing indentation data of thermorheologically simple materials influenced by different temperatures in the glassy region can also be used, through the time-temperature superposition, to extract viscoelastic response functions accurately. This statement is supported by the comparison of the viscoelastic compliance master curve of the tested material with data derived from standard macro creep measurements under pressure on the material in a conformable state.

On the impact of GNSS ambiguity resolution: geometry, ionosphere, time and biases

NASA Astrophysics Data System (ADS)

Khodabandeh, A.; Teunissen, P. J. G.

2017-11-01

Integer ambiguity resolution (IAR) is the key to fast and precise GNSS positioning and navigation. Next to the positioning parameters, however, there are several other types of GNSS parameters that are of importance for a range of different applications like atmospheric sounding, instrumental calibrations or time transfer. As some of these parameters may still require pseudo-range data for their estimation, their response to IAR may differ significantly. To infer the impact of ambiguity resolution on the parameters, we show how the ambiguity-resolved double-differenced phase data propagate into the GNSS parameter solutions. For that purpose, we introduce a canonical decomposition of the GNSS network model that, through its decoupled and decorrelated nature, provides direct insight into which parameters, or functions thereof, gain from IAR and which do not. Next to this qualitative analysis, we present for the GNSS estimable parameters of geometry, ionosphere, timing and instrumental biases closed-form expressions of their IAR precision gains together with supporting numerical examples.

Validation of an automatic system (DoubleCage) for detecting the location of animals during preference tests.

PubMed

Tsai, P P; Nagelschmidt, N; Kirchner, J; Stelzer, H D; Hackbarth, H

2012-01-01

Preference tests have often been performed for collecting information about animals' acceptance of environmental refinement objects. In numerous published studies animals were individually tested during preference experiments, as it is difficult to observe group-housed animals with an automatic system. Thus, videotaping is still the most favoured method for observing preferences of socially-housed animals. To reduce the observation workload and to be able to carry out preference testing of socially-housed animals, an automatic recording system (DoubleCage) was developed for determining the location of group-housed animals in a preference test set-up. This system is able to distinguish the transition of individual animals between two cages and to record up to 16 animals at the same time (four animals per cage). The present study evaluated the reliability of the DoubleCage system. The data recorded by the DoubleCage program and the data obtained by human observation were compared. The measurements of the DoubleCage system and manual observation of the videotapes are comparable and significantly correlated (P < 0.0001) with good agreement. Using the DoubleCage system enables precise and reliable recording of the preferences of group-housed animals and a considerable reduction of animal observation time.

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.

Ortho-positronium observation in the Double Chooz experiment

DOE PAGES

Abe, Y.; dos Anjos, J. C.; Barriere, J. C.; ...

2014-10-01

The Double Chooz experiment measures the neutrino mixing angle θ13 by detecting reactor ν¯e via inverse beta decay. The positron-neutron space and time coincidence allows for a sizable background rejection, nonetheless liquid scintillator detectors would

Is computer aided detection (CAD) cost effective in screening mammography? A model based on the CADET II study

PubMed Central

2011-01-01

Background Single reading with computer aided detection (CAD) is an alternative to double reading for detecting cancer in screening mammograms. The aim of this study is to investigate whether the use of a single reader with CAD is more cost-effective than double reading. Methods Based on data from the CADET II study, the cost-effectiveness of single reading with CAD versus double reading was measured in terms of cost per cancer detected. Cost (Pound (£), year 2007/08) of single reading with CAD versus double reading was estimated assuming a health and social service perspective and a 7 year time horizon. As the equipment cost varies according to the unit size a separate analysis was conducted for high, average and low volume screening units. One-way sensitivity analyses were performed by varying the reading time, equipment and assessment cost, recall rate and reader qualification. Results CAD is cost increasing for all sizes of screening unit. The introduction of CAD is cost-increasing compared to double reading because the cost of CAD equipment, staff training and the higher assessment cost associated with CAD are greater than the saving in reading costs. The introduction of single reading with CAD, in place of double reading, would produce an additional cost of £227 and £253 per 1,000 women screened in high and average volume units respectively. In low volume screening units, the high cost of purchasing the equipment will results in an additional cost of £590 per 1,000 women screened. One-way sensitivity analysis showed that the factors having the greatest effect on the cost-effectiveness of CAD with single reading compared with double reading were the reading time and the reader's professional qualification (radiologist versus advanced practitioner). Conclusions Without improvements in CAD effectiveness (e.g. a decrease in the recall rate) CAD is unlikely to be a cost effective alternative to double reading for mammography screening in UK. This study provides updated estimates of CAD costs in a full-field digital system and assessment cost for women who are re-called after initial screening. However, the model is highly sensitive to various parameters e.g. reading time, reader qualification, and equipment cost. PMID:21241473

Submolecular Structure and Orientation of Oligonucleotide Duplexes Tethered to Gold Electrodes Probed by Infrared Reflection Absorption Spectroscopy: Effect of the Electrode Potentials.

PubMed

Kékedy-Nagy, László; Ferapontova, Elena E; Brand, Izabella

2017-02-23

Unique electronic and ligand recognition properties of the DNA double helix provide basis for DNA applications in biomolecular electronic and biosensor devices. However, the relation between the structure of DNA at electrified interfaces and its electronic properties is still not well understood. Here, potential-driven changes in the submolecular structure of DNA double helices composed of either adenine-thymine (dAdT) 25 or cytosine-guanine (dGdC) 20 base pairs tethered to the gold electrodes are for the first time analyzed by in situ polarization modulation infrared reflection absorption spectroscopy (PM IRRAS) performed under the electrochemical control. It is shown that the conformation of the DNA duplexes tethered to gold electrodes via the C 6 alkanethiol linker strongly depends on the nucleic acid sequence composition. The tilt of purine and pyrimidine rings of the complementary base pairs (dAdT and dGdC) depends on the potential applied to the electrode. By contrast, neither the conformation nor orientation of the ionic in character phosphate-sugar backbone is affected by the electrode potentials. At potentials more positive than the potential of zero charge (pzc), a gradual tilting of the double helix is observed. In this tilted orientation, the planes of the complementary purine and pyrimidine rings lie ideally parallel to each other. These potentials do not affect the integral stability of the DNA double helix at the charged interface. At potentials more negative than the pzc, DNA helices adopt a vertical to the gold surface orientation. Tilt of the purine and pyrimidine rings depends on the composition of the double helix. In monolayers composed of (dAdT) 25 molecules the rings of the complementary base pairs lie parallel to each other. By contrast, the tilt of purine and pyrimidine rings in (dGdC) 20 helices depends on the potential applied to the electrode. Such potential-induced mobility of the complementary base pairs can destabilize the helix structure at a submolecular level. These pioneer results on the potential-driven changes in the submolecular structure of double stranded DNA adsorbed on conductive supports contribute to further understanding of the potential-driven sequence-specific electronic properties of surface-tethered oligonucleotides.

Botulinum toxin a in the treatment of chronic tension-type headache with cervical myofascial trigger points: a randomized, double-blind, placebo-controlled pilot study.

PubMed

Harden, R Norman; Cottrill, Jerod; Gagnon, Christine M; Smitherman, Todd A; Weinland, Stephan R; Tann, Beverley; Joseph, Petra; Lee, Thomas S; Houle, Timothy T

2009-05-01

To evaluate the efficacy of botulinum toxin A (BT-A) as a prophylactic treatment for chronic tension-type headache (CTTH) with myofascial trigger points (MTPs) producing referred head pain. Although BT-A has received mixed support for the treatment of TTH, deliberate injection directly into the cervical MTPs very often found in this population has not been formally evaluated. Patients with CTTH and specific MTPs producing referred head pain were assigned randomly to receive intramuscular injections of BT-A or isotonic saline (placebo) in a double-blind design. Daily headache diaries, pill counts, trigger point pressure algometry, range of motion assessment, and responses to standardized pain and psychological questionnaires were used as outcome measures; patients returned for follow-up assessment at 2 weeks, 1 month, 2 months, and 3 months post injection. After 3 months, all patients were offered participation in an open-label extension of the study. Effect sizes were calculated to index treatment effects among the intent-to-treat population; individual time series models were computed for average pain intensity. The 23 participants reported experiencing headache on a near-daily basis (average of 27 days/month). Compared with placebo, patients in the BT-A group reported greater reductions in headache frequency during the first part of the study (P = .013), but these effects dissipated by week 12. Reductions in headache intensity over time did not differ significantly between groups (P = .80; maximum d = 0.13), although a larger proportion of BT-A patients showed evidence of statistically significant improvements in headache intensity in the time series analyses (62.5% for BT-A vs 30% for placebo). There were no differences between the groups on any of the secondary outcome measures. The evidence for BT-A in headache is mixed, and even more so in CTTH. However, the putative technique of injecting BT-A directly into the ubiquitous MTPs in CTTH is partially supported in this pilot study. Definitive trials with larger samples are needed to test this hypothesis further.

Dynamic postural stability for double-leg drop landing.

PubMed

Niu, Wenxin; Zhang, Ming; Fan, Yubo; Zhao, Qinping

2013-01-01

Dynamic postural stability has been widely studied for single-leg landing, but seldom considered for double-leg landing. This study aimed to evaluate the dynamic postural stability and the influence mechanism of muscle activities during double-leg drop landing. Eight recreationally active males and eight recreationally active females participated in this study and dropped individually from three heights (0.32 m, 0.52 m, and 0.72 m). Ground reaction force was recorded to calculate the time to stabilisation. Electromyographic activities were recorded for selected lower-extremity muscles. A multivariate analysis of variance was carried out and no significant influence was found in time to stabilisation between genders or limb laterals (P > 0.05). With increasing drop height, time to stabilisation decreased significantly in two horizontal directions and the lower-extremity muscle activities were enhanced. Vertical time to stabilisation was not significantly influenced by drop height. Dynamic postural stability improved by neuromuscular change more than that required due to the increase of drop height. Double-leg landing on level ground is a stable movement, and the body would often be injured before dynamic postural stability is impaired. It is understandable to protect tissues from mechanical injuries by the sacrifice of certain dynamic postural stability in the design of protective devices or athlete training.

Topological Weyl superconductor to diffusive thermal Hall metal crossover in the B phase of UPt3

NASA Astrophysics Data System (ADS)

Goswami, Pallab; Nevidomskyy, Andriy H.

2015-12-01

The recent phase-sensitive measurements in the superconducting B phase of UPt3 provide strong evidence for the triplet, chiral kz(kx±i ky) 2 pairing symmetries, which endow the Cooper pairs with orbital angular momentum projections Lz=±2 along the c axis. In the absence of disorder such pairing can support both line and point nodes, and both types of nodal quasiparticles exhibit nontrivial topology in the momentum space. The point nodes, located at the intersections of the closed Fermi surfaces with the c axis, act as the double monopoles and the antimonopoles of the Berry curvature, and generalize the notion of Weyl quasiparticles. Consequently, the B phase should support an anomalous thermal Hall effect, the polar Kerr effect, in addition to the protected Fermi arcs on the (1 ,0 ,0 ) and the (0 ,1 ,0 ) surfaces. The line node at the Fermi surface equator acts as a vortex loop in the momentum space and gives rise to the zero-energy, dispersionless Andreev bound states on the (0 ,0 ,1 ) surface. At the transition from the B phase to the A phase, the time-reversal symmetry is restored, and only the line node survives inside the A phase. As both line and double-Weyl point nodes possess linearly vanishing density of states, we show that weak disorder acts as a marginally relevant perturbation. Consequently, an infinitesimal amount of disorder destroys the ballistic quasiparticle pole, while giving rise to a diffusive phase with a finite density of states at the zero energy. The resulting diffusive phase exhibits T -linear specific heat, and an anomalous thermal Hall effect. We predict that the low-temperature thermodynamic and transport properties display a crossover between a ballistic thermal Hall semimetal and a diffusive thermal Hall metal. By contrast, the diffusive phase obtained from a time-reversal-invariant pairing exhibits only the T -linear specific heat without any anomalous thermal Hall effect.

Spatiotemporal and kinematic changes in gait while carrying an energy harvesting assault pack system.

PubMed

Talarico, Maria K; Haynes, Courtney A; Douglas, Julianne S; Collazo, Jose

2018-06-06

Soldiers are fielded with a variety of equipment including battery powered electronic devices. An energy harvesting assault pack (EHAP) was developed to provide a power source to recharge batteries and reduce the quantity and load of extra batteries carried into the field. Little is known about the biomechanical implications of carrying a suspended-load energy harvesting system compared to the military standard assault pack (AP). Therefore, the goal of this study was to determine the impact of pack type and load magnitude on spatiotemporal and kinematic parameters while walking at 1.34 m/s on an instrumented treadmill at decline, level, and incline grades. There was greater forward trunk lean while carrying the EHAP and the heavy load (decline: p < 0.001; level: p = 0.009; incline: p = 0.003). As load increased from light to heavy, double support stance time was longer (decline: p = 0.012; level: p < 0.001; incline: p < 0.001), strides were shorter (incline: p = 0.013), and knee flexion angle at heel strike was greater (decline: p = 0.033; level: p = 0.035; incline: p = 0.005). When carrying the EHAP, strides (decline: p = 0.007) and double support stance time (incline: p = 0.006) was longer, the knee was more flexed at heel strike (level: p = 0.014; incline: p < 0.001) and there was a smaller change in knee flexion during weight acceptance (decline: p = 0.0013; level: p = 0.007; incline: p = 0.0014). Carrying the EHAP elicits changes to gait biomechanics compared to carrying the standard AP. Understanding how load-suspension systems influence loaded gait biomechanics are warranted before transitioning these systems into military or recreational environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

High School and Community College Astronomy Research Seminar

NASA Astrophysics Data System (ADS)

Genet, Russell M.; Boyce, Pat; Buchheim, Robert; Collins, Dwight; Freed, Rachel; Harshaw, Richard; Johnson, Jolyon; Kenney, John; Wallen, Vera

2016-06-01

For the past decade, Cuesta College has held an Astronomy Research Seminar. Teams of high school and community college students, with guidance from instructors and advanced amateur astronomers, have made astronomical observations, reduced their data, and submitted their research results to appropriate journals. A variety of projects, using modest-aperture telescopes equipped with low-cost instruments, are within reach of motivated students. These include double star astrometry, variable star photometry, and exoplanet transit timing. Advanced scientific knowledge and mastery of sophisticated experimental skills are not required when the students are immersed within a supportive community of practice. The seminar features self-paced, online learning units, an online textbook (the Small Telescope Astronomical Research Handbook), and a supportive website sponsored by the Institute for Student Astronomical Research (www.In4StAR.org). There are no prerequisites for the seminar. This encourages everyone—including underrepresented minorities and persons with disabilities—to participate. Each participant contributes as their time, talents, and experience dictates, thus replicating the modern, professional research team. Our spring 2015 seminar was the largest yet. Volunteer assistant instructors provided local in-person leadership, while the entire seminar met online for PowerPoint presentations on proposed projects and final research results. Some 37 students from eight schools finished the seminar as coauthors of 19 papers published in the January 2016 volume of the Journal of Double Star Observations. Robotic telescopes devoted to student research are coming online at both Concordia University and the Boyce Astronomical Robotic Observatory, as is a central online sever that will provide students with uniform, cost-free reduction and analysis software. The seminar has motivated many of its graduates to pursue careers in science, engineering, and medicine, often with scholarships. We are planning on expanding the seminar to other high schools and community colleges within California and across the nation.

Lifting of Spin Blockade by Charged Impurities in Si-MOS Double Quantum Dot Devices

NASA Astrophysics Data System (ADS)

King, Cameron; Schoenfield, Joshua; Calderón, M. J.; Koiller, Belita; Saraiva, André; Hu, Xuedong; Jiang, Hong-Wen; Friesen, Mark; Coppersmith, S. N.

Fabricating quantum dots in silicon metal-oxide-semiconductor (MOS) for quantum information processing applications is attractive because of the long spin coherence times in silicon and the potential for leveraging the massive investments that have been made for scaling of the technology for classical electronics. One obstacle that has impeded the development of electrically gated MOS singlet-triplet qubits is the lack of observed spin blockade, where the tunneling of a second electron into a dot is fast when the two-electron state is a singlet and slow when the two-electron state is a triplet, even in samples with large singlet-triplet energy splittings. We show that this is a commonly exhibited problem in MOS double quantum dots, and present evidence that the cause is stray positive charges in the oxide layer inducing accidental dots near the device's active region that allow spin blockade lifting. This work was supported by ARO (W911NF-12-1-0607), NSF (IIA-1132804), the Department of Defense under Contract No. H98230-15-C 0453, ARO (W911NF-14-1-0346), NSF (OISE-1132804), ONR (N00014-15-1-0029), and ARO (W911NF-12-R-0012).

Structure of Room Temperature Ionic Liquids on Charged Graphene: An integrated experimental and computational study

NASA Astrophysics Data System (ADS)

Uysal, Ahmet; Zhou, Hua; Lee, Sang Soo; Fenter, Paul; Feng, Guang; Li, Song; Cummings, Peter; Fulvio, Pasquale; Dai, Sheng; McDonough, Jake; Gogotsi, Yury

2014-03-01

Electrical double layer capacitors (EDLCs) with room temperature ionic liquid (RTIL) electrolytes and carbon electrodes are promising candidates for energy storage devices with high power density and long cycle life. We studied the potential and time dependent changes in the electric double layer (EDL) structure of an imidazolium-based room temperature ionic liquid (RTIL) electrolyte at an epitaxial graphene (EG) surface. We used in situ x-ray reflectivity (XR) to determine the EDL structure at static potentials, during cyclic voltammetry (CV) and potential step measurements. The static potential structures were also investigated with fully atomistic molecular dynamics (MD) simulations. Combined XR and MD results show that the EDL structure has alternating anion/cation layers within the first nanometer of the interface. The dynamical response of the EDL to potential steps has a slow component (>10 s) and the RTIL structure shows hysteresis during CV scans. We propose a conceptual model that connects nanoscale interfacial structure to the macroscopic measurements. This material is based upon work supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science (SC), Office of Basic Energy

A randomized double-blinded controlled trial of hCG as luteal phase support in natural cycle frozen embryo transfer.

PubMed

Lee, Vivian Chi Yan; Li, Raymond Hang Wun; Yeung, William Shu Biu; Pak Chung, H O; Ng, Ernest Hung Yu

2017-05-01

Does the use of hCG as luteal phase support in natural cycle frozen embryo transfer (FET) increase the ongoing pregnancy rate? The use of hCG in natural cycle FET did not improve the ongoing pregnancy rate. The use of luteal phase support in stimulated cycles has been associated with higher live-birth rates and the results are similar when using hCG or progesterone. This is a randomized double-blinded controlled trial of 450 women recruited between August 2013 and October 2015. Women with regular cycles undergoing natural cycle FET were recruited. Serial serum hormonal concentrations were used to time natural ovulation and at least Day 2 cleavage embryos were replaced. Patients were randomized into either: (i) the treatment group, receiving 1500 IU hCG on the day of FET and 6 days after FET, or (ii) the control group, receiving normal saline on these 2 days. The ongoing pregnancy rate [60/225 (26.7%) in the treatment group vs 70/225 (31.3%) in the control group, odds ratio 1.242 (95% CI 0.825-1.869)], implantation rate and miscarriage rate were comparable between the two groups. In the treatment group, there were significantly more cycles with top quality embryos transferred and a significantly higher serum oestradiol level, but a comparable serum progesterone level, 6 days after FET. However, no significant differences were observed in serum oestradiol and progesterone levels 6 days after FET between the pregnant and non-pregnant women. In the multivariate logistic regression, the number of embryos transferred was the only significant factor predictive of the ongoing pregnancy rate after natural cycle FET. This study only included FET with cleavage stage embryos and only hCG, not vaginal progesterone, was used as luteal phase support. The findings in this study do not support the use of hCG for luteal phase support in natural cycle FET. No external funding was used and there were no competing interests. clinicaltrial.gov identifier: NCT01931384. 23/8/2013. 30/8/2013. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Embryo deaths in reproduction and embryo research: a reply to Murphy's double effect argument.

PubMed

Devolder, Katrien

2013-08-01

The majority of embryos created in natural reproduction die spontaneously within a few weeks of conception. Some have argued that, therefore, if one believes the embryo is a person (in the normative sense) one should find 'natural' reproduction morally problematic. An extension of this argument holds that, if one accepts embryo deaths in natural reproduction, consistency requires that one also accepts embryo deaths that occur in (i) assisted reproduction via in vitro fertilisation (IVF) and (ii) embryo research. In a recent paper in this journal, Timothy Murphy criticises both the initial argument and its extension. Murphy argues that double-effect reasoning can justify embryo deaths both in natural reproduction and IVF, but not in embryo research. Thus, according to Murphy, one can, without being inconsistent, (1) believe the embryo is a person and accept natural reproduction and IVF, and (2) accept natural reproduction and IVF, while rejecting embryo research on the ground that it involves embryo deaths. I show that Murphy's argument is problematic because double effect cannot justify embryo deaths in standard IVF practices. The problem is that the proportionality criterion of double effect is not met by such practices. Thus, Murphy's argument fails to support (1) and (2). An implication of his argument failing to support (2) is that it does not defeat the position I have defended in the past-that if one accepts standard IVF practices one should also accept embryo research, including research with embryos created solely for that purpose.

A Comparative Evaluation of the Effect of Double Casting Technique Using Functionally Generated Path and Conventional Single Casting with Respect to Functional Articulation, Patient Satisfaction and Chair Side Time, in Single Unit Molar Teeth: An In Vivo Study.

PubMed

Memon, Sarfaraz

2014-12-01

A stable centric occlusal position that shows no evidence of occlusal disease should not be altered. Confirmative restorative dentistry deals with making restorations that are in harmony with existing jaw relations. Conventional techniques for construction have been unsuccessful in producing a prosthesis that can be inserted without minor intraoral occlusal adjustment. This study was conducted to evaluate the benefits of the double casting technique with FGP over the conventional casting technique. Ten patients with root canal treated maxillary molar were selected for the fabrication of metal crown. Two techniques, one involving the conventional fabrication and other using functionally generated path with double casting were used to fabricate the prosthesis. A comparison based on various parameters which was done between the two techniques. The change in the height of castings for the double casting group was less compared to the conventional group and was highly statistically significant (P < 0.001). The time taken for occlusal correction was significantly lower in double casting group than the conventional group (P < 0.001). The patient satisfaction (before occlusal correction) indicated better satisfaction for double casting group compared to conventional (P < 0.01). The functionally generated path with double casting technique resulted in castings which had better dimensional accuracy, less occlusal correction and better patient satisfaction compared to the conventional castings.

Prereplicative complexes assembled in vitro support origin-dependent and independent DNA replication

PubMed Central

On, Kin Fan; Beuron, Fabienne; Frith, David; Snijders, Ambrosius P; Morris, Edward P; Diffley, John F X

2014-01-01

Eukaryotic DNA replication initiates from multiple replication origins. To ensure each origin fires just once per cell cycle, initiation is divided into two biochemically discrete steps: the Mcm2-7 helicase is first loaded into prereplicative complexes (pre-RCs) as an inactive double hexamer by the origin recognition complex (ORC), Cdt1 and Cdc6; the helicase is then activated by a set of “firing factors.” Here, we show that plasmids containing pre-RCs assembled with purified proteins support complete and semi-conservative replication in extracts from budding yeast cells overexpressing firing factors. Replication requires cyclin-dependent kinase (CDK) and Dbf4-dependent kinase (DDK). DDK phosphorylation of Mcm2-7 does not by itself promote separation of the double hexamer, but is required for the recruitment of firing factors and replisome components in the extract. Plasmid replication does not require a functional replication origin; however, in the presence of competitor DNA and limiting ORC concentrations, replication becomes origin-dependent in this system. These experiments indicate that Mcm2-7 double hexamers can be precursors of replication and provide insight into the nature of eukaryotic DNA replication origins. PMID:24566989

Mapping chemical/structural order in double perovskite Sr2-xGdxMnTiO6 by atomic resolution electron microscopy

NASA Astrophysics Data System (ADS)

Alvarez, Inmaculada; Biskup, Neven; Lopez, Maria; Garcia-Hernandez, Mar; Veiga, Luisa; Varela, Maria; UCM Collaboration; ORNL Collaboration; CSIC Collaboration

2013-03-01

We report on visualizing the chemical and structural order of double perovskite Sr2-xGdxMnTiO6. The antisite disorder of Mn and Ti is detected even at atomic scale at all x, resulting in Mn-rich and Ti-rich regions. For x ?0.75, the majority of manganese ions are in Mn3+ state and are centered in Jahn-Teller distorted MnO6octahedra. The Fourier transformation of atomic resolution images along the [110] zone axis reveals a superstructure that corresponds to the tilting of oxygen octahedra and that doubles the unit cell along [001]c. This superstructure is spatially inhomogeneous and coincides with the regions where B-site ion (Mn/Ti) is displaced along the [110] direction. We discuss these findings in the frame of possible local ferroelectricity and in the light of strong electroresistance observed in Sr1.25Gd0.75MnTiO6. Research at ORNL supported by the U.S. DOE-BES, Materials Sciences and Engineering Division, and also by ORNL's ShaRE User Program (sponsored by DOE-BES). Research at UCM supported by the ERC Starting Investigator Award and MAT2010-20117.

Gait strategy changes with acceleration to accommodate the biomechanical constraint on push-off propulsion.

PubMed

Oh, Keonyoung; Baek, Juhyun; Park, Sukyung

2012-11-15

To maintain steady and level walking, push-off propulsion during the double support phase compensates for the energy loss through heel strike collisions in an energetically optimal manner. However, a large portion of daily gait activities also contains transient gait responses, such as acceleration or deceleration, during which the observed dominance of the push-off work or the energy optimality may not hold. In this study, we examined whether the push-off propulsion during the double support phase served as a major energy source for gait acceleration, and we also studied the energetic optimality of accelerated gait using a simple bipedal walking model. Seven healthy young subjects participated in the over-ground walking experiments. The subjects walked at four different constant gait speeds ranging from a self-selected speed to a maximum gait speed, and then they accelerated their gait from zero to the maximum gait speed using a self-selected acceleration ratio. We measured the ground reaction force (GRF) of three consecutive steps and the corresponding leg configuration using force platforms and an optical marker system, respectively, and we compared the mechanical work performed by the GRF during each single and double support phase. In contrast to the model prediction of an increase in the push-off propulsion that is proportional to the acceleration and minimizes the mechanical energy cost, the push-off propulsion was slightly increased, and a significant increase in the mechanical work during the single support phase was observed. The results suggest that gait acceleration occurs while accommodating a feasible push-off propulsion constraint. Copyright © 2012 Elsevier Ltd. All rights reserved.

Self-consistent electrostatic simulations of reforming double layers in the downward current region of the aurora

NASA Astrophysics Data System (ADS)

Gunell, H.; Andersson, L.; De Keyser, J.; Mann, I.

2015-10-01

The plasma on a magnetic field line in the downward current region of the aurora is simulated using a Vlasov model. It is found that an electric field parallel to the magnetic fields is supported by a double layer moving toward higher altitude. The double layer accelerates electrons upward, and these electrons give rise to plasma waves and electron phase-space holes through beam-plasma interaction. The double layer is disrupted when reaching altitudes of 1-2 Earth radii where the Langmuir condition no longer can be satisfied due to the diminishing density of electrons coming up from the ionosphere. During the disruption the potential drop is in part carried by the electron holes. The disruption creates favourable conditions for double layer formation near the ionosphere and double layers form anew in that region. The process repeats itself with a period of approximately 1 min. This period is determined by how far the double layer can reach before being disrupted: a higher disruption altitude corresponds to a longer repetition period. The disruption altitude is, in turn, found to increase with ionospheric density and to decrease with total voltage. The current displays oscillations around a mean value. The period of the oscillations is the same as the recurrence period of the double layer formations. The oscillation amplitude increases with increasing voltage, whereas the mean value of the current is independent of voltage in the 100 to 800 V range covered by our simulations. Instead, the mean value of the current is determined by the electron density at the ionospheric boundary.

Nucleic acid nanomaterials: Silver-wired DNA

NASA Astrophysics Data System (ADS)

Auffinger, Pascal; Ennifar, Eric

2017-10-01

DNA double helical structures are supramolecular assemblies that are typically held together by classical Watson-Crick pairing. Now, nucleotide chelation of silver ions supports an extended silver-DNA hybrid duplex featuring an uninterrupted silver array.

Nuclear Plant Siting Study. Volume 2

DTIC Science & Technology

1976-06-01

210 feet apart with sliding type supports every 35 feet. See Figure 3-6 for support details. A double wrapping of mineral wool insulation with...3,000 Mhr 11.80 35,400 (M 3,500 12", XS, .375 Wall - Conduit 20" (M 1,000 LF 105 105,000 (L 3,700 Mhr 11.80 43,700 (M 4,300 Insulation Mineral Wool 3

Partially unzipped carbon nanotubes as a superior catalyst support for PEM fuel cells.

PubMed

Long, Donghui; Li, Wei; Qiao, Wenming; Miyawaki, Jin; Yoon, Seong-Ho; Mochida, Isao; Ling, Licheng

2011-09-07

Partially unzipped carbon nanotubes prepared by strong oxidation and thermal expansion of carbon nanotubes were explored as an advanced catalyst support for PEM fuel cells. The unique hybrid structure of 1D nanotube and 2D double-side graphene resulted in an outstanding electrocatalytic performance. This journal is © The Royal Society of Chemistry 2011

Existence domain of electrostatic solitary waves in the lunar wake

NASA Astrophysics Data System (ADS)

Rubia, R.; Singh, S. V.; Lakhina, G. S.

2018-03-01

Electrostatic solitary waves (ESWs) and double layers are explored in a four-component plasma consisting of hot protons, hot heavier ions (He++), electron beam, and suprathermal electrons having κ-distribution using the Sagdeev pseudopotential method. Three modes exist: slow and fast ion-acoustic modes and electron-acoustic mode. The occurrence of ESWs and their existence domain as a function of various plasma parameters, such as the number densities of ions and electron beam, the spectral index, κ, the electron beam velocity, the temperatures of ions, and electron beam, are analyzed. It is observed that both the slow and fast ion-acoustic modes support both positive and negative potential solitons as well as their coexistence. Further, they support a "forbidden gap," the region in which the soliton ceases to propagate. In addition, slow ion-acoustic solitons support the existence of both positive and negative potential double layers. The electron-acoustic mode is only found to support negative potential solitons for parameters relevant to the lunar wake plasma. Fast Fourier transform of a soliton electric field produces a broadband frequency spectrum. It is suggested that all three soliton types taken together can provide a good explanation for the observed electrostatic waves in the lunar wake.

Electrochemical Sensing and Imaging Based on Ion Transfer at Liquid/Liquid Interfaces

PubMed Central

Amemiya, Shigeru; Kim, Jiyeon; Izadyar, Anahita; Kabagambe, Benjamin; Shen, Mei; Ishimatsu, Ryoichi

2013-01-01

Here we review the recent applications of ion transfer (IT) at the interface between two immiscible electrolyte solutions (ITIES) for electrochemical sensing and imaging. In particular, we focus on the development and recent applications of the nanopipet-supported ITIES and double-polymer-modified electrode, which enable the dynamic electrochemical measurements of IT at nanoscopic and macroscopic ITIES, respectively. High-quality IT voltammograms are obtainable using either technique to quantitatively assess the kinetics and dynamic mechanism of IT at the ITIES. Nanopipet-supported ITIES serves as an amperometric tip for scanning electrochemical microscopy to allow for unprecedentedly high-resolution electrochemical imaging. Voltammetric ion sensing at double-polymer-modified electrodes offers high sensitivity and unique multiple-ion selectivity. The promising future applications of these dynamic approaches for bioanalysis and electrochemical imaging are also discussed. PMID:24363454

Double-ended metal halide arc discharge lamp with electrically isolated containment shroud

NASA Technical Reports Server (NTRS)

Muzeroll, Martin M. (Inventor)

1994-01-01

A double-ended arc discharge lamp includes a sealed, light-transmissive outer jacket, a light-transmissive shroud mounted within the outer jacket and directly supported by the outer jacket, and an arc discharge tube mounted within the shroud. The arc tube is typically a metal halide arc discharge tube. In a preferred embodiment, the shroud includes an outwardly flared portion at each end. The outwardly flared portions space the shroud from the outer jacket and support the shroud within the outer jacket. The outwardly flared portions of the shroud can be affixed to the outer jacket by fusing. The outer jacket can be provided with inwardly extending dimples for locating the shroud with respect to the outer jacket. In another embodiment, the outer jacket includes reduced diameter portions near each end which are attached to the shroud.

Controllability of a multichannel system

NASA Astrophysics Data System (ADS)

Ivanov, Sergei A.; Wang, Jun Min

2018-02-01

We consider the system consisting of K coupled acoustic channels with the different sound velocities cj. Channels are interacting at any point via the pressure and its time derivatives. Using the moment approach and the theory of exponential families with vector coefficients we establish two controllability results: the system is exactly controllable if (i) the control uj in the jth channel acts longer than the double travel time of a wave from the start to the end of the j-th channel; (ii) all controls uj act more than or equal to the maximal double travel time.

Pharmacokinetics of Lopinavir in HIV-Infected Adults Receiving Rifampin with Adjusted Doses of Lopinavir-Ritonavir Tablets▿

PubMed Central

Decloedt, Eric H.; McIlleron, Helen; Smith, Peter; Merry, Concepta; Orrell, Catherine; Maartens, Gary

2011-01-01

Rifampin coadministration dramatically reduces plasma lopinavir (LPV) concentrations. In healthy volunteers, doubling the dose of a lopinavir-ritonavir (LPV/r) capsule formulation overcame this interaction, but a subsequent study of double doses of the tablet formulation was stopped early owing to hepatotoxicity. However, healthy-volunteer study findings may not apply to HIV-infected adults. We evaluated the steady-state pharmacokinetics of LPV in HIV-infected adults virologically suppressed on an LPV/r regimen who were given rifampin, and the dose of the LPV/r tablet formulation was gradually increased. The steady-state pharmacokinetics of LPV/r were evaluated at baseline, a week after commencing rifampin, a week after the LPV/r dose was increased 1.5 times, and a week after the LPV/r dose was doubled. Twenty-one participants were enrolled. The median [interquartile range (IQR)] predose LPV concentrations (C0) were 8.1 (6.2 to 9.8) mg/liter at baseline, 1.7 (0.3 to 3.0) mg/liter after 7 days of rifampin, 5.9 (2.1 to 9.9) mg/liter with 1.5 times the dose of LPV/r, and 10.8 (7.0 to 13.1) mg/liter with double-dose LPV/r. There were no significant differences in the LPV area under the plasma concentration-time curve from 0 to 12 h (AUC0-12), C0, C12, maximum concentration of drug in serum (Cmax), or half-life (t1/2) between the baseline and double-dose LPV/r time points. Treatment was generally well tolerated, with two participants developing asymptomatic grade 3/4 transaminitis. Doubling the dose of the tablet formulation of LPV/r overcomes induction by rifampin. Less hepatotoxicity occurred in our cohort of HIV-infected participants than was reported in healthy-volunteer studies. PMID:21537021

Effect of observation on lower limb prosthesis gait biomechanics: Preliminary results.

PubMed

Malchow, Connor; Fiedler, Goeran

2016-12-01

The Hawthorne effect, a subcategory of reactivity, causes human behavior to change when under observation. Such an effect may apply to gait variation of persons with prosthetics or orthotics devices. This study investigated whether the presence of observers directly affects the gait pattern of users of lower limb prostheses. Within-subject intervention study. Primary outcome measures were gait parameters of initial double support time and upper body lateral tilt angle, which were collected with a mobile sensor attached to the subjects' back. To make subjects feel unwatched, a certain amount of deception was necessary, and two different conditions were created and statistically compared against each other: one in which the subjects were initially unaware of the attention of observers and another one in which the same subjects were aware of a group of observers. Data from two subjects using trans-femoral prosthesis are reported. Findings included a change in step initial double support percentage by up to 14.2% (p = 0.019). Considerable changes were also noted in secondary outcome measures including speed, stride length, and stride symmetry. A reactivity effect of observation exists in prosthetics gait analysis. More comprehensive studies may be motivated by these preliminary findings. Results of this study suggest that users of lower limb prostheses walk differently when their gait is being assessed (e.g. in the prosthetist's office) than in situations without observers. This may in part explain the clinical experience that modifications of prosthetic fit or alignment provide only short-term betterment. © The International Society for Prosthetics and Orthotics 2015.

Double deprivation: a phenomenological study into the experience of being a carer during a mental health crisis.

PubMed

Albert, Rikke; Simpson, Alan

2015-12-01

To explore carers' experience of caring during a mental health crisis. Community mental health care including crisis care relies increasingly on carers. The relationship between carers and professionals is at times fraught due to issues of what constitutes a crisis, confidentiality and a perception of lack of empathy. The caring experience can lead carers to feel isolated and neglected. A qualitative study with a phenomenological approach. Eight carers participated and were interviewed individually using a semi-structured approach. Analysis used the Interpretive Phenomenological Analysis method including transcribing of interviews, initial noting, searching for connections and patterns across the transcripts and cases. The themes were checked with the participants for their views on the emerging themes. The data were collected from November 2011-May 2012. Carers experienced 'double deprivation' by not receiving support from professionals and protecting their social network from the trauma of the crisis. The caring in crisis invoked complex feelings of guilt and loyalty which made discussing aggression difficult. Caring was described as a terrifying experience not just because of the aggression but also because of the perception of abandonment by professionals. The experience was an overwhelmingly negative one with a wish for acknowledgement of the crisis and support from mental health services. For most of the participants the caring during crisis was traumatic which left the carer feeling isolated and unsupported. The study should be used to help educate professionals on the complexities of caring during a crisis. © 2015 John Wiley & Sons Ltd.

Modeling electrical double-layer effects for microfluidic impedance spectroscopy from 100 kHz to 110 GHz.

PubMed

Little, Charles A E; Orloff, Nathan D; Hanemann, Isaac E; Long, Christian J; Bright, Victor M; Booth, James C

2017-07-25

Broadband microfluidic-based impedance spectroscopy can be used to characterize complex fluids, with applications in medical diagnostics and in chemical and pharmacological manufacturing. Many relevant fluids are ionic; during impedance measurements ions migrate to the electrodes, forming an electrical double-layer. Effects from the electrical double-layer dominate over, and reduce sensitivity to, the intrinsic impedance of the fluid below a characteristic frequency. Here we use calibrated measurements of saline solution in microfluidic coplanar waveguide devices at frequencies between 100 kHz and 110 GHz to directly measure the double-layer admittance for solutions of varying ionic conductivity. We successfully model the double-layer admittance using a combination of a Cole-Cole response with a constant phase element contribution. Our analysis yields a double-layer relaxation time that decreases linearly with solution conductivity, and allows for double-layer effects to be separated from the intrinsic fluid response and quantified for a wide range of conducting fluids.

Microfluidic preparation and self diffusion PFG-NMR analysis of monodisperse water-in-oil-in-water double emulsions.

PubMed

Hughes, Eric; Maan, Abid Aslam; Acquistapace, Simone; Burbidge, Adam; Johns, Michael L; Gunes, Deniz Z; Clausen, Pascal; Syrbe, Axel; Hugo, Julien; Schroen, Karin; Miralles, Vincent; Atkins, Tim; Gray, Richard; Homewood, Philip; Zick, Klaus

2013-01-01

Monodisperse water-in-oil-in-water (WOW) double emulsions have been prepared using microfluidic glass devices designed and built primarily from off the shelf components. The systems were easy to assemble and use. They were capable of producing double emulsions with an outer droplet size from 100 to 40 μm. Depending on how the devices were operated, double emulsions containing either single or multiple water droplets could be produced. Pulsed-field gradient self-diffusion NMR experiments have been performed on the monodisperse water-in-oil-in-water double emulsions to obtain information on the inner water droplet diameter and the distribution of the water in the different phases of the double emulsion. This has been achieved by applying regularization methods to the self-diffusion data. Using these methods the stability of the double emulsions to osmotic pressure imbalance has been followed by observing the change in the size of the inner water droplets over time. Copyright © 2012 Elsevier Inc. All rights reserved.

Single-row versus double-row rotator cuff repair: techniques and outcomes.

PubMed

Dines, Joshua S; Bedi, Asheesh; ElAttrache, Neal S; Dines, David M

2010-02-01

Double-row rotator cuff repair techniques incorporate a medial and lateral row of suture anchors in the repair configuration. Biomechanical studies of double-row repair have shown increased load to failure, improved contact areas and pressures, and decreased gap formation at the healing enthesis, findings that have provided impetus for clinical studies comparing single-row with double-row repair. Clinical studies, however, have not yet demonstrated a substantial improvement over single-row repair with regard to either the degree of structural healing or functional outcomes. Although double-row repair may provide an improved mechanical environment for the healing enthesis, several confounding variables have complicated attempts to establish a definitive relationship with improved rates of healing. Appropriately powered rigorous level I studies that directly compare single-row with double-row techniques in matched tear patterns are necessary to further address these questions. These studies are needed to justify the potentially increased implant costs and surgical times associated with double-row rotator cuff repair.

Double Charge Exchange Reactions and Double Beta Decay

NASA Astrophysics Data System (ADS)

Auerbach, N.

2018-05-01

The subject of this presentation is at the forefront of nuclear physics, namely double beta decay. In particular one is most interested in the neutrinoless process of double beta decay, when the decay proceeds without the emission of two neutrinos. The observation of such decay would mean that the lepton conservation symmetry is violated and that the neutrinos are of Majorana type, meaning that they are their own anti-particles. The life time of this process has two unknowns, the mass of the neutrino and the nuclear matrix element. Determining the nuclear matrix element and knowing the cross-section well will set limits on the neutrino mass. There is a concentrated effort among the nuclear physics community to calculate this matrix element. Usually these matrix elements are a very small part of the total strength of the transition operators involved in the process. There is no simple way to “calibrate” the nuclear double beta decay matrix element. The double beta decay is a double charge exchange process, therefore it is proposed that double charge exchange reactions using ion projectiles on nuclei that are candidates for double beta decay, will provide additional necessary information about the nuclear matrix elements.

Mechanical response of biopolymer double networks

NASA Astrophysics Data System (ADS)

Carroll, Joshua; Das, Moumita

We investigate a double network model of articular cartilage (AC) and characterize its equilibrium mechanical response. AC has very few cells and the extracellular matrix mainly determines its mechanical response. This matrix can be thought of as a double polymer network made of collagen and aggrecan. The collagen fibers are stiff and resist tension and compression forces, while aggrecans are flexible and control swelling and hydration. We construct a microscopic model made of two interconnected disordered polymer networks, with fiber elasticity chosen to qualitatively mimic the experimental system. We study the collective mechanical response of this double network as a function of the concentration and stiffness of the individual components as well as the strength of the connection between them using rigidity percolation theory. Our results may provide a better understanding of mechanisms underlying the mechanical resilience of AC, and more broadly may also lead to new perspectives on the mechanical response of multicomponent soft materials. This work was partially supported by a Cottrell College Science Award.

Double hull grounding experiments

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

Rodd, J.L.; Sikora, J.P.

1995-12-31

In the last few years the public and governments of many nations have become increasingly aware of the need for improving oil tanker safety. The requirements for double hull tankers are an attempt to address this need through legislation. Even though a number of investigations on the mechanics of collisions have been done in the past, until recently very little research supported the development of structural improvements to reduce oil tanker damage during grounding and stranding accidents. An aggressive evaluation of double hull tanker crashworthiness in stranding and grounding accidents is underway at CD/NSWC (formerly the David Taylor Research Center).more » The ability to predict damage from grounding accidents accurately is not currently available. The objective of this paper is to present qualitatively the structural failure mechanisms associated with stranding and grounding events for candidate double hull tanker structures and to present some simple methods for comparing damage scenarios. A comparison of the structural performance of key features in several very different designs will provide useful information toward this understanding.« less

[Verification of the double dissociation model of shyness using the implicit association test].

PubMed

Fujii, Tsutomu; Aikawa, Atsushi

2013-12-01

The "double dissociation model" of shyness proposed by Asendorpf, Banse, and Mtücke (2002) was demonstrated in Japan by Aikawa and Fujii (2011). However, the generalizability of the double dissociation model of shyness was uncertain. The present study examined whether the results reported in Aikawa and Fujii (2011) would be replicated. In Study 1, college students (n = 91) completed explicit self-ratings of shyness and other personality scales. In Study 2, forty-eight participants completed IAT (Implicit Association Test) for shyness, and their friends (n = 141) rated those participants on various personality scales. The results revealed that only the explicit self-concept ratings predicted other-rated low praise-seeking behavior, sociable behavior and high rejection-avoidance behavior (controlled shy behavior). Only the implicit self-concept measured by the shyness IAT predicted other-rated high interpersonal tension (spontaneous shy behavior). The results of this study are similar to the findings of the previous research, which supports generalizability of the double dissociation model of shyness.

Double shell planar experiments on OMEGA

NASA Astrophysics Data System (ADS)

Dodd, E. S.; Merritt, E. C.; Palaniyappan, S.; Montgomery, D. S.; Daughton, W. S.; Schmidt, D. W.; Cardenas, T.; Wilson, D. C.; Loomis, E. N.; Batha, S. H.; Ping, Y.; Smalyuk, V. A.; Amendt, P. A.

2017-10-01

The double shell project is aimed at fielding neutron-producing capsules at the National Ignition Facility (NIF), in which an outer low-Z ablator collides with an inner high-Z shell to compress the fuel. However, understanding these targets experimentally can be challenging when compared with conventional single shell targets. Halfraum-driven planar targets at OMEGA are being used to study physics issues important to double shell implosions outside of a convergent geometry. Both VISAR and radiography through a tube have advantages over imaging through the hohlraum and double-shell capsule at NIF. A number physics issues are being studied with this platform that include 1-d and higher dimensional effects such as defect-driven hydrodynamic instabilities from engineering features. Additionally, the use of novel materials with controlled density gradients require study in easily diagnosed 1-d systems. This work ultimately feeds back into the NIF capsule platform through manufacturing tolerances set using data from OMEGA. Supported under the US DOE by the LANS, LLC under contract DE-AC52-06NA25396. LA-UR-17-25386.

A Pilot Study of Gait Function in Farmworkers in Eastern North Carolina.

PubMed

Nguyen, Ha T; Kritchevsky, Stephen B; Foxworth, Judy L; Quandt, Sara A; Summers, Phillip; Walker, Francis O; Arcury, Thomas A

2015-01-01

Farmworkers endure many job-related hazards, including fall-related work injuries. Gait analysis may be useful in identifying potential fallers. The goal of this pilot study was to explore differences in gait between farmworkers and non-farmworkers. The sample included 16 farmworkers and 24 non-farmworkers. Gait variables were collected using the portable GAITRite system, a 16-foot computerized walkway. Generalized linear regression models were used to examine group differences. All models were adjusted for two established confounders, age and body mass index. There were no significant differences in stride length, step length, double support time, and base of support; but farmworkers had greater irregularity of stride length (P = .01) and step length (P = .08). Farmworkers performed significantly worse on gait velocity (P = .003) and cadence (P < .001) relative to non-farmworkers. We found differences in gait function between farmworkers and non-farmworkers. These findings suggest that measuring gait with a portable walkway system is feasible and informative in farmworkers and may possibly be of use in assessing fall risk.

Algal culture studies related to a closed ecological life support system

NASA Technical Reports Server (NTRS)

Radmer, R.; Behrens, P.; Fernandez, E.; Ollinger, O.; Howell, C.

1984-01-01

Studies on the steady-state long-term (4 month) culture of Scenedesmus obliquus algae, maintained in an annular air-lift column operated as a turbidostat, were carried out to evaluate the life-supporting possibilities of this system. Chlorophyll production and cell number as functions of the dry weight were linear at constant illumination. Productivity (measured as the product of dry weight, mg/ml, and the growth rate, ml/hr) vs. dry weight rose linearly until the cell density reached a level at which light became limiting (89 percent absorption of the photosynthetically active radiation). In the initial, linear portion of the curve, the productivity was limited by cell growth at the given light intensity. The maximum dilution rate of the system corresponded to the doubling time of 13.4 hr, about half the maximum rate, with a productivity of 80 percent of the maximum theoretical productivity. The high light utilization efficiencies were contributed by the low (10 percent of full sunlight) incident intensities.

Measurements of spin life time of an antimony-bound electron in silicon

NASA Astrophysics Data System (ADS)

Lu, T. M.; Bishop, N. C.; Tracy, L. A.; Blume-Kohout, R.; Pluym, T.; Wendt, J. R.; Dominguez, J.; Lilly, M. P.; Carroll, M. S.

2013-03-01

We report our measurements of spin life time of an antimony-bound electron in silicon. The device is a double-top-gated silicon quantum dot with antimony atoms implanted near the quantum dot region. A donor charge transition is identified by observing a charge offset in the transport characteristics of the quantum dot. The tunnel rates on/off the donor are first characterized and a three-level pulse sequence is then used to measure the spin populations at different load-and-wait times in the presence of a fixed magnetic field. The spin life time is extracted from the exponential time dependence of the spin populations. A spin life time of 1.27 seconds is observed at B = 3.25 T. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Clinical Outcome of Double Crown-Retained Mandibular Removable Dentures Supported by a Combination of Residual Teeth and Strategic Implants.

PubMed

Rinke, Sven; Ziebolz, Dirk; Ratka-Krüger, Petra; Frisch, Eberhard

2015-07-01

There is a lack of data regarding the clinical outcome of removable partial dentures (RPDs) supported by a combination of residual natural teeth and implants placed in strategic positions. The aim of the present case series was to conduct a retrospective investigation of the clinical outcome of mandibular tooth-implant-retained partial dentures (TIRPD) rigidly retained via telescopic double crowns. Between 1999 and 2010, 18 patients with reduced residual dentition (1 to 3 natural abutment teeth) and in need of an RPD received 1 to 3 implants in strategic positions for support of the removable prostheses. All TIRPDs were rigidly retained by telescopic crowns according to the Marburg Double Crown (MDC) technique; all prostheses were placed in a private practice. Tooth/implant survival and success rates, prosthetic maintenance requirements, and peri-implant parameters were analyzed retrospectively using patient records and clinical examinations during the final recall appointments. Only patients attending at least annual supportive post-implant hygiene therapy visits (SIT) were included. After a mean functional period of 5.84 ± 3 years (range: 3.01-12.21), 14 patients with 14 dentures supported by 24 implants and 27 teeth (mean number of abutments: 3.6) were available for assessment. Four teeth (survival rate: 85.19%) and no implants (survival rate: 100%) were lost. Peri-implantitis was observed around one implant (4.17%). All 14 dentures were functional (survival rate: 100%) and required only limited maintenance (i.e., screw loosening, acrylic resin fracture repairs, relining) amounting to 0.086 treatments per patient per year (T/P/Y). Within the limitations of this case series, it can be concluded that TIRPDs retained via MDCs might represent a viable treatment option in mandibles with few remaining abutment teeth. Further long-term clinical evaluations with a greater sample size are needed for a more detailed evaluation of this treatment concept. © 2014 by the American College of Prosthodontists.

Double-Entry Bookkeeping.

ERIC Educational Resources Information Center

Snyder, Herbert

1999-01-01

Explains the principles and mechanics of double-entry bookkeeping as a part of the accounting cycle to produce a functioning set of accounting records. Suggests that libraries need to have accurate and timely information about their spending to gain financial control and protect against fraud and abuse. (LRW)

Fast valve based on double-layer eddy-current repulsion for disruption mitigation in Experimental Advanced Superconducting Tokamak.

PubMed

Zhuang, H D; Zhang, X D

2015-05-01

A fast valve based on the double-layer eddy-current repulsion mechanism has been developed on Experimental Advanced Superconducting Tokamak (EAST). In addition to a double-layer eddy-current coil, a preload system was added to improve the security of the valve, whereby the valve opens more quickly and the open-valve time becomes shorter, making it much safer than before. In this contribution, testing platforms, open-valve characteristics, and throughput of the fast valve are discussed. Tests revealed that by choosing appropriate parameters the valve opened within 0.15 ms, and open-valve times were no longer than 2 ms. By adjusting working parameter values, the maximum number of particles injected during this open-valve time was estimated at 7 × 10(22). The fast valve will become a useful tool to further explore disruption mitigation experiments on EAST in 2015.

Analytic double product integrals for all-frequency relighting.

PubMed

Wang, Rui; Pan, Minghao; Chen, Weifeng; Ren, Zhong; Zhou, Kun; Hua, Wei; Bao, Hujun

2013-07-01

This paper presents a new technique for real-time relighting of static scenes with all-frequency shadows from complex lighting and highly specular reflections from spatially varying BRDFs. The key idea is to depict the boundaries of visible regions using piecewise linear functions, and convert the shading computation into double product integrals—the integral of the product of lighting and BRDF on visible regions. By representing lighting and BRDF with spherical Gaussians and approximating their product using Legendre polynomials locally in visible regions, we show that such double product integrals can be evaluated in an analytic form. Given the precomputed visibility, our technique computes the visibility boundaries on the fly at each shading point, and performs the analytic integral to evaluate the shading color. The result is a real-time all-frequency relighting technique for static scenes with dynamic, spatially varying BRDFs, which can generate more accurate shadows than the state-of-the-art real-time PRT methods.

Central versus peripheral cannulation of extracorporeal membrane oxygenation support during double lung transplant for pulmonary hypertension.

PubMed

Glorion, Matthieu; Mercier, Olaf; Mitilian, Delphine; De Lemos, Alexandra; Lamrani, Lilia; Feuillet, Séverine; Pradere, Pauline; Lepavec, Jérôme; Lehouerou, Daniel; Stephan, François; Savale, Laurent; Fabre, Dominique; Mussot, Sacha; Fadel, Elie

2018-03-08

Extracorporeal membrane oxygenation (ECMO) has become the standard of cardiopulmonary support during a sequential double lung transplant for pulmonary hypertension. Whether central or peripheral cannulation is the best strategy for these patients remains unknown. Our goal was to determine which is the best strategy by comparing 2 populations of patients. We performed a single-centre retrospective study based on an institutional prospective lung transplant database. Between January 2011 and November 2016, 103 patients underwent double lung transplant for pulmonary hypertension. We compared 54 patients who had central ECMO (cECMO group) to 49 patients who had peripheral ECMO (pECMO group). The pECMO group had significantly more bridged patients who received emergency transplants (31% vs 6%, P = 0.001). The incidence of Grade 3 primary graft dysfunction requiring ECMO (14% vs 11%, P = not significant) and of in-hospital mortality (11% vs 14%, P = not significant) was similar between the groups. Groin infections (16% vs 4%, P = 0.031), deep vein thrombosis (27% vs 11%, P = 0.044) and lower limb ischaemia (12% vs 2%, P = 0.031) occurred significantly more often in the pECMO group. The number of chest reopenings for bleeding or infection was similar between the groups. The 3-month, 1-year and 5-year survival rates did not differ between the groups (P = 0.94). Central or peripheral ECMO produced similar results during double lung transplant for pulmonary hypertension in terms of in-hospital deaths and long-term survival rates. Central ECMO provided satisfactory results without major bleeding provided the patient was weaned from ECMO at the end of the procedure. Despite the rate of groin and lower limb complications, peripheral cannulation remained the preferred solution to bridge the patient to transplant or for postoperative support.

Stress and family quality of life in parents of children with autism spectrum disorder: parent gender and the double ABCX model.

PubMed

McStay, Rebecca L; Trembath, David; Dissanayake, Cheryl

2014-12-01

Past research has supported the utility of the Double ABCX model of family adaptation for parents raising a child with autism spectrum disorder (ASD). What remains unclear is the impact of family-related variables on outcomes in both mothers and fathers within the same family. We explored the potential predictors of maternal and paternal stress and family quality of life in an Australian sample of 196 parents of children with ASD aged 3-16 years. Using a cross-sectional design, parents completed questionnaires assessing factors within the Double ABCX model attributed to family adaptation. Findings provide further evidence of the negative impact of child externalising behaviours and highlight the importance of family sense of coherence on positive parental outcomes.

Monte Carlo calculations of PET coincidence timing: single and double-ended readout

PubMed Central

Derenzo, Stephen E; Choong, Woon-Seng; Moses, William W

2016-01-01

We present Monte Carlo computational methods for estimating the coincidence resolving time (CRT) of scintillator detector pairs in positron emission tomography (PET) and present results for Lu2SiO5 : Ce (LSO), LaBr3 : Ce, and a hypothetical ultra-fast scintillator with a 1 ns decay time. The calculations were applied to both single-ended and double-ended photodetector readout with constant-fraction triggering. They explicitly include (1) the intrinsic scintillator properties (luminosity, rise time, decay time, and index of refraction), (2) the exponentially distributed depths of interaction, (3) the optical photon transport efficiency, delay, and time dispersion, (4) the photodetector properties (fill factor, quantum efficiency, transit time jitter, and single electron response), and (5) the determination of the constant fraction trigger level that minimizes the CRT. The calculations for single-ended readout include the delayed photons from the opposite reflective surface. The calculations for double-ended readout include (1) the simple average of the two photodetector trigger times, (2) more accurate estimators of the annihilation photon entrance time using the pulse height ratio to estimate the depth of interaction and correct for annihilation photon, optical photon, and trigger delays, and (3) the statistical lower bound for interactions at the center of the crystal. For time-of-flight (TOF) PET we combine stopping power and TOF information in a figure of merit equal to the sensitivity gain relative to whole-body non-TOF PET using LSO. For LSO crystals 3 mm × 3 mm × 30 mm, a decay time of 37 ns, a total photoelectron count of 4000, and a photodetector with 0.2 ns full-width at half-maximum (fwhm) timing jitter, single-ended readout has a CRT of 0.16 ns fwhm and double-ended readout has a CRT of 0.111 ns fwhm. For LaBr3 : Ce crystals 3 mm × 3 mm × 30 mm, a rise time of 0.2 ns, a decay time of 18 ns, and a total of 7600 photoelectrons the CRT numbers are 0.14 ns and 0.072 ns fwhm, respectively. For a hypothetical ultra-fast scintillator 3 mm × 3 mm × 30 mm, a decay time of 1 ns, and a total of 4000 photoelectrons, the CRT numbers are 0.070 and 0.020 ns fwhm, respectively. Over a range of examples, values for double-ended readout are about 10% larger than the statistical lower bound. PMID:26350162

Sensitivity and Discovery Potential of CUORE to Neutrinoless Double-Beta Decay

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

Alessandria, F; Ardito, R; Artusa, DR

We present a study of the sensitivity and discovery potential of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity for various background scenarios are presented, and an extension of the sensitivity formulation to the discovery potential case is also discussed. Assuming a background rate of 10 -2 cts/(keV kg y), we find that, after 5 years of live time, CUORE has a 1 sigma sensitivity to the neutrinoless double-beta decay half-life of Tmore » $$0v\\atop{1/2}$$(1θ) = 1.6 \\times 10 26 y and thus a potential to probe the effective Majorana neutrino mass down to 40-100 meV; the sensitivity at 1.64 sigma, which corresponds to 90% C.L., will be T$$0v\\atop{1/2}$$(1.64θ) = 9.5 \\times 10 25 y. This range is compared with the claim of observation of neutrinoless double-beta decay in 76Ge and the preferred range of the neutrino mass parameter space from oscillation results.« less

Characterization of the Electric Double Layer Formation Dynamics of a Metal/Ionic Liquid/Metal Structure.

PubMed

Schmidt, Elliot; Shi, Sha; Ruden, P Paul; Frisbie, C Daniel

2016-06-15

Although ionic liquids (ILs) have been used extensively in recent years as a high-capacitance "dielectric" in electric double layer transistors, the dynamics of the double layer formation have remained relatively unexplored. Better understanding of the dynamics and relaxation processes involved in electric double layer formation will guide device optimization, particularly with regard to switching speed. In this paper, we explore the dynamical characteristics of an IL in a metal/ionic liquid/metal (M/IL/M) capacitor. In particular, we examine a Au/IL/Au structure where the IL is 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate. The experiments consist of frequency-dependent impedance measurements and time-dependent current vs voltage measurements for applied linear voltage ramps and abrupt voltage steps. The parameters of an equivalent circuit model are determined by fits to the impedance vs frequency data and subsequently verified by calculating the current vs voltage characteristics for the applied potential profiles. The data analysis indicates that the dynamics of the structure are characterized by a wide distribution of relaxation times spanning the range of less than microseconds to longer than seconds. Possible causes for these time scales are discussed.

Neutral evolution of drug resistant colorectal cancer cell populations is independent of their KRAS status

PubMed Central

Blagoev, Krastan B.; Wilkerson, Julia; Burotto, Mauricio; Kim, Chul; Espinal-Domínguez, Edward; García-Alfonso, Pilar; Alimchandani, Meghna; Miettinen, Markku; Blanco-Codesido, Montserrat

2017-01-01

Emergence of tumor resistance to an anti-cancer therapy directed against a putative target raises several questions including: (1) do mutations in the target/pathway confer resistance? (2) Are these mutations pre-existing? (3) What is the relative fitness of cells with/without the mutation? We addressed these questions in patients with metastatic colorectal cancer (mCRC). We conducted an exhaustive review of published data to establish a median doubling time for CRCs and stained a cohort of CRCs to document mitotic indices. We analyzed published data and our own data to calculate rates of growth (g) and regression (d, decay) of tumors in patients with CRC correlating these results with the detection of circulating MT-KRAS DNA. Additionally we estimated mathematically the caloric burden of such tumors using data on mitotic and apoptotic indices. We conclude outgrowth of cells harboring intrinsic or acquired MT-KRAS cannot explain resistance to anti-EGFR (epidermal growth factor receptor) antibodies. Rates of tumor growth with panitumumab are unaffected by presence/absence of MT-KRAS. While MT-KRAS cells may be resistant to anti-EGFR antibodies, WT-KRAS cells also rapidly bypass this blockade suggesting inherent resistance mechanisms are responsible and a neutral evolution model is most appropriate. Using the above clinical data on tumor doubling times and mitotic and apoptotic indices we estimated the caloric intake required to support tumor growth and suggest it may explain in part cancer-associated cachexia. PMID:28981524

BounceBack capsules for reduction of DOMS after eccentric exercise: a randomized, double-blind, placebo-controlled, crossover pilot study.

PubMed

Udani, Jay K; Singh, Betsy B; Singh, Vijay J; Sandoval, Elizabeth

2009-06-05

Delayed onset muscle soreness (DOMS) is muscle pain and discomfort experienced approximately one to three days after exercise. DOMS is thought to be a result of microscopic muscle fiber tears that occur more commonly after eccentric exercise rather than concentric exercise. This study sought to test the efficacy of a proprietary dietary supplement, BounceBack, to alleviate the severity of DOMS after standardized eccentric exercise. The study was a randomized, double-blind, placebo-controlled, crossover study. Ten healthy community-dwelling untrained subjects, ranging in age from 18-45 years, were enrolled. Mean differences within and between groups were assessed inferentially at each data collection time-point using t-tests for all outcome measures. In this controlled pilot study, intake of BounceBack capsules for 30 days resulted in a significant reduction in standardized measures of pain and tenderness post-eccentric exercise compared to the placebo group. There were trends towards reductions in plasma indicators of inflammation (high sensitivity C-reactive protein) and muscle damage (creatine phosphokinase and myoglobin). BounceBack capsules were able to significantly reduce standardized measures of pain and tenderness at several post-eccentric exercise time points in comparison to placebo. The differences in the serological markers of DOMS, while not statistically significant, appear to support the clinical findings. The product appears to have a good safety profile and further study with a larger sample size is warranted based on the current results.

BounceBack™ capsules for reduction of DOMS after eccentric exercise: a randomized, double-blind, placebo-controlled, crossover pilot study

PubMed Central

Udani, Jay K; Singh, Betsy B; Singh, Vijay J; Sandoval, Elizabeth

2009-01-01

Background Delayed onset muscle soreness (DOMS) is muscle pain and discomfort experienced approximately one to three days after exercise. DOMS is thought to be a result of microscopic muscle fiber tears that occur more commonly after eccentric exercise rather than concentric exercise. This study sought to test the efficacy of a proprietary dietary supplement, BounceBack™, to alleviate the severity of DOMS after standardized eccentric exercise. Methods The study was a randomized, double-blind, placebo-controlled, crossover study. Ten healthy community-dwelling untrained subjects, ranging in age from 18–45 years, were enrolled. Mean differences within and between groups were assessed inferentially at each data collection time-point using t-tests for all outcome measures. Results In this controlled pilot study, intake of BounceBack™ capsules for 30 days resulted in a significant reduction in standardized measures of pain and tenderness post-eccentric exercise compared to the placebo group. There were trends towards reductions in plasma indicators of inflammation (high sensitivity C-reactive protein) and muscle damage (creatine phosphokinase and myoglobin). Conclusion BounceBack™ capsules were able to significantly reduce standardized measures of pain and tenderness at several post-eccentric exercise time points in comparison to placebo. The differences in the serological markers of DOMS, while not statistically significant, appear to support the clinical findings. The product appears to have a good safety profile and further study with a larger sample size is warranted based on the current results. PMID:19500355

Neutral evolution of drug resistant colorectal cancer cell populations is independent of their KRAS status.

PubMed

Blagoev, Krastan B; Wilkerson, Julia; Burotto, Mauricio; Kim, Chul; Espinal-Domínguez, Edward; García-Alfonso, Pilar; Alimchandani, Meghna; Miettinen, Markku; Blanco-Codesido, Montserrat; Fojo, Tito

2017-01-01

Emergence of tumor resistance to an anti-cancer therapy directed against a putative target raises several questions including: (1) do mutations in the target/pathway confer resistance? (2) Are these mutations pre-existing? (3) What is the relative fitness of cells with/without the mutation? We addressed these questions in patients with metastatic colorectal cancer (mCRC). We conducted an exhaustive review of published data to establish a median doubling time for CRCs and stained a cohort of CRCs to document mitotic indices. We analyzed published data and our own data to calculate rates of growth (g) and regression (d, decay) of tumors in patients with CRC correlating these results with the detection of circulating MT-KRAS DNA. Additionally we estimated mathematically the caloric burden of such tumors using data on mitotic and apoptotic indices. We conclude outgrowth of cells harboring intrinsic or acquired MT-KRAS cannot explain resistance to anti-EGFR (epidermal growth factor receptor) antibodies. Rates of tumor growth with panitumumab are unaffected by presence/absence of MT-KRAS. While MT-KRAS cells may be resistant to anti-EGFR antibodies, WT-KRAS cells also rapidly bypass this blockade suggesting inherent resistance mechanisms are responsible and a neutral evolution model is most appropriate. Using the above clinical data on tumor doubling times and mitotic and apoptotic indices we estimated the caloric intake required to support tumor growth and suggest it may explain in part cancer-associated cachexia.

Body stability and muscle and motor cortex activity during walking with wide stance

PubMed Central

Farrell, Brad J.; Bulgakova, Margarita A.; Beloozerova, Irina N.; Sirota, Mikhail G.

2014-01-01

Biomechanical and neural mechanisms of balance control during walking are still poorly understood. In this study, we examined the body dynamic stability, activity of limb muscles, and activity of motor cortex neurons [primarily pyramidal tract neurons (PTNs)] in the cat during unconstrained walking and walking with a wide base of support (wide-stance walking). By recording three-dimensional full-body kinematics we found for the first time that during unconstrained walking the cat is dynamically unstable in the forward direction during stride phases when only two diagonal limbs support the body. In contrast to standing, an increased lateral between-paw distance during walking dramatically decreased the cat's body dynamic stability in double-support phases and prompted the cat to spend more time in three-legged support phases. Muscles contributing to abduction-adduction actions had higher activity during stance, while flexor muscles had higher activity during swing of wide-stance walking. The overwhelming majority of neurons in layer V of the motor cortex, 82% and 83% in the forelimb and hindlimb representation areas, respectively, were active differently during wide-stance walking compared with unconstrained condition, most often by having a different depth of stride-related frequency modulation along with a different mean discharge rate and/or preferred activity phase. Upon transition from unconstrained to wide-stance walking, proximal limb-related neuronal groups subtly but statistically significantly shifted their activity toward the swing phase, the stride phase where most of body instability occurs during this task. The data suggest that the motor cortex participates in maintenance of body dynamic stability during locomotion. PMID:24790167

Detecting the Length of Double-stranded DNA with Solid State Nanopores

NASA Astrophysics Data System (ADS)

Li, Jiali; Gershow, Marc; Stein, Derek; Qun, Cai; Brandin, Eric; Wang, Hui; Huang, Albert; Branton, Dan; Golovchenko, Jene

2003-03-01

We report on the use of nanometer scale diameter, solid-state nanopores as single molecule detectors of double stranded DNA molecules. These solid-state nanopores are fabricated in thin membranes of silicon nitride, by ion beam sculpting 1. They produce discrete electronic signals: current blockages, when an electrically biased nanopore is exposed to DNA molecules in aqueous salt solutions. We demonstrate examples of such electronic signals for 3k base pairs (bp) and 10k bp double stranded DNA molecules, which suggest that these molecules are individually translocating through the nanopore during the detection process. The translocating time for the 10k bp double stranded DNA is about 3 times longer than the 3k bp, demonstrating that a solid-state nanopore device can be used to detect the lengths of double stranded DNA molecules. Similarities and differences with signals obtained from single stranded DNA in a biological nanopores are discussed 2. 1. Li, J., Stein, D., McMullan, C., Branton, D. Aziz, M. J. and Golovchenko, J. Ion Beam Sculpting at nanometer length scales. Nature 412, 166-169 (2001). 2. Meller, A., L. Nivon, E. Brandin, Golovchenko, J. & Branton, D. Proc. Natl. Acad. Sci. USA 97, 1079-1084 (2000).

Extended MHD modeling of nonlinear instabilities in fusion and space plasmas

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

Germaschewski, Kai

A number of different sub-projects where pursued within this DOE early career project. The primary focus was on using fully nonlinear, curvilinear, extended MHD simulations of instabilities with applications to fusion and space plasmas. In particular, we performed comprehensive studies of the dynamics of the double tearing mode in different regimes and confi gurations, using Cartesian and cyclindrical geometry and investigating both linear and non-linear dynamics. In addition to traditional extended MHD involving Hall term and electron pressure gradient, we also employed a new multi-fluid moment model, which shows great promise to incorporate kinetic effects, in particular off-diagonal elements ofmore » the pressure tensor, in a fluid model, which is naturally computationally much cheaper than fully kinetic particle or Vlasov simulations. We used our Vlasov code for detailed studies of how weak collisions effect plasma echos. In addition, we have played an important supporting role working with the PPPL theory group around Will Fox and Amitava Bhattacharjee on providing simulation support for HED plasma experiments performed at high-powered laser facilities like OMEGA-EP in Rochester, NY. This project has support a great number of computational advances in our fluid and kinetic plasma models, and has been crucial to winning multiple INCITE computer time awards that supported our computational modeling.« less

Insight in schizophrenia - a double-edged sword?

PubMed

Vrbova, Kristyna; Prasko, Jan; Ociskova, Marie; Latalova, Klara; Holubova, Michaela; Grambal, Ales; Slepecky, Milos

2017-12-01

Lack of insight is defined as a loss of ability to distinguish that one's unusual and unreal experiences should be the symptoms of the psychiatric disorder requiring treatment. Lack of insight may be considered as a core symptom of schizophrenia. The concept of insight has been regarded for a long time as necessary for treatment, which improves adherence and makes a better prognosis. Increased insight in schizophrenia has been associated not only with benefits, but also bring trouble in the form of self-stigma, low self-esteem, reduced patient's hope, diminished quality of life, and increased suicidality. Therefore, insight should be managed with sensitive monitoring of the risk factors, and be gradual, carefully supported by the encouragement of hope and confidence to managing everyday life.

Temperature dependence of negative bias under illumination stress and recovery in amorphous indium gallium zinc oxide thin film transistors

NASA Astrophysics Data System (ADS)

Hossain Chowdhury, Md Delwar; Migliorato, Piero; Jang, Jin

2013-04-01

We have investigated the temperature dependence of negative bias under illumination stress and recovery. The transfer characteristics exhibits a non-rigid shift towards negative gate voltages. For both stress and recovery, the voltage shift in deep depletion is twice that in accumulation. The results support the mechanism we previously proposed, which is creation and annealing of a double donor, likely to be an oxygen vacancy. The time dependence of stress and recovery can be fitted to stretched exponentials. Both processes are thermally activated with activation energies 1.06 eV and 1.25 eV for stress and recovery, respectively. A potential energy diagram is proposed to explain the results.

Software for Photometric and Astrometric Reduction of Video Meteors

NASA Astrophysics Data System (ADS)

Atreya, Prakash; Christou, Apostolos

2007-12-01

SPARVM is a Software for Photometric and Astrometric Reduction of Video Meteors being developed at Armagh Observatory. It is written in Interactive Data Language (IDL) and is designed to run primarily under Linux platform. The basic features of the software will be derivation of light curves, estimation of angular velocity and radiant position for single station data. For double station data, calculation of 3D coordinates of meteors, velocity, brightness, and estimation of meteoroid's orbit including uncertainties. Currently, the software supports extraction of time and date from video frames, estimation of position of cameras (Azimuth, Altitude), finding stellar sources in video frames and transformation of coordinates from video, frames to Horizontal coordinate system (Azimuth, Altitude), and Equatorial coordinate system (RA, Dec).

Cost-Effectiveness between Double and Single Fecal Immunochemical Test(s) in a Mass Colorectal Cancer Screening.

PubMed

Cai, Shan-Rong; Zhu, Hong-Hong; Huang, Yan-Qin; Li, Qi-Long; Ma, Xin-Yuan; Zhang, Su-Zhan; Zheng, Shu

2016-01-01

This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.

Bootstrap-after-bootstrap model averaging for reducing model uncertainty in model selection for air pollution mortality studies.

PubMed

Roberts, Steven; Martin, Michael A

2010-01-01

Concerns have been raised about findings of associations between particulate matter (PM) air pollution and mortality that have been based on a single "best" model arising from a model selection procedure, because such a strategy may ignore model uncertainty inherently involved in searching through a set of candidate models to find the best model. Model averaging has been proposed as a method of allowing for model uncertainty in this context. To propose an extension (double BOOT) to a previously described bootstrap model-averaging procedure (BOOT) for use in time series studies of the association between PM and mortality. We compared double BOOT and BOOT with Bayesian model averaging (BMA) and a standard method of model selection [standard Akaike's information criterion (AIC)]. Actual time series data from the United States are used to conduct a simulation study to compare and contrast the performance of double BOOT, BOOT, BMA, and standard AIC. Double BOOT produced estimates of the effect of PM on mortality that have had smaller root mean squared error than did those produced by BOOT, BMA, and standard AIC. This performance boost resulted from estimates produced by double BOOT having smaller variance than those produced by BOOT and BMA. Double BOOT is a viable alternative to BOOT and BMA for producing estimates of the mortality effect of PM.

A NON-PRE DOUBLE-PEAKED BURST FROM 4U 1636-536: EVIDENCE FOR BURNING FRONT PROPAGATION

NASA Technical Reports Server (NTRS)

Bhattacharyya, Sudip; Strohmayer, Tod E.

2005-01-01

We analyse Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of a double-peaked burst from the low mass X-ray binary (LMXB) 4U 1636-536 that shows no evidence for photospheric radius expansion (PRE). We find that the X-ray emitting area on the star increases with time as the burst progresses, even though the photosphere does not expand. We argue that this is a strong indication of thermonuclear flame spreading on the stellar surface during such bursts. We propose a model for such double-peaked bursts, based on thermonuclear flame spreading, that can qualitatively explain their essential features, as well as the rarity of these bursts.

Communication: Time-dependent optimized coupled-cluster method for multielectron dynamics

NASA Astrophysics Data System (ADS)

Sato, Takeshi; Pathak, Himadri; Orimo, Yuki; Ishikawa, Kenichi L.

2018-02-01

Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled-cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived the equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method of intense-laser driven correlated electron dynamics in Ar atom is reported.

Communication: Time-dependent optimized coupled-cluster method for multielectron dynamics.

PubMed

Sato, Takeshi; Pathak, Himadri; Orimo, Yuki; Ishikawa, Kenichi L

2018-02-07

Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled-cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived the equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method of intense-laser driven correlated electron dynamics in Ar atom is reported.

The motion control of a statically stable biped robot on an uneven floor.

PubMed

Shih, C L; Chiou, C J

1998-01-01

This work studies the motion control of a statically stable biped robot having seven degrees of freedom. Statically stable walking of the biped robot is realized by maintaining the center-of-gravity inside the convex region of the supporting foot and/or feet during both single-support and double-support phases. The main points of this work are framing the stability in an easy and correct way, the design of a bipedal statically stable walker, and walking on sloping surfaces and stairs.

In Vitro Antibacterial Activity of AZD0914, a New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-Positive, Fastidious Gram-Negative, and Atypical Bacteria

PubMed Central

Bradford, Patricia A.; Otterson, Linda G.; Basarab, Gregory S.; Kutschke, Amy C.; Giacobbe, Robert A.; Patey, Sara A.; Alm, Richard A.; Johnstone, Michele R.; Potter, Marie E.; Miller, Paul F.; Mueller, John P.

2014-01-01

AZD0914 is a new spiropyrimidinetrione bacterial DNA gyrase/topoisomerase inhibitor with potent in vitro antibacterial activity against key Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus pyogenes, and Streptococcus agalactiae), fastidious Gram-negative (Haemophilus influenzae and Neisseria gonorrhoeae), atypical (Legionella pneumophila), and anaerobic (Clostridium difficile) bacterial species, including isolates with known resistance to fluoroquinolones. AZD0914 works via inhibition of DNA biosynthesis and accumulation of double-strand cleavages; this mechanism of inhibition differs from those of other marketed antibacterial compounds. AZD0914 stabilizes and arrests the cleaved covalent complex of gyrase with double-strand broken DNA under permissive conditions and thus blocks religation of the double-strand cleaved DNA to form fused circular DNA. Whereas this mechanism is similar to that seen with fluoroquinolones, it is mechanistically distinct. AZD0914 exhibited low frequencies of spontaneous resistance in S. aureus, and if mutants were obtained, the mutations mapped to gyrB. Additionally, no cross-resistance was observed for AZD0914 against recent bacterial clinical isolates demonstrating resistance to fluoroquinolones or other drug classes, including macrolides, β-lactams, glycopeptides, and oxazolidinones. AZD0914 was bactericidal in both minimum bactericidal concentration and in vitro time-kill studies. In in vitro checkerboard/synergy testing with 17 comparator antibacterials, only additivity/indifference was observed. The potent in vitro antibacterial activity (including activity against fluoroquinolone-resistant isolates), low frequency of resistance, lack of cross-resistance, and bactericidal activity of AZD0914 support its continued development. PMID:25385112

Revisiting the Fully Automated Double-Ring Infiltrometer Using Open-Source Electronics

EPA Science Inventory

The double-ring infiltrometer (DRI) is commonly used for measuring soil hydraulic conductivity. However, constant-head DRI tests typically involve the use of Mariotte tubes, which can be problematic to set-up, and time-consuming to maintain and monitor during infiltration tests....

Self-controlled learning benefits: exploring contributions of self-efficacy and intrinsic motivation via path analysis.

PubMed

Ste-Marie, Diane M; Carter, Michael J; Law, Barbi; Vertes, Kelly; Smith, Victoria

2016-09-01

Research has shown learning advantages for self-controlled practice contexts relative to yoked (i.e., experimenter-imposed) contexts; yet, explanations for this phenomenon remain relatively untested. We examined, via path analysis, whether self-efficacy and intrinsic motivation are important constructs for explaining self-controlled learning benefits. The path model was created using theory-based and empirically supported relationships to examine causal links between these psychological constructs and physical performance. We hypothesised that self-efficacy and intrinsic motivation would have greater predictive power for learning under self-controlled compared to yoked conditions. Participants learned double-mini trampoline progressions, and measures of physical performance, self-efficacy and intrinsic motivation were collected over two practice days and a delayed retention day. The self-controlled group (M = 2.04, SD = .98) completed significantly more skill progressions in retention than their yoked counterparts (M = 1.3, SD = .65). The path model displayed adequate fit, and similar significant path coefficients were found for both groups wherein each variable was predominantly predicted by its preceding time point (e.g., self-efficacy time 1 predicts self-efficacy time 2). Interestingly, the model was not moderated by group; thus, failing to support the hypothesis that self-efficacy and intrinsic motivation have greater predictive power for learning under self-controlled relative to yoked conditions.

Randomized phase 2 study of GMI-1070 in SCD: reduction in time to resolution of vaso-occlusive events and decreased opioid use

PubMed Central

Wun, Ted; McCavit, Timothy L.; De Castro, Laura M.; Krishnamurti, Lakshmanan; Lanzkron, Sophie; Hsu, Lewis L.; Smith, Wally R.; Rhee, Seungshin; Magnani, John L.; Thackray, Helen

2015-01-01

Treatment of vaso-occlusive crises (VOC) or events in sickle cell disease (SCD) remains limited to symptom relief with opioids. Animal models support the effectiveness of the pan-selectin inhibitor GMI-1070 in reducing selectin-mediated cell adhesion and abrogating VOC. We studied GMI-1070 in a prospective multicenter, randomized, placebo-controlled, double-blind, phase 2 study of 76 SCD patients with VOC. Study drug (GMI-1070 or placebo) was given every 12 hours for up to 15 doses. Other treatment was per institutional standard of care. All subjects reached the composite primary end point of resolution of VOC. Although time to reach the composite primary end point was not statistically different between the groups, clinically meaningful reductions in mean and median times to VOC resolution of 41 and 63 hours (28% and 48%, P = .19 for both) were observed in the active treatment group vs the placebo group. As a secondary end point, GMI-1070 appeared safe in acute vaso-occlusion, and adverse events were not different in the two arms. Also in secondary analyses, mean cumulative IV opioid analgesic use was reduced by 83% with GMI-1070 vs placebo (P = .010). These results support a phase 3 study of GMI-1070 (now rivipansel) for SCD VOC. This trial was registered at www.clinicaltrials.gov as #NCT01119833. PMID:25733584

Predictability of CFSv2 in the tropical Indo-Pacific region, at daily and subseasonal time scales

NASA Astrophysics Data System (ADS)

Krishnamurthy, V.

2018-06-01

The predictability of a coupled climate model is evaluated at daily and intraseasonal time scales in the tropical Indo-Pacific region during boreal summer and winter. This study has assessed the daily retrospective forecasts of the Climate Forecast System version 2 from the National Centers of Environmental Prediction for the period 1982-2010. The growth of errors in the forecasts of daily precipitation, monsoon intraseasonal oscillation (MISO) and the Madden-Julian oscillation (MJO) is studied. The seasonal cycle of the daily climatology of precipitation is reasonably well predicted except for the underestimation during the peak of summer. The anomalies follow the typical pattern of error growth in nonlinear systems and show no difference between summer and winter. The initial errors in all the cases are found to be in the nonlinear phase of the error growth. The doubling time of small errors is estimated by applying Lorenz error formula. For summer and winter, the doubling time of the forecast errors is in the range of 4-7 and 5-14 days while the doubling time of the predictability errors is 6-8 and 8-14 days, respectively. The doubling time in MISO during the summer and MJO during the winter is in the range of 12-14 days, indicating higher predictability and providing optimism for long-range prediction. There is no significant difference in the growth of forecasts errors originating from different phases of MISO and MJO, although the prediction of the active phase seems to be slightly better.

Pre-coding method and apparatus for multiple source or time-shifted single source data and corresponding inverse post-decoding method and apparatus

NASA Technical Reports Server (NTRS)

Yeh, Pen-Shu (Inventor)

1997-01-01

A pre-coding method and device for improving data compression performance by removing correlation between a first original data set and a second original data set, each having M members, respectively. The pre-coding method produces a compression-efficiency-enhancing double-difference data set. The method and device produce a double-difference data set, i.e., an adjacent-delta calculation performed on a cross-delta data set or a cross-delta calculation performed on two adjacent-delta data sets, from either one of (1) two adjacent spectral bands coming from two discrete sources, respectively, or (2) two time-shifted data sets coming from a single source. The resulting double-difference data set is then coded using either a distortionless data encoding scheme (entropy encoding) or a lossy data compression scheme. Also, a post-decoding method and device for recovering a second original data set having been represented by such a double-difference data set.

Pre-coding method and apparatus for multiple source or time-shifted single source data and corresponding inverse post-decoding method and apparatus

NASA Technical Reports Server (NTRS)

Yeh, Pen-Shu (Inventor)

1998-01-01

A pre-coding method and device for improving data compression performance by removing correlation between a first original data set and a second original data set, each having M members, respectively. The pre-coding method produces a compression-efficiency-enhancing double-difference data set. The method and device produce a double-difference data set, i.e., an adjacent-delta calculation performed on a cross-delta data set or a cross-delta calculation performed on two adjacent-delta data sets, from either one of (1) two adjacent spectral bands coming from two discrete sources, respectively, or (2) two time-shifted data sets coming from a single source. The resulting double-difference data set is then coded using either a distortionless data encoding scheme (entropy encoding) or a lossy data compression scheme. Also, a post-decoding method and device for recovering a second original data set having been represented by such a double-difference data set.

Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, A. J.

1984-01-01

The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed.

Fractional discrete-time consensus models for single- and double-summator dynamics

NASA Astrophysics Data System (ADS)

Wyrwas, Małgorzata; Mozyrska, Dorota; Girejko, Ewa

2018-04-01

The leader-following consensus problem of fractional-order multi-agent discrete-time systems is considered. In the systems, interactions between opinions are defined like in Krause and Cucker-Smale models but the memory is included by taking the fractional-order discrete-time operator on the left-hand side of the nonlinear systems. In this paper, we investigate fractional-order models of opinions for the single- and double-summator dynamics of discrete-time by analytical methods as well as by computer simulations. The necessary and sufficient conditions for the leader-following consensus are formulated by proposing a consensus control law for tracking the virtual leader.

Laser-induced periodic surface structures on 6H-SiC single crystals using temporally delayed femtosecond laser double-pulse trains

NASA Astrophysics Data System (ADS)

Song, Juan; Tao, Wenjun; Song, Hui; Gong, Min; Ma, Guohong; Dai, Ye; Zhao, Quanzhong; Qiu, Jianrong

2016-04-01

In this paper, a time-delay-adjustable double-pulse train with 800-nm wavelength, 200-fs pulse duration and a repetition rate of 1 kHz, produced by a collinear two-beam optical system like a Mach-Zehnder interferometer, was employed for irradiation of 6H-SiC crystal. The dependence of the induced structures on time delay of double-pulse train for parallel-polarization configuration was studied. The results show that as the time delay of collinear parallel-polarization dual-pulse train increased, the induced near-subwavelength ripples (NSWRs) turn from irregular rippled pattern to regularly periodic pattern and have their grooves much deepened. The characteristics timescale for this transition is about 6.24 ps. Besides, the areas of NSWR were found to decay exponentially for time delay from 0 to 1.24 ps and then slowly increase for time delay from 1.24 to 14.24 ps. Analysis shows that multiphoton ionization effect, grating-assisted surface plasmon coupling effect, and timely intervene of second pulse in a certain physical stage experienced by 6H-SiC excited upon first pulse irradiation may contribute to the transition of morphology details.

Period doubling in period-one steady states

NASA Astrophysics Data System (ADS)

Wang, Reuben R. W.; Xing, Bo; Carlo, Gabriel G.; Poletti, Dario

2018-02-01

Nonlinear classical dissipative systems present a rich phenomenology in their "route to chaos," including period doubling, i.e., the system evolves with a period which is twice that of the driving. However, typically the attractor of a periodically driven quantum open system evolves with a period which exactly matches that of the driving. Here, we analyze a periodically driven many-body open quantum system whose classical correspondent presents period doubling. We show that by studying the dynamical correlations, it is possible to show the occurrence of period doubling in the quantum (period-one) steady state. We also discuss that such systems are natural candidates for clean and intrinsically robust Floquet time crystals.

Megavolt parallel potentials arising from double-layer streams in the Earth's outer radiation belt.

PubMed

Mozer, F S; Bale, S D; Bonnell, J W; Chaston, C C; Roth, I; Wygant, J

2013-12-06

Huge numbers of double layers carrying electric fields parallel to the local magnetic field line have been observed on the Van Allen probes in connection with in situ relativistic electron acceleration in the Earth's outer radiation belt. For one case with adequate high time resolution data, 7000 double layers were observed in an interval of 1 min to produce a 230,000 V net parallel potential drop crossing the spacecraft. Lower resolution data show that this event lasted for 6 min and that more than 1,000,000 volts of net parallel potential crossed the spacecraft during this time. A double layer traverses the length of a magnetic field line in about 15 s and the orbital motion of the spacecraft perpendicular to the magnetic field was about 700 km during this 6 min interval. Thus, the instantaneous parallel potential along a single magnetic field line was the order of tens of kilovolts. Electrons on the field line might experience many such potential steps in their lifetimes to accelerate them to energies where they serve as the seed population for relativistic acceleration by coherent, large amplitude whistler mode waves. Because the double-layer speed of 3100  km/s is the order of the electron acoustic speed (and not the ion acoustic speed) of a 25 eV plasma, the double layers may result from a new electron acoustic mode. Acceleration mechanisms involving double layers may also be important in planetary radiation belts such as Jupiter, Saturn, Uranus, and Neptune, in the solar corona during flares, and in astrophysical objects.

Transient electroosmotic flow induced by DC or AC electric fields in a curved microtube.

PubMed

Luo, W-J

2004-10-15

This study investigates transient electroosmotic flow in a rectangular curved microtube in which the fluid is driven by the application of an external DC or AC electric field. The resultant flow-field evolutions within the microtube are simulated using the backwards-Euler time-stepping numerical method to clarify the relationship between the changes in the axial-flow velocity and the intensity of the applied electric field. When the electric field is initially applied or varies, the fluid within the double layer responds virtually immediately, and the axial velocity within the double layer tends to follow the varying intensity of the applied electric field. The greatest net charge density exists at the corners of the microtube as a result of the overlapping electrical double layers of the two walls. It results in local maximum or minimum axial velocities in the corners during increasing or decreasing applied electric field intensity in either the positive or negative direction. As the fluid within the double layer starts to move, the bulk fluid is gradually dragged into motion through the diffusion of momentum from the double layer. A finite time is required for the full momentum of the double layer to diffuse to the bulk fluid; hence, a certain phase shift between the applied electric field and the flow response is inevitable. The patterns of the axial velocity contours during the transient evolution are investigated in this study. It is found that these patterns are determined by the efficiency of momentum diffusion from the double layer to the central region of the microtube.

Carotid artery stenting with double cerebral embolic protection in asymptomatic patients - a diffusion-weighted MRI controlled study.

PubMed

Vuruskan, Ertan; Saracoglu, Erhan; Ergun, Ugur; Poyraz, Fatih; Duzen, İrfan Veysel

2017-01-01

The aim of this study was to compare the simultaneous double-protection method (proximal balloon plus distal filter) with distal-filter protection or proximal-balloon protection alone in asymptomatic patients during carotid artery stenting. 119 consecutive patients were investigated for carotid artery stentings in the extracranial internal carotid artery with the use of distal filters (n = 41, 34.4 %), proximal balloon (MoMa) protection (n = 40, 33.6 %) or double protection (n = 38, 31.9 %). Magnetic resonance imaging (MRI) was performed on all patients before the procedure, and control diffusion-weighted MRI (DW-MRI) was obtained within 24-48 h after the procedure. Procedural data, complications, success rate, major adverse cardiovascular events, and MRI findings were collected. New cerebral high-intensity (HI) lesions were observed in 47 (39.4 %) patients. HI lesions were observed in 22 (53.6 %), 15 (37.5 %), and 10 (26.3 %) of the patients with distal filters, proximal protection, and double protection, respectively (p = 0.004). The average number of HI lesions on DW-MRI was 1.80 in the distal-filter group, 0.90 in the proximal-balloon group, and 0.55 in the double-protection group (p < 0.001). Procedure and fluoroscopy times were slightly longer in the double-protection group compared to the distal- or proximal-protection groups (p = 0.001). The double (proximal plus distal) cerebral embolic protection technique is safe and effective for minimizing the risk of cerebral embolization, even in patients with asymptomatic carotid artery stenosis, despite slightly longer procedure and fluoroscopy times.
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A Numerical Study of the Thermal Characteristics of an Air Cavity Formed by Window Sashes in a Double Window

NASA Astrophysics Data System (ADS)

Kang, Jae-sik; Oh, Eun-Joo; Bae, Min-Jung; Song, Doo-Sam

2017-12-01

Given that the Korean government is implementing what has been termed the energy standards and labelling program for windows, window companies will be required to assign window ratings based on the experimental results of their product. Because this has added to the cost and time required for laboratory tests by window companies, the simulation system for the thermal performance of windows has been prepared to compensate for time and cost burdens. In Korea, a simulator is usually used to calculate the thermal performance of a window through WINDOW/THERM, complying with ISO 15099. For a single window, the simulation results are similar to experimental results. A double window is also calculated using the same method, but the calculation results for this type of window are unreliable. ISO 15099 should not recommend the calculation of the thermal properties of an air cavity between window sashes in a double window. This causes a difference between simulation and experimental results pertaining to the thermal performance of a double window. In this paper, the thermal properties of air cavities between window sashes in a double window are analyzed through computational fluid dynamics (CFD) simulations with the results compared to calculation results certified by ISO 15099. The surface temperature of the air cavity analyzed by CFD is compared to the experimental temperatures. These results show that an appropriate calculation method for an air cavity between window sashes in a double window should be established for reliable thermal performance results for a double window.

The influence of climate change and the timing of stratospheric warmings on Arctic ozone depletion

NASA Astrophysics Data System (ADS)

Austin, John; Butchart, Neal

1994-01-01

Satellite data are presented showing the timing of sudden warmings in the lower stratosphere during the winters 1979-1992. A three-dimensional dynamical-radiative-photochemical model is used to establish how Arctic ozone depletion will respond to a doubling of CO2 according to the timing of the warmings. In a series of idealized experiments the timing of the warmings is varied by specifying different geopotential wave amplitudes at the 316-mbar model lower boundary. Results from a "transient climate change experiment" show that the chosen wave amplitudes are appropriate for both the current and the doubled CO2 atmosphere. For doubled CO2 the experiments show that any significant risk of an Arctic ozone hole will be confined to those years with only a late stratospheric warming. In all other years the results suggest that springtime total ozone over the Arctic is more likely to increase by a small amount due to a combination of slower homogeneous chemistry and changes in transport. The predictions obtained from the idealized studies are then tested by prescribing at the model lower boundary the observed geopotential wave amplitudes from two specific years with late winter warmings. Doubling CO2 amounts produced no significant increase in ozone depletion with the 1989 wave amplitudes, but with 1990 wave amplitudes, an Arctic ozone hole occurred with minimum column of 187 Dobson Units. This contrasting response is attributed to the large midwinter pulse in the 1989 wave amplitudes compared to the less dramatic and shorter timescale fluctuations in the 1990 wave amplitudes. It is concluded that under doubled CO2 conditions an Arctic ozone hole is likely to occur in years with late stratospheric warmings following winters in which there were no significant pulses in the upper tropospheric planetary wave amplitudes.

Development and application of a double-piston configured, total-liquid ventilatory support device.

PubMed

Meinhardt, J P; Quintel, M; Hirschl, R B

2000-05-01

Perfluorocarbon liquid ventilation has been shown to enhance pulmonary mechanics and gas exchange in the setting of respiratory failure. To optimize the total liquid ventilation process, we developed a volume-limited, time-cycled liquid ventilatory support, consisting of an electrically actuated, microprocessor-controlled, double-cylinder, piston pump with two separate limbs for active inspiration and expiration. Prospective, controlled, animal laboratory study, involving sequential application of conventional gas ventilation, partial ventilation (PLV), and total liquid ventilation (TLV). Research facility at a university medical center. A total of 12 normal adult New Zealand rabbits weighing 3.25+/-0.1 kg. Anesthestized rabbits were supported with gas ventilation for 30 mins (respiratory rate, 20 cycles/min; peak inspiratory pressure, 15 cm H2O; end-expiratory pressure, 5 cm H2O), then PLV was established with perflubron (12 mL/kg). After 15 mins, TLV was instituted (tidal volume, 18 mL/kg; respiratory rate, 7 cycles/min; inspiratory/expiratory ratio, 1:2 cycles/min). After 4 hrs of TLV, PLV was re-established. Of 12 animals, nine survived the 4-hr TLV period. During TLV, mean values +/- SEM were as follows: PaO2, 363+/-30 torr; PaCO2, 39+/-1.5 torr; pH, 7.39+/-0.01; static peak inspiratory pressure, 13.2+/-0.2 cm H2O; static endexpiratory pressure, 5.5+/-0.1 cm H2O. No significant changes were observed. When compared with gas ventilation and PLV, significant increases occurred in mean arterial pressure (62.4+/-3.5 torr vs. 74.0+/-1.2 torr) and central venous pressure (5.6+/-0.7 cm H2O vs. 7.8+/-0.2 cm H2O) (p < .05). Total liquid ventilation can be performed successfully utilizing piston pumps with active expiration. Considering the enhanced flow profiles, this device configuration provides advantages over others.

Local concurrent error detection and correction in data structures using virtual backpointers

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

Li, C.C.J.; Chen, P.P.; Fuchs, W.K.

1989-11-01

A new technique, based on virtual backpointers, is presented in this paper for local concurrent error detection and correction in linked data structures. Two new data structures utilizing virtual backpointers, the Virtual Double-Linked List and the B-Tree and Virtual Backpointers, are described. For these structures, double errors within a fixed-size checking window can be detected in constant time and single errors detected during forward moves can be corrected in constant time.

Double-slit interferometry with a Bose-Einstein condensate

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

Collins, L.A.; Berman, G.P.; Bishop, A.R.

2005-03-01

A Bose-Einstein 'double-slit' interferometer has been recently realized experimentally by Y. Shin et al., Phys. Rev. Lett. 92 050405 (2004). We analyze the interferometric steps by solving numerically the time-dependent Gross-Pitaevskii equation in three-dimensional space. We focus on the adiabaticity time scales of the problem and on the creation of spurious collective excitations as a possible source of the strong degradation of the interference pattern observed experimentally. The role of quantum fluctuations is discussed.

A Double-difference Earthquake location algorithm: Method and application to the Northern Hayward Fault, California

USGS Publications Warehouse

Waldhauser, F.; Ellsworth, W.L.

2000-01-01

We have developed an efficient method to determine high-resolution hypocenter locations over large distances. The location method incorporates ordinary absolute travel-time measurements and/or cross-correlation P-and S-wave differential travel-time measurements. Residuals between observed and theoretical travel-time differences (or double-differences) are minimized for pairs of earthquakes at each station while linking together all observed event-station pairs. A least-squares solution is found by iteratively adjusting the vector difference between hypocentral pairs. The double-difference algorithm minimizes errors due to unmodeled velocity structure without the use of station corrections. Because catalog and cross-correlation data are combined into one system of equations, interevent distances within multiplets are determined to the accuracy of the cross-correlation data, while the relative locations between multiplets and uncorrelated events are simultaneously determined to the accuracy of the absolute travel-time data. Statistical resampling methods are used to estimate data accuracy and location errors. Uncertainties in double-difference locations are improved by more than an order of magnitude compared to catalog locations. The algorithm is tested, and its performance is demonstrated on two clusters of earthquakes located on the northern Hayward fault, California. There it colapses the diffuse catalog locations into sharp images of seismicity and reveals horizontal lineations of hypocenter that define the narrow regions on the fault where stress is released by brittle failure.

Short- and long-term clinical outcomes of use of beta-interferon or glatiramer acetate for people with clinically isolated syndrome: a systematic review of randomised controlled trials and network meta-analysis.

PubMed

Armoiry, X; Kan, A; Melendez-Torres, G J; Court, R; Sutcliffe, P; Auguste, P; Madan, J; Counsell, C; Clarke, A

2018-05-01

Beta-interferon (IFN-β) and glatiramer acetate (GA) have been evaluated in people with clinically isolated syndrome (CIS) with the aim to delay a second clinical attack and a diagnosis of clinically definite multiple sclerosis (CDMS). We systematically reviewed trials evaluating the short- and long-term clinical effectiveness of these drugs in CIS. We searched multiple electronic databases. We selected randomised controlled studies (RCTs) conducted in CIS patients and where the interventions were IFN-β and GA. Main outcomes were time to CDMS, and discontinuation due to adverse events (AE). We compared interventions using random-effect network meta-analyses (NMA). We also reported outcomes from long-term open-label extension (OLE) studies. We identified five primary studies. Four had open-label extensions following double-blind periods comparing outcomes between early vs delayed DMT. Short-term clinical results (double-blind period) showed that all drugs delayed CDMS compared to placebo. Indirect comparisons did not suggest superiority of any one active drug over another. We could not undertake a NMA for discontinuation due to AE. Long-term clinical results (OLE studies) showed that the risk of developing CDMS was consistently reduced across studies after early DMT treatment compared to delayed DMT (HR = 0.64, 95% CI 0.55, 0.74). No data supported the benefit of DMTs in reducing the time to, and magnitude of, disability progression. Meta-analyses confirmed that IFN-β and GA delay time to CDMS compared to placebo. In the absence of evidence that early DMTs can reduce disability progression, future research is needed to better identify patients most likely to benefit from long-term DMTs.

Prenatal omega-3 fatty acid supplementation does not affect offspring telomere length and F2-isoprostanes at 12 years: A double blind, randomized controlled trial.

PubMed

See, V H L; Mas, E; Burrows, S; O'Callaghan, N J; Fenech, M; Prescott, S L; Beilin, L J; Huang, R C; Mori, T A

2016-09-01

Oxidative stress and nutritional deficiency may influence the excessive shortening of the telomeric ends of chromosomes. It is known that stress exposure in intrauterine life can produce variations in telomere length (TL), thereby potentially setting up a long-term trajectory for disease susceptibility. To assess the effect of omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation during pregnancy on telomere length and oxidative stress in offspring at birth and 12 years of age (12y). In a double-blind, placebo-controlled, parallel-group study, 98 pregnant atopic women were randomised to 4g/day of n-3 LCPUFA or control (olive oil [OO]), from 20 weeks gestation until delivery. Telomere length as a marker of cell senescence and plasma and urinary F2-isoprostanes as a marker of oxidative stress were measured in the offspring at birth and 12y. Maternal n-3 LCPUFA supplementation did not influence offspring telomere length at birth or at 12y with no changes over time. Telomere length was not associated with F2-isoprostanes or erythrocyte total n-3 fatty acids. Supplementation significantly reduced cord plasma F2-isoprostanes (P<0.001), with a difference in the change over time between groups (P=0.05). However, the differences were no longer apparent at 12y. Between-group differences for urinary F2-isoprostanes at birth and at 12y were non-significant with no changes over time. This study does not support the hypothesis that n-3 LCPUFA during pregnancy provides sustained effects on postnatal oxidative stress and telomere length as observed in the offspring. Copyright © 2016 Elsevier Ltd. All rights reserved.

Visual PEF Reader - VIPER

NASA Technical Reports Server (NTRS)

Luo, Victor; Khanampornpan, Teerapat; Boehmer, Rudy A.; Kim, Rachel Y.

2011-01-01

This software graphically displays all pertinent information from a Predicted Events File (PEF) using the Java Swing framework, which allows for multi-platform support. The PEF is hard to weed through when looking for specific information and it is a desire for the MRO (Mars Reconn aissance Orbiter) Mission Planning & Sequencing Team (MPST) to have a different way to visualize the data. This tool will provide the team with a visual way of reviewing and error-checking the sequence product. The front end of the tool contains much of the aesthetically appealing material for viewing. The time stamp is displayed in the top left corner, and highlighted details are displayed in the bottom left corner. The time bar stretches along the top of the window, and the rest of the space is allotted for blocks and step functions. A preferences window is used to control the layout of the sections along with the ability to choose color and size of the blocks. Double-clicking on a block will show information contained within the block. Zooming into a certain level will graphically display that information as an overlay on the block itself. Other functions include using hotkeys to navigate, an option to jump to a specific time, enabling a vertical line, and double-clicking to zoom in/out. The back end involves a configuration file that allows a more experienced user to pre-define the structure of a block, a single event, or a step function. The individual will have to determine what information is important within each block and what actually defines the beginning and end of a block. This gives the user much more flexibility in terms of what the tool is searching for. In addition to the configurability, all the settings in the preferences window are saved in the configuration file as well

An abnormal bone marrow microenvironment contributes to hematopoietic dysfunction in Fanconi anemia.

PubMed

Zhou, Yuan; He, Yongzheng; Xing, Wen; Zhang, Peng; Shi, Hui; Chen, Shi; Shi, Jun; Bai, Jie; Rhodes, Steven D; Zhang, Fengqui; Yuan, Jin; Yang, Xianlin; Zhu, Xiaofan; Li, Yan; Hanenberg, Helmut; Xu, Mingjiang; Robertson, Kent A; Yuan, Weiping; Nalepa, Grzegorz; Cheng, Tao; Clapp, D Wade; Yang, Feng-Chun

2017-06-01

Fanconi anemia is a complex heterogeneous genetic disorder with a high incidence of bone marrow failure, clonal evolution to acute myeloid leukemia and mesenchymal-derived congenital anomalies. Increasing evidence in Fanconi anemia and other genetic disorders points towards an interdependence of skeletal and hematopoietic development, yet the impact of the marrow microenvironment in the pathogenesis of the bone marrow failure in Fanconi anemia remains unclear. Here we demonstrated that mice with double knockout of both Fancc and Fancg genes had decreased bone formation at least partially due to impaired osteoblast differentiation from mesenchymal stem/progenitor cells. Mesenchymal stem/progenitor cells from the double knockout mice showed impaired hematopoietic supportive activity. Mesenchymal stem/progenitor cells of patients with Fanconi anemia exhibited similar cellular deficits, including increased senescence, reduced proliferation, impaired osteoblast differentiation and defective hematopoietic stem/progenitor cell supportive activity. Collectively, these studies provide unique insights into the physiological significance of mesenchymal stem/progenitor cells in supporting the marrow microenvironment, which is potentially of broad relevance in hematopoietic stem cell transplantation. Copyright© Ferrata Storti Foundation.

An abnormal bone marrow microenvironment contributes to hematopoietic dysfunction in Fanconi anemia

PubMed Central

Zhou, Yuan; He, Yongzheng; Xing, Wen; Zhang, Peng; Shi, Hui; Chen, Shi; Shi, Jun; Bai, Jie; Rhodes, Steven D.; Zhang, Fengqui; Yuan, Jin; Yang, Xianlin; Zhu, Xiaofan; Li, Yan; Hanenberg, Helmut; Xu, Mingjiang; Robertson, Kent A.; Yuan, Weiping; Nalepa, Grzegorz; Cheng, Tao; Clapp, D. Wade; Yang, Feng-Chun

2017-01-01

Fanconi anemia is a complex heterogeneous genetic disorder with a high incidence of bone marrow failure, clonal evolution to acute myeloid leukemia and mesenchymal-derived congenital anomalies. Increasing evidence in Fanconi anemia and other genetic disorders points towards an interdependence of skeletal and hematopoietic development, yet the impact of the marrow microenvironment in the pathogenesis of the bone marrow failure in Fanconi anemia remains unclear. Here we demonstrated that mice with double knockout of both Fancc and Fancg genes had decreased bone formation at least partially due to impaired osteoblast differentiation from mesenchymal stem/progenitor cells. Mesenchymal stem/progenitor cells from the double knockout mice showed impaired hematopoietic supportive activity. Mesenchymal stem/progenitor cells of patients with Fanconi anemia exhibited similar cellular deficits, including increased senescence, reduced proliferation, impaired osteoblast differentiation and defective hematopoietic stem/progenitor cell supportive activity. Collectively, these studies provide unique insights into the physiological significance of mesenchymal stem/progenitor cells in supporting the marrow microenvironment, which is potentially of broad relevance in hematopoietic stem cell transplantation. PMID:28341737

A novel control strategy for enhancing the LVRT and voltage support capabilities of DFIG

NASA Astrophysics Data System (ADS)

Shen, Yangwu; Zhang, Bin; Liang, Liqing; Cui, Ting

2018-02-01

A novel integrated control strategy is proposed in this paper to enhance the low voltage ride through capacity for the double-fed induction generator by equipping an energy storage system. The energy storage system is installed into the DC-link capacitor of the DFIG and used to control the DC-link voltage during normal or transient operations. The energy storage device will absorb or compensate the power difference between the captured wind power and the power injected to the grid during the normal and transient period, and the grid side converter can be free from maintaining the voltage stability of the DC-link capacitor. Thus, the grid-side converter is changed to reactive power support while the rotor-side converter is used to control the maximum power production during normal operation. The grid-side converter and rotor-side converter will act as reactive power sources to further enhance the voltage support capability of double-fed induction generator during the transient period. Numerical Simulation are performed to validate the effectiveness of the proposed control designs.

Catalytic coupling of sp2- and sp-hybridized carbon-hydrogen bonds with vinylmetalloid compounds.

PubMed

Marciniec, Bogdan

2007-10-01

In the Account given herein, it has been shown that silylative coupling of olefins, well-recognized as a new catalytic route for the activation of double bond C-H bond of olefins and double bond C-Si bond of vinylsilicon compounds with ethylene elimination, can be extended over both other vinylmetalloid derivatives (double bond C-E) (where E = Ge, B, and others) as well as the activation of triple bond C-H, double bond C aryl-H, and -O-H bond of alcohols and silanols. This general transformation is catalyzed by transition-metal complexes (mainly Ru and Rh) containing or initiating TM-H and/or TM-E bonds (inorganometallics). This new general catalytic route for the activation of double bond C-H and triple bond C-H as well as double bond C-E bonds called metallative coupling or trans-metalation (cross-coupling, ring-closing, and polycondensation) constitutes an efficient method (complementary to metathesis) for stereo- and regioselective synthesis of a variety of molecular and macromolecular compounds of vinyl-E (E = Si, B, and Ge) and ethynyl-E (E = Si and Ge) functionality, also potent organometallic reagents for efficient synthesis of highly pi-conjugated organic compounds. The mechanisms of the catalysis of this deethenative metalation have been supported by equimolar reactions of TM-H and/or TM-E with initial substances and reactions with deuterium-labeled reagents.

Building Double-decker Traps for Early Detection of Emerald Ash Borer.

PubMed

McCullough, Deborah G; Poland, Therese M

2017-10-04

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions of forest and landscape ash (Fraxinus spp.) trees. Several artificial trap designs to attract and capture EAB beetles have been developed to detect, delineate, and monitor infestations. Double-decker (DD) traps consist of two corrugated plastic prisms, one green and one purple, attached to a 3 m tall polyvinyl chloride (PVC) pipe supported by a t-post. The green prism at the top of the PVC pipe is baited with cis-3-hexenol, a compound produced by ash foliage. Surfaces of both prisms are coated with sticky insect glue to capture adult EAB beetles. Double-decker traps should be placed near ash trees but in open areas, exposed to sun. Double-decker trap construction and placement are presented here, along with a summary of field experiments demonstrating the efficacy of DD traps in capturing EAB beetles. In a recent study in sites with relatively low EAB densities, double-decker traps captured significantly more EAB than green or purple prism traps or green funnel traps, all of which are designed to be suspended from a branch in the canopy of ash trees. A greater percentage of double decker traps were positive, i.e., captured at least one EAB, than the prism traps or funnel traps that were hung in ash tree canopies.

Science, politics, and the GM debate in Europe.

PubMed

Tencalla, Francesca

2006-02-01

Europe today stands at a crossroad, facing challenges but also opportunities. In its intent to make Europe a leading technology-based economy by 2010, the European Commission has identified biotechnology and genomics as fields for future growth, crucial for supporting the agricultural and food processing industry. Since first commercialization in 1996, GM crop areas have grown at double-digit rates, making this one of the most rapidly adopted technologies in agriculture. However, in contrast to other world areas and despite European Commission support, Europe has found itself 'bogged-down' in a polemic between opponents and supporters of plant biotechnology. As a result, planted areas have remained small. This stalemate is due to a lack of political leadership, especially at the Member State level, all the more surprising in light of European early development and competitive advantage with crop biotechnology. This situation proves once again that, for cutting-edge innovations, a solid science base alone is not sufficient. Acceptance or rejection of new technologies depends on interlinked political, economic, and societal factors that create a favorable or unfavorable situation at a given time. This article will look at GM crops in Europe and the role science and politics have played in the introduction of crop biotechnology.

War and Well-Being: The Association between Forgiveness, Social Support, Posttraumatic Stress Disorder, and Well-Being during and after War.

PubMed

Weinberg, Michael; Harel, Hila; Shamani, Michal; Or-Chen, Keren; Ron, Pnina; Gil, Sharon

2017-10-01

Exposure to war can lead to numerous traumatic experiences affecting the daily lives and personal well-being of the civilian population. However, no research to date has examined the associations between postwar well-being and posttraumatic stress disorder (PTSD) symptoms, tendency to forgive, and social support during and following war. Authors examined a sample of 160 Israeli civilians who were exposed to rocket and missile fire during the 2014 Gaza War. Time 1 (Tl) started approximately one week after the beginning of the war and ended four weeks later following the first 72-hour ceasefire declaration by the United Nations. Respondents were re-approached by personal e-mail approximately one month after T1. A structural equation model design showed that higher postwar tendency to forgive, and social support, are associated with higher postwar well-being. It is notable that higher social support during the war had a negative effect on postwar well-being. In addition, higher posttraumatic symptoms and well-being during the war had a positive effect on higher postwar well-being. The study findings reinforce the importance of personal variables in postwar well-being. However, increased awareness of both social support and PTSD symptoms as "double-edged sword" resources is advisable, considering the different effects of social support and PTSD symptoms on well-being both during and after the war. © 2017 National Association of Social Workers.

Hypersonic Induced Interactions of Plasma and Non-Plasma Jets

DTIC Science & Technology

2006-06-12

kHz, and an output transformer cascade which transforms the voltage to up to 76 kVpp. The burst pulses of the pulse control board are controlled by a...flow condition have imposed the use of a double- pulse laser system with a pulse separation time in the microsecond range. The PIV image acquisition...system utilises a double-cavity Nd:YAG Litron Laser with a pulse energy of 2 x 200 mJ. The beams are frequency doubled to a wavelength of 532 nm and

The double power law in human collaboration behavior: The case of Wikipedia

NASA Astrophysics Data System (ADS)

Kwon, Okyu; Son, Woo-Sik; Jung, Woo-Sung

2016-11-01

We study human behavior in terms of the inter-event time distribution of revision behavior on Wikipedia, an online collaborative encyclopedia. We observe a double power law distribution for the inter-editing behavior at the population level and a single power law distribution at the individual level. Although interactions between users are indirect or moderate on Wikipedia, we determine that the synchronized editing behavior among users plays a key role in determining the slope of the tail of the double power law distribution.

Timing Recollision in Nonsequential Double Ionization by Intense Elliptically Polarized Laser Pulses.

PubMed

Kang, H; Henrichs, K; Kunitski, M; Wang, Y; Hao, X; Fehre, K; Czasch, A; Eckart, S; Schmidt, L Ph H; Schöffler, M; Jahnke, T; Liu, X; Dörner, R

2018-06-01

We examine correlated electron and doubly charged ion momentum spectra from strong field double ionization of neon employing intense elliptically polarized laser pulses. An ellipticity-dependent asymmetry of correlated electron and ion momentum distributions has been observed. Using a 3D semiclassical model, we demonstrate that our observations reflect the subcycle dynamics of the recollision process. Our Letter reveals a general physical picture for recollision impact double ionization with elliptical polarization and demonstrates the possibility of ultrafast control of the recollision dynamics.

Timing Recollision in Nonsequential Double Ionization by Intense Elliptically Polarized Laser Pulses

NASA Astrophysics Data System (ADS)

Kang, H.; Henrichs, K.; Kunitski, M.; Wang, Y.; Hao, X.; Fehre, K.; Czasch, A.; Eckart, S.; Schmidt, L. Ph. H.; Schöffler, M.; Jahnke, T.; Liu, X.; Dörner, R.

2018-06-01

We examine correlated electron and doubly charged ion momentum spectra from strong field double ionization of neon employing intense elliptically polarized laser pulses. An ellipticity-dependent asymmetry of correlated electron and ion momentum distributions has been observed. Using a 3D semiclassical model, we demonstrate that our observations reflect the subcycle dynamics of the recollision process. Our Letter reveals a general physical picture for recollision impact double ionization with elliptical polarization and demonstrates the possibility of ultrafast control of the recollision dynamics.

Development of a large low-cost double-chamber vacuum laminator

NASA Technical Reports Server (NTRS)

Burger, D. R.

1983-01-01

A double-chamber vacuum laminator was required to investigate the processing and control of the fabrication of large terrestrial photovoltaic modules, and economic problems arising therefrom. Major design considerations were low cost, process flexibility and the exploration of novel equipment approaches. Spherical end caps for industrial tanks were used for the vacuum chambers. A stepping programmer and adjustable timers were used for process flexibility. New processing options were obtained by use of vacuum sensors. The upper vacuum chamber was provided with a diaphragm support to reduce diaphragm stress. A counterweight was used for handling ease and safety. Heat was supplied by a large electrical strip heater. Thermal isolation and mechanical support were provided inexpensively by a bed of industrial marbles. Operational testing disclosed the need for a differential vacuum gauge and proportional valve. Reprogramming of the process control system was simple and quick.

Immobilizing Highly Catalytically Active Pt Nanoparticles inside the Pores of Metal-Organic Framework: A Double Solvents Approach

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

Aijaz, Arshad; Karkamkar, Abhijeet J.; Choi, Young Joon

2012-08-29

Ultrafine Pt nanoparticles were successfully immobilized inside the pores of a metal-organic framework MIL-101 without deposition of Pt nanoparticles on the external surfaces of framework by using a 'double solvents' method. The resulting Pt@MIL-101 composites with different Pt loadings represent the first highly active MOF-immobilized metal nanocatalysts for catalytic reactions in all three phases: liquid-phase ammonia borane hydrolysis; solid-phase ammonia borane thermal dehy-drogenation and gas-phase CO oxidation. The observed excellent catalytic performances are at-tributed to the small Pt nanoparticles within the pores of MIL-101. 'We are thankful to AIST and METI for financial support. TA & AK are thankful formore » support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. PNNL is operated by Battelle.'« less

Computational NMR, IR/RAMAN calculations in sodium pravastatin: Investigation of the Self-Assembled Nanostructure of Pravastatin-LDH (Layered Double Hydroxides) Systems

NASA Astrophysics Data System (ADS)

Petersen, Philippe; Cunha, Vanessa; Gonçalves, Marcos; Petrilli, Helena; Constantino, Vera; Instituto de Física, Departamento de Física de Materiais e Mecânica Team; Instituto de Química, Departamento de Química Fundamental Team

2013-03-01

Layered double hydroxides (LDH) can be used as nanocontainers for immobilization of Pravastatin, in order to obtain suitable drug carriers. The material's structure and spectroscopic properties were analyzed by NMR, IR/RAMAN and supported by theoretical calculations. Density Functional Theory (DFT) calculations were performed using the Gaussian03 package. The geometry optimizations were performed considering the single crystal X-ray diffraction data of tert-octylamonium salt of Pravastatin. Tetramethylsilane (TMS), obtained with the same basis set, was used as reference for calculating the chemical shift of 13C. A scaling factor was used to compare theoretical and experimental harmonic vibrational frequencies. Through the NMR and IR/RAMAN spectra, we were able to make precise assignments of the NMR and IR/RAMAN of Sodium Pravastatin. We acknowledge support from CAPES, INEO and CNPQ.

Diameter of the useful diffraction halo in double-exposure speckle photographs recorded under various conditions

NASA Astrophysics Data System (ADS)

Alejo, A.; Marti, L.; Moreno, A.; Ostrovskii, Iu. I.; Serra, R.

1985-06-01

Consideration is given to the relationship between the diffraction halo radius Theta(h) and the displacement (Delta) of the object in double exposed speckle photographs taken in various conditions. The numerical values of Theta(h)/Delta were obtained for several speckle recordings having exposure times in the range 0.5-3.8 s. It is shown that long exposure times did not significantly decrease the minimum measureable displacement of the object. The radii of the diffraction halo were the same in the case of both long and short exposure times.

Space confinement and rotation stress induced self-organization of double-helix nanostructure: a nanotube twist with a moving catalyst head.

PubMed

Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Huang, Jia-Qi; Wei, Fei

2012-05-22

Inorganic materials with double-helix structure have attracted intensive attention due to not only their elegant morphology but also their amazing morphology-related potential applications. The investigation on the formation mechanism of the inorganic double-helix nanostructure is the first step for the fundamental studies of their materials or physical properties. Herein, we demonstrated the space confinement and rotation stress induced self-organization mechanism of the carbon nanotube (CNT)-array double helices under scanning electron microscopy by directly observing their formation process from individual layered double hydroxide flakes, which is a kind of hydrotalcite-like material composed of positively charged layers and charge-balancing interlayer anions. Space confinement is considered to be the most important extrinsic factor for the formation of CNT-array double helices. Synchronous growth of the CNT arrays oppositely from LDH flakes with space confinement on both sides at the same time is essential for the growth of CNT-array double helices. Coiling of the as-grown CNT arrays into double helices will proceed by self-organization, tending to the most stable morphology in order to release their internal rotation stress. Based on the demonstrated mechanism, effective routes were carried out to improve the selectivity for CNT-array double helices. The work provides a promising method for the fabrication of double-helix nanostructures with their two helices connected at the end by self-assembly.

Diffuse-charge dynamics of ionic liquids in electrochemical systems.

PubMed

Zhao, Hui

2011-11-01

We employ a continuum theory of solvent-free ionic liquids accounting for both short-range electrostatic correlations and steric effects (finite ion size) [Bazant et al., Phys. Rev. Lett. 106, 046102 (2011)] to study the response of a model microelectrochemical cell to a step voltage. The model problem consists of a 1-1 symmetric ionic liquid between two parallel blocking electrodes, neglecting any transverse transport phenomena. Matched asymptotic expansions in the limit of thin double layers are applied to analyze the resulting one-dimensional equations and study the overall charge-time relation in the weakly nonlinear regime. One important conclusion is that our simple scaling analysis suggests that the length scale √(λ*(D)l*(c)) accurately characterizes the double-layer structure of ionic liquids with strong electrostatic correlations where l*(c) is the electrostatic correlation length (in contrast, the Debye screening length λ*(D) is the primary double-layer length for electrolytes) and the response time of λ(D)(*3/2)L*/(D*l(c)(1/2)) (not λ*(D)L*/D* that is the primary charging time of electrolytes) is the correct charging time scale of ionic liquids with strong electrostatic correlations where D* is the diffusivity and L* is the separation length of the cell. With these two new scales, data of both electric potential versus distance from the electrode and the total diffuse charge versus time collapse onto each individual master curve in the presence of strong electrostatic correlations. In addition, the dependance of the total diffuse charge on steric effects, short-range correlations, and driving voltages is thoroughly examined. The results from the asymptotic analysis are compared favorably with those from full numerical simulations. Finally, the absorption of excess salt by the double layer creates a depletion region outside the double layer. Such salt depletion may bring a correction to the leading order terms and break down the weakly nonlinear analysis. A criterion which justifies the weakly nonlinear analysis is verified with numerical simulations.

Modified neural networks for rapid recovery of tokamak plasma parameters for real time control

NASA Astrophysics Data System (ADS)

Sengupta, A.; Ranjan, P.

2002-07-01

Two modified neural network techniques are used for the identification of the equilibrium plasma parameters of the Superconducting Steady State Tokamak I from external magnetic measurements. This is expected to ultimately assist in a real time plasma control. As different from the conventional network structure where a single network with the optimum number of processing elements calculates the outputs, a multinetwork system connected in parallel does the calculations here in one of the methods. This network is called the double neural network. The accuracy of the recovered parameters is clearly more than the conventional network. The other type of neural network used here is based on the statistical function parametrization combined with a neural network. The principal component transformation removes linear dependences from the measurements and a dimensional reduction process reduces the dimensionality of the input space. This reduced and transformed input set, rather than the entire set, is fed into the neural network input. This is known as the principal component transformation-based neural network. The accuracy of the recovered parameters in the latter type of modified network is found to be a further improvement over the accuracy of the double neural network. This result differs from that obtained in an earlier work where the double neural network showed better performance. The conventional network and the function parametrization methods have also been used for comparison. The conventional network has been used for an optimization of the set of magnetic diagnostics. The effective set of sensors, as assessed by this network, are compared with the principal component based network. Fault tolerance of the neural networks has been tested. The double neural network showed the maximum resistance to faults in the diagnostics, while the principal component based network performed poorly. Finally the processing times of the methods have been compared. The double network and the principal component network involve the minimum computation time, although the conventional network also performs well enough to be used in real time.

Photobiomodulation with non-thermal lasers: Mechanisms of action and therapeutic uses in dermatology and aesthetic medicine.

PubMed

Nestor, Mark; Andriessen, Anneke; Berman, Brian; Katz, Bruce E; Gilbert, Dore; Goldberg, David J; Gold, Michael H; Kirsner, Robert S; Lorenc, Paul Z

2017-08-01

Non-thermal laser therapy in dermatology, is a growing field in medical technology by which therapeutic effects are achieved by exposing tissues to specific wavelengths of light. The purpose of this review was to gain a better understanding of the science behind non-thermal laser and the evidence supporting its use in dermatology. A group of dermatologists and surgeons recently convened to review the evidence supporting the use of non-thermal laser for body sculpting, improving the appearance of cellulite, and treating onychomycosis. The use of non-thermal laser for body sculpting is supported by three randomized, double-blind, sham-controlled studies (N = 161), one prospective open-label study (N = 54), and two retrospective studies (N = 775). Non-thermal laser application for improving the appearance of cellulite is supported by one randomized, double-blind, sham-controlled study (N = 38). The use of non-thermal laser for the treatment of onychomycosis is supported by an analysis of three non-randomized, open-label studies demonstrating clinical improvement of nails (N = 292). Non-thermal laser is steadily moving into mainstream medical practice, such as dermatology. Although present studies have demonstrated the safety and efficacy of non-thermal laser for body sculpting, cellulite reduction and onychomycosis treatment, studies demonstrating the efficacy of non-thermal laser as a stand-alone procedure are still inadequate.

Advanced Doubling Adding Method for Radiative Transfer in Planetary Atmospheres

NASA Astrophysics Data System (ADS)

Liu, Quanhua; Weng, Fuzhong

2006-12-01

The doubling adding method (DA) is one of the most accurate tools for detailed multiple-scattering calculations. The principle of the method goes back to the nineteenth century in a problem dealing with reflection and transmission by glass plates. Since then the doubling adding method has been widely used as a reference tool for other radiative transfer models. The method has never been used in operational applications owing to tremendous demand on computational resources from the model. This study derives an analytical expression replacing the most complicated thermal source terms in the doubling adding method. The new development is called the advanced doubling adding (ADA) method. Thanks also to the efficiency of matrix and vector manipulations in FORTRAN 90/95, the advanced doubling adding method is about 60 times faster than the doubling adding method. The radiance (i.e., forward) computation code of ADA is easily translated into tangent linear and adjoint codes for radiance gradient calculations. The simplicity in forward and Jacobian computation codes is very useful for operational applications and for the consistency between the forward and adjoint calculations in satellite data assimilation.

[A case of double monster--duplicitas anterior with diprosopia].

PubMed

Meyer, R

1983-01-01

Report on a delivery of a double monster, duplicitas anterior with diprosopia. The course of delivery is compared with literature. The exclusion of malformations in early pregnancy is possible and necessary. Perinatal mortality can be reduced by abortion in time. The psychic burden of women concerned needs a special regard.

High correlation of double Debye model parameters in skin cancer detection.

PubMed

Truong, Bao C Q; Tuan, H D; Fitzgerald, Anthony J; Wallace, Vincent P; Nguyen, H T

2014-01-01

The double Debye model can be used to capture the dielectric response of human skin in terahertz regime due to high water content in the tissue. The increased water proportion is widely considered as a biomarker of carcinogenesis, which gives rise of using this model in skin cancer detection. Therefore, the goal of this paper is to provide a specific analysis of the double Debye parameters in terms of non-melanoma skin cancer classification. Pearson correlation is applied to investigate the sensitivity of these parameters and their combinations to the variation in tumor percentage of skin samples. The most sensitive parameters are then assessed by using the receiver operating characteristic (ROC) plot to confirm their potential of classifying tumor from normal skin. Our positive outcomes support further steps to clinical application of terahertz imaging in skin cancer delineation.

A method for generating double-ring-shaped vector beams

NASA Astrophysics Data System (ADS)

Huan, Chen; Xiao-Hui, Ling; Zhi-Hong, Chen; Qian-Guang, Li; Hao, Lv; Hua-Qing, Yu; Xu-Nong, Yi

2016-07-01

We propose a method for generating double-ring-shaped vector beams. A step phase introduced by a spatial light modulator (SLM) first makes the incident laser beam have a nodal cycle. This phase is dynamic in nature because it depends on the optical length. Then a Pancharatnam-Berry phase (PBP) optical element is used to manipulate the local polarization of the optical field by modulating the geometric phase. The experimental results show that this scheme can effectively create double-ring-shaped vector beams. It provides much greater flexibility to manipulate the phase and polarization by simultaneously modulating the dynamic and the geometric phases. Project supported by the National Natural Science Foundation of China (Grant No. 11547017), the Hubei Engineering University Research Foundation, China (Grant No. z2014001), and the Natural Science Foundation of Hubei Province, China (Grant No. 2014CFB578).

Reliability of spatial-temporal gait parameters during dual-task interference in people with multiple sclerosis. A cross-sectional study.

PubMed

Monticone, Marco; Ambrosini, Emilia; Fiorentini, Roberta; Rocca, Barbara; Liquori, Valentina; Pedrocchi, Alessandra; Ferrante, Simona

2014-09-01

To evaluate the reliability and minimum detectable change (MDC) of spatial-temporal gait parameters in subjects with multiple sclerosis (MS) during dual tasking. This cross-sectional study involved 25 healthy subjects (mean age 49.9 ± 15.8 years) and 25 people with MS (mean age 49.2 ± 11.5 years). Gait under motor-cognitive and motor-motor dual tasking conditions was evaluated in two sessions separated by a one-day interval using the GAITRite Walkway System. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and coefficients of variation (CV). MDC scores were computed for the velocity, cadence, step and stride length, step and stride time, double support time, the % of gait cycle for single support and stance phase, and base of support. All of the gait parameters reported good to excellent ICCs under both conditions, with healthy subject values of >0.69 and MS subject values of >0.84. SEM values were always below 18% for both groups of subjects. The gait patterns of the people with MS were slightly more variable than those of the normal controls (CVs: 5.88-41.53% vs 2.84-30.48%). The assessment of quantitative gait parameters in healthy subjects and people with MS is highly reliable under both of the investigated dual tasking conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Cleveland, K. Michael; VanDeMark, Thomas F.; Ammon, Charles J.

We report that double-difference methods applied to cross-correlation measured Rayleigh wave time shifts are an effective tool to improve epicentroid locations and relative origin time shifts in remote regions. We apply these methods to seismicity offshore of southwestern Canada and the U.S. Pacific Northwest, occurring along the boundaries of the Pacific and Juan de Fuca (including the Explorer Plate and Gorda Block) Plates. The Blanco, Mendocino, Revere-Dellwood, Nootka, and Sovanco fracture zones host the majority of this seismicity, largely consisting of strike-slip earthquakes. The Explorer, Juan de Fuca, and Gorda spreading ridges join these fracture zones and host normal faultingmore » earthquakes. Our results show that at least the moderate-magnitude activity clusters along fault strike, supporting suggestions of large variations in seismic coupling along oceanic transform faults. Our improved relative locations corroborate earlier interpretations of the internal deformation in the Explorer and Gorda Plates. North of the Explorer Plate, improved locations support models that propose northern extension of the Revere-Dellwood fault. Relocations also support interpretations that favor multiple parallel active faults along the Blanco Transform Fault Zone. Seismicity of the western half of the Blanco appears more scattered and less collinear than the eastern half, possibly related to fault maturity. We use azimuthal variations in the Rayleigh wave cross-correlation amplitude to detect and model rupture directivity for a moderate size earthquake along the eastern Blanco Fault. Lastly, the observations constrain the seismogenic zone geometry and suggest a relatively narrow seismogenic zone width of 2 to 4 km.« less

Starship Life Support

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2009-01-01

The design and mass cost of a starship and its life support system are investigated. The mission plan for a multi generational interstellar voyage to colonize a new planet is used to describe the starship design, including the crew habitat, accommodations, and life support. Only current technology is assumed. Highly reliable life support systems can be provided with reasonably small additional mass, suggesting that they can support long duration missions. Bioregenerative life support, growing crop plants that provide food, water, and oxygen, has been thought to need less mass than providing stored food for long duration missions. The large initial mass of hydroponics systems is paid for over time by saving the mass of stored food. However, the yearly logistics mass required to support a bioregenerative system exceeds the mass of food solids it produces, so that supplying stored dehydrated food always requires less mass than bioregenerative food production. A mixed system that grows about half the food and supplies the other half dehydrated has advantages that allow it to breakeven with stored dehydrated food in about 66 years. However, moderate increases in the hydroponics system mass to achieve high reliability, such as adding spares that double the system mass and replacing the initial system every 100 years, increase the mass cost of bioregenerative life support. In this case, the high reliability half food growing, half food supplying system does not breakeven for 389 years. An even higher reliability half and half system, with three times original system mass and replacing the system every 50 years, never breaks even. Growing food for starship life support requires more mass than providing dehydrated food, even for multigeneration voyages of hundreds of years. The benefits of growing some food may justify the added mass cost. Much more efficient recycling food production is wanted but may not be possible. A single multigenerational interstellar voyage to colonize a new planet would have cost similar to that of the Apollo program. Cost is reduced if a small crew travels slowly and lands with minimal equipment. We can go to the stars!

Radiation-induced effects on the mechanical properties of natural ZrSiO4: double cascade-overlap damage accumulation

NASA Astrophysics Data System (ADS)

Beirau, Tobias; Nix, William D.; Pöllmann, Herbert; Ewing, Rodney C.

2018-05-01

Several different models are known to describe the structure-dependent radiation-induced damage accumulation process in materials (e.g. Gibbons Proc IEEE 60:1062-1096, 1972; Weber Nuc Instr Met Phys Res B 166-167:98-106, 2000). In the literature, two different models of damage accumulation due to α-decay events in natural ZrSiO4 (zircon) have been described. The direct impact damage accumulation model is based on amorphization occurring directly within the collision cascade. However, the double cascade-overlap damage accumulation model predicts that amorphization will only occur due to the overlap of disordered domains within the cascade. By analyzing the dose-dependent evolution of mechanical properties (i.e., Poisson's ratios, compliance constants, elastic modulus, and hardness) as a measure of the increasing amorphization, we provide support for the double cascade-overlap damage accumulation model. We found no evidence to support the direct impact damage accumulation model. Additionally, the amount of radiation damage could be related to an anisotropic-to-isotropic transition of the Poisson's ratio for stress along and perpendicular to the four-fold c-axis and of the related compliance constants of natural U- and Th-bearing zircon. The isotropification occurs in the dose range between 3.1 × and 6.3 × 1018 α-decays/g.

Radiation-induced effects on the mechanical properties of natural ZrSiO4: double cascade-overlap damage accumulation

NASA Astrophysics Data System (ADS)

Beirau, Tobias; Nix, William D.; Pöllmann, Herbert; Ewing, Rodney C.

2017-11-01

Several different models are known to describe the structure-dependent radiation-induced damage accumulation process in materials (e.g. Gibbons Proc IEEE 60:1062-1096, 1972; Weber Nuc Instr Met Phys Res B 166-167:98-106, 2000). In the literature, two different models of damage accumulation due to α-decay events in natural ZrSiO4 (zircon) have been described. The direct impact damage accumulation model is based on amorphization occurring directly within the collision cascade. However, the double cascade-overlap damage accumulation model predicts that amorphization will only occur due to the overlap of disordered domains within the cascade. By analyzing the dose-dependent evolution of mechanical properties (i.e., Poisson's ratios, compliance constants, elastic modulus, and hardness) as a measure of the increasing amorphization, we provide support for the double cascade-overlap damage accumulation model. We found no evidence to support the direct impact damage accumulation model. Additionally, the amount of radiation damage could be related to an anisotropic-to-isotropic transition of the Poisson's ratio for stress along and perpendicular to the four-fold c-axis and of the related compliance constants of natural U- and Th-bearing zircon. The isotropification occurs in the dose range between 3.1 × and 6.3 × 1018 α-decays/g.

Identity, Peer Relationships, and Adolescent Girls’ Sexual Behavior: An Exploration of the Contemporary Double Standard

PubMed Central

Lyons, Heidi; Giordano, Peggy; Manning, Wendy; Longmore, Monica

2011-01-01

The idea of a sexual double standard emphasizes that men have more sexual freedom, while women are subject to social sanctions for the same behaviors. The current research uses a sample of adolescent women to examine the social consequences of reporting a greater number of sex partners. We explore the broader social costs and low self-worth associated with a high number of sex partners, and also focus on characteristics of the adolescents’ close friends. The analyses of quantitative data (n=600) provide support for the emphasis on the adolescents’ immediate network of friends: friends’ attitudes and behaviors were significant predictors of respondents’ own sexual experience, while those reporting a higher number of sex partners did not report a lack of popularity, desire for more friends, or lower self-esteem. In-depth relationship history narratives collected from a subset of respondents (n=46) provide additional context for the quantitative results. Women often recognized the existence of a double standard on a societal or school level, but support or acceptance provided by the more immediate network of similarly situated friends serves as a buffer against such negative attributions. The findings suggest that programs targeting sexual behaviors should focus on how peer norms influence girls’ sexual choices. PMID:20818574

Human Endothelial Cells: Use of Heparin in Cloning and Long-Term Serial Cultivation

NASA Astrophysics Data System (ADS)

Thornton, Susan C.; Mueller, Stephen N.; Levine, Elliot M.

1983-11-01

Endothelial cells from human blood vessels were cultured in vitro, with doubling times of 17 to 21 hours for 42 to 79 population doublings. Cloned human endothelial cell strains were established for the first time and had similar proliferative capacities. This vigorous cell growth was achieved by addition of heparin to culture medium containing reduced concentrations of endothelial cell growth factor. The routine cloning and long-term culture of human endothelial cells will facilitate studying the human endothelium in vitro.

Growth analysis of pulmonary metastases from salivary gland tumors.

PubMed

Twardzik, F G; Sklaroff, D M

1976-03-01

Three cases of primary salivary gland tumors with lung metastasis are presented with extremely long survival (six, ten, and twelve years). The tumor doubling time was calculated and the growth rate of the pulmonary metastasis was found to be slow and erratic. A simplified table was devised, which permits rapid calculation of the tumor doubling time without the use of graphs. The presence of lung metastasis from some primary malignant salivary tumor is not necessarily an ominous sign: a long survival without symtoms is possible.

A new hydrodynamic analysis of double layers

NASA Technical Reports Server (NTRS)

Hora, Heinrich

1987-01-01

A genuine two-fluid model of plasmas with collisions permits the calculation of dynamic (not necessarily static) electric fields and double layers inside of plasmas including oscillations and damping. For the first time a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser-produced plasmas showing very high dynamic electric fields in nonlinear force-produced cavitous and inverted double layers in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. Results are the rotation of plasmas in magnetic fields and a new second harmonic resonance, explanation of the measured inverted double layers, explanation of the observed density-independent, second harmonics emission from laser-produced plasmas, and a laser acceleration scheme by the very high fields of the double layers.

Real-Time Tracking by Double Templates Matching Based on Timed Motion History Image with HSV Feature

PubMed Central

Li, Zhiyong; Li, Pengfei; Yu, Xiaoping; Hashem, Mervat

2014-01-01

It is a challenge to represent the target appearance model for moving object tracking under complex environment. This study presents a novel method with appearance model described by double templates based on timed motion history image with HSV color histogram feature (tMHI-HSV). The main components include offline template and online template initialization, tMHI-HSV-based candidate patches feature histograms calculation, double templates matching (DTM) for object location, and templates updating. Firstly, we initialize the target object region and calculate its HSV color histogram feature as offline template and online template. Secondly, the tMHI-HSV is used to segment the motion region and calculate these candidate object patches' color histograms to represent their appearance models. Finally, we utilize the DTM method to trace the target and update the offline template and online template real-timely. The experimental results show that the proposed method can efficiently handle the scale variation and pose change of the rigid and nonrigid objects, even in illumination change and occlusion visual environment. PMID:24592185

Monitoring of Deep Foundation Pit Support and Construction Process in Soft Soil Area of Pearl River Delta

NASA Astrophysics Data System (ADS)

Weiyi, Xie; Pengcheng

2018-03-01

The deep foundation pit supporting technology in the soft soil area of the Pearl River Delta is more complicated, and many factors influence and restrict it. In this project as an example, according to the geological conditions and the surrounding circumstances, the main foundation using bored piles and pre-stressed anchor cable supporting structure + five axis cement mixing pile curtain supporting form; partial use of double row piles supporting structure + five axis cement mixing pile curtain support type. Through the monitoring results of construction show that the foundation pit, the indicators of environmental changes are in the design range, the supporting scheme of deep foundation pit technology is feasible and reliable.

Hydrogen Generation by Koh-Ethanol Plasma Electrolysis Using Double Compartement Reactor

NASA Astrophysics Data System (ADS)

Saksono, Nelson; Sasiang, Johannes; Dewi Rosalina, Chandra; Budikania, Trisutanti

2018-03-01

This study has successfully investigated the generation of hydrogen using double compartment reactor with plasma electrolysis process. Double compartment reactor is designed to achieve high discharged voltage, high concentration, and also reduce the energy consumption. The experimental results showed the use of double compartment reactor increased the productivity ratio 90 times higher compared to Faraday electrolysis process. The highest hydrogen production obtained is 26.50 mmol/min while the energy consumption can reach up 1.71 kJ/mmol H2 at 0.01 M KOH solution. It was shown that KOH concentration, addition of ethanol, cathode depth, and temperature have important effects on hydrogen production, energy consumption, and process efficiency.

Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

NASA Technical Reports Server (NTRS)

Decker, A. J.

1984-01-01

The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three-dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed. Previously announced in STAR as N84-21849

Double-rod metasurface for mid-infrared polarization conversion

NASA Astrophysics Data System (ADS)

Pu, Yang; Luo, Yi; Liu, Lu; He, De; Xu, Hongyan; Jing, Hongwei; Jiang, Yadong; Liu, Zhijun

2018-02-01

Not Available Project supported by the National Natural Science Foundation of China (Grants Nos. 61421002 and 61575036), the Chinese National 1000 Plan for Young Talents, and the Startup Funding from University of Electronic Science and Technology of China.

Laboratory observation of multiple double layer resembling space plasma double layer

NASA Astrophysics Data System (ADS)

Alex, Prince; Arumugam, Saravanan; Sinha, Suraj

2017-10-01

Perceptible double layer consisting of more than one layers were produced in laboratory using a double discharge plasma setup. The confinement of oppositely charged particles in each layer with sharply defined luminous boarder is attributed to the self-organization scenario. This structure is generated in front of a positively biased electrode when the electron drift velocity (νd) exceeds 1.3 times the electron thermal velocity (νte) . Stable multiple double layer structures were observed only between 1.3 νte <=νd <= 3 νte. At νd = 1.3 νte, oscillations were excited in the form of large amplitude burst followed by a high frequency stable oscillation. Beyond νd = 3 νte, multiple double layer begins to collapse which is characterized by an emergence in turbulence. Long range dependence in the corresponding electrostatic potential fluctuations indicates the role of self-organized criticality in the emergence of turbulence. The algebraic decaying tale of the autocorrelation function and power law behavior in the power spectrum are consistent with the observation.

The double helium-white dwarf channel for the formation of AM CVn binaries

NASA Astrophysics Data System (ADS)

Zhang, Xian-Fei; Liu, Jin-Zhong; Jeffery, C. Simon; Hall, Philip D.; Bi, Shao-Lan

2018-01-01

Most close double helium white dwarfs will merge within a Hubble time due to orbital decay by gravitational wave radiation. However, a significant fraction with low mass ratios will survive for a long time as a consequence of stable mass transfer. Such stable mass transfer between two helium white dwarfs (HeWDs) provides one channel for the production of AM CVn binary stars. In previous calculations of double HeWD progenitors, the accreting HeWD was treated as a point mass. We have computed the evolution of 16 double HeWD models in order to investigate the consequences of treating the evolution of both components in detail. We find that the boundary between binaries having stable and unstable mass transfer is slightly modified by this approach. By comparing with observed periods and mass ratios, we redetermine masses of eight known AM CVn stars by our double HeWDs channel, i.e. HM Cnc, AM CVn, V406 Hya, J0926, J1240, GP Com, Gaia14aae and V396 Hya.We propose that central spikes in the triple-peaked emission spectra of J1240, GP Com and V396 Hya and the surface abundance ratios of N/C/O in GP Com can be explained by the stable double HeWD channel. The mass estimates derived from our calculations are used to discuss the predicted gravitational wave signal in the context of the Laser Interferometer Space Antenna (LISA) project.