Size distributions of aerosol and water-soluble ions in Nanjing during a crop residual burning event.

PubMed

Wang, Honglei; Zhu, Bin; Shen, Lijuan; Kang, Hanqing

2012-01-01

To investigate the impact on urban air pollution by crop residual burning outside Nanjing, aerosol concentration, pollution gas concentration, mass concentration, and water-soluble ion size distribution were observed during one event of November 4-9, 2010. Results show that the size distribution of aerosol concentration is bimodal on pollution days and normal days, with peak values at 60-70 and 200-300 nm, respectively. Aerosol concentration is 10(4) cm(-3) x nm(-1) on pollution days. The peak value of spectrum distribution of aerosol concentration on pollution days is 1.5-3.3 times higher than that on a normal day. Crop residual burning has a great impact on the concentration of fine particles. Diurnal variation of aerosol concentration is trimodal on pollution days and normal days, with peak values at 03:00, 09:00 and 19:00 local standard time. The first peak is impacted by meteorological elements, while the second and third peaks are due to human activities, such as rush hour traffic. Crop residual burning has the greatest impact on SO2 concentration, followed by NO2, O3 is hardly affected. The impact of crop residual burning on fine particles (< 2.1 microm) is larger than on coarse particles (> 2.1 microm), thus ion concentration in fine particles is higher than that in coarse particles. Crop residual burning leads to similar increase in all ion components, thus it has a small impact on the water-soluble ions order. Crop residual burning has a strong impact on the size distribution of K+, Cl-, Na+, and F- and has a weak impact on the size distributions of NH4+, Ca2+, NO3- and SO4(2-).

A preliminary report on the measurements of forest canopies with C-band radar scatterometer at NASA/NSTL

NASA Technical Reports Server (NTRS)

Wu, S. T.

1985-01-01

This paper presents preliminary results of C-band radar scatterometer measurements of forest canopies of southeastern forests in the vicinity of NASA/NSTL. The results are as follows: (1) the radar backscattering coefficients (BSC) of deciduous forests such as oak, maple, blackgum, and cypress are higher than those of coniferous forests such as slash pine plantation and natural pine; (2) at a large incidence angle, where polarization effect is significant, and by ranging measurement, the VV polarization BSC obtain peak value at the first few meters from the canopy top and decrease rather quickly, while the HH polarization BSC obtain peak value at longer distances from the canopy top and decrease rather slowly through the canopy; and (3) using the active radar calibrator for tree canopy attenuation measurement of a dense and a sparse live oak, it is found that the tree canopies with higher attenuations have higher BSC for all three polarizations, with VV polarization containing the largest differential (2.2 dB).

Gyrokinetic modeling of impurity peaking in JET H-mode plasmas

NASA Astrophysics Data System (ADS)

Manas, P.; Camenen, Y.; Benkadda, S.; Weisen, H.; Angioni, C.; Casson, F. J.; Giroud, C.; Gelfusa, M.; Maslov, M.

2017-06-01

Quantitative comparisons are presented between gyrokinetic simulations and experimental values of the carbon impurity peaking factor in a database of JET H-modes during the carbon wall era. These plasmas feature strong NBI heating and hence high values of toroidal rotation and corresponding gradient. Furthermore, the carbon profiles present particularly interesting shapes for fusion devices, i.e., hollow in the core and peaked near the edge. Dependencies of the experimental carbon peaking factor ( R / L nC ) on plasma parameters are investigated via multilinear regressions. A marked correlation between R / L nC and the normalised toroidal rotation gradient is observed in the core, which suggests an important role of the rotation in establishing hollow carbon profiles. The carbon peaking factor is then computed with the gyrokinetic code GKW, using a quasi-linear approach, supported by a few non-linear simulations. The comparison of the quasi-linear predictions to the experimental values at mid-radius reveals two main regimes. At low normalised collisionality, ν * , and T e / T i < 1 , the gyrokinetic simulations quantitatively recover experimental carbon density profiles, provided that rotodiffusion is taken into account. In contrast, at higher ν * and T e / T i > 1 , the very hollow experimental carbon density profiles are never predicted by the simulations and the carbon density peaking is systematically over estimated. This points to a possible missing ingredient in this regime.

Modelling dental implant extraction by pullout and torque procedures.

PubMed

Rittel, D; Dorogoy, A; Shemtov-Yona, K

2017-07-01

Dental implants extraction, achieved either by applying torque or pullout force, is used to estimate the bone-implant interfacial strength. A detailed description of the mechanical and physical aspects of the extraction process in the literature is still missing. This paper presents 3D nonlinear dynamic finite element simulations of a commercial implant extraction process from the mandible bone. Emphasis is put on the typical load-displacement and torque-angle relationships for various types of cortical and trabecular bone strengths. The simulations also study of the influence of the osseointegration level on those relationships. This is done by simulating implant extraction right after insertion when interfacial frictional contact exists between the implant and bone, and long after insertion, assuming that the implant is fully bonded to the bone. The model does not include a separate representation and model of the interfacial layer for which available data is limited. The obtained relationships show that the higher the strength of the trabecular bone the higher the peak extraction force, while for application of torque, it is the cortical bone which might dictate the peak torque value. Information on the relative strength contrast of the cortical and trabecular components, as well as the progressive nature of the damage evolution, can be revealed from the obtained relations. It is shown that full osseointegration might multiply the peak and average load values by a factor 3-12 although the calculated work of extraction varies only by a factor of 1.5. From a quantitative point of view, it is suggested that, as an alternative to reporting peak load or torque values, an average value derived from the extraction work be used to better characterize the bone-implant interfacial strength. Copyright © 2017 Elsevier Ltd. All rights reserved.

Histopathologic diversity of gastric cancers: Relationship between enhancement pattern on dynamic contrast-enhanced CT and histological type.

PubMed

Tsurumaru, Daisuke; Miyasaka, Mitsutoshi; Muraki, Toshio; Nishie, Akihiro; Asayama, Yoshiki; Oki, Eiji; Oda, Yoshinao; Honda, Hiroshi

2017-12-01

To evaluate the diagnostic value of contrast-enhanced computed tomography gastrography (CE-CTG) to predict the histological type of gastric cancer. We analyzed 47 consecutive patients with resectable advanced gastric cancer preoperatively evaluated by multiphasic dynamic contrast-enhanced CT. Two radiologists independently reviewed the CT images and they determined the peak enhancement phase, and then measured the CT attenuation value of the gastric lesion for each phase. The histological types of gastric cancers were assigned to three groups as differentiated-type, undifferentiated-type, and mixed-type. We compared the peak enhancement phase of the three types and compared the CT attenuation values in each phase. The peak enhancement was significantly different between the three types of gastric cancers for both readers (reader 1, p=0.001; reader 2, p=0.009); most of the undifferentiated types had peak enhancement in the delayed phase. The CT attenuation values of undifferentiated type were significantly higher than those of differentiated or mixed type in the delayed phase according to both readers (reader 1, p=0.002; reader 2, p=0.004). CE-CTG could provide helpful information in diagnosing the histological type of gastric cancers preoperatively. Copyright © 2017 Elsevier B.V. All rights reserved.

Micro- and Nanomechanical Analysis of Articular Cartilage by Indentation-Type Atomic Force Microscopy: Validation with a Gel-Microfiber Composite

PubMed Central

Loparic, Marko; Wirz, Dieter; Daniels, A.U.; Raiteri, Roberto; VanLandingham, Mark R.; Guex, Geraldine; Martin, Ivan; Aebi, Ueli; Stolz, Martin

2010-01-01

Abstract As documented previously, articular cartilage exhibits a scale-dependent dynamic stiffness when probed by indentation-type atomic force microscopy (IT-AFM). In this study, a micrometer-size spherical tip revealed an unimodal stiffness distribution (which we refer to as microstiffness), whereas probing articular cartilage with a nanometer-size pyramidal tip resulted in a bimodal nanostiffness distribution. We concluded that indentation of the cartilage's soft proteoglycan (PG) gel gave rise to the lower nanostiffness peak, whereas deformation of its collagen fibrils yielded the higher nanostiffness peak. To test our hypothesis, we produced a gel-microfiber composite consisting of a chondroitin sulfate-containing agarose gel and a fibrillar poly(ethylene glycol)-terephthalate/poly(butylene)-terephthalate block copolymer. In striking analogy to articular cartilage, the microstiffness distribution of the synthetic composite was unimodal, whereas its nanostiffness exhibited a bimodal distribution. Also, similar to the case with cartilage, addition of the negatively charged chondroitin sulfate rendered the gel-microfiber composite's water content responsive to salt. When the ionic strength of the surrounding buffer solution increased from 0.15 to 2 M NaCl, the cartilage's microstiffness increased by 21%, whereas that of the synthetic biomaterial went up by 31%. When the nanostiffness was measured after the ionic strength was raised by the same amount, the cartilage's lower peak increased by 28%, whereas that of the synthetic biomaterial went up by 34%. Of interest, the higher peak values remained unchanged for both materials. Taken together, these results demonstrate that the nanoscale lower peak is a measure of the soft PG gel, and the nanoscale higher peak measures collagen fibril stiffness. In contrast, the micrometer-scale measurements fail to resolve separate stiffness values for the PG and collagen fibril moieties. Therefore, we propose to use nanostiffness as a new biomarker to analyze structure-function relationships in normal, diseased, and engineered cartilage. PMID:20513418

Incremental exercise test for the evaluation of peak oxygen consumption in paralympic swimmers.

PubMed

de Souza, Helton; DA Silva Alves, Eduardo; Ortega, Luciana; Silva, Andressa; Esteves, Andrea M; Schwingel, Paulo A; Vital, Roberto; DA Rocha, Edilson A; Rodrigues, Bruno; Lira, Fabio S; Tufik, Sergio; DE Mello, Marco T

2016-04-01

Peak oxygen consumption (VO2peak) is a fundamental parameter used to evaluate physical capacity. The objective of this study was to explore two types of incremental exercise tests used to determine VO2peak in four Paralympic swimmers: arm ergometer testing in the laboratory and testing in the swimming pool. On two different days, the VO2peak values of the four athletes were measured in a swimming pool and by a cycle ergometer. The protocols identified the VO2peak by progressive loading until the volitional exhaustion maximum was reached. The results were analyzed using the paired Student's t-test, Cohen's d effect sizes and a linear regression. The results showed that the VO2peak values obtained using the swimming pool protocol were higher (P=0.02) than those obtained by the arm ergometer (45.8±19.2 vs. 30.4±15.5; P=0.02), with a large effect size (d=3.20). When analyzing swimmers 1, 2, 3 and 4 individually, differences of 22.4%, 33.8%, 60.1% and 27.1% were observed, respectively. Field tests similar to the competitive setting are a more accurate way to determine the aerobic capacity of Paralympic swimmers. This approach provides more sensitive data that enable better direction of training, consequently facilitating improved performance.

Initial Circulation and Peak Vorticity Behavior of Vortices Shed from Airfoil Vortex Generators

NASA Technical Reports Server (NTRS)

Wendt, Bruce J.; Biesiadny, Tom (Technical Monitor)

2001-01-01

An extensive parametric study of vortices shed from airfoil vortex generators has been conducted to determine the dependence of initial vortex circulation and peak vorticity on elements of the airfoil geometry and impinging flow conditions. These elements include the airfoil angle of attack, chord length, span, aspect ratio, local boundary layer thickness, and free stream Mach number. In addition, the influence of airfoil-to-airfoil spacing on the circulation and peak vorticity has been examined for pairs of co-rotating and counter-rotating vortices. The vortex generators were symmetric airfoils having a NACA-0012 cross-sectional profile. These airfoils were mounted either in isolation, or in pairs, on the surface of a straight pipe. The turbulent boundary layer thickness to pipe radius ratio was about 17 percent. The circulation and peak vorticity data were derived from cross-plane velocity measurements acquired with a seven-hole probe at one chord-length downstream of the airfoil trailing edge location. The circulation is observed to be proportional to the free-stream Mach number, the angle-of-attack, and the span-to-boundary layer thickness ratio. With these parameters held constant, the circulation is observed to fall off in monotonic fashion with increasing airfoil aspect ratio. The peak vorticity is also observed to be proportional to the free-stream Mach number, the airfoil angle-of-attack, and the span-to-boundary layer thickness ratio. Unlike circulation, however, the peak vorticity is observed to increase with increasing aspect ratio, reaching a peak value at an aspect ratio of about 2.0 before falling off again at higher values of aspect ratio. Co-rotating vortices shed from closely spaced pairs of airfoils have values of circulation and peak vorticity under those values found for vortices shed from isolated airfoils of the same geometry. Conversely, counter-rotating vortices show enhanced values of circulation and peak vorticity when compared to values obtained in isolation. The circulation may be accurately modeled with an expression based on Prandtl's relationship between finite airfoil circulation and airfoil geometry. A correlation for the peak vorticity has been derived from a conservation relationship equating the moment at the airfoil tip to the rate of angular momentum production of the shed vortex, modeled as a Lamb (ideal viscous) vortex. This technique provides excellent qualitative agreement to the observed behavior of peak vorticity for low aspect ratio airfoils typically used as vortex generators.

Bond strength of etch-and-rinse and self-etch adhesive systems to enamel and dentin irradiated with a novel CO2 9.3 μm short-pulsed laser for dental restorative procedures.

PubMed

Rechmann, Peter; Bartolome, N; Kinsel, R; Vaderhobli, R; Rechmann, B M T

2017-12-01

The objective of this study was to evaluate the influence of CO 2 9.3 μm short-pulsed laser irradiation on the shear bond strength of composite resin to enamel and dentin. Two hundred enamel and 210 dentin samples were irradiated with a 9.3 µm carbon dioxide laser (Solea, Convergent Dental, Inc., Natick, MA) with energies which either enhanced caries resistance or were effective for ablation. OptiBond Solo Plus [OptiBondTE] (Kerr Corporation, Orange, CA) and Peak Universal Bond light-cured adhesive [PeakTE] (Ultradent Products, South Jordan, UT) were used. In addition, Scotchbond Universal [ScotchbondSE] (3M ESPE, St. Paul, MN) and Peak SE self-etching primer with Peak Universal Bond light-cured adhesive [PeakSE] (Ultradent Products) were tested. Clearfil APX (Kuraray, New York, NY) was bonded to the samples. After 24 h, a single plane shear bond test was performed. Using the caries preventive setting on enamel resulted in increased shear bond strength for all bonding agents except for self-etch PeakSE. The highest overall bond strength was seen with PeakTE (41.29 ± 6.04 MPa). Etch-and-rinse systems achieved higher bond strength values to ablated enamel than the self-etch systems did. PeakTE showed the highest shear bond strength with 35.22 ± 4.40 MPa. OptiBondTE reached 93.8% of its control value. The self-etch system PeakSE presented significantly lower bond strength. The shear bond strength to dentin ranged between 19.15 ± 3.49 MPa for OptiBondTE and 43.94 ± 6.47 MPa for PeakSE. Etch-and-rinse systems had consistently higher bond strength to CO 2 9.3 µm laser-ablated enamel. Using the maximum recommended energy for dentin ablation, the self-etch system PeakSE reached the highest bond strength (43.9 ± 6.5 MPa).

Unusual Physical Properties of the Chicxulub Crater Peak Ring: Results from IODP/ICDP Expedition 364

NASA Astrophysics Data System (ADS)

Christeson, G. L.; Gebhardt, C.; Gulick, S. P. S.; Le Ber, E.; Lofi, J.; Morgan, J. V.; Nixon, C.; Rae, A.; Schmitt, D. R.

2017-12-01

IODP/ICDP Expedition 364 Hole M0077A drilled into the peak ring of the Chicxulub impact crater, recovering core between 505.7 and 1334.7 m below the seafloor (mbsf). Physical property measurements include wireline logging data, a vertical seismic profile (VSP), Multi-Sensor Core Logger (MSCL) measurements, and discrete sample measurements. The Hole M0077A peak ring rocks have unusual physical properties. Across the boundary between post-impact sediment and crater breccia we measure a sharp decrease in velocities and densities, and an increase in porosity. Mean crater breccia values are 3000-3300 m/s, 2.14-2.15 g/cm3, and 31% for velocity, density, and porosity, respectively. This zone is also associated with a low-frequency reflector package on MCS profiles and a low-velocity layer in FWI images, both confirmed from the VSP dataset. The thin (24 m) crater melt unit has mean velocity measurements of 3800-4150 m/s, density measurements of 2.32-2.34 g/cm3, and porosity measurements of 20%; density and porosity values are intermediate between the overlying impact breccia and underlying granitic basement, while the velocity values are similar to those for the underlying basement. The Hole M0077A crater melt unit velocities and densities are considerably less than values of 5800 m/s and 2.68 g/cm3 measured at an onshore well located in the annular trough. The uplifted granitic peak ring materials have mean values of 4100-4200 m/s, 2.39-2.44 g/cm3, and 11% for compressional wave velocity, density, and porosity, respectively; these values differ significantly from typical granite which has higher velocities (5400-6000 m/s) and densities (2.62-2.67 g/cm3), and lower porosities (<1%). All Hole M0077A peak-ring velocity, density, and porosity measurements indicate considerable fracturing, and are consistent with numerical models for peak-ring formation.

Kinematic measurements of the vocal-fold displacement waveform in typical children and adult populations: quantification of high-speed endoscopic videos.

PubMed

Patel, Rita; Donohue, Kevin D; Unnikrishnan, Harikrishnan; Kryscio, Richard J

2015-04-01

This article presents a quantitative method for assessing instantaneous and average lateral vocal-fold motion from high-speed digital imaging, with a focus on developmental changes in vocal-fold kinematics during childhood. Vocal-fold vibrations were analyzed for 28 children (aged 5-11 years) and 28 adults (aged 21-45 years) without voice disorders. The following kinematic features were analyzed from the vocal-fold displacement waveforms: relative velocity-based features (normalized average and peak opening and closing velocities), relative acceleration-based features (normalized peak opening and closing accelerations), speed quotient, and normalized peak displacement. Children exhibited significantly larger normalized peak displacements, normalized average and peak opening velocities, normalized average and peak closing velocities, peak opening and closing accelerations, and speed quotient compared to adult women. Values of normalized average closing velocity and speed quotient were higher in children compared to adult men. When compared to adult men, developing children typically have higher estimates of kinematic features related to normalized displacement and its derivatives. In most cases, the kinematic features of children are closer to those of adult men than adult women. Even though boys experience greater changes in glottal length and pitch as they mature, results indicate that girls experience greater changes in kinematic features compared to boys.

Comparison of abdominal muscle activity and peak expiratory flow between forced vital capacity and fast expiration exercise.

PubMed

Ishida, Hiroshi; Suehiro, Tadanobu; Watanabe, Susumu

2017-04-01

[Purpose] The purpose of this investigation was to compare the activities of the abdominal muscles and peak expiratory flow between forced vital capacity and fast expiration exercise. [Subjects and Methods] Fifteen healthy male participated in this study. Peak expiratory flow and electromyographic activities of the rectus abdominis, external oblique, and internal oblique/transversus abdominis muscles were measured during forced vital capacity and fast expiration exercise and then peak amplitude and its appearance time were obtained. [Results] Peak expiratory flow values were significantly higher during fast expiration exercise than during forced vital capacity. The internal oblique/transversus abdominis muscles showed significantly higher peak amplitude during fast expiration exercise than during forced vital capacity. However, there were no significant differences between forced vital capacity and fast expiration exercise in the rectus abdominis and external oblique muscles. There was no difference in the appearance time of the peak amplitude between forced vital capacity and fast expiration exercise in any muscle. [Conclusion] Fast expiration exercise might be beneficial for increasing expiratory speed and neuromuscular activation of the internal oblique/transversus abdominis muscles compared to forced vital capacity. These findings could be considered when recommending a variation of expiratory muscle strength training as part of pulmonary rehabilitation programs.

Biomechanical evaluation of one-piece and two-piece small-diameter dental implants: In-vitro experimental and three-dimensional finite element analyses.

PubMed

Wu, Aaron Yu-Jen; Hsu, Jui-Ting; Chee, Winston; Lin, Yun-Te; Fuh, Lih-Jyh; Huang, Heng-Li

2016-09-01

Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants. Copyright © 2016. Published by Elsevier B.V.

Scaling the flood regime with the soil hydraulic properties of the catchment

NASA Astrophysics Data System (ADS)

Peña Rojas, Luis Eduardo; Francés García, Félix; Barrios Peña, Miguel

2015-04-01

The spatial land cover distribution and soil type affect the hydraulic properties of soils, facilitating or retarding the infiltration rate and the response of a catchment during flooding events. This research analyzes: 1) the effect of land cover use in different time periods as a source of annual maximum flood records nonstationarity; 2) the scalability of the relationship between soil hydraulic properties of the catchment (initial abstractions, upper soil capillary storage and vertical and horizontal hydraulic conductivity) and the flood regime. The study was conducted in Combeima River basin in Colombia - South America and it was modelled the changes in the land uses registered in 1991, 2000, 2002 and 2007, using distributed hydrological modelling and nonparametric tests. The results showed that changes in land use affect hydraulic properties of soil and it has influence on the magnitude of flood peaks. What is a new finding is that this behavior is scalable with the soil hydraulic properties of the catchment flood moments have a simple scaling behavior and the peaks flow increases with higher values of capillary soil storage, whereas higher values, the peaks decreased. Finally it was applied Generalized Extreme Values and it was found scalable behavior in the parameters of the probability distribution function. The results allowed us to find a relationship between soil hydraulic properties and the behavior of flood regime in the basin studied.

On the Origin of a Maximum Peak Pressure on the Target Outside of the Stagnation Point upon Normal Impact of a Blunt Projectile and with Underwater Explosion

NASA Astrophysics Data System (ADS)

Gonor, Alexander; Hooton, Irene

2006-07-01

Impact of a rigid projectile (impactor), against a metal target and a condensed explosive surface considered as the important process accompanying the normal entry of a rigid projectile into a target, was overlooked in the preceding studies. Within the framework of accurate shock wave theory, the flow-field, behind the shock wave attached to the perimeter of the adjoined surface, was defined. An important result is the peak pressure rises at points along the target surface away from the stagnation point. The maximum values of the peak pressure are 2.2 to 3.2 times higher for the metallic and soft targets (nitromethane, PBX 9502), than peak pressure values at the stagnation point. This effect changes the commonly held notion that the maximum peak pressure is reached at the projectile stagnation point. In the present study the interaction of a spherical decaying blast wave, caused by an underwater explosion, with a piece-wise plane target, having corner configurations, is investigated. The numerical calculation results in the determination of the vulnerable spots on the target, where the maximum peak overpressure surpassed that for the head-on shock wave reflection by a factor of 4.

Photoelectric return-stroke velocity and peak current estimates in natural and triggered lightning

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Rust, W. David

1989-01-01

Two-dimensional photoelectric return stroke velocities from 130 strokes are presented, including 86 negative natural, 41 negative triggered, one positive triggered, and two positive natural return strokes. For strokes starting near the ground and exceeding 500 m in length, the average velocity is 1.3 + or - 0.3 X 10 to the 8th m/s for natural return strokes and 1.2 + or - 0.3 X 10 to the 8th m/s for triggered return strokes. For strokes with lengths less than 500 m, the average velocities are slightly higher. Using the transmission line model (TLM), the shortest segment one-dimensional return stroke velocity, and either the maximum or plateau electric field, it is shown that natural strokes have a peak current distribution that is lognormal with a median value of 16 kA (maximum E) or 12 kA (plateau E). Triggered lightning has a medium peak current value of 21 kA (maximum E) or 15 kA (plateau E). Correlations are found between TLM peak currents and velocities for triggered and natural subsequent return strokes, but not between TLM peak currents and natural first return stroke velocities.

Within-session responses to high-intensity interval training in spinal cord injury.

PubMed

Astorino, Todd Anthony; Thum, Jacob S

2018-02-01

Completion of high-intensity interval training (HIIT) increases maximal oxygen uptake and health status, yet its feasibility in persons with spinal cord injury is unknown. To compare changes in cardiorespiratory and metabolic variables between two interval training regimes and moderate intensity exercise. Nine adults with spinal cord injury (duration = 6.8 ± 6.2 year) initially underwent determination of peak oxygen uptake. During subsequent sessions, they completed moderate intensity exercise, HIIT, or sprint interval training. Oxygen uptake, heart rate, and blood lactate concentration were measured. Oxygen uptake and heart rate increased (p < 0.05) during both interval training sessions and were similar (p > 0.05) to moderate intensity exercise. Peak oxygen uptake and heart rate were higher (p < 0.05) with HIIT (90% peak oxygen uptake and 99% peak heart rate) and sprint interval training (80% peak oxygen uptake and 96% peak heart rate) versus moderate intensity exercise. Despite a higher intensity and peak cardiorespiratory strain, all participants preferred interval training versus moderate exercise. Examining long-term efficacy and feasibility of interval training in this population is merited, considering that exercise intensity is recognized as the most important variable factor of exercise programming to optimize maximal oxygen uptake. Implications for Rehabilitation Spinal cord injury (SCI) reduces locomotion which impairs voluntary physical activity, typically resulting in a reduction in peak oxygen uptake and enhanced chronic disease risk. In various able-bodied populations, completion of high-intensity interval training (HIIT) has been consistently reported to improve cardiorespiratory fitness and other health-related outcomes, although its efficacy in persons with SCI is poorly understood. Data from this study in 9 men and women with SCI show similar changes in oxygen uptake and heart in response to HIIT compared to a prolonged bout of aerobic exercise, although peak values were higher in response to HIIT. Due to the higher peak metabolic strain induced by HIIT as well as universal preference for this modality versus aerobic exercise as reported in this study, further work testing utility of HIIT in this population is merited.

Determination of antioxidant activity of spices and their active principles by differential pulse voltammetry.

PubMed

Palma, Alberto; Ruiz Montoya, Mercedes; Arteaga, Jesús F; Rodríguez Mellado, Jose M

2014-01-22

The anodic oxidation of mercury in the presence of hydrogen peroxide in differential pulse voltammetry (DPV) was used to determine the antioxidant (AO) character of radical scavengers. Hydroperoxide radical is formed at the potentials of the oxidation peak on mercury electrodes, such radical reacting with the antioxidants in different extension. The parameter C10 (antioxidant concentration at which the peak area decreases by 10%) is used to measure the scavenging activity of the individual antioxidants. To establish the scavenging activity of antioxidant mixtures as a whole, the parameter, μ10 as the reverse of V10, V10 being the volume necessary to decrease the peak area in DPV by 10%, was selected. Higher μ10 values correspond to higher scavenging activity. The studies have been extended to aqueous extracts of some species. The results may be useful in explaining the effect of spices in vitro and in vivo studies.

Electro-Chemical-Mechanical, Low Stress, Automatic Polishing (ECMP) Device (Preprint)

DTIC Science & Technology

2010-01-01

into models that predict mechanical response [ 4 - 6 ]. In addition, surface preparation steps are critical to the imaging of ceramic and hybrid...2p 3/2 peak in the spectral data found in Figure 4 . The Ti 2p 3/2 peak is initially observed at 458.4 eV indicating that titanium is present in its...above 6 acceptable limits for both (average IQ values were higher than 2000). For the titanium samples, the samples processed without applied

Site response assessment at the city of Alkhobar, Eastern Saudi Arabia from microtremor and boring data

NASA Astrophysics Data System (ADS)

Fnais, M. S.

2014-12-01

The AlKhobar City affected by distant earthquakes from Zagros fold-fault belt of subduction zone. These earthquakes produced great site effects on the sedimentary layers that in turn significantly influenced earthquake ground motions in the area. Mapping of site response using microtremor measurements compared with geological and borehole data of Alkhobar city is the main target of this work. The resonance frequency and their H/V values have been calculated using Nakamura technique through deployed of seismograph instruments at 113 sites in AlKhobar city for different time periods. The recording length was about one hour with sampling frequency of 100 Hz. Most of the measured sites present three peaks for the resonance frequency; the first peak ranges from 0.33 to 1.03 Hz, the second peak ranges from 1.03 to 1.23 Hz, while the third peak ranges from 1.23-1.73. Tests have been conducted to ensure that these peaks are natural in origin. The northern zones of AlKhobar City have lower values of resonance frequency indicating great thickness of sediments. In contrast, the southern parts of the city have higher values of resonance frequency illustrating shallow depths of the bedrock. Furthermore, twenty of boreholes have been conducted through AlKhobar City to different depth. Standard penetration test (SPT) data has been corrected and used to calculate the resonance frequency at their locations. Borehole results clarified that the resonance frequency values range from 0.27 to 1.95 Hz. These results are correlated well with that of the microtremor measurements. Accordingly, the first peak have been interpreted due to the impedance contrast between the limestone and the overlying sediments, while the third peak is originated from a boundary between the upper most surface layer and the underlying sediments. These results must be applied for earthquake risk mitigation in AlKhobar City.

Sensitivity of peak flow to the change of rainfall temporal pattern due to warmer climate

NASA Astrophysics Data System (ADS)

Fadhel, Sherien; Rico-Ramirez, Miguel Angel; Han, Dawei

2018-05-01

The widely used design storms in urban drainage networks has different drawbacks. One of them is that the shape of the rainfall temporal pattern is fixed regardless of climate change. However, previous studies have shown that the temporal pattern may scale with temperature due to climate change, which consequently affects peak flow. Thus, in addition to the scaling of the rainfall volume, the scaling relationship for the rainfall temporal pattern with temperature needs to be investigated by deriving the scaling values for each fraction within storm events, which is lacking in many parts of the world including the UK. Therefore, this study analysed rainfall data from 28 gauges close to the study area with a 15-min resolution as well as the daily temperature data. It was found that, at warmer temperatures, the rainfall temporal pattern becomes less uniform, with more intensive peak rainfall during higher intensive times and weaker rainfall during less intensive times. This is the case for storms with and without seasonal separations. In addition, the scaling values for both the rainfall volume and the rainfall fractions (i.e. each segment of rainfall temporal pattern) for the summer season were found to be higher than the corresponding results for the winter season. Applying the derived scaling values for the temporal pattern of the summer season in a hydrodynamic sewer network model produced high percentage change of peak flow between the current and future climate. This study on the scaling of rainfall fractions is the first in the UK, and its findings are of importance to modellers and designers of sewer systems because it can provide more robust scenarios for flooding mitigation in urban areas.

Maximum shortening velocity of lymphatic muscle approaches that of striated muscle.

PubMed

Zhang, Rongzhen; Taucer, Anne I; Gashev, Anatoliy A; Muthuchamy, Mariappan; Zawieja, David C; Davis, Michael J

2013-11-15

Lymphatic muscle (LM) is widely considered to be a type of vascular smooth muscle, even though LM cells uniquely express contractile proteins from both smooth muscle and cardiac muscle. We tested the hypothesis that LM exhibits an unloaded maximum shortening velocity (Vmax) intermediate between that of smooth muscle and cardiac muscle. Single lymphatic vessels were dissected from the rat mesentery, mounted in a servo-controlled wire myograph, and subjected to isotonic quick release protocols during spontaneous or agonist-evoked contractions. After maximal activation, isotonic quick releases were performed at both the peak and plateau phases of contraction. Vmax was 0.48 ± 0.04 lengths (L)/s at the peak: 2.3 times higher than that of mesenteric arteries and 11.4 times higher than mesenteric veins. In cannulated, pressurized lymphatic vessels, shortening velocity was determined from the maximal rate of constriction [rate of change in internal diameter (-dD/dt)] during spontaneous contractions at optimal preload and minimal afterload; peak -dD/dt exceeded that obtained during any of the isotonic quick release protocols (2.14 ± 0.30 L/s). Peak -dD/dt declined with pressure elevation or activation using substance P. Thus, isotonic methods yielded Vmax values for LM in the mid to high end (0.48 L/s) of those the recorded for phasic smooth muscle (0.05-0.5 L/s), whereas isobaric measurements yielded values (>2.0 L/s) that overlapped the midrange of values for cardiac muscle (0.6-3.3 L/s). Our results challenge the dogma that LM is classical vascular smooth muscle, and its unusually high Vmax is consistent with the expression of cardiac muscle contractile proteins in the lymphatic vessel wall.

Normative reference values for the 20 m shuttle‐run test in a population‐based sample of school‐aged youth in Bogota, Colombia: the FUPRECOL study

PubMed Central

Palacios‐López, Adalberto; Humberto Prieto‐Benavides, Daniel; Enrique Correa‐Bautista, Jorge; Izquierdo, Mikel; Alonso‐Martínez, Alicia; Lobelo, Felipe

2016-01-01

Abstract Objectives Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio‐metabolic risk. Methods A total of 7244 children and adolescents attending public schools in Bogota, Colombia (55.7% girls; age range of 9–17.9 years) participated in this study. We expressed CRF performance as the nearest stage (minute) completed and the estimated peak oxygen consumption (V˙O2peak). Smoothed percentile curves were calculated. In addition, we present the prevalence of low CRF after applying a correction factor to account for the impact of Bogota's altitude (2625 m over sea level) on CRF assessment, and we calculated the number of participants who fell below health‐related FITNESSGRAM cut‐points for low CRF. Results Shuttles and V˙O2peak were higher in boys than in girls in all age groups. In boys, there were higher levels of performance with increasing age, with most gains between the ages of 13 and 17. The proportion of subjects with a low CRF, suggestive of future cardio‐metabolic risk (health risk FITNESSGRAM category) was 31.5% (28.2% for boys and 34.1% for girls; X2 P = .001). After applying a 1.11 altitude correction factor, the overall prevalence of low CRF was 11.5% (9.6% for boys and 13.1% for girls; X2 P = .001). Conclusions Our results provide sex‐ and age‐specific normative reference standards for the 20 m shuttle‐run test and estimated V˙O2peak values in a large, population‐based sample of schoolchildren from a large Latin‐American city at high altitude. PMID:27500986

[Diagnostic value of serum procalcitonin for infection in the immunocompromised critically ill patients with suspected infection].

PubMed

Yu, Xin; Ma, Xinhua; Ai, Yuhang

2015-06-01

To evaluate the diagnostic and prognostic value of the serum procalcitonin (PCT) level in the non-acquired immune deficiency syndrome (AIDS) immunocompromised critically ill patients suspected to have infection. A retrospective study was conducted in the non-AIDS immunocompromised patients who were admitted to Department of Critical Care Medicine of Xiangya Hospital, Central South University during January 2011 to December 2014. Demographic characteristics, underlying disease, acute physiology and chronic health evaluation II (APACHEII) score at admission, and clinical records including baseline and peak levels of temperature, white blood count (WBC), PCT, and survival rate within 28 days, infection focus, infectious agents (bacterial, fungi or mixed infection), and the severity of infection (sepsis, severe sepsis, or septic shock) were recorded. Receiver operating characteristic (ROC) curve was plotted, and the diagnostic and protective value of above parameters was evaluated. A total of 98 patients (43 male and 55 female) were enrolled in the study with a median age of 44 (28, 52) years old and a median APACHEII score of 17 (11, 20); 47 with malignant hematological tumor, 45 with autoimmune diseases, and 6 post solid organ transplantation. Among them 53 patients (54.1%) died within 28 days. Twenty-seven patients were diagnosed as systemic inflammatory response syndrome (SIRS) without infection. Among 71 patients with infection, 45 were diagnosed as bacterial infection, 10 with fungal infection, and 16 with mixed infection. Sepsis was diagnosed in 7 patients, severe sepsis in 32 patients, and septic shock in 32 patients. (1) There was no statistical significance in the baseline and peak levels of PCT and WBC, or baseline level of temperature between the groups of SIRS patients without infection and infected patients. The peak level of temperature was significantly higher in the patients with infection as compared with that of the SIRS without infection patients [centigrade: 39.4 (38.9, 40.0) vs. 38.8 (37.8, 39.2), Z=-3.268, P=0.001]. It was showed by subgroup analysis that in patients with hematological malignant disease or autoimmune diseases, higher level of body temperature was found in infection group compared with non-infection SIRS group [centigrade: 39.5 (39.0, 40.0) vs. 39.0 (38.4, 39.4), Z=-2.349, P=0.019; 39.0 (38.4, 39.5) vs. 38.2 (37.0, 38.9), Z=-2.221, P=0.026]. (2) The baseline level of PCT (μg/L) were 0.54 (0.20, 4.19), 2.78 (0.50, 9.54), 1.00 (0.45, 6.89), and 0.22 (0.07, 1.86) in non-infection SIRS patients or the patients with bacterial, fungal, and mixed infection, respectively. The peak level of PCT (μg/L) were 4.19 (1.95, 13.42), 12.37 (3.82, 45.89), 1.82 (0.49, 17.86), and 5.14 (2.66, 12.62), respectively, in each subgroup. When the comparison was conducted among the patients with different infectious agent, the baseline level of PCT in patients with bacterial infection was significantly higher than that in SIRS patients without infection (P=0.026) and mixed infection patients (P=0.001), and the peak level of PCT was significantly higher than that in the SIRS patients without infection (P=0.009) and the patients with fungal infection (P=0.016). ROC curve showed that the higher value was found in the baseline and peak levels of PCT for diagnosis of septic shock in all patients [ area under ROC curve (AUC) of baseline level=0.681±0.054, P=0.001; AUC of peak level=0.690±0.054, P=0.002], and the same value was also found in the baseline and peak levels of PCT for diagnosis of bacterial infection in the patients with malignant hematological tumor (AUC of baseline level=0.687±0.080, P=0.008; AUC of peak level=0.697±0.079, P=0.021). (3) The peak level of PCT (μg/L) were 4.05 (0.53, 31.22), 5.78 (2.14, 16.68), and 11.64 (2.94, 58.14) in subgroup of patients with sepsis, severe sepsis and septic shock, respectively, and they showed no statistical significance among subgroups (P>0.05). A high serum level of peak PCT strongly indicated the presence of septic shock (AUC=0.646±0.060, P=0.019), especially in the subgroup of patients with systemic autoimmune disease (AUC=0.689±0.081, P=0.035). (4) The peak level of PCT (μg/L) in the APACHEII>18 group (38 cases) was significantly higher than that of APACHEII≤18 group [ 60 cases, PCT (μg/L): 11.64 (3.36, 39.39) vs. 4.42 (1.32, 14.70), P=0.016]; there was a certain correlation between the peak level of PCT and the severity of the disease. (5) The peak level of PCT in death group was significantly higher than that of the survival group [μg/L: 9.07 (3.05, 33.09) vs. 4.19 (1.26, 14.61), P=0.043]. ROC curve showed that the peak level of PCT might be valuable in predicting the prognosis in immunocompromised patients (AUC=0.619±0.057, P=0.043). The serum level of PCT is found to be a reliable marker for the diagnosis of bacterial infection in immunocompromised critical patients, especially in those with hematologic malignancy. Additionally, PCT provides a useful tool for evaluating the severity of infection and the prognosis of critically ill patients.

Optical absorption of zigzag single walled boron nitride nanotubes

NASA Astrophysics Data System (ADS)

Moradian, Rostam; Chegel, Raad; Behzad, Somayeh

2010-11-01

In a realistic three-dimensional model, optical matrix element and linear optical absorption of zigzag single walled boron nitride nanotubes (BNNTs) in the tight binding approximation are studied. In terms of absolute value of dipole matrix elements of the first three direct transitions at kz=0, we divided the zigzag BNNTs into three groups and investigated their optical absorption spectrum in energy ranges E<5, 77.5 eV. We found that in lower energies, E<5 eV, all groups show different behaviors while in the higher energies, 77.5 eV, their behaviors depend on their even or odd nanotube index. We also found that in the energy range 7

Kinematic Measurements of the Vocal-Fold Displacement Waveform in Typical Children and Adult Populations: Quantification of High-Speed Endoscopic Videos

PubMed Central

Donohue, Kevin D.; Unnikrishnan, Harikrishnan; Kryscio, Richard J.

2015-01-01

Purpose This article presents a quantitative method for assessing instantaneous and average lateral vocal-fold motion from high-speed digital imaging, with a focus on developmental changes in vocal-fold kinematics during childhood. Method Vocal-fold vibrations were analyzed for 28 children (aged 5–11 years) and 28 adults (aged 21–45 years) without voice disorders. The following kinematic features were analyzed from the vocal-fold displacement waveforms: relative velocity-based features (normalized average and peak opening and closing velocities), relative acceleration-based features (normalized peak opening and closing accelerations), speed quotient, and normalized peak displacement. Results Children exhibited significantly larger normalized peak displacements, normalized average and peak opening velocities, normalized average and peak closing velocities, peak opening and closing accelerations, and speed quotient compared to adult women. Values of normalized average closing velocity and speed quotient were higher in children compared to adult men. Conclusions When compared to adult men, developing children typically have higher estimates of kinematic features related to normalized displacement and its derivatives. In most cases, the kinematic features of children are closer to those of adult men than adult women. Even though boys experience greater changes in glottal length and pitch as they mature, results indicate that girls experience greater changes in kinematic features compared to boys. PMID:25652615

Shock wave treatment shows dose-dependent enhancement of bone mass and bone strength after fracture of the femur.

PubMed

Wang, Ching-Jen; Yang, Kuender D; Wang, Feng-Sheng; Hsu, Chia-Chen; Chen, Hsiang-Ho

2004-01-01

Shock wave treatment is believed to improve bone healing after fracture. The purpose of this study was to evaluate the effect of shock wave treatment on bone mass and bone strength after fracture of the femur in a rabbit model. A standardized closed fracture of the right femur was created with a three-point bending method in 24 New Zealand white rabbits. Animals were randomly divided into three groups: (1) control (no shock wave treatment), (2) low-energy (shock wave treatment at 0.18 mJ/mm2 energy flux density with 2000 impulses), and (3) high-energy (shock wave treatment at 0.47 mJ/mm2 energy flux density with 4000 impulses). Bone mass (bone mineral density (BMD), callus formation, ash and calcium contents) and bone strength (peak load, peak stress and modulus of elasticity) were assessed at 12 and 24 weeks after shock wave treatment. While the BMD values of the high-energy group were significantly higher than the control group (P = 0.021), the BMD values between the low-energy and control groups were not statistically significant (P = 0.358). The high-energy group showed significantly more callus formation (P < 0.001), higher ash content (P < 0.001) and calcium content (P = 0.003) than the control and low-energy groups. With regard to bone strength, the high-energy group showed significantly higher peak load (P = 0.012), peak stress (P = 0.015) and modulus of elasticity (P = 0.011) than the low-energy and control groups. Overall, the effect of shock wave treatment on bone mass and bone strength appears to be dose dependent in acute fracture healing in rabbits.

Trophic diversity, size and biomass spectrum of Bay of Bengal nematodes: A study case on depth and latitudinal patterns

NASA Astrophysics Data System (ADS)

Ansari, Kapuli Gani Mohamed Thameemul; Lyla, Somasundharanair; Khan, Syed Ajmal; Bhadury, Punyasloke

2017-09-01

Depth and latitudinal patterns of nematode functional attributes were investigated from 35 stations of Bay of Bengal (BoB) continental shelf. We aim to address whether depth and latitudinal variations can modify nematode community structure and their functional attributes (trophic diversity, size and biomass spectra). Global trend of depth and latitudinal related variations have also been noticed from BoB shelf in terms of nematode abundance and species richness, albeit heterogeneity patterns were encountered in functional attributes. Index of trophic diversity values revealed higher trophic diversity across the BoB shelf and suggested variety of food resource availability. However, downstream analysis of trophic status showed depth and latitude specific patterns but not reflected in terms of size and biomass spectrum. The peaks at different positions clearly visualized heterogeneity in distribution patterns for both size and biomass spectrum and also there was evidence of availability of diversified food resources. Nematode biomass spectra (NBS) constructed for nematode communities showed shift in peak biomass values towards lower to moderate size classes particularly in shallower depth but did not get reflected in latitudes. However, Chennai and Parangipettai transects demonstrated shift in peak biomass values towards higher biomass classes explaining the representation of higher nematode abundance. Our findings concluded that depth and latitudes are physical variables; they may not directly affect nematode community structure and functional attributes but they might influence the other factors such as food availability, sediment deposition and settlement rate. Our observations suggest that the local factors (seasonal character) of phytodetrital food flux can be very important for shaping the nematode community structure and success of nematode functional heterogeneity patterns across the Bay of Bengal shelf.

Scenario analysis on the goal of carbon emission peaking around 2030 of China proposed in the China-U.S. joint statement on climate change

NASA Astrophysics Data System (ADS)

Zheng, T.

2015-12-01

A goal of carbon (C) emission peaking around 2030 of China was declared in the China-U.S. joint statement on climate change, and emphasized in China's intended nationally determined contributions (INDC). Here, we predicted the carbon emission of China during the period 2011~2050 under seven scenarios, and analyzed the scientific and social implications of realizing the goal. Our results showed that: (1) C emissions of China will reach their peaks at 2022~2045 (with peak values 3.15~5.10 Pg C), and the predicted decay rates of C intensity were 2.1~4.2% in 2011~2050; (2) the precondition that the national C emission reaches the peak before 2030 is that the annual decay rates of C intensity must exceed 3.3% , as decay rates under different scenarios were predicted higher than that except for Past G8 scenario; (3) the national C emission would reach the peak before 2030, if the government of China should realize the C emissions reduction goals of China's 12th five-year plan, climate commitments of Copenhagen and INDC; (4) Chinese government could realize the goal of C emission peaking around 2030 from just controlling C emission intensity , but associated with relatively higher government's burden. In summary, China's C emission may well peak before 2030, meanwhile the combination of emissions reduction and economic macro-control would be demanded to avoid heavier social pressure of C emissions reduction occurred.

Evaluation of fracture torque resistance of orthodontic mini-implants.

PubMed

Dalla Rosa, Fernando; Burmann, Paola Fp; Ruschel, Henrique C; Vargas, Ivana A; Kramer, Paulo F

2016-12-01

This study sought to assess the fracture torque resistance of mini-implants used for orthodontic anchorage. Five commercially available brands of mini-implants were used (SIN®, CONEXÃO®, NEODENT®, MORELLI®, andFORESTADENT®). Ten mini-implants of each diameter of each brand were tested, for a total 100 specimens. The mini-implants were subject to a static torsion test as described in ASTMstandard F543. Analysis of variance (ANOVA) with the Tukey multiple comparisons procedure was used to assess results. Overall, mean fracture strength ranged from 15.7 to 70.4 N·cm. Mini-implants with larger diameter exhibited higher peak torque values at fracture and higher yield strength, regardless of brand. In addition, significant differences across brands were observed when implants were stratified by diameter. In conclusion, larger mini-implant diameter is associated with increased fracture torque resistance. Additional information on peak torque values at fracture of different commercial brands of mini-implants may increase the success rate of this orthodontic anchorage modality. Sociedad Argentina de Investigación Odontológica.

Effects of tenotomy on patients with infantile nystagmus syndrome: foveation improvement over a broadened visual field.

PubMed

Wang, Zhong; Dell'Osso, Louis F; Jacobs, Jonathan B; Burnstine, Robert A; Tomsak, Robert L

2006-12-01

To investigate the effects of four-muscle tenotomy on visual function and gaze angle in patients with infantile nystagmus syndrome (INS). Eye movements of nine patients with infantile nystagmus were recorded using infrared reflection or high-speed digital video techniques. Experimental protocols were designed to record the patients' eye-movement waveforms, pre- and post-tenotomy, at different gaze angles. We used the eXpanded Nystagmus Acuity Function (NAFX) to measure tenotomy-induced changes in the nystagmus at primary position and various gaze angles. The longest foveation domains (LFD) were measured from fitted curves. Peak-to-peak nystagmus amplitudes and foveation-period durations were also measured. All measurements were made unmasked. All seven patients with narrow, high-NAFX, gaze-angle regions showed broadening of these regions of higher visual function. Three patients showed moderate NAFX improvement (13.9-32.6%) at primary position, five showed large improvement (39.9-162.4%), and one showed no NAFX change (due to his high pretenotomy NAFX). Primary position measured acuities improved in six patients. All patients had reductions in nystagmus amplitudes ranging from 14.6 to 37%. The duration of the foveation period increased in all nine patients (11.2-200%). The percentage improvements in both the NAFX and the LFD decreased with higher pretenotomy values. In addition to elevating primary position NAFX, tenotomy also broadens the high-NAFX regions. This broadening effect is more prominent in patients who had sharp pretenotomy NAFX peaks. Four-muscle tenotomy produces higher primary position NAFX increases in infantile nystagmus patients whose pretenotomy values are relatively low, with the improvement decreasing at higher pretenotomy values. The tenotomy procedure improves visual function beyond primary position acuity. This extends the utility of surgical therapy to several different classes of patients with INS for whom other procedures are contraindicated. The pretenotomy NAFX can now be used to predict both primary position acuity improvements and broadening of a patient's high-NAFX range of gaze angles.

Plasmon assisted enhanced nonlinear refraction of monodispersed silver nanoparticles and their tunability.

PubMed

Lama, Pemba; Suslov, Anatoliy; Walser, Ardie D; Dorsinville, Roger

2014-06-02

Nonlinear optical characterizations were performed on monodispersed silver (Ag) nanoparticles (NPs) of various sizes using a picosecond Z-scan technique with excitation wavelengths of 532 nm and 1064 nm. The Ag NPs were fabricated using a heterogeneous condensation technique in a gas medium. The nonlinear refraction values were higher for the monodispersed Ag NPs whose surface plasmon resonance (SPR) peak is closer to the excitation wavelength. The higher nonlinear optical response is explained in terms of an electric field enhancement near the SPR. Moreover, the fabrication method allows the tailoring of the nonlinear refraction index of the Ag NPs by tuning the SPR peak of the sample. A comparison of the nonlinear refraction index of the monodispersed and polydispersed Ag NPs showed that the nonlinear refractive index of the monodispersed Ag NPs is higher.

Design of Quad-Band Terahertz Metamaterial Absorber Using a Perforated Rectangular Resonator for Sensing Applications.

PubMed

Xie, Qin; Dong, Guangxi; Wang, Ben-Xin; Huang, Wei-Qing

2018-05-08

Quad-band terahertz absorber with single-sized metamaterial design formed by a perforated rectangular resonator on a gold substrate with a dielectric gap in between is investigated. The designed metamaterial structure enables four absorption peaks, of which the first three peaks have large absorption coefficient while the last peak possesses a high Q (quality factor) value of 98.33. The underlying physical mechanisms of these peaks are explored; it is found that their near-field distributions are different. Moreover, the figure of merit (FOM) of the last absorption peak can reach 101.67, which is much higher than that of the first three absorption modes and even absorption bands of other works operated in the terahertz frequency. The designed device with multiple-band absorption and high FOM could provide numerous potential applications in terahertz technology-related fields.

Design of Quad-Band Terahertz Metamaterial Absorber Using a Perforated Rectangular Resonator for Sensing Applications

NASA Astrophysics Data System (ADS)

Xie, Qin; Dong, Guangxi; Wang, Ben-Xin; Huang, Wei-Qing

2018-05-01

Quad-band terahertz absorber with single-sized metamaterial design formed by a perforated rectangular resonator on a gold substrate with a dielectric gap in between is investigated. The designed metamaterial structure enables four absorption peaks, of which the first three peaks have large absorption coefficient while the last peak possesses a high Q (quality factor) value of 98.33. The underlying physical mechanisms of these peaks are explored; it is found that their near-field distributions are different. Moreover, the figure of merit (FOM) of the last absorption peak can reach 101.67, which is much higher than that of the first three absorption modes and even absorption bands of other works operated in the terahertz frequency. The designed device with multiple-band absorption and high FOM could provide numerous potential applications in terahertz technology-related fields.

Effect of Anticipation on Lower Extremity Biomechanics During Side- and Cross-Cutting Maneuvers in Young Soccer Players.

PubMed

Kim, Jin Hyun; Lee, Ki-Kwang; Kong, Se Jin; An, Keun Ok; Jeong, Jin Hwa; Lee, Yong Seuk

2014-08-01

Less mature athletes exhibit biomechanical parameters during cutting maneuvers that may place these athletes at greater risk for injury than their more mature counterparts, especially if the maneuvers are unanticipated. However, most studies on risk factors for anterior cruciate ligament (ACL) injury have focused on neuromuscular and knee kinematic differences between the sexes, not on the biomechanical parameters between specific sporting maneuvers. (1) Anticipation will have a greater effect than the type of cutting maneuver (side- vs cross-cutting) in terms of the biomechanical risk factors for ACL injuries, and (2) the biomechanical risk factors will be different between the 2 types of maneuvers. Controlled laboratory study. Thirty-seven young, male middle school soccer players participated in this study. Three-dimensional motion analysis featuring ground-reaction force and electromyography of the right leg was used. Kinematics, kinetics, and electromyography data for each athlete were analyzed during anticipated and unanticipated side- and cross-cutting maneuvers. The differences between anticipated and unanticipated states as well as between side- and cross-cutting maneuvers were calculated and compared. After unanticipated side-cutting, the time to peak ground-reaction force was longer and peak values were smaller compared with anticipated side-cutting. Flexion, valgus, and internal rotations in the knee joint were larger, and greater flexion and valgus moments were observed. The vastus lateralis and vastus medialis showed lower activity, and the lateral gastrocnemius showed higher activity after unanticipated side-cutting maneuvers. With unanticipated cross-cutting, the time to peak ground-reaction force was longer and peak values were smaller compared with anticipated cross-cutting, and the lateral gastrocnemius showed higher activity. Differences in the peak values of the mediolateral and vertical forces were smaller in the cross-cutting maneuver than in side-cutting. Changes in flexion and adduction of the hip joint, flexion of the knee joint, and inversion of the ankle joint were larger during side-cutting. Although there were some interactions between direction and anticipation, anticipating a cutting maneuver generally had a greater effect than the type of maneuver when there was no significant interaction. Increases in the valgus angle and moment of the knee joint and higher lateral gastrocnemius activity during the late period showed an association with ACL injury risk factors during side-cutting, and higher lateral gastrocnemius activity during the early period showed an association with injury risk factors during cross-cutting. © 2014 The Author(s).

An in vitro investigation of peak insertion torque values of six commercially available mini-implants.

PubMed

Whang, C Z Y; Bister, D; Sherriff, M

2011-12-01

This study compared peak insertion torque values of six commercially available self-drilling mini-implants [Mini Spider® screw (1.5 × 8 mm), Infinitas® (1.5 × 9 mm), Vector TAS® (1.4 × 8 mm), Dual Top® (1.6 × 8 mm), Tomas Pin® (1.6 × 8 mm), and Ortho-Easy® (1.7 × 6, 8, and 10 mm)]. Twenty implants each were drilled into acrylic rods at a speed of 8 rpm using a motorized torque measurement stand, and the values were recorded in Newton centimetres (Ncm). A further 20 Ortho-Easy® implants with a length of 6 and 10 mm were tested at 8 rpm; 20 implants of 6 mm length were also tested at 4 rpm. Kaplan-Meier estimates of the peak torque values were compared using the log-rank test with multiple comparisons evaluated by Sidak's test. There were significant differences in the maximum torque values for different mini-implants with the same length. The Mini Spider® screw and Infinitas® showed the lowest average torque values (6.5 and 12.4 Ncm) compared with Vector TAS®, Dual ToP®, Tomas Pin®, and Ortho-Easy® (30.9, 29.4, 25.4, and 24.8 Ncm, respectively). There was no correlation between the diameter of the implants and torque values. The Tomas Pin® showed the largest standard deviation (7.7 Ncm) and the Dual Top® implant the smallest (0.6 Ncm). Different insertion speeds did not result in significant differences in peak torque values but the 6 mm mini-implants showed significantly higher torque values than the 8 and 10 mm implants. Using a 'torque limiting' screwdriver or pre-drilling cortical bone to reduce insertion, torque appears justified for some of the tested implants.

F2 layer characteristics and electrojet strength over an equatorial station

NASA Astrophysics Data System (ADS)

Adebesin, B. O.; Adeniyi, J. O.; Adimula, I. A.; Reinisch, B. W.; Yumoto, K.

2013-09-01

The data presented in this work describes the diurnal and seasonal variation in hmF2, NmF2, and the electrojet current strength over an African equatorial station during a period of low solar activity. The F2 region horizontal magnetic element H revealed that the Solar quiet Sq(H) daily variation rises from early morning period to maximum around local noon and falls to lower values towards evening. The F2 ionospheric current responsible for the magnetic field variations is inferred to build up at the early morning hours, attaining maximum strength around 1200 LT. The Sq variation across the entire months was higher during the daytime than nighttime. This is ascribed to the variability of the ionospheric parameters like conductivity and winds structure in this region. Seasonal daytime electrojet (EEJ) current strength for June solstice, March and September equinoxes, respectively had peak values ranging within 27-35 nT (at 1400 LT) , 30-40 nT (at 1200 LT) and 35-45 nT (at 1500 LT). The different peak periods of the EEJ strength were attributed to the combined effects of the peak electron density and electric field. Lastly, the EEJ strength was observed to be higher during the equinoxes than the solstice period.

Radio science with voyager 1 at jupiter: preliminary profiles of the atmosphere and ionosphere.

PubMed

Eshleman, V R; Tyler, G L; Wood, G E; Lindal, G F; Anderson, J D; Levy, G S; Croft, T A

1979-06-01

A preliminarv profile of the atmosphere of Jupiter in the South Equatorial Belt shows (i) the tropopause occurring at a pressure level of 100 millibars and temperature of about 113K, (ii) a higher warm inversion layer at about the 35-millibar level, and (iii) a lower-altitude constant lapse rate matching the adiabatic value of about 2 K per kilometer, with the temperatutre reaching 150 K at the 600-millibar level. Preliminary afternoon and predawn ionospheric profiles at 12 degrees south latitude and near the equator, respectively, have topside plasma scale heights of 590 kilometers changing to 960 kilometers above an altitucde of 3500 kilometers for the dayside, and about 960 kilomneters at all measured heights above the peak for the nightside. The higher value of scale height corresponds to a plasma temperature of 1100 K under the assumption of a plasma of protons and electrons in ambipolar diffusive equilibrium. The peak electron concentration in the upper ionosphere is approximately 2 x 10(5) per cubic centimeter for the dayside and about a factor of 10 less for the nightside. These peaks occur at altitudes of 1600 and 2300 kilometers, respectively. Continuing analyses are expected to extend and refine these results, and to be used to investigate other regions and phenomena.

[Study of the fluorescence characteristics of DOM from the Yangtze River and Jialing River around Chongqing's urban areas].

PubMed

Ji, Fang-ying; Li, Si; Zhou, Guang-ming; Yu, Dan-ni; Wang, Tu-jin; Cao, Lin; Tan, Xue-mei; Yang, Da-cheng; Zhou, Xiao-yi

2010-01-01

The fluorescence emission and excitation emission matrix (EEM) technologies were used to characterize the dissolved organic matter (DOM) in the water body of the Yangtze River and Jialing River around the Chongqing urban areas from April to August 2008. Concerning about the accidents of the Wenchuan's Earthquake in May and Tangjiashan Yansaihu's effects in June, and the high water period time in the summer in two months of July and August, from the EEM obtained from each sampling station and time, the composition, distribution and their changing features of the DOM in the two rivers were investigated as combined with the water samples' environmental parameters such as pH, DO, DOC with EEM's fingerprint features, f(450/500) etc; finally the bio-environment behavior effects of the three types of fluorescence peaks were elaborated, where humic-like, fulvic-like, and protein-like from the five sampling stations' EEMs during the five months were given detailed representation. From the experimental results obtained, the fluorescence peaks are mainly composed of two types of fluorophores: humic-like and protein-like in the two rivers around the Chongqing urban areas during the investigation in five months, the protein-like's peaks value in Jialing River is higher than the values in the Yangtze River, and all the fluorescence peaks in the two Rivers' water body decrease more or less after the two Rivers join in Chun Tan sampling station; the protein-like peak is notably higher after the "5 x 12" earthquake period time including May and June and high water period time, which mainly originated from terrestrial sources, but its intensities decreased observably while the water bodies of the two rivers joining together in the Chao Tianmen and Chun Tan's sampling station.

Effects of intravenous temazepam. II. A study of the long-term reproducibility of pharmacokinetics, pharmacodynamics, and concentration-effect parameters.

PubMed

van Steveninck, A L; Schoemaker, H C; den Hartigh, J; Pieters, M S; Breimer, D D; Cohen, A F

1994-05-01

To evaluate the long-term reproducibility of pharmacokinetic, pharmacodynamic, and concentration-effect parameters after intravenous administration of temazepam. Nine healthy volunteers were studied. Temazepam, 0.4 mg/kg, was infused intravenously for 30 minutes on two occasions 6 months apart. Venous plasma concentrations of temazepam were measured by HPLC in samples obtained between 0 and 24 hours. Pharmacodynamic effects were evaluated up to 8 hours for saccadic peak velocity and electroencephalogram (EEG) beta amplitudes. Subjects' state and trait anxiety were assessed by use of the Spielberger anxiety inventory. Significant correlations between occasions were found for area under the plasma concentration-time curve (AUC) values (r = 0.91; p < 0.01) but not for maximum concentration and half-life. Significant correlations were also found for area under the effect-time curve (AUEC) values of peak velocity (r = 0.88; p < 0.01) but not for peak velocity (r = 0.48; p > 0.05). Significant differences between the slopes of concentration effect plots on different occasions were observed in two subjects for EEG beta and in three subjects for peak velocity, with one subject showing a similar change for both parameters. Trait anxiety scores were higher on the first occasion (33 +/- 7) than on the second occasion (29 +/- 7; p < 0.01). A negative correlation was found between trait anxiety scores and the slopes of concentration-effect plots for peak velocity (r = -0.63; p < 0.01). For AUC and AUEC values the results indicate a reasonable long-term reproducibility of differences between subjects in the pharmacokinetics and pharmacodynamics of temazepam. However, there were limitations to the predictive value of derived concentration-effect parameters.

Effect of temperature on excess post-exercise oxygen consumption in juvenile southern catfish (Silurus meridionalis Chen) following exhaustive exercise.

PubMed

Zeng, Ling-Qing; Zhang, Yao-Guang; Cao, Zhen-Dong; Fu, Shi-Jian

2010-12-01

The effects of temperature on resting oxygen consumption rate (MO2rest) and excess post-exercise oxygen consumption (EPOC) after exhaustive exercise (chasing) were measured in juvenile southern catfish (Silurus meridionalis) (8.40±0.30 g, n=40) to test whether temperature has a significant influence on MO2rest, maximum post-exercise oxygen consumption rate (MO2peak) and EPOC and to investigate how metabolic scope (MS: MO2peak - MO2rest) varies with acclimation temperature. The MO2rest increased from 64.7 (10°C) to 160.3 mg O2 h(-1) kg(-1) (25°C) (P<0.05) and reached a plateau between 25 and 30°C. The post-exercise MO2 in all temperature groups increased immediately to the peak values and then decreased slowly to a steady state that was higher than the pre-exercise MO2. The MO2peak did not significantly differ among the 20, 25 and 30°C groups, though these values were much higher than those of the lower temperature groups (10 and 15°C) (P<0.05). The duration of EPOC varied from 32.9 min at 10°C to 345 min at 20°C, depending on the acclimation temperatures. The MS values of the lower temperature groups (10 and 15°C) were significantly smaller than those of the higher temperature groups (20, 25 and 30°C) (P<0.05). The magnitude of EPOC varied ninefold among all of the temperature groups and was the largest for the 20°C temperature group (about 422.4 mg O2 kg(-1)). These results suggested that (1) the acclimation temperature had a significant effect on maintenance metabolism (as indicated by MO2rest) and the post-exercise metabolic recovery process (as indicated by MO2peak, duration and magnitude of EPOC), and (2) the change of the MS as a function of acclimation temperature in juvenile southern catfish might be related to their high degree of physiological flexibility, which allows them to adapt to changes in environmental conditions in their habitat in the Yangtze River and the Jialing River.

Local SAR in High Pass Birdcage and TEM Body Coils for Multiple Human Body Models in Clinical Landmark Positions at 3T

PubMed Central

Yeo, Desmond TB; Wang, Zhangwei; Loew, Wolfgang; Vogel, Mika W; Hancu, Ileana

2011-01-01

Purpose To use EM simulations to study the effects of body type, landmark position, and RF body coil type on peak local SAR in 3T MRI. Materials and Methods Numerically computed peak local SAR for four human body models (HBMs) in three landmark positions (head, heart, pelvic) were compared for a high-pass birdcage and a transverse electromagnetic 3T body coil. Local SAR values were normalized to the IEC whole-body average SAR limit of 2.0 W/kg for normal scan mode. Results Local SAR distributions were highly variable. Consistent with previous reports, the peak local SAR values generally occurred in the neck-shoulder area, near rungs, or between tissues of greatly differing electrical properties. The HBM type significantly influenced the peak local SAR, with stockier HBMs, extending extremities towards rungs, displaying the highest SAR. There was also a trend for higher peak SAR in the head-centric and heart-centric positions. The impact of the coil-types studied was not statistically significant. Conclusion The large variability in peak local SAR indicates the need to include more than one HBM or landmark position when evaluating safety of body coils. It is recommended that a HBM with arms near the rungs be included, to create physically realizable high-SAR scenarios. PMID:21509880

Serum C-reactive protein in patients undergoing elective shoulder arthroplasty. Prospective study.

PubMed

Torrens, Carlos; Santana, Fernando; Marí, Raquel; Puig, Lluis; Alier, Albert

2017-09-01

The objective of the study was to determine the normalization curve of the serum C-reactive protein (CRP) in elective shoulder arthroplasty. A prospective study including 58 consecutive patients who had undergone elective shoulder arthroplasty. Forty-one patients had received a Reverse Shoulder Arthroplasty, 13 a Total Shoulder Arthroplasty and 4 a Hemiarthroplasty. Based on a pilot study, blood samples to determine CRP values were obtained at baseline (1 h before surgery), on the 1st, 2nd, 6th, 8th and 14th postoperative days. All the patients included presented no postoperative complications during inpatient stay or any re-admission during the three months after surgery. Mean CRP values showed a rapid increase on the 1st postoperative day (7-fold higher than the baseline in cuff tear arthropathy, 11-fold higher in primary osteoarthritis, 1-fold higher in acute fracture) and reached a peak on the 2nd postoperative day (14-fold higher than the baseline in cuff tear arthropathy, 24-fold higher in primary osteoarthritis and 2-fold higher in acute fracture). After the 2nd postoperative day CRP values began to slowly decrease reaching the normal range in the 14th postoperative day. Serum CRP levels after elective shoulder arthroplasty rapidly increase to reach a maximum peak after the 2nd surgery day and then slowly decrease to return to normality on the 14th day. Knowing the normalization curve of CRP can be a helpful tool to help in the diagnosis of acute infections in elective shoulder arthroplasty. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Theoretical study of thermoelectric properties of few-layer MoS2 and WSe2.

PubMed

Huang, Wen; Luo, Xin; Gan, Chee Kwan; Quek, Su Ying; Liang, Gengchiau

2014-06-14

Molybdenum disulfide (MoS2) and tungsten diselenide (WSe2) are prototypical layered two-dimensional transition metal dichalcogenide materials, with each layer consisting of three atomic planes. We refer to each layer as a trilayer (TL). We study the thermoelectric properties of 1-4TL MoS2 and WSe2 using a ballistic transport approach based on the electronic band structures and phonon dispersions obtained from first-principles calculations. Our results show that the thickness dependence of the thermoelectric properties is different under n-type and p-type doping conditions. Defining ZT1st peak as the first peak in the thermoelectric figure of merit ZT as doping levels increase from zero at 300 K, we found that ZT1st peak decreases as the number of layers increases for MoS2, with the exception of 2TL in n-type doping, which has a slightly higher value than 1TL. However, for WSe2, 2TL has the largest ZT1st peak in both n-type and p-type doping, with a ZT1st peak value larger than 1 for n-type WSe2. At high temperatures (T > 300 K), ZT1st peak dramatically increases when the temperature increases, especially for n-type doping. The ZT1st peak of n-type 1TL-MoS2 and 2TL-WSe2 can reach 1.6 and 2.1, respectively.

Additive prognostic value of interleukin-6 at peak phase of dobutamine stress echocardiography in patients with coronary artery disease. A 6-year follow-up study.

PubMed

Ikonomidis, Ignatios; Athanassopoulos, George; Stamatelopoulos, Kimon; Lekakis, John; Revela, Ioanna; Venetsanou, Kiriaki; Marinou, Margarita; Monaco, Claudia; Cokkinos, Dennis V; Nihoyannopoulos, Petros

2008-08-01

Interleukin-6 (IL-6) and tissue factor (TF) are elevated after myocardial ischemia during dobutamine stress echo (DSE). We examined the incremental prognostic value of IL-6 or TF measured during DSE over echocardiographic and clinical factors in patients with chronic coronary artery disease (CAD). We studied 106 patients with angiographically documented CAD. IL-6 and TF were measured at rest, peak, and during recovery. A wall motion score index was calculated. Fifty-seven (54%) patients had ischemia at DSE. During follow-up (63.7 +/- 20 months), 36 patients (33%) had an adverse event (12 cardiac deaths, 24 acute coronary events). Patients with events had a higher peak IL-6 (P = .02) but similar rest and recovery IL-6 than those without. Patients with peak IL-6 > or =3.14 pg/mL (upper tertile) had a hazard ratio of 2.7 (95% CI 1.44-5.37) (P < .01 for an adverse event). The addition of peak wall motion score index in a multivariable model including risk factors, ejection fraction, revascularization, and multivessel disease increased the model's c statistic from 0.66 to 0.70 (P = .04). The addition of peak IL-6 further increased the model's c statistic to 0.75 (P = .04). Tissue factor was not related with cardiac events. Interleuikin-6 levels measured during the peak phase of DSE incrementally contribute to risk stratification in patients with chronic CAD.

Upper limb joint kinetic analysis during tennis serve: Assessment of competitive level on efficiency and injury risks.

PubMed

Martin, C; Bideau, B; Ropars, M; Delamarche, P; Kulpa, R

2014-08-01

The aim of this work was to compare the joint kinetics and stroke production efficiency for the shoulder, elbow, and wrist during the serve between professionals and advanced tennis players and to discuss their potential relationship with given overuse injuries. Eleven professional and seven advanced tennis players were studied with an optoelectronic motion analysis system while performing serves. Normalized peak kinetic values of the shoulder, elbow, and wrist joints were calculated using inverse dynamics. To measure serve efficiency, all normalized peak kinetic values were divided by ball velocity. t-tests were used to determine significant differences between the resultant joint kinetics and efficiency values in both groups (advanced vs professional). Shoulder inferior force, shoulder anterior force, shoulder horizontal abduction torque, and elbow medial force were significantly higher in advanced players. Professional players were more efficient than advanced players, as they maximize ball velocity with lower joint kinetics. Since advanced players are subjected to higher joint kinetics, the results suggest that they appeared more susceptible to high risk of shoulder and elbow injuries than professionals, especially during the cocking and deceleration phases of the serve. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Equivalent peak resolution: characterization of the extent of separation for two components based on their relative peak overlap.

PubMed

Dvořák, Martin; Svobodová, Jana; Dubský, Pavel; Riesová, Martina; Vigh, Gyula; Gaš, Bohuslav

2015-03-01

Although the classical formula of peak resolution was derived to characterize the extent of separation only for Gaussian peaks of equal areas, it is often used even when the peaks follow non-Gaussian distributions and/or have unequal areas. This practice can result in misleading information about the extent of separation in terms of the severity of peak overlap. We propose here the use of the equivalent peak resolution value, a term based on relative peak overlap, to characterize the extent of separation that had been achieved. The definition of equivalent peak resolution is not constrained either by the form(s) of the concentration distribution function(s) of the peaks (Gaussian or non-Gaussian) or the relative area of the peaks. The equivalent peak resolution value and the classically defined peak resolution value are numerically identical when the separated peaks are Gaussian and have identical areas and SDs. Using our new freeware program, Resolution Analyzer, one can calculate both the classically defined and the equivalent peak resolution values. With the help of this tool, we demonstrate here that the classical peak resolution values mischaracterize the extent of peak overlap even when the peaks are Gaussian but have different areas. We show that under ideal conditions of the separation process, the relative peak overlap value is easily accessible by fitting the overall peak profile as the sum of two Gaussian functions. The applicability of the new approach is demonstrated on real separations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Circadian rhythm of blood and urinary copper in presumably healthy subjects of vegetarian food habit

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

Bhattacharya, R.D.

Circadian rhythm of blood and urinary copper has been studied in presumably healthy subjects of a particular ethnic group in India who are vegetarians. A definite 24-hr variation has been observed for both blood and urinary copper. The peak for blood copper was 1500 hr and the lowest value was 0600 hr, with values of 0.185 mg/100 ml and 0.160 mg/100 ml respectively. The urinary peak and trough occurred at 0600 and 0300 hr, respectively. Remarkably higher 24-hr copper excretion values were noted (64.49 ..mu..g/day) with a range of 15-100 ..mu..g/day. The blood level of copper (0.134 mg/100 ml) remainedmore » within the range reported. One subject out of 25 deviated from the group with respect to circadian phasing and amplitude to urinary copper excretion. 20 references.« less

Analysis of three different equations for predicting quadriceps femoris muscle strength in patients with COPD *

PubMed Central

Nellessen, Aline Gonçalves; Donária, Leila; Hernandes, Nidia Aparecida; Pitta, Fabio

2015-01-01

Abstract Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations. PMID:26398750

The effect of chronic carbon-monoxide exposure on the peak expiratory flow values of grill-kebab chefs.

PubMed

Al, Behcet; Yildirim, Cuma; Zengin, Suat; Cavdar, Murat; Togun, Ismail

2009-06-01

To determine the effect of chronic carbon-monoxide (CO) exposure on blood carboxy-hemoglobin (COHb) values in grill-kebab chefs, and if there is any subsequent airway obstruction. The study was carried out in Sahinbey Hospital, Medical School of Gaziantep University, Gaziantep, Turkey, between March 2007 and November 2007. Forty male grill-kebab chefs, working in restaurants for at least 3 years, and 48 non-smoker, male healthy volunteers were gathered for this study. The ages, body mass indexes (BMI), blood pressure (BP), COHb, N-terminal pro brain natriuretic peptide (NT-proBNP), and peak expiratory flow (PEF) values of the grill-kebab chefs and controls was measured. Statistical analysis was carried out using the SSPS 13.0 software. The average age for the study group was 33.0 +/- 9.1, and for the control group was 34.7+/- 6.5 years. The average occupation time for the study group was 16.1+/-7.3 years. The clinical attributes, ages, BMI, BP, and NT-proBNP values of both groups were similar. The COHb (6.5+/-1.5/2.0+/-1.1%) values were higher in grill-kebab chefs compared with the control group. The NT-proBNP values were determined as normal (<60 microg/L) in both groups. A higher decrease in PEF speed (average: 65.1/7.1 L/min) was recorded in the grill-kebab chefs. Chronic exposure to CO decreases PEF, with narrowing of the airway in grill-kebab chefs.

Extraordinary rocks from the peak ring of the Chicxulub impact crater: P-wave velocity, density, and porosity measurements from IODP/ICDP Expedition 364

NASA Astrophysics Data System (ADS)

Christeson, G. L.; Gulick, S. P. S.; Morgan, J. V.; Gebhardt, C.; Kring, D. A.; Le Ber, E.; Lofi, J.; Nixon, C.; Poelchau, M.; Rae, A. S. P.; Rebolledo-Vieyra, M.; Riller, U.; Schmitt, D. R.; Wittmann, A.; Bralower, T. J.; Chenot, E.; Claeys, P.; Cockell, C. S.; Coolen, M. J. L.; Ferrière, L.; Green, S.; Goto, K.; Jones, H.; Lowery, C. M.; Mellett, C.; Ocampo-Torres, R.; Perez-Cruz, L.; Pickersgill, A. E.; Rasmussen, C.; Sato, H.; Smit, J.; Tikoo, S. M.; Tomioka, N.; Urrutia-Fucugauchi, J.; Whalen, M. T.; Xiao, L.; Yamaguchi, K. E.

2018-08-01

Joint International Ocean Discovery Program and International Continental Scientific Drilling Program Expedition 364 drilled into the peak ring of the Chicxulub impact crater. We present P-wave velocity, density, and porosity measurements from Hole M0077A that reveal unusual physical properties of the peak-ring rocks. Across the boundary between post-impact sedimentary rock and suevite (impact melt-bearing breccia) we measure a sharp decrease in velocity and density, and an increase in porosity. Velocity, density, and porosity values for the suevite are 2900-3700 m/s, 2.06-2.37 g/cm3, and 20-35%, respectively. The thin (25 m) impact melt rock unit below the suevite has velocity measurements of 3650-4350 m/s, density measurements of 2.26-2.37 g/cm3, and porosity measurements of 19-22%. We associate the low velocity, low density, and high porosity of suevite and impact melt rock with rapid emplacement, hydrothermal alteration products, and observations of pore space, vugs, and vesicles. The uplifted granitic peak ring materials have values of 4000-4200 m/s, 2.39-2.44 g/cm3, and 8-13% for velocity, density, and porosity, respectively; these values differ significantly from typical unaltered granite which has higher velocity and density, and lower porosity. The majority of Hole M0077A peak-ring velocity, density, and porosity measurements indicate considerable rock damage, and are consistent with numerical model predictions for peak-ring formation where the lithologies present within the peak ring represent some of the most shocked and damaged rocks in an impact basin. We integrate our results with previous seismic datasets to map the suevite near the borehole. We map suevite below the Paleogene sedimentary rock in the annular trough, on the peak ring, and in the central basin, implying that, post impact, suevite covered the entire floor of the impact basin. Suevite thickness is 100-165 m on the top of the peak ring but 200 m in the central basin, suggesting that suevite flowed downslope from the collapsing central uplift during and after peak-ring formation, accumulating preferentially within the central basin.

Salivary cortisol values in HIV-positive people.

PubMed

Barroso, Julie; Burrage, Joe; Carlson, John; Carlson, Barbara Waag

2006-01-01

Fatigue is one of the most prevalent and troubling symptoms suffered by people with HIV infection. As part of a pilot study to examine physiological and psychosocial correlates of fatigue, the authors report results from a sample of 40 HIV-positive men and women who collected three saliva samples each over the course of a day. Few in the sample exhibited the normal salivary cortisol slope (a peak in the morning and falling throughout the day). There were four groups (N = 36) based on salivary cortisol plots: a normal downward trend (n = 7), an afternoon peak (n = 15), an afternoon drop (n = 9), and an upward trend (n = 5). The data in each of these groups were then analyzed on the key variables of sex, age, depression, state/trait anxiety, fatigue severity, CD4 count, and HIV viral load; the group that had an upward trend in cortisol values had a tendency toward more depression, more state and trait anxiety, higher fatigue severity, and higher HIV viral load. However, they also trended toward higher CD4 counts than the other three groups. The need to compare additional variables over a period of time is discussed.

A 26 year physiological description of a National Hockey League team.

PubMed

Quinney, H A; Dewart, Randy; Game, Alex; Snydmiller, Gary; Warburton, Darren; Bell, Gordon

2008-08-01

The primary purpose of this investigation was to examine the physiological profile of a National Hockey League (NHL) team over a period of 26 years. All measurements were made at a similar time of year (pre-season) in 703 male (mean age +/- SD = 24 +/- 4 y) hockey players. The data were analyzed across years, between positions (defensemen, forwards, and goaltenders), and between what were deemed successful and non-successful years using a combination of points acquired during the season and play-off success. Most anthropometric (height, mass, and BMI) and physiological parameters (absolute and relative VO2 peak, relative peak 5 s power output, abdominal endurance, and combined grip strength) showed a gradual increase over the 26 year period. Defensemen were taller and heavier, had higher absolute VO2 peak, and had greater combined grip strength than forwards and goaltenders. Forwards were younger and had higher values for relative VO2 peak. Goaltenders were shorter, had less body mass, a higher sum of skinfolds, lower VO2 peak, and better flexibility. The overall pre-season fitness profile was not related to team success. In conclusion, this study revealed that the fitness profile for a professional NHL ice-hockey team exhibited increases in player size and anaerobic and aerobic fitness parameters over a 26 year period that differed by position. However, this evolution of physiological profile did not necessarily translate into team success in this particular NHL franchise.

β-decay Rates for Exotic Nuclei and r-process Nucleosynthesis up to Thorium and Uranium

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Shibagaki, Shota; Yoshida, Takashi; Kajino, Toshitaka; Otsuka, Takaharu

2018-06-01

Beta-decay rates for exotic nuclei with neutron magic number of N = 126 relevant to r-process nucleosynthesis are studied up to Z = 78 by shell-model calculations. The half-lives for the waiting-point nuclei obtained, which are short compared to a standard finite-range-droplet model, are used to study r-process nucleosynthesis in core-collapse supernova (CCSN) explosions and binary neutron star mergers. The element abundances are obtained up to the third peak as well as beyond the peak region up to thorium and uranium. The position of the third peak is found to be shifted toward a higher mass region in both CCSN explosions and neutron star mergers. We find that thorium and uranium elements are produced more with the shorter shell-model half-lives and their abundances come close to the observed values in CCSN explosions. In the case of binary neutron star mergers, thorium and uranium are produced consistently with the observed values independent of the half-lives.

[Fluorescence peak shift corresponding to high chlorophyll concentrations in inland water].

PubMed

Duan, Hong-Tao; Ma, Rong-Hua; Zhang, Yuan-Zhi; Zhang, Bai

2009-01-01

Hyperspectral remote sensing offers the potential to detect water quality variables such as Chl-a by using narrow spectral channels of less than 10 nm, which could otherwise be masked by broadband satellites such as Landsat TM. Fluorescence peak of the red region is very important for the remote sensing of inland and coastal waters, which is unique to phytoplankton Chl-a that takes place in this region. Based on in situ water sampling and field spectral measurement from 2004 to 2006 in Nanhu Lake, the features of the spectral reflectance were analyzed in detail with peak position shift. The results showed: An exponential fitting model, peak position = a(Chl-a)b, was developed between chlorophyll-a concentration and fluorescence peak shift, where a varies between 686.11 and 686.29, while b between 0.0062 and 0.0065. It was found that the better the spectral resolution, the higher the precision of the model. Except that, the average of peak shift showed a high correlation with the average of different Chl-a grades, and the determination coefficient (R2) was higher than 0.81. It contributed significantly to the increase in the accuracy of the derivation of chlorophyll values from remote sensing data in Nanhu Lake. There is satisfactory correspondence between hyperspectral models and chl-a concentration, therefore, it is possible to monitor the water quality of Nanhu lake throngh the hyperspetral remote sensing data.

An examination of a modified Yo-Yo test to measure intermittent running performance in rugby players.

PubMed

Dobbin, Nick; Moss, Samantha Louise; Highton, Jamie; Twist, Craig

2018-06-17

This study examined how starting each shuttle in the prone position altered the internal, external and perceptual responses to the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1). Using a randomized crossover design, 17 male rugby players completed the Yo-Yo IR1 and prone Yo-Yo IR1 on two separate occasions. External loads (via microtechnology), [Formula: see text], heart rate (HR) and rating of perceived exertion (RPE) were measured at 160, 280 and 440 m (sub-maximal) and when the test was terminated (peak). The pre-to-post change in blood lactate concentration (Δ[La] b ) was determined for both tests. All data were analysed using effect sizes (ES) and magnitude-based inferences. Between-trial differences (ES ± 90% CL) indicated that total distance was most likely lower (-1.87 ± 0.19), whereas other measures of peak external load were likely to very likely higher during the prone Yo-Yo IR1 (0.62-1.80). Sub-maximal RPE was likely to most likely higher (0.40-0.96) and peak RPE very likely higher (0.63 ± 0.41) in the prone Yo-Yo IR1. The change in [La] b was likely higher after the prone Yo-Yo IR1. Mean HR was possibly lower at 440 m (-0.25 ± 0.29) as was peak HR (-0.26 ± 0.25) in the prone Yo-Yo IR1. [Formula: see text], [Formula: see text] and [Formula: see text] were likely to very likely higher at 280 and 440 m (ES = 0.36-1.22), while peak values were possibly to likely higher (ES = 0.23-0.37) in the prone Yo-Yo IR1. Adopting a prone position during the Yo-Yo IR1 increases the internal, external and perceptual responses, placing greater emphasis on metabolically demanding actions typical of rugby.

Altitude exposures during commercial flight: a reappraisal.

PubMed

Hampson, Neil B; Kregenow, David A; Mahoney, Anne M; Kirtland, Steven H; Horan, Kathleen L; Holm, James R; Gerbino, Anthony J

2013-01-01

Hypobaric hypoxia during commercial air travel has the potential to cause or worsen hypoxemia in individuals with pre-existing cardiopulmonary compromise. Knowledge of cabin altitude pressures aboard contemporary flights is essential to counseling patients accurately about flying safety. The objective of the study was to measure peak cabin altitudes during U.S. domestic commercial flights on a variety of aircraft. A handheld mountaineering altimeter was carried by the investigators in the plane cabin during commercial air travel and peak cabin altitude measured. The values were then compared between aircraft models, aircraft classes, and distances flown. The average peak cabin altitude on 207 flights aboard 17 different aircraft was 6341 +/- 1813 ft (1933 m +/- 553 m), significantly higher than when measured in a similar fashion in 1988. Peak cabin altitude was significantly higher for flights longer than 750 mi (7085 +/- 801 ft) compared to shorter flights (5160 +/- 2290 ft/1573 +/- 698 m). Cabin altitude increased linearly with flight distance for flights up to 750 mi in length, but was independent of flight distance for flights exceeding 750 mi. Peak cabin altitude was less than 5000 ft (1524 m) in 70% of flights shorter than 500 mi. Peak cabin altitudes greater than 8000 ft (2438 m) were measured on approximately 10% of the total flights. Peak cabin altitude on commercial aircraft flights has risen over time. Cabin altitude is lower with flights of shorter distance. Physicians should take these factors into account when determining an individual's need for supplemental oxygen during commercial air travel.

Method and apparatus for analog pulse pile-up rejection

DOEpatents

De Geronimo, Gianluigi

2013-12-31

A method and apparatus for pulse pile-up rejection are disclosed. The apparatus comprises a delay value application constituent configured to receive a threshold-crossing time value, and provide an adjustable value according to a delay value and the threshold-crossing time value; and a comparison constituent configured to receive a peak-occurrence time value and the adjustable value, compare the peak-occurrence time value with the adjustable value, indicate pulse acceptance if the peak-occurrence time value is less than or equal to the adjustable value, and indicate pulse rejection if the peak-occurrence time value is greater than the adjustable value.

Method and apparatus for analog pulse pile-up rejection

DOEpatents

De Geronimo, Gianluigi

2014-11-18

A method and apparatus for pulse pile-up rejection are disclosed. The apparatus comprises a delay value application constituent configured to receive a threshold-crossing time value, and provide an adjustable value according to a delay value and the threshold-crossing time value; and a comparison constituent configured to receive a peak-occurrence time value and the adjustable value, compare the peak-occurrence time value with the adjustable value, indicate pulse acceptance if the peak-occurrence time value is less than or equal to the adjustable value, and indicate pulse rejection if the peak-occurrence time value is greater than the adjustable value.

Submicrosecond characteristics of lightning return-stroke currents

NASA Technical Reports Server (NTRS)

Leteinturier, Christiane; Hamelin, Joel H.; Eybert-Berard, Andre

1991-01-01

The authors describe the experimental results obtained during 1987 and 1988 triggered-lightning experiments in Florida. Seventy-four simultaneous submicrosecond time-resolved measurements of triggered return-stroke current (I) and current derivative (dI/dt) were made in Florida in 1987 and 1988. Peak currents ranged from about 5 to 76 kA, peak dI/dt amplitude from 13 to 411 kA/microsec and rise time from 90 to 1000 ns. The mean peak dI/dt values of 110 kA/microsec were 2-3 times higher than data from instrumented towers and peak I and dI/dt appear to be positively correlated. These data confirm previous experiments and conclusions supported by forty measurements. They are important in order to define, for example, standards for lightning protection. Present standards give a dI/dt maximum of 140 kA/microsec.

Sex-Related Differences in Self-Paced All Out High-Intensity Intermittent Cycling: Mechanical and Physiological Responses

PubMed Central

Panissa, Valéria L. G.; Julio, Ursula F.; França, Vanessa; Lira, Fabio S.; Hofmann, Peter; Takito, Monica Y.; Franchini, Emerson

2016-01-01

The purpose of this study was to compare sex-related responses to a self-paced all out high-intensity intermittent exercise (HIIE). 9 women and 10 men were submitted to a maximal incremental test (to determine maximum aerobic power - MAP and VO2peak), and an HIIE cycling (60x8s:12s, effort:pause). During the protocol the mean value of V̇O2 and heart rate for the entire exercise (VO2total and HRtotal) as well as the values only in the effort or pause (V̇O2effort, VO2pause and HReffort and HRpause) relative to VO2peak were measured. Anaerobic power reserve (APR), blood lactate [La] and the respiratory exchange ratio (RER) were also measured. These variables were compared between men and women using the unpaired t test. Men used greater APR (109 ± 12%MAP vs 92 ± 6%MAP) with similar V̇O2total (74 ± 7 vs 78 ± 8% VO2peak), however, when effort and pause were analysed separately, V̇O2effort (80 ± 9 vs 80 ± 5%VO2peak) was similar between sexes, while V̇O2pause was lower in men (69 ± 6% vs 77 ± 11% VO2peak, respectively). Women presented lower power decrement (30 ± 11 vs 11 ± 3%), RER (1.04 ± 0.03 vs 1.00 ± 0.02) and [La]peak (8.6 ± 0.9 vs 5.9 ± 2.3 mmol.L-1). Thus, we can conclude that men self-paced HIIE at higher APR but with the same cardiovascular/aerobic solicitation as women. Key points Men self-paced high-intensity intermittent exercise at higher intensities than women. Men utilized greater anaerobic power reserve than women. Men and women had same cardiovascular solicitation. PMID:27274678

IMPULSIVE ACCELERATION OF CORONAL MASS EJECTIONS. II. RELATION TO SOFT X-RAY FLARES AND FILAMENT ERUPTIONS

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

Bein, B. M.; Berkebile-Stoiser, S.; Veronig, A. M.

2012-08-10

Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak accelerations and lower acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive accelerations and originate from lower in the corona where the magnetic fieldmore » is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME acceleration duration and negatively correlated with the CME peak acceleration. For the majority of the events the CME acceleration starts before the flare onset (for 75% of the events) and the CME acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In {approx}60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME acceleration is smaller than {+-}5 minutes, which hints at a feedback relationship between the CME acceleration and the energy release in the associated flare due to magnetic reconnection.« less

Broadband terahertz dynamics of propylene glycol monomer and oligomers

NASA Astrophysics Data System (ADS)

Koda, Shota; Mori, Tatsuya; Kojima, Seiji

2016-12-01

We investigated the broadband terahertz spectra (0.1-5.0 THz) of glass-forming liquids, propylene glycol (PG), its oligomers poly (propylene glycol)s (PPGs), and poly (propylene glycol) diglycidyl ether (PPG-de) using broadband terahertz time-domain spectroscopy and low-frequency Raman scattering. The numerical value of the dielectric loss at around 1.5 THz, which is the peak position of broad peaks in all samples, decreased as the molecular weight increased. Furthermore, the peak at around 1.5 THz is insensitive to the molecular weight. For PPGs, the side chain effect of the oligomer was observed in the terahertz region. Based on the experimental and calculation results for the PPGs and PPG-de, whose end groups are epoxy groups, the beginnings of the increases in the observed dielectric loss above 3.5 THz of the PPGs are assigned to the OH bending vibration. The higher value of the dielectric loss in the terahertz region for the PPG-de can be the tail of a broad peak located in the MHz region. The difference between the Raman susceptibility and dielectric loss reflects the difference in the observable molecular dynamics between the infrared and Raman spectroscopies.

Optically Tuned MM-Wave IMPATT Source.

DTIC Science & Technology

1987-07-01

phase of the work has been extended and generalised. Accuracy of the theory in predicting tuning at the higher oscillator voltage swings has been greatly...Accuracy of the theory in predicting tuning at the higher oscillator voltage swings has been greatly improved by reformulating the Bessel function...voltage modulation and a peak optically injected locking current of 100 pA the predicted ftl locking range would be 540MHz, a practicaUy useful value. 4

Predictive Regression Equations of Flowmetric and Spirometric Peak Expiratory Flow in Healthy Moroccan Children.

PubMed

Bouti, Khalid; Benamor, Jouda; Bourkadi, Jamal Eddine

2017-08-01

Peak Expiratory Flow (PEF) has never been characterised among healthy Moroccan school children. To study the relationship between PEF and anthropometric parameters (sex, age, height and weight) in healthy Moroccan school children, to establish predictive equations of PEF; and to compare flowmetric and spirometric PEF with Forced Expiratory Volume in 1 second (FEV1). This cross-sectional study was conducted between April, 2016 and May, 2016. It involved 222 (122 boys and 100 girls) healthy school children living in Ksar el-Kebir, Morocco. We used mobile equipments for realisation of spirometry and peak expiratory flow measurements. SPSS (Version 22.0) was used to calculate Student's t-test, Pearson's correlation coefficient and linear regression. Significant linear correlation was seen between PEF, age and height in boys and girls. The equation for prediction of flowmetric PEF in boys was calculated as 'F-PEF = -187+ 24.4 Age + 1.61 Height' (p-value<0.001, r=0.86), and for girls as 'F-PEF = -151 + 17Age + 1.59Height' (p-value<0.001, r=0.86). The equation for prediction of spirometric PEF in boys was calculated as 'S-PEF = -199+ 9.8Age + 2.67Height' (p-value<0.05, r=0.77), and for girls as 'S-PEF = -181 + 8.5Age + 2.5Height' (p-value<0.001, r=0.83). The boys had higher values than the girls. The performance of the Mini Wright Peak Flow Meter was lower than that of a spirometer. Our study established PEF predictive equations in Moroccan children. Our results appeared to be reliable, as evident by the high correlation coefficient in this sample. PEF can be an alternative of FEV1 in centers without spirometry.

Comparison of early myocardial technetium-99m pyrophosphate uptake to early peaking of creatine kinase and creatine kinase-MB as indicators of early reperfusion in acute myocardial infarction

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

Kondo, M.; Yuzuki, Y.; Arai, H.

1987-10-01

The value of technetium-99m pyrophosphate (Tc-99m-PYP) scintigraphy as an indicator of reperfusion 2.8 to 8 hours after the onset of symptoms of acute myocardial infarction was compared with the value of early peak creatine kinase (CK) and CK-MB release within 16 hours after the onset of symptoms. In 29 patients who received thrombolytic therapy, recanalization was seen (group 1) and in 7 it was not (group 2). In 23 patients (79%) in group 1 scintigraphic findings were positive and in all 7 in group 2 they were negative. In 15 patients (52%) in group 1 and 1 patient (14%) inmore » group 2, CK reached its peak level within 16 hours. In 20 patients (69%) in group 1 and 3 (43%) in group 2 the CK-MB level reached a peak within 16 hours. The sensitivity, specificity and predictive accuracy of positive results of early Tc-99m-PYP scintigraphy in predicting the reperfusion were 79%, 100% and 83%. These values are significantly higher than or similar to those of early peaking of CK and CK-MB release. In contrast to measurements of enzyme release, reperfusion data for Tc-99m-PYP scintigraphy are available immediately after thrombolytic therapy. Therefore, early Tc-99m-PYP scintigraphy (3 to 8 hours after onset of symptoms) is valuable as a noninvasive technique for early diagnosis of reperfusion.« less

Stress Analysis of Transcatheter Aortic Valve Leaflets Under Dynamic Loading: Effect of Reduced Tissue Thickness.

PubMed

Abbasi, Mostafa; Azadani, Ali N

2017-07-01

In order to accommodate transcatheter valves to miniaturized catheters, the leaflet thickness must be reduced to a value which is typically less than that of surgical bioprostheses. The study aim was to use finite-element simulations to determine the impact of the thickness reduction on stress and strain distribution. A 23 mm transcatheter aortic valve (TAV) was modelled based on the Edwards SAPIEN XT (Edwards Lifesciences, Irvine, CA, USA). Finite-element (FE) analysis was performed using the ABAQUS/Explicit solver. An ensemble-averaged transvalvular pressure waveform measured from in-vitro tests conducted in a pulse duplicator was applied to the leaflets. Through a parametric study, uniform TAV leaflet thickness was reduced from 0.5 to 0.18 mm. By reducing leaflet thickness, significantly higher stress values were found in the leaflet's fixed edge during systole, and in the commissures during diastole. Through dynamic FE simulations, the highest stress values were found during systole in the leaflet fixed edge. In contrast, at the peak of diastole high-stress regions were mainly observed in the commissures. The peak stress was increased by 178% and 507% within the leaflets after reducing the thickness of 0.5 mm to 0.18 mm at the peak of systole and diastole, respectively. The study results indicated that, the smaller the leaflet thickness, the higher the maximum principal stress. Increased mechanical stress on TAV leaflets may lead to accelerated tissue degeneration. By using a thinner leaflet, TAV durability may not atch with that of surgical bioprostheses.

Relation Between Flow and Dissolved Oxygen in the Roanoke River Between Roanoke Rapids and Jamesville, North Carolina, 1998-2005

USGS Publications Warehouse

Wehmeyer, Loren L.; Bales, Jerad D.

2009-01-01

Understanding the relation between dam release characteristics and downstream water quality in the lower Roanoke River, North Carolina, is important for natural-resource management and ecosystem protection. Data from four raingages, four water-quality monitoring sites, and one streamflow-measurement site were used to identify statistical relations and discernible quantitative or qualitative patterns linking Roanoke River instream dissolved-oxygen (DO) levels to releases at Roanoke Rapids Dam for the period 1998-2005. The time-series DO data, complicated by the occurrence of major hurricanes in the short period of hourly DO data collection at the dam, present a mixed picture of the effects of hydropower peaking (a technique used by hydropower dam operators to produce electricity when consumption is high by passing a large volume of water through the dam turbines, which dramatically increases the volume of flow below the dam) on downstream DO. Other than in 2003 when dissolved-oxygen concentrations in the Roanoke River were likely affected by runoff from Hurricane Isabel rains, there were not consistent, statistically significant differences detected in the annual medians of hourly and(or) daily DO values during peaking versus nonpeaking periods. Along the Roanoke River, downstream of Roanoke Rapids Dam at Oak City, North Carolina, using a 95-percent confidence interval, the median value of the May-November daily mean DO concentrations for each year was lower during peaking periods for 2 years, higher for 2 years, and not significantly different for 4 years. Downstream at Jamesville, North Carolina, also using a 95-percent confidence interval, the median value of the annual May-November daily mean DO concentrations during hydropower peaking was lower for 4 years, higher for 2 years, and not significantly different for 2 years. In summary, the effect of hydropower peaking on downstream DO was inconsistent. Conversely, large precipitation events downstream from the dam resulted in consistent, statistically significant decreases in DO in the mainstem of the Roanoke River at Oak City and Jamesville.

[Atmospheric correction of visible-infrared band FY-3A/MERSI data based on 6S model].

PubMed

Wu, Yong-Li; Luan, Qing; Tian, Guo-Zhen

2011-06-01

Based on the observation data from the meteorological stations in Taiyuan City and its surrounding areas of Shanxi Province, the atmosphere parameters for 6S model were supplied, and the atmospheric correction of visible-infrared band (precision 250 meters) FY-3A/MERSI data was conducted. After atmospheric correction, the range of visible-infrared band FY-3A/MERSI data was widened, reflectivity increased, high peak was higher, and distribution histogram was smoother. In the meantime, the threshold value of NDVI data reflecting vegetation condition increased, and its high peak was higher, more close to the real data. Moreover, the color synthesis image of correction data showed more abundant information, its brightness increased, contrast enhanced, and the information reflected was more close to real.

Comparison of Lower Limb Segments Kinematics in a Taekwondo Kick. An Approach to the Proximal to Distal Motion

PubMed Central

Estevan, Isaac; Falco, Coral; Silvernail, Julia Freedman; Jandacka, Daniel

2015-01-01

In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane) of lower limb segments (thigh, shank and foot), and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years) participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane) than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values), with the distal segment taking the longest to reach this peak velocity (p < 0.01). Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01). It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern. PMID:26557189

Comparison of Lower Limb Segments Kinematics in a Taekwondo Kick. An Approach to the Proximal to Distal Motion.

PubMed

Estevan, Isaac; Falco, Coral; Silvernail, Julia Freedman; Jandacka, Daniel

2015-09-29

In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane) of lower limb segments (thigh, shank and foot), and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years) participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane) than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values), with the distal segment taking the longest to reach this peak velocity (p < 0.01). Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01). It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern.

A calculation and uncertainty evaluation method for the effective area of a piston rod used in quasi-static pressure calibration

NASA Astrophysics Data System (ADS)

Gu, Tingwei; Kong, Deren; Shang, Fei; Chen, Jing

2018-04-01

This paper describes the merits and demerits of different sensors for measuring propellant gas pressure, the applicable range of the frequently used dynamic pressure calibration methods, and the working principle of absolute quasi-static pressure calibration based on the drop-weight device. The main factors affecting the accuracy of pressure calibration are analyzed from two aspects of the force sensor and the piston area. To calculate the effective area of the piston rod and evaluate the uncertainty between the force sensor and the corresponding peak pressure in the absolute quasi-static pressure calibration process, a method for solving these problems based on the least squares principle is proposed. According to the relevant quasi-static pressure calibration experimental data, the least squares fitting model between the peak force and the peak pressure, and the effective area of the piston rod and its measurement uncertainty, are obtained. The fitting model is tested by an additional group of experiments, and the peak pressure obtained by the existing high-precision comparison calibration method is taken as the reference value. The test results show that the peak pressure obtained by the least squares fitting model is closer to the reference value than the one directly calculated by the cross-sectional area of the piston rod. When the peak pressure is higher than 150 MPa, the percentage difference is less than 0.71%, which can meet the requirements of practical application.

Normative reference values for the 20 m shuttle-run test in a population-based sample of school-aged youth in Bogota, Colombia: the FUPRECOL study.

PubMed

Ramírez-Vélez, Robinson; Palacios-López, Adalberto; Humberto Prieto-Benavides, Daniel; Enrique Correa-Bautista, Jorge; Izquierdo, Mikel; Alonso-Martínez, Alicia; Lobelo, Felipe

2017-01-01

Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio-metabolic risk. A total of 7244 children and adolescents attending public schools in Bogota, Colombia (55.7% girls; age range of 9-17.9 years) participated in this study. We expressed CRF performance as the nearest stage (minute) completed and the estimated peak oxygen consumption (V˙O 2peak ). Smoothed percentile curves were calculated. In addition, we present the prevalence of low CRF after applying a correction factor to account for the impact of Bogota's altitude (2625 m over sea level) on CRF assessment, and we calculated the number of participants who fell below health-related FITNESSGRAM cut-points for low CRF. Shuttles and V˙O 2peak were higher in boys than in girls in all age groups. In boys, there were higher levels of performance with increasing age, with most gains between the ages of 13 and 17. The proportion of subjects with a low CRF, suggestive of future cardio-metabolic risk (health risk FITNESSGRAM category) was 31.5% (28.2% for boys and 34.1% for girls; X 2 P = .001). After applying a 1.11 altitude correction factor, the overall prevalence of low CRF was 11.5% (9.6% for boys and 13.1% for girls; X 2 P = .001). Our results provide sex- and age-specific normative reference standards for the 20 m shuttle-run test and estimated V˙O 2peak values in a large, population-based sample of schoolchildren from a large Latin-American city at high altitude. © 2016 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.

Prognostic value of metabolic metrics extracted from baseline PET images in NSCLC

PubMed Central

Carvalho, Sara; Leijenaar, Ralph T.H.; Velazquez, Emmanuel Rios; Oberije, Cary; Parmar, Chintan; van Elmpt, Wouter; Reymen, Bart; Troost, Esther G.C.; Oellers, Michel; Dekker, Andre; Gillies, Robert; Aerts, Hugo J.W.L.; Lambin, Philippe

2015-01-01

Background Maximum, mean and peak SUV of primary tumor at baseline FDG-PET scans, have often been found predictive for overall survival in non-small cell lung cancer (NSCLC) patients. In this study we further investigated the prognostic power of advanced metabolic metrics derived from Intensity-Volume Histograms (IVH) extracted from PET imaging. Methods A cohort of 220 NSCLC patients (mean age, 66.6 years; 149 men, 71 women), stages I-IIIB, treated with radiotherapy with curative intent were included (NCT00522639). Each patient underwent standardized pre-treatment CT-PET imaging. Primary GTV was delineated by an experienced radiation oncologist on CT-PET images. Common PET descriptors such as maximum, mean and peak SUV, and metabolic tumor volume (MTV) were quantified. Advanced descriptors of metabolic activity were quantified by IVH. These comprised 5 groups of features: Absolute and Relative Volume above Relative Intensity threshold (AVRI and RVRI), Absolute and Relative Volume above Absolute Intensity threshold (AVAI and RVAI), and Absolute Intensity above Relative Volume threshold (AIRV). MTV was derived from the IVH curves for volumes with SUV above 2.5, 3 and 4, and of 40% and 50% maximum SUV. Univariable analysis using Cox Proportional Hazard Regression was performed for overall survival assessment. Results Relative volume above higher SUV (80 %) was an independent predictor of OS (p = 0.05). None of the possible surrogates for MTV based on volumes above SUV of 3, 40% and 50% of maximum SUV showed significant associations with OS (p (AVAI3) = 0.10, p (AVAI4) = 0.22, p (AVRI40%) = 0.15, p (AVRI50%) = 0.17). Maximum and peak SUV (r = 0.99) revealed no prognostic value for OS (p (maximum SUV) = 0.20, p (peak SUV) = 0.22). Conclusions New methods using more advanced imaging features extracted from PET were analyzed. Best prognostic value for OS of NSCLC patients was found for relative portions of the tumor above higher uptakes (80% SUV). PMID:24047338

Variability in Laboratory vs. Field Testing of Peak Power, Torque, and Time of Peak Power Production Among Elite Bicycle Motocross Cyclists.

PubMed

Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

2015-09-01

The aim of this study was to ascertain the variation in elite male bicycle motocross (BMX) cyclists' peak power, torque, and time of power production during laboratory and field-based testing. Eight elite male BMX riders volunteered for the study, and each rider completed 3 maximal sprints using both a Schoberer Rad Messtechnik (SRM) ergometer in the laboratory and a portable SRM power meter on an Olympic standard indoor BMX track. The results revealed a significantly higher peak power (p ≤ 0.001, 34 ± 9%) and reduced time of power production (p ≤ 0.001, 105 ± 24%) in the field tests when compared with laboratory-derived values. Torque was also reported to be lower in the laboratory tests but not to an accepted level of significance (p = 0.182, 6 ± 8%). These results suggest that field-based testing may be a more effective and accurate measure of a BMX rider's peak power, torque, and time of power production.

The Application of Quality Identification in Honey by Photoacoustic Spectroscopy.

PubMed

Tao, Wen-ting; Yuan, Ping; Guo, Wen-juan; Liu, Jian-en

2015-05-01

The photoacoustic spectrum of glucose, sucrose and honey solutions in the visible range are measured by using the single-light photoacoustic spectrometer, and are compared with the spectra from spedtrophotometry method. The spectral characteristics of the above solutions show that the spectral background intensity and spectral profile have some differences for different kinds of solutions. The spectra of the three kinds of solutions all have strong peak value at 485 and 655 nm, but the intensity ratios between the two peaks are different. Besides, there are characteristic peak at 475, 576 and 630 nm for glucose, and the sucrose has apparent characteristic peak at 632 nm, these characteristic peaks can be used for detecting whether the natural honey has been added glucose or sucrose. By comparing two kinds of spectrum of the same solution, the intensity of photoacoustic spectrum is more responsive to the wavelength, indicating photoacoustic spectrometry has a higher sensitivity in the test of material composition.

Characterization of detonation soot produced during steady and overdriven conditions for three high explosive formulations

NASA Astrophysics Data System (ADS)

Podlesak, David W.; Huber, Rachel C.; Amato, Ronald S.; Dattelbaum, Dana M.; Firestone, Millicent A.; Gustavsen, Richard L.; Johnson, Carl E.; Mang, Joseph T.; Ringstrand, Bryan S.

2017-01-01

The detonation of high explosives (HE) produces a dense fluid of molecular gases and solid carbon. The solid detonation carbon contains various carbon allotropes such as detonation nanodiamonds, onion-like carbon, graphite and amorphous carbon, with the formation of the different forms dependent upon pressure, temperature and the environmental conditions of the detonation. We have collected solid carbon residues from controlled detonations of three HE formulations (Composition B-3, PBX 9501, and PBX 9502). Soot was collected from experiments designed to produce both steady and overdriven conditions, and from detonations in both an ambient (air) atmosphere and in an inert Ar atmosphere. Differences in solid carbon residues were quantified using X-ray photoelectron spectroscopy and carbon isotope measurements. Environmental conditions, HE formulation, and peak pressures influenced the amount of and isotopic composition of the carbon in the soot. Detonations in an Ar atmosphere produced greater amounts of carbon soot with lower δ13C values than those in ambient air. Therefore, solid carbon residues continued to evolve after detonation due to excess oxygen in the ambient air detonations. As well, higher peak pressures in overdriven conditions produced less carbon soot with, in general, higher δ13C values. Consequently, while overdriven conditions only produced peak pressures for a limited duration, it was enough to influence the composition of the solid carbon residues.

Measuring saccade peak velocity using a low-frequency sampling rate of 50 Hz.

PubMed

Wierts, Roel; Janssen, Maurice J A; Kingma, Herman

2008-12-01

During the last decades, small head-mounted video eye trackers have been developed in order to record eye movements. Real-time systems-with a low sampling frequency of 50/60 Hz-are used for clinical vestibular practice, but are generally considered not to be suited for measuring fast eye movements. In this paper, it is shown that saccadic eye movements, having an amplitude of at least 5 degrees, can, in good approximation, be considered to be bandwidth limited up to a frequency of 25-30 Hz. Using the Nyquist theorem to reconstruct saccadic eye movement signals at higher temporal resolutions, it is shown that accurate values for saccade peak velocities, recorded at 50 Hz, can be obtained, but saccade peak accelerations and decelerations cannot. In conclusion, video eye trackers sampling at 50/60 Hz are appropriate for detecting the clinical relevant saccade peak velocities in contrast to what has been stated up till now.

Cardiopulmonary Response to Exercise Testing in People with Chronic Stroke: A Retrospective Study

PubMed Central

Billinger, Sandra A.; Taylor, Jordan M.; Quaney, Barbara M.

2012-01-01

Background and Purpose. This study investigated the cardiopulmonary response and safety of exercise testing at peak effort in people during the chronic stage of stroke recovery. Methods. This retrospective study examined data from 62 individuals with chronic stroke (males: 32; mean (SD); age: (12.0) yr) participating in an exercise test. Results. Both males and females had low cardiorespiratory fitness levels. No significant differences were found between gender for peak HR (P = 0.27), or VO2 peak (P = 0.29). Males demonstrated higher values for minute ventilation, tidal volume, and respiratory exchange ratio. No major adverse events were observed in the exercise tests conducted. Discussion and Conclusion. There are differences between gender that may play a role in exercise testing performance and should be considered when developing exercise programs. The low VO2 peak of this cohort of chronic stroke survivors suggests the need for participation in exercise interventions. PMID:21961083

Analysis of normal and diseased liver tissue using auto-fluorescence and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Li, Xiaozhou; Jia, Chunde; Lin, Junxiu; Kang, Youping

2003-12-01

In this paper, laser induced human serum Raman spectra of liver cancer are measured. The spectra differences in serum from normal people and liver cancer patients are analyzed. For the typical spectrum of normal serum, there are three sharp Raman peaks and relative intensity of Raman peaks excited by 514.5 nm is higher than that excited by 488.0 nm. However, for the Raman spectrum of liver cancer serum there are no peaks or very weak Raman peaks at the same positions. Results from more than two hundred case measurements show that clinical diagnostic accuracy is 92.86%. And then, the liver fibrosis and liver cirrhosis are studied applying the technology of LIF. To liver cirrhosis, the shape of Raman peak is similar to normal and fluorescence spectrum is similar to that of liver cancer from statistic data. The experiment indicates that there is notable fluorescence difference between the abnormal and normal liver tissue and have blue shift in fluorescence peak. These results have important reference values to explore the method of laser spectrum diagnosis.

Local strain-induced band gap fluctuations and exciton localization in aged WS2 monolayers

NASA Astrophysics Data System (ADS)

Krustok, J.; Kaupmees, R.; Jaaniso, R.; Kiisk, V.; Sildos, I.; Li, B.; Gong, Y.

2017-06-01

Optical properties of aged WS2 monolayers grown by CVD method on Si/SiO2 substrates are studied using temperature dependent photoluminescence and reflectance contrast spectroscopy. Aged WS2 monolayers have a typical surface roughness about 0.5 nm and, in addition, a high density of nanoparticles (nanocaps) with the base diameter about 30 nm and average height of 7 nm. The A-exciton of aged monolayer has a peak position at 1.951 eV while in as-grown monolayer the peak is at about 24 meV higher energy at room temperature. This red-shift is explained using local tensile strain concept, where strain value of 2.1% was calculated for these nanocap regions. Strained nanocaps have lower band gap energy and excitons will funnel into these regions. At T=10K a double exciton and trion peaks were revealed. The separation between double peaks is about 20 meV and the origin of higher energy peaks is related to the optical band gap energy fluctuations caused by random distribution of local tensile strain due to increased surface roughness. In addition, a wide defect related exciton band XD was found at about 1.93 eV in all aged monolayers. It is shown that the theory of localized excitons describes well the temperature dependence of peak position and halfwidth of the A-exciton band. The possible origin of nanocaps is also discussed.

Distinguishing oil and water layers in a cracked porous medium using pulsed neutron logging data based on Hudson's crack theory

NASA Astrophysics Data System (ADS)

Zhang, Xueang; Yang, Zhichao; Tang, Bin; Wang, Renbo; Wei, Xiong

2018-05-01

During geophysical surveys, water layers may interfere with the detection of oil layers. In order to distinguish between oil and water layers in porous cracked media, research on the properties of the cracks, the oil and water layers, and their relation to pulsed neutron logging characteristics is essential. Using Hudson's crack theory, we simulated oil and water layers in a cracked porous medium with different crack parameters corresponding to the well log responses. We found that, in a cracked medium with medium-angle (40°-50°) cracks, the thermal neutron count peak value is higher and more sensitive than those in low-angle and high-angle crack environments; in addition, the thermal neutron density distribution shows more minimum values than in other cases. Further, the thermal neutron count and the rate of change for the oil layer are greater than those of the water layer, and the time spectrum count peak value for the water layer in middle-high-angle (40°-70°) cracked environments is higher than that of the oil layer. The thermal neutron density distribution sensitivity is higher in the water layer with a range of small crack angles (0°-30°) than in the oil layer with the same range of angles. In comparing the thermal neutron density distribution, thermal neutron count peak, thermal neutron density distribution sensitivity, and time spectrum maximum in the oil and water layers, we find that neutrons in medium-angle (40°-50°) cracked reservoirs are more sensitive to deceleration and absorption than those in water layers; neutrons in approximately horizontal (0°-30°) cracked water layers are more sensitive to deceleration than those in reservoirs. These results can guide future work in the cracked media neutron logging field.

Strong ground motion from the November 12, 2017, M 7.3 Kermanshah earthquake in western Iran

NASA Astrophysics Data System (ADS)

Babaie Mahani, Alireza; Kazemian, Javad

2018-05-01

In this paper, we analyzed the strong ground motion from the November 12, 2017, Kermanshah earthquake in western Iran with moment magnitude (M) of 7.3. Nonlinear and linear amplification of ground motion amplitudes were observed at stations with soft soil condition at hypocentral distances below and above 100 km, respectively. Observation of large ground motion amplitudes dominated with long-period pulses on the strike-normal component of the velocity time series suggests a right-lateral component of movement and propagation of rupture towards southeast. Comparison of the horizontal peak ground acceleration (PGA) from the M 7.3 earthquake with global PGA values showed a similar decay in ground motion amplitudes, although it seems that PGA from the M 7.3 Kermanshah earthquake is higher than global values for NEHRP site class B. We also found that the bracketed duration (D b) was higher in the velocity domain than in the acceleration domain for the same modified Mercalli intensity (MMI) threshold. For example, D b reached 30 s at the maximum PGA while it was 50 s at the maximum peak ground velocity above the threshold of MMI = 5. Although the standard design spectrum from Iranian Code of Practice for Seismic Resistant Design of Buildings (standard No. 2800) seems to include appropriate values for the design of structures with fundamental period of 1 s and higher, it is underestimated for near-field ground motions at lower periods.

The utility of serum tryptase in the diagnosis of food-induced anaphylaxis.

PubMed

Wongkaewpothong, Patcharaporn; Pacharn, Punchama; Sripramong, Chaweewan; Boonchoo, Siribangon; Piboonpocanun, Surapon; Visitsunthorn, Nualanong; Vichyanond, Pakit; Jirapongsananuruk, Orathai

2014-07-01

This study investigates the utility of serum tryptase for the confirmation of shrimp-induced anaphylaxis. Patients with a history of shrimp allergy and positive skin prick tests (SPT) to commercial shrimp extract were recruited for shrimp challenges. Serum total tryptase was obtained at baseline and 60 min (peak) after the onset of symptoms. Thirty-nine patients were challenged. There were 12 patients with anaphylaxis, 20 with mild reactions and 7 without symptoms (control group). Characteristic features and baseline tryptase were not different among the 3 groups. The peak tryptase levels were higher than the baseline in anaphylaxis and mild reaction groups (P<0.05). The delta-tryptase (peak minus baseline) and the tryptase ratio (peak divided by baseline) in the anaphylaxis group were higher than the mild reaction and control groups (P<0.01). The optimum cut-off for peak tryptase to confirm anaphylaxis was 2.99 µg/L with 50% sensitivity, 85% specificity, 3.33 positive likelihood ratio (LR) and 0.59 negative LR. The manufacturer's cut-off for peak tryptase was >11.4 µg/L with 17% sensitivity, 100% specificity, infinity positive LR and 0.83 negative LR. The best cut-off for delta-tryptase was ≥0.8 µg/L with 83% sensitivity, 93% specificity, 11.86 positive LR and 0.18 negative LR. The best cut-off for tryptase ratio was ≥1.5 with 92% sensitivity, 96% specificity, 23 positive LR and 0.08 negative LR. The peak tryptase level should be compared with the baseline value to confirm anaphylaxis. The tryptase ratio provide the best sensitivity, specificity, positive and negative LR than a single peak serum tryptase for the confirmation of shrimp-induced anaphylaxis.

Oxygen consumption during functional electrical stimulation-assisted exercise in persons with spinal cord injury: implications for fitness and health.

PubMed

Hettinga, Dries M; Andrews, Brian J

2008-01-01

A lesion in the spinal cord leads in most cases to a significant reduction in active muscle mass, whereby the paralysed muscles cannot contribute to oxygen consumption (VO2) during exercise. Consequently, persons with spinal cord injury (SCI) can only achieve high VO2 values by excessively stressing the upper body musculature, which might increase the risk of musculoskeletal overuse injury. Alternatively, the muscle mass involved may be increased by using functional electrical stimulation (FES). FES-assisted cycling, FES-cycling combined with arm cranking (FES-hybrid exercise) and FES-rowing have all been suggested as candidates for cardiovascular training in SCI. In this article, we review the levels of VO2 (peak [VO2peak] and sub-peak [VO2sub-peak]) that have been reported for SCI subjects using these FES exercise modalities. A systematic literature search in MEDLINE, EMBASE, AMED, CINAHL, SportDiscus and the authors' own files revealed 35 studies that reported on 499 observations of VO2 levels achieved during FES-exercise in SCI. The results show that VO2peak during FES-rowing (1.98 L/min, n = 17; 24.1 mL/kg/min, n = 11) and FES-hybrid exercise (1.78 L/min, n = 67; 26.5 mL/kg/min, n = 35) is considerably higher than during FES-cycling (1.05 L/min, n = 264; 14.3 mL/kg/min, n = 171). VO2sub-peak values during FES-hybrid exercise were higher than during FES-cycling. FES-exercise training can produce large increases in VO2peak; the included studies report average increases of +11% after FES-rowing training, +12% after FES-hybrid exercise training and +28% after FES-cycling training. This review shows that VO2 during FES-rowing or FES-hybrid exercise is considerably higher than during FES-cycling. These observations are confirmed by a limited number of direct comparisons; larger studies to test the differences in effectiveness of the various types of FES-exercise as cardiovascular exercise are needed. The results to date suggest that FES-rowing and FES-hybrid are more suited for high-intensity, high-volume exercise training than FES-cycling. In able-bodied people, such exercise programmes have shown to result in superior health and fitness benefits. Future research should examine whether similar high-intensity and high-volume exercise programmes also give persons with SCI superior fitness and health benefits. This kind of research is very timely given the high incidence of physical inactivity-related health conditions in the aging SCI population.

The hydrological behaviour of extensive and intensive green roofs in a dry climate.

PubMed

Razzaghmanesh, M; Beecham, S

2014-11-15

This paper presents the results of a hydrological investigation of four medium scale green roofs that were set up at the University of South Australia. In this study, the potential of green roofs as a source control device was investigated over a 2 year period using four medium size green roof beds comprised of two growth media types and two media depths. During the term of this study, 226 rainfall events were recorded and these were representative of the Adelaide climate. In general, there were no statistically significant differences between the rainfall and runoff parameters for the intensive and extensive beds except for peak attenuation and peak runoff delay, for which higher values were recorded in the intensive beds. Longer dry periods generally resulted in higher retention coefficients and higher retention was also recorded in warmer seasons. The average retention coefficient for intensive systems (89%) was higher than for extensive systems (74%). It was shown that rainfall depth, intensity, duration and also average dry weather period between events can change the retention performance and runoff volume of the green roofs. Comparison of green and simulated conventional roofs indicated that the former were able to mitigate the peak of runoff and could delay the start of runoff. These characteristics are important for most source control measures. The recorded rainfall and runoff data displayed a non-linear relationship. Also, the results indicated that continuous time series modelling would be a more appropriate technique than using peak rainfall intensity methods for green roof design and simulation. Copyright © 2014 Elsevier B.V. All rights reserved.

Computational Aerothermodynamic Assessment of Space Shuttle Orbiter Tile Damage: Open Cavities

NASA Technical Reports Server (NTRS)

Pulsonetti, Maria; Wood, William

2005-01-01

Computational aerothermodynamic simulations of Orbiter windside tile damage in flight were performed in support of the Space Shuttle Return-to-Flight effort. The simulations were performed for both hypervelocity flight and low-enthalpy wind tunnel conditions and contributed to the Return-to-Flight program by providing information to support a variety of damage scenario analyses. Computations at flight conditions were performed at or very near the peak heating trajectory point for multiple damage scenarios involving damage windside acreage reaction cured glass (RCG) coated silica tile(s). The cavities formed by the missing tile examined in this study were relatively short leading to flow features which indicated open cavity behavior. Results of the computations indicated elevated heating bump factor levels predicted for flight over the predictions for wind tunnel conditions. The peak heating bump factors, defined as the local heating to a reference value upstream of the cavity, on the cavity floor for flight simulation were 67% larger than the peak wind tunnel simulation value. On the downstream face of the cavity the flight simulation values were 60% larger than the wind tunnel simulation values. On the outer mold line (OML) downstream of the cavity, the flight values are about 20% larger than the wind tunnel simulation values. The higher heating bump factors observed in the flight simulations were due to the larger driving potential in terms of energy entering the cavity for the flight simulations. This is evidenced by the larger rate of increase in the total enthalpy through the boundary layer prior to the cavity for the flight simulation.

Angular velocity affects trunk muscle strength and EMG activation during isokinetic axial rotation.

PubMed

Fan, Jian-Zhong; Liu, Xia; Ni, Guo-Xin

2014-01-01

To evaluate trunk muscle strength and EMG activation during isokinetic axial rotation at different angular velocities. Twenty-four healthy young men performed isokinetic axial rotation in right and left directions at 30, 60, and 120 degrees per second angular velocity. Simultaneously, surface EMG was recorded on external oblique (EO), internal oblique (IO), and latissimus dorsi (LD) bilaterally. In each direction, with the increase of angular velocity, peak torque decreased, whereas peak power increased. During isokinetic axial rotation, contralateral EO as well as ipsilateral IO and LD acted as primary agonists, whereas, ipsilateral EO as well as contralateral IO and LD acted as primary antagonistic muscles. For each primary agonist, the root mean square values decreased with the increase of angular velocity. Antagonist coactiviation was observed at each velocity; however, it appears to be higher with the increase of angular velocity. Our results suggest that velocity of rotation has great impact on the axial rotation torque and EMG activity. An inverse relationship of angular velocity was suggested with the axial rotation torque as well as root mean square value of individual trunk muscle. In addition, higher velocity is associated with higher coactivation of antagonist, leading to a decrease in torque with the increase of velocity.

Comparative Analysis of Peak Ground Acceleration Before and After Padang Earthquake 2009 Using Mc. Guirre Method

NASA Astrophysics Data System (ADS)

Ayu Rahmalia, Diah; Nilamprasasti, Hesti

2017-04-01

We have analyzed the earthquakes data in West Sumatra province to determine peak ground acceleration value. The peak ground acceleration is a parameter that describes the strength of the tremor that ever happened. This paper aims to compare the value of the peak ground acceleration by considering the b-value before and after the Padang earthquake 2009. This research was carried out in stages, starting by taking the earthquake data in West Sumatra province with boundary coordinates 0.923° LU - 2.811° LS and 97.075° - 102.261° BT, before and after the 2009 Padang earthquake with a magnitude ≥ 3 and depth of ≤ 300 km, calculation of the b-value, and ended by creating peak ground acceleration map based on Mc. Guirre empirical formula with Excel and Surfer software. Based on earthquake data from 2002 until before Padang earthquake 2009, the b-value is 0.874 while the b-value after the Padang earthquake in 2009 to 2016 is 0.891. Considering b value, it can be known that peak ground acceleration before and after the 2009 Padang earthquake might be different. Based on the seismic data before 2009, the peak ground acceleration value of West Sumatra province is ranged from 7,002 to 308.875 gal. This value will be compared by the value of the peak ground acceleration after the Padang earthquake in 2009 which ranged from 7,946 to 372,736 gal.

Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery.

PubMed

Devereaux, P J; Chan, Matthew T V; Alonso-Coello, Pablo; Walsh, Michael; Berwanger, Otavio; Villar, Juan Carlos; Wang, C Y; Garutti, R Ignacio; Jacka, Michael J; Sigamani, Alben; Srinathan, Sadeesh; Biccard, Bruce M; Chow, Clara K; Abraham, Valsa; Tiboni, Maria; Pettit, Shirley; Szczeklik, Wojciech; Lurati Buse, Giovanna; Botto, Fernando; Guyatt, Gordon; Heels-Ansdell, Diane; Sessler, Daniel I; Thorlund, Kristian; Garg, Amit X; Mrkobrada, Marko; Thomas, Sabu; Rodseth, Reitze N; Pearse, Rupert M; Thabane, Lehana; McQueen, Matthew J; VanHelder, Tomas; Bhandari, Mohit; Bosch, Jackie; Kurz, Andrea; Polanczyk, Carisi; Malaga, German; Nagele, Peter; Le Manach, Yannick; Leuwer, Martin; Yusuf, Salim

2012-06-06

Of the 200 million adults worldwide who undergo noncardiac surgery each year, more than 1 million will die within 30 days. To determine the relationship between the peak fourth-generation troponin T (TnT) measurement in the first 3 days after noncardiac surgery and 30-day mortality. A prospective, international cohort study that enrolled patients from August 6, 2007, to January 11, 2011. Eligible patients were aged 45 years and older and required at least an overnight hospital admission after having noncardiac surgery. Patients' TnT levels were measured 6 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We undertook Cox regression analysis in which the dependent variable was mortality until 30 days after surgery, and the independent variables included 24 preoperative variables. We repeated this analysis, adding the peak TnT measurement during the first 3 postoperative days as an independent variable and used a minimum P value approach to determine if there were TnT thresholds that independently altered patients' risk of death. A total of 15,133 patients were included in this study. The 30-day mortality rate was 1.9% (95% CI, 1.7%-2.1%). Multivariable analysis demonstrated that peak TnT values of at least 0.02 ng/mL, occurring in 11.6% of patients, were associated with higher 30-day mortality compared with the reference group (peak TnT ≤ 0.01 ng/mL): peak TnT of 0.02 ng/mL (adjusted hazard ratio [aHR], 2.41; 95% CI, 1.33-3.77); 0.03 to 0.29 ng/mL (aHR, 5.00; 95% CI, 3.72-6.76); and 0.30 ng/mL or greater (aHR, 10.48; 95% CI, 6.25-16.62). Patients with a peak TnT value of 0.01 ng/mL or less, 0.02, 0.03-0.29, and 0.30 or greater had 30-day mortality rates of 1.0%, 4.0%, 9.3%, and 16.9%, respectively. Peak TnT measurement added incremental prognostic value to discriminate those likely to die within 30 days for the model with peak TnT measurement vs without (C index = 0.85 vs 0.81; difference, 0.4; 95% CI, 0.2-0.5; P < .001 for difference between C index values). The net reclassification improvement with TnT was 25.0% (P < .001). Among patients undergoing noncardiac surgery, the peak postoperative TnT measurement during the first 3 days after surgery was significantly associated with 30-day mortality.

Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.

PubMed

Satoh, Takafumi; Kishi, Shintaro; Nagashima, Hisayuki; Tachikawa, Masumi; Kanamori-Kataoka, Mieko; Nakagawa, Takao; Kitagawa, Nobuyoshi; Tokita, Kenichi; Yamamoto, Soichiro; Seto, Yasuo

2015-03-20

The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman, tabun and nitrogen mustards were higher. Some CWA simulants and organic solvents gave the ion peaks eluting at the similar positions of the CWAs, resulting in false positive alarms. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis and evaluation of tasty components in the pileus and stipe of Lentinula edodes at different growth stages.

PubMed

Chen, Wanchao; Li, Wen; Yang, Yan; Yu, Hailong; Zhou, Shuai; Feng, Jie; Li, Xiaobei; Liu, Yanfang

2015-01-28

Tasty components in Lentinula edodes pileus and stipe at different growth stages were studied. Mannitol, trehalose, arabitol, and glucose were the main soluble polyols and sugars, whereas succinic acid, malic acid, and citric acid were the main organic acids. Mannitol contents were the highest in the pileus and increased at mature growth stages, although arabitol contents were the highest in the stipe and peaked at stage 5. Succinic acid contents peaked at stage 5 in the pileus and stipe during mature growth stages. Threonine (sweet taste) values were the highest among all the detected amino acids, followed by glutamic acid (MSG-like taste). MSG-like 5'-nucleotide contents could account for nearly 50% of the total 5'-nucleotides. Equivalent umami concentration (EUC) values of stage 5 exhibited higher levels during mature growth stages. Tasty components in the stipe were rich and EUC values were high, which might be useful for further processing and byproduct development of L. edodes.

Pilates improves lower limbs strength and postural control during quite standing in a child with hemiparetic cerebral palsy: A case report study.

PubMed

Dos Santos, Adriana Neves; Serikawa, Simoni Sayuri; Rocha, Nelci Adriana Cicuto Ferreira

2016-08-01

To verify the effect of Pilates exercises in a child with cerebral palsy (CP) with mild functional impairment. We evaluated average peak torque of ankle and knee extensors/flexors using a Biodex System, using concentric active-assisted test. We also evaluated amplitude of anterior-posterior and of medial-lateral displacement of the CoP and area of oscillation during quite standing with a BERTEC platform. We applied Pilates exercises for eight weeks. Peak torque/body weight of ankle and knee extensors/flexors of both affected and unaffected limbs increased after Pilates. Also, all kinetic variables decreased after Pilates' intervention. After one-month follow-up, isokinetic variable values were higher while kinetic variable values were lower than baseline values. Pilates may be an important rehabilitation technique for children with CP that present mild deficits in motor structures and high functional level, especially when the aims are to improve muscle strength and postural control during quite standing.

The reliability of vertical jump tests between the Vertec and My Jump phone application.

PubMed

Yingling, Vanessa R; Castro, Dimitri A; Duong, Justin T; Malpartida, Fiorella J; Usher, Justin R; O, Jenny

2018-01-01

The vertical jump is used to estimate sports performance capabilities and physical fitness in children, elderly, non-athletic and injured individuals. Different jump techniques and measurement tools are available to assess vertical jump height and peak power; however, their use is limited by access to laboratory settings, excessive cost and/or time constraints thus making these tools oftentimes unsuitable for field assessment. A popular field test uses the Vertec and the Sargent vertical jump with countermovement; however, new low cost, easy to use tools are becoming available, including the My Jump iOS mobile application (app). The purpose of this study was to assess the reliability of the My Jump relative to values obtained by the Vertec for the Sargent stand and reach vertical jump (VJ) test. One hundred and thirty-five healthy participants aged 18-39 years (94 males, 41 females) completed three maximal Sargent VJ with countermovement that were simultaneously measured using the Vertec and the My Jump . Jump heights were quantified for each jump and peak power was calculated using the Sayers equation. Four separate ICC estimates and their 95% confidence intervals were used to assess reliability. Two analyses (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, consistency, two-way mixed-effects model, while two others (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, absolute agreement, two-way mixed-effects model. Moderate to excellent reliability relative to the degree of consistency between the Vertec and My Jump values was found for jump height (ICC = 0.813; 95% CI [0.747-0.863]) and calculated peak power (ICC = 0.926; 95% CI [0.897-0.947]). However, poor to good reliability relative to absolute agreement for VJ height (ICC = 0.665; 95% CI [0.050-0.859]) and poor to excellent reliability relative to absolute agreement for peak power (ICC = 0.851; 95% CI [0.272-0.946]) between the Vertec and My Jump values were found; Vertec VJ height, and thus, Vertec calculated peak power values, were significantly higher than those calculated from My Jump values ( p < 0.0001). The My Jump app may provide a reliable measure of vertical jump height and calculated peak power in multiple field and laboratory settings without the need of costly equipment such as force plates or Vertec. The reliability relative to degree of consistency between the Vertec and My Jump app was moderate to excellent. However, the reliability relative to absolute agreement between Vertec and My Jump values contained significant variation (based on CI values), thus, it is recommended that either the My Jump or the Vertec be used to assess VJ height in repeated measures within subjects' designs; these measurement tools should not be considered interchangeable within subjects or in group measurement designs.

The reliability of vertical jump tests between the Vertec and My Jump phone application

PubMed Central

Castro, Dimitri A.; Duong, Justin T.; Malpartida, Fiorella J.; Usher, Justin R.; O, Jenny

2018-01-01

Background The vertical jump is used to estimate sports performance capabilities and physical fitness in children, elderly, non-athletic and injured individuals. Different jump techniques and measurement tools are available to assess vertical jump height and peak power; however, their use is limited by access to laboratory settings, excessive cost and/or time constraints thus making these tools oftentimes unsuitable for field assessment. A popular field test uses the Vertec and the Sargent vertical jump with countermovement; however, new low cost, easy to use tools are becoming available, including the My Jump iOS mobile application (app). The purpose of this study was to assess the reliability of the My Jump relative to values obtained by the Vertec for the Sargent stand and reach vertical jump (VJ) test. Methods One hundred and thirty-five healthy participants aged 18–39 years (94 males, 41 females) completed three maximal Sargent VJ with countermovement that were simultaneously measured using the Vertec and the My Jump. Jump heights were quantified for each jump and peak power was calculated using the Sayers equation. Four separate ICC estimates and their 95% confidence intervals were used to assess reliability. Two analyses (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, consistency, two-way mixed-effects model, while two others (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, absolute agreement, two-way mixed-effects model. Results Moderate to excellent reliability relative to the degree of consistency between the Vertec and My Jump values was found for jump height (ICC = 0.813; 95% CI [0.747–0.863]) and calculated peak power (ICC = 0.926; 95% CI [0.897–0.947]). However, poor to good reliability relative to absolute agreement for VJ height (ICC = 0.665; 95% CI [0.050–0.859]) and poor to excellent reliability relative to absolute agreement for peak power (ICC = 0.851; 95% CI [0.272–0.946]) between the Vertec and My Jump values were found; Vertec VJ height, and thus, Vertec calculated peak power values, were significantly higher than those calculated from My Jump values (p < 0.0001). Discussion The My Jump app may provide a reliable measure of vertical jump height and calculated peak power in multiple field and laboratory settings without the need of costly equipment such as force plates or Vertec. The reliability relative to degree of consistency between the Vertec and My Jump app was moderate to excellent. However, the reliability relative to absolute agreement between Vertec and My Jump values contained significant variation (based on CI values), thus, it is recommended that either the My Jump or the Vertec be used to assess VJ height in repeated measures within subjects’ designs; these measurement tools should not be considered interchangeable within subjects or in group measurement designs. PMID:29692955

Rhesus monkeys lack a consistent peak-end effect.

PubMed

Xu, Eric R; Knight, Emily J; Kralik, Jerald D

2011-12-01

In humans, the order of receiving sequential rewards can significantly influence the overall subjective utility of an outcome. For example, people subjectively rate receiving a large reward by itself significantly higher than receiving the same large reward followed by a smaller one (Do, Rupert, & Wolford, 2008). This result is called the peak-end effect. A comparative analysis of order effects can help determine the generality of such effects across primates, and we therefore examined the influence of reward-quality order on decision making in three rhesus macaque monkeys (Macaca mulatta). When given the choice between a high-low reward sequence and a low-high sequence, all three monkeys preferred receiving the high-value reward first. Follow-up experiments showed that for two of the three monkeys their choices depended specifically on reward-quality order and could not be accounted for by delay discounting. These results provide evidence for the influence of outcome order on decision making in rhesus monkeys. Unlike humans, who usually discount choices when a low-value reward comes last, rhesus monkeys show no such peak-end effect.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu(-)(cytidine) and Cu(-)(uridine).

PubMed

Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H; Guevara-García, Alfredo; Martínez, Ana

2011-02-07

The copper-nucleoside anions, Cu(-)(cytidine) and Cu(-)(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu(-)(cytidine) and Cu(-)(uridine), respectively. According to our calculations, Cu(-)(cytidine) and Cu(-)(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu(-)(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu-(cytidine) and Cu-(uridine)

NASA Astrophysics Data System (ADS)

Li, Xiang; Ko, Yeon-Jae; Wang, Haopeng; Bowen, Kit H.; Guevara-García, Alfredo; Martínez, Ana

2011-02-01

The copper-nucleoside anions, Cu-(cytidine) and Cu-(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu-(cytidine) and Cu-(uridine), respectively. According to our calculations, Cu-(cytidine) and Cu-(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostatic interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu-(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.

Relative Economic Merits of Storage and Combustion Turbines for Meeting Peak Capacity Requirements under Increased Penetration of Solar Photovoltaics

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

Denholm, Paul; Diakov, Victor; Margolis, Robert

Batteries with several hours of capacity provide an alternative to combustion turbines for meeting peak capacity requirements. Even when compared to state-of-the-art highly flexible combustion turbines, batteries can provide a greater operational value, which is reflected in a lower system-wide production cost. By shifting load and providing operating reserves, batteries can reduce the cost of operating the power system to a traditional electric utility. This added value means that, depending on battery life, batteries can have a higher cost than a combustion turbine of equal capacity and still produce a system with equal or lower overall life-cycle cost. For amore » utility considering investing in new capacity, the cost premium for batteries is highly sensitive to a variety of factors, including lifetime, natural gas costs, PV penetration, and grid generation mix. In addition, as PV penetration increases, the net electricity demand profile changes, which may reduce the amount of battery energy capacity needed to reliably meet peak demand.« less

Theoretical investigation of the SAW properties of ferroelectric film composite structures.

PubMed

Shih, W C; Wu, M S

1998-01-01

The characteristics of surface acoustic waves (SAW) propagating on a three-layered structure consisting of a perovskite-type ferroelectric film, a buffer layer and a semiconductor substrate have been studied theoretically. Large coupling coefficients (K(2)) can be obtained when the interdigital transducer (IDT) is on top of the perovskite-type ferroelectric film, with (type 4) and without (type 3) the floating-plane electrode at the perovskite-type ferroelectric film-buffer layer interface. In the above cases, the peak values of K (2) Of the Pb(Zr,Ti)O(3) (PZT) films (3.2%-3.8%) are higher than those of the BaTiO(3) (BT) and PbTiO(3) (PT) films. In the IDT configuration of type 4, there exists a minor peak of the coupling coefficients for the PZT and BT films, but not for the PT films when the normalized thickness (hK) of the perovskite-type ferroelectric film is about 0.3. The minor peak values of the coupling coefficients (0.62%-0.93%) for different layered structures (PZT/STO/Si, PZT/MgO/Si, and PZT/MgO/GaAs) all decrease when we increase hK value from 0 to 0.25. The results could be useful in the integration of ferroelectric devices, semiconductor devices, and SAW devices on the same substrate.

An improved peak frequency shift method for Q estimation based on generalized seismic wavelet function

NASA Astrophysics Data System (ADS)

Wang, Qian; Gao, Jinghuai

2018-02-01

As a powerful tool for hydrocarbon detection and reservoir characterization, the quality factor, Q, provides useful information in seismic data processing and interpretation. In this paper, we propose a novel method for Q estimation. The generalized seismic wavelet (GSW) function was introduced to fit the amplitude spectrum of seismic waveforms with two parameters: fractional value and reference frequency. Then we derive an analytical relation between the GSW function and the Q factor of the medium. When a seismic wave propagates through a viscoelastic medium, the GSW function can be employed to fit the amplitude spectrum of the source and attenuated wavelets, then the fractional values and reference frequencies can be evaluated numerically from the discrete Fourier spectrum. After calculating the peak frequency based on the obtained fractional value and reference frequency, the relationship between the GSW function and the Q factor can be built by the conventional peak frequency shift method. Synthetic tests indicate that our method can achieve higher accuracy and be more robust to random noise compared with existing methods. Furthermore, the proposed method is applicable to different types of source wavelet. Field data application also demonstrates the effectiveness of our method in seismic attenuation and the potential in the reservoir characteristic.

MODELING TIME DISPERSION DUE TO OPTICAL PATH LENGTH DIFFERENCES IN SCINTILLATION DETECTORS*

PubMed Central

Moses, W.W.; Choong, W.-S.; Derenzo, S.E.

2015-01-01

We characterize the nature of the time dispersion in scintillation detectors caused by path length differences of the scintillation photons as they travel from their generation point to the photodetector. Using Monte Carlo simulation, we find that the initial portion of the distribution (which is the only portion that affects the timing resolution) can usually be modeled by an exponential decay. The peak amplitude and decay time depend both on the geometry of the crystal, the position within the crystal that the scintillation light originates from, and the surface finish. In a rectangular parallelpiped LSO crystal with 3 mm × 3 mm cross section and polished surfaces, the decay time ranges from 10 ps (for interactions 1 mm from the photodetector) up to 80 ps (for interactions 50 mm from the photodetector). Over that same range of distances, the peak amplitude ranges from 100% (defined as the peak amplitude for interactions 1 mm from the photodetector) down to 4% for interactions 50 mm from the photodetector. Higher values for the decay time are obtained for rough surfaces, but the exact value depends on the simulation details. Estimates for the decay time and peak amplitude can be made for different cross section sizes via simple scaling arguments. PMID:25729464

Modeling Time Dispersion Due to Optical Path Length Differences in Scintillation Detectors

DOE PAGES

Moses, W. W.; Choong, W. -S.; Derenzo, S. E.

2014-08-20

In this paper, we characterize the nature of the time dispersion in scintillation detectors caused by path length differences of the scintillation photons as they travel from their generation point to the photodetector. Using Monte Carlo simulation, we find that the initial portion of the distribution (which is the only portion that affects the timing resolution) can usually be modeled by an exponential decay. The peak amplitude and decay time depend both on the geometry of the crystal, the position within the crystal that the scintillation light originates from, and the surface finish. In a rectangular parallelpiped LSO crystal withmore » 3 mm × 3 mm cross section and polished surfaces, the decay time ranges from 10 ps (for interactions 1 mm from the photodetector) up to 80 ps (for interactions 50 mm from the photodetector). Over that same range of distances, the peak amplitude ranges from 100% (defined as the peak amplitude for interactions 1 mm from the photodetector) down to 4% for interactions 50 mm from the photodetector. Higher values for the decay time are obtained for rough surfaces, but the exact value depends on the simulation details. Finally, estimates for the decay time and peak amplitude can be made for different cross section sizes via simple scaling arguments.« less

Single electron impact ionization of the methane molecule

NASA Astrophysics Data System (ADS)

Bouamoud, Mammar; Sahlaoui, Mohammed; Benmansour, Nour El Houda; Atomic and Molecular Collisions Team

2014-10-01

Triply differential cross sections (TDCS) results of electron-impact ionization of the inner 2a1 molecular orbital of CH4 are presented in the framework of the Second Born Approximation and compared with the experimental data performed in coplanar asymmetric geometry. The cross sections are averaged on the random orientations of the molecular target for accurate comparison with experiments and are compared also with the theoretical calculations of the Three Coulomb wave (3CW) model. Our results are in good agreement with experiments and 3CW results in the binary peak. In contrast the Second Born Approximation yields a significant higher values compared to the 3CW results for the recoil peak and seems to describe suitably the recoil region where higher order effects can occur with the participation of the recoiling ion in the collision process.

Radioactive status of seawater and its assessment in the northeast South China Sea and the Luzon Strait and its adjacent areas from 2011 to 2014.

PubMed

Zhou, Peng; Li, Dongmei; Zhao, Li; Li, Haitao; Zhao, Feng; Zheng, Yuanlai; Fang, Hongda; Lou, Quansheng; Cai, Weixu

2018-06-01

To understand the impact of the Fukushima nuclear accident (FNA), 137 Cs, 134 Cs, 90 Sr, and gross beta were analyzed in the northeast South China Sea (NSCS), the Luzon Strait (LS) and its adjacent areas. 137 Cs, 90 Sr, and gross beta values in the NSCS were similar to those prior to the FNA. 90 Sr and 137 Cs in the LS and its adjacent areas were consistent with those in the NSCS. The high 137 Cs-peak values occurred at depth of 150 m whereas the high 90 Sr-peak values occurred at depth of 0.5 m. The 137 Cs and gross beta mean values in Cruise I were higher than those in Cruise II whereas the 90 Sr mean value was just the reverse. 134 Cs in all seawater were below the minimum detectable activity. The past and present data since the 1970s suggested 137 Cs and 90 Sr in the study areas still originated from global fallout and the FNA influence were negligible. Copyright © 2018 Elsevier Ltd. All rights reserved.

3. A 40-years record of the polymetallic pollution of the Lot River system, France

NASA Astrophysics Data System (ADS)

Audry, S.; Schäfer, J.; Blanc, G.; Veschambre, S.; Jouanneau, J.-M.

2003-04-01

The Lot River system (southwest France) is known for historic Zn and Cd pollution that originates from Zn ore treatment in the small Riou-Mort watershed and affects seafood production in the Gironde Estuary. We present a sedimentary record from 2 cores taken in a dam lake downstream of the Riou-Mort watershed covering the evolution of metal inputs into the Lot River over the past 40 years (1960-2001). Depth profiles of Cd, Zn, Cu and Pb concentrations are comparable indicating common sources and transport. The constant Zn/Cd ratio (˜50) observed in the sediment cores is similar to that in SPM from the Riou-Mort watershed, indicating the dominance of point source pollution upon the geochemical background signal. Cadmium, Zn, Cu and Pb concentrations in the studied sediment cores show an important peak in 42-44 cm depth with up to 300 mg.kg-1 (Cd), 10,000 mg.kg-1 (Zn), 150 mg.kg-1 (Cu) and 930 mg.kg-1 (Pb). These concentrations are much higher than geochemical background values; For example, Cd concentrations are more than 350-fold higher than those measured in the same riverbed upstream the confluence with the Riou-Mort River. This peak coincides with the upper 137Cs peak resulting from the Chernobyl accident (1986). Therefore, this heavy metal peak is attributed to the latest accidental Cd pollution of the Lot-River in 1986. Several downward heavy metal peaks reflect varying input probably due to changes in industrial activities within the Riou-Mort watershed. Given mean sedimentation rate of about 2 cm.yr-1, the record suggests constant and much lower heavy metal concentrations since the early nineties due to restriction of industrial activities and remediation efforts in the Riou-Mort watershed. Nevertheless, Cd, Zn, Cu and Pb concentrations in the upper sediment remain high, compared to background values from reference sites in the upper Lot River system.

Normalization for peak oxygen uptake increases the prognostic power of the ventilatory response to exercise in patients with chronic heart failure.

PubMed

Guazzi, Marco; De Vita, Stefano; Cardano, Paola; Barlera, Simona; Guazzi, Maurizio D

2003-09-01

Peak exercise oxygen uptake (peak VO2) and ventilation to CO2 production (VE/VCO2) slope are established prognostic indicators in patients with chronic heart failure (CHF). A high VE/VCO2 slope, however, does not take into account the level of physical performance as expressed by peak VO2. We hypothesized that the prognostic value of a high VE/VCO2 slope may be improved by normalization for peak VO2 (VE/VCO2/VO2). One hundred patients with CHF underwent pulmonary function tests at rest (spirometry and lung diffusion capacity) and maximal cardiopulmonary exercise testing. The prognostic value of VE/VCO2 slope, peak VO2 and VE/VCO2/VO2 was probed prospectively. Twenty-one patients died from cardiac reasons during a mean follow-up of 26 +/- 19 months. Nonsurvivors, compared to survivors, showed a lower peak VO2 (13.6 +/- 4.0 vs 17.5 +/- 4.1 mL x min(-1) x kg(-1), P <.01) and a steeper VE/VCO2 slope (43 +/- 11 vs 31.6 +/- 5.0, P <.01). Nonetheless, in patients whose VE/VCO2 slope exceeded 34 (upper normal limit), there was no correlation with peak VO2 (r = -35, P = not significant). Interestingly 35% of them showed a normal exercise performance (peak VO2 > or =18 mL x min(-1) x kg(-1)). At multivariate analysis, the VE/VCO2 slope showed a prognostic power stronger than that of peak VO2; however, the VE/VCO2/VO2 index retained a prognostic power greater than that of both VE/VCO2 slope and peak VO2. A VE/VCO2/VO2 > or =2.4 signaled cases at higher risk. Discrepancies between VE/VCO2 slope and peak VO2 may generate uncertainty. Normalization of the former by the latter improves outcome prediction and may be considered a simple and effective way for maximizing the clinical applicability of these 2 indicators.

Estimates of Tibial Shock Magnitude in Men and Women at the Start and End of a Military Drill Training Program.

PubMed

Rice, Hannah M; Saunders, Samantha C; McGuire, Stephen J; O'Leary, Thomas J; Izard, Rachel M

2018-03-26

Foot drill is a key component of military training and is characterized by frequent heel stamping, likely resulting in high tibial shock magnitudes. Higher tibial shock during running has previously been associated with risk of lower limb stress fractures, which are prevalent among military populations. Quantification of tibial shock during drill training is, therefore, warranted. This study aimed to provide estimates of tibial shock during military drill in British Army Basic training. The study also aimed to compare values between men and women, and to identify any differences between the first and final sessions of training. Tibial accelerometers were secured on the right medial, distal shank of 10 British Army recruits (n = 5 men; n = 5 women) throughout a scheduled drill training session in week 1 and week 12 of basic military training. Peak positive accelerations, the average magnitude above given thresholds, and the rate at which each threshold was exceeded were quantified. Mean (SD) peak positive acceleration was 20.8 (2.2) g across all sessions, which is considerably higher than values typically observed during high impact physical activity. Magnitudes of tibial shock were higher in men than women, and higher in week 12 compared with week 1 of training. This study provides the first estimates of tibial shock magnitude during military drill training in the field. The high values suggest that military drill is a demanding activity and this should be considered when developing and evaluating military training programs. Further exploration is required to understand the response of the lower limb to military drill training and the etiology of these responses in the development of lower limb stress fractures.

Dynamics of deposited fly-ash and fine grained magnetite in sandy material of different porosity (column experiments)

NASA Astrophysics Data System (ADS)

Kapicka, Ales; Kodesova, Radka; Petrovsky, Eduard; Grison, Hana

2010-05-01

Several studies confirm that soil magnetometry can serve as proxy of industrial immisions as well as heavy-metal contamination. The important assumption for magnetic mapping of contaminated soils is that atmospherically deposited particulate matter, including the ferrimagnetic phase, accumulates in the top soil horizons and remains there over long period. Only if this is true, large areas can be reliably mapped using soil magnetometry, and, moreover, this method can be used also for long-term monitoring. However, in soil types such as sandy soils with different porosity or soils with substantial variability of water regime, translocation of the deposited anthropogenic particles may result in biased (underestimated) values of the measured topsoil magnetic susceptibility. From the physical point of view, this process may be considered as colloid transport through porous medium. In our column experiments in laboratory we used three technical sands with different particle sizes (0,63 - 1.25mm, 0,315-0,80mm, 0,10-0,63mm). Sands in cylinders were contaminated on the surface by fly-ashes from coal-burning power plant (mean grain size 10μm) and fine grained Fe3O4 (grain size < 20 μm). Soil moisture sensors were used to monitor water regime within the sand columns after controlled rain simulation and temperature distribution in sand column was measured as well. Vertical migration of ferrimagnetic particles-tracers presented in the fly-ash was measured by SM 400 Kappameter. By means of magnetic susceptibility distribution we studied two parameters: gradual shift of peak concentration of contaminants (relative to surface layer) and maximum penetration depth. Results indicated that after rain simulation (pulls infiltration of defined water volume) the positions of peak values moved downwards compared to the initial state and gradual decrease of susceptibility peak values were detected in all studied sand formations. Fly-ash migrated more or less freely in coarse sand material. In medium and fine sand the contaminants moved only to the depths of several cm due to the pore-space blocking and water flow decrease. Fine-grained magnetite shows different behavior. Position of peaks value is more or less stable and maximum depth of penetration is only a few cm in all cases. Higher grain size value is probably reason for higher stability of magnetite. Moreover, magnetic interaction between grains increase "effective" grain size value and restricts transport in material with given porosity. This research is supported by the Grant Agency ASCR under grant IAA300120701

Effect of altitude on spirometric parameters and the performance of peak flow meters.

PubMed Central

Pollard, A. J.; Mason, N. P.; Barry, P. W.; Pollard, R. C.; Collier, D. J.; Fraser, R. S.; Miller, M. R.; Milledge, J. S.

1996-01-01

BACKGROUND: Portable peak flow meters are used in clinical practice for measurement of peak expiratory flow (PEF) at many different altitudes throughout the world. Some PEF meters are affected by gas density. This study was undertaken to establish which type of meter is best for use above sea level and to determine changes in spirometric measurements at altitude. METHODS: The variable orifice mini-Wright peak flow meter was compared with the fixed orifice Micro Medical Microplus turbine microspirometer at sea level and at Everest Base Camp (5300 m). Fifty one members of the 1994 British Mount Everest Medical Expedition were studied (age range, 19-55). RESULTS: Mean forced vital capacity (FVC) fell by 5% and PEF rose by 25.5%. However, PEF recorded with the mini-Wright peak flow meter underestimated PEF by 31%, giving readings 6.6% below sea level values. FVC was lowest in the mornings and did not improve significantly with acclimatisation. Lower PEF values were observed on morning readings and were associated with higher acute mountain sickness scores, although the latter may reflect decreased effort in those with acute mountain sickness. There was no change in forced expiratory volume in one second (FEV1) at altitude when measured with the turbine microspirometer. CONCLUSIONS: The cause of the fall in FVC at 5300 m is unknown but may be attributed to changes in lung blood volume, interstitial lung oedema, or early airways closure. Variable orifice peak flow meters grossly underestimate PEF at altitude and fixed orifice devices are therefore preferable where accurate PEF measurements are required above sea level. PMID:8711651

Use of First-phase Insulin Secretion in Early Diagnosis of Thyroid Diabetes and Type 2 Diabetes Mellitus

PubMed Central

Meng, Li-Heng; Huang, Yao; Zhou, Jia; Liang, Xing-Huan; Xian, Jing; Li, Li; Qin, Ying-Fen

2017-01-01

Background: A relationship between hyperthyroidism and insulin secretion in type 2 diabetes mellitus (T2DM) has been reported. Therefore, this study explored the use of first-phase insulin secretion in the differential diagnosis of thyroid diabetes (TDM) and T2DM. Methods: In total, 101 patients with hyperthyroidism were divided into hyperthyroidism with normal glucose tolerance (TNGT), hyperthyroidism with impaired glucose regulation (TIGR), and diabetes (TDM) groups. Furthermore, 96 patients without hyperthyroidism were recruited as control groups (normal glucose tolerance [NGT], impaired glucose regulation [IGR], and T2DM). The following parameters were evaluated: homeostasis model assessment (HOMA)-IR, HOMA-β, modified β-cell function index (MBCI), peak insulin/fasting insulin (IP/I0), AUCins-OGTT, and AUCins-OGTT/AUCglu-OGTT from the oral glucose tolerance test (OGTT) insulin release test were utilized to assess the second-phase insulin secretion, while the IP/I0, AIR0′~10′, and AUCins-IVGTT from the intravenous glucose tolerance test (IVGTT) insulin release test were used to assess the first-phase insulin secretion. Results: In the OGTT, the HOMA-β values of the TNGT and TDM groups were higher than those of the NGT and T2DM groups (all P < 0.05). In the hyperthyroidism groups, the MBCI of the TDM group was lower than that of the TNGT and TIGR groups (all P < 0.05). Among the control groups, the MBCI values of the IGR and T2DM groups were lower than that of the normal glucose tolerance (NGT) group (all P < 0.05). In the IVGTT, insulin secretion peaked for all groups at 2–4 min, except for the T2DM group, which showed a low plateau and no secretion peak. The IP values of the TNGT, TIGR, and TDM groups were higher than those of the NGT, IGR, and T2DM groups (all P < 0.05). The Ip/I0, AIR0′~10′, and AUCins-IVGTT values of the TDM group were higher than those of the T2DM group but were lower than those of the TNGT, TIGR, NGR, and IGR groups (all P < 0.05). Compared with the other five groups, the Ip/I0, AIR0′~10′, and AUCins-IVGTT values of the T2DM group were significantly decreased (all P < 0.05). The Ip/I0 and AUCins-IVGTT values of the TNGT group were higher than those of the NGT group (all P < 0.05). Conclusions: β-cell function in TDM patients is superior to that in T2DM patients. First-phase insulin secretion could be used as an early diagnostic marker to differentiate TDM and T2DM. PMID:28345543

Nasal patency and otorhinolaryngologic-orofacial features in children.

PubMed

Milanesi, Jovana de Moura; Berwig, Luana Cristina; Schuch, Luiz Henrique; Ritzel, Rodrigo Agne; Silva, Ana Maria Toniolo da; Corrêa, Eliane Castilhos Rodrigues

2017-11-21

Nasal obstruction is a common symptom in childhood, related to rhinitis and pharyngeal tonsil hypertrophy. In the presence of nasal obstruction, nasal patency may be reduced, and nasal breathing is replaced by mouth breathing. Orofacial and otorhinolaryngologic changes are related to this breathing mode. Objective evaluation of upper airways may be obtained through nasal patency measurement. To compare nasal patency and otorhinolaryngologic-orofacial features in children. One hundred and twenty three children, 6-12 year-old, and of both sexes underwent speech therapy evaluation, according to Orofacial Myofunctional Evaluation protocol, clinical and endoscopic otorhinolaryngologic examination and nasal patency measurement, using the absolute and predicted (%) peak nasal inspiratory flow values. Lower values of absolute and estimated peak nasal inspiratory flow values were found in children with restless sleep (p=0.006 and p=0.002), nasal obstruction report (p=0.027 and p=0.023), runny nose (p=0.004 and p=0.012), unsystematic lip closure during mastication (p=0.040 and p=0.026), masticatory speed reduced (p=0.006 and p=0.008) and altered solid food swallowing (p=0.006 and p=0.001). Absolute peak nasal inspiratory flow was lower in children with pale inferior turbinate (p=0.040), reduced hard palate width (p=0.037) and altered speech (p=0.004). Higher absolute values were found in children with increased tongue width (p=0.027) and, higher absolute and predicted (%) in children with mild everted lip (p=0.008 and p=0.000). Nasal patency was lower in children with restless sleep, rhinitis signs and symptoms, hard palate width reduced and with changes in mastication, deglutition and speech functions. It is also emphasized that most of the children presented signs and symptom of allergic rhinitis. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

A novel fast phase correlation algorithm for peak wavelength detection of Fiber Bragg Grating sensors.

PubMed

Lamberti, A; Vanlanduit, S; De Pauw, B; Berghmans, F

2014-03-24

Fiber Bragg Gratings (FBGs) can be used as sensors for strain, temperature and pressure measurements. For this purpose, the ability to determine the Bragg peak wavelength with adequate wavelength resolution and accuracy is essential. However, conventional peak detection techniques, such as the maximum detection algorithm, can yield inaccurate and imprecise results, especially when the Signal to Noise Ratio (SNR) and the wavelength resolution are poor. Other techniques, such as the cross-correlation demodulation algorithm are more precise and accurate but require a considerable higher computational effort. To overcome these problems, we developed a novel fast phase correlation (FPC) peak detection algorithm, which computes the wavelength shift in the reflected spectrum of a FBG sensor. This paper analyzes the performance of the FPC algorithm for different values of the SNR and wavelength resolution. Using simulations and experiments, we compared the FPC with the maximum detection and cross-correlation algorithms. The FPC method demonstrated a detection precision and accuracy comparable with those of cross-correlation demodulation and considerably higher than those obtained with the maximum detection technique. Additionally, FPC showed to be about 50 times faster than the cross-correlation. It is therefore a promising tool for future implementation in real-time systems or in embedded hardware intended for FBG sensor interrogation.

Association between peak neutrophil count, clopidogrel loading dose, and left ventricular systolic function in patients with primary percutaneous coronary intervention.

PubMed

Wang, Xinyu; Yu, Haiyi; Li, Zhaoping; Li, Liuning; Zhang, Youyi; Gao, Wei

2014-01-01

Inflammation plays an important role in plaque development and left ventricular remodeling during acute myocardial infarction (AMI). Clopidogrel may exhibit some anti-inflammatory properties and high loading dose of clopidogrel results in improved clinical outcomes in patients with AMI. 357 patients who received successful primary percutaneous coronary intervention from January 2008 to March 2011 in Peking University Third Hospital were included in this study. Different loading dose of clopidogrel (300 mg, 450 mg, or 600 mg) was given at the discretion of the clinician. Neutrophils reached their peak values on the first day after AMI. Higher levels of peak neutrophil and lower left ventricular ejection fraction (LVEF) were found in patients of low clopidogrel loading dose group (300 mg or 450 mg). After adjusting for the related confounders, a logistic regression model showed that low clopidogrel loading dose remained an independent predictor of low LVEF (LVEF ≤ 50%) [OR: 1.97, 95% CI: 1.03-3.79, P = 0.04]. Low clopidogrel loading dose was associated with higher peak neutrophil count and poor left ventricular systolic function, suggesting an important role of clopidogrel loading dose in the improvement of left ventricular function and high loading dose may exhibit better anti-inflammatory properties.

Assessing Cost-effectiveness of Green Infrastructures in response to Large Storm Events at Household Scale

NASA Astrophysics Data System (ADS)

Chui, T. F. M.; Liu, X.; Zhan, W.

2015-12-01

Green infrastructures (GI) are becoming more important for urban stormwater control worldwide. However, relatively few studies focus on researching the specific designs of GI at household scale. This study assesses the hydrological performance and cost-effectiveness of different GI designs, namely green roofs, bioretention systems and porous pavements. It aims to generate generic insights by comparing the optimal designs of each GI in 2-year and 50-year storms of Hong Kong, China and Seattle, US. EPA SWMM is first used to simulate the hydrologic performance, in particular, the peak runoff reduction of thousands of GI designs. Then, life cycle costs of the designs are computed and their effectiveness, in terms of peak runoff reduction percentage per thousand dollars, is compared. The peak runoff reduction increases almost linearly with costs for green roofs. However, for bioretention systems and porous pavements, peak runoff reduction only increases significantly with costs in the mid values. For achieving the same peak runoff reduction percentage, the optimal soil depth of green roofs increases with the design storm, while surface area does not change significantly. On the other hand, for bioretention systems and porous pavements, the optimal surface area increases with the design storm, while thickness does not change significantly. In general, the cost effectiveness of porous pavements is highest, followed by bioretention systems and then green roofs. The cost effectiveness is higher for a smaller storm, and is thus higher for 2-year storm than 50-year storm, and is also higher for Seattle when compared to Hong Kong. This study allows us to better understand the hydrological performance and cost-effectiveness of different GI designs. It facilitates the implementation of optimal choice and design of each specific GI for stormwater mitigation.

Color-coded perfusion analysis of CEUS for pre-interventional diagnosis of microvascularisation in cases of vascular malformations.

PubMed

Teusch, V I; Wohlgemuth, W A; Piehler, A P; Jung, E M

2014-01-01

Aim of our pilot study was the application of a contrast-enhanced color-coded ultrasound perfusion analysis in patients with vascular malformations to quantify microcirculatory alterations. 28 patients (16 female, 12 male, mean age 24.9 years) with high flow (n = 6) or slow-flow (n = 22) malformations were analyzed before intervention. An experienced examiner performed a color-coded Doppler sonography (CCDS) and a Power Doppler as well as a contrast-enhanced ultrasound after intravenous bolus injection of 1 - 2.4 ml of a second-generation ultrasound contrast medium (SonoVue®, Bracco, Milan). The contrast-enhanced examination was documented as a cine sequence over 60 s. The quantitative analysis based on color-coded contrast-enhanced ultrasound (CEUS) images included percentage peak enhancement (%peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT). No side effects occurred after intravenous contrast injection. The mean %peak in arteriovenous malformations was almost twice as high as in slow-flow-malformations. The area under the curve was 4 times higher in arteriovenous malformations compared to the mean value of other malformations. The mean transit time was 1.4 times higher in high-flow-malformations compared to slow-flow-malformations. There was no difference regarding the time to peak between the different malformation types. The comparison between all vascular malformation and surrounding tissue showed statistically significant differences for all analyzed data (%peak, TTP, AUC, MTT; p < 0.01). High-flow and slow-flow vascular malformations had statistically significant differences in %peak (p < 0.01), AUC analysis (p < 0.01), and MTT (p < 0.05). Color-coded perfusion analysis of CEUS seems to be a promising technique for the dynamic assessment of microvasculature in vascular malformations.

Improved shear wave group velocity estimation method based on spatiotemporal peak and thresholding motion search

PubMed Central

Amador, Carolina; Chen, Shigao; Manduca, Armando; Greenleaf, James F.; Urban, Matthew W.

2017-01-01

Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges of liver shear wave velocities values for healthy individuals and patients with different stages of liver fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative ultrasound elastography measurements by assessing factors that influence tissue shear wave velocity values, such as food intake, body mass index (BMI), ultrasound scanners, scanning protocols, ultrasound image quality, etc. Time-to-peak (TTP) methods have been routinely used to measure the shear wave velocity. However, there is still a need for methods that can provide robust shear wave velocity estimation in the presence of noisy motion data. The conventional TTP algorithm is limited to searching for the maximum motion in time profiles at different spatial locations. In this study, two modified shear wave speed estimation algorithms are proposed. The first method searches for the maximum motion in both space and time (spatiotemporal peak, STP); the second method applies an amplitude filter (spatiotemporal thresholding, STTH) to select points with motion amplitude higher than a threshold for shear wave group velocity estimation. The two proposed methods (STP and STTH) showed higher precision in shear wave velocity estimates compared to TTP in phantom. Moreover, in a cohort of 14 healthy subjects STP and STTH methods improved both the shear wave velocity measurement precision and the success rate of the measurement compared to conventional TTP. PMID:28092532

Improved Shear Wave Group Velocity Estimation Method Based on Spatiotemporal Peak and Thresholding Motion Search.

PubMed

Amador Carrascal, Carolina; Chen, Shigao; Manduca, Armando; Greenleaf, James F; Urban, Matthew W

2017-04-01

Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges of liver shear wave velocity values for healthy individuals and patients with different stages of liver fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative ultrasound elastography measurements by assessing factors that influence tissue shear wave velocity values, such as food intake, body mass index, ultrasound scanners, scanning protocols, and ultrasound image quality. Time-to-peak (TTP) methods have been routinely used to measure the shear wave velocity. However, there is still a need for methods that can provide robust shear wave velocity estimation in the presence of noisy motion data. The conventional TTP algorithm is limited to searching for the maximum motion in time profiles at different spatial locations. In this paper, two modified shear wave speed estimation algorithms are proposed. The first method searches for the maximum motion in both space and time [spatiotemporal peak (STP)]; the second method applies an amplitude filter [spatiotemporal thresholding (STTH)] to select points with motion amplitude higher than a threshold for shear wave group velocity estimation. The two proposed methods (STP and STTH) showed higher precision in shear wave velocity estimates compared with TTP in phantom. Moreover, in a cohort of 14 healthy subjects, STP and STTH methods improved both the shear wave velocity measurement precision and the success rate of the measurement compared with conventional TTP.

[Effect of acetylation and oxidation on some properties of breadfruit (Artocarpus altilis) seed starch].

PubMed

Rincón, Alicia Mariela; Bou Rached, Lizet; Aragoza, Luis E; Padilla, Fanny

2007-09-01

Starch extracted from seeds of Artocarpus altilis (Breadfruit) was chemically modified by acetylation and oxidation, and its functional properties were evaluated and compared with these of native starch. Analysis of the chemical composition showed that moisture content was higher for modified starches. Ash, protein, crude fiber and amylose contents were reduced by the modifications, but did not alter the native starch granules' irregularity, oval shape and smooth surface. Acetylation produced changes in water absorption, swelling power and soluble solids, these values were higher for acetylated starch, while values for native and oxidized starches were similar. Both modifications reduced pasting temperature; oxidation reduced maximum peak viscosity but it was increased by acetylation. Hot paste viscosity was reduced by both modifications, whereas cold paste viscosity was lower in the oxidized starch and higher in the acetylated starch. Breakdown was increased by acetylation and reduced with oxidation. Setback value was reduced after acetylation, indicating it could minimize retrogradation of the starch.

Effect of horizontal pick and place locations on shoulder kinematics.

PubMed

Könemann, R; Bosch, T; Kingma, I; Van Dieën, J H; De Looze, M P

2015-01-01

In this study the effects of horizontal bin locations in an order picking workstation on upper arm elevation, trunk inclination and hand use were investigated. Eight subjects moved (self-paced) light or heavy products (0.2 and 3.0 kg) from a central product bin to an inner or outer order bin (at 60 or 150 cm) on the left or right side of the workstation, while movements were recorded. The outer compared to inner bin location resulted in more upper arm elevation and trunk inclination per work cycle, both in terms of number of peak values and in terms of time integrals of angles (which is a dose measure over time). Considering the peak values and time integrals per minute (instead of per work cycle), these effects are reduced, due to the higher cycle times for outer bins. Hand use (left, right or both) was not affected by order bin locations.

Magnetic resonance imaging evaluation of treatment efficacy and prognosis for brain metastases in lung cancer patients after radiotherapy: A preliminary study.

PubMed

Liu, Yuhui; Liu, Xibin; Xu, Liang; Liu, Liheng; Sun, Yuhong; Li, Minghuan; Zeng, Haiyan; Yuan, Shuanghu; Yu, Jinming

2018-05-17

This study used magnetic resonance imaging (MRI) to monitor changes to brain metastases and investigate the imaging signs used to evaluate treatment efficacy and determine prognosis following radiotherapy for brain metastases from lung cancer. A total of 60 non-small cell lung cancer patients with brain oligometastases were selected. MRI scans were conducted before and 3, 6, 9, 12, 18, 24, and 30 months after radiotherapy. The tumor and peritumoral edema diameters, Cho/Cr values, elevation of the Lip peak value, and whether the island (yu-yuan) sign or high-signal ring were present on T2 fluid-attenuated inversion recovery (FLAIR) imaging were recorded for each metastasis. The mortality risk was higher the earlier the maximum value of peritumoral edema diameter was reached, when there were fewer island signs, and when brain metastases did not present as tumor progression on imaging. There were significant differences in the average peritumoral edema diameter, apparent diffusion coefficient value, the number of elevated Lip peak values, and the number of T2 FLAIR imaging high-signal rings in a year after radiotherapy in 14 patients with a survival period < 1 year compared to patients with a survival period > 2 years. After radiotherapy for brain metastases, patients with the island sign had longer survival periods, high-signal rings in T2 FLAIR, elevated Lip peaks, and reduced apparent diffusion coefficient values, indicating tumor necrosis. Increased diameter of metastases and Cho/Cr > 2 cannot serve as reliable indicators of brain metastasis progression. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Experimental investigation of the 100 keV X-ray dose response of the high-temperature thermoluminescence in LiF:Mg,Ti (TLD-100): theoretical interpretation using the unified interaction model.

PubMed

Livingstone, J; Horowitz, Y S; Oster, L; Datz, H; Lerch, M; Rosenfeld, A; Horowitz, A

2010-03-01

The dose response of LiF:Mg,Ti (TLD-100) chips was measured from 1 to 50,000 Gy using 100 keV X rays at the European Synchroton Radiation Facility. Glow curves were deconvoluted into component glow peaks using a computerised glow curve deconvolution (CGCD) code based on first-order kinetics. The normalised dose response, f(D), of glow peaks 4 and 5 and 5b (the major components of composite peak 5), as well as peaks 7 and 8 (two of the major components of the high-temperature thermoluminescence (HTTL) at high levels of dose) was separately determined and theoretically interpreted using the unified interaction model (UNIM). The UNIM is a nine-parameter model encompassing both the irradiation/absorption stage and the thermally induced relaxation/recombination stage with an admixture of both localised and delocalised recombination mechanisms. The effects of radiation damage are included in the present modelling via the exponential removal of luminescent centres (LCs) at high dose levels. The main features of the experimentally measured dose response are: (i) increase in f(D)(max) with glow peak temperature, (ii) increase in D(max) (the dose level at which f(D)(max) occurs) with increasing glow peak temperature, and (iii) decreased effects of radiation damage with increasing glow peak temperature. The UNIM interpretation of this behaviour requires both strongly decreasing values of ks (the relative contribution of localised recombination) as a function of glow peak temperature and, as well, significantly different values of the dose-filling constants of the trapping centre (TC) and LC for peaks 7 and 8 than those used for peaks 4 and 5. This suggests that different TC/LC configurations are responsible for HTTL. The relative intensity of peak 5a (a low-temperature satellite of peak 5 arising from localised recombination) was found to significantly increase at higher dose levels due to preferential electron and hole population of the trapping/recombination complex giving rise to composite glow peak 5. It is also demonstrated that possible changes in the trapping cross section of the LC and the competitive centres due to increasing sample/glow peak temperature do not significantly influence these observations/conclusions.

A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations

NASA Technical Reports Server (NTRS)

Parrott, M. H.; Hinze, W. J.; Braile, L. W.; Vonfrese, R. R. B.

1985-01-01

Flat-Earth modeling is a desirable alternative to the complex spherical-Earth modeling process. These methods were compared using 2 1/2 dimensional flat-earth and spherical modeling to compute gravity and scalar magnetic anomalies along profiles perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Comparison was achieved with percent error computations (spherical-flat/spherical) at critical anomaly points. At the peak gravity anomaly value, errors are less than + or - 5% for all prisms. At 1/2 and 1/10 of the peak, errors are generally less than 10% and 40% respectively, increasing to these values with longer and wider prisms at higher altitudes. For magnetics, the errors at critical anomaly points are less than -10% for all prisms, attaining these magnitudes with longer and wider prisms at higher altitudes. In general, in both gravity and magnetic modeling, errors increase greatly for prisms wider than 500 km, although gravity modeling is more sensitive than magnetic modeling to spherical-Earth effects. Preliminary modeling of both satellite gravity and magnetic anomalies using flat-Earth assumptions is justified considering the errors caused by uncertainties in isolating anomalies.

Speciation studies of nickel and chromium in wastewater from an electroplating plant.

PubMed

Kiptoo, Jackson K; Ngila, J Catherine; Sawula, Gerald M

2004-09-08

A speciation scheme involving the use of flame atomic absorption spectrometry (FAAS) and differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) techniques was applied to studies of nickel and chromium in wastewater from a nickel-chrome electroplating plant. Dimethylglyoxime (DMG) and diethylenetriaminepentaacetic acid (DTPA) were employed as complexing agents for adsorptive voltammetric determination of Ni and Cr, respectively. Cr(III) and Cr(VI) were determined by exploiting differences in their reactivity towards DTPA at HMDE. Total dissolved metal content was in the range 2906-3141 and 30.7-31.2mgl(-1) for Ni and Cr, respectively. A higher percentage of the metal was present as labile species (mean value of 67.9% for Ni and 79.8% for Cr) suggesting that strongly binding ligands are not ubiquitous in the sample. About 77.8% of Cr was found to exist in the higher oxidization state, Cr(IV). Results on effect of dilution on lability of the metal forms in the sample using DPAdCSV showed slight peak shifts to a more negative (cathodic) value by -0.036V for Ni and -0.180V for Cr with a dilution factor of 100, while peak intensity (cathodic current) remained fairly constant.

Diurnal glycemic profile in obese and normal weight nondiabetic pregnant women.

PubMed

Yogev, Yariv; Ben-Haroush, Avi; Chen, Rony; Rosenn, Barak; Hod, Moshe; Langer, Oded

2004-09-01

A paucity of data exists concerning the normal glycemic profile in nondiabetic pregnancies. Using a novel approach that provides continuous measurement of blood glucose, we sought to evaluate the ambulatory daily glycemic profile in the second half of pregnancy in nondiabetic women. Fifty-seven obese and normal weight nondiabetic subjects were evaluated for 72 consecutive hours with continuous glucose monitoring by measurement interstitial glucose levels in subcutaneous tissue every 5 minutes. Subjects were instructed not to modify their lifestyle or to follow any dietary restriction. For each woman, mean and fasting blood glucose values were determined; for each meal during the study period, the first 180 minutes were analyzed. For the study group, the fasting blood glucose level was 75 +/- 12 mg/dL; the mean blood glucose level was 83.7 +/- 18 mg/dL; the postprandial peak glucose value level was 110 +/- 16 mg/dL, and the time interval that was needed to reach peak postprandial glucose level was 70 +/- 13 minutes. A similar postprandial glycemic profile was obtained for breakfast, lunch, and dinner. Obese women were characterized by a significantly higher postprandial glucose peak value, increased 1- and 2-hour postprandial glucose levels, increased time interval for glucose peak, and significantly lower mean blood glucose during the night. No difference was found in fasting and mean blood glucose between obese and nonobese subjects. Glycemic profile characterization in both obese and normal weight nondiabetic subjects provide a measure for the desired level of glycemic control in pregnancy that is complicated with diabetes mellitus.

Chronodisruption in lung cancer and possible therapeutic approaches.

PubMed

Mazzoccoli, Gianluigi; Tarquini, Roberto; Durfort, Tiphanie; Francois, Jean-Christophe

2011-10-01

A customary temporal organization of physiological functions and biological processes is necessary to maintain body homeostasis and an altered body time structure may favour carcinogenesis. There is growing evidence that GH stimulates cancer growth, IGF1 may have a role in carcinogenesis and cancer promotion, GH-IGF1 axis, TRH, TSH, thyroxine, melatonin and cortisol modulate immune cell function and the immune system is often dysfunctional in patients with malignancies. The aim of our study was to evaluate GH-IGF1 axis, hypothalamus-pituitary-thyroid axis, melatonin, cortisol, lymphocyte subsets and IL2 in lung cancer patients. Peripheral blood samples were collected at 4-hour intervals in a 24-hour period from eleven healthy male subjects (age range 35-53 years) and nine male patients suffering from non-small cell lung cancer (age range 43-63 years). In each blood sample, lymphocyte subpopulations (CD3+, CD4+, CD8+, CD16+, CD20+, CD25+, HLA-DR+, γδTcR bearing cells) were analyzed and GH, IGF1, TRH, TSH, FT4, melatonin, cortisol and IL2 were measured. Circadian rhythmicity was evaluated and MESOR, amplitude and acrophase values were compared. In healthy subjects a significant circadian rhythm could be demonstrated with midday peaks for CD8+, CD16+, γδTCR expressing cells and cortisol, and peaks during the night for CD3+, CD4+, GH, TSH and melatonin. A borderline significant rhythm was also observed for CD20+, with a peak late in the evening. IGF1, TRH, FT4 and IL2 values did not show rhythmic variation. In cancer patients a significant circadian rhythm could be demonstrated with diurnal peak for CD16+ and peaks during the night for CD4+ and melatonin. GH, IGF1, TRH, TSH, FT4, cortisol and IL2 values did not show rhythmic variation. MESOR of CD8+ (P<0.0001), CD20+ (P=0.05), γδTCR expressing cells (P=0.01), IGF1 (P<0.001) and TSH (P=0.032) was higher in healthy subjects, whereas MESOR of CD16+ (P<0.0001), CD25+ (P=0.001), GH (P<0.001), TRH (P=0.002), FT4 (P=0.030), cortisol (P=0.01) and IL2 (P=0.02) was higher in cancer patients. Amplitude of circadian variation of γδTCR expressing cells (P=0.01), TSH (P<0.001) and cortisol (P=0.01) was higher in healthy subjects, whereas amplitude of circadian variation of CD4+ was higher in cancer patients (P=0.02). In conclusion, non-small cell lung cancer patients show severe alterations of periodic and quantitative characteristics of neuroendocrine and immune parameters with loss of circadian rhythmicity and internal desynchronization, leading to chronodisruption. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Tunability of temperature-dependent absorption in a graphene-based hybrid nanostructure cavity

NASA Astrophysics Data System (ADS)

Rashidi, Arezou; Namdar, Abdolrahman

2018-04-01

Enhanced absorption is obtained in a hybrid nanostructure composed of graphene and one-dimensional photonic crystal as a cavity in the visible wavelength range thanks to the localized electric field around the defect layers. The temperature-induced wavelength shift is revealed in the absorption spectra in which the peak wavelength is red-shifted by increasing the temperature. This temperature dependence comes from the thermal expansion and thermo-optical effects in the constituent layers of the structure. Moreover, the absorption peaks can be adjusted by varying the incident angle. The results show that absorption is sensitive to TE/TM polarization and its peak values for the TE mode are higher than the TM case. Also, the peak wavelength is blue-shifted by increasing the incident angle for both polarizations. Finally, the possibility of tuning the absorption using the electro-optical response of graphene sheets is discussed in detail. We believe our study may be beneficial for designing tunable graphene-based temperature-sensitive absorbers.

Comparison of autochthonous and imported cases of hepatitis A or hepatitis E.

PubMed

Hartl, J; Kreuels, B; Polywka, S; Addo, M; Luethgehetmann, M; Dandri, M; Dammermann, W; Sterneck, M; Lohse, A W; Pischke, S

2015-07-01

Hepatitis A and hepatitis E are not limited to tropical countries but are also present in industrialized countries. Both infections share similar clinical features. There is no comparative study evaluating the clinical parameters of autochthonous and imported hepatitis A virus and hepatitis E virus infections. The aim of this study was to determine differences between autochthonous and imported hepatitis A virus (HAV) and hepatitis E virus (HEV) infections. Medical charts of all patients at our center with acute HAV and HEV infections were analyzed retrospectively (n = 50, study period 01/2009 - 08/2013). Peak bilirubin (median 8.6 vs. 4.4 mg/dL, p = 0.008) and ALT levels (median 2998 vs. 1666 IU/mL, p = 0.04) were higher in patients with hepatitis A compared to hepatitis E. In comparison to autochthones hepatitis E cases, patients with imported infections had significantly higher peak values for AST, ALT, bilirubin and INR (p = 0.009, p = 0.002, p = 0.04 and p = 0.049, respectively). In HAV infection, AST levels tended to be higher in imported infections (p = 0.08). (i) It is not possible to differentiate certainly between acute HAV and HEV infections by clinical or biochemical parameters, however, HAV infections might be associated with more cholestasis and higher ALT values. (ii) Imported HEV infections are associated with higher transaminases, INR and bilirubin levels compared to autochthonous cases and (iii) imported HAV infections tend to be associated with higher transaminases in comparison to autochthonous cases. © Georg Thieme Verlag KG Stuttgart · New York.

Peak oxygen uptake in Paralympic sitting sports: A systematic literature review, meta- and pooled-data analysis.

PubMed

Baumgart, Julia Kathrin; Brurok, Berit; Sandbakk, Øyvind

2018-01-01

Peak oxygen uptake (VO2peak) in Paralympic sitting sports athletes represents their maximal ability to deliver energy aerobically in an upper-body mode, with values being influenced by sex, disability-related physiological limitations, sport-specific demands, training status and how they are tested. To identify VO2peak values in Paralympic sitting sports, examine between-sports differences and within-sports variations in VO2peak and determine the influence of sex, age, body-mass, disability and test-mode on VO2peak. Systematic literature review and meta-analysis. PubMed, CINAHL, SPORTDiscusTM and EMBASE were systematically searched in October 2016 using relevant medical subject headings, keywords and a Boolean. Studies that assessed VO2peak values in sitting sports athletes with a disability in a laboratory setting were included. Data was extracted and pooled in the different sports disciplines, weighted by the Dersimonian and Laird random effects approach. Quality of the included studies was assessed with a modified version of the Downs and Black checklist by two independent reviewers. Meta-regression and pooled-data multiple regression analyses were performed to assess the influence of sex, age, body-mass, disability, test mode and study quality on VO2peak. Of 6542 retrieved articles, 57 studies reporting VO2peak values in 14 different sitting sports were included in this review. VO2peak values from 771 athletes were used in the data analysis, of which 30% participated in wheelchair basketball, 27% in wheelchair racing, 15% in wheelchair rugby and the remaining 28% in the 11 other disciplines. Fifty-six percent of the athletes had a spinal cord injury and 87% were men. Sports-discipline-averaged VO2peak values ranged from 2.9 L∙min-1 and 45.6 mL∙kg-1∙min-1 in Nordic sit skiing to 1.4 L∙min-1 and 17.3 mL∙kg-1∙min-1 in shooting and 1.3 L∙min-1 and 18.9 mL∙kg-1∙min-1 in wheelchair rugby. Large within-sports variation was found in sports with few included studies and corresponding low sample sizes. The meta-regression and pooled-data multiple regression analyses showed that being a man, having an amputation, not being tetraplegic, testing in a wheelchair ergometer and treadmill mode, were found to be favorable for high absolute and body-mass normalized VO2peak values. Furthermore, high body mass was favourable for high absolute VO2peak values and low body mass for high body-mass normalized VO2peak values. The highest VO2peak values were found in Nordic sit skiing, an endurance sport with continuously high physical efforts, and the lowest values in shooting, a sport with low levels of displacement, and in wheelchair rugby where mainly athletes with tetraplegia compete. However, VO2peak values need to be interpreted carefully in sports-disciplines with few included studies and large within-sports variation. Future studies should include detailed information on training status, sex, age, test mode, as well as the type and extent of disability in order to more precisely evaluate the effect of these factors on VO2peak.

Peak oxygen uptake in Paralympic sitting sports: A systematic literature review, meta- and pooled-data analysis

PubMed Central

Brurok, Berit; Sandbakk, Øyvind

2018-01-01

Background Peak oxygen uptake (VO2peak) in Paralympic sitting sports athletes represents their maximal ability to deliver energy aerobically in an upper-body mode, with values being influenced by sex, disability-related physiological limitations, sport-specific demands, training status and how they are tested. Objectives To identify VO2peak values in Paralympic sitting sports, examine between-sports differences and within-sports variations in VO2peak and determine the influence of sex, age, body-mass, disability and test-mode on VO2peak. Design Systematic literature review and meta-analysis. Data sources PubMed, CINAHL, SPORTDiscusTM and EMBASE were systematically searched in October 2016 using relevant medical subject headings, keywords and a Boolean. Eligibility criteria Studies that assessed VO2peak values in sitting sports athletes with a disability in a laboratory setting were included. Data synthesis Data was extracted and pooled in the different sports disciplines, weighted by the Dersimonian and Laird random effects approach. Quality of the included studies was assessed with a modified version of the Downs and Black checklist by two independent reviewers. Meta-regression and pooled-data multiple regression analyses were performed to assess the influence of sex, age, body-mass, disability, test mode and study quality on VO2peak. Results Of 6542 retrieved articles, 57 studies reporting VO2peak values in 14 different sitting sports were included in this review. VO2peak values from 771 athletes were used in the data analysis, of which 30% participated in wheelchair basketball, 27% in wheelchair racing, 15% in wheelchair rugby and the remaining 28% in the 11 other disciplines. Fifty-six percent of the athletes had a spinal cord injury and 87% were men. Sports-discipline-averaged VO2peak values ranged from 2.9 L∙min-1 and 45.6 mL∙kg-1∙min-1 in Nordic sit skiing to 1.4 L∙min-1 and 17.3 mL∙kg-1∙min-1 in shooting and 1.3 L∙min-1 and 18.9 mL∙kg-1∙min-1 in wheelchair rugby. Large within-sports variation was found in sports with few included studies and corresponding low sample sizes. The meta-regression and pooled-data multiple regression analyses showed that being a man, having an amputation, not being tetraplegic, testing in a wheelchair ergometer and treadmill mode, were found to be favorable for high absolute and body-mass normalized VO2peak values. Furthermore, high body mass was favourable for high absolute VO2peak values and low body mass for high body-mass normalized VO2peak values. Conclusion The highest VO2peak values were found in Nordic sit skiing, an endurance sport with continuously high physical efforts, and the lowest values in shooting, a sport with low levels of displacement, and in wheelchair rugby where mainly athletes with tetraplegia compete. However, VO2peak values need to be interpreted carefully in sports-disciplines with few included studies and large within-sports variation. Future studies should include detailed information on training status, sex, age, test mode, as well as the type and extent of disability in order to more precisely evaluate the effect of these factors on VO2peak. PMID:29474386

Simultaneous Planck , Swift , and Fermi observations of X-ray and γ -ray selected blazars

DOE PAGES

Giommi, P.; Polenta, G.; Lähteenmäki, A.; ...

2012-05-22

We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and γ-ray bands, with additional 5GHz flux-density limits to ensure a good probability of a Planck detection. We compare our results to those of a companion paper presenting simultaneous Planck and multi-frequency observations of 104 radio-loud northern active galactic nuclei selected at radio frequencies. While we confirm several previous results, our unique data set allows us to demonstrate that the selection method strongly influences the results, producing biases that cannot be ignored. Almost all themore » BL Lac objects have been detected by the Fermi Large AreaTelescope (LAT), whereas 30% to 40% of the flat-spectrum radio quasars (FSRQs) in the radio, soft X-ray, and hard X-ray selected samples are still below the γ-ray detection limit even after integrating 27 months of Fermi-LAT data. The radio to sub-millimetre spectral slope of blazars is quite flat, with >α> ~ 0 up to about 70GHz, above which it steepens to ~ -0.65. The BL Lacs have significantly flatter spectra than FSRQs at higher frequencies. The distribution of the rest-frame synchrotron peak frequency (ν peak S) in the spectral energy distribution (SED) of FSRQs is the same in all the blazar samples with peak S> = 10 13.1 ± 0.1 Hz, while the mean inverse Compton peak frequency, >ν peak IC>, ranges from 1021 to 1022 Hz. The distributions of ν peak S and ν peak IC of BL Lacs are much broader and are shifted to higher energies than those of FSRQs; their shapes strongly depend on the selection method. The Compton dominance of blazars, defined as the ratio of the inverse Compton to synchrotron peak luminosities, ranges from less than 0.2 to nearly 100, with only FSRQs reaching values larger than about 3. Its distribution is broad and depends strongly on the selection method, with γ-ray selected blazars peaking at ~7 or more, and radio-selected blazars at values close to 1, thus implying that the common assumption that the blazar power budget is largely dominated by high-energy emission is a selection effect. A comparison of our multi-frequency data with theoretical predictions shows that simple homogeneous SSC models cannot explain the simultaneous SEDs of most of the γ-ray detected blazars in all samples. The SED of the blazars that were not detected by Fermi-LAT may instead be consistent with SSC emission. Our data challenge the correlation between bolometric luminosity and ν peak S predicted by the blazar sequence.« less

Investigations on optical properties of Eu3+ ion doped magnesium telluroborate glasses for red laser applications

NASA Astrophysics Data System (ADS)

Arunkumar, S.; Annapoorani, K.; Marimuthu, K.

2018-04-01

Eu3+ doped Magnesium telluroborate glasses were prepared with the chemical composition (40-x)H3BO3+35 TeO2+15MgCO3+10MgF2+xEu2O3 (where x = 0.1, 0.5, 1.0 and 2.0 in wt%) following the melt quenching technique and labeled as MTB0.1Eu, MTB0.5Eu, MTB1.0Eu and MTB2.0Eu respectively. The absorption spectra exhibit seven peaks in the visible and NIR region. Five emission peaks corresponding to the 5D0→7FJ (J=0, 1, 2, 3, 4) transitions were observed while exciting at 465 nm. The luminescence intensity ratio (R) and Ω2 parameter values were found to be higher for the MTB0.5Eu glass thus indicates the higher asymmetry around the Eu3+ ions site compared to other prepared glasses. The CIE color chromaticity coordinates of the present glasses are found to lie in the prominent red region in the chromaticity diagram. The stimulated emission cross-section value of the MTB0.5Eu glass was found to be higher pertaining to the 5D0 → 7F2 transition compared to the other prepared glasses and reported literature thus suggests its suitability for red laser applications.

Determination of the measurement threshold in gamma-ray spectrometry.

PubMed

Korun, M; Vodenik, B; Zorko, B

2017-03-01

In gamma-ray spectrometry the measurement threshold describes the lover boundary of the interval of peak areas originating in the response of the spectrometer to gamma-rays from the sample measured. In this sense it presents a generalization of the net indication corresponding to the decision threshold, which is the measurement threshold at the quantity value zero for a predetermined probability for making errors of the first kind. Measurement thresholds were determined for peaks appearing in the spectra of radon daughters 214 Pb and 214 Bi by measuring the spectrum 35 times under repeatable conditions. For the calculation of the measurement threshold the probability for detection of the peaks and the mean relative uncertainty of the peak area were used. The relative measurement thresholds, the ratios between the measurement threshold and the mean peak area uncertainty, were determined for 54 peaks where the probability for detection varied between some percent and about 95% and the relative peak area uncertainty between 30% and 80%. The relative measurement thresholds vary considerably from peak to peak, although the nominal value of the sensitivity parameter defining the sensitivity for locating peaks was equal for all peaks. At the value of the sensitivity parameter used, the peak analysis does not locate peaks corresponding to the decision threshold with the probability in excess of 50%. This implies that peaks in the spectrum may not be located, although the true value of the measurand exceeds the decision threshold. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative analyses of bicyclists and motorcyclists in vehicle collisions focusing on head impact responses.

PubMed

Wang, Xinghua; Peng, Yong; Yi, Shengen

2017-11-01

To investigate the differences of the head impact responses between bicyclists and motorcyclists in vehicle collisions. A series of vehicle-bicycle and vehicle-motorcycle lateral impact simulations on four vehicle types at seven vehicle speeds (30, 35, 40, 45, 50, 55 and 60 km/h) and three two-wheeler moving speeds (5, 7.5 and 10 km/h for bicycle, 10, 12.5 and 15 km/h for motorcycle) were established based on PC-Crash software. To further comprehensively explore the differences, additional impact scenes with other initial conditions, such as impact angle (0, π/3, 2π/3 and π) and impact position (left, middle and right part of vehicle front-end), also were supplemented. And then, extensive comparisons were accomplished with regard to average head peak linear acceleration, average head impact speed, average head peak angular acceleration, average head peak angular speed and head injury severity. The results showed there were prominent differences of kinematics and body postures for bicyclists and motorcyclists even under same impact conditions. The variations of bicyclist head impact responses with the changing of impact conditions were a far cry from that of motorcyclists. The average head peak linear acceleration, average head impact speed and average head peak angular acceleration values were higher for motorcyclists than for bicyclists in most cases, while the bicyclists received greater average head peak angular speed values. And the head injuries of motorcyclists worsened faster with increased vehicle speed. The results may provide even deeper understanding of two-wheeler safety and contribute to improve the public health affected by road traffic accidents.

Contrast-enhanced transrectal ultrasound for prediction of prostate cancer aggressiveness: The role of normal peripheral zone time-intensity curves.

PubMed

Huang, Hui; Zhu, Zheng-Qiu; Zhou, Zheng-Guo; Chen, Ling-Shan; Zhao, Ming; Zhang, Yang; Li, Hong-Bo; Yin, Li-Ping

2016-12-08

To assess the role of time-intensity curves (TICs) of the normal peripheral zone (PZ) in the identification of biopsy-proven prostate nodules using contrast-enhanced transrectal ultrasound (CETRUS). This study included 132 patients with 134 prostate PZ nodules. Arrival time (AT), peak intensity (PI), mean transit time (MTT), area under the curve (AUC), time from peak to one half (TPH), wash in slope (WIS) and time to peak (TTP) were analyzed using multivariate linear logistic regression and receiver operating characteristic (ROC) curves to assess whether combining nodule TICs with normal PZ TICs improved the prediction of prostate cancer (PCa) aggressiveness. The PI, AUC (p < 0.001 for both), MTT and TPH (p = 0.011 and 0.040 respectively) values of the malignant nodules were significantly higher than those of the benign nodules. Incorporating the PI and AUC values (both, p < 0.001) of the normal PZ TIC, but not the MTT and TPH values (p = 0.076 and 0.159 respectively), significantly improved the AUC for prediction of malignancy (PI: 0.784-0.923; AUC: 0.758-0.891) and assessment of cancer aggressiveness (p < 0.001). Thus, all these findings indicate that incorporating normal PZ TICs with nodule TICs in CETRUS readings can improve the diagnostic accuracy for PCa and cancer aggressiveness assessment.

Self-preservation and structural transition of gas hydrates during dissociation below the ice point: an in situ study using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Zhong, Jin-Rong; Zeng, Xin-Yang; Zhou, Feng-He; Ran, Qi-Dong; Sun, Chang-Yu; Zhong, Rui-Qin; Yang, Lan-Ying; Chen, Guang-Jin; Koh, Carolyn A.

2016-12-01

The hydrate structure type and dissociation behavior for pure methane and methane-ethane hydrates at temperatures below the ice point and atmospheric pressure were investigated using in situ Raman spectroscopic analysis. The self-preservation effect of sI methane hydrate is significant at lower temperatures (268.15 to 270.15 K), as determined by the stable C-H region Raman peaks and AL/AS value (Ratio of total peak area corresponding to occupancies of guest molecules in large cavities to small cavities) being around 3.0. However, it was reduced at higher temperatures (271.15 K and 272.15 K), as shown from the dramatic change in Raman spectra and fluctuations in AL/AS values. The self-preservation effect for methane-ethane double hydrate is observed at temperatures lower than 271.15 K. The structure transition from sI to sII occurred during the methane-ethane hydrate decomposition process, which was clearly identified by the shift in peak positions and the change in relative peak intensities at temperatures from 269.15 K to 271.15 K. Further investigation shows that the selectivity for self-preservation of methane over ethane leads to the structure transition; this kind of selectivity increases with decreasing temperature. This work provides new insight into the kinetic behavior of hydrate dissociation below the ice point.

Transmission, reflection and thermoluminescence studies on GaS{sub 0.75}Se{sub 0.25} layered single crystals

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

Delice, S., E-mail: sdelice@metu.edu.tr; Isik, M.; Gasanly, N.M.

2015-10-15

Highlights: • Optical and thermoluminescence properties of Ga{sub 4}S{sub 3}Se crystals were investigated. • Indirect and direct band gap energies were found as 2.39 and 2.53 eV, respectively. • The activation energy of the trap center was determined as 495 meV. - Abstract: Optical and thermoluminescence properties on GaS{sub 0.75}Se{sub 0.25} crystals were investigated in the present work. Transmission and reflection measurements were performed at room temperature in the wavelength range of 400–1000 nm. Analysis revealed the presence of indirect and direct transitions with band gap energies of 2.39 and 2.53 eV, respectively. TL spectra obtained at low temperatures (10–300more » K) exhibited one peak having maximum temperature of 168 K. Observed peak was analyzed using curve fitting, initial rise and peak shape methods to calculate the activation energy of the associated trap center. All applied methods were consistent with the value of 495 meV. Attempt-to-escape-frequency and capture cross section of the trap center were determined using the results of curve fitting. Heating rate dependence studies of the glow curve in the range of 0.4–0.8 K/s resulted with decrease of TL intensity and shift of the peak maximum temperature to higher values.« less

[Kriging analysis of vegetation index depression in peak cluster karst area].

PubMed

Yang, Qi-Yong; Jiang, Zhong-Cheng; Ma, Zu-Lu; Cao, Jian-Hua; Luo, Wei-Qun; Li, Wen-Jun; Duan, Xiao-Fang

2012-04-01

In order to master the spatial variability of the normal different vegetation index (NDVI) of the peak cluster karst area, taking into account the problem of the mountain shadow "missing" information of remote sensing images existing in the karst area, NDVI of the non-shaded area were extracted in Guohua Ecological Experimental Area, in Pingguo County, Guangxi applying image processing software, ENVI. The spatial variability of NDVI was analyzed applying geostatistical method, and the NDVI of the mountain shadow areas was predicted and validated. The results indicated that the NDVI of the study area showed strong spatial variability and spatial autocorrelation resulting from the impact of intrinsic factors, and the range was 300 m. The spatial distribution maps of the NDVI interpolated by Kriging interpolation method showed that the mean of NDVI was 0.196, apparently strip and block. The higher NDVI values distributed in the area where the slope was greater than 25 degrees of the peak cluster area, while the lower values distributed in the area such as foot of the peak cluster and depression, where slope was less than 25 degrees. Kriging method validation results show that interpolation has a very high prediction accuracy and could predict the NDVI of the shadow area, which provides a new idea and method for monitoring and evaluation of the karst rocky desertification.

Influence of 10 % Cold Rolling Reduction on Ageing Behaviour of Hot Rolled Al-Cu-Si-Mn-Mg Alloy

NASA Astrophysics Data System (ADS)

Ghosh, S. K.

2014-10-01

In the current study, the effect of 10 % cold rolling on the different ageing phenomena of Al-Cu-Si-Mn-Mg alloy was investigated. Both hot rolled and cold rolled alloys were subjected to both natural and artificial ageing processes. Hardness was measured to understand the change in the mechanical property of the alloy before and after rolling and also during ageing processes. From microscopy, it was evident that the cold rolling and subsequent ageing provided the alloy with a structure in which CuAl2 precipitates were uniformly distributed. The alloy exhibited the peak hardness value of 92 VHN after 2 days of natural ageing, whereas the cold deformed (10 %) alloy exhibited the higher peak hardness value of 139 VHN after 3 days of natural ageing. Peak hardness of the alloy reached 94 VHN, when hot rolled alloy was subjected to ageing at 250 °C for 1 h, whereas 10 % cold rolling followed by ageing (100 °C, 15 min) demonstrated accelerated and elevated hardening. The ageing behaviours thus obtained permit the alloy to provide a range of desirable combinations of strength and ductility for high strength weight saving applications.

Photoelectron and computational studies of the copper-nucleoside anionic complexes, Cu{sup -}(cytidine) and Cu{sup -}(uridine)

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

Li Xiang; Ko, Yeon-Jae; Wang Haopeng

2011-02-07

The copper-nucleoside anions, Cu{sup -}(cytidine) and Cu{sup -}(uridine), have been generated in the gas phase and studied by both experimental (anion photoelectron spectroscopy) and theoretical (density functional calculations) methods. The photoelectron spectra of both systems are dominated by single, intense, and relatively narrow peaks. These peaks are centered at 2.63 and 2.71 eV for Cu{sup -}(cytidine) and Cu{sup -}(uridine), respectively. According to our calculations, Cu{sup -}(cytidine) and Cu{sup -}(uridine) species with these peak center [vertical detachment energy (VDE)] values correspond to structures in which copper atomic anions are bound to the sugar portions of their corresponding nucleosides largely through electrostaticmore » interactions; the observed species are anion-molecule complexes. The combination of experiment and theory also reveal the presence of a slightly higher energy, anion-molecule complex isomer in the case of the Cu{sup -}(cytidine). Furthermore, our calculations found that chemically bond isomers of these species are much more stable than their anion-molecule complex counterparts, but since their calculated VDE values are larger than the photon energy used in these experiments, they were not observed.« less

Tuning the Fano factor of graphene via Fermi velocity modulation

NASA Astrophysics Data System (ADS)

Lima, Jonas R. F.; Barbosa, Anderson L. R.; Bezerra, C. G.; Pereira, Luiz Felipe C.

2018-03-01

In this work we investigate the influence of a Fermi velocity modulation on the Fano factor of periodic and quasi-periodic graphene superlattices. We consider the continuum model and use the transfer matrix method to solve the Dirac-like equation for graphene where the electrostatic potential, energy gap and Fermi velocity are piecewise constant functions of the position x. We found that in the presence of an energy gap, it is possible to tune the energy of the Fano factor peak and consequently the location of the Dirac point, by a modulation in the Fermi velocity. Hence, the peak of the Fano factor can be used experimentally to identify the Dirac point. We show that for higher values of the Fermi velocity the Fano factor goes below 1/3 at the Dirac point. Furthermore, we show that in periodic superlattices the location of Fano factor peaks is symmetric when the Fermi velocity vA and vB is exchanged, however by introducing quasi-periodicity the symmetry is lost. The Fano factor usually holds a universal value for a specific transport regime, which reveals that the possibility of controlling it in graphene is a notable result.

Does power indicate capacity? 30-s Wingate anaerobic test vs. maximal accumulated O2 deficit.

PubMed

Minahan, C; Chia, M; Inbar, O

2007-10-01

The purpose of this study was to evaluate the relationship between anaerobic power and capacity. Seven men and seven women performed a 30-s Wingate Anaerobic Test on a cycle ergometer to determine peak power, mean power, and the fatigue index. Subjects also cycled at a work rate predicted to elicit 120 % of peak oxygen uptake to exhaustion to determine the maximal accumulated O (2) deficit. Peak power and the maximal accumulated O (2) deficit were significantly correlated (r = 0.782, p = 0.001). However, when the absolute difference in exercise values between groups (men and women) was held constant using a partial correlation, the relationship diminished (r = 0.531, p = 0.062). In contrast, we observed a significant correlation between fatigue index and the maximal accumulated O (2) deficit when controlling for gender (r = - 0.597, p = 0.024) and the relationship remained significant when values were expressed relative to active muscle mass. A higher anaerobic power does not indicate a greater anaerobic capacity. Furthermore, we suggest that the ability to maintain power output during a 30-s cycle sprint is related to anaerobic capacity.

Clinical implications in laboratory parameter values in acute Kawasaki disease for early diagnosis and proper treatment.

PubMed

Seo, Yu-Mi; Kang, Hyun-Mi; Lee, Sung-Churl; Yu, Jae-Won; Kil, Hong-Ryang; Rhim, Jung-Woo; Han, Ji-Whan; Lee, Kyung-Yil

2018-05-01

This study aimed to analyse laboratory values according to fever duration, and evaluate the relationship across these values during the acute phase of Kawasaki disease (KD) to aid in the early diagnosis for early-presenting KD and incomplete KD patients. Clinical and laboratory data of patients with KD (n=615) were evaluated according to duration of fever at presentation, and were compared between patients with and without coronary artery lesions (CALs). For evaluation of the relationships across laboratory indices, patients with a fever duration of 5 days or 6 days were used (n=204). The mean fever duration was 6.6±2.3 days, and the proportions of patients with CALs was 19.3% (n=114). C-reactive proteins (CRPs) and neutrophil differential values were highest and hemoglobin, albumin, and lymphocyte differential values were lowest in the 6-day group. Patients with CALs had longer total fever duration, higher CRP and neutrophil differential values and lower hemoglobin and albumin values compared to patients without CALs. CRP, albumin, neutrophil differential, and hemoglobin values at the peak inflammation stage of KD showed positive or negative correlations each other. The severity of systemic inflammation in KD was reflected in the laboratory values including CRP, neutrophil differential, albumin, and hemoglobin. Observing changes in these laboratory parameters by repeated examinations prior to the peak of inflammation in acute KD may aid in diagnosis of early-presenting KD patients.

The GALAH Survey: Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere and metallicity

NASA Astrophysics Data System (ADS)

Quillen, Alice C.; De Silva, Gayandhi; Sharma, Sanjib; Hayden, Michael; Freeman, Ken; Bland-Hawthorn, Joss; Žerjal, Maruša; Asplund, Martin; Buder, Sven; D'Orazi, Valentina; Duong, Ly; Kos, Janez; Lin, Jane; Lind, Karin; Martell, Sarah; Schlesinger, Katharine; Simpson, Jeffrey D.; Zucker, Daniel B.; Zwitter, Tomaz; Anguiano, Borja; Carollo, Daniela; Casagrande, Luca; Cotar, Klemen; Cottrell, Peter L.; Ireland, Michael; Kafle, Prajwal R.; Horner, Jonathan; Lewis, Geraint F.; Nataf, David M.; Ting, Yuan-Sen; Watson, Fred; Wittenmyer, Rob; Wyse, Rosemary

2018-04-01

Using GALAH survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H]>0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.

How we remember the emotional intensity of past musical experiences

PubMed Central

Schäfer, Thomas; Zimmermann, Doreen; Sedlmeier, Peter

2014-01-01

Listening to music usually elicits emotions that can vary considerably in their intensity over the course of listening. Yet, after listening to a piece of music, people are easily able to evaluate the music's overall emotional intensity. There are two different hypotheses about how affective experiences are temporally processed and integrated: (1) all moments' intensities are integrated, resulting in an averaged value; (2) the overall evaluation is built from specific single moments, such as the moments of highest emotional intensity (peaks), the end, or a combination of these. Here we investigated what listeners do when building an overall evaluation of a musical experience. Participants listened to unknown songs and provided moment-to-moment ratings of experienced intensity of emotions. Subsequently, they evaluated the overall emotional intensity of each song. Results indicate that participants' evaluations were predominantly influenced by their average impression but that, in addition, the peaks and end emotional intensities contributed substantially. These results indicate that both types of processes play a role: All moments are integrated into an averaged value but single moments might be assigned a higher value in the calculation of this average. PMID:25177311

Palmar pressure distribution during push-up exercise.

PubMed

Chuckpaiwong, B; Harnroongroj, T

2009-07-01

Doing repetitive push-ups is among the most common exercise for the upper body and shoulder stabiliser muscle strength training. However, adverse effects such as neck pain, back pain, palmar pain and wrist pain have been reported. To date, to our knowledge, palmar pressure when performing push-ups has not been previously reported. We hypothesised that various hand positions during push-ups may provide different palmar pressures. Bilateral palmar pressures were recorded in ten individual volunteers. All the subjects were set up for doing push-ups in five positions of the hand. Peak palmar pressure was recorded by Emed pressure platform system (Novel GmBH, Munich, Germany). The palm was divided into the following five anatomic regions, viz. thenar, lunate, hypothenar, metacarpals and fingers. Statistical comparison between the five positions of the hand was analysed using the analysis of variance test. A distribution of the mean peak pressure of the lunate and hypothenar areas were relatively higher than the other areas in both standby and full-elbow flexion positions. At the palmar position 30 cm wider than the shoulder width, the palmar pressure revealed significantly higher peak pressure in the lunate area in the standby and fully-flexed elbow positions (p-value is less than 0.05). At the palmar position 10 cm narrower than the shoulder width, palmar pressure showed significantly higher peak pressure in the hypothenar area only in the fully-flexed elbow position. The information regarding palmar pressures while performing push-ups in different hand positions may be used as a guideline for exercise modification, especially in injured athletes.

Characteristics of patients with a relatively greater minimum VE/VCO2 against peak VO2% and impaired exercise tolerance.

PubMed

Nakade, Taisuke; Adachi, Hitoshi; Murata, Makoto; Oshima, Shigeru

2018-05-14

Cardiopulmonary exercise testing (CPX) is used to evaluate functional capacity and assess prognosis in cardiac patients. Ventilatory efficiency (VE/VCO 2 ) reflects ventilation-perfusion mismatch; the minimum VE/VCO 2 value (minVE/VCO 2 ) is representative of pulmonary arterial blood flow in individuals without pulmonary disease. Usually, minVE/VCO 2 has a strong relationship with the peak oxygen uptake (VO 2 ), but dissociation can occur. Therefore, we investigated the relationship between minVE/VCO 2 and predicted peak VO 2 (peak VO 2 %) and evaluated the parameters associated with a discrepancy between these two parameters. A total of 289 Japanese patients underwent CPX using a cycle ergometer with ramp protocols between 2013 and 2014. Among these, 174 patients with a peak VO 2 % lower than 70% were enrolled. Patients were divided into groups based on their minVE/VCO 2 [Low group: minVE/VCO 2  < mean - SD (38.8-5.6); High group: minVE/VCO 2  > mean + SD (38.8 + 5.6)]. The characteristics and cardiac function at rest, evaluated using echocardiography, were compared between groups. The High group had a significantly lower ejection fraction, stroke volume, and cardiac output, and higher brain natriuretic peptide, tricuspid regurgitation pressure gradient, right ventricular systolic pressure, and peak early diastolic LV filling velocity/peak atrial filling velocity ratio compared with the Low group (p's < 0.01). In addition, the Low group had a significantly higher prevalence of pleural effusion than did the High group (26 vs 11%, p < 0.01). Patients with a relatively greater minVE/VCO 2 in comparison with peak VO 2 had impaired cardiac output as well as restricted pulmonary blood flow increase during exercise, partly due to accumulated pleural effusion.

Infant BMI peak as a predictor of overweight and obesity at age 2 years in a Chinese community-based cohort

PubMed Central

Sun, Jie; Nwaru, Bright I; Hua, Jing; Li, Xiaohong; Wu, Zhuochun

2017-01-01

Objectives Infant body mass index (BMI) peak has proven to be a useful indicator for predicting childhood obesity risk in American and European populations. However, it has not been assessed in China. We characterised infant BMI trajectories in a Chinese longitudinal cohort and evaluated whether BMI peak can predict overweight and obesity at age 2 years. Methods Serial measurements (n=6–12) of weight and length were taken from healthy term infants (n=2073) in a birth cohort established in urban Shanghai. Measurements were used to estimate BMI growth curves from birth to 13.5 months using a polynomial regression model. BMI peak characteristics, including age (in months) and magnitude (BMI, in kg/m2) at peak and prepeak velocities (in kg/m2/month), were estimated. The relationship between infant BMI peak and childhood BMI at age 2 years was examined using binary logistic analysis. Results Mean age at peak BMI was 7.61 months, with a magnitude of 18.33 kg/m2. Boys (n=1022) had a higher average peak BMI (18.60 vs 18.07 kg/m2, p<0.001) and earlier average achievement of peak value (7.54 vs 7.67 months, p<0.05) than girls (n=1051). With 1 kg/m2 increase in peak BMI and 1 month increase in peak time, the risk of overweight at age 2 years increased by 2.11 times (OR 3.11; 95% CI 2.64 to 3.66) and 35% (OR 1.35; 95% CI 1.21 to 1.50), respectively. Similarly, higher BMI magnitude (OR 2.69; 95% CI 2.00 to 3.61) and later timing of infant BMI peak (OR 1.35; 95% CI 1.08 to 1.68) were associated with an increased risk of childhood obesity at age 2 years. Conclusions We have shown that infant BMI peak is valuable for predicting early childhood overweight and obesity in urban Shanghai. Because this is the first Chinese community-based cohort study of this nature, future research is required to examine infant populations in other areas of China. PMID:28988164

Visualising neuroinflammation in post-stroke patients: a comparative PET study with the TSPO molecular imaging biomarkers [11C]PK11195 and [11C]vinpocetine.

PubMed

Gulyas, Balazs; Toth, Miklos; Vas, Adam; Shchukin, Evgeni; Kostulas, Konstantinos; Hillert, Jan; Halldin, Christer

2012-01-01

With the main objective of comparing the prospective diagnostic power of two 11C-labelled molecular imaging biomarkers with affinity for TSPO and used for the visualisation of activated microglia after a stroke, we measured with positron emission tomography (PET) in four post-stroke patients the regional brain uptake and binding potential of [11C]vinpocetine and [11C]PK11195. Percentage standard uptake values (%SUV) and binding potential (BPND) were used as outcome measures. The total peak brain uptake value and average global brain uptake value were higher for [11C]vinpocetine than for [11C]PK11195. The regional %SUV values were significantly higher for [11C]vinpocetine than for [11C]PK11195 in the hemispheres as well as in almost all standard brain regions. The %SUV values of [11C]vinpocetine were higher in the peri-infarct zone than in the ischaemic core, however, the difference did not prove to be significant. There was basically no difference in %SUV values between the ischaemic core and the peri-infarct zone for [11C]PK11195. The BPND values for [11C]vinpocetine were higher in all standard regions than those for [11C]PK11195, but the difference was not significant between them. The BPND values of [11C]vinpocetine were higher in the peri-infarct zone than in the ischaemic core, however, the difference did not prove to be significant. A comparative analysis of the two ligands indicates that [11C]vinpocetine shows a number of favourable characteristics over [11C]PK11195, but to demonstrate that it may serve as a prospective molecular imaging biomarker of microglia activation in post-stroke patients, further studies are required.

Extreme changes in the dayside ionosphere during a Carrington-type magnetic storm

NASA Astrophysics Data System (ADS)

Tsurutani, Bruce T.; Verkhoglyadova, Olga P.; Mannucci, Anthony J.; Lakhina, Gurbax S.; Huba, Joseph D.

2012-06-01

It is shown that during the 30 October 2003 superstorm, dayside O+ ions were uplifted to DMSP altitudes (~850 km). Peak densities were ~9 × 105 cm-3 during the magnetic storm main phase (peak Dst = -390 nT). By comparison the 1-2 September 1859 Carrington magnetic storm (peak Dst estimated at -1760 nT) was considerably stronger. We investigate the impact of this storm on the low- to mid-latitude ionosphere using a modified version of the NRL SAMI2 ionospheric code. It is found that the equatorial region (LAT = 0° ± 15°) is swept free of plasma within 15 min (or less) of storm onset. The plasma is swept to higher altitudes and higher latitudes due to E × B convection associated with the prompt penetration electric field. Equatorial Ionization Anomaly (EIA) O+ density enhancements are found to be located within the broad range of latitudes ~ ± (25°-40°) at ~500-900 km altitudes. Densities within these peaks are ~6 × 106 oxygen ions-cm-3 at ~700 km altitude, approximately +600% quiet time values. The oxygen ions at the top portions (850-1000 km) of uplifted EIAs will cause strong low-altitude satellite drag. Calculations are currently being performed on possible uplift of oxygen neutrals by ion-neutral coupling to understand if there might be further significant satellite drag forces present.

Energetics of photosynthetic glow peaks

PubMed Central

DeVault, Don; Govindjee; Arnold, William

1983-01-01

By postulating temperature-dependent equilibria between two or more electron carriers acting as traps for electrons or holes, it is possible to modify the Randall-Wilkins theory of thermoluminescence so as to explain the abnormally large apparent activation energies and apparent frequency factors observed in photosynthetic glow curves when fitted by unmodified Randall-Wilkins theory. The equilibria serve to inhibit the formation of the light-emitting excited state by withholding the needed precursor state. When the inhibition is released at higher temperature by shift of equilibrium with temperature, the rise of the glow peak can be much faster than would result from Arrhenius behavior based on the true activation energy and so appears to correspond to a higher activation energy accompanied by a larger frequency factor. From another viewpoint, the enthalpy changes, ΔH, of the equilibria tend to add to the activation energy. Similarly the entropy changes, ΔS, of the equilibria tend to add to the entropy of activation, giving the large apparent frequency factors. The positive values of ΔS needed would correspond to entropy decreases in the forward early electron transport. A comparison of the glow peaks obtained by different workers is also presented. PMID:16593283

Diversity of band gap and photoluminescence properties of lead halide perovskite: A halogen-dependent spectroscopic study

NASA Astrophysics Data System (ADS)

Yu, Wenlei; Jiang, Yunfeng; Zhu, Xiuwei; Luo, Chunhua; Jiang, Kai; Chen, Liangliang; Zhang, Juan

2018-05-01

The effects of halogen substitution on microstructure, optical absorption, and phonon modes for perovskite CH3NH3PbX3 (MAPbX3, X = I/Br/Cl) films grown on FTO substrates have been investigated. The X-ray diffraction analysis exhibited good crystallization, and the strong diffraction peak assigned to (1 0 0) c for X = Br/Cl shifted toward a higher angle compared to (1 1 0) t of MAPbI3. Band-gap tuning from 1.63 to 2.37 to 3.11 eV in the I-Br-Cl series can be found due to the halogen effects. These energy values closely match the positions of peak determined from photoluminescence experiments. The remarkable absorption dip and emission peak appear for the MAPbBr3, suggesting higher crystallinity under the same preparation conditions. The wavenumbers of main IR-vibrations slightly decrease with ionic radius of the halogen increasing (in the order of Cl-Br-I), which related to the increasing polarizability. These results provide important progress towards the understanding of the halide role in the realization of high performance MAPbX3-based solar cells.

Cardiovascular fitness in obese versus nonobese 8-11-year-old boys and girls.

PubMed

Mastrangelo, M Alysia; Chaloupka, Edward C; Rattigan, Peter

2008-09-01

The purpose of this study was to compare cardiovascular fitness between obese and nonobese children. Based on body mass index, 118 were classified as obese (boys [OB] = 62, girls [OG] = 56), while 421 were nonobese (boys [NOB] = 196, girls [NOG] = 225). Cardiovascular fitness was determined by a 1-mile [1.6 km] run/walk (MRW) and estimated peak oxygen uptake (VO2peak) and analyzed using two-way analyses of variance (Gender x Obese/Nonobese). MRW times were significantly faster (p < .05) for the NOB (10 min 34 s) compared to the OB (13 min 8 s) and the NOG (13 min 15 s.) compared to the OG (14 min 44 s.). Predicted VO2peak values (mL x kg(-1) x min(-1)) were significantly higher (p < .05) for the NOB (48.29) compared to the OB (41.56) and the NOG (45.99) compared to the OG (42.13). MRW was compared between obese and nonobese participants on the President's Challenge (2005), the National Children and Youth Fitness Study, and FITNESSGRAM HFZ standards. The nonobese boys and girls scored higher on all three, exhibiting better cardiovascular fitness as compared to obese counterparts.

Simultaneous Planck, Swift, and Fermi Observations of X-Ray and gamma-Ray Selected Blazars

NASA Technical Reports Server (NTRS)

Giommi, P.; Polenta, G.; Laehteenmaeki, A.; Thompson, D. J.; Capalbi, M.; Cutini, S.; Gasparrini, D.; Gonzalez-Nuevo, J.; Leon-Tavares, J.; Lopez-Caniego, M.;

Observation of a peaking structure in the $$J/\\psi \\phi$$ mass spectrum from $$B^{\\pm} \\to J/\\psi \\phi K^{\\pm}$$ decays

DOE PAGES

Chatrchyan, Serguei

2014-05-22

A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m = 4148.0 +- 2.4 (stat.) +- 6.3more » (syst.) MeV and Gamma = 28 +15 -11 (stat.) +- 19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.« less

Light scattering from normal and cervical cancer cells.

PubMed

Lin, Xiaogang; Wan, Nan; Weng, Lingdong; Zhou, Yong

2017-04-20

The light scattering characteristic plays a very important role in optic imaging and diagnostic applications. For optical detection of the cell, cell scattering characteristics have an extremely vital role. In this paper, we use the finite-difference time-domain (FDTD) algorithm to simulate the propagation and scattering of light in biological cells. The two-dimensional scattering cell models were set up based on the FDTD algorithm. The cell models of normal cells and cancerous cells were established, and the shapes of organelles, such as mitochondria, were elliptical. Based on these models, three aspects of the scattering characteristics were studied. First, the radar cross section (RCS) distribution curves of the corresponding cell models were calculated, then corresponding relationships between the size and the refractive index of the nucleus and light scattering information were analyzed in the three periods of cell canceration. The values of RCS increase positively with the increase of the nucleo-cytoplasmic ratio in the cancerous process when the scattering angle ranges from 0° to 20°. Second, the effect of organelles in the scattering was analyzed. The peak value of the RCS of cells with mitochondria is higher than the cells without mitochondria when the scattering angle ranges from 20° to 180°. Third, we demonstrated that the influence of cell shape is important, and the impact was revealed by the two typical ideal cells: round cells and oval cells. When the scattering angle ranges from 0° to 80°, the peak values and the frequencies of the appearance of the peaks from the two models are roughly similar. It can be concluded that: (1) the size of the nuclei and the change of the refractive index of cells have a certain impact on light scattering information of the whole cell; (2) mitochondria and other small organelles contribute to the cell light scattering characteristics in the larger scattering angle area; and (3) the change of the cell shape significantly influences the value of scattering peak and the deviation of scattering peak position. The results of the numerical simulation will guide subsequent experiments and early diagnosis of cervical cancer.

Tephra compositions from Late Quaternary volcanoes around the Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Kraus, S.

2009-12-01

Crustal extension and rifting processes opened the Bransfield Strait between the South Shetland Islands and the Antarctic Peninsula during the last 4 Ma. Similar processes on the Peninsula's eastern side are responsible for volcanism along Larsen Rift. There are at least 11 volcanic centers with known or suspected Late Pleistocene / Holocene explosive activity (Fig. 1). Fieldwork was carried out on the islands Deception, Penguin, Bridgeman and Paulet, moreover at Melville Peak (King George Is.) and Rezen Peak (Livingston Is.). Of special importance is the second ever reported visit and sampling at Sail Rock, and the work on never before visited outcrops on the northern slopes and at the summit of Cape Purvis volcano (Fig. 1). The new bulk tephra ICP-MS geochemical data provide a reliable framework to distinguish the individual volcanic centers from each other. According to their Mg-number, Melville Peak and Penguin Island represent the most primitive magma source. Nb/Y ratios higher than 0.67 in combination with elevated Th/Yb and Ta/Yb ratios and strongly enriched LREE seem to be diagnostic to distinguish the volcanoes located along the Larsen Rift from those associated with Bransfield Rift. Sr/Y ratios discriminate between the individual Larsen Rift volcanoes, Paulet Island showing considerably higher values than Cape Purvis volcano. Along Bransfield Rift, Bridgeman Island and Melville Peak have notably lower Nb/Y and much higher Th/Nb than Deception Island, Penguin Island and Sail Rock. The latter displays almost double the Th/Yb ratio as compared to Deception Island, and also much higher LREE enrichment but extraordinarily low Ba/Th, discriminating it from Penguin Island. Such extremely low Ba/Th ratios are also typical for Melville Peak, but for none of the other volcanoes. Penguin Island has almost double the Ba/Th and Sr/Y ratios higher than any other investigated volcano. Whereas the volcanoes located in the northern part of Bransfield Strait have Zr/Hf ratios lower than N-MORB, all other volcanoes including the Larsen Rift centers display Zr/Hf higher than N-MORB. It is expected that the correlation of the new data with published data from tephra layers found in ice, lake and marine sediment cores will contribute to a better constrained timing of individual climatic events identified in the northern Antarctic Peninsula area. Late Quaternary volcanoes around the northern Antarctic Peninsula.

Decoupling effect and forecasting of economic growth and energy structure under the peak constraint of carbon emissions in China.

PubMed

Wang, Shijin; Li, Cunfang; Yang, Lizhu

2018-06-26

The decoupling effect between economic growth and energy structure was quantitatively analyzed from 1999 to 2014 across China. The results showed it existed weak decoupling effects in most regions. Based on the analysis of the influence of energy structure on carbon intensity, using scenario simulation methods and Markov chain modeling, the carbon intensity was predicted for China in 2020. The impact of energy structure adjustment on the carbon intensity to meet China's carbon target by 18 possible scenarios are calculated. Furthermore, the peak value of carbon emissions was also calculated in 2030. The results showed that the carbon intensity predicted for China in 2020 can be achieved regardless of whether the energy structure was adjusted or not when energy saving and carbon reduction policies maintained with economic growth at 6-7%. Moreover, given fixed energy structure growth, for each 1% of economic growth, the carbon intensity will decrease by about 3.5%. Given fixed economic growth, the decrease of energy intensity will be greater if the control of energy consumption is stronger. The effect of energy structure adjustment on the decreasing of carbon intensity will be 4% higher under constraints than without constraints. On average, the contribution of energy structure adjustment to achieving the carbon intensity target was calculated as 4% higher than that with constraints. In addition, given relatively fixed economic growth at 6-7%, the peak value of carbon emission in 2030 was calculated as 13.209 billion tons with constraints and 14.38 billion tons without constraints.

A kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces.

PubMed

Koontz, Alicia M; Cooper, Rory A; Boninger, Michael L; Yang, Yusheng; Impink, Bradley G; van der Woude, Lucas H V

2005-01-01

The objective of this study was to conduct a kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces. Eleven manual wheelchairs were fitted with a SMART(Wheel) and their users were asked to push on a course consisting of high- and low-pile carpet, indoor tile, interlocking concrete pavers, smooth level concrete, grass, hardwood flooring, and a sidewalk with a 5-degree grade. Peak resultant force, wheel torque, mechanical effective force, and maximum resultant force rate of rise were analyzed during start-up for each surface and normalized relative to their steady-state values on the smooth level concrete. Additional variables included peak velocity, distance traveled, and number of strokes in the first 5 s of the trial. We compared biomechanical data between surfaces using repeated-measures mixed models and paired comparisons with a Bonferroni adjustment. Applied resultant force (p = 0.0154), wheel torque (p < 0.0001), and mechanical effective force (p = 0.0047) were significantly different between surfaces. The kinetic values for grass, interlocking pavers, and ramp ascent were typically higher compared with tile, wood, smooth level concrete, and high- and low-pile carpet. Users were found to travel shorter distances up the ramp and across grass (p < 0.0025) and had a higher stroke count on the ramp (p = 0.0124). While peak velocity was not statistically different, average velocity was slower for the ramp and grass, which indicates greater wheelchair/user deceleration between strokes. The differences noted between surfaces highlight the importance of evaluating wheelchair propulsion ability over a range of surfaces.

Carbon Isotope Composition as an Indicator of DOC Sources to a Stream During Events in a Temperate Forested Catchment

NASA Astrophysics Data System (ADS)

Doctor, D. H.; Sebestyen, S. D.; Aiken, G. R.; Shanley, J. B.; Kendall, C.; Boyer, E. W.

2006-12-01

Increased DOC flux in streams and rivers is commonly observed during high runoff regimes, however DOC concentrations alone do not provide information about multiple sources or pathways of DOC to streams. In an effort to gain this information, we measured DOC concentrations and stable carbon isotope composition (δ13C-DOC) on samples collected at high-frequency during events at Sleepers River Research Watershed in Vermont, USA. During snowmelt and storm events, peaks in stream DOC concentration (up to 10.5 mg/L) were coincident with peaks in flow. Stream water δ13C-DOC measurements ranged between -23.7‰ and - 28.9‰ and indicated changing sources of DOC during events; the highest δ13C-DOC values occurred consistently at the lowest flows, and the lowest δ13C-DOC values occurred with peaks in discharge. Water samples collected from shallow wells and stacked soil lysimeters showed the highest DOC concentrations in the most shallow (<0.5 m) lysimeter waters, and the lowest concentrations in the deeper (>1.5 m) well waters. Wells and lysimeters exhibited a range of δ13C-DOC values similar to those observed in the stream; however, samples collected from shallow horizons at nested wells and lysimeters consistently showed lower δ13C-DOC values than those from greater depths. Maple leaf litter collected from across the watershed provided an end-member of fresh organic material, with average δ13C composition of -31.3±0.7‰ (n=57), which is lower than the lowest measured DOC values in any of the stream, well, or lysimeter waters. A subset of stream waters were fractionated onto XAD4 and XAD8 resins; the hydrophobic acid fraction (XAD8) had consistently lower δ13C values than the transphilic acid fraction (XAD4), and both of these were lower than those of the bulk DOC. Samples with lower δ13C-DOC values also exhibited higher SUVA-254 values, i.e. greater aromaticity. Thus, lower δ13C-DOC values are interpreted as an indicator of relatively "fresh", more aromatic and more biologically labile material while higher δ13C-DOC values indicate relatively more degraded material. Since lower δ13C-DOC values were observed in the shallowest well and lysimeter waters and in stream water during periods of highest DOC flux, we surmise that fresh DOC is mobilized to the stream along relatively shallow flowpaths during high flows, and that a second source of more degraded DOC supplies background concentrations to the stream at lower flows.

Reconstruction of the Mars Science Laboratory Parachute Performance and Comparison to the Descent Simulation

NASA Technical Reports Server (NTRS)

Cruz, Juan R.; Way, David W.; Shidner, Jeremy D.; Davis, Jody L.; Adams, Douglas S.; Kipp, Devin M.

2013-01-01

The Mars Science Laboratory used a single mortar-deployed disk-gap-band parachute of 21.35 m nominal diameter to assist in the landing of the Curiosity rover on the surface of Mars. The parachute system s performance on Mars has been reconstructed using data from the on-board inertial measurement unit, atmospheric models, and terrestrial measurements of the parachute system. In addition, the parachute performance results were compared against the end-to-end entry, descent, and landing (EDL) simulation created to design, develop, and operate the EDL system. Mortar performance was nominal. The time from mortar fire to suspension lines stretch (deployment) was 1.135 s, and the time from suspension lines stretch to first peak force (inflation) was 0.635 s. These times were slightly shorter than those used in the simulation. The reconstructed aerodynamic portion of the first peak force was 153.8 kN; the median value for this parameter from an 8,000-trial Monte Carlo simulation yielded a value of 175.4 kN - 14% higher than the reconstructed value. Aeroshell dynamics during the parachute phase of EDL were evaluated by examining the aeroshell rotation rate and rotational acceleration. The peak values of these parameters were 69.4 deg/s and 625 deg/sq s, respectively, which were well within the acceptable range. The EDL simulation was successful in predicting the aeroshell dynamics within reasonable bounds. The average total parachute force coefficient for Mach numbers below 0.6 was 0.624, which is close to the pre-flight model nominal drag coefficient of 0.615.

Seasonal variability in somatic and reproductive investment of the bivalve Scrobicularia plana (da Costa, 1778) along a latitudinal gradient

NASA Astrophysics Data System (ADS)

Santos, Sílvia; Cardoso, Joana F. M. F.; Carvalho, Célia; Luttikhuizen, Pieternella C.; van der Veer, Henk W.

2011-03-01

Monthly investment in soma and gonads in the bivalve Scrobicularia plana is described for three populations along its distributional range: Minho estuary, Portugal; Westerschelde estuary, The Netherlands and Buvika estuary, Norway. Seasonal cycles in body mass (BMI), somatic mass (SMI) and gonadal mass (GMI) indices were observed for all populations. In Portugal, BMI and SMI peaked in mid-autumn, while in The Netherlands both indices were at their highest in mid-spring. Norway showed a different pattern with two distinct peaks: one in mid-autumn and a second peak in spring. GMI reached maximum values in July in Portugal and Netherlands and in June in Norway. Overall, mean BMI and SMI were lower in Portugal while mean GMI was lower in Norway. The spawning period lasted the whole summer in Portugal, but was shorter (only two months) in The Netherlands and Norway. The reproductive investment in The Netherlands was significantly higher than in Portugal and Norway, with the lowest values being observed in Norway. Differences in annual cycles between populations were attributed to environmental factors, namely temperature and food availability. Temperature seems important in shaping the reproductive pattern with more northern populations showing shorter reproductive periods starting later in the year, and a lower reproductive output. In addition, winter water temperatures can explain the lower mean body and somatic mass values observed in Portugal. Food availability influenced the physiological performance of the species with peaks in somatic mass coinciding with phytoplankton blooms. This relation between physiological performance and environmental factors influences S. plana distribution, densities and even survival, with natural consequences on its commercial importance.

Explanation of the variance in quality of life and activity capacity of patients with heart failure by laboratory data.

PubMed

Athanasopoulos, Leonidas V; Dritsas, Athanasios; Doll, Helen A; Cokkinos, Dennis V

2010-08-01

This study was conducted to explain the variance in quality of life (QoL) and activity capacity of patients with congestive heart failure from pathophysiological changes as estimated by laboratory data. Peak oxygen consumption (peak VO2) and ventilation (VE)/carbon dioxide output (VCO2) slope derived from cardiopulmonary exercise testing, plasma N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and echocardiographic markers [left atrium (LA), left ventricular ejection fraction (LVEF)] were measured in 62 patients with congestive heart failure, who also completed the Minnesota Living with Heart Failure Questionnaire and the Specific Activity Questionnaire. All regression models were adjusted for age and sex. On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.01, LVEF with P value less than 0.001, LA with P=0.001, and logNT-proBNP with P value less than 0.01 were found to be associated with QoL. On stepwise multiple linear regression, peak VO2 and LVEF continued to be predictive, accounting for 40% of the variability in Minnesota Living with Heart Failure Questionnaire score. On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.001, LVEF with P value less than 0.05, LA with P value less than 0.001, and logNT-proBNP with P value less than 0.001 were found to be associated with activity capacity. On stepwise multiple linear regression, peak VO2 and LA continued to be predictive, accounting for 53% of the variability in Specific Activity Questionnaire score. Peak VO2 is independently associated both with QoL and activity capacity. In addition to peak VO2, LVEF is independently associated with QoL, and LA with activity capacity.

The intramuscular glucagon stimulation test does not provide good discrimination between normal and inadequate ACTH reserve when used in the investigation of short healthy children.

PubMed

Tenenbaum, Ariel; Phillip, Moshe; de Vries, Liat

2014-01-01

Few studies have addressed the role of the glucagon stimulation test (GST) in evaluating the hypothalamic-pituitary-adrenal axis in children. We investigated the diagnostic value of the GST in evaluating the adrenocortical response in short healthy children. The GST was performed in 190 children investigated for short stature. A peak cortisol >500 nmol/l was considered a normal response. In the 45 (23.7%) with subnormal response, a 250-μg ACTH test was done. The rate of subnormal adrenal response to GST was higher among boys (33.9 vs. 8.9%, p < 0.001) and among children ≥6 years than among younger children (32.7 vs. 18.4%, p < 0.02). Both mean basal and peak cortisol levels were higher in girls than in boys: 381 ± 165 vs. 319 ± 151 nmol/l (p = 0.003) and 741 ± 102 vs. 595 ± 208 nmol/l (p < 0.001), respectively. Peak cortisol on GST was associated with basal cortisol (r = 0.45, p < 0.001) but not with glucose nadir (r = -0.31, p = 0.67), peak GH (r = 0.069, p = 0.33) or BMI-SDS (r = -0.08, p = 0.28). Peak cortisol was >500 nmol/l in all the patients undergoing an ACTH stimulation test. Since adrenal response to GST is age- and gender-related and the false-positive rate is high, its routine performance in healthy children warrants reconsideration. © 2014 S. Karger AG, Basel.

Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

DOEpatents

Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

2006-01-03

A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

Effect of enhanced ionizing radiation on the cloud electricity after the Fukushima nuclear accident

NASA Astrophysics Data System (ADS)

Yamauchi, Masatoshi; Takeda, Masahiko; Nagamachi, Shingo

2018-03-01

The vertical downward component of the DC atmospheric electric field, or potential gradient (PG), at Kakioka 150 km southwest of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) was analyzed before and after the FNPP1 accident to examine possible influence of floating radioactive particles on the PG under the highly electrified clouds. Using 1-min PG data from March 13 to April 30 (late April 2011 corresponding to the time when floating radioactive materials decreased significantly) from 2006 to 2015, time profiles to/from the PG peaks (<- 100 or >+ 100 V/m) for 2011 are compared with other years. The PG developed toward and decays from its negative peaks faster in the first 50 days after the FNPP1 accident than for the same period in other years, making the 10-min averaged PG values for the same negative PG peak higher (smaller in terms of absolute value) during the first 50 days after the FNPP1 accident than those in other years in the study period, while the distribution of peak PG values is similar between 2011 and the other years. The observed shortening of the timescale is symmetric between the rise and decay and is the most clear when the negative PG peak is about - 200 to - 400 V/m. For positive peaks, the change of the baseline resulting from the radioactive contamination on the ground in 2011 caused superficial difference on such time profiles. Otherwise, there are no significant difference between 2011 and the other years. Possible explanations based on increased ionizing radiation from floating radioactive particles, which are found to be concentrated at low altitudes (< 500 m according to radiosonde in-situ observations of gamma rays) where negative cloud charges normally exceed positive charges, are discussed. The scenarios discussed include enhanced electrostatic shielding and electric conductivity-led decay rate of cloud charges. The result opens up a new possibility of using PG as an independent monitor of radioactivity at some altitudes in case of nuclear accidents.

Improved measurement of carbonaceous aerosol in Beijing, China: intercomparison of sampling and thermal-optical analysis methods

NASA Astrophysics Data System (ADS)

Cheng, Y.; He, K. B.; Duan, F. K.; Zheng, M.; Ma, Y. L.; Tan, J. H.; Du, Z. Y.

2010-06-01

The sampling artifacts (both positive and negative) and the influence of thermal-optical methods (both charring correction method and the peak inert mode temperature) on the split of organic carbon (OC) and elemental carbon (EC) were evaluated in Beijing. The positive sampling artifact constituted 10% and 23% of OC concentration determined by the bare quartz filter during winter and summer, respectively. For summer samples, the adsorbed gaseous organics were found to continuously evolve off the filter during the whole inert mode when analyzed by the IMPROVE-A temperature protocol. This may be due to the oxidation of the adsorbed organics during sampling (reaction artifact) which would increase their thermal stability. The backup quartz approach was evaluated by a denuder-based method for assessing the positive artifact. The quartz-quartz (QBQ) in series method was demonstrated to be reliable, since all of the OC collected by QBQ was from originally gaseous organics. Negative artifact that could be adsorbed by quartz filter was negligible. When the activated carbon impregnated glass fiber (CIG) filter was used as the denuded backup filter, the denuder efficiency for removing gaseous organics that could be adsorbed by the CIG filter was only about 30%. EC values were found to differ by a factor of about two depending on the charring correction method. Influence of the peak inert mode temperature was evaluated based on the summer samples. The EC value was found to continuously decrease with the peak inert mode temperature. Premature evolution of light absorbing carbon began when the peak inert mode temperature was increased from 580 to 650 °C; when further increased to 800 °C, the OC and EC split frequently occurred in the He mode, and the last OC peak was characterized by the overlapping of two separate peaks. The discrepancy between EC values defined by different temperature protocols was larger for Beijing carbonaceous aerosol compared with North America and Europe, perhaps due to the higher concentration of brown carbon in Beijing aerosol.

[Effect of ambulatory supervised cardiac training on arterial hypertension in patients with coronary artery disease and arterial hypertension].

PubMed

Kałka, Dariusz; Sobieszczańska, Małgorzata; Marciniak, Wojciech; Popielewicz-Kautz, Aleksandra; Markuszewski, Leszek; Chorebała, Arkadiusz; Korzeniowska, Joanna; Janczak, Jacek; Adamus, Jerzy

2007-01-01

Arterial hypertension is one of the most common health problems occurring in highly developed countries. It was proved that long-term and regular physical activity results in hypotensive effect. A goal of the present study was to assess an influence of six-month ambulatory cardiac rehabilitation on arterial pressure level in patients with coronary artery disease and hypertension as well as analysis of correlation between pressure values alterations and intensity of cardiac training. A study group comprised 103 patients (mean age: 61.2 +/- 0.8 years) manifesting coronary artery disease accompanied by arterial hypertension. A control group constituted 39 normotensive patients with coronary artery disease (mean age: 59.4 +/- 1.3 years). The both observed groups differ from each other only with values of left ventricle mass index and drug regimen established at least three months prior to the follow-up onset. During the rehabilitation cycle, no treatment corrections were made and no new preparations were added. The all patients were enrolled to the six-month cardiac rehabilitation program. The program comprised 45-minute training with cycle ergometer, three times a week, and generally improving gym exercises, two times a week. The analyses concerned systolic and diastolic pressure values, measured just before each training (resting pressure) and just after peak exercise interval (peak pressure), at the beginning and at the end of the rehabilitation cycle. At the initial stage, the patient group with hypertension demonstrated the higher pressure values (resting and peak), as compared with the control group. Cardiac rehabilitation performed in the examined patients caused a statistically significant reduction of the mean resting pressure, both systolic (p < 0.01) and diastolic (p < 0.01). As to the mean peak pressure in this group, systolic diminished slightly (NS), but diastolic was reduced significantly (p < 0.01). In the control group, after six-month rehabilitation the values appeared to be lowered insignificantly in relation to systolic and diastolic resting pressure, likewise diastolic peak pressure, and contrarily systolic peak pressure increased slightly. Assessing an interrelation between the final outcome of the rehabilitation program, expressed as delta of arterial pressure, and terminal training workload and delta of training workload, only for delta of systolic pressure and final training workload, a positive correlation of statistical significance was found out, which is considered an implication of physiological reaction against an increase of training workload. Long-term and regular cardiac training induced the larger alterations of pressure values in the patients with hypertension, as compared with the normotensive patients. A positive effect of cardiac rehabilitation on arterial pressure level in the hypertensive patients was found to be independent of the training intensity.

Velocity and bottom-stress measurements in the bottom boundary layer, outer Norton Sound, Alaska.

USGS Publications Warehouse

Cacchione, D.A.; Drake, D.E.; Wiberg, P.

1982-01-01

We have used long-term measurements of near-bottom velocities at four heights above the sea floor in Norton Sound, Alaska, to compute hourly values of shear velocity u., roughness and bottom-drag coefficient. Maximum sediment resuspension and transport, predicted for periods when the computed value of u. exceeds a critical level, occur during peak tidal currents associated with spring tides. The fortnightly variation in u. is correlated with a distinct nepheloid layer that intensifies and thickens during spring tides and diminishes and thins during neap tides. The passage of a storm near the end of the experiment caused significantly higher u. values than those found during fair weather.-from Authros

Brain natriuretic peptide in cardiac surgery--influence of aprotinin.

PubMed

Bail, Dorothee H L; Ziemer, Gerhard

2009-08-14

This study was designed to examine plasma concentrations of BNP and its correlations to the perioperative course in patients' cardiopulmonary bypass (CPB). Sixty-five patients with coronary artery disease (CAD) undergoing CPB were examined. Pre, intra and postoperative BNP values and hemodynamic parameters were measured. The BNP peak correlated neither with any hemodynamic parameters, with the duration of aortic cross-clamping (AXCL), of the operation or with CBP-time, nor with the use of catecholamines. BNP values were significantly higher with the perioperative use of aprotinin. These results confirm that the metabolism and biological activity of BNP may differ following CPB. An additional reason for increased postoperative BNP values might be the use of aprotinin.

Preliminary evaluation of magnitude and frequency of floods in selected small drainage basins in Ohio

USGS Publications Warehouse

Kolva, J.R.

1985-01-01

A previous study of flood magitudes and frequencies in Ohio concluded that existing regionalized flood equations may not be adequate for estimating peak flows in small basins that are heavily forested, surface mined, or located in northwestern Ohio. In order to provide a large data base for improving estimation of flood peaks in these basins, 30 crest-stage gages were installed in 1977, in cooperation with the Ohio Department of Transportation, to provide a 10-year record of flood data The study area consists of two distinct parts: Northwestern Ohio, which contains 8 sites, and southern and eastern Ohio, which contains 22 sites in small forested or surface-mined drainage basins. Basin characteristics were determined for all 30 sites for 1978 conditions. Annual peaks were recorded or estimated for all 30 sites for water years 1978-82; an additional year of peak discharges was available at four sites. The 2-year (Q2) and 5-year (Q5) flood peaks were determined from these annual peaks.Q2 and Q5 values also were calculated using published regionalized regression equations for Ohio. The ratios of the observed to predicted 2-year (R2) and 5-year (R5) values were then calculated. This study found that observed flood peaks aree lower than estimated peaks by a significant amount in surface-mined basins. The average ratios of observed to predicted R2 values are 0.51 for basins with more than 40 percent surface-minded land, and 0.68 for sites with any surface-mined land. The average R5 value is 0.55 for sites with more than 40 percent surface-minded land, and 0.61 for sites with any surface-mined land. Estimated flood peaks from forested basins agree with the observed values fairly well. R2 values average 0.87 for sites with 20 percent or more forested land, but no surface-mined land, and R5 values average 0.96. If all sites with more than 20 percent forested land and some surface-mined land are considered, R2 the values average 0.86, and the R5 values average 0.82.

Essays in Energy Economics

NASA Astrophysics Data System (ADS)

Spurlock, Cecily Anna

In this dissertation I explore two aspects of the economics of energy. The first focuses on consumer behavior, while the second focuses on market structure and firm behavior. In the first chapter, I demonstrate evidence of loss aversion in the behavior of households on two critical peak pricing experimental tariffs while participating in the California Statewide Pricing Pilot. I develop a model of loss aversion over electricity expenditure from which I derive two sets of testable predictions. First, I show that when there is a higher probability that a household is in the loss domain of their value function for the bill period, the more strongly they cut back peak consumption. Second, when prices are such that households are close to the kink in their value function - and would otherwise have expenditure skewed into the loss domain---I show evidence of disproportionate clustering at the kink. In essence this means that the occurrence of critical peak days did not only result in a reduction of peak consumption on that day, but also spilled over to further reduction of peak consumption on regular peak days for several weeks thereafter. This was similarly true when temperatures were high during high priced periods. This form of demand adjustment resulted in households experiencing bill-period expenditures equal to what they would have paid on the standard non-dynamic pricing tariff at a disproportionate rate. This higher number of bill periods with equal expenditure displaced bill periods in which they otherwise would have paid more than if they were on standard pricing. In the second chapter, I explore the effects of two simultaneous changes in minimum energy efficiency and Energy Star standards for clothes washers. Adapting the Mussa and Rosen (1978) and Ronnen (1991) second-degree price discrimination model, I demonstrate that clothes washer prices and menus adjusted to the new standards in patterns consistent with a market in which firms had been price discriminating. In particular, I show evidence of discontinuous price drops at the time the standards were imposed, driven largely by mid low efficiency segments of the market. The price discrimination model predicts this result. On the other hand, under perfect competition, prices should increase for these market segments. Additionally, new models proliferated in the highest efficiency market segment following the standard changes. Finally, I show that firms appeared to use different adaptation strategies at the two instances of the standards changing.

Stress Distribution in Splinted and Unsplinted Implant-Supported Maxillary Overdentures: A 3D Finite Element Analysis.

PubMed

Geramy, Allahyar; Habibzadeh, Sareh

2018-02-01

This study was accomplished to assess the biomechanical state of splinting in implant-supported maxillary overdentures. Two models of maxillary overdentures were designed in SolidWorks 2011. The first model included 4 separate implants and ball abutments, whereas the second one included 4 splinted implants connected with a bar. Evaluation was performed in ANSYS Workbench software with 200 N load applied at the molar-premolar region, bilaterally. The maximum equivalent stress and strain (von Mises) was recorded and analyzed along a path between the implants in the crestal bone and the prosthetic attachments. First model presented higher values of strain in prosthetic attachment and higher values of von Mises stress in crestal bone. The second model presented higher stress concentration in the gingival tissue of premolar area (near the bar), whereas the peak stress values were reported within the most distal part of the soft tissue support of the prosthesis in the first model (unsplinted). Splinting maxillary overdentures implants is associated with significant lower stress levels in the surrounding bone tissue.

Counting missing values in a metabolite-intensity data set for measuring the analytical performance of a metabolomics platform.

PubMed

Huan, Tao; Li, Liang

2015-01-20

Metabolomics requires quantitative comparison of individual metabolites present in an entire sample set. Unfortunately, missing intensity values in one or more samples are very common. Because missing values can have a profound influence on metabolomic results, the extent of missing values found in a metabolomic data set should be treated as an important parameter for measuring the analytical performance of a technique. In this work, we report a study on the scope of missing values and a robust method of filling the missing values in a chemical isotope labeling (CIL) LC-MS metabolomics platform. Unlike conventional LC-MS, CIL LC-MS quantifies the concentration differences of individual metabolites in two comparative samples based on the mass spectral peak intensity ratio of a peak pair from a mixture of differentially labeled samples. We show that this peak-pair feature can be explored as a unique means of extracting metabolite intensity information from raw mass spectra. In our approach, a peak-pair peaking algorithm, IsoMS, is initially used to process the LC-MS data set to generate a CSV file or table that contains metabolite ID and peak ratio information (i.e., metabolite-intensity table). A zero-fill program, freely available from MyCompoundID.org , is developed to automatically find a missing value in the CSV file and go back to the raw LC-MS data to find the peak pair and, then, calculate the intensity ratio and enter the ratio value into the table. Most of the missing values are found to be low abundance peak pairs. We demonstrate the performance of this method in analyzing an experimental and technical replicate data set of human urine metabolome. Furthermore, we propose a standardized approach of counting missing values in a replicate data set as a way of gauging the extent of missing values in a metabolomics platform. Finally, we illustrate that applying the zero-fill program, in conjunction with dansylation CIL LC-MS, can lead to a marked improvement in finding significant metabolites that differentiate bladder cancer patients and their controls in a metabolomics study of 109 subjects.

Expression of Geochemical Controls on Water Quality in Loch Vale, Rocky Mountain National Park

NASA Astrophysics Data System (ADS)

Podzorski, H.; Navarre-Sitchler, A.; Stets, E.; Clow, D. W.

2017-12-01

Relationships between concentrations of rock weathering products and discharge provide insight into the interactions between climate and solute dynamics. This concentration-discharge (C-Q) relationship is especially interesting in high alpine regions, due to their susceptibility to changes in the timing and magnitude of snowmelt. Previous studies looking at C-Q relationships have concluded that concentrations of conservative solutes remain relatively constant as discharge varies; however, these results may be due to relatively small sample sizes, especially at higher discharge values. Using water chemistry data collected regularly by the U.S. Geological Survey from Loch Vale, a high-elevation catchment in Rocky Mountain National Park, C-Q relationships were examined to determine possible geochemical controls on stream solute concentrations. A record of over 20 years of C-Q data resulted in a pattern that shows little variation in conservative solute concentrations during base flow and larger variations in concentrations around peak discharge. This observed pattern is consistent with accumulation of solutes in pore water during base flow, which are then flushed out and diluted by snowmelt. Further evidence of this flushing out mechanism is found in patterns of hysteresis that are present in annual C-Q relationships. Before peak discharge, concentrations of weathering products are higher than after peak discharge at similar values of discharge. Based on these observations, we hypothesize that the geochemical processes controlling stream chemistry vary by season. During the winter, solute concentrations are transport-limited due to slow subsurface flushing resulting in concentrations that are effectively constant and close to equilibrium. During the spring and summer, concentrations drop sharply after peak discharge due to a combination of dilution and reaction-limited processes under conditions with faster subsurface flow and continued snowmelt. This study provides insight into seasonal geochemical controls on conservative solute concentrations that can be overlooked with small, or seasonally biased, data sets.

Daily Peak Load Forecasting of Next Day using Weather Distribution and Comparison Value of Each Nearby Date Data

NASA Astrophysics Data System (ADS)

Ito, Shigenobu; Yukita, Kazuto; Goto, Yasuyuki; Ichiyanagi, Katsuhiro; Nakano, Hiroyuki

By the development of industry, in recent years; dependence to electric energy is growing year by year. Therefore, reliable electric power supply is in need. However, to stock a huge amount of electric energy is very difficult. Also, there is a necessity to keep balance between the demand and supply, which changes hour after hour. Consequently, to supply the high quality and highly dependable electric power supply, economically, and with high efficiency, there is a need to forecast the movement of the electric power demand carefully in advance. And using that forecast as the source, supply and demand management plan should be made. Thus load forecasting is said to be an important job among demand investment of electric power companies. So far, forecasting method using Fuzzy logic, Neural Net Work, Regression model has been suggested for the development of forecasting accuracy. Those forecasting accuracy is in a high level. But to invest electric power in higher accuracy more economically, a new forecasting method with higher accuracy is needed. In this paper, to develop the forecasting accuracy of the former methods, the daily peak load forecasting method using the weather distribution of highest and lowest temperatures, and comparison value of each nearby date data is suggested.

Capillary gas chromatographic separation of organic bases using a pH-adjusted basic water stationary phase.

PubMed

Darko, Ernest; Thurbide, Kevin B

2016-09-23

The use of a pH-adjusted water stationary phase for analyzing organic bases in capillary gas chromatography (GC) is demonstrated. Through modifying the phase to typical values near pH 11.5, it is found that various organic bases are readily eluted and separated. Conversely, at the normal pH 7 operating level, they are not. Sodium hydroxide is found to be a much more stable base than ammonium hydroxide for altering the pH due to the higher volatility and evaporation of the latter. In the basic condition, such analytes are not ionized and are observed to produce good peak shapes even for injected masses down to about 20ng. By comparison, analyses on a conventional non-polar capillary GC column yield more peak tailing and only analyte masses of 1μg or higher are normally observed. Through carefully altering the pH, it is also found that the selectivity between analytes can be potentially further enhanced if their respective pKa values differ sufficiently. The analysis of different pharmaceutical and petroleum samples containing organic bases is demonstrated. Results indicate that this approach can potentially offer unique and beneficial selectivity in such analyses. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental study of 2-layer regenerators using Mn-Fe-Si-P materials

NASA Astrophysics Data System (ADS)

Christiaanse, T. V.; Trevizoli, P. V.; Misra, Sumohan; Carroll, Colman; van Asten, David; Zhang, Lian; Teyber, R.; Govindappa, P.; Niknia, I.; Rowe, A.

2018-03-01

This work describes an experimental study of a two layer active magnetic regenerator with varying transition temperature spacing. The transition temperature of the materials is based on the specific heat peak of the materials. A transition temperature based on the average of the heating and cooling curves at zero Tesla field value is used to refer to the materials throughout this paper. This study uses five Mn-Fe-Si-P materials with transition temperatures of 294.6 K, 292.3 K, 290.7 K, 282.5 K and 281.4 K. Six different regenerators are tested. A reference configuration is tested using the 294.6 K material a hot side layer and with a second passive layer of lead spheres as cold side layer. Followed by four configurations that use the same 294.6 K material as hot side layer, but where each configuration uses a different cold side material. For the second active layer the materials are used in sequence; 292.3 K, 290.7 K, 282.5 K and 281.4K. Lastly, a sixth configuration uses the 292.3 K and 282.5 K materials. For each configuration, the temperature span is measured for rejection temperatures from 40 °C to 9 °C and at 0 W and 2 W applied load. Experimental results for temperature span and exergetic cooling power are compared based on the differences from the reference configuration. Materials are analysed based on material performance metrics such as peak adiabatic temperature change, peak entropy change and RCP(s) values. For the cases considered, a closer transition temperature spacing generally gives a greater temperature span and exergetic cooling power than further spaced materials, even when the combined materials have comparatively lower performance metrics. When two materials with higher RCP(s) values with large transition temperature spacing are compared to materials with lower RCP(s) values but, closer transition temperature spacing a higher exergetic cooling power and temperature span is found for the latter.

The statistical overlap theory of chromatography using power law (fractal) statistics.

PubMed

Schure, Mark R; Davis, Joe M

2011-12-30

The chromatographic dimensionality was recently proposed as a measure of retention time spacing based on a power law (fractal) distribution. Using this model, a statistical overlap theory (SOT) for chromatographic peaks is developed that estimates the number of peak maxima as a function of the chromatographic dimension, saturation and scale. Power law models exhibit a threshold region whereby below a critical saturation value no loss of peak maxima due to peak fusion occurs as saturation increases. At moderate saturation, behavior is similar to the random (Poisson) peak model. At still higher saturation, the power law model shows loss of peaks nearly independent of the scale and dimension of the model. The physicochemical meaning of the power law scale parameter is discussed and shown to be equal to the Boltzmann-weighted free energy of transfer over the scale limits. The scale is discussed. Small scale range (small β) is shown to generate more uniform chromatograms. Large scale range chromatograms (large β) are shown to give occasional large excursions of retention times; this is a property of power laws where "wild" behavior is noted to occasionally occur. Both cases are shown to be useful depending on the chromatographic saturation. A scale-invariant model of the SOT shows very simple relationships between the fraction of peak maxima and the saturation, peak width and number of theoretical plates. These equations provide much insight into separations which follow power law statistics. Copyright © 2011 Elsevier B.V. All rights reserved.

How to use your peak flow meter

MedlinePlus

Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

Crystal-Site-Selective Spectrum of Fe3BO6 by Synchrotron Mössbauer Diffraction with Pure Nuclear Bragg Scattering

NASA Astrophysics Data System (ADS)

Nakamura, Shin; Mitsui, Takaya; Fujiwara, Kosuke; Ikeda, Naoshi; Kurokuzu, Masayuki; Shimomura, Susumu

2017-08-01

We have succeeded in obtaining the crystal-site-selective spectra of the collinear antiferromagnet Fe3BO6 using a synchrotron Mössbauer diffractometer with pure nuclear Bragg scattering at SPring-8 BL11XU. Well-resolved 300, 500, and 700 reflection spectra, having asymmetric line shapes owing to the higher-order interference effect between the nuclear energy levels, were quantitatively analyzed using a formula based on the dynamical theory of diffraction. Reasonable hyperfine parameters were obtained. The intensity ratio of Fe1 to Fe2 subspectra is in accordance with the nuclear structure factor. However, when the spectrum is measured at the peak position of the rocking curve (very near the Bragg position), the value of the center shift deviates from its intrinsic value. This is also due to the dynamical effect of γ-ray diffraction. To avoid this problem, it is necessary to use diffraction angles near the foot of the rocking curve, approximately 0.02° apart from the peak position.

Noninvasive Uterine Electromyography For Prediction of Preterm Delivery*

PubMed Central

UCOVNIK, Miha L; MANER, William L.; CHAMBLISS, Linda R.; BLUMRICK, Richard; BALDUCCI, James; NOVAK-ANTOLIC, Ziva; GARFIELD, Robert E.

2011-01-01

Objective Power spectrum (PS) of uterine electromyography (EMG) can identify true labor. EMG propagation velocity (PV) to diagnose labor has not been reported. The objective was to compare uterine EMG against current methods to predict preterm delivery. Study design EMG was recorded in 116 patients (preterm labor, n=20; preterm non-labor, n=68; term labor, n=22; term non-labor, n=6). Student’s t-test was used to compare EMG values for labor vs. non-labor (P<0.05 significant). Predictive values of EMG, Bishop-score, contractions on tocogram, and transvaginal cervical length were calculated using receiver-operator-characteristics analysis. Results PV was higher in preterm and term labor compared with non-labor (P<0.001). Combined PV and PS peak frequency predicted preterm delivery within 7 days with area-under-the-curve (AUC) = 0.96. Bishop score, contractions, and cervical length had AUC of 0.72, 0.67, and 0.54. Conclusions Uterine EMG PV and PS peak frequency more accurately identify true preterm labor than clinical methods. PMID:21145033

Simultaneous Planck, Swift, and Fermi Observations of X-ray and Gamma-ray Selected Blazars

NASA Technical Reports Server (NTRS)

Giommi, P.; Polenta, G.; Laehteenmaeki, A.; Thompson, D. J.; Capalbi, M.; Cutini, S.; Gasparrini, D.; Gonzalez, Nuevo, J.; Leon-Tavares, J.; Lopez-Caniego, M.;

The arterial baroreflex effectiveness index in risk stratification of chronic heart failure patients who are candidates for cardiac resynchronization therapy.

PubMed

Fernandes Serôdio, João; Martins Oliveira, Mário; Matoso Laranjo, Sérgio; Tavares, Cristiano; Silva Cunha, Pedro; Abreu, Ana; Branco, Luísa; Alves, Sandra; Rocha, Isabel; Cruz Ferreira, Rui

2016-06-01

Baroreflex function is an independent marker of prognosis in heart failure (HF). However, little is known about its relation to response to cardiac resynchronization therapy (CRT). The aim of this study is to assess arterial baroreflex function in HF patients who are candidates for CRT. The study population consisted of 25 patients with indication for CRT, aged 65±10 years, NYHA functional class ≥III in 52%, QRS width 159±15 ms, left ventricular ejection fraction (LVEF) 29±5%, left ventricular end-systolic volume (LVESV) 150±48 ml, B-type natriuretic peptide (BNP) 357±270 pg/ml, and peak oxygen consumption (peak VO2) 18.4±5.0 ml/kg/min. An orthostatic tilt test was performed to assess the baroreflex effectiveness index (BEI) by the sequence method. This group was compared with 15 age-matched healthy individuals. HF patients showed a significantly depressed BEI during tilt (31±12% vs. 49±18%, p=0.001). A lower BEI was associated with higher BNP (p=0.038), lower peak VO2 (p=0.048), and higher LVESV (p=0.031). By applying a cut-off value of 25% for BEI, two clusters of patients were identified: lower risk cluster (BEI >25%) QRS 153 ms, LVESV 129 ml, BNP 146 pg/ml, peak VO2 19.0 ml/kg/min; and higher risk cluster (IEB ≤25%) QRS 167 ms, LVESV 189 ml, BNP 590 pg/ml, peak VO2 16.2 ml/kg/min. Candidates for CRT show depressed arterial baroreflex function. Lower BEI was observed in high-risk HF patients. Baroreflex function correlated closely with other clinical HF parameters. Therefore, BEI may improve risk stratification in HF patients undergoing CRT. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

The Effect of the Ionosphere on Radiowave Signals and Systems Performance Based on Ionospheric Effects Symposium Held on 1-3 May 1990

DTIC Science & Technology

1990-05-03

winter and a minimum in summer ; in contrast, at sunspot maximum the seasonal peaks tend to occur around the equinoxes and the minima in summer . ’riis is...more clearly seen in Figures 4(b) ahnd 4(c). Note that around sunspot maximum the summer noon value may be less than the summer midnight value. (3) The...seasonal variation of the midnight values show summer peaks and winter minima with high values near the peaks of the sunspot cycles and low values

Self-preservation and structural transition of gas hydrates during dissociation below the ice point: an in situ study using Raman spectroscopy

PubMed Central

Zhong, Jin-Rong; Zeng, Xin-Yang; Zhou, Feng-He; Ran, Qi-Dong; Sun, Chang-Yu; Zhong, Rui-Qin; Yang, Lan-Ying; Chen, Guang-Jin; Koh, Carolyn A.

2016-01-01

The hydrate structure type and dissociation behavior for pure methane and methane-ethane hydrates at temperatures below the ice point and atmospheric pressure were investigated using in situ Raman spectroscopic analysis. The self-preservation effect of sI methane hydrate is significant at lower temperatures (268.15 to 270.15 K), as determined by the stable C-H region Raman peaks and AL/AS value (Ratio of total peak area corresponding to occupancies of guest molecules in large cavities to small cavities) being around 3.0. However, it was reduced at higher temperatures (271.15 K and 272.15 K), as shown from the dramatic change in Raman spectra and fluctuations in AL/AS values. The self-preservation effect for methane-ethane double hydrate is observed at temperatures lower than 271.15 K. The structure transition from sI to sII occurred during the methane-ethane hydrate decomposition process, which was clearly identified by the shift in peak positions and the change in relative peak intensities at temperatures from 269.15 K to 271.15 K. Further investigation shows that the selectivity for self-preservation of methane over ethane leads to the structure transition; this kind of selectivity increases with decreasing temperature. This work provides new insight into the kinetic behavior of hydrate dissociation below the ice point. PMID:27941857

Self-preservation and structural transition of gas hydrates during dissociation below the ice point: an in situ study using Raman spectroscopy.

PubMed

Zhong, Jin-Rong; Zeng, Xin-Yang; Zhou, Feng-He; Ran, Qi-Dong; Sun, Chang-Yu; Zhong, Rui-Qin; Yang, Lan-Ying; Chen, Guang-Jin; Koh, Carolyn A

2016-12-12

The hydrate structure type and dissociation behavior for pure methane and methane-ethane hydrates at temperatures below the ice point and atmospheric pressure were investigated using in situ Raman spectroscopic analysis. The self-preservation effect of sI methane hydrate is significant at lower temperatures (268.15 to 270.15 K), as determined by the stable C-H region Raman peaks and A L /A S value (Ratio of total peak area corresponding to occupancies of guest molecules in large cavities to small cavities) being around 3.0. However, it was reduced at higher temperatures (271.15 K and 272.15 K), as shown from the dramatic change in Raman spectra and fluctuations in A L /A S values. The self-preservation effect for methane-ethane double hydrate is observed at temperatures lower than 271.15 K. The structure transition from sI to sII occurred during the methane-ethane hydrate decomposition process, which was clearly identified by the shift in peak positions and the change in relative peak intensities at temperatures from 269.15 K to 271.15 K. Further investigation shows that the selectivity for self-preservation of methane over ethane leads to the structure transition; this kind of selectivity increases with decreasing temperature. This work provides new insight into the kinetic behavior of hydrate dissociation below the ice point.

Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips.

PubMed

Galvão, Marília Regalado; Caldas, Sergei Godeiro Fernandes Rabelo; Bagnato, Vanderlei Salvador; de Souza Rastelli, Alessandra Nara; de Andrade, Marcelo Ferrarezi

2013-01-01

The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm(-1)) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm(-1)). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey's test, with a significance level set at 5%. The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness.

Evaluation of degree of conversion and hardness of dental composites photo-activated with different light guide tips

PubMed Central

Galvão, Marília Regalado; Caldas, Sergei Godeiro Fernandes Rabelo; Bagnato, Vanderlei Salvador; de Souza Rastelli, Alessandra Nara; de Andrade, Marcelo Ferrarezi

2013-01-01

Objective: The aim of this study was to evaluate the degree of conversion and hardness of different composite resins, photo-activated for 40 s with two different light guide tips, fiber optic and polymer. Methods: Five specimens were made for each group evaluated. The percentage of unreacted carbon double bonds (% C═C) was determined from the ratio of absorbance intensities of aliphatic C═C (peak at 1637 cm−1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm−1). The Vickers hardness measurements were performed in a universal testing machine. A 50 gf load was used and the indenter with a dwell time of 30 seconds. The degree of conversion and hardness mean values were analyzed separately by ANOVA and Tukey’s test, with a significance level set at 5%. Results: The mean values of degree of conversion for the polymer and fiber optic light guide tip were statistically different (P<.001). The hardness mean values were statistically different among the light guide tips (P<.001), but also there was difference between top and bottom surfaces (P<.001). Conclusions: The results showed that the resins photo-activated with the fiber optic light guide tip promoted higher values for degree of conversion and hardness. PMID:23407620

Spectral investigation of somatotropin for different pH values

NASA Astrophysics Data System (ADS)

Otero de Joshi, Virginia; Gil, Herminia; Contreras, Silvia; Joshi, Narahari V.; Hernandez, Luis

1996-04-01

Spectral investigations of absorbance in deep ultra-violet region (from 200 nm to 350 nm) of (STM) was carried out for different pH values. On the high energy side the peak is located at 195 nm which is generally attributed to peptide bonds. This peak, as expected, does not show any shift with pH value (4.3 to 10.8). A rather broad peak is spread in the region from 200 nm to 240 nm which could be the superposition of the peaks corresponding to the absorption due to (alpha) helix and (beta) structure. This peak shows a red shift as pH value increases. The same hormone was glycated by a conventional method and the process was estimated with the absorption spectra. The results are discussed in the light of nonenzymatic glycation. It was found that glycation mucus somatotropin resistant towards the denaturation process.

Characterization of pituitary function with emphasis on GH secretion in the chronic fatigue syndrome.

PubMed

Moorkens, G; Berwaerts, J; Wynants, H; Abs, R

2000-07-01

Previous studies have revealed that hormonal disturbances may accompany the chronic fatigue syndrome (CFS). Changes in the secretion of the pituitary-adrenal axis have been demonstrated, as well as abnormalities in the GH-IGF-I axis. However, data have not always been well characterized and were sometimes conflicting. The small number of CFS patients investigated in earlier studies may have played a role in the interpretation of the results. Hormonal testing was performed in 73 nonobese CFS patients and nonobese 21 age-and gender-matched healthy controls. We investigated GH, ACTH and cortisol responses to insulin-induced hypoglycaemia. In a subgroup of patients arginine and clonidine stimulation for GH was also performed. Nocturnal secretion of GH, ACTH and cortisol were determined. Serum levels of IGF-I, prolactin, TSH, and free thyroxine were also measured. Visceral fat mass was assessed by CT scanning. GH response to insulin induced hypoglycaemia assessed by peak value (17.0 +/- 13.1 microg/l vs. 22. 1 +/- 9.8 microg/l; P = 0.01) and by AUC (450.0 +/- 361.3 microg/l vs. 672.3 +/- 393.0 microg/l; P = 0.002) was significantly decreased in CFS patients vs. controls. Nocturnal GH secretion assessed by GH peak value (5.4 +/- 3.7 vs. 9.0 +/- 5.1 microg/l; P = 0.44) and by AUC (34.4 +/- 20.2 vs. 67.4 +/- 43.1; P = 0.045) was also significantly impaired in CFS patients. Arginine and clonidine administration showed no differences in GH secretion between CFS patients and controls. In the CFS group, GH peak values were significantly higher after ITT than after arginine (P = 0.017) or clonidine (P = 0.001). No differences in serum IGF-I levels were found between CFS patients and controls. Except for a significantly lower nocturnal cortisol peak value, no differences were found in ACTH and cortisol secretion between CFS patients and controls. Significantly higher serum prolactin levels (7.4 +/- 4.7 microg/l vs. 4.4 +/- 1.3 microg/l; P = 0.004) and significantly higher serum TSH levels (1.6 +/- 1.0 mU/l vs. 1.0 +/- 0.4 mU/l; P = 0.011) were found in CFS patients. Serum free thyroxine was comparable in both groups. Visceral fat mass was significantly higher in CFS patients (86.6 +/- 34.9 cm2 vs. 51.5 +/- 15.7 cm2; P < 0.001). We observed a significant impairment of GH response during insulin-induced hypoglycaemia and a low nocturnal GH secretion in CFS patients. These changes did, however, not lead to different concentrations in serum IGF-I. The clinical expression of this inadequate GH secretion can thus be questioned, although the alteration in body composition may be related to this relative GH deficiency. Significantly increased prolactin and TSH levels were found when compared to controls. These findings give support to the hypothesis of a decreased dopaminergic tone in CFS. Further investigations are required in order to identify specific adaptations within the neurotransmitter system in CFS and to determine the clinical importance of the impaired GH homeostasis.

Analysis of WBV on standing and seated passengers during off-peak operation in KL monorail

NASA Astrophysics Data System (ADS)

Hasnan, K.; Bakhsh, Q.; Ahmed, A.; Ali, D.; Jamali, A. R.

2018-03-01

In this study, the Whole-Body Vibration (WBV) was analyzed on the standing and seated passenger during off-peak operating hours when train was on the track. The experiments were conducted on two car train at one constant location (bogie-1, which is near to driver’s cabin) during downward direction from KL sentral station towards Titiwangsa station. The aim of this study was to analyze that, in which posture of passenger’s exposures the maximum level of WBV. Since, one passenger was performed the whole journey in standing posture whereas, the other passenger was in seated posture. The result obtained from experiments for the RMS accelerations (Arms), maximum acceleration (Amax) and minimum acceleration (Amin) during the trip. As per standard ISO 2631-1, the daily vibration exposure (A8), Vibration Dose value (VDV) and Crest Factor (CF) of this trip for both standing and sitting orientations were calculated. Results shows that the seated passenger was exposed to longer periods of continuous vibration as compared to the standing passenger. Whereas, the Vibration Dose value (VDV) value was greater than the action value as per ISO 2631-1 and within the limit values. The study concluded that whole body vibration transmitted towards both passengers either standing or seated during their journey. But in overall results comparison of both orientations, the seated passengers gained higher vibration than the standing one.

CFD-Predicted Tile Heating Bump Factors Due to Tile Overlay Repairs

NASA Technical Reports Server (NTRS)

Lessard, Victor R.

2006-01-01

A Computational Fluid Dynamics investigation of the Orbiter's Tile Overlay Repair (TOR) is performed to assess the aeroheating Damage Assessment Team's (DAT) existing heating correlation method for protuberance interference heating on the surrounding thermal protection system. Aerothermodynamic heating analyses are performed for TORs at the design reference damage locations body points 1800 and 1075 for a Mach 17.9 and a=39deg STS-107 flight trajectory point with laminar flow. Six different cases are considered. The computed peak heating bump factor on the surrounding tiles are below the DAT's heating bump factor values for smooth tile cases. However, for the uneven tiles cases the peak interference heating is shown to be considerably higher than the existing correlation prediction.

DFT calculations of graphene monolayer in presence of Fe dopant and vacancy

NASA Astrophysics Data System (ADS)

Ostovari, Fatemeh; Hasanpoori, Marziyeh; Abbasnejad, Mohaddeseh; Salehi, Mohammad Ali

2018-07-01

In the present work, the effects of Fe doping and vacancies on the electronic, magnetic and optical properties of graphene are studied by density functional theory based calculations. The conductive behavior is revealed for the various defected graphene by means of electronic density of states. However, defected structures show different magnetic and optical properties compared to those of pure one. The ferromagnetic phase is the most probable phase by substituting Fe atoms and vacancies at AA sublattice of graphene. The optical properties of impure graphene differ from pure graphene under illumination with parallel polarization of electric field, whereas for perpendicular polarization it remains unchanged. In presence of defect and under parallel polarization of light, the static dielectric constant rises strongly and the maximum peak of Im ε(ω) shows red shift relative to pure graphene. Moreover, the maximum absorption peak gets broaden in the visible to infrared region at the same condition and the magnitude and related energy of peaks shift to higher value in the EELS spectra. Furthermore, the results show that the maximum values of refractive index and reflectivity spectra increase rapidly and represent the red and blue shifts; respectively. Generally; substituting the C atom with Fe has more effect on magnetic and optical properties relative to the C vacancies.

Effective Ion Mobility Peak Width as a New Isomeric Descriptor for the Untargeted Analysis of Complex Mixtures Using Ion Mobility-Mass Spectrometry

NASA Astrophysics Data System (ADS)

Farenc, Mathilde; Paupy, Benoit; Marceau, Sabrina; Riches, Eleanor; Afonso, Carlos; Giusti, Pierre

2017-07-01

Ion mobility coupled with mass spectrometry was proven to be an efficient way to characterize complex mixtures such as petroleum samples. However, the identification of isomeric species is difficult owing to the molecular complexity of petroleum and no availability of standard molecules. This paper proposes a new simple indicator to estimate the isomeric content of highly complex mixtures. This indicator is based on the full width at half maximum (FWHM) of the extracted ion mobility peak measured in millisecond or square angstrom that is corrected for instrumental factors such as ion diffusion. This value can be easily obtained without precisely identifying the number of isomeric species under the ion mobility peaks. Considering the Boduszynski model, the ion mobility profile for a particular elemental composition is expected to be a continuum of various isomeric species. The drift time-dependent fragmentation profile was studied and confirmed this hypothesis, a continuous evolution of the fragmentation profile showing that the larger alkyl chain species were detected at higher drift time values. This new indicator was proven to be a fast and efficient method to compare vacuum gas oils for which no difference was found using other analytical techniques.

Associations between seasonal meteorological conditions and the daily step count of adults in Yokohama, Japan: Results of year-round pedometer measurements in a large population.

PubMed

Hino, Kimihiro; Lee, Jung Su; Asami, Yasushi

2017-12-01

People's year-round interpersonal step count variations according to meteorological conditions are not fully understood, because complete year-round data from a sufficient sample of the general population are difficult to acquire. This study examined the associations between meteorological conditions and objectively measured step counts using year-round data collected from a large cohort ( N  = 24,625) in Yokohama, Japan from April 2015 to March 2016. Two-piece linear regression analysis was used to examine the associations between the monthly median daily step count and three meteorological indices (mean values of temperature, temperature-humidity index (THI), and net effective temperature (NET)). The number of steps per day peaked at temperatures between 19.4 and 20.7 °C. At lower temperatures, the increase in steps per day was between 46.4 and 52.5 steps per 1 °C increase. At temperatures higher than those at which step counts peaked, the decrease in steps per day was between 98.0 and 187.9 per 1 °C increase. Furthermore, these effects were more obvious in elderly than non-elderly persons in both sexes. A similar tendency was seen when using THI and NET instead of temperature. Among the three meteorological indices, the highest R 2 value with step counts was observed with THI in all four groups. Both high and low meteorological indices discourage people from walking and higher values of the indices adversely affect step count more than lower values, particularly among the elderly. Among the three indices assessed, THI best explains the seasonal fluctuations in step counts.

Synthesis, Spectral Characterization, Thermal and Optical Studies of Novel Complexes: 4-(Dimethylamino)benzylidene-4-acetamideaniline and 4-(Dimethylamino)benzylidene-4-nitroaniline.

PubMed

Neupane, Umesh; Rai, R N

2017-11-01

The phase diagram representing solid-liquid equilibrium of entire range of composition and thermodynamic studies of two binary organic systems of 4-dimethylaminobenzaldehyde (DMAB) with two NLO active compounds, p-aminoacetanilide (PAA) and p-nitroaniline (PNA), have been studied by solid state synthetic route. Both systems are independently forming a new entity called intermolecular complex (IMC) and two eutectics on either side of intermolecular complexes. The various thermodynamic parameters such as heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions of IMCs and eutectics were calculated using the heat of fusion values. The TGA and DTA studies were performed to understand the physico-chemical, thermal behavior and unique identity of newly synthesized organic complexes, 4-(dimethylamino)benzylidene-4-acetamideaniline (DMABPAA) and 4-(dimethylamino)benzylidene-4-nitroaniline (DMABPNA), and their respective enthalpy of fusion values were found to be 30.01 and 37.26 kJ mol - 1 . The higher melting point of both the novel complexes than their parent's compounds reveal the strong molecular interaction between parent components to yield the complex. The FTIR spectral analysis predicts the disappearance of aldehyde peaks of DMAB and NH 2 peaks of PAA and PNA while the appearance of entirely new peaks than that of parent's compounds are the supportive for the formation of new molecular entities. These findings are further supported by FTNMR spectrum studies by observation of disappearance of proton peak of aldehyde of DMAB and amine peaks of PAA and PNA rather formation of new imine proton peak or peaks were observed. The appearance of new peaks in Powder XRD of complexes than those of parent components is further indicative for the formation of complexes. The absorption spectrum of DMABPAA and DMABPNA showed intra-molecular charge-transfer (ICT) excited state absorption at 258 and 241 nm, respectively. Both the IMCs, DMABPAA and DMABPNA, show strong fluorescence with quantum yield 0.66 and 0.93, respectively, in methanol solution.

Evaluation of Transmitral Pressure Gradients in the Intraoperative Echocardiographic Diagnosis of Mitral Stenosis after Mitral Valve Repair

PubMed Central

Segal, Scott; Fox, John A.; Eltzschig, Holger K.; Shernan, Stanton K.

2011-01-01

Objective Acute mitral stenosis (MS) following mitral valve (MV) repair is a rare but severe complication. We hypothesize that intraoperative echocardiography can be utilized to diagnose iatrogenic MS immediately after MV repair. Methods The medical records of 552 consecutive patients undergoing MV repair at a single institution were reviewed. Post-cardiopulmonary bypass peak and mean transmitral pressure gradients (TMPG), and pressure half time (PHT) were obtained from intraoperative transesophageal echocardiographic (TEE) examinations in each patient. Results Nine patients (9/552 = 1.6%) received a reoperation for primary MS, prior to hospital discharge. Interestingly, all of these patients already showed intraoperative post-CPB mean and peak TMPGs that were significantly higher compared to values for those who did not: 10.7±4.8 mmHg vs 2.9±1.6 mmHg; p<0.0001 and 22.9±7.9 mmHg vs 7.6±3.7 mmHg; p<0.0001, respectively. However, PHT varied considerably (87±37 ms; range: 20–439 ms) within the entire population, and only weakly predicted the requirement for reoperation (113±56 vs. 87±37 ms, p = 0.034). Receiver operating characteristic curves showed strong discriminating ability for mean gradients (AUC = 0.993) and peak gradients (area under the curve, AUC = 0.996), but poor performance for PHT (AUC = 0.640). A value of ≥7 mmHg for mean, and ≥17 mmHg for peak TMPG, best separated patients who required reoperation for MS from those who did not. Conclusions Intraoperative TEE diagnosis of a peak TMPG ≥17 mmHg or mean TMPG ≥7 mmHg immediately following CPB are suggestive of clinically relevant MS after MV repair. PMID:22087230

Syn-extensional plutonism and peak metamorphism in the albion-raft river-grouse creek metamorphic core complex

USGS Publications Warehouse

Strickland, A.; Miller, E.L.; Wooden, J.L.; Kozdon, R.; Valley, J.W.

2011-01-01

The Cassia plutonic complex (CPC) is a group of variably deformed, Oligocene granitic plutons exposed in the lower plate of the Albion-Raft River- Grouse Creek (ARG) metamorphic core complex of Idaho and Utah. The plutons range from granodiorite to garnet-bearing, leucogranite, and during intrusion, sillimanite- grade peak metamorphism and ductile attenuation occurred in the country rocks and normal-sense, amphibolite-grade deformation took place along the Middle Mountain shear zone. U-Pb zircon geochronology from three variably deformed plutons exposed in the lower plate of the ARG metamorphic core complex revealed that each zircon is comprised of inherited cores (dominantly late Archean) and Oligocene igneous overgrowths. Within each pluton, a spread of concordant ages from the Oligocene zircon overgrowths is interpreted as zircon recycling within a long-lived magmatic system. The plutons of the CPC have very low negative whole rock ??Nd values of -26 to -35, and initial Sr values of 0.714 to 0.718, consistent with an ancient, crustal source. Oxygen isotope ratios of the Oligocene zircon overgrowths from the CPC have an average ??18O value of 5.40 ?? 0.63 permil (2SD, n = 65) with a slight trend towards higher ??18O values through time. The ??18O values of the inherited cores of the zircons are more variable at 5.93 ?? 1.51 permil (2SD, n = 29). Therefore, we interpret the plutons of the CPC as derived, at least in part, from melting Archean crust based on the isotope geochemistry. In situ partial melting of the exposed Archean basement that was intruded by the Oligocene plutons of the CPC is excluded as the source for the CPC based on field relationships, age and geochemistry. Correlations between Ti and Hf concentrations in zircons from the CPC suggest that the magmatic system may have become hotter (higher Ti concentration in zircon) and less evolved (lower Hf in zircon concentration) through time. Therefore, the CPC represents prolonged or episodic magmatism system (32-25 Ma), and the intrusions were each accompanied by sillimanite-grade deformation and extension. The Oligocene magmatism and peak metamorphism preserved in the ARG metamorphic core complex are likely related to regional trends in mantle-derived magmatism that led to protracted heating, melting and mobilization of the deeper crust.

Assessment and interpretation of aerobic fitness in children and adolescents.

PubMed

Armstrong, N; Welsman, J R

1994-01-01

Our understanding of the development of children and adolescents' aerobic fitness is limited by ethical considerations and methodological constraints. Protocols, apparatus, and criteria of maximal effort used with adults are often unsuitable for use with children. In normal children and adolescents, peak VO2 increases with growth and maturation, although there are indications that girls' peak VO2 may level off around 14 years of age. Males exhibit higher values of peak VO2 than females, and the sex difference increases as they progress through adolescence. The difference between males and females has been attributed to the boys' greater muscle mass and hemoglobin concentration. It appears that boys experience an adolescent growth spurt in peak VO2, which reaches a maximum gain near the time of PHV, but data are insufficient to offer any generalization for girls. Peak VO2 has usually been expressed in relation to body mass, and with this convention it appears that boys' values are consistent throughout the developmental period, whereas girls' values decrease as they get older. This type of analysis may, however, have clouded our understanding of growth and maturational changes in peak VO2, and scaling for differences in body size may provide further clarification. If differences are shown where none were previously thought to exist, then physiological explanations must be sought. Methodological issues have also hindered the understanding of how children's blood lactate responses to exercise develop. The actual lactate level recorded during an exercise test is influenced by the site of sampling and the blood handling and assay techniques. Valid interstudy comparisons can only be made where similar procedures have been employed. In general, children demonstrate lower blood lactate levels at peak VO2 than adults, although individual variation is wide. Therefore the use of blood lactate measures to confirm the attainment of peak VO2 cannot be supported. Exercise at the same relative submaximal intensity elicits a lower blood lactate in children than in adults, but interpretation and identification of developmental and maturational patterns of response are limited by the use of different testing conditions and reference points (e.g., lactate threshold and fixed level reference points). There is growing evidence that the 2.5 mM reference level should be used in preference to the 4.0 mM level, as the adult criterion occurs close to maximal exercise in many children and adolescents. Explanations for child-adult differences in blood lactate responses to exercise are difficult to elucidate.(ABSTRACT TRUNCATED AT 400 WORDS)

Exposure of the general public due to wireless LAN applications in public places.

PubMed

Schmid, G; Preiner, P; Lager, D; Uberbacher, R; Georg, R

2007-01-01

The typical exposure caused by wireless LAN applications in public areas has been investigated in a variety of scenarios. Small-sized (internet café) and large-scale (airport) indoor scenarios as well as outdoor scenarios in the environment of access points (AP) supplying for residential areas and public places were considered. The exposure assessment was carried out by numerical GTD/UTD computations based on optical wave propagation, as well as by verifying frequency selective measurements in the considered scenarios under real life conditions. In the small-sized indoor scenario the maximum temporal peak values of power density, spatially averaged over body dimensions, were found to be lower than 20 mW/m(2), corresponding to 0.2% of the reference level according to the European Council Recommendation 1999/519/EC. Local peak values of power density might be 1-2 orders of magnitude higher, spatial and time-averaged values for usual data traffic conditions might be 2-3 orders of magnitude lower, depending on the actual data traffic. In the considered outdoor scenarios, exposure was several orders of magnitude lower than in indoor scenarios due to the usually larger distances to the AP antennas.

Study on Energy Absorption Capacity of Steel-Polyester Hybrid Fiber Reinforced Concrete Under Uni-axial Compression

NASA Astrophysics Data System (ADS)

Chella Gifta, C.; Prabavathy, S.

2018-05-01

This work presents the energy absorption capacity of hybrid fiber reinforced concrete made with hooked end steel fibers (0.5 and 0.75%) and straight polyester fibers (0.5, 0.8, 1.0 and 2.0%). Compressive toughness (energy absorption capacity) under uni-axial compression was evaluated on 100 × 200 mm size cylindrical specimens with varying steel and polyester fiber content. Efficiency of the hybrid fiber reinforcement is studied with respect to fiber type, size and volume fractions in this investigation. The vertical displacement under uni-axial compression was measured under the applied loads and the load-deformation curves were plotted. From these curves the toughness values were calculated and the results were compared with steel and polyester as individual fibers. The hybridization of 0.5% steel + 0.5% polyester performed well in post peak region due to the addition of polyester fibers with steel fibers and the energy absorption value was 23% greater than 0.5% steel FRC. Peak stress values were also higher in hybrid series than single fiber and based on the results it is concluded that hybrid fiber reinforcement improves the toughness characteristics of concrete without affecting workability.

The GALAH survey: stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity

NASA Astrophysics Data System (ADS)

Quillen, Alice C.; De Silva, Gayandhi; Sharma, Sanjib; Hayden, Michael; Freeman, Ken; Bland-Hawthorn, Joss; Žerjal, Maruša; Asplund, Martin; Buder, Sven; D'Orazi, Valentina; Duong, Ly; Kos, Janez; Lin, Jane; Lind, Karin; Martell, Sarah; Schlesinger, Katharine; Simpson, Jeffrey D.; Zucker, Daniel B.; Zwitter, Tomaz; Anguiano, Borja; Carollo, Daniela; Casagrande, Luca; Cotar, Klemen; Cottrell, Peter L.; Ireland, Michael; Kafle, Prajwal R.; Horner, Jonathan; Lewis, Geraint F.; Nataf, David M.; Ting, Yuan-Sen; Watson, Fred; Wittenmyer, Rob; Wyse, Rosemary

2018-07-01

Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos(HIgh Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.

Raman bandshape analysis of the symmetric bending vibration in liquid chloroform

NASA Astrophysics Data System (ADS)

Yuan, P.; Schwartz, M.

In order to determine whether accurate rotational diffusion coefficients in liquids may be determined from the bandshapes of isotopically broadened vibrational peaks, we have investigated the isotropic and anisotropic Raman spectra of the ν 3( A1), CCl 3 symmetric bending, vibration in CHCl 3 as a function of temperature in the liquid phase. The spectral lineshapes were fitted by a model containing four Lorentzian/Gaussian summation bands with relative peak intensities equal to the relative abundances of the four isotopic combinations and frequency displacements constrained to values measured in the matrix infrared spectrum. The calculated room temperature perpendicular diffusion coefficient, D⊥ (25°C) = 8.310 10 s -1, was within the range of values reported from Raman measurements on the ν 1, symmetric carbon-hydrogen stretching, vibration, but was somewhat lower than published results from NMR relaxation time measurements, T1( 2D), on CDCl 3, and from dielectric relaxation. The activation energy, Ea( D⊥), determined from the ν 3 bandshape measurements was 30% higher than the average value from the NMR and dielectric studies. The deviation is believed to result from the sensitivity of this quantity to the fractional Lorentzian character of the fitting functions.

A comparison of practical assessment methods to determine treadmill, cycle and elliptical ergometer VO2peak

PubMed Central

Mays, Ryan J.; Boér, Nicholas F.; Mealey, Lisa M.; Kim, Kevin H.; Goss, Fredric L.

2015-01-01

This investigation compared estimated and predicted peak oxygen consumption (VO2peak) and maximal heart rate (HRmax) among the treadmill, cycle ergometer and elliptical ergometer. Seventeen women (mean ± SE: 21.9 ± .3 yrs) exercised to exhaustion on all modalities. ACSM metabolic equations were used to estimate VO2peak. Digital displays on the elliptical ergometer were used to estimate VO2peak. Two individual linear regression methods were used to predict VO2peak: 1) two steady state heart rate (HR) responses up to 85% of age-predicted HRmax, and 2) multiple steady state/non-steady state HR responses up to 85% of age-predicted HRmax. Estimated VO2peak for the treadmill (46.3 ± 1.3 ml · kg−1 · min−1) and the elliptical ergometer (44.4 ± 1.0 ml · kg−1 · min−1) did not differ. The cycle ergometer estimated VO2peak (36.5 ± 1.0 ml · kg−1 · min−1) was lower (p < .001) than the estimated VO2peak values for the treadmill and elliptical ergometer. Elliptical ergometer VO2peak predicted from steady state (51.4 ± .8 ml · kg−1 · min−1) and steady state/non-steady state (50.3 ± 2.0 ml · kg−1 · min−1) models were higher than estimated elliptical ergometer VO2peak, p < .01. HRmax and estimates of VO2peak were similar between the treadmill and elliptical ergometer, thus cross-modal exercise prescriptions may be generated. The use of digital display estimates of submaximal oxygen uptake for the elliptical ergometer may not be an accurate method for predicting VO2peak. Health-fitness professionals should use caution when utilizing submaximal elliptical ergometer digital display estimates to predict VO2peak. PMID:20393357

Evolution of robust circadian clocks in Drosophila melanogaster populations reared in constant dark for over 330 generations

NASA Astrophysics Data System (ADS)

Shindey, Radhika; Varma, Vishwanath; Nikhil, K. L.; Sharma, Vijay Kumar

2016-10-01

Robustness is considered to be an important feature of biological systems which may evolve when the functionality of a trait is associated with higher fitness across multiple environmental conditions. Thus, the ability to maintain stable biological phenotypes across environments is thought to be of adaptive value. Previously, we have reported higher intrinsic activity levels (activity levels of free-running rhythm in constant darkness) and power of rhythm (as assessed by amplitude of the periodogram) in Drosophila melanogaster populations (stocks) reared in constant darkness (DD stocks) as compared to those reared in constant light (LL stocks) and 12:12-h light-dark cycles (LD stocks) for over 19 years (˜330 generations). In the current study, we intended to examine whether the enhanced levels of activity observed in DD stocks persist under various environments such as photoperiods, ambient temperatures, non-24-h light-dark (LD) cycles, and semi-natural conditions (SN). We found that DD stocks largely retain their phenotype of enhanced activity levels across most of the above-mentioned environments suggesting the evolution of robust circadian clocks in DD stocks. Furthermore, we compared the peak activity levels of the three stocks across different environmental conditions relative to their peaks in constant darkness and found that the change in peak activity levels upon entrainment was not significantly different across the three stocks for any of the examined environmental conditions. This suggests that the enhancement of activity levels in DD stocks is not due to differential sensitivity to environment. Thus, these results suggest that rearing in constant darkness (DD) leads to evolution of robust circadian clocks suggesting a possible adaptive value of possessing such rhythms under constant dark environments.

Effect of the laser and light-emitting diode (LED) phototherapy on midpalatal suture bone formation after rapid maxilla expansion: a Raman spectroscopy analysis.

PubMed

Rosa, Cristiane Becher; Habib, Fernando Antonio Lima; de Araújo, Telma Martins; Aragão, Juliana Silveira; Gomes, Rafael Soares; Barbosa, Artur Felipe Santos; Silveira, Landulfo; Pinheiro, Antonio L B

2014-05-01

The aim of this study was to analyze the effect of laser or light-emitting diode (LED) phototherapy on the bone formation at the midpalatal suture after rapid maxilla expansion. Twenty young adult male rats were divided into four groups with 8 days of experimental time: group 1, no treatment; group 2, expansion; group 3, expansion and laser irradiation; and group 4, expansion and LED irradiation. In groups 3 and 4, light irradiation was in the first, third, and fifth experimental days. In all groups, the expansion was accomplished with a helicoid 0.020" stainless steel orthodontic spring. A diode laser (λ780 nm, 70 mW, spot of 0.04 cm(2), t = 257 s, spatial average energy fluence (SAEF) of 18 J/cm(2)) or a LED (λ850 nm, 150 mW ± 10 mW, spot of 0.5 cm(2), t = 120 s, SAEF of 18 J/cm(2)) were used. The samples were analyzed by Raman spectroscopy carried out at midpalatal suture and at the cortical area close to the suture. Two Raman shifts were analyzed: ∼ 960 (phosphate hydroxyapatite) and ∼ 1,450 cm(-1) (lipids and protein). Data was submitted to statistical analysis. Significant statistical difference (p ≤ 0.05) was found in the hydroxyapatite (CHA) peaks among the expansion group and the expansion and laser or LED groups. The LED group presented higher mean peak values of CHA. No statistical differences were found between the treated groups as for collagen deposition, although LED also presented higher mean peak values. The results of this study using Raman spectral analysis indicate that laser and LED light irradiation improves deposition of CHA in the midpalatal suture after orthopedic expansion.

Evolution of robust circadian clocks in Drosophila melanogaster populations reared in constant dark for over 330 generations.

PubMed

Shindey, Radhika; Varma, Vishwanath; Nikhil, K L; Sharma, Vijay Kumar

2016-10-01

Robustness is considered to be an important feature of biological systems which may evolve when the functionality of a trait is associated with higher fitness across multiple environmental conditions. Thus, the ability to maintain stable biological phenotypes across environments is thought to be of adaptive value. Previously, we have reported higher intrinsic activity levels (activity levels of free-running rhythm in constant darkness) and power of rhythm (as assessed by amplitude of the periodogram) in Drosophila melanogaster populations (stocks) reared in constant darkness (DD stocks) as compared to those reared in constant light (LL stocks) and 12:12-h light-dark cycles (LD stocks) for over 19 years (∼330 generations). In the current study, we intended to examine whether the enhanced levels of activity observed in DD stocks persist under various environments such as photoperiods, ambient temperatures, non-24-h light-dark (LD) cycles, and semi-natural conditions (SN). We found that DD stocks largely retain their phenotype of enhanced activity levels across most of the above-mentioned environments suggesting the evolution of robust circadian clocks in DD stocks. Furthermore, we compared the peak activity levels of the three stocks across different environmental conditions relative to their peaks in constant darkness and found that the change in peak activity levels upon entrainment was not significantly different across the three stocks for any of the examined environmental conditions. This suggests that the enhancement of activity levels in DD stocks is not due to differential sensitivity to environment. Thus, these results suggest that rearing in constant darkness (DD) leads to evolution of robust circadian clocks suggesting a possible adaptive value of possessing such rhythms under constant dark environments.

Sensory and Quality Evaluation of Traditional Compared with Power Ultrasound Processed Corn (Zea Mays) Tortilla Chips.

PubMed

Janve, Bhaskar; Yang, Wade; Sims, Charles

2015-06-01

Power ultrasound reduces the traditional corn steeping time from 18 to 1.5 h during tortilla chips dough (masa) processing. This study sought to examine consumer (n = 99) acceptability and quality of tortilla chips made from the masa by traditional compared with ultrasonic methods. Overall appearance, flavor, and texture acceptability scores were evaluated using a 9-point hedonic scale. The baked chips (process intermediate) before and after frying (finished product) were analyzed using a texture analyzer and machine vision. The texture values were determined using the 3-point bend test using breaking force gradient (BFG), peak breaking force (PBF), and breaking distance (BD). The fracturing properties determined by the crisp fracture support rig using fracture force gradient (FFG), peak fracture force (PFF), and fracture distance (FD). The machine vision evaluated the total surface area, lightness (L), color difference (ΔE), Hue (°h), and Chroma (C*). The results were evaluated by analysis of variance and means were separated using Tukey's test. Machine vision values of L, °h, were higher (P < 0.05) and ΔE was lower (P < 0.05) for fried and L, °h were significantly (P < 0.05) higher for baked chips produced from ultra-sonication as compare to traditional. Baked chips texture for ultra-sonication was significantly higher (P < 0.05) on BFG, BPD, PFF, and FD. Fried tortilla chips texture were higher significantly (P < 0.05) in BFG and PFF for ultra-sonication than traditional processing. However, the instrumental differences were not detected in sensory analysis, concluding possibility of power ultrasound as potential tortilla chips processing aid. © 2015 Institute of Food Technologists®

Effect of dopants on the TL response of the new LiF:Mg,Cu,Ag material

NASA Astrophysics Data System (ADS)

Yahyaabadi, A.; Torkzadeh, F.; Rezaei-Ochbelagh, D.; Hosseini Pooya, M.

2018-07-01

The new TL LiF:Mg,Cu,Ag material was prepared and investigated in this study. The TL intensity of LiF:Mg,Cu,Ag is strongly dependent on the concentration of dopants and the preparation procedure. Any small change in these factors can cause alterations in TL response. In this study, the influence of Cu and Ag concentrations on the response of the LiF:Mg,Cu,Ag sample was investigated and showed that the height of the low, main and high temperature peaks changes with Ag concentration. Their intensities increased with increasing Ag concentration to a maximum value and decreased with higher Ag concentration. It was also found that Cu concentration less than 0.05 mol% influences the maximum peak height and TL intensity. The optimum Cu and Ag concentrations were found to be 0.05 and 0.1 mol% at 1005 °C QT, respectively. The role of dopants in LiF:Mg,Cu,Ag material was also investigated. The results showed that presence of three dopants is important for having material with sensitivity higher than LiF:Mg,Ti. The Mg dopant plays a crucial role in the formation of the trapping center and the position of the main dosimetric peak.

Design of a fast echo matching algorithm to reduce crosstalk with Doppler shifts in ultrasonic ranging

NASA Astrophysics Data System (ADS)

Liu, Lei; Guo, Rui; Wu, Jun-an

2017-02-01

Crosstalk is a main factor for wrong distance measurement by ultrasonic sensors, and this problem becomes more difficult to deal with under Doppler effects. In this paper, crosstalk reduction with Doppler shifts on small platforms is focused on, and a fast echo matching algorithm (FEMA) is proposed on the basis of chaotic sequences and pulse coding technology, then verified through applying it to match practical echoes. Finally, we introduce how to select both better mapping methods for chaotic sequences, and algorithm parameters for higher achievable maximum of cross-correlation peaks. The results indicate the following: logistic mapping is preferred to generate good chaotic sequences, with high autocorrelation even when the length is very limited; FEMA can not only match echoes and calculate distance accurately with an error degree mostly below 5%, but also generates nearly the same calculation cost level for static or kinematic ranging, much lower than that by direct Doppler compensation (DDC) with the same frequency compensation step; The sensitivity to threshold value selection and performance of FEMA depend significantly on the achievable maximum of cross-correlation peaks, and a higher peak is preferred, which can be considered as a criterion for algorithm parameter optimization under practical conditions.

Effect of annealing temperature and dopant concentration on the thermoluminescence sensitivity in LiF:Mg,Cu,Ag material.

PubMed

Yahyaabadi, Akram; Torkzadeh, Falamarz; Rezaei Ochbelagh, Dariush; Hosseini Pooya, Seyed Mahdi

2018-04-24

LiF:Mg,Cu,Ag is a new dosimetry material that is similar to LiF:Mg,Cu,P in terms of dosimetric properties. The effect of the annealing temperature in the range of 200 to 350°C on the thermoluminescence (TL) sensitivity and the glow curve structure of this material at different concentrations of silver (Ag) was investigated. It has been demonstrated that the optimum values of the annealing temperature and the Ag concentration are 240°C and 0.1 mol% for better sensitivity, respectively. The TL intensity decreases at annealing temperatures lower than 240°C or higher than 240°C, reaching a minimum at 300°C and then again increases for various Ag concentrations. It was observed that the glow curve structure altered and the area under the low temperature peak as well as the area under the main dosimetric peak decreased with increasing annealing temperature. The position of the main dosimetric peak moved in the direction of higher temperatures, but at 320 and 350°C annealing temperatures, it shifted to lower temperatures. It was also observed that the TL sensitivity could partially be recovered by a combined annealing procedure. Copyright © 2018 John Wiley & Sons, Ltd.

Predicting Solar Cycle 24 Using a Geomagnetic Precursor Pair

NASA Technical Reports Server (NTRS)

Pesnell, W. Dean

2014-01-01

We describe using Ap and F(10.7) as a geomagnetic-precursor pair to predict the amplitude of Solar Cycle 24. The precursor is created by using F(10.7) to remove the direct solar-activity component of Ap. Four peaks are seen in the precursor function during the decline of Solar Cycle 23. A recurrence index that is generated by a local correlation of Ap is then used to determine which peak is the correct precursor. The earliest peak is the most prominent but coincides with high levels of non-recurrent solar activity associated with the intense solar activity of October and November 2003. The second and third peaks coincide with some recurrent activity on the Sun and show that a weak cycle precursor closely following a period of strong solar activity may be difficult to resolve. A fourth peak, which appears in early 2008 and has recurrent activity similar to precursors of earlier solar cycles, appears to be the "true" precursor peak for Solar Cycle 24 and predicts the smallest amplitude for Solar Cycle 24. To determine the timing of peak activity it is noted that the average time between the precursor peak and the following maximum is approximately equal to 6.4 years. Hence, Solar Cycle 24 would peak during 2014. Several effects contribute to the smaller prediction when compared with other geomagnetic-precursor predictions. During Solar Cycle 23 the correlation between sunspot number and F(10.7) shows that F(10.7) is higher than the equivalent sunspot number over most of the cycle, implying that the sunspot number underestimates the solar-activity component described by F(10.7). During 2003 the correlation between aa and Ap shows that aa is 10 % higher than the value predicted from Ap, leading to an overestimate of the aa precursor for that year. However, the most important difference is the lack of recurrent activity in the first three peaks and the presence of significant recurrent activity in the fourth. While the prediction is for an amplitude of Solar Cycle 24 of 65 +/- 20 in smoothed sunspot number, a below-average amplitude for Solar Cycle 24, with maximum at 2014.5+/-0.5, we conclude that Solar Cycle 24 will be no stronger than average and could be much weaker than average.

Force-time profile differences in the delivery of simulated toggle-recoil spinal manipulation by students, instructors, and field doctors of chiropractic.

PubMed

DeVocht, James W; Owens, Edward F; Gudavalli, Maruti Ram; Strazewski, John; Bhogal, Ramneek; Xia, Ting

2013-01-01

The objectives of this study were to examine the force-time profiles of toggle recoil using an instrumented simulator to objectively measure and evaluate students' skill to determine if they become quicker and use less force during the course of their training and to compare them to course instructors and to field doctors of chiropractic (DCs) who use this specific technique in their practices. A load cell was placed within a toggle recoil training device. The preload, speed, and magnitude of the toggle recoil thrusts were measured from 60 students, 2 instructors, and 77 DCs (ie, who use the toggle recoil technique in their regular practice). Student data were collected 3 times during their toggle course (after first exposure, at midterm, and at course end.) Thrusts showed a dual-peak force-time profile not previously described in other forms of spinal manipulation. There was a wide range of values for each quantity measured within and between all 3 subject groups. The median peak load for students decreased over the course of their class, but they became slower. Field doctors were faster than students or instructors and delivered higher peak loads. Toggle recoil thrusts into a dropping mechanism varied based upon subject and amount of time practicing the task. As students progressed through the class, speed reduced as they increased control to lower peak loads. In the group studies, field DCs applied higher forces and were faster than both students and instructors. There appears to be a unique 2-peak feature of the force-time plot that is unique to toggle recoil manipulation with a drop mechanism. Copyright © 2013 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Influence of hydrogenated oil as cocoa butter replacers in the development of sugar-free compound chocolates: Use of inulin as stabilizing agent.

PubMed

Rodriguez Furlán, Laura T; Baracco, Yanina; Lecot, Javier; Zaritzky, Noemi; Campderrós, Mercedes E

2017-02-15

The effect of the addition of inulin as a surfactant or stability agent on white compound chocolate sweetened with sucralose and Stevia was studied. Samples were stored at 7, 15 and 30°C during 100days and the influence of inulin on rheological properties, sensorial attributes, shelf-life, physical properties such as melting, crystallization and blooming were analyzed. The shelf-life of the compound chocolate with the incorporation of inulin was higher than the control sample without replacement. Compound chocolate with inulin at 10%w/w showed a dense matrix structure, reducing the size and number of fat crystals formed during storage; furthermore they presented higher values of brightness and WI. This chocolate also showed less fracturability and improved thermal properties. DSC studies revealed increased values of onset and peak temperatures and enthalpy of melting of the polymorphic form V, at higher storage temperatures, achieving greater stability against degradation processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of exercise blood pressure measured by technician and an automated system.

PubMed

Garcia-Gregory, J A; Jackson, A S; Studeville, J; Squires, W G; Owen, C A

1984-05-01

We evaluated the automated system Blood Pressure Measuring System (BPMS) developed by NASA on 277 adult males who elected to have a treadmill test as part of their annual physical. The BPMS uses acoustic transduction with a computer-assisted ECG gating to detect nonsynchronous noise. The BPMS readings were compared to pressures simultaneously measured by trained technicians. For all stages of work, BPMS readings were higher for systolic and lower for diastolic than technician readings. At peak stages of work, BPMS systolic pressures were about 20 mmHg higher than technician readings. Within each 3-min workstage, BPMS readings were found to be more inconsistent than technician readings. The standard errors of measurement for BPMS were from two to three times higher than technician values. These data showed automated blood pressure readings were significantly different than technician values and subject to more random fluctuations. These findings demonstrate the need to view exercise blood pressure measured by automated systems with caution.

RoboPol: the optical polarization of gamma-ray-loud and gamma-ray-quiet blazars

NASA Astrophysics Data System (ADS)

Angelakis, E.; Hovatta, T.; Blinov, D.; Pavlidou, V.; Kiehlmann, S.; Myserlis, I.; Böttcher, M.; Mao, P.; Panopoulou, G. V.; Liodakis, I.; King, O. G.; Baloković, M.; Kus, A.; Kylafis, N.; Mahabal, A.; Marecki, A.; Paleologou, E.; Papadakis, I.; Papamastorakis, I.; Pazderski, E.; Pearson, T. J.; Prabhudesai, S.; Ramaprakash, A. N.; Readhead, A. C. S.; Reig, P.; Tassis, K.; Urry, M.; Zensus, J. A.

2016-12-01

We present average R-band optopolarimetric data, as well as variability parameters, from the first and second RoboPol observing season. We investigate whether gamma-ray-loud and gamma-ray-quiet blazars exhibit systematic differences in their optical polarization properties. We find that gamma-ray-loud blazars have a systematically higher polarization fraction (0.092) than gamma-ray-quiet blazars (0.031), with the hypothesis of the two samples being drawn from the same distribution of polarization fractions being rejected at the 3σ level. We have not found any evidence that this discrepancy is related to differences in the redshift distribution, rest-frame R-band luminosity density, or the source classification. The median polarization fraction versus synchrotron-peak-frequency plot shows an envelope implying that high-synchrotron-peaked sources have a smaller range of median polarization fractions concentrated around lower values. Our gamma-ray-quiet sources show similar median polarization fractions although they are all low-synchrotron-peaked. We also find that the randomness of the polarization angle depends on the synchrotron peak frequency. For high-synchrotron-peaked sources, it tends to concentrate around preferred directions while for low-synchrotron-peaked sources, it is more variable and less likely to have a preferred direction. We propose a scenario which mediates efficient particle acceleration in shocks and increases the helical B-field component immediately downstream of the shock.

On the determination of the post-irradiation time from the glow curve of TLD-100.

PubMed

Weinstein, M; German, U; Dubinsky, S; Alfassi, Z B

2003-01-01

The ratio of peak 3 to the sum of peaks 4 + 5 in TLD-100 was measured for various pre-irradiation and post-irradiation time periods, under conditions characteristic of routine personal dosimetry. It was confirmed that the value of this ratio depends only on the elapsed time between the prior readout and the present one, independent of the moment when the irradiation took place during the total time interval (storage time). This effect indicates that fading of peak 3 seems to be due mainly to changes in the unoccupied traps, and not to decay of trapped charges, being almost independent of the presence of electrons or holes in the traps. This observation leads to the conclusion that the suggestions in the past to use the decay of peak 3 in TLD-100 for the measurement of the elapsed time between irradiation and readout may have been wrong. On the other hand, the decay of peak 2 can be used to measure the elapsed time from irradiation, since the rate of decay is different when related to pre-irradiation and post-irradiation times, indicating a much higher decay rate of the trapped charges (Randall-Wilkins decay). However, because of the fast decay rate of peak 2, its use for determination of the elapsed time since irradiation is of little practical significance.

Follow-up chest radiographic findings in patients with MERS-CoV after recovery

PubMed Central

Das, Karuna M; Lee, Edward Y; Singh, Rajvir; Enani, Mushira A; Al Dossari, Khalid; Van Gorkom, Klaus; Larsson, Sven G; Langer, Ruth D

2017-01-01

Purpose: To evaluate the follow-up chest radiographic findings in patients with Middle East respiratory syndrome coronavirus (MERS-CoV) who were discharged from the hospital following improved clinical symptoms. Materials and Methods: Thirty-six consecutive patients (9 men, 27 women; age range 21–73 years, mean ± SD 42.5 ± 14.5 years) with confirmed MERS-CoV underwent follow-up chest radiographs after recovery from MERS-CoV. The 36 chest radiographs were obtained at 32 to 230 days with a median follow-up of 43 days. The reviewers systemically evaluated the follow-up chest radiographs from 36 patients for lung parenchymal, airway, pleural, hilar and mediastinal abnormalities. Lung parenchyma and airways were assessed for consolidation, ground-glass opacity (GGO), nodular opacity and reticular opacity (i.e., fibrosis). Follow-up chest radiographs were also evaluated for pleural thickening, pleural effusion, pneumothorax and lymphadenopathy. Patients were categorized into two groups: group 1 (no evidence of lung fibrosis) and group 2 (chest radiographic evidence of lung fibrosis) for comparative analysis. Patient demographics, length of ventilations days, number of intensive care unit (ICU) admission days, chest radiographic score, chest radiographic deterioration pattern (Types 1-4) and peak lactate dehydrogenase level were compared between the two groups using the student t-test, Mann-Whitney U test and Fisher's exact test. Results: Follow-up chest radiographs were normal in 23 out of 36 (64%) patients. Among the patients with abnormal chest radiographs (13/36, 36%), the following were found: lung fibrosis in 12 (33%) patients GGO in 2 (5.5%) patients, and pleural thickening in 2 (5.5%) patients. Patients with lung fibrosis had significantly greater number of ICU admission days (19 ± 8.7 days; P value = 0.001), older age (50.6 ± 12.6 years; P value = 0.02), higher chest radiographic scores [10 (0-15.3); P value = 0.04] and higher peak lactate dehydrogenase levels (315-370 U/L; P value = 0.001) when compared to patients without lung fibrosis. Conclusion: Lung fibrosis may develop in a substantial number of patients who have recovered from Middle East respiratory syndrome coronavirus (MERS-CoV). Significantly greater number of ICU admission days, older age, higher chest radiographic scores, chest radiographic deterioration patterns and peak lactate dehydrogenase levels were noted in the patients with lung fibrosis on follow-up chest radiographs after recovery from MERS-CoV. PMID:29089687

Absorption spectroscopic and FTIR studies on EDA complexes between TNT (2,4,6-trinitrotoluene) with amines in DMSO and determination of the vertical electron affinity of TNT.

PubMed

Sharma, S P; Lahiri, S C

2008-06-01

TNT (2,4,6-trinitrotoluene) formed deep red 1:1 CT complexes with chromogenic agents like isopropylamine, ethylenediamine, bis(3-aminopropyl)amine and tetraethylenepentamine in DMSO. The complexes were also observed in solvents like methanol, acetone, etc. when the amines were present in large excess. The isopropylamine, complex showed three absorption peaks (at 378, 532 and 629 nm) whereas higher amines showed four peaks (at 370, 463, 532 and 629 nm). The peak at 463 nm vanished rapidly. The peak of the complexes near 530 nm required about 8-10 min to develop and the complexes were stable for about an hour but the peak slowly shifted towards 500 nm and the complexes were found to be stable for more than 24 h. The evidence of complex formation was obtained from distinct spots in HPTLC plates and from the shifts in frequencies and formation of new peaks in FTIR spectra. The peaks near 460 nm (transient) and 530 nm may be due to Janovsky reaction but could not be established. The extinction coefficients of the complexes were determined directly which enabled the accurate determination of the association constants KDA with TNT and amines in stoichiometric ratios. The results were verified using iterative method. The quantification of TNT was made using epsilon value of the complex with ethylenediamine. The vertical electron affinity (EA) of TNT was calculated using the method suggested by Mulliken.

Detection of liver cancer and abnormal liver tissue by Raman spectroscopy and fluorescence

NASA Astrophysics Data System (ADS)

Li, Xiaozhou; Ding, Jianhua; Zhang, Xiujun; Lin, Junxiu; Wang, Deli

2005-01-01

In this paper, laser induced human serum Raman spectra of liver cancer are measured. The spectra differences in serum from normal people and liver disease patients are analyzed. For the typical spectrum of normal serum, there are three sharp Raman peaks and relative intensity of Raman peaks excited by 514.5nm is higher than that excited by 488.0nm. For the Raman spectrum of liver cancer serum there are no peaks or very weak Raman peaks at the same positions. Results from more than two hundred case measurements show that clinical diagnostic accuracy is 92.86%. And then, the liver fibrosis and liver cirrhosis are studied applying the technology of LIF. To liver cirrhosis, the shape of Raman peak is similar to normal and fluorescence spectrum is similar to that of liver cancer from statistic data. The experiment indicates that there is notable fluorescence difference between the abnormal and normal liver tissue and have blue shift in fluorescence peak. Except for human serum, we use rats serum for researching either. Compared with results of path al examination, we analyze the spectra of normal cases, hepatic fibrosis and hepatocirrhosis respectively in an attempt to find some difference between them. Red shift of fluorescence peak is observed with disease evolution using 514.5nm excitation of an Ar-ion laser. However, no distinct changes happen with 488.0nm excitation. These results have important reference values to explore the method of laser spectrum diagnosis.

Validation of one-mile walk equations for the estimation of aerobic fitness in British military personnel under the age of 40 years.

PubMed

Lunt, Heather; Roiz De Sa, Daniel; Roiz De Sa, Julia; Allsopp, Adrian

2013-07-01

To provide an accurate estimate of peak oxygen uptake (VO2 peak) for British Royal Navy Personnel aged between 18 and 39, comparing a gold standard treadmill based maximal exercise test with a submaximal one-mile walk test. Two hundred military personnel consented to perform a treadmill-based VO2 peak test and two one-mile walk tests round an athletics track. The estimated VO2 peak values from three different one-mile walk equations were compared to directly measured VO2 peak values from the treadmill-based test. One hundred participants formed a validation group from which a new equation was derived and the other 100 participants formed the cross-validation group. Existing equations underestimated the VO2 peak values of the fittest personnel and overestimated the VO2 peak of the least aerobically fit by between 2% and 18%. The new equation derived from the validation group has less bias, the highest correlation with the measured values (r = 0.83), and classified the most people correctly according to the Royal Navy's Fitness Test standards, producing the fewest false positives and false negatives combined (9%). The new equation will provide a more accurate estimate of VO2 peak for a British military population aged 18 to 39. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Hough transform method for track finding in center drift chamber

NASA Astrophysics Data System (ADS)

Azmi, K. A. Mohammad Kamal; Wan Abdullah, W. A. T.; Ibrahim, Zainol Abidin

2016-01-01

Hough transform is a global tracking method used which had been expected to be faster approach for tracking the circular pattern of electron moving in Center Drift Chamber (CDC), by transforming the point of hit into a circular curve. This paper present the implementation of hough transform method for the reconstruction of tracks in Center Drift Chamber (CDC) which have been generated by random number in C language programming. Result from implementation of this method shows higher peak of circle parameter value (xc,yc,rc) that indicate the similarity value of the parameter needed for circular track in CDC for charged particles in the region of CDC.

Comparative study of lesions created by high-intensity focused ultrasound using sequential discrete and continuous scanning strategies.

PubMed

Fan, Tingbo; Liu, Zhenbo; Zhang, Dong; Tang, Mengxing

2013-03-01

Lesion formation and temperature distribution induced by high-intensity focused ultrasound (HIFU) were investigated both numerically and experimentally via two energy-delivering strategies, i.e., sequential discrete and continuous scanning modes. Simulations were presented based on the combination of Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation and bioheat equation. Measurements were performed on tissue-mimicking phantoms sonicated by a 1.12-MHz single-element focused transducer working at an acoustic power of 75 W. Both the simulated and experimental results show that, in the sequential discrete mode, obvious saw-tooth-like contours could be observed for the peak temperature distribution and the lesion boundaries, with the increasing interval space between two adjacent exposure points. In the continuous scanning mode, more uniform peak temperature distributions and lesion boundaries would be produced, and the peak temperature values would decrease significantly with the increasing scanning speed. In addition, compared to the sequential discrete mode, the continuous scanning mode could achieve higher treatment efficiency (lesion area generated per second) with a lower peak temperature. The present studies suggest that the peak temperature and tissue lesion resulting from the HIFU exposure could be controlled by adjusting the transducer scanning speed, which is important for improving the HIFU treatment efficiency.

Reinforcement Probability Modulates Temporal Memory Selection and Integration Processes

PubMed Central

Matell, Matthew S.; Kurti, Allison N.

2013-01-01

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4s, light = 12s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value. PMID:23896560

Topics in electron capture by fast ions

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

Hsin, S.H.

1987-01-01

The post-collision interaction (PCI) model was applied, together with the eikonal approximation, to study the (n = 2,3) capture cross sections in p + H(ls) collisions. The results indeed improve the previous eikonal calculations for l = 0 cases, and agree quite well with present experimental data. Calculations using the strong-potential Born (SPB) approximation, with the Sil and McGuire technique, for capture into the np, nd levels are also presented. While these cross sections are smaller than cross sections for capture into the ns levels at high velocities, nevertheless the Thomas peak is clearly evident in both the absolute valuemore » m = 2, absolute value m = 1 and m = 0 magnetic substates in p + H(ls) collisions. Also calculated were corrections to the SPB using the Distorted-Wave Born formalism of Taulbjerg and Briggs. In the sense of a plane-wave Born expansion, all terms of the third Born approximation and all single switching fourth Born terms are included, but a peaking approximation is needed to reduce the calculation to tractable form. Effects of the higher terms are most visible in the valley between the Thomas peak and the forward peak. The Thomas peak is visible in the correction term, even though it includes no second Born contributions.« less

[Experimental study of Raman spectra of magnesite at 297 K and at the pressure of 0.13-1 GPa].

PubMed

Wang, Yu; Zheng, Hai-fei

2005-09-01

The experimental study of Raman spectra of magnesite has been conducted at the pressure of 967 MPa and at the temperatureof 297 K using a cubic zirconia-anvil cell. The result shows that neither phase transition nor organic substances were observed during compression, and the Raman peak of magnesite shifted to higher frequency with increasing pressure. The relation between the pressure and the Raman peak position of magnesite (1094 cm(-1)) was obtained as follows: v (cm(-1)) = 0.007 44 x P(MPa) + 1 093.3. The value of dv/dP of magnesite is greater than the previous data obtained by Gillet, which was mostly taken under the mantle pressure. And at the ambient temperature, magnesite can be used as a pressure gauge, and the relation between the pressure and Raman shift of 1 094 cm(-1) peak position is given as following: P(MPa) = 125.8 x (deltavp) 1094 + 124.7 (1094 cm(-1) < vp < 1101 cm(-1)).

Asymmetric underlap spacer layer enabled nanoscale double gate MOSFETs for design of ultra-wideband cascode amplifiers

NASA Astrophysics Data System (ADS)

Roy, Debapriya; Biswas, Abhijit

2017-10-01

Using extensive numerical analysis we investigate effects of asymmetric sidewall spacers on various device parameters of 20-nm double gate MOSFETs associated with analog/RF applications. Our studies show that the device with underlap drain-side spacer length LED of 10 nm and source-side spacer length LES of 5 nm shows improvement in terms of the peak value of transconductance efficiency, voltage gain Av, unity-gain cut-off frequency fT and maximum frequency of oscillations fMAX by 8.6%, 51.7%, 5% and 10.3%, respectively compared to the symmetric 5 nm underlap spacer device with HfO2 spacer of dielectric constant k = 22. Additionally, a higher spacer dielectric constant increases the peak Av while decreasing both peak fT and fMAX. The detailed physical insight is exploited to design a cascode amplifier which yields an ultra-wide gain bandwidth of 2.48 THz at LED = 10 nm with a SiO2 spacer.

Quantification and varietal variation of low molecular weight glutenin subunits (LMW-GS) using size exclusion chromatography.

PubMed

Dangi, Priya; Khatkar, B S

2018-03-01

Crude glutenin of four commercial wheat varieties viz. C 306, HI 977, HW 2004 and PBW 550 of diverse origin and breadmaking quality were fractionated by size-exclusion chromatography into three fractions of decreasing molecular weights. The relative quantity of peak II, containing LMW-GS specifically, varied considerably among the varieties as reflected from their discrete SEC profiles. The area % of peak II, containing protein of interest, was maximal for C 306 (22.08%) followed by PBW 550 (15.86%). The least proportion of LMW-GS were recovered from variety HW 2004 (9.68%). As the concentration of the sample extract injected to the column increased, the resolution of the peak declined in association with the slight shifting of retention time to the higher values. The best results were obtained for variety C 306 at 100 mg protein concentration with 3 M urea buffer. Consequently, the optimized conditions for purification of LMW-GS in appreciable amounts using SEC were established.

Preparation of TiN films by reactive high-power pulsed sputtering Penning discharges

NASA Astrophysics Data System (ADS)

Kimura, Takashi; Yoshida, Ryo; Mishima, Toshihiko; Azuma, Kingo; Nakao, Setsuo

2018-06-01

Titanium nitride (TiN) films are prepared by reactive high-power pulsed sputtering Penning discharges at a total pressure of 0.7 Pa and an average power of 60 W, where the nitrogen fraction is varied up to 15%. The peak value of the instantaneous power ranges between 3 and 14 kW, and the peak power density ranges between 0.3 and 1.2 kW cm‑2. The hardness of TiN films is higher than 22 GPa at the nitrogen fractions lower than 10% and it reaches 31 GPa at a nitrogen fraction of 5%. The X-ray diffraction peak of TiN(111) texture is observed for all prepared films, showing the grain size of about 10 nm. In X-ray photoelectron spectroscopy, oxygen is mainly bonded to titanium, but the intensity of the TiN bond is dominant in the entire Ti 2p spectrum. The intensity ratio of N 1s to Ti 2p ranges between 0.85 and 0.95.

Quantification of BK polyoma viruria in Japanese children and adults with hemorrhagic cystitis complicating stem cell transplantation.

PubMed

Tanaka, Kaori; Hori, Tsukasa; Hatakeyama, Naoki; Yamamoto, Masaki; Takayama, Rumiko; Yoto, Yuko; Suzuki, Nobuhiro; Hayashi, Toshiaki; Ikeda, Yukiho; Ikeda, Hiroshi; Ishida, Tadao; Tsutsumi, Hiroyuki

2008-12-01

Polyoma BK virus (BKV) is frequently found in the urine of stem cell transplantation (SCT) patients with hemorrhagic cystitis (HC), but also occurs in SCT patients without HC. How BK viruria relates to the development of HC in SCT patients, especially in children, has not yet been fully evaluated. In the present study, we analyzed the relationship of several factors including urinary BKV load to HC development in children and adults undergoing SCT. We employed a quantitative PCR assay and evaluated 37 patients (aged 9 months-62 years) of whom 12 developed HC and 25 did not. Older age was a risk factor for the development of HC; however, other factors such as sex, primary disease, type of SCT, conditioning regimen and aGVHD were not. Peak urinary BKV values in HC patients were not higher than those in non-HC patients. Severity of HC also did not correlate with urinary BKV loads. However, in some patients who secreted higher urinary BKV loads, the peak loads were closely related with the onset of HC. Higher BKV loads may be a risk factor for the development of HC in conjunction with other coexisting factors.

[Effects of electromagnetic pulse on contents of amino acids in hippocampus of rats].

PubMed

Li, Yu-hong; Wang, De-wen; Peng, Rui-yun; Li, Zi-jian; Dong, Biao; Dong, Fang-ting; Liang, Yue-qin; Hu, Wen-hua

2003-10-01

To investigate the relationship between the changes of amino acids contents in hippocampus of rats and electromagnetic pulse (EMP) exposure. Rats were decapitated and hippocampus were removed after EMP (6 x 10(4) V/m, rise time 20 ns, pulse width 30 micro s, 5 pulses in 2 minutes) irradiation, and contents of amino acids were detected with high performance liquid chromatograpy (HPLC). The contents of aspartic acid (Asp) and glutamic acid (Glu) increased significantly 0, 3, 6 h after irradiation. The peak values of Asp [(17.25 +/- 1.63) pmol/ micro l] and Glu [(13.67 +/- 0.95) pmol/ micro l] were higher than those of control [(10.56 +/- 1.50), (6.94 +/- 1.10) pmol/ micro l respectively, P < 0.05]. Then both decreased gradually and reached the normal level 24 - 48 h after irradiation. The contents of glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA) also rose after exposure, the peak value of them [(4.51 +/- 0.60), (29.85 +/- 2.70), (5.14 +/- 0.73) pmol/ micro l respectively] were higher than those of control group [(2.18 +/- 0.31), (9.88 +/- 1.47), (2.84 +/- 0.67) pmol/ micro l, P < 0.05], then recovered 48 h after irradiation. The value of Glu/GABA increased immediately after exposure (3.45 +/- 0.25, P < 0.05), then decreased 24 h (1.62 +/- 0.23, P < 0.05) and recovered 48 h after exposure. The toxic effect of excess excitatory amino acids may be partly responsible for the early retardation (within 24 h) of learning of rats.

Sex differences in kinetic and neuromuscular control during jumping and landing.

PubMed

Márquez, G; Alegre, L M; Jaén, D; Martin-Casado, L; Aguado, X

2017-03-01

In the present study, we analysed the kinetic profile together with the lower limb EMG activation pattern during a countermovement jump and its respective landing phase in males and females. Twenty subjects (10 males and 10 females) took part in the study. One experimental session was conducted in order to record kinetic and electromyographic (EMG) parameters during a countermovement jump (CMJ) and the subsequent landing phase. During the CMJ, males recorded a higher (p<0.001) performance than females in terms of jump height and power production. Stiffness values were lower in males than females due to greater centre of mass displacement during the countermovement (p<0.01). According to the EMG activity, males demonstrated greater (p<0.05) activation during the concentric phase of the jump. However, females revealed a higher co-contraction ratio in the plantar flexors during the push-off phase. During landings males showed higher (p<0.01) peak ground reaction forces (F peak ), greater (p<0.05) stiffness and a higher maximal displacement of the CoM (p<0.05) than females. EMG analysis revealed greater EMG activity in the tibialis anterior (p<0.05) and rectus femoris (p=0.05) muscles in males. Higher plantar flexor co-activation during landing has also been found in males. Our findings demonstrated different neuromuscular control in males and females during jumping and landing.

Higher-order mode photonic crystal based nanofluidic sensor

NASA Astrophysics Data System (ADS)

Peng, Wang; Chen, Youping; Ai, Wu

2017-01-01

A higher-order photonic crystal (PC) based nanofluidic sensor, which worked at 532 nm, was designed and demonstrated. A systematical and detailed method for sculpturing a PC sensor for a given peak wavelength value (PWV) and specified materials was illuminated. It was the first time that the higher order mode was used to design PC based nanofluidic sensor, and the refractive index (RI) sensitivity of this sensor had been verified with FDTD simulation software from Lumerical. The enhanced electrical field of higher order mode structure was mostly confined in the channel area, where the enhance field is wholly interacting with the analytes in the channels. The comparison of RI sensitivity between fundamental mode and higher order mode shows the RI variation of higher order mode is 124.5 nm/RIU which is much larger than the fundamental mode. The proposed PC based nanofluidic structure pioneering a novel style for future optofluidic design.

Irrigational impact of untreated and treated brewery-distillery effluent on seed germination of marigold (Tagetes erecta L.).

PubMed

Sharma, Anuradha; Malaviya, Piyush

2016-01-01

Current study presents the effect of irrigation with different concentrations (20, 40, 60, 80 and 100%) of untreated and treated brewery-distillery effluent on germination behaviour of marigold (Tagetes erecta L. var. Pusa Basanti). The 100% untreated effluent showed acidic pH (4.80) and higher values of BOD (1500.00 mg l(-1)), COD (4000.00 mg l(-1)), chloride (1742.20 mg l(-1)), TSS (900.00 mg l(-1)) as compared to that of treated effluent. Tagetes seeds were exposed to different concentrations of effluent and the results revealed maximum values of germination parameters viz., percent germination, peak value, germination value, germination index, speed of germination and vigour index at 20% untreated and 60% treated effluent concentrations, whereas the values for negative germination parameters viz., delay index, germination period and percent inhibition were minimum at 20% untreated and 60% treated effluent concentrations.

The effects of co-administration of benzhexol on the peripheral pharmacokinetics of oral levodopa in young volunteers.

PubMed

Roberts, J; Waller, D G; von Renwick, A G; O'Shea, N; Macklin, B S; Bulling, M

1996-04-01

1. The effects of benzhexol on the absorption and pharmacokinetics of an oral dose of levodopa have been studied in 10 young healthy volunteers. Subjects were given a suspension of levodopa (250 mg) 90 min after either benzhexol (5 mg) or placebo in a randomized cross over design with doses separated by at least 1 week; on each occasion carbidopa was given 1 h before and 5 h after the dose of levodopa. Soluble paracetamol and radiolabelled DTPA were given with the levodopa as markers of gastric emptying. 2. Most subjects showed two peaks in the levodopa plasma concentration-time curve on the placebo day, with the second minor peak occurring 1-2 h after the dose. After benzhexol administration all subjects showed two or more peak levodopa concentrations in plasma. Benzhexol administration caused a significant decrease in the maximum concentration (43%; P < 0.05) of the initial peak and an increase (22%; P < 0.1) in the maximum concentration of the second peak. This change in absorption profile caused by benzhexol significantly altered the ratios of the second peak compared with the initial peak for both the maximum concentrations (P < 0.02) and for the AUC values (P < 0.05). Benzhexol administration did not affect the total AUC of levodopa (7.30 +/- 1.09 vs 7.19 +/- 1.26 micrograms ml-1 h; means +/- s.d.). 3. The plasma concentration-time curves for paracetamol showed similar profiles to those for levodopa and the ratios of the peak concentrations and AUC values for the second peak compared with the initial peak were increased significantly by benzhexol administration (P < 0.05). The total AUC of paracetamol was not affected by benzhexol administration (39.4 +/- 8.2 vs 40.0 +/- 8.9 micrograms ml-1 h; mean +/- s.d.) 4. Benzhexol altered the gastric emptying profile, shown by gamma-scintigraphy, with a reduced extent of initial emptying prior to the establishment of the plateau which is characteristic of levodopa administration in the fasting state. In consequence the ratio of the second to the initial phase of emptying was significantly higher (P < 0.01) following benzhexol treatment. 5. Benzhexol reduces the initial phase of gastric emptying after a dose of levodopa so that there is a decrease in the initial peak and a greater proportion of the dose is absorbed subsequently following the second phase of gastric emptying which occurs approximately 1 h later. Theoretically, this altered concentration-time profile could be an advantage for some patients with Parkinson's disease.

Associations of maternal macronutrient intake during pregnancy with infant BMI peak characteristics and childhood BMI.

PubMed

Chen, Ling-Wei; Aris, Izzuddin M; Bernard, Jonathan Y; Tint, Mya-Thway; Colega, Marjorelee; Gluckman, Peter D; Tan, Kok Hian; Shek, Lynette Pei-Chi; Chong, Yap-Seng; Yap, Fabian; Godfrey, Keith M; van Dam, Rob M; Chong, Mary Foong-Fong; Lee, Yung Seng

2017-03-01

Background: Infant body mass index (BMI) peak characteristics and early childhood BMI are emerging markers of future obesity and cardiometabolic disease risk, but little is known about their maternal nutritional determinants. Objective: We investigated the associations of maternal macronutrient intake with infant BMI peak characteristics and childhood BMI in the Growing Up in Singapore Towards healthy Outcomes study. Design: With the use of infant BMI data from birth to age 18 mo, infant BMI peak characteristics [age (in months) and magnitude (BMI peak ; in kg/m 2 ) at peak and prepeak velocities] were derived from subject-specific BMI curves that were fitted with the use of mixed-effects model with a natural cubic spline function. Associations of maternal macronutrient intake (assessed by using a 24-h recall during late gestation) with infant BMI peak characteristics ( n = 910) and BMI z scores at ages 2, 3, and 4 y were examined with the use of multivariable linear regression. Results: Mean absolute maternal macronutrient intakes (percentages of energy) were 72 g protein (15.6%), 69 g fat (32.6%), and 238 g carbohydrate (51.8%). A 25-g (∼100-kcal) increase in maternal carbohydrate intake was associated with a 0.01/mo (95% CI: 0.0003, 0.01/mo) higher prepeak velocity and a 0.04 (95% CI: 0.01, 0.08) higher BMI peak These associations were mainly driven by sugar intake, whereby a 25-g increment of maternal sugar intake was associated with a 0.02/mo (95% CI: 0.01, 0.03/mo) higher infant prepeak velocity and a 0.07 (95% CI: 0.01, 0.13) higher BMI peak Higher maternal carbohydrate and sugar intakes were associated with a higher offspring BMI z score at ages 2-4 y. Maternal protein and fat intakes were not consistently associated with the studied outcomes. Conclusion: Higher maternal carbohydrate and sugar intakes are associated with unfavorable infancy BMI peak characteristics and higher early childhood BMI. This trial was registered at clinicaltrials.gov as NCT01174875. © 2017 American Society for Nutrition.

GPS TEC Fluctuations in the Low and High Latitudes During the 2015 St. Patrick`s Day Storm

NASA Astrophysics Data System (ADS)

Chung, Jong-Kyun; Hong, Junseok; Yoo, Sung-Moon; Kim, Jeong-Han; Jee, Geonhwa; Hegai, Valery V.

2017-12-01

As a part of collaborative efforts to understand ionospheric irregularities, the Korea ionospheric scintillation sites (KISS) network has been built based on global positioning system (GPS) receivers with sampling rates higher than 1 Hz. We produce the rate of TEC index (ROTI) to represent GPS TEC fluctuations related to ionospheric irregularities. In the KISS network, two ground-based GPS sites at Kiruna (marker: KIRN; geographic: 67.9° N, 21.4° E; geomagnetic: 65.2° N) and Chuuk (marker: CHUK; geographic: 7.5° N, 151.9° E; geomagnetic: 0.4° N) were selected to evaluate the ROTI value for ionospheric irregularities during the occurrence of the 2015 St. Patrick’s Day storm. The KIRN ROTI values in the aurora region appear to be generally much higher than the CHUK ROTI values in the EIA region. The CHUK ROTI values increased to 0.5 TECU/min around UT=13:00 (LT=23:00) on March 16 in the quiet geomagnetic condition. On March 17, 2015, CHUK ROTI values more than 1.0 TECU/min were measured between UT=9:00 and 12:00 (LT=19:00 and 22:00) during the first main phase of the St. Patrick’s Day storm. This may be due to ionospheric irregularities by increased pre-reversal enhancement (PRE) after sunset during the geomagnetic storm. Post-midnight, the CHUK ROTI showed two peaks of 0.5 TECU/min and 0.3 TECU/min near UT=15:00 (LT=01:00) and UT=18:00 (LT=04:00) at the second main phase. The KIRN site showed significant peaks of ROTI around geomagnetic latitude=63.3° N and MLT=15:40 on the same day. These can be explained by enhanced ionospheric irregularities in the auroral oval at the maximum of AE index

Circadian characteristics of urinary leukotriene E(4) in healthy subjects and nocturnal asthmatic patients.

PubMed

Kurokawa, K; Tanaka, H; Tanaka, S; Abe, S

2001-12-01

Circadian rhythmicity of cysteinyl leukotrienes (LTs) and thromboxane (TX)-A(2) in healthy subjects and nocturnal asthmatic patients remains a subject of controversy. The aim of this study was to investigate the contribution of these mediators to the pathogenesis of nocturnal asthma. We measured peak expiratory flow rate, urinary concentration of LTE(4), 11-dehydro-TXB(2), and creatinine eight times every 3 h in three groups: healthy control subjects (n = 5, group A), nocturnal asthmatic patients (n = 9, group B), and nonnocturnal asthmatic subjects (n = 9, group C). To evaluate the reproducibility of the measurement of urinary LTE(4), we measured urinary LTE(4) in group A for 3 separate days. The urinary LTE(4) concentrations from 3 to 6 AM were significantly (p < 0.05) higher than from 3 to 6 PM in both group A and group B, but not in group C. The mean levels of LTE(4) in group B and group C were significantly higher (p < 0.05) than those in group A. In group B, another small peak was observed from 6 to 9 PM. No significant day-to-day variation was observed in group A. Urinary 11-dehydro-TXB(2) values from 3 to 6 AM were significantly (p < 0.001) higher than those levels from 3 to 6 PM in all groups, and the mean levels in group B and group C were significantly higher than those in group A (p < 0.05). Circadian rhythmicity of urinary LTE(4) with a morning peak was found in healthy control subjects and nocturnal asthmatic subjects, but not in nonnocturnal asthmatic patients. It was suggested that cysteinyl LTs rather than TXA(2) might contribute to the nocturnal worsening of asthma.

Peak Pc Prediction in Conjunction Analysis: Conjunction Assessment Risk Analysis. Pc Behavior Prediction Models

NASA Technical Reports Server (NTRS)

Vallejo, J.J.; Hejduk, M.D.; Stamey, J. D.

2015-01-01

Satellite conjunction risk typically evaluated through the probability of collision (Pc). Considers both conjunction geometry and uncertainties in both state estimates. Conjunction events initially discovered through Joint Space Operations Center (JSpOC) screenings, usually seven days before Time of Closest Approach (TCA). However, JSpOC continues to track objects and issue conjunction updates. Changes in state estimate and reduced propagation time cause Pc to change as event develops. These changes a combination of potentially predictable development and unpredictable changes in state estimate covariance. Operationally useful datum: the peak Pc. If it can reasonably be inferred that the peak Pc value has passed, then risk assessment can be conducted against this peak value. If this value is below remediation level, then event intensity can be relaxed. Can the peak Pc location be reasonably predicted?

Effect of menstrual cycle phase on the ventilatory response to rising body temperature during exercise.

PubMed

Hayashi, Keiji; Kawashima, Takayo; Suzuki, Yuichi

2012-07-01

To examine the effect of menstrual cycle on the ventilatory sensitivity to rising body temperature, ten healthy women exercised for ~60 min on a cycle ergometer at 50% of peak oxygen uptake during the follicular and luteal phases of their cycle. Esophageal temperature, mean skin temperature, mean body temperature, minute ventilation, and tidal volume were all significantly higher at baseline and during exercise in the luteal phase than the follicular phase. On the other hand, end-tidal partial pressure of carbon dioxide was significantly lower during exercise in the luteal phase than the follicular phase. Plotting ventilatory parameters against esophageal temperature revealed there to be no significant menstrual cycle-related differences in the slopes or intercepts of the regression lines, although minute ventilation and tidal volume did significantly differ during exercise with mild hyperthermia. To evaluate the cutaneous vasodilatory response, relative laser-Doppler flowmetry values were plotted against mean body temperature, which revealed that the mean body temperature threshold for cutaneous vasodilation was significantly higher in the luteal phase than the follicular phase, but there were no significant differences in the sensitivity or peak values. These results suggest that the menstrual cycle phase influences the cutaneous vasodilatory response during exercise and the ventilatory response at rest and during exercise with mild hyperthermia, but it does not influence ventilatory responses during exercise with moderate hyperthermia.

Improved Diagnostic Accuracy in Characterization of Adnexal Masses by Detection of Choline Peak Using 1H MR Spectroscopy in Comparison to Internal Reference at 3 Tesla.

PubMed

Malek, Mahrooz; Pourashraf, Maryam; Gilani, Mitra Modares; Gity, Masoumeh

2015-01-01

The aim of this study was to assess the role of the presence of a choline peak in 3 Tesla 1H magnetic resonance spectroscopy (MRS) for differentiating benign from malignant adnexal masses. A total of 46 adnexal masses (23 malignant and 23 benign) underwent 1H MRS study prior to surgery to assess the presence of choline peak. A choline peak was detected in 16 malignant masses (69.5%) and was absent in the other 7 (30.5%). A choline peak was only detected in 6 (26%) of the benign adnexal masses. The presence of an MRS choline peak had a sensitivity of 69.5%, a specificity of 74%, a positive predictive value (PPV) of 72.7%, and a negative predictive value (NPV) of 71% for diagnosing malignant adnexal masses. A significant difference between the frequency of mean choline peaks in benign and malignant adnexal masses was observed (P value<0.01). A 1H MRS choline peak is seen in malignant adnexal masses more frequently than the benign masses, and may be helpful for diagnosing malignant adnexal masses.

Application of Single Voxel 1H Magnetic Resonance Spectroscopy in Hepatic Benign and Malignant Lesions.

PubMed

Yang, Zifeng; Sun, Shiqiang; Chen, Yuanli; Li, Rui

2016-12-19

BACKGROUND To quantify the metabolite changes in hepatic tumors by single-voxel 1H magnetic resonance spectroscopy (MRS) at 3.0 T and explore the application value of 1HMRS in the diagnosis of hepatic benign and malignant lesions. MATERIAL AND METHODS A total of 45 patients (55 lesions) diagnosed with hepatic lesions by ultrasound and/or computer topography (CT) from November 2006 to March 2007 were included in this study. All patients underwent 3D-dynamic enhanced scan with liver acquisition with acceleration volume acquisition (LAVA) sequence and single-voxel 1HMRS imaging with PRESS (point-resolved spectroscopy) sequence. The metabolite concentrations such as choline (Cho) and lipids (Lip) were measured. RESULTS There was significant difference regarding the occurrence rate of the obvious elevated Cho peaks between benign and malignant tumors (7/27 vs. 21/28, p=0.000). There was statistical significant differences regarding the Cho/Lip ratios in hepatic benign (0.0686±0.0283, 95% CI: 0.0134-0.1245) and malignant (0.1266 ±0.1124, 95% CI: 0.0937-0.2203) lesions (p<0.05). When compared with the pathological results, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were 85.7% (24/28), 92.6% (25/27), 92.3% (24/26), 86.2% (25/29), and 89.1% (49/55) respectively for the MRI assessment, and 92.6% (26/28), 88.9% (24/27), 89.7 (26/29), 92.3 (24/26), and 90.9% (50/55) respectively for 1HMRS combined with MRI assessment. CONCLUSIONS Single Cho peaks or Lip peaks cannot be used for the diagnosis of hepatic benign and malignant lesions. Combined use of 1HMRS and MRI can greatly improve the application value of MRI assessment in the diagnosis of hepatic benign and malignant lesions with a higher sensitivity, negative predictive value, and overall accuracy.

Using semi-permeable membrane devices and stable nitrogen isotopes to detect anthropogenic influences on the Truckee River, USA

USGS Publications Warehouse

Saito, L.; Rosen, Michael R.; Chandra, S.; Fritsen, C.H.; Arufe, J.A.; Redd, C.

2008-01-01

Stable nitrogen isotopes (??15N) and semipermeable membrane devices (SPMDs) were used together to provide evidence of potential anthropogenic connections to aquatic organisms in the Truckee River, which flows through the Reno/Sparks metropolitan area in Nevada. Crayfish, snail, and periphyton ??15N values, and SPMD toxicity data collected during high and low flow periods at seven primary sites on the river were used with water quality and flow data for the assessment. All biota showed an increase of ??15N on both dates at sites downstream of inflows of a water-quality impaired tributary and urban drain relative to upstream. In addition, most of the lowest ??15N values on each date occurred at the most downstream site on the river. SPMDs sample lipophilic organic contaminants and can be used to assess organic contaminant toxicity to aquatic organisms because they use a membrane that mimics organic contaminant uptake by fish. In this study, results from a fluoroscan test [pyrene index (PI)] of SPMD extracts that responds to higher molecular weight polycyclic aromatic hydrocarbons (PAHs) showed patterns similar to stable isotope data, although observed peaks in PI values occurred in the urban area upstream of where peak ??15N values occurred. The CYP1A biomarker test, which responds to PAHs, certain polychlorinated biphenyls (PCBs), and organochlorines, showed peak toxic equivalents (TEQ) values farther downstream of the urban area. Thus, it is likely that PAHs were contributing to toxicity in the urban area, whereas other nonurban sources of organic carbon may have been present farther downstream. The combined use of stable isotope measurements and SPMDs provided a means of simultaneously examining whether aquatic biota are incorporating constituents from potential food sources (via stable isotopes) or exposure through water (via SPMDs). ?? Mary Ann Liebert, Inc. 2008.

Annual Peak-Flow Frequency Characteristics and (or) Peak Dam-Pool-Elevation Frequency Characteristics of Dry Dams and Selected Streamflow-Gaging Stations in the Great Miami River Basin, Ohio

USGS Publications Warehouse

Koltun, G.F.

2009-01-01

This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin further downstream from one or more of the dams. In addition, this report describes frequency characteristics of annual peak elevations of the dry-dam pools. In most cases, log-Pearson Type III distributions were fit to postregulation annual peak-flow values through 2007 (the most recent year of published peak-flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922-2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. For one streamflow-gaging station (03272100) with a short period of record, frequency characteristics were estimated by means of a process involving interpolation of peak-flow yields determined for an upstream and downstream gage. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

ZT Optimization: An Application Focus

PubMed Central

Tuley, Richard; Simpson, Kevin

2017-01-01

Significant research has been performed on the challenge of improving thermoelectric materials, with maximum peak figure of merit, ZT, the most common target. We use an approximate thermoelectric material model, matched to real materials, to demonstrate that when an application is known, average ZT is a significantly better optimization target. We quantify this difference with some examples, with one scenario showing that changing the doping to increase peak ZT by 19% can lead to a performance drop of 16%. The importance of average ZT means that the temperature at which the ZT peak occurs should be given similar weight to the value of the peak. An ideal material for an application operates across the maximum peak ZT, otherwise maximum performance occurs when the peak value is reduced in order to improve the peak position. PMID:28772668

Comparison of dental implant stabilities by impact response and resonance frequencies using artificial bone.

PubMed

Kim, Dae-Seung; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe; Kim, Tae-Il; Yi, Won-Jin

2014-06-01

We compared implant stability as determined by the peak frequency from the impact response with the implant stability quotient (ISQ) by resonance frequency analysis (RFA) in various artificial bone conditions. The clinical bone conditions were simulated using an artificial bone material with different cortical thicknesses and trabecular densities. The artificial bone material was solid, rigid polyurethane. The polyurethane foam of 0.8g/cm(3) density was used for the cortical bone layer, and that of 0.08, 0.16, 0.24, 0.32, and 0.48g/cm(3) densities for the trabecular bone layer. The cortical bone material of 4 different thicknesses (1.4, 1.6, 1.8, and 2.0mm) was attached to the trabecular bone with varying density. Two types of dental implants (10 and 13mm lengths of 4.0mm diameter) were placed into the artificial bone blocks. An inductive sensor was used to measure the vibration caused by tapping the adapter-implant assembly. The peak frequency of the power spectrum of the impact response was used as the criterion for implant stability. The ISQ value was also measured for the same conditions. The stability, as measured by peak frequency (SPF) and ISQ value, increased as the trabecular density and the cortical density increased in linear regression analysis. The SPF and ISQ values were highly correlated with each other when the trabecular bone density and cortical bone thickness changed (Pearson correlation=0.90, p<0.01). The linear regression of the SPF with the cortical bone thickness showed higher goodness of fit (R(2) measure) than the ISQ value with the cortical bone thickness. The SPF could differentiate implantation conditions as many as the ISQ value when the trabecular bone density and the cortical density changed. However, the ISQ value was not consistent with the general stability tendency in some conditions. The SPF showed better consistency and differentiability with implant stability than the ISQ value by resonance frequency analysis in the various implantation conditions. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Influence of Nanoinclusions on Thermoelectric Properties of n-Type Bi2Te3 Nanocomposites

NASA Astrophysics Data System (ADS)

Fan, Shufen; Zhao, Junnan; Yan, Qingyu; Ma, Jan; Hng, Huey Hoon

2011-05-01

n-Type Bi2Te3 nanocomposites with enhanced figure of merit, ZT, were fabricated by a simple, high-throughput method of mixing nanostructured Bi2Te3 particles obtained through melt spinning with micron-sized particles. Moderately high power factors were retained, while the thermal conductivity of the nanocomposites was found to decrease with increasing weight percent of nanoinclusions. The peak ZT values for all the nanocomposites were above 1.1, and the maximum shifted to higher temperature with increasing amount of nanoinclusions. A maximum ZT of 1.18 at 42°C was obtained for the 10 wt.% nanocomposite, which is a 43% increase over the bulk sample at the same temperature. This is the highest ZT reported for n-type Bi2Te3 binary material, and higher ZT values are expected if state-of-the-art Bi2Te3- x Se x materials are used.

Reference values for blood pressure response to cycle ergometry in the first two decades of life: comparison with patients with a repaired coarctation of the aorta.

PubMed

Kaafarani, Mirna; Schroer, Christian; Takken, Tim

2017-12-01

Hemodynamic responses to exercise are used as markers of diagnosis for cardiac diseases, systolic blood pressure (SBP) especially. However, the reference values for SBP in children at peak exertion level are outdated. This study aimed to establish current reference values for SBP, rate pressure product (RPP), and circulatory power (CircP). Data from children who previously underwent cardiopulmonary exercise testing were categorized as healthy (N = 184; age 12.6 ± 2.9 years), and CoA patients (N = 25; age 13.0 ± 3.2 years). With the Lambda-Mu-Sigma (LMS) method, percentile curves were made for SBP, CircP, and RPP in function of peak work rate (Wpeak). Data of CoA patients were used to validate the reference values. Wpeak was the best predictor of peak SBP during exercise. The prediction equations for SBP, CircP and RPP were: (0.2853 x Wpeak) + 111.46; (10.56 x Wpeak) + 2550.2 and (61.879 x Wpeak) + 19.887, respectively. CoA patients showed significantly increased values for peak SBP (Z-score 1.063 ± 1.347). This study provides reference values for SBP, RPP, and CircP at peak exercise. These values can be used for objective evaluation of participants 6-18 years of age in a Dutch population.

The Potential Effect of Sea Level Rise on Coastal Property Values

NASA Astrophysics Data System (ADS)

O'Donnell, J.

2015-12-01

It is well established that one consequence of increasing global sea level is that the frequency of flooding at low-lying coastal sites will increase. We review recent evidence that the effects coastal geometry will create substantial spatial variations in the changes in flooding frequency with scales of order 100km. Using a simple model of the evolution of coastal property values we demonstrate that a consequence of sea level rise is that the appreciation of coastal properties will peak, and then decline relative to higher properties. The time when the value reach a maximum is shown to depend upon the demand for the coastal property, and the local rate of change of flooding frequency due to sea level rise. The simple model is then extended to include, in an elementary manner, the effects on the value of adjacent but higher properties. We show that the effect of increased flooding frequency of the lower properties leads to an accelerated appreciation of the value of upland properties and an accelerated decline in the value of the coastal properties. We then provide some example calculations for selected sites. We conclude with a discussion of comparisons of the prediction of the analyses to recent data, and then comments on the impact of sea level rise on tax base of coastal communities.

Temporal trend studies on tetra- and pentabrominated diphenyl ethers and hexabromocyclododecane in guillemot egg from the Baltic Sea.

PubMed

Sellström, Ulla; Bignert, Anders; Kierkegaard, Amelie; Häggberg, Lisbeth; de Wit, Cynthia A; Olsson, Mats; Jansson, Bo

2003-12-15

Guillemot eggs from the Baltic Sea, sampled between 1969 and 2001, were analyzed for tetra- and pentabromodiphenyl ethers (2,2',4,4'-tetraBDE (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), and 2,2',4,4',6-pentaBDE (BDE-100)), and hexabromocyclododecane (HBCD). This temporal trend study indicates that the concentrations of the polybrominated diphenyl ether compounds increased from the 1970s to the 1980s, peaking around the mid- to the late-1980s. These peaks are then followed by a rapid decrease in concentrations during the rest of the study period, with the concentrations of the major BDE congener below 100 ng/g lipid weight at the end of the period. This corresponds to less than 10% of its peak values. The concentrations of HBCD show a different pattern over time. After a peak in the middle of the 1970s followed by a decrease, the concentrations increased during the latter part of the 1980s. During the recent 10-yr period no significant change has occurred, and the annual mean concentrations are more or less stable at a higher level as compared to the beginning of the study period.

Investigating the impact of land cover change on peak river flow in UK upland peat catchments, based on modelled scenarios

NASA Astrophysics Data System (ADS)

Gao, Jihui; Holden, Joseph; Kirkby, Mike

2014-05-01

Changes to land cover can influence the velocity of overland flow. In headwater peatlands, saturation means that overland flow is a dominant source of runoff, particularly during heavy rainfall events. Human modifications in headwater peatlands may include removal of vegetation (e.g. by erosion processes, fire, pollution, overgrazing) or pro-active revegetation of peat with sedges such as Eriophorum or mosses such as Sphagnum. How these modifications affect the river flow, and in particular the flood peak, in headwater peatlands is a key problem for land management. In particular, the impact of the spatial distribution of land cover change (e.g. different locations and sizes of land cover change area) on river flow is not clear. In this presentation a new fully distributed version of TOPMODEL, which represents the effects of distributed land cover change on river discharge, was employed to investigate land cover change impacts in three UK upland peat catchments (Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England). Land cover scenarios with three typical land covers (i.e. Eriophorum, Sphagnum and bare peat) having different surface roughness in upland peatlands were designed for these catchments to investigate land cover impacts on river flow through simulation runs of the distributed model. As a result of hypothesis testing three land cover principles emerged from the work as follows: Principle (1): Well vegetated buffer strips are important for reducing flow peaks. A wider bare peat strip nearer to the river channel gives a higher flow peak and reduces the delay to peak; conversely, a wider buffer strip with higher density vegetation (e.g. Sphagnum) leads to a lower peak and postpones the peak. In both cases, a narrower buffer strip surrounding upstream and downstream channels has a greater effect than a thicker buffer strip just based around the downstream river network. Principle (2): When the area of change is equal, the size of land cover change patches has no effect on river flow for patch sizes up to 40000m2. Principle (3): Bare peat on gentle slopes gives a faster flow response and higher peak value at the catchment outlet, while high density vegetation or re-vegetation on a gentle slope area has larger positive impact on peak river flow delay when compared with the same practices on steeper slopes. These simple principles should be useful to planners who wish to determine resource efficiency and optimisation for peatland protection and restoration works in headwater systems. If practitioners require further detail on impacts of specific spatial changes to land cover in a catchment then this modelling approach can be applied to new catchments of concern.

Head-to-head comparison of peak supine bicycle exercise echocardiography and treadmill exercise echocardiography at peak and at post-exercise for the detection of coronary artery disease.

PubMed

Peteiro, Jesús; Bouzas-Mosquera, Alberto; Estevez, Rodrigo; Pazos, Pablo; Piñeiro, Miriam; Castro-Beiras, Alfonso

2012-03-01

Supine bicycle exercise (SBE) echocardiography and treadmill exercise (TME) echocardiography have been used for evaluation of coronary artery disease (CAD). Although peak imaging acquisition has been considered unfeasible with TME, higher sensitivity for the detection of CAD has been recently found with this method compared with post-TME echocardiography. However, peak TME echocardiography has not been previously compared with the more standardized peak SBE echocardiography. The aim of this study was to compare peak TME echocardiography, peak SBE echocardiography, and post-TME echocardiography for the detection of CAD. A series of 116 patients (mean age, 61 ± 10 years) referred for evaluation of CAD underwent SBE (starting at 25 W, with 25-W increments every 2-3 min) and TME with peak and postexercise imaging acquisition, in a random sequence. Digitized images at baseline, at peak TME, after TME, and at peak SBE were interpreted in a random and blinded fashion. All patients underwent coronary angiography. Maximal heart rate was higher during TME, whereas systolic blood pressure was higher during SBE, resulting in similar rate-pressure products. On quantitative angiography, 75 patients had coronary stenosis (≥50%). In these patients, wall motion score indexes at maximal exercise were higher at peak TME (median, 1.45; interquartile range [IQR], 1.13-1.75) than at peak SBE (median, 1.25; IQR, 1.0-1.56) or after TME (median, 1.13; IQR, 1.0-1.38) (P = .002 between peak TME and peak SBE imaging, P < .001 between post-TME imaging and the other modalities). The extent of myocardial ischemia (number of ischemic segments) was also higher during peak TME (median, 5; IQR, 2-12) compared with peak SBE (median, 3; IQR, 0-8) or after TME (median, 2; IQR, 0-4) (P < .001 between peak TME and peak SBE imaging, P < .001 between post-TME imaging and the other modalities). ST-segment changes in patients with CAD and normal baseline ST segments were higher during TME (median, 1 mm [IQR, 0-1.9 mm] vs 0 mm [IQR, 0-1.5 mm]; P = .006). The sensitivity of peak TME, peak SBE, and post-TME echocardiography for CAD was 84%, 75%, and 60% (P = .001 between post-TME and peak TME echocardiography, P = .055 between post-TME and peak SBE echocardiography), with specificity of 63%, 80%, and 78%, respectively (P = NS) and accuracy of 77%, 77%, and 66%, respectively (P = NS). Peak TME echocardiography diagnosed multivessel disease in 27 of the 40 patients with stenoses in more than one coronary artery, in contrast to 17 patients with peak SBE imaging and 12 with post-TME imaging (P < .05 between peak TME imaging and the other modalities). Image quality was similar with the three techniques. The duration of the test was longer with SBE echocardiography (9.5 ± 3.8 vs 7.6 ± 2.5 min, P < .001). During TME and SBE, patients achieve similar double products. Ischemia is more extensive and frequent with peak TME, which makes peak TME a more valuable exercise echocardiographic modality to increase sensitivity. However, peak SBE should be preferred to TME if the latter is performed with postexercise imaging acquisition. Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

A method for estimating peak and time of peak streamflow from excess rainfall for 10- to 640-acre watersheds in the Houston, Texas, metropolitan area

USGS Publications Warehouse

Asquith, William H.; Cleveland, Theodore G.; Roussel, Meghan C.

2011-01-01

Estimates of peak and time of peak streamflow for small watersheds (less than about 640 acres) in a suburban to urban, low-slope setting are needed for drainage design that is cost-effective and risk-mitigated. During 2007-10, the U.S. Geological Survey (USGS), in cooperation with the Harris County Flood Control District and the Texas Department of Transportation, developed a method to estimate peak and time of peak streamflow from excess rainfall for 10- to 640-acre watersheds in the Houston, Texas, metropolitan area. To develop the method, 24 watersheds in the study area with drainage areas less than about 3.5 square miles (2,240 acres) and with concomitant rainfall and runoff data were selected. The method is based on conjunctive analysis of rainfall and runoff data in the context of the unit hydrograph method and the rational method. For the unit hydrograph analysis, a gamma distribution model of unit hydrograph shape (a gamma unit hydrograph) was chosen and parameters estimated through matching of modeled peak and time of peak streamflow to observed values on a storm-by-storm basis. Watershed mean or watershed-specific values of peak and time to peak ("time to peak" is a parameter of the gamma unit hydrograph and is distinct from "time of peak") of the gamma unit hydrograph were computed. Two regression equations to estimate peak and time to peak of the gamma unit hydrograph that are based on watershed characteristics of drainage area and basin-development factor (BDF) were developed. For the rational method analysis, a lag time (time-R), volumetric runoff coefficient, and runoff coefficient were computed on a storm-by-storm basis. Watershed-specific values of these three metrics were computed. A regression equation to estimate time-R based on drainage area and BDF was developed. Overall arithmetic means of volumetric runoff coefficient (0.41 dimensionless) and runoff coefficient (0.25 dimensionless) for the 24 watersheds were used to express the rational method in terms of excess rainfall (the excess rational method). Both the unit hydrograph method and excess rational method are shown to provide similar estimates of peak and time of peak streamflow. The results from the two methods can be combined by using arithmetic means. A nomograph is provided that shows the respective relations between the arithmetic-mean peak and time of peak streamflow to drainage areas ranging from 10 to 640 acres. The nomograph also shows the respective relations for selected BDF ranging from undeveloped to fully developed conditions. The nomograph represents the peak streamflow for 1 inch of excess rainfall based on drainage area and BDF; the peak streamflow for design storms from the nomograph can be multiplied by the excess rainfall to estimate peak streamflow. Time of peak streamflow is readily obtained from the nomograph. Therefore, given excess rainfall values derived from watershed-loss models, which are beyond the scope of this report, the nomograph represents a method for estimating peak and time of peak streamflow for applicable watersheds in the Houston metropolitan area. Lastly, analysis of the relative influence of BDF on peak streamflow is provided, and the results indicate a 0:04log10 cubic feet per second change of peak streamflow per positive unit of change in BDF. This relative change can be used to adjust peak streamflow from the method or other hydrologic methods for a given BDF to other BDF values; example computations are provided.

Increased longitudinal contractility and diastolic function at rest in well-trained amateur Marathon runners: a speckle tracking echocardiography study

PubMed Central

2014-01-01

Background Regular physical activity reduces cardiovascular risk. There is concern that Marathon running might acutely damage the heart. It is unknown to what extent intensive physical endurance activity influences the cardiac mechanics at resting condition. Methods Eighty-four amateur marathon runners (43 women and 41 men) from Berlin-Brandenburg area who had completed at least one marathon previously underwent clinical examination and echocardiography at least 10 days before the Berlin Marathon at rest. Standard transthoracic echocardiography and 2D strain and strain rate analysis were performed. The 2D Strain and strain rate values were compared to previous published data of healthy untrained individuals. Results The average global longitudinal peak systolic strain of the left ventricle was -23 +/- 2% with peak systolic strain rate -1.39 +/- 0.21/s, early diastolic strain rate 2.0 +/- 0.40/s and late diastolic strain rate 1.21 +/- 0.31/s. These values are significantly higher compared to the previous published values of normal age-adjusted individuals. In addition, no age-related decline of longitudinal contractility in well-trained athletes was observed. Conclusions There is increased overall longitudinal myocardial contractility at rest in experienced endurance athletes compared to the published normal values in the literature indicating a preserved and even supra-normal contractility in the athletes. There is no age dependent decline of the longitudinal 2D Strain values. This underlines the beneficial effects of regular physical exercise even in advanced age. PMID:24571726

Bomb-14C Peak in the North Pacific Recorded in Long-Lived Bivalve Shells (Mercenaria stimpsoni)

NASA Astrophysics Data System (ADS)

Kubota, Kaoru; Shirai, Kotaro; Murakami-Sugihara, Naoko; Seike, Koji; Minami, Masayo; Nakamura, Toshio; Tanabe, Kazushige

2018-04-01

The excess radiocarbon produced by nuclear bomb testing in the atmosphere in the 1950s-1960s (bomb-14C) is used as a tracer in the surface ocean, extending our understanding of geophysics and biogeochemical cycles. However, there is no bomb-14C record for the high-latitude western North Pacific Ocean because of the paucity of long-lived marine calcifying organisms equivalent to reef-building corals. The shells of Stimpson's hard clam, Mercenaria stimpsoni, potentially provide such a record because the clam's lifespan is very long (>100 years). We analyzed 14C in six live-caught M. stimpsoni shells from the western North Pacific (39.4°N, 142°E) and report, for the first time, the bomb-14C record with robust calendar ages based on annual growth increments. The value was constant in 1934-1952 (Δ14C = -66‰), with a sudden increase in 1959, a peak in 1974 (107‰), which was 60‰ lower than that of the Kuroshio Current, a gradual decline after 1974, and a current value of 16-18‰, which is ˜10‰ higher than the atmospheric value. The bomb-14C values are between the Kuroshio Current (the northwestern subtropical gyre) and Oyashio Current (the Western Subarctic Gyre) values, suggesting that the Tsugaru Current, downstream from the Kuroshio Current, mixes with the Oyashio Current after passing through Tsugaru Strait.

Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia

PubMed Central

Ismail, Catheeja; Zabal, Johannah; Hernandez, Haniel J.; Woletz, Paula; Manning, Heather; Teixeira, Carla; DiPietro, Loretta; Blackman, Marc R.; Harris-Love, Michael O.

2015-01-01

Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM) to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance. Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ± 20.9 years; BMI: 23.8, interquartile range: 8.5). Dual energy X-ray absorptiometry (DXA) and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2), and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups. Results: The selected LBM predictor variables were body mass index (BMI), ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = 0.61, p < 0.001), the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = 0.85, p < 0.001). Scaled peak force was associated with age and echogenicity (adj. R2 = 0.53, p < 0.001), but not LBM. The Low LBM subgroup of women (n = 10) had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < 0.05). Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more strongly associated with strength than muscle mass within the study sample. PMID:26578974

Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia.

PubMed

Ismail, Catheeja; Zabal, Johannah; Hernandez, Haniel J; Woletz, Paula; Manning, Heather; Teixeira, Carla; DiPietro, Loretta; Blackman, Marc R; Harris-Love, Michael O

2015-01-01

Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM) to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance. Twenty community-dwelling female subjects participated in the study (age = 43.4 ± 20.9 years; BMI: 23.8, interquartile range: 8.5). Dual energy X-ray absorptiometry (DXA) and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht(2)), and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m(2) determined participant assignment into the Normal LBM and Low LBM subgroups. The selected LBM predictor variables were body mass index (BMI), ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht(2) (adj. R (2) = 0.61, p < 0.001), the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R (2) = 0.85, p < 0.001). Scaled peak force was associated with age and echogenicity (adj. R (2) = 0.53, p < 0.001), but not LBM. The Low LBM subgroup of women (n = 10) had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < 0.05). Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht(2) in women. In addition, ultrasound proxy measures of muscle quality are more strongly associated with strength than muscle mass within the study sample.

Effects of Sex and Fatigue on Biomechanical Measures During the Drop-Jump Task in Children

PubMed Central

Briem, Kristín; Jónsdóttir, Kolbrún Vala; Árnason, Árni; Sveinsson, Þórarinn

2017-01-01

Background: Female athletes have a higher rate of anterior cruciate ligament (ACL) injury than males from adolescence and into maturity, which is suggested to result from sex-specific changes in dynamic movement patterns with maturation. Few studies have studied movement strategies and response to fatigue in children. Purpose: To evaluate the effect of fatigue on biomechanical variables associated with increased risk for ACL injury during a drop-jump (DJ) performance in children. Study Design: Controlled laboratory study. Methods: A total of 116 children (mean age, 10.4 years) were recruited from local sports clubs and performed 5 repetitions of a DJ task before and after a fatigue protocol. Kinematic and kinetic data from initial contact (IC) to the first peak vertical ground reaction force (vGRF) were analyzed for both limbs, including limb and fatigue as within-subject factors for analyses between boys and girls. Pearson correlation coefficients were calculated to identify associations between variables of interest. Results: Girls demonstrated greater peak vGRF values than boys (by 8.1%; P < .05), there were greater peak vGRF values for the right limb than the left (by 6.2%; P < .001), and fatigue led to slightly greater values (P < .05). Although weak, the correlation between peak vGRF values and knee flexion excursion was stronger for girls (r = –0.20) than boys (r = –0.08) (P < .006). Fatigue resulted in greater knee flexion angles at IC and less excursion during landing, more so for girls (by 6.1° vs 1.4°; interaction, P < .001), although the knee flexion moment was generally lowered by fatigue (P < .001). Limb asymmetry in knee flexion moments was more pronounced for boys than for girls (interaction, P < .05), contrary to that seen in frontal plane knee moments, where asymmetry was much greater in girls than boys (interaction, P < .001). Conclusion: Even as young athletes, girls and boys seem to adopt dissimilar movement strategies and are differently affected by fatigue. Clinical Relevance: Injury prevention programs should be considered at an earlier age in an effort to lower the risk of ACL injury in athletes. PMID:28203593

Observation of low magnetic field density peaks in helicon plasma

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

Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.

2013-04-15

Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peakmore » value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.« less

Thermoluminescence solid-state nanodosimetry—the peak 5A/5 dosemeter

PubMed Central

Fuks, E.; Horowitz, Y. S.; Horowitz, A.; Oster, L.; Marino, S.; Rainer, M.; Rosenfeld, A.; Datz, H.

2011-01-01

The shape of composite peak 5 in the glow curve of LiF:Mg,Ti (TLD-100) following 90Sr/90Y beta irradiation, previously demonstrated to be dependent on the cooling rate used in the 400°C pre-irradiation anneal, is shown to be dependent on ionisation density in both naturally cooled and slow-cooled samples. Following heavy-charged particle high-ionisation density (HID) irradiation, the temperature of composite peak 5 decreases by ∼5°C and the peak becomes broader. This behaviour is attributed to an increase in the relative intensity of peak 5a (a low-temperature satellite of peak 5). The relative intensity of peak 5a is estimated using a computerised glow curve deconvolution code based on first-order kinetics. The analysis uses kinetic parameters for peaks 4 and 5 determined from ancillary measurements resulting in nearly ‘single-glow peak’ curves for both the peaks. In the slow-cooled samples, owing to the increased relative intensity of peak 5a compared with the naturally cooled samples, the precision of the measurement of the 5a/5 intensity ratio is found to be ∼15 % (1 SD) compared with ∼25 % for the naturally cooled samples. The ratio of peak 5a/5 in the slow-cooled samples is found to increase systematically and gradually through a variety of radiation fields from a minimum value of 0.13±0.02 for 90Sr/90Y low-ionisation density irradiations to a maximum value of ∼0.8 for 20 MeV Cu and I ion HID irradiations. Irradiation by low-energy electrons of energy 0.1–1.5 keV results in values between 1.27 and 0.95, respectively. The increasing values of the ratio of peak 5a/5 with increasing ionisation density demonstrate the viability of the concept of the peak 5a/5 nanodosemeter and its potential in the measurement of average ionisation density in a ‘nanoscopic’ mass containing the trapping centre/luminescent centre spatially correlated molecule giving rise to composite peak 5. PMID:21149323

Verification of 1921 peak discharge at Skagit River near Concrete, Washington, using 2003 peak-discharge data

USGS Publications Warehouse

Mastin, M.C.; Kresch, D.L.

2005-01-01

The 1921 peak discharge at Skagit River near Concrete, Washington (U.S. Geological Survey streamflow-gaging station 12194000), was verified using peak-discharge data from the flood of October 21, 2003, the largest flood since 1921. This peak discharge is critical to determining other high discharges at the gaging station and to reliably estimating the 100-year flood, the primary design flood being used in a current flood study of the Skagit River basin. The four largest annual peak discharges of record (1897, 1909, 1917, and 1921) were used to determine the 100-year flood discharge at Skagit River near Concrete. The peak discharge on December 13, 1921, was determined by James E. Stewart of the U.S. Geological Survey using a slope-area measurement and a contracted-opening measurement. An extended stage-discharge rating curve based on the 1921 peak discharge was used to determine the peak discharges of the three other large floods. Any inaccuracy in the 1921 peak discharge also would affect the accuracies of the three other largest peak discharges. The peak discharge of the 1921 flood was recalculated using the cross sections and high-water marks surveyed after the 1921 flood in conjunction with a new estimate of the channel roughness coefficient (n value) based on an n-verification analysis of the peak discharge of the October 21, 2003, flood. The n value used by Stewart for his slope-area measurement of the 1921 flood was 0.033, and the corresponding calculated peak discharge was 240,000 cubic feet per second (ft3/s). Determination of a single definitive water-surface profile for use in the n-verification analysis was precluded because of considerable variation in elevations of surveyed high-water marks from the flood on October 21, 2003. Therefore, n values were determined for two separate water-surface profiles thought to bracket a plausible range of water-surface slopes defined by high-water marks. The n value determined using the flattest plausible slope was 0.024 and the corresponding recalculated discharge of the 1921 slope-area measurement was 266,000 ft3/s. The n value determined using the steepest plausible slope was 0.032 and the corresponding recalculated discharge of the 1921 slope-area measurement was 215,000 ft3/s. The two recalculated discharges were 10.8 percent greater than (flattest slope) and 10.4 percent less than (steepest slope) the 1921 peak discharge of 240,000 ft3/s. The 1921 peak discharge was not revised because the average of the two recalculated discharges (240,500 ft3/s) is only 0.2 percent greater than the 1921 peak discharge.

Reconstructing surface ocean circulation with 129I time series records from corals

USGS Publications Warehouse

Chang, Ching-Chih; Burr, George S.; Jull, A. J. Timothy; Russell, Joellen L.; Biddulph, Dana; White, Lara; Prouty, Nancy G.; Chen, Yue-Gau; Chuan-Chou Shen,; Zhou, Weijian; Lam, Doan Dinh

2016-01-01

The long-lived radionuclide 129I (half-life: 15.7 × 106 yr) is well-known as a useful environmental tracer. At present, the global 129I in surface water is about 1–2 orders of magnitude higher than pre-1960 levels. Since the 1990s, anthropogenic 129I produced from industrial nuclear fuels reprocessing plants has been the primary source of 129I in marine surface waters of the Atlantic and around the globe. Here we present four coral 129I time series records from: 1) Con Dao and 2) Xisha Islands, the South China Sea, 3) Rabaul, Papua New Guinea and 4) Guam. The Con Dao coral 129I record features a sudden increase in 129I in 1959. The Xisha coral shows similar peak values for 129I as the Con Dao coral, punctuated by distinct low values, likely due to the upwelling in the central South China Sea. The Rabaul coral features much more gradual 129I increases in the 1970s, similar to a published record from the Solomon Islands. The Guam coral 129I record contains the largest measured values for any site, with two large peaks, in 1955 and 1959. Nuclear weapons testing was the primary 129I source in the Western Pacific in the latter part of the 20th Century, notably from testing in the Marshall Islands. The Guam 1955 peak and Con Dao 1959 increases are likely from the 1954 Castle Bravo test, and the Operation Hardtack I test is the most likely source of the 1959 peak observed at Guam. Radiogenic iodine found in coral was carried primarily through surface ocean currents. The coral 129I time series data provide a broad picture of the surface distribution and depth penetration of 129I in the Pacific Ocean over the past 60 years.

Electroencephalography Spectral Power Density in First-Episode Mania: A Comparative Study with Subsequent Remission Period.

PubMed

Güven, Sertaç; Kesebir, Sermin; Demirer, R Murat; Bilici, Mustafa

2015-06-01

Our aim in this study was to investigate spectral power density (PSD) in first-episode mania and subsequent remission period and to evaluate their difference. Sixty-nine consecutive cases referring to our hospital within the previous 1 year, who were evaluated as bipolar disorder manic episode according to The Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) at the first episode and had the informed consent form signed by first degree relatives, were included in this study. Exclusion criteria included having previous depressive episode, using drugs which could influence electroencephalographic activity before electroencephalography (EEG), and having previous neurological disease, particularly epilepsy, head trauma, and/or loss of consciousness. EEG records were obtained using a digital device in 16 channels; 23 surface electrodes were placed according to the International 10-20 system. Spectral power density (dbμV/Hz) of EEG signal provided information on the power carried out by EEG waves in defined frequancy range per unit frequency in the present study. A peak power value detected on the right with FP2P4 and on the left with F7T3 electrodes were found to be higher in the manic episode than in the remission period (p=0.018 and 0.025). In the remission period, in cases with psychotic symptoms during the manic period, F4C4 peak power value was found to be lower than that in cases with no psychotic findings during the manic period (p=0.027). There was no relation was found between YMRS scores and peak power scores. Electrophysiological corollary of mood episode is present from the onset of the disease, and it differs between the manic and remission periods of bipolar disorder. In the remission period, peak power values of PSD distinguish cases with psychotic findings from cases without psychotic findings when they were manic.

Reconstructing surface ocean circulation with 129I time series records from corals.

PubMed

Chang, Ching-Chih; Burr, George S; Jull, A J Timothy; Russell, Joellen L; Biddulph, Dana; White, Lara; Prouty, Nancy G; Chen, Yue-Gau; Shen, Chuan-Chou; Zhou, Weijian; Lam, Doan Dinh

2016-12-01

The long-lived radionuclide 129 I (half-life: 15.7 × 10 6  yr) is well-known as a useful environmental tracer. At present, the global 129 I in surface water is about 1-2 orders of magnitude higher than pre-1960 levels. Since the 1990s, anthropogenic 129 I produced from industrial nuclear fuels reprocessing plants has been the primary source of 129 I in marine surface waters of the Atlantic and around the globe. Here we present four coral 129 I time series records from: 1) Con Dao and 2) Xisha Islands, the South China Sea, 3) Rabaul, Papua New Guinea and 4) Guam. The Con Dao coral 129 I record features a sudden increase in 129 I in 1959. The Xisha coral shows similar peak values for 129 I as the Con Dao coral, punctuated by distinct low values, likely due to the upwelling in the central South China Sea. The Rabaul coral features much more gradual 129 I increases in the 1970s, similar to a published record from the Solomon Islands. The Guam coral 129 I record contains the largest measured values for any site, with two large peaks, in 1955 and 1959. Nuclear weapons testing was the primary 129 I source in the Western Pacific in the latter part of the 20th Century, notably from testing in the Marshall Islands. The Guam 1955 peak and Con Dao 1959 increases are likely from the 1954 Castle Bravo test, and the Operation Hardtack I test is the most likely source of the 1959 peak observed at Guam. Radiogenic iodine found in coral was carried primarily through surface ocean currents. The coral 129 I time series data provide a broad picture of the surface distribution and depth penetration of 129 I in the Pacific Ocean over the past 60 years. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The combined exercise stress echocardiography and cardiopulmonary exercise test for identification of masked heart failure with preserved ejection fraction in patients with hypertension.

PubMed

Nedeljkovic, Ivana; Banovic, Marko; Stepanovic, Jelena; Giga, Vojislav; Djordjevic-Dikic, Ana; Trifunovic, Danijela; Nedeljkovic, Milan; Petrovic, Milan; Dobric, Milan; Dikic, Nenad; Zlatar, Milan; Beleslin, Branko

2016-01-01

Heart failure with preserved ejection fraction (HFpEF) is commonly associated with hypertension (HTN). However, resting echocardiography (ECHO) can underestimate the severity of disease. Exercise stress echocardiography (ESE) and the cardiopulmonary exercise testing (CPX) appeared to be useful tests in dynamic assessment of HFpEF. The value of combined exercise stress echocardiography cardiopulmonary testing (ESE-CPX) in the identification of masked HFpEF is still undetermined. The purpose of this study was to analyse the value of the combined ESE-CPX in the identification of masked HFpEF in patients with HTN, dyspnoea and normal resting left ventricular (LV) systolic and diastolic function. We studied 87 patients with HTN, exertional dyspnoea and normal resting LV function. They all underwent ESE-CPX testing (supine bicycle, ramp protocol, 15 W/min). ECHO measurements were performed at rest, and at peak load. Achievement of peak E/e' ratio>15 was a marker for masked HFpEF. Increase of E/e'>15 occurred in 8/87 patients (9.2%) during ESE-CPX. Those patients had the lower peak VO2 (p = 0.012), the lower VO2 at anaerobic threshold (p = 0.025), the lower workload (p = 0.026), the lower peak partial pressure end tidal carbon dioxide (PetCO2) (p < 0.0001), and the higher VE/VCO2 slope (p < 0.0001) which was an independent multivariate predictor of HFpEF (p = 0.021), with the cut-off value of 32.95 according to the receiver-operator characteristic (ROC) curve (sensitivity (Sn) 100%, specificity (Sp) 90%). The combined ESE-CPX test is feasible and reliable test that can unmask HFpEF and may become an important aid in the early diagnosis of HFpEF, excluding the other causes of exertional dyspnoea. © The European Society of Cardiology 2015.

PM 2.5 mass concentrations in comparison with aerosol optical depths over the Arabian Sea and Indian Ocean during winter monsoon

NASA Astrophysics Data System (ADS)

Ramachandran, S.

An analysis of PM 2.5 mass concentrations and 0.5 μm aerosol optical depths (AODs) during the Northeast winter monsoon seasons of 1996-2000 is performed and intercompared. AODs are found to show diurnal variations over Coastal India (CI) (west coast) while they are relatively smooth over the Arabian Sea (AS) (5-20°N) and tropical Indian Ocean (TIO) (5°N-20°S). PM 2.5, PM 10 and total mass concentrations show less variations in a day over these oceanic regions. Columnar AODs are found to increase with an increase in the marine boundary layer aerosol concentrations over CI and AS while an opposite trend is seen over TIO. The yearly-mean AODs and mass concentrations are found to increase over CI and AS, over TIO the mass concentrations increased while the AODs decreased during 1996-2000. It is found from the 7-days air back trajectory analyses that at different altitudes air masses can originate from different source regions leading to changes in chemical, physical and optical characteristics of the aerosol between the surface and column. The differences in the surface and columnar measurements could also occur due to changes in the meteorological conditions, wind patterns, in addition to changes in production and subsequently the transport of aerosols. Least-squares fits to the above intercomparison resulted in intercepts of 0.24 and 0.22 over CI and AS indicating that the background AODs over these oceanic regions are higher. An examination of the daily-mean wind speeds and PM 2.5 mass concentrations yielded an index of wind dependence of 0.04 for AS and 0.07 for TIO. The background PM 2.5 mass concentrations are also found to be high at 36 and 25 μg m -3 over AS and TIO, respectively, indicating a stronger influence from the continent. Frequency distribution figures show that 28% of the PM 2.5 values over CI lie in the 60-80 μg m -3 range. Over AS the dominant mode of distribution is 40-60 μg m -3 with a peak value of 42%. Over TIO PM 2.5 values are found to peak in the lower mass bin of 0-20 μg m -3 at 33%. A latitudinal gradient is seen in the peak bin value of PM 2.5 as the ship moves away from the coast. About half the days over CI and 20% over AS and TIO, PM 2.5 values are found unhealthy indicating the influence of anthropogenic pollution and long-range transport of pollutants from the surrounding continental locations across these oceanic regimes. AODs are found to peak in the 0.2-0.4 bin at 52% over CI and 47% over AS. Over AS 32% of the AODs are found to be <0.2. More than 90% of AODs over TIO are <0.2. The feature is different when compared to three maritime locations in the Pacific where 75% or more cases have AODs <0.1. α values are found to peak in the 1.5-2 range over CI at 55% while they peak in the lower range of 1-1.5 at 49% and 26% over AS and TIO, respectively. Over the Pacific and Atlantic Oceans in more than 90% of the cases α was ⩽1.5, indicating that the amount of smaller and larger particles are higher over the Indian Ocean when compared to the Pacific and Atlantic. The spread in PM 2.5 and AOD indicates that it is a challenging task to obtain a good relation without additional inputs on the vertical distribution of aerosols as varied kinds of aerosols from different source regions contribute at different heights over these oceanic regions.

Dependence of nonlinear optical properties of Ag2S@ZnS core-shells on Zinc precursor and capping agent

NASA Astrophysics Data System (ADS)

Dehghanipour, M.; Khanzadeh, M.; Karimipour, M.; Molaei, M.

2018-03-01

In this research, four different types of Ag2S@ZnS core-shells were synthesized and their nonlinear optical (NLO) properties were investigated using a Z-scan technique by a 532 nm laser diode. Here, Ag2S and ZnS nanoparticles were also synthesized and their NLO properties were compared with Ag2S@ZnS core-shells. It was observed that the NLO properties of Ag2S@ZnS quantum dots significantly increased by increasing the values of Zn(NO3)2 and thioglycolic acid (TGA). It was also observed that the NLO properties of Ag2S@ZnS core-shells for 0.1 g of Zn(NO3)2 and 7000 μl TGA is higher than sole Ag2S and ZnS nanoparticles. In open aperture Z-scan curve of ZnS sample, a saturable absorption peak was observed and this peak was seen also in type of Ag2S@ZnS nanoparticles which the value of Zn(NO3)2 much more.

Synthesis of Al-26 in explosive hydrogen burning

NASA Technical Reports Server (NTRS)

Arnould, M.; Norgaard, H.; Thielemann, F.-K.; Hillebrandt, W.

1980-01-01

The possibility of Al-26 synthesis during the explosive processing of hydrogen-rich material in the outer layers of a supernova or in nova envelopes is investigated. It is found that in the peak temperature range of 1-3 x 10 to the 8th deg K and for expansion time scales of the order of 1-1000 s, values of (Al-26)/(Al-27) as high as 0.1-1 can be obtained for values of 0.001-100,000 for the product of the peak density in g/cu cm and the proton mass fraction. Such a level of Al-26 production is considerably higher than that of recent carbon/neon burning nucleosynthesis models, and is sufficient to account for the magnesium anomalies detected in certain inclusions from the Leoville and Allende meteorites. Al abundances resulting from a hydrodynamical calculation performed on the grounds of a 25 solar mass presupernova model are also presented, and the influence of uncertainties in the input physics is discussed; in particular, the rates of the (Mg-25)(p,gamma)(Al-26) and (Al-26)(p,gamma)(Si-27) key reactions are studied.

TNT equivalency of M10 propellant

NASA Technical Reports Server (NTRS)

Mcintyre, F. L.; Price, P.

1978-01-01

Peak, side-on blast overpressure and scaled, positive impulse have been measured for M10 single-perforated propellant, web size 0.018 inches, using configurations that simulate the handling of bulk material during processing and shipment. Quantities of 11.34, 22.7, 45.4, and 65.8 kg were tested in orthorhombic shipping containers and fiberboard boxes. High explosive equivalency values for each test series were obtained as a function of scaled distance by comparison to known pressure, arrival time and impulse characteristics for hemispherical TNT surface bursts. The equivalencies were found to depend significantly on scaled distance, with higher values of 150-100 percent (pressure) and 350-125 percent (positive impulse) for the extremes within the range from 1.19 to 3.57 m/cube root of kg. Equivalencies as low as 60-140 percent (pressure) and 30-75 percent (positive impulse) were obtained in the range of 7.14 to 15.8 m/cube root of kg. Within experimental error, both peak pressure and positive impulse scaled as a function of charge weight for all quantities tested in the orthorhombic configuration.

Coherence and interlimb force control: Effects of visual gain.

PubMed

Kang, Nyeonju; Cauraugh, James H

2018-03-06

Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

Anesthetic biotransformation and renal function in obese patients during and after methoxyflurane or halothane anesthesia.

PubMed

Young, S R; Stoelting, R K; Peterson, C; Madura, J A

1975-04-01

Anesthetic biotransformation and renal function were studied in obese adult patients (148 plus or minus 8 kg; mean plus or minus SE) anesthetized for three hours with 60 per cent nitrous oxide plus either methoxyflurane or halothane for elective jejunoileal small-bowel-bypass operations. There was no evidence of persistent renal dysfunction in any patient postoperatively, but serum osmolality was elevated 72 hours after methoxyflurane anesthesia. Urine concentrating ability was not determined. Peak serum ionic fluoride concentration was 55.8 plus or minus 5.8 muM/1 two hours after discontinuation of methoxyflurane. Urinary ionic fluoride and oxalate excretions increased postoperatively. Compared with previously reported data from nonobese patients, serum ionic fluoride concentrations in obese patients increased more rapidly during methoxyflurane anesthesia and peaked higher and sooner after discontinuation of methoxyflurane. The peak serum ionic fluoride concentration was 10.4 plus or minus 1.5 muM/1 at the conclusion of halothane anesthesia, significantly more than the corresponding value in nonobese patients. Intraoperative liver biopsies from 23 of 27 patients showed moderate to severe fatty metamorphosis. Fatty liver infiltration may have increased hepatic anesthetic uptake and exposed more methoxyflurane or halothane to hepatic microsomal enzymes. The more rapid elevation and higher peak levels of serum ionic fluoride following methoxyflurane, and to a lesser extent following halothane, may reflect increased anesthetic biotransformation in obese compared with nonobese patients. To avoid excessive serum ionic fluoride elevations the authors recommended limiting low-dose methoxyflurane anesthesia delivered to obese patients with potential fatty liver infiltration to no more than three hours.

Impact of dynamically changing land cover on runoff process: the case of Iligan river basin

NASA Astrophysics Data System (ADS)

Salcedo, Stephanie Mae B.; Suson, Peter D.; Milano, Alan E.; Ignacio, Ma. Teresa T.

2016-10-01

Iligan river basin located in Northern Mindanao, Philippines covers 165.7 km2 of basin area. In December 2011, tropical storm Sendong (Washi) hit Iligan City, leaving a trail of wrecked infrastructures and about 490 persons reported dead. What transpired was a wake up call to mitigate future flood disasters. Fundamental to mitigation is understanding runoff behavior inside a basin considering that this is the main source of flooding. For this reason, the present study evaluated total runoff volume, peak discharge and lag time given land cover scenarios in four different years- 1973, 1989, 1998 and 2008. IFSAR and LIDAR DEM were integrated to generate the basin model in ArcGIS. HEC-HMS was used in simulating models for each scenario with Soil Conservation Service Curve Number (SCS CN) as the loss parameter method. Four simulation models of the runoff with varying CN values were established using RIDF as rainfall input with 5 year, 10 year, 25 year, 50 year and 100 year Rainfall Return Period (RRP). Total Runoff volume, peak discharge and lag time were progressively higher from 1973 to 2008 with 1989 land cover as exception where runoff parameters was its lowest. The total runoff volume, peak discharge and lag time is governed by vegetation type. When vegetation is characterized predominantly with woody perennials, runoff volume and peak time is lower. Conversely, when the presence of woody perennials is minimal, these parameters are higher. This study shows that an important way to mitigate flooding is to reduce surface runoff by maintaining vegetation predominantly composed of woody perennials.

Gender differences associated with rearfoot, midfoot, and forefoot kinematics during running.

PubMed

Takabayashi, Tomoya; Edama, Mutsuaki; Nakamura, Masatoshi; Nakamura, Emi; Inai, Takuma; Kubo, Masayoshi

2017-11-01

Females, as compared with males, have a higher proportion of injuries in the foot region. However, the reason for this gender difference regarding foot injuries remains unclear. This study aimed to investigate gender differences associated with rearfoot, midfoot, and forefoot kinematics during running. Twelve healthy males and 12 females ran on a treadmill. The running speed was set to speed which changes from walking to running. Three-dimensional kinematics of rearfoot, midfoot, and forefoot were collected and compared between males and females. Furthermore, spatiotemporal parameters (speed, cadence, and step length) were measured. In the rearfoot angle, females showed a significantly greater peak value of plantarflexion and range of motion in the sagittal plane as compared with males (effect size (ES) = 1.55 and ES = 1.12, respectively). In the midfoot angle, females showed a significantly greater peak value of dorsiflexion and range of motion in the sagittal plane as compared with males (ES = 1.49 and ES = 1.71, respectively). The forefoot peak angles and ranges of motion were not significantly different between the genders in all three planes. A previous study suggested that a gender-related difference in excessive motions of the lower extremities during running has been suggested as a contributing factor to running injuries. Therefore, the present investigation may provide insight into the reason for the high incidence of foot injuries in females.

Estimation of ground motion parameters

USGS Publications Warehouse

Boore, David M.; Joyner, W.B.; Oliver, A.A.; Page, R.A.

1978-01-01

Strong motion data from western North America for earthquakes of magnitude greater than 5 are examined to provide the basis for estimating peak acceleration, velocity, displacement, and duration as a function of distance for three magnitude classes. A subset of the data (from the San Fernando earthquake) is used to assess the effects of structural size and of geologic site conditions on peak motions recorded at the base of structures. Small but statistically significant differences are observed in peak values of horizontal acceleration, velocity and displacement recorded on soil at the base of small structures compared with values recorded at the base of large structures. The peak acceleration tends to b3e less and the peak velocity and displacement tend to be greater on the average at the base of large structures than at the base of small structures. In the distance range used in the regression analysis (15-100 km) the values of peak horizontal acceleration recorded at soil sites in the San Fernando earthquake are not significantly different from the values recorded at rock sites, but values of peak horizontal velocity and displacement are significantly greater at soil sites than at rock sites. Some consideration is given to the prediction of ground motions at close distances where there are insufficient recorded data points. As might be expected from the lack of data, published relations for predicting peak horizontal acceleration give widely divergent estimates at close distances (three well known relations predict accelerations between 0.33 g to slightly over 1 g at a distance of 5 km from a magnitude 6.5 earthquake). After considering the physics of the faulting process, the few available data close to faults, and the modifying effects of surface topography, at the present time it would be difficult to accept estimates less than about 0.8 g, 110 cm/s, and 40 cm, respectively, for the mean values of peak acceleration, velocity, and displacement at rock sites within 5 km of fault rupture in a magnitude 6.5 earthquake. These estimates can be expected to change as more data become available.

The composite structure of peak 5 in the glow curve of LiF:Mg,Ti (TLD-100): confirmation of peak 5a arising from a locally trapped electron-hole configuration.

PubMed

Horowitz, Y S; Oster, L; Satinger, D; Biderman, S; Einav, Y

2002-01-01

The hypothesis that glow peak 5a arises from localised e-h capture is confirmed by the following experimental observations: (i) The high conversion efficiency (CE) (CE5a-->4 = 3 +/- 0.5) of peak 5a to peak 4 (a hole-only trap) deduced from detailed Im-Tstop optical bleaching studies at 310 nm compared to the much lower CE of peak 5 (an electron-only trap) (CE5-->4 = 0.0026+/-0.012). (ii) The lack of an increase in the sensitivity of glow peak 5a following 2.6 MeV and 6.8 MeV He ion irradiation in 'sensitised' material compared to the factor two increase in the sensitivity of peak 5; (S/S0)5a = 0.86+/-0.12, compared to (S/S0)5 = 2.0+/-0.2. (iii) The late entry into saturation of the 2.6 MeV and 6.8 MeV He ion TL-fluence response curves for peak 5a compared to peak 5 in sensitised and normal material resulting in the following values for the track radial saturation parameter: (r50)5a = 100+/-20) Angstroms compared to (r50)5 = 380+/-30 Angstroms. (iv) The low value of 0.1 for the 'track-escape' parameter of peak 5a deduced from the Extended Track Interaction Model analysis of He ion TL fluence response compared to order of magnitude greater values for peaks 5 and 5b.

Transient Ocular Wavefront Data in Type 1 Diabetes Mellitus.

PubMed

Blendowske, Ralf; Kalb, Max

2016-07-01

We report transient ocular wavefront and blood glucose data for one patient with acute type 1 diabetes mellitus after the treatment with insulin has been initiated. The wavefront data for both eyes of a 34-year-old male patient were examined by a Hartmann-Shack wavefront sensor. Refraction data and higher-order aberrations were recorded during 130 days for eyes in natural conditions, without cycloplegia. At the beginning, we sampled data every 3 to 4 days and enlarged the intervals, when values settled. In total, we report 20 measurements and 1 baseline entry. Blood glucose levels were recorded at least six times a day during the complete period. For the equivalent sphere, we recorded a bilateral hyperopic shift of 5 D from -2.75 DS to +2.25 DS, followed by a reverse myopic shift of the same amount. The equivalent sphere peaked about 15 to 18 days after the treatment with insulin had begun. Cylinder values kept remarkably stable. Higher-order aberrations are dominated by the spherical aberration. The Zernike coefficient c12 for both eyes changed substantially from OD 0.036 μm and OS 0.062 μm to OD 0.24 μm and OS 0.22 μm (5 mm pupil diameter) following the time pattern of the equivalent sphere. About 60 days after they had reached their peak, all refraction values and higher-order aberrations stabilized at their baseline levels. The baseline was defined by records taken 4 years before the treatment with insulin was commenced. Wavefront aberrometry gives quantitative insights in the transient alteration and recovering of the eye's optics whilst the therapy of acute type 1 diabetes mellitus is being initiated. The data of this case support the assumption that variations in the crystalline lens, most probably the modification of its refractive gradient index, as a cause for the transient behavior. An explanation is still missing.

Changes in plasma levels of adrenaline, noradrenaline, glucose, lactate and CO2 in the green turtle, Chelonia mydas, during peak period of nesting.

PubMed

Alkindi, A Y A; Al-Habsi, A A; Mahmoud, I Y

2008-02-01

Plasma concentrations of stress hormones [adrenaline (ADR), noradrenaline (NR)], lactate, glucose and CO2 were monitored during peak nesting period (May-October) at different phases of nesting in the green turtle, Chelonia mydas. These include, emergence from sea, excavating body and nest chambers, oviposition, covering and camouflaging the nest and then returning to sea. Turtles that completed all phases of nesting including oviposition before returning to sea were considered "successful" turtles, while those that completed all phases but failed to lay their eggs were "unsuccessful". Blood samples were taken from the cervical sinus within 5min of capture to avoid stress due to handling. The turtles were usually sampled for blood between 20:00 and 1:00h of nesting time to ensure uniformity in the sampling. Plasma ADR and NR values were highly significant (P<0.001) in successful turtles over emergence, excavating and unsuccessful turtles. Plasma glucose levels remained stable throughout the nesting phases while lactate levels were significantly higher in successful turtles over the other phases (P<0.05) which signifies anaerobic metabolism during nesting. Plasma CO2 values were negatively correlated with ADR and NR (r=-0.258, P=0.03; r=-0.304, P=0.010), respectively. Hematocrit was significantly higher in successful phase (P<0.05) compared to other phases, and this may signify a higher degree of stress in successful turtles. Body temperature were significantly lower (P<0.005) in the excavating phase compared to the other three phases. Overall, body temperatures were lower than sand temperatures around the nest, which may indicate a behavioral thermoregulation used by the turtles during nesting. This information will be of value to the ongoing conservation program at Ras Al-Hadd Reserve in the Sultanate of Oman.

[Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air].

PubMed

Xu, Wei-Hua; Shen, Hua-Hao

2010-02-25

When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.

A simple multi-scale Gaussian smoothing-based strategy for automatic chromatographic peak extraction.

PubMed

Fu, Hai-Yan; Guo, Jun-Wei; Yu, Yong-Jie; Li, He-Dong; Cui, Hua-Peng; Liu, Ping-Ping; Wang, Bing; Wang, Sheng; Lu, Peng

2016-06-24

Peak detection is a critical step in chromatographic data analysis. In the present work, we developed a multi-scale Gaussian smoothing-based strategy for accurate peak extraction. The strategy consisted of three stages: background drift correction, peak detection, and peak filtration. Background drift correction was implemented using a moving window strategy. The new peak detection method is a variant of the system used by the well-known MassSpecWavelet, i.e., chromatographic peaks are found at local maximum values under various smoothing window scales. Therefore, peaks can be detected through the ridge lines of maximum values under these window scales, and signals that are monotonously increased/decreased around the peak position could be treated as part of the peak. Instrumental noise was estimated after peak elimination, and a peak filtration strategy was performed to remove peaks with signal-to-noise ratios smaller than 3. The performance of our method was evaluated using two complex datasets. These datasets include essential oil samples for quality control obtained from gas chromatography and tobacco plant samples for metabolic profiling analysis obtained from gas chromatography coupled with mass spectrometry. Results confirmed the reasonability of the developed method. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental depth dose curves of a 67.5 MeV proton beam for benchmarking and validation of Monte Carlo simulation

PubMed Central

Faddegon, Bruce A.; Shin, Jungwook; Castenada, Carlos M.; Ramos-Méndez, José; Daftari, Inder K.

2015-01-01

Purpose: To measure depth dose curves for a 67.5 ± 0.1 MeV proton beam for benchmarking and validation of Monte Carlo simulation. Methods: Depth dose curves were measured in 2 beam lines. Protons in the raw beam line traversed a Ta scattering foil, 0.1016 or 0.381 mm thick, a secondary emission monitor comprised of thin Al foils, and a thin Kapton exit window. The beam energy and peak width and the composition and density of material traversed by the beam were known with sufficient accuracy to permit benchmark quality measurements. Diodes for charged particle dosimetry from two different manufacturers were used to scan the depth dose curves with 0.003 mm depth reproducibility in a water tank placed 300 mm from the exit window. Depth in water was determined with an uncertainty of 0.15 mm, including the uncertainty in the water equivalent depth of the sensitive volume of the detector. Parallel-plate chambers were used to verify the accuracy of the shape of the Bragg peak and the peak-to-plateau ratio measured with the diodes. The uncertainty in the measured peak-to-plateau ratio was 4%. Depth dose curves were also measured with a diode for a Bragg curve and treatment beam spread out Bragg peak (SOBP) on the beam line used for eye treatment. The measurements were compared to Monte Carlo simulation done with geant4 using topas. Results: The 80% dose at the distal side of the Bragg peak for the thinner foil was at 37.47 ± 0.11 mm (average of measurement with diodes from two different manufacturers), compared to the simulated value of 37.20 mm. The 80% dose for the thicker foil was at 35.08 ± 0.15 mm, compared to the simulated value of 34.90 mm. The measured peak-to-plateau ratio was within one standard deviation experimental uncertainty of the simulated result for the thinnest foil and two standard deviations for the thickest foil. It was necessary to include the collimation in the simulation, which had a more pronounced effect on the peak-to-plateau ratio for the thicker foil. The treatment beam, being unfocussed, had a broader Bragg peak than the raw beam. A 1.3 ± 0.1 MeV FWHM peak width in the energy distribution was used in the simulation to match the Bragg peak width. An additional 1.3–2.24 mm of water in the water column was required over the nominal values to match the measured depth penetration. Conclusions: The proton Bragg curve measured for the 0.1016 mm thick Ta foil provided the most accurate benchmark, having a low contribution of proton scatter from upstream of the water tank. The accuracy was 0.15% in measured beam energy and 0.3% in measured depth penetration at the Bragg peak. The depth of the distal edge of the Bragg peak in the simulation fell short of measurement, suggesting that the mean ionization potential of water is 2–5 eV higher than the 78 eV used in the stopping power calculation for the simulation. The eye treatment beam line depth dose curves provide validation of Monte Carlo simulation of a Bragg curve and SOBP with 4%/2 mm accuracy. PMID:26133619

Effect of respiratory motion on internal radiation dosimetry

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

Xie, Tianwu; Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch; Geneva Neuroscience Center, Geneva University, Geneva CH-1205

Purpose: Estimation of the radiation dose to internal organs is essential for the assessment of radiation risks and benefits to patients undergoing diagnostic and therapeutic nuclear medicine procedures including PET. Respiratory motion induces notable internal organ displacement, which influences the absorbed dose for external exposure to radiation. However, to their knowledge, the effect of respiratory motion on internal radiation dosimetry has never been reported before. Methods: Thirteen computational models representing the adult male at different respiratory phases corresponding to the normal respiratory cycle were generated from the 4D dynamic XCAT phantom. Monte Carlo calculations were performed using the MCNP transportmore » code to estimate the specific absorbed fractions (SAFs) of monoenergetic photons/electrons, the S-values of common positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82, Y-86, and I-124), and the absorbed dose of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) in 28 target regions for both the static (average of dynamic frames) and dynamic phantoms. Results: The self-absorbed dose for most organs/tissues is only slightly influenced by respiratory motion. However, for the lung, the self-absorbed SAF is about 11.5% higher at the peak exhale phase than the peak inhale phase for photon energies above 50 keV. The cross-absorbed dose is obviously affected by respiratory motion for many combinations of source-target pairs. The cross-absorbed S-values for the heart contents irradiating the lung are about 7.5% higher in the peak exhale phase than the peak inhale phase for different positron-emitting radionuclides. For {sup 18}F-FDG, organ absorbed doses are less influenced by respiratory motion. Conclusions: Respiration-induced volume variations of the lungs and the repositioning of internal organs affect the self-absorbed dose of the lungs and cross-absorbed dose between organs in internal radiation dosimetry. The dynamic anatomical model provides more accurate internal radiation dosimetry estimates for the lungs and abdominal organs based on realistic modeling of respiratory motion. This work also contributes to a better understanding of model-induced uncertainties in internal radiation dosimetry.« less

Global Characterization of Biomass-Burning Patterns using Satellite Measurements of Fire Radiative Energy

NASA Technical Reports Server (NTRS)

Ichoku, Charles; Giglio, Louis; Wooster, Martin J.; Remer, Lorraine A.

2008-01-01

Remote sensing is the most practical means of measuring energy release from large open-air biomass burning. Satellite measurement of fire radiative energy (FRE) release rate or power (FRP) enables distinction between fires of different strengths. Based on a 1-km resolution fire data acquired globally by the MODerate-resolution Imaging Spectro-radiometer (MODIS) sensor aboard the Terra and Aqua satellites from 2000 to 2006, instanteaneous FRP values ranged between 0.02 MW and 1866 MW, with global daily means ranging between 20 and 40 MW. Regionally, at the Aqua-MODIS afternoon overpass, the mean FRP values for Alaska, Western US, Western Australia, Quebec and the rest of Canada are significantly higher than these global means, with Quebec having the overall highest value of 85 MW. Analysis of regional mean FRP per unit area of land (FRP flux) shows that a peak fire season in certain regions, fires can be responsible for up to 0.2 W/m(sup 2) at peak time of day. Zambia has the highest regional monthly mean FRP flux of approximately 0.045 W/m(sup 2) at peak time of day and season, while the Middle East has the lowest value of approximately 0.0005 W/m(sup 2). A simple scheme based on FRP has been devised to classify fires into five categories, to facilitate fire rating by strength, similar to earthquakes and hurricanes. The scheme uses MODIS measurements of FRP at 1-km resolution as follows: catagory 1 (less than 100 MW), category 2 (100 to less than 500 MW), category 3 (500 to less than 1000 MW), category 4 (1000 to less than 1500 MW), catagory 5 (greater than or equal to 1500 MW). In most regions of the world, over 90% of fires fall into category 1, while only less than 1% fall into each of categories 3 to 5, although these proportions may differ significantly from day to day and by season. The frequency of occurence of the larger fires is region specific, and could not be explained by ecosystem type alone. Time-series analysis of the propertions of higher category fires based on MODIS measured FRP from 2002 to 2006 does not show any moticeable trend because of the short time period.

[Caloric value and energy allocation of Chloris virgata in northeast grassland].

PubMed

Guo, J; Wang, R; Wang, W

2001-06-01

The rules of seasonal changes in caloric values of individual plant, stem, and leaves of Chloris virgata were similar, which had two peak values from early July to early August, and then decreased gradually. Those of inflorescence assumed U shape, and had two peak values in early August and middle September, respectively. The seasonal changes in caloric values of dead standing were irregular, and the maximum value was appeared in early August. The seasonal changes in existent energy value of the aboveground parts in Chloris virgata population presented double peak curve. The two peak values were appeared in early August and early September respectively, and the maximum value was 7381.27 kJ.m-2 in early September. The energy allocation in different seasons was leaf > stem in early July, stem > leaf > dead standing in middle July, stem > leaf > inflorescence > dead standing in August, stem > inflorescence > leaf > dead standing in early September, and stem > inflorescence > dead standing > leaf in middle September. The vertical structure of energy in the aboveground parts was that the energy value gradually increased from the earth's surface to 20 cm high, and then decreased. The maximum value, which accounted for 25.75% of energy in the aboveground parts, was appeared in the layer of 10-20 cm high. In the underground parts, the energy value progressively decreased with the increase of depth, and the maximum value, which accounted for 74.21% of energy in the underground parts, was appeared in the layer of 0-10 cm depth.

Estimating the hemodynamic influence of variable main body-to-iliac limb length ratios in aortic endografts.

PubMed

Georgakarakos, Efstratios; Xenakis, Antonios; Georgiadis, George S

2018-02-01

We conducted a computational study to assess the hemodynamic impact of variant main body-to-iliac limb length (L1/L2) ratios on certain hemodynamic parameters acting on the endograft (EG) either on the normal bifurcated (Bif) or the cross-limb (Cx) fashion. A customary bifurcated 3D model was computationally created and meshed using the commercially available ANSYS ICEM (Ansys Inc., Canonsburg, PA, USA) software. The total length of the EG, was kept constant, while the L1/L2 ratio ranged from 0.3 to 1.5 in the Bif and Cx reconstructed EG models. The compliance of the graft was modeled using a Fluid Structure Interaction method. Important hemodynamic parameters such as pressure drop along EG, wall shear stress (WSS) and helicity were calculated. The greatest pressure decrease across EG was calculated in the peak systolic phase. With increasing L1/L2 it was found that the Pressure Drop was increasing for the Cx configuration, while decreasing for the Bif. The greatest helicity (4.1 m/s2) was seen in peak systole of Cx with ratio of 1.5 whereas its greatest value (2 m/s2) was met in peak systole in the Bif with the shortest L1/L2 ratio (0.3). Similarly, the maximum WSS value was highest (2.74Pa) in the peak systole for the 1.5 L1/L2 of the Cx configuration, while the maximum WSS value equaled 2 Pa for all length ratios of the Bif modification (with the WSS found for L1/L2=0.3 being marginally higher). There was greater discrepancy in the WSS values for all L1/L2 ratios of the Cx bifurcation compared to Bif. Different L1/L2 rations are shown to have an impact on the pressure distribution along the entire EG while the length ratio predisposing to highest helicity or WSS values is also determined by the iliac limbs pattern of the EG. Since current custom-made EG solutions can reproduce variability in main-body/iliac limbs length ratios, further computational as well as clinical research is warranted to delineate and predict the hemodynamic and clinical effect of variable length ratios.

Nonlinear viscoelasticity of entangled wormlike micellar fluid under large-amplitude oscillatory shear: Role of elastic Taylor-Couette instability

NASA Astrophysics Data System (ADS)

Majumdar, Sayantan; Sood, A. K.

2014-06-01

The role of elastic Taylor-Couette flow instabilities in the dynamic nonlinear viscoelastic response of an entangled wormlike micellar fluid is studied by large-amplitude oscillatory shear (LAOS) rheology and in situ polarized light scattering over a wide range of strain and angular frequency values, both above and below the linear crossover point. Well inside the nonlinear regime, higher harmonic decomposition of the resulting stress signal reveals that the normalized third harmonic I3/I1 shows a power-law behavior with strain amplitude. In addition, I3/I1 and the elastic component of stress amplitude σ0E show a very prominent maximum at the strain value where the number density (nv) of the Taylor vortices is maximum. A subsequent increase in applied strain (γ) results in the distortions of the vortices and a concomitant decrease in nv, accompanied by a sharp drop in I3 and σ0E. The peak position of the spatial correlation function of the scattered intensity along the vorticity direction also captures the crossover. Lissajous plots indicate an intracycle strain hardening for the values of γ corresponding to the peak of I3, similar to that observed for hard-sphere glasses.

Non-Invasive Diagnosis of Portal Hypertensive Gastropathy: Quantitative Analysis of Microbubble-Induced Stomach Wall Enhancement.

PubMed

Kiyono, Soichiro; Maruyama, Hitoshi; Kobayashi, Kazufumi; Kondo, Takayuki; Sekimoto, Tadashi; Shimada, Taro; Yokosuka, Osamu; Yamaguchi, Tadashi

2016-08-01

The aim of the study described here was to elucidate the efficacy of contrast-enhanced ultrasound (CEUS) prospectively as a tool in the diagnosis of portal hypertensive gastropathy (PHG). The peak enhancement time at the upper stomach wall (PT) and intensity ratio at the upper stomach/the spleen (IR) between pre- and peak enhancement were evaluated by CEUS with perflubutane microbubble agent in 56 patients, 42 with cirrhosis (16 with PHG) and 14 controls. The IR was higher in patients with PHG (1.21 ± 0.11) than in those without (0.91 ± 0.15, p < 0.05) and the controls (0.78 ± 0.11, p < 0.01), although PT did not differ between these groups. The area under the receiver operating characteristic curve for IR was 0.8199 in the presence of PHG, with the best cutoff value of 0.94, sensitivity 65.9%, specificity 72.6%, positive predictive value 62.2%, negative predictive value 73.1% and accuracy 70.4%. CEUS may have potential as a less invasive tool for diagnosis of PHG in patients with cirrhosis. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

GH Responsiveness to Combined GH-Releasing Hormone and Arginine Administration in Obese Patients with Fibromyalgia Syndrome.

PubMed

Rigamonti, Antonello E; Grugni, Graziano; Arreghini, Marco; Capodaglio, Paolo; De Col, Alessandra; Agosti, Fiorenza; Sartorio, Alessandro

2017-01-01

Reportedly, fibromyalgia (FM) is frequently associated with reduced IGF-1 levels and GH hyporesponsiveness to different GH stimulation tests. Since there is a high prevalence of obesity in FM, and obesity itself is characterized by hyposomatotropism, the aim of this study was to assess IGF-1 levels and GH responsiveness in sixteen severely obese women suffering from FM, who, subdivided into two subgroups on the basis of their age-dependent IGF-1 values (> or <-2 SDS), underwent the combined GHRH plus arginine test. Four out of 16 obese women with FM (25%) had low IGF-1 SDS values, 2 cases of this subgroup (12.5%) failing also to normally respond to the test. Among patients with normal GH responses, 4 showed a delayed GH peak. The subgroup with low IGF-1 SDS values had higher BMI than that with normal IGF-1 SDS. GH peak and area under the curve were not correlated with CRP, ESR, or tender point score, while significant correlations were found with fat-free mass and fat mass. In conclusion, this study shows the existence of a high prevalence of GH-IGF-1 dysfunction in patients with both FM and obesity, presumably as a consequence of the obese rather than fibromyalgic condition.

Need for higher fuel burnup at the Hatch Plant

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

Beckhman, J.T.

1996-03-01

Hatch is a BWR 4 and has been in operation for some time. The first unit became commercial about 1975. Obtaining higher burnups, or higher average discharge exposures, is nothing new at Hatch. Since we have started, the discharge exposure of the plant has increased. Now, of course, we are not approaching the numbers currently being discussed but, the average discharge exposure has increased from around 20,000 MWD/MTU in the early to mid-1980s to 34,000 MWD/MTU in 1994, I am talking about batch average values. There are also peak bundle and peak rod values. You will have to make themore » conversions if you think in one way or the other because I am talking in batch averages. During Hatch`s operating history we have had some problems with fuel failure. Higher burnup fuel raises a concern about how much fuel failure you are going to have. Fuel failure is, of course, an economic issue with us. Back in the early 1980s, we had a problem with crud-induced localized corrosion, known as CILC. We have gotten over that, but we had some times when it was up around 27 fuel failures a year. That is not a pleasant time to live through because it is not what you want from an economic viewpoint or any other. We have gotten that down. We have had some fuel failures recently, but they have not been related to fuel burnup or to corrosion. In fact, the number of failures has decreased from the early 1980s to the 90s even though burnup increased during that time. The fuel failures are more debris-related-type failures. In addition to increasing burnups, utilities are actively evaluating or have already incorporated power uprate and longer fuel cycles (e.g., 2-year cycles). The goal is to balance out the higher power density, longer cycles, higher burnup, and to have no leakers. Why do we as an industry want to have higher burnup fuel? That is what I want to tell you a little bit about.« less

Sharpening of the 6.8 nm peak in an Nd:YAG laser produced Gd plasma by using a pre-formed plasma

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

Tian, Yong; Song, Xiaolin; Xie, Zhuo

For effective use of a laser-produced-plasma (LPP) light source, an LPP is desired to emit a narrow spectral peak because the reflection spectrum of multilayer mirrors for guiding emission from the source is very narrow. While a Gd plasma has been studied extensively as an extreme ultraviolet (EUV) light source at around 6.8 nm, where La/B{sub 4}C multilayer is reported to have a high reflectivity with a bandwidth of about 0.6 %, all previous works using an Nd:YAG laser reported very broad spectra. This paper reports the first narrowing of the 6.8 nm peak in the case of using anmore » Nd:YAG laser to generate a Gd plasma by using a pre-pulse. The best peak narrowing is observed when a pre-formed plasma is heated by a 1064 nm main laser pulse with a duration of 10 ns at the irradiation density of 4x 10{sup 11} W/cm{sup 2} at a delay time of 50 ns after the pre-pulse irradiation. The observed spectral width of about 0.3 nm is about one fifth of the value for no pre-formed plasma. The peak wavelength of the 6.8 nm band shifted to a longer wavelength side and the peak was broadened both for lower and higher laser irradiation density. It is discussed that this robustness of the peak position of the 6.8 nm Gd peak against temperature change is suitable to achieve a narrow bandwidth from an LPP generated on solid. The observed spectra are compared with those previously reported in various conditions.« less

Wave Field Characterization Using Dual-Polarized Pulse-Doppler X-Band Radar

DTIC Science & Technology

2012-06-01

spectrum (frequencies higher than that associated with the wind wave peak) are similar for the buoy and Doppler, and likewise for the ultrasound array and...values of the RCS and ultrasound array relative to the buoy and Doppler are due to the formers’ larger energy levels at high frequencies. NSWCCD-50-TR...pp. 199- 203, 2008. [II] W. J. Plant, W. C. Keller, A. B. Reeves, E. A. Uliana, and J. W. Johnson, " Airborne microwave Doppler measurements of

[Impacts of meteorological factors on atmospheric methane mole fractions in the background area of Yangtze River delta].

PubMed

Pu, Jing-Jiao; Xu, Hong-Hui; Gu, Jun-Qiang; Ma, Qian-Li; Fang, Shuang-Xi; Zhou, Ling-Xi

2013-03-01

Impacts of surface wind direction, surface wind speed, surface air temperature and sunshine hours on the CH4 concentration at Lin'an regional atmospheric background station were studied based on the results from Jan. 2009 to Dec. 2011. The results revealed that the diurnal variation of atmospheric CH4 concentration presented a single-peak curve at Lin'an regional background station. The diurnal amplitude varied from 19.0 x 10(-9) to 74.7 x 10(-9), with the lowest value observed in the afternoon and the highest at dawn. The monthly mean CH4 concentrations varied from 1955.7 x 10(-9) to 2036.2 x 10(-9), with the highest concentration observed in autumn and the lowest in spring. The wind directions NE-SSE could induce higher CH4 concentrations while SW-NNW wind directions had negative effects on the observed results. The CH4 concentration turned out to be lower with higher surface wind speed. With the increase of surface air temperature or sunshine hours, the CH4 concentration went up first till reaching a peak, and then decreased.

Adrenergic Receptor Polymorphism and Maximal Exercise Capacity after Orthotopic Heart Transplantation.

PubMed

Métrich, Mélanie; Mehmeti, Fortesa; Feliciano, Helene; Martin, David; Regamey, Julien; Tozzi, Piergiorgio; Meyer, Philippe; Hullin, Roger

Maximal exercise capacity after heart transplantion (HTx) is reduced to the 50-70% level of healthy controls when assessed by cardiopulmonary exercise testing (CPET) despite of normal left ventricular function of the donor heart. This study investigates the role of donor heart β1 and β2- adrenergic receptor (AR) polymorphisms for maximal exercise capacity after orthotopic HTx. CPET measured peak VO2 as outcome parameter for maximal exercise in HTx recipients ≥9 months and ≤4 years post-transplant (n = 41; mean peak VO2: 57±15% of predicted value). Donor hearts were genotyped for polymorphisms of the β1-AR (Ser49Gly, Arg389Gly) and the β2-AR (Arg16Gly, Gln27Glu). Circumferential shortening of the left ventricle was measured using magnetic resonance based CSPAMM tagging. Peak VO2 was higher in donor hearts expressing the β1-Ser49Ser alleles when compared with β1-Gly49 carriers (60±15% vs. 47±10% of the predicted value; p = 0.015), and by trend in cardiac allografts with the β1-AR Gly389Gly vs. β1-Arg389 (61±15% vs. 54±14%, p = 0.093). Peak VO2 was highest for the haplotype Ser49Ser-Gly389, and decreased progressively for Ser49Ser-Arg389Arg > 49Gly-389Gly > 49Gly-Arg389Arg (adjusted R2 = 0.56, p = 0.003). Peak VO2 was not different for the tested β2-AR polymorphisms. Independent predictors of peak VO2 (adjusted R2 = 0.55) were β1-AR Ser49Gly SNP (p = 0.005), heart rate increase (p = 0.016), and peak systolic blood pressure (p = 0.031). Left ventricular (LV) motion kinetics as measured by cardiac MRI CSPAMM tagging at rest was not different between carriers and non-carriers of the β1-AR Gly49allele. Similar LV cardiac motion kinetics at rest in donor hearts carrying either β1-AR Gly49 or β1-Ser49Ser variant suggests exercise-induced desensitization and down-regulation of the β1-AR Gly49 variant as relevant pathomechanism for reduced peak VO2 in β1-AR Gly49 carriers.

Does team lifting increase the variability in peak lumbar compression in ironworkers?

PubMed

Faber, Gert; Visser, Steven; van der Molen, Henk F; Kuijer, P Paul F M; Hoozemans, Marco J M; Van Dieën, Jaap H; Frings-Dresen, Monique H W

2012-01-01

Ironworkers frequently perform heavy lifting tasks in teams of two or four workers. Team lifting could potentially lead to a higher variation in peak lumbar compression forces than lifts performed by one worker, resulting in higher maximal peak lumbar compression forces. This study compared single-worker lifts (25-kg, iron bar) to two-worker lifts (50-kg, two iron bars) and to four-worker lifts (100-kg, iron lattice). Inverse dynamics was used to calculate peak lumbar compression forces. To assess the variability in peak lumbar loading, all three lifting tasks were performed six times. Results showed that the variability in peak lumbar loading was somewhat higher in the team lifts compared to the single-worker lifts. However, despite this increased variability, team lifts did not result in larger maximum peak lumbar compression forces. Therefore, it was concluded that, from a biomechanical point of view, team lifting does not result in an additional risk for low back complaints in ironworkers.

Aeroheating Environments for a Mars Smart Lander

NASA Technical Reports Server (NTRS)

Edquist, Karl T.; Liechty, Derek S.; Hollis, Brian R.; Alter, Stephen J.; Loomis, Mark P.

2002-01-01

A proposed Mars Smart Lander is designed to reach the surface via lifting-body atmospheric entry (alpha = 16 deg) to within 10 km of the target site. CFD (computational fluid dynamics) predictions of the forebody aeroheating environments are given for a direct entry from a 2005 launch. The solutions were obtained using an 8-species gas in thermal and chemical nonequilibrium with a radiative-equilibrium wall temperature boundary condition. Select wind tunnel data are presented from tests at NASA Langley Research Center. Turbulence effects are included to account for both smooth body transition and turbulence due to heatshield penetrations. Natural transition is based on a momentum-thickness Reynolds number value of 200. The effects of heatshield penetrations on turbulence are estimated from wind tunnel tests of various cavity sizes and locations. Both natural transition and heatshield penetrations are predicted to cause turbulence prior to the nominal trajectory peak heating time. Laminar and turbulent CFD predictions along the trajectory are used to estimate heat rates and loads. The predicted peak turbulent heat rate of 63 W/sq cm on the heatshield leeward flank is 70% higher than the laminar peak. The maximum integrated heat load for a fully turbulent heat pulse is 38% higher than the laminar load on the heatshield nose. The predicted aeroheating environments with uncertainty factors will be used to design a thermal protection system.

Hough transform method for track finding in center drift chamber

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

Azmi, K. A. Mohammad Kamal, E-mail: khasmidatul@siswa.um.edu.my; Wan Abdullah, W. A. T., E-mail: wat@um.edu.my; Ibrahim, Zainol Abidin

Hough transform is a global tracking method used which had been expected to be faster approach for tracking the circular pattern of electron moving in Center Drift Chamber (CDC), by transforming the point of hit into a circular curve. This paper present the implementation of hough transform method for the reconstruction of tracks in Center Drift Chamber (CDC) which have been generated by random number in C language programming. Result from implementation of this method shows higher peak of circle parameter value (xc,yc,rc) that indicate the similarity value of the parameter needed for circular track in CDC for charged particlesmore » in the region of CDC.« less

Exercise capacity in pediatric patients with inflammatory bowel disease.

PubMed

Ploeger, Hilde E; Takken, Tim; Wilk, Boguslaw; Issenman, Robert M; Sears, Ryan; Suri, Soni; Timmons, Brian W

2011-05-01

To examine exercise capacity in youth with Crohn's disease (CD) and ulcerative colitis (UC). Eleven males and eight females with CD and six males and four females with UC participated. Patients performed standard exercise tests to assess peak power (PP) and mean power (MP) and peak aerobic mechanical power (W(peak)) and peak oxygen uptake (VO(2peak)). Fitness variables were compared with reference data and also correlated with relevant clinical outcomes. Pediatric patients with inflammatory bowel disease had lower PP (∼90% of predicted), MP (∼88% of predicted), W(peak) (∼91% of predicted), and VO(2peak) (∼75% of predicted) compared with reference values. When patients with CD or UC were compared separately to reference values, W(peak) was significantly lower only in the CD group. No statistically significant correlations were found between any exercise variables and disease duration (r = 0.01 to 0.14, P = .47 to .95) or disease activity (r = -0.19 to -0.31, P = .11 to .38), measured by pediatric CD activity index or pediatric ulcerative colitis activity index. After controlling for chronological age, recent hemoglobin levels were significantly correlated with PP (r = 0.45, P = .049), MP (r = 0.63, P = .003), VO(2peak) (r = 0.62, P = .004), and W(peak) (r = 0.70, P = .001). Pediatric patients with inflammatory bowel disease exhibit impaired aerobic and anaerobic exercise capacity compared with reference values. Copyright © 2011 Mosby, Inc. All rights reserved.

Demonstration of the need for cardiovascular and pulmonary normative data for cancer survivors.

PubMed

Schneider, C M; Repka, C P; Brown, J M; Lalonde, T L; Dallow, K T; Barlow, C E; Hayward, R

2014-12-01

Despite evidence that cancer and its treatments severely reduce cardiorespiratory fitness (CRF), normative data for cancer survivors do not exist. The present study identifies age and gender-specific CRF distributions in a cancer population. The use of cancer-specific normative CRF data may help stratify initial fitness status and assess improvements in response to exercise interventions in cancer survivors. Data from 703 cancer survivors were analyzed for this study. Quintiles were compiled for peak oxygen consumption (VO2peak), forced vital capacity (FVC), and forced expiratory volume (FEV1) for males and females in 5 age groups (19-39, 40-49, 50-59, 60-69, and ≥70 years of age). VO2peak values for the cancer population were significantly lower than the general US population. The cancer population average in each age group fell within the "very poor" classification of VO2peak values for the general population. FVC values in the cancer population were similar to the general population. Cancer survivors had very low age group-specific VO2peak values compared to the apparently healthy general US population. Previously, CRF values of cancer survivors were compared to normative values for the apparently healthy general population, which yielded imprecise classifications of initial fitness and changes in fitness, resulting in patient discouragement. © Georg Thieme Verlag KG Stuttgart · New York.

Are gender differences in upper-body power generated by elite cross-country skiers augmented by increasing the intensity of exercise?

PubMed

Hegge, Ann Magdalen; Myhre, Kenneth; Welde, Boye; Holmberg, Hans-Christer; Sandbakk, Øyvind

2015-01-01

In the current study, we evaluated the impact of exercise intensity on gender differences in upper-body poling among cross-country skiers, as well as the associated differences in aerobic capacity, maximal strength, body composition, technique and extent of training. Eight male and eight female elite skiers, gender-matched for level of performance by FIS points, carried out a 4-min submaximal, and a 3-min and 30-sec maximal all-out test of isolated upper-body double poling on a Concept2 ski ergometer. Maximal upper-body power and strength (1RM) were determined with a pull-down exercise. In addition, body composition was assessed with a DXA scan and training during the previous six months quantified from diaries. Relative to the corresponding female values (defined as 100%), the power output produced by the men was 88%, 95% and 108% higher during the submaximal, 3-min and 30-sec tests, respectively, and peak power in the pull-down strength exercise was 118% higher (all P<0.001). During the ergometer tests the work performed per cycle by the men was 97%, 102% and 91% greater, respectively, and the men elevated their cycle rate to a greater extent at higher intensities (both P<0.01). Furthermore, men had a 61% higher VO2peak, 58% higher 1RM, relatively larger upper-body mass (61% vs 56%) and reported considerably more upper-body strength and endurance training (all P<0.05). In conclusion, gender differences in upper-body power among cross-country skiers augmented as the intensity of exercise increased. The gender differences observed here are greater than those reported previously for both lower- and whole-body sports and coincided with greater peak aerobic capacity and maximal upper-body strength, relatively more muscle mass in the upper-body, and more extensive training of upper-body strength and endurance among the male skiers.

Are Gender Differences in Upper-Body Power Generated by Elite Cross-Country Skiers Augmented by Increasing the Intensity of Exercise?

PubMed Central

Hegge, Ann Magdalen; Myhre, Kenneth; Welde, Boye; Holmberg, Hans-Christer; Sandbakk, Øyvind

2015-01-01

In the current study, we evaluated the impact of exercise intensity on gender differences in upper-body poling among cross-country skiers, as well as the associated differences in aerobic capacity, maximal strength, body composition, technique and extent of training. Eight male and eight female elite skiers, gender-matched for level of performance by FIS points, carried out a 4-min submaximal, and a 3-min and 30-sec maximal all-out test of isolated upper-body double poling on a Concept2 ski ergometer. Maximal upper-body power and strength (1RM) were determined with a pull-down exercise. In addition, body composition was assessed with a DXA scan and training during the previous six months quantified from diaries. Relative to the corresponding female values (defined as 100%), the power output produced by the men was 88%, 95% and 108% higher during the submaximal, 3-min and 30-sec tests, respectively, and peak power in the pull-down strength exercise was 118% higher (all P<0.001). During the ergometer tests the work performed per cycle by the men was 97%, 102% and 91% greater, respectively, and the men elevated their cycle rate to a greater extent at higher intensities (both P<0.01). Furthermore, men had a 61% higher VO2peak, 58% higher 1RM, relatively larger upper-body mass (61% vs 56%) and reported considerably more upper-body strength and endurance training (all P<0.05). In conclusion, gender differences in upper-body power among cross-country skiers augmented as the intensity of exercise increased. The gender differences observed here are greater than those reported previously for both lower- and whole-body sports and coincided with greater peak aerobic capacity and maximal upper-body strength, relatively more muscle mass in the upper-body, and more extensive training of upper-body strength and endurance among the male skiers. PMID:26000713

Seasonal patterns of periphyton nitrogen fixation in calcareous wetlands

NASA Astrophysics Data System (ADS)

Liao, X.; Inglett, P.

2011-12-01

Periphyton mats are an ecologically important component of the Everglades ecosystem and plays various vital ecological functions. However, nitrogen fixation of periphyton, has received little attention throughout much of the Everglades system. The objective of this study was to characterize the seasonal pattern of periphyton N2 fixation in the Hole-in-the-Donut (HID) of Florida Everglades, where farmed marl prairie wetlands have been restored through complete soil removal (CSR) to reduce nutrient levels. Two restored areas (i.e., cleared in 2000 and 2003) and a reference (natural and unfarmed) marl prairie wetland sites were selected in the HID. Seven times of sampling were performed across the wet and dry season during the 2010 and 2011. The annual fixed nitrogen was approximately 0.4gN m-2 yr-1 in the restored sites which was higher in the reference site (~0.2gN m-2 yr-1). All the three sites showed similar seasonal patterns of N2 fixation that is higher values were observed in the wet season; but the peak value was one month later in reference sits (i.e., September) comparing to the restored areas (i.e., July). The peak of periphyton AR rates in the 2000- and 2003-restored areas appeared in July (i.e., wet season) within the range of 20-79 nmols g-1dw h-1 and 31-53nmols g-1dw h-1, respectively. In contrast, the peak of reference site was observed in September with the range of 2-5 nmols g-1dw h-1. Stable N isotopic ratios (i.e., δ15N) also varied with time but didn't show consistent seasonal pattern as nitrogen fixation. N2 fixation positively correlated with periphyton total phosphorus (TP) and negatively correlated with total nitrogen and phosphorus molar ratios (TN:TP), indicating that N2 fixation would be a indicator of nutrient limitation. In general, δ15N was negatively correlated with nitrogenase activity but the correlation became weakened in the wet season, especially in the flooded July and September, which would be explained by other environmental factors and higher denitrification activities in that time.

Lead isotopic evidence for mixed sources of Proterozoic granites and pegmatites, Black Hills, South Dakota, USA

NASA Astrophysics Data System (ADS)

Krogstad, Eirik J.; Walker, Richard J.; Nabelek, Peter I.; Russ-Nabelek, Carol

1993-10-01

The lead isotopic compositions of K-feldspars separated from the ca. 1700 Ma Harney Peak Granite complex and spatially associated granitic pegmatites indicate that these rocks were derived from at least two sources. It has been reported previously that the core of the Harney Peak Granite complex is dominated by relatively lower/ gd18O (avg. 11.5 %.) granites, whereas higher / gd18O (avg. 13.2%.) granites occur around the periphery of the complex. The higher δ 18O granites and one simple pegmatite have low values of 207Pb /204Pb for their 206Pb /204Pb Thus, they likely were derived from a source with a short crustal residence time. This source may have been the pelitic schists into which the Harney Peak Granite complex and pegmatites were intruded. Feldspars from granites with lower / gd18O values have significantly higher 207Pb /204Pb for their 206Pb /204Pb . The data define a linear array with a slope equivalent to an age of ca. 2.6 Ga with t 2 defined to be 1.7 Ga. Such a slope could represent a mixing array or a secondary isochron for the source. These low δ18O granites could have been derived from a source with a high U/ Pb and with a crustal residence beginning before the Proterozoic. The source (s) of these granites may have been a sediment derived from late Archean continental crust. The highly evolved Tin Mountain pegmatite has lead isotopic systematics intermediate between those of the two granite groups, suggesting either a mixed source or contamination. Two late Archean granites, the Little Elk Granite and the Bear Mountain Granite, had precursors with high U/Pb and low Th/U histories. The Th/U history of the Bear Mountain Granite is too low for this rock to have been an important component of the source of the Proterozoic granites. However, crustal rocks with lead isotopic compositions similar to those of the Little Elk Granite were an important source of lead for some of the Proterozoic granitic rocks.

Alpha-actinin-3 (ACTN3) R577X polymorphism influences knee extensor peak power response to strength training in older men and women.

PubMed

Delmonico, Matthew J; Kostek, Matthew C; Doldo, Neil A; Hand, Brian D; Walsh, Sean; Conway, Joan M; Carignan, Craig R; Roth, Stephen M; Hurley, Ben F

2007-02-01

The alpha-actinin-3 (ACTN3) R577X polymorphism has been associated with muscle power performance in cross-sectional studies. We examined baseline knee extensor concentric peak power (PP) and PP change with approximately 10 weeks of unilateral knee extensor strength training (ST) using air-powered resistance machines in 71 older men (65 [standard deviation = 8] years) and 86 older women (64 [standard deviation = 9] years). At baseline in women, the XX genotype group had an absolute (same resistance) PP that was higher than the RR (p =.005) and RX genotype groups (p =.02). The women XX group also had a relative (70% of one-repetition maximum [1-RM]) PP that was higher than that in the RR (p =.002) and RX groups (p =.008). No differences in baseline absolute or relative PP were observed between ACTN3 genotype groups in men. In men, absolute PP change with ST in the RR (n = 16) group approached a significantly higher value than in the XX group (n = 9; p =.07). In women, relative PP change with ST in the RR group (n = 16) was higher than in the XX group (n = 17; p =.02). The results indicate that the ACTN3 R577X polymorphism influences the response of quadriceps muscle power to ST in older adults.

Pump out the volume--The effect of tracheal and subelytral pressure pulses on convective gas exchange in a dung beetle, Circellium bacchus (Fabricus).

PubMed

Duncan, Frances D; Förster, Thomas D; Hetz, Stefan K

2010-05-01

Many flightless beetles like the large apterous dung beetle Circellium bacchus, possess a subelytral cavity (SEC) providing an extra air space below the elytra which connects to the tracheal system (TS) via metathoracic and abdominal spiracles. By measuring subelytral and intratracheal pressure as well as body movements and gas exchange simultaneously in a flow-through setup, we investigated the contribution of convection on Circellium respiratory gas exchange. No constriction phase was observed. TS and SEC pressures were always around atmospheric values. During interburst phase open abdominal spiracles and a leaky SEC led to small CO(2)-peaks on a continuous CO(2) baseline, driven by intermittent positive tracheal pressure peaks in anti-phase with small negative subelytral pressure peaks caused by dorso-ventral tergite action. Spiracle opening was accompanied by two types of body movements. Higher frequency telescoping body movements at the beginning of opening resulted in high amplitude SEC and TS pressure peaks. High frequency tergite movements caused subelytral pressure peaks and led to a saw tooth like CO(2) release pattern in a burst. We propose that during the burst open mesothoracic spiracles increase the compliance of the subelytral cavity allowing big volumes of tracheal air being pulled out by convection. Copyright 2009 Elsevier Ltd. All rights reserved.

The effect of habitual waterpipe tobacco smoking on pulmonary function and exercise capacity in young healthy males: A pilot study.

PubMed

Hawari, F I; Obeidat, N A; Ghonimat, I M; Ayub, H S; Dawahreh, S S

2017-01-01

Evidence regarding the health effects of habitual waterpipe smoking is limited, particularly in young smokers. Respiratory health and cardiopulmonary exercise tests were compared in young male habitual waterpipe smokers (WPS) versus non-smokers. 69 WPS (≥3 times/week for three years) and 69 non-smokers were studied. Respiratory health was assessed through the American Thoracic Society and the Division of Lung Diseases (ATS-DLD-78) adult questionnaire. Pulmonary function and cardiopulmonary exercise tests were performed. Self-reported respiratory symptoms, forced expiratory volume in first second (FEV 1 ), forced vital capacity (FVC), FEV 1 /FVC ratio, forced expiratory flow between 25 and 75% of FVC (FEF 25-75% ), peak expiratory flow (PEF), exercise time, peak end-tidal CO 2 tension (PetCO 2 ), subject-reported leg fatigue and dyspnea; peak O 2 uptake (VO 2 max), and end-expiratory lung volume (EELV) change from baseline (at peak exercise) were measured. WPS were more likely than non-smokers to report respiratory symptoms. WPS also demonstrated: shorter exercise time; lower peak VO 2 ; higher perceived dyspnea at mid-exercise; lower values of the following: FEV 1 , FVC, PEF, and EELV change. Habitual waterpipe tobacco smoking in young seemingly healthy individuals is associated with a greater burden of respiratory symptoms and impaired exercise capacity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Features of Patients With Severe Hepatitis Due to Mushroom Poisoning and Factors Associated With Outcome.

PubMed

Bonacini, Maurizio; Shetler, Katerina; Yu, Ira; Osorio, Robert C; Osorio, Robert W

2017-05-01

Acute liver failure after ingestion of toxic mushrooms is a significant medical problem. Most exposures to toxic mushrooms produce no symptoms or only mild gastroenteritis, but some lead to severe hepatic necrosis and fulminant hepatic failure requiring liver transplantation. We aimed to assess mortality from mushroom poisoning and identify variables associated with survival and liver transplantation. We collected information from 27 patients (13 male; median age, 47 years) admitted to the emergency department within 24 hours of ingesting wild mushrooms. They developed severe liver injury (serum levels of transaminases greater than 400 IU/L) and were treated with activated charcoal and N-acetylcysteine at a tertiary medical center in San Francisco, California from January 1997 through December 2014. Viral hepatitis, autoimmune liver disease, acetaminophen, salicylate toxicity, and chronic liver diseases were ruled out for all patients. We analyzed patient demographics, time since ingestion, presenting symptoms, laboratory values, and therapies administered. A good outcome was defined as survival without need for liver transplant. A poor outcome was defined as death or liver transplant. Positive predictive values were calculated, and the χ 2 test was used to analyze dichotomous variables. Liver injury was attributed to ingestion of Amanita phalloides in 24 patients and Amanita ocreata in 3 patients. Twenty-four of the patients ingested mushrooms with meals and 3 patients for hallucinogenic purpose. At 24-48 hours after ingestion, all patients had serum levels of alanine aminotransferase ranging from 554 to 4546 IU/L (median, 2185 IU/L). Acute renal impairment developed in 5 patients. Twenty-three patients survived without liver transplantation, and 4 patients had poor outcomes (1 woman underwent liver transplantation on day 20 after mushroom ingestion, and 3 women died of hepatic failure). Of the 23 patients with peak levels of total bilirubin of 2 mg/dL or more during hospitalization, only 4 had a poor outcome. Peak serum level of aspartate aminotransferase less than 4000 IU/L, peak international normalized ratio less than 2, and a value of serum factor V greater than 30% identified patients with good outcomes with 100% positive predictive value; if these peak values were used as a cutoff, 10 of 27 patients (37%), 7 of 27 patients (26%), and 6 of 12 patients (50%), respectively, could have avoided transfer to a transplant center. In an analysis of 27 patients with hepatocellular damage due to mushroom (Amanita) poisoning and peak levels of total bilirubin greater than 2 mg/dL, the probability of liver transplantation or death is 17%, fulfilling Hy's law. Patients with peak levels of aspartate aminotransferase less than 4000 IU/L can be monitored in a local hospital, whereas patients with higher levels should be transferred to liver transplant centers. Women and older patients were more likely to have a poor outcome than men and younger patients. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Performance, Facility Pressure Effects, and Stability Characterization Tests of NASA's Hall Effect Rocket with Magnetic Shielding Thruster

NASA Technical Reports Server (NTRS)

Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Yim, John; Herman, Daniel; Peterson, Peter Y.; Williams, George J.; Gilland, James; Hofer, Richard; Mikellides, Ioannis

2016-01-01

NASA's Hall Effect Rocket with Magnetic Shielding (HERMeS) 12.5 kW Technology Demonstration Unit-1 (TDU-1) has been the subject of extensive technology maturation in preparation for flight system development. Part of the technology maturation effort included experimental evaluation of the TDU-1 thruster with conducting and dielectric front pole cover materials in two different electrical configurations. A graphite front magnetic pole cover thruster configuration with the thruster body electrically tied to cathode, and an alumina front pole cover thruster configuration with the thruster body floating were evaluated. Both configurations were also evaluated at different facility background pressure conditions to evaluate background pressure effects on thruster operation. Performance characterization tests found that higher thruster performance was attained with the graphite front pole cover configuration with the thruster electrically tied to cathode. A total thrust efficiency of 68% and a total specific impulse of 2,820 s was demonstrated at a discharge voltage of 600 V and a discharge power of 12.5 kW. Thruster stability regimes were characterized with respect to the thruster discharge current oscillations and with maps of the discharge current-voltage-magnetic field (IVB). Analysis of TDU-1 discharge current waveforms found that lower normalized discharge current peak-to-peak and root mean square magnitudes were attained when the thruster was electrically floated with alumina front pole covers. Background pressure effects characterization tests indicated that the thruster performance and stability were mostly invariant to changes in the facility background pressure for vacuum chamber pressure below 1×10-5 Torr-Xe (for thruster flow rates of 20.5 mg/s). Power spectral density analysis of the discharge current waveforms showed that increasing the vacuum chamber background pressure resulted in a higher discharge current dominant breathing mode frequency. Finally, IVB maps of the TDU-1 thruster indicated that the discharge current became more oscillatory with higher discharge current peak-to-peak and RMS values with increased facility background pressure at lower thruster mass flow rates; thruster operation at higher flow rates resulted in less change to the thruster's IVB characteristics with elevated background pressure.

Prediction of peak response values of structures with and without TMD subjected to random pedestrian flows

NASA Astrophysics Data System (ADS)

Lievens, Klaus; Van Nimmen, Katrien; Lombaert, Geert; De Roeck, Guido; Van den Broeck, Peter

2016-09-01

In civil engineering and architecture, the availability of high strength materials and advanced calculation techniques enables the construction of slender footbridges, generally highly sensitive to human-induced excitation. Due to the inherent random character of the human-induced walking load, variability on the pedestrian characteristics must be considered in the response simulation. To assess the vibration serviceability of the footbridge, the statistics of the stochastic dynamic response are evaluated by considering the instantaneous peak responses in a time range. Therefore, a large number of time windows are needed to calculate the mean value and standard deviation of the instantaneous peak values. An alternative method to evaluate the statistics is based on the standard deviation of the response and a characteristic frequency as proposed in wind engineering applications. In this paper, the accuracy of this method is evaluated for human-induced vibrations. The methods are first compared for a group of pedestrians crossing a lightly damped footbridge. Small differences of the instantaneous peak value were found by the method using second order statistics. Afterwards, a TMD tuned to reduce the peak acceleration to a comfort value, was added to the structure. The comparison between both methods in made and the accuracy is verified. It is found that the TMD parameters are tuned sufficiently and good agreements between the two methods are found for the estimation of the instantaneous peak response for a strongly damped structure.

Stable isotope ratio analysis of breastfeeding and weaning practices of children from medieval Fishergate House York, UK.

PubMed

Burt, Nicole M

2013-11-01

Rib collagen of 51 juveniles and 11 adult females from the late medieval Fishergate House cemetery site (York, UK) were analyzed using nitrogen and carbon stable isotope ratio analysis to determine the weaning age for this population and to reconstruct diet. The juveniles' ages ranged from fetal to 5-6 years, while the females were of reproductive age. Previous researchers suggested that the children from Fishergate House might have been weaned later than the medieval British norm of 2 years, based on a mortality peak at 4-6 years of age. The results show weaning was complete by 2 years of age, agreeing with previous British weaning studies. The adult female δ(15) N values have a mean of 11.4‰ ± 1.1‰ and the δ(13) C values have a mean of -19.4‰ ± 0.4‰. These findings are consistent with previous isotopic studies of female diet in York during this period, though slightly lower. The weaned juvenile nitrogen values were found to be higher than the adult females (12.4‰ ± 1.0‰ for δ(15) N and -19.7‰ ± 0.5‰ for δ(13) C), which might indicate a dependence on higher trophic level proteins such as marine fish or pork. Marine fish is considered a high status food and children are considered low-status individuals at this time, making this a particularly interesting finding. Weaning does not appear to coincide with peak mortality, suggesting environment factors may be playing a larger role in child mortality at Fishergate House. Copyright © 2013 Wiley Periodicals, Inc.

[The lh-rh-test in men with fertility disorders (author's transl)].

PubMed

Krause, W; Höbel, W

1976-11-01

89 mal patients with fertility disorders underwent a test with 50 mug synthetic LH-RH. The basal levels of FSH and LH are elevated in patients with azoospermia, with testicular atrophy, varicocele and Klinefelters syndrome. They increase with age. After stimulation with LH-RH the highest relative peaks (maximal value divided by control value) of LH are seen younger patients, in those with varicocele, and oligozoospermia. The FSH-values do not differ significantly between these groups. Low relative peaks of LH are seen in older patients. In Klinefelter's syndrome the relative peaks of FSH and LH are significantly lowered.

Inlet Flow Characteristics During Rapid Maneuvers for an F/A-18A Airplane

NASA Technical Reports Server (NTRS)

Steenken, William G.; Williams, John G.; Walsh, Kevin R.

1999-01-01

The F404-GE-400 engine powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the characteristics of inlet airflow during rapid aircraft maneuvers. A study of the degree of similarity between inlet data obtained during rapid aircraft maneuvers and inlet data obtained at steady aerodynamic attitudes was conducted at the maximum engine airflow of approximately 145 Ibm/sec using a computer model that was generated from inlet data obtained during steady aerodynamic maneuvers. Results show that rapid-maneuver inlet recoveries agreed very well with the recoveries obtained at equivalent stabilized angle-of-attack conditions. The peak dynamic circumferential distortion values obtained during rapid maneuvers agreed within 0.01 units of distortion over the 10 - 38 degree angle of attack range with the values obtained during steady aerodynamic maneuvers while similar agreement was found for the peak dynamic radial distortion values up to 29 degrees angle-of-attack. Exceedences of the rapid-maneuver peak dynamic circumferential distortion values relative to the peak distortion model values at steady attitudes occurred only at low or negative angles of attack and were inconsequential from an engine-stability assessment point of view. The results of this study validate the current industry practice of testing at steady aerodynamic conditions to characterize inlet recovery and peak dynamic distortion levels.

BMI Trajectories from Birth to Young Adulthood.

PubMed

McGinty, Shannon M; Osganian, Stavroula K; Feldman, Henry A; Milliren, Carly E; Field, Alison E; Richmond, Tracy K

2018-06-01

This study aimed to compare BMI trajectories from childhood to early adulthood in those with overweight and/or obesity versus severe obesity. Longitudinal BMI values (2,542 measurements) were calculated from measured heights and weights for 103 children, adolescents, or young adults with overweight, obesity, or severe obesity. Segmented regression with splines was used to model BMI trajectories. Sixty-nine participants were classified as ever having severe obesity versus 34 who never had severe obesity. Trajectories and slopes did not differ by sex or race/ethnicity. Compared with those who never had severe obesity, BMI was higher in the group with severe obesity at all ages, and BMI slope was higher for those with severe obesity at age 14 (P = 0.002), with peak slope occurring later (18 years vs. 16 years) and higher (4.5 ± 0.5 kg/m 2 /y vs. 2.9 ± 0.5 kg/m 2 /y; P < 0.02). In the group without severe obesity, BMI fell below zero by the mid-20s (-0.3 ± 0.6 kg/m 2 /y); in those with severe obesity, BMI slope never reached zero (0.9 ± 0.5 kg/m 2 /y). Youth with severe obesity, compared with their peers without, started with higher BMIs, had more rapid rates of BMI increase beginning at age 14, as well as a higher peak and longer period of increase, and never achieved weight stabilization. © 2018 The Obesity Society.

Severe hypercalcaemia and hypophosphataemia with an optimised preterm parenteral nutrition formulation in two epochs of differing phosphate supplementation.

PubMed

Mulla, Shaveta; Stirling, Susan; Cowey, Sarah; Close, Rosie; Pullan, Sara; Howe, Rosalind; Radbone, Lynne; Clarke, Paul

2017-09-01

To compare in two epochs of differing phosphate provision serum calcium, phosphate, potassium, and sodium concentrations and the frequency of abnormality of these electrolytes and of sepsis in preterm infants who received an optimised higher amino acid-content formulation. Retrospective cohort study at a single tertiary-level neonatal unit. Preterm infants given parenteral nutrition (PN) in the first postnatal week during two discrete 6-month epochs in 2013-2014. In epoch 1 the Ca 2+ :PO 4 molar ratio of the PN formulation was ~1.3-1.5:1 (1.7 mmol Ca 2+ and 1.1 mmol PO 4 per 100 mL aqueous phase) and in epoch 2 was 1.0:1 via extra phosphate supplementation (1.7 mmol Ca 2+ and 1.7 mmol PO 4 per 100 mL). Peak calcium and nadir phosphate and potassium concentrations, and proportions with severe hypercalcaemia (Ca 2+ >3.0 mmol/L), hypophosphataemia (PO 4 <1.5 mmol/L), and hypokalaemia (K + <3.5 mmol/L) within the first postnatal week. In epoch 2, peak calcium concentrations were lower than in epoch 1 (geometric means: 2.83 mmol/L vs 3.09 mmol/L, p value<0.0001), fewer babies were severely hypercalcaemic (10/49, 20%, vs 31/51, 61%, p value<0.0001); nadir plasma phosphate concentrations were higher (means: 1.54 mmol/L vs 1.32 mmol/L, p value=0.006), and there were fewer cases of hypophosphataemia (17/49, 35% vs 31/51, 61%, p value=0.009) and hypokalaemia (12/49, 25% vs 23/51, 45%, p value=0.03). Reverting from a PN Ca 2+ :PO 4 molar ratio of 1.3-1.5:1 to a ratio of 1.0:1 was associated with a lower incidence and severity of hypophosphataemia and hypercalcaemia. For preterm infants given higher concentrations of amino acids (≥2.5 g/kg/day) from postnatal day 1, an equimolar Ca 2+ :PO 4 ratio may be preferable during the first postnatal week. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

MR spectroscopy of intracranial tuberculomas: A singlet peak at 3.8 ppm as potential marker to differentiate them from malignant tumors

PubMed Central

Alfaro, David; Martinot, Carlos; Fayed, Nicolas; Gaskill-Shipley, Mary

2015-01-01

Purpose The diagnosis of intracranial tuberculomas is often challenging. Our purpose is to describe the most common metabolic patterns of tuberculomas by MR spectroscopy (MRS) with emphasis on potential specific markers. Methods Single-voxel MRS short echo time was performed in 13 cases of tuberculomas proven by histology and/or response to anti-mycobacterial therapy. For comparison MRS was also performed in 19 biopsy-proven malignant tumors (13 high-grade gliomas and six metastasis). Presence of metabolic peaks was assessed visually and categorical variables between groups were compared using chi-square. Metabolite ratios were compared using Mann-Whitney test and diagnostic accuracy of the metabolite ratios was compared using receiver-operating characteristic (ROC) curves analysis. Results Spectroscopic peaks representing lipids and glutamate/glutamine (Glx) as well as a peak at ∼3.8 ppm were well defined in 77% (10/13), 77% (10/13) and 69% (nine of 13) of tuberculomas, respectively. Lipid and Glx peaks were also present in most of the malignant lesions, 79% (15/19) and 74% (14/19) respectively. However, a peak at ∼3.8 ppm was present in only 10% (two of 19) of the tumor cases (p < 0.001). Higher Cho/Cr and mI/Cr ratios helped discriminate malignant lesions with an area under the ROC curve of 0.86 (SE: 0.078, p < 0.002, CI: 0.7–1) and 0.8 (SE: 0.1, p < 0.009, CI: 0.6–1), respectively. Threshold values between 1.7–1.9 for Cho/Cr and 0.8–0.9 for mI/Cr provided high specificity (91% for both metabolites) and adequate sensitivity (75% and 80%, respectively) for discrimination of malignant lesions. Conclusion A singlet peak at ∼3.8 ppm is present in the majority of tuberculomas and absent in most malignant tumors, potentially a marker to differentiate these lesions. The assignment of the peak is difficult from our analysis; however, guanidinoacetate (Gua) is a possibility. Higher Cho/Cr and mI/Cr ratios should favor malignant lesions over tuberculomas. The presence of lipids and Glx is non-specific. PMID:26246099

Pressure Effect on the Boson Peak in Deeply Cooled Confined Water: Evidence of a Liquid-Liquid Transition.

PubMed

Wang, Zhe; Kolesnikov, Alexander I; Ito, Kanae; Podlesnyak, Andrey; Chen, Sow-Hsin

2015-12-04

The boson peak in deeply cooled water confined in nanopores is studied to examine the liquid-liquid transition (LLT). Below ∼180  K, the boson peaks at pressures P higher than ∼3.5  kbar are evidently distinct from those at low pressures by higher mean frequencies and lower heights. Moreover, the higher-P boson peaks can be rescaled to a master curve while the lower-P boson peaks can be rescaled to a different one. These phenomena agree with the existence of two liquid phases with different densities and local structures and the associated LLT in the measured (P, T) region. In addition, the P dependence of the librational band also agrees with the above conclusion.

Pressure Effect on the Boson Peak in Deeply Cooled Confined Water: Evidence of a Liquid-Liquid Transition

DOE PAGES

Wang, Zhe; Kolesnikov, Alexander I.; Ito, Kanae; ...

2015-12-03

We studied the boson peak in deeply cooled water confined in nanopores in order to examine the liquid-liquid transition (LLT). Below ~180 K, the boson peaks at pressures P higher than ~3.5 kbar are evidently distinct from those at low pressures by higher mean frequencies and lower heights. Moreover, the higher-P boson peaks can be rescaled to a master curve while the lower-P boson peaks can be rescaled to a different one. Moreover, these phenomena agree with the existence of two liquid phases with different densities and local structures and the associated LLT in the measured (P, T) region. Additionally,more » the P dependence of the librational band also agrees with the above conclusion.« less

Reduced channel conveyance on the Wichita River at Wichita Falls, Texas, 1900-2009

USGS Publications Warehouse

Winters, Karl; Baldys, Stanley; Schreiber, Russell

2010-01-01

Recent floods on the Wichita River at Wichita Falls, Texas, have reached higher stages compared to historical floods of similar magnitude discharges. The U.S. Geological Survey (USGS) has operated streamflow-gaging station 07312500 Wichita River at Wichita Falls, Tex., since 1938 and flood measurements near the location of the present gage were first made in 1900. Floods recorded in 2007 and 2008 at this gaging station, including the record flood of June 30, 2007, reached higher stages compared to historical floods before 1972 of similar peak discharges. For flood measurements made at stages of more than 18 feet, peak stages were about 1 to 3 feet higher compared to peak stages of similar peak discharges measured before 1972. Flood measurements made at stages of more than 18 feet also indicate a decrease in the measured mean velocity from about 3.5 to about 2.0 feet per second from 1941 to 2008. The increase in stage and decrease in streamflow velocity for similar magnitude floods indicates channel conveyance has decreased over time. A study to investigate the causes of reduced channel conveyance in the Wichita River reach from Loop 11 downstream to River Road in Wichita Falls was done by the USGS in cooperation with the City of Wichita Falls. Historical photographs indicate substantial growth of riparian vegetation downstream from Loop 11 between 1950 and 2009. Aerial photographs taken between 1950 and 2008 also indicate an increase in riparian vegetation. Twenty-five channel cross sections were surveyed by the USGS in this reach in 2009. These cross sections were located at bridge crossings or collocated with channel cross sections previously surveyed in 1986 for use in a floodplain mapping study by the Federal Emergency Management Agency. Four channel cross sections 3,400 to 11,900 feet downstream from Martin Luther King Jr. Boulevard indicate narrowing of the channel. The remaining channel cross sections surveyed in 2009 by the USGS compared favorably with cross sections surveyed in 1986 for the Federal Emergency Management Agency, with no substantial differences noted. Comparison of channel cross sections surveyed in 2009 to those from historic bridge plans indicate no change in cross section has occurred at most of the bridges from Loop 11 downstream to River Road in Wichita Falls, except for obstructions noted at the Scott Avenue bridge and Martin Luther King Jr. bridge. Although obstructions in the channel at these bridges only partially block flow, they could also be contributing to reduced channel conveyance. Step-backwater profiles were used by the USGS to verify channel roughness. The main channel roughness coefficients (Manning's n values) from 2009 surveys were virtually unchanged from those used in a 1991 hydraulic model done for the Federal Emergency Management Agency. The average overbank roughness coefficient (Manning's n value) was 0.15, more than double the value of 0.06 used in the 1991 hydraulic model. Increased overbank vegetation has resulted in higher stages conveying the same amount of discharge, particularly for discharges more than 4,000 cubic feet per second.

Decadal oscillations and extreme value distribution of river peak flows in the Meuse catchment

NASA Astrophysics Data System (ADS)

De Niel, Jan; Willems, Patrick

2017-04-01

In flood risk management, flood probabilities are often quantified through Generalized Pareto distributions of river peak flows. One of the main underlying assumptions is that all data points need to originate from one single underlying distribution (i.i.d. assumption). However, this hypothesis, although generally assumed to be correct for variables such as river peak flows, remains somehow questionable: flooding might indeed be caused by different hydrological and/or meteorological conditions. This study confirms these findings from previous research by showing a clear indication of the link between atmospheric conditions and flooding for the Meuse river in The Netherlands: decadal oscillations of river peak flows can (at least partially) be attributed to the occurrence of westerly weather types. The study further proposes a method to take this correlation between atmospheric conditions and river peak flows into account when calibrating an extreme value distribution for river peak flows. Rather than calibrating one single distribution to the data and potentially violating the i.i.d. assumption, weather type depending extreme value distributions are derived and composed. The study shows that, for the Meuse river in The Netherlands, such approach results in a more accurate extreme value distribution, especially with regards to extrapolations. Comparison of the proposed method with a traditional extreme value analysis approach and an alternative model-based approach for the same case study shows strong differences in the peak flow extrapolation. The design-flood for a 1,250 year return period is estimated at 4,800 m3s-1 for the proposed method, compared with 3,450 m3s-1 and 3,900 m3s-1 for the traditional method and a previous study. The methods were validated based on instrumental and documentary flood information of the past 500 years.

Wave propagation in fiber composite laminates, part 2

NASA Technical Reports Server (NTRS)

Daniel, I. M.; Liber, T.

1976-01-01

An experimental investigation was conducted to determine the wave propagation characteristics, transient strains and residual properties in unidirectional and angle-ply boron/epoxy and graphite/epoxy laminates impacted with silicone rubber projectiles at velocities up to 250 MS-1. The predominant wave is flexural, propagating at different velocities in different directions. In general, measured wave velocities were higher than theoretically predicted values. The amplitude of the in-plane wave is less than ten percent of that of the flexural wave. Peak strains and strain rates in the transverse to the (outer) fiber direction are much higher than those in the direction of the fibers. The dynamics of impact were also studied with high speed photography.

Chemical composition and physicochemical properties of green banana (Musa acuminata x balbisiana Colla cv. Awak) flour.

PubMed

Haslinda, W H; Cheng, L H; Chong, L C; Noor Aziah, A A

2009-01-01

Flour was prepared from peeled and unpeeled banana Awak ABB. Samples prepared were subjected to analysis for determination of chemical composition, mineral, dietary fibre, starch and total phenolics content, antioxidant activity and pasting properties. In general, flour prepared from unpeeled banana was found to show enhanced nutrition values with higher contents of mineral, dietary fibre and total phenolics. Hence, flour fortified with peel showed relatively higher antioxidant activity. On the other hand, better pasting properties were shown when banana flour was blended with peel. It was found that a relatively lower pasting temperature, peak viscosity, breakdown, final viscosity and setback were evident in a sample blended with peel.

A comparative study of oak (Quercus, Fagaceae) seedling physiology during summer drought in southern California.

PubMed

Mahall, Bruce E; Tyler, Claudia M; Cole, E Shelly; Mata, Catarina

2009-04-01

Natural recruitment of oaks appears to be declining throughout the northern hemisphere. Summer drought poses a potentially important barrier to oak recruitment in southern California. To evaluate this barrier, we grew evergreen Quercus agrifolia and deciduous Q. lobata from seeds near parental trees. We measured water relations, chlorophyll fluorescence, and gas exchange during these seedlings' fourth and fifth summers and compared them to neighboring adults. Most seedlings had substantially lower values for predawn xylem pressure potential (Ψ(pd)), minimum photosystem II (PSII) quantum efficiency (Φ(PSIIMIN)), maximum quantum efficiency for PSII under dark-adapted leaf conditions (Fv/Fm), and maximum photosynthetic assimilation (Amax), and higher values for maximum nonphotochemical quenching (NPQmax) than did conspecific adults. The high, unvarying Ψ(pd) values of the adults suggest they use perennially available groundwater. Quercus lobata seedlings commonly had lower values for Ψ(pd) than did Q. agrifolia, and values for Ψ(pd) and Φ(PSIIMIN) were significantly related to size in Q. lobata but not in Q. agrifolia. These data suggest important interspecific differences in root architecture. Lower values for Φ(PSIIMIN), Fv/Fm, and higher NPQmax in Q. agrifolia indicate that Q. agrifolia seedlings were usually under more stress than Q. lobata, which typically had higher Amax rates than did Q. agrifolia seedlings. Diurnal photosynthesis curves were quite flat for Q. agrifolia, but they peaked in the morning for Q. lobata. Established seedlings appeared to be under more stress than adults, but this stress did not appear severe enough to cause death. Access to perennially available groundwater may be crucial for the seedling to sapling transition.

The Designs of Fins Air-Cooled Cylinders

DTIC Science & Technology

1939-06-28

4 (a). EMer part of figure 4 clearly shows that, for one pnir of values of s and t, the heat transfer is a maximum. The peak values of the curves of...specified s” curves. Similarly, the peak values of the curves of constant values of t shown in &ure 4 (b) and of similar cwwes plotted for othm values of... picking the values of optimum g and t from these curves: PIots of tk type shown in figure 4 were obtained for - other \\ralues of M and Aplpa,/m by means

Pulmonary function abnormalities associated with exposure to automobile exhaust in a diesel bus garage and roads.

PubMed

Chattopadhyay, B P; Alam, J; Roychowdhury, A

2003-01-01

In Kolkata city the road transports are maintained by private and Government organization. A major work force belonged to the State Transport Corporation (KSTC), Government of West-Bengal. The pollution caused by these vehicles affects the workers health and caused different types of respiratory problems. This study was undertaken to assess the pulmonary function status of these workers. City KSTC garage workers were investigated and categorically divided into two group: garage mechanics and the (2) those transporting the passengers (drivers and conductors). Vital capacity (VC), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were recorded by Spirovit-SP-10 (Schiller Ltd, Switzerland) and Wright's Peak Flow Meter (UK) on 236 workers. The different flow volumes, FEV(1), FEV(1%), and flow rates, FEF(02-121), FEF(25-75%), etc. were calculated. The administrative people had higher PFT than the other categories. Drivers and conductors have almost equal mean PFT values but mechanical workers had slightly higher. PFT values according to different age ranges and duration of exposure showed gradual decrement as age and duration of exposure increased. Non-smokers had higher lung volumes compared to smokers and ex-smokers. Restrictive, obstructive and combined types of impairments were noticed in 28.4%, 1.7% and 2.9%, respectively, workers. The restrictive impairment was found to be 30.4% in conductors; 28.9% in drivers, 27.9% in mechanics and 21.7% in administration people. Obstructive type of impairment was found to be 2.9% in both drivers and conductors. The effect of pollution by dust and fumes may be responsible for these pulmonary function impairments, restrictive impairments being greater.

Alcohol consumption and cardiorespiratory fitness in five population-based studies.

PubMed

Baumeister, Sebastian E; Finger, Jonas D; Gläser, Sven; Dörr, Marcus; Markus, Marcello Rp; Ewert, Ralf; Felix, Stephan B; Grabe, Hans-Jörgen; Bahls, Martin; Mensink, Gert Bm; Völzke, Henry; Piontek, Katharina; Leitzmann, Michael F

2018-01-01

Background Poor cardiorespiratory fitness is a risk factor for cardiovascular morbidity. Alcohol consumption contributes substantially to the burden of disease, but its association with cardiorespiratory fitness is not well described. We examined associations between average alcohol consumption, heavy episodic drinking and cardiorespiratory fitness. Design The design of this study was as a cross-sectional population-based random sample. Methods We analysed data from five independent population-based studies (Study of Health in Pomerania (2008-2012); German Health Interview and Examination Survey (2008-2011); US National Health and Nutrition Examination Survey (NHANES) 1999-2000; NHANES 2001-2002; NHANES 2003-2004) including 7358 men and women aged 20-85 years, free of lung disease or asthma. Cardiorespiratory fitness, quantified by peak oxygen uptake, was assessed using exercise testing. Information regarding average alcohol consumption (ethanol in grams per day (g/d)) and heavy episodic drinking (5+ or 6+ drinks/occasion) was obtained from self-reports. Fractional polynomial regression models were used to determine the best-fitting dose-response relationship. Results Average alcohol consumption displayed an inverted U-type relation with peak oxygen uptake ( p-value<0.0001), after adjustment for age, sex, education, smoking and physical activity. Compared to individuals consuming 10 g/d (moderate consumption), current abstainers and individuals consuming 50 and 60 g/d had significantly lower peak oxygen uptake values (ml/kg/min) (β coefficients = -1.90, β = -0.06, β = -0.31, respectively). Heavy episodic drinking was not associated with peak oxygen uptake. Conclusions Across multiple adult population-based samples, moderate drinkers displayed better fitness than current abstainers and individuals with higher average alcohol consumption.

Respiratory trace feature analysis for the prediction of respiratory-gated PET quantification.

PubMed

Wang, Shouyi; Bowen, Stephen R; Chaovalitwongse, W Art; Sandison, George A; Grabowski, Thomas J; Kinahan, Paul E

2014-02-21

The benefits of respiratory gating in quantitative PET/CT vary tremendously between individual patients. Respiratory pattern is among many patient-specific characteristics that are thought to play an important role in gating-induced imaging improvements. However, the quantitative relationship between patient-specific characteristics of respiratory pattern and improvements in quantitative accuracy from respiratory-gated PET/CT has not been well established. If such a relationship could be estimated, then patient-specific respiratory patterns could be used to prospectively select appropriate motion compensation during image acquisition on a per-patient basis. This study was undertaken to develop a novel statistical model that predicts quantitative changes in PET/CT imaging due to respiratory gating. Free-breathing static FDG-PET images without gating and respiratory-gated FDG-PET images were collected from 22 lung and liver cancer patients on a PET/CT scanner. PET imaging quality was quantified with peak standardized uptake value (SUV(peak)) over lesions of interest. Relative differences in SUV(peak) between static and gated PET images were calculated to indicate quantitative imaging changes due to gating. A comprehensive multidimensional extraction of the morphological and statistical characteristics of respiratory patterns was conducted, resulting in 16 features that characterize representative patterns of a single respiratory trace. The six most informative features were subsequently extracted using a stepwise feature selection approach. The multiple-regression model was trained and tested based on a leave-one-subject-out cross-validation. The predicted quantitative improvements in PET imaging achieved an accuracy higher than 90% using a criterion with a dynamic error-tolerance range for SUV(peak) values. The results of this study suggest that our prediction framework could be applied to determine which patients would likely benefit from respiratory motion compensation when clinicians quantitatively assess PET/CT for therapy target definition and response assessment.

Effect of pH on the structural, optical and morphological properties of Ga-doped ZnO nanoparticles by reflux precipitation method

NASA Astrophysics Data System (ADS)

Ungula, J.; Dejene, B. F.; Swart, H. C.

2018-04-01

Gallium-doped zinc oxide nanoparticles (GZO NPs) were synthesized by the reflux precipitation method at 1, 3, 5, 7 and 8 pH conditions of Ga/Zn precursor solution (Ga/Zn sol.). Analysis of X-ray diffraction (XRD) spectra showed that the diffraction peak intensities of GZO NPs increased and the crystallite sizes varied from 11 to 27 nm with an increase in the pH of the Zn/Ga sol. Scanning electron microscopy micrographs showed agglomerated tiny particles that formed on big slabs of nanorods at the lower pH, but fine and enlarged particles on nano-spherical bases formed at the higher pH values. The photoluminescence exciton peak intensities of the GZO NPs and their respective FWHM increased to a maximum at the 5 pH and then reduced slightly as the solution got more basic. The increase of the deep level peak intensities with the increase in the pH followed the XRD diffraction intensity results. It was observed that both the exciton and DLE peaks emission positions shifted to lower wavelengths up to the 5 pH and then red shifted for a further increase in the pH values. The UV-vis analysis also demonstrated that the optical properties of the GZO NPs improved with the increase Ga/Zn sol. pH, as shown by the blue shift of the absorption edge of the reflectance spectra. The band gap energy was tuned from 3.18 to 3.31 eV with the increase in the pH from 1 to 5. An additional increase in the pH yielded no significant change in the optical properties of the GZO NPs.

Assessment of the use of LED phototherapy on bone defects grafted with hydroxyapatite on rats with iron-deficiency anemia and nonanemic: a Raman spectroscopy analysis.

PubMed

de Castro, Isabele Cardoso Vieira; Rosa, Cristiane Becher; Dos Reis Júnior, João Alves; Moreira, Luiz Gaudêncio Passos; Aragão, Juliana S; Barbosa, Artur Felipe dos Santos; Silveira, Landulfo; Pinheiro, Antonio L B

2014-09-01

This study aimed to assess bone repair in defects grafted or not with hydroxyapatite (HA) on healthy and iron-deficiency anemia (IDA) rats submitted or not to LED phototherapy (LED-PT) by Raman spectroscopy. The animals were divided in eight groups with five rats each: Clot; Clot + LED; IDA + Clot; IDA + LED; Graft; Graft + LED; IDA + Graft; and IDA + Graft + LED. When appropriated, irradiation with IR LED (λ850 ± 10 nm, 150 mW, CW, Φ = 0.5 cm(2), 16 J/cm(2), 15 days) was carried out. Raman shifts: ∼ 960 [symmetric PO4 stretching (phosphate apatite)], ∼ 1,070 [symmetric CO3 stretching (B-type carbonate apatite)], and ∼ 1,454 cm(-1) [CH2/CH3 bending in organics (protein)] were analyzed. The mean peak values for ∼ 960, ∼ 1,070, and ∼ 1,454 cm(-1) were nonsignificantly different on healthy or anemic rats. The group IDA + Graft + LED showed the lowest mean values for the peak ∼ 960 cm(-1) when compared with the irradiated IDA group or not (p ≤ 0.001; p ≤ 0.001). The association of LED-PT and HA-graft showed lowest mean peak at ∼ 1,454 cm(-1) for the IDA rats. The results of this study indicated higher HA peaks as well as a decrease in the level of organic components on healthy animals when graft and LED phototherapy are associated. In the other hand, IDA condition interfered in the graft incorporation to the bone as LED phototherapy only improved bone repair when graft was not used.

Coexistence of charge order and antiferromagnetism in (TMTTF)2SbF6: NMR study

NASA Astrophysics Data System (ADS)

Nomura, K.; Yamamoto, M.; Matsunaga, N.; Hirose, S.; Shimohara, N.; Satoh, T.; Isome, T.; Liu, Y.; Kawamoto, A.

2015-03-01

The electronic state of (TMTTF)2SbF6 was investigated by the 1H and 13C NMR measurements. The temperature dependence of T1-1 in 1H NMR shows a sharp peak associated with the antiferromagnetic transition at TAF=6 K. The temperature dependence of T1-1 is described by the power law T2.4 below TAF. This suggests the nodal gapless spin wave excitation in antiferromagnetic phase. In 13C NMR, two sharp peaks at high temperature region, associated with the inner and the outer carbon sites in TMTTF dimer, split into four peaks below 150 K. It indicates that the charge disproportionation occurs. The degree of charge disproportionation Δρ is estimated as (0.25±0.09)e from the chemical shift difference. This value of Δρ is consistent with that obtained from the infrared spectroscopy. In the antiferromagnetic state (AFI), the observed line shape is well fitted by eight Lorentzian peaks. This suggests that the charge order with the same degree still remains in the AF state. From the line assignment, the AF staggered spin amplitude is obtained as 0.70 μB and 0.24 μB at the charge rich and the poor sites, respectively. These values corresponding to almost 1 μB per dimer are quite different from 0.11 μB of another AF (AFII) state in (TMTTF)2Br with effective higher pressure. As a result, it is understood that the antiferromagnetic staggered spin order is stabilized on the CO state in the AFI phase of (TMTTF)2SbF6.

Detection of Early Right Ventricular Dysfunction in Young Patients With Thalassemia Major Using Tissue Doppler Imaging

PubMed Central

Bornaun, Helen; Dedeoglu, Reyhan; Oztarhan, Kazim; Dedeoglu, Savas; Erfidan, Erkan; Gundogdu, Muge; Aydogan, Gonul; Cengiz, Dicle

2016-01-01

Background Myocardial iron overload is the most common cause of mortality in patients with thalassemia major (TM), also known as beta-thalassemia. T2* cardiovascular magnetic resonance imaging (MRI) is the best way of monitoring cardiac iron, and new echocardiographic techniques can be used to assess cardiac function. Objectives The aim of this study was to assess the systolic and diastolic right ventricular (RV) function of patients with TM using tissue Doppler imaging (TDI) and to determine whether this echocardiographic technique is an adequate diagnostic tool for the screening and detection of subclinical cardiac dysfunction. Patients and Methods Eighty-four patients with TM were evaluated by conventional echocardiography and pulse-wave TDI. The data of the TM group (Group 1) were compared with that of 85 age- and sex-matched healthy controls (Group 2). Cardiovascular T2* MRI examinations were performed in 49 of the 85 patients. Results The patients with TM had significantly lower values for weight, height, body mass index, systolic arterial pressure, deceleration time, E’/A’, and ejection time (ET) than the controls. Group 1 also had significantly higher values for peak early diastolic velocity (E) over peak late diastolic velocity (A), peak early diastolic velocity of TDI (E’), peak late diastolic velocity of TDI (A’), E/E’, isovolumetric relaxation time, isovolumetric contraction time, and RV magnetic perfusion imaging (MPI) than Group 2. Conclusions RV diastolic dysfunction occurs before systolic deterioration in patients with TM and cannot be screened with conventional echocardiographic techniques. In routine practice, TDI measurements, MPI (for global function) and the E/E’ parameter (for diastolic function) can be used to screen and detect early RV dysfunction. PMID:27617076

Comparison of inflammatory responses to a soccer match between elite male and female players.

PubMed

Souglis, Athanasios G; Papapanagiotou, Angeliki; Bogdanis, Gregory C; Travlos, Antonis K; Apostolidis, Nikolaos G; Geladas, Nikolaos D

2015-05-01

The aim of this study was to compare the inflammatory responses between male and female soccer players for a period of 48 hours after an official match. Blood samples were taken from 83 subjects (22 elite male and 21 elite female soccer players and 20 male and 20 female inactive individuals) in the morning of the game day, immediately after the soccer game and 24 and 48 hours after the match. Average relative exercise intensity during the match was similar in male and female players, as indicated by mean heart rate that was 86.9 ± 4.3 and 85.6 ± 2.3% of maximal heart rate (p = 0.23), respectively. Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) increased 2- to 4-fold above resting values, peaking immediately after the match. C-reactive protein (CRP) and creatine kinase peaked 24 hours after the match. Interleukin 6, CRP, and creatine kinase responses were similar in male and female players, but the peak in TNF-α was 18% higher in male players. Interleukin 6, TNF-α, and CRP at rest were lower in male and female players compared with the control subjects, suggesting a protective effect of regular exercise training regarding the inflammatory profile. The results of this study show that a soccer match induces significant inflammatory responses in both male and female players, with only TNF-α peak values being lower in females. Because of the effects of inflammatory responses on performance and health of the players, it is suggested that coaches and trainers should adjust exercise training programs after a match to promote recovery and protect the athletes' health.

Venus: mass, gravity field, atmosphere, and ionosphere as measured by the mariner 10 dual-frequency radio system.

PubMed

Howard, H T; Tyler, G L; Fjeldbo, G; Kliore, A J; Levy, G S; Brunn, D L; Dickinson, R; Edelson, R E; Martin, W L; Postal, R B; Seidel, B; Sesplaukis, T T; Shirley, D L; Stelzried, C T; Sweetnam, D N; Zygielbaum, A I; Esposito, P B; Anderson, J D; Shapiro, I I; Reasenberg, R D

1974-03-29

Analysis of the Doppler tracking data near encounter yields a value for the ratio of the mass of the sun to that of Venus of 408,523.9 +/- 1.2, which is in good agreement with prior determinations based on data from Mariner 2 and Mariner 5. Preliminary analysis indicates that the magnitudes of the fractional differences in the principal moments of inertia of Venus are no larger than 10(-4), given that the effects of gravity-field harmonics higher than the second are negligible. Additional analysis is needed to determine the influence of the higher order harmonics on this bound. Four distinct temperature inversions exist at altitudes of 56, 58, 61, and 63 kilometers. The X-band signal was much more rapidly attenuated than the S-band signal and disappeared completely at 52-kilometer altitude. The nightside ionosphere consists of two layers having a peak density of 10(4) electrons per cubic centimeter at altitudes of 140 and 120 kilometers. The dayside ionosphere has a peak density of 3 X 10(5) electrons per cubic centimeter at an altitude of 145 kilometers. The electron number density observed at higher altitudes was ten times less than that observed by Mariner 5, and no strong evidence for a well-defined plasmapause was found.

FDTD calculations of specific energy absorption rate in a seated voxel model of the human body from 10 MHz to 3 GHz

NASA Astrophysics Data System (ADS)

Findlay, R. P.; Dimbylow, P. J.

2006-05-01

Finite-difference time-domain (FDTD) calculations have been performed to investigate the frequency dependence of the specific energy absorption rate (SAR) in a seated voxel model of the human body. The seated model was derived from NORMAN (NORmalized MAN), an anatomically realistic voxel phantom in the standing posture with arms to the side. Exposure conditions included both vertically and horizontally polarized plane wave electric fields between 10 MHz and 3 GHz. The resolution of the voxel model was 4 mm for frequencies up to 360 MHz and 2 mm for calculations in the higher frequency range. The reduction in voxel size permitted the calculation of SAR at these higher frequencies using the FDTD method. SAR values have been calculated for the seated adult phantom and scaled versions representing 10-, 5- and 1-year-old children under isolated and grounded conditions. These scaled models do not exactly reproduce the dimensions and anatomy of children, but represent good geometric information for a seated child. Results show that, when the field is vertically polarized, the sitting position causes a second, smaller resonance condition not seen in resonance curves for the phantom in the standing posture. This occurs at ~130 MHz for the adult model when grounded. Partial-body SAR calculations indicate that the upper and lower regions of the body have their own resonant frequency at ~120 MHz and ~160 MHz, respectively, when the grounded adult model is orientated in the sitting position. These combine to produce this second resonance peak in the whole-body averaged SAR values calculated. Two resonance peaks also occur for the sitting posture when the incident electric field is horizontally polarized. For the adult model, the peaks in the whole-body averaged SAR occur at ~180 and ~600 MHz. These peaks are due to resonance in the arms and feet, respectively. Layer absorption plots and colour images of SAR in individual voxels show the specific regions in which the seated human body absorbs the incident field. External electric field values required to produce the ICNIRP basic restrictions were derived from SAR calculations and compared with ICNIRP reference levels. This comparison shows that the reference levels provide a conservative estimate of the ICNIRP whole-body averaged SAR restriction, with the exception of the region above 1.4 GHz for the scaled 1-year-old model.

FDTD calculations of specific energy absorption rate in a seated voxel model of the human body from 10 MHz to 3 GHz.

PubMed

Findlay, R P; Dimbylow, P J

2006-05-07

Finite-difference time-domain (FDTD) calculations have been performed to investigate the frequency dependence of the specific energy absorption rate (SAR) in a seated voxel model of the human body. The seated model was derived from NORMAN (NORmalized MAN), an anatomically realistic voxel phantom in the standing posture with arms to the side. Exposure conditions included both vertically and horizontally polarized plane wave electric fields between 10 MHz and 3 GHz. The resolution of the voxel model was 4 mm for frequencies up to 360 MHz and 2 mm for calculations in the higher frequency range. The reduction in voxel size permitted the calculation of SAR at these higher frequencies using the FDTD method. SAR values have been calculated for the seated adult phantom and scaled versions representing 10-, 5- and 1-year-old children under isolated and grounded conditions. These scaled models do not exactly reproduce the dimensions and anatomy of children, but represent good geometric information for a seated child. Results show that, when the field is vertically polarized, the sitting position causes a second, smaller resonance condition not seen in resonance curves for the phantom in the standing posture. This occurs at approximately 130 MHz for the adult model when grounded. Partial-body SAR calculations indicate that the upper and lower regions of the body have their own resonant frequency at approximately 120 MHz and approximately 160 MHz, respectively, when the grounded adult model is orientated in the sitting position. These combine to produce this second resonance peak in the whole-body averaged SAR values calculated. Two resonance peaks also occur for the sitting posture when the incident electric field is horizontally polarized. For the adult model, the peaks in the whole-body averaged SAR occur at approximately 180 and approximately 600 MHz. These peaks are due to resonance in the arms and feet, respectively. Layer absorption plots and colour images of SAR in individual voxels show the specific regions in which the seated human body absorbs the incident field. External electric field values required to produce the ICNIRP basic restrictions were derived from SAR calculations and compared with ICNIRP reference levels. This comparison shows that the reference levels provide a conservative estimate of the ICNIRP whole-body averaged SAR restriction, with the exception of the region above 1.4 GHz for the scaled 1-year-old model.

Predictive Value of Dental Maturity for a Positive Gonadotropin-Releasing Hormone Stimulation Test Result in Girls with Precocious Puberty

PubMed Central

2017-01-01

Dental maturity is associated with skeletal maturity, which is advanced in girls with central precocious puberty (CPP). We investigated the performance of dental maturity as a screening method for CPP using mandibular second premolar and molar calcification stages, assessed the associated anthropometric and laboratory factors, and evaluated pubertal response predictors using the gonadotropin-releasing hormone stimulation test (GnRHST) in prepubertal and pubertal girls. A prospective case-control study was conducted in girls, aged 7.0–8.9 years, classified into pubertal (peak luteinizing hormone [LH] after GnRHST ≥ 5 IU/L), prepubertal (peak LH < 5 IU/L), and control groups. Auxological and biochemical tests, panoramic radiographs, and GnRHSTs in participants with breast development were conducted. Dental maturity was assessed using the Demirjian index (DI). We included 103 girls (pubertal, 40; prepubertal, 19; control, 44). Chronological age (CA) was not significantly different between groups. Bone age (BA) and BA advancement was higher in the pubertal and prepubertal groups. Increased DI values at the mandibular second premolar and molar were significantly associated with CA, BA, BA advancement, height standard deviation score (SDS), peak LH after GnRHST, and insulin-like growth factor-I (IGF-I) (all P < 0.05). Moreover, odds ratio (OR) of the mandibular second premolar and molar (a DI value of ≥ E) for predicting a positive response to GnRHST was 8.7 (95% confidence intervals [CI], 2.9–26.1) and 5.2 (95% CI, 2.2–12.7), respectively. Dental maturity was a strong predictor for diagnosing CPP. Determining dental maturity in girls with suspected precocious puberty might help determine the performance of GnRHSTs. PMID:28049241

Predictive Value of Dental Maturity for a Positive Gonadotropin-Releasing Hormone Stimulation Test Result in Girls with Precocious Puberty.

PubMed

Baik, Jee Seon; Choi, Jin Woo; Kim, Su Jin; Kim, Ji Hyun; Kim, Sollip; Kim, Jae Hyun

2017-02-01

Dental maturity is associated with skeletal maturity, which is advanced in girls with central precocious puberty (CPP). We investigated the performance of dental maturity as a screening method for CPP using mandibular second premolar and molar calcification stages, assessed the associated anthropometric and laboratory factors, and evaluated pubertal response predictors using the gonadotropin-releasing hormone stimulation test (GnRHST) in prepubertal and pubertal girls. A prospective case-control study was conducted in girls, aged 7.0-8.9 years, classified into pubertal (peak luteinizing hormone [LH] after GnRHST ≥ 5 IU/L), prepubertal (peak LH < 5 IU/L), and control groups. Auxological and biochemical tests, panoramic radiographs, and GnRHSTs in participants with breast development were conducted. Dental maturity was assessed using the Demirjian index (DI). We included 103 girls (pubertal, 40; prepubertal, 19; control, 44). Chronological age (CA) was not significantly different between groups. Bone age (BA) and BA advancement was higher in the pubertal and prepubertal groups. Increased DI values at the mandibular second premolar and molar were significantly associated with CA, BA, BA advancement, height standard deviation score (SDS), peak LH after GnRHST, and insulin-like growth factor-I (IGF-I) (all P < 0.05). Moreover, odds ratio (OR) of the mandibular second premolar and molar (a DI value of ≥ E) for predicting a positive response to GnRHST was 8.7 (95% confidence intervals [CI], 2.9-26.1) and 5.2 (95% CI, 2.2-12.7), respectively. Dental maturity was a strong predictor for diagnosing CPP. Determining dental maturity in girls with suspected precocious puberty might help determine the performance of GnRHSTs.

The relationship between heart rate recovery and brain natruretic Peptide in patients with chest discomfort: a study for relationship between heart rate recovery and pre-exercise, post-exercise levels of brain natruretic Peptide in patients with normal systolic function and chest discomfort.

PubMed

Lee, Jae Eun; Kim, Bum Soo; Park, Wan; Huh, Jung Kwon; Kim, Byung Jin; Sung, Ki Chul; Kang, Jin Ho; Lee, Man Ho; Park, Jung Ro

2010-04-01

The correlation between brain natruretic peptide (BNP) level and cardiac autonomic function has been studied in type 2 diabetic patients. However, there is limited data from patients with normal systolic function. We evaluated the association between heart rate recovery (HRR) representing autonomic dysfunction and three plasma BNP levels: pre-exercise, post-exercise, and change during exercise in patients with normal systolic function. Subjects included 105 patients with chest pain and normal systolic function. HRR was defined as the difference between the peak heart rate and the rate measured two minutes after completion of a treadmill exercise test. We measured plasma BNP levels before exercise, 5 minutes after completion of exercise, and during exercise (absolute value of difference between pre- and post-exercise BNP levels). Patients with abnormal HRR values (

The effects of co-administration of benzhexol on the peripheral pharmacokinetics of oral levodopa in young volunteers

PubMed Central

ROBERTS, J.; WALLER, D. G.; RENWICK, A. G.; O'SHEA, N.; MACKLIN, B. S.; BULLING, M.

1996-01-01

1 The effects of benzhexol on the absorption and pharmacokinetics of an oral dose of levodopa have been studied in 10 young healthy volunteers. Subjects were given a suspension of levodopa (250 mg) 90 min after either benzhexol (5 mg) or placebo in a randomized cross over design with doses separated by at least 1 week; on each occasion carbidopa was given 1 h before and 5 h after the dose of levodopa. Soluble paracetamol and radiolabelled DTPA were given with the levodopa as markers of gastric emptying. 2 Most subjects showed two peaks in the levodopa plasma concentration–time curve on the placebo day, with the second minor peak occurring 1–2 h after the dose. After benzhexol administration all subjects showed two or more peak levodopa concentrations in plasma. Benzhexol administration caused a significant decrease in the maximum concentration (43%; P<0.05) of the initial peak and an increase (22%; P<0.1) in the maximum concentration of the second peak. This change in absorption profile caused by benzhexol significantly altered the ratios of the second peak compared with the initial peak for both the maximum concentrations (P<0.02) and for the AUC values (P<0.05). Benzhexol administration did not affect the total AUC of levodopa (7.30±1.09 vs 7.19±1.26 μg ml−1 h; means±s.d.). 3 The plasma concentration–time curves for paracetamol showed similar profiles to those for levodopa and the ratios of the peak concentrations and AUC values for the second peak compared with the initial peak were increased significantly by benzhexol administration (P<0.05). The total AUC of paracetamol was not affected by benzhexol administration (39.4±8.2 vs 40.0±8.9 μg ml−1 h; mean±s.d.) 4 Benzhexol altered the gastric emptying profile, shown by γ-scintigraphy, with a reduced extent of initial emptying prior to the establishment of the plateau which is characteristic of levodopa administration in the fasting state. In consequence the ratio of the second to the initial phase of emptying was significantly higher (P<0.01) following benzhexol treatment. 5 Benzhexol reduces the initial phase of gastric emptying after a dose of levodopa so that there is a decrease in the initial peak and a greater proportion of the dose is absorbed subsequently following the second phase of gastric emptying which occurs approximately 1 h later. Theoretically, this altered concentration-time profile could be an advantage for some patients with Parkinson's disease. PMID:8730980

PFReports: A program for systematic checking of annual peaks in NWISWeb

USGS Publications Warehouse

Ryberg, Karen R.

2008-01-01

The accuracy, characterization, and completeness of the U.S. Geological Survey (USGS) peak-flow data drive the determination of flood-frequency estimates that are used daily to design water and transportation infrastructure, delineate flood-plain boundaries, and regulate development and utilization of lands throughout the Nation and are essential to understanding the implications of climate change on flooding. Indeed, this high-profile database reflects and highlights the quality of USGS water-data collection programs. Its extension and improvement are essential to efforts to strengthen USGS networks and science leadership and is worthy of the attention of Water Science Center (WSC) hydrographers. This document describes a computer program, PFReports, and its output that facilitates efficient and robust review and correction of data in the USGS Peak Flow File (PFF) hosted as part of NWISWeb (the USGS public Web interface to much of the data stored and managed within the National Water Information System or NWIS). Checks embedded in the program are recommended as part of a more comprehensive assessment of peak flow data that will eventually include examination of possible regional changes, seasonal changes, and decadal variations in magnitude, timing, and frequency. Just as important as the comprehensive assessment, cleaning up the database will increase the likelihood of improved WSC regional flood-frequency equations. As an example of the value of cleaning up the PFF, data for 26,921 sites in the PFF were obtained. Of those sites, 17,542 sites had peak streamflow values and daily values. For the 17,542 sites, 1,097 peaks were identified that were less than the daily value for the day on which the peak occurred. Of the 26,921 sites, 11,643 had peak streamflow values, concurrent daily values, and at least 10 peaks. At the 11,643 sites, 2,205 peaks were identified as potential outliers in a regression of peak streamflows on daily values. Previous efforts to identify problems with the PFF were time consuming, laborious, and often ineffective. This new suite of checks represents an effort to automate identification of specific problems without plotting or printing large amounts of data that may not have problems. In addition, the results of the checks of the peak flow files are delivered through the World Wide Web with links to individual reports so that WSCs can focus on specific problems in an organized and standardized fashion. Over the years, technical reviews, regional-flood studies, and user inquiries have identified many minor and some major problems in the PFF. However, the cumbersome nature of the PFF editor and a lack of analytical tools have hampered efforts at quality assurance/quality control (QA/QC) and subsequently to make needed revisions to the database. This document is organized to provide information regarding PFReports, especially those tests involving regression and to provide an overview of the review procedures for utilizing the output. It also may be used as a reference for the data qualification codes and abbreviations for the tests. Results of the checks for all peak flow files (March 2008) are available at http://nd.water.usgs.gov/internal/pfreports/.

Historical changes in annual peak flows in Maine and implications for flood-frequency analyses

USGS Publications Warehouse

Hodgkins, Glenn A.

2010-01-01

Flood-frequency analyses use statistical methods to compute peak streamflows for selected recurrence intervals— the average number of years between peak flows that are equal to or greater than a specified peak flow. Analyses are based on annual peak flows at a stream. It has long been assumed that the annual peak streamflows used in these computations were stationary (non-changing) over very long periods of time, except in river basins subject to direct effects of human activities, such as urbanization and regulation. Because of the potential effects of global warming on peak flows, the assumption of peak-flow stationarity has recently been questioned. Maine has many streamgages with 50 to 105 years of recorded annual peak streamflows. In this study, this long-term record has been tested for historical flood-frequency stationarity, to provide some insight into future flood frequency. Changes over time in annual instantaneous peak streamflows at 28 U.S. Geological Survey streamgages with long-term data (50 or more years) and relatively complete records were investigated by examining linear trends for each streamgage’s period of record. None of the 28 streamgages had more than 5 years of missing data. Eight streamgages have substantial streamflow regulation. Because previous studies have suggested that changes over time may have occurred as a step change around 1970, step changes between each streamgage’s older record (start year to 1970) and newer record (1971 to 2006) also were computed. The median change over time for all 28 streamgages is an increase of 15.9 percent based on a linear change and an increase of 12.4 percent based on a step change. The median change for the 20 unregulated streamgages is slightly higher than for all 28 streamgages; it is 18.4 percent based on a linear change and 15.0 percent based on a step change. Peak flows with 100- and 5-year recurrence intervals were computed for the 28 streamgages using the full annual peak-flow record and multiple sub-periods of that record using the guidelines (Bulletin 17B) of the Interagency Advisory Committee on Water Data. Magnitudes of 100- and 5-year peak flows computed from sub-periods then were compared to those computed from the full period. Sub-periods of 30 years with starting years staggered by 10 years were evaluated (1907–36, 1917–46, 1927–56, 1937–66, 1947–76, 1957–86, 1967–96, and 1977–2006). Two other sub-periods were evaluated using older data (start-of-record to 1970) and newer data (1971 to 2006). The 5-year peak flow is used to represent small and relatively frequent flood flows in Maine, whereas the 100-year peak flow is used to represent large flood flows. The 1967–96 sub-period generated the highest 100- and 5-year peak flows overall when compared to peak flows based on the full period of record; the median difference for all 28 streamgages is 8 percent for 100- and 5-year peak flows. The 1977–2006 and 1971–2006 sub-periods also generated 100- and 5-year peak flows higher than peak flows based on the full period of record, but not as high as the peak flows based on the 1967–96 sub-period. The 1937–66 sub-period generated the lowest 100- and 5-year peak flows overall. The median difference from full-period peak flows is -11 percent for 100-year peak flows and -8 percent for 5-year peak flows. Overall, differences between peak flows based on the sub-periods and those based on the full periods, generated using the 20 unregulated streamgages, are similar to differences using all 28 streamgages. Increases in the 5- and 100-year peak flows based on recent years of record are, in general, modest when compared to peak flows based on complete periods of record. The highest peak flows are based on the 1967–96 sub-period rather than the most recent sub-period (1977-2006). Peak flows for selected recurrence intervals are sensitive to very high peak flows that may occur once in a century or even less frequently. It is difficult, therefore, to determine which approach will produce the most reliable future estimates of peak flows for selected recurrence intervals, using only recent years of record or the traditional method using the entire historical period. One possible conservative approach to computing peak flows of selected recurrence intervals would be to compute peak flows using recent annual peak flows and the entire period of record, then choose the higher computed value. Whether recent or entire periods of record are used to compute peak flows of selected recurrence intervals, the results of this study highlight the importance of using recent data in the computation of the peak flows. The use of older records alone could result in underestimation of peak flows, particularly peak flows with short recurrence intervals, such as the 5-year peak flows.

Influence of fiber bending on wavelength demodulation of fiber-optic Fabry-Perot interferometric sensors.

PubMed

Liu, Guigen; Sheng, Qiwen; Hou, Weilin; Han, Ming

2016-11-14

In practical applications of fiber optic sensors based on Fabry-Perot interferometers (FPIs), the lead-in optical fiber often experiences dynamic or static bending due to environmental perturbations or limited installation space. Bending introduces wavelength-dependent losses to the sensors, which can cause erroneous readings for sensors based on wavelength demodulation interrogation. Here, we investigate the bending-induced wavelength shift (BIWS) to sensors based on FPIs. Partially explicit expressions of BIWSs for the reflection fringe peaks and valleys have been derived for sensors based on low-finesse FPI. The theoretical model predicts these findings: 1) provided that a fringe peak experiences the same modulation slope by bending losses with a fringe valley, BIWSs for the peak and valley have opposite signs and the BIWS for the valley has a smaller absolute value; 2) BIWS is a linear function of the length of the bending section; 3) a FPI with higher visibility and longer optical path length is more resistant to the influence of bending. Experiments have been carried out and the results agree well with the theoretical predictions.

Inhibition of coronary blood flow by a vascular waterfall mechanism.

PubMed

Downey, J M; Kirk, E S

1975-06-01

The mechanism whereby systole inhibits coronary blood flow was examined. A branch of the left coronary artery was maximally dilated with an adenosine infusion, and the pressure-flow relationship was obtained for beating and arrested states. The pressure-flow curve for the arrested state was shifted toward higher pressures and in the range of pressures above peak ventricular pressure was linear and parallel to that for the arrested state. Below this range the curve for the beating state converged toward that for the arrested state and was convex to the pressure axis. These results were compared with a model of the coronary vasculature that consisted of numerous parallel channels, each responding to local intramyocardial pressure by forming vascular waterfalls. When intramyocardial pressure in the model was assigned values from zero at the epicardium to peak ventricular pressure at the endocardium, pressure-flow curves similar to the experimental ones resulted. Thus, we conclude that systole inhibits coronary perfusion by the formation of vascular waterfalls and that the intramyocardial pressures responsible for this inhibition do not significantly exceed peak ventricular pressure.

Turbulent convective heat transfer of methane at supercritical pressure in a helical coiled tube

NASA Astrophysics Data System (ADS)

Wang, Chenggang; Sun, Baokun; Lin, Wei; He, Fan; You, Yingqiang; Yu, Jiuyang

2018-02-01

The heat transfer of methane at supercritical pressure in a helically coiled tube was numerically investigated using the Reynolds Stress Model under constant wall temperature. The effects of mass flux ( G), inlet pressure ( P in) and buoyancy force on the heat transfer behaviors were discussed in detail. Results show that the light fluid with higher temperature appears near the inner wall of the helically coiled tube. When the bulk temperature is less than or approach to the pseudocritical temperature ( T pc ), the combined effects of buoyancy force and centrifugal force make heavy fluid with lower temperature appear near the outer-right of the helically coiled tube. Beyond the T pc , the heavy fluid with lower temperature moves from the outer-right region to the outer region owing to the centrifugal force. The buoyancy force caused by density variation, which can be characterized by Gr/ Re 2 and Gr/ Re 2.7, enhances the heat transfer coefficient ( h) when the bulk temperature is less than or near the T pc , and the h experiences oscillation due to the buoyancy force. The oscillation is reduced progressively with the increase of G. Moreover, h reaches its peak value near the T pc . Higher G could improve the heat transfer performance in the whole temperature range. The peak value of h depends on P in. A new correlation was proposed for methane at supercritical pressure convective heat transfer in the helical tube, which shows a good agreement with the present simulated results.

Adjusting annual maximum peak discharges at selected stations in northeastern Illinois for changes in land-use conditions

USGS Publications Warehouse

Over, Thomas M.; Saito, Riki J.; Soong, David T.

2016-06-30

The observed and adjusted values for each streamgage are tabulated. To illustrate the overall effect of the adjustments, differences in the mean, standard deviation, and skewness of the log-transformed observed and urbanization-adjusted peak discharge series by streamgage are computed. For almost every streamgage where an adjustment was applied (no increase in urbanization was reported for a few streamgages), the mean increased and the standard deviation decreased; the effect on skewness values was more variable but usually they increased. Significant positive peak discharge trends were common in the observed values, occurring at 27.3 percent of streamgages at a p-value of 0.05 according to a Kendall’s tau correlation test; in the adjusted values, the incidence of such trends was reduced to 7.0 percent.

Utility of Equations to Estimate Peak Oxygen Uptake and Work Rate From a 6-Minute Walk Test in Patients With COPD in a Clinical Setting.

PubMed

Kirkham, Amy A; Pauhl, Katherine E; Elliott, Robyn M; Scott, Jen A; Doria, Silvana C; Davidson, Hanan K; Neil-Sztramko, Sarah E; Campbell, Kristin L; Camp, Pat G

2015-01-01

To determine the utility of equations that use the 6-minute walk test (6MWT) results to estimate peak oxygen uptake ((Equation is included in full-text article.)o2) and peak work rate with chronic obstructive pulmonary disease (COPD) patients in a clinical setting. This study included a systematic review to identify published equations estimating peak (Equation is included in full-text article.)o2 and peak work rate in watts in COPD patients and a retrospective chart review of data from a hospital-based pulmonary rehabilitation program. The following variables were abstracted from the records of 42 consecutively enrolled COPD patients: measured peak (Equation is included in full-text article.)o2 and peak work rate achieved during a cycle ergometer cardiopulmonary exercise test, 6MWT distance, age, sex, weight, height, forced expiratory volume in 1 second, forced vital capacity, and lung diffusion capacity. Estimated peak (Equation is included in full-text article.)o2 and peak work rate were estimated from 6MWT distance using published equations. The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work to prescribe aerobic exercise intensities of 60% and 80% was calculated. Eleven equations from 6 studies were identified. Agreement between estimated and measured values was poor to moderate (intraclass correlation coefficients = 0.11-0.63). The error associated with using estimated peak (Equation is included in full-text article.)o2 or peak work rate to prescribe exercise intensities of 60% and 80% of measured values ranged from mean differences of 12 to 35 and 16 to 47 percentage points, respectively. There is poor to moderate agreement between measured peak (Equation is included in full-text article.)o2 and peak work rate and estimations from equations that use 6MWT distance, and the use of the estimated values for prescription of aerobic exercise intensity would result in large error. Equations estimating peak (Equation is included in full-text article.)o2 and peak work rate are of low utility for prescribing exercise intensity in pulmonary rehabilitation programs.

Cardiopulmonary fitness is strongly associated with body cell mass and fat-free mass: The Study of Health in Pomerania (SHIP).

PubMed

Köhler, A; King, R; Bahls, M; Groß, S; Steveling, A; Gärtner, S; Schipf, S; Gläser, S; Völzke, H; Felix, S B; Markus, M R P; Dörr, M

2018-01-18

Peak oxygen uptake (VO2peak) is commonly indexed by total body weight (TBW) to determine cardiopulmonary fitness (CPF). This approach may lead to misinterpretation, particularly in obese subjects. We investigated the normalization of VO2peak by different body composition markers. We analyzed combined data of 3848 subjects (1914 women; 49.7%), aged 20-90, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-2 and SHIP-TREND). VO2peak was assessed by cardiopulmonary exercise testing. Body cell mass (BCM), fat-free mass (FFM), and fat mass (FM) were determined by bioelectrical impedance analysis. The suitability of the different markers as a normalization variable was evaluated by taking into account correlation coefficients (r) and intercept (α-coefficient) values from linear regression models. A combination of high r and low α values was considered as preferable for normalization purposes. BCM was the best normalization variable for VO2peak (r = .72; P ≤ .001; α-coefficient = 63.3 mL/min; 95% confidence interval [CI]: 3.48-123) followed by FFM (r = .63; P ≤ .001; α-coefficient = 19.6 mL/min; 95% CI: -57.9-97.0). On the other hand, a much weaker correlation and a markedly higher intercept were found for TBW (r = .42; P ≤ .001; α-coefficient = 579 mL/min; 95% CI: 483 to 675). Likewise, FM was also identified as a poor normalization variable (r = .10; P ≤ .001; α-coefficient = 2133; 95% CI: 2074-2191). Sex-stratified analyses confirmed the above order for the different normalization variables. Our results suggest that BCM, followed by FFM, might be the most appropriate marker for the normalization of VO2peak when comparing CPF between subjects with different body shape. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Acemannan-containing wound dressing gel reduces radiation-induced skin reactions in C3H mice

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

Roberts, D.B.; Travis, E.L.

To determine (a) whether a wound dressing gel that contains acemannan extracted from aloe leaves affects the severity of radiation-induced acute skin reactions in C3H mice; (b) if so, whether other commercially available gels such as a personal lubricating jelly and a healing ointment have similar effects; and (c) when the wound dressing gel should be applied for maximum effect. Male C3H mice received graded single doses of gamma radiation ranging from 30 to 47.5 Gy to the right leg. In most experiments, the gel was applied daily beginning immediately after irradiation. Dose-response curves were obtained by plotting the percentagemore » of mice that reached or exceeded a given peak skin reaction as a function of dose. Curves were fitted by logit analysis and ED{sub 50} values, and 95% confidence limits were obtained. The average peak skin reactions of the wound dressing gel-treated mice were lower than those of the untreated mice at all radiation doses tested. The ED{sub 50} values for skin reactions of 2.0-2.75 were approximately 7 Gy higher in the wound dressing gel-treated mice. The average peak skin reactions and the ED{sub 50} values for mice treated with personal lubricating jelly or healing ointment were similar to irradiated control values. Reduction in the percentage of mice with skin reactions of 2.5 or more was greatest in the groups that received wound dressing gel for at least 2 weeks beginning immediately after irradiation. There was no effect if gel was applied only before irradiation or beginning 1 week after irradiation. Wound dressing gel, but not personal lubricating jelly or healing ointment, reduces acute radiation-induced skin reactions in C3H mice if applied daily for at least 2 weeks beginning immediately after irradiation. 31 refs., 4 figs., 1 tab.« less

Atmospheric pCO2 Reconstructed across the Early Eocene Hyperthermals

NASA Astrophysics Data System (ADS)

Cui, Y.; Schubert, B.

2015-12-01

Negative carbon isotope excursions (CIEs) are commonly associated with extreme global warming. The Early Eocene is punctuated by five such CIEs, the Paleocene-Eocene thermal maximum (PETM, ca. 55.8 Ma), H1 (ca. 53.6 Ma), H2 (ca. 53.5 Ma), I1 (ca. 53.3 Ma), and I2 (ca. 53.2 Ma), each characterized by global warming. The negative CIEs are recognized in both marine and terrestrial substrates, but the terrestrial substrates exhibit a larger absolute magnitude CIE than the marine substrates. Here we reconcile the difference in CIE magnitude between the terrestrial and marine substrates for each of these events by accounting for the additional carbon isotope fractionation by C3 land plants in response to increased atmospheric pCO2. Our analysis yields background and peak pCO2 values for each of the events. Assuming a common mechanism for each event, we calculate that background pCO2 was not static across the Early Eocene, with the highest background pCO2 immediately prior to I2, the last of the five CIEs. Background pCO2 is dependent on the source used in our analysis with values ranging from 300 to 720 ppmv provided an injection of 13C-depleted carbon with δ13C value of -60‰ (e.g. biogenic methane). The peak pCO2 during each event scales according to the magnitude of CIE, and is therefore greatest during the PETM and smallest during H2. Both background and peak pCO2 are higher if we assume a mechanism of permafrost thawing (δ13C = -25‰). Our reconstruction of pCO2 across these events is consistent with trends in the δ18O value of deep-sea benthic foraminifera, suggesting a strong link between pCO2 and temperature during the Early Eocene.

Quantitative evaluation of the stretch reflex before and after hydro kinesy therapy in patients affected by spastic paresis.

PubMed

Pagliaro, P; Zamparo, P

1999-04-01

The aim of this study was the quantitative evaluation of the myotatic reflex in a group of 26 patients affected by stationary spastic paresis (6: hemiparesis; 5: paraparesis; 8: tetraparesis; 7: multiple sclerosis) before and after a treatment of hydro-kinesy therapy. The treatment was carried out in an indoor pool containing warm (32 degrees C) sea water and consisted of active and passive motion exercises, coordination exercises and immersion walking. The measured parameters were: (i) the peak input force (FpH) measured by means of an instrumented hammer with which the patellar tendon was hit; and (ii) the peak value of the corresponding reflex force of the quadriceps femoris (FpQ) measured by means of a load cell connected to the subject's ankle. The peak values of the reflex response (FpQ) were found to increase as a function of the intensity of the imposed stimulus and to reach a plateau between 15 and 30 N of FpH. A Student's t test applied to the paired values of FpQ (as measured at plateau conditions) on both the lower limbs, before and after therapy, showed no significant changes due to the treatment in the four groups of subjects. However, if all subjects were grouped regardless the type of illness: 1) the average reflex response of the affected limb (the one characterized before therapy by the higher FpQ values) was found to decrease following the treatment (75.1+/-26.7 N pre therapy and 69.1+/-29.3 N post therapy, p = 0.07, n = 26); and 2) the effect of the treatment was found to be significantly larger (p = 0.04, n = 26) on the affected limb (delta FpQ = 6.07+/-16.5 N) as respect with the contra lateral one (delta FpQ = -0.16+/-12.1 N).

ISOKINETIC KNEE MUSCLE STRENGTH PROFILE IN BRAZILIAN MALE SOCCER, FUTSAL, AND BEACH SOCCER PLAYERS: A CROSS-SECTIONAL STUDY

PubMed Central

Mascarin, Naryana C.; Vargas, Valentine Z.; Vancini, Rodrigo L.; Andrade, Marília S.

2017-01-01

Background Anterior cruciate ligament injury is higher in soccer athletes as compared to athletes of other sports. Risk factors for anterior cruciate ligament injury include low knee hamstring/quadriceps strength ratio and bilateral strength deficits. Purpose To investigate isokinetic thigh muscles strength, hamstring/quadriceps strength ratio, and bilateral strength comparisons in athletes who participate in professional soccer, futsal, and beach soccer. Study Design Cross-sectional study. Methods Brazilian professional soccer (n=70), futsal (n=30), and beach soccer (n=12) players were isokinetically assessed to examine strength of knee extensors and flexors at 60 degrees/second in concentric mode, to measure peak torque of dominant and non-dominant limbs. Results In the dominant limb, for extensors muscles, futsal players presented significantly lower peak torque values (223.9 ± 33.4 Nm) than soccer (250.9 ± 43.0 Nm; p=0.02) and beach soccer players (253.1 ± 32.4 Nm; p=0.03). Peak torque for extensor muscles in the non-dominant limb was significantly lower in futsal (224.0 ± 35.8 Nm) than in beach soccer players (256.8 ± 39.8 Nm; p=0.03). Hamstring/quadriceps strength ratio for dominant limbs for futsal (57.6 ± 10.1%), soccer (53.5 ± 8.8%), and beach soccer (56.3 ± 8.4%) players presented no significant differences between groups; however, the mean values were lower than recommended values found in the literature. There were no strength deficits for any of the evaluated groups when compared bilaterally. Conclusions Futsal athletes presented lower values for quadriceps strength than soccer and beach soccer athletes. Futsal, soccer, and beach soccer players presented no strength asymmetries, but they presented with strength imbalance in hamstring/quadriceps strength ratio. Level of Evidence 3 PMID:29234562

Molecular spectroscopic features of protein in newly developed chickpea: Relationship with protein chemical profile and metabolism in the rumen and intestine of dairy cows

NASA Astrophysics Data System (ADS)

Sun, Baoli; Khan, Nazir Ahmad; Yu, Peiqiang

2018-05-01

The first aim of this study was to investigate the nutritional value of crude protein (CP) in CDC [Crop Development Centre (CDC), University of Saskatchewan] chickpea varieties (Frontier kabuli and Corinne desi) in comparison with a CDC barley variety in terms of: 1) CP chemical profile and subfractions; (2) in situ rumen degradation kinetics and intestinal digestibility of CP; 2) metabolizable protein (MP) supply to dairy cows; and (3) protein molecular structure characteristics using advanced molecular spectroscopy. The second aim was to quantify the relationship between protein molecular spectral characteristics and CP subfractions, in situ rumen CP degradation characteristics, intestinal digestibility of CP, and MP supply to dairy cows. Samples (n = 4) of each variety, from two consecutive years were analyzed. Chickpeas had higher (P < 0.01) CP content (21.71-22.11 vs 12.96% DM), with higher (P < 0.05) soluble CP subfraction (59.07-70.27 vs 26.18% CP), and in situ soluble (23.44-25.85 vs 1.30% CP) and rumen degradable (RDP; 72.23-72.57 vs 58.48% CP) fractions than barley. The potentially slowly rumen degradable (D; 74.14-76.56 vs 93.31% CP) and undegradable (RUP; 27.43-27.66 vs 41.52% CP) fractions were lower (P < 0.01) in the chickpeas than barley. The effective degradability ratio of N to organic matter (OM) (36.07-38.44 g N/kg OM) of the chickpeas was higher than the optimal for achieving optimum microbial CP (MCP) synthesis. The truly digested MCP (64.94-66.43 vs. 41.43 g/kg DM); MP (81.10-83.67 vs 61.0 g/kg DM) feed milk value (1.64-1.70 vs 1.24) was higher in the chickpeas than barley grain. The chickpeas had higher (P < 0.05) amide I and II peaks area and height, and α-helix and β-sheet peaks height than barley. Multivariate analysis showed that protein molecular spectral data of chickpeas can be distinguished from the barley. The two chickpeas did not differ in CP content, and any of the measured in situ degradation and molecular spectral characteristics of protein. The content of RUP was positively (r = 0.94, P < 0.01) and that of RDP was negatively (r = -0.94, P < 0.01) correlated with amide I/II area ratio. The regression analysis showed that the content of CP (R2 = 0.91) D-fraction (R2 = 0.82), RDP (R2 = 0.77), RUP (R2 = 0.77), TDP (R2 = 0.98), MP (R2 = 0.80), and FMV (R2 = 0.80) can be predicted from amide II peak height. Despite extensive ruminal degradation, chickpea is a good source of MP for dairy cows, and molecular spectroscopy can be used to rapidly characterize feed protein molecular structures and predict their digestibility and nutritive value.

Two Distinct Types of CME-flare Relationships Based on SOHO and STEREO Observations

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

Jang, Soojeong; Moon, Yong-Jae; Kim, Rok-Soon

In this paper, we present two distinct types of coronal mass ejection (CME)-flare relationships according to their observing time differences using 107 events from 2010 to 2013. The observing time difference, Δ T , is defined as flare peak time minus CME first appearance time at Solar Terrestrial Relations Observatory ( STEREO ) COR1 field of view. There are 41 events for group A (Δ T < 0) and 66 events for group B (Δ T ≥ 0). We compare CME 3D parameters (speed and kinetic energy) based on multi-spacecraft data ( SOlar and Heliospheric Observatory ( SOHO ) andmore » STEREO A and B ) and their associated flare properties (peak flux, fluence, and duration). Our main results are as follows. First, there are better relationships between CME and flare parameters for group B than that of group A. In particular, CME 3D kinetic energy for group B is well correlated with flare fluence with the correlation coefficient of 0.67, which is much stronger than that (cc = 0.31) of group A. Second, the events belonging to group A have short flare durations of less than 1 hr (mean = 21 minutes), while the events for group B have longer durations up to 4 hr (mean = 81 minutes). Third, the mean value of height at peak speed for group B is 4.05 Rs, which is noticeably higher than that of group A (1.89 Rs). This is well correlated with the CME acceleration duration (cc = 0.75). A higher height at peak speed and a longer acceleration duration of CME for group B could be explained by the fact that magnetic reconnections for group B continuously occur for a longer time than those for group A.« less

Simultaneous Multiwavelength Observations of the Blazar 1ES 1959+650 at a Low TeV Flux

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

Tagliaferri, G.; Ghisellini, G.; Foschini, L.

We present the results from a multiwavelength campaign on the TeV blazar 1ES 1959+650, performed in 2006 May. Data from the optical, UV, soft- and hard-X-ray, and very high energy (VHE) gamma-ray (E > 100 GeV) bands were obtained with the Suzaku and Swift satellites, the MAGIC telescope, and other ground-based facilities. The source spectral energy distribution (SED), derived from Suzaku and MAGIC observations at the end of 2006 May, shows the usual double hump shape, with the synchrotron peak at a higher flux level than the Compton peak. With respect to historical values, during our campaign the source exhibitedmore » a relatively high state in X-rays and optical, while in the VHE band it was at one of the lowest level so far recorded. We also monitored the source for flux spectral variability on a time window of 10 days in the optical-UV and X-ray bands and 7 days in the VHE band. The source varies more in the X-ray than in the optical band, with the 2-10 keV X-ray flux varying by a factor of {approx}2. The synchrotron peak is located in the X-ray band and moves to higher energies as the source gets brighter, with the X-ray fluxes above it varying more rapidly than the X-ray fluxes at lower energies. The variability behavior observed in the X-ray band cannot be produced by emitting regions varying independently and suggests instead some sort of 'standing shock' scenario. The overall SED is well represented by a homogeneous one-zone synchrotron inverse Compton emission model, from which we derive physical parameters that are typical of high-energy peaked blazars.« less

Thermoluminescence of α-Al2O3:C,Mg annealed at 1200 °C

NASA Astrophysics Data System (ADS)

Kalita, J. M.; Chithambo, M. L.

2018-05-01

Stimulated luminescence in α-Al2O3:C,Mg has thus far been studied for samples annealed at temperature no higher than 900 °C as can be seen by an examination of the literature. We report the thermoluminescence (TL) features of α-Al2O3:C,Mg annealed at 1200 °C. A glow curve measured at 1 °C/s from the samples annealed at 1200 °C shows eight peaks at 54, 80, 102, 173, 238, 290, 330 and 387 °C. Kinetic analyses show that the peak at 54 °C follows general order kinetics (b = 1.3) whereas the rest follow first order kinetics. The values of the activation energy of the peaks are between 0.77 eV and 1.90 eV and the frequency factors are of the order of 1010-1014 s-1. The intensity of the peaks at 54, 80, 102 and 173 °C increase with heating rate whereas those of the peaks at 238 and 290 °C decrease with heating rate. The decrease of intensity of the peaks at 238 and 290 °C with heating rate is due to thermal quenching whereas the increase of intensity of the peaks with heating rate indicates an inverse thermal-quenching-like behaviour. Interestingly this behaviour is observed only after annealing at 1200 °C. The activation energy for thermal quenching as calculated using the peaks at 238 and 290 °C are (1.02 ± 0.16) eV and (1.33 ± 0.15) eV respectively. Regarding the dosimetric features, the dose response of the peaks at 54, 80 and 102 °C are sublinear within 1-10 Gy and the peak at 54 °C saturates above 6 Gy. In contrast, the response of the peak at 173 °C is sublinear with 1-4 Gy and superlinear between 4 and 10 Gy. The peaks are found to fade at different rates and the rate of fading is also affected by annealing.

Effects of inertia correction and resistive load on fatigue during repeated sprints on a friction-loaded cycle ergometer.

PubMed

Bogdanis, Gregory; Papaspyrou, Aggeliki; Lakomy, Henryk; Nevill, Mary

2008-11-01

Seven 6 s sprints with 30 s recovery between sprints were performed against two resistive loads: 50 (L50) and 100 (L100) g x kg(-1) body mass. Inertia-corrected and -uncorrected peak and mean power output were calculated. Corrected peak power output in corresponding sprints and the drop in peak power output relative to sprint 1 were not different in the two conditions, despite the fact that mean power output was 15-20% higher in L100 (P < 0.01). The effect of inertia correction on power output was more pronounced for the lighter load (L50), with uncorrected peak power output in sprint 1 being 42% lower than the corresponding corrected peak power output, while this was only 16% in L100. Fatigue assessed by the drop in uncorrected peak and mean power output in sprint 7 relative to sprint 1 was less compared with that obtained by corrected power values, especially in L50 (drop in uncorrected vs. corrected peak power output: 13.3 +/- 2.2% vs. 23.1 +/- 4.1%, P < 0.01). However, in L100, the difference between the drop in corrected and uncorrected mean power output in sprint 7 was much smaller (24.2 +/- 3.1% and 21.2 +/- 2.7%, P < 0.01), indicating that fatigue may be safely assessed even without inertia correction when a heavy load is used. In conclusion, when inertia correction is performed, fatigue during repeated sprints is unaffected by resistive load. When inertia correction is omitted, both power output and the fatigue profile are underestimated by an amount dependent on resistive load. In cases where inertia correction is not possible during a repeated sprints test, a heavy load may be preferable.

Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing Fissures Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach

NASA Astrophysics Data System (ADS)

Cao, Ri-hong; Cao, Ping; Lin, Hang; Pu, Cheng-zhi; Ou, Ke

2016-03-01

Joints and fissures with similar orientation or characteristics are common in natural rocks; the inclination and density of the fissures affect the mechanical properties and failure mechanism of the rock mass. However, the strength, crack coalescence pattern, and failure mode of rock specimens containing multi-fissures have not been studied comprehensively. In this paper, combining similar material testing and discrete element numerical method (PFC2D), the peak strength and failure characteristics of rock-like materials with multi-fissures are explored. Rock-like specimens were made of cement and sand and pre-existing fissures created by inserting steel shims into cement mortar paste and removing them during curing. The peak strength of multi-fissure specimens depends on the fissure angle α (which is measured counterclockwise from horizontal) and fissure number ( N f). Under uniaxial compressional loading, the peak strength increased with increasing α. The material strength was lowest for α = 25°, and highest for α = 90°. The influence of N f on the peak strength depended on α. For α = 25° and 45°, N f had a strong effect on the peak strength, while for higher α values, especially for the 90° sample, there were no obvious changes in peak strength with different N f. Under uniaxial compression, the coalescence modes between the fissures can be classified into three categories: S-mode, T-mode, and M-mode. Moreover, the failure mode can be classified into four categories: mixed failure, shear failure, stepped path failure, and intact failure. The failure mode of the specimen depends on α and N f. The peak strength and failure modes in the numerically simulated and experimental results are in good agreement.

Comparison of quartz standards for X-ray diffraction analysis: HSE A9950 (Sikron F600) and NIST SRM 1878.

PubMed

Chisholm, Jim

2005-06-01

A further comparison of the Health and Safety Executive (HSE) standard quartz, A9950 (Sikron F600), and the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1878, standard respirable alpha-quartz, has been carried out for the four principal diffraction peaks. In the earlier comparison by Jeyaratnam and Nagar (1993, Ann Occup Hyg; 37: 167-79), the standards were both treated in ways which might change the particle size distribution and therefore the proportion of crystalline quartz. The two standards have now been compared in the most direct way possible with the minimum of sample treatment. There are no significant differences in the diffraction peak positions for the two standards. Nor do the peak area intensities differ significantly. The peak height intensities are consistently and significantly higher for Sikron F600 than for NIST SRM 1878. The particle size broadening of the diffraction peaks is evidently greater for NIST 1878, whose mass median diameter is quoted as 1.6 microm against 2.6 microm for Sikron F600. Taking the certified reference value for SRM 1878 as 95.5 +/- 1.1% crystalline quartz, the HSE standard A9950 (Sikron F600) contains 96.3 +/- 1.4% crystalline quartz based on a comparison of peak area intensities. On the same basis but using peak height intensities, the nominal crystalline quartz content of A9950 (Sikron F600) is 101.2 +/- 1.8%. Results obtained by comparison of quartz standards may not be generally applicable because of the effect of sample treatment on particle size and crystalline quartz content.

Harnessing Solar Energy Using Photosynthetic and Organic Pigments

NASA Astrophysics Data System (ADS)

Fitzsimons, Toby Ryan

Fossil fuels are a finite energy resource that must be supplemented or replaced by more stable forms of electrical energy. Solar technology research strives to supplement and provide eventual replacement for fossil fuel technology. This experiment focused on the use of natural pigments as photo-sensitizers in the current generation of solar cells called dye sensitized solar cells (DSSCs). Pigments from purified chlorophyll a, chlorophyll b, chlorophyll a/b, crude spinach (Spinacia oleracea) extract, phycocyanin, and chlorophyllin were used to construct DSSCs and evaluated, along with a control containing no pigment, for solar energy conversion. The anode of the solar cells consisted of titanium dioxide (TiO2) plates soaked in pigment solutions for twenty-four hours. The plates were assembled, along with an electrolyte sandwiched between cells, and a platinum-coated counter plate that functioned as the cathode. A gasket seal was placed between the plates and held together with rubber bands. The DSSCs were each tested for a maximum power (Pmax) point and a resistor was selected that corresponded to the resistance at that point. The cells were randomly placed into a power block assembly located in an environmental chamber with lighting that provided an average of 27,590 lumens at the surface of DSSCs. With appropriate resistors in place, the cells were subjected to twelve-hour days and twelve-hour nights for ten days, and measurements were recorded every ten minutes. Data were collected to obtain values for voltage in millivolts (mV), current in microamps (microA), and power in microwatts (microW), as well as beginning and ending efficiencies in converting light to usable energy. Voltages were substantially higher during the day than at night for all pigments, except for the control, indicating that the pigments functioned as DSSCs. Hence, only daytime values were used for data analysis. Voltage during the ten-day experiment ranged from 3.99 to 274 mV; current ranged from 0.0180 to 41.9 microA, and power ranged from 0.00 to 11.3 microW. Chlorophyllin had the highest peak and least voltage (274 and 161 mV), highest peak and least current (41.9 and 21.8 microA), and highest peak and least power (11.3 and 4.84 microW). The ranking of the pigments for peak voltage was: Chlorophyllin = Crude Extract ≥ Chlorophyll a = Chlorophyll a/b ≥ Phycocyanin = Chlorophyll b > Control. The ranking for least voltage was: Chlorophyllin > Phycocyanin ≥ Chlorophyll a/b ≥ Crude Extract ≥ Chlorophyll b ≥ Chlorophyll a ≥ Control. Ranking for peak and least values were similar for current and power. Solar energy conversion (efficiency in converting light energy to usable energy in watts per square meter) for all treatments ranged from 0.000595 to 0.0217% at the beginning of the experiment, and was highest in cells constructed with chlorophyllin. Based on rankings from peak and ending voltage values, as well as other measurements, it was concluded that DSSCs constructed with chlorophyllin performed the best and lasted the longest as photo-sensitizers, compared to other pigments used in this investigation. The DSSCs constructed with crude extract performed almost as well as those constructed with chlorophyllin at the beginning of the experiment, but degradation of this naturally-made pigment may have prevented these cells from sustaining solar energy conversion for more than a few days. Other pigments demonstrated conversion values higher than those of control DSSCs which contained no pigments. The results from this project provide evidence that DSSCs can produce useable energy. More research is needed to enhance and prolong the efficiency of DSSCs in solar energy conversion.

Protein assignments without peak lists using higher-order spectra.

PubMed

Benison, Gregory; Berkholz, Donald S; Barbar, Elisar

2007-12-01

Despite advances in automating the generation and manipulation of peak lists for assigning biomolecules, there are well-known advantages to working directly with spectra: the eye is still superior to computer algorithms when it comes to picking out peak relationships from contour plots in the presence of confounding factors such as noise, overlap, and spectral artifacts. Here, we present constructs called higher-order spectra for identifying, through direct visual examination, many of the same relationships typically identified by searching peak lists, making them another addition to the set of tools (alongside peak picking and automated assignment) that can be used to solve the assignment problem. The technique is useful for searching for correlated peaks in any spectrum type. Application of this technique to novel, complete sequential assignment of two proteins (AhpFn and IC74(84-143)) is demonstrated. The program "burrow-owl" for the generation and display of higher-order spectra is available at (http://sourceforge.net/projects/burrow-owl) or from the authors.

CME productivity associated with Solar Flare peak X-ray emission flux

NASA Astrophysics Data System (ADS)

Suryanarayana, G. S.; Balakrishna, K. M.

2018-05-01

It is often noticed that the occurrence rate of Coronal Mass Ejections (CMEs) increases with increase in flare duration where peak flux too increase. However, there is no complete association between the duration and peak flux. Distinct characteristics have been reported for active regions (ARs) where flares and CMEs occur in contrast to ARs where flares alone occur. It is observed that peak flux of flares is higher when associated with CMEs compared to peak flux of flares with which CMEs are not associated. In other words, it is likely that flare duration and peak flux are independently affected by distinct active region dynamics. Hence, we examine the relative ability of flare duration and peak flux in enhancing the CME productivity. We report that CME productivity is distinctly higher in association with the enhancement of flare peak flux in comparison to corresponding enhancement of flare duration.

Human occupants in low-speed frontal sled tests: effects of pre-impact bracing on chest compression, reaction forces, and subject acceleration.

PubMed

Kemper, Andrew R; Beeman, Stephanie M; Madigan, Michael L; Duma, Stefan M

2014-01-01

The purpose of this study was to investigate the effects of pre-impact bracing on the chest compression, reaction forces, and accelerations experienced by human occupants during low-speed frontal sled tests. A total of twenty low-speed frontal sled tests, ten low severity (∼2.5g, Δv=5 kph) and ten medium severity (∼5g, Δv=10 kph), were performed on five 50th-percentile male human volunteers. Each volunteer was exposed to two impulses at each severity, one relaxed and the other braced prior to the impulse. A 59-channel chestband, aligned at the nipple line, was used to quantify the chest contour and anterior-posterior sternum deflection. Three-axis accelerometer cubes were attached to the sternum, 7th cervical vertebra, and sacrum of each subject. In addition, three linear accelerometers and a three-axis angular rate sensor were mounted to a metal mouthpiece worn by each subject. Seatbelt tension load cells were attached to the retractor, shoulder, and lap portions of the standard three-point driver-side seatbelt. In addition, multi-axis load cells were mounted to each interface between the subject and the test buck to quantify reaction forces. For relaxed tests, the higher test severity resulted in significantly larger peak values for all resultant accelerations, all belt forces, and three resultant reaction forces (right foot, seatpan, and seatback). For braced tests, the higher test severity resulted in significantly larger peak values for all resultant accelerations, and two resultant reaction forces (right foot and seatpan). Bracing did not have a significant effect on the occupant accelerations during the low severity tests, but did result in a significant decrease in peak resultant sacrum linear acceleration during the medium severity tests. Bracing was also found to significantly reduce peak shoulder and retractor belt forces for both test severities, and peak lap belt force for the medium test severity. In contrast, bracing resulted in a significant increase in the peak resultant reaction force for the right foot and steering column at both test severities. Chest compression due to belt loading was observed for all relaxed subjects at both test severities, and was found to increase significantly with increasing severity. Conversely, chest compression due to belt loading was essentially eliminated during the braced tests for all but one subject, who sustained minor chest compression due to belt loading during the medium severity braced test. Overall, the data from this study illustrate that muscle activation has a significant effect on the biomechanical response of human occupants in low-speed frontal impacts.

Chronotropic Incompetence and its Relation to Exercise Intolerance in Chronic Obstructive Pulmonary Disease.

PubMed

Liu, Hai-Jian; Guo, Jian; Zhao, Qin-Hua; Wang, Lan; Yang, Wen-Lan; He, Jing; Gong, Su-Gang; Liu, Jin-Ming

2017-03-01

To study the relationship between chronotropic incompetence (CI) and disease severity and to assess the effect of CI on exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Arterial blood gas analysis, pulmonary function test and cardiopulmonary exercise testing were conducted in 60 patients with stable COPD and 45 healthy volunteers. CI was defined using the chronotropic response index (CRI = (peak heart rate-resting heart rate) / (220-age-resting heart rate). Based on CRI, patients with COPD were divided into the normal chronotropic group (n = 23) and CI group (n = 37). CI was present in 61.7% of the patients with COPD. Exercise capacity (peak oxygen uptake as percentage of predicted value, peak VO 2 %pred), peak heart rate and CRI were significantly lower in patients with COPD than in controls. However, resting heart rate was significantly higher than in controls. FEV 1 %pred and exercise capacity were significantly decreased in the CI group when compared with those in the normotropic group. There was significant association between CRI with FEV 1 %pred and peak VO 2 %pred. Multivariate regression analysis showed that CRI and FEV 1 %pred were independent predictors of exercise capacity in patients with COPD. A cutoff of 0.74 for the CRI showed a specificity of 94.1% in predicting patients with a peak VO 2 %pred < 60%. CRI was associated with disease severity in patients with COPD. CI may be an important parameter to reflect exercise capacity in patients with COPD. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Analysis of the Characteristics and Evolution Modes of PM2.5 Pollution Episodes in Beijing, China During 2013

PubMed Central

Song, Ci; Pei, Tao; Yao, Ling

2015-01-01

Fine particulate matter (PM2.5) has been recognized as a serious hazard linked to deleterious health effects. In this study, all PM2.5 Pollution Episodes (PPEs) in Beijing during 2013 were investigated with hourly PM2.5 observations from the Olympic Sport Center site, and then their characteristics and evolution modes analysed. Results show that 80 PPEs, covering 209 days, occurred in Beijing during 2013. Average PM2.5 concentrations during PPEs were almost twice (1.86) the annual mean value, although the PPEs showed significant seasonal variations. The most hazardous PPEs tended to occur in winter, whereas PPEs with long duration occurred in autumn. The PPEs could be divided into six clusters based on their compositions of different pollution levels, which were strongly related to meteorological factors. We used series peaks of PM2.5 concentrations to analyse the evolution modes of PPEs and found that the more peaks there were within the evolution mode, the longer the duration, and the higher the average and maximum PM2.5 concentrations. Each peak within a PPE can be identified by “rise” and “fall” patterns. The “rise” patterns are widely related to relative humidity, whereas the “fall” patterns are affected principally by wind speed for one-peak PPEs and boundary layer height for multi-peak PPEs. The peak patterns cannot be explained fully by meteorological factors; however, they might also be closely related to complex and diversified human activities. PMID:25648172

Poloidal radiation asymmetries during disruption mitigation by massive gas injection on the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Eidietis, N. W.

2016-10-01

Measurements of poloidal asymmetry in the radiated power during thermal quench (TQ) mitigation by massive gas injection (MGI) on DIII-D show poloidal peaking in the radiated heat flux at the wall generally consistent with 3D resistive MHD modeling, that indicates a large n=1 tearing mode causes these asymmetries. Radiation asymmetries are a concern to ITER because they can cause localized melting of the first wall even if globally the mitigation successfully radiates 100% of the plasma thermal energy. Toroidal radiation asymmetries have been well-studied, but until now the equally important poloidal asymmetries were not well constrained. Radiation emissivity profiles are reconstructed by tomographic inversion of AXUV photodiode arrays, from which the peaking measurements are derived. The poloidal peaking measurements are compared to NIMROD 3D resistive MHD simulations. Qualitatively, the measured and modeled peaking evolve similarly. In both cases, peaking during the TQ changes little with toroidal phase, consistent with predictions of n=1 MHD during the TQ producing the asymmetry. Quantitatively, the measured TQ peaking amplitudes are comparable to but consistently higher than the modeled values. This is a result of the measured radiation exhibiting high emissivity lobes at larger minor radius (and outside the separatrix) than the modeled cases, which may indicate incomplete treatment of the plasma-neutral interaction at the plasma edge in the model. This work, combined with previous measurement and modeling and toroidal radiation asymmetries, provides a basis for constraining localized mitigation radiation heat flux in ITER. Work supported by US DOE under DE-FC02-04ER54698.

Usefulness of cardiopulmonary exercise testing to predict the development of arterial hypertension in adult patients with repaired isolated coarctation of the aorta.

PubMed

Buys, Roselien; Van De Bruaene, Alexander; Müller, Jan; Hager, Alfred; Khambadkone, Sachin; Giardini, Alessandro; Cornelissen, Véronique; Budts, Werner; Vanhees, Luc

2013-10-03

Patients who underwent surgery for aortic coarctation (COA) have an increased risk of arterial hypertension. We aimed at evaluating (1) differences between hypertensive and non-hypertensive patients and (2) the value of cardiopulmonary exercise testing (CPET) to predict the development or progression of hypertension. Between 1999 and 2010, CPET was performed in 223 COA-patients of whom 122 had resting blood pressures of <140/90 mmHg without medication, and 101 were considered hypertensive. Comparative statistics were performed. Cox regression analysis was used to assess the relation between demographic, clinical and exercise variables and the development/progression of hypertension. At baseline, hypertensive patients were older (p=0.007), were more often male (p=0.004) and had repair at later age (p=0.008) when compared to normotensive patients. After 3.6 ± 1.2 years, 29/120 (25%) normotensive patients developed hypertension. In normotensives, VE/VCO2-slope (p=0.0016) and peak systolic blood pressure (SBP; p=0.049) were significantly related to the development of hypertension during follow-up. Cut-off points related to higher risk for hypertension, based on best sensitivity and specificity, were defined as VE/VCO2-slope ≥ 27 and peak SBP ≥ 220 mmHg. In the hypertensive group, antihypertensive medication was started/extended in 48/101 (48%) patients. Only age was associated with the need to start/extend antihypertensive therapy in this group (p=0.042). Higher VE/VCO2-slope and higher peak SBP are risk factors for the development of hypertension in adults with COA. Cardiopulmonary exercise testing may guide clinical decision making regarding close blood pressure control and preventive lifestyle recommendations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Evaluation of hyperglycaemic response to intra-operative dexamethasone administration in patients undergoing elective intracranial surgery: A randomised, prospective study.

PubMed

Sethi, Rakesh; Naqash, Imtiaz A; Bajwa, Sukhminder Jit Singh; Dutta, Vikas; Ramzan, Altaf Umar; Zahoor, Syed Amir

2016-01-01

The glucocorticoid dexamethasone in a bolus dose of 8-10 mg followed by quarterly dose of 4 mg is commonly used during intracranial surgery so as to reduce oedema and vascular permeability. However, the detrimental hyperglycaemic effects of dexamethasone may override its potentially beneficial effects. The present prospective, randomised study aimed at comparing the degree and magnitude of hyperglycaemia induced by prophylactic administration of dexamethasone in patients undergoing elective craniotomy. Sixty American Society of Anaesthesiologist (ASA) grade-I and II patients were randomly assigned to three groups of 20 patients each. Group-I received dexamethasone during surgery for the first time. Group-II received dexamethasone in addition to receiving it pre-operatively, whereas Group-III (control group) patients were administered normal saline as placebo. Baseline blood glucose (BG) was measured in all the three groups before induction of anaesthesia and thereafter after every hour for 4 h and then two-hourly. Besides intra- and intergroup comparison of BG, peak BG concentration was also recorded for each patient. Statistical analysis was carried out with analysis of variance (ANOVA) and Student's t-test and value of P < 0.05 was considered statistically significant. Baseline BG reading were higher and statistically significant in Group-II as compared with Group-I and Group-III (P < 0.05). However, peak BG levels were significantly higher in Group-I than in Group-II and III (P < 0.05). Similarly, the magnitude of change in peak BG was significantly higher in Group-I as compared to Group-II and III (P < 0.05). Peri-operative administration of dexamethasone during neurosurgical procedures can cause significant increase in BG concentration especially in patients who receive dexamethasone intra-operatively only.

Evaluation of hyperglycaemic response to intra-operative dexamethasone administration in patients undergoing elective intracranial surgery: A randomised, prospective study

PubMed Central

Sethi, Rakesh; Naqash, Imtiaz A.; Bajwa, Sukhminder Jit Singh; Dutta, Vikas; Ramzan, Altaf Umar; Zahoor, Syed Amir

2016-01-01

Background and Aim: The glucocorticoid dexamethasone in a bolus dose of 8-10 mg followed by quarterly dose of 4 mg is commonly used during intracranial surgery so as to reduce oedema and vascular permeability. However, the detrimental hyperglycaemic effects of dexamethasone may override its potentially beneficial effects. The present prospective, randomised study aimed at comparing the degree and magnitude of hyperglycaemia induced by prophylactic administration of dexamethasone in patients undergoing elective craniotomy. Materials and Methods: Sixty American Society of Anaesthesiologist (ASA) grade-I and II patients were randomly assigned to three groups of 20 patients each. Group-I received dexamethasone during surgery for the first time. Group-II received dexamethasone in addition to receiving it pre-operatively, whereas Group-III (control group) patients were administered normal saline as placebo. Baseline blood glucose (BG) was measured in all the three groups before induction of anaesthesia and thereafter after every hour for 4 h and then two-hourly. Besides intra- and intergroup comparison of BG, peak BG concentration was also recorded for each patient. Statistical analysis was carried out with analysis of variance (ANOVA) and Student's t-test and value of P < 0.05 was considered statistically significant. Results: Baseline BG reading were higher and statistically significant in Group-II as compared with Group-I and Group-III (P < 0.05). However, peak BG levels were significantly higher in Group-I than in Group-II and III (P < 0.05). Similarly, the magnitude of change in peak BG was significantly higher in Group-I as compared to Group-II and III (P < 0.05). Conclusion: Peri-operative administration of dexamethasone during neurosurgical procedures can cause significant increase in BG concentration especially in patients who receive dexamethasone intra-operatively only. PMID:27057213

Relationships between heart rate target determined in different exercise testing in COPD patients to prescribed with individualized exercise training.

PubMed

Fabre, Claudine; Chehere, Baptiste; Bart, Frédéric; Mucci, Patrick; Wallaert, Benoit; Grosbois, Jean Marie

2017-01-01

It has been scientifically proven that pulmonary rehabilitation improves exercise tolerance and facilitates the carrying out of daily physical activities. To optimize the physical and physiological benefits, it is necessary to individualize the training intensity for each patient. The aim of this study is to compare the heart rate (HR) responses to three exercise modalities measuring aerobic fitness in chronic obstructive pulmonary disease patients, in order to easily prescribe individual target HRs for endurance training. Fifty COPD patients (mean age: 60.1±8.5 years) were included in the study. Each patient carried out a cardiopulmonary exercise test, a 6-minute walk test (6MWT) and a 6-minute stepper test (6MST). During these tests, HR was recorded continuously. After the cardiopulmonary exercise test, the HR was noted at the ventilatory threshold (VT) and at the end of the two exercise field tests (6MWT peak and 6MST peak ). The values of the HR during the last 3 minutes of both field tests were averaged (6MWT 456 and 6MST 456 ). Finally, the HR at 60% of the HR reserve was calculated with the values of the HR measured during 6MWT and 6MST (HRr 60%walk , HRr 60%step ). The HRs measured during the 6MST were significantly higher than those measured during the 6MWT. The HRr 60%step was not significantly different from 6MWT 456 and 6MWT peak HR ( P =0.51; P =0.48). A significant correlation was observed between 6MWT 456 and 6MWT peak ( r =0.58). The 6MWT 456 and 6MWT peak HR were correlated with HRr 60%step ( r =0.68 and r =0.62). The VT could be determined in 28 patients. The HR VT was not different from 6MWT 456 , 6MWT peak , and HRr 60%step ( P =0.57, P =0.41 and P =0.88) and was correlated to 6MWT 456 , 6MWT peak , and HRr 60%step ( r =0.45, r =0.40, r =0.48). An individualized target HR for endurance training can be prescribed from the HR measured during routine tests, such as 6MWT or 6MST.

The U.S. Geological Survey Peak-Flow File Data Verification Project, 2008–16

USGS Publications Warehouse

Ryberg, Karen R.; Goree, Burl B.; Williams-Sether, Tara; Mason, Robert R.

2017-11-21

Annual peak streamflow (peak flow) at a streamgage is defined as the maximum instantaneous flow in a water year. A water year begins on October 1 and continues through September 30 of the following year; for example, water year 2015 extends from October 1, 2014, through September 30, 2015. The accuracy, characterization, and completeness of the peak streamflow data are critical in determining flood-frequency estimates that are used daily to design water and transportation infrastructure, delineate flood-plain boundaries, and regulate development and utilization of lands throughout the United States and are essential to understanding the implications of climate and land-use change on flooding and high-flow conditions.As of November 14, 2016, peak-flow data existed for 27,240 unique streamgages in the United States and its territories. The data, collectively referred to as the “peak-flow file,” are available as part of the U.S. Geological Survey (USGS) public web interface, the National Water Information System, at https://nwis.waterdata.usgs.gov/usa/nwis/peak. Although the data have been routinely subjected to periodic review by the USGS Office of Surface Water and screening at the USGS Water Science Center level, these data were not reviewed in a national, systematic manner until 2008 when automated scripts were developed and applied to detect potential errors in peak-flow values and their associated dates, gage heights, and peak-flow qualification codes, as well as qualification codes associated with the gage heights. USGS scientists and hydrographers studied the resulting output, accessed basic records and field notes, and corrected observed errors or, more commonly, confirmed existing data as correct.This report summarizes the changes in peak-flow file data at a national level, illustrates their nature and causation, and identifies the streamgages affected by these changes. Specifically, the peak-flow data were compared for streamgages with peak flow measured as of November 19, 2008 (before the automated scripts were widely applied) and on November 14, 2016 (after several rounds of corrections). There were 659,332 peak-flow values in the 2008 dataset and 731,965 peak-flow values in the 2016 dataset. When compared to the 2016 dataset, 5,179 (0.79 percent) peak-flow values had changed; 36,506 (5.54 percent) of the peak-flow qualification codes had changed; 1,938 (0.29 percent) peak-flow dates had changed; 18,599 (2.82 percent) of the peak-flow gage heights had changed; and 20,683 (3.14 percent) of the gage-height qualification codes had changed—most as a direct result of the peak-flow file data verification effort led by USGS personnel. The various types of changes are summarized and mapped in this report. In addition to this report, a corresponding USGS data release is provided to identify changes in peak flows at individual streamgages. The data release and the procedures to access the data release are described in this report.

Estimation of Heat Transfer Coefficient in Squeeze Casting of Magnesium Alloy AM60 by Experimental Polynomial Extrapolation Method

NASA Astrophysics Data System (ADS)

Sun, Zhizhong; Niu, Xiaoping; Hu, Henry

In this work, a different wall-thickness 5-step (with thicknesses as 3, 5, 8, 12, 20 mm) casting mold was designed, and squeeze casting of magnesium alloy AM60 was performed in a hydraulic press. The casting-die interfacial heat transfer coefficients (IHTC) in 5-step casting were determined based on experimental thermal histories data throughout the die and inside the casting which were recorded by fine type-K thermocouples. With measured temperatures, heat flux and IHTC were evaluated using the polynomial curve fitting method. The results show that the wall thickness affects IHTC peak values significantly. The IHTC value for the thick step is higher than that for the thin steps.

Relaxation distribution function of intracellular dielectric zones as an indicator of tumorous transition of living cells.

PubMed

Thornton, B S; Hung, W T; Irving, J

1991-01-01

The response decay data of living cells subject to electric polarization is associated with their relaxation distribution function (RDF) and can be determined using the inverse Laplace transform method. A new polynomial, involving a series of associated Laguerre polynomials, has been used as the approximating function for evaluating the RDF, with the advantage of avoiding the usual arbitrary trial values of a particular parameter in the numerical computations. Some numerical examples are given, followed by an application to cervical tissue. It is found that the average relaxation time and the peak amplitude of the RDF exhibit higher values for tumorous cells than normal cells and might be used as parameters to differentiate them and their associated tissues.

QRS peak detection for heart rate monitoring on Android smartphone

NASA Astrophysics Data System (ADS)

Pambudi Utomo, Trio; Nuryani, Nuryani; Darmanto

2017-11-01

In this study, Android smartphone is used for heart rate monitoring and displaying electrocardiogram (ECG) graph. Heart rate determination is based on QRS peak detection. Two methods are studied to detect the QRS complex peak; they are Peak Threshold and Peak Filter. The acquisition of ECG data is utilized by AD8232 module from Analog Devices, three electrodes, and Microcontroller Arduino UNO R3. To record the ECG data from a patient, three electrodes are attached to particular body’s surface of a patient. Patient’s heart activity which is recorded by AD8232 module is decoded by Arduino UNO R3 into analog data. Then, the analog data is converted into a voltage value (mV) and is processed to get the QRS complex peak. Heart rate value is calculated by Microcontroller Arduino UNO R3 uses the QRS complex peak. Voltage, heart rate, and the QRS complex peak are sent to Android smartphone by Bluetooth HC-05. ECG data is displayed as the graph by Android smartphone. To evaluate the performance of QRS complex peak detection method, three parameters are used; they are positive predictive, accuracy and sensitivity. Positive predictive, accuracy, and sensitivity of Peak Threshold method is 92.39%, 70.30%, 74.62% and for Peak Filter method are 98.38%, 82.47%, 83.61%, respectively.

Intravascular enhancement with identical iodine delivery rate using different iodine contrast media in a circulation phantom.

PubMed

Mihl, Casper; Wildberger, Joachim E; Jurencak, Tomas; Yanniello, Michael J; Nijssen, Estelle C; Kalafut, John F; Nalbantov, Georgi; Mühlenbruch, Georg; Behrendt, Florian F; Das, Marco

2013-11-01

Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR. A circulation phantom with a low-pressure venous compartment and a high-pressure arterial compartment simulating physiological circulation parameters was used (heart rate, 60 beats per minute; stroke volume, 60 mL; blood pressure, 120/80 mm Hg). Maintaining a constant IDR (2.0 g/s) and a constant total iodine load (20 g), prewarmed (37°C) contrast media with differing iodine concentrations (240-400 mg/mL) were injected into the phantom using a double-headed power injector. Serial computed tomographic scans at the level of the ascending aorta (AA), the descending aorta (DA), and the left main coronary artery (LM) were obtained. Total amount of contrast volume (milliliters), iodine delivery (grams of iodine), peak flow rate (milliliter per second), and intravascular pressure (pounds per square inch) were monitored using a dedicated data acquisition program. Attenuation values in the AA, the DA, and the LM were constantly measured (Hounsfield unit [HU]). In addition, time-enhancement curves, aortic peak enhancement, and time to peak were determined. All contrast injection protocols resulted in similar attenuation values: the AA (516 [11] to 531 [37] HU), the DA (514 [17] to 531 [32] HU), and the LM (490 [10] to 507 [17] HU). No significant differences were found between the AA, the DA, and the LM for either peak enhancement (all P > 0.05) or mean time to peak (AA, 19.4 [0.58] to 20.1 [1.05] seconds; DA, 21.1 [1.0] to 21.4 [1.15] seconds; LM, 19.8 [0.58] to 20.1 [1.05] seconds). This phantom study demonstrates that constant injection parameters (IDR, overall iodine load) lead to robust enhancement patterns, regardless of the contrast material used. Higher iodine concentration itself does not lead to higher attenuation levels. These results may stimulate a shift in paradigm toward clinical usage of contrast media with lower iodine concentrations (eg, 240 mg iodine/mL) in individual tailored contrast protocols. The use of low-iodine concentration contrast media is desirable because of the lower viscosity and the resulting lower injection pressure.

Preliminary Results From the Chicxulub Post-Impact Sediments: XRF and Physical Properties Data

NASA Astrophysics Data System (ADS)

Gebhardt, C.; Perez-Cruz, L. L.; Chenot, É.; Christeson, G. L.; Le Ber, E.; Lofi, J.; Nixon, C.; Rae, A.; Expedition 364 Science Party, I. I.

2017-12-01

In spring 2016, joint IODP/ICDP Expedition 364 drilled into the peak ring of the Chicxulub crater, offshore the Yucatan Peninsula, Mexico. A continuous core was drilled (Hole M0077A) and recovered a sequence of Paleogene post-impact rocks, suevites, impact-melt rocks and granitic basement between 505.7 m and 1334.7 m below sea floor (bsf). The Chicxulub crater was formed 66 million years ago by an impact. This catastrophic event was directly linked to a major mass extinction. For this study, we concentrate on the post-impact sediments (505.7 to 617.3 m bsf; 48 to 66 Ma). The main goal of drilling the post-impact section was to study the pace and mode of recovery of life in the ocean after the impact, and to analyze the paleoenvironmental changes across the Paleocene and Eocene. The late Paleocene and Eocene are characterized by a series of transient warming events, so-called hyperthermals that were associated with increased atmospheric pCO2. Here, we present preliminary geochemical and physical properties data from the 112 m of Paleogene sediments. XRF data show high log (Ca/Ti) values between 617 and 598 m bsf (Paleocene and early Eocene), and lower values between 598 and 505 m bsf. In particular the upper part is characterized by high-frequency fluctuations in log (Ca/Ti) reflecting repeated changes in lithology. These were presumably caused by Milankovitch cycles. Low log (Ba/Ti) values characterize the lowermost part of the record between 617 and 610, followed by a gradual increase to higher values, presumably indicating an increase in primary productivity towards the end of the Paleocene. Values remain at this higher level between 605 and 540 m bsf. Hyperthermals are characterized by strong positive log (Ba/Ti) peaks, likely pointing at highly elevated primary productivity levels during these short-lived events. Between 540 and 505 m bsf, log (Ba/Ti) values are more variable and drop occasionally to values as low as were encountered in the lowermost part. Similar to the log Ca/Ti curve, the log Ba/Ti curve is superimposed by high-frequency fluctuations. These fluctuations are also strongly visible in color reflectance measurements.

Arctic boundary layer properties and its influence on cloud occurrence frequency, phase and structure in autumn season

NASA Astrophysics Data System (ADS)

Qiu, S.; Dong, X.; Xi, B.

2017-12-01

In this study, autumnal boundary layer characteristics and cloud properties have been investigated using data collected at the Atmospheric Radiation Measurement North Slope of Alaska (ARM NSA) site from January 2002 to December 2008. We found that both cloud and planetary boundary layer (PBL) properties can be well distinguished by surface wind directions. When the ARM NSA site is dominated by a northerly wind during the period September- November, the PBL is at near saturation for all three months; while the maximum RH layer varies from low and thin in September, to higher and thicker in October, and then it becomes close to surface again in November. Both the ceilometer and the MPL derived cloud base heights coincide well with the RH maximum layer in the PBL for all three autumnal months. The frequencies of occurrence of mixed phase clouds in September and October are around 60-80% under a northerly wind, which are about 1.5 times higher than those during a southerly wind. Under northerly wind, the PDFs of PBL temperature and specific humidity are narrow and unimodal, with a peak probability around 0.4-0.5. Under a southerly wind, on the other hand, the PBL is both warmer and wetter than northerly wind profiles, which result in lower RH values (10-15% lower) in September and October; and the PDFs of PBL temperature and specific humidity are more evenly distributed with larger distribution range and lower PDF peak values (<0.3). In September, colder and dryer PBL is more favorable for mixed phase cloud formation, cloud occurrence frequency decreases from 90% to 60% as PBL temperature and specific humidity increase. In October, the frequency of occurrence of mixed phase clouds also decreases from 90% to 50-60% as PBL temperature increases. While in November, it increases first and then decreases with increasing PBL temperature and specific humidity. The frequency of occurrence of mixed phase clouds is linearly correlated to PBL RH values: for all three months, it increases from 20-90% as PBL RH value increases from 50-100%, with R2 values of 0.85-0.95. Liquid-only cloud occurrence frequency has little relationship with PBL RH values, while it increases from 1% to 20% as PBL specific humidity increases from 0-5 g/kg, with R2 values of 0.6-0.85.

Fluorescence emission and polarization analyses for evaluating binding of ruthenium metalloglycoclusters to lectins and tetanus toxin C-fragment

NASA Astrophysics Data System (ADS)

Okada, Tomoko; Minoura, Norihiko

2011-03-01

We develop a fluorescent ruthenium metalloglycocluster for use as a powerful molecular probe in evaluating the binding between carbohydrates and lectins by fluorescence emission (FE) and fluorescence polarization (FP) analyses. Changes in the FE and FP of these metalloglycoclusters are measured following the addition of lectin [peanut agglutinin (PNA), Ricinus communis agglutinin 120, Concanavalin A (ConA), or wheat germ agglutinin] or tetanus toxin c-fragment (TCF). After the addition of PNA, the FE spectrum of [Ru(bpy-2Gal)3] shows a new emission peak and the FP value of [Ru(bpy-2Gal)3] increases. Similarly, the FE spectrum of [Ru(bpy-2Glc)3] shows a new emission peak and the FP value increases on addition of ConA. Because other combinations of metalloglycoclusters and lectins show little change, specific binding of galactose to PNA and that of glucose to ConA are confirmed by the FE and FP measurements. Resulting dissociation constants (Kd) prove that the metalloglycoclusters with highly clustered carbohydrates show higher affinity for the respective lectins than those with less clustered carbohydrates. Furthermore, specific binding of [Ru(bpy-2Gal)3] to TCF was confirmed by the FP measurement.

First-principles investigation of graphitic carbon nitride monolayer with embedded Fe atom

NASA Astrophysics Data System (ADS)

Abdullahi, Yusuf Zuntu; Yoon, Tiem Leong; Halim, Mohd Mahadi; Hashim, Md. Roslan; Lim, Thong Leng

2018-01-01

Density-functional theory (DFT) calculations with spin-polarized generalized gradient approximation and Hubbard U correction are carried out to investigate the mechanical, structural, electronic and magnetic properties of graphitic heptazine with embedded Fe atom under bi-axial tensile strain and applied perpendicular electric field. It was found that the binding energy of heptazine with embedded Fe atom system decreases as larger tensile strain is applied, while it increases as larger electric field strength is applied. Our calculations also predict a band gap at a peak value of 5% tensile strain but at expense of the structural stability of the system. The band gap open up at 5% tensile strain is due to distortion in the structure caused by the repulsive effect in the cavity between the lone pairs of the edge nitrogen atoms and dxy /dx2 -y2 orbital of Fe atom, forcing the unoccupied pz- orbital is forced to shift toward higher energy. The electronic and magnetic properties of the heptazine with embedded Fe system under perpendicular electric field up to a peak value of 8 V/nm is also well preserved despite an obvious buckled structure. Such properties are desirable for diluted magnetic semiconductors, spintronics, and sensing devices.

Analysis of a self-propelling sheet with heat transfer through non-isothermal fluid in an inclined human cervical canal.

PubMed

Walait, Ahsan; Siddiqui, A M; Rana, M A

2018-02-13

The present theoretical analysis deals with biomechanics of the self-propulsion of a swimming sheet with heat transfer through non-isothermal fluid filling an inclined human cervical canal. Partial differential equations arising from the mathematical modeling of the proposed model are solved analytically. Flow variables like pressure gradient, propulsive velocity, fluid velocity, time mean flow rate, fluid temperature, and heat-transfer coefficients are analyzed for the pertinent parameters. Striking features of the pumping characteristics are explored. Propulsive velocity of the swimming sheet becomes faster for lower Froude number, higher Reynolds number, and for a vertical channel. Temperature and peak value of the heat-transfer coefficients below the swimming sheet showed an increase by the increment of Brinkmann number, inclination, pressure difference over wavelength, and Reynolds number whereas these quantities decrease with increasing Froude number. Aforesaid parameters have shown opposite effects on the peak value of the heat-transfer coefficients below and above the swimming sheet. Relevance of the current results to the spermatozoa transport with heat transfer through non-isothermal cervical mucus filling an inclined human cervical canal is also explored.

Diurnal variation in peak expiratory flow rate among polyvinylchloride compounding workers.

PubMed Central

Lee, H S; Ng, T P; Ng, Y L; Phoon, W H

1991-01-01

The diurnal variation in peak expiratory flow rate (PEFR) was studied in 24 mixers and 24 non-mixers in three polyvinylchloride (PVC) compounding plants and 24 non-PVC controls from a marine police workshop. The three groups (all men) were matched for age, race, and smoking. The mean respirable dust concentration (essentially PVC dust) was 1.6 mg/m3 for mixers and 0.4 mg/m3 for nonmixers. The mean diurnal variation in PEFR of the mixers was 6.5%. This was significantly higher than the 4.8% for non-mixers and 4.3% for the non-PVC controls. Six mixers had a diurnal variation of more than 15% on at least one day compared with none among the other two groups. Twenty nine per cent of mixers complained of wheezing compared with 4% of non-mixers and none among non-PVC workers. These differences were significant. Forced expiratory volume in one second (FEV1) for the mixers was 10% below the predicted values whereas that of non-PVC workers was 2% below predicted values. The study indicates a significant acute airway constriction from occupational exposure to PVC dust. PMID:2025595

Laser beam-plasma plume interaction during laser welding

NASA Astrophysics Data System (ADS)

Hoffman, Jacek; Moscicki, Tomasz; Szymanski, Zygmunt

2003-10-01

Laser welding process is unstable because the keyhole wall performs oscillations which results in the oscillations of plasma plume over the keyhole mouth. The characteristic frequencies are equal to 0.5-4 kHz. Since plasma plume absorbs and refracts laser radiation, plasma oscillations modulate the laser beam before it reaches the workpiece. In this work temporary electron densities and temperatures are determined in the peaks of plasma bursts during welding with a continuous wave CO2 laser. It has been found that during strong bursts the plasma plume over the keyhole consists of metal vapour only, being not diluted by the shielding gas. As expected the values of electron density are about two times higher in peaks than their time-averaged values. Since the plasma absorption coefficient scales as ~N2e/T3/2 (for CO2 laser radiation) the results show that the power of the laser beam reaching the metal surface is modulated by the plasma plume oscillations. The attenuation factor equals 4-6% of the laser power but it is expected that it is doubled by the refraction effect. The results, together with the analysis of the colour pictures from streak camera, allow also interpretation of the dynamics of the plasma plume.

Gasification of oil palm empty fruit bunches: a characterization and kinetic study.

PubMed

Mohammed, M A A; Salmiaton, A; Wan Azlina, W A K G; Mohamad Amran, M S

2012-04-01

Empty fruit bunches (EFBs), a waste material from the palm oil industry, were subjected to pyrolysis and gasification. A high content of volatiles (>82%) increased the reactivity of EFBs, and more than 90% decomposed at 700°C; however, a high content of moisture (>50%) and oxygen (>45%) resulted in a low calorific value. Thermogravimetric analysis demonstrated that the higher the heating rate and the smaller the particle size, the higher the peak and final reaction temperatures. The least squares estimation for a first-order reaction model was used to study the degradation kinetics. The values of activation energy increased from 61.14 to 73.76 and from 40.06 to 47.99kJ/mol when the EFB particle size increased from 0.3 to 1.0mm for holocellulose and lignin degradation stages, respectively. The fuel characteristics of EFB are comparable to those of other biomasses and EFB can be considered a good candidate for gasification. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of a CoFeB layer on the anisotropic magnetoresistance of Ta/CoFeB/MgO/NiFe/MgO/CoFeB/Ta films

NASA Astrophysics Data System (ADS)

Li, Minghua; Shi, Hui; Dong, Yuegang; Ding, Lei; Han, Gang; Zhang, Yao; Liu, Ye; Yu, Guanghua

2017-10-01

The anisotropic magnetoresistance (AMR) and magnetic properties of NiFe films can be remarkably enhanced via CoFeB layer. In the case of an ultrathin NiFe film having a Ta/CoFeB/MgO/NiFe/MgO/CoFeB/Ta structure, the CoFeB/MgO layers suppressed the formation of magnetic dead layers and the interdiffusions and interface reactions between the NiFe and Ta layers. The AMR reached a maximum value of 3.56% at 450 °C. More importantly, a single NiFe (1 1 1) peak can be formed resulting in higher AMR values for films having CoFeB layer. This enhanced AMR also originated from the significant specular reflection of electrons owing to the crystalline MgO layer, together with the sharp interfaces with the NiFe layer. These factors together resulted in higher AMR and improved magnetic properties.

A study of ground motion attenuation in the Southern Great Basin, Nevada-California, using several techniques for estimates of Qs , log A 0, and coda Q

NASA Astrophysics Data System (ADS)

Rogers, A. M.; Harmsen, S. C.; Herrmann, R. B.; Meremonte, M. E.

1987-04-01

As a first step in the assessment of the earthquake hazard in the southern Great Basin of Nevada-California, this study evaluates the attenuation of peak vertical ground motions using a number of different regression models applied to unfiltered and band-pass-filtered ground motion data. These data are concentrated in the distance range 10-250 km. The regression models include parameters to account for geometric spreading, anelastic attenuation with a power law frequency dependence, source size, and station site effects. We find that the data are most consistent with an essentially frequency-independent Q and a geometric spreading coefficient less than 1.0. Regressions are also performed on vertical component peak amplitudes reexpressed as pseudo-Wood-Anderson peak amplitude estimates (PWA), permitting comparison with earlier work that used Wood-Anderson (WA) data from California. Both of these results show that Q values in this region are high relative to California, having values in the range 700-900 over the frequency band 1-10 Hz. Comparison of ML magnitudes from stations BRK and PAS for earthquakes in the southern Great Basin shows that these two stations report magnitudes with differences that are distance dependent. This bias suggests that the Richter log A0 curve appropriate to California is too steep for earthquakes occurring in southern Nevada, a result implicitly supporting our finding that Q values are higher than those in California. The PWA attenuation functions derived from our data also indicate that local magnitudes reported by California observatories for earthquakes in this region may be overestimated by as much as 0.8 magnitude units in some cases. Both of these results will have an effect on the assessment of the earthquake hazard in this region. The robustness of our regression technique to extract the correct geometric spreading coefficient n and anelastic attenuation Q is tested by applying the technique to simulated data computed with given n and Q values. Using a stochastic modeling technique, we generate suites of seismograms for the distance range 10-200 km and for both WA and short-period vertical component seismometers. Regressions on the peak amplitudes from these records show that our regression model extracts values of n and Q approximately equal to the input values for either low-Q California attenuation or high-Q southern Nevada attenuation. Regressions on stochastically modeled WA and PWA amplitudes also provides a method of evaluating differences in magnitudes from WA and PWA amplitudes due to recording instrument response characteristics alone. These results indicate a difference between MLWA and MLPWA equal to 0.15 magnitude units, which we term the residual instrument correction. In contrast to the peak amplitude results, coda Q determinations using the single scatterer theory indicate that Qc values are dependent on source type and are proportional to ƒp, where p = 0.8 to 1.0. This result suggests that a difference exists between attenuation mechanisms for direct waves and backscattered waves in this region.

Low-level processing for real-time image analysis

NASA Technical Reports Server (NTRS)

Eskenazi, R.; Wilf, J. M.

1979-01-01

A system that detects object outlines in television images in real time is described. A high-speed pipeline processor transforms the raw image into an edge map and a microprocessor, which is integrated into the system, clusters the edges, and represents them as chain codes. Image statistics, useful for higher level tasks such as pattern recognition, are computed by the microprocessor. Peak intensity and peak gradient values are extracted within a programmable window and are used for iris and focus control. The algorithms implemented in hardware and the pipeline processor architecture are described. The strategy for partitioning functions in the pipeline was chosen to make the implementation modular. The microprocessor interface allows flexible and adaptive control of the feature extraction process. The software algorithms for clustering edge segments, creating chain codes, and computing image statistics are also discussed. A strategy for real time image analysis that uses this system is given.

Observations of the 12.3 micron Mg I emission line during a major solar flare

NASA Technical Reports Server (NTRS)

Deming, Drake; Jennings, Donald E.; Osherovich, Vladimir; Wiedemann, Gunter; Hewagama, Tilak

1990-01-01

The extremely Zeeman-sensitive 12.32 micron Mg I solar emission line was observed during a 3B/X5.7 solar flare on October 24, 1989. When compared to postflare values, Mg I emission-line intensity in the penumbral flare ribbon was 20 percent greater at the peak of the flare in soft X-rays, and the 12 micron continuum intensity was 7 percent greater. The flare also excited the emission line in the umbra where it is normally absent. The umbral flare emission exhibits a Zeeman splitting 200 G less than the adjacent penumbra, suggesting that it is excited at higher altitude. The absolute penumbral magnetic field strength did not change by more than 100 G between the flare peak and postflare period. However, a change in the inclination of the field lines, probably related to the formation and development of the flare loop system, was seen.

Pulse compression in an electro-optic Q-switched diode-pumped YVO4/Nd:YVO4 laser with a Cr4+:YAG saturable absorber.

PubMed

Li, Tao; Zhao, Shengzhi; Zhuo, Zhuang; Yang, Kejian; Li, Guiqiu; Li, Dechun

2009-04-20

A diode end-pumped doubly Q-switched YVO4/Nd:YVO4 laser has been realized for the first time to our knowledge by using both an electro-optic (EO) modulator and a Cr4):YAG saturable absorber. A 3.8 ns pulse width is generated by this laser under a pump power of 15 W at 2 kHz, which is obviously compressed in comparison with that of 8.8 ns from a single actively EO Q-switched laser. Under the same conditions, peak power values of 174.7 and 93 kW are also obtained. A coupled equation is given to theoretically analyze the experimental data. The experimental and theoretical results show that the doubly Q-switched laser has the advantages of a shorter pulse width and higher pulse peak power in contrast with a singly Q-switched laser.

Resonant photodetector for cavity- and phase-locking of squeezed state generation.

PubMed

Chen, Chaoyong; Li, Zhixiu; Jin, Xiaoli; Zheng, Yaohui

2016-10-01

Based on the requirement of squeezed state generation, we build the phase relationship between two electronic local oscillators for the cavity- and phase-locking branches, and a 2-way 90° power splitter is adopted to satisfy the phase relationship simultaneously, which greatly simplifies the experimental setup and adjusting process. A LC parallel resonant circuit, which is composed by the inherent capacitance of a photodiode and an extra inductor, is adopted in the resonant photodetector to improve the gain factor at the expected frequency. The gain of the resonant photodetector is about 30 dB higher than that of the broadband photodetector at the resonant frequency. The peak-to-peak value of the error signal for cavity-locking (phase-locking) with the resonant photodetector is 240 (260) times of that with the broadband photodetector, which can improve the locking performance on the premise of not affecting the squeezing degree.

Identification of atmospheric boundary layer thickness using doppler radar datas and WRF - ARW model in Merauke

NASA Astrophysics Data System (ADS)

Putri, R. J. A.; Setyawan, T.

2017-01-01

In the synoptic scale, one of the important meteorological parameter is the atmospheric boundary layer. Aside from being a supporter of the parameters in weather and climate models, knowing the thickness of the layer of the atmosphere can help identify aerosols and the strength of the vertical mixing of pollutants in it. The vertical wind profile data from C-band Doppler radar Mopah-Merauke which is operated by BMKG through Mopah-Merauke Meteorological Station can be used to identify the peak of Atmospheric Boundaryu Layer (ABL). ABL peak marked by increasing wind shear over the layer blending. Samples in January 2015 as a representative in the wet and in July 2015 as the representation of a dry month, shows that ABL heights using WRF models show that in July (sunny weather) ABL height values higher than in January (cloudy)

Response measurements for two building structures excited by noise from a large horizontal axis wind turbine generator

NASA Technical Reports Server (NTRS)

Hubbard, H. H.; Shepherd, K. P.

1984-01-01

Window and wall acceleration measurements and interior noise measurements ere made for two different building structures during excitation by noise from the WTS-4 horizontal axis wind turbine generator operating in a normal power generation mode. With turbine noise input pulses resulted in acceleration pulses for the wall and window elements of the two tests buildings. Response spectra suggest that natural vibration modes of the structures are excited. Responses of a house trailer were substantially greater than those for a building of sturdier construction. Peak acceleration values correlate well with similar data for houses excited by flyover noise from commercial and military airplanes and helicopters, and sonic booms from supersonic aircraft. Interior noise spectra have peaks at frequencies corresponding to structural vibration modes and room standing waves; and the levels for particular frequencies and locations can be higher than the outside levels.

A study of spectrum fatigue crack propagation in two aluminum alloys. 1: Spectrum simplification

NASA Technical Reports Server (NTRS)

Telesman, J.; Antolovich, S. D.

1985-01-01

The fatigue crack propagation behavior of two commercial Al alloys was studied using spectrum loading conditions characteristics of those encountered at critical locations in high performance fighter aircraft. A tension dominated (TD) and tension compression (TC) spectrum were employed for each alloy. Using a mechanics-based analysis, it was suggested that negative loads could be eliminated for the TC spectrum for low to intermediate maximum stress intensities. The suggestion was verified by subsequent testing. Using fractographic evidence, it was suggested that a further similification in the spectra could be accomplished by eliminating low and intermediate peak load points resulting in near or below threshold maximum peak stress intensity values. It is concluded that load interactions become more important at higher stress intensities and more plasticity at the crack tip. These results suggest that a combined mechanics/fractographic mechanisms approach can be used to simplify other complex spectra.

Intraabdominal pressure in women during CrossFit exercises and the effect of age and parity.

PubMed

Gephart, Laura Faye; Doersch, Karen M; Reyes, Michelle; Kuehl, Thomas J; Danford, Jill M

2018-07-01

To determine intraabdominal pressure (IAP) in women during CrossFit and to determine whether parity, age, or CrossFit experience affects IAP during CrossFit exercises, we evaluated 10 women: 5 experienced and active CrossFitters and 5 who were not regularly engaged in CrossFit. A Laborie urodynamics abdominal pressure probe with the Goby wireless system measured IAP during 10 repetitions of 13 different CrossFit exercises. Women had a mean age of 36 years. A significant difference was found between mean peak IAP of the 5 parous vs the 5 nulliparous women ( P = 0.009). Experience with CrossFit did not affect mean peak IAP achieved with exercise. In some exercises, there was a significant change in IAP as participants progressed through repetitions ( P = 0.003 for back squats and 0.04 for sit-ups). Participants achieved IAP values that were markedly higher than those previously published.

Point-contact spectroscopy of the iron chalcogenide superconductors: interplay between multiband superconductivity and magnetism

NASA Astrophysics Data System (ADS)

Park, Wan Kyu; Hunt, C. R.; Arham, H. Z.; Lu, X.; Greene, L. H.; Xu, Z. J.; Wen, J. S.; Lin, Z. W.; Li, Q.; Gu, G.

2010-03-01

We report point-contact conductance measurements on the iron chalcogenide superconductors, Fe1+yTe1-xSex. The excess Fe atoms are known to occupy the interstitial sites in the Te-Se plane, affecting the superconductivity as well as the magnetism in this family. For a compound having nominal values of y=0 and x=0.45, a single superconducting transition is observed at 14.2 K. In the superconducting state, BTK-like double peak structures due to Andreev reflection are observed. However, the peak position of different point contacts falls to a wide voltage range, 1.5 -- 4 mV. Additional multiple humps are sometimes observed in a much higher bias voltage range, 8 -- 15 mV. Most strikingly, conductance enhancement persists well above Tc. We will present possible interpretations of these experimental observations in terms of multiband superconductivity and the interplay between superconductivity and magnetism.

Effect of selenium deficiency on the thermoelectric properties of n -type In 4 Se 3 - x compounds

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

Zhu, G. H.; Lan, Y. C.; Wang, H.

2011-03-01

Thermoelectric properties of dense bulk polycrystalline In 4 Se 3 - x ( x = 0, 0.25, 0.5, 0.65, and 0.8) compounds are investigated. A peak dimensionless thermoelectric figure of merit ( ZT ) of about 1 is achieved for x = 0.65 and 0.8. The peak ZT is about 50% higher than the previously reported highest value for polycrystalline In 4 Se 3 - x compounds. Our In 4 Se 3 - x samples were prepared by ball milling and hot pressing. We show that it is possible to effectively control the electrical conductivity and thermal conductivity by controllingmore » selenium (Se) deficiency x . The ZT enhancement is mainly attributed to the thermal conductivity reduction due to the increased phonon scattering by Se deficiency, defects, and nanoscale inclusions in the ball-milled and hot-pressed dense bulk In 4 Se 3 - x samples.« less

Effect of selenium deficiency on the thermoelectric properties of n-type In 4Se 3-x compounds

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

Zhu, G H; Lan, Y C; Wang, H

2011-03-04

Thermoelectric properties of dense bulk polycrystalline In 4Se 3-x (x = 0, 0.25, 0.5, 0.65, and 0.8) compounds are investigated. A peak dimensionless thermoelectric figure of merit (ZT) of about 1 is achieved for x = 0.65 and 0.8. The peak ZT is about 50% higher than the previously reported highest value for polycrystalline In 4Se 3-x} compounds. Our In 4Se 3-x samples were prepared by ball milling and hot pressing. We show that it is possible to effectively control the electrical conductivity and thermal conductivity by controlling selenium (Se) deficiency x. The ZT enhancement is mainly attributed to themore » thermal conductivity reduction due to the increased phonon scattering by Se deficiency, defects, and nanoscale inclusions in the ball-milled and hot-pressed dense bulk In 4Se 3-x samples.« less

MRI Proton Density Fat Fraction Is Robust Across the Biologically Plausible Range of Triglyceride Spectra in Adults With Nonalcoholic Steatohepatitis

PubMed Central

Hong, Cheng William; Mamidipalli, Adrija; Hooker, Jonathan C.; Hamilton, Gavin; Wolfson, Tanya; Chen, Dennis H.; Dehkordy, Soudabeh Fazeli; Middleton, Michael S.; Reeder, Scott B.; Loomba, Rohit; Sirlin, Claude B.

2017-01-01

Background Proton density fat fraction (PDFF) estimation requires spectral modeling of the hepatic triglyceride (TG) signal. Deviations in the TG spectrum may occur, leading to bias in PDFF quantification. Purpose To investigate the effects of varying six-peak TG spectral models on PDFF estimation bias. Study Type Retrospective secondary analysis of prospectively acquired clinical research data. Population Forty-four adults with biopsy-confirmed nonalcoholic steatohepatitis. Field Strength/Sequence Confounder-corrected chemical-shift-encoded 3T MRI (using a 2D multiecho gradient-recalled echo technique with magnitude reconstruction) and MR spectroscopy. Assessment In each patient, 61 pairs of colocalized MRI-PDFF and MRS-PDFF values were estimated: one pair used the standard six-peak spectral model, the other 60 were six-peak variants calculated by adjusting spectral model parameters over their biologically plausible ranges. MRI-PDFF values calculated using each variant model and the standard model were compared, and the agreement between MRI-PDFF and MRS-PDFF was assessed. Statistical Tests MRS-PDFF and MRI-PDFF were summarized descriptively. Bland–Altman (BA) analyses were performed between PDFF values calculated using each variant model and the standard model. Linear regressions were performed between BA biases and mean PDFF values for each variant model, and between MRI-PDFF and MRS-PDFF. Results Using the standard model, mean MRS-PDFF of the study population was 17.9±8.0% (range: 4.1–34.3%). The difference between the highest and lowest mean variant MRI-PDFF values was 1.5%. Relative to the standard model, the model with the greatest absolute BA bias overestimated PDFF by 1.2%. Bias increased with increasing PDFF (P < 0.0001 for 59 of the 60 variant models). MRI-PDFF and MRS-PDFF agreed closely for all variant models (R2=0.980, P < 0.0001). Data Conclusion Over a wide range of hepatic fat content, PDFF estimation is robust across the biologically plausible range of TG spectra. Although absolute estimation bias increased with higher PDFF, its magnitude was small and unlikely to be clinically meaningful. Level of Evidence 3 Technical Efficacy Stage 2 PMID:28851124

Sensitivity to detect small coronary artery calcium lesions with varying slice thickness using electron beam tomography.

PubMed

Mao, Songshou; Child, Janis; Carson, Sivi; Liu, Steve C K; Oudiz, Ronald J; Budoff, Matthew J

2003-03-01

To estimate the sensitivity to find small coronary artery calcium lesions with use of different slice widths with electron beam tomography. Two studies were performed. Study 1 utilized double scanning of a stationary cork phantom with three different slice thickness (1.5, 3, and 6 mm). Fifty different calcific lesions (all <20 mm2 in area) fitted in 10 cork coronary arteries were utilized. The calcium foci area, peak value and score were measured and compared. In group 2, 30 patients underwent coronary artery calcium (CAC) screen studies. Each patient was scanned with both 3-mm and 6-mm scan widths in a same study time. Lesions with < 20 mm2 of area of CAC were measured on both 3-mm and 6-mm images. The mean and peak Hounsfield unit measure, and Agatston score were compared between both images. In the cork study, the sensitivity to detect small calcium foci were 96% (48/50), 82% (41/50), and 34% (17/50) in images with 1.5-, 3-, and 6-mm slice thickness, respectively. There is a smaller value in mass, and calcium volume in 6-mm images than 1.5-mm and 3-mm images ( P< 0.001). There was no significant difference between the true value and measured value from 1.5-mm and 3-mm images. In the human study, 18 (30%) of 60 CAC lesions with an area < 20 mm2 defined on 3 mm images were not visible on 6-mm images. Sensitivity of small lesions (P< 5 mm2) was 48% using 6-mm slices. There was a smaller value in CAC area, mean and peak Hounsfield units and score measured from 6-mm images, as compared with 3 mm slices ( P< 0.05). Thinner slice imaging has a higher sensitivity to detect small calcium focus. There was no significant change in score between 3 mm and 1.5 mm on the cork phantom study. However, the use of 6-mm slices should be discouraged, as this protocol both underestimates calcific mass and misses a significant number of calcific lesions in both a phantom and human study.

Method and apparatus for electrospark deposition

DOEpatents

Bailey, Jeffrey A.; Johnson, Roger N.; Park, Walter R.; Munley, John T.

2004-12-28

A method and apparatus for controlling electrospark deposition (ESD) comprises using electrical variable waveforms from the ESD process as a feedback parameter. The method comprises measuring a plurality of peak amplitudes from a series of electrical energy pulses delivered to an electrode tip. The maximum peak value from among the plurality of peak amplitudes correlates to the contact force between the electrode tip and a workpiece. The method further comprises comparing the maximum peak value to a set point to determine an offset and optimizing the contact force according to the value of the offset. The apparatus comprises an electrode tip connected to an electrical energy wave generator and an electrical signal sensor, which connects to a high-speed data acquisition card. An actuator provides relative motion between the electrode tip and a workpiece by receiving a feedback drive signal from a processor that is operably connected to the actuator and the high-speed data acquisition card.

Effect of Rapid Thermal Processing on Light-Induced Degradation of Carrier Lifetime in Czochralski p-Type Silicon Bare Wafers

NASA Astrophysics Data System (ADS)

Kouhlane, Y.; Bouhafs, D.; Khelifati, N.; Belhousse, S.; Menari, H.; Guenda, A.; Khelfane, A.

2016-11-01

The electrical properties of Czochralski silicon (Cz-Si) p-type boron-doped bare wafers have been investigated after rapid thermal processing (RTP) with different peak temperatures. Treated wafers were exposed to light for various illumination times, and the effective carrier lifetime ( τ eff) measured using the quasi-steady-state photoconductance (QSSPC) technique. τ eff values dropped after prolonged illumination exposure due to light-induced degradation (LID) related to electrical activation of boron-oxygen (BO) complexes, except in the sample treated with peak temperature of 785°C, for which the τ eff degradation was less pronounced. Also, a reduction was observed when using the 830°C peak temperature, an effect that was enhanced by alteration of the wafer morphology (roughness). Furthermore, the electrical resistivity presented good stability under light exposure as a function of temperature compared with reference wafers. Additionally, the optical absorption edge shifted to higher wavelength, leading to increased free-carrier absorption by treated wafers. Moreover, a theoretical model is used to understand the lifetime degradation and regeneration behavior as a function of illumination time. We conclude that RTP plays an important role in carrier lifetime regeneration for Cz-Si wafers via modification of optoelectronic and structural properties. The balance between an optimized RTP cycle and the rest of the solar cell elaboration process can overcome the negative effect of LID and contribute to achievement of higher solar cell efficiency and module performance.

Nitric Acid Phase Partitioning and Cycling in the New England Coastal Atmosphere

NASA Astrophysics Data System (ADS)

Fischer, E.; Keene, W.; Maben, J.; Pszenny, A.; Smith, A.; Talbot, R.

2005-12-01

During summer 2004, soluble gases were continuously sampled over 2-hour intervals and size-resolved aerosols were sampled over discrete daytime (~ 15 hr) or nighttime (~ 9 hr) intervals at Appledore Island, ME as part of the International Consortium for Atmospheric Research on Transport and Transformations (ICARTT) field program. Particulate NO3- and gaseous HNO3 concentrations were examined as a function of transport sector and dry deposition fluxes were estimated. HNO3 concentrations varied widely on the time scale of hours; however, all sampling days were characterized by a distinct minimum in the early morning. The daily peak normally occurred in the early afternoon, and was followed by a secondary peak at about 2200. The maximum and median concentrations of HNO3, were 337 and 22.5 nmol m-3 respectively. Aerosol NO3- exhibited a bimodal size distribution with a primary peak associated with sea-salt Na+ at ~4 μm and a secondary sub-μm peak. The median NO3- concentrations of sub and super-μm aerosol fractions were 3.3 and 7.7 nmol m-3 respectively. HNO3 concentrations (median value = 57 nmol m-3) were measured during westerly flow regimes, while super-μm aerosol peaked during southwesterly flow regimes. Although median total nitrate (HNO3 + NO3-)concentrations were higher under westerly flow, higher median dry deposition rates for total nitrate were calculated for southwesterly flow. Both westerly and southwesterly transport regimes carried polluted continental air to the site, but sea-salt concentrations were a factor of 3 higher during southwesterly flow which shifted the phase partitioning toward particulate NO3-. Consequently, under westerly flow, the calculated HNO3 deposition flux was ~3 times greater than the associated aerosol NO3- flux, while for southwesterly flow, the fluxes from the two phases were comparable. The median dry deposition fluxes for aerosol NO3- and volatile HNO3 were 5.6 and 8.2 μmol m-2 d-1. Large particles dominated the aerosol dry deposition, because of both higher concentrations and deposition velocities. This is consistent with previous work suggesting that the mixing of polluted continental and marine air may enhance dry deposition of total nitrate to coastal ecosystems. Displacement of HCl from sea-salt aerosol via incorporation of HNO3 helped to sustain high mixing ratios of HCl (up to 255 nmol m-3) and significant production of atomic Cl via HCl + OH during the daytime, thereby altering the oxidant regime relative to the upwind continent.

Review of the clinical pharmacokinetics of artesunate and its active metabolite dihydroartemisinin following intravenous, intramuscular, oral or rectal administration

PubMed Central

2011-01-01

Artesunate (AS) is a clinically versatile artemisinin derivative utilized for the treatment of mild to severe malaria infection. Given the therapeutic significance of AS and the necessity of appropriate AS dosing, substantial research has been performed investigating the pharmacokinetics of AS and its active metabolite dihydroartemisinin (DHA). In this article, a comprehensive review is presented of AS clinical pharmacokinetics following administration of AS by the intravenous (IV), intramuscular (IM), oral or rectal routes. Intravenous AS is associated with high initial AS concentrations which subsequently decline rapidly, with typical AS half-life estimates of less than 15 minutes. AS clearance and volume estimates average 2 - 3 L/kg/hr and 0.1 - 0.3 L/kg, respectively. DHA concentrations peak within 25 minutes post-dose, and DHA is eliminated with a half-life of 30 - 60 minutes. DHA clearance and volume average between 0.5 - 1.5 L/kg/hr and 0.5 - 1.0 L/kg, respectively. Compared to IV administration, IM administration produces lower peaks, longer half-life values, and higher volumes of distribution for AS, as well as delayed peaks for DHA; other parameters are generally similar due to the high bioavailability, assessed by exposure to DHA, associated with IM AS administration (> 86%). Similarly high bioavailability of DHA (> 80%) is associated with oral administration. Following oral AS, peak AS concentrations (Cmax) are achieved within one hour, and AS is eliminated with a half-life of 20 - 45 minutes. DHA Cmax values are observed within two hours post-dose; DHA half-life values average 0.5 - 1.5 hours. AUC values reported for AS are often substantially lower than those reported for DHA following oral AS administration. Rectal AS administration yields pharmacokinetic results similar to those obtained from oral administration, with the exceptions of delayed AS Cmax and longer AS half-life. Drug interaction studies conducted with oral AS suggest that AS does not appreciably alter the pharmacokinetics of atovaquone/proguanil, chlorproguanil/dapsone, or sulphadoxine/pyrimethamine, and mefloquine and pyronaridine do not alter the pharmacokinetics of DHA. Finally, there is evidence suggesting that the pharmacokinetics of AS and/or DHA following AS administration may be altered by pregnancy and by acute malaria infection, but further investigation would be required to define those alterations precisely. PMID:21914160

Substorm and magnetosphere characteristic scales inferred from the SuperMAG auroral electrojet indices

NASA Astrophysics Data System (ADS)

Newell, P. T.; Gjerloev, J. W.

2011-12-01

A generalization of the traditional 12-station auroral electrojet (AE) index to include more than 100 magnetometer stations, SME, is an excellent predictor of global auroral power (AP), even at high cadence (1 min). We use this index, and a database of more than 53,000 substorms derived from it, covering 1980-2009, to investigate time and energy scales in the magnetosphere, during substorms and otherwise. We find, contrary to common opinion, that substorms do not have a preferred recurrence rate but instead have two distinct dynamic regimes, each following a power law. The number of substorms recurring after a time Δt, N(Δt), varies as Δt-1.19 for short times (<80 min) and as Δt-1.76 for longer times (>3 hours). Other evidence also shows these distinct regimes for the magnetosphere, including a break in the power law spectra for SME at about 3 hours. The time between two consecutive substorms is only weakly correlated (r = 0.18 for isolated and r = 0.06 for recurrent) with the time until the next, suggesting quasiperiodicity is not common. However, substorms do have a preferred size, with the typical peak SME magnitude reaching 400-600 nT, but with a mean of 656 nT, corresponding to a bit less than 40 GW AP. More surprisingly, another characteristic scale exists in the magnetosphere, namely, a peak in the SME distribution around 61 nT, corresponding to about 5 GW precipitating AP. The dominant form of auroral precipitation is diffuse aurora; thus, these values are properties of the magnetotail thermal electron distribution. The characteristic 5 GW value specifically represents a preferred minimum below which the magnetotail rarely drops. The magnetotail experiences continuous loss by precipitation, so the existence of a preferred minimum implies driving that rarely disappears altogether. Finally, the distribution of SME values across all times, in accordance with earlier work on AE, is best fit by the sum of two distributions, each normal in log(SME). The lower distribution (with a 40% weighting) corresponds to the characteristic quiet peak, while the higher value distribution (60% weighting) is an average over the characteristic substorm peak and the subsequent prolonged recovery.

ENSO variability of Quelccaya Ice Cap δ18O driven by monsoon control of vapor isotope ratios

NASA Astrophysics Data System (ADS)

Hurley, J. V.; Vuille, M. F.; Hardy, D. R.

2016-12-01

The δ18O from the Quelccaya Ice Cap (QIC), Peru corresponds with and has been used to reconstruct Nino region SSTs but the physical mechanisms that tie ENSO-variable equatorial Pacific SSTs to snow δ18O at 5680 m in the Andes have not been fully described. We use a proxy system forward model to simulate and explore ENSO variable snow δ18O at the QIC, which is observed and accurately simulated with our model to be respectively higher and lower than average during El Nino and La Nina. We then explore the relative roles of ENSO-forcing on components of the forward model: the seasonality of snowfall at the QIC, vapor initial δ18O values, and temperature. The local hydrologic cycle is characterized by earlier onset and reduced duration of peak snowfall during El Nino, and more snow accumulation during La Nina. When we isolate the influence of the local hydrologic cycle in the forward model, El Nino and La Nina snowfall seasonalities yield respectively higher and lower snow δ18O values, compared with the control simulation. The South American summer monsoon (SASM) is characterized by enhanced convection over the Amazon during La Nina and as a consequence, lower vapor δ18O values over the western Amazon Basin. When we isolate the influence of the vapor initial delta-value in the forward model, higher initial delta-values during El Nino yield higher snow δ18O at the QIC. The seasonality of temeratures over the western Amazon Basin and near Quelccaya is amplified during El Nino when there are higher and lower temperatures respectively during austral summer and winter. When we isolate the temperature influence in the forward model, the warmer summer El Nino conditions require a more humid initial vapor and result in lower snow δ18O values. Most (more than two-thirds) of the ENSO variability in QIC δ18O can be accounted for by SASM activity and its influence on the vapor initial delta-value.

[Study on Different Parts of Wild and Cultivated Gentiana Rigescens with Fourier Transform Infrared Spectroscopy].

PubMed

Shen, Yun-xia; Zhao, Yan-li; Zhang, Ji; Zuo, Zhi-tian; Wang, Yuan-zhong; Zhang, Qing-zhi

2016-03-01

The application of traditional Chinese medicine (TCM) and their preparations have a long history. With the deepening of the research, the market demand is increasing. However, wild resources are so limited that it can not meet the needs of the market. The development of wild and cultivated samples and research on accumulation dynamics of chemical component are of great significance. In order to compare composition difference of different parts (root, stem, and leaf) of wild and cultivated G. rigescens, Fourier infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate. The second derivative spectra of 60 samples and the rate of affinity (the match values) were measured automatically using the appropriate software (Omnic 8.0). The results showed that the various parts of wild and cultivated G. rigescens. were high similar the peaks at 1732, 1 643, 1 613, 1 510, 1 417, 1 366, 1 322, 1 070 cm(-1) were the characteristic peak of esters, terpenoids and saccharides, respectively. Moreover, the shape and peak intensity were more distinct in the second derivative spectrum of samples. In the second derivative spectrum range of 1 800-600 cm(-1), the fingerprint characteristic peak of samples and gentiopicroside standards were 1 679, 1 613, 1 466, 1 272, 1 204, 1 103, 1 074, 985, 935 cm(-1). The characteristic peak intensity of gentiopicroside of roots of wild and cultivated samples at 1 613 cm(-1) (C-C) was higher than stems and leaves which indicated the higher content of gentiopicroside in root than in stem and leaves. Stems of wild samples at 1 521, 1 462 and 1 452 cm(-1) are the skeletal vibration peak of benzene ring of lignin, and the stem of cultivated sample have stronger peak than other samples which showed that rich lignin in stems. The iInfrared spectrum of samples were similar with the average spectral of root of wild samples, and significant difference was found for the correlation between second derivative spectrum of samples and average spectral of wild samples root, and the sequence of similarity was root > stem > leaf. Therefore, FTIR combined with second derivative spectra was an express and comprehensive approach to analyze and evaluate in the imperceptible differences among different parts of wild and cultivated of G. rigescens.

Synthesis, morphology, optical and photocatalytic performance of nanostructured β-Ga{sub 2}O{sub 3}

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

Girija, K.; DRDO – BU CLS, Bharathiar University, Coimbatore 641046; Thirumalairajan, S.

2013-06-01

Highlights: ► Nanostructures of β-Ga{sub 2}O{sub 3} were prepared using facile reflux condensation process. ► The pH of the reaction mixture shows evident influence on the size and shape of the nanostructures formed. ► The nanostructures exhibited good photocatalytic activity toward Rhodamine B and was found to be superior for higher pH value. - Abstract: Fine powders of β-Ga{sub 2}O{sub 3} nanostructures were prepared via low temperature reflux condensation method by varying the pH value without using any surfactant. The pH value of reaction mixture had great influence on the morphology of final products. High crystalline single phase β-Ga{sub 2}O{submore » 3} nanostructures were obtained by thermal treatment at 900 °C which was confirmed by X-ray diffraction and Raman spectroscopy. The morphological analysis revealed rod like nanostructures at lower and higher pH values of 6 and 10, while spindle like structures were obtained at pH = 8. The phase purity and presence of vibrational bands were identified using Fourier transform infrared spectroscopy. The optical absorbance spectrum showed intense absorption features in the UV spectral region. A broad blue emission peak centered at 441 nm due to donor–acceptor gallium–oxygen vacancy pair recombination appeared. The photocatalytic activity toward Rhodamine B under visible light irradiation was higher for nanorods at pH 10.« less

Hyperinsulinemia in polycystic ovary disease.

PubMed

Arthur, L S; Selvakumar, R; Seshadri, M S; Seshadri, L

1999-09-01

To evaluate the prevalence of hyperinsulinemia and insulin resistance in women with polycystic ovary disease (PCOD). Forty women with clinical and biochemical evidence of PCOD and 20 with regular menstrual cycles were studied prospectively. All women underwent a three-hour oral glucose tolerance test following a 100-g glucose load. Plasma sugar and insulin levels were measured. The one-, two- and three-hour insulin values were significantly higher in women with PCOD. The sum insulin, cumulative insulin, peak insulin and area under the insulin response curve were similarly higher in women with PCOD than in the controls. The presence of hirsutism was more often associated with hyperinsulinemia and insulin resistance, but body mass index and menstrual irregularity were not. Hyperinsulinemia and insulin resistance seem to be commonly associated with PCOD.

X-ray photoelectron spectroscopy and atomic force microscopy characterization of the effects of etching Zn xCd 1- xTe surfaces

NASA Astrophysics Data System (ADS)

George, M. A.; Azoulay, M.; Jayatirtha, H. N.; Burger, A.; Collins, W. E.; Silberman, E.

1993-10-01

X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) was used for the first time to characterize the chemical composition of modified surfaces of Zn xCd 1- xTe single crystals. These surface treatments were selected for their relevance to device preparation procedures. The XPS peaks indicated an increase of the tellurium and a depletion of the cadmium concentrations upon etching in bromine methanol solution. AFM revealed the formation of pronounced Te inclusions. Higher x values correlated with a decrease in residual bromine left on the surface, while cut and polished samples had higher oxide concentrations and increased bromination of the surface than cleaved samples.

Statistical Characteristic of Global Tropical Cyclone Looping Motion

NASA Astrophysics Data System (ADS)

Shen, W.; Song, J.; Wang, Y.

2016-12-01

Statistical characteristic of looping motion of tropical cyclones (TCs) in the Western North Pacific (WPAC), North Atlantic (NATL), Eastern North Pacific (EPAC), Northern Indian Ocean (NIO), Southern Indian Ocean (SIO) and South Pacific (SPAC) basins are investigated by using IBTrACS archive maintained by NOAA. From global perspective, about ten percent TCs experience a looping motion in the above six basins. The southern hemisphere (SH) including SIO and SPAC basins have higher looping percentage than the northern hemisphere (NH), while the EPAC basin has the least looping percentage. The interannual variation of the number of looping TCs are significantly correlated with that of total TCs in the NATL, SIO and SPAC basins, while there are no correlations between the EPAC and NIO basins. The numbers of looping TCs have a higher percentage in the early and late cyclone season in the NH rather than the peak period of cyclone season, while the SIO and SPAC basins have the higher looping percentage in the early and late cyclone season, respectively. The looping motion of TCs mainly concentrates on the scale of tropical depression to category 2 and has its peak value on the scale of tropical storm. The looping motion appears more frequently and has a higher percentage at the pre-mature stage than the post-mature stage of TCs in most basins except EPAC. Comparing the intensity and intensity variation caused by the looping motion, the weaker TCs tend to intensify after looping, while the more intense ones weaken.

Seasonal and vertical distributional patterns of siphonophores and medusae in the Chiloé Interior Sea, Chile

NASA Astrophysics Data System (ADS)

Palma, Sergio; Silva, Nelson; Cristina Retamal, María; Castro, Leonardo

2011-03-01

The horizontal and vertical distribution of jellyfish was assessed in the Chiloé Inland sea, in the northern area of the Chilean Patagonia. A total of 41 species of cnidarians (8 siphonophores, 31 hydromedusae, 2 scyphomedusae) were collected. Eleven jellyfish species were recorded for the first time in the area. Species richness was higher in spring than in winter (37 vs. 25 species, respectively). Species such as Muggiaea atlantica, Solmundella bitentaculata, and Clytia simplex were extremely abundant in spring. The total abundance (408,157 ind 1000 m -3) was 18 times higher in spring than in winter (22,406 ind 1000 m -3). The horizontal distribution of the most abundant species (four in winter, five in spring) showed decreasing abundances in the north-south direction in winter and spring. Peak abundances occurred in the northern microbasins (Reloncaví Fjord, Reloncaví and Ancud gulfs), where the water column stability, phytoplankton and zooplankton abundance were higher, compared with the southern microbasins (Corcovado Gulf, Boca del Guafo). During the spring higher jellyfish abundance season, the vertical distribution of the dominant species (except M. atlantica) showed peak values at mid-depth (30-50 m) and in the deepest sampled layer (50-200 m). This vertical distribution pattern reduced seaward transport in the shallowest layer through estuarine circulation and also limited mortality by predation in the more illuminated shallow layers. Thus, jellyfish were able to remain in the interior waters during the season of maximum biological production.

Evaluation of peak force of a manually operated chiropractic adjusting instrument with an adapter for use in animals.

PubMed

Duarte, Felipe Coutinho Kullmann; Kolberg, Carolina; Barros, Rodrigo R; Silva, Vivian G A; Gehlen, Günter; Vassoler, Jakson M; Partata, Wania A

2014-05-01

This study was designed to assess the peak force of a manually operated chiropractic adjusting instrument, the Activator Adjusting Instrument 4 (AAI 4), with an adapter for use in animals, which has a 3- to 4-fold smaller contact surface area than the original rubber tip. Peak force was determined by thrusting the AAI 4 with the adapter or the original rubber tip onto a load cell. First, the AAI 4 was applied perpendicularly by a doctor of chiropractic onto the load cell. Then, the AAI 4 was fixed in a rigid framework and applied to the load cell. This procedure was done to prevent any load on the load cell before the thrust impulse. In 2 situations, trials were performed with the AAI 4 at all force settings (settings I, II, III, and IV, minimum to maximum, respectively). A total of 50000 samples per second over a period of 3 seconds were collected. In 2 experimental protocols, the use of the adapter in the AAI 4 increased the peak force only with setting I. The new value was around 80% of the maximum value found for the AAI 4. Nevertheless, the peak force values of the AAI 4 with the adapter and with the original rubber tip in setting IV were similar. The adapter effectively determines the maximum peak force value at force setting I of AAI 4. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.

PubMed

Rubio-Arias, Jacobo Ángel; Ramos-Campo, Domingo Jesús; Peña Amaro, José; Esteban, Paula; Mendizábal, Susana; Jiménez, José Fernando

2017-11-01

The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Track and Field Practice and Bone Outcomes among Adolescents: A Pilot Study (ABCD-Growth Study).

PubMed

Faustino-da-Silva, Yuri da Silva Ventura; Agostinete, Ricardo Ribeiro; Werneck, André Oliveira; Maillane-Vanegas, Santiago; Lynch, Kyle Robinson; Exupério, Isabella Neto; Ito, Igor Hideki; Fernandes, Romulo Araújo

2018-02-01

Osteoporosis is considered a public health problem with high worldwide prevalence. One approach to prevention is through the promotion of physical activity, especially exercise, during adolescence. This study compared bone variables in different body segments in adolescents according to participation in track and field. The study included 34 adolescents (22 boys), of whom 17 were track and field athletes and 17 were control subjects. Bone mineral density (BMD, g/cm 2 ) and bone mineral content (BMC, g) were analyzed using dual energy X-ray absorptiometry (total body stratified by body segments). Peak height velocity was used to estimate somatic maturation. Athletes had higher BMD ( P =0.003) and BMC ( P =0.011) values in the lower limbs and higher whole body BMD ( P =0.025) than the control group. However, when adjusted for confounding factors, the difference was not maintained. The groups had similar lean soft tissue values ( P =0.094). Training overload was positively correlated with BMD in the upper limbs (r=0.504; 95% confidence interval, 0.031-0.793). Although track and field athletes had higher BMD and BMC values in the lower limbs, these differences were not significant when adjusted for confounding factors. Track and field participation in adolescence appears to influence BMD and BMC in lower limbs, and fat-free mass seems to mediate this effect. Also, higher training loads were found to be positive for bone health in upper limbs.

Track and Field Practice and Bone Outcomes among Adolescents: A Pilot Study (ABCD-Growth Study)

PubMed Central

Faustino-da-Silva, Yuri da Silva Ventura; Werneck, André Oliveira; Maillane-Vanegas, Santiago; Lynch, Kyle Robinson; Exupério, Isabella Neto; Ito, Igor Hideki; Fernandes, Romulo Araújo

2018-01-01

Background Osteoporosis is considered a public health problem with high worldwide prevalence. One approach to prevention is through the promotion of physical activity, especially exercise, during adolescence. Methods This study compared bone variables in different body segments in adolescents according to participation in track and field. The study included 34 adolescents (22 boys), of whom 17 were track and field athletes and 17 were control subjects. Bone mineral density (BMD, g/cm2) and bone mineral content (BMC, g) were analyzed using dual energy X-ray absorptiometry (total body stratified by body segments). Peak height velocity was used to estimate somatic maturation. Results Athletes had higher BMD (P=0.003) and BMC (P=0.011) values in the lower limbs and higher whole body BMD (P=0.025) than the control group. However, when adjusted for confounding factors, the difference was not maintained. The groups had similar lean soft tissue values (P=0.094). Training overload was positively correlated with BMD in the upper limbs (r=0.504; 95% confidence interval, 0.031-0.793). Although track and field athletes had higher BMD and BMC values in the lower limbs, these differences were not significant when adjusted for confounding factors. Conclusions Track and field participation in adolescence appears to influence BMD and BMC in lower limbs, and fat-free mass seems to mediate this effect. Also, higher training loads were found to be positive for bone health in upper limbs. PMID:29564304

Nonlinear dynamic response of a uni-directional model for the tile/pad space shuttle thermal protection system

NASA Technical Reports Server (NTRS)

Housner, J. M.; Edighoffer, H. H.; Park, K. C.

1980-01-01

A unidirectional analysis of the nonlinear dynamic behavior of the space shuttle tile/pad thermal protection system is developed and examined for imposed sinusoidal and random motions of the shuttle skin and/or applied tile pressure. The analysis accounts for the highly nonlinear stiffening hysteresis and viscous behavior of the pad which joins the tile to the shuttle skin. Where available, experimental data are used to confirm the validity of the analysis. Both analytical and experimental studies reveal that the system resonant frequency is very high for low amplitude oscillations but decreases rapidly to a minimum value with increasing amplitude. Analytical studies indicate that with still higher amplitude the resonant frequency increases slowly. The nonlinear pad is also responsible for the analytically and experimentally observed distorted response wave shapes having high sharp peaks when the system is subject to sinusoidal loads. Furthermore, energy dissipation in the pad is studied analytically and it is found that the energy dissipated is sufficiently high to cause rapid decay of dynamic transients. Nevertheless, the sharp peaked nonlinear responses of the system lead to higher magnification factors than would be expected in such a highly damped linear system.

Composition and structure of whey protein/gum arabic coacervates.

PubMed

Weinbreck, F; Tromp, R H; de Kruif, C G

2004-01-01

Complex coacervation in whey protein/gum arabic (WP/GA) mixtures was studied as a function of three main key parameters: pH, initial protein to polysaccharide mixing ratio (Pr:Ps)(ini), and ionic strength. Previous studies had already revealed under which conditions a coacervate phase was obtained. This study is aimed at understanding how these parameters influence the phase separation kinetics, the coacervate composition, and the internal coacervate structure. At a defined (Pr:Ps)(ini), an optimum pH of complex coacervation was found (pH(opt)), at which the strength of electrostatic interaction was maximum. For (Pr:Ps)(ini) = 2:1, the phase separation occurred the fastest and the final coacervate volume was the largest at pH(opt) = 4.0. The composition of the coacervate phase was determined after 48 h of phase separation and revealed that, at pH(opt), the coacervate phase was the most concentrated. Varying the (Pr:Ps)(ini) shifted the pH(opt) to higher values when (Pr:Ps)(ini) was increased and to lower values when (Pr:Ps)(ini) was decreased. This phenomenon was due to the level of charge compensation of the WP/GA complexes. Finally, the structure of the coacervate phase was studied with small-angle X-ray scattering (SAXS). SAXS data confirmed that at pH(opt) the coacervate phase was dense and structured. Model calculations revealed that the structure factor of WP induced a peak at Q = 0.7 nm(-1), illustrating that the coacervate phase was more structured, inducing the stronger correlation length of WP molecules. When the pH was changed to more acidic values, the correlation peak faded away, due to a more open structure of the coacervate. A shoulder in the scattering pattern of the coacervates was visible at small Q. This peak was attributed to the presence of residual charges on the GA. The peak intensity was reduced when the strength of interaction was increased, highlighting a greater charge compensation of the polyelectrolyte. Finally, increasing the ionic strength led to a less concentrated, a more heterogeneous, and a less structured coacervate phase, induced by the screening of the electrostatic interactions.

Magnetoencephalography for the Detection of Intervention Effects of a Specific Nutrient Combination in Patients with Mild Alzheimer’s Disease: Results from an Exploratory Double-Blind, Randomized, Controlled Study

PubMed Central

van Straaten, Elisabeth C. W.; de Waal, Hanneke; Lansbergen, Marieke M.; Scheltens, Philip; Maestu, Fernando; Nowak, Rafal; Hillebrand, Arjan; Stam, Cornelis J.

2016-01-01

Synaptic loss is an early pathological finding in Alzheimer’s disease (AD) and correlates with memory impairment. Changes in macroscopic brain activity measured with electro- and magnetoencephalography (EEG and MEG) in AD indicate synaptic changes and may therefore serve as markers of intervention effects in clinical trials. EEG peak frequency and functional networks have shown, in addition to improved memory performance, to be sensitive to detect an intervention effect in mild AD patients of the medical food Souvenaid containing the specific nutrient combination Fortasyn® Connect, which is designed to enhance synapse formation and function. Here, we explore the value of MEG, with higher spatial resolution than EEG, in identifying intervention effects of the nutrient combination by comparing MEG spectral measures, functional connectivity, and networks between an intervention and a control group. Quantitative markers describing spectral properties, functional connectivity, and graph theoretical aspects of MEG from the exploratory 24-week, double-blind, randomized, controlled Souvenir II MEG sub-study (NTR1975, http://www.trialregister.nl) in drug naïve patients with mild AD were compared between a test group (n = 27), receiving Souvenaid, and a control group (n = 28), receiving an isocaloric control product. The groups were unbalanced at screening with respect to Mini-Mental State Examination. Peak frequencies of MEG were compared with EEG peak frequencies, recorded in the same patients at similar time points, were compared with respect to sensitivity to intervention effects. No consistent statistically significant intervention effects were detected. In addition, we found no difference in sensitivity between MEG and EEG peak frequency. This exploratory study could not unequivocally establish the value of MEG in detecting interventional effects on brain activity, possibly due to small sample size and unbalanced study groups. We found no indication that the difference could be attributed to a lack of sensitivity of MEG compared with EEG. MEG in randomized controlled trials is feasible but its value to disclose intervention effects of Souvenaid in mild AD patients needs to be studied further. PMID:27799918

Magnetoencephalography for the Detection of Intervention Effects of a Specific Nutrient Combination in Patients with Mild Alzheimer's Disease: Results from an Exploratory Double-Blind, Randomized, Controlled Study.

PubMed

van Straaten, Elisabeth C W; de Waal, Hanneke; Lansbergen, Marieke M; Scheltens, Philip; Maestu, Fernando; Nowak, Rafal; Hillebrand, Arjan; Stam, Cornelis J

2016-01-01

Synaptic loss is an early pathological finding in Alzheimer's disease (AD) and correlates with memory impairment. Changes in macroscopic brain activity measured with electro- and magnetoencephalography (EEG and MEG) in AD indicate synaptic changes and may therefore serve as markers of intervention effects in clinical trials. EEG peak frequency and functional networks have shown, in addition to improved memory performance, to be sensitive to detect an intervention effect in mild AD patients of the medical food Souvenaid containing the specific nutrient combination Fortasyn ® Connect, which is designed to enhance synapse formation and function. Here, we explore the value of MEG, with higher spatial resolution than EEG, in identifying intervention effects of the nutrient combination by comparing MEG spectral measures, functional connectivity, and networks between an intervention and a control group. Quantitative markers describing spectral properties, functional connectivity, and graph theoretical aspects of MEG from the exploratory 24-week, double-blind, randomized, controlled Souvenir II MEG sub-study (NTR1975, http://www.trialregister.nl) in drug naïve patients with mild AD were compared between a test group ( n  = 27), receiving Souvenaid, and a control group ( n  = 28), receiving an isocaloric control product. The groups were unbalanced at screening with respect to Mini-Mental State Examination. Peak frequencies of MEG were compared with EEG peak frequencies, recorded in the same patients at similar time points, were compared with respect to sensitivity to intervention effects. No consistent statistically significant intervention effects were detected. In addition, we found no difference in sensitivity between MEG and EEG peak frequency. This exploratory study could not unequivocally establish the value of MEG in detecting interventional effects on brain activity, possibly due to small sample size and unbalanced study groups. We found no indication that the difference could be attributed to a lack of sensitivity of MEG compared with EEG. MEG in randomized controlled trials is feasible but its value to disclose intervention effects of Souvenaid in mild AD patients needs to be studied further.

Added Value of Reliability to a Microgrid: Simulations of Three California Buildings

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

Marnay, Chris; Lai, Judy; Stadler, Michael

The Distributed Energy Resources Customer Adoption Model is used to estimate the value an Oakland nursing home, a Riverside high school, and a Sunnyvale data center would need to put on higher electricity service reliability for them to adopt a Consortium for Electric Reliability Technology Solutions Microgrid (CM) based on economics alone. A fraction of each building's load is deemed critical based on its mission, and the added cost of CM capability to meet it added to on-site generation options. The three sites are analyzed with various resources available as microgrid components. Results show that the value placed on highermore » reliability often does not have to be significant for CM to appear attractive, about 25 $/kWcdota and up, but the carbon footprint consequences are mixed because storage is often used to shift cheaper off-peak electricity to use during afternoon hours in competition with the solar sources.« less

Data Dependent Peak Model Based Spectrum Deconvolution for Analysis of High Resolution LC-MS Data

PubMed Central

2015-01-01

A data dependent peak model (DDPM) based spectrum deconvolution method was developed for analysis of high resolution LC-MS data. To construct the selected ion chromatogram (XIC), a clustering method, the density based spatial clustering of applications with noise (DBSCAN), is applied to all m/z values of an LC-MS data set to group the m/z values into each XIC. The DBSCAN constructs XICs without the need for a user defined m/z variation window. After the XIC construction, the peaks of molecular ions in each XIC are detected using both the first and the second derivative tests, followed by an optimized chromatographic peak model selection method for peak deconvolution. A total of six chromatographic peak models are considered, including Gaussian, log-normal, Poisson, gamma, exponentially modified Gaussian, and hybrid of exponential and Gaussian models. The abundant nonoverlapping peaks are chosen to find the optimal peak models that are both data- and retention-time-dependent. Analysis of 18 spiked-in LC-MS data demonstrates that the proposed DDPM spectrum deconvolution method outperforms the traditional method. On average, the DDPM approach not only detected 58 more chromatographic peaks from each of the testing LC-MS data but also improved the retention time and peak area 3% and 6%, respectively. PMID:24533635

Isotopic disequilibrium in Globigerina bulloides and carbon isotope response to productivity increase in Southern Ocean.

PubMed

Prasanna, K; Ghosh, Prosenjit; Bhattacharya, S K; Mohan, K; Anilkumar, N

2016-02-23

Oxygen and carbon isotope ratios in planktonic foraminifera Globigerina bulloides collected from tow samples along a transect from the equatorial Indian ocean to the Southern Ocean (45°E and 80°E and 10°N to 53°S) were analysed and compared with the equilibrium δ(18)O and δ(13)C values of calcite calculated using the temperature and isotopic composition of the water column. The results agree within ~0.25‰ for the region between 10°N and 40°S and 75-200 m water depth which is considered to be the habitat of Globigerina bulloides. Further south (from 40°S to 55°S), however, the measured δ(18)O and δ(13)C values are higher than the expected values by ~2‰ and ~1‰ respectively. These enrichments can be attributed to either a 'vital effect' or a higher calcification rate. An interesting pattern of increase in the δ(13)C(DIC) value of the surface water with latitude is observed between 35°S and~ 60°S, with a peak at~ 42°S. This can be caused by increased organic matter production and associated removal. A simple model accounting for the increase in the δ(13)C(DIC) values is proposed which fits well with the observed chlorophyll abundance as a function of latitude.

Roadside increments in PM10, NOx and NO2 concentrations observed over 2 months at a major highway in New Zealand.

PubMed

Longley, Ian; Somervell, Elizabeth; Gray, Sally

Continuous and simultaneous observational particulate matter (measured as PM 10 ), nitrogen dioxide (NO 2 ) and oxides of nitrogen (NO x ) data were captured at a kerbside site alongside a major highway in Auckland, New Zealand, and at a pair of setback sites within 250 m of the highway, day and night over 8 weeks. The three measurement sites were intended to allow emissions from the highway to be largely isolated from other sources. By filtering the data and subtracting upwind concentrations, the average roadside increment was calculated to be 1.8, 7.2 and 101.4 μg m -3 for PM 10 , NO 2 and NO x , respectively, relative to a predominantly upwind setback site, and -0.1, 9.4 and 98.5 μg m -3 for PM 10 , NO 2 and NO x , respectively, relative to a downwind setback site. The negative value for PM 10 was attributed to local evening heating sources impacting the setback site. On days when peak 24 h PM 10 concentrations were observed, the absolute kerbside increment was 2.1 μg m -3 . The absolute roadside 24 h average PM 10 increment varied diurnally, peaking (on average) at 2.4 μg m -3 during peak traffic hours. The largest observed 24-h average PM 10 roadside increment was 6.9 μg m -3 and exceeded 5 μg m -3 on nine occasions. On each of these occasions, the daily mean wind speed was less than 2 m s -1 . The diurnally averaged difference in NO x concentrations between the kerbside site and the setback sites clearly resembled the diurnal cycle in traffic volume, and peaked during the morning traffic peak at around 180 μg m -3 . Background NO x concentrations were slightly higher in our study compared to a similar study in Las Vegas but absolute roadside concentrations were higher. This may be consistent with higher NO x emission factors in Auckland, but differences in the precise distance of the monitor from the road lanes and differences in meteorology need to be considered.

Reward Value Effects on Timing in the Peak Procedure

ERIC Educational Resources Information Center

Galtress, Tiffany; Kirkpatrick, Kimberly

2009-01-01

Three experiments examined the effect of motivational variables on timing in the peak procedure. In Experiment 1, rats received a 60-s peak procedure that was coupled with long-term, between-phase changes in reinforcer magnitude. Increases in reinforcer magnitude produced a leftward shift in the peak that persisted for 20 sessions of training. In…

The electric field distributions in anatomical head models during transcranial direct current stimulation for post-stroke rehabilitation.

PubMed

Manoli, Zoi; Parazzini, Marta; Ravazzani, Paolo; Samaras, Theodoros

2017-01-01

The lack of knowledge of the electric field distribution inside the brain of stroke patients receiving transcranial direct current stimulation (tDCS) calls for estimating it computationally. Moreover, the impact on this distribution of a novel clinical management approach which involves secondary motor areas (SMA) in stroke rehabilitation needs to be evaluated. Finally, the differences in the electric field distributions due to gender and age need to be investigated. This work presents the development of two different anatomical models (young adult female and elderly male) with an ischemic stroke region of spherical volume 10 cm 3 or 50 cm 3 , using numerical models of the Virtual Population (ViP). The stroke phase was considered as acute or chronic, resulting in different electrical properties of the area. Two different electrode montages were used - One over the lesion area and the contralateral supra-orbital region and the other over the SMA and the contralateral supra-orbital region. A quasi-electrostatic solver was used to numerically solve the Laplace equation with the finite-difference technique. Both the 99th percentile of the electric field intensity distribution ("E peak value") and the percentage of the tissue volumes with electric field intensity over 50% and 70% of the E peak value were assessed inside the target areas of the primary motor cortex (M1) and the SMA, as well as in other brain tissues (hypothalamus and cerebellum). In the acute phase of an ischemic stroke, the normalized electric field intensity distributions do not differ noticeably compared to those in the brain of a healthy person (mean square difference < 2%). The difference becomes larger (up to 4.5%) for the chronic phase of a large ischemic lesion. Moreover, the maximum values of the induced electric field in the tissues in the SMA are almost equal for both electrode montages. The peak values of the electric field distribution ("E peak values") in cerebellum and hypothalamus for both electrode montages are rather small but different from those of healthy patients. The largest difference of 21% decrease with respect to a healthy subject was noticed in the elder adult model with a large chronic lesion. The comparison of the different electrode montages shows that the use of a stimulating electrode over the affected area creates larger values of the electric field in M1, by up to 26% for a small chronic lesion in the young female model. On the contrary, the montage does not affect considerably (change less than 8%) the E peak values in the SMA. This implies that for exciting M1, the M1-Fp2 montage should be favored. The presence and the phase of an ischemic stroke lesion, as well as the configuration of electrode montages affect the distribution and the maximum value of the electric field induced in tissues. Moreover, patients whom seem to benefit most from tDCS are those in the chronic phase of an ischemic stroke, since contrasts in the tissue conductivity result in a higher electric field induced around the lesion volume, which could stimulate the remaining healthy tissue in the area. © 2016 American Association of Physicists in Medicine.

[Study on Hydrothermal Preparation and Luminescence Properties of Luminescent Material BaSrMg(PO₄)₂:Eu³⁺].

PubMed

Hu, Qing-song; Zhu, Cheng-jing; Xia, Yue-yi; Wang, Li-li; Liu, Wen-han; Pan, Zai-fa

2016-02-01

Eu³⁺ doped BaSrMg (PO₄)₂ were prepared by a hydrothermal method. The crystal structure and morphology of BaSrMg(PO₄)₂:Eu³⁺ phosphor were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM). The effects of different pH values (5, 6, 7 and 8) and different reaction temperatures (120, 140, 160, 180 and 200 °C) on the crystal structure and morphology of BaSrMg(PO₄)₂:Eu³⁺ phosphor were studied in this paper. The results of XRD indicate that diffraction peaks are sharp and strong only when pH value is 6, meanwhile the FESEM shows the morphology is regular-shaped. The XRD patterns show amorphous halos superimposed with several weak sharp peaks for the samples preparing under the pH values of 5, 7 and 8. It indicates that these three samples are solid solution or mixed phases, which are in accord with the results of FESEM. From the fluorescence spectra, the peaks in the excitation spectra were assigned to the transition from ⁷F₀ to ⁵D₄, ⁵L₈, ⁵L₆ and ⁵D₂, while the peaks of emission spectra corresponding to the transition of ⁵D₁ --> ⁷F₁ and ⁵D₀-->⁷Fj (J = 0, 1, 2, 3 and 4). The strongest emission peak of the optimized phosphor located at 613 nm (⁵D0--> ⁷F₂), excited by the main excitation peak with wavelength of 394 nm. The splitting of the emission peaks changes depends on pH values and temperatures, which indicating that luminescence properties is closely related to the crystal structure and morphology of particles.

Foot loading with an ankle-foot orthosis: the accuracy of an integrated physical strain trainer.

PubMed

Pauser, Johannes; Jendrissek, Andreas; Brem, Matthias; Gelse, Kolja; Swoboda, Bernd; Carl, Hans-Dieter

2012-07-01

To investigate the value of a built-in physical strain trainer for the monitoring of partial weight bearing with an ankle-foot orthosis. 12 healthy volunteers were asked to perform three trials. Plantar peak pressure values from normal gait (trial one) were defined as 100% (baseline). The following trials were performed with the Vacoped® dynamic vacuum ankle orthosis worn in a neutral position with full weight bearing (trial two) and a restriction to 10% body weight (BW) (trial three), as monitored with an integrated physical strain trainer. Peak plantar pressure values were obtained using the pedar® X system. Peak pressure values were statistically significantly reduced wearing the Vacoped® shoe with full weight bearing for the hindfoot to 68% of the baseline (normal gait) and for the midfoot and forefoot to 83% and 60%, respectively. Limited weight bearing with 10% BW as controlled by physical strain trainer further reduced plantar peak pressure values for the hindfoot to 19%, for the midfoot to 43% of the baseline and the forefoot to 22% of the baseline. The Vacoped® vacuum ankle orthosis significantly reduces plantar peak pressure. The integrated physical strain trainer seems unsuitable to monitor a limitation to 10% BW adequately for the total foot. The concept of controlling partial weight bearing with the hindfoot-addressing device within the orthosis seems debatable but may be useful when the hindfoot in particular must be off-loaded.

Discharge mode transition and temporal-spatial evolution of an air-water plasma jet generated by pulsating DC power

NASA Astrophysics Data System (ADS)

Lei, J.; Geng, Y.; Liu, K.; Zhu, W.; Zheng, Z.; Hu, H.

2017-12-01

In this paper, pulsating direct current air-water plasma jet, which can increase the production of •OH and decrease the temperature, is studied. The results show that the discharge mode changes in one cycle from corona discharge with steep Trichel current pulse to glow-like discharge. It is unknown whether the different discharge modes and water ratio have an effect on the transient process of the excited O and •OH production and the mechanism of plasma propagation. So, a series of experiments are done in this paper. The results show that the changing rules of both the excited state O and the discharge current reach their two peak values synchronously. And its maximum appears at the time of the first peak current value in corona mode. However, the change of the excited state •OH is different. It increases to its maximum at the time of the second peak current value in glow-like mode. Besides, the intensified charge coupled device photographs show that the luminous intensity of the discharge zone at the first peak current value in corona mode is stronger than the second peak current value in glow-like mode. At the same time, the discharge area of the former is larger than the latter. Nevertheless, with the increase in water ratio, the discharge area change reversed. Additionally, the air plasma plume propagation depends on the gas flow. The initial propagation velocity decreases with the increase in water ratio.

2D Raman band splitting in graphene: Charge screening and lifting of the K-point Kohn anomaly.

PubMed

Wang, Xuanye; Christopher, Jason W; Swan, Anna K

2017-10-19

Pristine graphene encapsulated in hexagonal boron nitride has transport properties rivalling suspended graphene, while being protected from contamination and mechanical damage. For high quality devices, it is important to avoid and monitor accidental doping and charge fluctuations. The 2D Raman double peak in intrinsic graphene can be used to optically determine charge density, with decreasing peak split corresponding to increasing charge density. We find strong correlations between the 2D 1 and 2D 2 split vs 2D line widths, intensities, and peak positions. Charge density fluctuations can be measured with orders of magnitude higher precision than previously accomplished using the G-band shift with charge. The two 2D intrinsic peaks can be associated with the "inner" and "outer" Raman scattering processes, with the counterintuitive assignment of the phonon closer to the K point in the KM direction (outer process) as the higher energy peak. Even low charge screening lifts the phonon Kohn anomaly near the K point for graphene encapsulated in hBN, and shifts the dominant intensity from the lower to the higher energy peak.

Quantifying the added value of convection-permitting climate simulations in complex terrain: a systematic evaluation of WRF over the Himalayas

NASA Astrophysics Data System (ADS)

Karki, Ramchandra; Hasson, Shabeh ul; Gerlitz, Lars; Schickhoff, Udo; Scholten, Thomas; Böhner, Jürgen

2017-07-01

Mesoscale dynamical refinements of global climate models or atmospheric reanalysis have shown their potential to resolve intricate atmospheric processes, their land surface interactions, and subsequently, realistic distribution of climatic fields in complex terrains. Given that such potential is yet to be explored within the central Himalayan region of Nepal, we investigate the skill of the Weather Research and Forecasting (WRF) model with different spatial resolutions in reproducing the spatial, seasonal, and diurnal characteristics of the near-surface air temperature and precipitation as well as the spatial shifts in the diurnal monsoonal precipitation peak over the Khumbu (Everest), Rolwaling, and adjacent southern areas. Therefore, the ERA-Interim (0.75°) reanalysis has been dynamically refined to 25, 5, and 1 km (D1, D2, and D3) for one complete hydrological year (October 2014-September 2015), using the one-way nested WRF model run with mild nudging and parameterized convection for the outer but explicitly resolved convection for the inner domains. Our results suggest that D3 realistically reproduces the monsoonal precipitation, as compared to its underestimation by D1 but overestimation by D2. All three resolutions, however, overestimate precipitation from the westerly disturbances, owing to simulating anomalously higher intensity of few intermittent events. Temperatures are generally reproduced well by all resolutions; however, winter and pre-monsoon seasons feature a high cold bias for high elevations while lower elevations show a simultaneous warm bias. Unlike higher resolutions, D1 fails to realistically reproduce the regional-scale nocturnal monsoonal peak precipitation observed in the Himalayan foothills and its diurnal shift towards high elevations, whereas D2 resolves these characteristics but exhibits a limited skill in reproducing such a peak on the river valley scale due to the limited representation of the narrow valleys at 5 km resolution. Nonetheless, featuring a substantial skill over D1 and D2, D3 simulates almost realistic shapes of the seasonal and diurnal precipitation and the peak timings even on valley scales. These findings clearly suggest an added value of the convective-scale resolutions in realistically resolving the topoclimates over the central Himalayas, which in turn allows simulating their interactions with the synoptic-scale weather systems prevailing over high Asia.

Multiple resonance peaks of FeCo thin films with NiFe underlayer

NASA Astrophysics Data System (ADS)

Zhong, Xiaoxi; Soh, Wee Tee; Phuoc, Nguyen N.; Liu, Ying; Ong, C. K.

2015-01-01

Under zero external magnetic fields, single-layer FeCo thin films exhibit no ferromagnetic resonance (FMR) peaks, while multiple FMR peaks were obtained by growing FeCo thin films on NiFe underlayers with various thicknesses up to 50 nm. Comprehensive investigations of the dynamic magnetic properties and origin of the peaks were conducted through measurements of microwave permeability via a shorted microstrip perturbation technique. Through fitted values of saturation magnetization Ms, uniaxial anisotropy HKsta, and rotatable anisotropy HKrot extracted from the FMR experiments, it was found that two of the three resonance peaks originate from FeCo, and the third from NiFe. The two magnetic phases of FeCo grains are found to have different values of HKrot and explained by the exchange interaction between FeCo and NiFe grains.

Prognostic value of a new cardiopulmonary exercise testing parameter in chronic heart failure: oxygen uptake efficiency at peak exercise - comparison with oxygen uptake efficiency slope.

PubMed

Toste, Alexandra; Soares, Rui; Feliciano, Joana; Andreozzi, Valeska; Silva, Sofia; Abreu, Ana; Ramos, Ruben; Santos, Ninel; Ferreira, Lurdes; Ferreira, Rui Cruz

2011-10-01

A growing body of evidence shows the prognostic value of oxygen uptake efficiency slope (OUES), a cardiopulmonary exercise test (CPET) parameter derived from the logarithmic relationship between O(2) consumption (VO(2)) and minute ventilation (VE) in patients with chronic heart failure (CHF). To evaluate the prognostic value of a new CPET parameter - peak oxygen uptake efficiency (POUE) - and to compare it with OUES in patients with CHF. We prospectively studied 206 consecutive patients with stable CHF due to dilated cardiomyopathy - 153 male, aged 53.3±13.0 years, 35.4% of ischemic etiology, left ventricular ejection fraction 27.7±8.0%, 81.1% in sinus rhythm, 97.1% receiving ACE-Is or ARBs, 78.2% beta-blockers and 60.2% spironolactone - who performed a first maximal symptom-limited treadmill CPET, using the modified Bruce protocol. In 33% of patients an cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device (CRT-D) was implanted during follow-up. Peak VO(2), percentage of predicted peak VO(2), VE/VCO(2) slope, OUES and POUE were analyzed. OUES was calculated using the formula VO(2) (l/min) = OUES (log(10)VE) + b. POUE was calculated as pVO(2) (l/min) / log(10)peakVE (l/min). Correlation coefficients between the studied parameters were obtained. The prognosis of each variable adjusted for age was evaluated through Cox proportional hazard models and R2 percent (R2%) and V index (V6) were used as measures of the predictive accuracy of events of each of these variables. Receiver operating characteristic (ROC) curves from logistic regression models were used to determine the cut-offs for OUES and POUE. pVO(2): 20.5±5.9; percentage of predicted peak VO(2): 68.6±18.2; VE/VCO(2) slope: 30.6±8.3; OUES: 1.85±0.61; POUE: 0.88±0.27. During a mean follow-up of 33.1±14.8 months, 45 (21.8%) patients died, 10 (4.9%) underwent urgent heart transplantation and in three patients (1.5%) a left ventricular assist device was implanted. All variables proved to be independent predictors of this combined event; however, VE/VCO2 slope was most strongly associated with events (HR 11.14). In this population, POUE was associated with a higher risk of events than OUES (HR 9.61 vs. 7.01), and was also a better predictor of events (R2: 28.91 vs. 22.37). POUE was more strongly associated with death, urgent heart transplantation and implantation of a left ventricular assist device and proved to be a better predictor of events than OUES. These results suggest that this new parameter can increase the prognostic value of CPET in patients with CHF. Copyright © 2011 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

End-exercise ΔHHb/ΔVO2 and post-exercise local oxygen availability in relation to exercise intensity.

PubMed

Stöcker, F; Von Oldershausen, C; Paternoster, F K; Schulz, T; Oberhoffer, R

2017-07-01

Increased local blood supply is thought to be one of the mechanisms underlying oxidative adaptations to interval training regimes. The relationship of exercise intensity with local blood supply and oxygen availability has not been sufficiently evaluated yet. The aim of this study was to examine the effect of six different intensities (40-90% peak oxygen uptake, VO 2peak ) on relative changes in oxygenated, deoxygenated and total haemoglobin (ΔO 2 Hb, ΔHHb, ΔTHb) concentration after exercise as well as end-exercise ΔHHb/ΔVO 2 as a marker for microvascular O 2 distribution. Seventeen male subjects performed an experimental protocol consisting of 3 min cycling bouts at each exercise intensity in randomized order, separated by 5 min rests. ΔO 2 Hb and ΔHHb were monitored with near-infrared spectroscopy of the vastus lateralis muscle, and VO 2 was assessed. ΔHHb/ΔVO 2 increased significantly from 40% to 60% VO 2 peak and decreased from 60% to 90% VO 2 peak. Post-exercise ΔTHb and ΔO 2 Hb showed an overshoot in relation to pre-exercise values, which was equal after 40-60% VO 2peak and rose significantly thereafter. A plateau was reached following exercise at ≥80% VO 2peak . The results suggest that there is an increasing mismatch of local O 2 delivery and utilization during exercise up to 60% VO 2peak . This insufficient local O 2 distribution is progressively improved above that intensity. Further, exercise intensities of ≥80% VO 2peak induce highest local post-exercise O 2 availability. These effects are likely due to improved microvascular perfusion by enhanced vasodilation, which could be mediated by higher lactate production and the accompanying acidosis. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Local magnitude scale for Valle Medio del Magdalena region, Colombia

NASA Astrophysics Data System (ADS)

Londoño, John Makario; Romero, Jaime A.

2017-12-01

A local Magnitude (ML) scale for Valle Medio del Magdalena (VMM) region was defined by using 514 high quality earthquakes located at VMM area and inversion of 2797 amplitude values of horizontal components of 17 stations seismic broad band stations, simulated in a Wood-Anderson seismograph. The derived local magnitude scale for VMM region was: ML =log(A) + 1.3744 ∗ log(r) + 0.0014776 ∗ r - 2.397 + S Where A is the zero-to-peak amplitude in nm in horizontal components, r is the hypocentral distance in km, and S is the station correction. Higher values of ML were obtained for VMM region compared with those obtained with the current formula used for ML determination, and with California formula. With this new scale ML values are adjusted to local conditions beneath VMM region leading to more realistic ML values. Moreover, with this new ML scale the seismicity caused by tectonic or fracking activity at VMM region can be monitored more accurately.

High methane natural gas/air explosion characteristics in confined vessel.

PubMed

Tang, Chenglong; Zhang, Shuang; Si, Zhanbo; Huang, Zuohua; Zhang, Kongming; Jin, Zebing

2014-08-15

The explosion characteristics of high methane fraction natural gas were investigated in a constant volume combustion vessel at different initial conditions. Results show that with the increase of initial pressure, the peak explosion pressure, the maximum rate of pressure rise increase due to a higher amount (mass) of flammable mixture, which delivers an increased amount of heat. The increased total flame duration and flame development time result as a consequence of the higher amount of flammable mixture. With the increase of the initial temperature, the peak explosion pressures decrease, but the pressure increase during combustion is accelerated, which indicates a faster flame speed and heat release rate. The maximum value of the explosion pressure, the maximum rate of pressure rise, the minimum total combustion duration and the minimum flame development time is observed when the equivalence ratio of the mixture is 1.1. Additionally, for higher methane fraction natural gas, the explosion pressure and the maximum rate of pressure rise are slightly decreased, while the combustion duration is postponed. The combustion phasing is empirically correlated with the experimental parameters with good fitting performance. Furthermore, the addition of dilute gas significantly reduces the explosion pressure, the maximum rate of pressure rise and postpones the flame development and this flame retarding effect of carbon dioxide is stronger than that of nitrogen. Copyright © 2014 Elsevier B.V. All rights reserved.

Random walkers with extreme value memory: modelling the peak-end rule

NASA Astrophysics Data System (ADS)

Harris, Rosemary J.

2015-05-01

Motivated by the psychological literature on the ‘peak-end rule’ for remembered experience, we perform an analysis within a random walk framework of a discrete choice model where agents’ future choices depend on the peak memory of their past experiences. In particular, we use this approach to investigate whether increased noise/disruption always leads to more switching between decisions. Here extreme value theory illuminates different classes of dynamics indicating that the long-time behaviour is dependent on the scale used for reflection; this could have implications, for example, in questionnaire design.

Resolution Quality and Atom Positions in Sub-Angstrom Electron Microscopy

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

O'Keefe, Michael A.; Allard, Lawrence F.; Blom, Douglas A.

2005-02-15

Ability to determine whether an image peak represents one single atom or several depends on resolution of the HR-(S)TEM. Rayleigh's resolution criterion, an accepted standard in optics, was derived as a means for judging when two image intensity peaks from two sources of light (stars) are distinguishable from a single source. Atom spacings closer than the Rayleigh limit have been resolved in HR-TEM, suggesting that it may be useful to consider other limits, such as the Sparrow resolution criterion. From the viewpoint of the materials scientist, it is important to be able to use the image to determine whether anmore » image feature represents one or more atoms (resolution), and where the atoms (or atom columns) are positioned relative to one another (resolution quality). When atoms and the corresponding image peaks are separated by more than the Rayleigh limit of the HR-(S)TEM, it is possible to adjust imaging parameters so that relative peak positions in the image correspond to relative atom positions in the specimen. When atoms are closer than the Rayleigh limit, we must find the relationship of the peak position to the atom position by peak fitting or, if we have a suitable model, by image simulation. Our Rayleigh-Sparrow parameter QRS reveals the ''resolution quality'' of a microscope image. QRS values greater than 1 indicate a clearly resolved twin peak, while values between 1 and 0 mean a lower-quality resolution and an image with peaks displaced from the relative atom positions. The depth of the twin-peak minimum can be used to determine the value of QRS and the true separation of the atom peaks that sum to produce the twin peak in the image. The Rayleigh-Sparrow parameter can be used to refine relative atom positions in defect images where atoms are closer than the Rayleigh limit of the HR-(S)TEM, reducing the necessity for full image simulations from large defect models.« less

Effect of Endurance Training on the Determinants of Peak Exercise Oxygen Consumption in Elderly Patients with Stable Compensated Heart Failure and Preserved Ejection Fraction

PubMed Central

Haykowsky, Mark J.; Brubaker, Peter H.; Stewart, Kathryn P.; Morgan, Timothy M.; Eggebeen, Joel; Kitzman, Dalane W.

2012-01-01

Objective Evaluate the mechanism(s) for improved exercise capacity after endurance exercise training (ET) in elderly patients with heart failure and preserved ejection fraction (HFPEF). Background: Exercise intolerance, measured objectively by reduced peak oxygen consumption (VO2), is the primary chronic symptom in HFPEF and is improved by ET. However, the mechanism(s) are unknown. Methods Forty stable, compensated HFPEF outpatients (mean age 69 ± 6 yrs) were examined at baseline and after 4 months of ET (n=22) or attention control (n=18). VO2 and its determinants were assessed during rest and peak upright cycle exercise. Results Following ET, peak VO2 was higher than controls (16.3 ± 2.6 vs. 13.1 ± 3.4 ml/kg/min; p=0.002). This was associated with higher peak heart rate (139 ± 16 vs. 131 ± 20 beats/min; p=0.03), but no difference in peak end-diastolic volume (77 ± 18 vs. 77 ± 17 ml; p=0.51), stroke volume (48 ± 9 vs. 46 ± 9 ml; p=0.83), or cardiac output (6.6 ± 1.3 vs. 5.9 ± 1.5 L/min; p=0.32). However, estimated peak arterial-venous oxygen difference (A-VO2 Diff) was significantly higher in ET (19.8 ± 4.0 vs. 17.3 ± 3.7 ml/dl; p=0.03). The effect of ET on cardiac output was responsible for < 15% of the improvement in peak VO2. Conclusions In elderly stable compensated HFPEF patients, peak A-VO2 Diff was higher following ET and was the primary contributor to improved peak VO2. This suggests that peripheral mechanisms (improved microvascular and/or skeletal muscle function) contribute to the improved exercise capacity after ET in HFPEF. PMID:22766338

Dielectric Properties of PMMA and its Composites with ZrO2

NASA Astrophysics Data System (ADS)

Sannakki, Basavaraja; Anita

The polymer films of PMMA with different thickness and its composites with ZrO2 at various weight percentages but of same thickness have been studied. The determination of its dielectric properties, dielectric loss, a.conductivity and dielectric modulus were carried out using capacitance measurements of the above samples as a function of frequency, over the range 50 Hz - 5 MHz at room temperature. The films of PMMA and its composites have been characterized using X-Ray Diffractometer. The dielectric permittivity of films of PMMA behaves nonlinearly as frequency increases over the range 50-300 Hz, where as above 300 Hz the values of dielectric constant remains constant. But it is observed that the dielectric constant of PMMA increases as thickness of the film increases. In case of composite films of PMMA with ZrO2 the values of dielectric permittivity decreases gradually up to frequency of around 1 KHz and at higher frequencies it remains constant for all the weight percentages of ZrO2. The complex form of dielectric modulus of PMMA is obtained from the experimentally measured data of dielectric constant and dielectric loss values. The relaxation time of the orientation of dipoles is obtained from the peak value of angular frequency through the plots of imaginary part of electrical modulus as function of frequency. The impedance of PMMA polymer increases as thickness of the films increases. The a c conductivity of PMMA film remains constant up to frequency of 1 MHz and above. It shows a nonlinear phenomenon with peak values at frequency 4 MHz. Shape and size of the nanoparticles of composite film of PMMA with ZrO2 was analyzed by Field Emission Scanning Electron Microscope (FESEM).

Effect of harvest time of red and white clover silage on chewing activity and particle size distribution in boli, rumen content and faeces in cows.

PubMed

Kornfelt, L F; Nørgaard, P; Weisbjerg, M R

2013-06-01

The study examined the effects of harvest time of red and white clover silage on eating and ruminating activity and particle size distribution in feed boli, rumen content and faeces in cows. The clover crops were harvested at two stages of growth and ensiled in bales. Red clover crops had 36% and 45% NDF in dry matter (DM) at early (ER) and late (LR) harvest, respectively, and the white clover crops had 19% and 29% NDF in DM at the early (EW) and late (LW) harvest, respectively. The silages were fed restrictively (80% of ad libitum intake) twice daily to four rumen cannulated non-lactating Jersey cows (588 ± 52 kg) in a 4 × 4 Latin square design. Jaw movements (JM) were recorded for 96 h continuously. Swallowed boli, rumen mat, rumen fluid and faeces samples were collected, washed in nylon bags (0.01 mm pore size) and freeze-dried before dry sieving through 4.750, 2.360, 1.000, 0.500, 0.212 and 0.106 mm into seven fractions. The length (PL) and width (PW) values of rumen and faeces particles within each fraction were measured by use of image analysis. The eating activity (min/kg DM intake; P < 0.05) was higher in LR compared with the other treatments. The eating activity (min/kg NDF intake; P < 0.05) was affected by clover type with highest values for white clover silage. The mean ruminating time (min/kg DM), daily ruminating cycles (P < 0.001) and JM during ruminating (P < 0.05) were affected by treatment with increasing values at later harvest time. The proportion of washed particle DM of total DM in boli (P < 0.001), rumen mat (P < 0.001), rumen fluid (P < 0.01) and faeces was (P < 0.001) highest by feeding LR. There were identified two peaks (modes 1 and 2) on the probability density distribution (PDF) of PW values of rumen mat and faeces, but only one peak (mode 1) for PL values. There was no difference in the mean and mode 1 PW and PL value in rumen mat between the four treatments. The mean PL, mode PL, mode 2 PW and mean PW in faeces were highest for LR (P < 0.05). The mean particle size in boli measured by sieving was higher at white clover compared with red clover treatments (P < 0.001) and the highest value in faeces was found in LR (P < 0.01). The two peaks on PDF for width values of rumen mat and faeces particles are most likely related to the leaves and the stems/petioles. In conclusion, the mean total chewing activity per kg DM was lowest for the white clover silage and increased for both silages due to later harvest time. The mean particle size in boli was smallest for LR, whereas the mean PL and PW in faeces were highest for the LR.

The effect of level of feeding, genetic merit, body condition score and age on biological parameters of a mammary gland model.

PubMed

Bryant, J R; Lopez-Villalobos, N; Holmes, C W; Pryce, J E; Pitman, G D; Davis, S R

2007-03-01

An evolutionary algorithm was applied to a mechanistic model of the mammary gland to find the parameter values that minimised the difference between predicted and actual lactation curves of milk yields in New Zealand Jersey cattle managed at different feeding levels. The effect of feeding level, genetic merit, body condition score at parturition and age on total lactation yields of milk, fat and protein, days in milk, live weight and evolutionary algorithm derived mammary gland parameters was then determined using a multiple regression model. The mechanistic model of the mammary gland was able to fit lactation curves that corresponded to actual lactation curves with a high degree of accuracy. The senescence rate of quiescent (inactive) alveoli was highest at the very low feeding level. The active alveoli population at peak lactation was highest at very low feeding levels, but lower nutritional status at this feeding level prevented high milk yields from being achieved. Genetic merit had a significant linear effect on the active alveoli population at peak and mid to late lactation, with higher values in animals, which had higher breeding values for milk yields. A type of genetic merit × feeding level scaling effect was observed for total yields of milk and fat, and total number of alveoli produced from conception until the end of lactation with the benefits of increases in genetic merit being greater at high feeding levels. A genetic merit × age scaling effect was observed for total lactation protein yields. Initial rates of differentiation of progenitor cells declined with age. Production levels of alveoli from conception to the end of lactation were lowest in 5- to 8-year-old animals; however, in these older animals, quiescent alveoli were reactivated more frequently. The active alveoli population at peak lactation and rates of active alveoli proceeding to quiescence were highest in animals of intermediate body condition scores of 4.0 to 5.0. The results illustrate the potential uses of a mechanistic model of the mammary gland to fit a lactation curve and to quantify the effects of feeding level, genetic merit, body condition score, and age on mammary gland dynamics throughout lactation.

Incidence, risk factors and outcomes of acute kidney injury (AKI) in patients with acute-on-chronic liver failure (ACLF) of underlying cirrhosis.

PubMed

Zang, Hong; Liu, Fangfang; Liu, Hongling; You, Shaoli; Zhu, Bing; Wan, Zhihong; Xin, Shaojie

2016-09-01

Acute kidney injury (AKI) is a life-threatening complication in patients with acute-on-chronic liver failure (ACLF) of underlying cirrhosis. However, the characteristics of AKI in these patients have not been clarified. Our aim was to determine the incidence and risk factors of AKI and the association between AKI severity and 180-day transplant-free survival. We performed a retrospective cohort analysis of patients with ACLF of underlying cirrhosis in a single center from January 2009 through December 2014. AKI was defined by the criteria proposed by International Club of Ascites (ICA). The incidence and risk factors of AKI development and its relationship to 180-day transplant-free survival rates were evaluated. Of 1032 patients with ACLF of underlying cirrhosis, 121 (11.72 %) had AKI at admission, and 319 (30.9 %) developed AKI during hospitalization. We established a logistic regression model including four independent factors with AKI development: MELD score [odds ratio (OR), 1.1; 95 % confidence interval (CI), 1.07-1.14], presence of ascites (OR, 3.80; 95 % CI, 2.13-6.78), sepsis/infection (OR, 2.25; 95 % CI, 1.66-3.03) and acute variceal bleed (OR, 1.78; 95 % CI, 1.00-3.19). The area under receiver operating characteristics of the model in internal and external validations were 0.95 and 0.85, respectively. Patients with mild-A AKI had a higher 180-day transplant-free survival rate (23.8 %) than patients with mild-B AKI (19.0 %) or marked AKI (5.9 %) (all p < 0.001). AKI patients with a peak value of sCr <1.5 mg/dl had higher 180-day transplant-free survival rates compared to those with a peak value of sCr ≧1.5 mg/dl (23.8 % vs. 14.7 %, p < 0.001). We developed a clinical risk model for predicting development of AKI with great accuracy. Combining the ICA-AKI criteria and the peak value of sCr with 1.5 mg/dl provides a good prognostic method for patients with ACLF of underlying cirrhosis.

Decreased knee adduction moment does not guarantee decreased medial contact force during gait.

PubMed

Walter, Jonathan P; D'Lima, Darryl D; Colwell, Clifford W; Fregly, Benjamin J

2010-10-01

Excessive contact force is believed to contribute to the development of medial compartment knee osteoarthritis. The external knee adduction moment (KAM) has been identified as a surrogate measure for medial contact force during gait, with an abnormally large peak value being linked to increased pain and rate of disease progression. This study used in vivo gait data collected from a subject with a force-measuring knee implant to assess whether KAM decreases accurately predict corresponding decreases in medial contact force. Changes in both quantities generated via gait modification were analyzed statistically relative to the subject's normal gait. The two gait modifications were a "medial thrust" gait involving knee medialization during stance phase and a "walking pole" gait involving use of bilateral walking poles. Reductions in the first (largest) peak of the KAM (32-33%) did not correspond to reductions in the first peak of the medial contact force. In contrast, reductions in the second peak and angular impulse of the KAM (15-47%) corresponded to reductions in the second peak and impulse of the medial contact force (12-42%). Calculated reductions in both KAM peaks were highly sensitive to rotation of the shank reference frame about the superior-inferior axis of the shank. Both peaks of medial contact force were best predicted by a combination of peak values of the external KAM and peak absolute values of the external knee flexion moment (R(2) = 0.93). Future studies that evaluate the effectiveness of gait modifications for offloading the medial compartment of the knee should consider the combined effect of these two knee moments. Published by Wiley Periodicals, Inc. J Orthop Res 28:1348-1354, 2010.

ACL deficient potential copers and non-copers reveal different isokinetic quadriceps strength profiles in the early stage after injury

PubMed Central

Eitzen, I; Eitzen, TJ; Holm, I; Snyder-Mackler, L; Risberg, MA

2011-01-01

Background Isokinetic muscle strength tests using the peak torque value is the most frequently included quadriceps muscle strength measurement for anterior cruciate ligament (ACL) injured subjects. Aims The purpose of this study was to investigate quadriceps muscle performance during the whole isokinetic curve in ACL deficient subjects classified as potential copers or non-copers, and investigate whether these curve profiles were associated with single-leg hop performance. We hypothesized that quadriceps muscle torque at other knee flexion angles than peak torque would give more information about quadriceps muscle strength deficits. Furthermore, we hypothesized that there would be significant torque differences between potential copers and non-copers, and a significant relationship between angle specific torque values and single-leg hop performance. Study Design Cross-sectional study; Level of evidence, 2 Methods Seventy-six individuals with a complete unilateral ACL rupture within the last 3 months were included. The subjects were classified into potential copers and non-copers according to the criteria from Fitzgerald et al12. Isokinetic quadriceps muscle tests were performed at 60°/sec (Biodex 6000). Mean torque values were calculated for peak torque as well as for specific knee flexion angles. The one-leg hop and the 6 meter timed hop tests were included and symmetry indices were used. Results The peak torque value did not identify the largest quadriceps muscle strength deficit. Rather, these were established at knee flexion angles of less than 40°. There were significant differences in angle specific torque values between potential copers and non-copers (p<0.05). Moderate to strong associations were disclosed between angle specific torque values and single-leg hop performance, but only for non-copers (r≥0.32– 0.58). Conclusions Angle specific quadriceps muscle torque values of less than 40° of knee flexion provide more information on the quadriceps strength deficits after ACL injury compared to the commonly used peak torque values. PMID:20110458

Fractured Rock Permeability as a Function of Temperature and Confining Pressure

NASA Astrophysics Data System (ADS)

Alam, A. K. M. Badrul; Fujii, Yoshiaki; Fukuda, Daisuke; Kodama, Jun-ichi; Kaneko, Katsuhiko

2015-10-01

Triaxial compression tests were carried out on Shikotsu welded tuff, Kimachi sandstone, and Inada granite under confining pressures of 1-15 MPa at 295 and 353 K. The permeability of the tuff declined monotonically with axial compression. The post-compression permeability became smaller than that before axial compression. The permeability of Kimachi sandstone and Inada granite declined at first, then began to increase before the peak load, and showed values that were almost constant in the residual strength state. The post-compression permeability of Kimachi sandstone was higher than that before axial compression under low confining pressures, but lower under higher confining pressures. On the other hand, the permeability of Inada granite was higher than that before axial compression regardless of the confining pressure values. For the all rock types, the post-compression permeability at 353 K was lower than at 295 K and the influence of the confining pressure was less at 353 K than at 295 K. The above temperature effects were observed apparently for Inada granite, only the latter effect was apparent for Shikotsu welded tuff, and they were not so obvious for Kimachi sandstone. The mechanisms causing the variation in rock permeability and sealability of underground openings were discussed.

Numerical simulation of adverse-pressure-gradient boundary layer with or without roughness

NASA Astrophysics Data System (ADS)

Mottaghian, Pouya; Yuan, Junlin; Piomelli, Ugo

2014-11-01

Large-eddy and direct numerical simulations are carried out on flat-plate boundary layer over smooth and rough surfaces, with adverse pressure gradient.The deceleration is achieved by imposing a wall-normal freestream velocity profile, and is strong enough to cause separation at the wall. The Reynolds number based on momentum thickness and freestream velocity at inlet is 600. Numerical sandgrain roughness is applied based on an immersed boundary method, yielding a flow that is transitionally rough. The turbulence intensity increases before separation, and reaches a higher value for the rough case, indicating stronger mixing. Roughness also causes higher momentum deficit near the wall, leading to earlier separation. This is consistent with previous observation made on rough-wall flow separation over a ramp. In both cases, the turbulent kinetic energy peaks inside the shear layer above the detachment region, with higher values in the rough case; it then decreases approaching the reattachment region. Near the wall inside the separation bubble, the near-zero turbulent intensity indicates that the turbulent structures are lifted up in the separation region. Compared with the smooth case, the shear layer is farther from the wall and the reattachment length is longer on the rough wall.

Tunable microwave absorbing nano-material for X-band applications

NASA Astrophysics Data System (ADS)

Sadiq, Imran; Naseem, Shahzad; Ashiq, Muhammad Naeem; Khan, M. A.; Niaz, Shanawer; Rana, M. U.

2016-03-01

The effect of rare earth elements substitution in Sr1.96RE0.04Co2Fe27.80Mn0.2O46 (RE=Ce, Gd, Nd, La and Sm) X-type hexagonal ferrites prepared by using sol gel autocombustion method was studied. The XRD and FTIR analysis show the single phase of the prepared material. The lattice constants a (Å) and c (Å) varies with the additives. The particle size measured by Scherer formula for all the samples varies in the range of 54-100 nm and confirmed by the TEM analysis. The average grain size measured by SEM analysis lies in the range of 0.672-1.01 μm for all the samples. The Gd-substituted ferrite has higher value of coercivity (526.06 G) among all the samples which could be a good material for longitudinal recording media. The results also indicate that the Gd-substituted sample has maximum reflection loss of -25.2 dB at 11.878 GHz, can exhibit the best microwave absorption properties among all the substituted samples. Furthermore, the minimum value of reflection loss shifts towards the lower and higher frequencies with the substitution of rare earth elements which confirms that the microwave absorption properties can be tuned with the substitution of rare earth elements in pure ferrites. The peak value of attenuation constant at higher frequency agrees well the reflection loss data.

A multi proxy reconstruction of paleoproductivity of Cleland Lake British Columbia, Canada

NASA Astrophysics Data System (ADS)

Mihindukulasooriya, L. N.; Pompeani, D. P.; Ortiz, J. D.; Steinman, B. A.; Abbott, M. B.

2013-12-01

In small closed-basin lakes in semi arid regions, variations in precipitation/evaporation (P/E) balance affect the physical, biological, and chemical composition of the lake water and sediment. This study presents color reflectance, XRF derived elemental concentrations and δ18O values of carbonates (δ18Ocarb) in sediment cores from Cleland Lake, British Columbia to provide insight into paleolimnological variations during the past 7500 years. Principal Component (PC) 1 of the reflectance data, i.e, Illite+ sphalerite is used as a clay mineral proxy, and PC 4, diatoms+ cyanobacteria, is used as a paleoproductivity proxy. Lake paleoproductivity history is divided into three temporal periods, 400 to 2500 (denoted as P1), 2500 to 5000 (P2) and 5000 to 7500 (P3) calibrated years before present (Cal yr BP). Fe and Mn concentrations gradually increase during P3, reach high values during P2 and rapidly drop to the lowest values after 2600 Cal yr BP. Diatom abundances have a positive correlation with illite (r= 0.79, n=73 α=0.01) throughout the record. In contrast, negative correlations (table 1) exists between δ18Ocarb and diatom abundances during P2 and P3, indicating higher diatom abundance during wet periods. After 3000 cal yr BP, the correlation reverses (table 1), indicating low diatom abundance during wet periods. Variability in diatom abundances is greater than that of the δ18Ocarb values, indicating that factors other than the P/E balance affects phytoplankton abundance. P 1 is characterized by three periods (centered at 2500, 2100 and 1400 Cal yr BP) of predominantly low diatom abundance that occur simultaneously with low Mn and Cr concentrations. Low Mn and Cr levels may indicate intense reducing conditions, while the observed peaks in Ni and Cu concentration might indicate reducing conditions resulting from high rates of organic matter decomposition (Tribovillard et al., 2006). Contemporaneous with the abrupt δ18Ocarb depletion around 2600 Cal yr BP, trace metal concentrations (Fe, Cu, Ni and Zn) as well as nutrient (P, S) levels increase, suggesting a higher rate of groundwater inflow and mineral delivery. Despite these increases, diatom abundance remains low. This may indicate the competitive appearance of Cyanobacteria in place of diatoms. Three rapid increases in diatom abundances centered at 1500, 900 and 700 Cal yr BP are associated with peaks in Cr and δ18Ocarb. Cr enrichment and low Mn may indicate reducing conditions in the absence of free H2S (Tribovillard et al., 2006). Such conditions can develop due to restricted water mass renewal in a well stratified lake (Tribovillard et al., 2006). In contrast, around 900 Cal yr BP P, S and Si levels increase. Relatively high δ18Ocarb values at this time do not provide support for a groundwater associated inflow of nutrients to the lake. Therefore it is possible that this peak could have resulted from other climatic factors including higher wind speeds and a greater flux of fine clastic material.Table 1

Kinetics of C-reactive protein in children with congenital heart diseases in the early period after cardiosurgical treatment with extracorporeal circulation.

PubMed

Jaworski, Radoslaw; Haponiuk, Ireneusz; Irga-Jaworska, Ninela; Chojnicki, Maciej; Steffens, Mariusz; Szofer-Sendrowska, Aneta; Zielinski, Jacek; Juscinski, Jacek

2014-03-01

The aim of the study was to assess postoperative C-reactive protein (CRP) serum kinetics in children without clinical signs of infection after atrial and ventricular septal defects closure in terms of extracorporeal circulation (ECC). Fifty-two patients met inclusion criteria and were divided into 2 groups: group A (antibiotic prophylaxis with cefazolin given up to 48 h postoperatively) and group B (antibiotic prophylaxis with amoxicillin and clavunic acid given more than 48 h postoperatively). The CRP was measured perioperatively in both groups. The CRP evaluation was the part of routine lab-tests during perioperative period, without any modification of the typical perioperative strategy. In the postoperative period CRP was measured after 24h, 48 h, 72 h and 96 h in both groups. There were no differences between CRP levels between both groups of patients. The peak CRP values were observed after 48 h after the operation in ECC in both groups and decreased in the next postoperative days. In children with congenital heart defects undergoing cardiosurgical treatment with the use of ECC the assessing CRP values in the first postoperative day remains questionable. The maximum peak CRP value after operation with ECC can be much higher than the reference values without infection complications. Single CRP assessment in early postoperative period in these groups of children can lead to over-diagnosis of infections and antibiotics abuse. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Method of wavefront tilt correction for optical heterodyne detection systems under strong turbulence

NASA Astrophysics Data System (ADS)

Xiang, Jing-song; Tian, Xin; Pan, Le-chun

2014-07-01

Atmospheric turbulence decreases the heterodyne mixing efficiency of the optical heterodyne detection systems. Wavefront tilt correction is often used to improve the optical heterodyne mixing efficiency. But the performance of traditional centroid tracking tilt correction is poor under strong turbulence conditions. In this paper, a tilt correction method which tracking the peak value of laser spot on focal plane is proposed. Simulation results show that, under strong turbulence conditions, the performance of peak value tracking tilt correction is distinctly better than that of traditional centroid tracking tilt correction method, and the phenomenon of large antenna's performance inferior to small antenna's performance which may be occurred in centroid tracking tilt correction method can also be avoid in peak value tracking tilt correction method.

Sildenafil does not improve steady state cardiovascular hemodynamics, peak power, or 15-km time trial cycling performance at simulated moderate or high altitudes in men and women.

PubMed

Kressler, Jochen; Stoutenberg, Mark; Roos, Bernard A; Friedlander, Anne L; Perry, Arlette C; Signorile, Joseph F; Jacobs, Kevin A

2011-12-01

Sildenafil improves oxygen delivery and maximal exercise capacity at very high altitudes (≥ 4,350 m), but it is unknown whether sildenafil improves these variables and longer-duration exercise performance at moderate and high altitudes where competitions are more common. The purpose of this study was to determine the effects of sildenafil on cardiovascular hemodynamics, arterial oxygen saturation (SaO(2)), peak exercise capacity (W (peak)), and 15-km time trial performance in endurance-trained subjects at simulated moderate (MA; ~2,100 m, 16.2% F(I)O(2)) and high (HA; ~3,900 m, 12.8% F(I)O(2)) altitudes. Eleven men and ten women completed two HA W (peak) trials after ingesting placebo or 50 mg sildenafil. Subjects then completed four exercise trials (30 min at 55% of altitude-specific W (peak) + 15-km time trial) at MA and HA after ingesting placebo or 50 mg sildenafil. All trials were performed in randomized, counterbalanced, and double-blind fashion. Sildenafil had little influence on cardiovascular hemodynamics at MA or HA, but did result in higher SaO(2) values (+3%, p < 0.05) compared to placebo during steady state and time trial exercise at HA. W (peak) at HA was 19% lower than SL (p < 0.001) and was not significantly affected by sildenafil. Similarly, the significantly slower time trial performance at MA (28.1 ± 0.5 min, p = 0.016) and HA (30.3 ± 0.6 min, p < 0.001) compared to SL (27.5 ± 0.6 min) was unaffected by sildenafil. We conclude that sildenafil is unlikely to exert beneficial effects at altitudes <4,000 m for a majority of the population.

Mechanical efficiency of high versus moderate intensity aerobic exercise in coronary heart disease patients: A randomized clinical trial.

PubMed

Villelabeitia-Jaureguizar, Koldobika; Vicente-Campos, Davinia; Berenguel Senen, Alejandro; Verónica Hernández Jiménez, Verónica; Lorena Ruiz Bautista, Lorena; Barrios Garrido-Lestache, María Elvira; López Chicharro, Jose

2018-05-10

Mechanical efficiency (ME) refers to the ability of an individual to transfer energy consumed by external work. A decreased ME, could represent an increased energy cost during exercise and may, therefore, be limited in terms of physical activity. This study aimed to compare the influence of two different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients. 110 coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycle ergometer were performed to obtain VO₂peak. Net energy expenditure (EE) and ME were obtained at intensities corresponding to the first (VT₁) and second (VT₂) ventilatory thresholds, and at VO₂peak. Both exercise programs significantly increase VO₂peak with a higher increase in the HIIT group (2.96 ± 2.33 mL/kg/min vs. 3.88 ± 2.40 mL/kg/min, for patients of the MCT and HIIT groups respectively, p < 0.001). The ME at VO₂peak and VT₂ only significantly increased in the HIIT group. At VT₁, ME significantly increased in both groups, with a greater increase in the HIIT group (2.20 ± 6.25% vs. 5.52 ± 5.53%, for patients of the MCT and HIIT groups respectively, p < 0.001). The application of HIIT to patients with chronic ischemic heart disease of low risk resulted in a greater improvement in VO₂peak and in ME at VT₁, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT₂ and at VO₂peak.

Imaging surface nanobubbles at graphite-water interfaces with different atomic force microscopy modes.

PubMed

Yang, Chih-Wen; Lu, Yi-Hsien; Hwang, Ing-Shouh

2013-05-08

We have imaged nanobubbles on highly ordered pyrolytic graphite (HOPG) surfaces in pure water with different atomic force microscopy (AFM) modes, including the frequency-modulation, the tapping, and the PeakForce techniques. We have compared the performance of these modes in obtaining the surface profiles of nanobubbles. The frequency-modulation mode yields a larger height value than the other two modes and can provide more accurate measurement of the surface profiles of nanobubbles. Imaging with PeakForce mode shows that a nanobubble appears smaller and shorter with increasing peak force and disappears above a certain peak force, but the size returns to the original value when the peak force is reduced. This indicates that imaging with high peak forces does not cause gas removal from the nanobubbles. Based on the presented findings and previous AFM observations, the existing models for nanobubbles are reviewed and discussed. The model of gas aggregate inside nanobubbles provides a better explanation for the puzzles of the high stability and the contact angle of surface nanobubbles.

Measurement and Modeling of Acoustic Fields in a Gel Phantom at High Intensities

NASA Astrophysics Data System (ADS)

Canney, Michael S.; Bailey, Michael R.; Khokhlova, Vera A.; Crum, Lawrence A.

2006-05-01

The goal of this work was to compare measured and numerically predicted HIFU pressure waveforms in water and a tissue-mimicking phantom. Waveforms were measured at the focus of a 2-MHz HIFU transducer with a fiber optic hydrophone. The transducer was operated with acoustic powers ranging from 2W to 300W. A KZK-type equation was used for modeling the experimental conditions. Strongly asymmetric nonlinear waves with peak positive pressure up to 80 MPa and peak negative pressure up to 20 MPa were measured in water, while waves up to 50 MPa peak positive pressure and 15 MPa peak negative pressure were measured in tissue phantoms. The values of peak negative pressure corresponded well with numerical simulations and were significantly smaller than predicted by linear extrapolation from low-level measurements. The values of peak positive pressures differed only at high levels of excitation where bandwidth limitations of the hydrophone failed to fully capture the predicted sharp shock fronts.

Variable threshold method for ECG R-peak detection.

PubMed

Kew, Hsein-Ping; Jeong, Do-Un

2011-10-01

In this paper, a wearable belt-type ECG electrode worn around the chest by measuring the real-time ECG is produced in order to minimize the inconvenient in wearing. ECG signal is detected using a potential instrument system. The measured ECG signal is transmits via an ultra low power consumption wireless data communications unit to personal computer using Zigbee-compatible wireless sensor node. ECG signals carry a lot of clinical information for a cardiologist especially the R-peak detection in ECG. R-peak detection generally uses the threshold value which is fixed. There will be errors in peak detection when the baseline changes due to motion artifacts and signal size changes. Preprocessing process which includes differentiation process and Hilbert transform is used as signal preprocessing algorithm. Thereafter, variable threshold method is used to detect the R-peak which is more accurate and efficient than fixed threshold value method. R-peak detection using MIT-BIH databases and Long Term Real-Time ECG is performed in this research in order to evaluate the performance analysis.

The Concept of “Peak Ecological Water” in a Changing Climate. (Invited)

NASA Astrophysics Data System (ADS)

Gleick, P. H.

2009-12-01

In a paper prepared in 2008, Meena Palaniappan and Peter Gleick proposed the concept of "peak ecological water" as a way to characterize vulnerable watersheds in the context of human withdrawals and water use. The value that humans obtain from water produced through incremental increases in supply (e.g., drinking water, irrigation) can be compared with the declining value of the ecological services (e.g., water for plants and animals) that were being satisfied with this water. As more water is appropriated from watersheds the pace or severity of ecological disruptions increases. At a certain theoretical point, the value of ecological services provided by water is equivalent to the value of human services provided by water. After this point, increasing appropriation of water leads to ecological disruptions beyond the value that this increased water provides to humans (the slope of the decline in ecological services is greater than the slope of the increase in value to humans). At the point of "peak ecological water," society will maximize the ecological and human benefits provided by water. This concept will be presented here as a way to identify water resources at risks of overabstraction and overuse. Conversely, the concept can also help in identifying strategies to adapt to changing water availability due to climate change. A key challenge remains coming up with quantitative measures of peak ecological water and using those measures to develop policies to maintain ecological health under variable conditions Palaniappan, M. and P.H. Gleick. 2008. “Peak Water.” In The World’s Water 2008-2009 (P.H. Gleick, editor). Island Press, Washington, D.C. pp. 1-16.

Structural, thermal, dielectric spectroscopic and AC impedance properties of SiC nanoparticles doped PVK/PVC blend

NASA Astrophysics Data System (ADS)

Alghunaim, Naziha Suliman

2018-06-01

Nanocomposite films based on poly (N-vinylcarbazole)/polyvinylchloride (PVK/PVC) blend doped with different concentrations of Silicon Carbide (SiC) nanoparticles have been prepared. The X-ray diffraction, Ultra violet-visible spectroscopy, thermogravimetric analysis and electrical spectroscopic has been used to characterize these nanocomposites. The X-ray analysis confirms the semi-crystalline nature of the films. The intensity of the main X-ray peak is decreased due to the interaction between the PVK/PVC and SiC. The main SiC peaks are absent due to complete dissolution of SiC in polymeric matrices. The UV-Vis spectra indicated that the band gap optical energy is affected by adding SiC nanoparticles because the charges transfer complexes between PVK/PVC with amount of SiC. The thermal stability is improved and the estimated values of ε‧ and ε″ are increased with increasing for SiC content due to the free charge carriers which in turn increase the ionic conductivity of the doped samples. The plots of tan δ with frequency are studied. A single peak from the plot between tan δ and Log (f) is appeared and shifted towards the higher frequency confirmed the presence of relaxing dipoles moment.

Poly-beta-pinene, a Novel Nonconjugated Conductive Polymer

NASA Astrophysics Data System (ADS)

Thakur, Mrinal; Vippa, Prakash; Rajagopalan, Harish

2004-03-01

Electrical conductivity in a novel nonconjugated conductive polymer, poly-beta-pinene, has been measured as a function of iodine doping. The conductivity increases about ten orders of magnitude to a maximum value ˜ 0.01 S/cm. The molar concentration of iodine corresponding to saturation is ˜ 0.8. The optical absorption measurements after light doping have shown two peaks: one at 4.1 eV and the other at 3.1 eV. The first peak is due to the radical cation and the second due the charge-transfer between the double bond and the dopant. As observed in other nonconjugated conductive polymers, the second peak becomes broader and undergoes a red-shift upon higher doping [1,2]. The FTIR spectroscopic studies have shown that the C=C stretching vibration at 1610 cm-1 and the =C-H bending vibration band at 728 cm-1 decrease upon doping as observed in other nonconjugated conductive polymers. Preliminary measurements have shown large quadratic electro-optic effects in this material. 1. M. Thakur, J. Macromol. Sci.-PAC,2001,A38(12),1337. 2. M. Thakur, S. Khatavkar and E.J. Parish, J. Macromol. Sci.-PAC,2003,A40(12),1397.

Effects of indoor air pollution on lung function of primary school children in Kuala Lumpur

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

Azizi, B.H.; Henry, R.L.

1990-01-01

In a cross-sectional study of 7-12 year-old primary school children in Kuala Lumpur city, lung function was assessed by spirometric and peak expiratory flow measurements. Spirometric and peak expiratory flow measurements were successfully performed in 1,214 and 1,414 children, respectively. As expected, the main predictors of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and peak expiratory flow rate (PEFR) were standing height, weight, age, and sex. In addition, lung function values of Chinese and Malays were generally higher than those of Indians. In multiple regressionmore » models which included host and environmental factors, asthma was associated with significant decreases in FEV1, FEF25-75, and PEFR. However, family history of chest illness, history of allergies, low paternal education, and hospitalization during the neonatal period were not independent predictors of lung function. Children sharing rooms with adult smokers had significantly lower levels of FEF25-75. Exposures to wood or kerosene stoves were, but to mosquito repellents were not, associated with decreased lung function.« less

Effect of heating rate on thermoluminescence output of LiF: Mg, Ti (TLD-100) in dosimetric applications

NASA Astrophysics Data System (ADS)

Singh, Ranjit; Kainth, Harpreet Singh

2018-07-01

The luminiscence characteristics of thermoluminscence dosimeter LiF: Mg, Ti (TLD-100) irradiated to X-rays from 6 MV linac have been studied for wide range of 2-50 K/s readout linear heating rates. The reproducibility of glow curves for TLDs is found to be better at lower heating rates and depreciate at higher heating rates. The glow curve spectra were analysed using deconvolution procedure based on general-order kinetics. Shift in the peak maximum temperature per unit rise in heating rate for various peaks were found to decrease with heating rate. The TLDs irradiated with same dose exhibit decreasing TL counts with increase in the heating rate, which indicate the thermal quenching effect in TLD-100. The value of activation energy for each peak within the glow curve increases with heating rate. Calibration curves plotted for the dose range 0.4-1020 cGy exhibit decreasing slope with increasing readout heating rate. Corrections for temperature lag between the heating element and the dosimeter, and the effective heating rate (βeff) across the sample estimated using formulation proposed by Kitis and Tuyn and are found to be fairly applicable.

Investigation of optical properties of anthocyanin doped into sol-gel based matrix

NASA Astrophysics Data System (ADS)

Hashim, Hasrina; Abdul Aziz, Nik Mohd Azmi Nik; Isnin, Aishah

2012-06-01

Anthocyanin dye was extracted from petal of Hibiscus rosasinensis (Bunga Raya) and doped into sol-gel based matrix to investigate an effect of pH change on its optical properties. Sol-gel matrix based on Vinyl triethoxysilene (VTES) as a precursor was prepared through Sol-gel process at pH 7. The sol was doped with 0.1% of Anthocyanin and the same amount of dye was also dissolved in ethanol as a comparative sample. Hydrochloric Acid, HCl and Tetramethylammonium Hydroxide, TMAH were used to change the pH value by adding them at various concentrations into each sample. The emission spectra and chemical structures of the samples were measured by Spectrofluorometer and Fourier Transform Infrared (FTIR) respectively. When excited at 410 nm, two emission peaks at about 492 and 574 nm were observed for Anthocyanin in acidic environment both in ethanol and VTES sol. In base environment however, only Anthocyanin dissolved in ethanol produced emission peak with a single peak at about 539 nm. The sensitivity of Anthocyanin dye toward pH changes in VTES open a possibility to use it as sensing element in which sol-gel based matrix are known to have higher mechanical strength and thermal stability.

Neoclassical Toroidal Viscosity Torque Induced by Plasma Response in a Low- β Tokamak with Edge Pedestal

NASA Astrophysics Data System (ADS)

Yan, Xingting; Zhu, Ping; Sun, Youwen

2016-10-01

The characteristic profile and magnitude are predicted in theory for the neoclassical toroidal viscosity (NTV) torque induced by the plasma response to the resonant magnetic perturbation (RMP) in a tokamak with an edge pedestal, using the newly developed module coupling the NIMROD and the NTVTOK codes. For a low β equilibrium, the NTV torque is mainly induced by the dominant toroidal mode of plasma response. The NTV torque profile is radially localized and peaked, which is determined by profiles of both the equilibrium temperature and the plasma response fields. In general, the peak of NTV torque profile is found to trace the pedestal location. The magnitude of NTV torque is extremely sensitive to the β of pedestal top; for a given plasma response, the peak value of NTV torque can increase by three orders of magnitude, when the pedestal β increases by only one order of magnitude. This suggests a more significant role of NTV torque in higher plasma β regimes. Supported by the National Magnetic Confinement Fusion Program of China under Grant Nos. 2014GB124002 and 2015GB101004, and the 100 Talent Program of the Chinese Academy of Sciences.

Diagnostics of an AC driven atmospheric pressure non-thermal plasma jet and its use for radially directed jet array

NASA Astrophysics Data System (ADS)

Zhu, W.; Wang, R.

2017-08-01

An alternating current atmospheric pressure plasma jet is generated with noble gas or noble gas/oxygen admixture as working gas. A "core plasma filament" is observed at the center of the dielectric tube and extends to the plasma jet at higher peak-to-peak voltages. This type of plasma jet is believed to be of the same nature with the reported plasma bullet driven by pulsed DC power sources. Double current probes are used to assess the speed of the plasma bullet and show that the speed is around 104-105 m/s. The time dependence of the downstream bullet speed is attributed to the gas heating and in turn the increase of the reduced electric field E/N. Optical emission spectra show the dependence of helium and oxygen emission intensities on the concentration of oxygen additive in the carrier gas, with peak values found at 0.5% O2. Multiple radial jets are realized on dielectric tubes of different sizes. As a case study, one of these multi-jet devices is used to treat B. aureus on the inner surface of a plastic beaker and is shown to be more effective than a single jet.

Steam sterilization effect on the accuracy of friction-style mechanical torque limiting devices.

PubMed

Sadr, Seyed Jalil; Fayyaz, Ali; Mahshid, Minoo; Saboury, Aboulfazl; Ansari, Ghassem

2014-01-01

This study was aimed to evaluate the effect of steam sterilization on the accuracy (within 10%) of friction-style mechanical torque limiting devices (F-S MTLDs) to achieve their target torque values. Fifteen new F-S MTLDs were selected from Astra Tech (25 Ncm, Hader SA, La Chaux-de-Fonds, Switzerland), BioHorizons (30 Ncm, Dynatorq ITL, Irvine, California, USA), Dr. Idhe (15-60 Ncm, Dr. Idhe Dental, Eching/Munich, Germany). Every peak torque measurement was tested ten times before steam sterilization using Tohnichi torque gauge (6Tohnichi-BTG (-S), Japan). Steam sterilization was performed using a 100 cycle autoclave. Preparation steps were carried out for the devices before each autoclave sterilization cycle. Peak torque measurements were repeated after every sterilization cycle. Mean difference between the measured and the targeted torque values were evaluated before and after aging. Repeated-measures of ANOVA were used to compare the differences of accuracy between subjects. Bonferroni post-hoc test was used for pairwise comparison. Autoclaving resulted in an increase in the error values (the difference between peak torque and target torque values) in all the three groups studied (P < 0.05), with only Astra Tech devices showing >10% (maximum 12%) difference from their torque values in 5% of the measurements. Steam sterilization effect differs between target torque and measured peak values with an increase trend. The peak torque values showed a significant decrease for BioHorizons, while a significant increase was noted for Astra Tech and no significant change in Dr. Idhe group after sterilization. Within the limitation of this study the torque output of each individual device deviated in varying degrees from target torque values. However, the majority of the new frictional-style devices tested in this study, delivered fairly consistent torque output within 10% of their preset target values after sterilization. Astra Tech devices were the only one showing more than 10% difference from their torque values in 5% of the measurements. Combined effects of sterilization and aging still needs to be determined.

Comparison of vildagliptin and glimepiride: effects on glycaemic control, fat tolerance and inflammatory markers in people with type 2 diabetes.

PubMed

Derosa, G; Bonaventura, A; Bianchi, L; Romano, D; Fogari, E; D'Angelo, A; Maffioli, P

2014-12-01

To compare the effects of vildagliptin with those of glimepiride on glycaemic control, fat tolerance and inflammatory markers in people with Type 2 diabetes mellitus receiving metformin treatment. A total of 167 participants were randomized to vildagliptin 50 mg twice a day or glimepiride 2 mg three times a day, for 6 months. We evaluated the following variables: BMI; glycaemic control; fasting plasma insulin; homeostatic model assessment of insulin resistance index; fasting plasma proinsulin; glucagon; lipid profile; adiponectin; high-sensitivity C-reactive protein; interleukin-6; and tumour necrosis factor-α. A euglycaemic-hyperinsulinaemic clamp procedure and an oral fat load test were also performed. Despite a similar decrease in HbA1c levels (P = 0.009, and P = 0.008, respectively), body weight increased with glimepiride (P = 0.048 vs baseline) and decreased with vildagliptin (P = 0.041 vs baseline and vs glimepiride). Fasting plasma insulin and homeostatic model assessment of insulin resistance index were significantly lower with vildagliptin compared with glimepiride (P = 0.035 and 0.047). M value, an index of insulin sensitivity, increased with vildagliptin, both compared with baseline and with glimepiride (P = 0.028 and 0.039, respectively). Vildagliptin improved all post-oral fat load peaks of lipid profile compared with glimepiride. Adiponectin levels were higher (P = 0.035) and high-sensitivity C-reactive protein levels were lower (P = 0.038) with vildagliptin vs glimepiride. During the oral fat load test, interleukin-6, high-sensitivity C-reactive protein and tumour necrosis factor-α peaks were lower and adiponectin peak was higher in the vildagliptin group than in the glimepiride group. There was a higher dropout rate as a result of hypoglycaemia in the glimepiride group than in the vildagliptin group. Vildagliptin was more effective than glimepiride in reducing post-oral fat load peaks of lipid-trafficking adipocytokines and inflammatory markers. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

Lithium in a short-period tidally locked binary of M67: Implications for stellar evolution, Galactic Lithium evolution, and cosmology

NASA Technical Reports Server (NTRS)

Deliyannis, Constantine P.; King, Jeremy R.; Boesgaard, Ann M.; Ryan, Sean G.

1994-01-01

In open clusters, late-F stars exhibit a Li maximum (the Li 'peak' region) at lower abundance with age, which could be due either to stellar depletion or Galactic Li enrichment (or some other cause). We have observed a short-period tidally locked binary (SPTLB) on the Li peak region in the old cluster M67 to distinguish between alternatives. SPTLBs which synchronized in the early pre-main sequence would avoid the rotational mixing which, according to Yale models, may be responsible for depleting Li with age in open cluster dwarfs. We find that both components of the M67 SPTLB have a Li abundance lying about a factor of 2 or more above any other M67 single star and about a factor of 3 or more above the mean Li peak region abundance in M67. Our results suggest that the initial Li abundance in M67 is at least as high as approximately 3.0 = 12 + log (N(sub Li)/N(sub H)). Our high M67 SPTLB Li abundance and those in other clusters support the combination of Zahn's tidal circularization and the Yale rotational mixing theories and may indicate that the halo Li plateau (analogous to the cluster Li peak region) abundance has been depleted from a higher primordial value. Implications are discussed.

Cyclic variation in seasonal recruitment and the evolution of the seasonal decline in Ural owl clutch size.

PubMed Central

Brommer, Jon E; Pietiäinen, Hannu; Kokko, Hanna

2002-01-01

Plastic life-history traits can be viewed as adaptive responses to environmental conditions, described by a reaction norm. In birds, the decline in clutch size with advancing laying date has been viewed as a reaction norm in response to the parent's own (somatic or local environmental) condition and the seasonal decline in its offspring's reproductive value. Theory predicts that differences in the seasonal recruitment are mirrored in the seasonal decrease in clutch size. We tested this prediction in the Ural owl. The owl's main prey, voles, show a cycle of low, increase and peak phases. Recruitment probability had a humped distribution in both increase and peak phases. Average recruitment probability was two to three times higher in the increase phase and declined faster in the latter part of the season when compared with the peak phase. Clutch size decreased twice as steep in the peak (0.1 eggs day-1) as in the increase phase (0.05 eggs day-1). This result appears to refute theoretical predictions of seasonal clutch size declines. However, a re-examination of current theory shows that the predictions of modelling are less robust to details of seasonal condition accumulation in birds than originally thought. The observed pattern can be predicted, assuming specifically shaped seasonal increases in condition across individuals. PMID:11916482

Rate of muscle contraction is associated with cognition in women, not in men.

PubMed

Tian, Qu; Osawa, Yusuke; Resnick, Susan M; Ferrucci, Luigi; Studenski, Stephanie A

2018-05-08

In older persons, lower hand grip strength is associated with poorer cognition. Little is known about how the rate of muscle contraction relates to cognition and upper extremity motor function, and sex differences are understudied. Linear regression, adjusting for age, race, education, body mass index, appendicular lean mass, and knee pain assessed sex-specific cross-sectional associations of peak torque, rate of torque development (RTD) and rate of velocity development (RVD) with cognition and upper extremity motor function. In men (n=447), higher rate-adjusted peak torque and a greater RVD were associated with faster simple finger tapping speed, and a greater RVD was associated with higher nondominant pegboard performance. In women (n=447), higher peak torque was not associated with any measures, but a greater RTD was associated with faster simple tapping speed and higher language performance, and a greater RVD was associated with higher executive function, attention, memory, and nondominant pegboard performance. In women with low isokinetic peak torque, RVD was associated with attention and memory. RVD capacity may reflect neural health, especially in women with low muscle strength.

GeV-scale dark matter: Production at the main injector

DOE PAGES

Dobrescu, Bogdan A.; Frugiuele, Claudia

2015-02-03

In this study, assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z' boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NOνA near detectormore » is well positioned for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.« less

Directional effects on NDVI and LAI retrievals from MODIS: A case study in Brazil with soybean

NASA Astrophysics Data System (ADS)

Breunig, Fábio Marcelo; Galvão, Lênio Soares; Formaggio, Antônio Roberto; Epiphanio, José Carlos Neves

2011-02-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) is largely used to estimate Leaf Area Index (LAI) using radiative transfer modeling (the "main" algorithm). When this algorithm fails for a pixel, which frequently occurs over Brazilian soybean areas, an empirical model (the "backup" algorithm) based on the relationship between the Normalized Difference Vegetation Index (NDVI) and LAI is utilized. The objective of this study is to evaluate directional effects on NDVI and subsequent LAI estimates using global (biome 3) and local empirical models, as a function of the soybean development in two growing seasons (2004-2005 and 2005-2006). The local model was derived from the pixels that had LAI values retrieved from the main algorithm. In order to keep the reproductive stage for a given cultivar as a constant factor while varying the viewing geometry, pairs of MODIS images acquired in close dates from opposite directions (backscattering and forward scattering) were selected. Linear regression relationships between the NDVI values calculated from these two directions were evaluated for different view angles (0-25°; 25-45°; 45-60°) and development stages (<45; 45-90; >90 days after planting). Impacts on LAI retrievals were analyzed. Results showed higher reflectance values in backscattering direction due to the predominance of sunlit soybean canopy components towards the sensor and higher NDVI values in forward scattering direction due to stronger shadow effects in the red waveband. NDVI differences between the two directions were statistically significant for view angles larger than 25°. The main algorithm for LAI estimation failed in the two growing seasons with gradual crop development. As a result, up to 94% of the pixels had LAI values calculated from the backup algorithm at the peak of canopy closure. Most of the pixels selected to compose the 8-day MODIS LAI product came from the forward scattering view because it displayed larger LAI values than the backscattering. Directional effects on the subsequent LAI retrievals were stronger at the peak of the soybean development (NDVI values between 0.70 and 0.85). When the global empirical model was used, LAI differences up to 3.2 for consecutive days and opposite viewing directions were observed. Such differences were reduced to values up to 1.5 with the local model. Because of the predominance of LAI retrievals from the MODIS backup algorithm during the Brazilian soybean development, care is necessary if one considers using these data in agronomic growing/yield models.

Ionospheric Peak Electron Density and Performance Evaluation of IRI-CCIR Near Magnetic Equator in Africa During Two Extreme Solar Activities

NASA Astrophysics Data System (ADS)

Adebesin, B. O.; Rabiu, A. B.; Obrou, O. K.; Adeniyi, J. O.

2018-03-01

The F2 layer peak electron density (NmF2) was investigated over Korhogo (Geomagnetic: 1.26°S, 67.38°E), a station near the magnetic equator in the African sector. Data for 1996 and 2000 were, respectively, categorized into low solar quiet and disturbed and high solar quiet and disturbed. NmF2 prenoon peak was higher than the postnoon peak during high solar activity irrespective of magnetic activity condition, while the postnoon peak was higher for low solar activity. Higher NmF2 peak amplitude characterizes disturbed magnetic activity than quiet magnetic condition for any solar activity. The maximum peaks appeared in equinox. June solstice noontime bite out lagged other seasons by 1-2 h. For any condition of solar and magnetic activities, the daytime NmF2 percentage variability (%VR) measured by the relative standard deviation maximizes/minimizes in June solstice/equinox. Daytime variability increases with increasing magnetic activity. The highest peak in the morning time NmF2 variability occurs in equinox, while the highest evening/nighttime variability appeared in June solstice for all solar/magnetic conditions. The nighttime annual variability amplitude is higher during disturbed than quiet condition regardless of solar activity period. At daytime, variability is similar for all conditions of solar activities. NmF2 at Korhogo is well represented on the International Reference Ionosphere-International Radio Consultative Committee (IRI-CCIR) option. The model/observation relationship performed best between local midnight and postmidnight period (00-08 LT). The noontime trough characteristics is not prominent in the IRI pattern during high solar activity but evident during low solar conditions when compared with Korhogo observations. The Nash-Sutcliffe coefficients revealed better model performance during disturbed activities.

Parameters of triggered-lightning flashes in Florida and Alabama

NASA Astrophysics Data System (ADS)

Fisher, R. J.; Schnetzer, G. H.; Thottappillil, R.; Rakov, V. A.; Uman, M. A.; Goldberg, J. D.

1993-12-01

Channel base currents from triggered lightning were measured at the NASA Kennedy Space Center, Florida, during summer 1990 and at Fort McClellan, Alabama, during summer 1991. Additionally, 16-mm cinematic records with 3- or 5-ms resolution were obtained for all flashes, and streak camera records were obtained for three of the Florida flashes. The 17 flashes analyzed here contained 69 strokes, all lowering negative charge from cloud to ground. Statistics on interstroke interval, no-current interstroke interval, total stroke duration, total stroke charge, total stroke action integral (∫ i2dt), return stroke current wave front characteristics, time to half peak value, and return stroke peak current are presented. Return stroke current pulses, characterized by rise times of the order of a few microseconds or less and peak values in the range of 4 to 38 kA, were found not to occur until after any preceding current at the bottom of the lightning channel fell below the noise level of less than 2 A. Current pulses associated with M components, characterized by slower rise times (typically tens to hundreds of microseconds) and peak values generally smaller than those of the return stroke pulses, occurred during established channel current flow of some tens to some hundreds of amperes. A relatively strong positive correlation was found between return stroke current average rate of rise and current peak. There was essentially no correlation between return stroke current peak and 10-90% rise time or between return stroke peak and the width of the current waveform at half of its peak value. Parameters of the lightning flashes triggered in Florida and Alabama are similar to each other but are different from those of triggered lightning recorded in New Mexico during the 1981 Thunderstorm Research International Program. Continuing currents that follow return stroke current peaks and last for more than 10 ms exhibit a variety of wave shapes that we have subdivided into four categories. All such continuing currents appear to start with a current pulse presumably associated with an M component. A brief summary of lightning parameters important for lightning protection, in a form convenient for practical use, is presented in an appendix.

Oxygen uptake efficiency slope and peak oxygen consumption predict prognosis in children with tetralogy of Fallot.

PubMed

Tsai, Yun-Jeng; Li, Min-Hui; Tsai, Wan-Jung; Tuan, Sheng-Hui; Liao, Tin-Yun; Lin, Ko-Long

2016-07-01

Oxygen uptake efficiency slope (OUES) and peak oxygen consumption (VO2peak) are exercise parameters that can predict cardiac morbidity in patients with numerous heart diseases. But the predictive value in patients with tetralogy of Fallot is still undetermined, especially in children. We evaluated the prognostic value of OUES and VO2peak in children with total repair of tetralogy of Fallot. Retrospective cohort study. Forty tetralogy of Fallot patients younger than 12 years old were recruited. They underwent a cardiopulmonary exercise test during the follow-up period after total repair surgery. The results of the cardiopulmonary exercise test were used to predict the cardiac related hospitalization in the following two years after the test. OUES normalized by body surface area (OUES/BSA) and the percentage of predicted VO2peak appeared to be predictive for two-year cardiac related hospitalization. Receiver operating characteristic curve analysis demonstrated that the best threshold value for OUES/BSA was 1.029 (area under the curve = 0.70, p = 0.03), and for VO2peak was 74% of age prediction (area under the curve = 0.72, p = 0.02). The aforementioned findings were confirmed by Kaplan-Meier plots and log-rank test. OUES/BSA and VO2peak are useful predictors of cardiac-related hospitalization in children with total repair of tetralogy of Fallot. © The European Society of Cardiology 2015.

Preliminary analysis of strong-motion recordings from the 28 September 2004 Parkfield, California earthquake

USGS Publications Warehouse

Shakal, A.; Graizer, V.; Huang, M.; Borcherdt, R.; Haddadi, H.; Lin, K.-W.; Stephens, C.; Roffers, P.

2005-01-01

The Parkfield 2004 earthquake yielded the most extensive set of strong-motion data in the near-source region of a magnitude 6 earthquake yet obtained. The recordings of acceleration and volumetric strain provide an unprecedented document of the near-source seismic radiation for a moderate earthquake. The spatial density of the measurements alon g the fault zone and in the linear arrays perpendicular to the fault is expected to provide an exceptional opportunity to develop improved models of the rupture process. The closely spaced measurements should help infer the temporal and spatial distribution of the rupture process at much higher resolution than previously possible. Preliminary analyses of the peak a cceleration data presented herein shows that the motions vary significantly along the rupture zone, from 0.13 g to more than 2.5 g, with a map of the values showing that the larger values are concentrated in three areas. Particle motions at the near-fault stations are consistent with bilateral rupture. Fault-normal pulses similar to those observed in recent strike-slip earthquakes are apparent at several of the stations. The attenuation of peak ground acceleration with distance is more rapid than that indicated by some standard relationships but adequately fits others. Evidence for directivity in the peak acceleration data is not strong. Several stations very near, or over, the rupturing fault recorded relatively low accelerations. These recordings may provide a quantitative basis to understand observations of low near-fault shaking damage that has been reported in other large strike-slip earthquak.

Performance of coagulation tests in patients on therapeutic doses of rivaroxaban. A cross-sectional pharmacodynamic study based on peak and trough plasma levels.

PubMed

Francart, Suzanne J; Hawes, Emily M; Deal, Allison M; Adcock, Dorothy M; Gosselin, Robert; Jeanneret, Cheryl; Friedman, Kenneth D; Moll, Stephan

2014-06-01

Knowledge of anticoagulation status during rivaroxaban therapy is desirable in certain clinical situations. It was the study objective to determine coagulation tests most useful for assessing rivaroxaban's anticoagulant effect. Peak and trough blood samples from 29 patients taking rivaroxaban 20 mg daily were collected. Mass spectrometry and various coagulation assays were performed. "On-therapy range" was defined as the rivaroxaban concentrations determined by LC-MS/MS. A "misprediction percentage" was calculated based on how often results of each coagulation assay were in the normal reference range, while the rivaroxaban concentration was in the "on-therapy" range. The on-therapy range was 8.9-660 ng/ml. The misprediction percentages for prothrombin time (PT) and activated partial thromboplastin time (aPTT), using multiple reagents and coagulometers, ranged from 10%-52% and 31%-59%, respectively. PT, aPTT and activated clotting time (ACT) were insensitive to trough rivaroxaban: 59%, 62%, and 80% of samples had a normal result, respectively. Over 95% of PT and ACT values were elevated at peak. Four different rivaroxaban calibrated anti-Xa assays had R² values >0.98, demonstrating strong correlations with rivaroxaban drug levels. In conclusion, PT, aPTT and ACT are often normal in patients on therapeutic doses of rivaroxaban. However, PT and ACT may have clinical utility at higher drug plasma levels. Rivaroxaban calibrated anti-factor Xa assays can accurately identify low and high on-therapy rivaroxaban drug levels and, therefore, have superior utility in all clinical situations where assessment of anticoagulation status may be beneficial.

Capillary isoelectric focusing with whole column imaging detection (iCIEF): A new approach to the characterization and quantification of salivary α-amylase.

PubMed

Zarabadi, Atefeh S; Huang, Tiemin; Mielke, John G

2017-05-15

Saliva is an easily collected biological fluid with potentially important diagnostic value. While gel electrophoresis is generally used for salivary analysis, we employed the capillary isoelectric focusing technique to allow for a rapid, automated mode of electrophoresis. Capillary isoelectric focusing coupled with UV whole column imaging detection (iCIEF) was used to develop a robust protocol to characterize salivary α-amylase collected from various glands. Notably, three sample preparation methods were examined: ultrafiltration, gel-filtration, and starch affinity interaction with salivary amylase. Salivary α-amylase separated into two major peaks before sample treatment; while both filtration methods and starch affinity interaction of salivary amylase enhanced the resolution of isozymes, desalting with gel-filtration displayed the best recovery and the highest resolution of isozymes. Good agreement existed between the observed isoelectric points and the values reported in the literature. In addition, a high level of precision was apparent, and the relative standard deviation for replicates was less than 0.5% for pIs (peak positions) and below 10% for peak area. Furthermore, saliva secreted from the parotid gland proved to have a higher amylase content compared to either secretions from the submandibular/sublingual complex, or whole saliva, as well as amylase enhancement under stimulation. The results suggest that the iCIEF technique can be used to accurately resolve and quantitate amylase isozymes in a rapid and automated fashion, and that gel-filtration should be applied to saliva samples beforehand to allow for optimal purification and characterization. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular spectroscopic features of protein in newly developed chickpea: Relationship with protein chemical profile and metabolism in the rumen and intestine of dairy cows.

PubMed

Sun, Baoli; Khan, Nazir Ahmad; Yu, Peiqiang

2018-05-05

The first aim of this study was to investigate the nutritional value of crude protein (CP) in CDC [Crop Development Centre (CDC), University of Saskatchewan] chickpea varieties (Frontier kabuli and Corinne desi) in comparison with a CDC barley variety in terms of: 1) CP chemical profile and subfractions; (2) in situ rumen degradation kinetics and intestinal digestibility of CP; 2) metabolizable protein (MP) supply to dairy cows; and (3) protein molecular structure characteristics using advanced molecular spectroscopy. The second aim was to quantify the relationship between protein molecular spectral characteristics and CP subfractions, in situ rumen CP degradation characteristics, intestinal digestibility of CP, and MP supply to dairy cows. Samples (n=4) of each variety, from two consecutive years were analyzed. Chickpeas had higher (P<0.01) CP content (21.71-22.11 vs 12.96% DM), with higher (P<0.05) soluble CP subfraction (59.07-70.27 vs 26.18% CP), and in situ soluble (23.44-25.85 vs 1.30% CP) and rumen degradable (RDP; 72.23-72.57 vs 58.48% CP) fractions than barley. The potentially slowly rumen degradable (D; 74.14-76.56 vs 93.31% CP) and undegradable (RUP; 27.43-27.66 vs 41.52% CP) fractions were lower (P<0.01) in the chickpeas than barley. The effective degradability ratio of N to organic matter (OM) (36.07-38.44gN/kg OM) of the chickpeas was higher than the optimal for achieving optimum microbial CP (MCP) synthesis. The truly digested MCP (64.94-66.43 vs. 41.43g/kg DM); MP (81.10-83.67 vs 61.0g/kg DM) feed milk value (1.64-1.70 vs 1.24) was higher in the chickpeas than barley grain. The chickpeas had higher (P<0.05) amide I and II peaks area and height, and α-helix and β-sheet peaks height than barley. Multivariate analysis showed that protein molecular spectral data of chickpeas can be distinguished from the barley. The two chickpeas did not differ in CP content, and any of the measured in situ degradation and molecular spectral characteristics of protein. The content of RUP was positively (r=0.94, P<0.01) and that of RDP was negatively (r=-0.94, P<0.01) correlated with amide I/II area ratio. The regression analysis showed that the content of CP (R2=0.91) D-fraction (R 2 =0.82), RDP (R 2 =0.77), RUP (R 2 =0.77), TDP (R 2 =0.98), MP (R 2 =0.80), and FMV (R 2 =0.80) can be predicted from amide II peak height. Despite extensive ruminal degradation, chickpea is a good source of MP for dairy cows, and molecular spectroscopy can be used to rapidly characterize feed protein molecular structures and predict their digestibility and nutritive value. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

[Comparative GC analysis of essential oil in imported sandalwood].

PubMed

Wang, Z; Hong, X

1991-01-01

The GC-fingerprint spectra of essential oils in imported sandalwood are established by the new technique of GC-relative retention value fingerprint spectrum (GC-FPS). According to the GC-FPS of samples, their chromatographic peaks, overlap ratio of peaks and eight strong peaks are studied comparatively.

Cathodoluminescence study on local high-energy emissions at dark spots in AlGaN/AlGaN multiple quantum wells

NASA Astrophysics Data System (ADS)

Kurai, Satoshi; Imura, Nobuto; Jin, Li; Miyake, Hideto; Hiramatsu, Kazumasa; Yamada, Yoichi

2018-06-01

We investigated the spatial distribution of luminescence near threading dislocations in AlGaN/AlGaN multiple quantum wells (MQWs) by cathodoluminescence mapping. Emission at the higher-energy side of the AlGaN MQW peak was locally observed near the threading dislocations, which were not accompanied by any surface V-pits. Such higher-energy emission was not observed in the AlGaN epilayers. The energy difference between the AlGaN MQW peak and the higher-energy emission peak increased with increasing barrier-layer Al composition. These results suggest that the origin of the higher-energy emission is likely local thickness fluctuation around dislocations in very thin AlGaN MQWs.

Revisiting the accuracy of peak flow meters: a double-blind study using formal methods of agreement.

PubMed

Nazir, Z; Razaq, S; Mir, S; Anwar, M; Al Mawlawi, G; Sajad, M; Shehab, A; Taylor, R S

2005-05-01

There is widespread use of peak flow meters in both hospitals and general practice. Previous studies to assess peak flow meter accuracy have shown significant differences in the values obtained from different meters. However, many of these studies did not use human subjects for peak flow measurements and did not compare meters of varying usage. In this study human subjects have been used with meters of varying usage. Participants were tested using two new (meters A and C) and one old peak flow meter (meter B) in random order. The study was double-blinded. Participants were recruited from the university campus. Four hundred and nine individuals participated. The difference between peak flow means of A and B was -9.93 l/min (95% CI: -12.37 to -7.48, P<0.0001). The difference between peak flow means of B and C was 20.08 l/min (95% CI: 17.85-22.29, P<0.0001). The difference between peak flow means of A and C was 10.15 l/min (95% CI: 7.68-12.61, P<0.0001). There was a significant difference between the values obtained from the new and old peak flow meters and also between the two new peak flow meters. We conclude that there is need for caution in interchangeably using flow meters in clinical practice.

Geomorphic effectiveness of long profile shape and role of inherent geological controls, Ganga River Basin, India

NASA Astrophysics Data System (ADS)

Sonam, Sonam; Jain, Vikrant

2017-04-01

River long profile is one of the fundamental geomorphic parameters which provides a platform to study interaction of geological and geomorphic processes at different time scales. Long profile shape is governed by geological processes at 10 ^ 5 - 10 ^ 6 years' time scale and it controls the modern day (10 ^ 0 - 10 ^ 1 years' time scale) fluvial processes by controlling the spatial variability of channel slope. Identification of an appropriate model for river long profile may provide a tool to analyse the quantitative relationship between basin geology, profile shape and its geomorphic effectiveness. A systematic analysis of long profiles has been carried for the Himalayan tributaries of the Ganga River basin. Long profile shape and stream power distribution pattern is derived using SRTM DEM data (90 m spatial resolution). Peak discharge data from 34 stations is used for hydrological analysis. Lithological variability and major thrusts are marked along the river long profile. The best fit of long profile is analysed for power, logarithmic and exponential function. Second order exponential function provides the best representation of long profiles. The second order exponential equation is Z = K1*exp(-β1*L) + K2*exp(-β2*L), where Z is elevation of channel long profile, L is the length, K and β are coefficients of the exponential function. K1 and K2 are the proportion of elevation change of the long profile represented by β1 (fast) and β2 (slow) decay coefficients of the river long profile. Different values of coefficients express the variability in long profile shapes and is related with the litho-tectonic variability of the study area. Channel slope of long profile is estimated taking the derivative of exponential function. Stream power distribution pattern along long profile is estimated by superimposing the discharge and long profile slope. Sensitivity analysis of stream power distribution with decay coefficients of the second order exponential equation is evaluated for a range of coefficient values. Our analysis suggests that the amplitude of stream power peak value is dependent on K1, the proportion of elevation change coming under the fast decay exponent and the location of stream power peak is dependent of the long profile decay coefficient (β1). Different long profile shapes owing to litho-tectonic variability across the Himalayas are responsible for spatial variability of stream power distribution pattern. Most of the stream power peaks lie in the Higher Himalaya. In general, eastern rivers have higher stream power in hinterland area and low stream power in the alluvial plains. This is responsible for, 1) higher erosion rate and sediment supply in hinterland of eastern rivers, 2) the incised and stable nature of channels in the western alluvial plains and 3) aggrading channels with dynamic nature in the eastern alluvial plains. Our study shows that the spatial variability of litho-units defines the coefficients of long profile function which in turn controls the position and magnitude of stream power maxima and hence the geomorphic variability in a fluvial system.

Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the northwestern Mediterranean Sea, influence of the Rhône River

NASA Astrophysics Data System (ADS)

Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

2010-12-01

Seawater samples were collected monthly in surface waters (2 and 5 m depths) of the Bay of Marseilles (northwestern Mediterranean Sea; 5°17'30" E, 43°14'30" N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events might reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peaks C and A). Besides Rhône River plumes, mixing events of the entire water column injected relative aged (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties, within the hydrological context, pointed out several biotic (in situ biological production, biological production within Rhône River plumes) and abiotic (photobleaching, mixing) factors controlling CDOM transport, production and removal in this highly urbanized coastal area.

Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

NASA Astrophysics Data System (ADS)

Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

2010-07-01

Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17'30'' E, 43°14'30'' N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) with in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events may reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peak C). Besides Rhône River plumes, mixing events of the entire water column injected humic (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties, within the hydrological context, pointed out several biotic (in situ biological production, biological production within Rhône River plumes) and abiotic (photobleaching, mixing) factors controlling CDOM transport, production and removal in this highly urbanized coastal area.

Flux-lattice melting, anisotropy, and the role of interlayer coupling in Bi-Sr-Ca-Cu-O single crystals

NASA Astrophysics Data System (ADS)

Duran, C.; Yazyi, J.; de La Cruz, F.; Bishop, D. J.; Mitzi, D. B.; Kapitulnik, A.

1991-10-01

We have used the high-Q mechanical-oscillator technique to probe the vortex-lattice structure in high-quality Bi-Sr-Ca-Cu-O single crystals over a wide range of magnetic fields (200 Oe to 40 kOe), and relative orientations θ between the magnetic field and the crystalline c^ axis. In addition to the large softening and dissipation peak previously observed and interpreted as due to flux-lattice melting, another distinctly different peak at higher temperatures is seen. The temperatures where the dissipation peaks take place are solely defined by the parallel component of the field cosθ, while the restoring force on the oscillator is due to both field components. We suggest that the two peaks are due to the softening of interplanar coupling at the low-temperature peak, and melting or depinning of the two-dimensional pancake vortices at the higher-temperature peak.