Gamma-unstable nuclei in the sdg boson model

NASA Astrophysics Data System (ADS)

Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barret, B. R.

Following the recent Pt(p,p') experiments which indicated the need for high angular momentum (g) bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a gamma-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the gamma-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4(sup +) states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes.

Effect of Stress Triaxiality on the Flow and Fracture of Mg Alloy AZ31

NASA Astrophysics Data System (ADS)

Kondori, Babak; Benzerga, A. Amine

2014-07-01

The microscopic damage mechanisms operating in a hot-rolled magnesium alloy AZ31B are investigated under both uniaxial and controlled triaxial loadings. Their connection to macroscopic fracture strains and fracture mode (normal vs shear) is elucidated using postmortem fractography, interrupted tests, and microscopic analysis. The fracture locus (strain-to-failure vs stress triaxiality) exhibits a maximum at moderate triaxiality, and the strain-to-failure is found to be greater in notched specimens than in initially smooth ones. A transition from twinning-induced fracture under uniaxial loading to microvoid coalescence fracture under triaxial loading is evidenced. It is argued that this transition accounts in part for the observed greater ductility in notched bars. The evolution of plastic anisotropy with stress triaxiality is also investigated. It is inferred that anisotropic plasticity at a macroscopic scale suffices to account for the observed transition in the fracture mode from flat (triaxial loading) to shear-like (uniaxial loading). Damage is found to initiate at second-phase particles and deformation twins. Fracture surfaces of broken specimens exhibit granular morphology, coarse splits, twin-sized crack traces, as well as shallow and deep dimples, in proportions that depend on the overall stress triaxiality and fracture mode. An important finding is that AZ31B has a greater tolerance to ductile damage accumulation than has been believed thus far, based on the fracture behavior in uniaxial specimens. Another finding, common to both tension and compression, is the increase in volumetric strain, the microscopic origins of which remain to be elucidated.

Agent-based modeling of physical activity behavior and environmental correlations: an introduction and illustration.

PubMed

Zhu, Weimo; Nedovic-Budic, Zorica; Olshansky, Robert B; Marti, Jed; Gao, Yong; Park, Youngsik; McAuley, Edward; Chodzko-Zajko, Wojciech

2013-03-01

To introduce Agent-Based Model (ABM) to physical activity (PA) research and, using data from a study of neighborhood walkability and walking behavior, to illustrate parameters for an ABM of walking behavior. The concept, brief history, mechanism, major components, key steps, advantages, and limitations of ABM were first introduced. For illustration, 10 participants (age in years: mean = 68, SD = 8) were recruited from a walkable and a nonwalkable neighborhood. They wore AMP 331 triaxial accelerometers and GeoLogger GPA tracking devices for 21 days. Data were analyzed using conventional statistics and highresolution geographic image analysis, which focused on a) path length, b) path duration, c) number of GPS reporting points, and d) interaction between distances and time. Average steps by subjects ranged from 1810-10,453 steps per day (mean = 6899, SD = 3823). No statistical difference in walking behavior was found between neighborhoods (Walkable = 6710 ± 2781, Nonwalkable = 7096 ± 4674). Three environment parameters (ie, sidewalk, crosswalk, and path) were identified for future ABM simulation. ABM should provide a better understanding of PA behavior's interaction with the environment, as illustrated using a real-life example. PA field should take advantage of ABM in future research.

Study on the Particle Size Distribution Nano-Particles of Mining Minerals on Whiteness of Triaxial Body

NASA Astrophysics Data System (ADS)

Mathur, Ravi; Soni, Aditi

White wares produced worldwide represent the foundation of much of the ceramic industry; Porcelain bodies fabricated from triaxial mixtures of clay, quartz and feldspar with different size and amounts of nano particles were investigated. Although the purity of raw materials has a strong effect on the colour of the fired bodies, the particle size of raw materials also effect the whiteness The raw material mining minerals china Clay, Feldspar, quarts were prepared of various sized nano particles contains 10.60 -20.22%, 56.84- 70.80 % and 34.87-50.76 % of 100nm respectively. The fired bodies of raw mining minerals and triaxial bodies were subjected to colour measurement. The differences in whiteness were compared and discussed. The studies so far carried out is upto 400 mesh size while the present study has included up to 100nm particle size. A statistical correlation between whiteness of feldspar and triaxial body was also carried out. The correlation between china clay and triaxial body are 0.53, 0.57 and 0.66 for china clay similarly correlation for feldspar is 0.49, 0.73 and 0.83 for triaxial body it are 0.97, 0.84 and 0.75 for A1, A2 and A3 samples. Correlation between china clay and feldspar with triaxial body are 0.79 and 0.92 respectively.

Theoretical study of triaxial shapes of neutron-rich Mo and Ru nuclei

DOE PAGES

Zhang, C. L.; Bhat, G. H.; Nazarewicz, W.; ...

2015-09-10

Here, whether atomic nuclei can possess triaxial shapes at their ground states is still a subject of ongoing debate. According to theory, good prospects for low-spin triaxiality are in the neutron-rich Mo-Ru region. Recently, transition quadrupole moments in rotational bands of even-mass neutron-rich isotopes of molybdenum and ruthenium nuclei have been measured. The new data have provided a challenge for theoretical descriptions invoking stable triaxial deformations. The purpose of this study is to understand experimental data on rotational bands in the neutron-rich Mo-Ru region, we carried out theoretical analysis of moments of inertia, shapes, and transition quadrupole moments of neutron-richmore » even-even nuclei around 110Ru using self-consistent mean-field and shell model techniques. Methods: To describe yrast structures in Mo and Ru isotopes, we use nuclear density functional theory (DFT) with the optimized energy density functional UNEDF0. We also apply triaxial projected shell model (TPSM) to describe yrast and positive-parity, near-yrast band structures. As a result, our self-consistent DFT calculations predict triaxial ground-state deformations in 106,108Mo and 108,110,112Ru and reproduce the observed low-frequency behavior of moments of inertia. As the rotational frequency increases, a negative-gamma structure, associated with the aligned ν(h 11/2) 2 pair, becomes energetically favored. The computed transition quadrupole moments vary with angular momentum, which reflects deformation changes with rotation; those variations are consistent with experiment. The TPSM calculations explain the observed band structures assuming stable triaxial shapes. Lastly, the structure of neutron-rich even-even nuclei around Ru-110 is consistent with triaxial shape deformations. Our DFT and TPSM frameworks provide a consistent and complementary description of experimental data.« less

Kinematic variability, fractal dynamics and local dynamic stability of treadmill walking

PubMed Central

2011-01-01

Background Motorized treadmills are widely used in research or in clinical therapy. Small kinematics, kinetics and energetics changes induced by Treadmill Walking (TW) as compared to Overground Walking (OW) have been reported in literature. The purpose of the present study was to characterize the differences between OW and TW in terms of stride-to-stride variability. Classical (Standard Deviation, SD) and non-linear (fractal dynamics, local dynamic stability) methods were used. In addition, the correlations between the different variability indexes were analyzed. Methods Twenty healthy subjects performed 10 min TW and OW in a random sequence. A triaxial accelerometer recorded trunk accelerations. Kinematic variability was computed as the average SD (MeanSD) of acceleration patterns among standardized strides. Fractal dynamics (scaling exponent α) was assessed by Detrended Fluctuation Analysis (DFA) of stride intervals. Short-term and long-term dynamic stability were estimated by computing the maximal Lyapunov exponents of acceleration signals. Results TW did not modify kinematic gait variability as compared to OW (multivariate T2, p = 0.87). Conversely, TW significantly modified fractal dynamics (t-test, p = 0.01), and both short and long term local dynamic stability (T2 p = 0.0002). No relationship was observed between variability indexes with the exception of significant negative correlation between MeanSD and dynamic stability in TW (3 × 6 canonical correlation, r = 0.94). Conclusions Treadmill induced a less correlated pattern in the stride intervals and increased gait stability, but did not modify kinematic variability in healthy subjects. This could be due to changes in perceptual information induced by treadmill walking that would affect locomotor control of the gait and hence specifically alter non-linear dependencies among consecutive strides. Consequently, the type of walking (i.e. treadmill or overground) is important to consider in each protocol design. PMID:21345241

Measuring the triaxial load-deformation response of orthotropic materials subjected to large and small strain regimes

Treesearch

Edmond P. Saliklis; Steven M. Cramer; John C. Hermanson

1998-01-01

A new method for obtaining triaxial stress versus strain data is presented. The method tests cubic specimens and can provide constitutive data along three mutually perpendicular axes. Issues of removing the effects of boundary conditions in the proposed device are discussed. Two devices were constructed and used to obtain triaxial stress versus strain data on...

Triaxial testing system for pressure core analysis using image processing technique

NASA Astrophysics Data System (ADS)

Yoneda, J.; Masui, A.; Tenma, N.; Nagao, J.

2013-11-01

In this study, a newly developed innovative triaxial testing system to investigate strength, deformation behavior, and/or permeability of gas hydrate bearing-sediments in deep sea is described. Transport of the pressure core from the storage chamber to the interior of the sealing sleeve of a triaxial cell without depressurization was achieved. An image processing technique was used to capture the motion and local deformation of a specimen in a transparent acrylic triaxial pressure cell and digital photographs were obtained at each strain level during the compression test. The material strength was successfully measured and the failure mode was evaluated under high confining and pore water pressures.

Global dynamics and diffusion in triaxial galactic models

NASA Astrophysics Data System (ADS)

Papaphilippou, Y.

We apply the Frequency Map Analysis method to the 3--dimensional logarithmic galactic potential in order to clarify the dynamical behaviour of triaxial power--law galactic models. All the fine dynamical details are displayed in the complete frequency map, a direct representation of the system's Arnol'd web. The influence of resonant lines and the extent of the chaotic zones are directly associated with the physical space of the system. Some new results related with the diffusion of galactic orbits are also discussed. This approach reveals many unknown dynamical features of triaxial galactic potentials and provides strong indications that chaos should be an innate characteristic of triaxial configurations.

Galactic Warps in Triaxial Halos

NASA Astrophysics Data System (ADS)

Jeon, Myoungwon; Kim, Sungsoo S.; Ann, Hong Bae

2009-05-01

We study the behavior of galactic disks in triaxial halos both numerically and analytically to see if warps can be excited and sustained in triaxial potentials. We consider the following two scenarios: (1) galactic disks that are initially tilted relative to the equatorial plane of the halo (for a pedagogical purpose), and (2) tilted infall of dark matter relative to the equatorial plane of the disk and the halo. With numerical simulations of 100,000 disk particles in a fixed halo potential, we find that in triaxial halos, warps can be excited and sustained just as in spherical or axisymmetric halos but they show some oscillatory behavior and even can be transformed to a polar-ring system if the halo has a prolate-like triaxiality. The nonaxisymmetric component of the halo causes the disk to nutate, and the differential nutation between the inner and outer parts of the disk generally makes the magnitude of the warp slightly diminish and fluctuate. We also find that warps are relatively weaker in oblate and oblate-like triaxial halos, and since these halos are the halo configurations of disk galaxies inferred by cosmological simulations, our results are consistent with the fact that most of the observed warps are quite weak. We derive approximate formulae for the torques exerted on the disk by the triaxial halo and the dark matter torus, and with these formulae we successfully describe the behavior of the disks in our simulations. The techniques used in deriving these formulae could be applied for realistic halos with more complex structures.

A triaxial accelerometer monkey algorithm for optimal sensor placement in structural health monitoring

NASA Astrophysics Data System (ADS)

Jia, Jingqing; Feng, Shuo; Liu, Wei

2015-06-01

Optimal sensor placement (OSP) technique is a vital part of the field of structural health monitoring (SHM). Triaxial accelerometers have been widely used in the SHM of large-scale structures in recent years. Triaxial accelerometers must be placed in such a way that all of the important dynamic information is obtained. At the same time, the sensor configuration must be optimal, so that the test resources are conserved. The recommended practice is to select proper degrees of freedom (DOF) based upon several criteria and the triaxial accelerometers are placed at the nodes corresponding to these DOFs. This results in non-optimal placement of many accelerometers. A ‘triaxial accelerometer monkey algorithm’ (TAMA) is presented in this paper to solve OSP problems of triaxial accelerometers. The EFI3 measurement theory is modified and involved in the objective function to make it more adaptable in the OSP technique of triaxial accelerometers. A method of calculating the threshold value based on probability theory is proposed to improve the healthy rate of monkeys in a troop generation process. Meanwhile, the processes of harmony ladder climb and scanning watch jump are proposed and given in detail. Finally, Xinghai NO.1 Bridge in Dalian is implemented to demonstrate the effectiveness of TAMA. The final results obtained by TAMA are compared with those of the original monkey algorithm and EFI3 measurement, which show that TAMA can improve computational efficiency and get a better sensor configuration.

Strength and deformation behaviors of veined marble specimens after vacuum heat treatment under conventional triaxial compression

NASA Astrophysics Data System (ADS)

Su, Haijian; Jing, Hongwen; Yin, Qian; Yu, Liyuan; Wang, Yingchao; Wu, Xingjie

2017-10-01

The mechanical behaviors of rocks affected by high temperature and stress are generally believed to be significant for the stability of certain projects involving rocks, such as nuclear waste storage and geothermal resource exploitation. In this paper, veined marble specimens were treated to high temperature treatment and then used in conventional triaxial compression tests to investigate the effect of temperature, confining pressure, and vein angle on strength and deformation behaviors. The results show that the strength and deformation parameters of the veined marble specimens changed with the temperature, presenting a critical temperature of 600 °C. The triaxial compression strength of a horizontal vein (β = 90°) is obviously larger than that of a vertical vein (β = 0°). The triaxial compression strength, elasticity modulus, and secant modulus have an approximately linear relation to the confining pressure. Finally, Mohr-Coulomb and Hoek-Brown criteria were respectively used to analyze the effect of confining pressure on triaxial compression strength.

A Novel True Triaxial Apparatus to Study the Geomechanical and Fluid Flow Aspects of Energy Exploitations in Geological Formations

NASA Astrophysics Data System (ADS)

Li, Minghui; Yin, Guangzhi; Xu, Jiang; Li, Wenpu; Song, Zhenlong; Jiang, Changbao

2016-12-01

Fluid-solid coupling investigations of the geological storage of CO2, efficient unconventional oil and natural gas exploitations are mostly conducted under conventional triaxial stress conditions ( σ 2 = σ 3), ignoring the effects of σ 2 on the geomechanical properties and permeability of rocks (shale, coal and sandstone). A novel multi-functional true triaxial geophysical (TTG) apparatus was designed, fabricated, calibrated and tested to simulate true triaxial stress ( σ 1 > σ 2 > σ 3) conditions and to reveal geomechanical properties and permeability evolutions of rocks. The apparatus was developed with the capacity to carry out geomechanical and fluid flow experiments at high three-dimensional loading forces and injection pressures under true triaxial stress conditions. The control and measurement of the fluid flow with effective sealing of rock specimen corners were achieved using a specially designed internally sealed fluid flow system. To validate that the apparatus works properly and to recognize the effects of each principal stress on rock deformation and permeability, stress-strain and permeability experiments and a hydraulic fracturing simulation experiment on shale specimens were conducted under true triaxial stress conditions using the TTG apparatus. Results show that the apparatus has advantages in recognizing the effects of σ 2 on the geomechanical properties and permeability of rocks. Results also demonstrate the effectiveness and reliability of the novel TTG apparatus. The apparatus provides a new method of studying the geomechanical properties and permeability evolutions of rocks under true triaxial stress conditions, promoting further investigations of the geological storage of CO2, efficient unconventional oil and gas exploitations.

Experimental Investigation on Deformation Failure Characteristics of Crystalline Marble Under Triaxial Cyclic Loading

NASA Astrophysics Data System (ADS)

Yang, Sheng-Qi; Tian, Wen-Ling; Ranjith, P. G.

2017-11-01

The deformation failure characteristics of marble subjected to triaxial cyclic loading are significant when evaluating the stability and safety of deep excavation damage zones. To date, however, there have been notably few triaxial experimental studies on marble under triaxial cyclic loading. Therefore, in this research, a series of triaxial cyclic tests was conducted to analyze the mechanical damage characteristics of a marble. The post-peak deformation of the marble changed gradually from strain softening to strain hardening as the confining pressure increased from 0 to 10 MPa. Under uniaxial compression, marble specimens showed brittle failure characteristics with a number axial splitting tensile cracks; in the range of σ 3 = 2.5-7.5 MPa, the marble specimens assumed single shear fracture characteristics with larger fracture angles of about 65°. However, at σ 3 = 10 MPa, the marble specimens showed no obvious shear fracture surfaces. The triaxial cyclic experimental results indicate that in the range of the tested confining pressures, the triaxial strengths of the marble specimens under cyclic loading were approximately equal to those under monotonic loading. With the increase in cycle number, the elastic strains of the marble specimens all increased at first and later decreased, achieving maximum values, but the plastic strains of the marble specimens increased nonlinearly. To evaluate quantitatively the damage extent of the marble under triaxial cyclic loading, a damage variable is defined according to the irreversible deformation for each cycle. The evolutions of the elastic modulus for the marble were characterized by four stages: material strengthening, material degradation, material failure and structure slippage. Based on the experimental results of the marble specimens under complex cyclic loading, the cohesion of the marble decreased linearly, but the internal friction angles did not depend on the damage extent. To describe the peak strength characteristics of the marble specimens under complex cyclic loadings with various deformation positions, a revised strength criterion for damaged rocks is offered.

A flexible surface-coil-type resonator using triaxial cable

NASA Astrophysics Data System (ADS)

Hirata, Hiroshi; Ono, Mitsuhiro

1997-09-01

This note describes a newly developed flexible surface-coil-type resonator (FSCR) used for electron paramagnetic resonance (EPR) measurements. A conventional FSCR has used a balanced transmission line made by coaxial lines. The new resonator uses triaxial cable in order to avoid anisotropy of flexure of the transmission line. Experimental results show that the EPR signal measured with the triaxial FSCR is 35% stronger than that measured with the conventional FSCR.

Three-Dimensional Numerical Simulation on Triaxial Failure Mechanical Behavior of Rock-Like Specimen Containing Two Unparallel Fissures

NASA Astrophysics Data System (ADS)

Huang, Yan-Hua; Yang, Sheng-Qi; Zhao, Jian

2016-12-01

A three-dimensional particle flow code (PFC3D) was used for a systematic numerical simulation of the strength failure and cracking behavior of rock-like material specimens containing two unparallel fissures under conventional triaxial compression. The micro-parameters of the parallel bond model were first calibrated using the laboratory results of intact specimens and then validated from the experimental results of pre-fissured specimens under triaxial compression. Numerically simulated stress-strain curves, strength and deformation parameters and macro-failure modes of pre-fissured specimens were all in good agreement with the experimental results. The relationship between stress and the micro-crack numbers was summarized. Crack initiation, propagation and coalescence process of pre-fissured specimens were analyzed in detail. Finally, horizontal and vertical cross sections of numerical specimens were derived from PFC3D. A detailed analysis to reveal the internal damage behavior of rock under triaxial compression was carried out. The experimental and simulated results are expected to improve the understanding of the strength failure and cracking behavior of fractured rock under triaxial compression.

Using tidal streams to investigate the rotation of the Milky Way's dark matter halo

NASA Astrophysics Data System (ADS)

Valluri, Monica; Snyder, Sarah Jean; Price-Whelan, Adrian M.

2017-06-01

The dark matter halos surrounding Milky Way-like galaxies that are formed in cosmological simulations are triaxial. These simulated triaxial halos are expected to be slowly rotating with log-normal distribution of pattern speeds centered on ~0.148h km/s/kpc (Bailin & Steinmetz 2004, ApJ., 616, 27). Stellar streams arising from a satellite experiencing tidal disruption inside such a slowly rotating triaxial halo are expected to be subject to additional forces (e.g. Coriolis forces) that affect the structure of the tidal streams. Using the Python Galaxy dynamics package Gala (Price-Whelan, http://gala.adrian.pw) we have generated simulations of tidal streams in a range of triaxial potentials to explore how the structure of Milky Way's tidal streams, especially the structure of stream bifurcations and the stream orbital plane, are altered by a slow figure rotation of the triaxial dark matter halo. We investigate what can be inferred about halo rotation from current and future data including upcoming data from Gaia. This work is supported by NASA-ATP award NNX15AK79G to the University of Michigan.

Dynamical Evolution and Spin-Orbit Resonances of Potentially Habitable Exoplanets. The Case of GJ 667C

DTIC Science & Technology

2014-01-10

observed trend is consistent with a gravitational acceleration exerted by the inner pair of stars (A and B) in this multiple star system. Our planet...the other hand, the observed trend in the RV of the C component can be caused by its orbital acceleration around the AB pair. 3. LONG-TERM EVOLUTION...polar torque acting on a rotating planet is the sum of the gravitational torque, caused by the triaxial permanent shape and the corresponding quadrupole

The triaxiality and Coriolis effects on the fission barrier in isovolumic nuclei with mass number A = 256 based on multidimensional total Routhian surface calculations

NASA Astrophysics Data System (ADS)

Chai, Qing-Zhen; Zhao, Wei-Juan; Wang, Hua-Lei; Liu, Min-Liang; Xu, Fu-Rong

2018-05-01

The triaxiality and Coriolis effects on the first fission barrier in even-even nuclei with A=256 have been studied in terms of the approach of multidimensional total Routhian surface calculations. The present results are compared with available data and other theories, showing a good agreement. Based on the deformation energy or Routhian curves, the first fission barriers are analyzed, focusing on their shapes, heights, and evolution with rotation. It is found that, relative to the effect on the ground-state minimum, the saddle point, at least the first one, can be strongly affected by the triaxial deformation degree of freedom and Coriolis force. The evolution trends of the macroscopic and microscopic (shell and pairing) contributions as well as the triaxial fission barriers are briefly discussed.

Fractal basins of attraction in the restricted four-body problem when the primaries are triaxial rigid bodies

NASA Astrophysics Data System (ADS)

Suraj, Md Sanam; Asique, Md Chand; Prasad, Umakant; Hassan, M. R.; Shalini, Kumari

2017-11-01

The planar equilateral restricted four-body problem, formulated on the basis of Lagrange's triangular solutions is used to determine the existence and locations of libration points and the Newton-Raphson basins of convergence associated with these libration points. We have supposed that all the three primaries situated on the vertices of an equilateral triangle are triaxial rigid bodies. This paper also deals with the effect of these triaxiality parameters on the regions of motion where the test particle is free to move. Further, the regions on the configuration plane filled by the basins of attraction are determined by using the multivariate version of the Newton-Raphson iterative system. The numerical study reveals that the triaxiality of the primaries is one of the most influential parameters in the four-body problem.

Lifetimes of excited states in triaxially deformed 107Tc and 109,111,113Rh

NASA Astrophysics Data System (ADS)

Hagen, T. W.; Görgen, A.; Korten, W.; Grente, L.; Salsac, M.-D.; Farget, F.; Braunroth, T.; Bruyneel, B.; Celikovic, I.; Clément, E.; de France, G.; Delaune, O.; Dewald, A.; Dijon, A.; Hackstein, M.; Jacquot, B.; Litzinger, J.; Ljungvall, J.; Louchart, C.; Michelagnoli, C.; Napoli, D. R.; Recchia, F.; Rother, W.; Sahin, E.; Siem, S.; Sulignano, B.; Theisen, Ch.; Valiente-Dobon, J. J.

2018-03-01

Lifetimes of excited states in 107Tc, 109Rh, 111Rh, and 113Rh were measured at GANIL using the Recoil-Distance Doppler Shift method. The neutron-rich nuclei were produced in fission reactions in inverse kinematics with a 238U beam impinging on a 9Be target. Fission fragments were identified event-by-event in the ray-tracing spectrometer VAMOS++ and correlated with prompt γ rays observed around the target position with the EXOGAM Ge detector array. Several lifetimes were obtained for states in the positive-parity yrast bands in the four nuclei and compared to triaxial particle-rotor calculations. The results clarify the configuration for the strongest positive-parity band in 107Tc and suggest a gradual increase of triaxial deformation with atomic number Z, reaching almost maximum triaxiality for the neutron-rich Rh nuclei.

Effect of multiple-micronutrient supplementation on maternal nutrient status, infant birth weight and gestational age at birth in a low-income, multi-ethnic population.

PubMed

Brough, Louise; Rees, Gail A; Crawford, Michael A; Morton, R Hugh; Dorman, Edgar K

2010-08-01

Poor nutrient intake during pregnancy can adversely affect both infant and maternal health. The aim was to investigate the efficacy of multiple-micronutrient supplementation during pregnancy in a socially deprived population in the developed world. We conducted a randomised, double-blind, placebo-controlled trial of multiple-micronutrient supplementation including 20 mg Fe and 400 microg folic acid, from the first trimester of pregnancy in 402 mothers, in East London, UK. Nutrient status was measured at recruitment, and at 26 and 34 weeks of gestation. Infants were weighed at birth. At recruitment the prevalence of anaemia was 13 %, vitamin D insufficiency 72 %, thiamin deficiency 12 % and folate deficiency 5 %, with no differences between groups. Only 39 % of women completed the study; rates of non-compliance were similar in both groups. Intention-to-treat analysis showed that participants receiving treatment had higher mean Hb at 26 weeks of gestation (110 (sd 10) v.108 (sd 10) g/l; P = 0.041) and 34 weeks of gestation (113 (sd 12) v.109 (sd 10) g/l; P = 0.003) and packed cell volume concentrations at 26 weeks of gestation (0.330 (sd 0.025) v. 0.323 (sd 0.026) l/l; P = 0.011) and 34 weeks of gestation (0.338 (sd 0.029) v. 0.330 (sd 0.028) l/l; P = 0.014) compared with controls. Analysis of compliant women showed supplemented women had higher median concentrations of serum ferritin, erythrocyte folate and 25-hydroxyvitamin D later in gestation than controls. In the compliant subset (n 149), placebo mothers had more small-for-gestational age (SGA) infants (eight SGA v. thirteen; P = 0.042) than treatment mothers. Baseline micronutrient deficiencies were common; the multiple-micronutrient supplement was well-tolerated and improved nutrient status. Multiple-micronutrient supplements from early pregnancy may be beneficial and larger studies are required to assess impact on birth outcomes and infant development.

Evolution of axis ratios from phase space dynamics of triaxial collapse

NASA Astrophysics Data System (ADS)

Nadkarni-Ghosh, Sharvari; Arya, Bhaskar

2018-04-01

We investigate the evolution of axis ratios of triaxial haloes using the phase space description of triaxial collapse. In this formulation, the evolution of the triaxial ellipsoid is described in terms of the dynamics of eigenvalues of three important tensors: the Hessian of the gravitational potential, the tensor of velocity derivatives, and the deformation tensor. The eigenvalues of the deformation tensor are directly related to the parameters that describe triaxiality, namely, the minor-to-major and intermediate-to-major axes ratios (s and q) and the triaxiality parameter T. Using the phase space equations, we evolve the eigenvalues and examine the evolution of the probability distribution function (PDF) of the axes ratios as a function of mass scale and redshift for Gaussian initial conditions. We find that the ellipticity and prolateness increase with decreasing mass scale and decreasing redshift. These trends agree with previous analytic studies but differ from numerical simulations. However, the PDF of the scaled parameter {\\tilde{q}} = (q-s)/(1-s) follows a universal distribution over two decades in mass range and redshifts which is in qualitative agreement with the universality for conditional PDF reported in simulations. We further show using the phase space dynamics that, in fact, {\\tilde{q}} is a phase space invariant and is conserved individually for each halo. These results demonstrate that the phase space analysis is a useful tool that provides a different perspective on the evolution of perturbations and can be applied to more sophisticated models in the future.

Full magnetic gradient tensor from triaxial aeromagnetic gradient measurements: Calculation and application

NASA Astrophysics Data System (ADS)

Luo, Yao; Wu, Mei-Ping; Wang, Ping; Duan, Shu-Ling; Liu, Hao-Jun; Wang, Jin-Long; An, Zhan-Feng

2015-09-01

The full magnetic gradient tensor (MGT) refers to the spatial change rate of the three field components of the geomagnetic field vector along three mutually orthogonal axes. The tensor is of use to geological mapping, resources exploration, magnetic navigation, and others. However, it is very difficult to measure the full magnetic tensor gradient using existing engineering technology. We present a method to use triaxial aeromagnetic gradient measurements for deriving the full MGT. The method uses the triaxial gradient data and makes full use of the variation of the magnetic anomaly modulus in three dimensions to obtain a self-consistent magnetic tensor gradient. Numerical simulations show that the full MGT data obtained with the proposed method are of high precision and satisfy the requirements of data processing. We selected triaxial aeromagnetic gradient data from the Hebei Province for calculating the full MGT. Data processing shows that using triaxial tensor gradient data allows to take advantage of the spatial rate of change of the total field in three dimensions and suppresses part of the independent noise in the aeromagnetic gradient. The calculated tensor components have improved resolution, and the transformed full tensor gradient satisfies the requirement of geological mapping and interpretation.

A multi-scale homogenization model for fine-grained porous viscoplastic polycrystals: II - Applications to FCC and HCP materials

NASA Astrophysics Data System (ADS)

Song, Dawei; Ponte Castañeda, P.

2018-06-01

In Part I of this work (Song and Ponte Castañeda, 2018a), a new homogenization model was developed for the macroscopic behavior of three-scale porous polycrystals consisting of random distributions of large pores in a fine-grained polycrystalline matrix. In this second part, the model is used to investigate both the instantaneous effective behavior and the finite-strain macroscopic response of porous FCC and HCP polycrystals for axisymmetric loading conditions. The stress triaxiality and Lode parameter are found to have significant effects on the evolution of the substructure, which in turn have important implications for the overall hardening/softening behavior of the porous polycrystal. The intrinsic effect of the texture evolution of the polycrystalline matrix is inferred by appropriate comparisons with corresponding results for porous isotropic materials, and found to be significant, especially at low triaxialities. In particular, the predictions of the model identify, for the first time, two disparate regimes for the macroscopic response of porous polycrystals: a porosity-controlled regime at high triaxialities, and a texture-controlled regime at low triaxialities. The transition between these two regimes is found to be quite sharp, taking place between triaxialities of 1 and 2.

True Triaxial Strength and Failure Modes of Cubic Rock Specimens with Unloading the Minor Principal Stress

NASA Astrophysics Data System (ADS)

Li, Xibing; Du, Kun; Li, Diyuan

2015-11-01

True triaxial tests have been carried out on granite, sandstone and cement mortar using cubic specimens with the process of unloading the minor principal stress. The strengths and failure modes of the three rock materials are studied in the processes of unloading σ 3 and loading σ 1 by the newly developed true triaxial test system under different σ 2, aiming to study the mechanical responses of the rock in underground excavation at depth. It shows that the rock strength increases with the raising of the intermediate principal stress σ 2 when σ 3 is unloaded to zero. The true triaxial strength criterion by the power-law relationship can be used to fit the testing data. The "best-fitting" material parameters A and n ( A > 1.4 and n < 1.0) are almost located in the same range as expected by Al-Ajmi and Zimmerman (Int J Rock Mech Min Sci 563 42(3):431-439, 2005). It indicates that the end effect caused by the height-to-width ratio of the cubic specimens will not significantly affect the testing results under true triaxial tests. Both the strength and failure modes of cubic rock specimens under true triaxial unloading condition are affected by the intermediate principal stress. When σ 2 increases to a critical value for the strong and hard rocks (R4, R5 and R6), the rock failure mode may change from shear to slabbing. However, for medium strong and weak rocks (R3 and R2), even with a relatively high intermediate principal stress, they tend to fail in shear after a large amount of plastic deformation. The maximum extension strain criterion Stacey (Int J Rock Mech Min Sci Geomech Abstr 651 18(6):469-474, 1981) can be used to explain the change of failure mode from shear to slabbing for strong and hard rocks under true triaxial unloading test condition.

Ballast degradation characterized through triaxial test : research results.

DOT National Transportation Integrated Search

2016-06-01

Transportation Technology Center, Inc. (TTCI) : has supported the development of a large-scale : triaxial test device (Figure 1) for testing ballast : size aggregate materials at the University of : Illinois at Urbana-Champaign (UIUC). This new : tes...

3D sensor placement strategy using the full-range pheromone ant colony system

NASA Astrophysics Data System (ADS)

Shuo, Feng; Jingqing, Jia

2016-07-01

An optimized sensor placement strategy will be extremely beneficial to ensure the safety and cost reduction considerations of structural health monitoring (SHM) systems. The sensors must be placed such that important dynamic information is obtained and the number of sensors is minimized. The practice is to select individual sensor directions by several 1D sensor methods and the triaxial sensors are placed in these directions for monitoring. However, this may lead to non-optimal placement of many triaxial sensors. In this paper, a new method, called FRPACS, is proposed based on the ant colony system (ACS) to solve the optimal placement of triaxial sensors. The triaxial sensors are placed as single units in an optimal fashion. And then the new method is compared with other algorithms using Dalian North Bridge. The computational precision and iteration efficiency of the FRPACS has been greatly improved compared with the original ACS and EFI method.

Triaxial fiber optic magnetic field sensor for MRI applications

NASA Astrophysics Data System (ADS)

Filograno, Massimo L.; Pisco, Marco; Catalano, Angelo; Forte, Ernesto; Aiello, Marco; Soricelli, Andrea; Davino, Daniele; Visone, Ciro; Cutolo, Antonello; Cusano, Andrea

2016-05-01

In this paper, we report a fiber-optic triaxial magnetic field sensor, based on Fiber Bragg Gratings (FBGs) integrated with giant magnetostrictive material, the Terfenol-D. The realized sensor has been designed and engineered for Magnetic Resonance Imaging (MRI) applications. A full magneto-optical characterization of the triaxial sensing probe has been carried out, providing the complex relationship among the FBGs wavelength shift and the applied magnetostatic field vector. Finally, the developed fiber optic sensors have been arranged in a sensor network composed of 20 triaxial sensors for mapping the magnetic field distribution in a MRI-room at a diagnostic center in Naples (SDN), equipped with Positron emission tomography/magnetic resonance (PET/MR) instrumentation. Experimental results reveal that the proposed sensor network can be efficiently used in MRI centers for performing quality assurance tests, paving the way for novel integrated tools to measure the magnetic dose accumulated day by day by MRI operators.

Structural phase transition of gold under uniaxial, tensile, and triaxial stresses: An ab initio study

NASA Astrophysics Data System (ADS)

Durandurdu, Murat

2007-07-01

The behavior of gold crystal under uniaxial, tensile, and three different triaxial stresses is studied using an ab initio constant pressure technique within a generalized gradient approximation. Gold undergoes a phase transformation from the face-centered-cubic structure (fcc) to a body-centered-tetragonal (bct) structure having the space group of I4/mmm with the application of uniaxial stress, while it transforms to a face-centered-tetragonal (fct) phase within I4/mmm symmetry under uniaxial tensile loading. Further uniaxial compression of the bct phase results in a symmetry change from I4/mmm to P1 at high stresses and ultimately structural failure around 200.0GPa . For the case of triaxial stresses, gold also converts into a bct state. The critical stress for the fcc-to-bct transformation increases as the ratio of the triaxial stress increases. Both fct and bct phases are elastically unstable.

Miniature piezoelectric triaxial accelerometer measures cranial accelerations

NASA Technical Reports Server (NTRS)

Deboo, G. J.; Rogallo, V. L.

1966-01-01

Tiny triaxial accelerometer whose sensing elements are piezoelectric ceramic beams measures human cranial accelerations when a subject is exposed to a centrifuge or other simulators of g environments. This device could be considered for application in dental, medical, and automotive safety research.

Experimental Study on Properties of Methane Diffusion of Coal Block under Triaxial Compressive Stress

PubMed Central

Zhao, Hong-Bao

2014-01-01

Taking the standard size coal block samples defined by ISRM as research objects, both properties of methane diffusion of coal block under triaxial compressive stress and characteristic influences caused by methane pressure were systematically studied with thermo-fluid-solid coupling with triaxial servocontrolled seepage equipment of methane-containing coal. The result shows the methane diffusion property of coal block under triaxial compressive stress was shown in four-stage as follow, first is sharply reduce stage, second is hyperbolic reduce stage, third is close to a fixed value stage, fourth stage is 0. There is a special point making the reduced rate of characteristic curve of methane diffusion speed become sharply small; the influences of shape of methane diffusion speed characteristic curve caused by methane pressure are not obvious, which only is shown in numerical size of methane diffusion speed. Test time was extended required by appear of the special point makes the reduce rate of methane diffusion speed become sharply small. The fitting four-phase relation of methane diffusion of coal block under triaxial compressive stress was obtained, and the idea is proposed that influences of the fitting four-phase relation caused by methane pressure were only shown in value of fitting parameters. PMID:25531000

Validation of a method to measure the vector fidelity of triaxial vector sensors

NASA Astrophysics Data System (ADS)

De Freitas, J. M.

2018-06-01

A method to measure the misalignment angles and vector fidelity of a mutually orthogonal arrangement of triaxial accelerometers has been validated by introducing known misalignments into the measurement procedure. The method is based on the excitation of all three accelerometers in equal measure and the determination of the second order responsivity tensor as a metric. The sensor axis misalignment angles measured using a sensor rotation technique as a reference were 1.49°  ±  0.05°, 0.63°  ±  0.02°, and 0.78°  ±  0.04°. The resolution of the new approach against the reference was 0.03° with an accuracy of 0.2° and maximum deviation of 0.4°. An ellipticity tensor β that characterises the extent to which a triaxial system preserves the input polarisation state purity was introduced. In a careful laboratory arrangement, up to 98% input polarisation state purity was shown to be maintained. It is recommended that documentation on commercial and research grade high-precision triaxial sensor systems should give the responsivity matrix . This technique will improve the range of vector fidelity measurement tools for triaxial accelerometers and other vector sensors such as magnetometers, gyroscopes and acoustic vector sensors.

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

Buchholz, Stuart A.

This memorandum documents laboratory thermomechanical triaxial strength testing of Waste Isolation Pilot Plant (WIPP) clean salt. The limited study completed independent, adjunct laboratory tests in the United States to assist in validating similar testing results being provided by the German facilities. The testing protocol consisted of completing confined triaxial, constant strain rate strength tests of intact WIPP clean salt at temperatures of 25°C and 100°C and at multiple confining pressures. The stratigraphy at WIPP also includes salt that has been labeled “argillaceous.” The much larger test matrix conducted in Germany included both the so-called clean and argillaceous salts. When combined,more » the total database of laboratory results will be used to develop input parameters for models, assess adequacy of existing models, and predict material behavior. These laboratory studies are also consistent with the goals of the international salt repository research program. The goal of this study was to complete a subset of a test matrix on clean salt from the WIPP undertaken by German research groups. The work was performed at RESPEC in Rapid City, South Dakota. A rigorous Quality Assurance protocol was applied, such that corroboration provides the potential of qualifying all of the test data gathered by German research groups.« less

Tidal dissipation in a homogeneous spherical body. II. Three examples: Mercury, Io, and Kepler-10 b

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

Makarov, Valeri V.; Efroimsky, Michael, E-mail: vvm@usno.navy.mil, E-mail: michael.efroimsky@usno.navy.mil

In Efroimsky and Makarov (Paper I), we derived from the first principles a formula for the tidal heating rate in a homogeneous sphere, compared it with the previously used formulae, and noted the differences. Now we present case studies: Mercury, Kepler-10 b, and a triaxial Io. A sharp frequency dependence of k {sub 2}/Q near spin-orbit resonances yields a sharp dependence of k {sub 2}/Q (and, therefore, of tidal heating) upon the spin rate. Thereby physical libration plays a major role in tidal heating of synchronously rotating planets. The magnitude of libration in the spin rate being defined by themore » planet's triaxiality, the latter becomes a factor determining the dissipation rate. Other parameters equal, a strongly triaxial synchronized body generates more heat than a similar body of a more symmetrical shape. After an initially triaxial object melts and loses its triaxiality, dissipation becomes less intensive; the body can solidify, with the tidal bulge becoming a new figure with triaxiality lower than the original. We derive approximate expressions for the dissipation rate in a Maxwell planet with the Maxwell time longer than the inverse tidal frequency. The expressions derived pertain to the 1:1 and 3:2 resonances and a nonresonant case; so they are applicable to most close-in super-Earths detected. In these planets, the heating outside synchronism is weakly dependent on the eccentricity and obliquity, provided both these parameters's values are moderate. According to our calculation, Kepler-10 b could hardly survive the intensive tidal heating without being synchronized, circularized, and reshaped through a complete or partial melt-down.« less

Ectopic expression of Capsicum-specific cell wall protein Capsicum annuum senescence-delaying 1 (CaSD1) delays senescence and induces trichome formation in Nicotiana benthamiana.

PubMed

Seo, Eunyoung; Yeom, Seon-In; Jo, Sunghwan; Jeong, Heejin; Kang, Byoung-Cheorl; Choi, Doil

2012-04-01

Secreted proteins are known to have multiple roles in plant development, metabolism, and stress response. In a previous study to understand the roles of secreted proteins, Capsicum annuum secreted proteins (CaS) were isolated by yeast secretion trap. Among the secreted proteins, we further characterized Capsicum annuum senescence-delaying 1 (CaSD1), a gene encoding a novel secreted protein that is present only in the genus Capsicum. The deduced CaSD1 contains multiple repeats of the amino acid sequence KPPIHNHKPTDYDRS. Interestingly, the number of repeats varied among cultivars and species in the Capsicum genus. CaSD1 is constitutively expressed in roots, and Agrobacterium-mediated transient overexpression of CaSD1 in Nicotiana benthamiana leaves resulted in delayed senescence with a dramatically increased number of trichomes and enlarged epidermal cells. Furthermore, senescence- and cell division-related genes were differentially regulated by CaSD1-overexpressing plants. These observations imply that the pepper-specific cell wall protein CaSD1 plays roles in plant growth and development by regulating cell division and differentiation.

Consideration of regional variations in climatic and soil conditions in the modified triaxial design method.

DOT National Transportation Integrated Search

2008-11-01

The Texas Department of Transportation (TxDOT) uses the modified triaxial design procedure to check : pavement designs from the flexible pavement system program. Since its original development more than : 50 years ago, little modification has been ma...

Quasi-Static Compression and Low-Velocity Impact Behavior of Tri-Axial Bio-Composite Structural Panels Using a Spherical Head

PubMed Central

Li, Jinghao; Hunt, John F; Gong, Shaoqin; Cai, Zhiyong

2017-01-01

This paper presents experimental results of both quasi-static compression and low-velocity impact behavior for tri-axial bio-composite structural panels using a spherical load head. Panels were made having different core and face configurations. The results showed that panels made having either carbon fiber fabric composite faces or a foam-filled core had significantly improved impact and compressive performance over panels without either. Different localized impact responses were observed based on the location of the compression or impact relative to the tri-axial structural core; the core with a smaller structural element had better impact performance. Furthermore, during the early contact phase for both quasi-static compression and low-velocity impact tests, the panels with the same configuration had similar load-displacement responses. The experimental results show basic compression data could be used for the future design and optimization of tri-axial bio-composite structural panels for potential impact applications. PMID:28772542

Full-Field Strain Methods for Investigating Failure Mechanisms in Triaxial Braided Composites

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Binienda, Wieslaw K.; Goldberg, Robert K.; Roberts, Gary D.

2008-01-01

Recent advancements in braiding technology have led to commercially viable manufacturing approaches for making large structures with complex shape out of triaxial braided composite materials. In some cases, the static load capability of structures made using these materials has been higher than expected based on material strength properties measured using standard coupon tests. A more detailed investigation of deformation and failure processes in large-unit-cell-size triaxial braid composites is needed to evaluate the applicability of standard test methods for these materials and to develop alternative testing approaches. This report presents some new techniques that have been developed to investigate local deformation and failure using digital image correlation techniques. The methods were used to measure both local and global strains during standard straight-sided coupon tensile tests on composite materials made with 12- and 24-k yarns and a 0 /+60 /-60 triaxial braid architecture. Local deformation and failure within fiber bundles was observed and correlations were made between these local failures and global composite deformation and strength.

Triangular Libration Points in the CR3BP with Radiation, Triaxiality and Potential from a Belt

NASA Astrophysics Data System (ADS)

Singh, Jagadish; Taura, Joel John

2017-07-01

In this paper the equations of motion of the circular restricted three body problem is modified to include radiation of the bigger primary, triaxiality of the smaller primary; and gravitational potential created by a belt. We have obtained that due to the perturbations, the locations of the triangular libration points and their linear stability are affected. The points move towards the bigger primary due to the resultant effect of the perturbations. Triangular libration points are stable for 0<μ<μc0<μ<μc and unstable for μc≤μ≤12μc≤μ≤12, where μcμc is the critical mass ratio affected by the perturbations. The radiation of the bigger primary and triaxiality of the smaller primary have destabilizing propensities, whereas the potential created by the belt has stabilizing propensity. This model could be applied in the study of the motion of a dust particle near radiating -triaxial binary system surrounded by a belt.

A primitive study of voxel feature generation by multiple stacked denoising autoencoders for detecting cerebral aneurysms on MRA

NASA Astrophysics Data System (ADS)

Nemoto, Mitsutaka; Hayashi, Naoto; Hanaoka, Shouhei; Nomura, Yukihiro; Miki, Soichiro; Yoshikawa, Takeharu; Ohtomo, Kuni

2016-03-01

The purpose of this study is to evaluate the feasibility of a novel feature generation, which is based on multiple deep neural networks (DNNs) with boosting, for computer-assisted detection (CADe). It is hard and time-consuming to optimize the hyperparameters for DNNs such as stacked denoising autoencoder (SdA). The proposed method allows using SdA based features without the burden of the hyperparameter setting. The proposed method was evaluated by an application for detecting cerebral aneurysms on magnetic resonance angiogram (MRA). A baseline CADe process included four components; scaling, candidate area limitation, candidate detection, and candidate classification. Proposed feature generation method was applied to extract the optimal features for candidate classification. Proposed method only required setting range of the hyperparameters for SdA. The optimal feature set was selected from a large quantity of SdA based features by multiple SdAs, each of which was trained using different hyperparameter set. The feature selection was operated through ada-boost ensemble learning method. Training of the baseline CADe process and proposed feature generation were operated with 200 MRA cases, and the evaluation was performed with 100 MRA cases. Proposed method successfully provided SdA based features just setting the range of some hyperparameters for SdA. The CADe process by using both previous voxel features and SdA based features had the best performance with 0.838 of an area under ROC curve and 0.312 of ANODE score. The results showed that proposed method was effective in the application for detecting cerebral aneurysms on MRA.

Superdeformed and Triaxial States in 42Ca

NASA Astrophysics Data System (ADS)

Hadyńska-KlÈ©k, K.; Napiorkowski, P. J.; Zielińska, M.; Srebrny, J.; Maj, A.; Azaiez, F.; Valiente Dobón, J. J.; Kicińska-Habior, M.; Nowacki, F.; Naïdja, H.; Bounthong, B.; Rodríguez, T. R.; de Angelis, G.; Abraham, T.; Anil Kumar, G.; Bazzacco, D.; Bellato, M.; Bortolato, D.; Bednarczyk, P.; Benzoni, G.; Berti, L.; Birkenbach, B.; Bruyneel, B.; Brambilla, S.; Camera, F.; Chavas, J.; Cederwall, B.; Charles, L.; Ciemała, M.; Cocconi, P.; Coleman-Smith, P.; Colombo, A.; Corsi, A.; Crespi, F. C. L.; Cullen, D. M.; Czermak, A.; Désesquelles, P.; Doherty, D. T.; Dulny, B.; Eberth, J.; Farnea, E.; Fornal, B.; Franchoo, S.; Gadea, A.; Giaz, A.; Gottardo, A.; Grave, X.; GrÈ©bosz, J.; Görgen, A.; Gulmini, M.; Habermann, T.; Hess, H.; Isocrate, R.; Iwanicki, J.; Jaworski, G.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Kmiecik, M.; Karpiński, D.; Kisieliński, M.; Kondratyev, N.; Korichi, A.; Komorowska, M.; Kowalczyk, M.; Korten, W.; Krzysiek, M.; Lehaut, G.; Leoni, S.; Ljungvall, J.; Lopez-Martens, A.; Lunardi, S.; Maron, G.; Mazurek, K.; Menegazzo, R.; Mengoni, D.; Merchán, E.; MÈ©czyński, W.; Michelagnoli, C.; Mierzejewski, J.; Million, B.; Myalski, S.; Napoli, D. R.; Nicolini, R.; Niikura, M.; Obertelli, A.; Özmen, S. F.; Palacz, M.; Próchniak, L.; Pullia, A.; Quintana, B.; Rampazzo, G.; Recchia, F.; Redon, N.; Reiter, P.; Rosso, D.; Rusek, K.; Sahin, E.; Salsac, M.-D.; Söderström, P.-A.; Stefan, I.; Stézowski, O.; Styczeń, J.; Theisen, Ch.; Toniolo, N.; Ur, C. A.; Vandone, V.; Wadsworth, R.; Wasilewska, B.; Wiens, A.; Wood, J. L.; Wrzosek-Lipska, K.; ZiÈ©bliński, M.

2016-08-01

Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in 42Ca were determined from E 2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 02+ has been obtained and the role of triaxiality in the A ˜40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.

Triaxiality of neutron-rich 84,86,88Ge from low-energy nuclear spectra

NASA Astrophysics Data System (ADS)

Lettmann, M.; Werner, V.; Pietralla, N.; Doornenbal, P.; Obertelli, A.; Rodríguez, T. R.; Sieja, K.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Chen, S.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Lapoux, V.; Motobayashi, T.; Niikura, M.; Paul, N.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Ando, T.; Arici, T.; Blazhev, A.; Browne, F.; Bruce, A.; Caroll, R. J.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Górska, M.; Gottardo, A.; Jungclaus, A.; Lee, J.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Momiyama, S.; Moschner, K.; Nagamine, S.; Nakatsuka, N.; Nita, C.; Nobs, C. R.; Olivier, L.; Patel, Z.; Podolyák, Zs.; Rudigier, M.; Saito, T.; Shand, C.; Söderström, P.-A.; Stefan, I.; Vaquero, V.; Wimmer, K.; Xu, Z.

2017-07-01

γ -ray transitions between low-spin states of the neutron-rich 84,86,88Ge were measured by means of in-flight γ -ray spectroscopy at 270 MeV/u. Excited 61+,41,2 + , and 21,2 + states of Ge,8684 and 41+ and 21,2 + states of 88Ge were observed. Furthermore, a candidate for a 31+ state of 86Ge was identified. This state plays a key role in the discussion of ground-state triaxiality of 86Ge, along with other features of its low-energy level scheme. A new region of triaxially deformed nuclei is proposed in the Ge isotopic chain.

Triaxial Probe Magnetic Data Analysis

NASA Technical Reports Server (NTRS)

Shultz, Kimberly; Whittlesey, Albert; Narvaez, Pablo

2007-01-01

The Triaxial Magnetic Moment Analysis software uses measured magnetic field test data to compute dipole and quadrupole moment information from a hardware element. It is used to support JPL projects needing magnetic control and an understanding of the spacecraft-generated magnetic fields. Evaluation of the magnetic moment of an object consists of three steps: acquisition, conditioning, and analysis. This version of existing software was extensively rewritten for easier data acquisition, data analysis, and report presentation, including immediate feedback to the test operator during data acquisition. While prior JPL computer codes provided the same data content, this program has a better graphic display including original data overlaid with reconstructed results to show goodness of fit accuracy and better appearance of the report graphic page. Data are acquired using three magnetometers and two rotations of the device under test. A clean acquisition user interface presents required numeric data and graphic summaries, and the analysis module yields the best fit (least squares) for the magnetic dipole and/or quadrupole moment of a device. The acquisition module allows the user to record multiple data sets, selecting the best data to analyze, and is repeated three times for each of the z-axial and y-axial rotations. In this update, the y-axial rotation starting position has been changed to an option, allowing either the x- or z-axis to point towards the magnetometer. The code has been rewritten to use three simultaneous axes of magnetic data (three probes), now using two "rotations" of the device under test rather than the previous three rotations, thus reducing handling activities on the device under test. The present version of the software gathers data in one-degree increments, which permits much better accuracy of the fit ted data than the coarser data acquisition of the prior software. The data-conditioning module provides a clean data set for the analysis module. For multiple measurements at a given degree, the first measurement is used. For omitted measurements, the missing field is estimated by linear interpolation between the two nearest measurements. The analysis module was rewritten for the dual rotation, triaxial probe measurement process and now has better moment estimation accuracy, based on the finer one degree of data acquisition resolution. The magnetic moments thus computed are used as an input to summarize the total spacecraft field.

Validation of uniaxial and triaxial accelerometers for the assessment of physical activity in preschool children

USDA-ARS?s Scientific Manuscript database

Given the unique physical activity patterns of preschoolers, wearable electronic devices for quantitative assessment of physical activity require validation in this population. Study objective was to validate uniaxial and triaxial accelerometers in preschoolers. Room calorimetry was performed over 3...

Development of in-vessel components of the microfission chamber for ITER.

PubMed

Ishikawa, M; Kondoh, T; Ookawa, K; Fujita, K; Yamauchi, M; Hayakawa, A; Nishitani, T; Kusama, Y

2010-10-01

Microfission chambers (MFCs) will measure the total neutron source strength in ITER. The MFCs will be installed behind blanket modules in the vacuum vessel (VV). Triaxial mineral insulated (MI) cables will carry signals from the MFCs. The joint connecting triaxial MI cables in the VV must be considered because the MFCs and the MI cables will be installed separately at different times. Vacuum tight triaxial connector of the MI cable has been designed and a prototype has been constructed. Performance tests indicate that the connector can be applied to the ITER environment. A small bending-radius test of the MI cable indicates no observed damage at a curvature radius of 100 mm.

Triaxial X-Ray Diffraction Method and its Application to Monitor Residual Stress in Surface Layers after High-Feed Milling

NASA Astrophysics Data System (ADS)

Zaušková, Lucia; Czán, Andrej; Šajgalík, Michal; Pobijak, Jozef; Mikloš, Matej

2017-10-01

High-feed milling is a milling method characteristic with shallow depth of cut and high feed rate to maximize the amount of removed metal from a part, generating residual stresses in the surface and subsurface layers of the machined parts. The residual stress has a large influence on the functional properties of the components. The article is focused on the application of triaxial x-ray diffraction method to monitor residual stresses after high feed milling. Significance of triaxial measuring method is the capability of measuring in different angles so it is possible to acquire stress tensor containing normal and shear stress components.

Development of in-vessel components of the microfission chamber for ITER1

PubMed Central

Ishikawa, M.; Kondoh, T.; Ookawa, K.; Fujita, K.; Yamauchi, M.; Hayakawa, A.; Nishitani, T.; Kusama, Y.

2010-01-01

Microfission chambers (MFCs) will measure the total neutron source strength in ITER. The MFCs will be installed behind blanket modules in the vacuum vessel (VV). Triaxial mineral insulated (MI) cables will carry signals from the MFCs. The joint connecting triaxial MI cables in the VV must be considered because the MFCs and the MI cables will be installed separately at different times. Vacuum tight triaxial connector of the MI cable has been designed and a prototype has been constructed. Performance tests indicate that the connector can be applied to the ITER environment. A small bending-radius test of the MI cable indicates no observed damage at a curvature radius of 100 mm. PMID:21033834

Inertial modes in a rotating triaxial ellipsoid

PubMed Central

Vantieghem, S.

2014-01-01

In this work, we present an algorithm that enables computation of inertial modes and their corresponding frequencies in a rotating triaxial ellipsoid. The method consists of projecting the inertial mode equation onto finite-dimensional bases of polynomial vector fields. It is shown that this leads to a well-posed eigenvalue problem, and hence, that eigenmodes are of polynomial form. Furthermore, these results shed new light onto the question whether the eigenmodes form a complete basis, i.e. whether any arbitrary velocity field can be expanded in a sum of inertial modes. Finally, we prove that two intriguing integral properties of inertial modes in rotating spheres and spheroids also extend to triaxial ellipsoids. PMID:25104908

Ectopic Expression of Capsicum-Specific Cell Wall Protein Capsicum annuum Senescence-Delaying 1 (CaSD1) Delays Senescence and Induces Trichome Formation in Nicotiana benthamiana

PubMed Central

Seo, Eunyoung; Yeom, Seon-In; Jo, SungHwan; Jeong, Heejin; Kang, Byoung-Cheorl; Choi, Doil

2012-01-01

Secreted proteins are known to have multiple roles in plant development, metabolism, and stress response. In a previous study to understand the roles of secreted proteins, Capsicum annuum secreted proteins (CaS) were isolated by yeast secretion trap. Among the secreted proteins, we further characterized Capsicum annuum senescence-delaying 1 (CaSD1), a gene encoding a novel secreted protein that is present only in the genus Capsicum. The deduced CaSD1 contains multiple repeats of the amino acid sequence KPPIHNHKPTDYDRS. Interestingly, the number of repeats varied among cultivars and species in the Capsicum genus. CaSD1 is constitutively expressed in roots, and Agrobacterium-mediated transient overexpression of CaSD1 in Nicotiana benthamiana leaves resulted in delayed senescence with a dramatically increased number of trichomes and enlarged epidermal cells. Furthermore, senescence- and cell division-related genes were differentially regulated by CaSD1-overexpressing plants. These observations imply that the pepper-specific cell wall protein CaSD1 plays roles in plant growth and development by regulating cell division and differentiation. PMID:22441673

Method of using triaxial magnetic fields for making particle structures

DOEpatents

Martin, James E.; Anderson, Robert A.; Williamson, Rodney L.

2005-01-18

A method of producing three-dimensional particle structures with enhanced magnetic susceptibility in three dimensions by applying a triaxial energetic field to a magnetic particle suspension and subsequently stabilizing said particle structure. Combinations of direct current and alternating current fields in three dimensions produce particle gel structures, honeycomb structures, and foam-like structures.

Features of the Kaiser effect in coal specimens at different stages of the triaxial axisymmetric deformation

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

Shkuratnik, V.L.; Filimonov, Y.L.; Kuchurin, S.V.

2007-01-15

The experimental data are presented for the features of formation and manifestation of the acoustic-emission and deformation memory effects in specimens of anthracite at different stages of the triaxial cyclic deformation by the Karman scheme in the pre-limiting and post-limiting zones.

Acoustic-emissive memory effect in coal samples under triaxial axial-symmetric compression

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

Shkuratnik, V.L.; Filimonov, Y.L.; Kuchurin, S.V.

2006-05-15

The experimental data are presented for production and manifestation of the Kaiser effect in coal samples subjected to triaxial loading by the Karman scheme in the first cycle and to various loading modes in the second cycle. The Kaiser effect is identified with the help of a deformation memory effect.

DETECTING TRIAXIALITY IN THE GALACTIC DARK MATTER HALO THROUGH STELLAR KINEMATICS. II. DEPENDENCE ON NATURE DARK MATTER AND GRAVITY

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

Rojas-Niño, Armando; Pichardo, Barbara; Valenzuela, Octavio

Recent studies have presented evidence that the Milky Way global potential may be non-spherical. In this case, the assembling process of the Galaxy may have left long-lasting stellar halo kinematic fossils due to the shape of the dark matter halo, potentially originated by orbital resonances. We further investigate such a possibility, now considering potential models further away from ΛCDM halos, like scalar field dark matter halos and Modified Newtonian Dynamics (MOND), and including several other factors that may mimic the emergence and permanence of kinematic groups, such as a spherical and triaxial halo with an embedded disk potential. We find that regardless ofmore » the density profile (DM nature), kinematic groups only appear in the presence of a triaxial halo potential. For the case of a MOND-like gravity theory no kinematic structure is present. We conclude that the detection of these kinematic stellar groups could confirm the predicted triaxiality of dark halos in cosmological galaxy formation scenarios.« less

Insulin pump treatment compared with multiple daily injections for treatment of type 2 diabetes (OpT2mise): a randomised open-label controlled trial.

PubMed

Reznik, Yves; Cohen, Ohad; Aronson, Ronnie; Conget, Ignacio; Runzis, Sarah; Castaneda, Javier; Lee, Scott W

2014-10-04

Many patients with advanced type 2 diabetes do not meet their glycated haemoglobin targets and randomised controlled studies comparing the efficacy of pump treatment and multiple daily injections for lowering glucose in insulin-treated patients have yielded inconclusive results. We aimed to resolve this uncertainty with a randomised controlled trial (OpT2mise). We did this multicentre, controlled trial at 36 hospitals, tertiary care centres, and referal centres in Canada, Europe, Israel, South Africa, and the USA. Patients with type 2 diabetes who had poor glycaemic control despite multiple daily injections with insulin analogues were enrolled into a 2-month dose-optimisation run-in period. After the run-in period, patients with glycated haemoglobin of 8·0-12·0% (64-108 mmol/mol) were randomly assigned (1:1) by a computer-generated randomisation sequence (block size 2 with probability 0·75 and size 4 with probability 0·25) to pump treatment or to continue with multiple daily injections. Neither patients nor investigators were masked to treatment allocation. The primary endpoint was change in mean glycated haemoglobin between baseline and end of the randomised phase for the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01182493. 495 of 590 screened patients entered the run-in phase and 331 were randomised (168 to pump treatment, 163 to multiple daily injections). Mean glycated haemoglobin at baseline was 9% (75 mmol/mol) in both groups. At 6 months, mean glycated haemoglobin had decreased by 1·1% (SD 1·2; 12 mmol/mol, SD 13) in the pump treatment group and 0·4% (SD 1·1; 4 mmol/mol, SD 12) in the multiple daily injection group, resulting in a between-group treatment difference of -0·7% (95% CI -0·9 to -0·4; -8 mmol/mol, 95% CI -10 to -4, p<0·0001). At the end of the study, the mean total daily insulin dose was 97 units (SD 56) with pump treatment versus 122 units (SD 68) for multiple daily injections (p<0·0001), with no significant difference in bodyweight change between the two groups (1·5 kg [SD 3·5] vs 1·1 kg [3·6], p=0·322). Two diabetes-related serious adverse events (hyperglycaemia or ketosis without acidosis) resulting in hospital admission occurred in the pump treatment group compared with one in the multiple daily injection group. No ketoacidosis occurred in either group and one episode of severe hypoglycaemia occurred in the multiple daily injection group. In patients with poorly controlled type 2 diabetes despite using multiple daily injections of insulin, pump treatment can be considered as a safe and valuable treatment option. Medtronic. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities.

PubMed

Chen, Xuanzhen; Peng, Yong; Peng, Shan; Yao, Song; Chen, Chao; Xu, Ping

2017-01-01

This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture.

Microscopic description of triaxiality in Ru isotopes with covariant energy density functional theory

NASA Astrophysics Data System (ADS)

Shi, Z.; Li, Z. P.

2018-03-01

Background: Triaxiality in nuclear low-lying states has attracted great interest for many years. Recently, reduced transition probabilities for levels near the ground state in 110Ru have been measured and provided strong evidence of a triaxial shape of this nucleus. Purpose: The aim of this work is to provide a microscopic study of low-lying states for Ru isotopes with A ≈100 and to examine in detail the role of triaxiality and the evolution of quadrupole shapes with the isospin and spin degrees of freedom. Method: Low-lying excitation spectra and transition probabilities of even-even Ru isotopes are described at the beyond-mean-field level by solving a five-dimensional collective Hamiltonian with parameters determined by constrained self-consistent mean-field calculations based on the relativistic energy density functional PC-PK1. Results: The calculated energy surfaces, low-energy spectra, and intraband and interband transition rates, as well as some characteristic collective observables, such as E (4g.s . +) /E (2g.s . +) ,E (2γ+) /E (4g.s . +) , and B (E 2 ;2g.s . +→0g.s . +) and γ -band staggerings, are in good agreement with the available experimental data. Conclusions: The main features of the experimental low-lying excitation spectra and electric transition rates are well reproduced and, thus, strongly support the onset of triaxiality in the low-lying excited states of Ru isotopes around 110Ru.

Validity of hip-mounted uniaxial accelerometry with heart-rate monitoring vs. triaxial accelerometry in the assessment of free-living energy expenditure in young children: the IDEFICS Validation Study.

PubMed

Ojiambo, Robert; Konstabel, Kenn; Veidebaum, Toomas; Reilly, John; Verbestel, Vera; Huybrechts, Inge; Sioen, Isabelle; Casajús, José A; Moreno, Luis A; Vicente-Rodriguez, German; Bammann, Karin; Tubic, Bojan M; Marild, Staffan; Westerterp, Klaas; Pitsiladis, Yannis P

2012-11-01

One of the aims of Identification and Prevention of Dietary- and Lifestyle-Induced Health Effects in Children and Infants (IDEFICS) validation study is to validate field measures of physical activity (PA) and energy expenditure (EE) in young children. This study compared the validity of uniaxial accelerometry with heart-rate (HR) monitoring vs. triaxial accelerometry against doubly labeled water (DLW) criterion method for assessment of free-living EE in young children. Forty-nine European children (25 female, 24 male) aged 4-10 yr (mean age: 6.9 ± 1.5 yr) were assessed by uniaxial ActiTrainer with HR, uniaxial 3DNX, and triaxial 3DNX accelerometry. Total energy expenditure (TEE) was estimated using DLW over a 1-wk period. The longitudinal axis of both devices and triaxial 3DNX counts per minute (CPM) were significantly (P < 0.05) associated with physical activity level (PAL; r = 0.51 ActiTrainer, r = 0.49 uniaxial-3DNX, and r = 0.42 triaxial Σ3DNX). Eight-six percent of the variance in TEE could be predicted by a model combining body mass (partial r(2) = 71%; P < 0.05), CPM-ActiTrainer (partial r(2) = 11%; P < 0.05), and difference between HR at moderate and sedentary activities (ModHR - SedHR) (partial r(2) = 4%; P < 0.05). The SE of TEE estimate for ActiTrainer and 3DNX models ranged from 0.44 to 0.74 MJ/days or ∼7-11% of the average TEE. The SE of activity-induced energy expenditure (AEE) model estimates ranged from 0.38 to 0.57 MJ/day or 24-26% of the average AEE. It is concluded that the comparative validity of hip-mounted uniaxial and triaxial accelerometers for assessing PA and EE is similar.

New true-triaxial rock strength criteria considering intrinsic material characteristics

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Li, Cheng; Quan, Xiaowei; Wang, Yanning; Yu, Liyuan; Jiang, Binsong

2018-02-01

A reasonable strength criterion should reflect the hydrostatic pressure effect, minimum principal stress effect, and intermediate principal stress effect. The former two effects can be described by the meridian curves, and the last one mainly depends on the Lode angle dependence function. Among three conventional strength criteria, i.e. Mohr-Coulomb (MC), Hoek-Brown (HB), and Exponent (EP) criteria, the difference between generalized compression and extension strength of EP criterion experience a firstly increase then decrease process, and tends to be zero when hydrostatic pressure is big enough. This is in accordance with intrinsic rock strength characterization. Moreover, the critical hydrostatic pressure I_c corresponding to the maximum difference of between generalized compression and extension strength can be easily adjusted by minimum principal stress influence parameter K. So, the exponent function is a more reasonable meridian curves, which well reflects the hydrostatic pressure effect and is employed to describe the generalized compression and extension strength. Meanwhile, three Lode angle dependence functions of L_{{MN}}, L_{{WW}}, and L_{{YMH}}, which unconditionally satisfy the convexity and differential requirements, are employed to represent the intermediate principal stress effect. Realizing the actual strength surface should be located between the generalized compression and extension surface, new true-triaxial criteria are proposed by combining the two states of EP criterion by Lode angle dependence function with a same lode angle. The proposed new true-triaxial criteria have the same strength parameters as EP criterion. Finally, 14 groups of triaxial test data are employed to validate the proposed criteria. The results show that the three new true-triaxial exponent criteria, especially the Exponent Willam-Warnke criterion (EPWW) criterion, give much lower misfits, which illustrates that the EP criterion and L_{{WW}} have more reasonable meridian and deviatoric function form, respectively. The proposed new true-triaxial strength criteria can provide theoretical foundation for stability analysis and optimization of support design of rock engineering.

A validated approach for modeling collapse of steel structures

NASA Astrophysics Data System (ADS)

Saykin, Vitaliy Victorovich

A civil engineering structure is faced with many hazardous conditions such as blasts, earthquakes, hurricanes, tornadoes, floods, and fires during its lifetime. Even though structures are designed for credible events that can happen during a lifetime of the structure, extreme events do happen and cause catastrophic failures. Understanding the causes and effects of structural collapse is now at the core of critical areas of national need. One factor that makes studying structural collapse difficult is the lack of full-scale structural collapse experimental test results against which researchers could validate their proposed collapse modeling approaches. The goal of this work is the creation of an element deletion strategy based on fracture models for use in validated prediction of collapse of steel structures. The current work reviews the state-of-the-art of finite element deletion strategies for use in collapse modeling of structures. It is shown that current approaches to element deletion in collapse modeling do not take into account stress triaxiality in vulnerable areas of the structure, which is important for proper fracture and element deletion modeling. The report then reviews triaxiality and its role in fracture prediction. It is shown that fracture in ductile materials is a function of triaxiality. It is also shown that, depending on the triaxiality range, different fracture mechanisms are active and should be accounted for. An approach using semi-empirical fracture models as a function of triaxiality are employed. The models to determine fracture initiation, softening and subsequent finite element deletion are outlined. This procedure allows for stress-displacement softening at an integration point of a finite element in order to subsequently remove the element. This approach avoids abrupt changes in the stress that would create dynamic instabilities, thus making the results more reliable and accurate. The calibration and validation of these models are shown. The calibration is performed using a particle swarm optimization algorithm to establish accurate parameters when calibrated to circumferentially notched tensile coupons. It is shown that consistent, accurate predictions are attained using the chosen models. The variation of triaxiality in steel material during plastic hardening and softening is reported. The range of triaxiality in steel structures undergoing collapse is investigated in detail and the accuracy of the chosen finite element deletion approaches is discussed. This is done through validation of different structural components and structural frames undergoing severe fracture and collapse.

Triaxial Swirl Injector Element for Liquid-Fueled Engines

NASA Technical Reports Server (NTRS)

Muss, Jeff

2010-01-01

A triaxial injector is a single bi-propellant injection element located at the center of the injector body. The injector element consists of three nested, hydraulic swirl injectors. A small portion of the total fuel is injected through the central hydraulic injector, all of the oxidizer is injected through the middle concentric hydraulic swirl injector, and the balance of the fuel is injected through an outer concentric injection system. The configuration has been shown to provide good flame stabilization and the desired fuel-rich wall boundary condition. The injector design is well suited for preburner applications. Preburner injectors operate at extreme oxygen-to-fuel mass ratios, either very rich or very lean. The goal of a preburner is to create a uniform drive gas for the turbomachinery, while carefully controlling the temperature so as not to stress or damage turbine blades. The triaxial injector concept permits the lean propellant to be sandwiched between two layers of the rich propellant, while the hydraulic atomization characteristics of the swirl injectors promote interpropellant mixing and, ultimately, good combustion efficiency. This innovation is suited to a wide range of liquid oxidizer and liquid fuels, including hydrogen, methane, and kerosene. Prototype testing with the triaxial swirl injector demonstrated excellent injector and combustion chamber thermal compatibility and good combustion performance, both at levels far superior to a pintle injector. Initial testing with the prototype injector demonstrated over 96-percent combustion efficiency. The design showed excellent high -frequency combustion stability characteristics with oxygen and kerosene propellants. Unlike the more conventional pintle injector, there is not a large bluff body that must be cooled. The absence of a protruding center body enhances the thermal durability of the triaxial swirl injector. The hydraulic atomization characteristics of the innovation allow the design to be rapidly scaled from small in-space applications [500-5,000 lbf (2.2 22.2 kN)] to large thrust engine applications [80,000 lbf (356 kN) and beyond]. The triaxial injector is also less sensitive to eccentricities, manufacturing tolerances, and gap width of many traditional coaxial and pintle injector designs. The triaxial-injector injection orifice configuration provides for high injection stiffness. The low parts count and relatively large injector design features are amenable to low-cost production.

Interpretation of deep directional resistivity measurements acquired in high-angle and horizontal wells using 3-D inversion

NASA Astrophysics Data System (ADS)

Puzyrev, Vladimir; Torres-Verdín, Carlos; Calo, Victor

2018-05-01

The interpretation of resistivity measurements acquired in high-angle and horizontal wells is a critical technical problem in formation evaluation. We develop an efficient parallel 3-D inversion method to estimate the spatial distribution of electrical resistivity in the neighbourhood of a well from deep directional electromagnetic induction measurements. The methodology places no restriction on the spatial distribution of the electrical resistivity around arbitrary well trajectories. The fast forward modelling of triaxial induction measurements performed with multiple transmitter-receiver configurations employs a parallel direct solver. The inversion uses a pre-conditioned gradient-based method whose accuracy is improved using the Wolfe conditions to estimate optimal step lengths at each iteration. The large transmitter-receiver offsets, used in the latest generation of commercial directional resistivity tools, improve the depth of investigation to over 30 m from the wellbore. Several challenging synthetic examples confirm the feasibility of the full 3-D inversion-based interpretations for these distances, hence enabling the integration of resistivity measurements with seismic amplitude data to improve the forecast of the petrophysical and fluid properties. Employing parallel direct solvers for the triaxial induction problems allows for large reductions in computational effort, thereby opening the possibility to invert multiposition 3-D data in practical CPU times.

The prediction of speed and incline in outdoor running in humans using accelerometry.

PubMed

Herren, R; Sparti, A; Aminian, K; Schutz, Y

1999-07-01

To explore whether triaxial accelerometric measurements can be utilized to accurately assess speed and incline of running in free-living conditions. Body accelerations during running were recorded at the lower back and at the heel by a portable data logger in 20 human subjects, 10 men, and 10 women. After parameterizing body accelerations, two neural networks were designed to recognize each running pattern and calculate speed and incline. Each subject ran 18 times on outdoor roads at various speeds and inclines; 12 runs were used to calibrate the neural networks whereas the 6 other runs were used to validate the model. A small difference between the estimated and the actual values was observed: the square root of the mean square error (RMSE) was 0.12 m x s(-1) for speed and 0.014 radiant (rad) (or 1.4% in absolute value) for incline. Multiple regression analysis allowed accurate prediction of speed (RMSE = 0.14 m x s(-1)) but not of incline (RMSE = 0.026 rad or 2.6% slope). Triaxial accelerometric measurements allows an accurate estimation of speed of running and incline of terrain (the latter with more uncertainty). This will permit the validation of the energetic results generated on the treadmill as applied to more physiological unconstrained running conditions.

Energy and Power Requirements of the Global Thermosphere During the Magnetic Storm of November 10, 2004

DTIC Science & Technology

2009-06-17

Electric and magnetic-field perturbations were measured by ion drift meters (IDM) and triaxial fluxgate magnetometers on DMSP F13. F15, and F16...we also regard DMSP as providing lower-bound estimates of the true *pc. The triaxial fluxgate SSM sensors are either mounted on the spacecraft

The Use of Sphere Indentation Experiments to Characterize Ceramic Damage Models

DTIC Science & Technology

2011-09-01

state having two equal eigenvalues. For TXC, the axial stress (single eigenvalue) is more compressive than the lateral stresses (dual eigenvalues). For...parameters. These dynamic experiments supplement traditional characterization experiments such as tension, triaxial compression , Brazilian, and...These dynamic experiments supplement traditional characterization experiments such as tension, triaxial compression , Brazilian, and plate impact, which

Effective field theory for triaxially deformed nuclei

NASA Astrophysics Data System (ADS)

Chen, Q. B.; Kaiser, N.; Meißner, Ulf-G.; Meng, J.

2017-10-01

Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation.

DETECTING TRIAXIALITY IN THE GALACTIC DARK MATTER HALO THROUGH STELLAR KINEMATICS

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

Rojas-Nino, Armando; Valenzuela, Octavio; Pichardo, Barbara

Assuming the dark matter halo of the Milky Way to be a non-spherical potential (i.e., triaxial, prolate, oblate), we show how the assembling process of the Milky Way halo may have left long-lasting stellar halo kinematic fossils due to the shape of the dark matter halo. In contrast with tidal streams, which are associated with recent satellite accretion events, these stellar kinematic groups will typically show inhomogeneous chemical and stellar population properties. However, they may be dominated by a single accretion event for certain mass assembling histories. If the detection of these peculiar kinematic stellar groups were confirmed, they wouldmore » be the smoking gun for the predicted triaxiality of dark halos in cosmological galaxy formation scenarios.« less

An Experimental Study in Determining Energy Expenditure from Treadmill Walking using Hip-Worn Inertial Sensors

PubMed Central

Vathsangam, Harshvardhan; Emken, Adar; Schroeder, E. Todd; Spruijt-Metz, Donna; Sukhatme, Gaurav S.

2011-01-01

This paper describes an experimental study in estimating energy expenditure from treadmill walking using a single hip-mounted triaxial inertial sensor comprised of a triaxial accelerometer and a triaxial gyroscope. Typical physical activity characterization using accelerometer generated counts suffers from two drawbacks - imprecison (due to proprietary counts) and incompleteness (due to incomplete movement description). We address these problems in the context of steady state walking by directly estimating energy expenditure with data from a hip-mounted inertial sensor. We represent the cyclic nature of walking with a Fourier transform of sensor streams and show how one can map this representation to energy expenditure (as measured by V O2 consumption, mL/min) using three regression techniques - Least Squares Regression (LSR), Bayesian Linear Regression (BLR) and Gaussian Process Regression (GPR). We perform a comparative analysis of the accuracy of sensor streams in predicting energy expenditure (measured by RMS prediction accuracy). Triaxial information is more accurate than uniaxial information. LSR based approaches are prone to outlier sensitivity and overfitting. Gyroscopic information showed equivalent if not better prediction accuracy as compared to accelerometers. Combining accelerometer and gyroscopic information provided better accuracy than using either sensor alone. We also analyze the best algorithmic approach among linear and nonlinear methods as measured by RMS prediction accuracy and run time. Nonlinear regression methods showed better prediction accuracy but required an order of magnitude of run time. This paper emphasizes the role of probabilistic techniques in conjunction with joint modeling of triaxial accelerations and rotational rates to improve energy expenditure prediction for steady-state treadmill walking. PMID:21690001

Flow and fracture behavior of aluminum alloy 6082-T6 at different tensile strain rates and triaxialities

PubMed Central

Chen, Xuanzhen; Peng, Shan; Yao, Song; Chen, Chao; Xu, Ping

2017-01-01

This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture. PMID:28759617

Passive detection of vehicle loading

NASA Astrophysics Data System (ADS)

McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

2012-01-01

The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

Wood-based Tri-Axial Sandwich Composite Materials: Design, Fabrication, Testing, Modeling and Application

Treesearch

Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

2014-01-01

As the demand for sustainable materials increases, there are unique challenges and opportunities to develop light-weight green composites materials for a wide range of applications. Thus wood-based composite materials from renewable forests may provide options for some niche applications while helping to protect our environment. In this paper, the wood-based tri-axial...

Estimating Energy Expenditure with the RT3 Triaxial Accelerometer

ERIC Educational Resources Information Center

Maddison, Ralph; Jiang, Yannan; Vander Hoorn, Stephen; Mhurchu, Cliona Ni; Lawes, Carlene M. M.; Rodgers, Anthony; Rush, Elaine

2009-01-01

The RT3 is a relatively new triaxial accelerometer that has replaced the TriTrac. The aim of this study was to validate the RT3 against doubly labeled water (DLW) in a free-living, mixed weight sample of adults. Total energy expenditure (TEE) was measured over a 15-day period using DLW. Activity-related energy expenditure (AEE) was estimated by…

Mechanical Properties of Triaxial Braided Carbon/Epoxy Composites

NASA Technical Reports Server (NTRS)

Bowman, C. L.; Roberts, G. D.; Braley, M. S.; Xie, M.; Booker, M. J.

2003-01-01

In an on-going effort to increase the safety and efficiency of turbine engines, the National Aeronautics and Space Administration is exploring lightweight alternatives to the metal containment structures that currently encase commercial jet engines. Epoxy reinforced with braided carbon fibers is a candidate structural material which may be suitable for an engine case. This paper reports flat-coupon mechanical-property experiments performed to compliment previously reported subcomponent impact testing and analytical simulation of containment structures. Triaxial-braid T700/5208 epoxy and triaxial-braid T700/M36 toughened epoxy composites were evaluated. Also, two triaxial-braid architectures (0 +/- 60 deg., 0 +/- 45 deg.) with the M36 resin were evaluated through tension, compression, and shear testing. Tensile behavior was compared between standard straight-sided specimens (ASTM D3039) and bowtie specimens. Both double-notch shear (ASTM D3846) and Iosepescu (ASTM D5379) tests were performed as well. The M36/0 +/- 45 deg. configuration yield the best response when measurements were made parallel to the axial tows. Conversely, the M36/0 +/- 60 deg. configuration was best when measurements were made perpendicular to the axial tows. The results were used to identify critical properties and to augment the analysis of impact experiments.

Tri-axial tactile sensing element

NASA Astrophysics Data System (ADS)

Castellanos-Ramos, Julián.; Navas-González, Rafael; Vidal-Verdú, F.

2013-05-01

A 13 x 13 square millimetre tri-axial taxel is presented which is suitable for some medical applications, for instance in assistive robotics that involves contact with humans or in prosthetics. Finite Element Analysis is carried out to determine what structure is the best to obtain a uniform distribution of pressure on the sensing areas underneath the structure. This structure has been fabricated in plastic with a 3D printer and a commercial tactile sensor has been used to implement the sensing areas. A three axis linear motorized translation stage with a tri-axial precision force sensor is used to find the parameters of the linear regression model and characterize the proposed taxel. The results are analysed to see to what extent the goal has been reached in this specific implementation.

The origin of lattice instability in bcc tungsten under triaxial loading

NASA Astrophysics Data System (ADS)

Černý, Miroslav; Řehák, Petr; Pokluda, Jaroslav

2017-11-01

Stability of ideal bcc tungsten crystal under triaxial tensile loading was explored from first principles using an analysis of both elastic and dynamic stability. The triaxial stress state was considered as a superposition of axial and biaxial transverse stresses. The region of attainable stresses which was delimited using the computed tensile stress maxima was marginally reduced by occurrence of soft phonons in the crystal lattice. While, under purely hydrostatic tension, the crystal was predicted stable up to 48 GPa, greater magnitude of a differential stress reduced the value of a mean (hydrostatic) stress associated with first phonon instabilities to about 35 GPa. This value is rather close to that recently determined in experiment. Computed phonon spectra were successfully verified with the help of atomistic models of microscopic lattice deformation.

Triaxial Measurement Method for Analysis of Residual Stress after High Feed Milling by X-Ray Diffraction

NASA Astrophysics Data System (ADS)

Čuma, Matúš; Török, Jozef; Telišková, Monika

2016-12-01

Surface integrity is a broad term which includes various quality factors affecting the functional properties of parts. Residual stress is one of these factors. Machining generates residual stresses in the surface and subsurface layers of the structural elements. X-ray diffractometry is a non-destructive method applicable for the measurement of residual stresses in surface and subsurface layers of components. The article is focused on the non-destructive progressive method of triaxial measurement of residual stress after machining the surface of sample by high feed milling technology. Significance of triaxial measuring is the capability of measuring in different angles so it is possible to acquire stress tensor containing normal and shear stress components acting in the spot of measuring, using a Cartesian coordinate system.

Ground Test of the Urine Processing Assembly for Accelerations and Transfer Functions

NASA Technical Reports Server (NTRS)

Houston, Janice; Almond, Deborah F. (Technical Monitor)

2001-01-01

This viewgraph presentation gives an overview of the ground test of the urine processing assembly for accelerations and transfer functions. Details are given on the test setup, test data, data analysis, analytical results, and microgravity assessment. The conclusions of the tests include the following: (1) the single input/multiple output method is useful if the data is acquired by tri-axial accelerometers and inputs can be considered uncorrelated; (2) tying coherence with the matrix yields higher confidence in results; (3) the WRS#2 rack ORUs need to be isolated; (4) and future work includes a plan for characterizing performance of isolation materials.

Application of a single needle type for all image-guided biopsies: results of 100 consecutive core biopsies in various organs using a novel tri-axial, end-cut needle

PubMed Central

Diederich, S; Padge, B; Vossas, U; Hake, R; Eidt, S

2006-01-01

Purpose: To assess feasibility, results and complications in image-guided biopsies using a single needle design in various organs. Materials and methods: 100 consecutive percutaneous biopsies were performed in 54 females and 46 males aged 24–87 years (mean age/standard deviation: 64.5 +/− 12 years) using a full-core end-cut tri-axial full-automatic biopsy needle (18 gauge BioPince ™, InterV-MDTech, Gainesville, Florida) under CT (n=45) or ultrasound (n=55) guidance. In 63 biopsies a coaxial technique was used. Results: Biopsies were obtained of liver (n=32), lymph nodes (n=17), thyroid (n=11), lung (n=9), adrenal (n=9), pelvis (n=6), chest wall/pleura (n=6), mediastinum (n=4), lytic bone lesions (n=2), retroperitoneum (n=1), muscle (n=1), pancreas (n=1), peritoneum (n=1). Between 1 and 6 (mean/SD 2.83 +/− 0.92) needle passes were performed. In 77 cases a malignant (40 metastases, 37 primary tumours) and in 23 a benign lesion was diagnosed. Of the 23 benign lesions a specific diagnosis was possible in 22. In one case necrosis and haemorrhage was diagnosed. In this patient surgery and autopsy both revealed a mediastinal haematoma of unknown origin. Eight minor complications (mild pain/local haematoma requiring no therapy) and three major complications (three pneumothoraces in nine lung biopsies requiring two aspirations and one drainage) were observed. There was no mortality. Conclusion: Percutaneous image-guided biopsy using the described full-core end-cut needle resulted in a specific diagnosis in 99/100 consecutive biopsies in various organs with a low complication rate. We use this needle type for all CT- or US-guided biopsies in all organs except for solid bone. PMID:16766268

Method for measuring tri-axial lumbar motion angles using wearable sheet stretch sensors

PubMed Central

Nakamoto, Hiroyuki; Yamaji, Tokiya; Ootaka, Hideo; Bessho, Yusuke; Nakamura, Ryo; Ono, Rei

2017-01-01

Background Body movements, such as trunk flexion and rotation, are risk factors for low back pain in occupational settings, especially in healthcare workers. Wearable motion capture systems are potentially useful to monitor lower back movement in healthcare workers to help avoid the risk factors. In this study, we propose a novel system using sheet stretch sensors and investigate the system validity for estimating lower back movement. Methods Six volunteers (female:male = 1:1, mean age: 24.8 ± 4.0 years, height 166.7 ± 5.6 cm, weight 56.3 ± 7.6 kg) participated in test protocols that involved executing seven types of movements. The movements were three uniaxial trunk movements (i.e., trunk flexion-extension, trunk side-bending, and trunk rotation) and four multiaxial trunk movements (i.e., flexion + rotation, flexion + side-bending, side-bending + rotation, and moving around the cranial–caudal axis). Each trial lasted for approximately 30 s. Four stretch sensors were attached to each participant’s lower back. The lumbar motion angles were estimated using simple linear regression analysis based on the stretch sensor outputs and compared with those obtained by the optical motion capture system. Results The estimated lumbar motion angles showed a good correlation with the actual angles, with correlation values of r = 0.68 (SD = 0.35), r = 0.60 (SD = 0.19), and r = 0.72 (SD = 0.18) for the flexion-extension, side bending, and rotation movements, respectively (all P < 0.05). The estimation errors in all three directions were less than 3°. Conclusion The stretch sensors mounted on the back provided reasonable estimates of the lumbar motion angles. The novel motion capture system provided three directional angles without capture space limits. The wearable system possessed great potential to monitor the lower back movement in healthcare workers and helping prevent low back pain. PMID:29020053

Fatigue behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP)

Treesearch

Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

2015-01-01

The static and fatigue bending behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP) has been investigated by four-point bending tests. Fatigue panels and weakened panels (wESCP) with an initial interface defect were manufactured for the fatigue tests. Stress σ vs. number of cycles curves (S-N) were recorded under the different stress...

SD-MSAEs: Promoter recognition in human genome based on deep feature extraction.

PubMed

Xu, Wenxuan; Zhang, Li; Lu, Yaping

2016-06-01

The prediction and recognition of promoter in human genome play an important role in DNA sequence analysis. Entropy, in Shannon sense, of information theory is a multiple utility in bioinformatic details analysis. The relative entropy estimator methods based on statistical divergence (SD) are used to extract meaningful features to distinguish different regions of DNA sequences. In this paper, we choose context feature and use a set of methods of SD to select the most effective n-mers distinguishing promoter regions from other DNA regions in human genome. Extracted from the total possible combinations of n-mers, we can get four sparse distributions based on promoter and non-promoters training samples. The informative n-mers are selected by optimizing the differentiating extents of these distributions. Specially, we combine the advantage of statistical divergence and multiple sparse auto-encoders (MSAEs) in deep learning to extract deep feature for promoter recognition. And then we apply multiple SVMs and a decision model to construct a human promoter recognition method called SD-MSAEs. Framework is flexible that it can integrate new feature extraction or new classification models freely. Experimental results show that our method has high sensitivity and specificity. Copyright © 2016 Elsevier Inc. All rights reserved.

Electromagnetic receiver with capacitive electrodes and triaxial induction coil for tunnel exploration

NASA Astrophysics Data System (ADS)

Kai, Chen; Sheng, Jin; Wang, Shun

2017-09-01

A new type of electromagnetic (EM) receiver has been developed by integrating four capacitive electrodes and a triaxial induction coil with an advanced data logger for tunnel exploration. The new EM receiver can conduct EM observations in tunnels, which is one of the principal goals of surface-tunnel-borehole EM detection for deep ore deposit mapping. The use of capacitive electrodes enables us to record the electrical field (E-field) signals from hard rock surfaces, which are high-resistance terrains. A compact triaxial induction coil integrates three independent induction coils for narrow-tunnel exploration applications. A low-time-drift-error clock source is developed for tunnel applications where GPS signals are unavailable. The three main components of our tunnel EM receiver are: (1) four capacitive electrodes for measuring the E-field signal without digging in hard rock regions; (2) a triaxial induction coil sensor for audio-frequency magnetotelluric and controlled-source audio-frequency magnetotelluric signal measurements; and (3) a data logger that allows us to record five-component MT signals with low noise levels, low time-drift-error for the clock source, and high dynamic range. The proposed tunnel EM receiver was successfully deployed in a mine that exhibited with typical noise characteristics. [Figure not available: see fulltext. Caption: The new EM receiver can conduct EM observations in tunnels, which is one of the principal goals of the surface-tunnel-borehole EM (STBEM) detection for deep ore deposit mapping. The use of a capacitive electrode enables us to record the electrical field (E-field) signals from hard rock surfaces. A compact triaxial induction coil integrated three induction coils, for narrow-tunnel applications.

Failure Characteristics of Granite Influenced by Sample Height-to-Width Ratios and Intermediate Principal Stress Under True-Triaxial Unloading Conditions

NASA Astrophysics Data System (ADS)

Li, Xibing; Feng, Fan; Li, Diyuan; Du, Kun; Ranjith, P. G.; Rostami, Jamal

2018-05-01

The failure modes and peak unloading strength of a typical hard rock, Miluo granite, with particular attention to the sample height-to-width ratio (between 2 and 0.5), and the intermediate principal stress was investigated using a true-triaxial test system. The experimental results indicate that both sample height-to-width ratios and intermediate principal stress have an impact on the failure modes, peak strength and severity of rockburst in hard rock under true-triaxial unloading conditions. For longer rectangular specimens, the transition of failure mode from shear to slabbing requires higher intermediate principal stress. With the decrease in sample height-to-width ratios, slabbing failure is more likely to occur under the condition of lower intermediate principal stress. For same intermediate principal stress, the peak unloading strength monotonically increases with the decrease in sample height-to-width. However, the peak unloading strength as functions of intermediate principal stress for different types of rock samples (with sample height-to-width ratio of 2, 1 and 0.5) all present the pattern of initial increase, followed by a subsequent decrease. The curves fitted to octahedral shear stress as a function of mean effective stress also validate the applicability of the Mogi-Coulomb failure criterion for all considered rock sizes under true-triaxial unloading conditions, and the corresponding cohesion C and internal friction angle φ are calculated. The severity of strainburst of granite depends on the sample height-to-width ratios and intermediate principal stress. Therefore, different supporting strategies are recommended in deep tunneling projects and mining activities. Moreover, the comparison of test results of different σ 2/ σ 3 also reveals the little influence of minimum principal stress on failure characteristics of granite during the true-triaxial unloading process.

Investigation of the interface characteristics of Y2O3/GaAs under biaxial strain, triaxial strain, and non-strain conditions

NASA Astrophysics Data System (ADS)

Shi, Li-Bin; Liu, Xu-Yang; Dong, Hai-Kuan

2016-09-01

We investigate the interface behaviors of Y2O3/GaAs under biaxial strain, triaxial strain, and non-strain conditions. This study is performed by first principles calculations based on density functional theory (DFT). First of all, the biaxial strain is realized by changing the lattice constants in ab plane. Averaged electrostatic potential (AEP) is aligned by establishing Y2O3 and GaAs (110) surfaces. The band offsets of Y2O3/GaAs interface under biaxial strain are investigated by generalized gradient approximation and Heyd-Scuseria-Ernzerhof (HSE) functionals. The interface under biaxial strain is suitable for the design of metal oxide semiconductor (MOS) devices because the valence band offsets (VBO) and conduction band offsets (CBO) are larger than 1 eV. Second, the triaxial strain is applied to Y2O3/GaAs interface by synchronously changing the lattice constants in a, b, and c axis. The band gaps of Y2O3 and GaAs under triaxial strain are investigated by HSE functional. We compare the VBO and CBO under triaxial strain with those under biaxial strain. Third, in the absence of lattice strain, the formation energies, charge state switching levels, and migration barriers of native defects in Y2O3 are assessed. We investigate how they will affect the MOS device performance. It is found that VO+2 and Oi-2 play a very dangerous role in MOS devices. Finally, a direct tunneling leakage current model is established. The model is used to analyze current and voltage characteristics of the metal/Y2O3/GaAs.

Electromagnetic transitions in multiple chiral doublet bands

NASA Astrophysics Data System (ADS)

Jia, Hui; Qi, Bin; Wang, Shou-Yu; Wang, Shuo; Liu, Chen

2016-12-01

Multiple chiral doublet bands (MχD) in the 80, 130 and 190 mass regions are studied by the model of γ = 90° triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting a suitable basis, the calculated wave functions are explicitly exhibited to be symmetric under the operator Â, which is defined as rotation by 90° about the 3-axis with the exchange of valance proton and neutron. We found that both M1 and E2 transitions are allowed between levels with different values of A, while they are forbidden between levels with same values of A. Such a selection rule holds true for MχD in different mass regions. Supported by National Natural Science Foundation of China (11675094, 11622540, 11545011, 11405096, 11461141001, U1432119), Shandong Natural Science Foundation (ZR2014AQ012), and Young Scholars Program of Shandong University, Weihai (2015WHWLJH01)

Multi-Quasiparticle Gamma-Band Structure in Neutron-Deficient Ce and Nd Isotopes

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

Sheikh, Javid; Bhat, G. H.; Palit, R.

2009-01-01

The newly developed multi-quasiparticle triaxial projected shell-model approach is employed to study the high-spin band structures in neutron-deficient even-even Ce and Nd isotopes. It is observed that gamma bands are built on each intrinsic configuration of the triaxial mean-field deformation. Due to the fact that a triaxial configuration is a superposition of several K states, the projection from these states results in several low-lying bands originating from the same intrinsic configuration. This generalizes the well-known concept of the surface gamma oscillation in deformed nuclei based on the ground state to gamma bands built on multi-quasiparticle configurations. This new feature providesmore » an alternative explanation on the observation of two I=10 aligning states in ^{134}Ce and both exhibiting a neutron character.« less

Gravitational wave content and stability of uniformly, rotating, triaxial neutron stars in general relativity.

PubMed

Tsokaros, Antonios; Ruiz, Milton; Paschalidis, Vasileios; Shapiro, Stuart L; Baiotti, Luca; Uryū, Kōji

2017-06-15

Targets for ground-based gravitational wave interferometers include continuous, quasiperiodic sources of gravitational radiation, such as isolated, spinning neutron stars. In this work, we perform evolution simulations of uniformly rotating, triaxially deformed stars, the compressible analogs in general relativity of incompressible, Newtonian Jacobi ellipsoids. We investigate their stability and gravitational wave emission. We employ five models, both normal and supramassive, and track their evolution with different grid setups and resolutions, as well as with two different evolution codes. We find that all models are dynamically stable and produce a strain that is approximately one-tenth the average value of a merging binary system. We track their secular evolution and find that all our stars evolve toward axisymmetry, maintaining their uniform rotation, rotational kinetic energy, and angular momentum profiles while losing their triaxiality.

True-Triaxial Experimental Study of the Evolutionary Features of the Acoustic Emissions and Sounds of Rockburst Processes

NASA Astrophysics Data System (ADS)

Su, Guoshao; Shi, Yanjiong; Feng, Xiating; Jiang, Jianqing; Zhang, Jie; Jiang, Quan

2018-02-01

Rockbursts are markedly characterized by the ejection of rock fragments from host rocks at certain speeds. The rockburst process is always accompanied by acoustic signals that include acoustic emissions (AE) and sounds. A deep insight into the evolutionary features of AE and sound signals is important to improve the accuracy of rockburst prediction. To investigate the evolutionary features of AE and sound signals, rockburst tests on granite rock specimens under true-triaxial loading conditions were performed using an improved rockburst testing system, and the AE and sounds during rockburst development were recorded and analyzed. The results show that the evolutionary features of the AE and sound signals were obvious and similar. On the eve of a rockburst, a `quiescent period' could be observed in both the evolutionary process of the AE hits and the sound waveform. Furthermore, the time-dependent fractal dimensions of the AE hits and sound amplitude both showed a tendency to continuously decrease on the eve of the rockbursts. In addition, on the eve of the rockbursts, the main frequency of the AE and sound signals both showed decreasing trends, and the frequency spectrum distributions were both characterized by low amplitudes, wide frequency bands and multiple peak shapes. Thus, the evolutionary features of sound signals on the eve of rockbursts, as well as that of AE signals, can be used as beneficial information for rockburst prediction.

Experimental Study of Slabbing and Rockburst Induced by True-Triaxial Unloading and Local Dynamic Disturbance

NASA Astrophysics Data System (ADS)

Du, Kun; Tao, Ming; Li, Xi-bing; Zhou, Jian

2016-09-01

Slabbing/spalling and rockburst are unconventional types of failure of hard rocks under conditions of unloading and various dynamic loads in environments with high and complex initial stresses. In this study, the failure behaviors of different rock types (granite, red sandstone, and cement mortar) were investigated using a novel testing system coupled to true-triaxial static loads and local dynamic disturbances. An acoustic emission system and a high-speed camera were used to record the real-time fracturing processes. The true-triaxial unloading test results indicate that slabbing occurred in the granite and sandstone, whereas the cement mortar underwent shear failure. Under local dynamically disturbed loading, none of the specimens displayed obvious fracturing at low-amplitude local dynamic loading; however, the degree of rock failure increased as the local dynamic loading amplitude increased. The cement mortar displayed no failure during testing, showing a considerable load-carrying capacity after testing. The sandstone underwent a relatively stable fracturing process, whereas violent rockbursts occurred in the granite specimen. The fracturing process does not appear to depend on the direction of local dynamic loading, and the acoustic emission count rate during rock fragmentation shows that similar crack evolution occurred under the two test scenarios (true-triaxial unloading and local dynamically disturbed loading).

A high performance sensor for triaxial cutting force measurement in turning.

PubMed

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-04-03

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%-0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning.

A High Performance Sensor for Triaxial Cutting Force Measurement in Turning

PubMed Central

Zhao, You; Zhao, Yulong; Liang, Songbo; Zhou, Guanwu

2015-01-01

This paper presents a high performance triaxial cutting force sensor with excellent accuracy, favorable natural frequency and acceptable cross-interference for high speed turning process. Octagonal ring is selected as sensitive element of the designed sensor, which is drawn inspiration from ring theory. A novel structure of two mutual-perpendicular octagonal rings is proposed and three Wheatstone full bridge circuits are specially organized in order to obtain triaxial cutting force components and restrain cross-interference. Firstly, the newly developed sensor is tested in static calibration; test results indicate that the sensor possesses outstanding accuracy in the range of 0.38%–0.83%. Secondly, impacting modal tests are conducted to identify the natural frequencies of the sensor in triaxial directions (i.e., 1147 Hz, 1122 Hz and 2035 Hz), which implies that the devised sensor can be used for cutting force measurement in a high speed lathe when the spindle speed does not exceed 17,205 rev/min in continuous cutting condition. Finally, an application of the sensor in turning process is operated to show its performance for real-time cutting force measurement; the measured cutting forces demonstrate a good accordance with the variation of cutting parameters. Thus, the developed sensor possesses perfect properties and it gains great potential for real-time cutting force measurement in turning. PMID:25855035

Mechanical Properties of Triaxial Braided Carbon/Epoxy Composites

NASA Technical Reports Server (NTRS)

Bowman, C. L.; Roberts, G. D.; Braley, M. S.; Xie, M.; Booker, M. J.

2003-01-01

In an on-going effort to increase the safety and efficiency of turbine engines, the National Aeronautics and Space Administration is exploring lightweight alternatives to the metal containment structures that currently encase commercial jet engines. Epoxy reinforced with braided carbon fibers is a candidate structural material which may be suitable for an engine case. This paper reports flat-coupon mechanical-property experiments performed to compliment previously reported subcomponent impact testing and analytical simulation of containment structures. Triaxial-braid T700/5208 epoxy and triaxial-braid T700h436 toughened epoxy composites were evaluated. Also, two triaxial-braid architectures (0 degrees plus or minus 60 degrees, and 0 degrees plus or minus 45 degrees) with the M36 resin were evaluated through tension, compression, and shear testing. Tensile behavior was compared between standard straight-sided specimens (ASTM D3039) and bow-tie specimens. Both double-notch shear (ASTM D3846) and Iosepescu (ASTM D5379) tests were performed as well. The M36/O degrees plus or minus 45 degrees configuration yield the best response when measurements were made parallel to the axial tows. Conversely, the M36/0 degrees plus or minus 60 degrees configuration was best when measurements were made perpendicular to the axial tows. The results were used to identify critical properties and to augment the analysis of impact experiments.

Triaxial cosmological haloes and the disc of satellites

NASA Astrophysics Data System (ADS)

Bowden, A.; Evans, N. W.; Belokurov, V.

2013-10-01

We construct simple triaxial generalizations of Navarro-Frenk-White haloes. The models have elementary gravitational potentials, together with a density that is cusped like 1/r at small radii and falls off like 1/r3 at large radii. The ellipticity varies with radius in a manner that can be tailored to the user's specification. The closed periodic orbits in the planes perpendicular to the short and long axes of the model are well described by epicyclic theory, and can be used as building blocks for long-lived discs. As an application, we carry out the simulations of thin discs of satellites in triaxial dark halo potentials. This is motivated by the recent claims of an extended, thin disc of satellites around the M31 galaxy with a vertical rms scatter of ˜12 kpc and a radial extent of ˜300 kpc. We show that a thin satellite disc can persist over cosmological times if and only if it lies in the planes perpendicular to the long or short axis of a triaxial halo, or in the equatorial or polar planes of a spheroidal halo. In any other orientation, then the disc thickness doubles on ˜5 Gyr time-scales and so must have been born with an implausibly small vertical scaleheight.

Alternative Penetrometers to Measure the Near Surface Strength of Soft Seafloor Soils

DTIC Science & Technology

2011-09-30

penetrometer (CPT), standard ball penetrometer (BPT), mini-ball penetrometer (mBPT) and a shear vane ( VST ). The CPT and BPT measure electronically a...The VST records the undrained shear strength of the soil at discreet depths. In addition, Shelby tube samples were collected for triaxial and...benchmark strengths from the VST and triaxial/simple shear tests. Thus far, the VST strengths have compared favorably with the results. Results from the

Portable Magnetic Gradiometer for Real-Time Localization and Classification of Unexploded Ordnance

DTIC Science & Technology

2006-09-01

classification (DLC) of Unexploded Ordnance (UXO). The portable gradiometer processes data from triaxial fluxgate magnetometers to develop sets of...low-noise (ង pTrms/√Hz) fluxgate -type Triaxial Magnetometers (TM). Paired sets of TMs comprise magnetic gradient sensor “axes” of the array that...channels of analog B-field data. The digitizers can be locked to the Global Positioning System to provide; a) Precise sensor channel timing, and b

Live Site Demonstrations - Massachusetts Military Reservation

DTIC Science & Technology

2014-09-26

from the ESTCP. It has three mutually orthogonal transmit loops in the Z, Y , and X directions and contains seven triaxial receiver antennas inside...It has three mutually orthogonal transmit loops in the Z, Y , and X directions and contains seven triaxial receiver antennas inside the Z (bottom...met if the modeled X, Y locations of the IVS seed items are within 15 centimeters (cm) of the actual locations, if the depth (Z direction ) is within

Microwave Ablation With a Triaxial Antenna: Results in ex vivo Bovine Liver

PubMed Central

Brace, Christopher L.; Laeseke, Paul F.; van der Weide, Daniel W.; Lee, Fred T.

2007-01-01

We apply a new triaxial antenna for microwave ablation procedures to an ex vivo bovine liver. The antenna consists of a coaxial monopole inserted through a biopsy needle positioned one quarter-wavelength from the antenna base. The insertion needle creates a triaxial structure, which enhances return loss more than 10 dB, maximizing energy transfer to the tissue while minimizing feed cable heating and invasiveness. Numerical electromagnetic and thermal simulations are used to optimize the antenna design and predict heating patterns. Numerical and ex vivo experimental results show that the lesion size depends strongly on ablation time and average input power, but not on peak power. Pulsing algorithms are also explored. We were able to measure a 3.8-cm lesion using 50 W for 7 min, which we believe to be the largest lesion reported thus far using a 17-gauge insertion needle. PMID:18079981

Summary report of mission acceleration measurements for Spacehab-01, STS-57 launched 21 June 1993

NASA Technical Reports Server (NTRS)

Finley, Brian; Grodsinsky, Carlos; Delombard, Richard

1994-01-01

The maiden voyage of the commercial Spacehab laboratory module onboard the STS-57 mission was integrated with several accelerometer packages, one of which was the Space Acceleration Measurement System (SAMS). The June 21st 1993, launch was the seventh successful mission for the Office of Life and Microgravity Sciences and Application's (OLMSA) SAMS unit. This flight was also complemented by a second accelerometer system. The Three Dimensional Microgravity Accelerometer (3-DMA), a Code C funded acceleration measurement system, offering an on-orbit residual calibration as a reference for the unit's four triaxial accelerometers. The SAMS accelerometer unit utilized three remote triaxial sensor heads mounted on the forward Spacehab module bulkhead and on one centrally located experiment locker door. These triaxial heads had filter cut-offs set to 5, 50, and 1000 Hz. The mission also included other experiment specific accelerometer packages in various locations.

Synthesis of triaxial LiFePO4 nanowire with a VGCF core column and a carbon shell through the electrospinning method.

PubMed

Hosono, Eiji; Wang, Yonggang; Kida, Noriyuki; Enomoto, Masaya; Kojima, Norimichi; Okubo, Masashi; Matsuda, Hirofumi; Saito, Yoshiyasu; Kudo, Tetsuichi; Honma, Itaru; Zhou, Haoshen

2010-01-01

A triaxial LiFePO4 nanowire with a multi wall carbon nanotube (VGCF:Vapor-grown carbon fiber) core column and an outer shell of amorphous carbon was successfully synthesized through the electrospinning method. The carbon nanotube core oriented in the direction of the wire played an important role in the conduction of electrons during the charge-discharge process, whereas the outer amorphous carbon shell suppressed the oxidation of Fe2+. An electrode with uniformly dispersed carbon and active materials was easily fabricated via a single process by heating after the electrospinning method is applied. Mossbauer spectroscopy for the nanowire showed a broadening of the line width, indicating a disordered coordination environment of the Fe ion near the surface. The electrospinning method was proven to be suitable for the fabrication of a triaxial nanostructure.

Strain Rate and Stress Triaxiality Effects on Ductile Damage of Additive Manufactured TI-6AL-4V

NASA Astrophysics Data System (ADS)

Iannitti, Gianluca; Bonora, Nicola; Gentile, Domenico; Ruggiero, Andrew; Testa, Gabriel; Gubbioni, Simone

2017-06-01

In this work, the effects of strain rate and stress triaxiality on ductile damage of additive manufactured Ti-6Al-4V, also considering the build direction, were investigated. Raw material was manufactured by means of EOSSINT M2 80 machine, based on Direct Metal Laser Sintering technology, and machined to obtain round notched bar and Rod-on-Rod (RoR) specimens. Tensile tests on round notched bar specimens were performed in a wide range of strain rates. The failure strains at different stress triaxiality were used to calibrate the Bonora Damage Model. In order to design the RoR tests, numerical simulations were performed for assessing velocities at which incipient and fully developed damage occur. Tests at selected velocities were carried out and soft-recovered specimens were sectioning and polishing to observe the developed damage. Nucleated voids maps were compared with numerical simulations results.

Burst Testing of Triaxial Braided Composite Tubes

NASA Technical Reports Server (NTRS)

Salem, J. A.; Bail, J. L.; Wilmoth, N. G.; Ghosn, L. J.; Kohlman, L. W.; Roberts, G. D.; Martin, R. E.

2014-01-01

Applications using triaxial braided composites are limited by the materials transverse strength which is determined by the delamination capacity of unconstrained, free-edge tows. However, structural applications such as cylindrical tubes can be designed to minimize free edge effects and thus the strength with and without edge stresses is relevant to the design process. The transverse strength of triaxial braided composites without edge effects was determined by internally pressurizing tubes. In the absence of edge effects, the axial and transverse strength were comparable. In addition, notched specimens, which minimize the effect of unconstrained tow ends, were tested in a variety of geometries. Although the commonly tested notch geometries exhibited similar axial and transverse net section failure strength, significant dependence on notch configuration was observed. In the absence of unconstrained tows, failure ensues as a result of bias tow rotation, splitting, and fracture at cross-over regions.

Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada

USGS Publications Warehouse

Mower, Timothy E.; Higgins, Jerry D.; Yang, In C.; Peters, Charles A.

1994-01-01

Study of the hydrologic system at Yucca Mountain, Nevada, requires the extraction of pore-water samples from welded and nonwelded, unsaturated tuffs. Two compression methods (triaxial compression and one-dimensional compression) were examined to develop a repeatable extraction technique and to investigate the effects of the extraction method on the original pore-fluid composition. A commercially available triaxial cell was modified to collect pore water expelled from tuff cores. The triaxial cell applied a maximum axial stress of 193 MPa and a maximum confining stress of 68 MPa. Results obtained from triaxial compression testing indicated that pore-water samples could be obtained from nonwelded tuff cores that had initial moisture contents as small as 13 percent (by weight of dry soil). Injection of nitrogen gas while the test core was held at the maximum axial stress caused expulsion of additional pore water and reduced the required initial moisture content from 13 to 11 percent. Experimental calculations, together with experience gained from testing moderately welded tuff cores, indicated that the triaxial cell used in this study could not apply adequate axial or confining stress to expel pore water from cores of densely welded tuffs. This concern led to the design, fabrication, and testing of a one-dimensional compression cell. The one-dimensional compression cell used in this study was constructed from hardened 4340-alloy and nickel-alloy steels and could apply a maximum axial stress of 552 MPa. The major components of the device include a corpus ring and sample sleeve to confine the sample, a piston and base platen to apply axial load, and drainage plates to transmit expelled water from the test core out of the cell. One-dimensional compression extracted pore water from nonwelded tuff cores that had initial moisture contents as small as 7.6 percent; pore water was expelled from densely welded tuff cores that had initial moisture contents as small as 7.7 percent. Injection of nitrogen gas at the maximum axial stress did not produce additional pore water from nonwelded tuff cores, but was critical to recovery of pore water from densely welded tuff cores. Gas injection reduced the required initial moisture content in welded tuff cores from 7.7 to 6.5 percent. Based on the mechanical ability of a pore-water extraction method to remove water from welded and nonwelded tuff cores, one-dimensional compression is a more effective extraction method than triaxial compression. However, because the effects that one-dimensional compression has on pore-water chemistry are not completely understood, additional testing will be needed to verify that this method is suitable for pore-water extraction from Yucca Mountain tuffs.

Behavioral and Socio-Emotional Functioning in Children with Selective Mutism: A Comparison with Anxious and Typically Developing Children across Multiple Informants

ERIC Educational Resources Information Center

Carbone, Diana; Schmidt, Louis A.; Cunningham, Charles C.; McHolm, Angela E.; Edison, Shannon; St. Pierre, Jeff; Boyle, Michael H.

2010-01-01

We examined differences among 158 children, 44 with selective mutism (SM; M = 8.2 years, SD = 3.4 years), 65 with mixed anxiety (MA; M = 8.9 years, SD = 3.2 years), and 49 community controls (M = 7.7 years, SD = 2.6 years) on primary caregiver, teacher, and child reports of behavioral and socio-emotional functioning. Children with SM were rated…

Health status and costs of ambulatory patients with multiple sclerosis in Hungary.

PubMed

Péntek, Márta; Gulácsi, László; Rózsa, Csilla; Simó, Magdolna; Iljicsov, Anna; Komoly, Sámuel; Brodszky, Valentin

2012-09-30

Data on disease burden of multiple sclerosis from Eastern-Central Europe are very limited. Our aim was to explore the quality of life, resource utilisation and costs of ambulating patients with multiple sclerosis in Hungary. Cross-sectional questionnaire survey was performed in two outpatient neurology centres in 2009. Clinical history, health care utilisation in the past 12 months were surveyed, the Expanded Disability Status Scale and the EQ-5D questionnaires were applied. Cost calculation was conducted from the societal perspective. Sixty-eight patients (female 70.6%) aged 38.0 (SD 9.1) with disease duration of 7.8 (SD 6.7) years were involved. Fifty-five (80.9%) had relapsing-remitting form and 52 (76.5%) were taking immunomodulatory drug. The average scores were: Expanded Disability Status Scale 1.9 (SD 1.7), EQ-5D 0.67 (SD 0.28). Mean total cost amounted to 10 902 Euros/patient/year (direct medical 67%, direct nonmedical 13%, indirect costs 20%). Drugs, disability pension and informal care were the highest cost items. Costs of mild (Expanded Disability Status Scale 0-3.5) and moderate (Expanded Disability Status Scale 4.0-6.5) disease were 9 218 and 17 634 Euros/patient/year respectively (p<0.01), that is lower than results from Western European countries. Our study provides current inputs for policy making and contributes to understanding variation of cost-of-illness of multiple sclerosis in Europe.

System Wide Joint Position Sensor Fault Tolerance in Robot Systems Using Cartesian Accelerometers

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.; Juang, Jer-Nan

1997-01-01

Joint position sensors are necessary for most robot control systems. A single position sensor failure in a normal robot system can greatly degrade performance. This paper presents a method to obtain position information from Cartesian accelerometers without integration. Depending on the number and location of the accelerometers. the proposed system can tolerate the loss of multiple position sensors. A solution technique suitable for real-time implementation is presented. Simulations were conducted using 5 triaxial accelerometers to recover from the loss of up to 4 joint position sensors on a 7 degree of freedom robot moving in general three dimensional space. The simulations show good estimation performance using non-ideal accelerometer measurements.

Spasmodic Dysphonia in Multiple Sclerosis Treatment With Botulin Toxin A: A Pilot Study.

PubMed

Di Stadio, Arianna; Bernitsas, Evanthia; Restivo, Domenico Antonio; Alfonsi, Enrico; Marchese-Ragona, Rosario

2018-04-09

This study aims to evaluate the effect of botulin toxin A in patients with multiple sclerosis (MS) affected by spasmodic dysphonia (SD) and to show the safety and effectiveness of this treatment in long-term observation. This is a pilot study on three relapsing-remitting MS patients with SD and their response to botulin toxin A. None of the patients reported dysphagia or other adverse events. Significant improvement was observed in terms of both voice quality and laryngostroboscopy results. The treatment effect was durable for 6-8 months. Botulin toxin A is a safe treatment that can be successfully used to treat SD in patients with MS. Larger studies are necessary to confirm our results. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

An unusual surgical indication for cerebral tuberculosis: status dystonicus. Case report.

PubMed

Franzini, Andrea; Franzini, Angelo; Levi, Vincenzo; Cordella, Roberto; Messina, Giuseppe

2018-05-15

Actual indications for surgery in tuberculosis are limited to obtaining a diagnosis, acquiring tissue for culture studies, treating hydrocephalus, aspiring a brain abscess, and reducing intracranial pressure in patients with multiple tuberculomas. Tuberculosis-related movement disorders are usually treated pharmacologically. We report on a child affected by post-tubercular generalized dystonia, who progressed to status dystonicus (SD) and underwent stereotactic bilateral pallidotomy. After surgery, SD resolved, and drugs were rapidly tapered. The successful reversal of SD and the motor improvement observed in our patient demonstrate the safety, feasibility, and clinical efficacy of pallidotomy in post-tuberculous-meningoencephalitis dystonia and SD.

Influence of triaxial braid denier on ribbon-based fiber reinforced dental composites.

PubMed

Karbhari, Vistasp M; Wang, Qiang

2007-08-01

The aim of the study was to compare the mechanical characteristics of two ultrahigh molecular weight polyethylene (UHMWPE) fiber-based triaxial braided reinforcements having different denier braider yarns used in fiber reinforced dental composites to elucidate differences in response and damage under flexural loading. Two commercially available triaxial braided reinforcing systems, differing in denier of the axial and braider yarns, using ultra high molecular weight polyethylene (UHMWPE) were used to reinforce rectangular bars towards the tensile surface which were tested in flexure. Mechanical characteristics including energy absorption were determined and results were compared based on Tukey post-test analysis and Weibull probability. Limited fatigue testing was also conducted for 100, 1000, and 10,000 cycles at a level of 75% of peak load. The effect of the braid denier on damage mechanisms was studied microscopically. The use of the triaxially braided ribbon as fiber reinforcement in the dental composite results in significant enhancement in flexural performance over that of the unreinforced dental composite (179% and 183% increase for the "thin" and "dense" braid reinforced specimens, respectively), with a fairly ductile, non-catastrophic post-peak response. With the exception of strain at peak load, there was very little difference between the performance from the two braid architectures. The intrinsic nature of the triaxial braid also results in very little decrease in flexural strength as a result of fatigue cycling at 75% of peak load. Use of the braids results in peak load levels which are substantially higher than those corresponding to points at which the dentin and unreinforced dental composites would fail. The total energy at peak load level is 56.8 and 60.7 times that at the level that dentin would fail if the reinforcement were not placed for the "thin" and "dense" reinforced braid reinforced composites, respectively. The research shows that in addition to enhancement in flexural performance characteristics, the use of a triaxial braid provides significant damage tolerance and fatigue resistance through its characteristic architecture wherein axial fibers are uncrimped and braider yarns provide shear resistance and enable local arrest of microcracks. Further, it is demonstrated that the decrease in braider yarn denier does not have a detrimental effect, with differences in performance characteristics, being in the main, statistically insignificant. This allows use of thinner reinforcement which provides ease of placement and better bonding without loss in performance.

Modeling of Failure for Analysis of Triaxial Braided Carbon Fiber Composites

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Littell, Justin D.; Binienda, Wieslaw K.

2010-01-01

In the development of advanced aircraft-engine fan cases and containment systems, composite materials are beginning to be used due to their low weight and high strength. The design of these structures must include the capability of withstanding impact loads from a released fan blade. Relatively complex triaxially braided fiber architectures have been found to yield the best performance for the fan cases. To properly work with and design these structures, robust analytical tools are required that can be used in the design process. A new analytical approach models triaxially braided carbon fiber composite materials within the environment of a transient dynamic finite-element code, specifically the commercially available transient dynamic finite-element code LS-DYNA. The geometry of the braided composites is approximated by a series of parallel laminated composites. The composite is modeled by using shell finite elements. The material property data are computed by examining test data from static tests on braided composites, where optical strain measurement techniques are used to examine the local strain variations within the material. These local strain data from the braided composite tests are used along with a judicious application of composite micromechanics- based methods to compute the stiffness properties of an equivalent unidirectional laminated composite required for the shell elements. The local strain data from the braided composite tests are also applied to back out strength and failure properties of the equivalent unidirectional composite. The properties utilized are geared towards the application of a continuum damage mechanics-based composite constitutive model available within LS-DYNA. The developed model can be applied to conduct impact simulations of structures composed of triaxially braided composites. The advantage of this technology is that it facilitates the analysis of the deformation and damage response of a triaxially braided polymer matrix composite within the environment of a transient dynamic finite-element code such as LS-DYNA in a manner which accounts for the local physical mechanisms but is still computationally efficient. This methodology is tightly coupled to experimental tests on the braided composite, which ensures that the material properties have physical significance. Aerospace or automotive companies interested in using triaxially braided composites in their structures, particularly for impact or crash applications, would find the technology useful. By the development of improved design tools, the amount of very expensive impact testing that will need to be performed can be significantly reduced.

Experimental Study of Nonassociated Flow and Instability of Frictional Materials. Attachment No. 1

DTIC Science & Technology

1993-04-01

pressure range of 0.25 to 68.9 MPa. One-dimensional compression tests up to 900 MPa axial stress level were also performed. U Strain localization was studied... range of confining pressures. Vesic and Clough (1968) performed a series of drained, triaxial compression tests on Chattahoochee River sand at confining...realization resulted in many investigators developing cubical triaxial testing apparatus, in which the full range of the effect of the intermediate I principal

Feasibility of Using the Space Shuttle to Conduct Global Geomagnetic Surveys (Phase I - Retrievable Probes)

DTIC Science & Technology

1985-07-01

Datatape Division 4-1 5.0 REFERENCES Acuna, M.H. et. al., The MAGSAT Vector Magnetometer - A Precision Fluxgate Magnetometer for the Measurement of the...charting would consist of a triaxial, mutually orthogonal fluxgate magnetometer and an absolute scalar magnetometer to check the flux- gates drift...While space-ready, triaxial fluxgate magnetometers are not an off-the-shelf item, their design concepts are well understood. Their resolution of less

Tides in a body librating about a spin-orbit resonance: generalisation of the Darwin-Kaula theory

NASA Astrophysics Data System (ADS)

Frouard, Julien; Efroimsky, Michael

2017-09-01

The Darwin-Kaula theory of bodily tides is intended for celestial bodies rotating without libration. We demonstrate that this theory, in its customary form, is inapplicable to a librating body. Specifically, in the presence of libration in longitude, the actual spectrum of Fourier tidal modes differs from the conventional spectrum rendered by the Darwin-Kaula theory for a nonlibrating celestial object. This necessitates derivation of formulae for the tidal torque and the tidal heating rate, that are applicable under libration. We derive the tidal spectrum for longitudinal forced libration with one and two main frequencies, generalisation to more main frequencies being straightforward. (By main frequencies we understand those emerging due to the triaxiality of the librating body.) Separately, we consider a case of free libration at one frequency (once again, generalisation to more frequencies being straightforward). We also calculate the tidal torque. This torque provides correction to the triaxiality-caused physical libration. Our theory is not self-consistent: we assume that the tidal torque is much smaller than the permanent-triaxiality-caused torque, so the additional libration due to tides is much weaker than the main libration due to the permanent triaxiality. Finally, we calculate the tidal dissipation rate in a body experiencing forced libration at the main mode, or free libration at one frequency, or superimposed forced and free librations.

Fully alternating, triaxial electric or magnetic fields offer new routes to fluid vorticity

DOE PAGES

Martin, James E.; Solis, Kyle J.

2014-10-31

Noncontact methods of generating strong fluid vorticity are important to problems involving heat and mass transfer, fluid mixing, active wetting, and droplet transport. Furthermore, because zero or even negative shear viscosities can be induced, vorticity can greatly extend the control range of the smart fluids used in magnetorheological devices. In recent work we have shown that a particular class of ac/ac/dc triaxial fields (so-called symmetry-breaking rational fields) can create strong vorticity in magnetic particle suspensions and have presented a theory of the vorticity that is based on the symmetry of the 2-d Lissajous trajectories of the field and its converse.more » In this paper we demonstrate that there are three countably infinite sets of fully alternating ac/ac/ac triaxial fields whose frequencies form rational triads that have the symmetry required to drive fluid vorticity. The symmetry of the 3-d Lissajous trajectories of the field and its converse can be derived and from this the direction of the vorticity axis can be predicted, as can the dependence of the sign of the vorticity on the phase relations between the three field components. Experimental results are presented that validate the symmetry theory. These discoveries significantly broaden the class of triaxial fields that can be exploited to produce strong noncontact flow.« less

NDPC-SD Data Probes Worksheet

ERIC Educational Resources Information Center

National Dropout Prevention Center for Students with Disabilities, 2011

2011-01-01

This worksheet from the National Dropout Prevention Center for Students with Disabilities (NDPC-SD) is an optional tool to help schools organize multiple years of student and program data for the purpose of identifying school-completion needs that can be addressed through the implementation of research-based interventions. It is designed for use…

Summary Report of Mission Acceleration Measurements for STS-62, Launched 4 March 1994

NASA Technical Reports Server (NTRS)

Rogers, Melissa J. B.; Delombard, Richard

1994-01-01

The second mission of the United States Microgravity Payload on-board the STS-62 mission was supported with three accelerometer instruments: the Orbital Acceleration Research Experiment (OARE) and two units of the Space Acceleration Measurements System (SAMS). The March 4, 1994 launch was the fourth successful mission for OARE and the ninth successful mission for SAMS. The OARE instrument utilizes a sensor for very low frequency measurements below one Hertz. The accelerations in this frequency range are typically referred to as quasisteady accelerations. One of the SAMS units had two remote triaxial sensor heads mounted on the forward MPESS structure between two furnance experiments, MEPHISTO and AADSF. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The other SAMS unit utilized three remote triaxial sensor heads. Two of the sensor heads were mounted on the aft MPESS structure between the two experiments IDGE and ZENO. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The third sensor head was mounted on the thermostat housing inside the IDGE experiment container. This triaxial head had a low-pass filter cut-off frequency at 5 Hz. This report is prepared to furnish interested experiment investigators with a guide to evaluating the acceleration environment during STS-62 and as a means of identifying areas which require further study. To achieve this purpose, various pieces of information are included, such as an overview of the STS-62 mission, a description of the accelerometer system flown on STS-62, some specific analysis of the accelerometer data in relation to the various mission activities, and an overview of the low-gravity environment during the entire mission. An evaluation form is included at the end of the report to solicit users' comments about the usefulness of this series of reports.

Small-Body Extensions for the Satellite Orbit Analysis Program (SOAP)

NASA Technical Reports Server (NTRS)

Carnright, Robert; Stodden, David; Coggi, John

2008-01-01

An extension to the SOAP software allows users to work with tri-axial ellipsoid-based representations of planetary bodies, primarily for working with small, natural satellites, asteroids, and comets. SOAP is a widely used tool for the visualization and analysis of space missions. The small body extension provides the same visualization and analysis constructs for use with small bodies. These constructs allow the user to characterize satellite path and instrument cover information for small bodies in both 3D display and numerical output formats. Tri-axial ellipsoids are geometric shapes the diameters of which are different in each of three principal x, y, and z dimensions. This construct provides a better approximation than using spheres or oblate spheroids (ellipsoids comprising two common equatorial diameters as a distinct polar diameter). However, the tri-axial ellipsoid is considerably more difficult to work with from a modeling perspective. In addition, the SOAP small-body extensions allow the user to actually employ a plate model for highly irregular surfaces. Both tri-axial ellipsoids and plate models can be assigned to coordinate frames, thus allowing for the modeling of arbitrary changes to body orientation. A variety of features have been extended to support tri-axial ellipsoids, including the computation and display of the spacecraft sub-orbital point, ground trace, instrument footprints, and swathes. Displays of 3D instrument volumes can be shown interacting with the ellipsoids. Longitude/latitude grids, contour plots, and texture maps can be displayed on the ellipsoids using a variety of projections. The distance along an arbitrary line of sight can be computed between the spacecraft and the ellipsoid, and the coordinates of that intersection can be plotted as a function of time. The small-body extension supports the same visual and analytical constructs that are supported for spheres and oblate spheroids in SOAP making the implementation of the more complex algorithms largely transparent to the user.

Failure in laboratory fault models in triaxial tests

USGS Publications Warehouse

Savage, J.C.; Lockner, D.A.; Byerlee, J.D.

1996-01-01

A model of a fault in the Earth is a sand-filled saw cut in a granite cylinder subjected to a triaxial test. The saw cut is inclined at an angle a to the cylinder axis, and the sand filling is intended to represent gouge. The triaxial test subjects the granite cylinder to a constant confining pressure and increasing axial stress to maintain a constant rate of shortening of the cylinder. The required axial stress increases at a decreasing rate to a maximum, beyond which a roughly constant axial stress is sufficient to maintain the constant rate of shortening: Such triaxial tests were run for saw cuts inclined at angles ?? of 20??, 25??, 30??, 35??, 40??, 45??, and 50?? to the cylinder axis, and the apparent coefficient of friction ??a (ratio of the shear stress to the normal stress, both stresses resolved onto the saw cut) at failure was determined. Subject to the assumption that the observed failure involves slip on Coulomb shears (orientation unspecified), the orientation of the principal compression axis within the gouge can be calculated as a function of ??a for a given value of the coefficient of internal friction ??i. The rotation of the principal stress axes within the gouge in a triaxial test can then be followed as the shear strain across the gouge layer increases. For ??i ??? 0.8, an appropriate value for highly sheared sand, the observed values ??a imply that the principal-axis of compression within the gouge rotates so as to approach being parallel to the cylinder axis for all saw cut angles (20?? < ?? < 50??). In the limiting state (principal compression axis parallel to cylinder axis) the stress state in the gouge layer would be the same as that in the granite cylinder, and the failure criterion would be independent of the saw cut angle.

Description of plastic deformation of structural materials in triaxial loading

NASA Astrophysics Data System (ADS)

Lagzdins, A.; Zilaucs, A.

2008-03-01

A model of nonassociated plasticity is put forward for initially isotropic materials deforming with residual changes in volume under the action of triaxial normal stresses. The model is based on novel plastic loading and plastic potential functions, which define closed, convex, every where smooth surfaces in the 6D space of symmetric second-rank stress tensors. By way of example, the plastic deformation of a cylindrical concrete specimen wrapped with a CFRP tape and loaded in axial compression is described.

Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met

NASA Technical Reports Server (NTRS)

Adams, D. F.; Hartmann, U. G.; Lazarow, L. L.; Maloy, J. O.; Mohler, G. W.

1976-01-01

The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities.

On-Time 3D Time-Domain EMI and Tensor Magnetic Gradiometry for UXO Detection and Discrimination

DTIC Science & Technology

2008-06-04

three-axis fluxgate magnetometers mounted on a tetrahedral structure as shown in figure 5.1.3.1. TMGS was intended to measure gradients of vector...manufacturer of the fluxgate magnetometers supplied specifications for each of the triaxial sensors (figure 5.3.2.25). Figure 5.3.2.25...Manufacturer’s specifications for the four triaxial fluxgate magnetometers used in the TMGS planar array. As shown previously in figure 5.3.2.4

Triaxiality in the odd-A nuclei 109-117I studied through a microscopic rotationparticle coupling

NASA Astrophysics Data System (ADS)

Modi, Swati

2018-05-01

A systematic study of ground state spectrum with the triaxial deformation γ for odd-A Iodine isotopes 109-117I is carried out with the nonadiabatic quasiparticle approach. The rotation-particle coupling is accomplished microscopically such that the matrix elements of a particle-plus-rotor system are written in terms of the rotor energies. The 5/2+ state is confirmed as ground state for odd-A 111-117I and also coming out as lowest in energy for 109I.

Home-based exercise program and fall-risk reduction in older adults with multiple sclerosis: phase 1 randomized controlled trial.

PubMed

Sosnoff, Jacob J; Finlayson, Marcia; McAuley, Edward; Morrison, Steve; Motl, Robert W

2014-03-01

To determine the feasibility, safety, and efficacy of a home-based exercise intervention targeting fall risk in older adults with multiple sclerosis. A randomized controlled pilot trial. A home-based exercise program. Participants were randomly allocated to either a home-based exercise intervention group (n = 13) or a waiting list control group (n = 14). The exercise group completed exercises targeting lower muscle strength and balance three times a week for 12 weeks. The control group continued normal activity. Fall risk (Physiological Profile Assessment scores), balance (Berg Balance Scale), and walking testing prior to and immediately following the 12-week intervention. Each outcome measure was placed in an analysis of covariance with group as the between-subject factor and baseline values as the covariate. Effect sizes were calculated. Twelve participants from the control group and ten from the exercise group completed the study. There were no related adverse events. Fall risk was found to decrease in the exercise group following the intervention (1.1 SD 1.0 vs. 0.6 SD 0.6) while there was an increase in fall risk in the control group (1.9 SD 1.5 vs. 2.2 SD 1.9). Effect sizes for most outcomes were large (η(2) > 0.15). Home-based exercise was found to be feasible, safe, and effective for reducing physiological fall risk in older adults with multiple sclerosis. Our findings support the implementation of a larger trial to reduce fall risk in persons with multiple sclerosis.

How UV photolysis accelerates the biodegradation and mineralization of sulfadiazine (SD).

PubMed

Pan, Shihui; Yan, Ning; Liu, Xinyue; Wang, Wenbing; Zhang, Yongming; Liu, Rui; Rittmann, Bruce E

2014-11-01

Sulfadiazine (SD), one of broad-spectrum antibiotics, exhibits limited biodegradation in wastewater treatment due to its chemical structure, which requires initial mono-oxygenation reactions to initiate its biodegradation. Intimately coupling UV photolysis with biodegradation, realized with the internal loop photobiodegradation reactor, accelerated SD biodegradation and mineralization by 35 and 71 %, respectively. The main organic products from photolysis were 2-aminopyrimidine (2-AP), p-aminobenzenesulfonic acid (ABS), and aniline (An), and an SD-photolysis pathway could be identified using C, N, and S balances. Adding An or ABS (but not 2-AP) into the SD solution during biodegradation experiments (no UV photolysis) gave SD removal and mineralization rates similar to intimately coupled photolysis and biodegradation. An SD biodegradation pathway, based on a diverse set of the experimental results, explains how the mineralization of ABS and An (but not 2-AP) provided internal electron carriers that accelerated the initial mono-oxygenation reactions of SD biodegradation. Thus, multiple lines of evidence support that the mechanism by which intimately coupled photolysis and biodegradation accelerated SD removal and mineralization was through producing co-substrates whose oxidation produced electron equivalents that stimulated the initial mono-oxygenation reactions for SD biodegradation.

Effect of Particle Shape on Mechanical Behaviors of Rocks: A Numerical Study Using Clumped Particle Model

PubMed Central

Rong, Guan; Liu, Guang; Zhou, Chuang-bing

2013-01-01

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied. PMID:23997677

Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

PubMed

Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

2013-01-01

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

A triaxial supramolecular weave

NASA Astrophysics Data System (ADS)

Lewandowska, Urszula; Zajaczkowski, Wojciech; Corra, Stefano; Tanabe, Junki; Borrmann, Ruediger; Benetti, Edmondo M.; Stappert, Sebastian; Watanabe, Kohei; Ochs, Nellie A. K.; Schaeublin, Robin; Li, Chen; Yashima, Eiji; Pisula, Wojciech; Müllen, Klaus; Wennemers, Helma

2017-11-01

Despite recent advances in the synthesis of increasingly complex topologies at the molecular level, nano- and microscopic weaves have remained difficult to achieve. Only a few diaxial molecular weaves exist—these were achieved by templation with metals. Here, we present an extended triaxial supramolecular weave that consists of self-assembled organic threads. Each thread is formed by the self-assembly of a building block comprising a rigid oligoproline segment with two perylene-monoimide chromophores spaced at 18 Å. Upon π stacking of the chromophores, threads form that feature alternating up- and down-facing voids at regular distances. These voids accommodate incoming building blocks and establish crossing points through CH-π interactions on further assembly of the threads into a triaxial woven superstructure. The resulting micrometre-scale supramolecular weave proved to be more robust than non-woven self-assemblies of the same building block. The uniform hexagonal pores of the interwoven network were able to host iridium nanoparticles, which may be of interest for practical applications.

Two-dimensional mapping of triaxial strain fields in a multiferroic BiFeO3 thin film using scanning x-ray microdiffraction

NASA Astrophysics Data System (ADS)

Bark, Chung W.; Cho, Kyung C.; Koo, Yang M.; Tamura, Nobumichi; Ryu, Sangwoo; Jang, Hyun M.

2007-03-01

The dramatically enhanced polarizations and saturation magnetizations observed in the epitaxially constrained BiFeO3 (BFO) thin films with their pronounced grain-orientation dependence have attracted much attention and are attributed largely to the constrained in-plane strain. Thus, it is highly desirable to directly obtain information on the two-dimensional (2D) distribution of the in-plane strain and its correlation with the grain orientation of each corresponding microregion. Here the authors report a 2D quantitative mapping of the grain orientation and the local triaxial strain field in a 250nm thick multiferroic BFO film using a synchrotron x-ray microdiffraction technique. This direct scanning measurement demonstrates that the deviatoric component of the in-plane strain tensor is between 5×10-3 and 6×10-3 and that the local triaxial strain is fairly well correlated with the grain orientation in that particular region.

Empirical model with independent variable moments of inertia for triaxial nuclei applied to 76Ge and 192Os

NASA Astrophysics Data System (ADS)

Sugawara, M.

2018-05-01

An empirical model with independent variable moments of inertia for triaxial nuclei is devised and applied to 76Ge and 192Os. Three intrinsic moments of inertia, J1, J2, and J3, are varied independently as a particular function of spin I within a revised version of the triaxial rotor model so as to reproduce the energy levels of the ground-state, γ , and (in the case of 192Os) Kπ=4+ bands. The staggering in the γ band is well reproduced in both phase and amplitude. Effective γ values are extracted as a function of spin I from the ratios of the three moments of inertia. The eigenfunctions and the effective γ values are subsequently used to calculate the ratios of B (E 2 ) values associated with these bands. Good agreement between the model calculation and the experimental data is obtained for both 76Ge and 192Os.

Roto-orbital dynamics of a triaxial rigid body around a sphere. Relative equilibria and stability

NASA Astrophysics Data System (ADS)

Crespo, F.; Ferrer, S.

2018-06-01

We study the roto-orbital motion of a triaxial rigid body around a sphere, which is assumed to be much more massive than the triaxial body. The associated dynamics of this system, which consists of a normalized Hamiltonian with respect to the fast angles (partial averaging), is investigated making use of variables referred to the total angular momentum. The first order approximation of this model is integrable. We carry out the analysis of the relative equilibria, which hinges principally in the dihedral angle between the orbital and rotational planes and the ratio among the moments of inertia ρ = (B - A) / (2 C - B - A) . In particular, the dynamics of the body frame, though formally given by the classical Euler equations, experiences changes of stability in the principal directions related to the roto-orbital coupling. When ρ = 1 / 3 , we find a family of relative equilibria connected to the unstable equilibria of the free rigid body.

Investigation of a Macromechanical Approach to Analyzing Triaxially-Braided Polymer Composites

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Blinzler, Brina J.; Binienda, Wieslaw K.

2010-01-01

A macro level finite element-based model has been developed to simulate the mechanical and impact response of triaxially-braided polymer matrix composites. In the analytical model, the triaxial braid architecture is simulated by using four parallel shell elements, each of which is modeled as a laminated composite. The commercial transient dynamic finite element code LS-DYNA is used to conduct the simulations, and a continuum damage mechanics model internal to LS-DYNA is used as the material constitutive model. The material stiffness and strength values required for the constitutive model are determined based on coupon level tests on the braided composite. Simulations of quasi-static coupon tests of a representative braided composite are conducted. Varying the strength values that are input to the material model is found to have a significant influence on the effective material response predicted by the finite element analysis, sometimes in ways that at first glance appear non-intuitive. A parametric study involving the input strength parameters provides guidance on how the analysis model can be improved.

Triaxial constitutive model for plain and reinforced concrete behavior

NASA Astrophysics Data System (ADS)

Kang, Hong Duk

Inelastic failure analysis of concrete structures has been one of the central issues in concrete mechanics. Especially, the effect of confinement has been of great importance to capture the transition from brittle to ductile fracture of concrete under triaxial loading scenarios. Moreover, it has been a difficult task to implement numerically material descriptions which are susceptible to loss of stability and localization. Consequently, it has been a challenge to develop comprehensive material formulations of concrete, which consider the full spectrum of loading histories which the material in a real structure is subjected to. A new triaxial constitutive model of concrete is presented that not only describes the hardening/softening behavior of concrete in tension and low confined compression, but also captures the transition from brittle to ductile failure under high confinement. The concrete model is based on a loading surface that is Csp1-continuous, and that closes smoothly in equitriaxial compression, while the deviatoric trace expands from a triangular to a circular shape with increasing confinement. The plastic potential has a different curvature from the plastic loading function for non-associativity in order to reduce excessive inelastic dilatancy. In the thesis, the results of deformation and localization analyses for various loading histories are presented in the constitutive study. In addition, studies of associativity and non-associativity, and two-invariant versus three-invariant formulations are performed. At the structural level the triaxial concrete model is used to predict the nonlinear response behavior of a reinforced concrete column subject to axial and lateral loadings.

Falls classification using tri-axial accelerometers during the five-times-sit-to-stand test.

PubMed

Doheny, Emer P; Walsh, Cathal; Foran, Timothy; Greene, Barry R; Fan, Chie Wei; Cunningham, Clodagh; Kenny, Rose Anne

2013-09-01

The five-times-sit-to-stand test (FTSS) is an established assessment of lower limb strength, balance dysfunction and falls risk. Clinically, the time taken to complete the task is recorded with longer times indicating increased falls risk. Quantifying the movement using tri-axial accelerometers may provide a more objective and potentially more accurate falls risk estimate. 39 older adults, 19 with a history of falls, performed four repetitions of the FTSS in their homes. A tri-axial accelerometer was attached to the lateral thigh and used to identify each sit-stand-sit phase and sit-stand and stand-sit transitions. A second tri-axial accelerometer, attached to the sternum, captured torso acceleration. The mean and variation of the root-mean-squared amplitude, jerk and spectral edge frequency of the acceleration during each section of the assessment were examined. The test-retest reliability of each feature was examined using intra-class correlation analysis, ICC(2,k). A model was developed to classify participants according to falls status. Only features with ICC>0.7 were considered during feature selection. Sequential forward feature selection within leave-one-out cross-validation resulted in a model including four reliable accelerometer-derived features, providing 74.4% classification accuracy, 80.0% specificity and 68.7% sensitivity. An alternative model using FTSS time alone resulted in significantly reduced classification performance. Results suggest that the described methodology could provide a robust and accurate falls risk assessment. Copyright © 2013 Elsevier B.V. All rights reserved.

Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial.

PubMed

Hermanides, J; Nørgaard, K; Bruttomesso, D; Mathieu, C; Frid, A; Dayan, C M; Diem, P; Fermon, C; Wentholt, I M E; Hoekstra, J B L; DeVries, J H

2011-10-01

To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes. In this investigator-initiated multi-centre trial (the Eurythmics Trial) in eight outpatient centres in Europe, we randomized 83 patients with Type 1 diabetes (40 women) currently treated with multiple daily injections, age 18-65 years and HbA(1c) ≥ 8.2% (≥ 66 mmol/mol) to 26 weeks of treatment with either a sensor-augmented insulin pump (n = 44) (Paradigm(®) REAL-Time) or continued with multiple daily injections (n = 39). Change in HbA(1c) between baseline and 26 weeks, sensor-derived endpoints and patient-reported outcomes were assessed. The trial was completed by 43/44 (98%) patients in the sensor-augmented insulin pump group and 35/39 (90%) patients in the multiple daily injections group. Mean HbA(1c) at baseline and at 26 weeks changed from 8.46% (SD 0.95) (69 mmol/mol) to 7.23% (SD 0.65) (56 mmol/mol) in the sensor-augmented insulin pump group and from 8.59% (SD 0.82) (70 mmol/mol) to 8.46% (SD 1.04) (69 mmol/mol) in the multiple daily injections group. Mean difference in change in HbA(1c) after 26 weeks was -1.21% (95% confidence interval -1.52 to -0.90, P < 0.001) in favour of the sensor-augmented insulin pump group. This was achieved without an increase in percentage of time spent in hypoglycaemia: between-group difference 0.0% (95% confidence interval -1.6 to 1.7, P = 0.96). There were four episodes of severe hypoglycaemia in the sensor-augmented insulin pump group and one episode in the multiple daily injections group (P = 0.21). Problem Areas in Diabetes and Diabetes Treatment Satisfaction Questionnaire scores improved in the sensor-augmented insulin pump group. Sensor augmented pump therapy effectively lowers HbA(1c) in patients with Type 1 diabetes suboptimally controlled with multiple daily injections. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Association of low non-invasive near-infrared spectroscopic measurements during initial trauma resuscitation with future development of multiple organ dysfunction.

PubMed

Nicks, Bret A; Campons, Kevin M; Bozeman, William P

2015-01-01

Near-infrared spectroscopy (NIRS) non-invasively monitors muscle tissue oxygen saturation (StO2). It may provide a continuous noninvasive measurement to identify occult hypoperfusion, guide resuscitation, and predict the development of multiple organ dysfunction (MOD) after severe trauma. We evaluated the correlation between initial StO2 and the development of MOD in multi-trauma patients. Patients presenting to our urban, academic, Level I Trauma Center/Emergency Department and meeting standardized trauma-team activation criteria were enrolled in this prospective trial. NIRS monitoring was initiated immediately on arrival with collection of StO2 at the thenar eminence and continued up to 24 hours for those admitted to the Trauma Intensive Care Unit (TICU). Standardized resuscitation laboratory measures and clinical evaluation tools were collected. The primary outcome was the association between initial StO2 and the development of MOD within the first 24 hours based on a MOD score of 6 or greater. Descriptive statistical analyses were performed; numeric means, multivariate regression and rank sum comparisons were utilized. Clinicians were blinded from the StO2 values. Over a 14 month period, 78 patients were enrolled. Mean age was 40.9 years (SD 18.2), 84.4% were male, 76.9% had a blunt trauma mechanism and mean injury severity score (ISS) was 18.5 (SD 12.9). Of the 78 patients, 26 (33.3%) developed MOD within the first 24 hours. The MOD patients had mean initial StO2 values of 53.3 (SD 10.3), significantly lower than those of non-MOD patients 61.1 (SD 10.0); P=0.002. The mean ISS among MOD patients was 29.9 (SD 11.5), significantly higher than that of non-MODS patients, 12.1 (SD 9.1) (P<0.0001). The mean shock index (SI) among MOD patients was 0.92 (SD 0.28), also significantly higher than that of non-MODS patients, 0.73 (SD 0.19) (P=0.0007). Lactate values were not significantly different between groups. Non-invasive, continuous StO2 near-infrared spectroscopy values during initial trauma resuscitation correlate with the later development of multiple organ dysfunction in this patient population.

Evidence of chiral bands in even-even nuclei

NASA Astrophysics Data System (ADS)

Petrache, C. M.; Lv, B. F.; Astier, A.; Dupont, E.; Wang, Y. K.; Zhang, S. Q.; Zhao, P. W.; Ren, Z. X.; Meng, J.; Greenlees, P. T.; Badran, H.; Cox, D. M.; Grahn, T.; Julin, R.; Juutinen, S.; Konki, J.; Pakarinen, J.; Papadakis, P.; Partanen, J.; Rahkila, P.; Sandzelius, M.; Saren, J.; Scholey, C.; Sorri, J.; Stolze, S.; Uusitalo, J.; Cederwall, B.; Aktas, Ö.; Ertoprak, A.; Liu, H.; Matta, S.; Subramaniam, P.; Guo, S.; Liu, M. L.; Zhou, X. H.; Wang, K. L.; Kuti, I.; Timár, J.; Tucholski, A.; Srebrny, J.; Andreoiu, C.

2018-04-01

Evidence for chiral doublet bands has been observed for the first time in the even-even nucleus 136Nd. One chiral band was firmly established. Four other candidates for chiral bands were also identified, which can contribute to the realization of the multiple pairs of chiral doublet bands (M χ D ) phenomenon. The observed bands are investigated by the constrained and tilted axis cranking covariant density functional theory (TAC-CDFT). Possible configurations have been explored. The experimental energy spectra, angular momenta, and B (M 1 )/B (E 2 ) values for the assigned configurations are globally reproduced by TAC-CDFT. Calculated results support the chiral interpretation of the observed bands, which correspond to shapes with maximum triaxiality induced by different multiquasiparticle configurations in 136Nd.

Chiral geometry in multiple chiral doublet bands

NASA Astrophysics Data System (ADS)

Zhang, Hao; Chen, Qibo

2016-02-01

The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with . The energy spectra, electromagnetic transition probabilities B(M1) and B(E2), angular momenta, and K-distributions are studied. It is demonstrated that the chirality still remains not only in the yrast and yrare bands, but also in the two higher excited bands when γ deviates from 30°. The chiral geometry relies significantly on γ, and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands. Supported by Plan Project of Beijing College Students’ Scientific Research and Entrepreneurial Action, Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), National Fund for Fostering Talents of Basic Science (NFFTBS) (J1103206), Research Fund for Doctoral Program of Higher Education (20110001110087) and China Postdoctoral Science Foundation (2015M580007)

The effect of practical cooling strategies on physiological response and cognitive function during simulated firefighting tasks

PubMed Central

Hemmatjo, Rasoul; Motamedzade, Majid; Aliabadi, Mohsen; Kalatpour, Omid; Farhadian, Maryam

2017-01-01

Background: Firefighters often perform multiple tasks during firefighting operations under unknown and unpredictable conditions in hot and hostile environments. Methods: In this interventional study each firefighters engaged in 4 conditions: namely (1) no cooling device; control (NC), (2) cooling gel (CG), (3) cool vest (CV), and (4) CG+CV. Cooling effects of the employed interventions were evaluated based on heart rate (HR), temporal temperature (TT), reaction time (RT), and the correct response (CR). Results: HR and TT values for use of CG+CV (147.47 bpm [SD 4.8]; 37.88°C [SD 0.20]) and CV bpm (147.53 [SD 4.67]; 37.90°C [SD 0.22]) were significantly lower than the CG (153.67 bpm [SD 4.82]; 38.10°C [SD 0.22]) and NC (154.4 bpm [SD 4.91]; 38.11°C [SD 0.23]) at the end of the activity. RT and CR for use of CG + CV (389.87 ms [SD 6.12]; 143.53 [SD 1.24]) and CV (389.53 ms [SD 6.24]; 143.47 [SD 1.18]) were significantly higher than the CG (385.73 [SD 7.25] ms; 143.07 [SD 0.88]) and NC (385.67 ms [SD 7.19]; 143.00 [SD 0.84]) at the end of the activity. Conclusion: It is concluded that CV was more effective than the CG in attenuating physiological responses and cognitive functions during firefighting operations. Furthermore, combining CV with CG provides no additional benefit. PMID:28326286

A Wearable Inertial Measurement Unit for Long-Term Monitoring in the Dependency Care Area

PubMed Central

Rodríguez-Martín, Daniel; Pérez-López, Carlos; Samà, Albert; Cabestany, Joan; Català, Andreu

2013-01-01

Human movement analysis is a field of wide interest since it enables the assessment of a large variety of variables related to quality of life. Human movement can be accurately evaluated through Inertial Measurement Units (IMU), which are wearable and comfortable devices with long battery life. The IMU's movement signals might be, on the one hand, stored in a digital support, in which an analysis is performed a posteriori. On the other hand, the signal analysis might take place in the same IMU at the same time as the signal acquisition through online classifiers. The new sensor system presented in this paper is designed for both collecting movement signals and analyzing them in real-time. This system is a flexible platform useful for collecting data via a triaxial accelerometer, a gyroscope and a magnetometer, with the possibility to incorporate other information sources in real-time. A μSD card can store all inertial data and a Bluetooth module is able to send information to other external devices and receive data from other sources. The system presented is being used in the real-time detection and analysis of Parkinson's disease symptoms, in gait analysis, and in a fall detection system. PMID:24145917

Association of objectively measured physical activity with brain structure: UK Biobank study.

PubMed

Hamer, Mark; Sharma, Nikhil; Batty, G David

2018-05-18

Physical activity may be beneficial for cognition but mechanisms are unclear. We examined the association between objectively assessed physical activity and brain volume, with a focus on the hippocampus region. We used data from UK Biobank (n=5,272; aged 55.4±7.5 yrs; 45.6% men) collected through 2013-2016. Participants wore the Axivity AX3 wrist-worn triaxial accelerometer for seven days to assess habitual physical activity. Structural magnetic resonance imaging was performed using a standard Siemens Skyra 3T running VD13A SP4 to obtain images of the brain. There was an association between physical activity (per SD increase) and grey matter volume after adjustment for a range of covariates, although this association was only detected in older adults (>60 yrs old). We also observed associations of physical activity with both left (B=0.52, 95% CI, 0.01, 1.03; p=0.046) and right hippocampal volume (B=0.59, 95% CI, 0.08, 1.10; p=0.024) in covariate adjusted models. In summary, physical activity may play a role in the prevention of neurodegenerative diseases. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A wearable inertial measurement unit for long-term monitoring in the dependency care area.

PubMed

Rodríguez-Martín, Daniel; Pérez-López, Carlos; Samà, Albert; Cabestany, Joan; Català, Andreu

2013-10-18

Human movement analysis is a field of wide interest since it enables the assessment of a large variety of variables related to quality of life. Human movement can be accurately evaluated through Inertial Measurement Units (IMU), which are wearable and comfortable devices with long battery life. The IMU's movement signals might be, on the one hand, stored in a digital support, in which an analysis is performed a posteriori. On the other hand, the signal analysis might take place in the same IMU at the same time as the signal acquisition through online classifiers. The new sensor system presented in this paper is designed for both collecting movement signals and analyzing them in real-time. This system is a flexible platform useful for collecting data via a triaxial accelerometer, a gyroscope and a magnetometer, with the possibility to incorporate other information sources in real-time. A µSD card can store all inertial data and a Bluetooth module is able to send information to other external devices and receive data from other sources. The system presented is being used in the real-time detection and analysis of Parkinson's disease symptoms, in gait analysis, and in a fall detection system.

Cognitive and hippocampus biochemical changes following sleep deprivation in the adult male rat.

PubMed

Nabaee, Ebrahim; Kesmati, Mahnaz; Shahriari, Ali; Khajehpour, Lotfollah; Torabi, Mozhgan

2018-05-14

Sleep deprivation (SD) influences physiological processes such as cognitive function. The balance of oxidant and antioxidant markers, neurotrophic factors and magnesium are affected by sleep deprivation but there is no difference between pre and post training sleep deprivation. This study was designed to investigate memory retrieval and biochemical factors such as oxidant and antioxidant enzyme, brain-derived neurotrophic factor (BDNF) and magnesium levels in the hippocampus following pre and post-training sleep deprivation. Male Wistar rats (weighing 200 ± 20 g) in below groups were used: control 1, 24, 48 and 72 h SD before training groups, control2, 24 h SD1 after training (being evaluated 24 h after training) and SD2 24 after training (being evaluated 48 h after training). Memory was evaluated 90 min, 24 h or 48 h after training by step-through passive avoidance apparatus. Multiple platforms method was used to induce SD. Oxidant and antioxidant markers including glutathione (GSH), glutathione reductase (GPx), malonedialdehyde (MDA), Total antioxidant concentration, catalase, superoxide dismutase (SOD), magnesium and BDNF were assessed in the hippocampus or/and brain. 72 h pre-training SD impaired short and long-term memory significantly. There was no significant difference in hippocampus oxidant and antioxidant markers compared to control. Hippocampal BDNF and magnesium did not show any changes in all SD groups. Lack of correlation between memory impairment and levels of BDNF, magnesium and/or oxidant and antioxidant balance in the hippocampus is likely to be related to animal locomotor activity in the multiple platforms method. More research is needed to clarify the role of neurochemical systems. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Photometric geodesy of main-belt asteroids. II - Analysis of lightcurves for poles, periods, and shapes

NASA Technical Reports Server (NTRS)

Drummond, J. D.; Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R.

1988-01-01

The assumption that asteroids can be modeled as smooth, featureless, triaxial ellipsoids that rotate about their shortest axes is presently used to study all but one of the 26 asteroids treated in the Weidenschilling et al. (1987) 'photometric geodesy' program. Rotational poles derived from three independent methods are used to determine each asteroid's sidereal period and triaxial ellipsoid axial ratios, together with their associated photometric parameters. The asteroids appear to have rotational poles that do not lie along their orbital planes.

In-Situ Biological Reclamation of Contaminated Ground Water

DTIC Science & Technology

1992-01-01

triaxial cells . I also would like to think Dr. Ed Chian who gave me a kind word when I needed it most. Thank you all. II DEDICATION I wish to dedicate...Tri ax.al Permeability Device Owner’s Manual 103 A-i: Sample Praparation 105 A--2: Triaxial Cell Preparation 107 A--3: Back Pressure Satuaration 108 A...2) 96 vii 3-22 PollutDrit Concentration vs Time (Perm Bd #3) 96 Owner’ Manua I A-I Valve Numbering Scheme 104 Design Drawings B--I Test Cell w

Multiple physical symptoms in a military population: a cross-sectional study

PubMed Central

2013-01-01

Background Medically unexplained symptoms have been reported among both civilians and military personnel exposed to combat. A large number of military personnel deployed to the Gulf War in 1991 reported non-specific symptoms. These symptoms did not constitute a clearly defined syndrome. Post-traumatic stress disorder (PTSD) and to a lesser degree exposure to combat are associated with physical symptoms. Methods This is a cross-sectional study of representative samples of Sri Lanka Navy Special Forces and regular forces deployed in combat areas continuously during a 1-year period. Multiple physical symptoms were elicited using a checklist of 53 symptoms. Cases were defined as individuals with ten or more symptoms. Symptoms of common mental disorder were identified using the General Health Questionnaire 12 (GHQ-12). PTSD was diagnosed using the 17-item National Centre for PTSD checklist civilian version. Results Prevalence of multiple physical symptoms was 10.4% (95% CI 8.11–12.75). Prevalence was significantly less in the Special Forces (5.79%) than in the regular forces (13.35%). The mean number of symptoms reported by those who met the criteria for PTSD was 12.19 (SD 10.58), GHQ caseness 7.87 (SD 7.57) and those without these conditions 2.84 (SD 3.63). After adjusting for socio-demographic and service variables, ‘thought I might be killed’ , ‘coming under small arms fire’ , and ‘coming under mortar, missile and artillery fire’ remained significant. Multiple physical symptoms were associated with functional impairment and poor perceived general health. Conclusions Prevalence of multiple physical symptoms was significantly lower in the Special Forces despite high exposure to potentially traumatic events. More multiple physical symptoms were reported by personnel with PTSD and common mental disorders. Multiple physical symptoms were associated with functional impairment. PMID:23866109

Visualising Three Dimensional Damage and Failure Envelopes: Implications for True Triaxial Deformation

NASA Astrophysics Data System (ADS)

Harland, S. R.; Browning, J.; Healy, D.; Meredith, P. G.; Mitchell, T. M.

2017-12-01

Ultimate failure in brittle rocks is commonly accepted to occur as a coalescence of micro-crack damage into a single failure plane. The geometry and evolution with stress of the cracks (damage) within the medium will play a role in dictating the geometry of the ultimate failure plane. Currently, the majority of experimental studies investigating damage evolution and rock failure use conventional triaxial stress states (σ1 > σ2 = σ3). Results from these tests can easily be represented on a Mohr-Coulomb plot (σn - τ), conveniently allowing the user to determine the geometry of the resultant failure plane. In reality however, stress in the subsurface is generally truly triaxial (σ1 > σ2 > σ3) and in this case, the Mohr-Coulomb failure criterion is inadequate as it incorporates no dependence on the intermediate stress (σ2), which has been shown to play an important role in controlling failure. It has recently been shown that differential stress is the key driver in initiating crack growth, regardless of the mean stress. Polyaxial failure criteria that incorporate the effect of the intermediate stress do exist and include the Modified Lade, Modified Wiebols and Cook, and the Drucker-Prager criteria. However, unlike the Mohr-Coulomb failure criterion, these polyaxial criteria do not offer any prediction of, or insight into, the geometry of the resultant failure plane. An additional downfall of all of the common conventional and polyaxial failure criteria is that they fail to describe the geometry of the damage (i.e. pre-failure microcracking) envelope with progressive stress; it is commonly assumed that the damage envelope is parallel to the ultimate brittle failure envelope. Here we use previously published polyaxial failure data for the Shirahama sandstone and Westerley granite to illustrate that the commonly used Mohr-Coulomb and polyaxial failure criteria do not sufficiently describe or capture failure or damage envelopes under true triaxial stress states. We investigate if and how Mohr-Coulomb type constructions can provide geometrical solutions to truly-triaxial problems. We look to incorporate both the intermediate stress and the differential stress as the controlling parameters in failure and examine the geometry of damage envelopes using damage onset data.

CLUMP-3D: Three-dimensional Shape and Structure of 20 CLASH Galaxy Clusters from Combined Weak and Strong Lensing

NASA Astrophysics Data System (ADS)

Chiu, I.-Non; Umetsu, Keiichi; Sereno, Mauro; Ettori, Stefano; Meneghetti, Massimo; Merten, Julian; Sayers, Jack; Zitrin, Adi

2018-06-01

We perform a three-dimensional triaxial analysis of 16 X-ray regular and 4 high-magnification galaxy clusters selected from the CLASH survey by combining two-dimensional weak-lensing and central strong-lensing constraints. In a Bayesian framework, we constrain the intrinsic structure and geometry of each individual cluster assuming a triaxial Navarro–Frenk–White halo with arbitrary orientations, characterized by the mass {M}200{{c}}, halo concentration {c}200{{c}}, and triaxial axis ratios ({q}{{a}}≤slant {q}{{b}}), and investigate scaling relations between these halo structural parameters. From triaxial modeling of the X-ray-selected subsample, we find that the halo concentration decreases with increasing cluster mass, with a mean concentration of {c}200{{c}}=4.82+/- 0.30 at the pivot mass {M}200{{c}}={10}15{M}ȯ {h}-1. This is consistent with the result from spherical modeling, {c}200{{c}}=4.51+/- 0.14. Independently of the priors, the minor-to-major axis ratio {q}{{a}} of our full sample exhibits a clear deviation from the spherical configuration ({q}{{a}}=0.52+/- 0.04 at {10}15{M}ȯ {h}-1 with uniform priors), with a weak dependence on the cluster mass. Combining all 20 clusters, we obtain a joint ensemble constraint on the minor-to-major axis ratio of {q}{{a}}={0.652}-0.078+0.162 and a lower bound on the intermediate-to-major axis ratio of {q}{{b}}> 0.63 at the 2σ level from an analysis with uniform priors. Assuming priors on the axis ratios derived from numerical simulations, we constrain the degree of triaxiality for the full sample to be { \\mathcal T }=0.79+/- 0.03 at {10}15{M}ȯ {h}-1, indicating a preference for a prolate geometry of cluster halos. We find no statistical evidence for an orientation bias ({f}geo}=0.93+/- 0.07), which is insensitive to the priors and in agreement with the theoretical expectation for the CLASH clusters.

Creating a behavioural classification module for acceleration data: using a captive surrogate for difficult to observe species.

PubMed

Campbell, Hamish A; Gao, Lianli; Bidder, Owen R; Hunter, Jane; Franklin, Craig E

2013-12-15

Distinguishing specific behavioural modes from data collected by animal-borne tri-axial accelerometers can be a time-consuming and subjective process. Data synthesis can be further inhibited when the tri-axial acceleration data cannot be paired with the corresponding behavioural mode through direct observation. Here, we explored the use of a tame surrogate (domestic dog) to build a behavioural classification module, and then used that module to accurately identify and quantify behavioural modes within acceleration collected from other individuals/species. Tri-axial acceleration data were recorded from a domestic dog whilst it was commanded to walk, run, sit, stand and lie-down. Through video synchronisation, each tri-axial acceleration sample was annotated with its associated behavioural mode; the feature vectors were extracted and used to build the classification module through the application of support vector machines (SVMs). This behavioural classification module was then used to identify and quantify the same behavioural modes in acceleration collected from a range of other species (alligator, badger, cheetah, dingo, echidna, kangaroo and wombat). Evaluation of the module performance, using a binary classification system, showed there was a high capacity (>90%) for behaviour recognition between individuals of the same species. Furthermore, a positive correlation existed between SVM capacity and the similarity of the individual's spinal length-to-height above the ground ratio (SL:SH) to that of the surrogate. The study describes how to build a behavioural classification module and highlights the value of using a surrogate for studying cryptic, rare or endangered species.

A Novel Kalman Filter for Human Motion Tracking With an Inertial-Based Dynamic Inclinometer.

PubMed

Ligorio, Gabriele; Sabatini, Angelo M

2015-08-01

Design and development of a linear Kalman filter to create an inertial-based inclinometer targeted to dynamic conditions of motion. The estimation of the body attitude (i.e., the inclination with respect to the vertical) was treated as a source separation problem to discriminate the gravity and the body acceleration from the specific force measured by a triaxial accelerometer. The sensor fusion between triaxial gyroscope and triaxial accelerometer data was performed using a linear Kalman filter. Wrist-worn inertial measurement unit data from ten participants were acquired while performing two dynamic tasks: 60-s sequence of seven manual activities and 90 s of walking at natural speed. Stereophotogrammetric data were used as a reference. A statistical analysis was performed to assess the significance of the accuracy improvement over state-of-the-art approaches. The proposed method achieved, on an average, a root mean square attitude error of 3.6° and 1.8° in manual activities and locomotion tasks (respectively). The statistical analysis showed that, when compared to few competing methods, the proposed method improved the attitude estimation accuracy. A novel Kalman filter for inertial-based attitude estimation was presented in this study. A significant accuracy improvement was achieved over state-of-the-art approaches, due to a filter design that better matched the basic optimality assumptions of Kalman filtering. Human motion tracking is the main application field of the proposed method. Accurately discriminating the two components present in the triaxial accelerometer signal is well suited for studying both the rotational and the linear body kinematics.

Reliability and validity of gait analysis by android-based smartphone.

PubMed

Nishiguchi, Shu; Yamada, Minoru; Nagai, Koutatsu; Mori, Shuhei; Kajiwara, Yuu; Sonoda, Takuya; Yoshimura, Kazuya; Yoshitomi, Hiroyuki; Ito, Hiromu; Okamoto, Kazuya; Ito, Tatsuaki; Muto, Shinyo; Ishihara, Tatsuya; Aoyama, Tomoki

2012-05-01

Smartphones are very common devices in daily life that have a built-in tri-axial accelerometer. Similar to previously developed accelerometers, smartphones can be used to assess gait patterns. However, few gait analyses have been performed using smartphones, and their reliability and validity have not been evaluated yet. The purpose of this study was to evaluate the reliability and validity of a smartphone accelerometer. Thirty healthy young adults participated in this study. They walked 20 m at their preferred speeds, and their trunk accelerations were measured using a smartphone and a tri-axial accelerometer that was secured over the L3 spinous process. We developed a gait analysis application and installed it in the smartphone to measure the acceleration. After signal processing, we calculated the gait parameters of each measurement terminal: peak frequency (PF), root mean square (RMS), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. Remarkable consistency was observed in the test-retest reliability of all the gait parameter results obtained by the smartphone (p<0.001). All the gait parameter results obtained by the smartphone showed statistically significant and considerable correlations with the same parameter results obtained by the tri-axial accelerometer (PF r=0.99, RMS r=0.89, AC r=0.85, CV r=0.82; p<0.01). Our study indicates that the smartphone with gait analysis application used in this study has the capacity to quantify gait parameters with a degree of accuracy that is comparable to that of the tri-axial accelerometer.

Anisotropic Behaviour of Opalinus Clay Through Consolidated and Drained Triaxial Testing in Saturated Conditions

NASA Astrophysics Data System (ADS)

Favero, Valentina; Ferrari, Alessio; Laloui, Lyesse

2018-05-01

This paper investigates the anisotropic hydro-mechanical behaviour of Opalinus Clay shale, the host material currently being considered for the construction of a nuclear waste repository in Switzerland. Consolidated and drained triaxial tests on Opalinus Clay from the Mont Terri URL have been conducted in order to derive information on its strength and stiffness properties. Opalinus Clay specimens were tested both parallel to bedding (P-specimens) and perpendicular to bedding (S-specimens). The considered effective confining stress range (from 2 to 12 MPa) has been selected in order to reproduce possible in situ stress conditions for the repository. In this work, particular attention has been paid to the experimental procedure in order to ensure consolidated conditions and avoid generation of unwanted excess pore water pressure during drained shearing. The Skempton B parameter has been determined for all the tested specimens in order to ensure saturation. Both single-stage and multistage triaxial testing procedures were adopted in the experimental campaign. The results of the triaxial tests highlight an anisotropic elastic response of Opalinus Clay: S-specimens present a more compliant behaviour than P-specimens. The values of the Young modulus are found to increase with the increase in mean effective stress. The analysis of the peak and ultimate shear strength results reveals that the material behaves in a similar manner regardless of the considered direction of loading (P and S directions) with respect to the bedding orientation. Peak and ultimate failure envelopes for Opalinus Clay were derived for the investigated stress range.

Analysis of pelvic movement in the elderly during walking using a posture monitoring system equipped with a triaxial accelerometer and a gyroscope.

PubMed

Ishigaki, Norio; Kimura, Teiji; Usui, Yuki; Aoki, Kaoru; Narita, Nobuyo; Shimizu, Masayuki; Hara, Kazuo; Ogihara, Nobuhide; Nakamura, Koichi; Kato, Hiroyuki; Ohira, Masayoshi; Yokokawa, Yoshiharu; Miyoshi, Kei; Murakami, Narumichi; Okada, Shinpei; Nakamura, Tomokazu; Saito, Naoto

2011-06-03

The incidence of falls in the elderly is increasing with the aging of society and is becoming a major public health issue. From the viewpoint of prevention of falls, it is important to evaluate the stability of the gait in the elderly people. The pelvic movement, which is a critical factor for walking stability, was analyzed using a posture monitoring system equipped with a triaxial accelerometer and a gyroscope. The subjects were 95 elderly people over 60 years of age. The criteria for instability were open-eye standing on one leg for 15s or less, and 11s or more on 3m timed up and go test. Forty subjects who did not meet both of these criteria comprised the stable group, and the remaining 55 subjects comprised the unstable group. Pelvic movement during walking was compared between the two groups. The angle, angular velocity, and acceleration were analyzed based on the wave shape derived from the device worn around the second sacral. The results indicated that pelvic movement was lower in all three directions in the unstable group compared to the stable group, and the changes in the pelvic movement during walking in unstable elderly people were also reduced. This report is the first to evaluate pelvic movement by both a triaxial accelerometer and a triaxial gyroscope simultaneously. The characteristics of pelvic movement during walking can be applied in screening to identify elderly people with instability, which is the main risk factor associated with falls. Copyright © 2011 Elsevier Ltd. All rights reserved.

Uniaxial Compressive Constitutive Relationship of Concrete Confined by Special-Shaped Steel Tube Coupled with Multiple Cavities

PubMed Central

Wu, Haipeng; Cao, Wanlin; Qiao, Qiyun; Dong, Hongying

2016-01-01

A method is presented to predict the complete stress-strain curves of concrete subjected to triaxial stresses, which were caused by axial load and lateral force. The stress can be induced due to the confinement action inside a special-shaped steel tube having multiple cavities. The existing reinforced confined concrete formulas have been improved to determine the confinement action. The influence of cross-sectional shape, of cavity construction, of stiffening ribs and of reinforcement in cavities has been considered in the model. The parameters of the model are determined on the basis of experimental results of an axial compression test for two different kinds of special-shaped concrete filled steel tube (CFT) columns with multiple cavities. The complete load-strain curves of the special-shaped CFT columns are estimated. The predicted concrete strength and the post-peak behavior are found to show good agreement within the accepted limits, compared with the experimental results. In addition, the parameters of proposed model are taken from two kinds of totally different CFT columns, so that it can be concluded that this model is also applicable to concrete confined by other special-shaped steel tubes. PMID:28787886

Uniaxial Compressive Constitutive Relationship of Concrete Confined by Special-Shaped Steel Tube Coupled with Multiple Cavities.

PubMed

Wu, Haipeng; Cao, Wanlin; Qiao, Qiyun; Dong, Hongying

2016-01-29

A method is presented to predict the complete stress-strain curves of concrete subjected to triaxial stresses, which were caused by axial load and lateral force. The stress can be induced due to the confinement action inside a special-shaped steel tube having multiple cavities. The existing reinforced confined concrete formulas have been improved to determine the confinement action. The influence of cross-sectional shape, of cavity construction, of stiffening ribs and of reinforcement in cavities has been considered in the model. The parameters of the model are determined on the basis of experimental results of an axial compression test for two different kinds of special-shaped concrete filled steel tube (CFT) columns with multiple cavities. The complete load-strain curves of the special-shaped CFT columns are estimated. The predicted concrete strength and the post-peak behavior are found to show good agreement within the accepted limits, compared with the experimental results. In addition, the parameters of proposed model are taken from two kinds of totally different CFT columns, so that it can be concluded that this model is also applicable to concrete confined by other special-shaped steel tubes.

Wechsler Adult Intelligence Scale-Fourth Edition performance in relapsing-remitting multiple sclerosis.

PubMed

Ryan, Joseph J; Gontkovsky, Samuel T; Kreiner, David S; Tree, Heather A

2012-01-01

Forty patients with relapsing-remitting multiple sclerosis (MS) completed the 10 core Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) subtests. Means for age and education were 42.05 years (SD = 9.94) and 14.33 years (SD = 2.40). For all participants, the native language was English. The mean duration of MS diagnosis was 8.17 years (SD = 7.75), and the mean Expanded Disability Status Scale (EDSS; Kurtzke, 1983 ) score was 3.73 (SD = 1.41) with a range from 2.0 to 6.5. A control group of healthy individuals with similar demographic characteristics also completed the WAIS-IV and were provided by the test publisher. Compared to controls, patients with MS earned significantly lower subtest and composite scores. The patients' mean scores were consistently in the low-average to average range, and the patterns of performance across groups did not differ significantly, although there was a trend towards higher scores on the Verbal Comprehension Index (VCI) and lower scores on the Processing Speed Index (PSI). Approximately 78% of patients had actual Full Scale IQs that were significantly lower than preillness, demographically based IQ estimates.

Optical coherence tomography angiography retinal vascular network assessment in multiple sclerosis.

PubMed

Lanzillo, Roberta; Cennamo, Gilda; Criscuolo, Chiara; Carotenuto, Antonio; Velotti, Nunzio; Sparnelli, Federica; Cianflone, Alessandra; Moccia, Marcello; Brescia Morra, Vincenzo

2017-09-01

Optical coherence tomography (OCT) angiography is a new method to assess the density of the vascular networks. Vascular abnormalities are considered involved in multiple sclerosis (MS) pathology. To assess the presence of vascular abnormalities in MS and to evaluate their correlation to disease features. A total of 50 MS patients with and without history of optic neuritis (ON) and 46 healthy subjects were included. All underwent spectral domain (SD)-OCT and OCT angiography. Clinical history, Expanded Disability Status Scale (EDSS), Multiple Sclerosis Severity Score (MSSS) and disease duration were collected. Angio-OCT showed a vessel density reduction in eyes of MS patients when compared to controls. A statistically significant reduction in all SD-OCT and OCT angiography parameters was noticed both in eyes with and without ON when compared with control eyes. We found an inverse correlation between SD-OCT parameters and MSSS ( p = 0.003) and between vessel density parameters and EDSS ( p = 0.007). We report a vessel density reduction in retina of MS patients. We highlight the clinical correlation between vessel density and EDSS, suggesting that angio-OCT could be a good marker of disease and of disability in MS.

Typical whole body vibration exposure magnitudes encountered in the open pit mining industry.

PubMed

Howard, Bryan; Sesek, Richard; Bloswick, Don

2009-01-01

According to recent research, a causal link has been established between occupational exposure to whole body vibration and an increased occurrence of low back pain. To aid in the further development of an in-house health and safety program for a large open pit mining facility interested in reducing back pain among its operators, whole body vibration magnitudes were characterized for a range of jobs. Specifically, thirty-five individual jobs from five different areas across the facility were evaluated for tri-axial acceleration levels during normal operating conditions. Tri-axial acceleration magnitudes were categorized into thirteen job groups. Job groups were ranked according to exposure and compared to the ISO 2631-1 standard for health risk assessment. Three of the thirteen job groups produced tri-axial acceleration magnitudes below the ISO 2631-1 low/moderate health caution limit for a twelve hour exposure. Six of the thirteen job groups produced exposures within the moderate health risk range. Four job groups were found to subject operators to WBV acceleration magnitudes above the moderate/high health caution limit.

In situ triaxial magnetic field compensation for the spin-exchange-relaxation-free atomic magnetometer.

PubMed

Fang, Jiancheng; Qin, Jie

2012-10-01

The spin-exchange-relaxation-free (SERF) atomic magnetometer is an ultra-high sensitivity magnetometer, but it must be operated in a magnetic field with strength less than about 10 nT. Magnetic field compensation is an effective way to shield the magnetic field, and this paper demonstrates an in situ triaxial magnetic field compensation system for operating the SERF atomic magnetometer. The proposed hardware is based on optical pumping, which uses some part of the SERF atomic magnetometer itself, and the compensation method is implemented by analyzing the dynamics of the atomic spin. The experimental setup for this compensation system is described, and with this configuration, a residual magnetic field of strength less than 2 nT (±0.38 nT in the x axis, ±0.43 nT in the y axis, and ±1.62 nT in the z axis) has been achieved after compensation. The SERF atomic magnetometer was then used to verify that the residual triaxial magnetic fields were coincident with what were achieved by the compensation system.

Triaxiality and Exotic Rotations at High Spins in 134Ce

DOE PAGES

Petrache, C. M.; Guo, S.; Ayangeakaa, A. D.; ...

2016-06-06

High-spin states in Ce-134 have been investigated using the Cd-116(Ne-22,4n) reaction and the Gammasphere array. The level scheme has been extended to an excitation energy of similar to 30 MeV and spin similar to 54 (h) over bar. Two new dipole bands and four new sequences of quadrupole transitions were identified. Several new transitions have been added to a number of known bands. One of the strongly populated dipole bands was revised and placed differently in the level scheme, resolving a discrepancy between experiment and model calculations reported previously. Configurations are assigned to the observed bands based on cranked Nilsson-Strutinskymore » calculations. A coherent understanding of the various excitations, both at low and high spins, is thus obtained, supporting an interpretation in terms of coexistence of stable triaxial, highly deformed, and superdeformed shapes up to very high spins. Rotations around different axes of the triaxial nucleus, and sudden changes of the rotation axis in specific configurations, are identified, further elucidating the nature of high-spin collective excitations in the A = 130 mass region.« less

Application and Analysis of Measurement Model for Calibrating Spatial Shear Surface in Triaxial Test

NASA Astrophysics Data System (ADS)

Zhang, Zhihua; Qiu, Hongsheng; Zhang, Xiedong; Zhang, Hang

2017-12-01

Discrete element method has great advantages in simulating the contacts, fractures, large displacement and deformation between particles. In order to analyze the spatial distribution of the shear surface in the three-dimensional triaxial test, a measurement model is inserted in the numerical triaxial model which is generated by weighted average assembling method. Due to the non-visibility of internal shear surface in laboratory, it is largely insufficient to judge the trend of internal shear surface only based on the superficial cracks of sheared sample, therefore, the measurement model is introduced. The trend of the internal shear zone is analyzed according to the variations of porosity, coordination number and volumetric strain in each layer. It shows that as a case study on confining stress of 0.8 MPa, the spatial shear surface is calibrated with the results of the rotated particle distribution and the theoretical value with the specific characteristics of the increase of porosity, the decrease of coordination number, and the increase of volumetric strain, which represents the measurement model used in three-dimensional model is applicable.

Design and analysis of miniature tri-axial fluxgate magnetometer

NASA Astrophysics Data System (ADS)

Zhi, Menghui; Tang, Liang; Qiao, Donghai

2017-02-01

The detection technology of weak magnetic field is widely used in Earth resource survey and geomagnetic navigation. Useful magnetic field information can be obtained by processing and analyzing the measurement data from magnetic sensors. A miniature tri-axial fluxgate magnetometer is proposed in this paper. This miniature tri-axial fluxgate magnetometer with ring-core structure has a dynamic range of the Earth’s field ±65,000 nT, resolution of several nT. It has three independent parts placed in three perpendicular planes for measuring three orthogonal magnetic field components, respectively. A field-programmable gate array (FPGA) is used to generate stimulation signal, analog-to-digital (A/D) convertor control signal, and feedback digital-to-analog (D/A) control signal. Design and analysis details are given to improve the dynamic range, sensitivity, resolution, and linearity. Our prototype was measured and compared with a commercial standard Magson fluxgate magnetometer as a reference. The results show that our miniature fluxgate magnetometer can follow the Magson’s change trend well. When used as a magnetic compass, our prototype only has ± 0.3∘ deviation compared with standard magnetic compass.

Identification of Anisotropic Criteria for Stratified Soil Based on Triaxial Tests Results

NASA Astrophysics Data System (ADS)

Tankiewicz, Matylda; Kawa, Marek

2017-09-01

The paper presents the identification methodology of anisotropic criteria based on triaxial test results. The considered material is varved clay - a sedimentary soil occurring in central Poland which is characterized by the so-called "layered microstructure". The strength examination outcomes were identified by standard triaxial tests. The results include the estimated peak strength obtained for a wide range of orientations and confining pressures. Two models were chosen as potentially adequate for the description of the tested material, namely Pariseau and its conjunction with the Jaeger weakness plane. Material constants were obtained by fitting the model to the experimental results. The identification procedure is based on the least squares method. The optimal values of parameters are searched for between specified bounds by sequentially decreasing the distance between points and reducing the length of the searched range. For both considered models the optimal parameters have been obtained. The comparison of theoretical and experimental results as well as the assessment of the suitability of selected criteria for the specified range of confining pressures are presented.

A novel portable energy dispersive X-ray fluorescence spectrometer with triaxial geometry

NASA Astrophysics Data System (ADS)

Pessanha, S.; Alves, M.; Sampaio, J. M.; Santos, J. P.; Carvalho, M. L.; Guerra, M.

2017-01-01

The X-ray fluorescence technique is a powerful analytical tool with a broad range of applications such as quality control, environmental contamination by heavy metals, cultural heritage, among others. For the first time, a portable energy dispersive X-ray fluorescence spectrometer was assembled, with orthogonal triaxial geometry between the X-ray tube, the secondary target, the sample and the detector. This geometry reduces the background of the measured spectra by reducing significantly the Bremsstrahlung produced in the tube through polarization in the secondary target and in the sample. Consequently, a practically monochromatic excitation energy is obtained. In this way, a better peak-background ratio is obtained compared to similar devices, improving the detection limits and leading to superior sensitivity. The performance of this setup is compared with the one of a benchtop setup with triaxial geometry and a portable setup with planar geometry. Two case studies are presented concerning the analysis of a 18th century paper document, and the bone remains of an individual buried in the early 19th century.

The Hippo effector Yorkie controls normal tissue growth by antagonizing scalloped-mediated default repression.

PubMed

Koontz, Laura M; Liu-Chittenden, Yi; Yin, Feng; Zheng, Yonggang; Yu, Jianzhong; Huang, Bo; Chen, Qian; Wu, Shian; Pan, Duojia

2013-05-28

The Hippo tumor suppressor pathway restricts tissue growth by inactivating the transcriptional coactivator Yki. Although Sd has been implicated as a DNA-binding transcription factor partner for Yki and can genetically account for gain-of-function Yki phenotypes, how Yki regulates normal tissue growth remains a long-standing puzzle because Sd, unlike Yki, is dispensable for normal growth in most Drosophila tissues. Here we show that the yki mutant phenotypes in multiple developmental contexts are rescued by inactivation of Sd, suggesting that Sd functions as a default repressor and that Yki promotes normal tissue growth by relieving Sd-mediated default repression. We further identify Tgi as a cofactor involved in Sd's default repressor function and demonstrate that the mammalian ortholog of Tgi potently suppresses the YAP oncoprotein in transgenic mice. These findings fill a major gap in Hippo-mediated transcriptional regulation and open up possibilities for modulating the YAP oncoprotein in cancer and regenerative medicine. Copyright © 2013 Elsevier Inc. All rights reserved.

Anatomical Directional Dissimilarities in Tri-axial Swallowing Accelerometry Signals

PubMed Central

Movahedi, Faezeh; Kurosu, Atsuko; Coyle, James L.; Perera, Subashan

2017-01-01

Swallowing accelerometry is a non-invasive approach currently under consideration as an instrumental screening test for swallowing difficulties, with most current studies focusing on the swallowing vibrations in the anterior-posterior (A-P) and superior-interior (S-I) directions. However, the displacement of the hyolaryngeal structure during the act of swallowing in patients with dysphagia involves declination of the medial-lateral (M-L), which suggests that the swallowing vibrations in the M-L direction have the ability to reveal additional details about the swallowing function. With this motivation, we performed a broad comparison of the swallowing vibrations in all three anatomical directions. Tri-axial swallowing accelerometry signals were concurrently collected from 72 dysphagic patients undergoing videofluoroscopic evaluation of swallowing (mean age: 63.94 ± 12.58 years period). Participants swallowed one or more thickened liquids with different consistencies including thin-thick liquids, nectar-thick liquids, and pudding-thick liquids with either a comfortable self-selected volume from a cup or a controlled volume by the examiner from a 5ml spoon. Swallows were grouped based on the viscosity of swallows and the participant’s stroke history. Then, a comprehensive set of features was extracted in multiple signal domains from 881 swallows. The results highlighted inter-axis dissimilarities among tri-axial swallowing vibrations including the extent of variability in the amplitude of signals, the degree of predictability of signals, and the extent of disordered behavior of signals in time-frequency domain. First, the upward movement of the hyolaryngeal structure, representing the S-I signals, were actually more variable in amplitude and showed less predictable behavior than the sideways and forward movements, representing the A-P and M-L signals, during swallowing. Second, the S-I signals, which represent the upward movement of the hyolaryngeal structure, behaved more disordered in the time-frequency domain than the sideways movement, M-L signals, in all groups of study except for the pudding swallows in the stroke group. Third, considering the viscosity and the participant’s pathology, thin liquid swallows in the non-stroke group presented the most directional differences among all groups of study. In summary, despite some directional dissimilarities, M-L axis accelerometry characteristics are similar to those of the two other axes. This indicates that M-L axis characteristics, which cannot be observed in videofluoroscopic images, can be adequately derived from the A-P and S-I axes. PMID:27295677

Anatomical Directional Dissimilarities in Tri-axial Swallowing Accelerometry Signals.

PubMed

Movahedi, Faezeh; Kurosu, Atsuko; Coyle, James L; Perera, Subashan; Sejdic, Ervin

2017-05-01

Swallowing accelerometry is a noninvasive approach currently under consideration as an instrumental screening test for swallowing difficulties, with most current studies focusing on the swallowing vibrations in the anterior-posterior (A-P) and superior-inferior (S-I) directions. However, the displacement of the hyolaryngeal structure during the act of swallowing in patients with dysphagia involves declination of the medial-lateral (M-L), which suggests that the swallowing vibrations in the M-L direction have the ability to reveal additional details about the swallowing function. With this motivation, we performed a broad comparison of the swallowing vibrations in all three anatomical directions. Tri-axial swallowing accelerometry signals were concurrently collected from 72 dysphagic patients undergoing videofluoroscopic evaluation of swallowing (mean age: 63.94 ± 12.58 years period). Participants swallowed one or more thickened liquids with different consistencies including thin-thick liquids, nectar-thick liquids, and pudding-thick liquids with either a comfortable self-selected volume from a cup or a controlled volume by the examiner from a 5-ml spoon. Swallows were grouped based on the viscosity of swallows and the participant's stroke history. Then, a comprehensive set of features was extracted in multiple signal domains from 881 swallows. The results highlighted inter-axis dissimilarities among tri-axial swallowing vibrations including the extent of variability in the amplitude of signals, the degree of predictability of signals, and the extent of disordered behavior of signals in time-frequency domain. First, the upward movement of the hyolaryngeal structure, representing the S-I signals, were actually more variable in amplitude and showed less predictable behavior than the sideways and forward movements, representing the A-P and M-L signals, during swallowing. Second, the S-I signals, which represent the upward movement of the hyolaryngeal structure, behaved more disordered in the time-frequency domain than the sideways movement, M-L signals, in all groups of study except for the pudding swallows in the stroke group. Third, considering the viscosity and the participant's pathology, thin liquid swallows in the nonstroke group presented the most directional differences among all groups of study. In summary, despite some directional dissimilarities, M-L axis accelerometry characteristics are similar to those of the two other axes. This indicates that M-L axis characteristics, which cannot be observed in videofluoroscopic images, can be adequately derived from the A-P and S-I axes.

SU-E-T-395: Evaluation of Multiple Brain Metastases Stereotactic Treatment Planning in Cyberknife Versus Linac

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

Vikraman, S; Rajesh, Thiyagarajan; Karrthick, Kp

2015-06-15

Purpose: The purpose of this study was to evaluate multiple brain metastases stereotactic treatment planning of Cyberknife versus linac using dose volume based indices. Methods: Fifteen multiple brain metastases patients were taken for this study from Cyberknife Multiplan TPSv4.6.0. All these patients underwent stereotactic treatment in Cyberknife. For each patient VMAT stereotactic treatment plan was generated in MONACO TPSv5.0 using Elekta beam modulator MLC and matched the delivered plan. A median dose of 8.5Gy(range 7–12Gy) per fraction was prescribed. Tumor volume was in the range of 0.06–4.33cc. Treatment plan quality was critically evaluated by comparing DVH indices such as D98,more » D95, CI, and HI for target volumes. Maximum point doses and volume doses were evaluated for critical organs. Results: For each case, target coverage of D98 was achieved with 100% prescription dose with SD of 0.29% and 0.41% in Linac and Cyberknife respectively. The average conformity index(CI) of 1.26±0.0796 SD for Cyberknife and 1.92±0.60SD for linac were observed. Better homogeneity Index (HI) of 1.17±0.09SD was observed in linac as compared to Cyberknife HI of 1.24±0.05SD.All the critical organ doses were well within tolerance limit in both linac and Cyberknife plans. There is no significant difference of maximum point doses for brainstem and optic chiasm. Treatment time and number of monitor units are more in Cyberknife compared to linac. The average volume receiving 12Gy in whole brain was 6% and 12% for Cyberknife and linac respectively. 1000cc of whole brain received 60% lesser dose in Linac compared to Cyberknife in all cases. Conclusion: The study shows that dosimetrically comparable plans are achievable Cyberknife and Linac. However, a better conformity, target coverage, lesser OAR dose is achieved with Cyberknife due to greater degrees of freedom with robotic gantry and smaller collimator for multiple targets.« less

Validation of triaxial accelerometers to measure the lying behaviour of adult domestic horses.

PubMed

DuBois, C; Zakrajsek, E; Haley, D B; Merkies, K

2015-01-01

Examining the characteristics of an animal's lying behaviour, such as frequency and duration of lying bouts, has become increasingly relevant for animal welfare research. Triaxial accelerometers have the advantage of being able to continuously monitor an animal's standing and lying behaviour without relying on live observations or video recordings. Multiple models of accelerometers have been validated for use in monitoring dairy cattle; however, no units have been validated for use in equines. This study tested Onset Pendant G data loggers attached to the hind limb of each of two mature Standardbred horses for a period of 5 days. Data loggers were set to record their position every 20 s. Horses were monitored via live observations during the day and by video recordings during the night to compare activity against accelerometer data. All lying events occurred overnight (three to five lying bouts per horse per night). Data collected from the loggers was converted and edited using a macro program to calculate the number of bouts and the length of time each animal spent lying down by hour and by day. A paired t-test showed no significant difference between the video observations and the output from the data loggers (P=0.301). The data loggers did not distinguish standing hipshot from standing square. Predictability, sensitivity, and specificity were all >99%. This study has validated the use of Onset Pendant G data loggers to determine the frequency and duration of standing and lying bouts in adult horses when set to sample and register readings at 20 s intervals.

A Triaxial Applicator for the Measurement of the Electromagnetic Properties of Materials

PubMed Central

2018-01-01

The design, analysis, and fabrication of a prototype triaxial applicator is described. The applicator provides both reflected and transmitted signals that can be used to characterize the electromagnetic properties of materials in situ. A method for calibrating the probe is outlined and validated using simulated data. Fabrication of the probe is discussed, and measured data for typical absorbing materials and for the probe situated in air are presented. The simulations and measurements suggest that the probe should be useful for measuring the properties of common radar absorbing materials under usual in situ conditions. PMID:29382122

Parametric design of tri-axial nested Helmholtz coils

NASA Astrophysics Data System (ADS)

Abbott, Jake J.

2015-05-01

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Parametric design of tri-axial nested Helmholtz coils.

PubMed

Abbott, Jake J

2015-05-01

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Parametric design of tri-axial nested Helmholtz coils

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

Abbott, Jake J., E-mail: jake.abbott@utah.edu

This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

Nuclear shapes: Quest for triaxiality in 86Ge and the shape of 98Zr

NASA Astrophysics Data System (ADS)

Werner, V.; Lettmann, M.; Lizarazo, C.; Witt, W.; Cline, D.; Carpenter, M.; Doornenbal, P.; Obertelli, A.; Pietralla, N.; Savard, G.; Söderström, P.-A.; Wu, C.-Y.; Zhu, S.

2018-05-01

The region of neutron-rich nuclei above the N = 50 magic neutron shell closure encompasses a rich variety of nuclear structure, especially shapeevolutionary phenomena. This can be attributed to the complexity of sub-shell closures, their appearance and disappearance in the region, such as the N = 56 sub shell or Z = 40 for protons. Structural effects reach from a shape phase transition in the Zr isotopes, over shape coexistence between spherical, prolate, and oblate shapes, to possibly rigid triaxial deformation. Recent experiments in this region and their main physics viewpoints are summarized.

Noncircular outer disks in unbarred S0 galaxies: NGC 502 and NGC 5485

NASA Astrophysics Data System (ADS)

Sil'chenko, O. K.

2016-03-01

Highly noncircular outer stellar disks have been detected in two SA0 (unbarred) galaxies by comparing the spectroscopic data on the rotation of stars and the photometric data on the shape and orientation of isophotes. In NGC 502, the oval distortion of the disk is manifested in the shape of the inner and outer elliptical rings occupying wide radial zones between the bulge and the disk and at the outer disk edge; such a structure can be a consequence of the so-called "dry minor merger," multiple cannibalization of gas-free satellites. In NGC 5485, the stellar kinematics is absolutely unrelated to the orientation of isophotes in the disk region, and for this galaxy the conclusion about its global triaxial structure is unavoidable.

Pilates exercise training vs. physical therapy for improving walking and balance in people with multiple sclerosis: a randomized controlled trial.

PubMed

Kalron, Alon; Rosenblum, Uri; Frid, Lior; Achiron, Anat

2017-03-01

Evaluate the effects of a Pilates exercise programme on walking and balance in people with multiple sclerosis and compare this exercise approach to conventional physical therapy sessions. Randomized controlled trial. Multiple Sclerosis Center, Sheba Medical Center, Tel-Hashomer, Israel. Forty-five people with multiple sclerosis, 29 females, mean age (SD) was 43.2 (11.6) years; mean Expanded Disability Status Scale (S.D) was 4.3 (1.3). Participants received 12 weekly training sessions of either Pilates ( n=22) or standardized physical therapy ( n=23) in an outpatient basis. Spatio-temporal parameters of walking and posturography parameters during static stance. Functional tests included the Time Up and Go Test, 2 and 6-minute walk test, Functional Reach Test, Berg Balance Scale and the Four Square Step Test. In addition, the following self-report forms included the Multiple Sclerosis Walking Scale and Modified Fatigue Impact Scale. At the termination, both groups had significantly increased their walking speed ( P=0.021) and mean step length ( P=0.023). According to the 2-minute and 6-minute walking tests, both groups at the end of the intervention program had increased their walking speed. Mean (SD) increase in the Pilates and physical therapy groups were 39.1 (78.3) and 25.3 (67.2) meters, respectively. There was no effect of group X time in all instrumented and clinical balance and gait measures. Pilates is a possible treatment option for people with multiple sclerosis in order to improve their walking and balance capabilities. However, this approach does not have any significant advantage over standardized physical therapy.

Multiple-file vs. single-file endodontics in dental practice: a study in routine care.

PubMed

Bartols, Andreas; Laux, Gunter; Walther, Winfried

2016-01-01

Little is known about the differences of rotary multiple file endodontic therapy and single-file reciprocating endodontic treatment under routine care conditions in dental practice. This multicenter study was performed to compare the outcome of multiple-file (MF) and single-file (SF) systems for primary root canal treatment under conditions of general dental practice regarding reduction of pain with a visual analogue scale (VAS 100), improvement of oral-health-related quality of life (OHRQoL) with the german short version of the oral health impact profile (OHIP-G-14) and the speed of root canal preparation. Ten general dental practitioners (GDPs) participated in the study as practitioner-investigators (PI). In the first five-month period of the study, the GDPs treated patients with MF systems. After that, the GDPs treated the patients in the second five-month period with a SF system (WaveOne). The GDPs documented the clinical findings at the beginning and on completion of treatment. The patients documented their pain and OHRQoL before the beginning and before completion of treatment. A total of 599 patients were included in the evaluation. 280 patients were in the MF group, 319 were in the SF WaveOne group. In terms of pain reduction and improvement in OHIP-G-14, the improvement in both study groups (MF and SF) was very similar based on univariate analysis methods. Pain reduction was 34.4 (SD 33.7) VAS (MF) vs. 35.0 (SD 35.4) VAS (SF) ( p  = 0.840) and the improvement in OHIP-G-14 score was 9.4 (SD 10.3) (MF) vs. 8.5 (SD 10.2) (SF) ( p  = 0.365). The treatment time per root canal was 238.9 s (SD 206.2 s) (MF) vs. 146.8 sec. (SD 452.8 sec) (SF) ( p  = 0.003). Regarding improvement of endodontic pain and OHRQoL measure with OHIP-G-14, there were no statistical significant differences between the SF und the MF systems. WaveOne-prepared root canals significantly faster than MF systems.

Management of Musculoskeletal Conditions in Rural South Australia: A Randomised Controlled Trial.

PubMed

Dent, E; Hoon, E; Karnon, J; Kitson, A; Dollard, J; Newbury, J; Harvey, G; Gill, T; Beilby, J

2017-01-01

With age, the prevalence of musculoskeletal conditions increases markedly. This rural-based study determined the benefits of two approaches for managing musculoskeletal conditions: a multiple-component 'Self-management Plus' intervention, and usual care. The intervention combined self-management education with physical activity and health professional support. 6-month outcomes included: Clinical Global Impression-Improvement Scale (CGI-IS) and Quality of Life (QoL). A total of 145 people were recruited; mean (SD) age was 66.1 (11.1) and 63.3 (10.9) years for intervention and control groups respectively. The intervention resulted in greater improvements in global functioning (CGI-IS mean (SD) = 3.2 (1.3)) than usual care (CGI-IS mean (SD) = 4.2 (1.5)). There was no difference in QoL improvement between study groups. A multiple-component 'Self-management Plus' intervention had a positive effect on physical functioning for older adults with musculoskeletal conditions. However, recruitment and retention of participants was problematic, which raises questions about the intervention's feasibility in its current form.

Formal Uncertainty and Dispersion of Single and Double Difference Models for GNSS-Based Attitude Determination.

PubMed

Chen, Wen; Yu, Chao; Dong, Danan; Cai, Miaomiao; Zhou, Feng; Wang, Zhiren; Zhang, Lei; Zheng, Zhengqi

2017-02-20

With multi-antenna synchronized global navigation satellite system (GNSS) receivers, the single difference (SD) between two antennas is able to eliminate both satellite and receiver clock error, thus it becomes necessary to reconsider the equivalency problem between the SD and double difference (DD) models. In this paper, we quantitatively compared the formal uncertainties and dispersions between multiple SD models and the DD model, and also carried out static and kinematic short baseline experiments. The theoretical and experimental results show that under a non-common clock scheme the SD and DD model are equivalent. Under a common clock scheme, if we estimate stochastic uncalibrated phase delay (UPD) parameters every epoch, this SD model is still equivalent to the DD model, but if we estimate only one UPD parameter for all epochs or take it as a known constant, the SD (here called SD2) and DD models are no longer equivalent. For the vertical component of baseline solutions, the formal uncertainties of the SD2 model are two times smaller than those of the DD model, and the dispersions of the SD2 model are even more than twice smaller than those of the DD model. In addition, to obtain baseline solutions, the SD2 model requires a minimum of three satellites, while the DD model requires a minimum of four satellites, which makes the SD2 more advantageous in attitude determination under sheltered environments.

Formal Uncertainty and Dispersion of Single and Double Difference Models for GNSS-Based Attitude Determination

PubMed Central

Chen, Wen; Yu, Chao; Dong, Danan; Cai, Miaomiao; Zhou, Feng; Wang, Zhiren; Zhang, Lei; Zheng, Zhengqi

2017-01-01

With multi-antenna synchronized global navigation satellite system (GNSS) receivers, the single difference (SD) between two antennas is able to eliminate both satellite and receiver clock error, thus it becomes necessary to reconsider the equivalency problem between the SD and double difference (DD) models. In this paper, we quantitatively compared the formal uncertainties and dispersions between multiple SD models and the DD model, and also carried out static and kinematic short baseline experiments. The theoretical and experimental results show that under a non-common clock scheme the SD and DD model are equivalent. Under a common clock scheme, if we estimate stochastic uncalibrated phase delay (UPD) parameters every epoch, this SD model is still equivalent to the DD model, but if we estimate only one UPD parameter for all epochs or take it as a known constant, the SD (here called SD2) and DD models are no longer equivalent. For the vertical component of baseline solutions, the formal uncertainties of the SD2 model are two times smaller than those of the DD model, and the dispersions of the SD2 model are even more than twice smaller than those of the DD model. In addition, to obtain baseline solutions, the SD2 model requires a minimum of three satellites, while the DD model requires a minimum of four satellites, which makes the SD2 more advantageous in attitude determination under sheltered environments. PMID:28230753

Nuclear chirality, a model and the data

NASA Astrophysics Data System (ADS)

Starosta, K.; Koike, T.

2017-09-01

In the last decade, the manifestation of chirality in atomic nuclei has become the subject of numerous experimental and theoretical studies. The common feature of current model calculations is that the chiral geometry of angular momentum coupling is extracted from expectation values of orientation operators, rather than being a starting point in construction of a model. However, using the particle-hole coupling model for triaxial odd-odd nuclei it is possible to construct a basis which contains right-handed, left-handed and planar states of angular momentum coupling. If this basis is used, the chirality is an explicit rather than an extracted feature as in any other models with non-chiral bases. The time-reversal symmetry, which relates the basis states of opposite handedness, can be used to reduce the dimension of matrices for diagonalization of the model Hamiltonian, proving the effectiveness of this approach. Moreover, the final model eigenstate wave functions show a concentration of amplitudes among a relatively small number (˜1%) of components compared to the full model space. In that sense, the ‘chiral’ basis provides a useful tool to examine model predictions providing direct insight into the structure of doublet states. In this work, similarities and differences between the rotational behaviour of an axial and triaxial body provide a starting point for derivation of the basis optimal for valence nucleon coupling to an axial and a triaxial core. The derived ‘chiral’ basis is optimal for coupling of a valence particle and hole to the triaxial core. Model predictions are presented and discussed. A comprehensive review of current experimental data on observed chiral band candidates is also provided.

The intrinsic shape of bulges in the CALIFA survey

NASA Astrophysics Data System (ADS)

Costantin, L.; Méndez-Abreu, J.; Corsini, E. M.; Eliche-Moral, M. C.; Tapia, T.; Morelli, L.; Dalla Bontà, E.; Pizzella, A.

2018-02-01

Context. The intrinsic shape of galactic bulges in nearby galaxies provides crucial information to separate bulge types. Aims: We aim to derive accurate constraints to the intrinsic shape of bulges to provide new clues on their formation mechanisms and set new limitations for future simulations. Methods: We retrieved the intrinsic shape of a sample of CALIFA bulges using a statistical approach. Taking advantage of GalMer numerical simulations of binary mergers we estimated the reliability of the procedure. Analyzing the i-band mock images of resulting lenticular remnants, we studied the intrinsic shape of their bulges at different galaxy inclinations. Finally, we introduced a new (B/A, C/A) diagram to analyze possible correlations between the intrinsic shape and the properties of bulges. Results: We tested the method on simulated lenticular remnants, finding that for galaxies with inclinations of 25° ≤ θ ≤ 65° we can safely derive the intrinsic shape of their bulges. We found that our CALIFA bulges tend to be nearly oblate systems (66%), with a smaller fraction of prolate spheroids (19%), and triaxial ellipsoids (15%). The majority of triaxial bulges are in barred galaxies (75%). Moreover, we found that bulges with low Sérsic indices or in galaxies with low bulge-to-total luminosity ratios form a heterogeneous class of objects; additionally, bulges in late-type galaxies or in less massive galaxies have no preference for being oblate, prolate, or triaxial. On the contrary, bulges with high Sérsic index, in early-type galaxies, or in more massive galaxies are mostly oblate systems. Conclusions: We concluded that various evolutionary pathways may coexist in galaxies, with merging events and dissipative collapse being the main mechanisms driving the formation of the most massive oblate bulges and bar evolution reshaping the less massive triaxial bulges.

Growth of (Y1-x Ca x )Ba2Cu4O8 in ambient pressure and its tri-axial magnetic alignment

NASA Astrophysics Data System (ADS)

Horii, S.; Yamaki, M.; Shimoyama, J.; Kishio, K.; Doi, T.

2015-10-01

We report the growth of single crystals in ambient pressure and tri-axial orientation under modulated rotation magnetic fields (MRFs) for (Y1-x Ca x )Ba2Cu4O8 [(Y1-x Ca x )124] with x ≤ 0.1. Rectangular (Y1-x Ca x )124 crystals approximately 50 μm in size have been successfully grown for x ≤ 0.1 in a growth temperature region from 650 °C to 750 °C. Their critical temperatures increased with x and exhibited approximately 91 K for x = 0.1. By applying an MRF of 10 T, pulverised powders of (Y1-x Ca x )124 were tri-axially aligned in epoxy resin at room temperature in a whole x region below x = 0.1. The magnitude relationship of the magnetic susceptibilities (χ) along crystallographic directions for (Y1-x Ca x )124 was χ c > χ a > χ b at room temperature and was unchanged with a change in x. From changes in the degrees of the c-axis and the in-plane orientation (Δω) for the (Y1-x Ca x )124 powder samples aligned under three different MRF conditions, it was found that MRFs above at least 1 T were required to achieve almost complete tri-axial alignment with Δω < 5°. Irreversibility lines for H//c were successfully determined even from the powder samples by the introduction of magnetic alignment without using single crystalline samples. The present study indicates that magnetic alignment is a useful process for the fabrication of quasi-single-crystals from the perspective of solid-state physics and the production of cuprate superconducting materials.

Investigating Simulated Driving Errors in Amnestic Single- and Multiple-Domain Mild Cognitive Impairment.

PubMed

Hird, Megan A; Vesely, Kristin A; Fischer, Corinne E; Graham, Simon J; Naglie, Gary; Schweizer, Tom A

2017-01-01

The areas of driving impairment characteristic of mild cognitive impairment (MCI) remain unclear. This study compared the simulated driving performance of 24 individuals with MCI, including amnestic single-domain (sd-MCI, n = 11) and amnestic multiple-domain MCI (md-MCI, n = 13), and 20 age-matched controls. Individuals with MCI committed over twice as many driving errors (20.0 versus 9.9), demonstrated difficulty with lane maintenance, and committed more errors during left turns with traffic compared to healthy controls. Specifically, individuals with md-MCI demonstrated greater driving difficulty compared to healthy controls, relative to those with sd-MCI. Differentiating between different subtypes of MCI may be important when evaluating driving safety.

Association of Total Marine Fatty Acids, Eicosapentaenoic and Docosahexaenoic Acids, With Aortic Stiffness in Koreans, Whites, and Japanese Americans

PubMed Central

2013-01-01

BACKGROUND Few previous studies have reported the association of aortic stiffness with marine n-3 fatty acids (Fas) in the general population. The aim of this study was to determine the combined and independent associations of 2 major marine n-3 FAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with aortic stiffness evaluated using carotid–femoral pulse wave velocity (cfPWV) in Korean, white, and Japanese American men. METHODS A population-based sample of 851 middle-aged men (299 Koreans, 266 whites, and 286 Japanese Americans) was examined for cfPWV during 2002–2006. Serum FAs, including EPA and DHA, were measured as a percentage of total FAs using gas chromatography. Multiple regression analysis was used to examine the association of EPA and DHA with cfPWV after adjusting for blood pressure and other confounders. RESULTS Mean EPA and DHA levels were 1.9 (SD = 1.0) and 4.8 (SD = 1.4) for Koreans, 0.8 (SD = 0.6) and 2.4 (SD = 1.2) for whites, and 1.0 (SD = 1.0) and 3.2 (SD = 1.4) for Japanese Americans. Both EPA and DHA were significantly higher in Koreans than in the other 2 groups (P < 0.01). Multiple regression analyses in Koreans showed that cfPWV had a significant inverse association with total marine n-3 FAs and with EPA alone after adjusting for blood pressure and other potential confounders. In contrast, there was no significant association of cfPWV with DHA. Whites and Japanese Americans did not show any significant associations of cfPWV with total marine n-3 FAs, EPA, or DHA. CONCLUSIONS High levels of EPA observed in Koreans have an inverse association with aortic stiffness. PMID:23820020

Randomized Controlled Trial to Examine the Impact of Aquatic Exercise Training on Functional Capacity, Balance, and Perceptions of Fatigue in Female Patients With Multiple Sclerosis.

PubMed

Kargarfard, Mehdi; Shariat, Ardalan; Ingle, Lee; Cleland, Joshua A; Kargarfard, Mina

2018-02-01

To assess the effects of an 8-week aquatic exercise training program on functional capacity, balance, and perceptions of fatigue in women with multiple sclerosis (MS). Randomized controlled design. Referral center of an MS society. Women (N=32; mean age ± SD, 36.4±8.2y) with diagnosed relapsing-remitting MS. After undergoing baseline testing by a neurologist, participants were allocated to either an intervention (aquatic training program, n=17) or a control group (n=15). The intervention consisted of an 8-week aquatic training program (3 supervised training sessions per week; session duration, 45-60min; 50%-75% estimated maximum heart rate). Six-minute walk test (6-MWT), balance (Berg Balance Scale [BBS]), and perceptions of fatigue (Modified Fatigue Impact Scale; [MFIS]) at baseline and after the 8-week intervention. Differences over time between the experimental and control groups were assessed by a 2×2 (group by time) repeated-measures analysis of variance. Thirty-two women completed the 8-week aquatic training intervention (experimental group, n=17; control group, n=15). All outcome measures improved in the experimental group: 6-MWT performance (pretest mean ± SD, 451±58m; posttest mean ± SD, 503±57m; P<.001); BBS (pretest mean ± SD, 53.59±1.70; posttest mean ± SD, 55.18±1.18; P<.001), and MFIS (pretest mean ± SD, 43.1±14.6; posttest mean ± SD, 32.8±5.9; P<.01). A significant group-by-time interaction was evident between the experimental and control groups for 6-MWT (P<.001, partial eta 2 [η p 2 ]=.551), BBS (P<.001, η p 2 =.423), and MFIS (P<.001, η p 2 =.679). Aquatic exercise training improved functional capacity, balance, and perceptions of fatigue in women with MS. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Contribution of vertebral deformities to chronic back pain and disability. The Study of Osteoporotic Fractures Research Group

NASA Technical Reports Server (NTRS)

Ettinger, B.; Black, D. M.; Nevitt, M. C.; Rundle, A. C.; Cauley, J. A.; Cummings, S. R.; Genant, H. K.

1992-01-01

Among 2992 white women aged 65-70 years recruited from population-based listings, we measured radiographic vertebral dimensions of T5-L4 and calculated ratios of heights: anterior/posterior, mid/posterior, and posterior/posterior of either adjacent vertebra. The degree of deformity for each vertebra was analyzed in terms of the number of standard deviations (SD) that ratio differed from the mean ratio calculated for the same vertebral level in this population. We correlated the severity of each woman's worst vertebral deformity with back pain, back disability in six activities of daily living, and height loss since age 25. Only 39.4% of the cohort had no vertebral deformity; 10.2% had a deformity greater than or equal to 4 SD. Vertebral deformities less than 4 SD below the mean were not associated with increased back pain, disability, or loss of height. In contrast, women whose deformity was greater than or equal to 4 SD had a 1.9 (95% CI, 1.5-2.4) times higher risk of moderate to severe back pain and a 2.6 (95% CI, 1.7-3.9) times higher risk of disability involving the back; they were also 2.5 (95% CI, 2.0-3.2) times more likely to have lost greater than or equal to 4 cm in height. All three types of vertebral deformity (wedge, end plate, and crush) were equally associated with these outcomes. Multiple deformities less than 4 SD did not increase the likelihood of these three outcomes, but multiple deformities greater than or equal to 4 SD tended to be associated with increased back pain, disability, and height loss. This large cross-sectional study suggests that vertebral deformities cause substantial pain, disability, or loss of height only if vertebral height ratios fall 4 SD below the normal mean. Much back pain could not be attributed to vertebral deformities, suggesting other causes.

Evaluation of the association between sexual dysfunction and demyelinating plaque location and number in female multiple sclerosis patients.

PubMed

Solmaz, Volkan; Ozlece, Hatice Kose; Him, Aydın; Güneş, Ayfer; Cordano, Christian; Aksoy, Durdane; Çelik, Yahya

2018-04-17

Purpose To investigate the frequency of sexual dysfunction (SD) in female multiple sclerosis (MS) patients and to explore its association with the location and number of demyelinating lesions. Material and Methods We evaluated 42 female patients and 41 healthy subjects. All patients underwent neurological examination and 1.5 T brain and full spinal MRI. All subjects completed the female sexual function index (FSFI), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Short-Form 36 Quality of Life Scale (SF-36). All participants were also evaluated for serum thyroid stimulating hormone (TSH), T4, estradiol, and total testosterone. Results No statistically significant differences between the MS and control groups were found for age, body mass index (BMI), serum TSH, T4, E2, and total testosterone level. MS patients had a statistically significantly lower FSFI and SF-36 scores and higher BDI and BAI scores compared with healthy subjects. The location and number of demyelinating lesions were not associated with SD. Conclusion In our cohort, this difference in SD appears unrelated to the location and number of demyelinating lesions. These findings highlight the importance of the assessment and treatment of psychiatric comorbidities, such as depression and anxiety, in MS patients reporting SD.

Sexual dysfunction in multiple sclerosis: A 6-year follow-up study.

PubMed

Kisic-Tepavcevic, Darija; Pekmezovic, Tatjana; Trajkovic, Goran; Stojsavljevic, Nebojsa; Dujmovic, Irena; Mesaros, Sarlota; Drulovic, Jelena

2015-11-15

Sexual dysfunction (SD) is a common but often overlooked and undertreated symptom in multiple sclerosis (MS). The purpose of our longitudinal study was to explore the changes in the level of sexual functioning in MS cohort after a period of 3 and 6 years of follow-up, as well as to investigate the predictors of changes in SD during the period of observation. The study population comprise a cohort of 93 patients with MS (McDonald's criteria, 2001) who were assessed at three time points during the study (baseline, and at the 3- and 6-year follow-up). The presence and severity of SD was quantified by Szasz sexual functioning scale. Independent predictors of the ordinal-scaled measure of sexual problems were identified using a generalized linear mixed regression models. The number of reported SD symptoms increased markedly for both genders during the whole period of observation. Duration of follow-up, age, level of physical disability, depression and fatigue were identified as independent prognostic factors for deterioration of sexual functioning in patients with MS during the 6-year follow-up. Our study provides insight into dynamics of change in sexual function among patients with MS and predictors of change, over the period of 6 years. Copyright © 2015 Elsevier B.V. All rights reserved.

Feasibility of using a reliable automated Doppler flow velocity measurements for research and clinical practices

NASA Astrophysics Data System (ADS)

Zolgharni, Massoud; Dhutia, Niti M.; Cole, Graham D.; Willson, Keith; Francis, Darrel P.

2014-03-01

Echocardiographers are often unkeen to make the considerable time investment to make additional multiple measurements of Doppler velocity. Main hurdle to obtaining multiple measurements is the time required to manually trace a series of Doppler traces. To make it easier to analyse more beats, we present an automated system for Doppler envelope quantification. It analyses long Doppler strips, spanning many heartbeats, and does not require the electrocardiogram to isolate individual beats. We tested its measurement of velocity-time-integral and peak-velocity against the reference standard defined as the average of three experts who each made three separate measurements. The automated measurements of velocity-time-integral showed strong correspondence (R2 = 0.94) and good Bland-Altman agreement (SD = 6.92%) with the reference consensus expert values, and indeed performed as well as the individual experts (R2 = 0.90 to 0.96, SD = 5.66% to 7.64%). The same performance was observed for peak-velocities; (R2 = 0.98, SD = 2.95%) and (R2 = 0.93 to 0.98, SD = 2.94% to 5.12%). This automated technology allows <10 times as many beats to be acquired and analysed compared to the conventional manual approach, with each beat maintaining its accuracy.

Immunosuppressive therapy reduces axonal damage in progressive multiple sclerosis.

PubMed

Axelsson, Markus; Malmeström, Clas; Gunnarsson, Martin; Zetterberg, Henrik; Sundström, Peter; Lycke, Jan; Svenningsson, Anders

2014-01-01

In progressive multiple sclerosis (PMS), disease-modifying therapies have not been shown to reduce disability progression. The impact from immunosuppressive therapy in PMS was explored by analyzing cerebrospinal fluid (CSF) biomarkers of axonal damage (neurofilament light protein, NFL), astrogliosis (glial fibrillary acidic protein, GFAP), and B-cell regulation (CXCL13). CSF was obtained from 35 patients with PMS before and after 12-24 months of mitoxantrone (n=30) or rituximab (n=5) treatment, and from 14 age-matched healthy control subjects. The levels of NFL, GFAP, and CXCL13 were determined by immunoassays. The mean NFL level decreased by 51% (1781 ng/l, SD 2018 vs. 874 ng/l, SD 694, p=0.007), the mean CXCL13 reduction was 55% (9.71 pg/ml, SD 16.08, vs. 4.37 pg/ml, SD 1.94, p=0.008), while GFAP levels remained unaffected. Subgroup analysis showed that the NFL reduction was confined to previously untreated patients (n=20) and patients with Gd-enhancing lesions on magnetic resonance imaging (n=12) prior to study baseline. Our data imply that 12-24 months of immunosuppressive therapy reduces axonal damage in PMS, particularly in patients with ongoing disease activity. Determination of NFL levels in CSF is a potential surrogate marker for treatment efficacy and as endpoint in phase II trials of MS.

Wavelength dependence and multiple-induced states in photoresponses of copper phthalocyanine-doped gold nanoparticle single-electron device

NASA Astrophysics Data System (ADS)

Yamamoto, Makoto; Ueda, Rieko; Terui, Toshifumi; Imazu, Keisuke; Tamada, Kaoru; Sakano, Takeshi; Matsuda, Kenji; Ishii, Hisao; Noguchi, Yutaka

2014-01-01

We have proposed a gold nanoparticle (GNP)-based single-electron transistor (SET) doped with a dye molecule, where the molecule works as a photoresponsive floating gate. Here, we examined the source-drain current (I_{\\text{SD}}) at a constant drain voltage under light irradiation with various wavelengths ranging from 400 to 700 nm. Current change was enhanced at the wavelengths of 600 and 700 nm, corresponding to the optical absorption band of the doped molecule (copper phthalocyanine: CuPc). Moreover, several peaks appear in the histograms of I_{\\text{SD}} during light irradiation, indicating that multiple discrete states were induced in the device. The results suggest that the current change was initiated by the light absorption of CuPc and multiple CuPc molecules near the GNP working as a floating gate. Molecular doping can activate advanced device functions in GNP-based SETs.

Investigation of cables for ionization chambers.

PubMed

Spokas, J J; Meeker, R D

1980-01-01

Seven coaxial cables which are in use for carrying currents generated in ionization chambers have been critically studied with reference to their suitability to this application. Included in this study are four low-noise triaxial cables and three low-noise two-conductor cables. For each cable the following characteristics were considered: inherent noise currents, currents produced by cable movements, polarization currents, the degree of electrostatic shielding of the central signal-carrying conductor, and radiation-induced cable currents. The study indicated that of the seven cables, two low-noise triaxial cables, both employing solid Teflon dielectric surrounding the central conductor, appear to offer the best overall performance for use with ionization chambers.

Photometric geodesy of main-belt asteroids. IV - An updated analysis of lightcurves for poles, periods, and shapes

NASA Technical Reports Server (NTRS)

Drummond, J. D.; Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R.

1991-01-01

The Drummond et al. (1988) analysis of main-belt asteroids is presently extended, using three independent methods to derive poles, periods, phase functions, and triaxial ellipsoid shapes from lightcurve maxima and minima. This group of 26 asteroids is also reinvestigated with a view to the distributions of triaxial shapes and obliquity distributions. Poles weakly tend to avoid asteroid orbital planes; a rough-smooth dichotomization appears to be justified by the persistence of two solar phase angle-amplitude relations. Seven of the objects may be Jacobi ellipsoids if axial ratios are slightly exaggerated by a systematic effect of the analytical method employed.

Poisson equations of rotational motion for a rigid triaxial body with application to a tumbling artificial satellite

NASA Technical Reports Server (NTRS)

Liu, J. J. F.; Fitzpatrick, P. M.

1975-01-01

A mathematical model is developed for studying the effects of gravity gradient torque on the attitude stability of a tumbling triaxial rigid satellite. Poisson equations are used to investigate the rotation of the satellite (which is in elliptical orbit about an attracting point mass) about its center of mass. An averaging method is employed to obtain an intermediate set of differential equations for the nonresonant, secular behavior of the osculating elements which describe the rotational motions of the satellite, and the averaged equations are then integrated to obtain long-term secular solutions for the osculating elements.

Characteristics of ground motion at permafrost sites along the Qinghai-Tibet railway

USGS Publications Warehouse

Wang, L.; Wu, Z.; Sun, Jielun; Liu, Xiuying; Wang, Z.

2009-01-01

Based on 14 typical drilling holes distributed in the permafrost areas along the Qinghai-Tibet railway, the distribution of wave velocities of soils in the permafrost regions were determined. Using results of dynamic triaxial tests, the results of dynamic triaxiality test and time histories of ground motion acceleration in this area, characteristics of ground motion response were analyzed for these permafrost sites for time histories of ground accelerations with three exceedance probabilities (63%, 10% and 2%). The influence of ground temperature on the seismic displacement, velocity, acceleration and response spectrum on the surface of permafrost were also studied. ?? 2008 Elsevier Ltd. All rights reserved.

Principal Components Analysis of Triaxial Vibration Data From Helicopter Transmissions

NASA Technical Reports Server (NTRS)

Tumer, Irem Y.; Huff, Edward M.

2001-01-01

Research on the nature of the vibration data collected from helicopter transmissions during flight experiments has led to several crucial observations believed to be responsible for the high rates of false alarms and missed detections in aircraft vibration monitoring systems. This work focuses on one such finding, namely, the need to consider additional sources of information about system vibrations. In this light, helicopter transmission vibration data, collected using triaxial accelerometers, were explored in three different directions, analyzed for content, and then combined using Principal Components Analysis (PCA) to analyze changes in directionality. In this paper, the PCA transformation is applied to 176 test conditions/data sets collected from an OH58C helicopter to derive the overall experiment-wide covariance matrix and its principal eigenvectors. The experiment-wide eigenvectors. are then projected onto the individual test conditions to evaluate changes and similarities in their directionality based on the various experimental factors. The paper will present the foundations of the proposed approach, addressing the question of whether experiment-wide eigenvectors accurately model the vibration modes in individual test conditions. The results will further determine the value of using directionality and triaxial accelerometers for vibration monitoring and anomaly detection.

Equidistant map projections of a triaxial ellipsoid with the use of reduced coordinates

NASA Astrophysics Data System (ADS)

Pędzich, Paweł

2017-12-01

The paper presents a new method of constructing equidistant map projections of a triaxial ellipsoid as a function of reduced coordinates. Equations for x and y coordinates are expressed with the use of the normal elliptic integral of the second kind and Jacobian elliptic functions. This solution allows to use common known and widely described in literature methods of solving such integrals and functions. The main advantage of this method is the fact that the calculations of x and y coordinates are practically based on a single algorithm that is required to solve the elliptic integral of the second kind. Equations are provided for three types of map projections: cylindrical, azimuthal and pseudocylindrical. These types of projections are often used in planetary cartography for presentation of entire and polar regions of extraterrestrial objects. The paper also contains equations for the calculation of the length of a meridian and a parallel of a triaxial ellipsoid in reduced coordinates. Moreover, graticules of three coordinates systems (planetographic, planetocentric and reduced) in developed map projections are presented. The basic properties of developed map projections are also described. The obtained map projections may be applied in planetary cartography in order to create maps of extraterrestrial objects.

On plastic flow in notched hexagonal close packed single crystals

NASA Astrophysics Data System (ADS)

Selvarajou, Balaji; Kondori, Babak; Benzerga, A. Amine; Joshi, Shailendra P.

2016-09-01

The micromechanics of anisotropic plastic flow by combined slip and twinning is investigated computationally in single crystal notched specimens. Constitutive relations for hexagonal close packed materials are used which take into account elastic anisotropy, thirty potential deformation systems, various hardening mechanisms and rate-sensitivity. The specimens are loaded perpendicular to the c-axis but the presence of a notch generates three-dimensional triaxial stress states. The study is motivated by recent experiments on a polycrystalline magnesium alloy. To enable comparisons with these where appropriate, three sets of activation thresholds for the various deformation systems are used. For the conditions that most closely mimic the alloy material, attention is focused on the relative roles of pyramidal 〈 c + a 〉 and prismatic 〈 a 〉 slip, as well as on the emergence of {1012bar}[101bar1] extension twinning at sufficiently high triaxiality. In all cases, the spatial variations of stress triaxiality and plastic strain, inclusive of various system activities, are quantified along with their evolution upon straining. The implications of these findings in fundamental understanding of ductile failure of HCP alloys in general and Mg alloys in particular are discussed.

Mechanical properties of triaxially braided composites: Experimental and analytical results

NASA Technical Reports Server (NTRS)

Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.

1992-01-01

This paper investigates the unnotched tensile properties of two-dimensional triaxial braid reinforced composites from both an experimental and analytical viewpoint. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer readings. Larger strain gages gave more consistent results and correlated better with the extensometer readings. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, zero degree, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistence of computer analysis of the microgeometry. Photomicrographs of the braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.

An exact solution for orbit view-periods from a station on a tri-axial ellipsoidal planet

NASA Technical Reports Server (NTRS)

Tang, C. C. H.

1986-01-01

This paper presents the concise exact solution for predicting view-periods to be observed from a masked or unmasked tracking station on a tri-axial ellipsoidal surface. The new exact approach expresses the azimuth and elevation angles of a spacecraft in terms of the station-centered geodetic topocentric coordinates in an elegantly concise manner. A simple and efficient algorithm is developed to avoid costly repetitive computations in searching for neighborhoods near the rise and set times of each satellite orbit for each station. Only one search for each orbit is necessary for each station. Sample results indicate that the use of an assumed spherical earth instead of an 'actual' tri-axial ellipsoidal earth could introduce an error up to a few minutes in a view-period prediction for circular orbits of low or medium altitude. For an elliptical orbit of high eccentricity and long period, the maximum error could be even larger. The analytic treatment and the efficient algorithm are designed for geocentric orbits, but they should be applicable to interplanetary trajectories by an appropriate coordinates transformation at each view-period calculation. This analysis can be accomplished only by not using the classical orbital elements.

Statistical Characterization of the Mechanical Parameters of Intact Rock Under Triaxial Compression: An Experimental Proof of the Jinping Marble

NASA Astrophysics Data System (ADS)

Jiang, Quan; Zhong, Shan; Cui, Jie; Feng, Xia-Ting; Song, Leibo

2016-12-01

We investigated the statistical characteristics and probability distribution of the mechanical parameters of natural rock using triaxial compression tests. Twenty cores of Jinping marble were tested under each different levels of confining stress (i.e., 5, 10, 20, 30, and 40 MPa). From these full stress-strain data, we summarized the numerical characteristics and determined the probability distribution form of several important mechanical parameters, including deformational parameters, characteristic strength, characteristic strains, and failure angle. The statistical proofs relating to the mechanical parameters of rock presented new information about the marble's probabilistic distribution characteristics. The normal and log-normal distributions were appropriate for describing random strengths of rock; the coefficients of variation of the peak strengths had no relationship to the confining stress; the only acceptable random distribution for both Young's elastic modulus and Poisson's ratio was the log-normal function; and the cohesive strength had a different probability distribution pattern than the frictional angle. The triaxial tests and statistical analysis also provided experimental evidence for deciding the minimum reliable number of experimental sample and for picking appropriate parameter distributions to use in reliability calculations for rock engineering.

Mechanical properties of triaxially braided composites: Experimental and analytical results

NASA Technical Reports Server (NTRS)

Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.

1992-01-01

The unnotched tensile properties of 2-D triaxial braid reinforced composites from both an experimental and an analytical viewpoint are studied. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer reading. Larger strain gages gave more consistent results and correlated better with the extensometer reading. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, 0 degrees, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistance of computer analysis of the microgeometry. Photomicrographs of braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.

An exact solution for orbit view-periods from a station on a tri-axial ellipsoidal planet

NASA Astrophysics Data System (ADS)

Tang, C. C. H.

1986-08-01

This paper presents the concise exact solution for predicting view-periods to be observed from a masked or unmasked tracking station on a tri-axial ellipsoidal surface. The new exact approach expresses the azimuth and elevation angles of a spacecraft in terms of the station-centered geodetic topocentric coordinates in an elegantly concise manner. A simple and efficient algorithm is developed to avoid costly repetitive computations in searching for neighborhoods near the rise and set times of each satellite orbit for each station. Only one search for each orbit is necessary for each station. Sample results indicate that the use of an assumed spherical earth instead of an 'actual' tri-axial ellipsoidal earth could introduce an error up to a few minutes in a view-period prediction for circular orbits of low or medium altitude. For an elliptical orbit of high eccentricity and long period, the maximum error could be even larger. The analytic treatment and the efficient algorithm are designed for geocentric orbits, but they should be applicable to interplanetary trajectories by an appropriate coordinates transformation at each view-period calculation. This analysis can be accomplished only by not using the classical orbital elements.

Modification of a Macromechanical Finite-Element Based Model for Impact Analysis of Triaxially-Braided Composites

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Blinzler, Brina J.; Binienda, Wieslaw K.

2010-01-01

A macro level finite element-based model has been developed to simulate the mechanical and impact response of triaxially-braided polymer matrix composites. In the analytical model, the triaxial braid architecture is simulated by using four parallel shell elements, each of which is modeled as a laminated composite. For the current analytical approach, each shell element is considered to be a smeared homogeneous material. The commercial transient dynamic finite element code LS-DYNA is used to conduct the simulations, and a continuum damage mechanics model internal to LS-DYNA is used as the material constitutive model. The constitutive model requires stiffness and strength properties of an equivalent unidirectional composite. Simplified micromechanics methods are used to determine the equivalent stiffness properties, and results from coupon level tests on the braided composite are utilized to back out the required strength properties. Simulations of quasi-static coupon tests of several representative braided composites are conducted to demonstrate the correlation of the model. Impact simulations of a represented braided composites are conducted to demonstrate the capability of the model to predict the penetration velocity and damage patterns obtained experimentally.

Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

NASA Technical Reports Server (NTRS)

Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

2009-01-01

The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

Concurrent Drought Stress and Vascular Pathogen Infection Induce Common and Distinct Transcriptomic Responses in Chickpea

PubMed Central

Sinha, Ranjita; Gupta, Aarti; Senthil-Kumar, Muthappa

2017-01-01

Chickpea (Cicer arietinum); the second largest legume grown worldwide is prone to drought and various pathogen infections. These drought and pathogen stresses often occur concurrently in the field conditions. However, the molecular events in response to that are largely unknown. The present study examines the transcriptome dynamics in chickpea plants exposed to a combination of water-deficit stress and Ralstonia solanacearum infection. R. solanacearum is a potential wilt disease causing pathogen in chickpea. Drought stressed chickpea plants were infected with this pathogen and the plants were allowed to experience progressive drought with 2 and 4 days of R. solanacearum infection called short duration stress (SD stresses) and long duration stress (LD stresses), respectively. Our study showed that R. solanacearum multiplication decreased under SD-combined stress compared to SD-pathogen but there was no significant change in LD-combined stress compared to LD-pathogen. The microarray analysis during these conditions showed that 821 and 1039 differentially expressed genes (DEGs) were unique to SD- and LD-combined stresses, respectively, when compared with individual stress conditions. Three and fifteen genes were common among all the SD-stress treatments and LD-stress treatments, respectively. Genes involved in secondary cell wall biosynthesis, alkaloid biosynthesis, defense related proteins, and osmo-protectants were up-regulated during combined stress. The expression of genes involved in lignin and cellulose biosynthesis were specifically up-regulated in SD-combined, LD-combined, and LD-pathogen stress. A close transcriptomic association of LD-pathogen stress with SD-combined stress was observed in this study which indicates that R. solanacearum infection also exerts drought stress along with pathogen stress thus mimics combined stress effect. Furthermore the expression profiling of candidate genes using real-time quantitative PCR validated the microarray data. The study showed that down-regulation of defense-related genes during LD-combined stress resulted in an increased bacterial multiplication as compared to SD-combined stress. Overall, our study highlights a sub-set of DEGs uniquely expressed in response to combined stress, which serve as potential candidates for further functional characterization to delineate the molecular response of the plant to concurrent drought-pathogen stress. PMID:28382041

Inflammatory Papillitis in Uveitis: Response to Treatment and Use of Optic Nerve Optical Coherence Tomography for Monitoring.

PubMed

Cho, Heeyoon; Pillai, Parvathy; Nicholson, Laura; Sobrin, Lucia

2016-01-01

To describe the clinical course of uveitis-associated inflammatory papillitis and evaluate the utility and reproducibility of optic nerve spectral domain optical coherence tomography (SD-OCT). Data on 22 eyes of 14 patients with uveitis-related papillitis and optic nerve imaging were reviewed. SD-OCT measure reproducibility was determined and parameters were compared in active vs. inactive uveitis. Papillitis resolution lagged behind uveitis resolution in three patients. For SD-OCT measures, the intraclass correlation coefficients were 99.1-100% and 86.9-100% for intraobserver and interobserver reproducibility, respectively. All SD-OCT optic nerve measures except inferior and nasal peripapillary retinal thicknesses were significantly higher in active vs. inactive uveitis after correction for multiple hypotheses testing. Mean optic nerve central thickness decreased from 545.1 to 362.9 µm (p = 0.01). Resolution of inflammatory papillitis can lag behind resolution of uveitis. SD-OCT assessment of papillitis is reproducible and correlates with presence vs. resolution of uveitis.

Parameter studies of sediments in the Storegga Slide region

NASA Astrophysics Data System (ADS)

Yang, S. L.; Kvalstad, T.; Solheim, A.; Forsberg, C. F.

2006-09-01

Based on classification tests, oedometer tests, fall-cone tests and triaxial tests, physical and mechanical properties of sediments in the Storegga Slide region were analysed to assess parameter interrelationships. The data show good relationships between a number of physical and mechanical parameters. Goodness of fit between compression index and various physical parameters can be improved by multiple regression analysis. The interclay void ratio and liquidity index correlate well with the undrained shear strength of clay. Sediments with higher water content, liquid limit, activity, interclay void ratio, plasticity index and liquidity index showed higher compression index and/or lower undrained shear strength. Some relationships between parameters were tested by using data from two other sites south of the Storegga Slide. A better understanding of properties of sediments in regions such as that of the Storegga Slide can be obtained through this approach.

A combined inspiratory and expiratory muscle training program improves respiratory muscle strength and fatigue in multiple sclerosis.

PubMed

Ray, Andrew D; Udhoji, Supriya; Mashtare, Terry L; Fisher, Nadine M

2013-10-01

To determine the effects of a short-duration, combined (inspiratory and expiratory), progressive resistance respiratory muscle training (RMT) protocol on respiratory muscle strength, fatigue, health-related quality of life, and functional performance in individuals with mild-to-moderate multiple sclerosis (MS). Quasi-experimental before-after trial. University rehabilitation research laboratory. Volunteers with MS (N=21) were divided into 2 groups: RMT (n=11; 9 women, 2 men; mean age ± SD, 50.9 ± 5.7y, mean Expanded Disability Status Scale score ± SD, 3.2 ± 1.9) and a control group that did not train (n=10; 7 women, 3 men; mean age ± SD, 56.2 ± 8.8y, mean Expanded Disability Status Scale score ± SD, 4.4 ± 2.1). Expanded Disability Status Scale scores ranged from 1 to ≤6.5. No patients withdrew from the study. Training was a 5-week combined progressive resistance RMT program, 3d/wk, 30 minutes per session. The primary outcome measures were maximal inspiratory pressure and expiratory pressure and the Modified Fatigue Impact Scale. All subjects completed secondary measures of pulmonary function, the six-minute walk test, the timed stair climb, the Multiple Sclerosis Self-Efficacy Scale, the Medical Outcomes Study 36-Item Short-Form Health Survey, and the Physical Activity Disability Scale. Maximal inspiratory pressure and expiratory pressure (mean ± SD) increased 35% ± 22% (P<.001) and 26% ± 17% (P<.001), respectively, whereas no changes were noted in the control group (12% ± 23% and -4% ± 17%, respectively). RMT improved fatigue (Modified Fatigue Impact Scale, P<.029), with no change or worsening in the control group. No changes were noted in the six-minute walk test, stair climb, Multiple Sclerosis Self-Efficacy Scale, or Physical Activity Disability Scale in the RMT group. The control group had decreases in emotional well-being and general health (Medical Outcomes Study 36-Item Short-Form Health Survey). A short-duration, combined RMT program improved inspiratory and expiratory muscle strength and reduced fatigue in patients with mild to moderate MS. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Black Hole in the Most Massive Ultracompact Dwarf Galaxy M59-UCD3

NASA Astrophysics Data System (ADS)

Ahn, Christopher P.; Seth, Anil C.; Cappellari, Michele; Krajnović, Davor; Strader, Jay; Voggel, Karina T.; Walsh, Jonelle L.; Bahramian, Arash; Baumgardt, Holger; Brodie, Jean; Chilingarian, Igor; Chomiuk, Laura; den Brok, Mark; Frank, Matthias; Hilker, Michael; McDermid, Richard M.; Mieske, Steffen; Neumayer, Nadine; Nguyen, Dieu D.; Pechetti, Renuka; Romanowsky, Aaron J.; Spitler, Lee

2018-05-01

We examine the internal properties of the most massive ultracompact dwarf galaxy (UCD), M59-UCD3, by combining adaptive-optics-assisted near-IR integral field spectroscopy from Gemini/NIFS and Hubble Space Telescope (HST) imaging. We use the multiband HST imaging to create a mass model that suggests and accounts for the presence of multiple stellar populations and structural components. We combine these mass models with kinematics measurements from Gemini/NIFS to find a best-fit stellar mass-to-light ratio (M/L) and black hole (BH) mass using Jeans anisotropic models (JAMs), axisymmetric Schwarzschild models, and triaxial Schwarzschild models. The best-fit parameters in the JAM and axisymmetric Schwarzschild models have BHs between 2.5 and 5.9 million solar masses. The triaxial Schwarzschild models point toward a similar BH mass but show a minimum χ 2 at a BH mass of ∼0. Models with a BH in all three techniques provide better fits to the central V rms profiles, and thus we estimate the BH mass to be {4.2}-1.7+2.1× {10}6 M ⊙ (estimated 1σ uncertainties). We also present deep radio imaging of M59-UCD3 and two other UCDs in Virgo with dynamical BH mass measurements, and we compare these to X-ray measurements to check for consistency with the fundamental plane of BH accretion. We detect faint radio emission in M59cO but find only upper limits for M60-UCD1 and M59-UCD3 despite X-ray detections in both these sources. The BH mass and nuclear light profile of M59-UCD3 suggest that it is the tidally stripped remnant of a ∼109–1010 M ⊙ galaxy.

Effect of Sleep Deprivation on the Male Reproductive System in Rats.

PubMed

Choi, Ji Ho; Lee, Seung Hoon; Bae, Jae Hyun; Shim, Ji Sung; Park, Hong Seok; Kim, Young Sik; Shin, Chol

2016-10-01

There has been no study reporting on the influence of sleep deprivation on the male reproductive system including sperm quality. In this study, we hypothesized that sleep deprivation could lead to adverse effect on the male reproductive system. The rats were divided into three groups: 1) control (home-cage, n = 10); 2) SD4 (sleep deprivation for 4 days, n = 10); and 3) SD7 (sleep deprivation for 7 days, n = 10). Sleep deprivation was performed by a modified multiple platform method. Sperm quality (sperm motion parameters and counts), hormone levels (corticosterone and testosterone), and the histopathology of testis were evaluated and compared between the three groups. A statistically significant reduction (P = 0.018) was observed in sperm motility in the SD7 group compared to those of the control group. However, there were no significant differences in other sperm motion parameters, or in sperm counts of the testis and cauda epididymis between three groups. Compared with the control group, the SD4 (P = 0.033) and SD7 (P = 0.002) groups exhibited significant increases of corticosterone levels, but significant decreases of testosterone levels were found in the SD4 (P = 0.001) and SD7 (P < 0.001) groups. Seminiferous tubular atrophy and/or spermatid retention was partially observed in the SD4 and SD7 groups, compared with the normal histopathology of the control group. Sleep deprivation may have an adverse effect on the male reproductive system in rats.

Blockface histology with optical coherence tomography: a comparison with Nissl staining.

PubMed

Magnain, Caroline; Augustinack, Jean C; Reuter, Martin; Wachinger, Christian; Frosch, Matthew P; Ragan, Timothy; Akkin, Taner; Wedeen, Van J; Boas, David A; Fischl, Bruce

2014-01-01

Spectral domain optical coherence tomography (SD-OCT) is a high resolution imaging technique that generates excellent contrast based on intrinsic optical properties of the tissue, such as neurons and fibers. The SD-OCT data acquisition is performed directly on the tissue block, diminishing the need for cutting, mounting and staining. We utilized SD-OCT to visualize the laminar structure of the isocortex and compared cortical cytoarchitecture with the gold standard Nissl staining, both qualitatively and quantitatively. In histological processing, distortions routinely affect registration to the blockface image and prevent accurate 3D reconstruction of regions of tissue. We compared blockface registration to SD-OCT and Nissl, respectively, and found that SD-OCT-blockface registration was significantly more accurate than Nissl-blockface registration. Two independent observers manually labeled cortical laminae (e.g. III, IV and V) in SD-OCT images and Nissl stained sections. Our results show that OCT images exhibit sufficient contrast in the cortex to reliably differentiate the cortical layers. Furthermore, the modalities were compared with regard to cortical laminar organization and showed good agreement. Taken together, these SD-OCT results suggest that SD-OCT contains information comparable to standard histological stains such as Nissl in terms of distinguishing cortical layers and architectonic areas. Given these data, we propose that SD-OCT can be used to reliably generate 3D reconstructions of multiple cubic centimeters of cortex that can be used to accurately and semi-automatically perform standard histological analyses. © 2013.

Blockface Histology with Optical Coherence Tomography: A Comparison with Nissl Staining

PubMed Central

Magnain, Caroline; Augustinack, Jean C.; Reuter, Martin; Wachinger, Christian; Frosch, Matthew P.; Ragan, Timothy; Akkin, Taner; Wedeen, Van J.; Boas, David A.; Fischl, Bruce

2015-01-01

Spectral domain optical coherence tomography (SD-OCT) is a high resolution imaging technique that generates excellent contrast based on intrinsic optical properties of the tissue, such as neurons and fibers. The SD-OCT data acquisition is performed directly on the tissue block, diminishing the need for cutting, mounting and staining. We utilized SD-OCT to visualize the laminar structure of the isocortex and compared cortical cytoarchitecture with the gold standard Nissl staining, both qualitatively and quantitatively. In histological processing, distortions routinely affect registration to the blockface image and prevent accurate 3D reconstruction of regions of tissue. We compared blockface registration to SD-OCT and Nissl, respectively, and found that SD-OCT-blockface registration was significantly more accurate than Nissl-blockface registration. Two independent observers manually labeled cortical laminae (e.g. III, IV and V) in SD-OCT images and Nissl stained sections. Our results show that OCT images exhibit sufficient contrast in the cortex to reliably differentiate the cortical layers. Furthermore, the modalities were compared with regard to cortical laminar organization and showed good agreement. Taken together, these SD-OCT results suggest that SD-OCT contains information comparable to standard histological stains such as Nissl in terms of distinguishing cortical layers and architectonic areas. Given these data, we propose that SD-OCT can be used to reliably generate 3D reconstructions of multiple cubic centimeters of cortex that can be used to accurately and semi-automatically perform standard histological analyses. PMID:24041872

[Ten years of emergency attendances for cocaine-users in Spain].

PubMed

Galicia, Miguel; Nogué, Santiago; Burillo-Putze, Guillermo

2014-10-07

Cocaine is the second most consumed illegal drug in the western world, following cannabis. Since 1998, it is also the drug that more attendances generate in different emergency devices, and it is responsible for more of 60% of the emergencies directly related to drug consumption. This work reviews the main Spanish scientific articles published in the last 10 years, in which different factors related to the use of this drug have been analyzed in relation to the use of emergency by cocaine users. A total of 8,795 patients were included (interval 57-1,755), with an average age of 32.64 years (SD 3.02), and an average percentage of positives to cocaine of 54.78% (SD 47.03); there were 7 works with 100% of subjects being positive to cocaine. Males predominated with an average of 78.69% (SD 12). They presented cardiovascular symptoms in 30% cases (SD 22.7), neurological symptoms in 11.6% cases (SD 4.28) and psychiatric symptoms in 49.32% cases (SD 23.87). There was a multiple consumption in 49.02% of patients (interval 4.3-76.2), fundamentally associated with alcohol (57.78%, SD 6.18) and cannabis (21.56%, SD 10.72). Two hundred and forty-six patients (2.8%) needed admission and 8 died (0.09%). Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Explicit memory performance in infants of diabetic mothers at 1 year of age.

PubMed

DeBoer, Tracy; Wewerka, Sandi; Bauer, Patricia J; Georgieff, Michael K; Nelson, Charles A

2005-08-01

The aim of the present research was to investigate the impact of abnormal fetal environment on explicit memory performance. Based on animal models, it was hypothesized that infants of diabetic mothers (IDMs) experience perturbations in memory performance due to exposure to multiple neurologic risk factors including: chronic hypoxia, hyperglycemia/reactive hypoglycemia, and iron deficiency. Memory performance, as measured by the elicited/deferred imitation paradigm, was compared between 13 IDMs (seven females, six males; mean age 365 days, SD 11) and 16 typically developing children (seven females, nine males; mean age 379 days, SD 9). The IDM group was characterized by shorter gestational age (mean 38w, SD 2), greater standardized birthweight scores (mean 3797g, SD 947), and lower iron stores (mean ferritin concentration 87C microg/L, SD 68) in comparison with the control group (mean gestational age: 40w, SD 1; mean birthweight: 3639g, SD 348; mean newborn ferritin concentration 140 microg/L, SD 46). After statistically controlling for both gestational age and global cognitive abilities, IDMs demonstrated a deficit in the ability to recall multi-step event sequences after a delay was imposed. These findings highlight the importance of the prenatal environment on subsequent mnemonic behavior and suggest a connection between metabolic abnormalities during the prenatal period, development of memory, circuitry, and behavioral mnemonic performance.

Explicit Memory Performance in Infants of Diabetic Mothers at 1 Year of Age

PubMed Central

DeBoer, Tracy; Wewerka, Sandi; Bauer, Patricia J.; Georgieff, Michael K.; Nelson, Charles A.

2010-01-01

The aim of the present research was to investigate the impact of abnormal fetal environment on explicit memory performance. Based on animal models, it was hypothesized that infants of diabetic mothers (IDMs) experience perturbations in memory performance due to exposure to multiple neurologic risk factors including: chronic hypoxia, hyperglycemia/reactive hypoglycemia, and iron deficiency. Memory performance, as measured by the elicited/deferred imitation paradigm, was compared between 13 IDMs (7 female, 6 male; mean age 365 days, SD 11) and 16 typically developing children (7 female, 9 male; mean age 379 days, SD 9). The IDM group was characterized by shorter gestational age (mean 38 weeks, SD 2), greater standardized birth weight scores (mean 3797 grams, SD 947), and lower iron stores (mean ferritin concentration 87 μg/L, SD 68) in comparison with the control group (mean gestational age: 40 weeks, SD 1; mean birth weight: 3639 grams, SD 348; mean newborn ferritin concentration 140 μg/L, SD 46). After statistically controlling for both gestational age and global cognitive abilities, IDMs demonstrated a deficit in the ability to recall multi-step event sequences when a delay was imposed. These findings underscore the importance of the prenatal environment on subsequent mnemonic behavior and suggest a connection between metabolic abnormalities during the prenatal period, development of memory circuitry, and behavioral mnemonic performance. PMID:16108452

π Berry phase and Zeeman splitting of Weyl semimetal TaP

DOE PAGES

Hu, J.; Liu, J. Y.; Graf, D.; ...

2016-01-04

Here, the recent breakthrough in the discovery of Weyl fermions in monopnictide semimetals provides opportunities to explore the exotic properties of relativistic fermions in condensed matter. The chiral anomaly-induced negative magnetoresistance and π Berry phase are two fundamental transport properties associated with the topological characteristics of Weyl semimetals. Since monopnictide semimetals are multiple-band systems, resolving clear Berry phase for each Fermi pocket remains a challenge. Here we report the determination of Berry phases of multiple Fermi pockets of Weyl semimetal TaP through high field quantum transport measurements. We show our TaP single crystal has the signatures of a Weyl state,more » including light effective quasiparticle masses, ultrahigh carrier mobility, as well as negative longitudinal magnetoresistance. Furthermore, we have generalized the Lifshitz-Kosevich formula for multiple-band Shubnikov-de Haas (SdH) oscillations and extracted the Berry phases of π for multiple Fermi pockets in TaP through the direct fits of the modified LK formula to the SdH oscillations. In high fields, we also probed signatures of Zeeman splitting, from which the Landé g-factor is extracted.« less

Sensitivity and specificity of detecting reticular pseudodrusen in multimodal imaging in Japanese patients.

PubMed

Ueda-Arakawa, Naoko; Ooto, Sotaro; Tsujikawa, Akitaka; Yamashiro, Kenji; Oishi, Akio; Yoshimura, Nagahisa

2013-03-01

To identify reticular pseudodrusen (RPD) in age-related macular degeneration using multiple imaging modalities, including the blue channel image of fundus photography, infrared reflectance (IR), fundus autofluorescence, near-infrared fundus autofluorescence, confocal blue reflectance, indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT), and to compare the sensitivities and specificities of these modalities for detecting RPD. This study included 220 eyes from 114 patients with newly diagnosed age-related macular degeneration. Patients underwent fundus photography, IR, fundus autofluorescence, near-infrared fundus autofluorescence, confocal blue reflectance, indocyanine green angiography, and SD-OCT in both eyes. Eyes were diagnosed with RPD if they showed reticular patterns on at least two of the seven imaging modalities. Thirty-seven eyes were diagnosed with RPD. However, SD-OCT and IR had the highest sensitivity (94.6%), and at the same time, SD-OCT had a high specificity (98.4%). The blue channel of color fundus photography, confocal blue reflectance, and indocyanine green angiography had a specificity of 100% but had lower sensitivity than that of SD-OCT and IR. For detecting RPD, IR and SD-OCT had the highest sensitivity. Although SD-OCT had the highest sensitivity and specificity, RPD detection should be confirmed using more than one modality for increased accuracy.

Risk and protective factors for spasmodic dysphonia: a case-control investigation.

PubMed

Tanner, Kristine; Roy, Nelson; Merrill, Ray M; Kimber, Kamille; Sauder, Cara; Houtz, Daniel R; Doman, Darrin; Smith, Marshall E

2011-01-01

Spasmodic dysphonia (SD) is a chronic, incurable, and often disabling voice disorder of unknown pathogenesis. The purpose of this study was to identify possible endogenous and exogenous risk and protective factors uniquely associated with SD. Prospective, exploratory, case-control investigation. One hundred fifty patients with SD and 150 medical controls (MCs) were interviewed regarding their personal and family histories, environmental exposures, illnesses, injuries, voice use patterns, and general health using a previously vetted and validated epidemiologic questionnaire. Odds ratios and multiple logistic regression analyses (α<0.15) identified several factors that significantly increased the likelihood of having SD. These factors included (1) a personal history of mumps, blepharospasm, tremor, intense occupational and avocational voice use, and a family history of voice disorders; (2) an immediate family history of meningitis, tremor, tics, cancer, and compulsive behaviors; and (3) an extended family history of tremor and cancer. SD is likely multifactorial in etiology, involving both genetic and environmental factors. Viral infections/exposures, along with intense voice use, may trigger the onset of SD in genetically predisposed individuals. Future studies should examine the interaction among genetic and environmental factors to determine the pathogenesis of SD. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Miniature triaxial metastable ionization detector for gas chromatographic trace analysis of extraterrestrial volatiles

NASA Technical Reports Server (NTRS)

Woeller, F. H.; Kojiro, D. R.; Carle, G. C.

1984-01-01

The present investigation is concerned with a miniature metastable ionization detector featuring an unconventional electrode configuration, whose performance characteristics parallel those of traditional design. The ionization detector is to be incorporated in a flight gas chromatograph (GC) for use in the Space Shuttle. The design of the detector is discussed, taking into account studies which verified the sensitivity of the detector. The triaxial design of the detector is compared with a flat-plate style. The obtained results show that the principal goal of developing a miniature, highly sensitive ionization detector for flight applications was achieved. Improved fabrication techniques will utilize glass-to-metal seals and brazing procedures.

On the 3He anomaly in hot subdwarf B stars

NASA Astrophysics Data System (ADS)

Schneider, David; Irrgang, Andreas; Heber, Ulrich; Nieva, Maria F.; Przybilla, Norbert

2017-12-01

Decades ago, 3He isotope enrichment in helium-weak B-type main-sequence, in blue horizontal branch and in hot subdwarf B (sdB) stars, i.e., helium-core burning stars of the extreme horizontal branch, were discovered. Diffusion processes in the atmosphere of these stars lead to the observed abundance anomalies. Quantitative spectral analyses of high-resolution spectra to derive photospheric isotopic helium abundance ratios for known 3He sdBs have not been performed yet. We present preliminary results of high-resolution and high S/N spectra to determine the 3He and 4He abundances of nine known 3He sdBs. We used a hybrid local/non-local thermodynamic equilibrium (LTE/NLTE) approach for B-type stars investigating multiple He i lines, including λ4922 Å and λ6678 Å, which show the strongest isotopic shifts in the optical spectral range.We also report the discovery of four new 3He sdBs from the ESO Supernova Progenitor survey. Most of the 3He sdBs cluster in a narrow temperature strip between ˜ 26000 K and ˜ 30000 K and have almost no atmospheric 4He at all. Interestingly, three 3He sdBs show evidence for vertical helium stratification.

Leveraging genome-wide datasets to quantify the functional role of the anti-Shine-Dalgarno sequence in regulating translation efficiency.

PubMed

Hockenberry, Adam J; Pah, Adam R; Jewett, Michael C; Amaral, Luís A N

2017-01-01

Studies dating back to the 1970s established that sequence complementarity between the anti-Shine-Dalgarno (aSD) sequence on prokaryotic ribosomes and the 5' untranslated region of mRNAs helps to facilitate translation initiation. The optimal location of aSD sequence binding relative to the start codon, the full extents of the aSD sequence and the functional form of the relationship between aSD sequence complementarity and translation efficiency have not been fully resolved. Here, we investigate these relationships by leveraging the sequence diversity of endogenous genes and recently available genome-wide estimates of translation efficiency. We show that-after accounting for predicted mRNA structure-aSD sequence complementarity increases the translation of endogenous mRNAs by roughly 50%. Further, we observe that this relationship is nonlinear, with translation efficiency maximized for mRNAs with intermediate levels of aSD sequence complementarity. The mechanistic insights that we observe are highly robust: we find nearly identical results in multiple datasets spanning three distantly related bacteria. Further, we verify our main conclusions by re-analysing a controlled experimental dataset. © 2017 The Authors.

Brachial plexus palsy and shoulder dystocia: obstetric risk factors remain elusive.

PubMed

Ouzounian, Joseph G; Korst, Lisa M; Miller, David A; Lee, Richard H

2013-04-01

Shoulder dystocia (SD) and brachial plexus palsy (BPP) are complications of childbirth that can result in significant long-term sequelae. The purpose of the present study was to analyze risk factors in cases of SD and BPP. We performed a retrospective study of laboring women who delivered a singleton, term, live-born infant at the Los Angeles County + University of Southern California Medical Center from 1995 to 2004. Multivariable logistic regression models were used to analyze risk factors among SD cases with and without BPP. Of the 13,998 deliveries that met inclusion criteria, 221 (1.6%) had SD. Of these, 42 (19.0%) had BPP. After testing for association with multiple potential risk factors, including maternal demographic variables, diabetes, hypertension, prior cesarean delivery, uterine abnormalities, induction of labor, prolonged second stage (adjusted by parity and epidural use), assisted vaginal delivery, and neonatal birth weight, no statistical association of BPP with any specific risk factor was identified. In the present study, we were unable to identify any reliable risk factors for BPP among deliveries with or without SD. SD and BPP remain unpredictable complications of childbirth. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Still's Disease in a Pediatric Patient after Liver Transplantation.

PubMed

Meza, Juan-Carlos; Muñoz-Buitrón, Evelyn; Bonilla-Abadía, Fabio; Cañas, Carlos Alberto; Tobón, Gabriel J

2013-01-01

Still's disease (SD) is a multisystemic inflammatory disease characterized by persistent arthritis and in many cases with fever of unknown origin. Diagnosis of SD is challenging because of nonspecific characteristics and especially in the case of a patient with solid organ transplantation and immunosuppressive therapy where multiple causes of fever are possible. There is no diagnostic test for SD, even though some useful diagnostic criteria or laboratory findings, such as serum ferritin levels, have been proposed, and useful imaging studies for the diagnosis or followup of SD have not been developed. We report the case of a 9-year-old child who presented with high grade fever associated with joint pain after a history of liver transplantation and immunosuppressive therapy. Laboratory tests showed increased acute phase reactants, elevated ferritin, and leukocytosis. An 18 F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) was performed identifying abnormal hypermetabolic areas localized in spleen, transplanted liver, and bone marrow secondary to inflammatory process. All infectious, autoimmune, and malignant causes were ruled out. A diagnosis of SD was performed and a steroid-based regimen was initiated with adequate response and no evidence of recurrence. To our knowledge this is the first case of SD following a solid organ transplant.

Hydrothermal deformation of granular quartz sand

NASA Astrophysics Data System (ADS)

Karner, Stephen L.; Kronenberg, Andreas K.; Chester, Frederick M.; Chester, Judith S.; Hajash, Andrew

2008-05-01

Isotropic and triaxial compression experiments were performed on porous aggregates of St Peter quartz sand to explore the influence of temperature (to 225°C). During isotropic stressing, samples loaded at elevated temperature exhibit the same sigmoidal stress-strain curves and non-linear acoustic emission rates as have previously been observed from room temperature studies on sands, sandstones, and soils. However, results from our hydrothermal experiments show that the critical effective pressure (P*) associated with the onset of significant pore collapse and pervasive cataclastic flow is lower at increased temperature. Samples subjected to triaxial loading at elevated temperature show yield behavior resembling that observed from room temperature studies on granular rocks and soils. When considered in terms of distortional and mean stresses, the yield strength data for a given temperature define an elliptical envelope consistent with critical state and CAP models from soil mechanics. For the conditions we tested, triaxial yield data at low effective pressure are essentially temperature-insensitive whereas yield levels at high effective pressure are lowered as a function of elevated temperature. We interpret our yield data in a manner consistent with Arrhenius behavior expected for thermally assisted subcritical crack growth. Taken together, our results indicate that increased stresses and temperatures associated with subsurface burial will significantly alter the yield strength of deforming granular media in systematic and predictable ways.

Application of a tri-axial accelerometer to estimate jump frequency in volleyball.

PubMed

Jarning, Jon M; Mok, Kam-Ming; Hansen, Bjørge H; Bahr, Roald

2015-03-01

Patellar tendinopathy is prevalent among athletes, and most likely associated with a high jumping load. If methods for estimating jump frequency were available, this could potentially assist in understanding and preventing this condition. The objective of this study was to explore the possibility of using peak vertical acceleration (PVA) or peak resultant acceleration (PRA) measured by an accelerometer to estimate jump frequency. Twelve male elite volleyball players (22.5 ± 1.6 yrs) performed a training protocol consisting of seven typical motion patterns, including jumping and non-jumping movements. Accelerometer data from the trial were obtained using a tri-axial accelerometer. In addition, we collected video data from the trial. Jump-float serving and spike jumping could not be distinguished from non-jumping movements using differences in PVA or PRA. Furthermore, there were substantial inter-participant differences in both the PVA and the PRA within and across movement types (p < 0.05). These findings suggest that neither PVA nor PRA measured by a tri-axial accelerometer is an applicable method for estimating jump frequency in volleyball. A method for acquiring real-time estimates of jump frequency remains to be verified. However, there are several alternative approaches, and further investigations are needed.

Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach

NASA Technical Reports Server (NTRS)

Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.

2015-01-01

A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles of 0deg, 30deg, 45deg, 60deg and 90deg relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.

Experimental and Numerical Analysis of Triaxially Braided Composites Utilizing a Modified Subcell Modeling Approach

NASA Technical Reports Server (NTRS)

Cater, Christopher; Xiao, Xinran; Goldberg, Robert K.; Kohlman, Lee W.

2015-01-01

A combined experimental and analytical approach was performed for characterizing and modeling triaxially braided composites with a modified subcell modeling strategy. Tensile coupon tests were conducted on a [0deg/60deg/-60deg] braided composite at angles [0deg, 30deg, 45deg, 60deg and 90deg] relative to the axial tow of the braid. It was found that measured coupon strength varied significantly with the angle of the applied load and each coupon direction exhibited unique final failures. The subcell modeling approach implemented into the finite element software LS-DYNA was used to simulate the various tensile coupon test angles. The modeling approach was successful in predicting both the coupon strength and reported failure mode for the 0deg, 30deg and 60deg loading directions. The model over-predicted the strength in the 90deg direction; however, the experimental results show a strong influence of free edge effects on damage initiation and failure. In the absence of these local free edge effects, the subcell modeling approach showed promise as a viable and computationally efficient analysis tool for triaxially braided composite structures. Future work will focus on validation of the approach for predicting the impact response of the braided composite against flat panel impact tests.

Research on the deformation and failure evolution of sandstone under triaxial compression based on PFC2D

NASA Astrophysics Data System (ADS)

Yang, X. B.; Han, X. X.; Zhou, T. B.; Liu, E. L.

2017-04-01

Through the comparative analysis of the results of the triaxial compression experiments of sandstone and the numerical simulation results of particle flow code PFC2D under the same conditions, the typical simulation curve and the corresponding simulation process were selected to analyze the evolution characteristics of the surface deformation field, the evolution characteristics of the velocity field and displacement field of the deformation localization bands of sandstone under triaxial compression. Research results show that the changes of the velocities and displacements of deformation localization bands corresponds to the change of stress during compression; In the same deformation localization band, the dislocation velocities are always in the same direction, but in the direction vertical to the localization band, the localization band sometimes squeezes and sometimes stretches; At different positions of the same deformation localization band, the dislocation velocities and extrusion velocities are both different at the same time; In the post-peak stage of loading, along the same deformation localization band, the dislocation displacements close to both loaded ends are generally greater than the ones near to the middle position of the specimen, the stretching displacements close to both loaded ends are generally smaller than the ones near to the middle position of the specimen.

The doubling of stellar black hole nuclei

NASA Astrophysics Data System (ADS)

Kazandjian, Mher V.; Touma, J. R.

2013-04-01

It is strongly believed that Andromeda's double nucleus signals a disc of stars revolving around its central supermassive black hole on eccentric Keplerian orbits with nearly aligned apsides. A self-consistent stellar dynamical origin for such apparently long-lived alignment has so far been lacking, with indications that cluster self-gravity is capable of sustaining such lopsided configurations if and when stimulated by external perturbations. Here, we present results of N-body simulations which show unstable counter-rotating stellar clusters around supermassive black holes saturating into uniformly precessing lopsided nuclei. The double nucleus in our featured experiment decomposes naturally into a thick eccentric disc of apo-apse aligned stars which is embedded in a lighter triaxial cluster. The eccentric disc reproduces key features of Keplerian disc models of Andromeda's double nucleus; the triaxial cluster has a distinctive kinematic signature which is evident in Hubble Space Telescope observations of Andromeda's double nucleus, and has been difficult to reproduce with Keplerian discs alone. Our simulations demonstrate how the combination of an eccentric disc and a triaxial cluster arises naturally when a star cluster accreted over a preexisting and counter-rotating disc of stars drives disc and cluster into a mutually destabilizing dance. Such accretion events are inherent to standard galaxy formation scenarios. They are here shown to double stellar black hole nuclei as they feed them.

Orientational dynamics of a triaxial ellipsoid in simple shear flow: Influence of inertia.

PubMed

Rosén, Tomas; Kotsubo, Yusuke; Aidun, Cyrus K; Do-Quang, Minh; Lundell, Fredrik

2017-07-01

The motion of a single ellipsoidal particle in simple shear flow can provide valuable insights toward understanding suspension flows with nonspherical particles. Previously, extensive studies have been performed on the ellipsoidal particle with rotational symmetry, a so-called spheroid. The nearly prolate ellipsoid (one major and two minor axes of almost equal size) is known to perform quasiperiodic or even chaotic orbits in the absence of inertia. With small particle inertia, the particle is also known to drift toward this irregular motion. However, it is not previously understood what effects from fluid inertia could be, which is of highest importance for particles close to neutral buoyancy. Here, we find that fluid inertia is acting strongly to suppress the chaotic motion and only very weak fluid inertia is sufficient to stabilize a rotation around the middle axis. The mechanism responsible for this transition is believed to be centrifugal forces acting on fluid, which is dragged along with the rotational motion of the particle. With moderate fluid inertia, it is found that nearly prolate triaxial particles behave similarly to the perfectly spheroidal particles. Finally, we also are able to provide predictions about the stable rotational states for the general triaxial ellipsoid in simple shear with weak inertia.

An experimental platform for triaxial high-pressure/high-temperature testing of rocks using computed tomography

NASA Astrophysics Data System (ADS)

Glatz, Guenther; Lapene, Alexandre; Castanier, Louis M.; Kovscek, Anthony R.

2018-04-01

A conventional high-pressure/high-temperature experimental apparatus for combined geomechanical and flow-through testing of rocks is not X-ray compatible. Additionally, current X-ray transparent systems for computed tomography (CT) of cm-sized samples are limited to design temperatures below 180 °C. We describe a novel, high-temperature (>400 °C), high-pressure (>2000 psi/>13.8 MPa confining, >10 000 psi/>68.9 MPa vertical load) triaxial core holder suitable for X-ray CT scanning. The new triaxial system permits time-lapse imaging to capture the role of effective stress on fluid distribution and porous medium mechanics. System capabilities are demonstrated using ultimate compressive strength (UCS) tests of Castlegate sandstone. In this case, flooding the porous medium with a radio-opaque gas such as krypton before and after the UCS test improves the discrimination of rock features such as fractures. The results of high-temperature tests are also presented. A Uintah Basin sample of immature oil shale is heated from room temperature to 459 °C under uniaxial compression. The sample contains kerogen that pyrolyzes as temperature rises, releasing hydrocarbons. Imaging reveals the formation of stress bands as well as the evolution and connectivity of the fracture network within the sample as a function of time.

An experimental platform for triaxial high-pressure/high-temperature testing of rocks using computed tomography.

PubMed

Glatz, Guenther; Lapene, Alexandre; Castanier, Louis M; Kovscek, Anthony R

2018-04-01

A conventional high-pressure/high-temperature experimental apparatus for combined geomechanical and flow-through testing of rocks is not X-ray compatible. Additionally, current X-ray transparent systems for computed tomography (CT) of cm-sized samples are limited to design temperatures below 180 °C. We describe a novel, high-temperature (>400 °C), high-pressure (>2000 psi/>13.8 MPa confining, >10 000 psi/>68.9 MPa vertical load) triaxial core holder suitable for X-ray CT scanning. The new triaxial system permits time-lapse imaging to capture the role of effective stress on fluid distribution and porous medium mechanics. System capabilities are demonstrated using ultimate compressive strength (UCS) tests of Castlegate sandstone. In this case, flooding the porous medium with a radio-opaque gas such as krypton before and after the UCS test improves the discrimination of rock features such as fractures. The results of high-temperature tests are also presented. A Uintah Basin sample of immature oil shale is heated from room temperature to 459 °C under uniaxial compression. The sample contains kerogen that pyrolyzes as temperature rises, releasing hydrocarbons. Imaging reveals the formation of stress bands as well as the evolution and connectivity of the fracture network within the sample as a function of time.

A Mode Matched Triaxial Vibratory Wheel Gyroscope with Fully Decoupled Structure

PubMed Central

Xia, Dunzhu; Kong, Lun; Gao, Haiyu

2015-01-01

To avoid the oscillation of four unequal masses seen in previous triaxial linear gyroscopes, a modified silicon triaxial gyroscope with a rotary wheel is presented in this paper. To maintain a large sensitivity and suppress the coupling of different modes, this novel gyroscope structure is designed be perfectly symmetrical with a relatively large size of about 9.8 mm × 9.8 mm. It is available for differentially detecting three-axis angular rates simultaneously. To overcome the coupling between drive and sense modes, numerous necessary frames, beams, and anchors are delicately figured out and properly arranged. Besides, some frequency tuning and feedback mechanisms are addressed in the case of post processing after fabrication. To facilitate mode matched function, a new artificial fish swarm algorithm (AFSA) performed faster than particle swarm optimization (PSO) with a frequency split of 108 Hz. Then, by entrusting the post adjustment of the springs dimensions to the finite element method (FEM) software ANSYS, the final frequency splits can be below 3 Hz. The simulation results demonstrate that the modal frequencies in drive and different sense modes are respectively 8001.1, 8002.6, 8002.8 and 8003.3 Hz. Subsequently, different axis cross coupling effects and scale factors are also analyzed. The simulation results effectively validate the feasibility of the design and relevant theoretical calculation. PMID:26593916

Mechanical Behavior and Microcrack Development in Nominally Dry Synthetic Salt-rock During Cyclic Loading

NASA Astrophysics Data System (ADS)

Ding, J.; Chester, F. M.; Chester, J. S.; Zhu, C.; Shen, X.; Arson, C. F.

2016-12-01

Synthetic salt-rock is produced through uniaxial consolidation of sieved granular salt (0.3-0.355 mm grain diam.) at 75-107 MPa pressure and 100-200 0 C for 15 min duration, to produce low porosity (3%-6%) aggregates. Based on microstructural observations, consolidation mechanisms are grain rearrangement, intragranular plastic flow, and minor microfracture and recrystallization. Following consolidation, the salt-rock is deformed by cyclic, triaxial loading at room temperature and 4 MPa confining pressure to investigate microfracture development, closure and healing effects on elastic properties and flow strength. Load cycles are performed within the elastic regime, up to yielding, and during steady ductile flow. The mechanical properties are determined using an internal load cell and strain gages bonded to the samples. Elastic properties vary systematically during deformation reflecting cracking and pore and grain shape changes. Between triaxial load cycles, samples are held at isostatic loads for durations up to one day to determine healing rates and strength recovery; a change in mechanical behavior is observed when significant healing is induced. The microstructures of all samples are characterized before and after cyclic loading using optical microscopy. The consolidation and cyclic triaxial tests, and optical microscopy investigations, are conducted in a controlled low-humidity environment to ensure nominally dry conditions. The microstructures of samples from different stages of cyclic triaxial deformation indicate that intracrystalline plasticity, accompanied by minor recovery by recrystallization, is dominant; but, grain-boundary crack opening also becomes significant. Grain-boundary microcracks have preferred orientations that are sub-parallel to the load axis. The stress-strain behavior correlates with microcrack fabrics and densities during cyclic loading. These experiments are used to both inform and test continuum damage mechanics models of salt-rock deformation in the semibrittle domain, as well as to help design and optimize salt-rock storage facilities.

Deformation mechanisms of idealised cermets under multi-axial loading

NASA Astrophysics Data System (ADS)

Bele, E.; Goel, A.; Pickering, E. G.; Borstnar, G.; Katsamenis, O. L.; Pierron, F.; Danas, K.; Deshpande, V. S.

2017-05-01

The response of idealised cermets comprising approximately 60% by volume steel spheres in a Sn/Pb solder matrix is investigated under a range of axisymmetric compressive stress states. Digital volume correlation (DVC) anal`ysis of X-ray micro-computed tomography scans (μ-CT), and the measured macroscopic stress-strain curves of the specimens revealed two deformation mechanisms. At low triaxialities the deformation is granular in nature, with dilation occurring within shear bands. Under higher imposed hydrostatic pressures, the deformation mechanism transitions to a more homogeneous incompressible mode. However, DVC analyses revealed that under all triaxialities there are regions with local dilatory and compaction responses, with the magnitude of dilation and the number of zones wherein dilation occurs decreasing with increasing triaxiality. Two numerical models are presented in order to clarify these mechanisms: (i) a periodic unit cell model comprising nearly rigid spherical particles in a porous metal matrix and (ii) a discrete element model comprising a large random aggregate of spheres connected by non-linear normal and tangential "springs". The periodic unit cell model captured the measured stress-strain response with reasonable accuracy but under-predicted the observed dilation at the lower triaxialities, because the kinematic constraints imposed by the skeleton of rigid particles were not accurately accounted for in this model. By contrast, the discrete element model captured the kinematics and predicted both the overall levels of dilation and the simultaneous presence of both local compaction and dilatory regions with the specimens. However, the levels of dilation in this model are dependent on the assumed contact law between the spheres. Moreover, since the matrix is not explicitly included in the analysis, this model cannot be used to predict the stress-strain responses. These analyses have revealed that the complete constitutive response of cermets depends both on the kinematic constraints imposed by the particle aggregate skeleton, and the constraints imposed by the metal matrix filling the interstitial spaces in that skeleton.

A UNIFIED FRAMEWORK FOR THE ORBITAL STRUCTURE OF BARS AND TRIAXIAL ELLIPSOIDS

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

Valluri, Monica; Abbott, Caleb; Shen, Juntai

We examine a large random sample of orbits in two self-consistent simulations of N-body bars. Orbits in these bars are classified both visually and with a new automated orbit classification method based on frequency analysis. The well-known prograde x1 orbit family originates from the same parent orbit as the box orbits in stationary and rotating triaxial ellipsoids. However, only a small fraction of bar orbits (∼4%) have predominately prograde motion like their periodic parent orbit. Most bar orbits arising from the x1 orbit have little net angular momentum in the bar frame, making them equivalent to box orbits in rotatingmore » triaxial potentials. In these simulations a small fraction of bar orbits (∼7%) are long-axis tubes that behave exactly like those in triaxial ellipsoids: they are tipped about the intermediate axis owing to the Coriolis force, with the sense of tipping determined by the sign of their angular momentum about the long axis. No orbits parented by prograde periodic x2 orbits are found in the pure bar model, but a tiny population (∼2%) of short-axis tube orbits parented by retrograde x4 orbits are found. When a central point mass representing a supermassive black hole (SMBH) is grown adiabatically at the center of the bar, those orbits that lie in the immediate vicinity of the SMBH are transformed into precessing Keplerian orbits that belong to the same major families (short-axis tubes, long-axis tubes and boxes) occupying the bar at larger radii. During the growth of an SMBH, the inflow of mass and outward transport of angular momentum transform some x1 and long-axis tube orbits into prograde short-axis tubes. This study has important implications for future attempts to constrain the masses of SMBHs in barred galaxies using orbit-based methods like the Schwarzschild orbit superposition scheme and for understanding the observed features in barred galaxies.« less

Association of total marine fatty acids, eicosapentaenoic and docosahexaenoic acids, with aortic stiffness in Koreans, whites, and Japanese Americans.

PubMed

Sekikawa, Akira; Shin, Chol; Masaki, Kamal H; Barinas-Mitchell, Emma J M; Hirooka, Nobutaka; Willcox, Bradley J; Choo, Jina; White, Jessica; Evans, Rhobert W; Fujiyoshi, Akira; Okamura, Tomonori; Miura, Katsuyuki; Muldoon, Matthew F; Ueshima, Hirotsugu; Kuller, Lewis H; Sutton-Tyrrell, Kim

2013-11-01

Few previous studies have reported the association of aortic stiffness with marine n-3 fatty acids (Fas) in the general population. The aim of this study was to determine the combined and independent associations of 2 major marine n-3 FAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with aortic stiffness evaluated using carotid-femoral pulse wave velocity (cfPWV) in Korean, white, and Japanese American men. A population-based sample of 851 middle-aged men (299 Koreans, 266 whites, and 286 Japanese Americans) was examined for cfPWV during 2002-2006. Serum FAs, including EPA and DHA, were measured as a percentage of total FAs using gas chromatography. Multiple regression analysis was used to examine the association of EPA and DHA with cfPWV after adjusting for blood pressure and other confounders. Mean EPA and DHA levels were 1.9 (SD = 1.0) and 4.8 (SD = 1.4) for Koreans, 0.8 (SD = 0.6) and 2.4 (SD = 1.2) for whites, and 1.0 (SD = 1.0) and 3.2 (SD = 1.4) for Japanese Americans. Both EPA and DHA were significantly higher in Koreans than in the other 2 groups (P < 0.01). Multiple regression analyses in Koreans showed that cfPWV had a significant inverse association with total marine n-3 FAs and with EPA alone after adjusting for blood pressure and other potential confounders. In contrast, there was no significant association of cfPWV with DHA. Whites and Japanese Americans did not show any significant associations of cfPWV with total marine n-3 FAs, EPA, or DHA. High levels of EPA observed in Koreans have an inverse association with aortic stiffness. © American Journal of Hypertension, Ltd 2013. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Attitudes toward concordance and self-efficacy in decision making: a cross-sectional study on pharmacist-patient consultations.

PubMed

Ng, Yew Keong; Shah, Noraida Mohamed; Loong, Ly Sia; Pee, Lay Ting; Hidzir, Sarina Anim M; Chong, Wei Wen

2018-01-01

This study investigated patients' and pharmacists' attitudes toward concordance in a pharmacist-patient consultation and how patients' attitudes toward concordance relate to their involvement and self-efficacy in decision making associated with medication use. A cross-sectional study was conducted among patients with chronic diseases and pharmacists from three public hospitals in Malaysia. The Revised United States Leeds Attitudes toward Concordance (RUS-LATCon) was used to measure attitudes toward concordance in both patients and pharmacists. Patients also rated their perceived level of involvement in decision making and completed the Decision Self-Efficacy scale. One-way analysis of variance (ANOVA) and independent t -test were used to determine significant differences between different subgroups on attitudes toward concordance, and multiple linear regression was performed to find the predictors of patients' self-efficacy in decision making. A total of 389 patients and 93 pharmacists participated in the study. Pharmacists and patients scored M=3.92 (SD=0.37) and M=3.84 (SD=0.46) on the RUS-LATCon scale, respectively. Seven items were found to be significantly different between pharmacists and patients on the subscale level. Patients who felt fully involved in decision making (M=3.94, SD=0.462) scored significantly higher on attitudes toward concordance than those who felt partially involved (M=3.82, SD=0.478) and not involved at all (M=3.68, SD=0.471; p <0.001). Patients had an average score of 76.7% (SD=14.73%) on the Decision Self-Efficacy scale. In multiple linear regression analysis, ethnicity, number of medications taken by patients, patients' perceived level of involvement, and attitudes toward concordance are significant predictors of patients' self-efficacy in decision making ( p <0.05). Patients who felt involved in their consultations had more positive attitudes toward concordance and higher confidence in making an informed decision. Further study is recommended on interventions involving pharmacists in supporting patients' involvement in medication-related decision making.

Doubly Selective Multiple Quantum Chemical Shift Imaging and T1 Relaxation Time Measurement of Glutathione (GSH) in the Human Brain In Vivo

PubMed Central

Choi, In-Young; Lee, Phil

2012-01-01

Mapping of a major antioxidant, glutathione (GSH), was achieved in the human brain in vivo using a doubly selective multiple quantum filtering based chemical shift imaging (CSI) of GSH at 3 T. Both in vivo and phantom tests in CSI and single voxel measurements were consistent with excellent suppression of overlapping signals from creatine, γ-Amino butyric acid (GABA) and macromolecules. The GSH concentration in the fronto-parietal region was 1.20 ± 0.16 µmol/g (mean ± SD, n = 7). The longitudinal relaxation time (T1) of GSH in the human brain was 397 ± 44 ms (mean ± SD, n = 5), which was substantially shorter than those of other metabolites. This GSH CSI method permits us to address regional differences of GSH in the human brain with conditions where oxidative stress has been implicated, including multiple sclerosis, aging and neurodegenerative diseases. PMID:22730142

Impact of chronic cough on quality of life.

PubMed

French, C L; Irwin, R S; Curley, F J; Krikorian, C J

Cough is the most common complaint for which adult patients seek medical care in the United States; however, the reason(s) for this is unknown. To determine whether chronic cough was associated with adverse psychosocial or physical effects on the quality of life and whether the elimination of chronic cough with specific therapy improved these adverse effects. The study design was a prospective before-and-after intervention trial with patients serving as their own controls. Study subjects were a convenience sample of 39 consecutive and unselected adult patients referred for evaluation and management of a chronic, persistently troublesome cough. Baseline data were available for 39 patients and follow-up for 28 patients (22 women and 6 men). At baseline, demographic, Adverse Cough Outcome Survey (ACOS), and Sickness Impact Profile (SIP) data were collected and patients were managed according to a validated, systematic protocol. Following specific therapy for cough, ACOS and SIP instruments were readministered. The ages, sex, duration, and spectra and frequencies of the causes of cough were similar to multiple other studies. At baseline, patients reported a mean +/- SD of 8.6 +/- 4.8 types of adverse occurrences related to cough. There were significant correlations between multiple ACOS items and total, physical, and psychosocial SIP scores. Psychosocial score correlated with total number of symptoms (P<.02). After cough disappeared with treatment, ACOS complaints decreased to a mean +/- SD of 1.9 +/- 3.2 (P<.0001) as did total (mean +/- SD, 4.8 +/- 4.5 to 1.8 +/- 2.2) (P= .004), psychosocial (mean +/- SD, 4.2 +/- 6.8 to 0.8 +/- 2.3) (P = .004), and physical (mean +/- SD, 2.2 +/- 2.9 to 0.9 +/- 1.8) (P = .05) SIP scores. Multiple linear regression analysis showed that 54% of variability of the psychosocial SIP score was explained by 4 ACOS items while none of the physical score was explained. Chronic cough was associated with deterioration in patients' quality of life. The health-related dysfunction was most likely psychosocial. The ACOS and SIP appear to be valid tools in assessing the impact of chronic cough.

Evolution of Mechanical Properties and Microstructures in the Inner Accretionary Prism of the Nankai Subduction Zone

NASA Astrophysics Data System (ADS)

Kuo, S. T.; Kitamura, M.; Kitajima, H.

2016-12-01

Mechanical properties and microstructural characteristics of accretionary prism sediments can provide detailed deformation history and processes in subduction zones. The IODP Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Expedition 348 has extended the deep riser hole down to 3058.5 meters below sea floor (mbsf) to the inner accretionary wedge at Site C0002 located 35 km landward from the trench. Here, we conducted deformation experiments on the core samples recovered from 2185 msbf at Site C0002 to understand mechanical behaviors and deformation of inner prism sediments. We deformed the siltstone samples with a porosity of 20% at 25°C or 60°C under isotropic loading path (S1=S2=S3) and triaxial compression (S1>S2=S3). In the isotropic loading test, we step-wisely increased confining pressure (Pc) from 11.5 to 194 MPa and kept pore pressure (Pp) at 10 MPa. In a series of triaxial compression loading tests, we first increased Pc to the targeting 42-78 MPa and Pp to 20 MPa, and then applied the differential load at a constant displacement rate of 0.005 μm/s while keeping Pc and Pp constant. We will analyze the microstructures of the experimentally deformed samples to understand deformation mechanism. We define yield points based on slope changes in relationships between volumetric strain and effective mean stress (p') for isotropic loading and those between differential stress (q) and axial strain for triaxial loading. The sample yields at p' of 100 MPa (q = 0 MPa) in isotropic loading test. In triaxial loading, the samples at effective pressure (Pe) of 22, 28, and 58 MPa yield at q = 30 MPa (p' = 32 MPa), q = 30 MPa (p' = 38 MPa) and q = 45 MPa (p' = 73 MPa), respectively. Upon yield, the samples deformed at Pe of 22 MPa and 28 MPa show brittle behavior with a peak q of 50 MPa and 55 MPa followed by strain weakening to reach q of 36 and 46 MPa at steady state. Both samples show single fracture planes with angles of 30° to S1. On the other hand, the sample at Pe of 58 MPa shows strain hardening after the yield and exhibits barreling. In triaxial loading experiments, all samples show an increase in volumetric strain with increasing Pe. Our experiment results at different Pe are consistent with a critical state soil mechanics theory. We will further correlate the microstructural features of the deformed samples with the mechanical data.

Improving Students' Creative Thinking and Achievement through the Implementation of Multiple Intelligence Approach with Mind Mapping

ERIC Educational Resources Information Center

Widiana, I. Wayan; Jampel, I. Nyoman

2016-01-01

This classroom action research aimed to improve the students' creative thinking and achievement in learning science. It conducted through the implementation of multiple intelligences with mind mapping approach and describing the students' responses. The subjects of this research were the fifth grade students of SD 8 Tianyar Barat, Kubu, and…

Leptin and energy restriction induced adaptation in energy expenditure.

PubMed

Camps, Stefan G J A; Verhoef, Sanne P M; Westerterp, Klaas R

2015-10-01

Diet-induced weight loss is accompanied by adaptive thermogenesis, i.e. a disproportional reduction of resting energy expenditure (REE) a decrease in physical activity and increased movement economy. To determine if energy restriction induced adaptive thermogenesis and adaptations in physical activity are related to changes in leptin concentrations. Eighty-two healthy subjects (23 men, 59 women), mean ± SD age 41 ± 8 years and BMI 31.9 ± 3.0 kg/m(2), followed a very low energy diet for 8 weeks with measurements before and after the diet. Leptin concentrations were determined from fasting blood plasma. Body composition was assessed with a three-compartment model based on body weight, total body water (deuterium dilution) and body volume (BodPod). REE was measured (REEm) with a ventilated hood and predicted (REEp) from measured body composition. Adaptive thermogenesis was calculated as REEm/REEp. Parameters for the amount of physical activity were total energy expenditure expressed as a multiple of REEm (PAL), activity-induced energy expenditure divided by body weight (AEE/kg) and activity counts measured by a tri-axial accelerometer. Movement economy was calculated as AEE/kg (MJ/kg/d) divided by activity counts (Mcounts/d). Subjects lost on average 10.7 ± 4.1% body weight (P<0.001). Leptin decreased from 26.9 ± 14.3 before to 13.9 ± 11.3 μg/l after the diet (P<0.001). REEm/REEp after the diet (0.963 ± 0.08) was related to changes in leptin levels (R(2)=0.06; P<0.05). There was no significant correlation between changes in leptin concentrations and changes in amount of physical activity. Movement economy changed from 0.036 ± 0.011 J/kg/count to 0.028 ± 0.010 J/kg/count and was correlated to the changes in leptin concentrations (R(2)=0.07; P<0.05). During energy restriction, the decrease in leptin explains part of the variation in adaptive thermogenesis. Changes in leptin are not related to the amount of physical activity but could partly explain the increased movement economy. Copyright © 2015 Elsevier Inc. All rights reserved.

Visual and Quantitative Analysis Methods of Respiratory Patterns for Respiratory Gated PET/CT.

PubMed

Son, Hye Joo; Jeong, Young Jin; Yoon, Hyun Jin; Park, Jong-Hwan; Kang, Do-Young

2016-01-01

We integrated visual and quantitative methods for analyzing the stability of respiration using four methods: phase space diagrams, Fourier spectra, Poincaré maps, and Lyapunov exponents. Respiratory patterns of 139 patients were grouped based on the combination of the regularity of amplitude, period, and baseline positions. Visual grading was done by inspecting the shape of diagram and classified into two states: regular and irregular. Quantitation was done by measuring standard deviation of x and v coordinates of Poincaré map (SD x , SD v ) or the height of the fundamental peak ( A 1 ) in Fourier spectrum or calculating the difference between maximal upward and downward drift. Each group showed characteristic pattern on visual analysis. There was difference of quantitative parameters (SD x , SD v , A 1 , and MUD-MDD) among four groups (one way ANOVA, p = 0.0001 for MUD-MDD, SD x , and SD v , p = 0.0002 for A 1 ). In ROC analysis, the cutoff values were 0.11 for SD x (AUC: 0.982, p < 0.0001), 0.062 for SD v (AUC: 0.847, p < 0.0001), 0.117 for A 1 (AUC: 0.876, p < 0.0001), and 0.349 for MUD-MDD (AUC: 0.948, p < 0.0001). This is the first study to analyze multiple aspects of respiration using various mathematical constructs and provides quantitative indices of respiratory stability and determining quantitative cutoff value for differentiating regular and irregular respiration.

The association of long-term glycaemic variability versus sustained chronic hyperglycaemia with heart rate-corrected QT interval in patients with type 2 diabetes.

PubMed

Su, Jian-Bin; Yang, Xiao-Hua; Zhang, Xiu-Lin; Cai, Hong-Li; Huang, Hai-Yan; Zhao, Li-Hua; Xu, Feng; Chen, Tong; Cheng, Xing-Bo; Wang, Xue-Qin; Lu, Yan

2017-01-01

Prolonged heart rate-corrected QT(QTc) interval is related to ventricular arrhythmia and cardiovascular mortality, with considerably high prevalence of type 2 diabetes. Additionally, long-term glycaemic variability could be a significant risk factor for diabetic complications in addition to chronic hyperglycaemia. We compared the associations of long-term glycaemic variability versus sustained chronic hyperglycaemia with the QTc interval among type 2 diabetes patients. In this cross-sectional study, 2904 type 2 diabetes patients were recruited who had undergone at least four fasting plasma glucose (FPG) and 2-hour postprandial plasma glucose (PPG) measurements (at least once for every 3 months, respectively) during the preceding year. Long-term glycaemic variabilities of FPG and 2-hour PPG were assessed by their standard deviations (SD-FPG and SD-PPG, respectively), and chronic fasting and postprandial hyperglycaemia were assessed by their means (M-FPG and M-PPG, respectively). HbA1c was also determined upon enrolment to assess current overall glycaemic control. QTc interval was estimated from resting 12-lead electrocardiograms, and more than 440 ms was considered abnormally prolonged. Patients with prolonged QTc interval (≥440 ms) had greater M-FPG, M-PPG, SD-PPG and HbA1c than those with normal QTc interval but comparable SD-FPG. QTc interval was correlated with M-FPG, M-PPG, SD-PPG and HbA1c (r = 0.133, 0.153, 0.245 and 0.207, respectively, p = 0.000) but not with SD-FPG (r = 0.024, p = 0.189). After adjusting for metabolic risk factors via multiple linear regression analysis, SD-PPG, M-PPG and HbA1c (t = 12.16, 2.69 and 10.16, respectively, p = 0.000) were the major independent contributors to the increased QTc interval. The proportion of prolonged QTc interval increased significantly from 10.9% to 14.2% to 26.6% for the first (T1) to second (T2) to third (T3) tertiles of SD-PPG. After adjusting via multiple logistic regression analysis, the odd ratios of prolonged QTc interval of the T2 and T3 versus the T1 of SD-PPG were 1.15 (95% CI, 0.82-1.60) and 2.62 (1.92-3.57), respectively. Increased long-term variability of PPG is a strong independent risk factor for prolonged QTc interval in type 2 diabetes patients, in addition to long-term postprandial hyperglycaemia and current HbA1c.

Physical Activity Measurements: Lessons Learned from the Pathways Study

PubMed Central

Going, Scott B.

2015-01-01

High obesity rates in American Indian children led to Pathways, a randomized school and community-based childhood prevention study. Seven tribes, five universities, the NIH/NHLBI, and four elementary schools partnered. Increasing physical activity (PA) was an important intervention target. PA assessment was based on study objectives, feasibility, and tribal acceptance. A time-segmented analysis was also desired. Two methods were developed during pilot testing, a new PA questionnaire and accelerometry. Together, the methods provided qualitative and quantitative information and showed 3 of 4 sites were able to increase average daily PA, although overall the control versus intervention difference was not significant. The main limitation was inability to distinguish PA among individuals. Accelerometer size and some community concerns led to a protocol based on a single day of wearing time. Newer model triaxial accelerometers which are much smaller and allow sampling of multiple days of activity are recommended for future studies. PMID:20689391

Microseismic Monitoring of the Mounds Drill Cuttings Injection Tests

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

Branagan, P.T.; Mahrer, K.D.; Moschovidis, Z.A.

This paper describes the microseismic mapping of repeated injections of drill cuttings into two separate formations at a test site near Mounds, OK. Injections were performed in sandstone and shale formations at depths of 830 and 595 m, respectively. Typical injection disposal was simulated using multiple small-volume injections over a three-day period, with long shut-in periods interspersed between the injections. Microseismic monitoring was achieved using a 5-level array of wireline-run, triaxial- accelerometer receivers in a monitor well 76 m from the disposed well. Results of the mapped microseismic locations showed that the disposal domti W= generally aligns with the majormore » horizontal stress with some variations in azimuth and that wide variations in height and length growth occurred with continued injections. These experiments show that the cuttings injection process cm be adequately monitored from a downhole, wireline-run receiver array, thus providing process control and environmental assurance.« less

Spectroscopic study of the possibly triaxial transitional nucleus 75Ge

NASA Astrophysics Data System (ADS)

Niu, C. Y.; Dai, A. C.; Xu, C.; Hua, H.; Zhang, S. Q.; Wang, S. Y.; Bark, R. A.; Meng, J.; Wang, C. G.; Wu, X. G.; Li, X. Q.; Li, Z. H.; Wyngaardt, S. M.; Zang, H. L.; Chen, Z. Q.; Wu, H. Y.; Xu, F. R.; Ye, Y. L.; Jiang, D. X.; Han, R.; Li, C. G.; Chen, X. C.; Liu, Q.; Feng, J.; Yang, B.; Li, Z. H.; Wang, S.; Sun, D. P.; Liu, C.; Li, Z. Q.; Zhang, N. B.; Guo, R. J.; Li, G. S.; He, C. Y.; Zheng, Y.; Li, C. B.; Chen, Q. M.; Zhong, J.; Zhou, W. K.; Zhu, B. J.; Deng, L. T.; Liu, M. L.; Wang, J. G.; Jones, P.; Lawrie, E. A.; Lawrie, J. J.; Sharpey-Schafer, J. F.; Wiedeking, M.; Majola, S. N. T.; Bucher, T. D.; Dinoko, T.; Magabuka, B.; Makhathini, L.; Mdletshe, L.; Khumalo, N. A.; Shirinda, O.; Sowazi, K.

2018-03-01

The collective structures of 75Ge have been studied for the first time via the 74Ge(α ,2 p 1 n )75Ge fusion-evaporation reaction. Two negative-parity bands and one tentative positive-parity band built on the ν p1 /2,ν f5 /2 , and ν g9 /2 states, respectively, are established and compared with the structures in the neighboring N =43 isotones. According to the configuration-constrained potential-energy surface calculations, a shape transition from oblate to prolate along the isotopic chain in odd-A Ge isotopes is suggested to occur at 75Ge. The properties of the bands in 75Ge are analyzed in comparison with the triaxial particle rotor model calculations.

Study of Quantum Chaos in the Framework of Triaxial Rotator Models

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

Proskurins, J.; Bavrins, K.; Andrejevs, A.

2009-01-28

Dynamical quantum chaos criteria--a perturbed wave function entropy W({psi}{sub i}) and a fragmentation width {kappa}({phi}{sub k}) of basis states were studied in two cases of nuclear rigid triaxial rotator models. The first model is characterized by deformation angle {gamma} only, while the second model depends on both quadrupole deformation parameters ({beta},{gamma}). The degree of chaoticity has been determined in the studies of the dependence of criteria W({psi}{sub i}) and {kappa}({phi}{sub k}) from nuclear spin values up to I{<=}101 for model parameters {gamma} and ({beta},{gamma}) correspondingly. The transition from librational to rotational type energy spectra has been considered for both modelsmore » as well.« less

Low-lying structure and shape evolution in neutron-rich Se isotopes

NASA Astrophysics Data System (ADS)

Chen, S.; Doornenbal, P.; Obertelli, A.; Rodríguez, T. R.; Authelet, G.; Baba, H.; Calvet, D.; Château, F.; Corsi, A.; Delbart, A.; Gheller, J.-M.; Giganon, A.; Gillibert, A.; Lapoux, V.; Motobayashi, T.; Niikura, M.; Paul, N.; Roussé, J.-Y.; Sakurai, H.; Santamaria, C.; Steppenbeck, D.; Taniuchi, R.; Uesaka, T.; Ando, T.; Arici, T.; Blazhev, A.; Browne, F.; Bruce, A. M.; Caroll, R.; Chung, L. X.; Cortés, M. L.; Dewald, M.; Ding, B.; Flavigny, F.; Franchoo, S.; Górska, M.; Gottardo, A.; Jungclaus, A.; Lee, J.; Lettmann, M.; Linh, B. D.; Liu, J.; Liu, Z.; Lizarazo, C.; Momiyama, S.; Moschner, K.; Nagamine, S.; Nakatsuka, N.; Nita, C. R.; Nobs, C.; Olivier, L.; Orlandi, R.; Patel, Z.; Podolyak, Zs.; Rudigier, M.; Saito, T.; Shand, C.; Söderström, P.-A.; Stefan, I.; Vaquero, V.; Werner, V.; Wimmer, K.; Xu, Z.

2017-04-01

Neutron-rich 88,90,92,94Se isotopes were studied via in-beam γ -ray spectroscopy after nucleon removal reactions at intermediate energies at the Radioactive Isotope Beam Factory. Based on γ -γ coincidence analysis, low-lying excitation level schemes are proposed for these nuclei, including the 21+, 41+ states and 22+ states at remarkably low energies. The low-lying 22+ states, along with other features, indicate triaxiality in these nuclei. The experimental results are in good overall agreement with self-consistent beyond-mean-field calculations based on the Gogny D1S interaction, which suggests both triaxial degree of freedom and shape coexistence playing important roles in the description of intrinsic deformations in neutron-rich Se isotopes.

Multiple personality disorder among female inpatients in a state hospital.

PubMed

Latz, T T; Kramer, S I; Hughes, D L

1995-09-01

Professional skepticism and concerns regarding diagnostic reliability hinder research in dissociative disorders and multiple personality disorder. The reported frequency of multiple personality disorder in different psychiatric settings ranges from 2.4% to 35%. The authors conducted a replication study of multiple personality disorder ascertainment in women admitted to a state hospital over a 5.5-month period. Responses to the Dissociative Experiences Scale and to the Dissociative Disorders Interview Schedule were obtained, along with data on length of stay, county of admission referral, admission commitment status, and discharge diagnoses, for 176 female inpatients in a state hospital. Of 421 women representing 483 consecutive admissions, 121 were discharged before they could be assessed for study, 64 were excluded, 60 declined to participate, 176 enrolled in the study, and 175 completed the research procedures. Twenty-one women (12%) met criteria for multiple personality disorder based on the Dissociative Disorders Interview Schedule; these women were significantly younger than the women without multiple personality disorder. Scores on the Dissociative Experiences Scale of the women with multiple personality disorder (mean = 59.5, SD = 19.6) were significantly higher than the scores of women without multiple personality disorder (mean = 22.5, SD = 20.1), but considerable overlap occurred. There was no significant difference between groups in length of stay or admission status. The authors conclude that 1) the wide variability in multiple personality disorder detection is partially due to site-specific ascertainment biases and 2) despite its apparent usefulness for screening purposes, the Dissociative Experiences Scale requires more comprehensive evaluation before it can be applied broadly.

Memory training interventions for older adults: a meta-analysis.

PubMed

Gross, Alden L; Parisi, Jeanine M; Spira, Adam P; Kueider, Alexandra M; Ko, Jean Y; Saczynski, Jane S; Samus, Quincy M; Rebok, George W

2012-01-01

A systematic review and meta-analysis of memory training research was conducted to characterize the effect of memory strategies on memory performance among cognitively intact, community-dwelling older adults, and to identify characteristics of individuals and of programs associated with improved memory. The review identified 402 publications, of which 35 studies met criteria for inclusion. The overall effect size estimate, representing the mean standardized difference in pre-post change between memory-trained and control groups, was 0.31 standard deviations (SD; 95% confidence interval (CI): 0.22, 0.39). The pre-post training effect for memory-trained interventions was 0.43 SD (95% CI: 0.29, 0.57) and the practice effect for control groups was 0.06 SD (95% CI: 0.05, 0.16). Among 10 distinct memory strategies identified in studies, meta-analytic methods revealed that training multiple strategies was associated with larger training gains (p=0.04), although this association did not reach statistical significance after adjusting for multiple comparisons. Treatment gains among memory-trained individuals were not better after training in any particular strategy, or by the average age of participants, session length, or type of control condition. These findings can inform the design of future memory training programs for older adults.

Electron-electron interaction in Multiple Quantum Wells

NASA Astrophysics Data System (ADS)

Zybert, M.; Marchewka, M.; Tomaka, G.; Sheregii, E. M.

2012-07-01

The complex investigation of the magneto-transport effects in structures containing multiple quantum well (MQWs) based on the GaAs/AlGaAs-heterostructures has been performed. The MQWs investigated have different electron densities in QWs. The parameters of 2DEG in MQWs were determined from the data of the Integer Quantum Hall Effect (IQHE) and Shubnikov-de Haas oscillations (SdH) observed at low temperatures (0.6-4.2 K). The method of calculation of the electron states energies in MQWs has been developed which is based on the splitting of these states due to the exchange interaction (SAS-splitting, see D. Płoch et al., Phys. Rev. B 79 (2009) 195434) including the screening of this interaction. The IQHE and SdH observed in these multilayer structures with the third degree of freedom for electrons are interpreted from this.

On the origin of vorticity in magnetic particle suspensions subjected to triaxial fields

DOE PAGES

Martin, James E.

2016-06-06

We have recently reported that two classes of time-dependent triaxial magnetic fields can induce vorticity in magnetic particle suspensions. The first class – symmetry-breaking fields – is comprised of two ac components and one dc component. The second class – rational triad fields – is comprised of three ac components. In both cases deterministic vorticity occurs when the ratios of the field frequencies form rational numbers. A strange aspect of these fields is that they produce fluid vorticity without generally having a circulating field vector, such as would occur in a rotating field. It has been shown, however, that themore » symmetry of the field trajectory, considered jointly with that of the converse field, allows vorticity to occur around one particular field axis. This axis might be any of the field components, and is determined by the relative frequencies of the field components. However, the symmetry theories give absolutely no insight into why vorticity should occur. In this paper we propose a particle-based model of vorticity in these driven fluids. This model proposes that particles form volatile chains that follow, but lag behind, the dynamic field vector. Furthermore, this model is consistent with the predictions of symmetry theory and gives reasonable agreement with previously reported torque density measurements for a variety of triaxial fields.« less

Equilibrium figures inside the dark-matter ring and the shapes of elliptical galaxies

NASA Astrophysics Data System (ADS)

Kondratyev, B. P.; Trubitsyna, N. G.; Kireeva, E. N.

We solve the general problem of the theory of equilibrium figures and analyze two classes of liquid rotating gravitating figures residing inside a gravitating ring or torus. These figures form families of sequences of generalized oblate spheroids and triaxial ellipsoids, which at the lower limit of the tidal parameter α = 0 have the form of the Maclaurin spheroids and the Jacobi ellipsoids. In intermediate cases 0 < α ≤ αmax each new sequence of axisymmetric equilibrium figures has two non-rotating boundary spheroids. At the upper limit αmax/(π Gρ ) = 0.1867 the sequence degenerates into a single non-rotating spheroid with the eccentricity {e cr} ≈ 0.96 corresponding to the flattening limit of elliptical galaxies (E7). We also perform a detailed study of the sequences of generalized triaxial ellipsoids and find bifurcation points of triaxial ellipsoids in the sequences of generalized spheroids. We use this method to explain the shapes of E-galaxies. According to observations, very slowly rotating oblate E-type galaxies are known that have the shapes, which, because of instability, cannot be supported by velocity dispersion anisotropy exclusively. The hypothesis of a massive dark-matter outer ring requires no extreme anisotropy of pressure; it not only explains the shape of these elliptical galaxies, but also sheds new light on the riddle of the ellipticity limit (E7) of elliptical galaxies.

Tension Strength, Failure Prediction and Damage Mechanisms in 2D Triaxial Braided Composites with Notch

NASA Technical Reports Server (NTRS)

Norman, Timothy L.; Anglin, Colin

1995-01-01

The unnotched and notched (open hole) tensile strength and failure mechanisms of two-dimensional (2D) triaxial braided composites were examined. The effect of notch size and notch position were investigated. Damage initiation and propagation in notched and unnotched coupons were also examined. Theory developed to predict the normal stress distribution near an open hole and failure for tape laminated composites was evaluated for its applicability to 2D triaxial braided textile composite materials. Four different fiber architectures were considered; braid angle, yarn and braider size, percentage of longitudinal yarns and braider angle varied. Tape laminates equivalent to textile composites were also constructed for comparison. Unnotched tape equivalents were stronger than braided textiles but exhibited greater notch sensitivity. Notched textiles and tape equivalents have roughly the same strength at large notch sizes. Two common damage mechanisms were found: braider yarn cracking and near notch longitudinal yarn splitting. Cracking was found to initiate in braider yarns in unnotched and notched coupons, and propagate in the direction of the braider yarns until failure. Damage initiation stress decreased with increasing braid angle. No significant differences in prediction of near notch strain between textile and tape equivalents could be detected for small braid angle, but the correlations were weak for textiles with large braid angle. Notch strength could not be predicted using existing anisotropic theory for braided textiles due to their insensitivity to notch.

Determinants of severe dehydration from diarrheal disease at hospital presentation: Evidence from 22 years of admissions in Bangladesh

PubMed Central

Andrews, Jason R.; Leung, Daniel T.; Ahmed, Shahnawaz; Malek, Mohammed Abdul; Ahmed, Dilruba; Begum, Yasmin Ara; Qadri, Firdausi; Ahmed, Tahmeed; Faruque, Abu Syed Golam; Nelson, Eric J.

2017-01-01

Background To take advantage of emerging opportunities to reduce morbidity and mortality from diarrheal disease, we need to better understand the determinants of life-threatening severe dehydration (SD) in resource-poor settings. Methodology/findings We analyzed records of patients admitted with acute diarrheal disease over twenty-two years at the International Centre for Diarrhoeal Disease Research, Bangladesh (1993–2014). Patients presenting with and without SD were compared by multivariable logistic regression models, which included socio-demographic factors and pathogens isolated. Generalized additive models evaluated non-linearities between age or household income and SD. Among 55,956 admitted patients, 13,457 (24%) presented with SD. Vibrio cholerae was the most common pathogen isolated (12,405 patients; 22%), and had the strongest association with SD (AOR 4.77; 95% CI: 4.41–5.51); detection of multiple pathogens did not exacerbate SD risk. The highest proportion of severely dehydrated patients presented in a narrow window only 4–12 hours after symptom onset. Risk of presenting with SD increased sharply from zero to ten years of age and remained high throughout adolescence and adulthood. Adult women had a 38% increased odds (AOR 1.38; 95% CI: 1.30–1.46) of SD compared to adult men. The probability of SD increased sharply at low incomes. These findings were consistent across pathogens. Conclusions/significance There remain underappreciated populations vulnerable to life-threatening diarrheal disease that include adult women and the very poor. In addition to efforts that address diarrheal disease in young children, there is a need to develop interventions for these other high-risk populations that are accessible within 4 hours of symptom onset. PMID:28448489

Determinants of severe dehydration from diarrheal disease at hospital presentation: Evidence from 22 years of admissions in Bangladesh.

PubMed

Andrews, Jason R; Leung, Daniel T; Ahmed, Shahnawaz; Malek, Mohammed Abdul; Ahmed, Dilruba; Begum, Yasmin Ara; Qadri, Firdausi; Ahmed, Tahmeed; Faruque, Abu Syed Golam; Nelson, Eric J

2017-04-01

To take advantage of emerging opportunities to reduce morbidity and mortality from diarrheal disease, we need to better understand the determinants of life-threatening severe dehydration (SD) in resource-poor settings. We analyzed records of patients admitted with acute diarrheal disease over twenty-two years at the International Centre for Diarrhoeal Disease Research, Bangladesh (1993-2014). Patients presenting with and without SD were compared by multivariable logistic regression models, which included socio-demographic factors and pathogens isolated. Generalized additive models evaluated non-linearities between age or household income and SD. Among 55,956 admitted patients, 13,457 (24%) presented with SD. Vibrio cholerae was the most common pathogen isolated (12,405 patients; 22%), and had the strongest association with SD (AOR 4.77; 95% CI: 4.41-5.51); detection of multiple pathogens did not exacerbate SD risk. The highest proportion of severely dehydrated patients presented in a narrow window only 4-12 hours after symptom onset. Risk of presenting with SD increased sharply from zero to ten years of age and remained high throughout adolescence and adulthood. Adult women had a 38% increased odds (AOR 1.38; 95% CI: 1.30-1.46) of SD compared to adult men. The probability of SD increased sharply at low incomes. These findings were consistent across pathogens. There remain underappreciated populations vulnerable to life-threatening diarrheal disease that include adult women and the very poor. In addition to efforts that address diarrheal disease in young children, there is a need to develop interventions for these other high-risk populations that are accessible within 4 hours of symptom onset.

Low-Cost, Scalable Classroom-Based Approach to Promoting Physical Activity in Preschool Children

PubMed Central

McCrady-Spitzer, Shelly K; Sagdalen, Vanessa; Manohar, Chinmay U; Levine, James A

2017-01-01

Background This study examined the impact of short activity breaks in preschool children. The hypotheses were that preschool children receiving three five-minute activity breaks per day would increase (a) school time physical activity and (b) education scores compared to a control group not receiving the intervention. Methods For 8 weeks, the Intervention Group (n = 13) incorporated three 5-minute activity breaks into their classroom time while the Control Group (n = 12) did not incorporate the activity breaks. Physical activity was measured using a triaxial accelerometer. Education was assessed using standardized methods. Findings After 8 weeks, the preschool children in the Intervention Group increased their school time physical activity from 11,641 ± (SD) 1,368 Acceleration Units (AU)/ hour to 16,058 ± 2,253 AU/hour (P < 0.001). The children in the control group did not increase their physical activity (11,379 ± 2,427 cf 11,624 ± 2,441; ns). Students in the Intervention Group improved their education scores more than students in the control group (18 ± 12 cf 8 ± 7 points, P = 0.01); Letter Recognition improved in particular (9 ± 6 cf 2 ± 4 points, P = 0.001). Conclusions The incorporation of three 5-minute activity breaks was associated with increased school time physical activity and improved learning. PMID:28936491

A novel determination of energy expenditure efficiency during a balance task using accelerometers. A pilot study.

PubMed

Caña-Pino, Alejandro; Apolo-Arenas, Maria Dolores; Moral-Blanco, Javier; De la Cruz-Sánchez, Ernesto; Espejo-Antúnez, Luis

2017-08-18

The objectives of this study are to determine the displacement of the center of pressure (CoP) and its association with the spectral energy density of the acceleration required for the maintenance of postural balance in different standing positions in healthy participants using design observational and setting laboratorial studies. Participants were 30 healthy university students aged between 18 and 32 years old (mean [M] ± standard deviation [SD] = 21,57 ± 3,31 years). Triaxial accelerometer and a pressure platform were used in order to obtain energy spectral density and CoP sway measurements during four balance tasks. Statistically significant differences were found for anteroposterior (p = 0.002) and mediolateral (p = 0.009) CoP displacement between the conditions eyes closed and stable surface and the conditions eyes closed and unstable surface. A statistically significant correlation was also observed between Z-axis (anterior-posterior) of the accelerometer and mediolateral axis of the CoP (r = 0.465; p = 0.01) and between Y-axis accelerometer (mediolateral) and displacement of the CoP in the anteroposterior axis (r = 0.413; p = 0.023). Spectral energy density appears to be associated with the displacement of CoP in healthy participants.

Factors Associated With Patient-perceived Hoarseness in Spasmodic Dysphonia Patients.

PubMed

Hu, Amanda; Hillel, Al; Meyer, Tanya

2016-11-01

The American Academy of Otolaryngology-Head and Neck Surgery Clinical Practice Guidelines on Hoarseness distinguishes between hoarseness, which is a symptom perceived by the patient, and dysphonia, which is a diagnosis made by the clinician. Our objective was to determine factors that are associated with patient-perceived hoarseness in spasmodic dysphonia (SD) patients. Retrospective study. Adductor SD patients who presented for botulinum toxin injections from September 2011 to June 2012 were recruited. The main outcome variable, Voice Handicap Index-10 (VHI-10), was used to quantify patient-perceived hoarseness. Clinical data, Hospital Anxiety and Depression Scale (HADS), and VHI-10 were collected. Clinician-perceived dysphonia was measured by a speech-language pathologist with Consensus Auditory Perceptual Evaluation of Voice (CAPE-V). Statistical analysis included univariate analyses and multiple linear regression. One hundred thirty-nine SD patients had VHI-10 score of 26.0 ± 7.2 (mean ± standard deviation), disease duration of 10.5 + 7.0 years, CAPE-V overall score of 43.2 ± 21.8, HADS anxiety score of 6.7 ± 3.8, and HADS depression score of 3.6 ± 2.8. In univariate analyses, there were positive correlations (P < 0.05) between VHI-10 and female gender, CAPE-V overall, older age, HADS anxiety, and depression. There was no correlation with professional voice use and disease duration. In multiple linear regression (R 2  = 0.178, P < 0.001), age, HADS anxiety, female gender, and CAPE-V were significant. Older age, higher anxiety levels, female gender, and clinician-perceived dysphonia are associated with higher levels of patient-perceived hoarseness in SD patients. Hoarseness is a very personal symptom. Multiple factors determine its self-perception. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Constitutive Behavior and Finite Element Analysis of FRP Composite and Concrete Members.

PubMed

Ann, Ki Yong; Cho, Chang-Geun

2013-09-10

The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP) and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement effect of concrete from a three-dimensional failure surface in triaxial stress states. The constitutive behavior of the FRP composite was formulated from the two-dimensional classical lamination theory. To predict the flexural behavior of circular cross-section with FRP sheet and concrete composite, a layered discretization of cross-sections was incorporated into nonlinear isoparametric beam finite elements. The predicted constitutive behavior was validated by a comparison to available experimental results in the compressive and flexural beam loading test.

Triaxial thermopile array geo-heat-flow sensor

DOEpatents

Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

1990-01-01

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

The fracture characteristic of three collinear cracks under true triaxial compression.

PubMed

Liu, Jianjun; Zhu, Zheming; Wang, Bo

2014-01-01

The mechanical behavior of multicracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, experimental and numerical studies on the fracture property of three collinear cracks under compression were implemented. The specimens were a square concrete plate, and the cracks were made by a very thin film. The tests were conducted by using true triaxial loading device. In the numerical study, the Abaqus code was employed. The effect of crack orientation and the confining stress on cracked specimen compressive strength were investigated. The results show that the critical stresses of cracked specimens change with crack inclination angles, and, as the angle is 45°, the critical stress is the lowest; the critical stresses increase with the confining stresses.

Bioinspired Electronic White Cane Implementation Based on a LIDAR, a Tri-Axial Accelerometer and a Tactile Belt

PubMed Central

Pallejà, Tomàs; Tresanchez, Marcel; Teixidó, Mercè; Palacin, Jordi

2010-01-01

This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user’s forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment. PMID:22163529

Bioinspired electronic white cane implementation based on a LIDAR, a tri-axial accelerometer and a tactile belt.

PubMed

Pallejà, Tomàs; Tresanchez, Marcel; Teixidó, Mercè; Palacin, Jordi

2010-01-01

This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user's forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment.

The Fracture Characteristic of Three Collinear Cracks under True Triaxial Compression

PubMed Central

Liu, Jianjun; Zhu, Zheming; Wang, Bo

2014-01-01

The mechanical behavior of multicracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, experimental and numerical studies on the fracture property of three collinear cracks under compression were implemented. The specimens were a square concrete plate, and the cracks were made by a very thin film. The tests were conducted by using true triaxial loading device. In the numerical study, the Abaqus code was employed. The effect of crack orientation and the confining stress on cracked specimen compressive strength were investigated. The results show that the critical stresses of cracked specimens change with crack inclination angles, and, as the angle is 45°, the critical stress is the lowest; the critical stresses increase with the confining stresses. PMID:24790569

Experimental Research on Creep Characteristics of Nansha Soft Soil

PubMed Central

Luo, Qingzi; Chen, Xiaoping

2014-01-01

A series of tests were performed to investigate the creep characteristics of soil in interactive marine and terrestrial deposit of Pearl River Delta. The secondary consolidation test results show that the influence of consolidation pressure on coefficient of secondary consolidation is conditional, which is decided by the consolidation state. The ratio of coefficient of secondary consolidation and coefficient of compressibility C a/C c is almost a constant, and the value is 0.03. In the shear-box test, the direct sheer creep failure of soil is mainly controlled by shear stress rather than the accumulation of shear strain. The triaxial creep features are closely associated with the drainage conditions, and consolidation can weaken the effect of creep. When the soft soil has triaxial creep damage, the strain rate will increase sharply. PMID:24526925

Experimental research on creep characteristics of Nansha soft soil.

PubMed

Luo, Qingzi; Chen, Xiaoping

2014-01-01

A series of tests were performed to investigate the creep characteristics of soil in interactive marine and terrestrial deposit of Pearl River Delta. The secondary consolidation test results show that the influence of consolidation pressure on coefficient of secondary consolidation is conditional, which is decided by the consolidation state. The ratio of coefficient of secondary consolidation and coefficient of compressibility (Ca/Cc) is almost a constant, and the value is 0.03. In the shear-box test, the direct sheer creep failure of soil is mainly controlled by shear stress rather than the accumulation of shear strain. The triaxial creep features are closely associated with the drainage conditions, and consolidation can weaken the effect of creep. When the soft soil has triaxial creep damage, the strain rate will increase sharply.

A phoenics model for the triaxial loading of an initially cylindrical mass of rate-type material with provisions for bulging and yield

NASA Technical Reports Server (NTRS)

French, K. W., Jr.

1986-01-01

This work traces the response of a granular material via the Ten Coefficient Truesdell rate-type constituitive model into the simplest meaningful loading: the triaxial test configuration. A functional relation has been posed for computing the rather peculiar relation between average applied stress and average porosity. Using that relation an attack has been mounted on the dilemma that exists between dynamic and constitutive use of the pressure variable; that is relating dynamic pressure, thermodynamic pressure, stress deviator and higher stress invariants. The resolution was as a linear superposition with a one-way feedback, in that while the dynamic component could not effect the constituitive component, the converse was not true since density appears in the momentum transport relation.

The analysis of crystallographic symmetry types in finite groups

NASA Astrophysics Data System (ADS)

Sani, Atikah Mohd; Sarmin, Nor Haniza; Adam, Nooraishikin; Zamri, Siti Norziahidayu Amzee

2014-06-01

Undeniably, it is human nature to prefer objects which are considered beautiful. Most consider beautiful as perfection, hence they try to create objects which are perfectly balance in shape and patterns. This creates a whole different kind of art, the kind that requires an object to be symmetrical. This leads to the study of symmetrical objects and pattern. Even mathematicians and ethnomathematicians are very interested with the essence of symmetry. One of these studies were conducted on the Malay traditional triaxial weaving culture. The patterns derived from this technique are symmetrical and this allows for further research. In this paper, the 17 symmetry types in a plane, known as the wallpaper groups, are studied and discussed. The wallpaper groups will then be applied to the triaxial patterns of food cover in Malaysia.

Pharmacokinetic Properties and Tolerability of Cycloserine Following Oral Administration in Healthy Chinese Volunteers: A Randomized, Open-Label, Single- and Multiple-Dose 3-Way Crossover Study.

PubMed

Zhou, Huili; Wu, Guolan; Hu, Xingjiang; Zhu, Meixiang; Zhai, You; Liu, Jian; Shentu, Jianzhong; Wu, Lihua

2015-06-01

A new generic formulation of cycloserine has been developed in China but the pharmacokinetic properties of cycloserine in the Chinese population have not been reported. The aim of our study was to evaluate the pharmacokinetic properties and tolerability of single and multiple oral administrations of cycloserine capsules in healthy Chinese volunteers. This open-label, single- and multiple-dose 3-way crossover study was conducted in healthy Chinese volunteers. Subjects were randomized to receive a single dose of cycloserine (250, 500, or 1000 mg) in separate trial periods, with a 1-week washout between periods. Those allocated to the 250-mg dose continued into the multiple-dose phase, in which they received 250 mg BID for 5 consecutive days. During the single-dose phase, blood samples were collected at regular intervals from 0 to 72 hours after drug administration and the concentrations of cycloserine were determined using LC-MS/MS. During the multiple-dose phase, blood samples were obtained before drug administration on Days 4, 5, and 6 to determine the Cmin at steady state. On Day 6, blood samples were also collected from 0 to 72 hours after drug administration. Pharmacokinetic parameters were estimated using noncompartmental methods. Tolerability was determined using clinical evaluation and monitoring of adverse events. The study enrolled 12 healthy Chinese volunteers (6 men: mean [SD] age = 23.0 [2.6] years, weight = 60.2 [6.2] kg, height = 170.0 [3.0] cm, and body mass index = 20.7 [1.7]; 6 women: mean [SD] age = 25.3 [1.4] years, weight = 51.5 [3.3] kg, height = 160.0 [4.0] cm, and body mass index = 20.1 [0.9]). After administration of a single dose, cycloserine was rapidly absorbed, reaching peak plasma concentrations approximately 0.84 hours after oral administration, and t½ in plasma was about 13.0 hours. The geometric mean (SD) Cmax value increased in proportion to cycloserine dose, from 19.42 (5.89) to 84.76 (21.74) mg/L, and the geometric mean (SD) AUC0-72h value increased from 264.16 (133.37) to 1153.87 (522.16) mg·h/L in the range of a 250- to 1000-mg dose. After administration of multiple doses of cycloserine 250 mg BID, the mean (SD) t½ was 13.56 (4.38) hours, the apparent total clearance of the drug from plasma after oral administration was 1.02 (0.42) L/h, and the apparent volume of distribution was 18.22 (5.25) L, which were comparable with those after single dosing. The accumulation index was 2.19 (0.51), and the fluctuation was 1.05 (0.35). Results of the t tests of Cmax and AUC found no significant differences between the male and female groups. No serious adverse events were reported, and there were no discontinuations due to adverse events. The pharmacokinetic properties of cycloserine were linear at doses from 250 mg to 1000 mg. After multiple doses, the pharmacokinetic properties of cycloserine were consistent with those after single doses. At the doses studied, cycloserine appears to be well tolerated in these healthy volunteers. Chinese Clinical Trials registration: ChiCTR-TTRCC-13003982. Copyright © 2015. Published by Elsevier Inc.

Spiral interface: A reinforcing mechanism for laminated composite materials learned from nature

NASA Astrophysics Data System (ADS)

Gao, Yang; Guo, Zhenbin; Song, Zhaoqiang; Yao, Haimin

2017-12-01

Helical structures are ubiquitous in nature at length scales of a wide range. In this paper, we studied a helical architecture called microscopic screw dislocation (μ-SD), which is prevalently present in biological laminated composites such as shells of mollusks P. placenta and nacre of abalone. Mechanical characterization indicated that μ-SDs can greatly enhance resistance to scratching. To shed light on the underlying reinforcing mechanisms, we systematically investigated the mechanical behaviors of μ-SD using theoretical modeling in combination with finite element simulation. Our analysis on an individual μ-SD showed that the failure of a μ-SD under tension involves the delamination of the prolonged spiral interface, giving rise to much higher toughness compared to those of the planar counterpart. The corporation of multiple μ-SDs was further investigated by analyzing the effect of μ-SD density on the mechanical reinforcement. It was found that higher areal density of μ-SD would lead to more improvement in toughness. However, the operation of such reinforcing mechanism of μ-SD requires proclivity of cracking along the spiral interface, which is not spontaneous but conditional. Fracture mechanics-based modeling indicated that the proclivity of crack propagation along the spiral interface can be ensured if the fracture toughness of the interface is less than 60% of that of the lamina material. These findings not only uncover the reinforcing mechanisms of μ-SDs in biological materials but imply a great promise of applying μ-SDs in reinforcing synthetic laminated composites.

Statistical models for sediment/detritus and dissolved absorption coefficients in coastal waters of the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Green, Rebecca E.; Gould, Richard W., Jr.; Ko, Dong S.

2008-06-01

We developed statistically-based, optical models to estimate tripton (sediment/detrital) and colored dissolved organic matter (CDOM) absorption coefficients ( a sd, a g) from physical hydrographic and atmospheric properties. The models were developed for northern Gulf of Mexico shelf waters using multi-year satellite and physical data. First, empirical algorithms for satellite-derived a sd and a g were developed, based on comparison with a large data set of cruise measurements from northern Gulf shelf waters; these algorithms were then applied to a time series of ocean color (SeaWiFS) satellite imagery for 2002-2005. Unique seasonal timing was observed in satellite-derived optical properties, with a sd peaking most often in fall/winter on the shelf, in contrast to summertime peaks observed in a g. Next, the satellite-derived values were coupled with the physical data to form multiple regression models. A suite of physical forcing variables were tested for inclusion in the models: discharge from the Mississippi River and Mobile Bay, Alabama; gridded fields for winds, precipitation, solar radiation, sea surface temperature and height (SST, SSH); and modeled surface salinity and currents (Navy Coastal Ocean Model, NCOM). For satellite-derived a sd and a g time series (2002-2004), correlation and stepwise regression analyses revealed the most important physical forcing variables. Over our region of interest, the best predictors of tripton absorption were wind speed, river discharge, and SST, whereas dissolved absorption was best predicted by east-west wind speed, river discharge, and river discharge lagged by 1 month. These results suggest the importance of vertical mixing (as a function of winds and thermal stratification) in controlling a sd distribution patterns over large regions of the shelf, in comparison to advection as the most important control on a g. The multiple linear regression models for estimating a sd and a g were applied on a pixel-by-pixel basis and results were compared to monthly SeaWiFS composite imagery. The models performed well in resolving seasonal and interannual optical variability in model development years (2002-2004) (mean error of 32% for a sd and 29% for a g) and in predicting shelfwide optical patterns in a year independent of model development (2005; mean error of 41% for a sd and 46% for a g). The models provide insight into the dominant processes controlling optical distributions in this region, and they can be used to predict the optical fields from the physical properties at monthly timescales.

Attitudes toward concordance and self-efficacy in decision making: a cross-sectional study on pharmacist–patient consultations

PubMed Central

Ng, Yew Keong; Shah, Noraida Mohamed; Loong, Ly Sia; Pee, Lay Ting; Hidzir, Sarina Anim M; Chong, Wei Wen

2018-01-01

Purpose This study investigated patients’ and pharmacists’ attitudes toward concordance in a pharmacist–patient consultation and how patients’ attitudes toward concordance relate to their involvement and self-efficacy in decision making associated with medication use. Subjects and methods A cross-sectional study was conducted among patients with chronic diseases and pharmacists from three public hospitals in Malaysia. The Revised United States Leeds Attitudes toward Concordance (RUS-LATCon) was used to measure attitudes toward concordance in both patients and pharmacists. Patients also rated their perceived level of involvement in decision making and completed the Decision Self-Efficacy scale. One-way analysis of variance (ANOVA) and independent t-test were used to determine significant differences between different subgroups on attitudes toward concordance, and multiple linear regression was performed to find the predictors of patients’ self-efficacy in decision making. Results A total of 389 patients and 93 pharmacists participated in the study. Pharmacists and patients scored M=3.92 (SD=0.37) and M=3.84 (SD=0.46) on the RUS-LATCon scale, respectively. Seven items were found to be significantly different between pharmacists and patients on the subscale level. Patients who felt fully involved in decision making (M=3.94, SD=0.462) scored significantly higher on attitudes toward concordance than those who felt partially involved (M=3.82, SD=0.478) and not involved at all (M=3.68, SD=0.471; p<0.001). Patients had an average score of 76.7% (SD=14.73%) on the Decision Self-Efficacy scale. In multiple linear regression analysis, ethnicity, number of medications taken by patients, patients’ perceived level of involvement, and attitudes toward concordance are significant predictors of patients’ self-efficacy in decision making (p<0.05). Conclusion Patients who felt involved in their consultations had more positive attitudes toward concordance and higher confidence in making an informed decision. Further study is recommended on interventions involving pharmacists in supporting patients’ involvement in medication-related decision making. PMID:29731609

Proposal for defining the relevance of drug accumulation derived from single dose study data for modified release dosage forms

PubMed Central

Scheerans, Christian; Heinig, Roland; Mueck, Wolfgang

2015-01-01

Recently, the European Medicines Agency (EMA) published the new draft guideline on the pharmacokinetic and clinical evaluation of modified release (MR) formulations. The draft guideline contains the new requirement of performing multiple dose (MD) bioequivalence studies, in the case when the MR formulation is expected to show ‘relevant’ drug accumulation at steady state (SS). This new requirement reveals three fundamental issues, which are discussed in the current work: first, measurement for the extent of drug accumulation (MEDA) predicted from single dose (SD) study data; second, its relationship with the percentage residual area under the plasma concentration–time curve (AUC) outside the dosing interval (τ) after SD administration, %AUC(τ-∞)SD; and third, the rationale for a threshold of %AUC(τ-∞)SD that predicts ‘relevant’ drug accumulation at SS. This work revealed that the accumulation ratio RA,AUC, derived from the ratio of the time-averaged plasma concentrations during τ at SS and after SD administration, respectively, is the ‘preferred’ MEDA for MR formulations. A causal relationship was derived between %AUC(τ-∞)SD and RA,AUC, which is valid for any drug (product) that shows (dose- and time-) linear pharmacokinetics regardless of the shape of the plasma concentration–time curve. Considering AUC thresholds from other guidelines together with the causal relationship between %AUC(τ-∞)SD and RA,AUC indicates that values of %AUC(τ-∞)SD ≤ 20%, resulting in RA,AUC ≤ 1.25, can be considered as leading to non-relevant drug accumulation. Hence, the authors suggest that 20% for %AUC(τ-∞)SD is a reasonable threshold and selection criterion between SD or MD study designs for bioequivalence studies of new MR formulations. © 2014 The Authors Biopharmaceutics & Drug Disposition Published by John Wiley & Sons Ltd. PMID:25327367

Violent Relaxation, Dynamical Instabilities and the Formation of Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Aguilar, L. A.

1990-11-01

RESUMEN: El problema de la formaci6n de galaxias elfpticas por medjo de colapso gravitacional sin disipaci6n de energfa es estudiado usando un gran numero de simulaciones numericas. Se muestra que este tipo de colapsos, partiendo de condiciones iniciales frfas donde la energfa cinetica inicial representa s6lo un 5%, 0 , de a potencial inicial, produce sistemas relajados de forma triaxial muy similares a las galaxias elfpticas reales en sus formas y perfiles de densidad en proyecci6i . La forina triaxial resulta de la acci6n de una inestabilidad dinamica que aparece en sistemas 'inicos dominados por movimientos radiales, mientras que el perfil de densidad final Cs debido al llamado relajamiento violento que tiende a producir una distribuci6n en espacio fase unica. Estos dos fen6menos tienden a borrar los detalles particulares sobre las condiciones iniciales y dan lugar a una evoluci6n convergente hacia sistemas realistas, esto innecesario el uso de condiciones iniciales especiales (excepto por Ia condici6i de que estas deben ser frfas). Las condiciones iniciales frfas producen los movimientos radiales y fluctuaciones de la energfa potencial requeridos por ambos fen6menos. ABSTRACT: The problem of formation of elliptical galaxies via dissipationless collapse is studied using a large set of numerical simulations. It is shown that dissipationless collapses from cold initial conditions, where the total initial kinetic energy is less than 5% ofthe initial potential energy, lead to relaxed triaxial systems ery similar to real elliptical galaxies ii projected shape and density profiles. The triaxial shape is due to the of a dynamical instability that appears on systems dominated by radial orbits, while final density profile is due to violent relaxation that tends to produce a unique distribution iii space. These two phenomena erase memory of the initial prodtice a convergent evolution toward realistic systems, thus making unnecessary use o[special initial conditions (other than the condition ofbeing cold). Cold initial the radial orbits and large potential energy fluctuations necessary for both and are thus sufficient. KQ words: GALAXIES-DYNAMICS - GALAXIES-ELLIPTICAL - GALAXIES-FORMATION

Using Tri-Axial Accelerometry in Daily Elite Swim Training Practice.

PubMed

Ganzevles, Sander; Vullings, Rik; Beek, Peter Jan; Daanen, Hein; Truijens, Martin

2017-04-29

Background : Coaches in elite swimming carefully design the training programs of their swimmers and are keen on achieving strict adherence to those programs by their athletes. At present, coaches usually monitor the compliance of their swimmers to the training program with a stopwatch. However, this measurement clearly limits the monitoring possibilities and is subject to human error. Therefore, the present study was designed to examine the reliability and practical usefulness of tri-axial accelerometers for monitoring lap time, stroke count and stroke rate in swimming. Methods : In the first part of the study, a 1200 m warm-up swimming routine was measured in 13 elite swimmers using tri-axial accelerometers and synchronized video recordings. Reliability was determined using the typical error of measurement (TEM) as well as a Bland-Altman analysis. In the second part, training compliance both within and between carefully prescribed training sessions was assessed in four swimmers in order to determine the practical usefulness of the adopted accelerometric approach. In these sessions, targets were set for lap time and stroke count by the coach. Results : The results indicated high reliability for lap time (TEM = 0.26 s, bias = 0.74 [0.56 0.91] with limits of agreement (LoA) from -1.20 [-1.50 -0.90] to 2.70 [2.40 3.00]), stroke count (TEM 0.73 strokes, bias = 0.46 [0.32 0.60] with LoA from -1.70 [-1.94 -1.46] to 2.60 [2.36 2.84]) and stroke rate (TEM 0.72 str∙min -1 , bias = -0.13 [-0.20 -0.06] with LoA from -2.20 [-2.32 -2.08] to 1.90 [1.78 2.02]), while the results for the monitoring of training compliance demonstrated the practical usefulness of our approach in daily swimming training. Conclusions : The daily training of elite swimmers can be accurately and reliably monitored using tri-axial accelerometers. They provide the coach with more useful information to guide and control the training process than hand-clocked times.

The Shape of Extremely Metal-Poor Galaxies

NASA Astrophysics Data System (ADS)

Putko, Joseph; Sánchez Almeida, Jorge; Muñoz-Tuñón, Casiana; Elmegreen, Bruce; Elmegreen, Debra

2018-01-01

This work is the first study on the 3D shape of starbursting extremely metal-poor galaxies (XMPs; a galaxy is said to be an XMP if its ionized gas-phase metallicity is less than 1/10 the solar value). A few hundred XMPs have been identified in the local universe primarily through mining the spectroscopic catalog of the Sloan Digital Sky Survey (SDSS), and follow-up observations have shown that metallicity drops significantly at the starburst (compared to the quiescent component of the galaxy). As the timescale for gas mixing is short, the metal-poor gas triggering the starburst must have been accreted recently. This is strong observational evidence for the cold flow accretion predicted by cosmological models of galaxy formation, and, in this respect, XMPs seem to be the best local analogs of the very first galaxies.The ellipsoidal shape of a class of galaxies can be inferred from the observed axial ratio (q) distribution (q = minor axis/major axis) of a large sample of randomly-oriented galaxies. Fitting ellipses to 200 XMPs using r-band SDSS images, we observe that the axial ratio distribution falls off at q < ~0.4 and q > ~0.8, and we determine that these falloffs are not due to biases in the data. The falloff at low axial ratio indicates that the XMPs are thick for their size, and the falloff at high axial ratio suggests the vast majority of XMPs are triaxial. We also observe that smaller XMPs are thicker in proportion to their size, and it is expected that for decreasing galaxy size the ratio of random to rotational motions increases, which correlates with increasing relative thickness. The XMPs are low-redshift dwarf galaxies dominated by dark matter, and our results are compatible with simulations that have shown dark matter halos to be triaxial, with triaxial stellar distributions for low-mass galaxies and with triaxiality increasing over time. We will offer precise constraints on the 3D shape of XMPs via Bayesian analysis of our observed axial ratio distribution.This work has been supported by the La Caixa Foundation and the Estallidos Spanish Ministry of Science and Innovation grant.

Creation of short microwave ablation zones: in vivo characterization of single and paired modified triaxial antennas.

PubMed

Lubner, Meghan G; Ziemlewicz, Tim J; Hinshaw, J Louis; Lee, Fred T; Sampson, Lisa A; Brace, Christopher L

2014-10-01

To characterize modified triaxial microwave antennas configured to produce short ablation zones. Fifty single-antenna and 27 paired-antenna hepatic ablations were performed in domestic swine (N = 11) with 17-gauge gas-cooled modified triaxial antennas powered at 65 W from a 2.45-GHz generator. Single-antenna ablations were performed at 2 (n = 16), 5 (n = 21), and 10 (n = 13) minutes. Paired-antenna ablations were performed at 1-cm and 2-cm spacing for 5 (n = 7 and n = 8, respectively) and 10 minutes (n = 7 and n = 5, respectively). Mean transverse width, length, and aspect ratio of sectioned ablation zones were measured and compared. For single antennas, mean ablation zone lengths were 2.9 cm ± 0.45, 3.5 cm ± 0.55, and 4.2 cm ± 0.40 at 2, 5, and 10 minutes, respectively. Mean widths were 1.8 cm ± 0.3, 2.0 cm ± 0.32, and 2.5 cm ± 0.25 at 2, 5, and 10 minutes, respectively. For paired antennas, mean length at 5 minutes with 1-cm and 2-cm spacing and 10 minutes with 1-cm and 2-cm spacing was 4.2 cm ± 0.9, 4.9 cm ± 1.0, 4.8 cm ± 0.5, and 4.8 cm ± 1.3, respectively. Mean width was 3.1 cm ± 1.0, 4.4 cm ± 0.7, 3.8 cm ± 0.4, and 4.5 cm ± 0.7, respectively. Paired-antenna ablations were more spherical (aspect ratios, 0.72-0.79 for 5-10 min) than single-antenna ablations (aspect ratios, 0.57-0.59). For paired-antenna ablations, 1-cm spacing appeared optimal, with improved circularity and decreased clefting compared with 2-cm spacing (circularity, 0.85 at 1 cm, 0.78 at 2 cm). Modified triaxial antennas can generate relatively short, spherical ablation zones. Paired-antenna ablations were rounder and larger in transverse dimension than single antenna ablations, with 1-cm spacing optimal for confluence of the ablation zone. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

Micromechanics based simulation of ductile fracture in structural steels

NASA Astrophysics Data System (ADS)

Yellavajjala, Ravi Kiran

The broader aim of this research is to develop fundamental understanding of ductile fracture process in structural steels, propose robust computational models to quantify the associated damage, and provide numerical tools to simplify the implementation of these computational models into general finite element framework. Mechanical testing on different geometries of test specimens made of ASTM A992 steels is conducted to experimentally characterize the ductile fracture at different stress states under monotonic and ultra-low cycle fatigue (ULCF) loading. Scanning electron microscopy studies of the fractured surfaces is conducted to decipher the underlying microscopic damage mechanisms that cause fracture in ASTM A992 steels. Detailed micromechanical analyses for monotonic and cyclic loading are conducted to understand the influence of stress triaxiality and Lode parameter on the void growth phase of ductile fracture. Based on monotonic analyses, an uncoupled micromechanical void growth model is proposed to predict ductile fracture. This model is then incorporated in to finite element program as a weakly coupled model to simulate the loss of load carrying capacity in the post microvoid coalescence regime for high triaxialities. Based on the cyclic analyses, an uncoupled micromechanics based cyclic void growth model is developed to predict the ULCF life of ASTM A992 steels subjected to high stress triaxialities. Furthermore, a computational fracture locus for ASTM A992 steels is developed and incorporated in to finite element program as an uncoupled ductile fracture model. This model can be used to predict the ductile fracture initiation under monotonic loading in a wide range of triaxiality and Lode parameters. Finally, a coupled microvoid elongation and dilation based continuum damage model is proposed, implemented, calibrated and validated. This model is capable of simulating the local softening caused by the various phases of ductile fracture process under monotonic loading for a wide range of stress states. Novel differentiation procedures based on complex analyses along with existing finite difference methods and automatic differentiation are extended using perturbation techniques to evaluate tensor derivatives. These tensor differentiation techniques are then used to automate nonlinear constitutive models into implicit finite element framework. Finally, the efficiency of these automation procedures is demonstrated using benchmark problems.

Creation of short microwave ablation zones: In Vivo Characterization of single and paired Modified Triaxial Antennas Laboratory Investigation

PubMed Central

Lubner, Meghan G.; Ziemlewicz, Tim J; Hinshaw, J. Louis; Lee, Fred T.; Sampson, Lisa J.; Brace, Chris L.

2014-01-01

Purpose To characterize modified triaxial microwave antennas configured to produce short ablation zones. Materials and Methods 50 single- and 27 paired-antenna hepatic ablations were performed in domestic swine (n=11) with 17-gauge, gas-cooled modified triaxial antennas powered at 65W from a 2.45 GHz generator. Single-antenna ablations were performed at 2 (n=16), 5 (n=21), and 10 (n=13) minutes. Paired-antenna ablations were performed at 1-cm and 2-cm spacing for 5 (n=7, n=8) and 10 minutes (n=7, n=5). Mean transverse width, length and aspect ratio of sectioned ablation zones were measured and compared. Results For single antennas, mean ablation zone length was 2.9±0.45, 3.5±0.55 and 4.2±0.40 cm at 2, 5, and 10 minutes respectively. Mean width was 1.8±0.3, 2.0±0.32, 2.5±0.25 cm at 2, 5, and 10 minutes. For paired antennas, mean length at 5 min 1 and 2 cm and 10 min 1 and 2 cm spacing was 4.2±0.9, 4.4±0.9, 4.8±0.5 and 4.3±0.9 cm respectively. Mean width was 3.1±1.0, 4.0±0.8 and 3.8±0.4, 4.2±0.6 cm respectively. Paired-antenna ablations were more spherical (aspect ratios 0.72-0.79 for 5-10 min) than single-antenna ablations (0.57-0.59). For paired-antenna ablations, 1 cm spacing appeared optimal, with improved circularity and decreased clefting compared to 2 cm spacing (circ 1 cm 0.85, 2 cm 0.78). Conclusion Modified triaxial antennas can generate relatively short, spherical ablation zones. Paired-antenna ablations were rounder and larger in transverse dimension compared to single antenna ablations, with 1 cm spacing optimal for confluence of the ablation zone. PMID:25156644

Using Tri-Axial Accelerometry in Daily Elite Swim Training Practice

PubMed Central

Ganzevles, Sander; Vullings, Rik; Beek, Peter Jan; Daanen, Hein; Truijens, Martin

2017-01-01

Background: Coaches in elite swimming carefully design the training programs of their swimmers and are keen on achieving strict adherence to those programs by their athletes. At present, coaches usually monitor the compliance of their swimmers to the training program with a stopwatch. However, this measurement clearly limits the monitoring possibilities and is subject to human error. Therefore, the present study was designed to examine the reliability and practical usefulness of tri-axial accelerometers for monitoring lap time, stroke count and stroke rate in swimming. Methods: In the first part of the study, a 1200 m warm-up swimming routine was measured in 13 elite swimmers using tri-axial accelerometers and synchronized video recordings. Reliability was determined using the typical error of measurement (TEM) as well as a Bland-Altman analysis. In the second part, training compliance both within and between carefully prescribed training sessions was assessed in four swimmers in order to determine the practical usefulness of the adopted accelerometric approach. In these sessions, targets were set for lap time and stroke count by the coach. Results: The results indicated high reliability for lap time (TEM = 0.26 s, bias = 0.74 [0.56 0.91] with limits of agreement (LoA) from −1.20 [−1.50 −0.90] to 2.70 [2.40 3.00]), stroke count (TEM 0.73 strokes, bias = 0.46 [0.32 0.60] with LoA from −1.70 [−1.94 −1.46] to 2.60 [2.36 2.84]) and stroke rate (TEM 0.72 str∙min−1, bias = −0.13 [−0.20 −0.06] with LoA from −2.20 [−2.32 −2.08] to 1.90 [1.78 2.02]), while the results for the monitoring of training compliance demonstrated the practical usefulness of our approach in daily swimming training. Conclusions: The daily training of elite swimmers can be accurately and reliably monitored using tri-axial accelerometers. They provide the coach with more useful information to guide and control the training process than hand-clocked times. PMID:28468255

Signal Normalization Reduces Image Appearance Disparity Among Multiple Optical Coherence Tomography Devices.

PubMed

Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Schuman, Joel S

2017-02-01

To assess the effect of the previously reported optical coherence tomography (OCT) signal normalization method on reducing the discrepancies in image appearance among spectral-domain OCT (SD-OCT) devices. Healthy eyes and eyes with various retinal pathologies were scanned at the macular region using similar volumetric scan patterns with at least two out of three SD-OCT devices at the same visit (Cirrus HD-OCT, Zeiss, Dublin, CA; RTVue, Optovue, Fremont, CA; and Spectralis, Heidelberg Engineering, Heidelberg, Germany). All the images were processed with the signal normalization. A set of images formed a questionnaire with 24 pairs of cross-sectional images from each eye with any combination of the three SD-OCT devices either both pre- or postsignal normalization. Observers were asked to evaluate the similarity of the two displayed images based on the image appearance. The effects on reducing the differences in image appearance before and after processing were analyzed. Twenty-nine researchers familiar with OCT images participated in the survey. Image similarity was significantly improved after signal normalization for all three combinations ( P ≤ 0.009) as Cirrus and RTVue combination became the most similar pair, followed by Cirrus and Spectralis, and RTVue and Spectralis. The signal normalization successfully minimized the disparities in the image appearance among multiple SD-OCT devices, allowing clinical interpretation and comparison of OCT images regardless of the device differences. The signal normalization would enable direct OCT images comparisons without concerning about device differences and broaden OCT usage by enabling long-term follow-ups and data sharing.

Trial of a Novel Intervention to Improve Multiple Food Hygiene Behaviors in Nepal

PubMed Central

Gautam, Om Prasad; Schmidt, Wolf-Peter; Cairncross, Sandy; Cavill, Sue; Curtis, Valerie

2017-01-01

In this study, we report on the results of a trial of an intervention to improve five food hygiene behaviors among mothers of young children in rural Nepal. This novel intervention targeted five behaviors; cleanliness of serving utensils, handwashing with soap before feeding, proper storage of cooked food, and thorough reheating and water treatment. Based on formative research and a creative process using the Behavior-Centered Design approach, an innovative intervention package was designed and delivered over a period of 3 months. The intervention activities included local rallies, games, rewards, storytelling, drama, competitions linking with emotional drivers of behavior, and “kitchen makeovers” to disrupt behavior settings. The effect of the package on behavior was evaluated via a cluster-randomized before–after study in four villages with four villages serving as controls. The primary outcome was the difference in the mean cluster level proportions of mothers directly observed practicing all five food hygiene behaviors. The five targeted food hygiene behaviors were rare at baseline (composite performance of all five behaviors in intervention 1% [standard deviation (SD) = 2%] and in control groups 2% [SD = 2%]). Six weeks after the intervention, the target behaviors were more common in the intervention than in the control group (43% [SD = 14%] versus 2% [SD = 2%], P = 0.02) during follow-up. The intervention appeared to be equally effective in improving all five behaviors in all intervention clusters. This study shows that a theory-driven, systematic approach employing emotional motivators and modifying behavior settings was capable of substantially improving multiple food hygiene behaviors in Nepal. PMID:28719285

Trial of a Novel Intervention to Improve Multiple Food Hygiene Behaviors in Nepal.

PubMed

Gautam, Om Prasad; Schmidt, Wolf-Peter; Cairncross, Sandy; Cavill, Sue; Curtis, Valerie

2017-06-01

AbstractIn this study, we report on the results of a trial of an intervention to improve five food hygiene behaviors among mothers of young children in rural Nepal. This novel intervention targeted five behaviors; cleanliness of serving utensils, handwashing with soap before feeding, proper storage of cooked food, and thorough reheating and water treatment. Based on formative research and a creative process using the Behavior-Centered Design approach, an innovative intervention package was designed and delivered over a period of 3 months. The intervention activities included local rallies, games, rewards, storytelling, drama, competitions linking with emotional drivers of behavior, and "kitchen makeovers" to disrupt behavior settings. The effect of the package on behavior was evaluated via a cluster-randomized before-after study in four villages with four villages serving as controls. The primary outcome was the difference in the mean cluster level proportions of mothers directly observed practicing all five food hygiene behaviors. The five targeted food hygiene behaviors were rare at baseline (composite performance of all five behaviors in intervention 1% [standard deviation (SD) = 2%] and in control groups 2% [SD = 2%]). Six weeks after the intervention, the target behaviors were more common in the intervention than in the control group (43% [SD = 14%] versus 2% [SD = 2%], P = 0.02) during follow-up. The intervention appeared to be equally effective in improving all five behaviors in all intervention clusters. This study shows that a theory-driven, systematic approach employing emotional motivators and modifying behavior settings was capable of substantially improving multiple food hygiene behaviors in Nepal.

Study Behaviors and USMLE Step 1 Performance: Implications of a Student Self-Directed Parallel Curriculum.

PubMed

Burk-Rafel, Jesse; Santen, Sally A; Purkiss, Joel

2017-11-01

To determine medical students' study behaviors when preparing for the United States Medical Licensing Examination (USMLE) Step 1, and how these behaviors are associated with Step 1 scores when controlling for likely covariates. The authors distributed a study-behaviors survey in 2014 and 2015 at their institution to two cohorts of medical students who had recently taken Step 1. Demographic and academic data were linked to responses. Descriptive statistics, bivariate correlations, and multiple linear regression analyses were performed. Of 332 medical students, 274 (82.5%) participated. Most students (n = 211; 77.0%) began studying for Step 1 during their preclinical curriculum, increasing their intensity during a protected study period during which they averaged 11.0 hours studying per day (standard deviation [SD] 2.1) over a period of 35.3 days (SD 6.2). Students used numerous third-party resources, including reading an exam-specific 700-page review book on average 2.1 times (SD 0.8) and completing an average of 3,597 practice multiple-choice questions (SD 1,611). Initiating study prior to the designated study period, increased review book usage, and attempting more practice questions were all associated with higher Step 1 scores, even when controlling for Medical College Admission Test scores, preclinical exam performance, and self-identified score goal (adjusted R = 0.56, P < .001). Medical students at one public institution engaged in a self-directed, "parallel" Step 1 curriculum using third-party study resources. Several study behaviors were associated with improved USMLE Step 1 performance, informing both institutional- and student-directed preparation for this high-stakes exam.

24-hour aortic blood pressure variability showed a stronger association with carotid damage than 24-hour brachial blood pressure variability: The SAFAR study.

PubMed

Yu, Shikai; Chi, Chen; Protogerou, Athanase D; Safar, Michel E; Blacher, Jacques; Argyris, Antonis A; Nasothimiou, Efthimia G; Sfikakis, Petros P; Papaioannou, Theodore G; Xu, Henry; Zhang, Yi; Xu, Yawei

2018-03-01

We aim to compare 24-hour aortic blood pressure variability (BPV) with brachial BPV in relation to carotid damage as estimated by carotid intima-media thickness (CIMT) and cross-sectional area (CCSA). Four hundred and forty five individuals received brachial and aortic 24-hour ambulatory BP monitoring with a validated device (Mobil-O-Graph). Systolic BPV was estimated by average real variability (ARV) and time-weighted standard deviation (wSD). In multiple logistic regression analysis, CIMT > 900 μm was significantly and independently associated with aortic ARV (OR = 1.38; 95% CI: 1.04-1.84), aortic wSD (OR = 1.65; 95% CI: 1.19-2.29) and brachial ARV (OR = 1.53; 95% CI: 1.07-2.18), but not with brachial wSD. CCSA > 90th percentile was significantly and independently associated with aortic ARV (OR = 1.50; 95% CI: 1.07-2.10) and wSD (OR = 1.70; 95% CI: 1.12-2.56), but not with brachial BPVs. In receiver operator characteristics curve analysis, aortic wSD identified CCSA > 90th percentile better than brachial wSD (AUC: 0.73 vs 0.68, P < .01). In conclusion, aortic 24-hour systolic BPV showed a slightly stronger association with carotid damage than brachial BPV. ©2018 Wiley Periodicals, Inc.

Effects of solid dispersion and self-emulsifying formulations on the solubility, dissolution, permeability and pharmacokinetics of isorhamnetin, quercetin and kaempferol in total flavones of Hippophae rhamnoides L.

PubMed

Zhao, Guoying; Duan, Jingze; Xie, Yan; Lin, Guobei; Luo, Huilin; Li, Guowen; Yuan, Xiurong

2013-07-01

The aim of this study was to investigate the effects of solid dispersions (SD) and self-emulsifying (SE) formulations on the solubility and absorption properties of active components in total flavones of Hippophae rhamnoides L. (TFH). The solubility, dissolution rate, permeability and pharmacokinetics of isorhamnetin, quercetin and kaempferol in TFH SD/SE formulations and TFH were compared. The results showed that the solubility and dissolution rate of isorhamnetin, quercetin and kaempferol in SD/SE formulations were significantly enhanced compared to those in TFH, however, their intestinal permeability was comparable. The bioavailability of isorhamnetin, quercetin and kaempferol in rats remarkably increased after oral administration of TFH SD formulations compared to TFH, but there was no significant increase after oral administration of TFH SE formulations. The results of this study indicated the SD formulations on the improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH were much better than those of SE formulations. The improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH by SD formulations was probably ascribed to the enhancement of the solubility and dissolution of the three components, but was not relevant to the intestinal permeability. Therefore, as for herb extracts containing multiple components, especially for their major components with poor water solubility, solid dispersion formulations might have the better potential to enhance their bioavailability.

Return to work after severe multiple injuries: a multidimensional approach on status 1 and 2 years postinjury.

PubMed

Soberg, Helene Lundgaard; Finset, Arnstein; Bautz-Holter, Erik; Sandvik, Leiv; Roise, Olav

2007-02-01

The assessment of factors associated with return to work (RTW) after multiple trauma is important in trauma research. Goals in rehabilitation should comprise RTW. The purpose of this study was to examine the RTW rate and which factors predicted RTW for patients with severe multiple injuries using a prospective cohort design. In all, 100 patients with a New Injury Severity Score (NISS) >15, aged 18 to 67 years and admitted to a trauma referral center, were included starting January 2002 through June 2003. Outcomes were assessed 6 weeks after discharge and 1 and 2 years postinjury. Instruments were the Brief Approach/Avoidance Coping Questionnaire, Multidimensional Health Locus of Control, Short Form-36, the World Health Organization Disability Assessment Schedule II, and a cognitive function scale (COG). Mean age was 34.5 years (SD 13.5), 83% were male, and 66% were blue-collar workers. Mean NISS was 35.1 (SD 12.7). At 1 year, 28% achieved complete RTW, 43% at 2 years. Mean time back to work was 12.8 months (SD 5.9). Differences between the RTW and not complete RTW (NRTW) groups concerned personal and demographic variables, and physical and psychosocial functioning. Survival analysis showed that risk factors for NRTW were lower education, length of stay in hospital/rehabilitation >20 weeks, and low social functioning shortly after the return home. The majority of the patients had not completely returned to work 2 years postinjury. Demographic and injury related factors and social functioning were significant predictors of RTW status.

[Sensitivity and specificity of optical coherence tomography in diagnosing polypoidal choroidal vasculopathy].

PubMed

Zhang, Yi; Yao, Jing; Wang, Xiao-Hua; Zhao, Lin; Wang, Li-Jun; Wang, Jian-Ming; Zhou, Ai-Yi

2016-02-20

To establish the diagnostic criteria for polypoidal choroidal vasculopathy (PCV) based on spectral-domain optical coherence tomography (SD OCT) by evaluating the sensitivity and specificity of SD OCT in differentiating PCV from wet age-related macular degeneration (wAMD). The clinical data were reviewed for 62 patients (63 eyes) with the initial diagnosis of PCV or wAMD between August, 2012 and June, 2016. Twenty-four patients (25 eyes) were diagnosed to have PCV and 38 (38 eyes) had wAMD based on findings by fundus photography, fluorescein angiography (FFA) and indocyanine green angiography (ICGA). Among the 6 features of SD OCT, namely a sharp RPED peak, double-layer sign, multiple RPED, an RPED notch, a hyporeflective lumen representing polyps, and hyperreflective intraretinal hard exudates, findings of the first two features and at least one of the other features sufficed the diagnosis of PCV; in the absence of the first two features, the diagnosis of PCV was also made when at least 3 of the other features were present simultaneously. The sensitivity and specificity of SD OCT-based diagnosis were estimated by comparison with the gold standard ICGA-based diagnosis. In the 25 eyes with an established diagnosis of PCV, 23 eyes (92.0%) met the diagnostic criteria based on SD OCT findings; in the 38 eyes with the diagnosis of wAMD, only 4 eyes (10.5%) met the criteria. The sensitivity and specificity of SD OCT-based diagnosis of PCV was 92.0% and 89.5%, respectively. s We established the diagnostic criteria for PCV based on SD OCT findings with a high sensitivity and specificity. SD OCT shows a strong capacity for differentiating PCV from wAMD.

Local amygdala structural differences with 3T MRI in patients with Alzheimer disease

PubMed Central

Cavedo, E.; Boccardi, M.; Ganzola, R.; Canu, E.; Beltramello, A.; Caltagirone, C.; Thompson, P.M.

2011-01-01

Objective: Histologic studies show that the amygdala is affected by Alzheimer disease (AD) pathology, and its medial aspect is the most involved. We aimed to assess in vivo local structural differences in the amygdala of patients with AD using high-field MRI. Methods: A total of 19 patients with AD (mean age 76, SD 6 years, mean Mini-Mental State Examination score [MMSE] 13, SD 4) and 19 healthy elderly controls (age 74, SD 5, MMSE 29, SD 1) were enrolled. The radial atrophy mapping technique was used to reconstruct the 3-dimensional surface of the amygdala. Maps of surface tissue loss in patients with AD vs controls were computed and statistically tested with permutation tests thresholded at p < 0.05, to correct for multiple comparisons. A digital atlas of the amygdalar nuclei was used to infer which nuclei were involved. Results: Both amygdalar volumes were significantly smaller in patients with AD (right 1,508 mm3, SD 418; left 1,646, SD 419) than controls (right 2,129 mm3, SD 316; left 2,077, SD 376; p < 0.002). In the dorsomedial part, significant local tissue loss (20%–30%) was mapped in the medial and central nuclei. Ventrally, the lateral nucleus (La) and the basolateral ventral medial nucleus (BLVM) were also involved (20%–30% loss). Conclusions: We found in vivo local structural differences in the amygdala of patients with AD. The nuclei involved have known connections to the hippocampus (BLVM, La) and olfactory system (medial nucleus) and with cholinergic pathways (central nucleus). This pattern is consistent with the known pathophysiology of neural systems affected by AD. PMID:21339500

Spiritual well-being of patients with multiple sclerosis.

PubMed

Allahbakhshian, Maryam; Jafarpour, Mahshid; Parvizi, Soroor

2011-01-01

Spiritual well-being is one of the fundamental concepts in chronic diseases which create meaning and purpose in life and is an important approach in promoting general health and quality of life. This study performed to determine the level of spiritual health and its dimensions in patients with multiple sclerosis (MS). 236 members of Iranian MS Society were volunteered to participate in a descriptive co-relational study. Spiritual well-being was evaluated by The Spiritual Well-Being Scale (SWBS) questionnaires in two religious and Existential dimensions. Descriptive statistics, ANOVA, t-test and Pearson correlation coefficient were used to analyse the data. The majority of patients (% 97.9) showed moderate spiritual well-being (mean score = 74.3, SD= 8.90). Although Existential well-being (mean score = 40.3, SD= 5.51) was higher than religious well- being (mean score = 33.9, SD= 4.88). A significant relationship was seen between economic status and the spiritual well-being. The results emphasize on the necessity of spiritual well-being as an effective factor on different aspects of these patients' life. This key point is useful and even necessary to be considered to design programs of care and cure for these patients in a country (like Iran) with cultural and religious beliefs. On the other hand, patients' economic status should be considered.

The effect of pelvic floor muscle training alone or in combination with electrostimulation in the treatment of sexual dysfunction in women with multiple sclerosis.

PubMed

Lúcio, A C; D'Ancona, C A L; Lopes, M H B M; Perissinotto, M C; Damasceno, B P

2014-11-01

Sexual dysfunction (SD) affects up to 80% of multiple sclerosis (MS) patients and pelvic floor muscles (PFMs) play an important role in the sexual function of these patients. The objective of this paper is to evaluate the impact of a rehabilitation program to treat lower urinary tract symptoms on SD of women with MS. Thirty MS women were randomly allocated to one of three groups: pelvic floor muscle training (PFMT) with electromyographic (EMG) biofeedback and sham neuromuscular electrostimulation (NMES) (Group I), PFMT with EMG biofeedback and intravaginal NMES (Group II), and PFMT with EMG biofeedback and transcutaneous tibial nerve stimulation (TTNS) (Group III). Assessments, before and after the treatment, included: PFM function, PFM tone, flexibility of the vaginal opening and ability to relax the PFMs, and the Female Sexual Function Index (FSFI) questionnaire. After treatment, all groups showed improvements in all domains of the PERFECT scheme. PFM tone and flexibility of the vaginal opening was lower after the intervention only for Group II. All groups improved in arousal, lubrication, satisfaction and total score domains of the FSFI questionnaire. This study indicates that PFMT alone or in combination with intravaginal NMES or TTNS contributes to the improvement of SD. © The Author(s), 2014.

Noninvasive individual and species identification of jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) in Belize, Central America using cross-species microsatellites and faecal DNA.

PubMed

Wultsch, Claudia; Waits, Lisette P; Kelly, Marcella J

2014-11-01

There is a great need to develop efficient, noninvasive genetic sampling methods to study wild populations of multiple, co-occurring, threatened felids. This is especially important for molecular scatology studies occurring in challenging tropical environments where DNA degrades quickly and the quality of faecal samples varies greatly. We optimized 14 polymorphic microsatellite loci for jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) and assessed their utility for cross-species amplification. Additionally, we tested their reliability for species and individual identification using DNA from faeces of wild felids detected by a scat detector dog across Belize in Central America. All microsatellite loci were successfully amplified in the three target species, were polymorphic with average expected heterozygosities of HE = 0.60 ± 0.18 (SD) for jaguars, HE = 0.65 ± 0.21 (SD) for pumas and HE = 0.70 ± 0.13 (SD) for ocelots and had an overall PCR amplification success of 61%. We used this nuclear DNA primer set to successfully identify species and individuals from 49% of 1053 field-collected scat samples. This set of optimized microsatellite multiplexes represents a powerful tool for future efforts to conduct noninvasive studies on multiple, wild Neotropical felids. © 2014 John Wiley & Sons Ltd.

Memory training interventions for older adults: A meta-analysis

PubMed Central

Gross, Alden L.; Parisi, Jeanine M.; Spira, Adam P.; Kueider, Alexandra M.; Ko, Jean Y.; Saczynski, Jane S.; Samus, Quincy M.; Rebok, George W.

2012-01-01

A systematic review and meta-analysis of memory training research was conducted to characterize the effect of memory strategies on memory performance among cognitively intact, community-dwelling older adults, and to identify characteristics of individuals and of programs associated with improved memory. The review identified 402 publications, of which 35 studies met criteria for inclusion. The overall effect size estimate, representing the mean standardized difference in pre-post change between memory-trained and control groups, was 0.31 standard deviations (SD; 95% confidence interval (CI): 0.22, 0.39). The pre-post training effect for memory-trained interventions was 0.43 SD (95% CI: 0.29, 0.57) and the practice effect for control groups was 0.06 SD (95% CI: -0.05, 0.16). Among 10 distinct memory strategies identified in studies, meta-analytic methods revealed that training multiple strategies was associated with larger training gains (p=0.04), although this association did not reach statistical significance after adjusting for multiple comparisons. Treatment gains among memory-trained individuals were not better after training in any particular strategy, or by the average age of participants, session length, or type of control condition. These findings can inform the design of future memory training programs for older adults. PMID:22423647

Selenium supplementation lowers insulin resistance and markers of cardio-metabolic risk in patients with congestive heart failure: a randomised, double-blind, placebo-controlled trial.

PubMed

Raygan, Fariba; Behnejad, Milad; Ostadmohammadi, Vahidreza; Bahmani, Fereshteh; Mansournia, Mohammad A; Karamali, Fatemeh; Asemi, Zatollah

2018-07-01

This study was carried out to evaluate the effects of Se supplementation on metabolic profiles in patients with congestive heart failure (CHF). This randomised double-blind, placebo-controlled trial was performed among fifty-three subjects with CHF, aged 45-85 years old. Subjects were randomly allocated into two groups to take either 200 µg/d of Se as Se yeast (n 26) or placebo (n 27) for 12 weeks. Metabolic profiles were assessed at baseline and at the end of trial. Compared with the placebo, Se supplementation led to significant reductions in serum insulin (-18·41 (sd 27·53) v. +13·73 (sd 23·63) pmol/l, P<0·001), homoeostatic model of assessment for insulin resistance (-1·01 (sd 1·61) v. +0·55 (sd 1·20), P<0·001) and a significant increase in quantitative insulin sensitivity check index (QUICKI) (+0·007 (sd 0·03) v. -0·01 (sd 0·01), P=0·007). In addition, Se supplementation significantly decreased LDL-cholesterol (-0·23 (sd 0·29) v. -0·04 (sd 0·28) mmol/l, P=0·03) and total-:HDL-cholesterol ratio (-0·47 (sd 0·31) v. -0·06 (sd 0·42), P<0·001), and significantly increased HDL-cholesterol levels (+0·18 (sd 0·19) v. +0·02 (sd 0·13) mmol/l, P=0·001) compared with the placebo. In addition, taking Se supplements was associated with a significant reduction in high-sensitivity C-reactive protein (hs-CRP) (-1880·8 (sd 3437·5) v. +415·3 (sd 2116·5) ng/ml, P=0·01), and a significant elevation in plasma total antioxidant capacity (TAC) (+30·9 (sd 118·0) v. -187·9 (sd 412·7) mmol/l, P=0·004) and total glutathione levels (+33·7 (sd 130·4) v. -39·2 (sd 132·8) µmol/l, P=0·003) compared with the placebo. When we applied Bonferroni correction for multiple outcome testing, QUICKI (P=0·11), LDL-cholesterol (P=0·51), hs-CRP (P=0·17), TAC (P=0·06) and GSH (P=0·05) became non-significant, and other metabolic profiles did not alter. Overall, our study supported that Se supplementation for 12 weeks to patients with CHF had beneficial effects on insulin metabolism and few markers of cardio-metabolic risk.

Famous landmark identification in amnestic mild cognitive impairment and Alzheimer's disease.

PubMed

Sheardova, Katerina; Laczó, Jan; Vyhnalek, Martin; Andel, Ross; Mokrisova, Ivana; Vlcek, Kamil; Amlerova, Jana; Hort, Jakub

2014-01-01

Identification of famous landmarks (FLI), famous faces (FFI) and recognition of facial emotions (FER) is affected early in the course of Alzheimer's disease (AD). FFI, FER and FLI may represent domain specific tasks relying on activation of distinct regions of the medial temporal lobe, which are affected successively during the course of AD. However, the data on FFI and FER in MCI are controversial and FLI domain remains almost unexplored. To determine whether and how are these three specific domains impaired in head to head comparison of patients with amnestic MCI (aMCI) single domain (SD-aMCI) and multiple domain (MD-aMCI). We propose that FLI might be most reliable in differentiating SD-aMCI, which is considered to be an earlier stage of AD pathology spread out, from the controls. A total of 114 patients, 13 with single domain (SD-aMCI) and 30 with multiple domains (MD-aMCI), 29 with mild AD and 42 controls underwent standard neurological and neuropsychological evaluations as well as tests of FLI, FER and FFI. Compared to the control group, AD subjects performed worse on FFI (p = 0.020), FER (p<0.001) and FLI (p<0.001), MD-aMCI group had significantly worse scores only on FLI (p = 0.002) and approached statistical significance on FER (0.053). SD-aMCI group performed significantly worse only on FLI (p = 0.028) compared to controls. Patients with SD-aMCI had an isolated impairment restricted to FLI, while patients with MD-aMCI showed impairment in FLI as well as in FER. Patients with mild dementia due to AD have more extensive impairment of higher visual perception. The results suggest that FLI testing may contribute to identification of patients at risk of AD. We hypothesize that clinical examination of all three domains might reflect the spread of the disease from transentorhinal cortex, over amygdala to fusiform gyrus.

Subgrade characterization for highway pavement design.

DOT National Transportation Integrated Search

2000-12-01

Subgrade soil characterization expressed in terms of Resilient Modulus (MR) has become crucial for pavement design. For a new design, MR : values are generally obtained by conducting repeated triaxial tests on reconstituted/undisturbed cylindrical sp...

Triaxial- and uniaxial-compression testing methods developed for extraction of pore water from unsaturated tuff, Yucca Mountain, Nevada

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

Mower, T.E.; Higgins, J.D.; Yang, I.C.

1989-12-31

To support the study of hydrologic system in the unsaturated zone at Yucca Mountain, Nevada, two extraction methods were examined to obtain representative, uncontaminated pore-water samples from unsaturated tuff. Results indicate that triaxial compression, which uses a standard cell, can remove pore water from nonwelded tuff that has an initial moisture content greater than 11% by weight; uniaxial compression, which uses a specifically fabricated cell, can extract pore water from nonwelded tuff that has an initial moisture content greater than 8% and from welded tuff that has an initial moisture content greater than 6.5%. For the ambient moisture conditions ofmore » Yucca Mountain tuffs, uniaxial compression is the most efficient method of pore-water extraction. 12 refs., 7 figs., 2 tabs.« less

Experimental Observations of Localization Phenomena in Sands: Plane Strain Versus Triaxial Compression Conditions

NASA Technical Reports Server (NTRS)

Alshibli, Khalid A.; Batiste, Susan N.; Sture, Stein; Curreri, Peter A. (Technical Monitor)

2002-01-01

A comprehensive experimental investigation was conducted to investigate the effects of loading condition and confining pressure on strength properties and instability phenomena in sands. A uniform sub-rounded to rounded natural silica sand known as F-75 Ottawa sand was used in the investigation. The results of a series on Conventional Triaxial Compression (CTC) experiments tested under very low confining pressures (0.05 - 1.30) kPa tested in a Microgravity environment abroad the NASA Space Shuttle are presented in addition to the results similar specimens tested in terrestrial laboratory to investigate the effect of confining pressure on the constitutive behavior of sands. The behavior of the CTC experiments is compared with the results of Plane Strain (PS) experiments. Computed tomography and other digital imaging techniques were used to study the development and evolution of shear bands.

Triaxial thermopile array geo-heat-flow sensor

DOEpatents

Carrigan, Charles R.; Hardee, Harry C.; Reynolds, Gerald D.; Steinfort, Terry D.

1992-01-01

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.

Shape coexistence and the role of axial asymmetry in 72Ge

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

Ayangeakaa, A. D.; Janssens, R. F.; Wu, C. Y.

2016-01-22

The quadrupole collectivity of low-lying states and the anomalous behavior of the0 + 2 and 2 + 3 levels in 72Ge are investigated via projectile multi-step Coulomb excitation with GRETINA and CHICO-2. A total of forty six E2 and M1 matrix elements connecting fourteen low-lying levels were determined using the least-squares search code, GOSIA. Evidence for triaxiality and shape coexistence, based on the model-independent shape invariants deduced from the Kumar–Cline sum rule, is presented. Moreover, these are interpreted using a simple two-state mixing model as well as multi-state mixing calculations carried out within the framework of the triaxial rotor model.more » Our results represent a significant milestone towards the understanding of the unusual structure of this nucleus.« less

Triaxial instabilities in rapidly rotating neutron stars

NASA Astrophysics Data System (ADS)

Basak, Arkadip

2018-06-01

Viscosity driven bar mode secular instabilities of rapidly rotating neutron stars are studied using LORENE/Nrotstar code. These instabilities set a more rigorous limit to the rotation frequency of a neutron star than the Kepler frequency/mass-shedding limit. The procedure employed in the code comprises of perturbing an axisymmetric and stationary configuration of a neutron star and studying its evolution by constructing a series of triaxial quasi-equilibrium configurations. Symmetry breaking point was found out for Polytropic as well as 10 realistic equations of states (EOS) from the CompOSE data base. The concept of piecewise polytropic EOSs has been used to comprehend the rotational instability of Realistic EOSs and validated with 19 different Realistic EOSs from CompOSE. The possibility of detecting quasi-periodic gravitational waves from viscosity driven instability with ground-based LIGO/VIRGO interferometers is also discussed very briefly.

Constitutive Behavior and Finite Element Analysis of FRP Composite and Concrete Members

PubMed Central

Ann, Ki Yong; Cho, Chang-Geun

2013-01-01

The present study concerns compressive and flexural constitutive models incorporated into an isoparametric beam finite element scheme for fiber reinforced polymer (FRP) and concrete composites, using their multi-axial constitutive behavior. The constitutive behavior of concrete was treated in triaxial stress states as an orthotropic hypoelasticity-based formulation to determine the confinement effect of concrete from a three-dimensional failure surface in triaxial stress states. The constitutive behavior of the FRP composite was formulated from the two-dimensional classical lamination theory. To predict the flexural behavior of circular cross-section with FRP sheet and concrete composite, a layered discretization of cross-sections was incorporated into nonlinear isoparametric beam finite elements. The predicted constitutive behavior was validated by a comparison to available experimental results in the compressive and flexural beam loading test. PMID:28788312

Mechanical and hydraulic properties of Nankai accretionary prism sediments: Effect of stress path

NASA Astrophysics Data System (ADS)

Kitajima, Hiroko; Chester, Frederick M.; Biscontin, Giovanna

2012-10-01

We have conducted triaxial deformation experiments along different loading paths on prism sediments from the Nankai Trough. Different load paths of isotropic loading, uniaxial strain loading, triaxial compression (at constant confining pressure, Pc), undrained Pc reduction, drained Pc reduction, and triaxial unloading at constant Pc, were used to understand the evolution of mechanical and hydraulic properties under complicated stress states and loading histories in accretionary subduction zones. Five deformation experiments were conducted on three sediment core samples for the Nankai prism, specifically from older accreted sediments at the forearc basin, underthrust slope sediments beneath the megasplay fault, and overthrust Upper Shikoku Basin sediments along the frontal thrust. Yield envelopes for each sample were constructed based on the stress paths of Pc-reduction using the modified Cam-clay model, and in situ stress states of the prism were constrained using the results from the other load paths and accounting for horizontal stress. Results suggest that the sediments in the vicinity of the megasplay fault and frontal thrust are highly overconsolidated, and thus likely to deform brittle rather than ductile. The porosity of sediments decreases as the yield envelope expands, while the reduction in permeability mainly depends on the effective mean stress before yield, and the differential stress after yield. An improved understanding of sediment yield strength and hydromechanical properties along different load paths is necessary to treat accurately the coupling of deformation and fluid flow in accretionary subduction zones.

The intrinsic three-dimensional shape of galactic bars

NASA Astrophysics Data System (ADS)

Méndez-Abreu, J.; Costantin, L.; Aguerri, J. A. L.; de Lorenzo-Cáceres, A.; Corsini, E. M.

2018-06-01

We present the first statistical study on the intrinsic three-dimensional (3D) shape of a sample of 83 galactic bars extracted from the CALIFA survey. We use the galaXYZ code to derive the bar intrinsic shape with a statistical approach. The method uses only the geometric information (ellipticities and position angles) of bars and discs obtained from a multi-component photometric decomposition of the galaxy surface-brightness distributions. We find that bars are predominantly prolate-triaxial ellipsoids (68%), with a small fraction of oblate-triaxial ellipsoids (32%). The typical flattening (intrinsic C/A semiaxis ratio) of the bars in our sample is 0.34, which matches well the typical intrinsic flattening of stellar discs at these galaxy masses. We demonstrate that, for prolate-triaxial bars, the intrinsic shape of bars depends on the galaxy Hubble type and stellar mass (bars in massive S0 galaxies are thicker and more circular than those in less massive spirals). The bar intrinsic shape correlates with bulge, disc, and bar parameters. In particular with the bulge-to-total (B/T) luminosity ratio, disc g - r color, and central surface brightness of the bar, confirming the tight link between bars and their host galaxies. Combining the probability distributions of the intrinsic shape of bulges and bars in our sample we show that 52% (16%) of bulges are thicker (flatter) than the surrounding bar at 1σ level. We suggest that these percentages might be representative of the fraction of classical and disc-like bulges in our sample, respectively.

Characterization and Analysis of Triaxially Braided Polymer Composites under Static and Impact Loads

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Roberts, Gary D.; Blinzler, Brina J.; Kohlman, Lee W.; Binienda, Wieslaw K.

2012-01-01

In order to design impact resistant aerospace components made of triaxially-braided polymer matrix composite materials, a need exists to have reliable impact simulation methods and a detailed understanding of the material behavior. Traditional test methods and specimen designs have yielded unrealistic material property data due to material mechanisms such as edge damage. To overcome these deficiencies, various alternative testing geometries such as notched flat coupons have been examined to alleviate difficulties observed with standard test methods. The results from the coupon level tests have been used to characterize and validate a macro level finite element-based model which can be used to simulate the mechanical and impact response of the braided composites. In the analytical model, the triaxial braid unit cell is approximated by using four parallel laminated composites, each with a different fiber layup, which roughly simulates the braid architecture. In the analysis, each of these laminated composites is modeled as a shell element. Currently, each shell element is considered to be a smeared homogeneous material. Simplified micromechanics techniques and lamination theory are used to determine the equivalent stiffness properties of each shell element, and results from the coupon level tests on the braided composite are used to back out the strength properties of each shell element. Recent improvements to the model include the incorporation of strain rate effects into the model. Simulations of ballistic impact tests have been carried out to investigate and verify the analysis approach.

Effect of open hole on tensile failure properties of 2D triaxial braided textile composites and tape equivalents

NASA Technical Reports Server (NTRS)

Norman, Timothy L.; Anglin, Colin; Gaskin, David; Patrick, Mike

1995-01-01

The unnotched and notched (open hole) tensile strength and failure mechanisms of two-dimensional (2D) triaxial braided composites were examined. The effect of notch size and notch position were investigated. Damage initiation and propagation in notched and unnotched coupons were also examined. Theory developed to predict the normal stress distribution near an open hole and failure for tape laminated composites was evaluated for its applicability to triaxial braided textile composite materials. Four fiber architectures were considered with different combinations of braid angle, longitudinal and braider yam size, and percentage of longitudinal yarns. Tape laminates equivalent to textile composites were also constructed for comparison. Unnotched tape equivalents were stronger than braided textiles but exhibited greater notch sensitivity. Notched textiles and tape equivalents have roughly the same strength at large notch sizes. Two common damage mechanisms were found: braider yams cracking and near notch longitudinal yarn splitting. Cracking was found to initiate in braider yarns in unnotched and notched coupons, and propagate in the direction of the braider yarns until failure. Longitudinal yarn splitting occurred in three of four architectures that were longitudinally fiber dominated. Damage initiation stress decreased with increasing braid angle. No significant differences in prediction of near notch stress between measured and predicted stress were weak for textiles with large braid angle. Notch strength could not be predicted using existing anisotropic theory for braided textiles due to their insensitivity to notch.

Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults

PubMed Central

Verschueren, Sabine M. P.; Degens, Hans; Morse, Christopher I.; Onambélé, Gladys L.

2017-01-01

Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing. To date, accelerometers using cut-off point models are most preferred for this, however, machine learning seems a highly promising future alternative. Hence, the current study compared between cut-off point and machine learning algorithms, for optimal quantification of sedentary behaviour and physical activity intensities in the elderly. Thus, in a heterogeneous sample of forty participants (aged ≥60 years, 50% female) energy expenditure during laboratory-based activities (ranging from sedentary behaviour through to moderate-to-vigorous physical activity) was estimated by indirect calorimetry, whilst wearing triaxial thigh-mounted accelerometers. Three cut-off point algorithms and a Random Forest machine learning model were developed and cross-validated using the collected data. Detailed analyses were performed to check algorithm robustness, and examine and benchmark both overall and participant-specific balanced accuracies. This revealed that the four models can at least be used to confidently monitor sedentary behaviour and moderate-to-vigorous physical activity. Nevertheless, the machine learning algorithm outperformed the cut-off point models by being robust for all individual’s physiological and non-physiological characteristics and showing more performance of an acceptable level over the whole range of physical activity intensities. Therefore, we propose that Random Forest machine learning may be optimal for objective assessment of sedentary behaviour and physical activity in older adults using thigh-mounted triaxial accelerometry. PMID:29155839

Time dependent voiding mechanisms in polyamide 6 submitted to high stress triaxiality: experimental characterisation and finite element modelling

NASA Astrophysics Data System (ADS)

Selles, Nathan; King, Andrew; Proudhon, Henry; Saintier, Nicolas; Laiarinandrasana, Lucien

2017-08-01

Double notched round bars made of semi-crystalline polymer polyamide 6 (PA6) were submitted to monotonic tensile and creep tests. The two notches had a root radius of 0.45 mm, which imposes a multiaxial stress state and a state of high triaxiality in the net (minimal) section of the specimens. Tests were carried out until the failure occurred from one of the notches. The other one, unbroken but deformed under steady strain rate or steady load, was inspected using the Synchrotron Radiation Computed Tomography (SRCT) technique. These 3D through thickness inspections allowed the study of microstructural evolution at the peak stress for the monotonic tensile test and at the beginning of the tertiary creep for the creep tests. Cavitation features were assessed with a micrometre resolution within the notched region. Spatial distributions of void volume fraction ( Vf) and void morphology were studied. Voiding mechanisms were similar under steady strain rates and steady loads. The maximum values of Vf were located between the axis of revolution of the specimens and the notch surface and voids were considered as flat cylinders with a circular basis perpendicular to the loading direction. A model, based on porous plasticity, was used to simulate the mechanical response of this PA6 material under high stress triaxiality. Both macroscopic behaviour (loading curves) and voiding micro-mechanisms (radial distributions of void volume fraction) were accurately predicted using finite element simulations.

Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults.

PubMed

Wullems, Jorgen A; Verschueren, Sabine M P; Degens, Hans; Morse, Christopher I; Onambélé, Gladys L

2017-01-01

Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing. To date, accelerometers using cut-off point models are most preferred for this, however, machine learning seems a highly promising future alternative. Hence, the current study compared between cut-off point and machine learning algorithms, for optimal quantification of sedentary behaviour and physical activity intensities in the elderly. Thus, in a heterogeneous sample of forty participants (aged ≥60 years, 50% female) energy expenditure during laboratory-based activities (ranging from sedentary behaviour through to moderate-to-vigorous physical activity) was estimated by indirect calorimetry, whilst wearing triaxial thigh-mounted accelerometers. Three cut-off point algorithms and a Random Forest machine learning model were developed and cross-validated using the collected data. Detailed analyses were performed to check algorithm robustness, and examine and benchmark both overall and participant-specific balanced accuracies. This revealed that the four models can at least be used to confidently monitor sedentary behaviour and moderate-to-vigorous physical activity. Nevertheless, the machine learning algorithm outperformed the cut-off point models by being robust for all individual's physiological and non-physiological characteristics and showing more performance of an acceptable level over the whole range of physical activity intensities. Therefore, we propose that Random Forest machine learning may be optimal for objective assessment of sedentary behaviour and physical activity in older adults using thigh-mounted triaxial accelerometry.

The magnification of structural anomalies with Grodzins systematic in the framework of Asymmetric Rotor Model

NASA Astrophysics Data System (ADS)

Bindra, Amit; Mittal, H. M.

2018-07-01

The dependence of Grodzins systematic as shape fluctuation energy product ESF * B (E 2) ↑ and rotational energy product EROT * B (E 2) ↑ on the Asymmetry parameter γ0 is carried out in the Z = 50-82, N = 82-126 major shell space. The Asymmetry parameter γ0, varying from 0° to 60°, reflects the change in nuclear structure from prolate to oblate. Strong anomalies are highlighted in the shape transitional isotopes. The product ESF * B (E 2) ↑ evolves from low negative values for vibrator nuclei, passing close to zero and then substantially increasing towards triaxial rotor limit with γ0 ∼ 30 °. However, the product EROT * B (E 2) ↑ decreases as a function of γ0 for all the nuclei approaching towards triaxiality from Z = 50-82, N = 82-126. Anomalies are also noticed for the N > 104 region where the product EROT * B (E 2) ↑ decreases in zigzag phase for 188-196Pt isotopes corresponding to γ0 ∼ 25- 30 ° and this reflects the breakdown of coherence between rotational energy EROT and excitation strength B (E 2) ↑. The product EROT * B (E 2) ↑ indicates the shape phase transition for Pt isotopic chain from spherical to γ - soft to slightly triaxial. We have studied for the first time the role of Grodzins systematic ESF and EROT in the framework of Asymmetric Rotor Model.

Characterization of Damage in Triaxial Braid Composites Under Tensile Loading

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Binienda, Wieslaw K.; Roberts, Gary D.; Goldberg, Robert K.

2009-01-01

Carbon fiber composites utilizing flattened, large tow yarns in woven or braided forms are being used in many aerospace applications. Their complex fiber architecture and large unit cell size present challenges in both understanding deformation processes and measuring reliable material properties. This report examines composites made using flattened 12k and 24k standard modulus carbon fiber yarns in a 0 /+60 /-60 triaxial braid architecture. Standard straight-sided tensile coupons are tested with the 0 axial braid fibers either parallel with or perpendicular to the applied tensile load (axial or transverse tensile test, respectively). Nonuniform surface strain resulting from the triaxial braid architecture is examined using photogrammetry. Local regions of high strain concentration are examined to identify where failure initiates and to determine the local strain at the time of initiation. Splitting within fiber bundles is the first failure mode observed at low to intermediate strains. For axial tensile tests splitting is primarily in the 60 bias fibers, which were oriented 60 to the applied load. At higher strains, out-of-plane deformation associated with localized delamination between fiber bundles or damage within fiber bundles is observed. For transverse tensile tests, the splitting is primarily in the 0 axial fibers, which were oriented transverse to the applied load. The initiation and accumulation of local damage causes the global transverse stress-strain curves to become nonlinear and causes failure to occur at a reduced ultimate strain. Extensive delamination at the specimen edges is also observed.

New Global Calculation of Nuclear Masses and Fission Barriers for Astrophysical Applications

NASA Astrophysics Data System (ADS)

Möller, P.; Sierk, A. J.; Bengtsson, R.; Ichikawa, T.; Iwamoto, A.

2008-05-01

The FRDM(1992) mass model [1] has an accuracy of 0.669 MeV in the region where its parameters were determined. For the 529 masses that have been measured since, its accuracy is 0.46 MeV, which is encouraging for applications far from stability in astrophysics. We are developing an improved mass model, the FRDM(2008). The improvements in the calculations with respect to the FRDM(1992) are in two main areas. (1) The macroscopic model parameters are better optimized. By simulation (adjusting to a limited set of now known nuclei) we can show that this actually makes the results more reliable in new regions of nuclei. (2) The ground-state deformation parameters are more accurately calculated. We minimize the energy in a four-dimensional deformation space (ɛ2, V3, V4, V6,) using a grid interval of 0.01 in all 4 deformation variables. The (non-finalized) FRDM (2008-a) has an accuracy of 0.596 MeV with respect to the 2003 Audi mass evaluation before triaxial shape degrees of freedom are included (in progress). When triaxiality effects are incorporated preliminary results indicate that the model accuracy will improve further, to about 0.586 MeV. We also discuss very large-scale fission-barrier calculations in the related FRLDM (2002) model, which has been shown to reproduce very satisfactorily known fission properties, for example barrier heights from 70Se to the heaviest elements, multiple fission modes in the Ra region, asymmetry of mass division in fission and the triple-humped structure found in light actinides. In the superheavy region we find barriers consistent with the observed half-lives. We have completed production calculations and obtain barrier heights for 5254 nuclei heavier than A = 170 for all nuclei between the proton and neutron drip lines. The energy is calculated for 5009325 different shapes for each nucleus and the optimum barrier between ground state and separated fragments is determined by use of an ``immersion'' technique.

Methodologic quality of meta-analyses and systematic reviews on the Mediterranean diet and cardiovascular disease outcomes: a review.

PubMed

Huedo-Medina, Tania B; Garcia, Marissa; Bihuniak, Jessica D; Kenny, Anne; Kerstetter, Jane

2016-03-01

Several systematic reviews/meta-analyses published within the past 10 y have examined the associations of Mediterranean-style diets (MedSDs) on cardiovascular disease (CVD) risk. However, these reviews have not been evaluated for satisfying contemporary methodologic quality standards. This study evaluated the quality of recent systematic reviews/meta-analyses on MedSD and CVD risk outcomes by using an established methodologic quality scale. The relation between review quality and impact per publication value of the journal in which the article had been published was also evaluated. To assess compliance with current standards, we applied a modified version of the Assessment of Multiple Systematic Reviews (AMSTARMedSD) quality scale to systematic reviews/meta-analyses retrieved from electronic databases that had met our selection criteria: 1) used systematic or meta-analytic procedures to review the literature, 2) examined MedSD trials, and 3) had MedSD interventions independently or combined with other interventions. Reviews completely satisfied from 8% to 75% of the AMSTARMedSD items (mean ± SD: 31.2% ± 19.4%), with those published in higher-impact journals having greater quality scores. At a minimum, 60% of the 24 reviews did not disclose full search details or apply appropriate statistical methods to combine study findings. Only 5 of the reviews included participant or study characteristics in their analyses, and none evaluated MedSD diet characteristics. These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on CVD risk do not fully comply with contemporary methodologic quality standards. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects CVD risk or how these effects may be modified by the participant or MedSD characteristics. To clarify the associations between MedSD and CVD risk, future meta-analyses and systematic reviews should not only follow methodologic quality standards but also include more statistical modeling results when data allow. © 2016 American Society for Nutrition.

Comparison of major depressive disorder and subthreshold depression among older adults in community long-term care.

PubMed

Lee, Mi Jin; Hasche, Leslie K; Choi, Sunha; Proctor, Enola K; Morrow-Howell, Nancy

2013-01-01

This study extends existing knowledge regarding the continuum between major depression (MD) and subthreshold depression (SD) by examining differences in symptomology and associative factors for a subpopulation of older adults with functional disability. Our sample consisted of clients age 60 and above entering public community long term care derived from the baseline survey of a longitudinal study (315 non-depressed, 74 MD, and 221 SD). We used the Diagnostic Interview Schedule to establish diagnoses of MD, the Center for Epidemiological Studies Depression Scale (CES-D) to assess SD, and other self-report measures to explore potential associative factors of demographics, comorbidity, social support, and stressors. No differences in CES-D identified symptoms occurred between the two groups. MD and SD were both associated with lower education, poorer social support, more severe medical conditions, and higher stress when compared to non-depressed older adults. Younger age and being female were associated solely with MD; whereas, worse perceived health and more trouble affording food were associated solely with SD. The only associative factor significantly different between MD and SD was age. Those with MD were more likely to be younger than those with SD. Our findings of symptom profiles and associative factors lend support to the continuum notion of depression. Identification of only older adults within the community long-term care service system who meet criteria for MD would leave many older adults, who also face multiple comorbidities, high levels of stress and social isolation, and substantial depressive symptoms undiagnosed and untreated.

Brain networks governing the golf swing in professional golfers.

PubMed

Kim, Jin Hyun; Han, Joung Kyue; Kim, Bung-Nyun; Han, Doug Hyun

2015-01-01

Golf, as with most complex motor skills, requires multiple different brain functions, including attention, motor planning, coordination, calculation of timing, and emotional control. In this study we assessed the correlation between swing components and brain connectivity from the cerebellum to the cerebrum. Ten female golf players and 10 age-matched female controls were recruited. In order to determine swing consistency among participants, the standard deviation (SD) of the mean swing speed time and the SD of the mean swing angle were assessed over 30 swings. Functional brain connectivity was assessed by resting state functional MRI. Pro-golfers showed greater positive left cerebellum connectivity to the occipital lobe, temporal lobe, parietal lobe and both frontal lobes compared to controls. The SD of play scores was positively correlated with the SD of the impact angle. Constant swing speed and back swing angle in professional golfers were associated with functional connectivity (FC) between the cerebellum and parietal and frontal lobes. In addition, the constant impact angle in professional golfers was associated with improved golf scores and additional FC of the thalamus.

CROSS-NATIONAL APPLICABILITY OF A PARSIMONIOUS MEASURE OF ACCULTURATION TO GLOBAL CONSUMER CULTURE.

PubMed

Durvasula, Srinivas; Lysonski, Steven

2015-06-01

Cleveland and Laroche presented a scale to measure Acculturation to Global Consumer Culture. This measure was the first attempt to gauge consumer mindsets regarding their adaptation to global consumerism. Because this scale consisted of 57 scale items, applying such a lengthy scale can lead to response fatigue. Past research has also suggested that as more items are added to a scale, the informational value of each additional item is marginal. As an alternative, a shorter version of the Acculturation to Global Consumer Culture Scale is presented. The psychometric properties of this scale were verified via multiple group confirmatory factor analysis. A four-country investigation of young adults in China (n = 126; M age = 22.24 yr., SD = 3.63), New Zealand (n = 196; M age = 20.12 yr., SD = 4.12), Nigeria (n = 146; M age = 23.09 yr., SD = 3.80), and the United States (n = 120; M age = 21.67 yr., SD = 4.26) provides support for the cross-national applicability of the proposed parsimonious measure. Limitations and extensions are discussed.

Prediction of resilient modulus from soil index properties.

DOT National Transportation Integrated Search

2004-11-01

Subgrade soil characterization in terms of Resilient Modulus (MR) has become crucial for pavement design. For a new : design, MR values are generally obtained by conducting repeated load triaxial tests on reconstituted/undisturbed cylindrical : speci...

Prediction of resilient modulus from soil index properties

DOT National Transportation Integrated Search

2004-11-01

Subgrade soil characterization in terms of Resilient Modulus (MR) has become crucial for pavement design. For a new design, MR values are generally obtained by conducting repeated load triaxial tests on reconstituted/undisturbed cylindrical specimens...

Falling weight deflectometer for estimating subgrade resilient moduli.

DOT National Transportation Integrated Search

2003-12-01

Subgrade soil characterization expressed in terms of resilient modulus, MR, has become crucial for pavement design. For : new pavement design, MR values are generally obtained by conducting repeated load triaxial tests on reconstituted/undisturbed : ...

Robustness of linkage strategy that leads to large-scale cooperation.

PubMed

Inaba, Misato; Takahashi, Nobuyuki; Ohtsuki, Hisashi

2016-11-21

One of the most well-known models to characterize cooperation among unrelated individuals is Social dilemma (SD). However there is no consensus about how to solve the SD by itself. Since SDs are often embedded in other social interactions, including indirect reciprocity games (IR), human can coordinate their behaviors across multiple games. Such coordination is called 'linkage'. Recently linkage has been considered as a promising solution to resolve SDs, since excluding SD defectors (i.e. those who defected in SD) from indirectly reciprocal relationships functions as a costless sanction. A previous study performed mathematical modeling and revealed that a linkage strategy, which cooperates in SD and engages in the Standing strategy in IR based on the recipients' behaviors in both SD and IR, was an ESS against a non-linkage strategy which defects in SD and engages in the Standing strategy in IR based on recipients' behaviors only in IR (Panchanathan and Boyd, 2004). In order to investigate the robustness of the linkage strategy, we devised a non-linkage strategy, which cooperates in SD but does not link two games. First, we conducted a mathematical analysis and demonstrated that the linkage strategy was not an ESS against cooperating non-linkage strategy. Second, we conducted a series of agent-based computer simulations to examine how the strategies perform in situations in which various types of errors can occur. Our results showed that the linkage strategy was an ESS only when there are implementation errors in SD. However, the equilibrium of the linkage strategy was unstable when there are perception errors. Since we know that humans are not free from perception errors in their social life, future studies will need to show how perception errors can be overcome in order to provide support for the conclusion that linkage is a plausible solution to SDs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Restorative effects of curcumin on sleep-deprivation induced memory impairments and structural changes of the hippocampus in a rat model.

PubMed

Noorafshan, Ali; Karimi, Fatemeh; Kamali, Ali-Mohammad; Karbalay-Doust, Saied; Nami, Mohammad

2017-11-15

The present study examined the consequences of rapid eye-movement sleep-deprivation (REM-SD) with or without curcumin treatment. The outcome measures comprised quantitative features in the three-dimensional reconstruction (3DR) CA1 and dentate gyrus in experimental and control animals using stereological procedures. Male rats were arbitrarily assigned to nine groups based on the intervention and treatment administered including: 1-cage control+distilled water, 2-cage control+curcumin (100mg/kg/day), 3-cage control+olive oil, 4-REM-SD+distilled water, 5-REM-SD+curcumin, 6-REM-SD+olive oil, 7-grid-floor control+distilled water, 8-grid-floor control+curcumin, and 9-grid-floor control+olive oil. Animals in the latter three groups were placed on wire-mesh grids in the sleep-deprivation box. REM-SD was induced by an apparatus comprising a water tank and multiple platforms. After a period of 21days, rats were submitted to the novel object-recognition task. Later, their brains were excised and evaluated using stereological methods. Our results indicated a respective 29% and 31% reduction in the total volume of CA1, and dentate gyrus in REM-SD+distilled water group as compared to the grid-floor control+distilled water group (p<0.05). Other than the above, the overall number of the pyramidal cells of CA1 and granular cells of dentate gyrus in the sleep-deprived group were found to be reduced by 48% and 25%, respectively. The REM-SD+distilled water group also exhibited impaired object recognition memory and deformed three-dimensional reconstructions of these regions. The volume, cell number, reconstruction, object recognition time, and body weight were however recovered in the REM-SD+curcumin compared to the REM-SD+distilled water group. This suggests the potential neuro-restorative effects of curcumin in our model. Copyright © 2017 Elsevier Inc. All rights reserved.

Therapeutic potency of saponin rich aqueous extract of Scoparia dulcis L. in alloxan induced diabetes in rats.

PubMed

Perumal, P Saravana; Anaswara, P V; Muthuraman, A; Krishan, S

2014-04-01

Diabetes mellitus is major metabolic disorders of carbohydrate metabolism. This leads to alter the multiple organ system. To investigate the antidiabetic and antioxidant effects of the saponin rich aqueous extract of Scoparia dulcis (SRE-SD) using alloxan-induced hyperglycemic rat model. The single dose of alloxan was injected for the induction of diabetes in rats. The SRE-SD and glibenclamide were administered for 15 consecutive days from the 3(rd) day of alloxan administration. Quantity of food and water intake was measured at day 0, and 18. Further, body weight was recorded and blood samples were collected at different time intervals that is, day 0, 3, 8, 13, and 18. The oxidative biomarkers (i.e. thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and nitrite (NO(2-)) levels were also estimated in the serum sample. The SRE-SD showed a remarkable dose and time-dependent changes in alloxan-induced rise in the level of food consumption and water intake, serum glucose level, TBARS, NO(2-) and fall in the level of GSH. Further, significant attenuation was observed at 20 and 30 mg/kg of SRE-SD treated group. These findings demonstrate that SRE-SD has both antidiabetic and antioxidant effects on the experimental model of diabetes in rat.

Multiple co morbid conditions in patient with Mast Cell Activation Syndrome

DTIC Science & Technology

2017-10-26

conditions in patient \\\\·ith Mast Cell Activation Syndron1e Sb. GRANT NUMBER Sc. PROGRAM.ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER Maj Sofia...13. SUPPLEMENTARY NOTES 14. ABSTRACT Multiple co-n1orhid conditions in patient \\Vith Mast Cell Activation Syndrotne Sofia M. Szari.MD. and James...Defense. !NTR()D{JCT!ON: Mast cell activation disorders {MCAD) have been associated \\Vilh Connective Tissue Disorders (CTD) and orthostatic

Experimental and Analytical Characterization of the Macromechanical Response for Triaxial Braided Composite Materials

NASA Technical Reports Server (NTRS)

Littell, Justin D.

2013-01-01

Increasingly, carbon composite structures are being used in aerospace applications. Their highstrength, high-stiffness, and low-weight properties make them good candidates for replacing many aerospace structures currently made of aluminum or steel. Recently, many of the aircraft engine manufacturers have developed new commercial jet engines that will use composite fan cases. Instead of using traditional composite layup techniques, these new fan cases will use a triaxially braided pattern, which improves case performance. The impact characteristics of composite materials for jet engine fan case applications have been an important research topic because Federal regulations require that an engine case be able to contain a blade and blade fragments during an engine blade-out event. Once the impact characteristics of these triaxial braided materials become known, computer models can be developed to simulate a jet engine blade-out event, thus reducing cost and time in the development of these composite jet engine cases. The two main problems that have arisen in this area of research are that the properties for these materials have not been fully determined and computationally efficient computer models, which incorporate much of the microscale deformation and failure mechanisms, are not available. The research reported herein addresses some of the deficiencies present in previous research regarding these triaxial braided composite materials. The current research develops new techniques to accurately quantify the material properties of the triaxial braided composite materials. New test methods are developed for the polymer resin composite constituent and representative composite coupons. These methods expand previous research by using novel specimen designs along with using a noncontact measuring system that is also capable of identifying and quantifying many of the microscale failure mechanisms present in the materials. Finally, using the data gathered, a new hybrid micromacromechanical computer model is created to simulate the behavior of these composite material systems under static and ballistic impact loading using the test data acquired. The model also quantifies the way in which the fiber/matrix interface affects material response under static and impact loading. The results show that the test methods are capable of accurately quantifying the polymer resin under a variety of strain rates and temperature for three loading conditions. The resin strength and stiffness data show a clear rate and temperature dependence. The data also show the hydrostatic stress effects and hysteresis, all of which can be used by researchers developing composite constitutive models for the resins. The results for the composite data reveal noticeable differences in strength, failure strain, and stiffness in the different material systems presented. The investigations into the microscale failure mechanisms provide information about the nature of the different material system behaviors. Finally, the developed computer model predicts composite static strength and stiffness to within 10 percent of the gathered test data and also agrees with composite impact data, where available.

Characteristics of dynamic triaxial testing of asphalt mixtures

NASA Astrophysics Data System (ADS)

Ulloa Calderon, Alvaro

Due to the increasing traffic loads and tire pressures, a serious detrimental impact has occurred on flexible pavements in the form of excessive permanent deformation once the critical combination of loading and environmental conditions are reached. This distress, also known as rutting, leads to an increase in road roughness and ultimately jeopardizes the road users' safety. The flow number (FN) simple performance test for asphalt mixtures was one of the final three tests selected for further evaluation from the twenty-four test/material properties initially examined under the NCHRP 9-19 project. Currently, no standard triaxial testing conditions in terms of the magnitude of the deviator and confining stresses have been specified. In addition, a repeated haversine axial compressive load pulse of 0.1 second and a rest period of 0.9 second are commonly used as part of the triaxial testing conditions. The overall objective of this research was to define the loading conditions that created by a moving truck load in the hot mixed asphalt (HMA) layer. The loading conditions were defined in terms of the triaxial stress levels and the corresponding loading time. Dynamic mechanistic analysis with circular stress distribution was used to closely simulate field loading conditions. Extensive mechanistic analyses of three different asphalt pavement structures subjected to moving traffic loads at various speeds and under braking and non-braking conditions were conducted using the 3D-Move model. Prediction equations for estimating the anticipated deviator and confining stresses along with the equivalent deviator stress pulse duration as a function of pavement temperature, vehicle speed, and asphalt mixture's stiffness have been developed. The magnitude of deviator stress, sigmad and confining stress, sigmac, were determined by converting the stress tensor computed in the HMA layer at 2" below pavement surface under a moving 18-wheel truck using the octahedral normal and shear stresses. In addition, the characteristics of the loading pulse were determined by best-fitting a haversine wave shape for the equivalent triaxial deviator stress pulse. The tandem axle was proven to generate the most critical combination of deviator and confining stresses for braking and non-braking conditions at 2 inches below the pavement surface. Thus, this study is focused on developing the stress state and pulse characteristics required to determine the critical conditions on HMA mixtures under the loading of the tandem axle. An increase of 40% was observed in the deviator stress when braking conditions are incorporated. A preliminary validation of the recommended magnitudes for the deviator and confining stresses on a field mixture from WesTrack showed consistent results between the flow number test results and field performance. Based on laboratory experiments, the critical conditions of different field mixtures from the WesTrack project and also lab produced samples at different air-voids levels were determined. The results indicate that the tertiary stage will occur under the FN test when a combination of a critical temperature and a given loading conditions for specific air voids content occurs.

Intensity Thresholds on Raw Acceleration Data: Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD) Approaches

PubMed Central

Bakrania, Kishan; Yates, Thomas; Rowlands, Alex V.; Esliger, Dale W.; Bunnewell, Sarah; Sanders, James; Davies, Melanie; Khunti, Kamlesh; Edwardson, Charlotte L.

2016-01-01

Objectives (1) To develop and internally-validate Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD) thresholds for separating sedentary behaviours from common light-intensity physical activities using raw acceleration data collected from both hip- and wrist-worn tri-axial accelerometers; and (2) to compare and evaluate the performances between the ENMO and MAD metrics. Methods Thirty-three adults [mean age (standard deviation (SD)) = 27.4 (5.9) years; mean BMI (SD) = 23.9 (3.7) kg/m2; 20 females (60.6%)] wore four accelerometers; an ActiGraph GT3X+ and a GENEActiv on the right hip; and an ActiGraph GT3X+ and a GENEActiv on the non-dominant wrist. Under laboratory-conditions, participants performed 16 different activities (11 sedentary behaviours and 5 light-intensity physical activities) for 5 minutes each. ENMO and MAD were computed from the raw acceleration data, and logistic regression and receiver-operating-characteristic (ROC) analyses were implemented to derive thresholds for activity discrimination. Areas under ROC curves (AUROC) were calculated to summarise performances and thresholds were assessed via executing leave-one-out-cross-validations. Results For both hip and wrist monitor placements, in comparison to the ActiGraph GT3X+ monitors, the ENMO and MAD values derived from the GENEActiv devices were observed to be slightly higher, particularly for the lower-intensity activities. Monitor-specific hip and wrist ENMO and MAD thresholds showed excellent ability for separating sedentary behaviours from motion-based light-intensity physical activities (in general, AUROCs >0.95), with validation indicating robustness. However, poor classification was experienced when attempting to isolate standing still from sedentary behaviours (in general, AUROCs <0.65). The ENMO and MAD metrics tended to perform similarly across activities and accelerometer brands. Conclusions Researchers can utilise these robust monitor-specific hip and wrist ENMO and MAD thresholds, in order to accurately separate sedentary behaviours from common motion-based light-intensity physical activities. However, caution should be taken if isolating sedentary behaviours from standing is of particular interest. PMID:27706241

Intensity Thresholds on Raw Acceleration Data: Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD) Approaches.

PubMed

Bakrania, Kishan; Yates, Thomas; Rowlands, Alex V; Esliger, Dale W; Bunnewell, Sarah; Sanders, James; Davies, Melanie; Khunti, Kamlesh; Edwardson, Charlotte L

2016-01-01

(1) To develop and internally-validate Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD) thresholds for separating sedentary behaviours from common light-intensity physical activities using raw acceleration data collected from both hip- and wrist-worn tri-axial accelerometers; and (2) to compare and evaluate the performances between the ENMO and MAD metrics. Thirty-three adults [mean age (standard deviation (SD)) = 27.4 (5.9) years; mean BMI (SD) = 23.9 (3.7) kg/m2; 20 females (60.6%)] wore four accelerometers; an ActiGraph GT3X+ and a GENEActiv on the right hip; and an ActiGraph GT3X+ and a GENEActiv on the non-dominant wrist. Under laboratory-conditions, participants performed 16 different activities (11 sedentary behaviours and 5 light-intensity physical activities) for 5 minutes each. ENMO and MAD were computed from the raw acceleration data, and logistic regression and receiver-operating-characteristic (ROC) analyses were implemented to derive thresholds for activity discrimination. Areas under ROC curves (AUROC) were calculated to summarise performances and thresholds were assessed via executing leave-one-out-cross-validations. For both hip and wrist monitor placements, in comparison to the ActiGraph GT3X+ monitors, the ENMO and MAD values derived from the GENEActiv devices were observed to be slightly higher, particularly for the lower-intensity activities. Monitor-specific hip and wrist ENMO and MAD thresholds showed excellent ability for separating sedentary behaviours from motion-based light-intensity physical activities (in general, AUROCs >0.95), with validation indicating robustness. However, poor classification was experienced when attempting to isolate standing still from sedentary behaviours (in general, AUROCs <0.65). The ENMO and MAD metrics tended to perform similarly across activities and accelerometer brands. Researchers can utilise these robust monitor-specific hip and wrist ENMO and MAD thresholds, in order to accurately separate sedentary behaviours from common motion-based light-intensity physical activities. However, caution should be taken if isolating sedentary behaviours from standing is of particular interest.

Normal-faulting stress state associated with low differential stress in an overriding plate in northeast Japan prior to the 2011 Mw 9.0 Tohoku earthquake

NASA Astrophysics Data System (ADS)

Otsubo, Makoto; Miyakawa, Ayumu; Imanishi, Kazutoshi

2018-03-01

Spatial and temporal variations in inland crustal stress prior to the 2011 Mw 9.0 Tohoku earthquake are investigated using focal mechanism solutions for shallow seismicity in Iwaki City, Japan. The multiple inverse method of stress tensor inversion detected two normal-faulting stress states that dominate in different regions. The stress field around Iwaki City changed from a NNW-SSE-trending triaxial extensional stress (stress regime A) to a NW-SE-trending axial tension (stress regime B) between 2005 and 2008. These stress changes may be the result of accumulated extensional stress associated with co- and post-seismic deformation due to the M7 class earthquakes. In this study we suggest that the stress state around Iwaki City prior to the 2011 Tohoku earthquake may have been extensional with a low differential stress. High pore pressure is required to cause earthquakes under such small differential stresses.

Single-shot full strain tensor determination with microbeam X-ray Laue diffraction and a two-dimensional energy-dispersive detector.

PubMed

Abboud, A; Kirchlechner, C; Keckes, J; Conka Nurdan, T; Send, S; Micha, J S; Ulrich, O; Hartmann, R; Strüder, L; Pietsch, U

2017-06-01

The full strain and stress tensor determination in a triaxially stressed single crystal using X-ray diffraction requires a series of lattice spacing measurements at different crystal orientations. This can be achieved using a tunable X-ray source. This article reports on a novel experimental procedure for single-shot full strain tensor determination using polychromatic synchrotron radiation with an energy range from 5 to 23 keV. Microbeam X-ray Laue diffraction patterns were collected from a copper micro-bending beam along the central axis (centroid of the cross section). Taking advantage of a two-dimensional energy-dispersive X-ray detector (pnCCD), the position and energy of the collected Laue spots were measured for multiple positions on the sample, allowing the measurement of variations in the local microstructure. At the same time, both the deviatoric and hydrostatic components of the elastic strain and stress tensors were calculated.

Maternal multiple micronutrient supplementation and other biomedical and socioenvironmental influences on children's cognition at age 9-12 years in Indonesia: follow-up of the SUMMIT randomised trial.

PubMed

Prado, Elizabeth L; Sebayang, Susy K; Apriatni, Mandri; Adawiyah, Siti R; Hidayati, Nina; Islamiyah, Ayuniarti; Siddiq, Sudirman; Harefa, Benyamin; Lum, Jarrad; Alcock, Katherine J; Ullman, Michael T; Muadz, Husni; Shankar, Anuraj H

2017-02-01

Brain and cognitive development during the first 1000 days from conception are affected by multiple biomedical and socioenvironmental determinants including nutrition, health, nurturing, and stimulation. An improved understanding of the long-term influence of these factors is needed to prioritise public health investments to optimise human development. We did a follow-up study of the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT), a double-blind, cluster-randomised trial of maternal supplementation with multiple micronutrients (MMN) or iron and folic acid (IFA) in Indonesia. Of 27 356 live infants from birth to 3 months of age in 2001-04, we re-enrolled 19 274 (70%) children at age 9-12 years, and randomly selected 2879 from the 18 230 who were attending school at a known location. Of these, 574 children were oversampled from mothers who were anaemic or malnourished at SUMMIT enrolment. We assessed the effects of MMN and associations of biomedical (ie, maternal and child anthropometry and haemoglobin and preterm birth) and socioenvironmental determinants (ie, parental education, socioeconomic status, home environment, and maternal depression) on general intellectual ability, declarative memory, procedural memory, executive function, academic achievement, fine motor dexterity, and socioemotional health. The SUMMIT trial was registered, number ISRCTN34151616. Children of mothers given MMN had a mean score of 0·11 SD (95% CI 0·01-0·20, p=0·0319) higher in procedural memory than those given IFA, equivalent to the increase in scores with half a year of schooling. Children of anaemic mothers in the MMN group scored 0·18 SD (0·06-0·31, p=0·0047) higher in general intellectual ability, similar to the increase with 1 year of schooling. Overall, 18 of 21 tests showed a positive coefficient of MMN versus IFA (p=0·0431) with effect sizes from 0·00-0·18 SD. In multiple regression models, socioenvironmental determinants had coefficients of 0·00-0·43 SD and 22 of 35 tests were significant at the 95% CI level, whereas biomedical coefficients were 0·00-0·10 SD and eight of 56 tests were significant, indicating larger and more consistent impact of socioenvironmental factors (p<0·0001). Maternal MMN had long-term benefits for child cognitive development at 9-12 years of age, thereby supporting its role in early childhood development, and policy change toward MMN. The stronger association of socioenvironmental determinants with improved cognition suggests present reproductive, maternal, neonatal, and child health programmes focused on biomedical determinants might not sufficiently enhance child cognition, and that programmes addressing socioenvironmental determinants are essential to achieve thriving populations. Grand Challenges Canada Saving Brains Program. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND license. Published by Elsevier Ltd.. All rights reserved.

Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-aided implant placement. Part II: reliability of mucosa-supported stereolithographic guides.

PubMed

Arisan, Volkan; Karabuda, Zihni Cüneyt; Pişkin, Bülent; Özdemir, Tayfun

2013-12-01

Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study. Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05). Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively). Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners. © 2012 Wiley Periodicals, Inc.

The gait standard deviation, a single measure of kinematic variability.

PubMed

Sangeux, Morgan; Passmore, Elyse; Graham, H Kerr; Tirosh, Oren

2016-05-01

Measurement of gait kinematic variability provides relevant clinical information in certain conditions affecting the neuromotor control of movement. In this article, we present a measure of overall gait kinematic variability, GaitSD, based on combination of waveforms' standard deviation. The waveform standard deviation is the common numerator in established indices of variability such as Kadaba's coefficient of multiple correlation or Winter's waveform coefficient of variation. Gait data were collected on typically developing children aged 6-17 years. Large number of strides was captured for each child, average 45 (SD: 11) for kinematics and 19 (SD: 5) for kinetics. We used a bootstrap procedure to determine the precision of GaitSD as a function of the number of strides processed. We compared the within-subject, stride-to-stride, variability with the, between-subject, variability of the normative pattern. Finally, we investigated the correlation between age and gait kinematic, kinetic and spatio-temporal variability. In typically developing children, the relative precision of GaitSD was 10% as soon as 6 strides were captured. As a comparison, spatio-temporal parameters required 30 strides to reach the same relative precision. The ratio stride-to-stride divided by normative pattern variability was smaller in kinematic variables (the smallest for pelvic tilt, 28%) than in kinetic and spatio-temporal variables (the largest for normalised stride length, 95%). GaitSD had a strong, negative correlation with age. We show that gait consistency may stabilise only at, or after, skeletal maturity. Copyright © 2016 Elsevier B.V. All rights reserved.

Greater contribution of cerebral than extracerebral hemodynamics to near-infrared spectroscopy signals for functional activation and resting-state connectivity in infants.

PubMed

Funane, Tsukasa; Homae, Fumitaka; Watanabe, Hama; Kiguchi, Masashi; Taga, Gentaro

2014-10-01

While near-infrared spectroscopy (NIRS) has been increasingly applied to neuroimaging and functional connectivity studies in infants, it has not been quantitatively examined as to what extent the deep tissue (such as cerebral tissue) as opposed to shallow tissue (such as scalp), contributes to NIRS signals measured in infants. A method for separating the effects of deep- and shallow-tissue layers was applied to data of nine sleeping three-month-old infants who had been exposed to 3-s speech sounds or silence (i.e., resting state) and whose hemodynamic changes over their bilateral temporal cortices had been measured by using an NIRS system with multiple source-detector (S-D) distances. The deep-layer contribution was found to be large during resting [67% at S-D 20 mm, 78% at S-D 30 mm for oxygenated hemoglobin (oxy-Hb)] as well as during the speech condition (72% at S-D 20 mm, 82% at S-D 30 mm for oxy-Hb). A left-right connectivity analysis showed that correlation coefficients between left and right channels did not differ between original- and deep-layer signals under no-stimulus conditions and that of original- and deep-layer signals were larger than those of the shallow layer. These results suggest that NIRS signals obtained in infants with appropriate S-D distances largely reflected cerebral hemodynamic changes.

Greater contribution of cerebral than extracerebral hemodynamics to near-infrared spectroscopy signals for functional activation and resting-state connectivity in infants

PubMed Central

Funane, Tsukasa; Homae, Fumitaka; Watanabe, Hama; Kiguchi, Masashi; Taga, Gentaro

2014-01-01

Abstract. While near-infrared spectroscopy (NIRS) has been increasingly applied to neuroimaging and functional connectivity studies in infants, it has not been quantitatively examined as to what extent the deep tissue (such as cerebral tissue) as opposed to shallow tissue (such as scalp), contributes to NIRS signals measured in infants. A method for separating the effects of deep- and shallow-tissue layers was applied to data of nine sleeping three-month-old infants who had been exposed to 3-s speech sounds or silence (i.e., resting state) and whose hemodynamic changes over their bilateral temporal cortices had been measured by using an NIRS system with multiple source-detector (S-D) distances. The deep-layer contribution was found to be large during resting [67% at S-D 20 mm, 78% at S-D 30 mm for oxygenated hemoglobin (oxy-Hb)] as well as during the speech condition (72% at S-D 20 mm, 82% at S-D 30 mm for oxy-Hb). A left-right connectivity analysis showed that correlation coefficients between left and right channels did not differ between original- and deep-layer signals under no-stimulus conditions and that of original- and deep-layer signals were larger than those of the shallow layer. These results suggest that NIRS signals obtained in infants with appropriate S-D distances largely reflected cerebral hemodynamic changes. PMID:26157977

Dedifferentiated retroperitoneal liposarcoma spontaneously occurring in an aged SD rat

PubMed Central

Naito, Tomoharu; Saito, Tsuyoshi; Higuchi, Tamami; Inomata, Akira; Hayashi, Takuo; Shimada, Yasuhiro; Yamauchi-Ohguchi, Atsuko; Kenmochi, Sayaka; Kakinuma, Chihaya; Yao, Takashi

2018-01-01

Liposarcoma is a rare neoplasm in rats and is characterized by the presence of lipoblasts containing multiple cytoplasmic vacuoles. We encountered a rare type of liposarcoma in a male SD (Crj:CD(SD)IGS) rat during a long-term study to gather background data. At necropsy at 105 weeks of age, there was a large amount of fatty tissue covering the mesentery, pancreas, and retroperitoneum; a white nodule in the right kidney; and paleness of the liver. Microscopically, the tumor had a well-differentiated component and dedifferentiated high-grade component. Immunohistochemical and electron microscopic examinations revealed that the pleomorphic tumor cells retained the characteristics of lipoblasts. Distant or disseminated metastasis was also confirmed in various organs. A liposarcoma with these histological features is extremely rare in rats, and this is the first report of a highly metastatic dedifferentiated type of liposarcoma originating from the abdominal fat tissue in a rat. PMID:29750003

Dedifferentiated retroperitoneal liposarcoma spontaneously occurring in an aged SD rat.

PubMed

Naito, Tomoharu; Saito, Tsuyoshi; Higuchi, Tamami; Inomata, Akira; Hayashi, Takuo; Shimada, Yasuhiro; Yamauchi-Ohguchi, Atsuko; Kenmochi, Sayaka; Kakinuma, Chihaya; Yao, Takashi

2018-04-01

Liposarcoma is a rare neoplasm in rats and is characterized by the presence of lipoblasts containing multiple cytoplasmic vacuoles. We encountered a rare type of liposarcoma in a male SD (Crj:CD(SD)IGS) rat during a long-term study to gather background data. At necropsy at 105 weeks of age, there was a large amount of fatty tissue covering the mesentery, pancreas, and retroperitoneum; a white nodule in the right kidney; and paleness of the liver. Microscopically, the tumor had a well-differentiated component and dedifferentiated high-grade component. Immunohistochemical and electron microscopic examinations revealed that the pleomorphic tumor cells retained the characteristics of lipoblasts. Distant or disseminated metastasis was also confirmed in various organs. A liposarcoma with these histological features is extremely rare in rats, and this is the first report of a highly metastatic dedifferentiated type of liposarcoma originating from the abdominal fat tissue in a rat.

Does standard deviation matter? Using "standard deviation" to quantify security of multistage testing.

PubMed

Wang, Chun; Zheng, Yi; Chang, Hua-Hua

2014-01-01

With the advent of web-based technology, online testing is becoming a mainstream mode in large-scale educational assessments. Most online tests are administered continuously in a testing window, which may post test security problems because examinees who take the test earlier may share information with those who take the test later. Researchers have proposed various statistical indices to assess the test security, and one most often used index is the average test-overlap rate, which was further generalized to the item pooling index (Chang & Zhang, 2002, 2003). These indices, however, are all defined as the means (that is, the expected proportion of common items among examinees) and they were originally proposed for computerized adaptive testing (CAT). Recently, multistage testing (MST) has become a popular alternative to CAT. The unique features of MST make it important to report not only the mean, but also the standard deviation (SD) of test overlap rate, as we advocate in this paper. The standard deviation of test overlap rate adds important information to the test security profile, because for the same mean, a large SD reflects that certain groups of examinees share more common items than other groups. In this study, we analytically derived the lower bounds of the SD under MST, with the results under CAT as a benchmark. It is shown that when the mean overlap rate is the same between MST and CAT, the SD of test overlap tends to be larger in MST. A simulation study was conducted to provide empirical evidence. We also compared the security of MST under the single-pool versus the multiple-pool designs; both analytical and simulation studies show that the non-overlapping multiple-pool design will slightly increase the security risk.

Pulsar Pair Cascades in Magnetic Fields with Offset Polar Caps

NASA Technical Reports Server (NTRS)

Harding, Alice K.; Muslimov, Alex G.

2012-01-01

Neutron star magnetic fields may have polar caps (PC) that are offset from the dipole axis, through field-line sweepback near the light cylinder or non-symmetric currents within the star. The effects of such offsets on electron-positron pair cascades are investigated, using simple models of dipole magnetic fields with small distortions that shift the PCs by different amounts or directions. Using a Monte Carlo pair cascade simulation, we explore the changes in the pair spectrum, multiplicity and energy flux across the PC, as well as the trends in pair flux and pair energy flux with spin-down luminosity, L(sub sd). We also give an estimate of the distribution of heating flux from returning positrons on the PC for different offsets. We find that even modest offsets can produce significant increases in pair multiplicity, especially for pulsars that are near or beyond the pair death lines for centered PCs, primarily because of higher accelerating fields. Pair spectra cover several decades in energy, with the spectral range of millisecond pulsars (MSPs) two orders of magnitude higher than for normal pulsars, and PC offsets allow significant extension of all spectra to lower pair energies. We find that the total PC pair luminosity L(sub pair) is proportional to L(sub sd), with L(sub pair) approximates 10(exp -3) L(sub sd) for normal pulsars and L(sub pair) approximates 10(exp -2) L(sub sd) for MSPs. Remarkably, the total PC heating luminosity for even large offsets increases by less than a factor of two, even though the PC area increases by much larger factors, because most of the heating occurs near the magnetic axis.

Growing old with fibromyalgia: factors that predict physical function.

PubMed

Torma, Linda M; Houck, Gail M; Wagnild, Gail M; Messecar, Deborah; Jones, Kim Dupree

2013-01-01

Fibromyalgia, a persistent, widespread pain condition, significantly limits physical function, threatening an older adult's health and ability to live independently. The aim of the study was to identify predictors of physical function in older adults living with fibromyalgia and to examine the influence of resilience on the relationship between fibromyalgia pain and physical function. This was a descriptive correlational, cross-sectional design using mailed questionnaires to analyze relationships between health-related variables and physical function in a convenience sample of community-dwelling older adults diagnosed with fibromyalgia (n = 224; age M = 62.1 years, SD = 6.75 years). Multiple regression was used to identify a priori predictors of physical function; hierarchical multiple regression was used to examine resilience as a moderator of pain and physical function. The sample was predominantly women, Caucasian, married, well educated, had moderate levels of income and tangible social support, and had low levels of physical function. Three-fourths were overweight or obese. Despite impaired physical function (Late Life Function and Disability Index, M = 51.5/100, SD = 9) and moderate levels of pain (Numeric Rating Scale, M = 5.47/10, SD = 2.6), resilience was moderately high (Resilience Scale, M = 137/175, SD = 20). An eight-variable disablement-based model accounted for 48% of variance in physical function: age, income, education, depressive symptoms, body mass index, and physical activity accounted for 31%; pain added 14%; and resilience contributed an additional 3%. Resilience was not a moderator of fibromyalgia pain and physical function; resilience did contribute uniquely to physical function variance. Resilience, a novel variable in fibromyalgia research, was a unique predictor of physical function. Further research is needed to learn more about the relationships between resilience, fibromyalgia impact, and the aging process.

Low dietary diversity and micronutrient adequacy among lactating women in a peri-urban area of Nepal.

PubMed

Henjum, Sigrun; Torheim, Liv Elin; Thorne-Lyman, Andrew L; Chandyo, Ram; Fawzi, Wafaie W; Shrestha, Prakash S; Strand, Tor A

2015-12-01

The main objectives were to assess the adequacy of the micronutrient intakes of lactating women in a peri-urban area in Nepal and to describe the relationships between micronutrient intake adequacy, dietary diversity and sociodemographic variables. A cross-sectional survey was performed during 2008-2009. We used 24 h dietary recall to assess dietary intake on three non-consecutive days and calculated the probability of adequacy (PA) of the usual intake of eleven micronutrients and the overall mean probability of adequacy (MPA). A mean dietary diversity score (MDDS) was calculated of eight food groups averaged over 3 d. Multiple linear regression was used to identify the determinants of the MPA. Bhaktapur municipality, Nepal. Lactating women (n 500), 17-44 years old, randomly selected. The mean usual energy intake was 8464 (sd 1305) kJ/d (2023 (sd 312) kcal/d), while the percentage of energy from protein, fat and carbohydrates was 11 %, 13 % and 76 %, respectively. The mean usual micronutrient intakes were below the estimated average requirements for all micronutrients, with the exception of vitamin C and Zn. The MPA across eleven micronutrients was 0·19 (sd 0·16). The diet was found to be monotonous (MDDS was 3·9 (sd 1·0)) and rice contributed to about 60 % of the energy intake. The multiple regression analyses showed that MPA was positively associated with energy intake, dietary diversity, women's educational level and socio-economic status, and was higher in the winter. The low micronutrient intakes are probably explained by low dietary diversity and a low intake of micronutrient-rich foods.

The comparability of English, French and Dutch scores on the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F): an assessment of differential item functioning in patients with systemic sclerosis.

PubMed

Kwakkenbos, Linda; Willems, Linda M; Baron, Murray; Hudson, Marie; Cella, David; van den Ende, Cornelia H M; Thombs, Brett D

2014-01-01

The Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) is commonly used to assess fatigue in rheumatic diseases, and has shown to discriminate better across levels of the fatigue spectrum than other commonly used measures. The aim of this study was to assess the cross-language measurement equivalence of the English, French, and Dutch versions of the FACIT-F in systemic sclerosis (SSc) patients. The FACIT-F was completed by 871 English-speaking Canadian, 238 French-speaking Canadian and 230 Dutch SSc patients. Confirmatory factor analysis was used to assess the factor structure in the three samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF), comparing English versus French and versus Dutch patient responses separately. A unidimensional factor model showed good fit in all samples. Comparing French versus English patients, statistically significant, but small-magnitude DIF was found for 3 of 13 items. French patients had 0.04 of a standard deviation (SD) lower latent fatigue scores than English patients and there was an increase of only 0.03 SD after accounting for DIF. For the Dutch versus English comparison, 4 items showed small, but statistically significant, DIF. Dutch patients had 0.20 SD lower latent fatigue scores than English patients. After correcting for DIF, there was a reduction of 0.16 SD in this difference. There was statistically significant DIF in several items, but the overall effect on fatigue scores was minimal. English, French and Dutch versions of the FACIT-F can be reasonably treated as having equivalent scoring metrics.

Multiple OPR genes influence personality traits in substance dependent and healthy subjects in two American populations

PubMed Central

Luo, Xingguang; Zuo, Lingjun; Kranzler, Henry; Zhang, Huiping; Wang, Shuang; Gelernter, Joel

2011-01-01

Background Personality traits are among the most complex quantitative traits. Certain personality traits are associated with substance dependence (SD); genetic factors may influence both. Associations between opioid receptor (OPR) genes and SD have been reported. This study investigated the relationship between OPR genes and personality traits in a case-control sample. Methods We assessed dimensions of the five-factor model of personality in 556 subjects: 250 with SD [181 European-Americans (EAs) and 69 African-Americans (AAs)] and 306 healthy subjects (266 EAs and 40 AAs). We genotyped 20 OPRM1 markers, 8 OPRD1 markers, and 7 OPRK1 markers, and 38 unlinked ancestry-informative markers in these subjects. The relationships between OPR genes and personality traits were examined using MANCOVA, controlling for gene-gene interaction effects and potential confounders. Associations were decomposed by Roy-Bargmann Stepdown ANCOVA. Results Personality traits were associated as main or interaction effects with the haplotypes, diplotypes, alleles and genotypes at the three OPR genes (0.002

The Comparability of English, French and Dutch Scores on the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F): An Assessment of Differential Item Functioning in Patients with Systemic Sclerosis

PubMed Central

Kwakkenbos, Linda; Willems, Linda M.; Baron, Murray; Hudson, Marie; Cella, David; van den Ende, Cornelia H. M.; Thombs, Brett D.

2014-01-01

Objective The Functional Assessment of Chronic Illness Therapy- Fatigue (FACIT-F) is commonly used to assess fatigue in rheumatic diseases, and has shown to discriminate better across levels of the fatigue spectrum than other commonly used measures. The aim of this study was to assess the cross-language measurement equivalence of the English, French, and Dutch versions of the FACIT-F in systemic sclerosis (SSc) patients. Methods The FACIT-F was completed by 871 English-speaking Canadian, 238 French-speaking Canadian and 230 Dutch SSc patients. Confirmatory factor analysis was used to assess the factor structure in the three samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF), comparing English versus French and versus Dutch patient responses separately. Results A unidimensional factor model showed good fit in all samples. Comparing French versus English patients, statistically significant, but small-magnitude DIF was found for 3 of 13 items. French patients had 0.04 of a standard deviation (SD) lower latent fatigue scores than English patients and there was an increase of only 0.03 SD after accounting for DIF. For the Dutch versus English comparison, 4 items showed small, but statistically significant, DIF. Dutch patients had 0.20 SD lower latent fatigue scores than English patients. After correcting for DIF, there was a reduction of 0.16 SD in this difference. Conclusions There was statistically significant DIF in several items, but the overall effect on fatigue scores was minimal. English, French and Dutch versions of the FACIT-F can be reasonably treated as having equivalent scoring metrics. PMID:24638101

An Assessment of the Measurement Equivalence of English and French Versions of the Center for Epidemiologic Studies Depression (CES-D) Scale in Systemic Sclerosis

PubMed Central

Delisle, Vanessa C.; Kwakkenbos, Linda; Hudson, Marie; Baron, Murray; Thombs, Brett D.

2014-01-01

Objectives Center for Epidemiologic Studies Depression (CES-D) Scale scores in English- and French-speaking Canadian systemic sclerosis (SSc) patients are commonly pooled in analyses, but no studies have evaluated the metric equivalence of the English and French CES-D. The study objective was to examine the metric equivalence of the CES-D in English- and French-speaking SSc patients. Methods The CES-D was completed by 1007 English-speaking and 248 French-speaking patients from the Canadian Scleroderma Research Group Registry. Confirmatory factor analysis (CFA) was used to assess the factor structure in both samples. The Multiple-Indicator Multiple-Cause (MIMIC) model was utilized to assess differential item functioning (DIF). Results A two-factor model (Positive and Negative affect) showed excellent fit in both samples. Statistically significant, but small-magnitude, DIF was found for 3 of 20 CES-D items, including items 3 (Blues), 10 (Fearful), and 11 (Sleep). Prior to accounting for DIF, French-speaking patients had 0.08 of a standard deviation (SD) lower latent scores for the Positive factor (95% confidence interval [CI]−0.25 to 0.08) and 0.09 SD higher scores (95% CI−0.07 to 0.24) for the Negative factor than English-speaking patients. After DIF correction, there was no change on the Positive factor and a non-significant increase of 0.04 SD on the Negative factor for French-speaking patients (difference = 0.13 SD, 95% CI−0.03 to 0.28). Conclusions The English and French versions of the CES-D, despite minor DIF on several items, are substantively equivalent and can be used in studies that combine data from English- and French-speaking Canadian SSc patients. PMID:25036894

Triaxial Permeability Device

DTIC Science & Technology

1988-01-01

potential for particle migration which can lead to piping, clogging, or hydraulic fracturing . Since the chemical conductivity under the high gradient...U~ .. .. - > 63 consolidation or expansion, it may be concluded that this gradient did not cause piping, clogging, or hydraulic fracturing for

Portable FWD (Prima 100) for in-situ subgrade evaluation.

DOT National Transportation Integrated Search

2006-06-01

Subgrade soil characterization measured in terms of resilient modulus, MR, has been a prerequisite for pavement design. For new pavement design, MR is obtained by conducting repeated load triaxial tests on reconstituted/undisturbed cylindrical specim...

Effect of Mechanical Heterogeneity on the Crack Driving Force of a Reactor Pressure Vessel Outlet Nozzle DMW Joint

NASA Astrophysics Data System (ADS)

Lingyan, Zhao; Yinghao, Cui; He, Xue

2017-12-01

The welding mechanical heterogeneity, load complexity, material and geometrical structure makes it very difficult to assess the structural integrity of dissimilar metal weld (DMW) joints. Based on a numerical simulated approach of the continuous change of material mechanical property in the buttering layer, a reactor pressure vessel (RPV) outlet nozzle DMW joint with service loads is studied, effect of mechanical heterogeneity on the stress-strain field and stress triaxiality at the semi-elliptical surface crack front are discussed. The analyses show that once the crack extends into the high hardness zone of Alloy 182 buttering, the strain decreases sharply, the strain gradient increases and the crack propagation slows down. The influence of strength mismatch on the stress triaxiality at the shallow crack front is greater than that at the deep crack front. The interaction between strength mismatch and crack depth directly affects the crack growth direction.

Assessment of the mechanical properties of sisal fiber-reinforced silty clay using triaxial shear tests.

PubMed

Wu, Yankai; Li, Yanbin; Niu, Bin

2014-01-01

Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment.

Intrinsic properties of high-spin band structures in triaxial nuclei

NASA Astrophysics Data System (ADS)

Jehangir, S.; Bhat, G. H.; Sheikh, J. A.; Palit, R.; Ganai, P. A.

2017-12-01

The band structures of 68,70Ge, 128,130,132,134Ce and 132,134,136,138Nd are investigated using the triaxial projected shell model (TPSM) approach. These nuclei depict forking of the ground-state band into several s-bands and in some cases, both the lowest two observed s-bands depict neutron or proton character. It was discussed in our earlier work that this anomalous behaviour can be explained by considering γ-bands based on two-quasiparticle configurations. As the parent band and the γ-band built on it have the same intrinsic structure, g-factors of the two bands are expected to be similar. In the present work, we have undertaken a detailed investigation of g-factors for the excited band structures of the studied nuclei and the available data for a few high-spin states are shown to be in fair agreement with the predicted values.

Design modification and optimisation of the perfusion system of a tri-axial bioreactor for tissue engineering.

PubMed

Hussein, Husnah; Williams, David J; Liu, Yang

2015-07-01

A systematic design of experiments (DOE) approach was used to optimize the perfusion process of a tri-axial bioreactor designed for translational tissue engineering exploiting mechanical stimuli and mechanotransduction. Four controllable design parameters affecting the perfusion process were identified in a cause-effect diagram as potential improvement opportunities. A screening process was used to separate out the factors that have the largest impact from the insignificant ones. DOE was employed to find the settings of the platen design, return tubing configuration and the elevation difference that minimise the load on the pump and variation in the perfusion process and improve the controllability of the perfusion pressures within the prescribed limits. DOE was very effective for gaining increased knowledge of the perfusion process and optimizing the process for improved functionality. It is hypothesized that the optimized perfusion system will result in improved biological performance and consistency.

An Optical Interferometric Triaxial Displacement Sensor for Structural Health Monitoring: Characterization of Sliding and Debonding for a Delamination Process

PubMed Central

Chen, Yizheng; Zhuang, Yiyang; Du, Yang; Gerald, Rex E.; Tang, Yan

2017-01-01

This paper presents an extrinsic Fabry–Perot interferometer-based optical fiber sensor (EFPI) for measuring three-dimensional (3D) displacements, including interfacial sliding and debonding during delamination. The idea employs three spatially arranged EFPIs as the sensing elements. In our sensor, the three EFPIs are formed by three endfaces of three optical fibers and their corresponding inclined mirrors. Two coincident roof-like metallic structures are used to support the three fibers and the three mirrors, respectively. Our sensor was calibrated and then used to monitor interfacial sliding and debonding between a long square brick of mortar and its support structure (i.e., a steel base plate) during the drying/curing process. This robust and easy-to-manufacture triaxial EFPI-based 3D displacement sensor has great potential in structural health monitoring, the construction industry, oil well monitoring, and geotechnology. PMID:29165351

An Optical Interferometric Triaxial Displacement Sensor for Structural Health Monitoring: Characterization of Sliding and Debonding for a Delamination Process.

PubMed

Zhu, Chen; Chen, Yizheng; Zhuang, Yiyang; Du, Yang; Gerald, Rex E; Tang, Yan; Huang, Jie

2017-11-22

This paper presents an extrinsic Fabry-Perot interferometer-based optical fiber sensor (EFPI) for measuring three-dimensional (3D) displacements, including interfacial sliding and debonding during delamination. The idea employs three spatially arranged EFPIs as the sensing elements. In our sensor, the three EFPIs are formed by three endfaces of three optical fibers and their corresponding inclined mirrors. Two coincident roof-like metallic structures are used to support the three fibers and the three mirrors, respectively. Our sensor was calibrated and then used to monitor interfacial sliding and debonding between a long square brick of mortar and its support structure (i.e., a steel base plate) during the drying/curing process. This robust and easy-to-manufacture triaxial EFPI-based 3D displacement sensor has great potential in structural health monitoring, the construction industry, oil well monitoring, and geotechnology.

Triaxial digital fluxgate magnetometer for NASA applications explorer mission: Results of tests of critical elements

NASA Technical Reports Server (NTRS)

Mcleod, M. G.; Means, J. D.

1977-01-01

Tests performed to prove the critical elements of the triaxial digital fluxgate magnetometer design were described. A method for improving the linearity of the analog to digital converter portion of the instrument was studied in detail. A sawtooth waveform was added to the signal being measured before the A/D conversion, and averaging the digital readings over one cycle of the sawtooth. It was intended to reduce bit error nonlinearities present in the A/D converter which could be expected to be as much as 16 gamma if not reduced. No such nonlinearities were detected in the output of the instrument which included the feature designed to reduce these nonlinearities. However, a small scale nonlinearity of plus or minus 2 gamma with a 64 gamma repetition rate was observed in the unit tested. A design improvement intended to eliminate this small scale nonlinearity was examined.

Reduced probabilities for E2 transitions between excited collective states of triaxial even–even nuclei

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

Nadyrbekov, M. S., E-mail: nodirbekov@inp.uz; Bozarov, O. A.

Reduced probabilities for intra- and interband E2 transitions in excited collective states of even–even lanthanide and actinide nuclei are analyzed on the basis of a model that admits an arbitrary triaxiality. They are studied in detail in the energy spectra of {sup 154}Sm, {sup 156}Gd, {sup 158}Dy, {sup 162,164}Er, {sup 230,232}Th, and {sup 232,234,236,238}U even–even nuclei. Theoretical and experimental values of the reduced probabilities for the respective E2 transitions are compared. This comparison shows good agreement for all states, including high-spin ones. The ratios of the reduced probabilities for the E2 transitions in question are compared with results following frommore » the Alaga rules. These comparisons make it possible to assess the sensitivity of the probabilities being considered to the presence of quadrupole deformations.« less

In-beam spectroscopy of medium- and high-spin states in Ce 133

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

Ayangeakaa, A. D.; Garg, U.; Petrache, C. M.

2016-05-01

Medium and high-spin states in Ce-133 were investigated using the Cd-116(Ne-22, 5n) reaction and the Gammasphere array. The level scheme was extended up to an excitation energy of similar to 22.8 MeV and spin 93/2 (h) over bar. Eleven bands of quadrupole transitions and two new dipole bands are identified. The connections to low-lying states of the previously known, high-spin triaxial bands were firmly established, thus fixing the excitation energy and, in many cases, the spin parity of the levels. Based on comparisons with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant density functional theory, it is shown that allmore » observed bands are characterized by pronounced triaxiality. Competing multiquasiparticle configurations are found to contribute to a rich variety of collective phenomena in this nucleus.« less

Experimental and Numerical Investigations on Strength and Deformation Behavior of Cataclastic Sandstone

NASA Astrophysics Data System (ADS)

Zhang, Y.; Shao, J. F.; Xu, W. Y.; Zhao, H. B.; Wang, W.

2015-05-01

This work is devoted to characterization of the deformation and strength properties of cataclastic sandstones. Before conducting mechanical tests, the physical properties were first examined. These sandstones are characterized by a loose damaged microstructure and poorly cemented contacts. Then, a series of mechanical tests including hydrostatic, uniaxial, and triaxial compression tests were performed to study the mechanical strength and deformation of the sandstones. The results obtained show nonlinear stress-strain responses. The initial microcracks are closed at hydrostatic stress of 2.6 MPa, and the uniaxial compressive strength is about 0.98 MPa. Under triaxial compression, there is a clear transition from volumetric compressibility to dilatancy and a strong dependency on confining pressure. Based on the experimental evidence, an elastoplastic model is proposed using a linear yield function and a nonassociated plastic potential. There is good agreement between numerical results and experimental data.

Investigating the large deformation of the 5 /2+ isomeric state in 73Zn: An indicator for triaxiality

NASA Astrophysics Data System (ADS)

Yang, X. F.; Tsunoda, Y.; Babcock, C.; Billowes, J.; Bissell, M. L.; Blaum, K.; Cheal, B.; Flanagan, K. T.; Garcia Ruiz, R. F.; Gins, W.; Gorges, C.; Grob, L. K.; Heylen, H.; Kaufmann, S.; Kowalska, M.; Krämer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Otsuka, T.; Papuga, J.; Sánchez, R.; Wraith, C.; Xie, L.; Yordanov, D. T.

2018-04-01

Recently reported nuclear spins and moments of neutron-rich Zn isotopes measured at ISOLDE-CERN [C. Wraith et al., Phys. Lett. B 771, 385 (2017), 10.1016/j.physletb.2017.05.085] show an uncommon behavior of the isomeric state in 73Zn. Additional details relating to the measurement and analysis of the Znm73 hyperfine structure are addressed here to further support its spin-parity assignment 5 /2+ and to estimate its half-life. A systematic investigation of this 5 /2+ isomer indicates that significant collectivity appears due to proton/neutron E 2 excitations across the proton Z = 28 and neutron N = 50 shell gaps. This is confirmed by the good agreement of the observed quadrupole moments with large scale Monte Carlo shell model calculations. In addition, potential energy surface calculations in combination with T plots reveal a triaxial shape for this isomeric state.

Falls event detection using triaxial accelerometry and barometric pressure measurement.

PubMed

Bianchi, Federico; Redmond, Stephen J; Narayanan, Michael R; Cerutti, Sergio; Celler, Branko G; Lovell, Nigel H

2009-01-01

A falls detection system, employing a Bluetooth-based wearable device, containing a triaxial accelerometer and a barometric pressure sensor, is described. The aim of this study is to evaluate the use of barometric pressure measurement, as a surrogate measure of altitude, to augment previously reported accelerometry-based falls detection algorithms. The accelerometry and barometric pressure signals obtained from the waist-mounted device are analyzed by a signal processing and classification algorithm to discriminate falls from activities of daily living. This falls detection algorithm has been compared to two existing algorithms which utilize accelerometry signals alone. A set of laboratory-based simulated falls, along with other tasks associated with activities of daily living (16 tests) were performed by 15 healthy volunteers (9 male and 6 female; age: 23.7 +/- 2.9 years; height: 1.74 +/- 0.11 m). The algorithm incorporating pressure information detected falls with the highest sensitivity (97.8%) and the highest specificity (96.7%).

Effectiveness of team-based learning methodology in teaching transfusion medicine to medical undergraduates in third semester: A comparative study.

PubMed

Doshi, Neena Piyush

2017-01-01

Team-based learning (TBL) combines small and large group learning by incorporating multiple small groups in a large group setting. It is a teacher-directed method that encourages student-student interaction. This study compares student learning and teaching satisfaction between conventional lecture and TBL in the subject of pathology. The present study is aimed to assess the effectiveness of TBL method of teaching over the conventional lecture. The present study was conducted in the Department of Pathology, GMERS Medical College and General Hospital, Gotri, Vadodara, Gujarat. The study population comprised 126 students of second-year MBBS, in their third semester of the academic year 2015-2016. "Hemodynamic disorders" were taught by conventional method and "transfusion medicine" by TBL method. Effectiveness of both the methods was assessed. A posttest multiple choice question was conducted at the end of "hemodynamic disorders." Assessment of TBL was based on individual score, team score, and each member's contribution to the success of the team. The individual score and overall score were compared with the posttest score on "hemodynamic disorders." A feedback was taken from the students regarding their experience with TBL. Tukey's multiple comparisons test and ANOVA summary were used to find the significance of scores between didactic and TBL methods. Student feedback was taken using "Student Satisfaction Scale" based on Likert scoring method. The mean of student scores by didactic, Individual Readiness Assurance Test (score "A"), and overall (score "D") was 49.8% (standard deviation [SD]-14.8), 65.6% (SD-10.9), and 65.6% (SD-13.8), respectively. The study showed positive educational outcome in terms of knowledge acquisition, participation and engagement, and team performance with TBL.

The causal nature of the association between neighborhood deprivation and drug abuse: a prospective national Swedish co-relative control study

PubMed Central

Kendler, K. S.; Ohlsson, H.; Sundquist, K.; Sundquist, J.

2014-01-01

Background Risk for drug abuse (DA) is strongly associated with neighborhood social deprivation (SD). However, the causal nature of this relationship is unclear. Method Three Swedish population-based cohorts were followed up over 5 years for incident registration of DA in medical, legal or pharmacy records. In each cohort, we examined the SD–DA association, controlling carefully for individual socio-economic status (SES) with multiple measures, in the entire sample and among pairs of first cousins, paternal and maternal half-siblings, full siblings and monozygotic (MZ) twins discordant for SD exposure. The number of informative relative pairs ranged from 6366 to 166208. Results In all cohorts, SD was prospectively related to risk for incident DA. In relative pairs discordant for SD exposure, the SD–DA association was similar to that seen in the entire population in cousins, half-siblings, full siblings and MZ twins. Eliminating subjects who were residentially unstable or had DA in the first two follow-up years did not alter this pattern. When divided by age, in the youngest groups, the SD–DA association was weaker in siblings than in the entire population. Conclusions Across three cohorts, controlling for individual SES and confounding familial factors, SD prospectively predicted risk for incident DA registration. These results support the hypothesis that the SD–DA association is in part causal and unlikely to result entirely from personal attributes, which both increase risk for DA and cause selection into high SD environments. At least part of the SD–DA association arises because exposure to SD causes an increased risk of DA. PMID:25055172

[Functional status, self-rated health and level of physical activity of patients with osteoarthritis].

PubMed

Val Jiménez, Carmen Llanos; López-Torres Hidalgo, Jesús; García Atienza, Eva María; Navarro Ruiz, María Soledad; Hernández Cerón, Inmaculada; Moreno de la Rosa, Lorena

2017-04-01

To describe the functional status and self-rated health of patients with osteoarthritis (OA) in Primary Care, and checking their relationship with the level of physical activity and sociodemographic characteristics. Study of prevalence and cross association. Primary Care Clinics. Adult patients with a diagnosis of OA in any joint in their clinical records. Out of a total of 487 selected, 346 (71.0%) took part in the study. Functional capacity (WOMAC scale), self-rated quality of life (EuroQol- 5D questionnaire), physical activity (IPAQ questionnaire), number of affected joints, pain level, and sociodemographic characteristics. A mean score of 30.2 (SD: 20.8; CI 95% CI: 28.0 to 32.4) was obtained on the WOMAC scale, with pain, stiffness, and functional capacity scores of 6.5 (SD: 4.8), 1.9 (SD: 2.0), and 21.7 (SD: 15.7), respectively. The score showed a linear trend (P<.001) compared to the level of physical activity, being 41.1 (SD: 19.9) in inactive subjects, 24.3 (SD: 18.7) in subjects with moderate activity, and 22.3 (SD: 19.8) in subjects with intense activity. In the multiple linear regression, the score on the WOMAC scale, as well as that obtained in self-rated health status, maintained their association with physical activity level after adjusting for sociodemographic variables and the number of affected joints. In patients with OA, pain and functional capacity are the most affected dimensions. Functional status and self-rated health status are higher in active patients, regardless of the number of joints affected and their demographic characteristics. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

NASA Astrophysics Data System (ADS)

Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

2013-11-01

In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

3D controlled electrorotation of conducting tri-axial ellipsoidal nanoparticles

NASA Astrophysics Data System (ADS)

Weis Goldstein, Ben; Miloh, Touvia

2017-05-01

We present a theoretical study of 3D electrorotation of ideally polarizable (metallic) nano∖micro-orthotropic particles that are freely suspended in an unbounded monovalent symmetric electrolyte. The metallic tri-axial ellipsoidal particle is subjected to three independent uniform AC electric fields acting along the three principal axes of the particle. The analysis of the electrokinetic problem is carried under the Poisson-Nernst-Planck approximation and the standard "weak" field assumption. For simplicity, we consider the electric double layer as thin and the Dukhin number to be small. Both nonlinear phenomena of dielectrophoresis induced by the dipole-moment within the particle and the induced-charge electrophoresis caused by the Coulombic force density within the Debye layer in the solute surrounding the conducting particle are analytically analyzed by linearization, constructing approximate expressions for the total dipolophoresis angular particle motion for various geometries. The analytical expressions thus obtained are valid for an arbitrary tri-axial orthotropic (exhibiting three planes of symmetry) particle, excited by an arbitrary ambient three-dimensional AC electric field of constant amplitude. The present study is general in the sense that by choosing different geometric parameters of the ellipsoidal particle, the corresponding nonlinear electrostatic problem governed by the Robin (mixed-type) boundary condition can be reduced to common nano-shapes including spheres, slender rods (needles), prolate and oblate spheroids, as well as flat disks. Furthermore, by controlling the parameters (amplitudes and phases) of the forcing electric field, one can reduce the present general 3D electrokinetic model to the familiar planar electro-rotation (ROT) and electro-orientation (EOR) cases.

Inferring the gravitational potential of the Milky Way with a few precisely measured stars

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

Price-Whelan, Adrian M.; Johnston, Kathryn V.; Hendel, David

2014-10-10

The dark matter halo of the Milky Way is expected to be triaxial and filled with substructure. It is hoped that streams or shells of stars produced by tidal disruption of stellar systems will provide precise measures of the gravitational potential to test these predictions. We develop a method for inferring the Galactic potential with tidal streams based on the idea that the stream stars were once close in phase space. Our method can flexibly adapt to any form for the Galactic potential: it works in phase-space rather than action-space and hence relies neither on our ability to derive actionsmore » nor on the integrability of the potential. Our model is probabilistic, with a likelihood function and priors on the parameters. The method can properly account for finite observational uncertainties and missing data dimensions. We test our method on synthetic data sets generated from N-body simulations of satellite disruption in a static, multi-component Milky Way, including a triaxial dark matter halo with observational uncertainties chosen to mimic current and near-future surveys of various stars. We find that with just eight well-measured stream stars, we can infer properties of a triaxial potential with precisions of the order of 5%-7%. Without proper motions, we obtain 10% constraints on most potential parameters and precisions around 5%-10% for recovering missing phase-space coordinates. These results are encouraging for the goal of using flexible, time-dependent potential models combined with larger data sets to unravel the detailed shape of the dark matter distribution around the Milky Way.« less

Investigating coseismic fracture damage using a new high speed triaxial apparatus

NASA Astrophysics Data System (ADS)

Mitchell, T. M.; Aben, F. M.; Pricci, R.; Brantut, N.; Rockwell, T. K.; Boon, S.

2017-12-01

The occurence of pulverized rocks, a type of intensely damaged fault rock which has undergone minimal shear strain, has been linked to damage induced by transient high strain-rate stress perturbations during earthquake rupture. Damage induced by such transient stresses, whether compressional or tensional, likely constitute heterogeneous modulations of the remote stresses that will impart significant changes on the strength, elastic and fluid flow properties of a fault zone immediately after rupture propagation, at the early stage of fault slip. While the physical mechanisms for pulverized rock generation are still not yet fully understood, it is likely that they are in some way related to a combination of the dynamic compressive and tensional stresses imparted on the rock surrounding a fault at the tip of a propagating earthquake rupture. Typical triaxial rock deformation apparatuses are limited by their loading systems to strain rates on the order of 10-4 s-1, which in terms of the seismic cycle, is only applicable to processes operating within the inter-seismic period. In order to achieve strain rates in excess of 100 s-1 under confined conditions with pore fluids (currently unachievable with conventional deformation apparatus such as split bar Hopkinson), we have designed, manufactured and constructed a new high strain rate triaxial rock deformation apparatus, with a unique innovative hydraulic loading system that allows samples to be deformed in compression and tension at strain rates from 10-7 up to 200 s-1 . We present preliminary data demonstrating the unique capability of this apparatus to produce co-seismic experimental conditions not previously acheived.

Relationship between dilatancy, stresses and plastic dissipation in a granular material with rigid grains

NASA Astrophysics Data System (ADS)

Evesque, Pierre; Stefani, Christian

1991-11-01

By considering a drained cohesionless granular sample made up of rigid grains and submitted to a triaxial test, we derive an equation relating the dilatancy K, the deviatoric stress q and the confining pressure p to the energy losses D_plastic due to plastic yielding. We demonstrate that the system is contracting (K le 0) at q = 0, when q is increasing and that spontaneous uncontrolled yielding begins occurring when dilatancy K is maximum. We also demonstrate the existence of the characteristic state introduced by Luong and Habib and the existence of the critical state of Schofield and Wroth. Finally, we give a method to determine the plastic losses during a triaxial cell test using the experimental data. En utilisant un postulat de reproductibilité des essais triaxiaux et une relation liant l'énergie dissipée, la dilatance K et les contraintes imposées à un échantillon, on démontre qu'un matériau granulaire ne peut que se contracter après avoir subi une contrainte de confinement isotrope (i.e. q = 0), que la rupture spontanée a lieu après un maximum de dilatance, qu'il existe un état caractéristique (au sens de Luong et Habib) et qu'il existe un état “ critique ” (au sens de Schofield et Wroth). Nous donnons de plus une méthode pour estimer la dissipation-plastique durant un essai triaxial à partir des résultats expérimentaux.

A New Kinematic Model for Polymodal Faulting: Implications for Fault Connectivity

NASA Astrophysics Data System (ADS)

Healy, D.; Rizzo, R. E.

2015-12-01

Conjugate, or bimodal, fault patterns dominate the geological literature on shear failure. Based on Anderson's (1905) application of the Mohr-Coulomb failure criterion, these patterns have been interpreted from all tectonic regimes, including normal, strike-slip and thrust (reverse) faulting. However, a fundamental limitation of the Mohr-Coulomb failure criterion - and others that assume faults form parallel to the intermediate principal stress - is that only plane strain can result from slip on the conjugate faults. However, deformation in the Earth is widely accepted as being three-dimensional, with truly triaxial stresses and strains. Polymodal faulting, with three or more sets of faults forming and slipping simultaneously, can generate three-dimensional strains from truly triaxial stresses. Laboratory experiments and outcrop studies have verified the occurrence of the polymodal fault patterns in nature. The connectivity of polymodal fault networks differs significantly from conjugate fault networks, and this presents challenges to our understanding of faulting and an opportunity to improve our understanding of seismic hazards and fluid flow. Polymodal fault patterns will, in general, have more connected nodes in 2D (and more branch lines in 3D) than comparable conjugate (bimodal) patterns. The anisotropy of permeability is therefore expected to be very different in rocks with polymodal fault patterns in comparison to conjugate fault patterns, and this has implications for the development of hydrocarbon reservoirs, the genesis of ore deposits and the management of aquifers. In this contribution, I assess the published evidence and models for polymodal faulting before presenting a novel kinematic model for general triaxial strain in the brittle field.

Comparison and verification of two models which predict minimum principal in situ stress from triaxial data

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

Harikrishnan, R.; Hareland, G.; Warpinski, N.R.

This paper evaluates the correlation between values of minimum principal in situ stress derived from two different models which use data obtained from triaxial core tests and coefficient for earth at rest correlations. Both models use triaxial laboratory tests with different confining pressures. The first method uses a vcrified fit to the Mohr failure envelope as a function of average rock grain size, which was obtained from detailed microscopic analyses. The second method uses the Mohr-Coulomb failure criterion. Both approaches give an angle in internal friction which is used to calculate the coefficient for earth at rest which gives themore » minimum principal in situ stress. The minimum principal in situ stress is then compared to actual field mini-frac test data which accurately determine the minimum principal in situ stress and are used to verify the accuracy of the correlations. The cores and the mini-frac stress test were obtained from two wells, the Gas Research Institute`s (GRIs) Staged Field Experiment (SFE) no. 1 well through the Travis Peak Formation in the East Texas Basin, and the Department of Energy`s (DOE`s) Multiwell Experiment (MWX) wells located west-southwest of the town of Rifle, Colorado, near the Rulison gas field. Results from this study indicates that the calculated minimum principal in situ stress values obtained by utilizing the rock failure envelope as a function of average rock grain size correlation are in better agreement with the measured stress values (from mini-frac tests) than those obtained utilizing Mohr-Coulomb failure criterion.« less

Full-field Measurements of Strain Localisation in Sandstone by Neutron Tomography and 3D-Volumetric Digital Image Correlation

NASA Astrophysics Data System (ADS)

Tudisco, E.; Hall, S. A.; Charalampidou, E. M.; Kardjilov, N.; Hilger, A.; Sone, H.

Recent studies have demonstrated that the combination of x-ray tomography during triaxial tests (;in-situ; tests) and 3D- volumetric Digital Image Correlation (3D-DIC) can provide important insight into the mechanical behaviour and deformation processes of granular materials such as sand. The application of these tools to investigate the mechanisms of failure in rocks is also of obvious interest. However, the relevant applied confining pressures for triaxial testing on rocks are higher than those on sands and therefore stronger pressure containment vessels, i.e., made of thick metal walls, are required. This makes in-situ x-ray imaging of rock deformation during triaxial tests a challenge. One possible solution to overcome this problem is to use neutrons, which should better penetrate the metal-walls of the pressure vessels. In this perspective, this work assesses the capability of neutron tomography with 3D-DIC to measure deformation fields in rock samples. Results from pre- and post-deformation neutron tomography of a Bentheim sandstone sample deformed ex-situ at 40 MPa show that clear images of the internal structure can be achieved and utilised for 3D-DIC analysis to reveal the details of the 3D strain field. From these results the character of the localised deformation in the study sample can thus be described. Furthermore, comparison with analyses based on equivalent x-ray tomography imaging of the same sample confirms the effectiveness of the method in relation to the more established x-ray based approach.

Experiments on planetary ices at UCL

NASA Astrophysics Data System (ADS)

Grindrod, P. M.; Fortes, A. D.; Wood, I. G.; Dobson, D.; Sammonds, P. R.; Stone-Drake, L.; Vocadlo, L.

2007-08-01

Using a suite of techniques and equipment, we conduct several different types of experiments on planetary ices at UCL. Samples are prepared in the Ice Physics Laboratory, which consists of a 5 chamber complex of inter-connected cold rooms, controllable from +30 to -30 deg C. Within this laboratory we have a functioning triaxial deformation cell operating at low temperature (down to -90 deg C) and high pressures (300 MPa), an Automatic Ice Fabric Analyser (AIFA) and a low-temperature microscope with CCD output. Polycrystalline samples, 40mm diameter by 100mm long, are compressed in the triaxial rig with a confining pressure; single crystal specimens are compressed in a separate uniaxial creep rig which operates at zero confining pressure for surface studies. A cold stage is also available for study of ice microstructural studies on our new Jeol JSM-6480LV SEM, which also allows tensile, compression and/or bending tests, with load ranges from less than 2N to 5000N. Finally, we also use a cold stage on a new PANalytical, X'pert PRO MPD, high resolution powder diffractometer to study the structure and phase behaviour of icy materials. Recent highlights of our work include: (1) derivation of a manufacturing process for methane clathrate at low temperatures, analysed in the X-Ray Diffraction Laboratory, for future rheological experiments, (2) analysed the growth behaviour of MS11, (3) refurbished and commenced calibration tests on the triaxial deformation cell using ice Ih, and (4) performed creep tests on gypsum and epsomite using the single crystal deformation cell. Further experiments will build on these preliminary results.

A Brief Course on Clinical Communication Skills: A Multi- Centered Study.

PubMed

Franco, Camila; Franco, Renato; Severo, Milton; Ferreira, Maria Amélia

2016-12-30

This paper describes and analyses the results of a multicenter course on clinical communication skills with the use of the learning in small groups, patient actors and feedback. The aim of the course was to encourage participants to develop a more effective clinical communication to recognize the different manifestations of the same disease in different patients (disease versus illness). The course was applied to third and fourth year medical students in three Brazilian universities and one university in Portugal. The evaluation was performed using scales regarding the participants' point of view, multiple choice questionnaire, a self-efficacy and attitudinal questionnaire. The study was conducted in 69 participants at the four universities. The overall evaluation of the course (from 1 - 5) was 4.70 (SD 0.494), the self-evaluation on participation was 4.07 (SD 0.671); and the evaluation about the use of simulated patients 4.51 (SD 0.501). The multiple choice questionnaire and self-efficacy scale showed significant improvement. The course methods had an excellent evaluation by students regardless of the context in which the course has been applied. Furthermore, it allowed an improvement on the knowledge and attitude of students regarding clinical communication. It was possible to develop a multi-centric learning strategy for clinical communication with a high evaluation by students who came from a Portuguese university in a cooperation project with teachers from Brazilian universities.

Evaluating the Theoretical Content of Online Physical Activity Information for People with Multiple Sclerosis

PubMed Central

Baillie, Colin P.T.; Galaviz, Karla; Jarvis, Jocelyn W.; Latimer-Cheung, Amy E.

2015-01-01

Background: Physical activity can aid people with multiple sclerosis (MS) in managing symptoms and maintaining functional abilities. The Internet is a preferred source of physical activity information for people with MS and, therefore, a method for the dissemination of behavior change techniques. The purpose of this study was to examine the coverage and quality of physical activity behavior change techniques delivered on the Internet for adults with MS using Abraham and Michie's taxonomy of behavior change techniques. Methods: Using the taxonomy, 20 websites were coded for quality (ie, accuracy of information) and coverage (ie, completeness of information) of theoretical behavior change techniques. Results: Results indicated that most websites covered a mean of 8.05 (SD 3.86, range 3–16) techniques out of a possible 20. Only one of the techniques, provide information on behavior–health link and consequences, was delivered on all websites. The websites demonstrated low mean coverage and quality across all behavior change techniques, with means of 0.64 (SD 0.67) and 0.62 (SD 0.37) on a scale of 0 to 2, respectively. However, coverage and quality improved when websites were examined solely for the techniques that they covered, as opposed to all 20 techniques. Conclusions: This study, which examined quality and coverage of physical activity behavior change techniques described online for people with MS, illustrated that the dissemination of these techniques requires improvement. PMID:25892979

Comparison of qualitative and quantitative CT and MRI parameters for monitoring of longitudinal spine involvement in patients with multiple myeloma.

PubMed

Horger, M; Fritz, J; Thaiss, W M; Ditt, H; Weisel, K; Haap, M; Kloth, Christopher

2018-03-01

To compare qualitative and quantitative computed tomography (CT) and magnetic resonance imaging (MRI) parameters for longitudinal disease monitoring of multiple myeloma (MM) of the axial skeleton. We included 31 consecutive patients (17 m; mean age 59.20 ± 8.08 years) with MM, who underwent all baseline (n = 31) and at least one or more (n = 47) follow-up examinations consisting of multi-parametric non-enhanced whole-body MRI ( WB MRI) and non-enhanced whole-body reduced-dose thin-section MDCT (NEWBMDCT) between 06/2013 and 09/2016. We classified response according to qualitative CT criteria into progression (PD), stable(SD), partial/very good partial (PR/VGPR) and complete response(CR), grouping the latter three together for statistical analysis because CT cannot reliably assess PR and CR. Qualitative MR-response criteria were defined and grouped similarly to CT using longitudinal quantification of signal-intensity changes on T1w/STIR/ T2*w and calculating ADC-values. Standard of reference was the hematological laboratory (M-gradient). Hematological response categories were CR (14/47, 29.7%), PR (2/47, 4.2%), SD (16/47, 34.0%) and PD (15/47, 29.9%). Qualitative-CT-evaluation showed PD in 12/47 (25.5%) and SD/PR/VGPR/CR in 35/47 (74.5%) cases. These results were confirmed by quantitative-CT in all focal lytic lesions (p < 0.001). Quantitative-CT at sites with diffuse bone involvement showed significant increase of maximum bone attenuation (p < 0.001*) and significant decrease of minimal bone (p < 0.002*) in the SD/PR/VGPR/CR group. Qualitative MRI showed PD in 14/47 (29.7%) and SD/PR/VGPR/CR in 33/47 (70.3%). Quantitative MRI diagnosis showed a statistically significant decrease in signal intensity on short tau inversion recovery sequences (STIR) in bone marrow in patients with diffuse bone marrow involvement achieving SD/PR/VGPR/CR (p < 0.001*). Imaging response monitoring using MRI is superior to CT only if qualitative parameters are used, whereas there was no definite benefit from using quantitative parameters with either CT or MRI.

77 FR 11109 - Environmental Impacts Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

...-Native Plant Control Project, Proposes a Forest-Wide Integrated Management Strategy to Control the Spread..., Final EIS, USFS, SD, Steamboat Project, Proposes to Implement Multiple Resource Management Actions... EIS, USFS, WA, South George Vegetation and Fuels Management Project, To Improve Forest Health and...

Progressive decline of decision-making performances during multiple sclerosis.

PubMed

Simioni, Samanta; Ruffieux, Christiane; Kleeberg, Joerg; Bruggimann, Laure; du Pasquier, Renaud A; Annoni, Jean-Marie; Schluep, Myriam

2009-03-01

The purpose of this study was to evaluate longitudinally, using the Iowa Gambling Task (IGT), the dynamics of decision-making capacity at a two-year interval (median: 2.1 years) in a group of patients with multiple sclerosis (MS) (n = 70) and minor neurological disability [Expanded Disability Status Scale (EDSS) < or = 2.5 at baseline]. Cognition (memory, executive functions, attention), behavior, handicap, and perceived health status were also investigated. Standardized change scores [(score at retest-score at baseline)/standard deviation of baseline score] were computed. Results showed that IGT performances decreased from baseline to retest (from 0.3, SD = 0.4 to 0.1, SD = 0.3, p = .005). MS patients who worsened in the IGT were more likely to show a decreased perceived health status and emotional well-being (SEP-59; p = .05 for both). Relapsing rate, disability progression, cognitive, and behavioral changes were not associated with decreased IGT performances. In conclusion, decline in decision making can appear as an isolated deficit in MS.

Testing Measurement Invariance across Groups of Children with and without Attention-Deficit/ Hyperactivity Disorder: Applications for Word Recognition and Spelling Tasks

PubMed Central

Lúcio, Patrícia S.; Salum, Giovanni; Swardfager, Walter; Mari, Jair de Jesus; Pan, Pedro M.; Bressan, Rodrigo A.; Gadelha, Ary; Rohde, Luis A.; Cogo-Moreira, Hugo

2017-01-01

Although studies have consistently demonstrated that children with attention-deficit/hyperactivity disorder (ADHD) perform significantly lower than controls on word recognition and spelling tests, such studies rely on the assumption that those groups are comparable in these measures. This study investigates comparability of word recognition and spelling tests based on diagnostic status for ADHD through measurement invariance methods. The participants (n = 1,935; 47% female; 11% ADHD) were children aged 6–15 with normal IQ (≥70). Measurement invariance was investigated through Confirmatory Factor Analysis and Multiple Indicators Multiple Causes models. Measurement invariance was attested in both methods, demonstrating the direct comparability of the groups. Children with ADHD were 0.51 SD lower in word recognition and 0.33 SD lower in spelling tests than controls. Results suggest that differences in performance on word recognition and spelling tests are related to true mean differences based on ADHD diagnostic status. Implications for clinical practice and research are discussed. PMID:29118733

Testing Measurement Invariance across Groups of Children with and without Attention-Deficit/ Hyperactivity Disorder: Applications for Word Recognition and Spelling Tasks.

PubMed

Lúcio, Patrícia S; Salum, Giovanni; Swardfager, Walter; Mari, Jair de Jesus; Pan, Pedro M; Bressan, Rodrigo A; Gadelha, Ary; Rohde, Luis A; Cogo-Moreira, Hugo

2017-01-01

Although studies have consistently demonstrated that children with attention-deficit/hyperactivity disorder (ADHD) perform significantly lower than controls on word recognition and spelling tests, such studies rely on the assumption that those groups are comparable in these measures. This study investigates comparability of word recognition and spelling tests based on diagnostic status for ADHD through measurement invariance methods. The participants ( n = 1,935; 47% female; 11% ADHD) were children aged 6-15 with normal IQ (≥70). Measurement invariance was investigated through Confirmatory Factor Analysis and Multiple Indicators Multiple Causes models. Measurement invariance was attested in both methods, demonstrating the direct comparability of the groups. Children with ADHD were 0.51 SD lower in word recognition and 0.33 SD lower in spelling tests than controls. Results suggest that differences in performance on word recognition and spelling tests are related to true mean differences based on ADHD diagnostic status. Implications for clinical practice and research are discussed.

Texas Triaxial - R Value correlation.

DOT National Transportation Integrated Search

1963-03-01

At the time of the instigation of this research the recommended AASHO design formula was based on a Soil Support Value which directly correlated with the "R-Value" system developed by F. N. Haveem, whereas, the flexible pavement design method current...

Evaluation of FEM engineering parameters from insitu tests

DOT National Transportation Integrated Search

2001-12-01

The study looked critically at insitu test methods (SPT, CPT, DMT, and PMT) as a means for developing finite element constitutive model input parameters. The first phase of the study examined insitu test derived parameters with laboratory triaxial te...

Use of GEOGRID for Strengthening and Reducing the Roadway Structural Sections

DOT National Transportation Integrated Search

2016-01-01

An experimental laboratory program to assess the effectiveness of biaxial and triaxial geogrid-reinforced flexible pavements to reduce roadway section was carried out. Six laboratory tests were conducted using a steel cylindrical mold with dimensions...

Permeability evolution during non-linear viscous creep of porous calcite rocks

NASA Astrophysics Data System (ADS)

Xiao, X.; Evans, B.; Bernabe, Y.

2005-12-01

Below the brittle-ductile transition, permeability might be exceedingly small, due to compaction facilitated by intracrystalline plasticity or viscous creep. The ductile lower crust may consist of depth intervals or isolated domains of relatively high permeability, where the fluid pressures are at or near lithostatic values. Fluid escape from metamorphic rocks likely involves episodic hydrofracturing or porosity-wave propagation driven by the difference between the gradients of fluid and rock pressure. Although it is generally agreed that fluid flow in ductile porous rocks is critically dependent on the interplay between the fluid properties and the rheology of the rock matrix, more experimental work is needed to elucidate the ways that permeability and porosity change during deformation at elevated temperature and pressures. Triaxial tests of synthetic calcite marbles containing 10, 20, or 30 wt% quartz and up to 9% residual porosity done at temperature up to 873K, reported earlier (Xiao and Evans, 2003), indicate that shear-enhanced compaction occurs under triaxial conditions, roughly consistent with a model of void collapse by viscous creep (Budiansky et al., 1982). In this study, we report the effect of viscous creep on the permeability of those porous rocks during both isostatic and conventional triaxial loading. The tests were performed at confining pressure of 300 MPa, pore pressures between 50 to 290 MPa, temperatures from 673 to 873K and strain rates of 3.0× 10-5 s-1. Argon gas was used as the pore fluid. Under isostatic loading conditions, permeability, k, is nonlinearly related to porosity, Φ. Over small changes in porosity, the two parameters are approximately related as k~Φn. The exponent n progressively increases as the porosity decreases to a finite value, suggesting a percolation porosity. When subjected to triaxial deformation, the calcite-quartz aggregates exhibit a shear-enhanced compaction, but permeability does not decrease as rapidly as it does during isostatic conditions; the exponent n varies between 2 and 3. Non-isostatic deformation seems to reduce the percolation threshold, and, in fact, enhances the permeability relative to that at the same porosity during isostatic compaction. Our data provide constraints on the governing parameters of the compaction theory, and may have far-reaching implications for melt extraction from partially molten rocks, for the expulsion of sedimentary fluids, and for fluid flow during deformation and metamorphism.

Extraction of AE events to estimate their b values under a triaxial compressive condition Examination using continuous broadband records

NASA Astrophysics Data System (ADS)

Yoneda, N.; Kawakata, H.; Hirano, S.; Yoshimitsu, N.; Takahashi, N.

2017-12-01

Seismic b values estimated in previous laboratory compressive tests had been utilized for natural earthquake studies. Randomly sampled enough number of events over a wide magnitude range are essential for accurate b value estimation. In former triaxial tests, PZTs had sensitivity only in a narrow frequency range. In addition, the recording system could not extract all signals because of mask times or threshold setting. Recently, Yoshimitsu et al. (2014) enabled to use broadband transducers under triaxial conditions and achieved to acquire waveforms continuously in several hours. With such a system, they estimated the seismic moment of AE at very small magnitude scale. We expected that their continuous broadband recording system made it possible to record much more AE with a wider magnitude range for credible b value estimation in a laboratory. In this study, we performed a compressive test under a higher confining pressure as an updated experiment of Yoshimitsu et al. (2014) and extracted an enough amount of AE. We prepared an intact cylindrical Westerly Granite sample, 100 mm long by 50 mm in diameter. We conducted a triaxial compressive test under a confining pressure of 50 MPa, at a room temperature with drying conditions. Seven broadband transducers (sensitive range; 100 kHz - 1,000 kHz) were located in different height, respectively. Besides, a PZT was mounted to transmit elastic waves for velocity estimation during the experiment. At first, we increased the confining pressure and then started the loading. We switched the load control method from the axial load control to the circumferential displacement one. After exceeding the peak stress, compressive stress was unloaded with a high speed and the sample was recovered. A potential fault was observed on the recovered sample surface. Waveform recording was continued throughout the test for more than 200 minutes. The result of extracting signals by an STA/LTA ratio method for the waveforms recorded by each transducer, we detected about 2,170,000 signals at the most and about 450,000 at the minimum. Recorded waveforms may also include the elastic waves from the PZT and electrical noises. To find the combination of the signals derived from the same event, we used the largest differences in travel times for all transducer pairs. Finally, we obtained about 450,000 combinations.

Effect of Anisotropic Velocity Structure on Acoustic Emission Source Location during True-Triaxial Deformation Experiments

NASA Astrophysics Data System (ADS)

Ghofrani Tabari, Mehdi; Goodfellow, Sebastian; Young, R. Paul

2016-04-01

Although true-triaxial testing (TTT) of rocks is now more extensive worldwide, stress-induced heterogeneity due to the existence of several loading boundary effects is not usually accounted for and simplified anisotropic models are used. This study focuses on the enhanced anisotropic velocity structure to improve acoustic emission (AE) analysis for an enhanced interpretation of induced fracturing. Data from a TTT on a cubic sample of Fontainebleau sandstone is used in this study to evaluate the methodology. At different stages of the experiment the True-Triaxial Geophysical Imaging Cell (TTGIC), armed with an ultrasonic and AE monitoring system, performed several velocity surveys to image velocity structure of the sample. Going beyond a hydrostatic stress state (poro-elastic phase), the rock sample went through a non-dilatational elastic phase, a dilatational non-damaging elasto-plastic phase containing initial AE activity and finally a dilatational and damaging elasto-plastic phase up to the failure point. The experiment was divided into these phases based on the information obtained from strain, velocity and AE streaming data. Analysis of the ultrasonic velocity survey data discovered that a homogeneous anisotropic core in the center of the sample is formed with ellipsoidal symmetry under the standard polyaxial setup. Location of the transducer shots were improved by implementation of different velocity models for the sample starting from isotropic and homogeneous models going toward anisotropic and heterogeneous models. The transducer shot locations showed a major improvement after the velocity model corrections had been applied especially at the final phase of the experiment. This location improvement validated our velocity model at the final phase of the experiment consisting lower-velocity zones bearing partially saturated fractures. The ellipsoidal anisotropic velocity model was also verified at the core of the cubic rock specimen by AE event location of transducer shots. AE of the rock during the whole experiment recorded by the surrounding transducers were investigated by location methods developed for anisotropic heterogeneous medium where, the M-shape fracture pattern was observed. AE events occurred in the vicinity of the dilation pseudo-boundaries where, a relatively large velocity gradient was formed and along parallel fractures in the σ1/σ2 plane. This research is contributing to enhanced AE interpretation of fracture growth processes in the rock under laboratory true-triaxial stress conditions.

Full-field Strain Methods for Investigating Failure Mechanisms in Triaxial Braided Composites

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Binienda, Wieslaw K.; Goldberg, Robert K.; Roberts, Gary D.

2008-01-01

Composite materials made with triaxial braid architecture and large tow size carbon fibers are beginning to be used in many applications, including composite aircraft and engine structures. Recent advancements in braiding technology have led to commercially viable manufacturing approaches for making large structures with complex shape. Although the large unit cell size of these materials is an advantage for manufacturing efficiency, the fiber architecture presents some challenges for materials characterization, design, and analysis. In some cases, the static load capability of structures made using these materials has been higher than expected based on material strength properties measured using standard coupon tests. A potential problem with using standard tests methods for these materials is that the unit cell size can be an unacceptably large fraction of the specimen dimensions. More detailed investigation of deformation and failure processes in large unit cell size triaxial braid composites is needed to evaluate the applicability of standard test methods for these materials and to develop alternative testing approaches. In recent years, commercial equipment has become available that enables digital image correlation to be used on a more routine basis for investigation of full field 3D deformation in materials and structures. In this paper, some new techniques that have been developed to investigate local deformation and failure using digital image correlation techniques are presented. The methods were used to measure both local and global strains during standard straight-sided coupon tensile tests on composite materials made with 12 and 24 k yarns and a 0/+60/-60 triaxial braid architecture. Local deformation and failure within fiber bundles was observed, and this local failure had a significant effect on global stiffness and strength. The matrix material had a large effect on local damage initiation for the two matrix materials used in this investigation. Premature failure in regions of the unit cell near the edge of the straight-sided specimens was observed for transverse tensile tests in which the braid axial fibers were perpendicular to the specimen axis and the bias fibers terminated on the cut edges in the specimen gage section. This edge effect is one factor that could contribute to a measured strength that is lower than the actual material strength in a structure without edge effects.

Seasonal variations in urinary risk factors among patients with nephrolithiasis

NASA Technical Reports Server (NTRS)

Hill, K.; Poindexter, J.; Pak, C. Y.

1991-01-01

Twenty-four hour urine specimens from 5,677 stone-forming patients throughout the United States were analyzed for seasonal variations in urinary risk factors for nephrolithiasis. Determinations were performed for urine volume, pH, calcium, oxalate, phosphorus, sodium, magnesium, citrate, sulfate, uric acid, and the relative supersaturation (RS) of calcium oxalate, brushite, monosodium urate, and uric acid. Criteria for significant seasonal variation included a significant difference in monthly means of risk factors, seasonal grouping of the data by the Student-Newman-Keuls multiple range test, consistent year-to-year trends and a physiologically significant range. Minimum urine volume of 1.54 +/- 0.70 SD L/day occurred in October while a maximum urine volume of 1.76 +/- 0.78 SD L/day was observed during February. Minimum urine pH of 5.94 +/- 0.64 SD was observed during July and August while a maximum pH of 6.18 +/- 0.61 SD was observed during February. Daily urinary excretion of sodium was lowest during August, 158 +/- 74 SD mEq/day and highest during February 177 +/- 70 SD mEq/day. The RS of brushite and uric acid were found to display significant pH-dependent seasonal variation with a maximum RS of uric acid 2.26 +/- 1.98 SD in June and a low of 1.48 +/- 1.30 SD in February. Maximum RS of brushite 2.75 +/- 2.58 was observed during February. Minimum RS of brushite 1.93 +/- 1.70 SD was observed in June. Phosphorus excretion displayed seasonal variation about a spring-fall axis with a maximum value 1042 +/- 373 SD mg/day in April and a minimum value of 895 +/- 289 SD mg/day. Urine volume, sodium, and pH were significantly lower during the summer (June, July, August) than in the winter (December, January, February). The RS of uric acid was higher, but that of brushite and monosodium urate was lower in the summer than in the winter. The seasonal changes observed in urine volume, pH, sodium, and the RS of brushite and uric acid are consistent with summertime sweating and increased physical activity. Seasonal variations in phosphorus excretion are probably dietary in origin. The summertime was characterized by an increased propensity for the crystallization of uric acid but not of calcium oxalate or calcium phosphate.

Relationship of Adherence Determinants and Parental Spirituality in Cystic Fibrosis

PubMed Central

Grossoehme, Daniel H.; Opipari-Arrigan, Lisa; VanDyke, Rhonda; Thurmond, Sophia; Seid, Michael

2015-01-01

Summary The course of cystic fibrosis (CF) progression in children is affected by parent adherence to treatment plans. The Theory of Reasoned Action (TRA) posits that intentions are the best behavioral predictors and that intentions reasonably follow from beliefs (“determinants”). Determinants are affected by multiple “background factors,” including spirituality. This study’s purpose was to understand whether two parental adherence determinants (attitude towards treatment and self-efficacy) were associated with spirituality (religious coping and sanctification of the body). We hypothesized that parents’ attitudes toward treatment adherence are associated with these spiritual constructs. A convenience sample of parents of children with CF aged 3–12 years (n = 28) participated by completing surveys of adherence and spirituality during a regular outpatient clinic visit. Type and degree of religious coping was examined using principal component analysis. Adherence measures were compared based on religious coping styles and sanctification of the body using unpaired t-tests. Collaborative religious coping was associated with higher self-efficacy for completing airway clearance (M = 1070.8; SD = 35.8; P = 0.012), for completing aerosolized medication administration (M = 1077.1; SD = 37.4; P = 0.018), and for attitude towards treatment utility (M = 38.8; SD = 2.36; P = 0.038). Parents who attributed sacred qualities to their child’s body (e.g., “blessed” or “miraculous”) had higher mean scores for self-efficacy (airway clearance, M = 1058.6; SD = 37.7; P = 0.023; aerosols M = 1070.8; SD = 41.6; P = 0.020). Parents for whom God was manifested in their child’s body (e.g., “My child’s body is created in God’s image”) had higher mean scores for self-efficacy for airway clearance (M = 1056.4; SD = 59.0; P = 0.039), aerosolized medications (M = 1068.8; SD = 42.6; P = 0.033) and treatment utility (M = 38.8; SD = 2.4; P = 0.025). Spiritual constructs show promising significance and are currently undervalued in chronic disease management. PMID:22170872

Small dense low density lipoprotein-cholesterol and cholesterol ratios to predict arterial stiffness progression in normotensive subjects over a 5-year period.

PubMed

Li, Gang; Wu, Hui-Kun; Wu, Xiao-Wei; Cao, Zhe; Tu, Yuan-Chao; Ma, Yi; Wang, Wei-Qing; Cheng, Jian; Zhou, Zi-Hua

2018-02-12

Small dense low density lipoprotein-cholesterol (sdLDL-C), cholesterol ratios and carotid-femoral pulse wave velocity (cf-PWV) impart risk for all-cause morbidity and mortality independently of conventional cardiovascular disease (CVD) risk factors. This study was designed to identify feasible indicators for predicting arterial stiffness progression. We followed up 816 normotensive participants without diabetes or CVD for nearly 5.0 years. Cholesterol parameters, ratios and other clinical and laboratory data were collected at baseline. cf-PWV were measured at baseline and the end of follow-up. PWV progression subjects had higher levels of PWV parameters, sdLDL-C and TG/HDL-C ratio. sdLDL-C and TG/HDL-C were significantly correlated with all PWV parameters. Multiple regression models showed that sdLDL-C was closely associated with follow-up PWV (β = 0.222, p < 0.001) and △PWV (β = 0.275, p < 0.001). TG/HDL-C was only one cholesterol ratios that associated with all PWV parameters. sdLDL-C (OR = 2.070, 95%CI: 1.162 to 3.688, p = 0.014) and TG/HDL-C (OR = 1.355, 95%CI: 1.136 to 1.617, p = 0.001) could significantly determine the progression of PWV after correction for covariates. High sd-LDL-C quantiles subjects were more likely to develop arterial stiffness progression than low quantiles (Tertiles 3 vs Tertiles1, RR = 2.867, 95%CI: 1.106 to 7.434, p = 0.03). We founded that sdLDL-C and TG/HDL-C ratio can independently predict arterial stiffness progression in normotensive subjects, and high level sdLDL-C and TG/HDL-C ratio were associated with a higher risk of arterial stiffness.

Therapeutic potency of saponin rich aqueous extract of Scoparia dulcis L. in alloxan induced diabetes in rats

PubMed Central

Perumal, P. Saravana; Anaswara, P. V.; Muthuraman, A.; Krishan, S.

2014-01-01

Background: Diabetes mellitus is major metabolic disorders of carbohydrate metabolism. This leads to alter the multiple organ system. Aims: To investigate the antidiabetic and antioxidant effects of the saponin rich aqueous extract of Scoparia dulcis (SRE-SD) using alloxan-induced hyperglycemic rat model. Material and Methods: The single dose of alloxan was injected for the induction of diabetes in rats. The SRE-SD and glibenclamide were administered for 15 consecutive days from the 3rd day of alloxan administration. Quantity of food and water intake was measured at day 0, and 18. Further, body weight was recorded and blood samples were collected at different time intervals that is, day 0, 3, 8, 13, and 18. The oxidative biomarkers (i.e. thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and nitrite (NO2−) levels were also estimated in the serum sample. Results: The SRE-SD showed a remarkable dose and time-dependent changes in alloxan-induced rise in the level of food consumption and water intake, serum glucose level, TBARS, NO2− and fall in the level of GSH. Further, significant attenuation was observed at 20 and 30 mg/kg of SRE-SD treated group. Conclusions: These findings demonstrate that SRE-SD has both antidiabetic and antioxidant effects on the experimental model of diabetes in rat. PMID:25558170

Effects of a new sensory re-education training tool on hand sensibility and manual dexterity in people with multiple sclerosis.

PubMed

Kalron, Alon; Greenberg-Abrahami, Michal; Gelav, Simona; Achiron, Anat

2013-01-01

To describe and evaluate the effects of a new home-based sensory re-education training tool on hand sensibility and manual dexterity in people with MS experiencing upper limb sensory deficits. Twenty-five people with relapsing-remitting MS (18 women), mean age 50.6 years (SD = 11.4), volunteered to participate. Participants were initially assigned to a 7-week control phase followed by a 3-week home-based sensory re-education phase. Measurements used were the nine-hole peg test, the two point discrimination test, the monofilaments test and the functional dexterity test. Measurements were collected at baseline, following the control phase and at the end of the trial. Participants demonstrated an improvement in the nine-hole peg (26.8 (SD = 3.5) vs. 22.6 (SD = 3.2); mean difference (95% CI) 4.9 (0.9, 7.1), P = 0.03) and functional dexterity tests (38.6 (SD = 4.4) vs. 33.8 (SD = 4.9); mean difference (95% CI) 4.8 (1.8, 7.0); P = 0.02) at the end of the sensory re-education phase compared to the end of the control phase. No differences were observed as to the monofilaments and two-point discrimination tests. Sensory re-education training does not affect the level of sensory impairment in the hand but may lead to improvement in select measures of manual dexterity.

Growth of enstatite and enstatite-forsterite reaction rims under wet conditions during isostatic annealing and triaxial deformation

NASA Astrophysics Data System (ADS)

Helpa, Vanessa; Rybacki, Erik; Dresen, Georg

2017-04-01

To investigate the influence of differential stress and microstructure on reaction rates, we studied experimentally enstatite-forsterite double rim formation in between periclase and quartz according to the reaction MgO +

Determination of resilient properties of unbound materials with repeated load triaxial and diametral test systems.

DOT National Transportation Integrated Search

1981-12-01

Repeated load diametral test systems are experiencing increased use to determine resilient properties of asphalt concrete and admixture stabilized materials; they have not been used extensively to determine the resilient properties of unbound materia...

Use of a Web-based physical activity record system to analyze behavior in a large population: cross-sectional study.

PubMed

Namba, Hideyuki; Yamada, Yosuke; Ishida, Mika; Takase, Hideto; Kimura, Misaka

2015-03-19

The use of Web-based physical activity systems has been proposed as an easy method for collecting physical activity data. We have developed a system that has exhibited high accuracy as assessed by the doubly labeled water method. The purpose of this study was to collect behavioral data from a large population using our Web-based physical activity record system and assess the physical activity of the population based on these data. In this paper, we address the difference in physical activity for each urban scale. In total, 2046 participants (aged 30-59 years; 1105 men and 941 women) participated in the study. They were asked to complete data entry before bedtime using their personal computer on 1 weekday and 1 weekend day. Their residential information was categorized as urban, urban-rural, or rural. Participant responses expressed the intensity of each activity at 15-minute increments and were recorded on a Web server. Residential areas were compared and multiple regression analysis was performed. Most participants had a metabolic equivalent (MET) ranging from 1.4 to 1.8, and the mean MET was 1.60 (SD 0.28). The median value of moderate-to-vigorous physical activity (MVPA, ≥3 MET) was 7.92 MET-hours/day. A 1-way ANCOVA showed that total physical activity differed depending on the type of residential area (F2,2027=5.19, P=.006). The urban areas (n=950) had the lowest MET-hours/day (mean 37.8, SD, 6.0), followed by urban-rural areas (n=432; mean 38.6, SD 6.5; P=.04), and rural areas (n=664; mean 38.8, SD 7.4; P=.002). Two-way ANCOVA showed a significant interaction between sex and area of residence on the urban scale (F2,2036=4.53, P=.01). Men in urban areas had the lowest MET-hours/day (MVPA, ≥3 MET) at mean 7.9 (SD 8.7); men in rural areas had a MET-hours/day (MVPA, ≥3 MET) of mean 10.8 (SD 12.1, P=.002). No significant difference was noted in women among the 3 residential areas. Multiple regression analysis showed that physical activity consisting of standing while working was the highest contributor to MVPA, regardless of sex. We were able to compile a detailed comparison of physical activity because our Web-based physical activity record system allowed for the simultaneous evaluation of physical activity from 2046 Japanese people. We found that rural residents had greater total physical activity than urban residents and that working and transportation behaviors differed depending on region type. Multiple regression analysis showed that the behaviors affected MVPA. People are less physically active while working, and sports and active transportation might be effective ways of increasing physical activity levels.

Use of a Web-Based Physical Activity Record System to Analyze Behavior in a Large Population: Cross-Sectional Study

PubMed Central

Yamada, Yosuke; Ishida, Mika; Takase, Hideto; Kimura, Misaka

2015-01-01

Background The use of Web-based physical activity systems has been proposed as an easy method for collecting physical activity data. We have developed a system that has exhibited high accuracy as assessed by the doubly labeled water method. Objective The purpose of this study was to collect behavioral data from a large population using our Web-based physical activity record system and assess the physical activity of the population based on these data. In this paper, we address the difference in physical activity for each urban scale. Methods In total, 2046 participants (aged 30-59 years; 1105 men and 941 women) participated in the study. They were asked to complete data entry before bedtime using their personal computer on 1 weekday and 1 weekend day. Their residential information was categorized as urban, urban-rural, or rural. Participant responses expressed the intensity of each activity at 15-minute increments and were recorded on a Web server. Residential areas were compared and multiple regression analysis was performed. Results Most participants had a metabolic equivalent (MET) ranging from 1.4 to 1.8, and the mean MET was 1.60 (SD 0.28). The median value of moderate-to-vigorous physical activity (MVPA, ≥3 MET) was 7.92 MET-hours/day. A 1-way ANCOVA showed that total physical activity differed depending on the type of residential area (F2,2027=5.19, P=.006). The urban areas (n=950) had the lowest MET-hours/day (mean 37.8, SD, 6.0), followed by urban-rural areas (n=432; mean 38.6, SD 6.5; P=.04), and rural areas (n=664; mean 38.8, SD 7.4; P=.002). Two-way ANCOVA showed a significant interaction between sex and area of residence on the urban scale (F2,2036=4.53, P=.01). Men in urban areas had the lowest MET-hours/day (MVPA, ≥3 MET) at mean 7.9 (SD 8.7); men in rural areas had a MET-hours/day (MVPA, ≥3 MET) of mean 10.8 (SD 12.1, P=.002). No significant difference was noted in women among the 3 residential areas. Multiple regression analysis showed that physical activity consisting of standing while working was the highest contributor to MVPA, regardless of sex. Conclusions We were able to compile a detailed comparison of physical activity because our Web-based physical activity record system allowed for the simultaneous evaluation of physical activity from 2046 Japanese people. We found that rural residents had greater total physical activity than urban residents and that working and transportation behaviors differed depending on region type. Multiple regression analysis showed that the behaviors affected MVPA. People are less physically active while working, and sports and active transportation might be effective ways of increasing physical activity levels. PMID:25794109

Voluntary exercise impact on cognitive impairments in sleep-deprived intact female rats.

PubMed

Rajizadeh, Mohammad Amin; Esmaeilpour, Khadijeh; Masoumi-Ardakani, Yaser; Bejeshk, Mohammad Abbas; Shabani, Mohammad; Nakhaee, Nouzar; Ranjbar, Mohammad Pour; Borzadaran, Fatemeh Mohtashami; Sheibani, Vahid

2018-05-01

Sleep loss is a common problem in modern societies affecting different aspects of individuals' lives. Many studies have reported that sleep deprivation (SD) leads to impairments in various types of learning and memory. Physical exercise has been suggested to attenuate the cognitive impairments induced by sleep deprivation in male rats. Our previous studies have shown that forced exercise by treadmill improved learning and memory impairments following SD. The aim of the current study was to investigate the effects of voluntary exercise by running wheel on cognitive, motor and anxiety-like behavior functions of female rats following 72 h SD. Intact female rats were used in the present study. The multiple platform method was applied for the induction of 72 h SD. The exercise protocol was 4 weeks of running wheel and the cognitive function was evaluated using Morris water maze (MWM), passive avoidance and novel object recognition tests. Open field test and measurement of plasma corticosterone level were performed for evaluation of anxiety-like behaviors. Motor balance evaluation was surveyed by rotarod test. In this study, remarkable learning and long-term memory impairments were observed in sleep deprived rats in comparison to the other groups. Running wheel exercise ameliorated the SD-induced learning and memory impairments. Voluntary and mandatory locomotion and balance situation were not statistically significant among the different groups. Our study confirmed the negative effects of SD on cognitive function and approved protective effects of voluntary exercise on these negative effects. Copyright © 2018 Elsevier Inc. All rights reserved.

A Multi-Compartment, Single and Multiple Dose Pharmacokinetic Study of the Vaginal Candidate Microbicide 1% Tenofovir Gel

PubMed Central

Schwartz, Jill L.; Rountree, Wes; Kashuba, Angela D. M.; Brache, Vivian; Creinin, Mitchell D.; Poindexter, Alfred; Kearney, Brian P.

2011-01-01

Background Tenofovir (TFV) gel is being evaluated as a microbicide with pericoital and daily regimens. To inhibit viral replication locally, an adequate concentration in the genital tract is critical. Methods and Findings Forty-nine participants entered a two-phase study: single-dose (SD) and multi-dose (MD), were randomized to collection of genital tract samples (endocervical cells [ECC], cervicovaginal aspirate and vaginal biopsies) at one of seven time points [0.5, 1, 2, 4, 6, 8, or 24 hr(s)] post-dose following SD exposure of 4 mL 1% TFV gel and received a single dose. Forty-seven were randomized to once (QD) or twice daily (BID) dosing for 2 weeks and to collection of genital tract samples at 4, 8 or 24 hrs after the final dose, but two discontinued prior to gel application. Blood was collected during both phases at the seven times post-dose. TFV exposure was low in blood plasma for SD and MD; median Cmax was 4.0 and 3.4 ng/mL, respectively (C≤29 ng/mL). TFV concentrations were high in aspirates and tissue after SD and MD, ranging from 1.2×104 to 9.9×106 ng/mL and 2.1×102 to 1.4×106 ng/mL, respectively, and did not noticeably differ between proximal and distal tissue. TFV diphosphate (TFV-DP), the intracellular active metabolite, was high in ECC, ranging from 7.1×103 to 8.8×106 ng/mL. TFV-DP was detectable in approximately 40% of the tissue samples, ranging from 1.8×102 to 3.5×104 ng/mL. AUC for tissue TFV-DP was two logs higher after MD compared to SD, with no noticeable differences when comparing QD and BID. Conclusions Single-dose and multiple-dose TFV gel exposure resulted in high genital tract concentrations for at least 24 hours post-dose with minimal systemic absorption. These results support further study of TFV gel for HIV prevention. Trial registration ClinicalTrials.gov NCT00561496 PMID:22039430

Characterization of Shear Properties for APO/MBI Syntactic Foam

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

Reser, Patrick M.; Lewis, Matthew W.; Clark, Jarod

Triaxial compression testing is a means for mechanical characterization of a material. A unique feature of the triaxial compression test is the application of two different magnitudes of compressive pressures on the material simultaneously. The material behavior under these different compressive pressures can be monitored over time. Several important characteristics of the material, such as stress yield values and the shear failure envelope may then be determined. Also mechanical properties such as Poisson’s ratio, Young’s modulus and bulk modulus can be determined from the triaxial compression test. The triaxial compression test was employed in this investigation to characterize the shearmore » behavior, shear failure envelope, and mechanical properties of a syntactic foam. Los Alamos National Laboratory (LANL) supplied a total of 36 samples of APO-BMI syntactic foam to the University of New Mexico, Department of Civil Engineering for testing between December 2003 and May 2004. Each sample had a diameter of 1.395±0.005 in. (3.543±0.013cm.) and a length of 2.796±0.004 in. (7.102±0.010 cm.). The samples had an average density of 0.295 g/cm3. Additional information about the material tested in this investigation can be found in the “Specimen Description” section contained in Chapter 1. The nomenclatures used in this study is presented in Chapter 1. In addition to designing and implementing triaxial compression tests capable of up to 2,000 psi. confining pressure (minor principal stress) and roughly 13,000 psi. in axial pressure (major principal stress), a pure tension test was designed and conducted on the foam material. The purpose of this pure tension test was to obtain maximum tensile stress values to enhance the characterization of the shear envelope in the stress space. The sampling procedure and specimen preparation for a standard test can be found in the American Society for Testing Materials (ASTM) D 5379/ D 5379 – 93. The above tests mentioned and their procedures are discussed in Chapter 2. Chapter 2 contains the types of tests performed and the apparatus used for testing the material. Chapter 2 also has a brief explanation of the equipment and the procedures used for conducting the tests. In Chapter 3, the material characteristics and mechanical properties obtained from the tests are described; composite plots of deviatoric vs. mean stress and deviatoric stress vs. longitudinal strain are also included. The plots of deviatoric stress vs. mean stress clearly identify the shear envelope for the material. Chapter 4 summarizes the vital information obtained from the tests and the conclusions made. All the necessary plots and the data generated during the testing have been included in the Appendix. The information in the appendix includes plots of: Strain vs. Time, Stress vs. Time, Stress vs. Strain, Mean Stress vs. Volumetric Strain, Lateral Strain vs. Longitudinal Strain, and q vs. p. Bulk modulus, Poisson’s ratio, and Young’s modulus are displayed in the appropriate plots in each appendix.« less

Testing Public Anxiety Treatments against a Credible Placebo Control

ERIC Educational Resources Information Center

Duff, Desiree C.; Levine, Timothy R.; Beatty, Michael J.; Woolbright, Jessica; Park, Hee Sun

2007-01-01

Research investigating public speaking anxiety treatments is subject to demand effects. This study tests the relative effectiveness of systematic desensitization (SD) and multiple treatment method (MT) containing visualization therapy against no-treatment and credible placebo controls. Data (N = 238) were collected at six points in a public…

Active Games: An Approach to Teaching Mathematical Skills to the Educable Mentally Retarded

ERIC Educational Resources Information Center

Taylor, George R.; Watkins, Susan T.

1974-01-01

Several games involving both motor behavior and practice with mathematical skills are described. These include adaptations of musical chairs (subtraction), call ball (multiplication), and ring toss (linear measurement); other games are designed to provide practice on identifying numerals, telling time, using money, and naming fractions. (SD)

Speckle interferometry applied to asteroids and other solar system objects

NASA Technical Reports Server (NTRS)

Drummond, J. D.; Hege, E. K.

1985-01-01

The application of speckle interferometry to asteroids and other solar system objects is discussed. The assumption of a triaxial ellipsoid rotating about its shortest axis is the standard model. Binary asteroids, 433 Eros, 532 Herculina, 511 Davida, and Pallas are discussed.

Real-time positioning technology in horizontal directional drilling based on magnetic gradient tensor measurement

NASA Astrophysics Data System (ADS)

Deng, Guoqing; Yao, Aiguo

2017-04-01

Horizontal directional drilling (HDD) technology has been widely used in Civil Engineering. The dynamic position of the drill bit during construction is one of significant facts determining the accuracy of the trajectory of HDD. A new method now has been proposed to detecting the position of drill bit by measuring the magnetic gradient tensor of the ground solenoid magnetic beacon. Compared with traditional HDD positioning technologies, this new model is much easier to apply with lower request for construction sites and higher positioning efficiency. A direct current (DC) solenoid as a magnetic dipole is placed on ground near the drill bit, and related sensors array which contains four Micro-electromechanical Systems (MEMS ) tri-axial magnetometers, one MEMS tri-axial accelerometer and one MEMS tri-axial gyroscope is set up for measuring the magnetic gradient tensor of the magnetic dipole. The related HDD positioning model has been established and simulation experiments have been carried out to verify the feasibility and reliability of the proposed method. The experiments show that this method has good positioning accuracy in horizontal and vertical direction, and totally avoid the impact of the environmental magnetic field. It can be found that the posture of the magnetic beacon will impact the remote positioning precision within valid positioning range, and the positioning accuracy is higher with longer baseline for limited space in drilling tools. The results prove that the relative error can be limited in 2% by adjusting position of the magnetic beacon, the layers of the enameled coil, the sensitive of magnetometers and the baseline distance. Conclusion can be made that this new method can be applied in HDD positioning with better effect and wider application range than traditional method.

The Evolution of the Globular Cluster System in a Triaxial Galaxy: Can a Galactic Nucleus Form by Globular Cluster Capture?

NASA Astrophysics Data System (ADS)

Capuzzo-Dolcetta, Roberto

1993-10-01

Among the possible phenomena inducing evolution of the globular cluster system in an elliptical galaxy, dynamical friction due to field stars and tidal disruption caused by a central nucleus is of crucial importance. The aim of this paper is the study of the evolution of the globular cluster system in a triaxial galaxy in the presence of these phenomena. In particular, the possibility is examined that some galactic nuclei have been formed by frictionally decayed globular clusters moving in a triaxial potential. We find that the initial rapid growth of the nucleus, due mainly to massive clusters on box orbits falling in a short time scale into the galactic center, is later slowed by tidal disruption induced by the nucleus itself on less massive clusters in the way described by Ostriker, Binney, and Saha. The efficiency of dynamical friction is such to carry to the center of the galaxy enough globular cluster mass available to form a compact nucleus, but the actual modes and results of cluster-cluster encounters in the central potential well are complicated phenomena which remains to be investigated. The mass of the resulting nucleus is determined by the mutual feedback of the described processes, together with the initial spatial, velocity, and mass distributions of the globular cluster family. The effect on the system mass function is studied, showing the development of a low- and high-mass turnover even with an initially flat mass function. Moreover, in this paper is discussed the possibility that the globular cluster fall to the galactic center has been a cause of primordial violent galactic activity. An application of the model to M31 is presented.

Three-dimensional forward modeling and inversion of marine CSEM data in anisotropic conductivity structures

NASA Astrophysics Data System (ADS)

Han, B.; Li, Y.

2016-12-01

We present a three-dimensional (3D) forward and inverse modeling code for marine controlled-source electromagnetic (CSEM) surveys in anisotropic media. The forward solution is based on a primary/secondary field approach, in which secondary fields are solved using a staggered finite-volume (FV) method and primary fields are solved for 1D isotropic background models analytically. It is shown that it is rather straightforward to extend the isotopic 3D FV algorithm to a triaxial anisotropic one, while additional coefficients are required to account for full tensor conductivity. To solve the linear system resulting from FV discretization of Maxwell' s equations, both iterative Krylov solvers (e.g. BiCGSTAB) and direct solvers (e.g. MUMPS) have been implemented, makes the code flexible for different computing platforms and different problems. For iterative soloutions, the linear system in terms of electromagnetic potentials (A-Phi) is used to precondition the original linear system, transforming the discretized Curl-Curl equations to discretized Laplace-like equations, thus much more favorable numerical properties can be obtained. Numerical experiments suggest that this A-Phi preconditioner can dramatically improve the convergence rate of an iterative solver and high accuracy can be achieved without divergence correction even for low frequencies. To efficiently calculate the sensitivities, i.e. the derivatives of CSEM data with respect to tensor conductivity, the adjoint method is employed. For inverse modeling, triaxial anisotropy is taken into account. Since the number of model parameters to be resolved of triaxial anisotropic medias is twice or thrice that of isotropic medias, the data-space version of the Gauss-Newton (GN) minimization method is preferred due to its lower computational cost compared with the traditional model-space GN method. We demonstrate the effectiveness of the code with synthetic examples.

Calculation of multidimensional potential energy surfaces for even-even transuranium nuclei: systematic investigation of the triaxiality effect on the fission barrier

NASA Astrophysics Data System (ADS)

Chai, Qing-Zhen; Zhao, Wei-Juan; Liu, Min-Liang; Wang, Hua-Lei

2018-05-01

Static fission barriers for 95 even-even transuranium nuclei with charge number Z = 94–118 have been systematically investigated by means of pairing self-consistent Woods-Saxon-Strutinsky calculations using the potential energy surface approach in multidimensional (β 2, γ, β 4) deformation space. Taking the heavier 252Cf nucleus (with the available fission barrier from experiment) as an example, the formation of the fission barrier and the influence of macroscopic, shell and pairing correction energies on it are analyzed. The results of the present calculated β 2 values and barrier heights are compared with previous calculations and available experiments. The role of triaxiality in the region of the first saddle is discussed. It is found that the second fission barrier is also considerably affected by the triaxial deformation degree of freedom in some nuclei (e.g., the Z=112–118 isotopes). Based on the potential energy curves, general trends of the evolution of the fission barrier heights and widths as a function of the nucleon numbers are investigated. In addition, the effects of Woods-Saxon potential parameter modifications (e.g., the strength of the spin-orbit coupling and the nuclear surface diffuseness) on the fission barrier are briefly discussed. Supported by National Natural Science Foundation of China (11675148, 11505157), the Project of Youth Backbone Teachers of Colleges and Universities of Henan Province (2017GGJS008), the Foundation and Advanced Technology Research Program of Henan Province (162300410222), the Outstanding Young Talent Research Fund of Zhengzhou University (1521317002) and the Physics Research and Development Program of Zhengzhou University (32410017)

Critical Void Volume Fraction fc at Void Coalescence for S235JR Steel at Low Initial Stress Triaxiality

NASA Astrophysics Data System (ADS)

Grzegorz Kossakowski, Paweł; Wciślik, Wiktor

2017-10-01

The paper is concerned with the nucleation, growth and coalescence of microdefects in the form of voids in S235JR steel. The material is known to be one of the basic steel grades commonly used in the construction industry. The theory and methods of damage mechanics were applied to determine and describe the failure mechanisms that occur when the material undergoes deformation. Until now, engineers have generally employed the Gurson-Tvergaard- Needleman model. This material model based on damage mechanics is well suited to define and analyze failure processes taking place in the microstructure of S235JR steel. It is particularly important to determine the critical void volume fraction fc , which is one of the basic parameters of the Gurson-Tvergaard-Needleman material model. As the critical void volume fraction fc refers to the failure stage, it is determined from the data collected for the void coalescence phase. A case of multi-axial stresses is considered taking into account the effects of spatial stress state. In this study, the parameter of stress triaxiality η was used to describe the failure phenomena. Cylindrical tensile specimens with a circumferential notch were analysed to obtain low values of initial stress triaxiality (η = 0.556 of the range) in order to determine the critical void volume fraction fc . It is essential to emphasize how unique the method applied is and how different it is from the other more common methods involving parameter calibration, i.e. curve-fitting methods. The critical void volume fraction fc at void coalescence was established through digital image analysis of surfaces of S235JR steel, which involved studying real, physical results obtained directly from the material tested.

High Speed Thermal Imaging on Ballistic Impact of Triaxially Braided Composites

NASA Technical Reports Server (NTRS)

Johnston, Joel P.; Pereira, J. Michael; Ruggeri, Charles R.; Roberts, Gary D.

2017-01-01

Ballistic impact experiments were performed on triaxially braided polymer matrix composites to study the heat generated in the material due to projectile velocity and penetration damage. Quantifying the heat generation phenomenon is crucial for attaining a better understanding of composite behavior and failure under impact loading. The knowledge gained can also be used to improve physics-based models which can numerically simulate impact of composites. Triaxially braided (0/+60/-60) composite panels were manufactured with T700S standard modulus carbon fiber and two epoxy resins. The PR520 (toughened) and 3502 (untoughened) resin systems were used to make different panels to study the effects of resin properties on temperature rise. Ballistic impact tests were conducted on these composite panels using a gas gun, and different projectile velocities were applied to study the effect on the temperature results. Temperature contours were obtained from the rear surface of the panel during the test through a high speed, infrared (IR) thermal imaging system. The contours show that high temperatures were locally generated and more pronounced along the axial tows for the T700S/PR520 composite specimens; whereas, tests performed on T700S/3502 composite panels using similar impact velocities demonstrated a widespread area of lower temperature rises. Nondestructive, ultrasonic C-scan analyses were performed to observe and verify the failure patterns in the impacted panels. Overall, the impact experimentation showed temperatures exceeding 525 K (485degF) in both composites which is well above the respective glass transition temperatures for the polymer constituents. This expresses the need for further high strain rate testing and measurement of the temperature and deformation fields to fully understand the complex behavior and failure of the material in order to improve the confidence in designing aerospace components with these materials.

Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

NASA Astrophysics Data System (ADS)

Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

2015-12-01

Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

Experiment Evaluation of Bifurcation in Sands

NASA Technical Reports Server (NTRS)

Alshibi, Khalid A.; Sture, Stein

2000-01-01

The basic principles of bifurcation analysis have been established by several investigators, however several issues remain unresolved, specifically how do stress level, grain size distribution, and boundary conditions affect general bifurcation phenomena in pressure sensitive and dilatant materials. General geometrical and kinematics conditions for moving surfaces of discontinuity was derived and applied to problems of instability of solids. In 1962, the theoretical framework of bifurcation by studying the acceleration waves in elasto-plastic (J2) solids were presented. Bifurcation analysis for more specific forms of constitutive behavior was examined by studying localization in pressure-sensitive, dilatant materials, however, analyses were restricted to plane deformation states only. Bifurcation analyses were presented and applied to predict shear band formations in sand under plane strain condition. The properties of discontinuous bifurcation solutions for elastic-plastic solids under axisymmetric and plane strain loading conditions were studied. The study focused on theory, but also references and comparisons to experiments were made. The current paper includes a presentation of a summary of bifurcation analyses for biaxial and triaxial (axisymmetric) loading conditions. The Coulomb model is implemented using incremental piecewise scheme to predict the constitutive relations and shear band inclination angles. Then, a comprehensive evaluation of bifurcation phenomena is presented based on data from triaxial experiments performed under microgravity conditions aboard the Space Shuttle under very low effective confining pressure (0.05 to 1.30 kPa), in which very high peak friction angles (47 to 75 degrees) and dilatancy angles (30 to 31 degrees) were measured. The evaluation will be extended to include biaxial experiments performed on the same material under low (10 kPa) and moderate (100 kPa) confining pressures. A comparison between the behavior under biaxial and triaxial loading conditions will be presented, and related issues concerning influence of confining pressure will be discussed.

Compaction behavior of surrogate degraded emplaced WIPP waste.

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

Broome, Scott Thomas; Bronowski, David R.; Kuthakun, Souvanny James

The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of degraded Waste Isolation Pilot Plant (WIPP) containers and TRU waste materials at the end of the 10,000 year regulatory period. Testing consists of hydrostatic, triaxial, and uniaxial strain tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, andmore » rubbers (CPR). Axial, lateral, and volumetric strain and axial, lateral, and pore stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk moduli of the samples measured using this technique were consistent with those measured using more conventional methods. The second technique involved performing triaxial tests under lateral strain control. By limiting the lateral strain to zero by controlling the applied confining pressure while loading the specimen axially in compression, one can maintain a right-circular cylindrical geometry even under large deformations. This technique is preferred over standard triaxial testing methods which result in inhomogeneous deformation or (3z(Bbarreling(3y. (BManifestations of the inhomogeneous deformation included non-uniform stress states, as well as unrealistic Poissons ratios (> 0.5) or those that vary significantly along the length of the specimen. Zero lateral strain controlled tests yield a more uniform stress state, and admissible and uniform values of Poissons ratio.« less

Serum and Wound Vancomycin Levels After Intrawound Administration in Primary Total Joint Arthroplasty.

PubMed

Johnson, Jeremiah D; Nessler, Joseph M; Horazdovsky, Ryan D; Vang, Sandy; Thomas, Avis J; Marston, Scott B

2017-03-01

Periprosthetic joint infection is the most common cause of readmissions after total joint arthroplasty (TJA). Intrawound vancomycin powder (VP) has reduced infection rates in spine surgery; however, there are no data regarding VP in primary TJA. Thirty-four TJA patients received 2 g of VP intraoperatively to investigate VP's pharmacokinetics. Serum and wound concentrations were measured at multiple intervals over 24 hours after closure. All serum concentrations were subtherapeutic (<15μg/mL) and peaked 12 hours after closure (4.7μg/mL; standard deviation [SD], 3.2). Wound concentrations were 922 μg/mL (SD, 523) 3 hours after closure and 207 μg/mL (SD, 317) at 24 hours. VP had a half-life of 7.2 hours (95% confidence interval, 7.0-9.3) in TJA wounds. VP produced highly therapeutic intrawound concentrations while yielding low systemic levels in TJA. VP may serve as a safe adjunct in the prevention of periprosthetic joint infection. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantification of intravoxel velocity standard deviation and turbulence intensity by generalizing phase-contrast MRI.

PubMed

Dyverfeldt, Petter; Sigfridsson, Andreas; Kvitting, John-Peder Escobar; Ebbers, Tino

2006-10-01

Turbulent flow, characterized by velocity fluctuations, is a contributing factor to the pathogenesis of several cardiovascular diseases. A clinical noninvasive tool for assessing turbulence is lacking, however. It is well known that the occurrence of multiple spin velocities within a voxel during the influence of a magnetic gradient moment causes signal loss in phase-contrast magnetic resonance imaging (PC-MRI). In this paper a mathematical derivation of an expression for computing the standard deviation (SD) of the blood flow velocity distribution within a voxel is presented. The SD is obtained from the magnitude of PC-MRI signals acquired with different first gradient moments. By exploiting the relation between the SD and turbulence intensity (TI), this method allows for quantitative studies of turbulence. For validation, the TI in an in vitro flow phantom was quantified, and the results compared favorably with previously published laser Doppler anemometry (LDA) results. This method has the potential to become an important tool for the noninvasive assessment of turbulence in the arterial tree.

White matter microstructural alterations in clinically isolated syndrome and multiple sclerosis.

PubMed

Huang, Jing; Liu, Yaou; Zhao, Tengda; Shu, Ni; Duan, Yunyun; Ren, Zhuoqiong; Sun, Zheng; Liu, Zheng; Chen, Hai; Dong, Huiqing; Li, Kuncheng

2018-07-01

This study aims to determine whether and how diffusion alteration occurs in the earliest stage of multiple sclerosis (MS) and the differences in diffusion metrics between CIS and MS by using the tract-based spatial statistics (TBSS) method based on diffusion tensor imaging (DTI). Thirty-six CIS patients (mean age ± SD: 34.0 years ± 12.6), 36 relapsing-remitting multiple sclerosis (RRMS) patients (mean age ± SD: 35.0 years ± 9.4) and 36 age- and gender-matched normal controls (NCs) were included in this study. Voxel-wise analyses were performed with TBSS using multiple diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ 1 ) and radial diffusivity (λ 23 ). In the CIS patients, TBSS analyses revealed diffusion alterations in a few white matter (WM) regions including the anterior thalamic radiation, corticospinal tract, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, body and splenium of the corpus callosum, internal capsule, external capsule, and cerebral peduncle. MS patients showed more widespread diffusion changes (decreased FA, increased λ 1 , λ 23 and MD) than CIS. Exploratory analyses also revealed the possible associations between WM diffusion metrics and clinical variables (Expanded Disability Status Scale and disease duration) in the patients. This study provided imaging evidence for DTI abnormalities in CIS and MS and suggested that DTI can improve our knowledge of the path physiology of CIS and MS and clinical progression. Copyright © 2018 Elsevier Ltd. All rights reserved.

Multiple loci and epistases control genetic variation for seed dormancy in weedy rice (Oryza sativa).

PubMed Central

Gu, Xing-You; Kianian, Shahryar F; Foley, Michael E

2004-01-01

Weedy rice has much stronger seed dormancy than cultivated rice. A wild-like weedy strain SS18-2 was selected to investigate the genetic architecture underlying seed dormancy, a critical adaptive trait in plants. A framework genetic map covering the rice genome was constructed on the basis of 156 BC(1) [EM93-1 (nondormant breeding line)//EM93-1/SS18-2] individuals. The mapping population was replicated using a split-tiller technique to control and better estimate the environmental variation. Dormancy was determined by germination of seeds after 1, 11, and 21 days of after-ripening (DAR). Six dormancy QTL, designated as qSD(S)-4, -6, -7-1, -7-2, -8, and -12, were identified. The locus qSD(S)-7-1 was tightly linked to the red pericarp color gene Rc. A QTL x DAR interaction was detected for qSD(S)-12, the locus with the largest main effect at 1, 11, and 21 DAR (R(2) = 0.14, 0.24, and 0.20, respectively). Two, three, and four orders of epistases were detected with four, six, and six QTL, respectively. The higher-order epistases strongly suggest the presence of genetically complex networks in the regulation of variation for seed dormancy in natural populations and make it critical to select for a favorable combination of alleles at multiple loci in positional cloning of a target dormancy gene. PMID:15082564

Fiber reinforced sandy slopes under groundwater return flow

USDA-ARS?s Scientific Manuscript database

The instability of natural hillslopes, riverbanks and engineered embankments due to seepage has been a major concern. In an effort to prevent failures, tension resisting synthetic fibers may be an effective additive to increase the mechanical properties of engineered soils. In this study, triaxial c...

Novel Δ J =1 Sequence in 78Ge: Possible Evidence for Triaxiality

NASA Astrophysics Data System (ADS)

Forney, A. M.; Walters, W. B.; Chiara, C. J.; Janssens, R. V. F.; Ayangeakaa, A. D.; Sethi, J.; Harker, J.; Alcorta, M.; Carpenter, M. P.; Gürdal, G.; Hoffman, C. R.; Kay, B. P.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Rogers, A. M.; Seweryniak, D.; Stefanescu, I.; Zhu, S.

2018-05-01

A sequence of low-energy levels in Ge783246 has been identified with spins and parity of 2+, 3+, 4+, 5+, and 6+. Decays within this band proceed strictly through Δ J =1 transitions, unlike similar sequences in neighboring Ge and Se nuclei. Above the 2+ level, members of this sequence do not decay into the ground-state band. Moreover, the energy staggering of this sequence has the phase that would be expected for a γ -rigid structure. The energies and branching ratios of many of the levels are described well by shell-model calculations. However, the calculated reduced transition probabilities for the Δ J =2 in-band transitions imply that they should have been observed, in contradiction with the experiment. Within the calculations of Davydov, Filippov, and Rostovsky for rigid-triaxial rotors with γ =3 0 ° , there are sequences of higher-spin levels connected by strong Δ J =1 transitions which decay in the same manner as those observed experimentally, yet are calculated at too high an excitation energy.

Crack Damage Parameters and Dilatancy of Artificially Jointed Granite Samples Under Triaxial Compression

NASA Astrophysics Data System (ADS)

Walton, G.; Alejano, L. R.; Arzua, J.; Markley, T.

2018-06-01

A database of post-peak triaxial test results was created for artificially jointed planes introduced in cylindrical compression samples of a Blanco Mera granite. Aside from examining the artificial jointing effect on major rock and rock mass parameters such as stiffness, peak strength and residual strength, other strength parameters related to brittle cracking and post-yield dilatancy were analyzed. Crack initiation and crack damage values for both the intact and artificially jointed samples were determined, and these damage envelopes were found to be notably impacted by the presence of jointing. The data suggest that with increased density of jointing, the samples transition from a combined matrix damage and joint slip yielding mechanism to yield dominated by joint slip. Additionally, post-yield dilation data were analyzed in the context of a mobilized dilation angle model, and the peak dilation angle was found to decrease significantly when there were joints in the samples. These dilatancy results are consistent with hypotheses in the literature on rock mass dilatancy.

Uniformly rotating, axisymmetric, and triaxial quark stars in general relativity

NASA Astrophysics Data System (ADS)

Zhou, Enping; Tsokaros, Antonios; Rezzolla, Luciano; Xu, Renxin; Uryū, Kōji

2018-01-01

Quasiequilibrium models of uniformly rotating axisymmetric and triaxial quark stars are computed in a general-relativistic gravity scenario. The Isenberg-Wilson-Mathews (IWM) formulation is employed and the Compact Object Calculator (cocal) code is extended to treat rotating stars with finite surface density and new equations of state (EOSs). Besides the MIT bag model for quark matter which is composed of deconfined quarks, we examine a new EOS proposed by Lai and Xu that is based on quark clustering and results in a stiff EOS that can support masses up to 3.3 M⊙ in the case we considered. We perform convergence tests for our new code to evaluate the effect of finite surface density in the accuracy of our solutions and construct sequences of solutions for both small and high compactness. The onset of secular instability due to viscous dissipation is identified and possible implications are discussed. An estimate of the gravitational wave amplitude and luminosity based on quadrupole formulas is presented and comparison with neutron stars is discussed.

Exact density-potential pairs from complex-shifted axisymmetric systems

NASA Astrophysics Data System (ADS)

Ciotti, Luca; Marinacci, Federico

2008-07-01

In a previous paper, the complex-shift method has been applied to self-gravitating spherical systems, producing new analytical axisymmetric density-potential pairs. We now extend the treatment to the Miyamoto-Nagai disc and the Binney logarithmic halo, and we study the resulting axisymmetric and triaxial analytical density-potential pairs; we also show how to obtain the surface density of shifted systems from the complex shift of the surface density of the parent model. In particular, the systems obtained from Miyamoto-Nagai discs can be used to describe disc galaxies with a peanut-shaped bulge or with a central triaxial bar, depending on the direction of the shift vector. By using a constructive method that can be applied to generic axisymmetric systems, we finally show that the Miyamoto-Nagai and the Satoh discs, and the Binney logarithmic halo cannot be obtained from the complex shift of any spherical parent distribution. As a by-product of this study, we also found two new generating functions in closed form for even and odd Legendre polynomials, respectively.

Ductile Crack Initiation Criterion with Mismatched Weld Joints Under Dynamic Loading Conditions.

PubMed

An, Gyubaek; Jeong, Se-Min; Park, Jeongung

2018-03-01

Brittle failure of high toughness steel structures tends to occur after ductile crack initiation/propagation. Damages to steel structures were reported in the Hanshin Great Earthquake. Several brittle failures were observed in beam-to-column connection zones with geometrical discontinuity. It is widely known that triaxial stresses accelerate the ductile fracture of steels. The study examined the effects of geometrical heterogeneity and strength mismatches (both of which elevate plastic constraints due to heterogeneous plastic straining) and loading rate on critical conditions initiating ductile fracture. This involved applying the two-parameter criterion (involving equivalent plastic strain and stress triaxiality) to estimate ductile cracking for strength mismatched specimens under static and dynamic tensile loading conditions. Ductile crack initiation testing was conducted under static and dynamic loading conditions using circumferentially notched specimens (Charpy type) with/without strength mismatches. The results indicated that the condition for ductile crack initiation using the two parameter criterion was a transferable criterion to evaluate ductile crack initiation independent of the existence of strength mismatches and loading rates.

Assessment of the Mechanical Properties of Sisal Fiber-Reinforced Silty Clay Using Triaxial Shear Tests

PubMed Central

Wu, Yankai; Li, Yanbin; Niu, Bin

2014-01-01

Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of soil because it increases the soil's strength and improves the soil's mechanical properties. However, the mechanical properties of fiber-reinforced soils remain controversial. The present study investigated the mechanical properties of silty clay reinforced with discrete, randomly distributed sisal fibers using triaxial shear tests. The sisal fibers were cut to different lengths, randomly mixed with silty clay in varying percentages, and compacted to the maximum dry density at the optimum moisture content. The results indicate that with a fiber length of 10 mm and content of 1.0%, sisal fiber-reinforced silty clay is 20% stronger than nonreinforced silty clay. The fiber-reinforced silty clay exhibited crack fracture and surface shear fracture failure modes, implying that sisal fiber is a good earth reinforcement material with potential applications in civil engineering, dam foundation, roadbed engineering, and ground treatment. PMID:24982951

Effect of water on the triaxial response under monotonic loading of asphalt concrete used in dams

NASA Astrophysics Data System (ADS)

Gaxiola Hernández, Alberto; Ossa López, Alexandra

2018-01-01

Embankment dams with asphalt concrete cores have been constructed on practically all continents with satisfactory results. Nowadays many advantages, such as the mechanical strength, are known that makes asphalt concrete a competitive alternative for the construction of the impervious elements of dams. However, the current available information does not describe the effect of prolonged contact between asphalt concrete and water on the structure of an embankment dam. In this research cylindrical asphalt concrete specimens with a void content similar to that used in impervious barriers of dams were fabricated and submerged in water for a prolonged period to simulate the conditions experienced by asphalt concrete placed inside an embankment dam as its core material. Subsequently, triaxial compression tests were conducted on the specimens. The results indicated that the asphalt concrete exhibited a reduction in strength because of the saturation process to which the material was subjected. However, no changes were observed in the mechanical response to prolonged contact with water for periods of up to 12 months.

Biomechanics of head injury in olympic taekwondo and boxing.

PubMed

Fife, G P; O'Sullivan, D; Pieter, W

2013-12-01

The purpose was to examine differences between taekwondo kicks and boxing punches in resultant linear head acceleration (RLA), head injury criterion (HIC15), peak head velocity, and peak foot and fist velocities. Data from two existing publications on boxing punches and taekwondo kicks were compared. For taekwondo head impacts a Hybrid II Crash Dummy (Hybrid II) head was instrumented with a tri-axial accelerometer mounted inside the Hybrid II head. The Hybrid II was fixed to a height-adjustable frame and fitted with a protective taekwondo helmet. For boxing testing, a Hybrid III Crash Dummy head was instrumented with an array of tri-axial accelerometers mounted at the head centre of gravity. Differences in RLA between the roundhouse kick (130.11±51.67 g) and hook punch (71.23±32.19 g, d = 1.39) and in HIC15 (clench axe kick: 162.63±104.10; uppercut: 24.10±12.54, d = 2.29) were observed. Taekwondo kicks demonstrated significantly larger magnitudes than boxing punches for both RLA and HIC.

FORGE Milford Triaxial Test Data and Summary from EGI labs

DOE Data Explorer

Joe Moore

2016-03-01

Six samples were evaluated in unconfined and triaxial compression, their data are included in separate excel spreadsheets, and summarized in the word document. Three samples were plugged along the axis of the core (presumed to be nominally vertical) and three samples were plugged perpendicular to the axis of the core. A designation of "V"indicates vertical or the long axis of the plugged sample is aligned with the axis of the core. Similarly, "H" indicates a sample that is nominally horizontal and cut orthogonal to the axis of the core. Stress-strain curves were made before and after the testing, and are included in the word doc.. The confining pressure for this test was 2800 psi. A series of tests are being carried out on to define a failure envelope, to provide representative hydraulic fracture design parameters and for future geomechanical assessments. The samples are from well 52-21, which reaches a maximum depth of 3581 ft +/- 2 ft into a gneiss complex.

Nuclear Structure in 78Ge

NASA Astrophysics Data System (ADS)

Forney, Anne M.; Walters, W. B.; Sethi, J.; Chiara, C. J.; Harker, J.; Janssens, R. V. F.; Zhu, S.; Carpenter, M.; Alcorta, M.; Gürdal, G.; Hoffman, C. R.; Kay, B. P.; Kondev, F. G.; Lauristen, T.; Lister, C. J.; McCutchan, E. A.; Rogers, A. M.; Seweryniak, D.

2017-01-01

Owing to the importance of the structure of 76Ge in interpreting double β decay studies, the structures of adjacent nuclei have been of considerable interest. Recently reported features for the structures of 72,74,76Ge indicate both shape coexistence and triaxiality. New data for the excited states of 78Ge will be reported arising from Gammasphere studies of multinucleon transfer reactions between a 76Ge beam and thick heavy targets at the ATLAS facility at Argonne National Laboratory. The previously known yrast band is extended to higher spins, candidate levels for a triaxial sequence have been observed, and the associated staggering determined. The staggering in 78Ge found in this work is not in agreement with theoretical work. Candidates for negative-parity states and seniority-four states will be discussed. This material is based upon work supported by the U.S. DOE under DE-AC02-06CH11357 and DE-FG02-94ER40834. Resources of ANL's ATLAS setup, a DOE Office of Science user facility, were used.

Finite Element Model for Failure Study of Two-Dimensional Triaxially Braided Composite

NASA Technical Reports Server (NTRS)

Li, Xuetao; Binienda, Wieslaw K.; Goldberg, Robert K.

2010-01-01

A new three-dimensional finite element model of two-dimensional triaxially braided composites is presented in this paper. This meso-scale modeling technique is used to examine and predict the deformation and damage observed in tests of straight sided specimens. A unit cell based approach is used to take into account the braiding architecture as well as the mechanical properties of the fiber tows, the matrix and the fiber tow-matrix interface. A 0 deg / plus or minus 60 deg. braiding configuration has been investigated by conducting static finite element analyses. Failure initiation and progressive degradation has been simulated in the fiber tows by use of the Hashin failure criteria and a damage evolution law. The fiber tow-matrix interface was modeled by using a cohesive zone approach to capture any fiber-matrix debonding. By comparing the analytical results to those obtained experimentally, the applicability of the developed model was assessed and the failure process was investigated.

True Triaxial Failure of Granite: Implications for Deep Borehole Waste Disposal

NASA Astrophysics Data System (ADS)

Williams, M.; Ingraham, M. D.; Cheung, C.; Haimson, B. C.

2016-12-01

A series of tests have been completed to determine the failure of Sierra White Granite under a range of true triaxial stress conditions ranging from axisymmetric compression to axisymmetric extension. Tests were performed under constant mean stress conditions. Results show a significant difference in failure due to the intermediate principal stress. Borehole breakout, a significant issue for deep borehole disposal, occurs in line with the least principal stress, which in the United States at great depth is almost certainly a horizontal stress. This means that any attempt to dispose of waste in deep boreholes will have to overcome this phenomenon. This work seeks to determine the full 3D failure surface for granite such that it can be applied to determining the likelihood of borehole breakout occurring under different stress conditions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Assessment of mechanical strain in the intact plantar fascia.

PubMed

Clark, Ross A; Franklyn-Miller, Andrew; Falvey, Eanna; Bryant, Adam L; Bartold, Simon; McCrory, Paul

2009-09-01

A method of measuring tri-axial plantar fascia strain that is minimally affected by external compressive force has not previously been reported. The purpose of this study was to assess the use of micro-strain gauges to examine strain in the different axes of the plantar fascia. Two intact limbs from a thawed, fresh-frozen cadaver were dissected, and a combination of five linear and one three-way rosette gauges were attached to the fascia of the foot and ankle. Strain was assessed during two trials, both consisting of an identical controlled, loaded dorsiflexion. An ICC analysis of the results revealed that the majority of gauge placement sites produced reliable measures (ICC>0.75). Strain mapping of the plantar fascia indicates that the majority of the strain is centrally longitudinal, which provides supportive evidence for finite element model analysis. Although micro-strain gauges do possess the limitation of calibration difficulty, they provide a repeatable measure of fascial strain and may provide benefits in situations that require tri-axial assessment or external compression.

Analysis of woven and braided fabric reinforced composites

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

A triaxial accelerometer-based physical-activity recognition via augmented-signal features and a hierarchical recognizer.

PubMed

Khan, Adil Mehmood; Lee, Young-Koo; Lee, Sungyoung Y; Kim, Tae-Seong

2010-09-01

Physical-activity recognition via wearable sensors can provide valuable information regarding an individual's degree of functional ability and lifestyle. In this paper, we present an accelerometer sensor-based approach for human-activity recognition. Our proposed recognition method uses a hierarchical scheme. At the lower level, the state to which an activity belongs, i.e., static, transition, or dynamic, is recognized by means of statistical signal features and artificial-neural nets (ANNs). The upper level recognition uses the autoregressive (AR) modeling of the acceleration signals, thus, incorporating the derived AR-coefficients along with the signal-magnitude area and tilt angle to form an augmented-feature vector. The resulting feature vector is further processed by the linear-discriminant analysis and ANNs to recognize a particular human activity. Our proposed activity-recognition method recognizes three states and 15 activities with an average accuracy of 97.9% using only a single triaxial accelerometer attached to the subject's chest.

The surfaces of Larissa and Proteus

NASA Astrophysics Data System (ADS)

Stooke, Philip J.

1994-01-01

Topographic models of Neptune's small inner satellites Larissa and Proteus were derived from the shapes of limbs and terminators in Voyager images, modified locally to accomodate large craters and ridges. The models are presented here in tabular and graphic form, including the first map of Larissa and the first detailed relief map of Proteus. The shape of Larissa is approximated by a triaxial ellipsoid with axes of 208, 192 and 178 km, but is only weakly constrained by the single available view. The volume is estimated to be 3.5 +/- 1.0 x 106cu km. The surface is heavily cratered and may be crossed by one or two poorly seen linear ridges. Proteus is approximated by a triaxial ellipsoid with axes of 424, 390 and 396 km (the latter being the rotation axis dimension). The volume is estimated to be 3.4 +/- 0.4 x 107 cu km. Its surface appears to be very heavily cratered and extensive evidence for linear fractures is observed despite very low image quality.

Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion

NASA Astrophysics Data System (ADS)

Wu, Jing; Waldstein, Sebastian M.; Gerendas, Bianca S.; Langs, Georg; Simader, Christian; Schmidt-Erfurth, Ursula

2015-03-01

Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high- resolution, three-dimensional (3D) cross-sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD), glaucoma and retinal vein occlusion (RVO). Disease diagnosis, assessment, and treatment will require a patient to undergo multiple OCT scans, possibly using multiple scanners, to accurately and precisely gauge disease activity, progression and treatment success. However, cross-vendor imaging and patient movement may result in poor scan spatial correlation potentially leading to incorrect diagnosis or treatment analysis. The retinal fovea is the location of the highest visual acuity and is present in all patients, thus it is critical to vision and highly suitable for use as a primary landmark for cross-vendor/cross-patient registration for precise comparison of disease states. However, the location of the fovea in diseased eyes is extremely challenging to locate due to varying appearance and the presence of retinal layer destroying pathology. Thus categorising and detecting the fovea type is an important prior stage to automatically computing the fovea position. Presented here is an automated cross-vendor method for fovea distinction in 3D SD-OCT scans of patients suffering from RVO, categorising scans into three distinct types. OCT scans are preprocessed by motion correction and noise filing followed by segmentation using a kernel graph-cut approach. A statistically derived mask is applied to the resulting scan creating an ROI around the probable fovea location from which the uppermost retinal surface is delineated. For a normal appearance retina, minimisation to zero thickness is computed using the top two retinal surfaces. 3D local minima detection and layer thickness analysis are used to differentiate between the remaining two fovea types. Validation employs ground truth fovea types identified by clinical experts at the Vienna Reading Center (VRC). The results presented here are intended to show the feasibility of this method for the accurate and reproducible distinction of retinal fovea types from multiple vendor 3D SD-OCT scans of patients suffering from RVO, and for use in fovea position detection systems as a landmark for intra- and cross-vendor 3D OCT registration.

Motor functioning, exploration, visuospatial cognition and language development in preschool children with autism.

PubMed

Hellendoorn, Annika; Wijnroks, Lex; van Daalen, Emma; Dietz, Claudine; Buitelaar, Jan K; Leseman, Paul

2015-04-01

In order to understand typical and atypical developmental trajectories it is important to assess how strengths or weaknesses in one domain may be affecting performance in other domains. This study examined longitudinal relations between early fine motor functioning, visuospatial cognition, exploration, and language development in preschool children with ASD and children with other developmental delays/disorders. The ASD group included 63 children at T1 (Mage = 27.10 months, SD = 8.71) and 46 children at T2 (Mage = 45.85 months, SD = 7.16). The DD group consisted of 269 children at T1 (Mage = 17.99 months, SD = 5.59), and 121 children at T2 (Mag e= 43.51 months, SD = 3.81). A subgroup nested within the total sample was randomly selected and studied in-depth on exploratory behavior. This group consisted of 50 children, 21 children with ASD (Mage = 27.57, SD = 7.09) and 29 children with DD (Mage = 24.03 months, SD = 6.42). Fine motor functioning predicted language in both groups. Fine motor functioning was related to visuospatial cognition in both groups and related to object exploration, spatial exploration, and social orientation during exploration only in the ASD group. Visuospatial cognition and all exploration measures were related to both receptive and expressive language in both groups. The findings are in line with the embodied cognition theory, which suggests that cognition emerges from and is grounded in the bodily interactions of an agent with the environment. This study emphasizes the need for researchers and clinicians to consider cognition as emergent from multiple interacting systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Students' perception of the learning environment and its relation to their study year and performance in Sudan.

PubMed

Ahmed, Yasar; Taha, Mohamed H; Al-Neel, Salma; Gaffar, Abdelrahim M

2018-05-24

To evaluate students' perceptions of the learning environment and to assess any differences in perception related to students' performance and their year of study. A descriptive cross-sectional study was performed of 638 students from the second, sixth and tenth semesters at the Faculty of Medicine at Gezira University, Sudan. This study employed the Arabic-translated Dundee Ready Education Environment Measure. The main predictor variables were the study year and academic performance. Descriptive statistics and one-way analysis of variance with a post hoc Tukey-Kramer multiple comparisons test were used for data analysis. The overall score for this study was 122/200 (SD=16.6), indicating a positive perception of the learning environment. The overall mean score was 109.94/200 (SD=21.2) for Semester 2 students, 122.9/200 (SD=20.29) for Semester 6 students, and 116.53 (SD=20.12) for Semester 10 students, reflecting a significant difference in students' perceptions in different years of study (F (2,2422) = 3.21, p=0.04). There was also a significant difference between the mean overall scores with respect to academic performance. High-achieving students' mean DREEM score was 126 (SD=24.4); while low-achieving students' mean DREEM score was 102 (SD=26.25) (F (2,2453) = 3.53, p=0.029). High achievers' perceptions of the learning environment are significantly better than those of low achievers. A significant difference was observed between students in different years of study. The differences in students' academic performance should be further investigated, targeting specific domains. A large-scale study is required to differentiate between the weakness and the strength of each academic level.

Hyperproteic hypocaloric enteral nutrition in the critically ill patient: A randomized controlled clinical trial

PubMed Central

Rugeles, Saúl-Javier; Rueda, Juan-David; Díaz, Carlos-Eduardo; Rosselli, Diego

2013-01-01

Introduction: Our aim was to evaluate the impact of hyperproteic hypocaloric enteral feeding on clinical outcomes in critically ill patients, particularly on severity of organic failure measured with the Sequential Organ Failure Assessment (SOFA). Materials and Methods: In a double blind clinical trial, 80 critically ill adult patients were randomized to hyperproteic hypocaloric or to isocaloric enteral nutrition; all patients completed follow-up of at least 4 days. Prescribed caloric intake was: Hyperproteic hypocaloric enteral nutrition (15 kcal/kg with 1.7 g/kg of protein) or isocaloric enteral nutrition (25 kcal/kg with 20% of the calories as protein). The main outcome was the differences in delta SOFA at 48 h. Secondary outcomes were intensive care unit (ICU) length of stay, days on ventilator, hyperglycemic events, and insulin requirements. Results: There were no differences in SOFA score at baseline (7.5 (standard deviation (SD) 2.9) vs 6.7 (SD 2.5) P = 0.17). The total amount of calories delivered was similarly low in both groups (12 kcal/kg in intervention group vs 14 kcal/kg in controls), but proteic delivery was significantly different (1.4 vs 0.76 g/kg, respectively P ≤ 0.0001). The intervention group showed an improvement in SOFA score at 48 h (delta SOFA 1.7 (SD 1.9) vs 0.7 (SD 2.8) P = 0.04) and less hyperglycemic episodes per day (1.0 (SD 1.3) vs 1.7 (SD 2.5) P = 0.017). Discussion: Enteral hyperproteic hypocaloric nutrition therapy could be associated with a decrease in multiple organ failure measured with SOFA score. We also found decreased hyperglycemia and a trend towards less mechanical ventilation days and ICU length of stay. PMID:24501485

Resolving the Origin of Pseudo-Single Domain Magnetic Behavior

NASA Astrophysics Data System (ADS)

Roberts, Andrew P.; Almeida, Trevor P.; Church, Nathan S.; Harrison, Richard J.; Heslop, David; Li, Yiliang; Li, Jinhua; Muxworthy, Adrian R.; Williams, Wyn; Zhao, Xiang

2017-12-01

The term "pseudo-single domain" (PSD) has been used to describe the transitional state in rock magnetism that spans the particle size range between the single domain (SD) and multidomain (MD) states. The particle size range for the stable SD state in the most commonly occurring terrestrial magnetic mineral, magnetite, is so narrow ( 20-75 nm) that it is widely considered that much of the paleomagnetic record of interest is carried by PSD rather than stable SD particles. The PSD concept has, thus, become the dominant explanation for the magnetization associated with a major fraction of particles that record paleomagnetic signals throughout geological time. In this paper, we argue that in contrast to the SD and MD states, the term PSD does not describe the relevant physical processes, which have been documented extensively using three-dimensional micromagnetic modeling and by parallel research in material science and solid-state physics. We also argue that features attributed to PSD behavior can be explained by nucleation of a single magnetic vortex immediately above the maximum stable SD transition size. With increasing particle size, multiple vortices, antivortices, and domain walls can nucleate, which produce variable cancellation of magnetic moments and a gradual transition into the MD state. Thus, while the term PSD describes a well-known transitional state, it fails to describe adequately the physics of the relevant processes. We recommend that use of this term should be discontinued in favor of "vortex state," which spans a range of behaviors associated with magnetic vortices.

Nanobody based immunoassay for human soluble epoxide hydrolase detection using polyHRP for signal enhancement—the rediscovery of polyHRP

USDA-ARS?s Scientific Manuscript database

Soluble epoxide hydrolase (sEH) is a potential pharmacological target for treating hypertension, vascular inflammation, cancer, pain and multiple cardiovascular related diseases. A variable domain of a heavy chain only antibody (termed sdAb, nanobody or VHH) possesses advantages of small size, high ...

Evaluating the Effect of Educational Media Exposure on Aggression in Early Childhood

ERIC Educational Resources Information Center

Ostrov, Jamie M.; Gentile, Douglas A.; Mullins, Adam D.

2013-01-01

Preschool-aged children (M = 42.44 months-old, SD = 8.02) participated in a short-term longitudinal study investigating the effect of educational media exposure on social development (i.e., aggression and prosocial behavior) using multiple informants and methods. As predicted, educational media exposure significantly predicted increases in both…

The Impact of Subsonic Twin Jets on Airport Noise

NASA Technical Reports Server (NTRS)

Bozak, Richard, F.

2012-01-01

Subsonic and supersonic aircraft concepts proposed through NASA s Fundamental Aeronautics Program have multiple engines mounted near one another. Engine configurations with multiple jets introduce an asymmetry to the azimuthal directivity of the jet noise. Current system noise predictions add the jet noise from each jet incoherently, therefore, twin jets are estimated by adding 3 EPNdB to the far-field noise radiated from a single jet. Twin jet effects have the ability to increase or decrease the radiated noise to different azimuthal observation locations. Experiments have shown that twin jet effects are reduced with forward flight and increasing spacings. The current experiment investigates the impact of spacing, and flight effects on airport noise for twin jets. Estimating the jet noise radiated from twin jets as that of a single jet plus 3 EPNdB may be sufficient for horizontal twin jets with an s/d of 4.4 and 5.5, where s is the center-to-center spacing and d is the jet diameter. However, up to a 3 EPNdB error could be present for jet spacings with an s/d of 2.6 and 3.2.

New Global Calculation of Nuclear Masses and Fission Barriers for Astrophysical Applications

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

Moeller, P.; Sierk, A. J.; Bengtsson, R.

The FRDM(1992) mass model [1] has an accuracy of 0.669 MeV in the region where its parameters were determined. For the 529 masses that have been measured since, its accuracy is 0.46 MeV, which is encouraging for applications far from stability in astrophysics. We are developing an improved mass model, the FRDM(2008). The improvements in the calculations with respect to the FRDM(1992) are in two main areas. (1) The macroscopic model parameters are better optimized. By simulation (adjusting to a limited set of now known nuclei) we can show that this actually makes the results more reliable in new regionsmore » of nuclei. (2) The ground-state deformation parameters are more accurately calculated. We minimize the energy in a four-dimensional deformation space ({epsilon}{sub 2}, {epsilon}{sub 3}, {epsilon}{sub 4}, {epsilon}{sub 6},) using a grid interval of 0.01 in all 4 deformation variables. The (non-finalized) FRDM (2008-a) has an accuracy of 0.596 MeV with respect to the 2003 Audi mass evaluation before triaxial shape degrees of freedom are included (in progress). When triaxiality effects are incorporated preliminary results indicate that the model accuracy will improve further, to about 0.586 MeV.We also discuss very large-scale fission-barrier calculations in the related FRLDM (2002) model, which has been shown to reproduce very satisfactorily known fission properties, for example barrier heights from {sup 70}Se to the heaviest elements, multiple fission modes in the Ra region, asymmetry of mass division in fission and the triple-humped structure found in light actinides. In the superheavy region we find barriers consistent with the observed half-lives. We have completed production calculations and obtain barrier heights for 5254 nuclei heavier than A = 170 for all nuclei between the proton and neutron drip lines. The energy is calculated for 5009325 different shapes for each nucleus and the optimum barrier between ground state and separated fragments is determined by use of an ''immersion'' technique.« less

An Innovative Open Data-driven Approach for Improved Interpretation of Coverage Data at NASA JPL's PO.DAA

NASA Astrophysics Data System (ADS)

McGibbney, L. J.; Armstrong, E. M.

2016-12-01

Figuratively speaking, Scientific Datasets (SD) are shared by data producers in a multitude of shapes, sizes and flavors. Primarily however they exist as machine-independent manifestations supporting the creation, access, and sharing of array-oriented SD that can on occasion be spread across multiple files. Within the Earth Sciences, the most notable general examples include the HDF family, NetCDF, etc. with other formats such as GRIB being used pervasively within specific domains such as the Oceanographic, Atmospheric and Meteorological sciences. Such file formats contain Coverage Data e.g. a digital representation of some spatio-temporal phenomenon. A challenge for large data producers such as NASA and NOAA as well as consumers of coverage datasets (particularly surrounding visualization and interactive use within web clients) is that this is still not a straight-forward issue due to size, serialization and inherent complexity. Additionally existing data formats are either unsuitable for the Web (like netCDF files) or hard to interpret independently due to missing standard structures and metadata (e.g. the OPeNDAP protocol). Therefore alternative, Web friendly manifestations of such datasets are required.CoverageJSON is an emerging data format for publishing coverage data to the web in a web-friendly, way which fits in with the linked data publication paradigm hence lowering the barrier for interpretation by consumers via mobile devices and client applications, etc. as well as data producers who can build next generation Web friendly Web services around datasets. This work will detail how CoverageJSON is being evaluated at NASA JPL's PO.DAAC as an enabling data representation format for publishing SD as Linked Open Data embedded within SD landing pages as well as via semantic data repositories. We are currently evaluating how utilization of CoverageJSON within SD landing pages addresses the long-standing acknowledgement that SD producers are not currently addressing content-based optimization within their SD landing pages for better crawlability by commercial search engines.

Mapping tissue inhomogeneity in acute myocarditis: a novel analytical approach to quantitative myocardial edema imaging by T2-mapping.

PubMed

Baeßler, Bettina; Schaarschmidt, Frank; Dick, Anastasia; Stehning, Christian; Schnackenburg, Bernhard; Michels, Guido; Maintz, David; Bunck, Alexander C

2015-12-23

The purpose of the present study was to investigate the diagnostic value of T2-mapping in acute myocarditis (ACM) and to define cut-off values for edema detection. Cardiovascular magnetic resonance (CMR) data of 31 patients with ACM were retrospectively analyzed. 30 healthy volunteers (HV) served as a control. Additionally to the routine CMR protocol, T2-mapping data were acquired at 1.5 T using a breathhold Gradient-Spin-Echo T2-mapping sequence in six short axis slices. T2-maps were segmented according to the 16-segments AHA-model and segmental T2 values as well as the segmental pixel-standard deviation (SD) were analyzed. Mean differences of global myocardial T2 or pixel-SD between HV and ACM patients were only small, lying in the normal range of HV. In contrast, variation of segmental T2 values and pixel-SD was much larger in ACM patients compared to HV. In random forests and multiple logistic regression analyses, the combination of the highest segmental T2 value within each patient (maxT2) and the mean absolute deviation (MAD) of log-transformed pixel-SD (madSD) over all 16 segments within each patient proved to be the best discriminators between HV and ACM patients with an AUC of 0.85 in ROC-analysis. In classification trees, a combined cut-off of 0.22 for madSD and of 68 ms for maxT2 resulted in 83% specificity and 81% sensitivity for detection of ACM. The proposed cut-off values for maxT2 and madSD in the setting of ACM allow edema detection with high sensitivity and specificity and therefore have the potential to overcome the hurdles of T2-mapping for its integration into clinical routine.

Communicable disease-related sudden death in the 21st century in Nigeria

PubMed Central

Akinwusi, Patience Olayinka; Komolafe, Akinwumi Oluwole; Olayemi, Olanrewaju Olayinka; Adeomi, Adeleye Abiodun

2013-01-01

Background Some cases of sudden death (SD) have been attributed to communicable diseases (CD) in middle- and low-income countries of the world even in this 21st century. CDs produce clinical symptoms and signs over several days before culminating in death. They are also amenable to treatment with antimicrobials if affected persons present early. We sought to find out the incidence of CD-related SD at the Ladoke Akintola University of Technology Teaching Hospital (Osogbo, Osun State, Nigeria) – a tertiary health facility in southwest Nigeria – and the prevailing associated factors. Methods We conducted a retrospective study of CD-related SD in adult patients aged 18 years and older that occurred from January 2003 to December 2011. The Statistical Package for the Social Sciences version 16 was used for analysis of the generated data. Percentages and frequencies were calculated. Results There were 17 (39.6%) CD-related SDs out of the 48 cases of SD studied. CD-related SD also accounted for 2.4% of all adult medical admissions. The mean age of the patients was 37.6 ± 11.6 years, age range of 25–62 years, mode of 25 years, and median 34 years. The male-to-female ratio was 1.8:1. Typhoid sepsis was responsible for SD in 47.1% of patients, pulmonary tuberculosis in 17.7% of patients, and lobar pneumonia in 17.7% of patients. The most affected age group was the 20–29-year-old group (41.2%), while the unskilled occupational group was the most affected occupational group with 35.3% of them having SD. Most of the patients with acute bacterial infection died of multiple organ failure. Conclusion There is an urgent need to step up public health strategies to curtail infections in this environment, encourage better use of the existing health facilities by the people, and the government should strive hard to make health a top priority. PMID:24124382

Photoperiod- and Triiodothyronine-dependent Regulation of Reproductive Neuropeptides, Proinflammatory Cytokines, and Peripheral Physiology in Siberian Hamsters (Phodopus sungorus).

PubMed

Banks, Ruth; Delibegovic, Mirela; Stevenson, Tyler J

2016-06-01

Seasonal trade-offs in reproduction and immunity are ubiquitous in nature. The mechanisms that govern transitions across seasonal physiological states appear to involve reciprocal switches in the local synthesis of thyroid hormone. In long-day (LD) summer-like conditions, increased hypothalamic triiodothyronine (T3) stimulates gonadal development. Alternatively, short-day (SD) winter-like conditions increase peripheral leukocytes and enhance multiple aspects of immune function. These data indicate that the localized effects of T3 in the hypothalamus and leukocytes are photoperiod dependent. We tested the hypothesis that increased peripheral T3 in SD conditions would increase aspects of reproductive physiology and inhibit immune function, whereas T3 injections in LD conditions would facilitate aspects of immune function (i.e., leukocytes). In addition, we also examined whether T3 regulates hypothalamic neuropeptide expression as well as hypothalamic and splenic proinflammatory cytokine expression. Adult male Siberian hamsters were maintained in LD (15L:9D) or transferred to SD (9L:15D) for 8 weeks. A subset of LD and SD hamsters was treated daily with 5 µg T3 for 2 weeks. LD and SD controls were injected with saline. Daily T3 administration in SD hamsters (SD+T3) resulted in a rapid and substantial decrease in peripheral leukocyte concentrations and stimulated gonadal development. T3 treatment in LD (LD+T3) had no effect on testicular volumes but significantly increased leukocyte concentrations. Molecular analyses revealed that T3 stimulated interleukin 1β messenger RNA (mRNA) expression in the spleen and inhibited RFamide Related Peptide-3 mRNA expression in the hypothalamus. Moreover, there was a photoperiod-dependent decrease in splenic tumor necrosis factor-α mRNA expression. These findings reveal that T3 has tissue-specific and photoperiod-dependent regulation of seasonal rhythms in reproduction and immune function. © 2016 The Author(s).

Association of anti-Mullerian hormone and small-dense low-density lipoprotein cholesterol with hepatosteatosis in young lean women with and without polycystic ovary syndrome.

PubMed

Oztas, Efser; Caglar, Gamze S; Kaya, Cemil; Karadag, Demet; Demirtas, Selda; Kurt, Mevlut; Pabuccu, Recai

2014-11-01

To study the association of anti-Mullerian hormone (AMH) and small-dense low-density lipoprotein cholesterol (sd-LDL) with hepatosteatosis among young, lean, polycystic ovary patients. A prospective, case control study was carried out including 79 young lean women. Fifty-eight women with polycystic ovary syndrome (PCOS) and 21 age-and BMI-matched healthy controls were recruited. Anthropometric variables, biochemical and hormonal parameters, insulin-resistance indices, lipid profiles including sd-LDL levels and serum AMH levels were determined. Hepatic lipid content was evaluated by abdominal ultrasonography (USG). Determining the best predictor(s) which discriminate normal USG and hepatosteatosis was analyzed by multiple logistic regression analyses. Adjusted odds ratios and 95% confidence intervals were also calculated. PCOS patients had an increased prevalence of hepatosteatosis by 41.4% (P = 0.006) and they had significantly higher levels of sd-LDL and AMH when compared with the control group (P < 0.001). AMH and sd-LDL levels were positively and significantly associated with hepatosteatosis in young lean women with and without PCOS (OR: 2.877, 95%CI: 1.453-5.699, P: 0.02 and OR: 1.336, 95%CI: 1.083-1.648, P: 0.007, respectively). AMH and sd-LDL levels were positively correlated in PCOS patients (r = 0.626, P < 0.001). Both sd-LDL and AMH levels were the most predictive parameters for the determination of hepatosteatosis within the PCOS group. (OR: 3.347, 95%CI: 1.348-8.313, P = 0.009 and OR: 1.375, 95%CI: 1.072-1.764, P = 0.012, respectively). Statistically significant higher levels of AMH were associated with hepatosteatosis both in insulin resistance (IR) positive and IR negative PCOS patients (P < 0.001). Hepatosteatosis is common in young lean PCOS patients. Increased AMH and sd-LDL levels may independently predict hepatosteatosis in young lean women with and without PCOS.

Somatization among persons with Turkish origin: Results of the pretest of the German National Cohort Study.

PubMed

Morawa, Eva; Dragano, Nico; Jöckel, Karl-Heinz; Moebus, Susanne; Brand, Tilman; Erim, Yesim

2017-05-01

Despite the emerging need to examine mental health of immigrants, there are no investigations designed to analyze representative samples in Germany. The aim of the present study was to explore the severity of somatic symptoms/somatization among a sample of considerable size consisting of persons with Turkish origin. We studied whether somatization was associated with sociodemographic and migration-related characteristics. This examination was part of a pretest for a large national epidemiological cohort study in Germany. We applied the somatization (PHQ-15) and the depression module (PHQ-9) from the Patient Health Questionnaire in a subsample of 335 Turkish immigrants. We analyzed the distribution of the sum score. Differences in degree of somatization in relation to relevant socio-demographic (gender) and migrant-related characteristics (generation of immigration) were tested with analysis of covariance (ANCOVA), controlling for age. A multiple linear regression analysis was also conducted. Women had significantly higher age-adjusted mean scores than men (M=10.4, SD=6.3 vs. M=8.1, SD=6.3; F=10.467, p=0.001), a significant effect of age was also found (F=4.853, p=0.028). First generation immigrants had a higher age-adjusted mean number of symptoms in relation to the second generation immigrants (M=10.0, SD=6.5 vs. M=7.4, SD=7.0; F=6.042, p=0.014), the effect of age was not significant (F=0.466, p=0.495). Multiple regression analysis revealed that lower severity of somatization was associated with lower numbers of diagnosed physical illnesses (β=0.271, p<0.001) and better language proficiency (β=0.197, p=0.003, explained variance: 15.6%). The degree of somatization among Turkish immigrants in Germany is associated with gender and generation of immigration. Copyright © 2017 Elsevier Inc. All rights reserved.

Decision-making in multiple sclerosis consultations in Italy: third observer and patient assessments.

PubMed

Pietrolongo, Erika; Giordano, Andrea; Kleinefeld, Monica; Confalonieri, Paolo; Lugaresi, Alessandra; Tortorella, Carla; Pugliatti, Maura; Radice, Davide; Goss, Claudia; Heesen, Christoph; Solari, Alessandra

2013-01-01

To assess decision-making in multiple sclerosis (MS) from third observer and patient perspectives. Audio recordings of first-ever consultations with a participating physician (88 outpatients, 10 physicians) at four tertiary MS care clinics in Italy, were rated by a third observer using the Observing Patient Involvement in Shared Decision Making (OPTION) and by patients using the Perceived Involvement in Care Scale (PICS). Mean patient age was 37.5, 66% were women, 72% had MS, and 28% had possible MS or other disease. Mean PICS subscale scores (range 0 poor, 100 best possible) were 71.9 (SD 24.3) for "physician facilitation" (PICS-F); 74.6 (SD 22.9) for "patient information exchange" (PICS-I); and only 22.5 (SD 16.2) for "patient decision making" (PICS-DM). Mean OPTION total score (0 poor, 100 best possible) was 29.6 (SD 10.3). Poorest OPTION scores were found for items assessing "preferred patient approach to receiving information" and "preferred patient level of involvement." Highest scores were for "clinician drawing attention to identified problem", "indicating need for decision making," and "need to review the decision." Consultation time, woman physician, patient-physician gender concordance and PICS-F were associated with higher OPTION total score; older physician and second opinion consultation were associated with lower OPTION score. In line with findings in other settings, our third observer findings indicated limited patient involvement abilities of MS physicians during first consultations. Patient perceptions of physician skills were better than third observers', although they correlated. Consultations with women physicians, and younger physicians, were associated with higher third observer and patient-based scores. Our findings reveal a need to empower Italian MS physicians with better communication and shared decision-making skills, and show in particular that attention to MS patient preferences for reception of information and involvement in health decisions, need to be improved.

A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive

NASA Astrophysics Data System (ADS)

Castillo, Richard; Castillo, Edward; Fuentes, David; Ahmad, Moiz; Wood, Abbie M.; Ludwig, Michelle S.; Guerrero, Thomas

2013-05-01

Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts.

What is the relationship between renal function and visit-to-visit blood pressure variability in primary care? Retrospective cohort study from routinely collected healthcare data.

PubMed

Lasserson, Daniel S; Scherpbier de Haan, Nynke; de Grauw, Wim; van der Wel, Mark; Wetzels, Jack F; O'Callaghan, Christopher A

2016-06-10

To determine the relationship between renal function and visit-to-visit blood pressure (BP) variability in a cohort of primary care patients. Retrospective cohort study from routinely collected healthcare data. Primary care in Nijmegen, the Netherlands, from 2007 to 2012. 19 175 patients who had a measure of renal function, and 7 separate visits with BP readings in the primary care record. Visit-to-visit variability in systolic BP, calculated from the first 7 office measurements, including SD, successive variation, absolute real variation and metrics of variability shown to be independent of mean. Multiple linear regression was used to analyse the influence of estimated glomerular filtration rate (eGFR) on BP variability measures with adjustment for age, sex, diabetes, mean BP, proteinuria, cardiovascular disease, time interval between measures and antihypertensive use. In the patient cohort, 57% were women, mean (SD) age was 65.5 (12.3) years, mean (SD) eGFR was 75.6 (18.0) mL/min/1.73m(2) and SD systolic BP 148.3 (21.4) mm Hg. All BP variability measures were negatively correlated with eGFR and positively correlated with age. However, multiple linear regressions demonstrated consistent, small magnitude negative relationships between eGFR and all measures of BP variability adjusting for confounding variables. Worsening renal function is associated with small increases in measures of visit-to-visit BP variability after adjustment for confounding factors. This is seen across the spectrum of renal function in the population, and provides a mechanism whereby chronic kidney disease may raise the risk of cardiovascular events. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Famous Landmark Identification in Amnestic Mild Cognitive Impairment and Alzheimer's Disease

PubMed Central

Sheardova, Katerina; Laczó, Jan; Vyhnalek, Martin; Andel, Ross; Mokrisova, Ivana; Vlcek, Kamil; Amlerova, Jana; Hort, Jakub

2014-01-01

Background Identification of famous landmarks (FLI), famous faces (FFI) and recognition of facial emotions (FER) is affected early in the course of Alzheimer's disease (AD). FFI, FER and FLI may represent domain specific tasks relying on activation of distinct regions of the medial temporal lobe, which are affected successively during the course of AD. However, the data on FFI and FER in MCI are controversial and FLI domain remains almost unexplored. Objectives To determine whether and how are these three specific domains impaired in head to head comparison of patients with amnestic MCI (aMCI) single domain (SD-aMCI) and multiple domain (MD-aMCI). We propose that FLI might be most reliable in differentiating SD-aMCI, which is considered to be an earlier stage of AD pathology spread out, from the controls. Patients and Methods A total of 114 patients, 13 with single domain (SD–aMCI) and 30 with multiple domains (MD–aMCI), 29 with mild AD and 42 controls underwent standard neurological and neuropsychological evaluations as well as tests of FLI, FER and FFI. Results Compared to the control group, AD subjects performed worse on FFI (p = 0.020), FER (p<0.001) and FLI (p<0.001), MD-aMCI group had significantly worse scores only on FLI (p = 0.002) and approached statistical significance on FER (0.053). SD-aMCI group performed significantly worse only on FLI (p = 0.028) compared to controls. Conclusions Patients with SD-aMCI had an isolated impairment restricted to FLI, while patients with MD–aMCI showed impairment in FLI as well as in FER. Patients with mild dementia due to AD have more extensive impairment of higher visual perception. The results suggest that FLI testing may contribute to identification of patients at risk of AD. We hypothesize that clinical examination of all three domains might reflect the spread of the disease from transentorhinal cortex, over amygdala to fusiform gyrus. PMID:25144755

Comparative evaluation of subgrade resilient modulus from non-destructive, in-situ, and laboratory methods : technical summary report.

DOT National Transportation Integrated Search

2008-09-01

The Resilient Modulus (Mr) of pavement materials and subgrades is an important input : parameter for the design of pavement structures. The Repeated Loading Triaxial (RLT) test : typically determines Mr. However, the RLT test requires well trained pe...

Post-cyclic behavior of low plasticity silt under full and limited liquefaction using triaxial compression testing.

DOT National Transportation Integrated Search

2010-02-01

During an earthquake, liquefaction does not happen all the time. It depends on the duration and magnitude of the earthquake and the properties (with relationship to resistance of liquefaction) of the low plasticity silt. Under low duration or magnitu...

Navy-Wide Personnel Survey (NPS) 1992: Graphic Presentation of Results for Officers

DTIC Science & Technology

1993-08-01

DEPENDENTS? (TOTAL-OFFICERS) LIVING WITH4 NOT LIVING WITHm LEGAL WARDS WTH DEPENDENT PARENTS J 0 10 2D 30 40 so 60 70 s0 90 100 Percent NPS-92 MULTIPLE...RESPONSE QUESTION S 07 DEPENDENTS (IF HAVE MILITARY SPOUSE) BY 020 PAY GRADE (OFFICERS) LIVING : NOT LIVING E LEGAL WARDS WMT-" [Zýcwo DEPENDENT PARENTS ...SPOUSE CHILDREN WITH • CHILDREN NOT WITH LEGAL WARDS WITH PARENTS W 0 10 20 30 40 o SD o 70 o 0 1,00 Percent NPS-92 MULTIPLE RESPONSE QUESTION 08 DO

Global phylogeography and evolutionary history of Shigella dysenteriae type 1.

PubMed

Njamkepo, Elisabeth; Fawal, Nizar; Tran-Dien, Alicia; Hawkey, Jane; Strockbine, Nancy; Jenkins, Claire; Talukder, Kaisar A; Bercion, Raymond; Kuleshov, Konstantin; Kolínská, Renáta; Russell, Julie E; Kaftyreva, Lidia; Accou-Demartin, Marie; Karas, Andreas; Vandenberg, Olivier; Mather, Alison E; Mason, Carl J; Page, Andrew J; Ramamurthy, Thandavarayan; Bizet, Chantal; Gamian, Andrzej; Carle, Isabelle; Sow, Amy Gassama; Bouchier, Christiane; Wester, Astrid Louise; Lejay-Collin, Monique; Fonkoua, Marie-Christine; Le Hello, Simon; Blaser, Martin J; Jernberg, Cecilia; Ruckly, Corinne; Mérens, Audrey; Page, Anne-Laure; Aslett, Martin; Roggentin, Peter; Fruth, Angelika; Denamur, Erick; Venkatesan, Malabi; Bercovier, Hervé; Bodhidatta, Ladaporn; Chiou, Chien-Shun; Clermont, Dominique; Colonna, Bianca; Egorova, Svetlana; Pazhani, Gururaja P; Ezernitchi, Analia V; Guigon, Ghislaine; Harris, Simon R; Izumiya, Hidemasa; Korzeniowska-Kowal, Agnieszka; Lutyńska, Anna; Gouali, Malika; Grimont, Francine; Langendorf, Céline; Marejková, Monika; Peterson, Lorea A M; Perez-Perez, Guillermo; Ngandjio, Antoinette; Podkolzin, Alexander; Souche, Erika; Makarova, Mariia; Shipulin, German A; Ye, Changyun; Žemličková, Helena; Herpay, Mária; Grimont, Patrick A D; Parkhill, Julian; Sansonetti, Philippe; Holt, Kathryn E; Brisse, Sylvain; Thomson, Nicholas R; Weill, François-Xavier

2016-03-21

Together with plague, smallpox and typhus, epidemics of dysentery have been a major scourge of human populations for centuries(1). A previous genomic study concluded that Shigella dysenteriae type 1 (Sd1), the epidemic dysentery bacillus, emerged and spread worldwide after the First World War, with no clear pattern of transmission(2). This is not consistent with the massive cyclic dysentery epidemics reported in Europe during the eighteenth and nineteenth centuries(1,3,4) and the first isolation of Sd1 in Japan in 1897(5). Here, we report a whole-genome analysis of 331 Sd1 isolates from around the world, collected between 1915 and 2011, providing us with unprecedented insight into the historical spread of this pathogen. We show here that Sd1 has existed since at least the eighteenth century and that it swept the globe at the end of the nineteenth century, diversifying into distinct lineages associated with the First World War, Second World War and various conflicts or natural disasters across Africa, Asia and Central America. We also provide a unique historical perspective on the evolution of antibiotic resistance over a 100-year period, beginning decades before the antibiotic era, and identify a prevalent multiple antibiotic-resistant lineage in South Asia that was transmitted in several waves to Africa, where it caused severe outbreaks of disease.

A target-unrelated peptide in an M13 phage display library traced to an advantageous mutation in the gene II ribosome-binding site.

PubMed

Brammer, Leighanne A; Bolduc, Benjamin; Kass, Jessica L; Felice, Kristin M; Noren, Christopher J; Hall, Marilena Fitzsimons

2008-02-01

Screening of the commercially available Ph.D.-7 phage-displayed heptapeptide library for peptides that bind immobilized Zn2+ resulted in the repeated selection of the peptide HAIYPRH, although binding assays indicated that HAIYPRH is not a zinc-binding peptide. HAIYPRH has also been selected in several other laboratories using completely different targets, and its ubiquity suggests that it is a target-unrelated peptide. We demonstrated that phage displaying HAIYPRH are enriched after serial amplification of the library without exposure to target. The amplification of phage displaying HAIYPRH was found to be dramatically faster than that of the library itself. DNA sequencing uncovered a mutation in the Shine-Dalgarno (SD) sequence for gIIp, a protein involved in phage replication, imparting to the SD sequence better complementarity to the 16S ribosomal RNA (rRNA). Introducing this mutation into phage lacking a displayed peptide resulted in accelerated propagation, whereas phage displaying HAIYPRH with a wild-type SD sequence were found to amplify normally. The SD mutation may alter gIIp expression and, consequently, the rate of propagation of phage. In the Ph.D.-7 library, the mutation is coincident with the displayed peptide HAIYPRH, accounting for the target-unrelated selection of this peptide in multiple reported panning experiments.

Rett syndrome: basic features of visual processing-a pilot study of eye-tracking.

PubMed

Djukic, Aleksandra; Valicenti McDermott, Maria; Mavrommatis, Kathleen; Martins, Cristina L

2012-07-01

Consistently observed "strong eye gaze" has not been validated as a means of communication in girls with Rett syndrome, ubiquitously affected by apraxia, unable to reply either verbally or manually to questions during formal psychologic assessment. We examined nonverbal cognitive abilities and basic features of visual processing (visual discrimination attention/memory) by analyzing patterns of visual fixation in 44 girls with Rett syndrome, compared with typical control subjects. To determine features of visual fixation patterns, multiple pictures (with the location of the salient and presence/absence of novel stimuli as variables) were presented on the screen of a TS120 eye-tracker. Of the 44, 35 (80%) calibrated and exhibited meaningful patterns of visual fixation. They looked longer at salient stimuli (cartoon, 2.8 ± 2 seconds S.D., vs shape, 0.9 ± 1.2 seconds S.D.; P = 0.02), regardless of their position on the screen. They recognized novel stimuli, decreasing the fixation time on the central image when another image appeared on the periphery of the slide (2.7 ± 1 seconds S.D. vs 1.8 ± 1 seconds S.D., P = 0.002). Eye-tracking provides a feasible method for cognitive assessment and new insights into the "hidden" abilities of individuals with Rett syndrome. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of the Health Tourism weight loss programme on body composition and health outcomes in healthy and excess-weight adults.

PubMed

Sagayama, Hiroyuki; Shizuma, Kayoko; Toguchi, Makiko; Mizuhara, Hiroji; Machida, Yukiko; Yamada, Yosuke; Ebine, Naoyuki; Higaki, Yasuki; Tanaka, Hiroaki

2018-05-01

Excess weight loss while minimising fat-free mass (FFM) loss is important for health. Travel is a particular period at risk for weight gain and for which the effects of a short-term intensive weight loss programme have not been studied. Therefore, we studied the effect of a novel, 1-week supervised health travel programme combining high volume, low-to-moderate intensity exercise and energy intake restriction on weight, body composition and health outcomes in adults. Weight was also monitored for 12 weeks after the programme. In all, thirty-six subjects (nineteen men, seventeen women) consisting of sixteen excess-weight (BMI: 27·1 (sd 1·7) kg/m2) and twenty healthy-weight (BMI: 22·3 (sd 1·8) kg/m2) individuals participated. Subjects performed 1 h of slow-paced intermittent jogging three times per d and other leisure activities, whereas consuming only provided foods without water restriction. Body mass significantly decreased from pre- to post-intervention in excess-weight and healthy-weight individuals (-3·5 (sd 1·5) and -3·5 (sd 1·3) %, respectively; P<0·001 for both), and losses were maintained at 12 weeks post-intervention in both groups (-6·3 (sd 3·8) and -1·7 (sd 4·0) %, respectively; P<0·01 for both). Fat mass also significantly decreased in both groups (excess weight: -9·2 (sd 4·6) %: healthy weight: -13·4 (sd 9·0) %; P<0·01 for both), whereas FFM was maintained. Similar improvements were observed for blood biochemistry and pressure in both groups. This short-term weight loss intervention yielded favourable outcomes in both excess- and healthy-weight adults, particularly a 3·5 % weight loss with no significant change to FFM. In addition, participants maintained weight loss for at least 12 weeks. Of multiple programme choices, the Health Tourism weight loss programme's results indicate that it is a viable option.

The role of laryngoscopy in the diagnosis of spasmodic dysphonia.

PubMed

Daraei, Pedram; Villari, Craig R; Rubin, Adam D; Hillel, Alexander T; Hapner, Edie R; Klein, Adam M; Johns, Michael M

2014-03-01

Spasmodic dysphonia (SD) can be difficult to diagnose, and patients often see multiple physicians for many years before diagnosis. Improving the speed of diagnosis for individuals with SD may decrease the time to treatment and improve patient quality of life more quickly. To assess whether the diagnosis of SD can be accurately predicted through auditory cues alone without the assistance of visual cues offered by laryngoscopic examination. Single-masked, case-control study at a specialized referral center that included patients who underwent laryngoscopic examination as part of a multidisciplinary workup for dysphonia. Twenty-two patients were selected in total: 10 with SD, 5 with vocal tremor, and 7 controls without SD or vocal tremor. The laryngoscopic examination was recorded, deidentified, and edited to make 3 media clips for each patient: video alone, audio alone, and combined video and audio. These clips were randomized and presented to 3 fellowship-trained laryngologist raters (A.D.R., A.T.H., and A.M.K.), who established the most probable diagnosis for each clip. Intrarater and interrater reliability were evaluated using repeat clips incorporated in the presentations. We measured diagnostic accuracy for video-only, audio-only, and combined multimedia clips. These measures were established before data collection. Data analysis was accomplished with analysis of variance and Tukey honestly significant differences. Of patients with SD, diagnostic accuracy was 10%, 73%, and 73% for video-only, audio-only, and combined, respectively (P < .001, df = 2). Of patients with vocal tremor, diagnostic accuracy was 93%, 73%, and 100% for video-only, audio-only, and combined, respectively (P = .05, df = 2). Of the controls, diagnostic accuracy was 81%, 19%, and 62% for video-only, audio-only, and combined, respectively (P < .001, df = 2). The diagnosis of SD during examination is based primarily on auditory cues. Viewing combined audio and video clips afforded no change in diagnostic accuracy compared with audio alone. Laryngoscopy serves an important role in the diagnosis of SD by excluding other pathologic causes and identifying vocal tremor.

What is the best way to contour lung tumors on PET scans? Multiobserver validation of a gradient-based method using a NSCLC digital PET phantom.

PubMed

Werner-Wasik, Maria; Nelson, Arden D; Choi, Walter; Arai, Yoshio; Faulhaber, Peter F; Kang, Patrick; Almeida, Fabio D; Xiao, Ying; Ohri, Nitin; Brockway, Kristin D; Piper, Jonathan W; Nelson, Aaron S

2012-03-01

To evaluate the accuracy and consistency of a gradient-based positron emission tomography (PET) segmentation method, GRADIENT, compared with manual (MANUAL) and constant threshold (THRESHOLD) methods. Contouring accuracy was evaluated with sphere phantoms and clinically realistic Monte Carlo PET phantoms of the thorax. The sphere phantoms were 10-37 mm in diameter and were acquired at five institutions emulating clinical conditions. One institution also acquired a sphere phantom with multiple source-to-background ratios of 2:1, 5:1, 10:1, 20:1, and 70:1. One observer segmented (contoured) each sphere with GRADIENT and THRESHOLD from 25% to 50% at 5% increments. Subsequently, seven physicians segmented 31 lesions (7-264 mL) from 25 digital thorax phantoms using GRADIENT, THRESHOLD, and MANUAL. For spheres <20 mm in diameter, GRADIENT was the most accurate with a mean absolute % error in diameter of 8.15% (10.2% SD) compared with 49.2% (51.1% SD) for 45% THRESHOLD (p < 0.005). For larger spheres, the methods were statistically equivalent. For varying source-to-background ratios, GRADIENT was the most accurate for spheres >20 mm (p < 0.065) and <20 mm (p < 0.015). For digital thorax phantoms, GRADIENT was the most accurate (p < 0.01), with a mean absolute % error in volume of 10.99% (11.9% SD), followed by 25% THRESHOLD at 17.5% (29.4% SD), and MANUAL at 19.5% (17.2% SD). GRADIENT had the least systematic bias, with a mean % error in volume of -0.05% (16.2% SD) compared with 25% THRESHOLD at -2.1% (34.2% SD) and MANUAL at -16.3% (20.2% SD; p value <0.01). Interobserver variability was reduced using GRADIENT compared with both 25% THRESHOLD and MANUAL (p value <0.01, Levene's test). GRADIENT was the most accurate and consistent technique for target volume contouring. GRADIENT was also the most robust for varying imaging conditions. GRADIENT has the potential to play an important role for tumor delineation in radiation therapy planning and response assessment. Copyright © 2012. Published by Elsevier Inc.

Trading shallow safety for deep sleep: Juvenile green turtles select deeper resting sites as they grow

USGS Publications Warehouse

Hart, Kristen M.; White, Connor F.; Iverson, Autumn R.; Whitney, Nick

2016-01-01

To better protect endangered green sea turtles Chelonia mydas, a more thorough understanding of the behaviors of each life stage is needed. Although dive profile analyses obtained using time-depth loggers have provided some insights into habitat use, recent work has shown that more fine-scale monitoring of body movements is needed to elucidate physical activity patterns. We monitored 11 juvenile green sea turtles with tri-axial acceleration data loggers in their foraging grounds in Dry Tortugas National Park, Florida, USA, for periods ranging from 43 to 118 h (mean ± SD: 72.8 ± 27.3 h). Approximately half of the individuals (n = 5) remained in shallow (overall mean depth less than 2 m) water throughout the experiment, whereas the remaining individuals (n = 6) made excursions to deeper (4 to 27 m) waters, often at night. Despite these differences in depth use, acceleration data revealed a consistent pattern of diurnal activity and nocturnal resting in most individuals. Nocturnal depth differences thus do not appear to represent differences in behavior, but rather different strategies to achieve the same behavior: rest. We calculated overall dynamic body acceleration (ODBA) to assess the relative energetic cost of each behavioral strategy in an attempt to explain the differences between them. Animals in deeper water experienced longer resting dives, more time resting per hour, and lower mean hourly ODBA. These results suggest that resting in deeper water provides energetic benefits that outweigh the costs of transiting to deep water and a potential increased risk of predation.

Calibration of micromechanical parameters for DEM simulations by using the particle filter

NASA Astrophysics Data System (ADS)

Cheng, Hongyang; Shuku, Takayuki; Thoeni, Klaus; Yamamoto, Haruyuki

2017-06-01

The calibration of DEM models is typically accomplished by trail and error. However, the procedure lacks of objectivity and has several uncertainties. To deal with these issues, the particle filter is employed as a novel approach to calibrate DEM models of granular soils. The posterior probability distribution of the microparameters that give numerical results in good agreement with the experimental response of a Toyoura sand specimen is approximated by independent model trajectories, referred as `particles', based on Monte Carlo sampling. The soil specimen is modeled by polydisperse packings with different numbers of spherical grains. Prepared in `stress-free' states, the packings are subjected to triaxial quasistatic loading. Given the experimental data, the posterior probability distribution is incrementally updated, until convergence is reached. The resulting `particles' with higher weights are identified as the calibration results. The evolutions of the weighted averages and posterior probability distribution of the micro-parameters are plotted to show the advantage of using a particle filter, i.e., multiple solutions are identified for each parameter with known probabilities of reproducing the experimental response.

Microscopic analysis of shape transition in neutron-deficient Yb isotopes

NASA Astrophysics Data System (ADS)

Fu, Y.; Tong, H.; Wang, X. F.; Wang, H.; Wang, D. Q.; Wang, X. Y.; Yao, J. M.

2018-01-01

The development of nuclear collectivity in even-even Yb-170152 is studied with three types of mean-field calculations: the nonrelativistic Hartree-Fock plus BCS calculation using the Skyrme SLy4 force plus a density-dependent δ pairing force and the relativistic mean-field calculation using a point-coupling energy functional supplemented with either a density-independent δ pairing force or a separable pairing force. The low-lying states are obtained by solving a five-dimensional collective Hamiltonian with parameters determined from the three mean-field solutions. The energy surfaces, excitation energies, electric multiple transition strengths, and differential isotope shifts are presented in comparison with available data. Our results show that different treatments of pairing correlations have a significant influence on the speed of developing collectivity as the increase of neutron number. All the calculations demonstrate the important role of dynamic shape-mixing effects in resolving the puzzle in the dramatic increase of charge radius from 152Yb to 154Yb and the role of triaxiality in Yb 160 ,162 ,164 .

Space Acceleration Measurement System-II: Microgravity Instrumentation for the International Space Station Research Community

NASA Technical Reports Server (NTRS)

Sutliff, Thomas J.

1999-01-01

The International Space Station opens for business in the year 2000, and with the opening, science investigations will take advantage of the unique conditions it provides as an on-orbit laboratory for research. With initiation of scientific studies comes a need to understand the environment present during research. The Space Acceleration Measurement System-II provides researchers a consistent means to understand the vibratory conditions present during experimentation on the International Space Station. The Space Acceleration Measurement System-II, or SAMS-II, detects vibrations present while the space station is operating. SAMS-II on-orbit hardware is comprised of two basic building block elements: a centralized control unit and multiple Remote Triaxial Sensors deployed to measure the acceleration environment at the point of scientific research, generally within a research rack. Ground Operations Equipment is deployed to complete the command, control and data telemetry elements of the SAMS-II implementation. Initially, operations consist of user requirements development, measurement sensor deployment and use, and data recovery on the ground. Future system enhancements will provide additional user functionality and support more simultaneous users.

Understanding Hydraulic Fracturing: A Multi-Scale Problem

DOE PAGES

Hyman, Jeffrey De'Haven; Gimenez Martinez, Joaquin; Viswanathan, Hari S.; ...

2016-09-05

Despite the impact that hydraulic fracturing has had on the energy sector, the physical mechanisms that control its efficiency and environmental impacts remain poorly understood in part because the length scales involved range from nano-meters to kilo-meters. We characterize flow and transport in shale formations across and between these scales using integrated computational, theoretical, and experimental efforts. At the field scale, we use discrete fracture network modeling to simulate production at a well site whose fracture network is based on a site characterization of a shale formation. At the core scale, we use triaxial fracture experiments and a finite-element discrete-elementmore » fracture propagation model with a coupled fluid solver to study dynamic crack propagation in low permeability shale. We use lattice Boltzmann pore-scale simulations and microfluidic experiments in both synthetic and real micromodels to study pore-scale flow phenomenon such as multiphase flow and mixing. A mechanistic description and integration of these multiple scales is required for accurate predictions of production and the eventual optimization of hydrocarbon extraction from unconventional reservoirs.« less

Measurement of Exercise Intensity with a Tri-Axial Accelerometer during Military Training

DTIC Science & Technology

2009-10-01

PO Box 90.004 3509 AA Utrecht The Netherlands ABSTRACT Exercise load and intensity, as reflected in energy expenditure, are determinants of...18. Total body water was estimated from calculated body composition, based on height, weight, age and gender , with the equation of Deurenberg et

Ride Motion Simulator Safety Assessment Report

DTIC Science & Technology

2013-07-01

it does with an ESTOP shutdown. 5.4.3.1.3.1 SeTAC ISO-2631 Monitoring Device The Sequoia Tri-axial Accelerometer Computer (SeTAC) ISO-2631...independent systems which continuously supervise accelerations of the platform when the simulator is in the human-rated mode. Figure 5- 6 Sequoia Tri

Energy Coupling During the August 2011 Magnetic Storm (Postprint)

DTIC Science & Technology

2014-08-27

of the horizontal cross-track plasma drifts in this study. SSM sensors are triaxial fluxgate magnetometers that are mounted on 0.5m booms on the F15...Special Sensor for Ions Electrons and Scintillations (SSIES)). All of the satellites carry magnetometers (Special Sensor for Magnetic Fields (SSM)) to

Multiscale characterization and mechanical modeling of an Al-Zn-Mg electron beam weld

NASA Astrophysics Data System (ADS)

Puydt, Quentin; Flouriot, Sylvain; Ringeval, Sylvain; Parry, Guillaume; De Geuser, Frédéric; Deschamps, Alexis

Welding of precipitation hardening alloys results in multi-scale microstructural heterogeneities, from the hardening nano-scale precipitates to the micron-scale solidification structures and to the component geometry. This heterogeneity results in a complex mechanical response, with gradients in strength, stress triaxiality and damage initiation sites.

Relationship between lung function and quantitative computed tomographic parameters of airway remodeling, air trapping, and emphysema in patients with asthma and chronic obstructive pulmonary disease: A single-center study.

PubMed

Hartley, Ruth A; Barker, Bethan L; Newby, Chris; Pakkal, Mini; Baldi, Simonetta; Kajekar, Radhika; Kay, Richard; Laurencin, Marie; Marshall, Richard P; Sousa, Ana R; Parmar, Harsukh; Siddiqui, Salman; Gupta, Sumit; Brightling, Chris E

2016-05-01

There is a paucity of studies comparing asthma and chronic obstructive pulmonary disease (COPD) based on thoracic quantitative computed tomographic (QCT) parameters. We sought to compare QCT parameters of airway remodeling, air trapping, and emphysema between asthmatic patients and patients with COPD and explore their relationship with airflow limitation. Asthmatic patients (n = 171), patients with COPD (n = 81), and healthy subjects (n = 49) recruited from a single center underwent QCT and clinical characterization. Proximal airway percentage wall area (%WA) was significantly increased in asthmatic patients (62.5% [SD, 2.2]) and patients with COPD (62.7% [SD, 2.3]) compared with that in healthy control subjects (60.3% [SD, 2.2], P < .001). Air trapping measured based on mean lung density expiratory/inspiratory ratio was significantly increased in patients with COPD (mean, 0.922 [SD, 0.037]) and asthmatic patients (mean, 0.852 [SD, 0.061]) compared with that in healthy subjects (mean, 0.816 [SD, 0.066], P < .001). Emphysema assessed based on lung density measured by using Hounsfield units below which 15% of the voxels lie (Perc15) was a feature of COPD only (patients with COPD: mean, -964 [SD, 19.62] vs asthmatic patients: mean, -937 [SD, 22.7] and healthy subjects: mean, -937 [SD, 17.1], P < .001). Multiple regression analyses showed that the strongest predictor of lung function impairment in asthmatic patients was %WA, whereas in the COPD and asthma subgrouped with postbronchodilator FEV1 percent predicted value of less than 80%, it was air trapping. Factor analysis of QCT parameters in asthmatic patients and patients with COPD combined determined 3 components, with %WA, air trapping, and Perc15 values being the highest loading factors. Cluster analysis identified 3 clusters with mild, moderate, or severe lung function impairment with corresponding decreased lung density (Perc15 values) and increased air trapping. In asthmatic patients and patients with COPD, lung function impairment is strongly associated with air trapping, with a contribution from proximal airway narrowing in asthmatic patients. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Associations between self-rated health and personality.

PubMed

Aiken-Morgan, Adrienne T; Bichsel, Jacqueline; Savla, Jyoti; Edwards, Christopher L; Whitfield, Keith E

2014-01-01

The goal of our study was to examine how Big Five personality factors predict variability in self-rated health in a sample of older African Americans from the Baltimore Study of Black Aging. Personality was measured by the NEO Personality Inventory-Revised, and self-rated health was assessed by the Health Problems Checklist. The study sample had 202 women and 87 men. Ages ranged from 49 to 90 years (M = 67.2 years, SD = 8.55), and average years of formal education was 10.8 (SD = 3.3). Multiple linear regressions showed that neuroticism and extraversion were significant regression predictors of self-rated health, after controlling for demographic factors. These findings suggest individual personality traits may influence health ratings, behaviors, and decision-making among older African Americans.

Adherence to subcutaneous interferon beta-1a treatment using an electronic injection device: a prospective open-label Scandinavian noninterventional study (the ScanSmart study)

PubMed Central

Pedersen, Elena Didenko; Stenager, Egon; Vadgaard, JL; Jensen, MB; Schmid, R; Meland, N; Magnussen, G; Frederiksen, Jette L

2018-01-01

Background Disease modifying drugs help control the course of relapsing remitting multiple sclerosis (RRMS); however, good adherence is needed for long-term outcomes. Objective To evaluate patient adherence to treatment with subcutaneous interferon beta-1a using RebiSmart® and assess injection-site reactions and treatment satisfaction. Methods This prospective, single-arm, open-label, noninterventional multicenter Phase IV trial included disease modifying drug-experienced mobile patients with RRMS. Adherence was measured over 12 weeks. Items 13–23, 35, 37, and 38 of the Multiple Sclerosis Treatment Concerns Questionnaire (injection-site reactions and treatment satisfaction) were recorded at 12 weeks. Results Sixty patients were recruited (mean age 43.7 [±SD 7.9] years; 83% female; mean years since multiple sclerosis diagnosis 6.7 [SD 4.5]). Adherence data were obtained in 54 patients only due to technical problems with six devices. Over 12 weeks, 89% (n=48) of patients had ≥90% adherence to treatment. Most patients experienced mild influenza-like symptoms and injection-site reactions, and global side effects were minimal. Most patients (78%) rated the convenience as the most important aspect of the device, and most experienced no or mild pain. Conclusion RRMS patients treated with subcutaneous interferon beta-1a, administered with RebiSmart, demonstrated generally good adherence, and the treatment was generally well tolerated. PMID:29720872

Adherence to subcutaneous interferon beta-1a treatment using an electronic injection device: a prospective open-label Scandinavian noninterventional study (the ScanSmart study).

PubMed

Pedersen, Elena Didenko; Stenager, Egon; Vadgaard, J L; Jensen, M B; Schmid, R; Meland, N; Magnussen, G; Frederiksen, Jette L

2018-01-01

Disease modifying drugs help control the course of relapsing remitting multiple sclerosis (RRMS); however, good adherence is needed for long-term outcomes. To evaluate patient adherence to treatment with subcutaneous interferon beta-1a using RebiSmart ® and assess injection-site reactions and treatment satisfaction. This prospective, single-arm, open-label, noninterventional multicenter Phase IV trial included disease modifying drug-experienced mobile patients with RRMS. Adherence was measured over 12 weeks. Items 13-23, 35, 37, and 38 of the Multiple Sclerosis Treatment Concerns Questionnaire (injection-site reactions and treatment satisfaction) were recorded at 12 weeks. Sixty patients were recruited (mean age 43.7 [±SD 7.9] years; 83% female; mean years since multiple sclerosis diagnosis 6.7 [SD 4.5]). Adherence data were obtained in 54 patients only due to technical problems with six devices. Over 12 weeks, 89% (n=48) of patients had ≥90% adherence to treatment. Most patients experienced mild influenza-like symptoms and injection-site reactions, and global side effects were minimal. Most patients (78%) rated the convenience as the most important aspect of the device, and most experienced no or mild pain. RRMS patients treated with subcutaneous interferon beta-1a, administered with RebiSmart, demonstrated generally good adherence, and the treatment was generally well tolerated.

Latino Adolescents' Perceived Discrimination in Online and Offline Settings: An Examination of Cultural Risk and Protective Factors

ERIC Educational Resources Information Center

Umaña-Taylor, Adriana J.; Tynes, Brendesha M.; Toomey, Russell B.; Williams, David R.; Mitchell, Kimberly J.

2015-01-01

Guided by a risk and resilience framework, the current study examined the associations between Latino adolescents' ("n" = 219; "M" [subscript age] = 14.35; "SD" = 1.75) perceptions of ethnic discrimination in multiple settings (e.g., online, school) and several domains of adjustment (e.g., mental health, academic),…

Effects of Quizzing Methodology on Student Outcomes: Reading Compliance, Retention, and Perceptions

ERIC Educational Resources Information Center

Dowling, Carey Bernini

2017-01-01

This study set out to replicate and extend research on students' reading compliance and examine the impact of daily quizzing methodology on students' reading compliance and retention. 98 students in two sections of Abnormal Psychology participated (mean age = 21.5, SD = 3.35; 72.4% Caucasian). Using a multiple baseline quasi-experimental design…

The effect of a movement-to-music video program on the objectively measured sedentary time and physical activity of preschool-aged children and their mothers: A randomized controlled trial.

PubMed

Tuominen, Pipsa P A; Husu, Pauliina; Raitanen, Jani; Kujala, Urho M; Luoto, Riitta M

2017-01-01

Regular physical activity (PA) and the avoidance of prolonged sitting are essential for children's healthy growth, and for the physical and mental wellbeing of both children and adults. In the context of exercise, music may promote behavioral change through increased exercise adherence and participation. The purpose of this study was to determine whether a movement-to-music video program could reduce sedentary behavior (SB) and increase PA in mother-child pairs in the home environment. A randomized controlled trial was conducted in the Pirkanmaa region, Finland, in 2014-2016. The participants consisted of 228 mother-child pairs (child age 5-7 years). The primary outcomes of interest were tri-axial accelerometer-derived SB and PA, which were measured in weeks one (baseline), two, and eight in both the intervention and control groups. Further, the mothers and children in the intervention group used a movement-to-music video program from the beginning of week two to the end of week eight. Secondary outcomes included self-reported screen time. The statistical methods employed comprised an intention-to-treat and linear mixed effects model design. No statistically significant differences between groups were found in primary or secondary outcomes. Among the children in the control group, light PA decreased significantly over time and screen time increased from 89 (standard deviation, SD 37) to 99 (SD 41) min/d. Among mothers and children in the intervention group, no statistical differences were found. In supplementary analysis, the children who stayed at home instead of attending daycare/preschool had on average 25 (95% confidence interval, CI 19-30) min/d more sedentary time and 11 (95% CI 8-14) min/d less moderate-to-vigorous PA than those who were at daycare/preschool. The higher body mass index of mothers was related with 5 (95% CI 2-7) min/d more sedentary time and 1 (95% CI 0-2) min/d less moderate-to-vigorous PA. The movement-to-music video program did not change the objectively measured SB or PA of the mother-child pairs. However, mothers and children seemed to be more sedentary at home, and therefore interventions for decreasing SB and increasing PA should be targeted in the home environment.

The effect of a movement-to-music video program on the objectively measured sedentary time and physical activity of preschool-aged children and their mothers: A randomized controlled trial

PubMed Central

Husu, Pauliina; Raitanen, Jani; Kujala, Urho M.; Luoto, Riitta M.

2017-01-01

Regular physical activity (PA) and the avoidance of prolonged sitting are essential for children’s healthy growth, and for the physical and mental wellbeing of both children and adults. In the context of exercise, music may promote behavioral change through increased exercise adherence and participation. The purpose of this study was to determine whether a movement-to-music video program could reduce sedentary behavior (SB) and increase PA in mother-child pairs in the home environment. A randomized controlled trial was conducted in the Pirkanmaa region, Finland, in 2014–2016. The participants consisted of 228 mother-child pairs (child age 5–7 years). The primary outcomes of interest were tri-axial accelerometer-derived SB and PA, which were measured in weeks one (baseline), two, and eight in both the intervention and control groups. Further, the mothers and children in the intervention group used a movement-to-music video program from the beginning of week two to the end of week eight. Secondary outcomes included self-reported screen time. The statistical methods employed comprised an intention-to-treat and linear mixed effects model design. No statistically significant differences between groups were found in primary or secondary outcomes. Among the children in the control group, light PA decreased significantly over time and screen time increased from 89 (standard deviation, SD 37) to 99 (SD 41) min/d. Among mothers and children in the intervention group, no statistical differences were found. In supplementary analysis, the children who stayed at home instead of attending daycare/preschool had on average 25 (95% confidence interval, CI 19–30) min/d more sedentary time and 11 (95% CI 8–14) min/d less moderate-to-vigorous PA than those who were at daycare/preschool. The higher body mass index of mothers was related with 5 (95% CI 2–7) min/d more sedentary time and 1 (95% CI 0–2) min/d less moderate-to-vigorous PA. The movement-to-music video program did not change the objectively measured SB or PA of the mother-child pairs. However, mothers and children seemed to be more sedentary at home, and therefore interventions for decreasing SB and increasing PA should be targeted in the home environment. PMID:28859091

Hay fever & homeopathy: a case series evaluation.

PubMed

Pandey, Vinita

2016-05-01

Seasonal allergic rhinitis (hay fever) is common and can considerably reduce the quality of life of sufferers. Despite the wide everyday application and promising results with homeopathy, scientific evidence of its effectiveness for most ailments is scarce. The assessment of the clinical effectiveness of homeopathic remedies in the alleviation of hay fever symptoms in a typical clinical setting. We performed a clinical observational study of eight patients in the treatment of hay fever symptoms over a two-year period (2012 and 2013) using Measure Yourself Medical Outcome Profile (MYMOP) self-evaluation questionnaires at baseline and again after two weeks and four weeks of homeopathic treatment. The individualized prescription - either a single remedy or multiple remedies - was based on the totality of each patient's symptoms. The average MYMOP scores for the eyes, nose, activity and wellbeing had improved significantly after two and four weeks of homeopathic treatment. The overall average MYMOP profile score at baseline was 3.83 (standard deviation, SD, 0.78). After 14 and 28 days of treatment the average score had fallen to 1.14 (SD, 0.36; P<0.001) and 1.06 (SD, 0.25; P<0.001) respectively. Individualized homeopathic treatment was associated with significant alleviation of hay fever symptoms, enabling the reduction in use of conventional treatment. The results presented in this study can be considered as a step towards a pilot pragmatic study that would use more robust outcome measures and include a larger number of patients prescribed a single or a multiple homeopathic prescription on an individualized basis. Copyright © 2016 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Multi-frequency EIT system with radially symmetric architecture: KHU Mark1.

PubMed

Oh, Tong In; Woo, Eung Je; Holder, David

2007-07-01

We describe the development of a multi-frequency electrical impedance tomography (EIT) system (KHU Mark1) with a single balanced current source and multiple voltmeters. It was primarily designed for imaging brain function with a flexible strategy for addressing electrodes and a frequency range from 10 Hz-500 kHz. The maximal number of voltmeters is 64, and all of them can simultaneously acquire and demodulate voltage signals. Each voltmeter measures a differential voltage between a pair of electrodes. All voltmeters are configured in a radially symmetric architecture in order to optimize the routing of wires and minimize cross-talk. We adopted several techniques from existing EIT systems including digital waveform generation, a Howland current generator with a generalized impedance converter (GIC), digital phase-sensitive demodulation and tri-axial cables. New features of the KHU Mark1 system include multiple GIC circuits to maximize the output impedance of the current source at multiple frequencies. The voltmeter employs contact impedance measurements, data overflow detection, spike noise rejection, automatic gain control and programmable data averaging. The KHU Mark1 system measures both in-phase and quadrature components of trans-impedances. By using a script file describing an operating mode, the system setup can be easily changed. The performance of the developed multi-frequency EIT system was evaluated in terms of a common-mode rejection ratio, signal-to-noise ratio, linearity error and reciprocity error. Time-difference and frequency-difference images of a saline phantom with a banana object are presented showing a frequency-dependent complex conductivity of the banana. Future design of a more innovative system is suggested including miniaturization and wireless techniques.

Chemotherapy and plasma adipokines level in patients with colorectal cancer.

PubMed

Słomian, Grzegorz; Świętochowska, Elżbieta; Nowak, Grzegorz; Pawlas, Krystyna; Żelazko, Aleksandra; Nowak, Przemysław

2017-04-12

Adipokines are molecules produced and secreted by adipose tissue and are linked to multiple malignancies. Adipokines can suppress or promote particular cell behaviors in different types of cancer. The aim of this study was to investigate the impact of chemotherapy on select adipokines in patients with colorectal cancer (CRC). Blood samples were collected from 42 patients with pathologically documented advanced CRC, who required palliative chemotherapy. Leptin, adiponectin, resistin and visfatin levels were measured by ELISA before and 3 months after the administration of chemotherapy. Among the 42 patients evaluated, 18 achieved a partial response (PR), 16 achieved stable disease (SD) and 8 patients experienced disease progression (PD). We found that 5-fluorouracil-based chemotherapy regimens significantly increased plasma levels of leptin and adiponectin and decreased plasma levels of resistin and visfatin in PR and SD patients, whereas the plasma levels of these molecules were not affected in PD patients. Furthermore, the mean plasma levels of leptin were significantly lower, and the mean plasma levels of resistin and visfatin were significantly greater in patients with PD compared with PR and SD both before and after chemotherapy treatment. We conclude that palliative chemotherapy in CRC patients, in addition to providing clinical benefits, positively affects cytokine production and secretion in PR and SD patients. Specifically, we found that palliative chemotherapy increased plasma levels of the anti-inflammatory adipokine adiponectin and decreased the plasma levels of visfatin and resistin, molecules known to promote angiogenesis and cancer cell proliferation in PR and SD patients. Moreover, the baseline values of leptin, visfatin and resistin might serve as prognostic indicators of a poor response to chemotherapy.