Photo-ionization rate coefficients for the rare gases
Pang, Xuexia
2005-01-01
By introducing the converting method from electron-impact ionization cross sections to rate coefficients through using a semi-experiential formula, we try to probe a semi-experiential formula for converting the photo-ionization cross sections into photo-ionization rate coefficient. It"s found that photo-ionization rate coefficient is direct proportion to photo-ionization cross sections, the rate S is related with light resource.
Pfrang, Christian; King, Martin D.; Braeckevelt, Mareike; Canosa-Mas, Carlos E.; Wayne, Richard P.
Experimental difficulties sometimes force modellers to use predicted rate coefficients for reactions of oxygenated volatile organic compounds (oVOCs). We examine here methods for making the predictions for reactions of atmospheric initiators of oxidation, NO 3, OH, O 3 and O( 3P), with unsaturated alcohols and ethers. Logarithmic correlations are found between measured rate coefficients and calculated orbital energies, and these correlations may be used directly to estimate rate coefficients for compounds where measurements have not been performed. To provide a shortcut that obviates the need to calculate orbital energies, structure-activity relations (SARs) are developed. Our SARs are tested for predictive power against compounds for which experimental rate coefficients exist, and their accuracy is discussed. Estimated atmospheric lifetimes for oVOCs are presented. The SARs for alkenols successfully predict key rate coefficients, and thus can be used to enhance the scope of atmospheric models incorporating detailed chemistry. SARs for the ethers have more limited applicability, but can still be useful in improving tropospheric models.
A nomogram for prediction of absorption rate coefficient
李玉红; 赵欣; 嵇晴; 徐建国; 孙瑞元
2004-01-01
Background Previous studies have suggested that nomogram can simplize complicated calculations of several varibles. A simple nomogram was constructed to estimate absorption rate coefficient (ka) by using the peak time (tpeak) and the elimination rate coefficient (ke) of drugs administered orally. Methods The nomogram was based on the plasma concentration-time (C-T) curve equation and the function relation between tpeak, ka and ke. A mathematical analysis was presented for the construction of single chart nomogram. To check the degree of accuracy of the developed nomogram, we used it to analyze retrospective profiles of 46 drugs and compared the ka values obtained graphically and those calculated by numerically solving the descriptive equation. In addition, we measured the carbocisteine concentration of 18 healthy volunteers by HPLC with fluorescence detection. To analyze performance error, the measured carbocisteine concentrations were compared with predicted concentrations by the ka obtained from the nomograms along with the other pharmacokinetic parameters. Results The estimated of ka values from nomograms were in very close proximity with the numerical values. The performance error was as follows: median performance error (MDPE) and median absolute performance error (MDAPE) were 1.32% and 18.15%, respectively. Conclusions The developed nomogram is accurate and reliable. The size of performance error meets the demand of clinical pharmacokinetics. Therefore, the nomograms can offer another convenient and easy method for rational individualized dosage regimens.
李继坤
2001-01-01
On the basis of the literatures［4-7］,the relation between exergy loss rate and refrigeration coefficient of a carnot refrigerator is derived.The various factors which affect the relation are analyzed.%在文献［4～7］的基础上，本文导出了卡诺制冷机的火用损率与制冷系数间的关系，并且分析了各种因素对该关系的影响。
Hagelaar, G J M; Pitchford, L C [Centre de Physique des Plasmas et de leurs Applications de Toulouse, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 9 (France)
2005-11-15
Fluid models of gas discharges require the input of transport coefficients and rate coefficients that depend on the electron energy distribution function. Such coefficients are usually calculated from collision cross-section data by solving the electron Boltzmann equation (BE). In this paper we present a new user-friendly BE solver developed especially for this purpose, freely available under the name BOLSIG+, which is more general and easier to use than most other BE solvers available. The solver provides steady-state solutions of the BE for electrons in a uniform electric field, using the classical two-term expansion, and is able to account for different growth models, quasi-stationary and oscillating fields, electron-neutral collisions and electron-electron collisions. We show that for the approximations we use, the BE takes the form of a convection-diffusion continuity-equation with a non-local source term in energy space. To solve this equation we use an exponential scheme commonly used for convection-diffusion problems. The calculated electron transport coefficients and rate coefficients are defined so as to ensure maximum consistency with the fluid equations. We discuss how these coefficients are best used in fluid models and illustrate the influence of some essential parameters and approximations.
Heart Rate Variability Analysis Using Threshold of Wavelet Package Coefficients
Kheder, G; Massoued, M Ben; Samet, M
2009-01-01
In this paper, a new efficient feature extraction method based on the adaptive threshold of wavelet package coefficients is presented. This paper especially deals with the assessment of autonomic nervous system using the background variation of the signal Heart Rate Variability HRV extracted from the wavelet package coefficients. The application of a wavelet package transform allows us to obtain a time-frequency representation of the signal, which provides better insight in the frequency distribution of the signal with time. A 6 level decomposition of HRV was achieved with db4 as mother wavelet, and the above two bands LF and HF were combined in 12 specialized frequencies sub-bands obtained in wavelet package transform. Features extracted from these coefficients can efficiently represent the characteristics of the original signal. ANOVA statistical test is used for the evaluation of proposed algorithm.
The HD+ dissociative recombination rate coefficient at low temperature
Wolf A.
2015-01-01
Full Text Available The effect of the rotational temperature of the ions is considered for low-energy dissociative recombination (DR of HD+. Merged beams measurements with HD+ ions of a rotational temperature near 300 K are compared to multichannel quantum defect theory calculations. The thermal DR rate coefficient for a Maxwellian electron velocity distribution is derived from the merged-beams data and compared to theoretical results for a range of rotational temperatures. Good agreement is found for the theory with 300 K rotational temperature. For a low-temperature plasma environment where also the rotational temperature assumes 10 K, theory predicts a considerably higher thermal DR rate coefficient. The origin of this is traced to predicted resonant structures of the collision-energy dependent DR cross section at few-meV collision energies for the particular case of HD+ ions in the rotational ground state.
The 95% confidence intervals of error rates and discriminant coefficients
Shuichi Shinmura
2015-02-01
Full Text Available Fisher proposed a linear discriminant function (Fisher’s LDF. From 1971, we analysed electrocardiogram (ECG data in order to develop the diagnostic logic between normal and abnormal symptoms by Fisher’s LDF and a quadratic discriminant function (QDF. Our four years research was inferior to the decision tree logic developed by the medical doctor. After this experience, we discriminated many data and found four problems of the discriminant analysis. A revised Optimal LDF by Integer Programming (Revised IP-OLDF based on the minimum number of misclassification (minimum NM criterion resolves three problems entirely [13, 18]. In this research, we discuss fourth problem of the discriminant analysis. There are no standard errors (SEs of the error rate and discriminant coefficient. We propose a k-fold crossvalidation method. This method offers a model selection technique and a 95% confidence intervals (C.I. of error rates and discriminant coefficients.
Cosmological Implications of the Uncertainty in H- Destruction Rate Coefficients
Glover, S C O; Jappsen, A K; Glover, Simon C.O.; Savin, Daniel W.; Jappsen, Anne-Katharina
2006-01-01
In primordial gas, molecular hydrogen forms primarily through associative detachment of H- and H, thereby destroying the H-. The H- anion can also be destroyed by a number of other reactions, most notably by mutual neutralization with protons. However, neither the associative detachment nor the mutual neutralization rate coefficients are well determined: both may be uncertain by as much as an order of magnitude. This introduces a corresponding uncertainty into the H2 formation rate, which may have cosmological implications. Here, we examine the effect that these uncertainties have on the formation of H2 and the cooling of protogalactic gas in a variety of situations. We show that the effect is particularly large for protogalaxies forming in previously ionized regions, affecting our predictions of whether or not a given protogalaxy can cool and condense within a Hubble time, and altering the strength of the ultraviolet background that is required to prevent collapse.
Thermodynamically based constraints for rate coefficients of large biochemical networks.
Vlad, Marcel O; Ross, John
2009-01-01
Wegscheider cyclicity conditions are relationships among the rate coefficients of a complex reaction network, which ensure the compatibility of kinetic equations with the conditions for thermodynamic equilibrium. The detailed balance at equilibrium, that is the equilibration of forward and backward rates for each elementary reaction, leads to compatibility between the conditions of kinetic and thermodynamic equilibrium. Therefore, Wegscheider cyclicity conditions can be derived by eliminating the equilibrium concentrations from the conditions of detailed balance. We develop matrix algebra tools needed to carry out this elimination, reexamine an old derivation of the general form of Wegscheider cyclicity condition, and develop new derivations which lead to more compact and easier-to-use formulas. We derive scaling laws for the nonequilibrium rates of a complex reaction network, which include Wegscheider conditions as a particular case. The scaling laws for the rates are used for clarifying the kinetic and thermodynamic meaning of Wegscheider cyclicity conditions. Finally, we discuss different ways of using Wegscheider cyclicity conditions for kinetic computations in systems biology.
Anderson-Witting transport coefficients for flows in general relativity
Ambrus, Victor E
2016-01-01
The transport coefficients induced by the Anderson-Witting approximation of the collision term in the relativistic Boltzmann equation are derived for close to equilibrium flows in general relativity. Using the tetrad formalism, it is shown that the expression for these coefficients is the same as that obtained on flat space-time, in agreement with the generalized equivalence principle.
Learning rates of lq coefficient regularization learning with gaussian kernel.
Lin, Shaobo; Zeng, Jinshan; Fang, Jian; Xu, Zongben
2014-10-01
Regularization is a well-recognized powerful strategy to improve the performance of a learning machine and l(q) regularization schemes with 0 regularization leads to a smooth estimator, while l(1) regularization leads to a sparse estimator. Then how the generalization capability of l(q) regularization learning varies with q is worthy of investigation. In this letter, we study this problem in the framework of statistical learning theory. Our main results show that implementing l(q) coefficient regularization schemes in the sample-dependent hypothesis space associated with a gaussian kernel can attain the same almost optimal learning rates for all 0 regularization learning are asymptotically identical for all 0 < q < ∞. Our finding tentatively reveals that in some modeling contexts, the choice of q might not have a strong impact on the generalization capability. From this perspective, q can be arbitrarily specified, or specified merely by other nongeneralization criteria like smoothness, computational complexity or sparsity.
Automatic estimation of pressure-dependent rate coefficients
Allen, Joshua W.
2012-01-01
A general framework is presented for accurately and efficiently estimating the phenomenological pressure-dependent rate coefficients for reaction networks of arbitrary size and complexity using only high-pressure-limit information. Two aspects of this framework are discussed in detail. First, two methods of estimating the density of states of the species in the network are presented, including a new method based on characteristic functional group frequencies. Second, three methods of simplifying the full master equation model of the network to a single set of phenomenological rates are discussed, including a new method based on the reservoir state and pseudo-steady state approximations. Both sets of methods are evaluated in the context of the chemically-activated reaction of acetyl with oxygen. All three simplifications of the master equation are usually accurate, but each fails in certain situations, which are discussed. The new methods usually provide good accuracy at a computational cost appropriate for automated reaction mechanism generation. This journal is © the Owner Societies.
Recommended Thermal Rate Coefficients for the C + H3 + Reaction and Some Astrochemical Implications
Vissapragada, S.; Buzard, C. F.; Miller, K. A.; O'Connor, A. P.; de Ruette, N.; Urbain, X.; Savin, D. W.
2016-11-01
We incorporate our experimentally derived thermal rate coefficients for C + {{{H}}}3+ forming CH+ and CH2 + into a commonly used astrochemical model. We find that the Arrhenius-Kooij equation typically used in chemical models does not accurately fit our data and instead we use a more versatile fitting formula. At a temperature of 10 K and a density of 104 cm-3, we find no significant differences in the predicted chemical abundances, but at higher temperatures of 50, 100, and 300 K we find up to factor of 2 changes. In addition, we find that the relatively small error on our thermal rate coefficients, ˜15%, significantly reduces the uncertainties on the predicted abundances compared to those obtained using the currently implemented Langevin rate coefficient with its estimated factor of 2 uncertainty.
Vissapragada, S; Miller, K A; O'Connor, A P; de Ruette, N; Urbain, X; Savin, D W
2016-01-01
We have incorporated our experimentally derived thermal rate coefficients for C + H$_3^+$ forming CH$^+$ and CH$_2^+$ into a commonly used astrochemical model. We find that the Arrhenius-Kooij equation typically used in chemical models does not accurately fit our data and use instead a more versatile fitting formula. At a temperature of 10 K and a density of 10$^4$ cm$^{-3}$, we find no significant differences in the predicted chemical abundances, but at higher temperatures of 50, 100, and 300 K we find up to factor of 2 changes. Additionally, we find that the relatively small error on our thermal rate coefficients, $\\sim15\\%$, significantly reduces the uncertainties on the predicted abundances compared to those obtained using the currently implemented Langevin rate coefficient with its estimated factor of 2 uncertainty.
Shizgal, Bernie D.
2016-12-01
There has been intense interest for several decades by different research groups to accurately model the temperature dependence of a large number of nuclear reaction rate coefficients for both light and heavy nuclides. The rate coefficient, k(T) , is given by the Maxwellian average of the reactive cross section expressed in terms of the astrophysical factor, S(E) , which for nonresonant reactions is generally written as a power series in the relative energy E. A computationally efficient algorithm for the temperature dependence of nuclear reaction rate coefficients is required for fusion reactor research and for models of nucleosynthesis and stellar evolution. In this paper, an accurate analytical expression for the temperature dependence of nuclear reaction rate coefficients is provided in terms of τ = 3(b / 2) 2/3 or equivalently, T - 1/3 , where b = B /√{kB T }, B is the Gamow factor and kB is the Boltzmann constant. The methodology is appropriate for all nonresonant nuclear reactions for which S(E) can be represented as a power series in E. The explicit expression for the rate coefficient versus temperature is derived with the asymptotic expansions of the moments of w(E) = exp(- E /kB T - B /√{ E }) in terms of τ. The zeroth order moment is the familiar Gaussian approximation to the rate coefficient. Results are reported for the representative reactions D(d, p)T, D(d, n)3He and 7Li(p, α) α and compared with several different fitting procedures reported in the literature.
Reciprocal relations for transmission coefficients - Theory and application
Qu, Jianmin; Achenbach, Jan D.; Roberts, Ronald A.
1989-01-01
The authors present a rigorous proof of certain intuitively plausible reciprocal relations for time harmonic plane-wave transmission and reflection at the interface between a fluid and an anisotropic elastic solid. Precise forms of the reciprocity relations for the transmission coefficients and for the transmitted energy fluxes are derived, based on the reciprocity theorem of elastodynamics. It is shown that the reciprocity relations can be used in conjunction with measured values of peak amplitudes for transmission through a slab of the solid (water-solid-water) to obtain the water-solid coefficients. Experiments were performed for a slab of a unidirectional fiber-reinforced composite. Good agreement of the experimentally measured transmission coefficients with theoretical values was obtained.
On the relations among best approximation and Fourier coefficients
YU DanSheng; ZHOU Ping; ZHOU SongPing
2008-01-01
We discuss the relations among the best approximation En(f) and the Fourier coefficients {(f)(n) + f(-n)}∞n=0 ∈ MVBVS*,where MVBVS* is the class of the so-called Strong Mean Value Bounded Variation Sequences.
Relation between spectroscopic constants with limited Dunham coefficients
Suresh Chandra
2005-12-01
Statement of Kaur and Mahajan [1] about the definition of used by Chandra [2] is not correct. Even if we take $ = w_{2}^{2}r_{e}^{2}/2D_{e}$, the relation between and (=8ωe/) is obtained as = 4.21452856G, provided the vibrational energy of a diatomic molecule is expressed in terms of limited Dunham coefficients, 10, 20, 01 and 11. This relation is still different from that of Kaur and Mahajan [3].
Jameson, A. R.
1990-01-01
The relationship between the rainfall rate (R) obtained from radiometric brightness temperatures and the extinction coefficient (k sub e) is investigated by computing the values of k sub e over a wide range of rainfall rates, for frequencies from 3 to 25 GHz. The results show that the strength of the relation between the R and the k sub e values exhibits considerable variation for frequencies at this range. Practical suggestions are made concerning the selection of particular frequencies for rain measurements to minimize the error in R determinations.
Determination of sedimentation rates and absorption coefficient of ...
DR. MIKE HORSFALL
showed a decrease in the density of the carbonates and also correlated with the decrease in the mass (and ... Many chemical reactions form separable solid phase ... The precipitates were ... Zn2+ had the highest sedimentation rate constants,.
Expressions for the Evaporation and Condensation Coefficients in the Hertz-Knudsen Relation.
Persad, Aaron H; Ward, Charles A
2016-07-27
Although the Hertz-Knudsen (HK) relation is often used to correlate evaporation data, the relation contains two empirical parameters (the evaporation and condensation coefficients) that have inexplicably been found to span 3 orders of magnitude. Explicit expressions for these coefficients have yet to be determined. This review will examine sources of error in the HK relation that have led to the coefficients' scatter. Through an examination of theoretical, experimental, and molecular dynamics simulation studies of evaporation, this review will show that the HK relation is incomplete, since it is missing an important physical concept: the coupling between the vapor and liquid phases during evaporation. The review also examines a modified HK relation, obtained from the quantum-mechanically based statistical rate theory (SRT) expression for the evaporation flux and applying a limit to it in which the thermal energy is dominant. Explicit expressions for the evaporation and condensation coefficients are defined in this limit, with the surprising result that the coefficients are not bounded by unity. An examination is made with 127 reported evaporation experiments of water and of ethanol, leading to a new physical interpretation of the coefficients. The review concludes by showing how seemingly small simplifications, such as assuming thermal equilibrium across the liquid-vapor interface during evaporation, can lead to the erroneous predictions from the HK relation that have been reported in the literature.
Simulating the market coefficient of relative risk aversion
Samih Antoine Azar
2014-12-01
Full Text Available In this paper, expected utility, defined by a Taylor series expansion around expected wealth, is maximized. The coefficient of relative risk aversion (CRRA that is commensurate with a 100% investment in the risky asset is simulated. The following parameters are varied: the riskless return, the market standard deviation, the market stock premium, and the skewness and the kurtosis of the risky return. Both the high extremes and the low extremes are considered. With these figures, the upper bound of the market CRRA is 3.021 and the lower bound is 0.466. Log utility, which corresponds to a CRRA of 1, is not excluded.
Coupling coefficient for TEA CO2 laser propulsion with variable pulse repetition rate
Yijun Zheng; Rongqing Tan; Donglei Wang; Guang Zheng; Changjun Ke; Kuohai Zhang; Chongyi Wan; Jin Wu
2006-01-01
@@ Because pulse repetition rate affected directly the momentum coupling coefficient of transversely excited atmospheric (TEA) CO2 laser propulsion, a double pulse trigger, controlling high voltage switch of laser excitation circuit, was designed. The pulse interval ranged between 5 and 100 ms. The momentum coupling coefficient for air-breathing mode laser propulsion was studied experimentally. It was found that the momentum coupling coefficient decreased with the pulse repetition rate increasing.
Koning, Camiel de; Straetmans, S.
1997-01-01
textabstractWe investigate the potential presence of time variation in the coefficients of the ''Fama regression'' for Uncovered Interest Rate Parity. We implement coefficient constancy tests, rolling regression techniques, and stochastic coefficient models based on state space modelling. Among six major US bilateral exchange rates we find significant evidence for stochastic time variation. Using the statistical equivalence between stochastically varying coefficients and conditional heterosce...
Dielectronic recombination rate coefficients to excited states of Be-like oxygen
Murakami, Izumi; Safronova, Ulyana I.; Kato, Takako
2001-05-01
We have calculated energy levels, radiative transition probabilities, and autoionization rates for Be-like oxygen (O{sup 4+}) including ls{sup 2}2lnl' (n=2 - 8, l {<=} n - 1) and 1s{sup 2}3l'nl (n=3 - 6, l {<=} n - l) states by multi-configurational Hartree-Fock method (Cowan code) and perturbation theory Z-expansion method (MZ code). The state selective dielectronic recombination rate coefficients to excited states of Be-like O ions are obtained. Configuration mixing plays an important role for the principal quantum number n distribution of the dielectronic recombination rate coefficients for 2snl (n {<=} 5) levels at low electron temperature. The orbital angular momentum quantum number l distribution of the rate coefficients shows a peak at l = 4. The total dielectronic recombination rate coefficient is derived as a function of electron temperature. (author)
Table for constructing the spin coefficients in general relativity
Cocke, W. J.
1989-07-15
The spin coefficients in spinor calculus in Riemannian space-time are linear functions of the curls of the connecting quantities (the Infeld--Van der Waerden symbols). We show that in the Newman-Penrose formalism the expressions for the spin coefficients are quite manageable, if they are written in terms of the Newman-Penrose tetrad vectors. We present a table of the components of the spin coefficients explicitly in terms of the curls of the individual tetrad vectors.
Three-fluid plasmas in star formation II. Momentum transfer rate coefficients
Pinto, Cecilia
2008-01-01
The charged component of the insterstellar medium consists of atomic and molecular ions, electrons, and charged dust grains, coupled to the local Galactic magnetic field. Collisions between neutral particles (mostly atomic or molecular hydrogen) and charged species, and between the charged species themselves, affect the magnetohydrodynamical behaviour of the medium and the dissipation of electric currents. The friction force due to elastic collisions between particles of different species in the multi-component interstellar plasma is a nonlinear function of the temperature of each species and the Mach number of the relative drift velocity. The aim of this paper is to provide an accurate and, as far as possible, complete set of momentum transfer rate coefficients for magnetohydrodynamical studies of the interstellar medium. Momentum transfer rates are derived from available experimental data and theoretical calculations of cross sections within the classic approach developed by Boltzmann and Langevin for a wid...
Collision rate coefficient for charged dust grains in the presence of linear shear
Yang, Huan; Hogan, Christopher J.
2017-09-01
Like and oppositely charged particles or dust grains in linear shear flows are often driven to collide with one another by fluid and/or electrostatic forces, which can strongly influence particle-size distribution evolution. In gaseous media, collisions in shear are further complicated because particle inertia can influence differential motion. Expressions for the collision rate coefficient have not been developed previously which simultaneously account for the influences of linear shear, particle inertia, and electrostatic interactions. Here, we determine the collision rate coefficient accounting for the aforementioned effects by determining the collision area, i.e., the area of the plane perpendicular to the shear flow defining the relative initial locations of particles which will collide with one another. Integration of the particle flux over this area yields the collision rate. Collision rate calculations are parametrized as an enhancement factor, i.e., the ratio of the collision rate considering potential interactions and inertia to the traditional collision rate considering laminar shear only. For particles of constant surface charge density, the enhancement factor is found dependent only on the Stokes number (quantifying particle inertia), the electrostatic energy to shear energy ratio, and the ratio of colliding particle radii. Enhancement factors are determined for Stokes numbers in the 0-10 range and energy ratios up to 5. Calculations show that the influences of both electrostatic interactions and inertia are significant; for inertialess (St =0 ) equal-sized and oppositely charged particles, we find that even at energy ratios as low as 0.2, enhancement factors are in excess of 2. For the same situation but like-charged particles, enhancement factors fall below 0.5. Increasing the Stokes number acts to mitigate the influence of electrostatic potentials for both like and oppositely charged particles; i.e., inertia reduces the enhancement factor for
Cross Sections and Rate Coefficients for Vibrational Excitation of HeH+ Molecule by Electron Impact
Mehdi Ayouz
2016-12-01
Full Text Available Cross sections and thermally-averaged rate coefficients for vibration (de-excitation of HeH + by an electron impact are computed using a theoretical approach that combines the multi-channel quantum defect theory and the UK R-matrix code. Fitting formulas with a few numerical parameters are derived for the obtained rate coefficients. The interval of applicability of the formulas is from 40 to 10,000 K.
C. de Koning (Camiel); S. Straetmans
1997-01-01
textabstractWe investigate the potential presence of time variation in the coefficients of the ''Fama regression'' for Uncovered Interest Rate Parity. We implement coefficient constancy tests, rolling regression techniques, and stochastic coefficient models based on state space modelling. Among six
C. de Koning (Camiel); S. Straetmans
1997-01-01
textabstractWe investigate the potential presence of time variation in the coefficients of the ''Fama regression'' for Uncovered Interest Rate Parity. We implement coefficient constancy tests, rolling regression techniques, and stochastic coefficient models based on state space modelling. Among six
Verifying reciprocal relations for experimental diffusion coefficients in multicomponent mixtures
Medvedev, Oleg; Shapiro, Alexander
2003-01-01
The goal of the present study is to verify the agreement of the available data on diffusion in ternary mixtures with the theoretical requirement of linear non-equilibrium thermodynamics consisting in symmetry of the matrix of the phenomenological coefficients. A common set of measured diffusion...... coefficients for a three-component mixture consists of four Fickian diffusion coefficients, each being reported separately. However, the Onsager theory predicts the existence of only three independent coefficients, as one of them disappears due to the symmetry requirement. Re-calculation of the Fickian...... extended sets of experimental data and reliable thermodynamic models were available. The sensitivity of the symmetry property to different thermodynamic parameters of the models was also checked. (C) 2003 Elsevier Science B.V. All rights reserved....
Viggiano, Albert A; Friedman, Jeffrey F; Shuman, Nicholas S; Miller, Thomas M; Schaffer, Linda C; Troe, Jürgen
2010-05-21
Thermal electron attachment to C(60) has been studied by relative rate measurements in a flowing afterglow Langmuir probe apparatus. The rate coefficients of the attachment k(1) are shown to be close to 10(-6) cm(3) s(-1) with a small negative temperature coefficient. These results supersede measurements from the 1990s which led to much smaller values of k(1) with a large positive temperature coefficient suggesting an activation barrier. Theoretical modeling of k(1) in terms of generalized Vogt-Wannier capture theory shows that k(1) now looks more consistent with measurements of absolute attachment cross sections sigma(at) than before. The comparison of capture theory and experimental rate or cross section data leads to empirical correction factors, accounting for "intramolecular vibrational relaxation" or "electron-phonon coupling," which reduce k(1) below the capture results and which, on a partial wave-selected level, decrease with increasing electron energy.
Song, L.; Balakrishnan, N.; Walker, K. M.; Stancil, P. C.; Thi, W. F.; Kamp, I.; van der Avoird, A.; Groenenboom, G. C.
2015-11-01
We present calculated rate coefficients for ro-vibrational transitions of CO in collisions with H atoms for a gas temperature range of 10 K ≤ T ≤ 3000 K, based on the recent three-dimensional ab initio H-CO interaction potential of Song et al. Rate coefficients for ro-vibrational v=1,j=0-30\\to v\\prime =0,j\\prime transitions were obtained from scattering cross sections previously computed with the close-coupling (CC) method by Song et al. Combining these with the rate coefficients for vibrational v=1-5\\to v\\prime \\lt v quenching obtained with the infinite-order sudden approximation, we propose a new extrapolation scheme that yields the rate coefficients for ro-vibrational v=2-5,j=0-30\\to v\\prime ,j\\prime de-excitation. Cross sections and rate coefficients for ro-vibrational v=2,j=0-30\\to v\\prime =1,j\\prime transitions calculated with the CC method confirm the effectiveness of this extrapolation scheme. Our calculated and extrapolated rates are very different from those that have been adopted in the modeling of many astrophysical environments. The current work provides the most comprehensive and accurate set of ro-vibrational de-excitation rate coefficients for the astrophysical modeling of the H-CO collision system. The application of the previously available and new data sets in astrophysical slab models shows that the line fluxes typically change by 20%-70% in high temperature environments (800 K) with an H/H2 ratio of 1; larger changes occur for lower temperatures.
Partial and Total Dielectronic Recombination rate coefficients for W73+ to W56+
Preval, S P; O'Mullane, M G
2016-01-01
Dielectronic recombination (DR) is a key atomic process which affects the spectroscopic diagnostic modelling of tungsten, most of whose ionization stages will be found somewhere in the ITER fusion reactor: in the edge, divertor, or core plasma. Accurate DR data is sparse while complete DR coverage is unsophisticated (e.g. average-atom or Burgess General Formula) as illustrated by the large uncertainties which currently exist in the tungsten ionization balance. To this end, we present a series of partial final state-resolved and total DR rate coefficients for W73+ to W56+ Tungsten ions. This is part of a wider effort within The Tungsten Project to calculate accurate dielectronic recombination rate coefficients for the tungsten isonuclear sequence for use in collisional-radiative modelling of finite-density tokamak plasmas. The recombination rate coefficients have been calculated with autostructure using kappa-averaged relativistic wavefunctions in level resolution (intermediate coupling) and configuration reso...
Direct access to dithiobenzoate RAFT agent fragmentation rate coefficients by ESR spin-trapping.
Ranieri, Kayte; Delaittre, Guillaume; Barner-Kowollik, Christopher; Junkers, Thomas
2014-12-01
The β-scission rate coefficient of tert-butyl radicals fragmenting off the intermediate resulting from their addition to tert-butyl dithiobenzoate-a reversible addition-fragmentation chain transfer (RAFT) agent-is estimated via the recently introduced electron spin resonance (ESR)-trapping methodology as a function of temperature. The newly introduced ESR-trapping methodology is critically evaluated and found to be reliable. At 20 °C, a fragmentation rate coefficient of close to 0.042 s(-1) is observed, whereas the activation parameters for the fragmentation reaction-determined for the first time-read EA = 82 ± 13.3 kJ mol(-1) and A = (1.4 ± 0.25) × 10(13) s(-1) . The ESR spin-trapping methodology thus efficiently probes the stability of the RAFT adduct radical under conditions relevant for the pre-equilibrium of the RAFT process. It particularly indicates that stable RAFT adduct radicals are indeed formed in early stages of the RAFT poly-merization, at least when dithiobenzoates are employed as controlling agents as stipulated by the so-called slow fragmentation theory. By design of the methodology, the obtained fragmentation rate coefficients represent an upper limit. The ESR spin-trapping methodology is thus seen as a suitable tool for evaluating the fragmentation rate coefficients of a wide range of RAFT adduct radicals. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Suleimanov, Yury V; Aoiz, F Javier; Guo, Hua
2016-11-03
This Feature Article presents an overview of the current status of ring polymer molecular dynamics (RPMD) rate theory. We first analyze the RPMD approach and its connection to quantum transition-state theory. We then focus on its practical applications to prototypical chemical reactions in the gas phase, which demonstrate how accurate and reliable RPMD is for calculating thermal chemical reaction rate coefficients in multifarious cases. This review serves as an important checkpoint in RPMD rate theory development, which shows that RPMD is shifting from being just one of recent novel ideas to a well-established and validated alternative to conventional techniques for calculating thermal chemical rate coefficients. We also hope it will motivate further applications of RPMD to various chemical reactions.
Shim S.M.
2012-01-01
Full Text Available The performance of the CO2 absorber column using mono-ethanolamine (MEA solution as chemical solvent are predicted by a One-Dimensional (1-D rate based model in the present study. 1-D Mass and heat balance equations of vapor and liquid phase are coupled with interfacial mass transfer model and vapor-liquid equilibrium model. The two-film theory is used to estimate the mass transfer between the vapor and liquid film. Chemical reactions in MEA-CO2-H2O system are considered to predict the equilibrium pressure of CO2 in the MEA solution. The mathematical and reaction kinetics models used in this work are calculated by using in-house code. The numerical results are validated in the comparison of simulation results with experimental and simulation data given in the literature. The performance of CO2 absorber column is evaluated by the 1-D rate based model using various reaction rate coefficients suggested by various researchers. When the rate of liquid to gas mass flow rate is about 8.3, 6.6, 4.5 and 3.1, the error of CO2 loading and the CO2 removal efficiency using the reaction rate coefficients of Aboudheir et al. is within about 4.9 % and 5.2 %, respectively. Therefore, the reaction rate coefficient suggested by Aboudheir et al. among the various reaction rate coefficients used in this study is appropriate to predict the performance of CO2 absorber column using MEA solution. [Acknowledgement. This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF, funded by the Ministry of Education, Science and Technology (2011-0017220].
On some binomial coefficients related to the evaluation of tan(nx)
Ma, Shi-Mei
2012-01-01
The purpose of this paper is to study some binomial coefficients which are related to the evaluation of tan(nx). We mainly present a connection between these binomial coefficients and the coefficients of a family of derivative polynomials for tangent and secant.
Perez, Pedro B.; Hamawi, John N.
2017-09-01
Nuclear power plant radiation protection design features are based on radionuclide source terms derived from conservative assumptions that envelope expected operating experience. Two parameters that significantly affect the radionuclide concentrations in the source term are failed fuel fraction and effective fission product appearance rate coefficients. Failed fuel fraction may be a regulatory based assumption such as in the U.S. Appearance rate coefficients are not specified in regulatory requirements, but have been referenced to experimental data that is over 50 years old. No doubt the source terms are conservative as demonstrated by operating experience that has included failed fuel, but it may be too conservative leading to over-designed shielding for normal operations as an example. Design basis source term methodologies for normal operations had not advanced until EPRI published in 2015 an updated ANSI/ANS 18.1 source term basis document. Our paper revisits the fission product appearance rate coefficients as applied in the derivation source terms following the original U.S. NRC NUREG-0017 methodology. New coefficients have been calculated based on recent EPRI results which demonstrate the conservatism in nuclear power plant shielding design.
Neufeld, David A
2009-01-01
An artificial neural network (ANN) is investigated as a tool for estimating rate coefficients for the collisional excitation of molecules. The performance of such a tool can be evaluated by testing it on a dataset of collisionally-induced transitions for which rate coefficients are already known: the network is trained on a subset of that dataset and tested on the remainder. Results obtained by this method are typically accurate to within a factor ~ 2.1 (median value) for transitions with low excitation rates and ~ 1.7 for those with medium or high excitation rates, although 4% of the ANN outputs are discrepant by a factor of 10 more. The results suggest that ANNs will be valuable in extrapolating a dataset of collisional rate coefficients to include high-lying transitions that have not yet been calculated. For the asymmetric top molecules considered in this paper, the favored architecture is a cascade-correlation network that creates 16 hidden neurons during the course of training, with 3 input neurons to ch...
Shizgal, Bernie D.
2016-08-01
Nonclassical quadratures based on a new set of half-range polynomials, Tn(x) , orthogonal with respect to w(x) =e - x - b /√{ x } for x ∈ [ 0 , ∞) are employed in the efficient calculation of the nuclear fusion reaction rate coefficients from cross section data. The parameter b = B /√{kB T } in the weight function is temperature dependent and B is the Gamow factor. The polynomials Tn(x) satisfy a three term recurrence relation defined by two sets of recurrence coefficients, αn and βn. These recurrence coefficients define in turn the tridiagonal Jacobi matrix whose eigenvalues are the quadrature points and the weights are calculated from the first components of the eigenfunctions. For nonresonant nuclear reactions for which the astrophysical function can be expressed as a lower order polynomial in the relative energy, the convergence of the thermal average of the reactive cross section with this nonclassical quadrature is extremely rapid requiring in many cases 2-4 quadrature points. The results are compared with other libraries of nuclear reaction rate coefficient data reported in the literature.
Cranor, W.L.; Alvarez, D.A.; Huckins, J.N.; Petty, J.D.
2009-01-01
To fully utilize semipermeable membrane devices (SPMDs) as passive samplers in air monitoring, data are required to accurately estimate airborne concentrations of environmental contaminants. Limited uptake rate constants (kua) and no SPMD air partitioning coefficient (Ksa) existed for vapor-phase contaminants. This research was conducted to expand the existing body of kinetic data for SPMD air sampling by determining kua and Ksa for a number of airborne contaminants including the chemical classes: polycyclic aromatic hydrocarbons, organochlorine pesticides, brominated diphenyl ethers, phthalate esters, synthetic pyrethroids, and organophosphate/organosulfur pesticides. The kuas were obtained for 48 of 50 chemicals investigated and ranged from 0.03 to 3.07??m3??g-1??d-1. In cases where uptake was approaching equilibrium, Ksas were approximated. Ksa values (no units) were determined or estimated for 48 of the chemicals investigated and ranging from 3.84E+5 to 7.34E+7. This research utilized a test system (United States Patent 6,877,724 B1) which afforded the capability to generate and maintain constant concentrations of vapor-phase chemical mixtures. The test system and experimental design employed gave reproducible results during experimental runs spanning more than two years. This reproducibility was shown by obtaining mean kua values (n??=??3) of anthracene and p,p???-DDE at 0.96 and 1.57??m3??g-1??d-1 with relative standard deviations of 8.4% and 8.6% respectively.
Electron Impact Ionization cross sections and rate coefficients for α-tetra hydro furfuryl alcohol
Kumar, Neeraj; Pal, Satyendra
2013-09-01
α - tetrahydrofurfuryl alcohol (THFA; C5H10O2) is an aromatic compound having the molecular structure similar to that of 2-deoxy-D-ribose (deoxyribose). This molecule has attracted enormous interest in the field of research because its electron charge cloud possesses a quite significant spatial extent (dipole polarizability, α = 70.18 au) and has a relatively strong permanent dipole moment (μ ~ 2D). In the present work, we have extended and generalized the modified Jain-Khare semi-empirical formalism for the evaluation of the total ionization cross sections corresponding to the formation of the cations in the electron impact ionization of molecules to the electron impact ionization of α-tetrahydrofurfuryl alcohol (THFA; C5H10O2) , in the energy range varying from ionization threshold to 1000 eV. The evaluated cross sections revealed a reasonably good agreement with the experimental and theoretical data, wherever available. We have also calculated the ionization rate coefficients as a function of electron energy, using the evaluated total ionization cross sections and the Maxwell-Boltzmann distribution.
On the influence of collisional rate coefficients on the water vapour excitation
Daniel, F; Cernicharo, J; Dubernet, M -L; Faure, A
2012-01-01
Water is a key molecule in many astrophysical studies. Its high dipole moment makes this molecule to be subthermally populated under the typical conditions of most astrophysical objects. This motivated the calculation of various sets of collisional rate coefficients (CRC) for H$_2$O (with He or H$_2$) which are necessary to model its rotational excitation and line emission. We performed accurate non--local non--LTE radiative transfer calculations using different sets of CRC in order to predict the line intensities from transitions that involve the lowest energy levels of H$_2$O (E $<$ 900 K). The results obtained from the different CRC sets are then compared using line intensity ratio statistics. For the whole range of physical conditions considered in this work, we obtain that the intensities based on the quantum and QCT CRC are in good agreement. However, at relatively low H$_2$ volume density ($n$(H$_2$) $<$ 10$^7$ cm$^{-3}$) and low water abundance ($\\chi$(H$_2$O) $<$ 10$^{-6}$), these physical c...
Rate coefficients of open shell molecules and radicals: $R$-matrix method
JASMEET SINGH; K L BALUJA; GAGANDEEP LONGIANY
2017-05-01
The open shell molecules with even number of electrons have $\\pi^2$ or $\\pi^{2}_{g}$ ground-state electronic configuration. Several homonuclear diatomic molecules like $\\rm{O_2, S_2, B_2}$ have $\\pi^{2}_{g}$ ground state in the $D_{\\infty h}$ point group and heteronuclear diatomic radicals like PH, NH, SO have $\\pi^2$ ground state in the $C_{\\infty v}$ point group. We have computed and presented here the rate coefficient of these open shell molecules $\\rm{(O_2, S_2, B_2)}$ and radicals (PH, NH,SO) from the results of our previous studies using a well-established $\\it {ab-initio}$ formalism: the $R$-matrix method. The rate coefficients for elastic and electron-excited processes are studied over a wide electron temperature range.
On the validity of the Arrhenius equation for electron attachment rate coefficients.
Fabrikant, Ilya I; Hotop, Hartmut
2008-03-28
The validity of the Arrhenius equation for dissociative electron attachment rate coefficients is investigated. A general analysis allows us to obtain estimates of the upper temperature bound for the range of validity of the Arrhenius equation in the endothermic case and both lower and upper bounds in the exothermic case with a reaction barrier. The results of the general discussion are illustrated by numerical examples whereby the rate coefficient, as a function of temperature for dissociative electron attachment, is calculated using the resonance R-matrix theory. In the endothermic case, the activation energy in the Arrhenius equation is close to the threshold energy, whereas in the case of exothermic reactions with an intermediate barrier, the activation energy is found to be substantially lower than the barrier height.
Gas-phase ozonolysis of β-ocimene: Temperature dependent rate coefficients and product distribution
Gaona-Colmán, Elizabeth; Blanco, María B.; Barnes, Ian; Teruel, Mariano A.
2016-12-01
Rate coefficients for the reaction of β-ocimene with O3 molecules have been determined over the temperature range 288-311 K at 750 Torr total pressure of nitrogen using the relative rate technique. The investigations were performed in a large volume reaction vessel using long-path in-situ Fourier transformed infrared (FTIR) spectroscopy to monitor the reactants and products. A value of k(β-ocimene + O3) = (3.74 ± 0.92) × 10-16 cm3 molecule-1 s-1 has been obtained for the reaction at 298 K. The temperature dependence of the reaction is best described by the Arrhenius expression k = (1.94 ± 0.02) × 10-14 exp [(-1181 ± 51)/T] cm3 molecule-1 s-1. In addition, a product study has been carried out at 298 K in 750 Torr of synthetic air and the following products with yields in molar % were observed: formaldehyde (36 ± 2), acetone (15 ± 1), methylglyoxal (9.5 ± 0.4) and hydroxyacetone (19 ± 1). The formation of formaldehyde can be explained by the addition of O3 to the C1sbnd C2 double bond of the β-ocimene. Addition of O3 to the C6sbnd C7 double bond leads to the formation of acetone and the CH3C·(OO·)CH3 biradical, which can through isomerization/stabilization form methylglyoxal (hydroperoxide channel) and hydroxyacetone. The formed products will contribute to the formation of PAN and derivatives in polluted environments and also the oxidation capacity of the atmosphere.
Orlov Vladimir Aleksandrovich
2012-10-01
The software is also capable of generating graphs (curves to describe the relations in question. The proposed methodology and the software designated for the calculation of Chezy and roughness coefficients makes it possible for users to identify the hydraulic properties of pipelines made of advanced materials or having advanced coatings. The availability of the above information is to optimize the selection of the pipeline repair material on the basis of the assessment of hydraulic compatibility between the sections of the pipeline in operation and those being repaired.
Recombination and Electron Impact Excitation Rate Coefficients for S XV and S XVI
Mahmood, S.; Ali, S.; Orban, I.; Tashenov, S.; Lindroth, E.; Schuch, R.
2012-08-01
Recombination and electron impact excitation of S14+ and S15+ ions was measured at the Stockholm refrigerated electron beam ion trap. The collision energy range was 1.4-3 keV, in which we covered the KLL, KLM, KLN, and KLO dielectronic recombination resonances resulting in S13+ and S14+ ions. The recombination rates were obtained by detecting the charge state distribution with a newly developed time-of-flight technique. Resonance energies and cross-sections calculated within the relativistic many-body perturbation theory for S15+ agree well with the experimental data. The temperature-dependent rate coefficients were extracted from the measured rates and compared with calculations from the literature used for studies of collisionally ionized astrophysical plasmas. Good agreement for S15+ was obtained, while the plasma rates for S14+ were 23% lower than the current published values. In addition to the time-of-flight spectra, the X-ray spectra, produced mainly by photo-recombination and excitation, were also collected. The combination of these two measurements allowed us to separate the photo-recombination and the excitation spectra, and the excitation rate coefficients for summed intensities with known fractions of S14+ and S15+ ions were extracted.
Savin, D W
1999-01-01
Using published measurements of dielectronic recombination (DR) resonance strengths and energies for C V to C IV and O VIII to O VII, we have calculated the DR rate coefficient for these ions. Our derived rates are in good agreement with multiconfiguration, intermediate-coupling and multiconfiguration, fully-relativistic calculations as well as with most LS coupling calculations. Our results are not in agreement with the recommended DR rates commonly used for modeling cosmic plasmas. We have used theoretical radiative recombination (RR) rates in conjunction with our derived DR rates to produce a total recombination rate for comparison with unified RR+DR calculations in LS coupling. Our results are not in agreement with undamped, unified calculations for C V but are in reasonable agreement with damped, unified calculations for O VIII. For C V, the Burgess general formula (GF) yields a rate which is in very poor agreement with our derived rate. The Burgess & Tworkowski modification of the GF yields a rate w...
Dose Rate and Mass Attenuation Coefficients of Gamma Ray for Concretes
Abdel-Latif, A A; Kansouh, W A; El-Sayed, F H
2003-01-01
This work is concerned with the study of the leakage gamma ray dose and mass attenuation coefficients for ordinary, basalt and dolomite concretes made from local ores. Concretes under investigation were constructed from gravel, basalt and dolomite ores, and then reconstructed with the addition of 3% steel fibers by weight. Measurements were carried out using a collimated beam from sup 6 sup 0 Co gamma ray source and sodium iodide (3x3) crystal with the genie 2000 gamma spectrometer. The obtained fluxes were transformed to gamma ray doses and displayed in the form of gamma ray dose rates distribution. The displayed curves were used to estimate the linear attenuation coefficients (mu), the relaxation lengths (lambda), half value layer (t sub 1 /2) and tenth value layer (t sub 1 /10). Also, The total mass attenuation coefficients of gamma ray have been calculated to the concerned concretes using XCOM (version 3.1) program and database elements cross sections from Z=1 to 100 at energies from 10 keV to 100 MeV. In...
Stolyarov, D.; Polyakova, E.; Bezel, I.; Wittig, C.
2002-05-01
Rate coefficients k( E) for photoinitiated NO 2 unimolecular decomposition have been obtained by recording the product NO laser-induced fluorescence signal intensity versus the delay between the pump and probe pulses. A 10 ps pump-probe cross-correlation temporal width provides a useful compromise between time and frequency resolution (3 cm-1) . k( E) increases rapidly: from ˜2×10 10 to ⩾1.3×10 11 s-1 within 25 cm-1 of reaction threshold. In this regime, long-range interfragment interactions play an important role. A high level of theory will be needed to reconcile these results.
Lhotka, Christoph; Souchay, Jean; Baur, Oliver
2016-01-01
The aim of this study is first to determine the gravity field of the comet 67P Churyumov-Gerasimenko and second to derive the solar component of the precession rate and nutation coefficients of the spin axis of the comet nucleus, i.e. without the direct, usually larger, effect of outgassing. The gravity field, and related moments of inertia, are obtained from two polyhedra, that are provided by the OSIRIS and NAV-CAM experiments on Rosetta, and are based on the assumption of uniform density for the comet nucleus. We also calculate the forced precession rate as well as the nutation coefficients on the basis of Kinoshita's theory of rotation of the rigid Earth and adapted it to be able to indirectly include the effect of outgassing on the rotational parameters. The 2nd degree denormalized Stokes coefficients of comet 67P C-G turn out to be (bracketed numbers refer to second shape model) C20 = -6.74 [-7.93] * 10^-2, C22 = 2.60 [2.71] * 10^-2 consistent with normalized principal moments of inertia A/MR^2 = 0.13 [...
Gas entrainment rate coefficient of an ideal momentum atomizing liquid jet
Medrano, Fermín Franco; Velte, Clara Marika; Hodžić, Azur
2016-01-01
We propose a two-phase-fluid model for a turbulent full-cone high speed atomizing liquid jet that describes its dynamics in a simple but comprehensive manner with only the apex angle of the cone being a disposable parameter. The basic assumptions are that (i) the jet is statistically stationary and that (ii) it can be approximated by a mixture of a liquid and a gas with its phases in dynamic equilibrium. To derive the model, we impose conservation of the liquid volume and total momentum fluxes. Our model equation admits analytical solutions for the composite density and velocity of the two-phase fluid, both as functions of the distance from the nozzle, from which the dynamic pressure and gas the entrainment rate coefficient are calculated. Assuming a far-field approximation, we theoretically derive a constant gas entrainment rate coefficient solely in terms of the cone angle. Moreover, we carry out experiments for a single-phase turbulent air jet and show that the predictions of our model compare well with th...
Tono-oka, T; Kaneko, I
1993-05-01
The daily level of physical activity was estimated using the heart rate monitor, PE3000 (Polar Electro, Finland). The level was expressed with the coefficient of variation (CV) of heart rates recorded from waking time to dinner time. In the course of a day of intense physical activity, CV was confirmed to rise significantly. Then the CV was estimated and compared among 3 age classes, young (10-18 years), middle-aged (30-47 years), and elderly (62-76 years). The CVs of young people were significantly higher than those of middle-aged (P < 0.001) and elderly (P < 0.01), regardless of sex. However there was no significant sex difference in all age classes. These results suggest that the CV is an accurate index of daily physical activity. Thus clinicians can use the CV of heart rates to estimate the level of physical activity of individuals which closely relates to QOL.
Kramers-Moyal coefficients in the analysis and modeling of heart rate variability
Petelczyc, M.; Żebrowski, J. J.; Baranowski, R.
2009-09-01
Modeling of recorded time series may be used as a method of analysis for heart rate variability studies. In particular, the extraction of the first two Kramers-Moyal coefficients has been used in this context. Recently, the method was applied to a wide range of signal analysis: from financial data to physiological and biological time series. Modeling of the signal is important for the prediction and interpretation of the dynamics underlying the process. The method requires the determination of the Markov time. Obtaining the drift and diffusion term of the Kramers-Moyal expansion is crucial for the modeling of the original time series with the Langevin equation. Both Tabar [Comput. Sci. Eng. 8, 54 (2006)] and T. Kuusela [Phys. Rev. E 69, 031916 (2004)] suggested that these terms may be used to distinguish healthy subjects from those with heart failure. The research groups applied a somewhat different methodology and obtained substantially different ranges of the Markov time. We show that the two studies may be considered consistent with each other as Kuusela analyzed 24 h recordings while Tabar analyzed daytime and nighttime recordings, separately. However, both groups suggested using the Langevin equation for modeling of time series which requires the fluctuation force to be a Gaussian. We analyzed heart rate variability recordings for ten young male (age 26-4+3y ) healthy subjects. 24 h recordings were analyzed and 6-h-long daytime and nighttime fragments were selected. Similar properties of the data were observed in all recordings but all the nighttime data and seven of the ten 24 h series exhibited higher-order, non-negligible Kramers-Moyal coefficients. In such a case, the reconstruction of the time series using the Langevin equation is impossible. The non-negligible higher-order coefficients are due to autocorrelation in the data. This effect may be interpreted as a result of a physiological phenomenon (especially occurring for nighttime data): respiratory
Rampino, Sergio
2016-01-01
Thermal rate coefficients for the astrochemical reaction C + CH$^+$ $\\to$ C$_2^+$ + H were computed in the temperature range 20-300 K by using novel rate theory based on ring polymer molecular dynamics (RPMD) on a recently published bond-order based potential energy surface and compared with previous Langevin capture model (LCM) and quasi-classical trajectory (QCT) calculations. Results show that there is a significant discrepancy between the RPMD rate coefficients and the previous theoretical results which can lead to overestimation of the rate coefficients for the title reaction by several orders of magnitude at very low temperatures. We argue that this can be attributed to a very challenging energy profile along the reaction coordinate for the title reaction, not taken into account in extenso by either the LCM or QCT approximation. In the absence of any rigorous quantum mechanical or experimental results, the computed RPMD rate coefficients represent state-of-the-art estimates to be included in astrochemic...
Photoassociation inside an optical dipole trap: absolute rate coefficients and Franck-Condon factors
Wester, R; Mudrich, M; Staudt, M U; Lange, J; Vanhaecke, N; Dulieu, O; Weidemüller, M
2004-01-01
We present quantitative measurements of the photoassociation of cesium molecules inside a far-detuned optical dipole trap. A model of the trap depletion dynamics is derived which allows to extract absolute photoassociation rate coefficients for the initial single-photon photoassociation step from measured trap-loss spectra. The sensitivity of this approach is demonstrated by measuring the Franck-Condon modulation of the weak photoassociation transitions into the low vibrational levels of the outer well of the 0g- state that correlates to the 6s+6p3/2 asymptote. The measurements are compared to theoretical predictions. In a magneto-optical trap these transitions have previously only been observed indirectly through ionization of ground state molecules.
Cold collisions of SH- with He: Potential energy surface and rate coefficients
Bop, C. T.; Trabelsi, T.; Hammami, K.; Mogren Al Mogren, M.; Lique, F.; Hochlaf, M.
2017-09-01
Collisional energy transfer under cold conditions is of great importance from the fundamental and applicative point of view. Here, we investigate low temperature collisions of the SH- anion with He. We have generated a three-dimensional potential energy surface (PES) for the SH-(X1Σ+)-He(1S) van der Waals complex. The ab initio multi-dimensional interaction PES was computed using the explicitly correlated coupled cluster approach with simple, double, and perturbative triple excitation in conjunction with the augmented-correlation consistent-polarized valence triple zeta Gaussian basis set. The PES presents two minima located at linear geometries. Then, the PES was averaged over the ground vibrational wave function of the SH- molecule and the resulting two-dimensional PES was incorporated into exact quantum mechanical close coupling calculations to study the collisional excitation of SH- by He. We have computed inelastic cross sections among the 11 first rotational levels of SH- for energies up to 2500 cm-1. (De-)excitation rate coefficients were deduced for temperatures ranging from 1 to 300 K by thermally averaging the cross sections. We also performed calculations using the new PES for a fixed internuclear SH- distance. Both sets of results were found to be in reasonable agreement despite differences existing at low temperatures confirming that accurate predictions require the consideration of all internal degrees of freedom in the case of molecular hydrides. The rate coefficients presented here may be useful in interpreting future experimental work on the SH- negative ion colliding with He as those recently done for the OH--He collisional system as well as for possible astrophysical applications in case SH- would be detected in the interstellar medium.
Determination of collisional quenching rate coefficient of N2(A^3σu^+ )
Koizumi, Yuusuke; Suzuki, Susumu; Itoh, Haruo
2012-10-01
We have previously determined the collisional quenching rate coefficient of N2(A^3σu^+ ) by an air pollutant gas [1-4]. In this paper we report the collisional quenching rate coefficient k' of N2(A^3σu^+ ) by p-xylene (C8H10), which was determined to be (6.5±0.9)x10-9 cm^3/s. In addition, through repeated experiments it was found that by-products of p-xylene were deposited on the cathode, similarly to the cases of m-xylene and o-xylene previously reported [4], and then the current-voltage curves consistently shifed to a higher-E/p0 region. To clarify the reason for this behavior, we confirmed by Auger electron spectroscopy (AES) and Fourier transform infrared spectroscopy (FTIR) that these changes in the current-voltage curves were caused by the deposition of a thin film of by-product of decomposed xylene on the cathode surface. According to the results of AES, C atoms were detected in a sample exposed to an electrical discharge, and we confirmed that the deposit of C was thickest in the case of electrical discharge in p-xylene. According to the results of FTIR, it was found that CH2 and CH were obtained from the deposition of p-xylene. [4pt] [1] S. Suzuki, H. Itoh, H. Sekizawa and N. Ikuta, J. Phys. Soc. Jpn., 62, No.8, 2692-2697 (1993)[0pt] [2] S. Suzuki, H. Itoh, H. Sekizawa and N. Ikuta, Jpn. J. Appl. Phys., 36, 4744-4746 (1997)[0pt] [3] S. Suzuki, T. Suzuki and H. Itoh, Cont. of HAKONE X Saga, Japan, 132-135 (2006)[0pt] [4] S. Suzuki, H. Itoh, Proc. of 30th ICPIG (Belfast, UK), A1-12 (2011)
Rate Coefficients of the Reaction of OH with Allene and Propyne at High Temperatures
Es-Sebbar, Et Touhami
2016-09-28
Allene (H2C═C═CH2; a-C3H4) and propyne (CH3C≡CH; p-C3H4) are important species in various chemical environments. In combustion processes, the reactions of hydroxyl radicals with a-C3H4 and p-C3H4 are critical in the overall fuel oxidation system. In this work, rate coefficients of OH radicals with allene (OH + H2C═C═CH2 → products) and propyne (OH + CH3C≡CH → products) were measured behind reflected shock waves over the temperature range of 843–1352 K and pressures near 1.5 atm. Hydroxyl radicals were generated by rapid thermal decomposition of tert-butyl hydroperoxide ((CH3)3–CO–OH), and monitored by narrow line width laser absorption of the well-characterized R1(5) electronic transition of the OH A–X (0,0) electronic system near 306.7 nm. Results show that allene reacts faster with OH radicals than propyne over the temperature range of this study. Measured rate coefficients can be expressed in Arrhenius form as follows: kallene+OH(T) = 8.51(±0.03) × 10–22T3.05 exp(2215(±3)/T), T = 843–1352 K; kpropyne+OH(T) = 1.30(±0.07) × 10–21T3.01 exp(1140(±6)/T), T = 846–1335 K.
Laporta, V. [Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari, Italy and Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Celiberto, R. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica, Politecnico di Bari, Italy and Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari (Italy); Tennyson, J. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)
2014-12-09
Rate coefficients for dissociative electron attachment and electron-impact dissociation processes, involving vibrationally excited molecular oxygen, are presented. Analytical fits of the calculated numerical data, useful in the applications, are also provided.
Dependence of dose coefficients for {sup 239}Pu on transfer rates and absorption parameters
Suzuki, K.; Sekimoto, H. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo (Japan); Ishigure, N. [Division of Radiotoxicology and Protection, National Institute of Radiological Sciences, Chiba (Japan)
2000-05-01
As it is reported of the biokinetic models and parameter values of the International Commission on Radiological Protection (ICRP) for dose estimation have uncertainties owing to insufficiency of human data. For most radionuclides, the data underlying such models and parameters of ICRP usually depend on animal experiments. Moreover, these values or model parameter are also greatly different between mammalian species. Recently, various radiation protection organizations are considering the biokinetic uncertainties from standpoints of data's sources, quality and completeness. In practice, a sensitivity analysis of doses to parameters is significant for the purpose of risk assessment. In general, movement or material in the body is depicted as a system of first-order processes, and parameter values are expressed as transfer rates between compartments. In this study, we made a code to reproduce the ICRP's dose coefficients for {sup 239}Pu, which is one of the most important elements for occupational exposure and its effective dose is much concerned with its own distribution in the body for dominance of alpha-decay. By using this code, we modified each transfer rate in a factor of 2, 3 and 4 in order to evaluate the effects, and calculated the sensitivities of effective doses due to these changes. Additionally, we examined the effects of modification of absorption parameters f{sub r}, S{sub r} and S{sub s}, which represent the absorption of particles from respiratory tract into blood. Consequently, the transfer rates that give a large sensitivity were specified, and it was shown that changes of transfer rates and absorption parameters are not so influential on effective doses for {sup 239}Pu in many cases. (author)
Revised rate coefficients for H$_2$ and H$^-$ destruction by realistic stellar spectra
Agarwal, Bhaskar
2014-01-01
Understanding the processes that can destroy H$_2$ and H$^-$ species is quintessential in governing the formation of the first stars, black holes and galaxies. In this study we compute the reaction rate coefficients for H$_2$ photo--dissociation by Lyman--Werner photons ($11.2 - 13.6$ eV), and H$^-$ photo--detachment by 0.76 eV photons emanating from self-consistent stellar populations that we model using publicly available stellar synthesis codes. So far studies that include chemical networks for the formation of molecular hydrogen take these processes into account by assuming that the source spectra can be approximated by a power-law dependency or a black-body spectrum at 10$^4$ or $10^5$ K. We show that using spectra generated from realistic stellar population models can alter the reaction rates for photo-dissociation, $\\rm k_{\\rm{di}}$, and photo-detachment, $\\rm k_{\\rm{de}}$, significantly. In particular, $\\rm k_{\\rm{de}}$ can be up to $\\sim 2-4$ orders of magnitude lower in the case of realistic stellar...
Gómez-Carrasco, Susana [Facultad de Química, Unidad Asociada CSIC-USAL, Universidad de Salamanca, E-37008 Salamanca (Spain); Godard, Benjamin [LERMA, CNRS UMR 8112, Observatoire de Paris, F-92195 Meudon (France); Lique, François [LOMC-UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, F-76058 Le Havre (France); Bulut, Niyazi [Department of Physics, Firat University, 23169 Elazig (Turkey); Kłos, Jacek [Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742-2021 (United States); Roncero, Octavio [Instituto de Física Fundamental (IFF-CSIC), C.S.I.C., Serrano 123, E-28006 Madrid (Spain); Aguado, Alfredo [Facultad de Ciencias, Unidad Asociada de Química-Física Aplicada CSIC-UAM, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Aoiz, F. Javier; Castillo, Jesús F. [Departamento de Química Física I, Unidad Asociada de Química-Física CSIC-UCM, Facultad de Química, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Goicoechea, Javier R.; Etxaluze, Mireya; Cernicharo, José, E-mail: octavio.roncero@csic.es [Instituto de Ciencia de Materiales (ICMM-CSIC), C.S.I.C., Sor Juana Inés de la Cruz, 3, Cantoblanco, E-28049 Madrid (Spain)
2014-10-10
The rate constants required to model the OH{sup +} observations in different regions of the interstellar medium have been determined using state of the art quantum methods. First, state-to-state rate constants for the H{sub 2}(v = 0, J = 0, 1) + O{sup +}({sup 4} S) → H + OH{sup +}(X {sup 3}Σ{sup –}, v', N) reaction have been obtained using a quantum wave packet method. The calculations have been compared with time-independent results to assess the accuracy of reaction probabilities at collision energies of about 1 meV. The good agreement between the simulations and the existing experimental cross sections in the 0.01-1 eV energy range shows the quality of the results. The calculated state-to-state rate constants have been fitted to an analytical form. Second, the Einstein coefficients of OH{sup +} have been obtained for all astronomically significant rovibrational bands involving the X {sup 3}Σ{sup –} and/or A {sup 3}Π electronic states. For this purpose, the potential energy curves and electric dipole transition moments for seven electronic states of OH{sup +} are calculated with ab initio methods at the highest level, including spin-orbit terms, and the rovibrational levels have been calculated including the empirical spin-rotation and spin-spin terms. Third, the state-to-state rate constants for inelastic collisions between He and OH{sup +}(X {sup 3}Σ{sup –}) have been calculated using a time-independent close coupling method on a new potential energy surface. All these rates have been implemented in detailed chemical and radiative transfer models. Applications of these models to various astronomical sources show that inelastic collisions dominate the excitation of the rotational levels of OH{sup +}. In the models considered, the excitation resulting from the chemical formation of OH{sup +} increases the line fluxes by about 10% or less depending on the density of the gas.
Determination of the reaction rate coefficient of sulphide mine tailings deposited under water.
Awoh, Akué Sylvette; Mbonimpa, Mamert; Bussière, Bruno
2013-10-15
The efficiency of a water cover to limit dissolved oxygen (DO) availability to underlying acid-generating mine tailings can be assessed by calculating the DO flux at the tailings-water interface. Fick's equations, which are generally used to calculate this flux, require knowing the effective DO diffusion coefficient (Dw) and the reaction (consumption) rate coefficient (Kr) of the tailings, or the DO concentration profile. Whereas Dw can be accurately estimated, few studies have measured the parameter Kr for submerged sulphide tailings. The objective of this study was to determine Kr for underwater sulphide tailings in a laboratory experiment. Samples of sulphide mine tailings (an approximately 6 cm layer) were placed in a cell under a water cover (approximately 2 cm) maintained at constant DO concentration. Two tailings were studied: TA1 with high sulphide content (83% pyrite) and TA2 with low sulphide content (2.8% pyrite). DO concentration was measured with a microelectrode at various depths above and below the tailings-water interface at 1 mm intervals. Results indicate that steady-state condition was rapidly attained. As expected, a diffusive boundary layer (DBL) was observed in all cases. An iterative back-calculation process using the numerical code POLLUTEv6 and taking the DBL into account provided the Kr values used to match calculated and experimental concentration profiles. Kr obtained for tailings TA1 and TA2 was about 80 d(-1) and 6.5 d(-1), respectively. For comparison purposes, Kr obtained from cell tests on tailings TA1 was lower than Kr calculated from the sulphate production rate obtained from shake-flask tests. Steady-state DO flux at the water-tailings interface was then calculated with POLLUTEv6 using tailings characteristics Dw and Kr. For the tested conditions, DO flux ranged from 608 to 758 mg O2/m(2)/d for tailings TA1 and from 177 to 221 mg O2/m(2)/d for tailings TA2. The impact of placing a protective layer of inert material over
Shaw, A; Takács, I; Pagilla, K R; Murthy, S
2013-10-15
The Monod equation is often used to describe biological treatment processes and is the foundation for many activated sludge models. The Monod equation includes a "half-saturation coefficient" to describe the effect of substrate limitations on the process rate and it is customary to consider this parameter to be a constant for a given system. The purpose of this study was to develop a methodology, and its use to show that the half-saturation coefficient for denitrification is not constant but is in fact a function of the maximum denitrification rate. A 4-step procedure is developed to investigate the dependency of half-saturation coefficients on the maximum rate and two different models are used to describe this dependency: (a) an empirical linear model and (b) a deterministic model based on Fick's law of diffusion. Both models are proved better for describing denitrification kinetics than assuming a fixed K(NO3) at low nitrate concentrations. The empirical model is more utilitarian whereas the model based on Fick's law has a fundamental basis that enables the intrinsic K(NO3) to be estimated. In this study data was analyzed from 56 denitrification rate tests and it was found that the extant K(NO3) varied between 0.07 mgN/L and 1.47 mgN/L (5th and 95th percentile respectively) with an average of 0.47 mgN/L. In contrast to this, the intrinsic K(NO3) estimated for the diffusion model was 0.01 mgN/L which indicates that the extant K(NO3) is greatly influenced by, and mostly describes, diffusion limitations.
Phase retrieval of reflection and transmission coefficients from Kramers-Kronig relations
Gralak, Boris; Zerrad, Myriam; Amra, Claude
2014-01-01
Analytic and passivity properties of reflection and transmission coefficients of thin-film multilayered stacks are investigated. Using a rigorous formalism based on the inverse Helmholtz operator, properties associated to causality principle and passivity are established when both temporal frequency and spatial wavevector are continued in the complex plane. This result extends the range of situations where the Kramers-Kronig relations can be used to deduce the phase from the intensity. In particular, it is rigorously shown that Kramers-Kronig relations for reflection and transmission coefficients remain valid at a fixed angle of incidence. Possibilities to exploit the new relationships are discussed.
Phase retrieval of reflection and transmission coefficients from Kramers-Kronig relations.
Gralak, Boris; Lequime, Michel; Zerrad, Myriam; Amra, Claude
2015-03-01
Analytic and passivity properties of reflection and transmission coefficients of thin-film multilayered stacks are investigated. Using a rigorous formalism based on the inverse Helmholtz operator, properties associated with the causality principle and passivity are established when both the temporal frequency and spatial wave vector are continued in the complex plane. This result extends the range of situations where the Kramers-Kronig relations can be used to deduce the phase from the intensity. In particular, it is rigorously shown that the Kramers-Kronig relations for reflection and transmission coefficients remain valid for all fixed angles of incidence. Possibilities for exploiting the new relationships are discussed and numerically tested.
Yamaikina, Irene V.; Furmanchuk, Dmitryi A.
1998-06-01
Method of erythrocyte sedimentation rate (ESR) measurement is non-specific one. The ESR are tightly correlated to increase or decrease of aggregation coefficient (N). The variations of N could happen due to two main reasons: either changes in concentration of plasma proteins (first of all of fibrinogen) or changes of erythrocyte membrane characteristics (surface charge, transmembrane potential). The cross-method of ESR analysis has been proposed, using blood samples from patient and healthy donor of the same ABO blood groups and Rh-factors. The hematocrit (Ho)-ESR dependencies were measured in four variants: (1) patient's erythrocytes in patient's plasma; (2) patient's erythrocytes in donor's plasma; (3) donor's erythrocytes in donor's plasma; (4) donor's erythrocytes in patient's plasma. On presenting the ESR data for more than 100 patients with different bone marrow disorders after chemotherapy in the coordinates Ho-ESR three conventional zones could be marked out: high-ESR zone, medium zone and zone of low level of Ho. Proposed cross-method allows to estimate which of the two aforementioned reasons results in ESR variation. Some patients revealed not only changed fibrinogen level but additional changes in membrane affinity to fibrinogen. The modificated ESR cross-method opens us some new capacities in medical diagnostics.
Methods of modelling relative growth rate
Arne Pommerening; Anders Muszta
2015-01-01
Background:Analysing and modelling plant growth is an important interdisciplinary field of plant science. The use of relative growth rates, involving the analysis of plant growth relative to plant size, has more or less independently emerged in different research groups and at different times and has provided powerful tools for assessing the growth performance and growth efficiency of plants and plant populations. In this paper, we explore how these isolated methods can be combined to form a consistent methodology for modelling relative growth rates. Methods:We review and combine existing methods of analysing and modelling relative growth rates and apply a combination of methods to Sitka spruce (Picea sitchensis (Bong.) Carr.) stem-analysis data from North Wales (UK) and British Douglas fir (Pseudotsuga menziesi (Mirb.) Franco) yield table data. Results:The results indicate that, by combining the approaches of different plant-growth analysis laboratories and using them simultaneously, we can advance and standardise the concept of relative plant growth. Particularly the growth multiplier plays an important role in modelling relative growth rates. Another useful technique has been the recent introduction of size-standardised relative growth rates. Conclusions:Modelling relative growth rates mainly serves two purposes, 1) an improved analysis of growth performance and efficiency and 2) the prediction of future or past growth rates. This makes the concept of relative growth ideally suited to growth reconstruction as required in dendrochronology, climate change and forest decline research and for interdisciplinary research projects beyond the realm of plant science.
Methods of modelling relative growth rate
Arne Pommerening
2015-03-01
Full Text Available Background Analysing and modelling plant growth is an important interdisciplinary field of plant science. The use of relative growth rates, involving the analysis of plant growth relative to plant size, has more or less independently emerged in different research groups and at different times and has provided powerful tools for assessing the growth performance and growth efficiency of plants and plant populations. In this paper, we explore how these isolated methods can be combined to form a consistent methodology for modelling relative growth rates. Methods We review and combine existing methods of analysing and modelling relative growth rates and apply a combination of methods to Sitka spruce (Picea sitchensis (Bong. Carr. stem-analysis data from North Wales (UK and British Douglas fir (Pseudotsuga menziesii (Mirb. Franco yield table data. Results The results indicate that, by combining the approaches of different plant-growth analysis laboratories and using them simultaneously, we can advance and standardise the concept of relative plant growth. Particularly the growth multiplier plays an important role in modelling relative growth rates. Another useful technique has been the recent introduction of size-standardised relative growth rates. Conclusions Modelling relative growth rates mainly serves two purposes, 1 an improved analysis of growth performance and efficiency and 2 the prediction of future or past growth rates. This makes the concept of relative growth ideally suited to growth reconstruction as required in dendrochronology, climate change and forest decline research and for interdisciplinary research projects beyond the realm of plant science.
Lingaswamy, A. P.; Arafath, S. Md; Balakrishnaiah, G.; Rama Gopal, K.; Siva Kumar Reddy, N.; Raja Obul Reddy, K.; Reddy, R. R.; Chakradhar Rao, T.
2017-06-01
Continuous ground-based measurements of CO, SO2 and NO2 were carried out in a semi-arid rural area, Anantapur [14.62 0N, 77.65 0E], Southern India, for the period January 2012-December 2012. The maximum CO concentration was observed in winter (310 ± 17 ppbv) followed by summer (180 ± 21 ppbv) and post monsoon (174 ± 20 ppbv), while the minimum in monsoon (72 ± 9 ppbv). Seasonal mean NO2/NOx ratios for monsoon, post monsoon, winter and summer were about 0.88, 0.91, 0.76 and 0.80 respectively, indicating a higher conversion of NO to NO2 over the measurement site. Monthly mean low SO2 mixing ratio was found (0.46 ± 0.02 ppbv) in monsoon and high (2.42 ± 0.21 ppbv) in winter. Keeping the emissions aside, the levels of CO, SO2 and NO2 were influenced by meteorology, urban effects and trans-boundary transport in the lower troposphere. Atmospheric boundary layer (ABL) had the good correlation coefficient (R = 0.76) with solar radiation during daytime, while it was mainly correlated with wind speed during night time (R = 0.42). Diurnal trend of atmospheric visibility was found to be maximum during noon times at around (14:00-16:00 h) about 76 k.m. and minimum during morning periods (06:00-08:00 h) about 45 k.m. A strong positive correlation was observed between BC and CO (R = 0.71) with an average slope, suggesting common or proximate sources likely to be traffic emissions contribution for the production of BC and CO. The SO2/NOx and CO/NOx study were strongly suggested that mobile sources were larger contributors over the site and the evidence of transport of emissions from other surrounding regions. Tropospheric Ultraviolet Visible (TUV) radiative transfer model was used to calculate the Photolysis rate coefficients (J(O3), J(NO2)). Chemical box model (NCAR-MM) was used to simulate diurnal variation of CO and the results were reported.
The relation between Pearson’s correlation coefficient r and Salton’s cosine measure
Egghe, L.; Leydesdorff, L.
2009-01-01
The relation between Pearson's correlation coefficient and Salton's cosine measure is revealed based on the different possible values of the division of the L1-norm and the L2-norm of a vector. These different values yield a sheaf of increasingly straight lines which together form a cloud of points,
The relation between Pearson’s correlation coefficient r and Salton’s cosine measure
Egghe, L.; Leydesdorff, L.
2009-01-01
The relation between Pearson's correlation coefficient and Salton's cosine measure is revealed based on the different possible values of the division of the L1-norm and the L2-norm of a vector. These different values yield a sheaf of increasingly straight lines which together form a cloud of points,
ZHANG Xiangmu; MA Wenjuan; CUI Shuwen; WANG Lihua
2006-01-01
Based on a single ion model, Hamiltonian of the simplest form about magnetocrystalline anisotropy for Tb3+ ion was solved by using the numerical method. The relation between the stabilization energy, crystal field coefficient B20 and the magnetic exchange interaction was studied as temperature approaches to 0K. The results show that the stabilization energy contributed by Tb3+ is linear with crystal field coefficient B20 approximately, but it is insensitive to the change of magnetic exchange interaction for the strong magnetic substancessuch as TbCo5, Tb2Co17 and Tb2Fe14B compounds.
J. B. Burkholder
2011-06-01
Full Text Available Rate coefficients, k, for the gas-phase reaction of CH3COCHO (methylglyoxal with the OH and NO3 radicals and (CHO2 (glyoxal with the NO3 radical are reported. Rate coefficients for the OH + CH3COCHO (k1 reaction were measured under pseudo-first-order conditions in OH as a function of temperature (211–373 K and pressure (100–220 Torr, He and N2 bath gases using pulsed laser photolysis to produce OH radicals and laser induced fluorescence to measure its temporal profile. k1 was found to be independent of the bath gas pressure with k1(295 K = (1.29 ± 0.13 × 10−11 cm3 molecule−1 s−1 and a temperature dependence that is well represented by the Arrhenius expression k1(T = (1.74 ± 0.20 × 10−12 exp[(590 ± 40/T] cm3 molecule−1 s−1 where the uncertainties are 2σ and include estimated systematic errors. Rate coefficients for the NO3+ (CHO2 (k3 and NO3+ CH3COCHO (k4 reactions were measured using a relative rate technique to be k3(296 K = (3.7 ± 1.0 × 10−16 cm3 molecule−1 s−1 and k4(296 K = (4.1 ± 1.2 × 10−16 cm3 molecule−1 s−1. k3(T was also measured using an absolute rate coefficient method under pseudo-first-order conditions at 296 and 353 K to be (4.2 ± 0.8 × 10−16 and (7.9 ± 3.6 × 10−16 cm3 molecule−1 s−1, respectively, in agreement with the relative rate result obtained at room temperature. The atmospheric implications of the OH and NO3 reaction rate coefficients measured in this work are discussed.
J. B. Burkholder
2011-11-01
Full Text Available Rate coefficients, k, for the gas-phase reaction of CH3COCHO (methylglyoxal with the OH and NO3 radicals and (CHO2 (glyoxal with the NO3 radical are reported. Rate coefficients for the OH + CH3COCHO (k1 reaction were measured under pseudo-first-order conditions in OH as a function of temperature (211–373 K and pressure (100–220 Torr, He and N2 bath gases using pulsed laser photolysis to produce OH radicals and laser induced fluorescence to measure its temporal profile. k1 was found to be independent of the bath gas pressure with k1(295 K = (1.29 ± 0.13 × 10−11 cm3 molecule−1 s−1 and a temperature dependence that is well represented by the Arrhenius expression k1(T = (1.74 ± 0.20 × 10−12 exp[(590 ± 40/T] cm3 molecule−1 s−1 where the uncertainties are 2σ and include estimated systematic errors. Rate coefficients for the NO3 + (CHO2 (k3 and NO3 + CH3COCHO (k4 reactions were measured using a relative rate technique to be k3(296 K = (4.0 ± 1.0 × 10−16 cm3 molecule−1 s−1 and k4(296 K = (5.1 ± 2.1 × 10−16 cm3 molecule−1 s−1. k3(T was also measured using an absolute rate coefficient method under pseudo-first-order conditions at 296 and 353 K to be (4.2 ± 0.8 × 10−16 and (7.9 ± 3.6 × 10−16 cm3 molecule−1 s−1, respectively, in agreement with the relative rate result obtained at room temperature. The atmospheric implications of the OH and NO3 reaction rate coefficients measured in this work are discussed.
A new formulation of the understeer coefficient to relate yaw torque and vehicle handling
Bucchi, F.; Frendo, F.
2016-06-01
The handling behaviour of vehicles is an important property for its relation to performance and safety. In 1970s, Pacejka did the groundwork for an objective analysis introducing the handling diagram and the understeer coefficient. In more recent years, the understeer concept is still mentioned but the handling is actively managed by direct yaw control (DYC). In this paper an accurate analysis of the vehicle handling is carried out, considering also the effect of drive forces. This analysis brings to a new formulation of the understeer coefficient, which is almost equivalent to the classical one, but it can be obtained by quasi-steady-state manoeuvres. In addition, it relates the vehicle yaw torque to the understeer coefficient, filling up the gap between the classical handling approach and DYC. A multibody model of a Formula SAE car is then used to perform quasi-steady-state simulations in order to verify the effectiveness of the new formulation. Some vehicle set-ups and wheel drive arrangements are simulated and the results are discussed. In particular, the handling behaviours of the rear wheel drive (RWD) and the front wheel drive (FWD) architectures are compared, finding an apparently surprising result: for the analysed vehicle the FWD is less understeering than for RWD. The relation between the yaw torque and the understeer coefficient allows to understand this behaviour and opens-up the possibility for different yaw control strategies.
The degree-related clustering coefficient and its application to link prediction
Liu, Yangyang; Zhao, Chengli; Wang, Xiaojie; Huang, Qiangjuan; Zhang, Xue; Yi, Dongyun
2016-07-01
Link prediction plays a significant role in explaining the evolution of networks. However it is still a challenging problem that has been addressed only with topological information in recent years. Based on the belief that network nodes with a great number of common neighbors are more likely to be connected, many similarity indices have achieved considerable accuracy and efficiency. Motivated by the natural assumption that the effect of missing links on the estimation of a node's clustering ability could be related to node degree, in this paper, we propose a degree-related clustering coefficient index to quantify the clustering ability of nodes. Unlike the classical clustering coefficient, our new coefficient is highly robust when the observed bias of links is considered. Furthermore, we propose a degree-related clustering ability path (DCP) index, which applies the proposed coefficient to the link prediction problem. Experiments on 12 real-world networks show that our proposed method is highly accurate and robust compared with four common-neighbor-based similarity indices (Common Neighbors(CN), Adamic-Adar(AA), Resource Allocation(RA), and Preferential Attachment(PA)), and the recently introduced clustering ability (CA) index.
Relations among Dirichlet series whose coefficients are class numbers of binary cubic forms II
Ohno, Yasuo
2011-01-01
As a continuation of the authors and Wakatsuki's previous paper [5], we study relations among Dirichlet series whose coefficients are class numbers of binary cubic forms. We show that for any integral models of the space of binary cubic forms, the associated Dirichlet series satisfies a simple explicit relation to that of the dual other than the usual functional equation. As an application, we write the functional equations of these Dirichlet series in self dual forms.
Spruck, K; Krantz, C; Novotný, O; Becker, A; Bernhardt, D; Grieser, M; Hahn, M; Repnow, R; Savin, D W; Wolf, A; Müller, A; Schippers, S
2014-01-01
We present new experimentally measured and theoretically calculated rate coefficients for the electron-ion recombination of W$^{18+}$([Kr] $4d^{10}$ $4f^{10}$) forming W$^{17+}$. At low electron-ion collision energies, the merged-beam rate coefficient is dominated by strong, mutually overlapping, recombination resonances. In the temperature range where the fractional abundance of W$^{18+}$ is expected to peak in a fusion plasma, the experimentally derived Maxwellian recombination rate coefficient is 5 to 10 times larger than that which is currently recommended for plasma modeling. The complexity of the atomic structure of the open-$4f$-system under study makes the theoretical calculations extremely demanding. Nevertheless, the results of new Breit-Wigner partitioned dielectronic recombination calculations agree reasonably well with the experimental findings. This also gives confidence in the ability of the theory to generate sufficiently accurate atomic data for the plasma modeling of other complex ions.
Ballesteros, Bernabé; Ceacero-Vega, Antonio A; Jiménez, Elena; Albaladejo, José
2015-04-01
As the result of biogenic and anthropogenic activities, large quantities of chemical compounds are emitted into the troposphere. Alkanes, in general, and cycloalkanes are an important chemical class of hydrocarbons found in diesel, jet and gasoline, vehicle exhaust emissions, and ambient air in urban areas. In general, the primary atmospheric fate of organic compounds in the gas phase is the reaction with hydroxyl radicals (OH). The oxidation by Cl atoms has gained importance in the study of atmospheric reactions because they may exert some influence in the boundary layer, particularly in marine and coastal environments, and in the Arctic troposphere. The aim of this paper is to study of the atmospheric reactivity of methylcylohexanes with Cl atoms and OH radicals under atmospheric conditions (in air at room temperature and pressure). Relative kinetic techniques have been used to determine the rate coefficients for the reaction of Cl atoms and OH radicals with methylcyclohexane, cis-1,4-dimethylcyclohexane, trans-1,4-dimethylcyclohexane, and 1,3,5-trimethylcyclohexane at 298 ± 2 K and 720 ± 5 Torr of air by Fourier transform infrared) spectroscopy and gas chromatography-mass spectrometry (GC-MS) in two atmospheric simulation chambers. The products formed in the reaction under atmospheric conditions were investigated using a 200-L Teflon bag and employing the technique of solid-phase microextraction coupled to a GC-MS. The rate coefficients obtained for the reaction of Cl atoms with the studied compounds are the following ones (in units of 10(-10) cm(3) molecule(-1) s(-1)): (3.11 ± 0.16), (2.89 ± 0.16), (2.89 ± 0.26), and (2.61 ± 0.42), respectively. For the reactions with OH radicals the determined rate coefficients are (in units of 10(-11) cm(3) molecule(-1) s(-1)): (1.18 ± 0.12), (1.49 ± 0.16), (1.41 ± 0.15), and (1.77 ± 0.23), respectively. The reported error is twice the standard deviation. A detailed
Coefficient of variation as a measure of relative wetness of different stations in India
Mishra, K. K.
1991-12-01
Assessment of relative wetness in different months is a prerequisite for proper planning and utilization of available water resources of an area. Using monthly rainfall data of four different stations in India, the present paper shows that C v, the coefficient of variation, can be used as a measure of relative wetness/dryness. It was further observed that the amount of rainfall for a given probability level can be quickly computed in terms of percentile values. C v is exponentially related to P60, the sixtieth percentile of the amount of rainfall.
Preliminary Report on Use of Self-Ratings to Provide J-Coefficient Data.
Primoff, Ernest S.
This report shows how Beta weights for the J-Coefficient may be easily developed without a formal validity study, and indicates how indications of ability other than tests can be used to measure the same abilities that are measured by tests. See also TM 001 163-64,166 for further information on job elements (J-Scale) procedures. (Author/DLG)
Multiple analogues of binomial coefficients and related families of special numbers
Coskun, Hasan
2010-01-01
We construct multiple $qt$-binomial coefficients and related multiple analogues of several celebrated families of special numbers in this paper. These multidimensional generalizations include the first and the second kind of $qt$-Stirling numbers, $qt$-Bell numbers, $qt$-Bernoulli numbers, $qt$-Catalan numbers and the $qt$--Fibonacci numbers. In the course of developing main properties of these extensions, we prove results that are significant in their own rights such as certain probability m...
LABORATORY STUDY OF RATE COEFFICIENTS FOR H{sub 2}O:He INELASTIC COLLISIONS BETWEEN 20 AND 120 K
Tejeda, G.; Moreno, E.; Fernández, J. M.; Montero, S. [Laboratory of Molecular Fluid Dynamics, Instituto de Estructura de la Materia, CSIC Serrano 121, E-28006 Madrid (Spain); Carmona-Novillo, E.; Hernández, M. I., E-mail: emsalvador@iem.cfmac.csic.es [Instituto de Física Fundamental, CSIC Serrano 123, E-28006 Madrid (Spain)
2015-01-01
State-to-state rate coefficients for ortho-H{sub 2}O:He and para-H{sub 2}O:He inelastic collisions in the 20-120 K thermal range are investigated by means of an improved experimental procedure. This procedure is based on the use of a kinetic master equation (MEQ) which describes the evolution of populations of H{sub 2}O rotational levels along a supersonic jet of H{sub 2}O highly diluted in helium. The MEQ is expressed in terms of experimental observables and rate coefficients for H{sub 2}O:He inelastic collisions. The primary experimental observables are the local number density and the populations of the rotational energy levels of H{sub 2}O, quantities which are determined along the jet with unprecedented accuracy by means of Raman spectroscopy with high space resolution. Sets of rate coefficients from the literature and from present close-coupling calculations using two different potential energy surfaces (PESs) have been tested against the experiment. The Green et al. rate coefficients are up to 50% too low compared to the experiment, while most rates calculated here from the Hodges et al. PES and the Patkowski et al. PES are much closer to the experimental values. Experimental rates with an estimated accuracy on the order of 10% have been obtained for ortho-H{sub 2}O:He and para-H{sub 2}O:He inelastic collisions between 20 and 120 K by scaling and averaging the theoretical rates to the experiment.
Chen, Yao; Ho, Daniel W C; Lü, Jinhu; Lin, Zongli
2016-01-01
Multiagent systems (MASs) are ubiquitous in our real world. There is an increasing attention focusing on the consensus (or synchronization) problem of MASs over the past decade. Although there are numerous results reported on the convergence of a discrete-time MAS based on the infinite products of matrices, few results are on the convergence rate. Because of the switching topology, the traditional eigenvalue analysis and the Lyapunov function methods are both invalid for the convergence rate analysis of an MAS with a switching topology. Therefore, the estimation of the convergence rate for a discrete-time MAS with time-varying delays remains a difficult problem. To overcome the essential difficulty of switching topology, this paper aims at developing a contractive-set approach to analyze the convergence rate of a discrete-time MAS in the presence of time-varying delays and generalized coupling coefficients. Using the proposed approach, we obtain an upper bound of the convergence rate under the condition of joint connectivity. In particular, the proposed method neither requires the nonnegative property of the coupling coefficients nor the basic assumption of a uniform lower bound for all positive coupling coefficients, which have been widely applied in the existing works on this topic. As an application of the main results, we will show that the classical Vicsek model with time delays can realize synchronization if the initial topology is connected.
林国星; 陈金灿
2001-01-01
The cyclic model of a class of chemical pumps is established.The effect of the irreversibility of mass transfer on the cyclic performance is taken into account,and the relationship between the optimal coefficient of performance and the rate of energy pumping is derived.Moreover,other optimal performances of the cycle are discussed.The results obtained here can provide some new theoretical guidelines for the optimal design of a class of apparatus such as electrochemical,photochemical,and mass exchangers and solid state devices.%建立了一类化学泵循环模型,考虑质量传递不可逆性对循环性能的影响,导出循环的泵能率与性能系数间的优化关系.在此基础上进一步讨论了循环的其它优化特性.所得结论可为电化学、光化学、质量交换器及固态设备等的优化设计提供新的理论指导.
Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault
2008-01-01
Correlation dimension as a tool to describe machinery condition is introduced.Vibration signals of the fan under different working conditions are analyzed using a threshold filtering algorithm based on the region relativity of the wavelet coefficients for reducing noise.The result shows that the characteristics of the signal could be preserved completely.The correlation dimension is able to identify conditions of the fan with faults compared with the normal condition,thereby providing an effective technology for condition monitoring and fault diagnosis of mechanical equipment.
Morawetz, K
1999-07-01
Within the frame of kinetic theory a response function is derived for finite Fermi systems which includes dissipation in relaxation time approximation and a contribution from additional chaotic processes characterized by the largest Lyapunov exponent. A generalized local density approximation is presented including the effect of many particle relaxation and the additional chaotic scattering. For small Lyapunov exponents relative to the product of wave vector and Fermi time. Therefore the transport coefficients can be connected with the largest positive Lyapunov exponent in the same way as known the transport theory in relaxation time approximation. (author)
Buchachenko, A. A.; Kroupnov, A. A.; Kovalev, V. L.
2015-08-01
Elementary stage rate coefficients of the full system of kinetic equations describing heterogeneous catalytic recombination of the dissociated air on the surfaces of thermal protective ceramic coatings of β-cristobalite and α-Al2O3 are determined using the quantum-mechanical calculations within the framework of cluster models and literature data. Both the impact and associative recombination processes of adsorbed oxygen and nitrogen atoms are taken into account.
Yan, Hong-mei; Chen, Xiao-yun; Xia, Hai-jian; Liu, Dan; Jia, Xiao-bin; Zhang, Zhen-hai
2015-02-01
The difference between three representative components of total salvianolic acids in pharmacodynamic activity were compared by three different pharmacological experiments: HUVECs oxidative damage experiment, 4 items of blood coagulation in vitro experiment in rabbits and experimental myocardial ischemia in rats. And the effects of contribution rate of each component were calculated by multi index comprehensive evaluation method based on CRITIC weights. The contribution rates of salvianolic acid B, rosmarinic acid and Danshensu were 28.85%, 30.11%, 41.04%. Apparent oil/water partition coefficient of each representative components of total salvianolic acids in n-octyl alcohol-buffer was tested and the total salvianolic acid components were characterized based on a combination of the approach of self-defined weighting coefficient with effects of contribution rate. Apparent oil/water partition coefficient of total salvianolic acids was 0.32, 1.06, 0.89, 0.98, 0.90, 0.13, 0.02, 0.20, 0.56 when in octanol-water/pH 1.2 dilute hydrochloric acid solution/ pH 2.0, 2.5, 5.0, 5.8, 6.8, 7.4, 7.8 phosphate buffer solution. It provides a certain reference for the characterization of components.
Yao, Kangning; Chi, Yong; Wang, Fei; Yan, Jianhua; Ni, Mingjiang; Cen, Kefa
2016-01-01
A commonly used aeration device at present has the disadvantages of low mass transfer rate because the generated bubbles are several millimeters in diameter which are much bigger than microbubbles. Therefore, the effect of a microbubble on gas-liquid mass transfer and wastewater treatment process was investigated. To evaluate the effect of each bubble type, the volumetric mass transfer coefficients for microbubbles and conventional bubbles were determined. The volumetric mass transfer coefficient was 0.02905 s(-1) and 0.02191 s(-1) at a gas flow rate of 0.67 L min(-1) in tap water for microbubbles and conventional bubbles, respectively. The degradation rate of simulated municipal wastewater was also investigated, using aerobic activated sludge and ozone. Compared with the conventional bubble generator, the chemical oxygen demand (COD) removal rate was 2.04, 5.9, 3.26 times higher than those of the conventional bubble contactor at the same initial COD concentration of COD 200 mg L(-1), 400 mg L(-1), and 600 mg L(-1), while aerobic activated sludge was used. For the ozonation process, the rate of COD removal using microbubble generator was 2.38, 2.51, 2.89 times of those of the conventional bubble generator. Based on the results, the effect of initial COD concentration on the specific COD degradation rate were discussed in different systems. Thus, the results revealed that microbubbles could enhance mass transfer in wastewater treatment and be an effective method to improve the degradation of wastewater.
Rate coefficients for low-energy electron dissociative attachment to molecular hydrogen
Horacek, J.; Houfek, K.; Cizek, M. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Murakami, I.; Kato, T. [National Inst. for Fusion Science, Toki, Gifu (Japan)
2003-02-01
Calculation of rate constants for dissociative electron attachment to molecular hydrogen is reported. The calculation is based on an improved nonlocal resonance model of Cizek, Horacek and Domcke which takes fully into account the nonlocality of the resonance dynamics and uses potentials with correct asymptotic forms. The rate constants are calculated for all quantum numbers v and J of the target molecules and for electron temperature in the range 0-30000 K. (author)
Rate coefficients for low-energy electron dissociative attachment to molecular hydrogen
Horacek, J.; Houfek, K.; Cizek, M. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Murakami, I.; Kato, T. [National Inst. for Fusion Science, Toki, Gifu (Japan)
2003-02-01
Calculation of rate constants for dissociative electron attachment to molecular hydrogen is reported. The calculation is based on an improved nonlocal resonance model of Cizek, Horacek and Domcke which takes fully into account the nonlocality of the resonance dynamics and uses potentials with correct asymptotic forms. The rate constants are calculated for all quantum numbers v and J of the target molecules and for electron temperature in the range 0-30000 K. (author)
Measurements of Drag Coefficients and Rotation Rates of Free-Falling Helixes
Al-Omari, Abdulrhaman A.
2016-05-01
The motion of bacteria in the environment is relevant to several fields. At very small scales and with simple helical shapes, we are able to describe experimentally and mathematically the motion of solid spirals falling freely within a liquid pool. Using these shapes we intend to mimic the motion of bacteria called Spirochetes. We seek to experimentally investigate the linear and the rotational motion of such shapes. A better understanding of the dynamics of this process will be practical not only on engineering and physics, but the bioscience and environmental as well. In the following pages, we explore the role of the shape on the motion of passive solid helixes in different liquids. We fabricate three solid helical shapes and drop them under gravity in water, glycerol and a mixture of 30% glycerol in water. That generated rotation due to helical angle in water. However, we observe the rotation disappear in glycerol. The movement of the solid helical shapes is imaged using a high-speed video camera. Then, the images are analyzed using the supplied software and a computer. Using these simultaneous measurements, we examine the terminal velocity of solid helical shapes. Using this information we computed the drag coefficient and the drag force. We obtain the helical angular velocity and the torque applied to the solid. The results of this study will allow us to more accurately predict the motion of solid helical shape. This analysis will also shed light onto biological questions of bacteria movement.
Einstein-Kubo-Helfand and McQuarrie relations for transport coefficients
Erpenbeck, Jerome J.
1995-05-01
The formal equivalence of the Green-Kubo and Einstein-Kubo-Helfand (EKH) expressions for transport coefficients is well known. For finite systems subject to periodic boundary conditions, the EKH relations are ambiguous as to whether the toroidal or infinite-checkerboard descriptions should be used for the coordinates. We first describe qualitatively the application of both descriptions to the calculation of the self-diffusion and shear viscosity coefficients. We then show that the calculation of the self-diffusion coefficient using the infinite-checkerboard EKH relation is equivalent to the Green-Kubo calculation, while the toroidal calculation is not. For shear viscosity, we find that neither the toroidal nor infinite-checkerboard calculation from the EKH relation is equivalent to the Green-Kubo calculation, even though the formal theory presumably suggests that each is correct when the long-time limit is taken after the limit of large-system size. An alternative relation for the shear viscosity of finite periodic systems is derived from the Green-Kubo formula, consisting of the infinite-checkerboard expression plus correction terms having a fundamentally more complicated dependence on the coordinates and momenta. A simple qualitative analysis of the system-size dependence of the difference between the time-dependent Green-Kubo and the infinite-checkerboard EKH shear viscosities [η(tN) and η(C)E(tN), respectively] shows this difference to be of O(N1/3) (N being the number of particles) at early times. Monte Carlo molecular dynamics calculations of η(C)E(tN) for an equimolar binary mixture of hard spheres (diameter ratio of 0.4 and mass ratio of 0.03) confirm these large differences at a few mean free times, but suggest a long-time plateau value having the magnitude of the Green-Kubo result, but the values at 70 mean free times do not approach η(tN) with increasing N. Finally, we consider the one-particle, EKH-like, McQuarrie expression for shear viscosity
Muir, B. R.; McEwen, M. R.; Rogers, D. W. O.
2014-10-01
A method is presented to obtain ion chamber calibration coefficients relative to secondary standard reference chambers in electron beams using depth-ionization measurements. Results are obtained as a function of depth and average electron energy at depth in 4, 8, 12 and 18 MeV electron beams from the NRC Elekta Precise linac. The PTW Roos, Scanditronix NACP-02, PTW Advanced Markus and NE 2571 ion chambers are investigated. The challenges and limitations of the method are discussed. The proposed method produces useful data at shallow depths. At depths past the reference depth, small shifts in positioning or drifts in the incident beam energy affect the results, thereby providing a built-in test of incident electron energy drifts and/or chamber set-up. Polarity corrections for ion chambers as a function of average electron energy at depth agree with literature data. The proposed method produces results consistent with those obtained using the conventional calibration procedure while gaining much more information about the behavior of the ion chamber with similar data acquisition time. Measurement uncertainties in calibration coefficients obtained with this method are estimated to be less than 0.5%. These results open up the possibility of using depth-ionization measurements to yield chamber ratios which may be suitable for primary standards-level dissemination.
Xu, Jing; Zhang, Jianshun S; Liu, Xiaoyu; Gao, Zhi
2012-06-01
The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50%, and 70% RH). The "green" materials contained recycled materials and were friendly to environment. A dynamic dual-chamber test method was used. Results showed that a higher relative humidity led to a larger effective diffusion coefficient for two kinds of wallboards and carpet. The carpet was also found to be very permeable resulting in an effective diffusion coefficient at the same order of magnitude with the formaldehyde diffusion coefficient in air. The partition coefficient (K(ma)) of formaldehyde in conventional wallboard was 1.52 times larger at 50% RH than at 20% RH, whereas it decreased slightly from 50% to 70% RH, presumably due to the combined effects of water solubility of formaldehyde and micro-pore blocking by condensed moisture at the high RH level. The partition coefficient of formaldehyde increased slightly with the increase of relative humidity in "green" wallboard and "green" carpet. At the same relative humidity level, the "green" wallboard had larger partition coefficient and effective diffusion coefficient than the conventional wallboard, presumably due to the micro-pore structure differences between the two materials. The data generated could be used to assess the sorption effects of formaldehyde on building materials and to evaluate its impact on the formaldehyde concentration in buildings.
G. Dall'Olmo
2011-11-01
Full Text Available The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (c_{p} measured at multiple wavelengths. The method is based on fitting observations with a size-structured population model coupled to an optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in c_{p}. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the diel variability in c_{p}. Application of this method to spectral c_{p} measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in c_{p} can be ascribed to a synchronized population of cells with an equivalent spherical diameter around 4.6±1.5 μm. The inferred carbon biomass of these cells was about 5.2–6.0 mg m^{−3} and accounted for approximately 10% of the total particulate organic carbon. If successfully validated, this method may improve our in situ estimates of primary productivity.
G. Dall'Olmo
2011-03-01
Full Text Available The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (c_{p} measured at multiple wavelengths. The method is based on fitting observations with a size-structured population and optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in c_{p}. Results show that the information related to size and contained in the spectral data can be exploited to independently estimate growth and loss rates during the day and night. In addition, the model can characterize the population of particles affecting the c_{p} diel variability. Application of this method to spectral c_{p} measured at a station in the oligotrophic Mediterranean Sea suggests that most of the observed variations in c_{p} can be ascribed to a synchronized population of cells with an equivalent spherical diameter between 1 and 4 μm. The inferred carbon biomass of these cells was about 8–13 mg m^{−3} and accounted for approximately 20% of the total particulate organic carbon. If successfully validated and implemented on autonomous platforms, this method could improve our understanding of the ocean carbon cycle.
Brown, Samuel M; Tate, M Quinn; Jones, Jason P; Kuttler, Kathryn G; Lanspa, Michael J; Rondina, Matthew T; Grissom, Colin K; Mathews, V J
2015-10-01
To determine whether variability of coarsely sampled heart rate and blood pressure early in the course of severe sepsis and septic shock predicts successful resuscitation, defined as vasopressor independence at 24 hours after admission. In an observational study of patients admitted with severe sepsis or septic shock from 2009 to 2011 to either of 2 intensive care units (ICUs) at a tertiary-care hospital, in whom blood pressure was measured via an arterial catheter, we sampled heart rate and blood pressure every 30 seconds over the first 6 hours of ICU admission and calculated the coefficient of variability of those measurements. Primary outcome was vasopressor independence at 24 hours; and secondary outcome was 28-day mortality. We studied 165 patients, of which 97 (59%) achieved vasopressor independence at 24 hours. Overall, 28-day mortality was 15%. Significant predictors of vasopressor independence at 24 hours included the coefficient of variation of heart rate, age, Acute Physiology and Chronic Health Evaluation II, the number of increases in vasopressor dose, mean vasopressin dose, mean blood pressure, and time-pressure integral of mean blood pressure less than 60 mm Hg. Lower sampling frequencies (up to once every 5 minutes) did not affect the findings. Increased variability of coarsely sampled heart rate was associated with vasopressor independence at 24 hours after controlling for possible confounders. Sampling frequencies of once in 5 minutes may be similar to once in 30 seconds. © The Author(s) 2014.
Relative discriminant coefficient based multi-cue fusion for robust object tracking
Jiangtao WANG; Jingyu YANG
2008-01-01
In visual tracking,integrating multiple cues will increase the reliability and robustness of the tracking system in situations where no single cue is reliable.In this paper,a novel multi-cue based tracking method is pre sented under the particle filter framework.Considering both practical distance and Bhattacharvva distance between particles and the target,a parameter called relative discriminant coefficient(RDC)is designed to measure the tracking ability for different features.Multi-cue fusion is carried out in a reweighing manner based on this parameter.Experimental results demonstrate the high robustness and effectiveness of our method in handling appearance changes,cluttered background,illumination changes and occlusions.
Baciu, Florin; Hadǎr, Anton; Sava, Mihaela; Marinel, Stǎnescu Marius; Bolcu, Dumitru
2016-06-01
In this paper it is studied the influence of discontinuities on elastic and mechanical properties of green composite materials (reinforced with fabric of cotton or hemp). In addition, it is studied the way variations of the volume f the reinforcement influences the elasticity modulus and the tensile strength for the studied composite materials. In order to appreciate the difference in properties between different areas of the composite material, and also the dimensions of the defective areas, we have introduced a relative uniformity coefficient with which the mechanical behavior of the studied composite is compared with a reference composite. To validate the theoretical results we have obtained we made some experiments, using green composites reinforced with fabric, with different imperfection introduced special by cutting the fabric.
Effect of spreading coefficient on three-phase relative permeability of nonaqueous phase liquids
Keller, Arturo A.; Chen, Mingjie
2003-10-01
Three-phase flow conditions are encountered regularly, for example, during migration of released NAPL through the vadose zone, certain stages of soil vapor extraction, bioslurping, or generation of gases by microbes. To model three-phase flow, a common approach is to construct three-phase relative permeabilities based on a combination of two-phase relative permeabilities. Although this circumvents a lack of experimental data, it can lead to serious underprediction or overprediction of residual NAPL saturation. This can mislead decision makers that need to predict whether a particular spill will reach the water table or predict the speed of a NAPL front or conduct an assessment of the performance of remediation actions. Experimental data to estimate three-phase relative permeabilities is sparse. A study by [2000a] generated significant experimental information. Their analysis focused on the high NAPL saturation region, given their emphasis on oil reservoir engineering. For environmental applications the low saturation region is of more interest. Using this data set, we derived a set of empirical relations that relate NAPL three-phase relative permeability krn to NAPL saturation Sn and spreading coefficient Cs for Sn less than about 0.1, such that krn = ? where A1 = 0.012 exp (-1.3Cs) and A2 = 2.1 - 0.60Cs + 0.036Cs2. At higher Sn, krn ≈ Sn4, independent of Cs. We present a pore-scale conceptual model that provides a phenomenological basis for the use of Cs as a predictor of krn at low Sn. We then present a number of simulated case studies that highlight the effect of these three-phase relative permeabilities on risk assessment or remediation design.
Lu, Chih-Wei; Chou, Shen-Long; Lee, Yuan-Pern; Xu, Shucheng; Xu, Z F; Lin, M C
2005-06-22
Rate coefficients of the reaction O((3)P) + CH(3)OH in the temperature range of 835-1777 K were determined using a diaphragmless shock tube. O atoms were generated by photolysis of SO(2) with a KrF excimer laser at 248 nm or an ArF excimer laser at 193 nm; their concentrations were monitored via atomic resonance absorption excited by emission from a microwave-discharged mixture of O(2) and He. The rate coefficients determined for the temperature range can be represented by the Arrhenius equation, k(T) = (2.29 +/- 0.18) x 10(-10) exp[-(4210 +/- 100)T] cm(3) molecule(-1) s(-1); unless otherwise noted, all the listed errors represent one standard deviation in fitting. Combination of these and previous data at lower temperature shows a non-Arrhenius behavior described as the three-parameter equation, k(T) = (2.74 +/- 0.07) x 10(-18)T(2.25 +/- 0.13) exp[-(1500 +/- 90)T] cm(3)molecule(-1) s(-1). Theoretical calculations at the Becke-3-Lee-Yang-Parr (B3LYP)6-311 + G(3df,2p) level locate three transition states. Based on the energies computed with coupled clusters singles, doubles (triples) [CCSD(T)]/6-311 + G(3df,2p)B3LYP6-311 + G(3df,2p), the rate coefficients predicted with canonical variational transition state theory with small curvature tunneling corrections agree satisfactorily with the experimental observations. The branching ratios of two accessible reaction channels forming OH + CH(2)OH (1a) and OH + CH(3)O (1b) are predicted to vary strongly with temperature. At 300 K, reaction (1a) dominates, whereas reaction (1b) becomes more important than reaction (1a) above 1700 K.
Chen, Hua-Lin; Chen, Ying-Xu; Xu, Yun-Tai; Shen, Meng-Wei
2004-09-01
To gain information on organic pollutants in water-sediment systems, a compartment model was applied to study the sorption course of phenanthrene and pentachlorophenol (PCP) in sediments. The model described the time-dependent interaction of phenanthrene and PCP with operationally defined reversible and irreversible (or slowly reversible) sediment fractions. The interactions between these fractions were described using first order differential equations. By fitting the models to the experimental data, apparent rate constants were obtained using numerical optimization software. The model optimizations showed that the amount of reversible phase increased rapidly in the first 10 d with the sorption time, then decreased after 10 d, while the amount of irreversible phase increased in the total sorption course. That suggested the mass transport between reversible phase and irreversible phase. The extraction efficiency with hot methanol ranged from 36% to 103% for phenanthrene and from 65% to 101% for PCP, with the trend of decreasing with sorption time.
Glover, Simon C O
2015-01-01
We investigate how uncertainties in the chemical and cooling rate coefficients relevant for a metal-free gas influence our ability to determine the critical ultraviolet field strength required to suppress H2 cooling in high-redshift atomic cooling halos. The suppression of H2 cooling is a necessary prerequisite for the gas to undergo direct collapse and form an intermediate mass black hole. These black holes can then act as seeds for the growth of the supermassive black holes (SMBHs) observed at redshifts $z \\sim 6$. The viability of this model for SMBH formation depends on the critical ultraviolet field strength, Jcrit: if this is too large, then too few seeds will form to explain the observed number density of SMBHs. We show in this paper that there are five key chemical reactions whose rate coefficients are uncertain enough to significantly affect Jcrit. The most important of these is the collisional ionization of hydrogen by collisions with other hydrogen atoms, as the rate for this process is very poorly...
How is entropy production rate related to chemical reaction rate?
Banerjee, Kinshuk
2013-01-01
The entropy production rate is a key quantity in irreversible thermodynamics. In this work, we concentrate on the realization of entropy production rate in chemical reaction systems in terms of the experimentally measurable reaction rate. Both triangular and linear networks have been studied. They attain either thermodynamic equilibrium or a non-equilibrium steady state, under suitable external constraints. We have shown that the entropy production rate is proportional to the square of the reaction velocity only around equilibrium and not any arbitrary non-equilibrium steady state. This feature can act as a guide in revealing the nature of a steady state, very much like the minimum entropy production principle. A discussion on this point has also been presented.
The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50% and 70% RH). A dynamic dual-chamber test meth...
The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50% and 70% RH). A dynamic dual-chamber test meth...
Onel, L; Blitz, M A; Seakins, P W
2012-04-05
Monoethanol amine (H2NCH2CH2OH, MEA) has been proposed for large-scale use in carbon capture and storage. We present the first absolute, temperature-dependent determination of the rate coefficient for the reaction of OH with MEA using laser flash photolysis for OH generation, monitoring OH removal by laser-induced fluorescence. The room-temperature rate coefficient is determined to be (7.61 ± 0.76) × 10(-11) cm(3) molecule(-1) s(-1), and the rate coefficient decreases by about 40% by 510 K. The temperature dependence of the rate coefficient is given by k1= (7.73 ± 0.24) × 10(-11)(T/295)(-(0.79±0.11)) cm(3) molecule(-1) s(-1). The high rate coefficient shows that gas-phase processing in the atmosphere will be competitive with uptake onto aerosols.
Decoupling relations and coefficient functions in SUSY-QCD to three loops
Kurz, Alexander; Steinhauser, Matthias; Zerf, Nikolai [TTP Karlsruhe (Germany)
2012-07-01
A method to calculate decoupling relations between parameters of SUSY-QCD and of QCD is presented. It allows the computation of the decoupling constant of the strong coupling up to O({alpha}{sub s}{sup 3}) which constitutes an important ingredient in the relation between {alpha}{sub s}(M{sub Z}) and {alpha}{sub s}(M{sub GUT}). With the help of a low-energy theorem the calculated decoupling constant can be related to the effective coupling of the scalar Higgs boson to gluons. Similar considerations for the electromagnetic coupling leads to the decay rate of a Higgs boson to photons.
Immink, G. K.
1994-10-01
This paper is concerned with applications of the Mellin transformation in the study of homogeneous linear differential and difference equations with polynomial coefficients. We begin by considering a differential equation (D) with regular singularities at O and ∞ and arbitrary singularities in the rest of the complex plane, and the difference equation (Δ‧) obtained from (D) by a variant of the formal Mellin transformation. We define fundamental systems of solutions of (Δ‧), analytic in either a right or a left half plane. by the use of Mellin transforms of microsolutions of (D). The relations between these fundamental systems are expressed in terms of central connection matrices of (D). Second, we study the differential equation (D1) obtained from (D) by means of a formal Laplace transformation and the difference equation (Δ1) obtained from (D1) by a formal Mellin transformation. We use Mellin transforms of "ordinary" solutions of (D1) with moderate growth at ∞ to construct fundamental systems of solutions of (Δ1). The relation between these fundamental systems involves certain Stokes multipliers and a formal monodromy matrix of (D1).
Bryans, P; Gorczyca, T W; Laming, J M; Mitthumsiri, W; Savin, D W
2006-01-01
Reliably interpreting spectra from electron-ionized cosmic plasmas requires accurate ionization balance calculations for the plasma in question. However, much of the atomic data needed for these calculations have not been generated using modern theoretical methods and are often highly suspect. This translates directly into the reliability of the collisional ionization equilibrium (CIE) calculations. We make use of state-of-the-art calculations of dielectronic recombination (DR) rate coefficients for the hydrogenic through Na-like ions of all elements from He up to and including Zn. We also make use of state-of-the-art radiative recombination (RR) rate coefficient calculations for the bare through Na-like ions of all elements from H through to Zn. Here we present improved CIE calculations for temperatures from $10^4$ to $10^9$ K using our data and the recommended electron impact ionization data of \\citet{Mazz98a} for elements up to and including Ni and Mazzotta (private communication) for Cu and Zn. DR and RR ...
Mahdi Alajmi
2015-07-01
Full Text Available The correlation between the mechanical properties of Fillers/Epoxy composites and their tribological behavior was investigated. Tensile, hardness, wear, and friction tests were conducted for Neat Epoxy (NE, Graphite/Epoxy composites (GE, and Data Palm Fiber/Epoxy with or without Graphite composites (GFE and FE. The correlation was made between the tensile strength, the modulus of elasticity, elongation at the break, and the hardness, as an individual or a combined factor, with the specific wear rate (SWR and coefficient of friction (COF of composites. In general, graphite as an additive to polymeric composite has had an eclectic effect on mechanical properties, whereas it has led to a positive effect on tribological properties, whilst date palm fibers (DPFs, as reinforcement for polymeric composite, promoted a mechanical performance with a slight improvement to the tribological performance. Statistically, this study reveals that there is no strong confirmation of any marked correlation between the mechanical and the specific wear rate of filler/Epoxy composites. There is, however, a remarkable correlation between the mechanical properties and the friction coefficient of filler/Epoxy composites.
Alajmi, Mahdi; Shalwan, Abdullah
2015-07-08
The correlation between the mechanical properties of Fillers/Epoxy composites and their tribological behavior was investigated. Tensile, hardness, wear, and friction tests were conducted for Neat Epoxy (NE), Graphite/Epoxy composites (GE), and Data Palm Fiber/Epoxy with or without Graphite composites (GFE and FE). The correlation was made between the tensile strength, the modulus of elasticity, elongation at the break, and the hardness, as an individual or a combined factor, with the specific wear rate (SWR) and coefficient of friction (COF) of composites. In general, graphite as an additive to polymeric composite has had an eclectic effect on mechanical properties, whereas it has led to a positive effect on tribological properties, whilst date palm fibers (DPFs), as reinforcement for polymeric composite, promoted a mechanical performance with a slight improvement to the tribological performance. Statistically, this study reveals that there is no strong confirmation of any marked correlation between the mechanical and the specific wear rate of filler/Epoxy composites. There is, however, a remarkable correlation between the mechanical properties and the friction coefficient of filler/Epoxy composites.
Amarante, A.; Lanoiselle, J.L.; Ramirez, A.
2003-10-01
Heat exchange is often complex to assess in freezing equipment. Either the extensive calculation procedures based on product time-temperature data, or the lack of accurate thermophysical properties, or even the non-uniform processing conditions in industrial equipment, results in increased difficulty in calculating accurate heat exchange parameters. The present study aims to solve this kind of problem by introducing the use of heat flux sensors (or fluxmeters) for an online measurement of heat exchange parameters during freezing processes. Since food products often have irregular, moist and greasy surfaces, bad attachment of the sensors can lead to low accuracy in heat flux measurement. First, a technique was improved in this particular and a numerical procedure based on matching the experimental and simulated temperature histories was used to calibrate the sensors attached to Tylose gels submitted to freezing and thawing cycles. Following this, the sensors were applied directly to a vegetable product undergoing freezing in a static freezer to measure the instantaneous product heat release rate and the local heat transfer coefficient. A fluxmeter-plastic transducer was also developed and used, coupled to an anemometer to map axially and transversally the local effective heat transfer coefficient and air speed profiles in a Super-Contact freezing tunnel. Results were compared with numerical simulations and showed good agreement. Irregular air speed distribution and low efficiency heat transfer zones were accurately detected, providing information for equipment optimization. (author)
Ghasemi, F; Peinke, J; Tabar, M R R; Sahimi, Muhammad
2006-01-01
We describe a method for analyzing the stochasticity in the non-stationary data for the beat-to-beat fluctuations in the heart rates of healthy subjects, as well as those with congestive heart failure. The method analyzes the returns time series of the data as a Markov process, and computes the Markov time scale, i.e., the time scale over which the data are a Markov process. We also construct an effective stochastic continuum equation for the return series. We show that the drift and diffusion coefficients, as well as the amplitude of the returns time series for healthy subjects are distinct from those with CHF. Thus, the method may potentially provide a diagnostic tool for distinguishing healthy subjects from those with congestive heart failure, as it can distinguish small differences between the data for the two classes of subjects in terms of well-defined and physically-motivated quantities.
Coppola, Carla Maria; Galli, Daniele; Tennyson, Jonathan; Longo, Savino
2012-01-01
Energy exchange processes play a crucial role in the early Universe, affecting the thermal balance and the dynamical evolution of the primordial gas. In the present work we focus on the consequences of a non-thermal distribution of the level populations of H$_2$: first, we determine the excitation temperatures of vibrational transitions and the non-equilibrium heat transfer; second, we compare the modifications to chemical reaction rate coefficients with respect to the values obtained assuming local thermodynamic equilibrium; third, we compute the spectral distortions to the cosmic background radiation generated by the formation of H$_2$ in vibrationally excited levels. We conclude that non-equilibrium processes cannot be ignored in cosmological simulations of the evolution of baryons, although their observational signatures remain below current limits of detection. New fits to the equilibrium and non-equilibrium heat transfer functions are provided.
Rajesh, S.; Murali, K. P.; Jantunen, H.; Ratheesh, R.
2011-11-01
High permittivity and low-loss ceramic fillers have been prepared by means of the solid state ceramic route. Ceramic-filled composites were prepared by the Sigma Mixing, Extrusion, Calendering, which was followed by the Hot pressing (SMECH) process. The microwave dielectric properties of the composites were studied using X-band waveguide cavity perturbation technique. The temperature coefficient of the relative permittivity of the composites was investigated in the 0-100 °C temperature range using a hot and cold chamber coupled with an impedance analyzer. The temperature coefficient of the relative permittivity of the composites showed strong dependence on the temperature coefficient of the relative permittivity of the filler material. In the present study, a high-permittivity polymer/ceramic composite, having τεr ∼63 ppm/K, has been realized. This composite is suitable for outdoor wireless applications.
Mikhailov, A. V.; K. Schlegel
2000-01-01
There are differences between existing models of solar EUV with λ < 1050 Å and between laboratory measurements of the O+ + N2 – reaction rate coefficient, both parameters being crucial for the F2-region modeling. Therefore, indirect aeronomic estimates of these parameters may be useful for qualifying the existing EUV models and the laboratory measured O+ + N2 – rate coefficient. A modified self-consistent method for daytime F2-region modeling developed by Mi...
Feofilov, A. G.; Kutepov, A. A.; She, C.-Y.; Smith, A. K.; Pesnell, W. D.; Goldberg, R. A.
2012-01-01
Among the processes governing the energy balance in the mesosphere and lower thermosphere (MLT), the quenching of CO2(nu2) vibrational levels by collisions with O atoms plays an important role. However, there is a factor of 3-4 discrepancy between the laboratory measurements of the CO2-O quenching rate coefficient, k(sub VT),and its value estimated from the atmospheric observations. In this study, we retrieve k(sub VT) in the altitude region85-105 km from the coincident SABER/TIMED and Fort Collins sodium lidar observations by minimizing the difference between measured and simulated broadband limb 15 micron radiation. The averaged k(sub VT) value obtained in this work is 6.5 +/- 1.5 X 10(exp -12) cubic cm/s that is close to other estimates of this coefficient from the atmospheric observations.However, the retrieved k(sub VT) also shows altitude dependence and varies from 5.5 1 +/-1 10(exp -12) cubic cm/s at 90 km to 7.9 +/- 1.2 10(exp -12) cubic cm/s at 105 km. Obtained results demonstrate the deficiency in current non-LTE modeling of the atmospheric 15 micron radiation, based on the application of the CO2-O quenching and excitation rates, which are linked by the detailed balance relation. We discuss the possible model improvements, among them accounting for the interaction of the non-thermal oxygen atoms with CO2 molecules.
Kurnosov, Alexander; Cacciatore, Mario; Laganà, Antonio; Pirani, Fernando; Bartolomei, Massimiliano; Garcia, Ernesto
2014-04-05
The rate coefficients for N2-N2 collision-induced vibrational energy exchange (important for the enhancement of several modern innovative technologies) have been computed over a wide range of temperature. Potential energy surfaces based on different formulations of the intramolecular and intermolecular components of the interaction have been used to compute quasiclassically and semiclassically some vibrational to vibrational energy transfer rate coefficients. Related outcomes have been rationalized in terms of state-to-state probabilities and cross sections for quasi-resonant transitions and deexcitations from the first excited vibrational level (for which experimental information are available). On this ground, it has been possible to spot critical differences on the vibrational energy exchange mechanisms supported by the different surfaces (mainly by their intermolecular components) in the low collision energy regime, though still effective for temperatures as high as 10,000 K. It was found, in particular, that the most recently proposed intermolecular potential becomes the most effective in promoting vibrational energy exchange near threshold temperatures and has a behavior opposite to the previously proposed one when varying the coupling of vibration with the other degrees of freedom.
K. Schlegel
Full Text Available There are differences between existing models of solar EUV with λ < 1050 Å and between laboratory measurements of the O+ + N2 – reaction rate coefficient, both parameters being crucial for the F2-region modeling. Therefore, indirect aeronomic estimates of these parameters may be useful for qualifying the existing EUV models and the laboratory measured O+ + N2 – rate coefficient. A modified self-consistent method for daytime F2-region modeling developed by Mikhailov and Schlegel was applied to EISCAT observations (32 quiet summer and equinoctial days to estimate the set of main aeronomic parameters. Three laboratory measured temperature dependencies for the O+ + N2 – rate coefficient were used in our calculations to find self-consistent factors both for this rate coefficient and for the solar EUV flux model from Nusinov. Independent of the rate coefficient used, the calculated values group around the temperature dependence recently measured by Hierl et al. in the 850–1400 K temperature range. Therefore, this rate coefficient may be considered as the most preferable and is recommended for aeronomic calculations. The calculated EUV flux shows a somewhat steeper dependence on solar activity than both, the Nusinov and the EUVAC models predict. In practice both EUV models may be recommended for the F2-region electron density calculations with the total EUV flux shifted by ±25% for the EUVAC and Nusinov models, correspondingly.Key words: Ionosphere (ion chemistry and composition; ionosphere atmosphere interactions; modeling and forecasting
Anders, R.; Chrysikopoulos, C. V.
2004-12-01
Batch experiments were conducted under both static and dynamic conditions to study the effects of temperature and the presence of sand on the inactivation process of viruses. The male--specific RNA coliphage, MS2, and the Salmonella typhimurium phage, PRD1, were used as model viruses for this study. Over 100 oven--baked borosilicate glass bottles with or without Monterey sand were filled with a low--ionic--strength phosphate buffered saline solution containing both bacteriophage and incubated at temperatures of 4o, 15o, or 25oC. The results of the batch experiments indicate that the inactivation process can be represented by a pseudo first-order expression with time--dependent rate coefficients. A combination of high temperature and the presence of sand appears to produce the greatest disruption to the surrounding protein coat of MS2. However, for PRD1, the lower activation energies derived from Arrhenius plots indicate a weaker dependence of the inactivation rate on temperature. Furthermore, the presence of an air--liquid--solid interface in the dynamic batch experiment containing sand produces the greatest damage to specific viral components of PRD1 that are required for infection. These results indicate the use of thermodynamic parameters based on the pseudo first--order inactivation expression allows better prediction of the inactivation of viruses in the environment.
Konstantinos Katsonis
2013-01-01
Full Text Available We developed a Global Model for N2O plasmas valid for applications in various power, gas flow rate, and pressure regimes. Besides energy losses from electron collisions with N2O, it takes into consideration those due to molecular N2 and O2 and to atomic N and O species. Positive atomic N+ and O+ and molecular N2O+, N2+, and O2+ have been treated as separate species and also negative O− ions. The latter confer an electronegative character to the discharge, calling for modified plasma sheath and plasma potential formulas. Electron density and temperature and all species densities have been evaluated, hence the ionization and dissociation percentages of N2O, N2, and O2 molecules and the plasma electronegativity. The model is extended to deal with N2/O2 mixtures feedings, notably with air. Rate coefficients and model results are discussed and compared with those from available theoretical and experimental work on ICP and glow discharge devices.
Dorian, Matthew; Seitaridou, Effrosyni
2014-03-01
Understanding the rate of biofilm growth is essential for studying genes and preventing unwanted biofilms. In this study, the diffusion coefficient (D) of polystyrene microspheres was used to quantify biofilm growth rates of Sinorhizobia meliloti, a nitrogen fixing bacteria that forms a symbiotic relationship with alfalfa plants. Five strains were studied, two wild types (8530 expR+ and 1021) and three mutants in the exopolysaccharide (EPS I, EPS II) synthesis (8530 exoY , 9034 expG , and 9030-2 expA 1); 1021 and 9030-2 expA 1 are known to be unable to form biofilms. Each strain was inserted into a microfluidic channel with the microspheres. As the cultures grew, the spheres' D values were obtained every 24 hours for 4 days using fluorescence microscopy. Although the D values for 9030-2 expA 1 were inconclusive, 8530 expR+ , 8530 exoY , and 9034 expG showed significant decreases in D between 3 days of growth (| z | > 2 . 25 , p 0 . 05), which shows the lack of a structured biofilm community. Thus, D can be used as an indicator of the presence of a biofilm and its development.
Relative growth rate of rich fen bryophytes
Andersen, Dagmar Kappel; Ejrnæs, Rasmus; Riis, Tenna
Rigkær er blandt den nordlige halvkugles mest artsrige naturtyper, og en lang række sjældne og truede plantearter er knyttet til netop disse områder. I dette forsøg undersøges den relative vækstrate hos to almindelige og to sjældne rigkærsmosser i relation til forskellige niveauer af næringsstoff...
"Molecular Clock" Analogs: A Relative Rates Exercise
Wares, John P.
2008-01-01
Although molecular clock theory is a commonly discussed facet of evolutionary biology, undergraduates are rarely presented with the underlying information of how this theory is examined relative to empirical data. Here a simple contextual exercise is presented that not only provides insight into molecular clocks, but is also a useful exercise for…
Haas, C; Drenth, J; Wilson, WW
1999-01-01
Tn recent publications it was pointed out that there is a correlation between the observed values of the solubility of proteins in aqueous solutions and the second virial coefficient of the solution. In this paper we give a theoretical explanation of this relation. The derived theoretical expression
Haas, C; Drenth, J; Wilson, WW
1999-01-01
Tn recent publications it was pointed out that there is a correlation between the observed values of the solubility of proteins in aqueous solutions and the second virial coefficient of the solution. In this paper we give a theoretical explanation of this relation. The derived theoretical expression
Dragan Vidić
2012-12-01
Full Text Available Dimension stone is a highly valuable mineral raw material per unit of product. From the past experiences and literature it is known that for a certain quantity of commercial blocks, dimension stone should be dug (cut out is significantly larger volume of natural (raw rock mass. Stone residue, resulting in gaining the commercial dimension stone blocks, is usually less value per unit of product. Profitability of the dimension stone exploitation in a deposit is directly dependent on the rock coefficient of utilization. It is therefore a priority task and a challenge to improve the efficiency of dimension stone deposits utilization and reduce the accumulation of mineral residue that would ultimately increase profits. Dependence of profitability on coefficient of utilization of dimension stone deposits can be best expressed by numerical models, as shown in this paper.
无
2010-01-01
In this paper, a class of stochastic differential equations (SDEs) driven by semi-martingale with non-Lipschitz coefficients is studied. We investigate the dependence of solutions to SDEs on the initial value. To obtain a continuous version, we impose the conditions on the local characteristic of semimartingale. In this case, it gives rise to a flow of homeomorphisms if the local characteristic is compactly supported.
Choi, Kilchan; Seltzer, Michael
2010-01-01
In studies of change in education and numerous other fields, interest often centers on how differences in the status of individuals at the start of a period of substantive interest relate to differences in subsequent change. In this article, the authors present a fully Bayesian approach to estimating three-level Hierarchical Models in which latent…
Pfrang, C.; Kasyutich, V. L.; Canosa-Mas, C. E.; Vaughan, S.; Wayne, R. P.
2003-04-01
The nitrate radical, NO_3, is a key species in the night-time tropospheric oxidation of a variety of volatile organic compounds (VOCs), including those emitted by living vegetation. In addition to the VOC emissions from intact plants, it is well known that wounding induces the release of a series of C_6 aldehydes and C_6 alcohols, as can be readily sensed in the odour of freshly mown grass. Large emissions of the "leaf alcohol", (Z)-3-hexenol, have been observed after wounding, during drying, and following pathogen attack, while (Z)-2-hexenol has been reported as an emission from clipped clover. Rate coefficients for the gas-phase reactions of the nitrate radical with these two isomeric compounds have been measured using the discharge-flow technique at room temperature. Because of the relatively low volatility of these compounds, it is necessary to employ low concentrations of NO_3 in order to determine the kinetics satisfactorily. To this end, we used a technique not hitherto applied in kinetic experiments on NO_3: that of off-axis continuous-wave cavity-enhanced absorption spectroscopy (CW CEAS) for the detection of NO_3, using a broadband absorption line at λ = 662 nm. A noise-equivalent detection sensitivity of 5.5 × 10^9 molecule cm-3 for the nitrate radical (Kasyutich et al., Appl. Phys. B, 2002, 75, 755--761) enabled us to work with the hexenol compounds in excess over NO_3. The rate coefficients were determined to be (2.80 ± 0.12) × 10-13 cm^3 molecule-1 s-1 and (1.36 ± 0.08) × 10-13 cm^3 molecule-1 s-1, respectively, for (Z)-3-hexenol and (Z)-2-hexenol. The rate constant for reaction with (Z)-3-hexenol lies within the combined error limits of the single measurement of the rate coefficient using relative rate methods of (2.72 ± 0.83) × 10-13 cm^3 molecule-1 s-1 (Atkinson et al., Int. J. Chem. Kinetics, 1995, 27, 941--955). However, for (Z)-3-hexenol there is some evidence for upward curvature of the second-order plot at longer contact times, and
Zogka, Antonia G; Mellouki, Abdelwahid; Romanias, Manolis N; Bedjanian, Yuri; Idir, Mahmoud; Grosselin, Benoit; Daële, Véronique
2016-11-17
The rate coefficients for the reactions of OH and Cl with 1-methoxy 2-propyl acetate (MPA) in the gas phase were measured using absolute and relative methods. The kinetic study on the OH reaction was conducted in the temperature (263-373) K and pressure (1-760) Torr ranges using the pulsed laser photolysis-laser-induced fluorescence technique, a low pressure fast flow tube reactor-quadrupole mass spectrometer, and an atmospheric simulation chamber/GC-FID. The derived Arrhenius expression is kMPA+OH(T) = (2.01 ± 0.02) × 10(-12) exp[(588 ± 123/T)] cm(3) molecule(-1) s(-1). The absolute and relative rate coefficients for the reaction of Cl with MPA were measured at room temperature in the flow reactor and the atmospheric simulation chamber, which led to k(Cl+MPA) = (1.98 ± 0.31) × 10(-10) cm(3) molecule(-1) s(-1). GC-FID, GC-MS, and FT-IR techniques were used to investigate the reaction mechanism in the presence of NO. The products formed from the reaction of MPA with OH and their yields were methyl formate (80 ± 7.3%), acetic acid (50 ± 4.8%), and acetic anhydride (22 ± 2.4%), while for Cl reaction, the obtained yields were 60 ± 5.4, 41 ± 3.8, and 11 ± 1.2%, respectively, for the same products. The UV absorption cross section spectrum of MPA was determined in the wavelength range 210-370 nm. The study has shown no photolysis of MPA under atmospheric conditions. The obtained results are used to derive the atmospheric implication.
Jubb, Aaron M; Gierczak, Tomasz; Baasandorj, Munkhbayar; Waterland, Robert L; Burkholder, James B
2014-05-06
Mixtures of methyl-perfluoroheptene-ethers (CH3OC7F13, MPHEs) are currently in use as replacements for perfluorinated alkanes (PFCs) and poly-ether heat transfer fluids, which are persistent greenhouse gases with lifetimes >1000 years. At present, the atmospheric processing and environmental impact from the use of MPHEs is unknown. In this work, rate coefficients at 296 K for the gas-phase reaction of the OH radical with six key isomers (including stereoisomers and enantiomers) of MPHEs used commercially were measured using a relative rate method. Rate coefficients for the six MPHE isomers ranged from ∼ 0.1 to 2.9 × 10(-12) cm(3) molecule(-1) s(-1) with a strong stereoisomer and -OCH3 group position dependence; the (E)-stereoisomers with the -OCH3 group in an α- position relative to the double bond had the greatest reactivity. Rate coefficients measured for the d3-MPHE isomer analogues showed decreased reactivity consistent with a minor contribution of H atom abstraction from the -OCH3 group to the overall reactivity. Estimated atmospheric lifetimes for the MPHE isomers range from days to months. Atmospheric lifetimes, radiative efficiencies, and global warming potentials for these short-lived MPHE isomers were estimated based on the measured OH rate coefficients along with measured and theoretically calculated MPHE infrared absorption spectra. Our results highlight the importance of quantifying the atmospheric impact of individual components in an isomeric mixture.
Sterling, N C
2011-01-01
We present total and final-state resolved charge transfer (CT) rate coefficients for low-charge Ge, Se, Br, Kr, Rb, and Xe ions reacting with neutral hydrogen over the temperature range 10^2--10^6 K. Each of these elements has been detected in ionized astrophysical nebulae, particularly planetary nebulae. CT rate coefficients are a key ingredient for the ionization equilibrium solutions needed to determine total elemental abundances from those of the observed ions. A multi-channel Landau Zener approach was used to compute rate coefficients for projectile ions with charges q=2-5, and for singly-charged ions the Demkov approximation was utilized. Our results for five-times ionized species are lower limits, due to the incompleteness of level energies in the NIST database. In addition, we computed rate coefficients for charge transfer ionization reactions between the neutral species of the above six elements and ionized hydrogen. The resulting total and state-resolved CT rate coefficients are tabulated and availa...
Ćosić Mladen
2015-01-01
Full Text Available The paper deals with methodology developed and presented for analyzing the damage on structures exposed to accidental and seismic actions. The procedure is based on non-linear numerical analysis, taking into account the principles of Performance-Based Seismic Design (PBSD. The stiffness matrix of the effects of vertical action is used as the initial stiffness matrix in non-linear analysis which simulates the collapse of individual ground-floor columns, forming thereby a number of possible scenarios. By the end of the analysis that simulates the collapse of individual columns, the stiffness matrix is used as the initial stiffness matrix for Non-linear Static Pushover Analysis (NSPA of bi-directional seismic action (X and Y directions. Target displacement analyses were conducted using the Capacity Spectrum Method (CSM. The structure's conditions/state was assessed based on the calculated global and inter-storey drifts and the damage coefficient developed. The damage level to the building was established using an integrated approach based on global and inter-storey drifts, so that, depending on the level of displacements for which the drifts are identified, a more reliable answer can be obtained. Applying the damage coefficient, a prompt, reliable and accurate indication can be obtained on the damage level to the entire structure in the capacitive domain, from elastic and non-linear to collapse state.
Pamboundom, Mama; Tchakoua, Théophile; Nsangou, Mama
2016-04-01
In this work, inelastic rotational collision of AlCl with helium was studied. The CCSD(T) method was used for the computation of an accurate two dimensional potential energy surface (PES). In the calculation of the PES, Al-Cl bond was frozen at the experimental value 4.02678 a0. The aug-cc-pVQZ basis sets of Dunning was used throughout the computational process. This basis was completed with a set of 3s3p2d2f1g bond functions placed at mid-distance between the center of mass of AlCl and He atom for a better description of the van der Waals interaction energy. The PES of AlCl-He was found to have a global minimum at (R=8.65 a0, θ=0 degree), a local minimum at (R=7.45 a0, θ=82 degree) and a saddle point at (R=7.9 a0, θ=56 degree). The depths of the minima were 20.2 cm^{-1} and 19.8 cm^{-1} respectively for θ=0 and 84 degrees. The height of the saddle point with respect to the global minimum was 1.3 cm^{-1}. The PES, the result of an analytical fit, was expanded in terms of Legendre polynomials, then used for the evaluation of state-to-state rotational integral cross sections for the collision of AlCl with He in the close coupling approach. The collisional cross sections for the transitions occurring among the 17 first rotational levels of AlCl were calculated for kinetic energies up to 4000 cm^{-1}. Collisional rate coefficients between these rotational levels were computed for low and moderate kinetic temperatures ranging from 30 to 500 K. A propensity rule that favors odd Δ j transitions was found.
Toyoshima, S.; Noguchi, K.; Seto, H.; Shimizu, M.; Watanabe, N. [Toyama Medical and Pharmaceutical Univ. (Japan). Dept. of Radiology
2000-11-01
To determine the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted MR imaging and split renal function determined by renal scintigraphy in patients with hydronephrosis. Material and Methods: Diffusion-weighted imaging on a 1.5 T MR unit and renal scintigraphy were performed in 36 patients with hydronephrosis (45 hydronephrotic kidneys, 21 non-hydronephrotic kidneys). ADC values of the individual kidneys were measured by diffusion-weighted MR imaging. Split renal function (glomerular filtration rate (GFR)) was determined by renal scintigraphy using {sup 99m}Tc-DTPA. The relationship between ADC values and split GFR was examined in 66 kidneys. The hydronephrotic kidneys were further classified into three groups (severe renal dysfunction, GFR <10 ml/min, n=7; moderate renal dysfunction, GFR 10-25 ml/min, n=10; normal renal function, GFR >25 ml/min, n=28), and mean values for ADCs were calculated. Results: In hydronephrotic kidneys, there was a moderate positive correlation between ADC values and split GFR (R2=0.56). On the other hand, in non-hydronephrotic kidneys, poor correlation between ADC values and split GFR was observed (R2=0.08). The mean values for ADCs of the dysfunctioning hydronephrotic kidneys (severe renal dysfunction, 1.32x10{sup -3}{+-}0.18x10{sup -3} mm{sup 2}/s; moderate renal dysfunction, 1.38x10{sup -3}{+-}0.10x10{sup -3} mm2/s) were significantly lower than that of the normal functioning hydronephrotic kidneys (1.63x10{sup -3}{+-}0.12{+-}10{sup -3} mm{sup 2}/s). Conclusion: These results indicated that measurement of ADC values by diffusion-weighted MR imaging has a potential value in the evaluation of the functional status of hydronephrotic kidneys.
Torr, D. G.; Orsini, N.
1978-01-01
The Atmosphere Explorer (AE) data are reexamined in the light of new laboratory measurements of the N2(+) recombination rate coefficient alpha. The new measurements support earlier measurements which yielded values of alpha significantly lower than the AE values. It is found that the values for alpha determined from the satellite data can be reconciled with the laboratory measurements, if the charge exchange rate coefficient for O(+)(2D) with N2 is less than one-quarter of that derived in the laboratory by Rutherford and Vroom (1971).
Xu, Xiaohong; Chen, Yu; Jia, Haiwei
2009-07-01
The paper study the relation between Interest rate and Inflation rate, we use the Stepwise Regression Method to build the math model about the relation between Interest rate and Inflation rate. And the model has passed the significance test, and we use the model to discuss the influence on social economy through adjust Deposit rate, so we can provide a lot of theory proof for government to draw policy.
Gugushvili, S.; Spreij, P.
2016-01-01
We consider the problem of non-parametric estimation of the deterministic dispersion coefficient of a linear stochastic differential equation based on discrete time observations on its solution. We take a Bayesian approach to the problem and under suitable regularity assumptions derive the posteror
Liu, Yan; Wu, Amery D.; Zumbo, Bruno D.
2010-01-01
In a recent Monte Carlo simulation study, Liu and Zumbo showed that outliers can severely inflate the estimates of Cronbach's coefficient alpha for continuous item response data--visual analogue response format. Little, however, is known about the effect of outliers for ordinal item response data--also commonly referred to as Likert, Likert-type,…
Liu, Yan; Wu, Amery D.; Zumbo, Bruno D.
2010-01-01
In a recent Monte Carlo simulation study, Liu and Zumbo showed that outliers can severely inflate the estimates of Cronbach's coefficient alpha for continuous item response data--visual analogue response format. Little, however, is known about the effect of outliers for ordinal item response data--also commonly referred to as Likert, Likert-type,…
Causal Rate Distortion Function and Relations to Filtering Theory
Charalambous, Charalambos D; Kourtellaris, Christos K
2011-01-01
A causal rate distortion function is defined, its solution is described, and its relation to filtering theory is discusssed. The relation to filtering is obtained via a causal constraint imposed on the reconstruction kernel to be realizable.
Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei
2015-01-01
Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.
Li, Yongle; Suleimanov, Yury V; Li, Jun; Green, William H; Guo, Hua
2013-03-07
The thermal rate coefficients and kinetic isotope effects have been calculated using ring polymer molecular dynamics (RPMD) for the prototypical reactions between methane and several hydrogen isotopes (H, D, and Mu). The excellent agreement with the theoretical rate coefficients of the H + CH4 reaction obtained previously from a multi-configuration time-dependent Hartree calculation on the same potential energy surface provides strong evidence for the accuracy of the RPMD approach. These quantum mechanical rate coefficients are also in good agreement with the results obtained previously using the transition-state theory with semi-classical tunneling corrections for the H∕D + CH4 reactions. However, it is shown that the RPMD rate coefficients for the ultralight Mu reaction with CH4 are significantly smaller than the experimental data, presumably suggesting inaccuracies in the potential energy surface and∕or experimental errors. Significant discrepancies between the RPMD and transition-state theory results have also been found for this challenging system.
Wenn, Benjamin; Junkers, Thomas
2016-05-01
For the first time, a 1000 Hz pulse laser has been applied to determine detailed kinetic rate coefficients from pulsed laser polymerization-size exclusion chromatography experiments. For the monomer tert-butyl acrylate, apparent propagation rate coefficients kp (app) have been determined in the temperature range of 0-80 °C. kp (app) in the range of few hundreds to close to 50 000 L·mol(-1) ·s(-1) are determined for low and high pulse frequencies, respectively. The apparent propagation coefficients show a distinct pulse-frequency dependency, which follows an S-shape curve. From these curves, rate coefficients for secondary radial propagation (kp (SPR) ), backbiting (kbb ), midchain radical propagation (kp (tert) ), and the (residual) effective propagation rate (kp (eff) ) can be deduced via a herein proposed simple Predici fitting procedure. For kp (SPR) , the activation energy is determined to be (17.9 ± 0.6) kJ·mol(-1) in excellent agreement with literature data. For kbb , an activation energy of (25.9 ± 2.2) kJ·mol(-1) is deduced.
Assessing the relative rate of (mitochondrial) genomic change.
Dowton, Mark
2004-01-01
I report a framework for assessing whether one mitochondrial genome is significantly more rearranged than another. This relative rate of gene rearrangement test (RGR) behaves according to expectation, distinguishing between highly rearranged and mildly rearranged insect mitochondrial genomes. It may be more broadly applied to assess the relative rate of nuclear gene rearrangement.
Assessing the relative rate of (mitochondrial) genomic change.
Dowton, Mark
2004-06-01
I report a framework for assessing whether one mitochondrial genome is significantly more rearranged than another. This relative rate of gene rearrangement test (RGR) behaves according to expectation, distinguishing between highly rearranged and mildly rearranged insect mitochondrial genomes. It may be more broadly applied to assess the relative rate of nuclear gene rearrangement.
Zhu, Xi-Ming; Cheng, Zhi-Wen; Carbone, Emile; Pu, Yi-Kang; Czarnetzki, Uwe
2016-08-01
Electron-impact excitation processes play an important role in low-temperature plasma physics. Cross section and rate coefficient data for electron-impact processes from the ground state to excited states or between two excited states are required for both diagnostics and modeling works. However, the collisional processes between excited states are much less investigated than the ones involving the ground state due to various experimental challenges. Recently, a method for determining electron excitation rate coefficients between Ar excited states in afterglow plasmas was successfully implemented and further developed to obtain large sets of collisional data. This method combines diagnostics for electron temperature, electron density, and excited species densities and kinetic modeling of excited species, from which the electron excitation rate coefficients from one of the 1s states to the other 1s states or to one of 2p or 3p states are determined (states are in Paschen’s notation). This paper reviews the above method—namely the combined diagnostics and modeling in afterglow plasmas. The results from other important approaches, including electron-beam measurement of cross sections, laser pump-probe technique for measuring rate coefficients, and theoretical calculations by R-matrix and distorted-wave models are also discussed. From a comparative study of these results, a fitted mathematical expression of excitation rate coefficients is obtained for the electron temperature range of 1-5 eV, which can be used for the collisional-radiative modeling of low-temperature Ar plasmas. At last, we report the limitations in the present dataset and give some suggestions for future work in this area.
Xin Wen
2009-01-01
In this paper we give proof of three binomial coefficient inequalities. These inequalities are key ingredients in [Wen and Jin, J. Comput. Math. 26, (2008), 1-22] to establish the L1-error estimates for the upwind difference scheme to the linear advection equations with a piecewise constant wave speed and a general interface condition, which were further used to establish the L1-error estimates for a Hamiltonian-preserving scheme developed in [Jin and Wen, Commun. Math. Sci. 3, (2005), 285-315] to the Liouville equation with piecewise constant potentials [Wen and Jin, SIAM J. Numer. Anal. 46, (2008), 2688-2714].
Wheeler, David C.; Waller, Lance A.
2009-03-01
In this paper, we compare and contrast a Bayesian spatially varying coefficient process (SVCP) model with a geographically weighted regression (GWR) model for the estimation of the potentially spatially varying regression effects of alcohol outlets and illegal drug activity on violent crime in Houston, Texas. In addition, we focus on the inherent coefficient shrinkage properties of the Bayesian SVCP model as a way to address increased coefficient variance that follows from collinearity in GWR models. We outline the advantages of the Bayesian model in terms of reducing inflated coefficient variance, enhanced model flexibility, and more formal measuring of model uncertainty for prediction. We find spatially varying effects for alcohol outlets and drug violations, but the amount of variation depends on the type of model used. For the Bayesian model, this variation is controllable through the amount of prior influence placed on the variance of the coefficients. For example, the spatial pattern of coefficients is similar for the GWR and Bayesian models when a relatively large prior variance is used in the Bayesian model.
Li, Yongle; Suleimanov, Yury V; Green, William H; Guo, Hua
2014-03-20
Thermal rate coefficients and kinetic isotope effect have been calculated for prototypical heavy-light-heavy polyatomic bimolecular reactions Cl + CH4/CD4 → HCl/DCl + CH3/CD3, using a recently proposed quantum dynamics approach: ring polymer molecular dynamics (RPMD). Agreement with experimental rate coefficients, which are quite scattered, is satisfactory. However, differences up to 50% have been found between the RPMD results and those obtained from the harmonic variational transition-state theory on one of the two full-dimensional potential energy surfaces used in the calculations. Possible reasons for such discrepancy are discussed. The present work is an important step in a series of benchmark studies aimed at assessing accuracy for RPMD for chemical reaction rates, which demonstrates that this novel method is a quite reliable alternative to previously developed techniques based on transition-state theory.
Chu V. Nguyen
2015-12-01
Full Text Available Asymmetries in the Vietnamese lending central bank’s policy-related rate spread were documented. Empirical results revealed that the spread adjusts to the threshold faster when the central bank’s policy-related rates decrease relative to the lending rates than when the central bank’s policy-related rates move in the opposite direction. Additionally, the empirical findings indicate that Vietnamese commercial banks exhibit competitive rate setting behavior which may be attributable to graft maximization by bank’s management. The results also show bidirectional Granger causality between the Vietnamese lending rate and the central bank’s policy-related rate, indicating that the lending rate and the central bank’s policy-related rate affect each other’s movements. These results suggest that monetary authority can use its countercyclical monetary policy instruments to achieve its macroeconomics objectives. However, the estimation results of the GARCH (2, 3-in-Mean model suggest that they should intervene more frequently and by small policy measures to minimize the conditional variance of the spread to minimize the magnitude of the cycle of the lending rate.
Periodic Sturm-Liouville problems related to two Riccati equations of constant coefficients
Khmelnytskaya, K V; González, A
2009-01-01
We consider two closely related Riccati equations of constant parameters whose particular solutions are used to construct the corresponding class of supersymmetrically-coupled second-order differential equations. We solve analytically these parametric periodic problems along the positive real axis. Next, the analytically solved model is used as a case study for a powerful numerical approach that is employed here for the first time in the investigation of the energy band structure of periodic not necessarily regular potentials. The approach is based on the well-known self-matching procedure of James (1949) and implements the spectral parameter power series solutions introduced by Kravchenko (2008). We obtain additionally an efficient series representation of the Hill discriminant based on Kravchenko's series
Temperature-related changes in respiration and Q10 coefficient of Guava
Bron Ilana Urbano
2005-01-01
Full Text Available Guava (Psidium guajava L. is a tropical fruit that presents fast post-harvest ripening; therefore it is a very perishable product. Inappropriate storage temperature and retail practices can accelerate fruit quality loss. The objective of this study was to evaluate the respiratory activity (RA, the ethylene production (EP and Q10 of guava fruit at different storage temperatures. 'Paluma' guava fruits were harvested at maturity stage 1 (dark-green skin and stored at either 1, 11, 21, 31 or 41ºC; RA and EP were determined after 12, 36, 84 and 156 h of storage. RA and EP rates at 1 and 11ºC were the lowest - 0.16 and 0.43 mmol CO2 kg-1 h-1 and 0.003 and 0.019 µmol C2H4 kg-1 h-1, respectively. When guavas were stored at 21ºC, a gradual increase occurred in RA and EP, reaching 2.24 mmol CO2 kg-1 h-1 and 0.20 µmol C2H4 kg-1 h-1, after 156 h of storage. The highest RA and EP were recorded for guavas stored at 31ºC. In spite of high RA, guavas stored at 41ºC presented EP similar to guavas stored at 11ºC, an indicator of heat-stress injury. Considering the 1-11ºC range, the mean Q10 value was around 3.0; the Q10 value almost duplicated at 11-21ºC range (5.9. At 21-31ºC and 31-41ºC, Q10 was 1.5 and 0.8, respectively. Knowing Q10, respiratory variation and ripening behavior in response to different temperatures, fruit storage and retail conditions can be optimized to reduce quality losses.
Relating structural loading rate to tensing rate for fracture mechanics specimens
Walters, C.L.; Przydatek, J.
2014-01-01
It is vely well-known that fracture toughness depends on loading rate. Higher strain rates can shift the ductile to brittle transition curve to higher temperatures, resulting in a more brittle structure at the same temperature. However, there is little effort to relate the testing rate to the
Suzuki, S.; Itoh, H.
2017-06-01
The measurement of the effective lifetime of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+) in mixtures of nitrogen and small amounts of H2O (10.2 and 103 ppm) was carried out while observing the transient ionization current after turning off the ultraviolet (UV) light illuminating the cathode in a non-self-sustained Townsend discharge region. The transient current was formed by the emitted current sustained by the γ m action of metastable excited molecules {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+), which were produced by the impact of electrons with nitrogen molecules in the gap, and returned to the cathode by diffusion. Then, the collisional quenching rate coefficient of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+) by H2O, the diffusion coefficient of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+), and the reflection coefficient of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+) at the cathode surface were determined from the observed effective lifetime of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+) by an analytical procedure based on solving the diffusion equation. The obtained collisional quenching rate coefficient of {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+,{v}=0) by H2O was (5.7 ± 0.6) × 10-13 cm3 s-1.
RELATIVE DISSOLUTION RATES OF RADIOACTIVE MATERIALS USED AT AWE.
Miller, T J; Bingham, D; Cockerill, R; Waldren, S; Moth, N
2016-09-01
A simple in vitro dissolution test was used to provide a semi-quantitative comparison of the relative dissolution rates of samples of radioactive materials used at Atomic Weapons Establishment in a lung fluid surrogate (Ringer's solution). A wide range of dissolution rates were observed for aged legacy actinides, freshly produced actinide alloys and actinides from waste management operations.
Xin-Fu Bai; Jian-Jun Zhu; Ping Zhang; Yan-Hua Wang; Li-Qun Yang; Lei Zhang
2007-01-01
The response of halophyte arrowleaf saltbush (Atriplex triangularis Willd) plants to a gradient of salt stress were investigated with hydroponically cultured seedlings. Under salt stress, both the Na+ uptake into root xylem and negative pressures in xylem vessels increased with the elevation of salinity (up to 500 mol/m3) in the root environment. However, the increment in negative pressures in root xylem far from matches the decrease in the osmotic potential of the root bathing solutions, even when the osmotic potential of xylem sap is taken into consideration. The total water potential of xylem sap in arrowleaf saltbush roots was close to the osmotic potential of root bathing solutions when the salt stress was low, but a progressively increased gap between the water potential of xylem sap and the osmotic potential of root bathing solutions was observed when the salinity in the root environment was enhanced. The maximum gap was 1.4 MPa at a salinity level of 500 mol/m3 without apparent dehydration of the tested plants. This discrepancy could not be explained with the current theories in plant physiology. The radial reflection coefficient of root in arrowleaf saltbush decreased with the enhanced salt stress was and accompanied by an increase in the Na+ uptake into xylem sap. However, the relative Na+ in xylem exudates based on the corresponding NaCl concentration in the root bathing solutions showed a tendency of decrease. The results showed that the reduction in the radial reflection coefficient of roots in the arrowleaf saltbush did not lead to a mass influx of NaCl into xylem when the radial reflection coefficient of the root was considerably small; and that arrowleaf saltbush could use small xylem pressures to counterbalance the salt stresses, either with the uptake of large amounts of salt, or with the development of xylem pressures dangerously negative. This strategy could be one of the mechanisms behind the high resistance of arrowleaf saltbush plants to salt
Relative rates of homologous and nonhomologous recombination in transfected DNA.
Roth, D B; Wilson, J H
1985-01-01
Both homologous and nonhomologous recombination events occur at high efficiency in DNA molecules transfected into mammalian cells. Both types of recombination occur with similar overall efficiencies, as measured by an endpoint assay, but their relative rates are unknown. In this communication, we measure the relative rates of homologous and nonhomologous recombination in DNA transfected into monkey cells. This measurement is made by using a linear simian virus 40 genome that contains a 131-ba...
Li, Yaqin; Sun, Zhigang; Jiang, Bin; Xie, Daiqian; Dawes, Richard; Guo, Hua
2014-08-28
The kinetics and dynamics of several O + O2 isotope exchange reactions have been investigated on a recently determined accurate global O3 potential energy surface using a time-dependent wave packet method. The agreement between calculated and measured rate coefficients is significantly improved over previous work. More importantly, the experimentally observed negative temperature dependence of the rate coefficients is for the first time rigorously reproduced theoretically. This negative temperature dependence can be attributed to the absence in the new potential energy surface of a submerged "reef" structure, which was present in all previous potential energy surfaces. In addition, contributions of rotational excited states of the diatomic reactant further accentuate the negative temperature dependence.
M. R. McGillen
2007-02-01
Full Text Available The reactivity of aromatic compounds is of great relevance to pure and applied chemical disciplines, yet existing methods for estimating gas-phase rate coefficients for their reactions with free radicals lack accuracy and universality. Here a novel approach is taken, whereby strong relationships between rate coefficients of aromatic hydrocarbons and a Randić-type topological index are investigated, optimized and developed into a method which requires no specialist software or computing power.
Measured gas-phase rate coefficients for the reaction of aromatic hydrocarbons with OH radicals were correlated with a calculated Randić-type index, and optimized by including a term for side chain length. Although this method is exclusively for use with hydrocarbons, it is more diverse than any single existing methodology since it incorporates alkenylbenzenes into correlations, and can be extended towards other radical species such as O(^{3}P (and tentatively NO_{3}, H and Cl. A comparison (with species common to both techniques is made between the topological approach advocated here and a popular approach based on electrophilic subsituent constants, where it compares favourably.
A modelling study was carried out to assess the impact of using estimated rate coefficients as opposed to measured data in an atmospheric model. The difference in model output was negligible for a range of NO_{x} concentrations, which implies that this method has utility in complex chemical models.
Strong relationships (e.g.~for OH, R^{2} = 0.96 between seemingly diverse compounds including benzene, multisubstituted benzenes with saturated, unsaturated, aliphatic and cyclic substitutions and the nonbenzenoid aromatic, azulene suggests that the Randić-type index presented here represents a new and effective way of describing aromatic reactivity, based on a quantitative structure-activity relationship (QSAR.
M. R. McGillen
2007-07-01
Full Text Available The reactivity of aromatic compounds is of great relevance to pure and applied chemical disciplines, yet existing methods for estimating gas-phase rate coefficients for their reactions with free radicals lack accuracy and universality. Here a novel approach is taken, whereby strong relationships between rate coefficients of aromatic hydrocarbons and a Randić-type topological index are investigated, optimized and developed into a method which requires no specialist software or computing power.
Measured gas-phase rate coefficients for the reaction of aromatic hydrocarbons with OH radicals were correlated with a calculated Randić-type index, and optimized by including a term for side chain length. Although this method is exclusively for use with hydrocarbons, it is more diverse than any single existing methodology since it incorporates alkenylbenzenes into correlations, and can be extended towards other radical species such as O(^{3}P (and tentatively NO_{3}, H and Cl. A comparison (with species common to both techniques is made between the topological approach advocated here and a popular approach based on electrophilic subsituent constants, where it compares favourably.
A modelling study was carried out to assess the impact of using estimated rate coefficients as opposed to measured data in an atmospheric model. The difference in model output was negligible for a range of NO_{x} concentrations, which implies that this method has utility in complex chemical models.
Strong relationships (e.g. for OH, R^{2}=0.96 between seemingly diverse compounds including benzene, multisubstituted benzenes with saturated, unsaturated, aliphatic and cyclic substitutions and the nonbenzenoid aromatic, azulene suggests that the Randić-type index presented here represents a new and effective way of describing aromatic reactivity, based on a quantitative structure-activity relationship (QSAR.
Modeling turkey growth with the relative growth rate.
Maruyama, K; Potts, W J; Bacon, W L; Nestor, K E
1998-01-01
Six sigmoidal growth curves and two growth curves derived from a two-phase relative growth rate model were evaluated, using an experimental body-weight data from male and female turkeys of two genetic lines; a fast-growing (F) line and a randombred control (RBC) line from which the F line was developed. When their root mean square error was compared to the root mean square error of the local regression smoother, all sigmoidal growth curves: the logistic, Gompertz, von Bertalanffy, Richards, Weibull, and Morgan-Mercer-Flodin growth curves demonstrated a lack of fit. The primary source of the systematic lack of fit was identified with nonparametric estimates of the relative growth rate (the growth rate as a fraction of the body weight) of 20 turkeys. When the relative growth rate was estimated from the above sigmoidal growth curves, none could accommodate features of the nonparametric estimates of the relative growth rate. Based on the feature of the relative growth rate, two new growth curves were derived from a segmented two-phase model. Both models, in which the relative growth rate decreases in two linear phases with slopes of beta1 and beta2 joined together at time=kappa, gave growth curves that fit the experimental data acceptably. The linear-linear model with the smooth transition rendered better fit over the model with the abrupt transition. When the growth curves of male and female turkeys were compared, beta1, beta2, and kappa were smaller in males. When the F line was compared to the RBC line, beta1 and kappa were smaller and beta2 was closer to zero, indicating that the relative growth rate declined rapidly until about 61 days of age in the F line, while it declined less rapidly until about 71 days of age in the RBC line.
Szu-Wei Lee
2014-03-01
Full Text Available Knowledge of the discrete cosine transform coefficient distribution (DCT-DIST is important for the encoder design. For example, rate control relies on this knowledge to estimate a possible bit rate and then decide proper coding parameters before the actual encoding task is performed. Therefore the rate control performance is fairly dependent on how accurately the DCT-DIST is modelled. The spatial enhancement layer (SL DCT-DIST for H.264 scalable video coding (SVC is studied in this Letter. SL DCT-DIST knowledge is furthermore used to derive a novel rate model. Our results can help design a proper rate control module for the H.264/SVC encoder.
Relative rates of homologous and nonhomologous recombination in transfected DNA.
Roth, D B; Wilson, J H
1985-05-01
Both homologous and nonhomologous recombination events occur at high efficiency in DNA molecules transfected into mammalian cells. Both types of recombination occur with similar overall efficiencies, as measured by an endpoint assay, but their relative rates are unknown. In this communication, we measure the relative rates of homologous and nonhomologous recombination in DNA transfected into monkey cells. This measurement is made by using a linear simian virus 40 genome that contains a 131-base-pair duplication at its termini. Once inside the cell, this molecule must circularize to initiate lytic infection. Circularization can occur either by direct, nonhomologous end-joining or by homologous recombination within the duplicated region. Although the products of the two recombination pathways are different, they are equally infectious. Since homologous and nonhomologous recombination processes are competing for the same substrate, the relative amounts of the products of each pathway should reflect the relative rates of homologous and nonhomologous recombination. Analysis of individual recombinant genomes from 164 plaques indicates that the rate of circularization by nonhomologous recombination is 2- to 3-fold higher than the rate of homologous recombination. The assay system described here may prove to be useful for testing procedures designed to influence the relative rates of homologous and nonhomologous recombination.
基础养老保险缴费率膨胀系数研究%A STUDY OF EXPANSION COEFFICIENT OF ENDOWMENT INSURANCE PAYMENT RATE
穆怀中; 陈洋; 陈曦
2015-01-01
围绕国家提出降低养老保险缴费率的宗旨，本文研究适度降低基础养老保险缴费率的路径，提出养老保险缴费率膨胀系数概念和定量研究数理模型。本文提出，社会保障体制转轨的“成本叠加”、全社会代际交叠的“有限责任”、个人生命周期的“不可预期”是导致养老保险缴费率膨胀的主要原因和内在规律。定量研究发现，现存养老保险缴费率膨胀系数为9．44％，其中覆盖面膨胀系数为5．59％，遵缴率膨胀系数为3．69％，提前退休膨胀系数为0．16％。纵向回归研究发现，覆盖面的膨胀系数弹性为－0．15，遵缴率的膨胀系数弹性为－0．2，提前退休的膨胀系数弹性为0．938。在此基础上，本文提出了相关建议。%In order to reduce the endowment insurance payment rate and moderately reduce the urban employee basic pension payment rate,this paper put forward the concept of endowment insurance payment rate expansion coefficient and set up quantitative mathematical model.This paper concluded the superposi-tion cost of social security system in transition,the limited liability of intergenerational overlapping in the whole society and the unpredictable of personal life cycle were the main reasons and internal rules of en-dowment insurance payment rate’ s expansion.Quantitative study found that the current expansion coeffi-cient of endowment insurance payment rate was 9. 44%and the coverage expansion coefficient was 5. 5 9%, the rate of payment according to system requirements expansion coefficient was 3. 6 9%and the early retire-ment expansion coefficient was 0. 1 6%.Longitudinal regression analysis showed that the coverage expan-sion coefficient elasticity was -0. 1 5 ,the rate of payment according to system requirements expansion co-efficient elasticity was -0. 2,the early retirement expansion coefficient elasticity was 0. 938.Some policy suggestions were provided.
Ramos Fuentes, F; Cardesa García, J J; Arbués Lacadena, J; Espinosa Ruiz-Cabal, J; Pérez González, J
1987-09-01
A prospective study of continual heart rate monitoring is made in 57 normal newborn infants in the first two hours after birth. They were all divided into three groups according to their type of delivery. We have estimated the coefficient of variation, whose value quantifies the heart rate variability, obtained by continual monitoring. It was significantly lower (p less than 0.05) in newborns whose mothers had received anaesthesia during labour than in infants born by non-induced vaginal delivery. These results support the sensitivity of this method in order to assess neonatal cardiac readaptation.
Kandouci Chahr-Eddine; Adjal Yassine
2014-01-01
This present paper deals with a mathematical description of linear axial and torsional vibrations. The normal and tangential stress tensor components produced by axial-torsional deformations and vibrations in the propeller and intermediate shafts, under the influence of propeller-induced static and variable hydrodynamic excitations are also studied. The transfer matrix method related to the constant coefficients of differential equation solutions is used. The advantage of the latter as compared with a well-known method of transfer matrix associated with state vector is the possibility of reducing the number of multiplied matrices when adjacent shaft segments have the same material properties and diameters. The results show that there is no risk of buckling and confirm that the strength of the shaft line depends on the value of the static tangential stresses which is the most important component of the stress tensor.
Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J
2012-01-01
In oocyte vitrification, plunging directly into liquid nitrogen favor film boiling and strong nitrogen vaporization. A survey of literature values of heat transfer coefficients (h) for film boiling of small metal objects with different geometries plunged in liquid nitrogen revealed values between 125 to 1000 W per per square m per K. These h values were used in a numerical simulation of cooling rates of two oocyte vitrification devices (open-pulled straw and Cryotop), plunged in liquid and slush nitrogen conditions. Heat conduction equation with convective boundary condition was considered a linear mathematical problem and was solved using the finite element method applying the variational formulation. COMSOL Multiphysics was used to simulate the cooling process of the systems. Predicted cooling rates for OPS and Cryotop when cooled at -196 degree C (liquid nitrogen) or -207 degree C (average for slush nitrogen) for heat transfer coefficients estimated to be representative of film boiling, indicated lowering the cooling temperature produces only a maximum 10 percent increase in cooling rates; confirming the main benefit of plunging in slush over liquid nitrogen does not arise from their temperature difference. Numerical simulations also demonstrated that a hypothetical four-fold increase in the cooling rate of vitrification devices when plunging in slush nitrogen would be explained by an increase in heat transfer coefficient. This improvement in heat transfer (i.e., high cooling rates) in slush nitrogen is attributed to less or null film boiling when a sample is placed in slush (mixture of liquid and solid nitrogen) because it first melts the solid nitrogen before causing the liquid to boil and form a film.
Oxygen consumption of cycle ergometry is nonlinearly related to work rate and pedal rate.
Londeree, B R; Moffitt-Gerstenberger, J; Padfield, J A; Lottmann, D
1997-06-01
The purpose of the study was to develop an equation to predict the oxygen cost of cycle ergometry. Forty subjects performed an incremental cycle ergometer test on three occasions at 50, 70, or 90 rpm in a counterbalanced order. Work rate was incremented every 5 or 6 min when steady rate values were achieved. To ensure accurate work rates, ergometer resistance was calibrated and flywheel revolutions were electronically measured. Oxygen consumption was measured with a computer interfaced system which provided results every minute. Oxygen consumption (mL.min-1) was the dependent variable, and independent variables were work rate (WR in kgm.min-1), pedal rate (rpm), weight (Kg), and gender (males, 0; females, 1). The following nonlinear equation was selected; VO2 = 0.42.WR1.2 + 0.00061.rpm3 + 6.35.Wt + 0.1136.RPM50.WR-0.10144.RPM90-WR-52-Gender, R2 = 0.9961, Sy.x = 106 mL.min-1, where RPM50: 50 rpm = 1, and RPM90: 90 rpm = 1, else = 0. It was concluded that the oxygen cost of cycle ergometry is nonlinearly related to work rate and pedal rate, linearly related to weight, and that females use less oxygen for a particular work rate.
Higher Export Tax Rates for Copper Related Products
2006-01-01
<正>According to a notice published by the Finance Ministry, the State Council’s Customs Tax Regulation Committee has decided to make some adjustments on the export tax rates for some copper related products. The notice says that in order to control the export products re-
Hoobler, Ray J.; Leone, Stephen R.
1997-01-01
Rate coefficients for the reactions of C2H + HCN yields products and C2H + CH3CN yields products have been measured over the temperature range 262-360 K. These experiments represent an ongoing effort to accurately measure reaction rate coefficients of the ethynyl radical, C2H, relevant to planetary atmospheres such as those of Jupiter and Saturn and its satellite Titan. Laser photolysis of C2H2 is used to produce C2H, and transient infrared laser absorption is employed to measure the decay of C2H to obtain the subsequent reaction rates in a transverse flow cell. Rate constants for the reaction C2H + HCN yields products are found to increase significantly with increasing temperature and are measured to be (3.9-6.2) x 10(exp 13) cm(exp 3) molecules(exp -1) s(exp -1) over the temperature range of 297-360 K. The rate constants for the reaction C2H + CH3CN yields products are also found to increase substantially with increasing temperature and are measured to be (1.0-2.1) x 10(exp -12) cm(exp 3) molecules(exp -1) s(exp -1) over the temperature range of 262-360 K. For the reaction C2H + HCN yields products, ab initio calculations of transition state structures are used to infer that the major products form via an addition/elimination pathway. The measured rate constants for the reaction of C2H + HCN yields products are significantly smaller than values currently employed in photochemical models of Titan, which will affect the HC3N distribution.
Papadimitriou, Vassileios C; Burkholder, James B
2016-08-25
Rate coefficients, k(T), for the OH radical + (E)-(CF3)2CFCH═CHF ((E)-1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene, HFO-1438ezy(E)) gas-phase reaction were measured using pulsed laser photolysis-laser-induced fluorescence (PLP-LIF) between 214 and 380 K and 50 and 450 Torr (He or N2 bath gas) and with a relative rate method at 296 K between 100 and 400 Torr (synthetic air). Over the range of pressures included in this study, no pressure dependence in k(T) was observed. k(296 K) obtained using the two techniques agreed to within ∼3% with (3.26 ± 0.26) × 10(-13) cm(3) molecule(-1) s(-1) (2σ absolute uncertainty) obtained using the PLP-LIF technique. k(T) displayed non-Arrhenius behavior that is reproduced by (7.34 ± 0.30) × 10(-19)T(2) exp[(481 ± 10)/T) cm(3) molecule(-1) s(-1). With respect to OH reactive loss, the atmospheric lifetime of HFO-1438ezy(E) is estimated to be ∼36 days and HFO-1438ezy(E) is considered a very short-lived substance (VSLS) (the actual lifetime will depend on the time and location of the HFO-1438ezy(E) emission). On the basis of the HFO-1438ezy(E) infrared absorption spectrum measured in this work and its estimated lifetime, a radiative efficiency of 0.306 W m(-2) ppb(-1) (well-mixed gas) was calculated and its 100-year time-horizon global warming potential, GWP100, was estimated to be 8.6. CF3CFO, HC(O)F, and CF2O were identified using infrared spectroscopy as stable end products in the oxidation of HFO-1438ezy(E) in the presence of O2. Two additional fluorinated products were observed and theoretical calculations of the infrared spectra of likely degradation products are presented. The photochemical ozone creation potential of HFO-1438ezy(E) was estimated to be ∼2.15.
Variable coefficients EV model in the application of the exchange rate%变系数 EV 模型在人民币汇率中的应用
王雁; 张德生; 王丽辉; 荀新新
2014-01-01
将自适应变系数EV模型在计算机模拟实验的基础上推广到人民币汇率应用中，并利用该模型对人民币美元汇率的月度数据进行拟合预测。实证研究结果表明：自适应变系数EV模型的拟合效果优于FA R模型、A FA R模型的拟合效果，其预测精度也是这几种模型中最优的，可以为研究人民币美元汇率今后的趋势提供帮助。%The adaptive variable coefficients EV model on the basis of computer simulation ex-periment to the RMB exchange rate applications ,the monthly RMB exchange rate is fitted and predicted by using this model .The empirical results show that adaptive variable coeffi-cients EV model was used for data fitting and forecasting precision is superior to the FAR model and AFAR model ,so this model can offer help for the trends of RMB/USD exchange rate .
Urpi, Luca; Rinaldi, Antonio Pio; Rutqvist, Jonny; Cappa, Frédéric; Spiers, Christopher J.
2016-04-01
Poro-elastic stress and effective stress reduction associated with deep underground fluid injection can potentially trigger shear rupture along pre-existing faults. We modeled an idealized CO2 injection scenario, to assess the effects on faults of the first phase of a generic CO2 aquifer storage operation. We used coupled multiphase fluid flow and geomechanical numerical modeling to evaluate the stress and pressure perturbations induced by fluid injection and the response of a nearby normal fault. Slip-rate dependent friction and inertial effects have been aken into account during rupture. Contact elements have been used to take into account the frictional behavior of the rupture plane. We investigated different scenarios of injection rate to induce rupture on the fault, employing various fault rheologies. Published laboratory data on CO2-saturated intact and crushed rock samples, representative of a potential target aquifer, sealing formation and fault gouge, have been used to define a scenario where different fault rheologies apply at different depths. Nucleation of fault rupture takes place at the bottom of the reservoir, in agreement with analytical poro-elastic stress calculations, considering injection-induced reservoir inflation and the tectonic scenario. For the stress state here considered, the first triggered rupture always produces the largest rupture length and slip magnitude, correlated with the fault rheology. Velocity weakening produces larger ruptures and generates larger magnitude seismic events. Heterogeneous faults have been considered including velocity-weakening or velocity strengthening sections inside and below the aquifer, while upper sections being velocity-neutral. Nucleation of rupture in a velocity strengthening section results in a limited rupture extension, both in terms of maximum slip and rupture length. For a heterogeneous fault with nucleation in a velocity-weakening section, the rupture may propagate into the overlying velocity
T. Berkemeier
2017-06-01
Full Text Available We present a Monte Carlo genetic algorithm (MCGA for efficient, automated, and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find and characterize the solution of an optimization problem. It addresses an issue inherent to complex models whose extensive input parameter sets may not be uniquely determined from limited input data. Such ambiguity in the derived parameter values can be reliably detected using this new set of tools, allowing users to design experiments that should be particularly useful for constraining model parameters. We show that the MCGA has been used successfully to constrain parameters such as chemical reaction rate coefficients, diffusion coefficients, and Henry's law solubility coefficients in kinetic models of gas uptake and chemical transformation of aerosol particles as well as multiphase chemistry at the atmosphere–biosphere interface. While this study focuses on the processes outlined above, the MCGA approach should be portable to any numerical process model with similar computational expense and extent of the fitting parameter space.
Berkemeier, Thomas; Ammann, Markus; Krieger, Ulrich K.; Peter, Thomas; Spichtinger, Peter; Pöschl, Ulrich; Shiraiwa, Manabu; Huisman, Andrew J.
2017-06-01
We present a Monte Carlo genetic algorithm (MCGA) for efficient, automated, and unbiased global optimization of model input parameters by simultaneous fitting to multiple experimental data sets. The algorithm was developed to address the inverse modelling problems associated with fitting large sets of model input parameters encountered in state-of-the-art kinetic models for heterogeneous and multiphase atmospheric chemistry. The MCGA approach utilizes a sequence of optimization methods to find and characterize the solution of an optimization problem. It addresses an issue inherent to complex models whose extensive input parameter sets may not be uniquely determined from limited input data. Such ambiguity in the derived parameter values can be reliably detected using this new set of tools, allowing users to design experiments that should be particularly useful for constraining model parameters. We show that the MCGA has been used successfully to constrain parameters such as chemical reaction rate coefficients, diffusion coefficients, and Henry's law solubility coefficients in kinetic models of gas uptake and chemical transformation of aerosol particles as well as multiphase chemistry at the atmosphere-biosphere interface. While this study focuses on the processes outlined above, the MCGA approach should be portable to any numerical process model with similar computational expense and extent of the fitting parameter space.
Altitude Variation of the CO2 (V2)-O Quenching Rate Coefficient in Mesosphere and Lower Thermosphere
Feofilovi, Artem; Kutepov, Alexander; She, Chiao-Yao; Smith, Anne K.; Pesnell, William Dean; Goldberg, Richard A.
2010-01-01
Among the processes governing the energy balance in the mesosphere and lower thermosphere (mlt), the quenching of CO2(N2) vibrational levels by collisions with oxygen atoms plays an important role. However, the k(CO2-O) values measured in the lab and retrieved from atmospheric measurements vary from 1.5 x 10(exp -12) cubic centimeters per second through 9.0 x 10(exp -12) cubic centimeters per second that requires further studying. In this work we used synergistic data from a ground based lidar and a satellite infrared radiometer to estimate K(CO2-O). We used the night- and daytime temperatures between 80 and 110 km measured by the colorado state university narrow-band sodium (Na) lidar located at fort collins, colorado (41N, 255E) as ground truth of the saber/timed nearly simultaneous (plus or minus 10 minutes) and common volume (within plus or minus 1 degree in latitude, plus or minus 2 degrees in longitude) observations. For each altitude in 80-110 km interval we estimate an "optimal" value of K(CO2-O) needed to minimize the discrepancy between the simulated 15 mm CO2 radiance and that measured by the saber/timed instrument. The K(CO2-O) obtained in this way varies in altitude from 3.5 x 10(exp -12) cubic centimeters per second at 80 km to 5.2 x 10(exp -12) cubic centimeters pers second for altitudes above 95 km. We discuss this variation of the rate constant and its impact on temperature retrievals from 15 mm radiance measurements and on the energy budget of mlt.
Heart rate recovery after exercise: relations to heart rate variability and complexity.
Javorka, M; Zila, I; Balhárek, T; Javorka, K
2002-08-01
Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years) during the pre-exercise phase (25 min supine, 5 min standing), during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output) and during the recovery phase (30 min supine). HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.
Heart rate recovery after exercise: relations to heart rate variability and complexity
M. Javorka
2002-08-01
Full Text Available Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years during the pre-exercise phase (25 min supine, 5 min standing, during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output and during the recovery phase (30 min supine. HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.
On the relation between virial coefficients and the close-packing of hard disks and hard spheres.
Maestre, Miguel Angel G; Santos, Andrés; Robles, Miguel; de Haro, Mariano López
2011-02-28
The question of whether the known virial coefficients are enough to determine the packing fraction η(∞) at which the fluid equation of state of a hard-sphere fluid diverges is addressed. It is found that the information derived from the direct Padé approximants to the compressibility factor constructed with the virial coefficients is inconclusive. An alternative approach is proposed which makes use of the same virial coefficients and of the equation of state in a form where the packing fraction is explicitly given as a function of the pressure. The results of this approach both for hard-disk and hard-sphere fluids, which can straightforwardly accommodate higher virial coefficients when available, lends support to the conjecture that η(∞) is equal to the maximum packing fraction corresponding to an ordered crystalline structure.
Tire-Road Friction Coefficients Estimation Base on Slip Rate%基于滑移率的路面附着系数估计
李宣政
2014-01-01
Wheel Tire-Road Friction Coefficients for vehicle active safety control system is very important, such as collision avoidance, adaptive cruise and other auxiliary systems, such as the vehicle's longitudinal security depends on the road surface friction coefficient, such as vehicle status information in real time, accurate estimates. This paper focuses on the vehicle's longitudinal dynamics model, Proposed a level road adhesion coefficient for non-traffic estimation algorithm. The use of tire longitudinal force and slip ratio, the relationship between the road surface friction coefficient and slip rate, by recursive least squares algorithm to achieve a real-time estimation of the road surface friction coefficient. Finally, the use of Matlab/Simulink simulation environment for recursive least squares estimation algorithm was validated simulation results demonstrate the effectiveness of the algorithm.%轮胎要路面附着系数对于车辆主动安全控制系统十分重要，如主动避撞、自适应巡航等车辆纵向安全辅助系统等，依赖于路面附着系数等车辆状态信息实时、准确的估计。本文重点分析了车辆纵向动力学模型，提出了一种针对非水平路况的路面附着系数估计算法。利用轮胎纵向力与滑移率，路面附着系数与滑移率的关系，通过递推最小二乘算法实现了路面附着系数的实时估计。最后利用Matlab/Simulink仿真环境对递推最小二乘估计算法进行了验证，仿真结果验证了算法的有效性。
Bisetti, Fabrizio; El Morsli, Mbark
2014-01-01
The effects of an electric field on the collision rates, energy exchanges and transport properties of electrons in premixed flames are investigated via solutions to the Boltzmann kinetic equation. The case of high electric field strength, which results in high-energy, non-thermal electrons, is analysed in detail at sub-breakdown conditions. The rates of inelastic collisions and the energy exchange between electrons and neutrals in the reaction zone of the flame are characterised quantitatively. The analysis includes attachment, ionisation, impact dissociation, and vibrational and electronic excitation processes. Our results suggest that Townsend breakdown occurs for E/N = 140 Td. Vibrational excitation is the dominant process up to breakdown, despite important rates of electronic excitation of CO, CO2 and N2 as well as impact dissociation of O2 being apparent from 50 Td onwards. Ohmic heating in the reaction zone is found to be negligible (less than 2% of peak heat release rate) up to breakdown field strengths for realistic electron densities equal to 1010 cm-3. The observed trends are largely independent of equivalence ratio. In the non-thermal regime, electron transport coefficients are insensitive to mixture composition and approximately constant across the flame, but are highly dependent on the electric field strength. In the thermal limit, kinetic parameters and transport coefficients vary substantially across the flame due to the spatially inhomogeneous concentration of water vapour. A practical approach for identifying the plasma regime (thermal versus non-thermal) in studies of electric field effects on flames is proposed.
Bisetti, Fabrizio
2014-01-02
The effects of an electric field on the collision rates, energy exchanges and transport properties of electrons in premixed flames are investigated via solutions to the Boltzmann kinetic equation. The case of high electric field strength, which results in high-energy, non-thermal electrons, is analysed in detail at sub-breakdown conditions. The rates of inelastic collisions and the energy exchange between electrons and neutrals in the reaction zone of the flame are characterised quantitatively. The analysis includes attachment, ionisation, impact dissociation, and vibrational and electronic excitation processes. Our results suggest that Townsend breakdown occurs for E/N = 140 Td. Vibrational excitation is the dominant process up to breakdown, despite important rates of electronic excitation of CO, CO2 and N2 as well as impact dissociation of O2 being apparent from 50 Td onwards. Ohmic heating in the reaction zone is found to be negligible (less than 2% of peak heat release rate) up to breakdown field strengths for realistic electron densities equal to 1010 cm-3. The observed trends are largely independent of equivalence ratio. In the non-thermal regime, electron transport coefficients are insensitive to mixture composition and approximately constant across the flame, but are highly dependent on the electric field strength. In the thermal limit, kinetic parameters and transport coefficients vary substantially across the flame due to the spatially inhomogeneous concentration of water vapour. A practical approach for identifying the plasma regime (thermal versus non-thermal) in studies of electric field effects on flames is proposed. © 2014 Taylor & Francis.
Engineering aspects of rate-related processes in food manufacturing.
Adachi, Shuji
2015-01-01
Many rate-related phenomena occur in food manufacturing processes. This review addresses four of them, all of which are topics that the author has studied in order to design food manufacturing processes that are favorable from the standpoint of food engineering. They include chromatographic separation through continuous separation with a simulated moving adsorber, lipid oxidation kinetics in emulsions and microencapsulated systems, kinetic analysis and extraction in subcritical water, and water migration in pasta.
Phonation related rate coding and recruitment in the genioglossus muscle
Shumway, K.R.; Porfirio, D.J.; Bailey, E.F.
2015-01-01
Motor unit (MU) recruitment was assessed in two muscles with similar muscle fiber type compositions and that participate in skilled movements: the tongue muscle, genioglossus (GG) and the hand muscle, first dorsal interosseous (FDI). Our primary objectives were to determine in the framework of a voluntary movement whether muscle force is regulated in tongue as it is in limb i.e., via processes of rate coding and recruitment. Recruitment in the two muscles was assessed within each subject in the context of ramp force (FDI) and in the tongue (GG) during vowel production and specifically, in the context of ramp increases in loudness, and subsequently expressed relative to the maximal. The principle findings of the study are that the general rules of recruitment and rate coding hold true for both GG and FDI and second, that average firing rates, firing rates at recruitment and peak firing rates in GG are significantly higher than for FDI (P role as (prime) mover and hydrostatic support element. PMID:25899868
Gray, Heewon Lee; Burgermaster, Marissa; Tipton, Elizabeth; Contento, Isobel R; Koch, Pamela A; Di Noia, Jennifer
2016-04-01
Sample size and statistical power calculation should consider clustering effects when schools are the unit of randomization in intervention studies. The objective of the current study was to investigate how student outcomes are clustered within schools in an obesity prevention trial. Baseline data from the Food, Health & Choices project were used. Participants were 9- to 13-year-old students enrolled in 20 New York City public schools (n= 1,387). Body mass index (BMI) was calculated based on measures of height and weight, and body fat percentage was measured with a Tanita® body composition analyzer (Model SC-331s). Energy balance-related behaviors were self-reported with a frequency questionnaire. To examine the cluster effects, intraclass correlation coefficients (ICCs) were calculated as school variance over total variance for outcome variables. School-level covariates, percentage students eligible for free and reduced-price lunch, percentage Black or Hispanic, and English language learners were added in the model to examine ICC changes. The ICCs for obesity indicators are: .026 for BMI-percentile, .031 for BMIz-score, .035 for percentage of overweight students, .037 for body fat percentage, and .041 for absolute BMI. The ICC range for the six energy balance-related behaviors are .008 to .044 for fruit and vegetables, .013 to .055 for physical activity, .031 to .052 for recreational screen time, .013 to .091 for sweetened beverages, .033 to .121 for processed packaged snacks, and .020 to .083 for fast food. When school-level covariates were included in the model, ICC changes varied from -95% to 85%. This is the first study reporting ICCs for obesity-related anthropometric and behavioral outcomes among New York City public schools. The results of the study may aid sample size estimation for future school-based cluster randomized controlled trials in similar urban setting and population. Additionally, identifying school-level covariates that can reduce cluster
G SRINIVASULU; B RAJAKUMAR
2016-06-01
The kinetics of the reaction between pinonaldehyde C10H16O2 and Cl atom were studied usinghigh level ab initio G3(MP2) and DFT based MPWB1K/6-31+G(d) and MPW1K/6-31+G(d) levels of theoriescoupled with Conventional Transition State Theory in the temperature range between 200 and 400 K. Thenegative temperature dependent rate expression for the title reaction obtained with Wigner’s and Eckart’s symmetricaltunneling corrections are k(T)=(5.1 ± 0.56) × 10−19T2.35exp[(2098 ± 2)/T] cm3 molecule-1 s-1, and k(T)=(0.92 ± 0.18) × 10-19T2.60exp[(2204 ± 4)/T] cm3 molecule-1 s-1, respectively, at G3(MP2)//MPWB1Kmethod. The H abstraction reaction from the –CHO group was found to be the most dominant reaction channelamong all the possible reaction pathways and its corresponding rate coefficient at 300 K is kEckart’s unsymmetrical= 3.86 ×10-10 cm3 molecule-1 s-1. Whereas the channel with immediate lower activation energy is the H-abstraction from –CH- group (Tertiary H-abstraction site, Cg). The rate coefficient for this channel is kCg(Eckart’s unsymmetrical) = 1.83 ×10-15 cm3 molecule-1 s-1 which is smaller than the dominant channel byfive orders of magnitude. The atmospherically relevant parameters such as lifetimes were computed in thisinvestigation of its reaction with Cl atom.
Relative survival rates after alternative therapies for uveal melanoma
Seddon, J.M.; Gragoudas, E.S.; Egan, K.M.; Glynn, R.J.; Howard, S.; Fante, R.G.; Albert, D.M. (Massachusetts Eye and Ear Infirmary, Boston (USA))
1990-06-01
Survival in a group of 556 patients with uveal melanoma treated by proton beam irradiation with a median follow-up of 5.3 years was compared with that of 238 patients enucleated during the same 10-year period as irradiated patients (July 1975 to December 1984) with a median follow-up of 8.8 years, and 257 patients enucleated during the preceding 10 years (January 1965 to June 1975) with a median follow-up of 17.0 years. Adjustments were made for known prognostic factors including age, tumor location, tumor height, and clinical estimate of tumor diameter (for enucleated patients this was estimated in a regression equation relating histologic to clinical measurement). The overall rate ratio for all cause mortality was 1.2 (95% confidence interval, 0.9-1.6) for the concurrent enucleation series versus proton beam, and 1.6 (95% confidence interval, 1.2-2.1) for the earlier enucleation series versus proton beam. Relative rates of metastatic death, cancer death, and all cause mortality comparing alternative treatments were found to vary with time after treatment. Interval-specific rate ratios were evaluated using proportional hazards models fitted to separate time intervals after treatment. For all three outcomes, rate ratios were over two and statistically significant for the first 2 years after treatment and closer to one and nonsignificant after year 6 comparing the two enucleation groups with proton beam. Results suggest that treatment choice has little overall influence on survival in patients with uveal melanoma.
Collisional rate coefficients of SiH(X2 Π) open-shell molecule induced by its collision with He(1 S)
Tchakoua, T.; Nsangou, M.; Motapon, O.
2017-01-01
New adiabatic potential energy surfaces (PESs) for 2A‧ and 2A″ states of SiH(X2 Π)-He(1 S) complex have been calculated at the restricted coupled cluster level of theory including single, double and triple excitation [RCCSD(T)]. The RKHS method was used for the analytic fit of these PESs. The resulting PESs were employed later in the close-coupling approach for the computation of the inelastic integral cross sections which take into account the fine-structure of the SiH radical. Scattering calculations, are done on a grid of collision energies large enough to ensure converged state-to-state rate coefficients for the temperature ranging from 8 K up to 300 K.
Chicheportiche, Alexandre; Benhenni, Malika; Yousfi, Mohammed, E-mail: yousfi@laplace.univ-tlse.fr [Laboratoire Plasma et Conversion d’Energie, LAPLACE and UMR5213 du CNRS, Université de Toulouse, UPS, 118 route de Narbonne, 31062 Toulouse Cedex (France); Stachoň, Martin; Kalus, René, E-mail: rene.kalus@vsb.cz [Center of Excellence IT4Innovations and Department of Applied Mathematics, VSB - Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava (Czech Republic); Gadéa, Florent Xavier [Laboratoire de Chimie et de Physique Quantiques, IRSAMC and UMR5626 du CNRS, Université de Toulouse, UPS, 118 route de Narbonne, 31062 Toulouse Cedex (France)
2014-10-07
Momentum-transfer collision cross-sections and integral collision cross-sections for the collision-induced dissociation are calculated for collisions of ionized argon dimers with argon atoms using a nonadiabatic semiclassical method with the electronic Hamiltonian calculated on the fly via a diatomics-in-molecules semiempirical model as well as inverse-method modeling based on simple isotropic rigid-core potential. The collision cross-sections are then used in an optimized Monte Carlo code for evaluations of the Ar{sub 2}{sup +} mobility in argon gas, longitudinal diffusion coefficient, and collision-induced dissociation rates. A thorough comparison of various theoretical calculations as well as with available experimental data on the Ar{sub 2}{sup +} mobility and collision cross-sections is performed. Good agreement is found between both theoretical approaches and the experiment. Analysis of the role of inelastic processes in Ar{sub 2}{sup +}/Ar collisions is also provided.
Modified Biserial Correlation Coefficients.
Kraemer, Helena Chmura
1981-01-01
Asymptotic distribution theory of Brogden's form of biserial correlation coefficient is derived and large sample estimates of its standard error obtained. Its relative efficiency to the biserial correlation coefficient is examined. Recommendations for choice of estimator of biserial correlation are presented. (Author/JKS)
Constitutive Relation of Yunjialing Anthracite Under Medium Strain Rate
GAO Wen-jiao; SHAN Ren-liang; WANG Gong-cheng; CHENG Rui-qiang
2007-01-01
By means of the split Hopkinson pressure bar (SHPB) testing system, this paper presents a dynamic constitutive relation of anthracite at a strain rate of ε =5-85s-1. Generally, the dynamic stress-strain curve for this kind of anthracite under uni-axial compression has the following four stages: a non-linear loading stage, a plastic yielding stage, a strain-strengthening stage and an unloading breakage stage. Correspondingly, the initial elastic modulus Eb, the yielding strength σs and the ultimate strength σb increase along with an increasing strain rate. The time-dependent elasticity was identified when we analyzed the mechanical properties of anthracite. Based on characteristics of measured dynamic stress-strain curves and an analysis of existing rock dynamic constitutive models, as well as a preparatory simulation, a new visco-elastic damage model has been introduced in this paper. A linear spring is put parallel to two Maxwell units with different relaxation times to express two distinct plastic flows. The damage D is equal to [Eb- E(εi)]/Eb, where Eb is the beginning modulus and the E(εi) is the slope of a connected line between the origin point and any other point on a tested stress-strain curve. In the new constitutive model, one Maxwell unit with low relaxation time (ψ)1 is used to describe the response of anthracite to a low strain rate, while the other, with a high relaxation time (ψ)2 describes the response of anthracite to a high strain rate. Simulated stress-strain curves from the new model are consistent with the measured curves.
Radar Estimation of Intense Rainfall Rates through Adaptive Calibration of the Z-R Relation
Andrea Libertino
2015-10-01
Full Text Available Rainfall intensity estimation from weather radar is still significantly uncertain, due to local anomalies, radar beam attenuation, inappropriate calibration of the radar reflectivity factor (Z to rainfall rate (R relationship, and sampling errors. The aim of this work is to revise the use of the power-law equation commonly adopted to relate radar reflectivity and rainfall rate to increase the estimation quality in the presence of intense rainfall rates. We introduce a quasi real-time procedure for an adaptive in space and time estimation of the Z-R relation. The procedure is applied in a comprehensive case study, which includes 16 severe rainfall events in the north-west of Italy. The study demonstrates that the technique outperforms the classical estimation methods for most of the analysed events. The determination coefficient improves by up to 30% and the bias values for stratiform events decreases by up to 80% of the values obtained with the classical, non-adaptive, Z-R relations. The proposed procedure therefore shows significant potential for operational uses.
Human heart rate variability relation is unchanged during motion sickness
Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.
1998-01-01
In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.
A relation between screening masses and real-time rates
Brandt, B.B. [Institute for Theoretical Physics, University of Regensburg,93040 Regensburg (Germany); Francis, A. [PRISMA Cluster of Excellence, Institute for Nuclear Physics,Helmholtz Institute Mainz, Johannes Gutenberg University Mainz,55099 Mainz (Germany); Laine, M. [Institute for Theoretical Physics, Albert Einstein Center, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); Meyer, H.B. [PRISMA Cluster of Excellence, Institute for Nuclear Physics,Helmholtz Institute Mainz, Johannes Gutenberg University Mainz,55099 Mainz (Germany)
2014-05-23
Thermal screening masses related to the conserved vector current are determined for the case that the current carries a non-zero Matsubara frequency, both in a weak-coupling approach and through lattice QCD. We point out that such screening masses are sensitive to the same infrared physics as light-cone real-time rates. In particular, on the perturbative side, the inhomogeneous Schrödinger equation determining screening correlators is shown to have the same general form as the equation implementing LPM resummation for the soft-dilepton and photon production rates from a hot QCD plasma. The static potential appearing in the equation is identical to that whose soft part has been determined up to NLO and on the lattice in the context of jet quenching. Numerical results based on this potential suggest that screening masses overshoot the free results (multiples of 2πT) more strongly than at zero Matsubara frequency. Four-dimensional lattice simulations in two-flavour QCD at temperatures of 250 and 340 MeV confirm the non-static screening masses at the 10% level. Overall our results lend support to studies of jet quenching based on the same potential at T≳250 MeV.
Kanaya, Y.; Taketani, F.; Irie, H.; Komazaki, Y.; Takashima, H.; Xiaole, P.; Takami, A.; Wang, Z.
2011-12-01
We employed an integrating nephelometer equipped with a humidifier (where the relative humidity (RH) was scanned between 40 and 90%) to measure the aerosol scattering coefficients and their dependence on RH at Fukue Island (32.75N, 128.68E), west of Japan, in May 2009 and at Rudong, Jiangsu, China (32.26N, 121.37E) in May/June 2010, aiming at better characterization of optical properties of the regional-scale aerosol pollution over East Asia. The two coastal sites are located east and west of the East China Sea and are separated by about 700 km. The observed scattering coefficients are normalized by the concurrently measured PM2.5 mass concentrations and thereby behaviors of the mass scattering coefficients are discussed. At Fukue, the mass scattering coefficients under the ambient RH conditions were >1.5 times higher than those observed under the dry condition (RH = 40%), suggesting that the RH effect was crucial in determining optical properties under ambient conditions. The coefficients under the ambient RH conditions, rather than the dry values, agreed better with the extinction coefficients determined by MAX-DOAS (Multi-Axis Differential Optical Absorption Spectroscopy) technique based on remote measurements of O4 optical depths. The single-scattering albedo (SSA), estimated in combination to the absorption coefficients determined by a MAAP (Multi-Angle Absorption Photometer) instrument, had similar average values (~0.95) at the two sites. The SSA values at the two sites were commonly lowered (to below 0.90) when the air traveled from the North China Plain region. At Fukue, the RH dependence was found to be weakened when the organics/sulfate ratio increased (as observed by an Aerodyne Aerosol Mass Spectrometer), while such influence of chemical composition was less clear at Rudong, possibly masked by large temporal variations in the particle size distributions.
Scaling Relations of Galactic Winds with Star Formation Rate
Tanner, Ryan; Cecil, Gerald; Heitsch, Fabian
2017-01-01
The galactic scale outflows generated by nuclear starbursts consist of a multiphase medium where each phase has a distinct velocity depending on the characteristics of the starburst. Using synthetic absorption lines generated from 3D hydrodynamical simulations we probe the outflow velocity of the hot, warm, and neutral gas entrained in a galactic wind. By varying the star formation rate (SFR) in our simulations, we find no correlation between the outflow velocity of the hot gas with the SFR, but we do find a correlation between the outflow velocity of both warm and neutral gas with the SFR. The scaling relation between outflow velocity and SFR only holds for low SFR until the scaling relation abruptly flattens at a SFR determined by the mass loading of the starburst. The outflow velocity of the hot gas only depends on the mass loading of the starburst and not the SFR. For low SFRs the difference between the velocity of cold gas, as measured by absorption lines of neutral or low ionized gas, may be 5-7 times lower than the velocity of the hot, highly ionized gas. The difference in velocity between the cold and hot gas for higher SFRs depends on the mass loading factor of the starburst. Thus the measured velocities of neutral or low ionized gas cannot be used to estimate the outflow velocity of the hot gas without determining the mass loading of the starburst.
Azat Akbal
2016-01-01
Full Text Available Correlation between the antioxidant capacity and silver nanoparticle formation rates of pomegranate (Punica granatum, quince (Cydonia oblonga, chestnut (Castanea sativa, fig (Ficus carica, walnut (Juglans cinerea, black mulberry (Morus nigra, and white mulberry (Morus alba leaf extracts is investigated at a fixed illumination. Silver nanoparticles formed in all plant leaf extracts possess round shapes with average particle size of 15 to 25 nm, whereas corresponding surface plasmon resonance peak wavelengths vary between 422 nm and 451 nm. Cupric reducing antioxidant capacity technique is used as a reference method to determine total antioxidant capacity of the plant leaf extracts. Integrated absorbance over the plasmon resonance peaks exhibits better linear relation with antioxidant capacities of various plant leaf extracts compared to peak absorbance values, with correlation coefficient values of 0.9333 and 0.7221, respectively.
Influence of the relative deformation rate on tube processing by ultrasonic vibration drawing
Susan, M.
2004-04-01
Full Text Available After a brief review of the "friction reversion mechanism" during ultrasonic vibration drawing of tubes (UVD, the paper introduces a method to determine the drawing force based on the theorem of total consumed power, in the case of tube processing. The experiments performed on tubes made from 10TiNiCr180 (AISI321 austenitic stainless steel confirm the superiority of UVD technology regarding the diminution of the drawing force, the increase of the plasticity and the improvement of the safety coefficient, tendencies that are enhanced with the decrease of the relative drawing rate. The best results were obtained for the relative drawing rate of 0.12 for which the drawing force decreased with 33 %, plasticity increased with 9 % and safety coefficient with 22 %, as compared to CT.
Después de un breve resumen del mecanismo de reversión de la fricción al estirado por vibraciones ultrasonoras (EVU, el trabajo propone un método para calcular la fuerza de estirado en base al teorema de la potencia total consumida, en el caso particular de la elaboración de tubos. Los experimentos realizados con tubos de acero inoxidable austenítico 10TiNiCr180 (AISI321 demuestran la superioridad de la tecnología EVU sobre la tecnología clásica (TC, en lo concerniente a la reducción de la fuerza de estirado, el incremento de la plasticidad y la mejora del coeficiente de seguridad, tendencias que se acentúan al diminuirse la velocidad relativa de estirado. Los mejores resultados se han obtenido en el caso de la velocidad relativa de 0,12, para la cual la fuerza de estirado se redujo, aproximadamente, un 33 %; la plasticidad se incrementó en el 9 %; y el coeficiente de seguridad aumentó un 22 % frente a la TC.
Morales, Sébastien B; Le Picard, Sébastien D; Canosa, André; Sims, Ian R
2010-01-01
The kinetics of the reactions of cyano radical, CN (X2sigma+) with three hydrocarbons, propane (CH3CH2CH3), propene (CH3CH=CH2) and 1-butyne (CH[triple band]CCH2CH3) have been studied over the temperature range of 23-298 K using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in Uniform Supersonic Flow) apparatus combined with the pulsed laser photolysis-laser induced fluorescence technique. These reactions are of interest for the cold atmospheres of Titan, Pluto and Triton, as they might participate in the formation of nitrogen and carbon bearing molecules, including nitriles, that are thought to play an important role in the formation of hazes and biological molecules. All three reactions are rapid with rate coefficients in excess of 10(-10) cm3 molecule(-1) s(-1) at the lowest temperatures of this study and show behaviour characteristic of barrierless reactions. Temperature dependences, different for each reaction, are compared to those used in the most recent photochemical models of Titan's atmosphere.
Anigbogu, Chikodi N; Williams, Daniel T; Brown, David R; Silcox, Dennis L; Speakman, Richard O; Brown, Laura C; Karounos, Dennis G; Randall, David C
2011-01-01
Circadian changes in cardiovascular function during the progression of diabetes mellitus in the diabetes prone rat (BBDP) (n = 8) were studied. Age-matched diabetes-resistant rats (BBDR) served as controls. BP was recorded via telemetry in contiguous 4 hr time periods over 24 hours starting with 12 midnight to 4 am as period zero (P0). Prior to onset of diabetes BP was high at P0, peaked at P2, and then fell again at P3; BP and heart rate (HR) then increased gradually at P4 and leveled off at P5, thereby exhibiting a bipodal rhythm. These patterns changed during long-term diabetes. The cross-correlation coefficient of BP and HR was not significantly different across groups at onset, but it fell significantly at 9 months of duration of diabetes (BBDP: 0.39 ± 0.06; BBDR: 0.65 ± 0.03; P < .05). These results show that changes in circadian cardiovascular rhythms in diabetes mellitus became significant at the late stage of the disease.
Relative rates and features of musculoskeletal complications in adult sicklers.
Bahebeck, Jean; Atangana, Réné; Techa, André; Monny-Lobe, Marcel; Sosso, Maurice; Hoffmeyer, Pierre
2004-04-01
The purpose of this study was to prospectively look for the relative rates and features of musculoskeletal complications in a sample of adult homozygous SS sicklers in Yaoundé. During a 3-year period, known homozygous SS sicklers aged sixteen years or more, with suspicion or evidence of locomotor system disease, including leg ulcer, were consecutively investigated through complete medical history, clinical examination, full blood count, C-reactive protein, standard radiographs of the area of complaint, and, when necessary, CT scan and pus analysis. Those patients with no definite diagnosis were excluded. The study group comprised 84 patients aged 16 to 51 years (mean age: 22 years), with a male/female ratio of 0.75. Four of them (4.5%) were older than 40 years. Thirty five (41.6%) presented a total of 50 lesions of aseptic osteonecrosis, which were located in the hips in 25 cases (50%), in the lumbar spine in 20 cases (40%), in the humeral head in four cases (10%) and in the talar body in one case. The hip necrosis was grade I in 6 cases, grade II in four, grade III in 11 and terminal in four. Multiple sites of necrosis were observed in six patients. Nineteen (22.6%) of the sicklers came on with 36 malleolar ulcers, more frequently in males (sex ratio: 5/1) and 28 (78%) located on the medial side. Fifteen sites of osteomyelitis were noted in 14 patients (17.8%) and septic arthritis in six (7%). Less frequent complications were impingement syndrome, gout osteoarthropathy, stress fracture, subtalar fusion, knee osteoarthritis, tendonitis of the anterior tibialis, and recurrent dislocation of the patella. All patients were managed conventionally, except for advanced aseptic necrosis in which the indication for arthroplasty was delayed till the terminal stage. As suggested by another recent report from Senegal, efforts should be made to improve the life expectancy of sicklers in Sub-Saharan African countries, by acting on education, social and medical care
Heart rate recovery after exercise: relations to heart rate variability and complexity
Javorka M; Zila I.; Balhárek T.; Javorka K
2002-01-01
Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. He...
Heart rate recovery after exercise: relations to heart rate variability and complexity
Javorka M.; Zila I.; Balhárek T.; Javorka K
2002-01-01
Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. He...
Age related reference ranges for respiration rate and heart rate from 4 to 16 years
Wallis, L; Healy, M.; Undy, M; Maconochie, I
2005-01-01
Background: Clinical vital signs in children (temperature, heart rate, respiration rate, and blood pressure) are an integral part of clinical assessment of degree of illness or normality. Despite this, only blood pressure and temperature have a reliable evidence base. The accepted ranges of heart and respiration rate vary widely.
Ng, Maggie; Mok, Daniel K W; Lee, Edmond P F; Dyke, John M
2015-03-21
The reaction between atomic chlorine (Cl) and methyl nitrate (CH3ONO2) is significant in the atmosphere, as Cl is a key oxidant, especially in the marine boundary layer, and alkyl nitrates are important nitrogen-containing organic compounds, which are temporary reservoirs of the reactive nitrogen oxides NO, NO2 and NO3 (NOx). Four reaction channels HCl + CH2ONO2, CH3OCl + NO2, CH3Cl + NO3 and CH3O + ClNO2 were considered. The major channel is found to be the H abstraction channel, to give the products HCl + CH2ONO2. For all channels, geometry optimization and frequency calculations were carried out at the M06-2X/6-31+G** level, while relative electronic energies were improved to the UCCSD(T*)-F12/CBS level. The reaction barrier (ΔE(‡)0K) and reaction enthalpy (ΔH(RX)298K) of the H abstraction channel were computed to be 0.61 and -2.30 kcal mol(-1), respectively, at the UCCSD(T*)-F12/CBS//M06-2X/6-31+G** level. Reaction barriers (ΔE(‡)0K) for the other channels are more positive and these pathways do not contribute to the overall reaction rate coefficient in the temperature range considered (200-400 K). Rate coefficients were calculated for the H-abstraction channel at various levels of variational transition state theory (VTST) including tunnelling. Recommended ICVT/SCT rate coefficients in the temperature range 200-400 K are presented for the first time for this reaction. The values obtained in the 200-300 K region are particularly important as they will be valuable for atmospheric modelling calculations involving reactions with methyl nitrate. The implications of the results to atmospheric chemistry are discussed. Also, the enthalpies of formation, ΔHf,298K, of CH3ONO2 and CH2ONO2 were computed to be -29.7 and 19.3 kcal mol(-1), respectively, at the UCCSD(T*)-F12/CBS level.
Unemployment Rate, Smoking in China: Are They Related?
Qing Wang
2016-01-01
Full Text Available Background: Studies on the relationship between unemployment rate and smoking have yielded mixed results. The issue in China has not been studied. This study aims to examine the influence of unemployment rate on smoking in China. Methods: Logit model and two-stage least squares (2SLS estimation were used to estimate the effects. Estimations were done for 4585 individual over 45 using data from China Health and Retirement Longitudinal Study conducted in Zhejiang and Gansu provinces in 2008 and 2012. Results: A percent increase in the unemployment rate resulted in the increase in the likelihood of smoking by a combined 9.1 percent for those who smoked including a 2.9% increase for those who smoked 1–10 cigarettes per day; a 2.8% increase for those who smoked 11–20 cigarettes per day; and a 3.4% increase for those who smoked 20 cigarettes or more per day. The effects were stronger for those who were employed. Non-drinkers were more likely to engage in smoking with increased unemployment rate. 2SLS estimation revealed the same association. Conclusions: The unemployment rate was positively associated with smoking behavior. Smoking control and intervention strategies should focus on both the individual′s characteristics and the physical environment in which unemployment rate tend to rise.
Unemployment Rate, Smoking in China: Are They Related?
Wang, Qing; Shen, Jay J; Cochran, Chris
2016-01-08
Studies on the relationship between unemployment rate and smoking have yielded mixed results. The issue in China has not been studied. This study aims to examine the influence of unemployment rate on smoking in China. Logit model and two-stage least squares (2SLS) estimation were used to estimate the effects. Estimations were done for 4585 individual over 45 using data from China Health and Retirement Longitudinal Study conducted in Zhejiang and Gansu provinces in 2008 and 2012. A percent increase in the unemployment rate resulted in the increase in the likelihood of smoking by a combined 9.1 percent for those who smoked including a 2.9% increase for those who smoked 1-10 cigarettes per day; a 2.8% increase for those who smoked 11-20 cigarettes per day; and a 3.4% increase for those who smoked 20 cigarettes or more per day. The effects were stronger for those who were employed. Non-drinkers were more likely to engage in smoking with increased unemployment rate. 2SLS estimation revealed the same association. The unemployment rate was positively associated with smoking behavior. Smoking control and intervention strategies should focus on both the individual's characteristics and the physical environment in which unemployment rate tend to rise.
Rodbard, David
2012-10-01
We describe a new approach to estimate the risks of hypo- and hyperglycemia based on the mean and SD of the glucose distribution using optional transformations of the glucose scale to achieve a more nearly symmetrical and Gaussian distribution, if necessary. We examine the correlation of risks of hypo- and hyperglycemia calculated using different glucose thresholds and the relationships of these risks to the mean glucose, SD, and percentage coefficient of variation (%CV). Using representative continuous glucose monitoring datasets, one can predict the risk of glucose values above or below any arbitrary threshold if the glucose distribution is Gaussian or can be transformed to be Gaussian. Symmetry and gaussianness can be tested objectively and used to optimize the transformation. The method performs well with excellent correlation of predicted and observed risks of hypo- or hyperglycemia for individual subjects by time of day or for a specified range of dates. One can compare observed and calculated risks of hypo- and hyperglycemia for a series of thresholds considering their uncertainties. Thresholds such as 80 mg/dL can be used as surrogates for thresholds such as 50 mg/dL. We observe a high correlation of risk of hypoglycemia with %CV and illustrate the theoretical basis for that relationship. One can estimate the historical risks of hypo- and hyperglycemia by time of day, date, day of the week, or range of dates, using any specified thresholds. Risks of hypoglycemia with one threshold (e.g., 80 mg/dL) can be used as an effective surrogate marker for hypoglycemia at other thresholds (e.g., 50 mg/dL). These estimates of risk can be useful in research studies and in the clinical care of patients with diabetes.
Mobley, Joel; Mack, Richard A; Gladden, Joseph R; Mantena, P Raju
2009-07-01
Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths investigated and up (>0.2 mm). Using Kramers-Kronig relations, the attenuation and dispersion data were found to be consistent with a power-law attenuation model with a range of exponents from y=1.12 to y=1.19 over the measurement bandwidth. The attenuation coefficients of the respective samples are found to decrease with increasing MWCNT content and a similar trend holds also for the dispersion. In contrast, the mean phase velocities for the samples rise with increasing MWCNT content indicating an increase in the mechanical moduli.
Study on the Friction Coefficient in Grinding
无
2002-01-01
The friction between the abrasive grains and workpi ec e is a crutial factor determining the main grinding output. Few studies have bee n carried out investigating the values of the friction coefficient in grinding, due to the difficulty of direct measurement. In this paper, a mathematical model of the friction coefficient in grinding has been established with the aid of a new grinding parameter C ge, which has close relations to wheel wear rate Z s, metal removal rate Z w, specific energy u and gr...
Divergence of conserved non-coding sequences: rate estimates and relative rate tests.
Wagner, Günter P; Fried, Claudia; Prohaska, Sonja J; Stadler, Peter F
2004-11-01
In many eukaryotic genomes only a small fraction of the DNA codes for proteins, but the non-protein coding DNA harbors important genetic elements directing the development and the physiology of the organisms, like promoters, enhancers, insulators, and micro-RNA genes. The molecular evolution of these genetic elements is difficult to study because their functional significance is hard to deduce from sequence information alone. Here we propose an approach to the study of the rate of evolution of functional non-coding sequences at a macro-evolutionary scale. We identify functionally important non-coding sequences as Conserved Non-Coding Nucleotide (CNCN) sequences from the comparison of two outgroup species. The CNCN sequences so identified are then compared to their homologous sequences in a pair of ingroup species, and we monitor the degree of modification these sequences suffered in the two ingroup lineages. We propose a method to test for rate differences in the modification of CNCN sequences among the two ingroup lineages, as well as a method to estimate their rate of modification. We apply this method to the full sequences of the HoxA clusters from six gnathostome species: a shark, Heterodontus francisci; a basal ray finned fish, Polypterus senegalus; the amphibian, Xenopus tropicalis; as well as three mammalian species, human, rat and mouse. The results show that the evolutionary rate of CNCN sequences is not distinguishable among the three mammalian lineages, while the Xenopus lineage has a significantly increased rate of evolution. Furthermore the estimates of the rate parameters suggest that in the stem lineage of mammals the rate of CNCN sequence evolution was more than twice the rate observed within the placental amniotes clade, suggesting a high rate of evolution of cis-regulatory elements during the origin of amniotes and mammals. We conclude that the proposed methods can be used for testing hypotheses about the rate and pattern of evolution of putative
The relation between starch digestion rate and amino acid level for broiler chickens
Weurding, R.E.; Enting, H.; Verstegen, M.W.A.
2003-01-01
Digestion coefficients of nutrients give information about the amount of nutrients available to the animal but not about the rate or site of absorption. Gradual digestion of starch may have an amino acid sparing effect and therefore enhance growth efficiency of broiler chickens. A growth trial was
CREME96 and Related Error Rate Prediction Methods
Adams, James H., Jr.
2012-01-01
Predicting the rate of occurrence of single event effects (SEEs) in space requires knowledge of the radiation environment and the response of electronic devices to that environment. Several analytical models have been developed over the past 36 years to predict SEE rates. The first error rate calculations were performed by Binder, Smith and Holman. Bradford and Pickel and Blandford, in their CRIER (Cosmic-Ray-Induced-Error-Rate) analysis code introduced the basic Rectangular ParallelePiped (RPP) method for error rate calculations. For the radiation environment at the part, both made use of the Cosmic Ray LET (Linear Energy Transfer) spectra calculated by Heinrich for various absorber Depths. A more detailed model for the space radiation environment within spacecraft was developed by Adams and co-workers. This model, together with a reformulation of the RPP method published by Pickel and Blandford, was used to create the CR ME (Cosmic Ray Effects on Micro-Electronics) code. About the same time Shapiro wrote the CRUP (Cosmic Ray Upset Program) based on the RPP method published by Bradford. It was the first code to specifically take into account charge collection from outside the depletion region due to deformation of the electric field caused by the incident cosmic ray. Other early rate prediction methods and codes include the Single Event Figure of Merit, NOVICE, the Space Radiation code and the effective flux method of Binder which is the basis of the SEFA (Scott Effective Flux Approximation) model. By the early 1990s it was becoming clear that CREME and the other early models needed Revision. This revision, CREME96, was completed and released as a WWW-based tool, one of the first of its kind. The revisions in CREME96 included improved environmental models and improved models for calculating single event effects. The need for a revision of CREME also stimulated the development of the CHIME (CRRES/SPACERAD Heavy Ion Model of the Environment) and MACREE (Modeling and
Are age-related trends in suicide rates associated with life expectancy and socio-economic factors?
Shah, Ajit
2009-01-01
Background. A recent cross-national study reported that suicide rates increased, decreased or remained unchanged with increasing age in individual countries. The relationship between age-related trends in suicide rates and child mortality rates, life expectancy and socio-economic factors was examined. Methods. Countries with an increase, decrease and no change in suicide rates with increasing age were ascertained from an earlier study (Shah, 2007a, International Psychogeriatrics, 19, 1141), which analysed data from the World Health Organisation (WHO). The relationship between age-related trends in suicide rates and (i) child mortality rates, (ii) life expectancy and (iii) markers of socio-economic status (per capita gross national domestic product (GDP) and the Gini coeffcient) was examined using data from the WHO and the United Nations. Results. The main findings were: (i) child mortality rates were significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; (ii) life expectancy was significantly higher in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; and (iii) the Gini coefficient was significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change or a decline in suicide rates with increasing age in females. Conclusions. Potential explanations for these findings and the interaction of life expectancy and socio-economic factors with other factors that differentially influence suicide rates in different age and sex groups requires further examination.
Park, H.; Slanger, T. G.
1994-01-01
Vibrationally excited oxygen (O‡2) is produced in the atmosphere by ozone photodissociation in the 200-300 nm Hartley band. It has been suggested that photoexcitation of O‡2 in the O2 Schumann-Runge bands will lead to predissociation, and autocatalytic production of O3. The resultant new source of atmospheric O3 could help alleviate current discrepancies between observed and modeled O3 profiles. To evaluate this possibility, we have examined two critical factors—the nascent distribution of O‡2 levels for 248 nm photodissociation, near the peak of the Hartley band, and the rate coefficients for their relaxation by O2 and N2. We find that the distribution extends to v=22, close to the thermodynamic limit, with a peak near v=8. The 300 K quenching rate coefficients have been evaluated using a cascade model, in which it is assumed that relaxation by O2 occurs through single-quantum vibration-vibration (V-V) and vibration-translation (V-T) steps. By modeling the relaxation from the top of the distribution downwards, we simultaneously obtain both the quenching rate coefficients and the nascent vibrational distribution. Agreement with new rate coefficient measurements carried out in a state-specific manner is good, as is also true for the comparison with new V-V and V-T calculations. Data from experiments on O‡2 quenching by N2 show that in the v=16-22 range, potentially important in the atmosphere, quenching proceeds up to five times faster than for the case of O2. The hypothesized explanation is that two-quantum V-V transfer, peaking at the resonant condition of O2(v=18-19), is the dominant process. As a consequence, atmospheric quenching of O‡2 for levels above v=14 is basically controlled by N2, and at low stratospheric temperatures, the effect of N2 quenching near v=18 is likely to be 2 orders of magnitude greater than quenching by O2. This unexpected effect probably precludes a significant role for O‡2 photodissociation as a new source of stratospheric
Fernandez, Rafael P. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina); Palancar, Gustavo G. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina)]. E-mail: palancar@fcq.unc.edu.ar; Madronich, Sasha [Atmospheric Chemistry Division, National Center for Atmospheric Research, 1850 Table mesa Drive, Boulder, CO, 80303 (United States); Toselli, Beatriz M. [INFIQC, Centro Laser de Ciencias Moleculares, Departamento de Fisico Quimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, 5000, Cordoba (Argentina)]. E-mail: tosellib@fcq.unc.edu.ar
2007-03-15
A line by line (LBL) method to calculate highly resolved O{sub 2} absorption cross sections in the Schumann-Runge (SR) bands region was developed and integrated in the widely used Tropospheric Ultraviolet Visible (TUV) model to calculate accurate photolysis rate coefficients (J values) in the upper atmosphere at both small and large solar zenith angles (SZA). In order to obtain the O{sub 2} cross section between 49,000 and 57,000cm{sup -1}, an algorithm which considers the position, strength, and half width of each spectral line was used. Every transition was calculated by using the HIgh-resolution TRANsmission molecular absorption database (HITRAN) and a Voigt profile. The temperature dependence of both the strength and the half widths was considered within the range of temperatures characteristic of the US standard atmosphere, although the results show a very good agreement also at 79K. The cross section calculation was carried out on a 0.5cm{sup -1} grid and the contributions from all the lines lying at +/-500cm{sup -1} were considered for every wavelength. Both the SR and the Herzberg continuums were included. By coupling the LBL method to the TUV model, full radiative transfer calculations that compute J values including Rayleigh scattering at high altitudes and large SZA can now be done. Thus, the J values calculations were performed for altitudes from 0 to 120km and for SZA up to 89{sup o}. The results show, in the J{sub O{sub 2}} case, differences of more than +/-10% (e.g. at 96km and 30{sup o}) when compared against the last version of the TUV model (4.4), which uses the Koppers and Murtagh parameterization for the O{sub 2} cross section. Consequently, the J values of species with cross sections overlapping the SR band region show variable differences at lower altitudes. Although many species have been analyzed, the results for only four of them (O{sub 2}, N{sub 2}O, HNO{sub 3}, CFC12) are presented. Due to the fact that the HNO{sub 3} absorption cross
Guo, JunJiang; Xu, JiaQi; Li, ZeRong; Tan, NingXin; Li, XiangYuan
2015-04-02
The potential energy surface (PES) for reaction C2H4 + HO2 was examined by using the quantum chemical methods. All rates were determined computationally using the CBS-QB3 composite method combined with conventional transition state theory(TST), variational transition-state theory (VTST) and Rice-Ramsberger-Kassel-Marcus/master-equation (RRKM/ME) theory. The geometries optimization and the vibrational frequency analysis of reactants, transition states, and products were performed at the B3LYP/CBSB7 level. The composite CBS-QB3 method was applied for energy calculations. The major product channel of reaction C2H4 + HO2 is the formation C2H4O2H via an OH(···)π complex with 3.7 kcal/mol binding energy which exhibits negative-temperature dependence. We further investigated the reactions related to this complex, which were ignored in previous studies. Thermochemical properties of the species involved in the reactions were determined using the CBS-QB3 method, and enthalpies of formation of species were compared with literature values. The calculated rate constants are in good agreement with those available from literature and given in modified Arrhenius equation form, which are serviceable in combustion modeling of hydrocarbons. Finally, in order to illustrate the effect for low-temperature ignition of our new rate constants, we have implemented them into the existing mechanisms, which can predict ethylene ignition in a shock tube with better performance.
On Relations Between Gini Coefficient and Inhabitants Personal Income Distribution%论基尼系数与居民个人收入分配的关系
周德海
2012-01-01
学术界通常以基尼系数的大小，作为衡量居民个人收入分配是否公平的依据，是对基尼系数与居民个人收入分配之间关系的误解。一个国家基尼系数的大小，与这个国家居民的个人收入分配是否公平没有关系。马克思经济学的等价交换原则是衡量居民个人收入分配是否公平的客观标准。%Equality, equity and justice can not include the relations between Gini coefficient and inhabitants'per- sonal income distribution fully. There never any equal income distribution throughout the history of human socie- ty, for which the meaning of equality in such concepts as equal or unequal distribution is unclear. Although distri- bution of social wealth represented by Gini coefficient is determined by inhabitants'personal income distribution, Gini coefficient cant reflect a definite inhabitants'personal income distribution is fair or unfair. Only exchange of equal values in a system of market economy is fair.
Kristensen, Gustav
2013-01-01
Cohorts are the aggregate of individuals who experience the same event within the same time interval. Cohorts can be based on people born in a given year, for example in 1940 or within a span of years, e.g. born in 1940-1944. The year of birth is here the defining event for cohorts. The health di...... differs between cohorts. This article focuses on the protective and detrimental cohort effect in relation to the risk of death from apoplexy. A dummy variable method is recommended to describe the changing cohort effect over a century....
Zhijian Liu
2015-08-01
Full Text Available The determinations of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.
Emergence of dynamical complexity related to human heart rate variability
Chang, Mei-Chu; Peng, C.-K.; Stanley, H. Eugene
2014-12-01
We apply the refined composite multiscale entropy (MSE) method to a one-dimensional directed small-world network composed of nodes whose states are binary and whose dynamics obey the majority rule. We find that the resulting fluctuating signal becomes dynamically complex. This dynamical complexity is caused (i) by the presence of both short-range connections and long-range shortcuts and (ii) by how well the system can adapt to the noisy environment. By tuning the adaptability of the environment and the long-range shortcuts we can increase or decrease the dynamical complexity, thereby modeling trends found in the MSE of a healthy human heart rate in different physiological states. When the shortcut and adaptability values increase, the complexity in the system dynamics becomes uncorrelated.
Werfelli, Ghofran [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Halvick, Philippe; Stoecklin, Thierry [Université de Bordeaux, Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence Cedex (France); Honvault, Pascal [Université de Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, CNRS UMR 6303, 21078 Dijon Cedex (France); Université de Franche-Comté, UFR ST, 25030 Besançon Cedex (France); Kerkeni, Boutheïna [Faculté des Sciences de Tunis, Université de Tunis El-Manar, Laboratoire de Physique de la Matière Condensée, 2092 Tunis (Tunisia); Institut Supérieur des Arts Multimédia de la Manouba, Université de la Manouba, 2010 la Manouba (Tunisia)
2015-09-21
The observed abundances of the methylidyne cation, CH{sup +}, in diffuse molecular clouds can be two orders of magnitude higher than the prediction of the standard gas-phase models which, in turn, predict rather well the abundances of neutral CH. It is therefore necessary to investigate all the possible formation and destruction processes of CH{sup +} in the interstellar medium with the most abundant species H, H{sub 2}, and e{sup −}. In this work, we address the destruction process of CH{sup +} by hydrogen abstraction. We report a new calculation of the low temperature rate coefficients for the abstraction reaction, using accurate time-independent quantum scattering and a new high-level ab initio global potential energy surface including a realistic model of the long-range interaction between the reactants H and CH{sup +}. The calculated thermal rate coefficient is in good agreement with the experimental data in the range 50 K–800 K. However, at lower temperatures, the experimental rate coefficient takes exceedingly small values which are not reproduced by the calculated rate coefficient. Instead, the latter rate coefficient is close to the one given by the Langevin capture model, as expected for a reaction involving an ion and a neutral species. Several recent theoretical works have reported a seemingly good agreement with the experiment below 50 K, but an analysis of these works show that they are based on potential energy surfaces with incorrect long-range behavior. The experimental results were explained by a loss of reactivity of the lowest rotational states of the reactant; however, the quantum scattering calculations show the opposite, namely, a reactivity enhancement with rotational excitation.
Linek, V., E-mail: linekv@vscht.cz [Prague Institute of Chemical Technology, Department of Chemical Engineering, CZ-166 28 Prague 6 (Czech Republic); Košek, L. [Research Centre Řež, CZ-250 68 Husinec-Řež (Czech Republic); Moucha, T.; Rejl, F.J.; Kordač, M.; Valenz, L.; Opletal, M. [Prague Institute of Chemical Technology, Department of Chemical Engineering, CZ-166 28 Prague 6 (Czech Republic)
2014-11-15
Highlights: • The model of hydrogen isotopes desorption from lead lithium alloy in packed column is presented. • Mass transfer coefficient k{sub L}a are evaluated from Alpy's Melodie loop experiments. • Packing height and efficiency of packed columns in DEMO plant for DCLL and HCLL are evaluated. • Effects of liquid phase axial dispersion, surface tension and wettability of packing are evaluated. • Effect of flow rate of the purge gas on packing height and desorption efficiency is evaluated. - Abstract: The model of the desorption of hydrogen isotopes from lead lithium alloy in a packed column is derived from the first principles using the plug flow in the liquid phase either the plug flow or ideal mixing in the gas phases. Sievert's law of non-linear equilibrium is followed. The volumetric mass transfer coefficient k{sub L}a and its dependence on the liquid metal flow rate are evaluated on the basis of the Melodie loop experiments. The presented model is used for evaluation of the minimum flow rate of the purge gas for which the concentration of the isotope in the gas leaving the column is at its highest, while the driving force of the interfacial transport of the isotope is still not reduced and the tritium desorption efficiency is therefore retained. The potential effect of the axial dispersion in the gas and liquid phase is evaluated. Highlighted are the issues of the optimum packing geometric surface area, above which the efficiency starts to decrease, and of the role of the surface tension and the contact angle with regard to the wettability of the packing. On the basis of the findings related to these factors, the Mellapak 500 Y and Mellapak packings with flat surfaces are recommended for the tests aiming to intensify the tritium desorption efficiency in the packed columns. The models were used for the engineering sizing of the packed columns in two breeding blanket concepts for the DEMO plant – utilizing DCLL (dual coolant lead lithium
Alwe, H. D.; Walavalkar, M. P.; Sharma, A.; Dhanya, S.; Naik, P. D.
2014-01-01
The rate coefficients of the reactions of three unsaturated cyclic ethers, 2,5-dihydrofuran (2,5-DHF), 2,3-dihydrofuran (2,3-DHF), and 3,4-dihydropyran (3,4-DHP), with the major day-time tropospheric oxidants - OH (kOH) and O3(kO3), and that of 3,4-DHP with Cl atom (kCl) are determined using relative rate method, at 298 K. The values of kOH are (6.45 ± 1.69), (11.95 ± 2.79) and (11.38 ± 2.64) × 10-11 cm3 molecule-1 s-1 for 2,5-DHF, 2,3-DHF and 3,4-DHP, respectively and kO3 are (1.65 ± 0.31), (443.20 ± 79.0) and (31.36 ± 5.80) × 10-17 cm3 molecule-1 s-1 for 2,5-DHF, 2,3-DHF and 3,4-DHP, respectively. The value of kCl for 3,4-DHP is (6.15 ± 0.84) × 10-10 cm3 molecule-1 s-1. The dominant pathway of tropospheric degradation of 2,5-DHF is the reaction with OH, whereas that of 2,3-DHF is the reaction with O3. Reaction with both OH and O3 are equally important in the case of 3,4-DHP. Under the conditions of marine boundary layer, the reaction with Cl atom is important in the tropospheric degradation of 2,5-DHF and 3,4-DHP, but insignificant in the case of 2,3-DHF (only 1.8%). The estimated tropospheric lifetimes in the day-time are 2.0, 0.08 and 0.62 h for 2,5-DHF, 2,3-DHF and 3,4-DHP respectively. The presence of O atom, unsaturation, conjugation etc. influences the rate coefficients in a complex manner. However, there is a good correlation of kOH with HOMO energy, which further improves by treating the molecules separately, either as ethers and hydrocarbons, or as cyclic and acyclic molecules. The values of kO3 of these ethers fit very well with the straight line regression derived for simple alkenes with their HOMO energy, except 2,3-DHF, which has a high strain enthalpy. The values of kCl also show a similar trend of increase with HOMO energy, but the correlation is not as good as that of kOH.
Local Rank Inference for Varying Coefficient Models.
Wang, Lan; Kai, Bo; Li, Runze
2009-12-01
By allowing the regression coefficients to change with certain covariates, the class of varying coefficient models offers a flexible approach to modeling nonlinearity and interactions between covariates. This paper proposes a novel estimation procedure for the varying coefficient models based on local ranks. The new procedure provides a highly efficient and robust alternative to the local linear least squares method, and can be conveniently implemented using existing R software package. Theoretical analysis and numerical simulations both reveal that the gain of the local rank estimator over the local linear least squares estimator, measured by the asymptotic mean squared error or the asymptotic mean integrated squared error, can be substantial. In the normal error case, the asymptotic relative efficiency for estimating both the coefficient functions and the derivative of the coefficient functions is above 96%; even in the worst case scenarios, the asymptotic relative efficiency has a lower bound 88.96% for estimating the coefficient functions, and a lower bound 89.91% for estimating their derivatives. The new estimator may achieve the nonparametric convergence rate even when the local linear least squares method fails due to infinite random error variance. We establish the large sample theory of the proposed procedure by utilizing results from generalized U-statistics, whose kernel function may depend on the sample size. We also extend a resampling approach, which perturbs the objective function repeatedly, to the generalized U-statistics setting; and demonstrate that it can accurately estimate the asymptotic covariance matrix.
Sheng, Wang; Yun, Kang; Xianli, Li
2016-11-01
Within the quasi-one-dimensional effective potential model and effective mass approximation, we obtain the wavefunctions and energy eigenvalues of the ground (j = 1) and first 2 excited states (j = 2 and 3) of a donor impurity in a rectangular GaAs quantum dot in the presence of electric field. The donor impurity-related linear and nonlinear optical absorption as well as refractive index changes for the transitions j = 1-2 and j = 2-3 are investigated. The results show that the impurity position, incident optical intensity and electric field play important roles in the optical absorption coefficients and refractive index changes. We find that the impurity effect induces the blueshift for j = 1-2 and redshift for j = 3-2 in the absence of the electric field, but it leads to redshift for j = 1-2 and blueshift for j = 3-2 in the existence of the field. Also, the optical coefficient for the higher energy transitions j = 2-3 is insensitive to variation of impurity positions, while that for the low energy transition j = 1-2 depends significantly on the positions of impurity. In addition, the saturation and splitting phenomenon of the optical absorption are observed as the incident optical intensity increases. Project supported by the Science and Technology Project of Education Department of Heilongjiang Province of China (No. 12541070).
Rojas-Briseño, J.G.; Martínez-Orozco, J.C.; Rodríguez-Vargas, I. [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esquina con Paseo la Bufa S/N, C.P. 98060, Zacatecas, Zac. (Mexico); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Instituto de Física, Universidad de Antioquia, AA 1226, Medellín (Colombia); Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Instituto de Física, Universidad de Antioquia, AA 1226, Medellín (Colombia)
2013-09-01
In this work we are reporting the energy level spectrum for a quantum system consisting of an n-type double δ-doped quantum well with a Schottky barrier potential in a Gallium Arsenide matrix. The calculated states are taken as the basis for the evaluation of the linear and third-order nonlinear contributions to the optical absorption coefficient and to the relative refractive index change, making particular use of the asymmetry of the potential profile. These optical properties are then reported as a function of the Schottky barrier height (SBH) and the separation distance between the δ-doped quantum wells. Also, the effects of the application of hydrostatic pressure are studied. The results show that the amplitudes of the resonant peaks are of the same order of magnitude of those obtained in the case of single δ-doped field effect transistors; but tailoring the asymmetry of the confining potential profile allows the control the resonant peak positions.
Wang, Kai; Phillips, Charles A; Rogers, Gary L; Barrenas, Fredrik; Benson, Mikael; Langston, Michael A
2014-01-01
Differential expression has been a standard tool for analysing case-control transcriptomic data since the advent of microarray technology. It has proved invaluable in characterising the molecular mechanisms of disease. Nevertheless, the expression profile of a gene across samples can be perturbed in ways that leave the expression level unaltered, while a biological effect is nonetheless present. This paper describes and analyses differential Shannon entropy and differential coefficient of variation, two alternate techniques for identifying genes of interest. Ontological analysis across 16 human disease datasets demonstrates that these alternatives are effective at identifying disease-related genes not found by mere differential expression alone. Because the two alternate techniques are based on somewhat different mathematical formulations, they tend to produce somewhat different gene lists. Moreover, each may pinpoint genes completely overlooked by the other. Thus, measures of entropy and variation can be used to replace or better yet augment standard differential expression computations.
Han, Shu-ying; Qiao, Jun-qin; Zhang, Yun-yang; Yang, Li-li; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan
2011-03-01
n-Octanol/water partition coefficients (P) for DDTs and dicofol were determined by reversed-phase high performance liquid chromatography (RP-HPLC) on a C(18) column using methanol-water mixture as mobile phase. A dual-point retention time correction (DP-RTC) was proposed to rectify chromatographic retention time (t(R)) shift resulted from stationary phase aging. Based on this correction, the relationship between logP and logk(w), the logarithm of the retention factor extrapolated to pure water, was investigated for a set of 12 benzene homologues and DDT-related compounds with reliable experimental P as model compounds. A linear regression logP=(1.10±0.04) logk(w) - (0.60±0.17) was established with correlation coefficient R(2) of 0.988, cross-validated correlation coefficient R(cv)(2) of 0.983 and standard deviation (SD) of 0.156. This model was further validated using four verification compounds, naphthalene, biphenyl, 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (p,p'-DDD) and 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (p,p'-DDE) with similar structure to DDT. The RP-HPLC-determined P values showed good consistency with shake-flask (SFM) or slow-stirring (SSM) results, especially for highly hydrophobic compounds with logP in the range of 4-7. Then, the P values for five DDT-related compounds, 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1,1-trichloroethane (o,p'-DDT), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethane (o,p'-DDD), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethene (o,p'-DDE), and 2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol (dicofol) and its main degradation product 4,4'-dichlorobenzophenone (p,p'-DBP) were evaluated by the improved RP-HPLC method for the first time. The excellent precision with SD less than 0.03 proved that the novel DP-RTC protocol can significantly increases the determination accuracy and reliability of P by RP-HPLC.
Jaffe, Richard; Schwenke, David; Chaban, Galina; Panesi, Marco
2014-01-01
Development of High-Fidelity Physics-Based Models to describe hypersonic flight through the atmospheres of Earth and Mars is underway at NASA Ames Research Center. The goal is to construct chemistry models of the collisional and radiative processes that occur in the bow shock and boundary layers of spacecraft during atmospheric entry that are free of empiricism. In this talk I will discuss our philosophy and describe some of our progress. Topics to be covered include thermochemistry, internal energy relaxation, collisional dissociation and radiative emission and absorption. For this work we start by solving the Schrodinger equation to obtain accurate interaction potentials and radiative properties. Then we invoke classical mechanics to compute state-specific heavy particle collision cross sections and reaction rate coefficients. Finally, phenomenological rate coefficients and relaxation times are determined from master equation solutions.
Rate of vision loss in neovascular age-related macular degeneration explored.
Real, Juan P; Granero, Gladys E; De Santis, Mariana O; Juarez, Claudio P; Palma, Santiago D; Kelly, Simon P; Luna, José D
2015-11-01
To explore decline in visual acuity in patients with neovascular age-related macular degeneration (n-AMD) awaiting intravitreal bevacizumab or ranibizumab treatment following initial diagnosis and after disease reactivation. Retrospective analysis of 74 treatment-naïve patients (84 eyes) in two centers in Córdoba, Argentina. The time between treatment indication and intravitreal injection, and the changes in BCVA produced during this delay were studied in both periods. A linear regression model to search the impact of time on progression visual impairment was conducted. In both periods, a significant reduction in vision occurred awaiting intravitreal injection. The longer the delay, the greater the vision loss (R2 = 0.55 p < 0.01) and the less improvement following treatment (Pearson coefficient -0.26). The result of the model shows that the change in vision as a function of initial delay were best described by a polynomic model with a mean loss of 5 letters in the first 3 weeks, a slowdown in the rate of change of VA, and a dependence of visual acuity at the moment of diagnosis . The loss of visual acuity after reactivation shows the same behavior as at the onset of the disease but independent of visual acuity prior to reactivation. Visual loss awaiting injection intravitreal anti-VEGF is clinically significant and with an asymptotic pattern, with early rapid loss of vision in both the onset of the disease and the reactivation. Initiation of anti-VEGF treatment must be undertaken urgently, as should retreatment of disease activation to reduce visual loss.
Bakker, H.
1974-01-01
To evaluate the effect of selection for parameters of a growth curve, four selection lines and a control line were started from one base population. In the selection lines is selected for a large and a small relative growth rate between 21 and 29 days (RGH and RGL) and for a large and small bodyweig
Rates of TBI-related Deaths by Age Group — United States, 2001–2010
U.S. Department of Health & Human Services — Changes in the rates of TBI-related deaths vary depending on age. For persons 44 years of age and younger, TBI-related deaths decreased between the periods of...
Zhang, Hong Lin; Graziani, Mark; Pradhan, Anil K.
1994-01-01
Collison strengths and maxwellian averaged rate coefficients have been calculated for the 105 transitions among all 15 fine structure levels of the 8 LS terms 2s(sup 2) 2 P(P-2(sup 0 sub 1/, 3/2)), 2s2p(sup 2)(P-4(sub 1/2,3/2,5/2), D-2(sub 3/2, 5/2), S-2(sub 1/2), P-2(sub 1/2, 3/2)), 2p(sup 3)(S-4(sup 0)(sub 3/2), D-2(sup 0 sub 3/2, 5/2), P-2(sup 0 sub 1/2, 3/2)) in highly- charged B-like Ne, Mg, Al, Si, S, Ar, Ca and Fe. Rate coefficients have been tabulated at a wide range of temperatures, depending on the ion charge and abundance in plasma sources. Earlier work for O IV has also been extended to include the high temperature range. A brief discussion of the calculations, sample results, and comparison with earlier works is also given. While much of the new data should be applicable to UV spectral diagnostics, the new rates for the important ground state fine structure transition P-2(sup 0 sub 1/2)-P-2(sup 0 sub 3/2) should result in significant revision of the IR cooling rates in plasmas where B-like ions are prominent constituents, since the new rate coefficients are generally higher by several factors compared with the older data.
Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn; Chen, Jun, E-mail: chenjun@dicp.ac.cn; Zhang, Dong H., E-mail: zhangdh@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China)
2015-09-14
The ring polymer molecular dynamics (RPMD) calculations are performed to calculate rate constants for the title reaction on the recently constructed potential energy surface based on permutation invariant polynomial (PIP) neural-network (NN) fitting [J. Li et al., J. Chem. Phys. 142, 204302 (2015)]. By inspecting convergence, 16 beads are used in computing free-energy barriers at 300 K ≤ T ≤ 1000 K, while different numbers of beads are used for transmission coefficients. The present RPMD rates are in excellent agreement with quantum rates computed on the same potential energy surface, as well as with the experimental measurements, demonstrating further that the RPMD is capable of producing accurate rates for polyatomic chemical reactions even at rather low temperatures.
CAO Wenxi; YANG Yuezhong; LIU Sheng; XU Xiaoqiang; YANG Dingtian; ZHANG Jianlin
2005-01-01
The spectral absorption coefficient of phytoplankton in coastal waters of southern China is investigated. Large variations in the absorption coefficient of phytoplankton are found. The absorption coefficient of phytoplankton at 443 nm ranged from 0. 006 m- 1 to 0. 484 m - 1, with an average value of 0. 067 m - 1. The chlorophyll-specific absorption coefficient of phytoplankton is also a bio-optical varito pigment composition of phytoplankton and package effect. The chlorophyll-specific absorption coefficient of phytoplankton decreases with the increasing of chlorophyll a concentration. This relationship can be described by a power law function, with the parameters and the coefficient of determination r2 as functions of wavelength, but the parameters describing the relationships in present study differed from that in Case 1 waters, thus the regional adjustment of model parameters was of particular significance for improving the accuracy of bio-optical algorithms for estimation of Chl-a concentration and primary production from remotely sensed data. Regression analysis of reflectance (R rs) ratio and absorption coefficient of phytoplankton (a ph) indicates a close correlation between them, which means that it is possible to retrieve absorption coefficient of phytoplankton using ocean color remote sensing data in optically complex coastal waters.
The Relation Between Damping and Reaction Rates of Fermions in Hot Gauge Theories
Ayala, A P; Weber, A; Ayala, Alejandro; Olivo, Juan Carlos D'; Weber, Axel
1998-01-01
We examine the relation between the damping rate of a chiral fermion mode propagating in a hot plasma and the rate at which the mode approaches equilibrium. We show that these two quantities, obtained from the imaginary part of the fermion self-energy, are equal provided the reaction rate is defined using the appropriate wave function of the mode in the medium.
Meng, Qingyong; Chen, Jun
2017-01-01
To accurately compute the rates of the abstraction channels of hydrogen plus ethane (Et), propane (Pr), and dimethyl ether (DME), ring-polymer molecular dynamics (RPMD) method is used in conjunction with the recently constructed local permutation invariant polynomial neural-networks potential energy surface of the parent H + CH4 system [Q. Meng et al., J. Chem. Phys. 144, 154312 (2016)]. For H + Et, one of the H atoms in CH4 of the parent system is replaced by a methyl group, while for the H + DME reaction, it is replaced by the methoxyl group. For the H + Pr reaction, replacing one of the H atoms in CH4 by an ethyl group, the terminal channel is built, meanwhile the middle channel is considered through replacing two H atoms in CH4 by two methyl groups. Since the potential energy barriers of the title reactions must differ from the H + CH4 barrier, the corrections have to be made by computing the ratio of free-energy barriers between H + CH4 and the title reactions at coupled cluster with a full treatment singles and doubles (where the triples contribution is calculated by perturbation theory, that is, CCSD(T)) level. Comparing the present RPMD rates with the previous theoretical and experimental results, good agreement can be found. Moreover, probable reasons for the deviation between the present RPMD rates and the previous experimental ones are discussed.
Sakayanagi, Yoshihiro; Nakaura, Shigeki; Sampei, Mitsuji
The solvable condition of nonlinear H∞ control problems is given by the Hamilton Jacobi inequality (HJI). The state-dependent Riccati inequality (SDRI) is one of the approaches used to solve the HJI. The SDRI contains the state-dependent coefficient (SDC) form of a nonlinear system. The SDC form is not unique. If a poor SDC form is chosen, then there is no solution for the SDRI. In other words, there exist free parameters of the SDC form that affect the solvability of the SDRI. This study focuses on the free parameters of the SDC form. First, a representation of the free parameters of the SDC form is introduced. The solvability of an SDRI is a sufficient condition for that of the related HJI, and the free parameters affect the conservativeness of the SDRI approach. In addition, a new method for designing the free parameters that reduces the conservativeness of the SDRI approach is introduced. Finally, numerical examples to verify the effect of this method are presented.
Huisman, Thierry A G M; Loenneker, Thomas; Barta, Gerd; Bellemann, Matthias E; Hennig, Juergen; Fischer, Joachim E; Il'yasov, Kamil A
2006-08-01
The objectives were to study the "impact" of the magnetic field strength on diffusion tensor imaging (DTI) metrics and also to determine whether magnetic-field-related differences in T2-relaxation times of brain tissue influence DTI measurements. DTI was performed on 12 healthy volunteers at 1.5 and 3.0 Tesla (within 2 h) using identical DTI scan parameters. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured at multiple gray and white matter locations. ADC and FA values were compared and analyzed for statistically significant differences. In addition, DTI measurements were performed at different echo times (TE) for both field strengths. ADC values for gray and white matter were statistically significantly lower at 3.0 Tesla compared with 1.5 Tesla (% change between -1.94% and -9.79%). FA values were statistically significantly higher at 3.0 Tesla compared with 1.5 Tesla (% change between +4.04 and 11.15%). ADC and FA values are not significantly different for TE=91 ms and TE=125 ms. Thus, ADC and FA values vary with the used field strength. Comparative clinical studies using ADC or FA values should consequently compare ADC or FA results with normative ADC or FA values that have been determined for the field strength used.
Hayashi, R
2000-09-01
We studied the relationship between accuracy in the cognitive process and components of event-related potentials (P300) in 21 young and healthy subjects. Benzodiazepine was used to manipulate the cognitive state of the subjects. We recorded the serial changes in P300, choice reaction time (CRT), and error ratio (ER) before and after oral administration of 0.4 mg of alprazolam. After administration, the coefficient of variation of CRT tended to decrease in nine subjects (group I) and increase in 12 subjects (group II). Prolongation of the P300 latency was observed in all subjects after treatment; however, such change was more predominant in group II than in group I. In group I, there was no error and no significant difference in P300 amplitude before and after administration. In group II, alprazolam significantly reduced P300 amplitude and increased ER. Our results suggest that the accuracy and P300 amplitude were preserved when the central nerve system managed to reduce fluctuations in CRT but P300 amplitude diminished and the error ratio increased following deterioration of these processes.
S.B. Jonnalagadda
2012-08-01
Full Text Available ‘Simkine3’, a Delphi based software is developed to simulate the kinetic schemes of complex reaction mechanisms involving multiple sequential and competitive elementary steps for homogeneous and heterogeneous chemical reactions. Simkine3 is designed to translate the user specified mechanism into chemical first-order differential equations (ODEs and optimise the estimated rate constants in such a way that simulated curves match the experimental kinetic profiles. TLSoda which uses backward differentiation method is utilised to solve resulting ODEs and Downhill Simplex method is used to optimise the estimated rate constants in a robotic way. An online help file is developed using HelpScrible Demo to guide the users of Simkine3. The versatility of the software is demonstrated by simulating the complex reaction between methylene violet and acidic bromate, a reaction which exhibits complex nonlinear kinetics. The new software is validated after testing it on a 19-step intricate mechanism involving 15 different species. The kinetic profiles of multiple simulated curves, illustrating the effect of initial concentrations of bromate, and bromide were matched with the corresponding experimental curves.DOI: http://dx.doi.org/10.4314/bcse.v26i2.10
McGillen, Max R; Baasandorj, Munkhbayar; Burkholder, James B
2013-06-01
Butanol (C4H9OH) is a potential biofuel alternative in fossil fuel gasoline and diesel formulations. The usage of butanol would necessarily lead to direct emissions into the atmosphere; thus, an understanding of its atmospheric processing and environmental impact is desired. Reaction with the OH radical is expected to be the predominant atmospheric removal process for the four aliphatic isomers of butanol. In this work, rate coefficients, k, for the gas-phase reaction of the n-, i-, s-, and t-butanol isomers with the OH radical were measured under pseudo-first-order conditions in OH using pulsed laser photolysis to produce OH radicals and laser induced fluorescence to monitor its temporal profile. Rate coefficients were measured over the temperature range 221-381 K at total pressures between 50 and 200 Torr (He). The reactions exhibited non-Arrhenius behavior over this temperature range and no dependence on total pressure with k(296 K) values of (9.68 ± 0.75), (9.72 ± 0.72), (8.88 ± 0.69), and (1.04 ± 0.08) (in units of 10(-12) cm(3) molecule(-1) s(-1)) for n-, i-, s-, and t-butanol, respectively. The quoted uncertainties are at the 2σ level and include estimated systematic errors. The observed non-Arrhenius behavior is interpreted here to result from a competition between the available H-atom abstraction reactive sites, which have different activation energies and pre-exponential factors. The present results are compared with results from previous kinetic studies, structure-activity relationships (SARs), and theoretical calculations and the discrepancies are discussed. Results from this work were combined with available high temperature (1200-1800 K) rate coefficient data and room temperature reaction end-product yields, where available, to derive a self-consistent site-specific set of reaction rate coefficients of the form AT(n) exp(-E/RT) for use in atmospheric and combustion chemistry modeling.
裴庆; 赵凤起; 郝海霞; 徐司雨; 张衡
2016-01-01
为了揭示RDX‐CMDB推进剂中各常见组分对其燃速温度敏感系数的影响规律，制备了一系列含RDX、铝粉及燃烧催化剂的CMDB推进剂样品。采用氮气靶线法测得其在2～14MPa下的燃速温度敏感系数（σp）。讨论了RDX含量、铝粉、燃烧催化剂对RDX‐CMDB推进剂燃速温度敏感系数的影响。结果表明，提高工作压强、增加RDX含量、添加燃烧催化剂均有助于降低RDX‐CMDB推进剂在一定初始条件下的燃速温度敏感系数。配方中引入铝粉后可降低中低压下RDX‐CMDB推进剂的燃速温度敏感系数，且燃速温度敏感系数几乎不随压强变化而变化。选用含邻苯二甲酸铅和没食子酸铋锆作燃烧催化剂，均可在2～10MPa下降低RDX‐CMDB推进剂的燃速压强指数，同时降低燃速温度敏感系数。%In order to reveal the effects of the commonly used component on temperature sensitivity coefficient of burning rate for RDX‐CMDB propellant ,a series of propellant samples containing RDX ,aluminium powder and combustion catalyst were prepared .Their temperature sensitivity coefficients of burning rate σP were determined at the pressure of 2MPa to 14MPa by using nitrogen strand burner method .The influences of RDX content ,aluminium powder and combustion cata‐lysts on the temperature sensitivity coefficient of burning rate were discussed .The results show that the increase of working pressure and RDX content and the addition of combustion catalyst are healpful to reduce the temperature sensitivity coeffi‐cient of burning rate of RDX‐CMDB propellant under certain initial conditions .After introducing aluminium powder into the formulation ,the temperature sensitivity coefficient of burning rate of RDX‐CMDB propellant at middle and low pressures can be reduced and is almost not changed with the pressure .Using lead phthalate and bismuth/zirconium gallate as combus‐tion catalyst may reduce pressure exponent of
Certain Binomial Sums with recursive coefficients
Kilic, Emrah
2010-01-01
In this short note, we establish some identities containing sums of binomials with coefficients satisfying third order linear recursive relations. As a result and in particular, we obtain general forms of earlier identities involving binomial coefficients and Fibonacci type sequences.
Esco, Michael R; Williford, Henry N; Olson, Michele S
2011-08-01
The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max.
Douglas, Kevin; Slater, Eloise; Blitz, Mark; Plane, John; Heard, Dwayne; Seakins, Paul
2016-04-01
The Cassini-Huygens mission to Titan revealed unexpectedly large amounts of benzene in the troposphere, and confirmed the absence of a global ethane ocean as predicted by photochemical models of methane conversion over the lifetime of the solar system. An important chemical intermediate in both the production and loss of benzene and ethane is the first electronically excited state of methylene, 1CH2. For example, at room temperature an important reaction of 1CH2 is with acetylene (R1a), leading to the formation of propargyl (C3H3)[1]. The subsequent recombination of propargyl radicals is the major suggested route to benzene in Titan's atmosphere (R2)[2]. In addition to reaction of 1CH2 leading to products, there is also competition between inelastic electronic relaxation to form the ground triplet state 3CH2 (R1b). This ground state 3CH2 has a markedly different reactivity to the singlet, reacting primarily with methyl radicals (CH3) to form ethene (R3). As methyl radical recombination is the primary route to ethane (R4)[3], reactions of 1CH2 will also heavily influence the ethane budget on Titan. 1CH2 + C2H2 → C3H3 + H (R1a) 1CH2 + C2H2 → 3CH2 + C2H2 (R1b) C3H3 + C3H3 → C6H6 (R2) 3CH2 + CH3 → C2H4 + H (R3) CH3 + CH3 (+ M) → C2H6 (R4) Thus this competition between chemical reaction and electronic relaxation in the reactions of 1CH2 with H2, CH4, C2H4, and C2H6 will play an important role in determining the benzene and ethane budgets on Titan. Despite this there are no measurements of any rate constants for 1CH2 at temperatures relevant to Titan's atmosphere (60 - 170 K). Using a pulsed Laval nozzle apparatus coupled with pulsed laser photolysis laser-induced fluorescence, the low temperature reaction kinetics for the removal of 1CH2 with nitrogen, hydrogen, methane, ethane, ethene, acetylene, and oxygen, have been studied. The results revealed an increase in the removal rate of 1CH2 at temperatures below 200 K, with a sharp increase of around a factor of
Iorio, Lorenzo
2010-01-01
We numerically investigate the impact of the General Theory of Relativity (GTR) on the satellite-to-satellite range \\rho and range-rate \\dot\\rho of the twin GRACE A/B spacecrafts through their dynamical equations of motion. The present-day accuracies in measuring such observables are \\sigma_\\rho <= 1-10 micron, \\sigma_\\dot\\rho <= 1 micron s^-1. Studies for a follow-on of such a mission points toward a range-rate accuracy of the order of \\sigma_\\dot\\rho = 1 nm s^-1 or better. We also compute the dynamical range and range-rate perturbations caused by the first six zonal harmonic coefficients J_L, L=2,3,4,5,6,7$ of the classical multipolar expansion of the terrestrial gravitational potential in order to evaluate their aliasing impact on the relativistic effects. Conversely, we also quantitatively assessed the possible a-priori \\virg{imprinting} of GTR itself, not solved-for in all the GRACE-based Earth's gravity models produced so far, on the estimated values of the low degree zonals of the geopotential. T...
汪贺模; 蔡庆伍; 余伟; 苏岚
2012-01-01
Establishing an accuracy relationship between the convective heat transfer coefficient and cooling process is the key to improve the laminar cooling control model, The convective heat transfer coefficient and corresponding surface temperature were calculated by the finite difference method and the inverse heat conduction method. The effects of cooling water jet flow rate on the heat transfer coefficient and surface temperature was investigated when the cooling water jet flow rate varied from 0. 9 to 2, 1 m3 · h -1. It is found that the convective heat transfer coefficient is a nonlinear function of the surface temperature during laminar flow cooling. Within a distance of 70 mm from the stagnation line, the cooling flow rate has no effect on the heat transfer coefficient and surface temperature. But outside 70 mm, the heat transfer coefficient ratio becomes smaller with increasing distance from the stagnation line, It is also shown that relatively good agreement is obtained between the calculated and measured curves.%提高带钢层流冷却控制模型的精度，关键是建立精确的对流换热系数与冷却工艺之间的关系．采用有限差分法和反向热传导法，获得了实验条件下钢板表面的对流换热系数及表面温度．研究了不同水流量（0．9—2．1m3·h-1）对换热系数与表面温度变化规律的影响．在层流冷却过程中，对流换热系数与表面温度呈非线性关系；在距离驻点70mm内，水流量对换热系数随表面温度变化规律没影响；远离驻点70mm外，对流换热系数比随远离冲击区驻点距离的增加而减小．采用所确定的换热系数计算得到的温降曲线与实测曲线吻合较好．
Poisson, A. [Paris-6 Univ., 75 (France); Jean-Baptiste, P. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Direction des Sciences de la Matiere
1994-12-31
In order to study the hypothesis of an under-rating of the exchange velocity at the ocean-atmosphere interface that could explain the lack of CO{sub 2} in the global CO{sub 2} balance, an experiment was carried out in two lakes at the Kerguelen Islands where strong winds are common, in order to evaluate precisely the relation between the transfer coefficient and the wind velocity: {sup 3}He and SF{sub 6} tracers were injected in the lakes; concentration evolutions were recorded and results are shown to validate the above assumption. 6 figs., 1 tab., 9 refs.
Nilsson, Elna Johanna Kristina; Bache-Andreassen, Lihn; Johnson, Matthew Stanley;
2009-01-01
The photolysis rates of HCHO, DCDO, CH3CHO, and CH3CDO are studied by long-path FTIR spectroscopy in natural tropospheric conditions at the European Photoreactor Facility (EUPHORE) in Valencia, Spain. Average relative photolysis rates jHCHO/jDCDO ) 3.15 ( 0.08 and jCH3CHO/jCH3CDO ) 1.26 ( 0...
13 CFR 120.1060 - Confidentiality of Reports, Risk Ratings and related Confidential Information.
2010-01-01
... order prior to disclosure. For purposes of this regulation, “Information Provider” means any contractor... abides by them. Any disclosure of the Report, Risk Rating, or Confidential Information other than as... Confidentiality of Reports, Risk Ratings and related Confidential Information. (a) In general. Reports and other...
THE EVOLUTION OF CURRENCY RELATIONS IN THE LIGHT OF MAJOR EXCHANGE RATE ADJUSTMENT THEORIES
Sergiy TKACH
2014-07-01
Full Text Available This paper examines the impact of major exchange rate adjustment theories on the global monetary system. The reasons of the previous organization forms of monetary relations collapse at the global level are defined. The main achievements and failures of major exchange rate theories are described.
Tomlinson, K.W.; Poorter, L.; Bongers, F.; Borghetti, F.; Jacobs, L.; Langevelde, van F.
2014-01-01
Background and Aims Plant relative growth rate (RGR) depends on biomass allocation to leaves (leaf mass fraction, LMF), efficient construction of leaf surface area (specific leaf area, SLA) and biomass growth per unit leaf area (net assimilation rate, NAR). Functional groups of species may differ in
Properties of Traffic Risk Coefficient
TANG Tie-Qiao; HUANG Hai-Jun; SHANG Hua-Yan; XUE Yu
2009-01-01
We use the model with the consideration of the traffic interruption probability (Physica A 387(2008)6845) to study the relationship between the traffic risk coefficient and the traffic interruption probability.The analytical and numerical results show that the traffic interruption probability will reduce the traffic risk coefficient and that the reduction is related to the density, which shows that this model can improve traffic security.
Drouin, Guy; Daoud, Hanane; Xia, Junnan
2008-12-01
Previous studies have estimated that, in angiosperms, the synonymous substitution rate of chloroplast genes is three times higher than that of mitochondrial genes and that of nuclear genes is twelve times higher than that of mitochondrial genes. Here we used 12 genes in 27 seed plant species to investigate whether these relative rates of substitutions are common to diverse seed plant groups. We find that the overall relative rate of synonymous substitutions of mitochondrial, chloroplast and nuclear genes of all seed plants is 1:3:10, that these ratios are 1:2:4 in gymnosperms but 1:3:16 in angiosperms and that they go up to 1:3:20 in basal angiosperms. Our results show that the mitochondrial, chloroplast and nuclear genomes of seed plant groups have different synonymous substitutions rates, that these rates are different in different seed plant groups and that gymnosperms have smaller ratios than angiosperms.
Frankel, Mika; Bekö, Gabriel; Timm, Michael; Gustavsen, Sine; Hansen, Erik Wind; Madsen, Anne Mette
2012-12-01
Indoor microbial exposure has been related to adverse pulmonary health effects. Exposure assessment is not standardized, and various factors may affect the measured exposure. The aim of this study was to investigate the seasonal variation of selected microbial exposures and their associations with temperature, relative humidity, and air exchange rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m(3)) and were lowest in winter (median, 26 CFU/m(3)). Indoor bacteria peaked in spring (median, 2,165 CFU/m(3)) and were lowest in summer (median, 240 CFU/m(3)). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the mass of inhalable dust and number of particles. Temperature and air exchange rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and air exchange rates were significantly associated with several indoor microbial exposures, they could not fully explain the observed seasonal variations when tested in a mixed statistical model. In conclusion, the season significantly affects indoor microbial exposures, which are influenced by temperature, relative humidity, and air exchange rates.
Variation in cesarean section rates is not related to maternal and neonatal outcomes.
Pallasmaa, Nanneli; Alanen, Anna; Ekblad, Ulla; Vahlberg, Tero; Koivisto, Mari; Raudaskoski, Tytti; Ulander, Veli-Matti; Uotila, Jukka
2013-10-01
The aim of this study was to compare the rate of cesarean sections in 12 delivery units in Finland, and to assess possible associations between cesarean section rates and maternal and neonatal complications. Prospective multicenter cohort study. The 12 largest delivery units in Finland. Total obstetric population between 1 January 2005 and 30 June 2005 (n = 19 764). Prospectively collected data on 2496 cesarean sections and data derived from the Finnish Birth Register on all deliveries in these units were compared. Cesarean section rates and maternal complication rates were adjusted for known risk factors. Cesarean section rate, maternal complications related to cesarean section, and neonatal asphyxia. The cesarean section rates varied significantly between the hospitals (12.9-25.1%, p cesarean section (13.0-36.5%, p cesarean section rate. The differences remained after adjusting for risk factors. Neonatal asphyxia rates varied between 0.14 and 2.8% (p cesarean section rates. The rates of cesarean section, maternal complications and neonatal asphyxia vary markedly between different delivery units. Good maternal and neonatal outcomes can be achieved with cesarean section rates <15%. © 2013 Nordic Federation of Societies of Obstetrics and Gynecology.
Existing and Past Methods of Test and Rating Standards Related to Integrated Heat Pump Technologies
Reedy, Wayne R. [Sentech, Inc.
2010-07-01
This report evaluates existing and past US methods of test and rating standards related to electrically operated air, water, and ground source air conditioners and heat pumps, 65,000 Btu/hr and under in capacity, that potentiality incorporate a potable water heating function. Two AHRI (formerly ARI) standards and three DOE waivers were identified as directly related. Six other AHRI standards related to the test and rating of base units were identified as of interest, as they would form the basis of any new comprehensive test procedure. Numerous other AHRI and ASHRAE component test standards were also identified as perhaps being of help in developing a comprehensive test procedure.
Mental workload measurement: Event-related potentials and ratings of workload and fatigue
Biferno, M. A.
1985-01-01
Event-related potentials were elicited when a digitized word representing a pilot's call-sign was presented. This auditory probe was presented during 27 workload conditions in a 3x3x3 design where the following variables were manipulated: short-term load, tracking task difficulty, and time-on-task. Ratings of workload and fatigue were obtained between each trial of a 2.5-hour test. The data of each subject were analyzed individually to determine whether significant correlations existed between subjective ratings and ERP component measures. Results indicated that a significant number of subjects had positive correlations between: (1) ratings of workload and P300 amplitude, (2) ratings of workload and N400 amplitude, and (3) ratings of fatigue and P300 amplitude. These data are the first to show correlations between ratings of workload or fatigue and ERP components thereby reinforcing their validity as measures of mental workload and fatigue.
The Kauffman Constraint Coefficients Kw
Griggs, Kenneth A
2011-01-01
The Kauffman Constraint Coefficients Kw and their corresponding Elementals Ew are presented as solutions to the construction of the (beta)-derivative of Kauffman's Theta-function. Additionally, a new recursion relation is provided to construct the (beta)-derivative of Theta that requires only operational substitutions and summations; this algorithmically simplifies Kauffman's original technique. To demonstrate Kw, we generate the 30 Kw Coefficients from the corresponding Elementals Ew for the (9)-derivative of Theta and find that our results are in complete agreement with Kauffman's Mathematica\\texttrademark solutions. We further present a calculation of two coefficients for the (12)-derivative of Theta and invite readers to use Mathematica\\texttrademark or any other means to calculate and verify our results. Finally, we present a challenging calculation for a coefficient of the (40)-derivative of Theta; owing to the vast numbers of permutations involved, a Mathematica\\texttrademark approach may require subst...
Energy coefficients for a propeller series
Olsen, Anders Smærup
2004-01-01
The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use of the poten......The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....
Specific cerebellar regions are related to force amplitude and rate of force development.
Spraker, M B; Corcos, D M; Kurani, A S; Prodoehl, J; Swinnen, S P; Vaillancourt, D E
2012-01-16
The human cerebellum has been implicated in the control of a wide variety of motor control parameters, such as force amplitude, movement extent, and movement velocity. These parameters often covary in both movement and isometric force production tasks, so it is difficult to resolve whether specific regions of the cerebellum relate to specific parameters. In order to address this issue, the current study used two experiments and SUIT normalization to determine whether BOLD activation in the cerebellum scales with the amplitude or rate of change of isometric force production or both. In the first experiment, subjects produced isometric pinch-grip force over a range of force amplitudes without any constraints on the rate of force development. In the second experiment, subjects varied the rate of force production, but the target force amplitude remained constant. The data demonstrate that BOLD activation in separate sub-areas of cerebellar regions lobule VI and Crus I/II scales with both force amplitude and force rate. In addition, BOLD activation in cerebellar lobule V and vermis VI was specific to force amplitude, whereas BOLD activation in lobule VIIb was specific to force rate. Overall, cerebellar activity related to force amplitude was located superior and medial, whereas activity related to force rate was inferior and lateral. These findings suggest that specific circuitry in the cerebellum may be dedicated to specific motor control parameters such as force amplitude and force rate.
Abnormalities in Automatic Processing of Illness-Related Stimuli in Self-Rated Alexithymia.
Laura Brandt
Full Text Available To investigate abnormalities in automatic information processing related to self- and observer-rated alexithymia, especially with regard to somatization, controlling for confounding variables such as depression and affect.89 healthy subjects (60% female, aged 19-71 years (M = 32.1. 58 subjects were additionally rated by an observer.Alexithymia (self-rating: TAS-20, observer rating: OAS; automatic information processing (priming task including verbal [illness-related, negative, positive, neutral] and facial [negative, positive, neutral] stimuli; somatoform symptoms (SOMS-7T; confounders: depression (BDI, affect (PANAS.Higher self-reported alexithymia scores were associated with lower reaction times for negative (r = .19, p < .10 and positive (r = .26, p < .05 verbal primes when the target was illness-related. Self-reported alexithymia was correlated with number (r = .42, p < .01 and intensity of current somatoform symptoms (r = .36, p < .01, but unrelated to observer-rated alexithymia (r = .11, p = .42.Results indicate a faster allocation of attentional resources away from task-irrelevant information towards illness-related stimuli in alexithymia. Considering the close relationship between alexithymia and somatization, these findings are compatible with the theoretical view that alexithymics focus strongly on bodily sensations of emotional arousal. A single observer rating (OAS does not seem to be an adequate alexithymia-measure in community samples.
Wave Reflection Coefficient Spectrum
俞聿修; 邵利民; 柳淑学
2003-01-01
The wave reflection coefficient frequency spectrum and directional spectrum for concrete face slope breakwaters and rubble mound breakwaters are investigated through physical model tests in the present study. The reflection coefficients of oblique irregular waves are analyzed by the Modified Two-Point Method (MTPM) proposed by the authors. The results show that the wave reflection coefficient decreases with increasing wave frequency and incident angle or decreasing structure slope. The reflection coefficient frequency spectrum and its variation with Iribarren number are given in this paper. The paper also suggests an empirical 3-dimensional reflection coefficient spectrum, i.e. reflection coefficient directional spectrum, which can be used to illustrate quantitatively the variation of reflection coefficient with the incident angle and the Iribarren number for oblique irregular waves.
Plašil, Radek; Dohnal, Petr; Kálosi, Ábel; Roučka, Štěpán; Johnsen, Rainer; Glosík, Juraj
2017-03-01
We report measurements of the binary and ternary recombination rate coefficients of deuterated isotopologues of {{{H}}}3+. A cavity ring-down absorption spectrometer was used to monitor the fractional abundances of {{{H}}}3+, {{{H}}}2{{{D}}}+, {{HD}}2+ and {{{D}}}3+ during the decay of a plasma in He/Ar/{{{H}}}2/{{{D}}}2 mixtures. A dependence of the measured effective recombination rate coefficients on the helium buffer gas density was observed and hence both the binary and the ternary recombination rate coefficients for {{{H}}}2{{{D}}}+ and {{HD}}2+ were obtained in the temperature range 80–145 K.
Simone, Angela; Kolarik, Jakub; Iwamatsu, Toshiya
2011-01-01
. Generally, the relationship between air temperature and the exergy consumption rate, as a first approximation, shows an increasing trend. Taking account of both convective and radiative heat exchange between the human body and the surrounding environment by using the calculated operative temperature, exergy...... consumption rates increase as the operative temperature increases above 24 ◦C or decreases below 22 ◦C. With the data available so far, a second-order polynomial relationship between thermal sensation and the exergy consumption rate was established....... occupants, it is reasonable to consider both the exergy flows in building and those within the human body. Until now, no data have been available on the relation between human-body exergy consumption rates and subjectively assessed thermal sensation. The objective of the present work was to relate thermal...
Relation between the compaction rate and physical and mechanical properties of particleboards
Fabricio Moura Dias
2005-09-01
Full Text Available The compaction rate, the relation between the density of the wood panel and the density of the wood used for producing the particles, is an indicator of the product's densification. Among the various types of wood panels, particleboards are widely employed in the lumber industry, mainly for the furniture production. This paper presents a study of the relation between the compaction rate and the properties of tensile strength perpendicular to surface, Modulus of Rupture (MOR and Modulus of Elasticity (MOE obtained from a static bending test, thickness swelling and water absorption (2 and 24 hours. These properties were calculated according to the Brazilian ABNT, NBR 14810 standard. Particleboards were produced using the species Pinus elliotti and adhesive ureaformaldehyde. The relation was established by a multiple linear regression, and the most appropriate statistical models were determined. The estimated models indicate statistically significant effects of water absorption in 2 hours and MOR in the particleboards' compaction rate.
论基尼系数与居民个人收入分配的关系%Study on Relation Between Gini Coefficient and Income Distribution
周德海
2012-01-01
In the academic circle,Gini Coefficient is usually viewed as measurement for equality or inequality in income distribution. Such a concept is a misunderstanding of the relationship between Gini Coefficient and income distribution, a low or high Gini Coefficient doesn't necessarily represent whether income distribution is equal or inequal.The principle of exchange of equal value is the objective standard in measuring whether income distribution is equal or inequal.%学术界通常以基尼系数的大小作为衡量居民个人收入分配是否公平的依据,这是对基尼系数与居民个人收入分配之间关系的误解。一个国家基尼系数的大小,与这个国家居民的个人收入分配是否公平没有关系。马克思经济学的等价交换原则是衡量居民个人收入分配是否公平的客观标准。
Flow rate-pressure drop relation for deformable shallow microfluidic channels
Christov, Ivan C.; Cognet, Vincent; Stone, Howard A.
2013-11-01
Laminar flow in devices fabricated from PDMS causes deformation of the passage geometry, which affects the flow rate-pressure drop relation. Having an accurate flow rate-pressure drop relation for deformable microchannels is of importance given that the flow rate for a given pressure drop can be as much as 500% of the flow rate predicted by Poiseuille's law for a rigid channel. proposed a successful model of the latter phenomenon by heuristically coupling linear elasticity with the lubrication approximation for Stokes flow. However, their model contains a fitting parameter that must be found for each channel shape by performing an experiment. We present a perturbative derivation of the flow rate-pressure drop relation in a shallow deformable microchannel using Kirchoff-Love theory of isotropic quasi-static plate bending and Stokes' equations under a ``double lubrication'' approximation (i.e., the ratio of the channel's height to its width and of the channel's width to its length are both assumed small). Our result contains no free parameters and confirms Gervais et al.'s observation that the flow rate is a quartic polynomial of the pressure drop. ICC was supported by NSF Grant DMS-1104047 and the U.S. DOE through the LANL/LDRD Program; HAS was supported by NSF Grant CBET-1132835.
MULTIVARIATE VARYING COEFFICIENT MODEL FOR FUNCTIONAL RESPONSES.
Zhu, Hongtu; Li, Runze; Kong, Linglong
2012-10-01
Motivated by recent work studying massive imaging data in the neuroimaging literature, we propose multivariate varying coefficient models (MVCM) for modeling the relation between multiple functional responses and a set of covariates. We develop several statistical inference procedures for MVCM and systematically study their theoretical properties. We first establish the weak convergence of the local linear estimate of coefficient functions, as well as its asymptotic bias and variance, and then we derive asymptotic bias and mean integrated squared error of smoothed individual functions and their uniform convergence rate. We establish the uniform convergence rate of the estimated covariance function of the individual functions and its associated eigenvalue and eigenfunctions. We propose a global test for linear hypotheses of varying coefficient functions, and derive its asymptotic distribution under the null hypothesis. We also propose a simultaneous confidence band for each individual effect curve. We conduct Monte Carlo simulation to examine the finite-sample performance of the proposed procedures. We apply MVCM to investigate the development of white matter diffusivities along the genu tract of the corpus callosum in a clinical study of neurodevelopment.
Self-rated health as a comprehensive indicator of lifestyle-related health status.
Yamada, Chizumi; Moriyama, Kengo; Takahashi, Eiko
2012-11-01
To evaluate the usefulness of self-rated health (SRH) as a comprehensive indicator of lifestyle-related health status by examining the relationships between SRH and: (1) history of cancer and cardiovascular disease; (2) treatment of hypertension, diabetes, and dyslipidemia; (3) abnormalities in clinical parameters including blood pressure, fasting glucose, and lipids; and (4) lifestyle habits. 3744 health-check examinees at Tokai University Hachioji Hospital seen between April 2009 and March 2010 were enrolled. SRH was graded as "good," "relatively good," "relatively poor," or "poor." For statistical comparison, the differences among "healthy" (=good), "relatively healthy" (=relatively good), and "unhealthy" (=relatively poor plus poor) groups were examined. Mantel-Haenszel odds ratios were calculated to remove the confounding effect of age, using the healthy group as the reference. The Mantel-extension method was used as a trend test. 1049 subjects rated their health as good, 2194 as relatively good, 428 as relatively poor, and 73 as poor. The prevalence of all diseases showed significant odds ratios and trends as SRH deteriorated. Obesity, blood pressure, glucose metabolism, and lipids deteriorated significantly as SRH became poorer, and a trend was observed in all parameters. Weight change, exercise, smoking, and rest showed significant odds ratios and trends as SRH deteriorated. SRH appears useful as a comprehensive indicator of lifestyle-related health status.
Index-free Heat Kernel Coefficients
De van Ven, A E M
1998-01-01
Using index-free notation, we present the diagonal values of the first five heat kernel coefficients associated with a general Laplace-type operator on a compact Riemannian space without boundary. The fifth coefficient appears here for the first time. For a flat space with a gauge connection, the sixth coefficient is given too. Also provided are the leading terms for any coefficient, both in ascending and descending powers of the Yang-Mills and Riemann curvatures, to the same order as required for the fourth coefficient. These results are obtained by directly solving the relevant recursion relations, working in Fock-Schwinger gauge and Riemann normal coordinates. Our procedure is thus noncovariant, but we show that for any coefficient the `gauged' respectively `curved' version is found from the corresponding `non-gauged' respectively `flat' coefficient by making some simple covariant substitutions. These substitutions being understood, the coefficients retain their `flat' form and size. In this sense the fift...
Does the growth rate of total amount in cash salaries relate to a transition in the suicide rate?
Inoue, Ken; Fukunaga, Tatsushige; Okazaki, Yuji
2012-01-01
... annual suicide rates by vital statistics and annual growth rates of total amount in cash salary from 1995 to 2009 in Japan, and we assessed the correlation between these factors during that period using single regression analysis in an excel (Microsoft, Japanese, made in Singapore) spreadsheet. During the study period, the annual suicide rates (/10...
Kang, Myung Ja; Lee, Haejung
2006-08-01
The purpose of this study was to investigate the effects of assertiveness training on nurses' assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate. A non-equivalent control group pretest-posttest design was used in this study. Nurses were assigned into the experimental or control groups, each consisting of 39 nurses. Data was collected between January to March 2004. An 'Assertiveness Training Program' for Nurses developed by Park was used for the study. To emphasize assertiveness practice, 5 practice sessions utilizing ABCDE principles were added to Park's program. To examine the effects of the program, differences between the two groups in assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate were analyzed using ANCOVA. The assertiveness training was effective in improving the nurses' assertiveness behaviors, but was not effective in improving interpersonal relations, reducing the subjects' communication conflicts, changing the conflict management style or reducing their personnel turnover rate. There have been many studies about factors affecting nurses' personnel turnover rates, but few have been done about methods of intervention to reduce the personnel turnover rate. Thus, this study provides a significant contribution in attempting such an intervention from nursing management perspectives.
Ralph E Schmidt
Full Text Available To examine the association between healthcare-related regrets and sleep difficulties among nurses and physicians, we surveyed 240 nurses and 220 physicians at the University Hospitals of Geneva. Regret intensity and regret coping were measured using validated scales. Sleep difficulties were measured using the Insomnia Severity Index (ISI, and an additional question assessed the frequency of sleeping pill use. After controlling for sex, profession, years of experience, rate of employment, and depression as well as for all other regret-related variables, the following variables remained significantly associated with self-rated severity of insomnia: regret intensity (slope = 1.32, p = 0.007, 95%CI: [0.36; 2.29], std. coefficient = 0.16 and maladaptive (e.g., rumination emotion-focused coping (slope = 1.57, p = 0.002, 95%CI: [0.60; 2.55], std. coefficient = 0.17 remained significant predictors of self-rated insomnia severity. If these cross-sectional associations represent causal effects, the development of regret-management programs may represent a promising approach to mitigating sleep difficulties of healthcare professionals.
Resting metabolic rate in Italians : relation with body composition and anthropometric parameters
Lorenzo, de A.; Andreoli, A.; Bertoli, S.; Testolin, G.; Oriani, G.; Deurenberg, P.
2000-01-01
The objectives of this study were to obtain values for resting metabolic rate in Italians in relation to parameters of body composition, and to compare them to predicted values using the FAO/WHO/UNU equation. We performed a cross-sectional observational study of 131 healthy subjects (46 males and 85
Gomez-Guerrero, Lorena; Martin, Cristina Dominguez; Mairena, Maria Angeles; Di Martino, Adriana; Wang, Jing; Mendelsohn, Alan L.; Dreyer, Benard P.; Isquith, Peter K.; Gioia, Gerard; Petkova, Eva; Castellanos, F. Xavier
2011-01-01
Objective: Individuals with ADHD are often characterized as inconsistent across many contexts. ADHD is also associated with deficits in executive function. We examined the relationships between response time (RT) variability on five brief computer tasks to parents' ratings of ADHD-related features and executive function in a group of children with…
Hare, Mary; Tanenhaus, Michael K.; McRae, Ken
2007-01-01
Two rating studies demonstrate that English speakers willingly produce reduced relatives with internal cause verbs (e.g., "Whisky fermented in oak barrels can have a woody taste"), and judge their acceptability based on factors known to influence ambiguity resolution, rather than on the internal/external cause distinction. Regression analyses…
The Radio Continuum-Star Formation Rate Relation in WSRT SINGS Galaxies
Heesen, Volker; Brinks, Elias; Leroy, Adam K.; Heald, George; Braun, Robert; Bigiel, Frank; Beck, Rainer
We present a study of the spatially resolved radio continuum-star formation rate (RC-SFR) relation using state-of-the-art star formation tracers in a sample of 17 THINGS galaxies. We use SFR surface density (ΣSFR) maps created by a linear combination of GALEX far-UV (FUV) and Spitzer 24 μm maps. We
Ohme, Melanie; Zacher, Hannes
2015-01-01
According to career construction theory, continuous adaptation to the work environment is crucial to achieve work and career success. In this study, we examined the relative importance of career adaptability for job performance ratings using an experimental policy-capturing design. Employees (N = 13
The Radio Continuum-Star Formation Rate Relation in WSRT SINGS Galaxies
Heesen, Volker; Brinks, Elias; Leroy, Adam K.; Heald, George; Braun, Robert; Bigiel, Frank; Beck, Rainer
2014-01-01
We present a study of the spatially resolved radio continuum-star formation rate (RC-SFR) relation using state-of-the-art star formation tracers in a sample of 17 THINGS galaxies. We use SFR surface density (ΣSFR) maps created by a linear combination of GALEX far-UV (FUV) and Spitzer 24 μm maps. We
Absolute and Relative Reliability of Percentage of Syllables Stuttered and Severity Rating Scales
Karimi, Hamid; O'Brian, Sue; Onslow, Mark; Jones, Mark
2014-01-01
Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…
The Acquisition of Vector Knowledge and Its Relation to Self-Rated Direction Sense
Muehl, Karen A.; Sholl, M. Jeanne
2004-01-01
Self-rated sense of direction is reliably related to people's accuracy when pointing in the direction of unseen landmarks from imagined or actual perspectives. It is proposed that the cognitive substrate of accurate pointing responses is a vector representation, which is defined as an integrated network of displacement vectors. Experiment 1…
Resting metabolic rate in Italians : relation with body composition and anthropometric parameters
Lorenzo, de A.; Andreoli, A.; Bertoli, S.; Testolin, G.; Oriani, G.; Deurenberg, P.
2000-01-01
The objectives of this study were to obtain values for resting metabolic rate in Italians in relation to parameters of body composition, and to compare them to predicted values using the FAO/WHO/UNU equation. We performed a cross-sectional observational study of 131 healthy subjects (46 males and 85
An estimator for the relative entropy rate of path measures for stochastic differential equations
Opper, Manfred
2017-02-01
We address the problem of estimating the relative entropy rate (RER) for two stochastic processes described by stochastic differential equations. For the case where the drift of one process is known analytically, but one has only observations from the second process, we use a variational bound on the RER to construct an estimator.
Hillman, Nicholas W.; Orians, Erica Lee
2013-01-01
This study uses fixed-effects panel data techniques to estimate the elasticity of community college enrollment demand relative to local unemployment rates. The findings suggest that community college enrollment demand is counter-cyclical to changes in the labor market, as enrollments rise during periods of weak economic conditions. Using national…
Freisthler, Bridget; Needell, Barbara; Gruenewald, Paul J.
2005-01-01
Objective: This study examines how the availability of alcohol and illicit drugs (as measured by alcohol outlet density and police incidents of drug sales and possessions) is related to neighborhood rates of child abuse and neglect, controlling for other neighborhood demographic characteristics. Method: Data from substantiated reports of child…
Development in self-rated health among older people as determinant of social relations
Avlund, Kirsten; Modvig, Jens Simon; Due, Pernille;
2004-01-01
The purpose of this study was to analyse whether development in self-rated health (SRH) over four years was associated with the structure of and satisfaction with social relations, at four and eight years follow-up, among elderly women and men....
Citation Rate of Highly-Cited Papers in 100 Kinesiology-Related Journals
Knudson, Duane
2015-01-01
This study extended previous research on several citation-based bibliometric variables for highly cited articles in a large (N = 100) number of journals related to Kinesiology. Total citations and citation rate of the 30 most highly cited articles in each journal were identified by searchers of "Google Scholar (GS)". Other major…
The relations between personality traits and psychopathy as measured by ratings and self-report
Kujačić Daliborka
2015-01-01
Full Text Available The objective of this study was to examine the relations between psychopathy - as assessed by ratings (PCL-R and by self-report (SRP3 - on one side, and The Five-Factor personality Model - expanded to include the traits Amorality and Disintegration - on the other. Both methods examined four traits of psychopathy: interpersonal, affective, lifestyle and antisocial characteristics. Data were collected on a sample of 112 male convicts. The results show the absence of congruence between the two methods - self-report and rating - in case of interpersonal and affective psychopathic dispositions. This incongruence is also reflected in their relations with personality traits. The self-report measures and the ratings of Lifestyle and Antisocial tendencies are related to amorality, aggressiveness, schizotypy, Neuroticism and impulsivity. However, the ratings of affective and interpersonal style are related to the integrated, organized, and emotionally stable aspects of personality. The results are interpreted in the light of differences between the methods of assessment and in the light of the essential characteristics of the psychopathic phenomena.
Citation Rate of Highly-Cited Papers in 100 Kinesiology-Related Journals
Knudson, Duane
2015-01-01
This study extended previous research on several citation-based bibliometric variables for highly cited articles in a large (N = 100) number of journals related to Kinesiology. Total citations and citation rate of the 30 most highly cited articles in each journal were identified by searchers of "Google Scholar (GS)". Other major…
Background seismicity rate at subduction zones linked to slab-bending-related hydration
Nishikawa, Tomoaki; Ide, Satoshi
2015-09-01
Tectonic properties strongly control variations in seismicity among subduction zones. In particular, fluid distribution in subduction zones influences earthquake occurrence, and it varies among subduction zones due to variations in fluid sources such as hydrated oceanic plates. However, the relationship between variations in fluid distribution and variations in seismicity among subduction zones is unclear. Here we divide Earth's subduction zones into 111 regions and estimate background seismicity rates using the epidemic type aftershock sequence model. We demonstrate that background seismicity rate correlates to the amount of bending of the incoming oceanic plate, which in turn is related to the hydration of oceanic plates via slab-bending-related faults. Regions with large bending may have high-seismicity rates because a strongly hydrated oceanic plate causes high pore fluid pressure and reduces the strength of the plate interface. We suggest that variations in fluid distribution can also cause variations in seismicity in subduction zones.
Seismic hazard related to rate of face advance in Lubin copper ore mine
Anna Gogolewska
2013-09-01
Full Text Available Seismic hazard was depicted by means of seismic activity. The rate of face advance was defined as the output-energy ratio (J/kg and as the distance in meters, which the face overcomes in a given time (for example six months. Seismic activity was analyzed in relation to such the rates of face advance. The analyses were performed for two mining districts (G-7 and G-8 of Lubin copper ore mine. The period of 2008-2009 years was taken into account. In both mining districts the outputenergy ratio did not show any strict connection between the rate of face advance and seismic activity. Whilst seismic hazard increased with increasing rate of face advance defined as the distance between two sequential positions of face in most panels of the two mining districts.
State-related differences in heart rate variability in bipolar disorder
Faurholt-Jepsen, Maria; Brage, Søren; Kessing, Lars Vedel
2017-01-01
Heart rate variability (HRV) is a validated measure of sympato-vagal balance in the autonomic nervous system. HRV appears decreased in patients with bipolar disorder (BD) compared with healthy individuals, but the extent of state-related alterations has been sparingly investigated. The present...... study examined differences in HRV between affective states in BD. A heart rate and movement sensor weighing 8 g collected average acceleration, heart rate and the two slowest and fastest heart beats (of the most recent 16 beats) every 30 s over a period of at least three consecutive weekdays and nights...... data-points. In unadjusted analyses and in analyses adjusted for age, gender and heart rate, during a manic state HRV was increased by 18% compared with a depressed state (e(B) = 1.18, 95% CI: 1.16-1.20, p
Investigating the Existence of Chaos in Inflation Data in relation to Chaotic Foreign Exchange Rate
Pritha Das
2014-01-01
Full Text Available Foreign exchange (ForEx rates are amongst the most important economic indices in the international monetary markets. ForEx rate represents the value of one currency in another and it fluctuates over time. It is related to indicators like inflation, interest rate, gross domestic product, and so forth. In a series of works, we investigated and confirmed the chaotic property of ForEx rates by finding positive largest Lyapunov exponent (LLE. As inflation influences ForEx, in this work we would like to address the specific question, Is inflation data also chaotic? We collected data for time period of 2000 to 2013 and tested for nonlinearity in data by surrogate method. Calculating LLE, we find existence of chaos in inflation data for some countries.
Bars-Closel, Melissa; Kohlsdorf, Tiana; Moen, Daniel S; Wiens, John J
2017-09-01
Patterns of species richness among clades can be directly explained by the ages of clades or their rates of diversification. The factors that most strongly influence diversification rates remain highly uncertain, since most studies typically consider only a single predictor variable. Here, we explore the relative impacts of macroclimate (i.e., occurring in tropical vs. temperate regions) and microhabitat use (i.e., terrestrial, fossorial, arboreal, aquatic) on diversification rates of squamate reptile clades (lizards and snakes). We obtained data on microhabitat, macroclimatic distribution, and phylogeny for >4000 species. We estimated diversification rates of squamate clades (mostly families) from a time-calibrated tree, and used phylogenetic methods to test relationships between diversification rates and microhabitat and macroclimate. Across 72 squamate clades, the best-fitting model included microhabitat but not climatic distribution. Microhabitat explained ∼37% of the variation in diversification rates among clades, with a generally positive impact of arboreal microhabitat use on diversification, and negative impacts of fossorial and aquatic microhabitat use. Overall, our results show that the impacts of microhabitat on diversification rates can be more important than those of climate, despite much greater emphasis on climate in previous studies. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
Barseghyan, Manuk G; Restrepo, Ricardo L; Mora-Ramos, Miguel E; Kirakosyan, Albert A; Duque, Carlos A
2012-09-28
: The linear and nonlinear intraband optical absorption coefficients in GaAs three-dimensional single quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and electric field, applied along the growth direction of the heterostructure, the energies of the ground and first excited states of a donor impurity have been found using the effective mass approximation and a variational method. The energies of these states are examined as functions of the dimensions of the structure, electric field, and hydrostatic pressure. We have also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as a function of incident photon energy for several configurations of the system. It is found that the variation of distinct sizes of the structure leads to either a redshift and/or a blueshift of the resonant peaks of the intraband optical spectrum. In addition, we have found that the application of an electric field leads to a redshift, whereas the influence of hydrostatic pressure leads to a blueshift (in the case of on-ring-center donor impurity position) of the resonant peaks of the intraband optical spectrum.
Vartanian, A. L.; Asatryan, A. L.; Vardanyan, L. A.
2017-03-01
We have investigated the influence of an image charge effect (ICE) on the energies of the ground and first few excited states of a hydrogen-like impurity in a spherical quantum dot (QD) in the presence of an external electric field. The oscillator strengths of transitions from the 1 s -like state to excited states of 2px and 2pz symmetries are calculated as the functions of the strengths of the confinement potential and the electric field. Also, we have studied the effect of image charges on linear and third-order nonlinear optical absorption coefficients and refractive index changes (RICs). The results show that image charges lead to the decrease of energies for all the hydrogen-like states, to the significant enhancement of the oscillator strengths of transitions between the impurity states, and to comparatively large blue shifts in linear, nonlinear, and total absorption coefficients and refractive index changes. Our results indicate that the total optical characteristics can be controlled by the strength of the confinement and the electric field.
Effective Viscosity Coefficient of Nanosuspensions
Rudyak, V. Ya.; Belkin, A. A.; Egorov, V. V.
2008-12-01
Systematic calculations of the effective viscosity coefficient of nanosuspensions have been performed using the molecular dynamics method. It is established that the viscosity of a nanosuspension depends not only on the volume concentration of the nanoparticles but also on their mass and diameter. Differences from Einstein's relation are found even for nanosuspensions with a low particle concentration.
Relative deprivation in income and self-rated health in the United States.
Subramanyam, Malavika; Kawachi, Ichiro; Berkman, Lisa; Subramanian, S V
2009-08-01
Absolute income is robustly associated with health status. Few studies have, however, examined if relative income is independently associated with health. We examined if, over and above the effects of absolute income, individual relative deprivation in income as well as position in the income hierarchy is associated with individual poor health in the U.S. Using three rounds of the Current Population Surveys (CPS), we analyzed the association between self-rated health (1=fair/poor, 0=otherwise) and the Yitzhaki index of relative deprivation in income and percentile position in the income hierarchy across 17 reference groups. Over and above the effects of absolute income, the odds ratio for reporting poor health among individuals in the highest quintile of relative deprivation compared to the lowest quintile ranged between 2.18 and 3.30, depending on the reference groups used. A 10 percentile increase in income position within reference groups was associated with an odds ratio of poor health of 0.89. Relative deprivation appeared to explain between 33 and 94% of the association between individual income and self-rated health. Relative deprivation in income is independently associated with poor health over and above the well established effects of absolute income on health. Relative deprivation may partly explain the association between income inequality and worse population health status.
Mihara, Yuichi; Inoue, Tatsuaki; Yokota, Katsushi
2005-02-01
In this study, the elucidation of the toxicity mechanism was undertaken regarding the IC(50) of the oxygen uptake rate (OUR) with relevance to the biosorption as a toxicity evaluation of chemical substances for activated sludge (AS). At the IC(50) oflinear alkyl benzene sulfonate (LAS), alkyl ethoxy sulfonate (AES), alpha-olefine sulfonate (AOS), sodium dodecyl sulfate (SDS), formaldehyde (FA), benzalkonium chloride (BZaC), benzethonium chloride (BZeC), rhodamine 6G (R-6G) and fuchsine (Fuc) in which the IC(50) belonged to the 100-1000 mg/l group, when it was compared with CV and MG. In ethanol (EtOH), isopropanol (PrOH), nile blue (NB), evans blue (EB), methylene blue (MB), methyl orange (MO), paraquat (PQ), chlorophyllin (Chl) and auramine (Aur), the IC(50) was large, and the biosorption of AS was weak at 0-15%. The biosorption of MG for AS followed the adsorption isotherm equation Y=0.002X(0.511) of Freundrich. The correlation coefficient was gamma=0.998 (n=8), and a very high correlation was obtained. In the qualitative OUR curve by AS pretreated with MG or CV which belonged to the IC(50) small group, the inhibition of remarkable OUR was observed. Therefore, the findings of the present investigation suggest that the inhibition of the OUR for AS by the tested chemical substances was markedly affected by the biosorption.
Frankel, Mika; Bekö, Gabriel; Timm, Michael;
2012-01-01
inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m3) and were lowest in winter (median, 26 CFU/m3). Indoor...... bacteria peaked in spring (median, 2,165 CFU/m3) and were lowest in summer (median, 240 CFU/m3). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the mass...
Harmonic functions with varying coefficients
Jacek Dziok
2016-05-01
Full Text Available Abstract Complex-valued harmonic functions that are univalent and sense preserving in the open unit disk can be written in the form f = h + g ‾ $f=h+\\overline{g}$ , where h and g are analytic. In this paper we investigate some classes of univalent harmonic functions with varying coefficients related to Janowski functions. By using the extreme points theory we obtain necessary and sufficient convolution conditions, coefficients estimates, distortion theorems, and integral mean inequalities for these classes of functions. The radii of starlikeness and convexity for these classes are also determined.
Gebraegziabher, Habtamu Giday; Kjær, Katrine Heinsvig; Ottosen, Carl-Otto
2015-01-01
a given cultivar, Tleaf was generally higher, (1.5-3.7°C) at high as compared to moderate RH. Following desiccation, leaf weight loss was differentially enhanced (8-66%) in high RH-grown plants, indicating a wide variation in high RH tolerance. High RH mainly decreased plant water loss during the light......Plants grown at high relative air humidity (RH) often show disturbed water relations due to less responsive stomata. The attenuation of stomatal responsiveness as a result of high RH during leaf expansion depends on the cultivar. We hypothesized that tolerant cultivars to high RH experience a lower...... decline in plant transpiration by high RH, and that the variation in plant transpiration rate can be reflected by differences in leaf temperature (Tleaf). Plant leaf area, stomatal responsiveness to desiccation, together with plant transpiration and leaf temperature at growth conditions were analyzed...
Møller, S.; Sternberg, Claus; Poulsen, L. K.
1995-01-01
species-specific hybridizations with fluorescence-labelled ribosomal probes to estimate the single-cell concentration of RNA. By automated analysis of digitized images of stained cells, we determined four independent growth rate-related parameters: cellular RNA and DNA contents, cell volume......, and the frequency of dividing cells in a cell population. These parameters were used to compare physiological states of liquid-suspended and surfacegrowing Pseudomonas putida KT2442 in chemostat cultures. The major finding is that the correlation between substrate availability and cellular growth rate found...
Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de
2004-01-01
Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5)
Riese, H.; Doornen, L.J.P. van; Houtman, I.L.D.; Geus, E.J.C. de
2004-01-01
Objective. This study examined the effects of exposure to job strain on independent predictors of cardiovascular disease (ambulatory blood pressure, heart rate, and heart rate variability). Methods. The participants comprised a homogeneous group of 159 healthy female nurses [mean age 35.9 (SD 8.5) y
Vulnerability of Louisiana's coastal wetlands to present-day rates of relative sea-level rise
Jankowski, Krista L.; Törnqvist, Torbjörn E.; Fernandes, Anjali M.
2017-03-01
Coastal Louisiana has lost about 5,000 km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world's highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion and shallow subsidence rates. Comparison of vertical accretion rates with RSLR rates at the land surface (present-day RSLR rates are 12+/-8 mm per year) shows that 65% of wetlands in the Mississippi Delta (SE Louisiana) may keep pace with RSLR, whereas 58% of the sites in the Chenier Plain (SW Louisiana) do not, rendering much of this area highly vulnerable to RLSR. At least 60% of the total subsidence rate occurs within the uppermost 5-10 m, which may account for the higher vulnerability of coastal Louisiana wetlands compared to their counterparts elsewhere.
Dijkstra, P; Reegen, H; Kuiper, P J
1990-08-01
Relationships between relative growth rate (RGR), endogenous gibberellin (GA) concentration and the response to application of gibberellic acid (GA(3) ) were studied for two inbred lines of Plantago major L., which differed in RGR. A4, the fast-growing inbred line, had a higher free GA concentration than the slow-growing W9, as analyzed by enzyme immunoassay. GA(3) application increased total plant weight and RGR(3) particularly for the slow-growing line. Chlorophyll a content and photosynthetic activity per unit leaf area were decreased, while transpiration rate was unaffected by GA(3) application. The increase in RGR by GA(3) application was associated with an increased leaf weight ratio; specific leaf area and percentage of dry matter in the leaves were only temporarily affected. Root respiration rate per unit dry weight was unaffected. The correlation between low RGR, low GA concentration and high responsiveness to applied GA(3) supports the contention that gibberellins are involved in the regulation of RGR. However, the transient influence of GA(3) application on some growth components suggests the involvement of other regulatory factors in addition to GA.
Influence of water relations and growth rate on plant element uptake and distribution
Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany
2006-02-15
Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution.
Transport Coefficients of Fluids
Eu, Byung Chan
2006-01-01
Until recently the formal statistical mechanical approach offered no practicable method for computing the transport coefficients of liquids, and so most practitioners had to resort to empirical fitting formulas. This has now changed, as demonstrated in this innovative monograph. The author presents and applies new methods based on statistical mechanics for calculating the transport coefficients of simple and complex liquids over wide ranges of density and temperature. These molecular theories enable the transport coefficients to be calculated in terms of equilibrium thermodynamic properties, and the results are shown to account satisfactorily for experimental observations, including even the non-Newtonian behavior of fluids far from equilibrium.
Reynders, Alexandre; Kerkhof, Ad J F M; Molenberghs, Geert; Van Audenhove, Chantal
2016-02-01
In this ecological study, we investigated whether help-seeking related to stigma, intentions, and attitudes toward suicide are associated with the suicide rates of 20 regions within the Netherlands and Belgium. Significant associations were found between regional suicide rates and the intention to seek informal help (β = -1.47, p = .001), self-stigma (β = 1.33, p = .038), and shame (β = .71, p = .030). The association between self-stigma and suicide rate was mediated by intentions to seek informal help. These results suggest that to promote suicide prevention at the level of the regional population, stigma, shame, and intentions to seek help should be targeted in the public domain.
Relation of eye dominance with performance and subjective ratings in golf putting.
Sugiyama, Yoshio; Lee, Mi-Sook
2005-06-01
Previous research has discussed the interaction of hand preference, eye dominance, and sport performance. In this study, the relation of eye dominance with performance and subjective ratings in golf putting was investigated. 47 right-handed Japanese students from a college of physical education putted 10 balls to a drawn circle 3 m away, each under right-handed and left-handed stance conditions. Putting performance was measured by the number of successful putts. After putting in each condition, they rated subjective visibility and feelings of hitting. Analyses indicated that right-eyed subjects had significantly better performance using the right-handed stance than the left-handed stance, whereas left-eyed subjects showed the opposite. Most subjective ratings were more positive with right-handed stance for both right-eyed and left-eyed subjects. These findings suggest that eye dominance could have some influence on putting performance of Japanese novice golfers.
The impact of varicella vaccination on varicella-related hospitalization rates: global data review
Hirose, Maki; Gilio, Alfredo Elias; Ferronato, Angela Esposito; Ragazzi, Selma Lopes Betta
2016-01-01
Abstract Objective: To describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. Data source: We identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination) in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or) "hospitalization". Publications in English published between January 1995 and May 2015 were included. Data synthesis: 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4%–99.2% reduction in hospitalization rates in children younger than four years, 6–14 years after the onset of universal vaccination (1995), with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1–4 years) in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1–4 years) in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1–4 years) in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1–4 years) in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years) in four years, coverage of 77.2% and Italy 69.7%–73.8% decrease (general population), coverage of 60%–95%. Conclusions: The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between data. PMID
The impact of varicella vaccination on varicella-related hospitalization rates: global data review
Maki Hirose
Full Text Available Abstract Objective: To describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. Data source: We identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or "hospitalization". Publications in English published between January 1995 and May 2015 were included. Data synthesis: 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4%–99.2% reduction in hospitalization rates in children younger than four years, 6–14 years after the onset of universal vaccination (1995, with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1–4 years in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1–4 years in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1–4 years in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1–4 years in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years in four years, coverage of 77.2% and Italy 69.7%–73.8% decrease (general population, coverage of 60%–95%. Conclusions: The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between
The impact of varicella vaccination on varicella-related hospitalization rates: global data review.
Hirose, Maki; Gilio, Alfredo Elias; Ferronato, Angela Esposito; Ragazzi, Selma Lopes Betta
2016-09-01
to describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. we identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination) in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or) "hospitalization". Publications in English published between January 1995 and May 2015 were included. 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4% -99.2% reduction in hospitalization rates in children younger than four years after 6-14 years after the onset of universal vaccination (1995), with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1-4 years) in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1-4 years) in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1-4 years) in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1-4 years) in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years) in four years, coverage of 77.2% and Italy 69.7% -73.8% decrease (general population), coverage of 60%-95%. The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between data. Copyright © 2016 Sociedade de Pediatria de São Paulo. Publicado por
Telford, O Grace; Skillman, Evan D; Conroy, Charlie
2016-01-01
There is evidence that the well-established mass-metallicity relation in galaxies is correlated with a third parameter: star formation rate (SFR). The strength of this correlation may be used to disentangle the relative importance of different physical processes (e.g., infall of pristine gas, metal-enriched outflows) in governing chemical evolution. However, all three parameters are susceptible to biases that might affect the observed strength of the relation between them. We analyze possible sources of systematic error, including sample bias, application of S/N cuts on emission lines, choice of metallicity calibration, uncertainty in stellar mass determination, aperture effects, and dust. We present the first analysis of the relation between stellar mass, gas phase metallicity, and SFR using strong line abundance diagnostics from Dopita et al. (2013) for ~130,000 star-forming galaxies in the Sloan Digital Sky Survey and provide a detailed comparison of these diagnostics in an appendix. Using these abundance ...
Novel relations between the ergodic capacity and the average bit error rate
Yilmaz, Ferkan
2011-11-01
Ergodic capacity and average bit error rate have been widely used to compare the performance of different wireless communication systems. As such recent scientific research and studies revealed strong impact of designing and implementing wireless technologies based on these two performance indicators. However and to the best of our knowledge, the direct links between these two performance indicators have not been explicitly proposed in the literature so far. In this paper, we propose novel relations between the ergodic capacity and the average bit error rate of an overall communication system using binary modulation schemes for signaling with a limited bandwidth and operating over generalized fading channels. More specifically, we show that these two performance measures can be represented in terms of each other, without the need to know the exact end-to-end statistical characterization of the communication channel. We validate the correctness and accuracy of our newly proposed relations and illustrated their usefulness by considering some classical examples. © 2011 IEEE.
A Novel Method for Extracting Respiration Rate and Relative Tidal Volume from Infrared Thermography
Lewis, Gregory F.; Gatto, Rodolfo G.; Porges, Stephen W.
2010-01-01
In psychophysiological research, measurement of respiration has been dependent on transducers having direct contact with the participant. The current study provides empirical data demonstrating that a noncontact technology, infrared video thermography, can accurately estimate breathing rate and relative tidal volume across a range of breathing patterns. Video tracking algorithms were applied to frame-by-frame thermal images of the face to extract time series of nostril temperature and to generate breath-by-breath measures of respiration rate and relative tidal volume. The thermal indices of respiration were contrasted with criterion measures collected with inductance plethysmography. The strong correlations observed between the technologies demonstrate the potential use of facial video thermography as a noncontact technology to monitor respiration. PMID:21214587
Novel Relations between the Ergodic Capacity and the Average Bit Error Rate
Yilmaz, Ferkan
2012-01-01
Ergodic capacity and average bit error rate have been widely used to compare the performance of different wireless communication systems. As such recent scientific research and studies revealed strong impact of designing and implementing wireless technologies based on these two performance indicators. However and to the best of our knowledge, the direct links between these two performance indicators have not been explicitly proposed in the literature so far. In this paper, we propose novel relations between the ergodic capacity and the average bit error rate of an overall communication system using binary modulation schemes for signaling with a limited bandwidth and operating over generalized fading channels. More specifically, we show that these two performance measures can be represented in terms of each other, without the need to know the exact end-to-end statistical characterization of the communication channel. We validate the correctness and accuracy of our newly proposed relations and illustrated their...
A gain-coefficient switched Alexandrite laser
Lee, Chris J; Boller, Klaus-J
2012-01-01
We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.
Helioseismic Solar Cycle Changes and Splitting Coefficients
S. C. Tripathy; Kiran Jain; A. Bhatnagar
2000-09-01
Using the GONG data for a period over four years, we have studied the variation of frequencies and splitting coefficients with solar cycle. Frequencies and even-order coefficients are found to change significantly with rising phase of the solar cycle. We also find temporal variations in the rotation rate near the solar surface.
Gholamreza Fallah Mohamadi
2009-01-01
Full Text Available (Received 8 April, 2009 ; Accepted 27 May, 2009AbstractBackground and purpose: Radiographic film repeat rate assessment is performed to appropriate profiting of existence resources in therapeutic wards. Multiple exposures of x-ray generators due to repeated radiographic examination can lead to amortization of the radiographic facilities and decrease their longevity and also increases the cost of facilities repair. On the other hand, its therapeutic services are necessary to be carried out for patients as soon as possible. Recognition of radiographic film repeat rate and its related causes will help to eliminate the problems and are cost effective.Materials and methods: In this descriptive study, samples were garnered with data collection and non random model during three months in eight radiographic rooms and four darkrooms belonging to four governmental hospitals, namely Imam Khomeini, Booali Sina, Fatemh Zahra and Zare in Sari. All rejected radiographic films were seen by resident experts in each center and information was entered into designed forms. Radiographic repeat rates were calculated through data available from all recipients and the number of used films. In this article, related causes responsible for repeated radiographic examination including errors in selection of exposure factors (over exposure and under exposure, positioning, centering, film size, equipment, processing or darkroom, movement and others were assessed.Results: In four hospitals, 36,758 films were received during investigation and the number of repeated films was 2,155 (5.9 % were estimated as radiographic repeat rate. The maximum repeat rate belonged to Booali sina Hospital (7.2 % and the minimum one was Zare Hospital (0.7 %. The most important causes were due to over exposure selection (1.4 % and the least one was due to improper selection of film size (0.08 %. The percentage of other factors include, under exposure selection (1.12%, centering (0.92%, others (0
Medication-related problem type and appearance rate in ambulatory hemodialysis patients
Drayer Debra K; Manley Harold J; Muther Richard S
2003-01-01
Abstract Background Hemodialysis (HD) patients are at risk for medication-related problems (MRP). The MRP number, type, and appearance rate over time in ambulatory HD patients has not been investigated. Methods Randomly selected HD patients were enrolled to receive monthly pharmaceutical care visits. At each visit, MRP were identified through review of the patient chart, electronic medical record, patient interview, and communications with other healthcare disciplines. All MRP were categorize...
María Caridad Fragoso Marchante
2010-08-01
Full Text Available Background: Community acquired pneumonia is a common disease that is associated with significant morbidity and mortality rates. In the General University Hospital ´´Dr. Gustavo Aldereguía Lima¨ in Cienfuegos, there are guidelines for the management of patients with community-acquired pneumonia, but no studies have been conducted as to the relation between their compliance and the mortality rate. Objective: To assess the adherence to guidelines for diagnosis and treatment of community-acquired pneumonia and its relation to mortality in hospitalized patients. Methods: A descriptive, observational and prospective case series study was conducted in all patients with a diagnosis of pneumonia or bronchopneumonia at the moment of admission and discharge from June 2006 to May 31, 2007. The relation between the different variables and the mortality rate was analyzed as to the different types of risks and the overall compliance with the guidelines for each risk with mortality. A multivariate analysis (logistic regression was performed, with a 95% confidence interval. Results: The results are presented in tables of numbers and percent. Variables independently associated with mortality were: age (over 65 years old people, radiological lesions in more than one lobe or bilateral, atypical pneumonia debut, negative assessments as to the adherence to guidelines and inadequate treatments. Conclusion: The variables included in the study were enough to explain the final outcome of the patients, so it could be determined, for the first time in Cienfuegos, that the non-compliance with the guidelines of good clinical practice is related to mortality rates.
Bahu, Ramez; Chaftari, Anne-Marie; Hachem, Ray Y; Ahrar, Kamran; Shomali, William; El Zakhem, Aline; Jiang, Ying; AlShuaibi, Munirah; Raad, Issam I
2013-01-01
Nephrostomy tube placement is often necessary to avert acute renal failure in patients with cancer with obstructive uropathy or in patients with ureteral leak. However, there have been limited published studies on the rate and risk of nephrostomy tube related pyelonephritis in patients with cancer. Therefore, in this study we determined rates of nephrostomy tube related pyelonephritis and predisposing risk factors in patients with cancer. We retrospectively reviewed patients who underwent nephrostomy tube placement between September 1, 2009 and September 16, 2010 at MD Anderson Cancer Center. Patients were followed for 90 days. The primary outcome assessed was the development of nephrostomy tube related pyelonephritis and the secondary outcome was the development of asymptomatic bacteriuria. We also determined risk factors associated with pyelonephritis. Of the 200 patients analyzed 38 (19%) had pyelonephritis and 15 (7.5%) had asymptomatic bacteriuria. Of the nephrostomy tube related infections 34 cases (89%) were with the primary nephrostomy tube. Subsequently 4 of the patients who underwent nephrostomy tube exchange had an episode of pyelonephritis. Pyelonephritis developed within the first month in 19 (10%) patients. Prior urinary tract infection and neutropenia were found to be significant risk factors for pyelonephritis (p = 0.047 and 0.03, respectively). The placement of nephrostomy tubes in patients with cancer is associated with a significant rate of pyelonephritis. Neutropenia and history of urinary tract infection were significant risk factors for pyelonephritis. This finding warrants further investigation into preventive strategies to reduce the infection rate. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Yebing Fang
2017-03-01
Full Text Available Understanding the spatial heterogeneity and driving force identification of energy-related CO2 emissions (ECEs can help build consensus for mitigating CO2 emissions and designing appropriate policies. However, previous studies on ECEs that focus on both the global-regional scale and the interaction of factors have been seldom conducted. In this paper, ECE data from 143 countries from 1990 to 2014 were selected to analyze regional differences in ECE growth rates by using the coefficient of variation. Then a geographical detector was used to analyze the key determinant factors on ECE growth rates around the world and in eight types of regions. The results show that: (1 the ECE growth rate in the Organization for Economic Cooperation and Development (OECD region is low and tended to decrease, while in the non-OECD region it is high and tended to increase; (2 the coefficient of variation and detection factor of ECE growth rates at a regional scale are higher than those at a global scale; (3 in terms of the key determinant factors, population growth rate, growth rate of per capita GDP, and energy intensity growth rate are the three key determinant factors of ECE growth rates in the OECD region and most of the non-OECD regions such as non-OECD European and Eurasian (NO-EE, Asia (NO-AS, non-OECD Americas (NO-AM. The key determinant factors in the African (NO-AF region are population growth rates and natural gas carbon intensity growth rates. The key determinant factors of the Middle East (NO-ME are population growth rate, coal carbon intensity growth rate and per capita GDP growth rate; (4 the determinant power of the detection factor, the population growth rate at the global scale and regional scale is the strongest, showing a significant spatial consistency. The determinant power of per capita GDP growth rate and energy intensity growth rate in the OECD region, respectively, rank second and third, also showing a spatial consistency. However, the
Development of Copper Corrosion Products and Relation between Surface Appearance and Corrosion Rate
Lan, Tran Thi Ngoc; Binh, Nguyen Thi Thanh [Vietnam National University, Ho Chi Minh (Viet Nam); Tru, Nguyen Nhi [Vietnam Institute for Tropical Technology and Environmental Protection, Ho Chi Minh (Viet Nam); Yoshino, Tsujino [Osaka Prefecture, Osaka (Japan); Yasuki, Maeda [Osaka Prefecture University, Osaka (Japan)
2008-04-15
Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.
An examination of black/white differences in the rate of age-related mortality increase
Andrew Fenelon
2013-09-01
Full Text Available BACKGROUND The rate of mortality increase with age among adults is typically used as a measure of the rate of functional decline associated with aging or senescence. While black and white populations differ in the level of mortality, mortality also rises less rapidly with age for blacks than for whites, leading to the well-known black/white mortality "crossover". OBJECTIVE This paper investigates black/white differences in the rate of mortality increase with age for major causes of death in order to examine the factors responsible for the black/white crossover. METHODS The analysis considers two explanations for the crossover: selective survival and age misreporting. Mortality is modeled using a Gompertz model for 11 causes of death from ages 50-84 among blacks and whites by sex. RESULTS Mortality increases more rapidly with age for whites than for blacks for nearly all causes of death considered. The all-cause mortality rate of mortality increase is nearly two percentage points higher for whites. The analysis finds evidence for both selective survival and age misreporting, although age misreporting is a more prominent explanation among women. CONCLUSIONS The black/white mortality crossover reflects large differences in the rate of age-related mortality increase. Instead of reflecting the impact of specific causes of death, this pattern exists across many disparate disease conditions, indicating the need for a broad explanation.
Takahashi, Yusuke; Roberts, Brent W; Hoshino, Takahiro
2012-01-01
The pathways between parenting behaviours, personality and physical health have all been separately studied. Prior research has paid little attention to the indirect effects of personality in the path between parenting behaviours and better health. The purpose of this study was to explore the mediational effects of conscientiousness on the relationships between parental socialisation of responsibility and self-rated health, and to examine potential age differences in this mediational pathway. In total, 736 female and 749 male members across Japan participated in this study. They were divided into three groups by age category: younger-, middle-aged and older-aged. Conscientiousness and health were concurrently rated, while parental socialisation of responsibility was retrospectively assessed. Our analyses revealed that parental socialisation of responsibility is positively associated with conscientiousness and self-rated health, that conscientiousness is positively associated with self-rated health, and that conscientiousness fully mediated the effect of parental socialisation of responsibility on self-rated health. The mediational links were consistent across younger, middle-aged and older-aged cohorts. Our findings suggest that greater parental socialisation of responsibility relates to higher conscientiousness, and consequently healthier adults. These findings imply that parental behaviours could be a plausible target for intervention to foster the development of conscientiousness and better health.
The Rate of Water Loss in Relation to Internodes Position and Wood Maturity in Vine Chords
Florin SALA
2017-05-01
Full Text Available The purpose of study was to assess the rate of water loss from the strings of vines in relation to internodes position on vine chords and degree of wood maturity. The biological material was represented by Burgund vine cultivar, to which were analyzed individually all internodes distributed on the chord length (internodes number IN2-19. The rate of water loss and associated parameters (maximum rate of water loss - RWLMax, total drying time - T, time to achieve RWLMax - tRWLMax were determined from the Burgund vine cultivar, in controlled condition. Parameters studied were associated with dry matter content (refractometric method, degree of maturity of the wood, and internodes positions on chord. RWL Max had higher values in the basal internodes (IN2; RWL Max = 0.252±0.005 g/min and lower in the apical internodes (IN17-19; RWLMax = 0.202±0.011 g/min. RWLMax distributions values, according to the position of internodes on chord was described by a third degree polynomial function, statistical safety (R2 = 0.949, p<0.01. Dry substance content in internodes (sugar was correlated with the total time of water loss (T; R2 = 0.945, the time to reach the maximum rate of water loss (tRWLMax; R2 = 0.855, and maximum rate of water loss (RWLMax; R2 = 0.984.
Phonation-related rate coding and recruitment in the genioglossus muscle.
Shumway, K R; Porfirio, D J; Bailey, E F
2015-07-01
Motor unit recruitment was assessed in two muscles with similar muscle fiber-type compositions and that participate in skilled movements: the tongue muscle, genioglossus (GG), and the hand muscle, first dorsal interosseous (FDI). Our primary objectives were to determine in the framework of a voluntary movement whether muscle force is regulated in tongue as it is in limb, i.e., via processes of rate coding and recruitment. Recruitment in the two muscles was assessed within each subject in the context of ramp force (FDI) and in the tongue (GG) during vowel production and specifically, in the context of ramp increases in loudness, and subsequently expressed relative to the maximal. The principle findings of the study are that the general rules of recruitment and rate coding hold true for both GG and FDI, and second, that average firing rates, firing rates at recruitment and peak firing rates in GG are significantly higher than for FDI (P role as (prime) mover and hydrostatic support element.
Glycolysis Is Dynamic and Relates Closely to Respiration Rate in Stored Sugarbeet Roots
Clarice A. Megguer
2017-05-01
Full Text Available Although respiration is the principal cause of the loss of sucrose in postharvest sugarbeet (Beta vulgaris L., the internal mechanisms that control root respiration rate are unknown. Available evidence, however, indicates that respiration rate is likely to be controlled by the availability of respiratory substrates, and glycolysis has a central role in generating these substrates. To determine glycolytic changes that occur in sugarbeet roots after harvest and to elucidate relationships between glycolysis and respiration, sugarbeet roots were stored for up to 60 days, during which activities of glycolytic enzymes and concentrations of glycolytic substrates, intermediates, cofactors, and products were determined. Respiration rate was also determined, and relationships between respiration rate and glycolytic enzymes and metabolites were evaluated. Glycolysis was highly variable during storage, with 10 of 14 glycolytic activities and 14 of 17 glycolytic metabolites significantly altered during storage. Changes in glycolytic enzyme activities and metabolites occurred throughout the 60 day storage period, but were greatest in the first 4 days after harvest. Positive relationships between changes in glycolytic enzyme activities and root respiration rate were abundant, with 10 of 14 enzyme activities elevated when root respiration was elevated and 9 glycolytic activities static during periods of unchanging respiration rate. Major roles for pyruvate kinase and phosphofructokinase in the regulation of postharvest sugarbeet root glycolysis were indicated based on changes in enzymatic activities and concentrations of their substrates and products. Additionally, a strong positive relationship between respiration rate and pyruvate kinase activity was found indicating that downstream TCA cycle enzymes were unlikely to regulate or restrict root respiration in a major way. Overall, these results establish that glycolysis is not static during sugarbeet root
The Association between Work-Related Rumination and Heart Rate Variability: A Field Study
Cropley, Mark; Plans, David; Morelli, Davide; Sütterlin, Stefan; Inceoglu, Ilke; Thomas, Geoff; Chu, Chris
2017-01-01
The objective of this study was to examine the association between perseverative cognition in the form of work-related rumination, and heart rate variability (HRV). We tested the hypothesis that high ruminators would show lower vagally mediated HRV relative to low ruminators during their leisure time. Individuals were classified as being low (n = 17) or high ruminators (n = 19), using the affective scale on the work-related rumination measure. HRV was assessed using a wrist sensor band (Microsoft Band 2). HRV was sampled between 8 pm and 10 pm over three workday evenings (Monday to Wednesday) while individuals carried out their normal evening routines. Compared to the low ruminators, high affective ruminators demonstrated lower HRV in the form of root mean square successive differences (RMSSDs), relative to the low ruminators, indicating lower parasympathetic activity. There was no significant difference in heart rate, or activity levels between the two groups during the recording periods. The current findings of this study may have implications for the design and delivery of interventions to help individuals unwind post work and to manage stress more effectively. Limitations and implications for future research are discussed. PMID:28197087
Dexter, Troy A; Kowalewski, Michał
2013-12-01
Quantitative estimates of growth rates can augment ecological and paleontological applications of body-size data. However, in contrast to body-size estimates, assessing growth rates is often time-consuming, expensive, or unattainable. Here we use an indirect approach, a jackknife-corrected parametric bootstrap, for efficient approximation of growth rates using nearest living relatives with known age-size relationships. The estimate is developed by (1) collecting a sample of published growth rates of closely related species, (2) calculating the average growth curve using those published age-size relationships, (3) resampling iteratively these empirically known growth curves to estimate the standard errors and confidence bands around the average growth curve, and (4) applying the resulting estimate of uncertainty to bracket age-size relationships of the species of interest. This approach was applied to three monophyletic families (Donacidae, Mactridae, and Semelidae) of mollusk bivalves, a group characterized by indeterministic shell growth, but widely used in ecological, paleontological, and geochemical research. The resulting indirect estimates were tested against two previously published geochemical studies and, in both cases, yielded highly congruent age estimates. In addition, a case study in applied fisheries was used to illustrate the potential of the proposed approach for augmenting aquaculture management practices. The resulting estimates of growth rates place body size data in a constrained temporal context and confidence intervals associated with resampling estimates allow for assessing the statistical uncertainty around derived temporal ranges. The indirect approach should allow for improved evaluation of diverse research questions, from sustainability of industrial shellfish harvesting to climatic interpretations of stable isotope proxies extracted from fossil skeletons.
Factors influencing the detection rate of drug-related problems in community pharmacy
Westerlund, T; Almarsdóttir, A B; Melander, A
1999-01-01
This study analyzes relationships between the number of drug-related problems detected in community pharmacy practice and the educational level and other characteristics of pharmacy personnel and their work sites. Random samples of pharmacists, prescriptionists and pharmacy technicians were drawn....... Previous participation in a study or activity on drug-related problems and the size of the pharmacy also had statistically significant effects on the problem detection rate. The use of open-ended questions to create a dialogue with the patient seemed to be a successful means to discover problems....... The results of this study indicate the importance of education and training of pharmacy personnel in detection of drug-related problems. This findings speaks in favor of increasing the pharmacist to other personnel ratio, provided the higher costs will be offset by societal benefits....
Varsha Khare; R S Tiwari; O N Srivastava
2001-06-01
We have investigated Fe substituted versions of the quasicrystalline (qc) alloy corresponding to Al65Cu20(Cr, Fe)15 with special reference to the possible occurrence of various quasicrystalline and related phases. Based on the explorations of various compositions it has been found that alloy compositions Al65Cu20Cr12Fe3 and Al65Cu20Cr9Fe6 exhibit interesting structural phases and features at different quenching rates. At higher quenching rates (wheel speed ∼ 25 m/sec) all the alloys exhibit icosahedral phase. For Al65Cu20Cr12Fe3 alloy, however, both the icosahedral and even the decagonal phases get formed at higher quenching rates. At higher quenching rate, alloy having Fe 3 at% exhibits two bcc phases, bccI ( = 8.9 Å) and bccII ( = 15.45 Å). The orientation relationships between icosahedral and crystalline phases are: Mirror plane ∥[001]bcc I and [351]bcc II, 5-fold ∥ [113]bcc II and 3-fold ∥ [110]bcc II. At lower quenching rate, the alloy having Fe 6 at% exhibits orthorhombic phase ( = 23.6 Å, = 12.4 Å, = 20.1 Å). Some prominent orientation relationships of the orthorhombic phase with decagonal phase have also been reported. At lower quenching rate (∼ 10 m/sec), the alloy (Al65Cu22Cr9Fe6) shows the presence of diffuse scattering of intensities along quasiperiodic direction of the decagonal phase. For making the occurrence of the sheets of intensities intelligible, a model based on the rotation and shift of icosahedra has been put forward.
Relation of ongoing deformation rates to the subduction zone process in southern Alaska
Sauber, Jeanne; McClusky, Simon; King, Robert
1997-11-01
The rate and orientation of ongoing strain associated with subduction of the Pacific plate and the accretion of the Yakutat terrane to southern Alaska has been estimated at 13 sites from Global Positioning System measurements made in June 1993 and 1995. Along the Gulf of Alaska coast near Cape Yakataga, the average rate of deformation, relative to Fairbanks, was ≈38 mm/yr at N32°W. Further inland, above the region where the dip of the downgoing Pacific plate changes from about 10° to >30°, the deformation rate was ≈12mm/yr at N26°W. In the Sourdough/Paxson area, the deformation rate drops to 2-5 mm/yr and suggests a low short-term deformation rate across the Denali fault. Elastic straining of the overriding plate due to back-slip on a main thrust zone with an average dip of about 10° can account for the overall rate and distribution of short-term compressional strain across south central Alaska. Above the transitional region between unstable and stable sliding we suggest that strain associated with ≈15 mm/yr of right-lateral strike-slip occurs also. If the strain accumulated since the two 1899 earthquakes (both MW=8.1) from the offshore Pamplona fault zone to south of the Border Ranges fault (down-dip width ≈100 km) was seismically released on a single fault it would correspond to a M=8.1 earthquake.
Lara, Fernanda; Santamaría, Jesus Rodriguez; Garbers, Luiz Eduardo Fabricio de Melo
2017-01-01
BACKGROUND The best way to approach surgically removed basal cell carcinoma with positive histopathological margins is a controversial issue. Some authors believe that the more appropriate treatment is an immediate reoperation while others prefer a periodic follow up. The rates of recurrence are variable in literature, between 10% and 67%. OBJECTIVE To define the recurrence rate of basal cell carcinoma with positive margins after surgery. Secondarily, identify morphological aspects that can suggest a more frequent tumoral recurrence. METHODS This was a retrospective and observational study made by analysis of medical records of 487 patients between January 2003 and December 2009 in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). From 402 basal cell carcinomas surgically treated, 41 fulfilled inclusion criteria and were evaluated for five years or more. Recurrence rate of these tumors was analyzed in all patients and clinical characteristics such as sex, age, tumor size, tumor site, ulceration, and histological type were evaluated in order to find if they were related to more common tumoral recurrence. RESULTS The rate of positive margins after surgery was 12.18%. There were five cases of tumoral recurrence in the observation group and three cases in the re-excision group. Tumor size, site, histological type, ulceration and type of positive margin did not differ statistically between groups. It was not possible to consider if these factors were important in recurrence rates. STUDY LIMITATIONS Ideally, a prospective study with a larger sample would be more accurate. CONCLUSION The treatment of choice in basal cell carcinoma with positive margins must be individualized to reduce recurrence rates. PMID:28225958
无
2001-01-01
The Sr isotopic systematics in the weathering profiles of biotite granite and granite porphyry in southern Jiangxi Province were investigated. The results showed that during the chemical weathering of granites, remarked fractionation occurred between Rb and Sr. During the early stages of chemical weathering of granites, the released Sr/Si and Sr/Ca ratios are larger than those of the parent rocks, and the leaching rate of Sr is higher than those of Si, Ca, K, Rb, etc. Dynamic variations in relative weathering rates of the main Sr-contributing minerals led to fluctuation with time in 87Sr/86Sr ratios of inherent and released Sr in the weathering crust of granite. Successive weathering of biotite, plagioclase and K-feldspar made 87Sr/86Sr ratios in the weathering residues show such a fluctuation trend as to decrease first, increase, and then decrease again till they maintain stable. This work further indicates that when Sr isotopes are used to trace biogeochemical processes on both the catchment and global scales, one must seriously take account of the prefer-ential release of Sr from dissolving solid phase and the fluctuation of 87Sr/86Sr ratios caused by the variations of relative weathering rates of Sr-contributing minerals.
The rate of handedness conversion and related factors in left-handed children.
Meng, Ling-fu
2007-03-01
The rate of handedness conversion was 2.7% to 11.8% in prior studies based on the total population including innately right-handed people. However, the conversion rate of innately left-handed people has not been reported. The purpose of this study was to investigate the percentage of handedness conversion in children who are innately left-handed. The data in the present study showed that 59.3% (121/211) of left-handed children had been forced to convert to right-handedness. Current handedness was also reported by 114 of the 121 informants, and the rates of right-, left-, and mixed-handedness were 56.1% (64/114), 26.3% (30/114), and 17.5% (20/114) respectively. More than half had successfully changed from left to right. Some variables, especially the educational level of the parents and the child's grade level, were related to this conversion intention. The children whose parents had less education were more likely to be forced to change handedness. Additionally, the rate of handedness conversion in younger children was lower than in older children. However, even for the children whose parents had higher education, or for the children who were younger, there was a high percentage (45.7% and 41.8% respectively) who had changed their handedness. Therefore, preventing the possible side effects for children who have undergone hand conversion should be emphasised in the future.
Pulmonary Artery Wedge Pressure Relative to Exercise Work Rate in Older Men and Women.
Esfandiari, Sam; Wright, Stephen P; Goodman, Jack M; Sasson, Zion; Mak, Susanna
2017-07-01
An augmented pulmonary artery wedge pressure (PAWP) response may explain exercise intolerance in some humans. However, routine use of exercise hemodynamic testing is limited by a lack of data from normal older men and women. Our objective was to evaluate the exercise PAWP response and the potential for sexual dimorphism in healthy, nondyspneic older adults. Thirty-six healthy volunteers (18 men [54 ± 7 yr] and 18 women [58 ± 6 yr]) were studied at rest (control) and during two stages of semi-upright cycle ergometry, at heart rates of 100 bpm (light exercise) and 120 bpm (moderate exercise). Right heart catheterization was performed to measure pulmonary pressures. The PAWP response to exercise was assessed in context of exercise work rate and body size. At control, PAWP was similar between men and women. Work rates were significantly smaller in women at comparable HR (P relative to the increase in cardiac output did not exceed 2 mm Hg·L·min in any volunteer at moderate exercise. The similar rise in the PAWP response to submaximal exercise occurs despite lower work rate in healthy older women compared with men, even when adjusted for smaller body size. It is important to consider sex in the development of normal reference ranges for exercise hemodynamic testing.
Relations between rate of negative reinforcement and the persistence of task completion.
Romani, Patrick W; Ringdahl, Joel E; Wacker, David P; Lustig, Nicole H; Vinquist, Kelly M; Northup, John; Kane, Alexandra M; Carrion, Deva P
2016-03-01
Research has shown that differential reinforcement of alternative behavior (DRA) can be an effective intervention to address problem behavior maintained by negative reinforcement emitted by young children. However, few studies have evaluated the variables that are related to long-term maintenance (i.e., persistence) of treatment effects. Research on behavioral persistence predicts that the rate of reinforcement provided for a target behavior is correlated with its persistence when challenged. There were 2 purposes of the current investigation. First, we evaluated the effects of the rate of negative reinforcement on the persistence of task completion. Second, we applied the findings regarding rate of reinforcement to a treatment context for 3 participants who engaged in destructive behavior that was reinforced by escape from demands. Results were evaluated within a multielement design and indicated that the rate of negative reinforcement had a moderate influence on the persistence of task completion. These results contribute to the existing literature by extending analyses of persistence to treatment contexts.
Chantal A Coles
Full Text Available Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5-20 hours in culture in vitro (P < 0.05. The proliferation rates of myoblasts during early stages of culture in vitro were also found to be positively related to the liveweight and carcase weight of cattle (P < 0.05. Gene expression of MYF5 was also found to be significantly down-regulated in WagyuX compared with Angus cattle (P < 0.05. These findings suggest that early events during myogenesis are important for determining liveweight and caracase weights in cattle.
Naim, Ali; Feldman, Robert; Sawyer, Robin
2015-01-01
Maternal death rates in Afghanistan were among the highest in the world during the reign of the Taliban. Although these figures have improved, current rates are still alarming. The aim of this pilot study was to develop a needs assessment of the major health issues related to the high maternal mortality rates in Afghanistan. In-depth interviews were conducted with managerial midwives, clinical midwives, and mothers. Results of the interviews indicate that the improvement in the maternal mortality rate may be attributed to the increase in the involvement of midwives in the birthing process. However, barriers to decreasing maternal mortality still exist. These include transportation, access to care, and sociocultural factors such as the influence of the husband and mother-in-law in preventing access to midwives. Therefore, any programs to decrease maternal mortality need to address infrastructure issues (making health care more accessible) and sociocultural factors (including husbands and mother-in-laws in maternal health education). However, it should be noted that these findings are based on a small pilot study to help develop a larger scale need assessment.
Li, Weidong; Leaman, Jesse; Filippenko, Alexei V; Poznanski, Dovi; Wang, Xiaofeng; Ganeshalingam, Mohan; Mannucci, Filippo
2010-01-01
This is the third paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search (LOSS). We have considered a sample of about 1000 SNe and used an optimal subsample of 726 SNe (274 SNe Ia, 116 SNe Ibc, and 324 SNe II) to determine our rates. We study the trend of the rates as a function of a few quantities available for our galaxy sample, such as luminosity in the B and K bands, stellar mass, and morphological class. We discuss different choices (SN samples, input SN luminosity functions, inclination correction factors) and their effect on the rates and their uncertainties. A comparison between our SN rates and the published measurements shows that they are consistent with each other to within uncertainties when the rate calculations are done in the same manner. Nevertheless, our data demonstrate that the rates cannot be adequately described by a single parameter using either galaxy Hubble types or B...
Abecia, J. A.; Arrébola, F.; Macías, A.; Laviña, A.; González-Casquet, O.; Benítez, F.; Palacios, C.
2016-10-01
A total number of 1092 artificial inseminations (AIs) performed from March to May were documented over four consecutive years on 10 Payoya goat farms (36° N) and 19,392 AIs on 102 Rasa Aragonesa sheep farms (41° N) over 10 years. Mean, maximum, and minimum ambient temperatures, mean relative humidity, mean solar radiation, and total rainfall on each insemination day were recorded. Overall, fertility rates were 58 % in goats and 45 % in sheep. The fertility rates of the highest and lowest deciles of each of the meteorological variables indicated that temperature and rainfall had a significant effect on fertility in goats. Specifically, inseminations that were performed when mean (68 %), maximum (68 %), and minimum (66 %) temperatures were in the highest decile, and rainfall was in the lowest decile (59 %), had a significantly ( P AI in spring. It remains to be determined whether scheduling the dates of insemination based on forecasted temperatures can improve the success of AI in goats and sheep.
Heart rate during conflicts predicts post-conflict stress-related behavior in greylag geese.
Claudia A F Wascher
Full Text Available BACKGROUND: Social stressors are known to be among the most potent stressors in group-living animals. This is not only manifested in individual physiology (heart rate, glucocorticoids, but also in how individuals behave directly after a conflict. Certain 'stress-related behaviors' such as autopreening, body shaking, scratching and vigilance have been suggested to indicate an individual's emotional state. Such behaviors may also alleviate stress, but the behavioral context and physiological basis of those behaviors is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We recorded beat-to-beat heart rates (HR of 22 greylag geese in response to agonistic encounters using fully implanted sensor-transmitter packages. Additionally, for 143 major events we analyzed the behavior shown by our focal animals in the first two minutes after an interaction. Our results show that the HR during encounters and characteristics of the interaction predicted the frequency and duration of behaviors shown after a conflict. CONCLUSIONS/SIGNIFICANCE: To our knowledge this is the first study to quantify the physiological and behavioral responses to single agonistic encounters and to link this to post conflict behavior. Our results demonstrate that 'stress-related behaviors' are flexibly modulated by the characteristics of the preceding aggressive interaction and reflect the individual's emotional strain, which is linked to autonomic arousal. We found no support for the stress-alleviating hypothesis, but we propose that stress-related behaviors may play a role in communication with other group members, particularly with pair-partners.
Janssen, O.; van der Vegt, G.S.
2011-01-01
As hypothesized, data from two field studies among employees and their supervisors showed that employees are more likely to positively bias their self-ratings relative to supervisor ratings when creative performance rather than inrole performance is being evaluated. In addition, employees' performan
Dependence of the firearm-related homicide rate on gun availability: a mathematical analysis.
Wodarz, Dominik; Komarova, Natalia L
2013-01-01
In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data.
Dependence of the firearm-related homicide rate on gun availability: a mathematical analysis.
Dominik Wodarz
Full Text Available In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data.
Klinich, Kathleen D; Benedetti, Marco; Manary, Miriam A; Flannagan, Carol A
2017-05-19
State laws regarding child passenger protection vary substantially. The objective of this study was to develop a scoring system to rate child passenger safety laws relative to best practice recommendations for each age of child. State child passenger safety and seat belt laws were retrieved from the LexisNexis database for the years 2002-2015. Text of the laws was reviewed and compared to current best practice recommendations for child occupant protection for each age of child. A 0-4 scale was developed to rate the strength of the state law relative to current best practice recommendations. A rating of 3 corresponds to a law that requires a restraint that is sufficient to meet best practice, and a rating of 4 is given to a law that specifies several options that would meet best practice. Scores of 0, 1, or 2 are given to laws requiring less than best practice to different degrees. The same scale is used for each age of child despite different restraint recommendations for each age. Legislation that receives a score of 3 requires rear-facing child restraints for children under age 2, forward-facing harnessed child restraints for children aged 2 to 4, booster seats for children 5 to 10, and primary enforcement of seat belt use in all positions for children aged 11-13. Legislation requiring use of a "child restraint system according to instructions" would receive a score of 1 for children under age 2 and a 2 for children aged 2-4 because it would allow premature use of a booster for children weighing more than 13.6 kg (30 lb). The scoring system developed in this study can be used in mathematical models to predict how child passenger safety legislation affects child restraint practices.
Short-Term Heart Rate Recovery is Related to Aerobic Fitness in Elite Intermittent Sport Athletes.
Watson, Andrew M; Brickson, Stacey L; Prawda, Evan R; Sanfilippo, Jenifer L
2017-04-01
Watson, AM, Brickson, SL, Prawda, ER, and Sanfilippo, JL. Short-term heart rate recovery is related to aerobic fitness in elite intermittent sport athletes. J Strength Cond Res 31(4): 1055-1061, 2017-Although heart rate recovery (HRR) has been suggested as a measure of fitness, minimal data exist among athletes. The purpose of this study was to determine if HRR is related to aerobic fitness in elite athletes and whether this relationship is influenced by sex or body composition. Eighty-four collegiate athletes (45 male athletes) underwent body fat percentage (BF%) determination by dual-energy x-ray absorptiometry and maximal treadmill testing followed by 5 minutes of recovery. V[Combining Dot Above]O2max and heart rate (HRmax) were determined, and HRR was calculated as a percentage of HRmax at 10 seconds, 30 seconds, and 1, 2, 3, 4, and 5 minutes after test completion. After stratifying by sex, participants were grouped as high fit or low fit based on V[Combining Dot Above]O2max median split. Heart rate recovery was compared between sexes and fitness level at each time point. Multivariable regression analysis was used to identify independent predictors of HRR using V[Combining Dot Above]O2max, BF%, and sex as covariates. Heart rate recovery did not differ significantly between sexes and was faster among high-fit participants at 10 and 30 seconds, but at no other time. V[Combining Dot Above]O2max was significantly correlated with HRR at 10 and 30 seconds (r = -0.34, p < 0.001 and r = -0.28, p = 0.008) only. After controlling for BF% and sex, V[Combining Dot Above]O2max remained significantly associated with HRR at 10 seconds (p = 0.007) but not at 30 seconds (p = 0.067) or any time thereafter. Aerobic capacity is related to faster HRR during the first 30 seconds only, suggesting that only very short term HRR should be used as a measure of aerobic fitness in intermittent sport athletes.
Relation of heart rate recovery after exercise testing to coronary artery calcification.
Jae, Sae Young; Kurl, Sudhir; Laukkanen, Jari A; Yoon, Eun Sun; Choi, Yoon-Ho; Fernhall, Bo; Franklin, Barry A
2017-08-01
We examined whether slow heart rate recovery (HRR) after exercise testing as an estimate of impaired autonomic function is related to coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. We evaluated 2088 men who participated in a health-screening program that included measures of CAC and peak or symptom-limited cardiopulmonary exercise testing. HRR was calculated as the difference between peak heart rate (HR) during exercise testing and the HR at 2 min of recovery after peak exercise. We measured CAC using multidetector computed tomography to calculate the Agatston coronary artery calcium score. Advanced CAC was defined as a mean CAC >75th percentile for each age group. HRR was negatively correlated with CAC (r = -.14, p 52 bpm). Each 1 bpm decrease in HRR was associated with 1% increase in advanced CAC after adjusting for potential confounders. An attenuated HRR after exercise testing is associated with advanced CAC, independent of coronary risk factors and other related hemodynamic response. KEY MESSAGES Slow heart rate recovery (HRR) after maximal exercise testing, indicating decreased autonomic function, is associated with an increased risk of cardiovascular event and mortality. Slow HRR has been linked with the occurrence of malignant ventricular arrhythmias, but it remains unclear whether slow HRR is associated with an increased risk of coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. An attenuated HRR after exercise testing was associated with advanced CAC, independent of coronary risk factors and other potential hemodynamic confounder, supporting the hypothesis that slow HRR is related to the burden of atherosclerotic coronary artery disease.
Luiz Ernesto de Almeida Troncon
Full Text Available CONTEXT AND OBJECTIVE: Overall ratings (ORs of competence, given by expert physicians, are increasingly used in clinical skills assessments. Nevertheless, the influence of specific components of competence on ORs is incompletely understood. The aim here was to investigate whether ORs for medical student history-taking competence are influenced by performance relating to communication skills, completeness of questioning and asking contentdriven key questions. DESIGN AND SETTING: Descriptive, quantitative study at Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo. METHODS: Thirty-six medical students were examined in a 15-station high-stake objective structured clinical examination (OSCE. At four stations devoted to history-taking, examiners filled out checklists covering the components investigated and independently rated students’ overall performance using a five-point scale from 1 (poor to 5 (excellent. Physician ratings were aggregated for each student. Nonparametric correlations were made between ORs. RESULTS: ORs presented significant correlations with checklist scores (Spearman’s rs = 0.38; p = 0.02 and OSCE general results (rs = 0.52; p < 0.001. Scores for "communication skills" tended to correlate with ORs (rs = 0.31, but without reaching significance (p = 0.06. Neither the scores for "completeness" (rs = 0.26; p = 0.11 nor those for "asking key questions" (rs = 0.07; p = 0.60 correlated with ORs. CONCLUSIONS: Experts’ overall ratings for medical student competence regarding history-taking is likely to encompass a particular dimension, since ratings were only weakly influenced by specific components of performance.
Kallio, J; Søgaard, Karen; Avela, J
2012-01-01
Aging is related to multiple changes in muscle physiology and function. Previous findings concerning the effects of aging on motor unit discharge rate (DR) and fluctuations in DR and force are somewhat contradictory. Eight YOUNG and nine OLD physically active males performed isometric ramp (RECR......) and isotonic (ISO) plantar flexions at 10 and 20% of surface EMG at MVC. Motor unit (MU) action potentials were recorded with intramuscular fine-wire electrodes and decomposed with custom build software "Daisy". DR was lower in OLD in RECR-10% (17.9%, p...
Kramer, Gunnar R.; Chalfoun, Anna D.
2012-01-01
Relocation by dependent young is a survival strategy that occurs among a wide range of taxa. The Common Nighthawk (Chordeiles minor) lays its eggs on bare substrate and, once hatched, nestlings may relocate to new sites daily. We located and monitored eight Common Nighthawk nests in Grand Teton National Park, Wyoming, quantified inter-use-site distances in relation to nestling age, and calculated a nestling growth rate curve. Common Nighthawk nestlings grow in a nearly linear fashion. Nestlings moved up to 48 m in a single day and larger, older nestlings tended to move greater distances between daily use-sites.
Lorenzo Iorio
2014-01-01
Full Text Available By phenomenologically assuming a slow temporal variation of the percent acceleration rate S̈S -1 of the cosmic scale factor S(t, it is shown that the orbit of a local binary undergoes a secular expansion. To first order in the power expansion of S̈S -1 around the present epoch t0, a non-vanishing shift per orbit (Δr of the two-body relative distance r occurs for eccentric trajectories. A general relativistic expression, which turns out to be cubic in the Hubble parameter H0 at the present epoch, is explicitly calculated for it in the case of matter-dominated epochs with Dark Energy. For a highly eccentric Oort comet orbit with period Pb ≈ 31 Myr, the general relativistic distance shift per orbit turns out to be of the order of (Δr ≈ 70 km. For the Large Magellanic Cloud, assumed on a bound elliptic orbit around the Milky Way, the shift per orbit is of the order of (Δr ≈ 2–4 pc. Our result has a general validity since it holds in any cosmological model admitting the Hubble law and a slowly varying S̈S-1(t. More generally, it is valid for an arbitrary Hooke-like extra-acceleration whose “elastic” parameter κ is slowly time-dependent, irrespectively of the physical mechanism which may lead to it. The coefficient κ1 of the first-order term of the power expansion of κ(t can be preliminarily constrained in a model-independent way down to a κ1 ≲ 2 x 10-13 year-3 level from latest Solar System’s planetary observations. The radial velocities of the double lined spectroscopic binary ALPHA Cen AB yield κ1 ≲ 10-8 year-3.
Iorio, Lorenzo
2014-01-01
By phenomenologically assuming a slow temporal variation of the percent acceleration rate S̈S -1 of the cosmic scale factor S(t), it is shown that the orbit of a local binary undergoes a secular expansion. To first order in the power expansion of S̈S -1 around the present epoch t0, a non-vanishing shift per orbit (Δr) of the two-body relative distance r occurs for eccentric trajectories. A general relativistic expression, which turns out to be cubic in the Hubble parameter H0 at the present epoch, is explicitly calculated for it in the case of matter-dominated epochs with Dark Energy. For a highly eccentric Oort comet orbit with period Pb ≈ 31 Myr, the general relativistic distance shift per orbit turns out to be of the order of (Δr) ≈ 70 km. For the Large Magellanic Cloud, assumed on a bound elliptic orbit around the Milky Way, the shift per orbit is of the order of (Δr) ≈ 2-4 pc. Our result has a general validity since it holds in any cosmological model admitting the Hubble law and a slowly varying S̈S-1(t). More generally, it is valid for an arbitrary Hooke-like extra-acceleration whose "elastic" parameter κ is slowly time-dependent, irrespectively of the physical mechanism which may lead to it. The coefficient κ1 of the first-order term of the power expansion of κ(t) can be preliminarily constrained in a model-independent way down to a κ1 ≤ 2 x 10-13 year-3 level from latest Solar System's planetary observations. The radial velocities of the double lined spectroscopic binary ALPHA Cen AB yield κ1 ≤ 10-8 year-3.
Calculation of Empirical and True Maintenance Coefficients by Flux Balance Analysis
MaHongwu; ZhaoXueming; 等
2002-01-01
The stoichiometric matrix of a simplified metabolic network in Bacillus Subtillis was contructed from the flux balance equations, which were used for reconciliation of the measured rates and determination of the inner metabolic rates. Thus more reliable results of the true and empirical maintenance coefficients were obtained. The true maintenance coefficient is linearly related to the specific growth rate and changes with the P/O ratiol. The neasured biomass yield of adenosine triphosphate (ATP) is also linearly related to the P/O ratio.
Evolution of mitochondrial DNA and its relation to basal metabolic rate.
Feng, Ping; Zhao, Huabin; Lu, Xin
2015-08-01
Energy metabolism is essential for the survival of animals, which can be characterized by maximum metabolic rate (MMR) and basal metabolic rate (BMR). Because of the crucial roles of mitochondria in energy metabolism, mitochondrial DNA (mtDNA) has been subjected to stronger purifying selection in strongly locomotive than weakly locomotive birds and mammals. Although maximum locomotive speed (an indicator of MMR) showed a negative correlation with the evolutionary rate of mtDNA, it is unclear whether BMR has driven the evolution of mtDNA. Here, we take advantage of the large amount of mtDNA and BMR data in 106 mammals to test whether BMR has influenced the mtDNA evolution. Our results showed that, in addition to the locomotive speed, mammals with higher BMR have subjected to stronger purifying selection on mtDNA than did those with lower BMR. The evolution of mammalian mtDNA has been modified by two levels of energy metabolism, including MMR and BMR. Our study provides a more comprehensive view of mtDNA evolution in relation to energy metabolism.
Period -- mass-loss rate relation of Miras with and without technetium
Uttenthaler, Stefan
2013-01-01
Aims: We report the discovery that Mira variables with and without absorption lines of the element technetium (Tc) occupy two different regions in a diagram of near- to mid-infrared colour versus pulsation period. Tc is an indicator of a recent or ongoing mixing event called the third dredge-up (3DUP), and the near- to mid-IR colour, such as the (K-[22]) colour where [22] is the the 22 micron band of the WISE space observatory, is an indicator of the dust mass-loss rate of a star. Methods: We collected data from the literature about the Tc content, pulsation period, and near- and mid-infrared magnitudes of more than 190 variable stars on the asymptotic giant branch (AGB) to which Miras belong. The sample is naturally biased towards optical AGB stars, which have low to intermediate (dust) mass-loss rates. Results: We show that a clear relation between dust mass-loss rate and pulsation period exists if a distinction is made between Tc-poor and Tc-rich Miras. Surprisingly, at a given period, Tc-poor Miras are re...
The Relative Rate of LGRB Formation as a Function of Metallicity
Graham, J F
2015-01-01
There is now strong evidence that Long-duration Gamma-Ray Bursts (LGRBs) are preferentially formed in low-metallicity environments. However, the magnitude of this effect, and its functional dependence on metallicity have not been well characterized. In our previous paper, Graham & Fruchter (2013), we compared the metallicity distribution of LGRB host galaxies to the that of star forming galaxies in the local universe. Here we build upon this work by in effect dividing one distribution by the other, and thus directly determine the relative rate of LGRB formation as a function of metallicity in the low-redshift universe. We find a dramatic cutoff in LGRB formation above a metallicity of log(O/H)}+12 ~ 8.3 in the KK04 scale, with LGRBs forming >25 times more frequently per unit star-formation below this cutoff than above. Furthermore, our data suggests that the rate of LGRB formation per unit star formation continues to fall above this break. We estimate the LGRB formation rate per unit star formation may dr...
The relation between atomic gas and star formation rate densities in faint irregular galaxies
Roychowdhury, Sambit; Kaisin, Serafim S; Karachentsev, Igor D
2014-01-01
We use data for faint (M_B > -14.5) dwarf irregular galaxies drawn from the FIGGS survey to study the correlation between the atomic gas density (Sigma_gas,atomic) and star formation rate (Sigma_SFR) in the galaxies. The estimated gas phase metallicity of our sample galaxies is Z ~ 0.1 Z_sun. Understanding star formation in such molecule poor gas is of particular importance since it is likely to be of direct relevance to simulations of early galaxy formation. For about 20% (9/43) of our sample galaxies, we find that the HI distribution is significantly disturbed, with little correspondence between the optical and HI distributions. We exclude these galaxies from the comparison. We also exclude galaxies with very low star formation rates, for which stochastic effects make it difficult to estimate the true star formation rates. For the remaining galaxies we compute the Sigma_gas,atomic and Sigma_SFR averaged over the entire star forming disk of the galaxy. For these galaxies we find a nearly linear relation betw...
Mechanical properties and constitutive relations for molybdenum under high-rate deformation
Chen, S.R.; Maudlin, P.J.; Gray, G.T. III
1998-01-01
Molybdenum and its alloys have received increased interest in recent years for ballistic applications. The stress-strain behavior of several molybdenums possessing various compositions, manufacturing sources, and the degree of pre-straining, were investigated as a function of temperature from 77 to 1,273 K, and strain rate from 10{sup {minus}3} s{sup {minus}1} to 8,000 s{sup {minus}1}. The yield stress was found to be sensitive to the test temperature and strain rate, however, the strain hardening remained rate-insensitive. The constitutive response of a powder-metallurgy molybdenum was also investigated; similar mechanical properties compared to conventionally wrought processed molybdenums were achieved. Constitutive relations based upon the Johnson-Cook, the Zerilli-Armstrong and the Mechanical Threshold Stress (MTS) models were evaluated and fit for the various Mo-based materials. The capabilities and limitations of each model for large-strain applications were examined. The differences between the three models are demonstrated using model comparisons to Taylor cylinder validation experiments.
A retrospective study on related factors affecting the survival rate of dental implants
Kang, Jeong-Kyung; Lee, Ki; Lee, Yong-Sang; Park, Pil-Kyoo
2011-01-01
PURPOSE The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age 65 ± 10.58 years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P.05). CONCLUSION Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival. PMID:22259704
Estimation of growth rate of Skeletonema costatum based on relative expression amount of PCNA gene
HE Shanying; YU Zhigang
2008-01-01
Partial sequence of Skeletonema costatum proliferating cell nuclear antigen (PCNA) gene was obtained by reverse transcriptase PCR(RT-PCR) and 3' rapid amplification of cDNA ends (3'-RACE) techniques.Based on the obtained PCNA and cytochrome b gene(Cyt b gene) sequences,a real-time fluorescent quantitative PCR (FQ-PCR) method was developed to detect the expres-sion S.costatum PCNA gene,and this method was applied to study the relationship between the growth rate of S.costatum and the average expression amount of PCNA gene in a single cell.The expression amount of PCNA gene had large variation in cells col-lected at different culture phases,and the trend was well consistent with the growth rate,which suggested that the expression amount of PCNA gene correlated well with the cell division,and the PCNA could be a promising indicator for the S.costatum cell proliferation.Furthermore,using the PCNA gene as the objective gene and the Cyt b gene as the house-keeping gene,a new method for estimating the in situ growth rate of S.costatum was established by analysis of the relative expression quantity (REQ) of the PCNA gene.
Low heart rate variability and cancer-related fatigue in breast cancer survivors.
Crosswell, Alexandra D; Lockwood, Kimberly G; Ganz, Patricia A; Bower, Julienne E
2014-07-01
Cancer-related fatigue is a common and often long lasting symptom for many breast cancer survivors. Fatigued survivors show evidence of elevated inflammation, but the physiological mechanisms driving inflammatory activity have not been determined. Alterations in the autonomic nervous system, and particularly parasympathetic nervous system activity, are a plausible, yet understudied contributor to cancer-related fatigue. The goal of this study was to replicate one previous study showing an association between lower parasympathetic activity and higher fatigue in breast cancer survivors (Fagundes et al., 2011), and to examine whether inflammation mediates this association. Study participants were drawn from two samples and included 84 women originally diagnosed with early stage breast cancer prior to age 50. Participants completed questionnaires, provided blood samples for determination of interleukin (IL)-6 and C-reactive protein (CRP), and underwent electrocardiography (ECG) assessment for evaluation of resting heart rate variability (HRV), a measure of parasympathetic activity. Results showed that lower HRV was associated with higher fatigue (pcancer-related fatigue, but suggest that inflammation does not mediate this association in younger, healthy breast cancer survivors who are several years post-treatment. The autonomic nervous system merits additional attention in research on the etiology of cancer-related fatigue.
Development in self-rated health among older people as determinant of social relations
Lund, Rikke; Avlund, Kirsten; Modvig, Jens
2004-01-01
AIM: The purpose of this study was to analyse whether development in self-rated health (SRH) over four years was associated with the structure of and satisfaction with social relations, at four and eight years follow-up, among elderly women and men. METHODS: A longitudinal questionnaire-based study...... was undertaken of non-institutionalized Danes, aged 70-95 years, with baseline in 1986. The response rate at baseline was 69%, n= 1,231. First follow-up was carried out in 1990, with 91% of eligible individuals participating (n=911). Second follow-up took place in 1994, where 83% of eligible individuals...... participated (n= 542). The association was studied between development in SRH from 1986 to 1990 and social relations in 1990 and in 1994. RESULTS: A sustained poor SRH predicted low contact frequency OR= 1.7 (1.1-2.6), small contact diversity OR= 1.6 (1.0-2.6) and low contact satisfaction OR=3.4 (2...
Gonçalves, Hernâni; Fernandes, Diana; Pinto, Paula; Ayres-de-Campos, Diogo; Bernardes, João
2017-08-21
Male gender is considered a risk factor for several adverse perinatal outcomes. Fetal gender effect on fetal heart rate (FHR) has been subject of several studies with contradictory results. The importance of maternal heart rate (MHR) monitoring during labor has also been investigated, but less is known about the effect of fetal gender on MHR. The aim of this study is to simultaneously assess maternal and FHR variability during labor in relation with fetal gender. Simultaneous MHR and FHR recordings were obtained from 44 singleton term pregnancies during the last 2 hr of labor (H1, H2 ). Heart rate tracings were analyzed using linear (time- and frequency-domain) and nonlinear indices. Both linear and nonlinear components were considered in assessing FHR and MHR interaction, including cross-sample entropy (cross-SampEn). Mothers carrying male fetuses (n = 22) had significantly higher values for linear indices related with MHR average and variability and sympatho-vagal balance, while the opposite occurred in the high-frequency component and most nonlinear indices. Significant differences in FHR were only observed in H1 with higher entropy values in female fetuses. Assessing the differences between FHR and MHR, statistically significant differences were obtained in most nonlinear indices between genders. A significantly higher cross-SampEn was observed in mothers carrying female fetuses (n = 22), denoting lower synchrony or similarity between MHR and FHR. The variability of MHR and the synchrony/similarity between MHR and FHR vary with respect to fetal gender during labor. These findings suggest that fetal gender needs to be taken into account when simultaneously monitoring MHR and FHR. © 2017 Wiley Periodicals, Inc.
Multidimensional extremal dependence coefficients
2017-01-01
Extreme values modeling has attracting the attention of researchers in diverse areas such as the environment, engineering, or finance. Multivariate extreme value distributions are particularly suitable to model the tails of multidimensional phenomena. The analysis of the dependence among multivariate maxima is useful to evaluate risk. Here we present new multivariate extreme value models, as well as, coefficients to assess multivariate extremal dependence.
Medication-related problem type and appearance rate in ambulatory hemodialysis patients
Manley, Harold J; Drayer, Debra K; Muther, Richard S
2003-01-01
Background Hemodialysis (HD) patients are at risk for medication-related problems (MRP). The MRP number, type, and appearance rate over time in ambulatory HD patients has not been investigated. Methods Randomly selected HD patients were enrolled to receive monthly pharmaceutical care visits. At each visit, MRP were identified through review of the patient chart, electronic medical record, patient interview, and communications with other healthcare disciplines. All MRP were categorized by type and medication class. MRP appearance rate was determined as the number of MRP identified per month/number of months in study. The number of MRP per patient-drug exposures were determined using: {[(number of patients) × (mean number of medications)]/(number of months of study)} /number of MRP identified. Results were expressed as mean ± standard deviation or percentages. Results Patients were 62.6 ± 15.9 years old, had 6.4 ± 2.0 comorbid conditions, were taking 12.5 ± 4.2 medications, and 15.7 ± 7.2 doses per day at baseline. Medication-dosing problems (33.5%), adverse drug reactions (20.7%), and an indication that was not currently being treated (13.5%) were the most common MRP. 5,373 medication orders were reviewed and a MRP was identified every 15.2 medication exposures. Overall MRP appearance rate was 0.68 ± 0.46 per patient per month. Conclusion MRP continue to occur at a high rate in ambulatory HD patients. Healthcare providers taking care of HD patients should be aware of this problem and efforts to avoid or resolve MRP should be undertaken at all HD clinics. PMID:14690549
Medication-related problem type and appearance rate in ambulatory hemodialysis patients
Drayer Debra K
2003-12-01
Full Text Available Abstract Background Hemodialysis (HD patients are at risk for medication-related problems (MRP. The MRP number, type, and appearance rate over time in ambulatory HD patients has not been investigated. Methods Randomly selected HD patients were enrolled to receive monthly pharmaceutical care visits. At each visit, MRP were identified through review of the patient chart, electronic medical record, patient interview, and communications with other healthcare disciplines. All MRP were categorized by type and medication class. MRP appearance rate was determined as the number of MRP identified per month/number of months in study. The number of MRP per patient-drug exposures were determined using: {[(number of patients × (mean number of medications]/(number of months of study} /number of MRP identified. Results were expressed as mean ± standard deviation or percentages. Results Patients were 62.6 ± 15.9 years old, had 6.4 ± 2.0 comorbid conditions, were taking 12.5 ± 4.2 medications, and 15.7 ± 7.2 doses per day at baseline. Medication-dosing problems (33.5%, adverse drug reactions (20.7%, and an indication that was not currently being treated (13.5% were the most common MRP. 5,373 medication orders were reviewed and a MRP was identified every 15.2 medication exposures. Overall MRP appearance rate was 0.68 ± 0.46 per patient per month. Conclusion MRP continue to occur at a high rate in ambulatory HD patients. Healthcare providers taking care of HD patients should be aware of this problem and efforts to avoid or resolve MRP should be undertaken at all HD clinics.
Exploring non-linear cosmological matter diffusion coefficients
Velten, Hermano
2014-01-01
Since microscopic velocity diffusion can be incorporated into general relativity in a consistent way, we study cosmological background solutions when the diffusion phenomena takes place in an expanding universe. Our focus here relies on the nature of the diffusion coefficient $\\sigma$ which measures the magnitude of such transport phenomena. We test dynamics where $\\sigma$ has a phenomenological dependence on the scale factor, the matter density, the dark energy and the expansion rate.
Turnover rate of cerebrospinal fluid in female sheep: changes related to different light-dark cycles
Malpaux Benoit
2009-08-01
Full Text Available Abstract Background Sheep are seasonal breeders. The key factor governing seasonal changes in the reproductive activity of the ewe is increased negative feedback of estradiol at the level of the hypothalamus under long-day conditions. It has previously been demonstrated that when gonadotropin secretions are inhibited during long days, there is a higher concentration of estradiol in the cerebrospinal fluid (CSF than during short days. This suggests an involvement of the CSF and choroid plexus in the neuroendocrine regulatory loop, but the mechanisms underlying this phenomenon remain unknown. One possible explanation of this difference in hormonal content is an effect of concentration or dilution caused by variations in CSF secretion rate. The aim of this study was thus to investigate changes in the CSF turnover rate related to light-dark cycles. Methods The turnover rate of the CSF was estimated by measuring the time taken for the recovery of intraventricular pressure (IVP after removal of a moderate volume (0.5 to 2 ml of CSF (slope in mmHg/min. The turnover rate was estimated three times in the same group of sheep: during a natural period of decreasing day-length corresponding to the initial period when gonadotropin activity is stimulated (SG1, during a long-day inhibitory period (IG, and finally during a short-day stimulatory period (SG2. Results The time taken and the speed of recovery of initial IVP differed between groups: 8 min 30 sec, 0.63 ± 0.07 mmHg/min(SG1, 11 min 1 sec, 0.38 ± 0.06 mmHg/min (IG and 9 min 0 sec, 0.72 ± 0.15 mmHg/min (SG2. Time changes of IVP differed between groups (ANOVA, p p p = 0.41, but was significantly different from IG: 71.33 ± 16.59 μl/min (p = 0.016. Conclusion This study shows that the turnover rate of CSF in ewes changes according to the light-dark cycle; it is increased during short day periods and reduced in long day periods. This phenomenon could account for differences in hormonal concentrations in
Prestarlike functions with negative coefficients
H. Silverman
1979-01-01
Full Text Available The extreme points for prestarlike functions having negative coefficients are determined. Coefficient, distortion and radii of univalence, starlikeness, and convexity theorems are also obtained.
Wu, Nan; Liu, Hao; Chen, Jun; Zhao, Luo; Zuo, Wei; Ming, Yue; Liu, Sen; Liu, Jiaqi; Su, Xinlin; Gao, Baoxiang; Tang, Zhiquan; Qiu, Guixing; Ma, Guolin; Wu, Zhihong
2013-01-01
To compare the variation patterns of ADC and T2 values in different age and intervertebral disc (IVD) levels, thus to identify their sensitivities in assessing age and disc level related IVDs changes. The T2 and ADC values were recorded from 345 IVDs of 69 volunteers. Kendall's correlation analysis was used to identify the relationship between age and T2/ADC mean values respectively. The one-way analysis of variance (ANOVA) with post hoc analysis was then applied to test the differences of T2 and ADC values among different IVD levels and age groups, followed by linear regression analysis between age (45 years) and T2/ADC mean values. This study was approved by the Ethics Committee of the Chinese Academy of Medical Sciences and the Peking Union Medical College Hospital. Significant negative correlation was observed between age and T2/ADC mean values. The T2 and ADC values showed significant differences among IVD levels and among age groups except for T2 values in age group 1 (25-34 years) and group 2 (35-44 years), and for ADC values at L1-2 level. Both T2 and ADC values showed significant differences between young (age45 years) at each IVD level. A linear relationship was observed between age and T2/ADC mean values in the elderly group as well as in the young group for the ADC mean values, while no such tendency was identified in the young group for the T2 mean values. ADC values may be a more sensitive parameter than T2 in assessing age and disc level related intervertebral disc changes.
Nan Wu
Full Text Available PURPOSE: To compare the variation patterns of ADC and T2 values in different age and intervertebral disc (IVD levels, thus to identify their sensitivities in assessing age and disc level related IVDs changes. MATERIALS AND METHODS: The T2 and ADC values were recorded from 345 IVDs of 69 volunteers. Kendall's correlation analysis was used to identify the relationship between age and T2/ADC mean values respectively. The one-way analysis of variance (ANOVA with post hoc analysis was then applied to test the differences of T2 and ADC values among different IVD levels and age groups, followed by linear regression analysis between age (45 years and T2/ADC mean values. This study was approved by the Ethics Committee of the Chinese Academy of Medical Sciences and the Peking Union Medical College Hospital. RESULTS: Significant negative correlation was observed between age and T2/ADC mean values. The T2 and ADC values showed significant differences among IVD levels and among age groups except for T2 values in age group 1 (25-34 years and group 2 (35-44 years, and for ADC values at L1-2 level. Both T2 and ADC values showed significant differences between young (age45 years at each IVD level. A linear relationship was observed between age and T2/ADC mean values in the elderly group as well as in the young group for the ADC mean values, while no such tendency was identified in the young group for the T2 mean values. CONCLUSIONS: ADC values may be a more sensitive parameter than T2 in assessing age and disc level related intervertebral disc changes.
Grabež, V; Kathri, M; Phung, V; Moe, K M; Slinde, E; Skaugen, M; Saarem, K; Egelandsdal, B
2015-04-01
Oxygen consumption rate (OCR) of muscle fibers from bovine semimembranosus muscle of 41 animals was investigated 3 to 4 h and 3 wk postmortem. Significant relations (P meat. Tender (22.92 ± 2.2 N/cm2) and tough (72.98 ± 7.2 N/cm2) meat samples (4 samples each), separated based on their OCR measurements, were selected for proteomic studies using mitochondria isolated approximately 2.5 h postmortem. Twenty-six differently expressed proteins (P meat and 19 in tough meat. In tender meat, the more prevalent antioxidant and chaperon enzymes may reduce reactive oxygen species and prolong oxygen removal by the electron transport system (ETS). Glycolytic, Krebs cycle, and ETS enzymes were also more abundant in tender meat
Nakahara, Hidehiro; Furuya, Shinichi; Obata, Satoshi; Masuko, Tsutomu; Kinoshita, Hiroshi
2009-07-01
The present study investigated the differential effects of emotions evoked by music on heart rate (HR) and its variability (HRV) during the playing of music on the piano compared to those in persons listening to the same music. Thirteen elite pianists underwent experiments under expressive piano playing, nonexpressive piano playing, expressive listening, and nonexpressive listening conditions. The expressive conditions produced significantly higher levels of HR and low-frequency component of HRV, as well as a lower level of its high-frequency component. A greater modulation of these was also revealed for performance than perception. The findings suggested that musical performance would lead to a greater effect of emotion-related modulation in cardiac autonomic nerve activity than musical perception.
Shah, Ajit; Bhandarkar, Ritesh
2008-10-01
Crime may be associated with a less structured society, less social integration, and feelings of less security and greater distress among citizens, which characteristics may lead to mental illness and subsequent suicide. Therefore, a cross-national analysis examining the association of general population suicide rates with percent of males and females in the population victimised by different categories of crime was undertaken using cross-national data from the World Health Organization and United Nations for 42 countries. Spearman correlations were generally weak and not statistically significant. Those values were at variance with the study's hypothesis and may be explained by several factors, including methodological issues. Individual-level case-control or cohort studies of suicides and attempted suicides in the general population may permit exploration of the relation of general population suicides with experience and percent by nations of being victimised by crime.
Min, Hua; Zheng, Ling; Perl, Yehoshua; Halper, Michael; De Coronado, Sherri; Ochs, Christopher
2017-05-18
Ontologies are knowledge structures that lend support to many health-information systems. A study is carried out to assess the quality of ontological concepts based on a measure of their complexity. The results show a relation between complexity of concepts and error rates of concepts. A measure of lateral complexity defined as the number of exhibited role types is used to distinguish between more complex and simpler concepts. Using a framework called an area taxonomy, a kind of abstraction network that summarizes the structural organization of an ontology, concepts are divided into two groups along these lines. Various concepts from each group are then subjected to a two-phase QA analysis to uncover and verify errors and inconsistencies in their modeling. A hierarchy of the National Cancer Institute thesaurus (NCIt) is used as our test-bed. A hypothesis pertaining to the expected error rates of the complex and simple concepts is tested. Our study was done on the NCIt's Biological Process hierarchy. Various errors, including missing roles, incorrect role targets, and incorrectly assigned roles, were discovered and verified in the two phases of our QA analysis. The overall findings confirmed our hypothesis by showing a statistically significant difference between the amounts of errors exhibited by more laterally complex concepts vis-à-vis simpler concepts. QA is an essential part of any ontology's maintenance regimen. In this paper, we reported on the results of a QA study targeting two groups of ontology concepts distinguished by their level of complexity, defined in terms of the number of exhibited role types. The study was carried out on a major component of an important ontology, the NCIt. The findings suggest that more complex concepts tend to have a higher error rate than simpler concepts. These findings can be utilized to guide ongoing efforts in ontology QA.
Physiological Study on the Relation of Heart Rate Variability in Ageing and Thyroid Hormone Disorder
Elsayed A. M. Shokr
2016-04-01
Full Text Available The present study aimed to investigate whether cardiac autonomic dysfunction in aging human might be related to an underlying thyroid disturbance. ageing has been associated with hypothyroidism and cardiac autonomic dysfunction. On the basis of body mass index (BMI, 150 patients were grouped into three groups (n = 50 48 years ± 2, 55 years ± 2 and 63 years ± 2. Electrocardiogram was recorded using PowerLab system and the time and frequency domain measures of heart rate variability (HRV were calculated. Fasting blood samples were drawn for measurement of serum thyroid stimulating hormone (TSH, total thyroxin (T4 and total triiodothyronine (T3 concentrations. The levels of TSH, T4 and T3 were not significantly different between the groups. The frequency domain HRV parameter reflecting parasympathetic tone (high-frequency normalized units, HFnu was significantly reduced in aging third groups group. The parameters which reflect sympathetic activation (Heart rate, low-frequency normalized units; LFnu and the LF/HF ratio were significantly increased in the aging group. HFnu was significantly and negatively correlated with age, whereas LFnu and LF/HF ratio were significantly and positively correlated with the above mentioned parameters. No significant relationships were noted between the HRV parameters and the levels of TSH or thyroid hormones. Cardiac autonomic dysfunction in aging human is not linked with underlying thyroid disturbance.
Exploring the Role of Galaxy Morphology in the Mass-Metallicity-Star Formation Rate Relation
Pahl, Anthony; Rafelski, Marc; Scarlata, Claudia; Pacifici, Camilla; Henry, Alaina L.; Gardner, Jonathan P.; Elmegreen, Debra M.
2017-01-01
The Mass-Metallicity-Star Formation Rate (M-Z-SFR) fundamental relation reveals the underlying physics behind galaxy evolution: the mechanics of gas inflow, outflow, and the formation of stars are intimately connected. At higher redshift, we observe galaxies which are believed to be more actively accreting from the cosmic web, and as a result bright star-forming clumps are expected to form due to the increased gravitational instability of the galactic medium. We investigate these “clumpy” galaxies in context of their location on the M-Z-SFR plane to search for evidence of metal-poor gas inflows as predicted by theoretical models, and to help us understand how galaxies form and change at a higher redshift (1.3 fundamental plane to investigate possible diminished metallicity and heightened star formation rate compared to the remainder of the sample. This will enable us to better understand the theoretical underpinnings of gas accretion and galaxy evolution at high redshift.
Longevity, growth rate and related traits among strains of Tribolium castaneum.
Soliman, M H; Lints, F A
1975-01-01
Longevity of eight laboratory strains of the flour beetle Tribolium castaneum, with various geographic backgrounds, was studied under constant laboratory conditions of 33 degrees C and 70% relative humidity in standard medium (95% whole wheat flour and 5% dried yeast) during a period of 227 days starting from the egg stage. The eggs were collected from the same parents, first a few days after emergence and afterwards at intervals of 13, 9, 10 and 11 days. Mean survival time (MST) was found to be strain-specified. It ranges from 128.6 days for KJ (Kyoto, Japan) to 174.2 days for ES (Edinburgh, Scotland). MST was highly correlated with the percentage of adults alive after 227 days, which did not change the ranking order of strain longevity. Parental age had no effect on longevity. The mean adult longevity of the strains was correlated with the available data on adult weight, growth rate, viability and productivity. There was no relationship between adult weight and longevity. LIfe span was found to depend on growth rate (measured as 13-day larval weight), percent viability (from 13-day larvae to adulthood) and productivity. Developmental time was also found to influence adult life span within certain limits (two extreme strains deviated). The data suggest that ageing and death in T. castaneum is under genetic control and support the idea that ageing, allied to development, is genetically controlled.
Anselmino, Matteo; Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca
2017-01-01
Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model. The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8). Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56). The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.
Does seed mass drive the differences in relative growth rate between growth forms?
Houghton, Jennie; Thompson, Ken; Rees, Mark
2013-07-07
The idea that herbaceous plants have higher relative growth rates (RGRs) compared with woody plants is fundamental to many of the most influential theories in plant ecology. This difference in growth rate is thought to reflect systematic variation in physiology, allocation and leaf construction. Previous studies documenting this effect have, however, ignored differences in seed mass. As woody species often have larger seeds and RGR is negatively correlated with seed mass, it is entirely possible the lower RGRs observed in woody species is a consequence of having larger seeds rather than different growth strategies. Using a synthesis of the published literature, we explored the relationship between RGR and growth form, accounting for the effects of seed mass and study-specific effects (e.g. duration of study and pot volume), using a mixed-effects model. The model showed that herbaceous species do indeed have higher RGRs than woody species, and that the difference was independent of seed mass, thus at all seed masses, herbaceous species on average grow faster than woody ones.
Negative Trends in Transport-related Mortality Rates in Broiler Chickens.
Vecerek, Vladimir; Voslarova, Eva; Conte, Francesca; Vecerkova, Lenka; Bedanova, Iveta
2016-12-01
The high incidence of deaths during transport for slaughter is associated with poor welfare and represents a considerable loss to the poultry industry. In the period from 2009 to 2014, all shipments of broiler chickens to poultry processing plants were monitored in the Czech Republic and the numbers of chickens transported and those dying as a result of their transport were recorded and analysed. Overall transport-related mortality of broiler chickens transported for slaughter in the Czech Republic was 0.37%. It ranged from 0.31% to 0.72%, the increase approximately corresponding to the increasing transport distance. Statistically highly significant (prates in individual seasons of the year. The greatest mortality (0.55%) was associated with transports carried out in winter months whereas the lowest death losses (0.30%) were found in chickens transported for slaughter in summer months. Our study revealed greater transport-related mortality rates in broiler chickens transported for slaughter in the Czech Republic than expected when considering earlier studies. The most pronounced increases were found in transports for shorter distances and in winter months. However, an increase was found at all transport distances monitored except for distances exceeding 300 km and all seasons except for summer. Furthermore, a general increasing tendency in chicken losses during the monitored period was found. The particularly alarming finding is that the mortality of broiler chickens being transported to processing plants has been showing a long-term increasing tendency over the last two decades. Further research should focus on the identification of specific factors leading to such high and growing mortality rates and developing practical guidelines to improve the welfare of the birds in transit accordingly.
Chen, S.R.; Gray, G.T. III; Bingert, S.R. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.
1996-05-01
Tantalum and its alloys have received increased interest as a model bcc metal and for defense-related applications. The stress-strain behavior of several tantalums, possessing varied compositions and manufacturing histories, and tantalum alloyed with tungsten, was investigated as a function of temperature from {minus}196 C to 1,000 C, and strain rate from 10{sup {minus}3} s{sup {minus}1} to 8,000 s{sup {minus}1}. The yield stress for all the Ta-materials was found to be sensitive to the test temperature, the impurity and solute contents; however, the strain hardening remained very similar for various ``pure`` tantalums but increased with alloying. Powder-metallurgy (P/M) tantalum with various levels of oxygen content produced via different processing paths was also investigated. Similar mechanical properties compared to conventionally processed tantalums were achieved in the P/M Ta. This data suggests that the frequently observed inhomogeneities in the mechanical behavior of tantalum inherited from conventional processes can be overcome. Constitutive relations based upon the Johnson-Cook, the Zerilli-Armstrong, and the Mechanical Threshold Stress models were evaluated for all the Ta-based materials. Parameters were also fit for these models to a tantalum-bar material. Flow stresses of a Ta bar stock subjected to a large-strain deformation of {var_epsilon} = 1.85 via multiple upset forging were obtained. The capabilities and limitations of each model for large-strain applications are examined. The deformation mechanisms controlling high-rate plasticity in tantalum are revisited.
Chin, Brian; Nelson, Brady D; Jackson, Felicia; Hajcak, Greg
2016-01-01
Fear conditioning research on threat predictability has primarily examined the impact of temporal (i.e., timing) predictability on the startle reflex. However, there are other key features of threat that can vary in predictability. For example, the reinforcement rate (i.e., frequency) of threat is a crucial factor underlying fear learning. The present study examined the impact of threat reinforcement rate on the startle reflex and self-reported anxiety during a fear conditioning paradigm. Forty-five participants completed a fear learning task in which the conditioned stimulus was reinforced with an electric shock to the forearm on 50% of trials in one block and 75% of trials in a second block, in counter-balanced order. The present study also examined whether intolerance of uncertainty (IU), the tendency to perceive or experience uncertainty as stressful or unpleasant, was associated with the startle reflex during conditions of low (50%) vs. high (75%) reinforcement. Results indicated that, across all participants, startle was greater during the 75% relative to the 50% reinforcement condition. IU was positively correlated with startle potentiation (i.e., increased startle response to the CS+ relative to the CS-) during the 50%, but not the 75%, reinforcement condition. Thus, despite receiving fewer electric shocks during the 50% reinforcement condition, individuals with high IU uniquely demonstrated greater defense system activation when impending threat was more uncertain. The association between IU and startle was independent of state anxiety. The present study adds to a growing literature on threat predictability and aversive responding, and suggests IU is associated with abnormal responding in the context of uncertain threat.
Lens-Pechakova, Lilia S
2016-02-01
The autoimmune diseases are among the 10 leading causes of death for women and the number two cause of chronic illness in America as well as a predisposing factor for cardiovascular diseases and cancer. Patients of some autoimmune diseases have shown a shorter life span and are a model of accelerated immunosenescence. Conversely, centenarians are used as a model of successful aging and have shown several immune parameters that are better preserved and lower levels of autoantibodies. The study reported here focused on clarifying the connection between longevity and some autoimmune and allergic diseases in 29 developed Organisation for Economic Co-operation and Development (OECD) countries, because multidisciplinary analyses of the accelerated or delayed aging data could show a distinct relationship pattern, help to identify common factors, and determine new important factors that contribute to longevity and healthy aging. The relationships between the mortality rates data of multiple sclerosis (MS), rheumatoid arthritis (RA), asthma, the incidence of type 1 diabetes (T1D) from one side and centenarian rates (two sets) as well as life expectancy data from the other side were assessed using regression models and Pearson correlation coefficients. The data obtained correspond to an inverse linear correlation with different degrees of linearity. This is the first observation of a clear tendency of diminishing centenarian rates or life expectancy in countries having higher death rates of asthma, MS, and RA and a higher incidence of T1D in children. The conclusion is that most probably there are common mechanistic pathways and factors affecting the above diseases and at the same time but in the opposite direction the processes of longevity. Further study, comparing genetic data, mechanistic pathways, and other factors connected to autoimmune diseases with those of longevity could clarify the processes involved, so as to promote longevity and limit the expansion of those
Gorenstein Hilbert Coefficients
Khoury, Sabine El
2012-01-01
We prove upper and lower bounds for all the coefficients in the Hilbert Polynomial of a graded Gorenstein algebra $S=R/I$ with a quasi-pure resolution over $R$. The bounds are in terms of the minimal and the maximal shifts in the resolution of $R$ . These bounds are analogous to the bounds for the multiplicity found in \\cite{S} and are stronger than the bounds for the Cohen Macaulay algebras found in \\cite{HZ}.
Balaganesh, M; Rajakumar, B
2012-10-11
The rate coefficients of ((E)-CF(3)CH═CHF, (Z)-CF(3)CH═CHF, (E)-CF(3)CF═CHF, and (Z)-CF(3)CF═CHF) + OH reactions were computed using M06-2X/6-31+G(d,p) theory in the temperature range of 200 and 400 K. The possible reaction mechanisms of the ((E)-CF(3)CH═CHF, (Z)-CF(3)CH═CHF, (E)-CF(3)CF═CHF, and (Z)-CF(3)CF═CHF) + OH reactions were examined. The rate coefficients for the addition and abstraction reactions were calculated using canonical variational transition state theory (CVT) and conventional transition state theory (CTST), respectively, and we concluded that abstraction reactions are negligible within the temperature range and addition reactions take the lead role. The small curvature tunnelling (SCT) was included in the computation of the rate coefficients. The temperature dependent rate expressions (in cm(3) molecule(-1) s(-1)) of the (E)-CF(3)CH═CHF, (Z)-CF(3)CH═CHF, (E)-CF(3)CF═CHF, and (Z)-CF(3)CF═CHF + OH reactions between 200 and 400 K are presented. The atmospheric lifetimes and global warming potentials (GWPs) of the test molecules were computed using the rate coefficients obtained in this study, and it is concluded that these molecules are very short-lived in the Earth's atmosphere with low GWPs.
Heat transfer coefficient of cryotop during freezing.
Li, W J; Zhou, X L; Wang, H S; Liu, B L; Dai, J J
2013-01-01
Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rate. Recently, the heat transfer performance of cryotop was studied by numerical simulation in several studies. However, the range of heat transfer coefficient in the simulation is uncertain. In this study, the heat transfer coefficient for cryotop during freezing process was analyzed. The cooling rates of 40 percent ethylene glycol (EG) droplet in cryotop during freezing were measured by ultra-fast measurement system and calculated by numerical simulation at different value of heat transfer coefficient. Compared with the results obtained by two methods, the range of the heat transfer coefficient necessary for the numerical simulation of cryotop was determined, which is between 9000 W/(m(2)·K) and 10000 W/(m (2)·K).
Rate of learning and asymptotic performance in an automatization task and the relation to reading.
Hecht, Rozalia; Crewther, David; Crewther, Sheila
2004-12-01
In the present study, direct evidence was sought linking cognitive automatic processing with reading in the general adult population. Reading speed on single-task performance and dual-task performance were compared. A total of 18 adults without dyslexia participated (7 men and 11 women, age M=25.3 yr., SD=2.7). Participants initially were trained in single-task mode on two types of tasks. The first was a central alphanumeric equation task (true or false), which comprised 3 subtests of increasing difficulty, ranging from an easily automated task to a varied and unpredictable mathematical operation. The second task was a peripheral pattern subitization task for which stimulus exposure time was related to performance. Finally, participants received dual-task training, which required simultaneous processing of both tasks. Slower reading speed was significantly related to rate of learning and speed of performance on predictable alphanumeric operations in dual-task conditions. There was no effect of reading speed on performance in the varied alphanumeric task. Faster readers were no better than slower readers on the pattern-subitization task. These findings suggest that faster readers automatized the predictable alphanumeric task more rapidly than slower readers and hence were better able to cope with the dual-task condition.
Das, Saurabh; Maitra, Animesh
2017-03-01
Characterization of precipitation is important for proper interpretation of rain information from remotely sensed data. Rain attenuation and radar reflectivity (Z) depend directly on the drop size distribution (DSD). The relation between radar reflectivity/rain attenuation and rain rate (R) varies widely depending upon the origin, topography, and drop evolution mechanism and needs further understanding of the precipitation characteristics. The present work utilizes 2 years of concurrent measurements of DSD using a ground-based disdrometer at five diverse climatic conditions in Indian subcontinent and explores the possibility of rain classification based on microphysical characteristics of precipitation. It is observed that both gamma and lognormal distributions are performing almost similar for Indian region with a marginally better performance by one model than other depending upon the locations. It has also been found that shape-slope relationship of gamma distribution can be a good indicator of rain type. The Z-R relation, Z = ARb, is found to vary widely for different precipitation systems, with convective rain that has higher values of A than the stratiform rain for two locations, whereas the reverse is observed for the rest of the three locations. Further, the results indicate that the majority of rainfall (>50%) in Indian region is due to the convective rain although the occurrence time of convective rain is low (<10%).
Large-scale variation in boreal and temperate forest carbon turnover rate related to climate
Thurner, Martin; Beer, Christian; Carvalhais, Nuno; Forkel, Matthias; Santoro, Maurizio; Tum, Markus; Schmullius, Christiane
2016-05-01
Vegetation carbon turnover processes in forest ecosystems and their dominant drivers are far from being understood at a broader scale. Many of these turnover processes act on long timescales and include a lateral dimension and thus can hardly be investigated by plot-level studies alone. Making use of remote sensing-based products of net primary production (NPP) and biomass, here we show that spatial gradients of carbon turnover rate (k) in Northern Hemisphere boreal and temperate forests are explained by different climate-related processes depending on the ecosystem. k is related to frost damage effects and the trade-off between growth and frost adaptation in boreal forests, while drought stress and climate effects on insects and pathogens can explain an elevated k in temperate forests. By identifying relevant processes underlying broadscale patterns in k, we provide the basis for a detailed exploration of these mechanisms in field studies, and ultimately the improvement of their representations in global vegetation models (GVMs).
Biofeedback of heart rate variability and related physiology: a critical review.
Wheat, Amanda L; Larkin, Kevin T
2010-09-01
Low heart rate variability (HRV) characterizes several medical and psychological diseases. HRV biofeedback is a newly developed approach that may have some use for treating the array of disorders in which HRV is relatively low. This review critically appraises evidence for the effectiveness of HRV and related biofeedback across 14 studies in improving (1) HRV and baroreflex outcomes and (2) clinical outcomes. Results revealed that HRV biofeedback consistently effectuates acute improvements during biofeedback practice, whereas the presence of short-term and long-term carry-over effects is less clear. Some evidence suggests HRV biofeedback may result in long-term carry-over effects on baroreflex gain, which is an area most promising for future investigations. On the other hand, concerning clinical outcomes, there is ample evidence attesting to efficacy of HRV biofeedback. However, because clinical and physiological outcomes do not improve concurrently in all cases, the mechanism by which HRV biofeedback results in salutary effects in unclear. Considerations for the field in addressing shortcomings of the reviewed studies and advancing understanding of the way in which HRV biofeedback may improve physiological and clinical outcomes are offered in light of the reviewed evidence.
Relative rates of B meson decays into psi(2S) and J/psi mesons
Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguiló, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; sman, B; Assis-Jesus, A C S; Atramentov, O; Avila, C; Badaud, F; Baden, A A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besanon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Böhnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Bunichev, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K; Chan, K M; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M C; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Davies, G; De, K; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Dliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; García, C; García-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gel, D; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gmez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Kalk, J M; Karmanov, D; Kasper, P A; Katsanos, I; Kau, D; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Yu M; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J P; Kozelov, A V; Kraus, J; Krop, D; Kühl, T; Kumar, A; Kupco, A; Kura, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Lévêque, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajícek, M; Love, P; Lubatti, H J; Luna, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Millet, T; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osman, N; Osta, J; Otec, R; Oteroy Garzn, G J; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Polozov, P; Pope, B G; Popov, A V; Potter, C; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rieger, J; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Salzmann, C; Snchez-Hernndez, A; Sanders, M P; Sanghi, B; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simák, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, E; Strauss, M; Strhomer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Tamburello, P; Tanasijczuk, A; Taylor, W; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; vanden Berg, P J; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Séguier, F; Vint, P; Vokac, P; Von Törne, E; Voutilainen, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Welty-Rieger, L; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G
2008-01-01
We report on a study of the relative rates of B meson decays into psi(2S) and J/psi mesons using 1.3 fb^-1 of pbar p collisions at sqrt(s) = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels B^0_s -> psi(2S)phi, B^0_s -> J/psi phi, B^+/- -> psi(2S) K^+/-, and B^+/- -> J/psi K^+/- and we measure the relative branching fractions for these channels to be B(B^0_s -> psi(2S)phi)/B(B^0_s -> J/psi phi) = 0.55 +/- 0.11 (stat) +/- 0.07 (syst) +/- 0.06 (B), B(B^+/- -> psi(2S) K^+/-)/B(B^+/- -> J/psi K^+/-) = 0.65 +/- 0.04 (stat) +/- 0.03 (syst) +/- 0.07 (B) where the final error corresponds to the uncertainty in the J/psi and psi(2S) branching ratio into two muons.
The Radio Continuum-Star Formation Rate Relation in WSRT SINGS Galaxies
Heesen, Volker; Leroy, Adam K; Heald, George; Braun, Robert; Bigiel, Frank; Beck, Rainer
2014-01-01
We study the spatially resolved Radio Continuum-Star Formation Rate (RC-SFR) relation using state-of-the-art star-formation (SF) tracers in a sample of 17 THINGS galaxies. We use hybrid Sigma_SFR maps (GALEX FUV plus Spitzer 24 mu), RC maps at 22/18 cm from the WSRT SINGS survey, and H-alpha maps to correct for thermal RC emission. We compare azimuthally averaged radial profiles of the RC and FUV/MIR-based Sigma_SFR maps and study pixel-by-pixel correlations at fixed linear scales of 1.2 and 0.7 kpc. The ratio of the integrated SFRs from the RC emission to that of the FUV/MIR-based SF tracers is R_int = 0.78 +/- 0.38, consistent with Condon's relation. We find a tight correlation between the radial profiles of the radio and FUV/MIR-based Sigma_SFR for the entire extent of the disk. The ratio R of the azimuthally averaged radio to FUV/MIR-based Sigma_SFR agrees with the integrated ratio with only small quasi-random fluctuations as function of radius. Pixel-by-pixel plots show a tight correlation in log-log dia...
Flume experiments of deposition rate on foreset of silty delta relative to hydrographic patterns
SUZUKI Taro; ENDO Noritaka
2011-01-01
Foreset profiles of deltaic topography change corresponding to hydraulic conditions, and are influenced by water discharge and change rates of water discharge. To investigate the correlation between the transition of deposition rates on the foreset and the change rate of water discharge of temporary waxing and subsequent waning lfows, we perform experiments on silty deltas that developed under several different hydrographic patterns. The ifndings are as follows: (1) Under lfows with constant discharge, the deposition rate on the foreset was low at high water discharge and high at low water discharge because the separated lfow became vigorous at high water discharge and prevented sediment supply onto the foreset. If the water discharge is not constant, the deposition rate shifted concurrently with water discharge only at extremely low change rate. (2i) In a waxing lfow at low (but not extremely low) increase rate, the deposition rate gradually decreased with some time lag. (2ii) In the case of high increase discharge, intense erosion on the topset caused by rapid waxing made a large amount of silt move onto the foreset and the deposition rate temporary increased. (3) With ample time after waning stage, the deposition rate recovered to that at constant low water discharge in all runs. However, the transitional processes depended on not only waning rate but also waxing rate at before waning stage. (3i) In the case of high decrease rate of water discharge, the deposition rate abruptly decreased regardless of increase rate. (3ii) Even in the case of low decrease rate of water discharge, if the increase rate before waning stage was high, the deposition rate abruptly decreased. (3iii) Only in the case where both the increase rate and the decrease rate were low, deposition rate gradually increased.
Moore, Nathan T.; May, David C.; Wood, Peter B.
2008-01-01
Recent work suggests that offenders rate several alternatives as more severe than imprisonment. We build on this literature by comparing punishment exchange rates generated by criminal court judges with rates generated by offenders and their supervising officers. Findings reveal that none of the three groups rates prison as the most severe…
Khandoker, Ahsan H.; Al-Angari, Haitham M.; Khalaf, Kinda; Lee, Sungmun; Almahmeed, Wael; Al Safar, Habiba S.
2017-01-01
Microvascular, macrovascular and neurological complications are the key causes of morbidity and mortality among type II diabetes mellitus (T2DM) patients. The aim of this study was to investigate the alterations of cardiac autonomic function of diabetic patients in relation to three types of diabetes-related complications. ECG recordings were collected and analyzed from 169 T2DM patients in supine position who were diagnosed with nephropathy (n = 55), peripheral neuropathy (n = 64) and retinopathy (n = 106) at two hospitals in the UAE. Comparison between combinations of patients with complications and a control diabetic group (CONT) with no complication (n = 34) was performed using time, frequency and multi-lag entropy measures of heart rate variability (HRV). The results show that these measures decreased significantly (p<0.05) depending on the presence and type of diabetic complications. Entropy, (median, 1st- 3rd interquartile range) for the group combining all complications (1.74,1.37–2.09) was significantly lower than the corresponding values for the CONT group (1.77, 1.39–2.24) with lag-1 for sequential beat-to-beat changes. Odds ratios (OR) from the entropy analysis further demonstrated a significantly higher association with the combination of retinopathy and peripheral neuropathy versus CONT (OR: 1.42 at lag 8) and an even OR for the combination of retinopathy and nephropathy (OR: 2.46 at lag 8) compared to the other groups with complications. Also, the OR of low frequency power to high frequency power ratio (LF/HF) showed a higher association with these diabetic-related complications compared to CONT, especially for the patient group combining all complications (OR: 4.92). This study confirms that the type of microvascular or peripheral neuropathy complication present in T2DM patients have different effects on heart rate entropy, implying disorders of multi-organ connectivity are directly associated with autonomic nervous system dysfunction. Clinical
On the Rate of Relaxation for the Landau Kinetic Equation and Related Models
Bobylev, Alexander; Gamba, Irene M.; Zhang, Chenglong
2017-08-01
We study the rate of relaxation to equilibrium for Landau kinetic equation and some related models by considering the relatively simple case of radial solutions of the linear Landau-type equations. The well-known difficulty is that the evolution operator has no spectral gap, i.e. its spectrum is not separated from zero. Hence we do not expect purely exponential relaxation for large values of time t>0. One of the main goals of our work is to numerically identify the large time asymptotics for the relaxation to equilibrium. We recall the work of Strain and Guo (Arch Rat Mech Anal 187:287-339 2008, Commun Partial Differ Equ 31:17-429 2006), who rigorously show that the expected law of relaxation is \\exp (-ct^{2/3}) with some c > 0. In this manuscript, we find an heuristic way, performed by asymptotic methods, that finds this "law of two thirds", and then study this question numerically. More specifically, the linear Landau equation is approximated by a set of ODEs based on expansions in generalized Laguerre polynomials. We analyze the corresponding quadratic form and the solution of these ODEs in detail. It is shown that the solution has two different asymptotic stages for large values of time t and maximal order of polynomials N: the first one focus on intermediate asymptotics which agrees with the "law of two thirds" for moderately large values of time t and then the second one on absolute, purely exponential asymptotics for very large t, as expected for linear ODEs. We believe that appearance of intermediate asymptotics in finite dimensional approximations must be a generic behavior for different classes of equations in functional spaces (some PDEs, Boltzmann equations for soft potentials, etc.) and that our methods can be applied to related problems.
The Truth About Ballistic Coefficients
Courtney, Michael
2007-01-01
The ballistic coefficient of a bullet describes how it slows in flight due to air resistance. This article presents experimental determinations of ballistic coefficients showing that the majority of bullets tested have their previously published ballistic coefficients exaggerated from 5-25% by the bullet manufacturers. These exaggerated ballistic coefficients lead to inaccurate predictions of long range bullet drop, retained energy and wind drift.
The radio continuum-star formation rate relation in WSRT sings galaxies
Heesen, Volker; Brinks, Elias [Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Heald, George [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Braun, Robert [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Bigiel, Frank [Institut für theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Beck, Rainer, E-mail: e.brinks@herts.ac.uk, E-mail: v.heesen@soton.ac.uk, E-mail: aleroy@nrao.edu, E-mail: heald@astron.nl, E-mail: Robert.Braun@csiro.au, E-mail: bigiel@uni-heidelberg.de, E-mail: rbeck@mpifr-bonn.mpg.de [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
2014-05-01
We present a study of the spatially resolved radio continuum-star formation rate (RC-SFR) relation using state-of-the-art star formation tracers in a sample of 17 THINGS galaxies. We use SFR surface density (Σ{sub SFR}) maps created by a linear combination of GALEX far-UV (FUV) and Spitzer 24 μm maps. We use RC maps at λλ22 and 18 cm from the WSRT SINGS survey and Hα emission maps to correct for thermal RC emission. We compare azimuthally averaged radial profiles of the RC and FUV/mid-IR (MIR) based Σ{sub SFR} maps and study pixel-by-pixel correlations at fixed linear scales of 1.2 and 0.7 kpc. The ratio of the integrated SFRs from the RC emission to that of the FUV/MIR-based SF tracers is R{sub int}=0.78±0.38, consistent with the relation by Condon. We find a tight correlation between the radial profiles of the radio and FUV/MIR-based Σ{sub SFR} for the entire extent of the disk. The ratio R of the azimuthally averaged radio to FUV/MIR-based Σ{sub SFR} agrees with the integrated ratio and has only quasi-random fluctuations with galactocentric radius that are relatively small (25%). Pixel-by-pixel plots show a tight correlation in log-log diagrams of radio to FUV/MIR-based Σ{sub SFR}, with a typical standard deviation of a factor of two. Averaged over our sample we find (Σ{sub SFR}){sub RC}∝(Σ{sub SFR}){sub hyb}{sup 0.63±0.25}, implying that data points with high Σ{sub SFR} are relatively radio dim, whereas the reverse is true for low Σ{sub SFR}. We interpret this as a result of spectral aging of cosmic-ray electrons (CREs), which are diffusing away from the star formation sites where they are injected into the interstellar medium. This is supported by our finding that the radio spectral index is a second parameter in pixel-by-pixel plots: those data points dominated by young CREs are relatively radio dim, while those dominated by old CREs are slightly more RC bright than what would be expected from a linear extrapolation. We studied the ratio R of
Shah, Chirag [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States); Vicini, Frank A., E-mail: fvicini@beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States)
2011-11-15
As more women survive breast cancer, long-term toxicities affecting their quality of life, such as lymphedema (LE) of the arm, gain importance. Although numerous studies have attempted to determine incidence rates, identify optimal diagnostic tests, enumerate efficacious treatment strategies and outline risk reduction guidelines for breast cancer-related lymphedema (BCRL), few groups have consistently agreed on any of these issues. As a result, standardized recommendations are still lacking. This review will summarize the latest data addressing all of these concerns in order to provide patients and health care providers with optimal, contemporary recommendations. Published incidence rates for BCRL vary substantially with a range of 2-65% based on surgical technique, axillary sampling method, radiation therapy fields treated, and the use of chemotherapy. Newer clinical assessment tools can potentially identify BCRL in patients with subclinical disease with prospective data suggesting that early diagnosis and management with noninvasive therapy can lead to excellent outcomes. Multiple therapies exist with treatments defined by the severity of BCRL present. Currently, the standard of care for BCRL in patients with significant LE is complex decongestive physiotherapy (CDP). Contemporary data also suggest that a multidisciplinary approach to the management of BCRL should begin prior to definitive treatment for breast cancer employing patient-specific surgical, radiation therapy, and chemotherapy paradigms that limit risks. Further, prospective clinical assessments before and after treatment should be employed to diagnose subclinical disease. In those patients who require aggressive locoregional management, prophylactic therapies and the use of CDP can help reduce the long-term sequelae of BCRL.
Killen, Shaun S; Reid, Donald; Marras, Stefano; Domenici, Paolo
2015-01-01
When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fueled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope (AS) or recovery time after exhaustive exercise. Slower recovery ability or a reduced AS could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how AS and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden gray mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26°C, then measured for standard and maximal metabolic rates and AS using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasize that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with vigilance and recovery from anaerobic exercise.
Shaun Steven Killen
2015-04-01
Full Text Available When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fuelled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope or recovery time after exhaustive exercise. Slower recovery ability or a reduced aerobic scope could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how aerobic scope and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden grey mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26oC, then measured for standard and maximal metabolic rates and aerobic scope using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasise that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with
MA; Yingjun
2001-01-01
［1］Ma, Y. J., Liu, C. Q., Geochemistry of strontium isotopes in the crust weathering system, Acta Mineralogica Sinica (in Chinese), 1998, 18(3): 350.［2］Ma, Y. J., Liu, C. Q., Using strontium isotopes to trace nutrient element circulation and hydrochemical evolution within an ecosystem, Advance in Earth Sciences (in Chinese), 1999, 14 (4): 377.［3］Brantley, S. L., Chesley, J. T., Stillings, L. L., Isotopic ratios and release rates of strontium from weathering feldspars, Geochim. Cosmochim. Acta, 1998, 62(9): 1493.［4］Blum, J. D., Erel, Y., A silicate weathering mechanism linking increases in marine 87Sr/86Sr with global glaciation, Nature, 1995, 373: 415.［5］Blum, J. D., Erel, Y., Rb-Sr isotope systematics of granitic soil chronosequence: The importance of biotite weathering, Geochim. Cosmochim. Acta, 1997, 61(15): 3193.［6］Bullen, T., Krabbenhoft, D., Kendall, C., Kinetic and mineralogic controls on the evolution of groundwater chemistry and 87Sr/86Sr in a sandy silicate aquifer, northern Wisconsin, USA, Geochim. Cosmochim. Acta, 1996, 60: 1807.［7］Bullen, T., White, A., Blum, A. et al., Chemical weathering of a soil chronosequence on granitoid alluvium: Ⅱminer-alogic and isotopic constraints on the behavior of strontium, Geochim. Cosmochim. Acta, 1997, 61: 291.［8］Blum, J. D., Erel, Y., Brown, K., 87Sr/86Sr ratios of Sierra Nevada stream waters: Implications for relative mineral weath-ering rates, Geochim. Cosmochim. Acta, 1993, 57: 5019.［9］Ma Yingjun, Trace element and strontium isotope geochemistry during chemical weathering, Ph. D. Dissertation, 1999, Institute of Geochemistry, Chinese Academy of Sciences.［10］Nesbitt, H. W., Markovics, G., Price, R. C., Chemical processes affecting alkalis and alkaline earths during continental weathering, Geochim. Cosmochim. Acta, 1980, 44: 1659.［11］Clauer, N., Strontium and argon isotopes in naturally weathered biotites, muscovites and feldspars, Chem. Geol., 1981, 31: 325.［12
Comprehensive analysis of the optical Kerr coefficient of graphene
Soh, Daniel B. S.; Hamerly, Ryan; Mabuchi, Hideo
2016-08-01
We present a comprehensive analysis of the nonlinear optical Kerr effect in graphene. We directly solve the S -matrix element to calculate the absorption rate, utilizing the Volkov-Keldysh-type crystal wave functions. We then convert to the nonlinear refractive index coefficients through the Kramers-Kronig relation. In this formalism, the source of Kerr nonlinearity is the interplay of optical fields that cooperatively drive the transition from valence to conduction band. This formalism makes it possible to identify and compute the rates of distinct nonlinear processes that contribute to the Kerr nonlinear refractive index coefficient. The four identified mechanisms are two-photon absorption, Raman transition, self-coupling, and quadratic ac Stark effect. We also present a comparison of our theory with recent experimental and theoretical results.
Estimation of the simple correlation coefficient.
Shieh, Gwowen
2010-11-01
This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.
Relation between attempted suicide and suicide rates among young people in Europe
Hawton, K.; Arensman, E.; Wasserman, D.; Hulten, A.; Bille-Brahe, U.; Bjerke, T.; Crepet, P.; Deisenhammer, E; Kerkhof, A.; De Leo, D; Michel, K.; Ostamo, A.; Philippe, A.; I. Querejeta; Salander-Renberg, E.
1998-01-01
STUDY OBJECTIVE: To determine if there are associations between rates of suicide and attempted suicide in 15-24 year olds in different countries in Europe. DESIGN: Attempted suicide rates were based on data collected in centres in Europe between 1989 and 1992 as part of the WHO/EURO Multicentre Study of Parasuicide. Comparison was made with both national suicide rates and local suicide rates for the areas in which the attempted suicide monitoring centres are based. SETTING: 15 centres i...
The Star Formation Rate - Dense Gas Relation in the Nuclei of Nearby Galaxies
Narayanan, Desika; Hernquist, Lars
2008-01-01
We investigate the relationship between the star formation rate (SFR) and dense molecular gas mass in the nuclei of galaxies. To do this, we utilize the observed 850 micron luminosity as a proxy for the infrared luminosity and SFR, and correlate this with the observed CO (J=3-2) luminosity. We find tentative evidence that the LIR-CO (J=3-2) index is similar to the Kennicutt-Schmidt (KS) index (N ~ 1.5) in the central ~1.7 kpc of galaxies, and flattens to a roughly linear index when including emission from the entire galaxy. This result may imply that the volumetric Schmidt relation is the underlying driver behind the observed SFR-dense gas correlations, and provides tentative confirmation for recent numerical models. While the data exclude the possibility of a constant LIR-CO (J=3-2) index for both galaxy nuclei and global measurements at the ~80% confidence level, the considerable error bars cannot preclude alternative interpretations.
Gang Li; Zhihua Wang; Canjing Zhang; Yang Wang
2008-01-01
Objectlves To stuaythe relationship between plasma hemoglobin concentration and estimated glomerular filtration rate (eGFR)in elderly patients with ischemic cardiomyopathy (ICM).Methods Clinical data of patients with coronary heart disease who weredischarged from The First Affiliated Hospital,Chongqing Medicai University between 2005 and 2007 were analyzed retrospectively.Echocardiography resuIts.plasma hemoglobin and creatinine concentration were abstracted from the medical records.The study included235 Chinese Han patients with age 60 years and older with angiography confwmed coronary heart disease.silent myocardial ischemia orangina pectoris,of whom 154 had ICM defined as left ventricular end-diastolic diameter(LVDd),male≥56mm,female≥51 mm(63.51±7.70 mm)measured by M-mode echocardiography.The differences in plasma hemoglobin concentration were analyzed retrospec-were no significant changes in plasma hemoglobin concentration and eGFR;however,plasma hernoglobin concentration was related toeGFR significantly positively in elderly patients with ICM due to coronary heart disease.
Wilson, Michael J
2016-01-01
I investigate the consistency of the VIMOS Public Extragalactic Redshift Survey v7 galaxy sample with the expansion history and linear growth rate predicted by General Relativity (GR) and a Planck (2015) cosmology. To do so, I measure the redshift-space power spectrum, which is anisotropic due to both redshift-space distortions (RSD) and the Alcock-Paczynski (AP) effect. In Chapter 6, I place constraints of $f \\sigma_8(0.76) = 0.44 \\pm 0.04$ and $f \\sigma_8(1.05) = 0.28 \\pm 0.08$, which remain consistent with GR at 95% confidence. Marginalising over the anisotropic AP effect degrades the constraints by a factor of three but allows $F_{AP} \\equiv (1+z) D_A H/c$ to be simultaneously constrained. The VIPERS v7 joint-posterior on $(f \\sigma_8, F_{AP})$ shows no compelling deviation from GR. Chapter 7 investigates the inclusion of a simple density transform: `clipping' prior to the RSD analysis. This tackles the root-cause of non-linearity and may extend the validity of perturbation theory. Moreover, this marked s...
Brain areas controlling heart rate variability in tinnitus and tinnitus-related distress.
Sven Vanneste
Full Text Available BACKGROUND: Tinnitus is defined as an intrinsic sound perception that cannot be attributed to an external sound source. Distress in tinnitus patients is related to increased beta activity in the dorsal part of the anterior cingulate and the amount of distress correlates with network activity consisting of the amygdala-anterior cingulate cortex-insula-parahippocampus. Previous research also revealed that distress is associated to a higher sympathetic (OS tone in tinnitus patients and tinnitus suppression to increased parasympathetic (PS tone. METHODOLOGY: The aim of the present study is to investigate the relationship between tinnitus distress and the autonomic nervous system and find out which cortical areas are involved in the autonomic nervous system influences in tinnitus distress by the use of source localized resting state electroencephalogram (EEG recordings and electrocardiogram (ECG. Twenty-one tinnitus patients were included in this study. CONCLUSIONS: The results indicate that the dorsal and subgenual anterior cingulate, as well as the left and right insula are important in the central control of heart rate variability in tinnitus patients. Whereas the sympathovagal balance is controlled by the subgenual and pregenual anterior cingulate cortex, the right insula controls sympathetic activity and the left insula the parasympathetic activity. The perceived distress in tinnitus patients seems to be sympathetically mediated.
Kruijssen, J. M. Diederik; Bastian, Nate
2016-03-01
Stars generally form in aggregates, some of which are bound (`clusters') while others are unbound and disperse on short ({˜ }10 { Myr}) time-scales (`associations'). The fraction of stars forming in bound clusters (Γ) is a fundamental outcome of the star formation process. Recent observational and theoretical work has suggested that Γ increases with the gas surface density (Σ) or star formation rate (SFR) surface density (ΣSFR), both within galaxies and between different ones. However, a recent paper by Chandar et al. has challenged these results, showing that the total number of stellar aggregates per unit SFR does not vary systematically with the host galaxy's absolute SFR. In this Letter, we show that no variations are expected when no distinction is made between bound and unbound aggregates, because the sum of these two fractions should be close to unity. We also demonstrate that any scaling of Γ with the absolute SFR is much weaker than with ΣSFR, due to the mass-radius-SFR relation of star-forming `main-sequence' galaxies. The environmental variation of Γ should therefore be probed as a function of area-normalized quantities, such as Σ or ΣSFR. We present a set of guidelines for meaningful observational tests of cluster formation theories and show that these resolve the reported discrepancy.
李磊; 谢小璐
2013-01-01
The paper uses six indicators to reflect urban and rural financial development level of China.Then it uses the grey relational analysis model to analyze the impacts of financial development in urban and rural areas on Gini coefficient from 2003 to 2011.The results show that financial structure,the efficiency of financial intermediation,input-output ratio of fixed asset and financial industry labor have the greatest influences on Gini coefficient.Finally,it puts forward the financial measures to reduce the income gap between urban and rural residents.%用6个指标反映中国城乡金融发展水平,并利用灰色关联分析模型,分析2003-2011年中国城乡金融发展对基尼系数的影响.研究结果显示:金融结构、金融中介效率、固定资产投入产出比和金融行业劳动力对基尼系数的影响最大.最后提出缩短城乡居民收入差距的金融对策.
Eganhouse, Robert P.
2016-01-01
Polymer-water partition coefficients (Kpw) of ten DDT-related compounds were determined in pure water at 25 °C using commercial polydimethylsiloxane-coated optical fiber. Analyte concentrations were measured by thermal desorption-gas chromatography/full scan mass spectrometry (TD–GC/MSFS; fibers) and liquid injection-gas chromatography/selected ion monitoring mass spectrometry (LI–GC/MSSIM; water). Equilibrium was approached from two directions (fiber uptake and depletion) as a means of assessing data concordance. Measured compound-specific log Kpw values ranged from 4.8 to 6.1 with an average difference in log Kpw between the two approaches of 0.05 log units (∼12% of Kpw). Comparison of the experimentally-determined log Kpw values with previously published data confirmed the consistency of the results and the reliability of the method. A second experiment was conducted with the same ten DDT-related compounds and twelve selected PCB (polychlorinated biphenyl) congeners under conditions characteristic of a coastal marine field site (viz., seawater, 11 °C) that is currently under investigation for DDT and PCB contamination. Equilibration at lower temperature and higher ionic strength resulted in an increase in log Kpw for the DDT-related compounds of 0.28–0.49 log units (61–101% of Kpw), depending on the analyte. The increase in Kpw would have the effect of reducing by approximately half the calculated freely dissolved pore-water concentrations (Cfree). This demonstrates the importance of determining partition coefficients under conditions as they exist in the field.
Spatial correlation coefficient images for ultrasonic detection.
Cepel, Raina; Ho, K C; Rinker, Brett A; Palmer, Donald D; Lerch, Terrence P; Neal, Steven P
2007-09-01
In ultrasonics, image formation and detection are generally based on signal amplitude. In this paper, we introduce correlation coefficient images as a signal-amplitude independent approach for image formation. The correlation coefficients are calculated between A-scans digitized at adjacent measurement positions. In these images, defects are revealed as regions of high or low correlation relative to the background correlations associated with noise. Correlation coefficient and C-scan images are shown to demonstrate flat-bottom-hole detection in a stainless steel annular ring and crack detection in an aluminum aircraft structure.
U.S. Department of Health & Human Services — In general, total combined rates for traumatic brain injury (TBI)-related emergency department (ED) visits, hospitalizations and deaths have increased over the past...
Jee, Yon Ho; Shin, Aesun; Lee, Jong-Keun; Oh, Chang-Mo
2016-12-05
Background: This study aimed to examine trends in smoking-related cancer mortality rates and to investigate the effect birth cohort on smoking-related cancer mortality in Korean men. Methods: The number of smoking-related cancer deaths and corresponding population numbers were obtained from Statistics Korea for the period 1984-2013. Joinpoint regression analysis was used to detect changes in trends in age-standardized mortality rates. Birth-cohort specific mortality rates were illustrated by 5 year age groups. Results: The age-standardized mortality rates for oropharyngeal decreased from 2003 to 2013 (annual percent change (APC): -3.1 (95% CI, -4.6 to -1.6)) and lung cancers decreased from 2002 to 2013 (APC -2.4 (95% CI -2.7 to -2.2)). The mortality rates for esophageal declined from 1994 to 2002 (APC -2.5 (95% CI -4.1 to -0.8)) and from 2002 to 2013 (APC -5.2 (95% CI -5.7 to -4.7)) and laryngeal cancer declined from 1995 to 2013 (average annual percent change (AAPC): -3.3 (95% CI -4.7 to -1.8)). By the age group, the trends for the smoking-related cancer mortality except for oropharyngeal cancer have changed earlier to decrease in the younger age group. The birth-cohort specific mortality rates and age-period-cohort analysis consistently showed that all birth cohorts born after 1930 showed reduced mortality of smoking-related cancers. Conclusions: In Korean men, smoking-related cancer mortality rates have decreased. Our findings also indicate that current decreases in smoking-related cancer mortality rates have mainly been due to a decrease in the birth cohort effect, which suggest that decrease in smoking rates.
Regidor-Cerrillo Javier
2011-02-01
Full Text Available Abstract In this study, we examined the in vitro invasion and proliferation capacities of the Nc-Liv and ten Spanish Neospora caninum isolates (Nc-Spain 1 H - Nc-Spain 10. The invasion rate was determined as the number of tachyzoites that completed their internalisation into MARC-145 cells at 2, 4, and 6 h post-inoculation (pi. The proliferation rate was evaluated by determining the doubling time during the exponential proliferation period. Significant differences in the invasion rates of these isolates were detected at 2 and 4 h pi (P P = 0.0016, ANOVA test. Tachyzoite yield, which combines invasion and proliferation data, was also assessed and confirmed marked differences between the highly and less prolific isolates. Interestingly, a direct correlation between the invasion rates and tachyzoite yields, and the severity of the disease that was exhibited by infected pregnant mice in previous works could be established for the isolates in this study (Spearman's coefficient > 0.62, P
Heiner eLatus
2015-07-01
Full Text Available BACKGROUND: Pulmonary hypertension (PH is frequently associated with an increase in sympathetic tone. This may adversely affect cardiac autonomic control. Knowledge about the clinical impact of autonomic dysfunction in patients with PH is limited. We aimed to assess whether parameters of heart rate variability (HRV are related to disease severity in children with PH.METHODS: Parameters of HRV [SDNN = standard deviation of normal-to-normal intervals, and SDANN = standard deviation of mean values for normal-to-normal intervals over 5 min] were determined from Holter electrocardiograms of 17 patients with PH without active intracardial shunt (10 female, mean age 12.8 ±8.7 years. Patients were allocated to 2 groups according to their disease severity: patients with moderate PH (ratio of pulmonary to systemic arterial pressure (PAP/SAP ratio 0.75 (n=6. An additional group of 5 adolescents with Eisenmenger syndrome (PAP/SAP ratio 1.13±0.36 was included.RESULTS: Children with severe PH had significantly lower values of HRV [SDNN (73.8 ±21.1 ms vs. 164.9 ±38.1 ms, SDANN (62.2 ±19.0 ms vs. 139.5 ±33.3 ms] compared to patients with moderate PH (p=0.0001 for all. SDNN inversely correlated with ratio of PAP/SAP of PH patients without shunt (r=-0.82; p=0.0002. Eisenmenger patients showed no significant difference of HRV [SDNN 157.6 ±43.2 ms, SDANN 141.2 ±45.3 ms] compared to patients with moderate PH without shunt (p >0.05 for all.CONCLUSIONS: According to our results, children with severe PH may have alterations in HRV. Since HRV appears to be related to disease severity, it may therefore serve as an additional diagnostic marker of PH. Remarkably, although Eisenmenger patients have suprasystemic pulmonary arterial pressures, they seem to have preserved HRV, which might reflect a more favourable autonomic adaptation.
Wilson, Donald J; Takahashi, Ken; Sakuragi, Sonoko; Yoshino, Masako; Hoshuyama, Tsutomu; Imai, Teppei; Takala, Jukka
2007-01-01
The aim of this study was to assess the relationship between the ratification status of occupational safety and health (OSH)-related ILO conventions and reported occupational fatality rates of ILO member countries, while controlling for possible confounding factors. ILO member states were divided into 4 levels of income status, based on the gross national income per capita. Seventeen conventions designated as OSH-related were examined. Reported country occupational fatality rates were compared according to the ratification status of these 17 conventions and multiple regression analyses were conducted to assess the relationship between the fatality rates, ratification status, income level and length of ILO membership. Fatality rates were inversely and significantly related to income levels. In general, non-ratifying countries had higher work-related fatality rates than ratifying countries. A statistical model for identifying predictors of fatal injury rates showed that a larger number of conventions ratified was significantly associated with lower fatality rates. The fact that non-ratifying countries generally have higher fatality rates than ratifying ones supports the notion that all countries should promote ratification of ILO conventions aimed at improving OSH conditions.
Saeedian, Radka Ghorbani; Nagyova, Iveta; Klein, Daniel; Skorvanek, Matej; Rosenberger, Jaroslav; Gdovinova, Zuzana; Groothoff, Johan W.; van Dijk, Jitze
2014-01-01
Aims and objectives To explore whether self-rated health acts as a potential mediator in the association between functional status and health-related quality of life in Parkinson's disease. Background Older persons (as most patients with Parkinson's disease are) who reported poor self-rated health c
Eckardt, Robert C.; Byer, Robert L.; Masuda, Hisashi; Fan, Yuan Xuan
1990-01-01
Both absolute and relative nonlinear optical coefficients of six nonlinear materials measured by second-harmonic generation are discussed. A single-mode, injection-seeded, Q-switched Nd:YAG laser with spatially filtered output was used to generate the 1.064-micron fundamental radiation. The following results were obtained: d36(KDP) = 0.38 pm/V, d36(KD/asterisk/P) = 0.37 pm/V, (parallel)d22(BaB2O4)(parallel) = 2.2 pm/V, d31(LiIO3) = -4.1 pm/V, d31(5 percentMgO:MgO LiNbO3) = -4.7 pm/V, and d(eff)(KTP) = 3.2 pm/V. The accuracy of these measurements is estimated to be better than 10 percent.
Relation between heart rate recovery after exercise testing and body mass index.
Barbosa Lins, Tereza Cristina; Valente, Lucila Maria; Sobral Filho, Dário Celestino; Barbosa e Silva, Odwaldo
2015-01-01
Impaired heart rate (HR) recovery after exercise testing is considered a predictor of cardiovascular mortality as it reflects vagus nerve dysfunction. To assess the relationship between body mass index (BMI) and HR recovery after exercise. We analyzed the records of 2443 patients of both sexes, aged between 20 and 59 years, in sinus rhythm, not using negative chronotropic agents and with no myocardial ischemic response to exercise testing carried out at a specialist clinic, between 2005 and 2011. BMI was categorized as normal (18.5-30 kg/m(2)). The different BMI groups were compared in terms of HR recovery after exercise, which was calculated as the difference between maximum HR during exercise and in the first minute of recovery. Recovery was considered impaired when the difference was ≤12 bpm. Eighty-seven (3.6%) patients presented impaired recovery, which was three times more prevalent in the obese group and twice as prevalent in the overweight group compared with the normal group (p<0.001 and p=0.010, respectively). Obese patients presented higher basal HR and lower maximum HR, as well as reduced chronotropic reserve (p<0.001). In multivariate analysis, impaired HR recovery was associated with overweight (relative risk [RR]=1.8; p=0.035), obesity (RR=2; p=0.016), number of metabolic equivalents (RR=0.82; p<0.001) and resting HR (RR=1.05; p<0.001). The hazard ratio for hypertension was 2 (p=0.083, NS). Impaired HR recovery was associated with higher BMI, demonstrating that obese individuals present vagus nerve dysfunction. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.
Cahill, Niamh; Kemp, Andrew C.; Horton, Benjamin P.; Parnell, Andrew C.
2016-02-01
We present a Bayesian hierarchical model for reconstructing the continuous and dynamic evolution of relative sea-level (RSL) change with quantified uncertainty. The reconstruction is produced from biological (foraminifera) and geochemical (δ13C) sea-level indicators preserved in dated cores of salt-marsh sediment. Our model is comprised of three modules: (1) a new Bayesian transfer (B-TF) function for the calibration of biological indicators into tidal elevation, which is flexible enough to formally accommodate additional proxies; (2) an existing chronology developed using the Bchron age-depth model, and (3) an existing Errors-In-Variables integrated Gaussian process (EIV-IGP) model for estimating rates of sea-level change. Our approach is illustrated using a case study of Common Era sea-level variability from New Jersey, USA We develop a new B-TF using foraminifera, with and without the additional (δ13C) proxy and compare our results to those from a widely used weighted-averaging transfer function (WA-TF). The formal incorporation of a second proxy into the B-TF model results in smaller vertical uncertainties and improved accuracy for reconstructed RSL. The vertical uncertainty from the multi-proxy B-TF is ˜ 28 % smaller on average compared to the WA-TF. When evaluated against historic tide-gauge measurements, the multi-proxy B-TF most accurately reconstructs the RSL changes observed in the instrumental record (mean square error = 0.003 m2). The Bayesian hierarchical model provides a single, unifying framework for reconstructing and analyzing sea-level change through time. This approach is suitable for reconstructing other paleoenvironmental variables (e.g., temperature) using biological proxies.
Dai, Guang-Ming
2006-02-15
The set of Fourier series is discussed following some discussion of Zernike polynomials. Fourier transforms of Zernike polynomials are derived that allow for relating Fourier series expansion coefficients to Zernike polynomial expansion coefficients. With iterative Fourier reconstruction, Zernike representations of wavefront aberrations can easily be obtained from wavefront derivative measurements.
How is the rate of climatic-niche evolution related to climatic-niche breadth?
Fisher-Reid, M Caitlin; Kozak, Kenneth H; Wiens, John J
2012-12-01
The rate of climatic-niche evolution is important to many research areas in ecology, evolution, and conservation biology, including responses of species to global climate change, spread of invasive species, speciation, biogeography, and patterns of species richness. Previous studies have implied that clades with higher rates of climatic-niche evolution among species should have species with narrower niche breadths, but there is also evidence suggesting the opposite pattern. However, the relationships between rate and breadth have not been explicitly analyzed. Here, we examine the relationships between the rate of climatic-niche evolution and climatic-niche breadth using phylogenetic and climatic data for 250 species in the salamander family Plethodontidae, a group showing considerable variation in both rates of climatic-niche evolution and climatic-niche breadths. Contrary to some expectations, we find no general relationship between climatic-niche breadth and the rate of climatic-niche evolution. Climatic-niche breadths for some ecologically important climatic variables considered separately (temperature seasonality and annual precipitation) do show significant relationships with the rate of climatic-niche evolution, but rates are faster in clades in which species have broader (not narrower) niche breadths. In summary, our results show that narrower niche breadths are not necessarily associated with faster rates of niche evolution. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Structure/property relations of aluminum under varying rates and stress states
Tucker, Matthew T [Los Alamos National Laboratory; Horstemeyer, Mark F [MISSISSIPPI STATE UNIV; Whittington, Wilburn R [MISSISSIPPI STATE UNIV; Solanki, Kiran N [MISSISSIPPI STATE UNIV.
2010-11-19
In this work we analyze the plasticity, damage, and fracture characteristics of three different processed aluminum alloys (rolled 5083-H13, cast A356-T6, and extruded 6061-T6) under varying stress states (tension, compression, and torsion) and strain rates (0.001/, 1/s., and 1000/s). The stress state difference had more of a flow stress effect than the applied strain rates for those given in this study (0.001/sec up to 1000/sec). The stress state and strain rate also had a profound effect on the damage evolution of each aluminum alloy. Tension and torsional straining gave much greater damage nucleation rates than compression. Although the damage of all three alloys was found to be void nucleation dominated, the A356-T6 and 5083-H131 aluminum alloys incurred void damage via micron scale particles where the 6061-T6 aluminum alloy incurred void damage from two scales, micron-scale particles and nanoscale precipitates. Having two length scales of particles that participated in the damage evolution made the 6061-T6 incur a strain rate sensitive damage rate that was different than the other two aluminum alloys. Under tension, as the strain rate increased, the 6061-T6 aluminum alloy's void nucleation rate decreased, but the A356-T6 and 5083-H131 aluminum alloys void nucleation rate increased.
Thermal expansion coefficient of binary semiconductors
Kumar, V.; Sastry, B.S.R. [Indian School of Mines, Dhanbad (India). Dept. of Electronics and Instrumentation
2001-07-01
The linear thermal expansion coefficient of tetrahedrally coordinated A{sup II}B{sup VI} and A{sup III}B{sup V} semiconductors has been calculated using plasmon energy data. A simple relation between the bond length and plasmon energy has been derived. The calculated values of thermal expansion coefficient and bond length have been compared with the experimental values and the values reported by different workers. An excellent experiment has been obtained between them. (orig.)
Gebraegziabher, Habtamu Giday; Kjær, Katrine Heinsvig; Ottosen, Carl-Otto;
2015-01-01
Plants grown at high relative air humidity (RH) often show disturbed water relations due to less responsive stomata. The attenuation of stomatal responsiveness as a result of high RH during leaf expansion depends on the cultivar. We hypothesized that tolerant cultivars to high RH experience a lower...... a given cultivar, Tleaf was generally higher, (1.5-3.7°C) at high as compared to moderate RH. Following desiccation, leaf weight loss was differentially enhanced (8-66%) in high RH-grown plants, indicating a wide variation in high RH tolerance. High RH mainly decreased plant water loss during the light...
The relation between star formation rate and stellar mass of galaxies at z $\\sim$ 1-4
Katsianis, A; Wyithe, J S B
2015-01-01
The relation between the Star Formation Rate (SFR) and stellar mass (${\\rm M}_{\\star}$) of galaxies represents a fundamental constraint on galaxy formation. However, the observed amplitude of the star formation rate - stellar mass relation has not been successfully reproduced in simulations, indicating either that the halo accretion history and baryonic physics are poorly understood or that observations contain biases. In this paper, we examine the evolution of the SFR$-{\\rm M}_{\\star}$ relation of $z\\sim 1-4 $ galaxies and display the inconsistency between observed relations that are obtained using different techniques. We employ cosmological hydrodynamic simulations from various groups and compare these with a range of observations. The comparison suggests that using Spectral Energy Distributions (SEDs) to estimate star formation rates, dust corrections and stellar masses produces the most reliable SFR$-{\\rm M}_{\\star}$ relations. On the contrary, the combination of IR and UV luminosities (UV+IR) overpredic...
Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.
2008-01-01
The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…
Research on Mail Surveys: Response Rates and Methods in Relation to Population Group and Time.
Boser, Judith A.; Green, Kathy
The purpose of this review was to look for trends across time in response rates and variables studied for published mail surveys and to compare response rates and variables studied for different target populations. Studies were identified in databases in four fields: education, psychology, business and marketing, and sociology. A total of 225…
Relative Role of Gas Generation and Displacement Rates in Cavity Nucleation and Growth
Singh, Bachu Narain; Foreman, A. J E.
1984-01-01
Problems of helium diffusion and clustering during irradiation are analysed. Using the “homogeneous” nucleation theory , the effect of damage rate on cavity density is calculated for different gas generation to damage rate ratios. The influence of gas mobility on cavity nucleation has been evalua...
Converting Sabine absorption coefficients to random incidence absorption coefficients
Jeong, Cheol-Ho
2013-01-01
Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a sample and non-uniform intensity in the reverberation chambers under test. In this study, conversion methods from Sabine absorption...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...
Pawel, David [U.S. Environmental Protection Agency; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Nelson, Christopher [U.S. Environmental Protection Agency
2007-01-01
Federal Guidance Report No. 13 (FGR 13) provides risk coefficients for estimation of the risk of cancer due to low-level exposure to each of more than 800 radionuclides. Uncertainties in risk coefficients were quantified in FGR 13 for 33 cases (exposure to each of 11 radionuclides by each of three exposure pathways) on the basis of sensitivity analyses in which various combinations of plausible biokinetic, dosimetric, and radiation risk models were used to generate alternative risk coefficients. The present report updates the uncertainty analysis in FGR 13 for the cases of inhalation and ingestion of radionuclides and expands the analysis to all radionuclides addressed in that report. The analysis indicates that most risk coefficients for inhalation or ingestion of radionuclides are determined within a factor of 5 or less by current information. That is, application of alternate plausible biokinetic and dosimetric models and radiation risk models (based on the linear, no-threshold hypothesis with an adjustment for the dose and dose rate effectiveness factor) is unlikely to change these coefficients by more than a factor of 5. In this analysis the assessed uncertainty in the radiation risk model was found to be the main determinant of the uncertainty category for most risk coefficients, but conclusions concerning the relative contributions of risk and dose models to the total uncertainty in a risk coefficient may depend strongly on the method of assessing uncertainties in the risk model.
无
2000-01-01
The metabolic rate of Japanese sea bass, Lateolabrax japonicus (C & V), was estimated in laboratory at temperature 25.2±0.5℃. The fresh weight of the fish was 4.64-52.28 g (average of 17.81±0.33 g). The routine metabolism was related to body weight by the exponential equation: Rr=14.966W0.74 (r=0.934). The rate of feeding metabolism increased linearly with food consumption. Feeding metabolic rate was 1.8-2.4 times the routine metabolic rate.
Villesen, Christine; Hojsted, Jette; Kjeldsen, Lene Juel
2014-01-01
reviews conducted by a clinical pharmacist. Two hospital pharmacists, a general practitioner and two specialists in pain management from hospital care (the Panel) evaluated each DRP considering the potential clinical outcome for the patient. The DRPs were rated either nil, low, minor, moderate or highly...... clinically significant. Agreement was analysed using Kappa statistics. A Kappa value of 0.8 to 1.0 indicated nearly perfect agreement between ratings of the Panel members.Results The Panel rated 45 percent of the total 162 DRPs as of moderate clinical significance. However, the overall kappa score was 0...
Zhang, M. H. G.; Luhmann, J. G.; Nagy, A. F.; Spreiter, J. R.; Stahara, S. S.
1993-01-01
Oxygen ion production rates above the ionopauses of Venus and Mars are calculated for photoionization, charge exchange, and solar wind electron impact ionization processes. The latter two require the use of the Spreiter and Stahara (1980) gas dynamic model to estimate magnetosheath velocities, densities, and temperatures. The results indicate that impact ionization is the dominant mechanism for the production of O(+) ions at both Venus and Mars. This finding might explain both the high ion escape rates measured by Phobos 2 and the greater mass loading rate inferred for Venus from the bow shock positions.
A Systemic Review of Autologous Fat Grafting Survival Rate and Related Severe Complications
Nan-Ze Yu; Jiu-Zuo Huang; Hao Zhang; Yang Wang; Xiao-Jun Wang; Ru Zhao; Ming Bai
2015-01-01
Objective:Clinical application ofautologous fat grafting (AFG) is quickly expanding.Despite the widely acceptance,long-term survival rate (SR) of AFG remains a question not yet solved.Meanwhile,although rare,severe complications related to AFG including vision loss,stroke even death could be seen in the literature.Data Sources:A comprehensive research of PubMed database to June 2013 was performed according to guidelines of the American Society of Plastic Surgeons Fat Graft Task Force Assessment Methodology.Articles were screened using predetermined inclusion and exclusion criteria.Study Selection:Data collected included patient characteristics,surgical technique,donor site,recipient site,graft amount,and quantified measurement methods.Patient cohorts were pooled,and SR was calculated.All the severe complications were also summarized according to the different clinical characteristics.Results:Of 550 articles,16 clinical articles and 10 animal studies met the inclusion criteria and provided quantified measurement methods.Totally,596 patients were included.SR varied from 34％ to 82％ in breast and 30-83％ in the facial area.Nude mice were applied to investigate human fat grafting SR (38.3-52.5％ after 15 weeks).Rabbits were commonly used to study animal AFG SR (14.00-14.56％ after 1-year).Totally,21 severe complications were reported,including death (2),stroke (10),vision loss (11,8 of which accompanied with stroke),sepsis (3),multiple abscess (1) and giant fat necrotic cyst (2).Ten of these complications happened within 10 years.Conclusions:There is no unified measurement method to evaluate fat graft SR until now and no clinical evidence to show better SR according to different donor and recipient cite.Body mass index change between pre-and postoperation may be the bias factor in evaluating fat SR.Fat embolisms of the ophthalmic artery and the middle cerebral artery are the most severe complication of AFG and still lack of effective treatment.
Swart, de E.A.M.; Marcelis, L.F.M.; Voorrips, R.E.
2006-01-01
Differences in environmental conditions are known to influence plant growth and growth-related traits. The aim of this study was to identify the variation in relative growth rate (RGR), and its underlying physiological and morphological traits, in a group of ten wild and cultivated Capsicum accessio
Ter Steege, MW; Stulen, [No Value; Wiersema, PK; Posthumus, F; Vaalburg, W
1999-01-01
Regulation of nitrate influx and efflux in spinach (Spinacia oleracea L., cv. Subito), was studied in short-term label experiments with N-13- and N-15-nitrate. Nitrate fluxes were examined in relation to the N demand for growth, defined as relative growth rate (RGR) times plant N concentration. Plan
The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome
Xian, Hong; Liu, Weijian; Marshall, Cynthia; Chandiramani, Pooja; Bainter, Emily; Martin, III, Wade H
2016-01-01
PURPOSEArm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity...
Average Rate of Heat-Related Hospitalizations in 23 States, 2001-2010
U.S. Environmental Protection Agency — This map shows the 2001–2010 average rate of hospitalizations classified as “heat-related” by medical professionals in 23 states that participate in CDC’s...
We should be using nonlinear indices when relating heart-rate dynamics to cognition and mood
Young, Hayley; Benton, David
2015-01-01
Both heart rate (HR) and brain functioning involve the integrated output of a multitude of regulatory mechanisms, that are not quantified adequately by linear approximations such as means and standard deviations...
Callan, Mitchell J; Kim, Hyunji; Matthews, William J
2015-01-01
Lower subjective socioeconomic status (SSS) and higher personal relative deprivation (PRD) relate to poorer health. Both constructs concern people's perceived relative social position, but they differ in their emphasis on the reference groups people use to determine their comparative disadvantage (national population vs. similar others) and the importance of resentment that may arise from such adverse comparisons. We investigated the relative utility of SSS and PRD as predictors of self-rated physical and mental health (e.g., self-rated health, stress, health complaints). Across six studies, self-rated physical and mental health were on the whole better predicted by measures of PRD than by SSS while controlling for objective socioeconomic status (SES), with SSS rarely contributing unique variance over and above PRD and SES. Studies 4-6 discount the possibility that the superiority of PRD over SSS in predicting health is due to psychometric differences (e.g., reliability) or response biases between the measures.
Term structure of interest rate, relative factors and exchange rate prediction%利率期限结构、相对因子与汇率预测
李艳; 吴亮
2016-01-01
由于利率期限结构中包含未来经济运行的信息，利用2006年4月到2014年12月中美两国利率期限结构的月度数据，通过动态Nelson-Siegel模型抽取两国利率期限结构的相对水平，斜率和凸度三因子，基于三个相对因子检验其对人民币/美元汇率的预测能力。实证研究表明：（1）相对因子模型对汇率在1到12月期具有可预测性，相对水平因子或相对斜率因子增加1%分别导致人民币升值1%和2%而相对凸度因子增加1%会导致人民币贬值1%；（2）基于CW检验统计量的滚动窗预测表明：在所考虑的各个滚动窗下，相对因子模型预测能力优于随机游走和非抛补利率平价模型。%Since the term structure of interest rates embodies information about future economic activity, this paper uses dy-namic Nelson-Siegel model to extract relative level, slope and curvature based on monthly data of interest rate of term structure of China and United States from April in 2006 to December in 2014 and analyses forecasting ability of relative factors on Ren-minbi/Dollar exchange rate. The empirical study shows that (1) Relative factors model can predict exchange rate changes 1 to 12 months ahead, and 1 percentage point increase in relative level or slope predicts 1%and 2%annualized appreciation of the Ren-minbi respectively, 1 percentage point increase in relative curvature predicts 1% annualized depreciation of the Renminbi; (2) Rolling window forecasting based on Clark-West statistics shows that relative factors model outperforms random walk and un-covered interest parity model.
Lilly, Simon J.; Carollo, C. Marcella; Pipino, Antonio; Peng Yingjie [Institute for Astronomy, Department of Physics, ETH Zurich, CH-8093 Zurich (Switzerland); Renzini, Alvio [Department of Physics and Astronomy Galileo Galilei, Universita degli Studi di Padova, via Marzolo 8, I-35131 Padova (Italy)
2013-08-01
A very simple physical model of galaxies is one in which the formation of stars is instantaneously regulated by the mass of gas in a reservoir with mass loss scaling with the star-formation rate (SFR). This model links together three different aspects of the evolving galaxy population: (1) the cosmic time evolution of the specific star-formation rate (sSFR) relative to the growth of halos, (2) the gas-phase metallicities across the galaxy population and over cosmic time, and (3) the ratio of the stellar to dark matter mass of halos. The gas regulator is defined by the gas consumption timescale ({epsilon}{sup -1}) and the mass loading {lambda} of the wind outflow {lambda}{center_dot}SFR. The simplest regulator, in which {epsilon} and {lambda} are constant, sets the sSFR equal to exactly the specific accretion rate of the galaxy; more realistic situations lead to an sSFR that is perturbed from this precise relation. Because the gas consumption timescale is shorter than the timescale on which the system evolves, the metallicity Z is set primarily by the instantaneous operation of the regulator system rather than by the past history of the system. The metallicity of the gas reservoir depends on {epsilon}, {lambda}, and sSFR, and the regulator system therefore naturally produces a Z(m{sub star}, SFR) relation if {epsilon} and {lambda} depend on the stellar mass m{sub star}. Furthermore, this relation will be the same at all epochs unless the parameters {epsilon} and {lambda} themselves change with time. A so-called fundamental metallicity relation is naturally produced by these conditions. The overall mass-metallicity relation Z(m{sub star}) directly provides the fraction f{sub star}(m{sub star}) of incoming baryons that are being transformed into stars. The observed Z(m{sub star}) relation of Sloan Digital Sky Survey (SDSS) galaxies implies a strong dependence of stellar mass on halo mass that reconciles the different faint-end slopes of the stellar and halo mass
Genome-wide association analysis identifies multiple loci related to resting heart rate
Eijgelsheim, Mark; Newton-Cheh, Christopher; Sotoodehnia, Nona; de Bakker, Paul I.W.; Müller, Martina; Morrison, Alanna C.; Smith, Albert V.; Isaacs, Aaron; Sanna, Serena; Dörr, Marcus; Navarro, Pau; Fuchsberger, Christian; Nolte, Ilja M.; de Geus, Eco J.C.; Estrada, Karol; Hwang, Shih-Jen; Bis, Joshua C.; Rückert, Ina-Maria; Alonso, Alvaro; Launer, Lenore J.; Hottenga, Jouke Jan; Rivadeneira, Fernando; Noseworthy, Peter A.; Rice, Kenneth M.; Perz, Siegfried; Arking, Dan E.; Spector, Tim D.; Kors, Jan A.; Aulchenko, Yurii S.; Tarasov, Kirill V.; Homuth, Georg; Wild, Sarah H.; Marroni, Fabio; Gieger, Christian; Licht, Carmilla M.; Prineas, Ronald J.; Hofman, Albert; Rotter, Jerome I.; Hicks, Andrew A.; Ernst, Florian; Najjar, Samer S.; Wright, Alan F.; Peters, Annette; Fox, Ervin R.; Oostra, Ben A.; Kroemer, Heyo K.; Couper, David; Völzke, Henry; Campbell, Harry; Meitinger, Thomas; Uda, Manuela; Witteman, Jacqueline C.M.; Psaty, Bruce M.; Wichmann, H-Erich; Harris, Tamara B.; Kääb, Stefan; Siscovick, David S.; Jamshidi, Yalda; Uitterlinden, André G.; Folsom, Aaron R.; Larson, Martin G.; Wilson, James F.; Penninx, Brenda W.; Snieder, Harold; Pramstaller, Peter P.; van Duijn, Cornelia M.; Lakatta, Edward G.; Felix, Stephan B.; Gudnason, Vilmundur; Pfeufer, Arne; Heckbert, Susan R.; Stricker, Bruno H.Ch.; Boerwinkle, Eric; O'Donnell, Christopher J.
2010-01-01
Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that influence pathologic heart rate states, modulate heart rate through cardiac structure and function or by improving our understanding of the physiology of heart rate regulation. To identify common genetic variants associated with heart rate, we performed a meta-analysis of 15 genome-wide association studies (GWAS), including 38 991 subjects of European ancestry, estimating the association between age-, sex- and body mass-adjusted RR interval (inverse heart rate) and ∼2.5 million markers. Results with P < 5 × 10−8 were considered genome-wide significant. We constructed regression models with multiple markers to assess whether results at less stringent thresholds were likely to be truly associated with RR interval. We identified six novel associations with resting heart rate at six loci: 6q22 near GJA1; 14q12 near MYH7; 12p12 near SOX5, c12orf67, BCAT1, LRMP and CASC1; 6q22 near SLC35F1, PLN and c6orf204; 7q22 near SLC12A9 and UfSp1; and 11q12 near FADS1. Associations at 6q22 400 kb away from GJA1, at 14q12 MYH6 and at 1q32 near CD34 identified in previously published GWAS were confirmed. In aggregate, these variants explain ∼0.7% of RR interval variance. A multivariant regression model including 20 variants with P < 10−5 increased the explained variance to 1.6%, suggesting that some loci falling short of genome-wide significance are likely truly associated. Future research is warranted to elucidate underlying mechanisms that may impact clinical care. PMID:20639392
Coupling coefficients for coupled-cavity lasers
Lang, R.J.; Yariv, A.
1987-03-01
The authors derive simple, analytic formulas for the field coupling coefficients in a two-section coupled-cavity laser using a local field rate equation treatment. They show that there is a correction to the heuristic formulas based on power flow calculated by Marcuse; the correction is in agreement with numerical calculations from a coupled-mode approach.
D Dominic Amalraj
2005-12-01
Full Text Available Food utilization by the larvae of Toxorhynchites splendens (Wiedemann was studied in the laboratory by offering larvae of Aedes aegypti Linnaeus, Anopheles stephensi (Liston, and Culex quinquefasciatus (Say. Quantitative analyses of data indicated that immature development was significantly faster with increase in food availability. The regression analysis showed that the degrees of the relationship between immature duration (Id and food availability were higher when offered early instars of prey (first and second instars than late instars. Consumption rate (Cr of the predator increased with increase in food availability and this relationship was highly significant when larvae of An. stephensi were offered as food. Consumption rate to food level decreased with increase in the age class of the prey. There was a significant negative correlation between Id and Cr. This aspect helps to increase population turnover of T. splendens in a shorter period when the prey is abundant. Conversely, the predator compensated the loss in daily food intake at low food level by extending Id thereby attains the minimum threshold pupal weight for adult emergence. There was an increase in the relative growth rate (RGR of the predator when An. stephensi was offered as prey and this was related to the high protein content of the prey per body weight. There was a positive correlation between Cr and RGR. This adaptive life characteristic strategy of this predator is useful for mass-rearing for large scale field release programmes in the control of container breeding mosquitoes is discussed.
Yetkin Yıldırım, Gonca; Orta Korkut, Ahu; Köroğlu, Nadiye; Susan Türkgeldi, Lale
2017-01-01
Background: Tubal factor infertility is one of the main causes of female infertility. Although its sensitivity is low, hysterosalpingography (HSG) is remains the first-line method for evaluating tubal patency. Aims: To compare pregnancy rates in patients with HSG proven proximal or distal unilateral tubal occlusion, and unexplained infertility undergoing both controlled ovarian stimulation (COS) and intrauterine insemination (IUI). Study Design: Case control study. Methods: In total, 237 patients undergoing ovulation induction (OI) with gonadotropins and IUI were divided into two groups and evaluated. Study group consisted 59 patients with HSG proven unilateral tubal pathology, and 178 patients with unexplained infertility taken as control subjects. Cumulative pregnancy rate was the primary endpoint. Results: Cumulative pregnancy rates after three cycles of OI and IUI were 15.25% in study group and 20.79% in control group. Pregnancy rates between two groups were not statistically significant. Although, pregnancy rates in patients with proximal tubal occlusion (21.8%) were higher than in those with distal tubal occlusion (7.4%), the difference was not statistically significant. Conclusion: Our study data shows that, regardless of the HCG proven occlusion area, COS and IUI might be a preferred treatment modality in patient with unilateral tubal occlusion. PMID:28251025
Primordial star formation: relative impact of H2 three-body rates and initial conditions
Bovino, S; Grassi, T
2013-01-01
Population III stars are the first stars in the Universe to form at z=20-30 out of a pure hydrogen and helium gas in minihalos of 10^5-10^6 M$_\\odot$ . Cooling and fragmentation is thus regulated via molecular hydrogen. At densities above 10^8 cm$^{-3}$, the three-body H2 formation rates are particularly important for making the gas fully molecular. These rates were considered to be uncertain by at least a few orders of magnitude. We explore the impact of new accurate three-body H2 formation rates derived by Forrey (2013) for three different minihalos, and compare to the results obtained with three-body rates employed in previous studies. The calculations are performed with the cosmological hydrodynamics code ENZO (release 2.2) coupled with the chemistry package KROME (including a network for primordial chemistry), which was previously shown to be accurate in high resolution simulations. While the new rates can shift the point where the gas becomes fully molecular, leading to a different thermal evolution, th...
Kristin M. Rager
2006-01-01
Full Text Available High discontinuation rates for depot medroxyprogesterone acetate (DMPA in adolescents may contribute to the number of unintended pregnancies. Many cite vaginal bleeding as a reason for discontinuing DMPA use. In this study, we attempted to determine if treating DMPA-associated vaginal bleeding with monophasic oral contraceptive pills (OCP raised continuation rates. A total of 131 patients who reported vaginal bleeding while on DMPA were included in this study and 83 were treated with monophasic OCP. Of those who received OCP, 38.7% reported that vaginal bleeding stopped completely, 51.8% reported that vaginal bleeding stopped temporarily, and 6.0% reported no change. Overall, 94% of enrolled patients who received OCP as a treatment for DMPA-associated vaginal bleeding continued DMPA use. Our findings indicate that vaginal bleeding due to DMPA can be successfully treated, leading to improvement in continuation rates.
Coles, Chantal A; Wadeson, Jenny; Leyton, Carolina P; Siddell, Jason P; Greenwood, Paul L; White, Jason D; McDonagh, Matthew B
2015-01-01
Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM) of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5-20 hours in culture) in vitro (P cattle (P cattle (P cattle.
Relation between the location of elements in the periodic table and various organ-uptake rates.
Ando, A; Ando, I; Hiraki, T; Hisada, K
1989-01-01
Fifty four elements and 65 radioactive compounds were examined to determine the organ uptake rates for rats 3, 24 and 48 h after i.v. injection of these compounds. They were prepared as carrier free nuclides, or containing a small amount of stable nuclide. Generally speaking, behaviors of K, Rb, Cs and Tl in all the organs were very similar to one another, but they differed from that of Na. Bivalent hard acids were avidly taken up into bone; therefore, uptake rates in soft tissues were very small. Hard acids of tri-, quadri- and pentavalence which were taken up into the soft tissue organs decreased more slowly from these organs than other ions. Soft acids such as Hg2+ were bound very firmly to the component in the kidney. Anions (with few exceptions), GeCl4 and SbCl3 were rapidly excreted in urine, so that the uptake rates in organs were low.
Ratings of journals for the dissemination of pharmacy-related social and administrative science.
Bunniran, Suvapun; Holmes, Erin R; Lobb, William B; McCaffrey, David J
2008-06-01
It has been over a decade since a journal quality rating study has been conducted in the social and administrative sciences (SAdS). This study sought to reevaluate perceptions of journal quality. To develop a list of journals that are suitable publication venues for SAdS scholars and compare the quality of these journals as rated by school of pharmacy deans, SAdS department/division chairs, and SAdS faculty. A list of journals was assembled and presented to a Delphi panel of 15 SAdS scholars. Using a modified Delphi technique, the panel refined the list by judging the suitability of each journal as a publication venue for scholars. This list was used in a survey administered via the Internet. Journal quality was rated on a 7-point Likert-type scale with the option of indicating unfamiliarity with each journal. Differences in quality ratings between faculty, chairs, and deans were explored. Adjusted rating scores were calculated based on familiarity with journals. Ratings from the current study were compared to previous studies. One hundred and twelve journals emerged from the modified Delphi technique. Kruskal-Wallis analysis of variance found no significant difference in perceived journal quality across all journals evaluated by the 3 groups (KW=3.91). Groups did differ in their familiarity (KW=11.71, Pjournals and deans being the least familiar. Journal rankings were highly correlated with journal rankings from previously published studies. Results of this study have implications for scholars choosing publication venues and those who make decisions contingent on scholars' publication records. These differences may represent a positive or negative bias that affects hiring as well as tenure and promotion decisions. This study provides guidance for decisions reliant on publication records, but should not be used exclusively as such an indicator.
The influence of relatives on the efficiency and error rate of familial searching.
Rori V Rohlfs
Full Text Available We investigate the consequences of adopting the criteria used by the state of California, as described by Myers et al. (2011, for conducting familial searches. We carried out a simulation study of randomly generated profiles of related and unrelated individuals with 13-locus CODIS genotypes and YFiler® Y-chromosome haplotypes, on which the Myers protocol for relative identification was carried out. For Y-chromosome sharing first degree relatives, the Myers protocol has a high probability (80~99% of identifying their relationship. For unrelated individuals, there is a low probability that an unrelated person in the database will be identified as a first-degree relative. For more distant Y-haplotype sharing relatives (half-siblings, first cousins, half-first cousins or second cousins there is a substantial probability that the more distant relative will be incorrectly identified as a first-degree relative. For example, there is a 3~18% probability that a first cousin will be identified as a full sibling, with the probability depending on the population background. Although the California familial search policy is likely to identify a first degree relative if his profile is in the database, and it poses little risk of falsely identifying an unrelated individual in a database as a first-degree relative, there is a substantial risk of falsely identifying a more distant Y-haplotype sharing relative in the database as a first-degree relative, with the consequence that their immediate family may become the target for further investigation. This risk falls disproportionately on those ethnic groups that are currently overrepresented in state and federal databases.
The Influence of Relatives on the Efficiency and Error Rate of Familial Searching
Rohlfs, Rori V.; Murphy, Erin; Song, Yun S.; Slatkin, Montgomery
2013-01-01
We investigate the consequences of adopting the criteria used by the state of California, as described by Myers et al. (2011), for conducting familial searches. We carried out a simulation study of randomly generated profiles of related and unrelated individuals with 13-locus CODIS genotypes and YFiler® Y-chromosome haplotypes, on which the Myers protocol for relative identification was carried out. For Y-chromosome sharing first degree relatives, the Myers protocol has a high probability () of identifying their relationship. For unrelated individuals, there is a low probability that an unrelated person in the database will be identified as a first-degree relative. For more distant Y-haplotype sharing relatives (half-siblings, first cousins, half-first cousins or second cousins) there is a substantial probability that the more distant relative will be incorrectly identified as a first-degree relative. For example, there is a probability that a first cousin will be identified as a full sibling, with the probability depending on the population background. Although the California familial search policy is likely to identify a first degree relative if his profile is in the database, and it poses little risk of falsely identifying an unrelated individual in a database as a first-degree relative, there is a substantial risk of falsely identifying a more distant Y-haplotype sharing relative in the database as a first-degree relative, with the consequence that their immediate family may become the target for further investigation. This risk falls disproportionately on those ethnic groups that are currently overrepresented in state and federal databases. PMID:23967076
Negative Temperature Coefficient in Chemical Reactions
Leenson, I. A.; Sergeev, Gleb B.
1984-05-01
A systematic analysis of reactions whose rate decreases with increase of temperature is presented. The possibility of a negative temperature coefficient in the elementary reactions is examined from the standpoint of the transition state theory and of collision theory. The mechanisms of complex reactions in which the temperature dependence of the rate is anomalous are discussed, and possible reasons for the anomaly are examined. The bibliography contains 175 references.
Modelling water evaporation during frying with an evaporation dependent heat transfer coefficient
Koerten, van K.N.; Somsen, D.; Boom, R.M.; Schutyser, M.A.I.
2017-01-01
In this study a cylindrical crust-core frying model was developed including an evaporation rate dependent heat transfer coefficient. For this, we applied a Nusselt relation for cylindrical bodies and view the release of vapour bubbles during the frying process as a reversed fluidised bed. The cha
Modelling water evaporation during frying with an evaporation dependent heat transfer coefficient
Koerten, van K.N.; Somsen, D.; Boom, R.M.; Schutyser, M.A.I.
2017-01-01
In this study a cylindrical crust-core frying model was developed including an evaporation rate dependent heat transfer coefficient. For this, we applied a Nusselt relation for cylindrical bodies and view the release of vapour bubbles during the frying process as a reversed fluidised bed. The cha
Linear rate-equilibrium relations arising from ion channel-bilayer energetic coupling
Greisen, Per Junior; Lum, Kevin; Ashrafuzzaman, Md;
2011-01-01
and its position on a spatial coordinate. It turns out that the linear RE relation for the gramicidin monomer-dimer reaction can be understood, and the quantitative relation between changes in activation energy and equilibrium energy can be interpreted, by considering the effects of amphiphiles...
Accident rates related to rural road geometry elements and daily traffic
Skinner, DG
1994-02-01
Full Text Available The available data bases for accidents, road geometry (photolog output) and traffic counts were combined and the accident rates determined for two lane, four lane and six lane road categories as well as for 22 geometric element categories...
The relation between surface star formation rate density and spiral arms in NGC 5236 (M83)
Silva-Villa, Esteban
2011-01-01
For a long time the consensus has been that star formation rates are higher in the interior of spiral arms in galaxies, compared to inter-arm regions. However, recent studies have found that the star formation inside the arms is not more efficient than elsewhere in the galaxy. Previous studies have based their conclusion mainly on integrated light. We use resolved stellar populations to investigate the star formation rates throughout the nearby spiral galaxy NGC 5236. We aim to investigate how the star formation rate varies in the spiral arms compared to the inter-arm regions, using optical space-based observations of NGC 5236. Using ground-based H\\alpha images we traced regions of recent star formation, and reconstructed the arms of the galaxy. Using HST/ACS images we estimate star formation histories by means of the synthetic CMD method. Arms based on H\\alpha images showed to follow the regions where stellar crowding is higher. Star formation rates for individual arms over the fields covered were estimated ...
Genome-wide association analysis identifies multiple loci related to resting heart rate
M. Eijgelsheim (Mark); C. Newton-Cheh (Christopher); N. Sotoodehnia (Nona); P.I.W. de Bakker (Paul); M. Müller (Martina); A.C. Morrison (Alanna); A.V. Smith (Albert Vernon); A.J. Isaacs (Aaron); S. Sanna (Serena); M. Dörr (Marcus); P. Navarro (Pau); C. Fuchsberger (Christian); I.M. Nolte (Ilja); E.J.C. de Geus (Eco); K. Estrada Gil (Karol); S.J. Hwang; J.C. Bis (Joshua); I.M. Rückert; A. Alonso (Alvaro); L.J. Launer (Lenore); J.J. Hottenga (Jouke Jan); F. Rivadeneira Ramirez (Fernando); P.A. Noseworthy (Peter); K. Rice (Kenneth); S. Perz (Siegfried); D.E. Arking (Dan); T.D. Spector (Tim); J.A. Kors (Jan); Y.S. Aulchenko (Yurii); K.V. Tarasov (Kirill); G. Homuth (Georg); S.H. Wild (Sarah); F. Marroni (Fabio); C. Gieger (Christian); C.M. Licht (Carmilla); R.J. Prineas (Ronald); A. Hofman (Albert); J.I. Rotter (Jerome); A.A. Hicks (Andrew); F.D.J. Ernst (Florian); S.S. Najjar (Samer); A.F. Wright (Alan); A. Peters (Annette); E.R. Fox (Ervin); B.A. Oostra (Ben); H.K. Kroemer (Heyo); D.J. Couper (David); H. Völzke (Henry); H. Campbell (Harry); T. Meitinger (Thomas); M. Uda (Manuela); J.C.M. Witteman (Jacqueline); B.M. Psaty (Bruce); H.E. Wichmann (Heinz Erich); T.B. Harris (Tamara); S. Kääb (Stefan); D.S. Siscovick (David); Y. Jamshidi (Yalda); A.G. Uitterlinden (André); A.R. Folsom (Aaron); M.G. Larson (Martin); J.F. Wilson (James); B.W.J.H. Penninx (Brenda); H. Snieder (Harold); P.P. Pramstaller (Peter Paul); P. Tikka-Kleemola (Päivi); E. Lakatta (Edward); S.B. Felix (Stephan); V. Gudnason (Vilmundur); A. Pfeufer (Arne); S.R. Heckbert (Susan); B.H.Ch. Stricker (Bruno); E.A. Boerwinkle (Eric); C.J. O'Donnell (Christopher)
2010-01-01
textabstractHigher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel
Genome-wide association analysis identifies multiple loci related to resting heart rate
Eijgelsheim, Mark; Newton-Cheh, Christopher; Sotoodehnia, Nona; de Bakker, Paul I. W.; Mueller, Martina; Morrison, Alanna C.; Smith, Albert V.; Isaacs, Aaron; Sanna, Serena; Doerr, Marcus; Navarro, Pau; Fuchsberger, Christian; Nolte, Ilja M.; de Geus, Eco J. C.; Estrada, Karol; Hwang, Shih-Jen; Bis, Joshua C.; Rueckert, Ina-Maria; Alonso, Alvaro; Launer, Lenore J.; Hottenga, Jouke Jan; Rivadeneira, Fernando; Noseworthy, Peter A.; Rice, Kenneth M.; Perz, Siegfried; Arking, Dan E.; Spector, Tim D.; Kors, Jan A.; Aulchenko, Yurii S.; Tarasov, Kirill V.; Homuth, Georg; Wild, Sarah H.; Marroni, Fabio; Gieger, Christian; Licht, Carmilla M.; Prineas, Ronald J.; Hofman, Albert; Rotter, Jerome I.; Hicks, Andrew A.; Ernst, Florian; Najjar, Samer S.; Wright, Alan F.; Peters, Annette; Fox, Ervin R.; Oostra, Ben A.; Kroemer, Heyo K.; Couper, David; Voelzke, Henry; Campbell, Harry; Meitinger, Thomas; Uda, Manuela; Witteman, Jacqueline C. M.; Psaty, Bruce M.; Wichmann, H-Erich; Harris, Tamara B.; Kaeaeb, Stefan; Siscovick, David S.; Jamshidi, Yalda; Uitterlinden, Andre G.; Folsom, Aaron R.; Larson, Martin G.; Wilson, James F.; Penninx, Brenda W.; Snieder, Harold; Pramstaller, Peter P.; van Duijn, Cornelia M.; Lakatta, Edward G.; Felix, Stephan B.; Gudnason, Vilmundur; Pfeufer, Arne; Heckbert, Susan R.; Stricker, Bruno H. Ch.; Boerwinkle, Eric; O'Donnell, Christopher J.
2010-01-01
Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that
Relative User Ratings of MMPI-2 Computer-Based Test Interpretations
Williams, John E.; Weed, Nathan C.
2004-01-01
There are eight commercially available computer-based test interpretations (CBTIs) for the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), of which few have been empirically evaluated. Prospective users of these programs have little scientific data to guide choice of a program. This study compared ratings of these eight CBTIs. Test users…
Spangenberg, S.; Baarts, C.; Dyreborg, J.;
2002-01-01
of injury risk factors at group and individual level for Danish and Swedish workers. LTI-rates and injury risk factors were compared for Danish and Swedish workers during the construction of the combined rail and road link across the 16-km wide sound, Oresund, between Denmark and Sweden. The comparison...
Heart rate variability in relation to stress in the Asian elephant (Elephas maximus)
Vézina-Audette, Raphaël; Herry, Christophe; Burns, Patrick; Frasch, Martin; Chave, Emmanuelle; Theoret, Christine
2016-01-01
This study describes a safe, reliable, and accessible means to measure heart rate (HR) and HR variability (HRV) and evaluates the use of HRV as a physiological correlate of stress in the Asian elephant. A probabilistic model indicates that HRV measurements may adequately distinguish between stressed and non-stressed elephants. PMID:26933266
Rusina, T.P.; Smedes, F.; Koblizkova, M.; Klanova, J.
2010-01-01
Sampling rates (R-s) for silicone rubber (SR) passive samplers were measured under two different hydrodynamic conditions. Concentrations were maintained in the aqueous phase by continuous equilibration with SR sheets of a large total surface area which had been spiked with polycyclic aromatic hydroc
Møller, S.; Sternberg, Claus; Poulsen, L. K.
1995-01-01
A fast routine method for estimating bacterial cell growth rates by using the metachromatic dye acridine orange is described. The method allows simultaneous estimates of cellular RNA and DNA contents of single cells. Acridine orange staining can be used as a nonspecific supplement to quantitative...
Fogarty, Gerard J.; Davies, Janet E.; MacCann, Carolyn; Roberts, Richard D.
2014-01-01
Background: Parents consult with schools on how to help their children succeed, but schools rarely consult with parents, even though most parents have considerable expertise concerning their children's thoughts, feelings, and abilities. Aims: This study compares the prediction of academic achievement from self- and parent-ratings of feelings…
Chuang, Chern; Knoester, Jasper; Cao, Jianshu
2014-01-01
We theoretically study the distance, chain length, and temperature dependence of the electronic couplings as well as the excitonic energy transfer rates between one-dimensional (1D) chromophore aggregates. In addition to the well-known geometry dependent factor that leads to the deviation from Forst
Brain atrophy rates in first degree relatives at risk for Alzheimer's.
Lampert, Erika J; Roy Choudhury, Kingshuk; Hostage, Christopher A; Rathakrishnan, Bharath; Weiner, Michael; Petrella, Jeffrey R; Doraiswamy, P Murali
2014-01-01
A positive family history (FH) raises the risk for late-onset Alzheimer's disease though, other than the known risk conferred by apolipoprotein ε4 (ApoE4), much of the genetic variance remains unexplained. We examined the effect of family history on longitudinal regional brain atrophy rates in 184 subjects (42% FH+, mean age 79.9) with mild cognitive impairment (MCI) enrolled in a national biomarker study. An automated image analysis method was applied to T1-weighted MR images to measure atrophy rates for 20 cortical and subcortical regions. Mixed-effects linear regression models incorporating repeated-measures to control for within-subject variation over multiple time points tested the effect of FH over a follow-up of up to 48 months. Most of the 20 regions showed significant atrophy over time. Adjusting for age and gender, subjects with a positive FH had greater atrophy of the amygdala (p atrophy rates was numerically greater in ε3 homozygotes than in E4 carriers, but this difference was not significant. FH+ subjects had numerically greater 4-year cognitive decline and conversion rates than FH- subjects but the difference was not statistically significant after adjusting for ApoE and other variables. We conclude that a positive family history of AD may influence cortical and temporal lobe atrophy in subjects with mild cognitive impairment, but it does not have a significant additional effect beyond the known effect of the E4 genotype.
Factor Structure of the Rorschach Prognostic Rating Scale and Its Relation to Therapeutic Outcome
Auerbach, Stephen M.; Edinger, Jack D.
1976-01-01
This study evaluated the factor structure of the Rorschach Prognostic Rating Scale (RPRS) in order to: (a) test the assumption that the RPRS represents a unitary response system and (b) determine the efficacy of employing population specific factor scores as predictors of therapy outcome. (Author/NG)
Energy expenditure in relation to flight speed: whay is the power of mass loss rate estimates
Kvist, A.; Klaassen, M.R.J.; Lindström, A.
1998-01-01
The relationship between mass loss rate and chemical power in Eying birds is analysed with regard to water and heat balance. Two models are presented: the first model is applicable to situations where heat loads are moderate, i.e. when heat balance can be achieved by regulating non-evaporative heat
Genome-wide association analysis identifies multiple loci related to resting heart rate
Eijgelsheim, Mark; Newton-Cheh, Christopher; Sotoodehnia, Nona; de Bakker, Paul I. W.; Mueller, Martina; Morrison, Alanna C.; Smith, Albert V.; Isaacs, Aaron; Sanna, Serena; Doerr, Marcus; Navarro, Pau; Fuchsberger, Christian; Nolte, Ilja M.; de Geus, Eco J. C.; Estrada, Karol; Hwang, Shih-Jen; Bis, Joshua C.; Rueckert, Ina-Maria; Alonso, Alvaro; Launer, Lenore J.; Hottenga, Jouke Jan; Rivadeneira, Fernando; Noseworthy, Peter A.; Rice, Kenneth M.; Perz, Siegfried; Arking, Dan E.; Spector, Tim D.; Kors, Jan A.; Aulchenko, Yurii S.; Tarasov, Kirill V.; Homuth, Georg; Wild, Sarah H.; Marroni, Fabio; Gieger, Christian; Licht, Carmilla M.; Prineas, Ronald J.; Hofman, Albert; Rotter, Jerome I.; Hicks, Andrew A.; Ernst, Florian; Najjar, Samer S.; Wright, Alan F.; Peters, Annette; Fox, Ervin R.; Oostra, Ben A.; Kroemer, Heyo K.; Couper, David; Voelzke, Henry; Campbell, Harry; Meitinger, Thomas; Uda, Manuela; Witteman, Jacqueline C. M.; Psaty, Bruce M.; Wichmann, H-Erich; Harris, Tamara B.; Kaeaeb, Stefan; Siscovick, David S.; Jamshidi, Yalda; Uitterlinden, Andre G.; Folsom, Aaron R.; Larson, Martin G.; Wilson, James F.; Penninx, Brenda W.; Snieder, Harold; Pramstaller, Peter P.; van Duijn, Cornelia M.; Lakatta, Edward G.; Felix, Stephan B.; Gudnason, Vilmundur; Pfeufer, Arne; Heckbert, Susan R.; Stricker, Bruno H. Ch.; Boerwinkle, Eric; O'Donnell, Christopher J.
2010-01-01
Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that i
Genome-wide association analysis identifies multiple loci related to resting heart rate
M. Eijgelsheim (Mark); C. Newton-Cheh (Christopher); N. Sotoodehnia (Nona); P.I.W. de Bakker (Paul); M. Müller (Martina); A.C. Morrison (Alanna); A.V. Smith (Albert Vernon); A.J. Isaacs (Aaron); S. Sanna (Serena); M. Dörr (Marcus); P. Navarro (Pau); C. Fuchsberger (Christian); I.M. Nolte (Ilja); E.J.C. de Geus (Eco); K. Estrada Gil (Karol); S.J. Hwang; J.C. Bis (Joshua); I.M. Rückert; A. Alonso (Alvaro); L.J. Launer (Lenore); J.J. Hottenga (Jouke Jan); F. Rivadeneira Ramirez (Fernando); P.A. Noseworthy (Peter); K. Rice (Kenneth); S. Perz (Siegfried); D.E. Arking (Dan); T.D. Spector (Tim); J.A. Kors (Jan); Y.S. Aulchenko (Yurii); K.V. Tarasov (Kirill); G. Homuth (Georg); S.H. Wild (Sarah); F. Marroni (Fabio); C. Gieger (Christian); C.M. Licht (Carmilla); R.J. Prineas (Ronald); A. Hofman (Albert); J.I. Rotter (Jerome); A.A. Hicks (Andrew); F.D.J. Ernst (Florian); S.S. Najjar (Samer); A.F. Wright (Alan); A. Peters (Annette); E.R. Fox (Ervin); B.A. Oostra (Ben); H.K. Kroemer (Heyo); D.J. Couper (David); H. Völzke (Henry); H. Campbell (Harry); T. Meitinger (Thomas); M. Uda (Manuela); J.C.M. Witteman (Jacqueline); B.M. Psaty (Bruce); H.E. Wichmann (Heinz Erich); T.B. Harris (Tamara); S. Kääb (Stefan); D.S. Siscovick (David); Y. Jamshidi (Yalda); A.G. Uitterlinden (André); A.R. Folsom (Aaron); M.G. Larson (Martin); J.F. Wilson (James); B.W.J.H. Penninx (Brenda); H. Snieder (Harold); P.P. Pramstaller (Peter Paul); P. Tikka-Kleemola (Päivi); E. Lakatta (Edward); S.B. Felix (Stephan); V. Gudnason (Vilmundur); A. Pfeufer (Arne); S.R. Heckbert (Susan); B.H.Ch. Stricker (Bruno); E.A. Boerwinkle (Eric); C.J. O'Donnell (Christopher)
2010-01-01
textabstractHigher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel fa
Relation between the location of elements in the periodic table and tumor-uptake rate.
Ando, A; Ando, I; Hiraki, T; Hisada, K
1985-01-01
The bipositive ions and anions, with few exceptions, indicated a low tumor uptake rate. On the other hand, compounds of Hg, Au and Bi, which have a strong binding power to protein, showed a high tumor uptake rate. As Hg2+, Au+ and Bi3+ are soft acids according to the classification of Lewis acids, it was thought that these ions would bind strongly to soft bases (R-SH, R-S-) present in tumor tissue. For many hard acids such as 85Sr2+, 67Ga3+, 181Hf4+, and 95Nb5+, tumor uptake rates are shown as a function of ionic potentials (valency/ionic radii) of the metal ions. Considering the present data and previously reported results, it was presumed that hard acids of trivalence, quadrivalence and pentavalence would replace calcium in the calcium salts of hard bases (calcium salts of acid mucopolysaccharides, etc.). Ionic potentials of alkaline metals and Tl were small, but the tumor-uptake rate of these elements indicated various values. As Ge and Sb are bound by covalent bonds to chloride, GeCl4 and SbCl3 behaved differently from many metallic compounds in tumor tissue.
Rubinson, Kenneth A; Faraone, Antonio
2016-05-14
X-ray and neutron scattering have been used to provide insight into the structures of ionic solutions for over a century, but the probes have covered distances shorter than 8 Å. For the non-hydrolyzing salt SrI2 in aqueous solution, a locally ordered lattice of ions exists that scatters slow neutrons coherently down to at least 0.1 mol L(-1) concentration, where the measured average distance between scatterers is over 18 Å. To investigate the motions of these scatterers, coherent quasielastic neutron scattering (CQENS) data on D2O solutions with SrI2 at 1, 0.8, 0.6, and 0.4 mol L(-1) concentrations was obtained to provide an experimental measure of the diffusive transport rate for the motion between pairs of ions relative to each other. Because CQENS measures the motion of one ion relative to another, the frame of reference is centered on an ion, which is unique among all diffusion measurement methods. We call the measured quantity the pairwise diffusive transport rate Dp. In addition to this ion centered frame of reference, the diffusive transport rate can be measured as a function of the momentum transfer q, where q = (4π/λ)sin θ with a scattering angle of 2θ. Since q is related to the interion distance (d = 2π/q), for the experimental range 0.2 Å(-1)≤q≤ 1.0 Å(-1), Dp is, then, measured over interion distances from 40 Å to ≈6 Å. We find the measured diffusional transport rates increase with increasing distance between scatterers over the entire range covered and interpret this behavior to be caused by dynamic coupling among the ions. Within the model of Fickian diffusion, at the longer interionic distances Dp is greater than the Nernst-Hartley value for an infinitely dilute solution. For these nm-distance diffusional transport rates to conform with the lower, macroscopically measured diffusion coefficients, we propose that local, coordinated counter motion of at least pairs of ions is part of the transport process.
Dimoliatis Ioannis DK
2005-12-01
Full Text Available Abstract Background Previous studies on self-rated health among nurses have indicated an association of low job satisfaction and stress in relation to poor self-rated health. The relationship between self rated health and the specific work characteristics and health related behaviours of nurses to our knowledge have not been adequately studied. Objective To investigate the health profile of nurses working in hospitals in North West Greece and to examine the associations between self rated health (SRH and health related behaviours and work characteristics in this group of hospital employees. Methods A self-administered questionnaire was distributed to a random sample of 443 nurses working in all the hospitals in North West Greece. Regression analysis was used to examine the relationship of health related behaviours and work characteristics with self rated health among the nurses. Results A total of 353 responded to the questionnaire (response rate 80% of which 311 (88% were female and 42 (12% male. The mean age (standard deviation of the respondents was 36 years (5.6 and their mean years of working as nurses were 13.5 years (5.9. Almost half of the nurses' smoked, and about one third were overweight or obese. About 58% (206 of the nurses reported having poor health while 42% (147 reported having good health. Self-rated health was independently associated with gender, effort to avoid fatty foods and physical activity, according to multiple logistic regression analysis. Conclusion The population studied presented a relatively poor health profile, and a high proportion of poor SRH. Though female gender and effort to avoid fatty foods were associated with poor SRH, and exercise and white meat consumption with good SRH, specific work characteristics were not associated with SRH.
Sabine absorption coefficients to random incidence absorption coefficients
Jeong, Cheol-Ho
2014-01-01
Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a specimen and non-uniform intensity in the test chamber. In this study, several methods that convert Sabine absorption coefficients...... into random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...