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Sample records for 237u level density

  1. Proposed 237U Evaluation for the next ENDL Release

    SciTech Connect

    Brown, D; Summers, N; Thompson, I; Younes, W

    2007-11-07

    We detail the new LLNL evaluation of {sup 237}U for inclusion in both the next release of the ENDL and ENDF/B-VII databases. This evaluation is based on a combination of TALYS calculations, data fits and the earlier JEFF-3.1 evaluation. Our evaluation is in excellent agreement with published surrogate (n, f) data [11, 12, 13, 14, 18] and the unpublished LLNL surrogate (n,2n) data [16].

  2. Nuclear Level Densities

    SciTech Connect

    Grimes, S.M.

    2005-05-24

    Recent research in the area of nuclear level densities is reviewed. The current interest in nuclear astrophysics and in structure of nuclei off of the line of stability has led to the development of radioactive beam facilities with larger machines currently being planned. Nuclear level densities for the systems used to produce the radioactive beams influence substantially the production rates of these beams. The modification of level-density parameters near the drip lines would also affect nucleosynthesis rates and abundances.

  3. Nuclear Level Densities

    SciTech Connect

    Grimes, S. M.; Voinov, A.

    2009-01-28

    A summary of some recent level density research is presented. Although the subject is an old one, it is argued that a number of unanswered questions remain. These include uncertainties in related quantities such as the parity ratio and the spin cutoff parameter, which are needed to deduce level density parameters from resonance counting for low energy neutrons. Additional points of interest are the extent to which the low energy region shows constant temperature rather than Fermi gas energy dependence, whether the region below the neutron binding energy shows significant structure and whether the level density for fixed A shows a drop for neutron-rich and proton-rich nuclei compared to nuclei on the valley of stability.

  4. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    SciTech Connect

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F; Moody, K J; Norman, E B; Phair, L W; Fallon, P; Clark, R; Delaplanque, M; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S

    2005-08-16

    The authors have deduced the {sup 237}U(n,f) cross-section over an equivalent neutron energy range of 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He{sup 2+} beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions {sup 238}U({alpha},{alpha}'f) and {sup 236}U({alpha},{alpha}'f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). The energies of the scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} to 131{sup o}.

  5. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    SciTech Connect

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F S; Moody, K J; Norman, E B; Phair, L; Fallon, P; Clark, R M; Deleplanque, M A; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S; Ai, H; Beausang, C; Cridder, B

    2005-12-29

    The authors have deduced the cross section for {sup 237}U(n,f) over an equivalent neutron energy range from 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: {sup 238}U({alpha},{alpha}{prime}f) and {sup 236}U({alpha},{alpha}{prime}f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). Scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} and 131{sup o}.

  6. Level densities of heaviest nuclei

    NASA Astrophysics Data System (ADS)

    Bezbakh, A. N.; Shneidman, T. M.; Adamian, G. G.; Antonenko, N. V.

    2014-06-01

    The intrinsic level densities of superheavy nuclei in the α-decay chains of 296,298,300120 are calculated using the single-particle spectra obtained with the modified two-center shell model. The role of the shell and pairing effects on the level density as well as their quenching with excitation energy are studied. The extracted level density parameter is expressed as a function of mass number, ground-state shell correction, and excitation energy. The results are compared with the phenomenological values of level density parameters used to calculate the survival of excited heavy nuclei.

  7. First simultaneous measurement of fission and gamma probabilities of 237U and 239Np via surrogate reactions

    NASA Astrophysics Data System (ADS)

    Marini, P.; Ducasse, Q.; Jurado, B.; Aiche, M.; Mathieu, L.; Barreau, G.; Czajkowski, S.; Tsekhanovich, I.; Moro, A.; Lei, J.; Giacoppo, F.; Gorgen, A.; Tornyi; Audouin, L.; Tassan-Got, L.; Wilson, J. N.; Gunsing, F.; Guttormsen, M.; Larsen, A. C.; Lebois, M.; Renstrom, T.; Rose, S.; Siem, S.; Tveten, G. M.; Wiedeking, M.; Serot, O.; Boutoux, G.; Méot, V.; Morillon, B.; Denis-Petit, D.; Roig, O.; Oberstedt, S.; Oberstedt, A.

    2016-06-01

    Fission and gamma decay probabilities of 237U and 239Np have been measured, for the first time simultaneously in dedicated experiments, via the surrogate reactions 238U(3He, 4He) and 238U(3He,d), respectively. While a good agreement between our data and neutron-induced data is found for fission probabilities, gamma decay probabilities are several times higher than the corresponding neutron-induced data for each studied nucleus. We study the role of the different spin distributions populated in the surrogate and neutron-induced reactions. The compound nucleus spin distribution populated in the surrogate reaction is extracted from the measured gamma-decay probabilities, and used as input parameter in the statistical model to predict fission probabilities to be compared to our data. A strong disagreement between our data and the prediction is obtained. Preliminary results from an additional dedicated experiment confirm the observed discrepancies, indicating the need of a better understanding of the formation and decay processes of the compound nucleus.

  8. Initial Estimate of the 237U(n,f) Cross Section for 0.1 (less than) En (MeV) (less than or equal to) 20

    SciTech Connect

    Younes, W; Britt, H C; Becker, J A; Wilhelmy, J B

    2003-06-27

    In response to a request for a {sup 237}U(n,f) cross section evaluation up to E{sub n} = 20 MeV, they have married a data set from the previous reliable estimate [1-3] of the cross section up to E{sub n} = 2.5 MeV, to an estimate of the remaining cross section up to E{sub n} = 20 MeV, deduced from simple physics arguments. This straw-man, work-in-progress estimate of the {sup 237}U(n,f) cross section is intended to be used in sensitivity-test comparisons to other evaluations of the cross section (e.g., ENDF/B-VI [4] and ENDL [5]). The simple approach used in this work to generate a consistent cross section up to E{sub n} = 20 MeV is validated using the well-known {sup 235}U(n,f) cross section as a test case (see Fig. 1). The corresponding estimate of the {sup 237}U(n,f) cross section is plotted in Fig. 2 and listed in Table I.

  9. Nuclear level density: Shell-model approach

    NASA Astrophysics Data System (ADS)

    Sen'kov, Roman; Zelevinsky, Vladimir

    2016-06-01

    Knowledge of the nuclear level density is necessary for understanding various reactions, including those in the stellar environment. Usually the combinatorics of a Fermi gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally used parameters are also compared with standard phenomenological approaches.

  10. Applied uses of level density models

    SciTech Connect

    Arthur, E.D.; Guenther, P.T.; Smith, A.B.; Smith, D.L.; Argonne National Lab., IL )

    1989-01-01

    This paper addresses issues associated with the use of nuclear level density models in calculations made for data applications. The two most commonly used models, the Gilbert Cameron and the Back-Shifted Fermi Gas, are briefly summarized and examples are provided of recent efforts to improve their parameterization. Calculated particle emission spectra are compared with recent experimental data in order to assess performance and sensitivity to these models. Extrapolation of nuclear level densities for calculations involving nuclei away from stability poses special problems and examples of recent efforts to improve such extrapolations are cited. The sensitivity of current schemes in the modeling of fission transition state densities are explored through calculated (n,f) cross sections. Two newer phenomenological models, those of Ignatyuk and Schmidt, provide a more physically realistic description of level densities. Calculations concerning {sup 207}Pb(n,xn) cross sections compare results using the Ignatyuk formalism with the Gilbert Cameron results. 31 refs., 10 figs.

  11. Chaos and structure of level densities

    SciTech Connect

    Moller, Peter; Aberg, Sven; Uhrenholt, Henrik; Ickhikawa, Takatoshi

    2008-01-01

    The energy region of the first few MeV above the ground state shows interesting features of the nucleus. Beyond an ordered energy region just above the ground-state the dynamics changes, and chaotic features are observed in the neutron resonance region. The statistical properties of energies and wave-functions are common to all chaotic nuclei. However, if instead a global property, like the local level-density function is studied, strong structure effects emerge. In this contribution we discuss these two different facets of warm nuclei. In section 2 the onset of chaos with increasing excitation energy is discussed, with both experimental observations and proposed theoretical mechanisms as starting points. The structure of level densities in the same excitation energy region based on the two different starting points, is treated in section 3, where we give a short presentation of a newly developed combinatorial level-density modell. Some results from the model are presented and discussed. Two coexisting facets of warm nuclei, quantum chaos and structure of the level density, are considered. A newly developed combinatorial level-density model is presented, and the role of collective enhancements discussed. An example of extreme parity enhancement is shown.

  12. Mammographic breast density and serum phytoestrogen levels.

    PubMed

    Lowry, Sarah J; Sprague, Brian L; Aiello Bowles, Erin J; Hedman, Curtis J; Hemming, Jocelyn; Hampton, John M; Burnside, Elizabeth S; Sisney, Gale A; Buist, Diana S M; Trentham-Dietz, Amy

    2012-08-01

    Some forms of estrogen are associated with breast cancer risk as well as with mammographic density (MD), a strong marker of breast cancer risk. Whether phytoestrogen intake affects breast density, however, remains unclear. We evaluated the association between serum levels of phytoestrogens and MD in postmenopausal women. We enrolled 269 women, ages 55-70 yr, who received a screening mammogram and had no history of postmenopausal hormone use. Subjects completed a survey on diet and factors related to MD and provided a blood sample for analysis of 3 phytoestrogens: genistein, daidzein, and coumestrol. We examined whether mean percent MD was related to serum level of phytoestrogens, adjusting for age and body mass index. Genistein and daidzein levels correlated with self-reported soy consumption. Mean percent MD did not differ across women with different phytoestrogen levels. For example, women with nondetectable genistein levels had mean density of 11.0% [95% confidence intervals (CI) = 9.9-12.4], compared to 10.5% (95% CI = 8.0-13.7) and 11.2% (95% CI = 8.7-14.6) for < and ≥ median detectable levels, respectively. In a population with relatively low soy intake, serum phytoestrogens were not associated with mammographic density. Additional studies are needed to determine effects of higher levels, particularly given patterns of increasing phytoestrogen intake. PMID:22860715

  13. Pairing interaction effects in exciton level densities

    SciTech Connect

    Fu, C.Y.

    1989-01-01

    Recent progress in pairing corrections for exciton state-density formulas used in pre-compound nuclear reaction theories is reviewed. These correction factors are, strictly speaking, dependent on the nuclear excitation energy U and the exciton number n. A simple formula for (U,n)-dependent pairing corrections has been derived, based on the BCS pairing equations for constant single-particle spacing, for the exciton state-density formula for one kind of Fermion. It has been shown that the constant-pairing-energy correction used in standard state-density formulas, such U{sub 0} in Gilbert and Cameron, is a limiting case of the general (U,n)-dependent results. Spin cutoff factors with pairing effects were also obtained using the same theory and parameterized into an explicit (U,n)-dependent function, thereby defining a simple exciton level-density formula for applications in quantum mechanical precompound theories. Preliminary results from extending such simple pairing-interaction representations to level-density formulas for two kinds of Fermions are summarized. The results show that the ratios in the exciton level densities in the one-Fermion and two-Fermion approaches vary with both U and n, thus likely leading to differences in calculated compound to precompound ratios. However, the differences in the spin cutoff factors in the two cases are found to be rather small. 12 refs., 3 figs.

  14. Statistical approach to nuclear level density

    SciTech Connect

    Sen'kov, R. A.; Horoi, M.; Zelevinsky, V. G.

    2014-10-15

    We discuss the level density in a finite many-body system with strong interaction between the constituents. Our primary object of applications is the atomic nucleus but the same techniques can be applied to other mesoscopic systems. We calculate and compare nuclear level densities for given quantum numbers obtained by different methods, such as nuclear shell model (the most successful microscopic approach), our main instrument - moments method (statistical approach), and Fermi-gas model; the calculation with the moments method can use any shell-model Hamiltonian excluding the spurious states of the center-of-mass motion. Our goal is to investigate statistical properties of nuclear level density, define its phenomenological parameters, and offer an affordable and reliable way of calculation.

  15. Regulation of high density lipoprotein levels

    SciTech Connect

    Krauss, R.M.

    1982-03-01

    An increasing awareness of the physiologic and pathologic importance of serum high density lipoproteins (HDL) has led to a large number of observations regarding factors which influence their concentrations. HDL consists of a heterogeneous collection of macromolecules with diverse physical properties and chemical constituents. While laboratory techniques have made it possible to measure HDL and their individual components, there are as yet large gaps in our knowledge of the biochemical mechanisms and clinical significance of changes in these laboratory parameters. In this review, current concepts of the structure and metabolism of HDL will be briefly summarized, and the factors influencing their levels in humans will be surveyed. 313 references.

  16. Connection between the Strutinsky level density and the semiclassical level density

    SciTech Connect

    Mohammed-Azizi, B.; Medjadi, D. E.

    2006-11-15

    We establish an analytical link between the level density obtained by means of the Strutinsky averaging method and the semiclassical level density. This link occurs only in the so-called asymptotic limit. It turns out that the Strutinsky method amounts to an approximation to the semiclassical method. This approximation contains an unavoidable remainder that constitutes an intrinsic noise in comparison to the semiclassical method. Thus, the problem of the dependency of the Strutinsky procedure on the two free smoothing parameters of the averaging is intimately connected to this noise. However, we demonstrate that the noise of the method is small in the average density of states and in the average energy, whereas it might be non-negligible in the shell correction itself. To improve this method, we give a rule that consists simply of minimizing the relative error for the average energy.

  17. Level densities and shell corrections of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bezbakh, A. N.; Shneidman, T. M.; Adamian, G. G.; Antonenko, N. V.

    2015-02-01

    The intrinsic level densities of superheavy nuclei in the α-decay chains of 296;298;300120 nuclei are calculated using the single-particle spectra obtained with the modifed two-center shell model. The level density parameters are extracted and compared with their phenomenological values used in the calculations of the survival of excited heavy nuclei. The dependences of the level density parameters on the mass and charge numbers as well as on the ground-state shell corrections are studied.

  18. Parity dependence of level densities in sup 49 V

    SciTech Connect

    York, B.W.

    1991-01-01

    In this research, we have studied {sup 48}Ti(p, p{sub 1}) and {sup 48}(p, p{sub 1}{gamma}) in an effort to determine the dependence of level densities on parity in the compound nucleus {sup 49}V. This nuclide was chosen because of the high level density of the {sup 49}V system (leading to good statistical accuracy) and because the target is zero spin (making the assignment of J easier). 5 refs., 3 figs.

  19. Determination of the nuclear level density at high excitation energy

    SciTech Connect

    Chbihi, A.; Sobotka, L.G.; Nicolis, N.G.; Sarantites, D.G.; Stracener, D.W.; Majka, Z. ); Hensley, D.C.; Beene, J.R.; Halbert, M.L. )

    1991-02-01

    Evaporation simulations are presented to illustrate the problems associated with the determination of the nuclear level density constant at high excitation energy from evaporation spectra. The methods of using either the total (whole chain) spectra or the difference (from two different initial excitation energies) spectra are discussed. Data from the study of the reaction 701 MeV {sup 28}Si+{sup 100}Mo are presented and both methods are used to extract the level density constant. We find that in order to reproduce the slopes of the light particle spectra the level density constant must have a value near 1/10{ital A}-- 1 / 11 {ital A} for excited nuclei with statistical temperatures in the range of 3.5 to 5.5 MeV. This presumes that the only parameter adjustment required to treat the decay of highly exited nuclei is the level density constant. If this is so, the shapes of the evaporation spectra imply a reduction in the level density constant from the value required to explain the decay of less highly excited nuclei, a conclusion reached by others. However, the reduced level density constant leads to an overproduction of deuterons and tritons. This suggests that a more complicated set of parameter adjustments may be required to treat the decay of highly excited nuclei.

  20. Effect of interstitial low level laser stimulation in skin density

    NASA Astrophysics Data System (ADS)

    Jang, Seulki; Ha, Myungjin; Lee, Sangyeob; Yu, Sungkon; Park, Jihoon; Radfar, Edalat; Hwang, Dong Hyun; Lee, Han A.; Kim, Hansung; Jung, Byungjo

    2016-03-01

    As the interest in skin was increased, number of studies on skin care also have been increased. The reduction of skin density is one of the symptoms of skin aging. It reduces elasticity of skin and becomes the reason of wrinkle formation. Low level laser therapy (LLLT) has been suggested as one of the effective therapeutic methods for skin aging as in hasten to change skin density. This study presents the effect of a minimally invasive laser needle system (MILNS) (wavelength: 660nm, power: 20mW) in skin density. Rabbits were divided into three groups. Group 1 didn't receive any laser stimulation as a control group. Group 2 and 3 as test groups were exposed to MILNS with energy of 8J and 6J on rabbits' dorsal side once a week, respectively. Skin density of rabbits was measured every 12 hours by using an ultrasound skin scanner.

  1. A Code For Combinatorial Calculation of Level Densities.

    Energy Science and Technology Software Center (ESTSC)

    1990-11-26

    Version 00 ICAR performs state and level density calculations for a specified type of nucleon. Calculations can be carried out in terms of the free gas model or in the frame of the BCS formalism to account for the pairing interaction.

  2. Level density from evaporation spectra for proton rich nuclei

    NASA Astrophysics Data System (ADS)

    Voinov, Alexander

    2005-04-01

    The level density is an important characteristic of atomic nuclei. It tells us about the nuclear structure and is needed to calculate reaction rates. The experimental information about the level density and corresponding model parameter systematics are available for the nuclei close to the stability line but little is known for the nuclei beyond the stability line. It follows from theoretical consideration that several physical effects might give the of Fermi-gas parameter `a' dependence on N and/or Z rather than on simply on A [1]. To study this and other features, the level density from neutron evaporation spectra has been measured for proton-rich nuclei ^60Zn and ^56Ni as well as for corresponding stable nuclei ^60Ni and^ 56Fe of the same A. Targets of ^58Ni, ^54Fe,^ 58Fe, and ^55Mn were bombarded with beams of 3He and deuterium at Ohio University's Edwards Accelerator Laboratory. Neutron energies were determined by the time-of-flight method. The different level density models have been tested in the excitation energy interval up to 8-10 MeV and the best parameters have been found. The results are compared to available systematics as well as to calculations performed on the basis of microscopic model recommended in RIPL data base. [1] S.I. Al-Quraishi, S.M.Grimes, T.N. Massey and D.A.Resler, Phys.Rev. C63, 065803 (2001).

  3. Generalized Freud's equation and level densities with polynomial potential

    NASA Astrophysics Data System (ADS)

    Boobna, Akshat; Ghosh, Saugata

    2013-08-01

    We study orthogonal polynomials with weight $\\exp[-NV(x)]$, where $V(x)=\\sum_{k=1}^{d}a_{2k}x^{2k}/2k$ is a polynomial of order 2d. We derive the generalised Freud's equations for $d=3$, 4 and 5 and using this obtain $R_{\\mu}=h_{\\mu}/h_{\\mu -1}$, where $h_{\\mu}$ is the normalization constant for the corresponding orthogonal polynomials. Moments of the density functions, expressed in terms of $R_{\\mu}$, are obtained using Freud's equation and using this, explicit results of level densities as $N\\rightarrow\\infty$ are derived.

  4. Nuclear Level Densities Off of the Stability Line

    SciTech Connect

    Grimes, Steven M.; Massey, T. N.; Oginni, B. M.; Shukla, S.; Voinov, A.

    2008-04-17

    Nuclear level densities have been extensively studied on or near the valley of stability. Because the data base is so sparse away from the valley of stability, the systematics found for stable nuclei are assumed to apply off the line of stability as well. A model which predicts different systematics off of the stability line is examined. A pair of recent measurements provide tentative support for the new hypothesis, though it is clear additional data are needed.

  5. Level density and thermodynamic properties of dysprosium isotopes

    NASA Astrophysics Data System (ADS)

    Nyhus, H. T.; Siem, S.; Guttormsen, M.; Larsen, A. C.; Bürger, A.; Syed, N. U. H.; Toft, H. K.; Tveten, G. M.; Voinov, A.

    2012-01-01

    163,164Dy nuclei have been measured by use of the Oslo method on data from pick-up (3He,α) and inelastic scattering (3He,3He') reactions, respectively. The level densities for these dysprosium isotopes together with previously measured 160-162Dy are extracted in the region below the neutron binding energy. Thermodynamic properties are deduced within both micro-canonical and canonical ensemble theories. A phase transition from the pair-correlated state at low energies to a less correlated or uncorrelated state is studied in both ensembles. It is investigated whether the temperature of the nucleus is constant or a varying function of excitation energy. It is found that above an excitation energy of 3 MeV the temperature of all five dysprosium nuclei have a constant value within the experimental uncertainties. The impact of a constant-temperature level density versus a Fermi gas level density is discussed with respect to the canonical heat capacity.

  6. Critical noise levels for low-density parity check decoding

    NASA Astrophysics Data System (ADS)

    Mourik, J. Van; Saad, D.; Kabashima, Y.

    2002-08-01

    We determine the critical noise level for decoding low-density parity check error-correcting codes based on the magnetization enumerator (M), rather than on the weight enumerator (W) employed in the information theory literature. The interpretation of our method is appealingly simple, and the relation between the different decoding schemes such as typical pairs decoding, MAP, and finite temperature decoding (MPM) becomes clear. In addition, our analysis provides an explanation for the difference in performance between MN and Gallager codes. Our results are more optimistic than those derived using the methods of information theory and are in excellent agreement with recent results from another statistical physics approach.

  7. Constraining the level density using fission of lead projectiles

    NASA Astrophysics Data System (ADS)

    Rodríguez-Sánchez, J. L.; Benlliure, J.; Álvarez-Pol, H.; Audouin, L.; Ayyad, Y.; Bélier, G.; Boutoux, G.; Casarejos, E.; Chatillon, A.; Cortina-Gil, D.; Gorbinet, T.; Heinz, A.; Kelić-Heil, A.; Laurent, B.; Martin, J.-F.; Paradela, C.; Pellereau, E.; Pietras, B.; Ramos, D.; Rodríguez-Tajes, C.; Rossi, D. M.; Simon, H.; Taïeb, J.; Vargas, J.; Voss, B.

    2015-10-01

    The nuclear level density is one of the main ingredients for the statistical description of the fission process. In this work, we propose to constrain the description of this parameter by using fission reactions induced by protons and light ions on 208Pb at high kinetic energies. The experiment was performed at GSI (Darmstadt), where the combined use of the inverse kinematics technique with an efficient detection setup allowed us to measure the atomic number of the two fission fragments in coincidence. This measurement permitted us to obtain with high precision the partial fission cross sections and the width of the charge distribution as a function of the atomic number of the fissioning system. These data and others previously measured, covering a large range in fissility, are compared to state-of-the-art calculations. The results reveal that total and partial fission cross sections cannot unambiguously constrain the level density at ground-state and saddle-point deformations and additional observables, such as the width of the charge distribution of the final fission fragments, are required.

  8. Benchmarking mean-field approximations to level densities

    NASA Astrophysics Data System (ADS)

    Alhassid, Y.; Bertsch, G. F.; Gilbreth, C. N.; Nakada, H.

    2016-04-01

    We assess the accuracy of finite-temperature mean-field theory using as a standard the Hamiltonian and model space of the shell model Monte Carlo calculations. Two examples are considered: the nucleus 162Dy, representing a heavy deformed nucleus, and 148Sm, representing a nearby heavy spherical nucleus with strong pairing correlations. The errors inherent in the finite-temperature Hartree-Fock and Hartree-Fock-Bogoliubov approximations are analyzed by comparing the entropies of the grand canonical and canonical ensembles, as well as the level density at the neutron resonance threshold, with shell model Monte Carlo calculations, which are accurate up to well-controlled statistical errors. The main weak points in the mean-field treatments are found to be: (i) the extraction of number-projected densities from the grand canonical ensembles, and (ii) the symmetry breaking by deformation or by the pairing condensate. In the absence of a pairing condensate, we confirm that the usual saddle-point approximation to extract the number-projected densities is not a significant source of error compared to other errors inherent to the mean-field theory. We also present an alternative formulation of the saddle-point approximation that makes direct use of an approximate particle-number projection and avoids computing the usual three-dimensional Jacobian of the saddle-point integration. We find that the pairing condensate is less amenable to approximate particle-number projection methods because of the explicit violation of particle-number conservation in the pairing condensate. Nevertheless, the Hartree-Fock-Bogoliubov theory is accurate to less than one unit of entropy for 148Sm at the neutron threshold energy, which is above the pairing phase transition. This result provides support for the commonly used "back-shift" approximation, treating pairing as only affecting the excitation energy scale. When the ground state is strongly deformed, the Hartree-Fock entropy is significantly

  9. Capacitance-level/density monitor for fluidized-bed combustor

    DOEpatents

    Fasching, George E.; Utt, Carroll E.

    1982-01-01

    A multiple segment three-terminal type capacitance probe with segment selection, capacitance detection and compensation circuitry and read-out control for level/density measurements in a fluidized-bed vessel is provided. The probe is driven at a high excitation frequency of up to 50 kHz to sense quadrature (capacitive) current related to probe/vessel capacitance while being relatively insensitive to the resistance current component. Compensation circuitry is provided for generating a negative current of equal magnitude to cancel out only the resistive component current. Clock-operated control circuitry separately selects the probe segments in a predetermined order for detecting and storing this capacitance measurement. The selected segment acts as a guarded electrode and is connected to the read-out circuitry while all unselected segments are connected to the probe body, which together form the probe guard electrode. The selected probe segment capacitance component signal is directed to a corresponding segment channel sample and hold circuit dedicated to that segment to store the signal derived from that segment. This provides parallel outputs for display, computer input, etc., for the detected capacitance values. The rate of segment sampling may be varied to either monitor the dynamic density profile of the bed (high sampling rate) or monitor average bed characteristics (slower sampling rate).

  10. Possibility of determination of the asymptotic level-density parameter

    SciTech Connect

    Kudyaev, G.A.; Ostapenko, Y.B.; Svirin, M.I.; Smirenkin, G.N.

    1988-02-01

    We investigate the sensitivity of the fissility of nuclei to the parameters of the density of excited levels and conclude that the nuclei in the region of Pb are most favorable for an experimental estimate of the asymptotic parameter a-italic-tilde = ..cap alpha..A. The mean value ..cap alpha.. = 0.086 +- 0.009 MeV/sup -1/ is found from analysis of the fission of seven nuclei from /sup 201/Tl to /sup 213/At. This value is in agreement with the phenomenological description of the energy dependence a(U) (..cap alpha.. = 0.093 MeV/sup -1/) and with the theoretical prediction ..cap alpha.. = 0.09 MeV/sup -1/ obtained for a Woods-Saxon potential.

  11. Properties of {sup 112}Cd from the (n,n'{gamma}) reaction: Levels and level densities

    SciTech Connect

    Garrett, P. E.; Lehmann, H.; Jolie, J.; McGrath, C. A.; Yeh, Minfang; Younes, W.; Yates, S. W.

    2001-08-01

    Levels in {sup 112}Cd have been studied through the (n,n'{gamma}) reaction with monoenergetic neutrons. An extended set of experiments that included excitation functions, {gamma}-ray angular distributions, and {gamma}{gamma} coincidence measurements was performed. A total of 375 {gamma} rays were placed in a level scheme comprising 200 levels (of which 238 {gamma}-ray assignments and 58 levels are newly established) up to 4 MeV in excitation. No evidence to support the existence of 47 levels as suggested in previous studies was found, and these have been removed from the level scheme. From the results, a comparison of the level density is made with the constant temperature and back-shifted Fermi gas models. The back-shifted Fermi gas model with the Gilbert-Cameron spin cutoff parameter provided the best overall fit. Without using the neutron resonance information and only fitting the cumulative number of low-lying levels, the level density parameters extracted are a sensitive function of the maximum energy used in the fit.

  12. Determination of nuclear level densities from experimental information

    SciTech Connect

    Cole, B.J. ); Davidson, N.J. , P.O. Box 88, Manchester M60 1QD ); Miller, H.G. )

    1994-10-01

    A novel information theory based method for determining the density of states from prior information is presented. The energy dependence of the density of states is determined from the observed number of states per energy interval, and model calculations suggest that the method is sufficiently reliable to calculate the thermal properties of nuclei over a reasonable temperature range.

  13. The role of seniority-zero states in nuclear level densities

    DOE PAGESBeta

    Åberg, S.; Carlsson, B. G.; Døssing, Th.; Möller, P.

    2015-06-01

    At low excitation energies seniority-zero states dominate the level density of K=0 bands in deformed even–even nuclei, while they play no role at higher excitation energies. We describe the level densities in a Fermi-gas model as well as in a combinatorial level-density model and compare to detailed experimental data for some rare-earth nuclei.

  14. Persistence of Vibrational Collectivity in Nuclear Level Densities

    NASA Astrophysics Data System (ADS)

    Nakada, H.; Matsuyama, E.; Özen, C.

    2016-06-01

    By applying the particle-number projection to the finite-temperature BCS theory to the state densities in the rare-earth nuclei and comparing its results to the SMMC ones, we investigate effects of the particle-number conservation on the collective enhancement factor for the state densities. Once we restore the particle-number conservation, the rapid decay of vibrational enhancement disappears. This suggests that the vibrational collectivity may survive up to higher energy and the relevant enhancement factor is insensitive to the excitation energy.

  15. Herbivore effects on plant species density at varying productivity levels

    USGS Publications Warehouse

    Gough, L.; Grace, J.B.

    1998-01-01

    Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate herbivory. After three growing seasons, fertilization increased community biomass in all plots, but decreased species density (the number of species per unit area) only in plots protected from herbivory. Herbivory alone did not alter species density at either site. At the brackish marsh, herbivory caused a shift in dominance in the fertilized plots from a species that is considered the competitive dominant, but is selectively eaten, to another less palatable species. At the fresh marsh, increased dead biomass in the absence of herbivory and in the fertilized plots probably contributed to the decrease in species density, perhaps by limiting germination of annuals. Our results support those of other fertilization studies in which plant species density decreases with increased biomass, but only in those plots protected from herbivory.

  16. Core-level shifts from density-functional computations

    NASA Astrophysics Data System (ADS)

    Pedocchi, Luca; Russo, Nino; Salahub, Dennis R.

    1993-05-01

    The C 1s x-ray photoelectron spectroscopy binding energies of a series of organic (CO, CH4, C2H2, HCHO, CH3CCH, C6H6) and inorganic [Ni(CO)4, Mo(CO)6] molecules have been calculated by using the linear-combination of Gaussian-type orbitals local- and nonlocal-spin-density (LCGTO-LSD and LCGTO-NLSD) methods. The calculated C 1s chemical shifts are in very good agreement with experiment. The differences between experimental and theoretical shifts are found to be less than 0.5 eV. It is shown that the addition of nonlocal corrections improves the agreement with the experimental data.

  17. Level densities of {sup 44}Sc and {sup 47}Ti from different experimental techniques

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Massey, T.; Schiller, A.; Larsen, A. C.; Guttormsen, M.; Siem, S.; Syed, N. U. H.

    2008-03-15

    The level densities of {sup 44}Sc and {sup 47}Ti have been determined from measurements of particle evaporation spectra from the compound nuclear reaction {sup 3}He+{sup 45}Sc with an 11 MeV {sup 3}He beam. The level density of {sup 44}Sc has been compared to the level density obtained from an independent experimental method based on an analysis of {alpha}-{gamma} coincidences from the transfer reaction {sup 45}Sc({sup 3}He,{alpha}{gamma}){sup 44}Sc. The good agreement between the two experiments indicates the reliability of the level density obtained. Some level density systematics have been tested against the experimental data. New Fermi-gas level density parameters have been derived.

  18. Shampoo, Soy Sauce, and the Prince's Pendant: Density for Middle-Level Students

    ERIC Educational Resources Information Center

    Chandrasekhar, Meera; Litherland, Rebecca

    2006-01-01

    In this article, the authors describe a series of activities they have used with middle-level students. The first set of lessons explores density through the layering of liquids. In the second set, they use some of the same liquids to explore the density of solids. The third set investigates how temperature affects the density of…

  19. IAEA advisory group meeting on basic and applied problems of nuclear level densities

    SciTech Connect

    Bhat, M.R.

    1983-06-01

    Separate entries were made in the data base for 17 of the 19 papers included. Two papers were previously included in the data base. Workshop reports are included on (1) nuclear level density theories and nuclear model reaction cross-section calculations and (2) extraction of nuclear level density information from experimental data. (WHK)

  20. Bone density and hemoglobin levels in older persons: results from the InCHIANTI study.

    PubMed

    Cesari, Matteo; Pahor, Marco; Lauretani, Fulvio; Penninx, Brenda W H J; Bartali, Benedetta; Russo, Roberto; Cherubini, Antonio; Woodman, Richard; Bandinelli, Stefania; Guralnik, Jack M; Ferrucci, Luigi

    2005-06-01

    Hypoxemia has been recognized as a risk factor for bone loss. The aim of the present study is to investigate the relationship of bone mass and density measures with anemia and hemoglobin levels in a large sample of older community-dwelling persons. The study is based on data from 950 participants enrolled in the "Invecchiare in Chianti" (Aging in the Chianti area, InCHIANTI) study. All the analyses were performed considering continuous hemoglobin levels as well as the dichotomous anemia variable (defined according to WHO criteria as hemoglobin < 12 g/dl in women and < 13 g/dl in men). A peripheral quantitative computerized tomography (pQCT) scan of the right calf was performed in all participants to evaluate total bone density, trabecular bone density, cortical bone density, and the ratio between cortical and total bone area. Linear regression analyses were used to assess the multivariate relationship of pQCT bone measures with anemia and hemoglobin levels after adjustment for demographics, chronic conditions, muscle strength and biological variables. Participants were 75.0 (SD 6.9) years old. In our sample, 101 participants (10.6%) were anemic. In women, coefficients from adjusted linear regression analyses evaluating the association between pQCT bone measures (per SD increase) and hemoglobin levels/anemia showed significant associations of anemia with total bone density (beta = -0.335, SE = 0.163; P = 0.04) and cortical bone density (beta = -0.428, SE = 0.160; P = 0.008). Relationships with borderline significance were found for the associations of anemia with trabecular bone density and the ratio between cortical and total bone area. Significant associations were found between hemoglobin levels and trabecular bone density (beta = 0.112, SE = 0.049; P = 0.02), total bone density (beta = 0.101, SE = 0.046; P = 0.03), cortical bone density (beta = 0.100, SE = 0.046; P = 0.03) and the ratio between cortical bone and total area (beta = 0.092, SE = 0.045; P = 0

  1. Level densities of iron isotopes and low-energy enhancement of {gamma}-strength function

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Hornish, M. J.; Massey, T. N.; Agvaanluvsan, U.; Algin, E.; Belgya, T.; Guttormsen, M.; Rekstad, J.; Siem, S.; Mitchell, G. E.; Schiller, A.

    2006-03-13

    The neutron spectrum from the 55Mn(d, n)56Fe reaction has been measured at Ed = 7 MeV. The level density of 56Fe obtained from neutron evaporation spectrum has been compared to the level density obtained from Oslo-type 57Fe(3He, {alpha}{gamma})56Fe experiment. The good agreement supports the recent results including the low-energy enhancement in the {gamma}-strength function for iron isotopes. The new level density function allowed us to investigate an excitation energy dependence of this enhancement, which is shown to increase with increasing excitation energy.

  2. Microscopic-macroscopic method for studying single-particle level density of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bezbakh, A. N.; Shneidman, T. M.; Adamian, G. G.; Antonenko, N. V.

    2014-04-01

    The intrinsic level densities of superheavy nuclei in the a-decay chains of 296,298,300120 nuclei are calculated using the single-particle spectra obtained with the modified two-center shell model. The level density parameters are extracted and compared with their phenomenological values used in the calculations of the survival of excited heavy nuclei. The dependences of the level density parameters on the mass and charge numbers as well as on the ground-state shell corrections are studied.

  3. Effects of prebiotic, protein level, and stocking density on performance, immunity, and stress indicators of broilers.

    PubMed

    Houshmand, M; Azhar, K; Zulkifli, I; Bejo, M H; Kamyab, A

    2012-02-01

    An experiment was conducted to determine the effects of period on the performance, immunity, and some stress indicators of broilers fed 2 levels of protein and stocked at a normal or high stocking density. Experimental treatments consisted of a 2 × 2 × 2 factorial arrangement with 2 levels of prebiotic (with or without prebiotic), 2 levels of dietary CP [NRC-recommended or low CP level (85% of NRC-recommended level)], and 2 levels of stocking density (10 birds/m(2) as the normal density or 16 birds/m(2) as the high density), for a total of 8 treatments. Each treatment had 5 replicates (cages). Birds were reared in 3-tiered battery cages with wire floors in an open-sided housing system under natural tropical conditions. Housing and general management practices were similar for all treatment groups. Starter and finisher diets in mash form were fed from 1 to 21 d and 22 to 42 d of age, respectively. Supplementation with a prebiotic had no significant effect on performance, immunity, and stress indicators (blood glucose, cholesterol, corticosterone, and heterophil:lymphocyte ratio). Protein level significantly influenced broiler performance but did not affect immunity or stress indicators (except for cholesterol level). The normal stocking density resulted in better FCR and also higher antibody titer against Newcastle disease compared with the high stocking density. However, density had no significant effect on blood levels of glucose, cholesterol, corticosterone, and the heterophil:lymphocyte ratio. Significant interactions between protein level and stocking density were observed for BW gain and final BW. The results indicated that, under the conditions of this experiment, dietary addition of a prebiotic had no significant effect on the performance, immunity, and stress indicators of broilers. PMID:22252353

  4. The study of the role of the two-body force in determining level densities

    NASA Astrophysics Data System (ADS)

    Huang, Po-Lin

    The study of the role of the two-body force in determining level densities explored the characteristics of the two-body force and their impact on nuclear level densities. Two different theoretical approaches, the statistical mechanical model and moment expansion method, were used for the determining the impact of the two-body force on level densities. Discrete levels in the lower excitation region were compiled to provide information about level density systematics. A shell model calculation for a number of light nuclei allowed a test of the input parameters including single particle energies and two-body matrix elements. Generally good agreement was found between the calculated and observed energies of low-lying states. A comparison of the results obtained with three widely used interactions for nuclei with mass numbers 18 and 20 allowed some insight into the two-body interaction and the possibilities for improving it. For the level density calculations twenty four nuclei with mass numbers between 20 and 41 were used. Both the values from tabulations of low-lying levels and the results from previous studies of level densities at 7 Mev and at 20 Mev were included. It was found that the parameters derived from the higher energy measurements gave poor results at energies below 5 Mev. The discrepancies appeared to be related to problems in determining one of the two parameters involved. Two approaches were used in an effort to improve the precision of this parameter. Both were reasonably successful. Calculations of the level of density using a super conducting model within a statistical mechanical framework and a full two-body interaction utilizing a moment method approach were completed. Both gave a reasonably good representation of the data. An examination of the significance of the analysis for future study of the two body force and of nuclear level densities is presented.

  5. Effects of population density on corticosterone levels of prairie voles in the field.

    PubMed

    Blondel, Dimitri V; Wallace, Gerard N; Calderone, Stefanie; Gorinshteyn, Marija; St Mary, Colette M; Phelps, Steven M

    2016-01-01

    High population density is often associated with increased levels of stress-related hormones, such as corticosterone (CORT). Prairie voles (Microtus ochrogaster) are a socially monogamous species known for their large population density fluctuations in the wild. Although CORT influences the social behavior of prairie voles in the lab, the effect of population density on CORT has not previously been quantified in this species in the field. We validated a non-invasive hormone assay for measuring CORT metabolites in prairie vole feces. We then used semi-natural enclosures to experimentally manipulate population density, and measured density effects on male space use and fecal CORT levels. Our enclosures generated patterns of space use and social interaction that were consistent with previous prairie vole field studies. Contrary to the positive relationship between CORT and density typical of other taxa, we found that lower population densities (80 animals/ha) produced higher fecal CORT than higher densities (240/ha). Combined with prior work in the lab and field, the data suggest that high prairie vole population densities indicate favorable environments, perhaps through reduced predation risk. Lastly, we found that field animals had lower fecal CORT levels than laboratory-living animals. The data emphasize the usefulness of prairie voles as models for integrating ecological, evolutionary, and mechanistic questions in social behavior. PMID:26342968

  6. Increases in Serum Estrone Sulfate Level Are Associated with Increased Mammographic Density during Menopausal Hormone Therapy

    PubMed Central

    Crandall, Carolyn J.; Guan, Min; Laughlin, Gail A.; Ursin, Giske A.; Stanczyk, Frank Z.; Ingles, Sue A.; Barrett-Connor, Elizabeth; Greendale, Gail A.

    2009-01-01

    Background Menopausal hormone therapy increases mammographic density. We determined whether increases in serum estrone sulfate (E1S) levels during menopausal hormone therapy predict increased mammographic density. Methods We measured percent mammographic density and serum E1S levels in 428 participants of the Postmenopausal Estrogen/Progestin Interventions study who were randomly assigned to daily conjugated equine estrogen (CEE) 0.625 mg alone, CEE + daily medroxyprogesterone acetate (MPA) 2.5 mg, CEE + cyclical MPA (10 mg days 1-12 per 28-day cycle), or CEE + cyclical micronized progesterone (10 mg days 1-12). Serum E1S levels were determined by RIA. Information about covariates was determined by annual questionnaire. Using linear regression, we determined the association between change in E1S level from baseline to 12 months and change in percent mammographic density (by semiquantitative interactive threshold method). Results After controlling for baseline mammographic density, age, body mass index, alcohol intake, parity, smoking, ethnicity, physical activity, and age at first pregnancy, mammographic density increased by 1.3% for every 1 ng/mL increase in E1S level (P < 0.0001). The association between change in E1S level and change in mammographic density differed by treatment group (greater effect in CEE + cyclical MPA group versus CEE group; P = 0.05). After controlling for treatment group, change in the ratio of E1S to E1 was also positively associated with change in mammographic density. Conclusions Increases in serum E1S levels during menopausal hormone therapy are associated with increases in mammographic density. The relative contribution of E1S and E1 to stimulation of breast tissue awaits further elucidation. PMID:18628419

  7. Studying Nuclear Level Densities of 238U in the Nuclear Reactions within the Macroscopic Nuclear Models

    NASA Astrophysics Data System (ADS)

    Razavi, Rohallah; Rahmatinejad, Azam; Kakavand, Tayeb; Taheri, Fariba; Aghajani, Maghsood; Khooy, Asghar

    2016-02-01

    In this work the nuclear level density parameters of 238U have been extracted in the back-shifted Fermi gas model (BSFGM), as well as the constant temperature model (CTM), through fitting with the recent experimental data on nuclear level densities measured by the Oslo group. The excitation functions for 238U(p,2nα)233Pa, and 238U(p,4n)235Np reactions and the fragment yields for the fragments of the 238U(p,f) reaction have been calculated using obtained level density parameters. The results are compared to their corresponding experimental values. It was found that the extracted excitation functions and the fragment yields in the CTM coincide well with the experimental values in the low-energy region. This finding is according to the claim made by the Oslo group that the extracted level densities of 238U show a constant temperature behaviour.

  8. DENSITY LEVELS OF PATHOGENIC ORGANISMS IN MUNICIPAL WASTEWATER SLUDGE: A LITERATURE REVIEW

    EPA Science Inventory

    This report presents a critical review of the literature from laboratory and full scale studies regarding density levels of indicator and pathogenic organisms in municipal wastewater sludges and septage. The effectiveness of conventional municipal sludge stabilization processes (...

  9. Test of nuclear level density inputs for Hauser-Feshbach model calculations

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Hornish, M. J.; Massey, T. N.; Salas, A.

    2007-10-15

    The energy spectra of neutrons, protons, and {alpha}-particles have been measured from the d+{sup 59}Co and {sup 3}He+{sup 58}Fe reactions leading to the same compound nucleus, {sup 61}Ni. The experimental cross sections have been compared to Hauser-Feshbach model calculations using different input level density models. None of them have been found to agree with experiment. It manifests the serious problem with available level density parametrizations especially those based on neutron resonance spacings and density of discrete levels. New level densities and corresponding Fermi-gas parameters have been obtained for reaction product nuclei such as {sup 60}Ni, {sup 60}Co, and {sup 57}Fe.

  10. The shell model Monte Carlo approach to level densities: Recent developments and perspectives

    NASA Astrophysics Data System (ADS)

    Alhassid, Y.

    2015-12-01

    We review recent advances in the shell model Monte Carlo approach for the microscopic calculation of statistical and collective properties of nuclei. We discuss applications to the calculation of i) level densities in nickel isotopes, implementing a recent method to circumvent the odd-particle sign problem; ii) state densities in heavy nuclei; iii) spin distributions of nuclear levels; and iv) finite-temperature quadrupole distributions.

  11. Effects of level density parameter on the superheavy production in cold fusion

    NASA Astrophysics Data System (ADS)

    Pahlavani, M. R.; Alavi, S. A.

    2014-12-01

    By using semiclassical method and considering Woods-Saxon and Coulomb potentials, the level density parameter a was calculated for three superheavy nuclei 270110, 278112 and 290116. Obtained results showed that the value of level density parameter of these nuclei is near to the simple relation a ≈ A/10. In framework of the dinuclear system model, the effects of level density parameter on the probability of the formation of a compound nucleus, the ratio of neutron emission width and fission width, and evaporation residue cross-section of three cold fusion reactions 62Ni+208Pb, 70Zn+208Pb and 82Se+208Pb, leading to superheavy elements were investigated. The findings indicate that the level density parameter play a significant role in calculations of heavy-ion fusion-fission reactions. The obtained results in the case of a = A/12 have larger values in comparison with calculated level density parameter with Woods-Saxon potential (aWS) and a = A/10. The theoretical results of the evaporation residue cross-section are very sensitive to the choice of level density parameter. The calculated values with aWS are in good agreement with experimental values.

  12. Orthometric corrections from leveling, gravity, density and elevation data: a case study in Taiwan

    NASA Astrophysics Data System (ADS)

    Hwang, C.; Hsiao, Y.-S.

    2003-08-01

    A new orthometric correction (OC) formula is presented and tested with various mean gravity reduction methods using leveling, gravity, elevation, and density data. For mean gravity computations, the Helmert method, a modified Helmert method with variable density and gravity anomaly gradient, and a modified Mader method were used. An improved method of terrain correction computation based on Gaussian quadrature is used in the modified Mader method. These methods produce different results and yield OCs that are greater than 10 cm between adjacent benchmarks (separated by sim2 km) at elevations over 3000 m. Applying OC reduces misclosures at closed leveling circuits and improves the results of leveling network adjustments. Variable density yields variation of OC at millimeter level everywhere, while gravity anomaly gradient introduces variation of OC of greater than 10 cm at higher elevations, suggesting that these quantities must be considered in OC. The modified Mader method is recommended for computing OC.

  13. Level Densities and Radiative Strength Functions in 56FE and 57FE

    SciTech Connect

    Tavukcu, E

    2002-12-10

    Understanding nuclear level densities and radiative strength functions is important for pure and applied nuclear physics. Recently, the Oslo Cyclotron Group has developed an experimental method to extract level densities and radiative strength functions simultaneously from the primary {gamma} rays after a light-ion reaction. A primary {gamma}-ray spectrum represents the {gamma}-decay probability distribution. The Oslo method is based on the Axel-Brink hypothesis, according to which the primary {gamma}-ray spectrum is proportional to the product of the level density at the final energy and the radiative strength function. The level density and the radiative strength function are fit to the experimental primary {gamma}-ray spectra, and then normalized to known data. The method works well for heavy nuclei. The present measurements extend the Oslo method to the lighter mass nuclei {sup 56}Fe and {sup 57}Fe. The experimental level densities in {sup 56}Fe and {sup 57}Fe reveal step structure. This step structure is a signature for nucleon pair breaking. The predicted pairing gap parameter is in good agreement with the step corresponding to the first pair breaking. Thermodynamic quantities for {sup 56}Fe and {sup 57}Fe are derived within the microcanonical and canonical ensembles using the experimental level densities. Energy-temperature relations are considered using caloric curves and probability density functions. The differences between the thermodynamics of small and large systems are emphasized. The experimental heat capacities are compared with the recent theoretical calculations obtained in the Shell Model Monte Carlo method. Radiative strength functions in {sup 56}Fe and {sup 57}Fe have surprisingly high values at low {gamma}-ray energies. This behavior has not been observed for heavy nuclei, but has been observed in other light- and medium-mass nuclei. The origin of this low {gamma}-ray energy effect remains unknown.

  14. Correlation of vitamin D, bone mineral density and parathyroid hormone levels in adults with low bone density

    PubMed Central

    Kota, Sunil; Jammula, Sruti; Kota, Siva; Meher, Lalit; Modi, Kirtikumar

    2013-01-01

    Background: Bone mineral densiy (BMD) is known to be affected by serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels. Indian data pertinent to above observation is scant. Our study aimed to investigate the relationships between serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels and bone mineral density (BMD) in a cohort of Indian patients. Materials and Methods: Adults with or without fragility fractures with low BMD at the hip or lumbar spine were evaluated clinically along with laboratory investigations. T-scores of the hip and spine were derived from BMD-DEXA (dual-energy X-ray absorptiometry). Multivariate regression models were used to investigate the relationships between serum 25(OH) D, iPTH and BMD. Results: Total of 102 patients (male:female = 38:64) with a mean age of 62.5 ± 6.4 years were included in the study. Forty-four patients had osteopenia. Osteoporosis was present in 58 patients. The mean values for serum 25(OH) D and iPTH levels were 21.3 ± 0.5 ng/ml and 53.1 ± 22.3 pg/ml, respectively. In 84.3% of patients, serum 25(OH) D levels were below 30 ng/ml (Normal = 30-74 ng/ml), confirming vitamin D deficiency. There was no association between 25(OH) D levels and BMD at the hip or lumbar spine (P = 0.473 and 0.353, respectively). Both at the hip and lumbar spine; iPTH levels, male gender, body mass index (BMI) and age were found to be significant predictors of BMD. Patients with higher BMI had significantly lower BMD and T-score. At levels <30 ng/ml, 25(OH) D was negatively associated with iPTH (P = 0.041). Conclusion: Among our cohort of patients with low BMD, no direct relationship between serum 25(OH) D levels and BMD was observed. However, a negative correlation between iPTH and 25(OH) D at serum 25(OH) D concentrations <30 ng/ml. Serum iPTH levels showed a significant negative association with BMD at the hip and lumbar spine. Our findings underscore the critical role of

  15. Population-Level Density Dependence Influences the Origin and Maintenance of Parental Care

    PubMed Central

    Reyes, Elijah; Thrasher, Patsy; Bonsall, Michael B.; Klug, Hope

    2016-01-01

    Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteristics (stage-specific rates of mortality and maturation) and the fitness benefits associated with the origin and the maintenance of parental care for two broad ecological scenarios: the scenario in which egg survival is density dependent and the case in which adult survival is density dependent. Our findings suggest that high offspring need is likely critical in driving the origin, but not the maintenance, of parental care regardless of whether density dependence acts on egg or adult survival. In general, parental care is more likely to result in greater fitness benefits when baseline adult mortality is low if 1) egg survival is density dependent or 2) adult mortality is density dependent and mutant density is relatively high. When density dependence acts on egg mortality, low rates of egg maturation and high egg densities are less likely to lead to strong fitness benefits of care. However, when density dependence acts on adult mortality, high levels of egg maturation and increasing adult densities are less likely to maintain care. Juvenile survival has relatively little, if any, effect on the origin and maintenance of egg-only care. More generally, our results suggest that the evolution of parental care will be influenced by an organism’s entire life history characteristics, the stage at which density dependence acts, and whether care is originating or being maintained. PMID:27093056

  16. Population-Level Density Dependence Influences the Origin and Maintenance of Parental Care.

    PubMed

    Reyes, Elijah; Thrasher, Patsy; Bonsall, Michael B; Klug, Hope

    2016-01-01

    Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteristics (stage-specific rates of mortality and maturation) and the fitness benefits associated with the origin and the maintenance of parental care for two broad ecological scenarios: the scenario in which egg survival is density dependent and the case in which adult survival is density dependent. Our findings suggest that high offspring need is likely critical in driving the origin, but not the maintenance, of parental care regardless of whether density dependence acts on egg or adult survival. In general, parental care is more likely to result in greater fitness benefits when baseline adult mortality is low if 1) egg survival is density dependent or 2) adult mortality is density dependent and mutant density is relatively high. When density dependence acts on egg mortality, low rates of egg maturation and high egg densities are less likely to lead to strong fitness benefits of care. However, when density dependence acts on adult mortality, high levels of egg maturation and increasing adult densities are less likely to maintain care. Juvenile survival has relatively little, if any, effect on the origin and maintenance of egg-only care. More generally, our results suggest that the evolution of parental care will be influenced by an organism's entire life history characteristics, the stage at which density dependence acts, and whether care is originating or being maintained. PMID:27093056

  17. Inconsistencies in the description of pairing effects in nuclear level densities

    NASA Astrophysics Data System (ADS)

    Schmidt, Karl-Heinz; Jurado, Beatriz

    2012-10-01

    Pairing correlations have a strong influence on nuclear level densities. Empirical descriptions and theoretical models have been developed to take these effects into account. The present article discusses cases, where descriptions of nuclear level densities are inconsistent or in conflict with the present understanding of nuclear properties. Phenomenological approaches consider an energy-shift parameter. However, the absolute magnitude of the energy shift, which actually corresponds to the pairing condensation energy, is generally not compatible with the observation that stable pairing correlations are present in essentially all nuclei. It is also shown that in the BCS model pairing condensation energies and critical pairing energies are inconsistent for light nuclei. A modification to the composite Gilbert-Cameron level-density description is proposed, and the use of more realistic pairing theories is suggested.

  18. Nuclear level densities of 64,66Zn from neutron evaporation

    NASA Astrophysics Data System (ADS)

    Ramirez, Anthony Paul; Voinov, Alexander; Grimes, Steven; Brune, Carl; Massey, Thomas

    2013-10-01

    The neutron spectra from the reactions 63Cu(d,n)64Zn and 65Cu(d,n)66Zn have been measured at deuteron beam energies of 6 and 7.5 MeV. Level densities of the residual nuclei 64Zn and 66Zn were extracted and compared with different level density models: (1) Gilbert-Cameron model, (2) Backshifted Fermi gas model using the Egidy systematics, and (3) microscopic combinatorial level densities. We found that the Gilbert-Cameron model closely agrees with the experimental results. We have also studied the non-compound component of the reactions from the neutron angular distributions. The non-compound component has been shown to be dominant in forward angles and is more pronounced at high neutron emission energies. We have also observed a slight enhancement of the non-compound contribution as the incident deuteron energy is increased.

  19. Level densities of heavy nuclei in the shell model Monte Carlo approach

    NASA Astrophysics Data System (ADS)

    Alhassid, Y.; Bertsch, G. F.; Gilbreth, C. N.; Nakada, H.; Özen, C.

    2016-06-01

    Nuclear level densities are necessary input to the Hauser-Feshbach theory of compound nuclear reactions. However, the microscopic calculation of level densities in the presence of correlations is a challenging many-body problem. The configurationinteraction shell model provides a suitable framework for the inclusion of correlations and shell effects, but the large dimensionality of the many-particle model space has limited its application in heavy nuclei. The shell model Monte Carlo method enables calculations in spaces that are many orders of magnitude larger than spaces that can be treated by conventional diagonalization methods and has proven to be a powerful tool in the microscopic calculation of level densities. We discuss recent applications of the method in heavy nuclei.

  20. Level densities of iron isotopes and lower-energy enhancement of y-strength function

    SciTech Connect

    Voinov, A V; Grimes, S M; Agvaanluvsan, U; Algin, E; Belgya, T; Brune, C R; Guttormsen, M; Hornish, M J; Massey, T N; Mitchell, G; Rekstad, J; Schiller, A; Siem, S

    2005-08-30

    The neutron spectrum from the {sup 55}Mn(d,n){sup 56}Fe reaction has been measured at E{sub d} = 7 MeV. The level density of {sup 56}Fe obtained from neutron evaporation spectrum has been compared to the level density from Oslo-type {sup 57}Fe({sup 3}He, a{gamma}){sup 56}Fe experiment [1]. The good agreement supports the recent results [1, 8] including an availability of a low-energy enhancement in the {gamma}-strength function for iron isotopes. The new level density function allowed us to investigate an excitation energy dependence of this enhancement, which is shown to increase with increasing excitation energy.

  1. Competing quantum Hall phases in the second Landau level in low density limit

    NASA Astrophysics Data System (ADS)

    Pan, Wei; Serafin, A.; Xia, J. S.; Yin, L.; Sullivan, N. S.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

    2015-03-01

    We present here the results from two high quality, low density GaAs quantum wells. In sample A of electron density n = 5.0 x 1010 cm-2, anisotropic electronic transport behavior was observed at ν = 7/2 in the second Landau level. We believe that the anisotropy is due to the large Landau level mixing effect in this sample. In sample B of density 4.1 x 1010 cm-2, strong 8/3, 5/2, and 7/3 fractional quantum Hall states were observed. Furthermore, our energy gap data obtained in various samples of different densities suggest that the 5/2 state may be spin unpolarized in the low density limit. The results from both samples show that the strong electron-electron interactions and a large Landau level mixing effect play an import role in the competing ground states in the second landau level. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

  2. Nuclear level density and γ-ray strength function of 43Sc

    NASA Astrophysics Data System (ADS)

    Bürger, A.; Larsen, A. C.; Hilaire, S.; Guttormsen, M.; Harissopulos, S.; Kmiecik, M.; Konstantinopoulos, T.; Krtička, M.; Lagoyannis, A.; Lönnroth, T.; Mazurek, K.; Norrby, M.; Nyhus, H. T.; Perdikakis, G.; Siem, S.; Spyrou, A.; Syed, N. U. H.

    2012-06-01

    The nuclear level density and the γ-ray strength function have been determined for 43Sc in the energy range up to 2 MeV below the neutron separation energy using the Oslo method with the 46Ti(p,α)43Sc reaction. A comparison to 45Sc shows that the level density of 43Sc is smaller by an approximately constant factor of two. This behavior is well reproduced in a microscopic, combinatorial model calculation. The γ-ray strength function increases at low γ-ray energies, a feature which has been observed in several nuclei but which still awaits theoretical explanation.

  3. Experimental Study of Level Density and {gamma}-strength Functions from Compound Nuclear Reactions

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Massey, T. N.; Schiller, A.; Guttormsen, M.; Siem, S.

    2008-04-17

    The current status of experimental study of level density and {gamma}-strength functions is reviewed. Three experimental techniques are used. These are measurements of particle evaporation spectra from compound nuclear reactions, the measurements of particle-{gamma} coincidences from inelastic scattering and pick-up reactions and the method of two-step {gamma}-cascades following neutron/proton radiative capture. Recent experimental data on level densities from neutron evaporation spectra are shown. The first results on the cascade {gamma}-spectrum from the {sup 59}Co(p,2{gamma}){sup 60}Ni reaction are presented.

  4. BA11 FKBP5 expression levels correlate with dendritic spine density in postmortem PTSD and controls

    PubMed Central

    Young, Keith A.; Thompson, Peter M.; Cruz, Dianne A.; Williamson, Douglas E.; Selemon, Lynn D.

    2015-01-01

    Genetic variants of the immunophilin FKBP5 have been implicated in susceptibility to post-traumatic stress disorder (PTSD) and other stress-related disorders. We examined the relationship between mushroom, stubby, thin and filopodial spine densities measured with Golgi staining and FKBP5 gene expression in the medial orbitofrontal cortex (BA11) in individuals diagnosed with PTSD and normal controls (n = 8/8). ANCOVA revealed PTSD cases had a significantly elevated density of stubby spines (29%, P < 0.037) and a trend for a reduction in mushroom spine density (25%, p < 0.082). Levels of FKBP5 mRNA were marginally elevated in the PTSD cases (z = 1.94, p = 0.053) and levels correlated inversely with mushroom (Spearman's rho = −0.83, p < 0.001) and overall spine density (rho = −0.75, p < 0.002) and directly with stubby spine density (rho = 0.55, p < 0.027). These data suggest that FKBP5 may participate in a cellular pathway modulating neuronal spine density changes in the brain, and that this pathway may be dysregulated in PTSD. PMID:26844242

  5. Level Density of COBALT-57 in the Energy Region 1 Mev to 14 Mev

    NASA Astrophysics Data System (ADS)

    Mishra, Vivek

    The level density of ^{57 }Co is studied in the energy region of 1-14 MeV using three experimental techniques. Levels are counted in the resolved region, evaporation spectra are measured in the resolved to continuum region, and the coherence width is measured in the region of level overlap. Use of Hauser-Feshbach fits to the evaporation cross sections requires level densities of the residual nucleus. A two -parameter based Fermi gas form is used for the calculation of level density as a function of the nuclear excitation energy. This procedure enables level density calculation beyond the energy region in which the two fixed parameters provide the best fits to the data. A comparison is made between the level density obtained from the above described methods and the predictions of the microscopic model in an energy range of 1-20 MeV. This model utilizes a BCS pairing Hamiltonian and specific sets of single particle states and calculates numerical values of the level density. Comparisons are also made with level density of ^{57 }Co obtained in various other studies. Both the resolved level studies and the fits to the evaporation spectra were conducted using the ^{56}Fe(d,n)^{57 }Co and ^{57}Fe(p,n) ^{57}Co reactions. Standard neutron time-of-flight techniques including pulse shape discrimination for elimination of gamma -rays were employed. An energy resolution as good as 6 keV at 1-1.5 MeV neutron energy was obtained for high resolution measurements. For Ericson fluctuation measurements, the excitation functions corresponding to the ground state and the first two excited states of the residual nucleus in the ^{56}Fe(p,n) ^{56}Co reaction were obtained for lab angles between 0^circ and 150^circ. The ^{56}Fe(d,n) ^{57}Co reaction proves to be very selective in populating resolved states and includes substantial contributions from mechanisms other than the compound nuclear. The ^{57 }Fe(p,n)^{57}Co reaction populated 14 previously unknown levels. The fits to the

  6. Salt tolerance and stress level affect plant biomass-density relationships and neighbor effects

    NASA Astrophysics Data System (ADS)

    Yu, Zhenxing; Chen, Wenwen; Zhang, Qian; Yang, Haishui; Tang, Jianjun; Weiner, Jacob; Chen, Xin

    2014-07-01

    It has been shown that plant biomass-density relationships are altered under extreme or stressed conditions. We do not know whether variation in biomass-density relationships is a direct result of stress tolerance or occurs via changes in plant-plant interactions. Here, we evaluated biomass-density relationships and neighbor effects in six plant species that differ in salt tolerance in a salt marsh, and conducted a literature review of biomass-density relationship under higher and lower stress levels. Our field study showed that both neighbor effects and the exponent of the biomass-density relationship (α) varied among plant species with different degrees of salt tolerance. There was a positive relationship between neighbor effects (measured as relative interaction index) and α-value among the tested species. The literature review showed that α and its variation increased under higher stress. Our results indicate that plant species with different salinity tolerance differ in the direction and strength of neighbor effects, resulting in variation in biomass-density relationships. Our results support the hypothesis that differences in biomass-density relationships among species are not due to differences in stress tolerance alone, they are mediated by changes in plant-plant interactions.

  7. Level densities and radiative strength functions in ^116,117Sn

    NASA Astrophysics Data System (ADS)

    Agvaanluvsan, U.; Mitchell, G. E.; Chankova, R.; Guttormsen, M.; Sunde, A.-C.; Becker, J. A.; Bernstein, L. A.; Schiller, A.; Voinov, A.

    2003-10-01

    Level densities and radiative strength functions are important for understanding nuclear properties in general, for an accurate knowledge of nuclear reaction rates in particular. A recently developed method to extract level densities and radiative strength functions from ^3He induced reactions is applied to ^117Sn. Level densities and radiative strength functions in ^116,117Sn from ground state up to the neutron binding energy are obtained from ^3He and α channels. Spectra of the first γ-rays emitted from each excitation energy bin are obtained via sequential extraction. The emission probability of these γ-rays is proportional to the product of the radiative strength function and the final state level density. This so-called Oslo method has been applied extensively to rare-earth nuclei. The method has also been applied to lighter nuclei such as Fe and Mo. The measurement of ^116,117Sn is intended to provide information on nuclei intermediate between the lighter and heavier nuclei that show quite different behavior.

  8. Level densities and γ-ray strength functions in Sn isotopes

    NASA Astrophysics Data System (ADS)

    Toft, H. K.; Larsen, A. C.; Agvaanluvsan, U.; Bürger, A.; Guttormsen, M.; Mitchell, G. E.; Nyhus, H. T.; Schiller, A.; Siem, S.; Syed, N. U. H.; Voinov, A.

    2010-06-01

    The nuclear level densities of Sn118,119 and the γ-ray strength functions of Sn116,118,119 below the neutron separation energy are extracted with the Oslo method using the (He3,αγ) and (He3,He3'γ) reactions. The level-density function of Sn119 displays steplike structures. The microcanonical entropies are deduced from the level densities, and the single neutron entropy of Sn119 is determined to be 1.7 ± 0.2 kB. Results from a combinatorial model support the interpretation that some of the low-energy steps in the level density function are caused by neutron pair breaking. An enhancement in all the γ-ray strength functions of Sn116-119, compared to standard models for radiative strength, is observed for the γ-ray energy region of ≃4-11 MeV. These small resonances all have a centroid energy of 8.0(1) MeV and an integrated strength corresponding to 1.7(9)% of the classical Thomas-Reiche-Kuhn sum rule. The Sn resonances may be due to electric dipole neutron skin oscillations or to an enhancement of the giant magnetic dipole resonance.

  9. Serum Dickkopf-1 Level in Postmenopausal Females: Correlation with Bone Mineral Density and Serum Biochemical Markers

    PubMed Central

    Fouda, Neveen; Abbas, Amal Ahmed

    2013-01-01

    Objective. To assess serum level of Dickkopf-1 in postmenopausal females and its correlation with bone mineral density and serum biochemical markers. Methods. Bone densitometry, serum Dickkopf-1, calcium, phosphorus, and alkaline phosphatase were done in sixty postmenopausal females. Patients were divided according to T score into osteoporosis (group I), osteopenia (group II), and normal bone mineral density that served as controls. Results. There was highly significant increase in serum Dickkopf-1 levels in postmenopausal females with abnormal T score versus controls (P < 0.001). Serum DKK-1 levels correlated negatively with both lumbar T score (r = −0.69, P < 0.001) and femur T score (r = −0.64, P < 0.001) and correlated positively with duration of menopause (r = 0.61, P < 0.001), while there was no significant correlation between serum levels of either calcium, phosphorus or alkaline phosphatase, and both serum Dickkopf-1 levels and the level of bone mineral density (P > 0.05). Conclusion. Postmenopausal females may suffer from osteoporosis as evidenced by bone densitometry. Postmenopausal women with significantly increased serum Dickkopf-1 had more significant osteoporosis. Prolonged duration of menopause and increased serum Dickkopf-1 are important risk factors for the development and severity of osteoporosis. PMID:23878759

  10. Considerations for CBI Screen Design with Respect to Text Density Levels in Content Learning from an Integrated Perspective.

    ERIC Educational Resources Information Center

    Ipek, Ismail

    This paper examines variations of text density levels for learning in a computer-based instruction (CBI) tutorial from an integrated perspective, and addresses the following questions: (1) What is the text density? (2) What are the relationships among text density approaches? and (3) What are the contributions of text density for learning and how…

  11. A method for estimating the height of a mesospheric density level using meteor radar

    NASA Astrophysics Data System (ADS)

    Younger, J. P.; Reid, I. M.; Vincent, R. A.; Murphy, D. J.

    2015-07-01

    A new technique for determining the height of a constant density surface at altitudes of 78-85 km is presented. The first results are derived from a decade of observations by a meteor radar located at Davis Station in Antarctica and are compared with observations from the Microwave Limb Sounder instrument aboard the Aura satellite. The density of the neutral atmosphere in the mesosphere/lower thermosphere region around 70-110 km is an essential parameter for interpreting airglow-derived atmospheric temperatures, planning atmospheric entry maneuvers of returning spacecraft, and understanding the response of climate to different stimuli. This region is not well characterized, however, due to inaccessibility combined with a lack of consistent strong atmospheric radar scattering mechanisms. Recent advances in the analysis of detection records from high-performance meteor radars provide new opportunities to obtain atmospheric density estimates at high time resolutions in the MLT region using the durations and heights of faint radar echoes from meteor trails. Previous studies have indicated that the expected increase in underdense meteor radar echo decay times with decreasing altitude is reversed in the lower part of the meteor ablation region due to the neutralization of meteor plasma. The height at which the gradient of meteor echo decay times reverses is found to occur at a fixed atmospheric density. Thus, the gradient reversal height of meteor radar diffusion coefficient profiles can be used to infer the height of a constant density level, enabling the observation of mesospheric density variations using meteor radar.

  12. The novel measurement method of liquid level and density in airtight container

    NASA Astrophysics Data System (ADS)

    Niu, Zhe; Zhao, Yulong; Tian, Bian; Guo, Fangfang

    2012-12-01

    This paper describes a novel method of liquid level and density measurement with application in airtight container such as oil storage tank. In order to prove the method, a multifunctional pressure-type liquidometer (MPTL) was designed. The MPTL comprises two pressure sensors for capturing the underwater pressure accurately, by which the MPTL could calculate the density of the liquid and back-calculate the level of the liquid. A digital temperature sensor was implanted in the MPTL to collect the temperature of the liquid. Series of experiments show a favorable linearity of 0.2% and a high accuracy of 0.27%. Besides, the simple fabrication, low cost and unconstrained conditions guarantee its popularity in the petrochemical industry fields. Overall, the findings of this study confirm the feasibility of the novel liquid level measure method and offer an economical scheme for mass producing.

  13. Spectral density of Cooper pairs in two level quantum dot-superconductors Josephson junction

    NASA Astrophysics Data System (ADS)

    Dhyani, A.; Rawat, P. S.; Tewari, B. S.

    2016-09-01

    In the present paper, we report the role of quantum dot energy levels on the electronic spectral density for a two level quantum dot coupled to s-wave superconducting leads. The theoretical arguments in this work are based on the Anderson model so that it necessarily includes dot energies, single particle tunneling and superconducting order parameter for BCS superconductors. The expression for single particle spectral function is obtained by using the Green's function equation of motion technique. On the basis of numerical computation of spectral function of superconducting leads, it has been found that the charge transfer across such junctions can be controlled by the positions and availability of the dot levels.

  14. Level densities and spin cutoff parameters for 60Co and 62Ni from proton evaporation spectra

    NASA Astrophysics Data System (ADS)

    Voinov, Alexander; Grimes, Steven; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann Cecilie; Massey, Tomas; Siem, Sunniva

    2013-10-01

    Prediction of reaction cross sections remains a major problem in applications such as data evaluations or/and astrophysics reaction rate calculations. There is big progress in the development of nuclear reaction codes which now include different reaction mechanisms. However, these codes use many input parameters. The variety of input parameters helps us to describe existing experimental data but it creates problems when it comes to predictions. The uncertainties of the level density and the spin cutoff parameter cause the major concern. The proton spectra from α and lithium induced reactions have been measured and analyzed with the Hauser-Feshbach model. Different input level density models have been tested. The level densities and spin cutoff parameters were obtained with Monte-Carlo technique taking into account known spins of discrete low-lying levels of residual nuclei. It was found that the best description is achieved with the Gilbert and Cameron model functions. Excitation energy dependence of spin cutoff parameters was found to be different for 60Co and 62Ni nuclei. It is inconsistent with Fermi-gas model which is usually used to calculate spin cutoff parameters.

  15. Level scheme of /sup 148/Pm and the s-process neutron density

    SciTech Connect

    Lesko, K.T.; Norman, E.B.; Larimer, R.; Bacelar, J.C.; Beck, E.M.

    1989-02-01

    A level scheme of /sup 148/Pm up to 800 keV is deduced from gamma-ray coincidence data and published particle transfer data. Approximately 106 gamma-ray transitions have been placed between 36 levels. We have identified three levels below 500 keV in excitation which decay to both the ground state and to the isomeric level at 137 keV. The presence of these levels guarantees that /sup 148/Pm/sup g//sup ,//sup m/ are in thermal equilibrium during the s process. The s-process neutron density inferred from the branch point at /sup 148/Pm is deduced to be 3 x 10/sup 8//cm/sup 3/.

  16. Fermi-level pinning through defects at GaAs/oxide interfaces: A density functional study

    NASA Astrophysics Data System (ADS)

    Colleoni, Davide; Miceli, Giacomo; Pasquarello, Alfredo

    2015-09-01

    Using density functional calculations, we study a set of candidate defects for Fermi-level pinning at GaAs/oxide interfaces. The set of considered defects comprises both bulklike and interfacial defects, including As antisites, Ga and As dangling bonds, the As-As dimer/dangling bond defect, and several defect complexes. The defects are generated within atomistic model structures representing the GaAs /Al2O3 interface. Formation energies of bulklike defects are obtained and compared with those of corresponding bulk defects, while interfacial defects are studied through their relative defect energies. Finite-size corrections to the defect energies are applied through a scheme that accounts for the interfacial geometry of our models. Defect levels are defined as thermodynamic transition levels between different charge states and are calculated for all considered defects. Through an alignment procedure based on hybrid functional calculations, the defect levels are then positioned within the calculated band gap of GaAs that reproduces the experimental one, thereby enabling direct comparisons with the experimental density of defect states. Our study shows that several As-related defects show a similar amphoteric bistability between an As-As dimer state and a configuration with two doubly occupied As dangling bonds. The associated charge transition levels generally lie in the midgap region, in accord with experimental observations. This mechanism is proposed as the origin of the observed Fermi-level pinning at GaAs/oxide interfaces.

  17. Nuclear level densities of 64,66Zn from neutron evaporation

    NASA Astrophysics Data System (ADS)

    Ramirez, A. P. D.; Voinov, A. V.; Grimes, S. M.; Schiller, A.; Brune, C. R.; Massey, T. N.; Salas-Bacci, A.

    2013-12-01

    Double differential cross sections of neutrons from d+63,65Cu reactions have been measured at deuteron energies of 6 and 7.5 MeV. The cross sections measured at backward angles have been compared to theoretical calculations in the framework of the statistical Hauser-Feshbach model. Three different level density models were tested: the Fermi-gas model, the Gilbert-Cameron model, and the microscopic approach through the Hartree-Fock-Bogoliubov method (HFBM). The calculations using the Gilbert-Cameron model are in best agreement with our experimental data. Level densities of the residual nuclei 64Zn and 66Zn have been obtained from statistical neutron evaporation spectra. The angle-integrated cross sections have been analyzed with the exciton model of nuclear reaction.

  18. Shell energy and the level-density parameter of hot nuclei

    SciTech Connect

    Nerlo-Pomorska, Bozena; Pomorski, Krzysztof; Bartel, Johann

    2006-09-15

    Macroscopic-microscopic calculations have been performed with the Yukawa folded mean field for 134 spherical even-even nuclei and 6 deformed ones at temperatures 0{<=}T{<=}5 MeV and elongations ranging from oblate shapes to the scission configuration of fissioning nuclei. The Strutinsky type free-energy shell corrections for this sample of nuclei and their temperature and deformation dependence are found by a folding procedure in particle-number space. The average dependence of the single-particle level-density parameter on mass number A and isospin I is determined and compared with previous estimates obtained using the relativistic mean-field theory, the Hartree-Fock approximation with the Skyrme effective interaction, and the phenomenological Thomas-Fermi approach adjusted to experimental data. The estimates for the level-density parameter obtained for different deformations are fitted by a liquid-drop type expression.

  19. Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes

    PubMed Central

    Bennell, Kim L; Brukner, Peter D; Malcolm, Susan A

    1996-01-01

    The effect of intense physical activity on female reproductive hormones is well recognised1–3 and there is evidence that menstrual disturbances associated with hypo-oestrogenism adversely affect bone density especially at the lumbar spine.4 5 Physical activity can also have a range of effects on male reproductive function depending upon the intensity and duration of the activity and the fitness of the individual.6 In particular, endurance training may be associated with reductions in circulating testosterone levels. Since testosterone has important anabolic roles, alterations in reproductive hormone profiles may have detrimental skeletal consequences similar to those seen in females with menstrual disturbances. The aim of this brief review is to present the limited literature on the relation between bone density and testosterone levels in male endurance athletes. PMID:8889111

  20. Nuclear level densities of 64,66 Zn from neutron evaporation

    DOE PAGESBeta

    Ramirez, A. P. D.; Voinov, A. V.; Grimes, S. M.; Schiller, A.; Brune, C. R.; Massey, T. N.; Salas-Bacci, A.

    2013-12-26

    Double differential cross sections of neutrons from d+63,65Cu reactions have been measured at deuteron energies of 6 and 7.5 MeV. The cross sections measured at backward angles have been compared to theoretical calculations in the framework of the statistical Hauser-Feshbach model. Three different level density models were tested: the Fermi-gas model, the Gilbert-Cameron model, and the microscopic approach through the Hartree-Fock-Bogoliubov method (HFBM). The calculations using the Gilbert-Cameron model are in best agreement with our experimental data. Level densities of the residual nuclei 64Zn and 66Zn have been obtained from statistical neutron evaporation spectra. In conclusion, the angle-integrated cross sectionsmore » have been analyzed with the exciton model of nuclear reaction.« less

  1. Stochastic estimation of level density in nuclear shell-model calculations

    NASA Astrophysics Data System (ADS)

    Shimizu, Noritaka; Utsuno, Yutaka; Futamura, Yasunori; Sakurai, Tetsuya; Mizusaki, Takahiro; Otsuka, Takaharu

    2016-06-01

    An estimation method of the nuclear level density stochastically based on nuclear shell-model calculations is introduced. In order to count the number of the eigen-values of the shell-model Hamiltonian matrix, we perform the contour integral of the matrix element of a resolvent. The shifted block Krylov subspace method enables us its efficient computation. Utilizing this method, the contamination of center-of-mass motion is clearly removed.

  2. Level Densities of Residual Nuclei from particle evaporation of {sup 64}Cu

    SciTech Connect

    Oginni, B. M.; Grimes, S. M.; Voinov, A. V.; Adekola, A. S.; Brune, C. R.; Carter, D.; Heinen, Z.; Jacobs, D.; Massey, T. N.; O'Donnell, J.

    2009-07-06

    The reactions of {sup 6}Li on {sup 58}Fe and {sup 7}Li on {sup 57}Fe have been studied at beam energy 15 MeV. These two reactions produce the same compound nucleus, {sup 64}Cu. The neutron, proton, and alpha spectra were measured at backward angles. The data obtained have been compared with Hauser Fesh-bach model calculations. The level density parameters of the residual nuclei have been obtained from the particle evaporation spectra.

  3. Conditions for observation of fade out of collective enhancement of the nuclear level density

    SciTech Connect

    Grimes, S. M.

    2008-11-15

    The results of two recent papers searching for the disappearance of collective enhancements with energy in nuclear level densities are examined. It is found that the effects of such enhancements are less than has been assumed. The reduction in the size of the effect only partially resolves the disagreement between theory and experiment. This effect also plays a role in explaining the results of an earlier experiment.

  4. The role of seniority-zero states in nuclear level densities

    NASA Astrophysics Data System (ADS)

    Åberg, S.; Carlsson, B. G.; Døssing, Th.; Möller, P.

    2015-09-01

    At low excitation energies seniority-zero states dominate the level density of K = 0 bands in deformed even-even nuclei, while they play no role at higher excitation energies. We describe the level densities in a Fermi-gas model as well as in a combinatorial level-density model and compare to detailed experimental data for some rare-earth nuclei. An explanation is provided for recent observations of an odd-even staggering in the spin-distribution function as an effect of r-symmetry of wave functions for deformed nuclei. The structure of 0+ states in deformed nuclei is discussed in the model and compared to data, stressing the role of the seniority quantum number. The Fermi-gas model is utilized to obtain an overview of the odd-even staggering phenomenon in other mass regions. Odd-even staggering in spherical nuclei, appearing in open-shell nuclei, is briefly discussed as caused by fermion exchange symmetry.

  5. Ocean Turbulence V: Mesoscale Modeling in Level Coordinates. The Effect of Random Nature of Density

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.; Dubovikov, M. S.

    1998-01-01

    The main result of this paper is the derivation of a new expression for the tracer subgrid term in level coordinates S(l) to be employed in O-GCM. The novel feature is the proper account of the random nature of the density field which strongly affects the transformation from isopycnal to level coordinates of the variables of interest, velocity and tracer fields, their correlation functions and ultimately the subgrid terms. In deriving our result we made use of measured properties of vertical ocean turbulence. The major new results are: 1) the new subgrid expression is different from that of the heuristic GM model, 2) u++(tracer)=1/2u+(thickness), where u++ and u+ are the tracer and thickness bolus velocities. In previous models, u++ = u+, 2) the subgrid for a tracer tau is not the same as that for the density rho even when one accounts for the obvious absence of a diffusion term in the latter. The difference stems from a new treatment of the stochastic nature of the density, 3) the mesoscale diffusivity enters both locally and non-locally, as the integral over all z's from the bottom of the ocean to the level z.

  6. Level density inputs in nuclear reaction codes and the role of the spin cutoff parameter

    DOE PAGESBeta

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Burger, A.; Gorgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2014-09-03

    Here, the proton spectrum from the 57Fe(α,p) reaction has been measured and analyzed with the Hauser-Feshbach model of nuclear reactions. Different input level density models have been tested. It was found that the best description is achieved with either Fermi-gas or constant temperature model functions obtained by fitting them to neutron resonance spacing and to discrete levels and using the spin cutoff parameter with much weaker excitation energy dependence than it is predicted by the Fermi-gas model.

  7. Level density inputs in nuclear reaction codes and the role of the spin cutoff parameter

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Burger, A.; Gorgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2014-09-03

    Here, the proton spectrum from the 57Fe(α,p) reaction has been measured and analyzed with the Hauser-Feshbach model of nuclear reactions. Different input level density models have been tested. It was found that the best description is achieved with either Fermi-gas or constant temperature model functions obtained by fitting them to neutron resonance spacing and to discrete levels and using the spin cutoff parameter with much weaker excitation energy dependence than it is predicted by the Fermi-gas model.

  8. Level Density Inputs in Nuclear Reaction Codes and the Role of the Spin Cutoff Parameter

    NASA Astrophysics Data System (ADS)

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2014-05-01

    The proton spectrum from the 57Fe(α, p) reaction has been measured and analyzed with the Hauser-Feshbach model of nuclear reactions. Different input level density models have been tested. It was found that the best description is achieved with either Fermi-gas or constant temperature model functions obtained by fitting them to neutron resonance spacings and to discrete levels and using the spin cutoff parameter with much a weaker excitation energy dependence than predicted by the Fermi-gas model.

  9. Assessment of thermal comfort level at pedestrian level in high-density urban area of Hong Kong

    NASA Astrophysics Data System (ADS)

    Ma, J.; Ng, E.; Yuan, C.; Lai, A.

    2015-12-01

    Hong Kong is a subtropical city which is very hot and humid in the summer. Pedestrians commonly experience thermal discomfort. Various studies have shown that the tall bulky buildings intensify the urban heat island effect and reduce urban air ventilation. However, relatively few studies have focused on modeling the thermal load at pedestrian level (~ 2 m). This study assesses the thermal comfort level, quantified by PET (Physiological Equivalent Temperature), using a GIS - based simulation approach. A thermal comfort level map shows the PET value of a typical summer afternoon in the high building density area. For example, the averaged PET in Sheung Wan is about 41 degree Celsius in a clear day and 38 degree Celsius in a cloudy day. This map shows where the walkways, colonnades, and greening is most needed. In addition, given a start point, a end point, and weather data, we generate the most comfort walking routes weighted by the PET. In the simulation, shortwave irradiance is calculated using the topographic radiation model (Fu and Rich, 1999) under various cloud cover scenarios; longwave irradiance is calculated based the radiative transfer equation (Swinbank, 1963). Combining these two factors, Tmrt (mean radiant temperature) is solved. And in some cases, the Tmrt differ more than 40 degree Celsius between areas under the sun and under the shades. Considering thermal load and wind information, we found that shading from buildings has stronger effect on PET than poor air ventilation resulted from dense buildings. We predict that pedestrians would feel more comfortable (lower PET) in a hot summer afternoon when walking in the higher building density area.

  10. Measurements of population densities of metastable and resonant levels of argon using laser induced fluorescence

    SciTech Connect

    Nikolić, M.; Newton, J.; Sukenik, C. I.; Vušković, L.; Popović, S.

    2015-01-14

    We present a new approach to measure population densities of Ar I metastable and resonant excited states in low temperature Ar plasmas at pressures higher than 1 Torr. This approach combines the time resolved laser induced fluorescence technique with the kinetic model of Ar. The kinetic model of Ar is based on calculating the population rates of metastable and resonant levels by including contributions from the processes that affect population densities of Ar I excited states. In particular, we included collisional quenching processes between atoms in the ground state and excited states, since we are investigating plasma at higher pressures. We also determined time resolved population densities of Ar I 2 p excited states by employing optical emission spectroscopy technique. Time resolved Ar I excited state populations are presented for the case of the post-discharge of the supersonic flowing microwave discharge at pressures of 1.7 and 2.3 Torr. The experimental set-up consists of a pulsed tunable dye laser operating in the near infrared region and a cylindrical resonance cavity operating in TE{sub 111} mode at 2.45 GHz. Results show that time resolved population densities of Ar I metastable and resonant states oscillate with twice the frequency of the discharge.

  11. Endurance training associated with slightly lowered serum estradiol levels decreases mineral density of canine skeleton.

    PubMed

    Puustjärvi, K; Karjalainen, P; Nieminen, J; Arokoski, J; Parviainen, M; Helminen, H J; Soimakallio, S

    1992-06-01

    The effects of long-term running exercise were studied in 20 beagle dogs. A total of 10 dogs ran from the age of 15 weeks to the age of 70 weeks in a progressive program for up to 40 km/day. A total of 10 sister dogs spent the study period in individual cages. When the dogs were 70 weeks old, bone mineral density of the vertebrae, hip, and radius was analyzed by dual-energy x-ray absorptiometry (DEXA; Lunar) and the vertebrae were also assessed by quantitative computed tomography (QCT; Siemens DR 1). Mineral density was lower in the running dogs than in the controls. The difference was greatest in the spine in the QCT analysis. Blood chemistry analyses revealed that the metabolism of the bone was significantly accelerated. The estradiol levels showed the trend to be reduced in the running group. The beneficial effect of exercise on mineral density has been shown in many earlier studies. However, in this study we demonstrate the possibility of adverse effects of long-term exercise on bone tissue. The change was associated with a decrease of serum estradiol level. PMID:1414479

  12. Excited-state quantum phase transitions in systems with two degrees of freedom: Level density, level dynamics, thermal properties

    SciTech Connect

    Stránský, Pavel; Macek, Michal; Cejnar, Pavel

    2014-06-15

    Quantum systems with a finite number of freedom degrees f develop robust singularities in the energy spectrum of excited states as the system’s size increases to infinity. We analyze the general form of these singularities for low f, particularly f=2, clarifying the relation to classical stationary points of the corresponding potential. Signatures in the smoothed energy dependence of the quantum state density and in the flow of energy levels with an arbitrary control parameter are described along with the relevant thermodynamical consequences. The general analysis is illustrated with specific examples of excited-state singularities accompanying the first-order quantum phase transition. -- Highlights: •ESQPTs found in infinite-size limit of systems with low numbers of freedom degrees f. •ESQPTs related to non-analytical evolutions of classical phase–space properties. •ESQPT signatures analyzed for general f, particularly f=2, extending known case f=1. •ESQPT signatures identified in smoothened density and flow of energy spectrum. •ESQPTs shown to induce a new type of thermodynamic anomalies.

  13. Noninvasive method for determining the liquid level and density inside of a container

    DOEpatents

    Sinha, Dipen N.

    2000-01-01

    Noninvasive method for determining the liquid level and density inside of a container having arbitrary dimension and shape. By generating a flexural acoustic wave in the container shell and measuring the phase difference of the detected flexural wave from that of the originally generated wave a small distance from the generated wave, while moving the generation and detection means through the liquid/vapor interface, this interface can be detected. Both the wave generation and wave detection may be achieved by transducers on the surface of the container. A change in the phase difference over the outer surface of the vessel signifies that a liquid/vapor interface has been crossed, while the magnitude of the phase difference can be related to fluid density immediately opposite the measurement position on the surface of the vessel.

  14. Characteristics of High-density Lipoprotein Subclasses Distribution for Subjects with Desirable Total Cholesterol Levels

    PubMed Central

    2011-01-01

    Background To investigate alteration of high density lipoproteins (HDL) subclasses distribution in different total cholesterol (TC) levels, mainly the characteristics of HDL subclasses distribution in desirable TC levels and analyze the related mechanisms. Methods ApoA-I contents of plasma HDL subclasses were determined by 2-dimensional gel electrophoresis coupled with immunodetection. 486 Chinese Adults subjects were assigned to different TC groups according to the third Report of NCEP (ATP- III) guidelines. Results The increase in contents of small preβ1-HDL, HDL3c, HDL3b, and HDL3a particles clustered and reduce in HDL2b with increased of TC. The distribution of HDL subclasses have shown abnormality characterized by the lower HDL2b (324.2 mg/L) contents and the higher preβ1-HDL (90.4 mg/L) contents for desirable TC Chinese subjects. Among 176 desirable TC subjects, 58.6% subjects with triglyceride (TG) < 2.26 mmol/L, 61.2% subjects with HDL-C ≥1.03 mmol/L and 88.6% subjects with low density lipoprotein cholesterol(LDL-C) < 3.34 mmol/L, and the profile of HDL subclasses distribution for above these subjects was reasonable. Conclusions The particles size of HDL subclasses shifted towards smaller with increased TC levels. The TC was liner with HDL2b contents and those can be reduced 17 mg/L for 0.5 mmol/L increment in TC levels. The HDL subclasses distribution phenotype was not expectation for Chinese Population with desirable TC levels. Thus, from the HDL subclasses distribution point, when assessing the coronary heart disease(CHD) risk not only rely on the TC levels, but also the concentrations of TG, HDL-C and LDL-C must considered in case the potential risk for desirable TC subjects with other plasma lipids metabolism disorders. PMID:21513524

  15. A high-performance Fortran code to calculate spin- and parity-dependent nuclear level densities

    NASA Astrophysics Data System (ADS)

    Sen'kov, R. A.; Horoi, M.; Zelevinsky, V. G.

    2013-01-01

    A high-performance Fortran code is developed to calculate the spin- and parity-dependent shell model nuclear level densities. The algorithm is based on the extension of methods of statistical spectroscopy and implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The proton-neutron formalism is used. We have applied the method for calculating the level densities for a set of nuclei in the sd-, pf-, and pf+g- model spaces. Examples of the calculations for 28Si (in the sd-model space) and 64Ge (in the pf+g-model space) are presented. To illustrate the power of the method we estimate the ground state energy of 64Ge in the larger model space pf+g, which is not accessible to direct shell model diagonalization due to the prohibitively large dimension, by comparing with the nuclear level densities at low excitation energy calculated in the smaller model space pf. Program summaryProgram title: MM Catalogue identifier: AENM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 193181 No. of bytes in distributed program, including test data, etc.: 1298585 Distribution format: tar.gz Programming language: Fortran 90, MPI. Computer: Any architecture with a Fortran 90 compiler and MPI. Operating system: Linux. RAM: Proportional to the system size, in our examples, up to 75Mb Classification: 17.15. External routines: MPICH2 (http://www.mcs.anl.gov/research/projects/mpich2/) Nature of problem: Calculating of the spin- and parity-dependent nuclear level density. Solution method: The algorithm implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The code is parallelized using the Message

  16. Density matrix reconstruction of three-level atoms via Rydberg electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Gavryusev, V.; Signoles, A.; Ferreira-Cao, M.; Zürn, G.; Hofmann, C. S.; Günter, G.; Schempp, H.; Robert-de-Saint-Vincent, M.; Whitlock, S.; Weidemüller, M.

    2016-08-01

    We present combined measurements of the spatially resolved optical spectrum and the total excited-atom number in an ultracold gas of three-level atoms under electromagnetically induced transparency conditions involving high-lying Rydberg states. The observed optical transmission of a weak probe laser at the center of the coupling region exhibits a double peaked spectrum as a function of detuning, while the Rydberg atom number shows a comparatively narrow single resonance. By imaging the transmitted light onto a charge-coupled-device camera, we record hundreds of spectra in parallel, which are used to map out the spatial profile of Rabi frequencies of the coupling laser. Using all the information available we can reconstruct the full one-body density matrix of the three-level system, which provides the optical susceptibility and the Rydberg density as a function of spatial position. These results help elucidate the connection between three-level interference phenomena, including the interplay of matter and light degrees of freedom and will facilitate new studies of many-body effects in optically driven Rydberg gases.

  17. Increasing the maximally random jammed density with electric field to reduce the fat level in chocolate

    NASA Astrophysics Data System (ADS)

    Tao, R.; Tang, H.

    Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. For example, a typical molding chocolate has various fat up to 40% in total and chocolate for covering ice cream has fat 50 -60%. Especially, as children are the leading chocolate consumers, reducing the fat level in chocolate products to make them healthier is important and urgent. While this issue was called into attention and elaborated in articles and books decades ago and led to some patent applications, no actual solution was found unfortunately. Why is reducing fat in chocolate so difficult? What is the underlying physical mechanism? We have found that this issue is deeply related to the basic science of soft matters, especially to their viscosity and maximally random jammed (MRJ) density φx. All chocolate productions are handling liquid chocolate, a suspension with cocoa solid particles in melted fat, mainly cocoa butter. The fat level cannot be lower than 1-φxin order to have liquid chocolate to flow. Here we show that that with application of an electric field to liquid chocolate, we can aggregate the suspended particles into prolate spheroids. This microstructure change reduces liquid chocolate's viscosity along the flow direction and increases its MRJ density significantly. Hence the fat level in chocolate can be effectively reduced. We are looking forward to a new class of healthier and tasteful chocolate coming to the market soon. Dept. of Physics, Temple Univ, Philadelphia, PA 19122.

  18. Lowering low-density lipoprotein cholesterol levels in patients with type 2 diabetes mellitus

    PubMed Central

    Bays, Harold E

    2014-01-01

    Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia, insulin resistance, and/or progressive loss of β-cell function. T2DM patients are at increased risk of micro- and macrovascular disease, and are often considered as representing an atherosclerotic coronary heart disease (CHD) risk equivalent. Interventions directed at glucose and lipid level control in T2DM patients may reduce micro- and macrovascular disease. The optimal T2DM agent is one that lowers glucose levels with limited risk for hypoglycemia, and with no clinical trial evidence of worsening CHD risk. Lipid-altering drugs should preferably reduce low-density lipoprotein cholesterol and apolipoprotein B (apo B) and have evidence that the mechanism of action reduces CHD risk. Statins reduce low-density lipoprotein cholesterol and apo B and have evidence of improving CHD outcomes, and are thus first-line therapy for the treatment of hypercholesterolemia. In patients who do not achieve optimal lipid levels with statin therapy, or who are intolerant to statin therapy, add-on therapy or alternative therapies may be indicated. Additional available agents to treat hypercholesterolemic patients with T2DM include bile acid sequestrants, fibrates, niacin, and ezetimibe. This review discusses the use of these alternative agents to treat hypercholesterolemia in patients with T2DM, either as monotherapy or in combination with statin therapy. PMID:25045281

  19. The Hagedorn spectrum, nuclear level densities and first order phase transitions

    SciTech Connect

    Moretto, Luciano G.; Larsen, A. C.; Guttormsen, M.; Siem, S.

    2015-10-15

    An exponential mass spectrum, like the Hagedorn spectrum, with slope 1/T{sub H} was interpreted as fixing an upper limiting temperature T{sub H} that the system can achieve. However, thermodynamically, such spectrum indicates a 1{sup st} order phase transition at a fixed temperature T{sub H}. A much lower energy example is the log linear level nuclear density below the neutron binding energy that prevails throughout the nuclear chart. We show that, for non-magic nuclei, such linearity implies a 1{sup st} order phase transition from the pairing superfluid to an ideal gas of quasi particles.

  20. Low-density lipoprotein cholesterol level and statin use among Medicare beneficiaries with diabetes mellitus.

    PubMed

    Qualls, Laura G; Hammill, Bradley G; Maciejewski, Matthew L; Curtis, Lesley H; Jones, W Schuyler

    2016-05-01

    At the time of this study, guidelines recommended a primary goal of low-density lipoprotein cholesterol level less than 100 mg/dL for all patients, an optional goal of low-density lipoprotein cholesterol less than 70 mg/dL for patients with overt cardiovascular disease and statins for patients with diabetes and overt cardiovascular disease and patients 40 years and older with diabetes and at least one risk factor for cardiovascular disease. This study examined statin use and achievement of lipid goals among 111,730 Medicare fee-for-service beneficiaries 65 years and older in 2011. Three-quarters of patients met the low-density lipoprotein cholesterol goal of less than 100 mg/dL. Patients with cardiovascular disease were more likely to meet the goal than those without, not controlling for other differences. Patients on a statin were more likely to meet the goal. There is considerable opportunity for improvement in cholesterol management in high-risk patients with diabetes mellitus. PMID:26802221

  1. Reduction in Postoperative High-Density Lipoprotein Cholesterol Levels in Children Undergoing the Fontan Operation

    PubMed Central

    Argraves, W. Scott; Graham, Eric M.; Slate, Elizabeth H.; Atz, Andrew M.; Bradley, Scott M.; McQuinn, Tim C.; Wilkerson, Brent A.; Wing, Shane B.

    2015-01-01

    Despite the emerging relevance of high-density lipoprotein (HDL) in the inflammatory cascade and vascular barrier integrity, HDL levels in children undergoing cardiac surgery are unexplored. As a measure of HDL levels, the HDL-cholesterol (HDL-C) in single-ventricle patients was quantified before and after the Fontan operation, and it was determined whether relationships existed between the duration and the type of postoperative pleural effusions. The study prospectively enrolled 12 children undergoing the Fontan operation. Plasma HDL-C levels were measured before and after cardiopulmonary bypass. The outcome variables of interest were the duration and type of chest tube drainage (chylous vs. nonchylous). The Kendall rank correlation coefficient and the Wilcoxon rank sum test were used. There were 11 complete observations. The median preoperative HDL-C level for all the subjects was 30 mg/dl (range, 24–53 mg/dl), and the median postcardiopulmonary bypass level was 21 mg/dl (range, 14–46 mg/dl) (p = 0.004). There was a tendency toward a moderate inverse correlation (–0.42) between the postcardiopulmonary bypass HDL-C level and the duration of chest tube drainage, but the result was not statistically significant (p = 0.07). In the chylous effusion group, the median postcardiopulmonary bypass HDL-C tended to be lower (16 vs. 23 mg/dl; p = 0.09). After the Fontan operation, the plasma HDL-C levels in children are significantly reduced. It is reasonable to conclude that the reduction in HDL-C reflects reduced plasma levels of HDL particles, which may have pertinent implications in postoperative pleural effusions given the antiinflammatory and endothelial barrier functions of HDL. PMID:22411716

  2. Parity-projected shell model Monte Carlo level densities for medium-mass nuclei

    SciTech Connect

    Oezen, C.; Langanke, K.; Martinez-Pinedo, G.; Dean, D. J.

    2008-11-11

    We investigate the effects of single-particle structure and pairing on the equilibration of positive and negative-parity level densities for the even-even nuclei {sup 58,62,66}Fe and {sup 58}Ni and the odd-A nuclei {sup 59}Ni and {sup 65}Fe. Calculations are performed using the shell model Monte Carlo method in the complete fp-gds shell-model space using a pairing+quadrupole type residual interaction. We find for the even-even nuclei that the positive-parity states dominate at low excitation energies due to strong pairing correlations. At excitation energies at which pairs are broken, single-particle structure of these nuclei is seen to play the decisive role for the energy dependence of the ratio of negative-to-positive parity level densities. We also find that equilibration energies are noticeably lower for the odd-A nuclei {sup 59}Ni and {sup 65}Fe than for the neighboring even-even nuclei {sup 58}Ni and {sup 66}Fe.

  3. Level densities and gamma-ray strength functions in 170,171,172-Yb

    SciTech Connect

    Agvaanluvsan, U; Schiller, A; Becker, J; Bernstein, L; Garrett, P; Guttormsen, M; Mitchell, G; Rekstad, J; Siem, S; Voinov, A; Younes, W

    2004-07-28

    Level densities and radiative strength functions in {sup 171}Yb and {sup 170}Yb nuclei have been measured using the {sup 171}Yb({sup 3}He{sup 3}He{gamma}){sup 171}Yb and {sup 171}Yb({sup 3}He,{alpha}{gamma}){sup 170}Yb reactions. New data on {sup 171}Yb are compared to a previous measurement for {sup 171}Yb from the {sup 172}Yb({sup 3}He,{alpha}{gamma}){sup 171}Yb reaction. Systematics of level densities and radiative strength functions in {sup 170,171,172}Yb are established. The entropy excess in {sup 171}Yb relative to the even-even nuclei {sup 170,172}Yb due to the unpaired neutron quasiparticle is found to be approximately 2k{sub B}. Results for the radiative strength function from the two reactions lead to consistent parameters characterizing the ''pygmy'' resonances. Pygmy resonances in the {sup 170,172}Yb populated by the ({sup 3}He,{alpha}) reaction appear to be split into two components for both of which a complete set of resonance parameters are obtained.

  4. Leveling coatings for reducing the atomic oxygen defect density in protected graphite fiber epoxy composites

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Degroh, K. K.; Podojil, G.; Mccollum, T.; Anzic, J.

    1992-01-01

    Pinholes or other defect sites in a protective oxide coating provide pathways for atomic oxygen in low Earth orbit to reach underlying material. One concept for enhancing the lifetime of materials in low Earth orbits is to apply a leveling coating to the material prior to applying any reflective and protective coatings. Using a surface tension leveling coating concept, a low viscosity epoxy was applied to the surface of several composite coupons. A protective layer of 1000 A of SiO2 was deposited on top of the leveling coating, and the coupons were exposed to an atomic oxygen environment in a plasma asher. Pinhole populations per unit area were estimated by counting the number of undercut sites observed by scanning electron microscopy. Defect density values of 180,000 defects/sq cm were reduced to about 1000 defects/sq cm as a result of the applied leveling coating. These improvements occur at a mass penalty of about 2.5 mg/sq cm.

  5. Leveling coatings for reducing the atomic oxygen defect density in protected graphite fiber epoxy composites

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Degroh, Kim K.; Podojil, G.; Mccollum, T.; Anzic, J.

    1992-01-01

    Pinholes or other defect sites in a protective oxide coating provide pathways for atomic oxygen in low Earth orbit to reach underlying material. One concept of enhancing the lifetime of materials in low Earth orbit is to apply a leveling coating to the material prior to applying any reflective and protective coatings. Using a surface tension leveling coating concept, a low viscosity epoxy was applied to the surface of several composite coupons. A protective layer of 1000 A of SiO2 was deposited on top of the leveling coating, and the coupons were exposed to an atomic oxygen environment in a plasma asher. Pinhole populations per unit area were estimated by counting the number of undercut sites observed by scanning electron microscopy. Defect density values of 180,000 defects/sq cm were reduced to about 1000 defects/sq cm as a result of the applied leveling coating. These improvements occur at a mass penalty of about 2.5 mg/sq cm.

  6. Leveling coatings for reducing the atomic oxygen defect density in protected graphite fiber epoxy composites

    NASA Astrophysics Data System (ADS)

    Jaworske, D. A.; Degroh, Kim K.; Podojil, G.; McCollum, T.; Anzic, J.

    1992-11-01

    Pinholes or other defect sites in a protective oxide coating provide pathways for atomic oxygen in low Earth orbit to reach underlying material. One concept of enhancing the lifetime of materials in low Earth orbit is to apply a leveling coating to the material prior to applying any reflective and protective coatings. Using a surface tension leveling coating concept, a low viscosity epoxy was applied to the surface of several composite coupons. A protective layer of 1000 A of SiO2 was deposited on top of the leveling coating, and the coupons were exposed to an atomic oxygen environment in a plasma asher. Pinhole populations per unit area were estimated by counting the number of undercut sites observed by scanning electron microscopy. Defect density values of 180,000 defects/sq cm were reduced to about 1000 defects/sq cm as a result of the applied leveling coating. These improvements occur at a mass penalty of about 2.5 mg/sq cm.

  7. Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

    PubMed Central

    Funamoto, Masafumi; Sunagawa, Yoichi; Katanasaka, Yasufumi; Miyazaki, Yusuke; Imaizumi, Atsushi; Kakeya, Hideaki; Yamakage, Hajime; Satoh-Asahara, Noriko; Komiyama, Maki; Wada, Hiromichi; Hasegawa, Koji; Morimoto, Tatsuya

    2016-01-01

    Purpose COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL) complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD. Patients and methods This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated. Results There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure and hemoglobin A1c and LDL-cholesterol, triglyceride, or high-density lipoprotein-cholesterol levels after treatment were similar for the two groups. However, the percent change in the AT-LDL level was significantly (P=0.020) lower in the Theracurmin® group compared with the placebo group. Conclusion Theracurmin® reduced levels of atherosclerotic AT-LDL, which may lead to the prevention of future cardiovascular events in mild COPD subjects. PMID:27616885

  8. Evidence for low high-density lipoprotein cholesterol levels in Australian indigenous peoples: a systematic review

    PubMed Central

    2014-01-01

    Background Low plasma high-density lipoprotein cholesterol (HDL-C) levels are a strong, independent, but poorly understood risk factor for cardiovascular disease (CVD). Although this atherogenic lipid abnormality has been widely reported in Australia’s Indigenous peoples, Aboriginal and Torres Strait Islanders, the evidence has not come under systematic review. This review therefore examines published data for Indigenous Australians reporting 1) mean HDL-C levels for both sexes and 2) factors associated with low HDL-C. Methods PubMed, Medline and Informit ATSI Health databases were systematically searched between 1950 and 2012 for studies on Indigenous Australians reporting mean HDL-C levels in both sexes. Retrieved studies were evaluated by standard criteria. Low HDL-C was defined as: <1.0 mmol/L. Analyses of primary data associating measures of HDL-C with other CVD risk factors were also performed. Results Fifteen of 93 retrieved studies were identified for inclusion. These provided 58 mean HDL-C levels; 29 for each sex, most obtained in rural/regional (20%) or remote settings (60%) and including 51–1641 participants. For Australian Aborigines, mean HDL-C values ranged between 0.81-1.50 mmol/L in females and 0.76-1.60 mmol/L in males. Two of 15 studies reported HDL-C levels for Torres Strait Islander populations, mean HDL-C: 1.00 or 1.11 mmol/L for females and 1.01 or 1.13 mmol/L for males. Low HDL-C was observed only in rural/regional and remote settings - not in national or urban studies (n = 3) in either gender. Diabetes prevalence, mean/median waist-to-hip ratio and circulating C-reactive protein levels were negatively associated with HDL-C levels (all P < 0.05). Thirty-four per cent of studies reported lower mean HDL-C levels in females than in males. Conclusions Very low mean HDL-C levels are common in Australian Indigenous populations living in rural and remote communities. Inverse associations between HDL-C and central obesity, diabetes

  9. Reliable Energy Level Alignment at Physisorbed Molecule–Metal Interfaces from Density Functional Theory

    PubMed Central

    2015-01-01

    A key quantity for molecule–metal interfaces is the energy level alignment of molecular electronic states with the metallic Fermi level. We develop and apply an efficient theoretical method, based on density functional theory (DFT) that can yield quantitatively accurate energy level alignment information for physisorbed metal–molecule interfaces. The method builds on the “DFT+Σ” approach, grounded in many-body perturbation theory, which introduces an approximate electron self-energy that corrects the level alignment obtained from conventional DFT for missing exchange and correlation effects associated with the gas-phase molecule and substrate polarization. Here, we extend the DFT+Σ approach in two important ways: first, we employ optimally tuned range-separated hybrid functionals to compute the gas-phase term, rather than rely on GW or total energy differences as in prior work; second, we use a nonclassical DFT-determined image-charge plane of the metallic surface to compute the substrate polarization term, rather than the classical DFT-derived image plane used previously. We validate this new approach by a detailed comparison with experimental and theoretical reference data for several prototypical molecule–metal interfaces, where excellent agreement with experiment is achieved: benzene on graphite (0001), and 1,4-benzenediamine, Cu-phthalocyanine, and 3,4,9,10-perylene-tetracarboxylic-dianhydride on Au(111). In particular, we show that the method correctly captures level alignment trends across chemical systems and that it retains its accuracy even for molecules for which conventional DFT suffers from severe self-interaction errors. PMID:25741626

  10. Hysteresis in Carbon Nanotube Transistors: Measurement and Analysis of Trap Density, Energy Level, and Spatial Distribution.

    PubMed

    Park, Rebecca Sejung; Shulaker, Max Marcel; Hills, Gage; Suriyasena Liyanage, Luckshitha; Lee, Seunghyun; Tang, Alvin; Mitra, Subhasish; Wong, H-S Philip

    2016-04-26

    We present a measurement technique, which we call the Pulsed Time-Domain Measurement, for characterizing hysteresis in carbon nanotube field-effect transistors, and demonstrate its applicability for a broad range of 1D and 2D nanomaterials beyond carbon nanotubes. The Pulsed Time-Domain Measurement enables the quantification (density, energy level, and spatial distribution) of charged traps responsible for hysteresis. A physics-based model of the charge trapping process for a carbon nanotube field-effect transistor is presented and experimentally validated using the Pulsed Time-Domain Measurement. Leveraging this model, we discover a source of traps (surface traps) unique to devices with low-dimensional channels such as carbon nanotubes and nanowires (beyond interface traps which exist in today's silicon field-effect transistors). The different charge trapping mechanisms for interface traps and surface traps are studied based on their temperature dependencies. Through these advances, we are able to quantify the interface trap density for carbon nanotube field-effect transistors (∼3 × 10(13) cm(-2) eV(-1) near midgap), and compare this against a range of previously studied dielectric/semiconductor interfaces. PMID:27002483

  11. [Composition and Density of Soil Fauna in the Region with Enhanced Radioactivity Level (Komi Republic, Vodnyi)].

    PubMed

    Kolesnikova, A A; Kudrin, A A; Konakova, T N; Taskaeva, A A

    2015-01-01

    Studies on the influence of high levels of radiation on soil fauna were carried out in 2012 in the territory formed as a result of the activity of the enterprise for extraction and production of radium from reservoir water and waste of uranium ore from 1931 to 1956. At present the local radioactive pollution in this area is caused by the presence of heavy natural radionuclides 226Ra, 238U and products of their disintegration in soils. The oppression of soil invertebrate.fauna in pine forests and meadows with high levels of radionuclides and heavy metals is revealed. Also shown is the decrease in the number and density of different taxonomic groups of invertebrates, reduction of the diversity and spectrum of trophic groups and vital forms in the area with a high content of radionuclides in soil. Our results are in agreement with the results obtained by the similar studies showing negative influence of high-level ionizing radiation on soil fauna. PMID:26310020

  12. Organic semiconductor density of states controls the energy level alignment at electrode interfaces

    PubMed Central

    Oehzelt, Martin; Koch, Norbert; Heimel, Georg

    2014-01-01

    Minimizing charge carrier injection barriers and extraction losses at interfaces between organic semiconductors and metallic electrodes is critical for optimizing the performance of organic (opto-) electronic devices. Here, we implement a detailed electrostatic model, capable of reproducing the alignment between the electrode Fermi energy and the transport states in the organic semiconductor both qualitatively and quantitatively. Covering the full phenomenological range of interfacial energy level alignment regimes within a single, consistent framework and continuously connecting the limiting cases described by previously proposed models allows us to resolve conflicting views in the literature. Our results highlight the density of states in the organic semiconductor as a key factor. Its shape and, in particular, the energy distribution of electronic states tailing into the fundamental gap is found to determine both the minimum value of practically achievable injection barriers as well as their spatial profile, ranging from abrupt interface dipoles to extended band-bending regions. PMID:24938867

  13. Estimation of loading density of underground well repositories for solid high-level radioactive wastes

    NASA Astrophysics Data System (ADS)

    Malkovsky, V. I.; Pek, A. A.

    2007-06-01

    The convective transfer of radionuclides by subsurface water from a geological repository of solidified high-level radioactive wastes (HLW) is considered. The repository is a cluster of wells of large diameter with HLW disposed of in the lower portions of the wells. The safe distance between wells as a function of rock properties and parameters of well loading with wastes has been estimated from mathematical modeling. A maximum permissible concentration of radionuclides in subsurface water near the ground surface above the repository is regarded as a necessary condition of safety. The estimates obtained show that well repositories allow for a higher density of solid HLW disposal than shaft storage facilities. Advantages and disadvantages of both types of storage facilities are considered in order to estimate the prospects for their use for underground disposal of solid HLW.

  14. Level density and mechanism of deuteron-induced reactions on 54,58,56Fe

    NASA Astrophysics Data System (ADS)

    Ramirez, A. P. D.; Voinov, A. V.; Grimes, S. M.; Byun, Y.; Brune, C. R.; Massey, T. N.; Akhtar, S.; Dhakal, S.; Parker, C. E.

    2015-07-01

    Deuteron elastic cross sections, as well as neutron, proton, and α -particle emission spectra, from d + 54,58,56Fe reactions have been measured with deuteron beam energies of 5, 7, and 9 MeV. Optical model parameters have been tested against our experimental data. The fraction of total reaction cross section responsible for the formation of compound nuclei has been deduced from the angular distributions. The degree of discrepancy between calculated and experimental compound cross sections was found to increase with increasing neutron number. The nuclear level densities of the residual nuclei 57Co, 55Co, 57Fe, 55Fe, 52Mn, 54Mn have been deduced from the compound double differential cross sections. The Gilbert-Cameron model with Iljinov parameter systematics [A. S. Iljinov and M. V. Mebel, Nucl. Phys. A 543, 517 (1992)], 10.1016/0375-9474(92)90278-R was found to have a good agreement with our results.

  15. Level density and mechanism of deuteron-induced reactions on Fe54,56,58

    DOE PAGESBeta

    Ramirez, A. P. D.; Voinov, A. V.; Grimes, S. M.; Byun, Y.; Brune, C. R.; Massey, T. N.; Akhtar, S.; Dhakal, S.; Parker, C. E.

    2015-07-06

    Here, deuteron elastic cross sections, as well as neutron, proton, and α-particle emission spectra, from d+54,56,58Fe reactions have been measured with deuteron beam energies of 5, 7, and 9 MeV. Optical model parameters have been tested against our experimental data. The fraction of total reaction cross section responsible for the formation of compound nuclei has been deduced from the angular distributions. The degree of discrepancy between calculated and experimental compound cross sections was found to increase with increasing neutron number. The nuclear level densities of the residual nuclei 55Co, 57Co, 55Fe, 57Fe, 52Mn, and 54Mn have been deduced from themore » compound double differential cross sections. The Gilbert-Cameron model with Iljinov parameter systematics [A. S. Iljinov and M. V. Mebel, Nucl. Phys. A 543, 517 (1992)] was found to have a good agreement with our results.« less

  16. Physical Activity Level of Post-menopausal Women with Low Bone Mineral Density.

    PubMed

    Dallanezi, Glauber; Freire, Beatriz Funayama Alvarenga; Nahás, Eliana Aguiar Petri; Nahás-Neto, Jorge; Corrente, José Eduardo; Mazeto, Gláucia Maria Ferreira da Silva

    2016-05-01

    Introduction Proper physical activity is related to the prevention and the treatment of osteoporosis. Purpose To assess the level of physical activity (PA) in post-menopausal women with low bone mineral density (BMD). Methods This cross-sectional clinical study included 123 post-menopausal women. The inclusion criteria were: age of ≥ 45 years with last menses at least 12 months prior to the initiation of the study, and bone density scan (BDS) values measured over the preceding 12 months. Women with severe osteoarthritis were excluded. Women were allocated into three groups, according to BMD measured by BDS [osteoporosis (OP; 54 women), osteopenia (35 women), and normal bone density (NBD; 35 women)], and compared for general, clinical, and anthropometric data, and for PA level. The latter was assessed using the International Physical Activity Questionnaire (IPAQ), in metabolic equivalent of task (MET) units. Participants were classified as sedentary, active or very active. Quantitative variables were compared using ANOVA followed by Tukey's test. Associations between qualitative variables were tested by Chi-square (χ2) or Fisher's exact test. In order to check for differences among groups and IPAQ domains, a generalized linear model with Gamma distribution was adjusted for values in METs. Results The OP group differed from the NBD group regarding age (61.8 ± 10.1 and 52.9 ± 5.4 years), percentage of participants with self-declared white ethnicity (43.9 and 28.0%), body mass index (BMI - 25.7 ± 5.4 and 30.9 ± 5.1 kg/m(2)), and time since menopause (15.5 ± 7.5 and 5.8 ± 4.5 years). Smoking rates were higher in the OP (55.6%) and NBD groups (33.3%) than in the osteopenia group (11.1%). Within the OP group, the rate of subjects with sedentary lifestyles was higher (42.6%), and time spent sitting was greater (344.3 ± 204.8 METs) than in the groups with osteopenia (20.0% and 300.9 ± 230.6 METs) and NBD (17.7% and 303

  17. Effects of maximal doses of atorvastatin versus rosuvastatin on small dense low-density lipoprotein cholesterol levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maximal doses of atorvastatin and rosuvastatin are highly effective in lowering low-density lipoprotein (LDL) cholesterol and triglyceride levels; however, rosuvastatin has been shown to be significantly more effective than atorvastatin in lowering LDL cholesterol and in increasing high-density lipo...

  18. Intensive Lowering of Low-Density Lipoprotein Cholesterol Levels for Primary Prevention of Coronary Artery Disease

    PubMed Central

    Karalis, Dean G.

    2009-01-01

    Coronary artery disease (CAD) is the leading cause of morbidity and mortality in the United States, and a high concentration of low-density lipoprotein cholesterol (LDL-C) is a major risk factor for CAD. Current guidelines recommend the use of statins to lower LDL-C levels for the primary prevention of CAD based on an individual's risk factor profile and baseline LDL-C level. For moderaterisk individuals, those with 2 or more major risk factors for CAD and a Framingham risk score of 10% to 20%, the recommendation is to use a statin to lower LDL-C levels to less than 130 mg/dL. However, up to 40% of individuals who develop CAD have LDL-C levels lower than this cutoff. In 2004, the National Cholesterol Education Program Adult Treatment Panel III guidelines were updated to include an LDL-C goal of less than 100 mg/dL for individuals at moderately high risk of developing CAD. The guidelines identified several risk factors that when present would favor the use of pharmacological therapy to achieve this more aggressive LDL-C goal. This review evaluates the evidence supporting an LDL-C target of less than 100 mg/dL for moderately high-risk individuals and reviews those risk factors that when present help identify patients who would benefit from achieving this lower LDL-C goal. English-language publications in MEDLINE and references from relevant articles published between January 1, 1980, and November 30, 2008, were reviewed. Main keywords searched were coronary artery disease, hyperlipidemia, statins, cardiac risk factors, inflammatory markers, metabolic syndrome, and coronary artery calcium. PMID:19339653

  19. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. I. Argon plasmas

    SciTech Connect

    Boffard, John B. Lin, Chun C.; Culver, Cody; Wang, Shicong; Wendt, Amy E.; Radovanov, Svetlana; Persing, Harold

    2014-03-15

    Vacuum ultraviolet (VUV) photons emitted from excited atomic states are ubiquitous in material processing plasmas. The highly energetic photons can induce surface damage by driving surface reactions, disordering surface regions, and affecting bonds in the bulk material. In argon plasmas, the VUV emissions are due to the decay of the 1s{sub 4} and 1s{sub 2} principal resonance levels with emission wavelengths of 104.8 and 106.7 nm, respectively. The authors have measured the number densities of atoms in the two resonance levels using both white light optical absorption spectroscopy and radiation-trapping induced changes in the 3p{sup 5}4p→3p{sup 5}4s branching fractions measured via visible/near-infrared optical emission spectroscopy in an argon inductively coupled plasma as a function of both pressure and power. An emission model that takes into account radiation trapping was used to calculate the VUV emission rate. The model results were compared to experimental measurements made with a National Institute of Standards and Technology-calibrated VUV photodiode. The photodiode and model results are in generally good accord and reveal a strong dependence on the neutral gas temperature.

  20. First pregnancy characteristics, postmenopausal breast density, and salivary sex hormone levels in a population at high risk for breast cancer

    PubMed Central

    Mockus, Mary; Prebil, LeeAnn; Ereman, Rochelle; Dollbaum, Charles; Powell, Mark; Yau, Christina; Benz, Christopher C.

    2015-01-01

    Background It remains unknown if later life breast cancer risk as determined by reproductive history is mediated by postmenopausal breast density and/or sex steroid levels. Methods Increased breast density is a strong surrogate for future breast cancer risk. A cross-sectional study with a longitudinal follow-up for breast health outcomes evaluated women without breast cancer (n = 1023; 682 = parous), drawn from a high risk postmenopausal population, with questionnaire- reported reproductive histories. The questionnaire was linked to prospective screening mammogram breast density measurements, and saliva biospecimens that were used to assess sex steroid hormone levels. Results Expected age- and postmenopause- related declines in salivary estradiol (E), progesterone (P), dehydroepiandrosterone (DHEA) and testosterone (T) levels were observed. This was most pronounced for DHEA and T, which were also the only postmenopausal hormone levels significantly associated with any reproductive characteristics: parity and breast feeding for DHEA, and age-at-first birth for T. Postmenopausal breast density was borderline significantly lower with parity and higher body mass index (BMI). After multivariate analysis, T was the only hormone level to retain any association (negative, p < 0.05) with breast density. Conclusions and general significance While reproductive characteristics, in particular parity, generally demonstrated independent associations with postmenopausal breast density and E, P and DHEA levels, T levels showed concordant inverse associations with age-at-first birth and breast density. These findings suggest that reproductive effects and later life salivary sex steroid hormone levels may have independent effects on later life breast density and cancer risk. PMID:26317068

  1. Association of chemerin levels and bone mineral density in Chinese obese postmenopausal women.

    PubMed

    Shi, Liang; Mao, Chaoming; Wang, Xuefeng; Liu, Rencong; Li, Lin; Mou, Xiao; Xu, Ping; Li, Hongli; Xu, Chengcheng; Yuan, Guoyue; Wang, Bin; Zhang, Hao

    2016-08-01

    Increasing evidence suggests the association between obesity and bone metabolism. However, whether excessive fat accumulation has a beneficial or adverse effect on bone health remains controversial. Chemerin is a novel adipocyte-derived hormone and a chemoattractant cytokine that regulates adipogenesis. This study was performed to investigate the associations of serum chemerin with bone mineral density (BMD) and serum pro-inflammatory cytokine levels in 543 Chinese obese postmenopausal women. BMD of the femoral neck and lumbar spine, lean mass, and fat mass were measured using dual energy X-ray absorptiometry. Anthropometric assessment and laboratory measurements were performed. The age, time after menopause, and fat mass were negatively correlated with femoral and lumbar BMD, whereas lean mass was positively correlated with aforementioned variables. Furthermore, BMD at the lumbar spine was inversely associated with serum chemerin and TNF-α levels (r = -0.155, P = 0.001; r = -0.147, P = 0.001). Multiple linear regression analyses showed that serum chemerin levels were negatively correlated with BMD at the lumbar site after controlling for the age, lean, and fat mass (β = -0.125, P = 0.001). Chronic low-grade inflammation state in obese population has an inverse effect on bone mass. Chemerin as an adipocytokine and chemoattractant negatively affects the bone mass of Chinese obese postmenopausal women. Further studies are needed to confirm the potential role of chemerin in the crosstalk between bone and fat accumulation in obese population. PMID:27583869

  2. Association of chemerin levels and bone mineral density in Chinese obese postmenopausal women

    PubMed Central

    Shi, Liang; Mao, Chaoming; Wang, Xuefeng; Liu, Rencong; Li, Lin; Mou, Xiao; Xu, Ping; Li, Hongli; Xu, Chengcheng; Yuan, Guoyue; Wang, Bin; Zhang, Hao

    2016-01-01

    Abstract Increasing evidence suggests the association between obesity and bone metabolism. However, whether excessive fat accumulation has a beneficial or adverse effect on bone health remains controversial. Chemerin is a novel adipocyte-derived hormone and a chemoattractant cytokine that regulates adipogenesis. This study was performed to investigate the associations of serum chemerin with bone mineral density (BMD) and serum pro-inflammatory cytokine levels in 543 Chinese obese postmenopausal women. BMD of the femoral neck and lumbar spine, lean mass, and fat mass were measured using dual energy X-ray absorptiometry. Anthropometric assessment and laboratory measurements were performed. The age, time after menopause, and fat mass were negatively correlated with femoral and lumbar BMD, whereas lean mass was positively correlated with aforementioned variables. Furthermore, BMD at the lumbar spine was inversely associated with serum chemerin and TNF-α levels (r = −0.155, P = 0.001; r = −0.147, P = 0.001). Multiple linear regression analyses showed that serum chemerin levels were negatively correlated with BMD at the lumbar site after controlling for the age, lean, and fat mass (β = −0.125, P = 0.001). Chronic low-grade inflammation state in obese population has an inverse effect on bone mass. Chemerin as an adipocytokine and chemoattractant negatively affects the bone mass of Chinese obese postmenopausal women. Further studies are needed to confirm the potential role of chemerin in the crosstalk between bone and fat accumulation in obese population. PMID:27583869

  3. Effect of Vitamin Levels and Different Stocking Densities on Performance, Nutrient Digestibility, and Blood Characteristics of Growing Pigs

    PubMed Central

    Zhang, Z. F.; Li, J.; Park, J. C.; Kim, I. H.

    2013-01-01

    This study was conducted to evaluate the effects of dietary vitamin levels and stocking densities on growth performance, nutrient digestibility, and blood characteristics in growing pigs. A 2×3 factorial (two vitamin levels, three regimens of stocking densities) arrangement was utilized with 96 pigs (23.10×0.95 kg initial body weight and 63 d of age) for 36 d. The pigs were allocated to pens with different stocking density (0.64, 0.48, and 0.38 m2/pig, respectively). The diets used in this study were a normal diet (based on NRC) and a high level of vitamin diet (2-fold higher than normal diet). The ADG and ADFI of pigs were decreased as the stocking density increased (p = 0.03 and p = 0.01, respectively). The G/F of pigs was 5% lower in the high vitamin treatment (p = 0.03) as compared with the control treatment. The apparent total tract digestibility (ATTD) of DM and N digestibility was negatively affected by the high level of vitamin in diets (p = 0.05 and p = 0.04, respectively). Moreover, a significant and negative effect on the ATTD of N was detected in the large groups (linear, p = 0.02). Blood cortisol concentration was increased with increasing stocking density (linear, p = 0.05), and was decreased by high level of vitamin (p = 0.04) at the end of this experiment. Stocking density also caused a linear reduction in WBC concentration (p = 0.05). Our data indicated that the principal effect of stocking density was not reliant on dietary vitamin levels. In conclusion, results indicated that doubling the vitamin supplementation did not improve the growth performance of pigs in high density. However, the blood cortisol concentration was decreased but the ATTD of N digestibility was impaired by high level of vitamin diet. PMID:25049782

  4. Nigerian propolis improves blood glucose, glycated hemoglobin A1c, very low-density lipoprotein, and high-density lipoprotein levels in rat models of diabetes

    PubMed Central

    Oladayo, Mustafa Ibrahim

    2016-01-01

    Objective: According to our previous studies, propolis of Nigerian origin showed some evidence of hypoglycemic and hypolipidemic activities in addition to its ability to ameliorate oxidative-stress-induced organ dysfunction. This study was carried out to determine whether an ethanolic extract of Nigerian propolis (EENP) improves glycated hemoglobin A1c (HbA1c), fasting plasma glucose, very low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) concentrations in rats that have alloxan diabetes. Materials and Methods: Diabetes was induced with alloxan (110 mg/kg). Animals were divided into 5 groups (n = 5); Group 1 was non-diabetic receiving normal saline and Group 2 was diabetic but also received only normal saline. Groups 3, 4, and 5 were diabetic receiving 200 mg/kg propolis, 300 mg/kg propolis, and 150 mg/kg metformin, respectively, for 42 days. Results: Hyperglycemia, elevated serum level of VLDL, elevated plasma level of HbA1c, and decreased levels of HDL were observed in the diabetic untreated animals. Nigerian propolis decreased blood glucose level and serum level of VLDL but elevated HDL level. These changes were significant (P < 0.05). The levels of plasma HbA1c were also reduced in the propolis-treated groups, and the reduction was significant (P < 0.05). Conclusion: Nigerian propolis contains compounds exhibiting hypoglycemic, antihyperlipidemic, and HbA1c reducing activities. PMID:27366348

  5. Targeting residual cardiovascular risk: raising high-density lipoprotein cholesterol levels.

    PubMed

    Hausenloy, D J; Yellon, D M

    2008-11-01

    The last 20 years have witnessed dramatic reductions in cardiovascular risk using 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ("statins") to lower levels of low-density lipoprotein cholesterol (LDL-C). Using this approach one can achieve a reduction in the risk of major cardiovascular events of 21% for every 1 mmol/l (39 mg/dl) decrease in LDL-C. However, despite intensive therapy with high dose "statins" to lower LDL-C levels below 2.6 mmol/l (100 mg/dl), the risk of a major cardiovascular event in patients with established coronary artery disease remains significant at a level approaching an annual risk of 9%, paving the way for new strategies for reducing the residual cardiovascular risk in this patient group. Early epidemiological studies have identified low levels of high-density lipoprotein cholesterol (HDL-C) (<1.0 mmol/l or 40 mg/dl), a common feature of type 2 diabetes mellitus and the metabolic syndrome, to be an independent determinant of increased cardiovascular risk. The beneficial effects of HDL-C on the cardiovascular system have been attributed to its ability to remove cellular cholesterol, as well as its anti-inflammatory, antioxidant and antithrombotic properties, which act in concert to improve endothelial function and inhibit atherosclerosis, thereby reducing cardiovascular risk. As such, raising HDL-C in patients with aggressively lowered LDL-C provides an additional strategy for addressing the residual cardiovascular risk present in these patients groups. Studies suggest that for every 0.03 mmol/l (1.0 mg/dl) increase in HDL-C, cardiovascular risk is reduced by 2-3%. Raising HDL-C can be achieved by both lifestyle changes and pharmacological means, the former of which include smoking cessation, aerobic exercise, weight loss and dietary manipulation. Therapeutic strategies have included niacin, fibrates, thiazolidinediones and bile acid sequestrants. Newly developed pharmacological agents include apolipoprotein A-I mimetics and

  6. Protection of low density lipoprotein oxidation at chemical and cellular level by the antioxidant drug dipyridamole.

    PubMed Central

    Iuliano, L.; Colavita, A. R.; Camastra, C.; Bello, V.; Quintarelli, C.; Alessandroni, M.; Piovella, F.; Violi, F.

    1996-01-01

    1. The oxidative modification of low density lipoprotein (LDL) is thought to be an important factor in the initiation and development of atherosclerosis. Natural and synthetic antioxidants have been shown to protect LDL from oxidation and to inhibit atherosclerosis development in animals. Synthetic antioxidants are currently being tested, by they are not necessarily safe for human use. 2. We have previously reported that dipyridamole, currently used in clinical practice, is a potent scavenger of free radicals. Thus, we tested whether dipyridamole could affect LDL oxidation at chemical and cellular level. 3. Chemically induced LDL oxidation was made by Cu(II), Cu(II) plus hydrogen peroxide or peroxyl radicals generated by thermolysis of 2,2'-azo-bis(2-amidino propane). Dipyridamole, (1-10 microM), inhibited LDL oxidation as monitored by diene formation, evolution of hydroperoxides and thiobarbituric acid reactive substances, apoprotein modification and by the fluorescence of cis-parinaric acid. 4. The physiological relevance of the antioxidant activity was validated by experiments at the cellular level where dipyridamole inhibited endothelial cell-mediated LDL oxidation, their degradation by monocytes, and cytotoxicity. 5. In comparison with ascorbic acid, alpha-tocopherol and probucol, dipyridamole was the more efficient antioxidant with the following order of activity: dipyridamole > probucol > ascorbic acid > alpha-tocopherol. The present study shows that dipyridamole inhibits oxidation of LDL at pharmacologically relevant concentrations. The inhibition of LDL oxidation is unequivocally confirmed by use of three different methods of chemical oxidation, by several methods of oxidation monitoring, and the pharmacological relevance is demonstrated by the superiority of dipyridamole over the naturally occurring antioxidants, ascorbic acid and alpha-tocopherol and the synthetic antioxidant probucol. Images Figure 6 PMID:8968553

  7. Effects of pairing correlations on the inverse level density parameter of hot rotating nuclei

    NASA Astrophysics Data System (ADS)

    Thi Quynh Huong, Le; Quang Hung, Nguyen; Thi Quynh Trang, Le

    2016-06-01

    Angular momentum dependence of the inverse level density parameter K in the excitation-energy region of ∼ 30 – 40 MeV is studied within the finite-temperature Bardeen-Cooper-Schrieffer (FTBCS) theory and the FTBCS theory that includes the effect due to quasiparticle-number fluctuations (FTBCS1). The two theories take into account the noncollective rotation of the nucleus at nonzero values of z-projection M of the total angular momentum. The comparison between the results obtained within the FTBCS and FTBCS1 as well as the case without pairing correlations and the experimental data for two medium-mass even-even nuclei 108Cd and 122Te shows that by including the pairing corrections the FTBCS and FTBCS1 reproduces quite well all the experimental data, whereas the non-pairing case always overestimates the data. Due to the effect of quasiparticle-number fluctuations, the FTBCS1 gaps at different M values do not collapse at critical temperature TC as in the FTBCS ones but monotonously decrease with increasing T and being finite even at high T. As the result, the values of K obtained within the FTBCS1 are always closer to the experimental data than those obtained within the FTBCS.

  8. Very old adults with better memory function have higher low-density lipoprotein cholesterol levels and lower triglyceride to high-density lipoprotein cholesterol ratios: KOCOA project

    PubMed Central

    Katsumata, Yuriko; Todoriki, Hidemi; Higashiuesato, Yasushi; Yasura, Shotoku; Ohya, Yusuke; Willcox, D. Craig; Dodge, Hiroko H.

    2013-01-01

    We examined cross-sectionally which lipid profiles are associated with better cognitive function among those aged 80 and older-free of dementia (Clinical Dementia Rating ≤ 0.5), functionally independent and community-dwelling. Our cohort consisted of 193 participants from the “Keys to Optimal Cognitive Aging (KOCOA) Project”, a prospective cohort study in Okinawa, Japan. Higher low-density lipoprotein cholesterol levels and lower triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratios were associated with higher scores in memory performance after controlling for confounders. Further research is required to clarify the associations among LDL-C levels, TG/HDL-C ratios, and healthy cognitive aging. PMID:23207484

  9. Secretory IgA, albumin level, and bone density as markers of biostimulatory effects of laser radiation

    NASA Astrophysics Data System (ADS)

    Kucerova, Hana; Dostalova, Tatjana; Himmlova, Lucia; Bartova, Jirina; Mazanek, Jiri

    1998-12-01

    The aim of contribution is to evaluate the effects of low- level laser radiation on healing process after human molars extraction in lower jaw using frequency 5 Hz, 292 Hz and 9000 Hz. Changes in bone density and monitoring of secretory IgA and albumin levels in saliva were used as a marker of biostimulatory effect. Bone density after extraction and 6 month after surgical treatment was examined using the dental digital radiography. Bone healing was followed by osseointegration of bone structure in extraction wound. Changes of bone density, secretory IgA and albumin levels were compared in groups of patients with laser therapy and control group without laser therapy. Differences in levels of the saliva markers (sIgA and albumin) were found to be significant comparing irradiated and non-irradiated groups, as well as comparing groups irradiated by various modulatory frequencies. Density of alveolar bone (histogram) was examined on five slices acquired from every RVG image. Histograms were evaluated with computer program for microscopic image analysis. Differences of density were verified in area of the whole slice. There were no significant differences found between the bone density in irradiated and non irradiated groups perhaps due to our used therapeutical diagram.

  10. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    DOE PAGESBeta

    Voinov, Alexander V.; Grimes, Steven M.; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann -Cecilie; Massey, Thomas N.; Siem, Sunniva

    2013-11-08

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys. 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Furthermore,more » excitation energy dependencies were found to be inconsistent with the Fermi-gas model.« less

  11. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    NASA Astrophysics Data System (ADS)

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2013-11-01

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys.0008-420410.1139/p65-139 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Excitation energy dependencies were found to be inconsistent with the Fermi-gas model.

  12. Serum vitamin D level and bone mineral density in premenopausal Egyptian women with fibromyalgia.

    PubMed

    Olama, Shereem Mohamed; Senna, Mohammed K; Elarman, Mohammed Mohamed; Elhawary, Galal

    2013-01-01

    Patients with fibromyalgia syndrome (FMS) have impaired mobility and therefore get less sunlight exposure, we postulated that they may be at increased risk of developing osteoporosis (OP). The aim of this study was to assess and compare serum vitamin D level and bone mineral density (BMD) value in patients with primary FMS (PFMS) and healthy controls. A total of 50 patients with PFMS participated in this case-control study, and 50 healthy females who were age-matched to the patients were used as the control group. Venous blood samples collected from all subjects were used to evaluate serum 25-hydroxyvitamin D3 (25-OHD). BMD was measured at the lumbar spine (L2-L4) anteroposterior, femoral neck and forearm by dual-energy X-ray absorptiometry. Patients with PFMS had significantly lower serum 25-OHD than controls (15.1 ± 6.1 and 18.8 ± 5.4 ng/ml, respectively, p = 0.0018). Apart from the BMD in the lumbar spine, which was significantly lower in the PFMS patients compared with controls (p = 0.0012), no significant difference was found in other measures of BMD. Compared to PFMS patients who had serum level of the 25-OHD >20 ng/ml, the patients with 25-OHD ≤20 ng/ml are more likely to have impaired short memory (46.4 vs. 13.6%, respectively, p = 0.0136), confusion (50 vs. 18.2%, respectively, p = 0.0199), mood disturbance (60.7 vs. 27.3%, respectively, p = 0.0185), sleep disturbance (53.6 vs. 22.7%, respectively, p = 0.0271), restless leg syndrome (57.1 vs. 27.3%, respectively, p = 0.0346) and palpitation (67.9 vs. 36.4%, respectively, p = 0.0265). Serum level of the 25-OHD is inversely correlated with visual analogue scale (VAS) of pain (p = 0.016), Beck score for depression (p = 0.020) and BMD at lumbar spine (p = 0.012). The lumbar BMD inversely correlated with VAS of pain (p = 0.013) and Beck score for depression (p = 0.016). This study confirmed high prevalence of hypovitaminosis D among in patients with PFMS. This study confirmed the concept that FMS is a risk

  13. Habitat and transmission--effect of tidal level and upstream host density on metacercarial load in an intertidal bivalve.

    PubMed

    Thieltges, D W

    2007-04-01

    Transmission of parasites may be mediated by their habitat, consisting of abiotic and biotic components. I investigated the effect of 2 important habitat components in intertidal ecosystems, tidal level (abiotic) and density of upstream hosts (biotic), on the transmission of trematode cercariae to cockle (Cerastoderma edule) hosts. A field survey showed no general trend in metacercarial loads of cockles regarding tidal level but species-dependent reactions. Parasites originating from Littorina littorea (Himasthla elongata, Renicola roscovita) showed highest infection levels in the low intertidal while parasites originating from Hydrobia ulvae (H. continua, H. interrupta) showed highest infection levels in the mid-intertidal. This reflected the density of upstream hosts at both tidal levels and positive relationships between the density of upstream hosts and metacercarial load in cockles suggested the biotic habitat component to be the dominant factor in transmission. This was confirmed by a field experiment, manipulating tidal level and the density of infected upstream snail hosts. While tidal level had no significant effect on the number of metacercariae of H. elongata acquired by cockles, the effect of upstream host density was strong. In conclusion, although tidal level usually is a very important abiotic habitat component in intertidal ecosystems leading to conspicuous zonation patterns in free-living organisms, it seems of minor importance for trematode transmission. In contrast, the biotic component upstream host density is suggested to be the dominant predictor for trematode transmission to second intermediate hosts. Assessing the relative importance of abiotic and biotic habitat components in transmission is vital for the understanding of transmission processes in the field. PMID:17076926

  14. Immunoassay and Nb2 lymphoma bioassay prolactin levels and mammographic density in premenopausal and postmenopausal women the Nurses' Health Studies.

    PubMed

    Rice, Megan S; Tworoger, Shelley S; Bertrand, Kimberly A; Hankinson, Susan E; Rosner, Bernard A; Feeney, Yvonne B; Clevenger, Charles V; Tamimi, Rulla M

    2015-01-01

    Higher circulating prolactin levels have been associated with higher percent mammographic density among postmenopausal women in some, but not all studies. However, few studies have examined associations with dense area and non-dense breast area breast or considered associations with prolactin Nb2 lymphoma cell bioassay levels. We conducted a cross-sectional study among 1,124 premenopausal and 890 postmenopausal women who were controls in breast cancer case-control studies nested in the Nurses' Health Study (NHS) and NHSII. Participants provided blood samples in 1989-1990 (NHS) or 1996-1999 (NHSII) and mammograms were obtained from around the time of blood draw. Multivariable linear models were used to assess the associations between prolactin levels (measured by immunoassay or bioassay) with percent density, dense area, and non-dense area. Among 1,124 premenopausal women, percent density, dense area, and non-dense area were not associated with prolactin immunoassay levels in multivariable models (p trends = 0.10, 0.18, and 0.69, respectively). Among 890 postmenopausal women, those with prolactin immunoassay levels in the highest versus lowest quartile had modestly, though significantly, higher percent density (difference = 3.01 percentage points, 95 % CI 0.22, 5.80) as well as lower non-dense area (p trend = 0.02). Among women with both immunoassay and bioassay levels, there were no consistent differences in the associations with percent density between bioassay and immunoassay levels. Postmenopausal women with prolactin immunoassay levels in the highest quartile had significantly higher percent density as well as lower non-dense area compared to those in the lowest quartile. Future studies should examine the underlying biologic mechanisms, particularly for non-dense area. PMID:25503962

  15. Immunoassay and Nb2 lymphoma bioassay prolactin levels and mammographic density in premenopausal and postmenopausal women the Nurses’ Health Studies

    PubMed Central

    Rice, Megan S; Tworoger, Shelley S; Bertrand, Kimberly A; Hankinson, Susan E; Rosner, Bernard A; Feeney, Yvonne B; Clevenger, Charles V; Tamimi, Rulla M

    2015-01-01

    Background Higher circulating prolactin levels have been associated with higher percent mammographic density among postmenopausal women in some, but not all studies. However, few studies have examined associations with dense area and non-dense breast area breast or considered associations with prolactin Nb2 lymphoma cell bioassay levels. Methods We conducted a cross-sectional study among 1124 premenopausal and 890 postmenopausal women who were controls in breast cancer case-control studies nested in the Nurses’ Health Study (NHS) and NHSII. Participants provided blood samples in 1989–1990 (NHS) or 1996–1999 (NHSII) and mammograms were obtained from around the time of blood draw. Multivariable linear models were used to assess the associations between prolactin levels (measured by immunoassay or bioassay) with percent density, dense area, and non-dense area. Results Among 1124 premenopausal women, percent density, dense area, and non-dense area were not associated with prolactin immunoassay levels in multivariable models (p-trends=0.10, 0.18, and 0.69, respectively). Among 890 postmenopausal women, those with prolactin immunoassay levels in the highest versus lowest quartile had modestly, though significantly, higher percent density (difference=3.01 percentage points, 95%CI: 0.22, 5.80) as well as lower non-dense area (p-trend=0.02). Among women with both immunoassay and bioassay levels, there were no consistent differences in the associations with percent density between bioassay and immunoassay levels. Conclusions Postmenopausal women with prolactin immunoassay levels in the highest quartile had significantly higher percent density as well as lower non-dense area compared to those in the lowest quartile. Impact Future studies should examine the underlying biologic mechanisms, particularly for non-dense area. PMID:25503962

  16. Retrieval of effective leaf area index (LAIe) and leaf area density (LAD) profile at individual tree level using high density multi-return airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Lin, Yi; West, Geoff

    2016-08-01

    As an important canopy structure indicator, leaf area index (LAI) proved to be of considerable implications for forest ecosystem and ecological studies, and efficient techniques for accurate LAI acquisitions have long been highlighted. Airborne light detection and ranging (LiDAR), often termed as airborne laser scanning (ALS), once was extensively investigated for this task but showed limited performance due to its low sampling density. Now, ALS systems exhibit more competing capacities such as high density and multi-return sampling, and hence, people began to ask the questions like-"can ALS now work better on the task of LAI prediction?" As a re-examination, this study investigated the feasibility of LAI retrievals at the individual tree level based on high density and multi-return ALS, by directly considering the vertical distributions of laser points lying within each tree crown instead of by proposing feature variables such as quantiles involving laser point distribution modes at the plot level. The examination was operated in the case of four tree species (i.e. Picea abies, Pinus sylvestris, Populus tremula and Quercus robur) in a mixed forest, with their LAI-related reference data collected by using static terrestrial laser scanning (TLS). In light of the differences between ALS- and TLS-based LAI characterizations, the methods of voxelization of 3D scattered laser points, effective LAI (LAIe) that does not distinguish branches from canopies and unified cumulative LAI (ucLAI) that is often used to characterize the vertical profiles of crown leaf area densities (LADs) was used; then, the relationships between the ALS- and TLS-derived LAIes were determined, and so did ucLAIs. Tests indicated that the tree-level LAIes for the four tree species can be estimated based on the used airborne LiDAR (R2 = 0.07, 0.26, 0.43 and 0.21, respectively) and their ucLAIs can also be derived. Overall, this study has validated the usage of the contemporary high density multi

  17. Regional lunar gravity anomaly recovery with the GRAIL Level-1b data, and pin-point crustal density estimation with the GRAIL Level-2 and LRO topography data

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Heki, K.

    2014-12-01

    We report the lunar gravity anomaly recovery using the GRAIL Level-1b and Level-2 data, downloaded from the PDS Geoscience Node at the Washington University. First, we used the GNV1b (satellite position data) and KBR1b (inter-satellite ranging data) files of the Level-1b data to estimate the surface mass distribution on the Moon following the method of Sugano and Heki (EPS 2004; GRL 2005). We confirmed that we could recover the gravity anomalies similar to the Level-2 data with spatial resolution of ~0.8 degrees using low altitude portions of the data. Next, we downloaded the GRAIL Level-2 data set (spherical harmonics with degree/order complete to 660) together with the topography data by LRO laser altimetry, and tried to estimate the pin-point surface crustal density. First, we selected a certain square as large as ~60 km, and compared the gravity and topography values at grid points within the square. They are roughly proportional, and the slope provides information on the density of the material making the topography. This method, however, causes apparent positive correlation between density and average topographic height of about 0.2 g/cm^3/km. We (wrongly) assume that the mass anomalies lie on the reference surface. Then, the mass above (below) the reference surface is interpreted heavier/lighter than its real density. We performed a-posteriori correction of the altitude-dependent errors in the estimated density. We finally focus on a few positive gravity anomalies on the nearside (such as those close to the Copernicus crater) that are not associated with any topographic high. We will try to constrain the subsurface structure of the dense material responsible for the anomaly using both Level-1b and -2 data.

  18. Plasma Leptin levels, LEPR Q223R Polymorphism and Mammographic Breast Density: a cross-sectional study

    PubMed Central

    Dallal, Cher; Garte, Seymour; Ragin, Camille; Chen, Jiangying; Lloyd, Stacy; Modugno, Francesmary; Weissfeld, Joel; Taioli, Emanuela

    2015-01-01

    Obesity is associated with breast cancer in post-menopausal women, and breast density is a marker of breast cancer risk. Leptin is produced by the adipose tissue, acts through receptors that are polymorphic in nature, and is considered a cancer growth factor. The relationship between Body Mass Index, leptin, leptin receptors and breast density is not well studied. A cross-sectional analysis in 392 post-menopausal healthy women was conducted; participants provided permission to obtain copies of their most recent screening mammogram. Nonfasting plasma leptin levels were determined using a commercially available leptin ELISA kit. The Q223R genotypes of the LEPR gene were performed by polymerase chain reaction followed by restriction fragment length polymorphism analysis using DNA extracted from buffy coat samples. A statistically significant positive relationship was observed between leptin levels and body mass index (P value<0.0001); leptin was significantly positively associated with mammography total breast area and non-dense breast area (P-value<0.0001), while was significantly inversely associated with percent breast density (P-value<0.0001). Leptin levels varied across the LEPR Q223R polymorphism, and were higher in women homozygous for the AA variant. Percent breast density decreased across the LEPR Q223R genotype, with lower percent density in women with the AA genotype. When dense area was considered for quartiles of leptin by LEPR Q223R, a significant inverse trend between leptin levels and dense breast area was observed only among women with the G/G genotype (P-trend<0.001). After adjustment for possible confounders, leptin levels were significantly inversely associated with percent breast density (p=0.01). A significant interaction between body mass index and leptin levels on percent breast density was observed (p=0.03). These findings suggest that the association between leptin and breast density may vary by LEPR Q223R genotype, and that body mass index

  19. Development of PM2.5 density distribution visualization system using ground-level sensor network and Mie lidar

    NASA Astrophysics Data System (ADS)

    Okumura, Hiroshi; Akaho, Taiga; Kojiro, Yu; Uchino, Osamu; Morino, Isamu; Yokota, Tatsuya; Nagai, Tomohiro; Sakai, Tetsu; Maki, Takashi; Yamazaki, Akihiro; Arai, Kohei

    2014-10-01

    Atmospheric particulate matters (PM) are tiny pieces of solid or liquid matter associated with the Earth's atmosphere. They are suspended in the atmosphere as atmospheric aerosol. Recently, density of fine particles PM2.5, diameter of 2.5 micrometers or less, from China is serious environmental issue in East part of Asia. In this study, the authors have developed a PM2.5 density distribution visualization system using ground-level sensor network dataset and Mie lidar dataset. The former dataset is used for visualization of horizontal PM2.5 density distribution and movement analysis, the latter dataset is used for visualization of vertical PM2.5 density distribution and movement analysis.

  20. Study of bridgewire size and pyrotechnic density relationships on all-fire levels

    SciTech Connect

    Hegedus, S.M.; Munger, A.C.

    1984-01-01

    The effects of bridgewire size and pyrotechnic density on the characteristics of a hot wire test device were evaluated. These characteristics were examined before and during initiation. Five bridgewire diameters and two loading densities were examined. Groups of hot wire devices of each bridgewire and density combination were fabricated. After final assembly, electrothermal response data were obtained on each test device, and a normalizing technique was introduced so that all groups of test devices could be compared. Then, each group of devices was subjected to a Langlie all-fire test to determine the threshold initiation current for each configuration. The results obtained reveal important boundary conditions and limiting factors related to the functioning characteristics of hot-wire devices. This information may be used to develop improved techniques of hot-wire device design such as computer modeling. Further study in this area would be valuable and is warranted.

  1. Air density 2.7 billion years ago limited to less than twice modern levels by fossil raindrop imprints.

    PubMed

    Som, Sanjoy M; Catling, David C; Harnmeijer, Jelte P; Polivka, Peter M; Buick, Roger

    2012-04-19

    According to the 'Faint Young Sun' paradox, during the late Archaean eon a Sun approximately 20% dimmer warmed the early Earth such that it had liquid water and a clement climate. Explanations for this phenomenon have invoked a denser atmosphere that provided warmth by nitrogen pressure broadening or enhanced greenhouse gas concentrations. Such solutions are allowed by geochemical studies and numerical investigations that place approximate concentration limits on Archaean atmospheric gases, including methane, carbon dioxide and oxygen. But no field data constraining ground-level air density and barometric pressure have been reported, leaving the plausibility of these various hypotheses in doubt. Here we show that raindrop imprints in tuffs of the Ventersdorp Supergroup, South Africa, constrain surface air density 2.7 billion years ago to less than twice modern levels. We interpret the raindrop fossils using experiments in which water droplets of known size fall at terminal velocity into fresh and weathered volcanic ash, thus defining a relationship between imprint size and raindrop impact momentum. Fragmentation following raindrop flattening limits raindrop size to a maximum value independent of air density, whereas raindrop terminal velocity varies as the inverse of the square root of air density. If the Archaean raindrops reached the modern maximum measured size, air density must have been less than 2.3 kg m(-3), compared to today's 1.2 kg m(-3), but because such drops rarely occur, air density was more probably below 1.3 kg m(-3). The upper estimate for air density renders the pressure broadening explanation possible, but it is improbable under the likely lower estimates. Our results also disallow the extreme CO(2) levels required for hot Archaean climates. PMID:22456703

  2. Investigation of the effects of nuclear level density parameters on the cross sections for the 234U(γ,f) reaction

    NASA Astrophysics Data System (ADS)

    Pekdogan, Hakan; Aydin, Abdullah; Hakki Sarpun, Ismail

    2015-07-01

    In this study, we have investigated the effects of nuclear level density parameters on the cross sections for the 234U(γ,f) reaction up to 20 MeV. The cross sections on 234U(γ,f) reaction were calculated for different level density models using the TALYS 1.6 code. First, it was determined the level density model that was the closest to the experimental data. Secondly, cross sections obtained for different level density parameters of this model were compared with experimental data from the EXFOR database. Thus it was determined the best level density parameter fit to experimental data.

  3. Final Report Full-Scale Test of DWPF Advanced Liquid-Level and Density Measurement Bubblers

    SciTech Connect

    Duignan, M.R.; Weeks, G.E.

    1999-07-01

    may be too labor intensive for practical use.All of the large diameter bubbler tubes tested could be readily cleaned in place by either blowing them down with justhigh pressure air or water (approx. 90 psig). While the use of both air and water produced the cleanest bubbler, using justair removed most of the slurry build-up, and the use of water resulted in basically a slurry free surface. For the smalldiameter bubbler tubes it was necessary to use high pressure air and water (approx. 90 psig) to effectively clean them. The water was only sent through the porous jacket and not introduced down the air line. However, even under these conditions there was one case where a plug was not removed when both air and water were used.Primary recommendation: The large diameter probe is the best choice since none of the three tested plugged during the2-mouth test period to the point which compromised liquid-level measure. However, after a week`s operation at boilingtemperatures several inches of a soft sludge builds up within the tubes. This sludge can be easily removed in place witheither high pressure air or water (approx. 90 psig). A full-scale verifi-cation test should be carried out in S-area to confirm the conclusion.Secondary recommendation: The small-diameter porous tube bubbler is recommended when an access port cannot accommodate thelarger diameter probe. Bubbler {number_sign}1 operated accurately during most of the test period. This probe had the highest water flowrate (approx. 1.6 gallons/day) and had the least distance from the slurry upper surface (37 inches). This probe can be made to accurately operate at lower depths if the 8-inch-long porous tube is made longer and the water flow rate made higher.Substituting the current level and density probes (Holledge) with bubbler probes will result in a significant cost savings (inexpensive materials, less labor to manufacture, less labor to maintain, less down time due to less frequent instrument replacement).

  4. Comparison of TID Response and SEE Characterization of Single and Multi Level High Density NAND Flash Memories

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.; Harboe-Sorensen, Reno; Virtanen, Ari

    2009-01-01

    Heavy ion single-event measurements and TID response for 8Gb commercial NAND flash memories are reported. Radiation results of multi-level flash technology are compared with results from single-level flash technology. In general, these commercial high density memories appear to be much less susceptible to SEE and have better TID response compared to older generations of flash memories. The charge pump survived up to 600 krads.

  5. The Effects of Text Density Levels and the Cognitive Style of Field Dependence on Learning from a CBI Tutorial

    ERIC Educational Resources Information Center

    Ipek, Ismail

    2011-01-01

    The purpose of this study was to investigate the effects of variations in text density levels and the cognitive style of field dependence on learning from a CBI tutorial, based on the dependent measures of achievement, reading comprehension, and reading rate, and of lesson completion time. Eighty college undergraduate students were randomly…

  6. Performance of a local electron density trigger to select extensive air showers at sea level

    NASA Technical Reports Server (NTRS)

    Abbas, T.; Madani, J.; Ashton, F.

    1985-01-01

    Time coincident voltage pulses in the two closely space (1.6m) plastic scintillators were recorded. Most of the recorded events are expeted to be due to electrons in cosmic ray showers whose core fall at some distance from the detectors. This result is confirmed from a measurement of the frequency distribution of the recorded density ratios of the two scintillators.

  7. Glycated albumin and direct low density lipoprotein cholesterol levels in type 2 diabetes mellitus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diabetes mellitus is a major risk factor for coronary heart disease (CHD), renal failure, retinopathy, and neuropathy. Lowering glycosylated hemoglobin (HbA1c) as well as low-density lipoprotein-cholesterol (LDL-C) has been associated with a decreased risk of these complications. We evaluated the ut...

  8. Direct Low Density Lipoprotein Cholesterol and Glycated Albumin Levels in Type 2 Diabetes Mellitus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diabetes mellitus is a major risk factor for coronary heart disease (CHD), renal failure, retinopathy, and neuropathy. Lowering glycosylated hemoglobin (HbA1c) as well as low-density lipoprotein-cholesterol (LDL-C) have been associated with a decreased risk of these complications. The aim in this st...

  9. A method to measure the density of seawater accurately to the level of 10-6

    NASA Astrophysics Data System (ADS)

    Schmidt, Hannes; Wolf, Henning; Hassel, Egon

    2016-04-01

    A substitution method to measure seawater density relative to pure water density using vibrating tube densimeters was realized and validated. Standard uncertainties of 1 g m-3 at atmospheric pressure, 10 g m-3 up to 10 MPa, and 20 g m-3 to 65 MPa in the temperature range of 5 °C to 35 °C and for salt contents up to 35 g kg-1 were achieved. The realization was validated by comparison measurements with a hydrostatic weighing apparatus for atmospheric pressure. For high pressures, literature values of seawater compressibility were compared with substitution measurements of the realized apparatus.

  10. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    SciTech Connect

    Voinov, Alexander V.; Grimes, Steven M.; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann -Cecilie; Massey, Thomas N.; Siem, Sunniva

    2013-11-08

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys. 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Furthermore, excitation energy dependencies were found to be inconsistent with the Fermi-gas model.

  11. Decrease in plasma high-density lipoprotein cholesterol levels at puberty in boys with delayed adolescence: correlation with plasma testosterone levels

    SciTech Connect

    Kirkland, R.T.; Keenan, B.S.; Probstfield, J.L.; Patsch, W.; Lin, T.L.; Clayton, G.W.; Insull, W. Jr.

    1987-01-23

    A three-phase study tested the hypothesis that the decrease in the high-density lipoprotein cholesterol (HDL-C) level observed in boys at puberty is related to an increase in the plasma testosterone concentration. In phase I, 57 boys aged 10 to 17 years were categorized into four pubertal stages based on clinical parameters and plasma testosterone levels. These four groups showed increasing plasma testosterone values and decreasing HDL-C levels. In phase II, 14 boys with delayed adolescence were treated with testosterone enanthate. Plasma testosterone levels during therapy were in the adult male range. Levels of HDL-C decreased by a mean of 7.4 mg/dL (0.20 mmol/L) and 13.7 mg/dL (0.35 mmol/L), respectively, after the first two doses. In phase III, 13 boys with delayed adolescence demonstrated increasing plasma testosterone levels and decreasing HDL-C levels during spontaneous puberty. Levels of HDL-C and apolipoprotein A-1 were correlated during induced and spontaneous puberty. Testosterone should be considered a significant determinant of plasma HDL-C levels during pubertal development.

  12. Double Trouble at High Density: Cross-Level Test of Resource-Related Adaptive Plasticity and Crowding-Related Fitness

    PubMed Central

    Gergs, André; Preuss, Thomas G.; Palmqvist, Annemette

    2014-01-01

    Population size is often regulated by negative feedback between population density and individual fitness. At high population densities, animals run into double trouble: they might concurrently suffer from overexploitation of resources and also from negative interference among individuals regardless of resource availability, referred to as crowding. Animals are able to adapt to resource shortages by exhibiting a repertoire of life history and physiological plasticities. In addition to resource-related plasticity, crowding might lead to reduced fitness, with consequences for individual life history. We explored how different mechanisms behind resource-related plasticity and crowding-related fitness act independently or together, using the water flea Daphnia magna as a case study. For testing hypotheses related to mechanisms of plasticity and crowding stress across different biological levels, we used an individual-based population model that is based on dynamic energy budget theory. Each of the hypotheses, represented by a sub-model, is based on specific assumptions on how the uptake and allocation of energy are altered under conditions of resource shortage or crowding. For cross-level testing of different hypotheses, we explored how well the sub-models fit individual level data and also how well they predict population dynamics under different conditions of resource availability. Only operating resource-related and crowding-related hypotheses together enabled accurate model predictions of D. magna population dynamics and size structure. Whereas this study showed that various mechanisms might play a role in the negative feedback between population density and individual life history, it also indicated that different density levels might instigate the onset of the different mechanisms. This study provides an example of how the integration of dynamic energy budget theory and individual-based modelling can facilitate the exploration of mechanisms behind the regulation

  13. ASRDI oxygen technology survey. Volume 5: Density and liquid level measurement instrumentation for the cryogenic fluids oxygen, hydrogen, and nitrogen

    NASA Technical Reports Server (NTRS)

    Roder, H. M.

    1974-01-01

    Information is presented on instrumentation for density measurement, liquid level measurement, quantity gauging, and phase measurement. Coverage of existing information directly concerned with oxygen was given primary emphasis. A description of the physical principle of measurement for each instrumentation type is included. The basic materials of construction are listed if available from the source document for each instrument discussed. Cleaning requirements, procedures, and verification techniques are included.

  14. Level density of a Fermi gas and integer partitions: A Gumbel-like finite-size correction

    SciTech Connect

    Roccia, Jerome; Leboeuf, Patricio

    2010-04-15

    We investigate the many-body level density of a gas of noninteracting fermions. We determine its behavior as a function of the temperature and the number of particles. As the temperature increases, and beyond the usual Sommerfeld expansion that describes the degenerate gas behavior, corrections due to a finite number of particles lead to Gumbel-like contributions. We discuss connections with the partition problem in number theory, extreme value statistics, and differences with respect to the Bose gas.

  15. High systemic levels of low-density lipoprotein cholesterol: fuel to the flames in inflammatory osteoarthritis?

    PubMed

    de Munter, Wouter; van der Kraan, Peter M; van den Berg, Wim B; van Lent, Peter L E M

    2016-01-01

    There is increasing evidence that low-density lipoprotein (LDL) cholesterol plays a role in the pathology of OA. Specifically, oxidized LDL (oxLDL), which has been shown to play an essential role during development of atherosclerosis, could be involved in processes such as synovial inflammation, cartilage destruction and bone deformations. OxLDL can activate synovial cells such as macrophages, endothelial cells and synovial fibroblasts, resulting in release of growth factors, MMP and pro-inflammatory cytokines. In this review article, we discuss the role of LDL and oxLDL in OA joint pathology and share our viewpoint of possible mechanisms by which these proteins could influence the development and progression of OA. The proposed theory could provide insight into the aetiopathology of OA and give rise to new potential treatments. PMID:26231344

  16. Level Densities in the actinide region and indirect n,y cross section measurements using the surrogate method

    NASA Astrophysics Data System (ADS)

    Wilson, J. N.; Gunsing, F.; Bernstein, L.; Bürger, A.; Görgen, A.; Thompson, I. J.; Guttormssen, M.; Larsen, A.-C.; Mansouri, P.; Renstrøm, T.; Rose, S. J.; Siem, S.; Wiedeking, M.; Wiborg, T.

    2012-02-01

    Results from a program of measurements of level densities and gamma ray strength functions in the actinide region are presented. Experiments at the Oslo cyclotron involving the Cactus/Siri detectors and 232Th(d,x) and 232Th(3He,x) reactions were carried out to help answer the question of which level density model is the most appropriate for actinide nuclei, since it will have an impact on cross section calculations important for reactor physics simulations. A new technique for extracting level densities and gamma ray strength functions from particle-gamma coincidence data is proposed and results from the development of this technique are presented. In addition, simultaneous measurements of compound nuclear gamma decay probabilities have been performed for the key thorium cycle nuclei 233Th, 231Th and 232Pa up to around 1MeV above the neutron binding energy and have enabled extraction of indirect neutron induced capture cross sections for the 232Th, 231Pa and 230Th nuclei using the surrogate reaction method. Since the neutron capture cross section for 232Th is already well known from direct measurements a comparison provides a stringent test of the applicability of the surrogate technique in the actinide region.

  17. Bone Mineral Density and Vitamin D Level Compared to Lifestyle in Resident Physicians.

    PubMed

    McConda, David B; Boukhemis, Karim W; Matthews, Leslie J; Watkins, Colleen M

    2016-01-01

    Due to the demands of resident education and long periods of time spent indoors, resident physicians may have poorer bone quality than would be expected. Forty-four resident physicians underwent dual-energy X-ray absorptiometry (DEXA) and 25-hydroxyvitamin D level testing at our institution. Results were correlated with a survey of self-reported duty hours, physical activity, and sun exposure. The average 25-hydroxyvitamin D level for all participants was 29 ng/dL, which fell into the insufficient range, and 31.5% of all participants were in the deficient range, with a 25-hydroxyvitamin D level < 20 ng/ dL. For the 40 subjects who underwent DEXA, 17 were found to be osteopenic and three were found to be osteoporotic. Greater awareness of bone health, with routine use of vitamin D supplementation and increased time spent outdoors during peak sunlight hours, may be indicated in this cohort. PMID:27491100

  18. Consistently high plasma high-density lipoprotein-cholesterol levels in children in Spain, a country with low cardiovascular mortality.

    PubMed

    Garcés, Carmen; Gil, Angel; Benavente, Mercedes; Viturro, Enrique; Cano, Beatriz; de Oya, Manuel

    2004-08-01

    Coronary heart disease (CHD) mortality is relatively low in Spain compared with other developed countries and has remained low despite an apparent increase in mean plasma cholesterol concentration in adults over the last several years. It is accepted that pathologic processes related to arteriosclerosis development begin in childhood and seem to be related to the presence of cardiovascular risk factors at this age. High-density lipoprotein-cholesterol (HDL-C) levels in children have been inversely correlated with the incidence of coronary heart disease in the different countries studied. Childhood plasma lipoprotein profile might contribute to the low coronary heart disease mortality in Spain. Thus, we analyzed data on lipid levels over time in schoolchildren in Spain in the last decade. Plasma lipid levels were analyzed in prepuberal children (6 to 8 years) in 3 school-based surveys performed by our group in Madrid in 1987, 1993, and 1999. A significant increase in plasma total cholesterol (P < .05) and low-density lipoprotein-cholesterol (LDL-C) (P < .01) levels in prepuberal children was observed over the last decade. However, the mean concentration of plasma HDL-C remained stable and very high. These high levels of plasma HDL-C in Spanish school children may help to explain why the coronary heart disease mortality rate in Spain is low compared with that in other developed countries. PMID:15281016

  19. Variable density flow in porous media. A study by means of pore level numerical simulations

    NASA Astrophysics Data System (ADS)

    Bouhouch, A.; Prat, M.; Boisson, H.

    1999-07-01

    This paper is devoted to the modelling of isothermal low Reynolds and Mach numbers transient compressible flow through porous media. Traditionally, this type of flow at the macroscopic level is described by the classical Darcy's law combined with a mass balance that includes the transient term. This model is called the classic model. The aim of this paper is to explore the validity of this classic model. To this end, the flow of an ideal gas is considered within two-dimensional model porous media. The flow is due to the imposed pressure variations at the outlet of the fluid domain. At the microscopic level, the flow is computed by solving the full compressible Navier-Stokes equations in two dimensions. Special attention is given to the outlet boundary conditions. The analysis is based on the comparison between the macroscopic data, obtained on the one hand by spatially averaging the microscopic results, and on the other hand by solving the problem directly at the macroscopic level. Situations for which a good agreement is found between the two series of data and situations for which discrepancies are observed are exhibited. These various behaviours are discussed in terms of the various time scales controlling the flow and are explained by analysing the flow structure at pore level. Copyright

  20. Density functional study of patulin at the B3LYP/6-311++G** level

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patulin, a secondary metabolite produced by several fungal species, is a potential contaminant of fruit and vegetable products. Although once investigated for favorable antibiotic properties, the toxicity and concerns of exposure has led to regulation of patulin levels by several countries. To bet...

  1. Oxidized low density lipoprotein increases RANKL level in human vascular cells. Involvement of oxidative stress

    SciTech Connect

    Mazière, Cécile; Salle, Valéry; Gomila, Cathy; Mazière, Jean-Claude

    2013-10-18

    Highlights: •Oxidized LDL enhances RANKL level in human smooth muscle cells. •The effect of OxLDL is mediated by the transcription factor NFAT. •UVA, H{sub 2}O{sub 2} and buthionine sulfoximine also increase RANKL level. •All these effects are observed in human fibroblasts and endothelial cells. -- Abstract: Receptor Activator of NFκB Ligand (RANKL) and its decoy receptor osteoprotegerin (OPG) have been shown to play a role not only in bone remodeling but also in inflammation, arterial calcification and atherosclerotic plaque rupture. In human smooth muscle cells, Cu{sup 2+}-oxidized LDL (CuLDL) 10–50 μg/ml increased reactive oxygen species (ROS) and RANKL level in a dose-dependent manner, whereas OPG level was not affected. The lipid extract of CuLDL reproduced the effects of the whole particle. Vivit, an inhibitor of the transcription factor NFAT, reduced the CuLDL-induced increase in RANKL, whereas PKA and NFκB inhibitors were ineffective. LDL oxidized by myeloperoxidase (MPO-LDL), or other pro-oxidant conditions such as ultraviolet A (UVA) irradiation, incubation with H{sub 2}O{sub 2} or with buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis{sub ,} also induced an oxidative stress and enhanced RANKL level. The increase in RANKL in pro-oxidant conditions was also observed in fibroblasts and endothelial cells. Since RANKL is involved in myocardial inflammation, vascular calcification and plaque rupture, this study highlights a new mechanism whereby OxLDL might, by generation of an oxidative stress, exert a deleterious effect on different cell types of the arterial wall.

  2. Genetically Low Vitamin D Levels, Bone Mineral Density, and Bone Metabolism Markers: a Mendelian Randomisation Study.

    PubMed

    Li, Shan-Shan; Gao, Li-Hong; Zhang, Xiao-Ya; He, Jin-We; Fu, Wen-Zhen; Liu, Yu-Juan; Hu, Yun-Qiu; Zhang, Zhen-Lin

    2016-01-01

    Low serum 25-hydroxyvitamin D (25OHD) is associated with osteoporosis and osteoporotic fracture, but it remains uncertain whether these associations are causal. We conducted a Mendelian randomization (MR) study of 1,824 postmenopausal Chinese women to examine whether the detected associations between serum 25OHD and bone mineral density (BMD) and bone metabolism markers were causal. In observational analyses, total serum 25OHD was positively associated with BMD at lumbar spine (P = 0.003), femoral neck (P = 0.006) and total hip (P = 0.005), and was inversely associated with intact parathyroid hormone (PTH) (P = 8.18E-09) and procollagen type 1 N-terminal propeptide (P1NP) (P = 0.020). By contract, the associations of bioavailable and free 25OHD with all tested outcomes were negligible (all P > 0.05). The use of four single nucleotide polymorphisms, GC-rs2282679, NADSYN1-rs12785878, CYP2R1-rs10741657 and CYP24A1-rs6013897, as candidate instrumental variables in MR analyses showed that none of the two stage least squares models provided evidence for associations between serum 25OHD and either BMD or bone metabolism markers (all P > 0.05). We suggest that after controlling for unidentified confounding factors in MR analyses, the associations between genetically low serum 25OHD and BMD and bone metabolism markers are unlikely to be causal. PMID:27625044

  3. Elevated triglyceride and decreased high density lipoprotein level in carbon disulfide workers in Taiwan.

    PubMed

    Luo, Jiin-Chyuan John; Chang, Ho-Yuan; Chang, Shu-Ju; Chou, Tzu-Chieh; Chen, Chiou-Jong; Shih, Tung-Sheng; Huang, Chin-Chang

    2003-01-01

    Carbon disulfide (CS2) is a man-made product utilized primarily in the manufacture of viscose rayon. Overexposure to CS2 has been associated with an increase in coronary heart disease. The aims of this study were to examine the dose-response relationship of CS2 exposure and elevated lipid profile tests among CS2-exposed workers in Taiwan. A total of 132 workers were recruited from two viscose rayon plants. Air sampling was performed to determine the CS2 exposure of workers. Demographic data and work history were gathered by a standard self-administered questionnaire. Lipid profile tests were also performed by routine methods. The average CS2 exposure concentration was 50.6 +/- 25.6 ppm (range: 24-127 ppm) in the high-exposure group, 12.9 +/- 5 ppm (range: 5.2-22.3 ppm) in the mid-exposure group, and 3.5 +/- 1.2 ppm (range 0.97-5.2 ppm) in the low-exposure group. There were 21 out of 33 (63.7%) elevated triglyceride levels among high-CS2-exposure workers, 27 out of 64 (42.2%) among the middle-CS2-exposure, and 14 out of 35 (40%) among low-CS2-exposure workers, respectively. Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratios (and 95% confidence intervals) of the prevalence of elevated triglyceride value were 1.12 (0.5, 2.7) for middle-CS2-exposure workers, and 2.81 (1.02, 7.8) for high-CS2-exposure workers. There was a significant linear trend between CS2 exposure and the prevalence of elevated triglyceride value (P = 0.046) after adjusting for other factors. There was also a lower prevalence of elevated HDL level in high-CS2-exposure workers than low-CS2-exposure workers (15.2% versus 31.4%). Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratio (and 95% confidence intervals) of elevated HDL level were 0.34 (0.1, 1.18) for high-CS2-exposure workers, which was borderline significant. In conclusion, this study suggests that elevated triglyceride level and decreased HDL level are associated with CS2 exposure

  4. Elevated hepatic lipase activity and low levels of high density lipoprotein in a normotriglyceridemic, nonobese Turkish population.

    PubMed

    Bersot, T P; Vega, G L; Grundy, S M; Palaoglu, K E; Atagündüz, P; Ozbayrakçi, S; Gökdemir, O; Mahley, R W

    1999-03-01

    Low levels of high density lipoprotein cholesterol (HDL-C) are associated with increased risk of coronary heart disease and, in the United States, are often associated with hypertriglyceridemia and obesity. In Turkey, low HDL-C levels are highly prevalent, 53% of men and 26% of women having HDL-C levels <35 mg/dl, in the absence of hypertriglyceridemia and obesity. In this study to investigate the cause of low HDL-C levels in Turks, various factors affecting HDL metabolism were assessed in normotriglyceridemic Turkish men and women living in Istanbul and in non-Turkish men and women living in San Francisco. Turkish men and women had significantly lower HDL-C levels than the San Francisco men and women, as well as markedly lower apolipoprotein A-I levels (25 and 39 mg/dl lower, respectively). In both Turkish and non-Turkish subjects, the mean body mass index was <27 kg/m2, the mean triglyceride level was <120 mg/dl, and the mean total cholesterol was 170-180 mg/dl. The mean hepatic triglyceride lipase activity was 21% and 31% higher in Turkish men and women, respectively, than in non-Turkish men and women, and remained higher even after subjects with a body mass index >50th percentile for men and women in the United States were excluded from the analysis. As no dietary or behavioral factors have been identified in the Turkish population that account for increased hepatic triglyceride lipase activity, the elevation most likely has a genetic basis. high density lipoprotein in a normotriglyceridemic, nonobese Turkish population. PMID:10064731

  5. The clinical significance of preoperative serum cholesterol and high-density lipoprotein-cholesterol levels in hepatocellular carcinoma

    PubMed Central

    Jiang, Shan-Shan; Weng, De-Sheng; Jiang, Long; Zhang, Yao-Jun; Pan, Ke; Pan, Qiu-Zhong; Chen, Chang-Long; Zhao, Jing-Jing; Zhang, Xiao-Fei; Zhang, Hong-Xia; Tang, Yan; Zhou, Zi-Qi; Chen, Min-Shan; Xia, Jian-Chuan

    2016-01-01

    Purpose: To evaluate the prognostic role of the preoperative plasma lipid profile, including low-density lipoprotein -cholesterol [LDL-C], high-density lipoprotein-cholesterol [HDL-C], cholesterol, and triglycerides, in hepatocellular carcinoma patients undergoing radical resection. Methods: Clinical data, including the preoperative plasma profile levels, were retrospectively collected and reviewed in 1411 hepatocellular carcinoma patients, who underwent operation between 2001 and 2010. Kaplan-Meier method and the Cox proportional hazards regression model were used in analyzing the DFS and OS. Results: We found that HDL-C ≤ 0.88 mmol/L and cholesterol ≤ 4.420 mmol/L were preoperative risk factors of disease-free survival (DFS) and overall survival (OS). A decreased CHO level was significantly associated with decreased OS (HR, 0.800; 95% CI, (0.691-0.926), P =0.003) and decreased DFS (HR, 0.844; 95% CI, 0.737-0.966, P=0.012). Additionally, an increased HDL-C level was shown significant association with increased OS (HR, 0.679; 95% CI, 0.570-0.808, P<0.01) and DFS (HR, 2.085; 95% CI, 1.271- 3.422, P = 0.002). In the univariate and multivariate analyses involving OS and DFS, no significant relativity were observed between the LDL-C and TG groups. Conclusions: Decreased levels of CHO and HDL might predict worse outcomes both DFS and OS for hepatocellular carcinoma patients. PMID:27076843

  6. Stress-induced changes in plate density, vail sequences, epeirogeny, and short-lived global sea level fluctuations

    NASA Astrophysics Data System (ADS)

    Cathles, L. M.; Hallam, A.

    1991-08-01

    The stratigraphic record contains clear evidence that broad regions have experienced rapid changes in sea level unrelated to changes in glacial ice volume (e.g., third- and higher-order Vail sea level variations, continental foundering). We propose that many of these changes can be caused by stress-induced changes in plate density. Stress changes produce significant changes in the density of the crust and lithosphere (a point missed in previous investigations) and propagate across even the largest plates in less than 30,000 years. Lithospheric plates interacting at existing boundaries can produce stress-related density changes sufficient to cause several meters change in plate elevation; these may account for many of the regressions and transgressions seen in the stratigraphic record. The creation of new rifts could increase plate compression enough to cause ˜50 m of plate subsidence. Plate elevation changes of up to -200 m could result from increased plate compression during continental collisions. A particularly enigmatic kind of rapid nonglacial global (NGG) sea level change is a coupled ˜50 m sea level fall (regression) and roughly equal rise (transgression) occurring in less than 106 years. These couplets, associated with black shales and marine extinctions, can be explained by the elastic snapback attending the rapid formation of a new rift. Isostatic disequilibria along the new rift depresses the seafloor sufficiently to cause a ˜50 m fall in sea level. Mantle flow restores isostatic equilibrium along the rift axis and erases the fall in ˜60,000 years. Unusually intense hydrothermal circulation along the new rift during the snapback promotes anoxic bottom water conditions and deposition of black shales. A rapid drop in global sea levels reduces the area of ocean bottom within the photic zone, causing overpopulation, food exhaustion, and extinctions. The connections between changes in plate stress and density have many implications. Perhaps the most far

  7. Density and level set-XFEM schemes for topology optimization of 3-D structures

    NASA Astrophysics Data System (ADS)

    Villanueva, Carlos H.; Maute, Kurt

    2014-07-01

    As the capabilities of additive manufacturing techniques increase, topology optimization provides a promising approach to design geometrically sophisticated structures. Traditional topology optimization methods aim at finding conceptual designs, but they often do not resolve sufficiently the geometry and the structural response such that the optimized designs can be directly used for manufacturing. To overcome these limitations, this paper studies the viability of the extended finite element method (XFEM) in combination with the level-set method (LSM) for topology optimization of three dimensional structures. The LSM describes the geometry by defining the nodal level set values via explicit functions of the optimization variables. The structural response is predicted by a generalized version of the XFEM. The LSM-XFEM approach is compared against results from a traditional Solid Isotropic Material with Penalization method for two-phase "solid-void" and "solid-solid" problems. The numerical results demonstrate that the LSM-XFEM approach describes crisply the geometry and predicts the structural response with acceptable accuracy even on coarse meshes.

  8. Variation of DNA Fragmentation Levels During Density Gradient Sperm Selection for Assisted Reproduction Techniques

    PubMed Central

    Muratori, Monica; Tarozzi, Nicoletta; Cambi, Marta; Boni, Luca; Iorio, Anna Lisa; Passaro, Claudia; Luppino, Benedetta; Nadalini, Marco; Marchiani, Sara; Tamburrino, Lara; Forti, Gianni; Maggi, Mario; Baldi, Elisabetta; Borini, Andrea

    2016-01-01

    Abstract Predicting the outcome of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is one main goal of the present research on assisted reproduction. To understand whether density gradient centrifugation (DGC), used to select sperm, can affect sperm DNA integrity and impact pregnancy rate (PR), we prospectively evaluated sperm DNA fragmentation (sDF) by TUNEL/PI, before and after DGC. sDF was studied in a cohort of 90 infertile couples the same day of IVF/ICSI treatment. After DGC, sDF increased in 41 samples (Group A, median sDF value: 29.25% [interquartile range, IQR: 16.01–41.63] in pre- and 60.40% [IQR: 32.92–93.53] in post-DGC) and decreased in 49 (Group B, median sDF value: 18.84% [IQR: 13.70–35.47] in pre- and 8.98% [IQR: 6.24–15.58] in post-DGC). PR was 17.1% and 34.4% in Group A and B, respectively (odds ratio [OR]: 2.58, 95% confidence interval [CI]: 0.95–7.04, P = 0.056). After adjustment for female factor, female and male age and female BMI, the estimated OR increased to 3.12 (95% CI: 1.05–9.27, P = 0.041). According to the subgroup analysis for presence/absence of female factor, heterogeneity in the association between the Group A and B and PR emerged (OR: 4.22, 95% CI: 1.16–15.30 and OR: 1.53, 95% CI: 0.23–10.40, respectively, for couples without, n = 59, and with, n = 31, female factor). This study provides the first evidence that the DGC procedure produces an increase in sDF in about half of the subjects undergoing IVF/ICSI, who then show a much lower probability of pregnancy, raising concerns about the safety of this selection procedure. Evaluation of sDF before and after DGC configures as a possible new prognostic parameter of pregnancy outcome in IVF/ICSI. Alternative sperm selection strategies are recommended for those subjects who undergo the damage after DGC. PMID:27196465

  9. Differential regulation of the β-adrenoceptor density and cyclic AMP level with age and sex in turkey cardiac chambers.

    PubMed

    Hoffmann, Sandra; Böhme, Julia; Kube, Christian; Haufe, Jörg; Krautwald-Junghanns, Maria-Elisabeth; Abraham, Getu

    2016-04-15

    Decreased responses of the heart to β-adrenoceptor stimulation with aging have been shown to occur merely in selected heart chambers in relation to increased catecholamine levels. However, there are no systematic studies that investigate all cardiac chambers with regard to receptor density and cAMP (adenosine 3', 5'-cyclic monophosphate) responses. We used meat-type turkey poults (British United Turkey (B.U.T.) Big 6) with increasing age because their heart seems to decrease in weight in relation to body weight and they are often used as an animal model for heart failure. The receptor density and distribution were quantified by radioligand binding analysis using (-)-[(125)I]-iodocyanopindolol and β-adrenoceptor subtype-specific antagonists (ICI 118.551 and CGP 20712 A) in membranes of four cardiac chambers (right and left atria and ventricles) of 6-week-, 12-week-, 16/21-week-, and 57-week-old B.U.T. BIG 6 turkeys. Receptor function was determined by measuring basal and stimulated cAMP production. In both sexes, the β-adrenoceptor density decreased significantly in all chambers with age without altered β-adrenoceptor subtype distribution. The receptor affinity (KD) to the radioligand was similar in hearts of all age groups. β-adrenoceptor-(isoproterenol and guanosine 5'-triphosphate), G-protein-(NaF) and catalytic unit of adenylate cyclase (forskolin, Mn(2+)) mediated cAMP responses were not chamber-dependent. Indeed, the cAMP level was significantly lower in 57-week-old hearts than in 6-week-, 12-week-, 16/21-week-old hearts. These data suggest that with increasing age and body weight, the β-adrenoceptor signal transduction pathway was highly blunted in all cardiac chambers, occurring by decreased receptor density and cAMP responses. PMID:26957056

  10. Bone mineral density, Bone mineral contents, MMP-8 and MMP-9 levels in Human Mandible and alveolar bone: Simulated microgravity

    NASA Astrophysics Data System (ADS)

    Rai, Balwant; Kaur, Jasdeep; Catalina, Maria

    Exposure to microgravity has been associated with several physiological changes in astronauts and cosmonauts, including an osteoporosis-like loss of bone mass. It has been reported that head-down tilt bed-rest studies mimic many of the observations seen in flights. There is no study on the correlation on effects of mandibular bone and alveolar bone loss in both sex in simulating microgravity. This study was designed to determine the Bone mineral density and GCF MMP-8 MMP-9 in normal healthy subject of both sexes in simulated microgravity condition of -6 head-down-tilt (HDT) bed rest. The subjects of this investigation were 10 male and 10 female volunteers participated in three weeks 6 HDT bed-rest exposure. The Bone density and bone mineral contents were measured by dual energy X-ray absorptiometry before and in simulated microgravity. The GCF MMP-8 MMP-8 were measured by Enzyme-linked immunosorbent assays (Human Quantikine MMP-8,-9 ELISA kit). The bone mineral density and bone mineral contents levels were significantly decreased in simulated microgravity condition in both genders, although insignificantly loss was higher in females as compared to males. MMP-8 MMP-9 levels were significantly increased in simulated microgravity as compared to normal condition although insignificantly higher in females as compared to males. Further study is required on large samples size including all factors effecting in simulated microgravity and microgravity. Keys words-Simulated microgravity condition, head-down-tilt, Bone loss, MMP-8, MMP-9, Bone density, Bone mineral contents.

  11. Znf202 Affects High Density Lipoprotein Cholesterol Levels and Promotes Hepatosteatosis in Hyperlipidemic Mice

    PubMed Central

    Vrins, Carlos L. J.; Out, Ruud; van Santbrink, Peter; van der Zee, André; Mahmoudi, Tokameh; Groenendijk, Martine; Havekes, Louis M.; van Berkel, Theo J. C.; van Dijk, Ko Willems; Biessen, Erik A. L.

    2013-01-01

    Background The zinc finger protein Znf202 is a transcriptional suppressor of lipid related genes and has been linked to hypoalphalipoproteinemia. A functional role of Znf202 in lipid metabolism in vivo still remains to be established. Methodology and Principal Findings We generated mouse Znf202 expression vectors, the functionality of which was established in several in vitro systems. Next, effects of adenoviral znf202 overexpression in vivo were determined in normo- as well as hyperlipidemic mouse models. Znf202 overexpression in mouse hepatoma cells mhAT3F2 resulted in downregulation of members of the Apoe/c1/c2 and Apoa1/c3/a4 gene cluster. The repressive activity of Znf202 was firmly confirmed in an apoE reporter assay and Znf202 responsive elements within the ApoE promoter were identified. Adenoviral Znf202 transfer to Ldlr−/− mice resulted in downregulation of apoe, apoc1, apoa1, and apoc3 within 24 h after gene transfer. Interestingly, key genes in bile flux (abcg5/8 and bsep) and in bile acid synthesis (cyp7a1) were also downregulated. At 5 days post-infection, the expression of the aforementioned genes was normalized, but mice had developed severe hepatosteatosis accompanied by hypercholesterolemia and hypoalphalipoproteinemia. A much milder phenotype was observed in wildtype mice after 5 days of hepatic Znf202 overexpression. Interestingly and similar to Ldl−/− mice, HDL-cholesterol levels in wildtype mice were lowered after hepatic Znf202 overexpression. Conclusion/Significance Znf202 overexpression in vivo reveals an important role of this transcriptional regulator in liver lipid homeostasis, while firmly establishing the proposed key role in the control of HDL levels. PMID:23469003

  12. Macular pigment optical density and its relationship with serum and dietary levels of lutein and zeaxanthin.

    PubMed

    Beatty, Stephen; Nolan, John; Kavanagh, Heather; O'Donovan, Orla

    2004-10-01

    Observational evidence is accumulating that the onset of age-related maculopathy, the leading cause of legal blindness in the Western World, could be delayed, or even averted, with antioxidant supplements. Lutein (L) and zeaxanthin (Z) are two hydroxy-carotenoids with antioxidant activity which accumulate at the macula, where they are collectively known as macular pigment (MP). It has been shown that MP is entirely of dietary origin, and that L and Z levels in serum, diet, and retina correlate. However, the nature of the relationships between L and Z in foodstuffs, blood, and macula is confounded by many variables including processes which influence digestion, absorption, and transport of the compounds in question, and accumulation and stabilization of the carotenoids in the tissues. If macular pigment is protective for age-related maculopathy, a clear understanding of the mechanisms whereby L and Z arrive at the target tissue (retina) from their source (foodstuff) is essential. In this paper, we review the literature germane to this growing area of interest. PMID:15325913

  13. Fine Structure of the Gamow-Teller Resonance in {sup 90}Nb and Level Density of 1{sup +} States

    SciTech Connect

    Kalmykov, Y.; Neumann-Cosel, P. von; Ponomarev, V.Yu.; Richter, A.; Shevchenko, A.; Wambach, J.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Berg, G.P.A.; Fujita, K.; Hatanaka, K.; Kamiya, J.; Nakanishi, K.; Sakamoto, N.; Sakemi, Y.; Shimizu, Y.; Wakasa, T.; Fujita, H.; Smit, F.D.

    2006-01-13

    The fine structure of the Gamow-Teller resonance in a medium-heavy nucleus is observed for the first time in a high-resolution {sup 90}Zr({sup 3}He,t){sup 90}Nb experiment at the Research Center for Nuclear Physics, Osaka. Using a novel wavelet analysis technique, it is possible to extract characteristic energy scales and to quantify their relative importance for the generation of the fine structure. This method combined with the selectivity of the reaction permits an extraction of the level density of 1{sup +} states in {sup 90}Nb.

  14. Measurement of ion current density at ground level in the vicinity of high voltage DC transmission lines

    NASA Astrophysics Data System (ADS)

    McKnight, R. H.; Kotter, F. R.; Misakian, M.

    1981-12-01

    Sensors for measuring vertical current density at ground level near high voltage dc (HVDC) transmission lines are subject to error when the sensor is not in the ground plane. The magnitude of this error, for guarded and unguarded sensors, was investigated using both dc electric fields with space charge and ac electric fields in a parallel plate facility. For conditions like those expected under HVDC transmission lines, the results obtained using ac and dc methods agreed to within experimental uncertainty. The measured errors are as large as 25 percent for guarded sensors and significantly larger for unguarded sensors. Graphs of data for various sensor elevations and guarding are presented.

  15. A predictor of atheroma progression in patients achieving very low levels of low-density lipoprotein cholesterol

    PubMed Central

    Nozue, Tsuyoshi; Yamamoto, Shingo; Tohyama, Shinichi; Fukui, Kazuki; Umezawa, Shigeo; Onishi, Yuko; Kunishima, Tomoyuki; Hibi, Kiyoshi; Terashima, Mitsuyasu; Michishita, Ichiro

    2013-01-01

    An aggressive reduction in low-density lipoprotein cholesterol (LDL-C) with statins produces regression or stabilization of coronary artery plaques. However, after achieving very low levels of LDL-C, atheroma regression is not observed in all patients. The purpose of the present study was to evaluate the determinants of atheroma progression despite achieving very low levels of LDL-C. The effects of 8-month statin therapy on coronary atherosclerosis were evaluated using virtual histology intravascular ultrasound in the TRUTH study. Of these, 33 patients who achieved an on-treatment LDL-C level of <70 mg/dl were divided into 2 groups according to increase in plaque volume (progressors, n= 16) or decrease in plaque volume (regressors, n= 17) during an 8-month follow-up period. At the 8-month follow-up, serum LDL-C and apolipoprotein B levels were significantly lower in progressors than in regressors; however, significant increases in high-density lipoprotein cholesterol and apolipoprotein AI and decreases in high-sensitivity C-reactive protein and oxidized LDL were observed only in regressors. The changes in the n-3 to n-6 polyunsaturated fatty acid ratios significantly differed between the 2 groups. Multivariate regression analysis showed that a decrease in the eicosapentaenoic acid + docosahexaenoic acid/arachidonic acid ratio was a significant predictor associated with atheroma progression (β= -0.512, p= 0.004). In conclusions, n-3 to n-6 polyunsaturated fatty acid ratios affected coronary artery plaque progression and regression in patients who achieved very low levels of LDL-C during statin therapy. PMID:24224137

  16. A predictor of atheroma progression in patients achieving very low levels of low-density lipoprotein cholesterol.

    PubMed

    Nozue, Tsuyoshi; Yamamoto, Shingo; Tohyama, Shinichi; Fukui, Kazuki; Umezawa, Shigeo; Onishi, Yuko; Kunishima, Tomoyuki; Hibi, Kiyoshi; Terashima, Mitsuyasu; Michishita, Ichiro

    2013-01-01

    An aggressive reduction in low-density lipoprotein cholesterol (LDL-C) with statins produces regression or stabilization of coronary artery plaques. However, after achieving very low levels of LDL-C, atheroma regression is not observed in all patients. The purpose of the present study was to evaluate the determinants of atheroma progression despite achieving very low levels of LDL-C. The effects of 8-month statin therapy on coronary atherosclerosis were evaluated using virtual histology intravascular ultrasound in the TRUTH study. Of these, 33 patients who achieved an on-treatment LDL-C level of <70 mg/dl were divided into 2 groups according to increase in plaque volume (progressors, n= 16) or decrease in plaque volume (regressors, n= 17) during an 8-month follow-up period. At the 8-month follow-up, serum LDL-C and apolipoprotein B levels were significantly lower in progressors than in regressors; however, significant increases in high-density lipoprotein cholesterol and apolipoprotein AI and decreases in high-sensitivity C-reactive protein and oxidized LDL were observed only in regressors. The changes in the n-3 to n-6 polyunsaturated fatty acid ratios significantly differed between the 2 groups. Multivariate regression analysis showed that a decrease in the eicosapentaenoic acid + docosahexaenoic acid/arachidonic acid ratio was a significant predictor associated with atheroma progression (β= -0.512, p= 0.004). In conclusions, n-3 to n-6 polyunsaturated fatty acid ratios affected coronary artery plaque progression and regression in patients who achieved very low levels of LDL-C during statin therapy. PMID:24224137

  17. Evaluation of Interspecific Interaction Between Encarsia lutea and Eretomocerus near mundus, the Parasitoids of Cotton Whitefly (Bemisia tabaci) with Host Plants Density Levels and Preference

    NASA Astrophysics Data System (ADS)

    Arshad Ullah, Muhammad; Abbasi, Khalida Hamid; Bano, Saadia; Khanum, Saeeda

    `Studies were carried out at CABI Biosciences Pakistan Centre, Rawalpindi to evaluate the effects of host plants and insects with host density levels and preference by both these species, i.e., Encarsia lutea and Eretomocerus separately as well as together in competitive situation. Preference of density levels by both parasitoids species showed that density level 20 (cotton leaf disc with 20 Bemisia tabaci nymphs and pupae) was contributed more (42%) preference than other density levels (5, 10, 40, 60 and 80). Different density levels had highly significant effect on settlement time of both species separately while in competitive situation the settlement time of both species was not significantly different from each other on different treatments.

  18. Density-dependent effects in experimental larval populations of Anopheles arabiensis (Diptera: Culicidae) can be negative, neutral, or overcompensatory depending on density and diet levels.

    PubMed

    Gilles, J R L; Lees, R S; Soliban, S M; Benedict, M Q

    2011-03-01

    Anopheles arabiensis Patton (Diptera: Culicidae) larvae were reared from hatching to the adult stage in the laboratory under a range of diet and larval concentrations using a factorial design. The range circumscribed most of the larval densities and diet concentrations that would allow larval growth and survival using the particular diet formulation and water volume we tested. We determined how these variables affected three outcomes, as follows: larval development rate, survival, and wing length. As has been reported previously, negative density dependence of survival as a function of increased larval density was the prevalent effect on all outcomes when diet was limiting. When diet was not limiting, density dependence was not observed, and three cases of overcompensatory survival were seen. We discuss these results in the context of diet and larval densities for mass rearing and the effect of larval competition on control strategies. PMID:21485365

  19. Association between soluble lectin-like oxidized low-density lipoprotein receptor 1 levels and coronary slow flow phenomenon

    PubMed Central

    Caglar, Ilker Murat; Ozde, Cem; Caglar, Fatma Nihan Turhan; Akturk, Ibrahim Faruk; Ugurlucan, Murat; Karakaya, Osman

    2016-01-01

    Introduction The coronary slow flow phenomenon (CSFP) has been associated with myocardial ischemia, myocardial infarction, life-threatening arrhythmias, sudden cardiac death and increased cardiovascular mortality similar to coronary artery disease (CAD). Possible underlying mechanisms of CSFP are endothelial dysfunction, chronic inflammation, microvascular dysfunction and diffuse atherosclerosis. Soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) seems to play an important role in the pathogenesis of atherosclerosis. We hypothesized that sLOX-1 might be associated with CSFP, and aimed to research the relationship between sLOX-1 and CSFP. Material and methods Forty patients with angiographically proven CSFP and 43 patients with a normal coronary flow pattern (NCFP) were included in this study. Coronary blood flow was measured according to the Thrombolysis In Myocardial Infarction (TIMI) frame count method. sLOX-1 levels were measured in all study subjects. Results Serum levels of sLOX-1 were significantly higher in the CSFP group than the NCFP group (1061.80 ±422.20 ng/ml vs. 500.043 ±282.97 ng/ml, p < 0.001, respectively). Multivariate logistic regression analysis including sLOX-1, MPV, GGT and uric acid levels revealed a significant association between sLOX-1 levels and CSFP (Exp (B)/OR: 1.006, 95% CI: 1.002–1.010, p = 0.001). Conclusions The present study demonstrated that serum sLOX-1 levels were significantly higher in patients with CSFP and there was a strong association between high sLOX-1 levels and CSFP. High serum sLOX-1 levels may have an important role in the pathogenesis of CSFP. Future studies are needed to confirm these results. PMID:26925116

  20. Systematic review of green tea epigallocatechin gallate in reducing low-density lipoprotein cholesterol levels of humans.

    PubMed

    Momose, Yuko; Maeda-Yamamoto, Mari; Nabetani, Hiroshi

    2016-09-01

    We conducted a systematic review of the literature for the ability of green tea epigallocatechin gallate (EGCG) to lower low-density lipoprotein cholesterol (LDL-C). Study subjects were limited to healthy individuals and randomized, controlled trials on human serum lipid levels, especially LDL-C, conducted. A total of 17 trials (n = 1356) met all of the inclusion criteria. According to weighted mean differences for changes from baseline with 95% confidence intervals (CI), 107-856 mg/d of EGCG for 4 to 14 weeks reduced LDL-C by -9.29 mg/dl (95% CI, -12.27 to -6.31). Sub-analysis was performed to compare the EGCG lowering effect on LDL-C between non-obese and obese subjects, EGCG dose, baseline of LDL-C levels, or BMI. We concluded that consumption of green tea EGCG resulted in a significant reduction of LDL-C at any baseline level and any dose between 107 and 856 mg/d, and the effect size was slightly dependent on the baseline lipid level of the subjects. PMID:27324590

  1. Energy level alignment and quantum conductance of functionalized metal-molecule junctions: Density functional theory versus GW calculations

    SciTech Connect

    Jin, Chengjun; Markussen, Troels; Thygesen, Kristian S.; Strange, Mikkel; Solomon, Gemma C.

    2013-11-14

    We study the effect of functional groups (CH{sub 3}*4, OCH{sub 3}, CH{sub 3}, Cl, CN, F*4) on the electronic transport properties of 1,4-benzenediamine molecular junctions using the non-equilibrium Green function method. Exchange and correlation effects are included at various levels of theory, namely density functional theory (DFT), energy level-corrected DFT (DFT+Σ), Hartree-Fock and the many-body GW approximation. All methods reproduce the expected trends for the energy of the frontier orbitals according to the electron donating or withdrawing character of the substituent group. However, only the GW method predicts the correct ordering of the conductance amongst the molecules. The absolute GW (DFT) conductance is within a factor of two (three) of the experimental values. Correcting the DFT orbital energies by a simple physically motivated scissors operator, Σ, can bring the DFT conductances close to experiments, but does not improve on the relative ordering. We ascribe this to a too strong pinning of the molecular energy levels to the metal Fermi level by DFT which suppresses the variation in orbital energy with functional group.

  2. Relationship between oxidized low-density lipoprotein antibodies and obesity in different glycemic situations

    PubMed Central

    Babakr, Abdullatif Taha; Elsheikh, Osman Mohamed; Almarzouki, Abdullah A; Assiri, Adel Mohamed; Abdalla, Badr Eldin Elsonni; Zaki, Hani Yousif; Fatani, Samir H; NourEldin, EssamEldin Mohamed

    2014-01-01

    Background Autoantibodies to oxidized low-density lipoprotein (oxLDL) are a heterogeneous group of antibodies that are controversially discussed to be either pathogenic or protective. Biochemical and anthropometric measurements correlated with increased levels of these antibodies are also controversial, especially in conditions of impaired glucose tolerance and type 2 diabetes mellitus. The present study was conducted to evaluate levels of oxLDL antibodies and their correlation with obesity in different glycemic situations. Methods Two hundred and seventy-four adult males were classified into three subgroups: group 1 (n=125), comprising a control group of nondiabetic subjects; group 2 (n=77), comprising subjects with impaired glucose tolerance; and group 3 (n=72), comprising patients with type 2 diabetes mellitus. Body mass index was calculated, and measurement of oxLDL and oxLDL antibodies was performed. Results Higher mean concentrations of oxLDL were found in the type 2 diabetes mellitus and impaired glucose tolerance groups (143.5±21.9 U/L and 108.7±23.7 U/L, respectively). The mean value for the control group was 73.5±27.5 U/L (P<0.001). Higher mean concentrations of anti-oxLDL antibodies were observed in the type 2 diabetes mellitus and impaired glucose tolerance groups (55.7±17.8 U/L and 40.4±17.6 U/L, respectively). The mean value for the control group was 20.4±10 U/L (P<0.001). Levels of anti-oxLDL antibodies were found to be positively and significantly correlated with body mass index in the control group (r=0.46), impaired glucose tolerance (r=0.51), type 2 diabetes mellitus group (r=0.46), and in the whole study population (r=0.44; P<0.001). Conclusion Anti-oxLDL antibody levels were increased in subjects with type 2 diabetes mellitus and impaired glucose tolerance and were positively correlated with obesity and body mass index. PMID:25368528

  3. Reconstituted high-density lipoproteins acutely reduce soluble brain Aβ levels in symptomatic APP/PS1 mice.

    PubMed

    Robert, Jérôme; Stukas, Sophie; Button, Emily; Cheng, Wai Hang; Lee, Michael; Fan, Jianjia; Wilkinson, Anna; Kulic, Iva; Wright, Samuel D; Wellington, Cheryl L

    2016-05-01

    Many lines of evidence suggest a protective role for high-density lipoprotein (HDL) and its major apolipoprotein (apo)A-I in Alzheimer's Disease (AD). HDL/apoA-I particles are produced by the liver and intestine and, in addition to removing excess cholesterol from the body, are increasingly recognized to have vasoprotective functions. Here we tested the ability of reconstituted HDL (rHDL) consisting of human apoA-I reconstituted with soy phosphatidylcholine for its ability to lower amyloid beta (Aβ) levels in symptomatic APP/PS1 mice, a well-characterized preclinical model of amyloidosis. Animals were treated intravenously either with four weekly doses (chronic study) or a single dose of 60mg/kg of rHDL (acute study). The major finding of our acute study is that soluble brain Aβ40 and Aβ42 levels were significantly reduced within 24h of a single dose of rHDL. By contrast, no changes were observed in our chronic study with respect to soluble or deposited Aβ levels in animals assessed 7days after the final weekly dose of rHDL, suggesting that beneficial effects diminish as rHDL is cleared from the body. Further, rHDL-treated animals showed no change in amyloid burden, cerebrospinal fluid (CSF) Aβ levels, neuroinflammation, or endothelial activation in the chronic study, suggesting that the pathology-modifying effects of rHDL may indeed be acute and may be specific to the soluble Aβ pool. That systemic administration of rHDL can acutely modify brain Aβ levels provides support for further investigation of the therapeutic potential of apoA-I-based agents for AD. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock. PMID:26454209

  4. Inoculation density and nutrient level determine the formation of mushroom-shaped structures in Pseudomonas aeruginosa biofilms.

    PubMed

    Ghanbari, Azadeh; Dehghany, Jaber; Schwebs, Timo; Müsken, Mathias; Häussler, Susanne; Meyer-Hermann, Michael

    2016-01-01

    Pseudomonas aeruginosa often colonises immunocompromised patients and the lungs of cystic fibrosis patients. It exhibits resistance to many antibiotics by forming biofilms, which makes it hard to eliminate. P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology. This study provides an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model relies on recently published experimental data. Our simulations show colony formation by immotile cells. Motile cells escape from a single colony by nutrient chemotaxis and hence no mushroom shape develops. A high number density of non-motile colonies leads to migration of motile cells onto the top of the colonies and formation of mushroom-shaped structures. This model proposes that the formation of mushroom-shaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors. PMID:27611778

  5. Removal of salt from high-level waste tanks by density-driven circulation or mechanical agitation

    SciTech Connect

    Kiser, D.L.

    1981-01-01

    Twenty-two high-level waste storage tanks at the Savannah River Plant are to be retired in the tank replacement/waste transfer program. The salt-removal portion of this program requires dissolution of about 19 million liters of salt cake. Steam circulation jets were originally proposed to dissolve the salt cake. However, the jets heated the waste tank to 80 to 90/sup 0/C. This high temperature required a long cooldown period before transfer of the supernate by jet, and increased the risk of stress-corrosion cracking in these older tanks. A bench-scale investigation at the Savannah River Laboratory developed two alternatives to steam-jet circulation. One technique was density-driven circulation, which in bench tests dissolved salt at the same rate as a simulated steam circulation jet but at a lower temperature. The other technique was mechanical agitation, which dissolved the salt cake faster and required less fresh water than either density-driven circulation or the simulated steam circulation jet. Tests in an actual waste tank verified bench-scale results and demonstrated the superiority of mechanical agitation.

  6. Inoculation density and nutrient level determine the formation of mushroom-shaped structures in Pseudomonas aeruginosa biofilms

    PubMed Central

    Ghanbari, Azadeh; Dehghany, Jaber; Schwebs, Timo; Müsken, Mathias; Häussler, Susanne; Meyer-Hermann, Michael

    2016-01-01

    Pseudomonas aeruginosa often colonises immunocompromised patients and the lungs of cystic fibrosis patients. It exhibits resistance to many antibiotics by forming biofilms, which makes it hard to eliminate. P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology. This study provides an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model relies on recently published experimental data. Our simulations show colony formation by immotile cells. Motile cells escape from a single colony by nutrient chemotaxis and hence no mushroom shape develops. A high number density of non-motile colonies leads to migration of motile cells onto the top of the colonies and formation of mushroom-shaped structures. This model proposes that the formation of mushroom-shaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors. PMID:27611778

  7. Relationship of serum GDF11 levels with bone mineral density and bone turnover markers in postmenopausal Chinese women.

    PubMed

    Chen, Yusi; Guo, Qi; Zhang, Min; Song, Shumin; Quan, Tonggui; Zhao, Tiepeng; Li, Hongliang; Guo, Lijuan; Jiang, Tiejian; Wang, Guangwei

    2016-01-01

    Growth differentiation factor 11 (GDF11) is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the relationship between serum GDF11 level, bone mass, and bone turnover markers in postmenopausal Chinese women. Serum GDF11 level, bone turnover biochemical markers, and bone mineral density (BMD) were determined in 169 postmenopausal Chinese women (47-78 years old). GDF11 serum levels increased with aging. There were negative correlations between GDF11 and BMD at the various skeletal sites. After adjusting for age and body mass index (BMI), the correlations remained statistically significant. In the multiple linear stepwise regression analysis, age or years since menopause, BMI, GDF11, and estradiol were independent predictors of BMD. A significant negative correlation between GDF11 and bone alkaline phosphatase (BAP) was identified and remained significant after adjusting for age and BMI. No significant correlation was noted between cross-linked N-telopeptides of type I collagen (NTX) and GDF11. In conclusion, GDF11 is an independent negative predictor of BMD and correlates with a biomarker of bone formation, BAP, in postmenopausal Chinese women. GDF11 potentially exerts a negative effect on bone mass by regulating bone formation. PMID:27408764

  8. Pigeons: A Novel GUI Software for Analysing and Parsing High Density Heterologous Oligonucleotide Microarray Probe Level Data

    PubMed Central

    Lai, Hung-Ming; May, Sean T.; Mayes, Sean

    2014-01-01

    Genomic DNA-based probe selection by using high density oligonucleotide arrays has recently been applied to heterologous species (Xspecies). With the advent of this new approach, researchers are able to study the genome and transcriptome of a non-model or an underutilised crop species through current state-of-the-art microarray platforms. However, a software package with a graphical user interface (GUI) to analyse and parse the oligonucleotide probe pair level data is still lacking when an experiment is designed on the basis of this cross species approach. A novel computer program called Pigeons has been developed for customised array data analysis to allow the user to import and analyse Affymetrix GeneChip® probe level data through XSpecies. One can determine empirical boundaries for removing poor probes based on genomic hybridisation of the test species to the Xspecies array, followed by making a species-specific Chip Description File (CDF) file for transcriptomics in the heterologous species, or Pigeons can be used to examine an experimental design to identify potential Single-Feature Polymorphisms (SFPs) at the DNA or RNA level. Pigeons is also focused around visualization and interactive analysis of the datasets. The software with its manual (the current release number version 1.2.1) is freely available at the website of the Nottingham Arabidopsis Stock Centre (NASC).

  9. Effects of ultrasound on estradiol level, bone mineral density, bone biomechanics and matrix metalloproteinase-13 expression in ovariectomized rabbits

    PubMed Central

    XIA, LU; HE, HONGCHEN; GUO, HUA; QING, YUXI; HE, CHENG-QI

    2015-01-01

    The aim of the present study was to observe the effect of ultrasound (US) on estradiol level, bone mineral density (BMD), bone biomechanics and matrix metalloproteinase-13 (MMP-13) expression in ovariectomized (OVX) rabbits. A total of 28 virgin New Zealand white rabbits were randomly assigned into the following groups: Control (control group), ovariectomy (OVX group), ovariectomy with ultrasound therapy (US group) and ovariectomy with estrogen replacement therapy group (ERT group). At 8 weeks after ovariectomy, the US group received ultrasound treatment while the ERT group were orally treated with conjugated estrogens, and the control and OVX groups remained untreated. The estradiol level, BMD and bone biomechanics, cartilage histology and the MMP-13 expression were analyzed after the intervention. The results indicate that the US treatment increased estradiol level, BMD and bone biomechanical function. Furthermore, the US treatment appeared to improve the recovery of cartilage morphology and decreased the expression of MMP-13 in OVX models. Furthermore, the results suggest that 10 days of US therapy was sufficient to prevent the reduction of estradiol, BMD and bone biomechanical function, to protect osteoarthritis cartilage structure, and to reduce MMP-13 transcription and expression in OVX rabbits. Therefore, US treatment may be a potential treatment for postmenopausal osteoarthritis and osteoporosis. PMID:26622502

  10. Relationship of serum GDF11 levels with bone mineral density and bone turnover markers in postmenopausal Chinese women

    PubMed Central

    Chen, Yusi; Guo, Qi; Zhang, Min; Song, Shumin; Quan, Tonggui; Zhao, Tiepeng; Li, Hongliang; Guo, Lijuan; Jiang, Tiejian; Wang, Guangwei

    2016-01-01

    Growth differentiation factor 11 (GDF11) is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the relationship between serum GDF11 level, bone mass, and bone turnover markers in postmenopausal Chinese women. Serum GDF11 level, bone turnover biochemical markers, and bone mineral density (BMD) were determined in 169 postmenopausal Chinese women (47–78 years old). GDF11 serum levels increased with aging. There were negative correlations between GDF11 and BMD at the various skeletal sites. After adjusting for age and body mass index (BMI), the correlations remained statistically significant. In the multiple linear stepwise regression analysis, age or years since menopause, BMI, GDF11, and estradiol were independent predictors of BMD. A significant negative correlation between GDF11 and bone alkaline phosphatase (BAP) was identified and remained significant after adjusting for age and BMI. No significant correlation was noted between cross-linked N-telopeptides of type I collagen (NTX) and GDF11. In conclusion, GDF11 is an independent negative predictor of BMD and correlates with a biomarker of bone formation, BAP, in postmenopausal Chinese women. GDF11 potentially exerts a negative effect on bone mass by regulating bone formation. PMID:27408764

  11. Gamma densitometer for measuring Pu density in fuel tubes

    SciTech Connect

    Winn, W.G.

    1982-01-01

    A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is ..gamma..-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV ..gamma..-ray from /sup 237/U (7d) of the /sup 241/Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of the 0.133- to 0.183-inch-thick tube walls. Each measurement yields a density ratio that relates the plutonium density of the measured area to the plutonium density in normal regions of the tube. The technique was used to appraise a series of fuel tubes to be irradated in an SRP reactor. High-density plutonium areas were initially identified by x-ray methods and then examined quantitatively with the FGD. The FGD reliably tested fuel tubes and yielded density ratios over a range of 0.0 to 2.5. FGD measurements examined (1) nonuniform plutonium densities or hot spots, (2) uniform high-density patches, and (3) plutonium density distribution in thin cladding regions. Measurements for tubes with known plutonium density agreed with predictions to within 2%. Attenuation measurements of the 208-keV ..gamma..-ray passage through the tube walls agreed to within 2 to 3% of calculated predictions. Collimator leakage measurements agreed with model calculations that predicted less than a 1.5% effect on plutonium density ratios. Finally, FGD measurements correlated well with x-ray transmission and fluoroscopic measurements. The data analysis for density ratios involved a small correction of about 10% for ..gamma..-shielding within the fuel tube. For hot spot examinations, limited information for this correction dictated a density ratio uncertainty of 3 to 5%.

  12. In vivo effects of 17-β-estradiol on plasma immunoglobulin levels and leukocyte density in zebrafish Danio rerio

    NASA Astrophysics Data System (ADS)

    Li, Lei; Zhang, Shicui; Tong, Zhou; Liu, Jia

    2010-05-01

    Estradiol, or 17-β-estradiol (E2), the most potent naturally occurring estrogen, is involved in the hormone-immune system interaction in both mammals and fish. However, in vivo studies are largely limited, and little is known about whether E2 exerts similar effects on both female and male zebrafish ( Danio rerio). Here, we show exposure of both sexes of D. rerio to 20 nmol/L E2 resulted in a significant increase in Vg1 expression, but caused little damage to the hepatocytes, suggesting that this is the optimum E2 concentration. Also, exposure to 20 nmol/L E2 for 20 days caused a marked increase in plasma IgM levels, but had little influence on the peripheral leukocyte density, providing the first evidence of a hormone-immune system interaction in this species.

  13. Probing the density of states of two-level tunneling systems in silicon oxide films using superconducting lumped element resonators

    SciTech Connect

    Skacel, S. T.; Kaiser, Ch.; Wuensch, S.; Siegel, M.; Rotzinger, H.; Lukashenko, A.; Jerger, M.; Weiss, G.; Ustinov, A. V.

    2015-01-12

    We have investigated dielectric losses in amorphous silicon oxide (a-SiO) thin films under operating conditions of superconducting qubits (mK temperatures and low microwave powers). For this purpose, we have developed a broadband measurement setup employing multiplexed lumped element resonators using a broadband power combiner and a low-noise amplifier. The measured temperature and power dependences of the dielectric losses are in good agreement with those predicted for atomic two-level tunneling systems (TLS). By measuring the losses at different frequencies, we found that the TLS density of states is energy dependent. This had not been seen previously in loss measurements. These results contribute to a better understanding of decoherence effects in superconducting qubits and suggest a possibility to minimize TLS-related decoherence by reducing the qubit operation frequency.

  14. WDR1 and CLNK gene polymorphisms correlate with serum glucose and high-density lipoprotein levels in Tibetan gout patients.

    PubMed

    Lan, Bing; Chen, Peng; Jiri, Mutu; He, Na; Feng, Tian; Liu, Kai; Jin, Tianbo; Kang, Longli

    2016-03-01

    Current evidence suggests heredity and metabolic syndrome contributes to gout progression. Specifically, the WDR1 and CLNK genes may play a role in gout progression in European ancestry populations. However, no studies have focused on Chinese populations, especially Tibetan individuals. This study aims to determine whether variations in these two genes correlate with gout-related indices in Chinese-Tibetan gout patients. Eleven single-nucleotide polymorphisms in the WDR1 and CLNK genes were detected in 319 Chinese-Tibetan gout patients and 318 controls. We used one-way analysis of variance to evaluate the polymorphisms' effects on gout based on mean serum levels of metabolism indicators, such as albumin, glucose (GLU), triglycerides, cholesterol, high-density lipoproteins (HDL-C), creatinine, and uric acid, from fasting venous blood samples. All p values were Bonferroni corrected. Polymorphisms of the WDR1 and CLNK genes affected multiple risk factors for gout development. Significant differences in serum GLU levels were detected between different genotypic groups with WDRI polymorphisms rs4604059 (p = 0.005) and rs12498927 (p = 0.005). In addition, significant differences in serum HDL-C levels were detected between different genotypic groups with the CLNK polymorphism rs2041215 (p = 0.001). Polymorphisms of CLNK also affected levels of albumin, triglycerides, and creatinine. This study is the first to investigate and identify positive correlations between WDR1 and CLNK gene polymorphisms in Chinese-Tibetan populations. Our findings provide significant evidence for the effect of genetic polymorphisms on gout-related factors in Chinese-Tibetan populations. PMID:26438387

  15. The importance of low serum levels of high-density lipoprotein cholesterol (HDL-C) as a cardiovascular risk factor.

    PubMed

    Espinosa-Larrañaga, Francisco; Vejar-Jalaf, Margarita; Medina-Santillán, Roberto

    2005-10-01

    In order to discuss and establish a joint position on the treatment of low serum levels of high-density lipoprotein cholesterol (HDL-C), a group of experts involved in the care of people with dyslipidaemia and at risk of cardiovascular disease met in Miami, Florida, U.S., on 5th and 6th March 2005. The experts came from the Latin American countries Argentina, Brazil, Chile, Colombia, Ecuador, Guatemala, Mexico and Venezuela and had at least five years of experience in the care of patients with dyslipidaemia and low HDL-C. The main objective of the meeting was to discuss and propose a treatment for low serum HDL-C levels as a cardiovascular risk factor in patients and to create a group of useful recommendations in this regard, applicable to the daily clinical practice of physicians dealing with patients with dyslipidaemia and cardiovascular disease. This document describes the methodology developed to obtain these recommendations and presents the results of this academic meeting. PMID:16342610

  16. Relationship between Body Mass Composition, Bone Mineral Density, Skin Fibrosis and 25(OH) Vitamin D Serum Levels in Systemic Sclerosis.

    PubMed

    Corrado, Addolorata; Colia, Ripalta; Mele, Angiola; Di Bello, Valeria; Trotta, Antonello; Neve, Anna; Cantatore, Francesco Paolo

    2015-01-01

    A reduced bone mineral density (BMD) is observed in several rheumatic autoimmune diseases, including Systemic Sclerosis (SSc); nevertheless, data concerning the possible determinants of bone loss in this disease are not fully investigated. The aim of this study is to evaluate the relationship between BMD, body mass composition, skin sclerosis and serum Vitamin D levels in two subsets of SSc patients. 64 post-menopausal SSc patients, classified as limited cutaneous (lcSSc) or diffuse cutaneous (dcSSc) SSc, were studied. As control, 35 healthy post-menopausal women were recruited. Clinical parameters were evaluated, including the extent of skin involvement. BMD at lumbar spine, hip, femoral neck and body mass composition were determined by dual-energy X-ray absorptiometry. Serum calcium, phosphorus, alkaline phosphatase, urine pyridinium cross-links, intact parathyroid hormone and 25-hydroxyvitamin D (25OHD) were measured. BMD at spine, femoral neck and total hip was significantly lower in SSc patients compared to controls. In dcSSc subset, BMD at spine, femoral neck and total hip was significantly lower compared to lcSSc. No differences in both fat and lean mass were found in the three study groups even if patients with dcSSc showed a slightly lower total body mass compared to healthy controls. Total mineral content was significantly reduced in dSSc compared to both healthy subjects and lcSSc group. Hypovitaminosis D was observed both in healthy post-menopausal women and in SSc patients, but 25OHD levels were significantly lower in dcSSc compared to lcSSc and inversely correlated with the extent of skin thickness. These results support the hypothesis that the extent of skin involvement in SSc patients could be an important factor in determining low circulating levels of 25OHD, which in turn could play a significant role in the reduction of BMD and total mineral content. PMID:26375284

  17. Relationship between Body Mass Composition, Bone Mineral Density, Skin Fibrosis and 25(OH) Vitamin D Serum Levels in Systemic Sclerosis

    PubMed Central

    Corrado, Addolorata; Colia, Ripalta; Mele, Angiola; Di Bello, Valeria; Trotta, Antonello; Neve, Anna; Cantatore, Francesco Paolo

    2015-01-01

    A reduced bone mineral density (BMD) is observed in several rheumatic autoimmune diseases, including Systemic Sclerosis (SSc); nevertheless, data concerning the possible determinants of bone loss in this disease are not fully investigated. The aim of this study is to evaluate the relationship between BMD, body mass composition, skin sclerosis and serum Vitamin D levels in two subsets of SSc patients. 64 post-menopausal SSc patients, classified as limited cutaneous (lcSSc) or diffuse cutaneous (dcSSc) SSc, were studied. As control, 35 healthy post-menopausal women were recruited. Clinical parameters were evaluated, including the extent of skin involvement. BMD at lumbar spine, hip, femoral neck and body mass composition were determined by dual-energy X-ray absorptiometry. Serum calcium, phosphorus, alkaline phosphatase, urine pyridinium cross-links, intact parathyroid hormone and 25-hydroxyvitamin D (25OHD) were measured. BMD at spine, femoral neck and total hip was significantly lower in SSc patients compared to controls. In dcSSc subset, BMD at spine, femoral neck and total hip was significantly lower compared to lcSSc. No differences in both fat and lean mass were found in the three study groups even if patients with dcSSc showed a slightly lower total body mass compared to healthy controls. Total mineral content was significantly reduced in dSSc compared to both healthy subjects and lcSSc group. Hypovitaminosis D was observed both in healthy post-menopausal women and in SSc patients, but 25OHD levels were significantly lower in dcSSc compared to lcSSc and inversely correlated with the extent of skin thickness. These results support the hypothesis that the extent of skin involvement in SSc patients could be an important factor in determining low circulating levels of 25OHD, which in turn could play a significant role in the reduction of BMD and total mineral content. PMID:26375284

  18. Correlating the Local Defect-Level Density with the Macroscopic Composition and Energetics of Chalcopyrite Thin-Film Surfaces.

    PubMed

    Bröker, Sebastian; Kück, Dennis; Timmer, Alexander; Lauermann, Iver; Ümsür, Bünyamin; Greiner, Dieter; Kaufmann, Christian A; Mönig, Harry

    2015-06-17

    The unusual defect chemistry of polycrystalline Cu(In,Ga)Se2 (CIGSe) thin films is a main issue for a profound understanding of recombination losses in chalcopyrite thin-film solar cells. Especially, impurity-driven passivation of electronic levels due to point defects segregating at the surface and at grain boundaries is extensively debated. By combining current imaging tunneling spectroscopy with photoelectron spectroscopy, the local defect-level density and unusual optoelectronic grain-boundary properties of this material are correlated with the macroscopic energy levels and surface composition. Vacuum annealing of different CIGSe materials provides evidence that Na diffusion from the glass substrate does not affect the surface defect passivation or grain-boundary properties of standard Cu-poor materials. Furthermore, we find no major impact on the observed thermally activated dipole compensation or the accompanying change in surface band bending (up to 0.6 eV) due to Na. In contrast, Cu-rich CIGSe shows an opposing surface defect chemistry with only minor heat-induced band bending. Our results lead to a comprehensive picture, where the highly desirable type inversion at the p/n interface in standard chalcopyrite thin-film solar cells is dominated by band bending within the CIGSe absorber rather than the result of Na impurities or an n-type defect phase segregating at the interface. This is in accordance with recent studies suggesting a surface reconstruction as the origin for Cu depletion and band-gap widening at the surface of chalcopyrite thin films. PMID:26010380

  19. Hydroxytyrosol in functional hydroxytyrosol-enriched biscuits is highly bioavailable and decreases oxidised low density lipoprotein levels in humans.

    PubMed

    Mateos, Raquel; Martínez-López, Sara; Baeza Arévalo, Gema; Amigo-Benavent, Miryam; Sarriá, Beatriz; Bravo-Clemente, Laura

    2016-08-15

    Hydroxytyrosol (HT) and its derivatives in olive oil protect low-density lipoproteins (LDL) against oxidation. Biscuits could be a convenient alternative to broaden consumers' choice of HT-rich foods, although the biscuit matrix could affect HT bioavailability. We performed a crossover, randomized, double-blind study to evaluate HT bioavailability in HT-enriched biscuits (HT-B) versus non-enriched biscuits (C-B), and the effects on oxidative postprandial status. On two separate days, 13 subjects consumed 30 g of C-B or HT-B (5.25mg HT) after overnight-fasting. Blood and urine were collected at different intervals and analysed by LC-MS-QToF. After HT-B consumption, plasma metabolites peaked between 0.5 and 1h and were extensively excreted in urine. HT-sulphate and 3,4-dihydroxyphenylacetic acid (DOPAC)-sulphate were the main metabolites, followed by DOPAC and homovanillic acid (HVA). HT-glucuronide, DOPAC-glucuronide, HVA-glucuronide and HVA-sulphate were also detected. Postprandial oxidised-LDL concentrations decreased with HT-B. HT is a promising functional ingredient and, in biscuits, it is highly bioavailable and lowers postprandial oxidised-LDL levels. PMID:27006237

  20. Consequences of seasonal variation in reservoir water level for predatory fishes: linking visual foraging and prey densities

    USGS Publications Warehouse

    Klobucar, Stephen L.; Budy, Phaedra

    2016-01-01

    In reservoirs, seasonal drawdown can alter the physical environment and may influence predatory fish performance. We investigated the performance of lake trout (Salvelinus namaycush) in a western reservoir by coupling field measurements with visual foraging and bioenergetic models at four distinct states (early summer, mid-summer, late summer, and fall). The models suggested that lake trout prey, juvenile kokanee (Oncorhynchus nerka), are limited seasonally by suitable temperature and dissolved oxygen. Accordingly, prey densities were greatest in late summer when reservoir volume was lowest and fish were concentrated by stratification. Prey encounter rates (up to 68 fish·day−1) and predator consumption are also predicted to be greatest during late summer. However, our models suggested that turbidity negatively correlates with prey detection and consumption across reservoir states. Under the most turbid conditions, lake trout did not meet physiological demands; however, during less turbid periods, predator consumption reached maximum bioenergetic efficiency. Overall, our findings demonstrate that rapid reservoir fluctuations and associated abiotic conditions can influence predator–prey interactions, and our models describe the potential impacts of water level fluctuation on valuable sport fishes.

  1. Exact density of states for lowest Landau level in white noise potential superfield representation for interacting systems

    NASA Astrophysics Data System (ADS)

    Wegner, Franz

    1983-12-01

    The density of states of two-dimensional electrons in a strong perpendicular magnetic field and white-noise potential is calculated exactly under the provision that only the states of the free electrons in the lowest Landau level are taken into account. It is used that the integral over the coordinates in the plane perpendicular to the magnetic field in a Feynman graph yields the inverse of the number λ of Euler trails through the graph, whereas the weight by which a Feynman graph contributes in this disordered system is λ times that of the corresponding interacting system. Thus the factors λ cancel which allows the reduction of the d dimensional disordered problem to a ( d-2) dimensional φ4 interaction problem. The inverse procedure and the equivalence of disordered harmonic systems with interacting systems of superfields is used to give a mapping of interacting systems with U(1) invariance in d dimensions to interacting systems with UPL(1,1) invariance in ( d+2) dimensions. The partition function of the new systems is unity so that systems with quenched disorder can be treated by averaging exp(- H) without recourse to the replica trick.

  2. Combined effects of endogenous sex hormone levels and mammographic density on postmenopausal breast cancer risk: results from the Breakthrough Generations Study

    PubMed Central

    Schoemaker, M J; Folkerd, E J; Jones, M E; Rae, M; Allen, S; Ashworth, A; Dowsett, M; Swerdlow, A J

    2014-01-01

    Background: Mammographic density and sex hormone levels are strong risk factors for breast cancer, but it is unclear whether they represent the same aetiological entity or are independent risk factors. Methods: Within the Breakthrough Generations Study cohort, we conducted a case–control study of 265 postmenopausal breast cancer cases and 343 controls with prediagnostic mammograms and blood samples. Plasma was assayed for oestradiol, testosterone and sex hormone-binding globulin (SHBG) concentrations and mammographic density assessed by Cumulus. Results: Oestradiol and testosterone were negatively and SHBG positively associated with percentage density and absolute dense area, but after adjusting for body mass index the associations remained significant only for SHBG. Breast cancer risk was independently and significantly positively associated with percentage density (P=0.002), oestradiol (P=0.002) and testosterone (P=0.007) levels. Women in the highest tertile of both density and sex hormone level were at greatest risk, with an odds ratio of 7.81 (95% confidence interval (CI): 2.89–21.1) for oestradiol and 4.57 (95% CI: 1.75–11.9) for testosterone and high density compared with those who were in the lowest tertiles. The cumulative risk of breast cancer in the highest oestradiol and density tertiles, representing 8% of controls, was estimated as 12.8% at ages 50–69 years and 19.4% at ages 20–79 years, and in the lowest tertiles was 1.7% and 4.3%, respectively. Associations of breast cancer risk with tertiles of mammographic dense area were less strong than for percentage density. Conclusions: Endogenous sex hormone levels and mammographic density are independent risk factors for postmenopausal breast cancer, which in combination can identify women who might benefit from increased frequency of screening and chemoprophylaxis. PMID:24518596

  3. Energy dependence and systematics of level-density parameters in nuclei of mass number in the range of A = 20-60

    NASA Astrophysics Data System (ADS)

    Grudzevich, O. T.

    2015-12-01

    Existing direct and indirect experimental data on level densities in excited nuclei of mass and charge number in the ranges of A = 20-60 and Z = 11-27, respectively, were compiled and analyzed. Contradictions between values extracted from the results of measurements performed by different methods were revealed. Consistent input data were selected, and a systematics of level-density parameters was created on this basis within the generalized model of superfluid nuclei. The effect of the first discrete vibrational levels on extracted parameters was studied.

  4. Energy dependence and systematics of level-density parameters in nuclei of mass number in the range of A = 20–60

    SciTech Connect

    Grudzevich, O. T.

    2015-12-15

    Existing direct and indirect experimental data on level densities in excited nuclei of mass and charge number in the ranges of A = 20–60 and Z = 11–27, respectively, were compiled and analyzed. Contradictions between values extracted from the results of measurements performed by different methods were revealed. Consistent input data were selected, and a systematics of level-density parameters was created on this basis within the generalized model of superfluid nuclei. The effect of the first discrete vibrational levels on extracted parameters was studied.

  5. Three Gorges Dam: Impact of Water Level Changes on the Density of Schistosome-Transmitting Snail Oncomelania hupensis in Dongting Lake Area, China

    PubMed Central

    Wu, Jin-Yi; Zhou, Yi-Biao; Chen, Yue; Liang, Song; Li, Lin-Han; Zheng, Sheng-Bang; Zhu, Shao-ping; Ren, Guang-Hui; Song, Xiu-Xia; Jiang, Qing-Wu

    2015-01-01

    Background Schistosomiasis remains an important public health issue in China and worldwide. Oncomelania hupensis is the unique intermediate host of schistosoma japonicum, and its change influences the distribution of S. japonica. The Three Gorges Dam (TGD) has substantially changed the ecology and environment in the Dongting Lake region. This study investigated the impact of water level and elevation on the survival and habitat of the snails. Methods Data were collected for 16 bottomlands around 4 hydrological stations, which included water, density of living snails (form the Anxiang Station for Schistosomiasis Control) and elevation (from Google Earth). Based on the elevation, sixteen bottomlands were divided into 3 groups. ARIMA models were built to predict the density of living snails in different elevation areas. Results Before closure of TGD, 7 out of 9 years had a water level beyond the warning level at least once at Anxiang hydrological station, compared with only 3 out of 10 years after closure of TGD. There were two severe droughts that happened in 2006 and 2011, with much fewer number of flooding per year compared with other study years. Overall, there was a correlation between water level changing and density of living snails variation in all the elevations areas. The density of living snails in all elevations areas was decreasing after the TGD was built. The relationship between number of flooding per year and the density of living snails was more pronounced in the medium and high elevation areas; the density of living snails kept decreasing from 2003 to 2014. In low elevation area however, the density of living snails decreased after 2003 first and turned to increase after 2011. Our ARIMA prediction models indicated that the snails would not disappear in the Dongting Lake region in the next 7 years. In the low elevation area, the density of living snails would increase slightly, and then stabilize after the year 2017. In the medium elevation region

  6. High Levels of Serum DPP-4 Activity Are Associated with Low Bone Mineral Density in Obese Postmenopausal Women

    PubMed Central

    2016-01-01

    Background Dipeptidyl peptidase 4/CD26 (DPP-4) is a widely expressed cell surface serine protease. DPP-4 inhibitors, one of common anti-diabetic agents play a protective role in bone metabolism in recent studies. A soluble form of DPP-4 is found in serum, and exhibits DPP-4 enzymatic activity. However, the physiological role of serum or soluble DPP-4 and its relationship with DPP-4 enzymatic function remain poorly understood. The aims of current study were to determine the association between serum DPP-4 activity and bone mineral density (BMD) in postmenopausal women. Methods We recruited data and serum samples from 124 consecutive healthy postmenopausal women aged >50 years. We divided study subjects into obese (body mass index [BMI] ≥25 kg/m2) and non-obese (BMI <25 kg/m2) postmenopausal women and examined the correlation between serum DPP-4 activity and clinical variables in each groups. Results A total of 124 postmenopausal women was enrolled, with a mean age of 59.9±7.1 years. The mean BMI of the study patients was 24.4±2.8 kg/m2. Regarding bone turnover markers, serum DPP-4 activity was positively correlated with serum calcium concentrations, intact parathyroid hormone, and serum C-telopeptide levels in all of the study subjects. However, there was no association between serum DPP-4 activity and BMD in the spine or femoral neck in all of the study subjects. Serum DPP-4 activity was negatively correlated (R=−0.288, P=0.038) with BMD of the spine in obese postmenopausal women. Conclusion This study demonstrated for the first time that serum soluble DPP-4 activity was negatively correlated with BMD in obese postmenopausal women. PMID:26676330

  7. Quantitative Evaluation of the Impact of Bather Density on Levels of Human-Virulent Microsporidian Spores in Recreational Water▿

    PubMed Central

    Graczyk, Thaddeus K.; Sunderland, Deirdre; Tamang, Leena; Shields, Timothy M.; Lucy, Frances E.; Breysse, Patrick N.

    2007-01-01

    Microsporidial gastroenteritis, a serious disease of immunocompromised people, can have a waterborne etiology. During summer months, samples of recreational bathing waters were tested weekly for human-virulent microsporidian spores and water quality parameters in association with high and low bather numbers during weekends and weekdays, respectively. Enterocytozoon bieneusi spores were detected in 59% of weekend (n = 27) and 30% of weekday (n = 33) samples, and Encephalitozoon intestinalis spores were concomitant in a single weekend sample; the overall prevalence was 43%. The numbers of bathers, water turbidity levels, prevalences of spore-positive samples, and concentrations of spores were significantly higher for weekend than for weekday samples; P values were <0.001, <0.04, <0.03, and <0.04, respectively. Water turbidity and the concentration of waterborne spores were significantly correlated with bather density, with P values of <0.001 and <0.01, respectively. As all water samples were collected on days deemed acceptable for bathing by fecal bacterial standards, this study reinforces the scientific doubt about the reliability of bacterial indicators in predicting human waterborne pathogens. The study provides evidence that bathing in public waters can result in exposure to potentially viable microsporidian spores and that body contact recreation in potable water can play a role in the epidemiology of microsporidiosis. The study indicates that resuspension of bottom sediments by bathers resulted in elevated turbidity values and implies that the microbial load from both sediments and bathers can act as nonpoint sources for the contamination of recreational waters with Enterocytozoon bieneusi spores. Both these mechanisms can be considered for implementation in predictive models for contamination with microsporidian spores. PMID:17483272

  8. Effect of controlled low levels of SO/sub 2/ on grasshopper densities on a northern mixed-grass prairie

    SciTech Connect

    McNary, T.J.; Milchunas, D.G.; Leetham, J.W.; Lauenroth, W.K.; Dodd, J.L.

    1981-02-01

    A northern mixed-grass prairie was exposed to monthly median SO/sub 2/ concentrations of 73, 134, and 228 ..mu..g/m/sup 3/. Total grasshopper density and the density of Melanoplus sanguinipes (F.) were significantly (P < 0.01) reduced by SO/sub 2/ treatment on late-growing-season dates within each year of SO/sub 2/ exposure. Grasshopper density tended to decrease with increasing SO/sub 2/ concentration. Sulfur dioxide did not alter the relative proportions of M. sanguinipes in the total population. 14 references, 1 figure.

  9. Measurements of copper ground-state and metastable level population densities in a copper-chloride laser

    NASA Technical Reports Server (NTRS)

    Nerheim, N. M.

    1977-01-01

    The population densities of both the ground and the 2D(5/2) metastable states of copper atoms in a double-pulsed copper-chloride laser are correlated with laser energy as a function of time after the dissociation current pulse. Time-resolved density variations of the ground and excited copper atoms were derived from measurements of optical absorption at 324.7 and 510.6 nm, respectively, over a wide range of operating conditions in laser tubes with diameters of 4 to 40 mm. The minimum delay between the two current pulses at which lasing was observed is shown to be a function of the initial density and subsequent decay of the metastable state. Similarly, the maximum delay is shown to be a function of the initial density and decay of the ground state.

  10. Method for making a low density polyethylene waste form for safe disposal of low level radioactive material

    DOEpatents

    Colombo, P.; Kalb, P.D.

    1984-06-05

    In the method of the invention low density polyethylene pellets are mixed in a predetermined ratio with radioactive particulate material, then the mixture is fed through a screw-type extruder that melts the low density polyethylene under a predetermined pressure and temperature to form a homogeneous matrix that is extruded and separated into solid monolithic waste forms. The solid waste forms are adapted to be safely handled, stored for a short time, and safely disposed of in approved depositories.

  11. Anomalous density dependence of the activation gap of ν = 5/2 fractional quantum Hall state at extremely large Landau level mixing

    NASA Astrophysics Data System (ADS)

    Samkharadze, Nodar; Manfra, Michael; Pfeiffer, Loren; West, Ken; Csathy, Gabor

    2013-03-01

    We have conducted a study of the density dependence of ν = 5/2 fractional quantum Hall state (FQHS) in the regime of extremely low densities, down to n =4.9x10⌃10 cm⌃-2. In the density range accessed in our sample, the Landau level mixing parameter κ spans the so far unexplored range 2.52< κ<2.82. Here we observe an anomalous dependence of the activation gap of ν = 5/2 FQHS on the carrier density. We discuss the possible origins of this unexpected behavior. N.S. and G.C. were supported by the NSF grant DMR-0907172 and DMR-1207375. K. West and L. Pfeiffer acknowledge the support of the Princeton NSF-MRSEC and the Moore Foundation.

  12. Analysis of charge density and Fermi level of AlInSb/InSb single-gate high electron mobility transistor

    NASA Astrophysics Data System (ADS)

    Chandra, S. Theodore; Balamurugan, N. B.; Bhuvaneswari, M.; Anbuselvan, N.; Mohankumar, N.

    2015-06-01

    A compact model is proposed to derive the charge density of the AlInSb/InSb HEMT devices by considering the variation of Fermi level, the first subband, the second subband and sheet carrier charge density with applied gate voltage. The proposed model considers the Fermi level dependence of charge density and vice versa. The analytical results generated by the proposed model are compared and they agree well with the experimental results. The developed model can be used to implement a physics based compact model for an InSb HEMT device in SPICE applications. Project supported by the Council of Scientific & Industrial Research (CSIR), India under the Senior Research Fellowship Scheme (No. 08/237(0005)/2012-EMR-I).

  13. ( γ, 2n)-Reaction cross-section calculations of several even-even lanthanide nuclei using different level density models

    NASA Astrophysics Data System (ADS)

    Kaplan, A.; Sarpün, İ. H.; Aydın, A.; Tel, E.; Çapalı, V.; Özdoǧan, H.

    2015-01-01

    There are several level density models that can be used to predict photo-neutron cross sections. Some of them are Constant Temperature + Fermi Gas Model (CTFGM), Back-Shifted Fermi Gas Model (BSFM), Generalized Superfluid Model (GSM), Hartree-Fock-Bogoliubov microscopic Model (HFBM). In this study, the theoretical photo-neutron cross sections produced by ( γ, 2 n) reactions for several eveneven lanthanide nuclei such as 140,142Ce, 142,144,146,148,150Nd, 144,148,150,152,154Sm, and 160Gd have been calculated on the different level density models as mentioned above by using TALYS 1.6 and EMPIRE 3.1 computer codes for incident photon energies up to 30 MeV. The obtained results have been compared with each other and available experimental data existing in the EXFOR database. Generally, at least one level density model cross-section calculations are in agreement with the experimental results for all reactions except 144Sm( γ, 2 n)142Sm along the incident photon energy, TALYS 1.6 BSFM option for the level density model cross-section calculations can be chosen if the experimental data are not available or are improbable to be produced due to the experimental difficulty.

  14. (γ, 2n)-Reaction cross-section calculations of several even-even lanthanide nuclei using different level density models

    SciTech Connect

    Kaplan, A.; Sarpün, İ. H.; Aydın, A.; Tel, E.; Çapalı, V.; Özdoǧan, H.

    2015-01-15

    There are several level density models that can be used to predict photo-neutron cross sections. Some of them are Constant Temperature + Fermi Gas Model (CTFGM), Back-Shifted Fermi Gas Model (BSFM), Generalized Superfluid Model (GSM), Hartree-Fock-Bogoliubov microscopic Model (HFBM). In this study, the theoretical photo-neutron cross sections produced by (γ, 2n) reactions for several eveneven lanthanide nuclei such as {sup 140,142}Ce, {sup 142,144,146,148,150}Nd, {sup 144,148,150,152,154}Sm, and {sup 160}Gd have been calculated on the different level density models as mentioned above by using TALYS 1.6 and EMPIRE 3.1 computer codes for incident photon energies up to 30 MeV. The obtained results have been compared with each other and available experimental data existing in the EXFOR database. Generally, at least one level density model cross-section calculations are in agreement with the experimental results for all reactions except {sup 144}Sm(γ, 2n){sup 142}Sm along the incident photon energy, TALYS 1.6 BSFM option for the level density model cross-section calculations can be chosen if the experimental data are not available or are improbable to be produced due to the experimental difficulty.

  15. Classroom-Level Predictors of the Social Status of Aggression: Friendship Centralization, Friendship Density, Teacher-Student Attunement, and Gender

    ERIC Educational Resources Information Center

    Ahn, Hai-Jeong; Rodkin, Philip C.

    2014-01-01

    This study investigated moderating effects of classroom friendship network structures (centralization and density), teacher-student attunement on aggression and popularity, and gender on changes in the social status of aggression over 1 school year. Longitudinal multilevel analyses with 2 time points (fall and spring) were conducted on a sample of…

  16. Variation in Lesion Characteristics, Densities and Sporulation Levels Among Soybean Germplasm Accessions Resistant to Soybean Rust (Phakopsora Pachyrhizi)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of reddish-brown (RB) lesions instead of tan lesions on soybean leaves infected by the soybean rust (SBR) fungus, Phakopsora pachyrhizi, is generally considered to indicate at least partial resistance. Lower disease severity and/or lesion density relative to susceptible hosts with a ...

  17. Administration of hydrogen-saturated saline decreases plasma low-density lipoprotein cholesterol levels and improves high-density lipoprotein function in high-fat diet-fed hamsters.

    PubMed

    Zong, Chuanlong; Song, Guohua; Yao, Shutong; Li, Luqin; Yu, Yang; Feng, Lei; Guo, Shoudong; Luo, Tian; Qin, Shucun

    2012-06-01

    Hydrogen (dihydrogen; H(2)) has an antiatherosclerotic effect in apolipoprotein (apo) E knockout mice. The goals of this study were to further characterize the effects of H(2) on the content, composition, and biological activities of plasma lipoproteins in golden hamsters. Plasma analysis by enzymatic method and fast protein liquid chromatography showed that 4-week intraperitoneal injection of hydrogen-saturated saline remarkably decreased plasma total cholesterol and low-density lipoprotein (LDL) cholesterol levels in high-fat diet-fed hamsters. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of apolipoproteins from ultracentrifugally isolated plasma lipoproteins revealed a marked decrease of apo B100 and apo B48 in LDL. A profound decrease of apo E level in very low-density lipoprotein was also observed. Besides, we determined the functional quality of high-density lipoprotein (HDL) particles isolated from H(2)-treated and control mice. H(2) significantly improved HDL functionality assessed in 2 independent ways, namely, (1) stimulation of cholesterol efflux from macrophage foam cells by measuring HDL-induced [(3)H]cholesterol efflux and (2) protection against LDL oxidation as a measure of Cu(2+)-induced thiobarbituric acid reactive substances formation. Administration of hydrogen-saturated saline decreases plasma LDL cholesterol and apo B levels and improves hyperlipidemia-injured HDL functions, including the capacity of enhancing cellular cholesterol efflux and playing antioxidative properties, in high-fat diet-fed hamsters. PMID:22153840

  18. Habitat-related birdsong divergence: a multi-level study on the influence of territory density and ambient noise in European blackbirds.

    PubMed

    Ripmeester, Erwin A P; Kok, Jet S; van Rijssel, Jacco C; Slabbekoorn, Hans

    2010-01-01

    Song plays an important role in avian communication and acoustic variation is important at both the individual and population level. Habitat-related variation between populations in particular can reflect adaptations to the environment accumulated over generations, but this may not always be the case. In this study, we test whether variation between individuals matches local conditions with respect to noise level and territory density to examine whether short-term flexibility could contribute to song divergence at the population level. We conducted a case study on an urban and forest population of the European blackbird and show divergence at the population level (i.e. across habitats) in blackbird song, anthropogenic noise level and territory density. Unlike in several other species, we found a lack of any correlation at the individual level (i.e. across individuals) between song features and ambient noise. This suggests species-specific causal explanations for noise-dependent song differentiation which are likely associated with variation in song-copying behaviour or feedback constraints related to variable singing styles. On the other hand, we found that at the level of individual territories, temporal features, but not spectral ones, are correlated to territory density and seasonality. This suggests that short-term individual variation can indeed contribute to habitat-dependent divergence at the population level. As this may undermine the potential role for song as a population marker, we conclude that more investigations on individual song flexibility are required for a better understanding of the impact of population-level song divergence on hybridisation and speciation. PMID:20119488

  19. Combined effects between temporal heterogeneity of water supply, nutrient level, and population density on biomass of four broadly distributed herbaceous species.

    PubMed

    Hagiwara, Yousuke; Kachi, Naoki; Suzuki, Jun-Ichirou

    2012-01-01

    Temporal heterogeneity of water supply affects grassland community productivity and it can interact with nutrient level and intraspecific competition. To understand community responses, the responses of individual species to water heterogeneity must be evaluated while considering the interactions of this heterogeneity with nutrient levels and population density. We compared responses of four herbaceous species grown in monocultures to various combinations of water heterogeneity, nutrient level, and population density: two grasses (Cynodon dactylon and Lolium perenne), a forb (Artemisia princeps), and a legume (Trifolium repens). Treatment effects on shoot and root biomass were analyzed. In all four species, shoot biomass was larger under homogeneous than under heterogeneous water supply. Shoot responses of L. perenne tended to be greater at high nutrient levels. Although root biomass was also larger under homogeneous water supply, effects of water heterogeneity on root biomass were not significant in the grasses. Trifolium repens showed marked root responses, particularly at high population density. Although greater shoot and root growth under homogeneous water supply appears to be a general trend among herbaceous species, our results suggested differences among species could be found in the degree of response to water heterogeneity and its interactions with nutrient level and intraspecific competition. PMID:21327692

  20. To study of different level of nitrogen manure and density on yield and yield component of variety of K.S.C 704 in dry region of sistan

    SciTech Connect

    Dahmardeh, M.; Forghani, F.; Khammari, E.

    2008-01-30

    Out of three grain of the world, Corn is one of the best, About 7 to 10 thousand years ago in south of Mexico corn become domesticated. In the year 1995 culfivation of corn in the world was 130 mil/ha, and to Total production of the world of corn is 507 M/Tons. Average yield of corn in the year 1995 Among Producer countries was 7.78 To 7.60 t/ha in fance and united state was state was 2.36 To 2.20 t/ha, but in Brazil and Mexico Production of corn was different. With this regards, special manner has been arranged for the suitable cultivation or suitable density plants in one heactar on cultivation variety of K.S.C 704 corn. Also suitable level of Nitrogen manure, this Protect in climatic condition of Sistan region done, sith complete block design with 3 replication. Experiment has been selected as split plot, the main plot with 4 different concentration level such as (200-250-3500 and 350 Kg/ha) and sub plot density with 3 different level such as 111000,83000 and 66000 plan/ha respectively. From stage growth up to harvesting of corn in this reache having Data for each treat. ment, After harvesting Analysis of variance and companion of Average of each treatment has been done by DunKan method. Results has been shown, Measurment of characteristics (yield component) seed yield effected different density level of manure, with increasing of manure weight of one thousand seed yield and also in high density showed high significant differente amoung each other. These are with suitable climatic condition of sistan region if enough water will be available ed using Amount of 350 ks/ha Nitrogen manure and with density 111000 plants/ha we can product suitable seed yield Biological yield.

  1. To study of different level of nitrogen manure and density on yield and yield component of variety of K.S.C 704 in dry region of sistan

    NASA Astrophysics Data System (ADS)

    Dahmardeh, M.; Forghani, F.; Khammari, E.

    2008-01-01

    Out of three grain of the world, Corn is one of the best, About 7 to 10 thousand years ago in south of Mexico corn become domesticated. In the year 1995 culfivation of corn in the world was 130 mil/ha, and to Total production of the world of corn is 507 M/Tons. Average yield of corn in the year 1995 Among Producer countries was 7.78 To 7.60 t/ha in fance and united state was state was 2.36 To 2.20 t/ha, but in Brazil and Mexico Production of corn was different. With this regards, special manner has been arranged for the suitable cultivation or suitable density plants in one heactar on cultivation variety of K.S.C 704 corn. Also suitable level of Nitrogen manure, this Protect in climatic condition of Sistan region done, sith complete block design with 3 replication. Experiment has been selected as split plot, the main plot with 4 different concentration level such as (200-250-3500 and 350 Kg/ha) and sub plot density with 3 different level such as 111000,83000 and 66000 plan/ha respectively. From stage growth up to harvesting of corn in this reache having Data for each treat. ment, After harvesting Analysis of variance and companion of Average of each treatment has been done by DunKan method. Results has been shown, Measurment of characteristics (yield component) seed yield effected different density level of manure, with increasing of manure weight of one thousand seed yield and also in high density showed high significant differente amoung each other. These are with suitable climatic condition of sistan region if enough water will be available ed using Amount of 350 ks/ha Nitrogen manure and with density 111000 plants/ha we can product suitable seed yield Biological yield.

  2. Measurements of cross sections for electron-impact excitation into the metastable levels of argon and number densities of metastable argon atoms

    SciTech Connect

    Schappe, R.S.; Schulman, M.B.; Anderson, L.W.; Lin, C.C. )

    1994-07-01

    The technique of laser-induced fluorescence (LIF) has been applied to measure the cross sections for electron-impact excitation into the metastable levels of argon atoms as well as the number densities of the argon metastable atoms produced by electron excitation. A monoenergetic electron beam excites the ground-state atoms into the 3[ital p][sup 5]4[ital s] [sup 3][ital P][sub 0],[sup 3][ital P][sub 2] metastable levels (1[ital s][sub 3] and 1[ital s][sub 5] in Paschen's notation) and a pulsed laser pumps the atoms of a metastable level to a level in the 3[ital p][sup 5]4[ital p] configuration (2[ital p] in Paschen's notation). The transient LIF from the 2[ital p] level is shown to be proportional to the apparent cross section of the metastable level and to the metastable number densities so that measurements of LIF enable us to determine both metastable cross sections and number densities. Methods for absolute calibration are described. We obtain both the apparent and direct excitation cross sections for each of the two metastable levels for electron energies from threshold to 200 eV and the results are compared with previous experimental and theoretical works. The pulsed LIF technique is also used to determine the disappearance rates of the metastable atoms after the electron beam is turned off. Two distinct decay modes are found and the observed behaviors are consistent with calculations based on diffusion theory.

  3. The effect of physical water quality and water level changes on the occurrence and density of Anopheles mosquito larvae around the shoreline of the Koka reservoir, central Ethiopia

    NASA Astrophysics Data System (ADS)

    Teklu, B. M.; Tekie, H.; McCartney, M.; Kibret, S.

    2010-12-01

    Entomological studies to determine the effect of the physical characteristics of mosquito larval breeding water bodies and reservoir water level changes on the occurrence of Anopheles mosquito larvae were conducted in two villages at Koka reservoir in central Ethiopia between August and December 2007. Of the two study villages, Ejersa is located close to the reservoir, and Kuma is 5 km away from it. Data on the type, number and physical characteristics of Anopheles larval breeding habitat, species composition and densities of anopheles mosquitoes in and around the study villages were investigated and recorded. Meteorological and reservoir water level data were compared with availability of Anopheles larval breeding sites and densities. Entomological data, derived from weekly larval collections, showed that Anopheles pharoensis Theobald, Anopheles gambiae s.l. Giles, Anopheles coustani Laveran and Anopheles squamosus Theobald were breeding in the study area. The mean larval density of An. gambiae s.l. in this study was higher in slightly turbid and shallow aquatic habitat than in turbid and relatively deep aquatic habitat. The density of An. pharoensis in habitat with floating vegetation and with relatively shady conditions was significantly higher than that of less shaded aquatic habitat and greater emergent vegetation. There was also a positive correlation between the occurrence of Anopheles larvae with the water and daily minimum atmospheric temperature. Similarly at Ejersa, over the sampling period, there was a positive correlation between falling reservoir water levels and the number of positive breeding habitats. These results confirm that physical characteristics of the water bodies play an important role in the species composition, total Anopheles larval count, and the density of Anopheles mosquitoes. Suitable breeding habitat in the vicinity of the reservoir village was strongly associated with the reservoir. This is particularly important for An

  4. Postsynaptic density levels of the NMDA receptor NR1 subunit and PSD-95 protein in prefrontal cortex from people with schizophrenia

    PubMed Central

    Catts, Vibeke Sørensen; Derminio, Dominique Suzanne; Hahn, Chang-Gyu; Weickert, Cynthia Shannon

    2015-01-01

    Background: There is converging evidence of involvement of N-methyl-d-aspartate (NMDA) receptor hypofunction in the pathophysiology of schizophrenia. Our group recently identified a decrease in total NR1 mRNA and protein expression in the dorsolateral prefrontal cortex in a case-control study of individuals with schizophrenia (n=37/group). The NR1 subunit is critical to NMDA receptor function at the postsynaptic density, a cellular structure rich in the scaffolding protein, PSD-95. The extent to which the NMDA receptor NR1 subunit is altered at the site of action, in the postsynaptic density, is not clear. Aims: To extend our previous results by measuring levels of NR1 and PSD-95 protein in postsynaptic density-enriched fractions of prefrontal cortex from the same individuals in the case-control study noted above. Methods: Postsynaptic density-enriched fractions were isolated from fresh-frozen prefrontal cortex (BA10) and subjected to western blot analysis for NR1 and PSD-95. Results: We found a 20% decrease in NR1 protein (t(66)=−2.874, P=0.006) and a 30% decrease in PSD-95 protein (t(63)=−2.668, P=0.010) in postsynaptic density-enriched fractions from individuals with schizophrenia relative to unaffected controls. Conclusions: Individuals with schizophrenia have less NR1 protein, and therefore potentially fewer functional NMDA receptors, at the postsynaptic density. The associated decrease in PSD-95 protein at the postsynaptic density suggests that not only are glutamate receptors compromised in individuals with schizophrenia, but the overall spine architecture and downstream signaling supported by PSD-95 may also be deficient. PMID:27336043

  5. Correlation of white female breast cancer incidence trends with nitrogen dioxide emission levels and motor vehicle density patterns.

    PubMed

    Chen, Fan; Bina, William F

    2012-02-01

    The long-term trend of female breast cancer incidence rates in the United States and some European countries demonstrates a similar pattern: an increasing trend in the last century followed by a declining trend in this century. The well-known risk factors cannot explain this trend. We compared the breast cancer incidence trends obtained from SEER data with the trend of nitrogen dioxides (NOx) emission and monitoring data as well as motor vehicle density data. The upward followed by downward trend of NOx is similar to the breast cancer incidence trend but with an offset of 20 years earlier. Motor vehicles are the major source of NOx emissions. The geographic distribution of motor vehicles density in 1970 in the observed US counties is positively correlated with breast cancer incidence rates (R(2) 0.8418, the correlation coefficient = 0.9175) in 1980-1995. Because both the time trend and geographic pattern are associated with breast cancer incidence rates, further studies on the relationship between breast cancer and air pollution are needed. PMID:22076479

  6. Ammonia Levels and Urine-Spot Characteristics as Cage-Change Indicators for High-Density Individually Ventilated Mouse Cages.

    PubMed

    Washington, Ida M; Payton, Mark E

    2016-01-01

    Mouse cage and bedding changes are potentially stressful to mice and are also labor- and resource-intensive. These changes are often performed on a calendar-based schedule to maintain a clean microenvironment and limit the concentrations of ammonia to which mice and workers are exposed. The current study sought to establish a performance-based approach to mouse cage-changing that uses urine spot characteristics as visual indicators of intracage ammonia levels. Colorimetric ammonia indicators were used to measure ammonia levels in individually-ventilated cages (IVC) housing male or female mice (n =5 per cage) of various strains at 1 to 16 d after cage change. Urine spot characteristics were correlated with ammonia levels to create a visual indicator of the cage-change criterion of 25 ppm ammonia. Results demonstrated a consistent increase in ammonia levels with days since cage change, with cages reaching the cage-change criterion at approximately 10 d for IVC containing male mice and 16 d for those with female mice. Ammonia levels were higher for male than female mice but were not correlated with mouse age. However, urine spot diameter, color, and edge characteristics were strongly correlated with ammonia levels. Husbandry practices based on using urine spot characteristics as indicators of ammonia levels led to fewer weekly cage changes and concomitant savings in labor and resources. Therefore, urine spot characteristics can be used as visual indicators of intracage ammonia levels for use of a performance (urine spot)-based approach to cage-changing frequency that maintains animal health and wellbeing. PMID:27177558

  7. Nuclear level densities of 64,66 Zn from neutron evaporation

    SciTech Connect

    Ramirez, A. P. D.; Voinov, A. V.; Grimes, S. M.; Schiller, A.; Brune, C. R.; Massey, T. N.; Salas-Bacci, A.

    2013-12-26

    Double differential cross sections of neutrons from d+63,65Cu reactions have been measured at deuteron energies of 6 and 7.5 MeV. The cross sections measured at backward angles have been compared to theoretical calculations in the framework of the statistical Hauser-Feshbach model. Three different level density models were tested: the Fermi-gas model, the Gilbert-Cameron model, and the microscopic approach through the Hartree-Fock-Bogoliubov method (HFBM). The calculations using the Gilbert-Cameron model are in best agreement with our experimental data. Level densities of the residual nuclei 64Zn and 66Zn have been obtained from statistical neutron evaporation spectra. In conclusion, the angle-integrated cross sections have been analyzed with the exciton model of nuclear reaction.

  8. The structure of human high density lipoprotein and the levels of apolipoprotein A-I in plasma as determined by radioimmunoassay.

    PubMed

    Schonfeld, G; Pfleger, B

    1974-08-01

    The major apoprotein of high density lipoprotein is apolipoprotein A-I (ApoA-I). In addition to being a structural component of this class of lipoproteins, ApoA-I also has a physiologic role as an activator of lecithin-cholesterol acyl transferase, an enzyme important in the metabolism of all lipoproteins. To measure ApoA-I content in human plasma, to assess its immunologic activity in hyperlipoproteinemia, and to carry out certain structural studies of high density lipoproteins, we have developed a double antibody radioimmunoassay. ApoA-I, isolated by gel filtration, was used to produce monospecific antisera. ApoA-I was iodinated by chloramine-T and the resulting [(125)I]-ApoA-I was purified by gel filtration. > 85% of [(125)I]-ApoA-I was precipitated by antibody, and 90% of bound [(125)I]ApoA-I was displaced by "cold" ApoA-I. Other lipoproteins and apoproteins did not react. Plasma and high density lipoprotein from normals and subjects with hyperlipoproteinemia displaced counts in parallel with ApoA-I, suggesting that the same antigenic determinants were reacting with antibody on lipid-free and lipid-associated ApoA-I. However, less than 5% of ApoA-I of high density lipoprotein reacted in the assay. Removal of the lipid by extraction increased the reactivity of ApoA-I in high density lipoprotein 15-20-fold; thus more than 95% of the ApoA-I molecules in "intact" high density lipoprotein are unreactive with antibody. Normal and hyperlipoproteinemic plasma and high density lipoproteins isolated from the same subjects continued to display parallelism with ApoA-I standard after lipid extraction, suggesting that ApoA-I of normal and hyperliproteinemic subjects are immunologically identical. About 90% of ApoA-I was in the d 1.063-1.21 fractions of normal plasma, trace quantities were found in the lipoproteins of d < 1.063, and the rest (about 10%) was in the d > 1.21 fraction. Normal plasma levels, assessed in extracted plasmas with a precision of 8%, were 100+/-35 mg

  9. Multi-Dimensional Quantum Effect Simulation Using a Density-Gradient Model and Script-Level Programming Techniques

    NASA Technical Reports Server (NTRS)

    Rafferty, Connor S.; Biegel, Bryan A.; Yu, Zhi-Ping; Ancona, Mario G.; Bude, J.; Dutton, Robert W.; Saini, Subhash (Technical Monitor)

    1998-01-01

    A density-gradient (DG) model is used to calculate quantum-mechanical corrections to classical carrier transport in MOS (Metal Oxide Semiconductor) inversion/accumulation layers. The model is compared to measured data and to a fully self-consistent coupled Schrodinger and Poisson equation (SCSP) solver. Good agreement is demonstrated for MOS capacitors with gate oxide as thin as 21 A. It is then applied to study carrier distribution in ultra short MOSFETs (Metal Oxide Semiconductor Field Effect Transistor) with surface roughness. This work represents the first implementation of the DG formulation on multidimensional unstructured meshes. It was enabled by a powerful scripting approach which provides an easy-to-use and flexible framework for solving the fourth-order PDEs (Partial Differential Equation) of the DG model.

  10. Effect of a magnetic flux line on the quantum beats in the Henon-Heiles level density.

    PubMed

    Brack, M.; Bhaduri, R. K.; Law, J.; Maier, Ch.; Murthy, M. V. N.

    1995-03-01

    The quantum density of states of the Henon-Heiles potential displays a pronounced beating pattern. This has been explained by the interference of three isolated classical periodic orbits with nearby actions and periods. A singular magnetic flux line, passing through the origin, drastically alters the beats even though the classical Lagrangian equations of motion remain unchanged. Some of the changes can be easily understood in terms of the Aharonov-Bohm effect. However, we find that the standard periodic orbit theory does not reproduce the diffraction-like quantum effects on those classical orbits which intersect the singular flux line, and argue that corrections of relative order variant Planck's over 2pi are necessary to describe these effects. We also discuss the changes in the distribution of nearest-neighbor spacings in the eigenvalue spectrum, brought about by the flux line. (c) 1995 American Institute of Physics. PMID:12780185

  11. Developing Street-Level PM2.5 and PM10 Land Use Regression Models in High-Density Hong Kong with Urban Morphological Factors.

    PubMed

    Shi, Yuan; Lau, Kevin Ka-Lun; Ng, Edward

    2016-08-01

    Monitoring street-level particulates is essential to air quality management but challenging in high-density Hong Kong due to limitations in local monitoring network and the complexities of street environment. By employing vehicle-based mobile measurements, land use regression (LUR) models were developed to estimate the spatial variation of PM2.5 and PM10 in the downtown area of Hong Kong. Sampling runs were conducted along routes measuring a total of 30 km during a selected measurement period of total 14 days. In total, 321 independent variables were examined to develop LUR models by using stepwise regression with PM2.5 and PM10 as dependent variables. Approximately, 10% increases in the model adjusted R(2) were achieved by integrating urban/building morphology as independent variables into the LUR models. Resultant LUR models show that the most decisive factors on street-level air quality in Hong Kong are frontal area index, an urban/building morphological parameter, and road network line density and traffic volume, two parameters of road traffic. The adjusted R(2) of the final LUR models of PM2.5 and PM10 are 0.633 and 0.707, respectively. These results indicate that urban morphology is more decisive to the street-level air quality in high-density cities than other cities. Air pollution hotspots were also identified based on the LUR mapping. PMID:27381187

  12. ApoL1 levels in high density lipoprotein and cardiovascular event presentation in patients with familial hypercholesterolemia.

    PubMed

    Cubedo, Judit; Padró, Teresa; Alonso, Rodrigo; Mata, Pedro; Badimon, Lina

    2016-06-01

    HDL composition rather than HDL-cholesterol (HDL-C) levels seems to be a key determinant of HDL-induced atheroprotection. Heterozygous familial hypercholesterolemia (FH) patients, with lifelong exposure to high LDL levels, show a high prevalence of premature coronary artery disease. We hypothesized that HDL of FH patients might have a modified protein composition and investigated the proteomic signature of HDL obtained from FH patients and their unaffected relatives. HDLs were characterized by 2D electrophoresis/MS in 10 families from the SAFEHEART cohort (3 individuals/family: 2 with genetic FH diagnosis and 1 non-FH relative) clinically characterized and treated as per guidelines. FH patients had lower apoA-I levels and a differential HDL distribution profile of apoL1 and apoA-IV. ELISA validation revealed decreased apoL1 serum levels in FH patients. ApoL1 levels were able to predict presentation of an ischemic cardiac event, and apoL1/HDL-C ratio was associated with the survival rate after the event. FH patients who died because of a fatal cardiac event had lower apoL1 and LCAT content in HDL3 an average of 3.5 years before the event than those who survived. Changes in HDL protein composition could affect patients' prognosis. The proteomic profile of apoL1 is modified in HDLs of high cardiovascular risk patients, and apoL1 plasma levels are significantly lower in serum and in HDL3 of patients that will suffer an adverse cardiac event within 3 years. PMID:27112635

  13. Gas pressure and electron density at the level of the active zone of hollow cathode arc discharges

    NASA Technical Reports Server (NTRS)

    Minoo, M. H.

    1984-01-01

    A model for the longitudinal variations of the partial pressures of electrons, ions, and neutral particles is proposed as a result of an experimental study of pressure variations at the level of the active zone as a function of the various discharge parameters of a hollow cathode arc. The cathode region where the temperature passes through its maximum is called active zone. The proposed model embodies the very important variations which the partial electron and neutral particles pressures undergo at the level of the active zone.

  14. Density matrix solutions for the susceptibilities of a three-level system with arbitrary relaxation rates and field strengths

    NASA Technical Reports Server (NTRS)

    Ryan, J. C.; Lawandy, N. M.

    1986-01-01

    The susceptibilities for a three-level system with arbitrary pump and signal field strengths are derived for arbitrary longitudinal and transverse relaxation rates. The results are of interest in connection with the calculation of the Raman gain in systems where resonance enhancement plays a dominant role.

  15. [Effect of calcitonin on regional blood flow in bones, serum levels of IGF-I and osteocalcin, density and weight of bone ash in oophorectomized rats].

    PubMed

    Zák, J; Kapitola, J; Wallischová, J

    2003-01-01

    It is known that in cases of increased bone remodelation rate, i.e. after castration, local bone blood flow is also increased. But in case of adequate hormonal substitution, bone blood flow, similarly as the remodelation rate, return to normal ranges. Until now, there is no knowledge, if other drug can influence enhanced bone blood flow in oophorectomized animals. In this study authors treated oophorectomized female rats with calcitonin and followed bone blood flow, together with biochemical parameters of bone remodelation activity (osteocalcine), IGF-I levels, weight of bone ash and bone density. The female rats were divided in four groups: controls, oophorectomized, with calcitonin and oophorectomized with calcitonin. The bone blood flow was determined by method of body dispersion of radioactive strontium labelled microspheres. The results of this study show, that, in comparison with controls, the bone remodelation rate (documented with increased osteocalcine levels) and radioactive strontium labelled microspheres capture in bone in increased after oophorectomy (p < 0.05). Ash weight and bone density were decreased (p < 0.05). Simultaneously, the blood IGF-I levels were increased (p < 0.05). After oophorectomized animals were treated with calcitonin, all parameters mentioned above headed towards normal ranges in comparison with group of oophorectomized female rats without calcitonin (p < 0.05). Changes of serum IGF-I levels follow changes of microspheres capture in each group of animals. Authors support the hypothesis, that blood levels of IGF-I could influence local bone blood flow. Calcitonin treatment of oophorectomized animals diminishes also decrement of ash weight and bone density. Results of this work show, that similarly as hormonal substitution therapy after oophorectomy, calcitonin also diminishes increased bone blood flow and bone remodelation parameters. The degree of bone blood flow is probably connected with activity of bone remodelling. PMID

  16. Genetic determination of high-density lipoprotein-cholesterol and apolipoprotein A-1 plasma levels in a family study of cardiac catheterization patients

    SciTech Connect

    Prenger, V.L.; Beaty, T.H.; Kwiterovich, P.O. )

    1992-11-01

    Plasma levels of two lipoprotein risk factors, high-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A-1 (apo A-1), have been shown to be negatively associated with the risk of developing coronary artery disease, and several reports have examined familial factors in HDL-C and apo A-1 levels. A number of studies suggest that shared genes influence familial resemblance of these lipoprotein levels far more than do shared environments. Possible mechanisms for the inheritance of these risk factors (HDL-C and apo A-1 plasma levels) are explored using data from 390 individuals in 69 families ascertained through probands undergoing diagnostic cardiac catheterization. Segregation analysis was used to test a series of specific models of inheritance. Evidence for single-locus control of apo A-1 levels, with Mendelian transmission of a dominant allele leading to elevated apo A-1 levels, was seen in these families, although there was additional correlation among sibs present. This locus accounted for 48.6% and 37.2% of the total variation in apo A-1 levels in males and females, respectively. Similar evidence of segregation at a single locus controlling HDL-C levels was not seen in these families. 27 refs., 3 figs., 5 tabs.

  17. Duration of Type 2 Diabetes and Very Low Density Lipoprotein Levels Are Associated with Cognitive Dysfunction in Metabolic Syndrome

    PubMed Central

    Yogi-Morren, Divya; Galioto, Rachel; Strandjord, Sarah Elizabeth; Kennedy, L.; Manroa, Pooja; Kirwan, John P.; Kashyap, Sangeeta; Gunstad, John

    2014-01-01

    Type 2 diabetes (T2D) is now recognized as an independent risk factor for accelerated cognitive decline and neurological conditions like Alzheimer's disease. Less is known about the neurocognitive function of T2D patients with comorbid metabolic syndrome, despite their elevated risk for impairment. Computerized testing in 47 adults with T2D that met criteria for NCEP metabolic syndrome revealed that cognitive impairment was prevalent, including 13% in tests of memory, 50% in attention, and 35% in executive function. Partial correlations showed that longer duration of diabetes was associated with poorer performance on tests of basic attention (r = −0.43), working memory (r = 0.43), and executive function (r = 0.42). Strong associations between very low density lipoprotein and poor cognitive function also emerged, including tests of set shifting (r = 0.47) and cognitive inhibition (r = −0.51). Findings suggest that patients with T2D that meet criteria for metabolic syndrome are at high risk for cognitive impairment. Prospective studies should look to replicate these findings and examine the possible neuroprotective effects of lipid-lowering medication in this population. PMID:25057411

  18. Polybrominated diphenyl ether (PBDE) levels in peregrine falcon (Falco peregrinus) eggs from California correlate with diet and human population density.

    PubMed

    Newsome, Seth D; Park, June-Soo; Henry, Bill W; Holden, Arthur; Fogel, Marilyn L; Linthicum, Janet; Chu, Vivian; Hooper, Kim

    2010-07-01

    Peregrine falcons are now considered a conservation success story due in part to the phasing out of harmful contaminants that adversely affected reproduction. Recent studies have shown that peregrine eggs collected from California cities, however, have high levels of the higher-brominated polybrominated diphenyl ethers (SigmaPBDE(183-209)), a class of industrial flame retardants, in comparison to published data for other wildlife. Sources of these high PBDE levels and unusual PBDE profiles are unknown. Here we analyzed the stable carbon (delta(13)C), hydrogen (deltaD), and nitrogen (delta(15)N) isotope composition of peregrine eggs collected from urban and nonurban habitats. We found that delta(13)C values were significantly higher in urban versus nonurban eggs, suggesting that urban peregrines indirectly receive anthropogenic subsidies via their consumption of prey reliant on corn-based anthropogenic foods. delta(15)N and deltaD values were significantly lower in urban versus nonurban eggs, reflecting differences in dietary diversity and food/water sources available to peregrines in each habitat. These patterns suggest a link between an anthropogenic diet and high levels of SigmaPBDE(183-209) in California peregrines, and identify anthropogenic food as a potentially important PBDE exposure pathway for urban wildlife. If diet is an important PBDE exposure pathway for peregrines, continued high body burdens of SigmaPBDE(183-209) may be a potential risk to ongoing peregrine conservation efforts in California. PMID:20540532

  19. Gardenia oil increases estradiol levels and bone material density by a mechanism associated with upregulation of COX-2 expression in an ovariectomized rat model

    PubMed Central

    LI, BAOLI; ZHANG, YONGLI; SHI, BINGYIN; CHEN, YAHUI; ZHANG, ZHENGXIANG; LIU, TAO

    2013-01-01

    This study aimed to determine the effects and mechanisms of gardenia oil on bone density and bone biomechanics in ovariectomized female rats. An ovariectomized rat model was established and the rats were administered various doses of gardenia oil. Rats administered diethylstilbestrol or saline served as the positive and the untreated controls, respectively. All rats received the same surgery, with the exception of the ovariectomy in the sham group. The levels of serum 17β-estradiol, follicle-stimulating hormone, luteinizing hormone, alkaline phosphatase (ALP) and calcium, and the bone material density (BMD), maximum stress and maximum strain were determined. The expression of COX-2 was also determined by immunoblotting and quantitative PCR (qPCR). Gardenia oil increased the serum levels of 17β-estradiol, the BMD, and the maximum stress and maximum strain of bones. The levels of COX-2 protein and COX-2 mRNA were significantly increased in the gardenia oil-treated rats. In conclusion, gardenia oil increases estradiol levels and BMD in an ovariectomized rat model. The effects of gardenia oil are associated with upregulation of the expression of COX-2. PMID:24137227

  20. Low-Density Lipoprotein Cholesterol Levels and Statin Treatment by HIV Status Among Multicenter AIDS Cohort Study Men

    PubMed Central

    Fu, Wei; Zikusoka, Michelle N.; Jacobson, Lisa P.; Witt, Mallory D.; Palella, Frank J.; Kingsley, Lawrence A.; Post, Wendy S.; Brown, Todd T.

    2015-01-01

    Abstract Treating cardiovascular disease (CVD) risk factors, including dyslipidemia, is important in HIV care. Low-density lipoprotein cholesterol (LDL-c) target achievement is a readily available benchmark for dyslipidemia control, although use of this target is not uniformly endorsed by professional societies. We examined whether HIV serostatus is associated with not achieving LDL-c target. Among Multicenter AIDS Cohort Study (MACS) participants completing visit 56 (10/1/2011–3/31/2012), we categorized each man as on or off statin therapy and used NCEP ATP III guidelines to determine if each man was at LDL-c target or not at target. We compared proportions of men not at target and determined predictors using multivariate logistic regression. Sixty of 543 (11.1%) HIV-infected men and 87 of 585 (14.9%) HIV-uninfected men not receiving statin therapy were not at target (p=0.07), while 31 of 230 (13.5%) HIV-infected and 29 of 204 (14.2%) HIV-uninfected men receiving statin therapy were not at target (p=0.82). Factors associated with not being at target (among men not receiving statin therapy) included current smoking (OR=2.31, 95% CI 1.31, 4.06) and a diagnosis of hypertension (OR=4.69, 95% CI 2.68, 8.21). Factors associated with not being at target (among men receiving statin therapy) included current smoking (OR=2.72, 95% CI 1.30, 5.67) and diabetes (OR=5.31, 95% CI 2.47, 11.42). HIV-infected and HIV-uninfected men receiving statin therapy demonstrated similar nonachievement of LDL-c targets. Comorbidities (e.g., diabetes) lowered targets and may explain why goals were less likely to be met. PMID:25664922

  1. Does antimicrobial use density at the ward level influence monthly central line-associated bloodstream infection rates?

    PubMed Central

    Yoshida, Junichi; Harada, Yukiko; Kikuchi, Tetsuya; Asano, Ikuyo; Ueno, Takako; Matsubara, Nobuo

    2014-01-01

    The aim of this study was to elucidate risk factors, including ward antimicrobial use density (AUD), for central line-associated bloodstream infection (CLABSI) as defined by the Centers for Disease Control and Prevention in a 430-bed community hospital using central venous lines with closed-hub systems. We calculated AUD as (total dose)/(defined daily dose × patient days) ×1,000 for a total of 20 drugs, nine wards, and 24 months. Into each line day data, we inputed AUD and device utilization ratios, number of central line days, and CLABSI. The ratio of susceptible strains in isolates were subjected to correlation analysis with AUD. Of a total of 9,997 line days over 24 months, CLABSI was present in 33 cases (3.3 ‰), 14 (42.4%) of which were on surgical wards out of nine wards. Of a total of 43 strains isolated, eight (18.6%) were methicillin-resistant Staphylococcus aureus (MRSA); none of the MRSA-positive patients had received cefotiam before the onset of infection. Receiver-operating characteristic analysis showed that central line day 7 had the highest accuracy. Logistic regression analysis showed the central line day showed an odds ratio of 5.511 with a 95% confidence interval of 1.936–15.690 as did AUD of cefotiam showing an odds ratio of 0.220 with 95% confidence interval of 0.00527–0.922 (P=0.038). Susceptible strains ratio and AUD showed a negative correlation (R2=0.1897). Thus, CLABSI could be prevented by making the number of central line days as short as possible. The preventative role of AUD remains to be investigated. PMID:25525373

  2. Serum Sema4D levels are associated with lumbar spine bone mineral density and bone turnover markers in patients with postmenopausal osteoporosis

    PubMed Central

    Zhang, Yiyuan; Feng, Eryou; Xu, Yang; Wang, Wulian; Zhang, Tao; Xiao, Lili; Chen, Rong; Lin, Yu; Chen, Dongdong; Lin, Liqiong; Chen, Kangyao; Lin, Yanbin

    2015-01-01

    To investigate the association of serum semaphorin 4D (Sema4D) levels with lumbar spine bone mineral density (BMD) and bone turnover markers in patients with postmenopausal osteoporosis (PO). Lumbar spine BMD was measured by dual-energy X-ray absorptiometry in 257 PO patients (aged from 50 to 75) and 90 healthy controls (aged from 51 to 83). Serum Sema4D, BAP, BGP and TRACP-5b levels were measured by enzyme linked immunosorbent assay. Serum cross linked N-telopeptides of type I (NTX), 25-hydroxyvitamin D (25(OH)D) and N-mid fragment of osteocalcin (N-MID-OT) levels were measured using automated electrochemiluminescence system. Sema4D level was significantly higher in PO women compared to healthy controls (1.40±0.33 vs. 0.58±0.18 μg/L, P=0.006). Sema4D level was positively correlated with serumTRACP-5b and NTX levels and negatively correlated with lumbar spine BMD and serum BAP and BGP levels. There were no correlations between Sema4D level and age, body mass index, and serum 25(OH)D and N-MID-OT levels. Lumbar spine BMD (β=-0.354, P<0.001) and serum BAP level (β=0.127, P=0.019) were independent predictors of serum Sema4D level in PO patients. Sema4D may be involved in the pathogenesis of PO and play a critical role in bone formation and resorption. Sema4D may represent a novel therapeutic target for treatment of PO and function as a predictive indicator of PO. PMID:26629156

  3. Primary Low Level of High-Density Lipoprotein Cholesterol and Risks of Coronary Heart Disease, Cardiovascular Disease, and Death: Results From the Multi-Ethnic Study of Atherosclerosis.

    PubMed

    Ahmed, Haitham M; Miller, Michael; Nasir, Khurram; McEvoy, John W; Herrington, David; Blumenthal, Roger S; Blaha, Michael J

    2016-05-15

    Prior studies observing associations between low levels of high-density lipoprotein (HDL) cholesterol and cardiovascular disease (CVD) have often been conducted among persons with metabolic or other lipid abnormalities. In this study, we investigated the association between primary low HDL cholesterol and coronary heart disease (CHD), CVD, and all-cause death after adjustment for confounders in the Multi-Ethnic Study of Atherosclerosis (MESA). Participants who were free of clinical CVD were recruited from 6 US research centers from 2000 to 2002 and followed for a median duration of 10.2 years. We defined "primary low HDL cholesterol" as HDL cholesterol level <40 mg/dL (men) or <50 mg/dL (women), triglyceride level <100 mg/dL, and low-density lipoprotein cholesterol level <100 mg/dL (n = 158). We defined an "optimal" lipid profile as HDL cholesterol ≥40 mg/dL (men) or ≥50 mg/dL (women) and triglycerides and low-density lipoprotein cholesterol <100 mg/dL (n = 780). For participants with primary low HDL cholesterol versus those with an optimal lipid profile, adjusted hazard ratios for total CHD, CVD, and death were 2.25 (95% confidence interval (CI): 1.20, 4.21; P = 0.011), 1.93 (95% CI: 1.11, 3.34; P = 0.020), and 1.11 (95% CI: 0.67, 1.84; P = 0.69), respectively. Participants with primary low HDL cholesterol had higher risks of CHD and CVD than participants with optimal lipid profiles but no difference in survival after a median 10.2 years of follow-up. PMID:27189327

  4. Higher Level of Dickkopf-1 is Associated with Low Bone Mineral Density and Higher Prevalence of Vertebral Fractures in Patients with Ankylosing Spondylitis.

    PubMed

    Rossini, Maurizio; Viapiana, Ombretta; Idolazzi, Luca; Ghellere, Francesco; Fracassi, Elena; Troplini, Sonila; Povino, Maria Rosaria; Kunnathully, Vidya; Adami, Silvano; Gatti, Davide

    2016-05-01

    Patients with ankylosing spondylitis (AS) have an increased risk of bone loss and vertebral fractures. In this study, we explored the hypothesis that the excess bone loss and vertebral fractures might be related with the activity of the Wingless signaling pathway, and in particular with the serum levels of its circulating inhibitors, Sclerostin and Dickkopf-1 (DKK1). We recruited 71 patients diagnosed with AS. Lateral radiographs of the total spine were analyzed to detect the presence of vertebral fractures, and bone mineral density (BMD) was assessed in all patients using dual X-ray absorptiometry at lumbar spine and proximal femoral site. Blood samples were obtained and levels of C-reactive protein (CRP), DKK1, and Sclerostin were measured. Blood samples from 71 healthy sex- and age-matched volunteers were collected to be used as controls. Vertebral fractures were detected more commonly among men than in women (29 vs 8 %, respectively). DKK1, but not Sclerostin serum levels, were inversely correlated to lumbar spine Z-score BMD. Patients with one or more prevalent vertebral fractures had significantly higher DKK1 levels, without significant difference in Sclerostin serum levels. A significant positive correlation was found between DKK1 serum levels and CRP (r = 0.240, p = 0.043). The association we found between serum DKK1 levels and BMD values and vertebral fracture prevalence suggests that DKK1 might contribute to the severity of osteoporosis in AS. PMID:26645432

  5. Accurate dipole polarizabilities for water clusters n=2-12 at the coupled-cluster level of theory and benchmarking of various density functionals.

    SciTech Connect

    Hammond, J.; Govind, N.; Kowalski, K.; Autschbach, J.; Xantheas, S.; PNNL; Univ. of Buffalo

    2009-12-07

    The static dipole polarizabilities of water clusters (2 {le} N {le} 12) are determined at the coupled-cluster level of theory (CCSD). For the dipole polarizability of the water monomer it was determined that the role of the basis set is more important than that of electron correlation and that the basis set augmentation converges with two sets of diffuse functions. The CCSD results are used to benchmark a variety of density functionals while the performance of several families of basis sets (Dunning, Pople, and Sadlej) in producing accurate values for the polarizabilities was also examined. The Sadlej family of basis sets was found to produce accurate results when compared to the ones obtained with the much larger Dunning basis sets. It was furthermore determined that the PBE0 density functional with the aug-cc-pVDZ basis set produces overall remarkably accurate polarizabilities at a moderate computational cost.

  6. The Effect of Residing Altitude on Levels of High-Density Lipoprotein Cholesterol: A Pilot Study From the Omani Arab Population.

    PubMed

    Al Riyami, Nafila B; Banerjee, Yajnavalka; Al-Waili, Khalid; Rizvi, Syed G; Al-Yahyaee, Said; Hassan, Mohammed O; Albarwani, Sulayma; Al-Rasadi, Khalid; Bayoumi, Riad A

    2015-07-01

    Lower mortality rates from coronary heart disease and higher levels of serum high-density lipoprotein cholesterol (HDL-C) have been observed in populations residing at high altitude. However, this effect has not been investigated in Arab populations, which exhibit considerable genetic homogeneity. We assessed the relationship between residing altitude and HDL-C in 2 genetically similar Omani Arab populations residing at different altitudes. The association between the levels of HDL-C and other metabolic parameters was also investigated. The levels of HDL-C were significantly higher in the high-altitude group compared with the low-altitude group. Stepwise regression analysis showed that altitude was the most significant factor affecting HDL-C, followed by gender, serum triglycerides, and finally the 2-hour postprandial plasma glucose. This finding is consistent with previously published studies from other populations and should be taken into consideration when comparing cardiovascular risk factors in populations residing at different altitudes. PMID:25078070

  7. Low 25-hydroxyvitamin D levels and low bone density assessed by quantitative ultrasonometry in a cohort of postmenopausal Italian nuns.

    PubMed

    Nuzzo, Vincenzo; Zuccoli, Antonio; de Terlizzi, Francesca; Colao, Annamaria; Tauchmanova, Libuse

    2013-01-01

    This study was aimed at evaluating the effect of clothing style on bone mass and fractures in 70 postmenopausal nuns residing in a monastery in Naples. Sixty healthy women matched for age, body mass index, and menopausal status were enrolled as controls. Each participant underwent measurement by quantitative ultrasonometry (QUS) using a DBM Sonic Bone Profiler (IGEA S.p.A., Carpi, Modena, Italy) at proximal phalanges, responded to questionnaires regarding lifestyle, calcium intake, medical history, including clinical fragility fractures, and was submitted to routine biochemical assessment. A significant reduction in ultrasonometric parameters of bone mass was found in nuns compared with controls (p from 0.007 to <0.0001). 25-hydroxyvitamin D (25-OH vit D) levels were reduced by more than 50% in nuns (9.8 ± 4.2 vs 23.5 ± 5.7 nmol/L; p < 0.0001), whereas their estimated daily calcium intake was higher (1.004 ± 0.23 vs 0.721 ± 0.25 g of controls; p = 0.0007). Age at menopause was significantly lower in nuns' group (p = 0.016). Incidence of fractures was higher in nuns (39% vs 10%; p = 0.0029), and the best predictors of fractures were age at menopause (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.01-1.30), amplitude-dependent speed of sound T-score (OR: 1.15; 95% CI: 1.03-1.63), and bone transmission time T-score (OR: 1.30; 95% CI: 1.15-1.81). This study documented low 25-OH vit D levels, increased frequency of clinical fractures, and low bone mass detected by QUS in Southern Italian nuns. PMID:22832035

  8. Serum Lipid, Lipoprotein and Oxidatively Modified Low Density Lipoprotein Levels in Active or Inactive Patients with Behçet's Disease

    PubMed Central

    Cimen, Fuat; Yildirmak, Sembol Turken; Ergen, Andac; Cakmak, Mustafa; Dogan, Serkan; Yenice, Necati; Sezgin, Funda

    2012-01-01

    Aim: To determine serum lipid, lipoproteins and oxidized low density lipoprotein (oxLDL) levels in Behçet's disease (BD) and to evaluate the relationship of these parameters with the clinical activity of the disease. Materials and Methods: Sixty-two patients (25 active, 37 inactive) and —26 healthy controls were included in the study. We measured serum oxLDL levels using the enzyme-linked immunosorbent assay method, and serum total cholesterol (TC), triglyceride (TG) and high density lipoprotein-cholesterol (HDL-C) levels by spectrophotometric method. Results: Serum TG (108±70 mg/dL and 79±40 mg/dL, respectively; P<0.05), LDL-C (124±35 mg/dL and 108±26 mg/dL, respectively; P<0.05) and oxLDL (65±19 U/L and 53±10 U/L, respectively; P<0.01) levels were significantly higher in patients than in controls, but HDL-C levels were significantly lower in patients than in controls (39±11 mg/dL and 50±13 mg/dL, respectively; P<0.05). The levels of oxLDL in patients were found to correlate with those of TC and LDL-C. Neither the lipid parameters nor the oxLDL levels in the patients with active disease (n=25) were different than those in the patients who were in inactive stage (n=37). Serum levels of oxLDL in the patients with active and inactive disease were significantly higher than those in controls (66±19 U/L, 65±19 U/L, and 53±10 U/L, respectively; P<0.05). Conclusions: We conclude that the increase of TG, LDL-C and oxLDL levels and the decrease of HDL-levels may indicate that there is a tendency to atherothrombotic process in patients with BD. Inflammation and immunologic reactions in BD may be caused by a response to elevated oxLDL. TG, LDL-C and oxLDL are not useful markers for the severity of the disease activity. PMID:22615503

  9. Supercell-size convergence of formation energies and gap levels of vacancy complexes in crystalline silicon in density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Dabrowski, J.; Kissinger, G.

    2015-10-01

    Results for supercell-size convergence of formation energies and charge transition levels of vacancy complexes Vn(1 ≤n ≤11 ) in crystalline Si are reported for the ab initio density functional theory (DFT) with generalized gradient approximation (GGA) pseudopotentials. When extrapolated to the dilute limit, the formation energy of an uncharged vacancy becomes 3.74 ±0.1 eV , and the binding energy of an uncharged divacancy becomes 1.9 ±0.2 eV . Stable Vn clusters are built on the basis of sixfold rings (n ≤6 ) and of octahedral voids (n ≥7 ) . If the well-known underestimate of the band gap by the DFT and the accuracy of extrapolations are taken into account, the extrapolated levels are in good agreement with experiment. We discuss the implications for simulation of vacancy clustering during thermal quenching, for interpretation of deep-level spectroscopy and electron paramagnetic resonance in irradiated Si, and for cell and Brillouin-zone sampling choice when DFT-related methods beyond local-density approximation or GGA are used.

  10. Nuclear level densities in {sup 47}V, {sup 48}V, {sup 49}V, {sup 53}Mn, and {sup 54}Mn from neutron evaporation spectra

    SciTech Connect

    Zhuravlev, B. V. Lychagin, A. A.; Titarenko, N. N.; Demenkov, V. G.; Trykova, V. I.

    2011-03-15

    The spectra of neutrons from the (p, n) reactions on {sup 47}Ti, {sup 48}Ti, {sup 49}Ti, {sup 53}Cr, and {sup 54}Cr nuclei were measured in the proton-energy range 7-11 MeV. The measurements were performed with the aid of a fast-neutron spectrometer by the time-of-flight method over the base of the EGP-15 tandem accelerator of the Institute for Physics and Power Engineering (IPPE, Obninsk). Owing to a high resolution and a high stability of the time-of-flight spectrometer used, low-lying discrete levels could be identified reliably along with a continuum section of neutron spectra. An analysis of measured data was performed within the statistical equilibrium and preequilibrium models of nuclear reactions. The relevant calculations were performed by using the exact formalism of Hauser-Feshbach statistical theory supplemented with the generalized model of a superfluid nucleus, the back-shifted Fermi gas model, and the Gilbert-Cameron composite formula for the nuclear level density. The nuclear level densities for {sup 47}V, {sup 48}V, {sup 49}V, {sup 53}Mn, and {sup 54}Mn were determined along with their energy dependences and model parameters. The results are discussed together with available experimental data and recommendations of model systematics.